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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GH 3细胞中，我们研究了促甲状腺激素释放激素（TRH）诱导的有丝分裂原活化蛋白激酶（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GH 3细胞中仅存在42 kDa的MAP激酶。TRH诱导MAP激酶的快速激活，其在5-10 min时达到300 A的最大峰值，PD 098059和calphostin C分别完全抑制TRH诱导的MAP激酶激活，抑制率分别为80%。Genistein和细胞外Ca ~（2+）的去除也部分抑制TRH诱导的MAP激酶激活。这些结果表明，TRH诱导的MAP激酶激活在很大程度上是PKC依赖性的，部分依赖于Ca 2+依赖性酪氨酸激酶。CTPcAMP显著增加MAP激酶活性，PD 098059可抑制CPTcAMP的作用。TRH诱导的催乳素分泌不受暴露于PD 098059的影响，但完全阻断渥曼青霉素或KN 93。加入PC 098059可完全阻断TFH诱导的PRL合成。这些结果表明，TRH诱导的MAP激酶激活与PRL的合成，但不与PRL分泌。TRH增加PRL的合成，而生长激素的合成大大减少TRH。溴隐亭处理GH 3细胞48 h后，p38 MAP激酶活性增加，凋亡细胞数增加。SB 202190和SB 203580完全抑制溴隐亭诱导的p38 MAP激酶激活，并减少凋亡细胞的数量。我们已经证明，TRH诱导P44/42 MAP激酶在GH 3细胞中的激活。TRH可能通过激活肌球蛋白轻链激酶和CaM激酶II参与PRL分泌，通过激活P44/42 MAP激酶参与PRL合成和细胞分化。溴隐亭诱导的p38 MAP激酶激活强烈参与诱导细胞凋亡。