Endothelial reactivity and nitric oxide synthetase activity in the ALMS (Aspreva

描述(由申请人提供)：系统性红斑狼疮(SLE)的器官特异性表现受到血管系统固有特征的高度影响。尽管内皮细胞通常起到阻止细胞外渗的作用，但在炎症部位，这种活着的屏障会经历显著的表型变化。这一建议的总体假设是，SLE患者的内皮表型显著改变，继发于诱导型一氧化氮合酶(NOS2)的表达增加。第二个假设是，NOS2依赖的内皮细胞表型与促凝血剂素质有关，最终导致血栓性微血管病变和终末器官损伤。为这项研究提供分子基础的关键环节是免疫调节药物霉酚酸酯(MMF)与环磷酰胺或硫唑嘌呤相比，干扰了蝶呤对NOS2的可用性。Aspreva狼疮管理研究(ALMS)是一项多中心试验，旨在评估MMF与静脉注射环磷酰胺(IVC)在诱导狼疮性肾炎反应方面的疗效，以及MMF与硫唑嘌呤在维持反应方面的疗效。这项应用的主要目的是检查MMF受益的细胞机制是否至少部分归因于对改变的内皮的修复作用。提出了三个具体目标。在目标1中，方法是纵向计数血和尿NO水平，以及反映内皮损伤和再生的循环细胞成分水平，并将这些细胞和代谢物指标与皮肤活检组织中黏附分子和NOS2/3的表达进行比较。在目标2中，将对血浆和尿液中依赖NOS2的内皮激活、炎症和凝血酶激活的标志物进行定量和纵向评估。根据描述NOS2参与内皮细胞损伤和随后的肾脏损伤的致病模型，选择了sEPCR、IL-18和(F1 2)凝血酶原三个候选基因。第四个候选者，脂联素，被选为反映炎症的生物标志物，但可能不依赖于NO的产生。这些标记物将与皮肤和肾脏活检的免疫染色相关。目的3将与炎症、血管收缩反应和凝血相关的基因多态性与MMF和IVC(诱导期)后的临床结果以及反映滤过异常的标志物联系起来。将检测NOS2、NOS3、EPCR、IL-18和ACE启动子区域/外显子上的SNPs。正在测试的假设是，拥有SNP可能与EGFR或蛋白质/肌酐比率异常有关，这可能在一定程度上解释了治疗的有效性。与公众健康的相关性：狼疮性肾炎成功的药物治疗的作用机制与NOS2表达的标记物/指数的关联将是一个重大进展。

DESCRIPTION (provided by applicant): The organ-specific manifestations of systemic lupus erythematosus (SLE) are highly influenced by the inherent characteristics of the vasculature. Although the endothelium normally functions to thwart cell extravasation, at sites of inflammation this living barrier undergoes remarkable phenotypic changes. The overall hypothesis of this proposal is that the endothelial phenotype in SLE patients is substantially altered secondary to increased expression of inducible nitric oxide synthetase (NOS2). A secondary hypothesis is that the NOS2-dependent endothelial phenotype is associated with a procoagulant diathesis which ultimately leads to thrombotic microangiopathy and end-organ injury. The essential link providing the molecular rationale for the proposed study is that the immunomodulatory drug mycophenolate mofetil (MMF), in contrast to cyclophosphamide or azathioprine, interferes with pterin availability to NOS2. The Aspreva Lupus Management Study (ALMS) is a multi-center trial to assess the efficacy of MMF compared to intravenous cyclophosphamide (IVC) in the induction, and MMF vs. azathioprine in the maintenance, of response in lupus nephritis. The major goal of this application is to examine whether the cellular mechanism accounting for the benefit of MMF is due, at least in part, to a restorative effect on the altered endothelium. Three specific aims are proposed. In Aim 1, the approach is to enumerate longitudinally serum and urinary levels of NO, and circulating levels of cellular components reflecting endothelial injury and regeneration, and to compare these cellular and metabolite measures with expression of adhesion molecules and NOS2/3 in skin biopsies. In Aim 2, markers of NOS2-dependent endothelial activation, inflammation, and thrombin activation will be evaluated quantitatively and longitudinally in plasma and urine. Three candidates, sEPCR, IL-18, and (F1+2) prothrombin were selected based on a pathogenic model which describes the involvement of NOS2 in endothelial cell injury and consequent renal damage. A fourth candidate, adiponectin, was chosen as a biomarker that reflects inflammation but may be independent of NO production. These markers will be correlated to immunostains of the skin and renal biopsies. Aim 3 will relate genetic polymorphisms associated with inflammation, vasoconstrictor responses and coagulation with clinical outcomes following MMF and IVC (Induction Phase) as well as with markers reflecting filtration abnormalities. SNPs in the promoter region/exons for NOS2, NOS3, EPCR, IL-18 and ACE will be examined. The hypothesis being tested is that possession of a SNP may be associated with abnormal eGFR or protein/creatinine ratios, which may in part explain the effectiveness of therapy. Relevance to public health: The association of markers/indices of NOS2 expression with mechanism of action of a successful drug treatment in lupus nephritis would be a major advance.