European Journal of Pharmacology (v.708, #1-3)
Editorial Board (ii).
Celastrol, an inhibitor of heat shock protein 90β potently suppresses the expression of matrix metalloproteinases, inducible nitric oxide synthase and cyclooxygenase-2 in primary human osteoarthritic chondrocytes by Qian-hai Ding; Ye Cheng; Wei-ping Chen; Hui-ming Zhong; Xiang-hua Wang (1-7).
Overexpression of matrix metalloproteinases (MMPs), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) have long been suggested to play crucial roles in the progression of osteoarthritis. Studies have showed that selective MMPs, iNOS and COX-2 inhibitors possess great potential as chondroprotective agents for osteoarthritis. Therefore, there have been intensive efforts to develop novel natural compounds that target MMPs, iNOS and COX-2 activation. As interleukin-1β (IL-1β) is one of the key proinflammatory cytokines contributing to the progression in osteoarthritis, we investigated the effect of celastrol, a triterpenoid compound extracted from the Chinese herb Tript erygium wilfordii Hook F, in neutralizing the inflammatory effects of IL-1β on MMPs, iNOS and COX-2 expression as well as nitric oxide (NO) and prostaglandin E2 (PGE2) production. Protein expression was detected by Western blotting or by enzyme-linked immunosorbent assay (ELISA); messenger RNA (mRNA) expression was examined by real-time reverse transcription-polymerase chain reaction analysis and the involvement of signal pathway was assessed by transient transfection and luciferase activity assay. We found that treatment of primary human osteoarthritic chondrocytes with various concentrations of celastrol resulted in striking decrease in the expression of MMP-1, MMP-3, MMP-13, iNOS-2 and COX-2. In addition, celastrol treatment of cells also inhibited the activation of nuclear factor-kappa B (NF-kappaB). Taken together, we provide evidence that celastrol can protect human chondrocytes by downregulating the expression of MMPs, iNOS and COX-2. We suggest that celastrol could be a useful agent for prevention and treatment of osteoarthritis.
Keywords: Celastrol; Matrix metalloproteinases; Inducible nitric oxide synthase; Cyclooxygenase-2; Chondrocytes; Osteoarthritis;
A novel compound DSC suppresses lipopolysaccharide-induced inflammatory responses by inhibition of Akt/NF-κB signalling in macrophages by Xin-Hua Liu; Li-Long Pan; Yao-Ling Jia; Dan Wu; Qing-Hui Xiong; Yang Wang; Yi-Zhun Zhu (8-13).
A novel compound [4-(2-acetoxy-3-((R)-3-(benzylthio)-1-methoxy-1-oxopropan-2-ylamino)-3-oxopropyl)-1,2-phenylene diacetate (DSC)], derived from Danshensu, exerted cytoprotective effects by anti-oxidative and anti-apoptotic activities in vitro. Herein, we reported the protective effects of DSC on lipopolysaccharide (LPS)-induced inflammatory responses in murine RAW264.7 macrophages and the underlying mechanisms. We showed that DSC concentration-dependently attenuated nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression with less cytotoxicity. Signal transduction studies indicated that DSC significantly inhibited LPS-induced phosphorylation of Akt, but not c-Jun N-terminal kinase 1/2, p38, or extracellular signal-regulated kinase 1/2. Meanwhile, LPS-induced nuclear translocation of nuclear factor-κB (NF-κB) p65 was decreased by DSC. Furthermore, a phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 significantly suppressed LPS-induced NF-κB p65 nuclear translocation, iNOS expression, and NO production, which was also mimicked by pretreatment with DSC. These results suggested that DSC attenuated LPS-induced inflammatory response in macrophages, at least in part, through suppression of PI3K/Akt signaling and NF-κB activation.Display Omitted
Keywords: Danshensu-cysteine derivative; Inflammation; Lipopolysaccharide; Inducible nitric oxide synthase; Nitric oxide;
Novel effect of 2-aminoethoxydiphenylborate through inhibition of calcium sensitization induced by Rho kinase activation in human detrusor smooth muscle by Nouval Shahab; Shunichi Kajioka; Ryosuke Takahashi; Maya Hayashi; Shinsuke Nakayama; Kazuyuki Sakamoto; Masahiro Takeda; Noriyuki Masuda; Seiji Naito (14-20).
