Mitochondrial damage is a critical contributor to cardiac ischemia/reperfusion(I/R)injury.Mitochondrial quality control(MQC)mechanisms,a series of adaptive responses that preserve mitochondrial structure and function,...Mitochondrial damage is a critical contributor to cardiac ischemia/reperfusion(I/R)injury.Mitochondrial quality control(MQC)mechanisms,a series of adaptive responses that preserve mitochondrial structure and function,ensure cardiomyocyte survival and cardiac function after I/R injury.MQC includes mitochondrial fission,mitochondrial fusion,mitophagy and mitochondria-dependent cell death.The interplay among these responses is linked to pathological changes such as redox imbalance,calcium overload,energy metabolism disorder,signal transduction arrest,the mitochondrial unfolded protein response and endoplasmic reticulum stress.Excessive mitochondrial fission is an early marker of mitochondrial damage and cardiomyocyte death.Reduced mitochondrial fusion has been observed in stressed cardiomyocytes and correlates with mitochondrial dysfunction and cardiac depression.Mitophagy allows autophagosomes to selectively degrade poorly structured mitochondria,thus maintaining mitochondrial network fitness.Nevertheless,abnormal mitophagy is maladaptive and has been linked to cell death.Although mitochondria serve as the fuel source of the heart by continuously producing adenosine triphosphate,they also stimulate cardiomyocyte death by inducing apoptosis or necroptosis in the reperfused myocardium.Therefore,defects in MQC may determine the fate of cardiomyocytes.In this review,we summarize the regulatory mechanisms and pathological effects of MQC in myocardial I/R injury,highlighting potential targets for the clinical management of reperfusion.展开更多
Objective： To investigate whether the administration of the ultra-filtration extract from Danggui Buxue Decoction （当归补血汤, EDBD） was able to protect cardiomyocytes from oxidative injury of rats induced by hydro...Objective： To investigate whether the administration of the ultra-filtration extract from Danggui Buxue Decoction （当归补血汤, EDBD） was able to protect cardiomyocytes from oxidative injury of rats induced by hydrogen peroxide （H2O2） and its potential mechanism. Methods： Myocardial cells from 1- to 2-day-old neonatal rats were cultured in Dulbecco＇s modified Eagle＇s medium low-glucose and Ham＇s F12 medium （1：1）, and the cellular injury was induced by H2O2. The ultra-filtration extract mixture from Angelica sinensis and Hedysarurn po/ybotrys was given in three doses of 3.75, 7.5, and 15 mg/mL. Morphological changes of cardiomyocytes were observed by microscope. Survival rate of myocardial cells was assessed using 3-（4,5-dimethylthiazol-2-yl）-2,5- diphenyltetrazolium bromide （Ml-r） assay. The cardiomyocyte damages were estimated by detecting lactate dehydrogenase （LDH） and creatine kinase （CK） releases in the medium, superoxide dismutase （SOD） activities, and intracellular malondialdehyde （MDA） and myeloperoxidase （MPO） contents. The levels of caspase-3 and heat shock protein 70 （hsp70） mRNA expression in cardiomyocytes were measured by reverse transcription polymerase chain reaction. Results： The EDBD could protect the cardiomyocytes from H202 injury in a dose- dependent manner （3.75, 7.50, and 15.00 mg/mL）. The EDBD could significantly decrease LDH and CK leakages and intracellular MDA and MPO contents, increase SOD activity, up-regulate hsp70 expression, and down-regulate caspase-3 expression. Conclusion： The EDBD has protection on cardiomyocytes injured by H202 through improving cell antioxidant ability, up-regulating hsp70 expression, and inhibiting caspase-3 activity.展开更多
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
基金partially supported by the China Postdoctoral Science Foundation(2019TQ0128)the National Natural Science Foundation of China(NSFC81900252,81900254 and 81870249)
文摘Mitochondrial damage is a critical contributor to cardiac ischemia/reperfusion(I/R)injury.Mitochondrial quality control(MQC)mechanisms,a series of adaptive responses that preserve mitochondrial structure and function,ensure cardiomyocyte survival and cardiac function after I/R injury.MQC includes mitochondrial fission,mitochondrial fusion,mitophagy and mitochondria-dependent cell death.The interplay among these responses is linked to pathological changes such as redox imbalance,calcium overload,energy metabolism disorder,signal transduction arrest,the mitochondrial unfolded protein response and endoplasmic reticulum stress.Excessive mitochondrial fission is an early marker of mitochondrial damage and cardiomyocyte death.Reduced mitochondrial fusion has been observed in stressed cardiomyocytes and correlates with mitochondrial dysfunction and cardiac depression.Mitophagy allows autophagosomes to selectively degrade poorly structured mitochondria,thus maintaining mitochondrial network fitness.Nevertheless,abnormal mitophagy is maladaptive and has been linked to cell death.Although mitochondria serve as the fuel source of the heart by continuously producing adenosine triphosphate,they also stimulate cardiomyocyte death by inducing apoptosis or necroptosis in the reperfused myocardium.Therefore,defects in MQC may determine the fate of cardiomyocytes.In this review,we summarize the regulatory mechanisms and pathological effects of MQC in myocardial I/R injury,highlighting potential targets for the clinical management of reperfusion.
基金Supported by the Key Projects of the National Science and Technology Pillar Program during the Eleventh Five-Year Plan Period(No.2007BAI37B01)Major Science and Technology Program of Gansu Province(No.092NKDA017)
文摘Objective： To investigate whether the administration of the ultra-filtration extract from Danggui Buxue Decoction （当归补血汤, EDBD） was able to protect cardiomyocytes from oxidative injury of rats induced by hydrogen peroxide （H2O2） and its potential mechanism. Methods： Myocardial cells from 1- to 2-day-old neonatal rats were cultured in Dulbecco＇s modified Eagle＇s medium low-glucose and Ham＇s F12 medium （1：1）, and the cellular injury was induced by H2O2. The ultra-filtration extract mixture from Angelica sinensis and Hedysarurn po/ybotrys was given in three doses of 3.75, 7.5, and 15 mg/mL. Morphological changes of cardiomyocytes were observed by microscope. Survival rate of myocardial cells was assessed using 3-（4,5-dimethylthiazol-2-yl）-2,5- diphenyltetrazolium bromide （Ml-r） assay. The cardiomyocyte damages were estimated by detecting lactate dehydrogenase （LDH） and creatine kinase （CK） releases in the medium, superoxide dismutase （SOD） activities, and intracellular malondialdehyde （MDA） and myeloperoxidase （MPO） contents. The levels of caspase-3 and heat shock protein 70 （hsp70） mRNA expression in cardiomyocytes were measured by reverse transcription polymerase chain reaction. Results： The EDBD could protect the cardiomyocytes from H202 injury in a dose- dependent manner （3.75, 7.50, and 15.00 mg/mL）. The EDBD could significantly decrease LDH and CK leakages and intracellular MDA and MPO contents, increase SOD activity, up-regulate hsp70 expression, and down-regulate caspase-3 expression. Conclusion： The EDBD has protection on cardiomyocytes injured by H202 through improving cell antioxidant ability, up-regulating hsp70 expression, and inhibiting caspase-3 activity.
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.
