RESUMO
A ketogenic diet (KD) might alleviate patients with diabetic cardiomyopathy. However, the underlying mechanism remains unclear. Myocardial function and arrhythmogenesis are closely linked to calcium (Ca2+) homeostasis. We investigated the effects of a KD on Ca2+ homeostasis and electrophysiology in diabetic cardiomyopathy. Male Wistar rats were created to have diabetes mellitus (DM) using streptozotocin (65 mg/kg, intraperitoneally), and subsequently treated for 6 weeks with either a normal diet (ND) or a KD. Our electrophysiological and Western blot analyses assessed myocardial Ca2+ homeostasis in ventricular preparations in vivo. Unlike those on the KD, DM rats treated with an ND exhibited a prolonged QTc interval and action potential duration. Compared to the control and DM rats on the KD, DM rats treated with an ND also showed lower intracellular Ca2+ transients, sarcoplasmic reticular Ca2+ content, sodium (Na+)-Ca2+ exchanger currents (reverse mode), L-type Ca2+ contents, sarcoplasmic reticulum ATPase contents, Cav1.2 contents. Furthermore, these rats exhibited elevated ratios of phosphorylated to total proteins across multiple Ca2+ handling proteins, including ryanodine receptor 2 (RyR2) at serine 2808, phospholamban (PLB)-Ser16, and calmodulin-dependent protein kinase II (CaMKII). Additionally, DM rats treated with an ND demonstrated a higher frequency and incidence of Ca2+ leak, cytosolic reactive oxygen species, Na+/hydrogen-exchanger currents, and late Na+ currents than the control and DM rats on the KD. KD treatment may attenuate the effects of DM-dysregulated Na+ and Ca2+ homeostasis, contributing to its cardioprotection in DM.
Assuntos
Diabetes Mellitus , Cardiomiopatias Diabéticas , Dieta Cetogênica , Humanos , Ratos , Masculino , Animais , Cálcio/metabolismo , Miócitos Cardíacos/metabolismo , Cardiomiopatias Diabéticas/metabolismo , Remodelação Ventricular , Ratos Wistar , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Sódio/metabolismo , Homeostase , Retículo Sarcoplasmático/metabolismo , Diabetes Mellitus/metabolismoRESUMO
Diabetes mellitus (DM) is an independent risk factor for atrial fibrillation (AF), which is the most common sustained arrhythmia and is associated with substantial morbidity and mortality. Advanced glycation end product and its receptor activation, cardiac energy dysmetabolism, structural and electrical remodeling, and autonomic dysfunction are implicated in AF pathophysiology in diabetic hearts. Antidiabetic drugs have been demonstrated to possess therapeutic potential for AF. However, clinical investigations of AF in patients with DM have been scant and inconclusive. This article provides a comprehensive review of research findings on the association between DM and AF and critically analyzes the effect of different pharmacological classes of antidiabetic drugs on AF.
Assuntos
Fibrilação Atrial/etiologia , Hipoglicemiantes/efeitos adversos , Fibrilação Atrial/metabolismo , Diabetes Mellitus/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/efeitos adversos , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Receptor do Peptídeo Semelhante ao Glucagon 1/antagonistas & inibidores , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Humanos , Hipoglicemiantes/uso terapêutico , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Fatores de Risco , Inibidores do Transportador 2 de Sódio-Glicose/efeitos adversos , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêuticoRESUMO
BACKGROUND: The use of mobile health technologies has been necessary to deliver patient education to patients with diabetes during the COVID-19 pandemic. OBJECTIVE: This open-label randomized controlled trial evaluated the effects of a diabetes educational platform-Taipei Medical University-LINE Oriented Video Education-delivered through a social media app. METHODS: Patients with type 2 diabetes were recruited from a clinic through physician referral. The social media-based program included 51 videos: 10 about understanding diabetes, 10 about daily care, 6 about nutrition care, 21 about diabetes drugs, and 4 containing quizzes. The intervention group received two or three videos every week and care messages every 2 weeks through the social media platform for 3 months, in addition to usual care. The control group only received usual care. Outcomes were measured at clinical visits through self-reported face-to-face questionnaires at baseline and at 3 months after the intervention, including the Simplified Diabetes Knowledge Scale (true/false version), the Diabetes Care Profile-Attitudes Toward Diabetes Scales, the Summary of Diabetes Self-Care Activities, and glycated hemoglobin (HbA1c) levels. Health literacy was measured at baseline using the Newest Vital Sign tool. Differences in HbA1c levels and questionnaire scores before and after the intervention were compared between groups. The associations of knowledge, attitudes, and self-care activities with health literacy were assessed. RESULTS: Patients with type 2 diabetes completed the 3-month study, with 91 out of 181 (50.3%) patients in the intervention group and 90 (49.7%) in the control group. The change in HbA1c did not significantly differ between groups (intervention group: mean 6.9%, SD 0.8% to mean 7.0%, SD 0.9%, P=.34; control group: mean 6.7%, SD 0.6% to mean 6.7%, SD 0.7%, P=.91). Both groups showed increased mean knowledge scores at 12 weeks, increasing from 68.3% (SD 16.4%) to 76.7% (SD 11.7%; P<.001) in the intervention group and from 64.8% (SD 18.2%) to 73.2% (SD 12.6%; P<.001) in the control group. Positive improvements in attitudes and self-care activities were only observed in the intervention group (attitudes: mean difference 0.2, SD 0.5, P=.001; self-care activities: mean difference 0.3, SD 1.2, P=.03). A 100% utility rate was achieved for 8 out of 21 (38%) medication-related videos. Low health literacy was a significant risk factor for baseline knowledge scores in the intervention group, with an odds ratio of 2.80 (95% CI 1.28-6.12; P=.01); this became insignificant after 3 months. CONCLUSIONS: The social media-based program was effective at enhancing the knowledge, attitudes, and self-care activities of patients with diabetes. This intervention was also helpful for patients with low health literacy in diabetes knowledge. The program represents a potentially useful tool for delivering diabetes education to patients through social media, especially during the COVID-19 pandemic. TRIAL REGISTRATION: ClinicalTrials.gov NCT04876274; https://clinicaltrials.gov/ct2/show/results/NCT04876274.
