Effects of high-density lipoprotein on the cholesterol efflux from endothelial cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effects of high-density lipoprotein (HDL) and oxidized high-density lipoprotein (ox-HDL) on the expression of ATP-binding cassette transporter A1 (ABCAl) and cholesterol efflux in human umbilical vein endothelial cells (HUVECs).</p><p><b>METHODS</b>In vitro cultured HUVECs were incubated in the presence of 100 microg/ml HDL or 100 microg/ml ox-HDL for 24 h, using PBS as the negative control. ABCA1 mRNA level and cholesterol efflux rate were determined using RT-PCR and a liquid scintillator, respectively.</p><p><b>RESULTS</b>HDL and ox-HDL significantly elevated the level of ABCA1 mRNA by 58% and 23% relative to the control level, respectively (P<0.05). The cholesterol efflux rate in ox-HDL group was significantly lower than that in HDL group (P<0.01).</p><p><b>CONCLUSION</b>HDL increases ABCAl expression and cholesterol efflux in HUVECs. Oxidative modification of HDL decrease cholesterol efflux by inhibiting the expression of ABCAl, suggesting a possible mechanism of ox-HDL in the pathogenesis of atherosclerosis.</p>

Evaluation of a rabbit model of abdominal aorta atherosclerosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the methods for non-invasive evaluation of a rabbit model of aorta atherosclerosis model.</p><p><b>METHODS</b>Sixteen male New Zealand rabbits (n=16) were randomized into the experimental group and control group and fed with high-cholesterol diet and normal diet after balloon injury in the abdominal aorta, respectively. Eight weeks later, pathological examination, angiography and surface ultrasonography were carried out to evaluate the plaques in the aorta.</p><p><b>RESULTS</b>After feeding with high-cholesterol diet for 8 weeks, the weight, total cholesterol (TC), triglycerides (TG) and low-density lipoprotein (LDL) were significantly increased in the rabbits (P<0.001), and atherosclerosis in the abdominal aorta was directly observed using angiography and surface ultrasonography. The rate of vasoconstriction showed significant difference between the experimental group and control group (t=5.921, P=0.000). In the experimental rabbits, the vasoconstriction increased obviously after drug stimulation with high lumen eccentricity index. A significant positive correlation was noted between the lumen eccentricity index and the rate of vasoconstriction (r=0.983, P=0.000).</p><p><b>CONCLUSION</b>A rabbit model of abdominal aorta atherosclerosis can be established rapidly by balloon injury and high-cholesterol diet. The aortic wall thickness, lumen diameter and lumen eccentricity index determined by surface ultrasonography can be used to evaluate the validity of the model establishment and the nature of the plaque.</p>

Oxidized low-density lipoprotein enhances the expressions of SREBP-2 and HMGCR mRNA in macrophages derived from the monocytes of patients with acute coronary syndrome / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of oxidized low-density lipoprotein (ox-LDL) on the expressions of sterol regulatory element binding protein-2 (SREBP-2) and hydroxymethylglutaryl CoA reductase (HMGCR) in the macrophages derived from monocytes of patients with acute coronary syndrome (ACS).</p><p><b>METHODS</b>LDL was oxidized by Cu2+ to prepare ox-LDL, and peripheral monocytes were isolated by density gradient centrifugation from patients with ACS diagnosed by coronary arteriography. Macrophages derived from the monocytes after phorbol myristate acetate (PMA) stimulation were treated with ox-LDL at the concentrations of 0, 20, 40, and 100 ng/ml, and the changes in the expressions of SREBP-2 and HMGCR were detected by real-time RT-PCR.</p><p><b>RESULTS</b>Compared with the control cells, the macrophages treated with ox-LDL showed significantly increased expressions of SREBP-2 and HMGCR mRNA (P<0.05). In cells treated with ox-LDL, the expressions of SREBP-2 and HMGCR mRNA differed significantly with the dose administered (P<0.05).</p><p><b>CONCLUSION</b>Within a defined dose range, ox-LDL can dose-dependently enhance the expressions of SREBP-2 and HMGCR mRNA in macrophages from patients with ACS.</p>

