European Journal of Pharmacology (v.765, #C)
Editorial Board (ii).
Structural insights into the benzophenanthridines binding to human glycine transporter GlyT1 by Frantisek Jursky; Martina Baliova; Anna Juhasova (1-6).
We previously identified cysteine 475 as a key residue for the inhibitory action of sanguinarine on the human glycine transporter GlyT1c. To define potential benzophenanthridine binding pocket more closely, we created a structural homology model of GlyT1 and also mutated several amino acids in the vicinity of cysteine 475. Even though this area contains the molecular determinants of the glycine and sodium permeation pathways, and several mutations resulted in an inactive transporter, we found that the mutation of a polar aromatic tyrosine 370 to purely aromatic phenylalanine, but not to an aliphatic leucine, significantly increased the sensitivity of GlyT1 to both sanguinarine and chelerythrine. The reduction of sanguinarine to dihydrosanguinarine completely eliminated the alkaloid’s inhibitory potency. Both these results suggest that aromaticity is important in the interaction of benzophenanthridines with GlyT1. Even though tyrosine 370 is part of the conformationaly highly flexible glycine binding site, and is accesible during the transport process from both intra and extracellular sites, the cytoplasmic location of the second alkaloid sensitive residue, cysteine 475, suggests that the benzophenanthridines might attack the area of the GlyT1 intracellular gates.
Keywords: Benzophenanthridine; Sanguinarine; Chelerythrine; Neurotransmitter; Glycine transporter; GlyT1;
Cardiovascular protection by ezetimibe and influence on oxidative stress in mice exposed to intermittent hypoxia by Ryuji Kato; Satoshi Nishioka; Atsuo Nomura; Yoshio Ijiri; Masatoshi Miyamura; Akira Ukimura; Yoshikatsu Okada; Yasushi Kitaura; Tetsuya Hayashi (7-14).
Ezetimibe is as an inhibitor of NPC1L1 protein, which has a key role in cholesterol absorption. The aim of this study was to evaluate the influence of ezetimibe on the plasma lipid profile, atherosclerotic lesions, and cardiomyocyte ultrastructure in an animal model of atherosclerosis with intermittent hypoxia. Apolipoprotein E-knockout mice received a high-fat diet for 30 days. Then animals were exposed to intermittent hypoxia for 10 days or were maintained under normoxic conditions. In the ezetimibe group, ezetimibe (5 mg/kg/day) was added to the diet. Under normoxic conditions, the total cholesterol level was significantly lower in the ezetimibe group (63.6±6.6 mg/dl) than in the control group (116.3±16.9 mg/dl, P<0.001). Intermittent hypoxia accelerated atherosclerosis associated with increased superoxide production, which also caused degeneration of cardiomyocytes, mitochondrial abnormalities, and interstitial fibrosis. Compared with the control group, the ezetimibe group showed significantly less advanced atherosclerotic lesions and lower superoxide production in the thoracic aorta, as well as reduced oxidative stress, preservation of cardiomyocyte ultrastructure, and reduced interstitial fibrosis in the left ventricular myocardium. In conclusion, ezetimibe not only reduces total cholesterol, but also prevents the development of atherosclerosis and cardiovascular events due to intermittent hypoxia at least partly through suppression of oxidative stress.
Keywords: Ezetimibe; Hypoxia; Atherosclerosis; Oxidative stress; Ultrastructure;
Effect of the potent and selective DP1 receptor antagonist, asapiprant (S-555739), in animal models of allergic rhinitis and allergic asthma by Go Takahashi; Fujio Asanuma; Noriko Suzuki; Maki Hattori; Shingo Sakamoto; Akira Kugimiya; Yasuhiko Tomita; Goro Kuwajima; William M. Abraham; Masashi Deguchi; Akinori Arimura; Michitaka Shichijo (15-23).
Prostaglandin (PG) D2 elicits responses through either the DP1 and/or DP2 receptor. Experimental evidence suggests that stimulation of the DP1 receptor contributes to allergic responses, such that antagonists are considered to be directed therapies for allergic diseases. In this study, we demonstrate the activity of a novel synthetic DP1 receptor antagonist termed asapiprant (S-555739) for the DP1 receptor and other receptors in vitro, and assess the efficacy of asapiprant in several animal models of allergic diseases. We determined the affinity and selectivity of asapiprant for the DP1 receptor in binding assays. In the animal models of allergic rhinitis, changes in nasal resistance, nasal secretion, and cell infiltration in nasal mucosa were assessed after antigen challenge with and without asapiprant. Similarly, in the animal models of asthma, the effect of antigen challenge with and without asapiprant on antigen-induced bronchoconstriction, airway hyper-responsiveness, mucin production, and cell infiltration in lung were assessed. In binding studies, asapiprant exhibited high affinity and selectivity for the DP1 receptor. Significant suppression of antigen-induced nasal resistance, nasal secretion, and cell infiltration in nasal mucosa was observed with asapiprant treatment. In addition, treatment with asapiprant suppressed antigen-induced asthmatic responses, airway hyper-responsiveness, and cell infiltration and mucin production in lung. These results show that asapiprant is a potent and selective DP1 receptor antagonist, and exerts suppressive effects in the animal models of allergic diseases. Thus, asapiprant has potential as a novel therapy for allergic airway diseases.
Keywords: Prostaglandin D2; Synthetic DP1 receptor antagonist; Allergic rhinitis; Asapiprant; Nasal congestion;
Suppressive effect of membrane-permeable peptides derived from autophosphorylation sites of the IGF-1 receptor on breast cancer cells by Yoshihiro Kuroda; Nahoko Kato-Kogoe; Emi Tasaki; Mayumi Yuasa-Sunagawa; Koji Yamanegi; Keiji Nakasyo; Ikuhiko Nakase; Shiroh Futaki; Yumi Tohyama; Munetaka Hirose (24-33).
Insulin-like growth factor-1 (IGF-1) receptors play a crucial role in the biology of human cancer, making them an attractive target for anti-cancer agents. We previously designed oligopeptides containing the amino-acid sequences surrounding the autophosphorylation sites of the insulin receptor and found that two of them, namely, Ac-DIYET-NH2 and Ac-DYYRK-NH2, suppressed phosphorylation of purified insulin receptors in a non-ATP-competitive manner, whereas Ac-NIYQT-NH2 and Ac-NYYRK-NH2 suppressed in an ATP-competitive manner. Because the IGF-1 receptor is closely related to the insulin receptor, the aim of this study was to observe the effects of these peptides, which correspond to the amino-acid sequences of the autophosphorylation sites of the IGF-1 receptor, on the activity of the human breast cancer cell lines MCF-7, T47D, MDA-MB-231, and MDA-MB-453. To facilitate peptide delivery into breast cancer cells, the cell-penetrating peptide, human immunodeficiency virus type 1-transactivator of transcription (Tat), was linked to these peptides. When breast cancer cells were treated with each of these synthetic Tat-conjugated peptides, the conjugated peptides penetrated into the cells and suppressed cell proliferation. An inhibitory effect of Tat-conjugated peptides against IGF-1-stimulated phosphorylation of IGF-1 receptors was observed. In addition, we found that combinations of these peptides suppressed phosphorylation of IGF-1 receptors to a greater extent than the peptides did individually. In conclusion, IGF-1 receptor autophosphorylation site-derived membrane-permeable peptides have the potential to suppress IGF-1 receptor function in breast cancer cells and to be developed into novel and useful agents for cancer therapy.
Keywords: Breast cancer cell; Cell-penetrating peptide; IGF-1 receptor; Tyrosine kinase inhibitor;
Inhibition of gastric H+,K+-ATPase by 4-(2-butyl-6,7-dichloro-2-cyclopentylindan-1-on-5-yl)oxybutyric acid (DCPIB), an inhibitor of volume-regulated anion channel by Takuto Fujii; Yuji Takahashi; Hiroshi Takeshima; Chisato Saitoh; Takahiro Shimizu; Noriaki Takeguchi; Hideki Sakai (34-41).
4-(2-Butyl-6,7-dichloro-2-cyclopentylindan-1-on-5-yl)oxybutyric acid (DCPIB) has been used as an inhibitor of volume-regulated anion channel (VRAC), which is expressed in almost all cells (IC50 is around 4 µM). Here, we found that DCPIB significantly inhibited the activities of gastric proton pump (H+,K+-ATPase) in isolated gastric tubulovesicles and the membrane sample of the H+,K+-ATPase-expressing cells, and their IC50 values were around 9 µM. In the tubulovesicles, no significant expression of leucine rich repeat containing 8 family member A (LRRC8A), an essential component of VRAC, was observed. The inhibitory effect of DCPIB was also found in the membrane sample obtained from the cells in which LRRC8A had been knocked down. On the other hand, DCPIB had no significant effect on the activity of Na+,K+-ATPase or Ca2+-ATPase. In the H+,K+-ATPase-expressing cells, DCPIB inhibited the 86Rb+ transport activity of H+,K+-ATPase but not that of Na+,K+-ATPase. DCPIB had no effect on the activity of Cl− channels other than VRAC in the cells. These results suggest that DCPIB directly inhibits H+,K+-ATPase activity. DCPIB may be a beneficial tool for studying the H+,K+-ATPase function in vitro.
Keywords: H+,K+-ATPase; Proton pump; DCPIB; Volume-regulated anion channel; LRRC8A;
Reduction in renal blood flow following administration of norepinephrine and phenylephrine in septic rats treated with Kir6.1 ATP-sensitive and KCa1.1 calcium-activated K+ channel blockers by Bruna da Rosa Maggi Sant’Helena; Karla L. Guarido; Priscila de Souza; Sandra Crestani; J. Eduardo da Silva-Santos (42-50).
We evaluated the effects of K+ channel blockers in the vascular reactivity of in vitro perfused kidneys, as well as on the influence of vasoactive agents in the renal blood flow of rats subjected to the cecal ligation and puncture (CLP) model of sepsis. Both norepinephrine and phenylephrine had the ability to increase the vascular perfusion pressure reduced in kidneys of rats subjected to CLP at 18 h and 36 h before the experiments. The non-selective K+ channel blocker tetraethylammonium, but not the Kir6.1 blocker glibenclamide, normalized the effects of phenylephrine in kidneys from the CLP 18 h group. Systemic administration of tetraethylammonium, glibenclamide, or the KCa1.1 blocker iberiotoxin, did not change the renal blood flow in control or septic rats. Norepinephrine or phenylephrine also had no influence on the renal blood flow of septic animals, but its injection in rats from the CLP 18 h group previously treated with either glibenclamide or iberiotoxin resulted in an exacerbated reduction in the renal blood flow. These results suggest an abnormal functionality of K+ channels in the renal vascular bed in sepsis, and that the blockage of different subtypes of K+ channels may be deleterious for blood perfusion in kidneys, mainly when associated with vasoactive drugs.
Keywords: Septic shock; Kidneys; Glibenclamide; Tetraethylammonium; Iberiotoxin.;
Facilitatory effect of dopamine on neuromuscular transmission mediated via dopamine D1-like receptors and prospective interaction with nicotine by H.E. AlQot; N.A. Elnozahi; M.M. Mohy El-Din; A.E. Bistawroos; M.S. Abou Zeit-Har (51-57).
The objective of this study is to probe the effects of dopamine and potential interactions with nicotine at the motor end plate. To accomplish this, we measured the amplitude of nerve-evoked muscle twitches of the isolated rat phrenic hemi-diaphragm preparation. Dopamine potentiated indirect muscle twitches in normal and gallamine-presensitized preparations amounting to a maximum of 31.14±0.71% and 69.23±1.96%, respectively. The dopamine-induced facilitation was well maintained in presence of 10 µM propranolol but greatly reduced in presence of 6 µM SCH 23390 or 3 µM dantrolene. In addition, SKF 81297 attained a plateau at 16 µM as opposed to 64 µM dopamine, with a percentage potentiation of 69.47±1.76. The facilitatory effect of dopamine was potentiated in nicotine treated rats. This study revealed for the first time that the facilitatory effect exerted by dopamine on neuromuscular transmission is mediated via the dopamine D1-like receptors. In addition, it highlighted the possible dependency of dopamine effects on intracellular calcium and signified potential interaction among dopamine and nicotine. Clinically, the findings generated by this study reveal potential targets for approaching motor deficit syndromes.
Keywords: Dopamine; Neuromuscular junction; dopamine D1-like receptors; Nicotine;
Efficacy of carvedilol in reversing hypertension induced by chronic intermittent hypoxia in rats by Lucília N. Diogo; Sofia A. Pereira; Ana R. Nunes; Ricardo A. Afonso; Ana I. Santos; Emília C. Monteiro (58-67).
Animal models of chronic intermittent hypoxia (CIH) mimic the hypertension observed in patients with obstructive sleep apnoea. Antihypertensive drugs were applied to these animal models to address the physiological mechanism but not to revert established hypertension. We aimed to investigate the efficacy of carvedilol (CVDL), an unselective beta-blocker that exhibits intrinsic anti-α1-adrenergic and antioxidant activities in a rat model of CIH-induced hypertension. The variability of CVDL enantiomers in plasma concentrations was also evaluated.Wistar rats with indwelling blood pressure telemeters were exposed during their sleep period to 5.6 CIH cycles/h, 10.5 h/day, for 60 days. CVDL was administered by gavage beginning on Day 36 of the CIH period and was continued for 25 days. R-(+)-CVDL and S-(−)-CVDL plasma concentrations were monitored by HPLC.CIH significantly increased diastolic and systolic blood pressure by 25.7 and 21.6 mm Hg respectively, while no effect was observed on the heart rate (HR). CVDL administration at 10, 30 and 50 mg/kg/day promoted a significant reduction in HR but did not affect arterial pressure. The S/(R+S) ratio of CVDL enantiomers was lower in rats exposed to CIH.The blockade of the sympathetic nervous system together with the putative pleiotropic effects of CVDL did not alter the CIH-induced hypertension. Although CIH induced pharmacokinetic changes in the R/(R+S) ratio, these effects do not appear to be responsible for the inability of CVDL to reverse this particular type of hypertension.
Keywords: Antihypertensive drugs; Beta-blockers; Carvedilol; Chronic intermittent hypoxia; Telemetry;
Synergistic antinociceptive interaction between palmitoylethanolamide and tramadol in the mouse formalin test by Myrna Déciga-Campos; Pamela Moncerrat Ramírez-Marín; Francisco Javier López-Muñoz (68-74).
Pharmacological synergism has been used to obtain a higher efficacy using drug concentrations at which side effects are minimal. In this study, the pharmacological antinociceptive interaction between N-palmitoylethanolamide (PEA) and tramadol was investigated. The individual concentration–response curves for PEA (0.1–56.2 μg/paw) and tramadol (1–56.2 μg/paw) were evaluated in mice in which nociception was induced by an intraplantar injection of 2% formalin. Isobolographic analysis was used to evaluate the pharmacological interaction between PEA (EC50=23.7±1.6 μg/paw) and tramadol (EC50=26.02±2.96 μg/paw) using the EC50 and a fixed 1:1 ratio combination. The isobologram demonstrated that the combinations investigated in this study produced a synergistic interaction; the experimental values (Z exp=9.5±0.2 μg/paw) were significantly smaller than those calculated theoretically (Z add=24.8±0.2 μg/paw). The antinociceptive mechanisms of the PEA and tramadol combination involved the opioid receptor, transient receptor potential cation channel subfamily V member 1 (TRPV1), and peroxisome proliferator-activated receptor alpha (PPAR-α). The sedative effect of the combination of PEA and tramadol was less than that generated by individual treatments. These findings suggest that the PEA and tramadol combination produced enhanced antinociceptive efficacy at concentrations at which side effects are minimal.Display Omitted
Keywords: Antinociception; N-palmitoylethanolamide; Tramadol; Isobolographic; Synergism;
A novel stereo bioactive metabolite isolated from an endophytic fungus induces caspase dependent apoptosis and STAT-3 inhibition in human leukemia cells by Anup Singh Pathania; Santosh Kumar Guru; Nissar Ul Ashraf; Syed Riyaz-Ul-Hassan; Asif Ali; Sheikh Abdullah Tasduq; Fayaz Malik; Shashi Bhushan (75-85).
