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1.
JACC Basic Transl Sci ; 9(8): 982-1001, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39297139

RESUMO

Phosphorylation of myofilament proteins critically regulates beat-to-beat cardiac contraction and is typically altered in heart failure (HF). ß-Adrenergic activation induces phosphorylation in numerous substrates at the myofilament. Nevertheless, how cardiac ß-adrenoceptors (ßARs) signal to the myofilament in healthy and diseased hearts remains poorly understood. The aim of this study was to uncover the spatiotemporal regulation of local ßAR signaling at the myofilament and thus identify a potential therapeutic target for HF. Phosphoproteomic analysis of substrate phosphorylation induced by different ßAR ligands in mouse hearts was performed. Genetically encoded biosensors were used to characterize cyclic adenosine and guanosine monophosphate signaling and the impacts on excitation-contraction coupling induced by ß1AR ligands at both the cardiomyocyte and whole-heart levels. Myofilament signaling circuitry was identified, including protein kinase G1 (PKG1)-dependent phosphorylation of myosin light chain kinase, myosin phosphatase target subunit 1, and myosin light chain at the myofilaments. The increased phosphorylation of myosin light chain enhances cardiac contractility, with a minimal increase in calcium (Ca2+) cycling. This myofilament signaling paradigm is promoted by carvedilol-induced ß1AR-nitric oxide synthetase 3 (NOS3)-dependent cyclic guanosine monophosphate signaling, drawing a parallel to the ß1AR-cyclic adenosine monophosphate-protein kinase A pathway. In patients with HF and a mouse HF model of myocardial infarction, increasing expression and association of NOS3 with ß1AR were observed. Stimulating ß1AR-NOS3-PKG1 signaling increased cardiac contraction in the mouse HF model. This research has characterized myofilament ß1AR-PKG1-dependent signaling circuitry to increase phosphorylation of myosin light chain and enhance cardiac contractility, with a minimal increase in Ca2+ cycling. The present findings raise the possibility of targeting this myofilament signaling circuitry for treatment of patients with HF.

2.
J Am Heart Assoc ; 13(12): e033733, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38860414

RESUMO

BACKGROUND: Chronic sympathetic stimulation drives desensitization and downregulation of ß1 adrenergic receptor (ß1AR) in heart failure. We aim to explore the differential downregulation subcellular pools of ß1AR signaling in the heart. METHODS AND RESULTS: We applied chronic infusion of isoproterenol to induced cardiomyopathy in male C57BL/6J mice. We applied confocal and proximity ligation assay to examine ß1AR association with L-type calcium channel, ryanodine receptor 2, and SERCA2a ((Sarco)endoplasmic reticulum calcium ATPase 2a) and Förster resonance energy transfer-based biosensors to probe subcellular ß1AR-PKA (protein kinase A) signaling in ventricular myocytes. Chronic infusion of isoproterenol led to reduced ß1AR protein levels, receptor association with L-type calcium channel and ryanodine receptor 2 measured by proximity ligation (puncta/cell, 29.65 saline versus 14.17 isoproterenol, P<0.05), and receptor-induced PKA signaling at the plasma membrane (Förster resonance energy transfer, 28.9% saline versus 1.9% isoproterenol, P<0.05) and ryanodine receptor 2 complex (Förster resonance energy transfer, 30.2% saline versus 10.6% isoproterenol, P<0.05). However, the ß1AR association with SERCA2a was enhanced (puncta/cell, 51.4 saline versus 87.5 isoproterenol, P<0.05), and the receptor signal was minimally affected. The isoproterenol-infused hearts displayed decreased PDE4D (phosphodiesterase 4D) and PDE3A and increased PDE2A, PDE4A, and PDE4B protein levels. We observed a reduced role of PDE4 and enhanced roles of PDE2 and PDE3 on the ß1AR-PKA activity at the ryanodine receptor 2 complexes and myocyte shortening. Despite the enhanced ß1AR association with SERCA2a, the endogenous norepinephrine-induced signaling was reduced at the SERCA2a complexes. Inhibiting monoamine oxidase A rescued the norepinephrine-induced PKA signaling at the SERCA2a and myocyte shortening. CONCLUSIONS: This study reveals distinct mechanisms for the downregulation of subcellular ß1AR signaling in the heart under chronic adrenergic stimulation.


