Proof of Aerobically Autoxidized Self-Charge Concept Based on Single Catechol-Enriched Carbon Cathode Material

The self-charging concept has drawn considerable attention due to its excellent ability to achieve environmental energy harvesting,conversion and storage without an external power supply.However,most self-charging designs assembled by multiple energy harvesting,conversion and storage materials increase the energy transfer loss;the environmental energy supply is generally limited by climate and meteorological conditions,hindering the potential application of these selfpowered devices to be available at all times.Based on aerobic autoxidation of catechol,which is similar to the electrochemical oxidation of the catechol groups on the carbon materials under an electrical charge,we proposed an air-breathing chemical self-charge concept based on the aerobic autoxidation of catechol groups on oxygen-enriched carbon materials to ortho-quinone groups.Energy harvesting,conversion and storage functions could be integrated on a single carbon material to avoid the energy transfer loss among the different materials.Moreover,the assembled Cu/oxygen-enriched carbon battery confirmed the feasibility of the air-oxidation self-charging/electrical discharging mechanism for potential applications.This air-breathing chemical self-charge concept could facilitate the exploration of high-efficiency sustainable air self-charging devices.

The Adsorption Properties of TEMPO Oxidized Cellulose against the Mixture of Methylene Blue and Rhemazol Yellow FG

TEMPO/NaOCl/NaBr treatment significantly increased the number of negative charges on the cellulose surface.Two concentrations of NaOCl,5 and 30 mmol/g of cellulose,were used in this study.The number of carboxyl groups in the two cellulosic samples oxidized using TEMPO/NaOCl/NaBr was 0.5160 and 1.8461 mmol/g of cellulose,respectively.The oxidized cellulose samples treated with 5 and 30 mmol/g NaOCl exhibited higher crystallinity,at 81.15%and 80.14%,respectively,compared to untreated cellulose,which had a crystallinity of 75.95%.The pH effect indicated that the highest adsorption capacity for methylene blue was achieved under alkaline conditions(pH 9),while the highest adsorption capacity for rhemazol yellow FG was achieved under acidic conditions.The kinetic model of TEMPO-oxidized cellulose for methylene blue and rhemazol yellow FG conformed to the pseudo-second-order model.The initial concentration parameter revealed that the isotherm model for the adsorption of methylene blue and rhemazol yellow FG by TEMPO-oxidized cellulose conformed to the Langmuir model.The dye removal efficiencies for methylene blue and rhemazol yellow FG using TEMPOoxidized cellulose(30 mmol/g)were approximately 80.17%and 59.52%,respectively.These results demonstrate that TEMPO/NaOCl/NaBr-oxidized samples can effectively separate cationic and anionic dye mixtures.Furthermore,the use of TEMPO-oxidized cellulose showed good regeneration capability,maintaining more than 95%of its adsorption capacity after 8 cycles.

Research Progress in Preparation of Oxidized Cellulose

Cellulose is the most abundant natural polymer material in the world.Cellulose is diffi-cult to dissolve because it contains a large number of inter molecular hydrogen bonds.Therefore,the modification of natural cellulose by chemical oxidation can expand its application field.The oxidation process of cellulose is focused on,the oxidation methods and research progress of cellulose are introduced,and further development direction of oxidized cellulose is prospected.

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.

Resveratrol alleviates oxidative stress induced by oxidized soybean oil and improves gut function via changing gut microbiota in weaned piglets

