Cited by 161Acute Myeloid Leukemia ResearchHematopoietic Stem Cell TransplantationBlood disorders and treatments

Aging drives Tet2 +/− clonal hematopoiesis via IL-1 signaling

Open access
Caiado, Francisco, Kovtonyuk, Larisa V., Gonullu, Nagihan G., Fullin, Jonas, Boettcher, Steffen, Manz, Markus G.·2023·Blood

Abstract

Clonal hematopoiesis of indeterminate potential (CHIP), also referred to as aging-related clonal hematopoiesis, is defined as an asymptomatic clonal expansion of mutant mature hematopoietic cells in ≥4% of blood leukocytes. CHIP associates with advanced age and increased risk for hematological malignancy, cardiovascular disease, and all-cause mortality. Loss-of-function somatic mutations in TET2 are frequent drivers of CHIP. However, the contribution of aging-associated cooperating cell-extrinsic drivers, like inflammation, remains underexplored. Using bone marrow (BM) transplantation and newly developed genetic mosaicism (HSC-SCL-Cre-ERT; Tet2+/flox; R26+/tm6[CAG-ZsGreen1]Hze) mouse models of Tet2+/−driven CHIP, we observed an association between increased Tet2+/− clonal expansion and higher BM levels of the inflammatory cytokine interleukin-1 (IL-1) upon aging. Administration of IL-1 to mice carrying CHIP led to an IL-1 receptor 1 (IL-1R1)–dependent expansion of Tet2+/− hematopoietic stem and progenitor cells (HSPCs) and mature blood cells. This expansion was caused by increased Tet2+/− HSPC cell cycle progression, increased multilineage differentiation, and higher repopulation capacity compared with their wild-type counterparts. In agreement, IL-1α–treated Tet2+/− hematopoietic stem cells showed increased DNA replication and repair transcriptomic signatures and reduced susceptibility to IL-1α–mediated downregulation of self-renewal genes. More important, genetic deletion of IL-1R1 in Tet2+/− HPSCs or pharmacologic inhibition of IL-1 signaling impaired Tet2+/− clonal expansion, establishing the IL-1 pathway as a relevant and therapeutically targetable driver of Tet2+/− CHIP progression during aging.

AI snapshot

Written from the paper’s full text.

TL;DR

Aging promotes Tet2+/− clonal hematopoiesis in mice through increased bone marrow IL-1, which acts directly on Tet2+/− HSPCs via IL-1R1 to enhance proliferation, multilineage differentiation, and clonal dominance. Genetic or pharmacologic blockade of IL-1–IL-1R1 signaling reduces Tet2+/− clonal expansion during aging.

Key findings

  • In an inducible, transplantation-independent Tet2+/− mosaicism model, Tet2+/− clones expanded significantly more than WT clones during aging; the increase in monthly expansion rates became significant from 7 months onward, particularly at 7-8, 9-10, and 11-12 months, and occurred across T cells, B cells, myeloid cells, erythrocytes, and multiple HSPC populations.
  • Aged Tet2+/− BM showed increased IL-1α/β and TNF-α gene expression, increased IL-1α protein, and a positive correlation between BM Tet2+/− clonal size and IL-1α concentration; Tet2+/− myeloid cells were the main IL-1α producers, especially after LPS exposure.
  • IL-1α exposure for 14 days in young mice significantly increased the Tet2+/− clonal fraction in PB and HSPCs, whereas Tet2+/−; Il1r1−/− cells showed no expansion; IL-1β had a similar but lower-magnitude effect. Genetic IL-1R1 ablation completely abrogated Tet2+/− expansion in transplantation chimeras, and anakinra reduced PB Tet2+/− clonal expansion but did not fully prevent HSPC clonal expansion.
  • RNA-seq of HSCs after IL-1α showed 318 DEGs unique to Tet2+/− HSCs, 221 unique to WT HSCs, and 515 shared; Tet2+/− HSCs were enriched for DNA replication, cell cycle progression, and DNA repair pathways, while 9 self-renewal genes (e.g., Mecom, Hmox1, Plag1) were downregulated exclusively in IL-1α–treated WT HSCs.

Methods

  • Used triple-transgenic mice (HSC-SCL-Cre-ERT; Tet2+/flox; R26+/tm6(CAG-ZsGreen1)Hze) and WT controls, with tamoxifen titration to generate about 10% or ≈2% ZsG+ clonal fractions; mice were aged up to 12 or 28 months, exposed to IL-1α/IL-1β, or treated with anakinra (37 μg/mouse every other day from 11 to 13 months).
  • Also used BM transplantation chimeras, including 90:10 and 50:50 competition settings, with WT, Tet2+/−, Il1r1−/−, and Tet2+/−; Il1r1−/− donor cells.
  • Main assays included flow cytometry for PB/BM lineages and HSPCs, cell cycle analysis, methylcellulose colony-forming/replating assays, bulk RNA-seq of HSCs, and statistics by Student t-test or 2-way ANOVA with Tukey correction in Prism v8.

Limitations

  • Stated: the exact molecular mechanisms by which Tet2+/− HSCs show differential differentiating and self-renewing proliferative responses to IL-1 remain to be elucidated; whether IL-1 dependency is exclusive to TET2-mutant AML remains to be determined; and whether additional age-associated mutations such as FLT3 synergize with Tet2 loss and IL-1R1 remains to be determined.
  • Stated: the anakinra regimen used did not fully prevent Tet2+/− HSPC clonal expansion, suggesting the dose and timing were insufficient to revert established clonal dominance; reversion may require combination therapy.
  • Evident from the text: the causal experiments are in murine models, with human relevance inferred from cited CHIP and canakinumab data rather than directly tested here; the inducible model also showed ZsG leakiness up to 2.5% at 10 months, and transplantation models had an early post-irradiation expansion phase not seen in the inducible model.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1182/blood.2022016835

Cites

60 of 60 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

61 of 73 cited sources checked · 14 supported · 2 flagged · accuracy not yet measured

  • Findingcitation

    In BM chimeras, Tet2+/− PB CD45.2+ cells show increased repopulating capacity compared with WT in the PBS groups.

    “As previously reported, we observed increased repopulating capacity in Tet2+/− PB CD45.2+ compared with WT in the PBS groups.11, 12, 13”
    Quote in the paperSubstantial claim1 of 3 sources checked
    • cites [11] Ko, 2011, Ten-eleven-translocation 2 (TET2) negatively regulates homeostasis and differentiation of hematopoietic stem cells in mice, Proc Natl Acad Sci U S A source
    • cites [12] Moran-Crusio, 2011, Tet2 loss leads to increased hematopoietic stem cell self-renewal and myeloid transformation, Cancer Cell source

      The Results section, “Tet2 haploinsufficiency is sufficient to initiate aberrant hematopoiesis in vitro and in vivo” (page not supplied), reports that Tet2+/− cells outcompeted wild-type cells in competitive reconstitution experiments, supporting the increased repopulating-capacity comparison. The Bone marrow transplantation procedures identify heterozygous and wild-type cells as CD45.2+, but describe polyI-polyC-induced deletion, not a PBS-treated comparison group. PBS appears there as a cell-preparation buffer, so the PBS-group qualifier is not supported by this copy. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [13] Quivoron, 2011, TET2 inactivation results in pleiotropic hematopoietic abnormalities in mouse and is a recurrent event during human lymphomagenesis, Cancer Cell source
  • Premisecitation

    Tet2-deficient HSPCs maintain a repopulation advantage after exposure to bacterial lipopolysaccharides due to increased resistance to IL-6-mediated apoptosis.

