Chen Xi, Liu Guangpeng
Department of Plastic and Reconstructive Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China.
Department of Plastic and Reconstructive Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China.
Med Hypotheses. 2017 Jun;103:78-80. doi: 10.1016/j.mehy.2017.04.009. Epub 2017 Apr 20.
In old population, there is often a protrusion of the orbital fat pad underlying the skin in the lower eyelids, giving an aspect of palpable pouches. It is generally thought that orbital fat hyperplasia is the main contributing factor to the formation of baggy lower eyelids, and resection of excessive orbital fat pad is routinely performed during the eyelid cosmetic surgery. In our clinical study, however, it was revealed that the adipocytes in orbital fat tissue from older people became smaller compared to those from the young individuals. Based on this finding, we hypothesize that the orbital fat size may not increase, but decrease with age, and the declined fat depot volume is related to the reduced fat cell size and impaired differentiation of preadipocytes into fat cells. Adipose-derived stem cells (ASCs) are a population of postnatal stem cells residing in the fat tissue, capable of differentiating into preadipocytes and subsequently into mature fat cells throughout the lifespan. As preadipocytes are a substantial component of fat tissue and can greatly influence the fat composition and function, we speculate that orbital adipose-derived stem cells can be used as an excellent model to determine effects of aging on orbital fat. By evaluating the age-related changes in preadipocyte number, replication, and differentiation, we can reveal alterations in orbital fat cellularity and function with age, and investigate the relationship between orbital fat volume and the of baggy lower eyelid formation.
在老年人群中，下眼睑皮肤下的眶脂肪垫常常突出，形成可触及的眼袋外观。一般认为眶脂肪增生是下眼睑皮肤松弛形成的主要促成因素，在眼睑美容手术中通常会切除过多的眶脂肪垫。然而，在我们的临床研究中发现，与年轻人相比，老年人眶脂肪组织中的脂肪细胞变小。基于这一发现，我们推测眶脂肪大小可能不会随着年龄增长而增加，反而会减小，脂肪储存量的减少与脂肪细胞大小的减小以及前脂肪细胞向脂肪细胞分化受损有关。脂肪来源干细胞（ASCs）是一群存在于脂肪组织中的出生后干细胞，在整个生命周期中能够分化为前脂肪细胞，随后再分化为成熟脂肪细胞。由于前脂肪细胞是脂肪组织的重要组成部分，并且能够极大地影响脂肪的组成和功能，我们推测眶脂肪来源干细胞可作为一个很好的模型来确定衰老对眶脂肪的影响。通过评估前脂肪细胞数量、增殖和分化的年龄相关变化，我们可以揭示眶脂肪细胞数量和功能随年龄的改变，并研究眶脂肪体积与下眼睑皮肤松弛形成之间的关系。
