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1.
Int J Mol Sci ; 22(6)2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33802836

RESUMO

The transient receptor potential ankyrin 1 (TRPA1), a member of the TRP superfamily of channels, acts as 'polymodal cellular sensor' on primary sensory neurons where it mediates the peripheral and central processing of pain, itch, and thermal sensation. However, the TRPA1 expression extends far beyond the sensory nerves. In recent years, much attention has been paid to its expression and function in non-neuronal cell types including skin cells, such as keratinocytes, melanocytes, mast cells, dendritic cells, and endothelial cells. TRPA1 seems critically involved in a series of physiological skin functions, including formation and maintenance of physico-chemical skin barriers, skin cells, and tissue growth and differentiation. TRPA1 appears to be implicated in mechanistic processes in various immunological inflammatory diseases and cancers of the skin, such as atopic and allergic contact dermatitis, psoriasis, bullous pemphigoid, cutaneous T-cell lymphoma, and melanoma. Here, we report recent findings on the implication of TRPA1 in skin physiology and pathophysiology. The potential use of TRPA1 antagonists in the treatment of inflammatory and immunological skin disorders will be also addressed.


Assuntos
Pele/patologia , Pele/fisiopatologia , Canal de Cátion TRPA1/metabolismo , Animais , Humanos , Modelos Biológicos , Pele/metabolismo , Dermatopatias/metabolismo , Dermatopatias/patologia , Dermatopatias/fisiopatologia , Dermatopatias/terapia
2.
Nat Commun ; 12(1): 2074, 2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33824316

RESUMO

Thiazoline-related innate fear-eliciting compounds (tFOs) orchestrate hypothermia, hypometabolism, and anti-hypoxia, which enable survival in lethal hypoxic conditions. Here, we show that most of these effects are severely attenuated in transient receptor potential ankyrin 1 (Trpa1) knockout mice. TFO-induced hypothermia involves the Trpa1-mediated trigeminal/vagal pathways and non-Trpa1 olfactory pathway. TFOs activate Trpa1-positive sensory pathways projecting from trigeminal and vagal ganglia to the spinal trigeminal nucleus (Sp5) and nucleus of the solitary tract (NTS), and their artificial activation induces hypothermia. TFO presentation activates the NTS-Parabrachial nucleus pathway to induce hypothermia and hypometabolism; this activation was suppressed in Trpa1 knockout mice. TRPA1 activation is insufficient to trigger tFO-mediated anti-hypoxic effects; Sp5/NTS activation is also necessary. Accordingly, we find a novel molecule that enables mice to survive in a lethal hypoxic condition ten times longer than known tFOs. Combinations of appropriate tFOs and TRPA1 command intrinsic physiological responses relevant to survival fate.


Assuntos
Medo/fisiologia , Hipotermia/metabolismo , Hipóxia/metabolismo , Canal de Cátion TRPA1/metabolismo , Tiazóis/farmacologia , Animais , Bradicardia/patologia , Medo/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Hipotermia/complicações , Hipóxia/complicações , Masculino , Camundongos Endogâmicos C57BL , Neurônios/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Sensação/efeitos dos fármacos , Tiazóis/química , Fatores de Tempo , Gânglio Trigeminal/efeitos dos fármacos , Gânglio Trigeminal/metabolismo , Nervo Vago/efeitos dos fármacos
3.
Int J Mol Sci ; 22(7)2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33810314

RESUMO

TRPA1, a nonselective cation channel, is expressed in sensory afferent that innervates peripheral targets. Neuronal TRPA1 can promote tissue repair, remove harmful stimuli and induce protective responses via the release of neuropeptides after the activation of the channel by chemical, exogenous, or endogenous irritants in the injured tissue. However, chronic inflammation after repeated noxious stimuli may result in the development of several diseases. In addition to sensory neurons, TRPA1, activated by inflammatory agents from some non-neuronal cells in the injured area or disease, might promote or protect disease progression. Therefore, TRPA1 works as a molecular sentinel of tissue damage or as an inflammation gatekeeper. Most kidney damage cases are associated with inflammation. In this review, we summarised the role of TRPA1 in neurogenic or non-neurogenic inflammation and in kidney disease, especially the non-neuronal TRPA1. In in vivo animal studies, TRPA1 prevented sepsis-induced or Ang-II-induced and ischemia-reperfusion renal injury by maintaining mitochondrial haemostasis or via the downregulation of macrophage-mediated inflammation, respectively. Renal tubular epithelial TRPA1 acts as an oxidative stress sensor to mediate hypoxia-reoxygenation injury in vitro and ischaemia-reperfusion-induced kidney injury in vivo through MAPKs/NF-kB signalling. Acute kidney injury (AKI) patients with high renal tubular TRPA1 expression had low complete renal function recovery. In renal disease, TPRA1 plays different roles in different cell types accordingly. These findings depict the important role of TRPA1 and warrant further investigation.


Assuntos
Nefropatias/metabolismo , Canal de Cátion TRPA1/metabolismo , Animais , Humanos , Inflamação/metabolismo , Nefropatias/patologia , Neurônios/metabolismo , Transdução de Sinais
4.
Int J Mol Sci ; 22(7)2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33807167

RESUMO

Atractylodin (ATR) is a bioactive component found in dried rhizomes of Atractylodes lancea (AL) De Candolle. Although AL has accumulated empirical evidence for the treatment of pain, the molecular mechanism underlying the anti-pain effect of ATR remains unclear. In this study, we found that ATR increases transient receptor potential ankyrin-1 (TRPA1) single-channel activity in hTRPA1 expressing HEK293 cells. A bath application of ATR produced a long-lasting calcium response, and the response was completely diminished in the dorsal root ganglion neurons of TRPA1 knockout mice. Intraplantar injection of ATR evoked moderate and prolonged nociceptive behavior compared to the injection of allyl isothiocyanate (AITC). Systemic application of ATR inhibited AITC-induced nociceptive responses in a dose-dependent manner. Co-application of ATR and QX-314 increased the noxious heat threshold compared with AITC in vivo. Collectively, we concluded that ATR is a unique agonist of TRPA1 channels, which produces long-lasting channel activation. Our results indicated ATR-mediated anti-nociceptive effect through the desensitization of TRPA1-expressing nociceptors.


