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1.
Nat Commun ; 11(1): 4666, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938943

RESUMO

Intercalated discs (ICD), specific cell-to-cell contacts that connect adjacent cardiomyocytes, ensure mechanical and electrochemical coupling during contraction of the heart. Mutations in genes encoding ICD components are linked to cardiovascular diseases. Here, we show that loss of Xinß, a newly-identified component of ICDs, results in cardiomyocyte proliferation defects and cardiomyopathy. We uncovered a role for Xinß in signaling via the Hippo-YAP pathway by recruiting NF2 to the ICD to modulate cardiac function. In Xinß mutant hearts levels of phosphorylated NF2 are substantially reduced, suggesting an impairment of Hippo-YAP signaling. Cardiac-specific overexpression of YAP rescues cardiac defects in Xinß knock-out mice-indicating a functional and genetic interaction between Xinß and YAP. Our study reveals a molecular mechanism by which cardiac-expressed intercalated disc protein Xinß modulates Hippo-YAP signaling to control heart development and cardiac function in a tissue specific manner. Consequently, this pathway may represent a therapeutic target for the treatment of cardiovascular diseases.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas do Citoesqueleto/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas com Domínio LIM/metabolismo , Miócitos Cardíacos/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Cardiomiopatia Dilatada/genética , Comunicação Celular , Proteínas de Ciclo Celular/genética , Proliferação de Células , Proteínas do Citoesqueleto/genética , Proteínas de Ligação a DNA/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Ventrículos do Coração/crescimento & desenvolvimento , Proteínas com Domínio LIM/genética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Miócitos Cardíacos/citologia , Miócitos Cardíacos/patologia , Neurofibromina 2/genética , Neurofibromina 2/metabolismo , Proteínas Nucleares/genética , Transdução de Sinais
2.
Nature ; 584(7820): 279-285, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32760005

RESUMO

In pathophysiology, reactive oxygen species oxidize biomolecules that contribute to disease phenotypes1. One such modification, 8-oxoguanine2 (o8G), is abundant in RNA3 but its epitranscriptional role has not been investigated for microRNAs (miRNAs). Here we specifically sequence oxidized miRNAs in a rat model of the redox-associated condition cardiac hypertrophy4. We find that position-specific o8G modifications are generated in seed regions (positions 2-8) of selective miRNAs, and function to regulate other mRNAs through o8G•A base pairing. o8G is induced predominantly at position 7 of miR-1 (7o8G-miR-1) by treatment with an adrenergic agonist. Introducing 7o8G-miR-1 or 7U-miR-1 (in which G at position 7 is substituted with U) alone is sufficient to cause cardiac hypertrophy in mice, and the mRNA targets of o8G-miR-1 function in affected phenotypes; the specific inhibition of 7o8G-miR-1 in mouse cardiomyocytes was found to attenuate cardiac hypertrophy. o8G-miR-1 is also implicated in patients with cardiomyopathy. Our findings show that the position-specific oxidation of miRNAs could serve as an epitranscriptional mechanism to coordinate pathophysiological redox-mediated gene expression.


Assuntos
Cardiomegalia/genética , Cardiomegalia/patologia , Inativação Gênica , MicroRNAs/química , MicroRNAs/metabolismo , Animais , Pareamento de Bases , Linhagem Celular , Modelos Animais de Doenças , Guanina/análogos & derivados , Guanina/análise , Guanina/química , Guanina/metabolismo , Humanos , Camundongos , MicroRNAs/genética , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Oxirredução , Ratos , Transcrição Genética/genética , Transcriptoma/genética
3.
Vascul Pharmacol ; 133-134: 106781, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32827678

RESUMO

INTRODUCTION: Stem cell-derived cardiac myocytes are potential sources for testing cardiocytoprotective molecules against ischemia/reperfusion injury in vitro. MATERIALS AND METHODS: Here we performed a systematic analysis of two different induced pluripotent stem cell lines (iPSC 3.4 and 4.1) and an embryonic stem cell (ESC) line-derived cardiac myocytes at two different developmental stages. Cell viability in simulated ischemia/reperfusion (SI/R)-induced injury and a known cardiocytoprotective NO-donor, S-nitroso-n-acetylpenicillamine (SNAP) was tested. RESULTS: After analysis of full embryoid bodies (EBs) and cardiac marker (VCAM and cardiac troponin I) positive cells of three lines at 6 conditions (32 different conditions altogether), we found significant SI/R injury-induced cell death in both full EBs and VCAM+ cardiac cells at later stage of their differentiation. Moreover, full EBs of the iPS 4.1 cell line after oxidative stress induction by SNAP was protected at day-8 samples. CONCLUSION: We have shown that 4.1 iPS-derived cardiomyocyte line could serve as a testing platform for cardiocytoprotection.


