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1.
Int J Mol Sci ; 24(14)2023 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-37511555

RESUMO

The transient receptor potential melastatin 4 (TRPM4) channel is a non-selective cation channel that activates in response to increased intracellular Ca2+ levels but does not allow Ca2+ to pass through directly. It plays a crucial role in regulating diverse cellular functions associated with intracellular Ca2+ homeostasis/dynamics. TRPM4 is widely expressed in the heart and is involved in various physiological and pathological processes therein. Specifically, it has a significant impact on the electrical activity of cardiomyocytes by depolarizing the membrane, presumably via Na+ loading. The TRPM4 channel likely contributes to the development of cardiac arrhythmias associated with specific genetic backgrounds and cardiac remodeling. This short review aims to overview what is known so far about the TRPM4 channel in cardiac electrophysiology and arrhythmogenesis, highlighting its potential as a novel therapeutic target to effectively prevent and treat cardiac arrhythmias.


Assuntos
Técnicas Eletrofisiológicas Cardíacas , Canais de Cátion TRPM , Humanos , Canais de Cátion TRPM/genética , Arritmias Cardíacas , Miócitos Cardíacos , Eletrofisiologia Cardíaca
2.
Semin Cell Dev Biol ; 94: 40-49, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30445149

RESUMO

It is now widely accepted that advanced fibrosis underlies many chronic inflammatory disorders and is the main cause of morbidity and mortality of the modern world. The pathogenic mechanism of advanced fibrosis involves diverse and intricate interplays between numerous extracellular and intracellular signaling molecules, among which the non-trivial roles of a stress-responsive Ca2+/Na+-permeable cation channel superfamily, the transient receptor potential (TRP) protein, are receiving growing attention. Available evidence suggests that several TRP channels such as TRPC3, TRPC6, TRPV1, TRPV3, TRPV4, TRPA1, TRPM6 and TRPM7 may play central roles in the progression and/or prevention of fibroproliferative disorders in vital visceral organs such as lung, heart, liver, kidney, and bowel as well as brain, blood vessels and skin, and may contribute to both acute and chronic inflammatory processes involved therein. This short paper overviews the current knowledge accumulated in this rapidly growing field, with particular focus on cardiac and intestinal fibrosis, which are tightly associated with the pathogenesis of atrial fibrillation and inflammatory bowel diseases such as Crohn's disease.


Assuntos
Fibrose/metabolismo , Enteropatias/metabolismo , Miocárdio/metabolismo , Canais de Potencial de Receptor Transitório/metabolismo , Animais , Fibrose/patologia , Humanos , Enteropatias/patologia , Miocárdio/patologia
3.
J Mol Cell Cardiol ; 148: 50-62, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32889002

RESUMO

Pulmonary arterial hypertension (PAH) is a multifactorial disease characterized by pulmonary arterial vasoconstriction and remodeling. Src family tyrosine kinases, including Fyn, play critical roles in vascular remodeling via the inhibition of STAT3 signaling. EPA is known to inhibit Fyn kinase activity. This study investigated the therapeutic potential and underlying mechanisms of EPA and its metabolite, resolvin E1 (RvE1), to treat PAH using monocrotaline-induced PAH model rats (MCT-PAH), human pulmonary artery endothelial cells (HPAECs), and human pulmonary artery smooth muscle cells (HPASMCs). Administration of EPA 1 and 2 weeks after MCT injection both ameliorated right ventricular hypertrophy, remodeling and dysfunction, and medial wall thickening of the pulmonary arteries and prolonged survival in MCT-PAH rats. EPA attenuated the enhanced contractile response to 5-hydroxytryptamine in isolated pulmonary arteries of MCT-PAH rats. Mechanistically, the treatment with EPA and RvE1 or the introduction of dominant-negative Fyn prevented TGF-ß2-induced endothelial-to-mesenchymal transition and IL-6-induced phosphorylation of STAT3 in cultured HPAECs. EPA and RvE1 suppressed Src family kinases' activity as evaluated by their phosphorylation status in cultured HPAECs and HPASMCs. EPA and RvE1 suppressed vasocontraction of rat and human PA. Furthermore, EPA and RvE1 inhibited the enhanced proliferation and activity of Src family kinases in HPASMCs derived from patients with idiopathic PAH. EPA ameliorated PAH's pathophysiology by mitigating vascular remodeling and vasoconstriction, probably inhibiting Src family kinases, especially Fyn. Thus, EPA is considered a potent therapeutic agent for the treatment of PAH.


