Mecanismos compensatorios a nivel sistémico en pacientes con tronco arterial persistente / Systemic Compensatory Mechanisms in Patients with Persistent Truncus Arteriosus

Resumen Introducción: El tronco arterial persistente es una rara malformación cardíaca congénita que provoca diversas complicaciones en el sistema cardiovascular. Se caracteriza por la presencia de un tabique ventricular defectuoso, una única válvula troncal y un tronco arterial común entre la arteria pulmonar y aorta, conllevando a una mezcla entre la sangre arterial y venosa, debido a un cortocircuito cardíaco bidireccional predominante de izquierda a derecha que compromete el suministro de flujo sanguíneo, nutrientes y oxigenación sistémica. Las manifestaciones clínicas incluyen desaturación con cianosis, hipoxemia, taquicardia, taquipnea, alteraciones en la contractilidad cardíaca, pulsos distales anómalos, pérdida de peso, fatiga y hepatomegalia. Objetivo: El propósito de esta investigación es establecer hipótesis sobre los diversos mecanismos compensatorios que se activan a nivel sistémico para contrarrestar los efectos de esta malformación. Reflexión: Se sugiere que se producen respuestas biomoleculares similares en los sistemas cardiovascular, pulmonar y renal, reduciendo la producción de óxido nítrico y provocando respuestas vasoconstrictoras. A nivel hepático, se generan factores de crecimiento y se inician procesos de angiogénesis para aumentar la perfusión sanguínea. En el cerebro, se activan enzimas para incrementar el flujo sanguíneo y proporcionar oxígeno y nutrientes esenciales. Conclusión: A pesar de estos mecanismos compensatorios, no logran contrarrestar por completo las manifestaciones clínicas, conduciendo a una serie de problemas de salud, como hipertensión pulmonar, insuficiencia cardíaca, hepatomegalia, hipoperfusión de órganos y déficits neurológicos. Estos factores convergen para generar una compleja condición cardíaca que desencadena respuestas adaptativas en el cuerpo que terminan siendo una afección médica desafiante y potencialmente grave.

Abstract Introduction: Persistent truncus arteriosus is a rare congenital cardiac malformation that causes various complications in the cardiovascular system. It is characterized by the presence of a defective ventricular septum, a single truncal valve and a common truncus arteriosus between the pulmonary artery and aorta, leading to a mixture between arterial and venous blood, due to a predominantly left-to-right bidirectional cardiac shunt that compromises the supply of blood flow, nutrients, and systemic oxygenation. Clinical manifestations include desaturation with cyanosis, hypoxemia, tachycardia, tachypnea, alterations in cardiac contractility, abnormal distal pulses, weight loss, fatigue, and hepatomegaly. Aim: The purpose of this research is to establish hypotheses about the various compensatory mechanisms that are activated at a systemic level to counteract the effects of this malformation. Reflection: It is suggested that similar biomolecular responses occur in the cardiovascular, pulmonary, and renal systems, reducing nitric oxide production and causing vasoconstrictive responses. At the liver level, growth factors are generated and angiogenesis processes are initiated to increase blood perfusion. In the brain, enzymes are activated to increase blood flow and provide oxygen and essential nutrients. Conclusion: Despite these compensatory mechanisms, they fail to completely counteract the clinical manifestations, leading to a series of health problems such as pulmonary hypertension, heart failure, hepatomegaly, organ hypoperfusion, and neurological deficits. These factors converge to generate a complex cardiac condition that triggers adaptive responses in the body that end up being a challenging and potentially serious medical condition.

O Treinamento Resistido Atenua a Remodelação Cardíaca Induzida por uma Dieta Hiperlipídica em Roedores: Uma Revisão Sistemática / Resistance Exercise Training Mitigates Cardiac Remodeling Induced by a High-Fat Diet in Rodents: A Systematic Review

Resumo Fundamento A obesidade está associada ao desenvolvimento de doenças cardiovasculares e constitui um grave problema de saúde pública. Em modelos animais, a alimentação com uma dieta hiperlipídica (DH) compromete a estrutura e a função cardíaca e promove estresse oxidativo e apoptose. O treinamento resistido (TR), entretanto, tem sido recomendado como coadjuvante no tratamento de doenças cardiometabólicas, incluindo a obesidade, porque aumenta o gasto energético e estimula a lipólise. Objetivo Na presente revisão sistemática, nosso objetivo foi avaliar os benefícios do TR no coração de ratos e camundongos alimentados com DH. Métodos Foram identificados estudos originais por meio de busca nas bases de dados PubMed, Scopus e Embase de dezembro de 2007 a dezembro de 2022. O presente estudo foi conduzido de acordo com os critérios estabelecidos pelo PRISMA e registrado no PROSPERO (CRD42022369217). O risco de viés e a qualidade metodológica foram avaliados pelo SYRCLE e CAMARADES, respectivamente. Os estudos elegíveis incluíram artigos originais publicados em inglês que avaliaram desfechos cardíacos em roedores submetidos a mais de 4 semanas de TR e controlados por um grupo controle sedentário alimentado com DH (n = 5). Resultados Os resultados mostraram que o TR atenua o estresse oxidativo cardíaco, a inflamação e o estresse do retículo endoplasmático. Também modifica a atividade de marcadores de remodelamento estrutural, apesar de não alterar parâmetros biométricos, parâmetros histomorfométricos ou a função contrátil dos cardiomiócitos. Conclusão Nossos resultados indicam que o TR parcialmente neutraliza o remodelamento cardíaco adverso induzido pela DH, aumentando a atividade dos marcadores de remodelamento estrutural; elevando a biogênese mitocondrial; reduzindo o estresse oxidativo, marcadores inflamatórios e estresse do retículo endoplasmático; e melhorando os parâmetros hemodinâmicos, antropométricos e metabólicos.

