Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) have recently been identified to be closely related to the occurrence and development of atherosclerosis (AS). A growing body of evidence has suggested Chinese medicine takes unique advantages in preventing and treating AS. In this review, the related research progress of AS and LOX-1 has been summarized. And the anti-AS effects of 10 active components of herbal medicine through LOX-1 regulation have been further reviewed. As a potential biomarker and target for intervention in AS, LOX-1 targeted therapy might provide a promising and novel approach to atherosclerotic prevention and treatment.
Humans ; Atherosclerosis ; Scavenger Receptors, Class E/physiology* ; Biomarkers ; Plant Extracts ; Lipoproteins, LDL

BACKGROUNDLipid abnormalities are often complicated by renal dysfunction. 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) are the first-line choice for lowering cholesterol levels. The present study was designed to investigate whether statins could prevent and invert the development of renal injury in cholesterol-fed rabbits and to find the possible mechanism of their effects by detecting gene and protein expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in the renal artery.

METHODSTwenty-four male New Zealand white rabbits were divided into three groups: (1) control group, regular granules chow; (2) HC-diet group, granules chow with 1% cholesterol and 5% lard oil; and (3) fluvastatin group, 1% cholesterol and 5% lard oil diet plus fluvastatin [10 mg.kg(-1).d(-1)]. After 16 weeks, serum total cholesterol (TC), low-density lipoprotein (LDL) and creatinine (Cr) levels were measured. Renal hemodynamics and function, mainly including glomerular filtration rate (GFR) in vivo were quantified using (99m)Tc-DTPA single photon emission computed tomograph ((99m)Tc-DTPA SPECT). The thickness of the renal artery intima was quantitated in HE-stained segments by histomorphometry. Gene expression of LOX-1 in the renal artery was examined by semi-quantitative RT-PCR and its protein expression was evaluated by immunohistochemistry.

RESULTSHigh cholesterol diet induced hypercholesterolemia (HC) complicated by renal dysfunction with increased levels of serum lipid and Cr, decreased GFR and delayed excretion and extensively thickened renal arterial intima in the HC-diet group. Rabbits in the control group showed a minimal LOX-1 expression (mRNA and protein) in the endothelium and neointima of the renal artery. Intimal proliferation of the renal artery in the HC-diet group was associated with a marked increase of LOX-1 expression (protein and mRNA). Treatment with fluvastatin improved renal function, attenuated intimal proliferation of the renal artery and markedly decreased the enhanced LOX-1 expression in the endothelium and neointima of the renal artery in rabbits.

CONCLUSIONSFluvastatin treatment could prevent the development of renal injury in patients with HC and early atherosclerosis (AS). This beneficial effect might be mediated by its pleiotropic effects including a decrease in total cholesterol exposure level and prevention of LOX-1 expression in atherosclerotic arteries.

Animals ; Cholesterol ; blood ; Creatinine ; blood ; Fatty Acids, Monounsaturated ; pharmacology ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; pharmacology ; Hypercholesterolemia ; drug therapy ; metabolism ; pathology ; Immunohistochemistry ; Indoles ; pharmacology ; Kidney ; drug effects ; pathology ; Male ; RNA, Messenger ; analysis ; Rabbits ; Receptors, LDL ; analysis ; genetics ; Receptors, Oxidized LDL ; Scavenger Receptors, Class E ; Tomography, Emission-Computed, Single-Photon

OBJECTIVETo investigate the effects of oxidized low-density lipoprotein receptor 1 (LOX-1) on secretion of adhesive molecules mediated by ox-LDL in human umbilical endothelial cells (HUVECs).

METHODSHUVECs with different concentration of ox-LDL (0, 10, 20, 50, 100 microg/ml) were incubated for 24 h, or HUVECs were pretreated with 250 microg/ml poly (I) or 250 microg/ml carrageenan for 2 h and then incubated with 50 microg/ml ox-LDL for another 24 h. Expression of LOX-1 was determined by realtime RT-PCR and Western blot. mRNA and protein of ICAM-1, VCAM-1 and E-selectin were examined by RT-PCR and Western blot respectively.

