Hair Cycle-Specific Immunolocalization of Retinoic Acid Synthesizing Enzymes Aldh1a2 and Aldh1a3 Indicate Complex Regulation
retinoic acid Aldh1a2 Aldh1a3 hair follicles outer root sheath basal layer spinous layer bulge area anagen phase catagen phase dermal papilla pre-cortex hair shaft epithelial proliferation differentiation hair growth hair cycling retinoic acid hair follicles outer root sheath basal layer spinous layer bulge area anagen phase catagen phase dermal papilla pre-cortex hair shaft epithelial proliferation differentiation hair growth hair cycling
TLDR The enzymes Aldh1a2 and Aldh1a3 are involved in making retinoic acid in hair follicles and have different roles in hair growth.
The study investigated the synthesis of retinoic acid in hair follicles by examining the expression of enzymes Aldh1a2 and Aldh1a3 in adult C57BL/6J mice. It found that Aldh1a2 was consistently expressed in the outer root sheath and basal/spinous layer across all hair cycle stages, and in the bulge area during anagen and early catagen phases. Aldh1a3, on the other hand, was primarily found in the dermal papilla, pre-cortex, and hair shaft during the mid to late anagen phase. These findings suggest that Aldh1a2 and Aldh1a3 are involved in different aspects of epithelial proliferation and differentiation within the hair follicle, indicating a complex regulation of retinoic acid synthesis that may affect hair growth and cycling.