Background Oxidized soybean oil(OSO)has been shown to impair growth and exacerbate inflammation,leading to intestinal barrier injury in animals.Recent evidence suggests important roles for resveratrol(RES)in the promoting growth performance,antioxidant capacity,anti-inflammatory,and regulate intestinal barriers in animals.Therefore,The objectives of this study are to investigate the effects of dietary RES(purity 98%)supplementation on the growth performance,antioxidant capacity,inflammatory state,and intestinal function of weaned piglets challenged with OSO.Methods A total of 28 castrated weaned male piglets with a similar body weight of 10.197 replications per treatment and±0.10 kg were randomly assigned to 4 dietary treatments for 28-d feeding trial with 1 piglet per replicate.Treatments were arranged as a 2×2 factorial with oil type[3%fresh soybean oil(FSO)vs.3%OSO]and dietary RES(0vs.300 mg/kg).Results The results showed that relative to the FSO group,OSO stress tended to decrease the average daily feed intake(ADFI),and decreased the activity levels of lipase,villus/crypt ratio(VCR),the mRNA expression of FABP1,SOD2,IL-10 and ZO-1 in the jejunum,and SOD2,GPX1,occludin and ZO-1 in the colon,the levels of acetic acid in the colonic digesta,whereas up-regulated the mRNA expression of IL-1βand TNF-αin the jejunum(P<0.05).Moreover,dietary supplementation with RES increased ether extract(EE),the activity levels of sucrase,lipase,α-amylase,villus height(VH)and VCR,the mRNA expression of FABP1,SOD2,IL-10 and occludin in the jejunum,and FABP1,PPAR-γ,GPX1,occludin and ZO-1 in the colon,and the abundance of Firmicutes,acetic and propionic acid,but decreased the levels of D-lactic acid in the plasma,the abundance of Bacteroidetes in the colonic digesta of weaned piglets compared to the non-RES group(P<0.05).Meanwhile,in the interaction effect analysis,relative to the OSO group,dietary RES supplementation in the diets supplemented with OSO increased the activity levels of trypsin,VH in the jejunum,the abundance of Actinobacteria,the levels of butyric acid of weaned piglets,but failed to influence the activity levels of trypsin and VH,Actinobacteria abundance,the levels of butyric acid when diets were supplemented with FSO(interaction,P<0.05).Relative to the OSO group,dietary RES supplementation in the diets supplemented with OSO decreased the activity levels of DAO in the plasma of weaned piglets but failed to influence the activity levels of DAO when diets were supplemented with FSO(interaction,P<0.05).Relative to the FSO group,dietary RES supplementation in the diets supplemented with FSO decreased the level of propionic acid,whereas RES supplementation failed to influence the level of propionic acid when the diet was supplemented with OSO(interaction,P<0.01).Conclusions Inclusion of OSO intensified inflammatory states and impaired the intestinal health characteristics of weaned piglets.Dietary RES supplementation improved the antioxidant capacity,anti-inflammatory activity,and intestinal morphology.Further studies showed that the protective effects of RES on gut health could be linked to the decreased abundance of Prevotella_1,Clostridium_sensu_stricto_6,and Prevotellaceae_UCG003 and increased levels of acetic and propionic acid.

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.

Influence of Oxidized Low Density Lipoprotein on the Proliferation of Human Artery Smooth Muscle Cells in vitro

The effects of oxidized low density lipoprotein （ox-LDL） on the proliferation of cultured human vascular smooth muscle cells （vSMC） were investigated in vitro. By using NaBr density gradient centrifugation, LDL was isolated and purified from human plasma. Ox-LDL was produced from LDL by being incubated with CuSO4. ox-LDL was then added to the culture medium at different concentrations （35, 60, 85, 110, 135 and 160μg/mL） for 7 days. The influence of ox-LDL on vSMC proliferation was observed in growth curve, mitosis index, and in situ determination of apoptosis. The data were analyzed with SPSS 10.0 software. The results showed that the ox-LDL produced in vitro had a good purity and optimal oxidative degree, which was similar to the intrinsic ox-LDL in atherosclerotic plaque, ox-LDL at a concentration of 35 μg/mL demonstrated the strongest proliferation inducement, and at a concentration of 135 μg/mL, ox-LDL could inhibit the growth of vSMC. ox-LDL at concentrations of 35 and 50 μg/mL presented powerful mitotic trigger, and with the increase of ox-LDL concentration, the mitotic index of vSMC was decreased gradually, ox-LDL at higher concentrations promoted more apoptotic vSMCs, ox-LDL at lower concentrations triggered proliferation of vSMCs, and at higher concentrations induced apoptosis in vSMCs, ox-LDL played a promotional role in the pathogenesis and development of atherosclerosis by affecting vSMC proliferation and apoptosis.

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.