Assuntos
Ácido Eicosapentaenoico/uso terapêutico , Hipertensão Pulmonar/tratamento farmacológico , Hipertensão Pulmonar/enzimologia , Proteínas Proto-Oncogênicas c-fyn/antagonistas & inibidores , Animais , Proliferação de Células/efeitos dos fármacos , Ácido Eicosapentaenoico/análogos & derivados , Ácido Eicosapentaenoico/farmacologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/patologia , Endotélio Vascular/fisiopatologia , Humanos , Hipertensão Pulmonar/fisiopatologia , Hipertrofia Ventricular Direita/complicações , Hipertrofia Ventricular Direita/fisiopatologia , Interleucina-6/farmacologia , Masculino , Mesoderma/efeitos dos fármacos , Mesoderma/patologia , Mesoderma/fisiopatologia , Monocrotalina , Contração Miocárdica/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/fisiopatologia , Ratos Sprague-Dawley , Fator de Transcrição STAT3/metabolismo , Análise de Sobrevida , Fator de Crescimento Transformador beta2/farmacologia , Vasodilatação/efeitos dos fármacos , Remodelação Ventricular/efeitos dos fármacos , Quinases da Família src/metabolismo
4.
Biomedicines ; 12(3)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38540144

RESUMO

Intestinal bacteria play important roles in the progression of colitis-associated carcinogenesis. Colostrum-derived Lacticaseibacillus rhamnosus Probio-M9 (Probio-M9) has shown a protective effect in a colitis-associated cancer (CAC) model, but detailed metagenomic analysis had not been performed. Here, we investigated the preventive effects of the probiotic Probio-M9 on CAC-model mice, tracking the microbiota. Feces were obtained at four time points for evaluation of gut microbiota. The effect of Probio-M9 on tight junction protein expression was evaluated in co-cultured Caco-2 cells. Probio-M9 treatment decreased the number of tumors as well as stool consistency score, spleen weight, inflammatory score, and macrophage expression in the CAC model. Probio-M9 accelerated the recovery of the structure, composition, and function of the intestinal microbiota destroyed by azoxymethane (AOM)/dextran sulfate sodium (DSS) by regulating key bacteria (including Lactobacillus murinus, Muribaculaceae bacterium DSM 103720, Muribaculum intestinale, and Lachnospiraceae bacterium A4) and pathways from immediately after administration until the end of the experiment. Probio-M9 co-culture protected against lipopolysaccharide-induced impairment of tight junctions in Caco-2 cells. This study provides valuable insight into the role of Probio-M9 in correcting gut microbiota defects associated with inflammatory bowel disease carcinogenesis and may have clinical application in the treatment of inflammatory carcinogenesis.

5.
Nutrients ; 14(3)2022 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-35277009

RESUMO

Lactulose, a galactose-fructose disaccharide, is made from the milk sugar lactose by heating or isomerization processes. Lactulose is proposed to modulate gut microbiota and thus expected to be beneficial in treating inflammatory bowel disease. In the present study, we investigated the therapeutic effect of lactulose on gastrointestinal inflammation and inflammation-related tumorigenesis in a mouse model of colorectal cancer as well as its effect on gut microbiota composition. Azoxymethane (AOM)/dextran sulfate sodium (DSS) model was used in this study. Lactulose treatment was performed by feeding 2% lactulose for 14 weeks. Stool samples collected at 4 time points were used for metagenomic analysis of the microbiota. Pathological analysis was performed 21 weeks after AOM injection. AOM/DSS increased the macrophage counts, inflammatory cytokine expression, colorectal tumorigenesis, and imbalance in gut microbiota composition, as evidenced by increased pathogen abundance (e.g., Escherichia and Clostridium). Lactulose significantly inhibited the inflammatory events, and ameliorated inflammation and tumorigenesis. The composition of the intestinal microbiota was also restored upon lactulose treatment, and lactulose reduced pathogen abundance and increased the abundance of Muribaculum and Lachnospiraceae. Meanwhile, the pathways related to Crohn's disease were downregulated after lactulose treatment. Our findings suggest that lactulose restores the structure and composition of the intestinal microbiota, mitigates inflammation, and suppresses inflammatory tumorigenesis.


