Urothelial cell senescence is not linked with telomere shortening

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.

Correction to: Defined serum- and xeno-free cryopreservation of mesenchymal stem cells

In the original article, Fig. 1A was by mistakenly duplicated. The corrected image is provided in this correction article.

Fetal subcutaneous cells have potential for autologous tissue engineering

Major congenital malformations affect up to 3% of newborns. Infants with prenatally diagnosed soft tissue defects should benefit from having autologous tissue readily available for surgical implantation in the perinatal period. In this study, we investigate fetal subcutaneous cells as cellular source for tissue engineering. Fetal subcutaneous biopsies were collected from elective terminations at gestational Week 20-21. Cells were isolated, expanded, and characterized in vitro. To determine cell coverage, localization, viability, and proliferation in different constructs, the cells were seeded onto a matrix (small intestine submucosa) or in collagen gel with or without poly(ε-caprolactone) mesh and were kept in culture for up to 8 weeks before analysis. Angiogenesis was analysed through a tube-forming assay. Fetal subcutaneous cells could be expanded until 43 ± 3 population doublings, expressed mesenchymal markers, and readily differentiate into adipogenic and osteogenic lineages. The cells showed low adherence to small intestine submucosa and did not migrate deep into the matrix. However, in collagen gels, the cells migrated into the gel and proliferated with sustained viability for up to 8 weeks. The cells in the matrices expressed Ki67, CD73, and α-smooth muscle actin but not cytokeratin or CD31. Fetal cells derived from subcutaneous tissue demonstrated favourable characteristics for preparation of autologous tissue transplants before birth. Our study supports the theory that cells could be obtained from the fetus during pregnancy for tissue engineering purposes after birth. In a future clinical situation, autologous transplants could be used for reconstructive surgery in severe congenital malformations.