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1.
Circ Res ; 128(5): 619-635, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33375812

RESUMO

RATIONALE: The mechanisms underlying atrial fibrillation (AF), the most common clinical arrhythmia, are poorly understood. Nucleoplasmic Ca2+ regulates gene expression, but the nature and significance of nuclear Ca2+-changes in AF are largely unknown. OBJECTIVE: To elucidate mechanisms by which AF alters atrial-cardiomyocyte nuclear Ca2+ ([Ca2+]Nuc) and CaMKII (Ca2+/calmodulin-dependent protein kinase-II)-related signaling. METHODS AND RESULTS: Atrial cardiomyocytes were isolated from control and AF dogs (kept in AF by atrial tachypacing [600 bpm × 1 week]). [Ca2+]Nuc and cytosolic [Ca2+] ([Ca2+]Cyto) were recorded via confocal microscopy. Diastolic [Ca2+]Nuc was greater than [Ca2+]Cyto under control conditions, while resting [Ca2+]Nuc was similar to [Ca2+]Cyto; both diastolic and resting [Ca2+]Nuc increased with AF. IP3R (Inositol-trisphosphate receptor) stimulation produced larger [Ca2+]Nuc increases in AF versus control cardiomyocytes, and IP3R-blockade suppressed the AF-related [Ca2+]Nuc differences. AF upregulated nuclear protein expression of IP3R1 (IP3R-type 1) and of phosphorylated CaMKII (immunohistochemistry and immunoblot) while decreasing the nuclear/cytosolic expression ratio for HDAC4 (histone deacetylase type-4). Isolated atrial cardiomyocytes tachypaced at 3 Hz for 24 hours mimicked AF-type [Ca2+]Nuc changes and L-type calcium current decreases versus 1-Hz-paced cardiomyocytes; these changes were prevented by IP3R knockdown with short-interfering RNA directed against IP3R1. Nuclear/cytosolic HDAC4 expression ratio was decreased by 3-Hz pacing, while nuclear CaMKII phosphorylation was increased. Either CaMKII-inhibition (by autocamtide-2-related peptide) or IP3R-knockdown prevented the CaMKII-hyperphosphorylation and nuclear-to-cytosolic HDAC4 shift caused by 3-Hz pacing. In human atrial cardiomyocytes from AF patients, nuclear IP3R1-expression was significantly increased, with decreased nuclear/nonnuclear HDAC4 ratio. MicroRNA-26a was predicted to target ITPR1 (confirmed by luciferase assay) and was downregulated in AF atrial cardiomyocytes; microRNA-26a silencing reproduced AF-induced IP3R1 upregulation and nuclear diastolic Ca2+-loading. CONCLUSIONS: AF increases atrial-cardiomyocyte nucleoplasmic [Ca2+] by IP3R1-upregulation involving miR-26a, leading to enhanced IP3R1-CaMKII-HDAC4 signaling and L-type calcium current downregulation. Graphic Abstract: A graphic abstract is available for this article.


Assuntos
Fibrilação Atrial/metabolismo , Cálcio/metabolismo , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Miócitos Cardíacos/metabolismo , Potenciais de Ação , Animais , Fibrilação Atrial/fisiopatologia , Canais de Cálcio Tipo L/metabolismo , Sinalização do Cálcio , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Núcleo Celular/metabolismo , Células Cultivadas , Cães , Histona Desacetilases/metabolismo , Humanos , Receptores de Inositol 1,4,5-Trifosfato/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Miócitos Cardíacos/fisiologia
2.
PLoS Comput Biol ; 17(6): e1009137, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34191797

RESUMO

The pig is commonly used as an experimental model of human heart disease, including for the study of mechanisms of arrhythmia. However, there exist differences between human and porcine cellular electrophysiology: The pig action potential (AP) has a deeper phase-1 notch, a longer duration at 50% repolarization, and higher plateau potentials than human. Ionic differences underlying the AP include larger rapid delayed-rectifier and smaller inward-rectifier K+-currents (IKr and IK1 respectively) in humans. AP steady-state rate-dependence and restitution is steeper in pigs. Porcine Ca2+ transients can have two components, unlike human. Although a reliable computational model for human ventricular myocytes exists, one for pigs is lacking. This hampers translation from results obtained in pigs to human myocardium. Here, we developed a computational model of the pig ventricular cardiomyocyte AP using experimental datasets of the relevant ionic currents, Ca2+-handling, AP shape, AP duration restitution, and inducibility of triggered activity and alternans. To properly capture porcine Ca2+ transients, we introduced a two-step process with a faster release in the t-tubular region, followed by a slower diffusion-induced release from a non t-tubular subcellular region. The pig model behavior was compared with that of a human ventricular cardiomyocyte (O'Hara-Rudy) model. The pig, but not the human model, developed early afterdepolarizations (EADs) under block of IK1, while IKr block led to EADs in the human but not in the pig model. At fast rates (pacing cycle length = 400 ms), the human cell model was more susceptible to spontaneous Ca2+ release-mediated delayed afterdepolarizations (DADs) and triggered activity than pig. Fast pacing led to alternans in human but not pig. Developing species-specific models incorporating electrophysiology and Ca2+-handling provides a tool to aid translating antiarrhythmic and arrhythmogenic assessment from the bench to the clinic.


