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1.
J Pharmacol Sci ; 155(3): 113-120, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38797535

RESUMO

Reactive sulfur species including sulfides, polysulfides and cysteine hydropersulfide play extensive roles in health and disease, which involve modification of protein functions through the interaction with metals bound to the proteins, cleavage of cysteine disulfide (S-S) bonds and S-persulfidation of cysteine residues. Sulfides over a wide micromolar concentration range enhance the activity of Cav3.2 T-type Ca2+ channels by eliminating Zn2+ bound to the channels, thereby promoting somatic and visceral pain. Cav3.2 is under inhibition by Zn2+ in physiological conditions, so that sulfides function to reboot Cav3.2 from Zn2+ inhibition and increase the excitability of nociceptors. On the other hand, polysulfides generated from sulfides activate TRPA1 channels via cysteine S-persulfidation, thereby facilitating somatic, but not visceral, pain. Thus, Cav3.2 function enhancement by sulfides and TRPA1 activation by polysulfides, synergistically accelerate somatic pain signals. The increased activity of the sulfide/Cav3.2 system, in particular, appears to have a great impact on pathological pain, and may thus serve as a therapeutic target for treatment of neuropathic and inflammatory pain including visceral pain.


Assuntos
Canais de Cálcio Tipo T , Sulfetos , Canal de Cátion TRPA1 , Sulfetos/farmacologia , Canal de Cátion TRPA1/metabolismo , Humanos , Canais de Cálcio Tipo T/metabolismo , Canais de Cálcio Tipo T/fisiologia , Animais , Zinco/metabolismo , Dor/metabolismo , Dor/tratamento farmacológico , Nociceptores/metabolismo , Nociceptores/efeitos dos fármacos
2.
Biochem Biophys Res Commun ; 639: 142-149, 2023 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-36493557

RESUMO

Irregular regeneration or inappropriate remodeling of the axons of the primary afferent neurons after peripheral nerve trauma could be associated with the development of neuropathic pain. We analyzed the molecular mechanisms for the neuritogenesis and neurite outgrowth caused by prostaglandin E2 (PGE2) in mouse dorsal root ganglion (DRG) neurons, and evaluated their opioid modulation. PGE2 in combination with IBMX, a phosphodiesterase inhibitor, caused neuritogenesis/neurite outgrowth in DRG cells, an effect abolished by a prostanoid EP4, but not EP2, receptor antagonist, and inhibitors of adenylyl cyclase or protein kinase A (PKA). Blockers of T-type Ca2+ channels (T-channels), that are responsible for window currents involving the sustained low-level Ca2+ entry at voltages near the resting membrane potentials and can be functionally upregulated by PKA, inhibited the neuritogenesis/neurite outgrowth caused by PGE2/IBMX or dibutylyl cyclic AMP, a PKA activator, in DRG neurons, an inhibitory effect mimicked by ZnCl2 and ascorbic acid that block Cav3.2, but not Cav3.1 or Cav3.3, T-channels. Morphine and DAMGO, µ-opioid receptor (MOR) agonists, suppressed the neuritogenesis and/or neurite outgrowth induced by PGE2/IBMX in DRG neurons and also DRG neuron-like ND7/23 cells, an effect reversed by naloxone or ß-funaltrexamine, a selective MOR antagonist. Our data suggest that the EP4 receptor/PKA/Cav3.2 pathway is involved in the PGE2-induced neuritogenesis/neurite outgrowth in DRG neurons, which can be suppressed by MOR stimulation. We propose that MOR agonists including morphine in the early phase after peripheral nerve trauma might delay the axonal regeneration of the primary afferent neurons but prevent the development of neuropathic pain.


Assuntos
Analgésicos Opioides , Neuralgia , Animais , Camundongos , 1-Metil-3-Isobutilxantina/farmacologia , Analgésicos Opioides/farmacologia , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Dinoprostona/metabolismo , Gânglios Espinais/metabolismo , Morfina/farmacologia , Neuralgia/metabolismo , Crescimento Neuronal , Neurônios/metabolismo , Ratos Sprague-Dawley , Receptores de Prostaglandina E Subtipo EP2 , Ratos
3.
J Pharmacol Sci ; 152(2): 86-89, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37169483

RESUMO

Cav3.2, a T-type calcium channel (T-channel) family member, is expressed in the nociceptors and spinal cord, and its activity is largely suppressed by zinc under physiological conditions. In rats, intrathecal and intraplantar administration of a zinc chelator, TPEN, caused T-channel-dependent mechanical hyperalgesia, and the intraplantar, but not intrathecal, TPEN induced Cav3.2 upregulation in the dorsal root ganglion. In mice, intraplantar TPEN also caused mechanical allodynia, which was abolished by T-channel inhibitors or Cav3.2 gene deletion. Together, spinal and peripheral zinc deficiency appears to enhance Cav3.2 activity in the spinal postsynaptic neurons and nociceptors, respectively, thereby promoting pain.