Since the introduction of 2-aminoethoxydiphenylborate (2-APB) as a membrane permeable modulator of inositol (1,4,5)-trisphosphate receptors, subsequent studies have revealed additional actions of this chemical on multiple Ca2+-permeable ionic channels in the plasma membrane. However, no reports have yet examined 2-APB as a modulator targeting contractile machinery in smooth muscle, independent of Ca2+ mobilization, namely Ca2+ sensitization. Here, we assessed whether or not 2-APB affects intracellular signaling pathways of Ca2+ sensitization for contraction using α-toxin permeabilized human detrusor smooth muscle. Although contractions were induced by application of Ca2+-containing bath solutions, 2-APB had little effect on contractions induced by 1 µM Ca2+ alone but significantly reversed the carbachol-induced augmentation of Ca2+-induced contraction in the presence of guanosine triphosphate (carbachol-induced Ca2+ sensitization). The rho kinase inhibitor Y-27632 and protein kinase C inhibitor GF-109203X also reversed the carbachol-mediated Ca2+ sensitization. Additional application of 2-APB caused a small but significant further attenuation of the contraction in the presence of GF-109203X but not in the presence of Y-27632. Like carbachol, the rho kinase activator; sphingosylphosphorylcholine, protein kinase C activator; phorbol 12,13 dibutyrate, and myosin light chain phosphatase inhibitor; calyculin-A all induced Ca2+ sensitization. However, the inhibitory activity of 2-APB was limited with sphingosylphosphorylcholine-induced Ca2+ sensitization. This study revealed a novel inhibitory effect of 2-APB on smooth muscle contractility through inhibition of the rho kinase pathway.
Keywords: Human detrusor smooth muscle; Permeabilization; α-toxin; 2-APB; Calcium desensitization; Rho kinase;
Arctigenin ameliorates inflammation in vitro and in vivo by inhibiting the PI3K/AKT pathway and polarizing M1 macrophages to M2-like macrophages by Supriya R. Hyam; In-Ah Lee; Wan Gu; Kyung-Ah Kim; Jin-Ju Jeong; Se-Eun Jang; Myung Joo Han; Dong-Hyun Kim (21-29).
Seeds of Arctium lappa, containing arctigenin and its glycoside arctiin as main constituents, have been used as a diuretic, anti-inflammatory and detoxifying agent in Chinese traditional medicine. In our preliminary study, arctigenin inhibited IKKβ and NF-κB activation in peptidoglycan (PGN)- or lipopolysaccharide (LPS)-induced peritoneal macrophages. To understand the anti-inflammatory effect of arctigenin, we investigated its anti-inflammatory effect in LPS-stimulated peritoneal macrophages and on LPS-induced systemic inflammation as well as 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice. Arctigenin inhibited LPS-increased IL-1β, IL-6 and TNF-α expression in LPS-stimulated peritoneal macrophages, but increased LPS-reduced IL-10 and CD204 expression. Arctigenin inhibited LPS-induced PI3K, AKT and IKKβ phosphorylation, but did not suppress LPS-induced IRAK-1 phosphorylation. However, arctigenin did not inhibit NF-κB activation in LPS-stimulated PI3K siRNA-treated peritoneal macrophages. Arctigenin suppressed the binding of p-PI3K antibody and the nucleus translocation of NF-κB p65 in LPS-stimulated peritoneal macrophages. Arctigenin suppressed blood IL-1β and TNF-α level in mice systemically inflamed by intraperitoneal injection of LPS. Arctigenin also inhibited colon shortening, macroscopic scores and myeloperoxidase activity in TNBS-induced colitic mice. Arctigenin inhibited TNBS-induced IL-1β, TNF-α and IL-6 expression, as well as PI3K, AKT and IKKβ phosphorylation and NF-κB activation in mice, but increased IL-10 and CD204 expression. However, it did not affect IRAK-1 phosphorylation. Based on these findings, arctigenin may ameliorate inflammatory diseases, such as colitis, by inhibiting PI3K and polarizing M1 macrophages to M2-like macrophages.Display Omitted
Keywords: Arctigenin; Inflammation; Macrophages; PI3K; Polarization;
Identification of novel pyrazoloquinazolinecarboxilate analogues to inhibit nerve growth factor in vitro by Joseph K. Eibl; Bridget C. Strasser; Gregory M. Ross (30-37).
