Abstract 22: Absence of Circadian Gene Bmal in Macrophage Enhances Atherosclerosis

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Xiao Yu Tian ◽  
Yuhong Huang ◽  
Wing Tak Wong ◽  
Ajay Chawla ◽  
Yu Huang
Keyword(s):  
Circadian Rhythm ◽  
Inflammatory Responses ◽  
Atherosclerotic Lesion ◽  
Myeloid Cell ◽  
Control Flow ◽  
Peripheral Cell ◽  
Atherosclerotic Plaque Formation ◽  
En Face ◽  
Inflammatory Macrophages

Backgrounds: Peripheral cell-intrinsic clock is present in all types of cells and is important for synchronization of physiological function in response to changes of environment. Bmal (encoded by Arntl gene) is a transcription factor that forms complex with Clock and induces rhythmic transcription. Peripheral clock has been demonstrated in monocyte to regulate inflammatory responses. In this regards, we hypothesize that disruption of circadian rhythm in myeloid cells enhances atherosclerosis in Apoe -/- mice. Methods and Results: Apoe -/- mice housed under weekly switch between regular (ZT12-ZT0: dark) and inverted (ZT12-ZT0: light) ligh/dark cycle developed more atherosclerotic lesion than Apoe-/- mice housed under regular L/D cycle. Myeloid cell-specific Bmal knockout mice ( Arntl LoxP/LoxP Lyz2 Cre ) as Bmal MKO and Bmal wild type ( Arntl LoxP/ LoxP ) as Bmal MWT were crossbred with Apoe-/- to generate Apoe-Bmal MKO and Apoe-Bmal MWT mice. Mice with disruption of myeloid circadian rhythm (Apoe-Bmal MKO ) on Western diet showed enhanced atherosclerotic plaque formation by en face oil red o staining, compared with their WT control. Flow cytometry showed more infiltrating macrophages within the plaque of Apoe-Bmal MKO mice, accompanied with upregulation of proinflammatory genes Tnf, Il1b, Nos2, S100a8; chemokines and adhesion molecules Vcam1, Icam1, Sele, Ccl2, Ccl8; and downregulation of anti-inflammatory genes. Aortic root staining showed more macrophages by CD68 staining, more CD11c + pro-inflammatory macrophages, and more Ly6c + infiltrating monocyte-derived macrophages in Apoe-Bmal MKO mice. In vitro culture of bone marrow derived macrophage from Apoe-Bmal MKO and Apoe-Bmal MWT mice demonstrated that deletion of myeloid Bmal impaired rhythmic transcription of Ccl2 and Ccl8, causing higher expressions. Meanwhile, lipid profile and endothelial function were unaltered in Apoe-Bmal MKO compared with Apoe-Bmal MWT mice. Conclusions: Our data showed disruption of myeloid circadian rhythm increased inflammation and enhanced atherosclerosis

Silencing of junctional adhesion molecule-like protein attenuates atherogenesis and enhances plaque stability in ApoE−/− mice

2019 ◽  
Vol 133 (11) ◽  
pp. 1215-1228 ◽  
Author(s):  
Yu Sun ◽  
Juan Guan ◽  
Yunfeng Hou ◽  
Fei Xue ◽  
Wei Huang ◽  
...  
Keyword(s):  
Adhesion Molecule ◽  
Wound Repair ◽  
Inflammatory Responses ◽  
Atherosclerotic Lesion ◽  
Atherosclerotic Plaques ◽  
Plaque Stability ◽  
Fibrous Cap ◽  
Enhanced Expression

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.