Assuntos
Furanos/metabolismo , Furanos/farmacologia , Canal de Cátion TRPA1/metabolismo , Analgésicos/metabolismo , Analgésicos/farmacologia , Animais , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Gânglios Espinais/metabolismo , Células HEK293 , Humanos , Isotiocianatos/farmacologia , Lidocaína/análogos & derivados , Lidocaína/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/metabolismo , Nociceptividade/efeitos dos fármacos , Nociceptores/metabolismo , Dor/tratamento farmacológico , Ratos , Ratos Sprague-Dawley , Canal de Cátion TRPA1/agonistas , Canal de Cátion TRPA1/efeitos dos fármacos , Canais de Cátion TRPC/metabolismo , Canais de Receptores Transientes de Potencial/metabolismo
5.
Int J Mol Sci ; 22(5)2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33669091

RESUMO

Oxidative stress and inflammation play important roles in the pathophysiology of acute kidney injury (AKI). Transient receptor potential ankyrin 1 (TRPA1) is a Ca2+-permeable ion channel that is sensitive to reactive oxygen species (ROS). The role of TRPA1 in AKI remains unclear. In this study, we used human and animal studies to assess the role of renal TRPA1 in AKI and to explore the regulatory mechanism of renal TRPA1 in inflammation via in vitro experiments. TRPA1 expression increased in the renal tubular epithelia of patients with AKI. The severity of tubular injury correlated well with tubular TRPA1 or 8-hydroxy-2'-deoxyguanosine expression. In an animal model, renal ischemia-reperfusion injury (IR) increased tubular TRPA1 expression in wild-type (WT) mice. Trpa1-/- mice displayed less IR-induced tubular injury, oxidative stress, inflammation, and dysfunction in kidneys compared with WT mice. In the in vitro model, TRPA1 expression increased in renal tubular cells under hypoxia-reoxygenation injury (H/R) conditions. We demonstrated that H/R evoked a ROS-dependent TRPA1 activation, which elevated intracellular Ca2+ level, increased NADPH oxidase activity, activated MAPK/NF-κB signaling, and increased IL-8. Renal tubular TRPA1 may serve as an oxidative stress sensor and a crucial regulator in the activation of signaling pathways and promote the subsequent transcriptional regulation of IL-8. These actions might be evident in mice with IR or patients with AKI.


Assuntos
Lesão Renal Aguda/metabolismo , Desoxiguanosina/metabolismo , Túbulos Renais/metabolismo , NF-kappa B/metabolismo , Estresse Oxidativo/genética , Traumatismo por Reperfusão/metabolismo , Canal de Cátion TRPA1/metabolismo , Lesão Renal Aguda/enzimologia , Lesão Renal Aguda/genética , Adulto , Animais , Cálcio/metabolismo , Linhagem Celular , Desoxiguanosina/análogos & derivados , Modelos Animais de Doenças , Epitélio/metabolismo , Epitélio/patologia , Humanos , Imuno-Histoquímica , Interleucina-8/metabolismo , Túbulos Renais/citologia , Túbulos Renais/enzimologia , Túbulos Renais/patologia , Sistema de Sinalização das MAP Quinases/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NADP/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Canal de Cátion TRPA1/genética
6.
Int J Mol Sci ; 22(3)2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33540826

RESUMO

Toll-like receptors (TLRs) are key receptors through which infectious and non-infectious challenges act with consequent activation of the inflammatory cascade that plays a critical function in various acute and chronic diseases, behaving as amplification and chronicization factors of the inflammatory response. Previous studies have shown that synthetic analogues of lipid A based on glucosamine with few chains of unsaturated and saturated fatty acids, bind MD-2 and inhibit TLR4 receptors. These synthetic compounds showed antagonistic activity against TLR4 activation in vitro by LPS, but little or no activity in vivo. This study aimed to show the potential use of N-palmitoyl-D-glucosamine (PGA), a bacterial molecule with structural similarity to the lipid A component of LPS, which could be useful for preventing LPS-induced tissue damage or even peripheral neuropathies. Molecular docking and molecular dynamics simulations showed that PGA stably binds MD-2 with a MD-2/(PGA)3 stoichiometry. Treatment with PGA resulted in the following effects: (i) it prevented the NF-kB activation in LPS stimulated RAW264.7 cells; (ii) it decreased LPS-induced keratitis and corneal pro-inflammatory cytokines, whilst increasing anti-inflammatory cytokines; (iii) it normalized LPS-induced miR-20a-5p and miR-106a-5p upregulation and increased miR-27a-3p levels in the inflamed corneas; (iv) it decreased allodynia in peripheral neuropathy induced by oxaliplatin or formalin, but not following spared nerve injury of the sciatic nerve (SNI); (v) it prevented the formalin- or oxaliplatin-induced myelino-axonal degeneration of sciatic nerve. SIGNIFICANCE STATEMENT We report that PGA acts as a TLR4 antagonist and this may be the basis of its potent anti-inflammatory activity. Being unique because of its potency and stability, as compared to other similar congeners, PGA can represent a tool for the optimization of new TLR4 modulating drugs directed against the cytokine storm and the chronization of inflammation.