Effect of Astragalus polysaccharides on the phenotype and functions of human dendritic cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the effect of astragalus polysaccharides (APS) in inducing phenotypic and functional changes of human dendritic cells (DCs) in vitro.</p><p><b>METHODS</b>Human dendritic cells were induced from the peripheral blood monocytes in vitro by the application of tumor necrosis factor-alpha (TNF-alpha), interleukin-4 (IL-4) and GM-CSF, and cultured in the presence of APS at different concentrations (50, 100, and 200 mg/L). The morphological changes of the DCs were identified by optical microscope or scanning electron microscope. The phenotypic alterations of the cells were analyzed by flow cytometry.</p><p><b>RESULTS</b>The DCs cultured for 24 h in the presence of LPS and APS at 50 and 100 mg/L showed suspended growth in the culture medium and underwent morphological changes from spherical cells to irregular cells, with rough cell surface and cell processes of different morphologies. APS-treated DCs had the most typical dendritic structures and highly expressed the phenotypic markers of DCs (CD86 and HLA-DR), but with down-regulated CD14 expression as shown by flow cytometry.</p><p><b>CONCLUSION</b>Both APS and the cytokines can induce the maturation of DCs derived from peripheral blood monocytes.</p>

Classification and functional study of peripheral blood dendritic cells in patients with coronary artery disease with different atherosclerotic plaques / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the quantitative and functional changes of peripheral blood dendritic cells (DCs) and their subsets in the leukocyte population in patients with coronary artery disease (CHD) with different coronary artery plaques and explore the relation between DCs and coronary plaque development.</p><p><b>METHODS</b>Thirty CHD patients were divided into SAP (10 cases), UAP (10 cases) and ACS (10 cases) groups, with another 10 patients having negative result in coronary angiography as the control group. Intravascular ultrasound (IVUS) was performed to identify the nature of the plaques. The percentage and absolute number of peripheral blood DCs and DC subsets were measured by flow cytometry. The functional status of the DCs was analyzed by enzyme-linked immunosorbent assay (ELISA) and flow cytometry.</p><p><b>RESULTS</b>In the SAP group, IVUS found stable plaques in 8 cases and unstable plaques in 2 cases; in UAP group, 7 patients had unstable plaques, 2 had stable plaques, and 1 had plaque rupture. Plaque rupture, unstable plaques and stable plaques were found in 6, 3 and 1 patients in ACS group, respectively. In comparison with patients with stable plaques, those with unstable plaques had significantly increased percentages and number of DCs, mDCs and mDC1 (P<0.05), while the mDC2s and pDCs showed no obvious difference between them (P>0.05). The percentages and number of DCs, mDCs, mDC1s and pDCs were significantly decreased in patients with ruptured plaques (P<0.05). In peripheral blood monouclear cells cultured for 7 days, the CD83 expression was significantly higher in unstable and rupture plaque groups than in stable plaque group, and no significant difference was found between stable plaque group and the control group (P>0.05). In unstable and rupture plaque groups, co-culture with 2x10(5)/ml DCs evoked strong proliferation of the T cells in comparison with the stable plaque group, but no difference was found between the stable plaque and the control groups (P>0.05). Significantly higher levels of interleukin-2 and interferon-alpha were detected in the supernatant of the mixed lymphocyte reaction in unstable and ruptured plaque groups than in stable plaque and control groups, without obvious difference between the latter two groups.</p><p><b>CONCLUSION</b>The percentage and absolute number of peripheral blood DCs and their functional status suggest the alterations of the coronary artery plaques in CHD patients.</p>

Effects of high-density lipoprotein 1 on the formation of foam cells from human monocyte-derived macrophages / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate effects of serum HDL(1) on the formation of foam cells from human peripheral blood monocyte-derived macrophages.</p><p><b>METHODS</b>Sectie density polyacrylamide gel electrophoresis (sd-PAGE) was applied for isolation and preparation of HDL(1) simultaneously. Monocytes were isolated from human peripheral blood by Ficoll-Hypaque density gradient centrifugation and plastic adsorptive process. The isolated monocytes were stimulated by phorbol 12-myristate 13-acetate (PMA) at a concentration of 50 nmol/L for 48 h and transferred to macrophages. The monocyte-derived macrophages were then coincubated with 80 mg/L ox-LDL and HDL(1) (0, 0.1, 1.0 and 10.0 mg/L) for 6, 12 and 24 h, respectively. The formation of foam cells was identified by transmission electron microscope (TEM), total cholesterol (TC), free cholesterol (FC) and protein (Pro) in cultured cells were quantitatively analyzed by high performance chromatography (HPLC) and modified lowry protein assay, respectively.</p><p><b>RESULTS</b>HDL(1) isolated from human serum by sd-PAGE could significantly decrease TC/Pro ratio in foam cells in a concentration-dependent (0 mg/L: 36.9 +/- 1.1, 10.0 mg/L: 6.2 +/- 0.4, P < 0.01) and time-dependent (10.0 mg/L HDL(1) 6 h: 16.9 +/- 0.9, 24 h: 6.4 +/- 0.6, P < 0.01) manner.</p><p><b>CONCLUSION</b>HDL(1) is capable of inhibiting and attenuating the formation of foam cells by decreasing cellular TC, therefore, might play an important role in attenuating atherosclerosis.</p>

