Anti-oxidized low-density lipoprotein antibodies in chronic heart failure

Oxidative stress may play a significant role in the pathogenesis of heart failure(HF).Antibodies to oxidized low-density lipoprotein(oxLDL Abs) reflect an immune response to LDL over a prolonged period and may represent long-term oxidative stress in HF.The oxLDL plasma level is a useful predictor of mortality in HF patients,and measurement of the oxLDL Abs level may allow better management of those patients.Antibodies to oxLDL also significantly correlate with the New York Heart Association score.Hypercholesterolemia,smoking,hypertension,and obesity are risk factors for atherosclerotic coronary heart disease(CHD) leading to HF,but these factors account for only onehalf of all cases,and understanding of the pathologic process underlying HF remains incomplete.Nutrients with antioxidant properties can reduce the susceptibility of LDL to oxidation.Antioxidant therapy may be an adjunct to lipid-lowering,angiotensin converting enzyme inhibition and metformin(in diabetes) therapy for the greatest impact on CHD and HF.Observational data suggest a protective effect of antioxidant supple-mentation on the incidence of HD.This review summarizes the data on oxLDL Abs as a predictor of morbidity and mortality in HF patients.

Role of PERK/eIF2α/CHOP Endoplasmic Reticulum Stress Pathway in Oxidized Low-density Lipoprotein Mediated Induction of Endothelial Apoptosis

Objective PERK/elF2/CHOP is a major signaling pathway mediating endoplasmic reticulum （ER） stress related with atherosclerosis. Oxidized LDL （ox-LDL） also induces endothelial apoptosis and plays a vital role in the initiation and progression of atherosclerosis. The present study was conducted to explore the regulatory effect of ox-LDL on PERK/elF2a/CHOP signaling pathway in vascular endothelial cells. Methods The effects of ox-LDL on PERK and p-elF2a protein expression of primary human umbilical vein endothelial cells （HUVECs） were investigated by Western blot analysis. PERK gene silencing and selective elF2a phosphatase inhibitor, salubrinal were used to inhibit the process of ox-LDL induced endothelial cell apoptosis, caspase-3 activity, and CHOP mRNA level. Results Ox-LDL treatment significantly increased the expression of PERK, PERK-mediated inactivation of elF2a phosphorylation, and the expression of CHOP, as well as the caspase-3 activity and apoptosis. The effects of ox-LDL were markedly decreased by knocking down PERK with stable transduction of lentiviral shRNA or by selective elF2a phosphatase inhibitor, salubrinal. Conclusion This study provides the first evidence that ox-LDL induces apoptosis in vascular endothelial cells mediated largely via the PERK/elF2a/CHOP ER-stress pathway. It adds new insights into the molecular mechanisms underlying the pathogenesis and progression of atherosclerosis.

Oxidized low-density lipoprotein receptor 1:a novel potential therapeutic target for intracerebral hemorrhage

Oxidized low-density lipoprotein receptor 1(OLR1)is upregulated in neurons and participates in hypertension-induced neuronal apoptosis.OLR1 deletion exerts protective effects on cerebral damage induced by hypertensive-induced stroke.Therefore,OLR1 is likely involved in the progress of intracerebral hemorrhage.In this study,we examined the potential role of OLR1 in intracerebral hemorrhage using a rat model.OLR1 small interfering RNA(10μL;50 pmol/μL)was injected into the right basal ganglia to knock down OLR1.Twenty-four hours later,0.5 U collagenase type VII was injected to induce intracerebral hemorrhage.We found that knockdown of OLR1 attenuated neurological behavior impairment in rats with intracerebral hemorrhage and reduced hematoma,neuron loss,inflammatory reaction,and oxidative stress in rat brain tissue.We also found that silencing of OLR1 suppressed ferroptosis induced by intracerebral hemorrhage and the p38 signaling pathway.Therefore,silencing OLR1 exhibits protective effects against secondary injury of intracerebral hemorrhage.These findings suggest that OLR1 may be a novel potential therapeutic target for intracerebral hemorrhage.

