Cellular mechanisms that promote or prevent lipotoxicity

促进或预防脂毒性的细胞机制

• 批准号: 6777535
• 负责人: JEAN E. SCHAFFER
• 金额: $ 22.95万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6777535
• 关键词: CHO cells; adipocytes; apoptosis; biological signal transduction; cytotoxicity; dietary lipid; gel electrophoresis; gene expression; gene mutation; heart failure; insulin sensitivity /resistance; lipid metabolism; long chain fatty acid; mass spectrometry; northern blottings; oleate; palmitates; pancreatic islets; peroxisome proliferator activated receptor; polymerase chain reaction; saturated fatty acids; tissue /cell culture; western blottings

DESCRIPTION (provided by applicant): Excess lipid accumulation in non-adipose tissues is associated with insulin resistance, pancreatic a cell apoptosis and heart failure. Previous work has shown that high concentrations of the saturated fatty acid palmitate, but not mono-unsaturated oleate, leads to apoptosis in cultured cells by a mechanism involving the generation of reactive intermediates. Furthermore, palmitate-induced apoptosis can be rescued by co-incubation with oleate. The goal of the present study is to characterize mechanisms of lipotoxicity caused by cellular accumulation of saturated long chain fatty acids, and to gain insight into the fundamental cellular mechanisms through which the common saturated and unsaturated dietary lipids, palmitic and oleic acids, exert their differential effects on cell survival. We will test the hypothesis that cellular proteins participate in channeling of specific long chain fatty acids to different metabolic fates. In Specific Aim 1, we will use Chinese hamster ovary (CHO) cells as a model system in which to study the lipid metabolic and signaling pathways responsible for fatty acid-induced apoptosis. In Specific Aim 2, we will isolate and characterize mutant CHO cell lines that are resistant to palmitate-induced apoptosis. In Specific Aim 3, we will identify the mutations that confer palmitate-resistance in these mutant CHO cells. Through this screen we will identify proteins that participate in channeling palmitic and oleic acids to distinct metabolic fates. The results of these studies will characterize a fundamental aspect of cellular lipid homeostasis. Moreover, these studies will provide new insights into the cytotoxic response to excess lipid accumulation in non-adipose tissues observed in diseases such as diabetes, lipodystrophies, and heart failure.

描述（由申请人提供）：非脂肪组织中的脂质过量积累与胰岛素抵抗，胰腺凋亡和心力衰竭有关。先前的工作表明，高浓度的饱和脂肪酸棕榈酸酯，但不是单一的不饱和饮食，从而通过涉及反应性中间体产生的机制导致培养细胞的凋亡。此外，可以通过与Oleate共同培养棕榈酸酯引起的凋亡。本研究的目的是表征由饱和长链脂肪酸的细胞积累引起的脂蛋白毒性机制，并深入了解基本的细胞机制，通用饱和和不饱和的饮食脂质，棕榈酸和油酸对这些机制产生了对细胞生存的不同影响。我们将检验以下假设：细胞蛋白参与将特定长链脂肪酸引导到不同代谢命运的假设。在特定目标1中，我们将使用中国仓鼠卵巢（CHO）细胞作为模型系统，在其中研究负责脂肪酸诱导凋亡的脂质代谢和信号传导途径。在特定的目标2中，我们将分离并表征对棕榈酸酯诱导的凋亡具有抗性的突变CHO细胞系。在特定目标3中，我们将确定在这些突变CHO细胞中赋予棕榈酸酯抗性的突变。通过此屏幕，我们将确定参与将棕榈酸和油酸转移到不同代谢命运的蛋白质。这些研究的结果将表征细胞脂质稳态的基本方面。此外，这些研究将提供对在糖尿病，脂肪营养不良和心力衰竭等疾病中观察到的非脂肪组织中过量脂质积累的细胞毒性反应的新见解。