    “Moreover, Tet2-deficient HSPCs maintain a repopulation advantage after exposure to bacterial lipopolysaccharides (LPSs), due to increased resistance to IL-6–mediated apoptosis,16”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [16] Cai, 2018, Inhibition of inflammatory signaling in Tet2 mutant preleukemic cells mitigates stress-induced abnormalities and clonal hematopoiesis, Cell Stem Cell source

      The Results section on repopulating activity (page unavailable) reports that Tet2-KO HSPCs maintain greater engraftment than wild-type cells after LPS challenge; the apoptosis Results section reports less apoptosis in Tet2-KO cells after LPS. But the IL-6 experiments report reduced apoptosis of Tet2-KO cells in the presence of IL-6, not resistance to apoptosis mediated by IL-6. The claim’s proposed mechanism therefore misstates what the paper shows. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
  • Premisecitation

    Tet2-deficient HSPCs show enhanced proliferation and differentiation in response to microbial-induced IL-6.

    “Indeed, Tet2-deficient HSPCs show enhanced proliferation and differentiation in response to microbial-induced interleukin-6 (IL-6)14 and in response to tumor necrosis factor-α (TNF-α).15”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [14] Meisel, 2018, Microbial signals drive pre-leukaemic myeloproliferation in a Tet2-deficient host, Nature source
  • Premisecitation

    Most CHIP mouse models rely on BM transplantation following high-dose irradiation and inevitably increased inflammatory milieus.

    “Currently, most CHIP mouse models rely on BM transplantation following high-dose irradiation and inevitably increased inflammatory milieus.16,24,39”
    Quote in the paperSubstantial claim3 of 3 sources checked
    • cites [16] Cai, 2018, Inhibition of inflammatory signaling in Tet2 mutant preleukemic cells mitigates stress-induced abnormalities and clonal hematopoiesis, Cell Stem Cell source

      The STAR*METHODS Method Details section (page not supplied) says this paper’s bone-marrow transplantation recipients were lethally irradiated before transplantation, supporting the claim for this model. The paper does not establish that most CHIP mouse models use this approach or that irradiation inevitably increases the inflammatory milieu. (LLM, conf=0.85)

      Experimental — accuracy not yet measured
    • cites [24] Fuster, 2017, Clonal hematopoiesis associated with TET2 deficiency accelerates atherosclerosis development in mice, Science source

      The passage labeled Abstract (page not provided) describes this CHIP mouse model using bone marrow transplantation into lethally irradiated recipients. It does not establish that most CHIP mouse models use this approach or that irradiation inevitably increases the inflammatory milieu; its inflammatory findings concern TET2 deficiency. (LLM, conf=0.87)

      Experimental — accuracy not yet measured
    • cites [39] Sano, 2018, Tet2-mediated clonal hematopoiesis accelerates heart failure through a mechanism involving the IL-1β/NLRP3 inflammasome, J Am Coll Cardiol source

      The Results describe this paper’s CHIP model as bone-marrow transplantation into lethally irradiated mice. They do not establish that most CHIP mouse models use this approach or that irradiation inevitably increases the inflammatory milieu; the reported inflammatory changes were measured after myocardial infarction in Tet2-deficient mice relative to transplanted controls. The Methods also describe a conditional myeloid-restricted model. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
  • Premisecitation

    Increased IL-1 BM level is a hallmark of hematopoietic inflammaging in mice.

    “Increased IL-1 BM level, produced by different cellular sources, is a hallmark of hematopoietic inflammaging in mice.21,22,42”
    Quote in the paperSubstantial claim3 of 3 sources checked
    • cites [21] Frisch, 2019, Aged marrow macrophages expand platelet-biased hematopoietic stem cells via interleukin-1B, JCI Insight source
    • cites [22] Pioli, 2019, Plasma cells are obligate effectors of enhanced myelopoiesis in aging bone marrow, Immunity source

      The Discussion reports an age-dependent increase in Il1b expression in bone-marrow stroma and identifies plasma cells as another potential IL-1 source in old mice. This supports the link between IL-1 and hematopoietic inflammaging, but the cited passages do not establish an increased IL-1 protein level in bone marrow. (LLM, conf=0.83)

      Experimental — accuracy not yet measured
    • cites [42] Helbling, 2019, Global transcriptomic profiling of the bone marrow stromal microenvironment during postnatal development, aging, and inflammation, Cell Rep source

      The ‘Increased Pro-inflammatory Signatures in Aged BM Stroma’ section reports increased Il1b expression in bone marrow stromal cells of aged mice and an enhanced inflammatory milieu. It does not establish increased IL-1 protein levels throughout the bone marrow or show production by different cellular sources. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
  • Classified as probably not a substantial claim. 18
  • May combine two claims. 40
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    TET2 mutations are the most frequent single-gene mutations in myelodysplastic syndrome.

    “Moreover, TET2 mutations are the most frequent single-gene mutations in myelodysplastic syndrome (MDS), an age-related hematopoietic stem and progenitor cell (HSPC) disease.9”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [9] Nazha, 2021, Personalized prediction model to risk stratify patients with myelodysplastic syndromes, J Clin Oncol source

      The mutation table in the indexed copy (section labeled “Validations of the New Model in Different Settings”; page unavailable) lists SF3B1 in 369 patients and TET2 in 363. The paper identifies TET2 as commonly mutated, but its cohort data do not make it the most frequent single-gene mutation. (LLM, conf=0.86)

      Checked by a reasoning model — may be wrong.

      Experimental — accuracy not yet measured
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    CHIP carriers have increased risk of all-cause mortality, largely due to cardiovascular disease and stroke.

    “CHIP carriers have an about 13-fold increased risk of developing myeloid hematological malignancies and an increased risk of all-cause mortality, largely due to cardiovascular disease and stroke.1, 2, 3, 4”
    Quote in the paperNot a substantial claim4 of 4 sources checked
    • cites [1] Genovese, 2014, Clonal hematopoiesis and blood-cancer risk inferred from blood DNA sequence, N Engl J Med source

      The Results section reports increased all-cause mortality among participants with clonal hematopoiesis (hazard ratio, 1.4). But it says the reduced survival in this cohort was explained by cancer deaths and an association with smoking, contrary to the claim that it was largely due to cardiovascular disease and stroke. Page numbers are unavailable in our copy. (LLM, conf=0.88)

      Checked by a reasoning model — may be wrong.

      Experimental — accuracy not yet measured
    • cites [2] Jaiswal, 2014, Age-related clonal hematopoiesis associated with adverse outcomes, N Engl J Med source

      The Results section on overall survival reports increased all-cause mortality and a higher risk of cardiovascular death among people with mutations. The cardiometabolic Results section reports increased incidence of ischemic stroke, but the Discussion says the excess mortality *may* be related to coronary heart disease and stroke. The paper does not establish that mortality was largely due to those conditions or identify stroke as a major cause of death. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [3] Xie, 2014, Age-related mutations associated with clonal hematopoietic expansion and malignancies, Nat Med source

      The Results section on cancer types and sample characteristics notes that 22.1% of participants were deceased at sample procurement, but does not compare mortality in carriers and noncarriers. Searches for all-cause mortality, cardiovascular disease, stroke, and survival found no passage addressing the attributed risk or causes of death. (LLM, conf=0.76)

      Experimental — accuracy not yet measured
    • cites [4] Jaiswal, 2019, Clonal haematopoiesis: connecting ageing and inflammation in cardiovascular disease, Nat Rev Cardiol source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    CHIP carriers have about a 13-fold increased risk of developing myeloid hematological malignancies.

