Effect of chronic iron overload on atherosclerosis lesion in apolipoprotein E knockout mice / 中南大学学报(医学版)

OBJECTIVE@#To explore the effect of chronic iron overload on the lesion of atherosclerosis (AS) in apolipoprotein (apo) E knockout mice.@*METHODS@#Twenty-four ApoE knockout mice were randomly divided into ApoE knockout group (0.1 mL saline for 4 weeks) and iron overload group (10 mg iron dextran for 4 weeks). The levels of serum iron (SI), total iron binding capacity, contents of malondialdehyde (MDA), and activity of superoxide dismutase (SOD) in the liver were measured. Iron deposition in the liver and heart was determined, and atherosclerotic plaque areas of the sinus aortae were analyzed.@*RESULTS@#In the iron overload group, the levels of SI increased by 377.86%, the saturation of transferrin increased by 121.98% and the levels of iron in the liver increased by 2,548.15% (P<0.01). The contents of MDA in the liver increased by 32.51% (P<0.01), and the activity of SOD in the liver decreased by 17.2% in the ApoE knockout group (P<0.05). The level of MDA in the liver increased by 411.15%, and the activity of SOD in the liver decreased by 46.84% in the iron overload group (P<0.01). There was a significant deposition of iron in the liver and heart of mice, and the areas of atherosclerotic plaque of sinus aortae increased markedly in the iron overload group.@*CONCLUSION@#Chronic iron overload may promote the development of AS lesion in the ApoE knockout mice, in which the increased oxidative stress and lipid oxidation may involve.

Differentiation of 2 endothelial progenitor cells in vitro and inhibitory effect of asymmetric dimethylarginine on its proliferation / 中南大学学报(医学版)

OBJECTIVE@#To investigate the Methods for culturing two types of endothelial progenitor cells (EPC) from human umbilical cord blood and study their differentiation traits and the depressant effect of asymmetric dimethylarginine (ADMA) on its proliferation.@*METHODS@#Mononuclear cells were isolated from fresh cord blood by 6% hydroxyethyl starch(HES) and density gradient centrifugation.Isolated cells were cultured in the medium supplemented with vascular endothelial growth factors (VEGF) and basic fibroblast growth factors (bFGF). The growth characteristics and biological features of the cells were observed at different time points and identified by morphology,immunofluorescence staining,reverse transcription polymerase chain reaction (RT-PCR), and flow cytometry.Attached cells were incubated with different concentrations of ADMA (1,5, and 10 micromol/L) for 24,48, and 72 hours. Methylthiazoletetrazolium (MTT) assay and quantified colony forming units (CFUs) were used to assess the proliferation of endothelial progenitor cells.@*RESULTS@#The attached cells were divided into 2 types:early EPC and late EPC. Early EPC changed from small sized round cells to spindle shaped cells and late EPC formed a typical cobblestone-like cells. Fluorescence microscopy showed that EPC were positive for both Dil-acLDL uptake and FITC-UEA-I binding.RT-PCR and FACS showed the difference of endothelial cell-specific,gene expression and changed AC133,CD34, and KDR among different times.Incubation of EPC with ADMA dose and time-dependently decreased the number and the proliferation of EPC.@*CONCLUSION@#There are 2 types of EPC from a source of human umbilical cord blood and ADMA may depress the EPC proliferation, providing a basis for further research.

Change of endothelial progenitor cells from peripheral blood in patients with coronary heart diseases before and after percutaneous coronary intervention / 中南大学学报(医学版)

OBJECTIVE@#To investigate the culture of endothelial progenitor cells (EPCs) from peripheral blood in patients with coronary heart diseases (CHD) before and after percutaneous coronary intervention (PCI), and to observe the cells shape and determine the cell number and proliferation activity.@*METHODS@#Ninety-five patients were divided into a CHD group(n=65) and a control group (n=30). The mononuclear cells were isolated from peripheral blood of patients with CHD before, right after and 4 days after PCI by Ficoll-density centrifugation. The isolated cells were cultured in RPMI1640 medium supplemented with VEGF165 and bFGF.EPCs were characterized as adherent cells of double positive for DiL-acLDL uptake and FITC-UEA-I binding by direct fluorescent staining under a fluorescence microscope. The EPCs specific surface mark CD34 and KDR were assessed by fluorescence activated cell sorter analysis. The cell shapes were analysed and the number of colony-forming units(CFU) was counted by phase-contrast microscope.@*RESULTS@#The number of EPCs reduced in patients with CHD before the PCI, but the cell number was significantly increased in patients with CHD after the PCI, and the number reduced in patients with CHD 4 days after the PCI. How-ever, the number of CFUs did not change in patients before and after the PCI.@*CONCLUSION@#PCI can increase endothelial progenitor cells in patients after the PCI; but 4 days after the PCI, this increase will not exist.

