Background:Osteoarthritis(OA)is a common degenerative joint disease character-ized by the progressive degradation of articular cartilage.Mitochondrial dysfunction and autophagy,including mitophagy,have been implicated...Background:Osteoarthritis(OA)is a common degenerative joint disease character-ized by the progressive degradation of articular cartilage.Mitochondrial dysfunction and autophagy,including mitophagy,have been implicated in OA pathogenesis.Long noncoding RNAs(lncRNA)are emerging as key regulators in various cellular pro-cesses,but their roles in OA,particularly in chondrocytes,remain poorly understood.This study explores the involvement of lncRNA-GCH1 in regulating mitophagy and its impact on chondrocyte function and cartilage degradation in OA.Methods:Primary chondrocytes were isolated from the cartilage tissues of OA pa-tients and healthy controls.lncRNA-GCH1 expression was assessed using RNA-seq,reverse transcription quantitative polymerase chain reaction,and RNA fluorescence in situ hybridization.Functional assays,including Cell Counting Kit-8(CCK-8),colony formation,flow cytometry,and Western blotting,were used to evaluate the effects of lncRNA-GCH1 knockdown on chondrocyte proliferation,apoptosis,cell cycle,and mi-tophagy.Mitochondrial function was assessed by measuring adenosine triphosphate production,reactive oxygen species levels,and mitochondrial membrane potential.In vivo,a murine OA model was used to examine the impact of lncRNA-GCH1 knock-down on cartilage degradation.Results:lncRNA-GCH1 was upregulated in OA chondrocytes and localized in the cy-toplasm.Knockdown of lncRNA-GCH1 enhanced cell proliferation and arrested cell cycle in G0/G1.It also suppressed mitophagy,improved mitochondrial function,and reduced matrix-degrading enzyme expression-effects that were reversed by rapa-mycin treatment.Meanwhile,lncRNA-GCH1 knockdown reduced PTEN-induced ki-nase 1(PINK1)aggregation and in vivo local inhibition of PINK1 diminished cartilage degradation.Conclusion:lncRNA-GCH1 regulates mitophagy in OA chondrocytes,influencing mi-tochondrial function and matrix degradation.Targeting lncRNA-GCH1 may offer a potential therapeutic approach for OA treatment.展开更多
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
基金Sun Yat-sen Memorial Hospital Clinical Research 5010 Program,Grant/Award Number:SYS-5010-202403Natural Science Foundation of Guangdong Province,Grant/Award Number:2024A1515012811+1 种基金Sun Yat-sen Scientific Research Project,Grant/Award Number:YXQH202202Guangdong Provincial Key Research and Development Program,Grant/Award Number:2023B1111050003。
文摘Background:Osteoarthritis(OA)is a common degenerative joint disease character-ized by the progressive degradation of articular cartilage.Mitochondrial dysfunction and autophagy,including mitophagy,have been implicated in OA pathogenesis.Long noncoding RNAs(lncRNA)are emerging as key regulators in various cellular pro-cesses,but their roles in OA,particularly in chondrocytes,remain poorly understood.This study explores the involvement of lncRNA-GCH1 in regulating mitophagy and its impact on chondrocyte function and cartilage degradation in OA.Methods:Primary chondrocytes were isolated from the cartilage tissues of OA pa-tients and healthy controls.lncRNA-GCH1 expression was assessed using RNA-seq,reverse transcription quantitative polymerase chain reaction,and RNA fluorescence in situ hybridization.Functional assays,including Cell Counting Kit-8(CCK-8),colony formation,flow cytometry,and Western blotting,were used to evaluate the effects of lncRNA-GCH1 knockdown on chondrocyte proliferation,apoptosis,cell cycle,and mi-tophagy.Mitochondrial function was assessed by measuring adenosine triphosphate production,reactive oxygen species levels,and mitochondrial membrane potential.In vivo,a murine OA model was used to examine the impact of lncRNA-GCH1 knock-down on cartilage degradation.Results:lncRNA-GCH1 was upregulated in OA chondrocytes and localized in the cy-toplasm.Knockdown of lncRNA-GCH1 enhanced cell proliferation and arrested cell cycle in G0/G1.It also suppressed mitophagy,improved mitochondrial function,and reduced matrix-degrading enzyme expression-effects that were reversed by rapa-mycin treatment.Meanwhile,lncRNA-GCH1 knockdown reduced PTEN-induced ki-nase 1(PINK1)aggregation and in vivo local inhibition of PINK1 diminished cartilage degradation.Conclusion:lncRNA-GCH1 regulates mitophagy in OA chondrocytes,influencing mi-tochondrial function and matrix degradation.Targeting lncRNA-GCH1 may offer a potential therapeutic approach for OA treatment.
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.
