6-Hydroxygenistein Ameliorates High Altitude Brain Injury via Activating PI3K/AKT Signaling Pathway Based on Transcriptomic Analysis and Experimental Validation.

PURPOSE: Our Prior research has shown that 6-hydroxygenistein (6-OHG) alleviates hypobaric hypoxia induced brain injury (HHBI) achieved by its powerful antioxidant, anti-inflammatory, and anti-apoptotic capabilities, but its mechanism still requires additional investigation. The objective of this study was to uncover the protective mechanism of 6-OHG against HHBI based on transcriptomics analysis and experimental validation. METHODS: The gene levels in brain tissue obtained from previous study were accessed via the RNA-Seq technique. DESeq2 R package was used to identify the differentially expressed genes (DEGs). Functional enrichment analysis and molecular docking were investigated utilizing the clusterProfiler R package and Autodock Vina software, respectively. In experimental validation stage, histological analysis was performed using Hematoxylin-Eosin (HE) staining. Oxidative stress, inflammatory, and apoptotic indexes in brain tissue were measured using commercial kits. Western blot was applied for detecting related protein expression. RESULTS: The RNA-Seq analysis revealed 905 differentially expressed genes (DEGs) between the Con and Mod groups, with 239 upregulated and 666 downregulated. Between the 6-OHG and Mod groups, there were 192 DEGs, including 98 upregulated and 94 downregulated genes. Go and KEGG function analyses highlighted the PI3K/AKT signaling pathway as a crucial regulatory mechanism. Western blot analysis showed that HH exposure caused a decrease in the ratios of p-PI3K/PI3K and p-AKT/AKT in the mouse brain, but this effect was reversed by 6-OHG treatment, indicating that 6-OHG activates the PI3K/AKT signaling pathway. Furthermore, LY294002, a selective PI3K inhibitor, effectively blocked this activation and also abolished the protective effects of 6-OHG on histopathological damage, as well as its antioxidant, anti-inflammatory, and anti-apoptotic activities in HHBI mice. CONCLUSION: 6-OHG mitigates HHBI by activating the PI3K/AKT signaling pathway, suggesting its potential therapeutic application for HHBI treatment.