A modified laser-induced choroidal neovascularization animal model with intravitreal oxidized low-density lipoprotein

AIM: To investigate whether intravitreal injection of oxidized low-density lipoprotein(OxLDL) can promote laserinduced choroidal neovascularization(CNV) formation in mice and the mechanism involved, thereby to develop a better animal model.METHODS: C57BL6/J mice were randomized into three groups. Immediately after CNV induction with 532 nm laser photocoagulation, 1.0 μL of OxLDL [100 μg/m L in phosphate-buffered saline(PBS)] was intravitreally injected, whereas PBS and the same volume low-density lipoprotein(LDL;100 μg/m L in PBS) were injected into the vitreous as controls. Angiogenic and inflammatory cytokines were measured by quantitative real-time polymerase chain reaction(q RT-PCR) and Western blotting(WB) after 5 d, and CNV severity was analyzed by choroid flat mount and immunofluorescence staining after 1wk. In vitro, retinal pigment epithelial(RPE) cell line(ARPE19) were treated with OxLDL(LDL as control) for 8 h. Angiogenic and inflammatory cytokine levels were measured. A specific inhibitor of lectin-like oxidized low-density lipoprotein receptor 1(LOX1) was used to evaluate the role of LOX1 in this process.RESULTS: At 7 d after intravitreal injection of 1 μL(100 μg/mL) OxLDL, T15-labeled OxLDL was mainly deposited around the CNV area, and the F4/80-labeled macrophages, the CD31-labeled vascular endothelial cells number and CNV area were increased. Meanwhile, WB and qR T-PCR results showed that vascular endothelial growth factor(VEGF), CC chemokine receptor 2(CCR2), interleukin-6(IL-6), IL-1β, and matrix metalloproteinase 9(MMP9) expressions were increased, which was supported by in vitro experiments in RPE cells. LOX1 inhibitors significantly reduced expressions of inflammatory factors IL-1β and VEGF. CONCLUSION: A modified laser-induced CNV animal model is established with intravitreal injection of 1 μL(100 μg/mL) of OxLDL at 7 d, which at least partially through LOX1. This animal model can be used as a simple model for studying the role of OxLDL in age-related macular degeneration.

Oxidized low-density lipoprotein stimulates CD206 positive macrophages upregulating CD44 and CD133 expression in colorectal cancer with high-fat diet

BACKGROUND Oxidized low-density lipoprotein(ox-LDL),which is abnormally increased in the serum of colorectal cancer(CRC)patients consuming a high-fat diet(HFD),may be one of the risk factors for the development of CRC.Ox-LDL exerts a regulatory effect on macrophages and may influence CRC through the tumor microenvironment.The role of ox-LDL in CRC remains unclear.AIM To investigate the role of ox-LDL through macrophages in HFD associated CRC.METHODS The expression of ox-LDL and CD206 was detected in colorectal tissues of CRC patients with hyperlipidemia and HFD-fed mice by immunofluorescence.We stimulated the macrophages with 20μg/mL ox-LDL and assessed the expression levels of CD206 and the cytokines by cell fluorescence and quantitative polymerase chain reaction.We further knocked down LOX-1,the surface receptor of ox-LDL,to confirm the function of ox-LDL in macrophages.Then,LoVo cells were co-cultured with the stimulated macrophages to analyze the CD44 and CD133 expression by western blot.RESULTS The expression of ox-LDL and the CD206 was significantly increased in the stroma of colorectal tissues of CRC patients with hyperlipidemia,and also upregulated in the HFD-fed mice.Moreover,an increased level of CD206 and decreased level of inducible nitric oxide synthase were observed in macrophages after ox-LDL continuous stimulation.Such effects were inhibited when the surface receptor LOX-1 was knocked down in macrophages.Ox-LDL could induce CD206+macrophages,which resulted in high expression of CD44 and CD133 in co-cultured LoVo cells.CONCLUSION Ox-LDL stimulates CD206+macrophages to upregulate CD44 and CD133 expression in HFD related CRC.

Inhibitory Effect of Isorhapontigenin on Copper-Mediated Peroxidation of Human Low-Density Lipoprotein in vitro