Peripheral dendritic cell subpopulation changes in patients with coronary artery disease / 中华心血管病杂志

<p><b>OBJECTIVE</b>To compare the peripheral dendritic cell subpopulation changes in patients with or without coronary artery disease.</p><p><b>METHODS</b>A total of 60 patients with angiographic documented coronary artery disease (CAD) were recruited in this study, including 20 cases with acute myocardial infarction (AMI group), 20 cases with unstable angina(UA group) and 20 patients with stable angina (SA group). Eleven patients with chest pain and without coronary stenosis served as chest pain control (CPS group). Ten cases without heart diseases served as normal control (Normal control group). Numbers of peripheral myeloid dendritic cell (mDC) and plasmacytoid dendritic cell (pDC) precursors were determined by FACS.</p><p><b>RESULT</b>The proportions of mDC precursors were significantly lower in UA group and AMI group (4.7% +/- 2.6%, 5.0% +/- 2.7%) than that in SA, CPS and control groups (11.0% +/- 6.4%, 12.0% +/- 3.9%, 12.3% +/- 3.3%, respectively, all P < 0.001). pDC numbers were similar among groups.</p><p><b>CONCLUSION</b>Reduced circulating mDC subsets in patients with unstable angina and AMI might suggest enhanced mDC recruitment to vulnerable plaques in these patients.</p>

Association of dendritic cell distribution with intima hyperplasia in rats with diabetes mellitus / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the association of dendritic cell distribution in the peripheral blood, spleen and arterial wall with intimal hyperplasia in rats with diabetes mellitus.</p><p><b>METHODS</b>Diabetes mellitus was induced in rats by intraperitoneal injection of streptozotocin and high-fat feeding for 8 weeks. Peripheral blood, arterial wall and the spleen were collected from the rats to prepare cell suspensions, in which the proportions of dendritic cells and T cells were determined by flow cytometry.</p><p><b>RESULTS</b>The tunica intimal hyperplasia was more obvious in diabetic rats with or without high-fat feeding as compared with that of the control rats (P<0.05), and their dendritic cells decreased significantly in the peripheral blood (P<0.05) but increased in the arterial wall. The percentage of T cells was also increased in the peripheral blood and arterial wall of the diabetic rats.</p><p><b>CONCLUSION</b>Changes in the distribution of dendritic cells and T cells are closely associated with intimal hyperplasia in diabetic rats, suggesting the involvement of dendritic cells and T cells in the formation of atherosclerosis.</p>

Effect of rosiglitazone on tumor necrosis factor-alpha-induced nuclear factor-kappaB and coupling factor 6 expressions in human umbilical vein endothelial cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of rosiglitazone on the expression of nuclear factor-kappaB (NF-kappaB) and coupling factor 6 (CF6) induced by tumor necrosis factor-alpha (TNF-alpha) in cultured human umbilical vein endothelial cells (HUVEC).</p><p><b>METHODS</b>Cultured HUVEC of passage 3-5 were stimulated with TNF-alpha and then cultured in the presence of rosiglitazone. The expression of CF6 and NF-kappaB subunit p65 were evaluated by immunocytochemistical method.</p><p><b>RESULTS</b>Pretreatment of HUVECs with rosiglitazone inhibited TNF-alpha-induced expression of CF6 in a dose-dependent manner. The activation of CF6 stimulated by TNF-alpha was suppressed by ROS in a dose-dependent manner.</p><p><b>CONCLUSION</b>TNF-alpha-induced enhancement of the gene expression and release of CF6 is mediated by activation of NF-kappaB signaling pathway. ROS can inhibit the activation of IKK, block NF-kappaB signaling pathway and inhibit the expression of CF6, which may be the mechanism underlying the action of TZDs on hypertension.</p>

