Age‐related dermal collagen changes during development, maturation and ageing – a morphometric and comparative study

Abstract

The tissue organisation of dermal collagen is gaining importance as a contributing factor both in development and ageing, as well as in skin maturation processes. In this work we aim to study different representative parameters of this structural organisation in 45 human skin samples of assorted ages, by means of image analysis. The variation of these parameters on the basis of age was assessed using several regression models (linear, quadratic and cubic). The area occupied by collagen was significantly reduced as a function of age in the papillary dermis (R 2 = 0.437, P < 0.0001), as well as the thickness of the collagen bundles (R 2 = 0.461, P < 0.0001), following statistical models of cubic and quadratic regression, respectively. The width of the papillary dermis increased in a significant manner over a linear regression model (R 2 = 0.26, P < 0.0001). In the reticular dermis, the cubic regression indicated a significant decline (R 2 = 0.392, P = 0.002) of the area filled with collagen according to the age. Both collagen thickness and bundle orientation parameters fit a quadratic regression over the age in a significant way (R 2 = 0.433 and R 2 = 0.334, respectively, both P < 0.0001). The width of the reticular dermis followed also a significant quadratic distribution according to age (R 2 = 0.193, P = 0.011). These parameters could partially explain the lifelong functional changes taking place in the skin and propose a baseline providing a useful entry point for future investigation.

Reliable assessment of forearm photoageing by high‐frequency ultrasound: a cross‐sectional study

“…Increased levels of reactive oxygen species and a decrease in the levels of antioxidants, with higher expression of several matrix metalloproteinases (MMP – degrading enzymes that act on extracellular matrix molecules producing fragmented collagen remainders) are other features. The accumulation of advanced glycosylation end products in dermal collagen also results in catabolic effects . Previous histopathologic study on skin ageing (abdominal skin) demonstrated that papillary dermis thickness increased with age together with a decrease in collagen bundles thickness and a diminution in the area occupied by collagen, in both the papillary and reticular dermis, from 40 years of age onwards.…”

“…Extrinsic ageing, also called photoageing, occurs mainly due to the harmful effects of UVR, although smoking habits and environmental pollution are other contributing factors . A gene expression profile study showed markedly increased expression of elastic fibre components in photoaged skin (elastin, fibulins and fibrillin), while a reduced expression of some dermal collagens during skin ageing achieved statistical significance only in intrinsically aged skin .…”

“…Extrinsic ageing, also called photoageing, occurs mainly due to the harmful effects of UVR, although smoking habits and environmental pollution are other contributing factors . A gene expression profile study showed markedly increased expression of elastic fibre components in photoaged skin (elastin, fibulins and fibrillin), while a reduced expression of some dermal collagens during skin ageing achieved statistical significance only in intrinsically aged skin . UV radiation induces the production of catabolic enzymes, specifically MMPs, which cleaves the major interstitial collagens and may explain the reduced collagen staining in the reticular dermis in sun‐exposed skin that correlates with the areas of deposited elastotic material in the upper dermis .…”

Bad company: Microenvironmentally mediated resistance to targeted therapy in melanoma

“…ECM composition and structure change dramatically with age. After 65 years of age, the dermal ECM exhibits decreased fiber area and thickness, which results in impaired mechanical properties (Diridollou et al, ; Lee et al, ; Marcos‐Garces et al, ; Oh et al, ; Panwar et al, ). We have recently identified age as a key promoter of melanoma metastasis and resistance to MAPKi (Kaur et al, ).…”

Action of hyperbaric oxygenation in the rat skin flap

“…Lv et al 16 reported that treatment with HBO counteracted fibrous adhesions, as it inhibited inflammation and collagen deposition, preventing epidural scar adhesion in rat. Collagen fibers is an extracellular matrix constituent of the dermis and is synthesized by fibroblasts, while inflammatory processes related to the enzymatic action of metalloproteinases and collagenase inhibit it 17 . FIGURE 2 -Photomicrographs showing skin transverse sections of rats from all groups of study.…”