Functional Deterioration of Endothelial Nitric Oxide Synthase after Focal Cerebral Ischemia
Functional Deterioration of Endothelial Nitric Oxide Synthase after Focal Cerebral Ischemia
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DOI：
10.1038/jcbfm.2013.112
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发表时间：
2013-07
影响因子：
6.3
通讯作者：
Y. Yagita;K. Kitagawa;N. Oyama;T. Yukami;A. Watanabe;Tsutomu Sasaki;H. Mochizuki
中科院分区：
文献类型：
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作者：
Y. Yagita;K. Kitagawa;N. Oyama;T. Yukami;A. Watanabe;Tsutomu Sasaki;H. Mochizuki
内皮型一氧化氮合酶（eNOS）功能障碍与脑缺血后继发性损伤及病变扩大有关。迄今为止，很少有关于eNOS监管系统的化学后改变的报道。本研究的目的是阐明脑缺血后eNOS表达、Ser1177磷酸化和单体形成。雄性Wistar大鼠一过性局灶性脑缺血。内皮型一氧化氮合酶信使RNA （mRNA）和蛋白表达在缺血性病变中增加约8倍。在脑中动脉核心，缺血后6小时eNOS-Ser1177磷酸化升高；然而，缺血24小时后观察到eNOS-Ser1177磷酸化下降约90%，并持续到缺血后至少7天。缺血后24和48 h内皮型一氧化氮合酶单体形成增加（P<0.05），蛋白质硝化与单体化同步进行。为了评估神经保护剂对eNOS功能障碍的影响，我们评估了法舒地尔（一种rho激酶抑制剂）对eNOS磷酸化和二聚化的影响。法舒地尔化疗后抑制病变扩大、去磷酸化和eNOS单体形成。结论：脑缺血后eNOS功能恶化。rho激酶抑制剂可以减少缺血性脑损伤的扩展和eNOS功能障碍。
Endothelial nitric oxide synthase (eNOS) dysfunction is related to secondary injury and lesion expansion after cerebral ischemia. To date, there are few reports about postischemic alterations in the eNOS regulatory system. The purpose of the present study was to clarify eNOS expression, Ser1177 phosphorylation, and monomer formation after cerebral ischemia. Male Wistar rats were subjected to transient focal cerebral ischemia. Endothelial nitric oxide synthase messenger RNA (mRNA) and protein expression increased ~ 8-fold in the ischemic lesion. In the middle cerebral artery core, eNOS-Ser1177 phosphorylation increased 6 hours after ischemia; however, there was an approximately 90% decrease in eNOS-Ser1177 phosphorylation observed 24 hours after ischemia that continued until at least 7 days after ischemia. Endothelial nitric oxide synthase monomer formation also increased 24 and 48 hours after ischemia (P<0.05), and protein nitration progressed in parallel with monomerization. To assess the effect of a neuroprotective agent on eNOS dysfunction, we evaluated the effect of fasudil, a Rho-kinase inhibitor, on eNOS phosphorylation and dimerization. Postischemic treatment with fasudil suppressed lesion expansion and dephosphorylation and monomer formation of eNOS. In conclusion, functional deterioration of eNOS progressed after cerebral ischemia. Rho-kinase inhibitors can reduce ischemic lesion expansion as well as eNOS dysfunction in the ischemic brain.