Aim To study the effect of Isorhapontigenin (Iso) on copper-mediatedperoxidation of human low-density lipoprotein (LDL) and on the toxicity of oxidized LDL (ox-LDL) tomouse macrophages in vitro. Methods Human LDL from sera df normal lipidemic donors was separated bysequential ultracentrifugation. The separated human IDL 1 mg·mL^(-1) in phosphate buffer saline, pH7.4, was incubated with cupric sulfate (10 μmol·L^(-1) ) at 37℃ for 10 h in the presence orabsence of various concentrations of Iso. Malondialdehyde (MDA) formation, vitamin E consumption,electrophoretic mobility of LDL, mitochondria] membrane potential of mouse peritoneal macrophages,phagocytosis of neutral red, and release of nitric oxide (NO) from macrophages were determined byvarious methods. Results Iso 1 - 100 μmol·L^(-1) significantly inhibited the increase of MDAformation, vitamin E consumption and electrophoretic mobility of LDL induced by Cu^(2+) in aconcentration-dependent manner. The injury of the mitochondrial membrane potential of mouseperitoneal macrophages due to incubation with ox-LDL (0.1 mg·mL^(-1)) at 37℃ for 12 h was markedlyprotected by 10 μmol·L^(-1) Iso. After pretreat-ment of the macrophages with 10 μmol · L^(-1)of Iso and then exposure to ox-LDL for 4 h, the reduction of phagocytosis of neutral red and releaseof NO in response to lipopolysaccharide (IPS) stimulation were significantly prevented. ConclusionIso has protective action against Cu^(2+) - mediated LDL peroxidation and ox-LDL induced toxicity tomacrophages in vitro.

Lectin-like oxidized low-density lipoprotein receptor-1:protein,ligands,expression and pathophvsiological significance

Objective To review the recent research progress in lectin-like oxidized low-density lipoprotein receptor-1 （LOX-1） including its protein, ligands, expression and pathophysiological significance. Data sources Information included in this article was identified by searching of PUBMED （1997-2006） online resources using the key term LOX-1. Study selection Mainly original milestone articles and critical reviews written by major pioneer investigators of the field were selected. Results The key issues related to the LOX-1 protein as well as ligands for LOX-1. Factors regulating the expression of LOX-1 were summarized. The pathophysiological functions of LOX-1 in several diseases were discussed. Conclusions Identification of LOX-1 and a definition of its biological role in pathophysiologic states provide deeper insight into the pathogenesis of some cardiovascular diseases especially in atherosclerosis and provide a potential selective therapeutic approach. LOX-1 is unlocking and drugs targeting LOX-1 might be a promising direction to explore.

Inhibitory Effects of Simvastatin on Oxidized Low-Density Lipoprotein-lnduced Endoplasmic Reticulum Stress and Apoptosis in Vascular Endothelial Cells

Background：Oxidized low-density lipoprotein （ox-LDL）-induced oxidative stress and endothelial apoptosis are essential for atherosclerosis. Our previous study has shown that ox-LDL-induced apoptosis is mediated by the protein kinase RNA-like endoplasmic reticulum kinase （PERK）/eukaryotic translation initiation factor 2α-subunit （eIF2α）/CCAAT/enhancer-binding protein homologous protein （CHOP） endoplasmic reticulum （ER） stress pathway in endothelial cells. Statins are cholesterol-lowering drugs that exert pleiotropic effects including suppression of oxidative stress. This study aimed to explore the roles of simvastatin on ox-LDL-induced ER stress and apoptosis in endothelial cells.Methods：Human umbilical vein endothelial cells （HUVECs） were treated with simvastatin （0.1, 0.5, or 2.5 μmol/L） or DEVD-CHO （selective inhibitor of caspase-3, 100 μmol/L） for 1 h before the addition of ox-LDL （100 μg/ml） and then incubated for 24 h, and untreated cells were used as a control group. Apoptosis, expression of PERK, phosphorylation of eIF2α, CHOP mRNA level, and caspase-3 activity were measured. Comparisons among multiple groups were performed with one-way analysis of variance （ANOVA） followed by post hoc pairwise comparisons using Tukey’s tests. A value of P 〈 0.05 was considered statistically significant.Results：Exposure of HUVECs to ox-LDL resulted in a significant increase in apoptosis （31.9% vs. 4.9%, P 〈 0.05）. Simvastatin （0.1, 0.5, and 2.5 μmol/L） led to a suppression of ox-LDL-induced apoptosis （28.0%, 24.7%, and 13.8%, F = 15.039, all P 〈 0.05, compared with control group）. Ox-LDL significantly increased the expression of PERK （499.5%, P 〈 0.05） and phosphorylation of eIF2α （451.6%, P 〈 0.05）, if both of which in the control groups were considered as 100%. Simvastatin treatment （0.1, 0.5, and 2.5 μmol/L） blunted ox-LDL-induced expression of PERK （407.8%, 339.1%, and 187.5%, F = 10.121, all P 〈 0.05, compared with control group） and phosphorylation of eIF2α （407.8%, 339.1%, 187.5%, F = 11.430, all P 〈 0.05, compared with control group）. In contrast, DEVD-CHO treatment had no significant effect on ox-LDL-induced expression of PERK （486.4%） and phosphorylation of eIF2α （418.8%）. Exposure of HUVECs to ox-LDL also markedly induced caspase-3 activity together with increased CHOP mRNA level; these effects were inhibited by simvastatin treatment.Conclusions：This study suggested that simvastatin could inhibit ox-LDL-induced ER stress and apoptosis in vascular endothelial cells.

