Background Liraglutide is glucagon-like peptide-1 receptor agonist for treating patients with type 2 diabetes mellitus. Our previous studies have demonstrated that liraglutide protects cardiac function through improvi...Background Liraglutide is glucagon-like peptide-1 receptor agonist for treating patients with type 2 diabetes mellitus. Our previous studies have demonstrated that liraglutide protects cardiac function through improving endothelial function in patients with acute myocardial infarction undergoing percutaneous coronary intervention. The present study will investigate whether liraglntide can perform direct protective effects on cardiomyocytes against reperfusion injury. Methods In vitro experiments were performed using H9C2 cells and neonatal rat ventricular cadiomyocytes undergoing simulative hypoxia/reoxygenation （H/R） induction. Cardiomyocytes apoptosis was detected by fluorescence TUNEL. Mitochondrial membrane potential （AWm） and intracellular reactive oxygen species （ROS） was assessed by JC-1 and DHE, respectively. Fura-2/AM was used to measure intracellular Ca2＋ concentration and calcium transient. Immtmofluorescence staining was used to assess the expression level of sarcoplasmic reticulum Ca2＋-ATPase （SERCA2a）. In vivo experiments, myocardial apoptosis and expression of SERCA2a were detected by colorimetric TUNEL and by immunofluorescence staining, respectively. Results In vitro liraglutide inhibited cardiomyotes apoptosis against H/R. △mψ of cardiomyocytes was higher in liraglntide group than H/R group. H/R increased ROS production in H9C2 cells which was attenuated by liraglutide. Liraglutide significantly lowered Ca2＋ overload and improved calcium transient compared with H/R group, lmmunofluorescence staining results showed liraglutide promoted SERCA2a expression which was decreased in H/R group. In ischemia/reperfusion rat hearts, apoptosis was significantly attenuated and SERCA2a expression was increased by liraglutide compared with H/R group. Conclusions Liraglutide can directly protect cardiomyocytes against reperfusion injury which is possibly through modulation of intracellular calcium homeostasis.展开更多
AIM:To investigate serotonergic Ca 2+ signaling and the expression of 5-hydroxytryptamine(5-HT) receptors,as well as Ca 2+ transporting proteins,in hepatic stellate cells(HSCs) . METHODS:The intracellular Ca 2+ concen...AIM:To investigate serotonergic Ca 2+ signaling and the expression of 5-hydroxytryptamine(5-HT) receptors,as well as Ca 2+ transporting proteins,in hepatic stellate cells(HSCs) . METHODS:The intracellular Ca 2+ concentration([Ca 2+ ]i) of isolated rat HSCs was measured with a fluorescence microscopic imaging system.Quantitative PCR was per-formed to determine the transcriptional levels of 5-HT receptors and endoplasmic reticulum(ER) proteins involved in Ca 2+ storage and release in cultured rat HSCs. RESULTS:Distinct from quiescent cells,activated HSCs exhibited[Ca 2+ ]i transients following treatment with 5-HT,which was abolished by U-73122,a phospholipase C inhibitor.Upregulation of 5-HT2A and 5-HT2B receptors,but not 5-HT3,was prominent during trans-differentiation of HSCs.Pretreatment with ritanserin,a 5-HT2 antagonist,inhibited[Ca 2+ ]i changes upon application of 5-HT.Expression of type 1 inositol-5'-triphosphate receptor and type 2 sarcoplasmic/endoplasmic reticulum Ca 2+ ATPase were also increased during activation of HSCs and serve as the major isotypes for ER Ca 2+ storage and release in activated HSCs.Ca 2+ binding chaperone proteins of the ER,including calreticulin,calnexin and calsequestrin,were up-regulated following activation of HSCs. CONCLUSION:The appearance of 5-HT-induced[Ca 2+ ]i response accompanied by upregulation of metabotropic 5-HT2 receptors and Ca 2+ transporting/chaperone ER proteins may participate in the activating process of HSCs.展开更多
Objective： To compare the effect of Shen-Fu Injection （SFI） and epinephrine on the expression of sarcoplasmic reticulum Ca2. ATPase 2a （SERCA2a） in a pig model with post-resuscitation myocardial dysfunction. Meth...Objective： To compare the effect of Shen-Fu Injection （SFI） and epinephrine on the expression of sarcoplasmic reticulum Ca2. ATPase 2a （SERCA2a） in a pig model with post-resuscitation myocardial dysfunction. Methods： Ventricular fibrillation （VF） was electrically induced in Wu-zhi-shan miniature pigs. After 8 min of untreated VF and 2 min of cardiopulmonary resuscitation （CPR）, all animals were randomly administered a bolus injection of saline placebo （SA group, n=10）, SFI （0.8 mg/kg, SFI group, n=10） or epinephrine （20 t~ g/kg, EPI group, n=10）. After 4 min of CPR, a 100-J shock was delivered. If the defibrillation attempt failed to attain restoration of spontaneous circulation （ROSC）, manual chest compressions were rapidly resumed for a further 2 rain followed by a second defibrillation attempt. Hemodynamic variables were recorded, and plasma concentrations of catecholamines were measured. Adenylate cyclase （AC）, cyclic adenosine monophosphate （cAMP） and the expressions of 13 1-adrenoceptor （AR） and SERCA 2a were determined. Results： Cardiac output, left ventricular dp/dtr,~x and negative dp/dtm^x were significantly higher in the SFI group than in the SA and EPI groups at 4 and 6 h after ROSC. The expression of 13 1-AR and SERCA2a at 24 h after ROSC were significantly higher in the SFI group than in the SA and EPI groups （P〈0.05 or P〈0.01）. Conclusions： The administration of epinephrine during CPR decreased the expression of SERCA2a and aggravated postresuscitation myocardial function （P〈0.01）. SFI attenuated post-resuscitation myocardial dysfunction, and the mechanism might be related to the up-regulation of SERCA2a expression.展开更多
基金This work is supported by grants from National Natural Science Foundation of China （No. 81102079） and China Postdoctoral Science Foundation （No. 201003776）. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors report no conflict of interest. The authors are responsible for the content and writing of the paper.
