High glucose induces myocardial cell injury through increasing reactive oxygen species production

Objective: To study the injury effect and molecular mechanism of high glucose on myocardial cells. Methods: Myocardial cells H9 c2 were cultured and divided into the control group treated with DMEM containing 5.5 mmol/L glucose, the high glucose group treated with DMEM containing 35 mmol/L glucose, and the N-acetylcysteine(NAC) group pre-treated with 1000μmol/L NAC and treated with DMEM containing 1000 μmol/L NAC and 35 mmol/L glucose.The production of ROS and the expression of mitochondria pathway apoptosis molecules in cells as well as the contents of collagen and collagen metabolism molecules were measured.Results: After 8 h, 16 h and 24 h of treatment, ROS RFU as well as Bax, CytC, Caspase-3 and Caspase-9 protein expression in cells and Col-I, Col-Ⅲ, PINP and PⅢNP protein levels in culture medium of high glucose group were higher than those of control group, Bcl-2 protein expression were lower than those of control group, but CTX-Ⅰ protein levels in culture medium were not significantly different from those of control group; after 24 h of treatment, Bax, CytC,Caspase-3 and Caspase-9 protein expression in cells as well as Col-Ⅰ, Col-Ⅲ, PINP and PIIINP protein levels in culture medium of NAC group were lower than those of high glucose group whereas Bcl-2 protein expression was higher than that of high glucose group. Conclusions:High glucose can induce myocardial cell apoptosis, increase collagen synthesis and accelerate interstitial fibrosis by increasing the production of reactive oxygen species.

Magnetic resonance evaluation of transplanted mesenchymal stem cells after myocardial infarction in swine

Objectives To trace and evaluate intracoronary transplanted mesenchymal stem cells(MSCs) labeled with superparamagnetic iron oxide(SPIO) by using magnetic resonance imaging(MRI) in a swine model of myocardial infarction (MI).Methods MSCs were transfected with a lentiviral vector carrying the gene encoding green fluorescent protein (GFP) and labeled in vitro with SPIO.Two weeks after MI, swine were randomized to intracoronary transplantation of dual -labeled MSCs(n = 10),MSCs-GFP(n = 10) and saline(n = 5).MRI examination was performed with a 1.5T clinical scanner at 24 hours,3 weeks and 8 weeks after cells transplantation. Signal intensity(SI) changes,cardiac function and MI size were measured using MRI.Correlation between MR findings and histomorphologic findings was also investigated. Results The labeling efficiency at a combination of 25μg Fe/ml SPIO and 0.8 pi/ml Lipofectamine 2000 reached 100%.SPIO labeling did not affect GFP fluorescence and dual-labeling did not affect cell proliferation(P】0.05). Multipotentiality was not affected especially for cardiomyocyte-like cells differentiation.Cardiac cell marker of a-MHC and actinin were positively expressed by immunofluorescence staining after induction.SI on T2 * WI decreased substantial- ly in the interventricular septum 24 hours after injection of MSCs.The intensity of hypo-intense signals appeared to increase throughout the later time points.Changes in SI at 24 hours,3 weeks and 8 weeks were 52.98%±10.74%,21.53%±5.40%and 6.23%±2.01%,respectively(P【0.01).DE-MRI demonstrated both dual-labeled MSCSs and MSCs-GFP could dramatically reduce the size of MI and improve cardiac function. Histological data revealed that prussian blue stain-positive cells were found mainly in the border zone which also showed green fluorescence but negative for macrophage marker(CD68).Gross pathologic examination revealed that engrafted MSCs dramatically reduce the extent of necrotic myocardium and promote the regeneration of new,contractile myocardium along the subendocardial surface of the MI. Conclusions MSCs could be efficiently and safely labeled with SPIO and GFP,and could be detected reproducibly and noninvasively in vivo using cardiac MRI.Intracoronary transplantation of dual-labeled MSCs could increase cardiac function and reduce the size of MI.

When is The Best Time of Stem Cell Transplantation for Treating Acute Myocardial Infarction──A Brief Meta-analysis of Current Clinic Trials

The best time of stem cells transplantation for treating acute myocardial infarction (AMI) is still to be followed with interest and a focus issue for clinical cardiologist. A brief meta-analysis of clinical trials about timing-window and therapeutic effects of stem cell transplantation for treating AMI will be made out in this article.