Assuntos
Colite , Microbioma Gastrointestinal , Animais , Carcinogênese , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/patologia , Sulfato de Dextrana/farmacologia , Lactulose/farmacologia , Camundongos
6.
J Smooth Muscle Res ; 58(0): 50-62, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35944979

RESUMO

Pulmonary arterial hypertension (PAH) is an intractable vascular disease characterized by a progressive increase in pulmonary vascular resistance caused by pulmonary vascular remodeling, which ultimately leads to right-sided heart failure. PAH remains incurable, despite the development of PAH-targeted therapeutics centered on pulmonary artery relaxants. It is necessary to identify the target molecules that contribute to pulmonary artery remodeling. Transient receptor potential (TRP) channels have been suggested to modulate pulmonary artery remodeling. Our study focused on the transient receptor potential ion channel subfamily M, member 7, or the TRPM7 channel, which modulates endothelial-to-mesenchymal transition and smooth muscle proliferation in the pulmonary artery. In this review, we summarize the role and expression profile of TRPM7 channels in PAH progression and discuss TRPM7 channels as possible therapeutic targets. In addition, we discuss the therapeutic effect of a Chinese herbal medicine, Ophiocordyceps sinensis (OCS), on PAH progression, which partly involves TRPM7 inhibition.


Assuntos
Hipertensão Pulmonar , Hipertensão Arterial Pulmonar , Canais de Cátion TRPM , Canais de Potencial de Receptor Transitório , Proliferação de Células , Hipertensão Pulmonar Primária Familiar/metabolismo , Humanos , Hipertensão Pulmonar/tratamento farmacológico , Hipertensão Pulmonar/metabolismo , Miócitos de Músculo Liso/metabolismo , Proteínas Serina-Treonina Quinases , Hipertensão Arterial Pulmonar/tratamento farmacológico , Artéria Pulmonar/metabolismo , Canais de Cátion TRPM/metabolismo , Canais de Potencial de Receptor Transitório/metabolismo , Canais de Potencial de Receptor Transitório/uso terapêutico , Remodelação Vascular
7.
Nutrients ; 13(4)2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33808480

RESUMO

Chronic inflammation is a risk factor for colorectal cancer, and inflammatory cytokines secreted from inflammatory cells and active oxygen facilitate tumorigenesis. Intestinal bacteria are thought to regulate tumorigenesis. The longer the breastfeeding period, the lower is the risk of inflammatory bowel disease. Here, we investigated preventive effects of the probiotic Lactobacillus rhamnosus M9 (Probio-M9) on colitis-associated tumorigenesis. An inflammatory colorectal tumor model was established using a 6-week-old male C57BL/6NCrSlc mouse, which was intraperitoneally administered with azoxymethane (AOM: 12 mg/kg body weight). On weeks 2 and 4, 2% dextran sulfate sodium (DSS) was administered to mice for 7 days through drinking water. On weeks 8 and 10, Probio-M9 (2 × 109/day) was orally administered for 7 days. Animals were sacrificed at 20 weeks after AOM administration and immunohistochemical staining and Western blotting was performed. The α-diversity of microflora (Shannon index), principal coordinate analysis, and distribution of intestinal bacterium genera and metabolic pathways were compared. The AOM/DSS group showed weight loss, diarrhea, intestinal shortening, increased number of colon tumors, proliferating tumorigenesis, increased inflammation score, fibrosis, increased CD68+, or CD163+ macrophage cells in the subserosal layer of non-tumor areas. Inflammation and tumorigenesis ameliorated after Probio-M9 treatment. Fecal microbial functions were altered by AOM/DSS treatment. Probio-M9 significantly upregulated the fecal microbial diversity and reversed fecal microbial functions. Thus, Probio-M9 could suppress tumor formation in the large intestine by regulating the intestinal environment and ameliorating inflammation, suggesting its therapeutic potential for treatment of inflammation and colitis-associated tumorigenesis.


