scholarly journals High-capacity selective uptake of cholesteryl ester from native LDL during macrophage foam cell formation

2012 ◽  
Vol 53 (10) ◽  
pp. 2081-2091 ◽  
Author(s):  
Jason M. Meyer ◽  
Ailing Ji ◽  
Lei Cai ◽  
Deneys R. van der Westhuyzen
Keyword(s):  
Cholesteryl Ester ◽  
Foam Cell ◽  
Cell Formation ◽  
High Capacity ◽  
Foam Cell Formation ◽  
Macrophage Foam Cell ◽  
Selective Uptake

Leptin modulates ACAT1 expression and cholesterol efflux from human macrophages

2009 ◽  
Vol 297 (2) ◽  
pp. E474-E482 ◽  
Author(s):  
Shigeki Hongo ◽  
Takuya Watanabe ◽  
Shigeko Arita ◽  
Tomoko Kanome ◽  
Haruaki Kageyama ◽  
...  
Keyword(s):  
Cholesteryl Ester ◽  
Cholesterol Efflux ◽  
Leptin Receptor ◽  
Foam Cell ◽  
Cell Formation ◽  
Human Monocyte ◽  
Foam Cell Formation ◽  
Monocytic Differentiation ◽  
Macrophage Foam Cell ◽  
Cholesteryl Ester Accumulation

Leptin is an adipose tissue-derived hormone implicated in atherosclerosis and macrophage foam cell formation. The current study was conducted to examine the effect of leptin on cholesteryl ester accumulation in human monocytes/macrophages. Exogenously added leptin at 5 nM during differentiation of monocytes into macrophages for 7 days accelerated acetylated LDL (acetyl-LDL)-induced cholesteryl ester accumulation by 30–50%. Leptin did not affect endocytic uptake of acetyl-LDL; however, it increased ACAT activity 1.8-fold and ACAT-1 protein expression 1.9-fold. Among the four ACAT-1 mRNA transcripts, two shorter transcripts (2.8 and 3.6 kb) were upregulated ∼1.7-fold upon leptin treatment. The enhanced expression of ACAT-1 protein by leptin was suppressed by inhibitors of Janus-activated kinase2 (JAK2) and phosphatidylinositol 3-kinase (PI3K). HDL-mediated cholesterol efflux was suppressed by leptin, which was canceled by K-604, an ACAT-1 inhibitor. Expression of long form of leptin receptor was upregulated during monocytic differentiation into macrophages and sustained after differentiation. Thus, the results suggest that leptin accelerates cholesteryl ester accumulation in human monocyte-derived macrophages by increasing ACAT-1 expression via JAK2 and PI3K, thereby suppressing cholesterol efflux.

scholarly journals A Chlamydia pneumoniae Component That Induces Macrophage Foam Cell Formation Is Chlamydial Lipopolysaccharide

1998 ◽  
Vol 66 (11) ◽  
pp. 5067-5072 ◽  
Author(s):  
Murat V. Kalayoglu ◽  
Gerald I. Byrne
Keyword(s):  
Cholesteryl Ester ◽  
Chlamydia Pneumoniae ◽  
Elevated Temperatures ◽  
Foam Cell ◽  
Cell Formation ◽  
Disease Process ◽  
Foam Cell Formation ◽  
Human Macrophage ◽  
Macrophage Foam Cell ◽  
Cholesteryl Ester Accumulation

ABSTRACT Chlamydia pneumoniae infection is associated with atherosclerotic heart and vessel disease, but a causal relationship between this pathogen and the disease process has not been established. Recently, it was reported that C. pneumoniae induces human macrophage foam cell formation, a key event in early atheroma development, suggesting a role for the organism in atherogenesis. This study further examines C. pneumoniae-induced foam cell formation in the murine macrophage cell line RAW-264.7. Infected RAW cells accumulated cholesteryl esters when cultured in the presence of low-density lipoprotein in a manner similar to that described for human macrophages. Exposure of C. pneumoniae elementary bodies to periodate, but not elevated temperatures, inhibited cholesteryl ester accumulation, suggesting a role for chlamydial lipopolysaccharide (cLPS) in macrophage foam cell formation. Purified cLPS was found to be sufficient to induce cholesteryl ester accumulation and foam cell formation. Furthermore, the LPS antagonist lipid X inhibited C. pneumoniae and cLPS-induced lipid uptake. These data indicate that cLPS is a C. pneumoniae component that induces macrophage foam cell formation and suggest that infected macrophages chronically exposed to cLPS may accumulate excess cholesterol to contribute to atheroma development.

