Study On The Role Of PGC-1? And Related Transcription Factors In Diabetic Nephropathy And Kidney Aging

Objective: To investigate the functions and mechanisms of PGC-1?,a key mitochondrial regulatory gene,in diabetic nephropathy(DN),and to explore the relationship between C/EBP? and PGC-1? and its role in kidney aging.This study may provide the theoretical basis for the pathogenesis and intervention of DN.Methods: Firstly,DN mouse models were established based on db/db mice and confirmed by evaluating blood glucose,urine biochemical indices and pathological analysis of kidney,and some DN mice were treated with rosiglitazone,a PPAR? agonist.The western blot was used to confirm the change of PGC-1? expression and the effect of rosiglitazone on the renal impairment of DN.Quantitative PCR and western blot were used to evaluate the injury in mouse podocyte and mesangial cell lines treated by high glucose at concentrate of 30 m M,respectively;and after regulating PGC-1? genetically,the changes of reactive oxygen species(ROS)in mesangial cells were observed through DCFH-DA fluorescent probe.Subsequently,the renal cortex totel RNA of the above mouse models was sequenced and the roles of long non-coding RNAs(lnc RNAs)in DN were investigated by transcriptomic bioinformatic analysis and quantitative PCR.This study also built chronical kidney aging models based on glomerular podocyte / proximal tubular epithelial cellspecific C/EBP? knockout mice,using urine biochemical detection,histopathological analysis,western blot,quantitative PCR and immunohistochemistry to investigate the effects of C/EBP? on kidney aging and its mechanisms.PGC-1? was knockdown in mouse glomerular podocytes in vitro,and western blot was used to observe the effects of PGC-1?in this process.Results: Db/db mice at 14 weeks of age had increased proteinuria,podocyte injury,glomerulosclerosis,epithelial-mesenchymal transdifferentiation,increased expression of PGC-1? and reduced mitochondrial superoxide dismutase activity than normal controls.Administration of rosiglitazone increased the expression of PGC-1? in the nucleus of renal cortical cells and alleviated the DN lesion.In high glucose intervention of podocytes,PGC-1? m RNA was up-regulated at 24 h,and down-regulated at 48 h,and podocyte marker proteins decreased and mitochondrial electron transport complexes were inhibited;Furthermore,in high glucose intervention of mesangial cells,it was also observed that the expression of PGC-1? and autophagy-related protein LC3-II was decreased and ROS production was increased.Knockdown of PGC-1? showed significantly increased ROS level induced by high glucose.The expression of 198 lnc RNAs was significantly changed in DN mice compared with the normal controls,and rosiglitazone intervention restored the expression of 60 lnc RNAs.The differentially expressed m RNAs between DN mice and normal control mice were enriched in both metabolic and inflammation-related pathways.Additionally,when DN mice administrated rosiglitazone compared to untreated DN mice,while the differentially expressed m RNAs were mainly enriched in the inflammation-related pathways,the targeted genes of differential lnc RNAs were enriched more in the metabolic pathways.Glomerular podocyte-specific C/EBP? knockout aggravated podocyte injury and glomerulosclerosis in kidney aging mice,and at the same time,inhibited the autophagy activity,down-regulated the expression of klotho and PGC-1? pathway-related proteins;?-galactosidase accumulation was mainly in tubular epithelial cells when kidney aging,and proximal tubular epithelial cell-specific C/EBP? knockout aggravated its accumulation.Moreover,in podocytes of PGC-1? knockdown,the autophagic activity was also inhibited.Conclusion: PPAR? agonist rosiglitazone induces the expression of endogenous PGC-1?,and reduces the production of ROS and improves DN.Lnc RNAs play a role in mechanisms of occurrence and progression and protective effects of rosiglitazone in DN,and in the later process,lnc RNAs may be involved in the regulation of metabolic pathways.Podocyte-specific C/EBP? knockout aggravates autophagic inhibition,podocyte injury and glomerulosclerosis in renal cortex tissue of the aging mice,which may be related to the inhibition of klotho expression and PGC-1? associated pathways.