Sweat Gland Progenitors in Development, Homeostasis, and Wound Repair

Abstract

The human body is covered with several million sweat glands. These tiny coiled tubular skin appendages produce the sweat that is our primary source of cooling and hydration of the skin. Numerous studies have been published on their morphology and physiology. Until recently, however, little was known about how glandular skin maintains homeostasis and repairs itself after tissue injury. Here, we provide a brief overview of sweat gland biology, including newly identified reservoirs of stem cells in glandular skin and their activation in response to different types of injuries. Finally, we discuss how the genetics and biology of glandular skin has advanced our knowledge of human disorders associated with altered sweat gland activity.

Adult Gland Derived Stem Cells (Gdscs); Potentials, Hurdles and Expectations

“…Moreover, only basal progenitors within the sweat ducts, and not the secretory portion of the glands, responded and proliferated to repairing the duct orifice after injury with restoration of sweating [62]. These results provided compelling evidence supporting the notion that the sweat duct is the growth center which repairs the ductal orifice extending through the epidermis to the skin surface [72].…”

“…Intriguingly, despite their unipotent behavior in the adult gland, when myoepithelial cells are purified from adult sweat glands, they recreate the adult sweat glands. These findings suggest that the myoepithelial cells retain multipotent (bipotent) potential that can be unleashed when challenged to de novo morphogenesis [72].…”

Connexins and pannexins in the integumentary system: the skin and appendages

“…They play a central role in regulating body temperature and secrete water-based and salt-based liquid. In man, these glands are extensively distributed throughout the body, but highly concentrated on the palms and soles of adult human skin [55]. By contrast, most domestic animals lack eccrine sweat glands, although the mouse has them exclusively on the paws with the trunk skin lacking them altogether.…”

Changes in keratins and alpha-smooth muscle actin during three-dimensional reconstitution of eccrine sweat glands

“…Alpha-SMA is an actin isoform and is commonly used as a marker for myoepithelial cells (Schon et al 1999;Nagamoto et al 2000;Kawasaki et al 2008). Diverse keratins and alpha-SMA have been established as markers of differentiation, and their expression pattern varies with the type of epithelium, stage of development, and degree of differentiation (Moll et al 1982b(Moll et al , 2008Moll and Moll 1992;Schon et al 1999;Saga 2002;Lu et al 2012;Lu and Fuchs 2014;Li et al 2015b). In adult eccrine sweat glands, secretory cells express mainly K7, K8, K15, K18, and K19, whereas myoepithelial cells exhibit staining for K5, K14, K17, and alpha-SMA Moll 1991, 1992;Saga 2002;Li et al 2015b).…”