Davis Heart & Lung Research Institute, The Ohio State University College of Medicine, Columbus, USA.
Arterioscler Thromb Vasc Biol. 2012 Apr;32(4):962-70. doi: 10.1161/ATVBAHA.111.244509. Epub 2012 Feb 2.
Myeloid-related protein (Mrp) 8/14 complex (is a highly expressed extracellularly secreted protein, implicated in atherosclerosis. In this study, we evaluated the feasibility of targeting Mrp in vivo through synthetic immuno-nanoprobes.
Anti-Mrp-14 and nonspecific IgG-conjugated gadolinium nanoprobes (aMrp-) were synthesized and characterized. Pharmacokinetics and vascular targeting via MRI of the formulations were assessed in vivo in high fat-fed apolipoprotein E deficient (ApoE(-/-)), ApoE(-/-)/Mrp14(-/-) (double knockout) and chow-fed wild-type (C57BL/6) mice. Bone marrow-derived myeloid progenitor cells were isolated from both ApoE(-/-) and double knockout mice, differentiated to macrophages, and were treated with LPS, with or without Mrp8, Mrp14, or Mrp8/14; conditioned media was used for in vitro studies. Mrp-activated cells secreted significant amounts of proinflammatory cytokines, which was abolished by pretreatment with aMrp-NP. We show in vitro that aMrp-NP binds endothelial cells previously treated with conditioned media containing Mrp8/14. MRI following intravenous delivery of aMrp-NP revealed prolonged and substantial delineation of plaque in ApoE(-/-) but not double knockout or wild-type animals. Nonspecific IgG-conjugated gadolinium nanoprobe-injected animals in all groups did not show vessel wall enhancement. Flow-cytometric analysis of aortic digesta revealed that aMrp-NP present in Ly-6G(+), CD11b(+), CD11c(+), and CD31(+) cells in ApoE(-/-) but not in double knockout animals.
Targeted imaging with aMrp-NP demonstrates enhancement of plaque with binding to inflammatory cells and reduction in inflammation. This strategy has promise as a theranostic approach for atherosclerosis.
髓系相关蛋白 (Mrp) 8/14 复合物（是一种高度表达的细胞外分泌蛋白，与动脉粥样硬化有关。在这项研究中，我们评估了通过合成免疫纳米探针在体内靶向 Mrp 的可行性。
合成并表征了抗 Mrp-14 和非特异性 IgG 偶联钆纳米探针（aMrp-）。在高脂喂养的载脂蛋白 E 缺陷型（ApoE（-/-））、ApoE（-/-）/Mrp14（-/-）（双敲除）和普通饮食喂养的野生型（C57BL/6）小鼠体内评估了制剂的药代动力学和通过 MRI 的血管靶向作用。从 ApoE（-/-）和双敲除小鼠中分离出骨髓源性髓样祖细胞，分化为巨噬细胞，并用 LPS 处理，有或没有 Mrp8、Mrp14 或 Mrp8/14；用条件培养基进行体外研究。Mrp 激活的细胞分泌大量促炎细胞因子，用 aMrp-NP 预处理可消除这些细胞因子。我们在体外证明，aMrp-NP 与先前用含有 Mrp8/14 的条件培养基处理过的内皮细胞结合。静脉注射 aMrp-NP 后的 MRI 显示，在 ApoE（-/-）但不在双敲除或野生型动物中，斑块的显影时间延长且显著。在所有组中，非特异性 IgG 偶联的钆纳米探针注射动物均未显示血管壁增强。对主动脉消化物的流式细胞分析显示，aMrp-NP 存在于 ApoE（-/-）但不存在于双敲除动物的 Ly-6G(+)、CD11b(+)、CD11c(+) 和 CD31(+) 细胞中。
用 aMrp-NP 进行靶向成像显示，与炎症细胞结合并减少炎症可增强斑块显影。这种策略有望成为动脉粥样硬化的治疗策略。
