CD36 is a membrane glycoprotein that is present on various types of cells, including monocytes, macrophages, microvascular endothelial cells, adipocytes and platelets. Macrophage CD36 participates in atherosclerotic arterial lesion formation through its interaction with oxidized low-density lipoprotein (oxLDL), which triggers signaling cascades for inflammatory responses. CD36 functions in oxLDL uptake and foam cell formation, which is the initial critical stage of atherosclerosis. In addition, oxLDL via CD36 inhibits macrophage migration, which may be a macrophage-trapping mechanism in atherosclerotic lesions. The role of CD36 was examined in in vitro studies and in vivo experiments, which investigated various functions of CD36 in atherosclerosis and revealed that CD36 deficiency reduces atherosclerotic lesion formation. Platelet CD36 also promotes atherosclerotic inflammatory processes and is involved in thrombus formation after atherosclerotic plaque rupture. Because CD36 is an essential component of atherosclerosis, defining the function of CD36 and its corresponding signaling pathway may lead to a new treatment strategy for atherosclerosis.
Animals ; Antigens, CD36/chemistry/genetics/*metabolism ; Atherosclerosis/*metabolism/pathology ; Humans ; Macrophages/metabolism/pathology ; Plaque, Atherosclerotic/*metabolism/pathology

OBJECTIVEAtherosclerosis is an inflammatory process that results in complex lesions or plaques that protrude into the arterial lumen. Carotid atherosclerotic plaque rupture, with distal atheromatous debris embolization, causes cerebrovascular events. This review aimed to explore research progress on the risk factors and outcomes of human carotid atherosclerotic plaques, and the molecular and cellular mechanisms of human carotid atherosclerotic plaque vulnerability for therapeutic intervention.

DATA SOURCESWe searched the PubMed database for recently published research articles up to June 2016, with the key words of "risk factors", "outcomes", "blood components", "molecular mechanisms", "cellular mechanisms", and "human carotid atherosclerotic plaques".

STUDY SELECTIONThe articles, regarding the latest developments related to the risk factors and outcomes, atherosclerotic plaque composition, blood components, and consequences of human carotid atherosclerotic plaques, and the molecular and cellular mechanisms of human carotid atherosclerotic plaque vulnerability for therapeutic intervention, were selected.

RESULTSThis review described the latest researches regarding the interactive effects of both traditional and novel risk factors for human carotid atherosclerotic plaques, novel insights into human carotid atherosclerotic plaque composition and blood components, and consequences of human carotid atherosclerotic plaque.

CONCLUSIONCarotid plaque biology and serologic biomarkers of vulnerability can be used to predict the risk of cerebrovascular events. Furthermore, plaque composition, rather than lesion burden, seems to most predict rupture and subsequent thrombosis.

Biomarkers ; blood ; Carotid Stenosis ; blood ; epidemiology ; metabolism ; pathology ; Humans ; Plaque, Atherosclerotic ; blood ; complications ; metabolism ; pathology ; Risk Factors

Atherosclerosis is an inflammatory disease as well as a lipid disorder. Atherosclerotic plaque formed in vessel walls may cause ischemia, and the rupture of vulnerable plaque may result in fatal events, like myocardial infarction or stroke. Because morphological imaging has limitations in diagnosing vulnerable plaque, molecular imaging has been developed, in particular, the use of nuclear imaging probes. Molecular imaging targets various aspects of vulnerable plaque, such as inflammatory cell accumulation, endothelial activation, proteolysis, neoangiogenesis, hypoxia, apoptosis, and calcification. Many preclinical and clinical studies have been conducted with various imaging probes and some of them have exhibited promising results. Despite some limitations in imaging technology, molecular imaging is expected to be used both in the research and clinical fields as imaging instruments become more advanced.
Atherosclerosis/*diagnosis/pathology/radiography ; Endothelial Cells/metabolism ; Humans ; Inflammation/pathology ; Lipoproteins, LDL/metabolism ; Macrophages/immunology/metabolism ; Plaque, Atherosclerotic ; Positron-Emission Tomography ; Tomography, Emission-Computed, Single-Photon

OBJECTIVETo explore the association of fractalkine (FKN) and CD11c expressions oncommon carotid artery atherosclerotic plaques from apoE(-/-) mice with the severity of atherosclerotic lesions.

METHODSTotally 24 apoE(-/-) mice were divided into two groups and fed on a high-fat diet or a normal diet for 12 weeks. Then the blood lipids as well as the plaque area and vascular stenosis rate of the common carotid artery were measured to evaluate the severity of atherosclerotic lesions of the animals. Moreover, immunohistochemical staining was performed to examine the levels of FKN and CD11c expression.

