Clonal Haematopoiesis-related Mutant ASXL1 Promotes Atherosclerosis in Mice via Dysregulated Innate Immunity [scRNA-seq]
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE279601 | GEO | 2024/10/25
REPOSITORIES: GEO
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Project description:Certain somatic mutations confer a fitness advantage in hematopoietic stem cells, resulting in the clonal expansion of mutant blood cells, known as clonal haematopoiesis (CH). Among the top 3 CH mutations, ASXL1 mutations present the highest risk for developing cardiovascular diseases (CVDs). However, how ASXL1 mutations induce CVDs remains totally elusive. Here we show that haematopoietic cells harbouring C-terminally truncated form of ASXL1 mutant (ASXL1-MT) accelerated development of atherosclerosis in Ldlr–/– mice. Transcriptome analyses of plaque-cells showed inflammatory signatures of monocytes and macrophages expressing ASXL1-MT. Mechanistically, wild-type ASXL1 inhibited innate immune signalling through the inhibition of IRAK1-TAK1 interaction in the cytoplasm, indicating an unexpected non-epigenetic role of ASXL1. In contrast, ASXL1-MT lost this regulatory function, leading to NF-κB activation. Intriguingly, IRAK1/4 inhibition decreased inflammatory monocytes and atherosclerosis driven by ASXL1-MT. The present work connects ASXL1 mutations with inflammation and CVDs, giving a clue to prevent CVDs in ASXL1-CH.
2024-10-25 | GSE279450 | GEO
Project description:Somatic mutations of ASXL1 are frequently detected in age-related clonal hematopoiesis (CH). However, how ASXL1 mutations drive CH remains elusive. Using knockin (KI) mice expressing a C-terminally truncated form of ASXL1-mutant (ASXL1-MT), we examined the influence of ASXL1-MT on physiological aging in hematopoietic stem cells (HSCs). HSCs expressing ASXL1-MT display competitive disadvantage after transplantation. Nevertheless, in genetic mosaic mouse model, they acquire clonal advantage during aging, recapitulating CH in humans. Mechanistically, ASXL1-MT cooperates with BAP1 to deubiquitinate and activate AKT. Overactive Akt/mTOR signaling induced by ASXL1-MT results in aberrant proliferation and dysfunction of HSCs associated with age-related accumulation of DNA damage. Treatment with an mTOR inhibitor rapamycin ameliorates aberrant expansion of the HSC compartment as well as dysregulated hematopoiesis in aged ASXL1-MT KI mice. Our findings suggest that ASXL1-MT provokes dysfunction of HSCs, whereas it confers clonal advantage on HSCs over time, leading to the development of CH.
2021-02-08 | MSV000086816 | MassIVE
Project description:Clonal hematopoiesis (CH) results from enhanced fitness of a mutant hematopoietic stem and progenitor cell (HSPC), but how such clones expand is unclear. Here, we developed a technique that combines mosaic mutagenesis with color labeling of HSPCs to study how acquired mutations affect clonal fitness in a native environment. Mutations in CH-associated genes, like asxl1, promoted clonal dominance. Single-cell transcriptional analysis revealed that mutations stimulated expression of proinflammatory genes in mature myeloid cells and anti-inflammatory genes in progenitor cells of the mutant clone. Biallelic loss of one such immunomodulator, nr4a1, abrogated the ability of asxl1-mutant clones to establish clonal dominance. These results support a model where clonal fitness of mutant clones is driven by enhanced resistance to inflammatory signals from their mutant mature cell progeny.
2021-12-02 | GSE150373 | GEO
Project description:Clonal hematopoiesis (CH) results from enhanced fitness of a mutant hematopoietic stem and progenitor cell (HSPC), but how such clones expand is unclear. Here, we developed a technique that combines mosaic mutagenesis with color labeling of HSPCs to study how acquired mutations affect clonal fitness in a native environment. Mutations in CH-associated genes, like asxl1, promoted clonal dominance. Single-cell transcriptional analysis revealed that mutations stimulated expression of proinflammatory genes in mature myeloid cells and anti-inflammatory genes in progenitor cells of the mutant clone. Biallelic loss of one such immunomodulator, nr4a1, abrogated the ability of asxl1-mutant clones to establish clonal dominance. These results support a model where clonal fitness of mutant clones is driven by enhanced resistance to inflammatory signals from their mutant mature cell progeny.
