The Mechanism Of LncRNA-Gm4419/P50/Caspase3 On Microglial Apoptosis Induced By High Glucose

Background Diabetes mellitus is a metabolic disorder syndrome characterized by hyperglycemia.In recent years,with the changes of people’s diet and lifestyle,the number of people with diabetes is increasing,and the complications of diabetes are increasing with the prolonged survival of diabetic patients.Diabetic encephalopathy is a central nervous system disease characterized by cognitive impairment caused by diabetes.The pathogenesis of diabetic encephalopathy is unclear.Some studies have shown that the pathogenesis of diabetic encephalopathy is related to the persistent inflammation caused by the secretion of a large number of pro-inflammatory factors secreted by microglia.As a resident immune cell of the nervous system,microglia can release pro-inflammatory factors,phagocytosis of damaged cells,and also secrete neurotoxic substances that lead to apoptosis of neurons and themselves.Therefore,it is very important to regulate the balance between microglia proliferation and apoptosis.BV-2 cell lis a cell line of microglia.It is not only highly purified,but also possesses the morphological,phenotypic and functional characteristics of primary microglia cells,making them relatively easy to be cultured.Apoptotic is a kind of programmed cell death controlled by gene.It is mainly accomplished by family of cysteine aspartate protease.Long non-coding RNA is a molecule with multiple biological information functions,which can participate in the process of material metabolism and chromosome modification.LncRNA-Gm4419 is a newly discovered LncRNA which can regulate the expression of NF-κ B in high glucose environment.NF-κ B can mediate cell apoptosis,but its effect on microglial apoptosis has not been reported clearly.Objective To investigate the molecular mechanism of LncRNA-Gm4419 / p50/caspase-3 signaling pathway in high glucose induced microglial cell apoptosis.Methods BV-2 cells were cultured on 25mmol/L and 50mmol/L medium with glucose concentration,and the proliferation rate of BV-2 cells was detected by MTT assay.The apoptotic rate was detected by Annexin V/PI flow kit and the expression of apoptosis-related protein was detected by RT-PCR,Q-PCR and Western Blot.BV-2 cells were cultured on high glucose medium with glucose concentration of 50mmol/L.On this basis,LncRNA-Gm4419 Inhibitor,LncRNA-Gm4419 Mimics,p50 Inhibitorand p50 Mimics were transfected into BV-2 cells.The expression of LncRNA-Gm4419,P50,Caspase3 and Bcl-2 was detected by RTPCR,Q-PCR and Western Blot,and apoptosis was detected by flow cytometry.Meanwhile,Diabetic mouse was constructed,and the expression of LncRNA-Gm4419,P50,Caspase3 and Bcl-2 was detected by RT-PCR,Q-PCR and Western Blot.Results The proliferation rate of BV-2 cells in high glucose group was significantly lower than that in normal group,and the apoptosis rate of BV-2 microglia in high glucose group was significantly higher than that in normal group.The expression of LncRNAGm4419,P50 and apoptosis-related protein Caspase3 in high glucose group was significantly increased.The expression of anti-apoptotic protein Bcl-2 was significantly decreased.The expression of LncRNA-Gm4419 and P50 in microglia of diabetic mice was increased,the expression of pro-apoptotic protein Caspase3 was increased,and the expression of apoptotic protein Bcl-2 was decreased.The apoptosis rate in LncRNA-Gm4419 Inhibitor group was significantly lower than that in Mock group,and the expression of apoptosis-related protein Caspase3 was significantly decreased,and the expression of apoptosis-related protein Bcl-2 was significantly increased.Compared with Mock group and LncRNA-Gm4419 Inhibitor group,the apoptosis rate in LncRNA-Gm4419 Mimics group was increased,and the expression of apoptosis-related protein Caspase3 was significantly increased,while the expression of anti-apoptotic protein Bcl-2 was significantly decreased in LncRNA-Gm4419 Mimics group.The apoptosis rate of P50 Inhibitor group was significantly lower than that of Mock group,and the expression of apoptosis-related protein Caspase3 was significantly decreased,and the expression of apoptosis-related protein Bcl-2 was significantly increased.Compared with Mock group and P50 Inhibitor group,the apoptosis rate in P50 Mimics group was increased,and the expression of apoptosis-related protein Caspase3 was significantly increased,while the expression of apoptotic protein Bcl-2 was significantly decreased in P50 Mimics group.After transfection with LncRNA-Gm4419 Inhibitor and Mimics,the expression of P50 in LncRNA-Gm4419 Inhibitor group was significantly lower than that in Mock group.Compared with Mock group and LncRNA-Gm4419 Inhibitor group,the expression of P50 in LncRNA-Gm4419 Mimics group was significantly higher than that in LncRNA-Gm4419 Mimics group.After P50 Inhibitor and Mimics transfection,the expression of LncRNAGm4419 in each group did not change significantly.Conclusions High glucose can induce the apoptosis of microglia through LncRNAGm4419/P50/Caspase3 signaling pathway,that is,high glucose can promote the expression of LncRNA-Gm4419,thus up-regulate the expression of P50,and then promote the expression of Caspase3 to induce the apoptosis of microglia.