Assuntos
Canais de Cálcio Tipo T , Hiperalgesia , Ratos , Camundongos , Animais , Hiperalgesia/induzido quimicamente , Roedores , Quelantes , Zinco , Canais de Cálcio Tipo T/genética , Gânglios Espinais
4.
Biol Pharm Bull ; 46(9): 1343-1346, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37661413

RESUMO

Cav3.2 channels belong to the T-type calcium channel (T-channel) family, i.e., low voltage-activated calcium channels, and are abundantly expressed in the nociceptors, playing a principal role in the development of pathological pain. The channel activity of Cav3.2 is suppressed by zinc under physiological conditions. We thus tested whether dietary zinc deficiency would cause Cav3.2-dependent nociceptive hypersensitivity in mice. In the mice fed with zinc deficient diet for 2 weeks, plasma zinc levels declined by more than half, and mechanical allodynia developed. The dietary zinc deficiency-induced allodynia was restored by T-channel inhibitors or by Cav3.2 gene silencing. These data demonstrate that zinc deficiency induces Cav3.2-dependent nociceptive hypersensitivity in mice, thereby suggesting that pain experienced by patients with diseases accompanied by zinc deficiency (e.g., chronic kidney disease) might involve the increased Cav3.2 activity.


Assuntos
Canais de Cálcio Tipo T , Hipersensibilidade , Desnutrição , Animais , Camundongos , Nociceptividade , Zinco , Hiperalgesia/etiologia , Dor
5.
J Pharmacol Sci ; 148(1): 156-161, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34924121

RESUMO

We examined the role of ATP and high mobility group box 1 (HMGB1) in paclitaxel-induced peripheral neuropathy (PIPN). PIPN in mice was prevented by HMGB1 neutralization, macrophage depletion, and P2X7 or P2X4 blockade. Paclitaxel and ATP synergistically released HMGB1 from macrophage-like RAW264.7 cells, but not neuron-like NG108-15 cells. The paclitaxel-induced HMGB1 release from RAW264.7 cells was accelerated by co-culture with NG108-15 cells in a manner dependent on P2X7 or P2X4. Paclitaxel released ATP from NG108-15 cells, but not RAW264.7 cells. Thus, PIPN is considered to involve acceleration of HMGB1 release from macrophages through P2X7 and P2X4 activation by neuron-derived ATP.


Assuntos
Trifosfato de Adenosina/fisiologia , Proteína HMGB1/metabolismo , Macrófagos/metabolismo , Neurônios/metabolismo , Paclitaxel/efeitos adversos , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/metabolismo , Animais , Masculino , Camundongos , Camundongos Endogâmicos , Doenças do Sistema Nervoso Periférico/imunologia , Doenças do Sistema Nervoso Periférico/prevenção & controle , Células RAW 264.7 , Receptor Cross-Talk/imunologia , Receptores Purinérgicos P2X4/metabolismo , Receptores Purinérgicos P2X7/metabolismo
6.
J Pharmacol Sci ; 148(3): 315-325, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35177211

RESUMO

Oxaliplatin often induces peripheral neuropathy, a dose-limiting adverse reaction, and in rare cases leads to sinusoidal obstruction syndrome. We thus conducted a retrospective cohort study to examine the relationship between oxaliplatin-induced peripheral neuropathy (OIPN) and hepatic impairment, and then perform a fundamental study to analyze the underlying mechanisms. Analysis of medical records in cancer patients treated with oxaliplatin indicated that laboratory test parameters of hepatic impairment including AST, ALT and APRI (AST to platelet ratio index) moderately increased during oxaliplatin treatment, which was positively correlated with the severity of OIPN (grades 1-4), and associated with later incidence of survivors with OIPN grades ≥2. In mice, hepatic injury induced by CCl4 or ethanol accelerated OIPN in mice, an effect prevented by inactivation of high mobility group box 1 (HMGB1), known to participate in OIPN, by the neutralizing antibody or thrombomodulin alfa capable of promoting its thrombin-dependent degradation. Oxaliplatin also aggravated the hepatic injury in mice. CCl4 released HMGB1 from cultured hepatic parenchymal cells, and oxaliplatin at clinically achievable concentrations released HMGB1 from hepatic parenchymal and non-parenchymal cells. Our clinical and preclinical data suggest that the development of mild hepatic impairment during oxaliplatin treatment is associated with later aggravation of OIPN.