Abstract 180: Increased Atherosclerosis Associated with Periodontal Disease Is Mediated by CD36

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Maria Febbraio ◽  
Paul M Brown
Keyword(s):  
Periodontal Disease ◽  
Alveolar Bone ◽  
Inflammatory Responses ◽  
Disease Risk ◽  
Plasma Cholesterol ◽  
Atherosclerotic Lesion ◽  
Pcr Analysis ◽  
Modified Ldl ◽  
Oxidatively Modified

We previously showed that inflammation, and not hyperlipidemia alone, was necessary for CD36 dependent atherogenesis. Chronic periodontal disease is characterized by a persistent inflammatory state and is epidemiologically associated with cardiovascular disease. We hypothesize that CD36 is an essential link between periodontal disease and atherosclerosis. Low density lipoprotein receptor knock out (LDLR KO) mice and CD36/LDLR double KO mice were infected with the periodontal disease associated bacteria, Porphyromonas gingivalis (Pg), by oral lavage and fed a Western diet for 12 weeks (n = 7-14/group). We assessed periodontal disease, risk factors associated with atherosclerosis, and lesion burden. We conducted studies in isolated macrophages to understand mechanistic differences between the groups. Wild type and CD36 KO macrophages equally phagocytosed bacteria. We measured the cemento-enamel junction of each molar to assess periodontal disease and found that it was significantly increased in infected mice compared with uninfected controls. Histological analysis showed neutrophil, osteoclast and macrophage infiltrates in the alveolar bone of infected mice. Differences in plasma cholesterol, triacylglycerol, insulin resistance and weight gain did not necessarily track with atherosclerosis burden, however blood neutrophils and cytokines were increased in infected LDLR KO mice compared with all other groups. Infected LDLR KO mice had significantly increased atherosclerotic lesion burden compared with uninfected LDLR KO mice, and all of the increased lesion was CD36 dependent. PCR analysis found no evidence for direct infection of atherosclerotic lesions by Pg. In vitro macrophage studies showed that heat killed Pg, lipopolysaccharide (LPS) derived from Pg, oxidatively modified LDL or plasma from infected mice, could not activate the NALP3 inflammasome. Combining heat killed Pg or Pg LPS with oxidatively modified LDL or plasma from infected mice, however, led to significant IL-1 beta secretion that was CD36 and NFkB dependent. Our data suggest that atherosclerosis associated with periodontal disease is mediated by cellular inflammatory responses involving both CD36 and Toll-like receptor.

Abstract 175: Lack of Macrophage GLUT1-Mediated Glucose Metabolism Increases Atherosclerotic Lesion Instability

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Liyang Zhao ◽  
Alex Freemerman ◽  
Amy R Johnson ◽  
Sneha Sundaram ◽  
Taylor Christensen ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Inflammatory Response ◽  
Glucose Transporter ◽  
Inflammatory Responses ◽  
Fasting Blood Glucose ◽  
Atherosclerotic Lesion ◽  
Metabolic Reprogramming ◽  
Phagocytic Capacity ◽  
Activated State

Macrophages play a key role in the pathogenesis of atherosclerosis. Metabolic programs powered by glucose or lipid enable macrophages to elicit pro- or anti-inflammatory responses, respectively. Although the chronic inflammatory feature of atherosclerosis has been well-established, the role of macrophage substrate metabolism in atherogenesis remains unclear. We previously demonstrated that macrophages with elevated GLUT1-mediated glucose metabolism have an increased inflammatory response. Therefore, we created a novel macrophage GLUT1-deficient murine model by crossing GLUT1 floxed to LysM-Cre mice. Recent work suggests that lack of GLUT1 reduces the pro-inflammatory response and the ability for GLUT1-/- macrophages to polarize to the classically activated state in vitro. Therefore, the objective of this study was to examine how macrophage metabolic reprogramming affects the development of atherosclerosis. We hypothesized that macrophages with restricted glucose metabolism due to lack of glucose transporter GLUT1 will have reduced pro-inflammatory activation during atherogenesis. We transplanted bone marrow from Glut1MΦfl/fl or Glut1MΦ-/- mice into Ldlr-/- mice and fed mice a Western diet for 12 weeks. Glut1MΦfl/fl Ldlr-/- or Glut1MΦ-/- Ldlr-/- chimeric mice did not exhibit significant differences in body weight, body composition, blood pressure, fasting blood glucose, or triacylglycerol and LDL and HDL cholesterol. Digital histology analysis of Oil Red O stained slides indicated that deleting macrophage GLUT1 did not affect total lesion area in aortic root; however, mice with blunted glucose metabolism displayed more and larger necrotic cores. Ongoing studies are investigating apoptosis and phagocytic capacity of macrophages with and without GLUT1 to elucidate the roles of macrophage glucose metabolism on the morphology of atherosclerotic lesion. In summary, we observed that mice lacking macrophage GLUT1 developed increased necrotic cores in lesions of the aorta root relative to mice with wild type macrophage GLUT1 which suggests that maintenance of atherosclerotic lesion stability may be regulated by glucose-dependent mechanisms.