Abstract Background Obesity is associated with the development of cardiovascular diseases and is a serious public health problem. In animal models, high-fat diet (HFD) feeding impairs cardiac structure and function and promotes oxidative stress and apoptosis. Resistance exercise training (RT), however, has been recommended as coadjutant in the treatment of cardiometabolic diseases, including obesity, because it increases energy expenditure and stimulates lipolysis. Objective In this systematic review, we aimed to assess the benefits of RT on the heart of rats and mice fed HFD. Methods Original studies were identified by searching PubMed, Scopus, and Embase databases from December 2007 to December 2022. This study was conducted in accordance with the criteria established by PRISMA and registered in PROSPERO (CRD42022369217). The risk of bias and methodological quality was evaluated by SYRCLE and CAMARADES, respectively. Eligible studies included original articles published in English that evaluated cardiac outcomes in rodents submitted to over 4 weeks of RT and controlled by a sedentary, HFD-fed control group (n = 5). Results The results showed that RT mitigates cardiac oxidative stress, inflammation, and endoplasmic reticulum stress. It also modifies the activity of structural remodeling markers, although it does not alter biometric parameters, histomorphometric parameters, or the contractile function of cardiomyocytes. Conclusion Our results indicate that RT partially counteracts the HFD-induced adverse cardiac remodeling by increasing the activity of structural remodeling markers; elevating mitochondrial biogenesis; reducing oxidative stress, inflammatory markers, and endoplasmic reticulum stress; and improving hemodynamic, anthropometric, and metabolic parameters.

Developmental toxicity of Cry1Ab protein in the embryonic stem-cell model / 北京大学学报(医学版)

Objective:To evaluate the developmental toxicity of Cry1Ab protein by studying its effects on cell proliferation and differentiation ability using a developmental toxicity assessment model based on embryonic stem-cell.Methods:Cry1Ab protein was tested in seven dose groups(31.25,62.50,125.00,250.00,320.00,1 000.00,and 2 000.00 μg/L)on mouse embryonic stem cells D3(ES-D3)and 3T3 mouse fibroblast cells,with 5-fluorouracil(5-FU)used as the positive control and phos-phate buffer saline(PBS)as the solvent control.Cell viability was detected by CCK-8 assay to calculate the 50％inhibitory concentration(IC50)of the test substance for different cells.Additionally,Cry1 Ab protein was tested in five dose groups(125.00,250.00,320.00,1 000.00,and 2 000.00 μg/L)on ES-D3 cells,with PBS as the solvent control and 5-FU used for model validation.After cell treatment,cardiac differentiation was induced using the embryonic bodies(EBs)culture method.The growth of EBs was observed under a microscope,and their diameters on the third and fifth days were measured.The proportion of EBs differentiating into beating cardiomyocytes was recorded,and the 50％inhibition con-centration of differentiation(ID50)was calculated.Based on a developmental toxicity discrimination func-tion,the developmental toxicity of the test substances was classified.Furthermore,at the end of the cul-ture period,mRNA expression levels of cardiac differentiation-related markers(Oct3/4,GATAA-4,Nkx2.5,and β-MHC)were quantitatively detected using real-time quantitative polymerase chain reaction(qPCR)in the collected EBs samples.Results:The IC50 of 5-FU was determined as 46.37 μg/L in 3T3 cells and 32.67 μg/L in ES-D3 cells,while the ID50 in ES-D3 cells was 21.28 μg/L.According to the discrimination function results,5-FU was classified as a strong embryotoxic substance.There were no sta-tistically significant differences in cell viability between different concentrations of Cry 1 Ab protein treat-ment groups and the control group in both 3T3 cells and ES-D3 cells(P＞0.05).Moreover,there were no statistically significant differences in the diameter of EBs on the third and fifth days,as well as their morphology,between the Cry1Ab protein treatment groups and the control group(P＞0.05).The cardi-ac differentiation rate showed no statistically significant differences between different concentrations of Cry1Ab protein treatment groups and the control group(P＞0.05).5-FU significantly reduced the mRNA expression levels of β-MHC,Nkx2.5,and GATA-4(P＜0.05),showing a dose-dependent trend(P＜0.05),while the mRNA expression levels of the pluripotency-associated marker Oct3/4 exhibited an increasing trend(P＜0.05).However,there were no statistically significant differences in the mRNA expression levels of mature cardiac marker β-MHC,early cardiac differentiation marker Nkx2.5 and GATA-4,and pluripotency-associated marker Oct3/4 between the Cry1Ab protein treatment groups and the control group(P＞0.05).Conclusion:No developmental toxicity of Cry1Ab protein at concen-trations ranging from 31.25 to 2 000.00 μg/L was observed in this experimental model.