Nerve growth factor (NGF) is known to regulate the development and survival of select populations of neurons via its binding/activation of the TrkA and p75NTR receptors. However, in some physiological circumstances NGF dysregulation can result in debilitating pathologies, including diabetic neuropathies, interstitial cystitis and fibromyalgia. Thus, the identification of small molecules which inhibit NGF signalling have significant therapeutic potential. PD 90780, Ro 08-2750, and ALE 0540 are small molecules that have been reported to bind and inhibit NGF activity. Importantly, the docking site of these compounds is hypothesised to occur at the loop I/IV cleft of NGF—a region which is required for efficient and selective binding of this neurotrophin to its receptor(s). Molecular modelling predicts a number of previously reported NGF antagonists (PD 90780, ALE 0540, and Ro 08-2750) share conserved molecular features, and these drug-like small molecules have the ability to bind and modify the molecular topology of NGF. In order to understand the putative mechanism of binding, we synthesised a pyrazoloquinazolinecarboxilate analogue series and tested each compound in an NGF-dependent PC12 cell differentiation assay. In vitro data confirms that the pyrazoloquinazolinecarboxilate analogues functionally inhibit NGF's effects on PC12 cell differentiation. The results of this study provide evidence to refine the docking mode of pyrazoloquinazolinecarboxilate based compounds for the purposes of inhibiting NGF in vitro. In addition, we identified series analogue PQC 083 (IC50=7.0 µM; CI=5.4−10.1 µM) which displays markedly higher potency than previously described NGF antagonists.
Keywords: Neurotrophin antagonist; NGF antagonist; PC12 cells; TrkA; Neurotrophin inhibition;
Resistance to depression through interference of opioid and nitrergic systems in bile-duct ligated mice by Arya Haj-Mirzaian; Nikoo Hamzeh; Mehrak Javadi-Paydar; Mohammad Reza Abdollahzadeh Estakhri; Ahmad R. Dehpour (38-43).
This study was done to investigate the effects of opioid and nitrergic systems on depression in an experimental model of cholestasis in mice, since elevated levels of these substances are seen in cholestatic subjects. Bile duct ligated (BDL) and sham-operated mice were forced to swim individually and the immobility time in the last 4 min of the 6 min test was evaluated to determine the effects of cholestasis on depression. To assess the possible involvement of endogenous opioids and nitric oxide (NO), effective and sub-effective doses of naltrexone an antagonist of opioid receptors, and N-nitro-l-arginine methyl ester (L-NAME) a non-specific NO synthase inhibitor, were administrated acutely and chronically to BDL and Sham-operated mice and then their immobility time was measured in forced swimming test (FST). The immobility time significantly decreased after bile-duct ligation. Naltrexone and L-NAME significantly reversed antidepressant like effect of cholestasis. Co-administration of sub-effective doses of naltrexone and L-NAME also reversed antidepressant effect in FST in chronic administration. But acute drug administration did not reverse the anti-depressant effect of cholestasis. We have shown that elevated levels of endogenous opioids and NO in cholestatic mice induce an anti depressant like effect, causing a reduction in the mice immobility time in FST. And the study also showed the predominant effect of opioid system and NO modulation of that in anti-depressant like effect of cholestasis.
