Molecular mechanisms vascular smooth muscle cell (VSMC) acquisition of macrophage features in response to cholesterol loading
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE47744 | GEO | 2015/02/06
SECONDARY ACCESSION(S): PRJNA207550
REPOSITORIES: GEO
Similar Datasets
Project description:In this study, murine primary aortic smooth muscle cells (SMCs) were transcriptionally profiled at baseline, after 3 d of cholesterol loading, and after 3 d of subsequent cholesterol unloading with HDL treatment, to identify vascular SMC genes that are transcripionally dysregulated in response to cholesterol loading and/or unloading. Mouse aortic SMCs were isolated from thoracic aortas of 8 week-old C57BL/6 mice (as described in Rong et al., Proc Nat Acad Sci USA, v100, pp13531M-bM-^@M-^S13536, 2003) and subconfluent cell preparations were harvested and transcriptionally profiled (baseline group) or treated with 10 M-NM-<g/mL cholesterol:methyl-M-NM-2-cyclodextrin complex (1:6 molar ratio) for 72 h for cholesterol loading. Of the cholesterol-loaded cells, samples were transcriptionally profiled (cholesterol samples) or treated for an additional 72 h with 100 M-NM-<g/mL human HDL and then transcriptionally profiled (HDL treatment). For all transcriptional profiling, RNA was isolated from cells using TRIzol, and labeled aRNA was prepared for hybridization to Affymetrix Mouse Genome 430 2.0 microarrays according to the manufacturer's protocol. Probe-level intensities were background-adjusted and normalized (in two separate analyses, one with baseline and cholesterol-treated samples, and the other analysis with all three sample groups) using Robust Multichip Average and combined into probesets using probe-to-probeset mappings from the University of Michigan CustomCDF project based on Ensembl Gene identifiers (release 59). Using the data from the analysis that combined the baseline and cholesterol-loaded samples, log2 probeset intensities were compared the between baseline and cholesterol sample groups using a one-way ANOVA with a P value cutoff determined by a Benjamini-Hochberg false discovery rate threshold of 0.05. Analysis (I): baseline and cholesterol-treated sample groups. Analysis (II): all three sample groups.
2015-02-06 | E-GEOD-47744 | biostudies-arrayexpress
Project description:To map gene regulation downstream of cholesterol overload and NF-kappaB signaling in smooth muscle cells (SMCs), we cultured primary aortic SMCs from wildtype mice with cyclodextrin-complexed cholesterol or the prototypical NF-kappaB activator, tumor necrosis factor (TNF), or both.
2023-05-29 | E-MTAB-12069 | biostudies-arrayexpress
Project description:Cardiovascular disease is the leading cause of death in developed countries and there is compelling evidence that the majority of these fatalities are secondary to rupture of unstable atherosclerotic plaques. However, the mechanisms that control plaque stability are poorly understood, although it is widely believed that plaques having a decreased ratio of cells positive for smooth muscle cell (SMC) markers such as ACTA2 relative to macrophage markers are more likely to rupture. Herein we employMyh11-CreERT2 ROSA floxed STOP eYFP Apoe-/- mice to trace SMC lineage and show that traditional methods for detecting SMCs based on immunostaining for SMC markers like ACTA2 are unable to detect 82% of SMC-derived cells within advanced atherosclerotic lesions. Moreover, we show that these SMC-derived cells within advanced lesions exhibit multiple phenotypes including activation of multiple markers of macrophages, mesenchymal stem cells (MSC), and myofibroblasts (MF). Importantly, we show that SMC-derived macrophage like cells are phagocytic based on electron microscope YFP immunolabeling. In addition, results of single cell epigenetic assays developed in our lab shows that nearly 20% of macrophage-like cells within human lesions are of SMC not myeloid origin. These phenotypic transitions appear to be critical in lesion pathogenesis, in that we show that SMC-specific conditional knockout (KO) of the pluripotency factor, Krüppel-like factor 4 (KLF4), resulted in marked reductions in lesion size, increases in multiple indices of plaque stability, and reduced numbers of SMC-derived MSC- and macrophage-like cells. Finally, we show that cholesterol loading of cultured SMC is associated with activation of multiple markers of macrophages and MSC, secretion of pro-inflammatory cytokines, and increased phagocytosis, all of which are Klf4 dependent. Taken together, results indicate that the contribution of SMCs within atherosclerotic plaques has been greatly underestimated, and that loss of Klf4 within SMC result in major changes in SMC phenotype and function that play a major role in lesion pathogenesis. Examination of KLF4 transcription factor in an atherosclerosis setting