Efeito Protetor do RNA Não Codificante Longo OXCT1-AS1 na Apoptose de Células Miocárdicas Humanas Induzida pela Doxorrubicina pelo Padrão Competitivo de RNA Endógeno / Protective Effect of Long Noncoding RNA OXCT1-AS1 on Doxorubicin-Induced Apoptosis of Human Myocardial Cells by the Competitive Endogenous RNA Pattern

Resumo Fundamento: O antibiótico quimioterápico antraciclina doxorrubicina (DOX) pode induzir cardiotoxicidade cumulativa e levar à disfunção cardíaca. RNAs não codificantes longos (lncRNAs) podem funcionar como importantes reguladores na lesão miocárdica induzida por DOX. Objetivo: Este estudo tem como objetivo investigar o papel funcional e o mecanismo molecular do RNA antisense lncRNA OXCT1 1 (OXCT1-AS1) na lesão celular miocárdica induzida por DOX in vitro. Métodos: Cardiomiócitos humanos (AC16) foram estimulados com DOX para induzir um modelo de lesão celular miocárdica. A expressão de OXCT1-AS1, miR-874-3p e BDH1 em células AC16 foi determinada por RT-qPCR. A viabilidade das células AC16 foi medida pelo ensaio XTT. A citometria de fluxo foi empregada para avaliar a apoptose de células AC16. Western blotting foi utilizado para avaliar os níveis proteicos de marcadores relacionados à apoptose. O ensaio repórter de luciferase dupla foi conduzido para verificar a capacidade de ligação entre miR-874-3p e OXCT1-AS1 e entre miR-874-3p e BDH1. O valor de p<0,05 indicou significância estatística. Resultados: A expressão de OXCT1-AS1 foi diminuída em células AC16 tratadas com DOX. A superexpressão de OXCT1-AS1 reverteu a redução da viabilidade celular e a promoção da apoptose celular causada pela DOX. OXCT1-AS1 está ligado competitivamente ao miR-874-3p para regular positivamente o BDH1. A superexpressão de BDH1 restaurou a viabilidade das células AC16 e suprimiu a apoptose celular sob estimulação com DOX. A derrubada do BDH1 reverteu a atenuação da apoptose de células AC16 mediada por OXCT1-AS1 sob tratamento com DOX. Conclusão: LncRNA OXCT1-AS1 protege células miocárdicas humanas AC16 da apoptose induzida por DOX através do eixo miR-874-3p/BDH1.

Abstract Background: The anthracycline chemotherapeutic antibiotic doxorubicin (DOX) can induce cumulative cardiotoxicity and lead to cardiac dysfunction. Long non-coding RNAs (lncRNAs) can function as important regulators in DOX-induced myocardial injury. Objective: This study aims to investigate the functional role and molecular mechanism of lncRNA OXCT1 antisense RNA 1 (OXCT1-AS1) in DOX-induced myocardial cell injury in vitro. Methods: Human cardiomyocytes (AC16) were stimulated with DOX to induce a myocardial cell injury model. OXCT1-AS1, miR-874-3p, and BDH1 expression in AC16 cells were determined by RT-qPCR. AC16 cell viability was measured by XTT assay. Flow cytometry was employed to assess the apoptosis of AC16 cells. Western blotting was used to evaluate protein levels of apoptosis-related markers. Dual-luciferase reporter assay was conducted to verify the binding ability between miR-874-3p and OXCT1-AS1 and between miR-874-3p and BDH1. The value of p<0.05 indicated statistical significance. Results: OXCT1-AS1 expression was decreased in DOX-treated AC16 cells. Overexpression of OXCT1-AS1 reversed the reduction of cell viability and promotion of cell apoptosis caused by DOX. OXCT1-AS1 is competitively bound to miR-874-3p to upregulate BDH1. BDH1 overexpression restored AC16 cell viability and suppressed cell apoptosis under DOX stimulation. Knocking down BDH1 reversed OXCT1-AS1-mediated attenuation of AC16 cell apoptosis under DOX treatment. Conclusion: LncRNA OXCT1-AS1 protects human myocardial cells AC16 from DOX-induced apoptosis via the miR-874-3p/BDH1 axis.

Metabolic Crosstalk between the Heart and Fat

It is now recognized that the heart can behave as a true endocrine organ, which can modulate the function of other tissues. Emerging evidence has shown that visceral fat is one such distant organ the heart communicates with. In fact, it appears that bi-directional crosstalk between adipose tissue and the myocardium is crucial to maintenance of normal function in both organs. In particular, factors secreted from the heart are now known to influence the metabolic activity of adipose tissue and other organs, as well as modulate the release of metabolic substrates and signaling molecules from the periphery. This review summarizes current knowledge regarding primary cardiokines and adipokines involved in heart-fat crosstalk, as well as implications of their dysregulation for cardiovascular health.

