Molecular Mechanisms of Dermal Aging and Antiaging Approaches

Abstract

The dermis is primarily composed of the extracellular matrix (ECM) and fibroblasts. During the aging process, the dermis undergoes significant changes. Collagen, which is a major component of ECM, becomes fragmented and coarsely distributed, and its total amount decreases. This is mainly due to increased activity of matrix metalloproteinases, and impaired transforming growth factor-β signaling induced by reactive oxygen species generated during aging. The reduction in the amount of collagen hinders the mechanical interaction between fibroblasts and the ECM, and consequently leads to the deterioration of fibroblast function and further decrease in the amount of dermal collagen. Other ECM components, including elastic fibers, glycosaminglycans (GAGs), and proteoglycans (PGs), also change during aging, ultimately leading to a reduction in the amount of functional components. Elastic fibers decrease in intrinsically aged skin, but accumulate abnormally in photoaged skin. The changes in the levels of GAGs and PGs are highly diverse, and previous studies have reported conflicting results. A reduction in the levels of functional dermal components results in the emergence of clinical aging features, such as wrinkles and reduced elasticity. Various antiaging approaches, including topicals, energy-based procedures, and dermal fillers, can restore the molecular features of dermal aging with clinical efficacy. This review summarizes the current understanding of skin aging at the molecular level, and associated treatments, to put some of the new antiaging technology that has emerged in this rapidly expanding field into molecular context.

Overlooked and underestimated: medical adhesive-related skin injuries

“…Older people experience loss of dermal matrix and subcutaneous tissue, epidermal thinning, lower cohesion between the dermis and epidermis, reduced blood supply to the skin, dehydration, and reduced collagen, elasticity and tensile strength. 1,[15][16][17][18] Disease-related pathologies, exposure to ultraviolet light and certain medications also contribute to skin ageing. Figure 3 illustrates the di erences between aged and young skin.…”

<p>Polycaprolactone: How a Well-Known and Futuristic Polymer Has Become an Innovative Collagen-Stimulator in Esthetics</p>

“…The collagen-related aging process has been extensively investigated and reviewed; few reviews are cited. [52][53][54][55][56][57][58][59] The PCL-filler is a collagen stimulator, as demonstrated in animals and humans treated by the S-and/ or M-PCL products. Biopsies examined in histology using specific staining (Picro-Sirius Red) showed an increase in collagen and allowed collagen subtypes determination.…”

Wheat Extract Oil (WEO) Attenuates UVB-Induced Photoaging via Collagen Synthesis in Human Keratinocytes and Hairless Mice

“…Collagen is synthesized in the form of a precursor (procollagen) [36], and as a major structural protein present in the dermal layer, it is critical for skin elasticity. Eighty to ninety percent of skin collagen is type I collagen and is essential for preventing skin damage from UV rays, maintaining the moisture balance to prevent wrinkles and preserve the elasticity of the skin [37]. MMP-1, as a collagenase-specific protease, has been shown to facilitate the decomposition of collagen and to reduce elasticity [38,39].…”