Assuntos
Colite/induzido quimicamente , Neoplasias do Colo/etiologia , Microbioma Gastrointestinal , Lacticaseibacillus rhamnosus/fisiologia , Leite Humano/microbiologia , Carcinogênese , Colite/complicações , Neoplasias do Colo/prevenção & controle , Sulfato de Dextrana/toxicidade , Humanos , Inflamação/prevenção & controle , Lacticaseibacillus rhamnosus/classificação , Masculino , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia
8.
Cells ; 10(5)2021 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-33922380

RESUMO

A Ca2+-activated monovalent cation-selective TRPM4 channel is abundantly expressed in the heart. Recently, a single gain-of-function mutation identified in the distal N-terminus of the human TRPM4 channel (Glu5 to Lys5; E7K) was found to be arrhythmogenic because of enhanced cell membrane expression. In this study, we conducted detailed analyses of this mutant channel from more functional aspects, in comparison with its wild type (WT). In an expression system, intracellular application of a short soluble PIP2 (diC8PIP2) restored the single-channel activities of both WT and E7K, which had quickly faded after membrane excision. The potency (Kd) of diC8PIP2 for this recovery was stronger in E7K than its WT (1.44 vs. 2.40 µM). FRET-based PIP2 measurements combined with the Danio rerio voltage-sensing phosphatase (DrVSP) and patch clamping revealed that lowering the endogenous PIP2 level by DrVSP activation reduced the TRPM4 channel activity. This effect was less prominent in E7K than its WT (apparent Kd values estimated from DrVSP-mediated PIP2 depletion: 0.97 and 1.06 µM, respectively), being associated with the differential PIP2-mediated modulation of voltage dependence. Moreover, intracellular perfusion of short N-terminal polypeptides containing either the 'WT' or 'E7K' sequences respectively attenuated the TRPM4 channel activation at whole-cell and single-channel levels, but in both configurations, the E7K polypeptide exerted greater inhibitory effects. These results collectively suggest that N-terminal interaction with endogenous PIP2 is essential for the TRPM4 channel to function, the extent of which may be abnormally strengthened by the E7K mutation through modulating voltage-dependent activation. The altered PIP2 interaction may account for the arrhythmogenic potential of this mutation.


Assuntos
Potenciais de Ação , Arritmias Cardíacas/patologia , Mutação com Ganho de Função , Fosfatidilinositol 4,5-Difosfato/metabolismo , Canais de Cátion TRPM/genética , Canais de Cátion TRPM/metabolismo , Arritmias Cardíacas/genética , Células HEK293 , Humanos
9.
Transl Res ; 233: 127-143, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33691194

RESUMO

Ophiocordyceps sinensis (OCS), an entomopathogenic fungus, is known to exert antiproliferative and antitissue remodeling effects. Vascular remodeling and vasoconstriction play critical roles in the development of pulmonary hypertension (PH). The therapeutic potential of OCS for PH was investigated using rodent PH models, and cultured pulmonary artery endothelial and smooth muscle cells (PAECs and PASMCs), with a focus on the involvement of TRPM7. OCS ameliorated the development of PH, right ventricular hypertrophy and dysfunction in the monocrotaline-induced PH rats. The genetic knockout of TRPM7 attenuated the development of PH in mice with monocrotaline pyrrole-induced PH. TRPM7 was associated with medial hypertrophy and the plexiform lesions in rats and humans with PH. OCS suppressed proliferation of PASMCs derived from the PH patients. Ethanol extracts of OCS inhibited TRPM7-like current, TGF-ß2-induced endothelial-mesenchymal transition, IL-6-induced STAT3 phosphorylation, and PDGF-induced Akt phosphorylation in PAECs or PASMCs. These inhibitory effects were recapitulated by either siRNA-mediated TRPM7 knockdown or treatment with TRPM7 antagonist FTY-720. OCS and FTY-720 induced vasorelaxation in the isolated normal human pulmonary artery. As a result, the present study proposes the therapeutic potential of OCS for the treatment of PH. The inhibition of TRPM7 is suggested to underlie the therapeutic effect of OCS.