Assuntos
Modelos Cardiovasculares , Miócitos Cardíacos/fisiologia , Potenciais de Ação , Animais , Arritmias Cardíacas/fisiopatologia , Sinalização do Cálcio , Biologia Computacional , Simulação por Computador , Fenômenos Eletrofisiológicos , Ventrículos do Coração/citologia , Humanos , Técnicas In Vitro , Modelos Animais , Técnicas de Patch-Clamp , Sus scrofa , Pesquisa Translacional Biomédica
3.
Diabetes Metab Res Rev ; 35(5): e3148, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30838734

RESUMO

Excessive adiposity and metabolic inflammation are the key risk factors of type 2 diabetes mellitus (T2DM). Juxtaposed with another zinc finger gene 1 (JAZF1) has been identified as a novel transcriptional cofactor, with function of regulating glucose and lipid homeostasis and inflammation. JAZF1 is involved in metabolic process of T2DM via interaction with several nuclear receptors and protein kinases. Additionally, increasing evidence from genome-wide association studies (GWAS) has shown that JAZF1 polymorphisms are closely associated with T2DM. In this review, we have updated the latest research advances on JAZF1 and discussed its regulatory network in T2DM. The association between JAZF1 polymorphisms and T2DM is discussed as well. The information provided is of importance for guiding future studies as well as for the design of JAZF1-based T2DM therapy.


Assuntos
Proteínas Correpressoras/fisiologia , Proteínas de Ligação a DNA/fisiologia , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Animais , Glicemia/metabolismo , Metabolismo dos Carboidratos/genética , Estudo de Associação Genômica Ampla , Humanos , Metabolismo dos Lipídeos/genética , Polimorfismo Genético , Fatores de Risco
4.
BMC Endocr Disord ; 19(1): 12, 2019 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-30670019

RESUMO

BACKGROUND: Zinc-α2-glycoprotein (ZAG) is a recently novel lipolytic adipokine implicated in regulation of glucose and lipid metabolism in many metabolic disorders. In vitro and animal studies suggest that thyroid hormones (TH) up-regulates ZAG production in hepatocytes. However, there is no data evaluating the possible relationship between ZAG and TH in a human model of hyperthyroidism. The objective of the present study is to assess the association of serum ZAG levels with TH and lipid profile in patients with hyperthyroidism before and after methimazole treatment. METHODS: A total of 120 newly diagnosed overt hyperthyroidism and 122 healthy control subjects were recruited. Of them, 39 hyperthyroidism patients were assigned to receive methimazole treatment as follow-up study for 2 months. RESULTS: The clinical consequence showed that serum ZAG levels were elevated in patients with hyperthyroidism (P < 0.01). Adjust for age, gender and BMI, serum ZAG levels were positively related with serum free T3 (FT3), free T4 (FT4) levels and negatively correlated with serum total cholesterol (TC), low density lipoprotein cholesterol (LDLC) levels in hyperthyroidism subjects (all P < 0.01). After methimazole treatment, serum ZAG levels were decreased and the decline was associated with decreased FT3, FT4 and increased TC levels (all P < 0.001). CONCLUSION: We conclude that ZAG may be involved in the pathogenesis of lipid metabolism disorder in patients with hyperthyroidism. TRIAL REGISTRATION: ChiCTR-ROC-17012943 . Registered 11 October 2017, retrospectively registered.


Assuntos
Biomarcadores/sangue , Hipertireoidismo/sangue , Metimazol/uso terapêutico , Proteínas de Plasma Seminal/sangue , Hormônios Tireóideos/sangue , Adulto , Antitireóideos/uso terapêutico , Feminino , Seguimentos , Humanos , Hipertireoidismo/diagnóstico , Hipertireoidismo/tratamento farmacológico , Masculino , Prognóstico , Estudos Prospectivos , Glicoproteína Zn-alfa-2
5.
Biochem Biophys Res Commun ; 496(2): 287-293, 2018 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29317208

RESUMO

Recent studies have highlighted recruiting and activating brite adipocytes in WAT (so-called "browning") would be an attractive anti-obesity strategy. Zinc alpha2 glycoprotein (ZAG) as an important adipokine, is reported to ameliorate glycolipid metabolism and lose body weight in obese mice. However whether the body reducing effect mediated by browning programme remains unclear. Here, we show that overexpression of ZAG in 3T3-L1 adipocytes enhanced expression of brown fat-specific markers (UCP-1, PRDM16 and CIDEA), mitochondrial biogenesis genes (PGC-1α, NRF-1/2 and mtTFA) and the key lipid metabolism lipases (ATGL, HSL, CPT1-A and p-acyl-CoA carboxylase). Additionally, those effects were dramaticlly abolished by H89/SB203580, revealing ZAG-induced browning depend on PKA and p38 MAPK signaling. Overall, our findings suggest that ZAG is a candidate therapeutic agent against obesity via induction of brown fat-like phenotype in white adipocytes.


Assuntos
Adipócitos Marrons/metabolismo , Proteínas de Transporte/genética , Regulação da Expressão Gênica , Glicoproteínas/genética , Metabolismo dos Lipídeos/genética , Células 3T3-L1 , Adipócitos Marrons/citologia , Adipócitos Marrons/efeitos dos fármacos , Adipocinas , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Carbono-Carbono Ligases/genética , Carbono-Carbono Ligases/metabolismo , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Proteínas de Transporte/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/genética , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Glicoproteínas/metabolismo , Imidazóis/farmacologia , Isoquinolinas/farmacologia , Lipase/genética , Lipase/metabolismo , Camundongos , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Fator 1 Nuclear Respiratório/genética , Fator 1 Nuclear Respiratório/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Piridinas/farmacologia , Transdução de Sinais , Sulfonamidas/farmacologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
6.
Int J Obes (Lond) ; 42(8): 1418-1430, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30006580

