LAUSR

The success of regenerative medicine relies in part on the quality of the cells implanted. Cell cultures from cells isolated from bladder washes have been successfully established, but molecular changes and cell characteristics have not been explored in detail. In this work, we analysed the role of telomere shortening in relation to the regenerative potential and senescence of cells isolated from bladder washes and expanded in culture. We also analysed whether bladder washes would be a potential source for attaining stem cells or promoting stem cell proliferation by using two different substrates to support their growth: a feeder layer of growth‐arrested murine fibroblasts J2 3T3 cells and a xeno‐free human recombinant laminin‐coated surface. We found no association between telomere shortening and senescence in urothelial cells in vitro. Urothelial cells had a stable telomere length and expressed mesenchymal stem cells markers but failed to differentiate into bone or adipocytes. Feeder layer showed an advantage to laminin‐coated surfaces in respect to proliferative capacity with the expense of risking that feeder layer cells could persist in later passages. This emphasizes the importance of using carefully controlled culture conditions and molecular quality controls before autotransplantation in future clinical settings. In conclusion, urothelial cells isolated by bladder washes show regenerative potential that need further understanding. Senescence in vitro might be due to cellular stress, and if so, further improvements in culture conditions may lead to longer cell life and higher proliferative capacity.