Assuntos
Diferenciação Celular , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miócitos Cardíacos/efeitos dos fármacos , Doadores de Óxido Nítrico/farmacologia , Células-Tronco Pluripotentes/efeitos dos fármacos , S-Nitroso-N-Acetilpenicilamina/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Estresse Oxidativo/efeitos dos fármacos , Fenótipo , Células-Tronco Pluripotentes/metabolismo , Células-Tronco Pluripotentes/patologia , Troponina I/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo
4.
PLoS One ; 15(8): e0237305, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32822421

RESUMO

Diabetes can elicit direct deleterious effects on the myocardium, independent of coronary artery disease or hypertension. These cardiac disturbances are termed diabetic cardiomyopathy showing increased risk of heart failure with or without reduced ejection fraction. Presently, there is no specific treatment for this type of cardiomyopathy and in the case of type I diabetes, it may start in early childhood independent of glycemic control. We hypothesized that alterations in isolated myocyte contractility and cardiac function are present in the early stages of experimental diabetes in rats before overt changes in myocardium structure occur. Diabetes was induced by single-dose injection of streptozotocin (STZ) in rats with data collected from control and diabetic animals 3 weeks after injection. Left ventricle myocyte contractility was measured by single-cell length variation under electrical stimulation. Cardiac function and morphology were studied by high-resolution echocardiography with pulsed-wave tissue Doppler imaging (TDI) measurements and three-lead surface electrocardiogram. Triglycerides, cholesterol and liver enzyme levels were measured from plasma samples obtained from both groups. Myocardial collagen content and perivascular fibrosis of atria and ventricle were studied by histological analysis after picrosirius red staining. Diabetes resulted in altered contractility of isolated cardiac myocytes with increased contraction and relaxation time intervals. Echocardiography showed left atrium dilation, increased end-diastolic LV and posterior wall thickness, with reduced longitudinal systolic peak velocity (S') of the septum mitral annulus at the apical four-chamber view obtained by TDI. Triglycerides, aspartate aminotransferase and alkaline phosphatase were elevated in diabetic animals. Intertitial collagen content was higher in atria of both groups and did not differ among control and diabetic animals. Perivascular intramyocardial arterioles collagen did not differ between groups. These results suggest that alterations in cardiac function are present in the early phase in this model of diabetes type 1 and occur before overt changes in myocardium structure appear as evaluated by intersticial collagen deposition and perivascular fibrosis of intramyocardial arterioles.


Assuntos
Diabetes Mellitus Tipo 1/fisiopatologia , Cardiomiopatias Diabéticas/fisiopatologia , Contração Miocárdica , Miócitos Cardíacos/patologia , Animais , Células Cultivadas , Diabetes Mellitus Tipo 1/induzido quimicamente , Diabetes Mellitus Tipo 1/patologia , Cardiomiopatias Diabéticas/induzido quimicamente , Cardiomiopatias Diabéticas/patologia , Ratos , Estreptozocina
5.
PLoS One ; 15(8): e0236457, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790682

RESUMO

Transgenic mice with selective induction of calreticulin transgene expression in cardiomyocytes (CardiacCRT+) were analyzed. CardiacCRT+ cardiomyocytes showed increased contractility and Ca2+ transients. Yet, in vivo assessment of cardiac performance, and ischemic tolerance of CardiacCRT+ mice demonstrated right ventricle dilation and reduced cardiac output, increased QT interval and decreased P amplitude. Paradoxically, ex vivo working hearts from CardiacCRT+ mice showed enhanced ischemic cardio-protection and cardiac efficiency. Under aerobic conditions, CardiacCRT+ hearts showed less efficient cardiac function than sham control hearts due to an increased ATP production from glycolysis relative to glucose oxidation. During reperfusion, this inefficiency was reversed, with CardiacCRT+ hearts exhibiting better functional recovery and increased cardiac efficiency compared to sham control hearts. On the other hand, mechanical stretching of isolated cardiac fibroblasts activated the IRE1α branch of the unfolded protein response pathway as well as induction of Col1A2 and TGFß gene expression ex vivo, which were all suppressed by tauroursodeoxycholic acid.


Assuntos
Calreticulina/metabolismo , Contração Miocárdica , Isquemia Miocárdica/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Calreticulina/genética , Células Cultivadas , Metabolismo Energético , Frequência Cardíaca , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Isquemia Miocárdica/genética , Isquemia Miocárdica/fisiopatologia , Miócitos Cardíacos/patologia , Regulação para Cima
6.
Am J Physiol Heart Circ Physiol ; 319(2): H443-H455, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32618511

