The Role of Estrogen Receptor Alpha Variant Size and Localization in Modulating TLR7-Induced Inflammation

系统性红斑狼疮（SLE）是一种自身免疫性疾病， 女性虽然狼疮的许多风险因素被确定：> 170个基因，包括GPR174，无数 环境暴露和异常的X染色体失活，这些都不能充分解释陡峭的 青春期AD的发病率以女性特有的方式上升。流行病学研究表明 自身免疫性疾病中的性激素及其受体。我们之前的研究表明， 仅表达短型雌激素受体α（ER α short）的小鼠， 疾病和提高生存率。确定这种保护作用的机制，即雌激素 这是本提案的主要目标。值得注意的是，ER α-/-（null）狼疮易感小鼠与正常小鼠相比， 保护.综合起来，我们的数据表明，ER α的短型的存在提供了保护，而不是ER α的短型。 不存在全长ER α。其他人和我们证明了ER α在树突状细胞（DC）发育中的关键作用 和内体Toll样受体（TLR）反应性。有趣的是，在ER α短小鼠中表达的ER α是 与缺乏相同AF-1结构域的内源性ER α变体（ER α 46）结构相似， 与全长ER α相比调节基因转录。ER α 46在体外过表达也可调节TLR- 与此建议相关的诱导反应。在本研究中，我们将进一步探讨ER α在细胞凋亡中的作用。 在调节TLR7诱导的免疫应答中的短变体，并确定是否是基因组和/或非基因组变体。 ER α短变体作用的基因组机制是保护性的。我们的总体假设是， 免疫细胞表达ER α短或ER α 46具有抗炎作用， 与健康对照组相比，狼疮患者的ER α 66水平降低。我们还假设， 具有改变ER α的新型抗炎选择性雌激素受体调节剂（SERM）的免疫细胞 膜信号传导和/或ER α诱导的转录将解偶联雌激素介导的抗炎 影响生殖组织的反应。我们将通过完成以下任务来验证我们的假设： 具体目的：1）过表达ER α短或用新的SERM（OBHS，PaPE）处理免疫细胞， ER α的抗炎特性，并确定对已知TLR7诱导的炎症终点的影响， 2)研究仅膜ER α信号传导与仅核ER α表达对TLR7诱导的细胞凋亡的影响。 3）鉴定人单核细胞来源的树突状细胞（mo-DCs）和B细胞中的ER α变体 使用液滴数字PCR和Iso-Seq技术，以确定ER α 46是否在 狼疮患者与对照组，可能解释了女性自身免疫易感性的生物学差异。 这些目标将使我们能够确定我们是否可以将ER α的生殖作用与其潜在的可修饰性分开。 免疫效应作为一种治疗策略，如果成功，将提供新的免疫方法 调节狼疮和其他免疫介导的疾病，特别是那些有显着的性别偏见。

Systemic lupus erythematosus (SLE) is one of many autoimmune diseases that disproportionately affects females. Although many risk factors for lupus are identified: >170 genes including GPR174, myriad environmental exposures, and aberrant X chromosome inactivation, none of these sufficiently explain the steep rise in incidence of ADs at the time of puberty in a female-specific manner. Epidemiology suggests a major role for sex hormones and their receptors in autoimmune diseases. We previously showed that female lupus-prone mice, expressing only a short form of estrogen receptor alpha (ERα short), have significantly reduced renal disease and increased survival. Determining the mechanism of this protective effect, which is estrogen dependent, is the primary goal of this proposal. Of note, ERα-/- (null) lupus prone mice were not similarly protected. Combined, our data suggest that the presence of the short form of ERα confers protection, not the absence of full-length ERα. Others and we demonstrated a critical role for ERα in dendritic cell (DC) development and endosomal Toll-like receptor (TLR) responsiveness. Interestingly, the ERα expressed in ERα short mice is similar in structure to an endogenous ERα variant (ERα46) that lacks the same AF-1 domain, and differentially regulates gene transcription compared to full length ERα. Overexpressing ERα46 in vitro also modulates TLR- induced responses, relevant to this proposal. In the proposed study, we will further investigate the role of ERα short variants in modulating TLR7-induced immune responses, and determine whether genomic and/or non- genomic mechanisms of ERα short variant action are protective. Our overall hypothesis is that increasing expression of ERα short or ERα46 in immune cells will be anti-inflammatory, and that the ratio of ERα46 to ERα66 is decreased in lupus patients versus healthy controls. We also hypothesize that targeting immune cells with novel anti-inflammatory selective estrogen receptor modulators (SERMs) that alter ERα membrane signaling and/or ERα-induced transcription will uncouple estrogen-mediated anti-inflammatory responses from those impacting reproductive tissues. We will test our hypotheses by accomplishing these Specific Aims: 1) Overexpress ERα short or treat immune cells with novel SERMs (OBHS, PaPE) that select for anti-inflammatory properties of ERα and determine the effect on known TLR7-induced inflammatory endpoints, 2) Investigate effects of membrane-only ERα signaling vs. nuclear only ERα expression on TLR7-induced pathways in mice, and 3) Identify ERα variants in human monocyte-derived dendritic cells (mo-DCs) and B cells using droplet digital PCR and Iso-Seq technology, to determine whether ERα46 is differentially expressed in lupus patients vs. controls, potentially explaining a biologic difference in females predisposed to autoimmunity. These aims will allow us to determine if we can separate ERα's reproductive effects from its potentially modifiable immune effects as a therapeutic strategy, which if successful, will provide novel approaches to immune modulation in lupus and other immune mediated diseases, especially those with a significant sex bias.