Development of a conditional T1MP-1 knockout mouse

描述（由申请人提供）：金属蛋白酶组织抑制剂-1（TIMP-1）是一种多效性细胞外蛋白，在炎症或损伤后在脑中显著上调。TIMP-1作为基质金属蛋白酶（MMPs）的蛋白水解活性的内源性调节剂具有充分描述的功能，所述基质金属蛋白酶（MMPs）是在细胞内稳态、适应和组织重塑中起关键作用的胞外酶家族。TIMP-1还具有MMP非依赖性功能，包括抗凋亡活性和营养作用。TIMP-1的这些后一种功能与突触可塑性、神经保护、肿瘤发生和少突胶质细胞分化有关。TIMP-1可由CNS中的多种细胞类型表达：星形胶质细胞响应CNS中的炎性脱髓鞘或细菌感染而稳健地表达TIMP-1，并且已报道神经元在兴奋性毒性损伤后表达TIMP-1。在CNS损伤和炎症过程中，还需要指出的是，TIMP-1也由免疫细胞表达，包括T细胞、巨噬细胞和小胶质细胞。因此，TIMP-1可由多种细胞类型快速表达，从而提供TIMP-1在响应CNS损伤或疾病中的无数潜在作用。目前，只有全球TIMP-1 KO小鼠可用于研究，这意味着TIMP-1的细胞来源仍然是我们理解TIMP-1在大脑中的特定机制作用的混杂变量。为了测试来自特定细胞类型的TIMP-1的产生是否差异性地影响 神经病理学，我们将开发一种必要的新试剂：条件性TIMP-1敲除小鼠（TIMP-1cKO）系。该小鼠系将通过使我们能够直接测试细胞特异性TIMP-1表达是否影响损伤后脑恢复的先天潜力来显著推进我们对TIMP-1及其在CNS中的功能的理解。该提案的第一个目标是开发新的TIMP-1cKO小鼠，然后将其与GFAP-Cre转基因小鼠杂交，以特异性敲除整个CNS星形胶质细胞的TIMP-1表达。然后将对星形胶质细胞特异性TIMP-1 cKO小鼠进行测试，并与全球进行比较。总之，这项工作将：（a）为在各种疾病模型（包括神经系统疾病）中进行TIMP-1的高级研究提供有价值的新试剂，以及（B）这项工作的实验结果将验证TIMP-1 cKO小鼠作为研究TIMP-1细胞特异性缺失的可行新小鼠系。

DESCRIPTION (provided by applicant): Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a pleiotrophic extracellular protein that is dramatically upregulated in the brain following inflammation or injury. TIMP-1 has a well described function as an endogenous regulator of the proteolytic activities of the matrix metalloproteinases (MMPs) a family of extracellular enzymes that play critical roles in cellular homeostasis, adaptation and tissue remodeling. TIMP-1 also has noted MMP-independent functions including antiapoptotic activity and trophic actions. These latter functions of TIMP-1 have been implicated in synaptic plasticity, neuroprotection, oncogenesis and oligodendrocyte differentiation. TIMP-1 can be expressed by a variety of cell types in the CNS: astrocytes robustly express TIMP-1 in response to inflammatory demyelination or bacterial infection in the CNS, and neurons have been reported to express TIMP-1 following excitotoxic injury. In the course of CNS injury and inflammation, it is also important to point out that TIMP-1 is also expressed by immune cells, including T cells, macrophages and microglia. Thus, TIMP-1 can be rapidly expressed by a variety of cell types offering a myriad of potential roles for TIMP-1 in response to CNS injury or disease. Currently, only global TIMP-1KO mice are available for study meaning that the cellular source of TIMP-1 remains a confounding variable to our understanding on the specific mechanistic roles of TIMP-1 in the brain. To test whether production of TIMP-1 from specific cell types differentially impact neuropathology, we will develop an essential new reagent: a conditional TIMP-1 knockout mouse (TIMP-1cKO) line. This mouse line will significantly advance our understanding of TIMP-1 and its functions in the CNS by enabling us to directly test whether cell specific-TIMP-1 expression impacts the innate potential for brain recovery following injury. The first aim of this proposal will be to develop the new TIMP-1cKO mouse, which will then be crossed with the GFAP-Cre transgenic mouse to specifically knockout TIMP-1 expression from astrocytes throughout the CNS. Astrocyte-specific TIMP-1cKO mice will then be tested and compared with global Together this work will, (a) provide a valuable new reagent for advanced study on TIMP-1 in a wide variety of disease models, including neurological diseases, and, (b) experimental results from this work will validate the TIMP-1cKO mouse as a viable new mouse line for study of cell-specific deletion of TIMP-1.