scholarly journals Reduced atherosclerosis lesion size, inflammatory response in miR-150 knockout mice via macrophage effects

2018 ◽  
Vol 59 (4) ◽  
pp. 658-669 ◽  
Author(s):  
Fu-Han Gong ◽  
Wen-Lin Cheng ◽  
Haiping Wang ◽  
Maomao Gao ◽  
Juan-Juan Qin ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Knockout Mice ◽  
Noncoding Rna ◽  
Inflammatory Responses ◽  
Atherosclerotic Lesion ◽  
Lesion Size ◽  
Endothelial Cell Proliferation ◽  
Double Knockout

Atherosclerosis is considered to be a chronic inflammatory disease that can lead to severe clinically important cardiovascular events. miR-150 is a small noncoding RNA that significantly enhances inflammatory responses by upregulating endothelial cell proliferation and migration, as well as intravascular environmental homeostasis. However, the exact role of miR-150 in atherosclerosis remains unknown. Here, we investigated the effect of miR-150 deficiency on atherosclerosis development. Using double-knockout (miR-150−/− and ApoE−/−) mice, we measured atherosclerotic lesion size and stability. Meanwhile, we conducted in vivo bone marrow transplantation to identify cellular-level components of the inflammatory response. Compared with mice deficient only in ApoE, the double-knockout mice had significantly smaller atherosclerotic lesions and displayed an attenuated inflammatory response. Moreover, miR-150 ablation promoted plaque stabilization via increases in smooth muscle cell and collagen content and decreased macrophage infiltration and lipid accumulation. The in vitro experiments indicated that an inflammatory response with miR-150 deficiency in atherosclerosis results directly from upregulated expression of the cytoskeletal protein, PDZ and LIM domain 1 (PDLIM1), in macrophages. More importantly, the decreases in phosphorylated p65 expression and inflammatory cytokine secretion induced by miR-150 ablation were reversed by PDLIM1 knockdown. These findings suggest that miR-150 is a promising target for the management of atherosclerosis.

Fibronectin Isoform Containing the Alternatively-Spliced Extra Domain A in Circulation Accelerates the Development of Atherosclerosis in Mice

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2205-2205
Author(s):  
Chintan Gandhi ◽  
Mohammad Moshahid Khan ◽  
Anil K Chauhan
Keyword(s):  
Atherosclerotic Plaque ◽  
Inflammatory Responses ◽  
Conflicts Of Interest ◽  
Atherosclerotic Lesion ◽  
Plaque Formation ◽  
Western Diet ◽  
High Fat ◽  
Aortic Sinus ◽  
Atherosclerotic Plaque Formation ◽  
Alternatively Spliced

