Differential effects of systemic ethanol administration on protein kinase Cε, γ, and β isoform expression, membrane translocation, and target phosphorylation:: Reversal by chronic ethanol exposure
Differential effects of systemic ethanol administration on protein kinase Cε, γ, and β isoform expression, membrane translocation, and target phosphorylation:: Reversal by chronic ethanol exposure
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DOI：
10.1124/jpet.106.110890
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发表时间：
2006-12-01
影响因子：
3.5
通讯作者：
Morrow, A. L.
中科院分区：
文献类型：
--
作者：
Kumar, S.;Lane, B. M.;Morrow, A. L.
系统性乙醇给药改变了脑中蛋白激酶C（PKC）的活性，但乙醇对特定亚型表达和转位的影响尚不清楚。向大鼠施用乙醇（2g/kg i. p.）或生理盐水，并通过Western印迹分析测量胞质和膜组分中的PKC水平。在10分钟时，胞浆中的PKC β表达增加，大脑皮层的膜（P2）部分中的PKC β表达减少。在60分钟时，P2部分中的PKC β表达增加了42.2 +/-12%，但胞浆水平不变。相比之下，P2组分中的PKC β在乙醇给药后60分钟降低了32.7 +/- 7%，但在10分钟时未降低。细胞溶质中的PKC γ水平在乙醇给药后10分钟降低，60分钟不变。P2组分中的PKC γ表达在乙醇给药后10分钟和60分钟分别增加36 +/- 10和144 +/- 52%，而细胞溶质水平不变。乙醇给药后60 min，GABA A受体β链丝氨酸磷酸化减少，N-甲基-D-天冬氨酸受体NR 1亚基磷酸化增加。急性乙醇给药对海马中PKC亚型水平没有影响。乙醇的挑战并没有改变PKC亚型的表达在P2部分的大脑皮层慢性乙醇管理。这些研究结果表明，急性乙醇管理改变PKC的合成和易位的亚型和脑区的具体方式，导致受体的丝氨酸磷酸化的改变。此外，长期乙醇管理防止乙醇诱导的PKC表达的P2部分，其中PKC与乙醇响应离子通道相互作用的改变。
Systemic ethanol administration alters protein kinase C (PKC) activity in brain, but the effects of ethanol on the expression and translocation of specific isoforms are unknown. Rats were administered ethanol (2 g/kg i.p.) or saline and PKC levels were measured in the cytosolic and membrane fractions by Western blot analysis. PKC epsilon expression was increased in the cytosol and decreased in the membrane (P2) fraction of cerebral cortex at 10 min. At 60 min, expression of PKC epsilon in the P2 fraction was increased by 42.2 +/- 12%, but cytosolic levels were unchanged. In contrast, PKC epsilon in the P2 fraction was decreased 32.7 +/- 7% at 60 min but not at 10 min post-ethanol administration. PKC gamma levels in the cytosol were reduced at 10 min post-ethanol administration and unchanged at 60 min. PKC epsilon expression was increased 36 +/- 10 and 144 +/- 52% in the P2 fraction both at 10 and 60 min post-ethanol administration, whereas cytosolic levels were unchanged. Serine phosphorylation of GABA A receptor beta-chain was reduced, and phosphorylation of N-methyl-D-aspartate receptor NR1 subunit was increased 60 min following ethanol administration. There was no effect of acute ethanol administration on PKC isoform levels in the hippocampus. Ethanol challenge did not alter PKC isoform expression in the P2 fraction of cerebral cortex following chronic ethanol administration. These findings suggest that acute ethanol administration alters PKC synthesis and translocation in an isoform and brain region specific manner that leads to alterations in serine phosphorylation of receptors. Furthermore, chronic ethanol administration prevents ethanol-induced alterations in PKC expression in the P2 fraction, where PKC interacts with ethanol-responsive ion channels.