Assuntos
Canais de Cálcio Tipo L , Proteínas Quinases Dependentes de AMP Cíclico , Regulação para Baixo , Isoproterenol , Camundongos Endogâmicos C57BL , Miócitos Cardíacos , Receptores Adrenérgicos beta 1 , Canal de Liberação de Cálcio do Receptor de Rianodina , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático , Transdução de Sinais , Animais , Receptores Adrenérgicos beta 1/metabolismo , Masculino , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Isoproterenol/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Canais de Cálcio Tipo L/metabolismo , Canais de Cálcio Tipo L/efeitos dos fármacos , Modelos Animais de Doenças , Camundongos , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/induzido quimicamente , Insuficiência Cardíaca/fisiopatologia , Cardiomiopatias/metabolismo , Cardiomiopatias/induzido quimicamente , Transferência Ressonante de Energia de Fluorescência
3.
Cells ; 12(12)2023 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-37371137

RESUMO

Pathological cardiac hypertrophy is one of the notable causes of heart failure. Circular RNAs (circRNAs) have been studied in association with cardiac hypertrophy; however, the mechanisms by which circRNAs regulate cardiac hypertrophy remain unclear. In this study, we identified a new circRNA, named circCacna1c, in cardiac hypertrophy. Adult male C57BL/6 mice and H9c2 cells were treated with isoprenaline hydrochloride (ISO) to establish a hypertrophy model. We found that circCacna1c was upregulated in ISO-induced hypertrophic heart tissue and H9c2 cells. Western blot and quantitative real-time polymerase chain reaction showed that silencing circCacna1c inhibited hypertrophic gene expression in ISO-induced H9c2 cells. Mechanistically, circCacna1c competitively bound to miR-29b-2-5p in a dual-luciferase reporter assay, which was downregulated in ISO-induced hypertrophic heart tissue and H9c2 cells. MiR-29b-2-5p inhibited the nuclear factor of activated T cells, cytoplasmic, calcineurin-dependent 1 (NFATc1) to control hypertrophic gene expression. After silencing circCacna1c, the expression of miR-29b-2-5p increased, which reduced hypertrophic gene expression by inhibiting NFATc1 expression. Together, these experiments indicate that circCacna1c promotes ISO-induced pathological hypertrophy through the miR-29b-2-5p/NFATc1 axis.


Assuntos
Cardiomegalia , MicroRNAs , RNA Circular , Animais , Masculino , Camundongos , Cardiomegalia/induzido quimicamente , Cardiomegalia/genética , Cardiomegalia/metabolismo , Camundongos Endogâmicos C57BL , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Circular/genética , RNA Circular/metabolismo , Fatores de Transcrição
4.
Cell Commun Signal ; 20(1): 143, 2022 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-36104752

RESUMO

Spatiotemporal regulation of subcellular protein kinase A (PKA) activity for precise substrate phosphorylation is essential for cellular responses to hormonal stimulation. Ryanodine receptor 2 (RyR2) and (sarco)endoplasmic reticulum calcium ATPase 2a (SERCA2a) represent two critical targets of ß adrenoceptor (ßAR) signaling on the sarcoplasmic reticulum membrane for cardiac excitation and contraction coupling. Using novel biosensors, we show that cardiac ß1AR signals to both RyR2 and SERCA2a nanodomains in cardiomyocytes from mice, rats, and rabbits, whereas the ß2AR signaling is restricted from these nanodomains. Phosphodiesterase 4 (PDE4) and PDE3 control the baseline PKA activity and prevent ß2AR signaling from reaching the RyR2 and SERCA2a nanodomains. Moreover, blocking inhibitory G protein allows ß2AR signaling to the RyR2 but not the SERCA2a nanodomains. This study provides evidence for the differential roles of inhibitory G protein and PDEs in controlling the adrenergic subtype signaling at the RyR2 and SERCA2a nanodomains in cardiomyocytes. Video abstract.


Assuntos
Sinalização do Cálcio , Canal de Liberação de Cálcio do Receptor de Rianodina , Animais , Proteínas Quinases Dependentes de AMP Cíclico , Proteínas de Ligação ao GTP , Camundongos , Fosforilação , Coelhos , Ratos , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Retículo Sarcoplasmático/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático
5.
Basic Res Cardiol ; 117(1): 37, 2022 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-35842861

RESUMO

We have recently identified a pool of intracellular ß1 adrenergic receptors (ß1ARs) at the sarcoplasmic reticulum (SR) crucial for cardiac function. Here, we aim to characterize the integrative control of intracellular catecholamine for subcellular ß1AR signaling and cardiac function. Using anchored Förster resonance energy transfer (FRET) biosensors and transgenic mice, we determined the regulation of compartmentalized ß1AR-PKA signaling at the SR and plasma membrane (PM) microdomains by organic cation transporter 3 (OCT3) and monoamine oxidase A (MAO-A), two critical modulators of catecholamine uptake and homeostasis. Additionally, we examined local PKA substrate phosphorylation and excitation-contraction coupling in cardiomyocyte. Cardiac-specific deletion of MAO-A (MAO-A-CKO) elevates catecholamines and cAMP levels in the myocardium, baseline cardiac function, and adrenergic responses. Both MAO-A deletion and inhibitor (MAOi) selectively enhance the local ß1AR-PKA activity at the SR but not PM, and augment phosphorylation of phospholamban, Ca2+ cycling, and myocyte contractile response. Overexpression of MAO-A suppresses the SR-ß1AR-PKA activity and PKA phosphorylation. However, deletion or inhibition of OCT3 by corticosterone prevents the effects induced by MAOi and MAO-A deletion in cardiomyocytes. Deletion or inhibition of OCT3 also negates the effects of MAOi and MAO-A deficiency in cardiac function and adrenergic responses in vivo. Our data show that MAO-A and OCT3 act in concert to fine-tune the intracellular SR-ß1AR-PKA signaling and cardiac fight-or-flight response. We reveal a drug contraindication between anti-inflammatory corticosterone and anti-depressant MAOi in modulating adrenergic regulation in the heart, providing novel perspectives of these drugs with cardiac implications.


