GW28-e0805 Nicotine induce mast cells degranulation to increase macrophage migration and promote foam cell formation

High density lipoproteins (HDL) are athero-protective particles that promote the removal of excess cholesterol from lipid-loaded macrophages and stimulate their migration in order to protect against foam cell formation, a precursor to atherosclerotic plaque build-up. Recently, studies have shown that oxidative modification of HDL prevents HDL from protecting against atherosclerosis; however, the exact mechanisms by which this occurs are not well defined. We hypothesize that oxidative modification of HDL by reactive aldehydes such as acrolein (a major component of cigarette smoke) and 4-hydroxynonenal (HNE; a product of lipid peroxidation) impairs HDL’s athero-protective effects in macrophages. We tested our hypothesis using three different assays. First, we determined that modified forms of HDL upregulate mRNA levels of pro-atherogenic scavenger receptors such as cluster of differentiation 36 (CD36), a known oxidized LDL receptor. Incubation of macrophages with native HDL did not exert similar effects. Second, we tested the ability of oxidized HDL to prevent foam cell formation. Peritoneal macrophages isolated from WT C57Bl/J mice were cholesterol-loaded and incubated with native HDL, acrolein-modified HDL (acro-HDL), or HNE-modified HDL (HNE-HDL). Oil Red-O staining demonstrated that 24% of macrophages had foam cell formation upon incubation with native HDL, whereas 61% and 49% foam cell formation was observed for acro- and HNE-HDL, respectively. Preliminary data suggests this may be CD36-dependent. Finally, using a Boyden chamber assay, we demonstrated that both acro- and HNE-HDL, but not native HDL, had an impaired ability to promote macrophage migration (43% and 72% of HDL cell migration levels, respectively). We determined that the inability of acro- and/or HNE-HDL to stimulate macrophage migration may be due to an impaired ability of these modified lipoproteins to activate the PI3K pathway, as shown by decreased levels of phosphorylated protein kinase B (Akt). In conclusion, we have identified three independent mechanisms by which modification of HDL with acrolein or HNE impairs HDL’s cardio-protective effects and, instead, generates a particle that promotes pathways that lead to atherosclerosis.

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Abstract 639: CD36 Recruits Na/K-ATPase/Lyn Complex to Mediate Proatherogenic Phenotypes in Macrophages

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.34.suppl_1.639 ◽

2014 ◽

Vol 34 (suppl_1) ◽

Author(s):

Yiliang Chen ◽

David Kennedy ◽

Devi Prasadh Ramakrishnan ◽

Huang Wenxin ◽

Zhichuan Li ◽

...

Keyword(s):

Foam Cell ◽

Oxidized Ldl ◽

Scavenger Receptor ◽

Cell Formation ◽

Foam Cell Formation ◽

Null Mouse ◽

Macrophage Migration ◽

Lesion Area ◽

Downstream Signaling ◽

Lyn Kinase

Atherosclerosis is characterized by accumulation of macrophage foam cells in the arterial wall. We previously showed that CD36, a scavenger receptor highly expressed in macrophages, mediates oxidized-LDL (oxLDL) uptake, contributes to intracellular cholesterol accumulation and foam cell formation, and regulates macrophage migration and pro-inflammatory signaling. Genetic deletion of cd36 in mice is protective against diet-induced atherosclerosis. Mechanistically, we discovered that binding of oxLDL to CD36 activates Lyn kinase and initiates a cascade that is necessary for the pro-atherogenic cellular phenotype. Nevertheless, how CD36 regulates Lyn kinase remains undefined. We previously showed that Na/K-ATPase (NKA) regulates Src family kinases, including Lyn and we now hypothesized that CD36 regulates Lyn kinase via an interaction with NKA. We used co-immunoprecipitation and a novel immunofluorescence-based cell surface cross linking assay to demonstrate that CD36 physically associates with NKA on the macrophage surface. In a NKA α1 subunit heterozygous null mouse model in which ~60% of macrophage NKA expression is downregulated, we demonstrated that recruitment and activation of Lyn and its downstream signaling events in response to oxLDL were abolished. Functionally, we showed that NKA haploinsufficiency significantly blunted oxLDL uptake, foam cell formation and macrophage migration under atherogenic conditions. Importantly NKA α1 heterozygous null mice when bred into an apoe null background developed less atherosclerosis (26.7% lesion area in NKA control mice v.s. 13.4% lesion area in NKA heterozygous null mice) assessed by en face oil red O staining of aortae after 12 weeks on high fat diet. We conclude that by controlling Lyn kinase activity NKA critically regulates oxLDL/CD36 induced pro-atherogenic signaling.

