Regulation of the endothelial cell urokinase-type plasminogen activator receptor. Evidence for cyclic AMP-dependent and protein kinase C-dependent pathways.
Regulation of the endothelial cell urokinase-type plasminogen activator receptor. Evidence for cyclic AMP-dependent and protein kinase C-dependent pathways.
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内皮细胞尿激酶型纤溶酶原激活剂受体的调节。
DOI：
10.1161/01.res.72.2.330
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发表时间：
1993
影响因子：
20.1
通讯作者：
Cines,DB
中科院分区：
文献类型：
--
作者：
Langer,DJ;Kuo,A;Kariko,K;Ahuja,M;Klugherz,BD;Ivanics,KM;Hoxie,JA;Williams,WV;Liang,BT;Cines,DB
尿激酶型纤溶酶原激活物（u-PA）与内皮细胞表面的特异性受体（u-PAR）的结合有助于调节纤溶酶依赖性过程，如纤维蛋白溶解和血管生成。我们研究了提高细胞内cAMP水平和/或激活蛋白激酶C对培养的人脐静脉内皮细胞（HUVEC）u-PAR表达的影响。孵育的HUVEC与毛喉素刺激的时间和浓度依赖性的增加，在u-PAR的表达，测量的放射性标记的单链u-PA（scu-PA）的特异性结合的增加，并通过增加抗-u-PAR抗体的结合。当HUVEC与50 μ M毛喉素在37 ℃下孵育20小时时，u-PAR表达的最大增加（高于对照组81 +/- 11%，n = 11）与scu-PA受体亲和力的变化无关。当HUVEC与腺苷酸环化酶抑制剂脱氧腺苷酸（DAM）预孵育时，Forskolin的受体诱导被抑制。cAMP类似物8-溴腺苷3 '：5'-环一磷酸（50 mM）诱导受体表达的类似增加（高于对照128 +/-27%，n = 3）。毛喉素诱导一个单一的约1.4 kb的u-PAR信使RNA（mRNA）转录的表达在2小时内增加了约两倍。佛波醇肉豆蔻酸酯乙酸酯（PMA）也刺激了特定的scu-PA结合的时间和浓度依赖性增加。当HUVEC与10 nM PMA预孵育20小时时，观察到u-PAR表达的最大增加（比对照组高254 +/- 27%，n = 11）。PMA诱导的u-PAR被抑制时，HUVEC预孵育与放线菌酮或H7，但不受DAM。PMA诱导的u-PAR显示出对scu-PA的亲和力降低（Kd，14 +/-2 nM对3.6 +/-0.6 nM，p < 0.001; n = 8）。PMA刺激20小时导致一个单一的约1.4 kb的u-PAR mRNA转录物增加了6倍，在30分钟内可检测到增加的水平。共孵育的HUVEC与最佳浓度的毛喉素和PMA的20小时产生了一个完全添加剂增加u-PAR的表达在mRNA和蛋白质水平。这些数据表明，cAMP依赖性和蛋白激酶C依赖性蛋白激酶途径可以独立地调节u-PAR在人内皮细胞的表达。
Binding of urokinase-type plasminogen activator (u-PA) to specific receptors (u-PAR) on the surface of endothelial cells contributes to the regulation of plasmin-dependent processes such as fibrinolysis and angiogenesis. We studied the effect of raising intracellular levels of cyclic AMP (cAMP) and/or activating protein kinase C on the expression of u-PAR in cultured human umbilical vein endothelial cells (HUVEC). Incubation of HUVEC with forskolin stimulated a time- and concentration-dependent increase in the expression of u-PAR, measured both by an increase in the specific binding of radiolabeled single-chain u-PA (scu-PA) and by increased binding of anti-u-PAR antibodies. Maximal increase in u-PAR expression (81 +/- 11% above control, n = 11) was not associated with a change in receptor affinity for scu-PA when HUVEC were incubated for 20 hours at 37 degrees C with 50 microM forskolin. Receptor induction by forskolin was inhibited when HUVEC were preincubated with deoxyadenosine monophosphate (DAM), an inhibitor of adenylyl cyclase. A similar increase in receptor expression (128 +/- 27% above control, n = 3) was induced by the cAMP analogue 8-bromoadenosine 3':5'-cyclic monophosphate (50 mM). Forskolin induced an approximately twofold increase in the expression of a single approximately 1.4-kb u-PAR messenger RNA (mRNA) transcript within 2 hours. Phorbol myristate acetate (PMA) also stimulated a time- and concentration-dependent increase in specific scu-PA binding. The maximal increase in u-PAR expression (254 +/- 27% above control, n = 11) was observed when HUVEC were preincubated with 10 nM PMA for 20 hours. Induction of u-PAR by PMA was inhibited when HUVEC were preincubated with either cycloheximide or H7 but was unaffected by DAM. u-PAR induced by PMA showed a reduced affinity for scu-PA (Kd, 14 +/- 2 nM versus 3.6 +/- 0.6 nM, p < 0.001; n = 8). PMA stimulation for 20 hours resulted in a sixfold increase in a single approximately 1.4-kb u-PAR mRNA transcript, with increased levels detectable within 30 minutes. Coincubation of HUVEC with optimal concentrations of forskolin and PMA for 20 hours produced a fully additive increase in u-PAR expression at both the mRNA and protein levels. These data suggest that both cAMP-dependent and protein kinase C-dependent protein kinase pathways may independently regulate u-PAR expression in human endothelial cells.