We recently discovered a nonsynonymous variant in the coiled-coil alpha-helical rod protein 1 (CCHCR1) gene within the alopecia areata (AA) risk haplotype. We also reported that the engineered mice with this risk allele exhibited. To investigate more about the involvement of the CCHCR1 gene in AA pathogenesis, we developed an AA model using C57BL/6N cchcr1 gene knockout mice. In this study, mice (6–8 weeks) were divided into two groups: cchcr1^−/− mice and wild-type (WT) littermates. Both groups were subjected to a water avoidance stress (WAS) test. Eight weeks after the WAS test, 25% of cchcr1^−/− mice exhibited non-inflammatory foci of alopecia on the dorsal skin. On the other hand, none of wild-type littermates cause hair loss. The foci resembled human AA in terms of gross morphology, trichoscopic findings and histological findings. Additionally, gene expression microarray analysis of cchcr1^−/− mice revealed abnormalities of hair related genes compared to the control. Our results strongly suggest that CCHCR1 is associated with AA pathogenesis and that cchcr1^−/− mice are a good model for investigating AA.

Koyama S, et al. Ann Dermatol. 2023 Sep;35:e115. https://doi.org/10.5021/ad.22.227

Ikeda Y, et al. Ann Dermatol. 2023 Jul;35:e105. https://doi.org/10.5021/ad.21.279