Altered vimentin protein expression in human dermal microvascular endothelial cells after ultraviolet or intense pulsed light treatment

Background Endothelial cell senescence is closely related to tissue aging and age-related vascular disease. Detailed pathophysiology and essential biomarkers of skin aging are not well known. A recent report suggests that advanced glycosylation end products, especially N^ε- (carboxymethyl)lysine (CML) modification of vimentin, accelerate the aging process. Objectives To identify protein biomarkers of aging in skin. Materials and Methods Proteomics analysis was performed to identify differentially expressed proteins in human dermal microvascular endothelial cells (HDMEC) treated with ultraviolet (UV) or intense pulsed light (IPL). Proteome maps of UV-treated, IPL-treated, and untreated HDMEC were constructed, with identification of altered protein spots by matrix-assisted laser desorption/ionization mass spectrometry. Differential expression and glycation modification of vimentin were found by this approach and further examined by fluorescence-activated cell sorting. Results Twenty-two differentially expressed protein spots were identified. Among them, vimentin was specifically up-regulated in UV-treated HDMECs. On the other hand, it was down-regulated after IPL. Increased expression of CML-vimentin in HDMEC during culture (Passage 6 vs. 12) was noted, and this effect was reversed by IPL treatment. Conclusion Vimentin and CML should be useful markers for cell senescence, as well as for evaluating the level of aging. Also, targeting increased vimentin expression and its advanced glycation end products could present a target for the treatment of skin aging.