Tirzepatide ameliorates cisplatin-induced acute kidney injury by restoring NAMPT/NAD + homeostasis and enhancing Pink1-Parkin-mediated mitophagy.

Mitochondrial dysfunction and insufficient mitophagy are central to cisplatin-induced acute kidney injury (AKI). Tirzepatide, a dual GLP‑1/GIP receptor agonist, exhibits reno-protective effects, but its mechanism related to mitochondrial homeostasis remains unclear. Here, we used metabolomics, in vivo mouse AKI model, and in vitro cisplatin-injured HK‑2 cells to explore the protective effects and underlying mechanisms. Tirzepatide pretreatment significantly alleviated renal dysfunction, tubular injury, and mitochondrial damage caused by cisplatin. Metabolomic analysis revealed that tirzepatide strongly regulated energy metabolism and autophagy , particularly NAD + homeostasis. Mechanistically, tirzepatide boosted NAD levels by nicotinamide phosphoribosyl transferase (NAMPT), the rate-limiting enzyme for NAD + synthesis , which in turn activating the Pink1-Parkin mitophagy pathway. Inhibition of autophagy or NAMPT abolished the mitochondrial and reno-protective effects of tirzepatide. Taken together, our findings demonstrate that tirzepatide protects against cisplatin‑induced AKI by enhancing NAMPT‑dependent NAD + restoration and promoting mitophagy, highlighting a promising therapeutic strategy for chemotherapy‑related nephrotoxicity.