2019 Volume 43 Issue 4 Pages 303-308
It is well known that ultraviolet rays cause photo-aging. Ultraviolet A (UVA) is the most important factor in photo-aging, especially in human dermis. As investigation of photo-aging in vitro, we previously reported that normal human dermal fibroblast (NHDF) was calcified by UVA irradiation. In this study, NHDF was cultured for one day after 0.8 J/cm2 UVA irradiation to investigate the influence of UVA irradiation, which calcifies cells. In addition, physiological and molecular biological changes on UVA irradiated NHDF were investigated. As a result, it was suggested that a significant oxidative stress was given to UVA irradiated NHDF, because accumulation of carbonylated proteins were observed in the cell. Moreover, it was elucidated that the intracellular Ca2+ mobilization indicated that an induction of inflammation was accelerating because of Ca2+ accumulation in the cell. Furthermore, it was suggested that calcification of UVA irradiated NHDF was involved in a decrease in cell survival rate. In molecular biological analysis, gene expression of PiT-1, Runx2, OCN and OPN which were well-known as osteogenesis marker on vascular smooth muscle cell (VSMC), were investigated on UVA irradiated NHDF using molecular biological method. As a result, increasing gene expression of PiT-1 and OPN was observed on UVA irradiated NHDF, although gene expression of Runx2 and OCN was not observed in the cell. From the results in this study, it was elucidated that NHDF calcified by UVA irradiation was involved in some significant damages, oxidation stress, calcium accumulation indicated inflammatory inducement in cells and decreased cell survival rate. On UVA irradiated NHDF, further investigation of physiological, biochemical, and molecular biological approach are required to determine the relationship between these physiological changes and calcification.