RESULTSThe plaque areas and vascular stenosis rates of the common carotid artery in the experimental group were remarkably larger than those in control group (about 4-fold and 2-fold, respectively). The level of FKN expression in the experimental group was 2 times of that in the control group (P<0.05), and the number of CD11c (+) cells in the plaques in the experimental group was about 4 times of than in the control group (P<0.05).

CONCLUSIONThe expressions of chemokine and FKN remarkably increase in apoE (-/-) atherosclerotic plaques, suggesting that chemokine and FKN may paly important roles in the development of atherosclerosis.

Animals ; Atherosclerosis ; metabolism ; pathology ; CD11 Antigens ; metabolism ; Chemokine CX3CL1 ; metabolism ; Diet, High-Fat ; Disease Models, Animal ; Mice ; Mice, Knockout ; Plaque, Atherosclerotic ; pathology

BACKGROUNDAutophagy has been found to be involved in animal and cell models of atherosclerosis, but to date, it lacks general observation in human atherosclerotic plaques. Here, we investigated autophagy in smooth muscle cells (SMCs), endothelial cells (ECs), and macrophages in human atherosclerotic plaques via transmission electron microscopy (TEM), western blotting, and immunohistochemistry analysis.

METHODSThe histopathologic morphology of these plaques was observed via hematoxylin and eosin staining. The ultrastructural morphology of the SMCs, ECs, and macrophages in these plaques was observed via TEM. The localization of microtubule-associated protein 1 light chain 3 (MAP1-LC3), a relatively special maker of autophagy, in plaques was observed by double fluorescent immunochemistry and western blotting.

RESULTSAll of these human atherosclerotic plaques were considered advanced and unstable in histologically observation. By double fluorescent immunochemistry, the expression of LC3-II increased in the SMCs of the fibrous cap, the macrophages, and the microvascular ECs of the plaque shoulders. The protein level of LC3-II by western blotting significantly increased in plaques compared with normal controls. In addition, TEM observation of plaques revealed certain features of autophagy in SMCs, ECs, and macrophages including the formation of myelin figures, vacuolization, and the accumulation of inclusions in the cytosol. These results indicate that autophagy is activated in SMCs, ECs, and macrophages in human advanced atherosclerotic plaques.

CONCLUSIONSOur study is to demonstrate the existence of autophagy in human atherosclerotic plaques by different methods, which may contribute to the development of pharmacological approaches to stabilize vulnerable and rupture-prone lesions.

Atherosclerosis ; metabolism ; physiopathology ; Autophagy ; physiology ; Endothelial Cells ; pathology ; Humans ; In Vitro Techniques ; Microscopy, Electron, Transmission ; Microtubule-Associated Proteins ; metabolism ; Myocytes, Smooth Muscle ; pathology ; Plaque, Atherosclerotic ; metabolism ; physiopathology ; ultrastructure

The present study aimed to investigate the protective effect of S-propargyl-cysteine (SPRC) on atherosclerosis progression in mice. A mouse model of vulnerable atherosclerotic plaque was created in ApoE^-/- mice by carotid artery tandem stenosis (TS) combined with a Western diet. Macrophotography, lipid profiles, and inflammatory markers were measured to evaluate the antiatherosclerotic effects of SPRC compared to atorvastatin as a control. Histopathological analysis was performed to assess the plaque stability. To explore the protective mechanism of SPRC, human umbilical vein endothelial cells (HUVECs) were cultured in vitro and challenged with oxidized low-density lipoprotein (ox-LDL). Cell viability was determined with a Cell Counting Kit-8 (CCK-8). Endothelial nitric oxide synthase (eNOS) phosphorylation and mRNA expression were detected by Western blot and RT-qPCR respectively. The results showed that the lesion area quantified by en face photographs of the aortic arch and carotid artery was significantly less, plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were reduced, plaque collagen content was increased and matrix metalloproteinase-9 (MMP-9) was decreased in 80 mg/kg per day SPRC-treated mice compared with model mice. These findings support the role of SPRC in plaque stabilization. In vitro studies revealed that 100 μmol/L SPRC increased the cell viability and the phosphorylation level of eNOS after ox-LDL challenge. These results suggest that SPRC delays the progression of atherosclerosis and enhances plaque stability. The protective effect may be at least partially related to the increased phosphorylation of eNOS in endothelial cells.
Animals ; Humans ; Mice ; Atherosclerosis ; Cholesterol/metabolism* ; Cysteine/pharmacology* ; Human Umbilical Vein Endothelial Cells/metabolism* ; Lipoproteins, LDL/pharmacology* ; Nitric Oxide Synthase Type III/metabolism* ; Phosphorylation ; Plaque, Atherosclerotic/pathology*

OBJECTIVETo study the expression of COX-2 and pregnancy associate plasma protein A (PAPP-A) in coronary arteries and their relationship with acute coronary syndrome.