Assuntos
COVID-19 , Diabetes Mellitus Tipo 2 , Autogestão , Mídias Sociais , Diabetes Mellitus Tipo 2/terapia , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Pandemias , Educação de Pacientes como AssuntoRESUMO
BACKGROUND: Type 2 diabetes mellitus (T2DM), common in older people, is an important reason for muscle loss in Japanese and Taiwanese populations. However, little is known about the association between lifestyle behaviours and muscle quality. We aimed to compare the lifestyle behaviours of Japanese and Taiwanese older adults with T2DM and to the identify lifestyle factors associated with muscle quality. METHODS: This cross-sectional study was conducted among community-dwelling individuals with T2DM aged ≥65 years in Taiwan and Japan. Totally, 114 Japanese and 226 Taiwanese participants were enrolled in the study. Outcomes were measured by blood biochemical examinations, body composition analyses and structured self-reported questionnaires to assess lifestyle behaviours and muscle quality. Linear regression models were used to examine the relationship between lifestyle factors and muscle quality using SPSS version 27.0 with a statistical significance level of P < 0.05. RESULTS: Japanese subjects were more likely to be smokers and alcohol consumers, and they were less likely to have well-balanced diets and engage in more physical activity as compared to Taiwanese subjects. The muscle quality in the Japanese subjects was significantly poorer than that in the Taiwanese subjects. Physical activity, dietary habits and smoking were associated with muscle quality, after adjusting for age, gender and body mass index. CONCLUSIONS: Physical activity of insufficient intensity, unhealthy dietary habits and smoking could be risk factors for poor muscle quality. These findings can contribute to the development of effective strategies to improve muscle quality in community-dwelling older Asian people with T2DM.
Assuntos
Diabetes Mellitus Tipo 2 , Vida Independente , Idoso , Estudos Transversais , Diabetes Mellitus Tipo 2/epidemiologia , Humanos , Japão/epidemiologia , Estilo de Vida , Músculos , Taiwan/epidemiologiaRESUMO
Fibroblast growth factor (FGF)-23 induces hypertrophy and calcium (Ca2+) dysregulation in cardiomyocytes, leading to cardiac arrhythmia and heart failure. However, knowledge regarding the effects of FGF-23 on cardiac fibrogenesis remains limited. This study investigated whether FGF-23 modulates cardiac fibroblast activity and explored its underlying mechanisms. We performed MTS analysis, 5-ethynyl-2'-deoxyuridine assay, and wound-healing assay in cultured human atrial fibroblasts without and with FGF-23 (1, 5 and 25 ng/mL for 48 h) to analyze cell proliferation and migration. We found that FGF-23 (25 ng/mL, but not 1 or 5 ng/mL) increased proliferative and migratory abilities of human atrial fibroblasts. Compared to control cells, FGF-23 (25 ng/mL)-treated fibroblasts had a significantly higher Ca2+ entry and intracellular inositol 1,4,5-trisphosphate (IP3) level (assessed by fura-2 ratiometric Ca2+ imaging and enzyme-linked immunosorbent assay). Western blot analysis showed that FGF-23 (25 ng/mL)-treated cardiac fibroblasts had higher expression levels of calcium release-activated calcium channel protein 1 (Orai1) and transient receptor potential canonical (TRPC) 1 channel, but similar expression levels of α-smooth muscle actin, collagen type IA1, collagen type â ¢, stromal interaction molecule 1, TRPC 3, TRPC6 and phosphorylated-calcium/calmodulin-dependent protein kinase II when compared with control fibroblasts. In the presence of ethylene glycol tetra-acetic acid (a free Ca2+ chelator, 1 mM) or U73122 (an inhibitor of phospholipase C, 1 µM), control and FGF-23-treated fibroblasts exhibited similar proliferative and migratory abilities. Moreover, polymerase chain reaction analysis revealed that atrial fibroblasts abundantly expressed FGF receptor 1 but lacked expressions of FGF receptors 2-4. FGF-23 significantly increased the phosphorylation of FGF receptor 1. Treatment with PD166866 (an antagonist of FGF receptor 1, 1 µM) attenuated the effects of FGF-23 on cardiac fibroblast activity. In conclusion, FGF-23 may activate FGF receptor 1 and subsequently phospholipase C/IP3 signaling pathway, leading to an upregulation of Orai1 and/or TRPC1-mediated Ca2+ entry and thus enhancing human atrial fibroblast activity.
