Abstract 17163: Nox4 Deletion Attenuates Age-Associated Vascular Inflammation and Atherosclerosis Burden in Hyperlipidemic Mice by Modulating Macrophage Phenotype

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_1) ◽  
Author(s):  
Aleksandr E Vendrov ◽  
Andrey Lozhkin ◽  
Nageswara R Madamanchi ◽  
Marschall S Runge

Introduction: Increased vascular reactive oxygen species (ROS) levels and chronic inflammation are hallmarks of vascular aging. We previously reported that expression of NOX4 NADPH oxidase increases with age in mouse and human arteries and correlates with inflammatory cytokine secretion and atherosclerotic lesion progression. Hypothesis: To determine whether NOX4 promotes atherosclerosis in aging, we assessed vascular inflammation and atherosclerosis burden in Nox4 -/- / Apoe -/- and Apoe -/- mice. Results: Aortic atherosclerotic lesion area was not different between 5-month old (young) Nox4 -/- / Apoe -/- and Apoe -/- mice fed a Western diet for 3 months. Lesion area increased significantly in 16-month old (aged) compared with young mice but was 51% lower in Nox 4 -/- / Apoe -/- versus Apoe -/- mice (n=12, P <0.0001). Immunofluorescence analysis of aorta transverse sections showed 30% lower ROS levels and significantly reduced expression of inflammatory cytokines - CCL2 and IL6 - in atherosclerotic lesions of aged Nox4 -/- / Apoe -/- versus Apoe -/- mice. Flow cytometry analysis of atherosclerotic aortas showed significantly higher number of CD11b + macrophages in the lesions of aged Apoe -/- versus Nox4 -/- /Apoe -/- mice. However, the number of M1 pro-inflammatory macrophages (CD38 + ) was not different, whereas percentage of M2 macrophages (Egr2 + ) was significantly higher in aged Nox4 -/- Apoe -/- versus Apoe -/- mice (46% vs. 33%, respectively). In addition, Nox4 deletion increased the ratio of M2/M1 macrophages in the atherosclerotic aortas from aged Apoe -/- mice (0.56 and 0.43 in Nox 4 -/- / Apoe -/- and Apoe -/- , respectively). Macrophages isolated from Nox4 -/- mice showed lower number of M1 cells after IFNγ+LPS treatment and higher number of M2 cells after IL4 treatment versus macrophages from the wild-type. Furthermore, wild-type macrophages showed significantly higher secreted IL1β levels after IFNγ+LPS treatment versus macrophages from Nox4 -/- mice. Conclusions: These data suggest that increased vascular NOX4 levels in aged Apoe -/- mice promote a proinflammatory environment, enhancing plaque macrophage accumulation and skewing polarization to M1 phenotype resulting in inflammasome activation and atherosclerotic lesion expansion.

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Lin Zhu ◽  
Patricia G Yancey ◽  
Lei Ding ◽  
John L Blakemore ◽  
Youmin Zhang ◽  
...  

Atherosclerosis regression is characterized by egress of macrophages out of the artery wall. We have previously shown that macrophages lacking low-density receptor related protein 1 (MFLRP1-/-) are pro-inflammatory and lead to increased lesion formation in apoE-/- mice. To study the role of macrophage inflammation during atherosclerosis regression, bone marrow from four different types of mice (wild-type, MFLRP1-/-, apoE-/- and apoE-/-/ MFLRP1-/-) was transplanted into apoE-/- recipient mice who had been fed a Western-type diet for 12 weeks. ApoE-/- recipient mice transplanted with apoE-/- bone marrow were sacrificed 2 weeks post-BMT for determination of baseline aortic atherosclerosis. After 8 weeks on chow diet, cholesterol levels were normalized in mice reconstituted with wild-type (WT) and MFLRP1-/- bone marrow (157± 36 mg/dl and 136 ± 33 mg/dl, respectively), and significantly lowered in mice with apoE-/- (302±33 mg/dl) or apoE-/-/ MFLRP1-/- (294±52 mg/dl) macrophages compared to baseline (387±34 mg/dl). Total atherosclerotic lesion area in the aortic root decreased by 15% in mice receiving WT macrophages, and decreased by an additional 10% in mice transplanted with LRP1 deficient macrophages (p<0.05 compared to WT). Similarly, mice reconstituted with apoE-/-/ MFLRP1-/- bone marrow had 15% (p < 0.01) smaller lesion size than mice receiving apoE-/- marrow. The lesion area positive for CD68 was significantly smaller in MFLRP1-/- mice compared to WT mice, and in apoE-/-/ MFLRP1-/- mice compared to apoE-/- mice. The ratio of necrotic to total lesion area was significantly lowered by WT and LRP1-/- macrophages, and was also reduced in recipients of apoE-/-/MFLRP1-/- compared to apoE-/- bone marrow. Here we demonstrate that absence of LRP1 in macrophages, which is known to cause pro-inflammatory changes, promotes atherosclerosis regression. Our study supports the novel idea that pro-inflammatory macrophages efficiently egress from the plaque in a regressive environment caused by switching from a high-fat to a chow diet. This observation sets the stage for a change in paradigm on how to target inflammation for prevention of atherosclerotic cardiovascular events.


