目的:通过大鼠原代心肌细胞培养,探讨心肌肥大过程中有关心肌细胞线粒体改变的病理和治疗问题。方法:分离和培养大鼠原代心肌细胞,并与血管紧张素Ⅱ(AngⅡ)共培养72,96 h。通过BCA法检测细胞总蛋白含量;倒置显微镜拍摄并测量细胞直径,...目的:通过大鼠原代心肌细胞培养,探讨心肌肥大过程中有关心肌细胞线粒体改变的病理和治疗问题。方法:分离和培养大鼠原代心肌细胞,并与血管紧张素Ⅱ(AngⅡ)共培养72,96 h。通过BCA法检测细胞总蛋白含量;倒置显微镜拍摄并测量细胞直径,反映心肌细胞增殖情况;通过荧光显微镜测量线粒体内膜膜电位(ΔΨm);酶标仪检测线粒体单胺氧化酶(MAO)活性;分光光度计检测线粒体细胞色素C氧化酶(COX)活性和线粒体外膜损伤百分率;高效液相色谱法检测心肌细胞内ATP,ADP,AMP含量,反映心肌细胞线粒结构和功能在与AngⅡ共培养中的损伤和能量代谢情况。在此基础上给予黄芪注射液和缬沙坦,观察它们对心肌细胞重构中线粒体结构、功能的药理作用。结果:在72,96 h 2个时间点,模型组较空白组心肌细胞总蛋白含量和心肌细胞直径均显著性增加。在该增殖过程中,心肌细胞线粒体MAO活性和线粒体外膜损伤百分率均显著升高,线粒体COX活性和线粒体ΔΨm均显著减低,ATP,ADP含量减少,AMP含量增加。黄芪注射液和缬沙坦能抑制AngⅡ引起的心肌细胞蛋白质合成增加和细胞直径增大、改善线粒体外膜损伤和内膜膜电位及COX,MAO活性,增加ATP,ADP含量、降低AMP含量。结论:在心肌肥大过程中,存在线粒体的结构和功能的损害,心肌细胞能量代谢损伤变化是继心肌细胞线粒体结构损伤后发生的。黄芪注射液和缬沙坦在逆转血管紧张素Ⅱ所引起的心肌细胞肥大的过程中具有保护心肌细胞线粒体结构和功能的作用,逆转心肌细胞肥大、纠正心肌重构有利于心肌细胞能量的改善。展开更多
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
Mitochondrial dysfunction in neurons has been implicated in hypoxia-ischemia-induced brain injury.Although mesenchymal stem cell therapy has emerged as a novel treatment for this pathology,the mechanisms are not fully...Mitochondrial dysfunction in neurons has been implicated in hypoxia-ischemia-induced brain injury.Although mesenchymal stem cell therapy has emerged as a novel treatment for this pathology,the mechanisms are not fully understood.To address this issue,we first co-cultured 1.5×10^5 PC12 cells with mesenchymal stem cells that were derived from induced pluripotent stem cells at a ratio of 1:1,and then intervened with cobalt chloride(CoCl2)for 24 hours.Reactive oxygen species in PC12 cells was measured by Mito-sox.Mitochondrial membrane potential(ΔΨm)in PC12 cells was determined by JC-1 staining.Apoptosis of PC12 cells was detected by terminal deoxynucleotidal transferase-mediated dUTP nick end-labeling staining.Mitochondrial morphology in PC12 cells was examined by transmission electron microscopy.Transfer of mitochondria from the mesenchymal stem cells derived from induced pluripotent stem cells to damaged PC12 cells was measured by flow cytometry.Mesenchymal stem cells were induced from pluripotent stem cells by lentivirus infection containing green fluorescent protein in mitochondria.Then they were co-cultured with PC12 cells in Transwell chambers and treated with CoCl2 for 24 hours to detect adenosine triphosphate level in PC12 cells.CoCl2-induced PC12 cell damage was dose-dependent.Co-culture with mesenchymal stem cells significantly reduced apoptosis and restoredΔΨm in the injured PC12 cells under CoCl2 challenge.Co-culture with mesenchymal stem cells ameliorated mitochondrial swelling,the disappearance of cristae,and chromatin margination in the injured PC12 cells.After direct co-culture,mitochondrial transfer from the mesenchymal stem cells stem cells to PC12 cells was detected via formed tunneling nanotubes between these two types of cells.The transfer efficiency was greatly enhanced in the presence of CoCl2.More importantly,inhibition of tunneling nanotubes partially abrogated the beneficial effects of mesenchymal stem cells on CoCl2-induced PC12 cell injury.Mesenchymal stem cells reduced CoCl2-induced展开更多
