Background Urotensin Ⅱ （UⅡ） is a new vasoconstrictive peptide that may activate the adventitial fibroblasts.Transforming growth factor-β1 （TGF-β1） is an important factor that could induce the phenotypical tran...Background Urotensin Ⅱ （UⅡ） is a new vasoconstrictive peptide that may activate the adventitial fibroblasts.Transforming growth factor-β1 （TGF-β1） is an important factor that could induce the phenotypical transdifferentiation of adventitial fibroblasts. This study aimed to explore whether TGF-β1 is involved in UⅡ-induced phenotypic differentiation of adventitial fibroblasts from rat aorta.Methods Adventitial fibroblasts were prepared by the explant culture method. TGF-β1 protein secretion from the cells was determined by enzyme-linked immunosorbent assay （ELISA）. The mRNA and protein expression of α-smooth nuscle actin （α-SM-actin）, the marker of phenotypic differentiation from fibroblasts to myofibroblasts, were determined using real-time quantitative RT-PCR （real-time RT-PCR） and Western blotting, respectively.Results UⅡ stimulated the secretion of TGF-β1 in cultured adventitial fibroblasts in a time-dependent manner. The secretion reached a peak at 24 hours, was higher by 69.8% （P ＜0.01）, than the control group. This effect was also concentration dependent. Maximal stimulation was reached at 10-8 mol/L of UⅡ （P ＜0.01）, which was increased by 59.9%,compared with in the control group （P ＜0.01）. The secretion of TGF-β1 induced by UⅡ was significantly blocked by SB-710411 （10-7 mol/L）, a specific antagonist of UⅡ receptor. In addition, both UⅡ （10-8 mol/L） and TGF-β1 significantly stimulated α-SM-actin mRNA and protein expression. Moreover, the α-SM-actin induced by UⅡ was inhibited by the specific neutralizing antibody （20 μg/ml） of TGF-β1, while the α-SM-actin expression stimulated by TGF-β1 （20 ng/ml）was inhibited by SB-710411 （10-7 mol/L）, the UⅡ receptor antagonist.Conclusion This study suggests that UⅡ could induce TGF-β1 secretion in adventitial fibroblasts via UT activation, and TGF-β1 might be involved in phenotypic differentiation from adventitial fibroblasts into myofibroblasts induced by UⅡ, and TGF-β1 signaling might be one of the important pathways by which UⅡ is involved in vascular fibrosis.展开更多
Background Urotensin Ⅱ （Ull）,a potent vasoconstrictive peptide,is able to stimulate phenotypic differentiation of adventitial fibroblasts.This study aimed to determine the effect of UII on monocyte chemoattractant ...Background Urotensin Ⅱ （Ull）,a potent vasoconstrictive peptide,is able to stimulate phenotypic differentiation of adventitial fibroblasts.This study aimed to determine the effect of UII on monocyte chemoattractant protein-1 （MCP1） expression in rat aortic adventitial fibroblasts,so as to explore possible mechanisms in the development of vascular inflammation.Methods Growth-arrested adventitial fibroblasts were incubated in serum-free medium with UII （1010-10-7 mol/L） and inhibitors of signal transduction pathways for 1 to 24 hours.MCP-1 mRNA and protein expression and secretion were determined by RT-PCR,Western blotting analysis and enzyme-linked immunosorbent assay （ELISA）,respectively.Results UII dose-and time-dependently promoted MCP-1 mRNA and protein expression and secretion in cells,with maximal effect at 10-8 mol/L at 3 hours for mRNA expression,24 hours for protein expression in the cells,and 12 hours for protein secretion from the cells.Furthermore,the UII effects were significantly inhibited by treatment with its receptor antagonist SB710411,Rho kinase inhibitor Y27632,protein kinase C （PKC） inhibitor H7,mitogen-activated protein kinase inhibitor PD98059,calcineurin inhibitor cyclosporine A,and the Ca2＋channel blocker nicardipine.Conclusion UII may stimulate MCP-1 expression in rat aortic adventitial fibroblasts through its receptor and Rho kinase,PKC,mitogen-activated protein kinase,calcineurin and Ca2＋ channel signal transduction,thus contributing to adventitial inflammation.展开更多
基金This project was supported by grants from the National Natural Science Foundation of China （No. 30470730, No. 30971273）, the Natural Science Foundation of Guangdong Province （No. 9151051501000016）, and the Medical Scientific Research Foundation of Guangdong Province, China （No. A2007425）.