    “CHIP carriers have an about 13-fold increased risk of developing myeloid hematological malignancies and an increased risk of all-cause mortality, largely due to cardiovascular disease and stroke.1, 2, 3, 4”
    Quote in the paperNot a substantial claim4 of 4 sources checked
    • cites [1] Genovese, 2014, Clonal hematopoiesis and blood-cancer risk inferred from blood DNA sequence, N Engl J Med source

      The Results section ('Clonal Hematopoiesis and Subsequent Hematologic Cancer and Death'; page not provided) reports a hazard ratio of 12.9 for subsequent hematologic cancer in participants with clonal hematopoiesis. That supports the approximately 13-fold figure, but the estimate is for hematologic cancers overall, not specifically myeloid malignancies. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [2] Jaiswal, 2014, Age-related clonal hematopoiesis associated with adverse outcomes, N Engl J Med source

      The Results section (“Association of Somatic Mutations with the Risk of Hematologic Cancer”; page not provided) reports an 11.1-fold higher risk in people with detectable mutations. It does not report a 13-fold estimate specifically for myeloid malignancies; its estimate covers hematologic cancers more broadly. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [3] Xie, 2014, Age-related mutations associated with clonal hematopoietic expansion and malignancies, Nat Med source

      The Discussion (page not provided) says clonal hematopoietic changes may contribute to hematologic malignancies, but it does not report a 13-fold risk. It explicitly says the researchers could not determine whether participants with leukemia-associated mutations later developed a malignant hematologic disease. (LLM, conf=0.85)

      Experimental — accuracy not yet measured
    • cites [4] Jaiswal, 2019, Clonal haematopoiesis: connecting ageing and inflammation in cardiovascular disease, Nat Rev Cardiol source

      The Clinical associations of CHIP section reports an approximately tenfold increased risk of haematological cancer in CHIP carriers and says most cancers that develop are myeloid. It does not report a 13-fold estimate specifically for myeloid malignancies. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Loss-of-function heterozygous mutations in TET2 account for about 10% to 30% of mutations found in CHIP carriers.

    “Loss-of-function heterozygous mutations in epigenetic regulators DNMT3A (cytosine methyltransferase) and TET2 (methylcytosine dioxygenase) are the most frequently detected mutations in CHIP, accounting for about 50% to 60% and 10% to 30% of mutations found in CHIP carriers, respectively.1, 2, 3,7,8”
    Quote in the paperNot a substantial claim5 of 5 sources checked
    • cites [1] Genovese, 2014, Clonal hematopoiesis and blood-cancer risk inferred from blood DNA sequence, N Engl J Med source

      The Results section (page unavailable) reports 31 TET2 mutations among 327 candidate driver mutations in participants with clonal hematopoiesis—about 9.5%, consistent with the claim’s approximate lower bound. It describes TET2 mutations as tending to disrupt protein-coding sequences, but does not establish that all 31 were loss-of-function heterozygous mutations or support a proportion approaching 30%. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
    • cites [2] Jaiswal, 2014, Age-related clonal hematopoiesis associated with adverse outcomes, N Engl J Med source

      The Results section reports 72 TET2 variants among 805 detected mutations—about 9%—and cautions that TET2 mutations were probably undercounted because only about half the coding region was captured. It supports TET2 as a frequently mutated gene in clonal hematopoiesis, but does not establish a 10%–30% share or identify those variants collectively as heterozygous loss-of-function mutations. The indexed copy provides no page numbers for these passages. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [3] Xie, 2014, Age-related mutations associated with clonal hematopoietic expansion and malignancies, Nat Med source

      The Results (page unavailable) report TET2 mutations in 9 of 58 cases with blood-specific mutations, a proportion within the claimed 10%–30% range, and give examples of TET2 frameshift and nonsense mutations. However, the paper does not establish that all TET2 mutations counted were heterozygous loss-of-function mutations, so it does not support that more specific percentage claim. (LLM, conf=0.83)

      Experimental — accuracy not yet measured
    • cites [7] Buscarlet, 2017, DNMT3A and TET2 dominate clonal hematopoiesis and demonstrate benign phenotypes and different genetic predispositions, Blood source

      The Prevalence of mutations section identifies TET2 as one of the most frequently affected genes, but reports 33.3% (134/402) of documented mutations, above the claimed 10%–30% range. The Type of mutations section lists truncating and other TET2 variants, but does not establish that heterozygous loss-of-function TET2 mutations account for the claimed proportion. Page numbers are unavailable in our copy. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [8] Fabre, 2022, The longitudinal dynamics and natural history of clonal haematopoiesis, Nature source

      The Mutational landscape of clonal haematopoiesis section says TET2 and DNMT3A mutations were the most common in the studied cohort. It does not give the claimed 10%–30% share for TET2 mutations in CHIP carriers or establish that those mutations were heterozygous loss-of-function mutations. The Determinants of clonal growth rate section discusses truncating and missense TET2 mutations but does not establish those qualifiers or the percentage. (LLM, conf=0.83)

      Experimental — accuracy not yet measured
  • May combine two claims.

    Premisecitation

    Tet2 loss of function in murine HSPCs leads to increased self-renewal and pool expansion, higher competitive repopulation capacity, and a predisposition to hematological malignancy development.

    “Indeed, Tet2 loss of function in murine HSPCs leads to increased self-renewal and pool expansion, higher competitive repopulation capacity, and a predisposition to hematological malignancy development.11, 12, 13”
    Quote in the paperSubstantial claim1 of 3 sources checked
    • cites [11] Ko, 2011, Ten-eleven-translocation 2 (TET2) negatively regulates homeostasis and differentiation of hematopoietic stem cells in mice, Proc Natl Acad Sci U S A source
    • cites [12] Moran-Crusio, 2011, Tet2 loss leads to increased hematopoietic stem cell self-renewal and myeloid transformation, Cancer Cell source
    • cites [13] Quivoron, 2011, TET2 inactivation results in pleiotropic hematopoietic abnormalities in mouse and is a recurrent event during human lymphomagenesis, Cancer Cell source
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Advanced age is the best predictor of CHIP, with a 5.6% prevalence in the sixth decade and 18.4% in the ninth decade of life.

    “More important, advanced age is the best predictor of CHIP, with a 5.6% or 18.4% prevalence in the sixth or ninth decade of life, respectively.2”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [2] Jaiswal, 2014, Age-related clonal hematopoiesis associated with adverse outcomes, N Engl J Med source

      The Results section, “Increase in the Frequency of Clonal Somatic Mutations with Age” (page not provided), reports that mutations become more frequent with age and gives the cited percentages. But 5.6% applies to ages 60–69 and 18.4% to ages 90 and older—not the sixth and ninth decades of life, respectively. The passage also does not establish that age is the best predictor relative to other factors. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
  • Classified as probably not a substantial claim.

    Premisecitation

    IL-1 has detrimental impacts on WT HSC function.

    “Given the contribution of IL-1 to inflammaging and its detrimental impacts on WT HSC function,23,28 we further focused on the IL-1 pathway.”
    Quote in the paperSubstantial claim2 of 2 sources checked
    • cites [23] Kovtonyuk, 2022, IL-1 mediates microbiome-induced inflammaging of hematopoietic stem cells in mice, Blood source
    • cites [28] Pietras, 2016, Chronic interleukin-1 exposure drives haematopoietic stem cells towards precocious myeloid differentiation at the expense of self-renewal, Nat Cell Biol source
  • Classified as probably not a substantial claim.

