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Anderson LL, Thompson CH, Hawkins NA, Nath RD, Petersohn AA, Rajamani S, Bush WS, Frankel WN, Vanoye CG, Kearney JA, George AL. Antiepileptic activity of preferential inhibitors of persistent sodium current. Epilepsia 2014; 55:1274-83. [PMID: 24862204 PMCID: PMC4126848 DOI: 10.1111/epi.12657] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2014] [Indexed: 01/25/2023]
Abstract
OBJECTIVE Evidence from basic neurophysiology and molecular genetics has implicated persistent sodium current conducted by voltage-gated sodium (NaV ) channels as a contributor to the pathogenesis of epilepsy. Many antiepileptic drugs target NaV channels and modulate neuronal excitability, mainly by a use-dependent block of transient sodium current, although suppression of persistent current may also contribute to the efficacy of these drugs. We hypothesized that a drug or compound capable of preferential inhibition of persistent sodium current would have antiepileptic activity. METHODS We examined the antiepileptic activity of two selective persistent sodium current blockers ranolazine, a U.S. Food and Drug Administration (FDA)-approved drug for treatment of angina pectoris, and GS967, a novel compound with more potent effects on persistent current, in the epileptic Scn2a(Q54) mouse model. We also examined the effect of GS967 in the maximal electroshock model and evaluated effects of the compound on neuronal excitability, propensity for hilar neuron loss, development of mossy fiber sprouting, and survival of Scn2a(Q54) mice. RESULTS We found that ranolazine was capable of reducing seizure frequency by approximately 50% in Scn2a(Q54) mice. The more potent persistent current blocker GS967 reduced seizure frequency by >90% in Scn2a(Q54) mice and protected against induced seizures in the maximal electroshock model. GS967 greatly attenuated abnormal spontaneous action potential firing in pyramidal neurons acutely isolated from Scn2a(Q54) mice. In addition to seizure suppression in vivo, GS967 treatment greatly improved the survival of Scn2a(Q54) mice, prevented hilar neuron loss, and suppressed the development of hippocampal mossy fiber sprouting. SIGNIFICANCE Our findings indicate that the selective persistent sodium current blocker GS967 has potent antiepileptic activity and that this compound could inform development of new agents.
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Jayaraman A, Christensen A, Moser VA, Vest RS, Miller CP, Hattersley G, Pike CJ. Selective androgen receptor modulator RAD140 is neuroprotective in cultured neurons and kainate-lesioned male rats. Endocrinology 2014; 155:1398-406. [PMID: 24428527 PMCID: PMC3959610 DOI: 10.1210/en.2013-1725] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The decline in testosterone levels in men during normal aging increases risks of dysfunction and disease in androgen-responsive tissues, including brain. The use of testosterone therapy has the potential to increase the risks for developing prostate cancer and or accelerating its progression. To overcome this limitation, novel compounds termed "selective androgen receptor modulators" (SARMs) have been developed that lack significant androgen action in prostate but exert agonist effects in select androgen-responsive tissues. The efficacy of SARMs in brain is largely unknown. In this study, we investigate the SARM RAD140 in cultured rat neurons and male rat brain for its ability to provide neuroprotection, an important neural action of endogenous androgens that is relevant to neural health and resilience to neurodegenerative diseases. In cultured hippocampal neurons, RAD140 was as effective as testosterone in reducing cell death induced by apoptotic insults. Mechanistically, RAD140 neuroprotection was dependent upon MAPK signaling, as evidenced by elevation of ERK phosphorylation and inhibition of protection by the MAPK kinase inhibitor U0126. Importantly, RAD140 was also neuroprotective in vivo using the rat kainate lesion model. In experiments with gonadectomized, adult male rats, RAD140 was shown to exhibit peripheral tissue-specific androgen action that largely spared prostate, neural efficacy as demonstrated by activation of androgenic gene regulation effects, and neuroprotection of hippocampal neurons against cell death caused by systemic administration of the excitotoxin kainate. These novel findings demonstrate initial preclinical efficacy of a SARM in neuroprotective actions relevant to Alzheimer's disease and related neurodegenerative diseases.
