Diosgenin alleviates radiation nephropathy by suppressing renal mTORC1 signalling with concomitant effects on the gut...

Radiation nephropathy is a progressive inflammatory and fibrotic condition lacking effective therapies. The underlying cellular signalling mechanisms and their potential systemic involvement remain poorly defined.

We integrated single-cell transcriptomics, network pharmacology, molecular docking and dynamics simulations, and in vivo validation in a murine model of whole-body irradiation. RNA sequencing data from healthy and irradiated mouse kidneys were analyzed to map cell-type-specific signalling activities of mTORC1, endoplasmic reticulum (ER) stress, and inflammation, as well as intercellular communication. Mice received diosgenin at 30 or 100 mg/kg/d by orally or rapamycin at 2 mg/kg/d by intraperitoneal injection for 7 days before and 28 days after 5 Gy X-ray irradiation. Renal function, histopathology, oxidative stress, inflammatory cytokines, intestinal barrier integrity, hepatic inflammation, and gut microbiota were assessed.

Bulk transcriptomics and network pharmacology identified mTOR as a core target. Single-cell analysis revealed radiation-induced mTORC1 activation in proximal tubular cells and immune cells, coupled with ER stress and inflammation. Molecular docking predicted high binding affinity between diosgenin and mTOR. Molecular dynamics simulations confirmed stable diosgenin-mTOR binding over 100 ns. In vivo, diosgenin suppressed renal mTORC1 activity, reduced ER stress, and macrophage infiltration, lowered serum TNF-α, IL-1β, and IL-6, and decreased serum urea and creatinine by approximately 30.25% and 26.20%, respectively. Diosgenin alleviated renal fibrosis, restored colonic occludin expression by 1.5-fold, decreased hepatic F4/80-positive cells by 75.32%, reversed gut dysbiosis including suppression of Pseudomonadota, and these effects were similar to those of rapamycin, an mTOR inhibitor.

Diosgenin alleviates radiation nephropathy by suppressing mTORC1 signalling while exerting concomitant effects on the gut and liver. These findings establish a multi-omics and single-cell framework for radiation nephropathy and support diosgenin as a candidate for translational research.