Institute for Medicine and Engineering, Center for Bioinformatics, and Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA.
Proc Natl Acad Sci U S A. 2010 Jul 27;107(30):13450-5. doi: 10.1073/pnas.1002120107. Epub 2010 Jul 12.
A chronic proinflammatory state precedes pathological change in arterial endothelial cells located within regions of susceptibility to atherosclerosis. The potential contributions of regulatory microRNAs to this disequilibrium were investigated by artery site-specific profiling in normal adult swine. Expression of endothelial microRNA10a (miR-10a) was lower in the athero-susceptible regions of the inner aortic arch and aorto-renal branches than elsewhere. Expression of Homeobox A1 (HOXA1), a known miR-10a target, was up-regulated in the same locations. Endothelial transcriptome microarray analysis of miR-10a knockdown in cultured human aortic endothelial cells (HAEC) identified IkappaB/NF-kappaB-mediated inflammation as the top category of up-regulated biological processes. Phosphorylation of IkappaBalpha, a prerequisite for IkappaBalpha proteolysis and NF-kappaB activation, was significantly up-regulated in miR-10a knockdown HAEC and was accompanied by increased nuclear expression of NF-kappaB p65. The inflammatory biomarkers monocyte chemotactic protein 1 (MCP-1), IL-6, IL-8, vascular cell adhesion molecule 1 (VCAM-1), and E-selectin were elevated following miR-10a knockdown. Conversely, knockin of miR-10a (a conservative 25-fold increase) inhibited the basal expression of VCAM-1 and E-selectin in HAEC. Two key regulators of IkappaBalpha degradation--mitogen-activated kinase kinase kinase 7 (MAP3K7; TAK1) and beta-transducin repeat-containing gene (betaTRC)--contain a highly conserved miR-10a binding site in the 3' UTR. Both molecules were up-regulated by miR-10a knockdown and suppressed by miR-10a knockin, and evidence of direct miR-10a binding to the 3' UTR was demonstrated by luciferase assay. Comparative expression studies of endothelium located in athero-susceptible aortic arch and athero-protected descending thoracic aorta identified significantly up-regulated MAP3K7, betaTRC, phopho-IkappaBalpha, and nuclear p65 expression suggesting that the differential expression of miR-10a contributes to the regulation of proinflammatory endothelial phenotypes in athero-susceptible regions in vivo.
慢性炎症状态先于动脉内皮细胞发生病理性改变，而这些内皮细胞位于易发生动脉粥样硬化的区域内。本研究通过对正常成年猪的动脉部位进行特异性分析，研究了调节 microRNA 对这种失衡的潜在贡献。结果显示，在易发生动脉粥样硬化的主动脉弓内区域和肾动脉分支处，内皮细胞 microRNA10a（miR-10a）的表达低于其他部位。已知是 miR-10a 靶标的同源盒 A1（HOXA1）在相同位置上调表达。在培养的人主动脉内皮细胞（HAEC）中敲低 miR-10a 的内皮转录组微阵列分析确定，IκB/NF-κB 介导的炎症是上调的生物学过程的首要类别。IκBα的磷酸化是 IκBα蛋白水解和 NF-κB 激活的前提，在 miR-10a 敲低的 HAEC 中显著上调，并伴有 NF-κB p65 的核表达增加。单核细胞趋化蛋白 1（MCP-1）、IL-6、IL-8、血管细胞黏附分子 1（VCAM-1）和 E-选择素等炎症生物标志物在 miR-10a 敲低后升高。相反，miR-10a 的过表达（保守的 25 倍增加）抑制了 HAEC 中 VCAM-1 和 E-选择素的基础表达。IκBα降解的两个关键调节因子——丝裂原活化蛋白激酶激酶激酶 7（MAP3K7；TAK1）和β-转导重复基因（βTRC）——在 3'UTR 中含有一个高度保守的 miR-10a 结合位点。这两种分子都被 miR-10a 敲低上调，并被 miR-10a 过表达抑制，通过荧光素酶测定证明了直接 miR-10a 结合 3'UTR。在易发生动脉粥样硬化的主动脉弓和动脉保护的降主动脉中的内皮细胞的比较表达研究表明，MAP3K7、βTRC、磷酸化的 IκBα和核 p65 的表达显著上调，这表明 miR-10a 的差异表达有助于调节体内易发生动脉粥样硬化的区域中促炎的内皮表型。
