Mechanism of Vascular Remodeling in Hyperhomocysteinemia

高同型半胱氨酸血症血管重塑机制

• 批准号: 6522232
• 负责人: Suresh C. Tyagi
• 金额: $ 25.9万
• 依托单位: UNIVERSITY OF MISSISSIPPI MED CTR
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2003-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6522232
• 关键词: affinity chromatography; antihyperlipoproteinemic agent; atherosclerotic plaque; cardiovascular injury; clofibrate; elastin; homocystinuria; laboratory mouse; metalloendopeptidases; nitric oxide; peroxisome proliferator activated receptor; receptor binding; receptor expression; tyrosine; vasomotion; western blottings

DESCRIPTION (provided by the applicant): The long-term objective of this project is to further the understanding of contribution of homocysteine in vascular disease. Previous studies have indicated a decrease in the bioavailability of endothelial nitric oxide and an increase in the concentration of nitrotyrosine in the aortic wall associated with hyperhomocysteinemia. The plasma levels of homocysteine have shown to be inversely related to peroxisome proliferator activated receptor (PPAR), a nuclear receptor, which ameliorates vascular dysfunction. The central hypothesis of this proposal is that increased levels of homocysteine suppress the activity of PPAR by increasing the generation of nitrotyrosine and metalloproteinase activity, and decreasing the endothelial nitric oxide concentration. The central hypothesis will be addressed by the following four specific aims: 1) To determine whether the homocysteine binds to PPAR, the competitive binding of homocysteine and agonist (fibrate) to PPAR will be measured using homocysteine-cellulose affinity chromatography and aortic nuclear extracts. Bound PPAR will be eluted with fibrate and characterized by antibody to PPAR. 2) To determine whether the increase in PPAR expression decreases nitrotyrosine levels and increases endothelial nitric oxide concentration in a murine model of hyperhomocysteinemia, the concentrations of PPAR and nitrotyrosine in the aortas of hyperhomocysteinemic mice treated with and without fibrate will be measured by Western blot analysis. The levels of nitric oxide will be measured by estimating the total nitrate/nitrite concentration. 3) To determine whether the increase in PPAR decreases the levels of metalloproteinase and elastinolysis, the matrix metalloproteinase activity will be measured using specific substrate gel zymography, and the elastinolysis by identifying elastin fragments using anti-elastin antibody. 4) To determine whether an increase in PPAR expression reverses the homocysteine-mediated vascular dysfunction, the aortic contractile function will be measured. The proposed studies will elucidate the molecular, cellular and extracellular mechanism by which homocysteine promotes arterial lesions and should provide new insights to therapeutic ramifications for vessel wall disease.

描述（由申请人提供）：该项目的长期目标是进一步理解同型半胱氨酸在血管疾病中的贡献。先前的研究表明，内皮一氧化氮的生物利用度有所下降，并在与高脑抑制性抑制性的主动脉壁中的硝基酪氨酸浓度升高。同型半胱氨酸的血浆水平已证明与过氧化物酶体增殖物激活受体（PPAR）是核受体，可改善血管功能障碍。该提议的中心假设是，同型半胱氨酸的水平增加通过增加亚硝基酪氨酸和金属蛋白酶活性并降低内皮一氧化氮浓度来抑制PPAR的活性。以下四个特定目的将解决中心假设：1）确定同型半胱氨酸是否与PPAR结合，同型半胱氨酸和激动剂（纤维化）与PPAR的竞争性结合将使用同半胱氨酸 - 固醇亲和力色谱和主动脉核提取物测量。绑定的PPAR将用纤维化洗脱，并以抗PPAR抗体为特征。 2）确定PPAR表达的增加是否降低了硝基酪氨酸水平并在高脑结合结构血症的鼠模型中增加内皮氧化物氧化物的浓度，请通过蛋白质分析测量未经纤维化和未经纤维化的纤维化分析，在无纤维纤维治疗的超体质体积小鼠主动脉中的PPAR和硝基酪氨酸浓度。一氧化氮水平将通过估计硝酸盐/亚硝酸盐浓度来测量。 3）为了确定PPAR的增加是否降低了金属蛋白酶酶和弹性溶解的水平，将使用特定的底物凝胶酶学测量基质金属蛋白酶活性，并通过使用抗 - 雌激素抗体鉴定弹性蛋白片段来测量弹性蛋白溶解。 4）为了确定PPAR表达的增加是否会逆转同型半胱氨酸介导的血管功能障碍，将测量主动脉收缩功能。拟议的研究将阐明同型半胱氨酸促进动脉病变的分子，细胞和细胞外机制，并应为血管壁疾病的治疗后果提供新的见解。