RÉSUMÉ
The risk of aberrant growth of induced pluripotent stem cell (iPSC)-derived cells in response to DNA damage is a potential concern as the tumor suppressor genes TP53 and CDKN2A are transiently inactivated during reprogramming. Herein, we evaluate the integrity of cellular senescence pathways and DNA double-strand break (DSB) repair in Sendai virus reprogrammed iPSC-derived human fibroblasts (i-HF) compared to their parental skin fibroblasts (HF). Using transcriptomics analysis and a variety of functional assays, we show that the capacity of i-HF to enter senescence and repair DSB is not compromised after damage induced by ionizing radiation (IR) or the overexpression of H-RASV12. Still, i-HF lines are transcriptionally different from their parental lines, showing enhanced metabolic activity and higher expression of p53-related effector genes. As a result, i-HF lines generally exhibit increased sensitivity to various stresses, have an elevated senescence-associated secretory phenotype (SASP), and cannot be immortalized unless p53 expression is knocked down. In conclusion, while our results suggest that i-HF are not at a greater risk of transformation, their overall hyperactivation of senescence pathways may impede their function as a cell therapy product.
Sujet(s)
Vieillissement de la cellule , Fibroblastes , Cellules souches pluripotentes induites , Humains , Fibroblastes/métabolisme , Cellules souches pluripotentes induites/métabolisme , Protéine p53 suppresseur de tumeur/métabolisme , Réparation de l'ADN , Cassures double-brin de l'ADN , Stress physiologique , Reprogrammation cellulaire , Rayonnement ionisantRÉSUMÉ
This report demonstrates the successful deployment of MitraClip with the use of high frequency jet ventilation to stabilize the surgical field in a technically challenging case.