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Abstract 113: Mast Cell Plays Pivotal Role in Nicotine-Induced Atherosclerotic Plaque Progress and Instability

Circulation Research ◽

10.1161/res.115.suppl_1.113 ◽

2014 ◽

Vol 115 (suppl_1) ◽

Author(s):

Han Chen ◽

Chen Wang ◽

Yinchuan Xu ◽

Xinyang Hu ◽

Jian-an Wang

Keyword(s):

Mast Cell ◽

Smooth Muscle ◽

High Fat Diet ◽

Foam Cell ◽

Cell Formation ◽

Mast Cell Degranulation ◽

Foam Cell Formation ◽

Macrophage Migration ◽

High Fat ◽

Plaque Instability

Objectives: Nicotine has been identified to promote atherosclerosis. But the mechanism of nicotine induced atherogenesis has not been well elucidated. This study focus on the role of mast cell in nicotine induced atherogenesis and plaque instability. Methods: Peritoneal administration of 100mM disodium cromoglicate (DSCG) was introduced to inhibit mast cell degranulation. 45 ApoE deficient mice were divided into 3 groups: high-fat diet, high-fat diet + nicotine, and high-fat diet + nicotine + DSCG. After 12 weeks of treatments, atherosclerotic lesion size of the aortas were quantified. Toluidine blue and tryptase staining identified mast cell count and activation at the lesion. Immuno-staining were used to evaluate the inflammatory filtration, smooth muscle cell proliferation and collagen content in the lesion. In vitro , bone marrow-derived mast cells (BMMCs) were harvested and treated with PBS as a negative control, compound 48/80 as a positive control,100μg/ml nicotine, nicotine with 100mM DSCG pretreatment and nicotine with 10μg/ml mecamylamine pretreatment. At 0.5hr,1hr and 2hrs, supernatants were harvested to analyze the mast cell degranulation. Futhermore, conditioned medium were also used to induce the macrophage migration and foam cell formation. Results: Nicotine increases plaque size, and macrophage infiltration, decreases smooth muscle collagen content along with the increases in mast cells count and activation ratio at the lesion, which could be inhibited by DSCG.Nicotine induced mast cell degranulation at 2 hours comparing to PBS (43.60% vs 2.3%) , which could be inhibited by mast cell stablizer DSCG (23.7%) and nAChR blocker mecamylamine (20.35%). Macrophage migration ability in the compound 48/80 and nicotine conditional medium group were significantly higher comparing to PBS, DSCG and mecamylamine group. Foam cell formation ratio in the compound 48/80 and nicotine conditional group were significantly higher comparing to PBS, DSCG and mecamylamine group. Conclusions: Nicotine induces mast cell degranulation through nAChR and then increases macrophages function, which leads to plaque instability. Administration of mast cell stabilizer showed potential of preventing nicotine induced atherogenesis.