Danshen protects endothelial progenitor cells from oxidized low-density lipoprotein induced impairment

In this study, we examined the protective effects of Danshen both on endothelial progenitor cells （EPCs） in patients with hypercholesterolemia and on in-vitro EPCs of healthy volunteers. In the clinical study, we randomly divided 24 subjects with hypercholesterolemia into two groups （the control group and the Danshen-treated group）. At the end of two weeks of treatment, the EPC cellular functions of both groups were tested. The results indicated that, compared to the control group, EPCs in the Danshen-treated group showed significantly better cellular functions, which was manifested in the cloning number, the proliferation capacity, the number of EPC adhesions, and cell migration. In the subsequent in-vitro experiments, EPCs were treated with vehicle, oxidized low-density lipoprotein （Ox-LDL, 100 pg/ml）, or Ox-LDL （100 pg/ml） plus different concentrations of Danshen （Danshensu 2, 10, or 50 pg/ml, respectively） for 24 h. The results showed that Danshen treatments can prevent the detrimental effects of Ox-LDL on EPC cellular functions measured by proliferation capacity （0.24±0.08, 0.37±0.11, 0.30±0.04 vs. 0.13±0.02, P〈0.05, P〈0.01, and P〈0.01, respectively）, and adhesion ability （63.00_±11.60, 70.00±10.80, 85.50±11.41 vs. 40.50±6.85, all P〈0.01）. Compared to the group treated with Ox-LDL alone, Danshen treatment significantly decreased the lipid peroxidation end product malondialdehyde （MDA） [（4.34±0.54）, （3.98±0.47）, （3.46±0.31） vs. （5.57-±0.64） nmol/ml, all P〈0.01], increased the production of superoxide dismutase （SOD） [（29.74±0.71）, （31.09±0.83）, （30.41±0.65） vs. （14.76±3.99） U/ml, all P〈0.01], and lowered the expression of interleukin-6 （IL-6） [（24.62±7.69）, （27.04±3.14）, （33.38±18.86） vs. （230.67±33.53） pg/ml, all P〈0.01] and tumor necrosis factor-α （TNF-α） [（41.72±6.10）, （17.02±6.82）, （3.73±2.26） vs. （228.71±41.53） pg/ml, all P〈0.01] in Ox-LDL treated EPCs. These results suggest that Danshen may exert a protective effect through its antioxidant and anti-inflammatory features.

Metformin improved oxidized low-density lipoprotein-impaired mitochondrial function and increased glucose uptake involving Akt-AS160 pathway in raw264.7 macrophages