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Soya M, Sato M, Sobhan U, Tsumura M, Ichinohe T, Tazaki M, Shibukawa Y. Plasma membrane stretch activates transient receptor potential vanilloid and ankyrin channels in Merkel cells from hamster buccal mucosa. Cell Calcium 2014; 55:208-18. [PMID: 24642224 DOI: 10.1016/j.ceca.2014.02.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 02/05/2014] [Accepted: 02/20/2014] [Indexed: 01/03/2023]
Abstract
Merkel cells (MCs) have been proposed to form a part of the MC-neurite complex with sensory neurons. Many transient receptor potential (TRP) channels have been identified in mammals; however, the activation properties of these channels in oral mucosal MCs remain to be clarified. We investigated the biophysical and pharmacological properties of TRP vanilloid (TRPV)-1, TRPV2, TRPV4, TRP ankyrin (TRPA)-1, and TRP melastatin (TRPM)-8 channels, which are sensitive to osmotic and mechanical stimuli by measurement of intracellular free Ca(2+) concentration ([Ca(2+)]i) using fura-2. We also analyzed their localization patterns through immunofluorescence. MCs showed immunoreaction for TRPV1, TRPV2, TRPV4, TRPA1, and TRPM8 channels. In the presence of extracellular Ca(2+), the hypotonic test solution evoked Ca(2+) influx. The [Ca(2+)]i increases were inhibited by TRPV1, TRPV2, TRPV4, or TRPA1 channel antagonists, but not by the TRPM8 channel antagonist. Application of TRPV1, TRPV2, TRPV4, TRPA1, or TRPM8 channel selective agonists elicited transient increases in [Ca(2+)]i only in the presence of extracellular Ca(2+). The results indicate that membrane stretching in MCs activates TRPV1, TRPV2, TRPV4, and TRPA1 channels, that it may be involved in synaptic transmission to sensory neurons, and that MCs could contribute to the mechanosensory transduction sequence.
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Chung G, Im ST, Kim YH, Jung SJ, Rhyu MR, Oh SB. Activation of transient receptor potential ankyrin 1 by eugenol. Neuroscience 2013; 261:153-60. [PMID: 24384226 DOI: 10.1016/j.neuroscience.2013.12.047] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Revised: 12/14/2013] [Accepted: 12/20/2013] [Indexed: 12/29/2022]
Abstract
Eugenol is a bioactive plant extract used as an analgesic agent in dentistry. The structural similarity of eugenol to cinnamaldehyde, an active ligand for transient receptor potential ankyrin 1 (TRPA1), suggests that eugenol might produce its effect via TRPA1, in addition to TRPV1 as we reported previously. In this study, we investigated the effect of eugenol on TRPA1, by fura-2-based calcium imaging and patch clamp recording in trigeminal ganglion neurons and in a heterologous expression system. As the result, eugenol induced robust calcium responses in rat trigeminal ganglion neurons that responded to a specific TRPA1 agonist, allyl isothiocyanate (AITC), and not to capsaicin. Capsazepine, a TRPV1 antagonist failed to inhibit eugenol-induced calcium responses in AITC-responding neurons. In addition, eugenol response was observed in trigeminal ganglion neurons from TRPV1 knockout mice and human embryonic kidney 293 cell lines that express human TRPA1, which was inhibited by TRPA1-specific antagonist HC-030031. Eugenol-evoked TRPA1 single channel activity and eugenol-induced TRPA1 currents were dose-dependent with EC50 of 261.5μM. In summary, these results demonstrate that the activation of TRPA1 might account for another molecular mechanism underlying the pharmacological action of eugenol.
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Sikkel MB, MacLeod KT, Gordon F. Letter by Sikkel et al regarding article, "Late sodium current inhibition reverses electromechanical dysfunction in human hypertrophic cardiomyopathy". Circulation 2013; 128:e156. [PMID: 24002720 DOI: 10.1161/circulationaha.113.003070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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81
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Andersson DA, Gentry C, Light E, Vastani N, Vallortigara J, Bierhaus A, Fleming T, Bevan S. Methylglyoxal evokes pain by stimulating TRPA1. PLoS One 2013; 8:e77986. [PMID: 24167592 PMCID: PMC3805573 DOI: 10.1371/journal.pone.0077986] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 09/16/2013] [Indexed: 12/13/2022] Open
Abstract
Diabetic neuropathy is a severe complication of long-standing diabetes and one of the major etiologies of neuropathic pain. Diabetes is associated with an increased formation of reactive oxygen species and the electrophilic dicarbonyl compound methylglyoxal (MG). Here we show that MG stimulates heterologously expressed TRPA1 in CHO cells and natively expressed TRPA1 in MDCK cells and DRG neurons. MG evokes [Ca2+]i-responses in TRPA1 expressing DRG neurons but is without effect in neurons cultured from Trpa1−/− mice. Consistent with a direct, intracellular action, we show that methylglyoxal is significantly more potent as a TRPA1 agonist when applied to the intracellular face of excised membrane patches than to intact cells. Local intraplantar administration of MG evokes a pain response in Trpa1+/+ but not in Trpa1−/− mice. Furthermore, persistently increased MG levels achieved by two weeks pharmacological inhibition of glyoxalase-1 (GLO-1), the rate-limiting enzyme responsible for detoxification of MG, evokes a progressive and marked thermal (cold and heat) and mechanical hypersensitivity in wildtype but not in Trpa1−/− mice. Our results thus demonstrate that TRPA1 is required both for the acute pain response evoked by topical MG and for the long-lasting pronociceptive effects associated with elevated MG in vivo. In contrast to our observations in DRG neurons, MG evokes indistinguishable [Ca2+]i-responses in pancreatic β-cells cultured from Trpa1+/+ and Trpa1−/− mice. In vivo, the TRPA1 antagonist HC030031 impairs glucose clearance in the glucose tolerance test both in Trpa1+/+ and Trpa1−/− mice, indicating a non-TRPA1 mediated effect and suggesting that results obtained with this compound should be interpreted with caution. Our results show that TRPA1 is the principal target for MG in sensory neurons but not in pancreatic β-cells and that activation of TRPA1 by MG produces a painful neuropathy with the behavioral hallmarks of diabetic neuropathy.