文摘Background Liraglutide is glucagon-like peptide-1 receptor agonist for treating patients with type 2 diabetes mellitus. Our previous studies have demonstrated that liraglutide protects cardiac function through improving endothelial function in patients with acute myocardial infarction undergoing percutaneous coronary intervention. The present study will investigate whether liraglntide can perform direct protective effects on cardiomyocytes against reperfusion injury. Methods In vitro experiments were performed using H9C2 cells and neonatal rat ventricular cadiomyocytes undergoing simulative hypoxia/reoxygenation （H/R） induction. Cardiomyocytes apoptosis was detected by fluorescence TUNEL. Mitochondrial membrane potential （AWm） and intracellular reactive oxygen species （ROS） was assessed by JC-1 and DHE, respectively. Fura-2/AM was used to measure intracellular Ca2＋ concentration and calcium transient. Immtmofluorescence staining was used to assess the expression level of sarcoplasmic reticulum Ca2＋-ATPase （SERCA2a）. In vivo experiments, myocardial apoptosis and expression of SERCA2a were detected by colorimetric TUNEL and by immunofluorescence staining, respectively. Results In vitro liraglutide inhibited cardiomyotes apoptosis against H/R. △mψ of cardiomyocytes was higher in liraglntide group than H/R group. H/R increased ROS production in H9C2 cells which was attenuated by liraglutide. Liraglutide significantly lowered Ca2＋ overload and improved calcium transient compared with H/R group, lmmunofluorescence staining results showed liraglutide promoted SERCA2a expression which was decreased in H/R group. In ischemia/reperfusion rat hearts, apoptosis was significantly attenuated and SERCA2a expression was increased by liraglutide compared with H/R group. Conclusions Liraglutide can directly protect cardiomyocytes against reperfusion injury which is possibly through modulation of intracellular calcium homeostasis.
基金Supported by Grants from the Korean National Research Foun-dation(2010-0014617)the Myung Sun Kim Memorial Founda-tion(2009)the Yonsei University Faculty Research Grant(2004)
文摘AIM:To investigate serotonergic Ca 2+ signaling and the expression of 5-hydroxytryptamine(5-HT) receptors,as well as Ca 2+ transporting proteins,in hepatic stellate cells(HSCs) . METHODS:The intracellular Ca 2+ concentration([Ca 2+ ]i) of isolated rat HSCs was measured with a fluorescence microscopic imaging system.Quantitative PCR was per-formed to determine the transcriptional levels of 5-HT receptors and endoplasmic reticulum(ER) proteins involved in Ca 2+ storage and release in cultured rat HSCs. RESULTS:Distinct from quiescent cells,activated HSCs exhibited[Ca 2+ ]i transients following treatment with 5-HT,which was abolished by U-73122,a phospholipase C inhibitor.Upregulation of 5-HT2A and 5-HT2B receptors,but not 5-HT3,was prominent during trans-differentiation of HSCs.Pretreatment with ritanserin,a 5-HT2 antagonist,inhibited[Ca 2+ ]i changes upon application of 5-HT.Expression of type 1 inositol-5'-triphosphate receptor and type 2 sarcoplasmic/endoplasmic reticulum Ca 2+ ATPase were also increased during activation of HSCs and serve as the major isotypes for ER Ca 2+ storage and release in activated HSCs.Ca 2+ binding chaperone proteins of the ER,including calreticulin,calnexin and calsequestrin,were up-regulated following activation of HSCs. CONCLUSION:The appearance of 5-HT-induced[Ca 2+ ]i response accompanied by upregulation of metabotropic 5-HT2 receptors and Ca 2+ transporting/chaperone ER proteins may participate in the activating process of HSCs.
文摘Objective： To compare the effect of Shen-Fu Injection （SFI） and epinephrine on the expression of sarcoplasmic reticulum Ca2. ATPase 2a （SERCA2a） in a pig model with post-resuscitation myocardial dysfunction. Methods： Ventricular fibrillation （VF） was electrically induced in Wu-zhi-shan miniature pigs. After 8 min of untreated VF and 2 min of cardiopulmonary resuscitation （CPR）, all animals were randomly administered a bolus injection of saline placebo （SA group, n=10）, SFI （0.8 mg/kg, SFI group, n=10） or epinephrine （20 t~ g/kg, EPI group, n=10）. After 4 min of CPR, a 100-J shock was delivered. If the defibrillation attempt failed to attain restoration of spontaneous circulation （ROSC）, manual chest compressions were rapidly resumed for a further 2 rain followed by a second defibrillation attempt. Hemodynamic variables were recorded, and plasma concentrations of catecholamines were measured. Adenylate cyclase （AC）, cyclic adenosine monophosphate （cAMP） and the expressions of 13 1-adrenoceptor （AR） and SERCA 2a were determined. Results： Cardiac output, left ventricular dp/dtr,~x and negative dp/dtm^x were significantly higher in the SFI group than in the SA and EPI groups at 4 and 6 h after ROSC. The expression of 13 1-AR and SERCA2a at 24 h after ROSC were significantly higher in the SFI group than in the SA and EPI groups （P〈0.05 or P〈0.01）. Conclusions： The administration of epinephrine during CPR decreased the expression of SERCA2a and aggravated postresuscitation myocardial function （P〈0.01）. SFI attenuated post-resuscitation myocardial dysfunction, and the mechanism might be related to the up-regulation of SERCA2a expression.
