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 ◽  
...  

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.

2020 ◽  
Vol 21 (23) ◽  
pp. 9263
Author(s):  
Hironori Yashima ◽  
Michishige Terasaki ◽  
Ami Sotokawauchi ◽  
Takanori Matsui ◽  
Yusaku Mori ◽  
...  

Advanced glycation end products (AGEs) are localized in macrophage-derived foam cells within atherosclerotic lesions, which could be associated with the increased risk of atherosclerotic cardiovascular disease under diabetic conditions. Although foam cell formation of macrophages has been shown to be enhanced by AGEs, the underlying molecular mechanism remains unclear. Since cyclin-dependent kinase 5 (Cdk5) is reported to modulate inflammatory responses in macrophages, we investigated whether Cdk5 could be involved in AGE-induced CD36 gene expression and foam cell formation of macrophages. AGEs significantly increased Dil-oxidized low-density lipoprotein (ox-LDL) uptake, and Cdk5 and CD36 gene expression in U937 human macrophages, all of which were inhibited by DNA aptamer raised against RAGE (RAGE-aptamer). Cdk5 and CD36 gene expression levels were correlated with each other. An antioxidant, N-acetyl-l-cysteine, mimicked the effects of RAGE-aptamer on AGE-exposed U937 cells. A selective inhibitor of Cdk5, (R)-DRF053, attenuated the AGE-induced Dil-ox-LDL uptake and CD36 gene expression, whereas anti-CD36 antibody inhibited the Dil-ox-LDL uptake but not Cdk5 gene expression. The present study suggests that AGEs may stimulate ox-LDL uptake into macrophages through the Cdk5–CD36 pathway via RAGE-mediated oxidative stress.


2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Toshihiro Imamura ◽  
Iain S Hartley ◽  
Abdull J Massri ◽  
Orit Poulsen ◽  
Dan Zhou ◽  
...  

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.


2007 ◽  
Vol 29 (2) ◽  
pp. 149-160 ◽  
Author(s):  
Hyung Jun Cho ◽  
Pavel Shashkin ◽  
Christian A. Gleissner ◽  
Dane Dunson ◽  
Nitin Jain ◽  
...  

Foam cell formation from monocyte-derived macrophages is a hallmark of atherosclerotic lesions. Aspects of this process can be recapitulated in vitro by exposing M-CSF-induced or platelet factor 4 (CXCL4)-induced macrophages to oxidized (ox) or minimally modified (mm) low density lipoprotein (LDL). We measured gene expression in peripheral blood mononuclear cells, monocytes, and macrophages treated with CXCL1 (GRO-α) or CCL2 (MCP-1), as well as foam cells induced by native LDL, mmLDL, or oxLDL using 22 Affymetrix gene chips. Using an advanced Bayesian error-pooling approach and a heterogeneous error model with a false discovery rate <0.05, we found 5,303 of 22,215 probe sets to be significantly regulated in at least one of the conditions. Among a subset of 917 candidate genes that were preselected for their known biological functions in macrophage foam-cell differentiation, we found that 290 genes met the above statistical criteria for significant differential expression patterns. While many expected genes were found to be upregulated by LDL and oxLDL, very few were induced by mmLDL. We also found induction of unexpected genes, most strikingly MHC-II and other dendritic cell markers such as CD11c. The gene expression patterns in response to oxLDL were similar in M-CSF-induced and CXCL4-induced macrophages. Our findings suggest that LDL and oxLDL, but not mmLDL, induce a dendritic cell-like phenotype in macrophages, suggesting that these cells may be able to present antigens and support an immune response.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Xiaochun Xia ◽  
Yang Li ◽  
Qiang Su ◽  
Zhengrong Huang ◽  
Yuemao Shen ◽  
...  

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

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Wonkyoung Cho ◽  
Young Eun Yoon ◽  
Kihwan Kwon ◽  
Young Mi Park

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.


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