RESUMO

Neuregulin-1 (NRG1) is a paracrine growth factor, secreted by cardiac endothelial cells (ECs) in conditions of cardiac overload/injury. The current concept is that the cardiac effects of NRG1 are mediated by activation of erythroblastic leukemia viral oncogene homolog (ERBB)4/ERBB2 receptors on cardiomyocytes. However, recent studies have shown that paracrine effects of NRG1 on fibroblasts and macrophages are equally important. Here, we hypothesize that NRG1 autocrine signaling plays a role in cardiac remodeling. We generated EC-specific Erbb4 knockout mice to eliminate endothelial autocrine ERBB4 signaling without affecting paracrine NRG1/ERBB4 signaling in the heart. We first observed no basal cardiac phenotype in these mice up to 32 wk. We next studied these mice following transverse aortic constriction (TAC), exposure to angiotensin II (ANG II), or myocardial infarction in terms of cardiac performance, myocardial hypertrophy, myocardial fibrosis, and capillary density. In general, no major differences between EC-specific Erbb4 knockout mice and control littermates were observed. However, 8 wk following TAC both myocardial hypertrophy and fibrosis were attenuated by EC-specific Erbb4 deletion, albeit these responses were normalized after 20 wk. Similarly, 4 wk after ANG II treatment, myocardial fibrosis was less pronounced compared with control littermates. These observations were supported by RNA-sequencing experiments on cultured endothelial cells showing that NRG1 controls the expression of various hypertrophic and fibrotic pathways. Overall, this study shows a role of endothelial autocrine NRG1/ERBB4 signaling in the modulation of hypertrophic and fibrotic responses during early cardiac remodeling. This study contributes to understanding the spatiotemporal heterogeneity of myocardial autocrine and paracrine responses following cardiac injury.NEW & NOTEWORTHY The role of NRG1/ERBB signaling in endothelial cells is not completely understood. Our study contributes to the understanding of spatiotemporal heterogeneity of myocardial autocrine and paracrine responses following cardiac injury and shows a role of endothelial autocrine NRG1/ERBB4 signaling in the modulation of hypertrophic and fibrotic responses during early cardiac remodeling.


Assuntos
Comunicação Autócrina , Cardiomiopatias/metabolismo , Células Endoteliais/metabolismo , Hipertrofia Ventricular Esquerda/metabolismo , Infarto do Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Neuregulina-1/metabolismo , Receptor ErbB-4/metabolismo , Função Ventricular Esquerda , Remodelação Ventricular , Animais , Cardiomiopatias/genética , Cardiomiopatias/patologia , Cardiomiopatias/fisiopatologia , Células Cultivadas , Modelos Animais de Doenças , Fibrose , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Hipertrofia Ventricular Esquerda/genética , Hipertrofia Ventricular Esquerda/patologia , Hipertrofia Ventricular Esquerda/fisiopatologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Miócitos Cardíacos/patologia , Neovascularização Fisiológica , Comunicação Parácrina , Receptor ErbB-4/deficiência , Receptor ErbB-4/genética , Transdução de Sinais
7.
Am J Physiol Heart Circ Physiol ; 319(2): H410-H421, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32648820

RESUMO

Cardiac t tubules undergo significant remodeling in various pathological and experimental conditions, which can be associated with mechanical or osmotic stress. In particular, it has been shown that removal of hyposmotic stress can lead to sealing of t tubules. However, the mechanisms underlying the sealing process remain essentially unknown. In this study we used dextran trapping assay to demonstrate that in adult mouse cardiomyocytes, t-tubular sealing can also be induced by hyperosmotic challenge and that both hypo- and hyperosmotic sealing display a clear threshold behavior requiring ≈100 mosmol/L minimal stress. Importantly, during both hypo- and hyperosmotic challenges, the sealing of t tubules occurs only during the shrinking phase. Analysis of the time course of t-tubular remodeling following removal of hyposmotic stress shows that t tubules become sealed essentially instantly, well before any significant reduction in cell size can be observed. Overall, the data support the hypothesis that the critical event in the process of t-tubular sealing during osmotic challenges is detachment (peeling) of the membrane from the underlying cytoskeleton due to suprathreshold stress.NEW & NOTEWORTHY This study provides new insights into how t-tubular membranes respond to osmotic forces. In particular, the data show that osmotically induced sealing of cardiac t tubules is a threshold phenomenon initiated by detachment of t-tubular membrane from the underlying cytoskeleton. The findings are consistent with the hypothesis that final sealing of t tubules is driven by negative hydrostatic intracellular pressure coincident with cell shrinking.


Assuntos
Membrana Celular/patologia , Tamanho Celular , Citoesqueleto/patologia , Miócitos Cardíacos/patologia , Pressão Osmótica , Vacúolos/patologia , Animais , Membrana Celular/metabolismo , Citoesqueleto/metabolismo , Feminino , Masculino , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/metabolismo , Fatores de Tempo , Vacúolos/metabolismo
8.
Cardiovasc Pathol ; 49: 107256, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32721819

RESUMO

BACKGROUND: Heart failure is a frequently occurring complication in patients on maintenance hemodialysis (HD). However, the histological features of right ventricular endomyocardial biopsy (RVEMB) samples remain unclear. METHODS: The clinical characteristics and histological findings of consecutive patients undergoing HD with available RVEMB samples (HD group; n=28) were retrospectively compared with those of patients with dilated cardiomyopathy (n=56) and hypertensive heart disease (n=15). RESULTS: The mean myocyte diameter was significantly larger in the HD group than in the other groups (P<.001), whereas the mean percent area of fibrosis did not differ among the three groups. Immunohistochemical analysis revealed that the capillary density was significantly lower in the HD group compared with the other groups (P<.001), and it was positively associated with left ventricular ejection fraction (P=.014). The number of CD68-positive macrophages, which was significantly higher in the HD group compared with the other two groups (P<.001), was associated with cardiovascular mortality (P=.020; log-rank test). CONCLUSIONS: Myocyte hypertrophy, macrophage infiltration, and reduced capillary density were characteristic histological features of the RVEMB samples in patients undergoing HD, which may be related to the pathogenesis of cardiac dysfunction.