Assuntos
Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Fator de Crescimento de Fibroblastos 23/metabolismo , Fibroblastos/metabolismo , Fosfolipases Tipo C/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Células Cultivadas , Colágeno Tipo III/metabolismo , Fibrose/metabolismo , Átrios do Coração/metabolismo , Humanos , Miócitos Cardíacos/metabolismo , Fosforilação/fisiologiaRESUMO
Glucagon-like peptide 1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2is) are antihyperglycemic agents with cardioprotective properties against diabetic cardiomyopathy (DCM). However, the distinctive mechanisms underlying GLP-1RAs and SGLT2is in DCM are not fully elucidated. The purpose of this study was to investigate the impacts of GLP1RAs and/or SGLT2is on myocardial energy metabolism, cardiac function, and apoptosis signaling in DCM. Biochemistry and echocardiograms were studied before and after treatment with empagliflozin (10 mg/kg/day, oral gavage), and/or liraglutide (200 µg/kg every 12 h, subcutaneously) for 4 weeks in male Wistar rats with streptozotocin (65 mg/kg intraperitoneally)-induced diabetes. Cardiac fibrosis, apoptosis, and protein expression of metabolic and inflammatory signaling molecules were evaluated by histopathology and Western blotting in ventricular cardiomyocytes of different groups. Empagliflozin and liraglutide normalized myocardial dysfunction in diabetic rats. Upregulation of phosphorylated-acetyl coenzyme A carboxylase, carnitine palmitoyltransferase 1ß, cluster of differentiation 36, and peroxisome proliferator-activated receptor-gamma coactivator, and downregulation of glucose transporter 4, the ratio of phosphorylated adenosine monophosphate-activated protein kinase α2 to adenosine monophosphate-activated protein kinase α2, and the ratio of phosphorylated protein kinase B to protein kinase B in diabetic cardiomyocytes were restored by treatment with empagliflozin or liraglutide. Nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3, interleukin-1ß, tumor necrosis factor-α, and cleaved caspase-1 were significantly downregulated in empagliflozin-treated and liraglutide-treated diabetic rats. Both empagliflozin-treated and liraglutide-treated diabetic rats exhibited attenuated myocardial fibrosis and apoptosis. Empagliflozin modulated fatty acid and glucose metabolism, while liraglutide regulated inflammation and apoptosis in DCM. The better effects of combined treatment with GLP-1RAs and SGLT2is may lead to a potential strategy targeting DCM.
Assuntos
Compostos Benzidrílicos/farmacologia , Cardiomiopatias Diabéticas/metabolismo , Metabolismo Energético/efeitos dos fármacos , Glucosídeos/farmacologia , Liraglutida/farmacologia , Miocárdio/metabolismo , Animais , Apoptose/efeitos dos fármacos , Biomarcadores , Citocinas/biossíntese , Cardiomiopatias Diabéticas/diagnóstico , Cardiomiopatias Diabéticas/tratamento farmacológico , Cardiomiopatias Diabéticas/etiologia , Modelos Animais de Doenças , Ecocardiografia , Ácidos Graxos/metabolismo , Fibrose , Glucose/metabolismo , Testes de Função Cardíaca , Hipoglicemiantes/farmacologia , Imuno-Histoquímica , Mediadores da Inflamação/metabolismo , Ratos , Inibidores do Transportador 2 de Sódio-Glicose/farmacologiaRESUMO
Vascular endothelial growth factor (VEGF), a pivotal activator of angiogenesis and calcium (Ca2+) signaling in endothelial cells, was shown to increase collagen production in atrial fibroblasts. In this study, we evaluated whether VEGF may regulate Ca2+ homeostasis in atrial fibroblasts and contribute to its profibrogenesis. Migration, and proliferation analyses, patch-clamp assay, Ca2+ fluorescence imaging, and western blotting were performed using VEGF-treated (300 pg/mL or 1000 pg/mL) human atrial fibroblasts with or without coadministration of Ethylene glycol tetra-acetic acid (EGTA, 1 mmol/L), or KN93 (a Ca2+/calmodulin-dependent protein kinase II [CaMKII] inhibitor, 10 µmol/L). VEGF (1000 pg/mL) increased migration, myofibroblast differentiation, pro-collagen type I, pro-collagen type III production, and phosphorylated VEGF receptor 1 expression of fibroblasts. VEGF (1000 pg/mL) increased the nonselective cation current (INSC) of transient receptor potential (TRP) channels and potassium current of intermediate-conductance Ca2+-activated K+ (KCa3.1) channels thereby upregulating Ca2+ entry. VEGF upregulated phosphorylated ERK expression. An ERK inhibitor (PD98059, 50 µmol/L) attenuated VEGF-activated INSC of TRP channels. The presence of EGTA attenuated the profibrotic effects of VEGF on pro-collagen type I, pro-collagen type III production, myofibroblast differentiation, and migratory capabilities of fibroblasts. VEGF upregulated the expression of phosphorylated CaMKII in fibroblasts, which was attenuated by EGTA. In addition, KN93 reduced VEGF-increased pro-collagen type I, pro-collagen type III production, myofibroblast differentiation, and the migratory capabilities of fibroblasts. In conclusion, we found that VEGF increases atrial fibroblast activity through CaMKII signaling by enhancing Ca2+ entry. Our findings provide benchside evidence leading to a potential novel strategy targeting atrial myopathy and arrhythmofibrosis.