RESULTSIncubation of HUVECs with ox-LDL (10-100 microg/ml) enhanced the expressions of LOX-1, ICAM-1 and E-selectin in a concentration-dependent manner (P < 0.01). On the contrary, ox-LDL did not affect the expression of VCAM-1 by HUVECs. The expression of LOX-1, ICAM-1 and E-selectin induced by ox-LDL were reduced in HUVECs pretreated with 250 microg/ml poly (I) or 250 microg/ml carrageenan for 2 h and then incubated with 50 microg/ml ox-LDL for 24 h. This showed that both poly (I) and carrageenan obviously decreased the expression of LOX-1, ICAM-1 and E-selectin induced by ox-LDL.

CONCLUSIONox-LDL may upregulate the expression of LOX-1, ICAM-1 and E-selectin, and LOX-1 blocker may partly inhibit this upregulation. The results suggest that the expression of inflammatory molecules induced by ox-LDL in HUVECs is mediated by LOX-1.

Cell Adhesion ; Cell Adhesion Molecules ; Cells, Cultured ; E-Selectin ; metabolism ; Endothelial Cells ; metabolism ; Endothelium, Vascular ; metabolism ; Humans ; Intercellular Adhesion Molecule-1 ; metabolism ; Lipoproteins, LDL ; biosynthesis ; RNA, Messenger ; metabolism ; Receptors, Oxidized LDL ; metabolism ; Scavenger Receptors, Class E ; metabolism ; Umbilical Veins ; cytology ; Vascular Cell Adhesion Molecule-1 ; metabolism

AIMTo develop a fluorescence polarization-based high throughput screening and identify ligands for human Lectin-like oxidized low-density lipoprotein receptor-1 (hLOX-1).

METHODSSequential ultracentrifugation at 4 degrees C from normolipidemic fasting volunteers to obtain low density lipoprotein (LDL), which was modified by CuSO4 (5 micromol x L(-1)) at 37 degrees C for 24 h. The assay was based on the interaction between receptor and ligand, and hLOX-1 was labeled by FITC and bound to its specific ligand, oxLDL. Different reaction time and DMSO concentration were optimized to determine the stability and tolerance of fluorescence polarization (FP) assay. 3 200 compounds were screened in black 384-well microplate by FP-based competitive displacement assay, at excitation filter of 485 nm and emission filter of 530 nm. Z' was used to assess the assay quality.

RESULTSThe FP-based HTS was formatted in a 384-well microplate with a Z' factor of 0. 75, and three active compounds for hLOX-1 were identified with IC50 below 40 micromol x L(-1) from total 3 200 compounds.

CONCLUSIONThe results indicated that the fluorescence polarization assay is stable, sensitive, reproducible and well suited for high throughput screening efforts.

Binding, Competitive ; Drug Evaluation, Preclinical ; methods ; Fluorescence Polarization ; methods ; Humans ; Ligands ; Lipoproteins, LDL ; metabolism ; Scavenger Receptors, Class E ; metabolism

OBJECTIVETo study the changes of lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) expression in the autologous vein grafts and vein graft atherosclerotic lesions.

METHODSThirty New Zealand white rabbits were randomly assigned to normal control group (rabbits fed with normal diet, n = 10), vein graft group (autologous external jugular vein grafting to common carotid artery and fed with normal diet, n = 10) or vein graft plus high-lipid diet group (autologous vein graft and fed with high-lipid diet, n = 10) for 12 weeks. LOX-1 expressions in the grafts were examined by immunohistochemistry and semi-quantitative reverse transcription-PCR. The relationships between serum total cholesterol level, intimal thickness and LOX-1 expression were also investigated.

RESULTSLOX-1 expression was low in the endothelium of external jugular veins in the normal control group and significantly increased in the endothelium and neointima of vein grafts in the vein graft group (0.31 +/- 0.14 vs. 0.09 +/- 0.04, P < 0.01) and which was further increased in the endothelium and atherosclerotic lesions in the vein graft plus high-lipid diet group (0.93 +/- 0.34 vs. 0.31 +/- 0.14, P < 0.01). LOX-1 expression in the atherosclerotic lesions was located both in endothelial cells and foam cells and the expression was most prominent in endothelial cells. LOX-1 expression and intimal thickness were positively related to serum total cholesterol level (P = 0.00 and 0.02) and the partial correlation coefficient was 0.78 and 0.42, respectively.

