P1942A trait of inflammation pathogenesis in human atherosclerosis: inflammasome driven interleukin-1 signaling in complex atherosclerotic plaques via hyperlipidemia trained innate immunity

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
X Jiang ◽  
F Wang ◽  
J Wang ◽  
A Gistera ◽  
J Roy ◽  
...  

Abstract A trait of inflammation pathogenesis in human atherosclerosis: inflammasome driven interleukin-1 signalling in complex atherosclerotic plaques via hyperlipidemia trained innate immunity Objectives We aimed to investigate interleukin (IL)-1 generation and the regulatory role of inflammasome in human advanced atherosclerosis. Background IL-1β is key contributor to the inflammatory process associated with atherosclerosis and its complications. Recent studies suggested that IL-1β blockade reduces the burden of inflammation and recurrence of cardiovascular events. Yet, other cytokines in IL-1 family and the regulation of IL-1 generation in patients with atherosclerosis remains poorly understood. Methods and results A focused transcriptomic analysis in human atherosclerotic specimens discovered that human atherosclerotic plaques host a broad reservoir of inflammasome components, characterised by expression of canonical inflammasome gene NLRP6, NLRP12, NLRC4, NLRP3 and non-canonical inflammasome gene caspase 4 significantly elevated in the symptomatic plaques versus the asymptomatic plaques. Upregulation of NLRP3 inflammasome expression in plaque validated by immunohistochemistry staining suggested it as a distinctive characteristic of plaque vulnerability and complexity. Functional studies on atherosclerotic explants obtained from patients undergoing carotid endarterectomy revealed constitutive generation of IL-1β accompanied by secretion of comparable levels of IL-1α from the majority of the plaques, while IL-18 and IL-33 generation from some of the plaques. Stimulation of the plaques with inflammasome activators showed an inducible generation of both IL-1α and IL-1β, not IL-18 or IL-33, mediated by specific canonical and non-canonical inflammasome pathways. Analysis on the medication records of these patients indicated that plaques from patients with suboptimally controlled hyperlipidemia, imaging signs for plaque instability and inadequate statins therapy possessed higher recruitable production of IL-1β, suggesting the conventional atherogenic factor in regulation of inflammasome immunity and disease activity. Mechanistic studies on tissue and cells isolated from atheromatous plaques demonstrate that generation of mature IL-1β is via a mechanism controlled by NLRP3 and the effector caspase-1. Conclusions The study supports a profound canonical and non-canonical inflammasomes mediated plaque IL-1α/β generation, via a key mechanism by NLRP3 and caspase-1. The results provide biological insights into the clinical merit of high-intensity cholesterol lowering and anti-IL-1 signalling-directed therapies in high-risk patients with atherosclerosis. Acknowledgement/Funding KI-Mayo collaboration project, the Swedish Research Council, the Swedish Heart-Lung Foundation, European Union FP7 projects, the NIH

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
R I Hodas ◽  
D Opincariu ◽  
N Rat ◽  
I Rodean ◽  
M Chitu ◽  
...  

