BACKGROUND Intestinal ischemia reperfusion(I/R)occurs in various diseases,such as trauma and intestinal transplantation.Excessive reactive oxygen species(ROS)accumulation and subsequent apoptotic cell death in intesti...BACKGROUND Intestinal ischemia reperfusion(I/R)occurs in various diseases,such as trauma and intestinal transplantation.Excessive reactive oxygen species(ROS)accumulation and subsequent apoptotic cell death in intestinal epithelia are important causes of I/R injury.PTEN-induced putative kinase 1(PINK1)and phosphorylation of dynamin-related protein 1(DRP1)are critical regulators of ROS and apoptosis.However,the correlation of PINK1 and DRP1 and their function in intestinal I/R injury have not been investigated.Thus,examining the PINK1/DRP1 pathway may help to identify a protective strategy and improve the patient prognosis.AIM To clarify the mechanism of the PINK1/DRP1 pathway in intestinal I/R injury.METHODS Male C57BL/6 mice were used to generate an intestinal I/R model via superior mesenteric artery occlusion followed by reperfusion.Chiu’s score was used to evaluate intestinal mucosa damage.The mitochondrial fission inhibitor mdivi-1 was administered by intraperitoneal injection.Caco-2 cells were incubated in vitro in hypoxia/reoxygenation conditions.Small interfering RNAs and overexpression plasmids were transfected to regulate PINK1 expression.The protein expression levels of PINK1,DRP1,p-DRP1 and cleaved caspase 3 were measured by Western blotting.Cell viability was evaluated using a Cell Counting Kit-8 assay and cell apoptosis was analyzed by TUNEL staining.Mitochondrial fission and ROS were tested by MitoTracker and MitoSOX respectively.RESULTS Intestinal I/R and Caco-2 cell hypoxia/reoxygenation decreased the expression of PINK1 and p-DRP1 Ser637.Pretreatment with mdivi-1 inhibited mitochondrial fission,ROS generation,and apoptosis and ameliorated cell injury in intestinal I/R.Upon PINK1 knockdown or overexpression in vitro,we found that p-DRP1 Ser637 expression and DRP1 recruitment to the mitochondria were associated with PINK1.Furthermore,we verified the physical combination of PINK1 and p-DRP1 Ser637.CONCLUSION PINK1 is correlated with mitochondrial fission and apoptosis by regulating DRP1 phosphorylation in intestinal I/R.These results suggest that the PINK1/DRP1 pathway is involved in intestinal I/R injury,and provide a new approach for prevention and treatment.展开更多
Objective Keshan disease(KD)is a myocardial mitochondrial disease closely related to insufficient selenium(Se)and protein intake.PTEN induced putative kinase 1(PINK1)/Parkin mediated mitochondrial autophagy regulates ...Objective Keshan disease(KD)is a myocardial mitochondrial disease closely related to insufficient selenium(Se)and protein intake.PTEN induced putative kinase 1(PINK1)/Parkin mediated mitochondrial autophagy regulates various physiological and pathological processes in the body.This study aimed to elucidate the relationship between PINK1/Parkin-regulated mitochondrial autophagy and KD-related myocardial injury.Methods A low Se and low protein animal model was established.One hundred Wistar rats were randomly divided into 5 groups(control group,low Se group,low protein group,low Se+low protein group,and corn from KD area group).The JC-1 method was used to detect the mitochondrial membrane potential(MMP).ELISA was used to detect serum creatine kinase MB(CK-MB),cardiac troponin I(cTnI),and mitochondrial-glutamicoxalacetic transaminase(M-GOT)levels.RT-PCR and Western blot analysis were used to detect the expression of PINK1,Parkin,sequestome 1(P62),and microtubule-associated proteins1A/1B light chain 3B(MAP1LC3B).Results The MMP was significantly decreased and the activity of CK-MB,cTnI,and M-GOT significantly increased in each experimental group(low Se group,low protein group,low Se+low protein group and corn from KD area group)compared with the control group(P<0.05 for all).The mRNA and protein expression levels of PINK1,Parkin and MAP1LC3B were profoundly increased,and those of P62 markedly decreased in the experimental groups compared with the control group(P<0.05 for all).Conclusion Low Se and low protein levels exacerbate myocardial damage in KD by affecting the PINK1/Parkin-mediated mitochondrial autophagy pathway.展开更多
