Differentiation of the sebaceous gland

Abstract

The sebaceous gland is renewed throughout adult life and homeostasis of this particular organ is controlled by a precise interplay of hormones, cytokines, signalling molecules and mediators of the lipid metabolism. Although the true function of sebaceous glands has yet to be fully determined, recent evidence demonstrates that normal homeostasis of the sebaceous gland and functional lipid metabolism of sebocytes is crucial for maintenance of the skin barrier. In addition, analysis of mutant mouse models revealed a close interdependency of the sebaceous gland with hair follicles because abnormal morphogenesis of sebaceous glands often results in degeneration of hair follicle structures. Anomalous regulation of sebaceous glands is involved in the pathogenesis of acne, one of the most prevalent human diseases, or could lead to formation of sebaceous hyperplasia and tumours. This review highlights some of the recent findings on the importance of signalling pathways controlling morphogenesis and differentiation of the sebaceous gland in vivo.

Keywords: SCD1; c-myc; differentiation; epidermis; hedgehog; sebaceous gland; sebocyte; skin; β-catenin.

Figure 1

Wholemount of pilosebaceous unit isolated from mouse tail skin. Micrograph of wholemount stained with hematoxylin displaying two pilosebaceous units of mouse skin. B, bulge region of the hair follicle containing the stem cell compartment; HF, hair follicle; IFE, interfollicular epidermis; SG, sebaceous gland.

Figure 2

Signals controlling sebocyte differentiation in vivo. Summary of major signalling pathways regulating differentiation of the sebaceous gland in vivo. Repression of β-catenin signalling and activation of c-myc and hedgehog signalling cascade are important for the differentiation and maturation process experienced by sebocytes.