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EM of human atherosclerosis: Aortic fatty streaks with transitional lesion features

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123519 ◽

1992 ◽

Vol 50 (1) ◽

pp. 622-623

Author(s):

K. Florian Klemp ◽

J.R. Guyton

Keyword(s):

Foam Cell ◽

Cell Formation ◽

Processing Technique ◽

Foam Cell Formation ◽

Tissue Preparation ◽

Electron Microscopic ◽

Extracellular Lipid ◽

Electron Microscopic Cytochemistry ◽

Human Atherosclerosis ◽

Clinically Significant

The earliest distinctive lesions in human atherosclerosis are fatty streaks (FS), characterized initially by lipid-laden foam cell formation. Fibrous plaques (FP), the clinically significant lesions, differ from FS in several respects. In addition to foam cells, the FP also exhibit fibromuscular proliferation and a necrotic core region rich in extracellular lipid. The possible transition of FS into mature FP has long been debated, however. A subset of FS described by Katz etal., was intermediate in lipid composition between ordinary FS and FP. We investigated this hypothesis by electron microscopic cytochemistry by employing a tissue processing technique previously described by our laboratory. Osmium-tannic acid-paraphenylenediamine (OTAP) tissue preparation enabled ultrastructural analysis of lipid deposits to discern features characteristic of mature fibrous plaques.

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Aged Garlic Extract Inhibits CD36 Expression and Foam Cell Formation in Human Macrophages

Planta Medica ◽

10.1055/s-2007-987237 ◽

2007 ◽

Vol 73 (09) ◽

Author(s):

N Ide ◽

N Morihara ◽

L Paptheodorou ◽

R Stirner ◽

N Weiss

Keyword(s):

Foam Cell ◽

Cell Formation ◽

Garlic Extract ◽

Foam Cell Formation ◽

Aged Garlic Extract ◽

Human Macrophages ◽

Cd36 Expression ◽

Aged Garlic

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Faculty Opinions recommendation of A CD36-dependent signaling cascade is necessary for macrophage foam cell formation.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1040613.489620 ◽

2006 ◽

Author(s):

Axel Nohturfft

Keyword(s):

Foam Cell ◽

Cell Formation ◽

Signaling Cascade ◽

Foam Cell Formation ◽

Macrophage Foam Cell

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Dynamic Role of Macrophage Sub Types for Development of Atherosclerosis and Potential Use of Herbal Immunomodulators as Imminent Therapeutic Strategy

Cardiovascular & Hematological Agents in Medicinal Chemistry ◽

10.2174/1871525718666201217163207 ◽

2020 ◽

Vol 18 ◽

Author(s):

Parimalanandhini Duraisamy ◽

Sangeetha Ravi ◽

Mahalakshmi Krishnan ◽

Catherene M. Livya ◽

Beulaja Manikandan ◽

...

Keyword(s):

Foam Cell ◽

Cell Formation ◽

Atherosclerotic Lesion ◽

Foam Cell Formation ◽

Atherosclerosis Progression ◽

Proinflammatory Mediators ◽

M1 Macrophage ◽

Tnf Α ◽

Inflammatory Site

: Atherosclerosis, a major contributor to cardiovascular disease is a global alarm causing mortality worldwide. Being a progressive disease in the arteries, it mainly causes recruitment of monocytes to the inflammatory sites and subside pathological conditions. Monocyte-derived macrophage mainly acts in foam cell formation by engorging the LDL molecules, oxidizes it into Ox-LDL and leads to plaque deposit development. Macrophages in general differentiate, proliferate and undergo apoptosis at the inflammatory site. Frequently two subtypes of macrophages M1 and M2 has to act crucially in balancing the micro-environmental conditions of endothelial cells in arteries. The productions of proinflammatory mediators like IL-1, IL-6, TNF-α by M1 macrophage has atherogenic properties majorly produced during the early progression of atherosclerotic plaques. To counteract cytokine productions and M1-M2 balance, secondary metabolites (phytochemicals) from plants act as a therapeutic agent in alleviating atherosclerosis progression. This review summarizes the fundamental role of the macrophage in atherosclerotic lesion formation along with its plasticity characteristic as well as recent therapeutic strategies using herbal components and anti-inflammatory cytokines as potential immunomodulators.