Endocrinology ◽  
2010 ◽  
Vol 151 (11) ◽  
pp. 5428-5437 ◽  
Author(s):  
Johan Bourghardt ◽  
Anna S. K. Wilhelmson ◽  
Camilla Alexanderson ◽  
Karel De Gendt ◽  
Guido Verhoeven ◽  
...  

The atheroprotective effect of testosterone is thought to require aromatization of testosterone to estradiol, but no study has adequately addressed the role of the androgen receptor (AR), the major pathway for the physiological effects of testosterone. We used AR knockout (ARKO) mice on apolipoprotein E-deficient background to study the role of the AR in testosterone atheroprotection in male mice. Because ARKO mice are testosterone deficient, we sham operated or orchiectomized (Orx) the mice before puberty, and Orx mice were supplemented with placebo or a physiological testosterone dose. From 8 to 16 wk of age, the mice consumed a high-fat diet. In the aortic root, ARKO mice showed increased atherosclerotic lesion area (+80%, P &lt; 0.05). Compared with placebo, testosterone reduced lesion area both in Orx wild-type (WT) mice (by 50%, P &lt; 0.001) and ARKO mice (by 24%, P &lt; 0.05). However, lesion area was larger in testosterone-supplemented ARKO compared with testosterone-supplemented WT mice (+57%, P &lt; 0.05). In WT mice, testosterone reduced the presence of a necrotic core in the plaque (80% among placebo-treated vs. 12% among testosterone-treated mice; P &lt; 0.05), whereas there was no significant effect in ARKO mice (P = 0.20). In conclusion, ARKO mice on apolipoprotein E-deficient background display accelerated atherosclerosis. Testosterone treatment reduced atherosclerosis in both WT and ARKO mice. However, the effect on lesion area and complexity was more pronounced in WT than in ARKO mice, and lesion area was larger in ARKO mice even after testosterone supplementation. These results are consistent with an AR-dependent as well as an AR-independent component of testosterone atheroprotection in male mice.


2021 ◽  
Author(s):  
Emmanuel Opoku ◽  
Cynthia Alicia Traughber ◽  
David Zhang ◽  
Amanda J Iacano ◽  
Mariam Khan ◽  
...  

Nlrp3 inflammasome is activated in advanced human atherosclerotic plaques. Gasdermin D (GsdmD) serves as a final executor of Nlrp3 inflammasome activity, by generating membrane pores for the release of mature Interleukin-1beta (IL-b). Inflammation dampens reverse cholesterol transport (RCT) and promotes atherogenesis, while anti-IL-1b; antibodies were shown to reduce cardiovascular disease in humans. Though Nlrp3/IL-1b; nexus is an emerging atherogenic pathway, the direct role of GsdmD in atherosclerosis is not yet clear. Here, we used in-vivo Nlrp3 inflammasome activation to show that the GsdmD-/- mice release ~80% less IL-1b; vs WT mice. The GsdmD-/- macrophages were more resistant to Nlrp3 inflammasome mediated reduction in cholesterol efflux, showing ~26% decrease vs. ~60% reduction in WT macrophages. GsdmD expression in macrophages exacerbated foam cell formation in an IL-1b; dependent fashion. The GsdmD-/- mice were resistance to Nlrp3 inflammasome mediated defect in RCT, with ~32% reduction in plasma RCT vs. ~ 57% reduction in WT mice, ~ 17% reduction in RCT to liver vs. 42% in WT mice, and ~ 37% decrease in RCT to feces vs. ~ 61% in WT mice. The LDLr anti-sense oligonucleotides (ASO) induced hyperlipidemic mouse model showed role of GsdmD in promoting atherosclerosis. The GsdmD-/- mice exhibit ~42% decreased atherosclerotic lesion area in females and ~33% decreased lesion area in males vs. WT mice. The atherosclerotic plaque-bearing WT mice showed the presence of cleaved N-terminal fragment of GsdmD, indicating cleavage of GsdmD during atherosclerosis. Our data show that GsdmD mediates inflammation-induced defect in RCT and promotes atherosclerosis.


