Abstract 466: Therapeutic Immunization with an Antiglycosaminoglycan Antibody Reduces Atherosclerotic Lesion Progression in Apolipoprotein E-Deficient Mice

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Roger Sarduy ◽  
Victor Brito ◽  
Yosdel Soto ◽  
Livan Delgado-Roche ◽  
Tania Griñán ◽  
...  

Subendothelial retention of apoB-containing lipoproteins by interaction with glycosaminoglycan-side chains of proteoglycans is considered the key initiating step of atherogenesis. Previously, we characterized the antiatherogenic properties of the chimeric mAb chP3R99, which binds sulfated GAG, inhibits LDL-chondroitin sulfate (CS) association, and abrogates LDL oxidation in vitro and in vivo. In preventive settings, rabbits and mice immunized with this mAb showed reduced atherosclerotic lesions, related with the induction of anti-chondroitin sulfate (CS) antibodies. Now we focus in define the immunization schedule which can induce in apolipoprotein E-deficient (apoE-/-) the highest anti-CS antibody response and the greater reduction of atherosclerotic lesion progression. ApoE - / - mice (6-8 wk. old) fed a chow diet received four s.c. injections of 50 or 200 μg of chP3R99 mAb. Autologous antichondroitin sulfate (CS) antibody response was evaluated in sera by ELISA. Mice who were immunized with 200 μg generated a significant higher response against CS than the ones that received 50 μg. Then, to evaluate the association of the induction of a higher anti-CS response in the atherosclerotic lesion progression, apoE-/- mice fed with a high-fat high-cholesterol diet from 4 to 18 wk. of age, received 6 doses of 50, 100 or 200 μg of the mAb starting when 5% of the aortic area was covered by lesions. Animals were sacrificed and aortas isolated to determine the presence of lesions by histologic studies. Mean aortic lesion areas of 50 and 100 μg chP3R99-treated mice were significant reduced by ~40% in comparison with mice treated with an isotype-matched control mAb. In contrast, 62% reduction in total lesion area was observed in mice treated with 200 μg of chP3R99. Again, there was an association between the level of anti-CS antibody response and the reduction of atherosclerotic lesion progression. In conclusion, this study demonstrated the dose dependence of the anti-CS antibody response and its relationship with the arresting of the atherosclerotic progression induced by chP3R99 mAb immunization. Our results also supports the potential use of this antiglycosaminoglycan antibody-based immunotherapy as a novel approach to target advanced atherosclerosis

2007 ◽  
Vol 293 (3) ◽  
pp. C865-C873 ◽  
Author(s):  
Tomoya Yamashita ◽  
Seinosuke Kawashima ◽  
Tetsuaki Hirase ◽  
Masakazu Shinohara ◽  
Tomofumi Takaya ◽  
...  

Atherosclerosis is a complex chronic inflammatory disease in which macrophages play a critical role, and the intervention of the inflammatory process in atherogenesis could be a therapeutic strategy. In this study, we investigated the efficacy of xenogenic macrophage immunization on the atherosclerotic lesion formation in a model of murine atherosclerosis. Apolipoprotein E knockout (apoE-KO) mice were repeatedly immunized with formaldehyde-fixed cultured human macrophages (phorbol ester-stimulated THP-1 cells), using human serum albumin as a control protein or HepG2 cells as human control cells, once a week for four consecutive weeks. The vehicle phosphate-buffered saline was injected in the nonimmunized controls. THP-1 immunization induced antibodies that are immunoreactive with mouse macrophages. Although the plasma lipid levels were unchanged by the immunization, the atherosclerotic lesion area in the aortic root was significantly reduced by >50% in 16-wk-old THP-1-immunized apoE-KO mice compared with that in control mice. THP-1 immunization reduced in vivo macrophage infiltration, reduced in vitro macrophage adhesion, and changed cytokine production by macrophages to the antiatherogenic phenotype. Xenogenic macrophage immunization protects against the development of atherosclerosis in apoE-KO mice by modulating macrophage function in which antibodies induced by the immunization are likely to be involved. This method is a novel and potentially useful cell-mediated immune therapeutic technique against atherosclerosis.


