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。
Whereas the close structural homology between human plasminogen and apolipoprotein(a) has been known for a number of years only recent studies have revealed that both proteins carry linked oxidized phospholipids that ...Whereas the close structural homology between human plasminogen and apolipoprotein(a) has been known for a number of years only recent studies have revealed that both proteins carry linked oxidized phospholipids that may modify the function of these proteins. Future studies should provide a better understanding of oxidized phospholipid adducts and the role played by lipoprotein-associated phospholipase A2 for which cleavage specificity has been established when these modified lipids are in a free form.展开更多
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 th...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.展开更多
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 wa...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.展开更多
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 represe...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.展开更多
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 wi...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.展开更多
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...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.展开更多
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 is...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).展开更多
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...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.展开更多
Mitofusin2 (Mfn2) plays a pivotal role in the proliferation and apoptosis of vascular smooth muscle cells (VSMCs). The purpose of this study was to investigate the effects of Mfn2 on the traffick- ing of intracell...Mitofusin2 (Mfn2) plays a pivotal role in the proliferation and apoptosis of vascular smooth muscle cells (VSMCs). The purpose of this study was to investigate the effects of Mfn2 on the traffick- ing of intracellular cholesterol in the foam ceils derived from rat VSMCs (rVSMCs) and also to investigate the effects of Mfn2 on the expression of adenosine triphosphate-binding cassette subfamily A member 1 (ABCA1), adenosine triphosphate-binding cassette subfamily G member 1 (ABCG1) and peroxisome proliferator-activated receptor gamma (PPARy). The rVSMCs were co-cultured with oxi- dized low density lipoprotein (LDL, 80 ~tg/mL) to produce foam cells and cholesterol accumulation in cells. Before oxidized LDL treatment, different titers (20, 40 and 60 pfu/cell) of recombinant adenovirus containing Mfn2 gene (Adv-Mfn2) were added into the culture medium for 24 h to transfect the Mfn2 gene into the rVSMCs. Then the cells were harvested for analyses. The protein expression of Mfn2 was significantly higher in Adv-Mfn2-transfected group than in untransfected group (P〈0.05), and the ex- pression levels significantly increased when the titer of Adv-Mfn2 increased (P〈0.05). At 24 or 48 h af- ter oxidized LDL treatment, rVSMCs became irregular and their nuclei became larger, and their plasma abounded with red lipid droplets. However, the number of red lipid droplets was significantly decreased in Adv-Mfn2-transfected group as compared with untransfected group. At 48 h after oxidized LDL treatment, the intracellular cholesterol in rVSMCs was significantly increased (P〈0.05), but it was sig- nificantly decreased in Adv-Mfn2-transfected group as compared with untransfected group (P〈0.05), and it also significantly decreased when the titer of Adv-Mfn2 increased (P〈0.05). The mRNA and pro- tein expression levels of ABCA1 and ABCG1 were significantly increased in Adv-Mfn2-transfected group as compared with untransfected group (P〈0.05). Though the mRNA and protein expression levels of PPARy was not significantly increased (P〉0.05), the phosporylation levels of PPARy were signifi- cantly decreased in Adv-Mfn2-transfected group as compared with untransfected group (P〈0.05). These results suggest that the transfection of Adv-Mfn2 can significantly reduce intracellular cholesterol in oxidized LDL-induced rVSMCs possibly by decreasing PPAR'/phosporylation and then increasing pro- tein expression levels of ABCAI and ABCG1, which may be helpful to suppress the formation of foam cells.展开更多
Objective To investigate the molecular mechanism of atherosclerosis that related to age. Methods Immunohistochemistry staining and Western blot were adopted to determine the nuclear translocation of nuclear factor-kap...Objective To investigate the molecular mechanism of atherosclerosis that related to age. Methods Immunohistochemistry staining and Western blot were adopted to determine the nuclear translocation of nuclear factor-kappa B (NF-κB) and expression of platelet-derived growth factor B (PDGF-B) in smooth muscle cells (SMCs) co-cultured with low density lipoprotein (LDL), oxidized LDL (ox-LDL), and ox-LDL+high density lipoprotein (HDL) originated from rats of 2 and 10 months old respectively. Fat stain was used to identify the lipid intake in SMCs. Results The optimal stimulation time of ox-LDL to SMCs was 12 hours. NF-κB intensity increased in most nuclei of SMCs that originated from rats of either 2 or 10 months old co-cultured with ox-LDL. The intensity of NF-κB and the amount of intracellular lipid taken in SMCs were more obvious in cells from 10-month-old rats than from the younger ones. Change of PDGF-B expression in SMCs was not remarkable in each group of rats. Conclusions The 10-month-old rats are more susceptive to ox-LDL than 2-month-old rats in activating nuclear transloca- tion of NF-κB. Maybe this is one of the important reasons contributing to the difference between the older and younger rats on the initiation and development of atherosclerosis lesion. Expression of PDGF-B is not associated with the activity of nuclear translocation of NF-κB.展开更多
