TARGETED DISRUPTION OF THE 5-LIPOXYGENASE GENE IN MICE

酶5-脂氧合酶催化形成的第一步 白三烯。这些化合物显示出广泛的生物学特性。 包括趋化动力学和趋化活性在内的影响 粒细胞、支气管痉挛作用、微血管的诱导 通透性导致血浆渗漏和刺激呼吸道粘膜 分泌物。5-脂氧合酶抑制剂和白三烯受体的应用 拮抗剂已将白三烯及其作用与 炎症性疾病的病理生理学，如变应性鼻炎， 哮喘和肠道疾病，但非特异性药物作用和残留 白三烯的合成阻碍了对其作用的清楚了解 白三烯与健康和疾病。我们建议进行实验 为了阐明5-脂氧合酶途径在小鼠体内的作用 完全消除基因的同源重组技术 功能和生成的白三烯的形成。5-脂氧合酶基因 将在正常小鼠身上详细研究该基因和 染色体位点的特征。一种5-脂氧合酶靶向构建 将被植入胚胎干细胞和携带有 就会产生灭活基因。纯合子零等位基因小鼠将是 5-脂氧合酶基因的表型效应研究 失活和几种髓系细胞类型的特征将是 在生化和功能参数方面。最后，有几个 小鼠体内炎症和过敏模型将被测试 5-脂氧合酶产物的参与。我们预计这些研究将 全面、清晰地了解5-脂氧合酶基因的功能 在单一的、明确的物种中。

The enzyme 5-lipoxygenase catalyzes the first step in the formation of leukotrienes. These compounds exhibit a broad range of biological effects including chemokinetic and chemotactic activity towards granulocytes, bronchospastic action, induction of microvascular permeability leading to plasma leakage and stimulation of airway mucous secretion. The use of 5-lipoxygenase inhibitors and leukotriene receptor antagonists have linked the leukotrienes and their actions to the pathophysiology of inflammatory disorders such as allergic rhinitis, asthma and bowel disease, but non-specific drug effects and residual leukotriene synthesis have prevented a clear picture of the role of leukotrienes in health and disease. We propose to undertake experiments to clarify the role of the 5-lipoxygenase pathway in mice by using the technique of homologous recombination to completely abrogate gene function and resultant leukotriene formation. 5-Lipoxygenase gene expression will be studied in detail in normal mice and the gene and chromosomal locus characterized. A 5-lipoxygenase targeting construct will be inserted into embryonic stem cells and mice carrying the inactivated gene will be generated. Homozygous null allele mice will be investigated fore the phenotypic consequences of 5-lipoxygenase gene inactivation and several myeloid cell types will be characterized with respect to biochemical and functional parameters. Finally, several murine in vivo inflammatory and anaphylactic models will be tested for the involvement of 5-lipoxygenase products. We expect these studies to give a complete and clear insight into 5-lipoxygenase gene function within a single, defined species.