RESUMO

BACKGROUND/AIM: Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis, impaired insulin sensitivity, and chronic low-grade inflammation. Our previous studies indicated that zinc alpha2 glycoprotein (ZAG) alleviates palmitate (PA)-induced intracellular lipid accumulation in hepatocytes. This study is to further characterize the roles of ZAG on the development of hepatic steatosis, insulin resistance (IR), and inflammation. METHODS: ZAG protein levels in the livers of NAFLD patients, high-fat diet (HFD)-induced or genetically (ob/ob) induced obese mice, and in PA-treated hepatocytes were determined by western blotting. C57BL/6J mice injected with an adenovirus expressing ZAG were fed HFD for indicated time to induce hepatic steatosis, IR, and inflammation, and then biomedical, histological, and metabolic analyses were conducted to identify pathologic alterations in these mice. The molecular mechanisms underlying ZAG-regulated hepatic steatosis were further explored and verified in mice and hepatocytes. RESULTS: ZAG expression was decreased in NAFLD patient liver biopsy samples, obese mice livers, and PA-treated hepatocytes. Simultaneously, ZAG overexpression alleviated intracellular lipid accumulation via upregulating adiponectin and lipolytic genes (FXR, PPARα, etc.) while downregulating lipogenic genes (SREBP-1c, LXR, etc.) in obese mice as well as in cultured hepatocytes. ZAG improved insulin sensitivity and glucose tolerance via activation of IRS/AKT signaling. Moreover, ZAG significantly inhibited NF-ĸB/JNK signaling and thus resulting in suppression of obesity-associated inflammatory response in hepatocytes. CONCLUSIONS: Our results revealed that ZAG could protect against NAFLD by ameliorating hepatic steatosis, IR, and inflammation.


Assuntos
Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/metabolismo , Proteínas de Plasma Seminal/metabolismo , Animais , Humanos , Fígado/química , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Proteínas de Plasma Seminal/análise , Proteínas de Plasma Seminal/genética , Transdução de Sinais/genética , Regulação para Cima/genética , Glicoproteína Zn-alfa-2
7.
Cardiovasc Diabetol ; 17(1): 134, 2018 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-30305178

RESUMO

Perivascular adipose tissue (PVAT), the adipose tissue that surrounds most of the vasculature, has emerged as an active component of the blood vessel wall regulating vascular homeostasis and affecting the pathogenesis of atherosclerosis. Although PVAT characteristics resemble both brown and white adipose tissues, recent evidence suggests that PVAT develops from its own distinct precursors implying a closer link between PVAT and vascular system. Under physiological conditions, PVAT has potent anti-atherogenic properties mediated by its ability to secrete various biologically active factors that induce non-shivering thermogenesis and metabolize fatty acids. In contrast, under pathological conditions (mainly obesity), PVAT becomes dysfunctional, loses its thermogenic capacity and secretes pro-inflammatory adipokines that induce endothelial dysfunction and infiltration of inflammatory cells, promoting atherosclerosis development. Since PVAT plays crucial roles in regulating key steps of atherosclerosis development, it may constitute a novel therapeutic target for the prevention and treatment of atherosclerosis. Here, we review the current literature regarding the roles of PVAT in the pathogenesis of atherosclerosis.


Assuntos
Adipocinas/metabolismo , Tecido Adiposo/metabolismo , Aterosclerose/metabolismo , Vasos Sanguíneos/metabolismo , Mediadores da Inflamação/metabolismo , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/patologia , Tecido Adiposo/fisiopatologia , Adiposidade , Animais , Anti-Inflamatórios/uso terapêutico , Aterosclerose/patologia , Aterosclerose/fisiopatologia , Aterosclerose/prevenção & controle , Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/patologia , Vasos Sanguíneos/fisiopatologia , Fármacos Cardiovasculares/uso terapêutico , Metabolismo Energético , Humanos , Fatores de Proteção , Fatores de Risco , Transdução de Sinais , Termogênese
8.
Circ Res ; 116(5): 836-45, 2015 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-25608527

RESUMO

RATIONALE: Fibroblasts are involved in cardiac arrhythmogenesis and contribute to the atrial fibrillation substrate in congestive heart failure (CHF) by generating tissue fibrosis. Fibroblasts display robust ion currents, but their functional importance is poorly understood. OBJECTIVE: To characterize atrial fibroblast inward-rectifier K(+) current (IK1) remodeling in CHF and its effects on fibroblast properties. METHODS AND RESULTS: Freshly isolated left atrial fibroblasts were obtained from controls and dogs with CHF (ventricular tachypacing). Patch clamp was used to record resting membrane potential (RMP) and IK1. RMP was significantly increased by CHF (from -43.2±0.8 mV, control, to -55.5±0.9 mV). CHF upregulated IK1 (eg, at -90 mV from -1.1±0.2 to -2.7±0.5 pA/pF) and increased the expression of KCNJ2 mRNA (by 52%) and protein (by 80%). Ba(2+) (300 µmol/L) decreased the RMP and suppressed the RMP difference between controls and dogs with CHF. Store-operated Ca(2+) entry (Fura-2-acetoxymethyl ester) and fibroblast proliferation (flow cytometry) were enhanced by CHF. Lentivirus-mediated overexpression of KCNJ2 enhanced IK1 and hyperpolarized fibroblasts. Functional KCNJ2 suppression by lentivirus-mediated expression of a dominant negative KCNJ2 construct suppressed IK1 and depolarized RMP. Overexpression of KCNJ2 increased Ca(2+) entry and fibroblast proliferation, whereas the dominant negative KCNJ2 construct had opposite effects. Fibroblast hyperpolarization to mimic CHF effects on RMP enhanced the Ca(2+) entry. MicroRNA-26a, which targets KCNJ2, was downregulated in CHF fibroblasts. Knockdown of endogenous microRNA-26 to mimic CHF effects unregulated IK1. CONCLUSIONS: CHF upregulates fibroblast KCNJ2 expression and currents, thereby hyperpolarizing RMP, increasing Ca(2+) entry, and enhancing atrial fibroblast proliferation. These effects are likely mediated by microRNA-26a downregulation. Remodeling-induced fibroblast KCNJ2 expression changes may play a role in atrial fibrillation promoting fibroblast remodeling and structural/arrhythmic consequences.