scholarly journals Glucose-Dependent Insulinotropic Polypeptide Suppresses Foam Cell Formation of Macrophages through Inhibition of the Cyclin-Dependent Kinase 5-CD36 Pathway

Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 832
Author(s):  
Michishige Terasaki ◽  
Hironori Yashima ◽  
Yusaku Mori ◽  
Tomomi Saito ◽  
Yoshie Shiraga ◽  
...  
Keyword(s):  
Gene Expression ◽  
Foam Cell ◽  
Cell Formation ◽  
Foam Cell Formation ◽  
U937 Cells ◽  
Cyclin Dependent Kinase ◽  
Macrophage Foam Cell ◽  
Cyclin Dependent Kinase 5 ◽  
Gip Receptor ◽  
Cd36 Gene

Glucose-dependent insulinotropic polypeptide (GIP) has been reported to have an atheroprotective property in animal models. However, the effect of GIP on macrophage foam cell formation, a crucial step of atherosclerosis, remains largely unknown. We investigated the effects of GIP on foam cell formation of, and CD36 expression in, macrophages extracted from GIP receptor-deficient (Gipr−/−) and Gipr+/+ mice and cultured human U937 macrophages by using an agonist for GIP receptor, [D-Ala2]GIP(1–42). Foam cell formation evaluated by esterification of free cholesterol to cholesteryl ester and CD36 gene expression in macrophages isolated from Gipr+/+ mice infused subcutaneously with [D-Ala2]GIP(1–42) were significantly suppressed compared with vehicle-treated mice, while these beneficial effects were not observed in macrophages isolated from Gipr−/− mice infused with [D-Ala2]GIP(1–42). When macrophages were isolated from Gipr+/+ and Gipr−/− mice, and then exposed to [D-Ala2]GIP(1–42), similar results were obtained. [D-Ala2]GIP(1–42) attenuated ox-LDL uptake of, and CD36 gene expression in, human U937 macrophages as well. Gene expression level of cyclin-dependent kinase 5 (Cdk5) was also suppressed by [D-Ala2]GIP(1–42) in U937 cells, which was corelated with that of CD36. A selective inhibitor of Cdk5, (R)-DRF053 mimicked the effects of [D-Ala2]GIP(1–42) in U937 cells. The present study suggests that GIP could inhibit foam cell formation of macrophages by suppressing the Cdk5-CD36 pathway via GIP receptor.

scholarly journals Inhibitory effects of Mycoepoxydiene on macrophage foam cell formation and atherosclerosis in ApoE-deficient mice

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Xiaochun Xia ◽  
Yang Li ◽  
Qiang Su ◽  
Zhengrong Huang ◽  
Yuemao Shen ◽  
...  
Keyword(s):  
Foam Cell ◽  
Cell Formation ◽  
Foam Cell Formation ◽  
Inhibitory Effects ◽  
Macrophage Foam Cell ◽  
Deficient Mice

scholarly journals IL-33 promotes IL-10 production in macrophages: a role for IL-33 in macrophage foam cell formation

2017 ◽  
Vol 49 (11) ◽  
pp. e388-e388 ◽  
Author(s):  
Hai-Feng Zhang ◽  
Mao-Xiong Wu ◽  
Yong-Qing Lin ◽  
Shuang-Lun Xie ◽  
Tu-Cheng Huang ◽  
...  
Keyword(s):  
Foam Cell ◽  
Cell Formation ◽  
Foam Cell Formation ◽  
Macrophage Foam Cell

Abstract 276: Shockwave Reduces Macrophage Foam Cell Formation Via Increased Expression of ATP Binding Cassette Transporters.

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Wonkyoung Cho ◽  
Young Eun Yoon ◽  
Kihwan Kwon ◽  
Young Mi Park
Keyword(s):  
Western Blot ◽  
Foam Cell ◽  
Cell Formation ◽  
Foam Cell Formation ◽  
Atp Binding ◽  
Mrna Levels ◽  
Macrophage Foam Cell ◽  
Migration Assay ◽  
Intracellular Cholesterol ◽  
Atp Binding Cassette