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Grigoreva YS, Glazova MV. [The role of p53 in the regulation of proliferation and differentiation of the neural progenitors in mouse hippocampal organotypic culture]. ROSSIISKII FIZIOLOGICHESKII ZHURNAL IMENI I.M. SECHENOVA 2013; 99:1160-1174. [PMID: 25434228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In the present work we have studied the effects of p53 on the proliferation and differentiation of neural progenitor cells (NPC) in mouse hippocampal organotypic culture. To study the role of p53 the selective p53 inhibitor pifithrin-alpha (PFT) and activator tenovin 1 (TEN) were used in the experiments. Obtained data demonstrated that the injections of PFT did not affect on the amount of phospho-H3 positive cells in the subgranular zone of hippocampus. This data revealed that p53 inhibition does not change the proliferation level of the NPC. In opposite, at the TEN treatments we observed increased of the proliferation activity. Analysis of Pim-1 and Phb 1, which regulate cell cycle progression, demonstrated that p53 activation led to increased level of Pim-1 as well as the proliferation. Thus, our data correlate with published ones and proposed that Pim-1 positively regulates NPC cell cycle progression. In opposite to Pim-1, Phb 1 has anti-proliferative action. Our obtained data demonstrated that TEN diminished Phb 1 expression. Primarily PFT injections led to the increasing Phbl level, but then dramatically decreased it that accompanied with unchanged proliferation level. In other words, increased proliferation level after TEN treatments, which we observed, can be partly depend from the inhibition of anti-proliferative activity of Phb. In our study we demonstrated that both TEN and in a greater degree PFT stimulates neuronal differentiation by activation of CRMP-2 expression, but do not affect on gliogenesis. Thus, obtained data revealed that p53 is an important factor of neuronal differentiation and, probably, p53 action is mediated by cell cycle regulator protein such as Pim-1 and Phbl.
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Lavin MF. Generating SM(a)RTer compounds for translation termination suppression in A-T and other genetic disorders. Mol Ther 2013; 21:1650-2. [PMID: 24008619 PMCID: PMC3776641 DOI: 10.1038/mt.2013.177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Abstract
Urinary incontinence, the involuntary leakage of urine, can result from abnormalities of the urinary tract or may be caused by other conditions and is sub-divided into a number of classifications including stress incontinence and urge urinary incontinence.(1) Urge urinary incontinence (UUI) is involuntary urine leakage accompanied by urgency of micturition.(2) Overactive bladder (OAB) syndrome is defined as urgency occurring with or without UUI and usually occurs with frequency and nocturia.(1) Wet OAB is associated with UUI, while dry OAB is not associated with incontinence. Current drug therapy for OAB involves the use of an antimuscarinic drug, of which there are a number available, such as oxybutynin, darifenacin, solifenacin and tolterodine.(1,3) ▾Mirabegron is the first of a new class of drug, beta-3-adrenoreceptor agonists, licensed for symptomatic treatment of urgency, increased micturition frequency and/or urgency incontinence as may occur in adult patients with OAB syndrome.(4) Here we review the evidence for mirabegron.
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Kamakura T, Ishida Y, Nakamura Y, Yamada T, Kitahara T, Takimoto Y, Horii A, Uno A, Imai T, Okazaki S, Inohara H, Shimada S. Functional expression of TRPV1 and TRPA1 in rat vestibular ganglia. Neurosci Lett 2013; 552:92-7. [PMID: 23916509 DOI: 10.1016/j.neulet.2013.07.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 06/15/2013] [Accepted: 07/15/2013] [Indexed: 11/18/2022]
Abstract
Both TRPV1 and TRPA1 are non-selective cation channels. They are co-expressed, and interact in sensory neurons such as dorsal root ganglia (DRG) and trigeminal ganglia (TG), and are involved in nociception, being activated by nociceptive stimuli. Immunohistological localization of TRPV1 in vestibular ganglion (VG) neurons has been reported. Although TRPA1 is co-expressed with TRPV1 in DRG and TG neurons, it is unclear whether TRPA1 channels are expressed in VG neurons. Moreover, it is unknown whether TRPV1 and TRPA1 channels are functional in VG neurons. We investigated the expression of TRPV1 and TRPA1 in rat VG neurons by RT-PCR, in situ hybridization, immunohistochemistry, and Ca(2+) imaging experiments. Both TRPV1 and TRPA1 RT-PCR products were amplified from the mRNA of rat VG neurons. In situ hybridization experiments showed TRPV1 and TRPA1 mRNA expression in the majority of VG neurons. Immunohistochemistry experiments confirmed TRPV1 protein expression. In Ca(2+) imaging experiments, capsaicin, a TRPV1 agonist, induced a significant increase in intracellular calcium ion concentration ([Ca(2+)]i) in rat primary cultured VG neurons, which was almost completely blocked by capsazepine, a TRPV1-specific antagonist. Cinnamaldehyde, a TRPA1 agonist, also caused an increase in [Ca(2+)]i, which was completely inhibited by HC030031, a TRPA1-specific antagonist. Moreover, in some VG neurons, a [Ca(2+)]i increase was evoked by both capsaicin and cinnamaldehyde in the same neuron. In summary, our histological and physiological studies reveal that TRPV1 and TRPA1 are expressed in VG neurons. It is suggested that TRPV1 and TRPA1 in VG neurons might participate in vestibular function and/or dysfunction such as vertigo.