Assuntos
Fibrilação Atrial/etiologia , Remodelamento Atrial/fisiologia , Fibroblastos/metabolismo , Insuficiência Cardíaca/complicações , MicroRNAs/fisiologia , Canais de Potássio Corretores do Fluxo de Internalização/fisiologia , Potássio/metabolismo , Animais , Fibrilação Atrial/metabolismo , Fibrilação Atrial/patologia , Cálcio/metabolismo , Estimulação Cardíaca Artificial , Ciclo Celular , Divisão Celular , Cães , Feminino , Fibroblastos/patologia , Fibrose , Regulação da Expressão Gênica , Genes Reporter , Insuficiência Cardíaca/fisiopatologia , Transporte de Íons , Masculino , Potenciais da Membrana/fisiologia , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Técnicas de Patch-Clamp , Proteínas Recombinantes de Fusão/metabolismo , Transdução Genética , Regulação para Cima
9.
Zhongguo Zhong Yao Za Zhi ; 42(21): 4110-4114, 2017 Nov.
Artigo em Zh | MEDLINE | ID: mdl-29271147

RESUMO

Cervi Cornu Pantotrichum, as a traditional Chinese medicine, has great potential for development. However, the identification and quality control system is not perfect, leading to the market chaos and chronic slow growth in deep processing of Cervi Cornu Pantotrichum. This paper gives an overview of present situation in identification and quality control system of the Cervi Cornu Pantotrichum, and analyzes present problems. Based on these results, the feasibility study scheme in identification and quality control system for Cervi Cornu Pantotrichum would be then put forward, providing ideas to establish its comprehensive evaluation system.


Assuntos
Chifres de Veado/química , Materia Medica/normas , Animais , Cervos , Materia Medica/química , Medicina Tradicional Chinesa , Controle de Qualidade , Pesquisa
10.
Circulation ; 132(23): 2203-11, 2015 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-26499964

RESUMO

BACKGROUND: The development of effective and safe antiarrhythmic drugs for atrial fibrillation (AF) rhythm control is an unmet clinical need. Multichannel blockers are believed to have advantages over single-channel blockers for AF, but their development has been completely empirical to date. We tested the hypothesis that adding K(+)-channel blockade improves the atrium-selective electrophysiological profile and anti-AF effects of optimized Na(+)-channel blockers. METHODS AND RESULTS: Realistic cardiomyocyte-, tissue-, and state-dependent Na(+)-channel block mathematical models, optical mapping, and action potential recording were used to study the effect of Na(+)-current (INa) blockade with or without concomitant inhibition of the rapid or ultrarapid delayed-rectifier K(+) currents (IKr and IKur, respectively). In the mathematical model, maximal AF selectivity was obtained with an inactivated-state Na(+)-channel blocker. Combining optimized Na(+)-channel blocker with IKr block increased rate-dependent and atrium-selective peak INa reduction, increased AF selectivity, and more effectively terminated AF compared with optimized Na(+)-channel blocker alone. Combining optimized Na(+)-channel blocker with IKur block had similar effects but without IKr block-induced ventricular action potential prolongation. Consistent with the mathematical model, in coronary-perfused canine hearts, the addition of dofetilide (selective IKr blocker) to pilsicainide (selective INa blocker) produced enhanced atrium-selective effects on maximal phase 0 upstroke and conduction velocity. Furthermore, pilsicainide plus dofetilide had higher AF termination efficacy than pilsicainide alone. Pilsicainide alone had no statistically significant effect on AF inducibility, whereas pilsicainide plus dofetilide rendered AF noninducible. CONCLUSIONS: K(+)-channel block potentiates the AF-selective anti-AF effects obtainable with optimized Na(+)-channel blockade. Combining optimized Na(+)-channel block with blockade of atrial K(+) currents is a potentially valuable AF-selective antiarrhythmic drug strategy.


Assuntos
Antiarrítmicos/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Bloqueadores dos Canais de Potássio/uso terapêutico , Bloqueadores dos Canais de Sódio/uso terapêutico , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Antiarrítmicos/farmacologia , Fibrilação Atrial/fisiopatologia , Cães , Bloqueadores dos Canais de Potássio/farmacologia , Bloqueadores dos Canais de Sódio/farmacologia
11.
Circ Res ; 114(6): 993-1003, 2014 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-24508724