CONCLUSIONSLOX-1 expression is increased in endothelium and neointima of autologous vein grafts of rabbits. Hypercholesterolemia upregulates LOX-1 expression in vein graft atherosclerosis. Thus, LOX-1 might play an important role in the pathogenesis of vein graft atherosclerosis.

Animals ; Atherosclerosis ; metabolism ; pathology ; Disease Models, Animal ; Graft Occlusion, Vascular ; metabolism ; pathology ; Lipoproteins, LDL ; blood ; Male ; Rabbits ; Scavenger Receptors, Class E ; metabolism ; Transplantation, Autologous ; Veins ; transplantation

OBJECTIVETo explore action mechanism of electroacupuncture for coronary atherosclerotic heart disease (CHD) in order to provide experimental support for clinical acupoint selection.

METHODSAmong sixty clean-grade healthy male Wistar rats, twenty-four cases were randomly selected as a normal control group and an electroacupuncture (EA) preconditioning group, 12 cases in each one. Then rats in the EA preconditioning group and the rest 36 rats were fed with high fat diet for 12 weeks to duplicate the CHD model. When the models were successfully established, the rats were randomly divided into a model control group, an EA group and a medication group, 12 cases in each one. EA was applied with Hwa-to SDZ-IV apparatus in the EA preconditioning group at "Neiguan" (PC 6) and "Xinshu" (BL 15), 1 mA in current intensity, 2 Hz in frequency, 30 min per times, once every other day for 14 weeks. When model was established, the same acupoint and method was used in the EA group for 2 weeks while intragastric administration of atorvastatin mixed suspension, 0.25 mg/kg, once a day, was applied in the medication group for 2 weeks. The content of oxidized low-density lipoprotein (oxLDL) in the serum was tested by double antibody enzyme-linked immunosorbent assay (ELISA) while content of lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) in coronary arterial tissue was test by western blot method. Expression of LOX-1 mRNA was tested by fluorogenic quantitative polymerase chain reaction (PCR).

RESULTSAfter model was duplicated successfully, the content of oxLDL in the serum and the expression of LOX-1 and its mRNA in coronary arterial tissue in the model control group were increased significantly compared with those in the normal control group (all P < 0.01). Compared with the model control group, the content of oxLDL in the serum and the expression of LOX-1 and its mRNA in coronary arterial tissue in the EA preconditioning group, EA group and medication group were significantly reduced (all P < 0.01).

CONCLUSIONThe electroacupuncture at "Neiguan" (PC 6) and "Xinshu" (BL 15) could effectively reduce the content of oxLDL in the serum and expression of LOX-1 and its mRAN in coronary arterial tissue in CHD rats. The oxidative modificatory low-density lipoprotein and its specific receptor system could be one of the ways to prevention and treatment of acupuncture for CHD.

Animals ; Coronary Disease ; genetics ; metabolism ; therapy ; Disease Models, Animal ; Electroacupuncture ; Humans ; Lipoproteins, LDL ; genetics ; metabolism ; Male ; Rats ; Rats, Wistar ; Scavenger Receptors, Class E ; genetics ; metabolism

OBJECTIVE: To investigate the effect of miR-590-5p on the expression of lectin-like oxidized low density lipoprotein receptor 1 (LOX-1) in apoptotic human umbilical vein endothelial cells (HUVECs) induced by ox-LDL, and to explore the role of miR-590-5p in modulating HUVECs apoptosis. METHODS: HUVECs were exposed to ox-LDL (50 μg/mL) for 0 to 48 h. Apoptosis was detected by Annexin V-FITC stain and was distinguished from necrosis by propidium iodide (PI) staining. The relative expression level of miR-590-5p in HUVECs was analyzed using real-time quantitative PCR (RT-qPCR). HUVECs were transfected with miR-590-5p mimics or miRNA mimics control followed by 50 μg/mL ox-LDL stimulation for 48 h. LOX-1 mRNA and protein were measured by RT-qPCR and Western blot, and apoptosis in HUVECs was analyzed by flow ctyometry after Annexin V-FITC/PI double stain. RESULTS: Incubation of HUVECs with 50 μg/mL ox-LDL for 0 to 48 h resulted in a time-dependent induction of apoptotic cell death and down-regulation of miR-590-5p. Transfection of miR-590-5p mimics suppressed LOX-1 expression at both mRNA and protein levels, leading to a reduction of ox-LDL-induced apoptosis in HUVECs. CONCLUSION MiR-590-5p protects endothelial cells from ox-LDL induced apoptosis by inhibiting the expression of LOX-1.
Apoptosis ; genetics ; Cells, Cultured ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; Lipoproteins, LDL ; pharmacology ; MicroRNAs ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Scavenger Receptors, Class E ; genetics ; metabolism ; Transfection