Effects of Oxidized Low Density Lipoprotein on Transformation of Valvular Myofibroblasts to Osteoblast-like Phenotype

In order to investigate the roles of Wnt signal pathway in transformation of cardiac valvular myofibroblasts to the osteoblast-like phenotype, the primary cultured porcine aortic valve myofibroblasts were incubated with oxidized low density lipoprotein（ox-LDL, 50 mg/L）, and divided into four groups according to the ox-LDL treatment time： control group, ox-LDL 24-h group, ox-LDL 48-h group, and ox-LDL 72-h group. Wnt signal pathway blocker Dickkopf-1（DDK-1, 100 μg/L） was added in ox-LDL 72-h group. The expression of α-smooth muscle actin（α-SMA）, bone morphogenetic protein 2（BMP2）, alkaline phosphatase（ALP）, and osteogenic transcription factor Cbfa-1 was detected by Western blotting, and that of β-catenin, a key mediator of Wnt signal pathway by immunocytochemical staining method. The Wnt/β-catenin was observed and the transformation of myofibroblasts to the osteoblast-like phenotype was examined. The expression of α-SMA, BMP2, ALP and Cbfa-1 proteins in the control group was weaker than in the ox-LDL-treated groups. In ox-LDL-treated groups, the protein expression of α-SMA, BMP2, ALP, and Cbfa-1 was significantly increased in a time-dependent manner as compared with the control group, and there was significant difference among the three ox-LDL-treated groups（P〈0.05 for all）; β-catenin protein was also up-regulated in the ox-LDL-treated groups in a time-dependent manner as compared with the control group（P〈0.05）, and its transfer from cytoplasm to nucleus and accumulation in the nucleus were increased in the same fashion（P〈0.05）. After addition of DKK-1, the expression of α-SMA, bone-related proteins and β-catenin protein was significantly reduced as compared with ox-LDL 72-h group（P〈0.05）. The Wnt/ β-catenin signaling pathway may play an important role in transformation of valvular myofibroblasts to the osteoblast-like phenotype.

Understanding on corrosion mechanism of oxidized AZW800 alloy in 3.5 wt%NaCl solution

Magnesium alloys are more widely used at higher temperatures.However,it is not well known whether oxide layer,produced at high temperature,could show corrosion protection.Thus,the corrosion behaviors of oxidized AZW800 alloy were investigated by hydrogen evolution and electrochemical measurements to evaluate effect of oxide layer on corrosion resistance.The results showed that corrosion of removed oxide layer AZW800 alloy showed characteristic of localized corrosion,leaving randomly bulky pits.While reserved oxide layer AZW800 alloy exhibited a relatively uniform corrosion.The results indicated that oxide layer could hinder corrosion of oxidized AZW800 alloy in the initial period of immersion.While subsequently,aggravated corrosion would occur owing to defects of oxide layer and less protective products film.Besides,present of oxide layer eliminated micro-galvanic couple on alloy surface.The synergistic effect of elimination of micro-galvanic couple on alloy surface and alkalization effect transforms localized corrosion into relatively uniform corrosion of alloys.

OXIDIZED HIGH-DENSITY LIPOPROTEIN PROMOTES MATURATION AND MIGRATION OF BONE MARROW DERIVED DENDRITIC CELLS FROM C57BL/6J MICE

Objective To explore the influence of oxidized high-density lipoprotein （oxHDL） on the maturation and migration of bone marrow-derived dendritic cells （BMDCs） from C57BL/6J mice. Methods The C57BL/6J mice bone marrow cell suspension was prepared and purified. Recombinant granulocyte-macrophage colony-stimulating factor （rmGM-CSF） and recombinant interleukin-4 （rmlL-4） were used to promote monocytes to differentiate and suppress lymphocytes. Then 50μg/mL oxHDL was added to stimulate BMDCs, using 50μg/mL high-density lipoprotein （HDL） as homologous protein control, PBS as negative control, and 1 μg/mL lipopolysaccharide （LPS） as positive control. The CD86 and MHCII expression rates were detected with fluorescence-activated cell sorting （FACS）. Liquid scintillation counting （LSC） was used in mixed lymphocyte reactions （MLRs） to reflect the ability of BMDCs in stimulating the proliferation of homologous T cells, Levels of cytokines IL-12 and IL-10 were detected by ELISA. The cell migration was evaluated with the transwell system. Results Compared with PBS group, the expressions of CD86 and MHCII, counts per minute of MLRs, secretion of IL-12 and IL-10, and number of migrated cells in oxHDL group and LPS group significantly increased （all P 〈 0.05）, while the increment was less in oxHDL group than LPS group. The number of migrated cells in oxHDL group was about twice of that in HDL group. Conclusion OxHDL may promote the maturation and migration of BMDCs in vitro.