Keywords: Depression; Cholestasis; Nitric oxide; Opioid system;
Effect of berberine on cell cycle arrest and cell survival during cerebral ischemia and reperfusion and correlations with p53/cyclin D1 and PI3K/Akt by Yu-Shuang Chai; Jun Hu; Fan Lei; Yu-Gang Wang; Zhi-Yi Yuan; Xi Lu; Xin-Pei Wang; Feng Du; Dong Zhang; Dong-Ming Xing; Li-Jun Du (44-55).
Berberine acted as a natural medicine with multiple pharmacological activities. In the present study, we examined the effect of berberine against cerebral ischemia damage from cell cycle arrest and cell survival. Oxygen–glucose deprivation of PC12 cells and primary neurons, and carotid artery ligation in mice were used as in vitro and in vivo cerebral ischemia models. We found that the effect of berberine on cell cycle arrest during ischemia was mediated by decreased p53 and cyclin D1, increased phosphorylation of Bad (higher expression of p-Bad and higher ratio of p-Bad to Bad) and decreased cleavage of caspase 3. Meanwhile, berberine activated the PI3K/Akt pathway during the reperfusion, especially the phosphor-activation of Akt, to promote the cell survival. The neural protective effect of berberine was remained in the presence of inhibitor of mitogen-activated protein/extracellular signal-regulated kinase (MEK), but was suppressed by the inhibitors of PI3K and Akt. We demonstrated that berberine induced cell cycle arrest and cell survival to resist cerebral ischemia injury.Display Omitted
Keywords: Berberine; Cell cycle arrest; Cell survival; Cerebral ischemia and reperfusion;
Hyperactivity: Glycogen synthase kinase-3 as a therapeutic target by Marjelo A. Mines (56-59).
The diagnosis of hyperactivity-associated disorders has increased within the past few years. The prevalence of hyperactivity-associated disorders is indicative of the need to more fully understand the underlying causes and to develop improved therapeutic interventions. There is increasing evidence that glycogen synthase kinase-3 (GSK3) mediates locomotor hyperactivity in a number of animal models, and therefore may be a potential target for therapeutic intervention in hyperactivity-associated behaviors. In this review, we discuss 1) the effect of manipulations of GSK3 in the absence of drugs and disorders on locomotor activity, 2) the role of GSK3 in drug-induced hyperactivity in rodents, and 3) regulation of locomotor activity by GSK3 in transgenic mouse models related to specific disorders. These studies link GSK3 regulation and activity to hyperactivity-associated behaviors and disease pathologies.
Keywords: Amphetamine; Attention-deficit/hyperactivity disorder; Glycogen synthase-kinase 3; Locomotor hyperactivity; Stimulants;
Modulation of transcriptional responses by poly(I:C) and human rhinovirus: Effect of long-acting β2-adrenoceptor agonists by Christopher F. Rider; Anna Miller-Larsson; David Proud; Mark A. Giembycz; Robert Newton (60-67).
Exacerbations of asthma, a chronic inflammatory respiratory disease, are associated with viral upper respiratory tract infections involving human rhinovirus. Although glucocorticoids (corticosteroids) effectively control airways inflammation in many asthmatics, human rhinovirus-associated exacerbations show reduced glucocorticoid responsiveness. Using human bronchial epithelial BEAS-2B cells, we show that human rhinovirus reduced glucocorticoid-inducible activation of glucocorticoid response element (GRE) reporter systems in a time- and concentration-dependent manner. The synthetic double-stranded viral RNA mimetic, polyinosinic:polycytidylic acid (poly(I:C)), also reduced activation of GRE reporter systems in BEAS-2B and pulmonary A549 cells. In addition, poly(I:C) decreased transcription from cAMP response element (CRE)-, TATA-, simian virus 40- and nuclear factor-kappa B (NF-κB)-dependent reporter systems. The effects of poly(I:C) on GRE-reporter activation were countered by the long-acting β2-adrenoceptor agonists, formoterol and salmeterol. Likewise, increased expression of the gene cyclin-dependent kinase inhibitor 1C (CDKN1C; p57KIP2) by dexamethasone was reduced by poly(I:C), but was substantially enhanced by the addition of formoterol. Poly(I:C) induced the expression of interleukin-8 (IL8; CXCL8) and this was significantly decreased by dexamethasone, formoterol or their combination. This confirms that not all transcriptional responses were attenuated by poly(I:C) and that decreased glucocorticoid-dependent transcription can be counteracted by the addition of long-acting β2-adrenoceptor agonists. These data show how human rhinovirus may attenuate glucocorticoid-induced transcription to reduce anti-inflammatory activity. However, addition of long-acting β2-adrenoceptor agonist to the glucocorticoid functionally restored this response and shows how glucocorticoid plus long-acting β2-adrenoceptor agonist combinations may prove beneficial during virus-induced exacerbations of asthma.