METHODSTwenty-one autopsy cases with acute coronary syndrome encountered during the period from 2002 to 2007 were enrolled into the study. Another 21 autopsy cases without evidence of acute coronary syndrome were used as the controls. The right and left coronary arteries of each group were dissected, embedded and processed as paraffin sections. Immunohistochemical study for CD68 and alpha-actin was performed to highlight the presence of macrophages and smooth muscle cells, respectively. The expression of COX-2 and PAPP-A was evaluated.

RESULTSIn the acute coronary syndrome group, COX-2 was localized mainly in the cytoplasm of endothelial cells, macrophages and smooth muscle cells. COX-2 expression in the cytoplasm of smooth muscle cells (28.60%) was significantly higher than that in the control group (4.76%, chi(2) = 14.13, P< 0.05). There was a positive correlation on COX-2 and PAPP-A expression in smooth muscle cells of the media layer of coronary arteries in acute coronary syndrome group (r = 0.88, P < 0.05). The expression of PAPP-A in smooth muscle cells of the media layer in coronary arteries not associated with plaque formation, was higher than that when there were atherosclerotic plaques (chi(2) = 10.36, P < 0.05).

CONCLUSIONIn coronary arteries, COX-2 and PAPP-A play certain roles in the pathogenesis of acute coronary syndrome.

Acute Coronary Syndrome ; metabolism ; pathology ; Adult ; Aged ; Autopsy ; Coronary Vessels ; metabolism ; pathology ; Cyclooxygenase 2 ; metabolism ; Female ; Humans ; Middle Aged ; Myocytes, Smooth Muscle ; metabolism ; Plaque, Atherosclerotic ; metabolism ; Pregnancy ; Pregnancy-Associated Plasma Protein-A ; metabolism ; Young Adult

OBJECTIVETo observe the effect of Huxin Formula on expressions of the chief reverse cholesterol transport (RCT) associated genes, caveolin-1 and scavenger receptor-BI (SR-BI) in ApoE-gene knockout [ApoE (-/-)] mice.

METHODSThirty ApoE (-/-) mice of 4-6 weeks old were randomly divided into three groups (A-C). After being fed with high-fat diet for 16 weeks, they were treated with HXF (1 mL/100 g), pravachol (0.3 mg/100 g), and saline in equal volume respectively for 16 weeks successively; in addition, a blank group was set up with 10 C57BL/6J mice of 6-week old received 16-week high-fat feeding and saline treatment. Animals were sacrificed at the termination of the experiment, their paraffin sections of aortic tissue were used to measure the size of plaque, expressions of cavolin-1 and SR-BI were detected by immunological histochemical method.

RESULTSAs compared with the blank group, levels of caveolin-1 and SR-BI were increased in Groups A and B (P<0.01); but the increase in Group A was more significant than that in Group B (P<0.05). The plaque/aorta area ratio decreased significantly in Groups A and B, but showed insignificant difference between the two groups.

CONCLUSIONHXF could obviously increase the expressions of RCT associated genes, caveolin-1 and SR-BI, promote the RCT process, so as to reduce the formation of aorta atherosclerotic plaque in ApoE (-/-) mice.

Animals ; Aorta ; drug effects ; pathology ; Apolipoproteins E ; deficiency ; genetics ; Atherosclerosis ; pathology ; Biological Transport ; drug effects ; Caveolin 1 ; metabolism ; Cholesterol ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Female ; Immunohistochemistry ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Plaque, Atherosclerotic ; pathology ; Receptors, Scavenger ; metabolism

BACKGROUNDVulnerable plaques play an important role in the onset of sudden cardiac events and strokes. How to stabilize vulnerable plaques is still a challenge to medical science. Alprostadil is a biologically active substance with strong activity on vessel. Our study assessed the stabilizing effects of an alprostadil liposome microsphere preparation (ALMP) on vulnerable plaques in the brachiocephalic artery of apolipoprotein E (Apo E) knockout mice.