Assuntos
Cardiomiopatias/patologia , Cardiomiopatia Dilatada/patologia , Miocárdio/patologia , Diálise Renal , Insuficiência Renal Crônica/terapia , Adulto , Idoso , Biópsia , Capilares/patologia , Cardiomiopatias/etiologia , Cardiomiopatias/fisiopatologia , Cardiomiopatia Dilatada/fisiopatologia , Tamanho Celular , Feminino , Fibrose , Humanos , Hipertensão/complicações , Macrófagos/patologia , Masculino , Pessoa de Meia-Idade , Miócitos Cardíacos/patologia , Valor Preditivo dos Testes , Diálise Renal/efeitos adversos , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/diagnóstico , Estudos Retrospectivos , Fatores de Risco
9.
PLoS Comput Biol ; 16(7): e1008048, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32658888

RESUMO

Heart failure (HF) is associated with an increased propensity for atrial fibrillation (AF), causing higher mortality than AF or HF alone. It is hypothesized that HF-induced remodelling of atrial cellular and tissue properties promotes the genesis of atrial action potential (AP) alternans and conduction alternans that perpetuate AF. However, the mechanism underlying the increased susceptibility to atrial alternans in HF remains incompletely elucidated. In this study, we investigated the effects of how HF-induced atrial cellular electrophysiological (with prolonged AP duration) and tissue structural (reduced cell-to-cell coupling caused by atrial fibrosis) remodelling can have an effect on the generation of atrial AP alternans and their conduction at the cellular and one-dimensional (1D) tissue levels. Simulation results showed that HF-induced atrial electrical remodelling prolonged AP duration, which was accompanied by an increased sarcoplasmic reticulum (SR) Ca2+ content and Ca2+ transient amplitude. Further analysis demonstrated that HF-induced atrial electrical remodelling increased susceptibility to atrial alternans mainly due to the increased sarcoplasmic reticulum Ca2+-ATPase (SERCA) Ca2+ reuptake, modulated by increased phospholamban (PLB) phosphorylation, and the decreased transient outward K+ current (Ito). The underlying mechanism has been suggested that the increased SR Ca2+ content and prolonged AP did not fully recover to their previous levels at the end of diastole, resulting in a smaller SR Ca2+ release and AP in the next beat. These produced Ca2+ transient alternans and AP alternans, and further caused AP alternans and Ca2+ transient alternans through Ca2+→AP coupling and AP→Ca2+ coupling, respectively. Simulation of a 1D tissue model showed that the combined action of HF-induced ion channel remodelling and a decrease in cell-to-cell coupling due to fibrosis increased the heart tissue's susceptibility to the formation of spatially discordant alternans, resulting in an increased functional AP propagation dispersion, which is pro-arrhythmic. These findings provide insights into how HF promotes atrial arrhythmia in association with atrial alternans.


Assuntos
Remodelamento Atrial , Insuficiência Cardíaca/fisiopatologia , Potenciais de Ação , Algoritmos , Animais , Fibrilação Atrial/fisiopatologia , Sinalização do Cálcio , Proteínas de Ligação ao Cálcio/metabolismo , Simulação por Computador , Cães , Condutividade Elétrica , Átrios do Coração/fisiopatologia , Ventrículos do Coração/fisiopatologia , Humanos , Camundongos , Modelos Cardiovasculares , Contração Miocárdica , Miócitos Cardíacos/patologia , Fosforilação , Retículo Sarcoplasmático/metabolismo
10.
PLoS One ; 15(7): e0232963, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730272

RESUMO

Mammalian cardiomyocytes exit the cell cycle shortly after birth. As a result, an occurrence of coronary occlusion-induced myocardial infarction often results in heart failure, postinfarction LV dilatation, or death, and represents one of the most significant public health morbidities worldwide. Interestingly however, the hearts of neonatal pigs have been shown to regenerate following an acute myocardial infarction (MI) occuring on postnatal day 1 (P1); a recovery period which is accompanied by an increased expression of markers for cell-cycle activity, and suggests that early postnatal myocardial regeneration may be driven in part by the MI-induced proliferation of pre-existing cardiomyocytes. In this study, we identified signaling pathways known to regulate the cell cycle, and determined of these, the pathways persistently upregulated in response to MI injury. We identified five pathways (mitogen associated protein kinase [MAPK], Hippo, cyclic [cAMP], Janus kinase/signal transducers and activators of transcription [JAK-STAT], and Ras) which were comprehensively upregulated in cardiac tissues collected on day 7 (P7) and/or P28 of the P1 injury hearts. Several of the initiating master regulators (e.g., CSF1/CSF1R, TGFB, and NPPA) and terminal effector molecules (e.g., ATF4, FOS, RELA/B, ITGB2, CCND1/2/3, PIM1, RAF1, MTOR, NKF1B) in these pathways were persistently upregulated at day 7 through day 28, suggesting there exists at least some degree of regenerative activity up to 4 weeks following MI at P1. Our observations provide a list of key regulators to be examined in future studies targeting cell-cycle activity as an avenue for myocardial regeneration.


