Objective To evaluate activator protein 1(AP 1) mediated mechanisms in thrombin induced qlasmino^gen activator inhibitor 1 (PAI 1) expression in cultured human glomerular mesangial cells (MCs) Methods Electrop...Objective To evaluate activator protein 1(AP 1) mediated mechanisms in thrombin induced qlasmino^gen activator inhibitor 1 (PAI 1) expression in cultured human glomerular mesangial cells (MCs) Methods Electrophoretic mobility shift assay (EMSA) was employed to assess AP 1 DNA binding activity, and Western blot hybridization was used for quantification of c fos and c jun, two subunits of AP 1 dimers PAI 1 activity and mRNA expression were analysed by the fibrin plate assay and Northern hybridization, respectively Results Thrombin concentration enhanced PAI 1 activity in the supernatant and stimulated PAI 1 mRNA expression in cultured MCs PAI 1 activity was blocked by hirudin, a specific inhibitor of thrombin Further study demonstrated that thrombin promoted AP 1 DNA binding activity but exerted little effect on c fos or c jun Curcumin (AP 1 inhibitor), staurosporine (PKC inhibitor), and genistein (PTK inhibitor) all reduced AP 1 mediated PAI 1 mRNA expression induced by thrombin in cultured MCs Conclusion The present study indicates that in cultured human MCs, thrombin stimulates PAI 1 expression through an AP 1 signal pathway, which may be mediated by PKC and PTK展开更多
文摘Objective To evaluate activator protein 1(AP 1) mediated mechanisms in thrombin induced qlasmino^gen activator inhibitor 1 (PAI 1) expression in cultured human glomerular mesangial cells (MCs) Methods Electrophoretic mobility shift assay (EMSA) was employed to assess AP 1 DNA binding activity, and Western blot hybridization was used for quantification of c fos and c jun, two subunits of AP 1 dimers PAI 1 activity and mRNA expression were analysed by the fibrin plate assay and Northern hybridization, respectively Results Thrombin concentration enhanced PAI 1 activity in the supernatant and stimulated PAI 1 mRNA expression in cultured MCs PAI 1 activity was blocked by hirudin, a specific inhibitor of thrombin Further study demonstrated that thrombin promoted AP 1 DNA binding activity but exerted little effect on c fos or c jun Curcumin (AP 1 inhibitor), staurosporine (PKC inhibitor), and genistein (PTK inhibitor) all reduced AP 1 mediated PAI 1 mRNA expression induced by thrombin in cultured MCs Conclusion The present study indicates that in cultured human MCs, thrombin stimulates PAI 1 expression through an AP 1 signal pathway, which may be mediated by PKC and PTK
