Asparagine availability controlsgerminal centre B cell homeostasis
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ABSTRACT:
PROVIDER: PRJNA951723 | ENA |
REPOSITORIES: ENA
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Project description:Germinal centre (GC) B cells proliferate at some of the highest rates of any mammalian cell. Yet the metabolic processes which enable this are poorly understood. We performed integrated metabolomic and transcriptomic profiling of GC B cells, and found that asparagine metabolism is highly upregulated. Asparagine is conditionally essential to B cells, and its synthetic enzyme, asparagine synthetase (ASNS) is markedly upregulated following their activation, through the integrated stress response sensor general control non-derepressible 2 (GCN2). When Asns is deleted, B cell survival in low asparagine conditions is severely impaired. Using stable isotope tracing, we found that metabolic adaptation to the absence of asparagine requires ASNS, and that the synthesis of nucleotides is particularly sensitive to asparagine deprivation. Conditional deletion of Asns in B cells selectively impairs GC formation, associated with a reduction in RNA synthesis rates. Finally, removal of environmental asparagine by asparaginase was found to also severely compromise the GC reaction.
2024-04-03 | GSE228845 | GEO
Project description:Single - cell profiling of patient tumours and of mouse models is revealing that many cancers are constituted of communities of genetically and phenotypically distinct clonal lineages 1 - 12. A functional model of breast cancer heterogeneity revealed that clonal sub - populations proficient at generating circulating tumour cells were not equally capable of forming metastases at secondary sites 13. A combination of differential expression and focused in vitro and in vivo RNAi screens revealed candidate drivers of metastasis discriminating these clones, which were then evaluated in gene expression datasets from breast cancer patients. Among these, Asparagine Synthetase (Asns) expression in a patient's primary tumour was most strongly correlated with later metastatic relapse. Silencing of Asns reduced both metastatic potential in vivo and invasive potential in vitro. Conversely, increasing the availability of extracellular asparagine increased the invasive potential of mouse and human breast cancer cells, and enforced Asns expression promoted metastasis. Decreasing asparagine availability in mice by treatment with L-asparaginase or even by dietary restriction strongly reduced metastasis from orthotopic tumours. Asparagine availability varies betwe en tissues, potentially explaining selective effects on particular steps of tumor progression. Asparagine limitation reduced the production of proteins that promote the epithelial to mesenchymal transition, providing one potential mechanism for how the availability of a single amino acid could regulate metastatic progression.
2018-02-08 | GSE107109 | GEO
Project description:Asparagine availability governs metastasis in a model of breast cancer
| PRJNA419005 | ENA
Project description:Adequate availability of the non-essential amino acid asparagine is necessary to support growth and survival of sarcoma cells. The three top pathways enriched among transcripts upregulated in asparagine-depleted cells included ribosome, aminoacyl tRNA biosynthesis and oxidative phosphorylation.
2022-06-20 | GSE153991 | GEO
Project description:Amino acid availability is a crucial factor for survivability of cancer cells. Colorectal cancer cells have been shown to resist asparagine depletion by utilizing GSK3-dependent proteasomal degradation, termed Wnt-dependent stabilization of proteins (Wnt/STOP), to replenish their amino acid pool. Inhibition of GSK3a halts the sourcing of amino acids, which subsequently leads to cancer cell vulnerability towards asparaginase therapy. Leveraging RNA sequencing we show that GSK3a inhibition leads to a significant enrichment of ribosomal transcripts amongst transcripts that are differentially downregulated in asparaginase treated Rspo3 fusion positive colorectal cancer cell organoids.
2023-09-13 | GSE234801 | GEO
Project description:Osteolytic lesions with suppression of osteoblastic (OB) differentiation are hallmarks of multiple myeloma (MM). Most recently, Gln availability has been found to be essential to sustain bone mass formation in murine models. On the other hand, MM cells are Gln-addicted and consume huge amounts of the amino acid, leading to a partial Gln depletion in the bone marrow (BM) plasma. We hypothesize that MM-dependent Gln depletion contributes to the defective OB differentiation characteristic of MM. Conversely, GLS (both KGA and GAC isoforms) and SLC38A2, the gene for the concentrative Gln transporter SNAT2, were induced. Consistent with this conclusion, the activity of SNAT2 was absent in undifferentiated hMSCs but well detectable after 14 days of OB differentiation, when total Gln uptake was also increased. Under the same conditions, OB differentiation markers (RUNX2, COL1A1, ALPL expression and ALPL activity or staining) were significantly induced but their expression was blunted by incubation in low-Gln (0.4 mM) medium or in the presence of the SNAT2 inhibitor MeAIB. The incubation in Gln-free D-MEM suppressed the induction of GLS and SLC38A2 along with OB differentiation, which was restored by the supplementation of Non-Essential Amino Acids (NEAA). Among NEAA, only asparagine (Asn) was able to rescue OB differentiation in the absence of Gln. The determination of intracellular amino acids with MS indicated that OB differentiation was associated with the increase of cell Asn, without significant changes of Gln, glutamate (Glu) or aspartate (Asp). Asparagine Synthetase (ASNS), the Gln-dependent enzyme that accounts for Asn synthesis, was also found induced during OB differentiation of hMSCs. Gene Expression Profiles of primary BM hMSCs and OBs from bone biopsies of both healthy donors and MM patients indicated that GLS, ASNS, and SLC38A2 are more expressed in OBs, while the expression of GLUL, the gene for GS, is higher in undifferentiated hMSCs from healthy donors. Overall, these results indicate that (1) OB differentiation of hMSCs is Gln-dependent; (2) the partial Gln depletion, imposed by Gln-addicted MM cells in the BM microenvironment, contributes to the impairment of osteoblastic differentiation of hMSCs; (3) hindrance of differentiation may depend on the limited availability of intracellular Asn derived from Gln-dependent ASNS. These results support the evidence that Gln addiction of MM cells affects bone microenvironment leading to the inhibition of OB differentiation and, consequently, to the development of MM bone disease.
2020-12-01 | GSE147791 | GEO
Project description:Glutamine addicted myeloma cells inhibits osteoblastic differentiation of bone marrow mesenchymal stromal cells limiting asparagine availability.
| PRJNA616375 | ENA
Project description:Asparagine synthetase (ASNS) is a gene on the long arm of chromosome 7 that is copy number amplified in the majority of glioblastomas. ASNS copy number amplification is associated with a significantly decreased survival. Using patient-derived glioma stem cells (GSCs), we showed significant metabolic alterations occur in gliomas when perturbing the expression of asparagine synthetase, which is not merely restricted to amino acid homeostasis. ASNS-high GSCs maintained a slower basal metabolic profile yet readily shifted to a greatly increased capacity for glycolysis and oxidative phosphorylation when needed. This led ASNS-high cells to a greater ability to proliferate and spread into brain tissue. Finally, we demonstrate that these changes confer resistance to cellular stress, notably oxidative stress, through adaptive redox homeostasis which led to radiation resistance. Furthermore, ASNS overexpression led to modifications of the one-carbon metabolism to promote a more antioxidant tumor environment revealing a metabolic vulnerability that may be therapeutically exploited.
2021-08-18 | GSE171163 | GEO
Project description:We will report the gene expression changes following asparagine depletion in human ALL cell line, RS4;11
2019-08-06 | GSE135420 | GEO
Project description:Transcriptomics in grain of high and low asparagine wheat genotypes in response to sulphur availability
| PRJEB31122 | ENA