K.G. Jebsen Thrombosis and Expertise Center (TREC), Department of Clinical Medicine, UiT - The Arctic University of Norway, N-9037 Tromsø, Norway.
Division of Hematology/Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA.
Thromb Res. 2016 Nov;147:24-31. doi: 10.1016/j.thromres.2016.09.018. Epub 2016 Sep 17.
Bone morphogenetic protein (BMP) 7 is abundant in atherosclerotic plaques and increases monocyte pro-coagulant activity by enhancing tissue factor (TF) expression. While several members of the BMP superfamily are able to serve as chemotactic agents for monocytes, the role of BMP-7 in regulation of monocyte motility is not known.
To assess the effect of BMP-7 on adhesive and migratory properties of human monocytes.
Chemokinesis, adhesion, and transendothelial migration of BMP-7-treated THP-1 cells and human monocytes were analysed using live-cell imaging, orbital shear, and Boyden chamber assays. Surface presentation of β2 integrins and phosphorylation status of Akt & focal adhesion kinase (FAK) were studied by flow cytometry and Western blot.
High levels of BMP-7 protein were detectable in intimal regions of atherosclerotic plaques; BMP-7 significantly enhanced THP-1 and monocyte chemokinetic properties in vitro (1.21+0.01 and 1.76+0.21 fold increase in crawling distance, respectively). Under orbital shear, adhesion of monocytic cells to microvascular endothelial cell (MVEC) monolayers was also significantly increased by BMP-7 (3.89+1.56 and 2.57+0.97 fold over vehicle). Moreover, BMP-7 accelerated transendothelial migration of THP-1 cells and monocytes towards MCP-1 (5.91+0.88 and 2.96±0.65 fold increase, respectively). BMP-7 enhanced cell surface presentation of β2 integrins in the active conformation. Observed effects were determined to be Akt and FAK dependent, as shown by pharmacological inhibition.
BMP-7 directly upregulates adhesion and migration of human monocytic cells via activation of β2 integrins, Akt, and FAK. Our findings suggest that BMP-7 may serve as a novel contributor to atherogenesis.
骨形态发生蛋白 7（BMP7）在动脉粥样硬化斑块中含量丰富，通过增强组织因子（TF）的表达来增加单核细胞的促凝活性。虽然 BMP 超家族的几个成员能够作为单核细胞的趋化因子，但 BMP-7 调节单核细胞迁移的作用尚不清楚。
评估 BMP-7 对人单核细胞黏附及迁移特性的影响。
采用活细胞成像、轨道剪切和 Boyden 室分析检测 BMP-7 处理的 THP-1 细胞和人单核细胞的趋化性、黏附和穿越内皮迁移。通过流式细胞术和 Western blot 检测 β2 整合素的表面呈现和 Akt 和 focal adhesion kinase（FAK）的磷酸化状态。
在动脉粥样硬化斑块的内膜区域可检测到高水平的 BMP-7 蛋白；BMP-7 可显著增强 THP-1 和单核细胞的体外趋化特性（爬行距离分别增加 1.21±0.01 和 1.76±0.21 倍）。在轨道剪切下，BMP-7 也显著增加单核细胞与微血管内皮细胞（MVEC）单层的黏附（与对照相比分别增加 3.89+1.56 和 2.57+0.97 倍）。此外，BMP-7 加速了 THP-1 细胞和单核细胞向 MCP-1 的穿越内皮迁移（分别增加 5.91+0.88 和 2.96±0.65 倍）。BMP-7 增强了β2 整合素在活性构象中的细胞表面呈现。通过药理抑制证实，观察到的作用依赖于 Akt 和 FAK。
BMP-7 通过激活β2 整合素、Akt 和 FAK，直接上调人单核细胞的黏附和迁移。我们的研究结果表明，BMP-7 可能是动脉粥样形成的一个新的贡献者。
