S13-04 The vascular wall as a source of stem cells in adult organs

naling events that are continuously modified by environmental cues. However, the details of how these processes can change cell fate choices are still unknown. Previously, we demonstrated that sustained expression of HOXA3 both accelerated wound healing and promoted neovascularisation in diabetic mice. We have subsequently shown that in response to injury HOXA3 induces a significant increase in both mobilization and recruitment of endothelial progenitor cells. In addition, HOXA3-treated mice have significantly fewer inflammatory cells recruited to the wound compared to control mice. Microarray analyses of HOXA3-treated wounds revealed that indeed HOXA3 locally increased expression of genes that selectively promote stem/progenitor cell mobilization and recruitment while also suppressing expression of numerous members of the pro-inflammatory NF-jB pathway, attenuating the excessive inflammatory response characteristic of diabetic wounds. Here we examine the underlying mechanisms of HOXA3 regulation of adult stem/progenitor cell migration and differentiation and describe a model for Hox transcription factor function in response to injury. Enhancing our understanding of how transcription factors can pre/re-programme stem/progenitor cells invivo will provide novel insights into molecular and cellular therapeutic medicines of the future.