Experimental study of miRNA-210 modified MSCs in the treatment of myocardial ischemia-reperfusion injury in rats

Objective:To investigate the therapeutic effect of microRNA210(miRNA-210)modified mesenchymal stem cells(MSCs)on myocardial ischemia-reperfusion injury(MIRI)model rats.Methods:One SD rat was sacrificed,and the lower extremity tibia and femur were isolated.MSCs were cultured by whole bone marrow adherence method to construct miRNA-210 modified MSCs.40 SD rats were divided into the sham operation group,model group,MSCs group,and miRNA-210+MSCs group,with 10 rats in each group.The left anterior descending coronary artery was ligated to prepare a model of myocardial ischemia and reperfusion.After successful modeling,50μl of MSCs suspension was injected into the tail vein of the MSCs group,and 50μl of miRNA-210 modified MSCs suspension was injected into the tail vein of the miRNA-210+MSCs group.The sham operation group and the model group were injected with the same amount of normal saline.On the 10th day after modeling,the area of myocardial infarction,morphological changes of myocardial tissue,myocardial cell apoptosis rate,and miRNA-210 expression were compared in each group.Results:The area of myocardial infarction and the rate of myocardial cell apoptosis in the model group were significantly higher than those in the sham operation group(<0.05);The area of myocardial infarction and the rate of myocardial cell apoptosis in the MSCs group were significantly lower than those in the sham operation group(P<0.05);The area of myocardial infarction and the rate of myocardial cell apoptosis in the miRNA-210+MSCs group were significantly higher than those in the MSCs group(P<0.05);The area of myocardial infarction and the rate of myocardial cell apoptosis in the miRNA-210+MSCs group were significantly lower than those in the sham operation group(P<0.05).The expression level of miRNA-210 in the myocardial tissue of the model group was significantly higher than that in the sham operation group(P<0.05);There were no significantly different in the expression level of miRNA-210 in the myocardial tissue between the MSCs group and model group(P>0.05);The expression level of miRNA-210 in the myocardial tissue of MSCs group was significantly higher than in the MSCs group,model group and sham operation group(P<0.05).HE staining showed that the miRNA-210+MSCs group had normal morphology of myocardial tissues,more uniform cytoplasmic staining,and arranged neatly myocardial fibers.The inflammatory cell infiltration and interstitial edema of the miRNA-210+MSCs group were significantly improved compared with the model group and MSCs group.Conclusion:MiRNA-210 modified MSCs can inhibit myocardial cell apoptosis in myocardial ischemia-reperfusion injury model rats,reduce the area of myocardial infarction,and improve pathological damage of myocardial tissue in rats,which has a certain therapeutic effect on myocardial ischemia-reperfusion injury.

Research progress of Hippo kinase cascade and cardiovascular disease

The occurrence of cardiovascular events is one of the important causes of death and disability in the nation.The ischemia and hypoxia of myocardial cells caused by coronary atherosclerosis,intravascular stenosis or myocardial infarction leads to cell damage,necrosis and apoptosis,leading to Myocardial fibrosis affects cardiac function and the quality of life of patients.Reducing myocardial cell apoptosis,inhibiting myocardial fibrosis and promoting myocardial cell regeneration are of great significance for maintaining the normal shape and function of the heart.With the progress of research,scientists have discovered that the Hippo pathway plays an important role in the repair and regeneration of myocardial cells.This article reviews the regulatory effects and mechanisms of the various factors in the Hioop signaling pathway in the repair and regeneration of cardiomyocytes.

左卡尼汀对波动性高糖处理大鼠心肌细胞脂联素受体表达影响的实验研究

目的探讨左卡尼汀（L-carnitine,L-CN）对波动性高糖处理大鼠心肌细胞（rat myocardial cell,RMC）脂联素受体（AdipoR1和AdipoR2）表达的影响。方法将RMC在高糖（20 mmol/L）、波动性高糖培养液（5.5 mmol/L和20 mmol/L每隔8 h轮换1次）中培养5 d后,随机分为正常组、高糖组、波动性高糖组、波动性高糖＋L-CN处理组（102、2.5×102、5×102、103、104、105及106μΜ）。运用细胞增殖试验（CCK8法）检测细胞存活率,依据细胞增殖试验的结果,将分组调整为阴性对照（正常组）、阳性对照（波动性高糖组）、波动性高糖组＋L-CN处理组（102、2.5×102、5×102、103及104μΜ）,应用实时荧光定量PCR方法检测AdipoR mRNA表达的改变。结果与正常组相比,高糖组心肌细胞OD值降低不明显;波动性高糖组心肌细胞OD值减小,与正常组比较差异有显著性（P〈0.05）。提示波动性高糖组对细胞的损害作用明显高于单纯高糖组。L-CN（5×102μΜ）处理组较波动性高糖组OD值增加,差异有显著性（P〈0.05）;L-CN（2.5×102、103及104μΜ）处理组较波动性高糖组OD值增加,差异无显著性（P〉0.05）;L-CN（105μΜ和106μΜ）处理组较波动性高糖组OD值下降,提示左卡尼汀的作用浓度在102~104μΜ之间。L-CN处理后RMCs AdipoR1 mRNA、AdipoR2mRNA均明显增高（P〈0.01）,当L-CN工作浓度在5×102μΜ时,AdipoR表达增加更明显。结论波动性高糖与单纯高糖相比对细胞的损害作用更强,左卡尼汀可在一定程度上降低波动性高糖引起的细胞损害作用,且药物有效浓度在102~104μΜ之间。在波动性高糖环境中,RMC AdipoR mRNA表达下调（P〈0.01）,左卡尼汀能明显上调波动性高糖处理后大鼠心肌细胞AdipoR mRNA表达（P〈0.01）,从而为L-CN类药物更广泛应用于糖尿病心肌病变提供了新思路和新证据。