Blood ◽  
2003 ◽  
Vol 101 (7) ◽  
pp. 2661-2666 ◽  
Author(s):  
Peter C. Burger ◽  
Denisa D. Wagner

P-selectin is an adhesion molecule expressed on activated platelets and endothelium. It is known to play an important role in atherosclerosis. P-selectin also circulates in plasma in a soluble form (sP-selectin), which induces procoagulant microparticle formation. We investigated the role of platelet versus endothelial P-selectin in generating sP-selectin and in the formation of atherosclerotic lesions in the apolipoprotein E (apoE)–deficient mouse model. For this we transplanted apoE−/−P-selectin−/− and apoE−/−P-selectin+/+ lethally irradiated mice with bone marrow of either genotype. Seven months after transplantation, we determined from the chimeric animals that the majority of circulating sP-selectin was of endothelial origin. Thus, in atherosclerosis, the procoagulant sP-selectin reflects endothelial rather than platelet activation. We found that endothelial P-selectin was crucial for the promotion of atherosclerotic lesion growth because in its absence only relatively small lesions developed. However, platelet P-selectin also contributed to the lesion development because lesions in wild-type recipients receiving transplants with wild-type platelets were 30% larger than those receiving P-selectin-deficient platelets (P < .008) and were more frequently calcified (80% versus 44%). In comparison with P-selectin wild-type animals, absence of either endothelial or platelet P-selectin inhibited migration of smooth muscle cells into the lesion. Thus, in addition to endothelium, platelets and their P-selectin also actively promote advanced atherosclerotic lesion development.


2009 ◽  
Vol 206 (10) ◽  
pp. 2067-2077 ◽  
Author(s):  
Soraya Taleb ◽  
Mélissa Romain ◽  
Bhama Ramkhelawon ◽  
Catherine Uyttenhove ◽  
Gerard Pasterkamp ◽  
...  

Atherosclerosis is an inflammatory vascular disease responsible for the first cause of mortality worldwide. Recent studies have clearly highlighted the critical role of the immunoinflammatory balance in the modulation of disease development and progression. However, the immunoregulatory pathways that control atherosclerosis remain largely unknown. We show that loss of suppressor of cytokine signaling (SOCS) 3 in T cells increases both interleukin (IL)-17 and IL-10 production, induces an antiinflammatory macrophage phenotype, and leads to unexpected IL-17–dependent reduction in lesion development and vascular inflammation. In vivo administration of IL-17 reduces endothelial vascular cell adhesion molecule–1 expression and vascular T cell infiltration, and significantly limits atherosclerotic lesion development. In contrast, overexpression of SOCS3 in T cells reduces IL-17 and accelerates atherosclerosis. We also show that in human lesions, increased levels of signal transducer and activator of transcription (STAT) 3 phosphorylation and IL-17 are associated with a stable plaque phenotype. These results identify novel SOCS3-controlled IL-17 regulatory pathways in atherosclerosis and may have important implications for the understanding of the increased susceptibility to vascular inflammation in patients with dominant-negative STAT3 mutations and defective Th17 cell differentiation.


2017 ◽  
Vol 114 (13) ◽  
pp. E2766-E2775 ◽  
Author(s):  
Yaw Asare ◽  
Miriam Ommer ◽  
Florence. A. Azombo ◽  
Setareh Alampour-Rajabi ◽  
Marieke Sternkopf ◽  
...  