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Toischer K, Hartmann N, Wagner S, Fischer TH, Herting J, Danner BC, Sag CM, Hund TJ, Mohler PJ, Belardinelli L, Hasenfuss G, Maier LS, Sossalla S. Role of late sodium current as a potential arrhythmogenic mechanism in the progression of pressure-induced heart disease. J Mol Cell Cardiol 2013; 61:111-22. [PMID: 23570977 PMCID: PMC3720777 DOI: 10.1016/j.yjmcc.2013.03.021] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 03/08/2013] [Accepted: 03/29/2013] [Indexed: 12/19/2022]
Abstract
The aim of the study was to determine the characteristics of the late Na current (INaL) and its arrhythmogenic potential in the progression of pressure-induced heart disease. Transverse aortic constriction (TAC) was used to induce pressure overload in mice. After one week the hearts developed isolated hypertrophy with preserved systolic contractility. In patch-clamp experiments both, INaL and the action potential duration (APD90) were unchanged. In contrast, after five weeks animals developed heart failure with prolonged APDs and slowed INaL decay time which could be normalized by addition of the INaL inhibitor ranolazine (Ran) or by the Ca/calmodulin-dependent protein kinase II (CaMKII) inhibitor AIP. Accordingly the APD90 could be significantly abbreviated by Ran, tetrodotoxin and the CaMKII inhibitor AIP. Isoproterenol increased the number of delayed afterdepolarizations (DAD) in myocytes from failing but not sham hearts. Application of either Ran or AIP prevented the occurrence of DADs. Moreover, the incidence of triggered activity was significantly increased in TAC myocytes and was largely prevented by Ran and AIP. Western blot analyses indicate that increased CaMKII activity and a hyperphosphorylation of the Nav1.5 at the CaMKII phosphorylation site (Ser571) paralleled our functional observations five weeks after TAC surgery. In pressure overload-induced heart failure a CaMKII-dependent augmentation of INaL plays a crucial role in the AP prolongation and generation of cellular arrhythmogenic triggers, which cannot be found in early and still compensated hypertrophy. Inhibition of INaL and CaMKII exerts potent antiarrhythmic effects and might therefore be of potential therapeutic interest. This article is part of a Special Issue entitled "Na(+) Regulation in Cardiac Myocytes".
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Moreno JD, Yang PC, Bankston JR, Grandi E, Bers DM, Kass RS, Clancy CE. Ranolazine for congenital and acquired late INa-linked arrhythmias: in silico pharmacological screening. Circ Res 2013; 113:e50-e61. [PMID: 23897695 DOI: 10.1161/circresaha.113.301971] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
RATIONALE The antianginal ranolazine blocks the human ether-a-go-go-related gene-based current IKr at therapeutic concentrations and causes QT interval prolongation. Thus, ranolazine is contraindicated for patients with preexisting long-QT and those with repolarization abnormalities. However, with its preferential targeting of late INa (INaL), patients with disease resulting from increased INaL from inherited defects (eg, long-QT syndrome type 3 or disease-induced electric remodeling (eg, ischemic heart failure) might be exactly the ones to benefit most from the presumed antiarrhythmic properties of ranolazine. OBJECTIVE We developed a computational model to predict if therapeutic effects of pharmacological targeting of INaL by ranolazine prevailed over the off-target block of IKr in the setting of inherited long-QT syndrome type 3 and heart failure. METHODS AND RESULTS We developed computational models describing the kinetics and the interaction of ranolazine with cardiac Na(+) channels in the setting of normal physiology, long-QT syndrome type 3-linked ΔKPQ mutation, and heart failure. We then simulated clinically relevant concentrations of ranolazine and predicted the combined effects of Na(+) channel and IKr blockade by both the parent compound ranolazine and its active metabolites, which have shown potent blocking effects in the therapeutically relevant range. Our simulations suggest that ranolazine is effective at normalizing arrhythmia triggers in bradycardia-dependent arrhythmias in long-QT syndrome type 3 as well tachyarrhythmogenic triggers arising from heart failure-induced remodeling. CONCLUSIONS Our model predictions suggest that acute targeting of INaL with ranolazine may be an effective therapeutic strategy in diverse arrhythmia-provoking situations that arise from a common pathway of increased pathological INaL.