Assuntos
Infarto do Miocárdio/patologia , Miócitos Cardíacos/patologia , Animais , Animais Recém-Nascidos , AMP Cíclico/metabolismo , Sistema de Sinalização das MAP Quinases , Infarto do Miocárdio/metabolismo , Suínos , Fatores de Tempo
11.
Adv Exp Med Biol ; 1207: 731-736, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32671790

RESUMO

Several major cardiovascular diseases, such as heart failure (HF) and atherosclerosis (AS), have been linked to autophagy dysfunction. The influence of autophagy on the occurrence and development of cardiovascular diseases has two sides. Generally, the induction of autophagy at a low level can provide energy and nutrients for cells through degradation of damaged organelles, protect cardiomyocytes and vascular endothelial cells, and stabilize atherosclerotic plaques. However, excessive autophagy may damage cardiomyocytes and vascular endothelial cells and even cause cell death. Therefore, the study on the role and mechanism of autophagy in the pathogenesis of cardiovascular diseases may not only provide new targets for the treatment of cardiac remodeling, myocardial ischemia and reperfusion injury, atherosclerosis and heart failure, but also provide clues for the developing new drugs on prevention and treatment of clinical cardiovascular diseases. In this chapter, we reviewed the research progress on resveratrol, curcumin, epigallocatechin-3-gallate, and cordyceps sinensis on their recent research progress for cardiovascular diseases. Regulating autophagy may be an effective strategy for the treatment of cardiovascular diseases in the future.


Assuntos
Autofagia/efeitos dos fármacos , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/patologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Humanos , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia
12.
Life Sci ; 257: 118084, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32663572

RESUMO

Since an outbreak of vaping-related deaths in the US has been reported as a public health crisis, the cardiovascular safety of nicotine nowadays receives increasing attention due to use of tobacco cigarette alternatives, such as electronic cigarettes. However, whether and how nicotine contributes to cardiac detrimental effects are in great controversy, especially less understood in young adult population. We report that chronic nicotine exposure, a major component of Electronic cigarettes, resulted in directly inhibited cardiomyocytes viability, increased cardiac fibrosis, and markedly suppressed cardiac function compared with sham. Gene array combined with bioinformatics analysis identified cardiac apoptosis and mitophagy were the key signals responsible for nicotine induced cardiac detrimental effect. Mechanistically, nicotine exposure markedly increased cleaved Caspase 3 and cleaved Caspase 9 indicating the involvement of intrinsic apoptotic pathway (mitochondrial cell death pathway). Meanwhile, nicotine-induced ROS outbreak promoted lysomal alkalization, furthermore blocked mitophagic degradation, thereby disrupted mitophagic flux promoted mitochondrial cell death cascade. Taken together, these findings indicate that nicotine confers cardiotoxicity via ROS-induced mitophagic flux blockage and provide the first demonstration of a causative link between nicotine and cardiac toxicity in young adult rat which may suggest nicotine induces cardiomyocytes impairment leading to cardiotoxicity in young adult population.


Assuntos
Apoptose/efeitos dos fármacos , Cardiotoxicidade/etiologia , Mitofagia/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Nicotina/toxicidade , Animais , Cardiotoxicidade/fisiopatologia , Sistemas Eletrônicos de Liberação de Nicotina , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Miócitos Cardíacos/patologia , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Vaping/efeitos adversos
13.
Life Sci ; 257: 118074, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32673667

RESUMO

AIM: Doxorubicin (DOX) induces dose-dependent cardiotoxicity due to reactive oxygen species (ROS)-mediated oxidative stress and subsequent apoptosis of cardiomyocytes. We aimed to assess whether sodium thiosulfate (STS), which has antioxidant and antiapoptotic properties, exerts cardioprotective effects on DOX-induced cardiomyopathy. MAIN METHODS: Male C57BL/6N mice were divided into four groups, control, DOX, STS, and DOX + STS, and administered DOX (20 or 30 mg/kg) or normal saline intraperitoneally, followed by an injection of STS (2 g/kg) or normal saline 4 h later. KEY FINDINGS: The DOX group showed a poorer 6-day survival and decreased cardiac function than the DOX + STS group. The DOX group showed a marked increase in the plasma creatine kinase isoenzyme myocardial band (CK-MB) and lactate dehydrogenase (LDH) levels 10 h after DOX injection, while the DOX + STS group showed suppression of DOX-induced elevation of CK-MB and LDH levels. The DOX group showed increased 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in the heart, whereas the DOX + STS group showed increased catalase and superoxide dismutase (SOD) activities and decreased 8-OHdG levels in the heart compared with DOX group, suggesting that STS reduces DOX-induced DNA damage by improving antioxidant enzymes activities in cardiomyocytes. Additionally, the DOX + STS group showed attenuation of cleaved caspase-3 and DNA fragmentation in cardiomyocytes compared with the DOX group, suggesting that STS suppresses DOX-induced apoptosis in cardiomyocytes. SIGNIFICANCE: STS exerts cardioprotective effects against DOX-induced cardiac dysfunction partly by improving antioxidant defense and suppressing apoptosis, indicating the therapeutic potential of STS against DOX-induced cardiomyopathy.