The present study describes the anti-leukemic potential of a novel stereo bioactive secondary metabolite, (R)-5-hydroxy-2-methylchroman-4-one (HMC) isolated from a novel endophytic fungus source (Cryptosporiopsis sp. H2-1, NFCCI-2856), associated with Clidemia hirta. HMC inhibited cell proliferation of different cancer cell lines with IC50 values in the range of 8–55 µg/ml. The cytotoxicity window of HMC was 6–12 times lower in normal cells as compared to susceptible leukemic HL-60, MOLT-4 and K-562 cells. It persuades apoptosis through both intrinsic and extrinsic pathways in above leukemic cell lines, which was evident through Hoechst staining, Annexin-V binding, cell cycle analysis, loss of mitochondrial membrane potential (Δψm ), release of cytochrome c, Bax, Bid, over-expression of apical death receptors, activation of caspase-3,-8,-9 and PARP (poly ADP ribose polymerase) cleavage. HMC induced caspase dependent apoptosis and robustly attenuate transcription factor, p-STAT-3 in myeloid and lymphoid leukemia cells. The mechanism of HMC arbitrated inhibition of p-STAT-3 was due to the activation of ubiquitin dependent degradation of p-STAT-3. Therefore, our study not only describes the anti-leukemic potential of HMC but also provides insights into how endophytes can be useful in discovery and development of novel anticancer therapeutics.Display Omitted
Keywords: (R)-5-hydroxy-2-methylchroman-4-one (HMC); Endophyte; Apoptosis; STAT-3; Proteosome inhibitor;
Current and future treatment strategies for iron overload cardiomyopathy by Suwakon Wongjaikam; Sirinart Kumfu; Siriporn C. Chattipakorn; Suthat Fucharoen; Nipon Chattipakorn (86-93).
Iron overload cardiomyopathy is the major cause of death in transfusion-dependent thalassemia (TDT) patients. Growing evidence demonstrates that combined iron chelators, or the combination of an iron chelator with antioxidant(s) are effective in diminishing myocardial iron deposition and attenuating cardiac dysfunction. This review comprehensively summarizes basic and clinical reports on the therapeutic efficacy of combined iron chelators, or the combination of an iron chelator with antioxidant(s) on the heart. Promising benefits of these treatments in preventing cardiac dysfunction due to iron overload could provide extensive insight into future therapeutic strategies for better treatment and prevention of cardiomyopathy in TDT patients.
Keywords: Iron overload cardiomyopathy; Iron chelator; Deferoxamine; Deferiprone; Deferasirox; Antioxidant;
Atractylenolide I protects mice from lipopolysaccharide-induced acute lung injury by Jun-liang Zhang; Wei-min Huang; Qi-yi Zeng (94-99).
Atractylenolide I (AO-I), one of the major bioactive components isolated from Rhizoma Atractylodes macrocephala, has been reported to have anti-inflammatory effects. In the present study, we investigated the protective effects of AO-I on acute lung injury (ALI) using LPS-induced ALI mouse model. Lung injury was assessed by histological study. Inflammatory cytokines TNF-α, IL-6 and IL-1β production were detected by ELISA. TLR4 expression and NF-κB activation were measured by western blot analysis. The results showed that treatment of AO-I significantly attenuated LPS-induced lung wet-to-dry weight ratio and MPO activity. Meanwhile, treatment of AO-I significantly inhibited the production of TNF-α, IL-6, IL-1β, IL-13, and MIF production in bronchoalveolar lavage fluid (BALF), as well as neutrophils and macrophages in BALF. AO-1 could up-regulate the production of IL-10 in BALF. Besides, LPS-induced TLR4 expression and NF-κB activation were suppressed by treatment of AO-I. In conclusion, the current study suggested that AO-I protected mice acute lung injury induced by LPS via inhibition of TLR4 expression and NF-κB activation.
Keywords: Atractylenolide I; LPS; Acute lung injury; TLR4; NF-κB;
Why are second-generation H1-antihistamines minimally sedating? by Yawen Hu; Deidra E. Sieck; Walter H. Hsu (100-106).
H1-antihistamines are widely used in treating allergic disorders, e.g., conjunctivitis, urticaria, dermatitis and asthma. The first-generation H1-antihistamines have a much greater sedative effect than the second-generation H1-antihistamines. Researchers could not offer a satisfactory explanations until late 1990s when studies showed that second-generation H1-antihistamines were substrates of P-glycoprotein. P-glycoprotein, expressed in the blood–brain barrier, acts as an efflux pump to decrease the concentration of H1-antihistamines in the brain, which minimizes drug effects on the central nervous system and results in less sedation. P-glycoprotein is found in the apical side of the epithelium. It consists of transmembrane domains that bind substrates/drugs and nucleotide-binding domains that bind and hydrolyze ATP to generate energy for the drug efflux. This review mainly discusses interactions between P-glycoprotein and commonly used second-generation H1-antihistamines. In addition, it describes other possible determining factors of minimal sedating properties of second-generation H1-antihistamines.
Keywords: H1-antihistamine; P-glycoprotein; MDR1; Sedative effect; Minimally sedating;
Mechanisms of vasorelaxation induced by the cannabidiol analogue compound O-1602 in the rat small mesenteric artery by Y.M. Al Suleimani; A.S. Al Mahruqi; C.R. Hiley (107-114).
Atypical cannabinoid O-1602 (5-Methyl-4-[(1R,6R)-3-methyl-6-(1-cyclohexen-1-yl]-1,3-benzenediol) induces vasorelaxation and activates the orphan G protein-coupled receptor GPR55 in human endothelial cells. This study investigates the underlying mechanisms of vasorelaxation induced by this compound. The vasodilator activity was assessed in the rat third order branch of the superior mesenteric artery using a wire myograph. The vasorelaxation was partially endothelium-dependent (pEC50%=5.8±0.3). The endothelial component was antagonized by the putative endothelial receptor antagonists rimonabant (3 µM; pEC50%=5.1±0.2) and O-1918 (10 µM; pEC50%=5.3±0.2) but not by the CB1 and CB2 receptors antagonists AM 251 (10 µM) and AM 630 (10 µM), respectively. The vasorelaxation was not pertussis toxin-sensitive and not mediated through TRPVI receptors or by the release of NO, but was reduced by inhibition of Ca2+ sensitive K+ channels (KCa). In endothelium-denuded vessels, O-1602 abolished CaCl2-induced contraction and the inhibition was apparently reversed by O-1918. O-1602 mediates its vasorelaxant effects partly by an endothelium-dependent pathway involving rimonabant- and O-1918-sensitive targets that are distinct from the classical CB1 and CB2 cannabinoid receptors and might involve activation of KCa. The endothelium-independent relaxation might involve interfering with Ca2+ entry.
Keywords: O-1602; Vasorelaxation; Endothelium; Ca2+ sensitive K+ channels; Cannabinoid receptor;
Herbacetin inhibits inducible nitric oxide synthase via JNK and nuclear factor-κB in LPS-stimulated RAW264.7 cells by Liang Li; Mahesh Sapkota; Se-woong Kim; Yunjo Soh (115-123).
Herbacetin (3,4′,5,7,8-pentahydroxyflavone), an active flavonol compound within flavonoid, has been shown to induce apoptosis in HepG2 cells and suppress hepatocyte growth factor-induced motility of human breast cancer MDA-MB-231 cells. However, the anti-inflammatory mechanisms of Herbacetin have not been researched. In this study, we examined the inflammatory responses stimulated by lipopolysaccharide (LPS) in RAW264.7 macrophage cells after pretreatment with different concentrations of Herbacetin. We found that Herbacetin decreased nitric oxide (NO) production in LPS-induced RAW264.7 and mouse bone marrow-derived macrophages. In addition, Herbacetin inhibited the LPS-induced expression of inducible nitric oxide synthase mRNA and protein in RAW264.7 cells. Treatment with Herbacetin decreased the release of proinflammatory cytokines, including TNF-α and IL-1β. Moreover, Herbacetin inhibited the activity of JNK kinase and nuclear factor-κB, signaling molecules involved in NO production. Cell signaling analysis using Bay 11-7082 (an inhibitory κB kinase 2 inhibitor) and mitogen-activated protein kinase (MAPK) inhibitors (SB203580 for p38, SP600125 for JNK, and PD 98059 for ERK) suggested that LPS induced iNOS expression via activation of the JNK and NF-κB pathway, but not the p38 and ERK pathway. These findings suggest that Herbacetin exerts an anti-inflammatory effect through suppression of LPS-induced JNK and NF-κB signaling pathways and diminished production of proinflammatory cytokines and mediators.Display Omitted
Keywords: Herbacetin; Inducible nitric oxide synthase; NF-κB; MAPK; Anti-inflammation;
Genetic variations of hOCT1 gene and CYP3A4/A5 genes and their association with imatinib response in Chronic Myeloid Leukemia by Shantashri Vaidya; Kanjaksha Ghosh; Chandrakala Shanmukhaiah; Babu Rao Vundinti (124-130).
There is an increasing body of evidence demonstrating that mechanisms independent of BCR/ABL gene also contribute to imatinib resistance in Chronic Myeloid Leukemia (CML). It has been extensively reported that polymorphisms of the genes associated with imatinib metabolization and imatinib influx/efflux play an important role in the disease resistance. We investigated the impact of 12 genetic variants of the two genes, CYP3A4/A5 and the human cation transporter 1 gene (hOCT1) on the clinical outcome, in a cohort of 106 newly diagnosed CML patients. In the patient cohort investigated, only 6 variant alleles could be detected. The others were not present and could not be investigated. Two polymorphisms, CYP3A5*3 (rs776746)and hOCT1 M408V (rs628031), were significantly associated with the Complete Cytogenetic Response (CCyR) at 6 months and Major Molecular Response (MMR) at 12 months. The presence of favourable alleles at M408V and M420del in combination was associated with a MMR at 12 months. Functional polymorphisms of the genes associated with imatinib influx and metabolization may play a role in predicting primary response to imatinib and treatment outcome.
Keywords: Chronic myeloid leukemia; hOCT1; CYP3A4/A5; Genotyping; Imatinib resistance;
Oleanolic acid attenuates obstructive cholestasis in bile duct-ligated mice, possibly via activation of NRF2-MRPs and FXR antagonism by Pan Chen; Jingjie Li; Xiaomei Fan; Hang Zeng; Rongrong Deng; Dongshun Li; Min Huang; Huichang Bi (131-139).
Obstructive cholestasis is characterized by impairment of hepatic canalicular bile efflux and there are no clinically effective drugs to cure except surgeries. Previously we revealed that oleanolic acid (OA) protected against lithocholic acid (LCA)-induced intrahepatic cholestasis in mice. Cholestasis caused by LCA is characterized by segmental bile duct obstruction, whether OA possesses the beneficial effect on completed obstructive cholestasis induced by bile duct ligation (BDL) remains unknown. In this study, we demonstrated that BDL-induced mice liver pathological change, and increase in serum levels of ALT, AST and ALP were all significantly reduced by OA (20 mg/kg, i.p.). Meanwhile, OA also lowered total bilirubin and total bile acids levels in serum, as well as total bile acids level in liver, in contrast, urinary total bile acids output was remarkably up-regulated by OA. Gene expression analysis showed that OA caused significant increased mRNA expression of MRP3 and MRP4 located at hepatic basolateral membrane, and restoration of MRP2 and BSEP located at hepatic cannalicular membrane. Furthermore, significant NRF2 protein accumulation in nucleus was also observed in OA treated mice. In mice primary cultured hepatocytes, the effects of OA on MRP2, MRP3 and MRP4 expression were directly proved to be mediated via NRF2 activation, and BSEP downregulation induced by OA was in part due to FXR antagonism. Luciferase assay performed in Hep G2 cells also illustrated that OA was a partial FXR antagonist. Taken together, we conclude that OA attenuates obstructive cholestasis in BDL mice, possibly via activation of NRF2-MRPs and FXR antagonism.
Keywords: Oleanolic acid; Cholestasis; Bile duct ligation; NRF2; MRP; FXR;
β2-adrenoceptor agonist-evoked reactive oxygen species generation in mouse atria: implication in delayed inotropic effect by Ulia G. Odnoshivkina; Vaycheslav I. Sytchev; Leniz F. Nurullin; Arthur R. Giniatullin; Andrei L. Zefirov; Alexey M. Petrov (140-153).
Fenoterol, a β2-adrenoceptor agonist, has anti-apoptotic action in cardiomyocytes and induces a specific pattern of downstream signaling. We have previously reported that exposure to fenoterol (5 μM) results in a delayed positive inotropic effect which is related to changes in both Ca2+ transient and NO. Here, the changes in reactive oxygen species (ROS) production in response to the fenoterol administration and the involvement of ROS in effect of this agonist on contractility were investigated in mouse isolated atria. Stimulation of β2-adrenoceptor increases a level of extracellular ROS, while intracellular ROS level rises only after removal of fenoterol from the bath. NADPH-oxidase inhibitor (apocynin) prevents the increase in ROS production and the Nox2 isoform is immunofluorescently colocalized with β2-adrenoceptor at the atrial myocytes. Treatments with antioxidants (N-acetyl-l-cysteine, NADPH inhibitors, exogenous catalases) significantly inhibit the fenoterol induced increase in the contraction amplitude, probably by attenuating Ca2+ transient and up-regulating NO production. ROS generated in a β2-adrenoceptor-dependent manner can potentiate the activity of some Ca2+channels. Indeed, inhibition of ryanodine receptors, TRPV-or l-type Ca2+-channels shows a similar efficacy in reduction of positive inotropic effect of both fenoterol and H2O2. In addition, detection of mitochondrial ROS indicates that fenoterol triggers a slow increase in ROS which is prevented by rotenone, but rotenone has no impact on the inotropic effect of fenoterol. We suggest that stimulation of β2-adrenoceptor with fenoterol causes the activation of NADPH-oxidase and after the agonist removal extracellularly generated ROS penetrates into the cell, increasing the atrial contractions probably via Ca2+ channels.
Keywords: Fenoterol; β2-adrenoceptor; Atria; Contractility; NADPH oxidase; Reactive oxygen species;
Modulation of endoplasmic reticulum stress in Parkinson's disease by Saori Tsujii; Mitsue Ishisaka; Hideaki Hara (154-156).
Parkinson's disease is a neurodegenerative disease characterized by the loss of dopaminergic neurons in the substantia nigra in the midbrain. However, the etiology of the reduction in dopaminergic neurons remains unclear. Recently, it has been suggested that oxidative stress, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction are involved in neuronal cell death in the pathology of Parkinson's disease. Furthermore, it has been suggested that some existing anti- Parkinson's disease drugs have protective effects against cell death. Among these, zonisamide exerts neuroprotective effects partly by modulating ER stress. Elucidating the involvement of ER stress in in vitro and in vivo Parkinson's disease models and investigating the mechanisms against ER stress will contribute to the search for new therapeutic agents for Parkinson's disease.
Keywords: Endoplasmic reticulum stress; Parkinson's disease; Zonisamide;
Inhibition of microglia in the basolateral amygdala enhanced morphine-induced antinociception: Possible role of GABAA receptors by Nastaran Kosarmadar; Zahra Ghasemzadeh; Ameneh Rezayof (157-163).
In clinical medicine, morphine is widely used to relieve many types of pain, but it has several side effects such as the development of tolerance and dependence. In order to decrease the side effects of morphine administration for the treatment of pain, the combination of minocycline as a glial inhibitor and morphine has been suggested in previous studies. It is important to understand which synaptic mechanisms are involved in the potentiative effect of minocycline on morphine antinociception. To this aim, male Wistar rats were bilaterally cannulated in the basolateral amygdala by srereotaxic instrument. A tail-flick apparatus was used to measure the pain threshold. The results revealed that intraperitoneal injection of morphine (2.5–7.5 mg/kg) induced antinociception. Intra-basolateral amygdala microinjection of minocycline (5–10 µg/rat) by itself had no effect on tail-flick latency, while the microinjection of the same doses of minocycline with an ineffective dose of morphine (5 mg/kg) induced antinociception. Intra-basolateral amygdala microinjection of different doses of muscimol (0.001–0.005 µg/rat) increased the minocycline-induced potentioation on morphine response in the tail-flick test. Intra-basolateral amygdala microinjection of muscimol by itself had no effect on tail-flick latency. On the other hand, intra-basolateral amygdala microinjection of bicuculline (0.01–0.1 µg/rat) inhibited minocycline-induced potentiation of morphine antinociception. It should be noted that intra-basolateral amygdala bicucculine by itself had no effect on tail-flick latency. It can thus be concluded that intra-basolateral amygdala minocycline potentiates morphine response in the tail-flick test. Moreover, basolateral amygdala GABAergic system may be involved in the minocycline-induced potentiation of morphine response via GABAA receptors.
