TNF-alpha to TGF-beta Signal Transduction

描述(由申请人提供)：间质性肺纤维化(IPF)有多种病因，并困扰着全球数百万人。然而，目前还没有有效的预防性药物或治疗方法。这种情况在很大程度上是由于缺乏对介导纤维化过程的基本分子机制的了解。在这里提出的工作中，我们将重点放在两个肽因子上，这两个因子被许多研究人员认为是IPF发展的核心。这些因子是肿瘤坏死因子-α(TNF-α)和转化生长因子-β1(TGF-β1)。我们以前的工作和初步数据表明，在体外和体内，肿瘤坏死因子-α上调转化生长因子-β1的表达，但肿瘤坏死因子-α影响转化生长因子-β1表达的基本机制尚不清楚。肿瘤坏死因子-α被许多人认为是一种“主要细胞因子”，它控制着许多生物相关分子的表达。鉴于转化生长因子-β1被认为是一种主要的“纤维化因子”，我们提出了一个中心假设，即肿瘤坏死因子-α通过MEK/ERK途径在转录调控中诱导转化生长因子-β1的产生：而由肿瘤坏死因子-α通过转化生长因子-β1介导的纤维化形成途径可以被特定的siRNA阻断，该siRNA介导编码肿瘤坏死因子-α、MEK/ERK磷酸化的关键成分MP-1和转化生长因子-β1的转录本的降解。特异靶1将建立从肿瘤坏死因子-α到转化生长因子-β1的MEK/ERK信号转导通路和转录表达机制。目标2将集中于通过这一相同途径上调转化生长因子-β1的其他因素；在目标3中，我们将了解在健康和疾病中，活体肺上皮细胞和间充质细胞是否表现出相同的转导和转录途径。这些研究将通过使用小干扰RNA(SiRNA)为潜在的治疗方法提供特定的靶点。因此，在目标4中，我们将展示我们设计的siRNA可以阻断内源性肿瘤坏死因子-α基因的表达。我们建议使用这个结构和降解MP1(MEK/ERK磷酸化的关键蛋白)的siRNA，最后使用siRNA来阻止转化生长因子-β1的表达，并最终在我们建立的动物模型中发展成IPF。

DESCRIPTION (provided by applicant): Interstitial pulmonary fibrosis (IPF) has numerous etiologies and afflicts millions of individuals worldwide. Yet, there are no effective preventive agents or therapeutic approaches. This situation is due in large part to a lack of understanding of the fundamental molecular mechanisms that mediate the fibrogenic process. In the work proposed here, we have focused on two peptide factors that have been implicated by numerous researchers as central to the development of IPF. These factors are tumor necrosis factor alpha (TNF-a) and transforming growth factor beta one (TGF-B1). Our previous work and preliminary data show that TNF-a up-regulates the expression of TGF-B1 both in vitro and in vivo, but the basic mechanisms through which TNF-a influences TGF-B1 expression remain undefined. TNF-a has been considered by many to be a "master cytokine" that controls the expression of a number of biologically relevant molecules. In as much as TGF-B1 is considered to be a primary "fibrogenic factor", we have set forth the central hypothesis that TNF-a induces TGF-B1 production by transcriptional regulation through the MEK/ERK pathway in lung cells: and the pathway of fibrogenesis mediated by TNF-a through TGF-B1 can be interrupted by specific siRNAs that mediate the degradation of transcripts that code for TNF-a, MP-1- a key component of MEK/ERK phosphorylation, and TGF-B1. Specific Aim 1 will establish MEK/ERK transduction pathways from TNF-a to TGF-B1 and the transcriptional mechanisms of expression. Aim 2 will focus on other factors that could up-regulate TGF-B1 through this same pathway; and in Aim 3, we will learn if the epithelial and mesenchymal cells in vivo in the lung exhibit the same transduction and transcriptional pathways in health and disease. These studies will provide specific targets for potential therapeutic approaches through the use of small interfering RNAs (siRNA). Thus, in Aim 4, we will show that an siRNA we have designed blocks endogenous TNF-a gene expression. We propose to use this construct as well as an siRNA that degrades MP1 (a key protein in MEK/ERK phosphorylation), and finally an siRNA that will block TGF-B1 expression, and ultimately the development of IPF in our established animal models.