Endothelin-1 activates mitogen-activated protein kinases through two independent signalling pathways in rat astrocytes.
Endothelin-1 activates mitogen-activated protein kinases through two independent signalling pathways in rat astrocytes.
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Endothelin-1 通过大鼠星形胶质细胞中的两条独立的信号通路激活丝裂原激活蛋白激酶。
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
K. Goto
中科院分区：
文献类型：
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作者：
Y. Kasuya;Y. Abe;Hiroshi Hama;Takeshi Sakurai;S. Asada;Tomoh Masaki;K. Goto
北方印迹分析和置换研究表明，内皮素（ET）受体在原代培养的大鼠星形胶质细胞中功能性表达为ETB受体。细胞中的促分裂原活化蛋白激酶（MAP激酶）被10 nM ET-1激活，该剂量最大限度地刺激磷酸肌醇水解。这种激活被有效地抑制预处理的细胞与佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA），导致蛋白激酶C（PKC）下调，并轻微抑制预处理与百日咳毒素（PTX）。PMA + PTX预处理可完全抑制ET-1诱导的MAP激酶活性。0.1 nM ET-1也可诱导MAP激酶的激活，但ET-1几乎不刺激磷酸肌醇水解。这种激活被PTX预处理完全抑制，但对PMA预处理不敏感。ET-1刺激的肌醇磷酸的产生不受PTX预处理的影响。这些结果表明，激活MAP激酶继发于ETB受体的刺激与ET-1在大鼠原代培养的星形胶质细胞介导的两个独立的信号通路。PKC依赖性途径和PTX敏感性G蛋白介导的途径。
Northern blot analysis and displacement study revealed that the endothelin (ET) receptor functionally expressed in rat primary cultured astrocytes is the ETB receptor. Mitogen-activated protein kinases (MAP kinases) in the cells were activated by 10 nM ET-1, a dose that maximally stimulated phosphoinositide hydrolysis. This activation was potently inhibited by pretreatment of the cells with phorbol 12-myristate 13-acetate (PMA) which leads to protein kinase C (PKC) down-regulation and was slightly inhibited by pretreatment with pertussis toxin (PTX). Pretreatment of the cells with PMA plus PTX completely inhibited the ET-1-augmented MAP kinase activity. Activation of MAP kinases was also induced by 0.1 nM ET-1, which hardly stimulated phosphoinositide hydrolysis. This activation was fully inhibited by pretreatment with PTX but insensitive to pretreatment with PMA. ET-1-stimulated production of inositol phosphates was not affected by pretreatment with PTX. These results suggest that activation of MAP kinases secondary to stimulation of the ETB receptor with ET-1 in rat primary cultured astrocytes was mediated through two independent signalling pathways. PKC-dependent pathway and PTX-sensitive G protein-mediated pathway.