European Journal of Pharmacology (v.784, #C)
Editorial Board (ii).
A novel substituted aminoquinoline selectively targets voltage-sensitive sodium channel isoforms and NMDA receptor subtypes and alleviates chronic inflammatory and neuropathic pain by Boris Tabakoff; Wenhua Ren; Lauren Vanderlinden; Lawrence D. Snell; Christopher J. Matheson; Ze-Jun Wang; Rock Levinson; C. Thetford Smothers; John J. Woodward; Yumiko Honse; David Lovinger; Anthony M. Rush; William A. Sather; Daniel L. Gustafson; Paula L. Hoffman (1-14).
Recent understanding of the systems that mediate complex disease states, has generated a search for molecules that simultaneously modulate more than one component of a pathologic pathway. Chronic pain syndromes are etiologically connected to functional changes (sensitization) in both peripheral sensory neurons and in the central nervous system (CNS). These functional changes involve modifications of a significant number of components of signal generating, signal transducing and signal propagating pathways. Our analysis of disease-related changes which take place in sensory neurons during sensitization led to the design of a molecule that would simultaneously inhibit peripheral NMDA receptors and voltage sensitive sodium channels. In the current report, we detail the selectivity of N,N-(diphenyl)-4-ureido-5,7-dichloro-2-carboxy-quinoline (DCUKA) for action at NMDA receptors composed of different subunit combinations and voltage sensitive sodium channels having different α subunits. We show that DCUKA is restricted to the periphery after oral administration, and that circulating blood levels are compatible with its necessary concentrations for effects at the peripheral cognate receptors/channels that were assayed in vitro. Our results demonstrate that DCUKA, at concentrations circulating in the blood after oral administration, can modulate systems which are upregulated during peripheral sensitization, and are important for generating and conducting pain information to the CNS. Furthermore, we demonstrate that DCUKA ameliorates the hyperalgesia of chronic pain without affecting normal pain responses in neuropathic and inflammation-induced chronic pain models.
Keywords: Chronic pain; NMDA; GluN2B; Nav1.8; Nav1.7; Substituted aminoquinoline;
Calcilytics enhance sildenafil-induced antiproliferation in idiopathic pulmonary arterial hypertension by Aya Yamamura; Satomi Yagi; Naoki Ohara; Kikuo Tsukamoto (15-21).
Idiopathic pulmonary arterial hypertension (IPAH) is a progressive and fatal disease of the pulmonary artery resulting from currently unidentified etiology. IPAH is pathologically characterized as sustained vasoconstriction and vascular remodeling of the pulmonary artery. Phosphodiesterase type 5 (PDE5) inhibitors have been clinically used in the treatment of IPAH. Recently, we have shown that Ca2+-sensing receptor (CaSR) antagonists, or calcilytics, inhibit excessive cell proliferation of pulmonary arterial smooth muscle cells (PASMCs) from IPAH patients. In this study, the additive or synergistic effect of calcilytics on antiproliferation following PDE5 inhibition was examined in IPAH-PASMCs by MTT assay. Treatment with sildenafil blocked the excessive cell proliferation of IPAH-PASMCs in a concentration-dependent manner with an IC50 value of 16.9 μM. However, sildenafil (0.03–100 μM) did not affect the cell growth of PASMCs from normal subjects and patients with chronic thromboembolic pulmonary hypertension (CTEPH). Co-treatment with 0.3 μM NPS2143, a calcilytic, additively enhanced the antiproliferative effect induced by sildenafil (3 or 30 μM) in IPAH-PASMCs. Additionally, the inhibitory effect of calcilytics, NPS2143 or Calhex 231 (1 or 10 μM), on excessive cell proliferation of IPAH-PASMCs was synergistic increased in the presence of 1 μM sildenafil. Similar results were obtained by BrdU incorporation assay. These findings reveal that calcilytics additively/synergistically enhance the antiproliferative activity mediated by PDE5 inhibition, suggesting that a combination therapy of a PDE5 inhibitor with a calcilytic may be useful as a novel therapeutic approach for IPAH.
Keywords: Pulmonary hypertension; Calcium-sensing receptor; Calcilytic; Phosphodiesterase 5 inhibitor; NPS2143; Sildenafil;
Changes in interconnected pathways implicating microRNAs are associated with the activity of apocynin in attenuating myocardial fibrogenesis by Qinbo Yang; Jingang Cui; Peiwei Wang; Xiaoye Du; Wenjian Wang; Teng Zhang; Yu Chen (22-32).