Abstract Funding Acknowledgements PlaqueImage.- research grant no. 103544/2016, contract number 26/01.09.2016 - Background Previous studies demonstrated that plaque morphology has a crucial role in the development of an acute coronary syndrome (ACS). However, not all vulnerable coronary plaques produce an ACS and the prediction power of various vulnerability features to predict an acute coronary event in a close future, has not been elucidated so far. Objective We aimed to use multi-slice computed tomography angiography (CTA) for assessment of morphological characteristics of culprit lesions producing an ACS in the next several months after CT assessment, in comparison with morphological characteristics of unstable coronary atherosclerotic plaques which did not trigger an ACS. Material and methods We analyzed 40 patients in whom CTA revealed presence of unstable coronary lesions, exhibiting at least one marker of vulnerability: napkin ring sign (NRS), spotty calcium (SC), positive remodeling (PR) or presence of low attenuation plaque (LAP), divided in 2 groups: group 1 - 20 patients who developed an ACS in the next 6 months following CTA examination, and group 2 – 20 patients matched for age, gender and risk factors, who did not present any cardiovascular event 6 month after CTA assessment. Post-processing of multi-slice CTA images was performed in order to assess morphological characteristics and CT-derived markers of atherosclerotic plaque instability. Results Similar mean values of plaque length (17.1 +/- 5.9 mm vs 16.9 +/- 3.4 mm; p = 0.6) and total atheroma volume (188.1 +/- 104.7 mm3vs 186.4 +/- 90.7 mm3; p = 0.8) were obtained for both groups. The mean number of vulnerability markers was 1.6 in group 1 vs 1.2 in group 2 (p = 0.07). However, atherosclerotic lesions in patients from group 1 presented significantly higher values of lipid-rich atheroma (9.8 +/- 10.8 mm3vs 2.6 +/- 1.0 mm3; p = 0.01) and remodeling index (1.14 +/- 0.3 in group 1 vs 0.89 +/- 0.19 in group 2, p = 0.04). At the same time, atheromatous plaques in patients who developed an ACS during the 6-months follow-up showed in a significantly higher proportion LAP (45% in group vs 10% in group 2, p = 0.03) and PR (15%in group 1 versus 5% in group 2, p = 0.04), but not NRS (30% vs 25%, p = ns) or SC (65% vs 40%, p = 0.2). Conclusions Atherosclerotic plaques producing an ACS exhibit a different phenotype than unstable plaques that remain silent. The CTA profile of atheromatous plaques producing an ACS includes the presence of low attenuation, positive remodeling, higher RI and lipid-rich atheroma. Presence of these features in high-risk coronary plaques identifies very high risk patients, who can benefit from adapted therapeutic strategy in order to prevent the development of an ACS.


2021 ◽  
Author(s):  
Paula González-López ◽  
Carla Ares-Carral ◽  
Andrea R. López-Pastor ◽  
Jorge Infante-Menéndez ◽  
Tamara Gonzalez-Illanes ◽  
...  

Abstract Background: Cardiovascular diseases (CVDs) are the main cause of death in first world countries, being atherosclerosis, a recurring process underlying their apparition. MicroRNAs (miRNAs) are small non-coding RNAs that modulate the expression of their target proteins. Therefore, they have emerged as key players in diseases like cancer, diabetes, or CVDs.Methods: Apolipoprotein E-deficient (ApoE-/-) mice fed a standard type diet (STD) or high fat diet (HFD) for 8 and 18 weeks was compared to wild type (WT) STD-fed groups for the same time. 18 miRNAs were selected (from pubmed and GEO database) for their possible role in promoting atherosclerosis and were analysed by RT-qPCR in the aorta from the experimental model. Afterwards, the altered miRNAs in the aorta from 18 weeks-ApoE-/- mice were studied in human healthy aortic samples, human early aortic atherosclerotic plaques, and human advanced carotid atherosclerotic plaques. Results: From the 18 miRNAs analyzed, miR-155-5p was overexpressed and miR-143-3p was downregulated in mouse and human atherosclerotic lesions. In addition, a significant decrease of protein kinase B (AKT), target of miR-155-5p, and an increase of insulin-like growth factor type II receptor (IGF-IIR), target of miR-143-3p, were noted in aortic roots from ApoE-/- mice and in carotid plaques from ACA patients. Finally, both miRNAs were studied on vascular endothelial and smooth muscle cell lines. The overexpression of miR-155-5p reduced AKT levels and its phosphorylation in vascular smooth muscle cells. MiR-143-3p overexpression decreased IGF-IIR reducing apoptosis in vascular cells. Conclusions: Our results suggest that miR-155-5p and miR-143-3p may be implicated in insulin resistance and plaque instability by the modulation of their targets AKT and IGF-IIR, contributing to the progression of experimental and human atherosclerosis.Trial Registration: authorization numbers PFS09-007 and PI1442016.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Judith C Sluimer ◽  
Job L van Wanroij ◽  
Matthijs Groeneweg ◽  
Bradly G Wouters ◽  
Mat J Daemen ◽  
...  

