AduoLa Fuzhenglin Down-regulates Microwave-induced Expression of β_1-adrenergic Receptor and Muscarinic Type 2 Acetylcholine Receptor in Myocardial Cells of Rats

This paper is aimed to study the effect of ADL on expression of ~z-AR and Mz-AchR in myocardial cells of rats exposed to microwave radiation. Immunohistochemistry, Western blot and image analysis were used to detect the expression of ~I-AR and Mz-AchR in myocardial cells at 7 and 14 d after microwave exposure. The results show that the expression level was higher in microwave exposure group and 0.75 g/（kg.d） ADL group than in sham operation group and significantly lower in 1.5 and 3.0 g/（kg.d） ADL groups than in microwave group. So we have a conclusion that the expression of I^z-AR and Mz-AchR is down-regulated in myocardial cells of rats exposed to microwave radiation. ADL can protect rats against microwave-induced heart tissue injury.

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.

Manganese enhances the expression of the manganese superoxide dismutase in cultured primary chick embryonic myocardial cells

In the present study, the effect of manganese（Mn） on antioxidant status and the expression of the manganese superoxide dismutase（MnSOD） gene in cultured primary myocardial cells collected from the chick embryos was investigated. The hypothesis that Mn supplementation would enhance the expression of MnSOD in cultured primary myocardial cells of chick embryos was tested. Eggs collected from Mn-depleted Arbor Acres laying breeder hens were incubated for 10 days and then myocardial cells were isolated and cultivated for 8 days. The embryonic myocardial cells on day 6 were treated with Mn in the cell culture medium at different time points when the proportion of cells showing spontaneous contraction was over 95% after the 3-day primary culture. A completely randomized design involving a 3 Mn levels（0, 0.5 and 1.0 mmol L^（-1））×3 incubation time points（12, 24 and 48 h） factorial arrangement of treatments（n=6） was used in the current experiment. The results showed that MnSOD activity and m RNA expression level were induced by Mn and increased with incubation time, which supported the hypothesis that Mn would enhance the expression of the MnSOD gene, and thus might protect myocardial cells from oxidative stress during the chick embryonic development.

Polysaccharide extracts of Cirsium japonicum protect rat H9c2 myocardial cells from oxidative stress induced by hydrogen peroxide

Daji （Cirsium japonicum） has been applied against gastric disorders, lung diseases, and cardiovascular problems in thetraditional Chinese medicinal system. The present study was to investigate the protective effects of Daji （Cirsiumjaponicum） polysaccharide extracts （CJP） against hydrogen peroxide （H2O2） shock in rat H9c2 myocardial cells. First,CJP was isolated by hot water extraction and ethanol precipitation; it was then characterized by high performance liquidchromatography and infrared spectrum analysis. Rat H9c2 cells were subjected to H2O2 treatment to establish a cellinjury model. The 3- （4,5- dimethylthiazol- 2-yl）-2,5- diphenyltetrazolium bromide assay showed that CJP pretreatmentsignificantly ameliorated the H2O2 injury in a dose-dependent manner. Furthermore, the cell apoptosis induced by H2O2was markedly inhibited by CJP pretreatment, whereas the cleavage level of caspase-3, -8, and -9 was reduced. Inaddition, the p38 mitogen-activated protein kinase pathway might be involved in the protective effect of CJP onmyocardial cells. Therefore, we conclude that polysaccharide extracts of Daji （Cirsium japonicum） protect rat H9c2myocardial cells from oxidative stress induced by H2O2.

Expression of Porcine Circovirus Type 2 ORF2 Gene in Myocardial Cells of Detached Cherry Valley Duck

The objective of this study was to construct the recombinant eukaryotic expression plasmid of ORF2 gene harboring enhanced green fluorescent protein （EGFP） report gene. ORF2 gene of porcine circovirus type 2 cloned by PCR was ligated to the expression vector pEGFP-N1, which contains enhanced green fluorescent protein （EGFP） report gene, the recombinant eukaryotic expression plasmid pEGFP-N1-ORF2 was constructed successfully and was transfected into pre- pared duck myocardial cells （DMCs） by lipofectin. According to the result, the fluorescence expression was directly detected with fluorescence microscope, and the expression of ORF2 were analyzed by RT-PCR and indirect immunofluorescence assay （IFA） respectively. About 48 h after transfection, green fluorescent can be observed on transfected cells ： T-PCR and IFA were positive. This indicated that ORF2 gene of PCV2 was expressed efficiently in transfected duck myocardial cells.

