Ligase4 is essential for hematopoietic stem cell maintenance
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE65195 | GEO | 2016/12/31
SECONDARY ACCESSION(S): PRJNA273382
REPOSITORIES: GEO
Similar Datasets
Project description:Quiescent hematopoietic stem cells (HSCs) are prone to mutagenesis, and accumulation of mutations can result in hematological malignancies. The mechanisms through which HSCs prevent such detrimental accumulation, however, are unclear. Here, we show that Aspp1 coordinates with p53 to maintain the genomic integrity of the HSC pool. Aspp1 is preferentially expressed in HSCs and restricts HSC pool size by attenuating self-renewal under steady state conditions. After genotoxic stress, Aspp1 promotes HSC cycling and induces p53-dependent apoptosis in cells with persistent DNA damage foci. Beyond these p53-dependent functions, Aspp1 attenuates HSC self-renewal and accumulation of DNA damage in p53-null HSCs. Consequently, concomitant loss of Aspp1 and p53 leads to the development of hematological malignancies, especially T-cell leukemia and lymphoma. Together, these data highlights coordination between Aspp1 and p53 in regulating HSC self-renewal and DNA damage tolerance, and suggest that HSCs possess specific mechanisms that prevent accumulation of mutations and malignant transformation. 8-week-old WT, Aspp1-/-, Mx1-Cre(+)p53flox/flox and Mx1-Cre(+)Aspp1-/-p53flox/flox mice were intraperitoneally administered with 400 μg pIpC five times every other day to obtain WT, Aspp1-/-, p53-/- and Aspp1-/-p53-/- bone marrow. 4 weeks after pIpC treatment, bone marrow lineage(-) Sca-1(+) cKit(+) cells were isolated. RNA was extracted and pooled from 3 independent mice per genotype. RNA samples were then amplified, labeled, and hybridized to independent arrays.
2015-05-20 | E-GEOD-69032 | biostudies-arrayexpress
Project description:Quiescent hematopoietic stem cells (HSCs) are prone to mutagenesis, and accumulation of mutations can result in hematological malignancies. The mechanisms through which HSCs prevent such detrimental accumulation, however, are unclear. Here, we show that Aspp1 coordinates with p53 to maintain the genomic integrity of the HSC pool. Aspp1 is preferentially expressed in HSCs and restricts HSC pool size by attenuating self-renewal under steady state conditions. After genotoxic stress, Aspp1 promotes HSC cycling and induces p53-dependent apoptosis in cells with persistent DNA damage foci. Beyond these p53-dependent functions, Aspp1 attenuates HSC self-renewal and accumulation of DNA damage in p53-null HSCs. Consequently, concomitant loss of Aspp1 and p53 leads to the development of hematological malignancies, especially T-cell leukemia and lymphoma. Together, these data highlights coordination between Aspp1 and p53 in regulating HSC self-renewal and DNA damage tolerance, and suggest that HSCs possess specific mechanisms that prevent accumulation of mutations and malignant transformation.
2015-05-20 | GSE69032 | GEO
Project description:Classical nonhomologous end-joining (C-NHEJ) repairs DNA double-stranded breaks (DSBs) throughout interphase but is thought to predominate in G1-phase when homologous recombination is unavailable. Complexes containing the Ku70/80 ("Ku") and XRCC4/Ligase IV (Lig4) core C-NHEJ factors are required, respectively, for sensing and joining DSBs. While such factors are exclusively required for joining RAG1/2-initiated DSBs during V(D)J recombination in G1-phase lymphocyte progenitors, cycling cells deficient for core C-NHEJ factors join chromosomal DSBs by alternative end-joining (A-EJ) pathways. Restriction of V(D)J recombination to C-NHEJ has been attributed to RAG-mediated exclusion of A-EJ; however, it remains unclear whether A-EJ is similarly excluded from more general DSBs in G1. Here, we report that Ku actively and robustly suppresses A-EJ of RAG1/2 and two classes of engineered endonuclease-mediated DSBs in G1-arrested progenitor B cell lines. Thus, while targeted DSBs remain as free broken ends in Lig4-deficient G1-arrested progenitor B cells, deletion of Ku70 in Lig4-deficient cells restores DSB rejoining and translocation to levels observed in Ku70-deficient counterparts. Correspondingly, while V(D)J recombination is abrogated in Ligase4-deficient lines, V(D)J-like joining occurs in Ku70-deficient and Ku70/Lig4 double-deficient lines through a translocation-based A-EJ mechanism. We conclude that in G1, Lig4-deficient progenitor B cells are functionally end-joining deficient due to a near complete Ku-dependent block in A-EJ. Thus, the differential impacts of Ku deficiency versus XRCC4/Ligase IV deficiency on V(D)J recombination, severity of neuronal apoptosis, and embryonic development, including Ku-deficiency rescuing Lig4-deficient embryonic lethality, may be explained by Ku-mediated inhibition of A-EJ in the G1 cell cycle phase.
