Initial functional characterization of TRUSS-deficient mice

描述（由申请人提供）：TNF-α受体TNF-R1的信号传导对于炎症、组织损伤和先天免疫的发展是必需的。最近的研究，从我们的实验室已经导致发现和TRUSS（TNF-R1无处不在的信号和支架蛋白），一个无处不在的和以前未知的蛋白质，作为一个变阻器，以增加TNF-R1诱导的NF-κ B的激活特性？B、JNK与细胞凋亡。为了评估TRUSS在TNF-R1信号传导中的体内功能，我们建立了携带floxed truss等位基因的小鼠，以允许条件性TRUSS缺失。在初步的研究中，我们已经表明，这些小鼠经历Cre介导的重组在桁架位点导致TRUSS缺陷。我们的初步研究还表明，TRUSS-/-小鼠受到保护，免于肝细胞凋亡和TNF- R1信号转导诱导的急性肝衰竭。现在需要进一步的研究来探索这些最近创建和验证的小鼠的表型。这项探索性/开发性R21应用的目的是：（i）评价肝细胞和内皮细胞中条件性TRUSS缺陷对TNF-R1诱导的肝细胞凋亡和急性肝炎的影响，以及（ii）检验TRUSS通过促进持续JNK激活的能力增强TNF-R1诱导的细胞凋亡的假设。这些目标将通过两个具体目标来实现。使用整体TRUSS缺陷小鼠、肝细胞特异性TRUSS缺陷小鼠和内皮细胞特异性TRUSS缺陷小鼠，具体目标1将检验肝细胞凋亡和急性致死性肝炎依赖于TRUSS的假设。具体目标2将检验TNF-R1诱导的肝细胞凋亡中TRUSS的需求是促进持续的JNK活化，进而通过线粒体途径活化半胱天冬酶的假设。据我们所知，本提案中描述的floxed桁架小鼠是我们实验室独有的。拟议的研究将为TRUSS在体内的功能提供新的见解，并将成为R 01新应用的基础。其他人最近的研究也表明TRUSS与阿尔茨海默病、乳腺癌和肺癌有关。因此，除了上述目标外，我们的目标是使这些小鼠可用于其他研究人员，他们的工作重点是这个未充分研究的基因。

DESCRIPTION (provided by applicant): Signaling by the TNF-¿ receptor, TNF-R1, is necessary for the development of inflammation, tissue injury and innate immunity. Recent studies from our laboratory have led to the discovery and characterization of TRUSS (TNF-R1 Ubiquitous Signaling and Scaffolding protein), a ubiquitous and previously unknown protein that serves as a rheostat to augment TNF-R1-induced activation of NF-?B, JNK and apoptosis. To allow assessment of the in vivo function of TRUSS in TNF-R1 signaling we have created mice bearing floxed truss alleles to allow conditional TRUSS deletion. In preliminary studies, we have shown that these mice undergo Cre-mediated recombination at the truss locus resulting in TRUSS deficiency. Our preliminary studies also indicate that TRUSS-/- mice are protected from hepatocyte apoptosis and acute hepatic failure induced by TNF- R1 signaling. Additional studies are now necessary to explore the phenotype of these recently created and validated mice. The goals of this exploratory/developmental R21 application are to: (i) evaluate the consequences of conditional TRUSS deficiency in hepatocytes and endothelial cells on TNF-R1-induced hepatocyte apoptosis and acute hepatitis and (ii) test the hypothesis that TRUSS augments TNF-R1-induced apoptosis through its ability to promote sustained JNK activation. These goals will be addressed by two specific aims. Using global TRUSS-deficient mice, hepatocyte-specific TRUSS deficient mice and endothelial cell-specific TRUSS deficient mice, specific aim 1 will test the hypothesis that hepatocyte apoptosis and acute fatal hepatitis are dependent on TRUSS. Specific aim 2 will test the hypothesis that the requirement for TRUSS in TNF-R1-induced hepatocyte apoptosis is to promote sustained JNK activation, which in turn activates caspases via the mitochondrial pathway. To our knowledge, the floxed truss mice described in this proposal are unique to our lab. The proposed studies will provide new insights into TRUSS function in vivo and will form the basis of a new R01 application. Recent studies by others have also implicated TRUSS in Alzheimer's disease and breast and lung cancer. Thus, in addition to the goals outlined above, our goal is to make these mice available to others investigators whose work focuses on this understudied gene.