Glycine receptors contribute to cytoprotection of glycine in myocardial cells

Background The classic glycine receptor （GlyR） in the central nervous system is a ligand-gated membrane-spanning ion channel. Recent studies have provided evidence for the existence of GlyR in endothelial cells, renal proximal tubular cells and most leukocytes. In contrast, no evidence for GlyR in myocardial cells has been found so far. Our recent researches have showed that glycine could protect myocardial cells from the damage induced by lipopolysaccharide （LPS）. Further studies suggest that myocardial cells could contain GlyR or binding site of glycine. Methods In isolated rat heart damaged by LPS, the myocardial monophasic action potential （MAP）, the heart rate （HR） the myocardial tension and the activities of lactate dehydrogenase （LDH） from the coronary effluent were determined. The concentration of intracellular free calcium （[Ca^2＋]i） was measured in cardiomyocytes injured by LPS and by hypoxia/reoxygenation （H/R）, which excludes the possibility that reduced calcium influx because of LPS neutralized by glycine. Immunohistochemistry was used to detect the GlyR in myocardial tissue. GlyR and its subunit in the purified cultured cardiomyocytes were identified by Western blotting. Results Although significant improvement in the MAP/MAPD20, HR, and reduction in LDH release were observed in glycine ＋ LPS hearts, myocardial tension did not recover. Further studies demonstrated that glycine could prevent rat mycordial cells from LPS and hypoxia/reoxygenation injury （no endotoxin） by attenuating calcium influx. Immunohistochemistry exhibited a positive green-fluorescence signaling along the cardiac muscle fibers. Western blotting shows that the purified cultured cardiomyocytes express GlyR β subunit, but GlyR α1 subunit could not be detected. Conclusions The results suggest that glycine receptor is expressed in cardiomyocytes and participates in cytoprotection from LPS and hypoxia/reoxygenation injury. Glycine could directly activate GlyR on the cardiomyocytes and prevent calcium influx into the cardiomyocytes.

Study of Anti-Myocardial Cell Oxidative Stress Action and Effect of Tanshinone IIA on Prohibitin Expression

Objective:To investigate the protective action of tanshinone IIA (TSN) on myocardial apoptosis induced by hydrogen peroxide (H2O2) and its effect on prohibitin (PHB) expression to probe the role of PHB in the oxidation stress of myocardial cells. Methods: Primary cultured neonate rat myocardial cells were cultured with TSN (1×10-4 mol/L) for 24 hours, and then the medium was supplemented with 200 μmol/L hydrogen peroxide for 2 h to initiate myocardial cell oxidative stress injury. PHB in myocardial cells was knocked down by small interfering RNA (siRNA), and the expression level of PHB was determined by western blot analysis. Flow cytometry was used to detect the apoptosis rate, intracellular calcium ion concentration ([Ca2+]i) and mitochondrial membrane potential (MMP). Results: The PHB expression, [Ca2+]i and the apoptotic rate significantly increased, and the MMP significantly decreased in the oxidative stress group compared with the control. The PHB expression, apoptosis rate and [Ca2+]i decreased, and MMP increased significantly in the TSN group compared with the oxidative stress group. Compared with the siRNA negative control group, the PHB expression level in myocardial cells was down-regulated, and the apoptosis rate and [Ca2+]i increased, and MMP decreased significantly in the siRNA group. Conclusion: TSN can reduce PHB expression in oxidative stress-injured myocardial cells hence protecting the myocardial cells.

Effect of Sodium Tanshinone ⅡA Sulfonate on Phosphorylation of Extracellular Signal-regulated Kinasel/2 in Angiotensin Ⅱ-induced Hypertrophy of Myocardial Cells

Objective： To observe the effects of sodium tanshinone ⅡA sulfonate （STS） on angiotensin Ⅱ （Ang Ⅱ）-induced hypertrophy of myocardial cells through the expression of phosphorylated extracellular signal-regulated kinase （p-ERK1/2）. Methods： In the primary culture of neonatal rat myocardial cells, the total protein content in myocardial cells was determined by coomassie brilliant blue and the protein synthesis rate was measured by [3H]-Leucine incorporation as indexes for hypertrophy of myocardial cells. The expression of p-ERK1/2 was determined using Western blot and immunofluorescence labeling. Results： （1） The total protein and protein synthesis rate increased significantly in contrast to the control group after the myocardial cells were stimulated by Ang Ⅱ （1 μ mol/L） for 24 h; STS markedly inhibited the increment of the total protein level induced by Ang Ⅱ and the syntheses of protein. （2） After pretreatment of myocardial cells with Ang Ⅱ （1 μmol/L） for 5 min, the p-ERK1/2 protein expression was increased, with the most obvious effect shown at about 10 min; pretreatment of myocardial cells with STS at different doses （2, 10, 50μmol/L） for 30 min resulted in obvious inhibition of the expression of p-ERK1/2 stimulated by Ang Ⅱ in a dose-dependent manner. （3） After the myocardial cells were stimulated by AngⅡ （1 μ mol/L）, the immunofluorescence of ERK1/2 rapidly appeared in the nucleus. The activation and translocation process of ERK1/2 induced by Ang Ⅱ was blocked distinctly by STS. （Conclusion： STS inhibited the myocardial cell hypertrophy induced by Ang Ⅱ, and the mechanism may be associated with the inhibition of p-ERK1/2 expression.