Assuntos
Cálcio/metabolismo , Fibroblastos/metabolismo , Fibrose/metabolismo , Átrios do Coração/citologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Sinalização do Cálcio/fisiologia , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Células Cultivadas , Homeostase/fisiologia , HumanosRESUMO
Cardiovascular diseases (CVDs) are among the leading threats to human health. The advanced glycation end product (AGE) and receptor for AGE (RAGE) signaling pathway regulates the pathogenesis of CVDs, through its effects on arterial stiffness, atherosclerosis, mitochondrial dysfunction, oxidative stress, calcium homeostasis, and cytoskeletal function. Targeting the AGE/RAGE pathway is a potential therapeutic strategy for ameliorating CVDs. Vitamin D has several beneficial effects on the cardiovascular system. Experimental findings have shown that vitamin D regulates AGE/RAGE signaling and its downstream effects. This article provides a comprehensive review of the mechanistic insights into AGE/RAGE involvement in CVDs and the modulation of the AGE/RAGE signaling pathways by vitamin D.
Assuntos
Cardiomiopatias Diabéticas/prevenção & controle , Produtos Finais de Glicação Avançada/genética , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocardite/prevenção & controle , Receptor para Produtos Finais de Glicação Avançada/genética , Vitamina D/uso terapêutico , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/ultraestrutura , Animais , Cálcio/metabolismo , Cardiotônicos/uso terapêutico , Cardiomiopatias Diabéticas/sangue , Cardiomiopatias Diabéticas/genética , Cardiomiopatias Diabéticas/patologia , Regulação da Expressão Gênica , Produtos Finais de Glicação Avançada/sangue , Guanidinas/uso terapêutico , Humanos , Traumatismo por Reperfusão Miocárdica/sangue , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/patologia , Miocardite/sangue , Miocardite/genética , Miocardite/patologia , Estresse Oxidativo/efeitos dos fármacos , Receptor para Produtos Finais de Glicação Avançada/sangue , Transdução de Sinais , Tiazóis/uso terapêutico , Rigidez Vascular/efeitos dos fármacos , Vitamina D/sangueRESUMO
Tumour necrosis factor (TNF)-α induces cardiac metabolic disorder and mitochondrial dysfunction. Hydrogen sulphide (H2 S) contains anti-inflammatory and biological effects in cardiomyocytes. This study investigated whether H2 S modulates TNF-α-dysregulated mitochondrial function and metabolism in cardiomyocytes. HL-1 cells were incubated with TNF-α (25 ng/mL) with or without sodium hydrosulphide (NaHS, 0.1 mmol/L) for 24 hours. Cardiac peroxisome proliferator-activated receptor (PPAR) isoforms, pro-inflammatory cytokines, receptor for advanced glycation end products (RAGE) and fatty acid metabolism were evaluated through Western blotting. The mitochondrial oxygen consumption rate and adenosine triphosphate (ATP) production were investigated using Seahorse XF24 extracellular flux analyzer and bioluminescence assay. Fluorescence intensity using 2', 7'-dichlorodihydrofluorescein diacetate was used to evaluate mitochondrial oxidative stress. NaHS attenuated the impaired basal and maximal respiration, ATP production and ATP synthesis and enhanced mitochondrial oxidative stress in TNF-α-treated HL-1 cells. TNF-α-treated HL-1 cells exhibited lower expression of PPAR-α, PPAR-δ, phosphorylated 5' adenosine monophosphate-activated protein kinase-α2, phosphorylated acetyl CoA carboxylase, carnitine palmitoyltransferase-1, PPAR-γ coactivator 1-α and diacylglycerol acyltransferase 1 protein, but higher expression of PPAR-γ, interleukin-6 and RAGE protein than control or combined NaHS and TNF-α-treated HL-1 cells. NaHS modulates the effects of TNF-α on mitochondria and the cardiometabolic system, suggesting its therapeutic potential for inflammation-induced cardiac dysfunction.
