α3β1-integrin regulates hair follicle but not interfollicular morphogenesis in adult epidermis

Abstract

α3β1-integrin is abundantly expressed in the epidermis, and in mice, ablation of the α3 gene results in embryonic defects and perinatal lethality. To determine the role of α3-integrin in adult skin development, we grafted skin from newborn α3-integrin-deficient mice on to ICRF nu/nu recipients. We report that adult α3-integrin-deficient skin has severe abnormalities restricted to hair follicle morphology, which include stunted hair follicle growth, increased hair follicle fragility,aberrant pigment accumulation and formation of hair follicle clusters. These abnormalities are caused by a combination of defects in: (1) keratinocyte cytoskeletal organisation, (2) outer root sheath architecture and (3)integrity of the lamina densa. Our results indicate that α3β1 is not essential for adult interfollicular epidermal differentiation, but it is required to direct several processes important in hair follicle maintenance and morphogenesis.