Protective Effect of Thrombopoietin on Myocardial Cell in Vitro

Objectives To investigate the protective effect of thrombopoietin (TPO) on myocardial cells in vitro. Methods H9C2 cell line was maintained in Iscove’s modified Dulbecco’s medium (IMDM) supplemented with 10% calf serum. Beating cells from heart ventricles of neonatal heart were cultured at an in vitro system. Apoptosis of the cell line above was induced by treatment of doxorubicin (DOX) and was blocked by TPO. Cell survival rate of H9C2 cell was measured by the MTT assay. Changes of beating rate of neonatal myocardial cells were captured by digital camera and beating rate was calculated. Flow cytometry was employed to study anti-apoptotic effect of TPO by staining JC-1 protein to H9C2 cell. Results MTT assay demonstrated that doxorubicin reduced cell survival rate by 73.8%±1.1%, 50 ng·mL-1 and 100 ng·mL-1 TPO increased cell survival rate by 84.6%±3.6% (P<0.05), 86%±4% (P<0.01) at a dose-dependent manner. Beating rate of primary neonatal myocardial cells also decreased to 15%±8% at 48 h, 100 ng·mL-1 TPO improved beating rate to 48%±11% (P<0.01). TPO decreased apoptotic rate from 19%±9% to 11%±6% (P<0.05). Conclusions TPO has protective effect on myocardial cells in vitro. Anti-apoptosis is one of the mechanisms by which TPO protects injured heart.

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.

VEGF-expressing Bone Marrow Mesenchymal Stem Cells Transplantation Improved Heart Function of Myocardial Infarct Rabbits

Objectives To treat myocardial infarction with MSCs transplantation combined with VEGF gene therapy in rabbits and to study its mechanisms. Methods Forty-eight rabbits were randomly divided into MI group （n=12）, MSCs group （n=12）, VEGF group （n=12）, MSCs＋VEGF group （M＋V group, n=12）. Rabbit myocardial infarction models were founded by the ligation of left anterior descending artery. 107 MSCs were injected into the infarct-zone in four sites 2 weeks later in MSCs and M＋ V group, phVEGF gene were injected in infarct-zone in VEGF group and MSCs transfected with phVEGF gene were injected in M＋V group. Heart function including LVEDP, LVSP, LVDP, -dp/dtmax, ＋dp/dtmax, were measured in vivo. The hearts were harvested at 4 weeks after transplantation and sectioned for HE stain, immunohistochemical stain of BrdU and VIII factor antigen. Results The left ventricular hemodynamics parameters showed that heart function were improved more in M＋V group than MSCs group, MI group and VEGF group. The numbers of BrdU positive cells in M＋ V group（61±8）were more than in MSCs group （44±8, P 〈 0.01）. The numbers of vessels in infarcted zone were more in M＋V group （49±8） than in MSCs group （33±6, P 〈 0.01）,VEGF group（30±8, P 〈 0.01）and Mlgroup （18±4, P〈0.01）. Conclusions VEGF-expressing MSCs transplantation could improve heart function after myocardial infarction, and they were more effective than sole MSCs transplantation. Keeping more MSCs survival and ameliorating the blood supply of infarct-zone might be involved in the mechanisms.

Hypoxia Enhances the Therapeutic Potential of Superparamagnetic Iron Oxide-labeled Adipose-derived Stem Cells for Myocardial Infarction

Adipose-derived stem cells（ASCs） induce therapeutic angiogenesis due to pro-angiogenic cytokines secretion. Superparamagnetic iron oxide（SPIO） nanoparticles are critical for magnetic resonance（MR） tracking of implanted cells. Hypoxia is a powerful stimulus for angiogenic activity of ASCs. In this study, we investigated whether therapeutic potency could be enhanced by implantation of hypoxia-preconditioned SPIO-labeled ASCs（SPIOASCs） into the infarcted myocardium. ASCs and SPIOASCs were cultured under 2% O_2（hypoxia） or 95% air（normoxia）. Cells were intramyocardially injected into the infarcted myocardium after 48-h culture. We found that hypoxia culture increased the m RNA expression of hypoxia-inducible factor-1 alpha（HIF-1α） and vascular endothelial growth factor（VEGF） in ASCs and SPIOASCs. The VEGF protein in the conditioned medium was significantly higher in hypoxic ASCs and SPIOASCs than in normoxic ASCs and SPIOASCs. The capillary density and left ventricular contractile function in the infarcted myocardium were significantly higher 4 weeks after implantation with hypoxic ASCs and SPIOASCs than with normoxic ASCs and SPIOASCs. Improvement in the capillary density and left ventricle function didn＇t differ between hypoxic ASCs-transplanted rats and hypoxic SPIOASCs-transplanted rats. Hypoxic culture enhanced the angiogenic efficiency of ASCs. It was concluded that implantation of hypoxic ASCs or SPIOASCs promotes therapeutic angiogenesis and cardiac function recovery in the infarcted myocardium. SPIO labeling does not impact the beneficial effect of hypoxic ASCs.

