Trichohyalin: Presence in the Granular Layer and Stratum Corneum of Normal Human Epidermis

The study demonstrated that trichohyalin, a protein previously known to be present in hair follicles and tongue epithelium, was also found in the granular layer and stratum corneum of normal human epidermis. Using polyclonal and monoclonal antibodies, researchers identified trichohyalin as a 220-kDa band in human hair bulb proteins and confirmed its presence in the epidermis through immunofluorescence and immunoblotting. The study also revealed that trichohyalin coexists with filaggrin in some epidermal cells, indicating its broader distribution beyond hair and tongue tissues.