Connective tissue sheath of hair follicle is a major source of dermal type I procollagen in human scalp

摘要

Next, the changes in type I procollagen expression in the CTS during the hair cycle was investigated. Isolated HFs were classified into anagen, and early, mid, and late catagen on the basis of the hair growth in 2 weeks and the shape of the hair bulb, as previously described [6]. Increased expression of Type I procollagen was observed below the isthmus level in anagen, moderately decreased expression was observed in mid-catagen, and minimal expression was observed in late catagen (Fig. 2a). On the other hand, there were no visible changes of type I procollagen expression in the papillary and reticular dermis during anagen-catagen transitions. Considering that previous animal studies showed that skin containing anagen follicles has thicker dermis [7,8] and shorter healing time after burns [2] than skin containing telogen follicles, our findings support the speculation, contribution of CTS to the dermal matrix collagen.