Differential regulation of thrombospondin-1 and fibronectin by angiotensin II receptor subtypes in cultured endothelial cells
Differential regulation of thrombospondin-1 and fibronectin by angiotensin II receptor subtypes in cultured endothelial cells
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DOI：
10.1016/s0008-6363(01)00345-5
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发表时间：
2001-09-01
影响因子：
10.8
通讯作者：
Unger, T
中科院分区：
文献类型：
--
作者：
Fischer, JW;Stoll, M;Unger, T
目的：血管紧张素Ⅱ（Angiotensin Ⅱ，ANG Ⅱ）可通过AT（1）和AT（2）受体调节多种细胞的增殖。在本研究中，我们研究了血管紧张素AT（1）和AT（2）受体对内皮细胞（EC）DNA合成以及细胞外基质（ECM）组分血小板反应蛋白-1（TSP-1）和纤连蛋白（FN）表达的影响。方法：采用大鼠心脏微血管内皮细胞（CEC）和牛主动脉大血管内皮细胞（BAEC）进行实验。在第2代和第3代细胞中进行实验，通过结合研究、北方分析或RT-PCR验证AT（1）和AT（2）受体的表达。通过加入25 ng/ml bFGF刺激静止的大鼠CEC和BAEC增殖，同时在16 h后加入ANG II（10（-7）M）和选择性ANG II受体拮抗剂Losartan（10（-5）M）和PD 123177（10（-6）M）或AT激动剂CGP 42112 A（10（-7）M）。结果：ANG Ⅱ可诱导BAEC DNA合成量的减少，并呈剂量依赖性。加入AT（2）受体拮抗剂PD 123177（10（-6）M）可阻止ANG II的这种抑制作用，表明DNA合成的抑制是由AT（2）受体介导的。在氯沙坦的存在下，刺激，CEC和BAEC，与ANG II导致TSP-1的mRNA水平显着增加，这是最大的3和6小时之间在大鼠CEC和9小时后在BAEC。此外，TSP-1明显被AT（2）激动剂CGP 42112 A诱导。与此相反，用AT（2）受体拮抗剂PD 123177（10（-6）M）阻断AT（2）受体，在刺激后9小时，FN mRNA表达明显下调。结论：目前的结果表明，血管紧张素Ⅱ受体亚型AT（2）介导的生长抑制在大血管EC类似于以前已经显示在微血管大鼠EC和AT（2）受体介导的重塑内皮细胞外基质的TSP-1的表达在大血管和微血管内皮细胞。(C)2001 Elsevier Science B. V.保留所有权利。
Objectives: Angiotensin II (ANG II) can modulate cellular proliferation in various cell types via AT(1) and AT(2), receptors. In the present study, we investigated the effect of the angiotensin AT(1) and AT(2) receptors on DNA-synthesis as well as on the expression of the extracellular matrix (ECM) components, thrombospondin-1 (TSP-1) and fibronectin (FN) in endothelial cells (EC). Methods: The experiments were performed in microvascular EC derived from rat heart (CEC) and macrovascular EC derived from bovine aorta (BAEC). The experiments were performed in cells of the second and third passage and the expression of AT(1) and AT(2) receptors was verified by binding studies, Northern analysis or RT-PCR. Quiescent rat CEC and BAEC were stimulated to proliferate by the addition of 25 ng/ml bFGF, while ANG II (10(-7) M) and the selective ANG II receptor antagonists, Losartan (10(-5) M) and PD123177 (10(-6) M) or the AT, agonist, CGP42112A (10(-7) M) were added 16 h later. Results: ANG II induced a dose-dependent decrease of DNA-synthesis in BAEC measured by [H-3]-thymidine incorporation. This inhibitory effect of ANG II was prevented by the addition of the AT(2) receptor antagonist PD123177 (10(-6) M), demonstrating, that the inhibition of DNA synthesis is mediated by the AT(2) receptor. In the presence of Losartan, stimulation of both, CEC and BAEC, with ANG II resulted in a marked increase of TSP-1 mRNA levels, which was maximal between 3 and 6 h in rat CEC and after 9 h in BAEC. In addition, TSP-1 was clearly induced by the AT(2) agonist CGP42112A. In contrast, blockade of the AT(2) receptor by the selective AT(2) antagonist, PD123177 (10(-6) M), resulted in a pronounced down regulation of FN mRNA 9 h after the stimulation. Conclusions: The present results suggest that the ANG II receptor subtype AT(2) mediates growth inhibition in macrovascular EC similar to what has been shown before in microvascular rat EC and that AT(2) receptors mediates remodeling of the endothelial ECM by upregulation of TSP-1 expression in both macro- and micro-vascular endothelial cells. (C) 2001 Elsevier Science B.V. All rights reserved.