2021-12-02 | GSE176036 | GEO
Project description:BACKGROUND: Our previous studies showed that RUNX1 and ASXL1 mutations were frequently co-existed in chronic myelomonocytic leukemia (CMML) and clonal evolution of RUNX1 and/or ASXL1 occurred most frequently in chronic myeloid leukemia (CML) with myeloid blastic crisis. The molecular pathogenesis of cooperation of RUNX1 and ASXL1 mutations has not been reported yet. METHODS: Lentiviral-mediated stable transduction of RUNX1-WT/MT (R135T) in K562 cells which harboring ASXL1-MT (Y591X). RNA was extracted from stable cell line and used for gene-expression microarray analysis. RESULTS: For in vitro study, we overexpressed RUNX1-WT/MT (R135T) in K562 cells which harboring ASXL1-MT (Y591X). We found that RUNX1-MT augmented cell proliferation, colony formation, HOXA gene expression and inhibited megakaryocytic differentiation in ASXL1-MT K562 cells compared to RUNX1-WT or empty vector control. We performed gene expression profile of K562 cells overexpressed with EV, RUNX1-WT and RUNX1-R135T mutation. Gene expression microarray data revealed that 147 genes upregulated more than 2-fold in RUNX1-R135T expressing K562 cells compared to EV control cells. From gene expression data analysis, we found that inhibitor of DNA binding 1 (ID1), a key transcriptional regulator of hematopoietic stem cell (HSC) lineage commitment, is upregulated in RUNX1-R135T-transduced K562 cells compared to EV and RUNX1-WT-expressing cells.
2018-06-01 | GSE99640 | GEO
Project description:Recurrent mutations in ASXL1 are found in various hematological malignancies and are associated with poor prognosis. In particular, ASXL1 mutations are frequently found in patients with hematological malignancies associated with myelodysplasia including myelodysplastic syndromes (MDS), and chronic myelomonocytic leukemia. Although loss-of-function ASXL1 mutations promote myeloid transformation, a large subset of ASXL1 mutations is thought to result in stable truncation of ASXL1. Here we demonstrate that C-terminal truncating ASXL1 mutations (ASXL1-MT) inhibit myeloid differentiation and induce MDS-like disease in mice, displaying all the features of human MDS including multi-lineage myelodysplasia, pancytopenia and occasional progression to overt leukemia. Concerning the molecular mechanisms, ASXL1-MT derepressed expression of Hoxa9 and miR-125a through inhibiting PRC2-mediated methylation of H3K27. miR-125a targeted expression of a surface receptor Clec5a, which was found to supports for myeloid differentiation. In addition, HOXA9 expression was high in MDS patients with ASXL1 mutations while Clec5a expression was generally low in MDS patients. Thus, ASXL1-MT induced MDS-like disease in mice via derepression of Hoxa9 and miR-125a, and Clec5a downregulation. Our data provide evidence for a novel axis of MDS pathogenesis (ASXL1 mutations-upregulation of HoxA9 and miR-125a-downregulation of Clec5a) and implicate both ASXL1 mutants and miR-125a as therapeutic targets in MDS.
2013-07-31 | GSE49118 | GEO
Project description:Recurrent mutations in ASXL1 are found in various hematological malignancies and are associated with poor prognosis. In particular, ASXL1 mutations are frequently found in patients with hematological malignancies associated with myelodysplasia including myelodysplastic syndromes (MDS), and chronic myelomonocytic leukemia. Although loss-of-function ASXL1 mutations promote myeloid transformation, a large subset of ASXL1 mutations is thought to result in stable truncation of ASXL1. Here we demonstrate that C-terminal truncating ASXL1 mutations (ASXL1-MT) inhibit myeloid differentiation and induce MDS-like disease in mice, displaying all the features of human MDS including multi-lineage myelodysplasia, pancytopenia and occasional progression to overt leukemia. Concerning the molecular mechanisms, ASXL1-MT derepressed expression of Hoxa9 and miR-125a through inhibiting PRC2-mediated methylation of H3K27. miR-125a targeted expression of a surface receptor Clec5a, which was found to supports for myeloid differentiation. In addition, HOXA9 expression was high in MDS patients with ASXL1 mutations while Clec5a expression was generally low in MDS patients. Thus, ASXL1-MT induced MDS-like disease in mice via derepression of Hoxa9 and miR-125a, and Clec5a downregulation. Our data provide evidence for a novel axis of MDS pathogenesis (ASXL1 mutations-upregulation of HoxA9 and miR-125a-downregulation of Clec5a) and implicate both ASXL1 mutants and miR-125a as therapeutic targets in MDS.