Mitochondrial damage is a critical driver in myocardial ischemia-reperfusion(I/R)injury and can be alleviated via the mitochondrial transplantation.The efficiency of mitochondrial transplantation is determined by mito...Mitochondrial damage is a critical driver in myocardial ischemia-reperfusion(I/R)injury and can be alleviated via the mitochondrial transplantation.The efficiency of mitochondrial transplantation is determined by mitochondrial vitality.Because aldehyde dehydrogenase 2(ALDH2)has a key role in regulating mitochondrial homeostasis,we aimed to investigate its potential therapeutic effects on mitochondrial transplantation via the use of ALDH2 activator,Alda-1.Our present study demonstrated that time-dependent internalization of exogenous mitochondria by cardiomyocytes along with ATP production were significantly increased in response to mitochondrial transplantation.Furthermore,Alda-1 treatment remarkably promoted the oxygen consumption rate and baseline mechanical function of cardiomyocytes caused by mitochondrial transplantation.Mitochondrial transplantation inhibited cardiomyocyte apoptosis induced by the hypoxia-reoxygenation exposure,independent of Alda-1 treatment.However,promotion of the mechanical function of cardiomyocytes exposed to hypoxia-reoxygenation treatment was only observed after mitochondrial Alda-1 treatment and transplantation.By using a myocardial I/R mouse model,our results revealed that transplantation of Alda-1-treated mitochondria into mouse myocardial tissues limited the infarction size after I/R injury,which was at least in part due to increased mitochondrial potential-mediated fusion.In conclusion,ALDH2 activation in mitochondrial transplantation shows great potential for the treatment of myocardial I/R injury.展开更多
Background:Acute lung injury (ALI) is characterized by an acute inflammatory process, and oxidative stress in the lung tissue leads to a lack of effective therapeutics. This study aimed to identify whether the overexp...Background:Acute lung injury (ALI) is characterized by an acute inflammatory process, and oxidative stress in the lung tissue leads to a lack of effective therapeutics. This study aimed to identify whether the overexpression of transcription factor EB (TFEB) regulates mitophagy to protect against lipopolysaccharide (LPS)-induced ALI. Methods: We detected the expression of inflammatory factors, cytochrome c (Cyt.c) and nicotinamide adenine dinucleotide phosphate (NADPH), and autophagy-related proteins and observed the changes in lung histopathology induced by ALI in rats and the changes in the cell ultrastructure of primary alveolar type II epithelial cells induced by changing the expression of TFEB in the context of ALI. Results: The overexpression of TFEB could reduce the expression of proinflammatory factors, such as IL-1 and IL-6, and increase the expression of anti-inflammatory factors, such as IL-10, both in vitro and in vivo. In addition, the overexpression of TFEB could reduce the Cyt.c and NADPH levels both in vivo and in vitro. The overexpression of TFEB could upregulate the expression of autophagy-related proteins, such as lysosomal-associated membrane protein 1 (LAMP1), microtubule-associated protein light chain 3B (LC3B), and Beclin both in vivo and in vitro^ and promote mitochondrial autophagy. The overexpression of TFEB significantly improved the histopathologic changes induced by LPS-induced ALI in rats. However, low TFEB expression produced the opposite results. Conclusion: TFEB overexpression can decrease inflammation and mitochondrial damage in the lung tissue and alveolar epithelial cells through regulating mitochondrial autophagy to protect against LPS-induced ALI. Therefore, TFEB is likely a potential therapeutic target in LPS-induced ALI.展开更多