Background:Studies have reported mitophagy activation in renal tubular epithelial cells(RTECs)in acute kidney injury(AKI).Phosphatase and tensin homolog-induced putative kinase 1(PINK1)and E3 ubiquitin-protein ligase ...Background:Studies have reported mitophagy activation in renal tubular epithelial cells(RTECs)in acute kidney injury(AKI).Phosphatase and tensin homolog-induced putative kinase 1(PINK1)and E3 ubiquitin-protein ligase Parkin are involved in mitophagy regulation;however,little is known about the role of PINK1-Parkin mitophagy in septic AKI.Here we investigated whether the PINK1-Parkin mitophagy pathway is involved in septic AKI and its effects on cell apoptosis in vitro and on renal functions in vivo.Methods:Mitophagy-related gene expression was determined using Western blot assay in human RTEC cell line HK-2 stimulated with bacterial lipopolysaccharide(LPS)and in RTECs from septic AKI rats induced by cecal ligation and perforation(CLP).Autophagy-related ultrastructural features in rat RTECs were observed using electron microscopy.Gain-and loss-of-function approaches were performed to investigate the role of the PINK1-Parkin pathway in HK-2 cell mitophagy.Autophagy activators and inhibitors were used to assess the effects of mitophagy modulation on cell apoptosis in vitro and on renal functions in vivo.Results:LPS stimulation could significantly induce LC3-II and BECN-1 protein expression(LC3-II:1.72±0.05 vs.1.00±0.05,P<0.05;BECN-1:5.33±0.57 vs.1.00±0.14,P<0.05)at 4 h in vitro.Similarly,LC3-II,and BECN-1 protein levels were significantly increased and peaked at 2 h after CLP(LC3-II:3.33±0.12 vs.1.03±0.15,P<0.05;BECN-1:1.57±0.26 vs.1.02±0.11,P<0.05)in vivo compared with those after sham operation.Mitochondrial deformation and mitolysosome-mediated mitochondria clearance were observed in RTECs from septic rats.PINK1 knockdown significantly attenuated LC3-II protein expression(1.35±0.21 vs.2.38±0.22,P<0.05),whereas PINK1 overexpression markedly enhanced LC3-II protein expression(2.07±0.21 vs.1.29±0.19,P<0.05)compared with LPS-stimulated HK-2 cells.LPS-induced proapoptotic protein expression remained unchanged in autophagy activator-treated HK-2 cells and was significantly attenuated in PINK1-overexpressing cells,but was remarkably upregulated in autophagy inhibitor-treated and in PINK1-depleted cells.Consistent results were observed in flow cytometric apoptosis assay and in renal function indicators in rats.Conclusion:PINK1-Parkin-mediated mitophagy might play a protective role in septic AKI,serving as a potential therapeutic target for septic AKI.展开更多
基金the National Natural Science Foundation of China,No.81679154,No.81871547.
文摘BACKGROUND Intestinal ischemia reperfusion(I/R)occurs in various diseases,such as trauma and intestinal transplantation.Excessive reactive oxygen species(ROS)accumulation and subsequent apoptotic cell death in intestinal epithelia are important causes of I/R injury.PTEN-induced putative kinase 1(PINK1)and phosphorylation of dynamin-related protein 1(DRP1)are critical regulators of ROS and apoptosis.However,the correlation of PINK1 and DRP1 and their function in intestinal I/R injury have not been investigated.Thus,examining the PINK1/DRP1 pathway may help to identify a protective strategy and improve the patient prognosis.AIM To clarify the mechanism of the PINK1/DRP1 pathway in intestinal I/R injury.METHODS Male C57BL/6 mice were used to generate an intestinal I/R model via superior mesenteric artery occlusion followed by reperfusion.Chiu’s score was used to evaluate intestinal mucosa damage.The mitochondrial fission inhibitor mdivi-1 was administered by intraperitoneal injection.Caco-2 cells were incubated in vitro in hypoxia/reoxygenation conditions.Small interfering RNAs and overexpression plasmids were transfected to regulate PINK1 expression.The protein expression levels of PINK1,DRP1,p-DRP1 and cleaved caspase 3 were measured by Western blotting.Cell viability was evaluated using a Cell Counting Kit-8 assay and cell apoptosis was analyzed by TUNEL staining.Mitochondrial fission and ROS were tested by MitoTracker and MitoSOX respectively.RESULTS Intestinal I/R and Caco-2 cell hypoxia/reoxygenation decreased the expression of PINK1 and p-DRP1 Ser637.Pretreatment with mdivi-1 inhibited mitochondrial fission,ROS generation,and apoptosis and ameliorated cell injury in intestinal I/R.Upon PINK1 knockdown or overexpression in vitro,we found that p-DRP1 Ser637 expression and DRP1 recruitment to the mitochondria were associated with PINK1.Furthermore,we verified the physical combination of PINK1 and p-DRP1 Ser637.CONCLUSION PINK1 is correlated with mitochondrial fission and apoptosis by regulating DRP1 phosphorylation in intestinal I/R.These results suggest that the PINK1/DRP1 pathway is involved in intestinal I/R injury,and provide a new approach for prevention and treatment.
