ACTIVATION OF MITOGEN-ACTIVATED PROTEIN KINASE FAMILY IN RAT PITUITARY GH3 CELLS

大鼠垂体 GH3 细胞中有丝分裂原激活蛋白激酶家族的激活

基本信息

批准号：
10671541
负责人：
MIYAZAKI Kohji
金额：
$ 2.5万
依托单位：
Shimane Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10671541/
关键词：
Prolactin Growth hormone TRH MAP kinase myosin light chain kinase CaM kinase II apoptosis bromocriptine 42 MAPキナーゼ細胞内情報伝達系 MAPキナーゼ成長ホルモン

项目摘要

In GH3 cells, we examined the Mitogen-activated protein kinase (MAP kinase) activation induced by thyrotropin-releasing hormone (TRH) and the role of MAP kinase activation in secretory processes and prolactin (PRL) synthesis. Immunoblotting analysis indicated the presence of only 42 kDa MAP kinase in GH3 cells. TRH induced rapid activation of MAP kinase, which reached a maximal peak of 300 A ィイD4oィエD4i at 5-10 min. TRH-induced MAP kinase activation was inhibited completely by PD098059, and 80 % by calphostin C, respectively. Genistein and removal of extracellular Ca2+ also partially inhibited TRH-induced MAP kinase activation. These results suggest that TRH-induced MAP kinase activation is largely PKC-dependent and partially dependent on the Ca2+-dependent tyrosine kinase. CTPcAMP increased MAP kinase activity significantly, and CPTcAMP effects were inhibited by PD098059. TRH-induced prolactin secretion was not affected by exposure to PD098059, but completely blocked by either wortmannin or KN93. Synthesis of PRL induced by TFH was completely blocked by addition PC098059. These results suggest that TRH-induced MAP kinase activation is correlated with synthesis of PRL but not with PRL secretion. TRH increased the PRL synthesis, while growth hormone synthesis largely decreased by TRH. Treatment of GH3 cells with bromocriptine for 48th increased the p38 MAP kinase activity, and simultaneously increased the number of apoptotic cells. SB202190 and SB203580 completely inhibited the bromocriptine-induced p38 MAP kinase activation, and reduced the number of apoptotic cells. We have shown that TRH induces P44/42 MAP kinase activation in GH3 cells. TRH may be involved in PRL secretion through activation of myosin light chain kinase and CaM kinase II, and in PRL synthesis and differentiation of the cells through activation of P44/42 MAP kinase. The p38 MAP kinase activation induced by bromocriptine was strongly involved in induction of apoptosis.

在 GH3 细胞中，我们检查了促甲状腺素释放激素 (TRH) 诱导的丝裂原激活蛋白激酶 (MAP 激酶) 激活，以及 MAP 激酶激活在分泌过程和催乳素 (PRL) 合成中的作用，免疫印迹分析表明仅存在。 GH3 细胞中的 42 kDa MAP 激酶诱导 MAP 激酶快速激活，在 300 A 处达到最大峰值。 5-10 分钟，TRH 诱导的 MAP 激酶激活被 PD098059 完全抑制，钙磷蛋白 C 抑制 80%，细胞外 Ca2+ 的去除也部分抑制了 TRH 诱导的 MAP 激酶激活。激酶激活很大程度上依赖于 PKC，部分依赖于 Ca2+ 依赖的酪氨酸激酶 CTPcAMP 显着增加 MAP 激酶活性，并且 CPTcAMP 具有作用。 TRH 诱导的催乳素分泌不受暴露于 PD098059 的影响，但通过添加 PC098059 完全阻断了 TFH 诱导的 PRL 的合成。 TRH 与 PRL 合成相关，但与 PRL 分泌无关。TRH 增加 PRL 合成，而生长激素合成则大大减少。 TRH.用溴隐亭处理GH3细胞48后，p38 MAP激酶活性增加，同时SB202190和SB203580完全抑制了溴隐亭诱导的p38 MAP激酶激活，并减少了凋亡细胞的数量。研究表明 TRH 可能会诱导 GH3 细胞中 P44/42 MAP 激酶的激活。通过激活肌球蛋白轻链激酶和CaM激酶II参与PRL分泌，并通过激活P44/42 MAP激酶参与细胞的PRL合成和分化。溴隐亭诱导的p38 MAP激酶激活参与诱导细胞凋亡。