上海市甲肝疫情分析及防制对策专家座谈会纪要

上海市甲肝疫情分析及防制对策专家座谈会纪要时间：１９９３年１１月９日地点：上海市预防医学会会议室出席对象：（以姓氏笔划为序）王希孟王耆煌朱志强孙家明巫善明周廷魁柳向光闻玉梅袁惠章徐志一黄雨舜康来仪王道民姚光弼胡善联（因故请假）上海市甲型病毒性肝炎（简...

黄芪、人参增强人心肌细胞抗病毒感染的实验研究——降低对病毒敏感性及诱生干扰素作用

在培养的人心肌细胞上研究了黄芪、人参抗Cox B-3及Echo-19病毒的作用及诱生干扰素的效应,结果表明两种药物分别作用于人心肌细胞48小时及感染病毒的心肌细胞在含药物的营养液中培养均可降低细胞对两种病毒感染的敏感性,此作用与药物诱导心肌细胞产生IFN有关。

Xuefu Zhuyu Oral Liquid (血府逐瘀口服液) Prevents Apoptosis of Ischemic Myocardium Cells in Rats by Regulating SIRT1 and Its Pathway-Related Genes

Objective:To observe the changes of ischemic myocardial cells apoptosis in rats following intervention with Xuefu Zhuyu Oral Liquid(血府逐瘀口服液,XFZY),as well as changes of protein expression of silent information regulator 1(SIRT1)and SIRT1 pathway-related genes.Methods:H9c2 rat myocardial cells were divided into 6 groups:control group,oxygen glucose deprivation(OGD)group,SIRT1 siRNA group,OGD+SIRT1 siRNA group,OGD+XFZY group,and OGD+SIRT1 siRNA+XFZY group.Quantitative fluorescent polymerase chain reaction(PCR)and Western blot were used to detect the concentration variations of SIRT1 and its pathway-related genes and corresponding protein expression after XFZY intervention and SIRT1 transfection.Results:Compared with the control group,the mRNA and protein expressions of SIRT1 were decreased obviously,while the mRNA and protein levels of P53,forkhead box protein O1(FoxO1),FoxO3,FoxO4 and nuclear factor kappa B(NF-κB)were increased in the OGD group,SIRT1 siRNA group,and OGD+SIRT1 siRNA group(P<0.01).Compared with the OGD group and OGD+SIRT1 siRNA group,the treatment of XFZY inhibited the decline in SIRT1 mRNA and protein expressions(P<0.01),and down-regulated the mRNA and protein levels of P53,FoxO1,FoxO3,FoxO4 and NF-κB,respectively(P<0.05 or P<0.01).Conclusion:XFZY could prevent myocardial cells apoptosis probably by increasing the mRNA and protein expressions of SIRT1 and inhibiting the mRNA and protein expressions of P53,NF-κB,FoxO1,FoxO3 and FoxO4.

Anti-oxidation of Tanshinone Ⅱ_A and Prohibitin on Cardiomyocytes

Objective To investigate the anti-apoptotic mechanism of tanshinone ⅡA and the function of prohibitin (PHB) on myocardial cells apoptosis induced by hydrogen peroxide (H2O2). Methods Myocardial cells were primary cultured neonate rat were cultured in medium with 200 μmol/L H2O2, and the medium was supplemented with tanshinone ⅡA (1 × 10-4 mol/L) in advance for 24 h. PHB in myocardial cells was knocked down by RNA interference, and the expression level of PHB was determined by Western blotting analysis. Flow cytometric analysis was used to detect apoptosis rate, intracellular calcium concentration ([Ca2+]i), and mitochondrial membrane potential (MMP). Results H2O2-mediated cell apoptosis resulted in activation of PHB, increasing of [Ca2+]i, and decreasing of MMP. Tanshinone ⅡA profoundly inhibited myocardial cell apoptosis induced by H2O2, decreased [Ca2+]i, and increased MMP. Specific silence of PHB by siRNA down-regulated the expression level of PHB, increased apoptosis rate and [Ca2+]i, and decreased MMP. Conclusion The results demonstrate that tanshinone ⅡA could attenuate apoptosis induced by H2O2, and the activation of PHB induced by H2O2 is the major regulatory pathway of cyto-protective gene expression against oxidative stress.