Assuntos
Analgésicos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Glicolipídeos/uso terapêutico , Hiperalgesia/prevenção & controle , Ceratite/tratamento farmacológico , Neuralgia/tratamento farmacológico , Receptor 4 Toll-Like/antagonistas & inibidores , Analgésicos/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Citocinas/metabolismo , Avaliação Pré-Clínica de Medicamentos , Glicolipídeos/farmacologia , Células HEK293 , Humanos , Hiperalgesia/etiologia , Ceratite/induzido quimicamente , Ceratite/patologia , Lipopolissacarídeos/toxicidade , Antígeno 96 de Linfócito/metabolismo , Masculino , Camundongos , MicroRNAs/genética , Modelos Moleculares , Nociceptores/efeitos dos fármacos , Nociceptores/fisiologia , Conformação Proteica , Células RAW 264.7 , Distribuição Aleatória , Nervo Isquiático/lesões , Canal de Cátion TRPA1/metabolismo
7.
J Ethnopharmacol ; 264: 113342, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32890712

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Cough variant asthma (CVA) is characterized with its long-lasting cough symptom on clinic. The mechanism of CVA is related to chronic persistent airway inflammation, airway hyperresponsiveness, etc. The traditional Chinese prescription has achieved good curative effect on CVA treatment through reducing cough counts, decreasing airway hyperresponsiveness and alleviating airway inflammation. The mechanism is associated with reducing IL4, IL-13, NGF and CGRP levels, as well as down-regulating TRPA1/TRPV1/TRPV5 channels in both lung and brain tissues. AIM OF THE STUDY: The Chinese prescription, San'ao decoction with scorpio and bombyx batryticatus (SSB), is well known in treating cough in asthmatic patients. In this study, the anti-tussive and anti-asthmatic role of SSB, as well as its mechanism on CVA mice model were explored and evaluated via alleviating airway inflammation and regulation of TRP channels. MATERIALS AND METHODS: The major chemical components in SSB were detected and analyzed by UPLC-QTOF-MS under an optimized chromatographic and MS condition. 60 BALB/c mice were randomly divided into six groups: normal group, model group, dexamethasone group (0.1178 mg/kg/d), SSB high dose group (9.74 g/kg/d), SSB middle dose group (4.87 g/kg/d) and SSB low dose group (2.435 g/kg/d). The cough variant asthma mice model was established by ovalbumin sensitization and challenge. The protective role of SSB on CVA mice model was studied through inducing cough counts by capsaicin, assessing inflammatory cells in peripheral blood and bronchoalveolar lavage fluid (BALF), measuring airway responsiveness, detecting histopathological changes in lung tissues, analyzing cytokines and neuropeptides levels in BALF, as well as examining the mRNA and protein expressions of TRPA1, TRPV1 and TRPV5 in both lung and brain tissues. RESULTS: 17 signal peaks of the chemical components in SSB were identified by using UPLC-QTOF-MS. SSB (especially the high dose and middle dose), showed significantly effects on mice model by reducing mice cough counts (P < 0.01), decreasing eosinophil (EOS) counts in blood (P < 0.01) and inflammatory cell numbers in BALF (P < 0.01), decreasing airway hyperresponsiveness (P < 0.05), reducing the levels of IL-4 (P < 0.05), IL-13 (P < 0.01), NGF (P < 0.01) and CGRP (P < 0.01) in BALF, as well as down regulating the mRNA and protein expressions of TRPA1, TRPV1 and TRPV5 in both lung and brain tissues (P < 0.01). CONCLUSIONS: SSB showed anti-tussive and anti-asthmatic effects on cough variant asthma mice model by reducing cough counts, improving lung function, alleviating lung injury and airway inflammation. The mechanism of SSB might be associated with the regulation of cytokines and neuropeptides in BALF, as well as the regulation of TRPA1, TRPV1, TRPV5 channels in both lung and brain tissues.


Assuntos
Antiasmáticos/administração & dosagem , Antitussígenos/administração & dosagem , Bombyx , Medicamentos de Ervas Chinesas/administração & dosagem , Canais de Receptores Transientes de Potencial/antagonistas & inibidores , Animais , Asma/tratamento farmacológico , Asma/metabolismo , Canais de Cálcio/metabolismo , Tosse/tratamento farmacológico , Tosse/metabolismo , Modelos Animais de Doenças , Quimioterapia Combinada , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Canal de Cátion TRPA1/antagonistas & inibidores , Canal de Cátion TRPA1/metabolismo , Canais de Cátion TRPV/antagonistas & inibidores , Canais de Cátion TRPV/metabolismo , Canais de Receptores Transientes de Potencial/metabolismo , Resultado do Tratamento
8.
Int J Mol Sci ; 22(1)2020 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-33374841

RESUMO

Transient receptor potential ankyrin 1 (TRPA1) is a membrane-bound ion channel found in neurons, where it mediates nociception and neurogenic inflammation. Recently, we have discovered that TRPA1 is also expressed in human osteoarthritic (OA) chondrocytes and downregulated by the anti-inflammatory drugs aurothiomalate and dexamethasone. We have also shown TRPA1 to mediate inflammation, pain, and cartilage degeneration in experimental osteoarthritis. In this study, we investigated the role of TRPA1 in joint inflammation, focusing on the pro-inflammatory cytokine interleukin-6 (IL-6). We utilized cartilage/chondrocytes from wild-type (WT) and TRPA1 knockout (KO) mice, along with primary chondrocytes from OA patients. The results show that TRPA1 regulates the synthesis of the OA-driving inflammatory cytokine IL-6 in chondrocytes. IL-6 was highly expressed in WT chondrocytes, and its expression, along with the expression of IL-6 family cytokines leukemia inhibitory factor (LIF) and IL-11, were significantly downregulated by TRPA1 deficiency. Furthermore, treatment with the TRPA1 antagonist significantly downregulated the expression of IL-6 in chondrocytes from WT mice and OA patients. The results suggest that TRPA1 is involved in the upregulation of IL-6 production in chondrocytes. These findings together with previous results on the expression and functions of TRPA1 in cellular and animal models point to the role of TRPA1 as a potential mediator and novel drug target in osteoarthritis.