基金supported by the Natural Science Foundation of Heilongjiang Province(No.LH2021H009).
文摘Objective Keshan disease(KD)is a myocardial mitochondrial disease closely related to insufficient selenium(Se)and protein intake.PTEN induced putative kinase 1(PINK1)/Parkin mediated mitochondrial autophagy regulates various physiological and pathological processes in the body.This study aimed to elucidate the relationship between PINK1/Parkin-regulated mitochondrial autophagy and KD-related myocardial injury.Methods A low Se and low protein animal model was established.One hundred Wistar rats were randomly divided into 5 groups(control group,low Se group,low protein group,low Se+low protein group,and corn from KD area group).The JC-1 method was used to detect the mitochondrial membrane potential(MMP).ELISA was used to detect serum creatine kinase MB(CK-MB),cardiac troponin I(cTnI),and mitochondrial-glutamicoxalacetic transaminase(M-GOT)levels.RT-PCR and Western blot analysis were used to detect the expression of PINK1,Parkin,sequestome 1(P62),and microtubule-associated proteins1A/1B light chain 3B(MAP1LC3B).Results The MMP was significantly decreased and the activity of CK-MB,cTnI,and M-GOT significantly increased in each experimental group(low Se group,low protein group,low Se+low protein group and corn from KD area group)compared with the control group(P<0.05 for all).The mRNA and protein expression levels of PINK1,Parkin and MAP1LC3B were profoundly increased,and those of P62 markedly decreased in the experimental groups compared with the control group(P<0.05 for all).Conclusion Low Se and low protein levels exacerbate myocardial damage in KD by affecting the PINK1/Parkin-mediated mitochondrial autophagy pathway.
基金This work was supported by grants from the National Natural Science Foundation of China(Nos.81601708,81671960)the Natural Science Foundation of Hunan Province,China(No.2018JJ2014).
文摘Background:Studies have reported mitophagy activation in renal tubular epithelial cells(RTECs)in acute kidney injury(AKI).Phosphatase and tensin homolog-induced putative kinase 1(PINK1)and E3 ubiquitin-protein ligase Parkin are involved in mitophagy regulation;however,little is known about the role of PINK1-Parkin mitophagy in septic AKI.Here we investigated whether the PINK1-Parkin mitophagy pathway is involved in septic AKI and its effects on cell apoptosis in vitro and on renal functions in vivo.Methods:Mitophagy-related gene expression was determined using Western blot assay in human RTEC cell line HK-2 stimulated with bacterial lipopolysaccharide(LPS)and in RTECs from septic AKI rats induced by cecal ligation and perforation(CLP).Autophagy-related ultrastructural features in rat RTECs were observed using electron microscopy.Gain-and loss-of-function approaches were performed to investigate the role of the PINK1-Parkin pathway in HK-2 cell mitophagy.Autophagy activators and inhibitors were used to assess the effects of mitophagy modulation on cell apoptosis in vitro and on renal functions in vivo.Results:LPS stimulation could significantly induce LC3-II and BECN-1 protein expression(LC3-II:1.72±0.05 vs.1.00±0.05,P<0.05;BECN-1:5.33±0.57 vs.1.00±0.14,P<0.05)at 4 h in vitro.Similarly,LC3-II,and BECN-1 protein levels were significantly increased and peaked at 2 h after CLP(LC3-II:3.33±0.12 vs.1.03±0.15,P<0.05;BECN-1:1.57±0.26 vs.1.02±0.11,P<0.05)in vivo compared with those after sham operation.Mitochondrial deformation and mitolysosome-mediated mitochondria clearance were observed in RTECs from septic rats.PINK1 knockdown significantly attenuated LC3-II protein expression(1.35±0.21 vs.2.38±0.22,P<0.05),whereas PINK1 overexpression markedly enhanced LC3-II protein expression(2.07±0.21 vs.1.29±0.19,P<0.05)compared with LPS-stimulated HK-2 cells.LPS-induced proapoptotic protein expression remained unchanged in autophagy activator-treated HK-2 cells and was significantly attenuated in PINK1-overexpressing cells,but was remarkably upregulated in autophagy inhibitor-treated and in PINK1-depleted cells.Consistent results were observed in flow cytometric apoptosis assay and in renal function indicators in rats.Conclusion:PINK1-Parkin-mediated mitophagy might play a protective role in septic AKI,serving as a potential therapeutic target for septic AKI.
