SMOOTH MUSCLE CELL MEMBRANE DURING ATHEROGENESIS

动脉粥样硬化过程中的平滑肌细胞膜

• 批准号: 6390953
• 负责人: Thomas N. Tulenko
• 金额: $ 31.51万
• 依托单位: LANKENAU INSTITUTE FOR MEDICAL RESEARCH
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-01 至 2004-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6390953
• 关键词: artery; atherosclerosis; atherosclerotic plaque; cell proliferation; cholesterol; collagen; cytoprotection; estrogens; human tissue; laboratory rabbit; membrane biogenesis; membrane lipids; protein biosynthesis; tissue /cell culture; vascular smooth muscle

Atherosclerosis continues to be the single leading cause of mortality in Western cultures. The development of atherosclerotic lesions is thought to follow the phenotypic modulation of medial smooth muscle cells (SMC) from the contractile to the synthetic state. A variety of signals have been identified that appear to participate in this modulation including oxidative stress, cytokines and interleukins of macrophage origin and endothelial factors (endothelins and NO.). The primacy of serum hypercholesterolemia as a risk factor suggests that the molecule cholesterol may also play a role in atherogenesis. Work performed by our lab has shown that enrichment of the SMC plasma membrane with cholesterol induces alterations in SMC very similar to those seen in atherosclerosis. Moreover, these alterations are reversed by estrogen. We hypothesize that enrichment of the SMC plasma membrane with cholesterol is an important factor contributing to SMC modulation during atherogenesis, and that estrogen's ability to reverse this effect contributes to its atheroprotective actions. We will test this hypothesis in 2 aims. Aim l will determine whether cholesterol's ability to alter the SMC membrane bilayer structure, as a single, isolated and independent variable contributes to the phenotypic and gene expression alterations in SMC during atherogenesis. Aim 2 will determine whether the atheroprotective effects of estrogen are mediated A), directly at the level of the arterial SMC and B), whether the mechanism of estrogen's actions are mediated, in part, by countering cholesterol's effects on the arterial SMC membrane. For these studies,we will employ two preparations of vascular cells: 1. early passage (equal to or <3) rabbit aortic SMC, and 2, early passage (equal to or <3) human aortic and coronary artery SMC. Phenotypic alterations will be followed including cell proliferation and collagen synthesis. NFkappaB activation and the generation of reactive oxygen intermediates will be measured as potential signaling intermediates using appropriate techniques. Alterations in gene expression will be assessed by measuring message and protein levels for 2 genes we have identified to be upregulated in SMC during atherogenesis (hn-RNP-K and prolyl-4-hydroxylase) as well as genes identified by others reflecting the synthetic phenotype in SMC, collagens I and III. Combining these approaches will provide essential insights into the cellular basis for the early defects in human SMC during atherogenesis and how estrogen provides cellular protection in this disease

动脉粥样硬化仍然是西方文化中导致死亡的唯一主要原因。动脉粥样硬化病变的发展被认为遵循内侧平滑肌细胞（SMC）从收缩状态到合成状态的表型调节。已鉴定出多种信号似乎参与了这种调节，包括氧化应激、细胞因子和巨噬细胞来源的白细胞介素以及内皮因子（内皮素和NO）。血清高胆固醇血症作为危险因素的首要地位表明胆固醇分子也可能在动脉粥样硬化形成中发挥作用。我们实验室进行的工作表明，用胆固醇富集 SMC 质膜会引起 SMC 的变化，与动脉粥样硬化中所见的变化非常相似。此外，这些改变可以被雌激素逆转。我们假设 SMC 质膜上胆固醇的富集是动脉粥样硬化形成过程中 SMC 调节的一个重要因素，而雌激素逆转这种效应的能力有助于其动脉粥样硬化保护作用。我们将在两个目标中检验这个假设。目标1将确定胆固醇是否能够改变SMC膜双层结构，作为单一、孤立和独立的变量，在动脉粥样硬化形成过程中导致SMC表型和基因表达的改变。目标 2 将确定雌激素的动脉粥样硬化保护作用是否是在 A) 直接在动脉 SMC 水平上介导的，B) 雌激素的作用机制是否部分是通过对抗胆固醇对动脉 SMC 膜的影响来介导的。对于这些研究，我们将使用两种血管细胞制剂：1.早期传代（等于或<3）兔主动脉SMC，和2，早期传代（等于或<3）人主动脉和冠状动脉SMC。随后将发生表型改变，包括细胞增殖和胶原蛋白合成。 NFkappaB 的激活和活性氧中间体的生成将使用适当的技术作为潜在的信号中间体进行测量。将通过测量我们已确定在动脉粥样硬化形成过程中在 SMC 中上调的 2 个基因（hn-RNP-K 和脯氨酰-4-羟化酶）以及其他人确定的反映 SMC 中合成表型的基因（胶原蛋白 I 和 III）的信息和蛋白质水平来评估基因表达的变化。结合这些方法将为动脉粥样硬化形成过程中人类 SMC 早期缺陷的细胞基础以及雌激素如何在这种疾病中提供细胞保护提供重要的见解