Activation of the pluripotency factor OCT4 in smooth muscle cells is atheroprotective. doi: 10.1038/nm.4109
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE75044 | GEO | 2016/05/15
SECONDARY ACCESSION(S): PRJNA302280
REPOSITORIES: GEO
Similar Datasets
Project description:The multiple claims about reactivation of the embryonic stem cell (ESC) pluripotency factor OCT4 in somatic cells are highly controversial due to the fact that there is no direct evidence that OCT4 has a functional role in cells other than ESCs. Herein we demonstrate that smooth muscle cell (SMC)-specific knockout of Oct4 within atherosclerotic mice resulted in increased lesion size and multiple changes consistent with decreased plaque stability. SMC-lineage tracing studies showed that lesions from SMC-specific conditional Oct4 KO mice had a reduced number of SMCs likely due to impaired SMC migration. RNA-seq analysis of lesion specimens showed that loss of Oct4 in SMCs was associated with marked activation of genes associated with inflammation and suppression of genes associated with cell migration, a number of which were shown to be activated in cultured SMCs by the combination of hypoxia and oxidized phospholipids in an OCT4-dependent manner. Activation of Oct4 within SMCs was associated with hydroxymethylation of the Oct4 promoter and was HIF1α- and KLF4-dependent. Results provide the first genetic evidence that OCT4 plays a functional role in somatic cells and highlight the importance of further investigation of possible OCT4 functions in somatic cells. In vivo: mRNA profiles of 18 week fed Western diet wild type (WT) and Oct4-/- mice were generated by deep sequencing, four animals per group, using Illumina HiSeq 2000. In vitro: a smooth muscle cell wild type (WT) and Oct4-/- (KO) primary aortic cell line was generated and used. mRNA profiles were generated by deep sequencing, in triplicates, using Illumina HiSeq 2000, for the following groups: WT-normoxia-vehicle; WT-normoxia-POVPC; KO-normoxia-vehicle; KO-normoxia-POVP; WT-hypoxia-vehicle; WT-hypoxia-POVPC; KO-hypoxia-vehicle; and KO-hypoxia-POVPC.
2016-05-15 | E-GEOD-75044 | 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:The LIM-only protein FHL2 is expressed in SMCs and inhibits SMC-rich lesion formation. However, the underlying mechanism behind FHL2's action in SMCs has been only partially resolved. To further elucidate the role of FHL2 in SMCs we compared the transcriptome of cultured SMCs derived from wild-type (WT) and FHL2-knockout (KO) mice.
2014-10-07 | GSE56860 | GEO
Project description:Until recently, the pluripotency factor OCT4 was believed to be dispensable in adult somatic cells. However, our recent studies provided clear evidence that OCT4 has a critical atheroprotective role in smooth muscle cells (SMC). Here, we demonstrate that OCT4 controls endothelial cell (EC) phenotypic modulation in atherosclerosis. We establish a new atheroprotective function for OCT4, in that EC-specific Oct4 knockout resulted in increased lipid and LGALS3+ cell accumulation, and altered plaque characteristics consistent with decreased plaque stability. A combination of single-cell RNA sequencing and EC-lineage-tracing studies revealed increased EC activation, endothelial-to-mesenchymal transitions, plaque neovascularization, and mitochondrial dysfunction in the absence of OCT4. We show that ATP transporter, ABCG2, is a direct target of OCT4 in EC, and establish for the first time that the OCT4/ABCG2 axis maintains EC metabolic homeostasis by regulating intracellular heme accumulation and related reactive oxygen species production, which, in turn, contributes to atherogenesis. These results provide the first direct evidence that OCT4 has a protective metabolic function in EC, and identifies vascular OCT4 and its signaling axis as a potential target for novel therapeutics.
2022-04-02 | GSE162119 | GEO
Project description:The LIM-only protein FHL2 is expressed in SMCs and inhibits SMC-rich lesion formation. However, the underlying mechanism behind FHL2's action in SMCs has been only partially resolved. To further elucidate the role of FHL2 in SMCs we compared the transcriptome of cultured SMCs derived from wild-type (WT) and FHL2-knockout (KO) mice. Comparison of gene expression in aortic smooth muscle cells (SMCs) isolated from WT and FHL2-knockout (FHL2-KO) mice. SMCs isolated from three mouse aortas were pooled (Kurakula et al, PLOS One, 2014). Both for WT and FHL-KO mice three batches of SMCs (derived from 9 mice) were cultured. The SMCs were grown to confluency and maintained in serum-free medium for 48 hrs before harvest. Subsequently, RNA was isolated for gene expression profiling.
2014-10-07 | E-GEOD-56860 | biostudies-arrayexpress
Project description:Unlike other terminally differentiated cell types, vascular SMCs display remarkable phenotypic plasticity. The adult, differentiated state is traditionally defined by expression of well-characterized SMC contractile genes. Extracellular cues, however, can induce contractile SMCs to remodel toward a synthetic state characterized by a spectrum of proliferative, migratory, and inflammatory phenotypes. We used whole-genome expression arrays to to identify genes associated with SMC phenotypic modulation. Experiment Overall Design: Rat aortic SMCs were serum-starved for 72 hours and subsequently treated with either PDGF-BB or its respective vehicle (n=2). RNA samples were hybridzed to Affymetrix arrays with the intent to identify early genes associated with SMC phenotypic modulation.