Myocardial fibrosis is the endpoint pathology common to many cardiovascular disorders. We have previously shown that apocynin (APO), a naturally occurring NADPH oxidase inhibitor, significantly prevents the development of isoproterenol (ISO)-induced myocardial injury and fibrogenesis. The current study investigated the changes in microRNAs (miRNAs) and their potential implication in the cardioprotective effects of APO. Integrative analyses of whole-genome miRNA and gene expression profiles were first performed, revealing that altered expression of miRNAs likely contributed to dysregulated expression of genes associated with multiple interconnected fibrogenic signaling pathways. Importantly, APO treatment exhibited a broad impact on these signaling pathways, which could in part be mediated through miRNA-mediated gene expression regulation. The expression of differentially expressed miRNAs was further validated by real-time PCR analyses. Consistent with the data from miRNA array, compared to that from vehicle-treated normal controls, significantly decreased expression of miR-10b, miR-29c*, miR-30c-1*, miR-30e*, miR-148b, miR-181d, miR-218 and miR-3107* was observed in ISO-challenged vehicle-treated mouse hearts. In contrast, significantly increased expression of these miRNAs was observed in ISO-challenged APO-treated hearts compared to that from ISO-challenged vehicle-treated mice. Moreover, increased expression of miR-21 was observed as a result of ISO administration, which was significantly reduced by APO treatment. Altered protein levels of Col1, TIMP1, Rac2 and gp91phox were also validated. Lastly, APO treatment was shown to attenuate pre-established myocardial fibrosis induced by ISO. The results therefore demonstrated for the first time that complex changes in miRNA-mRNA interactome network are associated with the protective effects of APO against ISO-induced myocardial injury and fibrogenesis.
Keywords: Apocynin; Oxidative stress; Myocardial fibrosis; Gene expression; MicroRNA;
Enhancement of contraction and L-type Ca2+ current by murrayafoline-A via protein kinase C in rat ventricular myocytes by Bojjibabu Chidipi; Min-Jeong Son; Joon-Chul Kim; Jeong Hyun Lee; Tran Quoc Toan; Nguyen Manh Cuong; Byung Ho Lee; Sun-Hee Woo (33-41).
We previously reported that murrayafoline-A (1-methoxy-3-methyl-9H-carbazole, Mu-A) increases the contractility of ventricular myocytes, in part, via enhancing Ca2+ influx through L-type Ca2+ channels, and that it increases the Ca2+ transients by activation of protein kinase C (PKC). In the present study, we further examined the cellular mechanisms for the enhancement of contractility and L-type Ca2+ current (ICa,L) by Mu-A. Cell shortening and ICa,L were measured in rat ventricular myocytes using a video edge detection method and perforated patch-clamp technique, respectively. We found that the positive inotropic effect of Mu-A was not affected by pre-exposure to the β-adrenoceptor antagonist propranolol, the protein kinase A (PKA) inhibitors KT5720 or H-89, or the phospholipase C inhibitor U73122. Interestingly, the Mu-A-mediated increases in cell shortening and in the rate of contraction were completely suppressed by pre-treatment with the PKC inhibitor GF109203X. The stimulatory effect of Mu-A on ICa,L was not altered by inhibition of PKA (KT5720), G-protein coupled receptors (suramin), or α1-adrenoceptor (prazosin). However, pre-exposure to the PKC inhibitor, GF109203X or chelerythrine, abolished the Mu-A-induced increase in ICa,L. Pre-exposure to the Ca2+-calmodulin-dependent protein kinase II (CaMKII) inhibitor KN93 slightly reduced the stimulatory effects on contraction and ICa,L by Mu-A. Phosphorylation of PKC was enhanced by Mu-A in ventricular myocytes. These data suggest that Mu-A increases contraction and ICa,L via PKC in rat ventricular myocytes, and that the PKC-mediated responses in the presence of Mu-A may be partly mediated by CaMKII.
Keywords: Murrayafoline-A; Positive inotropy; L-type Ca2+ current; PKC; Ventricular myocytes;
Glutamate in peripheral organs: Biology and pharmacology by Jie Du; Xiao-Hui Li; Yuan-Jian Li (42-48).
Glutamate is a versatile molecule existing in both the central nervous system and peripheral organs. Previous studies have mainly focussed on the biological effect of glutamate in the brain. Recently, abundant evidence has demonstrated that glutamate also participates in the regulation of physiopathological functions in peripheral tissues, including the lung, kidney, liver, heart, stomach and immune system, where the glutamate/glutamate receptor/glutamate transporter system plays an important role in the pathogenesis of certain diseases, such as myocardial ischaemia/reperfusion injury and acute gastric mucosa injury. All these findings provide new insight into the biology and pharmacology of glutamate and suggest a potential therapeutic role of glutamate in non-neurological diseases.
Keywords: Glutamate; Glutamate receptor; Glutamate transporter; Peripheral tissues; N-methyl-D-aspartate receptor (NMDA receptor);
A comparison of the delayed outward potassium current between the nucleus ambiguus and hippocampus: sensitivity to paeonol by Chin-Tsang Yang; Yuk-Man Leung; Sheng-Feng Hsu; Iona MacDonald; Mei-Ling Wang; Jaung-Geng Lin; Shih-Ya Hung; Yi-Hung Chen (49-60).
Whole-cell patch-clamp recordings investigated the electrophysiological effects of 2′-hydroxy-4′-methoxyacetophenone (paeonol), one of the major components of Moutan Cortex, in hippocampal CA1 neurons and nucleus ambiguus (NA) neurons from neonatal rats as well as in lung epithelial H1355 cells expressing Kv2.1 or Kv1.2. Extracellular application of paeonol at 100 μM did not significantly affect the spontaneous action potential frequency, whereas paeonol at 300 μM increased the frequency of spontaneous action potentials in hippocampal CA1 neurons. Paeonol (300 μM) significantly decreased the tetraethylammonium-sensitive outward current in hippocampal CA1 neurons, but had no effect upon the fast-inactivating potassium current (IA). Extracellular application of paeonol at 300 μM did not affect action potentials or the delayed outward currents in NA neurons. Paeonol (100 μM) reduced the Kv2.1 current in H1355 cells, but not the Kv1.2 current. The inhibitor of Kv2, guangxitoxin-1E, reduced the delayed outward potassium currents in hippocampal neurons, but had only minimal effects in NA neurons. We demonstrated that paeonol decreased the delayed outward current and increased excitability in hippocampal CA1 neurons, whereas these effects were not observed in NA neurons. These effects may be associated with the inhibitory effects on Kv2.1 currents.