2015-04-24 | E-GEOD-65812 | biostudies-arrayexpress
Project description:Despite considerable progress understanding genes that affect the HDL particle, its function, and cholesterol content, genes identified to date explain only a small percentage of the genetic variation. We used N-ethyl-N-nitrosourea mutagenesis in mice to discover novel genes that affect HDL cholesterol levels. Two mutant lines (Hlb218 and Hlb320) with low HDL cholesterol levels were established. Causal mutations in these lines were mapped using linkage analysis: For line Hlb218 within a 12 Mbp region on Chr 10; and for line Hlb320 within a 17 Mbp region on Chr 7. High-throughput sequencing of Hlb218 liver RNA identified a mutation in Pla2g12b. The transition of G to A leads to a cysteine to tyrosine change and most likely causes a loss of a disulfide bridge. Microarray analysis of Hlb320 liver RNA showed a 7-fold downregulation of Hpn; sequencing identified a mutation in the 3M-bM-^@M-2 splice site of exon 8. Northern blot confirmed lower mRNA expression level in Hlb320 and did not show a difference in splicing, suggesting that the mutation only affects the splicing rate. In addition to affecting HDL cholesterol, the mutated genes also lead to reduction in serum non-HDL cholesterol and triglyceride levels. Despite low HDL cholesterol levels, the mice from both mutant lines show similar atherosclerotic lesion sizes compared to control mice. These new mutant mouse models are valuable tools to further study the role of these genes, their affect on HDL cholesterol levels, and metabolism. Mutant mice were generated as part of The Jackson LaboratoryM-bM-^@M-^Ys Heart, Lung, Blood, and Sleep Disorder Mutagenesis Program by treating male C57BL/6J (B6) mice with N-ethyl-N-nitrosourea (ENU). Third generation (G3) mice were phenotyped to ensure capture of both dominant and recessive mutations. Two unique G3 animals with low HDL cholesterol levels were then used to establish new inbred lines (Hlb218 and Hlb320) by mating them with B6 mice and intercrossing the offspring with low HDL cholesterol for 7 generations. Livers from 3 Hlb218, 3 Hlb320 males, and 6 B6 male controls were obtained for gene expression analysis. The samples were randomized over Illumina Mouse-6 Expression 1.1 BeadChips .
2012-06-30 | E-GEOD-37902 | biostudies-arrayexpress
Project description:To test whether cholesterol overload in smooth muscle cells (SMCs) drives NF-kappaB signaling and to map target genes controlled by NF-kappaB signaling in SMCs, we cultured primary aortic SMCs from wildtype mice in the presence of cyclodextrin-complexed cholesterol or the prototypical NF-kappaB activator tumor necrosis factor (TNF) with or without blocking canonical NF-kappaB signaling by knockdown of inhibitor of kappaB kinase beta (Ikbkb).
2023-12-07 | E-MTAB-13416 | biostudies-arrayexpress
Project description:Despite considerable progress understanding genes that affect the HDL particle, its function, and cholesterol content, genes identified to date explain only a small percentage of the genetic variation. We used N-ethyl-N-nitrosourea mutagenesis in mice to discover novel genes that affect HDL cholesterol levels. Two mutant lines (Hlb218 and Hlb320) with low HDL cholesterol levels were established. Causal mutations in these lines were mapped using linkage analysis: For line Hlb218 within a 12 Mbp region on Chr 10; and for line Hlb320 within a 17 Mbp region on Chr 7. High-throughput sequencing of Hlb218 liver RNA identified a mutation in Pla2g12b. The transition of G to A leads to a cysteine to tyrosine change and most likely causes a loss of a disulfide bridge. Microarray analysis of Hlb320 liver RNA showed a 7-fold downregulation of Hpn; sequencing identified a mutation in the 3′ splice site of exon 8. Northern blot confirmed lower mRNA expression level in Hlb320 and did not show a difference in splicing, suggesting that the mutation only affects the splicing rate. In addition to affecting HDL cholesterol, the mutated genes also lead to reduction in serum non-HDL cholesterol and triglyceride levels. Despite low HDL cholesterol levels, the mice from both mutant lines show similar atherosclerotic lesion sizes compared to control mice. These new mutant mouse models are valuable tools to further study the role of these genes, their affect on HDL cholesterol levels, and metabolism.
