Effects of acLDL loading on macrophage
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE19926 | GEO | 2010/12/31
SECONDARY ACCESSION(S): PRJNA121999
REPOSITORIES: GEO
Similar Datasets
Project description:acLDL loading of mouse peritoneal macrophage is an in vitro foam cell model. We have used microarray analysis and proteomics to characterize the effects of acLDL loading on the cells. Macrophages were harvested from the peritoneum of C57Bl/6J mice 5 days after injection of thioglycolate. Thioglycollate elicited macrophage were cultured for 2 days in DMEM + 10%FBS either in the presence or absence of 50 microgram/mL acLDL. 4 indepdendent biological replicates were used for each condition.
2010-12-31 | E-GEOD-19926 | biostudies-arrayexpress
Project description:Macrophage death in advanced atherosclerotic lesions is a key event in the conversion of benign lesions to vulnerable plaques. One fundamental transcription factor that has been shown to play a pivotal role in cell death/survival is nuclear factor kB (NF-kB). Still, the relevance of this key transcription factor for macrophage-derived foam cell survival has not been unequivocally resolved at the molecular level. THP-1 monocytic cell lines were generated in which NF-kB activation is specifically inhibited by overexpression of a trans-dominant, non-degradable form of IkBa (IkBa (32A/36A)) under control of the macrophage-specific SR-A promoter. A diminished lipid loading during NF-κB inhibition during foam cell formation was accompanied by increased cell death. A genome-wide expression profile of NF-kB-dependent genes during foam cell formation was established showing a widespread effect on the macrophage transcriptome. The three largest functional gene clusters identified and validated by independent techniques, were those involved in lipid metabolism, apoptosis and oxidative stress. The net result of these complex gene expression changes invoked by inhibition of NF-κB activation during lipid loading is a reduction of foam cell survival through caspase-dependent apoptosis. Thus, the NF-kB-dependent gene repertoire seems essential for sustained macrophage survival during the process of pathological lipid loading. Keywords: genetic modification, lipid loading, timecourse THP-1 cells and two different THP-1 IkB mutants (A3 and A12) were exposed to PMA to induce macrophage differentiation and subsequently loaded with oxidized LDL or vehicle for 5 or 8 days. One replicate per array, a total of 15 arrays. A common reference pool, composed of an equimolar mixture of all samples, was labeled with Cy3 and hybridized against the Cy5-labeled experimental sample.
2010-06-24 | E-GEOD-12434 | biostudies-arrayexpress
Project description:Macrophage death in advanced atherosclerotic lesions is a key event in the conversion of benign lesions to vulnerable plaques. One fundamental transcription factor that has been shown to play a pivotal role in cell death/survival is nuclear factor kB (NF-kB). Still, the relevance of this key transcription factor for macrophage-derived foam cell survival has not been unequivocally resolved at the molecular level. THP-1 monocytic cell lines were generated in which NF-kB activation is specifically inhibited by overexpression of a trans-dominant, non-degradable form of IkBa (IkBa (32A/36A)) under control of the macrophage-specific SR-A promoter. A diminished lipid loading during NF-κB inhibition during foam cell formation was accompanied by increased cell death. A genome-wide expression profile of NF-kB-dependent genes during foam cell formation was established showing a widespread effect on the macrophage transcriptome. The three largest functional gene clusters identified and validated by independent techniques, were those involved in lipid metabolism, apoptosis and oxidative stress. The net result of these complex gene expression changes invoked by inhibition of NF-κB activation during lipid loading is a reduction of foam cell survival through caspase-dependent apoptosis. Thus, the NF-kB-dependent gene repertoire seems essential for sustained macrophage survival during the process of pathological lipid loading. Keywords: genetic modification, lipid loading, timecourse
2009-08-11 | GSE12434 | GEO
Project description:Macrophages are critical components of atherosclerotic lesions and their pro- and anti-inflammatory responses influence atherogenesis. Type-I interferons (IFNs) are cytokines that play an essential role in antiviral responses and inflammatory activation and have been shown to promote atherosclerosis. Although the impact of type-I IFNs on macrophage foam cell formation is well-documented, the effect of lipid accumulation in monocytes and macrophages on type-I IFN responses remains unknown. Here we examined IFN stimulated (ISG) and non-ISG inflammatory gene expression in mouse and human macrophages that were loaded with acetylated LDL (acLDL), as a model for foam cell formation. We found that acLDL loading in mouse and human macrophages specifically suppressed expression of ISGs and IFN-β secretion, but not other pro-inflammatory genes. The downregulation of ISGs could be rescued by exogenous IFN-β supplementation. Activation of the cholesterol-sensing nuclear liver X receptor (LXR) recapitulated the