Objective:To investigate the protective effect of different cyclosporin A(CsA)doses on myocardial ischemia/reperfusion injury in rat models.Methods:A rat model of myocardial ischemia/reperfusion injury was established...Objective:To investigate the protective effect of different cyclosporin A(CsA)doses on myocardial ischemia/reperfusion injury in rat models.Methods:A rat model of myocardial ischemia/reperfusion injury was established in vivo and the rats were randomly divided into four groups:placebo(PBS;T1),low-dose(CsA dose:1.0 mg/kg:T2),medium-dose(CsA dose:2.5 mg/kg:T3),and high-dose(CsA dose:5.0 mg/kg;T4)groups.Heart function indexes were monitored at different time points,the extent of myocardial infarction was assessed by Evans Blue-TTC staining,and creatine kinase MB mass and cardiac troponin 1 values were measured by biochemical assays.Results:Compared with the T1 and T2 groups,both the creatine kinase MB mass and cardiac troponin 1 were significantly lower in the T3 and T4 groups(P<0.05).The mean arterial pressure(MAP)and left ventricular systolic pressure(LVSP)decreased sequentially in each group,with the extending reperfusion time.Significant decreases in LVSP and MAP were observed in the T3 and T4 groups as compared to the T1 and T2 group(P<0.05)and the T2 group showed a significantly lower LVSP and MAP decline than the T1 group(P<0.05).Compared with the Tl group,the rats from the T2.T3,and T4 groups suffered from a significantly lower extent of myocardial infarction(P<0.05).Also,the a animals in the T3 and T4 groups had a significantly smaller extent of myocardial infarction than those in the T2 group(P<0.05).Conclusions:Various CsA doses exert different degrees of protection against ischemia/reperfusion injury,and this protective effect peaks at approximately 2.5 mg/kg in rat models.展开更多
文摘目的:通过大鼠原代心肌细胞培养,探讨心肌肥大过程中有关心肌细胞线粒体改变的病理和治疗问题。方法:分离和培养大鼠原代心肌细胞,并与血管紧张素Ⅱ(AngⅡ)共培养72,96 h。通过BCA法检测细胞总蛋白含量;倒置显微镜拍摄并测量细胞直径,反映心肌细胞增殖情况;通过荧光显微镜测量线粒体内膜膜电位(ΔΨm);酶标仪检测线粒体单胺氧化酶(MAO)活性;分光光度计检测线粒体细胞色素C氧化酶(COX)活性和线粒体外膜损伤百分率;高效液相色谱法检测心肌细胞内ATP,ADP,AMP含量,反映心肌细胞线粒结构和功能在与AngⅡ共培养中的损伤和能量代谢情况。在此基础上给予黄芪注射液和缬沙坦,观察它们对心肌细胞重构中线粒体结构、功能的药理作用。结果:在72,96 h 2个时间点,模型组较空白组心肌细胞总蛋白含量和心肌细胞直径均显著性增加。在该增殖过程中,心肌细胞线粒体MAO活性和线粒体外膜损伤百分率均显著升高,线粒体COX活性和线粒体ΔΨm均显著减低,ATP,ADP含量减少,AMP含量增加。黄芪注射液和缬沙坦能抑制AngⅡ引起的心肌细胞蛋白质合成增加和细胞直径增大、改善线粒体外膜损伤和内膜膜电位及COX,MAO活性,增加ATP,ADP含量、降低AMP含量。结论:在心肌肥大过程中,存在线粒体的结构和功能的损害,心肌细胞能量代谢损伤变化是继心肌细胞线粒体结构损伤后发生的。黄芪注射液和缬沙坦在逆转血管紧张素Ⅱ所引起的心肌细胞肥大的过程中具有保护心肌细胞线粒体结构和功能的作用,逆转心肌细胞肥大、纠正心肌重构有利于心肌细胞能量的改善。
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 National Natural Science Foundation of China,No.81671882,81471832the Natural Science Foundation of Guangdong Province of China,No.2016A030311039+1 种基金the Science and Technology Foundation of Guangdong Province of China,No.2015A020212012,2017A020224012the Science and Technology Foundation of Guangzhou City of China,No.201707010373(all to XL)