Background:Macrophage accumulation in the vascular wall is a hallmark of atherosclerosis.Studies showed that shifting of oxidized lipids-induced inflammatory macrophages towards an anti-inflammatory phenotype by promoting oxidative metabolism attenuated atherosclerosis progression.Therefore,this study aimed to investigate whether metformin,which has ameliorated atherosclerosis in animal models and clinical trials,modulated oxidized low-density lipoprotein (Ox-LDL) induced inflammatory status in macrophages by regulating cellular oxidative metabolism.Methods:Murine raw264.7 macrophages were incubated with Ox-LDL (50 μg/mL) in the presence or absence of metformin (15 μmol/L) for 24 h.Real-time polymerase chain reaction was used to quantify the transcription of classically activated (M1) proinflammatory and alternatively activated (M2) anti-inflammatory markers and mitochondrial DNA copy numbers.Cellular reactive oxygen species (ROS) production and mitochondrial membrane potential were detected by immunofluorescence.Cellular adenosine triphosphate (ATP) synthesis,glucose uptake,and lactic acid production were measured by commercial kit and normalized to cellular lysates.Western blotting analysis was performed to detect the expression of mitochondrial fusion/fission related proteins,enzymes mediating lipid metabolism and signaling pathway of glucose transport.Differences between groups were analyzed using one-way analysis of variance.Results:Metformin improved Ox-LDL-impaired anti-inflammatory phenotype in raw264.7 macrophages as shown by up-regulated transcription of anti-inflammatory markers including interleukin 10 (0.76 ± 0.04 vs.0.94 ± 0.01,P =0.003) and Resistin-like molecule alpha (0.67 ± 0.08 vs.1.78 ± 0.34,P =0.030).Conversely,Ox-LDL-diminished phosphorylation of Akt was up regulated by metformin treatment (0.47 ± 0.05 vs.1.02 ± 0.08,P =0.040),associated with an improvement of mitochondrial function,characterized by decreased ROS generation (2.50 ± 0.07 vs.2.15 ± 0.04,P =0.040),increased lipid oxidation,and elevated cellular ATP production (0.026 ± 0.001 vs.0.035 ± 0.003,P =0.020).Moreover,metformin-mediated Akt activation increased Akt substrate of 160 kDa (AS160) phosphorylation (0.51 ± 0.04 vs.1.03 ± 0.03,P =0.0041),promoted membrane translocation of glucose transporter 1,and increased glucose influx into the cells (4.78 ± 0.04 vs.5.47 ± 0.01,P < 0.001).Contusion:This study suggested that targeting macrophage metabolism with new or existing drugs had therapeutic potential for the prevention and treatment of diabetes-accelerated atherosclerosis.

Association between moderately oxidized low-density lipoprotein and high-density lipoprotein particle subclass distribution in hemodialyzed and post-renal transplant patients

Disturbances in the metabolism of lipoprotein profiles and oxidative stress in hemodialyzed （HD） and post-renal transplant （Tx） patients are proatherogenic, but elevated concentrations of plasma high-density lipoprotein （HDL） reduce the risk of cardiovascular disease. We investigated the concentrations of lipid, lipoprotein, HDL particle, oxidized low-density lipoprotein （ox-LDL） and anti-ox-LDL, and paraoxonase-1 （PON-1） activity in HD （n=33） and Tx （n=71） patients who were non-smokers without active inflammatory disease, liver disease, diabetes, or malignancy. HD patients had moderate hypertriglyceridemia, normocholesterolemia, low HDL-C, apolipoprotein A-I （apoA-I） and HDL particle concentrations as well as PON-1 activity, and increased ox-LDL and anti-ox-LDL levels. Tx patients had hypertriglyceridemia, hypercholesterolemia, moderately decreased HDL-C and HDL particle concentrations and PON-1 activity, and moderately increased ox-LDL and anti-ox-LDL levels as compared to the reference, but ox-LDL and anti-ox-LDL levels and PON-1 activity were more disturbed in HD patients. However, in both patient groups, lipid and lipoprotein ratios （total cholesterol （TC）/HDL-C, LDL-C/HDL-C, triglyceride （TG）/HDL-C, HDL-C/non-HDL-C, apoA-I/apoB, HDL-C/apoA-I, TG/HDL） were atherogenic. The Spearman＇s rank coefficient test showed that the concentration of ox-LDL correlated positively with HDL particle level （R=0.363, P=0.004）, and negatively with TC （R=-0.306, P=0.012）, LDL-C （R=-0.283, P=0.020）, and non-HDL-C （R=-0.263, P=0.030） levels in Tx patients. Multiple stepwise forward regression analysis in Tx patients demonstrated that ox-LDL concentration, as an independent variable, was associated significantly positively with HDL particle level. The results indicated that ox-LDL and de- creased PON-1 activity in Tx patients may give rise to more mildly-oxidized HDLs, which are less stable, easily undergo metabolic remodeling, generate a greater number of smaller pre-13-HDL particles, and thus accelerate reverse cholesterol transport, which may be beneficial for Tx patients. Further studies are necessary to confirm this.

