Paper Title
Effect of Pooled Human Platelet LYSATE on Adipose-Derived Stem Cells Differentiation to Urothelial Cells

Background: Congenital abnormalities, cancer as well as injury could cause irreversible damage to the urinary tract which eventually requires organ reconstruction. Bladder, ureter and urethral tissue engineering involves seeding decellulrized matrix with urothelial and smooth muscle cells. However in cancer patients this approach risks cancer recurrence since there is no way to make sure that the seeded cells are not transformed. Mesenchymal stem cells (MSCs) with their mutilineage differentiation potential, hypo-immunogenicity and immunosuppressive effect in case of allogenic transplantation, along with the fact that they could be isolated either non-invasively from urine and breastmilk and with minimally invasive procedures from adipose tissue and bone marrow make them the most favorable choice for tissue engineering and cell based therapy. Pooled human platelet lysate (pHPL) is a source rich in growth factors that has been studied extensively on the expansion and differentiation of MSCs to osteogenic, adipogenic and chondrogenic phenotype. In this study, the effect of pHPL on the proliferation and differentiation of human adipose derived stem cells into urothelium was analyzed. Materials and Methods: Adipose stem cells (ASCs) were isolated from healthy individuals, characterized by means of cell surface markers and multilineage differentiation capability, using flow cytometry, osteogenic and adipogenic differentiation. The ASCs were induced using both conditioned media (CM) and keratinocyte serum free medium (KSFM) for 14 days. Protein and mRNA expression of the urothelium markers uroplakin-2 (UP-2) and cytokeratin-18 (K-18) were detected by immunofluorescence and quantitative real-time PCR, respectively. Results: The ASCs expanded with pHPL had a small compact morphology and demonstrated higher population doublings and cell yield compared with control FBS expanded cultures. The adipose-derived stem cells have the potential to be differentiated into urothelium-like cells in vitro using pHPL as serum replacement. However, the ease of isolation and the higher differentiation capability in terms of UP-2 and K-18 expression make them the most suitable choice for lower urinary tract tissue engineering.