cholesterol-initiated type-I IFN suppression. Additional analyses of murine in vitro and in vivo generated foam cells confirmed the suppressed IFN signalling pathways and suggest that this phenotype is mediated via downregulation of interferon regulatory factor binding at gene promoters. Finally, RNA-seq analysis of monocytes of familial hypercholesterolemia (FH) patients also showed type-I IFN suppression which was restored by lipid-lowering therapy and not present in monocytes of healthy donors. Taken together, we define type-I IFN suppression as an athero-protective characteristic of foamy macrophages. These data provide new insights into the mechanisms that control inflammatory responses in hyperlipidaemic settings and can support future therapeutic approaches focusing on reprogramming of macrophages to reduce atherosclerotic plaque progression and improve stability.
2022-02-10 | GSE192709 | GEO
Project description:Macrophages are critical components of atherosclerotic lesions and their pro- and anti-inflammatory responses influence atherogenesis. Type-I interferons (IFNs) are cytokines that play an essential role in antiviral responses and inflammatory activation and have been shown to promote atherosclerosis. Although the impact of type-I IFNs on macrophage foam cell formation is well-documented, the effect of lipid accumulation in monocytes and macrophages on type-I IFN responses remains unknown. Here we examined IFN stimulated (ISG) and non-ISG inflammatory gene expression in mouse and human macrophages that were loaded with acetylated LDL (acLDL), as a model for foam cell formation. We found that acLDL loading in mouse and human macrophages specifically suppressed expression of ISGs and IFN-β secretion, but not other pro-inflammatory genes. The down regulation of ISGs could be rescued by exogenous IFN-β supplementation. Activation of the cholesterol-sensing nuclear liver X receptor (LXR) recapitulated the cholesterol-initiated type-I IFN suppression. Additional analyses of murine in vitro and in vivo generated foam cells confirmed the suppressed IFN signaling pathways and suggest that this phenotype is mediated via down regulation of interferon regulatory factor binding at gene promoters. Finally, RNA-seq analysis of monocytes of familial hypercholesterolemia (FH) patients also showed type-I IFN suppression which was restored by lipid-lowering therapy and not present in monocytes of healthy donors. Taken together, we define type-I IFN suppression as an athero-protective characteristic of foamy macrophages. These data provide new insights into the mechanisms that control inflammatory responses in hyperlipidaemic settings and can support future therapeutic approaches focusing on reprogramming of macrophages to reduce atherosclerotic plaque progression and improve stability.
2022-07-01 | GSE193118 | GEO
Project description:Background: Cardiovascular diseases remain the leading cause of morbidity and mortality worldwide, most of which are caused by atherosclerosis. Discerning processes that participate in macrophage-to-foam cell formation are critical for understanding the basic mechanisms underlying atherosclerosis. To explore the molecular mechanisms of foam cell formation, the differentially expressed proteins were identified. Methods: In this paper, human monocytes, macrophage colony-stimulating factor induced macrophages, and oxidized low-density lipoprotein induced foam cells were cultured, and tandem mass tag (TMT) labeling combined with mass spectrometry (MS) were performed to find associations between foam cell transformation and proteome profiles. Results: Totally, 5146 quantifiable proteins were identified, among which 1515 and 182 differentially expressed proteins (DEPs) were found in macrophage/monocyte and foam cell/macrophage, respectively, using a cutoff of 1.5-fold change. Subcellular localization analysis revealed that downregulated DEPs of macrophages/monocytes were mostly located in the nucleus and upregulated DEPs of foam cells/macrophages mostly located in the plasma membrane and extracellular. Functional analysis of DEPs demonstrated that cholesterol metabolism related proteins were upregulated in foam cells, whereas the immune response-related proteins were downregulated in foam cells. The protein-interaction network showed that the DEPs with the highest interaction intensity between macrophages and foam cells were mainly concentrated in lysosomes and the endoplasmic reticulum. Conclusions: This study for the first time to perform quantitative proteomic investigation by TMT labeling and LC-MS/MS to identify differentially expressed proteins in human monocyte, macrophage, and foam cell. The results confirmed cholesterol metabolism was upregulated in foam cells, while immune response was suppressed, which suggested that foam cells were not the population that promote inflammation. In addition, KEGG enrichment analysis and protein-protein interaction indicated that the differentially expressed proteins locating in the endoplasmic reticulum and lysosomes may be key targets to regulate foam cell formation. These data provide a basis for identifying the potential proteins associated with the molecular mechanism involved in the transformation of macrophages to foam cells.