Aqueous Extracts of Tribulus terrestris Protects Against Oxidized Low-Density Lipoprotein-Induced Endothelial Dysfunction

Objective： To investigate the role of aqueous extracts of Tribulus terrestris （TT） against oxidized low-density lipoprotein （ox-LDL）-induced human umbilical vein endothelial cells （HUVECs） dysfunction in vitro. Methods： HUVECs were pre-incubated for 60 min with TT （30 and 3 μg/mL respectively） or 105 mol/L valsartan （as positive controls） and then the injured endothelium model was established by applying 100 μg/mL ox-LDL for 24 h. Cell viability of HUVECs was observed by real-time cell electronic sensing assay and apoptosis rate by Annexin V/PI staining. The cell migration assay was performed with a transwell insert system. Cytoskeleton remodeling was observed by immunofluorescence assay. The content of endothelial nitric oxide synthase （eNOS） was measured by enzyme-linked immunosorbent assay. Intracellular reactive oxygen species （ROS） generation was assessed by immunofluorescence and flow cytometer. Key genes associated with the metabolism of ox-LDL were chosen for quantitative real-time polymerase chain reaction to explore the possible mechanism of TT against oxidized LDL-induced endothelial dysfunction. Results： TT suppressed ox-LDL-induced HUVEC proliferation and apoptosis rates significantly （41.1% and 43.5% after treatment for 3 and 38 h, respectively; P〈0.05）. It also prolonged the HUVEC survival time and postponed the cell＇s decaying stage （from the 69th h to over 100 h）. According to the immunofluorescence and transwell insert system assay, TT improved the endothelial cytoskeletal network, and vinculin expression and increased cell migration. Additionally, TT regulated of the synthesis of endothelial nitric oxide synthase and generation of intracellular reactive oxygen species （P〈0.05）. Both 30 and 3μg/mL TT demonstrated similar efficacy to valsartan. TT normalized the increased mRNA expression of PI3Kα and Socs3. It also decreased mRNA expression of Aktl, AMPKα, JAK2, LepR and STAT3 induced by ox-LDL. The most notable changes were JAK2, LepR, PI3Kα, Socs3 and STAT3. Conclusions： TT demonstrated potential lowering lipid benefits, anti-hypertension and endothelial protective effects. It also suggested that the JAK2/STAT3 and/or PI3K/AKT pathway might be a very important pathway which was involved in the pharmacological mechanism of TT as the vascular protective agent.

Protective Effect of Propyl Gallate Against Oxidized Low-Density Lipoprotein-Induced Injury of Endothelial Cells

Objective： To evaluate the protective effect of propyl gallate （PG）, an alkyl ester of gallic acid which is an active ingredient of Radix Paeoniae, against oxidized low-density lipoprotein （ox-LDL）-induced apoptosis and death in endothelial cells （ECs） and to find out its preliminary mechanism. Methods： The cultured endothelial cells were divided into normal, model （ox-LDL）, control （fetal bovine serum）, PG high dose （20 p,g/mL）, PG middle dose （10 μg/mL）, and PG low dose （5 μg/mL） groups, each derived from three different pools of umbilical cords. The model of injured human umbilical vein endothelial cells （HUVECs） was induced by ox-LDL. The 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl-2H-tetrazolium bromide （MTT） assay, Hoechst 33258 staining, flow cytometry and measurement of nitrogen monoxidum （NO） release were used to evaluate the protective effect of PG against ox-LDL-induced apoptosis and death in HUVECs. To find out the mechanism of this protective effect, the expression of endothelial nitric oxide synthase （eNOS） mRNA, eNOS protein expression, immunofluorescence of intracellular reactive oxygen species （ROS） and activities of malondialdehyde （MDA）, superoxidedismutase （SOD） and glutathione peroxidase （GPx） were observed. Results： PG significantly reduced ox-LDL-induced apoptosis and cell death. The percentage of cells death and apoptosis was significantly higher in the ox-LDL group than that in the control group （P〈0.05）. Compared with the control group, the cells death and apoptosis of PG group was no different （P〉0.05）. As compared with the ox-LDL group, results of the PG high dose group showed that cell viability was significantly increased （P〈0.05）, the level of NO release, expression of eNOS mRNA, densitometric value of eNOS protein expression, as well as the activities of SOD and GPx were all significantly higher （all P〈0.05）. Conclusion： PG could potentially serve as a novel endothelial protective agent against ox-LDL-induced injury of endothelial cell.