THE IMPROVEMENT OF INFARCTED MYOCARDIAL CONTRACTILE FORCE AFTER AUTOLOGOUS SKELETAL MUSCLE SATELLITE CELL IMPLANTATION

Objective To study the improvement of infarcted myocardial contractile force after autologous skeletal muscle satellite cell implantation via intracoronary arterial perfusion. Methods Skeletal muscle cells were harvested from gluteus max of adult mongrel dogs and the cells were cultured and expanded before being labeled with DAPI (4’, 6-diamidino-2-phenylindone). The labeled cells were then implanted into the acute myocardial infarct site via the ligated left anterior descending (LAD) coronary artery. Specimens were taken at 2nd, 4th, 8th week after myoblast implantation for histologic and contractile force evaluation, respectively. Results The satellite cells with fluorescence had been observed in the infarct site and also in papi- llary muscle with consistent oriented direction of host myocardium. A portion of the implanted cells had differen- tiated into muscle fibers. Two weeks after implantation, the myocardial contractile force showed no significant difference between the cell implant group and control group. At 4 and 8 week, the contractile force in the cell implant group was better than that in control group. Conclusion The skeletal muscle satellite cells, implanted into infarct myocardium by intracoronary arterial perfusion, could disseminate through the entire infarcted zone with myocardial regeneration and improve the contractile function of the infarcted myocardium.

The Safety of Autologous Peripheral Blood Stem Cell Transplantation by Intracoronory Infusion in Patients with Acute Myocardial Infarction

Objectives Bone-marrow stem-cell transplantation has been shown to improve cardiac function in patients with acute myocardial infarction (AMI) , but the safety of intracoronory infusion of autologous peripheral blood stem-cell (PBSCs) in patients with AMI is unknown. For this reason, we observe the feasibility and safety of PBSCs transplantation by intracoronory infusion in such patients. Methods 41 patients with AMI were allocated to receive granulocyte colony-stimulating factor (G- CSF: Filgrastim,300μg) with the dose of 300μg~ 600μg/day to mobilize the stem cell, and the duration of applying G-CSF was 5 days. On the sixth day, PBSCs were separated by Baxter CS 3000 blood cel 1 separator into suspend liquid 57 ml. Then the suspend liquid was infused into the infarct related artery (IRA) by occluding the over the wire balloon and infusing artery through balloon center lumen. In the process of the intracoronary infusion of PBSCs, the complications should be observed, which were arrhythmias including of bradycardia, sinus arrest or atrial ventricular block, premature ve. ntricular beats ,ven~icular tachycardia, ventricular fibrillation; and hypotention, etc. Results There were total 10 cases with complications during the intracoronary infusion of PBSCs. The incidence of complications was 24.4% (10/41), including bradyca- rdia was 2.4 % (1/41), sinus arrest or atrial ventri- cular block was 4.0% (2/41), ventricular fibrillation was 2.4 % (1/41), hypotention was 14.6 % (6/41). Conclusions In patients with AMI, intracoronary infusion of PBSCs is feasible and safe.

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.

IGF-1, bFGF EXPRESSION AND VASCULAR REGENERATION IN ACUTE INFARCTED CANINE MYOCARDIUM AFTER AUTOLOGUS SKELETAL MUSCLE SATELLITE CELL IMPLANTATION

Objective To study the cell growth factor secretion and vascular regeneration in acute in-farcted myocardium after autologous skeletal muscle satellite cell implantation. Methods Autologous skeletal muscle satellite cells from adult mongrel canine were implanted into the acute myocardial infarct site via the ligated left anterior descending (LAD) artery. Specimens were harvested at 2, 4 , 8 weeks after implantation for the expression of insulin-like growth factor-1 (IGF-1), basic fibroblast growth factor ( bFGF) and the vascular density. Results The expression of IGF-1, bFGF and the vascular density in skeletal muscle satellite cell implant group were higher than that in the control group. Conclusion The skeletal muscle satellite cells, after being implanted into the acute myocardial infarction, not only showed myocardial regeneration, but also showed the ability to secrete the cell factors, hence representing a positive effect on the regeneration of the infarcted myocardium.

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。