Dermal white adipose tissue: Development and impact on hair follicles, skin defense, and fibrosis

Dermal white adipose tissue (DWAT) is a distinctive adipose depot located within the lower dermis of the skin. Its significance as an ancillary fat in skin homoeostasis has recently received increased attention. New research has revealed that DWAT responses to skin pathology and physiology changes, impacting skin development, hair cycling, defense mechanisms, and fibrotic conditions. In this review, we explore the developmental process of DWAT and the adipose commitment timing of hypodermal. We explore the development process of DWAT and its pivotal role in regulating the hair cycle. We conclude the antibacterial activity and reversible dedifferentiation of dermal adipocytes in response to skin defense. Furthermore, we underscore the potentially crucial yet underestimated anti-fibrotic functions of DWAT-derived adipokines and adipocyte-myofibroblast transition. (A) Dermal fibroblast progenitors differentiate into hypodermal/recticular progenitors and ultimately differentiate into dermal adipocytes. (B) During the hair follicle cycling, dermal adipocytes interact with hair follicles through multiple signaling pathways. (C) Reactive adipogenesis in dermal adipose tissue produces large amounts of cathelicidin antimicrobial peptide (CAMP) to fight infection. Dermal adipocytes participate in injury repair through lipolysis and recruitment of macrophages. (D) Adipocyte-myofibroblast transition (AMT) occurs in fibrotic skin, and reversing the AMT process is a potential treatment option for fibrosis.image