2012-07-01 | GSE37902 | GEO
Project description:Bacillus subtilis SMC complexes are topologically loaded at centromeric sites adjacent to the replication origin by the partitioning protein ParB. These ring-shaped ATPases then translocate down the left and right chromosome arms while tethering them together. Here we show that the site-specific recombinase XerD that resolves chromosome dimers is required to unload SMC tethers when they reach the terminus. We identify XerD-specific binding sites in the terminus region and show that they dictate the site of unloading in a manner that depends on XerD but not its catalytic residue, its partner protein XerC, or the recombination site dif. Finally, we provide evidence that ParB and XerD homologs perform similar functions in Staphylococcus aureus. Thus, loading and unloading of SMC complexes are mediated by two broadly conserved factors: one involved in origin segregation, the other in terminus resolution. Similar site-specific unloading activities could modulate eukaryotic SMC complexes during interphase and mitosis.
2021-02-24 | GSE144742 | GEO
Project description:Specific mutations in Apolipoprotein A-I (ApoA-I) of high-density lipoprotein (HDL) are responsible for a late-onset systemic amyloidosis. Carriers do not exhibit increased cardiovascular disease risk despite reduced levels of ApoA-I/ HDL-cholesterol. To explain this paradox, we show that the HDL particle profile of L75P and L174S patients presents a higher relative abundance of the 8.4 nm vs 9.6 nm particles, and that serum from patients, as well as reconstituted 8.4 and 9.6 nm HDL particles (rHDL), possess increased capacity to catalyze cholesterol efflux from macrophages. Synchrotron radiation circular dichroism and hydrogen-deuterium exchange revealed that the variants in 8.4 nm rHDL have altered secondary structure composition and display a more flexible binding to lipids compared to their native counterpart. The reduced HDL-cholesterol levels of patients carrying ApoA-I amyloidogenic variants are thus balanced by higher proportion of small, dense HDL particles and better cholesterol efflux due to altered, region-specific protein structure dynamics.
2020-11-20 | PXD021266 | Pride
Project description:In plasma, iron is normally bound to transferrin, but in conditions of iron overload when the iron-binding capacity of transferrin is exceeded, non-transferrin-bound iron (NTBI) appears in plasma. NTBI is taken up by hepatocytes and other parenchymal cells via NTBI transporters and can cause cellular damage by promoting the generation of reactive oxygen species. However, how NTBI affects endothelial cells, the most proximal cell type exposed to circulating NTBI, has not been explored. We modeled in vitro the effects of systemic iron overload on endothelial cells by treating primary human umbilical vein endothelial cells (HUVECs) with NTBI (ferric ammonium citrate, FAC). Using an unbiased approach, we showed by RNA-Seq that iron loading alters lipid homeostasis in HUVECs by inducing SREBP2-mediated cholesterol biosynthesis. We also determined that FAC increased the susceptibility of HUVECs to apoptosis induced by TNFα. Moreover, we showed that cholesterol biosynthesis contributes to iron-potentiated apoptosis. Treating HUVECs with a cholesterol chelator hydroxypropyl-β-cyclodextrin demonstrated that depletion of cholesterol was sufficient to rescue HUVECs from TNFa-induced apoptosis, even in the presence of FAC. Finally, we showed that FAC or cholesterol treatment modulated the TNFα pathway by inducing novel proteolytic processing of TNFR1 to a short isoform that localizes to lipid rafts. Our study raises the possibility that iron-mediated toxicity in human iron overload disorders is at least in part dependent on alterations in cholesterol metabolism in endothelial cells, increasing their susceptibility to apoptosis.
2021-09-01 | GSE168534 | GEO
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