Harris M Brennan, Blackstone Michele A, Sood Sarika G, Li Chunying, Goolsby Jonathan M, Venema Virginia J, Kemp Bruce E, Venema Richard C
Department of Pediatrics, Medical College of Georgia, Augusta, Georgia 30912-2500, USA.
Am J Physiol Heart Circ Physiol. 2004 Aug;287(2):H560-6. doi: 10.1152/ajpheart.00214.2004. Epub 2004 Apr 15.
3-Hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitors, statins, provide beneficial effects independent of their lipid-lowering effects. One beneficial effect appears to involve acute activation of endothelial nitric oxide (NO) synthase (eNOS) and increased NO release. However, the mechanism of acute statin-stimulated eNOS activation is unknown. Therefore, we hypothesized that eNOS activation may be coupled to altered eNOS phosphorylation. Bovine aortic endothelial cells (BAECs), passages 2-6, were treated with either lovastatin or pravastatin from 0 to 30 min. eNOS phosphorylation was examined by Western blot by use of phosphospecific antibodies for Ser-1179, Ser-635, Ser-617, Thr-497, and Ser-116. Statin stimulation of BAECs increased eNOS phosphorylation at Ser-1179 and Ser-617, which was blocked by the phosphatidylinositol 3-kinase (PI3-kinase)/Akt inhibitor wortmannin, and at Ser-635, which was blocked by the protein kinase A (PKA) inhibitor KT-5720. Statin treatment of BAECs transiently increased NO release by fourfold, measured by cGMP accumulation, and was attenuated by N-nitro-l-arginine methyl ester, wortmannin, and KT-5720 but not by mevalonate. In conclusion, these data demonstrate that eNOS is acutely activated by statins independent of HMG-CoA reductase inhibition and that in addition to Ser-1179, eNOS phosphorylation at Ser-635 and Ser-617 through PKA and Akt, respectively, may explain, in part, a mechanism by which eNOS is activated in response to acute statin treatment.
3-羟基-3-甲基戊二酰辅酶A（HMG）-辅酶A还原酶抑制剂，即他汀类药物，具有独立于其降脂作用的有益效果。其中一种有益效果似乎涉及内皮型一氧化氮（NO）合酶（eNOS）的急性激活和NO释放增加。然而，他汀类药物急性刺激eNOS激活的机制尚不清楚。因此，我们推测eNOS激活可能与eNOS磷酸化改变有关。用洛伐他汀或普伐他汀处理传代2至6代的牛主动脉内皮细胞（BAECs）0至30分钟。通过使用针对Ser-1179、Ser-635、Ser-617、Thr-497和Ser-116的磷酸特异性抗体，通过蛋白质印迹法检测eNOS磷酸化。他汀类药物对BAECs的刺激增加了Ser-1179和Ser-617处的eNOS磷酸化，这被磷脂酰肌醇3激酶（PI3激酶）/Akt抑制剂渥曼青霉素阻断，以及Ser-635处的eNOS磷酸化，这被蛋白激酶A（PKA）抑制剂KT-5720阻断。用环磷酸鸟苷（cGMP）积累测量，他汀类药物处理BAECs可使NO释放瞬时增加四倍，并且被N-硝基-L-精氨酸甲酯、渥曼青霉素和KT-5720减弱，但不被甲羟戊酸减弱。总之，这些数据表明，他汀类药物可独立于HMG-CoA还原酶抑制作用急性激活eNOS，并且除了Ser-1179外，分别通过PKA和Akt在Ser-635和Ser-617处的eNOS磷酸化可能部分解释了eNOS在急性他汀类药物治疗反应中被激活的机制。