Keywords: Asthma; Long-acting beta2-adrenoceptor agonist; Combination therapy; Glucocorticoid resistance; Corticosteroid resistance; Human rhinovirus;
A catalytically-inactive snake venom Lys49 phospholipase A2 homolog induces expression of cyclooxygenase-2 and production of prostaglandins through selected signaling pathways in macrophages by Vanessa Moreira; Pollyana Cristina Maggio de Castro Souto; Marco Aurélio Ramirez Vinolo; Bruno Lomonte; José María Gutiérrez; Rui Curi; Catarina Teixeira (68-79).
The effects of a snake venom Lys-49 phospholipase A2 (PLA2) homolog named MT-II, devoid of enzymatic activity, on the biosynthesis of prostaglandins and protein expression of cyclooxygenase-2 (COX-2) and signaling pathways involved were evaluated in mouse macrophages in culture and in peritoneal cells ex vivo. Stimulation of macrophages with MT-II leads to production of prostaglandin D2 (PGD2) and prostaglandin E2 (PGE2) and protein expression of COX-2 and microsomal prostaglandin E synthase-1 (mPGES-1). Inhibition of cytosolic PLA2 (cPLA2), but not Ca2+ independent PLA2 (iPLA2) reduced release of PGD2 and PGE2 and expression of COX-2 induced by MT-II. Inhibition of nuclear factor κB (NF-κB) significantly reduced MT-II-induced PGE2, but not PGD2 production and COX-2 expression. Inhibitors of either protein kinase C (PKC), protein tyrosine kinase (PTK), or extracellular signal-regulated kinase (ERK) pathways abrogated MT-II-induced NF-κB activation and reduced COX-2 expression and PGE2 release, whereas the p38 mitogen-activated protein kinase (MAPK) inhibitor reduced MT-II-induced COX-2 expression and PGD2 production. Inhibition of phosphatidylinositol-3-kinase (PI3K) pathway abrogated MT-II-induced NF-κB activation, but affected neither prostaglandins production nor COX-2 expression. MT-II-induced production of PGD2 and PGE2 and COX-2 expression were also observed in vivo after intraperitoneal injection into mice. Collectively, our data demonstrate that a catalytically-inactive PLA2 homolog is capable of inducing prostaglandins biosynthesis and COX-2 expression in macrophages in both in vitro and in vivo models, indicating that the enzymatic activity of PLA2 is not necessary to trigger these effects. MT-II-activated NF-κB, cPLA2 and distinct protein kinases are the principal steps involved in these cellular events.
Keywords: Snake venom sPLA2 homolog; Prostaglandin; Cyclooxygenase; Macrophage; Signaling pathway; NF-κB;
Anti-nociceptive and anti-allodynic activity of aliskiren in various pain models by Rakesh B. Patel; Vishwanath D. Pawar; Kanaiyalal D. Prajapati; Bhavin M. Sonara; Shrikalp S. Deshpande; Gaurang B. Shah; Mukul R. Jain (80-87).