A glucose-insulin-potassium solution improves glucose intake in hypoxic cardiomyocytes by a differential expression of glucose transporters in a metabolic syndrome model

Among the last consequences of metabolic syndrome are cardiovascular complications such as infarcts. The hypoxic heartswitches its lipid-based metabolism to carbohydrates, and a glucose-insulin-potassium (GIK) solution can be the metabolicsupport to protect the organ. Due to the physiology and cardiac risks associated with the metabolic syndrome, we studied theeffect of GIK solution during hypoxia in a metabolic syndrome model by observing the participation of glucose transporters(GLUTs). The metabolic syndrome characteristics were established by giving a 30% sucrose drinking solution to Wistar ratsfor 24 weeks. The GIK solution’s effect on myocyte glucose uptake during hypoxia and oxygenation was observed using acolorimetric method, and Western blot technique visualized the GLUT participation. Oxygenated control myocytes consumed1.7 ± 0.2 µg of glucose per gram of fresh tissue per hour using the GLUT1, and during hypoxia, they incorporated 41.1%more glucose by GLUT1 and GLUT4. The GIK solution improved glucose uptake in oxygenation by 70.5% through GLUT1.In hypoxia, the uptake was 21% more than the hypoxic control group and by both GLUTs too. Oxygenated metabolicsyndrome myocytes uptake was similar to control cells but achieved by both carriers in oxygenation and hypoxia. Also, theGIK solution had a better response in both oxygenation (113%) and hypoxia (71%). Despite the metabolic energy disorders ofthis syndrome, the GIK solution protects cardiomyocytes, in conditions of hypoxia, through the modulation of both GLUTs.So, this solution can be considered a useful resource during a heart attack in cases of metabolic syndrome.

Protective effects of curcumin on oxidative stress injury of H9C2 cardiac myocytes induced by H2O2 / 国际中医中药杂志

Objective To study the protective effects of curcumin on oxidative stress injury of H9C2 cardiac myocytes induced by H2O2.Methods The oxidative stress injury model in H9C2 cardiac myocytes was established in vitro, and cells were divided into the control group, H2O2 group (200μmol/L), low- (10μmol/L), medium- (20μmol/L), high- (40μmol/L) dose curcumin, and each group set six holes. After H2O2 stimulation for 24 h, the morphology changes were observed by microscope, and the survival rates were measured using CCK8 method. The activity of LDH, CK, and AST, and the content of MDA in culture medium were detected, and the activities of SOD, CAT, and GSH-Px in cardiac myocytes were also determined.Results Compared with the H2O2 group, the activity of LDH (247.36 ± 28.04 U/L, 195.14 ± 21.37 U/L, 132.27 ± 16.33 U/Lvs. 247.58± 28.34 U/L), AST (67.27 ± 10.58 U/ml, 54.81 ± 8.60 U/ml, 42.14 ± 5.95 U/mlvs.84.34 ± 12.36 U/ml), CK (1.34 ± 0.66 U/ml, 0.95 ± 0.42 U/ml, 0.71 ± 0.39 U/ml vs.1.56 ± 0.74 U/ml) and the content of MDA (227.39 ± 32.05 nmol/ml, 185.11 ± 24.37 nmol/ml, 143.50 ± 16.37 nmol/mlvs. 274.19 ± 36.51 nmol/ml) in culture medium of curcumin were significantly decreased (P<0.05). The morphology of H9C2 cardiac myocytes in curcumin group was improved, the survival rate was significantly increased (P<0.05). The activity of SOD (17.67± 1.36 U/mg, 21.54 ± 1.72 U/mg, 28.37 ± 2.36 U/mgvs. 14.37 ± 1.22 U/mg), CAT (19.58 ± 3.87 U/mg, 25.34 ± 4.06 U/mg, 30.21 ± 4.83 U/mgvs. 14.77 ± 3.25 U/mg) and GSH-Px (1.99 ± 1.17 U/mg, 2.56 ± 1.29 U/mg, 3.04 ± 0.45 U/mgvs. 1.67 ± 0.87 U/mg) in cardiac myocytes were significantly increased (P<0.05). Conclusions Curcumin can effectively improve oxidative stress injury of H9C2 cardiac myocytes induced by H2O2, and curcumin has dose-dependent protective effects against the oxidative stress of H9C2 cardiac myocytes induced by H2O2.

Melatonin-Induced Protective Effects on Cardiomyocytes Against Reperfusion Injury Partly Through Modulation of IP3R and SERCA2a Via Activation of ERK1 / Efeitos Protetores Induzidos pela Melatonina nos Cardiomiócitos Contra Lesões de Reperfusão Parcialmente Através da Modulação Dde IP3R e SERCA por Meio da Ativação de ERK1