Assuntos
Mitocôndrias/metabolismo , Mitocôndrias/patologia , Sulfetos/farmacologia , Fator de Necrose Tumoral alfa/toxicidade , Trifosfato de Adenosina/biossíntese , Animais , Linhagem Celular , Citocinas/metabolismo , Ácidos Graxos/metabolismo , Glucose/metabolismo , Mediadores da Inflamação/metabolismo , Insulina/metabolismo , Camundongos , Mitocôndrias/efeitos dos fármacos , Miocárdio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Diabetes mellitus (DM) has significant effects on cardiac calcium (Ca2+) and sodium (Naâº) regulation. Clinical studies have shown that empagliflozin (Jardiance™) has cardiovascular benefits, however the mechanisms have not been fully elucidated. This study aimed to investigate whether empagliflozin modulates cardiac electrical activity as well as Ca2+/Na⺠homeostasis in DM cardiomyopathy. Electrocardiography, echocardiography, whole-cell patch-clamp, confocal microscopic examinations, and Western blot, were performed in the ventricular myocytes of control and streptozotocin-induced DM rats, with or without empagliflozin (10 mg/kg for 4 weeks). The results showed that the control and empagliflozin-treated DM rats had smaller left ventricular end-diastolic diameters and shorter QT intervals than the DM rats. In addition, the prolonged action potential duration in the DM rats was attenuated in the empagliflozin-treated DM rats. Moreover, the DM rats had smaller sarcoplasmic reticular Ca2+ contents, intracellular Ca2+ transients, L-type Ca2+, reverse mode Naâº-Ca2+exchanger currents, lower protein expressions of sarcoplasmic reticulum ATPase, ryanodine receptor 2 (RyR2), but higher protein expressions of phosphorylated RyR2 at serine 2808 than the control and empagliflozin-treated DM rats. The incidence and frequency of Ca2+ sparks, cytosolic and mitochondrial reactive oxygen species, and late Na⺠current and Naâº/hydrogen-exchanger currents were greater in the DM rats than in the control and empagliflozin-treated DM rats. Empagliflozin significantly changed Ca2+ regulation, late Na⺠and Naâº/hydrogen-exchanger currents and electrophysiological characteristics in DM cardiomyopathy, which may contribute to its cardioprotective benefits in DM patients.
Assuntos
Compostos Benzidrílicos/uso terapêutico , Cálcio/metabolismo , Glucosídeos/uso terapêutico , Miocárdio/metabolismo , Animais , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Eletrofisiologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Ratos , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Sódio/metabolismo , Trocador de Sódio e Cálcio/metabolismoRESUMO
BACKGROUND: Fibroblast growth factor (FGF)-2 plays a crucial role in the pathophysiology of cardiovascular diseases (CVDs). FGF-2 was reported to induce cardiac hypertrophy through activation of FGF receptor 1 (FGFR1). Multiple laboratory findings indicate that calcitriol may be a potential treatment for CVDs. In this study, we attempted to investigate whether calcitriol regulates FGFR1 expression to modulate the effects of FGF-2 signaling in cardiac myocytes and explored the potential regulatory mechanism. METHODS: Western blot, polymerase chain reaction, small interfering RNA, fluorometric activity assay, and chromatin immunoprecipitation (ChIP) analyses were used to evaluate FGFR1, FGFR2, FGFR3, FGFR4, phosphorylated extracellular signal-regulated kinase (p-ERK), ß-myosin heavy chain (ß-MHC), phosphorylated phospholipase Cγ (p-PLCγ), nuclear factor of activated T cells (NFAT), and histone deacetylase (HDAC) expressions and enzyme activities in HL-1 atrial myocytes without and with calcitriol (1 and 10 nM) treatment, in the absence and presence of FGF-2 (25 ng/mL) or suberanilohydroxamic acid (SAHA, a pan-HDAC inhibitor, 1 µM). RESULTS: We found that calcitriol-treated HL-1 cells had significantly reduced FGFR1 expression compared to control cells. In contrast, expressions of FGFR2, FGFR3, and FGFR4 were similar between calcitriol-treated and control HL-1 cells. FGF-2-treated HL-1 cells had similar PLCγ phosphorylation and nuclear/cytoplasmic NFAT expressions compared to control cells. FGF-2 induced lower expressions of p-ERK and ß-MHC in calcitriol-treated HL-1 cells than in control cells. FGFR1-knockdown blocked FGF-2 signaling and reversed the protective effects of calcitriol. Compared to control cells, calcitriol-treated HL-1 cells had higher nuclear HDAC activity. The ChIP analysis demonstrated a significant decrease in acetyl-histone H4, which is associated with an increase in HDAC3 in the FGFR1 promoter. Calcitriol-mediated FGFR1 downregulation was attenuated in the presence of SAHA. CONCLUSIONS: Calcitriol diminished FGFR1 expression through HDAC activation, which ameliorated the harmful effects of FGF-2 on cardiac myocytes.
Assuntos
Calcitriol/farmacologia , Histona Desacetilase 1/genética , Miócitos Cardíacos/metabolismo , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Transdução de Sinais , Vitaminas/farmacologia , Animais , Regulação para Baixo , Histona Desacetilase 1/metabolismo , Camundongos , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismoRESUMO
Aging plays a critical role in the genesis of atrial fibrillation (AF) and also increases the risks of cardiac dysfunction and stroke in AF patients. AF is caused by increased AF triggering from abnormalities of the thoracic vein and/or modulated substrate (atrial) with enhancement of AF maintenance. Clinical and laboratory evidence indicates that aging is significant in the creation of atrial electrical and structural remodeling that leads to increased susceptibility to AF occurrence. Aging is commonly associated with cardiovascular comorbidities, oxidative stress, calcium dysregulation, atrial myopathy with apoptosis, and fibrosis, which all contribute to the genesis of AF. This review updates the current understanding of the effects of aging on the pathophysiology of AF.