文摘Background Urotensin Ⅱ （UⅡ） is a new vasoconstrictive peptide that may activate the adventitial fibroblasts.Transforming growth factor-β1 （TGF-β1） is an important factor that could induce the phenotypical transdifferentiation of adventitial fibroblasts. This study aimed to explore whether TGF-β1 is involved in UⅡ-induced phenotypic differentiation of adventitial fibroblasts from rat aorta.Methods Adventitial fibroblasts were prepared by the explant culture method. TGF-β1 protein secretion from the cells was determined by enzyme-linked immunosorbent assay （ELISA）. The mRNA and protein expression of α-smooth nuscle actin （α-SM-actin）, the marker of phenotypic differentiation from fibroblasts to myofibroblasts, were determined using real-time quantitative RT-PCR （real-time RT-PCR） and Western blotting, respectively.Results UⅡ stimulated the secretion of TGF-β1 in cultured adventitial fibroblasts in a time-dependent manner. The secretion reached a peak at 24 hours, was higher by 69.8% （P ＜0.01）, than the control group. This effect was also concentration dependent. Maximal stimulation was reached at 10-8 mol/L of UⅡ （P ＜0.01）, which was increased by 59.9%,compared with in the control group （P ＜0.01）. The secretion of TGF-β1 induced by UⅡ was significantly blocked by SB-710411 （10-7 mol/L）, a specific antagonist of UⅡ receptor. In addition, both UⅡ （10-8 mol/L） and TGF-β1 significantly stimulated α-SM-actin mRNA and protein expression. Moreover, the α-SM-actin induced by UⅡ was inhibited by the specific neutralizing antibody （20 μg/ml） of TGF-β1, while the α-SM-actin expression stimulated by TGF-β1 （20 ng/ml）was inhibited by SB-710411 （10-7 mol/L）, the UⅡ receptor antagonist.Conclusion This study suggests that UⅡ could induce TGF-β1 secretion in adventitial fibroblasts via UT activation, and TGF-β1 might be involved in phenotypic differentiation from adventitial fibroblasts into myofibroblasts induced by UⅡ, and TGF-β1 signaling might be one of the important pathways by which UⅡ is involved in vascular fibrosis.
基金This project was supported by grants from National Natural Science Foundation of China （No. 30971273 and No. 81270223） and Natural Science Foundation of Guangdong Province of China （No. 9151051501000016 and No. S2011010000450）.
文摘Background Urotensin Ⅱ （Ull）,a potent vasoconstrictive peptide,is able to stimulate phenotypic differentiation of adventitial fibroblasts.This study aimed to determine the effect of UII on monocyte chemoattractant protein-1 （MCP1） expression in rat aortic adventitial fibroblasts,so as to explore possible mechanisms in the development of vascular inflammation.Methods Growth-arrested adventitial fibroblasts were incubated in serum-free medium with UII （1010-10-7 mol/L） and inhibitors of signal transduction pathways for 1 to 24 hours.MCP-1 mRNA and protein expression and secretion were determined by RT-PCR,Western blotting analysis and enzyme-linked immunosorbent assay （ELISA）,respectively.Results UII dose-and time-dependently promoted MCP-1 mRNA and protein expression and secretion in cells,with maximal effect at 10-8 mol/L at 3 hours for mRNA expression,24 hours for protein expression in the cells,and 12 hours for protein secretion from the cells.Furthermore,the UII effects were significantly inhibited by treatment with its receptor antagonist SB710411,Rho kinase inhibitor Y27632,protein kinase C （PKC） inhibitor H7,mitogen-activated protein kinase inhibitor PD98059,calcineurin inhibitor cyclosporine A,and the Ca2＋channel blocker nicardipine.Conclusion UII may stimulate MCP-1 expression in rat aortic adventitial fibroblasts through its receptor and Rho kinase,PKC,mitogen-activated protein kinase,calcineurin and Ca2＋ channel signal transduction,thus contributing to adventitial inflammation.
