ASIV Attenuates Cisplatin-Induced Proximal Tubular Injury by Enhancing Mitochondrial Biogenesis and Mitophagy Through the ADRA1A/AMPK/FOXO3A Pathway.

Cisplatin causes nephrotoxicity by accumulating in renal tubular epithelial cells (RTECs). Astragaloside IV (ASIV) shows renoprotective potential, but its mechanisms remain poorly understood. Cisplatin induced nephrotoxicity was established in 8-week-old male C57BL/6 mice via intraperitoneal administration of cisplatin at 20 mg/kg for 48 h. For in vitro studies, HK-2 human proximal tubular epithelial cells were exposed to 50 μM cisplatin for 24 h. Multi-omics approaches were employed to identify novel mechanisms by which ASIV ameliorates cisplatin-induced proximal tubular injury. ASIV markedly reduced serum creatinine and urea nitrogen levels in mice, and ameliorated cisplatin-induced proximal tubular injury both in vivo and in vitro. Moreover, ASIV restored mitochondrial damage, upregulated protein expression of PGC-1α, TOMM20, and PINK1 in RTECs. Mechanistically, RNA-seq and scRNA-seq revealed that cisplatin predominantly affected ADRA1A-mediated mitochondrial biogenesis and mitophagy in proximal tubular cells, accompanied by suppression of the AMPK/FOXO3A pathway. Notably, ASIV upregulated ADRA1A expression, thereby facilitating AMPK and FOXO3A phosphorylation and consequently enhancing mitochondrial biogenesis and mitophagy. Furthermore, dabuzalgron (a selective ADRA1A agonist) recapitulated the protective effects of ASIV. In contrast, the renoprotective action of ASIV against cisplatin-induced proximal tubular injury was largely abrogated by the ADRA1A antagonist tamsulosin in vivo and by ADRA1A-specific siRNA in vitro. These findings identify ASIV as a highly promising renoprotective agent that upregulates ADRA1A expression and activates the AMPK/FOXO3A axis to enhance mitochondrial biogenesis and mitophagy, thereby counteracting cisplatin-induced proximal tubular injury.