Author(s):  
Puttaswamy Mukthamba ◽  
Krishnapura Srinivasan

AbstractDietary fenugreek seeds (Fenugreek seeds, garlic, and their combination were included along with a high-cholesterol diet for 8 weeks.Iron-induced oxidation of LDL in vivo was considerably lowered by dietary fenugreek and garlic. The extent of copper-induced oxidation of isolated LDL in vitro was also significantly lesser in fenugreek-fed or fenugreek+garlic-fed rats. Anodic electrophoretic mobility of the oxidized LDL on agarose gel in case of spice-fed animals was decreased and hence consistent with the observed protective influence on LDL oxidation. Dietary fenugreek, garlic, and their combination significantly lowered lipid peroxide levels in plasma, liver, and heart in iron (II)-administered rats. The results suggest that these two dietary spices have protective effect on LDL oxidation under normal situation as well as in hypercholesterolemic situation. The protective effect of the combination of dietary fenugreek and garlic on LDL oxidation both in vivo and in vitro was greater than that of the individual spices.The protective effect of dietary fenugreek and garlic on LDL oxidation both in vivo and in vitro as evidenced in the present study is suggestive of their cardioprotective potential since LDL oxidation is a key factor in the arteriosclerotic process.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Xingxing Li ◽  
Chunyan Su ◽  
Zhibo Jiang ◽  
Yuxin Yang ◽  
Yue Zhang ◽  
...  

AbstractTrimethylamine-N-oxide (TMAO), a derivative from the gut microbiota metabolite trimethylamine (TMA), has been identified to be an independent risk factor for promoting atherosclerosis. Evidences suggest that berberine (BBR) could be used to treat obesity, diabetes and atherosclerosis, however, its mechanism is not clear mainly because of its poor oral bioavailability. Here, we show that BBR attenuated TMA/TMAO production in the C57BL/6J and ApoE KO mice fed with choline-supplemented chow diet, and mitigated atherosclerotic lesion areas in ApoE KO mice. Inhibition of TMA/TMAO production by BBR-modulated gut microbiota was proved by a single-dose administration of d9-choline in vivo. Metagenomic analysis of cecal contents demonstrated that BBR altered gut microbiota composition, microbiome functionality, and cutC/cntA gene abundance. Furthermore, BBR was shown to inhibit choline-to-TMA conversion in TMA-producing bacteria in vitro and in gut microbial consortium from fecal samples of choline-fed mice and human volunteers, and the result was confirmed by transplantation of TMA-producing bacteria in mice. These results offer new insights into the mechanisms responsible for the anti-atherosclerosis effects of BBR, which inhibits commensal microbial TMA production via gut microbiota remodeling.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Amar Bahadur Singh ◽  
Jingwen Liu

Abstract TRIB1 is a GWAS locus associated with plasma cholesterol and triglycerides (TG) levels. In mice, liver-specific overexpression of TRIB1 lowers plasma lipid levels. Berberine (BBR) is a natural lipid lowering drug that reduces plasma LDL-cholesterol (LDL-C), total cholesterol (TC) and TG in hyperlipidemic patients and in mice by mechanisms involving upregulation of hepatic LDL receptor (LDLR). Here, we demonstrated that BBR treatment reduced plasma LDL-C, TC and TG in LDLR wildtype (WT) mice fed a high fat and high cholesterol diet and it only lowered TG in LDLR WT mice fed a normal chow diet. In hypercholesterolemic LDLR deficient mice (Ldlr−/−), BBR treatment reduced plasma TG levels by 51% compared to the vehicle control without affecting plasma cholesterol levels. Hepatic gene expression analysis revealed that Trib1 mRNA levels were significantly elevated by BBR treatment in all three mouse models and increases of Trib1 mRNA expression were associated with reduced expression of lipogenic genes including Cebpa, Acc1 and Scd1. In vitro studies further demonstrate that BBR induces TRIB1 mRNA expression by a transcriptional mechanism via ERK signaling pathway. These new findings warrant future in vivo studies to determine the causal role of Trib1 in BBR-mediated TG lowering independent of LDLR regulation.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
KyeongJin Kim ◽  
Jin Ku Kang ◽  
Young Hoon Jung ◽  
Sang Bae Lee ◽  
Raffaela Rametta ◽  
...  

