Nonmuscle myosin light-chain kinase deficiency attenuates atherosclerosis in apolipoprotein E-deficient mice via reduced endothelial barrier dysfunction and monocyte migration.
Nonmuscle myosin light-chain kinase deficiency attenuates atherosclerosis in apolipoprotein E-deficient mice via reduced endothelial barrier dysfunction and monocyte migration.
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DOI：
10.1161/circulationaha.110.988915
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发表时间：
2011-07-05
期刊：
影响因子：
37.8
通讯作者：
Yuan SY
中科院分区：
文献类型：
--
作者：
Sun C;Wu MH;Yuan SY
内皮功能障碍和单核细胞迁移是动脉粥样硬化发病机制中的关键事件。非肌肉肌球蛋白轻链激酶(NmMLCK)是内皮细胞中主要的MLCK亚型，已被证明通过改变内皮细胞屏障功能而参与血管炎症。然而，它对动脉粥样硬化形成的影响尚不清楚。我们研究了nmMLCK在喂养致动脉粥样硬化饲料12周的载脂蛋白E缺陷(apoE−/−)小鼠动脉粥样硬化病变中的作用。组织病理学检查显示，nmMLCK缺陷(apoE−/−nmmlck−/−)可使主动脉病变面积缩小53%，脂质含量减少44%，巨噬细胞沉积减少40%。Western blotting和逆转录聚合酶链式反应显示nmMLCK在主动脉内皮细胞和外周血单核细胞中均有表达。跨内皮细胞电阻测定表明，nmMLCK缺乏可减轻凝血酶、oxLDL和肿瘤坏死因子-α引起的内皮屏障功能障碍。在单核细胞中，nmMLCK缺乏减少了单核细胞对趋化因子MCP-1的迁移。进一步的机制研究表明，nmMLCK通过肌球蛋白轻链(MLC)磷酸化偶联和非偶联途径发挥作用，后者涉及Src信号转导。此外，通过基因沉默、定点突变或药物抑制来耗尽src，可显著减轻nmMLCK依赖的内皮屏障功能障碍和单核细胞迁移。NmMLCK通过调节内皮屏障功能和单核细胞迁移参与动脉粥样硬化的形成，其机制不仅涉及到激酶介导的MLC磷酸化，而且还涉及到Src的激活。
Endothelial dysfunction and monocyte migration are key events in the pathogenesis of atherosclerosis. Non-muscle myosin light-chain kinase (nmMLCK), the predominant MLCK isoform in endothelial cells, has been shown to contribute to vascular inflammation by altering endothelial barrier function. However, its impact on atherogenesis remains unknown. We investigated the role of nmMLCK in the development of atherosclerotic lesions in apolipoprotein E-deficient (apoE−/−) mice fed an atherogenic diet for 12 weeks. Histopathological examination demonstrated that nmMLCK deficiency (apoE−/− nmmlck−/−) reduced the size of aortic lesions by 53%, lipid contents by 44% and macrophage deposition by 40%. Western blotting and reverse-transcription polymerase chain reaction revealed the expression of nmMLCK in aortic endothelial cells and peripheral blood monocytes. Measurements of transendothelial electric resistance indicated that nmMLCK deficiency attenuated endothelial barrier dysfunction caused by thrombin, oxLDL and TNF-α. In monocytes, nmMLCK deficiency reduced their migration in response to the chemokine MCP-1. Further mechanistic studies showed that nmMLCK acted through both myosin light chain (MLC) phosphorylation-coupled and -uncoupled pathways; the latter involved Src signaling. Moreover, depletion of Src via gene silencing, site-specific mutagenesis or pharmacological inhibition of Src greatly attenuated nmMLCK-dependent endothelial barrier dysfunction and monocyte migration. nmMLCK contributes to atherosclerosis by regulating endothelial barrier function and monocyte migration via mechanisms involving not only kinase-mediated MLC phosphorylation but also Src activation.