Assuntos
Condrócitos/metabolismo , Interleucina-6/metabolismo , Osteoartrite/metabolismo , Canal de Cátion TRPA1/metabolismo , Animais , Células Cultivadas , Humanos , Interleucina-11/genética , Interleucina-11/metabolismo , Interleucina-6/genética , Fator Inibidor de Leucemia/genética , Fator Inibidor de Leucemia/metabolismo , Camundongos , Canal de Cátion TRPA1/genética
9.
Toxicon ; 188: 80-88, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33038354

RESUMO

Opioids are the "gold standard" treatment for postoperative pain, but these drugs also have limiting adverse effects. Thus, adjuvant drugs might be useful in opioid therapy for postoperative pain. The aim of the present study was to evaluate the effect of Phα1ß, a dual blocker of Cav2 and TRPA1 channels, on antinociceptive and adverse actions of morphine in a model of postoperative pain. Phα1ß (100-300 pmol/site) or morphine (3-10 mg/kg), alone, largely reduced postoperative nociception. However, Phα1ß (100 pmol/site) or morphine (10 mg/kg) also produced motor impairment. Lower doses of Phα1ß (30 pmol/site) or morphine (1 mg/kg), that did not have an effect alone, showed antinociceptive effect when concomitantly administrated. Moreover, co-administration of Phα1ß (30 pmol/site) with morphine (1 or 10 mg/kg) was unable to cause motor impairment. Preoperative repeated treatment with morphine increased the expression of Cav2 and TRPA1 channels in spinal cord, and caused tolerance and withdrawal syndrome, which were reversed with a single injection of Phα1ß (30 pmol/site). When injected postoperatively, escalating doses of morphine worsened postoperative hyperalgesia, induced tolerance, and withdrawal syndrome. Similarly, Phα1ß (30 pmol/site) reversed these adverse effects. Single or repeated morphine caused constipation, which was not altered by Phα1ß. Thus, a low dose of Phα1ß potentiated the analgesia, and reversed some adverse effects of morphine on operated mice, indicating the potential use of this agent as an adjuvant drug in opioid therapy for postoperative pain.


Assuntos
Analgésicos Opioides/uso terapêutico , Quimioterapia Adjuvante/métodos , Dor Pós-Operatória/tratamento farmacológico , Venenos de Aranha/uso terapêutico , Analgésicos , Animais , Canais de Cálcio Tipo N/metabolismo , Hiperalgesia/induzido quimicamente , Camundongos , Morfina , Venenos de Aranha/farmacologia , Canal de Cátion TRPA1/metabolismo
10.
Mol Pharmacol ; 98(5): 586-597, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32938721

RESUMO

This study investigated the roles of transient receptor potential (TRP) ankyrin-1 (TRPA1) and TRP vanilloid-3 (TRPV3) in regulating endoplasmic reticulum stress (ERS) and cytotoxicity in human bronchial epithelial cells (HBECs) treated with pneumotoxic wood smoke particulate matter (WSPM) and chemical agonists of each channel. Functions of TRPA1 and TRPV3 in pulmonary epithelial cells remain largely undefined. This study shows that TRPA1 activity localizes to the plasma membrane and endoplasmic reticulum (ER) of cells, whereas TRPV3 resides primarily in the ER. Additionally, treatment of cells using moderately cytotoxic concentrations of pine WSPM, carvacrol, and other TRPA1 agonists caused ERS as a function of both TRPA1 and TRPV3 activities. Specifically, ERS and cytotoxicity were attenuated by TRPA1 inhibition, whereas inhibiting TRPV3 exacerbated ERS and cytotoxicity. Interestingly, after treatment with pine WSPM, TRPA1 transcription was suppressed, whereas TRPV3 was increased. TRPV3 overexpression in HBECs conferred resistance to ERS and an attenuation of ERS-associated cell cycle arrest caused by WSPM and multiple prototypical ERS-inducing agents. Alternatively, short hairpin RNA-mediated knockdown of TRPV3, like the TRPV3 antagonist, exacerbated ERS. This study reveals previously undocumented roles for TRPA1 in promoting pathologic ERS and cytotoxicity elicited by pneumotoxic WSPM and TRPA1 agonists, and a unique role for TRPV3 in fettering pathologic facets of the integrated ERS response. SIGNIFICANCE STATEMENT: These findings provide new insights into how wood smoke particulate matter and other transient receptor potential ankyrin-1 (TRPA1) and transient receptor potential vanilloid-3 (TRPV3) agonists can affect human bronchial epithelial cells and highlight novel physiological and pathophysiological roles for TRPA1 and TRPV3 in these cells.


