Pathophysiology and Treatment of Endotoxin Shock

内毒素休克的病理生理学和治疗

• 批准号: 07557016
• 负责人: SHIMIZU Takao
• 金额: $ 8.45万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07557016/
• 关键词: endotoxin; platelet activating factor; PAF; tyrosine phosphorylation; MAP kinase

Endotoxin causes systemic collapse, disseminated intravascular coagulation and lethality, by infection of gram-negative bacteria. Although many reports the production of cytokines, the precise mechanism of pathophysiological events remained obscure. By cell biology and molecular biology techniques, we obtained following results.(1) Elucidation of relation between endotoxin and PAF receptorWe established transgenic mice overxpressing PAF receptor. These mice showed severe symptoms of endotoxin shock and death by intravenous administration of small doses of LPS.The lethality was efficiently blocked by the use of PAF receptor antagonists, suggesting that PAF-PAFR is involved in the pathogenesis of endotoxin-induced lethality.(2) Elucidation of LPS action on macrophagesBy incubating of macrophages with bacterial endotoxin, PAFR mRNA was increased several fold after 4h. MAP kinase was also activated, and the activation related to the tyrosine phosphorylation of Raf-1 kinase.

内毒素通过感染革兰氏阴性菌引起全身性虚脱、弥散性血管内凝血和致死。虽然许多报道细胞因子的产生，病理生理事件的确切机制仍然不清楚。通过细胞生物学和分子生物学技术，我们获得了以下结果。(1)内毒素与PAF受体关系的研究建立了PAF受体高表达转基因小鼠。这些小鼠在静脉注射小剂量LPS后表现出严重的内毒素休克和死亡症状，PAF受体拮抗剂的使用有效地阻断了这种致死性，提示PAF-PAFR参与了内毒素诱导的致死性的发病机制。(2)LPS对巨噬细胞作用的研究用细菌内毒素孵育巨噬细胞，4 h后PAFR mRNA增加数倍。MAP激酶也被激活，并且激活与Raf-1激酶的酪氨酸磷酸化有关。

项目成果

Mutoh,H.: "Tissue-specific response of the human platelet-activating factor receptor gene to retinoic acid and thyroid hormone by alternative promoter usage." Proc.Natl.Acad.Sci.U.S.A. 93. 774-779 (1996)

Mutoh,H.：“通过替代启动子使用，人血小板激活因子受体基因对视黄酸和甲状腺激素的组织特异性反应。”

Waga, I.et al.: "Microtrap phosphorylation assay of mitogen-activated protein (MAP) kinases, to detect their activation by lipopolysaccharide." J.Immunol. Method. 190. 71-77 (1996)

Waga, I.et al.：“丝裂原激活蛋白 (MAP) 激酶的 Microtrap 磷酸化测定，以检测脂多糖对它们的激活。”

Ishii, I.et al.: "Alanine exchanges of polar amino acids in the transmembrane domains of a platelet-activating factor receptor generate both constitutively active and inactive mutants with altered affinities and altered cellular responses to their Ligands

Ishii，I.等人：“血小板激活因子受体跨膜域中极性氨基酸的丙氨酸交换产生组成型活性和非活性突变体，其亲和力和细胞对其配体的反应发生改变

Honda, Z. et al: "Gq pathway desensitizes chemotactic receptor-induced calcium signaling viainositol trisphosphate teceptor down-regulation." J, Biol. Chem.270. 4840-4844 (1995)

Honda, Z. 等人：“Gq 通路通过三磷酸肌醇受体下调使趋化受体诱导的钙信号传导脱敏。”

Mori,M.,et al.: "Predominant expression of platelet-activating factor receptor in the rat brain microglia." J.Neurosci.16. 3590-3600 (1996)

Mori,M.,et al.：“大鼠脑小胶质细胞中血小板激活因子受体的主要表达。”