2022-02-15 | PXD028363 | Pride
Project description:Strain effects on the response to cholesterol loading in bone marrow derived macrophages (BMM) are not well studied. The atherosclerosis susceptible strain, DBA/2 on the ApoE deficient background and the atherosclerosis resistant AKR strains show differences in cholesterol handling when loaded with AcLDL. To understand the molecular basis for these differences, BMM from both strains were loaded with acetylated low desnisty lipoprotein (AcLDL) and gene expression quantified. BMMs from AKR greatly upregulated transcripts involved in the lysosomal trafficking pathway. This experiment strongly suggest that upregualtion of the lysosomal pathway in response to AcLDL maybe protective against atherosclerosis. In addition we find that transcripts containing the sterol response element (SRE) motif had strong strain-loading interactions suggesting a strain response to SRE response.
2013-06-30 | GSE38736 | GEO
Project description:Bone marrow derived macrophage vs peritoneal macrophage
| PRJNA414129 | ENA
Project description:To investigate the relationship between hypercholesterolemia, foam cell formation and inflammation, we performed lipidomic and transcriptomic analyses of elicited peritoneal macrophages in wild type (WT) or LDL receptor knockout (LDLR KO) mice fed either a normal cholesterol, normal fat (NCNF) diet or a high cholesterol, high fat (HCHF) 'Western' style diet. The combination of the LDLR KO genotype and the HCHF diet results in the formation of macrophage foam cells in the elicited peritoneal macrophage population. Analysis of macrophages from the above four experimental groups revealed massive reprogramming of the lipidome in response to both diet and genotype. These studies confirmed and extended prior knowledge regarding the roles of SREBP and LXR signaling in cholesterol and fatty acid homeostasis. Unexpectedly, peritoneal macrophage foam cells exhibited a strongly 'deactivated' phenotype, with marked suppression of pro-inflammatory mediators that are normally characteristic of the inflammatory responses associated with atherosclerotic lesions. Many of these changes in gene expression and lipid metabolism appear to be related to the paradoxical accumulation of high levels of desmosterol, the last intermediate in the Bloch pathway of cholesterol biosynthesis. WT or LDLR KO mice were fed either a NCNF diet or a HCHF diet for twelve weeks to establish four experimental groups (WT-NCNF diet, WT-HCHF diet, KO-NCNF diet, and KO-HCHF diet). As expected, the combination of the HCHF diet and LDLR KO genotype resulted in a synergistic effect on serum lipid levels. Elicited peritoneal macrophages (92-96% F4/80-positive) were immediately prepared for analysis, thereby preserving in vivo gene expression and lipid profiles. Macrophages derived from LDLR KO mice fed the HCHF diet contained nearly four-fold more total cholesterol than cells from WT mice fed the same diet. Quantitative analysis of 245 lipid species revealed significant changes in nearly all major lipid classes. Using a two-way ANOVA model, we found that 176 (72%) of the lipids analyzed were significantly affected by the HCHF diet, 133 (54%) by the LDLR KO genotype, and 114 (46%) by interactions between the HCHF diet and LDLR KO genotype. Many of the observed interactions (60%) were synergistic.
2019-12-17 | ST001289 | MetabolomicsWorkbench