LOW DOSE ALCOHOL--ATTENUATION OF CARDIAC APOPTOSIS

低剂量酒精--心肌细胞凋亡的减弱

• 批准号: 2880981
• 负责人: Jeanie B. MC MILLIN
• 金额: $ 10.47万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2001-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2880981
• 关键词: alcoholic beverage consumption; antioxidants; apoptosis; calcium metabolism; cardiac myocytes; cytochrome c; dosage; fatty acid metabolism; fluorescence microscopy; free radical oxygen; laboratory rat; membrane permeability; membrane potentials; mitochondrial membrane; newborn animals; palmitates

The long-term goal of the proposed research is to understand how cardiac mitochondria initiate apoptosis and how moderate alcohol consumption may act as a therapeutic modality to block or to retard apoptotic signaling associated with the progression of heart disease. Moderate alcohol consumption is linked to a lower risk of coronary artery disease and a decreased risk of ischemic injury. Programmed cell death now appears to play a quantitatively more important role in the loss of myocyte viability than previously recognized. Since both ischemic heart disease and the initiation of apoptosis are linked to changes in intracellular calcium metabolism, we propose to examine the relation of mitochondrial calcium to apoptotic events and how these pathways are modulated by brief but chronic exposure of cardiac myocytes to small concentrations of alcohol. Effects of alcohol on the cardiac cytoskeleton will be monitored to assure absence of toxicity. We are able to visualize directly and quantitate cellular and mitochondrial changes in a longitudinal fashion by using palmitate to induce apoptosis in neonatal rat cardiomyocytes in culture. By using this approach, we propose to elucidate the role of mitochondrial calcium in this process and whether alcohol prevents progression to the mitochondrial permeability transition with a loss in membrane potential and subsequent activation of cell death signaling. By using a combination of biochemical and microscopic tools, the ability of alcohol to attenuate mitochondrial calcium overload leading to the permeability transition and cytochrome c release will be studied. We propose to test whether the anti- oxidant properties of alcoholic beverages or whether direct effects of alcohol block the release of mitochondrially-generated free radicals and the subsequent loss of the mitochondrial membrane potential. Finally, we will look at the role of fatty acid metabolism and ceramide formation on signal transduction pathways that may be individually altered by exposure of cardiac myocytes to low levels of alcohol.

这项拟议研究的长期目标是了解心肌线粒体如何启动细胞凋亡，以及适度饮酒如何作为一种治疗手段来阻断或延缓与心脏病进展相关的凋亡信号。适度饮酒与较低的冠状动脉疾病风险和减少缺血性损伤的风险有关。现在看来，程序性细胞死亡在心肌细胞活力丧失中扮演着比以前所认识到的更重要的角色。由于缺血性心脏病和细胞凋亡的启动都与细胞内钙代谢的变化有关，我们建议研究线粒体钙与细胞凋亡事件的关系，以及这些通路是如何通过短暂但长期的心肌细胞暴露于低浓度的酒精来调节的。酒精对心脏细胞骨架的影响将受到监测，以确保没有毒性。通过使用棕榈酸酯诱导培养的新生大鼠心肌细胞的凋亡，我们能够直接可视化并以纵向方式定量细胞和线粒体的变化。通过这种方法，我们建议阐明线粒体钙在这一过程中的作用，以及酒精是否阻止了线粒体通透性转变的进展，膜电位的丧失以及随后细胞死亡信号的激活。通过生化和显微手段的结合，将研究酒精减轻线粒体钙超载导致的通透性转变和细胞色素c释放的能力。我们建议测试酒精饮料的抗氧化性能，或者酒精的直接作用是否阻止线粒体产生的自由基的释放和随后线粒体膜电位的丧失。最后，我们将看看脂肪酸代谢和神经酰胺形成在信号转导通路上的作用，这些信号转导通路可能会因心肌细胞暴露在低水平的酒精中而单独改变。