RESUMO

RATIONALE: ß-Adrenoceptor activation contributes to sudden death risk in heart failure. Chronic ß-adrenergic stimulation, as occurs in patients with heart failure, causes potentially arrhythmogenic reductions in slow delayed-rectifier K(+) current (IKs). OBJECTIVE: To assess the molecular mechanisms of IKs downregulation caused by chronic ß-adrenergic activation, particularly the role of exchange protein directly activated by cAMP (Epac). METHODS AND RESULTS: Isolated guinea pig left ventricular cardiomyocytes were incubated in primary culture and exposed to isoproterenol (1 µmol/L) or vehicle for 30 hours. Sustained isoproterenol exposure decreased IKs density (whole cell patch clamp) by 58% (P<0.0001), with corresponding decreases in potassium voltage-gated channel subfamily E member 1 (KCNE1) mRNA and membrane protein expression (by 45% and 51%, respectively). Potassium voltage-gated channel, KQT-like subfamily, member 1 (KCNQ1) mRNA expression was unchanged. The ß1-adrenoceptor antagonist 1-[2-((3-Carbamoyl-4-hydroxy)phenoxy)ethylamino]-3-[4-(1-methyl-4-trifluoromethyl-2-imidazolyl)phenoxy]-2-propanol dihydrochloride (CGP-20712A) prevented isoproterenol-induced IKs downregulation, whereas the ß2-antagonist ICI-118551 had no effect. The selective Epac activator 8-pCPT-2'-O-Me-cAMP decreased IKs density to an extent similar to isoproterenol exposure, and adenoviral-mediated knockdown of Epac1 prevented isoproterenol-induced IKs/KCNE1 downregulation. In contrast, protein kinase A inhibition with a cell-permeable highly selective peptide blocker did not affect IKs downregulation. 1,2-Bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetate-AM acetoxymethyl ester (BAPTA-AM), cyclosporine, and inhibitor of nuclear factor of activated T cell (NFAT)-calcineurin association-6 (INCA6) prevented IKs reduction by isoproterenol and INCA6 suppressed isoproterenol-induced KCNE1 downregulation, consistent with signal-transduction via the Ca(2+)/calcineurin/NFAT pathway. Isoproterenol induced nuclear NFATc3/c4 translocation (immunofluorescence), which was suppressed by Epac1 knockdown. Chronic in vivo administration of isoproterenol to guinea pigs reduced IKs density and KCNE1 mRNA and protein expression while inducing cardiac dysfunction and action potential prolongation. Selective in vivo activation of Epac via sp-8-pCPT-2'-O-Me-cAMP infusion decreased IKs density and KCNE1 mRNA/protein expression. CONCLUSIONS: Prolonged ß1-adrenoceptor stimulation suppresses IKs by downregulating KCNE1 mRNA and protein via Epac-mediated Ca(2+)/calcineurin/NFAT signaling. These results provide new insights into the molecular basis of K(+) channel remodeling under sustained adrenergic stimulation.


Assuntos
Agonistas Adrenérgicos beta/toxicidade , Canais de Potássio de Retificação Tardia/metabolismo , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Ativação do Canal Iônico/efeitos dos fármacos , Isoproterenol/toxicidade , Receptores Adrenérgicos beta 1/fisiologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Calcineurina/fisiologia , Cálcio/farmacologia , Células Cultivadas , Colforsina/farmacologia , AMP Cíclico/análogos & derivados , AMP Cíclico/farmacologia , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Fatores de Troca do Nucleotídeo Guanina/antagonistas & inibidores , Fatores de Troca do Nucleotídeo Guanina/genética , Cobaias , Hipertrofia Ventricular Esquerda/etiologia , Imidazóis/farmacologia , Ativação do Canal Iônico/fisiologia , Isoproterenol/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Fatores de Transcrição NFATC/metabolismo , Técnicas de Patch-Clamp , Potássio/metabolismo , Propanolaminas/farmacologia , Interferência de RNA , RNA Interferente Pequeno/farmacologia , Receptores Adrenérgicos beta 1/efeitos dos fármacos , Sistemas do Segundo Mensageiro/efeitos dos fármacos , Sistemas do Segundo Mensageiro/fisiologia
12.
Circulation ; 129(4): 430-40, 2014 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-24190961

RESUMO

BACKGROUND: Recent evidence points to functional Ca²âº-dependent K⁺ (SK) channels in the heart that may govern atrial fibrillation (AF) risk, but the underlying mechanisms are unclear. This study addressed the role of SK channels in atrial repolarization and AF persistence in a canine AF model. METHODS AND RESULTS: Electrophysiological variables were assessed in dogs subjected to atrial remodeling by 7-day atrial tachypacing (AT-P), as well as controls. Ionic currents and single-channel properties were measured in isolated canine atrial cardiomyocytes by patch clamp. NS8593, a putative selective SK blocker, suppressed SK current with an IC50 of ≈5 µmol/L, without affecting Na⁺, Ca²âº, or other K⁺ currents. Whole-cell SK current sensitive to NS8593 was significantly larger in pulmonary vein (PV) versus left atrial (LA) cells, without a difference in SK single-channel open probability (P(o)), whereas AT-P enhanced both whole-cell SK currents and single-channel P(o). SK-current block increased action potential duration in both PV and LA cells after AT-P; but only in PV cells in absence of AT-P. SK2 expression was more abundant at both mRNA and protein levels for PV versus LA in control dogs, in both control and AT-P; AT-P upregulated only SK1 at the protein level. Intravenous administration of NS8593 (5 mg/kg) significantly prolonged atrial refractoriness and reduced AF duration without affecting the Wenckebach cycle length, left ventricular refractoriness, or blood pressure. CONCLUSIONS: SK currents play a role in canine atrial repolarization, are larger in PVs than LA, are enhanced by atrial-tachycardia remodeling, and appear to participate in promoting AF maintenance. These results are relevant to the potential mechanisms underlying the association between SK single-nucleotide polymorphisms and AF and suggest SK blockers as potentially interesting anti-AF drugs.


