ETHANOL AND PLACENTAL TOXICITY SIGNAL CROSS TALK

乙醇和胎盘毒性信号的交互作用

• 批准号: 2894002
• 负责人: STANLEY E. FISHER
• 金额: $ 33.6万
• 依托单位: SUNY DOWNSTATE MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-02-01 至 2001-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2894002
• 关键词: G protein; adenylate cyclase; biological signal transduction; cyclic AMP; diacylglycerols; embryo /fetus toxicology; enzyme activity; ethanol; fetal alcohol syndrome; human tissue; ligands; phosphorylation; placental transfer; protein isoforms; protein kinase C; receptor binding; receptor expression; tissue /cell culture; trophoblast

The placenta is a multifunctional organ of fetal origin, which is critical to normal fetal growth and development. In addition to direct fetal toxicity, ethanol may be toxic to the placenta as well. Ethanol-induced placental toxicity could contribute to the pathophysiology of alcohol related fetal injury. During the course of the current grant, this laboratory has characterized human placental trophoblasts in culture and demonstrated several alterations in cellular physiology. The human trophoblast is the principal functional cell of the human placenta, but it also expresses physiologic properties which are found in other human cell types. The ethanol-treated, cultured trophoblast model system, developed in this laboratory, enables evaluation of molecular biochemistry in readily available, nontransformed human cells. Using this system, we propose to test the fundamental hypothesis: Ethanol alters intracellular signal transduction. In particular, we will concentrate on the effect of ethanol on signal "cross-talk" mediated by protein kinase C (PKC), an important regulatory factor in normal intracellular signal transduction. This laboratory has shown that chronic exposure to ethanol, within a dose range found in man, results in enhancement of ligand-stimulated cAMP production by cultured trophoblasts. Preliminary data indicate that this alteration is not due to quantitative changes in G protein expression. Rather, there is an effective increase in adenylyl cyclase (AC) activity. We propose that this may be due, at least in part, to ethanol-induced activation of PKC and subsequent interaction of PKC with components of the adenylyl cyclase system. This proposal will investigate the biochemical basis for ethanol-induced enhancement of ligand-stimulated cAMP production in the context of PKC mediated signal "cross talk." Using the general model system of the cultured human placental trophoblast, exposed to ethanol in vitro, we propose to: Investigate ethanol-induced changes in components of the AC signalling system which are modulated by PKC "cross- talk;" Use inhibition of PKC to evaluate the role of PKC in ethanol- induced changes in the AC system; Evaluate the effect of ethanol on PKC activity, as it relates to the several phospholipases and diacylglycerol production; Determine the role of phosphatidylethanol as an activator of PKC and its role in signal "cross-talk." The studies should provide new information on the cellular mechanisms by which ethanol alters placental function and, hence, advance our understanding of the pathophysiology of the Fetal Alcohol Syndrome. Additionally, these findings should contribute to the general understanding of the mechanisms by which ethanol affects the biology of many human tissues, including those of the fetus.

胎盘是源于胎儿的多功能器官，这一点至关重要。 胎儿的正常生长发育。除了直接胎儿 毒性，乙醇也可能对胎盘有毒性。乙醇诱导 胎盘毒性可能与酒精的病理生理学有关 与胎儿相关的损伤。在目前的赠款过程中，这 实验室已经鉴定了人胎盘滋养层细胞的培养和 证明了细胞生理学上的几个变化。人类 滋养层细胞是人类胎盘的主要功能细胞，但它 也表达在其他人类细胞中发现的生理特性 类型。乙醇处理培养滋养层细胞模型系统的研制 在这个实验室里，能够评估分子生物化学在 容易获得的、未转化的人类细胞。使用这个系统，我们 建议检验基本假设：乙醇改变细胞内 信号转导。尤其是，我们将重点关注 乙醇对蛋白激酶C(PKC)介导的信号“串扰”的影响 正常细胞内信号转导的重要调节因子。 这个实验室已经证明，长期接触乙醇，在一定剂量内 在人类中发现的范围，导致配体刺激的cAMP增强 由培养的滋养层细胞产生。初步数据显示，这 改变不是由于G蛋白表达的数量变化。 相反，腺酰环化酶(AC)活性有效增加。 我们认为，这可能至少部分归因于乙醇诱导的 激活PKC以及随后PKC与组件的相互作用 腺苷环化酶系统。这项提案将调查生物化学 乙醇促进配体刺激的cAMP产生的基础 在PKC介导的信号“串扰”的背景下。使用通用的 体外培养的人胎盘滋养层细胞模型体系 乙醇在体外，我们建议：研究乙醇诱导的细胞内 交流信令系统中由PKC调制的部件。 Talk；“使用PKC抑制来评估PKC在乙醇中的作用-- 诱发AC系统的改变；评估乙醇对PKC的影响 活性，因为它与几种磷脂酶和二酰甘油有关 生产；测定磷脂酰乙醇作为激活剂的作用 PKC及其在信号“串扰”中的作用。这些研究应该提供新的 乙醇改变胎盘的细胞机制的信息 功能，从而促进我们对心脏的病理生理学的理解。 胎儿酒精综合症。此外，这些发现应该 有助于全面理解乙醇的作用机理 影响许多人体组织的生物学，包括胎儿的组织。