Department of Biomedical Engineering, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
Proc Natl Acad Sci U S A. 2013 Aug 20;110(34):13944-9. doi: 10.1073/pnas.1300651110. Epub 2013 Aug 5.
Monocyte recruitment to inflamed arterial endothelium initiates plaque formation and drives progression of atherosclerosis. Three distinct monocyte subsets are detected in circulation (CD14(++)CD16(-), CD14(++)CD16(+), and CD14(+)CD16(++)), and each may play distinct roles during atherogenesis and myocardial infarction. We studied a range of subjects that included otherwise healthy patients with elevated serum triglyceride levels to patients presenting with acute myocardial infarction. Our objective was to correlate an individual's risk with the activation state of each monocyte subset as a function of changes in adhesion receptor expression using flow cytometric quantitation of integrins and l-selectin membrane expression. A microfluidic-based laboratory-on-a-chip was developed to quantify the adhesion efficiency of monocytes sheared in whole blood on vascular cell adhesion molecule-1, while characterizing adhesion receptor expression and topography on captured monocytes. CD14(++)CD16(+) monocytes adhered with sevenfold higher efficiency than other subsets, and in patients with myocardial infarction the capture efficiency of this subset was double that for healthy subjects. In patients with hypertriglyceridemia, this increase in monocyte adhesion was attributable to CD14(++)CD16(+) uptake of triglyceride-rich lipoproteins and subsequent signaling via a Phospholipase C-dependent mechanism to increase CD11c expression, very late antigen-4 function, and integrin coclustering within focal adhesive sites on vascular cell adhesion molecule-1. In summary, we introduce a unique laboratory-on-a-chip method for quantifying the activation state of monocyte subsets. These experiments reveal that CD11c/CD18 is an inducible integrin whose expression correlates with a monocyte inflammatory state in subjects at risk for atherogenesis and in patients with myocardial infarction.
单核细胞募集到发炎的动脉内皮细胞，启动斑块形成，并推动动脉粥样硬化的进展。在循环中检测到三种不同的单核细胞亚群（CD14(++)CD16(-)、CD14(++)CD16(+)和 CD14(+)CD16(++)），并且在动脉粥样形成和心肌梗死过程中，每一种可能都发挥着独特的作用。我们研究了一系列对象，包括血清甘油三酯水平升高的健康患者，到患有急性心肌梗死的患者。我们的目标是将个体的风险与每个单核细胞亚群的激活状态相关联，作为整合素和 l-选择素膜表达变化的功能，使用流式细胞术定量测定。开发了一种基于微流控的实验室芯片，以量化在血管细胞粘附分子-1上剪切全血中单核细胞的粘附效率，同时对捕获的单核细胞上粘附受体的表达和拓扑结构进行特征化。CD14(++)CD16(+)单核细胞的粘附效率比其他亚群高七倍，在心肌梗死患者中，该亚群的捕获效率是健康受试者的两倍。在高甘油三酯血症患者中，这种单核细胞粘附的增加归因于 CD14(++)CD16(+)摄取富含甘油三酯的脂蛋白，随后通过磷脂酶 C 依赖性机制进行信号传递，增加 CD11c 表达、非常晚抗原-4 功能以及整合素在血管细胞粘附分子-1上的焦点粘附部位的共聚类。总之，我们引入了一种独特的实验室芯片方法，用于定量测定单核细胞亚群的激活状态。这些实验表明，CD11c/CD18 是一种诱导型整合素，其表达与动脉粥样形成风险患者和心肌梗死患者的单核细胞炎症状态相关。