Assuntos
Corticosterona , Proteínas Quinases Dependentes de AMP Cíclico , Adrenérgicos/metabolismo , Adrenérgicos/farmacologia , Animais , Cálcio/metabolismo , Catecolaminas/metabolismo , Catecolaminas/farmacologia , Cátions/metabolismo , Cátions/farmacologia , Corticosterona/metabolismo , Corticosterona/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/farmacologia , Camundongos , Monoaminoxidase/metabolismo , Monoaminoxidase/farmacologia , Contração Miocárdica , Miócitos Cardíacos/metabolismo , Fosforilação , Receptores Adrenérgicos beta 1/genética , Receptores Adrenérgicos beta 1/metabolismo , Retículo Sarcoplasmático
6.
Cells ; 11(5)2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35269399

RESUMO

Heart failure is a major global health concern. Noncoding RNAs (ncRNAs) are involved in physiological processes and in the pathogenesis of various diseases, including heart failure. ncRNAs have emerged as critical components of transcriptional regulatory pathways that govern cardiac development, stress response, signaling, and remodeling in cardiac pathology. Recently, studies of ncRNAs in cardiovascular disease have achieved significant development. Here, we discuss the roles of ncRNAs, including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs) that modulate the cardiac hypertrophy and heart failure.


Assuntos
Insuficiência Cardíaca , RNA Longo não Codificante , Cardiomegalia/genética , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/metabolismo , Humanos , RNA Circular/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , RNA não Traduzido/genética , RNA não Traduzido/metabolismo
8.
Circ Res ; 128(2): 246-261, 2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33183171

RESUMO

RATIONALE: ß1ARs (ß1-adrenoceptors) exist at intracellular membranes and OCT3 (organic cation transporter 3) mediates norepinephrine entry into cardiomyocytes. However, the functional role of intracellular ß1AR in cardiac contractility remains to be elucidated. OBJECTIVE: Test localization and function of intracellular ß1AR on cardiac contractility. METHODS AND RESULTS: Membrane fractionation, super-resolution imaging, proximity ligation, coimmunoprecipitation, and single-molecule pull-down demonstrated a pool of ß1ARs in mouse hearts that were associated with sarco/endoplasmic reticulum Ca2+-ATPase at the sarcoplasmic reticulum (SR). Local PKA (protein kinase A) activation was measured using a PKA biosensor targeted at either the plasma membrane (PM) or SR. Compared with wild-type, myocytes lacking OCT3 (OCT3-KO [OCT3 knockout]) responded identically to the membrane-permeant ßAR agonist isoproterenol in PKA activation at both PM and SR. The same was true at the PM for membrane-impermeant norepinephrine, but the SR response to norepinephrine was suppressed in OCT3-KO myocytes. This differential effect was recapitulated in phosphorylation of the SR-pump regulator phospholamban. Similarly, OCT3-KO selectively suppressed calcium transients and contraction responses to norepinephrine but not isoproterenol. Furthermore, sotalol, a membrane-impermeant ßAR-blocker, suppressed isoproterenol-induced PKA activation at the PM but permitted PKA activation at the SR, phospholamban phosphorylation, and contractility. Moreover, pretreatment with sotalol in OCT3-KO myocytes prevented norepinephrine-induced PKA activation at both PM and the SR and contractility. CONCLUSIONS: Functional ß1ARs exists at the SR and is critical for PKA-mediated phosphorylation of phospholamban and cardiac contractility upon catecholamine stimulation. Activation of these intracellular ß1ARs requires catecholamine transport via OCT3.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Contração Miocárdica , Miócitos Cardíacos/metabolismo , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Receptores Adrenérgicos beta 1/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Agonistas Adrenérgicos beta/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Animais , Membrana Celular/metabolismo , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Feminino , Frequência Cardíaca , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Contração Miocárdica/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Proteínas de Transporte de Cátions Orgânicos/genética , Fosforilação , Coelhos , Ratos , Ratos Sprague-Dawley , Receptores Adrenérgicos beta 1/genética , Receptores Adrenérgicos beta 2/genética , Retículo Sarcoplasmático/metabolismo , Transdução de Sinais
9.
J Pharmacol Sci ; 144(1): 30-42, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32665128