Intraplaque neovascularization is linked to plaque instability and thought to be stimulated by hypoxia. However, hypoxia has not been demonstrated yet in human atherosclerosis. The hypoxia marker pimonidazole was administrated intravenously 2 hours prior to carotid endarterectomy in 6 symptomatic patients to evaluate the presence of hypoxia. Subsequent immunohistochemistry of the operatively removed atherosclerotic plaques demonstrated the presence of hypoxia, especially in the macrophage-rich center of the lesions. Notably, two hypoxic gradients were observed: hypoxia was very strong in the center of the plaque, but almost absent close to the main artery lumen and in the media. hypoxia was most intense in segments with advanced atheroma and almost absent in segments containing only diffuse intimal thickening. Hypoxia strongly correlated with CD68 immunoreactivity (ρ= 0.7, p=0.000), neovascularization (ρ= 0.6, p=0.000) and the presence of a thrombus (ρ= 0.4, p=0.009). In addition, hypoxia co-localized with expression of HIF1α and VEGF . To exclude that pimonidazole immunoreactivity in the atherosclerotic plaque was the result of surgery-induced ischemia, arterial wall segments were collected at two time-points: directly after incision of the carotid artery and directly following excision of the plaque. Pimonidazole immunoreactivity in these two pieces was not different, suggesting that hypoxia and pimonidazole adducts were already present in the plaques before surgery . To show that pimonidazole reactivity was hypoxia-specific and independent of reactive oxygen species, human THP-1 macrophages were exposed to normoxia (20% O 2 ), hypoxia (0.2% O 2 ) and/or H 2 O 2 (100 μM) in the presence of pimonidazole. Indeed, flow cytometry only showed pimonidazole-positive cells after hypoxic exposure. This is the first study proving direct evidence of the existence of hypoxia in advanced human atherosclerotic lesions, most prominently in the macrophage-rich center. Also, hypoxia was associated with the expression of HIF1α, VEGF and intraplaque microvessels, suggesting its involvement in the regulation of human intraplaque neovascularization.


2013 ◽  
Vol 81 (8) ◽  
pp. 2997-3008 ◽  
Author(s):  
Wei Li ◽  
Barry P. Katz ◽  
Margaret E. Bauer ◽  
Stanley M. Spinola

ABSTRACTRecognition of microbial infection by certain intracellular pattern recognition receptors leads to the formation of a multiprotein complex termed the inflammasome. Inflammasome assembly activates caspase-1 and leads to cleavage and secretion of the proinflammatory cytokines interleukin-1 beta (IL-1β) and IL-18, which help control many bacterial pathogens. However, excessive inflammation mediated by inflammasome activation can also contribute to immunopathology. Here, we investigated whetherHaemophilus ducreyi, a Gram-negative bacterium that causes the genital ulcer disease chancroid, activates inflammasomes in experimentally infected human skin and in monocyte-derived macrophages (MDM). AlthoughH. ducreyiis predominantly extracellular during human infection, several inflammasome-related components were transcriptionally upregulated inH. ducreyi-infected skin. Infection of MDM with live, but not heat-killed,H. ducreyiinduced caspase-1- and caspase-5-dependent processing and secretion of IL-1β. Blockage ofH. ducreyiuptake by cytochalasin D significantly reduced the amount of secreted IL-1β. Knocking down the expression of the inflammasome components NLRP3 and ASC abolished IL-1β production. Consistent with NLRP3-dependent inflammasome activation, blocking ATP signaling, K+efflux, cathepsin B activity, and lysosomal acidification all inhibited IL-1β secretion. However, inhibition of the production and function of reactive oxygen species did not decrease IL-1β production. Polarization of macrophages to classically activated M1 or alternatively activated M2 cells abrogated IL-1β secretion elicited byH. ducreyi. Our study data indicate thatH. ducreyiinduces NLRP3 inflammasome activation via multiple mechanisms and suggest that the heterogeneity of macrophages within human lesions may modulate inflammasome activation during human infection.