Keywords: Paeonol; Hippocampal neuron; Potassium current; Action potentials;
Impaired diffuse noxious inhibitory controls in specific alternation of rhythm in temperature-stressed rats by Yasuo Itomi; Yasuhiro Tsukimi; Toru Kawamura (61-68).
Fibromyalgia is characterized by chronic widespread musculoskeletal pain. A hypofunction in descending pain inhibitory systems is considered to be involved in the chronic pain of fibromyalgia. We examined functional changes in descending pain inhibitory systems in rats with specific alternation of rhythm in temperature (SART) stress, by measuring the strength of diffuse noxious inhibitory controls (DNIC). Hindpaw withdrawal thresholds to mechanical von Frey filament or fiber-specific electrical stimuli by the Neurometer system were used to measure the pain response. To induce DNIC, capsaicin was injected into the intraplantar of the forepaw. SART-stressed rats were established by exposure to repeated cold stress for 4 days. In the control rats, heterotopic intraplantar capsaicin injection increased withdrawal threshold, indicative of analgesia by DNIC. The strength of DNIC was reduced by naloxone (μ-opioid receptor antagonist, intraperitoneally and intracerebroventricularly), yohimbine (α2-adrenoceptor antagonist, intrathecally), and WAY-100635 (5-HT1A receptor antagonist, intrathecally) in the von Frey test. In SART-stressed rats, capsaicin injection did not increase withdrawal threshold in the von Frey test, indicating deficits in DNIC. In the Neurometer test, deficient DNIC in SART-stressed rats were observed only for Aδ- and C-fibers, but not Aβ-fibers stimulation. Analgesic effect of intracerebroventricular morphine was markedly reduced in SART-stressed rats compared with the control rats. Taken together, in SART-stressed rats, capsaicin-induced DNIC were deficient, and a hypofunction of opioid-mediated central pain modulation system may cause the DNIC deficit.
Keywords: Diffuse noxious inhibitory controls; Descending pain inhibitory systems; Fibromyalgia; Specific alteration of rhythm in temperature;
Aromatic malononitriles stimulate the resistance of insulin-producing beta-cells to oxidants and inflammatory cytokines by Kyril Turpaev; Nils Welsh (69-80).
We presently report that treatment with tyrphostin AG-126 (2-(3-hydroxy-4-nitrobenzylidene)malononitrile) and ten other aromatic malononitrile compounds (AMN) improves the resistance of insulin-producing βTC6, RIN-5AH, and MIN6 cells to oxidative stress and pro-inflammatory cytokines. On the molecular level AMN compounds promote nuclear accumulation of the Nrf2 transcription factor and expression of the cytoprotective genes heme ogygenase 1 (HO-1) and NAD(P)H/quinone oxidoreductase 1 (NQO1), inhibit cytokine-dependent inducible nitric oxide synthase (iNOS) induction, suppress intracellular production of reactive oxygen species in βTC6 and counteract to impairments of glucose-stimulated insulin secretion induced by pro-inflammatory cytokines in MIN6 cells. Nrf2 up-regulation and HO-1 induction by AG-126 are attenuated at the presence of siRNA against Nrf2 and brusatol, an inhibitor of the Nrf2 signaling pathway. Our present results indicate that in respect of inhibition of IL-1β-dependent iNOS induction, βTC6 cells are more sensitive to EMK 1071 (2-((5-methylthiophen-2-yl)methylene)malononitrile) and EMK 31 (2-(4-hydroxy-3-methoxybenzylidene)malononitrile) as compared to other analyzed AMN compounds. We suggest that the ability of AMN compounds to inhibit iNOS induction and other cytokine-induced transcriptional events might be a tool to achieve improved β-cell survival and functionality.
Keywords: β-cells; Oxidative stress; Aromatic malononitriles; Heme oxygenase 1; iNOS; Nrf2;
Comparison of kinetic and pharmacological profiles of recombinant α1γ2L and α1β2γ2L GABAA receptors – A clue to the role of intersubunit interactions by Marek Brodzki; Radoslaw Rutkowski; Magdalena Jatczak; Magdalena Kisiel; Marta M. Czyzewska; Jerzy W. Mozrzymas (81-89).