Assuntos
Fibrilação Atrial/patologia , Fibrilação Atrial/fisiopatologia , Fenômenos Eletrofisiológicos/fisiologia , Canais de Potássio Ativados por Cálcio de Condutância Baixa/fisiologia , 1-Naftilamina/análogos & derivados , 1-Naftilamina/farmacologia , Animais , Modelos Animais de Doenças , Cães , Técnicas Eletrofisiológicas Cardíacas , Átrios do Coração/efeitos dos fármacos , Átrios do Coração/patologia , Miócitos Cardíacos/patologia , Miócitos Cardíacos/fisiologia , Técnicas de Patch-Clamp , Bloqueadores dos Canais de Potássio/farmacologia , Veias Pulmonares/efeitos dos fármacos , Veias Pulmonares/patologia , Canais de Potássio Ativados por Cálcio de Condutância Baixa/efeitos dos fármacos
13.
Biophys J ; 107(10): 2444-55, 2014 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-25418313

RESUMO

Fibroblasts are activated in heart failure (HF) and produce fibrosis, which plays a role in maintaining atrial fibrillation (AF). The effect of HF on fibroblast ion currents and its potential role in AF are unknown. Here, we used a patch-clamp technique to investigate the effects of HF on atrial fibroblast ion currents, and mathematical computation to assess the potential impact of this remodeling on atrial electrophysiology and arrhythmogenesis. Atrial fibroblasts were isolated from control and tachypacing-induced HF dogs. Tetraethylammonium-sensitive voltage-gated fibroblast current (IKv,fb) was significantly downregulated (by ?44%), whereas the Ba(2+)-sensitive inward rectifier current (IKir,fb) was upregulated by 79%, in HF animals versus controls. The fibroblast resting membrane potential was hyperpolarized (?53 ± 2 mV vs. ?42 ± 2 mV in controls) and the capacitance was increased (29.7 ± 2.2 pF vs. 17.8 ± 1.4 pF in controls) in HF. These experimental findings were implemented in a mathematical model that included cardiomyocyte-fibroblast electrical coupling. IKir,fb upregulation had a profibrillatory effect through shortening of the action potential duration and hyperpolarization of the cardiomyocyte resting membrane potential. IKv,fb downregulation had the opposite electrophysiological effects and was antifibrillatory. Simulated pharmacological blockade of IKv,fb successfully terminated reentry under otherwise profibrillatory conditions. We conclude that HF induces fibroblast ion-current remodeling with IKv,fb downregulation and IKir,fb upregulation, and that, assuming cardiomyocyte-fibroblast electrical coupling, this remodeling has a potentially important effect on atrial electrophysiology and arrhythmogenesis, with the overall response depending on the balance of pro- and antifibrillatory contributions. These findings suggest that fibroblast K(+)-current remodeling is a novel component of AF-related remodeling that might contribute to arrhythmia dynamics.


Assuntos
Fibrilação Atrial/patologia , Fibrilação Atrial/fisiopatologia , Remodelamento Atrial , Fibroblastos/patologia , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Animais , Cães , Fenômenos Eletrofisiológicos , Potenciais da Membrana , Modelos Biológicos , Miócitos Cardíacos/patologia
14.
Circulation ; 127(14): 1466-75, 1475e1-28, 2013 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-23459615

RESUMO

BACKGROUND: Congestive heart failure (CHF) causes atrial fibrotic remodeling, a substrate for atrial fibrillation (AF) maintenance. MicroRNA29 (miR29) targets extracellular matrix proteins. In the present study, we examined miR29b changes in patients with AF and/or CHF and in a CHF-related AF animal model and assessed its potential role in controlling atrial fibrous tissue production. METHODS AND RESULTS: Control dogs were compared with dogs subjected to ventricular tachypacing for 24 hours, 1 week, or 2 weeks to induce CHF. Atrial miR29b expression decreased within 24 hours in both whole atrial tissue and atrial fibroblasts (-87% and -92% versus control, respectively; p<0.001 for both) and remained decreased throughout the time course. Expression of miR29b extracellular matrix target genes collagen-1A1 (COL1A1), collagen-3A1 (COL3A1), and fibrillin increased significantly in CHF fibroblasts. Lentivirus-mediated miR29b knockdown in canine atrial fibroblasts (-68%; p<0.01) enhanced COL1A1, COL3A1, and fibrillin mRNA expression by 28% (p<0.01), 19% (p<0.05), and 20% (p<0.05), respectively, versus empty virus-infected fibroblasts and increased COL1A1 protein expression by 90% (p<0.05). In contrast, 3-fold overexpression of miR29b decreased COL1A1, COL3A1, and fibrillin mRNA by 65%, 62%, and 61% (all p<0.001), respectively, versus scrambled control and decreased COL1A1 protein by 60% (p<0.05). MiR29b plasma levels were decreased in patients with CHF or AF (by 53% and 54%, respectively; both p<0.001) and were further decreased in patients with both AF and CHF (by 84%; p<0.001). MiR29b expression was also reduced in the atria of chronic AF patients (by 54% versus sinus rhythm; p<0.05). Adenoassociated viral-mediated knockdown of miR29b in mice significantly increased atrial COL1A1 mRNA expression and cardiac tissue collagen content. CONCLUSIONS: MiR29 likely plays a role in atrial fibrotic remodeling and may have value as a biomarker and/or therapeutic target.