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Wu Y, You H, Ma P, Li L, Yuan Y, Li J, Ye X, Liu X, Yao H, Chen R, Lai K, Yang X. Role of transient receptor potential ion channels and evoked levels of neuropeptides in a formaldehyde-induced model of asthma in BALB/c mice. PLoS One 2013; 8:e62827. [PMID: 23671638 PMCID: PMC3650028 DOI: 10.1371/journal.pone.0062827] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 03/26/2013] [Indexed: 01/09/2023] Open
Abstract
OBJECTIVE Asthma is a complex pulmonary inflammatory disease characterized by the hyper-responsiveness, remodeling and inflammation of airways. Formaldehyde is a common indoor air pollutant that can cause asthma in people experiencing long-term exposure. The irritant effect and adjuvant effect are the two possible pathways of formaldehyde promoted asthma. METHODOLOGY/PRINCIPAL FINDINGS To explore the neural mechanisms and adjuvant effect of formaldehyde, 48 Balb/c mice in six experimental groups were exposed to (a) vehicle control; (b) ovalbumin; (c) formaldehyde (3.0 mg/m(3)); (d) ovalbumin+formaldehyde (3.0 mg/m(3)); (e) ovalbumin+formaldehyde (3.0 mg/m(3))+HC-030031 (transient receptor potential ankyrin 1 antagonist); (f) ovalbumin+formaldehyde (3.0 mg/m(3))+ capsazepine (transient receptor potential vanilloid 1 antagonist). Experiments were conducted after 4 weeks of combined exposure and 1-week challenge with aerosolized ovalbumin. Airway hyper-responsiveness, pulmonary tissue damage, eosinophil infiltration, and increased levels of interleukin-4, interleukin-6, interleukin-1β, immunoglobulin E, substance P and calcitonin gene-related peptide in lung tissues were found in the ovalbumin+formaldehyde (3.0 mg/m(3)) group compared with the values seen in ovalbumin -only immunized mice. Except for interleukin-1β levels, other changes in the levels of biomarker could be inhibited by HC-030031 and capsazepine. CONCLUSIONS/SIGNIFICANCE Formaldehyde might be a key risk factor for the rise in asthma cases. Transient receptor potential ion channels and neuropeptides have important roles in formaldehyde promoted-asthma.
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Than JYXL, Li L, Hasan R, Zhang X. Excitation and modulation of TRPA1, TRPV1, and TRPM8 channel-expressing sensory neurons by the pruritogen chloroquine. J Biol Chem 2013; 288:12818-27. [PMID: 23508958 PMCID: PMC3642326 DOI: 10.1074/jbc.m113.450072] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 03/17/2013] [Indexed: 01/12/2023] Open
Abstract
The sensations of pain, itch, and cold often interact with each other. Pain inhibits itch, whereas cold inhibits both pain and itch. TRPV1 and TRPA1 channels transduce pain and itch, whereas TRPM8 transduces cold. The pruritogen chloroquine (CQ) was reported to excite TRPA1, leading to the sensation of itch. It is unclear how CQ excites and modulates TRPA1(+), TRPV1(+), and TRPM8(+) neurons and thus affects the sensations of pain, itch, and cold. Here, we show that only 43% of CQ-excited dorsal root ganglion neurons expressed TRPA1; as expected, the responses of these neurons were completely prevented by the TRPA1 antagonist HC-030031. The remaining 57% of CQ-excited neurons did not express TRPA1, and excitation was not prevented by either a TRPA1 or TRPV1 antagonist but was prevented by the general transient receptor potential canonical (TRPC) channel blocker BTP2 and the selective TRPC3 inhibitor Pyr3. Furthermore, CQ caused potent sensitization of TRPV1 in 51.9% of TRPV1(+) neurons and concomitant inhibition of TRPM8 in 48.8% of TRPM8(+) dorsal root ganglion neurons. Sensitization of TRPV1 is caused mainly by activation of the phospholipase C-PKC pathway following activation of the CQ receptor MrgprA3. By contrast, inhibition of TRPM8 is caused by a direct action of activated Gαq independent of the phospholipase C pathway. Our data suggest the involvement of the TRPC3 channel acting together with TRPA1 to mediate CQ-induced itch. CQ not only elicits itch by directly exciting itch-encoding neurons but also exerts previously unappreciated widespread actions on pain-, itch-, and cold-sensing neurons, leading to enhanced pain and itch.
