The effect of proteolytic enzymes on hair follicles of transgenic mice expressing the lac Z-protein in cells of the bulge region

Objective To study the effects of proteolytic enzymes on mice hair follicle s, particularly on cells of the bulge area regarded as follicle stem cells. Background Previous application by iontophoresis of proteolytic enzymes on guinea pig skin resulted in degenerative effects on hair follicles and the hypothesis was proposed that some of the affected cells could be stem cells . Methods To mark putative stem cells transgenic mice were produced carrying the lac-Z gene fused to the Upstream Regulatory Region (URR) of Human Papil loma Virus 11 (HPV11), as they express this gene specifically in the cells of the bulge area. Chymotrypsin and papain were applied on skin by iontopho resis, trypsin in the form of liposomes, Results Enzyme application, both by electrophoresis and as liposomes, led t o intense degenerative effects of the hair follicle, such as detachment of the inner root sheath, cystic dilation of the hair shaft and presence of ep ithelial cells within the lumen. Some of these cells represent hair follicl e stem cells expressing beta-galactosidase (beta-gal), having been detached from the bulge area as a result of enzyme treatment, implying impairment o f their function. (C) 1999 Elsevier Science B.V. All rights reserved.