Label Retaining Cells with Myoepithelial Characteristics from the Proximal Acinar Region Define Stem Cells in the Sweat Gland

The study investigated label retaining cells (LRCs) in sweat glands (SGs) to determine if they possess stem cell characteristics. Using a H2BGFP LRCs system, researchers localized and isolated stem cells with myoepithelial characteristics in the SG proximal acinar region. These LRCs expressed keratin 15 and contributed to SG structure but not to epidermal homeostasis. Wound healing experiments showed that SG LRCs remained mostly quiescent, while non-LRCs actively divided. However, under isolated wound healing conditions, acinar LRCs could trans-differentiate into the epidermis. Additionally, dissociated SG cells could regenerate SGs and hair follicles, demonstrating their plasticity. The study identified up-regulation of Bone Morphogenetic Protein (BMP) pathway genes and the necessity of BMP receptor 1A signaling in SG formation. The findings highlighted the role of SG stem cells in SG homeostasis, wound healing, and their potential in regenerating skin appendages.