Atorvastatin attenuates oxidative stress in Alzheimer's disease

Objective： To investigate serum level of SOD, MDA, ox-LDL, AchE and Ach in AD, to study atorvastatin influence on serum level of SOD, MDA, ox-LDL, Ache and Ach in AD and its neuroprotection mechanisms. Methods Subjects were divided into： normal blood lipid level group with Alzheimer＇s disease （A）, higher blood lipid level group with Alzheimer＇s disease （AH）, normal blood lipid level Alzheimer＇s disease group with atorvastatin treeatment （AT）, higher blood lipid level Alzheimer＇s disease group with atorvastatin treeatment（AHT）. Ox-LDL was measured by enzyme linked immunosorbent assay; SOD, MDA, ox-LDL, AchE, Ach and blood lipid level in AD was measured by biochemistry. Results： The serum level of MDA, Ache in AH group after atorvastatin treatment is lower ;The serum level of SOD, Ach in AH group is more increased than that of in A group; The serum level of ox-LDL in AH, A groups is lower than that of in A group; The dementia degree is lower after atorvastatin treatment. Conclusion： Atorvastatin can decrease serum level of MDA, AchE and ox-LDL, and increase that of SOD, Ach, and attenuate dementia symptom in AD, especially, with hyperlipemia. The hypothesis of atorvastatin neuroprotection is concluded that atorvastatin may restrain free radical reaction and retard oxidation in AD.

Oxidative alterations in sickle cell disease: Possible involvement in disease pathogenesis

Sickle cell disease(SCD) is the first molecular disease in the literature. Although the structural alteration and dysfunction of the sickle hemoglobin(HbS) are well understood, the many factors modifying the clinical signs and symptoms of the disease are under investigation. Besides having an abnormal electrophoretic mobility and solubility, HbS is unstable. The autooxidation rate of the abnormal HbS has been reported to be almost two times of the normal. There are two more components of the oxidative damage in SCD: Free radical induced oxidative damage during vaso-occlusion induced ischemia-reperfusion injury and decreased antioxidant capacity in the erythrocyte and in the circulation. We will discuss the effects of oxidative alterations in the erythrocyte and in the plasma of SCD patients in this review.

IgM亚类抗体3A6抑制ApoE^(-/-)小鼠动脉粥样硬化斑块形成

目的探究天然属性抗氧化低密度脂蛋白(oxidized low density lipoprotein,ox-LDL)IgM亚类抗体3A6对ApoE^(-/-)小鼠动脉粥样硬化斑块形成的影响。方法以ApoE^(-/-)小鼠为研究对象,将小鼠(18只)随机分为3组,即对照组(腹腔注射0.9%氯化钠溶液)、5G8组(腹腔注射天然属性抗LDL的IgM亚类抗体)和3A6组(腹腔注射天然属性的抗ox-LDL的IgM亚类抗体),每组各6只。高脂高胆固醇饮食饲喂12周,观察各组小鼠体质量,检测小鼠血脂的水平;苏木精-伊红染色分析小鼠主动脉的病理变化及斑块面积。结果3组小鼠的体质量、血脂水平和ox-LDL水平比较,差异无统计学意义(P=0.087);与对照组比较,3A6组小鼠动脉粥样硬化斑块面积显著减少,差异有统计学意义(P=0.023)。结论天然IgM亚类抗体3A6能够抑制ApoE^(-/-)小鼠动脉粥样硬化斑块的形成。

凝集素样氧化型低密度脂蛋白受体-1对乙醇诱导的大鼠心肌细胞自噬的影响

目的探讨乙醇诱导下大鼠心肌细胞模型中凝集素样氧化型低密度脂蛋白受体-1(lectin-like oxidized low density lipoprotein receptor 1,LOX-1)的表达及其与自噬相关蛋白Beclin-1和自噬微管相关蛋白轻链3抗体Ⅱ(autophagy microtubule-associated protein light chain 3 antibodyⅡ,LC3-Ⅱ)的相关关系。方法选取对数生长期的大鼠心肌细胞随机分为以下6组:Blank组、乙醇组、乙醇+sh-NC组、乙醇+sh-LOX-1组、乙醇+OE-LOX-1组和乙醇+OE-LOX-1+si-NC组,除空白对照组外,其余各组细胞均用200 mmol/L酒精孵育1 d,体外构建乙醇诱导的大鼠心肌细胞模型。电镜观察自噬小体的数量。实时荧光定量PCR(Realtime PCR)和蛋白印迹法(Western blot)分别检测LOX-1、Beclin-1、LC3-I、LC3-Ⅱ在各组中的表达水平,并进行比较与分析。结果急性乙醇暴露后可使大鼠心肌细胞中LOX-1、Beclin-1、LC3-I和LC3-Ⅱ在基因和蛋白水平表达明显升高(P<0.01)。对LOX-1的表达抑制后,Beclin-1、LC3-I和LC3-Ⅱ表达明显下调(P<0.01),而在对LOX-1进行过表达处理后,则能够增加Beclin-1、LC3-I和LC3-Ⅱ的表达水平(P<0.01)。透射电镜下,急性乙醇摄入可造成大鼠心肌细胞中自噬小体增多;下调LOX-1后可减少自噬小体数量,而过表达LOX-1则会增加自噬小体数量(P<0.01)。结论LOX-1在急性乙醇诱导下的大鼠心肌细胞模型中表达上调,且与自噬相关因子(Beclin-1、LC3-Ⅱ)呈协同变化趋势,提示LOX-1可能通过上调Beclin-1和LC3-Ⅱ表达水平造成自噬水平的过度激活从而推动酒精致心肌损伤的病理过程。

