K15 And Id3 Expression In Intact And Regenerating Adult Vibrissae Rodent Hair Follicles

In 2009, Bo Chen's Master's thesis investigated the expression of Keratin 15 (K15) and Id3 in intact and regenerating adult vibrissae rodent hair follicles. The study found that K15, an epithelial stem cell marker, predominantly covers the lower hair follicle and its expression varies depending on the different stages of the hair follicle cycle. This supports the "traffic light model" where epithelial stem cells migrate during follicle stages. Id3, a transcriptional regulator protein, was found to be expressed in both epithelial and dermal cells during the hair follicle cycle. The study also observed a cellular translocation phenomenon during the Anagen stage, suggesting a shift in cell activities between proliferation and differentiation. During the regeneration of hair follicles, the number of K15 positive epithelial cells significantly increased at the initial stages, while the response of Id3 positive cells was relatively late. The study concluded that both K15 and Id3 play significant roles in the hair follicle regenerating process, although their specific roles remained unclear.