Abstract 20373: Inhibition of Glycogen Synthase Kinase-3β Amplifies β-catenin Signaling to Promote Dedifferentiation of Endothelial Cells to Improve Neovessel Formation
Rationale: Wnt signaling plays a key role in the development and the regeneration of neovessels, however, the underlying mechanisms of these processes are not clearly understood.
Goal: To elucidate the mechanism of dedifferentiation of venous endothelial cells (VECs) to arterial (A)ECs.
Methods and Results: Herein we demonstrate that 6-bromoindirubin-3'-oxime (BIO), an inhibitor of Glycogen Synthase Kinase (GSK)-3β elicits the stabilization and the nuclear accumulation of β-catenin, thereby its direct interaction with the transcription factor NANOG in the nucleus of ECs. In a ChiP experiment, NANOG protein bound to the NANOG-, BRACHYURY-, CD133- and VEGFR2-promoters in these cells. In a cell-based assay, BIO induced the activation of the NANOG-promoter-luciferase reporter system. Accordingly, stimulation of VECs with BIO increased Notch-1, Ephrin-B2 and Hey2 expressions, indicating dedifferentiation these cells to AECs. While NANOG-depletion decreased BIO-induced NOTCH-1 expression and neovascularization. BIO increased Matrigel plug neovessel formation in nude mice. Immunostaining of Matrigel plug sections prepared from these mice showed increased expression of Notch-1, Ephrin-B2 and Hey2, indicating dedifferentiation of a subset of VECs into AECs. In a mouse model of hind limb ischemia, BIO induced the incorporation of VECs into collateral neovessels as characterized by Ephrin-B2- and Hey2-positivities, and smooth muscle cell recruitment.
Summary: Thus, we show that a subset of mature VECs may retain the ability to dedifferentiate into AECs in vivo and suggest critical roles of GSK-3β inhibition in this process.
Author Disclosures: K.K. Wary: Research Grant; Modest; American Heart Association Grant-In-Aid to KKW. E.E. Kohler: Research Grant; Modest; American Heart Association Predoct Fellowship to EEK.
This research has received full or partial funding support from the American Heart Association
- © 2014 by American Heart Association, Inc.