Increment of subcutaneous adipose tissue is associated with decrease of elastic fibres in the dermal layer

Abstract

Obesity is a significant risk factor for various skin disorders, including pressure ulcer and delayed wound healing. We previously showed that increment of subcutaneous adipose tissue contributes to poor skin condition by decreasing dermal elasticity. Here, we examined the mechanism involved. Histologic observation of abdominal skin from middle-aged females with a wide range of body mass index (BMI), an indicator of subcutaneous fat mass, showed that dermal elastic fibre abundance was significantly decreased with increment of BMI. Concomitantly, adipocytes were significantly enlarged. Adipocyte enlargement was significantly negatively correlated with dermal elastic fibre abundance. We hypothesized that enlarged adipocytes negatively influence dermal elastic fibres, so we investigated elastic fibre-degrading factors in in vitro-cultured enlarged adipocytes. MMP9 gene expression and secretion were significantly increased; further, these changes were blocked by extracellular signal-regulated kinase (ERK) inhibitor. Nuclear translocation (activation) of AP-1, a downstream ERK signalling molecule, was also observed in enlarged adipocytes. MMP9 abundance was significantly increased in skin of subjects with high BMI and enlarged adipocytes. These results suggest that increment of subcutaneous adipose tissue leads to adipocyte enlargement together with increased degradation of dermal elastic fibres, mediated at least in part by an ERK signalling-mediated increase of MMP9 in enlarged adipocytes.

Skin aging: are adipocytes the next target?

“…Enlarged adipocytes significantly suppress the synthetic activity of fibroblasts, whereas small adipocytes do not demonstrate such effects [109]. Very recently, it was also shown that the expansion of sWAT correlates with a decrease of elastic fiber content in the dermis [110]. Consequently, not only chronological or photo-induced aging, but also the local expansion of the adjacent adipose tissue can induce a relatively quick degradation of the elastic fibers in the dermis, which under normal conditions can persist there for many decades [111-113].…”

Dermal adipocytes’ claim for fame in psoriasis

“…In rodents, these compartments are clearly separated by a striated muscle, the panniculus carnosus, with the upper compartment termed dermal adipose layer (DAL), and were experimentally proven to be morphologically and developmentally distinct. Human skin does not have a detectable panniculus carnosus, while maintaining a functional and morphological distinction between dWAT and sWAT …”

A single‐center clinical trial to evaluate the efficacy of a tripeptide/hexapeptide antiaging regimen

“…In the process of adipogenesis, PGC1α expression is strongly induced in differentiation of preadipocytes of mesenchymal origin into white adipocytes. This differentiation of preadipocytes to white adipocytes occurs under the influence of PPARγ . The young adipocytes formed under these conditions appear to be small and active, and this size and activity have been seen to be synergistic and in line with good elastin formation .…”

“…This differentiation of preadipocytes to white adipocytes occurs under the influence of PPARγ . The young adipocytes formed under these conditions appear to be small and active, and this size and activity have been seen to be synergistic and in line with good elastin formation . In other words, large, mature adipocytes have been associated with diminished elastin—manifesting as aged sagging skin—whereas younger, smaller, newly synthesized adipocytes are accompanied by increased elastin levels.…”

“…In other words, large, mature adipocytes have been associated with diminished elastin—manifesting as aged sagging skin—whereas younger, smaller, newly synthesized adipocytes are accompanied by increased elastin levels. In addition, adiponectin secreted by small adipocytes (found in normal nonobese subjects) increases hyaluronic acid synthesis, whereas palmitic acid secreted by enlarged adipocytes (obese subjects) decreases collagen and elastin and fibroblast function . Fibroblasts cultured with enlarged adipocytes have shown decreased elastin gene expression.…”