AbstractIncreased adiposity confers risk for systemic insulin resistance and type 2 diabetes (T2D), but mechanisms underlying this pathogenic inter-organ crosstalk are incompletely understood. We find PHLPP2 (PH domain and leucine rich repeat protein phosphatase 2), recently identified as the Akt Ser473 phosphatase, to be increased in adipocytes from obese mice. To identify the functional consequence of increased adipocyte PHLPP2 in obese mice, we generated adipocyte-specific PHLPP2 knockout (A-PHLPP2) mice. A-PHLPP2 mice show normal adiposity and glucose metabolism when fed a normal chow diet, but reduced adiposity and improved whole-body glucose tolerance as compared to Cre- controls with high-fat diet (HFD) feeding. Notably, HFD-fed A-PHLPP2 mice show increased HSL phosphorylation, leading to increased lipolysis in vitro and in vivo. Mobilized adipocyte fatty acids are oxidized, leading to increased peroxisome proliferator-activated receptor alpha (PPARα)-dependent adiponectin secretion, which in turn increases hepatic fatty acid oxidation to ameliorate obesity-induced fatty liver. Consistently, adipose PHLPP2 expression is negatively correlated with serum adiponectin levels in obese humans. Overall, these data implicate an adipocyte PHLPP2-HSL-PPARα signaling axis to regulate systemic glucose and lipid homeostasis, and suggest that excess adipocyte PHLPP2 explains decreased adiponectin secretion and downstream metabolic consequence in obesity.


2009 ◽  
Vol 83 (23) ◽  
pp. 12355-12367 ◽  
Author(s):  
Mohammed Rafii-El-Idrissi Benhnia ◽  
Megan M. McCausland ◽  
John Laudenslager ◽  
Steven W. Granger ◽  
Sandra Rickert ◽  
...  

ABSTRACT Antibodies against the extracellular virion (EV or EEV) form of vaccinia virus are an important component of protective immunity in animal models and likely contribute to the protection of immunized humans against poxviruses. Using fully human monoclonal antibodies (MAbs), we now have shown that the protective attributes of the human anti-B5 antibody response to the smallpox vaccine (vaccinia virus) are heavily dependent on effector functions. By switching Fc domains of a single MAb, we have definitively shown that neutralization in vitro—and protection in vivo in a mouse model—by the human anti-B5 immunoglobulin G MAbs is isotype dependent, thereby demonstrating that efficient protection by these antibodies is not simply dependent on binding an appropriate vaccinia virion antigen with high affinity but in fact requires antibody effector function. The complement components C3 and C1q, but not C5, were required for neutralization. We also have demonstrated that human MAbs against B5 can potently direct complement-dependent cytotoxicity of vaccinia virus-infected cells. Each of these results was then extended to the polyclonal human antibody response to the smallpox vaccine. A model is proposed to explain the mechanism of EV neutralization. Altogether these findings enhance our understanding of the central protective activities of smallpox vaccine-elicited antibodies in immunized humans.


2003 ◽  
Vol 177 (1) ◽  
pp. 137-146 ◽  
Author(s):  
L Oziol ◽  
P Faure ◽  
N Bertrand ◽  
P Chomard

Oxidized low density lipoproteins (LDL) are highly suspected of initiating the atherosclerosis process. Thyroid hormones and structural analogues have been reported to protect LDL from lipid peroxidation induced by Cu2+ or the free radical generator 2,2'-azobis-'2-amidinopropane' dihydrochloride in vitro. We have examined the effects of thyroid compounds on macrophage-induced LDL oxidation. Human monocyte-derived macrophages (differentiated U937 cells) were incubated for 24 h with LDL and different concentrations (0-20 microM) of 3,5,3'-triiodo-l -thyronine (T3), 3,5,3',5'-tetraiodo-L-thyronine (T4), 3,3',5'-tri-iodo-l -thyronine (rT3), the T3 acetic derivative (3,5,3'-tri-iodothyroacetic acid; TA3) or L-thyronine (T0) (experiment 1). Cells were also preincubated for 24 h with 1 or 10 microM of the compounds, washed twice, then incubated again for 24 h with LDL (experiment 2). Oxidation was evaluated by measurement of thiobarbituric acid-reactive substances (TBARS) and cell viability by lactate deshydrogenase release. In experiment 1, T0 had no effect, whereas the other compounds decreased LDL TBARS production, but T3 and TA3 were less active than T4 and rT3 (IC50: 11.0 +/- 2.6 and 8.1 +/- 0.8 vs 1.4 +/- 0.5 and 0.9 +/- 0.3 microM respectively). In experiment 2, the compounds at 1 microM had no effect; at 10 microM, T3 and rT3 slightly reduced LDL TBARS production, whereas TA3 and T4 inhibited it by about 50% and 70% respectively. TBARS released by the cells were also highly decreased by T3, T4, rT3 and TA3 in experiment 1, but only by T3 (30%) and T4 (70%) in experiment 2. Cell viability was not affected by the compounds except slightly by TA3 at 10 microM. The data suggested that the physico-chemical antioxidant capacity of thyroid compounds was modulated by their action on the intracellular redox systems of macrophage. Overall cellular effects of T3 led to a reduction of its antioxidant capacity whereas those of T4 increased it. Thus T4 might protect LDL against cellular oxidation in vivo more than T3.


