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Objective@#To investigate the protective effect of glucose regulatory protein 78 (GRP78) on cardiomyocytes in atrial fibrillation and its mechanism.@*Methods@#HL-1 cardiomyocyte cell line was cultured from June 2016 to March 2017 at Harbin Medical University Central Laboratory.The cells were randomly divided into 4 groups: control group, pacing group, pacing+ GRP78cDNA group, pacing+ GRP78siRNA group.The following indicators were detected: (1)oxidative stress: flow cytometry was used to detect the content of reactive oxygen species (ROS) in each group; (2)Ca2+ overload and cell electrophysiology: flow cytometry was used to detect Ca2+ content in each group; (3)cell structure reconstruction: cell apoptosis was detected by flow cytometry.@*Results@#The ROS production in the pacing group was significantly higher than that in the control group [(28.8±0.5)% vs.(4.5±0.8)%, F=27.91, P<0.01]. The number of ROS in the GRP78siRNA group was significantly higher than that in the pacing group [(71.1±0.3%) vs.(28.8±0.5)%, F=34.12, P<0.01]. The ROS content of the GRP78cDNA group was lower than that of the pacing group [(26.1±2.7)% vs.(28.8±0.5)%, F=26.60, P<0.01]. Pacing significantly increased Ca2+ concentration in HL-1 cells; GRP concentration in HL-1 cells in the GRP78siRNA group was significantly higher than that in the pacing group [(72.53±2.5)AM vs.(39.23±1.9)AM, F=19.50, P<0.05]. The intracellular Ca2+ concentration in the GRP78cDNA group was significantly lower than that in the pacing group [(31.23±0.57)AM vs.(39.23±1.9)AM, F=28.17, P<0.01]. The survival rate of the GRP78cDNA group was significantly higher than that of the pacing group [(87.9±0.4)% vs.(80.1±0.5)%, F=19, P<0.05].@*Conclusion@#GRP78 protein reduces intracellular calcium overload by reducing ROS production in myocardial cells during atrial fibrillation.It can alleviate the oxidative stress of cardiomyocytes and improve the survival rate of cardiomyocytes, and has protective effect on cardiomyocytes.
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Objective To investigate the protective effect of glucose regulatory protein 78 ( GRP78) on cardiomyocytes in atrial fibrillation and its mechanism.Methods HL-1 cardiomyocyte cell line was cultured from June 2016 to March 2017 at Harbin Medical University Central Laboratory. The cells were randomly divided into 4 groups:control group, pacing group, pacing + GRP78cDNA group, pacing + GRP78siRNA group. The following indicators were detected:(1)oxidative stress:flow cytometry was used to detect the content of reactive oxygen species (ROS) in each group;(2)Ca2+ overload and cell electrophysiology:flow cytometry was used to detect Ca2+ content in each group; ( 3 ) cell structure reconstruction: cell apoptosis was detected by flow cytometry. Results The ROS production in the pacing group was significantly higher than that in the control group [(28.8 ± 0.5)% vs.(4.5 ± 0.8)%,F=27.91,P＜0.01].The number of ROS in the GRP78siRNA group was significantly higher than that in the pacing group [(71.1 ± 0.3%) vs.(28.8 ± 0.5)%,F=34.12,P＜0.01].The ROS content of the GRP78cDNA group was lower than that of the pacing group [(26.1 ± 2.7)% vs.(28.8 ± 0.5)%,F=26.60,P＜0.01].Pacing significantly increased Ca2+ concentration in HL-1 cells;GRP concentration in HL-1 cells in the GRP78siRNA group was significantly higher than that in the pacing group [(72.53 ± 2.5)AM vs.(39.23 ± 1.9)AM,F=19.50, P＜0.05].The intracellular Ca2+ concentration in the GRP78cDNA group was significantly lower than that in the pacing group [(31.23 ± 0. 57 ) AM vs.(39. 23 ± 1. 9 ) AM, F =28. 17, P ＜0. 01 ]. The survival rate of the GRP78cDNA group was significantly higher than that of the pacing group [(87.9 ± 0.4)% vs.(80.1 ± 0.5)%,F=19,P＜0.05].Conclusion GRP78 protein reduces intracellular calcium overload by reducing ROS production in myocardial cells during atrial fibrillation.It can alleviate the oxidative stress of cardiomyocytes and improve the survival rate of cardiomyocytes,and has protective effect on cardiomyocytes.
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Objective To test whether cardiosphere-derived cells(CDCs)were sufficient to decrease manifestations of heart failure with preserved ejection fraction(HFpEF)in hypertensive rats.Methods DS rats(Charles River,Wilmington,Massachusetts)were fed 0.3% NaCl(low-salt)diet until 7 weeks of age.At that time,the diet was switched to an 8% NaCl(high-salt)diet in rats by random assignment.DS rats fed the low-salt diet constituted the control group(n=20).At 13 to 14 weeks of age,rats with the high-salt diet were randomized to receive allogeneic rat CDCs or PBS.Echocardiography long-axis images of the left ventricular systolic and diastolic dimensions.Sirius red was used to assess fibrosis and proliferation.Results E/A ratio increased in the PBS-treated group compared with the control group and the CDCs-treated group [(1.20±0.30)vs.(1.70±0.20)or(1.80±0.16),t=0.782,0.844,all P<0.001].LAA kept increasing in the PBS-treated group[(27.20±1.10)mm2 vs.(19.80±0.76)mm2 or(17.80±0.82)mm2,t=0.892,0.774,all P<0.001].The time constant of isovolumic LV pressure fall was prolonged in placebo-treated animals compared with CDCs-treated animals and control rats[(6.2±0.3)×103 mmHg/s vs.(9.4±0.4)×103 mmHg/s,t=0.382,P=0.024;(6.2±0.3)×103 mmHg/s vs.(9.1±0.5)×103 mmHg/s,t=0.883,P=0.022].LVEDP was 2-fold higher in placebo-treated group than in CDC-treated and control animals[(17±10)mmHg vs.(8±3)mmHg,t=0.922,P=0.003;(17±10)mmHg vs.(9±4)mmHg,t=0.922,P=0.004].A dramatic improvement of survival was observed in CDC-treated rats(Kaplan-Meier survival curves)(P=0.027).Cardiac myofibroblasts increased dramatically in PBS-treated(110/field vs.46/field,P<0.001).Inflammatory cytokines expression siginficantly increased in PBS-treated group.Conclusion CDCs improves survival in a rat model of HFpEF through reducing inflammation and fibrosis.