2013 ◽  
Vol 48 (5) ◽  
pp. 655-664 ◽  
Author(s):  
Rebecca A. Martin ◽  
Jennifer L. Ather ◽  
Lennart K. A. Lundblad ◽  
Benjamin T. Suratt ◽  
Jonathan E. Boyson ◽  
...  

2009 ◽  
Vol 37 (4) ◽  
pp. 1029-1037 ◽  
Author(s):  
Z Qiao ◽  
J Ren ◽  
H Chen

Lipoprotein-associated phospholipase A2 (Lp-PLA2) contributes to atherosclerotic plaque instability and subsequent sudden coronary death. Statins are associated with decreased stroke risk and may improve stability of atherosclerotic plaques. The present study investigated the effect of simvastatin on expression of Lp-PLA2 levels in atherosclerotic plaques and on Lp-PLA2 activity in atherosclerotic aortas. Rabbits were a fed chow (control group) or a high-cholesterol diet (atherosclerosis group) for 12 weeks. An additional group on the high-cholesterol diet received simvastatin (5 mg/kg per day) for the last 4 weeks (simvastatin group). Lp-PLA2 activity in plasma and atherosclerotic aortas was significantly higher in the atherosclerosis group than in the control group and, consistent with this, abundant Lp-PLA2 protein was detected in plaques in the atherosclerosis group. Simvastatin significantly reduced Lp-PLA2 activity in plasma and aorta tissue, and reduced Lp-PLA2 protein level in atherosclerotic plaques. Whereas there was no significant difference in total atherosclerotic lesion area between simvastatin and atherosclerosis groups, simvastatin significantly reduced macrophage content, lipid retention and the intima/media ratio but increased the content of smooth muscle cells in atherosclerotic lesions. Thus, statin treatment markedly reduced Lp-PLA2 in both plasma and atherosclerotic plaques. This was associated with attenuation of the local inflammatory response and improved plaque stability.


2016 ◽  
Vol 2 (7) ◽  
pp. e1600224 ◽  
Author(s):  
Denuja Karunakaran ◽  
Michele Geoffrion ◽  
Lihui Wei ◽  
Wei Gan ◽  
Laura Richards ◽  
...  

Atherosclerosis results from maladaptive inflammation driven primarily by macrophages, whose recruitment and proliferation drive plaque progression. In advanced plaques, macrophage death contributes centrally to the formation of plaque necrosis, which underlies the instability that promotes plaque rupture and myocardial infarction. Hence, targeting macrophage cell death pathways may offer promise for the stabilization of vulnerable plaques. Necroptosis is a recently discovered pathway of programmed cell necrosis regulated by RIP3 and MLKL kinases that, in contrast to apoptosis, induces a proinflammatory state. We show herein that necroptotic cell death is activated in human advanced atherosclerotic plaques and can be targeted in experimental atherosclerosis for both therapeutic and diagnostic interventions. In humans with unstable carotid atherosclerosis, expression of RIP3 and MLKL is increased, and MLKL phosphorylation, a key step in the commitment to necroptosis, is detected in advanced atheromas. Investigation of the molecular mechanisms underlying necroptosis showed that atherogenic forms of low-density lipoprotein increase RIP3 and MLKL transcription and phosphorylation—two critical steps in the execution of necroptosis. Using a radiotracer developed with the necroptosis inhibitor necrostatin-1 (Nec-1), we show that 123I-Nec-1 localizes specifically to atherosclerotic plaques in Apoe−/− mice, and its uptake is tightly correlated to lesion areas by ex vivo nuclear imaging. Furthermore, treatment of Apoe−/− mice with established atherosclerosis with Nec-1 reduced lesion size and markers of plaque instability, including necrotic core formation. Collectively, our findings offer molecular insight into the mechanisms of macrophage cell death that drive necrotic core formation in atherosclerosis and suggest that this pathway can be used as both a diagnostic and therapeutic tool for the treatment of unstable atherosclerosis.


2017 ◽  
Vol 14 (4) ◽  
pp. 3471-3476 ◽  
Author(s):  
Huiying Zhao ◽  
Xiujiao Qin ◽  
Shuai Wang ◽  
Xiwei Sun ◽  
Bin Dong

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