Assuntos
Envelhecimento , Fibrilação Atrial , Remodelamento Atrial , Adulto , Idoso , Envelhecimento/metabolismo , Envelhecimento/patologia , Animais , Fibrilação Atrial/metabolismo , Fibrilação Atrial/patologia , Fibrilação Atrial/fisiopatologia , Feminino , Átrios do Coração/metabolismo , Átrios do Coração/patologia , Átrios do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , CoelhosRESUMO
BACKGROUND: Receptor for advanced glycation end products (RAGE) signalling plays a critical role in the pathogenesis of cardiovascular disease. Calcitriol modulates cardiac RAGE expression. This study explored the mechanisms underlying the effect of calcitriol on RAGE and soluble RAGE (sRAGE) expression in cardiomyocytes. MATERIALS AND METHODS: Western blot, ELISA, fluorometric assay and PCR analyses were used to evaluate the RAGE, sRAGE, endogenous secretory RAGE (esRAGE), Jun N-terminal kinase (JNK), and a disintegrin and metalloprotease 10 (ADAM10) expression and enzyme activity in HL-1 atrial myocytes without and with calcitriol (10 and 100 nM), nuclear factor-κB (NF-κB) inhibitor (50 µg/mL), or ADAM10 inhibitor (5 µM) incubation for 48 h. RESULTS: Calcitriol (10 nM) significantly reduced RAGE protein expression and increased sRAGE concentrations in HL-1 cardiomyocytes compared with control cells. These changes were associated with increased protein expression and enzyme activity of ADAM10 and higher mRNA expression of esRAGE. In the presence of ADAM10 inhibitor, however, the suppressive effect of calcitriol on RAGE was diminished. Methylglyoxal (500 µM for 10 min)-mediated JNK phosphorylation was attenuated in the presence of calcitriol (10 nM). Moreover, control and NF-κB inhibitor-treated HL-1 cells had similar RAGE and sRAGE expression, suggesting that calcitriol-mediated RAGE modulation was independent of NF-κB signalling. CONCLUSIONS: We showed that RAGE downregulation and increased sRAGE production by calcitriol were mediated through ADAM10 activation in cardiomyocytes. The results suggest that calcitriol has therapeutic potential in treating RAGE-mediated cardiovascular complications.
Assuntos
Proteína ADAM10/efeitos dos fármacos , Secretases da Proteína Precursora do Amiloide/efeitos dos fármacos , Calcitriol/farmacologia , Proteínas Quinases JNK Ativadas por Mitógeno/efeitos dos fármacos , Proteínas de Membrana/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Receptor para Produtos Finais de Glicação Avançada/efeitos dos fármacos , Vitaminas/farmacologia , Proteína ADAM10/antagonistas & inibidores , Proteína ADAM10/metabolismo , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Western Blotting , Regulação para Baixo , Ensaio de Imunoadsorção Enzimática , Átrios do Coração/citologia , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/metabolismo , Camundongos , Miócitos Cardíacos/metabolismo , NF-kappa B/antagonistas & inibidores , Reação em Cadeia da Polimerase em Tempo Real , Receptor para Produtos Finais de Glicação Avançada/genética , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Ventricular arrhythmias commonly arise from the right (RVOT) and left ventricular outflow tracts (LVOT) in patients without structural heart disease. Heart failure (HF) significantly increases the risk of ventricular arrhythmias. The regional differences and how HF affects the electrophysiological characteristics of RVOT and LVOT cardiomyocytes remain unclear. The whole-cell patch-clamp technique was used to investigate the action potentials and ionic currents in isolated single RVOT and LVOT cardiomyocytes from control rabbits and rabbits with HF induced by rapid ventricular pacing. Comparison with control LVOT cardiomyocytes showed that control RVOT cardiomyocytes have a shorter action potential duration (APD), smaller late Na+ currents (INa-late), larger transient outward (Ito) and larger delayed rectifier K+ currents (IKr-tail), but had similar L-type Ca2+ currents (ICa-L) and Na+/Ca2+ exchanger (NCX) current. HF increased APD, INa-late and NCX, but decreased ICa-L and Ito in RVOT cardiomyocytes. In contrast with this, HF decreased APD and ICa-L, but increased Ito and IKr-tail in LVOT cardiomyocytes. In conclusion, RVOT and LVOT cardiomyocytes had distinctive electrophysiological characteristics. HF differentially modulates action potential morphology and ionic currents in RVOT and LVOT cardiomyocytes.
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Arritmias Cardíacas/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/fisiopatologia , Miócitos Cardíacos/metabolismo , Função Ventricular Esquerda , Função Ventricular Direita , Potenciais de Ação , Animais , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/patologia , Canais de Cálcio Tipo L/metabolismo , Sinalização do Cálcio , Estimulação Cardíaca Artificial , Forma Celular , Canais de Potássio de Retificação Tardia/metabolismo , Modelos Animais de Doenças , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/patologia , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Masculino , Miócitos Cardíacos/patologia , Técnicas de Patch-Clamp , Coelhos , Canais de Sódio/metabolismo , Trocador de Sódio e Cálcio/metabolismo , Fatores de TempoRESUMO
Diabetic cardiomyopathy is a major complication of diabetes mellitus (DM). Currently, effective treatments for diabetic cardiomyopathy are limited. The pathophysiology of diabetic cardiomyopathy is complex, whereas mitochondrial dysfunction plays a vital role in the genesis of diabetic cardiomyopathy. Metabolic regulation targeting mitochondrial dysfunction is expected to be a reasonable strategy for treating diabetic cardiomyopathy. Peroxisome proliferator-activated receptors (PPARs) are master executors in regulating glucose and lipid homeostasis and also modulate mitochondrial function. However, synthetic PPAR agonists used for treating hyperlipidemia and DM have shown controversial effects on cardiovascular regulation. This article reviews our updated understanding of the beneficial and detrimental effects of PPARs on mitochondria in diabetic hearts.
