Sweat gland stem cells in gland homeostasis and regeneration
Sweat-secreting sweat glands play a crucial role in thermoregulation. Failure to regulate sweating such as excessive perspiration, can significantly impact human quality of life. Because the homeostasis of exocrine glands including sweat glands is maintained throughout life by stem cells, uncontrollable sweating could be prevented through regulation of stem cells located within sweat glands. However, the existence of stem cells in human sweat glands remains to be determined. Here, we document the existence of human sweat gland stem cells enriched in the myoepithelial cell population that regenerate sweat gland-like spheres in vitro. These findings provide a tool to screen cosmetic ingredients using bioengineered sweat glandular organs and ultimately enable insight into the regulation of sweating.
Being in direct contact with the external environment, the epidermis is continually exposed to multiple types of harm, thus providing a shield against harmful substances and germs, such as bacteria and parasites. Consequently, the epidermis is a key therapeutic target for many cosmetic products. Epidermal components such as the interfollicular epidermis, hair follicles, sebaceous glands, and sweat glands, possess distinct features for maintaining epidermal homeostasis against environmental insults.
The interfollicular epidermis is a stratified epithelium comprised mainly of epidermal keratinocytes. Maintenance of the interfollicular epidermis relies on the proliferation and differentiation of basal epidermal cells on the basement membrane. Epidermal cells of the basal layers terminally differentiate into the stratum corneum (1) that functions as a barrier against water diffusion through the skin. The hair shaft, which consists of terminally differentiated keratinocytes derived from the hair follicle, exerts a broad range of functions including physical protection, sensory activity, and dispersion of sweat and sebum. Hair follicles ar ...