目的:餐后高甘油三酯血症(PHTG)是冠心病的独立危险因素。PHTG表现出含有apoB-48的乳糜微粒残留物(CM-Rs)和含有apoB-100的VLDL残留物(VLDL-Rs)的积累,都被认为是致动脉粥样硬化的.然而,与VLDL-Rs不同,由于从VLDL-R中分离CM-Rs的挑战,CM-Rs的结构和功能表征仍有待阐明。最近,我们利用抗apoB-48或apoB-100特异性抗体成功分离了CM-Rs和VLDL-Rs。本研究旨在表征CM-Rs和VLDL-Rs的蛋白质组。
方法:纳入8名健康受试者。在高脂肪膳食后3小时抽取静脉血。我们使用apoB-48或apoB-100特异性抗体通过超速离心和免疫沉淀从血清中分离出CM-Rs和VLDL-Rs,其次是鸟枪蛋白质组学分析。
结果:我们鉴定了42个CM-Rs或VLDL-Rs相关蛋白,包括11种潜在的新鉴定的蛋白质,例如血小板碱性蛋白(PPBP)和血小板因子4,它们是血小板分泌的趋化因子。ApoA-I,apoA-IV,和clusterin,也被称为HDL相关蛋白,在CM-RS中明显更丰富。有趣的是,apoC-I,这降低了脂蛋白脂肪酶的活性并最终抑制了残余蛋白的分解代谢,在CM-RS中也更丰富。此外,我们鉴定了参与补体调节的蛋白质,如补体C3和玻连蛋白,那些参与急性期反应的人,如PPBP,CM-Rs和VLDL-Rs中的血清淀粉样蛋白A蛋白2和蛋白S100-A8。
结论:我们首先表征了CM-R的蛋白质组。这些发现可能为CM-R的动脉粥样硬化特性提供了解释。
OBJECTIVE: Postprandial hypertriglyceridemia (PHTG) is an independent risk factor for coronary heart diseases. PHTG exhibits accumulation of apoB-48 containing chylomicron remnants (CM-Rs) and apoB-100 containing VLDL remnants (VLDL-Rs), which are both known to be atherogenic. However, unlike VLDL-Rs, structural and functional characterization of CM-Rs remains to be elucidated due to challenges in separating CM-Rs from VLDL-Rs. Recently, we successfully isolated CM-Rs and VLDL-Rs utilizing anti-apoB-48 or apoB-100 specific antibodies. This study aimed to characterize the proteome of CM-Rs along with that of VLDL-Rs.
METHODS: Eight healthy subjects were enrolled. Venous blood was drawn 3 hours after high-fat-containing meals. We isolated CM-Rs and VLDL-Rs from sera through combination of ultracentrifugation and immunoprecipitation using apoB-48 or apoB-100 specific antibodies, followed by shotgun proteomic analysis.
RESULTS: We identified 42 CM-Rs or VLDL-Rs-associated proteins, including 11 potential newly identified proteins such as platelet basic protein (PPBP) and platelet factor 4, which are chemokines secreted from platelets. ApoA-I, apoA-IV, and clusterin, which are also known as HDL-associated proteins, were significantly more abundant in CM-Rs. Interestingly, apoC-I, which reduces the activity of lipoprotein lipase and eventually inhibits catabolism of remnant proteins, was also more abundant in CM-Rs. Moreover, we identified proteins involved in complement regulation such as complement C3 and vitronectin, and those involved in acute-phase response such as PPBP, serum amyloid A protein 2, and protein S100-A8, in both CM-Rs and VLDL-Rs.
CONCLUSIONS: We have firstly characterized the proteome of CM-Rs. These findings may provide an explanation for the atherogenic properties of CM-Rs.