Assuntos
Antineoplásicos/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Oxaliplatina/efeitos adversos , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Células Cultivadas , Progressão da Doença , Feminino , Proteína HMGB1/metabolismo , Humanos , Masculino , Camundongos Endogâmicos , Pessoa de Meia-Idade , Doenças do Sistema Nervoso Periférico/genética , Estudos Retrospectivos , Índice de Gravidade de Doença
7.
J Pharmacol Sci ; 146(1): 49-57, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33858655

RESUMO

We performed clinical retrospective study in female cancer patients and fundamental experiments in mice, in order to clarify risk factors for paclitaxel-induced peripheral neuropathy (PIPN). In the clinical study, 131 of 189 female outpatients with cancer undergoing paclitaxel-based chemotherapy met inclusion criteria. Breast cancer survivors (n = 40) showed significantly higher overall PIPN (grades 1-4) incidence than non-breast cancer survivors (n = 91). Multivariate sub-analyses of breast cancer survivors showed that 57 years of age or older and endocrine therapy before paclitaxel treatment were significantly associated with severe PIPN (grades 2-4). The age limit was also significantly correlated with overall development of severe PIPN. In the preclinical study, female mice subjected to ovariectomy received repeated administration of paclitaxel, and mechanical nociceptive threshold was assessed by von Frey test. Ovariectomy aggravated PIPN in the mice, an effect prevented by repeated treatment with 17ß-estradiol. Repeated administration of thrombomodulin alfa (TMα), known to prevent chemotherapy-induced peripheral neuropathy in rats and mice, also prevented the development of PIPN in the ovariectomized mice. Collectively, breast cancer survivors, particularly with postmenopausal estrogen decline and/or undergoing endocrine therapy, are considered a PIPN-prone subpopulation, and may require non-hormonal pharmacological intervention for PIPN in which TMα may serve as a major candidate.


Assuntos
Antineoplásicos Fitogênicos/efeitos adversos , Estrogênios/deficiência , Estrogênios/fisiologia , Paclitaxel/efeitos adversos , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Animais , Neoplasias da Mama , Sobreviventes de Câncer , Feminino , Humanos , Camundongos , Camundongos Endogâmicos , Pessoa de Meia-Idade , Ovariectomia/efeitos adversos , Doenças do Sistema Nervoso Periférico/prevenção & controle , Pós-Menopausa , Ratos , Estudos Retrospectivos , Fatores de Risco , Trombomodulina/administração & dosagem
8.
Biol Pharm Bull ; 44(3): 461-464, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33642557

RESUMO

T-Type Ca2+ channels (T-channels), particularly Cav3.2, are now considered as therapeutic targets for treatment of intractable pain including visceral pain. Among existing medicines, bepridil, a multi-channel blocker, used for treatment of arrhythmia and angina, and pimozide, a dopamine D2 receptor antagonist, known as a typical antipsychotic, have potent T-channel blocking activity. We thus tested whether bepridil and pimozide could suppress visceral pain in mice. Colonic and bladder pain were induced by intracolonic administration of 2,4,6-trinitrobenzene sulfonic acid (TNBS) and systemic administration of cyclophosphamide (CPA), respectively. Referred hyperalgesia was assessed by von Frey test, and colonic hypersensitivity to distension by a volume load with intracolonic water injection and spontaneous bladder pain were evaluated by observing nociceptive behaviors in conscious mice. The mice exhibited referred hyperalgesia and colonic hypersensitivity to distension on day 6 after TNBS treatment. Systemic administration of bepridil at 10-20 mg/kg or pimozide at 0.1-0.5 mg/kg strongly reduced the referred hyperalgesia on the TNBS-induced referred hyperalgesia and colonic hypersensitivity to distension. CPA treatment caused bladder pain-like nociceptive behavior and referred hyperalgesia, which were reversed by bepridil at 10-20 mg/kg or pimozide at 0.5-1 mg/kg. Our data thus suggest that bepridil and pimozide, existing medicines capable of blocking T-channels, are useful for treatment of colonic and bladder pain, and serve as seeds for the development of new medicines for visceral pain treatment.


