TNF-INDUCED ACTIVATION OF PHOSPHOLIPASE A2

TNF 诱导的磷脂酶 A2 激活

基本信息

批准号：
2458087
负责人：
SCOTT M LASTER
金额：
$ 10.33万
依托单位：
NORTH CAROLINA STATE UNIVERSITY RALEIGH
依托单位国家：
美国
项目类别：
财政年份：
1993
资助国家：
美国
起止时间：
1993-08-01 至 1999-07-31
项目状态：
已结题

项目摘要

Tumor necrosis factor-alpha (TNF) is a cytokine which can cause cell death. The goal of our laboratory is to define the intracellular pathway which leads to TNF-induced lysis and to determine how that pathway is regulated. The TNF-induced lytic response is accompanied by the activation of a cellular phospholipase. Results from our laboratory suggest that by understanding the mechanisms which regulate the activity of this enzyme we will greatly enhance our understanding of the underlying causes of susceptibility and resistance to TNF. The experiments we will perform will utilize the cell line C3HA since this cell line displays a phenotype which is representative of most normal cell types, it is resistant to TNF but can be sensitized with inhibitors of transcription or translation (ITT). Our first aim will be to identify the phospholipase which is activated in C3HA cells following treatment with TNF and ITT which, based on our preliminary experiments, is likely to be the high molecular weight cytoplasmic form of PLA2 known as cPLA2. Our second aim will be to define the signals which are necessary for the activation of this enzyme by TNF and ITT. Ca++, phosphorylation, and proteolysis are the signals we will investigate. Our third aim will be to determine what is different about cells which are susceptible to TNF which permits TNF, on its own, in the absence of ITT, to induce the activity of this phospholipase. We will examine the phospholipase itself, and the signals which control its activity in cells expressing the E1A gene product and tumor-derived cell lines which are susceptible to TNF. Finally, we will ask how the adenovirus E3 region 14.7 kDa protein, heat and sodium arsenite can prevent the TNF-induced activation of this enzyme. Again, experiments have been planned to examine both the enzyme and the signals which are necessary for its activation.

肿瘤坏死因子-α（TNF）是一种细胞因子，可导致细胞死亡。我们实验室的目标是定义细胞内途径导致 TNF 诱导的裂解并确定该途径是如何进行的受监管。 TNF 诱导的裂解反应伴随着细胞磷脂酶的激活。我们实验室的结果建议通过了解调节活动的机制我们将极大地加深对这种酶的了解 TNF 易感性和耐药性的根本原因。这我们将进行的实验将利用细胞系 C3HA，因为这细胞系显示出代表大多数正常细胞的表型细胞类型，它对 TNF 有抵抗力，但可以用抑制剂致敏转录或翻译（ITT）。我们的首要目标是确定治疗后 C3HA 细胞中的磷脂酶被激活根据我们的初步实验，TNF 和 ITT 很可能是 PLA2 的高分子量细胞质形式，称为 cPLA2。我们的第二个目标是定义必要的信号 TNF 和 ITT 激活该酶。 Ca++、磷酸化和蛋白水解是我们要研究的信号。我们的第三个目标是确定对 TNF 敏感的细胞有何不同它允许 TNF 在没有 ITT 的情况下单独诱导该磷脂酶的活性。我们将检查磷脂酶其本身，以及控制其在表达细胞中的活性的信号 E1A基因产物和易感的肿瘤来源细胞系至肿瘤坏死因子。最后我们要问腺病毒E3区14.7 kDa如何蛋白质、热和亚砷酸钠可以阻止 TNF 诱导的激活这种酶。同样，计划进行实验来检查酶及其激活所需的信号。