Assuntos
Estresse do Retículo Endoplasmático/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Material Particulado/administração & dosagem , Fumaça/efeitos adversos , Canal de Cátion TRPA1/metabolismo , Canais de Cátion TRPV/metabolismo , Linhagem Celular , Cimenos/efeitos adversos , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Células Epiteliais/metabolismo , Células HEK293 , Humanos , Pulmão/metabolismo , Pinus/efeitos adversos , Canais de Receptores Transientes de Potencial/metabolismo , Madeira/efeitos adversos
11.
Nature ; 585(7823): 141-145, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32641835

RESUMO

The transient receptor potential ion channel TRPA1 is expressed by primary afferent nerve fibres, in which it functions as a low-threshold sensor for structurally diverse electrophilic irritants, including small volatile environmental toxicants and endogenous algogenic lipids1. TRPA1 is also a 'receptor-operated' channel whose activation downstream of metabotropic receptors elicits inflammatory pain or itch, making it an attractive target for novel analgesic therapies2. However, the mechanisms by which TRPA1 recognizes and responds to electrophiles or cytoplasmic second messengers remain unknown. Here we use strutural studies and electrophysiology to show that electrophiles act through a two-step process in which modification of a highly reactive cysteine residue (C621) promotes reorientation of a cytoplasmic loop to enhance nucleophilicity and modification of a nearby cysteine (C665), thereby stabilizing the loop in an activating configuration. These actions modulate two restrictions controlling ion permeation, including widening of the selectivity filter to enhance calcium permeability and opening of a canonical gate at the cytoplasmic end of the pore. We propose a model to explain functional coupling between electrophile action and these control points. We also characterize a calcium-binding pocket that is highly conserved across TRP channel subtypes and accounts for all aspects of calcium-dependent TRPA1 regulation, including potentiation, desensitization and activation by metabotropic receptors. These findings provide a structural framework for understanding how a broad-spectrum irritant receptor is controlled by endogenous and exogenous agents that elicit or exacerbate pain and itch.


Assuntos
Cálcio/metabolismo , Cálcio/farmacologia , Ativação do Canal Iônico/efeitos dos fármacos , Canal de Cátion TRPA1/química , Canal de Cátion TRPA1/metabolismo , Sequência de Aminoácidos , Cisteína/metabolismo , Condutividade Elétrica , Humanos , Iodoacetamida/farmacologia , Modelos Moleculares , Mutação , Oximas/farmacologia , Canal de Cátion TRPA1/genética
12.
Life Sci ; 257: 118112, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32682914

RESUMO

AIMS: STW 5 is an herbal drug combination used for the treatment of functional gastrointestinal disorders (FGIDs) with visceral hypersensitivity as the therapy-resistant hallmark. STW 5 has been clinically proven to alleviate visceral hypersensitivity-related symptoms, including abdominal pain, bloating, nausea, and early satiety. However, the molecular and cellular mechanisms underlying the antinociceptive action of STW 5 remain unknown. Here, we investigate the role of STW 5 in the calcium mobilisation of dorsal root ganglion (DRG) sensory neurons. MAIN METHODS: Calcium imaging experiments were performed with freshly dissociated cultured murine DRG neurons isolated from mice by microfluorometry. TRPA1-deficient DRGs, TRPV1-deficient DRGs, TRPA1/V1 double-deficient DRGs, and wild-type DRGs have been used to investigate the role of TRPs ion channels in mediating STW 5 action. KEY FINDINGS: STW 5 (1.74 and 5.8 mg/ml) induced calcium ion influx into DRG neurons in a concentration-dependent manner. Calcium transients were desensitised during repeated exposure to STW 5, an effect that was facilitated in TRPA1-deficient DRGs and less pronounced in TRPV1-deficient DRGs compared to wild-type (WT) DRGs. SIGNIFICANCE: Repeated exposure to STW 5 induced desensitisation of sensory neurons and may ultimately contribute to its proven clinical efficacy against sensory-related symptoms in patients with FGID, including abdominal pain, bloating, nausea, and early satiety. This effect is modulated by the two prominent irritant sensors in nociceptors, TRPA1 and TRPV1.


Assuntos
Gânglios Espinais/efeitos dos fármacos , Extratos Vegetais/farmacologia , Canais de Receptores Transientes de Potencial/efeitos dos fármacos , Animais , Cálcio/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Canal de Cátion TRPA1/metabolismo , Canais de Cátion TRPV/metabolismo
13.
Mol Pharmacol ; 98(3): 185-191, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32580996

RESUMO

Several general anesthetics (GAs) produce pain or irritation upon administration, and this occurs predominantly through the activation of the nociceptive ion channel, transient receptor potential ankyrin type 1 (TRPA1). However, the effects of GAs on agonist-mediated TRPA1 activity are unclear. Here we show that a diverse range of noxious and non-noxious volatile anesthetics, at clinically relevant concentrations, inhibit ligand-activated TRPA1 currents. These effects are species-specific; GAs blocks rodent TRPA1 without affecting the Drosophila ortholog. Furthermore, propofol inhibits rodent but not human TRPA1. Analysis of chimeric TRPA1 proteins and mutagenesis combined reveals two amino acid residues located in the S5 domain, Ser876 and Thr877, that are critical for the inhibitory effects of isoflurane and propofol. Introduction of these residues into Drosophila TRPA1 confers anesthetic inhibition. Furthermore, several residues lining the presumptive binding pocket for noxious GAs are not required for the inhibitory effects of GAs. We conclude that anesthetics inhibit TRPA1 by interacting at a site distinct from the activation site. The inhibitory effects of GAs at TRPA1 may contribute to the diverse pharmacological action of these drugs. SIGNIFICANCE STATEMENT: We show that both noxious and non-noxious general anesthetics inhibit agonist-evoked transient receptor potential ankyrin type 1 (TRPA1) activity and identify critical amino acid residues located in the pore domain. Inhibition of TRPA1 may affect pain and vascular signaling during anesthesia.