OBJECTIVEThe present study was designed to investigate the preventive and therapeutic effect of 3-hydroxy-3-methylglutanyl coenzyme A (HMG-CoA) reductase inhibitor fluvastatin on the development of atherosclerosis (AS) in immature rabbits and its possible mechanism by detecting the expression level of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in the abdominal aorta.

METHODSA model of hypercholesterolemia (HC) was established by high-cholesterol diet and 24 immature rabbits were divided randomly and equally into control group, HC-diet group and fluvastatin group. At the beginning of the study and after 12 weeks, the body height (BH) and body weight (BW) of the rabbits were measured and their body mass index (BMI) was calculated. At the end of 12 weeks, serum total cholesterol (TC) and low-density lipoprotein (LDL) levels were examined. The intima-medial thickness of the abdominal aorta (aIMT) was measured by using non-invasive high-resolution (14 MHz) B-mode ultrasound imaging. Histological changes in abdominal arteries were studied by H&E-staining and histomorphometric analysis. The gene expression of LOX-1 in abdominal aorta was evaluated by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and its protein expression was examined by immunohistochemistry.

RESULTSHigh cholesterol diet induced hypercholesterolemia and early AS in immature rabbits. In HC-diet group serum TC and LDL levels in rabbits elevated. B mode echocardiography showed that aIMT was thickened and pathomorphology indicated that extensive aortic intima (I) and intima and media (I + M) became thickened and the ratio of the area of intima to media (S(I)/S(M)) was increased. Aortic intimal proliferation in HC-diet group was associated with a marked increase in LOX-1 expression (protein and mRNA) in endothelium and neointima of the abdominal aorta. Treatment with fluvastatin at a dosage of 10 mg/(kg.d) deduced serum lipid, attenuated artery intimal proliferation and markedly decreased the enhanced LOX-1 expression level in endothelium and neointima in immature rabbits. There were no significant differences of BH, BW or BMI among the three groups.

CONCLUSIONSThese findings suggested that early treatment with fluvastatin not only induced a significant regression of arterial lesions of HC and early AS in immature rabbits, but also had a crucial endothelial protective effect by down-regulating LOX-1 expression level in atherosclerotic arteries in early AS.

Animals ; Aorta, Abdominal ; diagnostic imaging ; pathology ; Arteries ; metabolism ; pathology ; Atherosclerosis ; drug therapy ; metabolism ; Cholesterol, Dietary ; Cholesterol, LDL ; blood ; Echocardiography ; Fatty Acids, Monounsaturated ; pharmacology ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; pharmacology ; Hypercholesterolemia ; drug therapy ; metabolism ; Indoles ; pharmacology ; Rabbits ; Scavenger Receptors, Class E ; metabolism

OBJECTIVETo investigate whether oxidized low-density lipoprotein (oxLDL) affects the survival and activity of endothelial progenitor cell (EPC) and whether the effects are mediated by lectin-like oxidized low-density lipoprotein receptor (LOX-1).

METHODSCD34+ cells isolated from human umbilical blood were cultured in endothelial cell growth medium-2 (EGM-2). After 14 days of culture, some EPCs were stimulated with 10, 25, 50 microg/ml of oxLDL for 48 hours; some were preincubated with LOX-1 mAb, a blocking antibody of LOX-1, for 24 hours, then exposed to 50 microg/ml oxLDL for 48 hours; others without any further treatment were used as control. The survival of EPC and the ability of adhesion, migration, and tube formation were examined. The levels of LOX-1 protein and mRNA expression were also assayed.