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 inflamm...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.展开更多
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 ma...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.展开更多
Mouse peritoneal macrophages were incubated in DMEM with pox-LDL and Rradlx Salviae Miltiorrhizae (RSM) to investigate the effects of RSM on the internalization of peroxidized low density lipoprotein (pox-LDL) by usin...Mouse peritoneal macrophages were incubated in DMEM with pox-LDL and Rradlx Salviae Miltiorrhizae (RSM) to investigate the effects of RSM on the internalization of peroxidized low density lipoprotein (pox-LDL) by using lipid analysis and electron microscopy. Lipid peroxide (LPO) concentrations were increased slightly in the medium after incubation of macrophages with normal LDL (n-LDL), while decreased significantly in the media after incubation of macrophages with pox-LDL. In the three groups with pox-LDL, it could be found that there was a dose-dependent decrease of concentrations of LPO and total cholesterol (TCH) in the two RSM groups, and the decrease in the two RSM groups was much greater than in the group without RSM. RSM accelerated a more decrease of LPO than cholesterol contents in the media containing pox-LDL. The ultrastructural studies also showed that RSM induced the accumulation of lipid droplets in the cytoplasm of mouse peritoneal macrophages. The results suggested that RSM could accelerate the phagocytosis and degradation of pox-LDL by macrophages.展开更多
Injury to mitochondria of macrophages caused by oxidized low density lipoprotein (Ox-LDL) and the role of lipid hydroperoxides (LOOH). lipid and protein in Ox-LDL on the injury were studied by measuring mito-chondrial...Injury to mitochondria of macrophages caused by oxidized low density lipoprotein (Ox-LDL) and the role of lipid hydroperoxides (LOOH). lipid and protein in Ox-LDL on the injury were studied by measuring mito-chondrial membrane potential (MMP) on ACAS570. The results showed that MMP decreased when macrophageswere treated by Ox-LDL. If LOOH in Ox-LDL was pre cleared by ebselen plus GSH. the decreased MMP could be recovered by about 20 %. Lipid moiety alone had no effect on IMP, but protein moiety could cause decrease ofMMP, the extent of the decrease was equivalent to that caused by Ox-LDL in which LOOH was pre-cleared by ebselen plus GSH.展开更多
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...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.展开更多
Emerging data now indicate and address the strong relationship between H. pylori infection and the incidence of Type 2 DM, a growing body of evidence suggests that the infection with H. pylori may be associated with i...Emerging data now indicate and address the strong relationship between H. pylori infection and the incidence of Type 2 DM, a growing body of evidence suggests that the infection with H. pylori may be associated with insulin resistance, chronic inflammation, long-term diabetes complications, and cardiovascular risk factors. The present study was conducted to evaluate the relationship between the infection with Helicobacter pylori and disturbance in Lipid profile in Type 2 Diabetic patients. One hundred and five participants were enrolled, categorized into two groups of H. pylori positive cases and negative controls according to their results of H. pylori IgG antibodies. Subjects in both groups fill the structured questionnaire. Blood samples were drawn for measuring the FBS, 2hr-PP blood sugar, HbA1c, Lipid profile and oxidized LDL. The obtained results were statistically analyzed. The study methodology was approved by the Biomedical Ethics Committee in the Faculty of Medicine, Umm Al-Qura University, Makkah, KSA. 48 cases (45.7%) were diagnosed as H. pylori seropositive and 57 (54.3%) were negative. There is no significant difference in the mean age or mean BMI between the H. pylori negative and positive cases. Glycemic control was similar in the two groups. Total Cholesterol was higher in cases of positive H. pylori compared to negative controls (P < 0.001) and Triglycerides was significantly elevated too (P < 0.005). No significant difference in the levels of HDL-Cholesterol between the two groups, while the mean LDL-Cholesterol was found to be significantly increased in cases of H. pylori positive compared to negative controls (P < 0.001). Oxidized LDL levels in the positive cases was found to be increased significantly (P = 0.001) compared to negative controls. Infection with H. pylori is associated with increased levels of Total Cholesterol, Triglycerides, LDL-C and oxidized LDL in Type 2 Diabetic patients.展开更多
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 capac...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.展开更多
基金supported by National Natural Science Foundation of China(NSFC10572159)supported by "111 Project" entitled "Biomechanics&Tissue Repair Engineering"(No.:B06023)Chongqing Science&Technology Council(CSTC 2006ba5010)
文摘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。
文摘Whereas the close structural homology between human plasminogen and apolipoprotein(a) has been known for a number of years only recent studies have revealed that both proteins carry linked oxidized phospholipids that may modify the function of these proteins. Future studies should provide a better understanding of oxidized phospholipid adducts and the role played by lipoprotein-associated phospholipase A2 for which cleavage specificity has been established when these modified lipids are in a free form.
