MODIFIED LDL, AUTOIMMUNITY AND VASCULAR DISEASE IN DIABETES

描述：（申请人提供） 高水平的免疫复合物（IC）含有oxLDL预测的发展 1型糖尿病（DM）大血管并发症的发生率， 2型糖尿病的冠状动脉疾病（CAD）。在进行中获得的数据 资助期间显示，oxLDL-IC水平与 颈内动脉内膜中层厚度（p<0.001，n=853）， 1型糖尿病伴微量/大量白蛋白尿显著增加， 中度/重度视网膜病变，与 正常白蛋白尿或轻度视网膜病变（分别为P<0.013和0.0006）。的 LDL-IC水平与血清Apo B水平、血清Lp（a） 水平和血清甘油三酯（p<0.0001，n=853），也有显着性差异 与C-反应蛋白和可溶性白蛋白的直接相关性（p<0.0001，n=854） ICAM-1（p<0.02，n=455）。LDL-IC也与Hb A1 c相关（p<0.005， n=888），表明血糖控制将影响LDL-IC的形成。 我们还证实了微量或大量白蛋白尿患者， 从oxLDL-IC中分离的抗ox-LDL的抗体（Ab）具有较高的亲和力 比相同患者血清中存在的游离抗体高。这表明， 决定oxLDL-IC致病性的关键因素是 中等亲和力的oxLDL Ab，能够与促炎因子形成稳定的IC 潜力因为衣原体肺炎已经被证明有很强的 与CAD的流行病学相关性及其主要抗原之一是细胞 壁脂多糖（LPS），当释放到循环中时， 通过脂蛋白运输，我们计划研究衣原体LPS是否是 存在于从糖尿病患者血清中纯化的IC中。 本提案的主要目的是比较可溶性粘附的水平 分子（sCAM）和LDL-IC的水平和特征， 2型糖尿病队列（前瞻性VA合作试验）的血清， 强化或标准血糖控制。我们假设，类似于 1型DM、2型DM的LDL-IC具有促炎特征， 与微血管和大血管并发症有关。我们进一步假设 强化血糖控制会影响IC的形成， 将CAM释放到流通中。我们还建议确定是否或 不是DCCT/EDIC队列（1型DM）和VA队列2（2型DM）的患者 发展为大血管疾病、视网膜病和微量/大量蛋白尿 慢性丙型肝炎的发病率更高。肺炎感染和表征 来自队列1和2的患者血清中存在的IC， oxLDL、oxLDL-Lp（a）、AGE-LDL的大血管疾病/肾病/视网膜病， Chlamdial-LPS或DNA，以及针对这些抗原的Ab。我们还将 确定从IC分离的Ab的亲和力和同种型分布， 评估其促炎潜力。最后，我们将评估 通过研究这些IC触发的致病机制， 诱导胆固醇在巨噬细胞、肾系膜细胞和 视网膜周细胞，并激活这些细胞，导致表达 细胞因子、sCAM和金属蛋白酶。 将我们的研究纳入该计划使我们能够比较LDL-IC水平 炎症标记物和内皮细胞功能障碍标记物 在其他项目中进行测量，这将有助于更好地了解 对修饰形式的LDL的自身免疫应答对 糖尿病动脉粥样硬化的发病机制。

DESCRIPTION: (provided by applicant) High levels of immune complexes (IC) containing oxLDL predict the development of macrovascular complications in type 1 diabetes (DM) and are associated with coronary artery disease (CAD) in type 2 DM. Data obtained during the on-going funding period shows that the levels of oxLDL-IC are significantly associated with internal carotid intima-medial thickness (p<0.001, n=853) and are significantly increased in type 1 DM with micro/macroalbuminuria and moderate/severe retinopathy, compared with levels of LDL-IC in patients with normalalbuminuria or mild retinopathy (p<0.013 and 0.0006, respectively). The levels of LDL-IC are strongly correlated with serum Apo B levels, serum Lp(a) levels and serum triglycerides (p<0.0001, n=853) and have also a significant direct correlation (p<0.0001, n=854) with C-reactive protein and with soluble ICAM-1 (p<0.02, n=455). LDL-IC correlate as well with Hb A1c (p<0.005, n=888), suggesting that glycemic control will impact the formation of LDL-IC. We have also demonstrated in patients with micro or macroalbuminuria that antibodies (Ab) against ox-LDL isolated from oxLDL-IC have a higher affinity than the free Ab present in sera of the same patients. This suggests that one critical factor determining the pathogenicity of oxLDL-IC is the synthesis of oxLDL Ab of moderate affinity, able to form stable IC with pro-inflammatory potential. Because Chlamydia pneumonia has been shown to have a strong epidemiological correlation with CAD and one of its major antigens is a cell wall lipopolysaccharide (LPS), that when released into circulation is transported by lipoproteins, we plan to investigate whether chlamydia LPS is present in IC purified from sera of diabetic patients. The main goal of this proposal is to compare the levels of soluble adhesion molecules (sCAM) and the levels and characteristics of LDL-IC isolated from the sera of a type 2 DM cohort (Prospective VA Cooperative Trial) under intensive or standard glycemic control. We hypothesize that, similarly to type 1 DM, LDL-IC in type 2 DM have pro-inflammatory characteristics and are associated with micro and macrovascular complications. We further hypothesize that intensive glycemic control will impact the formation of IC and the release of CAMs into the circulation. We also propose to determine whether or not patients from the DCCT/EDIC cohort (type 1 DM) and VA cohort 2 (type 2 DM) that develop macrovascular disease, retinopathy and micro/macro-albuminuria have a higher incidence of chronic C. pneumoniae infection and to characterize the IC present in the serum of patients from both cohort 1 and 2 that develop macrovascular disease/nephropathy/retinopathy for oxLDL, oxLDL-Lp(a), AGE-LDL, Chlamdial-LPS or DNA, as well as Ab against these antigens. We will also determine the affinity and isotype distribution of Ab isolated from IC, to evaluate their pro-inflammatory potential. Finally, we will assess possible pathogenic mechanisms triggered by these IC by investigating their ability to induce accumulation of cholesterol in macrophages, kidney mesangial cells and retinal pericytes and to activate these cells leading to the expression of cytokines, sCAM and metalloproteinases. Incorporation of our study into the Program allows us to compare LDL-IC levels with the inflammatory markers and endothelial cell dysfunction markers measured in other projects and that will result in a better understanding of the significance of auto-immune responses to modified forms of LDL to the pathogenesis of atherosclerosis in diabetes.