Assuntos
Analgésicos/uso terapêutico , Bepridil/uso terapêutico , Bloqueadores dos Canais de Cálcio/uso terapêutico , Colite/tratamento farmacológico , Cistite/tratamento farmacológico , Antagonistas dos Receptores de Dopamina D2/uso terapêutico , Pimozida/uso terapêutico , Dor Visceral/tratamento farmacológico , Animais , Canais de Cálcio Tipo T , Colite/induzido quimicamente , Ciclofosfamida , Cistite/induzido quimicamente , Feminino , Masculino , Camundongos , Ácido Trinitrobenzenossulfônico , Dor Visceral/induzido quimicamente
9.
J Pharmacol Sci ; 143(1): 60-63, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32151541

RESUMO

TRPV1 is phosphorylated and functionally upregulated by protein kinases, and negatively regulated by phosphatases including calcineurin. Since the clinical use of calcineurin-inhibiting immunosuppressants is commonly associated with chronic diarrhea, we examined if tacrolimus, a calcineurin inhibitor, promotes TRPV1-dependent colonic hypersensitivity in mice. Intracolonic administration of capsaicin, a TRPV1 agonist, caused referred hyperalgesia in the lower abdomen, an effect prevented by capsazepine, a TRPV1 blocker. Tacrolimus accelerated the intracolonic capsaicin-induced referred hyperalgesia. Similarly, intracolonic capsaicin caused spinal ERK phosphorylation, a marker for nociceptor excitation, an effect promoted by tacrolimus. Thus, tacrolimus may aggravate TRPV1-related colonic pain accompanying irritable bowel syndrome.


Assuntos
Inibidores de Calcineurina/efeitos adversos , Capsaicina/efeitos adversos , Colo , Hiperalgesia/induzido quimicamente , Imunossupressores/efeitos adversos , Tacrolimo/efeitos adversos , Animais , Hiperalgesia/genética , Síndrome do Intestino Irritável/induzido quimicamente , Camundongos , Canais de Cátion TRPV/agonistas
10.
J Pharmacol Sci ; 143(2): 112-116, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32222337

RESUMO

HMGB1, a nuclear protein, once released to the extracellular space, promotes somatic and visceral pain signals. We thus analyzed the role of HMGB1 in an intravesical substance P-induced bladder pain syndrome (BPS) mouse model. Intravesical administration of substance P caused referred hyperalgesia/allodynia in the lower abdomen and hindpaw without producing severe urothelial damage, which was prevented by an anti-HMGB1-neutralizing antibody, thrombomodulin α capable of inactivating HMGB1 and antagonists of RAGE or CXCR4. The HMGB1 inactivation or RAGE blockade also reversed the established bladder pain symptoms. HMGB1 and RAGE are thus considered to serve as therapeutic targets for BPS.


Assuntos
Anticorpos Neutralizantes/uso terapêutico , Cistite Intersticial/etiologia , Cistite Intersticial/genética , Proteína HMGB1/fisiologia , Receptores Citoplasmáticos e Nucleares , Substância P/efeitos adversos , Trombomodulina/uso terapêutico , Animais , Cistite Intersticial/tratamento farmacológico , Modelos Animais de Doenças , Feminino , Proteína HMGB1/imunologia , Humanos , Masculino , Camundongos Endogâmicos , Terapia de Alvo Molecular , Receptor para Produtos Finais de Glicação Avançada/antagonistas & inibidores , Receptores CXCR4/antagonistas & inibidores , Substância P/administração & dosagem
11.
Biochem Biophys Res Commun ; 511(3): 705-710, 2019 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-30827506

RESUMO

Cav3.2 T-type Ca2+ channels are expressed in the primary afferents and play a pronociceptive role. The activity of Cav3.2 is enhanced by H2S, a gasotransmitter, and suppressed by ascorbic acid (vitamin C) through metal-catalyzed oxidation of the Zn2+-binding His191 in Cav3.2. Since rodents, but not humans, are capable of synthesizing ascorbic acid, the present study examined the role of ascorbic acid in nociceptive processing, using the mice lacking GNL/SMP30, an enzyme essential for ascorbic acid biosynthesis. Intraplantar and intracolonic administration of NaHS, an H2S donor, caused somatic allodynia and referred hyperalgesia, respectively, and repeated treatment with paclitaxel produced neuropathic allodynia in wild-type mice, all of which were suppressed by ascorbic acid or T-type Ca2+ channel blockers. Dietary ascorbic acid restriction caused dramatic decreases in plasma and tissue ascorbic acid levels in GNL/SMP30-knockout, but not wild-type, mice. The ascorbic acid restriction enhanced the somatic and visceral hypersensitivity following intraplantar and intracolonic NaHS, respectively, and paclitaxel-induced neuropathy in GNL/SMP30-knockout mice, while it had no such effect in wild-type mice. Together, our data unveil the critical role of ascorbic acid in regulating somatic and visceral pain sensitivity and support accumulating clinical evidence for the usefulness of ascorbic acid in pain management.


