Double Mutation of Claudin-1 and Claudin-3 Causes Alopecia in Infant Mice

The study investigated the role of claudin proteins, specifically CLDN1 and CLDN3, in hair retention in mice. Researchers observed that mice with a double mutation in these proteins (Cldn1Δ/ΔCldn3−/−) experienced significant hair loss during the first telogen phase. This hair loss was linked to abnormalities in the hair follicles, such as disorganized epithelial cell layers and misplacement of bulges near sebaceous glands. These structural issues led to a shortened hair retention period and increased epithelial proliferation, resulting in accelerated hair regrowth in adult mice. The findings suggested that CLDN1 and CLDN3 were crucial for maintaining the proper architecture of hair follicles, and their deficiency could lead to alopecia in infant mice.