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Lu J, Xin S, Meng H, Veldman M, Schoenfeld D, Che C, Yan R, Zhong H, Li S, Lin S. A novel anti-tumor inhibitor identified by virtual screen with PLK1 structure and zebrafish assay. PLoS One 2013; 8:e53317. [PMID: 23658603 PMCID: PMC3637257 DOI: 10.1371/journal.pone.0053317] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 11/30/2012] [Indexed: 11/19/2022] Open
Abstract
Polo-like kinase 1 (PLK1), one of the key regulators of mitosis, is a target for cancer therapy due to its abnormally high activity in several tumors. Plk1 is highly conserved and shares a nearly identical 3-D structure between zebrafish and humans. The initial 10 mitoses of zebrafish embryonic cleavages occur every∼30 minutes, and therefore provide a rapid assay to evaluate mitosis inhibitors including those targeting Plk1. To increase efficiency and specificity, we first performed a computational virtual screen of∼60000 compounds against the human Plk1 3-D structure docked to both its kinase and Polo box domain. 370 candidates with the top free-energy scores were subjected to zebrafish assay and 3 were shown to inhibit cell division. Compared to general screen for compounds inhibiting zebrafish embryonic cleavage, computation increased the efficiency by 11 folds. One of the 3 compounds, named I2, was further demonstrated to effectively inhibit multiple tumor cell proliferation in vitro and PC3 prostate cancer growth in Xenograft mouse model in vivo. Furthermore, I2 inhibited Plk1 enzyme activity in a dose dependent manner. The IC50 values of I2 in these assays are compatible to those of ON-01910, a Plk1 inhibitor currently in Phase III clinic trials. Our studies demonstrate that zebrafish assays coupled with computational screening significantly improves the efficiency of identifying specific regulators of biological targets. The PLK1 inhibitor I2, and its analogs, may have potential in cancer therapeutics.
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Hussar DA. New drug update: 2012. THE CONSULTANT PHARMACIST : THE JOURNAL OF THE AMERICAN SOCIETY OF CONSULTANT PHARMACISTS 2013; 28:210-218. [PMID: 23552702 DOI: 10.4140/tcp.n.2013.210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Five new drugs that are used for medical problems often experienced by the elderly have been selected for consideration in this review. The uses and most important properties of these agents are considered, and a rating for each new drug is determined. The rating is based on a comparison of the new drug with related drugs already marketed. Advantages, disadvantages, and other important information regarding the new drug are identified and used as the basis for determining the rating.
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Trevisan G, Materazzi S, Fusi C, Altomare A, Aldini G, Lodovici M, Patacchini R, Geppetti P, Nassini R. Novel therapeutic strategy to prevent chemotherapy-induced persistent sensory neuropathy by TRPA1 blockade. Cancer Res 2013; 73:3120-31. [PMID: 23477783 DOI: 10.1158/0008-5472.can-12-4370] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) is a severe and painful adverse reaction of cancer treatment in patients that is little understood or treated. Cytotoxic drugs that cause CIPN exert their effects by increasing oxidative stress, which activates the ion channel TRPA1 expressed by nociceptors. In this study, we evaluated whether TRPA1 acted as a critical mediator of CIPN by bortezomib or oxaliplatin in a mouse model system. Bortezomib evoked a prolonged mechanical, cold, and selective chemical hypersensitivity (the latter against the TRPA1 agonist allyl isothiocyanate). This CIPN hypersensitivity phenotype that was stably established by bortezomib could be transiently reverted by systemic or local treatment with the TRPA1 antagonist HC-030031. A similar effect was produced by the oxidative stress scavenger α-lipoic acid. Notably, the CIPN phenotype was abolished completely in mice that were genetically deficient in TRPA1, highlighting its essential role. Administration of bortezomib or oxaliplatin, which also elicits TRPA1-dependent hypersensitivity, produced a rapid, transient increase in plasma of carboxy-methyl-lysine, a by-product of oxidative stress. Short-term systemic treatment with either HC-030031 or α-lipoic acid could completely prevent hypersensitivity if administered before the cytotoxic drug. Our findings highlight a key role for early activation/sensitization of TRPA1 by oxidative stress by-products in producing CIPN. Furthermore, they suggest prevention strategies for CIPN in patients through the use of early, short-term treatments with TRPA1 antagonists.
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93
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Xie C, Ma L, Liu J, Li X, Pei H, Xiang M, Chen L. SKLB023 blocks joint inflammation and cartilage destruction in arthritis models via suppression of nuclear factor-kappa B activation in macrophage. PLoS One 2013; 8:e56349. [PMID: 23431370 PMCID: PMC3576337 DOI: 10.1371/journal.pone.0056349] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 01/08/2013] [Indexed: 12/15/2022] Open
Abstract
Rheumatoid arthritis (RA) is the most common arthritis and is mainly characterized by symmetric polyarticular joint disorders. Our previous study demonstrated a novel small molecule compound (Z)-N-(3-Chlorophenyl)-2-(4-((2,4-dioxothiazolidin-5-ylidene) methyl) phenoxy) acet-amide (SKLB023) showed potently anti-arthritic effects in a rat arthritis model, however, the underlying mechanisms for this are largely unknown. Both NF-κB and macrophages were reported to play important roles in the pathologic processes of RA. The purposes of this study were to indicate whether NF-κB and macrophages contributed to anti-arthritic effects of SKLB023 in two experimental arthritis models. Our results showed that SKLB023 could significantly improve joint inflammation and cartilage destruction both in adjuvant induced arthritis (AIA) and collagen-induced arthritis (CIA) models. We further found that the binding activation of NF-κB to DNA in joint tissues and RAW264.7 macrophages were suppressed by SKLB023. SKLB023 also inhibited the NF-κB activity in peritoneal macrophages by luciferase assay. Furthermore, the number of macrophages in synovial tissues was decreased after the treatment of different doses of SKLB023. The levels of TNF-α, IL-1β, and IL-6 in plasma, and the levels of TNF-α, NO, and IL-1β in peritoneal macrophages were down-regulated by SKLB023. Finally, SKLB023 attenuated the expression of iNOS and COX-2 in vivo and suppressed the phosphorylations of components of the mitogen-activated protein kinases (MAPKs). These observations identify a novel function for SKLB023 as an inhibitor of NF-κB in macrophages of RA, highlighting that SKLB023 was a potential therapeutic strategy for RA.
