Wogonoside Attenuates Hypertension-Induced Renal Injury Through Modulation of the MAPK Signaling Pathway: A Mechanism Study

Abstract

To investigate the potential therapeutic effects, targets, and pathways of wogonoside in hypertension-induced renal injury using the Gene Expression Omnibus (GEO) database and network pharmacology, and to validate the effects of wogonoside intervention on the renal tissues of spontaneously hypertensive rats (SHR), angiotensin Ⅱ (Ang Ⅱ)-stimulated NRK-52E cell apoptosis, and the regulation of relevant pathways through in vivo and in vitro experiments.

Methods  GEO dataset and network pharmacology analyses were performed to investigate the key therapeutic targets of wogonoside for hypertensive nephropathy. The STRING database was used to analyze protein-protein interactions. Biological functions were annotated via Gene Ontology (GO), and the potential signaling pathways were enriched using the Kyoto Encyclopedia of Genes and Genomes (KEGG). SHR were randomly divided into groups and given low, medium, or high doses of wogonoside (0.075, 0.75, and 7.5 mg/kg) via gastric gavage for 10 weeks. Morphological changes in the kidney tissue were assessed by hematoxylin-eosin (HE) staining. Serum levels of inflammatory cytokines, including tumor necrosis factor α (TNF-α), interleukin (IL)-1β, and IL-6, were measured using ELISA. Apoptosis rates were evaluated by TUNEL staining, and Western blot was performed to determine the expression of Bax, Bcl-2, cleaved caspase-3, and caspase-3, and the expression of phosphorylated and total extracellular signal-regulated kinases (ERK) and p38 mitogen-activated protein kinase (MAPK) proteins. An in vitro model of Ang Ⅱ-stimulated NRK-52E cells was constructed and was treated with wogonoside at different concentrations (25, 50, or 100 μmol/L) for 24 h. The apoptosis rates were then assessed by Annexin V staining, and Western blot was performed to validate the expression of apoptosis-related and pathway-associated proteins.

Results Analysis of dataset GSE41453 revealed 11673 upregulated and 5902 downregulated genes in the renal tissues of SHR compared to the Wistar Kyoto (WKY) rats, or the WKY control group. Through the analysis of multiple databases, 371 potential targets of wogonoside were identified, resulting in 98 overlapping targets. From these, 45 core therapeutic targets were identified through further analysis, including TNF, CASP3, etc. GO analysis significantly enriched processes such as the negative regulation of apoptosis. KEGG pathway enrichment analysis highlighted the apoptosis pathway, IL-17 signaling pathway, and MAPK signaling pathway as being significantly enriched. Wogonoside treatment effectively mitigated pathological damage in SHR kidney tissues and significantly inhibited the expression of inflammatory cytokines, including TNF-α, IL-1β, and IL-6 (P < 0.05). It also decreased cell apoptosis rates in SHR kidney tissues and Ang Ⅱ-stimulated NRK-52E cells, downregulated the expression of Bax and cleaved caspase-3, and upregulated Bcl-2 expression (P < 0.05). Furthermore, wogonoside treatment inhibited the phosphorylation of ERK and p38 MAPK in SHR kidney tissues and Ang Ⅱ-stimulated NRK-52E cells (P < 0.05).

Conclusion Wogonoside may exert its protective effects against hypertension-induced renal injury by suppressing the inflammatory response and cell apoptosis, potentially through the regulation of the MAPK signaling pathway.

Keywords: Gene Expression Omnibus, Network pharmacology, Wogonoside, Hypertensive nephropathy, Apoptosis