文摘Mitochondrial dysfunction in neurons has been implicated in hypoxia-ischemia-induced brain injury.Although mesenchymal stem cell therapy has emerged as a novel treatment for this pathology,the mechanisms are not fully understood.To address this issue,we first co-cultured 1.5×10^5 PC12 cells with mesenchymal stem cells that were derived from induced pluripotent stem cells at a ratio of 1:1,and then intervened with cobalt chloride(CoCl2)for 24 hours.Reactive oxygen species in PC12 cells was measured by Mito-sox.Mitochondrial membrane potential(ΔΨm)in PC12 cells was determined by JC-1 staining.Apoptosis of PC12 cells was detected by terminal deoxynucleotidal transferase-mediated dUTP nick end-labeling staining.Mitochondrial morphology in PC12 cells was examined by transmission electron microscopy.Transfer of mitochondria from the mesenchymal stem cells derived from induced pluripotent stem cells to damaged PC12 cells was measured by flow cytometry.Mesenchymal stem cells were induced from pluripotent stem cells by lentivirus infection containing green fluorescent protein in mitochondria.Then they were co-cultured with PC12 cells in Transwell chambers and treated with CoCl2 for 24 hours to detect adenosine triphosphate level in PC12 cells.CoCl2-induced PC12 cell damage was dose-dependent.Co-culture with mesenchymal stem cells significantly reduced apoptosis and restoredΔΨm in the injured PC12 cells under CoCl2 challenge.Co-culture with mesenchymal stem cells ameliorated mitochondrial swelling,the disappearance of cristae,and chromatin margination in the injured PC12 cells.After direct co-culture,mitochondrial transfer from the mesenchymal stem cells stem cells to PC12 cells was detected via formed tunneling nanotubes between these two types of cells.The transfer efficiency was greatly enhanced in the presence of CoCl2.More importantly,inhibition of tunneling nanotubes partially abrogated the beneficial effects of mesenchymal stem cells on CoCl2-induced PC12 cell injury.Mesenchymal stem cells reduced CoCl2-induced
基金This work was supported by grants from the National Science Fund for Distinguished Young Scholars(817200010)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(81521001)+1 种基金the National Natural Science Foundation of China(81900353)the China Postdoctoral Science Foundation(2019M651377).
文摘Mitochondrial damage is a critical driver in myocardial ischemia-reperfusion(I/R)injury and can be alleviated via the mitochondrial transplantation.The efficiency of mitochondrial transplantation is determined by mitochondrial vitality.Because aldehyde dehydrogenase 2(ALDH2)has a key role in regulating mitochondrial homeostasis,we aimed to investigate its potential therapeutic effects on mitochondrial transplantation via the use of ALDH2 activator,Alda-1.Our present study demonstrated that time-dependent internalization of exogenous mitochondria by cardiomyocytes along with ATP production were significantly increased in response to mitochondrial transplantation.Furthermore,Alda-1 treatment remarkably promoted the oxygen consumption rate and baseline mechanical function of cardiomyocytes caused by mitochondrial transplantation.Mitochondrial transplantation inhibited cardiomyocyte apoptosis induced by the hypoxia-reoxygenation exposure,independent of Alda-1 treatment.However,promotion of the mechanical function of cardiomyocytes exposed to hypoxia-reoxygenation treatment was only observed after mitochondrial Alda-1 treatment and transplantation.By using a myocardial I/R mouse model,our results revealed that transplantation of Alda-1-treated mitochondria into mouse myocardial tissues limited the infarction size after I/R injury,which was at least in part due to increased mitochondrial potential-mediated fusion.In conclusion,ALDH2 activation in mitochondrial transplantation shows great potential for the treatment of myocardial I/R injury.
