Abstract: Luo Limin*, Li Jun, Liu Han, Liu Jinsong, Dong Xiao, Dang Shuyi. *Department of Dermatology, Dongfeng General Hospital, Hubei University of Medicine, Shiyan 442000, Hubei, China Corresponding author: Li Jun, Email: stulijun@sina.com 【Abstract】 Objective To evaluate the effect of a vasoactive substance urotensin Ⅱ on the expression of typeⅠ collagen and migration of human skin fibroblasts, and to explore the underlying mechanisms of signal transduction. Methods Fibroblasts were isolated from human foreskin tissues and subjected to primary culture. After a series of subculture, fibroblasts were classified into several groups to be treated with different concentrations （10－10 to 10－6 mol/L） of urotensin Ⅱ for 24 hours, urotensin Ⅱ of 10－8 mol/L for different durations （0, 4, 12, 24 hours）, or pretreated with PD98059 （a mitogen-activated protein kinase kinase inhibitor）, nicardipine （a calcium channel blocker） and ciclosporin （a calcineurin inhibitor） of 10－5 mol/L respectively for 30 minutes followed by treatment with urotensin Ⅱ of 10－8 mol/L for 24 hours. The cells receiving no treatment served as the control. Subsequently, enzyme-linked immunosorbent assay was performed to determine the level of urotensin Ⅱ in the supernatant of fibroblasts, and Transwell assay to estimate the migration activity of fibroblasts. Statistical analysis was carried out by t test and analysis of variance. Results Urotensin Ⅱ promoted the expression of typeⅠ collagen in a time- and concentration-dependent manner. The level of typeⅠ collagen was increased by 21.2% （P > 0.05）, 52.2% （P < 0.05）, 84.4% （P < 0.05）, 83.6% （P < 0.05） and 77.1% （P < 0.05） in the supernatant of fibroblasts treated with 10－10, 10－9, 10－8, 10－7 and 10－6 mol/L of urotensin Ⅱ for 24 hours respectively, by 23.2% （P > 0.05）, 69.5% （P < 0.05） and 84.1% （P < 0.05） in the supernatant of fibroblasts treated with urotensin Ⅱ of 10－8 mol/L for 4, 12 and 24 hours respectively, compared with the untreated control fibroblasts. The migration activity was markedly enhanced in fibroblasts treated with urotensin Ⅱ of 10－8 mol/L for 24 hours compared with the control fibroblasts （P < 0.05）. PD98059, nicardipine and cyclosporin A inhibited the secretion of typeⅠ collagen by 18.2%, 15.9% and 19.7% respectively, and suppressed the migration of fibroblasts by 38.3% （P < 0.05）, 20.7% （P < 0.05） and 81.4% （P < 0.05） respectively in the groups receiving pretreatment compared with those treated with urotensin Ⅱ alone. Conclusions Urotensin Ⅱ can promote the secretion of typeⅠ collagen by and migration of fibroblasts, which may be realized through the Ca2+, calmodulin kinase, and mitogen-activated protein kinase pathways.

Key words: Vasoactive intestinal peptide, Urotensin Ⅱ, Cell movement, Fibroblasts, Collagen typeⅠ