Keywords: Basolateral amygdala; GABAA receptors; Minocycline; Morphine; Tail-flick test; Rat(s);
Matrix metalloproteinase inhibitors prevent sepsis-induced refractoriness to vasoconstrictors in the cecal ligation and puncture model in rats by Priscila de Souza; Richard Schulz; José Eduardo da Silva-Santos (164-170).
Previous studies have shown that the loss of contractility in aortas from lipopolysaccharide (LPS)-treated rats is related to intracellular activation of matrix metalloproteinase (MMPs). However, the role of MMPs in the vascular refractoriness to vasoconstrictors has not been investigated in a model of polymicrobial sepsis. We evaluated the effects of the oral administration of the MMP inhibitors doxycycline or ONO-4817 in the in vitro vascular reactivity of aortic rings from rats subjected to the cecal ligation and puncture (CLP) model of sepsis. Both doxycycline and ONO-4817 did not change vascular responses in sham-operated rats, but fully prevented hyporeactivity to KCl, phenylephrine and angiotensin II in vessels from CLP rats. This protective effect was not associated with changes in hematological parameters or blood nitrate and nitrite. The refractoriness to contractile agents was accompanied by enhanced activity of MMP-2 in aorta from CLP rats, which was abrogated by MMP inhibitors. CLP-induced sepsis did not impair the levels of MMP-2 in aorta, but significantly reduced calponin-1, a regulatory protein of vascular contraction. In addition, augmented levels of TIMP-1 were found in vessels from CLP rats. All these differences were prevented by either doxycycline or ONO-4817. Our study shows, for the first time in the CLP rat model of sepsis, that the vascular refractoriness to different contractile agents induced by polymicrobial sepsis is associated with increased activity of MMP-2 and reduced amounts of calponin-1 in the aorta. These findings reinforce the importance of the enhanced activity of MMPs for vascular failure in septic shock.
Keywords: Vasoplegia; Matrix metalloproteinase-2; Calponin-1; Septic shock;
Tumor suppression effects of myoepithelial cells on mice breast cancer by Baharak Farhanji; Mostafa Latifpour; Ali Mohammad Alizadeh; Hamid Khodayari; Saeed Khodayari; Mahmood Khaniki; Sarieh Ghasempour (171-178).
Several studies have assumed that myoepithelial cells (MECs) loss may contribute to epithelial tumor induction and/or progression. We adopted an in vitro assay and a syngeneic mice breast cancer model with histological and molecular characteristics resembling human lesions to evaluate tumor suppression effects of MECs. Flow cytometric, cell viability, blood chemistry, transmission electron microscope, immunohistochemistry and qRT-PCR assays were performed at the end of the study. We demonstrated that MECs could significantly suppress the viability of cancer cells at different time points (P<0.05). At the end of the fourth and fifth weeks, treated mice had smaller tumor volume compared with control animals. Average tumor volume was significantly less in treated groups than control group at days 21 (0.38±0.19 vs. 1.99±0.13 cm3), 28 (0.57±0.3 vs. 2.5±0.37 cm3) and 35 (0.7±0.35 vs. 2.65±0.4 cm3) after tumor cell injection (P<0.05). No hematological, hepatocellular, and renal toxicities were seen in MECs treated groups. Ultrastructural features revealed severe relationship between adjacent tumoral cells and loose interconnections of neoplastic cells in treated group. Immunohistochemical examinations of breast tumors showed high p63 and low alpha-smooth muscle actin protein expression in treated mice compared to control (P<0.05). MRNA expressions of TNF-α, smooth muscle–myosin heavy chain, connexin 43, and maspin were significantly up-regulated in breast tumor tissues in treated group compared to control (P<0.05). VEGF and alpha-smooth muscle actin mRNA expression were reduced in treated animals (P<0.05). The present study highlighted the potential tumor suppression effects of MECs on breast cancer in a typical animal model.
Keywords: Myoepithelial cell; Breast cancer; Mice;
Effects of exercise training together with tamoxifen in reducing mammary tumor burden in mice: Possible underlying pathway of miR-21 by Vahid Khori; Sadegh Amani Shalamzari; Amin Isanejad; Ali Mohammad Alizadeh; Shaban Alizadeh; Saeed Khodayari; Hamid Khodayari; Shirin Shahbazi; Ali Zahedi; Hamid Sohanaki; Mahmood Khaniki; Reza Mahdian; Mojtaba Saffari; Raja Fayad (179-187).
Exercise training has an anti-tumor effect and can reduce tumor growth; however, the exact underlying mechanisms of its protective effects are still obscure. MicroRNA (miR)-21 is a predictor in cancer survival, and has a potential use as an indicator of therapeutic outcome in breast malignancies. Forty-eight female BALB/c mice were equally divided into six groups to investigate the effects of interval exercise training with tamoxifen on miR-21 expression and its possible assumed mechanisms in an estrogen receptor-positive breast cancer model. ELISA, immunohistochemistry, western blot, qRT-PCR assays were performed at the end of the study. Tumor size was significantly declined in exercise training and tamoxifen groups compared to tumor group (P<0.05). Expression of miR-21 was significantly down-regulated in trained and tamoxifen treated mice in comparison with tumor group (P<0.05). Exercise training was as effective as tamoxifen treatment in decreasing serum estradiol and ER-α expression (P<0.05). Exercise training and tamoxifen reduced tumor IL-6 levels, NF-kB and STAT3 expressions, and up-regulated TPM1 and PDCD4 expressions (P<0.05). Both exercise and tamoxifen had synergistic effects in reducing miR-21 and Bcl-2, and up-regulating PDCD4 expression. Results showed that interval exercise training may reduce mammary tumor burden in mice through possible underlying pathway of miR-21.
Keywords: Interval exercise training; miR-21; Tamoxifen; Breast cancer;
Differences in gene expression and alterations in cell cycle of acute myeloid leukemia cell lines after treatment with JAK inhibitors by Pawel Gunerka; Barbara Dymek; Aleksandra Stanczak; Anna Bujak; Paulina Grygielewicz; Pawel Turowski; Karolina Dzwonek; Monika Lamparska-Przybysz; Tadeusz Pietrucha; Maciej Wieczorek (188-197).
Janus kinase (JAK) inhibitors are a promising treatment strategy in several hematological malignancies and autoimmune diseases. A number of inhibitors are in clinical development, and two have already reached the market. Unfortunately, all of them are burdened with different toxicity profiles. To check if the JAK inhibitors of different selectivity evoke different responses on JAK2-dependent and independent cells, we have used three acute myeloid leukemia cell lines with confirmed JAK2 mutation status. We have found that JAK inhibitors exert distinct effect on the expression of BCLXL, CCND1 and c-MYC genes, regulated by JAK pathway, in JAK2 wild type cells in comparison to JAK2 V617F-positive cell lines. Moreover, cell cycle analysis showed that inhibitors alter the cycle by arresting cells in different phases. Our results suggest that observed effect of JAK2 inhibitors on transcription and cell cycle level in different cell lines are associated not with activity within JAK family, but presumably with other off-target activities.
Keywords: Janus kinase; JAK inhibitors; Cell cycle; Cyclin D1; Aurora A kinase;
Mitomycin C induces fibroblasts apoptosis and reduces epidural fibrosis by regulating miR-200b and its targeting of RhoE by Yu Sun; Yingbin Ge; Yuxuan Fu; Lianqi Yan; Jun Cai; Kun Shi; Xiaojian Cao; Chun Lu (198-208).
Mitomycin C (MMC) is known to reduce epidural fibrosis, but the underlying mechanisms have not yet been elucidated. Aberrant miR-200b expressions have been reported in multiple types of fibrotic tissues from many diseases. The aim of this study was to clarify the mechanism by which MMC induces fibroblasts apoptosis and reduces epidural fibrosis. The expression of miR-200b in human fibroblasts was determined after MMC treatment, and the targeted association between miR-200b and RhoE was determined using the luciferase activity assay. The effects of MMC and miR-200b on human fibroblasts apoptosis were evaluated using flow cytometry and western blot analysis. The effects of MMC and miR-200b on epidural fibrosis were evaluated using the Rydell classification, hydroxyproline content, apoptotic cell count and histological analysis. The study revealed that MMC could significantly downregulate miR-200b expression and induce human fibroblasts apoptosis. The direct downregulation of miR-200b could induce human fibroblasts apoptosis. Furthermore, we identified the binding sequence for miR-200b within the 3′ untranslated region of RhoE. RhoE was confirmed to be a direct target of miR-200b, and RhoE itself acted as a promoter of fibroblasts apoptosis. The inhibition of miR-200b increased fibroblasts apoptosis and reduced epidural fibrosis in rats, which was in accordance with the effect of MMC. This study suggests that MMC induces fibroblasts apoptosis and reduces epidural fibrosis by regulating miR-200b expression and its targeting of RhoE.
Keywords: Mitomycin C; miR-200b; Fibroblasts apoptosis; RhoE; Epidural fibrosis;
Treatment with curcumin alleviates sublesional bone loss following spinal cord injury in rats by Xiaobin Yang; Baorong He; Peng Liu; Liang Yan; Ming Yang; Dichen Li (209-216).
This work aimed to investigate the therapeutic effect of curcumin on sublesional bone loss induced by spinal cord injury (SCI) in rats. SCI model in this work was generated in rats by surgical transaction of the cord at the T10–12 level. After the surgery, animals were treated with curcumin (110 mg/kg body mass/day, via oral gavages) for 2 weeks. Treatment of SCI rats with curcumin prevented the reduction of bone mass in tibiae and femurs, preserved bone microstructure including trabecular bone volume fraction, trabecular number, and trabecular thickness in proximal tibiae, and preserved mechanical properties of femoral midshaft. Treatment of SCI rats with curcumin increased osteoblast surface and reduced osteoclast surface in proximal tibiae. Treatment of SCI rats with curcumin increased osteocalcin mRNA expression and reduced mRNA levels of tartrate-resistant acid phosphatase and mRNA ratio of receptor activator of NF-κB ligand/osteoprotegerin in distal femurs. Treatment of SCI rats with curcumin reduced serum and femoral levels of thiobarbituric acid reactive substances. Treatment of SCI rats with curcumin had no significant effect on serum 25(OH)D, but enhanced mRNA and protein expression of vitamin D receptor (VDR) in distal femurs. Treatment of SCI rats with curcumin enhanced mRNA levels of Wnt3a, Lrp5, and ctnnb1 and upregulated protein expression of β-catenin in distal femurs. In conclusions, treatment with curcumin abated oxidative stress, activated VDR, and enhanced Wnt/β-catenin pathway, which might explain its beneficial effect against sublesional bone loss following SCI in rats, at least in part.
Keywords: Curcumin; Spinal cord injury; Vitamin D receptor; Oxidative stress; Wnt/β-catenin pathway;
Blockade of autophagy enhances proapoptotic potential of BI-69A11, a novel Akt inhibitor, in colon carcinoma by Ipsita Pal; Sheetal Parida; B.N. Prashanth Kumar; Payel Banik; Kaushik Kumar Dey; Sandipan Chakraborty; Sujit K Bhutia; Mahitosh Mandal (217-227).
BI-69A11, novel Akt inhibitor, is currently drawing much attention due to its intriguing effect in inducing apoptosis in melanoma, breast, prostate and colon cancer. However, earlier reports reveal that PI3K/Akt/ mTOR inhibitors promote autophagy at the early stage as a survival mechanism that might affect its apoptotic potential. It is necessary to investigate whether BI-69A11 mediated apoptosis is associated with autophagy for enhancing its therapeutic efficacy. Here, we found that BI-69A11 induced autophagy at earlier time point through the inhibition of Akt/mTOR/p70S6kinase pathway. Dose-dependent and time-dependent conversion of LC3-I to LC3-II, increased accumulation of LC3-GFP dots in cytoplasm and increase in other autophagic markers such as Beclin-1, firmly supported the fact that BI-69A11 induces autophagy. Atg5, Atg7 and Beclin-1 siRNA mediated genetic attenuation and pre-treatment with pharmacological inhibitor 3-MA and CQ diminished the autophagy and increased the propensity of cell death towards apoptosis. It was also suggested that BI-69A11 mediated interaction between Akt, HSP-90 and Beclin-1 maintained the fine balance between autophagy and apoptosis. Interaction between Beclin-1 and HSP90 is one of the prime causes of induction of autophagy. Here, we also generated a novel combination therapy by pretreatment with CQ that inhibited the autophagy and accelerated the apoptotic potential of BI-69A11. In summary; our findings suggest that induction of autophagy lead to the resistance of colon cancer towards BI-69A11 mediated apoptosis.
Keywords: Autophagy; Colon cancer; Apoptosis; Beclin-1; BI-69A11; HSP90;
The autotaxin–lysophosphatidic acid pathway in pathogenesis of rheumatoid arthritis by Beatriz Orosa; Samuel García; Carmen Conde (228-233).
Lysophosphatidic acid (LPA) is a phospholipid that is mainly produced by the hydrolysis of lysophosphatidylcholine (LPC) by lysophospholipase D, which is also called autotaxin (ATX). LPA interacts with specific G-protein coupled receptors and is involved in the regulation of cellular survival, proliferation, differentiation and motility. LPA also has roles in several pathological disorders, such as cancer and pulmonary, dermal and renal fibrosis. The involvement of the ATX–LPA pathway has recently been demonstrated in inflammatory responses and apoptosis of fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis and during the development of experimental arthritis. This review summarises the current literature of the ATX–LPA pathway in rheumatoid arthritis.
Keywords: Autotaxin; Experimental arthritis; ibroblast‐like; fibroblast like; Inflammatory response; Lysophosphatidic acid; Rheumatoid arthritis;
Artesunate alleviates hepatic fibrosis induced by multiple pathogenic factors and inflammation through the inhibition of LPS/TLR4/NF-κB signaling pathway in rats by Lina Lai; Yunxia Chen; Xiaoxia Tian; Xujiong Li; Xiaojing Zhang; Jingwen Lei; Yanghui Bi; Buwu Fang; Xiaoliang Song (234-241).
The current study was performed in order to explore the effect of artesunate (Art) on experimental hepatic fibrosis and the potential mechanism involved. Art, a water-soluble hemisuccinate derivative of artemisinin extracted from the Chinese herb Artemisia Annua, is a safe and effective antimalarial drug. Hepatic fibrosis was induced in SD rats by multiple pathogenic factors. Rats were treated concurrently with Art (28.8 mg/kg) given daily by oral gavage for 6 or 8 weeks to evaluate its protective effects. Our data demonstrated that Art treatment obviously attenuated hepatic fibrosis, characterized by less inflammatory infiltration and accumulation of extracellular matrix (ECM). Art remarkably decreased endotoxin, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels as well. Art significantly downregulated protein and mRNA expression of α-smooth muscle actin (α-SMA), toll-like receptors 4 (TLR4), myeloid differentiation factor 88 (MyD88) and transforming growth factor beta 1 (TGF-β1). Art also significantly inhibited the nuclear transcription factor kappa B p65 (NF-κB p65) translocation into the nucleus. In addition, there were no remarkable differences between the N group and the NA group. In conclusion, we found that Art could alleviate hepatic fibrosis induced by multiple pathogenic factors and inflammation through the inhibition of LPS/TLR4/NF-κB signaling pathway in rats, suggesting that Art may be a potential candidate for the therapy of hepatic fibrosis.
