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）的器官特异性表现高度受血管系统固有特征的影响。虽然内皮细胞正常的功能是阻止细胞外渗，但在炎症部位，这种活屏障会发生显著的表型变化。该建议的总体假设是，SLE患者的内皮细胞表型实质性改变继发于诱导型一氧化氮合成酶（NOS 2）表达的增加。第二个假设是，NOS 2依赖的内皮细胞表型与促凝血素质，最终导致血栓性微血管病和终末器官损伤。为拟议研究提供分子理论基础的重要环节是，与环磷酰胺或硫唑嘌呤相反，免疫调节药物吗替麦考酚酯（MMF）干扰了NOS 2对蝶呤的利用度。Aspreva狼疮管理研究（ALMS）是一项多中心试验，旨在评估与静脉内环磷酰胺（IVC）相比，MMF在诱导狼疮肾炎缓解方面的疗效，以及与硫唑嘌呤相比，MMF在维持狼疮肾炎缓解方面的疗效。本申请的主要目的是检查说明MMF益处的细胞机制是否至少部分归因于对改变的内皮的恢复作用。提出了三个具体目标。在目的1中，该方法是纵向列举血清和尿液中的NO水平，以及反映内皮损伤和再生的细胞成分的循环水平，并将这些细胞和代谢产物的测量与皮肤活检中粘附分子和NOS 2/3的表达进行比较。在目标2中，将在血浆和尿液中定量和纵向评价NOS 2依赖性内皮活化、炎症和凝血酶活化的标志物。基于描述了NOS 2参与内皮细胞损伤和随后的肾损伤的致病模型，选择了三种候选物，sEPCR、IL-18和（F1+2）凝血酶原。第四个候选者，脂联素，被选为反映炎症的生物标志物，但可能是独立的NO生产。这些标志物将与皮肤和肾活检的免疫染色相关联。目的3将与炎症、血管收缩反应和凝血相关的遗传多态性与MMF和IVC（诱导期）后的临床结局以及反映滤过异常的标志物相关。将检查NOS 2、NOS 3、EPCR、IL-18和ACE的启动子区/外显子中的SNP。正在测试的假设是，拥有SNP可能与异常eGFR或蛋白质/肌酐比值相关，这可能部分解释了治疗的有效性。与公共卫生的相关性：NOS 2表达的标志物/指数与狼疮肾炎中成功药物治疗的作用机制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.