RESUMO

To understand the mechanism underlying the regression of cardiac hypertrophy, we investigated the pathological changes after isoproterenol (ISO) withdrawal in ISO-induced cardiomyopathy models in rats and neonatal cardiomyocytes. Cardiac hypertrophy was induced in rats by two weeks of ISO administration; however, the hypertrophy did not regress after three weeks of natural maintenance after ISO administration was withdrawn (ISO-wdr group). The remaining hypertrophy in the ISO-wdr group was accompanied by a sustained increase in the level of phosphorylated Ca2+/calmodulin-dependent protein kinase II (p-CaMKII). Additionally, the increased expression levels of histone deacetylase 4 (HDAC4) and the CaV1.2 channel and amounts of CaMKII bound with HDAC4 and CaV1.2 were not recovered in the ISO-wdr group. The results in cardiomyocyte models were similar to those seen in rat models. Losartan, metoprolol or amlodipine neither ameliorated the increase in atrial natriuretic peptide nor inhibited the increase in p-CaMKII and bound CaMKII. In contrast, autocamtide-2-related inhibitor peptide, a CaMKII inhibitor, reduced these increases. This study investigated the phosphorylation status of CaMKII after hypertrophic stimulus was withdrawn for the first time and proposed that CaMKII as well as its complexes with CaV1.2 could be potential targets to achieve effective regression of cardiac hypertrophy.


Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Cardiomegalia/genética , Cardiomegalia/metabolismo , Isoproterenol/efeitos adversos , Animais , Canais de Cálcio Tipo L/metabolismo , Cardiomegalia/induzido quimicamente , Cardiomegalia/tratamento farmacológico , Modelos Animais de Doenças , Histona Desacetilases/metabolismo , Masculino , Terapia de Alvo Molecular , Miócitos Cardíacos/metabolismo , Fosforilação , Ligação Proteica , Ratos Sprague-Dawley
10.
Circ Res ; 127(6): 796-810, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32507058

RESUMO

RATIONALE: Cardiotoxic ß1 adrenergic receptor (ß1AR)-CaMKII (calmodulin-dependent kinase II) signaling is a major and critical feature associated with development of heart failure. SAP97 (synapse-associated protein 97) is a multifunctional scaffold protein that binds directly to the C-terminus of ß1AR and organizes a receptor signalosome. OBJECTIVE: We aim to elucidate the dynamics of ß1AR-SAP97 signalosome and its potential role in chronic cardiotoxic ß1AR-CaMKII signaling that contributes to development of heart failure. METHODS AND RESULTS: The integrity of cardiac ß1AR-SAP97 complex was examined in heart failure. Cardiac-specific deletion of SAP97 was developed to examine ß1AR signaling in aging mice, after chronic adrenergic stimulation, and in pressure overload hypertrophic heart failure. We show that the ß1AR-SAP97 signaling complex is reduced in heart failure. Cardiac-specific deletion of SAP97 yields an aging-dependent cardiomyopathy and exacerbates cardiac dysfunction induced by chronic adrenergic stimulation and pressure overload, which are associated with elevated CaMKII activity. Loss of SAP97 promotes PKA (protein kinase A)-dependent association of ß1AR with arrestin2 and CaMKII and turns on an Epac (exchange protein directly activated by cAMP)-dependent activation of CaMKII, which drives detrimental functional and structural remodeling in myocardium. Moreover, we have identified that GRK5 (G-protein receptor kinase-5) is necessary to promote agonist-induced dissociation of SAP97 from ß1AR. Cardiac deletion of GRK5 prevents adrenergic-induced dissociation of ß1AR-SAP97 complex and increases in CaMKII activity in hearts. CONCLUSIONS: These data reveal a critical role of SAP97 in maintaining the integrity of cardiac ß1AR signaling and a detrimental cardiac GRK5-CaMKII axis that can be potentially targeted in heart failure therapy. Graphical Abstract: A graphical abstract is available for this article.


Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Proteína 1 Homóloga a Discs-Large/metabolismo , Quinase 5 de Receptor Acoplado a Proteína G/metabolismo , Insuficiência Cardíaca/enzimologia , Miócitos Cardíacos/enzimologia , Receptores Adrenérgicos beta 1/metabolismo , Animais , Apoptose , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteína 1 Homóloga a Discs-Large/genética , Modelos Animais de Doenças , Acoplamento Excitação-Contração , Quinase 5 de Receptor Acoplado a Proteína G/genética , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Contração Miocárdica , Miócitos Cardíacos/patologia , beta-Arrestina 1/metabolismo
11.
Channels (Austin) ; 14(1): 151-162, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32290730