Keywords: Artesunate; Hepatic fibrosis; Inflammation; Endotoxin; Toll-like receptors;
Effects of ONO-6950, a novel dual cysteinyl leukotriene 1 and 2 receptors antagonist, in a guinea pig model of asthma by Yasuo Yonetomi; Tomohiko Sekioka; Michiaki Kadode; Tetsuya Kitamine; Akihiro Kamiya; Atsuto inoue; Takafumi Nakao; Hiroaki Nomura; Masayuki Murata; Shintaro Nakao; Fumio Nambu; Manabu Fujita; Shinji Nakade; Kazuhito Kawabata (242-248).
We assessed in this study the anti-asthmatic effects of ONO-6950, a novel cysteinyl leukotriene 1 (CysLT1) and 2 (CysLT2) receptors dual antagonist, in normal and S-hexyl glutathione (S-hexyl GSH)-treated guinea pigs, and compared these effects to those of montelukast, a CysLT1 selective receptor antagonist. Treatment with S-hexyl GSH reduced animals LTC4 metabolism, allowing practical evaluation of CysLT2 receptor-mediated airway response. ONO-6950 antagonized intracellular calcium signaling via human and guinea pig CysLT1 and CysLT2 receptors with IC50 values of 1.7 and 25 nM, respectively (human receptors) and 6.3 and 8.2 nM, respectively (guinea pig receptors). In normal guinea pigs, both ONO-6950 (1 or 0.3 mg/kg, p.o.) and the CysLT1 receptor antagonist montelukast (0.3 or 0.1 mg/kg, p.o.) fully attenuated CysLT1-mediated bronchoconstriction and airway vascular hyperpermeability induced by LTD4. On the other hand, in S-hexyl GSH-treated guinea pigs ONO-6950 at 3 mg/kg, p.o. or more almost completely inhibited bronchoconstriction and airway vascular hyperpermeability elicited by LTC4, while montelukast showed only partial or negligible inhibition of these airway responses. In ovalbumin sensitized guinea pigs, treatment with S-hexyl GSH on top of pyrilamine and indomethacin rendered antigen-induced bronchoconstriction sensitive to both CysLT1 and CysLT2 receptor antagonists. ONO-6950 strongly inhibited this asthmatic response to the level attained by combination therapy with montelukast and BayCysLT2RA, a selective CysLT2 receptor antagonist. These results clearly demonstrate that ONO-6950 is an orally active dual CysLT1/LT2 receptor antagonist that may provide a novel therapeutic option for patients with asthma.
Keywords: Asthma; CysLTs; CysLT2 receptor; CysLT1/LT2 receptor antagonist; ONO-6950; Glutathione;
Quetiapine mitigates the neuroinflammation and oligodendrocyte loss in the brain of C57BL/6 mouse following cuprizone exposure for one week by Yuan Shao; Hui Peng; Qingjun Huang; Jiming Kong; Haiyun Xu (249-257).
This study aimed at examining effects of quetiapine (QTP), an atypical antipsychotic, on the behaviors of mice which had consumed cuprizone (CPZ)-containing diet for one week and on inflammatory reactions and oligodendrocyte (OL) loss in brains of them. Young adult C57BL/6 mice, after fed CPZ-containing diet (0.2%, w/w) for one week, showed an increase in the locomotor activity in the open-field, and a decreased exploration time in the novel object recognition (NOR) test compared to controls. But, these changes were not seen in mice co-administered with QTP and CPZ. All mice in the four groups showed comparable performances in Y-maze test. After the behavioral tests, mice were killed and their brains were processed for immunohistochemical and immunofluorescence staining to examine OLs, astrocytes and microglia. The levels of proinflammatory cytokines TNF-α and IL-6 in certain brain regions were also evaluated by ELISA method. Mice in the NS+CPZ group showed fewer OLs, more activated astrocytes and microglia with higher immunofluorescence intensity in the examined brain regions of the corpus callosum, caudate putamen, cerebral cortex, and hippocampus. The levels of TNF-α and IL-6 in some of these brain regions were also increased. But these changes were completely blocked or effectively ameliorated in the QTP+CPZ group. These results demonstrated an anti-inflammatory effect of QTP in CPZ-exposed mice and this action may contribute to its protection on OLs and beneficial effects on the CPZ-induced behavioral changes in these mice.
Keywords: Antipsychotic; Cuprizone; Mice; Neuroinflammation; Oligodendrocytes; Schizophrenia;
Effect of combination therapy consisting of enalapril, α-lipoic acid, and menhaden oil on diabetic neuropathy in a high fat/low dose streptozotocin treated rat by Eric P. Davidson; Amey Holmes; Lawrence J. Coppey; Mark A. Yorek (258-267).
We have previously demonstrated that treating diabetic rats with enalapril, an angiotensin converting enzyme (ACE) inhibitor, α-lipoic acid, an antioxidant, or menhaden oil, a natural source of omega-3 fatty acids can partially improve diabetic peripheral neuropathy. In this study we sought to determine the efficacy of combining these three treatments on vascular and neural complications in a high fat fed low dose streptozotocin treated rat, a model of type 2 diabetes. Rats were fed a high fat diet for 8 weeks followed by a 30 mg/kg dose of streptozotocin. Eight weeks after the onset of hyperglycemia diabetic rats were treated with a combination of enalapril, α-lipoic acid and menhaden oil. Diabetic rats not receiving treatment were continued on the high fat diet. Glucose clearance was impaired in diabetic rats and significantly improved with treatment. Diabetes caused steatosis, elevated serum lipid levels, slowing of motor and sensory nerve conduction, thermal hypoalgesia, reduction in intraepidermal nerve fiber profiles, decrease in cornea sub-basal nerve fiber length and corneal sensitivity and impairment in vascular relaxation to acetylcholine and calcitonin gene-related peptide in epineurial arterioles of the sciatic nerve. Treating diabetic rats with the combination of enalapril, α-lipoic acid and menhaden oil reversed all these deficits to near control levels except for motor nerve conduction velocity which was also significantly improved compared to diabetic rats but remained significantly decreased compared to control rats. These studies suggest that a combination therapeutic approach may be most effective for treating vascular and neural complications of type 2 diabetes.
Keywords: Type 2 diabetes; Peripheral neuropathy; Corneal nerves; Insulin resistance; Enalapril; α-lipoic acid; Menhaden oil;
Genetic inactivation and prolonged pharmacologic inhibition of monoacylglycerol lipase have opposite effects on anesthetic sensitivity to propofol by Andrey B. Petrenko; Maya Yamazaki; Kenji Sakimura; Masanobu Kano; Hiroshi Baba (268-273).
Monoacylglycerol lipase (MGL) is a major enzyme involved in degradation of the endocannabinoid 2-arachidonoylglycerol (2-AG). Selective inhibitors of MGL are regarded as promising analgesics and anticancer agents. To gain insight into the possible consequences of their prolonged administration for anesthetic action, the effects of several inhalational and intravenous anesthetics were tested in knockout mice lacking the MGL gene in the loss of righting reflex (LORR) assay. Sensitivity to inhalational and most intravenous anesthetics was not altered in knockout mice. However, compared with wild-type littermates, they showed increased sensitivity to the intravenous anesthetic propofol. Permanently elevated levels of 2-AG after MGL knockout are known to cause desensitization of cannabinoid (CB1) receptors, which have been advocated as possible mediators of propofol anesthesia. Therefore, increased sensitivity to propofol in knockout mice at first suggested that 2-AG may potentiate CB1 receptors despite their hypofunction in these animals. Pharmacologic inhibition of MGL also causes desensitization of CB1 receptors, so sensitivity to propofol was tested further in C57BL/6N mice pretreated chronically with the selective MGL inhibitor JZL 184. Contrary to the results in knockout mice, these animals showed drastically reduced sensitivity to propofol. The reason for increased sensitivity to propofol after MGL knockout remains unclear, but may result from changes occurring in these animals during development. However, our results in C57BL/6N mice pretreated with JZL 184 confirmed the role of CB1 receptors in propofol anesthesia advocated previously, and also suggest that prolonged use of MGL inhibitors may be associated with the development of resistance to propofol.
Keywords: Monoacylglycerol lipase knockout mice; CB1 receptor desensitization; Anesthesia; Loss of righting reflex; General anesthetics; Propofol;
α2-Adrenergic modulation of the glutamate receptor and transporter function in a chronic ocular hypertension model by Kyoung In Jung; Jie Hyun Kim; Chan Kee Park (274-283).
Excitotoxicity, glutamate-induced toxic effects to retinal ganglion cells (RGCs), is one of several mechanisms of RGC loss suggested in glaucoma. In this study, we focused on the role of glutamate transporter of glial cells as well as N-methyl-d-aspartate (NMDA) receptor with regard to glutamate toxicity in glaucoma. We also investigated whether α2-adrenoceptor activation could modulate glutamate transporters and NMDA receptors in a chronic ocular hypertension model. Brimonidine 0.15% was administered topically to the eyes of experimental glaucoma and control animals twice daily. After 8 weeks of intraocular pressure (IOP) elevation, staining with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) revealed an increase in the ganglion cell layer, and the number of TUNEL-positive cells was reduced by brimonidine treatment (P<0.05). Animals with experimentally induced glaucoma exhibited an increase in retinal stress marker glial fibrillary acidic protein (GFAP) immunoreactivity; brimonidine treatment reduced GFAP. Excitatory amino acid transporter 1(EAAT1) expression remained stable throughout the period of chronic ocular hypertension. α2-Adrenergic treatment upregulated EAAT1 protein levels (P<0.05). NMDA receptor (GluN1) expression was stimulated by chronic elevation of IOP, and GluN1-positive cells in ganglion cell layer were co-localized with TUNEL staining. Brimonidine administration suppressed GluN1 levels (P<0.05). These results indicate that brimonidine decreased RGC apoptosis, upregulating EAAT1 and downregulating NMDA receptors. We suggest that topical brimonidine treatment may decrease the glutamate excitotoxicity through modulation of glutamate transporter and NMDA receptor in glaucoma.
Keywords: Glaucoma; Brimonidine; Glutamate excitotoxicity; Retinal ganglion cell; GluN1; EAAT1;
Neuroprotective effects of an oxyntomodulin analogue in the MPTP mouse model of Parkinson's disease by WeiZhen Liu; Yanwei Li; Jaishree Jalewa; Taylor Saunders-Wood; Lin Li; Christian Hölscher (284-290).
Oxyntomodulin is a hormone and a growth factor. It activates two receptors, the Glucagon-like peptide 1 (GLP-1) and the glucagon receptor. GLP-1 mimetics are on the market as treatments for type 2 diabetes and are well tolerated. These drugs have shown neuroprotective properties in animal models of neurodegenerative disorders. In addition, the GLP-1 mimetic exendin-4 has shown protective effects in animal models of Parkinson's disease (PD), and a clinical trial in PD patients showed promising first positive results. d-Ser2-oxyntomodulin (Oxy) is a protease resistant oxyntomodulin analogue that has been developed to treat diabetes. Here we demonstrate for the first time that such analogues have neuroprotective effects. The drug showed protective effects in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. MPTP was injected daily (20 mg/kg i.p.) for 7 days, and Oxy injected once-daily for 14 days i.p. Oxy treatment prevented or reversed the MPTP- induced motor impairment (Rotarod, spontaneous locomotion, swim activity, muscle strength test), the MPTP-induced reduction in Tyrosine Hydroxylase (TH) levels (dopamine synthesis) in the substantia nigra and basal ganglia, the reduction of the synaptic marker synapstophysin, the inactivation of the growth factor kinase Akt/PKB and of the anti-apoptotic signaling molecule Bcl-2, and the increase of levels of the pro-inflammatory cytokine TNF-α. The results demonstrate that oxyntomodulin analogues show promise as a novel treatment of PD.
Keywords: Growth factor; Incretin; GLP-1; Glucagon; Insulin; Neurodegeneration; Mice;
Subcellular localization and internalization of the vasopressin V1B receptor by Aki Kashiwazaki; Yoko Fujiwara; Hiroyoshi Tsuchiya; Nobuya Sakai; Katsushi Shibata; Taka-aki Koshimizu (291-299).
Only limited information is available on agonist-dependent changes in the subcellular localization of vasopressin V1B receptors. Our radioligand binding study of membrane preparations and intact cells revealed that a large fraction of the V1B receptor is located in the cytoplasm in unstimulated CHO cells, which is in contrast to the plasma membrane localization of the V1A and V2 receptors. Moreover, when the affinity of radiolabeled arginine-vasopressin ([3H]AVP) was compared between membrane preparations and intact cells, the affinity of [3H]AVP to the cell surface V1B receptors, but not the V1A receptors, was significantly reduced. Although the number and affinity of cell surface V1B receptors decreased, they became extensively internalized upon binding with [3H]AVP. Approximately 87% of cell surface-bound [3H]AVP was internalized and became resistant to acid wash during incubation with 1 nM [3H]AVP. By contrast, less ligand (35%) was internalized in the cells expressing the V1A receptor. Extensive internalization of the V1B receptors was partially attenuated by inhibitors of cytoskeletal proteins, siRNA against β-arrestin 2, or the removal of sodium chloride from the extracellular buffer, indicating that this internalization involves clathrin-coated pits. Together, these results indicate that the mechanism that regulates the number and affinity of V1B receptors in the plasma membrane is markedly distinct from the corresponding mechanisms for the V1A and V2 receptors and plays a critical role under stress conditions, when vasopressin release is augmented.
Keywords: V1B vasopressin receptor; Internalization; Receptor trafficking; Radioligand binding; Acid wash; Stable expression;
The antipsychotic aripiprazole induces antinociceptive effects: Possible role of peripheral dopamine D2 and serotonin 5-HT1A receptors by Ana F. Almeida-Santos; Renata C.M. Ferreira; Igor D. Duarte; Daniele C. Aguiar; Thiago R.L. Romero; Fabricio A. Moreira (300-306).
Aripiprazole is an antipsychotic that acts by multiple mechanisms, including partial agonism at dopamine D2 and serotonin 5-HT1A receptors. Since these neurotransmitters also modulate pain and analgesia, we tested the hypothesis that systemic or local administration of aripiprazole induces antinociceptive responses. Systemic aripiprazole (0.1–10 mg/kg; i.p.) injection in mice inhibited formalin-induced paw licking and PGE2-induced hyperalgesia in the paw pressure test. This effect was mimicked by intra-plantar administration (12.5–100 µg/paw) in the ipsi, but not contralateral, paw. The peripheral action of aripiprazole (100 µg/paw) was reversed by haloperidol (0.1–10 µg/paw), suggesting the activation of dopamine receptors as a possible mechanism. Accordingly, quinpirole (25–100 µg/paw), a full agonist at D2/D3 receptors, also reduced nociceptive responses.. In line with the partial agoniztic activity of aripiprazole, low dose of this compound inhibited the effect of quinpirole (both at 25 µg/paw). Finally, peripheral administration of NAN-190 (0.1–10 μg/paw), a 5-HT1A antagonist, also prevented aripiprazole-induced antinociception. In conclusion, systemic or local administration of aripiprazole induces antinociceptive effects. Similar to its antipsychotic activity, the possible peripheral mechanism involves dopamine D2 and serotoninergic 5-HT1A receptors. Aripiprazole and other dopaminergic modulators should be further investigated as new treatments for certain types of pain.
Keywords: Partial agonist; Nociception; Analgesia; Dopamine; Serotonin;
Ramipril and haloperidol as promising approaches in managing rheumatoid arthritis in rats by Mariam Gamal Fahmy Wahba; Basim Anwar Shehata Messiha; Ali Ahmed Abo-Saif (307-315).
