Ethanol Activation of Protein Kinase A Regulates GABAA α1 Receptor Function and Trafficking in Cultured Cerebral Cortical Neurons
Ethanol Activation of Protein Kinase A Regulates GABAA α1 Receptor Function and Trafficking in Cultured Cerebral Cortical Neurons
复制标题
DOI：
10.1124/jpet.112.201954
复制
发表时间：
2013-05-01
影响因子：
3.5
通讯作者：
Morrow, A. Leslie
中科院分区：
文献类型：
--
作者：
Carlson, Stephen L.;Kumar, Sandeep;Morrow, A. Leslie
乙醇暴露产生GABA能信号的改变，与依赖和戒断有关。以前，我们证明了乙醇诱导的蛋白激酶C（PKC）γ信号选择性地有助于GABA（A）α 1突触受体活性和表面表达的变化。在这里，我们证明了蛋白激酶A（PKA）在短暂的乙醇暴露过程中对GABA（A）受体适应产生相反的影响。在培养18天后测试来自第0-1天大鼠幼仔的大脑皮质神经元。受体运输进行了评估，Western印迹分析，并使用全细胞膜片钳记录诱发和微型抑制性突触后电流（mIPSC）的反应，测量功能的变化。一小时的乙醇暴露增加了膜相关的PKC和PKA，但稳定状态的GABA（A）α 1亚基水平得以维持。SP-腺苷3 '，5'-环状单硫代磷酸三乙胺单独激活PKA可增加GABA（A）α 1亚基表面表达和唑吡坦增强GABA反应，而乙醇与PKA抑制剂RP-腺苷3 '，5'-环状单硫代磷酸三乙胺共同暴露可降低α 1亚基表达和唑吡坦反应。暴露于PKC抑制剂calphostin-C与乙醇模拟直接PKA激活的效果。PKA调节对mIPSC衰变tau的影响与其对唑吡坦存在下诱发的GABA电流的影响一致。总体而言，结果表明PKA与PKC作用于含α 1的GABA（A）受体，介导乙醇暴露的GABA能效应，并可能为治疗酒精依赖/戒断提供重要靶点。
Ethanol exposure produces alterations in GABAergic signaling that are associated with dependence and withdrawal. Previously, we demonstrated that ethanol-induced protein kinase C (PKC) gamma signaling selectively contributes to changes in GABA(A) alpha 1 synaptic receptor activity and surface expression. Here, we demonstrate that protein kinase A (PKA) exerts opposing effects on GABA(A) receptor adaptations during brief ethanol exposure. Cerebral cortical neurons from day 0-1 rat pups were tested after 18 days in culture. Receptor trafficking was assessed by Western blot analysis, and functional changes were measured using whole-cell patch-clamp recordings of evoked and miniature inhibitory postsynaptic current (mIPSC) responses. One-hour ethanol exposure increased membrane-associated PKC and PKA, but steady-state GABA(A) alpha 1 subunit levels were maintained. Activation of PKA by Sp-adenosine 3',5'-cyclic monophosphothioate triethylamine alone increased GABA(A) alpha 1 subunit surface expression and zolpidem potentiation of GABA responses, whereas coexposure of ethanol with the PKA inhibitor Rp-adenosine 3',5'-cyclic monophosphothioate triethylamine decreased alpha 1 subunit expression and zolpidem responses. Exposure to the PKC inhibitor calphostin-C with ethanol mimicked the effect of direct PKA activation. The effects of PKA modulation on mIPSC decay tau were consistent with its effects on GABA currents evoked in the presence of zolpidem. Overall, the results suggest that PKA acts in opposition to PKC on alpha 1-containing GABA(A) receptors, mediating the GABAergic effects of ethanol exposure, and may provide an important target for the treatment of alcohol dependence/withdrawal.