RESUMO

Residue Thr1604 in the CaV1.2 channel is a Ca2+/calmodulin dependent protein kinase II (CaMKII) phosphorylation site, and its phosphorylation status maintains the basic activity of the channel. However, the role of CaV1.2 phosphorylation at Thr1604 in myocardial hypertrophy is incompletely understood. Isoproterenol (ISO) was used to induce cardiomyocyte hypertrophy, and autocamtide-2-related inhibitory peptide (AIP) was added as a treatment. Rats in a myocardial hypertrophy development model were subcutaneously injected with ISO for two or three weeks. The heart and left ventricle weights, each of which were normalized to the body weight and cross-sectional area of the myocardial cells, were used to describe the degree of hypertrophy. Protein expression levels were detected by western blotting. CaMKII-induced CaV1.2 (Thr1604) phosphorylation (p-CaV1.2) was assayed by coimmunoprecipitation. The results showed that CaMKII, HDAC, MEF2 C, and atrial natriuretic peptide (ANP) expression was increased in the ISO group and downregulated by AIP treatment in vitro. There was no difference in the expression of these proteins between the ISO 2-week group and the ISO 3-week group in vivo. CaV1.2 channel expression did not change, but p-CaV1.2 expression was increased after ISO stimulation and decreased by AIP. In the rat model, p-CaV1.2 levels and CaMKII activity were much higher in the ISO 3-week group than in the ISO 2-week group. CaMKII-induced CaV1.2 channel phosphorylation at residue Thr1604 may be one of the key features of myocardial hypertrophy and disease development.Abbreviations: CaMKII: Ca2+/calmodulin dependent protein kinase II; p-CaMKII: autophosphorylated Ca2+/calmodulin dependent protein kinase II; CaM: calmodulin; AIP: autocamtide-2-related inhibitory peptide; ECC: excitation-contraction coupling; ISO: isoproterenol; BW: body weight; HW: heart weight; LVW: left ventricle weight; HDAC: histone deacetylase; p-HDAC: phosphorylated histone deacetylase; MEF2C: myocyte-specific enhancer factor 2C; ANP: atrial natriuretic peptide; PKC: protein kinase C.


Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/química , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Cardiomegalia/metabolismo , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Canais de Cálcio Tipo L , Cardiomegalia/induzido quimicamente , Células Cultivadas , Isoproterenol/toxicidade , Masculino , Miócitos Cardíacos/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
12.
J Cardiovasc Pharmacol ; 74(6): 516-527, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31815866

RESUMO

BACKGROUND: The quantitative association between serum/dietary magnesium and cardiovascular disease (CVD) remains unclear. We conducted a dose-response meta-analysis to evaluate the quantitative association between serum/dietary magnesium and CVD, including coronary heart disease (CHD). METHODS: PubMed, China National Knowledge Infrastructure, and Web of Science were searched for publications. STATA 12.0 was used to analyze data. We used the random-effects model to reduce heterogeneity. RESULTS: Eighteen prospective cohort studies with 544,581 participants and 22,658 CVD cases were included. The follow-up duration was 1-28 years. The pooled relative risk (RR) of CVD for the relatively normal versus lowest serum and dietary magnesium level was 0.64 {[95% confidence interval (CI): 0.51-0.80] and 0.90 [95% CI: 0.84-0.96]}. The pooled RR of CHD for the relatively normal versus lowest serum and dietary magnesium level was 0.70 (95% CI: 0.57-0.85) and 0.86 (95% CI: 0.77-0.94). We noted a significant association between increasing serum magnesium levels (per 0.1-mg/dL increase) and risk of CVD (RR: 0.93, 95% CI: 0.88-0.97) and CHD (RR: 0.90, 95% CI: 0.84-0.96) and between dietary magnesium levels (per 100-mg/d increase) and risk of CVD (RR: 0.90, 95% CI: 0.83-0.96) and CHD (RR: 0.92, 95% CI: 0.82-0.98). Serum/dietary Mg level comparisons presented a 7%-10% decrease in CVD/CHD risk. The dose-response meta-analyses showed linear relationships between serum magnesium and CVD (Pnonlinearity = 0.833) or CHD (Pnonlinearity = 0.193) and dietary magnesium and CVD (Pnonlinearity = 0.463) or CHD (Pnonlinearity = 0.440). CONCLUSIONS: Increasing dietary magnesium or serum magnesium level is linearly and inversely associated with the risk of total CVD and CHD events.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Doença das Coronárias/prevenção & controle , Dieta , Magnésio/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/mortalidade , Doença das Coronárias/sangue , Doença das Coronárias/diagnóstico , Doença das Coronárias/mortalidade , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Fatores de Proteção , Medição de Risco , Fatores de Risco , Fatores de Tempo
13.
Channels (Austin) ; 12(1): 311-325, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30134757

RESUMO

Although sodium channels have been a hot multidisciplinary focus for decades and most of nerve system drugs worked on alerting sodium channel function, the trends and future directions of sodium channel studies have not been comprehensive analyzed bibliometrically. Herein, we collected the scientific publications of sodium channels research and constructed a model to evaluate the current trend systematically. Publications were selected from the Web of Science Core Collection (WoSCC) database from 2013 to 2017. Microsoft Excel 2016, Prism 6, and CiteSpace V software were used to analyze publication outputs, journal sources, countries, territories, institutions, authors, and research areas. A total of 4,275 publications on sodium channel research were identified. PLoS ONE ranked top for publishing 170 papers. The United States of America had the largest number of publications (1,595), citation frequency (19,490), and H-index (53). S. G. Waxman (62 publications) and W. A. Catterall (585 citations) were the most productive authors and had the greatest co-citation counts. This is the first report that shows the trends and future development in sodium channel publications, and our study provides a clear profile for the contribution to this field by countries, authors, keywords, and institutions.


