Modulation of Photoaging-Induced Cutaneous Elastin: Evaluation of Gene and Protein Expression of Markers Related to Elastogenesis Under Different Photoexposure Conditions

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.