Assuntos
Cordyceps/fisiologia , Hipertensão Pulmonar/fisiopatologia , Hipertensão Pulmonar/terapia , Canais de Cátion TRPM/antagonistas & inibidores , Animais , Proliferação de Células , Células Cultivadas , Modelos Animais de Doenças , Cloridrato de Fingolimode/farmacologia , Técnicas de Silenciamento de Genes , Humanos , Hipertensão Pulmonar/patologia , Masculino , Medicina Tradicional Chinesa , Camundongos , Camundongos Knockout , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/fisiologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Artéria Pulmonar/patologia , Artéria Pulmonar/fisiopatologia , Ratos , Ratos Sprague-Dawley , Fator de Transcrição STAT3/metabolismo , Canais de Cátion TRPM/deficiência , Canais de Cátion TRPM/genética , Canais de Cátion TRPM/fisiologia , Pesquisa Translacional Biomédica , Vasodilatação
10.
J Smooth Muscle Res ; 55(0): 81-107, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32023567

RESUMO

In the past few decades, solid evidence has been accumulated for the pivotal significance of immunoinflammatory processes in the initiation, progression, and exacerbation of many diseases and disorders. This groundbreaking view came from original works by Ross who first described that excessive inflammatory-fibroproliferative response to various forms of insult to the endothelium and smooth muscle of the artery wall is essential for the pathogenesis of atherosclerosis (Ross, Nature 1993; 362(6423): 801-9). It is now widely recognized that both innate and adaptive immune reactions are avidly involved in the inflammation-related remodeling of many tissues and organs. When this state persists, irreversible fibrogenic changes would occur often culminating in fatal insufficiencies of many vital parenchymal organs such as liver, lung, heart, kidney and intestines. Thus, inflammatory diseases are becoming the common life-threatening risk for and urgent concern about the public health in developed countries (Wynn et al., Nature Medicine 2012; 18(7): 1028-40). Considering this timeliness, we organized a special symposium entitled "Implications of immune/inflammatory responses in smooth muscle dysfunction and disease" in the 58th annual meeting of the Japan Society of Smooth Muscle Research. This symposium report will provide detailed synopses of topics presented in this symposium; (1) the role of inflammasome in atherosclerosis and abdominal aortic aneurysms by Fumitake Usui-Kawanishi and Masafumi Takahashi; (2) Mechanisms underlying the pathogenesis of hyper-contractility of bronchial smooth muscle in allergic asthma by Hiroyasu Sakai, Wataru Suto, Yuki Kai and Yoshihiko Chiba; (3) Vascular remodeling in pulmonary arterial hypertension by Keizo Hiraishi, Lin Hai Kurahara and Ryuji Inoue.


Assuntos
Imunidade Adaptativa , Aterosclerose , Músculo Liso Vascular , Animais , Aterosclerose/imunologia , Aterosclerose/patologia , Congressos como Assunto , Humanos , Inflamação/imunologia , Inflamação/patologia , Japão , Músculo Liso Vascular/imunologia , Músculo Liso Vascular/patologia
11.
World J Gastroenterol ; 24(35): 4036-4053, 2018 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-30254408

RESUMO

AIM: To investigate the anti-fibrotic effects of the traditional oriental herbal medicine Daikenchuto (DKT) associated with transient receptor potential ankyrin 1 (TRPA1) channels in intestinal myofibroblasts. METHODS: Inflammatory and fibrotic changes were detected in a 2,4,6-trinitrobenzenesulfonic acid (TNBS) chronic colitis model of wild-type and TRPA1-knockout (TRPA1-KO) mice via pathological staining and immunoblotting analysis. Ca2+ imaging experiments examined the effects of DKT and its components/ingredients on intestinal myofibroblast (InMyoFib) cell TRPA1 channel function. Pro-fibrotic factors and transforming growth factor (TGF)-ß1-associated signaling were tested in an InMyoFib cell line by qPCR and immunoblotting experiments. Samples from non-stenotic and stenotic regions of the intestines of patients with Crohn's disease (CD) were used for pathological analysis. RESULTS: Chronic treatment with TNBS caused more severe inflammation and fibrotic changes in TRPA1-KO than in wild-type mice. A one-week enema administration of DKT reduced fibrotic lesions in wild-type but not in TRPA1-KO mice. The active ingredients of DKT, i.e., hydroxy α-sanshool and 6-shogaol, induced Ca2+ influxes in InMyoFib, and this was antagonized by co-treatment with a selective TRPA1 channel blocker, HC-030031. DKT counteracted TGF-ß1-induced expression of Type I collagen and α-smooth muscle actin (α-SMA), which were accompanied by a reduction in the phosphorylation of Smad-2 and p38-mitogen-activated protein kinase (p38-MAPK) and the expression of myocardin. Importantly, 24-h incubation with a DKT active component Japanese Pepper increased the mRNA and protein expression levels of TRPA1 in InMyoFibs, which in turn negatively regulated collagen synthesis. In the stenotic regions of the intestines of CD patients, TRPA1 expression was significantly enhanced. CONCLUSION: The effects of DKT on the expression and activation of the TRPA1 channel could be advantageous for suppressing intestinal fibrosis, and benefit inflammatory bowel disease treatment.


