The potential application of urine derived stem cells in male infertility

Urine derived cells can be obtained non-invasively and may represent a potentially significantsource of autologous cells for tissue engineering. One goal of this study was to test the hypothesis that the cell population obtained from urine contains cells that meet the defining criteria of stem cells (self-renewal and multipotency). In particular, the ability of these cells to give rise to induced pluripotent stem cells(iPS) for the potential sperm progenitor cells generation was tested. Human urine derived cells were characterized and induced into iPS. Human urine derived cells from 9 individual donors (ages 5 to 40 years) were plated on multi-well plates. Single cell growth was monitored using time-lapse microcinematography. The cells were analyzed for expression of canonical reprogramming factors and pericytes/mesenchymal stem cell (MSC) markers. Expression of telomerase in the isolated cells was assessed by ELISA. Next, urine derived cells were cultured in various induction media for 21 days and assessed for evidence of differentiation into various cell types, including adipocytes, osteocytes, chondrocytes, SMC, and UC. USCs was induced into iPS by polycistronic lentiviral vector encoding human Oct-3/4, Sox2, Klf4 and c-Myc (OSKM). Some urine derived cells grew rapidly from a single cell clone for over 25 population doublings. Six of seven independent clones of urine derived cells expressed detectable levels of telomerase. USCs express the canonical reprogramming factors c-myc and klf4, and positive for pericytes/MSC markers such as CD146, NG2 and PDGF-receptor beta. When placed in appropriate induction media, these cells differentiated towards adipogenic, osteogenic and chrondrogenic lineages. Pluripotency of urine-derived iPSC clones was confirmed by immunocytochemistry, RT-PCR and teratoma formation. Urine-derived cells expressed the phenotypic features of pericytes/ MSC, including self-renewal and multipotency. One urine-derived cell clone can differentiate to multiple cell lineages. These results demonstrate the the feasibility of generating iPS from a urine sample and that urine-derived iPS might be further exploited for potential sperm progenitor cells generation study.