Inhibition Effects of Nippostrongylus brasiliensis and Its Derivatives against Atherosclerosis in ApoE-/- Mice through Anti-Inflammatory Response.

Atherosclerosis (AS) is a dominant and growing cause of death and disability worldwide that involves inflammation from its inception to the emergence of complications. Studies have demonstrated that intervention with helminth infections or derived products could modulate the host immune response and effectively prevent or mitigate the onset and progression of inflammation-related diseases. Therefore, to understand the molecular mechanisms underlying the development of atherosclerosis, we intervened in ApoE-/- mice maintained on a high-fat diet with Nippostrongylus brasiliensis (N. brasiliensis) infection and immunized with its derived products. We found that N. brasiliensis infection and its derived proteins had suitable protective effects both in the initial and progressive stages of atherosclerosis, effectively reducing aortic arch plaque areas and liver lipid contents and downregulating serum LDL levels, which may be associated with the significant upregulation of serum anti-inflammatory cytokines (IL-10 and IL-4) and the down-regulation of proinflammatory cytokines (TNF-α and IFN-γ) in the serum. In conclusion, these data highlighted the effective regulatory role of N. brasiliensis and its derived proteins in the development and progression of atherosclerosis. This could provide a promising new avenue for the prevention and treatment of atherosclerosis.

Atherosclerosis in Different Vascular Locations Unbiasedly Approached with Mouse Genetics.

Atherosclerosis in different vascular locations leads to distinct clinical consequences, such as ischemic stroke and myocardial infarction. Genome-wide association studies in humans revealed that genetic loci responsible for carotid plaque and coronary artery disease were not overlapping, suggesting that distinct genetic pathways might be involved for each location. While elevated plasma cholesterol is a common risk factor, plaque development in different vascular beds is influenced by hemodynamics and intrinsic vascular integrity. Despite the limitation of species differences, mouse models provide platforms for unbiased genetic approaches. Mouse strain differences also indicate that susceptibility to atherosclerosis varies, depending on vascular locations, and that the location specificity is genetically controlled. Quantitative trait loci analyses in mice suggested candidate genes, including Mertk and Stab2, although how each gene affects the location-specific atherosclerosis needs further elucidation. Another unbiased approach of single-cell transcriptome analyses revealed the presence of a small subpopulation of vascular smooth muscle cells (VSMCs), which are "hyper-responsive" to inflammatory stimuli. These cells are likely the previously-reported Sca1+ progenitor cells, which can differentiate into multiple lineages in plaques. Further spatiotemporal analyses of the progenitor cells are necessary, since their distribution pattern might be associated with the location-dependent plaque development.

3D MicroCT spatial and temporal characterization of thoracic aorta perivascular adipose tissue and plaque volumes in the ApoE-/- mouse model.

Perivascular adipose tissue (PVAT) influences vascular function and pathology. We present a protocol using micro-computed tomography (microCT), a novel imaging technique typically used for hard biological tissue, to characterize the temporal and spatial development of aorta PVAT and luminal plaque soft tissue. Apolipoprotein E deficient (ApoE) and C57Bl/6J (control) mice were fed a high fat western diet up to 30 weeks. 3D microCT reconstructions were used to quantify: 1) vascular wall volume, a surrogate measure of remodeling, was greater in ApoE, 2) aorta PVAT volume was reduced in ApoE, 3) plaque volumes increased over time in ApoE, 4) plaque development co-localized with luminal ostia, origins of branching arteries, which traveled through areas of greatest PVAT volume, 5) qualitatively, the same arteries showed evidence of increased tortuosity in ApoE. This study reflects the potential of microCT analyses to assess vascular wall, PVAT and arterial trajectory modifications in relevant animal models. Abbreviations: PVAT: perivascular adipose tissue; ApoE: apolipoprotein E deficient mouse strain; Control: C57Bl/6J mouse strain; PTA: 0.3% phosphotungstic acid; microCT: micro-computed tomography; CV: cardiovascular; CVD: cardiovascular disease; IQR: interquartile range; PPARγ: peroxisome proliferator activated receptor - gamma; VV: vasa vasorum; 3D: three dimensional.

Induction of Diabetes Abolishes the Antithrombotic Effect of Clopidogrel in Apolipoprotein E-Deficient Mice.

Patients with acute coronary syndrome with diabetes mellitus (DM) exhibit an impaired platelet inhibitory response to clopidogrel which is only partially understood. DM was induced by the administration of streptozotocin (STZ) to 9-week-old mice. The antithrombotic effects of clopidogrel (10 mg/kg/d, orally × 5 days) were determined using a FeCl 3 -induced thrombosis model employing wild-type (WT), apolipoprotein E (apoE)-deficient, and diabetic apoE-deficient mice at 21 weeks. Antiplatelet effects were determined using flow cytometry. The antithrombotic effects of clopidogrel were similar in WT and apoE-deficient mice but were attenuated in diabetic apoE-deficient mice with the percent inhibition of thrombus area (µm 2 ) by clopidogrel being 85.5% (WT mice), 75.0% (apoE-deficient mice), and 1.9% (diabetic apoE-deficient mice). The time to first occlusion and lumen stenosis also reflected a significant loss of the antithrombotic effects of clopidogrel in diabetic apoE-deficient mice. Ex vivo platelet activation, which was assessed using ADP-induced expression of activated glycoprotein IIb/IIIa, was completely inhibited by clopidogrel in these three groups of mice. In contrast, the effect of clopidogrel on the ex vivo expression of platelet P-selectin induced by protease-activated receptor 4-activating peptide was diminished in diabetic apoE-deficient mice compared with that in WT and apoE-deficient mice. These data suggest that diabetic apoE-deficient mice may serve as a useful model to better understand the impaired responses to clopidogrel in patients with DM, which may partially reflect a reduction of the effect of clopidogrel on thrombin-induced platelet activation.

