Gene expression profile of the HOXA gene in adult dermal fibroblasts
The skin is the largest organ covering the entire body, composed of three layers: the epidermis, dermis, and subcutaneous tissue. While the thickness and elasticity of the skin are known to vary depending on the body site, the mechanisms underlying these differences remain unclear. Recent studies have reported that HOX genes, which determine positional identity during development, are also expressed and functional in adult tissues. We found that the expression of HOXA cluster genes in dermal fibroblasts derived from adult skin is regulated in a site-specific manner. Inhibition of HOXA9 expression in adult dermal fibroblasts resulted in decreased cell proliferation and downregulation of extracellular matrix-related genes. These findings suggest that the positional memory established by HOX genes during development is maintained in adults, contributing to the homeostasis and regional differences observed in adult skin. Overall design: To compare gene expression in various skin sites, gene expression profiling by RNA-seq was performed using dermal fibroblasts from the face, abdomen, and buttocks.