Acquired Curved Hair Is Caused by Fusion of Multiple Hair Matrix Cells

The study "Acquired curved hair is caused by fusion of multiple hair matrix cells" reveals that the fusion of hair matrix cells during hair follicle regeneration is a cause of acquired curved hair. This fusion leads to abnormal differentiation of hair follicle tissue, resulting in asymmetric hair follicle shapes and curved hair. The research used outer root sheath cells (ORSC) isolated from plucked human hair follicles and straight and curved hairs with hair follicle tissue attached from the same individuals. It was found that the amount of type IV collagen increased upon inducing endoplasmic reticulum stress in ORSC, while in curved hair follicle tissue, the gene expression of type IV collagen decreased. The study also observed that hair matrix cells based on multiple hair germs fused to form a single hair follicle and hair shaft. In curved hair follicle tissue, KRT71 protein was unevenly distributed and there was elevated expression of Dickkopf-1 (DKK1) protein, an inhibitor of the Wnt signaling pathway.