Effects Of Resveratrol On Podocyte Apoptosis Induced By Mitochondrial Oxidative Stress Damage In High Glucose State Via SIRT1/PGC-1α

Objective:1.In vivo animal experiments indicate that apoptosis induced by mitochondrial oxidative stress injury induced by high sugar can damage the structure and function of renal podocyte.2.It was found by animal experiments in vivo that mitochondrial damage caused by increase of reactive oxygen species(ROS)is an important link to initiate apoptosis mechanism.3.The relative expression of silent information regulator 1(SIRT1)and peroxisome proliferator activated receptor γ coactivator-1 alpha(PGC-1a)in renal tissues of rats of each group was monitored in vivo,which confirmed that the SIRT1/PGC-1a protein pathway can regulate the expression of ROS.4.In vivo animal experiments have demonstrated that resveratrol can reduce oxidative stress injury of podocyte and protect kidneys by activating SIRT1/PGC-1a signaling pathway.Methods:1.Animal model and grouping: type 2 diabetes rat model was established by high-sugar and high-fat diet combined with low-dose streptozotocin intraperitoneal injection,and the successfully modeled rats were divided into diabetes model group and resveratrol treatment group.Normal group and model group were given carboxymethyl cellulose sodium equal volume daily gavage,resveratrol group was given 20mg/kg resveratrol preparation dissolved in carboxymethyl cellulose sodium gavage intervention.2.Renal function evaluation: At the end of 10 weeks of intervention,24 hours of urine was collected,abdominal aorta blood and both kidneys were collected,and kidney weights were weighed.The CBB assay kit was used to detect 24-hour urine protein(24h Upro),and the automatic biochemical apparatus was used to detect Blood creatinine(Scr)and Blood urea nitrogen(BUN).3.Evaluation of renal pathological morph ology and podocytes injury:General morphological changes of renal tissues were observed by HE staining,and extracellular matrix and renal fibrosis were observed by PAS and Masson staining.The ultrastructure of podocyte,podocyte mitochondria and glomeru lar basement membrane were observed by projective electron microscopy.Immunohistochemistry and western blot were used to detect Synaptopodin protein localization and expression level,and immunohistochemistry was used to detect Desmin protein level to assess podocyte injury.4.Protein expression and apoptosis evaluation of SIRT1 and PGC-1a in kidney tissues: the protein expression of SIRT1,PGC-1a,Bcl-2,Caspase9 and Caspase3 in kidney tissues was detected by immunohistochemistry.The protein expressions of SIRT1,PGC-1a and Caspase3 were detected by western blotting.Results:1.Effects of resveratrol on renal function of SD rats: Compared with normal group,Scr,BUN and 24 h Upro in model group were significantly increased(p<0.05).Compared with model group,Scr,BUN and 24 h Upro in resveratrol group were decreased(p<0.05).2.Effects of resveratrol on renal pathological morphology and podocytes injury in SD rats:(1)Pathological morphological changes: compared with normal group,glomerular hypertrophy and extensive proliferation of mesangial cells and mesangial matrix were found in model group.The above lesions were improved in resveratrol group.(2)Ultrastructural observation: normal group rats had uniform basement membrane thickness,regular shape of foot processes,full morphology of mitochondria,and clear arrangement of crest structures,while model group rats had uneven thickening of basement membrane,fusion and abscission of foot processes,swelling of mitochondria,thin matrix,and disorder of crest.The resveratrol group improved after 10 weeks of intervention.(3)Protein expression of Desmin and Sypaptopodin:Compared with the normal group,the expression of Desmin in the model group was increased by immunohistochemistry(P <0.05),and that of Sypaptopodin was decreased by immunohistochemistry and western blot(P <0.05).Compared with model group,Desmin expression in resveratrol group was decreased(P <0.05)and Sypaptopodin expression was increased(P <0.05).3.The inhibitory effect of resveratrol on SIRT1,PGC-1α protein expression and apoptosis in kidney of SD rats: Compared with normal group,the immunohistochemical and western blot levels of SIRT1 and pgc-1 α in model group were significantly decreased(p<0.05),the immunohistochemical and western blot levels of bcl-2 protein were decreased,the immunohistochemical and western blot levels of Caspase9 and Caspase3 were increased(p<0.05).Compared with model group,the expressions of SIRT1 and PGC-1α in resveratrol group were increased(P<0.05),the expressions of Bcl-2 protein were increased,and the expressions of Caspase9 and Caspase3 were decreased(P <0.05).Conclusion:There is significant mitochondrial oxidative stress damage in diabetic nephropathy rats.Resveratrol can reduce podocytes apoptosis under high glucose state,which may be related to the up-regulation of SIRT1/PGC-1αexpression to improve mitochondrial function and reduce ROS production.