Shenyuan granules improve cellular senescence through Klotho-mediated p16/p21 signaling pathway in diabetic kidney disease.

CONTEXT: Shenyuan Granules (SYG), a traditional Chinese medicine preparation, are clinically used for treating chronic kidney diseases. However, the role of Klotho in modulating cellular senescence via the p16/p21 pathway and its involvement in the therapeutic effects of SYG in diabetic kidney disease (DKD) remains unclear. OBJECTIVE: This study investigated the regulatory effects of SYG on the Klotho gene and their mechanisms in alleviating cellular senescence in DKD. MATERIALS AND METHODS: Utilizing an adenine-induced DKD model in db/db mice and AGE-stimulated HK-2 cells, this research assessed renal tissue for cellular senescence and pathological changes. Techniques such as SA-β-Gal, HE, and PAS staining were employed to observe these changes. The study also measured the expression levels of senescence-associated and anti-aging markers including Klotho, cyclin-dependent kinase inhibitor 2A (p16), cyclin-dependent kinase inhibitor p21 (p21), plasminogen activator inhibitor-1. Quantification of senescent cells was performed using SA-β-Gal staining, while mRNA and protein expressions were analyzed using immunofluorescence, real-time PCR, and Western blotting. RESULTS: SYG treatment significantly improved renal function in db/db mice and alleviated histopathological lesions. SA-β-Gal staining demonstrated a marked decrease in senescent cell burden, while immunohistochemistry and Western blotting revealed downregulation of p16, p21, and PAI-1 and upregulation of Klotho expression (p < 0.05). In vitro, Klotho overexpression in AGE-stimulated HK-2 cells significantly suppressed senescence-associated markers and restored Lamin B1 expression. Similarly, treatment with SYG-containing serum effectively downregulated p16, p21, and PAI-1 while upregulating Klotho expression. These findings suggest that SYG attenuate renal cellular senescence by modulating the Klotho-mediated p16/p21 signaling pathway. DISCUSSION: This study highlights the potential of SYG to alleviate cellular senescence in DKD by targeting the Klotho-mediated p16/p21 pathway. These findings provide a foundation for developing senescence-focused therapies in chronic kidney disease management.