In the present study, we have investigated the anti-nociceptive and anti-allodynic activity of the renin inhibitor, aliskiren, in various pain models. The anti-nociceptive activity of aliskiren was investigated in chemically-induced pain, orofacial pain and centrally mediated pain models. Anti-allodynic activity was evaluated in post-operative and neuropathic pain models. The levels of TNF-α and IL-6 were measured in homogenates of hind paw as markers of inflammation in formalin injected mice. Intraperitoneal administration of aliskiren (1–50 mg/kg) showed anti-nociceptive activity in the writhing test, formalin hind paw test, capsaicin induced pain, and orofacial pain tests in ICR mice in a dose dependent manner. Aliskiren (50 mg/kg, i.p.) reduced levels of TNF-α and IL-6 in hind paw homogenates of formalin-injected mice. Aliskiren (50 mg/kg, i.p.) did not show any analgesic activity in hot-plate and tail-flick tests, indicating the absence of centrally mediated anti-nociceptive effects. On the other hand, intra-plantar administration of aliskiren (0.1, 0.5 and 1 mg) showed analgesic activity in rat formalin tests, indicating a locally mediated effect. Aliskiren (30–100 mg/kg, i.p.) showed anti-allodynic activity in post-operative pain and chronic constriction injury-induced neuropathic pain in Sprague Dawley rats. This data suggests that aliskiren may have the potential to be used as an anti-nociceptive and anti-allodynic agent.
Keywords: Aliskiren; Renin inhibitor; Formalin; Hot plate test; Post-operative pain; Neuropathic pain;
Improvement of the circulatory function partially accounts for the neuroprotective action of the phytoestrogen genistein in experimental ischemic stroke by Belén Cortina; Germán Torregrosa; María Castelló-Ruiz; María C. Burguete; Antonio Moscardó; Ana Latorre; Juan B. Salom; Juana Vallés; María T. Santos; Enrique Alborch (88-94).
We tested the hypothesis that the phytoestrogen genistein protects the brain against ischemic stroke by improving the circulatory function in terms of reduced production of thromboxane A2 and leukocyte–platelet aggregates, and of preserved vascular reactivity. Ischemia-reperfusion (90 min-3 days, intraluminal filament) was induced in male Wistar rats, and functional score and cerebral infarct volume were the end points examined. Genistein (10 mg/kg/day) or vehicle (β-cyclodextrin) was administered at 30 min after ischemia or sham-operation. Production of thromboxane A2 and leukocyte–platelet aggregates, as well as reactivity of carotid artery to U-46619 (thromboxane A2 analogue) and to platelet releasate was measured. At 3 days post-ischemia, both improvement in the functional examination and reduction in the total infarct volume were shown in the ischemic genistein-treated group. Genistein significantly reverted both the increased thromboxane A2 concentration and the increased leukocyte–platelet aggregates production found in samples from the ischemic vehicle-treated group. Both U-46619 and platelet releasate elicited contractions of the carotid artery, which were significantly lower in the ischemic vehicle-treated group. Genistein significantly restored both the decreased U-46619- and the decreased platelet releasate-elicited contractile responses. In conclusion, genistein protects the brain against an ischemia-reperfusion challenge, at least in part, by its beneficial effects on the circulatory function.
Keywords: Genistein; Isoflavone; Phytoestrogen; Platelet; Stroke; Thromboxane A2;
Strain differences in profiles of dopaminergic neurotransmission in the prefrontal cortex of the BALB/C vs. C57Bl/6 mice: Consequences of stress and afobazole by Elmira A. Anderzhanova; Heidi Bächli; Olga A. Buneeva; Victor B. Narkevich; Alexei E. Medvedev; Christoph K. Thoeringer; Carsten T. Wotjak; Vladimir S. Kudrin (95-104).
