Development and homeostasis of the sebaceous gland

Abstract

The important role of epidermal appendages especially the sebaceous gland has only recently been recognised. In particular, it has been convincingly shown that normal development and maintenance of the sebaceous gland are required for skin homeostasis since atrophic sebaceous glands and disturbances in sebaceous lipid composition result in major defects of the physiological barrier and maintenance of the skin. Consequently, it is important to unravel the signalling network controlling proper sebaceous lineage differentiation in mammalian skin and to understand the underlying mechanisms leading to severe skin diseases, including abnormal proliferation and differentiation of the gland, defects of the lipid metabolism and barrier, as well as sebaceous tumour formation. Over the last years, results from transgenic and knock out mouse models manipulating distinct signalling pathways in the skin as well as the detailed analysis of human sebaceous gland-derived cell lines provided new insights into crucial mediators balancing proliferation and differentiation of the sebaceous gland. Here, we discuss our current knowledge of in vivo mechanisms of sebaceous gland development, maintenance and disorders and highlight recent contributions to the field of sebaceous gland biology.

Ligand‐independent epidermal growth factor receptor hyperactivation increases sebaceous gland size and sebum secretion in mice

“…Cell transplantation and lineage tracing studies revealed that the SG is fuelled by multiple stem cell populations (22,23). Committed cells entering the SG initially locate at the gland periphery and proliferate for some time, before accumulating large amounts of lipids to finally disintegrate and release their content via holocrine secretion (24,25).…”

p53/p63/p73 in the Epidermis in Health and Disease

“…In turn, p63 expression in epidermal keratinocytes is regulated by miR-203, miR-720, and miR-574-3p, which are expressed in cells within the suprabasal epidermal layer and restrict p63 expression to basal cells (Yi et al 2008;Chikh et al 2011). In addition to the hair bulb, epidermal progenitors generate the sebaceous gland, which secretes sebum via the duct penetrating the upper part of the follicular epithelium and extrudes it into the hair follicle infundibulum (Niemann and Horsley 2012). Postnatally, the hair follicle undergoes cyclic transformations with periods of active growth (anagen), involution (catagen), and resting (telogen) (Stenn and Paus 2001).…”

Skin-specific regulation of SREBP processing and lipid biosynthesis by glycerol kinase 5

“…Biosynthesis of cholesterol and other lipids in the skin is essential for the formation of the epidermal permeability barrier, for hair follicle morphogenesis, and for hair follicle maintenance (2)(3)(4)(5)(6)(7)(8). Sebaceous glands and epidermal keratinocytes are the two major sources of skin lipid production (9). Sebocytes are terminally differentiated epithelial cells of sebaceous glands that produce and secrete sebum, a lipid mixture composed of triglycerides and fatty acids (57.5%), wax esters (26%), squalene (12%), and cholesterol (4.5%) (10).…”