2019 ◽  
Vol 133 (11) ◽  
pp. 1215-1228 ◽  
Author(s):  
Yu Sun ◽  
Juan Guan ◽  
Yunfeng Hou ◽  
Fei Xue ◽  
Wei Huang ◽  
...  

Abstract Background: Although junctional adhesion molecule-like protein (JAML) has recently been implicated in leukocyte recruitment during inflammation and wound repair, its role in atherosclerosis remains to be elucidated. Methods and results: First, we showed that JAML was strongly expressed in atherosclerotic plaques of cardiovascular patients. Similar results were obtained with atherosclerotic plaques of ApoE−/− mice. Co-immunofluorescence staining showed that JAML was mainly expressed in macrophages. Enhanced expression of JAML in cultured macrophages was observed following exposure of the cells to oxLDL. The functional role of JAML in atherosclerosis and macrophages function was assessed by interference of JAML with shRNA in vivo and siRNA in vitro. Silencing of JAML in mice significantly attenuated atherosclerotic lesion formation, reduced necrotic core area, increased plaque fibrous cap thickness, decreased macrophages content and inflammation. In addition, histological staining showed that JAML deficiency promoted plaques to stable phenotype. In vitro, JAML siRNA treatment lowered the expression of inflammatory cytokines in macrophages treated with oxLDL. The mechanism by which JAML mediated the inflammatory responses may be related to the ERK/NF-κB activation. Conclusions: Our results demonstrated that therapeutic drugs which antagonize the function of JAML may be a potentially effective approach to attenuate atherogenesis and enhance plaque stability.


Author(s):  
Uma Narayanamurthy ◽  
Anandhi M. ◽  
Manimekalai K.

Background: Hyperlipidemia or Dyslipidemia is the major cause of atherosclerosis1 and associated conditions. Low levels of high-density-lipoprotein cholesterol (HDL-C) are the major causes of increased atherogenic risk 1. Aggressive cholesterol reduction in patients with atherosclerotic disease is now the standard of care2. In addition to life style modification, patients with risk factors need lipid lowering drug therapy. The drugs available now do not reduce LDL oxidation, and oxidative stress associated with hyperlipidemia. In recent years, antioxidants have been subjected to epidemiological studies4 that have related their consumption to a reduction in the incidence of oxidative damage related diseases.Methods: Hypercholesterolemia was induced in rats by administration of high cholesterol diet for 30 days in standard rat chow diet. Rats were divided into four groups of six each. Group-I and II with intake of normal diet and High cholesterol diet respectively. Group III and IV are given high cholesterol diet along with Lutein 50mg/kg and Atorvastatin 5mg/kg orally once daily respectively. At the end of 30 days animals were subjected to overnight fasting. Blood samples were drawn by retro-orbital puncture for biochemical analysis. The animals were sacrificed after thiopentone injection and liver and aorta were dissected out and processed for histopathological study and biochemical analysis.Results: Lutein treated group showed even more significant reduction in TBARS levels than the normal control group and Atorvastatin treated group. The efficacy of Lutein in slowing down the atherosclerosis and fatty infiltration of liver is proved in this study.Conclusions: Hence the present study had shown significant hypolipidemic, antiatherogenic and antioxidant effect of Luetin in Hyperlipidemic rats. 


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