Assuntos
Hipnóticos e Sedativos/farmacologia , Mutação , Canal de Cátion TRPA1/genética , Canal de Cátion TRPA1/metabolismo , Animais , Drosophila melanogaster , Células HEK293 , Humanos , Isoflurano/farmacologia , Camundongos , Propofol/farmacologia , Domínios Proteicos , Ratos , Especificidade da Espécie , Canal de Cátion TRPA1/química
14.
Am J Physiol Gastrointest Liver Physiol ; 319(1): G23-G35, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32421358

RESUMO

Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are released from enteroendocrine cells (EECs) in response to nutrient ingestion and lower blood glucose levels by stimulation of insulin secretion and thus are defined as incretins. GLP-1 receptor (GLP-1R) expression has been identified on enteric neurons that include intrinsic afferent neurons, extrinsic spinal, and vagal sensory afferents but has not been shown to have an incretin effect through these nerves. GLP-1 and GIP enter the mesenteric lymphatic fluid (MLF) after a meal via the interstitial fluid (IF) from local tissue secretion and/or blood capillaries. We tested if MLF could induce diet-dependent intransient increases in intracellular calcium ([Ca2+]i) in cultured sensory neurons. Postprandial rat MLF, collected from the superior mesenteric lymphatic duct, induced a significant twofold higher intransient increase in [Ca2+]i in primary-cultured sensory neurons than MLF from fasted rats. Inhibition of transient receptor potential vanilloid 1 (TRPV1) and TRPV1 and ankyrin 1 cation channels (TRPA1) with ruthenium red eliminated the difference. Substance P (SP) (a peptide that stimulates insulin secretion) sensor cells cocultured with sensory neurons showed both the GLP-1R agonist exendin-4 (Ex-4) and GIP induced transient increases in [Ca2+]i directly coupled to SP secretion in the sensory nerves. Ex-4-induced release of SP required expression of either TRPA1 or TRPV1. These data identify unrecognized actions of GLP-1 and GIP as incretins by acting as neurolymphocrines and suggest a mechanism for sensory nerves to respond to the postprandial state through MLF.NEW & NOTEWORTHY Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are secreted upon eating to lower blood sugar. GLP-1 and GIP were found to induce the secretion of substance P (SP) from cultured sensory nerves. SP enhances insulin secretion. Mesenteric lymphatic fluid (MLF) also stimulates sensory neurons in a diet-dependent manner. These studies identify new actions of GLP-1 and GIP as incretins and suggest a mechanism for sensory nerves to respond to diet through MLF.


Assuntos
Polipeptídeo Inibidor Gástrico/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Glucose/metabolismo , Substância P/metabolismo , Canal de Cátion TRPA1/metabolismo , Animais , Glicemia/metabolismo , Células Enteroendócrinas/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Incretinas/metabolismo , Período Pós-Prandial , Ratos , Receptores dos Hormônios Gastrointestinais
15.
Sci Rep ; 10(1): 8632, 2020 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-32451393

RESUMO

Pain evoked by visceral inflammation is often 'referred' to the somatic level. Transient receptor potential ankyrin 1 (TRPA1) has been reported to contribute to visceral pain-like behavior in dextran sulfate sodium (DSS)-evoked colitis. However, the role of TRPA1 in somatic component of hypersensitivity due to visceral inflammation is unknown. The present study investigated the role of TRPA1 in colitis-evoked mechanical hypersensitivity at the somatic level. Colitis was induced in mice by adding DSS to drinking water for one week. Control and DSS-treated mice were tested for various parameters of colitis as well as mechanical pain sensitivity in abdominal and facial regions. DSS treatment caused mechanical hypersensitivity in the abdominal and facial skin. Pharmacological blockade or genetic deletion of TRPA1 prevented the colitis-associated mechanical hypersensitivity in the abdominal and facial skin areas although the severity of colitis remained unaltered. DSS treatment increased expression of TRPA1 mRNA in cultured dorsal root ganglion (DRG) neurons, but not trigeminal ganglion neurons, and selectively enhanced currents evoked by the TRPA1 agonist, allyl isothiocyanate, in cultured DRG neurons. Our findings indicate that the TRPA1 channel contributes to colitis-associated mechanical hypersensitivity in somatic tissues, an effect associated with upregulation of TRPA1 expression and responsiveness in DRG nociceptors.


Assuntos
Colite/patologia , Dor Nociceptiva/patologia , Canal de Cátion TRPA1/metabolismo , Acetanilidas/farmacologia , Animais , Colite/induzido quimicamente , Sulfato de Dextrana/toxicidade , Potenciais Evocados/efeitos dos fármacos , Gânglios Espinais/citologia , Gânglios Espinais/metabolismo , Isotiocianatos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Purinas/farmacologia , Estresse Mecânico , Canal de Cátion TRPA1/antagonistas & inibidores , Canal de Cátion TRPA1/genética , Gânglio Trigeminal/citologia , Gânglio Trigeminal/metabolismo
16.
Toxicol Appl Pharmacol ; 398: 115012, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32320793