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MESH Headings
- Acetanilides/pharmacology
- Acetanilides/therapeutic use
- Animals
- Ankle Joint/drug effects
- Ankle Joint/immunology
- Ankle Joint/pathology
- Anti-Inflammatory Agents/pharmacology
- Anti-Inflammatory Agents/therapeutic use
- Arthritis, Rheumatoid/drug therapy
- Arthritis, Rheumatoid/immunology
- Arthritis, Rheumatoid/metabolism
- Cartilage, Articular/drug effects
- Cartilage, Articular/immunology
- Cartilage, Articular/pathology
- Cell Line
- Cyclooxygenase 2/metabolism
- Cytokines/blood
- Disease Models, Animal
- Female
- Inflammation Mediators/blood
- Lipopolysaccharides/pharmacology
- Macrophages/drug effects
- Macrophages/immunology
- Macrophages/metabolism
- Male
- Mice
- Mice, Inbred DBA
- Mitogen-Activated Protein Kinases/metabolism
- NF-kappa B/metabolism
- Nitric Oxide Synthase Type II/metabolism
- Phosphorylation
- Protein Processing, Post-Translational
- Rats
- Rats, Inbred Lew
- Signal Transduction/drug effects
- Thiazolidinediones/pharmacology
- Thiazolidinediones/therapeutic use
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94
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Abstract
Ranolazine is currently approved for use in chronic angina. The basis for this use is likely related to inhibition of late sodium channels with resultant beneficial downstream effects. Randomized clinical trials have demonstrated an improvement in exercise capacity and reduction in angina episodes with ranolazine. This therapeutic benefit occurs without the hemodynamic effects seen with the conventional antianginal agents. The inhibition of late sodium channels as well as other ion currents has a central role in the potential use of ranolazine in ischemic heart disease, arrhythmias, and heart failure. Despite its QTc-prolonging action, albeit minimal, clinical data have not shown a predisposition to torsades de pointes, and the medication has shown a reasonable safety profile even in those with structural heart disease. In this article we present the experimental and clinical data that support its current therapeutic role, and provide insight into potential future clinical applications.
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95
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Yen JH, Wang YS, Hsu WS, Chen WC. Phylogenetic changes in soil microbial and diazotrophic diversity with application of butachlor. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2013; 48:49-56. [PMID: 23030440 DOI: 10.1080/03601234.2012.716729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We investigated changes in population and taxonomic distribution of cultivable bacteria and diazotrophs with butachlor application in rice paddy soils. Population changes were measured by the traditional plate-count method, and taxonomic distribution was studied by 16S rDNA sequencing, then maximum parsimony phylogenic analysis with bootstrapping (1,000 replications). The bacterial population was higher after 39 than 7 days of rice cultivation, which indicated the augmentation of soil microbes by rice root exudates. The application of butachlor increased the diazotrophic population in both upper (0-3 cm) and lower (3-15 cm) layers of soils. Especially at day 39, the population of diazotrophs was 1.8 and 1.6 times that of the control in upper and lower layer soils, respectively. We found several bacterial strains only with butachlor application; examples are strains closest to Bacillus arsenicus, B. marisflavi, B. luciferensis, B. pumilus, and Pseudomonas alvei. Among diazotrophs, three strains closely related to Streptomyces sp. or Rhrizobium sp. were found only with butachlor application. The population of cultivable bacteria and the species composition were both changed with butachlor application, which explains in part the contribution of butachlor to augmenting soil nitrogen-fixing ability.