Assuntos
Colite/tratamento farmacológico , Colo/patologia , Extratos Vegetais/farmacologia , Canal de Cátion TRPA1/metabolismo , Adulto , Animais , Linhagem Celular , Doença Crônica/tratamento farmacológico , Colite/induzido quimicamente , Colite/patologia , Colo/citologia , Colo/efeitos dos fármacos , Colo/cirurgia , Doença de Crohn/patologia , Doença de Crohn/cirurgia , Modelos Animais de Doenças , Fibrose , Humanos , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Miofibroblastos/metabolismo , Panax , Extratos Vegetais/uso terapêutico , Canal de Cátion TRPA1/genética , Ácido Trinitrobenzenossulfônico/toxicidade , Zanthoxylum , Zingiberaceae
12.
Cell Mol Gastroenterol Hepatol ; 5(3): 299-318, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29552620

RESUMO

BACKGROUND & AIMS: The transient receptor potential ankyrin 1 (TRPA1) channel is highly expressed in the intestinal lamina propria, but its contribution to gut physiology/pathophysiology is unclear. Here, we evaluated the function of myofibroblast TRPA1 channels in intestinal remodeling. METHODS: An intestinal myofibroblast cell line (InMyoFibs) was stimulated by transforming growth factor-ß1 to induce in vitro fibrosis. Trpa1 knockout mice were generated using the Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) system. A murine chronic colitis model was established by weekly intrarectal trinitrobenzene sulfonic acid (TNBS) administration. Samples from the intestines of Crohn's disease (CD) patients were used for pathologic staining and quantitative analyses. RESULTS: In InMyoFibs, TRPA1 showed the highest expression among TRP family members. In TNBS chronic colitis model mice, the extents of inflammation and fibrotic changes were more prominent in TRPA1-/- knockout than in wild-type mice. One-week enema administration of prednisolone suppressed fibrotic lesions in wild-type mice, but not in TRPA1 knockout mice. Steroids and pirfenidone induced Ca2+ influx in InMyoFibs, which was antagonized by the selective TRPA1 channel blocker HC-030031. Steroids and pirfenidone counteracted transforming growth factor-ß1-induced expression of heat shock protein 47, type 1 collagen, and α-smooth muscle actin, and reduced Smad-2 phosphorylation and myocardin expression in InMyoFibs. In stenotic intestinal regions of CD patients, TRPA1 expression was increased significantly. TRPA1/heat shock protein 47 double-positive cells accumulated in the stenotic intestinal regions of both CD patients and TNBS-treated mice. CONCLUSIONS: TRPA1, in addition to its anti-inflammatory actions, may protect against intestinal fibrosis, thus being a novel therapeutic target for highly incurable inflammatory/fibrotic disorders.