METHODSSeventy-two male Apo E-knockout mice were fed a high-fat diet beginning at eight weeks of age. At week 17, they were divided randomly into groups for treatment with a high dose (3.6 µg×kg(-1)×d(-1)) or low dose (1.8 µg×kg(-1)×d(-1)) of an ALMP, or 0.2 ml/d normal saline (control group). The drug was administered using a micro-capsule pump. Twenty weeks after drug administration, pathological changes in the vulnerable plaques within the brachiocephalic artery were assessed, and levels of anti-mouse monocyte/macrophage monoclonal antibody (MOMA-2) and superoxide anions in the plaques were detected using immunofluorescence. The soluble intercellular adhesion molecule-1 (ICAM-1) expression was measured by ELISA, and the expression of matrix metalloproteinase-9 (MMP-9) and CD40 mRNA was measured using RT-PCR. Thrombospindin-1 (TSP-1) expression was detected using Western blotting.

RESULTSCompared with the control group, ALMP treatment significantly reduced the plaque area in the brachiocephalic artery (P < 0.01), significantly lowered the contents of the lipid core (P < 0.01), significantly reduced the number of ruptured fibrous caps (P < 0.05), and increased the thickness of the fibrous cap and significantly reduced the incidence of intra-plaque hemorrhage (P < 0.05). ALMP treatment significantly reduced the expression of MOMA-2, superoxide anion, MMP-9, ICAM-1 and CD40 in the plaques (P < 0.01), decreased plasma ICAM-1 expression (P < 0.01), and increased the expression of TSP-1.

CONCLUSIONSTreatment with ALMP can stabilize vulnerable plaques by inhibiting inflammation.

Alprostadil ; chemistry ; therapeutic use ; Animals ; Enzyme-Linked Immunosorbent Assay ; Inflammation ; drug therapy ; metabolism ; pathology ; Intercellular Adhesion Molecule-1 ; metabolism ; Liposomes ; chemistry ; Male ; Mice ; Mice, Knockout ; Microscopy, Fluorescence ; Microspheres ; Plaque, Atherosclerotic ; drug therapy ; metabolism ; pathology ; Polymerase Chain Reaction

OBJECTIVE: To explore the expression of CyPA and CD147 in rabbit models of vulnerable carotid atherosclerotic plaque and the therapeutic effect of atorvastatin.
 METHODS: Twenty-four male New Zealand rabbits were randomly divided into 3 groups. Eight rabbits were served as a normal diet group (Group A), and the remaining 16 rabbits underwent balloon-induced endothelial injury in the right carotid artery and thereafter were fed on high-cholesterol diet (1% cholesterol) for 12 weeks, then they were divided into 2 groups: a AS group (Group B), an atorvastatin group [Group C, 2.5 mg/(kg.d)]. 4 weeks later, plaque disrupture was triggered by China Russell's viper venom and histamine. Serum levels of TC, TG, LDL-C and HDL-C were measured at different timepoint. The damaged carotid arteries were collected to undergo pathological examination. The macrophage, expression of CyPA and CD147 were detected by immuno-histochemical analysis, and the mRNA levels of CyPA and CD147 were examined by reverse transcription polymerase chain reaction (RT-PCR).
 RESULTS: Compared with the Group A, the serum levels of TC and LDL-c in the Group B and Group C were significantly increased (all P<0.01). Compared with the Group B, the serum levels of TC and LDL-c in the Group C were reduced significantly after atorvastatin intervention for 4 weeks (all P<0.01). The plaques disruption and thrombosis occurred in 4 out of the 6 rabbits in the Group B, while only 1 rabbit demonstrated plaques disruption and thrombosis in the Group C. Compared with the Group B, the levels of CyPA, CD147 and macrophage in carotid atherosclerotic plaque in the Group C were decreased significantly (all P<0.01).
 CONCLUSION The up-regulation of CyPA and CD147 may be involved in pathogenesis of vulnerable carotid atherosclerotic plaque. Atorvastatin could stabilize the plaque through inhibiting the CyPA and CD147 expression.
Animals ; Atorvastatin ; pharmacology ; Basigin ; metabolism ; Carotid Artery, Common ; pathology ; Cholesterol ; blood ; Cholesterol, Dietary ; administration & dosage ; Cyclophilin A ; metabolism ; Macrophages ; cytology ; Male ; Plaque, Atherosclerotic ; drug therapy ; metabolism ; Rabbits ; Random Allocation ; Thrombosis ; pathology ; Triglycerides ; blood