The role of metalloproteinase-8 and TGF-B/Smad pathway in skin photoageing

Abstract

Introduction: Skin aging is a complex process composed of sequential phenomena which leads to structural and functional changes. There are many pathways leading to photoageing, but mechanisms are not well elucidated. Matrix metalloproteinases are family of proteases known to degrade collagen. Aged skin is accompanied by higher metalloproteinase production, leading to degradation of extra cellular matrix. Another pathway of ageing is complex TGF-b/Smad. Transforming growth factor-b is the primary regulator of collagen synthesis in skin. It has been reported that UV irradiation impairs TGF-b/Smad signaling through downregulating the transcription.
Material and methods: The aim of the study was to asses expression of MMP-8, TGF-b and Smad in 3 groups. Group 1– 15 volunteers after one week sun bathing, group 2–15 volunteers with photo damaged skin and group 3-control group volunteers from group 1 before holidays.
Results: Immunoexpression of MMP-8 was significantly higher in group 1 and group 2 comparing to control group. Immunoexpression of TGF-b and Smad was significantly lower in group 1 and 2 comparing to control group.
Conclusions: Obtained results confirmed dysregulation of TgfB/Smad pathway under the influence of short and long term exposure to UV radiation. The role of uv radiation in indication of the expression of metalloproteinase-8 was confirmed.