The fastest inhibitory mechanism in the CNS is mediated by ionotropic GABAA receptors and it is known that subunit composition critically determines their properties. While a typical GABAA receptor consists of two α, two β and one γ/δ subunit, there are some exceptions, e.g. αβ receptors. Functional α1γ2 GABAA receptors can be expressed in recombinant model (Verdoorn et al., 1990) and although their role remains unknown, it seems appealing to extend their characterization to further explore the structure-function relationship of GABAA receptors. Intriguingly, this receptor is lacking canonical GABA binding sites but it can be activated by GABA and dose-response relationships for α1β2γ2L and α1γ2L receptors overlap. Deactivation kinetics was similar for both receptors but the percentage of the fast component was smaller in the case of α1γ2L receptors and, consequently, the mean deactivation time constant was slower. The rate and extent of macroscopic desensitization were smaller in the case of α1γ2L receptors but they showed slower recovery. Both receptor types had a similar proton sensitivity showing only subtle but significant differences in pH effects on deactivation. Flurazepam exerted a similar effect on both receptors but the rapid deactivation components were differently affected and an opposite effect was observed on desensitization extent. Rebound currents evoked by pentobarbital were undistinguishable for both receptor types. Taking altogether, although some significant differences were found, α1β2γ2L and α1γ2L receptors showed unforeseen similarity. We propose that functioning of GABAA receptors might rely on subunit-subunit cooperative interactions to a larger extent than believed so far.
Keywords: GABAA receptor; Kinetics; Pharmacology; Subunit stoichiometry; Intersubunit interactions;
Pyr3, a TRPC3 channel blocker, potentiates dexamethasone sensitivity and apoptosis in acute lymphoblastic leukemia cells by disturbing Ca2+ signaling, mitochondrial membrane potential changes and reactive oxygen species production by Souleymane Abdoul-Azize; Catherine Buquet; Jean-Pierre Vannier; Isabelle Dubus (90-98).
Dexamethasone (Dex) is used as a chemotherapeutic drug in the treatment of acute lymphoblastic leukemia (ALL) because of its capacity to induce apoptosis. However, some ALL patients acquire resistance to glucocorticoids (GC). Thus, it is important to explore new agents to overcome GC resistance. The aim of the present work was to assess the ability of Pyr3, a selective inhibitor of transient receptor potential canonical 3 (TRPC3), to sensitize human ALL cells to Dex. We show here, for the first time, that Pyr3 enhances Dex sensitivity through the distraction of Dex-mediated Ca2+ signaling in ALL cells (in vitro) and primary blasts (ex vivo) associated with mitochondrial-mediated reactive oxygen species production in ALL cells. Pyr3 alone induced Ca2+ signaling via only endoplasmic reticulum-released Ca2+ and exerted inhibitory effect on store-operated Ca2+ entry in dose-dependent manner in ALL cell lines. Pre-incubation of cells with Pyr3 significantly curtailed the thapsigargin- and Dex-evoked Ca2+ signaling in ALL cell lines. Pyr3 synergistically potentiated Dex lethality, as shown by the induction of cell mortality, G2/M cell cycle arrest and apoptosis in ALL cell lines. Moreover, Pyr3 disrupted Dex-mediated Ca2+ signaling and increased the sensitivity of Dex-induced cell death in primary blasts from ALL patients. Additional analysis showed that co-treatment with Dex and Pyr3 results in mitochondrial membrane potential depolarization and reactive oxygen species production in ALL cells. Together, Pyr3 exhibited potential therapeutic benefit in combination with Dex to inverse glucocorticoid resistance in human ALL and probably in other lymphoid malignancies.
Keywords: Acute lymphoblastic leukemia; Dexamethasone; Calcium signaling; Pyr3; Apoptosis, Reactive oxygen species;
The antioxidant protein PARK7 plays an important role in cell resistance to Cisplatin-induced apoptosis in case of clear cell renal cell carcinoma by Rachana Trivedi; Gry H. Dihazi; Marwa Eltoweissy; Durga P. Mishra; Gerhard A. Mueller; Hassan Dihazi (99-110).
Clear cell renal cell carcinoma (ccRCC) is the most malignant tumor in the adult kidney. Many factors are responsible for the development and progression of this tumor. Increased reactive oxygen species accumulation and altered redox status have been observed in cancer cells and this biochemical property of cancer cells can be exploited for therapeutic benefits. In earlier work we identified and characterize Protein DJ-1 (PARK7) as an oxidative stress squevenger in renal cells exposed to oxidative stress. To investigate whether the PARK7 or other oxidative stress proteins play a role in the renal cell carcinoma and its sensitivity or resistance to cytostatic drug treatment, differential proteomics analysis was performed with a cell model for clear cell renal carcinoma (Caki-2 and A498). Caki-2 cells were treated with cisplatin and differentially expressed proteins were investigated. The cisplatin treatment resulted in an increase in reactive oxygen species accumulation and ultimately apoptosis of Caki-2 and A498 cells. In parallel, the apoptotic effect was accompanied by a significant downregulation of antioxidant proteins especially PARK7. Knockdown of PARK7 using siRNA and overexpression using plasmid highlights the role of PARK7 as a key player in renal cell carcinoma response to cisplatin induced apoptosis. Overexpression of PARK7 resulted in significant decrease in apoptosis, whereas knockdown of the protein was accompanied by an increase in apoptosis in Caki-2 and A498 cells treated with cisplatin.These results highlights for the first time the important role of PARK7 in cisplatin induced apoptosis in clear renal cell carcinoma cells.
Keywords: Renal cell carcinoma; Caki-2; Cisplatin; PARK7; Apoptosis; Reactive oxygen species;
Adjuvant indoleamine 2,3-dioxygenase enzyme inhibition for comprehensive management of epilepsy and comorbid depression by Tanveer Singh; Rajesh Kumar Goel (111-120).