Assuntos
Fibrilação Atrial/genética , Fibrilação Atrial/fisiopatologia , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/fisiopatologia , MicroRNAs/genética , Idoso , Animais , Fibrilação Atrial/patologia , Biomarcadores/sangue , Modelos Animais de Doenças , Cães , Feminino , Fibrose/genética , Fibrose/patologia , Fibrose/fisiopatologia , Átrios do Coração/metabolismo , Átrios do Coração/patologia , Átrios do Coração/fisiopatologia , Insuficiência Cardíaca/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/sangue , Pessoa de Meia-Idade , Miocárdio/metabolismo , Miocárdio/patologia , Marca-Passo Artificial , Remodelação Ventricular/genética , Remodelação Ventricular/fisiologia
15.
Aust J Rural Health ; 22(5): 264-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25303419

RESUMO

OBJECTIVE: The present article aimed to explore and evaluate the epidemiology and determine the status of hypertension awareness, treatment and control in Henan province, China. DESIGN: Cross-sectional survey. SETTING: Thirty counties in Henan province of China. PARTICIPANTS: There were 18 772 randomly selected 15-74 years old. MAIN OUTCOME MEASURES: The distribution of blood pressure and prevalence, awareness, treatment and control of hypertension based on automated electronic monitor and questionnaire. RESULTS: The crude prevalence of hypertension was 24.9%, and the standardised rate was 26.6%, meaning about 25 million were hypertensive in Henan province. Of which, 46% were aware of their hypertension diagnosis, 35.7% were having antihypertensive medicine, only 10.4% had their blood pressure controlled less than 140/90 mmHg, and 29.1% were being controlled when they were having antihypertensive medicine. CONCLUSIONS: Hypertension is highly prevalent in Henan province, but the levels of hypertension awareness, treatment and control are low. Therefore, necessary actions including prevention, detection and treatment must be taken to keep the situation from worsening.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Hipertensão/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea , Índice de Massa Corporal , China/epidemiologia , Estudos Transversais , Humanos , Hipertensão/tratamento farmacológico , Hipertensão/prevenção & controle , Pessoa de Meia-Idade , Prevalência , Fatores Sexuais , Inquéritos e Questionários , Adulto Jovem
16.
World J Clin Cases ; 12(21): 4558-4565, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39070847

RESUMO

BACKGROUND: Joint replacement is a common treatment for older patients with high incidences of hip joint diseases. However, postoperative recovery is slow and complications are common, which reduces surgical effectiveness. Therefore, patients require long-term, high-quality, and effective nursing interventions to promote rehabilitation. Continuity of care has been used successfully in other diseases; however, little research has been conducted on older patients who have undergone hip replacement. AIM: To explore the clinical effect of continuous nursing on rehabilitation after discharge of older individuals who have undergone joint replacement. METHODS: A retrospective analysis was performed on the clinical data of 113 elderly patients. Patients receiving routine nursing were included in the convention group (n = 60), and those receiving continuous nursing, according to various methods, were included in the continuation group (n = 53). Harris score, short form 36 (SF-36) score, complication rate, and readmission rate were compared between the convention and continuation groups. RESULTS: After discharge, Harris and SF-36 scores of the continuation group were higher than those of the convention group. The Harris and SF-36 scores of the two groups showed an increasing trend with time, and there was an interaction effect between group and time (Harris score: F intergroup effect = 376.500, F time effect = 20.090, F interaction effect = 4.824; SF-36 score: F intergroup effect = 236.200, F time effect = 16.710, F interaction effect = 5.584; all P < 0.05). Furthermore, the total complication and readmission rates in the continuation group were lower (P < 0.05). CONCLUSION: Continuous nursing could significantly improve hip function and quality of life in older patients after joint replacement and reduce the incidence of complications and readmission rates.

17.
Circulation ; 126(17): 2051-64, 2012 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-22992321

RESUMO

BACKGROUND: Fibroblast proliferation and differentiation are central in atrial fibrillation (AF)-promoting remodeling. Here, we investigated fibroblast regulation by Ca(2+)-permeable transient receptor potential canonical-3 (TRPC3) channels. METHODS AND RESULTS: Freshly isolated rat cardiac fibroblasts abundantly expressed TRPC3 and had appreciable nonselective cation currents (I(NSC)) sensitive to a selective TPRC3 channel blocker, pyrazole-3 (3 µmol/L). Pyrazole-3 suppressed angiotensin II-induced Ca(2+) influx, proliferation, and α-smooth muscle actin protein expression in fibroblasts. Ca(2+) removal and TRPC3 blockade suppressed extracellular signal-regulated kinase phosphorylation, and extracellular signal-regulated kinase phosphorylation inhibition reduced fibroblast proliferation. TRPC3 expression was upregulated in atria from AF patients, goats with electrically maintained AF, and dogs with tachypacing-induced heart failure. TRPC3 knockdown (based on short hairpin RNA [shRNA]) decreased canine atrial fibroblast proliferation. In left atrial fibroblasts freshly isolated from dogs kept in AF for 1 week by atrial tachypacing, TRPC3 protein expression, currents, extracellular signal-regulated kinase phosphorylation, and extracellular matrix gene expression were all significantly increased. In cultured left atrial fibroblasts from AF dogs, proliferation rates, α-smooth muscle actin expression, and extracellular signal-regulated kinase phosphorylation were increased and were suppressed by pyrazole-3. MicroRNA-26 was downregulated in canine AF atria; experimental microRNA-26 knockdown reproduced AF-induced TRPC3 upregulation and fibroblast activation. MicroRNA-26 has NFAT (nuclear factor of activated T cells) binding sites in the 5' promoter region. NFAT activation increased in AF fibroblasts, and NFAT negatively regulated microRNA-26 transcription. In vivo pyrazole-3 administration suppressed AF while decreasing fibroblast proliferation and extracellular matrix gene expression. CONCLUSIONS: TRPC3 channels regulate cardiac fibroblast proliferation and differentiation, likely by controlling the Ca(2+) influx that activates extracellular signal-regulated kinase signaling. AF increases TRPC3 channel expression by causing NFAT-mediated downregulation of microRNA-26 and causes TRPC3-dependent enhancement of fibroblast proliferation and differentiation. In vivo, TRPC3 blockade prevents AF substrate development in a dog model of electrically maintained AF. TRPC3 likely plays an important role in AF by promoting fibroblast pathophysiology and is a novel potential therapeutic target.