Assuntos
Deficiência de Ácido Ascórbico/metabolismo , Ácido Ascórbico/metabolismo , Proteínas de Ligação ao Cálcio/genética , Hiperalgesia/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Dor Visceral/metabolismo , Animais , Deficiência de Ácido Ascórbico/complicações , Deficiência de Ácido Ascórbico/genética , Canais de Cálcio Tipo T/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Hiperalgesia/etiologia , Hiperalgesia/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Limiar da Dor , Dor Visceral/etiologia , Dor Visceral/genética
12.
J Neuroinflammation ; 16(1): 199, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31666085

RESUMO

BACKGROUND: Macrophage-derived high mobility group box 1 (HMGB1), a damage-associated molecular pattern (DAMP) protein, plays a key role in the development of chemotherapy-induced peripheral neuropathy (CIPN) caused by paclitaxel in rodents. Endothelial thrombomodulin (TM) promotes thrombin-induced degradation of HMGB1, and TMα, a recombinant human soluble TM, abolishes peripheral HMGB1-induced allodynia in mice. We thus examined whether HMGB1, particularly derived from macrophages, contributes to oxaliplatin-induced neuropathy in mice and analyzed the anti-neuropathic activity of the TM/thrombin system. METHODS: CIPN models were created by the administration of oxaliplatin in mice and rats, and the nociceptive threshold was assessed by von Frey test or paw pressure test. Macrophage-like RAW264.7 cells were stimulated with oxaliplatin in vitro. Proteins were detected and/or quantified by Western blotting, immunostaining, or enzyme-linked immunosorbent assay. RESULTS: Intraperitoneal administration of an anti-HMGB1-neutralizing antibody (AB) at 1 mg/kg prevented the oxaliplatin-induced allodynia in mice and rats. Antagonists of Toll-like receptor (TLR) 4, receptor for advanced glycation end products (RAGE) and CXCR4 among the HMGB1-targeted pro-nociceptive receptors, also mimicked the anti-neuropathic activity of AB in mice. Macrophage accumulation in the sciatic nerve was observed in mice treated with paclitaxel, but not oxaliplatin, and neither macrophage depletion nor inhibitors of macrophage activation affected oxaliplatin-induced allodynia. Oxaliplatin was 10- to 100-fold less potent than paclitaxel in releasing HMGB1 from macrophage-like RAW264.7 cells. Like AB, TMα at 10 mg/kg prevented the oxaliplatin-induced allodynia in mice as well as rats, an effect abolished by argatroban at 10 mg/kg, a thrombin inhibitor. The anti-neuropathic activity of TMα in oxaliplatin-treated mice was suppressed by oral anticoagulants such as warfarin at 1 mg/kg, dabigatran at 75 mg/kg, and rivaroxaban at 10 mg/kg, but not antiplatelet agents such as aspirin at 50 mg/kg and clopidogrel at 10 mg/kg. Repeated administration of the anticoagulants gradually developed neuropathic allodynia and elevated plasma HMGB1 levels in mice treated with a subeffective dose of oxaliplatin. CONCLUSIONS: Our data thus suggests a causative role of HMGB1 derived from non-macrophage cells in oxaliplatin-induced peripheral neuropathy and a thrombin-dependent anti-neuropathic activity of exogenous TMα and, most probably, endogenous TM.


Assuntos
Anticoagulantes/administração & dosagem , Proteína HMGB1/metabolismo , Oxaliplatina/toxicidade , Doenças do Sistema Nervoso Periférico/prevenção & controle , Trombina/metabolismo , Trombomodulina/metabolismo , Animais , Anticoagulantes/efeitos adversos , Antineoplásicos/toxicidade , Masculino , Camundongos , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Células RAW 264.7 , Ratos , Ratos Wistar , Roedores
13.
J Pharmacol Sci ; 140(2): 193-196, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31235271

RESUMO

We tested whether NNC 55-0396 (NNC), a T-type calcium channel (T-channel) blocker, reduces the brain injury caused by middle cerebral artery occlusion and reperfusion (MCAO/R) in mice. NNC, administered i.c.v. before the occlusion, greatly reduced the MCAO/R-induced brain infarct and neurological dysfunctions, although it, given toward the end of occlusion, was less effective. Systemic administration of NNC before the occlusion also attenuated the infarct and neurological dysfunctions. Our data imply that blood-brain-barrier-permeable T-channel blockers such as NNC are capable of reducing MCAO/R-induced brain damage, and that T-channels are involved in neuronal damage induced by ischemia rather than reperfusion.