云芝多糖对实验性动脉粥样硬化家兔血浆氧化型低密度脂蛋白含量的影响

用本室制备的两株单克隆抗体（ＨＯＬ２和ＨＯＬ５）比较了经与未经云芝多糖治疗的实验性动脉粥样硬化家兔血浆氧化型低密度脂蛋白的含量。发现血浆氧化型低密度脂蛋白以低、中修饰度低密度脂蛋白为主；血浆氧化型低密度脂蛋白水平与主动脉粥样硬化斑块面积成正相关；云芝多糖能降低血浆氧化型低密度脂蛋白水平。提示利用单克隆抗体检测血浆氧化型低密度脂蛋白含量可初步预测动脉粥样硬化严重程度；云芝多糖降低血浆氧化型低密度脂蛋白水平可能是其减轻动脉粥样硬化斑块面积的机理之一。

抗磷脂抗体对巨噬细胞摄取氧化型低密度脂蛋白及CD36表达的影响

为了探讨抗磷脂抗体对巨噬细胞摄入氧化型低密度脂蛋白的影响及其主要清道夫受体CD36抗原表达的调节 ,将培养的U937细胞与氧化型低密度脂蛋白 (80mg L)和抗磷脂抗体 (10 0mg L)孵育 ,用酶荧光法观察人类单核细胞株U937内脂质的变化、逆转录—聚合酶链反应和流式细胞术观察CD36抗原mRNA和蛋白水平表达的改变。结果发现氧化型低密度脂蛋白存在时细胞内胆固醇和胆固醇酯含量分别为 2 4 3± 9mg g细胞和 2 89± 12mg g细胞 ,流式细胞仪测CD36抗原为 2 5 % ,凝胶电泳分析CD36mRNA β actionmRNA为 1.0 5 ;在加入抗磷脂抗体后 ,胞浆内胆固醇和胆固醇酯明显增加 ,分别为 2 76± 10mg g细胞和 4 78± 13mg g细胞 ,流式细胞仪测CD36抗原为 37% ,凝胶电泳分析CD36mRNA β actionmRNA为 1.90 ;两组相比差异有显著性 (P <0 .0 5 )。以上提示抗磷脂抗体有促进U937细胞摄取氧化型低密度脂蛋白的作用 。

黑米皮抗载脂蛋白E基因缺陷小鼠动脉粥样硬化形成及机制

为研究黑米皮对载脂蛋白E基因缺陷小鼠血清抗氧化型低密度脂蛋白抗体水平的影响 ,探讨黑米皮抗动脉粥样硬化作用的机制。选用载脂蛋白E基因缺陷小鼠进行实验 ,通过在载脂蛋白E基因缺陷小鼠普通饲料AIN 93中添加 5 %黑米皮 ,检测载脂蛋白E基因缺陷小鼠主动脉窦动脉粥样斑块面积和血清抗氧化型低密度脂蛋白抗体的水平。结果发现 ,黑米皮可降低载脂蛋白E基因缺陷小鼠主动脉窦动脉粥样斑块面积以及血清中抗氧化型低密度脂蛋白抗体的水平 ,且二者之间呈显著性相关 (r=0 .6 38,P <0 .0 1)。这表明黑米皮的抗动脉粥样硬化作用可能与其降低抗氧化型低密度脂蛋白抗体水平有关。