Rheumatoid arthritis (RA) is a challenging autoimmune disorder, whose treatments usually cause severe gastrointestinal, renal and other complications. We aimed to evaluate the beneficial anti-arthritic effects of an angiotensin converting enzyme (ACE) inhibitor, ramipril and a dopamine receptor blocker, haloperidol, on Complete Freund's Adjuvant-induced RA in adult female albino rats. Rats were allocated into a normal control group, an arthritis control group, two reference treatment groups receiving dexamethasone (1.5 mg/kg/day) and methotrexate (1 mg/kg/day), and two treatment groups receiving ramipril (0.9 mg/kg/day) and haloperidol (1 mg/kg/day). Serum rheumatoid factor, matrix metalloprotinease-3 (MMP-3) and cartilage oligomeric matrix protein as specific rheumatoid biomarkers, serum immunoglobulin G and antinuclear antibody as immunological biomarkers, serum tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10) as immunomodulatory cytokines, serum myeloperoxidase and C-reactive protein as inflammatory biomarkers, as well as malondialdehyde and glutathione reduced (GSH) as oxidative stress biomarkers were assessed. A histopathological study on joints and spleens was performed to support the results of biochemical estimations. Ramipril administration significantly corrected all the measured biomarkers, being restored back to normal levels except for MMP-3, TNF-α and IL-10. Haloperidol administration restored all the measured biomarkers back to normal levels except for TNF-α, IL-10 and GSH. In conclusion, ACE inhibitors represented by ramipril and dopamine receptor blockers represented by haloperidol may represent new promising protective strategies against RA, at least owing to their immunomodulatory, anti-inflammatory and antioxidant potentials.
Keywords: Rheumatoid arthritis; Dexamethasone; Methotrexate; Ramipril; Haloperidol; Rat;
Phosphorylation of GSK-3β and reduction of apoptosis as targets of troxerutin effect on reperfusion injury of diabetic myocardium by Behnaz Mokhtari; Reza Badalzadeh; Alireza Alihemmati; Mustafa Mohammadi (316-321).
Diabetes has various interactions with ischemic heart diseases. Troxerutin, a flavonoid, owns outstanding pharmacological potentials in cardiovascular medicine. The purpose of this study was to investigate the effects of troxerutin on phosphorylation of GSK-3β protein and apoptosis induced by myocardial ischemia–reperfusion injury in healthy and diabetic hearts. Male Wistar rats (n=36, 250–300 g) were randomly divided into four groups: healthy, diabetic, healthy-troxerutin and diabetic-troxerutin. Diabetes was induced by a single injection of streptozotocin (50 mg/kg; ip) and the diabetic period was lasted for ten weeks. Six weeks after induction of diabetes, troxerutin-treated groups received 150 mg/kg/day troxerutin by oral gavage for 4 weeks. The rats’ hearts were transferred to the Langendorff apparatus and then subjected to 30 min regional ischemia followed by 45 min reperfusion. Supernatants of the left ventricle were used to measure the levels of cardiac troponin-I (cTnI) by ELISA, total and phosphorylated form of GSK-3β by western blotting and tissue apoptosis by TUNEL assay. Troxerutin administration significantly decreased the cTnI levels in healthy and diabetic groups, as compared to the corresponding controls (P<0.05). In addition, troxerutin significantly increased the level of phosphorylated form and the ratio of phosphorylated to total form of GSK-3β in diabetic and control groups (P<0.05). Tissue apoptosis level and apoptotic index also showed a significant decrease after administration of troxerutin in control and diabetic groups (P<0.05). The findings indicated that the attenuation of GSK-3β activity and subsequent reduction of apoptosis by troxerutin play significant roles in its cardioprotection on reperfusion injuries.
Keywords: Ischemic heart disease; Diabetes; Troxerutin; Ischemia–reperfusion injury;
Selective androgen receptor modulator activity of a steroidal antiandrogen TSAA-291 and its cofactor recruitment profile by Yukiko Hikichi; Masuo Yamaoka; Masami Kusaka; Takahito Hara (322-331).
Selective androgen receptor modulators (SARMs) specifically bind to the androgen receptor and exert agonistic or antagonistic effects on target organs. In this study, we investigated the SARM activity of TSAA-291, previously known as a steroidal antiandrogen, in mice because TSAA-291 was found to possess partial androgen receptor agonist activity in reporter assays. In addition, to clarify the mechanism underlying its tissue selectivity, we performed comprehensive cofactor recruitment analysis of androgen receptor using TSAA-291 and dihydrotestosterone (DHT), an endogenous androgen. The androgen receptor agonistic activity of TSAA-291 was more obvious in reporter assays using skeletal muscle cells than in those using prostate cells. In castrated mice, TSAA-291 increased the weight of the levator ani muscle without increasing the weight of the prostate and seminal vesicle. Comprehensive cofactor recruitment analysis via mammalian two-hybrid methods revealed that among a total of 112 cofactors, 12 cofactors including the protein inhibitor of activated STAT 1 (PIAS1) were differently recruited to androgen receptor in the presence of TSAA-291 and DHT. Prostate displayed higher PIAS1 expression than skeletal muscle. Forced expression of the PIAS1 augmented the transcriptional activity of the androgen receptor, and silencing of PIAS1 by siRNAs suppressed the secretion of prostate-specific antigen, an androgen responsive marker. Our results demonstrate that TSAA-291 has SARM activity and suggest that TSAA-291 may induce different conformational changes of the androgen receptor and recruitment profiles of cofactors such as PIAS1, compared with DHT, to exert tissue-specific activity.
Keywords: Selective androgen receptor modulator; TSAA-291; Androgen receptor; Castrated mouse models; Mammalian two-hybrid system; Cofactor;
Drug–drug interactions between clopidogrel and novel cardiovascular drugs by Francesco Pelliccia; Fabiana Rollini; Giuseppe Marazzi; Cesare Greco; Carlo Gaudio; Dominick J. Angiolillo (332-336).
The combination of aspirin and the thienopyridine clopidogrel is a cornerstone in the prevention of atherothrombotic events. These two agents act in concert to ameliorate the prothrombotic processes stimulated by plaque rupture and vessel injury complicating cardiovascular disease. Guidelines recommend the use of clopidogrel in patients with acute coronary syndromes and in those undergoing percutaneous coronary intervention, and the drug remains the most utilized P2Y12 receptor inhibitor despite the fact that newer antiplatelet agents are now available. In recent years, numerous studies have shown inconsistency in the efficacy of clopidogrel to prevent atherothrombotic events. Studies of platelet function testing have shown variability in the response to clopidogrel. One of the major reason for this phenomenon lies in the interaction between clopidogrel and other drugs that may affect clopidogrel absorption, metabolism, and ultimately its antiplatelet action. Importantly, these drug–drug interactions have prognostic implications, since patients with high on-treatment platelet reactivity associated with reduced clopidogrel metabolism have an increased risk of ischemia. Previous systematic reviews have focused on drug–drug interactions between clopidogrel and specific pharmacologic classes, such as proton pump inhibitors, calcium channel blockers, and statins. However, more recent pieces of scientific evidence show that clopidogrel may also interact with newer drugs that are now available for the treatment of cardiovascular patients. Accordingly, the aim of this review is to highlight and discuss recent data on drug–drug interactions between clopidogrel and third-generation proton pump inhibitors, pantoprazole and lansoprazole, statins, pitavastatin, and antianginal drug, ranolazine.
Keywords: Clopidogrel; Drug–drug interaction; Dual antiplatelet therapy; Platelet reactivity;
A functional tandem between transient receptor potential canonical channels 6 and calcium-dependent chloride channels in human epithelial cells by Johanna Bertrand; Luc Dannhoffer; Fabrice Antigny; Laura Vachel; Christophe Jayle; Clarisse Vandebrouck; Frédéric Becq; Caroline Norez (337-345).
TRPC6 plays important human physiological functions, notably in artery and arterioles constriction, in regulation of vascular volume and in bronchial muscle constriction. It is implicated in pulmonary hypertension, cardiovascular disease, and focal segmental glomerulosclerosis and seems to play a role in cancer development. Previously, we identified Guanabenz, an α2-adrenergic agonist used for hypertension treatment (Wytensin®), as an activator of calcium-dependent chloride channels (CaCC) in human Cystic Fibrosis (CF) nasal epithelial cells by transiently increasing [Ca2+]i via an influx of extracellular Ca2+. In this study, using assays to measure chloride channel activity, we show that guanabenz is an activator of CaCC in freshly dissociated human bronchial epithelial cells from three CF patients with various genotypes (F508del/F508del, F508del/R1066C, F508del/H1085R). We further characterised the effect of guanabenz and show that it is independent of α-adrenergic receptors, is inhibited by the TRPC family inhibitor SKF-96365 but not by the TRPV family inhibitor ruthenium red. Using western-blotting, Ca2+ measurements and iodide efflux assay, we found that TRPC1 siRNA has no effect on guanabenz induced responses whereas TRPC6 siRNA prevented the guanabenz-dependent Ca2+ influx and the CaCC-dependent activity stimulated by guanabenz. In conclusion, we show that TRPC6 channel is pivotal for the activation of CaCC by guanabenz through a α2-adrenergic-independent pathway in human airway epithelial cells. We suggest propose a functional coupling between TRPC6 and CaCC and guanabenz as a potential TRPC6 activator for exploring TRPC6 and CaCC channel functions and corresponding channelopathies.
Keywords: Calcium-activated chloride channel; Transient receptor potential canonical channel; Cystic fibrosis; Human airway epithelial cells; Pharmacology;
Silibinin-induced glioma cell apoptosis by PI3K-mediated but Akt-independent downregulation of FoxM1 expression by Mingjie Zhang; Yunhui Liu; Yun Gao; Shaoyi Li (346-354).
The oncogenic transcription factor Forkhead box M1 (FoxM1) is overexpressed in many human tumors, including glioma. As a critical regulator of the cell cycle and apoptosis-related genes, FoxM1 is a potential therapeutic target against human malignant glioma. Silibinin, a flavonoid isolated from Silybum marianum, dose-dependently reduced glioma cell proliferation, promoted apoptosis, and downregulated FoxM1 expression. Knockdown of FoxM1 by small hairpin RNA (shRNA) transfection also promoted glioma cell apoptosis and augmented the antiproliferative and pro-apoptotic properties of silibinin. Moreover, silibinin increased caspase-3 activation, upregulated pro-apoptotic Bax, and suppressed anti-apoptotic Bcl-2 expression, effects enhanced by FoxM1 knockdown. Silibinin treatment suppressed U87 cell PI3K phospho-activation, and simultaneous silibinin exposure, FoxM1 knockdown, and PI3K inhibition additively increased U87 cell apoptosis. Furthermore, PI3K inhibition reduced FoxM1 expression. Akt activity was also suppressed by FoxM1 downregulation but Akt inhibition did not alter FoxM1 expression. Thus, silibinin likely inhibited glioma cell proliferation and induced apoptosis through inactivation of PI3K and FoxM1, leading to activation of the mitochondrial apoptotic pathway. FoxM1 may be a novel target for chemotherapy against human glioma.
Keywords: FoxM1; Silibinin; PI3K; Akt; apoptosis;
Differential effects of anti-TNF-α and anti-IL-12/23 agents on human leukocyte–endothelial cell interactions by Cesar Ríos-Navarro; Carmen de Pablo; Víctor Collado-Diaz; Samuel Orden; Ana Blas-Garcia; María Ángeles Martínez-Cuesta; Juan V. Esplugues; Angeles Alvarez (355-365).
Enhanced leukocyte recruitment is an inflammatory process that occurs during early phases of the vascular dysfunction that characterises atherosclerosis. We evaluated the impact of anti-TNF-α (adalimumab, infliximab and etanercept) and anti-IL-12/23 (ustekinumab) on interactions between human leukocytes and endothelial cells in a flow chamber that reproduced in vivo conditions. Clinical concentrations of anti-TNF-α were evaluated on the leukocyte recruitment induced by a variety of endothelial (TNF-α, interleukin-1β, lymphotoxin-α and angiotensin-II) and leukocyte (PAF, IL-12 and IL-23) stimuli related to inflammation and atherosclerosis. Treatment with anti-TNF-α, even before or after establishing the inflammatory situation induced by TNF-α, diminished leukocyte–endothelial cell interactions induced by this stimuli. Our results also implicated adhesion molecules (ICAM-1, VCAM-1 and E-selectin) in the actions of anti-TNF-α in terms of leukocyte adhesion to endothelium. However, anti-TNF-α drugs did not influence the actions of interleukin-1β, but prevented those of lymphotoxin-α and angiotensin-II. However, once established, inflammatory response elicited by the latter three stimuli could not be reversed. Pre-treatment with anti-TNF-α, also prevented leukocyte actions induced by IL-23 on PBMC rolling flux and rolling velocity and by IL-12 on PMN adhesion. Ustekinumab exhibited a more discreet profile, having no effect on leukocyte recruitment induced by any of the endothelial stimuli, while blocking the effects of IL-23 on leukocyte activation and those of IL-12 on PMN adhesion and PAF on PBMC rolling velocity. These findings endorse the idea that biological anti-inflammatory drugs, in particular anti-TNF-α, have the capacity to influence cardiovascular risk accompanying psoriasis and rheumatoid arthritis by ameliorating vascular inflammation.
Keywords: Rheumatic diseases; Biologics; Anti-TNF-α agents; Anti-IL-12/23 agents; Cardiovascular side effects; Leukocyte–endothelial cell interactions;
Future therapeutic targets for the treatment and prevention of cholesterol gallstones by Ibrahim Guillermo Castro-Torres; René de Jesús Cárdenas-Vázquez; Claudia Velázquez-González; Rosa Ventura-Martínez; Minarda De la O-Arciniega; Elia Brosla Naranjo-Rodríguez; Mariano Martínez-Vázquez (366-374).
The formation of cholesterol gallstones involves very complex imbalances, such as alterations in the secretion of biliary lipids (which involves the ABCG5, ABCG8, ABCB4 and ABCB11 transporters), biochemical and immunological reactions in the gallbladder that produce biliary sludge (mucins), physicochemical changes in the structure of cholesterol (crystallization), alterations in gallbladder motility, changes in the intestinal absorption of cholesterol (ABCG5/8 transporters and Niemann–Pick C1L1 protein) and alterations in small intestine motility. Some of these proteins have been studied at the clinical and experimental levels, but more research is required. In this review, we discuss the results of studies on some molecules involved in the pathophysiology of gallstones that may be future therapeutic targets to prevent the development of this disease, and possible sites for treatment based mainly on the absorption of intestinal cholesterol (Niemann–Pick C1L1 and ABCG5/8 proteins).
Keywords: Pathophysiology; Gallstones; Cholesterol; Therapeutic target;
Chronic fluoxetine treatment increases NO bioavailability and calcium-sensitive potassium channels activation in rat mesenteric resistance arteries by Camila A. Pereira; Nathanne S. Ferreira; Fabiola L. Mestriner; José Antunes-Rodrigues; Paulo R.B. Evora; Leonardo B.M. Resstel; Fernando S. Carneiro; Rita C. Tostes (375-383).
Fluoxetine, a selective serotonin reuptake inhibitor (SSRI), has effects beyond its antidepressant properties, altering, e.g., mechanisms involved in blood pressure and vasomotor tone control. Although many studies have addressed the acute impact of fluoxetine on the cardiovascular system, there is a paucity of information on the chronic vascular effects of this SSRI. We tested the hypothesis that chronic fluoxetine treatment enhances the vascular reactivity to vasodilator stimuli by increasing nitric oxide (NO) signaling and activation of potassium (K+) channels. Wistar rats were divided into two groups: (I) vehicle (water for 21 days) or (II) chronic fluoxetine (10 mg/kg/day in the drinking water for 21 days). Fluoxetine treatment increased endothelium-dependent and independent vasorelaxation (analyzed by mesenteric resistance arteries reactivity) as well as constitutive NO synthase (NOS) activity, phosphorylation of eNOS at Serine1177 and NO production, determined by western blot and fluorescence. On the other hand, fluoxetine treatment did not alter vascular expression of neuronal and inducible NOS or guanylyl cyclase (GC). Arteries from fluoxetine-treated rats exhibited increased relaxation to pinacidil. Increased acetylcholine vasorelaxation was abolished by a calcium-activated K+ channel (KCa) blocker, but not by an inhibitor of KATP channels. On the other hand, vascular responses to Bay 41-2272 and 8-bromo-cGMP were similar between the groups. In conclusion, chronic fluoxetine treatment increases endothelium-dependent and independent relaxation of mesenteric resistance arteries by mechanisms that involve increased eNOS activity, NO generation, and KCa channels activation. These effects may contribute to the cardiovascular effects associated with chronic fluoxetine treatment.