Assuntos
Benzimidazóis/administração & dosagem , Lesões Encefálicas/etiologia , Lesões Encefálicas/prevenção & controle , Bloqueadores dos Canais de Cálcio/administração & dosagem , Ciclopropanos/administração & dosagem , Infarto da Artéria Cerebral Média/complicações , Naftalenos/administração & dosagem , Traumatismo por Reperfusão/complicações , Animais , Benzimidazóis/metabolismo , Barreira Hematoencefálica/metabolismo , Bloqueadores dos Canais de Cálcio/metabolismo , Canais de Cálcio Tipo T/fisiologia , Ciclopropanos/metabolismo , Infusões Intraventriculares , Infusões Parenterais , Masculino , Camundongos Endogâmicos , Naftalenos/metabolismo , Fatores de Tempo
14.
J Pharmacol Sci ; 140(3): 310-312, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31492577

RESUMO

We tested whether genetic deletion of Cav3.2 T-type Ca2+ channels abolishes hydrogen sulfide (H2S)-mediated pain signals in mice. In Cav3.2-expressing HEK293 cells, Na2S, an H2S donor, at 100 µM clearly increased Ba2+ currents, as assessed by whole-cell patch-clamp recordings. In wild-type C57BL/6 mice, intraplantar and intracolonic administration of Na2S evoked mechanical allodynia and visceral nociceptive behavior, respectively, which were abolished by TTA-A2, a T-type Ca2+ channel blocker. In Cav3.2-knockout mice of a C57BL/6 background, Na2S caused neither somatic allodynia nor colonic nociception. Our study thus provides definitive evidence for an essential role of Cav3.2 in H2S-dependent somatic and colonic pain.


Assuntos
Canais de Cálcio Tipo T/genética , Canais de Cálcio Tipo T/metabolismo , Sulfeto de Hidrogênio/farmacologia , Dor Nociceptiva/metabolismo , Transdução de Sinais/efeitos dos fármacos , Dor Visceral/metabolismo , Animais , Cálcio/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Linhagem Celular , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos Wistar , Canal de Cátion TRPA1/metabolismo
15.
Biochem Biophys Res Commun ; 495(1): 634-638, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29146186

RESUMO

Thrombomodulin (TM), an endothelial protein with anti-coagulant activity, is composed of 5 domains, D1-D5. Recombinant human soluble TM (TMα) consisting of D1-D3, which is generated in CHO cells, suppresses inflammatory and nociceptive signals by inactivating high mobility group box 1 (HMGB1), one of damage-associated molecular patterns. TMα sequesters HMGB1 with the lectin-like D1 and promotes its degradation by thrombin binding to the EGF-like D2. We prepared TM's D123, D1 and D2 by the protein expression system of yeast, and evaluated their effects on HMGB1 degradation in vitro and on the allodynia caused by HMGB1 in distinct redox forms in mice in vivo. TMα and TM's D123, but not D1, promoted the thrombin-dependent degradation of all-thiol (at-HMGB1) and disulfide HMGB1 (ds-HMGB1), an effect mimicked by TM's D2, though to a lesser extent. Intraplantar administration of TMα and TM's D123, but not D1, D2 or D1 plus D2, strongly prevented the mechanical allodynia caused by intraplantar at-HMGB1, ds-HMGB1 or lipopolysaccharide in mice. Our data suggest that, apart from the role of D3, TMα and TM's D123 require both lectin-like D1 capable of sequestering HMGB1 and EGF-like D2 responsible for thrombin-dependent degradation of HMGB1, in abolishing the allodynia caused by exogenous or endogenous HMGB1.


Assuntos
Fator de Crescimento Epidérmico/metabolismo , Proteína HMGB1/antagonistas & inibidores , Proteína HMGB1/metabolismo , Hiperalgesia/tratamento farmacológico , Hiperalgesia/metabolismo , Lectinas/metabolismo , Trombomodulina/administração & dosagem , Animais , Humanos , Masculino , Camundongos , Domínios Proteicos , Solubilidade , Trombomodulina/química , Resultado do Tratamento
16.
Bioorg Med Chem ; 26(15): 4410-4427, 2018 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-30031654

RESUMO

Since 6-prenylnaringenin (6-PNG) was recently identified as a novel T-type calcium channel blocker with the IC50 value around 1 µM, a series of flavanone derivatives were designed, synthesized and subsequently evaluated for T-channel-blocking activity in HEK293 cells transfected with Cav3.2 T-type channels using a patch-clamp technique. As a result, several new flavanones blocked Cav3.2-dependent T-currents more potently than 6-PNG. In the synthesized compounds, 6-(3-ethylpent-2-enyl)-5,7-dihydroxy-2-(2-hydroxyphenyl)chroman-4-one 8j, 6-(3-ethylpent-2-enyl)-5,7-dihydroxy-2-(4-hydroxyphenyl)chroman-4-one 11b, 6-(2-cyclopentylideneethyl)-5,7-dihydroxy-2-(4-hydroxyphenyl)chroman-4-one 11d, and 6-(2-Cyclopentylethyl)-5,7-dihydroxy-2-(4-hydroxyphenyl)chroman-4-one 12c were more potent blocker than 6-PNG with the IC50 value of 0.39, 0.26, 0.46, and 0.50 µM, respectively. Among the above four derivatives, the compound 8j provided the best result in the in vivo experiments; i.e. systemic administration of 8j at the minimum dose completely restored neuropathic pain induced by partial sciatic nerve ligation in mice.


