Gentiopicroside inhibits HMGCR/NF-κB pathway to alleviate renal fibrosis

Gentiopicroside (GSP) has been shown to effectively ameliorate renal fibrosis (RF), yet its underlying mechanisms are poorly characterized. This study investigates how GSP alleviates RF using RNA-seq and in vitro experiments. First, an RF cell model was established through TGF-β induced HK-2 cells. The therapeutic effect of GSP on RF was evaluated in vitro through CCK-8 and Transwell assays. RNA-seq was used to identify potential targets of GSP in treating RF, followed by PPI analysis, GO and KEGG enrichment analyses to explore the mechanisms of GSP in alleviating RF. Finally, the mechanisms were comprehensively validated in vitro, and a rescue experiment was conducted by overexpressing HMGCR in HK-2 cells. GSP inhibited TGF-β-induced HK-2 cell proliferation and migration and reduced Collagen I and α-SMA expression in vitro. Differential analysis of control vs. model groups revealed a total of 911 differentially expressed genes, including 374 downregulated and 537 upregulated genes. Of these, 225 genes were reversed after GSP treatment. PPI analysis indicated that HMGCR is the core target of GSP in alleviating RF, and molecular docking demonstrated a strong binding between GSP and HMGCR, which was further confirmed by CETSA. GO enrichment analysis revealed that the improvement of RF by GSP is closely related to biological processes such as cholesterol biosynthesis and metabolism. KEGG pathway enrichment analysis highlighted the significant roles of cholesterol metabolism and the NF-κB signaling pathway in GSP’s effect on RF. Western blot results confirmed that GSP significantly inhibited expression of HMGCR and activation of the NF-κB signaling pathway in TGF-β-induced HK-2 cells. This effect was significantly reversed upon overexpression of HMGCR, indicating that GSP exerts its anti-RF effects by downregulating HMGCR and inhibiting NF-κB pathway activation. This study confirms that GSP can inhibit the HMGCR/NF-κB pathway to protect against TGF-β-induced HK-2 cell injury, exhibiting favorable therapeutic potential for RF.