Abstract Abstract 2205 Background and Objective: The fibronectin isoform containing the alternatively-spliced extra domain A (EDA+-FN) is normally absent from the circulation, but plasma levels of EDA+-FN can become markedly elevated in several pathological conditions including atherosclerosis. It remains unclear in humans whether these elevated levels of EDA+-FN are actively contributing to disease pathogenesis, or rather simply serving as a marker associated with vascular stress and/or injury. Several in vitro studies suggest that EDA+-FN can activate toll-like receptor 4 (TLR4), an innate immune receptor that triggers pro-inflammatory responses We hypothesize that presence of EDA+-FN in plasma promotes inflammation and accelerates atherosclerotic plaque formation. Model and Method: We generated EDA+/+/ApoE−/− mice, which contain optimized spliced sites at both splicing junctions of the EDA exon and constitutively express only EDA+-FN, and EDA−/−/ApoE−/− mice, which contain an EDA-null allele of the EDA exon and express only FN lacking EDA. ApoE−/−, EDA+/+/ApoE−/− and EDA−/−/ApoE−/− were fed a high-fat Western diet (21% fat and 0.2% cholesterol) beginning at 6 weeks until they were sacrificed at 5 months of age (i.e., 14 weeks on high-fat Western diet). We compared the extent of atherosclerosis in whole aortae, stained with Oil Red O and en face lesion area measured by morphometry, and in the cross section area of the aortic sinus using the VerHoeffs/Van Gieson stain. Results: We report that atherosclerotic plaque (% of total aorta) formation in the aorta of EDA+/+/ApoE−/− mice was increased by two-fold compared to control ApoE−/− mice (P<0.0001). Deletion of the alternatively spliced EDA domain in the ApoE−/− mice (EDA−/−/ApoE−/−) significantly reduced atherosclerotic plaque formation in the aorta (P<0.05) compared to ApoE−/− mice. Total cholesterol and triglycerides levels were similar in ApoE−/−, EDA+/+/ApoE−/− and EDA−/−/ApoE−/− mice. Similarly, atherosclerotic plaque formation was significantly increased in the aortic sinus of EDA+/+/ApoE−/− mice, intermediate in control ApoE−/− mice and reduced in EDA−/−/ApoE−/− mice (P<0.05). Additionally, we found that macrophage content, as analyzed by immunohistochemistry, was significantly elevated in the aortic root lesions of EDA+/+/ApoE−/− mice and reduced in EDA−/−/ApoE−/− mice compared to ApoE−/− mice (P<0.05). Moreover, EDA+-FN did not affect the sex-dependent regulation of atherosclerosis in ApoE−/− mice. Future experiments using EDA+/+/ApoE−/−/TLR4−/− are under progress to determine whether EDA+-FN exacerbate atherosclerosis via upregulating TLR4 signaling. Conclusions: Our findings reveal that EDA+-FN is pro-inflammatory and promotes atherosclerotic lesion formation and that monitoring plasma EDA+-FN might have prognostic value in patients at high risk for atherosclerosis. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Endotoxinemia Accelerates Atherosclerosis via Electrostatic Charge-Mediated Monocyte Adhesion

Circulation ◽  
2020 ◽  
Author(s):  
Ariane Schumski ◽  
Almudena Ortega-Gómez ◽  
Kanin Wichapong ◽  
Carla Winter ◽  
Patricia Lemnitzer ◽  
...  
Keyword(s):  
Vascular Inflammation ◽  
Acute Infection ◽  
Atherosclerotic Lesion ◽  
Myeloid Cell ◽  
Lesion Size ◽  
Histone H2a ◽  
Monocyte Adhesion ◽  
Arterial Lumen ◽  
Lps Treatment

Background: Acute infection is a well-established risk factor of cardiovascular inflammation increasing the risk for a cardiovascular complication within the first weeks after infection. However, the nature of the processes underlying such aggravation remains unclear. Lipopolysaccharide (LPS) derived from Gram-negative bacteria is a potent activator of circulating immune cells including neutrophils, which foster inflammation through discharge of neutrophil extracellular traps (NETs). Here we utilize a model of endotoxinemia to link acute infection and subsequent neutrophil activation with acceleration of vascular inflammation. Methods: Acute infection was mimicked by injection of a single dose of LPS into hypercholesterolemic mice. Atherosclerosis burden was studied by histomorphometric analysis of the aortic root. Arterial myeloid cell adhesion was quantified by intravital microscopy. Results: LPS treatment rapidly enhanced atherosclerotic lesion size by expansion of the lesional myeloid cell accumulation. LPS treatment led to the deposition of NETs along the arterial lumen and inhibition of NET release annulled lesion expansion during endotoxinemia, thus suggesting that NETs regulate myeloid cell recruitment. To study the mechanism of monocyte adhesion to NETs, we employed in vitro adhesion assays and biophysical approaches. In these experiments, NET-resident histone H2a attracted monocytes in a receptor-independent, surface charge-dependent fashion. Therapeutic neutralization of histone H2a by antibodies or by in silico designed cyclical peptides enables us to reduce luminal monocyte adhesion and lesion expansion during endotoxinemia. Conclusions: Our study shows, that NET-associated histone H2a mediates charge-dependent monocyte adhesion to NETs and accelerates atherosclerosis during endotoxinemia.