Assuntos
Analgésicos/síntese química , Bloqueadores dos Canais de Cálcio/síntese química , Canais de Cálcio Tipo T/química , Desenho de Fármacos , Flavonoides/química , Potenciais de Ação/efeitos dos fármacos , Analgésicos/farmacologia , Analgésicos/uso terapêutico , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Bloqueadores dos Canais de Cálcio/uso terapêutico , Canais de Cálcio Tipo T/metabolismo , Modelos Animais de Doenças , Flavonoides/farmacologia , Flavonoides/uso terapêutico , Células HEK293 , Humanos , Concentração Inibidora 50 , Masculino , Camundongos , Neuralgia/tratamento farmacológico , Técnicas de Patch-Clamp , Relação Estrutura-Atividade
17.
J Pharmacol Sci ; 136(1): 46-49, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29289470

RESUMO

We studied the pronociceptive role of proteinase-activated receptor-2 (PAR2) in mouse bladder. In female mice, intravesical infusion of the PAR2-activating peptide, SLIGRL-amide (SL), caused delayed mechanical hypersensitivity in the lower abdomen, namely 'referred hyperalgesia', 6-24 h after the administration. The PAR2-triggered referred hyperalgesia was prevented by indomethacin or a selective TRPV1 blocker, and restored by a T-type Ca2+ channel blocker. In human urothelial T24 cells, SL caused delayed prostaglandin E2 production and COX-2 upregulation. Our data suggest that luminal PAR2 stimulation in the bladder causes prostanoid-dependent referred hyperalgesia in mice, which involves the activation of TRPV1 and T-type Ca2+ channels.


Assuntos
Canais de Cálcio Tipo T/fisiologia , Dinoprostona/metabolismo , Hiperalgesia/induzido quimicamente , Hiperalgesia/genética , Dor Nociceptiva/induzido quimicamente , Dor Nociceptiva/genética , Oligopeptídeos/farmacologia , Receptor PAR-2/metabolismo , Receptor PAR-2/fisiologia , Canais de Cátion TRPV/fisiologia , Bexiga Urinária , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo T/metabolismo , Células Cultivadas , Ciclo-Oxigenase 2/metabolismo , Feminino , Humanos , Hiperalgesia/prevenção & controle , Indometacina , Camundongos Endogâmicos , Dor Nociceptiva/prevenção & controle , Canais de Cátion TRPV/antagonistas & inibidores , Canais de Cátion TRPV/metabolismo
18.
Biol Pharm Bull ; 41(8): 1127-1134, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30068860

RESUMO

Voltage-gated calcium channels (VGCCs) are classified into high-voltage-activated (HVA) channels and low-voltage-activated channels consisting of Cav3.1-3.3, known as T ("transient")-type VGCC. There is evidence that certain types of HVA channels are involved in neurogenic inflammation and inflammatory pain, in agreement with reports indicating the therapeutic effectiveness of gabapentinoids, ligands for the α2δ subunit of HVA, in treating not only neuropathic, but also inflammatory, pain. Among the Cav3 family members, Cav3.2 is abundantly expressed in the primary afferents, regulating both neuronal excitability at the peripheral terminals and spontaneous neurotransmitter release at the spinal terminals. The function and expression of Cav3.2 are modulated by a variety of inflammatory mediators including prostanoids and hydrogen sulfide (H2S), a gasotransmitter. The increased activity of Cav3.2 by H2S participates in colonic, bladder and pancreatic pain, and regulates visceral inflammation. Together, VGCCs are involved in inflammation and inflammatory pain, and Cav3.2 T-type VGCC is especially a promising therapeutic target for the treatment of visceral inflammatory pain in patients with irritable bowel syndrome, interstitial cystitis/bladder pain syndrome, pancreatitis, etc., in addition to neuropathic pain.


