Runxi transcription factor is involved in the regulation of KAP5 gene expression in human hair follicles

摘要

In mammalian hair fibers, keratin intermediate filaments are embedded in the interfilamentous matrix containing keratin-associated proteins (KAPs). The KAP5 subfamily, an ultrahigh sulfur KAP (>30 mol% content), was recently characterized in human species, and consists of 11 genes located on human chromosome 11 p15.5 and 11q13.5 . The expression site of KAP5 genes is mostly restricted to the cuticle layer of anagen hair follicles . The runt-related protein (Runx) transcription factor family plays important roles not only in hematopoiesis, osteogenesis and neurogenesis, but also in developmental processes . Recently, it was reported that Runx3 is predominantly expressed in the dermal compartment of hair follicles during mouse morphogenesis and hair cycling . A DNA microarray analysis revealed that Runxi expression was up-regulated during anagen development induced by wax depilation in mice . Whereas numerous binding motifs of Runxi are predicted in the promoter region of human KAP10 and 12 family genes expressed in the cuticle , the roles of the Runx family in human hair follicles have not been explored. In this study, we examined the site of Runxi expression in human hair follicles by an immunohistochemical procedure, and the effect of Runxi on KAP5.1 gene expression by an overexpression study in the cell culture system.