We found that in mice the basal activity of monoamine oxidase B (MAO-B) in the medial prefrontal cortex (mPFC) is lower in BALB/C than in C57Bl/6J mice, whereas activity of MAO-A is similar between strains. BALB/C mice, in comparison to C57Bl/6N mice, have higher basal content of dopamine in the mPFC, in both microdialysates and tissue content. Novelty stress (open field test) elicits a further increase in the microdialysate levels of dopamine in BALB/C, but not in C57Bl/6N mice; a subsequent accumulation of extracellular 3,4-dioxyphenylacetic acid (DOPAC) reaffirms the difference in catabolic capacity of monoaminergic systems between the strains. We demonstrated that in stress-susceptible BALB/C mice the novel anxiolytic afobazole, 5 mg/kg, selectively mitigates trait anxiety; however it does not change the behavioral response in stress-resilient C57Bl/6N mice. Afobazole inhibits MAO-A in in vitro; it also lowers the microdialysate DOPAC levels in both strains (which testifies to its MAO-A inhibiting activity in vivo) and slightly suppresses dopamine release when elevated. Therefore, it is likely that the drug may mediate its anxiolytic activity via modulation of volume dopaminergic transmission at level of the mPFC.
Keywords: Stress; Dopamine; MAO; BALB/C mice; C57Bl/6 mice; Anxiety; Afobazole; Microdialysis;
Axonal voltage-gated ion channels as pharmacological targets for pain by Mihai Moldovan; Susana Alvarez; Mette Romer Rosberg; Christian Krarup (105-112).
Upon peripheral nerve injury (caused by trauma or disease process) axons of the dorsal root ganglion (DRG) somatosensory neurons have the ability to sprout and regrow/remyelinate to reinnervate distant target tissue or form a tangled scar mass called a neuroma. This regenerative response can become maladaptive leading to a persistent and debilitating pain state referred to as chronic pain corresponding to the clinical description of neuropathic/chronic inflammatory pain. There is little agreement to what causes peripheral chronic pain other than hyperactivity of the nociceptive DRG neurons which ultimately depends on the function of voltage-gated ion channels.This review focuses on the pharmacological modulators of voltage-gated ion channels known to be present on axonal membrane which represents by far the largest surface of DRG neurons. Blockers of voltage-gated Na+ channels, openers of voltage-gated K+ channels and blockers of hyperpolarization-activated cyclic nucleotide-gated channels that were found to reduce neuronal activity were also found to be effective in neuropathic and inflammatory pain states. The isoforms of these channels present on nociceptive axons have limited specificity. The rationale for considering axonal voltage-gated ion channels as targets for pain treatment comes from the accumulating evidence that chronic pain states are associated with a dysregulation of these channels that could alter their specificity and make them more susceptible to pharmacological modulation. This drives the need for further development of subtype-specific voltage-gated ion channels modulators, as well as clinically available neurophysiological techniques for monitoring axonal ion channel function in peripheral nerves.
Keywords: Nerve regeneration; Neuroma; Node of Ranvier; Internode; Voltage-gated ion channels; Acquired channelopathies; Subtype-selective voltage-gated ion channel blockers; Rodent pain models; Nerve excitability testing;
Comparative efficacy of TACI-Ig with TNF-alpha inhibitor and methotrexate in DBA/1 mice with collagen-induced arthritis by Lingling Zhang; Peipei Li; Shanshan Song; Yunjie Liu; Qingtong Wang; Yan Chang; Yujing Wu; Jingyu Chen; Wendi Zhao; Yunfang Zhang; Aiwu Zhou; Wei Wei (113-123).