RESULTSIncubation with oxLDL at concentrations of 25 microg/ml or higher resulted in a dose-dependent increase of EPC apoptosis [25 microg/ml: (15.8 +/- 1.1.0%, 50 microg/ml: (18.8 +/- 2.0)% versus control: (9.0 +/- 1.2)%; P < 0.05]. Treated with oxLDL led to a significantly reduced migratry rate [25 microg/ml: (5.7 +/- 1.0)%, 50 microg/ml: (5.1 +/- 0.8)% versus control: (9.5 +/- 0.8)%; P < 0.05]. EPC treated with oxLDL showed a dose-dependent reduction of adhesion to fibronectin (25 Kg/ml: 33 +/- 2, 50 microg/ml: 30 +/- 3 versus control: 37 +/- 5; P < 0.05). Treatment with oxLDL impaired the in vitro vasculogenesis ability of EPCs. The total length of the tube structures in each photograph was decreased [25 microg/ml: (2.9 +/- 0.5) mm, 50 microg/ml: (1.8 +/- 0.5) mm versus control: (5.0 +/- 0.6) mm; P < 0.05]. The tube structure was severely disrupted, resulting in an incomplete and sparse tube network. However, all the detrimental effects on EPC were attenuated by pretreatment of EPC with LOX-1 mAb. In addition, Western blot analysis revealed that oxLDL increased LOX-1 protein expression from 100% to (172 +/- 8)% at a dose of 50 microg/ml. Furthermore, oxLDL caused an increase in LOX-1 mRNA expression from 100% to (174 +/- 39)% at a dose of 50 microig/ml.

CONCLUSIONOxLDL can directly inhibit EPC survival and activity and these effects are mediated by its receptor, LOX-1.

Antigens, CD34 ; metabolism ; Apoptosis ; Cell Adhesion ; Cell Movement ; Cell Survival ; Cells, Cultured ; Endothelial Cells ; drug effects ; physiology ; Fetal Blood ; cytology ; Humans ; Lipoproteins, LDL ; pharmacology ; physiology ; Neovascularization, Physiologic ; Scavenger Receptors, Class E ; biosynthesis ; physiology ; Stem Cells ; drug effects ; physiology

OBJECTIVETo investigate the effect of Antrodia cinnamomea on gene expression related to aortal endothelial injury of rats with hyperlipidemia.

METHODFifty SD rats were randomly divided into five groups: the normal control group (NG), the model group (MG), the antrodia cinnamomea groups of low, middle and high doses (AC-LG, AC-MG, AC-HG, 250, 500, 1 000 mg x kg(-1)). The rats were fed with high-fat diets to establish the hyperlipidemia model. After the drug administration for 10 weeks, their serum lipid, SOD, MDA and ox-LDL, LOX-1, P38 MAPK and NF-kappaB mRNA and protein expression were respectively determined, and the aortal endothelial injury was observed under electron microscope.

RESULTIn the model group, the contents of TC, TG and LDL-C significant increased (P < 0.01), whereas the content of HDL-C significant decreased (P < 0.01). Compared with the model group, both the AC-M group and the AC-H group showed reduction in endothelial injury and significant decrease in the content of TC, TG and LDL-C (P < 0.05 or P < 0.01). The content of HDL-C increased, but with no significant difference. SOD activity in serum remarkably increased (P < 0.05 or P < 0.01), MDA and ox-LDL levels dramatically decreased (P < 0.05 or P < 0.01).

CONCLUSIONA. cinnamomea can alleviate endothelial lipid injury by inhibiting the expressions of LOX-1, P38MAPK and NF-kappaB in aorta and better protect aortal endothelial cells from oxidative lipid injury.

Animals ; Antrodia ; chemistry ; Aorta ; drug effects ; metabolism ; ultrastructure ; Atherosclerosis ; blood ; genetics ; prevention & control ; Biological Products ; pharmacology ; Cholesterol ; blood ; Cholesterol, HDL ; blood ; Cholesterol, LDL ; blood ; Endothelium, Vascular ; drug effects ; metabolism ; pathology ; Enzyme-Linked Immunosorbent Assay ; Gene Expression ; drug effects ; Hyperlipidemias ; blood ; genetics ; prevention & control ; Lipoproteins, LDL ; blood ; Male ; Malondialdehyde ; blood ; Microscopy, Electron ; NF-kappa B ; blood ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Scavenger Receptors, Class E ; blood ; genetics ; metabolism ; Superoxide Dismutase ; blood ; Triglycerides ; blood ; p38 Mitogen-Activated Protein Kinases ; blood ; genetics ; metabolism