Li Yu, Long Jie, Zhang Ziang, Yin Wen
Xijing Hospital, Air Force Medical University, Xi'an, Shaanxi, China.
Front Physiol. 2024 Feb 23;15:1346612. doi: 10.3389/fphys.2024.1346612. eCollection 2024.
Dermal white adipose tissue (dWAT) is a newly recognized layer of adipocytes within the reticular dermis of the skin. In many mammals, this layer is clearly separated by panniculus carnosus from subcutaneous adipose tissue (sWAT). While, they concentrated around the hair shaft and follicle, sebaceous gland, and arrector pili muscle, and forms a very specific cone geometry in human. Both the anatomy and the histology indicate that dWAT has distinct development and functions. Different from sWAT, the developmental origin of dWAT shares a common precursor with dermal fibroblasts during embryogenesis. Therefore, when skin injury happens and mature adipocytes in dWAT are exposed, they may undergo lipolysis and dedifferentiate into fibroblasts to participate in wound healing as embryogenetic stage. Studies using genetic strategies to selectively ablate dermal adipocytes observed delayed revascularization and re-epithelialization in wound healing. This review specifically summarizes the hypotheses of the functions of dWAT in wound healing. First, lipolysis of dermal adipocytes could contribute to wound healing by regulating inflammatory macrophage infiltration. Second, loss of dermal adipocytes occurs at the wound edge, and adipocyte-derived cells then become ECM-producing wound bed myofibroblasts during the proliferative phase of repair. Third, mature dermal adipocytes are rich resources for adipokines and cytokines and could release them in response to injury. In addition, the dedifferentiated dermal adipocytes are more sensitive to redifferentiation protocol and could undergo expansion in infected wound. We then briefly introduce the roles of dWAT in protecting the skin from environmental challenges: production of an antimicrobial peptide against infection. In the future, we believe there may be great potential for research in these areas: (1) taking advantage of the plasticity of dermal adipocytes and manipulating them in wound healing; (2) investigating the precise mechanism of dWAT expansion in infected wound healing.
真皮白色脂肪组织（dWAT）是皮肤网状真皮内新发现的一层脂肪细胞。在许多哺乳动物中，这一层通过肉膜与皮下脂肪组织（sWAT）明显分隔开。然而，它们聚集在毛干和毛囊、皮脂腺及立毛肌周围，并在人类中形成非常特殊的锥形结构。解剖学和组织学均表明dWAT具有独特的发育和功能。与sWAT不同，dWAT的发育起源在胚胎发生过程中与真皮成纤维细胞有共同的前体。因此，当皮肤受伤且dWAT中的成熟脂肪细胞暴露时，它们可能会发生脂解并去分化为成纤维细胞，在胚胎发育阶段参与伤口愈合。利用基因策略选择性消融真皮脂肪细胞的研究观察到伤口愈合过程中血管再形成和上皮再形成延迟。本综述特别总结了dWAT在伤口愈合中功能的假说。首先，真皮脂肪细胞的脂解可通过调节炎性巨噬细胞浸润促进伤口愈合。其次，真皮脂肪细胞在伤口边缘丢失，然后脂肪细胞衍生的细胞在修复的增殖期成为产生细胞外基质的伤口床肌成纤维细胞。第三，成熟的真皮脂肪细胞是脂肪因子和细胞因子的丰富来源，可在损伤时释放它们。此外，去分化的真皮脂肪细胞对再分化方案更敏感，可在感染伤口中增殖。然后我们简要介绍了dWAT在保护皮肤免受环境挑战方面的作用：产生抗菌肽以抵抗感染。未来，我们认为这些领域可能有很大的研究潜力：（1）利用真皮脂肪细胞的可塑性并在伤口愈合中对其进行调控；（2）研究dWAT在感染伤口愈合中增殖的确切机制。