Changes of CD4+CD28- T cell and CD4+CD25+ regulatory T cell subsets in patients with coronary heart disease / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes of CD4(+)CD28(-) T cell and CD4(+)CD25(+) regulatory T cell (Treg) subsets in patients with coronary artery disease (CAD).</p><p><b>METHODS</b>Twenty-eight patients with angiographically established CAD were recruited in this study, including 16 with unstable angina (UA group) and 12 with stable angina (SA group). Eleven patients with chest pain syndrome served as the control group. The proportions of peripheral CD4(+)CD28(-) T cells and CD4(+)CD25(+) Treg subsets were determined with fluorescence-activated cell sorting (FACS).</p><p><b>RESULTS</b>The proportions of CD4(+)CD25(+) Treg were significantly lower in UA group (6.55-/+2.45%) than in SA (14.01-/+4.92%) and control groups (13.55-/+3.87%). The proportions of CD4(+)CD28(-) T cells were significantly higher in UA group (10.55-/+4.76%) than in SA (2.64-/+1.33%) and control (2.75-/+1.55%) groups.</p><p><b>CONCLUSION</b>Alterations of circulating T-lymphocyte subsets occur in patients with UA. The changes of Treg and CD4(+)CD28(-) T cells may lead to breakdown of peripheral autoimmune tolerance and play an important role in the development and progression of CHD.</p>

Atorvastatin Inhibits The Development of Macrophages to Foam Cells / 中华高血压杂志

Objective To investigate effects of atorvastatin on the development from macrophages (HMDM) to foam cells.Methods Monocytes were isolated from human peripheral blood by Ficoll-Hypaque density gradient centrifugation and plastic adsorptive process.The isolated cells were stimulated by phorbol 12-myristate 13-acetate (PMA) (50 nmol/L) for 48 h and transformed to macrophages.Macrophages were co-incubated with 80 mg/L ox- idized low density lipoprotein (ox-LDL) and atorvastatin (0-100 ?mol/L),respectively for 0,6,12 and 24 h. Total cholesterol (TC),free cholesterol (FC) and protein (Pro) in cultured cells were quantitatively analyzed by high performance chromatography (HPLC) analysis and modified Lowry protein assay.Results When macropha- ges were incubated with 80 mg/L ox-LDL,the ratio of TC/Pro was greater than 20,and large amount of lipid drop- lets were displayed indicating the formation of foam cells.Atorvastatin decreased TC/Pro ratio in foam cells in a concentration and time dependent manner (0-100 ?mol/L)(P

Effects of simvastatin on DNA synthesis in rat cardiac fibroblasts / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of simvastatin (Sim) and the interference by mevalonate (MVA) against its effect on DNA synthesis in rat cardiac fibroblasts (CFs).</p><p><b>METHODS</b>CFs were isolated from neonatal SD rats by trypsin digestion and growth-arrested CFs were stimulated with Sim and/or MVA at varied concentrations for different time lengths, and the DNA synthesis in the cells was measured by (3)H-thymidine ((3)H-TdR) incorporation assay.</p><p><b>RESULTS</b>Sim decreased (3)H-TdR incorporation in the CFs in a concentration-dependent manner, and (3)H-TdR incorporation was significantly lower in cells treated with 1 x 10(-6) and 1 x 10(-5) mol/L Sim (1,175+/-202.66 and 771+/-164.86 cpm/2000 cells, respectively) than in the control cells (1,608+/-204.32 cpm/2000 cells, P<0.01). As the treatment time with 1 x 10(-5) mol/L Sim prolonged (for 6, 12, 18, 24, 36, 42, and 48 h), (3)H-TdR incorporation in CFs decreased gradually, showing an obvious inverse correlation with the treatment time (r=-919, P<0.01). (3)H-TdR incorporation in cells treated with 1 x 10(-6) to 1 x 10(-3) mol/L MVA and 1 x 10(-5) mol/L Sim rose steadily as MVA concentration increased. A significant difference in the incorporation was found between cells treated with both 1 x 10(-4)/1 x 10(-3) mol/L MVA and 1 x 10(-5) mol/L Sim (1,612+/-308.57 and 1,995+/-353.83 cpm/2000 cells, respectively) and the cells with 1 x 10(-5) mol/L Sim treatment alone (P<0.01); difference was also noted between cells treated with 1 x 10(-5) mol/L MVA and the control cells (P<0.05), but treatment with 1 x 10(-6) mol/L MVA did not produce much difference in comparison with the control cells (P>0.05) With the increase of treatment time (for 6, 12, 18, 24, 36, 42, 48 h), 1 x 10(-3) mol/L MVA caused steady increase in (3)H-TdR incorporation in the CFs, showing a significant positive correlation with the treatment time (r=0.968, P<0.01).</p><p><b>CONCLUSION</b>Sim can decrease DNA synthesis in rat CFs and postpone the occurrence of myocardial fibrosis, which can be reversed by MVA.</p>