ESE 1 a novel transcriptional regulator of cartilage remodeling

描述(申请人提供)：最初被描述为上皮特异性Ets(ESE)-1(在小鼠中为Elf3)，我们发现这种新的转录因子通过与COL2A1启动子结合并与Sox9和CBP相互作用来抑制II型胶原基因(COL2A1)的表达，并且骨关节炎(OA)患者的软骨表层和中层ESE-1免疫染色增加。我们的初步数据表明，ESE-1通过与MMP13启动子上的Ets/PEA3位点结合，并与Runx2和AP-1协同作用，促进基质金属蛋白酶(MMP13)-13的转录。Ese1/Elf3基因缺陷小鼠关节软骨中不存在基质金属蛋白酶-13蛋白，而与野生型小鼠相比，CHO/+模型小鼠关节软骨中Ese1表达增加，进一步表明其在骨关节炎关节软骨重塑中的关键作用。因此，我们假设ESE-1是骨性关节炎进展过程中软骨重塑的关键转录调节因子。其具体目的是：(1)诱导和激活ESE-1调节基质金属蛋白酶-13和其他靶点的信号通路是什么？我们将使用原代小鼠和人类软骨细胞和细胞系来表征ESE-1在MMP13和其他基因靶点的诱导和作用中所涉及的信号和转录机制，包括决定ESE-1在基础和炎症条件下的作用的结构/功能关系。(2)Ese1/Elf3缺失是否能保护或减轻外科和遗传性骨关节炎小鼠模型中的软骨丢失？如果是，其作用机制是什么？我们将使用Ese1/Elf3基因敲除小鼠进行非遗传实验诱导的(手术)骨关节炎和CHO/+小鼠的年龄依赖的骨关节炎模型，并通过敏感的、原位的基因表达分析和目标1中开发的其他技术，在骨关节炎的发生和发展过程中进行MAP基因表达。(3)ESE-1的过度表达是否影响由于衰老或手术骨关节炎而导致的小鼠膝关节骨关节炎的发生或发展？我们将建立Tet-Off诱导的Ese1转基因小鼠，以检查过量的ESE-1本身是否启动或加速了手术诱导的OA，并揭示ESE-1依赖的机制是否与OA的进展程度相关。通过将体外研究的见解应用于通过体外和原位方法在小鼠模型中分析早期和晚期事件，我们将了解潜在的启动和进展的分子事件，这些事件将导致因创伤或衰老而导致的新的靶向治疗OA的开发。

DESCRIPTION (provided by applicant): Described originally as Epithelial Specific ETS (ESE)-1 (Elf3 in mouse), we have found that this novel transcription factor suppresses type II collagen gene (COL2A1) expression by binding to the COL2A1 promoter and interacting with Sox9 and CBP and that ESE-1 immunostaining is increased in superficial and midzone regions of cartilage from patients with osteoarthritis (OA). Our preliminary data show that ESE-1 increases the transcription of matrix metalloproteinase (MMP)-13 by binding to ETS/PEA3 sites in the MMP13 promoter and cooperating with Runx2 and AP-1. The absence of MMP-13 protein in the Ese1/Elf3-deficient mouse and the increased Ese1 expression in the articular cartilage of the cho/+ mouse model of OA compared to wild type mice further suggest its pivotal role in de-regulated cartilage remodeling during OA. Thus, we hypothesize that ESE-1 is a critical transcriptional regulator of cartilage remodeling during OA progression. The Specific Aims are: (1) What are the signaling pathways that induce and activate ESE-1 to regulate MMP-13 and other targets? We will use primary mouse and human chondrocytes and cell lines to characterize the signaling and transcriptional mechanisms involved in the induction and action of ESE-1 in the regulation of MMP13 and other gene targets, including the structure/function relationships that determine ESE-1 actions under basal and inflammatory conditions. (2) Does Ese1/Elf3-deficiency protect against or attenuate cartilage loss in surgical and genetic mouse models of OA, and if so, what are its mechanisms of action? We will employ Ese1/Elf3 knockout mice subjected to non-genetic experimentally induced (surgical) OA and the Cho/+ mouse model of age-dependent OA and map gene expression during onset and progression of OA by sensitive, in situ gene expression analysis and other techniques developed in Aim 1. (3) Does ESE-1 over-expression affect the onset or progression of OA in mouse knee joints due to aging or surgical OA? We will generate Tet-Off-inducible Ese1 transgenic mice to examine whether excess ESE-1, by itself, initiates or accelerates surgically induced OA and reveal if ESE-1-dependent mechanisms correlate with the extent of OA progression. By applying insights from in vitro studies to the analysis of early and late events by ex vivo and in situ approaches in the mouse models, we will gain understanding of molecular events underlying initiation and progression that will lead to the development of novel targeted therapies for OA due to trauma or aging.