2009-12-02 | E-GEOD-19106 | biostudies-arrayexpress
Project description:Atherosclerotic plaque rupture with subsequent embolic events is a major cause of sudden death from myocardial infarction or stroke. Although smooth muscle cells (SMC) produce and respond to collagens in vitro, there is no direct evidence in vivo that SMC are a critical source of collagens impacting lesion development or fibrous cap formation. We sought to determine how conditional SMC specific knockout of collagen type XV (COL15A1) in SMC lineage tracing mice effects advanced lesion formation. COL15A1 was chosen because: 1) we previously identified a Col15a1 sequence variant associated with age related atherosclerosis; 2) COL15A1 is a matrix organizer that enhances tissue structural integrity; and 3) siRNA mediated Col15a1 knockdown increased migration and decreased proliferation of SMC in vitro. We hypothesized that SMC derived COL15A1 is critical in advanced lesion pathogenesis and fibrous cap formation. Surprisingly, we demonstrate that SMC specific Col15a1 knockout mice fed a Western diet for 18 weeks failed to form advanced lesions. SMC Col15a1 knockout lesions have a drastic reduction in overall lesion size, cell accumulation, and the absence of a SMC and ECM- rich lesion or fibrous cap. In vivo RNA-seq analysis on lesions +/- SMC Col15a1 knockout suggests the mechanism for these effects is complex and associated with reductions in multiple pro-atherogenic inflammatory pathways in multiple cell types involved in lesion development. These results thus provide the first direct evidence that a SMC derived collagen is critical during lesion pathogenesis. Additionally, we conclude that SMC Col15a1 knockout unexpectedly inhibited rather than exacerbated lesion pathogenesis.
2017-09-08 | GSE94661 | GEO
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.
2015-04-24 | GSE65812 | GEO
Project description:Despite decades of research, our understanding of processes controlling the stability of late-stage atherosclerotic plaques remains poor. However, a prevailing hypothesis is that reducing inflammation may improve plaque stability. Indeed, the potent inflammatory cytokine, interleukin-1β (IL-1β), has been shown to be a key driver of atherosclerosis development. Importantly, the CANTOS Trial recently demonstrated that administration of an anti-IL-1β antibody to high-risk post-myocardial infarction (MI) patients reduced the incidence of recurrent nonfatal MI, but did not reduce the incidence of cardiovascular death or stroke. As such, although the CANTOS trial results providing exciting evidence that targeting inflammation can have clinical benefit for treating advanced atherosclerosis, extensive further investigation is needed to better understand the mechanisms by which IL-1β inhibition impacts established lesions. Therefore, we performed intervention studies on smooth muscle cell (SMC) lineage tracing mice with advanced atherosclerosis using anti-IL- 1 or IgG control antibodies. Surprisingly, we found no effect on lesion size but a profound shift in the composition of the fibrous cap characterized by reduced collagen and SMC content but an increase in macrophage number, which was primarily driven by opposite effects on the proliferation of these respective cell types. By generating SMC-specific and macrophage-selective Il1r1 KO Apoe -/- mice, we found that SMC-specific Il1r1 KO resulted in a ~60% reduction in lesion size and lesions that were nearly devoid of YFP + SMC whereas, myeloid-selective loss of IL1R1 had no effect on lesion size, or cell composition. This suggests that SMC are a primary cell type responding to IL-1β in atherosclerosis and that IL1 signaling in SMC is critical for their investment and retention within the fibrous cap. In addition, we found that inhibition of IL-1β promoted an expansion of the M2 macrophage population within the fibrous cap, and that these effects may be due in part to elevated levels of IL4. Taken together, results show that IL-1β can promote beneficial changes in late-stage murine atherosclerosis by promoting maintenance of a SMC/collagen-rich fibrous cap. Moreover, studies identify critical cell types and pathways that need to be considered when attempting to develop safer and more effective anti-inflammatory therapies for widespread treatment of atherosclerotic disease, including in moderate or low risk patients.
2018-07-12 | GSE111535 | GEO
Project description:Smooth muscle cells (SMCs) and endothelial cells (ECs) constitute vasculature media and endothelium, respectively. Current treatments for cardiovascular disease inhibit SMC hyperplasia but also damage the protective endothelial lining, predisposing patients to thrombosis. Therapeutics targeting SMCs without collateral damage to ECs are highly desirable. However, differential (SMCs versus ECs) disease-associated regulations remain poorly defined. We conducted RNA-seq experiments to investigate SMC-versus-EC differential transcriptomic dynamics, following treatment of human primary SMCs and ECs with TNFα or IL-1β, both established inducers of SMC hyperplasia and EC dysfunction. To analyze combined SMC/EC transcriptomes we developed customized algorithms. Induced by TNFα or IL-1β, 212 and 263 genes respectively showed greater up-regulation in SMCs than in ECs (SMC-enriched), while 140 and 204 genes showed greater up-regulation in ECs over SMCs (EC-enriched). Analysis of gene interaction networks identified 5 common hubs and 4 common bottlenecks in the two SMC-enriched gene sets, and 8 hubs and 3 bottlenecks shared in the EC-enriched gene sets. Significantly, four gene modules were formed with these hubs and bottlenecks. While the JUN module (including JUN, KLF5, HIF1A, CXCL8, FOSL1) and FYN module (FYN, JAK2, MAP2, PIK3R3, DAB2, ASAP2) were SMC-enriched, the SMAD3 (SMAD3, CDKN1A, TRAF1, BCL6, CEBPD, TRIB3, ANK3) and XPO1 (XPO1, ETS2, SSH2, NDRG1, GFPT2?) modules were EC-enriched. As these core subnetworks respond to pathogenic stimulation in a SMC-versus-EC differential manner, they may inform potential intervention targets for selective mitigation of SMC hyperplasia without endothelial damage.
2018-02-14 | GSE96962 | GEO