Assuntos
Cardiotoxicidade/prevenção & controle , Dano ao DNA/efeitos dos fármacos , Doxorrubicina/toxicidade , Miócitos Cardíacos/efeitos dos fármacos , Tiossulfatos/farmacologia , Animais , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/toxicidade , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Cardiotoxicidade/etiologia , Relação Dose-Resposta a Droga , Doxorrubicina/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/patologia , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
14.
Cardiovasc Pathol ; 48: 107224, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32480283

RESUMO

OBJECTIVE: We used automated image analysis software to determine the proportion of collagen, fat, and myocytes across six histological regions of normal ventricular myocardium. METHODS: Twenty-nine non-cardiac death cases referred to our national cardiac pathology center were included in this study. Whole hearts were macroscopically and microscopically normal following expert histopathological evaluation. Tissue sections from the right ventricular outflow tract, right ventricle (RV), anterior interventricular septum (IVS), posterior IVS, anterior left ventricle (LV), and posterior LV were stained with Picrosirius red for collagen and scanned using a high-resolution slide scanner. Quantification of collagen, fat, and myocyte proportions was performed using Visiopharm software after automated exclusion of perivascular collagen. RESULTS: The majority of decedents were male (25/29; 86%) with a mean age at death of 32.1 ± 9.9 (range 18-54) and mean BMI 28.7 ± 7.3. We report predicted values (collagen %, fat %, myocytes %) for cardiac tissue composition within the RV, IVS, and LV (including epicardial and endocardial layers). The proportion of collagen and fat were higher in the RV compared with the LV (ratios 1.61 [1.45-1.78]; 2.63 [1.99-3.48], respectively) and RV compared with the IVS (ratios 1.77 [1.60-1.97]; 8.41[6.35-11.13], respectively). The ratio of epicardial versus endocardial fat was increased in both ventricles (RV: ratio 4.49 [3.67-5.49]; LV: ratio 3.46 [2.49-4.81]). In multivariable analysis, there was no significant association between collagen or fat proportion and sex (p=0.12; p=0.08, respectively), age at death (p=0.36; p=0.23, respectively), or BMI (p=0.45; p=0.43, respectively). CONCLUSIONS: Our findings provide location and sex-specific proportions of myocardial histological tissue composition that may aid quantitative evaluation of pathology in future studies.


Assuntos
Tecido Adiposo/patologia , Colágeno/análise , Ventrículos do Coração/química , Ventrículos do Coração/patologia , Miócitos Cardíacos/química , Miócitos Cardíacos/patologia , Adolescente , Adulto , Autopsia , Feminino , Fibrose , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Adulto Jovem
15.
Cardiovasc Ther ; 2020: 2016259, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32528555

RESUMO

Background: Myocardial infarction (MI) was a severe cardiovascular disease resulted from acute, persistent hypoxia, or ischemia condition. Additionally, MI generally led to heart failure, even sudden death. A multitude of research studies proposed that long noncoding RNAs (lncRNAs) frequently participated in the regulation of heart diseases. The specific function and molecular mechanism of SOX2-OT in MI remained unclear. Aim of the Study. The current research was aimed to explore the role of SOX2-OT in MI. Methods: Bioinformatics analysis (DIANA tools and Targetscan) and a wide range of experiments (CCK-8, flow cytometry, RT-qPCR, luciferase reporter, RIP, caspase-3 activity, trans-well, and western blot assays) were adopted to investigate the function and mechanism of SOX2-OT. Results: We discovered that hypoxia treatment decreased cell viability but increased cell apoptosis. Besides, lncRNA SOX2-OT expression was upregulated in hypoxic HCMs. Hereafter, we confirmed that SOX2-OT could negatively regulate miR-27a-3p levels by directly binding with miR-27a-3p, and miR-27a-3p also could negatively regulate SOX2-OT levels. Furthermore, knockdown of SOX2-OT promoted cell proliferation, migration, and invasion, but limited cell apoptosis. However, these effects were reversed by anti-miR-27a-5p. Besides, we verified that miR-27a-3p binding with the 3'UTR of TGFBR1 and SOX2-OT regulated TGFßR1 level by collaborating with miR-27a-3p in HCMs. Eventually, rescue assays validated that the influence of SOX2-OT silence or miR-27a-3p overexpression on cellular processes in cardiomyocytes injury was counteracted by TGFBR1 overexpression. Conclusions: Long noncoding RNA SOX2-OT exacerbated hypoxia-induced cardiomyocytes injury by regulating miR-27a-3p/TGFßR1 axis, which may provide a novel insight for heart failure treatment.


