碩士 / 國立臺灣大學 / 臨床醫學研究所 / 90 / Summary
Background
Atherosclerosis is the leading cause of death and disability in the developed world. Coronary artery disease , mostly derived from atherosclerosis, causes angina pectoris, acute myocardial infarction, arrythmias, heart failure, or sudden death. Percutaneous transluminal coronary angioplasty is the major treatment of coronary artery disease. Over 10,000 procedures annually were performed in Taiwan. The Achilles heel of PTCA is the relatively high restenosis rate (around 40%). Restenosis is a complex process associated with elastic recoil of the vessel wall, remodeling of the arterial wall, proliferation of fibrous tissue and smooth muscles of the intima, excess formation of extracellular matrix, residual plaque within the artery, and thrombus formation. Clinical predictors of restenosis include diabetes mellitus, unstable angina, and angiographic predictors. The changes of biological factors after coronary angioplasty are not well known. Changing plasma level of C-reactive protein, serum amyloid A, hemostatic factors endothelin-1, heat shock protein 65, N- terminal proatrial natriuretic peptide, interleukin 6, and macrophage-colony stimulating factors were reported. Some of them are associated with coronary restenosis. However, these findings may explain only parts of human body reaction to coronary balloon angioplasty.
Proteomics is the study of the entire protein complement (functional output) of a genome by means of protein separation, identification, and bioinformatics. No one has used this method to analyze the proteins change after coronary balloon angioplasty.
Our study is designed to analyze acute phase protein change after PTCA by means of proteomics-based approach, which may characterize overall changes in protein expression before and after percutaneous transluminal coronary angioplasty. Understanding the protein change may help us understand the reaction of our body to PTCA, the potential biologic risk factors for post-angioplasty coronary restenosis.
Methods
Thirty patients receiving percutaneous transluminal coronary angioplasty with stenting were enrolled. Blood was sampled from the patients before, immediately after, one day after, and 1 week (not all patients) after successful coronary balloon angioplasty. The patients received follow-up at OPD. If the patients had symptoms of angina pectoris or exercise intolerance, he would receive stress test (treadmill test or Thallium-201 myocardial perfusion scan). If the patients have positive results of stress test or if they have acute myocardial infarction/ unstable angina, they would receive coronary angiography to see if coronary restenosis occurs.
Two-dimensional gel electrophoresis was performed: (1) Immobilized pH gradient (IPG) as first dimension. (2) SDS-PAGE as second dimension. (3) Silver stain and scanning. Gel images were analyzed with Melanie software to compare multiple gels of the samples from the same patients before and after coronary angioplasty. Comprehensive proteome databases on the internet (ExPaSy Molecular Biology Server) are linked. Proteins of significant change were identified on the basis of isoelectric points and molecular size determined from the two-dimmensional gels. Proteins of significant change were correlated to the possible reaction of our body to coronary angioplasty.
Results
Blood samples from 7 patients before and after coronary angioplasty were analyzed by two dimensional gel electrophoresis and further protein identification. About 45 significant protein spots change were found. The possible proteins of significant change are haptoglobin, complement C4, transthyretin, immunoglobin light chain and heavy chain mu, and plasma retinol binding protein.
Haptoglobin, an acute phase protein, is synthesized by liver. Three polymorphism-- Hp(1-1), Hp(2-1), Hp(2-2) were found. Possession of a particular phenotype has been associated with lipid metabolism and a variety of common disorders (e.g. cardiovascular disease, autoimmune disorders, malignancy).Complement C4 was rarely studied in association with cardiovascular disease. Content of C3 and C4 fractions was reported to decrease in blood of patients with AMI within 1st day of disease.ransthyretin, plasma retinol binding protein, immunoglobulin heavy chain and light chain to cardiovascular diseases so far is not clear. We believe that most of the proteins of significant change are relieved from liver or other tissue, which are stimulated by cytokines from local vascular tissue.
The major limitation of this study is its small sample size, and inability of two dimensional gel electrophoresis to detect cytokines level change. The future work is to increase the sample size, to analyze unidentified spots of interest by mass spectrometry and sequencing, to quantify the change of haptoglobin, complement C4, prealbumin before and after coronary angioplasty, and to correlate the plasma protein change with clinical outcomes (e.g. restenosis).
| Identifer | oai:union.ndltd.org:TW/090NTU01521023 |
| Date | January 2002 |
| Creators | Liu Yuan-Hong, 劉芫宏 |
| Contributors | 江福田 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 35 |
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