2021-05-08 | GSE162453 | GEO
Project description:Aging of hematopoietic stem cells (HSCs) leads to several functional changes, including alterations affecting self-renewal and differentiation. While it is well established that many of the age-induced changes are intrinsic to HSCs, less is known about the stability of this state. Here, we entertained the hypothesis that HSC aging is driven by the acquisition of permanent genetic mutations. To examine this issue at a functional level in vivo, we applied induced pluripotent stem (iPS) cell reprogramming of aged hematopoietic progenitors and allowed the resulting aged-derived iPS cells to reform hematopoiesis via blastocyst complementation. Next, we functionally characterized iPS-derived HSCs in primary chimeras and following the transplantation of 're-differentiated' HSCs into new hosts; the gold standard to assess HSC function. Our data demonstrate remarkably similar functional properties of iPS-derived and endogenous blastocyst-derived HSCs, despite the extensive chronological and proliferative age of the former. Our results therefore favor a model in which an underlying, but reversible, epigenetic component is a hallmark of HSC aging rather than being driven by an increased DNA mutation burden. Hematopoietic stem cells (HSC) have been sorted out from young and aged steady-state mice, and from recipients transplanted with young and aged bone marrow. Generated iPS and commercially available ES cells were also sorted and analyzed.
2013-03-06 | E-GEOD-44923 | biostudies-arrayexpress
Project description:Precise study of HSCs during regeneration has been impeded by the rarity of the HSC population and depletion of phenotypic HSCs early following genotoxic stresses, such as total body irradiation (TBI). We isolated bone marrow (BM) ckit+sca-1+lin- (KSL) cells, which are enriched for HSCs, from adult C57Bl6 mice before and at several time points following TBI, as a means to map the dynamic molecular response of HSC regeneration. We isolated BM KSL cells and myeloid progenitor cells (c-kit+sca-1-lin- cells) at day +14 after irradiation and compared the gene expression profile of regenerating HSCs versus steady state HSCs (non-irradiated) and committed progenitor cells.
2016-04-05 | E-GEOD-79744 | biostudies-arrayexpress
Project description:Defining mechanism(s) that maintain tissue stem quiescence is important for improving tissue regeneration, cell therapies, aging, and cancer. We report here that genetic ablation of Id2 in adult hematopoietic stem cells (HSCs) promotes increased HSC activation and differentiation, which results in HSC exhaustion and bone marrow failure over time. Id2Δ/Δ HSCs show increased HSC cycling, reactive oxygen species (ROS) production, mitochondrial activation, and DNA damage supporting the conclusion that Id2Δ/Δ HSCs are less quiescent. Mechanistically, HIF-1α expression is decreased in Id2Δ/Δ HSCs, and stabilization of HIF-1α in Id2Δ/Δ HSCs restores HSC quiescence and rescues HSC exhaustion. ID2 promotes HIF-1α expression by binding to the Von Hippel-Lindau (VHL) protein and interfering with proteasomal degradation of HIF-1α. HIF-1α promotes Id2 expression and enforces a positive feedback loop between ID2 and HIF-1α to maintain HSC quiescence. Thus, sustained ID2 expression could protect HSCs during stress, and improve HSC expansion for gene editing and cell therapies.