13.
Cardiovasc Res ; 113(10): 1243-1255, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28898995

RESUMO

AIMS: Transient receptor potential cation channel subfamily melastatin member 4 (TRPM4), a Ca2+-activated nonselective cation channel abundantly expressed in the heart, has been implicated in conduction block and other arrhythmic propensities associated with cardiac remodelling and injury. The present study aimed to quantitatively evaluate the arrhythmogenic potential of TRPM4. METHODS AND RESULTS: Patch clamp and biochemical analyses were performed using expression system and an immortalized atrial cardiomyocyte cell line (HL-1), and numerical model simulation was employed. After rapid desensitization, robust reactivation of TRPM4 channels required high micromolar concentrations of Ca2+. However, upon evaluation with a newly devised, ionomycin-permeabilized cell-attached (Iono-C/A) recording technique, submicromolar concentrations of Ca2+ (apparent Kd = ∼500 nM) were enough to activate this channel. Similar submicromolar Ca2+ dependency was also observed with sharp electrode whole-cell recording and in experiments coexpressing TRPM4 and L-type voltage-dependent Ca2+ channels. Numerical simulations using a number of action potential (AP) models (HL-1, Nygren, Luo-Rudy) incorporating the Ca2+- and voltage-dependent gating parameters of TRPM4, as assessed by Iono-C/A recording, indicated that a few-fold increase in TRPM4 activity is sufficient to delay late AP repolarization and further increases (≥ six-fold) evoke early afterdepolarization. These model predictions are consistent with electrophysiological data from angiotensin II-treated HL-1 cells in which TRPM4 expression and activity were enhanced. CONCLUSIONS: These results collectively indicate that the TRPM4 channel is activated by a physiological range of Ca2+ concentrations and its excessive activity can cause arrhythmic changes. Moreover, these results demonstrate potential utility of the first AP models incorporating TRPM4 gating for in silico assessment of arrhythmogenicity in remodelling cardiac tissue.


Assuntos
Potenciais de Ação , Arritmias Cardíacas/metabolismo , Simulação por Computador , Átrios do Coração/metabolismo , Frequência Cardíaca , Modelos Cardiovasculares , Miócitos Cardíacos/metabolismo , Análise Numérica Assistida por Computador , Canais de Cátion TRPM/metabolismo , Potenciais de Ação/efeitos dos fármacos , Angiotensina II/farmacologia , Animais , Arritmias Cardíacas/genética , Arritmias Cardíacas/fisiopatologia , Sinalização do Cálcio , Células HEK293 , Átrios do Coração/efeitos dos fármacos , Átrios do Coração/fisiopatologia , Frequência Cardíaca/efeitos dos fármacos , Humanos , Cinética , Camundongos , Miócitos Cardíacos/efeitos dos fármacos , Técnicas de Patch-Clamp , Período Refratário Eletrofisiológico , Canais de Cátion TRPM/genética
14.
J Phys Chem B ; 110(33): 16550-8, 2006 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-16913789

RESUMO

Electroreflectance (ER) spectroscopy was used for the estimation of the orientation of heme in a horse heart cytochrome c molecule immobilized on a self-assembled monolayer of 11-mercaptoundecanoic acid on both polycrystalline gold (Au) and single crystalline Au(111) electrodes. The intensity ratio of the ER signal of p-polarized incident light against s-polarized incident light as a function of the incident angle of the light was analyzed in two ways: a doubly degenerate transition for the Soret absorption band of the heme was assumed in one, and the anisotropy of the two orthogonal transitions was taken into account in the other. The doubly degenerate model failed in the expression of the experimental data, pointing to the existence of the anisotropy. Two orthogonal in-plane linear electric dipoles with different magnitudes were assumed to be responsible for the Soret band absorption in a new analysis procedure. This enabled us to fit the experimental data closely to the simulated data. The result revealed that the heme plane is near-vertical to the electrode surface. The need of clarification of the anisotropic heme transition was invoked.


Assuntos
Citocromos c/química , Enzimas Imobilizadas , Ouro/química , Heme/química , Modelos Biológicos , Alcanos/química , Animais , Anisotropia , Ácidos Carboxílicos/química , Eletroquímica , Eletrodos , Cavalos , Luz , Miocárdio/enzimologia , Rotação Ocular , Análise Espectral/métodos , Compostos de Sulfidrila/química , Propriedades de Superfície
15.
J Smooth Muscle Res ; 52(0): 78-92, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27818466