    Premisecitation

    Aging associates with chronic low-grade inflammation (inflammaging).

    “Aging associates with chronic low-grade inflammation (ie, inflammaging).18,19”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites [18] Franceschi, 2000, Inflamm-aging: an evolutionary perspective on immunosenescence, Ann N Y Acad Sci source
    • cites [19] Kovtonyuk, 2016, Inflamm-aging of hematopoiesis, hematopoietic stem cells, and the bone marrow microenvironment, Front Immunol source
  • Classified as probably not a substantial claim.

    Premisecitation

    HSPC divisions can be differentiating and self-renewing, particularly in less committed populations.

    “HSPC divisions can be differentiating and self-renewing, particularly in less committed populations.29”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [29] Wilkinson, 2020, Haematopoietic stem cell self-renewal in vivo and ex vivo, Nat Rev Genet source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Progression to hematological malignancies depends on the type and complexity of mutations in CHIP.

    “Furthermore, progression to hematological malignancies depends on the type and complexity of mutations in CHIP.2,5,6”
    Quote in the paperNot a substantial claim3 of 3 sources checked
    • cites [2] Jaiswal, 2014, Age-related clonal hematopoiesis associated with adverse outcomes, N Engl J Med source

      The Results sections on mutation frequency and hematologic-cancer risk report that clonal hematopoiesis usually involved one detected mutation, whereas hematologic cancers often have multiple driver mutations; they also link detectable mutations to higher cancer risk. The paper does not establish that progression depends on mutation type or complexity: its reported risk comparisons concern mutation presence and variant allele fraction, and it could not assess whether later tumors arose from the preceding mutant clones. Page numbers were not available in our copy. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
    • cites [5] Abelson, 2018, Prediction of acute myeloid leukaemia risk in healthy individuals, Nature source

      The Abstract reports that particular mutated genes and the number of mutations affect progression risk, supporting the claim for acute myeloid leukaemia (AML). It does not establish the same relationship for haematological malignancies generally; the study’s stated outcome is progression to AML. No page number is supplied for the passage. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [6] Desai, 2018, Somatic mutations precede acute myeloid leukemia years before diagnosis, Nat Med source

      The Discussion reports that mutation type, high allelic fractions, and clonal complexity are associated with higher risk of progression to AML; the baseline-mutations section also reports different AML risks for different mutated genes. The study addresses AML specifically, not hematological malignancies generally, and reports associations rather than establishing that progression depends on these features. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Loss-of-function heterozygous mutations in DNMT3A account for about 50% to 60% of mutations found in CHIP carriers.

    “Loss-of-function heterozygous mutations in epigenetic regulators DNMT3A (cytosine methyltransferase) and TET2 (methylcytosine dioxygenase) are the most frequently detected mutations in CHIP, accounting for about 50% to 60% and 10% to 30% of mutations found in CHIP carriers, respectively.1, 2, 3,7,8”
    Quote in the paperNot a substantial claim5 of 5 sources checked
    • cites [1] Genovese, 2014, Clonal hematopoiesis and blood-cancer risk inferred from blood DNA sequence, N Engl J Med source

      The Results section reports 190 DNMT3A mutations among 327 candidate driver mutations in clonal hematopoiesis, or about 58%. But that count includes missense as well as disruptive mutations; the paper does not establish that 50%–60% were loss-of-function heterozygous DNMT3A mutations. Page numbers are unavailable in our copy. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [2] Jaiswal, 2014, Age-related clonal hematopoiesis associated with adverse outcomes, N Engl J Med source

      The Results (Identification of Candidate Somatic Mutations; Increase in the Frequency of Clonal Somatic Mutations with Age; page unavailable) report 403 DNMT3A variants among 805 mutations, or about 50%, and identify DNMT3A as the most commonly mutated gene. Our copy does not establish that those DNMT3A mutations were heterozygous loss-of-function mutations, so it does not support that qualification of the percentage. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [3] Xie, 2014, Age-related mutations associated with clonal hematopoietic expansion and malignancies, Nat Med source

      The Results section, “Variants contributing to hematopoietic clonal expansion” (page unavailable), identifies DNMT3A as a recurrently mutated gene, with mutations in 18 cases. But it reports 64 blood-specific mutations in hematological-malignancy-associated genes, making the DNMT3A share about 28%, not 50%–60%. The passages also do not establish that the DNMT3A mutations were heterozygous loss-of-function mutations. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [7] Buscarlet, 2017, DNMT3A and TET2 dominate clonal hematopoiesis and demonstrate benign phenotypes and different genetic predispositions, Blood source

      The ‘Prevalence of mutations’ section reports that DNMT3A accounts for 57.2% (230/402) of documented somatic mutations, supporting the approximate 50%–60% figure. But the ‘Type of mutations’ section includes 142 missense mutations among those 230; the paper does not establish that all mutations counted in the 57.2% are loss-of-function or heterozygous. Page numbers were not available in our copy. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [8] Fabre, 2022, The longitudinal dynamics and natural history of clonal haematopoiesis, Nature source

      The Mutational landscape section (page unavailable) says DNMT3A and TET2 were the most commonly mutated epigenetic regulator genes, and the Discussion (page unavailable) calls DNMT3A reportedly the most common clonal-haematopoiesis driver gene. Neither passage establishes that heterozygous loss-of-function DNMT3A mutations account for 50%–60% of mutations in CHIP carriers. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Tet2-deficient HSPCs exhibit a TLR-TRAF6A and noncanonical NF-κB-dependent competitive advantage during low-grade inflammation.

    “and exhibit a toll-like receptor–TNF receptor associated factor 6A (TLR-TRAF6A) and noncanonical NF-κB–dependent competitive advantage during low-grade inflammation.17”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [17] Muto, 2020, Adaptive response to inflammation contributes to sustained myelopoiesis and confers a competitive advantage in myelodysplastic syndrome HSCs, Nat Immunol source

      The Results section on TET2-deficient HSPCs (page unavailable) reports increased myeloid contribution after competitive transplantation under low-dose LPS, preservation of Tet2-deficient HSPCs, and TRAF6-dependent activation of noncanonical NF-κB. It does not establish that the competitive advantage of Tet2-deficient HSPCs itself depends on noncanonical NF-κB; the long-term competitive-advantage experiment in the separate TLR–TRAF6-primed HSPCs section used TRAF6-overexpressing cells. (LLM, conf=0.85)

      Experimental — accuracy not yet measured
  • May combine two claims.

    Premisecitation

    In CHIP, TET2 mutations show highest clonal expansion rates over time, with an estimated 10% annual growth rate compared with 5% for DNMT3A mutations.

