Impact of Solar Ultraviolet Radiation in the Expression of Type I Collagen in the Dermis

Ultraviolet radiation exposure is the dominant environmental determinant of all major forms of skin cancer, and the main cause of prematurely aged skin that is referred to as photoaging. Collagen type I (COL I) is expressed differently along with the dermis between healthy and pathological skin tissues. The aim of this study was to understand the impact of solar radiation in the dermis and assess the impact of solar radiation to COL I. The hematoxylin and eosin staining protocol was performed in tissue paraffin blocks and then they were stained immunohistochemically with the rabbit monoclonal anti-COL I antibody. A total of 270 slides were studied with an Olympus BX 41 microscope; we scored positively the expression of COL I in dermis and statistically analyzed with IBM SPSS Statistics. Based on our results, we observed that solar elastosis changes the structure of the skin's collagen. In healthy tissues, COL I had a uniform expression along with the dermis. In tissues with aging, COL I expression was weaker and lost homogeneity. In pathological tissues (non-melanoma skin cancers, NMSCs), precancerous lesions, and benign skin lesions), the expression of COL I was observed to be almost weaker than tissues with aging in all body parts and much weaker below the lesions. The most severe solar elastosis was observed in the extremities. The degree of severity of the solar elastosis in relation to age did not appear to be completely affected. Solar radiation divides the collagen more rapidly than normal biological aging and solar elastosis was observed into the skin tissues with photoaging, which replaces the collagen fibers of the skin. These results confirm previous studies, which have shown that skin COL I decreases during aging, more in photoaging and even more in skin cancers. We conclude that skin COL I expression is reduced as a result of ultraviolet radiation and leading to negative impacts on the skin.