Short- and long-term therapeutic effects of combination therapy with perindopril and irbesartan in a rat model of dilated cardiomyopathy / 中南大学学报(医学版)

OBJECTIVE@#To evaluate the short-term, and long-term therapeutic effects of combination therapy with perindopril and irbesartan in a rat model of dilated cardiomyopathy (DCM).@*METHODS@#Sprague-Dawley rats were administered adriamycin intraperitoneally to develop DCM. Grouping of rats: Group A contained normal rats, and Group B contained DCM rats. Both Group A and B were not given drug treatment. Group C and D contained DCM rats, however, Group C was administered perindopril 2mg/(kg x d) while Group D was administered perindopril 1mg/(kg x d) and irbesartan 25mg/(kg x d). Brain natriuretic peptide (BNP) was determined by enzyme linked immunosorbent assay; plasma potassium and creatinine were measured; the pathological lesions of cardiac muscle tissues were evaluated after HE staining; and the survival time of each rat during the intervention was recorded.@*RESULTS@#After the three-week intervention, the plasma concentrations of BNP in Group D were lower than those in Group C (P0.05); pathological lesions of cardiac muscle tissues in both Group C and D were attenuated compared with those in Group B (P0.05). Log-rank test showed that the life span of Group C was shorter than that of Group D (P<0.05); Cox regression analysis showed that both combination therapy and monotherapy with perindopril could prolong the survival time, but the effect of combination therapy was more obvious.@*CONCLUSION@#Combination therapy with perindopril and irbesartan in a rat model of DCM can more effectively improve the cardiac function and long-term prognosis than those monotherapy with perindopril. Both these two treatment plans can attenuate the pathological lesions of cardiac muscle tissues, without elevating the concentrations of plasma potassium and creatinine.

Effect of melatonin on the proliferation, apoptosis, and expression of bcl-2 in oxidized low-density lipoprotein-induced endothelial progenitor cells / 中南大学学报(医学版)

OBJECTIVE@#To explore the effect of melatonin(Mel) on the proliferation, apoptosis and expression of bcl-2 in oxidized low-density lipoprotein(ox-LDL)-induced endothelial progenitor cells (EPC) from human umbilical cord blood in vitro.@*METHODS@#Total mononuclear cells were isolated from human umbilical cord blood in vitro by Ficoll density gradient centrifugation, and the cells were plated on fibronectin-coated culture dishes. After 7 days, the attached cells were divided into 7 groups: a control group (normal cells), 3 ox-LDL groups[the attached cells were incubated with different concentrations of ox-LDL(5,10,and 20mg/L) for 24 hours], and 3 Mel groups[the attached cells were incubated with different concentrations of Mel (0.5,1.0, and 2.0 mmol/L) respectively for 24 hours before incubation with 10 mg/L ox-LDL]. EPC was identified by examining the expression of CD34, vascular endothelial growth factor receptor-2(VEGFR-2) and CD133 under a laser scanning confocal microscope. We used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay to detect the effect of Mel and ox-LDL on the multiplication ability of EPC. Flow cytometry was used to detect the apoptosis. The expressions of Bcl-2 mRNA and protein were detected respectively by RT-PCR and immunohistochemistry technology.@*RESULTS@#After being exposed to the ox-LDL, the proliferation of EPC in the 3 ox-LDL groups was lower, and the apoptosis rate was higher than that in the control group in a dose-dependent manner (P<0.01); Mel was added at different concentrations before the ox-LDL incubation, and the cells in the 3 Mel groups showed higher proliferation and lower apoptosis rate than those of the 3 ox-LDL groups (P<0.01). Expression of Bcl-2 mRNA and protein of EPC in the 3 Mel groups was higher than that in the 3 ox-LDL groups (P<0.01).@*CONCLUSION@#Ox-LDL can inhibit the proliferation of EPC and promote the apoptosis of the cells by down-regulating the bcl-2 expression. Mel can inhibit these effects of ox-LDL.

