Isolated Monoclonal Human Urine-Derived Stem Cells Showed Differential Therapeutic Effects on Renal Ischemia–Reperfusion Injury in Mice

<b>Objectives</b>: To investigate the characteristics of monoclonal human urine-derived stem cells (hUSCs) obtained through different culture protocols and compare their therapeutic effects on renal ischemia-reperfusion injury in mice. <b>Methods</b>: Monoclones of hUSCs derived from the urine of healthy volunteers were isolated and cultured using two different culture media. Flow cytometry, qRT-PCR and RNA sequencing were employed to characterize each monoclonal clone of multipotent stem cells across multiple passages. To evaluate their therapeutic effects on unilateral renal ischemia-reperfusion injury in BALB/c mice, 5 × 10⁵ hUSCs from each monoclonal clone were intravenously administered to mice via the tail vein, followed by assessments using Masson staining, qRT-PCR and renal tissue transcriptomics analysis. <b>Results</b>: Four monoclonal strains were successfully isolated from four fresh urine samples of a healthy young male volunteer: three cultured in EGM-MV medium and one in our modified medium. All four strains demonstrated stable expression of mesenchymal stem cell-related markers over eight passages of expansion. Bioinformatics analysis of multiple cell transcriptome datasets revealed that these four cell strains are more closely related to kidney tissue than to bone marrow mesenchymal stem cells (BMSCs), adipose-derived mesenchymal stem cells (ADMSCs), induced pluripotent stem cells (iPSCs), embryonic stem cells (ESCs), and urothelial cells. Additionally, significant differences were observed in the expression of genes associated with kidney development among the four monoclonal strains. Furthermore, the therapeutic effects of different monoclonal clones on renal ischemia-reperfusion injury in mice showed notable variability. <b>Conclusions</b>: The isolated monoclonal urine-derived stem cells in this study were showed closer transcriptomic similarity to renal progenitor cells than to other mesenchymal stem cell types and possessed differential therapeutic effects on acute kidney injury.