Abstract 386: 6-bomoindirubin-3’-oxime Induces Dedifferentiation of Endothelial Cells During Neovascularization

Abstract

RATIONALE: Endothelial cell (EC) de-differentiation is a major challenge to understanding neovascularization and regenerative medicine. Rapid re-entry into the cell cycle, asymmetric cell division (ACD), and migratory phenotypes are considered hallmarks of cellular de-differentiation. The ability to induce de-differentiation of resident cells at the site of injury or ischemic tissues may be a useful approach for reparative and regenerative medicine. GOAL: To test the capacity of 6-bromoindirubin-3’-oxime (BIO), an inhibitor of GSK-3β, to induce neovascularization by stimulating a transcriptional program centering the NANOG gene networks in ECs. RESULTS: We show that BIO not only induced the interaction of β-catenin with NANOG, but also increased the expression of mesenchymal and hemangioblastic cell markers NANOG, VEGFR2, BRACHYURY , and CD133, while decreasing mature EC markers von Willebrand Factor ( v WF) and PECAM-1 (CD31). Increased expression of the NANOG transcriptional network induced characteristics of mesenchymal/stem-like cellular behavior in a hanging drop assay and increased robust neovascularization in vitro and in vivo . Furthermore, microscopic analyses indicated the ability of BIO to induce ACD in these cells, a hallmark of stem cell self-renewal. In contrast, NANOG- knockdown inhibited the ability of BIO treated ECs to divide asymmetrically, to form cellular aggregates, and to undergo angiogenesis. CONCLUSION: These findings highlight the capacity of BIO to induce dedifferentiation of ECs into “stem-like“ cells by up-regulating the expression of NANOG and NANOG gene networks. Thus, we propose that BIO could become useful not only for inducing neovascularization of ischemic tissues in situ , but also for generating a large number of cells for transplantation and regenerative medicine.