Keywords: Fluoxetine; Chronic treatment; Vascular reactivity; Nitric oxide; Potassium channel;
The role of thioredoxin reductase and glutathione reductase in plumbagin-induced, reactive oxygen species-mediated apoptosis in cancer cell lines by Geun Hye Hwang; Jung Min Ryu; Yu Jin Jeon; Joonhyeok Choi; Ho Jae Han; You-Mie Lee; Sangkyu Lee; Jong-Sup Bae; Jong-Wha Jung; Woochul Chang; Lark Kyun Kim; Jun-Goo Jee; Min Young Lee (384-393).
Plumbagin is a secondary metabolite that was first identified in the Plumbago genus of plants. It is a naphthoquinone compound with anti-atherosclerosis, anticancer, anti-inflammatory, antimicrobial, contraceptive, cardiotonic, immunosuppressive, and neuroprotective activities. However, the mechanisms of plumbagin's activities are largely unknown. In this study, we examined the effect of plumbagin on HepG2 hepatocellular carcinoma cells as well as LLC lung cancer cells, SiHa cervical carcinoma cells. Plumbagin significantly decreased HepG2 cell viability in a dose-dependent manner. Additionally, treatment with plumbagin significantly increased the Bax/Bcl-2 ratio and caspase-3/7 activity. Using the similarity ensemble approach (SEA)—a state-of-the-art cheminformatic technique-we identified two previously unknown cellular targets of plumbagin: thioredoxin reductase (TrxR) and glutathione reductase (GR). This was then confirmed using protein- and cell-based assays. We found that plumbagin was directly reduced by TrxR, and that this reduction was inhibited by the TrxR inhibitor, sodium aurothiomalate (ATM). Plumbagin also decreased the activity of GR. Plumbagin, and the GR inhibitor sodium arsenite all increased intracellular reactive oxygen species (ROS) levels and this increase was significantly attenuated by pretreatment with the ROS scavenger N-acetyl-cysteine (NAC) in HepG2 cells. Plumbagin increased TrxR-1 and heme oxygenase (HO)-1 expression and pretreatment with NAC significantly attenuated the plumbagin-induced increase of TrxR-1 and HO-1 expression in HepG2 cells, LLC cells and SiHa cells. Pretreatment with NAC significantly prevented the plumbagin-induced decrease in cell viability in these cell types. In conclusion, plumbagin exerted its anticancer effect by directly interacting with TrxR and GR, and thus increasing intracellular ROS levels.
Keywords: Plumbagin; Thioredoxin reductase; Glutathione reductase; Reactive oxygen species; Anticancer;
Silibinin alleviates high glucose-suppressed osteogenic differentiation of human bone marrow stromal cells via antioxidant effect and PI3K/Akt signaling by Xiaozhou Ying; Xiaowei Chen; Haixiao Liu; Pengfei Nie; Xiaolong Shui; Yue Shen; Kehe Yu; Shaowen Cheng (394-401).
High glucose is one of the possible causes for osteoporosis and fracture in diabetes mellitus. Our previous study showed that silibinin can increase osteogenic effect by stimulating osteogenic genes expression in human bone marrow stem cells (hBMSCs). However, no study has yet investigated the effect of silibinin on osteogenic differentiation of hBMSCs cultured with high glucose. The aim of this study was to evaluate the influence of high glucose on osteogenic differentiation of hBMSCs and to determine if silibinin can alleviate those effects. In this study, the hBMSCs were cultured in an osteogenic medium with physiological (normal glucose, NG, 5.5 mM) or diabetic (high glucose, HG, 30 mM). The effects of silibinin on HG-induced osteogenic differentiation were evaluated by alkaline phosphatas (ALP) activity assay, Von Kossa staining and real time-polymerase chain reaction. HG-induced oxidative damage was also assessed. Western blot were performed to examine the role of PI3K/Akt pathway. We demonstrated that HG suppressed osteogenic differentiation of hBMSCs, manifested by a decrease in expression of osteogenic markers and an increase of oxidative damage markers including reactive oxygen species and lipid peroxide (MDA). Remarkably, all of the observed oxidative damage and osteogenic dysfunction induced by HG were inhibited by silibinin. Furthermore, the PI3K/Akt pathway was activated by silibinin. These results demonstrate that silibinin may attenuate HG-mediated hBMSCs dysfunction through antioxidant effect and modulation of PI3K/Akt pathway, suggesting that silibinin may be a superior drug candidate for the treatment of diabetes related bone diseases.
Keywords: Silibinin; High glucose (HG); PI3K/Akt pathway; Antioxidant; Osteoporosis;
Olopatadine hydrochloride suppresses hot flashes induced by topical treatment with tacrolimus ointment in rats by Kyosuke Satake; Junichi Ikeda; Tadafumi Tamura; Toru Amano; Katsuya Kobayashi (402-405).
Tacrolimus ointment is prescribed for patients with atopic dermatitis, although it is known to cause transient burning sensations and hot flashes in the applied skin. The aim of this study was to evaluate the effects of olopatadine hydrochloride (olopatadine), an antiallergic agent with a histamine H1 receptor (H1R) antagonistic activity, on the incidence of hot flashes induced by topical treatment with tacrolimus ointment in rats. Consequently, the skin temperature was increased by the topical application of tacrolimus ointment in rats, and the rise in skin temperature was inhibited by pretreatment with olopatadine in a dose-dependent manner. Inhibitory effect of olopatadine on tacrolimus-induced skin temperature elevation was significantly more potent than that of cetirizine hydrochloride, other antiallergic agent with H1R antagonistic activity, at doses in which both agents exhibit comparable H1R antagonistic activity in rats. These results suggest that H1R antagonistic activity-independent mechanism contribute to the inhibitory effect of olopatadine on tacrolimus-induced skin temperature elevation. Olopatadine also significantly inhibited increases in vascular permeability and nerve growth factor production in the skin induced by topical tacrolimus treatment. Thus, the onset of hot flashes in rats is quantitatively determined by measuring the skin temperature and olopatadine attenuates hot flashes induced by topical tacrolimus ointment in rats, suggesting that the combination application with olopatadine and tacrolimus ointment is useful for improving medication adherence with tacrolimus ointment treatment in patients with atopic dermatitis.
Keywords: Tacrolimus ointment; Olopatadine; Atopic dermatitis; Hot flashes; Vascular permeability; NGF;
Recent advances in stress research: Focus on nitric oxide by Kavita Gulati; Jagdish Chandra Joshi; Arunabha Ray (406-414).
Stress and stress related disorders are a major cause of morbidity and mortality and understanding stress mechanisms is of great importance for devising appropriate therapeutic measures in such situations. The brain and its complex neurotransmitter systems regulate physiological and behavioral responses to a variety of stressors. Several other factors like age, gender and emotionality of the organism, as well as type, intensity and duration of the stressor may decide the nature and extent of stress effects. Nitric oxide (NO) is widely distributed in the brain and its role in Central nervous system (CNS) pathophysiology has been suggested. Recent studies have shown that free radicals and in particular NO may play a crucial role in the regulation of stress effects. All the various factors, mentioned above, that might influence stress responsiveness have been discussed with reference to regulatory role of NO during stress and it appears that NO may act as a therapeutic target for development of novel strategies against stress related disorders.
Keywords: Stress; Nitric oxide; Age; Gender; Stressor;
Statin-mediated inhibition of cholesterol synthesis induces cytoprotective autophagy in human leukemic cells by Urosh Vilimanovich; Mihajlo Bosnjak; Andrija Bogdanovic; Ivanka Markovic; Aleksandra Isakovic; Tamara Kravic-Stevovic; Aleksandar Mircic; Vladimir Trajkovic; Vladimir Bumbasirevic (415-428).
Statins exhibit anti-leukemic properties due to suppression of the mevalonate pathway by the inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase, and subsequent depletion of cholesterol, farnesylpyrophosphate, and geranylgeranylpyrophosphate. We investigated the role of autophagy, a controlled intracellular self-digestion, in the anti-leukemic action of statins. Treatment with low concentrations (≤6 µM) of statins, cholesterol depletion, and specific inhibition of cholesterol synthesis and protein farnesylation or geranylgeranylation, all inhibited proliferation of leukemic cell lines and primary leukemic cells without inducing overt cell death. Statins and agents that selectively reduce intracellular cholesterol levels, but not the inhibition of protein farnesylation or geranylgeranylation, induced autophagy in leukemic cells. The observed autophagic response was associated with the reduction of phosphorylated Akt levels in the lipid rafts, accompanied by a decrease in the activation of the main autophagy suppressor mammalian target of rapamycin (mTOR) and its substrate ribosomal p70S6 kinase (p70S6K). No significant autophagy induction and downregulation of mTOR/p70S6K activation were observed in normal leukocytes. Autophagy suppression by bafilomycin A1 or RNA interference-mediated knockdown of beclin-1 and microtubule-associated protein 1 light chain 3B induced apoptotic death in statin-treated leukemic cells, an effect attenuated by the addition of mevalonate or squalene, but not farnesylpyrophosphate or geranylgeranylpyrophosphate. Therefore, while the inhibition of cholesterol synthesis, protein farnesylation, and geranylgeranylation all contributed to anti-leukemic effects of statins, the inhibition of cholesterol synthesis was solely responsible for the induction of cytoprotective autophagy. These data indicate that combined treatment with statins and autophagy inhibitors might be potentially useful in anti-leukemic therapy.
Keywords: Statins; Leukemia; Autophagy; Apoptosis; Cholesterol;
Single inhibition of either PDE3 or PDE4 unmasks β2-adrenoceptor-mediated inotropic and lusitropic effects in the left but not right ventricular myocardium of rat by Fernando Soler; Francisco Fernández-Belda; Joaquín Pérez-Schindler; Jesús Hernández-Cascales (429-436).
Cyclic nucleotide phosphodiesterase (PDE)3 and PDE4 provide the major PDE activity in cardiac myocytes and shape β1-adrenoceptor-dependent cardiac cAMP signaling but their role in regulating β2-adrenoceptor-mediated responses is less well known. We investigated potential differences in PDE3 and PDE4 activities between right (RV) and left (LV) ventricular myocardium, and their role in regulating β2-adrenoceptor effects. PDE3 activity in the microsomal fraction was lower in RV than in LV but was the same in the cytosolic fraction. However, no significant difference between RV and LV was found when the PDE4 activity was studied. β2-adrenoceptor activation increased inotropism and lusitropism in LV when measured in the presence of either the PDE3 inhibitor cilostamide, the PDE4 inhibitor rolipram or a non-selective PDE inhibitor IBMX. However, the joint inhibition of both PDE3 and PDE4 was necessary in RV to uncover β2-adrenoceptor-induced inotropic and lusitropic effects. Our results indicate different regulation of β2-adrenoceptor-mediated contractility by PDE3 and PDE4 in RV and LV of the rat heart. In the case of PDE3 due to a different contribution of the enzyme in the microsomal fraction whereas in the case of PDE4 it can be attributed to differences in the intracellular distribution and coupling to β2-adrenoceptors.
Keywords: PDE3-4 activities; β2-adrenoceptor activation; Inotropy; Lusitropy; Interventricular difference;
Tanshinone II A, a multiple target neuroprotectant, promotes caveolae-dependent neuronal differentiation by Yuming Zhao; Pingxiang Xu; Shengquan Hu; Libo Du; Zhiqing Xu; Huan Zhang; Wei Cui; Shinghung Mak; Daping Xu; Jianggang Shen; Yifan Han; Yang Liu; Ming Xue (437-446).
Neuron loss is one fundamental features of neurodegenerative diseases. Stimulating endogenous neurogenesis, especially neuronal differentiation, might potentially provide therapeutic effects to these diseases. In this study, tanshinone II A (TIIA), a multiple target neuroprotectant, was demonstrated to promote dose-dependent neuronal differentiation in three cell models of immortalized C17.2 neuronal stem cells, rat embryonic cortical neural stem cells (NSCs) and rat PC12 pheochromocytoma cells. In particular, TIIA exerted promising effects on NSCs even at the dose of 3 nM. In PC12 cells, TIIA activated mitogen-activated protein kinase 42/44 (MAPK42/44) and its downstream transcription factor, cAMP response element-binding protein (CREB). In addition, TIIA up-regulated the expressions of brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF). The MEK inhibitor and the antagonist to the receptors of NGF and BDNF could partially attenuate the differentiation effects, indicating that MAPK42/44 mediated BDNF and NGF signals were involved in TIIA's differentiation effects. Caveolin-1 (CAV-1), the major functional protein of membrane caveolae, plays critical roles in the endocytosis of exogenous materials. CAV1, which was activated by TIIA, might help TIIA transport across cell membrane to initiate its differentiation effects. It was proven by the evidences that suppressing the function of caveolin inhibited the differentiation effects of TIIA. Therefore, we concluded that TIIA promoted neuronal differentiation partially through MAPK42/44 mediated BDNF and NGF signals in a caveolae-dependent manner.Fig. 9 Summarized diagram illustrating that TIIA promoted neuronal differentiation and neurite outgrowth in a caveolae dependent manner. Activation of CAV1 might facilitate the endocytosis and transportation of TIIA. Afterwards, TIIA activated MAPK42/44/CREB pathway and enhanced the expressions of BDNF and NGF. The activated Trk receptors by NGF and BDNF might further activate MAPK/CREB signal and amplify the differentiation cascades and the related effects.Display Omitted
Keywords: Tanshinone II A; Neurodegeneration; Neuronal differentiation; Caveolin-1; BDNF; NGF;
Atorvastatin along with imipenem attenuates acute lung injury in sepsis through decrease in inflammatory mediators and bacterial load by Soumen Choudhury; Kannan Kandasamy; Bhojane Somnath Maruti; M. Pule Addison; Jaya Kiran Kasa; Sazad A. Darzi; Thakur Uttam Singh; Subhashree Parida; Jeevan Ranjan Dash; Vishakha Singh; Santosh Kumar Mishra (447-456).
Lung is one of the vital organs which is affected during the sequential development of multi-organ dysfunction in sepsis. The purpose of the present study was to examine whether combined treatment with atorvastatin and imipenem could attenuate sepsis-induced lung injury in mice. Sepsis was induced by caecal ligation and puncture. Lung injury was assessed by the presence of lung edema, increased vascular permeability, increased inflammatory cell infiltration and cytokine levels in broncho-alveolar lavage fluid (BALF). Treatment with atorvastatin along with imipenem reduced the lung bacterial load and pro-inflammatory cytokines (IL-1β and TNFα) level in BALF. The markers of pulmonary edema such as microvascular leakage and wet–dry weight ratio were also attenuated. This was further confirmed by the reduced activity of MPO and ICAM-1 mRNA expression, indicating the lesser infiltration and adhesion of inflammatory cells to the lungs. Again, expression of mRNA and protein level of iNOS in lungs was also reduced in the combined treatment group. Based on the above findings it can be concluded that, combined treatment with atorvastatin and imipenem dampened the inflammatory response and reduced the bacterial load, thus seems to have promising therapeutic potential in sepsis-induced lung injury in mice.
Keywords: Atorvastatin; Imipenem; Lung injury; Sepsis;
Subcutaneous l-tyrosine elicits cutaneous analgesia in response to local skin pinprick in rats by Ching-Hsia Hung; Chong-Chi Chiu; Kuo-Sheng Liu; Yu-Wen Chen; Jhi-Joung Wang (457-462).
The purpose of the study was to estimate the ability of l-tyrosine to induce cutaneous analgesia and to investigate the interaction between l-tyrosine and the local anesthetic lidocaine. After subcutaneously injecting the rats with l-tyrosine and lidocaine in a dose-dependent manner, cutaneous analgesia (by blocking the cutaneous trunci muscle reflex-CTMR) was evaluated in response to the local pinprick. The drug–drug interaction was analyzed by using an isobolographic method. We showed that both l-tyrosine and lidocaine produced dose-dependent cutaneous analgesia. On the 50% effective dose (ED50) basis, the rank of drug potency was lidocaine (5.09 [4.88–5.38] μmol)>l-tyrosine (39.1 [36.5–41.8] μmol) (P<0.05). At the equipotent doses (ED25, ED50, and ED75), the duration of cutaneous analgesia caused by l-tyrosine lasted longer than that caused by lidocaine (P<0.01). Lidocaine co-administered with l-tyrosine exhibited an additive effect on infiltrative cutaneous analgesia. Our pre-clinical study demonstrated that l-tyrosine elicits the local/cutaneous analgesia, and the interaction between l-tyrosine and lidocaine is additive. l-tyrosine has a lower potency but much greater duration of cutaneous analgesia than lidocaine. Adding l-tyrosine to lidocaine preparations showed greater duration of cutaneous analgesia compared with lidocaine alone.