    “In the context of CHIP, TET2 mutations show highest clonal expansion rates over time (with an estimated 10% annual growth rate compared with 5% of DNMT3A mutations7,8,10).”
    Quote in the paperNot a substantial claim2 of 3 sources checked
    • cites [7] Buscarlet, 2017, DNMT3A and TET2 dominate clonal hematopoiesis and demonstrate benign phenotypes and different genetic predispositions, Blood source

      The 'Effect of DNMT3A and TET2 somatic mutations on clonal expansion' section reports an estimated 9.98% yearly increase in mean variant allele frequency (VAF) for TET2, compared with 3.95% for DNMT3A—not 5%. The Discussion explains that these estimates use age at sampling as a surrogate for growth because the cohort was not resampled over time. The paper suggests TET2 may expand faster than DNMT3A, but does not establish that it has the highest rate among all CHIP mutations. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [8] Fabre, 2022, The longitudinal dynamics and natural history of clonal haematopoiesis, Nature source

      The ‘Determinants of clonal growth rate’ section (page not provided) reports average annual growth of about 10% for TET2-mutant clones versus 5% for DNMT3A-mutant clones. It does not support calling TET2 the highest: SRSF2-, PTPN11- and U2AF1-mutant clones grew faster, at 15–20% per year on average. (LLM, conf=0.91)

      Experimental — accuracy not yet measured
    • cites [10] Watson, 2020, The evolutionary dynamics and fitness landscape of clonal hematopoiesis, Science source
  • May combine two claims.

    Premisecitation

    Alternatives via adoptive transfer of unfractionated BM cells into nonirradiated mice are limited by a fixed availability of BM niche space and restricted starting clonal fractions.

    “Although alternatives have been established via adoptive transfer of unfractionated BM cells into nonirradiated mice, these models are limited by a fixed availability of BM niche space and, thus, restricted starting clonal fractions.40,41”
    Quote in the paperSubstantial claim2 of 2 sources checked
    • cites [40] Wang, 2020, Tet2-mediated clonal hematopoiesis in nonconditioned mice accelerates age-associated cardiac dysfunction, JCI Insight source

      The Results (p. 2) describe transfer of unfractionated bone marrow into nonirradiated mice and report low donor-cell engraftment compared with irradiated recipients. The Discussion (p. 8) likewise describes low but stable engraftment. These passages support limited donor contribution, but do not establish that fixed availability of bone marrow niche space causes restricted starting clonal fractions. (LLM, conf=0.82)

      Experimental — accuracy not yet measured
    • cites [41] Fuster, 2020, TET2-loss-of-function-driven clonal hematopoiesis exacerbates experimental insulin resistance in aging and obesity, Cell Rep source

      STAR★METHODS, Method Details (page unavailable), describes transfer of unfractionated bone marrow cells into nonirradiated mice. The Results on age-related insulin resistance (page unavailable) report a small initial donor-cell fraction, but neither passage attributes that fraction to fixed bone-marrow niche space or states that niche space restricts starting clonal fractions. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
  • May combine two claims.

    Premisecitation

    IL-1 can stimulate HSC proliferation, driving their myeloid differentiation at the expense of self-renewal, thus eroding their repopulating capacity.

    “Indeed, IL-1 can stimulate HSC proliferation, driving their myeloid differentiation at the expense of self-renewal, thus eroding their repopulating capacity.28,49,50”
    Quote in the paperSubstantial claim3 of 3 sources checked
    • cites [28] Pietras, 2016, Chronic interleukin-1 exposure drives haematopoietic stem cells towards precocious myeloid differentiation at the expense of self-renewal, Nat Cell Biol source

      The Results sections on IL-1-accelerated differentiation and chronic exposure report faster HSC division, increased myeloid differentiation, and impaired self-renewal and transplantation capacity. But the claim omits the crucial duration qualifier: the Results section on acute stimulation says acute IL-1 exposure promotes myeloid recovery without impairing HSC self-renewal. Page numbers were not provided in our copy. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [49] Ueda, 2009, IL-1R type I-dependent hemopoietic stem cell proliferation is necessary for inflammatory granulopoiesis and reactive neutrophilia, J Immunol source

      The Discussion (page not supplied) reports that HSC proliferate in response to IL-1 in vitro and that IL-1RI-dependent signaling supports HSC proliferation during alum-induced granulopoiesis. It does not establish that this proliferation drives myeloid differentiation at the expense of self-renewal or erodes HSC repopulating capacity; those outcomes are not reported in the passages retrieved. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [50] Chavez, 2021, 1 enforces quiescence and limits hematopoietic stem cell expansion during inflammatory stress, J Exp Med source

      The Introduction and Discussion report that IL-1 can induce HSC cell-cycle activity and precocious myeloid differentiation. But the Discussion emphasizes that IL-1–activated PU.1 restricts proliferation in long-term HSCs, and the passages do not establish the claimed chain from proliferation through lost self-renewal to eroded repopulating capacity. No page numbers are available in our copy. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Higher TET2 mutant clone sizes associate with higher mortality from heart failure (VAF > 2%).

    “and mortality from heart failure (VAF > 2%).38”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [38] Dorsheimer, 2019, Association of mutations contributing to clonal hematopoiesis with prognosis in chronic ischemic heart failure, JAMA Cardiol source

      The Results (Prognostic Significance of CHIP in Patients With Heart Failure; page unavailable) report a dose-response association between clone size and survival, including a VAF group of at least 0.02. The Discussion says increased mortality was mainly driven by heart-failure progression. However, the clone-size analysis groups TET2 with DNMT3A; it does not establish the stated association for TET2 alone. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    TET2 heterozygous loss-of-function mutations are predicted to have high expansion rates (10% increase in mean VAF per year).

    “are predicted to have high expansion rates (10% increase in mean VAF per year1, 2, 3,7)”
    Quote in the paperNot a substantial claim4 of 4 sources checked
    • cites [1] Genovese, 2014, Clonal hematopoiesis and blood-cancer risk inferred from blood DNA sequence, N Engl J Med source

      The Results section on characteristic mutations identifies disruptive TET2 mutations as candidate drivers of clonal hematopoiesis, and the Discussion reports a competitive growth advantage from TET2 loss (page numbers unavailable). Neither passage predicts a high expansion rate or a 10% annual increase in mean VAF for heterozygous TET2 loss-of-function mutations. (LLM, conf=0.85)

      Experimental — accuracy not yet measured
    • cites [2] Jaiswal, 2014, Age-related clonal hematopoiesis associated with adverse outcomes, N Engl J Med source

      The Discussion (page unavailable) reports that TET2 loss-of-function cells have a competitive advantage in mouse models. The Results section on persistence over time (page unavailable) reports increases in variant allele fraction for some mutations, but gives no TET2-specific expansion rate. Neither passage supports the predicted 10% increase in mean VAF per year for heterozygous TET2 loss-of-function mutations. (LLM, conf=0.85)

      Experimental — accuracy not yet measured
    • cites [3] Xie, 2014, Age-related mutations associated with clonal hematopoietic expansion and malignancies, Nat Med source

      The Results (Variants contributing to hematopoietic clonal expansion; page unavailable) associate TET2 mutations with age, and the Discussion identifies TET2 among genes involved in clonal expansion. Neither passage predicts an expansion rate for heterozygous TET2 loss-of-function mutations or reports a 10% increase in mean VAF per year. (LLM, conf=0.87)

      Experimental — accuracy not yet measured
    • cites [7] Buscarlet, 2017, DNMT3A and TET2 dominate clonal hematopoiesis and demonstrate benign phenotypes and different genetic predispositions, Blood source

      The clonal-expansion section reports a 9.98% increase in estimated mean TET2 VAF per year of age, supporting the approximate 10% figure. But it estimates this relationship across TET2 mutations generally, without establishing that the rate applies specifically to heterozygous loss-of-function mutations; the study also lacked serial resampling. (LLM, conf=0.87)

      Experimental — accuracy not yet measured
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Higher TET2 mutant clone sizes associate with higher risk of progression to AML (VAF > 10%).

