Characterization of New Stem/Progenitor Cells in Skin Appendages

The study identified slow cycling label retaining cells (LRCs) in the sweat gland and nail skin appendages, which exhibited stem cell characteristics similar to those of hair follicle stem cells. These LRCs were localized to specific regions in the nails and sweat glands and expressed K15, a known hair follicle stem cell marker. Lineage tracing experiments indicated their long-term self-renewal capabilities. Gene expression profiling revealed BMP pathway signaling genes in both appendages, and functional experiments demonstrated the necessity of Bmpr1a-mediated signaling. The findings suggested that sweat gland LRCs could differentiate and contribute to the epidermis during prolonged wound healing, and transplantation experiments indicated their potential plasticity in regenerating sweat glands and hair follicles. The study concluded that these LRCs might serve as putative stem cell markers for human nails and sweat glands, although further research was needed for comprehensive characterization.