Assuntos
Bibliometria , Pesquisa/estatística & dados numéricos , Canais de Sódio/metabolismo , Bases de Dados de Proteínas , Humanos , Editoração
14.
Am J Chin Med ; 45(4): 863-877, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28595501

RESUMO

Astragaloside IV (AS-IV) is one of the active ingredients in Astragalus membrananceus (Huangqi), a traditional Chinese medicine. The present study investigated the effects of AS-IV on Ca[Formula: see text] handling in cardiac myocytes to elucidate its possible mechanism in the treatment of cardiac disease. The results showed that AS-IV at 1 and 10[Formula: see text][Formula: see text]M reduced KCl-induced [Ca[Formula: see text]]i increase ([Formula: see text] from 1.33[Formula: see text][Formula: see text][Formula: see text]0.04 (control, [Formula: see text] 28) to 1.22[Formula: see text][Formula: see text][Formula: see text]0.02 ([Formula: see text], [Formula: see text] 29) and 1.22[Formula: see text][Formula: see text][Formula: see text]0.02 ([Formula: see text] 0.01, [Formula: see text]), but it enhanced Ca[Formula: see text] release from SR ([Formula: see text] from 1.04[Formula: see text][Formula: see text][Formula: see text]0.01 (control, [Formula: see text]) to 1.44[Formula: see text][Formula: see text][Formula: see text]0.03 ([Formula: see text], [Formula: see text]) and 1.60[Formula: see text][Formula: see text][Formula: see text]0.04 ([Formula: see text] 0.01, [Formula: see text]0), in H9c2 cells. Similar results were obtained in native cardiomyocytes. AS-IV at 1 and 10[Formula: see text][Formula: see text]M inhibited L-type Ca[Formula: see text] current ([Formula: see text] from [Formula: see text]4.42[Formula: see text][Formula: see text][Formula: see text]0.58 pA/pF of control to [Formula: see text]2.25[Formula: see text][Formula: see text][Formula: see text]0.12 pA/pF ([Formula: see text] 0.01, [Formula: see text] 5) and [Formula: see text]1.78[Formula: see text][Formula: see text][Formula: see text]0.28 pA/pF ([Formula: see text] 0.01, [Formula: see text] 5) respectively, when the interference of [Ca[Formula: see text]]i was eliminated due to the depletion of SR Ca[Formula: see text] store by thapsigargin, an inhibitor of Ca[Formula: see text] ATPase. Moreover, when BAPTA, a rapid Ca[Formula: see text] chelator, was used, CDI (Ca[Formula: see text]-dependent inactivation) of [Formula: see text] was eliminated, and the inhibitory effects of AS-IV on ICaL were significantly reduced at the same time. These results suggest that AS-IV affects Ca[Formula: see text] homeostasis through two opposite pathways: inhibition of Ca[Formula: see text] influx through L-type Ca[Formula: see text] channel, and promotion of Ca[Formula: see text] release from SR.


Assuntos
Astragalus propinquus/química , Canais de Cálcio Tipo L/metabolismo , Cálcio/metabolismo , Membrana Celular/metabolismo , Miócitos Cardíacos/metabolismo , Saponinas/farmacologia , Retículo Sarcoplasmático/metabolismo , Triterpenos/farmacologia , Animais , Células Cultivadas , Depressão Química , Cobaias , Humanos , Miócitos Cardíacos/citologia , Técnicas de Patch-Clamp , Saponinas/isolamento & purificação , Estimulação Química , Triterpenos/isolamento & purificação
15.
J Pharmacol Sci ; 129(3): 143-9, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26422671

RESUMO

This study aimed to investigate the intracellular Mg(2+) regulation of the L-type Ca(2+) channels in guinea pig ventricular myocytes. By adopting the inside-out configuration of the patch clamp technique, single channel currents of the L-type Ca(2+) channels were recorded at different intracellular Mg(2+) concentrations ([Mg(2+)]i). At free [Mg(2+)]i of 0, 10(-9), 10(-7), 10(-5), 10(-3), and 10(-1) M, 1.4 µM CaM + 3 mM ATP induced channel activities of 44%, 117%, 202%, 181%, 147%, and 20% of the control activity in cell-attached mode, respectively, showing a bell-shaped concentration-response relationship. Moreover, the intracellular Mg(2+) modulated the Ca(2+) channel gating properties, accounting for alterations in channel activities. These results imply that Mg(2+) has a dual effect on the L-type Ca(2+) channels: facilitation and inhibition. Lower [Mg(2+)]i maintains and enhances the basal activity of Ca(2+) channels, whereas higher [Mg(2+)]i inhibits channel activity. Taken together, our data from the application of an [Mg(2+)]i series suggest that the dual effect of Mg(2+) upon the L-type Ca(2+) channels exhibits long open-time dependence.