    “Higher TET2 mutant clone sizes associate with higher risk of progression to AML (VAF > 10%)6”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [6] Desai, 2018, Somatic mutations precede acute myeloid leukemia years before diagnosis, Nat Med source
  • May combine two claims.

    Premisecitation

    Higher basal level of self-renewal, repopulation capacity, and general fitness is reported in Tet2 loss-of-function HSPCs.

    “This likely results from a higher basal level of self-renewal, repopulation capacity, and general fitness reported in Tet2 loss-of-function HSPCs.11, 12, 13”
    Quote in the paperSubstantial claim1 of 3 sources checked
    • cites [11] Ko, 2011, Ten-eleven-translocation 2 (TET2) negatively regulates homeostasis and differentiation of hematopoietic stem cells in mice, Proc Natl Acad Sci U S A source
    • cites [12] Moran-Crusio, 2011, Tet2 loss leads to increased hematopoietic stem cell self-renewal and myeloid transformation, Cancer Cell source
    • cites [13] Quivoron, 2011, TET2 inactivation results in pleiotropic hematopoietic abnormalities in mouse and is a recurrent event during human lymphomagenesis, Cancer Cell source
  • May combine two claims.

    Premisecitation

    In the context of CHIP, Tet2 loss-of-function mutations in myeloid cells result in increased proinflammatory responses, with reported increases in both IL-1 and IL-6 production.

    “in the context of CHIP, Tet2 loss-of-function mutations in myeloid cells result in increased proinflammatory responses, with reported increases in both IL-124,43 and IL-6 production,27”
    Quote in the paperSubstantial claim2 of 3 sources checked
    • cites [24] Fuster, 2017, Clonal hematopoiesis associated with TET2 deficiency accelerates atherosclerosis development in mice, Science source
    • cites [43] Cull, 2017, Tet2 restrains inflammatory gene expression in macrophages, Exp Hematol source
    • cites [27] Zhang, 2015, Tet2 is required to resolve inflammation by recruiting Hdac2 to specifically repress IL-6, Nature source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Progression of Tet2-/- hematopoiesis into myeloid malignancy is abrogated in the absence of Il1r1.

    “Burns et al reported that progression of Tet2–/– hematopoiesis into myeloid malignancy is abrogated in the absence of Il1r1,56”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [56] Burns, 2022, Il-1r1 drives leukemogenesis induced by Tet2 loss, Leukemia source
  • May combine two claims.

    Findingown data

    Intersecting DEGs induced by IL-1α in WT and Tet2+/− samples yields 221 genes unique to IL-1α-treated WT HSCs, 318 genes unique to IL-1α-treated Tet2+/− HSCs, and 515 genes shared by both genotypes.

    “By intersecting DEGs induced by IL-1α in WT and Tet2+/− samples, we obtained DEGs that are unique to IL-1α–treated WT HSCs (221 genes), unique to IL-1α–treated Tet2+/− HSCs (318 genes), and shared by both genotypes on IL-1α treatment (515 genes; Figure 5C; supplemental Table 1).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Terminal assessment of CD45.2+ chimerism in BM HSPCs reveals that IL-1α-treated HSPCs are overall underrepresented, but the fold reduction in WT HSPCs is of much higher magnitude compared with Tet2+/−.

    “More important, terminal assessment of CD45.2+ chimerism in BM HSPCs revealed that although IL-1α–treated HSPCs were overall underrepresented, the fold reduction observed in WT HSPCs was of a much higher magnitude compared with Tet2+/− (Figure 4J).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    IL-1α treatment reduces the LK compartment in both genotypes, whereas expansion of the LSK compartment (MPP1, MPP2, and MPP3) is more evident in Tet2+/− HSPCs.

    “Concerning the BM HSPC frequencies, we observed a general trend for IL-1α treatment to reduce the LK compartment (Lin–c-Kit+Sca-1– cells: CMPs, granulocyte-macrophage progenitors, and megakaryocyte-erythrocyte progenitors) in both genotypes, whereas expansion of the LSK compartment (Lin–c-Kit+Sca-1+: MPP1, MPP2, and MPP3) was more evident in Tet2+/− HSPCs (Figure 4C).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    PCA of transcriptomes from HSCs exposed in vivo to PBS or IL-1α reveals that PBS-treated HSC samples separate from IL-1α-treated ones according to principal component 1, whereas IL-1α-treated WT further separate from IL-1α-treated Tet2+/− HSCs according to principal component 2.

    “Principal component analysis of obtained transcriptomes revealed that in vivo PBS-treated HSC samples separate from IL-1α–treated ones, according to principal component 1, whereas IL-1α–treated WT further separate from IL-1α–treated Tet2+/− HSCs, according to principal component 2 (Figure 5B).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    In young triple-transgenic mice carrying a 10% WT or Tet2+/− ZsG+ clonal fraction, 14-day IL-1α exposure results in a significant increase uniquely in the ZsG+Tet2+/− clonal fraction in PB CD45+ leukocytes, whereas this is not observed in respective controls.

    “Strikingly, IL-1α exposure resulted in a significant increase uniquely in ZsG+Tet2+/− clonal fraction in PB CD45+ leukocytes (Figure 3B), whereas this was not observed in respective controls.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    IL-1α exposure decreases the frequency of cells in G0 in both genotypes, but this effect is significantly stronger in Tet2+/− LT-HSCs, MPP1s, and MPP3.

    “In detail, IL-1α exposure decreased the frequency of cells in G0 in both genotypes, although this effect was significantly stronger in Tet2+/− LT-HSCs, MPP1s, and MPP3 (Figure 4D).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Although IL-1α exposure reduces the replating capacity of HSPCs in both genotypes, Tet2+/− HSPCs are more resistant and able to form colonies up to the fourth replating cycle.

    “Interestingly, although IL-1α exposure reduced the replating capacity of HSPCs in both genotypes, the Tet2+/− HSPCs were more resistant to this effect and were able to form colonies up to the fourth replating cycle (Figure 4F)”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    In aged WT and Tet2+/− total BM cells, Il1r1 and Il1r2 gene expression show no differences, and Il1rn expression is decreased in Tet2+/− cells.

    “IL-1 pathway member quantification in aged WT and Tet2+/− total BM cells showed no differences in Il1r1 and Il1r2 gene expression and a decrease in Ilr1rn (IL1R antagonist) expression in Tet2+/− cells (Figure 2G).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Tet2+/− clonal expansion in PB leukocytes and HSPCs is further increased in animals aged for 28 months and in animals induced at a more advanced age.

    “More important, Tet2+/− clonal expansion in PB leukocytes and HSPCs was further increased in animals aged for 28 months (supplemental Figure 2C-E) and in animals induced at a more advanced age (supplemental Figure 2F-H)”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    IL-1α exposure has no effect on HSPC apoptotic levels, except CLPs show decreased viability in both genotypes.

    “Viability analysis showed no effect of IL-1α exposure on HSPC apoptotic levels, except for CLPs that showed decreased viability in both genotypes (supplemental Figure 4B).”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    IL-1α pretreatment significantly reduces PB CD45.2+ chimerism in all lineages in both genotypes, but Tet2+/− cells are more resistant to this effect.

    “Moreover, although IL-1α pretreatment reduced significantly PB CD45.2+ chimerism in all lineages in both genotypes, Tet2+/− cells were more resistant to this effect (Figure 4H-I).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    IL-1α induces myeloid differentiation gene expression in both WT and Tet2+/− HSCs, with enrichment in GO biological processes implicated in neutrophil biology, inflammatory response, and myeloid differentiation.

