ETHANOL AND MAP KINASE CASCADE

描述：（改编自研究者摘要）长期 该项目的目标是确定以下因素的机制和后果： 乙醇对酪氨酸激酶（TK）介导的细胞信号传导的影响， 丝裂原活化蛋白激酶（MAPK）。 初步结果表明 乙醇调节这两种激酶。 在肝细胞（BNLCL 2）和大鼠中 肝细胞，乙醇显着增强MAPK激活血清。 这不是由于MAPK蛋白或物理相互作用的上调 乙醇和MAPK（p42和p44）之间的关系，因此可能是由于 调节受体后信号步骤。 核心假设是， 乙醇调节血清刺激的TK和Ras-Raf-MAPKK级联反应， MAPK的增强及其向细胞核的移位。 大鼠 肝细胞将是该提案的主要模型。 有三个目标： 目标1. 确定血清刺激酪氨酸和MAP的药理作用 大鼠肝细胞中的激酶。 血清激活的MAPK将在 乙醇（10-100 mM）处理（2-4天）的大鼠肝细胞。 接下来这些 将在对照组（CH）和乙醇喂养组的肝细胞中检测参数 (EH)大鼠 Aim II. 为了确定乙醇增强的机制， 血清刺激的MAPK。 参与Ras活化（活性Ras GTP形式） 和Ras-Raf相互作用在这种乙醇效应将被调查。 目的 三. 探讨乙醇对MAPK核转位的影响， 下游相关性。 MAPK在乙醇处理的细胞核中的表达 将测定肝细胞（Aim 1）。 其次，它在CH核中的水平 和EH（+血清刺激）将被建立。 MAPK的后果 增强c-PLA 2及其核转位对 将确定急性期蛋白。 意义：该项目将 建立乙醇的作用机制和分子靶点 增强血清刺激的MAPK。 关于核效应的新知识 乙醇对MAPK的影响。 乙醇增强的MAP激酶可能 在细胞质和细胞核之间出现一个重要的联系， 乙醇的反应。 这种乙醇作用的分子解释 提供了设计治疗工具来检测、治疗和 防止酒精引起的肝损伤。

DESCRIPTION: (Adapted from the Investigator's Abstract) The long-term OBJECTIVE of the project is to determine the mechanism and consequences of ethanol effects on cell signaling mediated via tyrosine kinase (TK) and mitogen activated protein kinases (MAPK). Preliminary results suggest that ethanol modulated both kinases. In liver cells (BNLCL2) and rat hepatocytes, ethanol dramatically potentiates MAPK activation by serum. This is not due to upregulation of MAPK protein or physical interaction between ethanol and MAPK (p42 and p44) and therefore may be due to modulation on post-receptor signaling steps. The central hypothesis is that ethanol modulates serum-stimulated TK and Ras-Raf-MAPKK cascade leading to potentiation of MAPK and its translocation into the nucleus. Rat hepatocytes will be the major model of the proposal. There are three aims: Aim 1. To determine pharmacology of serum stimulated tyrosine and MAP kinases in rat hepatocytes. Serum activated MAPK will be determined in ethanol (10-100 mM) treated (2-4 days) rat hepatocytes. Next these parameters will be tested in hepatocytes from control (CH) and ethanol-fed (EH) rats. Aim II. To determine the mechanism of ethanol potentiation of serum stimulated MAPK. Involvement of Ras activation (active Ras GTP form) and Ras-Raf-interaction in this ethanol effect will be investigated. Aim III. To determine nuclear translocation of MAPK by ethanol and its downstream relevance. MAPK levels in the nucleus of ethanol-treated hepatocytes (Aim1) will be determined. Next its level in the nuclei of CH and EH (+ serum stimulation) will be established. Consequences of the MAPK potentiation on c-PLA2 and of its nuclear translocation on the expression of acute phase proteins will be ascertained. Significance: This project will establish the mechanism and molecular target(s) involved in ethanol potentiation of serum stimulated MAPK. New knowledge on the nuclear effects of ethanol on MAPK will be gained. Ethanol potentiated MAP Kinase may emerge an as important link between cytosol and nucleus to elicit nuclear responses to ethanol. Such molecular elucidation of the ethanol actions offers the potential to design therapeutic tools to detect, treat, and prevent ethanol-induced liver injury.