Expression of TGF-beta and its receptors in murine fetal and adult dermal wounds

The transforming growth factor-betas (TGF-betas) are of major importance in wound healing and have been implicated in the sear-less wound repair obser ved in fetuses. Few studies have characterised the role of TGF-beta in feta l wound repair and to date no studies have characterised the expression of its receptors within non-scarring fetal wounds. We have localised the TGF-b eta isoforms beta1, beta2 and beta3 and its two receptors, TGF-beta RI and TGF-beta RII in both adult and fetal dermal murine wounds. We observed low level immunofluorescence of TGF-beta1 and TGF-beta2 in fetal wounds and alt hough TGF-beta3 staining was observed in the epidermis of fetal skin, there was no upregulation. in response to injury. By contrast, all three isoform s were strongly expressed in adult wounds. Similar to its ligands, TGF-beta receptor expression was increased post-wounding in the adult wounds. Howev er, in contrast, no mRNA or protein for either of the TGF-beta receptors wa s observed in response to wounding in the fetal dermis although there was b oth mRNA and protein expression of both the receptors localised within them fetal alimentary tract, one of the few fetal organs which does sear postin jury. Them differences that we observed in the expression of TGF-beta and i ts receptors in adult and fetal wounds could be important in the absence of scar formation that is observed in the fetus.