Epilepsy is one of the major neurological disorders frequently associated with psychiatric disorders such as depression. Alteration of tryptophan metabolism towards kynurenine pathway may be one of the plausible reasons for association of depression in epilepsy. Hence, this study was envisaged to evaluate the dose dependent inhibition of indoleamine 2,3-dioxygenase (IDO) enzyme (responsible for shifting tryptophan metabolism) employing minocycline with valproic acid for comprehensive management of epilepsy and comorbid depression. Kindling was induced in male swiss albino mice by administration of pentylenetetrazole subconvulsive dose (35 mg/kg, i.p.) at an interval of 48±2 h. Kindled animals were treated with saline, valproate (300 mg/kg/day i.p.), valproate in combination with different doses of minocycline (10 mg/kg; 20 mg/kg; 40 mg/kg)/day i.p. and minocycline per se (40 mg/kg/day i.p.) for 15 days. Except naïve, all the groups were challenged with pentylenetetrazole (35 mg/kg i.p.) on day 5, 10, and 15 to evaluate the seizure severity score. Depression was evaluated in all experimental groups using tail suspension and forced swim test on days 1, 5, 10 and 15, 2 h after pentylenetetrazole challenge. Results suggested that saline treated kindled animals were significantly associated with depression. Chronic valproate treatment significantly reduced seizure severity score but unable to ameliorate the associated depression. Minocycline supplementation with valproic acid dose dependently ameliorated depression associated with epilepsy. Neurochemical and biochemical findings also supported the behavioural findings of the study. Thus, our results suggested that supplementation of IDO enzyme inhibitors with valproic acid could be explored further for comprehensive management of epilepsy and associated depression.Display Omitted
Keywords: Corticosterone; Depression; Epilepsy; Indoleamine 2,3-dioxygenase; Minocycline;
Loading of Gemcitabine on chitosan magnetic nanoparticles increases the anti-cancer efficacy of the drug by Maryam Parsian; Gozde Unsoy; Pelin Mutlu; Serap Yalcin; Aysen Tezcaner; Ufuk Gunduz (121-128).
Targeted delivery of anti-cancer drugs increase the efficacy, while decreasing adverse effects. Among various delivery systems, chitosan coated iron oxide nanoparticles (CsMNPs) gained attention with their biocompatibility, biodegradability, low toxicity and targetability under magnetic field. This study aimed to increase the cellular uptake and efficacy of Gemcitabine.CsMNPs were synthesized by in situ co-precipitation and Gemcitabine was loaded onto the nanoparticles. Nanoparticle characterization was performed by TEM, FTIR, XPS, and zeta potential. Gemcitabine release and stability was analyzed. The cellular uptake was shown. Cytotoxicity of free-Gemcitabine and Gem-CsMNPs were examined on SKBR and MCF-7 breast cancer cells by XTT assay.Gemcitabine loading was optimized as 30 µM by spectrophotometric analyses. Drug release was highest (65%) at pH 4.2, while it was 8% at pH 7.2. This is a desired release characteristic since pH of tumor-tissue and endosomes are acidic, while the blood-stream and healthy-tissues are neutral. Peaks reflecting the presence of Gemcitabine were observed in FTIR and XPS. At neutral pH, zeta potential increased after Gemcitabine loading. TEM images displayed, Gem-CsMNPs were 4 nm with uniform size-distribution and have spherical shape. The cellular uptake and targetability of CsMNPs was studied on MCF-7 breast cancer cell lines. IC50 value of Gem-CsMNPs was 1.4 fold and 2.6 fold lower than free-Gem on SKBR-3 and MCF-7 cell lines respectively, indicating the increased efficacy of Gemcitabine when loaded onto nanoparticles.Targetability by magnetic field, stability, size distribution, cellular uptake and toxicity characteristics of CsMNPs in this study provides a useful targeted delivery system for Gemcitabine in cancer therapy.Display Omitted
Keywords: Chitosan; Magnetic nanoparticles; Gemcitabine; Targeted drug delivery; Breast cancer;
Role of JAK-STAT pathway in reducing cardiomyocytes hypoxia/reoxygenation injury induced by S1P postconditioning by Yuqing Wang; Dongfei Wang; Lizhi Zhang; Fangyu Ye; Mengmeng Li; Ke Wen (129-136).
