Molecular alterations of decorin in photoaging process

Background

Decorin, a small leucine-rich proteoglycan, plays important biological roles, such as cell adhesion, migration, and proliferation in various matrix assemblies. The most important roles of decorin are to interact with several types of collagen and to modulate collagen fibrillogenesis in the body.

Objective

To analyze decorin expression in photoaging skin and the underlying molecular mechanisms of ultraviolet A (UVA) radiation in decorin production.

Method

Decorin and type I collagen production were immunohistochemically determined in photoaged rat skin. UVA-induced decorin production in the cultured fibroblasts was determined by western blot analysis.

Results

Decorin and aberrant type I collagen levels were increased in the upper dermis of rat skin treated with two minimum erythema dose (MED) of UV irradiation 120 times. Decorin production from the cultured fibroblasts was drastically increased by UVA irradiation and this was inhibited by sodium azide. Decorin production from the cultured fibroblast was also increased by 2–200 pg/mL of IL-1α and UVA-induced decorin was inhibited by anti-IL-1α antibody.

Conclusion

These results suggest that the increase of decorin production from fibroblasts after UVA irradiation is induced by IL-1α, which is released through the generation of singlet oxygen induced by UVA, and that the altered expression of decorin triggers the production of aberrant collagen, which might accelerate photoaging.