EFFECTS OF ETHANOL ON APOPTOSIS

慢性酒精中毒与组织损伤机制的研究进展 与胎儿酒精综合征相关的发育异常有 未知。然而，酒精引起的组织损伤通常与 对于以程序性细胞死亡为特征的孤立细胞丢失， 细胞凋亡，而不是坏死性损伤形式。在这方面，我们 最近证明乙醇显著地使细胞对 抑制胰岛素样细胞酪氨酸激酶活性诱导的细胞凋亡 生长因子I受体(IGF-IR)，一种对生存至关重要的受体 在许多细胞类型中。我们假设酒精引起的毒性是 至少部分地由IGF-IR的表达和激活来调节。 生长紧密的小鼠成纤维细胞和神经胶质细胞系 因子调节，特别是IGF-I，将作为体外模型用于 检测乙醇对多种细胞凋亡启动方式的影响。这个 乙醇促进细胞凋亡与IGF-IR相关 表达和酪氨酸自动磷酸化，以及表达和 激活关键的近端信号介质，如胰岛素相关 底物-1(IRS-1)、Src-同系物2/α-胶原(Shc)和磷脂酰基 肌醇3-激酶。乙醇对胰岛素样生长因子-IR和细胞凋亡的影响 在啮齿动物和鸡的原代神经细胞培养中以及在 活体模型。具体地说，我们将分析乙醇对 开发鸡，这是胎儿酒精综合征的已建立模型，以及 神经脊细胞死亡与IGF-IR发育动态的关系 表情。细胞死亡也将使用植入性生物扩散进行研究。 酒精中毒小鼠的小室。最后，我们将用一本小说 鉴定IGF-I诱导物的功能表达克隆方法 生存基因。我们将研究乙醇对其表达的影响。 这些基因，并决定了这些基因的过度表达 使细胞对乙醇的促凋亡作用不敏感。

The mechanisms of tissue injury in the setting of chronic alcoholism and developmental abnormalities associated with fetal alcohol syndrome are unknown. However, alcohol-induced tissue injury is generally associated with isolated cell loss that is characteristic of programmed cell death, apoptosis, rather than necrotizing forms of injury. In this regard, we have recently demonstrated that ethanol markedly sensitizes cells to apoptosis by suppressing the tyrosine kinase activity of the insulin-like growth factor I receptor (IGF-IR), a receptor that is key to the survival of many cell types. We hypothesize that ethanol-induced toxicity is modulated, at least in part, by expression and activation of the IGF-IR. Murine fibroblasts and neuroglial cell lines that exhibit tight growth factor regulation, IGF-I in particular, will be used as in vitro models to test the effect of ethanol on various modes of apoptosis initiation. The enhancement of apoptosis by ethanol will be correlated with IGF-IR expression and tyrosine auto-phosphorylation, and the expression and activation of key proximal signal mediators such as insulin-related substrate-1 (IRS-1), Src-homology 2/alpha-collagen (Shc), and phosphatidyl inositol 3-kinase. The effect of ethanol on IGF-IR and apoptosis will then be studied in rodent and chicken primary neuronal cell cultures and in vivo models. Specifically, we will analyze ethanol effects on the developing chicken, an established model for fetal alcohol syndrome, and relate neural crest cell death to the developmental dynamics of IGF-IR expression. Cell death will also be studied using implantable biodiffusion chamber in ethanol-intoxicated mice. Finally, we will use a novel functional expression cloning approach to identify IGF-I-inducible survival genes. We will study the effect of ethanol of the expression of these genes, and determine whether the overexpression of the genes desensitizes cells to the pro-apoptotic effect of ethanol.