Effects of fenofibrate on the proliferation and apoptosis and nitric oxide synthase expression of cultured human umbilical vein endothelial cells induced by lysophosphatidylcholine / 中南大学学报(医学版)

OBJECTIVE@#To investigate the effects of fenofibrate on the proliferation and apoptosis and endothelial nitric oxide synthase (eNOS) mRNA expression of cultured human umbilical vein endothelial cells (HUVECs) induced by lysophosphatidylcholine (LPC).@*METHODS@#HUVECs were cultured in vitro. The study was designated to 5 groups according to fenofibrate concentration: control group, LPC group, LPC + low-concentration fenofibrate (10 micromol/L), LPC + middle-concentration fenofibrate (50 micromol/L), and LPC + high-concentration fenofibrate (100 micromol/L). The study was designated to 6 groups according to the intervention time: control group, LPC group, LPC + fenofibrate (50 micromol/L) 6 h, LPC + fenofibrate 12 h, LPC + fenofibrate 24 h, and LPC + fenofibrate 48 h. The proliferation and apoptosis of HUVECs were evaluated by MTT assay, flow cytometry and fluorescence microscopy, respectively. eNOS mRNA were assayed by real time-PCR.@*RESULTS@#Compared with the control group, LPC could inhibit the proliferation and induce apoptosis, and downregulate eNOS mRNA expression and decrease NO production of HUVECs. Fenofibrate could increase the proliferation and decrease the apoptosis, and up-regulate eNOS mRNA expression and enhance NO production in HUVECs.@*CONCLUSION@#Fenofibrate could improve the proliferation and inhibit the apoptosis, and up-regulate eNOS mRNA expression of HUVECs induced by LPC, which may be responsible for fenofibrate to prevent and treat atherosclerosis.

Relevant factors of microalbuminuria in aged patients with essential hypertension / 中南大学学报(医学版)

OBJECTIVE@#To investigate the relationship between microalbuminuria and endothelial-dependent relaxing function and atherosclerosis of common carotid artery (CCA) in aged patients with essential hypertension (EH).@*METHODS@#Sixty-four aged EH patients were recruited. According to the albumin excretion rate (AER) in the urine measured by immunoturbidimetry, patients were divided into 2 groups: normoalbuminuria group (NAU group) and microalbuminuria group (MAU group). Thirty aged persons without EH were served as the control group. The endothelium-dependent relaxing function of blood vessels, intima-media thickness (IMT) and the plaque of CCA were measured by color Doppler ultrasound.@*RESULTS@#The flow-mediated dilation in the MAU group [(4.98+/-1.35)%] and that in the NAU group [(6.31+/-1.14)%] were significantly lower than that in the control group [(9.09+/-1.83)%, P<0.05, respectively], especially lower in the MAU group. The IMT of CCA in the MAU group [(0.97+/-0.19)mm] and that in the NAU group [(0.86+/-0.10)mm] were significantly thicker than that in the control group [(0.78+/-0.13)mm] (P<0.05, respectively), especially thicker in the MAU group. The analysis of multiple stepwise regression showed that the microalbuminuria was successively related to EDF, the IMT of CCA, the plaque index of CCA, systolic blood pressure, etc.@*CONCLUSION@#EDF is impaired, and there is the atherosclerosis of CCA in aged patients with EH. Microalbuminuria correlates with the decrease of endothelium-dependent relaxing function and the IMT of CCA in aged patients with EH.

Effects of advanced glycation end products on the activity of NF-kappaB and the expression of fibronectin mRNA in the endothelial cells in aged rats / 中南大学学报(医学版)

OBJECTIVE@#To explore the effects of advanced glycation end products (AGEs) on the activity of NF-kappaB and fibronectin (Fn) synthesis in the endothelial cells in aged rats.@*METHODS@#Endothelial cells were cultured in M199 from the aorta of 24 month old rats and divided into 3 groups: Group A (5 mmol/L glucose) as controls, Group B (25 mg/L AGEs for 48 h), and Group C (50 mg/L AGEs for 48 h). The activity of NF-kappaB was evaluated by immunofluorescence and the expression of Fn mRNA was measured by reverse transcription-polymerase chain reaction (RT-PCR).@*RESULTS@#Compared with the controls, AGEs induced the activity of NF-kappaB and increased the Fn mRNA expression in a concentration-dependent manner (P<0.05).@*CONCLUSION@#The activity of NF-kappaB and up-regulated expression of Fn mRNA induced by AGEs may contribute to chronic complications of diabetes.