ABSTRACT Cutaneous wounds represent a significant healthcare issue and since 1997, no treatment for chronic wounds has received FDA approval. Contributing to this treatment desert is the complexity of the wound healing process and the relatively understudied field of how these activities are dysregulated and exploited in chronic wounds and cellular transformation. Our previous work demonstrated that the cadherin, desmoglein 2 (Dsg2) is a pleiotropic protein that modulates mitogenic signaling and pro-migratory programming in both tumorigenesis and wound healing. We have shown that Dsg2 is down-regulated in chronic wounds and that constitutive overexpression of Dsg2 in the epidermis confers increased wound healing, hyperproliferation, and tumor development. Highlighting the contribution of altered keratinocyte dynamics to the pathology of many dermatological conditions including chronic wounds, psoriasis, and squamous cell carcinoma. Dsg2 is able to modulate keratinocyte activities such as proliferation and migration through its regulation of downstream signaling molecules including the pro-proliferative and migratory proteins: EGFR and c-Src. In addition to the modulation of proteins, our lab has also demonstrated that Dsg2 regulates the cellular and small extracellular vesicle (sEV) transcriptome. miRNAseq revealed that Dsg2 induced the dramatic depletion of miR-146a, which is a potent regulator of the inflammatory response and has been shown to potentially regulate 4469 genes, including the level of miR-155. Therefore, it was interesting to note the consequent increase of miR-155 in response to Dsg2 expression. Recently, we have focused on identifying the upstream regulators of Dsg2, and much to our surprise, miR-155 targets Dsg2, which should lead to its degradation, however, RNAseq of these same cells lead to the realization that the level of the lncRNA, Dsg2-AS1, was also increased. It is well established that lncRNAs can “sponge” miRNAs and inhibit the degradation of their targets. This led us to consider a novel regulatory mechanism whereby Dsg2-AS1 sponges miR-155, allowing for a dramatic increase in Dsg2 expression. Preliminary data demonstrates that this mechanism is at play during normal wound healing, as evidenced by the increase in Dsg2 expression after the concomitant increase of miR-155 and Dsg2-AS1 during wound repair. In this proposal, we hypothesize that the regulatory loop that controls Dsg2 expression is altered in chronic wounds such as in the context of diabetes, which results in perturbed keratinocyte activation and therefore ineffective wound closure. Thus, the goals of this proposal are to elucidate the Dsg2 regulatory network and its impact on keratinocyte proliferation and migration, and to demonstrate the ability of sEV- encapsulated RNA species that target this network as a way to stimulate keratinocyte activation in wound repair. The findings obtained from these studies will demonstrate the feasibility of sEVs as a ro...