Keratins 1 and 10 as Regular Constituents of Inner Root Sheath and Cuticle Cells in the Human Hair Follicle

The study provided evidence for the presence of keratins K1 and K10 in the inner root sheath (IRS) and cuticle of the human hair follicle, suggesting similarities in differentiation processes with other keratinizing epithelia. Through protein analysis and immunofluorescence, the researchers identified K1 and K10 derivatives in isolated fractions, with specific antibodies confirming their presence. The study found that these keratins were present in lower follicle fractions, indicating minimal epidermal contamination. The findings suggested that differentiation in the IRS and cuticle might follow common keratinization principles, with immunodetection showing distinct staining for K1 and K10 up to the "keratinizing zone" of the follicle.