Resumo Background: Melatonin is a neuroendocrine hormone synthesized primarily by the pineal gland that is indicated to effectively prevent myocardial reperfusion injury. It is unclear whether melatonin protects cardiac function from reperfusion injury by modulating intracellular calcium homeostasis. Objective: Demonstrate that melatonin protect against myocardial reperfusion injury through modulating IP3R and SERCA2a to maintain calcium homeostasis via activation of ERK1 in cardiomyocytes. Methods: In vitro experiments were performed using H9C2 cells undergoing simulative hypoxia/reoxygenation (H/R) induction. Expression level of ERK1, IP3R and SERCA2a were assessed by Western Blots. Cardiomyocytes apoptosis was detected by TUNEL. Phalloidin-staining was used to assess alteration of actin filament organization of cardiomyocytes. Fura-2 /AM was used to measure intracellular Ca2+ concentration. Performing in vivo experiments, myocardial expression of IP3R and SERCA2a were detected by immunofluorescence staining using myocardial ischemia/ reperfusion (I/R) model in rats. Results: In vitro results showed that melatonin induces ERK1 activation in cardiomyocytes against H/R which was inhibited by PD98059 (ERK1 inhibitor). The results showed melatonin inhibit apoptosis of cardiomyocytes and improve actin filament organization in cardiomyocytes against H/R, because both could be reversed by PD98059. Melatonin was showed to reduce calcium overload, further to inhibit IP3R expression and promote SERCA2a expression via ERK1 pathway in cardiomyocytes against H/R. Melatonin induced lower IP3R and higher SERCA2a expression in myocardium that were reversed by PD98059. Conclusion: melatonin-induced cardioprotection against reperfusion injury is at least partly through modulation of IP3R and SERCA2a to maintain intracellular calcium homeostasis via activation of ERK1.

Resumo Fundamento: A melatonina é um hormônio neuroendócrino sintetizado principalmente pela glândula pineal que é indicado para prevenir efetivamente a lesão de reperfusão miocárdica. Não está claro se a melatonina protege a função cardíaca da lesão de reperfusão através da modulação da homeostase do cálcio intracelular. Objetivo: Demonstrar que a melatonina protege contra a lesão de reperfusão miocárdica através da modulação de IP3R e SERCA para manter a homeostase de cálcio por meio da ativação de ERK1 em cardiomiócitos. Métodos: Foram realizados experimentos in vitro usando células H9C2 submetidas a indução de hipoxia / reoxigenação simulada (H/R). O nível de expressão de ERK1, IP3R e SERCA foi avaliado por Western Blots. A apoptose de cardiomiócitos foi detectada por TUNEL. A coloração de faloidina foi utilizada para avaliar a alteração da organização de filamentos de actina dos cardiomiócitos. Fura-2 / AM foi utilizado para medir a concentração intracelular de Ca2+. Realizando experiências in vivo, a expressão miocárdica de IP3R e SERCA foi detectada por coloração com imunofluorescência usando modelo de isquemia miocárdica / reperfusão (I/R) em ratos. Resultados: resultados in vitro mostraram que a melatonina induz a ativação de ERK1 em cardiomiócitos contra H/R que foi inibida por PD98059 (inibidor de ERK1). Os resultados mostraram que a melatonina inibe a apoptose dos cardiomiócitos e melhora a organização do filamento de actina em cardiomiócitos contra H/R, pois ambas poderiam ser revertidas pela PD98059. A melatonina mostrou reduzir a sobrecarga de cálcio, além de inibir a expressão de IP3R e promover a expressão de SERCA através da via ERK1 em cardiomiócitos contra H/R. A melatonina induziu menor IP3R e maior expressão de SERCA no miocárdio que foram revertidas pela PD98059. Conclusão: a cardioproteção induzida pela melatonina contra lesão de reperfusão é pelo menos parcialmente através da modulação de IP3R e SERCA para manter a homeostase de cálcio intracelular via ativação de ERK1.

CFTR in Cardiovascular Functions / 中山大学学报(医学科学版)

Cystic fibrosis transmembrane conductance regulator(CFTR)is an ATP-gated,cAMP-dependent chloride channel. The basic biophysical and pathological functions of CFTR are related with the secretion of chloride ion in epithelial cells and tissues. Mutations in CFTR cause cystic fibrosis(CF),which is a rare but fatal autosomal recessive inheritant disease ,mainly affecting glan?dular epithelial function in respiratory tract ,intestinal and reproductive system. New drugs targeting human CFTR gene mutations have been developed to significantly prolong lifeand improve respiratory symptoms of CF patients. Recent evidence suggested that CFTR plays a functional role in vasoconstriction and the formation of myocardial action potential. As a channel protein ,CFTR may al?so functions as a multiprotein/channel complex ,which has been demonstrated in the development of cardiovascular diseases such as myocardial ischemia and pulmonary hypertension.

Protective effect of epigallocatechin-3-gallate on hypoxia/reoxygenation injury in cardiac myocytes and its mechanism / 中国药理学通报

Aim To observe the protective effect of epigallocatechin-3-gallate (EGCG) on hypoxia/reoxygenation (H/R) injury of cardiac myocytes and its mechanisms.Methods H9c2 cardiac myocytes were cultured in vitro and randomly divided into five groups:normal group(N group),H/R group,EGCG low dose group (L group),EGCG medium dose group (M group),and EGCG high dose group(H group).The cardiomyocyte H/R injury model was established and EGCG was pretreated.Cell survival rate was tested by CCK-8 method.The cell apoptotic rate was detected using Annexin V-FITC/PI double staining.The contents of total antioxidant capacity(T-AOC) and tumor necrosis factor α(TNF-α) in cell culture medium were tested according to the kit instructions.The protein expression of Akt and p-Akt was observed using Western blot,while the gene expressions of PI3K,Akt,caspase3 were detected by using fluorescence quantitative PCR method.Results Compared with model group,EGCG increased cell survival rate and reduced the apoptosis after H/R injury.Meanwhile,pretreatment EGCG improved the activity of T-AOC,reduced the level of TNF-α,up-regulated the expression of PI3K,Akt and p-Akt,and down-regulated the expression of caspase3.Conclusion EGCG reduces apoptosis and protects cardiac myocytes by influencing PI3K/Akt signal path

