Influences Of Catecholamines On THP-1 Foam Cell Formation

Part ⅠThe cardiovascular system is a target of psychosocial stress associated with exercise-induced myocardial ischemia, increases in blood pressure, heart rate, and arrythmias, development of arteriosclerosis, and death. Recent data have indicated an interplay among hypothalamus, pituitary gland, adrenal medulla, and sympathetic nerve terminals as the neuroendocrine response to stress. Little is known about the mechanisms converting psychosocial stress into cellular dysfunction. Various genes, up-regulated in atherosclerosis but also by psychosocial stress. AIM: To study the influences of catecholamines on foam cell formation and cholesterol efflux in THP-1 macrophage-derived foam cell. To study the effect of catecholamines on TGF-β1, CD36, SR-A I , ABCA1 and Caveolin-1 expression. To investigate the cell signal transduction pathway of catecholamines induce dysfunction of THP-1 macrophage-derived foam cell.METHODS: High performance liquid chromatography (HPLC) anlysis was performed to determine the content of cellular cholesterol. Cholesterol efflux were determined by liquid scintillator. The mRNA levels of TGF-pl, CD36, SR-A I , ABCA1 and Caveolin-1 in the THP-1 macrophage-derived foam cell were determined by reverse transcription polymerase chain reaction (RT-PCR). Levels of TGF-pl in the supernatants of cells were determined by enzyme-linked immunosorbent assay (ELISA). Western-blot analysis were used to dectect protein level of SR-A I and ABCA1.RESULTS: We use the different concentrations of noradrenalin (10 nmol/L~10 umol/L) which incubate with THP-1 macrophage-derived foam cell 24 hour. It is show that after treat with 1 umol/L and 10 umol/L noradrenalin the content ofcellular total cholesterol, free cholesterol and cholesterol ester significant increase in a dose- and time-dependent manner (p<0.05) . But cholesterol efflux that depend on apoA- I appears to a dose-dependent decrease in these cells (p<0.05) . THP-1 macrophage-derived foam cell is treated with 100 nmol/L and 10 umol/L noradrenalin, the mRNA levels of TGF-pl and ABCA1 decrease (pO.Ol -, p<0.05), then that of SR-A I increase (p<0.05) . THP-1 macrophage-derived foam cell is treated with 100 nmol/L, 1 umol/L and 10 umol/L noradrenalin, the mRNA and protein levels of TGF-pl > ABCA1 decrease (p<0.05), then 1 umol/L R 10 nmol/L noradrenalin cause the mRNA and protein levels of SR-A I increase (p<0.05) . But adrenalin and noradrenalin have no significant effect of CD36 and Caveolin-1 gene expression (p>0.05) . To investigate the cell signal transduction pathway of noradrenalin affect on TGF-pi, SR-A I and ABCA1 expression, cells were preincubated for 1 hour in the presence of ai-antagonist prazosin, (^-antagonist Yohimbine and Pi-antagonist Metoprolol, P2-antagonist Butoxamine before stimulation with 1 umol/L noradrenalin incubate. It is result, incubated ai-antagonist prazosin resulted in a significant decrease noradrenalin effect on TGF-pl ^ SR-A I and ABCA1 expression ( p<0.01 ) . The Pi-antagonist metoprolol and the P2-antagonist butoxamine also reduced the noradrenalin affect (p<0.05) . The a 2-antagonist yohimbine had no effect(p>0.05). indicating that ai- and P-adrenergic receptors act in concert to mediate noradrenalin effect on TGF-pi ^ SR-A I and ABCA1 expression in THP-1 macrophage-derived foam cell. CONCLUSION: Stress concentrations of noradrenalin significant decrease cholesterol efflux that depend on apoA- I in cultured THP-1 macrophage-derived foam cell. High concentration of adrenalin and stress concentrations of noradrenalin cause TGF- P 1 and ABCA1 expression be decreased in these cells. Noradrenalin effect on TGF-pi > SR-A I and ABCA1 expression by ai- and P-adrenergic receptors mediated.Part IIStudy on the relationship between subclasses of serum HDLand LPL gene HindHI polymorphism in hyperlipidemiaAIM: To investigate lipoprotein lipase gene Hindlll polymorphism and its relationship with serum lipids and apolipoprotein, serum HDL subclasses in patients with hyperlipidemia.METHODS: Contents of serum HDL subclasses in 152 hyperlipidemic patients and 128 healthy subjects were determined by two-dimensional gel electrophoresis conjunction with immunodetection method. Lipoprotein lipase gene Hindlll polymorphism was assayed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).RESULTS: It has been shown that the relative percentage contents of HDL subclasses with small particle size (prepi-HDL, preP2-HDL, HDL3a) increased significantly, and that of HDL subclasses with large particle size (HDL2a, HDL2b) decreased significantly in hyperlipidemic patients, which suggested that the maturation of HDL could be abnormal in hyperlipidemia. The polymorphism analyse have shown that H+H+ homozygote genotype and allele H+ in hyperlipidemic patients and control groups were both the highest. Hyperlipidemic group's H+H+ genotypes tended to be higher than that in control group. While H+H- and H-H- genotypes were significantly lower(.P value were 0.019 ). And hyperlipidemia groups allele H+ carriers' frequency tended to be higher and H-allelic frequency of was significantly lower than that in control group (P value were 0.042 ). In hyperlipidemia group, the genotype of H+H+ showed higher serum TG, apoBlOO levels, TG/HDL-C ratio, prep 1-HDL, HDL3b and lower HDL2a, HDL2b compared with H-H- (P <0.05). In control group, the genotype of H+H+ had higher serum TG, HDL3c and lower HDL2a compared with H-H-(/> <0.05). CONCLUSION: The change of HDL subclasses distribution profile may be closely related to the pathogenesis of atherosclerosis in Chinese patients withhyperlipidemia and associated with the particle size and mature metablism of HDLin hperdlipidemic patients. And the Hindlll polymorphism at intron 8 of LPL genemaybe associated with the general shift toward smaller size of HDL particle inhyperlipidemia patients.Part mStudy on apoE gene polymorphism and subclasses of serumHDL in type IV hyperlipidemiaAIM: The aim of the study was to investigate apolipoprotein(apo) E polymorphismand its relationship with serum lipids and apolipoprotein, serum HDL subclasses inpatients with type IV hyperlipidemia.METHODS :apoE genotype was assayed by polymerase chain reaction-restrictionfragment length polymorphism (PCR-RFLP). The subclasses of serum HDL in 103patients with type IV hyperlipidemia and 146 normolipidemic subjects weredetermined by two-dimensional gel electrophoresis conjunction withimmunodetection method.RESULTS:apoE3/3 genotypes and allele s3 frequency in type IV hyperlipidemiagroup and the control group were both the highest. In type IV hyperlipidemia group,the genotype of apoE2 had higher serum HDL-C,apoE, HDL2a apoE/aopCHI ratioand lower TG/HDL-C,apoClII, HDL3C levels compared with the genotype of apoE3(P<0.05). In control group, the genotype of apoE2 had higher serum TG, apoE levelsand apoE/aopCHI ratio, but lower HDL3a level compared with the genotype of apoE3(P<0.05).CONCLUSION:Allele e2 of apoE gene was associated with the maturation ofHDL in type IV hyperlipidemia.