Expression Profile Of MiRNAs In Hippocampus Of CIH Rats And The Effect Of MiR-10a-5p Regulating PC12 Cell Apoptosis Under Intermittent Hypoxia

Objective: Obstructive sleep apnea syndrome(OSAS)has become an increasingly common public health problem.Neurocognitive impairment is one of the main consequences of OSAS.However,the specific pathogenesis of cognitive impairment caused by OSAS is still unclear.In this study,we established the expression profile of mi RNAs in hippocampus of chronic intermittent hypoxia(CIH)rats to explore the mechanism of key mi RNAs involved in cognitive impairment caused by CIH,and to provide a new treatment idea for cognitive impairment caused by OSAS.Methods: The cognitive impairment model of CIH rats was established.High throughput sequencing was used to screen mi RNAs in the hippocampus of CIH rats.QPCR was used to verify the differentially expressed mi RNAs and predict the target genes of differentially expressed mi RNAs.GO and KEGG were analyzed by bioinformatics technology.The combination of mi R-10a-5p and TRIM2 was verified by double luciferase assay;CCK-8 was used to explore the time of intermittent hypoxia.Immunofluorescence was used to detect the colocalization of TRIM2 and Bim.mi R-10a-5p mimics and inhibitors were transfected with liposomes to interfere with the expression of mi R-10a-5p.Hoechst33324 and TUNEL staining were used to detect the apoptosis.The protein levels of TRIM2,Bim and Bcl-2 were detected by WB method,and the ratio of Bim/ Bcl-2 was calculated.Results:1.In Morris water maze test,the escape latency of IH2 W and CIH4 W rats was significantly prolonged,and the number of crossing platform was significantly reduced.2.A total of 671 mi RNAs were found to be expressed in rat hippocampus by high-throughput sequencing.The results of differential expression analysis of high-throughput sequencing data of mi RNAs in hippocampus of CIH rats showed that there were 30 differentially expressed mi RNAs in IH1 W group compared with normal group,of which 22 were up-regulated and 8 were down regulated;There were 18 differentially expressed mi RNAs in IH2 W group compared with IH1 W group,of which 4 were up-regulated and 14 were down regulated;There were 16 differentially expressed mi RNAs in CIH4 W group compared with IH2 W group,among which 12 were up-regulated and 4 were down regulated;3.The expression of mi R-10a-5p was down regulated and mi R-6321 and mi R-3560 were up-regulated in the hippocampus of CIH rats.There was no significant difference between mi R-107-3p and mi R-292-3p.The results of q PCR were basically consistent with the sequencing data.4.GO analysis of differentially expressed mi RNAs predicted target genes in the hippocampus of CIH rats showed that the differentially expressed mi RNAs target genes in the hippocampus of IH1 W,IH2W and CIH4 W groups were mainly located in the cytoplasm,neuronal soma,synapses,mitochondria,dendrites and other cellular components at the cellular component level;The target genes of differentially expressed mi RNAs in IH1 W,IH2W and CIH4 W groups were mainly enriched in protein connection,transferase activity,nucleoside connection,kinase activity and ATP connection;The differentially expressed mi RNAs in IH1 W,IH2W and CIH4 W groups are involved in biological processes,mainly in protein phosphorylation,ion transport,nervous system development,apoptosis and protein ubiquitination.Compared with IH1 W group,with the prolongation of intermittent hypoxia,the differential expression of mi RNAs target genes in IH2 W group and CIH4 W group became more and more significant in cell apoptosis,protein ubiquitination and other biological processes.5.KEGG pathway enrichment analysis showed that the differentially expressed mi RNAs predicted target genes were mainly enriched in the metabolic pathway in the hippocampus of rats after 1 and 2 weeks of intermittent hypoxia,while they were mainly enriched in the axon guidance and protein ubiquitination pathway after 4weeks of intermittent hypoxia.6.The expression of TRIM2 protein is up-regulated in the hippocampus of CIH rats.mi R-10a-5p can bind to TRIM2 and affect the expression of TRIM2 protein.After the expression of mi R-10a-5p was up-regulated,the expression of TRIM2 was down regulated,the expression of Bim protein was up-regulated,the ratio of BIM / Bcl-2was increased,and the apoptosis of PC12 cells was increased;After inhibiting the expression of mi R-10a-5p,the expression of TRIM2 was up-regulated,the expression of Bim protein was down regulated,the ratio of BIM / Bcl-2 was decreased,and the apoptosis was reduced.Conclusion:1.Intermittent hypoxia may be involved in the occurrence and development of cognitive impairment in CIH rats by regulating axon guidance,protein ubiquitination and apoptosis pathway.2.Inhibiting the expression of mi R-10a-5p can reduce the apoptosis of PC12 cells under intermittent hypoxia.