Assuntos
Fibrilação Atrial/metabolismo , Fibrilação Atrial/patologia , Fibroblastos/metabolismo , Canais de Cátion TRPC/fisiologia , Animais , Fibrilação Atrial/genética , Função do Átrio Direito/genética , Proliferação de Células , Células Cultivadas , Cães , Regulação para Baixo/genética , Fibroblastos/patologia , Técnicas de Silenciamento de Genes/métodos , Cabras , Células HEK293 , Humanos , Ratos , Canais de Cátion TRPC/genética
18.
Am J Physiol Renal Physiol ; 304(7): F849-62, 2013 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-23389455

RESUMO

Glomerulosclerosis is featured by accumulation of the extracellular matrixes in the glomerulus. We showed previously that activation of the small GTPase RhoA in podocytes induces heavy proteinuria and glomerulosclerosis in the mouse. In the current study, we investigated the mechanism by which RhoA stimulates the production of one of the extracellular matrixes, fibronectin, by podocytes, specifically testing the role of nuclear factor of activated T cells (NFAT). Expression of constitutively active RhoA in cultured podocytes activated the fibronectin promoter, upregulated fibronectin protein, and activated NFAT. Expression of constitutively active NFAT in podocytes also activated the fibronectin promoter and upregulated fibronectin protein. RhoA-induced NFAT activation and fibronectin upregulation were both dependent on the calcium/calmodulin pathway and Rho kinase. NFAT activation was also observed in vivo in the rat and mouse models of podocyte injury and proteinuria, and NFAT inhibition ameliorated fibronectin upregulation in the latter. RhoA activation induced a rise of intracellular calcium ion concentration ([Ca(2+)]i), which was at least in part dependent on the transient receptor potential canonical 6 (TRPC6) cation channel. The results indicate that RhoA activates NFAT by inducing a rise of [Ca(2+)]i in podocytes, which in turn contributes to fibronectin upregulation. This pathway may be responsible for the pathogenesis of certain glomerular diseases such as hypertension-mediated glomerulosclerosis.


Assuntos
Fibronectinas/biossíntese , Fatores de Transcrição NFATC/metabolismo , Podócitos/metabolismo , Proteína rhoA de Ligação ao GTP/genética , Animais , Cálcio/metabolismo , Fibronectinas/metabolismo , Camundongos , Ratos , Canais de Cátion TRPC/genética , Canais de Cátion TRPC/fisiologia , Canal de Cátion TRPC6 , Regulação para Cima
19.
Food Chem ; 409: 135284, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-36586265

RESUMO

To investigate the effects of mixed fermentation with T. delbrueckii on aroma profiles of blueberry fermented beverage, five fermentations were conducted: monoculture of T. delbrueckii and S. cerevisiae, respectively; co-inoculation of two strains; sequential inoculation of two strains at time intervals of 24 h and 48 h, respectively. Compared with pure S. cerevisiae fermentation, ethanol level was decreased by up to 1.1% vol., while total anthocyanins were increased by 27.7%-85.0% in mixed fermentations. Marker aroma compounds in different fermentations with relative odor activity values higher than 1were identified. T. delbrueckii significantly decreased volatile acid content (especially acetic acid) by 22.2%-83.3%. Ethyl 3-methylbutanoate, ethyl hexanoate and ethyl octanoate, in pure T. delbrueckii fermentation were significantly decreased, while their concentrations were increased by 1.6-4.4 folds in sequential fermentations. Besides, linalool, rose oxide, benzeneacetaldehyde were significantly increased by sequential fermentation, which was associated with the enhancement of fruity and sweet notes.


Assuntos
Mirtilos Azuis (Planta) , Torulaspora , Vinho , Saccharomyces cerevisiae/metabolismo , Torulaspora/metabolismo , Vinho/análise , Mirtilos Azuis (Planta)/metabolismo , Antocianinas/metabolismo , Fermentação , Ácido Acético
20.
Genes Dis ; 10(3): 799-812, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37396503

RESUMO

Obesity plays a crucial role in the development of non-alcoholic fatty liver disease (NAFLD). However, the underlying mechanism for the pathogenesis of obesity-associated NAFLD remains largely obscure. Although the "multiple hit" theory provides a more accurate explanation of NAFLD pathogenesis, it still cannot fully explain precisely how obesity causes NAFLD. The liver is the key integrator of the body's energy needs, receiving input from multiple metabolically active organs. Thus, recent studies have advocated the "multiple crosstalk" hypothesis, highlighting that obesity-related hepatic steatosis may be the result of dysregulated "crosstalk" among multiple extra-hepatic organs and the liver in obesity. A wide variety of circulating endocrine hormones work together to orchestrate this "crosstalk". Of note, with deepening understanding of the endocrine system, the perception of hormones has gradually risen from the narrow sense (i.e. traditional hormones) to the broad sense of hormones as organokines and exosomes. In this review, we focus on the perspective of organic endocrine hormones (organokines) and molecular endocrine hormones (exosomes), summarizing systematically how the two types of new hormones mediate the dialogue between extra-hepatic organs and liver in the pathogenesis of obesity-related NAFLD.

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