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Cardiomiopatias Diabéticas/metabolismo , Mitocôndrias Cardíacas/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Animais , Cardiomiopatias Diabéticas/tratamento farmacológico , Glucose/metabolismo , Humanos , Hiperlipidemias/tratamento farmacológico , Hiperlipidemias/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/agonistasRESUMO
Interleukin (IL)-33, a cytokine involved in immune responses, can activate its receptor, suppression of tumorigenicity 2 (ST2), is elevated during atrial fibrillation (AF). However, the role of IL-33/ST2 signaling in atrial arrhythmia is unclear. This study explored the pathological effects of the IL-33/ST2 axis on atrial remodeling and arrhythmogenesis. Patch clamping, confocal microscopy, and Western blotting were used to analyze the electrical characteristics of and protein activity in atrial myocytes (HL-1) treated with recombinant IL-33 protein and/or ST2-neutralizing antibodies for 48 hrs. Telemetric electrocardiographic recordings, Masson's trichrome staining, and immunohistochemistry staining of the atrium were performed in mice receiving tail vein injections with nonspecific immunoglobulin (control), IL-33, and IL-33 combined with anti-ST2 antibody for 2 weeks. IL-33-treated HL-1 cells had a reduced action potential duration, lower L-type Ca2+ current, greater sarcoplasmic reticulum (SR) Ca2+ content, increased Na+/Ca2+ exchanger (NCX) current, elevation of K+ currents, and increased intracellular calcium transient. IL-33-treated HL-1 myocytes had greater activation of the calcium-calmodulin-dependent protein kinase II (CaMKII)/ryanodine receptor 2 (RyR2) axis and nuclear factor kappa B (NF-κB) / NLR family pyrin domain containing 3 (NLRP3) signaling than did control cells. IL-33 treated cells also had greater expression of Nav1.5, Kv1.5, NCX, and NLRP3 than did control cells. Pretreatment with neutralizing anti-ST2 antibody attenuated IL-33-mediated activation of CaMKII/RyR2 and NF-κB/NLRP3 signaling. IL-33-injected mice had more atrial ectopic beats and increased AF episodes, greater atrial fibrosis, and elevation of NF-κB/NLRP3 signaling than did controls or mice treated with IL-33 combined with anti-ST2 antibody. Thus, IL-33 recombinant protein treatment promotes atrial remodeling through ST2 signaling. Blocking the IL-33/ST2 axis might be an innovative therapeutic approach for patients with atrial arrhythmia and elevated serum IL-33.
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Remodelamento Atrial , Interleucina-33 , Miócitos Cardíacos , Animais , Masculino , Camundongos , Potenciais de Ação/efeitos dos fármacos , Arritmias Cardíacas/fisiopatologia , Arritmias Cardíacas/metabolismo , Fibrilação Atrial/fisiopatologia , Fibrilação Atrial/metabolismo , Remodelamento Atrial/efeitos dos fármacos , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Linhagem Celular , Átrios do Coração/fisiopatologia , Átrios do Coração/metabolismo , Átrios do Coração/efeitos dos fármacos , Átrios do Coração/patologia , Proteína 1 Semelhante a Receptor de Interleucina-1/metabolismo , Interleucina-33/metabolismo , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Transdução de SinaisRESUMO
INTRODUCTION: The accumulation of microbiota-derived trimethylamine N-oxide (TMAO) in the atrium is linked to the development and progression of atrial arrhythmia. Butyrate, a major short-chain fatty acid, plays a crucial role in sustaining intestinal homeostasis and alleviating systemic inflammation, which may reduce atrial arrhythmogenesis. OBJECTIVES: This study explored the roles of butyrate in regulating TMAO-mediated atrial remodeling and arrhythmia. METHODS: Whole-cell patch clamp experiments, Western blotting, and immunocytochemistry were used to analyze electrical activity and signaling, respectively, in TMAO-treated HL-1 atrial myocytes with or without sodium butyrate (SB) administration. Telemetry electrocardiographic recording and echocardiography and Masson's trichrome staining and immunohistochemistry were employed to examine atrial function and histopathology, respectively, in mice treated with TMAO with and without SB administration. RESULTS: Compared with control cells, TMAO-treated HL-1 myocytes exhibited reduced action potential duration (APD), elevated sarcoplasmic reticulum (SR) calcium content, larger L-type calcium current (ICa-L), increased Na+/Ca2+ exchanger (NCX) current, and increased potassium current. However, the combination of SB and TMAO resulted in similar APD, SR calcium content, ICa-L, transient outward potassium current (Ito), and ultrarapid delayed rectifier potassium current (IKur) compared with controls. Additionally, TMAO-treated HL-1 myocytes exhibited increased activation of endoplasmic reticulum (ER) stress signaling, along with increased PKR-like ER stress kinase (PERK)/IRE1α axis activation and expression of phospho-IP3R, NCX, and Kv1.5, compared with controls or HL-1 cells treated with the combination of TMAO and SB. TMAO-treated mice exhibited atrial ectopic beats, impaired atrial function, increased atrial fibrosis, and greater activation of ER stress signaling with PERK/IRE1α axis activation compared with controls and mice treated with TMAO combined with SB. CONCLUSION: TMAO administration led to PERK/IRE1α axis activation, which may increase atrial remodeling and arrhythmogenesis. SB treatment mitigated TMAO-elicited ER stress. This finding suggests that SB administration is a valuable strategy for treating TMAO-induced atrial arrhythmia.