Oxidized phospholipids and lipoprotein-associated phospholipase A_2 as important determinants of Lp(a) functionality and pathophysiological role

Lipoprotein（a） [Lp（a）] is composed of a low density lipoprotein（LDL）-like particle to which apolipoprotein（a）[apo（a）] is linked by a single disulfide bridge. Lp（a） is considered a causal risk factor for ischemic cardiovascular disease（CVD） and calcific aortic valve stenosis（CAVS）. The evidence for a causal role of Lp（a） in CVD and CAVS is based on data from large epidemiological databases, mendelian randomization studies, and genome-wide association studies. Despite the well-established role of Lp（a） as a causal risk factor for CVD and CAVS, the underlying mechanisms are not well understood. A key role in the Lp（a） functionality may be played by its oxidized phospholipids（OxPL） content. Importantly, most of circulating OxPL are associated with Lp（a）; however, the underlying mechanisms leading to this preferential sequestration of OxPL on Lp（a） over the other lipoproteins,are mostly unknown. Several studies support the hypothesis that the risk of Lp（a） is primarily driven by its OxPL content.An important role in Lp（a） functionality may be played by the lipoprotein-associated phospholipase A_2（Lp-PLA_2）,an enzyme that catalyzes the degradation of OxPL and is bound to plasma lipoproteins including Lp（a）. The present review article discusses new data on the pathophysiological role of Lp（a） and particularly focuses on the functional role of OxPL and Lp-PLA_2 associated with Lp（a）.

FUCOIDIN INHIBITS OXIDIZED LOW DENSITY LIPOPROTEIN FROM INDUCING HUMAN PERIPHERAL BLOOD MONOCYTE EXPRESSION OF PROINFLAMMATORY CYTOKINES mRNA

Objective To study the significance of scavenger receptor class A(SR A)in mediating human peripheral blood monocyte to uptake oxidized low density lipoprotein(OxLDL) and promoting the atherosclerotic immuno pathological lesion in the local blood vessel. Methods With the Digoxenin labeled Oligonucleotide probes In situ Hybridization, this research investigated the effects of OxLDL on the mRNA expression of proinflammatory cytokines including MCP 1, bFGF, PDGF and IL 10 in the human peripheral blood monocyte and whether fucoidin, a peculiarly inhibitory ligand for SR A, would influence this process. Results Monocyte was significantly increased the mRNA expression of MCP 1, bFGF, PDGF and IL 10 in a dose dependent manner after incubating with OxLDL (10,15,20,25,30?mg·L -1 , respectively)for 24 hours( P < 0.001 ). Fucoidin(50,100,150,200,250?mg·mL -1 , respectively)completely inhibited OxLDL(20?mg·L -1 )from inducing monocyte the mRNA expression of above proinflammatory cytokines( P < 0.001 ). Conclusion OxLDL can stimulate human peripheral blood monocyte to give expression to proinflammatory cytokines mRNA in a dose dependent manner, while a peculiarly inhibitory ligand for SR A fucoidin has an obviously opposed role.

Obstructive jaundice leads to accumulation of oxidized low density lipoprotein in human liver tissue

Oxidized low density lipoprotein （ox-LDL） molecule is one of the most important modified lipoproteins produced during the oxidative stress. Modified lipoproteins have been defined as being part of the immune inflammatory mechanisms in association with oxidant stress. We have reported the accumulation of ox-LDL in Balb/c mice liver after bile duct ligation previously. Here, we investigated this finding in human beings with obstructive jaundice. Our study demonstrates that obstructive jaundice results in tremendous accumulation of ox-LDL in the liver tissue of patients.

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.

Competitive oxidation behavior of Ni-based superalloy GH4738 at extreme temperature

A high thrust-to-weight ratio poses challenges to the high-temperature performance of Ni-based superalloys. The oxidation behavior of GH4738 at extreme temperatures has been investigated by isothermal and non-isothermal experiments. As a result of the competitive diffusion of alloying elements, the oxide scale included an outermost porous oxide layer (OOL), an inner relatively dense oxide layer (IOL), and an internal oxide zone (IOZ), depending on the temperature and time. A high temperature led to the formation of large voids at the IOL/IOZ interface. At 1200℃, the continuity of the Cr-rich oxide layer in the IOL was destroyed, and thus, spallation occurred. Extension of oxidation time contributed to the size of Al-rich oxide particles with the increase in the IOZ. Based on this finding,the oxidation kinetics of GH4738 was discussed, and the corresponding oxidation behavior at 900-1100℃ was predicted.