This experiment was designed to explore the protection of sphingosine1-phosphate (S1P) postconditioning on rat myocardial cells injured by hypoxia/reoxygenation acting via the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signal pathway. The data showed that S1P could significantly increase cell viability, lower the rate of apoptosis, decrease the content of lactate dehydrogenase (LDH) and caspase3 activity in the culture medium, increase the activity of total superoxide dismutase (T-SOD) and manganese superoxide dismutase (Mn-SOD), reduce the loss of mitochondrial membrane potential and the fluorescence intensity of intracellular calcium, as well as increase the phosphorylation of JAK2 and STAT3 in comparison with the H/R group. When the JAK inhibitor AG490 or the STAT inhibitor stattic were added, the effects of S1P were inhibited. Our date shows that S1P protects H9c2 cells from hypoxia/reoxygenation injury and that the protection by S1P was inhibited by AG490 and stattic. Therefore S1P protects H9c2 cells against hypoxia/reoxygenation injury via the JAK-STAT pathway.Our study found that SIP could significantly increase cell viability and the activity of SOD reduce loss of mitochondrial membrane potential, decrease the content of LDH and caspase3 activity, lower the rate of apoptosis, reduce the concentration of intracellular calcium, and increase the phosphorylation of JAK2 and STAT3. When the JAK inhibitor AG490 or the STAT inhibitor static were added, the effects of SIP were inhibited.Display Omitted
Keywords: AG490 (PubChem CID: 5328779); DMSO (PubChem CID: 679); FITC (PubChem CID: 18730); Fluo-3 AM (PubChem CID: 104978); JC-1 (PubChem CID: 5492929); methyl thiazolyl tetrazolium (PubChem CID: 64965); sphingosine-1-phosphate (PubChem CID: 5283560); stattic (PubChem CID: 2779853); H9c2; S1P; JAK-STAT pathway; AG490; Stattic;
Pimecrolimus increases the expression of interferon-inducible genes that modulate human coronary artery cells proliferation by Janine Hussner; Juliane Sünwoldt; Isabell Seibert; Daniel G. Gliesche; Henriette E. Meyer zu Schwabedissen (137-146).
The pharmacodynamics of the loaded compounds defines clinical failure or success of a drug-eluting device. Various limus derivatives have entered clinics due to the observed positive outcome after stent implantation, which is explained by their antiproliferative activity resulting from inhibition of the cytosolic immunophilin FK506-binding protein 12. Although pimecrolimus also binds to this protein, pimecrolimus-eluting stents failed in clinics. However, despite its impact on T lymphocytes little is known about the pharmacodynamics of pimecrolimus in cultured human coronary artery cells. We were able to show that pimecrolimus exerts antiproliferative activity in human smooth muscle and endothelial cells. Furthermore in those cells pimecrolimus induced transcription of interferon-inducible genes which in part are known to modulate cell proliferation. Modulation of gene expression may be part of an interaction between calcineurin, the downstream target of the pimecrolimus/FK506-binding protein 12-complex, and the toll-like receptor 4. In accordance are our findings showing that silencing of toll-like receptor 4 by siRNA in A549 a lung carcinoma cell line reduced the activation of interferon-inducible genes upon pimecrolimus treatment in those cells. Based on our findings we hypothesize that calcineurin inhibition may induce the toll-like receptor 4 mediated activation of type I interferon signaling finally inducing the observed effect in endothelial and smooth muscle cells. The crosstalk of interferon and toll-like receptor signaling may be a molecular mechanism that contributed to the failure of pimecrolimus-eluting stents in humans.
Keywords: Pimecrolimus; Interferon-β; Calcineurin; Toll-like receptor 4;
Rapamycin reduces motivated responding for cocaine and alters GluA1 expression in the ventral but not dorsal striatum by Morgan H. James; Rikki K. Quinn; Lin Kooi Ong; Emily M. Levi; Doug W. Smith; Phillip W. Dickson; Christopher V. Dayas (147-154).
The mechanistic target of rapamycin complex 1 (mTORC1) regulates synaptic protein synthesis and therefore synaptic function and plasticity. A role for mTORC1 has recently been demonstrated for addiction-related behaviors. For example, central or intra-accumbal injections of the mTORC1 inhibitor rapamycin attenuates several indices of cocaine-seeking including progressive ratio (PR) responding and reinstatement. These behavioral effects are associated with decreased mTORC1 activity and synaptic protein translation in the nucleus accumbens (NAC) and point to a possible therapeutic role for rapamycin in the treatment of addiction. Currently, it is unclear whether similar behavioral and biochemical effects can be achieved by administering rapamycin systemically, which represents a more clinically-appropriate route of administration. Here, we assessed the effects of repeated, systemic administration of rapamycin (10 mg/kg, i.p.) on PR responding for cocaine. We also assessed whether systemic rapamycin was associated with changes in measures of mTORC1 activity and GluA1 expression in the ventral and dorsal striatum. We report that systemic rapamycin treatment reduced PR breakpoints to levels comparable to intra-NAC rapamycin. Systemic rapamycin treatment also reduced phosphorylated p70S6K and GluA1 AMPARs within the NAC but not dorsal striatum. Thus, systemic administration of rapamycin is as effective at reducing drug seeking behavior and measures of mTORC1 activity compared to direct accumbal application and may therefore represent a possible therapeutic option in the treatment of addiction. Possible caveats of this treatment approach are discussed.
Keywords: Cocaine; Striatum; mTOR; Nucleus accumbens; Rapamycin; Progressive ratio;
Furosemide modifies heart hypertrophy and glycosaminoglycan myocardium content in a rat model of neurogenic hypertension by Chryssa Pourzitaki; Georgia Tsaousi; Maria Eleni Manthou; Georgios Karakiulakis; Dimitrios Kouvelas; Eleni Papakonstantinou (155-163).
