Protective effects of urine-derived stem cells on adriamycin-induced podocyte apoptosis in chronic kidney disease

Podocyte injury and apoptosis are central drivers of progressive glomerular dysfunction in chronic kidney disease (CKD). Urine-derived stem cells (UDSCs) are kidney-proximal multipotent cells with reported renoprotective properties, but their effects on ADR (adriamycin)-induced podocyte apoptosis and the influence of dosing frequency remain incompletely defined. In vitro, conditionally immortalized human podocytes (CIHP-1) were exposed to ADR (dose–response 0.1–2.0 µM; time-course up to 48 h) was used for establishing podocyte apoptosis model. Human UDSCs were isolated from urine, expanded and characterized. Indirect transwell co-culture was performed for evaluating reno-protection effect of UDSCs. In vivo, BALB/c mice received 10 mg/kg ADR through intravenous (IV) injection on day 0; UDSCs (1× \(\:{10}⁶\) cells/mouse) were administered starting day 7 as either a single dose or three daily doses. Endpoints included urine albumin/creatinine ratio (ACR), histology, TEM, immunostaining, and renal bulk transcriptomics. ADR induced early NF-κB activation and NLRP3/IL-1β increase followed by p53 and caspase-3 activation in CIHP-1. UDSC transwell co-culture attenuated NF-κB, NLRP3, IL-1β and caspase-3 induction, reduced cytochrome-c release, and preserved nephrin expression and F-actin architecture. In vivo, ADR increased ACR and produced glomerular injury with foot-process effacement; both single and repeated UDSC dosing reduced ACR and ameliorated histologic damage. Repeated dosing produced broader transcriptomic suppression of ferroptosis, ribosome biogenesis, and senescence/SASP-associated pathways compared with a single dose. UDSCs attenuate ADR-induced podocyte inflammation and apoptosis and promote structural and functional renal recovery. Dosing frequency shapes transcriptomic responses, with repeated dosing inducing broader anti-senescence signatures. These findings support further mechanistic investigation and translational development of UDSC therapy for CKD.