Constitutive photomorphogenesis 9 (COP9) signalosome 5 (CSN5), an isopeptidase that removes neural precursor cell-expressed, developmentally down-regulated 8 (NEDD8) moieties from cullins (thus termed “deNEDDylase”) and a subunit of the cullin-RING E3 ligase-regulating COP9 signalosome complex, attenuates proinflammatory NF-κB signaling. We previously showed that CSN5 is up-regulated in human atherosclerotic arteries. Here, we investigated the role of CSN5 in atherogenesis in vivo by using mice with myeloid-specific Csn5 deletion. Genetic deletion of Csn5 in Apoe−/− mice markedly exacerbated atherosclerotic lesion formation. This was broadly observed in aortic root, arch, and total aorta of male mice, whereas the effect was less pronounced and site-specific in females. Mechanistically, Csn5 KO potentiated NF-κB signaling and proinflammatory cytokine expression in macrophages, whereas HIF-1α levels were reduced. Inversely, inhibition of NEDDylation by MLN4924 blocked proinflammatory gene expression and NF-κB activation while enhancing HIF-1α levels and the expression of M2 marker Arginase 1 in inflammatory-elicited macrophages. MLN4924 further attenuated the expression of chemokines and adhesion molecules in endothelial cells and reduced NF-κB activation and monocyte arrest on activated endothelium in vitro. In vivo, MLN4924 reduced LPS-induced inflammation, favored an antiinflammatory macrophage phenotype, and decreased the progression of early atherosclerotic lesions in mice. On the contrary, MLN4924 treatment increased neutrophil and monocyte counts in blood and had no net effect on the progression of more advanced lesions. Our data show that CSN5 is atheroprotective. We conclude that MLN4924 may be useful in preventing early atherogenesis, whereas selectively promoting CSN5-mediated deNEDDylation may be beneficial in all stages of atherosclerosis.


2008 ◽  
Vol 101 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Cynthia M. Gallaher ◽  
Daniel D. Gallaher

Dried plums are a fruit high in pectin with substantial antioxidant activity. Previous studies in rats and man indicate that dried plums or plum fibre lower liver and plasma cholesterol, respectively. The apoE-deficient mouse, which develops atherosclerotic lesions rapidly when fed cholesterol, was used to determine the ability of dried plums to reduce atherosclerosis. Diets containing 0·15 % cholesterol and either 0 (B+C), 4·75 % (Lo DP) or 9·5 % (Hi DP) dried plum powder were fed for 5 months. An additional group fed the basal diet without cholesterol (B − C) was included as a negative control. Arterial trees were dissected, stained to visualize lesions, and lesion area was quantitated by imaging software. Urinary thiobarbituric acid-reactive substances (TBARS) excretion and serum amyloid P-component (SAP) were measured as indicators of oxidative stress and inflammation, respectively. Final serum cholesterol was significantly increased and serum TAG decreased in the B+C group and dried plum groups relative to the B − C group. Percentage arterial tree atherosclerotic lesion area was significantly lower in the B − C and Lo DP groups compared to the B+C group (P < 0·05), with a trend for a difference between the B+C and Hi DP groups (P = 0·075). SAP concentration was significantly lower in the B − C and Lo DP groups with the Hi DP group trending lower than the B+C group. Urinary TBARS excretion did not differ among the groups. These results suggest that consuming dried plums may help slow the development of atherosclerosis.


Author(s):  
Emmanuel Opoku ◽  
Cynthia Alicia Traughber ◽  
David Zhang ◽  
Amanda J. Iacano ◽  
Mariam Khan ◽  
...  

Activation of inflammasomes, such as Nlrp3 and AIM2, can exacerbate atherosclerosis in mice and humans. Gasdermin D (GsdmD) serves as a final executor of inflammasome activity, by generating membrane pores for the release of mature Interleukin-1beta (IL-1β). Inflammation dampens reverse cholesterol transport (RCT) and promotes atherogenesis, while anti-IL-1β antibodies were shown to reduce cardiovascular disease in humans. Though Nlrp3/AIM2 and IL-1β nexus is an emerging atherogenic pathway, the direct role of GsdmD in atherosclerosis is not yet fully clear. Here, we used in vivo Nlrp3 inflammasome activation to show that the GsdmD–/– mice release ∼80% less IL-1β vs. Wild type (WT) mice. The GsdmD–/– macrophages were more resistant to Nlrp3 inflammasome mediated reduction in cholesterol efflux, showing ∼26% decrease vs. ∼60% reduction in WT macrophages. GsdmD expression in macrophages exacerbated foam cell formation in an IL-1β dependent fashion. The GsdmD–/– mice were resistant to Nlrp3 inflammasome mediated defect in RCT, with ∼32% reduction in plasma RCT vs. ∼57% reduction in WT mice, ∼17% reduction in RCT to liver vs. 42% in WT mice, and ∼37% decrease in RCT to feces vs. ∼61% in WT mice. The LDLr antisense oligonucleotides (ASO) induced hyperlipidemic mouse model showed the role of GsdmD in promoting atherosclerosis. The GsdmD–/– mice exhibit ∼42% decreased atherosclerotic lesion area in females and ∼33% decreased lesion area in males vs. WT mice. The atherosclerotic plaque-bearing sections stained positive for the cleaved N-terminal fragment of GsdmD, indicating cleavage of GsdmD in atherosclerotic plaques. Our data show that GsdmD mediates inflammation-induced defects in RCT and promotes atherosclerosis.