A study on retinal angiomatous proliferation and its mechanism in apolipoprotein E-deficient mouse with dyslipidemia / 中华实验眼科杂志

Background Retinal angiomatous proliferation (RAP) is a subtype of neovascular age-related macular degeneration (AMD).There are currently very few studies on RAP.Objective This study was to explore the pathogenic mechanism of RAP in apolipoprotein E-deficient (ApoE-/-) mice with dyslipidemia.Methods Twenty-four 2-month-old SPF ApoE-/-mice were randomly divided into the high fat diet group and the normal diet group,and twelve 2-month-old C57BL/6 mice received the normal diet as controls.A diet with a higher content of fat was given for 4 consecutive months in the high fat diet group,and normal diet was given in the same way in the mice of the normal diet group.The mice were sacrificed at 6 months of age.The expression of vascular endothelial growth factor (VEGF) in the retinal pigment epithelial (RPE) cells,the expression of vascular endothelial growth factor receptor-2 (VEGFR-2) in the outer plexiform layer (OPL),microvascular density (MVD) and microvascular area (MVA) in the OPL were examined by immunohistochemistry and semi-quantitatively by histopathology with the Mias 2000 Imaging Analyzer System.The expression of VEGF protein in the retina was examined by Western blot.Results The MVD in the retinal OPL were (20.67±3.20) and (19.50± 1.87),respectively,in the ApoE-/-mice of the high fat diet group and the normal diet group,which were significantly higher than that (12.50±1.87) of the C57BL/6 normal diet group (all at P＜0.01).MVA in the retinal OPL were (626.49± 120.99) μm2 and (514.06±88.83) μm2 in the ApoE-/-mice of the high fat diet group and the normal diet group,respectively,showing a significant increase in comparison with the (336.52±84.96) μm2 of the C57BL/6 normal diet group (P＜0.01).The staining area of VEGF in RPE cells was (21 048±1849) μm2 in the ApoE-/-mice of the high fat diet group,showing a significant increase in comparison with the (17 116±2023) μm2 of the C57BL/6 normal diet group.However,no significant difference was found in the staining area of VEGF between the ApoE-/-mice with normal diet group and the C57BL/6 normal diet group ([17 854±2967] μm2 vs.[17 116±2023] μm2) (P＞0.05).Significant elevation was also seen in the staining area of VEGFR-2 in the retinal OPL of the ApoE-/-mice of the high fat diet group (12 193±3806)μm2 and the ApoE-/-mice of the normal diet group (11 969± 3616)xm2 compared with C57BL/6 mice of the normal diet group (5387±2225)μm2(all at P＜0.01).The relative expression values (VEGF/β-actin) of VEGF in the retinas were (1.51 ±0.32) and (1.17±0.39) in the ApoE-/-mice of the high fat diet group and the normal diet group,respectively,showing a significant increase in comparison with (0.28±0.14) of the C57BL/6 normal diet group (P＜0.01).Conclusions The expression of VEGF and VEGFR-2 in the retinas increases in the ApoE-/-mouse,which leads to the enlargement of MVD and MVA in the retinal OPL and subsequent RAP occurrence.

The effects of antiproliferative drugs at stenotic area associated with primary atherosclerotic lesions in apoE knockout mouse - Change of vascular remodeling

Apolipoprotein (apo) E deficient mouse can produce reproducible fixed stenotic primary atherosclerotic lesion, which reveals failure to remodel of vascular lumen, in the ascending aorta, external carotid, common carotid, iliac, femoral and popliteal arteries. To evaluate the effect of drugs in regarding to both prevention of primary atherosclerotic lesion and vascular remodeling, a systematic analysis of distribution of atherosclerotic lesions was undertaken in chow-fed, 9-momth-old apo E deficient mice, which was administrated drugs including asprin, methotrexate, probucol, sulodexide, diltiazem, cilazapril, trimetazidine, molsidomine, pentoxiphylline and Ginexin (R) for 7 month from 3 month-old. On gross and microscopic examination, formation of primary atheroscleotic lesions could be delated and/or prevented patially by effets of these drugs. On morphometric examination, failure to remodel forming vascular stenosis could not be seen, though relatively mild atherosclerotic lesion occured at vascular tree. These data suggest that the stenotic process in advanced atherosclerotic vessels can be delayed and/or prevented by several drugs including methotrexate, probucol, sulodexide, diltiazem, cilazapril, trimetazidine, molsidomine, pentoxiphylline and Ginexin (R) in vivo state.