Role of Estrogen Receptors in Lupus-Modulators of the Inflammatory Response

描述(由申请人提供)： 摘要系统性红斑狼疮(SLE)是一种以自身抗体产生和免疫复合体介导的器官损害为特征的自身免疫性疾病。系统性红斑狼疮的一个更深刻的特征是，女性的疾病患病率是男性的9：1。导致SLE患者性别差异的原因是多方面的，包括性激素本身及其受体。雌激素主要通过其受体--雌激素受体α和β(ER1/ER2)起作用。然而，雌激素也可以通过非受体介导的机制起作用，同样，ER介导的生理功能不依赖于雌激素。在之前的资助期间，我们获得了ER1和ER2基因敲除的狼疮倾向MRL/LPR和NZM2410小鼠。在这两个品系中，女性ER1 KO发生蛋白尿和病理性肾脏疾病的情况显著减少，尽管血清自身抗体水平上升，但存活时间显著延长。这些发现使我们假设，狼疮性肾炎中ER1缺乏的主要影响是肾脏对炎症的反应。我们从B6小鼠中分离出ER1KO和ER2KO系膜细胞，发现ER1KO系膜细胞对TLR2、3和7配体有明显的钝化反应。ER2的表达对肾小球系膜细胞反应无影响。基于这些发现，我们假设ER1的缺乏是通过钝化系膜细胞对TLR3/7诱导的炎症的反应来保护雌性狼疮小鼠的肾脏。我们认为这种ER1保护作用是雌激素非依赖性的，并通过TLR3/7诱导ER1的磷酸化来介导。为了验证这一假说，我们提出了以下具体目标：1.利用Sle1、Sle3和Sle1/3同基因小鼠以及ER1 KO和ER1 WT小鼠的骨髓移植，在体内确定ER1缺乏对狼疮发病机制的影响。2.明确TLR/ER1相互作用影响系膜细胞炎症反应的体外分子机制，评估ER1对TLR3/7激活通路和TLR3/7对ER1表达的影响。3.利用影响特定ER1功能的突变型ER1敲击菌株，在体内和体外确定ER1影响TLR信号的机制，从而确定特定ER1在免疫反应中的功能。这些研究将为ER1缺乏影响狼疮疾病表达的机制提供新的见解，并进一步描绘ER1和TLR诱导的炎症之间的相互作用，这可能是女性在狼疮中占优势的部分原因。 公共卫生相关性： 相关声明狼疮是一种在退伍军人中日益流行的疾病。这主要是一种妇女和少数民族的疾病，他们在退伍军人管理局诊所的患者中所占比例越来越大。越来越令人担忧的是，尽管最近在医疗保健方面取得了进展，但在少数族裔中，狼疮的死亡率和进展为肾衰竭的情况继续增加。这项建议解决了狼疮中一个关键的悬而未决的问题，即9/1女性在疾病中占优势的机制。我们发现，雌激素受体α(ER1)是雌性狼疮易感小鼠系统性红斑狼疮的关键介质，并且ER1至少部分地通过调节与狼疮有关的特定TLR配体的炎症反应来介导这一效应。进一步明确ER1在系统性红斑狼疮中的作用将为疾病机制和新的治疗方法提供新的见解。

DESCRIPTION (provided by applicant): Abstract Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by autoantibody production and immune complex mediated organ damage. One of the more profound features of SLE is females having a 9:1 prevalence of disease over men. The cause of this gender difference in SLE is multifactorial, including the sex hormones themselves and their receptors. Estrogen acts primarily via its receptors, estrogen receptor alpha and beta (ER1/ER2). Estrogen can also act, however, through non-receptor mediated mechanisms and, in kind, the ERs mediate physiologic functions independent of estrogen. In the previous funding period, we derived ER1 and ER2 knockout lupus prone MRL/lpr and NZM2410 mice. In both strains, the female ER1 KOs developed significantly less proteinuria and pathologic renal disease and had significantly prolonged survival, despite increased serum levels of autoantibodies. These findings led us to postulate that the primary impact of ER1 deficiency in lupus nephritis was on the response of the kidney to inflammation. We derived ER1 KO and ER2 KO mesangial cells from B6 mice and found that ER1 KO mesangial cells had a marked blunted response to TLR 2, 3 and 7 ligands. ER2 expression had no effect on mesangial cell responses as tested. Based on these findings, we hypothesize that the lack of ER1 is renal protective in female lupus mice by blunting the response of mesangial cells to TLR3/7 induced inflammation. We believe this ER1 protective effect is estrogen independent and mediated via TLR3/7 induced phosphorylation of ER1. To test this hypothesis, we propose the following Specific Aims: 1. Determine in vivo the effects of ER1 deficiency on known mechanisms of lupus pathogenesis using sle1, sle3 and sle1/3 congenic mice and bone marrow transplantation of ER1 KO and ER1 WT mice. 2. Define the in vitro molecular mechanisms underlying TLR/ER1 interactions that impact the inflammatory response in mesangial cells assessing the impact of ER1 on the TLR3/7 activation pathways and TLR3/7 on ER1 expression. 3. Define in vivo and in vitro the mechanisms by which ER1 impacts TLR signaling utilizing mutant ER1 knockin strains that affect specific ER1 functions allowing delineation of specific ER1 functions on the immune response. These studies will provide novel insight into the mechanisms by which ER1 deficiency impacts lupus disease expression and further delineate the interaction between ER1 and TLR induced inflammation that may partially underlie the female predominance in lupus. PUBLIC HEALTH RELEVANCE: Relevance Statement Lupus is a disease with increasing prevalence in the Veteran population. It is primarily a disease of women and minorities, who represent an increasing proportion of patients in VA clinics. Of increasing concern is, that despite recent advances in medical care, mortality rates and progression to renal failure continue to increase in lupus in minorities. This proposal addresses one of the key unanswered questions in lupus, that of the mechanism underlying the 9/1 female predominance in disease. We found that estrogen receptor alpha (ER1) is a key mediator of SLE in female lupus prone mice and that ER1 mediates this effect, at least partially, by modulating the inflammatory response to specific TLR ligands implicated in lupus. Further defining the effect of ER1 on SLE will provide new insight into mechanisms of disease and novel approaches to therapy.