Hypertension is a major risk factor for atherogenesis and heart hypertrophy, both of which are associated with specific morphological and functional changes of the myocardium. Glycosaminoglycans (GAGs) are complex molecules involved both in tissue morphology and function. In the present study, we investigated the effects of neurogenic hypertension and subsequent antihypertensive treatment with furosemide, on heart hypertrophy and the content of GAGs in the myocardium. Neurogenic hypertension was achieved in male Wistar rats by bilateral aortic denervation (bAD). At days 2, 7 and 15 after surgery, animals were sacrificed and the hearts were dissected away, weighted, and homogenized. Total GAGs were assessed by measuring the uronic acid content colorimetrically and individual GAGs were isolated and characterized by enzymatic treatment, with GAG-degrading enzymes, using electrophoresis on polyacrylamide gradient gels and cellulose acetate membranes. In bAD-animals blood pressure, blood pressure lability, heart rate and heart weight were significantly increased 15 days postoperatively. These effects were prevented by treatment with furosemide. Major GAGs identified in the heart were chondroitin sulphates, heparin (H), heparan sulphate (HS) and hyaluronic acid. The content of uronic and the relative content of H and HS in the heart in bAD animals significantly decreased from day 2 to day 15 postoperatively. Furosemide prevented the bAD induced decrease in GAG content. Considering that H and HS are potent inhibitors of cardiomyocyte hypertrophy, our results indicate that heart hypertrophy induced by neurogenic hypertension may be associated with decreases in the relative content of heparin and heparan sulphate in the heart.
Keywords: Aortic denervation; Heart; Glycosaminoglycans; Hypertension; Furosemide;
Flavonoid myricetin inhibits TNF-α-stimulated production of inflammatory mediators by suppressing the Akt, mTOR and NF-κB pathways in human keratinocytes by Da Hee Lee; Chung Soo Lee (164-172).
Flavonoid myricetin has been shown to exhibit anti-inflammatory and anti-oxidant effects. Nevertheless, the effect of myricetin on the TNF-α-stimulated production of inflammatory mediators in keratinocytes has not been studied. Using human keratinocytes, we examined the effect of myricetin on the TNF-α-stimulated production of inflammatory mediators in relation to the Akt, mTOR and NF-κB pathways, which regulate the transcription genes involved in immune and inflammatory responses. TNF-α stimulated production of the inflammatory mediators and reactive oxygen species in keratinocytes, and activation of the Akt, mTOR and NF-κB pathways in HaCaT cells and primary keratinocytes. Myricetin, Akt inhibitor, Bay 11-7085 (an inhibitor of NF-κB activation), rapamycin (mTOR inhibitor) and N-acetylcysteine attenuated TNF-α-induced activation of Akt, mTOR and NF-κB. Myricetin and N-acetylcysteine attenuated the TNF-α-stimulated production of cytokines and chemokines, and production of reactive oxygen species in keratinocytes. The results show that myricetin may reduce TNF-α-stimulated inflammatory mediator production in keratinocytes by suppressing the activation of the Akt, mTOR and NF-κB pathways. The effect of myricetin appears to be associated with inhibition of the production of reactive oxygen species. Further, myricetin appears to attenuate the proinflammatory mediator-induced inflammatory skin diseases.
Keywords: Keratinocytes; Tumor necrosis factor-α; Myricetin; Inflammatory mediator production; Akt, mTOR and NF-κB pathways;
Protective effects of Celastrol on diethylnitrosamine-induced hepatocellular carcinoma in rats and its mechanisms by Wei Chang; Wei He; Pei-Pei Li; Sha-Sha Song; Ping-Fan Yuan; Jing-Tao Lu; Wei Wei (173-180).
Celastrol, an active ingredient of Tripterygium Wilfordii, is a traditional Chinese medicinal herb, which has attracted interests for its potential anti-inflammatory and anti-cancer activities. The aim of this study was to evaluate the anti-tumor effect of Celastrol against diethylnitrosamine (DEN)-induced hepatocellular carcinoma (HCC) in rats and furthermore, to explore the underlying mechanism. Sprague-Dawley rats were intragastrically administered with DEN (10 mg/kg) for 6 days every week and persisting 16 weeks. The number of nodules was calculated. Hematoxylin-Eosin (HE) staining was used to evaluate the hepatic pathological lesions. The levels of serum alanine aminotransferase (ALT), glutamic oxalacetic transaminase (AST), alkaline phosphatase (ALP) and alpha fetoprotein (AFP) were analyzed by Elisa kits, and the protein levels of p53, Murine double minute (MDM) 2, Bax, Bcl-2, Bcl-xl, cytochrome C, Caspase-3, Caspase-9 and Poly (ADP-ribose) polymerase (PARP) were analyzed by western blot. The results showed that Celastrol could significantly decrease the mortality, the number of tumor nodules and the index of liver in the Celastrol groups compared with DEN-treated group. Moreover, Celastrol obviously improved the hepatic pathological lesions and decreased the elevated levels of ALT, AST, ALP and AFP. Meanwhile, Celastrol suppressed the expression of the protein MDM2, activated the intrinsic mitochondrial apoptosis pathway induced by p53, inhibited anti-apoptotic Bcl-2 and Bcl-xl, induced the pro-apoptotic Bax, cytochrome C, PARP and caspases. These results suggested that Celastrol had a good therapeutic action in reversing DEN-induced HCC rats, which may be associated with the apoptosis of hepatoma cells induced by Celastrol.Display Omitted
Keywords: Celastrol; Hepatocellular carcinoma; Diethylnitrosamine; Apoptosis; p53; Bax/Bcl-2;
Involvement of AMPA/kainate and GABAA receptors in topiramate neuroprotective effects against methylphenidate abuse sequels involving oxidative stress and inflammation in rat isolated hippocampus by Majid Motaghinejad; Manijeh Motevalian (181-191).