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Objective To investigate whether cardiosphere-derived cells (CDCs)can protect ischemia-reperfusion in acute myocardial infarction,and to explore its mechanism.Methods 7 -10 week-old female Wistar-Kyoto (WKY)rats were used for all in vivo experiment.Ischemia was induced for 45 min to allow reperfusion. Twenty minutes (or two hours)later,CDCs (or PBS control)were injected into the LV cavity with an aortic cross-clamp.After 48 hours and 2 weeks,representative echocardiography long-axis images of the left ventricular (LV) systolic and diastolic dimensions,the protein level of activated caspase-3 were observed,the apoptosis rate of myo-cardial cells and the infarct area of the heart were determined in those groups.Results Rats underwent 45 minutes of ischemia,followed by either 20 minutes or 120 minutes (delayed injection)of reperfusion prior to infusion of CDCs (cells per 100μL)or PBS control (100μL)into the LV cavity during aortic cross-clamp.Ejection fraction,as meas-ured by echocardiography,was significantly preserved in CDCs-treated animals at 48 hours with a 20 -minute,but not a 120-minute,delay of infusion(28.0% vs 38.0%,χ2 =7.340,P=0.008).CDCs-treated animals reduced percentage of infarct mass(6.2% vs 13.4%,χ2 =4.226,P=0.002;6.2% vs 13.5%,χ2 =1.853,P=0.003), infarct mass(6.2% vs 13.4%,χ2 =2.220,P=0.002;6.2% vs 13.5%,χ2 =3.119,P=0.003)treated with PBS control.CDC-treated animals reduced infarct size,relative to those of animals treated with PBS control(45.0% vs 24.0%,χ2 =4.825,P=0.008),less thinning of the LV anterior wall(1.96mm vs 1.45mm,t=0.897,P=0.028). Protein expressions of MMP-8 and CXGL7 were elevated in the infarct zone of hearts treated with CDCs(MMP-8:0.74 vs 0.56,t=0.657,P=0.014;CXGL7:0.44 vs 0.81,t=0.791,P=0.010).Conclusion CDCs is suggested to be a promising cell source to repair acute myocardial infarction through inhibiting apoptosis and reduce proinflam-matory cytokine expression.
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Objective:To review the chemical and pharmacological activities of Codonopsis lanceolata in order to provide reference for the further development of C. lanceolata. Methods:The related literatures at home and abroad in the past 40 years were reviewed and analyzed, and then the chemical components and pharmacological actions of C. lanceolata were summarized. Results: The major chemical constiturents in C. lanceolata were terpenoids, alkaloids, phenylethanoid glycoside and flavonoids. The pharmacological ac-tivities were antioxidation, anti-inflammatory, anti-tumor, antiplatelet aggregation, hypoglycemic and hypolipidemic effects, etc. Con-clusion:The review provides reference for the further development and comprehensive utilization of C. lanceolata. The development of relevant safe and effective agents is still needed, and at present, the definition of mechanism and the extension of clinical application remain as the primary tasks of the exploration of C. lanceolata.
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Objective To observe the Leu72Met single nucleotide polymorphism (SNP)of ghrelin gene and the relationship with essential hypertension (EH).Methods Polymerase chain reaction -restriction fragment length polymorphism (PCR -RFLP)was used to detect the Leu72Met SNP of ghrelin gene in 210 EH patients and 220 healthy controls.The plasma ghrelin was detected by radioimmunoassay method collected from all subjects. Results There were three types of polymorphism of ghrelin gene at the base site Leu72Met.There were significant differences in the genotypes (CC,CA,AA)and alleles (C,A)between the EH patients and the controls (χ2 =6.054,P =0.048;χ2 =5.866,P =0.015).In EH group,the plasma ghrelin level in subjects who were homozygous CC without mutant was not only significantly lower than those who were heterozygous CA,but also lower than those who were nucleotide homozygous mutant AA (t =-8.738,P =0.000;t =-5.103,P =0.000).The patients with CC genotype had higher SBP (t =4.298,P =0.000;t =2.236,P =0.019)and lower HDL -C (t =-11.682,P =0.000;t =-7.872,P =0.000).The patients with A allele had lower plasma ghrelin (t =-16.264,P =0.000), HDL -C (t =-15.332,P =0.000)and higher SBP(t =3.800,P =0.000),DBP(t =11.895,P =0.000),and LDL -C (t =38.401,P =0.000).Conclusion The Leu72Met SNP of ghrelin gene is significantly related to the susceptibility of EH.Base mutation C to A reduced the incidence of EH.The Leu72Met polymorphism of ghrelin gene is related to the plasma ghrelin,blood pressure and blood lipid metabolism.Base mutation C to A elevated plasma ghrelin,and lowered blood pressure and blood lipid.