N-n-butyl haloperidol iodide protectsH9c2 cardiac myocytes against hypoxia/reoxygenationinjury through mitochondria-dependent apoptotic pathway / 中国药理学通报

Aim To investigate the effect of N-n-butyl haloperidol iodide(F2) on mitochondria-dependent apoptotic pathway of H9c2 cardiac myocytes during hypoxia/reoxygenation(H/R) injury.Methods The H/R models of H9c2 cardiac myocytes were established.The H9c2 cardiac myocytes were randomly divided into five groups: control group(C group), hypoxia/reoxygenation group(H/R group), F2 low concentration group(L), F2 medium concentration group(M), F2 high concentration group(H).Apoptotic rate was evaluated by flow cytometry(FCM).The levels of Cyto C, Bcl-2, Bax were observed by Western blot.Caspase-3 activity was measured with colorimetry.Results Compared with H/R group, F2 low, medium and high concentrations group could significantly decrease apoptosis rate and increase the ratio of Bcl-2 to Bax proteins and inhibit the release of Cyto C into the cytosolic fraction, and decrease caspase-3 activity.Conclusion F2 can protect H9c2 cardiac myocytes against H/R-induced injury through interfering in mitochondria-dependent pathway.

Análise histomorfométrica dos cardiomiócitos e deposição de colágeno no músculo cardíaco de ratas ooforectomizadas / Histomorphometric analysis of cardiomyocytes and collagen deposition in the heart muscle of ovariectomized rats

Esse estudo objetivou avaliar o efeito da ooforectomia sob os parâmetros histomorfométricos dos cardiomiócitos e quantificação de colágeno em ratas Wistar. Vinte ratas foram utilizadas e separadas em dois grupos: GI - ooforectomizada e GII - sham-ooforectomizada. Após a recuperação anestésica os animais foram acomodados em gaiolas e separados nas condições de ciclo claro/escuro 12/12h por um período de 6 meses. Passado o período experimental, os animais foram anestesiados, o coração retirado e mergulhado em formaldeído a 10%. Os fragmentos dos ventrículos foram submetidos ao processamento histológico e corados com hematoxilina e eosina. As análises histomorfométricas (área celular e área e volume nuclear) foram realizadas pelo microscópio de luz e software ImageJ versão 1.44. Os dados foram submetidos à análise ANOVA e quando significantes, complementados pelo teste t de student (p<0,001). Observou-se uma diminuição significativa das áreas celular e nuclear dos cardiomiócitos do grupo GI quando comparado ao grupo GII, bem como a área ocupada, pelo colágeno, no músculo cardíaco foi maior em GI, quando comparado a GII. Diante disso, conclui-se que as alterações observadas nos cardiomiócitos do grupo GI, sugerem uma maior atividade apoptótica nesse grupo, devido à diminuição dos níveis séricos do estrógeno provocado pela ooforectomia e o aumento da área ocupada pelo colágeno, no grupo ooforectomizado, está associada ao efeito cardioprotetor do estrógeno.

This study aimed to evaluate the effect of oophorectomy on the morphometric variables of cardiomyocytes and quantification collagen in Wistar rats. Twenty rats were used and divided into two groups: GI - ovariectomized and GII - sham-ovariectomized. After recovery from anesthesia the animals were housed in separate cages and under the conditions of light / dark cycle 12/12h for a period of six months. After the experimental period, the animals were anesthetized, the heart removed and immersed in 10% formaldehyde. The fragments of the ventricles were subjected to histological analysis and stained with hematoxylin and eosin. Histomorphometric analysis (cell area and nuclear area and volume) were performed by light microscopy and ImageJ software version 1.44. The data were submitted to ANOVA and when significant, complemented by Student's t test (p<0.001). There was a significant decrease in cellular and nuclear areas of the GI cardiomyocytes compared to GII and the area occupied by collagen was greater in cardiac muscle GI, when compared to GII. Therefore, it is concluded that the changes observed in the GI group cardiomyocytes, suggest a higher apoptotic activity in this group, due to decreased serum estrogen levels caused by ovariectomy and increased area occupied by collagen in oophorectomized group is associated the cardioprotective effect of estrogen.