Oxidized low density lipoprotein (Ox-LDL) impacts on erythrocyte viscoelasticity and its molecular mechanism

Aim:The oxidized low-density lipoprotein(OxLDL) plays an important role in atherosclerosis yet it remains unclear if it damages circulating erythrocytes. Method: In this study。

Effects of Pitavastatin on Lipoprotein Subfractions and Oxidized Low-density Lipoprotein in Patients with Atherosclerosis

It has been demonstrated that pitavastatin can significantly reduce low-density lipoprotein(LDL)cholesterol(LDL-C),but its impact on lipoprotein subfractions and oxidized low-density lipoprotein(oxLDL)has not been determined.The aim of the present study was to investigate the potential effects of pitavastatin on subfractions of LDL and high-density lipoprotein(HDL)as well as oxLDL in untreated patients with coronary atherosclerosis(AS).Thirty-six subjects were enrolled in this study.O f them,18 patients with AS were administered pitavastatin 2 mg/day for 8 weeks and 18 healthy subjects without therapy served as controls.The plasma lipid profile,lipoprotein subfractions and circulating oxLDL were determined at baseline and 8 weeks respectively.The results showed that pitavastatin treatment indeed not only decreased LDL-C,total cholesterol(TC),triglycerides(TG)and apolipoprotein B(ApoB)levels,and increased HDL cholesterol(HDL-C),but also reduced the cholesterol concentration of all of the LDL subfractions and the percentage of intermediate and small LDL subfractions.Meanwhile,pitavastatin could decrease plasma oxLDL levels.Furthermore,a more close correlation was found between oxLDL and LDL-C as well as LDL subfractions after pitavastatin treatment.We concluded that a moderate dose of pitavastatin therapy not only decreases LDL-C and oxLDL concentrations but also improves LDL subfractions in patients with AS.

Expression of Monocyte Chemoattractant Protein-1 in Monocytes and Effects of Native and Oxidized Very Low Density Lipoproteins

Monocyte chemoattractant protein-1(MCP-1), a potent chemoattractant, is thought to play an important role in migration of monocytes into atherosclerotic lesions. The present study was designed to investigate the capacity of human peripheral blood monocytes to express MCP-1 and effects of native very low density lipoprotein (VLDL) and oxidized VLDL(OX-VLDL) on the expression. The total RNA was extracted from cultured monocytes, which were exposed to VLDL and OX-VLDL, and the media conditioned by monocytes were collected. MCP-1 mRNA expression was examined by Northern blot analysis. MCP-1 protein in conditioned media was determined by using sandwich ELISA. The results showed that monocytes can express MCP-1 after a 24 h incubation at 37℃，and the expression was markedly increased by a exposure to OX-VLDL, whereas the expression was slightly increased when exposed to VLDL. It suggests that the capacity of monocytes to produce MCP-1 that recruits and activates circulating monocytes may be of considerable importance in atherogenesis, and oxidation of VLDL enhances its potential to promote atherogenesis.

Effects of Oxidized Low Density Lipoprotein onthe Expression and Function of ABCA1 in Macrophages

Summary:In the present study, we examined the regulation of the expression and function of ABCA1 by modified LDL (ox-LDL) in vitro. After incubation with apoA-I for 24 h, RAW264.7 cells effluxed 37.65 % cholesterol loaded by acetyl LDL (ac-LDL), and 9.78 % cholesterol in ox-LDL group. The level of ABCA1 mRNA increased about three times either when cells were incubated with 100 μg /mL ac-LDL or with 100 μg /mL ox-LDL. However, the level of ABCA1 protein rose by 1.57 times in ac-LDL group and 1.26 times in ox-LDL group. These results demonstrated that ox-LDL had different effect on the expression and function of ABCA1, ox-LDL might decrease the cholesterol efflux mediated by ABCA1 through other unknown mechanisms.