Background: Excessive lipid accumulation by macrophages plays a crucial role in atherosclerosis. Foam cells are generated by uncontrolled uptake of modified LDL, especially oxidized LDL (oxLDL), and/or impaired cholesterol efflux mediated by ATP-binding cassette (ABC) family transporters, ABCA-1 and ABCG-1. Shockwave, elicited by transient pressure disturbance, have been used for extracorporeal lithotripsy or for treating musculoskeletal disorders. Our current study suggests an evidence that shockwave may have anti-atherogenic effect by inhibiting foam cell formation. Methods/Results: Murine peritoneal macrophages were exposed to shockwaves at 0.04 mJ/mm 2 with 1000 impulses, lysed after 6, 18 and 24 hours, and tested for expression of ABCA-1 and ABCG-1. The western blot showed that shockwave induced 2.0-2.8 fold increase of ABCA-1 and ABCG-1 within 18-24 hours. mRNA levels of ABCA-1 and ABCG-1 were also increased by shockwave with 2.0 fold of peak increase in 18 hours. The increased expression of ABCA-1 and ABCG-1 was mediated by phosphorylation of ERK 1/2 (Tyr204). Western blot analysis revealed that shockwave induced phosphorylation of ERK 1/2 (Tyr204) in murine macrophages. Shockwave-induced increase of ABCA-1 and ABCG-1 was blocked by U0126 (40µM), a specific inhibitor for ERK. Oil-red O staining showed that macrophages exposed to shockwave had 25% less intracellular lipid droplets. Intracellular cholesterol measured by cholesterol oxidase and esterase revealed that macrophages exposed to shockwave had 23% less intracellular cholesterol when incubated with oxLDL (50µg/ml) for 16 hours. In vitro migration assays including modified Boyden chamber migration assay and scratch wound healing migration assay showed that macrophages exposed to shockwave had 1.2 fold more migration and had diminished migration-inhibitory effect of oxLDL. Conclusions: Shockwave reduces macrophage foam cell formation via ERK-mediated increase of ABCA-1 and ABCG-1 mediating lipid efflux and promotes macrophage migration which may induce macrophage egress from atherosclerotic lesion. Our study suggests anti-atherogenic effects of shockwave as a potential treatment modality for atherosclerosis.

Abstract 356: IKK-Beta Deletion Alleviates the Atherogenetic Effect of Intermittent Hypoxia Induced Macrophage Foam Cell Formation

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Toshihiro Imamura ◽  
Iain S Hartley ◽  
Abdull J Massri ◽  
Orit Poulsen ◽  
Dan Zhou ◽  
...  
Keyword(s):  
Gene Expression ◽  
Intermittent Hypoxia ◽  
Foam Cell ◽  
Cell Formation ◽  
Foam Cell Formation ◽  
Wild Type ◽  
Nf Kappa B ◽  
Macrophage Foam Cell ◽  
Obstructive Sleep ◽  
Intracellular Cholesterol

Background: Obstructive sleep apnea syndrome (OSAS) is a common sleeping disorder characterized by intermittent hypoxia (IH). Clinical studies have previously shown an independent association between obstructive sleep apnea and atherosclerosis. Furthermore, it has been previously shown that such a predisposition to atherosclerosis in OSAS patient can be caused by various inflammatory mediators, particularly the NF-kappa B (NF-kB) pathway. Foam cells or lipid-laden macrophages in the atherosclerotic lesion have been well documented as a hallmark of atherosclerosis; however, the contribution of IH, such as in OSAS, to foam cell formation is not yet fully understood. Previous observations have led us to hypothesized that IH induces macrophage foam cell formation due to the activation of NF-kappa B pathway. Methods: Myeloid restricted IKK-beta deleted mice were generated by a Cre/lox recombination system to inactivate the NF-kB pathway in macrophages. Thioglycollate-elicited peritoneal macrophages were incubated with 200 μg/ml of low-density lipoprotein and simultaneously exposed to either IH (Normoxia: 8min, 0.5% O2: 10min) or normoxia for 24 hours. After exposure, the extent of foam cell formation was assessed by quantification of intracellular cholesterol. Finally, we compared the differences in gene expression using RNA-seq between wild type and IKK-beta deleted macrophages exposed to either IH or normoxia for 24 hours. Results: IH significantly increased total cholesterol in wild type macrophages (63.4±3.3 μg/mg of cellular protein, n=9) in comparison to normoxia (51.2±1.6). Interestingly, such increase in intracellular cholesterol in response to IH-exposure was abolished by IKK-beta deletion (IH 52.4±1.1; normoxia 50.0±1.6 n=8), suggesting that NF-kB pathway regulated gene expression is critical for IH-induced foam cell formation. Indeed, we have found that NF-kB knockout abolished IH-induced expressional alterations in 364 genes, which are potential candidates for regulating intracellular cholesterol. Conclusion: NF-kB activation plays a critical role in IH-induced macrophage foam cell formation.

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