Effect of 1a,25(OH)2 D3 on circadian clock gene expression in cardiac myocytes / 中华实用儿科临床杂志

Objective To explore the effect of 1a,25(OH)2 D3 on circadian clock gene expressions in cardiac myocytes.Methods Cultured cardiac myocytes isolated from 7 -day -old Sprague -Dawley(SD)rats were identified by immunofluorescence.The medium including 1a,25 (OH)2 D3 (final concentrations were 0 nmol/L,1 nmol/L, 10 nmol/L,50 nmol/L and 100 nmol/L)were added to primary myocardial cells to culture for 2 h and then total RNA was extracted.Real -time polymerase chain reaction (RT -PCR)was applied to analyze myocardial cells circadian clock gene (Bmal1,Per2,Rev -erba)transcript levels to determine optimum concentration of 1a,25(OH)2 D3 .Then, the primary myocardial cells cultured for 72 h were divided into 3 groups:the control group was of serum -free culture medium;serum shock group was of DMEMcontaining 50%volume fraction of horse serum cultured 2 h;1a,25(OH)2 D3 treatment group receiving 1a,25 (OH)2 D3 at optimal concentration cultured 2 h.The cells were collected at 7 time points (0 h,4 h,8 h,12 h,16 h,20 h,24 h)and then total RNA was extracted.RT -PCR was applied to analyze circa-dian clock gene (Bmal1,Per2,Rev -erba)transcript levels in the myocardial cells.Results In the presence of 50 nmol/L 1 a,25(OH)2 D3 ,the Bmal1 mRNA expression showed the highest level,but the Per2 and Rev -erba mRNA expression levels were minimum.Compared with the control group,both 1a,25 (OH)2 D3 treatment group and serum shock group caused day -cycle rhythmic oscillation in circadian clock genes(Bmal1,Per2,Rev -erba)in the cardiac myocytes.And the expressions pattern of Bmal1 and Per2 genes were in the opposite phase.While Bmal1 gene expres-sion appeared at peak at 12 h,Per2 gene expression appeared in a trough.Expression of Rev -erba gene trend began to rise at 8 h,and the highest expression level appeared at 12 -16 h.Conclusions 1a,25(OH)2 D3 can affect Bmal1, Per2 and Rev -erba mRNA expressions of circadian clock genes in the cardiac myocytes.

Influence of microRNAs on cordiomyocyte viability in myocardial infarction and its therapeutic potential: Research progress / 第二军医大学学报

MicroRNAs (miRs), initially discovered in eukaryotes, are endogenous small noncoding RNAs that regulate gene expression. Myocardial infarction is a common cardiovascular event resulting in cardiac remodeling and subsequent chronic heart failure. A number of miRs have been reported to regulate important pathophysiological processes of myocardial infarction. They have multiple effects on the survival and proliferation of cardiomyocytes, which is of great significance to myocardial infarction and other ischemic heart diseases. In this review we introduced the general knowledge of myocardial infarction and miRs, and described several miRs which are crucial for survival and proliferation of cardiomyocytes. We also discussed the therapeutic potential and limitations of miRs in future treatment of myocardial infarction.

Preparation of PCM modified liposome and evaluation of its myocardium targeting efficiency / 第二军医大学学报

Objective To prepare PCM modified liposome (PCM-LIP) containing enhanced green fluorescent protein expression plasmid (pEGFP) and to evaluate its myocardial targeting ability. Methods Liposome was prepared by film-ultrasonic, with PCM used as ligand and DOTAP as cationic lipid material. PCM-LIP containing pEGFP was prepared by incubating liposome with pEGFP at room temperature. The connecting method of PCM was optimized and the connection rate of PCM was determined. The characteristics of liposomes including encapsulation ability, morphology, particle size, zeta potential and stability in phosphate buffer solution (PBS) were observed. The transfection efficiency of liposomes into H9c2 cells was evaluated by inverted fluorescence microscopy and flow cytometry, so as to characterize their myocardial targeting ability and to determine the optimum dosage of PCM. Results PCM-LIP was prepared by insertion method and the amount of PCM accounted for 3% of the lipid. After incubation with pEGFP, PCM-LIP was spherical in shape, with the particle size being (261. 9±2. 2) nm, zeta potential being (-5. 0±0. 6) mV, and PCM-LIP was stable in PBS at -4℃ for 30 d. The transfection efficiency of PCM-LIP was significantly higher than that of unmodified liposome (P<0. 05). Conclusion PCM can improve the transfection efficiency of liposome into cardiomyocytes and PCM-LIP shows a satisfactory myocardial targeting ability.

Protective function of tocilizumab in human cardiac myocytes ischemia reperfusion injury

Objective:To investigate the protective function of tocilizumab in human cardiac myocytes ischemia-reperfusion injury.Methods:The human cardiac myocytes were treated by tocilizumab with different concentrations(1.0 mg/mL, 3.0 mg/mL, 5.0 mg/mL) for 24 h,then cells were cultured in ischemia environment for 24 h and reperfusion environment for 1 h. The MTT and flow cytometry were used to detect the proliferation and apoptosis of human cardiac myocytes, respectively. The mRNA and protein expressions of Bcl-2 and Bax were measured by qRT-PCR and western blot, respectively.Results:Compared to the negative group, pretreated by tocilizumab could significantly enhance the proliferation viability and suppress apoptosis of human cardiac myocytes after suffering ischemia reperfusion injury(P<0.05).The expression of Bcl-2 in tocilizumab treated group were higher thanNC group(P<0.05), while theBax expression were lower(P<0.05).Conclusions:Tocilizumab could significantly inhibit apoptosis and keep the proliferation viability of human cardiac myocytes after suffering ischemia reperfusion injury. Tocilizumab may obtain a widely application in the protection of ischemia reperfusion injury.