Keywords: L-tyrosine; Lidocaine; Cutaneous analgesia; Isobologram;
Propofol protects against opioid-induced hyperresponsiveness of airway smooth muscle in a horse model of target-controlled infusion anaesthesia by Luigino Calzetta; Alessio Soggiu; Paola Roncada; Luigi Bonizzi; Elena Pistocchini; Andrea Urbani; Barbara Rinaldi; Maria Gabriella Matera (463-471).
General anaesthesia in horses is associated with elevated mortality rate in subjects suffering of heaves. Target-controlled infusion (TCI) of sedative–hypnotic medications and opioids represents a total intravenous anaesthesia (TIVA) method validated in veterinary medicine. Since there are no data concerning the impact of these classes of drugs in inducing bronchial hyperresponsiveness (BHR) in horses, the aim of this study was to investigate the effect propofol and remifentanil on the contractile response of equine airway smooth muscle.The influence of propofol and remifentanil on the contractile response of equine isolated bronchi to electrical field stimulation (EFS) was assessed. The role of capsaicin-sensitive sensory nerves, inducible nitric oxide synthase (iNOS) and neurokinin 2 (NK2) receptor was also assessed. The interaction analysis was performed by Bliss Independence theory. Experiments were repeated in desensitized and passively sensitized airways.Remifentanil induced BHR in both non-sensitized and passively sensitized bronchi, (+56.33±8.01% and +99.10±14.52%, respectively; P<0.01 vs. control) and propofol significantly prevented this effect (P>0.05 vs. remifentanil). The inactivation of capsaicin-sensitive sensory nerves via desensitization and blocking NK2 receptor inhibited the BHR remifentanil-induced (P>0.05 vs. controls). The inhibition of iNOS reverted the protective effect of propofol on the BHR induced by remifentanil (non-sensitized: +47.11±7.70%; passively sensitized: +70.51±11.39%; P<0.05 vs. control). Propofol synergistically interacted (overall ≈40%) in preventing the remifentanil-induced BHR.Remifentanil induces BHR via stimulating capsaicin-sensitive sensory nerves that facilitate the cholinergic neurotransmission through the activation of NK2 receptor. The propofol/remifentanil combination may be safely administered in course of TCI–TIVA procedures also in heaves affected horses.
Keywords: Bronchial hyperresponsiveness; Equine isolated bronchi; Propofol; Remifentanil; Drug interaction; Veterinary anaesthesia;
Inhibition of the nitric oxide/cyclic guanosine monophosphate pathway limited the cardioprotective effect of post-conditioning in hearts with apical myocardial infarction by Francisco Correa; Mabel Buelna-Chontal; Victoria Chagoya; Gerardo García-Rivas; Rosa María Vigueras; José Pedraza-Chaverri; Wylly Ramsés García-Niño; Rogelio Hernández-Pando; Juan Carlos León-Contreras; Cecilia Zazueta (472-481).
Reperfusion damage involves opening of the mitochondrial permeability transition pore (mPTP) and loss of ATP synthesis. Several cardioprotective pathways are activated by ischemic or pharmacological post-conditioning (PC). The mechanisms that are activated by PC in no co-morbidity murine models include: activation of rescue kinases, oxidative stress reduction, glycolytic flux regulation and preservation of ATP synthesis. However, relatively scarce efforts have been made to define whether the efficacy of PC signaling is blunted by risk factors or systemic diseases associated with ischemic heart pathology. Experimental evidence has shown that the nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling is a main mechanism activated by PC in hearts without pathological history. In this work we evaluated the participation of the NO pathway, through downstream kinase activation and inhibition of mPTP in hearts with previous infarct.Myocardial infarction was induced with a single dose of isoproterenol (85 mg/kg i.p.) to male Wistar rats. After 24 h, the hearts were mounted into the Langendorff system and subjected to 30 min of ischemia and 60 min of reperfusion. PC consisted of 5 cycles of 30 s of reperfusion/30 s of ischemia, then the hearts were reperfused with or without inhibitors of the NO/cGMP pathway.PC activates the NO/cGMP pathway, as increased cGMP and NO levels were detected in isoproterenol-treated hearts. The cardioprotective effect of PC was abolished with both l-NAME (inhibitor of constitutive NO synthase) and ODQ (inhibitor of soluble guanylate cyclase), whereas the NO donor (DETA-NO) restored cardioprotection even in the presence of l-NAME or ODQ. We also found that mitochondrial structure and function was preserved in PC hearts.We conclude that PC exerts cardioprotection in hearts with previous infarct by maintaining mitochondrial structure and function through NO-dependent pathway.
Keywords: Post-conditioning; Isoproterenol; Reperfusion injury; cGMP;
Exenatide reduces TNF-α expression and improves hippocampal neuron numbers and memory in streptozotocin treated rats by Volkan Solmaz; Bilge Piri Çınar; Gürkan Yiğittürk; Türker Çavuşoğlu; Dilek Taşkıran; Oytun Erbaş (482-487).
Recent studies suggest a possible link between type 2 diabetes and Alzheimer's disease (AD). Glucogan-like peptide 1 (GLP-1) facilitates insulin release from pancreas under hyperglycemic conditions. In addition to its metabolic effects, GLP-1 and its long-lasting analogs, including exenatide can stimulate neurogenesis and improve cognition in rodent AD model. The aim of the present study was to investigate the effects of exenatide on hippocampal cellularity, cognitive performance and inflammation response in a rat model of AD. Fourteen rats were used to create AD model using intracerebroventricular (ICV) streptozotocin (STZ) infusion while 7 rats were administered 0.9% NaCl only (sham-operated group). Following stereotaxic surgery, STZ received rats were randomly distributed into two groups, and treated with either saline or exenatide 20 µgr/kg/day through intraperitoneally for two weeks. Then, cognitive performance (passive avoidance learning), brain tumor necrosis factor alpha (TNF-α) levels, choline acetyltransferase (ChAT) activity and hippocampal neuronal count were determined. While the brain TNF-α levels were significantly high in the saline-treated STZ group, exenatide treatment suppressed the increase in TNF-α levels. Saline-treated STZ group showed reduced ChAT activity compared to sham group. However, exenatide significantly preserved brain ChAT activity. The cognitive performance was also impaired in saline group while exenatide improved memory in rats. Moreover, exenatide treatment significantly prevented the decrease in hippocampal neurons. Overall, the results of the present study clearly indicated exenatide might have beneficial effects on impaired cognitive performance and hippocampal neuronal viability in AD by suppressing the inflammation response and increasing cholinergic activity.
Keywords: Alzheimer's disease; Exenatide; Tumor necrosing factor-alpha; Choline acetyltransferase; Streptozotocin;
Stabilization of Kv1.5 channel protein by the inotropic agent olprinone by Ryo Endo; Yasutaka Kurata; Tomomi Notsu; Peili Li; Kumi Morikawa; Takehito Kondo; Kazuyoshi Ogura; Junichiro Miake; Akio Yoshida; Yasuaki Shirayoshi; Haruaki Ninomiya; Katsumi Higaki; Masanari Kuwabara; Kazuhiro Yamamoto; Yoshimi Inagaki; Ichiro Hisatome (488-494).
Olprinone is an inotropic agent that inhibits phosphodiesterase (PDE) III and causes vasodilation. Olprinone has been shown to be less proarrhythmic and possibly affect expression of functional Kv1.5 channels that confer the ultra-rapid delayed-rectifier K+ channel current (I Kur) responsible for action potential repolarization. To reveal involvement of Kv1.5 channels in the less arrhythmic effect of olprinone, we examined effects of the agent on the stability of Kv1.5 channel proteins expressed in COS7 cells. Olprinone at 30–1000 nM increased the protein level of Kv1.5 channels in a concentration-dependent manner. Chase experiments showed that olprinone delayed degradation of Kv1.5 channels. Olprinone increased the immunofluorescent signal of Kv1.5 channels in the endoplasmic reticulum (ER) and Golgi apparatus as well as on the cell surface. Kv1.5-mediated membrane currents, measured as 4-aminopyridine-sensitive currents, were increased by olprinone without changes in their activation kinetics. A protein transporter inhibitor, colchicine, abolished the olprinone-induced increase of Kv.1.5-mediated currents. The action of olprinone was inhibited by 4-aminopyridine, and was not mimicked by the application of 8-Bromo-cAMP. Taken together, we conclude that olprinone stabilizes Kv1.5 proteins at the ER through an action as a chemical chaperone, and thereby increases the density of Kv1.5 channels on the cell membrane. The enhancement of Kv1.5 currents could underlie less arrhythmogenicity of olprinone.
Keywords: Olprinone; Kv1.5 channel; Chemical chaperone;
Condensed catechins and their potential health-benefits by Toshiro Matsui (495-502).
Condensed catechins are commonly present in fermented tea, and are produced by the oxidation of monomeric catechins. Due to their auto-oxidation, catechins have diverse structural features, including different binding modes and degrees of polymerization. Because of their structural complexity, their physiological functions and possible health-benefits have not yet been fully investigated. This review focuses on the physiological potentials of dimeric and trimeric catechins in the intestine (regulation of absorption across the intestinal membrane), blood vessels (vasorelaxation in vessel regulation), and muscle organs (promotion of glucose uptake resulting in an anti-diabetic effect). Furthermore, the roles of non-absorbable theaflavins (dimeric catechins), absorbable theasinensins (dimeric catechins), and absorbable procyanidins (dimeric and trimeric catechins) on target organs are discussed.
Keywords: Condensed catechins; Theaflavins; Theasinensins; Procyanidins;
Acute restraint stress increases carotid reactivity in type-I diabetic rats by enhancing Nox4/NADPH oxidase functionality by Josimar D. Moreira; Larissa Pernomian; Mayara S. Gomes; Laena Pernomian; Rafael P. Moreira; Alejandro F. do Prado; Carlos H.T.P. da Silva; Ana M. de Oliveira (503-516).
Hyperglycemia increases the generation of reactive oxygen species and affects systems that regulate the vascular tone including renin–angiotensin system. Stress could exacerbate intracellular oxidative stress during Diabetes upon the activation of angiotensin AT1/NADPH oxidase pathway, which contributes to the development of diabetic cardiovascular complications. For this study, type-I Diabetes was induced in Wistar rats by intraperitoneal injection of streptozotocin. 28 days after streptozotocin injection, the animals underwent to acute restraint stress for 3 h. Cumulative concentration–response curves for angiotensin II were obtained in carotid rings pre-treated or not with Nox or cyclooxygenase inhibitors. Nox1 or Nox4 expression and activity were assessed by Western blotting and lucigenin chemiluminescence, respectively. The role of Nox1 and Nox4 on reactive oxygen species generation was evaluated by flow cytometry and Amplex Red assays. Cyclooxygenases expression was assessed by real-time polymerase chain reaction. The contractile response evoked by angiotensin II was increased in diabetic rat carotid. Acute restraint stress increased this response in this vessel by mechanisms mediated by Nox4, whose local expression and activity in generating hydrogen peroxide are increased. The contractile hyperreactivity to angiotensin II in stressed diabetic rat carotid is also mediated by metabolites derived from cyclooxygenase-2, whose local expression is increased. Taken together, our findings suggest that acute restraint stress exacerbates the contractile hyperreactivity to angiotensin II in diabetic rat carotid by enhancing Nox4-driven generation of hydrogen peroxide, which evokes contractile tone by cyclooxygenases-dependent mechanisms. Finally, these findings highlight the harmful role played by acute stress in modulating diabetic vascular complications.Nox1/NADPH oxidase activity in carotid arteries from diabetic rats is enhanced; angiotensin II increases the generation of superoxide (O2 −) and hydrogen peroxide (H2O2), which contribute to angiotensin II-induced contraction by activating the synthesis of contractile metabolites from cyclooxygenases (COX) (A). Acute restraint stress enhances the activity of Nox4/NADPH oxidase during type-1 Diabetes; Nox4 generates high levels of H2O2, which modulates the production of COX metabolites (B). Dashed arrow: activity; continuous arrow: generation; FAD, flavin-adenine dinucleotide; SOD, superoxide dismutase; O2 − superoxide anion; H2O2, hydrogen peroxide; VSCM, vascular smooth muscle cell; AngII, angiotensin II; TXA2, thromboxane A2; PGH2, prostaglandin H2.Display Omitted
Keywords: Type-I Diabetes; Acute restraint stress; Reactive oxygen species; NADPH oxidase; Renin–angiotensin system;
4-Nerolidylcatechol analogues as promising anticancer agents by Alane Pereira Cortez; Renato Ivan de Ávila; Carla Rosane Mendanha da Cunha; Alexandre Pereira Santos; Ricardo Menegatti; Kênnia Rocha Rezende; Marize Campos Valadares (517-524).
4-Nerolidylcatechol (1) is an isolated compound from Pothomorphe umbellata L. (Piperaceae) with promising antitumor cells properties. However it presents lability under light and room temperatures. Many efforts have been directed towards discovering anticancer agents endowed with cytotoxic activities. Here, we evaluated cytotoxic effects of 4-NRC analogues (LQFMs 2–6) and the cell death pathways induced by these compounds in multidrug-resistant K562 cells. Compounds (2–6) exhibited cytotoxic activities in a concentration-dependent manner against leukaemic cells, specially the compounds (3) and (5). Additionally, compounds (1), (3) and (5) promoted marked alterations on the cell morphology, including nuclear changes as demonstrated by Hoescht 33342 staining. Moreover, these compounds promoted apoptosis induction in K562 cells by phosphatidylserine exposure, increase of sub-G1 cells and modulation of the caspases-3/7, -8 and -9 activation. In addition, the pancaspase inhibitor z-VAD-fmk partially reduced the apoptosis induced by the compounds (1) and (5)-induced, suggesting caspase-dependent and caspase-independent cell death pathways. Compounds (1) and (5) also modified the cell cycle progression by G0/G1 and S arrest, respectively. Furthermore, compounds (1), (3) and (5) promoted mitochondrial dysfunction associated to accumulation of cytosolic cytochrome c and modulated the NF-ĸB activation. In addition, unlike their analogues, 4-NRC (1) also promoted a significant cyclin D1 inhibition. Together, these data suggest that the mechanism of cell death of 4-NRC and its analogues (3) and (5) occurs by apoptosis through mitochondrial mechanisms. Considering that LQFMs are biocompatible synthetic analogues produced by molecular simplification of (1) without the chiral centre, which is associated with the instability found in compound (1), we suggest that these compounds are promising candidates for further pre-clinical studies.
Keywords: 4-Nerolidylcatechol analogues; Anticancer agents; Apoptosis;
The hypotensive effect of the nitric monoxide donor Oxacom at different routs of its administration to experimental animals by Alexander А. Тimoshin; Vladimir L. Lakomkin; Alexander А. Аbramov; Enno K. Ruuge; Valery I. Kapel’ko; Evgeny I. Chazov; Anatoly F. Vanin (525-532).