Abuses of methylphenidate (MPH) as psychostimulant cause neural damage of brain cells. Neuroprotective properties of topiramate (TPM) have been indicated in several studies but its exact mechanism of action remains unclear. The current study evaluates protective role of various doses of TPM and its mechanism of action in MPH induced oxidative stress and inflammation. The neuroprotective effects of various doses of TPM against MPH induced oxidative stress and inflammation were evaluated and then the action of TPM was studied in presence of domoic acid (DOM), as AMPA/kainate receptor agonist and bicuculline (BIC) as GABAA receptor antagonist, in isolated rat hippocampus. Open Field Test (OFT) was used to investigate motor activity changes. Oxidative, antioxidant and inflammatory factors were measured in isolated hippocampus. TPM (70 and 100 mg/kg) decreased MPH induced motor activity disturbances and inhibit MPH induced oxidative stress and inflammation. On the other hand pretreatment of animals with DOM or BIC, inhibit this effect of TPM and potentiate MPH induced motor activity disturbances and increased lipid peroxidation, mitochondrial oxidized form of glutathione (GSSG) level, interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in isolated hippocampal cells and decreased reduced form of glutathione (GSH) level, superoxide dismutase, glutathione peroxidase and glutathione reductase activity. It seems that TPM can protect cells of hippocampus from oxidative stress and neuroinflammation and it could be partly by activation of GABAA receptor and inhibition of AMPA/kainite receptor.
Keywords: Methylphenidate; Topiramate; Oxidative stress and inflammation;
Curcumin in depressive disorders: An overview of potential mechanisms, preclinical and clinical findings by Fernanda Neutzling Kaufmann; Marta Gazal; Clarissa Ribeiro Bastos; Manuella Pinto Kaster; Gabriele Ghisleni (192-198).
Considering the high prevalence of psychiatric disorders, its social burden and the limitations of currently available treatments, alternative therapeutic approaches targeting different biological pathways have been investigated. Curcumin is a natural compound with multi-faceted pharmacological properties, interacting with several neurotransmitter systems and intracellular signaling pathways involved in mood regulation. Also, curcumin has anti-inflammatory, antioxidant and neurotrophic effects, suggesting a strong potential to manage conditions associated with neurodegeneration, such as psychiatric disorders. Most literature data focused on the potential of curcumin to counteract behavioral and neurochemical alterations in preclinical models of depression. The findings still need to be further explored and clinical reports share some controversial results that might be associated with its low systemic bioavailability following oral administration. Other psychiatric disorders also have neurochemical alterations similar to those found in depression, including neurotoxicity, oxidative stress and neuroinflammation. Despite the limited number of reports, preclinical models investigated the potential role for curcumin in anxiety, bipolar disorder, post-traumatic stress disorder and autism spectrum disorders. Here, we will summarize the cellular targets of curcumin relevant to psychiatric disorders and its effects in preclinical and clinical studies with depression, anxiety disorders and other psychiatric related conditions.
Keywords: Curcumin; Major depression; Psychiatric disorders; Curcumin properties;
Interactions between cannabinoid receptor agonists and mu opioid receptor agonists in rhesus monkeys discriminating fentanyl by David R. Maguire; Charles P. France (199-206).
Cannabinoid receptor agonists such as delta-9-tetrahydrocannabinol (Δ9-THC) enhance some (antinociceptive) but not other (positive reinforcing) effects of mu opioid receptor agonists, suggesting that cannabinoids might be combined with opioids to treat pain without increasing, and possibly decreasing, abuse. The degree to which cannabinoids enhance antinociceptive effects of opioids varies across drugs insofar as Δ9-THC and the synthetic cannabinoid receptor agonist CP55940 increase the potency of some mu opioid receptor agonists (e.g., fentanyl) more than others (e.g., nalbuphine). It is not known whether interactions between cannabinoids and opioids vary similarly for other (abuse-related) effects. This study examined whether Δ9-THC and CP55940 differentially impact the discriminative stimulus effects of fentanyl and nalbuphine in monkeys (n=4) discriminating 0.01 mg/kg of fentanyl (s.c.) from saline. Fentanyl (0.00178–0.0178 mg/kg) and nalbuphine (0.01–0.32 mg/kg) dose-dependently increased drug-lever responding. Neither Δ9-THC (0.032–1.0 mg/kg) nor CP55940 (0.0032–0.032 mg/kg) enhanced the discriminative stimulus effects of fentanyl or nalbuphine; however, doses of Δ9-THC and CP55940 that shifted the nalbuphine dose-effect curve markedly to the right and/or down were less effective or ineffective in shifting the fentanyl dose-effect curve. The mu opioid receptor antagonist naltrexone (0.032 mg/kg) attenuated the discriminative stimulus effects of fentanyl and nalbuphine similarly. These data indicate that the discriminative stimulus effects of nalbuphine are more sensitive to attenuation by cannabinoids than those of fentanyl. That the discriminative stimulus effects of some opioids are more susceptible to modification by drugs from other classes has implications for developing maximally effective therapeutic drug mixtures with reduced abuse liability.
Keywords: Opioid; Cannabinoid; Drug-drug interactions; Drug discrimination; Monkeys;