Protective Effect and Mechanism of Silencing HIF-1α in Hypoxia Injury

HIF-1α (Hypoxia-inducible factor-1α) is the most important physiological regulator in hypoxia. In this study, the differential expression of HIF-1α in Ischemic stroke (IS) or MCAO with rats and mice was analyzed by Gene Expression Omnibus (GEO) database. Glucose and oxygen deprivation (OGD) model was used to study the expression of HIF-1α in human cerebrovascular endothelial cells (HCMEC/D3), as well as the biological functions and pathways of HIF-1α-related genes, and the regulatory relationship between lncHIF1A-AS2/miR-27a-3p/HIF-1α related to HIF-1α. The relative contents of malondialdehyde (MDA) and reactive oxygen species (ROS) were discussed. The infection efficiency and the differential expression of HIF-1α were detected by qRT-PCR and Western Blot. CCK-8 assay to analyze the effect of HIF-1α silencing on cell proliferation; Chemiluminescence method and fluorescence probe method were used to detect the changes of MDA and ROS content respectively. The Search Tool for the Retrieval of Interaction Gene/Proteins (STRING) database was used to study genes related to HIF-1α, and to perform GO and KEGG pathway enrichment analysis. The DIANA-LncBase (v2) database and the miRTarBase database were used to determine the regulatory relationship between lncHIF1A-AS2/miR-27a-3p/HIF-1α. Finally, the lncRNA-miRNA-mRNA regulatory network was constructed by Cytoscape. And it was verified by dual luciferase reporter experiment. After HIF-1α silencing by lentivirus, it promoted the proliferation of HCMEC/D ₃ cells and reduced the content of MDA and ROS in cells. Bioinformatics analysis showed that the expression of HIF-1α was increased in the IS or MCAO group; Pathway analysis showed that HIF-1α is mainly involved in the response to changes in oxygen content and related biological functions and pathways such as HIF-1 signaling pathway. There is a regulatory relationship between HIF-1α and lncHIF1A-AS2/miR-27a-3p. In conclusion, the mechanism of silencing HIF-1α to protect hypoxic damage by reducing MDA and ROS content may be that HIF-1α regulates the expression of lncHIF1A-AS2/miR-27a-3p.