Monday July 01, 2019 from 07:30 to 09:00
Induced pluripotent stem cells as an alternative source of epithelial and mesenchymal cells for reconstruction of urological tissues by tissue engineering
Christophe Caneparo1, Stéphane Chabaud1, Geneviève Bernard1, Stéphane J. Bolduc1.
1Surgery, CHU de Québec-Université Laval Research Centre, Québec City, QC, Canada
CUA-Astellas research grant.
Introduction: To reduce complications resulting from enterocystoplasties, we generated a bladder mucosa model where bladder fibroblasts secrete and assemble their own scaffold. The uroepithelial cells (UC) seeded on this construct differentiate appropriately, creating a barrier function. Nevertheless, we used cells from healthy patients while tissue-specific primary cells may be absent or diseased in some patients. Moreover, taking a biopsy is an invasive process for patients, which could result in comorbidities. To circumvent these issues, induced pluripotent stem (iPS) cells could be an alternative cell source. iPS cells are differentiated somatic cells reprogrammed to acquire embryonic stem cell-like properties. The iPS cells can be indefinitely expanded, providing large amounts of cells able to differentiate into all lineages needed for tissue-engineered constructs.
Methods: Reprogrammed iPS obtained either from urine, blood, or skin samples, were treated for five days by a mixture in order to obtain definitive endoderm (DE) cells. The expression of markers of DE cells (Sox17 and FoxA2) was verified. Double-positive cells were then treated for six days with another mixture or with UC-conditioned medium (UCM) to induce the cells into UC progenitors. Expression and localization of K8/18 were then checked using 2D cultures. Reconstruction of 3D models was done to assess the potential of the induced cells.
Results: The Activin A/Wortmanin mix for five days provided the best results to obtain DE cells. The cells treated with UCM showed high similarity with the original UC culture and presented a high degree of differentiation on 3D models. The origin of the iPS did not impact the final result, but a larger number of cells were obtained when extracted from blood samples.
Conclusions: The iPS cells could be used to reconstruct human-derived 3D urological tissues by tissue engineering. Further studies, e.g., graft on animals, are needed to confirm the safety of the technique.