基金State Key Clinical Specialty Construction Project,China
文摘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.
基金This project was supported by a grant from Provincial Outstanding Youth Program for Henan Province Committee of Sciences and Technology (No. 19972002).
文摘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.
文摘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.
基金supported by grants from the National Nature Science Foundation of China(No.81070190)the Foundation of Natural Sciences of Hubei Province of China(No.2014CFB962)
文摘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.
基金supported by the National Natural Science Foundation of China,No.81971125(to ZYH).
文摘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.
文摘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).
基金Supported by the National Natural Science Foundation of China (No.81470654)Science and Technology Plan of Natural Science Foundation of Shaanxi Province (No.2019SF-047)。
文摘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.
基金supported by the National Natural Science Foundation of China(No.30971244)
文摘Mitofusin2 (Mfn2) plays a pivotal role in the proliferation and apoptosis of vascular smooth muscle cells (VSMCs). The purpose of this study was to investigate the effects of Mfn2 on the traffick- ing of intracellular cholesterol in the foam ceils derived from rat VSMCs (rVSMCs) and also to investigate the effects of Mfn2 on the expression of adenosine triphosphate-binding cassette subfamily A member 1 (ABCA1), adenosine triphosphate-binding cassette subfamily G member 1 (ABCG1) and peroxisome proliferator-activated receptor gamma (PPARy). The rVSMCs were co-cultured with oxi- dized low density lipoprotein (LDL, 80 ~tg/mL) to produce foam cells and cholesterol accumulation in cells. Before oxidized LDL treatment, different titers (20, 40 and 60 pfu/cell) of recombinant adenovirus containing Mfn2 gene (Adv-Mfn2) were added into the culture medium for 24 h to transfect the Mfn2 gene into the rVSMCs. Then the cells were harvested for analyses. The protein expression of Mfn2 was significantly higher in Adv-Mfn2-transfected group than in untransfected group (P〈0.05), and the ex- pression levels significantly increased when the titer of Adv-Mfn2 increased (P〈0.05). At 24 or 48 h af- ter oxidized LDL treatment, rVSMCs became irregular and their nuclei became larger, and their plasma abounded with red lipid droplets. However, the number of red lipid droplets was significantly decreased in Adv-Mfn2-transfected group as compared with untransfected group. At 48 h after oxidized LDL treatment, the intracellular cholesterol in rVSMCs was significantly increased (P〈0.05), but it was sig- nificantly decreased in Adv-Mfn2-transfected group as compared with untransfected group (P〈0.05), and it also significantly decreased when the titer of Adv-Mfn2 increased (P〈0.05). The mRNA and pro- tein expression levels of ABCA1 and ABCG1 were significantly increased in Adv-Mfn2-transfected group as compared with untransfected group (P〈0.05). Though the mRNA and protein expression levels of PPARy was not significantly increased (P〉0.05), the phosporylation levels of PPARy were signifi- cantly decreased in Adv-Mfn2-transfected group as compared with untransfected group (P〈0.05). These results suggest that the transfection of Adv-Mfn2 can significantly reduce intracellular cholesterol in oxidized LDL-induced rVSMCs possibly by decreasing PPAR'/phosporylation and then increasing pro- tein expression levels of ABCAI and ABCG1, which may be helpful to suppress the formation of foam cells.