Isoflurane attenuates human cardiacmyocytes anoxia/reoxygenation injury / 基础医学与临床

Objective_To explore the effect and the mechanism of isoflurane on human cardiac myocytes ( HCM) injury induced by anoxia/reoxygenation ( AR) .Methods_HCM cells were divided into control group ( con) , an-oxia/reoxygenation group (AR) and isoflurane (0.5%, 1%, 1.5%and 2%) treatment group (n=6).Cell via-bility, LDH activity, apoptosis and the expression level of Anoxia inducible factor-1α( HIF-1α) were detected using CCK-8 assay, LDH activity assay kit, Annexin V-FITC/PI staining, PCR and western blot, respectively. Results_Compared with the con group, cell viability decreased, LDH activity and apoptosis cells increased in AR group.Isoflurane can significantly relieve the decrease of cell viability, the increase of LDH activity and apoptosis cells, and the down-regulation of the mRNA and protein expression level of HIF-1αinduced by AR ( P<0.05 ) . Compared with AR group, the mRNA and protein expression level of HIF-1αin siRNA transfected group signifi-cantly decreased (P<0.05).2%isoflurane significantly relieve the increase of cell viability, the decrease of LDH activity and apoptotic cells induced by HIF-siRNA in AR injuried HCM cells(P<0.05).Conclusions_Isoflurane can protect HCM cells from AR injury partly through up-regulate the expression of HIF-1α.

Protective function of tocilizumab in human cardiac myocytes ischemia reperfusion injury

OBJECTIVE@#To investigate the protective function of tocilizumab in human cardiac myocytes ischemia-reperfusion injury.@*METHODS@#The human cardiac myocytes were treated by tocilizumab with different concentrations(1.0 mg/mL, 3.0 mg/mL, 5.0 mg/mL) for 24 h, then cells were cultured in ischemia environment for 24 h and reperfusion environment for 1 h. The MTT and flow cytometry were used to detect the proliferation and apoptosis of human cardiac myocytes, respectively. The mRNA and protein expressions of Bcl-2 and Bax were measured by qRT-PCR and western blot, respectively.@*RESULTS@#Compared to the negative group, pretreated by tocilizumab could significantly enhance the proliferation viability and suppress apoptosis of human cardiac myocytes after suffering ischemia reperfusion injury (P<0.05). The expression of Bcl-2 in tocilizumab treated group were higher than NC group (P<0.05), while the Bax expression were lower (P<0.05).@*CONCLUSIONS@#Tocilizumab could significantly inhibit apoptosis and keep the proliferation viability of human cardiac myocytes after suffering ischemia reperfusion injury. Tocilizumab may obtain a widely application in the protection of ischemia reperfusion injury.

Protective function of tocilizumab in human cardiac myocytes ischemia reperfusion injury

Objective: To investigate the protective function of tocilizumab in human cardiac myocytes ischemia-reperfusion injury. Methods: The human cardiac myocytes were treated by tocilizumab with different concentrations(1.0 mg/mL, 3.0 mg/mL, 5.0 mg/mL) for 24 h, then cells were cultured in ischemia environment for 24 h and reperfusion environment for 1 h. The MTT and flow cytometry were used to detect the proliferation and apoptosis of human cardiac myocytes, respectively. The mRNA and protein expressions of Bcl-2 and Bax were measured by qRT-PCR and western blot, respectively. Results: Compared to the negative group, pretreated by tocilizumab could significantly enhance the proliferation viability and suppress apoptosis of human cardiac myocytes after suffering ischemia reperfusion injury (. P<0.05). The expression of Bcl-2 in tocilizumab treated group were higher than NC group (. P<0.05), while the Bax expression were lower (. P<0.05). Conclusions: Tocilizumab could significantly inhibit apoptosis and keep the proliferation viability of human cardiac myocytes after suffering ischemia reperfusion injury. Tocilizumab may obtain a widely application in the protection of ischemia reperfusion injury.

Regulatory effects of long non-coding RNA HIF1A-AS1 on ischemic myocardial reperfusion injury in rats / 第二军医大学学报

Objective To study the regulatory effects of long non-coding RNA HIF1A-AS1 on the myocardial ischemia reperfusion (I/R) injury and the related mechanism. Methods Myocardial I/R injury model was established with SD rats, and hypoxia reoxygenation (H/R) model was established with rat cardiac myocytes. si-HIF1A-AS1 was used to inhibit HIF1A-AS1 expression in the cardiac myoctyes. Then the mRNA expression of HIF1A-AS1 was detected by real-time PCR, the growth vitality of cardiac myocytes was investigated by MTT assay, the concentration of lactate dehydrogenase (LDH) in the culture media was detected by ELISA, and the autophagy-associated protein Beclin-1 expression was observed by Western blotting analysis. Results HIF1A-AS1 expression was increased in cardiac muscle of rat I/R model and rat cardiac myocytes of H/R model. Inhibition of HIF1A-AS1 by siRNA protected the cardiomyocytes against H/R injuries, reversing the decreased growth vitality of cardiac myoctyes, increased LDH level in the culture media, and increased expression of autophagy-related protein Beclin-1 induced by H/R stimulation. Conclusion Inhibition of long non coding RNA HIF1A AS1 might play a protective role in I/R injury of cardiac myoctyes by inhibiting the excessive autophagy of cardiomyocytes.