Regenerative potential of CD200- subpopulations of hair follicle bulge

The hair follicle bulge is regarded as a reservoir of epithelial stem cells for hair regeneration. Hair follicle bulge cells are generally characterized by CD200 expression. However, the relationship between CD200 + bulge subpopulations and human hair regenerative capacity remains unknown. In this study, we systematically investigated the CD200- and KRT15-expressing human hair follicle bulge cells by integrating phenotypic characterization, transcriptomic profiling, and in vivo hair regeneration assays. CD200 - cells from freshly isolated human hair follicle bulge exhibited higher hair-regenerative capability. Using different culture systems, we have observed the correlation between reduced CD200 expression and increased hair regenerative capability of cultured hair follicle bulge cells. Our study refines the functional interpretation of CD200-defined bulge heterogeneity and provides insights for optimizing human bulge cell–based approaches to hair follicle regeneration.