Assuntos
Canais de Cálcio Tipo L/metabolismo , Magnésio/fisiologia , Células Musculares/metabolismo , Animais , Células Cultivadas , Cobaias , Ventrículos do Coração/citologia , Ativação do Canal Iônico/efeitos dos fármacos , Magnésio/farmacologia , Técnicas de Patch-Clamp/métodos
16.
Biochem Biophys Res Commun ; 460(3): 813-8, 2015 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-25824040

RESUMO

The activity of Cav1.2 Ca(2+) channels is maintained in the presence of calmodulin and ATP, even in cell-free patches, and thus a channel ATP-binding site has been suggested. In this study, we examined whether other nucleotides, such as GTP, UTP, CTP, ADP and AMP, could be substituted for ATP in guinea-pig ventricular myocytes. We found that all the nucleotides tested could re-prime the Ca(2+) channels in the presence of 1 µM calmodulin in the inside-out mode. The order of efficacy was ATP > GTP > UTP > ADP > CTP ≈ AMP. Thus, the presumed nucleotide-binding site in the channel seemed to favor a purine rather than pyrimidine base and a triphosphate rather than a di- or mono-phosphate group. Furthermore, a high concentration (10 mM) of GTP, UTP, CTP, ADP and AMP had inhibitory effects on the channel activity. These results provide information on the putative nucleotide-binding site(s) in Cav1.2 Ca(2+) channels.


Assuntos
Canais de Cálcio/metabolismo , Ventrículos do Coração/metabolismo , Músculo Liso Vascular/metabolismo , Nucleotídeos/fisiologia , Animais , Cobaias , Ventrículos do Coração/citologia , Músculo Liso Vascular/citologia
17.
Eur J Pharmacol ; 760: 27-35, 2015 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-25891370

RESUMO

Astragaloside IV (AS-IV) is one of the main active ingredients of Astragalus membranaceus. This study is aimed to investigate AS-IV׳s effects on Ca(2+) channel activity of single cardiomyocytes and single Ca(2+) channels. Whole-cell Ca(2+) currents in freshly dissociated cardiomyocytes were measured using the whole-cell patch-clamp technique. Single Ca(2+) channel currents were examined in cell-attached patches and inside-out patches. In the whole-cell recording, AS-IV reduced the amplitude of L-type Ca(2+) currents (ICaL) in a concentration-dependent manner. Although AS-IV did not alter the steady-state activation curves, the voltage dependence of the current inactivation curves was negatively shifted by AS-IV in a concentration dependent manner. Consistent with the results of the whole-cell recording, in the inside-out configuration the ensemble average of single Ba(2+) current via L-type Ca(2+) channel was dose-dependently reduced by AS-IV. The reduction of unitary Ba(2+) current at 0.1 or 1 µM AS-IV was accounted for a decrease in the channel activity (NPo). In addition to the decrease in NPo, there was a reduction of Po without a change in channel number or an apparent change in single channel current. Furthermore, we found that the open-closed kinetics of the channel were affected by AS-IV. AS-IV induced the shift of L-type Ca(2+) channels from either brief openings (mode 1) or long-lasting openings (mode 2) to no active opening (mode 0). Our results suggest that AS-IV blocks the currents through Ca(2+) channels in guinea-pig ventricular myocytes by affecting the open-closed kinetics of L-type Ca(2+) channels to inhibit the channel activities. This study could provide theoretical basis for the drug exploiting of the monomer of Astragalus membranaceus.


Assuntos
Canais de Cálcio Tipo L/fisiologia , Medicamentos de Ervas Chinesas/farmacologia , Ativação do Canal Iônico/fisiologia , Miócitos Cardíacos/fisiologia , Saponinas/farmacologia , Triterpenos/farmacologia , Animais , Relação Dose-Resposta a Droga , Fenômenos Eletrofisiológicos/efeitos dos fármacos , Fenômenos Eletrofisiológicos/fisiologia , Cobaias , Ventrículos do Coração/citologia , Ventrículos do Coração/efeitos dos fármacos , Ativação do Canal Iônico/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos
18.
Am J Physiol Cell Physiol ; 308(8): C594-605, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25652447