Assuntos
Canais de Cálcio/fisiologia , Inflamação/fisiopatologia , Dor/fisiopatologia , Animais , Humanos
19.
Clin Exp Pharmacol Physiol ; 45(4): 355-361, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29044685

RESUMO

Hydrogen sulfide (H2 S) is generated from l-cysteine by multiple enzymes including cystathionine-γ-lyase (CSE), and promotes nociception by targeting multiple molecules such as Cav 3.2 T-type Ca2+ channels. Bladder pain accompanying cyclophosphamide (CPA)-induced cystitis in mice has been shown to involve the functional upregulation of the CSE/H2 S/Cav 3.2 pathway. Therefore, we investigated whether NF-κB, as an upstream signal of the CSE/H2 S system, contributes to bladder pain in mice with CPA-induced cystitis. Bladder pain-like nociceptive behaviour was observed in CPA-treated mice, and referred hyperalgesia was evaluated by the von Frey test. Isolated bladder weights were assessed to estimate bladder swelling, and protein levels were measured by Western blotting. CPA, administered intraperitoneally, induced nociceptive behaviour, referred hyperalgesia and increased bladder weights in mice. ß-Cyano-l-alanine, a reversible selective CSE inhibitor, prevented CPA-induced nociceptive behaviour, referred hyperalgesia, and, in part, increases in bladder weight. CPA markedly increased phosphorylated NF-κB p65 levels in the bladder, an effect that was prevented by pyrrolidine dithiocarbamate (PDTC), an NF-κB inhibitor. PDTC and curcumin, which inhibits NF-κB signals, abolished CPA-induced nociceptive behaviour, referred hyperalgesia and, in part, increases in bladder weight. CPA caused the overexpression of CSE in the bladder, and this was prevented by PDTC or curcumin. The CPA-induced activation of NF-κB signals appeared to cause CSE overexpression in the bladder, contributing to bladder pain and in part swelling, possibly through H2 S/Cav 3.2 signaling. Therefore, NF-κB-inhibiting compounds including curcumin may be useful for the treatment of cystitis-related bladder pain.


Assuntos
Cistationina gama-Liase/metabolismo , Cistite/complicações , Sulfeto de Hidrogênio/metabolismo , NF-kappa B/metabolismo , Dor/metabolismo , Regulação para Cima , Bexiga Urinária/metabolismo , Alanina/química , Alanina/farmacologia , Animais , Canais de Cálcio Tipo T/metabolismo , Curcumina/farmacologia , Cistationina gama-Liase/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Feminino , Camundongos , Dor/complicações , Dor/enzimologia , Dor/patologia , Prolina/análogos & derivados , Prolina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Tiocarbamatos/farmacologia , Regulação para Cima/efeitos dos fármacos , Bexiga Urinária/patologia
20.
Biol Pharm Bull ; 40(1): 11-16, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28049943

RESUMO

The rodents exposed to repeated cold stress according to a specific schedule, known as specific alternation of rhythm in temperature (SART), exhibit autonomic imbalance, and is now used as an experimental model of fibromyalgia. To explore the susceptibility of SART-stressed animals to novel acute stress, we tested whether exposure of mice to SART stress for 1 week alters the extent of acute restraint stress-induced hyperthermia. Mice were subjected to 7-d SART stress sessions; i.e., the mice were alternately exposed to 24 and 4°C at 1-h intervals during the daytime (09:00-16:00) and kept at 4°C overnight (16:00-09:00). SART-stressed and unstressed mice were exposed to acute restraint stress for 20-60 min, during which rectal temperature was monitored. Serum corticosterone levels were measured before and after 60-min exposure to restraint stress. SART stress itself did not alter the body temperature or serum corticosterone levels in mice. Acute restraint stress increased the body temperature and serum corticosterone levels, both responses being greater in SART-stressed mice than unstressed mice. The enhanced hyperthermic responses to acute restraint stress in SART-stressed mice were significantly attenuated by SR59230A, a ß3 adrenoceptor antagonist, but unaffected by diazepam, an anxiolytic, mifepristone, a glucocorticoid receptor antagonist, or indomethacin, a cyclooxygenase inhibitor. These results suggest that SART stress enhances the susceptibility of mice to acute restraint stress, characterized by increased hyperthermia and corticosterone secretion, and that the increased hyperthermic responses to acute stress might involve accelerated activation of sympathetic ß3 adrenoceptors, known to regulate non-shivering thermogenesis in the brown adipose tissue.


Assuntos
Temperatura Baixa , Febre , Restrição Física , Estresse Fisiológico , Estresse Psicológico , Tecido Adiposo Marrom , Antagonistas de Receptores Adrenérgicos beta 3 , Animais , Ansiolíticos/farmacologia , Corticosterona/sangue , Diazepam/farmacologia , Febre/sangue , Febre/tratamento farmacológico , Febre/metabolismo , Masculino , Camundongos , Mifepristona/farmacologia , Propanolaminas/farmacologia , Receptores de Glucocorticoides/antagonistas & inibidores , Estresse Psicológico/sangue , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/metabolismo , Proteína Desacopladora 1/metabolismo
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