    “Accordingly, we observed that IL-1α induces myeloid differentiation gene expression in both WT and Tet2+/− HSCs (with enrichment in GO BPs implicated in neutrophil biology, inflammatory response, and myeloid differentiation; Figure 5D)”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Tet2+/− HSCs exposed to IL-1α show enrichment in biological processes implicated in DNA replication initiation (associated with overexpression of Mcm2-4 and 10, Cdc6, and Orc1 genes), cell cycle progression (associated with increased e2f1 expression and downstream transcriptional program), and DNA repair pathways (associated with overexpression of Rad51, Rad51b, and Fanca/i genes).

    “Tet2+/− HSCs exposed to IL-1α showed an enrichment in BPs implicated in DNA replication initiation (associated with overexpression of Mcm2-4 and 10, Cdc6, and Orc1 genes), cell cycle progression (associated with increased e2f1 expression and downstream transcriptional program), and DNA repair pathways (associated with overexpression of Rad51, Rad51b, and Fanca/i genes) (Figure 5G-I).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    IL-1α exposure has a major impact on HSPC proliferative responses, particularly in the LSK compartment, with minor impact in LK cells.

    “In contrast, cell cycle analysis revealed a major impact of IL-1α exposure on HSPC proliferative responses, particularly in the LSK compartment (minor impact in LK cells; supplemental Figure 4C).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    In triple-transgenic mice induced with a single TAM injection to generate an about 10% clonal hematopoietic fraction and aged for 12 months, Tet2+/− clonal fractions in PB CD45+ leukocytes increase over time and expand significantly more than WT.

    “Longitudinal quantification of ZsG+ WT and ZsG+Tet2+/− clonal fractions in PB CD45+ leukocytes showed that, although both clonal fractions increase over time, there was a significantly higher expansion of the Tet2+/− clone compared with the WT (Figure 2B-C).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The HSC-SCL-Cre-ERT; Tet2+/flox; R26+/tm6(CAG-ZsGreen1)Hze model's ZsG+ cells faithfully represent Tet2+/− HSPC-derived hematopoiesis throughout aging.
    • Rests on an assumption: The 10% TAM-induced clonal hematopoietic fraction mimics the clonal fractions and behavior of human CHIP.
  • May combine two claims.

    Findingown data

    In standard BM transplantation chimera models, IL-1α exposure leads to a specific and significant expansion of CD45.2+ Tet2+/− clone size in all leukocyte lineages and in multiple hematopoietic progenitors (CLPs, LSKs, MPP1,3, and LT-HSCs).

    “As observed in the inducible BM chimera model, IL-1α exposure led to a specific and significant expansion of CD45.2+ Tet2+/− clone size in all leukocyte lineages (Figure 3F-G) and in multiple hematopoietic progenitors (CLPs, LSKs, MPP1,3, and LT-HSCs; Figure 3H).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Anakinra treatment prevented HSPC differentiation but did not revert an established clonal dominance in the HSPC pool.

    “the anakinra regimen used was not sufficient to fully prevent Tet2+/− HSPC clonal expansion (Figure 6H)”
    • Also stated in: § Genetic and pharmacologic blockage of IL-1–IL-1R1 signaling reduces Tet2+/− clonal expansion during aging · hedged
      “suggesting that the anakinra treatment doses and timing used were not sufficient to revert an already established clonal dominance.”
    • Also stated in: § Discussion · plain
      “IL-1R antagonist treatment prevented HSPC differentiation but did not revert an established clonal dominance in the HSPC pool.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Two separate phases of Tet2+/− expansion were observed: an initial expansion within the first 2 months after transplantation, not observed in the inducible model; and a later expansion between months 7 and 9, shared with the inducible model.

    “we observed 2 separate phases of Tet2+/− expansion: an initial expansion within the first 2 months after transplantation (possibly resulting from irradiation-derived inflammation), which is not observed in the inducible model; and a later expansion between months 7 and 9, which is shared with the inducible model (Figure 6C).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    Murine Tet2+/− clonal expansion rates increase with age and associate with increased BM levels of myeloid-derived inflammatory cytokine IL-1.

    “(a) murine Tet2+/− clonal expansion rates increase with age and associate with increased BM levels of myeloid-derived inflammatory cytokine IL-1”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    The triple-transgenic mouse model revealed a Tet2+/− clonal expansion stage exclusive to advanced aged and associated with increased BM IL-1 levels.

    “this approach revealed a Tet2+/− clonal expansion stage exclusive to advanced aged and associated with increased BM IL-1 levels”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Data are a pool of at least 2 independent experiments for all graphs, except J through L.

    “Data are a pool of at least 2 independent experiments for all graphs, except J through L.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationown data

    During aging, starting at about 7 to 8 months, there is a multilineage Tet2+/− hematopoietic clonal expansion, which associates with increased cell-extrinsic proinflammatory IL-1 levels, produced mainly by the myeloid BM compartment.

    “Collectively, these data indicate that during aging, starting at about 7 to 8 months, there is a multilineage Tet2+/− hematopoietic clonal expansion, which associates with increased cell-extrinsic proinflammatory IL-1 levels, produced mainly by the myeloid BM compartment.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: BM IL-1 protein levels measured in lysates reflect bioactive IL-1 signaling in the BM niche.
  • May combine two claims.

    Study design and conductown data

    ZsG expression leakiness occurs in the absence of TAM injection, is independent of sex, and increases with age up to 2.5% frequency at 10 months of age.

    “Further characterization of the model revealed ZsG expression leakiness, with low expression levels in the absence of TAM injection, which was independent of sex but increased with age (up to 2.5% frequency at 10 months of age; Figure 1E).”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Study design and conductown data

    After 5 consecutive TAM injections at 100 mg/kg, triple-transgenic mice show high ZsG expression in all BM hematopoietic mature and progenitor/stem populations (range, 80%-100%) and low ZsG expression in nonhematopoietic cells (range, 3%-5%).

    “To validate the model, we exposed triple-transgenic mice to 5 consecutive injections of TAM at 100 mg/kg and observed high ZsG expression in all BM hematopoietic mature and progenitor/stem populations (range, 80%-100%) and low ZsG expression in nonhematopoietic cells (range, 3%-5%), thus confirming the relatively high hematopoietic specificity of CreERT activity”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationown data

    The IL-1α-IL-1R1 axis is a direct driver of increased Tet2+/− multilineage differentiation, leading to Tet2+/− hematopoietic clonal fitness gain and dominance over WT hematopoiesis.

    “Overall, these data establish the IL-1α–IL-1R1 axis as a direct driver of increased Tet2+/− multilineage differentiation, leading to Tet2+/− hematopoietic clonal fitness gain and dominance over WT hematopoiesis.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Study design and conductown data

    The triple-transgenic model is an irradiation/transplantation-independent, TAM-dose-dependent inducible, and traceable genetic chimerism model to study Tet2+/− clonal hematopoiesis.

    “Altogether, these data validate the generation of an irradiation/transplantation-independent, TAM-dose–dependent inducible, and traceable genetic chimerism model to study Tet2+/− clonal hematopoiesis.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The HSC-SCL-Cre-ERT; Tet2+/flox; R26+/tm6(CAG-ZsGreen1)Hze model's ZsG+ cells faithfully represent Tet2+/− HSPC-derived hematopoiesis throughout aging.
  • May combine two claims.