RESUMO

Culture of hippocampal neurons in low-Mg(2+) medium (low-Mg(2+) neurons) results in induction of continuous seizure activity. However, the underlying mechanism of the contribution of low Mg(2+) to hyperexcitability of neurons has not been clarified. Our data, obtained using the patch-clamp technique, show that voltage-gated Na(+) channel (VGSC) activity, which is associated with a persistent, noninactivating Na(+) current (INa,P), was modulated by calmodulin (CaM) in a concentration-dependent manner in normal and low-Mg(2+) neurons, but the channel activity was more sensitive to Ca(2+)/CaM regulation in low-Mg(2+) than normal neurons. The increased sensitivity of VGSCs in low-Mg(2+) neurons was partially retained when CaM12 and CaM34, CaM mutants with disabled binding sites in the N or C lobe, were used but was diminished when CaM1234, a CaM mutant in which all four Ca(2+) sites are disabled, was used, indicating that functional Ca(2+)-binding sites from either lobe of CaM are required for modulation of VGSCs in low-Mg(2+) neurons. Furthermore, the number of neurons exhibiting colocalization of CaM with the VGSC subtypes NaV1.1, NaV1.2, and NaV1.3 was significantly higher in low- Mg(2+) than normal neurons, as shown by immunofluorescence. Our main finding is that low-Mg(2+) treatment increases sensitivity of VGSCs to Ca(2+)/CaM-mediated regulation. Our data reveal that CaM, as a core regulating factor, connects the functional roles of the three main intracellular ions, Na(+), Ca(2+), and Mg(2+), by modulating VGSCs and provides a possible explanation for the seizure discharge observed in low-Mg(2+) neurons.


Assuntos
Cálcio/farmacologia , Calmodulina/farmacologia , Hipocampo/citologia , Magnésio/farmacologia , Convulsões/metabolismo , Canais de Sódio Disparados por Voltagem/metabolismo , Trifosfato de Adenosina/metabolismo , Ondas Encefálicas , Membrana Celular/metabolismo , Células Cultivadas , Humanos , Técnicas de Patch-Clamp , Tetrodotoxina/farmacologia , Bloqueadores do Canal de Sódio Disparado por Voltagem/farmacologia
19.
Sheng Li Xue Bao ; 66(6): 718-22, 2014 Dec 25.
Artigo em Chinês | MEDLINE | ID: mdl-25516521

RESUMO

This study is aimed to investigate the effects of high intracellular Mg²âº on L-type calcium channel in guinea-pig ventricular myocytes. The cardiomyocytes were acutely isolated with enzyme digestion method. By adopting inside-out configuration of patch clamp technique, single channel currents of the L-type calcium channel were recorded under different intracellular Mg²âº concentrations ([Mg²âº]i). In control group, which was treated with 0.9 mmol/L Mg²âº, the relative activity of calcium channel was (176.5 ± 34.1)% (n = 7). When [Mg²âº]i was increased from 0.9 to 8.1 mmol/L (high Mg²âº group), the relative activities of calcium channel decreased to (64.8 ± 18.1)% (n = 6, P < 0.05). Moreover, under 8.1 mmol/L Mg²âº, the mean open time of calcium channel was shortened to about 25% of that under control condition (P < 0.05), but the mean close time of calcium channel was not altered. These results suggest that high intracellular Mg²âº may inhibit the activities of L-type calcium channel, which is mainly due to the shortening of the mean open time of single L-type calcium channel.


Assuntos
Canais de Cálcio Tipo L/fisiologia , Magnésio/fisiologia , Miócitos Cardíacos/fisiologia , Animais , Cobaias , Técnicas de Patch-Clamp
20.
PLoS One ; 9(10): e109725, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25329998

RESUMO

Links between epithelial ion channels and chronic obstructive pulmonary diseases (COPD) are emerging through animal model and in vitro studies. However, clinical correlations between fluid-regulating channel proteins and lung function in COPD remain to be elucidated. To quantitatively measure epithelial sodium channels (ENaC), cystic fibrosis transmembrane conductance regulator (CFTR), and aquaporin 5 (AQP5) proteins in human COPD lungs and to analyze the correlation with declining lung function, quantitative western blots were used. Spearman tests were performed to identify correlations between channel proteins and lung function. The expression of α and ß ENaC subunits was augmented and inversely associated with lung function. In contrast, both total and alveolar type I (ATI) and II (ATII)-specific CFTR proteins were reduced. The expression level of CFTR proteins was associated with FEV1 positively. Abundance of AQP5 proteins and extracellular superoxide dismutase (SOD3) was decreased and correlated with spirometry test results and gas exchange positively. Furthermore, these channel proteins were significantly associated with severity of disease. Our study demonstrates that expression of ENaC, AQP5, and CFTR proteins in human COPD lungs is quantitatively associated with lung function and severity of COPD. These apically located fluid-regulating channels may thereby serve as biomarkers and potent druggable targets of COPD.


Assuntos
Aquaporina 5/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Canais Epiteliais de Sódio/metabolismo , Doença Pulmonar Obstrutiva Crônica/metabolismo , Troca Gasosa Pulmonar , Idoso , Aquaporina 5/genética , Estudos de Casos e Controles , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Canais Epiteliais de Sódio/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/fisiopatologia
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