| Background Cardiovascular disease caused by atherosclerosis is a common disease damaging people s health. It's an important topic in medicine to study the mechanism of atherosclerosis and its prevention and therapy. Ross thought atherosclerosis is a chronic hyperplasia inflammatory caused by injury factors. Oxidized LDL is one of important injury factors which mediated the damage to vascular wall through its receptor. LOX-1 is a lectin-like oxidized LDL receptor found in 1997 and type-II membrane protein belonging to the C-type lectin family molecules. Someone thought Ox-LDL may induce expression of LOX-1 mRNA, but the function of a receptor is decided by the expression of protein. There is no report in China about LOX-1 protein expression and its cell location and whether LOX-1 mediates the damage induced by oxidized LDL is still unknown. Endothelial cells are active metabolical and endocrine organ with many functions. To clarify the issue, endothelial cells are used. A series of large-scale prevention trails of coronary artery disease established that statinstreatment leads to a significant reduction in dislipidaemias and coronary artery events. The benefits of lowing-lipid are unarguable. The non-lipid effects of statins such as anti-infammotory, stabilizing plaque, restraining proliferation of smooth muscle etc are increasingly recognized. The present study is to examine the effect of atovastatin on LOX-1 mRNA and protein, MCP-1 mRNA, ICAM-1 mRNA and secretion of NO induced by oxidized LDL in order to understand the non-lowing lipid of atovastatin.First part The expression of LOX-1 mRNA and protein induced by oxidized LDL and location in cells.Methods LDL was isolated from the blood by one-step discontinuous density gradient ultracentrifugation. Oxidation was carried out with Cu2+. Human umbilical vein endothelial cells were incubated with different concentration (20, 40, 60, 80 mg/L) of oxidized LDL for 24 h or with 40 mg/L oxidized LDL for different periods (0, 3, 6, 12, 24 h). LOX-1 mRNA was detected by quantitative reverse transcription polymerase chain reaction and LOX-1 protein was examined by cell-based enzyme linked immunosorbant assay. The location of LOX-1 protein in cells was observed by immunohistochemistry. The protein of p38 MAPK was detected by Western blotting.Results 1. The levels of mRNA and protein of LOX-1 increased after cells were incubated with 20 mg/L oxidized LDL (P<0.01) and reached the maximum at 40 mg/L oxidized LDL, and then declined. Otherwise in the same concentration of 40 mg/L oxidized LDL the expression of both mRNA and protein of LOX-1 were progressively increased with the incubation time from Oh to 24h (P<0.01). 2. As immunohistochemisty showed, there were brown granules in control and oxidized LDL group. Brown granules located at the cell plasma and membrane, and even at dendritic structure. There was significant difference between oxidized LDL group and the control group (P<0.01, n=10). 3. Phospho-p38 MAPK protein was significantly higher in oxidized LDL group than in control and polyinosinic acid group (i*<0.01) , but there was no difference in non phospho-p38 MAPK protein among three group.Second part LOX-1 mediated the damage induced by oxidized LDL Methods There were three groups: Control and oxidized LDL and polyinosinic acid group. Human umbilical vein endothelial cells in oxidized LDL group were incubated with different concentration (20, 40, 60, 80 mg/L) of oxidized LDL for 24 h or with 40 mg/L oxidized LDL for different periods (0, 3, 6, 12, 24 h). Human umbilical vein endothelial cells in polyinosinic acid group were firstly incubated with polyinosinic acid for 1 h, then with 40 mg/L oxidized LDL for 24 h. Cells morphology was observed with inverted phasecontrast microscope. NO of supernatant was detected by Enzyme-method.ICAM-l and MCP-1 mRNA were detected by quantitative reverse transcription polymerase chain reaction.Results 1. Cells of oxidized LDL group were crude with clear profiles and bright granules in the plasma especially 8...
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