Skin aging is a complex process that may be caused by factors that are intrinsic and extrinsic to the body. Ultraviolet (UV) radiation represents one of the main sources of skin damage over the years and characterizes a process known as photoaging. Among the changes that affect cutaneous tissue with age, the loss of elastic properties caused by changes in elastin production, increased degradation and/or processing produces a substantial impact on tissue esthetics and health. The occurrence of solar elastosis is one of the main markers of cutaneous photoaging and is characterized by disorganized and non-functional deposition of elastic fibers. The occurrence of UV radiation-induced alternative splicing of the elastin gene, which leads to inadequate synthesis of the proteins required for the correct assembly of elastic fibers, is a potential explanation for this phenomenon. Innovative studies have been fundamental for the elucidation of rarely explored photoaging mechanisms and have enabled the identification of effective therapeutic alternatives such as cosmetic products. This review addresses cutaneous photoaging and the changes that affect elastin in this process.R esum e Le vieillissement de la peau est un processus complexe qui peutêtre caus e par des facteurs intrins eques et extrins eques du corps. Les rayons ultraviolets (UV) repr esentent l'une des principales sources de dommages de la peau au fil des ans et caract erise un processus connu sous le nom de photo-vieillissement. Parmi les changements qui affectent le tissu cutan e avec l'âge, la perte des propri et es elastiques caus ees par des changements dans la production d' elastine, augmentation de la d egradation et / ou le traitement, produit un impact important sur l'esth etique et la sant e des tissus. La survenue d'une elastose solaire est l'un des principaux marqueurs de photo-vieillissement cutan e et se caract erise par un d epôt d esordonn e et non-fonctionnel des fibres elastiques. L'apparition d'un epissage alternatif du g ene de l' elastine induit par le rayonnement UV, ce qui conduit a une synth ese insuffisante des prot eines n ecessaires a l'assemblage correct des fibres elastiques, est une explication possible de ce ph enom ene. Des etudes novatrices ont et e fondamentales pour l' elucidation des m ecanismes de photovieillissement rarement explor es et ont permis l'identification d'alternatives th erapeutiques efficaces, tels que les produits cosm etiques. Cette revue porte sur le photo-vieillissement cutan e et les changements qui affectent l' elastine dans ce processus.

Introduction: Photoaging is the process by which ultraviolet rays gradually induce clinical and histological changes in the skin through the production and organization of biological molecules, such as elastin, which is critical to skin strength and elasticity. After exposure to radiation, elastin may undergo alternative mRNA splicing, resulting in modified proteins that contribute to the formation of aging characteristics, such as solar elastosis. The present work aimed to study two different forms of elastin under these conditions: normal elastin and elastin that had been altered in exon 26A.Methods: These different forms of elastin were characterized for gene expression by quantitative real-time polymerase chain reaction (qPCR) and for protein expression by immunohistochemistry of ex vivo skins (from photoexposed and non-photoexposed areas) and in vitro reconstituted skin. In addition, up-and downstream molecules in the elastin signaling cascade were evaluated. Results: As a result, a significant increase in the gene expression of elastin 26A was observed in both ex vivo photoexposed skin tissues and the in vitro photoexposed reconstituted skins. Additionally, significant increases in the gene expression levels of matrix metalloproteinase-12 (MMP12) and lysyl oxidase (LOX) were observed in the ex vivo skin model. The evaluation of protein expression levels of some photoaging markers on the reconstituted skin revealed increased tropoelastin and fibrillin-1 expression after photoexposure. Conclusion: This work contributes to a better understanding of the biological mechanisms involved in photoaging, making it possible to obtain new strategies for the development of dermocosmetic active ingredients to prevent and treat skin aging.

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