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OBJECTIVE: To present an atypical manifestation in a patient with pheochromocytoma. CLINICAL PRESENTATION AND INTERVENTION: A 48-year-old man presented with chest pain, fever and leukocytosis. Elevated cardiac biomarkers and diffuse ST-T abnormalities on electrocardiography suggested myocardial infarction. However, coronary angiography showed normal coronary arteries. Abdominal computed tomography revealed a left adrenal tumor of 6.7 × 6.8 cm. Paroxysmal fluctuation of blood pressure raised the suspicion of pheochromocytoma, which was further supported by elevated urine catecholamine levels. He underwent left adrenalectomy and pathological findings confirmed the diagnosis. CONCLUSION: Pheochromocytoma should be considered as part of the differential diagnosis in a patient with symptoms suggestive of both acute coronary syndrome and sepsis.
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Neoplasias das Glândulas Suprarrenais/diagnóstico , Feocromocitoma/diagnóstico , Síndrome Coronariana Aguda/diagnóstico , Neoplasias das Glândulas Suprarrenais/cirurgia , Adrenalectomia , Proteína C-Reativa/análise , Catecolaminas/urina , Dor no Peito/etiologia , Angiografia Coronária , Diagnóstico Diferencial , Eletrocardiografia , Febre/etiologia , Humanos , Leucocitose/etiologia , Masculino , Pessoa de Meia-Idade , Feocromocitoma/cirurgia , Sepse/diagnóstico , Troponina I/sangueRESUMO
Vitamin D deficiency is associated with hyperlipidemia, but it remains unclear whether vitamin D supplementation reduces serum lipid levels. The aims of this study were to investigate the associations between increased serum 25-hydroxyvitamin D (25(OH)D) concentrations and lipid levels and identify the characteristics of people with or without lipid reduction associated with increased 25(OH)D levels. The medical records of 118 individuals (53 men; mean age, 54.4 ± 10.6 years) whose serum 25(OH)D levels increased between 2 consecutive measurements were retrospectively reviewed. People with increased 25(OH)D levels (from 22.7 (17.6-29.2) to 32.1 (25.6-36.8) mg/dL; P < 0.01) had a significant reduction in serum levels of triglycerides (TGs) (from 111.0 (80-164) to 104.5 (73-142) mg/dL; P < 0.01) and total cholesterol (TC) (from 187.5 (155-213) to 181.0 (150-210) mg/dL; P < 0.05). The individuals who responded to vitamin D (≥10% reduction in TG or TC levels) exhibited significantly higher baseline TG and TC levels than those who did not. Only patients with hyperlipidemia (not those without hyperlipidemia) at baseline exhibited significantly reduced TG and TC levels at follow-up. However, increasing serum 25(OH)D concentrations were significantly correlated with decreasing lipid levels in individuals with baseline 25(OH)D levels less than 30 ng/mL and in individuals aged 50-65 years (not in patients younger than 50 years or older than 65 years). In conclusion, increasing serum 25(OH)D concentrations may be potentially helpful for the treatment of hyperlipidemia in people with vitamin D deficiency.
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The ketogenic diet (KD) might improve cardiac function in diabetic cardiomyopathy, but the mechanisms remain unclear. This study investigated the effects of KD on myocardial fatty acid (FA), glucose, and ketone metabolism in diabetic cardiomyopathy. Echocardiograms, biochemistry, and micro-positron emission tomography were performed to evaluate cardiac function and glucose uptake in control rats and streptozotocin-induced diabetes mellitus (DM) rats with normal diet (ND) or KD for 6 weeks. Histopathology, adenosine triphosphate measurement, and Western blot were performed in the ventricular myocytes to analyze fibrosis, FA, ketone body, and glucose utilization. The ND-fed DM rats exhibited impaired left ventricular systolic function and increased chamber dilatation, whereas control and KD-fed DM rats did not. The KD reduced myocardial fibrosis and apoptosis in the DM rats. Myocardial glucose uptake in the micro-positron emission tomography was similar between ND-fed DM rats and KD-fed DM rats and was substantially lower than the control rats. Compared with the control rats, ND-fed DM rats had increased phosphorylation of acetyl CoA carboxylase and higher expressions of CD-36, carnitine palmitoyltransferase-1ß, tumor necrosis factor-α, interleukin-1ß, interleukin6, PERK, and e-IF2α as well as more myocardial fibrosis and apoptosis (assessed by Bcl-2, BAX, and caspase-3 expression); these increases were attenuated in the KD-fed DM rats. Moreover, ND-fed DM rats had significantly lower myocardial adenosine triphosphate, BHB, and OXCT1 levels than the control and KD-fed DM rats. The KD may improve the condition of diabetic cardiomyopathy by suppressing FA metabolism, increasing ketone utilization, and decreasing endoplasmic reticulum stress and inflammation.