AT2-Receptor activation regulates myocardial eNOS expression via the calcineurin-NF-AT pathway
AT2-Receptor activation regulates myocardial eNOS expression via the calcineurin-NF-AT pathway
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DOI：
10.1096/fj.02-0321fje
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发表时间：
2002-12-01
期刊：
影响因子：
4.8
通讯作者：
Neyses, L
中科院分区：
文献类型：
--
作者：
Ritter, O;Schuh, K;Neyses, L
血管紧张素II （AngII）刺激大鼠心肌细胞使eNOS蛋白表达增加3.3倍。这被环孢素A （CsA）阻断。抑制AT(1)受体不降低血管内皮细胞介导的eNOS蛋白表达，而AT(2)刺激使其表达增加2.4倍，而AT(2)抑制其表达。在基因缺失AT(2)受体（AT(2)-KO）的小鼠中证实了AT(2)-受体对eNOS表达的调节作用。在凝胶移位实验中，1.6 kb eNOS启动子片段中的两个假定的NF-AT位点显示NF-AT结合，并被NF-AT2（-c1）特异性抗体超移位。用AngII或特异性AT(2)受体激动剂刺激转染细胞可导致eNOS启动子活性显著增加，该活性被CsA、MCIP1和上游NF-AT位点突变阻断。结论：1)体外和体内心肌血管刺激均伴有eNOS表达升高。2)这种作用由钙调神经磷酸酶途径介导，并由AT(2)受体诱导。3)这些结果确定钙调磷酸酶/NF-AT/eNOS通路是心肌AT(2)受体激活的下游效应因子。
Stimulation of rat cardiomyocytes with angiotensin II (AngII) increased eNOS protein expression 3.3-fold. This was blocked by Cyclosporin A (CsA). Inhibition of the AT(1)-receptor did not reduce AngII-mediated eNOS protein expression, whereas AT(2) stimulation increased it 2.4-fold and AT(2) inhibition suppressed it. The modulatory effects of the AT(2)-receptor on eNOS expression was confirmed in mice with a genetic deletion of the AT(2)-receptor (AT(2)-KO). In gel shift assays two putative NF-AT sites in a 1.6 kb eNOS promoter fragment showed NF-AT binding and a supershift by NF-AT2(-c1)-specific antibodies. Stimulation of transfected cells with AngII or specific AT(2)-receptor agonists resulted in a significant increase in eNOS promoter activity, which was blocked by CsA, MCIP1, and mutation of an upstream NF-AT site. Conclusion: 1) AngII-stimulation of the myocardium, both in vivo and in vitro, is accompanied by increased expression of eNOS. 2) This effect is mediated by the calcineurin pathway and is induced by the AT(2)-receptor. 3) These results define a calcineurin/NF-AT/eNOS pathway as downstream effector of AT(2)-receptor activation in the myocardium.