Differentiation and characterization of human facial subcutaneous adipocytes.
Chon SH, Pappas A.
Adipocyte. 2014 Nov 14;4(1):13-21. doi: 10.4161/21623945.2014.955402. eCollection 2015 Jan-Mar.
-Aging is associated with the loss of facial subcutaneous fat and with increased abdominal subcutaneous fat.
-With age there is volume loss of the face which is can be attributed to dermal volume loss (collagen, hyaluronic acid). However facial shape (an aging as well), like body “curves” are mainly a role subcutaneous tissue plays.
-Subcutaneous tissue is mainly composed of fat cells called adipocytes. Fat transfers obey the principle of autologous grafts, that it that they are taken from a “donor” area (often the abdomen) and injected to a recipient area for example on the face. Autologous grafts enable immune reactions which result in tissue rejection.
-That being said fat transfer is still often a failure because the fat cells “disappear” (dissolution). This can be attributed to difference in properties between abdominal and facial adipocytes; as shown in the following study:
Site specific differences in adipocyte phenotype and/or gene expression may play a role in these age-related changes.
In this study, the authors isolated facial precursors of fat cells (preadipocytes) and compared their capacity to differentiate with abdominal preadipocytes
-the preadipocytes were isolated from human facial and abdominal tissue and cultured in vitro and then exposed to differentiation factors called rosiglitazone (in more detail it is a peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist), isobutyl-methyl xanthine (IBMX) and insulin.
-the differentiation was measured visually and with real-time PCR.
1. An increased Capacity to Adapt
-Results showed that facial fat cell precursors had superior differentiation capabilities when exposed to rosiglitazone and it remained longer (11 cell culture transfers vs 5 in the abdominal preadipocytes)
2. An increased Capacity to Stay In Place
–Facial adipocytes were more resistant to dissolution (lipolysis) than their abdominal counter when they were exposed to isopretenerol. This is a B2-adrenergic receptor agonist and the receptor was consistently found to be reduced by 60% in facial cells.
3. Genetic differences
-Gene markers were similar except for β3-adrenergic receptor which was only found in abdominal adipose tissue.
-Gene profiling showed that several HOX genes are strongly reduced in facial adipocytes compared to abdominal adipocytes, suggesting different characteristics between the 2 fat depots.
Article selection: Prof Dr Jean-Hilaire Saurat – dermatologist. Geneva, Switzerland