Glia-conditioned medium induces de novo synthesis of tyrosine hydroxylase and increases dopamine cell survival by differential signaling pathways
Glia-conditioned medium induces de novo synthesis of tyrosine hydroxylase and increases dopamine cell survival by differential signaling pathways
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DOI：
10.1002/jnr.10704
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发表时间：
2003-09-15
影响因子：
4.2
通讯作者：
Mena, MA
中科院分区：
文献类型：
--
作者：
de Bernardo, S;Canals, S;Mena, MA
中脑星形胶质细胞条件培养基（GCM）大大增加多巴胺（DA）的表型表达，它也保护从自发性和毒素诱导的细胞死亡中脑文化。在这项研究中，我们研究了与这些影响有关的信号通路。5 μ M的Genistein（一种酪氨酸激酶受体抑制剂）和KT-5720（一种蛋白激酶A抑制剂）阻断了GCM诱导的对DA表型表达和DA细胞存活的影响，但没有消除星形胶质细胞（胶质细胞酸性蛋白阳性; GFAP（+））过程的增加。我们分析了磷脂酰肌醇-3激酶（PI-3 K）对TH诱导和细胞存活的作用，以及PI-3 K抑制剂LY-294002和渥曼青霉素，以及有丝分裂原活化蛋白激酶（MAPK）磷酸化的作用与PD-98059，一种p-ERK 1/2 MAPK抑制剂。LY-294002在20-30 μ M阻断了GCM诱导的TH表达和DA细胞存活的作用，但没有消除增加的星形胶质细胞过程。20和40 μ M的PD-98059阻断了GCM诱导的对DA表型、细胞存活和GFAP表达的作用。然而，10 nM的staurosporine（一种蛋白激酶C抑制剂）仅阻断GCM诱导的中脑细胞凋亡保护作用。本文提供的数据显示酪氨酸激酶受体、cAMP依赖性蛋白激酶、P1 - 3 K和MAPK信号传导途径涉及GCM诱导的TH+细胞的从头合成以及DA细胞凋亡，并且这些作用与GFAP表达增加无关。PKC抑制剂仅消除GCM诱导的中脑神经元存活的影响，表明DA表型表达和存活的信号通路可能是独立的。(C)2003 Wiley-Liss，Inc.
The mesencephalic astroglia-conditioned medium (GCM) greatly increases dopamine (DA) phenotype expression, and it also protects from spontaneous and toxin-induced cell death in midbrain cultures. In this study, we have investigated the signaling pathways implicated in those effects. Genistein at 5 muM, an inhibitor of tyrosine kinase receptors, and KT-5720, a protein kinase A inhibitor, blocked the GCM-induced effects on DA phenotype expression and DA cell survival but did not abolish the increased astrocytic (glial fibrillary acidic protein-positive; GFAP(+)) processes. We analyzed the role of phosphatidylinositol-3 kinase (Pl-3K) on TH induction and cell survival, with the Pl-3K inhibitors LY-294002 and wortmannin, and the role of the phosphorylation of mitogen-activated protein kinase (MAPK) with PD-98059, a p-ERK1/2 MAPK inhibitor. LY-294002 at 20-30 muM blocked the GCM-induced effects on TH expression and DA cell survival but did not abolish the increased astrocytic processes. PD-98059 at 20 and 40 muM blocked the GCM-induced effects on DA phenotype, cell survival, and GFAP expression. However, staurosporine at 10 nM, a protein kinase C inhibitor, only blocked the protective effects induced by GCM on midbrain cell apoptosis. The data presented herein show that tyrosine kinase receptors, cAMP-dependent protein kinase, Pl-3K, and MAPK signaling pathways are implicated in de novo synthesis of TH+ cells induced by GCM as well as in DA cell apoptosis and that these effects are unrelated to increased GFAP expression. PKC inhibitors only abolished the GCM-induced effects on midbrain neuronal survival, suggesting that signaling pathways for DA phenotype expression and survival may be independent. (C) 2003 Wiley-Liss, Inc.