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96
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Hood B, Andersson KE. Common theme for drugs effective in overactive bladder treatment: inhibition of afferent signaling from the bladder. Int J Urol 2013; 20:21-7. [PMID: 23072271 PMCID: PMC3558796 DOI: 10.1111/j.1442-2042.2012.03196.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 09/19/2012] [Indexed: 12/21/2022]
Abstract
The overactive bladder syndrome and detrusor overactivity are conditions that can have major effects on quality of life and social functioning. Antimuscarinic drugs are still first-line treatment. These drugs often have good initial response rates, but adverse effects and decreasing efficacy cause long-term compliance problems, and alternatives are needed. The recognition of the functional contribution of the urothelium/suburothelium, the autonomous detrusor muscle activity during bladder filling and the diversity of nerve transmitters involved has sparked interest in both peripheral and central modulation of overactive bladder syndrome/detrusor overactivity pathophysiology. Three drugs recently approved for treatment of overactive bladder syndrome/detrusor overactivity (mirabegron, tadalafil and onabotulinum toxin A), representing different pharmacological mechanisms; that is, β-adrenoceptor agonism, phosphodiesterase type 5 inhibition, and inhibition of nerve release of efferent and afferent transmitters, all seem to have one effect in common: inhibition of the afferent nervous activity generated by the bladder during filling. In the present review, the different mechanisms forming the pharmacological basis for the use of these drugs are discussed.
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97
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Belavic JM. Mirabegron for overactive bladder. Nurse Pract 2012; 37:9-10. [PMID: 23165131 DOI: 10.1097/01.npr.0000422213.00175.5d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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98
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Lamendola P, Nerla R, Pitocco D, Villano A, Scavone G, Stazi A, Russo G, Di Franco A, Sestito A, Ghirlanda G, Lanza GA, Crea F. Effect of ranolazine on arterial endothelial function in patients with type 2 diabetes mellitus. Atherosclerosis 2012; 226:157-60. [PMID: 23146293 DOI: 10.1016/j.atherosclerosis.2012.10.051] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 10/16/2012] [Accepted: 10/22/2012] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To assess the effect of ranolazine on systemic vascular function in patients with type II diabetes mellitus (T2DM). METHODS We randomized 30 consecutive T2DM patients with no evidence of cardiovascular disease and no insulin therapy to receive one of the following 3 forms of treatment in a blinded fashion: ranolazine, 375 mg bid for 3 weeks (group 1); ranolazine, 375 mg bid for 2 weeks, followed by placebo bid for 1 week (group 2); placebo bid for 3 weeks (group 3). Flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) of the right brachial artery were assessed at baseline and after 48 h, and 2 and 3 weeks. RESULTS FMD and NMD were similar among groups at baseline. Compared to the basal value, FMD significantly improved after 2 weeks in group 1 and in group 2 (p < 0.01 for both), but not in group 3. At 3 weeks, FMD remained improved, compared to baseline, in group 1 (p < 0.05), whereas returned to basal values in group 2 (p = 0.89 vs. baseline). No changes in NMD were observed in any group. CONCLUSIONS In this controlled study, ranolazine was able to improve endothelial function in T2DM patients.
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100
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Aizawa N, Homma Y, Igawa Y. Effects of mirabegron, a novel β3-adrenoceptor agonist, on primary bladder afferent activity and bladder microcontractions in rats compared with the effects of oxybutynin. Eur Urol 2012; 62:1165-73. [PMID: 22981677 DOI: 10.1016/j.eururo.2012.08.056] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 08/27/2012] [Indexed: 01/15/2023]
Abstract
BACKGROUND Mirabegron is the first β3-adrenoceptor agonist that is clinically effective for overactive bladder. OBJECTIVE The effects of mirabegron on primary bladder mechanosensitive single-unit afferent activities (SAAs) and bladder microcontractions were evaluated and compared with the effects of oxybutynin. DESIGN, SETTING, AND PARTICIPANTS Female Sprague-Dawley rats were anesthetized. The SAAs generated from left L6 dorsal roots were identified by electrical stimulation of the left pelvic nerve and bladder distension. Nerves with conduction velocities (CVs) >2.5 m/s were designated as Aδ-fibers, and nerves with CVs<2.5 m/s were designated as C-fibers. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Two measurements were performed in separate animals. First, after measuring the baselines of SAA during constant filling cystometry, the procedure was repeated with each intravenous administration of mirabegron at three doses-0.1, 0.3, and 1.0mg/kg-cumulatively. Second, the bladder was filled with saline until the intravesical pressure reached 30 cm H(2)O and was kept under an isovolumetric condition; then the recording was performed for 5 min with vehicle and mirabegron or oxybutynin administrated intravenously. RESULTS AND LIMITATIONS A total of 74 single-unit afferent fibers were isolated from 55 rats (Aδ-fibers: n=34; C-fibers: n=40). SAAs of both Aδ-fibers and C-fibers in response to bladder filling significantly decreased after mirabegron administration in a dose-dependent manner, which was more remarkable for Aδ-fibers. During an isovolumetric condition of the bladder, the mean bladder pressure and the number of microcontractions decreased after mirabegron administration, whereas these parameters did not change with oxybutynin administration. SAAs of Aδ-fibers were significantly decreased by mirabegron administration at both 0.3 and 1mg/kg, whereas SAAs of C-fibers decreased only at 1mg/kg. In contrast, oxybutynin (1mg/kg) did not alter either type of SAA. CONCLUSIONS The present study demonstrates that mirabegron can inhibit mechanosensitive bladder afferent activity, especially of Aδ-fibers, which may be related to suppression of bladder microcontractions.
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