The efficacies of TACI-Ig, rhTNFR:Fc and Methotrexate were compared in collagen-induced arthritis (CIA) mice. Sixty animals were divided into six groups: TACI-Ig (9 mg/kg), rhTNFR:Fc (4 mg/kg), Methotrexate (2 mg/kg) and IgG-Fc (9 mg/kg) groups and were given medication for six weeks. Meanwhile, normal and CIA mice were given as control. The different efficacies of drugs were evaluated by the analyses of ankle joints and spleens pathology, cytokines, T and B lymphocytes subsets. TACI-Ig and rhTNFR:Fc reduced arthritis scores seven days later than that of Methotrexate. TACI-Ig and Methotrexate were superior to rhTNFR:Fc in reduction synovial hyperplasia and cell infiltration scores. The same result was observed for scores of spleens histopathology. TACI-Ig and Methotrexate presented higher efficacy than rhTNFR:Fc on B lymphocyte stimulator, but TACI-Ig was inferior to rhTNFR:Fc on TNF-alpha. TACI-Ig and Methotrexate could reduce significantly IgA and IgM, but rhTNFR:Fc had no effects on these immunoglobulins. TACI-Ig had more efficacy than rhTNFR:Fc in the decrease of CD4+CD154+ T cell. TACI-Ig and Methotrexate also reduced CD4+CD69+ T cell, rhTNFR:Fc had no effects on the T cell subset. TACI-Ig and Methotrexate were superior to rhTNFR:Fc on CD4+CD62L+T cells. TACI-Ig and Methotrexate could reduce CD19+IgD+ and CD19+CD21+ B cells, but rhTNFR:Fc had no obvious effect on above B cells subsets. TACI-Ig is as effective as rhTNFR:Fc and Methotrexate on CIA mice by ameliorating joint and spleen pathology, regulating T and B lymphocytes function, although different mechanisms among them. This study would be useful for treatment selection of rheumatoid arthritis in different pathological conditions.
Keywords: TACI-Ig; RhTNFR:Fc; Methotrexate; B lymphocyte stimulator; Lymphocyte; Collagen-induced arthritis;
Diabetes confers a vasoprotective role to the neurocompensatory response elicited by carotid balloon injury: Consequences on contralateral carotid tone and blood flow by Larissa Pernomian; Mayara S. Gomes; Fernando M.A. Corrêa; Carolina B.A. Restini; Leandra N.Z. Ramalho; Ana M. de Oliveira (124-138).
The purpose from this study was to investigate the consequences of sensory neurocompensation to carotid balloon injury in diabetic rats on angiotensin II-induced contraction and basal blood flow in contralateral carotid. Concentration-response curves for angiotensin II and blood flow were obtained in contralateral carotid from non-treated or capsaicin-treated streptozotocin-induced diabetic rats that underwent carotid balloon injury. Diabetes increased angiotensin II-induced contraction and impaired the blood flow in non-operated rat carotid. In diabetic rats, balloon injury led to neointima formation, which reduced the blood flow in ipsilateral carotid. Carotid balloon injury in diabetic rats reduced angiotensin II-induced contraction and restored the blood flow in contralateral carotid when compared to diabetic non-operated rat carotid. Capsaicin inhibited the effects evoked by carotid balloon injury on diabetic rat contralateral carotid. Endothelium removal, PEG-catalase (hydrogen peroxide scavenger) or l-NPA (neuronal nitric oxide synthase, nNOS, inhibitor) increased angiotensin II-induced contraction in contralateral carotid from diabetic operated rats to the levels observed in diabetic non-operated rat carotid. Our findings suggest that carotid balloon injury in diabetic rats elicits a neurocompensation that attenuates the diabetic hyperreactivity to angiotensin II in contralateral carotid by a sensory nerves-dependent mechanism mediated by hydrogen peroxide derived from endothelial nNOS. This sensory mechanism also restored the blood flow in this vessel, compensating the impaired blood flow in diabetic rat ipsilateral carotid. Thus, our major conclusions are that Diabetes confers a vasoprotective significance to the neurocompensation to carotid balloon injury in preventing further damage at carotid cerebral irrigation after angioplasty in diabetic subjects.
Keywords: Type I-Diabetes; Carotid balloon injury; Angiotensin II; Carotid blood flow; Reactive oxygen species;
Corrigendum to “Eupatolide inhibits lipopolysaccharide-induced COX-2 and iNOS expression in RAW264.7 cells by inducing proteasomal degradation of TRAF6” [Eur. J. Pharmacol. 636 (2010) 173–180] by Jongkyu Lee; Nara Tae; Jung Joon Lee; Taeho Kim; Jeong-Hyung Lee (139).