Assuntos
Insuficiência Cardíaca/metabolismo , MicroRNAs/metabolismo , Infarto do Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , RNA Longo não Codificante/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I/metabolismo , Apoptose , Hipóxia Celular , Movimento Celular , Proliferação de Células , Células Cultivadas , Regulação da Expressão Gênica , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Humanos , MicroRNAs/genética , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Miócitos Cardíacos/patologia , RNA Longo não Codificante/genética , Receptor do Fator de Crescimento Transformador beta Tipo I/genética , Transdução de Sinais
16.
Life Sci ; 253: 117723, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: covidwho-133616

RESUMO

Coronavirus Disease 2019 (COVID-19) has quickly progressed to a global health emergency. Respiratory illness is the major cause of morbidity and mortality in these patients with the disease spectrum ranging from asymptomatic subclinical infection, to severe pneumonia progressing to acute respiratory distress syndrome. There is growing evidence describing pathophysiological resemblance of SARS-CoV-2 infection with other coronavirus infections such as Severe Acute Respiratory Syndrome coronavirus and Middle East Respiratory Syndrome coronavirus (MERS-CoV). Angiotensin Converting Enzyme-2 receptors play a pivotal role in the pathogenesis of the virus. Disruption of this receptor leads to cardiomyopathy, cardiac dysfunction, and heart failure. Patients with cardiovascular disease are more likely to be infected with SARS-CoV-2 and they are more likely to develop severe symptoms. Hypertension, arrhythmia, cardiomyopathy and coronary heart disease are amongst major cardiovascular disease comorbidities seen in severe cases of COVID-19. There is growing literature exploring cardiac involvement in SARS-CoV-2. Myocardial injury is one of the important pathogenic features of COVID-19. As a surrogate for myocardial injury, multiple studies have shown increased cardiac biomarkers mainly cardiac troponins I and T in the infected patients especially those with severe disease. Myocarditis is depicted as another cause of morbidity amongst COVID-19 patients. The exact mechanisms of how SARS-CoV-2 can cause myocardial injury are not clearly understood. The proposed mechanisms of myocardial injury are direct damage to the cardiomyocytes, systemic inflammation, myocardial interstitial fibrosis, interferon mediated immune response, exaggerated cytokine response by Type 1 and 2 helper T cells, in addition to coronary plaque destabilization, and hypoxia.


Assuntos
Betacoronavirus/fisiologia , Infecções por Coronavirus/patologia , Miocárdio/patologia , Pneumonia Viral/patologia , Infecções por Coronavirus/imunologia , Humanos , Miocardite/virologia , Miócitos Cardíacos/patologia , Miócitos Cardíacos/virologia , Pandemias , Pneumonia Viral/imunologia
17.
Life Sci ; 255: 117849, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32473249

RESUMO

AIMS: The associations between colorectal neoplasia differentially expressed (CRNDE), a novel long non-coding RNA (lncRNA), and inflammation and cell apoptosis have been underscored recently. However, its function in sepsis-induced myocardial injury remains undetermined. The current study sets to examine the putative mechanism of CRNDE in myocardial injury evoked by sepsis. MATERIALS AND METHODS: Firstly, the rat model of sepsis was developed and verified. Subsequently, differentially expressed lncRNAs in myocardial tissues of septic rats were determined. Afterwards, CRNDE overexpression or knockdown was introduced into the myocardial tissues of rats. Then, H9c2 cells were induced by lipopolysaccharide (LPS) and transfected with overexpression of CRNDE and sirtuin 1 (SIRT1), si-CRNDE or microRNA (miR)-29a mimic. Apoptosis, Caspase-3 activity, secretion of inflammatory factors, and intracellular reactive oxygen species (ROS) content were subsequently measured in rat tissues and transfected cells. Finally, the NF-κB/PARP-1 signaling activity in rat myocardial tissues and cells was detected. KEY FINDINGS: CRNDE expression was reduced in the myocardial tissues of rats with sepsis, and CRNDE restoration alleviated following myocardial injury. Additionally, overexpression of CRNDE inhibited cardiomyocyte apoptosis, ROS content, Caspase-3 activity, nuclear NF-κB p65 phosphorylation and PARP-1 expression. Dual-luciferase assays showed that the CRNDE/miR-29a/SIRT1 network regulated sepsis-induced myocardial injury. Moreover, miR-29a mimic attenuated the protective effect of CRNDE overexpression on LPS-induced cardiomyocytes. SIGNIFICANCE: CRNDE protects the myocardial tissues against sepsis-induced cardiomyocyte apoptosis and oxidative damage by inhibiting the post-transcriptional regulatory function of miR-29a on SIRT1.