Open Medicine ◽  
2010 ◽  
Vol 5 (3) ◽  
pp. 280-291
Author(s):  
Zbyněk Tonar ◽  
Dagmar Bobková ◽  
Kirsti Witter ◽  
Vít Matějka ◽  
Jana Havlíčková ◽  
...  

AbstractSyngeneic transplantation of murine aorta segments with advanced atherosclerotic lesions in defined recipients is a valuable model for regression studies. To date, this model has not been used to study the regression of initial atherosclerotic lesions. The aim of this study was to evaluate a microsurgical technique of syngeneic heterotopic transplantation of the thoracic aorta of young apolipoprotein E-deficient (ApoE-/-) mice to the abdominal aorta of wild-type recipients. Stereological quantification methods were tested in order to assess changes in structure and volume of the aortic wall including the involvement of immune cells in changes of the atherosclerotic lesions. The animals were euthanised one month after surgery and histological analysis including stereological quantification of changes in both the grafts and adjacent aorta segments was performed. The overall survival rate of the recipients was 62.5%. No regression of initial atherosclerotic lesion was achieved and neointima formation and elastin degradation prevailed in all transplanted specimens. The volume of the arteriosclerotic lesions was higher (p<0.001) and elastin length density was lower (p<0.001) in transplanted ApoE-/- samples as compared to adjacent segments. In transplanted grafts, T- and B-lymphocytes, macrophages and neutrophilic granulocytes formed non-random clusters within the vessel wall and they were colocalised with the sutures. The reproducibility of the promising regression model was derogated in young mice by the striking dependence of the results upon the operation technique. Stereological assessment has proven to be accurate, correct and reproducible; it has provided us with robust quantitative estimates, which can be achieved with a reasonable effort.


2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Heidi K Stoute ◽  
Daniel Venegas-Pino ◽  
Kaley J Veerman ◽  
Geoff H Werstuck

Introduction: The complications of diabetes have traditionally been categorized as micro- or macrovasculature in nature. Individuals with diabetes are at an increased risk of macrovascular complications, including cardiovascular disease and stroke, and also suffer from microvascular disorders including retinopathy, nephropathy and neuropathy. There is increasing evidence these micro- and macrovascular conditions may be linked. Our objective is to determine if direct effects of hyperglycemia on a specific microvascular bed, the vasa vasorum, promotes diabetes-associated accelerated atherosclerosis. Methods and Results: The effects of hyperglycemia on retinal and vasa vasorum neovascularization and aortic atherogenesis were examined in streptozotocin-injected apolipoprotein-E deficient (ApoE-/-) mice and normoglycemic ApoE-/- controls. Microvessel densities of the retina and vasa vasorum were quantified at 5, 10, 15 and 20 weeks of age. Atherosclerotic lesion volume in the ascending aorta was determined at the same time points. The expression levels of pro-angiogenic factors, VEGF and VEFGR2, were also determined. Data from normoglycemic ApoE-deficient mice indicate that there is an expansion in vasa vasorum density as the atherosclerotic lesion area increases. In contrast, hyperglycemic ApoE-/- mice have significantly larger atherosclerotic lesions (2 fold, P<0..05) but have no detectible neovascularization of the vasa vasorum A deficiency in VEGF expression in the artery walls of the hyperglycemic mice may explain lack of neovascularization. Conclusions: These findings indicate that the microvessel structure of the vasa vasorum is altered by hyperglycaemia. The development and progression of atherosclerosis in hyperglycemic ApoE-deficient mice directly correlates with, and may be influenced by, microvascular changes.


Sign in / Sign up

Export Citation Format

Share Document