Modulação da elastina cutânea induzida pelo fotoenvelhecimento: avaliação da expressão gênica e proteica de marcadores relacionados à elastogênese em diferentes condições de fotoexposição

• Autor(a) principal: Weihermann, Ana Cristina
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório do Centro Universitário Braz Cubas
• Texto Completo: https://repositorio.cruzeirodosul.edu.br/handle/123456789/2596
• topic: Elastina; Fotoenvelhecimento; Elastose solar; Splicing alternativo; CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL

Photoaging is a process triggered by environmental factors, especially by exposure to solar radiation and leading to development of clinical skin changes. Elastin is a matrix protein that provides a great importance in skin resilience and elasticity, and has a strong relation with photodamage by appearance of clinical features known as solar elastosis. Thus, the objective of this research was to identify a specific structural modification caused by alternative splicing that can occur in elastin after sun exposure, known as exon 26A, in in vitro models of reconstituted skin and ex vivo skin for analysis of gene expression by qPCR. We also evaluated other molecules related to elastogenesis (normal elastin, tropoelastin, fibrillin 1, LOX and MAGP2) and the main metaloproteinase that degrades elastin (MMP12) by qPCR assays and immunohistochemical analyzes. The results obtained from the gene expression analyzes of ex vivo skin showed that the modified elastin (26A) is increased in sun-exposed conditions (3,61 times in face lifting and 2,58 times in blepharoplasty) with a significant increase (p value = 0,0008 and 0,0076 respectively) when compared to non-photoexposed controls. The MMP12 also increase by 5.98 times in face lifting and 3,14 times in blepharoplasty, these being significant data (p value <0,0001 and 0,0096 respectively) and LOX increased significantly in blepharoplasty region (increase by 1,64 times and p value = 0,0080). In gene expression analysis of reconstructed skin, we observed a significant increase of altered elastin by 4,59 times in irradiated skin when compared to non-irradiated conditions (p value = 0,0298). By immunohistochemical analyzes of reconstructed skins it was observed an increase of tropoelastin and fibrillin 1 expression in sunexposed conditions and other markers used differences were not observed. Thus, this work can contribute to a better understanding of another important process of photoaging and allow to obtain new compounds and cosmetics products that could prevent or reduce photoaging. This work is divided into two chapters. The first chapter refers to a literature review on the elastin role in photoaging and the second chapter consists of an experimental scientific article with the results obtained with this project.