Assuntos
MicroRNAs/genética , Miocárdio/patologia , RNA Longo não Codificante/genética , Sepse/fisiopatologia , Sirtuína 1/genética , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Inflamação/genética , Inflamação/patologia , Lipopolissacarídeos , Masculino , Miócitos Cardíacos/patologia , NF-kappa B/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Sepse/genética
18.
J Vis Exp ; (159)2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32449739

RESUMO

Ischemic heart disease is a significant cause of death worldwide. It has therefore been the subject of a tremendous amount of research, often with small-animal models such as rodents. However, the physiology of the human heart differs significantly from that of the rodent heart, underscoring the need for clinically relevant models to study heart disease. Here, we present a protocol to model ischemic heart disease using cardiomyocytes differentiated from human induced pluripotent stem cells (hiPS-CMs) and to quantify the damage and functional impairment of the ischemic cardiomyocytes. Exposure to 2% oxygen without glucose and serum increases the percentage of injured cells, which is indicated by staining of the nucleus with propidium iodide, and decreases cellular viability. These conditions also decrease the contractility of hiPS-CMs as confirmed by displacement vector field analysis of microscopic video images. This protocol may furthermore provide a convenient method for personalized drug screening by facilitating the use of hiPS cells from individual patients. Therefore, this model of ischemic heart disease, based on iPS-CMs of human origin, can provide a useful platform for drug screening and further research on ischemic heart disease.


Assuntos
Células-Tronco Pluripotentes Induzidas/citologia , Contração Miocárdica , Isquemia Miocárdica/patologia , Isquemia Miocárdica/fisiopatologia , Miócitos Cardíacos/patologia , Animais , Diferenciação Celular , Sobrevivência Celular , Modelos Animais de Doenças , Humanos , Microscopia de Vídeo , Isquemia Miocárdica/diagnóstico por imagem
19.
Am J Physiol Heart Circ Physiol ; 319(1): H109-H122, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32442025

RESUMO

Although cell therapy-mediated cardiac repair offers promise for treatment/management of heart failure, lack of fundamental understanding of how cell therapy works limits its translational potential. In particular, whether reparative cells from failing hearts differ from cells derived from nonfailing hearts remains unexplored. Here, we assessed differences between cardiac mesenchymal cells (CMC) derived from failing (HF) versus nonfailing (Sham) hearts and whether the source of donor cells (i.e., from HF vs. Sham) limits reparative capacity, particularly when administered late after infarction. To determine the impact of the donor source of CMCs, we characterized the transcriptional profile of CMCs isolated from sham (Sham-CMC) and failing (HF-CMC) hearts. RNA-seq analysis revealed unique transcriptional signatures in Sham-CMC and HF-CMC, suggesting that the donor source impacts CMC. To determine whether the donor source affects reparative potential, C57BL6/J female mice were subjected to 60 min of regional myocardial ischemia and then reperfused for 35 days. In a randomized, controlled, and blinded fashion, vehicle, HF-CMC, or Sham-CMC were injected into the lumen of the left ventricle at 35 days post-MI. An additional 5 weeks later, cardiac function was assessed by echocardiography, which indicated that delayed administration of Sham-CMC and HF-CMC attenuated ventricular dilation. We also determined whether Sham-CMC and HF-CMC treatments affected ventricular histopathology. Our data indicate that the donor source (nonfailing vs. failing hearts) affects certain aspects of CMC, and these insights may have implications for future studies. Our data indicate that delayed administration of CMC limits ventricular dilation and that the source of CMC may influence their reparative actions.NEW & NOTEWORTHY Most preclinical studies have used only cells from healthy, nonfailing hearts. Whether donor condition (i.e., heart failure) impacts cells used for cell therapy is not known. We directly tested whether donor condition impacted the reparative effects of cardiac mesenchymal cells in a chronic model of myocardial infarction. Although cells from failing hearts differed in multiple aspects, they retained the potential to limit ventricular remodeling.


Assuntos
Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/patologia , Traumatismo por Reperfusão Miocárdica/terapia , Função Ventricular , Animais , Células Cultivadas , Feminino , Ventrículos do Coração/citologia , Ventrículos do Coração/patologia , Masculino , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Contração Miocárdica , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Transcriptoma
20.
Arch Biochem Biophys ; 689: 108405, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32439330

RESUMO

Cardiac hypertrophy is an adaptive response to hemodynamic stress to compensate for cardiac dysfunction. MicroRNAs can regulate cardiac function and play a vital role in the regulation of cardiac hypertrophy. In the current study, in vivo and vitro hypertrophy models are established to explore the role of miR-27b and to elucidate the underlying mechanism in cardiac hypertrophy. Expression of miR-27b was down-regulated in mice with cardiac hypertrophy. The cardiac function of the mice with cardiac hypertrophy could be restored with the overexpression of miR-27b, this is observed in terms of decreasing LVEDd, LVESd, and increasing LVFS, LVEF. This study also predicted and confirmed that galectin-3 is a target gene of miR-27b. Depletion of galectin-3 significantly attenuated hypertrophy of hearts in both in vitro and in vivo tests. In conclusion, MiR-27b be used to exert a protective role against cardiac dysfunction and hypertrophy by decreasing the expression level of galectin-3. The methodology suggested in this study provides a novel therapeutic strategy against cardiac hypertrophy.


Assuntos
Cardiomegalia/genética , Galectina 3/genética , MicroRNAs/genética , Miócitos Cardíacos/patologia , Animais , Cardiomegalia/patologia , Células Cultivadas , Regulação para Baixo , Masculino , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/metabolismo , Regulação para Cima
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