2013-07-31 | GSE49117 | GEO
Project description:Recurrent mutations in ASXL1 are found in various hematological malignancies and are associated with poor prognosis. In particular, ASXL1 mutations are frequently found in patients with hematological malignancies associated with myelodysplasia including myelodysplastic syndromes (MDS), and chronic myelomonocytic leukemia. Although loss-of-function ASXL1 mutations promote myeloid transformation, a large subset of ASXL1 mutations is thought to result in stable truncation of ASXL1. Here we demonstrate that C-terminal truncating ASXL1 mutations (ASXL1-MT) inhibit myeloid differentiation and induce MDS-like disease in mice, displaying all the features of human MDS including multi-lineage myelodysplasia, pancytopenia and occasional progression to overt leukemia. Concerning the molecular mechanisms, ASXL1-MT derepressed expression of Hoxa9 and miR-125a through inhibiting PRC2-mediated methylation of H3K27. miR-125a targeted expression of a surface receptor Clec5a, which was found to supports for myeloid differentiation. In addition, HOXA9 expression was high in MDS patients with ASXL1 mutations while Clec5a expression was generally low in MDS patients. Thus, ASXL1-MT induced MDS-like disease in mice via derepression of Hoxa9 and miR-125a, and Clec5a downregulation. Our data provide evidence for a novel axis of MDS pathogenesis (ASXL1 mutations-upregulation of HoxA9 and miR-125a-downregulation of Clec5a) and implicate both ASXL1 mutants and miR-125a as therapeutic targets in MDS. BM cells derived from mock-transplanted mice and ASXL1-MT transplanted mice were incubated with biotinylated antibodies for CD3e, B220, and TER-119, followed by incubation with streptavidin Micro Beads (Miltenyi Biotec). The marker-negative fraction was separated with LS Columns (Miltenyi Biotec). Using the sorted-BM cells, we compared the expression proliles between 3 sorted-BM cells with mock and 3 sorted-BM cells with ASXL1-MT. Total RNA was extracted by Trizol reagent (Invitrogen) according to the manufacturer’s protocol. Double-stranded cDNA was synthesized from 5 μg of total RNA with oligo (dT)24 T7 primer, amplified with T7 RNA polymerase up to approximately 50 μg of cRNA, and hybridized to Affymetrix Mouse Expression array 430A, which contains 45000 probe sets for 39000 transcripts and variants from over 34000 well-characterized mouse genes (Affymetrix). After washing and staining, the arrays were scanned on the GeneChip system confocal scanner (Affymetrix). The intensity for each feature of the array was captured with Affymetrix Microarray Suite (MAS) Version 5.0 software. Gene set enrichment analysis was performed by using Gene Ontology gene sets from the Molecular Signatures Database (http://www.broad.mit.edu/gsea/msigdb/).
2013-07-31 | E-GEOD-49118 | biostudies-arrayexpress
Project description:Recurrent mutations in ASXL1 are found in various hematological malignancies and are associated with poor prognosis. In particular, ASXL1 mutations are frequently found in patients with hematological malignancies associated with myelodysplasia including myelodysplastic syndromes (MDS), and chronic myelomonocytic leukemia. Although loss-of-function ASXL1 mutations promote myeloid transformation, a large subset of ASXL1 mutations is thought to result in stable truncation of ASXL1. Here we demonstrate that C-terminal truncating ASXL1 mutations (ASXL1-MT) inhibit myeloid differentiation and induce MDS-like disease in mice, displaying all the features of human MDS including multi-lineage myelodysplasia, pancytopenia and occasional progression to overt leukemia. Concerning the molecular mechanisms, ASXL1-MT derepressed expression of Hoxa9 and miR-125a through inhibiting PRC2-mediated methylation of H3K27. miR-125a targeted expression of a surface receptor Clec5a, which was found to supports for myeloid differentiation. In addition, HOXA9 expression was high in MDS patients with ASXL1 mutations while Clec5a expression was generally low in MDS patients. Thus, ASXL1-MT induced MDS-like disease in mice via derepression of Hoxa9 and miR-125a, and Clec5a downregulation. Our data provide evidence for a novel axis of MDS pathogenesis (ASXL1 mutations-upregulation of HoxA9 and miR-125a-downregulation of Clec5a) and implicate both ASXL1 mutants and miR-125a as therapeutic targets in MDS. Using 32Dcl3 cells transduced with pMYs-IG (mock) and pMYs-FLAG-ASXL1-MT-IG, we compared the expression profiles of 32Dcl3 cells with mock or ASXL1-MT under G-CSF stimulation at 4 time points, including 0hr (IL-3), 2hr, 6hr and 24hrs. Total RNA was extracted by Trizol reagent (Invitrogen) according to the manufacturer’s protocol. Double-stranded cDNA was synthesized from 5 μg of total RNA with oligo (dT)24 T7 primer, amplified with T7 RNA polymerase up to approximately 50 μg of cRNA, and hybridized to Affymetrix Mouse Expression array 430A, which contains 45000 probe sets for 39000 transcripts and variants from over 34000 well-characterized mouse genes (Affymetrix). After washing and staining, the arrays were scanned on the GeneChip system confocal scanner (Affymetrix). The intensity for each feature of the array was captured with Affymetrix Microarray Suite (MAS) Version 5.0 software. Gene set enrichment analysis was performed by using Gene Ontology gene sets from the Molecular Signatures Database (http://www.broad.mit.edu/gsea/msigdb/)
2013-07-31 | E-GEOD-49117 | biostudies-arrayexpress
Project description:Clonal Haematopoiesis-related Mutant ASXL1 Promotes Atherosclerosis in Mice via Dysregulated Innate Immunity
| PRJNA1172723 | ENA