Fig. 1: Different SC populations in adult mouse skin and the major cell death programmes described in their niches.
From: Cell death as an architect of adult skin stem cell niches
The interfollicular epidermis of the skin consists of KCs, maintained by EpdSCs, and various immune cells. These SCs are attached to the basement membrane and give rise to transient amplifying cells capable to differentiate into corneocytes. In this epidermal niche, cell death is actively suppressed to ensure proper epidermal barrier formation, although recent findings describe the existence of specific NLRP10 inflammasome complexes, mediating pyroptotic cell death, in the differentiating epidermal layers [46]. HFs present in the skin are maintained by a specific population of SCs (HFSCs). In the HFSC niche, a substantial amount of KCs undergo periodic bouts of proliferation and subsequent apoptotic cell death. These apoptotic cells are phagocytosed by neighbouring basal KCs [23], ensuring absence of a significant immune response in this natural cycling process. Melanocyte stem cells (MeSCs) also populate the skin, and apoptosis of these cells has been linked to pigmentation disorders, such as vitiligo. SG sebaceous gland, DP dermal papilla.