    Interpretationown data

    Tet2+/− HSPCs maintain higher proliferative responses on long-term IL-1α exposure that result in a higher repopulation capacity compared with WT, thus contributing to an overall enhanced cellular competitive fitness in this setting.

    “Collectively, these data demonstrate that Tet2+/− HSPCs maintain higher proliferative responses on long-term IL-1α exposure that result in a higher repopulation capacity compared with WT, thus contributing to an overall enhanced cellular competitive fitness in this setting.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    All mice were housed and handled according to the guidelines of the Swiss Federal Veterinary Office under specific pathogen-free conditions, and all experiments were approved by the Veterinaramt Kanton Zurich.

    “All mice were housed and handled according to the guidelines of the Swiss Federal Veterinary Office under specific pathogen-free conditions. All experiments were approved by the Veterinaramt Kanton Zurich (Zurich, Switzerland).”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationown data

    Tet2+/− LT-HSCs, MPP1s, and MPP3 are more sensitive to IL-1α-mediated proliferation and possibly less likely to return to a quiescent state after long-term IL-1α stimulation than WT.

    “This suggests that these cells are more sensitive to IL-1α–mediated proliferation and possibly less likely to return to a quiescent state after long-term IL-1α stimulation than WT.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationown data

    IL-1-dependent increased proliferative activity in Tet2+/− HSPCs is both differentiating and self-renewing.

    “suggesting that IL-1–dependent increased proliferative activity in Tet2+/− HSPCs is both differentiating and self-renewing.”
    Quote in the paperSubstantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisenone given

    TET2 heterozygous loss-of-function mutations are frequent in CHIP (about 10%-30% prevalence).

    “TET2 heterozygous loss-of-function mutations are frequent in CHIP (about 10%-30% prevalence)”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Interpretationreasoning

    IL-1 is sensed directly by the HSPC pool via IL-1R1 and favors the dominance of Tet2+/− HSPCs via enhanced proliferation and differentiation into mature blood cells, increasing Tet2+/− cell frequency over WT cells.

    “IL-1 is sensed directly by the HSPC pool via IL-1R1 and favors the dominance of Tet2+/− HSPCs via enhanced proliferation and differentiation into mature blood cells, increasing Tet2+/− cell frequency over WT cells.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationown data

    The IL-1-mediated proliferative response resulted in increased differentiation of Tet2+/− over WT HSPCs, leading to expansion of the Tet2+/− clone in all blood lineages.

    “According to our data, this IL-1–mediated proliferative response resulted in increased differentiation of Tet2+/− over WT HSPCs, leading to expansion of the Tet2+/− clone in all blood lineages.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationreasoning

    The oncogenic Tet2 mutation increases cellular fitness exclusively in the context of an aged and inflammatory environment, whereas the same mutation in a younger and noninflammatory milieu is less selectively expanded.

    “whereby the oncogenic Tet2 mutation, by endowing mutant HSPCs more resistant to the deleterious effects of high IL-1 levels, increases cellular fitness exclusively in the context of an aged and inflammatory environment, whereas the same mutation in a younger and noninflammatory milieu is less selectively expanded.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationown data

    In both artificial IL-1α exposure in young mice and physiological inflammaging, Tet2+/− HSPCs show higher clonal fitness.

    “These data suggest that in the context of both artificial IL-1α exposure in young mice and physiological inflammaging, Tet2+/− HSPCs show higher clonal fitness.”
    Quote in the paperSubstantial claim
56 of 56
  • The paper relies on this without support.

    The HSC-SCL-Cre-ERT; Tet2+/flox; R26+/tm6(CAG-ZsGreen1)Hze model's ZsG+ cells faithfully represent Tet2+/− HSPC-derived hematopoiesis throughout aging.

    “Altogether, these data validate the generation of an irradiation/transplantation-independent, TAM-dose–dependent inducible, and traceable genetic chimerism model to study Tet2+/− clonal hematopoiesis.”
  • The paper relies on this without support.

    BM IL-1 protein levels measured in lysates reflect bioactive IL-1 signaling in the BM niche.

    “In agreement with gene expression data, we detected increased IL-1α protein levels in Tet2+/− BM (Figure 2H)”
  • The paper relies on this without support.

    Findings in the mouse Tet2+/− clonal hematopoiesis model are relevant to human CHIP.

    “Understanding the drivers of clonal expansion in CHIP-carrying individuals during aging is key to devise potential therapeutic interventions for this population.”
  • The paper relies on this without support.

    The 10% TAM-induced clonal hematopoietic fraction mimics the clonal fractions and behavior of human CHIP.

    “triple-transgenic mice carrying wild-type (WT group) or a heterozygous floxed Tet2 gene (Tet2+/− group) were induced with a single TAM injection to generate an about 10% clonal hematopoietic fraction and aged for 12 months (Figure 2A).”
4 of 4

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Tet2-deficient HSPC exhibit similar characteristics to PU.1-deficient HSPC, namely the capacity to undergo accelerated expansion in the context of chronic inflammation, coupled with altered cell cycle activity.

    “Indeed, Tet2-deficient HSPC exhibit similar characteristics to PU.1-deficient HSPC, namely the capacity to undergo accelerated expansion in the context of chronic inflammation, coupled with altered cell cycle activity (Consortium et al., 2007; Caiado et al., 2022).”

    From PU.1 is required to restrain myelopoiesis during chronic inflammatory stress (2023) · cites this paper as Caiado et al., 2022

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Anakinra timing refers to tamoxifen in noninjected mice

    Minor

    The methods place the start of anakinra treatment 11 months after tamoxifen injection, but the described anakinra experiment uses mice that were not injected with tamoxifen.

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Authors
Caiado, F., Kovtonyuk, L. V., Gonullu, N. G., Fullin, J., Boettcher, S., & Manz, M. G.
Affiliations
University of Zurich (CH)
Venue
Blood
Published
2023-02-23
Volume
141
Issue
8
Pages
886-903
ISSN
  • 0006-4971 (ISSN-L)
  • 1528-0020
OpenAlex
W4309088916
Cited by
161
References
60
Citations by year
2026: 47 · 2025: 47 · 2024: 44 · 2023: 23
FWCI
17.75
Type
journal article
Language
en
Open access
Locations
  • Blood (publishedVersion, cc-by-nc-nd)
  • PubMed (publishedVersion)
  • Zurich Open Repository and Archive (University of Zurich) (acceptedVersion, cc-by-nc-nd)
  • PubMed Central (submittedVersion, cc-by-nc-nd)
  • Zurich Open Repository and Archive (University of Zurich) (submittedVersion, cc-by-nc-nd)
  • Zurich Open Repository and Archive (University of Zurich)
Funders
  • National Science Foundation
  • Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (310030_184747/1, 310030)
Topics
  • Health Sciences › Medicine › Hematology › Acute Myeloid Leukemia Research
  • Health Sciences › Medicine › Hematology › Hematopoietic Stem Cell Transplantation
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Blood disorders and treatments
Keywords
clonal hematopoiesis of indeterminate potential, TET2, aging, IL-1 signaling, IL-1 receptor 1, hematopoietic stem and progenitor cells, clonal expansion, inflammation, DNA replication and repair, self-renewal, multilineage differentiation, hematological malignancy risk, bone marrow transplantation, genetic mosaicism
MeSH terms
Clonal Hematopoiesis, Aging, Animals, Cardiovascular Diseases, DNA-Binding Proteins, Hematopoiesis, Interleukin-1, Mutation, Dioxygenases, Mice

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-28.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-28.

Cited sources are checked by gpt-6-sol.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

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