RESUMO

Intestinal fibrosis is an intractable complication of Crohn's disease (CD), and, when occurring excessively, causes severe intestinal obstruction that often necessitates surgical resection. The fibrosis is characterized by an imbalance in the turnover of extracellular matrix (ECM) components, where intestinal fibroblasts/myofibroblasts play active roles in ECM production, fibrogenesis and tissue remodeling, which eventually leads to the formation of stenotic lesions. There is however a great paucity of knowledge about how intestinal fibrosis initiates and progresses, which hampers the development of effective pharmacotherapies against CD. Recently, we explored the potential implications of transient receptor potential (TRP) channels in the pathogenesis of intestinal fibrosis, since they are known to act as cellular stress sensors/transducers affecting intracellular Ca2+ homeostasis/dynamics, and are involved in a broad spectrum of cell pathophysiology including inflammation and tissue remodeling. In this review, we will place a particular emphasis on the intestinal fibroblast/myofibroblast TRPC6 channel to discuss its modulatory effects on fibrotic responses and therapeutic potential for anti-fibrotic treatment against CD-related stenosis.


Assuntos
Cálcio/metabolismo , Doença de Crohn/etiologia , Obstrução Intestinal/etiologia , Intestinos/patologia , Canais de Cátion TRPC/fisiologia , Doença de Crohn/tratamento farmacológico , Doença de Crohn/patologia , Matriz Extracelular/metabolismo , Fibroblastos/fisiologia , Fibrose , Humanos , Intestinos/citologia , Terapia de Alvo Molecular , Miofibroblastos/fisiologia , Transdução de Sinais/fisiologia , Canal de Cátion TRPC6 , Fator de Crescimento Transformador beta1/fisiologia
16.
Inflamm Bowel Dis ; 21(3): 496-506, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25647156

RESUMO

BACKGROUND: Intestinal fibrosis is a frequent complication of Crohn's disease (CD) and often leads to detrimental stricture formation. Myofibroblasts play active roles in mediating fibrotic changes in various tissues. We investigated whether transient receptor potential channels in intestinal myofibroblasts are involved in CD-associated intestinal fibrosis. METHODS: An intestinal myofibroblast cell line (InMyoFibs) was stimulated with transforming growth factor-ß1 (TGF-ß1) to model excessive fibrosis. Biopsy samples from nonstenotic or stenotic intestinal regions from patients with CD were used for quantitative comparisons of transient receptor potential channel and fibrosis-associated factor expression levels. RESULTS: TGF-ß1 treatment transformed spindle-shaped InMyoFibs into filament-shaped cells with enhanced α-actin stress fiber formation, transient receptor potential canonical (TRPC) 4 and TRPC6 messenger RNA and protein expression, and basal- and agonist-induced Ca influxes. TGF-ß1 also enhanced the formation of TRPC6/smooth muscle α-actin, TRPC6/N-cadherin, and TRPC4/N-cadherin coimmunoprecipitates. Inhibition of TRPC6 in InMyoFibs by RNA interference or dominant-negative mutations suppressed TGF-ß1-induced Ca influxes, stress fiber formation, and smooth muscle α-actin expression, but increased COL1A1, interleukin (IL)-10, and IL-11 expression, as well as Smad-2, ERK, and p38-MAPK phosphorylation. Similar increases in phosphorylation levels were observed with TRPC and calcineurin inhibitors. In stenotic areas in patients with CD, TRPC6, ACTA2 (smooth muscle α-actin), CDH2 (N-cadherin), COL1A1, IL-10, and IL-11 were significantly increased. CONCLUSIONS: These results suggest that augmented Ca influxes due to TRPC6 upregulation facilitate stress fiber formation and strengthen cell-cell interactions by negatively regulating the synthesis of antifibrotic factors in TGF-ß1-treated myofibroblasts. Similar changes observed in stenotic areas of patients with CD suggest the therapeutic significance of targeting TRPC6.


Assuntos
Doenças do Colo/etiologia , Doença de Crohn/complicações , Fibrose/etiologia , Mucosa Intestinal/metabolismo , Miofibroblastos/metabolismo , Canais de Cátion TRPC/metabolismo , Adulto , Western Blotting , Células Cultivadas , Doenças do Colo/metabolismo , Doenças do Colo/patologia , Doença de Crohn/patologia , Feminino , Fibrose/metabolismo , Fibrose/patologia , Humanos , Técnicas Imunoenzimáticas , Imunoprecipitação , Intestinos/citologia , Masculino , Pessoa de Meia-Idade , Miofibroblastos/citologia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Canais de Cátion TRPC/genética , Canal de Cátion TRPC6 , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo
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