Vasculogenic Regenerative Medicine Technology

University Of Pittsburgh At Pittsburgh, Pittsburgh PA

Investigators

Linked publications & trials

Abstract

Modified Project Summary/Abstract Section Vascular tissue engineering approaches based on endothelial cell conversion in vitro face the challenge of transplantation, acceptance and integration into the recipient vascular system. Regenerative medicine approaches to achieve in vivo vasculogenic reprograming may spare such challenges and must negotiate with the recipient site’s biological processes during inducible vasculogenesis (iV). In 2017, we reported on iV of skin in vivo using a nanotechnology-based TNT (tissue nanotransfection) bioengineering technology wherein three transcription factors EFF (TNTEFF) proved to be vasculogenic in vivo. TNTEFF markedly increased vascularization of ischemic tissue and has been reproduced in subsequent publications. We know that a state-change of skin fibroblasts to vasculogenic fibroblasts (VF) in vivo is what makes functional blood vessels that anastomose with the parent vasculature. VF may be viewed as a product of injury-inducible, TNT-responsive, adaptive physiological state change aimed at tissue repair. Mechanisms underlying iV caused by TNTEFF remain unknown. We hypothesize that specific skin fibroblast subset of the dermis enables iV in response to EFF. To test this, we have developed an inducible transgenic mouse to selectively overexpress EFF in COL1A2-producing dermal fibroblast in acutely wounded animals (Aim 1). To probe the mechanism of EFF-induced VF generation (Aim 2), we will test the hypothesis that EFF interacts with ten-eleven translocation (TET) methylcytosine dioxygenase enzymes to demethylate and increase transcription of endothelial genes in fibroblasts in a manner that permits overcoming of diabetes-induced methylation barriers. Aim 1. Test the significance of vasculogenic fibroblasts (VFEFF) in tissue repair as a function of targeted delivery and disease state. 1.1 Dermal fibroblast-specific delivery of EFF in vivo enhances VF generation and improves skin tissue perfusion and quality of wound healing. 1.2 The diabetic state blunts VF induction and is associated with diminished perfusion and delayed wound healing that is overcome by delivery of EFF to wound-edge (WE) tissue. Aim 2. Test the significance of TET enzymes in EFF induced VF state change. 2.1 Diminishing “endothelial gene” promoter methylation in fibroblasts is required for EFF induced VF formation. 2.2 TET2 activity is essential for demethylating EC signature gene promoters to induce VF in WE tissue. 2.3 TET deficiency presents a barrier to EFF induced VF state change in diabetic mice that is overcome with TET and EFF concurrent delivery. This work aims to develop novel bioengineered regenerative medicine based vasculogenic solutions.