RESUMO

INTRODUCTION: Crotonaldehyde (CR) is an electrophilic α,ß-unsaturated aldehyde present in foods and beverages and is a minor metabolite of 1,3-butadiene. CR is a product of incomplete combustion, and is at high levels in smoke of cigarettes and structural fires. Exposure to CR has been linked to cardiopulmonary toxicity and cardiovascular disease. OBJECTIVE: The purpose of this study was to examine the direct effects of CR in murine blood vessels (aorta and superior mesenteric artery, SMA) using an in vitro system. METHODS AND RESULTS: CR induced concentration-dependent (1-300 µM) relaxations (75-80%) in phenylephrine (PE) precontracted aorta and SMA. Because the SMA was 20× more sensitive to CR than aorta (SMA EC50 3.8 ± 0.5 µM; aorta EC50 76.0 ± 2.0 µM), mechanisms of CR relaxation were studied in SMA. The CR-induced relaxation at low concentrations (1-30 µM) was inhibited by: 1) mechanically-impaired endothelium; 2) Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME); 3) guanylyl cyclase (GC) inhibitor (ODQ); 4) transient receptor potential ankyrin-1 (TRPA1) antagonist (A967079); and, 5) by non-vasoactive level of nicotine (1 µM). Similarly, a TRPA1 agonist, allyl isothiocyanate (AITC; mustard oil), stimulated SMA relaxation dependent on TRPA1, endothelium, NO, and GC. Consistent with these mechanisms, TRPA1 was present in the SMA endothelium. CR, at higher concentrations (100-300 µM), induced tension oscillations (spasms) and irreversibly impaired contractility (a vasotoxic effect enhanced by impaired endothelium). CONCLUSIONS: CR relaxation depends on a functional endothelium and TRPA1, whereas vasotoxicity is enhanced by endothelium dysfunction. Thus, CR is both vasoactive and vasotoxic along a concentration continuum.


Assuntos
Aldeídos/farmacologia , Aorta Torácica/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Canal de Cátion TRPA1/metabolismo , Vasodilatação/efeitos dos fármacos , Animais , Aorta Torácica/metabolismo , Endotélio Vascular/metabolismo , Feminino , Masculino , Camundongos , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/metabolismo , Fenilefrina/metabolismo
17.
Am J Physiol Lung Cell Mol Physiol ; 318(5): L943-L952, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32233794

RESUMO

Transient receptor potential ankyrin-1 (TRPA1) is a ligand-gated cation channel that responds to endogenous and exogenous irritants. TRPA1 is expressed on multiple cell types throughout the lungs, but previous studies have primarily focused on TRPA1 stimulation of airway sensory nerves. We sought to understand the integrated physiological airway response to TRPA1 stimulation. The TRPA1 agonists allyl isothiocyanate (AITC) and cinnamaldehyde (CINN) were tested in sedated, mechanically ventilated guinea pigs in vivo. Reproducible bronchoconstrictions were induced by electrical stimulation of the vagus nerves. Animals were then treated with intravenous AITC or CINN. AITC and CINN were also tested on isolated guinea pig and mouse tracheas and postmortem human trachealis muscle strips in an organ bath. Tissues were contracted with methacholine, histamine, or potassium chloride and then treated with AITC or CINN. Some airways were pretreated with TRPA1 antagonists, the cyclooxygenase inhibitor indomethacin, the EP2 receptor antagonist PF 04418948, or tetrodotoxin. AITC and CINN blocked vagally mediated bronchoconstriction in guinea pigs. Pretreatment with indomethacin completely abolished the airway response to TRPA1 agonists. Similarly, AITC and CINN dose-dependently relaxed precontracted guinea pig, mouse, and human airways in the organ bath. AITC- and CINN-induced airway relaxation required TRPA1, prostaglandins, and PGE2 receptor activation. TRPA1-induced airway relaxation did not require epithelium or tetrodotoxin-sensitive nerves. Finally, AITC blocked airway hyperreactivity in two animal models of allergic asthma. These data demonstrate that stimulation of TRPA1 causes bronchodilation of intact airways and suggest that the TRPA1 pathway is a potential pharmacological target for bronchodilation.


Assuntos
Dinoprostona/metabolismo , Músculo Liso/metabolismo , Canal de Cátion TRPA1/genética , Traqueia/metabolismo , Acroleína/análogos & derivados , Acroleína/farmacologia , Animais , Broncoconstrição/efeitos dos fármacos , Estimulação Elétrica , Regulação da Expressão Gênica , Cobaias , Histamina/farmacologia , Humanos , Indometacina/farmacologia , Isotiocianatos/farmacologia , Masculino , Cloreto de Metacolina/farmacologia , Camundongos , Músculo Liso/efeitos dos fármacos , Técnicas de Cultura de Órgãos , Cloreto de Potássio/farmacologia , Prostaglandina-Endoperóxido Sintases/genética , Prostaglandina-Endoperóxido Sintases/metabolismo , Respiração Artificial , Transdução de Sinais , Canal de Cátion TRPA1/agonistas , Canal de Cátion TRPA1/antagonistas & inibidores , Canal de Cátion TRPA1/metabolismo , Tetrodotoxina/farmacologia , Traqueia/efeitos dos fármacos , Nervo Vago/fisiologia
18.
J Bone Miner Metab ; 38(4): 469-480, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32020290