文摘Objective To investigate the molecular mechanism of atherosclerosis that related to age. Methods Immunohistochemistry staining and Western blot were adopted to determine the nuclear translocation of nuclear factor-kappa B (NF-κB) and expression of platelet-derived growth factor B (PDGF-B) in smooth muscle cells (SMCs) co-cultured with low density lipoprotein (LDL), oxidized LDL (ox-LDL), and ox-LDL+high density lipoprotein (HDL) originated from rats of 2 and 10 months old respectively. Fat stain was used to identify the lipid intake in SMCs. Results The optimal stimulation time of ox-LDL to SMCs was 12 hours. NF-κB intensity increased in most nuclei of SMCs that originated from rats of either 2 or 10 months old co-cultured with ox-LDL. The intensity of NF-κB and the amount of intracellular lipid taken in SMCs were more obvious in cells from 10-month-old rats than from the younger ones. Change of PDGF-B expression in SMCs was not remarkable in each group of rats. Conclusions The 10-month-old rats are more susceptive to ox-LDL than 2-month-old rats in activating nuclear transloca- tion of NF-κB. Maybe this is one of the important reasons contributing to the difference between the older and younger rats on the initiation and development of atherosclerosis lesion. Expression of PDGF-B is not associated with the activity of nuclear translocation of NF-κB.
文摘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.
基金Supported by the Foundation of Hunan Educational Committee (06C692)
文摘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.
文摘Mouse peritoneal macrophages were incubated in DMEM with pox-LDL and Rradlx Salviae Miltiorrhizae (RSM) to investigate the effects of RSM on the internalization of peroxidized low density lipoprotein (pox-LDL) by using lipid analysis and electron microscopy. Lipid peroxide (LPO) concentrations were increased slightly in the medium after incubation of macrophages with normal LDL (n-LDL), while decreased significantly in the media after incubation of macrophages with pox-LDL. In the three groups with pox-LDL, it could be found that there was a dose-dependent decrease of concentrations of LPO and total cholesterol (TCH) in the two RSM groups, and the decrease in the two RSM groups was much greater than in the group without RSM. RSM accelerated a more decrease of LPO than cholesterol contents in the media containing pox-LDL. The ultrastructural studies also showed that RSM induced the accumulation of lipid droplets in the cytoplasm of mouse peritoneal macrophages. The results suggested that RSM could accelerate the phagocytosis and degradation of pox-LDL by macrophages.
文摘Injury to mitochondria of macrophages caused by oxidized low density lipoprotein (Ox-LDL) and the role of lipid hydroperoxides (LOOH). lipid and protein in Ox-LDL on the injury were studied by measuring mito-chondrial membrane potential (MMP) on ACAS570. The results showed that MMP decreased when macrophageswere treated by Ox-LDL. If LOOH in Ox-LDL was pre cleared by ebselen plus GSH. the decreased MMP could be recovered by about 20 %. Lipid moiety alone had no effect on IMP, but protein moiety could cause decrease ofMMP, the extent of the decrease was equivalent to that caused by Ox-LDL in which LOOH was pre-cleared by ebselen plus GSH.
文摘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.
文摘Emerging data now indicate and address the strong relationship between H. pylori infection and the incidence of Type 2 DM, a growing body of evidence suggests that the infection with H. pylori may be associated with insulin resistance, chronic inflammation, long-term diabetes complications, and cardiovascular risk factors. The present study was conducted to evaluate the relationship between the infection with Helicobacter pylori and disturbance in Lipid profile in Type 2 Diabetic patients. One hundred and five participants were enrolled, categorized into two groups of H. pylori positive cases and negative controls according to their results of H. pylori IgG antibodies. Subjects in both groups fill the structured questionnaire. Blood samples were drawn for measuring the FBS, 2hr-PP blood sugar, HbA1c, Lipid profile and oxidized LDL. The obtained results were statistically analyzed. The study methodology was approved by the Biomedical Ethics Committee in the Faculty of Medicine, Umm Al-Qura University, Makkah, KSA. 48 cases (45.7%) were diagnosed as H. pylori seropositive and 57 (54.3%) were negative. There is no significant difference in the mean age or mean BMI between the H. pylori negative and positive cases. Glycemic control was similar in the two groups. Total Cholesterol was higher in cases of positive H. pylori compared to negative controls (P < 0.001) and Triglycerides was significantly elevated too (P < 0.005). No significant difference in the levels of HDL-Cholesterol between the two groups, while the mean LDL-Cholesterol was found to be significantly increased in cases of H. pylori positive compared to negative controls (P < 0.001). Oxidized LDL levels in the positive cases was found to be increased significantly (P = 0.001) compared to negative controls. Infection with H. pylori is associated with increased levels of Total Cholesterol, Triglycerides, LDL-C and oxidized LDL in Type 2 Diabetic patients.
文摘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.