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ClC-3: A Novel Promising Therapeutic Target for Atherosclerosis

Journal of Cardiovascular Pharmacology and Therapeutics ◽

10.1177/10742484211023639 ◽

2021 ◽

pp. 107424842110236

Author(s):

Dun Niu ◽

Lanfang Li ◽

Zhizhong Xie

Keyword(s):

Therapeutic Target ◽

Chloride Channels ◽

Foam Cell ◽

Low Density Lipoprotein ◽

Cell Formation ◽

Density Lipoprotein ◽

Molecular Structures ◽

Foam Cell Formation ◽

Endothelium Dysfunction ◽

Atherosclerotic Process

Chloride channel 3 (ClC-3), a Cl−/H+ antiporter, has been well established as a member of volume-regulated chloride channels (VRCCs). ClC-3 may be a crucial mediator for activating inflammation-associated signaling pathways by regulating protein phosphorylation. A growing number of studies have indicated that ClC-3 overexpression plays a crucial role in mediating increased plasma low-density lipoprotein levels, vascular endothelium dysfunction, pro-inflammatory activation of macrophages, hyper-proliferation and hyper-migration of vascular smooth muscle cells (VSMCs), as well as oxidative stress and foam cell formation, which are the main factors responsible for atherosclerotic plaque formation in the arterial wall. In the present review, we summarize the molecular structures and classical functions of ClC-3. We further discuss its emerging role in the atherosclerotic process. In conclusion, we explore the potential role of ClC-3 as a therapeutic target for atherosclerosis.

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Protective Effect of Lusianthridin on Hemin-Induced Low-Density Lipoprotein Oxidation

Pharmaceuticals ◽

10.3390/ph14060567 ◽

2021 ◽

Vol 14 (6) ◽

pp. 567

Author(s):

Su Wutyi Thant ◽

Noppawan Phumala Morales ◽

Visarut Buranasudja ◽

Boonchoo Sritularak ◽

Rataya Luechapudiporn

Keyword(s):

Foam Cell ◽

Low Density Lipoprotein ◽

Cell Formation ◽

Density Lipoprotein ◽

Foam Cell Formation ◽

Raw 264.7 ◽

Low Density ◽

Lipoprotein Oxidation ◽

Raw 264.7 Macrophage Cells ◽

Low Density Lipoprotein Oxidation

Oxidation of low-density lipoprotein (LDL) plays a crucial role in the pathogenesis of atherosclerosis. Hemin (iron (III)-protoporphyrin IX) is a degradation product of hemoglobin that can be found in thalassemia patients. Hemin is a strong oxidant that can cause LDL oxidation and contributes to atherosclerosis in thalassemia patients. Lusianthridin from Dendrobium venustrum is a phenolic compound that possesses antioxidant activity. Hence, lusianthridin could be a promising compound to be used against hemin-induced oxidative stress. The major goal of this study is to evaluate the protective effect of lusianthridin on hemin-induced low-density lipoprotein oxidation (he-oxLDL). Here, various concentrations of lusianthridin (0.25, 0.5, 1, and 2 µM) were preincubated with LDL for 30 min, then 5 µM of hemin was added to initiate the oxidation, and oxidative parameters were measured at various times of incubation (0, 1, 3, 6, 12, 24 h). Lipid peroxidation of LDL was measured by thiobarbituric reactive substance (TBARs) assay and relative electrophoretic mobility (REM). The lipid composition of LDL was analyzed by using reverse-phase HPLC. Foam cell formation with he-oxLDL in RAW 264.7 macrophage cells was detected by Oil Red O staining. The results indicated that lusianthridin could inhibit TBARs formation, decrease REM, decrease oxidized lipid products, as well as preserve the level of cholesteryl arachidonate and cholesteryl linoleate. Moreover, He-oxLDL incubated with lusianthridin for 24 h can reduce the foam cell formation in RAW 264.7 macrophage cells. Taken together, lusianthridin could be a potential agent to be used to prevent atherosclerosis in thalassemia patients.

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