RESUMO

INTRODUCTION: Cold intolerance is defined as abnormal pain resulting from exposure to cold stimulation after trauma. However, the pathophysiology remains unclear. We recently demonstrated that regional osteoporotic changes accompanied by high bone turnover were involved in causing pain-like behaviors in the unloaded hind limbs of tail-suspended mice. Bisphosphonate prevented pain-like behaviors and high bone turnover conditions in tail-suspended mice. The aims of this study were to examine the relationship between regional osteoporotic changes and the induction of hypersensitivity to cold stimulation. MATERIALS AND METHODS: The hind limbs of tail-suspended mice were unloaded for 2 weeks. The von Frey test and paw-flick test assessed pain-like behaviors and cold plate test evaluated cold escape behaviors. Furthermore, we examined whether cold hypersensitivity associated with regional osteoporotic changes could be improved by bisphosphonate, TRPV1 and TRPA1 antagonists. RESULTS: Hypersensitivity to cold stimulation was induced more noticeably in the tail-suspended mice, and this effect was related to the increased expression of bone metabolism markers. In addition, the cold hypersensitivity was improved by the resumption of weight bearing and prevented by bisphosphonate or a TRPV1 antagonist, and was accompanied with a decrease in the expression of bone metabolism markers. TRPA1 antagonist significantly improved the cold escape behavior, but had no significant effects on the expression of those markers. CONCLUSION: We demonstrated that the regional osteoporotic changes accompanying a high bone turnover state could be involved in the induction of hypersensitivity to cold stimulation in the tail-suspended mice.


Assuntos
Temperatura Baixa , Síndromes Periódicas Associadas à Criopirina/complicações , Elevação dos Membros Posteriores , Osteoporose/complicações , Animais , Comportamento Animal , Diferenciação Celular , Difosfonatos/uso terapêutico , Elevação dos Membros Posteriores/efeitos adversos , Masculino , Camundongos Endogâmicos C57BL , Osteoblastos/patologia , Osteoclastos/patologia , Osteoporose/tratamento farmacológico , Osteoporose/patologia , Dor/patologia , Pele/patologia , Medula Espinal/patologia , Canal de Cátion TRPA1/antagonistas & inibidores , Canal de Cátion TRPA1/metabolismo , Canais de Cátion TRPM/metabolismo , Canais de Cátion TRPV/antagonistas & inibidores , Canais de Cátion TRPV/metabolismo
19.
PLoS Negl Trop Dis ; 14(2): e0008073, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32101555

RESUMO

The Aedes aegypti mosquito serves as a major vector for viral diseases, such as dengue, chikungunya, and Zika, which are spreading across the globe and threatening public health. In addition to increased vector transmission, the prevalence of insecticide-resistant mosquitoes is also on the rise, thus solidifying the need for new, safe and effective insecticides to control mosquito populations. We recently discovered that cinnamodial, a unique drimane sesquiterpene dialdehyde of the Malagasy medicinal plant Cinnamosma fragrans, exhibited significant larval and adult toxicity to Ae. aegypti and was more efficacious than DEET-the gold standard for insect repellents-at repelling adult female Ae. aegypti from blood feeding. In this study several semi-synthetic analogues of cinnamodial were prepared to probe the structure-activity relationship (SAR) for larvicidal, adulticidal and antifeedant activity against Ae. aegypti. Initial efforts were focused on modification of the dialdehyde functionality to produce more stable active analogues and to understand the importance of the 1,4-dialdehyde and the α,ß-unsaturated carbonyl in the observed bioactivity of cinnamodial against mosquitoes. This study represents the first investigation into the SAR of cinnamodial as an insecticide and antifeedant against the medically important Ae. aegypti mosquito.


Assuntos
Aedes/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Inseticidas/farmacologia , Sesquiterpenos Policíclicos/farmacologia , Animais , Feminino , Inseticidas/síntese química , Inseticidas/química , Larva/efeitos dos fármacos , Modelos Moleculares , Estrutura Molecular , Controle de Mosquitos , Sesquiterpenos Policíclicos/síntese química , Sesquiterpenos Policíclicos/química , Conformação Proteica , Canal de Cátion TRPA1/química , Canal de Cátion TRPA1/metabolismo
20.
Yakugaku Zasshi ; 140(1): 1-6, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-31902877

RESUMO

Dysesthesia is an unpleasant abnormal sensation, often accompanied by pain, paresthesia (abnormal sensation), and numbness (decrease or loss of sensation). Dysesthesia has been associated with various conditions, although its underlying mechanisms are largely unknown. This study assessed the roles of transient receptor potential ankyrin 1 (TRPA1) in dysesthesia by utilizing three animal models of dysesthesia characterized by reductions in blood flow to the skin: a transient hindlimb ischemia/reperfusion model, characterized by spontaneous licking and tactile hypoesthesia of the ischemic hindpaw; a streptozotocin-induced diabetic neuropathy model in mice, characterized by cold hypersensitivity, which is likely parallel to the reduced skin blood flow of the hindpaw; and a hindlimb ischemia model. TRPA1 inhibition or deficiency blocked spontaneous licking in the transient hindlimb ischemia/reperfusion model and cold hypersensitivity in the diabetic mouse model mice. Consistent with these results, the nocifensive behaviors induced by intraplantar injection of a TRPA1 agonist were enhanced in the diabetic neuropathy and hindlimb ischemia models. Hypoxia enhanced H2O2-induced TRPA1 responses in human TRPA1-expressing cells and cultured mouse dorsal root ganglion neurons, with this hypoxia-induced TRPA1 sensitization to H2O2 being associated with hypoxia-induced inhibition of the hydroxylation of prolyl hydroxylases. These results suggest that dysesthesia following blood flow reduction is caused by the activation of TRPA1 sensitized by hypoxia and that hypoxia-induced TRPA1 sensitization plays a pivotal role in painful dysesthesia induced by peripheral blood flow reduction.


Assuntos
Parestesia/genética , Canal de Cátion TRPA1/fisiologia , Animais , Neuropatias Diabéticas , Modelos Animais de Doenças , Humanos , Hipóxia , Parestesia/etiologia , Parestesia/fisiopatologia , Fluxo Sanguíneo Regional , Pele/irrigação sanguínea , Canal de Cátion TRPA1/metabolismo
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