Exploration of the renoprotective effect of Yi-Shen-Hua-Shi granules on db/db mice and the mechanism of podocyte apoptosis based on the GRP78/CHOP signaling pathway

Yanmo Cai¹Yunhua Liu¹Sitong Wang¹Ge Jin¹Zhou Kaidong¹Xin Zhou¹Xinxue Zhang¹Min Zhang^2*Zongjiang Zhao^1*

• ¹Beijing University of Chinese Medicine, Beijing, China
• ²Department of Nephrology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China

Objective: Yi-Shen-Hua-Shi (YSHS) granules are a widely utilized Chinese medicine formula for treating diabetic kidney disease (DKD). While their effectiveness in treating DKD is established, the precise regulatory mechanism remains unclear. We aimed to explore the potential targets and mechanisms of action of YSHS in delaying DKD progression through network pharmacology and experimental validation. Methods: Network pharmacology was employed to identify potential targets and signaling pathways of YSHS in treating DKD, hypothesized to be associated with endoplasmic reticulum stress and apoptosis, and these predictions were validated through animal and cellular experiments. Following a 12-week YSHS intervention in db/db mice, assessments were conducted on blood glucose, lipid levels, renal function indices (24-hour urinary protein, blood glucose, serum creatinine, blood urea and urinary albumin-to-creatinine ratio), and kidney pathology. Apoptosis in Mouse Podocyte Clone-5 (MPC-5) cells was assessed using TUNEL labeling. The expression levels of GRP78, PERK, p-PERK, CHOP, Bcl-2, Bax, and Nephrin proteins and mRNAs in mouse kidney tissues and MPC-5 cells were evaluated through immunohistochemistry, western blotting, and real-time PCR. Results: YSHS significantly improved the general status of db/db mice, with a significant reduction in body mass, renal function indices, total cholesterol, triglycerides, and low-density lipoprotein. Pathological staining showed reduced renal tissue damage in mice, and electron microscopy revealed reduced pedunculopontine fusion and basement membrane thickening. YSHS decreased GRP78, PERK, p-PERK, CHOP, and Bax protein and mRNA levels in renal tissues and MPC-5 cells (P < 0.05, P < 0.01), while increasing Nephrin protein and Bcl-2 mRNA expression (P < 0.05, P < 0.01). Conclusion: YSHS inhibited podocyte apoptosis, protected the glomerular filtration barrier, attenuated proteinuria, and improved renal function indices by activating the GRP78/CHOP signaling pathway in the kidneys and in vitro cultured podocytes of db/db mice.