2022-05-31 | GSE203076 | GEO
Project description:The importance of the p53 protein in the cellular response to DNA damage is well known, but its function during steady-state hematopoiesis has not been established. We have defined a critical role of p53 in regulating hematopoietic stem cell quiescence, especially in promoting the enhanced quiescence seen in HSCs that lack the MEF/ELF4 transcription factor. Transcription profiling of HSCs isolated from wild type and p53 null mice identified Gfi-1 and Necdin as p53 target genes and using lentiviral vectors to upregulate or knockdown the expression of these genes, we show their importance in regulating HSC quiescence. Establishing the role of p53 (and its target genes) in controlling the cell cycle entry of HSCs may lead to therapeutic strategies capable of eliminating quiescent cancer (stem) cells. Experiment Overall Design: RNAs isolated from wild type, p53 -/- and p53 -/- Mef -/- LSK cells were used in oligonucleotide arrays (Affymetrix)
2008-11-15 | E-GEOD-13448 | biostudies-arrayexpress
Project description:Hematopoietic aging is associated with decreased hematopoietic stem cell (HSC) self-renewal capacity and increased risk for myelodysplasia and leukemia. Deficient DNA repair contributes to the decline in HSC self-renewal capacity during aging and it remains unclear whether extrinsic signals can rejuvenate aged HSCs. Here, we demonstrate that augmentation of non-homologous end-joining (NHEJ) DNA repair in aged HSCs via treatment with epidermal growth factor (EGF) rejuvenates HSC function. Seven day culture of BM CD34-ckit+sca-1+lin- (34-KSL) HSCs from aged C57BL/6 mice with EGF suppressed myeloid skewing and increased production of multipotent CFU-granulocyte, erythroid, monocyte and megakaryocyte (CFU-GEMM) colonies. Aged, EGF-treated HSCs displayed increased donor multilineage engraftment in primary competitively transplanted mice and in secondary mice compared to mice transplanted with aged, control HSCs. Donor cell engraftment within the bone marrow (BM) KSL and SLAM+KSL HSC population was > 2-fold increased in mice transplanted with aged, EGF-treated HSCs. Systemic administration of EGF to aged mice for 6 weeks also increased long term – HSC self-renewal capacity as measured by increased donor bone marrow (BM) competitive repopulation in primary and secondary transplanted mice. Conversely, deletion of EGFR in Scl/Tal1+ hematopoietic cells was associated with increased myeloid skewing and depletion of LT-HSCs in middle aged mice. Mechanistically, EGF treatment decreased DNA damage in aged HSCs through activation of DNA PK-cs, Artemis and NHEJ repair. Inhibition of DNA PK-cs blocked EGF-mediated restoration of multipotent differentiation and suppression of myeloid skewing in aged HSCs, suggesting that the restoration of hematopoietic potential in aged HSCs is dependent on EGF-mediated activation of DNA PK-cs. EGF treatment also converted the transcriptome of aged HSCs from enrichment for genes involved in cell death and survival to genes involved in HSC generation and identity. These data suggest that extrinsic activation of EGFR signaling can restore key functional capacities in aged HSCs.
2024-04-01 | GSE252293 | GEO
Project description:Defining mechanism(s) that maintain tissue stem quiescence is important for improving tissue regeneration, cell therapies, aging, and cancer. We report here that genetic ablation of Id2 in adult hematopoietic stem cells (HSCs) promotes increased HSC activation and differentiation, which results in HSC exhaustion and bone marrow failure over time. Id2Δ/Δ HSCs show increased cycling, reactive oxygen species (ROS) production, mitochondrial activation, ATP production, and DNA damage compared to Id2+/+ HSCs, supporting the conclusion that Id2Δ/Δ HSCs are less quiescent. Mechanistically, HIF-1α expression is decreased in Id2Δ/Δ HSCs, and stabilization of HIF-1α in Id2Δ/Δ HSCs restores HSC quiescence and rescues HSC exhaustion. ID2 promotes HIF-1α expression by binding to the Von Hippel-Lindau (VHL) protein and interfering with proteasomal degradation of HIF-1α. HIF-1α promotes Id2 expression and enforces a positive feedback loop between ID2 and HIF-1α to maintain HSC quiescence. Thus, sustained ID2 expression could protect HSCs during stress, and improve HSC expansion for gene editing and cell therapies.
2022-05-31 | GSE205102 | GEO
Project description:Hematopoietic stem cells (HSCs) balance self-renewal and differentiation to maintain hematopoietic fitness throughout life. In steady-state conditions, HSC exhaustion is prevented by the maintenance of most HSCs in a quiescent state, with cells entering the cell cycle only occasionally. HSC quiescence is regulated by retinoid and fatty-acid ligands of transcriptional factors of the nuclear retinoid X receptor (RXR) family. Here, we show that dual deficiency for hematopoietic RXRa and RXRb induces HSC exhaustion, myeloid cell/megakaryocyte differentiation, and myeloproliferative-like disease. RXRa and RXRb maintain HSC quiescence, survival, and chromatin compaction; moreover, transcriptome changes in RXRa;RXRb-deficient HSCs include premature acquisition of an aging-like HSC signature, MYC pathway upregulation, and RNA intron retention. Fitness loss and associated RNA transcriptome and splicing alterations in RXRa;RXRb-deficient HSCs are prevented by Myc haploinsufficiency. Our study reveals the critical importance of RXRs for the maintenance of HSC fitness and their protection from premature aging.
2022-11-11 | GSE191162 | GEO