Cordycepin attenuates diabetic nephropathy by dual-pathway activation of TFEB to restore autophagy and ameliorate podocyte injury.

Currently, effective therapeutic strategies to halt the irreversible decline of renal function in diabetic nephropathy (DN) are limited. This study aimed to investigate the renoprotective effects of Cordycepin (COR), a bioactive adenosine analog derived from Cordyceps militaris, in a mouse model of DN and to elucidate its underlying mechanisms. In a type II diabetic mouse model induced by a high-fat diet and streptozotocin, COR treatment attenuated hyperglycemia and renal dysfunction, ameliorated glomerular injury, and restored the expression of Nephrin, a critical slit-diaphragm protein in podocytes. In vitro, in palmitic acid (PA)-induced podocyte injury, COR treatment elevated cell viability and upregulated Nephrin expression dose-dependently. Mechanistically, COR restored impaired autophagic flux under diabetic conditions by improving autophagosome maturation, autophagosome-lysosome fusion, and lysosomal degradation, as demonstrated by the normalized profile of autophagy markers (LC3-II/I, p62, Beclin-1, LAMP1). This pro-autophagic activity was essential for its protection, which was abolished by 3-MA and enhanced by rapamycin. Subsequently, we identified transcription factor EB (TFEB) as the central mediator of COR's action. COR dually regulates TFEB through two synchronized pathways: it inhibits the mTORC1 axis to promote TFEB nuclear translocation and transcriptional activity, while simultaneously suppressing K48-linked polyubiquitination to prevent its proteasomal degradation, and enhancing its stability. TFEB was essential for restoring autophagic flux and podocyte integrity, with overexpression reversing and knockdown exacerbating PA‑induced injury. In summary, our findings demonstrate that COR alleviates DN by coordinately enhancing the activity and stability of TFEB. This work reveals a novel dual-targeting mechanism and proposes a promising therapeutic strategy for diabetic nephropathy.