基金Natural Science Foundation of China (No.81600053).
文摘Background:Acute lung injury (ALI) is characterized by an acute inflammatory process, and oxidative stress in the lung tissue leads to a lack of effective therapeutics. This study aimed to identify whether the overexpression of transcription factor EB (TFEB) regulates mitophagy to protect against lipopolysaccharide (LPS)-induced ALI. Methods: We detected the expression of inflammatory factors, cytochrome c (Cyt.c) and nicotinamide adenine dinucleotide phosphate (NADPH), and autophagy-related proteins and observed the changes in lung histopathology induced by ALI in rats and the changes in the cell ultrastructure of primary alveolar type II epithelial cells induced by changing the expression of TFEB in the context of ALI. Results: The overexpression of TFEB could reduce the expression of proinflammatory factors, such as IL-1 and IL-6, and increase the expression of anti-inflammatory factors, such as IL-10, both in vitro and in vivo. In addition, the overexpression of TFEB could reduce the Cyt.c and NADPH levels both in vivo and in vitro. The overexpression of TFEB could upregulate the expression of autophagy-related proteins, such as lysosomal-associated membrane protein 1 (LAMP1), microtubule-associated protein light chain 3B (LC3B), and Beclin both in vivo and in vitro^ and promote mitochondrial autophagy. The overexpression of TFEB significantly improved the histopathologic changes induced by LPS-induced ALI in rats. However, low TFEB expression produced the opposite results. Conclusion: TFEB overexpression can decrease inflammation and mitochondrial damage in the lung tissue and alveolar epithelial cells through regulating mitochondrial autophagy to protect against LPS-induced ALI. Therefore, TFEB is likely a potential therapeutic target in LPS-induced ALI.
基金financially supported by Key Science and Technology Project of Haikou City,with grant number 2011-0142
文摘Objective:To investigate the protective effect of different cyclosporin A(CsA)doses on myocardial ischemia/reperfusion injury in rat models.Methods:A rat model of myocardial ischemia/reperfusion injury was established in vivo and the rats were randomly divided into four groups:placebo(PBS;T1),low-dose(CsA dose:1.0 mg/kg:T2),medium-dose(CsA dose:2.5 mg/kg:T3),and high-dose(CsA dose:5.0 mg/kg;T4)groups.Heart function indexes were monitored at different time points,the extent of myocardial infarction was assessed by Evans Blue-TTC staining,and creatine kinase MB mass and cardiac troponin 1 values were measured by biochemical assays.Results:Compared with the T1 and T2 groups,both the creatine kinase MB mass and cardiac troponin 1 were significantly lower in the T3 and T4 groups(P<0.05).The mean arterial pressure(MAP)and left ventricular systolic pressure(LVSP)decreased sequentially in each group,with the extending reperfusion time.Significant decreases in LVSP and MAP were observed in the T3 and T4 groups as compared to the T1 and T2 group(P<0.05)and the T2 group showed a significantly lower LVSP and MAP decline than the T1 group(P<0.05).Compared with the Tl group,the rats from the T2.T3,and T4 groups suffered from a significantly lower extent of myocardial infarction(P<0.05).Also,the a animals in the T3 and T4 groups had a significantly smaller extent of myocardial infarction than those in the T2 group(P<0.05).Conclusions:Various CsA doses exert different degrees of protection against ischemia/reperfusion injury,and this protective effect peaks at approximately 2.5 mg/kg in rat models.