Earlier it has been found that the hypotensive drug Oxacom containing binuclear dinitrosyl iron complexes (B-DNIC) with glutathione can effectively decrease, as a nitric monooxide (NO) donor, the mean arterial pressure (МАР) in rats upon intravenous bolus injection in the form of an aqueous solution (Chazov et al., 2012). The aim of this study was to investigate the hypotensive effects of Oxacom administered to experimental rats by intravenous, intramuscular, subcutaneous, intraperitoneal, intragastric, rectal routes.MAP and heart rate (HR) were measured with the help of arterial catheters equipped with tensometric sensors. Oxacom was administered to rats at the dose of 2.0 μmole of B-DNIC/kg. The concentration of paramagnetic mononuclear protein-bound DNIC (М-DNIC) formed in the blood and tissues of various internal organs of the rat was determined by the EPR method. Upon subcutaneous, intramuscular or intraperitoneal administration of Oxacom, the maximum amplitude of the МАР decrease varies from 30% to 70%, respectively, in comparison with the corresponding parameter for the intravenously injected Oxacom. Another difference is the lack of the fast phase in the initial stage of the МАР decrease and the longer persistence of protein-bound M-DNIC formed in the circulating blood after intramuscular, subcutaneous or intraperitoneal administration of Oxacom. Thus, the NO donor Oxacom exerts pronounced hypotensive effects on rats not only upon intravenous, but also upon intramuscular, subcutaneous or intraperitoneal administration.
Keywords: Dinitrosyl iron complexes; Oxacom; Hypotension;
Broad-range TRP channel inhibitors (2-APB, flufenamic acid, SKF-96365) affect differently contraction of resistance and conduit femoral arteries of rat by Michal Bencze; Michal Behuliak; Anna Vavřínová; Josef Zicha (533-540).
Transient receptor potential (TRP) channels are proposed to contribute to membrane depolarization and Ca2+ influx into vascular smooth muscle (VSM) cells. Our aim was to study the effects of widely used broad-range TRP channel inhibitors – 2-aminoethoxydiphenyl borate (2-APB), flufenamic acid (FFA) and SKF-96365 – on the contraction of freshly isolated small and large arteries.Endothelium-denuded resistance (≈250 µm) and conduit (≈1000 µm) femoral arteries were isolated from adult Wistar rats and mounted in wire myograph. The effects of the above mentioned TRP channel inhibitors and voltage-dependent calcium channel inhibitor nifedipine were studied on arterial contractions induced by phenylephrine, U-46619 or K+. Phenylephrine-induced contractions were also studied in the absence of extracellular Na+. mRNA expression of particular canonical and melastatin TRP channel subunits in femoral vascular bed was determined.TRP channel inhibitors attenuated K+-induced contraction less than nifedipine. Phenylephrine-induced contraction was more influenced by 2-APB in resistance arteries, while FFA completely prevented U-46619-induced contraction in both sizes of arteries. The absence of extracellular Na+ prevented the inhibitory effects of 2-APB, but not those of FFA.The observed effects of broad-range TRP channel inhibitors, which were dependent on the size of the artery, confirmed the involvement of TRP channels in agonist-induced contractions. The inhibitory effects of 2-APB (but not those of FFA or SKF-96365) were dependent on the presence of extracellular Na+.
Keywords: Femoral artery; TRP channel; 2-APB; Flufenamic acid; SKF-96365; Vascular contraction;
Loganin protects against pancreatitis by inhibiting NF-κB activation by Myoung-Jin Kim; Gi-Sang Bae; Il-Joo Jo; Sun-Bok Choi; Dong-Goo Kim; Joon-Yeon Shin; Sung-Kon Lee; Min-Jun Kim; Soyoung Shin; Ho-Joon Song; Sung-Joo Park (541-550).
Acute pancreatitis (AP) is an inflammatory disease of the pancreas, which, in its most severe form, is associated with multi-organ failure and death. Loganin, a major iridoid glycoside obtained from Corni fructus, has been shown to have anti-inflammatory and anti-shock effects. However, the effects of loganin on AP have not been determined. Pre-treatment of loganin reduced pancreatic damage and AP-associated lung injury and attenuated the severity of AP, as evidenced by (1) a reduction in several biochemical parameters (pancreatic weight to body weight ratio, myeloperoxidase activity, and level of amylase) and (2) production of pro-inflammatory cytokines such as interleukin (IL)-1β and tumor necrosis factor (TNF)-α. However, post-treatment of loganin failed to improve pancreatic damage and biochemical parameters of AP, but could inhibit the AP-induced elevation of IL-1β and TNF-α significantly. In addition, cerulein-induced activation of nuclear factor (NF)-κB was inhibited in the pancreas by administration of loganin. In conclusion, these results suggest that loganin exhibits an anti-inflammatory effect in cases of AP and its pulmonary complications through inhibition of NF-κB activation.
Keywords: Acute pancreatitis; Loganin; Nuclear factor-κB; Proinflammatory cytokines;
A novel radioligand for the ATP-gated ion channel P2X7: [3H] JNJ-54232334 by Brian Lord; Michael K. Ameriks; Qi Wang; Lawrence Fourgeaud; Maarten Vliegen; Willy Verluyten; Pieter Haspeslagh; Nicholas I. Carruthers; Timothy W. Lovenberg; Pascal Bonaventure; Michael A. Letavic; Anindya Bhattacharya (551-559).
The ATP-gated ion channel P2X7 has emerged as a potential central nervous system (CNS) drug target based on the hypotheses that pro-inflammatory cytokines such as IL-1β that are released by microglia, may contribute to the etiology of various disorders of the CNS including depression. In this study, we identified two closely related P2X7 antagonists, JNJ-54232334 and JNJ-54140515, and then tritium labeled the former to produce a new radioligand for P2X7. JNJ-54232334 is a high affinity ligand for the rat P2X7 with a pKi of 9.3±0.1. In rat cortical membranes, [3H] JNJ-54232334 reached saturable binding with equilibrium dissociation (K d) constant of 4.9±1.3 nM. The compound displayed monophasic association and dissociation kinetics with fast on and off rates. In rat brain sections, specific binding of [3H] JNJ-54232334 was markedly improved compared to the previously described P2X7 radioligand, [3H] A-804598. In P2X7 knockout mouse brain sections, [3H] A-804598 bound to non-P2X7 binding sites in contrast to [3H] JNJ-54232334. In rat or wild type mouse brain sections [3H] JNJ-54232334 bound in a more homogenous and region independent manner. The ubiquitous expression of P2X7 receptors was confirmed with immunohistochemistry in rat brain sections. The partial displacement of [3H] A-804598 binding resulted in the underestimation of the level of ex vivo P2X7 occupancy for JNJ-54140515. Higher levels of P2X7 ex vivo occupancy were measured using [3H] JNJ-54232334 due to less non-specific binding. In summary, we describe [3H] JNJ-54232334 as a novel P2X7 radioligand, with improved properties over [3H] A-804598.
Keywords: P2X7; Radioligand binding; Depression; Autoradiography; Receptor occupancy; JNJ-54232334; JNJ-54140515;
PPARα regulates tumor progression, foe or friend? by Jiaming Gao; Shuping Yuan; Jianhua Jin; Juanjuan Shi; Yongzhong Hou (560-564).
PPARα belongs to the peroxisome-proliferator-activated receptors (PPARs) family that consists of PPARα, PPARδ, and PAPRγ. Activation of PPARα by ligands including fatty acids and their derivatives as well as some synthetic compounds regulates tumor progression in various tissues. Activated PPARα inhibits or promotes tumorigenesis depending on the specific tissues, but the molecular mechanism is still unclear. In this review, the recent progress of PPARα regulating tumorigenesis is discussed.
Keywords: PPARα; Ligands; Tumorigenesis;
miR-100 suppresses mTOR signaling in hypoxia-induced pulmonary hypertension in rats by Ai-ping Wang; Xiao-hui Li; Shao-xin Gong; Wen-qun Li; Chang-ping Hu; Zheng Zhang; Yuan-Jian Li (565-573).
Mammalian Target of Rapamycin (mTOR) is involved in the proliferation and survival of pulmonary artery smooth muscle cells (PASMCs) in human pulmonary hypertension (PH) and animal PH models, and miRNAs are reported to play a key role in modulation of the proliferation of PASMCs. The purposes of this study are to determine the functions of miR-100 and mTOR in cardiovascular remodeling of the hypoxic PH rats and to clarify the correlation between them. We established a rat model of hypoxic PH, which showed an increase in right ventricle systolic pressure, right ventricular and pulmonary vascular remodeling, accompanied by an up-regulation of mTOR and a down-regulation of miR-100. Next, we established an in vitro model of hypoxia-induced proliferation of PASMCs. Consistent with the in vivo findings, hypoxia induced proliferation of PASMCs, accompanied by a down-regulation of miR-100 and an up-regulation of mTOR; these phenomena were reversed by miR-100 mimics or the antagonist of mTOR. Finally, the dual-luciferase reporter gene assay was utilized to reveal the direct interaction between miR-100 and the 3 ′-UTR region of mTOR gene. Based on these observations, we conclude that miR-100 can modulate the proliferation of PASMCs in hypoxic PH rats through suppressing the mTOR expression.
Keywords: MiR-100; Pulmonary hypertension; Proliferation; Vascular remodeling; Pulmonary arterial smooth muscle cells; MTOR;
Cardioprotective role of tadalafil against cisplatin-induced cardiovascular damage in rats by Rasha M. Saleh; Walaa F. Awadin; Reham A. El-Shafei; Yousef Y. Elseady; Faheim E. Wehaish; Mohamed F. Elshal (574-581).
The present study investigated the possible cardioprotective effect of tadalafil (Tad) on cisplatin (CDDP)-induced cardiac and vascular damages in rats. A total number of seventy two healthy male albino rats initially weighting between 200 and 220 g were used and randomly divided into four groups,18 rats in each. The control group received no treatment; CDDP group received a single dose of CDDP (4 mg/kg) intraperitoneal (i.p.) per week for 4 weeks the duration of the experiment; Tad group received 0.4 mg/kg BW Tad i.p. daily and Tad +CDDP group received 0.4 mg/kg BW Tad i.p. +4 mg/kg BW CDDP i.p. The results showed that Tad was able to decrease blood pressure, heart rate, levels of serum cardiac troponin (cTn-I), malondialdehyde (MDA) and increased levels of reduced glutathione (GSH) and nitric oxide (NO) in the heart homogenate sample from CDDP treated rats. Semi-quantitative analysis showed that Tad was able to decrease the histopathological scores of cardiac muscular hyalinzation and fibrosis in three sacrifices in CDDP treated rats. CDDP treated rats showed significantly increased thickening in wall of aorta with an irregular luminal layer of endothelial cell linings in three sacrifices when it was compared to other groups. Moreover, immunohistochemical labeling of α- smooth muscle actin (α-SMA) in aorta revealed significant lower scores in Tad +CDDP group when they were compared to CDDP group. In conclusion, Tad alone did not induce any harmful effects on blood pressure, selective antioxidant, peroxidation markers or cardiac histology, in addition, Tad has a cardio-protective role against CDDP.
Keywords: Tadalafil; Cisplatin; Cardiac; Vascular damage; Rats;
Anti-inflammatory effect of dual nociceptin and opioid receptor agonist, BU08070, in experimental colitis in mice by Marta Zielińska; Tanila Ben Haddou; Gerta Cami-Kobeci; Maciej Sałaga; Agata Jarmuż; Milena Padysz; Radzisław Kordek; Mariana Spetea; Stephen M. Husbands; Jakub Fichna (582-590).
Endogenous opioid and nociceptin systems are widely distributed in the gastrointestinal tract where they seem to play a crucial role in maintaining the intestinal homeostasis. The aim of our study was to assess whether activation of nociceptin (NOP) and µ-opioid (MOP) receptors by a mixed NOP/MOP receptor agonist, BU08070, induces anti-inflammatory response in experimental colitis.The anti-inflammatory effect of BU08070 (1 mg/kg i.p.) was characterized in the mouse model of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis, based on the assessment of the macroscopic and microscopic total damage scores and determination of myeloperoxidase (MPO) activity and TNF-α level in the colon. The effect of BU08070 on cell viability and NF-κB was characterized in THP-1 Blue cell line. The antinociceptive activity of BU08070 was examined in mustard oil-induced mouse model of abdominal pain.A potent anti-inflammatory effect of BU08070 (1 mg/kg i.p.) was observed as indicated by decrease in macroscopic damage score (1.88±0.39 vs. 5.19±0.43 units in TNBS alone treated mice), MPO activity (2.29±0.37 vs. 9.64±2.55 units) and TNF-α level in the colon (35.85±2.45 vs. 49.79±3.81 pg/ml). The anti-inflammatory effect of BU08070 was reversed by selective NOP and MOP receptor antagonists. BU08070 produced concentration-dependent inhibition of TNF-α and LPS-induced NF-κB activation. BU08070 exerted antinociceptive action in mice with experimental colitis.In conclusion, BU08070 significantly reduced the severity of colitis in TNBS-treated mice compared with controls. These results suggest that BU08070 is a potential therapeutic agent for inflammatory bowel diseases therapy.
Keywords: Crohn's disease; Inflammatory bowel diseases; Mixed opioid agonists; Visceral pain;
Insulin sensitizing and cardioprotective effects of Esculetin and Telmisartan combination by attenuating Ang II mediated vascular reactivity and cardiac fibrosis by Almesh Kadakol; Anuradha Pandey; Santosh Kumar Goru; Vajir Malek; Anil Bhanudas Gaikwad (591-597).
The combination of the angiotensin receptor blockers (ARBs) with other synthetic and natural molecules has been reported to have better safety profile and therapeutic efficacy in prevention of diabetes and its associated complications than their monotherapy. Driven by the aforementioned facts, this study was conceived to evaluate the potential additive effect of combination of Telmisartan and Esculetin in prevention of insulin resistance and associated cardiac fibrosis. Recently, we have reported that Esculetin prevented cardiovascular dysfunction associated with insulin resistance (IR) and type 2 diabetes. Insulin resistance was developed by high fat diet (HFD) feeding to Wistar rats. Telmisartan and Esculetin were administered at 10 mg/kg/day and 50 mg/kg/day doses (P.O, 2 weeks), respectively either alone or in combination. Plasma biochemical analyses, vascular reactivity and immunohistochemical experiments were performed to assess the beneficial effect of Telmisartan, Esculetin and their combination on insulin resistance and associated cardiac fibrosis. The study results showed that, co-administered Telmisartan and Esculetin ameliorated the pathological features like metabolic perturbation, morphometric alterations, vascular hyper responsiveness, extracellular matrix accumulation and the expression of fibronectin and TGF-β more effectively than monotherapy in HFD fed rats. Hence, the study urges us to conclude that the solution to IR and associated cardiovascular dysfunction may lie in the Telmisartan and Esculetin combination therapy.
Keywords: Insulin resistance; Esculetin; Telmisartan; Cardiac fibrosis; Ang II; TGF-β;
Endogenous oestrogens do not regulate endothelial nitric oxide production in early postnatal rats by Svetlana I. Sofronova; Dina K. Gaynullina; Andrey A. Martyanov; Olga S. Tarasova (598-605).
Previously we showed that endothelium of 1-2-weeks old rats exerts an anticontractile effect due to spontaneous NO production which correlates with a higher eNOS expression level compared to adult rats. Oestrogens are powerful regulators of eNOS expression and activity in arterial endothelium. This study tested the hypothesis that anticontractile influence of endothelium in young rats is regulated by endogenous oestrogens. Wistar rats were daily treated with ICI 182,780 or letrozole (oestrogen receptor antagonist and aromatase inhibitor, respectively; s.c., 1 mg/kg/day) from the second postnatal day, control pups received vehicle injections. At the age of 10–12-days we studied contraction of saphenous arteries using wire myography. ELISA and qPCR were used to evaluate blood sex steroids levels and mRNA expression in arterial tissue, respectively. Ten-12 days old male rats compared to adult male rats demonstrated 78% higher serum 17β-oestradiol concentration and several-fold increase in mRNA contents of oestrogen receptors (ERα and GPER1). However, treatments with ICI 182,780 or letrozole did not affect arterial sensitivity to methoxamine (α 1-adrenoceptor agonist) in 10–12-days old males. The blockade of NO-synthase with L-NNA caused tonic contraction and potentiated the response to methoxamine, these effects were similar in control and both treated groups. The sensitivity of endothelium-denuded saphenous arteries to NO-donor DEA/NO did not differ between control and treated groups as well. In addition, treatments with ICI 182,780 or letrozole did not change eNOS expression level in arterial tissue. Our results suggest that endogenous oestrogens do not regulate anticontractile effect of NO during early postnatal development in rats.
Keywords: Endothelium; Estrogen; ICI 182,780; Letrozole; Nitric oxide; Rat;