TWIST1-reprogrammed endothelial cell transplantation potentiates neovascularization-mediated diabetic wound tissue regeneration

Hypo-vascularised diabetic non-healing wounds are due to reduced number and impaired physiology of endogenous endothelial progenitor cell (EPC) population that, limits their recruitment and mobilization at the wound site. To enrich the EPC repertoire from non-endothelial precursors, abundantly available mesenchymal stromal cells (MSCs) were reprogrammed into induced-endothelial cells (iECs). We identified cell signaling molecular targets by meta-analysis of microarray datasets. BMP-2 induction leads to the expression of inhibitory Smad 6/7-dependent negative transcriptional regulation of ID1, rendering the latter's reduced binding to TWIST1 during transdifferentiation of WJ-MSC into iEC. TWIST1, in turn, regulates endothelial genes transcription, positively of pro-angiogenic-KDR and negatively, in part, of anti-angiogenic-SFRP4. Twist1 reprogramming enhanced the endothelial lineage commitment of WJ-MSC, increased the vasculogenic potential of reprogrammed EC (rEC). Transplantation of stable TWIST1-rECs into full-thickness type 1 and 2 diabetic-splinted wound healing murine model enhanced the microcirculatory blood flow and accelerated the wound tissue regeneration. An increased or decreased co-localization of GFP with KDR/SFRP4 and CD31 in the regenerated diabetic wound bed with TWIST1 overexpression or silencing (piLenti-TWIST1-shRNA-GFP), respectively further confirmed improved neovascularization. This study depicted the reprogramming of WJ-MSCs into rECs using unique transcription factors, TWIST1 for an efficacious cell transplantation therapy to induce neovascularization–mediated diabetic wound tissue regeneration.