Discovery of N-Phenyl-4-(1H-pyrrol-3-yl)pyrimidin-2-amine Derivatives as Potent Mnk2 Inhibitors: Design, Synthesis, SAR Analysis, and Evaluation of in vitro Anti-leukaemic Activity

2019 ◽  
Vol 15 (6) ◽  
pp. 602-623 ◽  
Author(s):  
Ahmed M. Abdelaziz ◽  
Sarah Diab ◽  
Saiful Islam ◽  
Sunita K.C. Basnet ◽  
Benjamin Noll ◽  
...  
Keyword(s):  
Proliferative Activity ◽  
Myeloid Cell ◽  
Structural Diversity ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Cell Leukaemia ◽  
Aberrant Expression ◽  
Design Synthesis ◽  
Induced Apoptosis

Background:Aberrant expression of eukaryotic translation initiation factor 4E (eIF4E) is common in many types of cancer including acute myeloid leukaemia (AML). Phosphorylation of eIF4E by MAPK-interacting kinases (Mnks) is essential for the eIF4E-mediated oncogenic activity. As such, the pharmacological inhibition of Mnks can be an effective strategy for the treatment of cancer.Methods:A series of N-phenyl-4-(1H-pyrrol-3-yl)pyrimidin-2-amine derivatives was designed and synthesised. The Mnk inhibitory activity of these derivatives as well as their anti-proliferative activity against MV4-11 AML cells was determined.Results:These compounds were identified as potent Mnk2 inhibitors. Most of them demonstrated potent anti-proliferative activity against MV4-11 AML cells. The cellular mechanistic studies of the representative inhibitors revealed that they reduced the level of phosphorylated eIF4E and induced apoptosis by down-regulating the anti-apoptotic protein myeloid cell leukaemia 1 (Mcl-1) and by cleaving poly(ADP-ribose)polymerase (PARP). The lead compound 7k possessed desirable pharmacokinetic properties and oral bioavailability.Conclusion:This work proposes that exploration of the structural diversity in the context of Nphenyl- 4-(1H-pyrrol-3-yl)pyrimidin-2-amine would offer potent and selective Mnk inhibitors.

scholarly journals Mitochondrial arginase-2 is essential for IL-10 metabolic reprogramming of inflammatory macrophages

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jennifer K. Dowling ◽  
Remsha Afzal ◽  
Linden J. Gearing ◽  
Mariana P. Cervantes-Silva ◽  
Stephanie Annett ◽  
...  
Keyword(s):  
Metabolic Regulation ◽  
Mitochondrial Dynamics ◽  
Interleukin 10 ◽  
Metabolic Reprogramming ◽  
In Vivo Model ◽  
Macrophage Polarisation ◽  
Inflammatory Status ◽  
Inflammatory Macrophages

AbstractMitochondria are important regulators of macrophage polarisation. Here, we show that arginase-2 (Arg2) is a microRNA-155 (miR-155) and interleukin-10 (IL-10) regulated protein localized at the mitochondria in inflammatory macrophages, and is critical for IL-10-induced modulation of mitochondrial dynamics and oxidative respiration. Mechanistically, the catalytic activity and presence of Arg2 at the mitochondria is crucial for oxidative phosphorylation. We further show that Arg2 mediates this process by increasing the activity of complex II (succinate dehydrogenase). Moreover, Arg2 is essential for IL-10-mediated downregulation of the inflammatory mediators succinate, hypoxia inducible factor 1α (HIF-1α) and IL-1β in vitro. Accordingly, HIF-1α and IL-1β are highly expressed in an LPS-induced in vivo model of acute inflammation using Arg2−/− mice. These findings shed light on a new arm of IL-10-mediated metabolic regulation, working to resolve the inflammatory status of the cell.

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