Significance and characteristics of p63 and cytokeratin expression during skin expansion

Objective To investigate the mechanism of epidermal proliferation and differentiation under the influence of skin expansion.Methods 12 expanders were implanted on the back of 36 male Wistar rats,in which expansion pressure was maintained at 5.33 kPa.Samples were collected at 1st,2nd,3th,7th and 10th day during expansion process,and 7th day post-expansion.P63 and cytokeratin 19,14 were identified to distinguish epidermal stem cells from transit amplifying cells with PowervisionTM two-step immunohistochemical method.Results The thickness of the expanded epidermis was increased,which was thicker than that of control group(P0.01).The numbers of epidermal stem cells and transit amplifying cells of the expanded epidermis were increased and both cells were found in the stratum spinosum and stratum granulosum of epidermis.Conclusion Skin expansion can induce and promote epidermal stem cells to proliferate and differentiate,which indicates that epidermal stem cells respond to mechanical stress and wound repair probably is its major biological basis.