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Cited by 75Neuroinflammation and Neurodegeneration MechanismsAlzheimer's disease research and treatmentsInflammasome and immune disorders

IL-1β-driven amyloid plaque clearance is associated with an expansion of transcriptionally reprogrammed microglia

Open access
Rivera-Escalera, Fátima, Pinney, Jonathan J., Owlett, Laura, Ahmed, Hoda, Thakar, Juilee, Olschowka, John A., Elliott, Michael R., O’Banion, M. Kerry·2019·Journal of Neuroinflammation
DOI 10.1186/s12974-019-1645-7PMC PMC6902486
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Abstract

Background: Neuroinflammation is thought to contribute to the pathogenesis of Alzheimer’s disease (AD), yet numerous studies have demonstrated a beneficial role for neuroinflammation in amyloid plaque clearance. We have previously shown that sustained expression of IL-1β in the hippocampus of APP/PS1 mice decreases amyloid plaque burden independent of recruited CCR2+myeloid cells, suggesting resident microglia as the main phagocytic effectors of IL-1β-induced plaque clearance. To date, however, the mechanisms of IL-1β-induced plaque clearance remain poorly understood. Methods: To determine whether microglia are involved in IL-1β-induced plaque clearance, APP/PS1 mice induced to express mature human IL-1β in the hippocampus via adenoviral transduction were treated with the Aβ fluorescent probe methoxy-X04 (MX04) and microglial internalization of fibrillar Aβ (fAβ) was analyzed by flow cytometry and immunohistochemistry. To assess microglial proliferation, APP/PS1 mice transduced with IL-1β or control were injected intraperitoneally with BrdU and hippocampal tissue was analyzed by flow cytometry. RNAseq analysis was conducted on microglia FACS sorted from the hippocampus of control or IL-1β-treated APP/PS1 mice. These microglia were also sorted based on MX04 labeling (MX04+and MX04−microglia). Results: Resident microglia (CD45 lo CD11b+) constituted > 70% of the MX04+cells in both Phe- and IL-1β-treated conditions, and < 15% of MX04+cells were recruited myeloid cells (CD45 hi CD11b+). However, IL-1β treatment did not augment the percentage of MX04+microglia nor the quantity of fAβ internalized by individual microglia. Instead, IL-1β increased the total number of MX04+microglia in the hippocampus due to IL-1β-induced proliferation. In addition, transcriptomic analyses revealed that IL-1β treatment was associated with large-scale changes in the expression of genes related to immune responses, proliferation, and cytokine signaling. Conclusions: These studies show that IL-1β overexpression early in amyloid pathogenesis induces a change in the microglial gene expression profile and an expansion of microglial cells that facilitates Aβ plaque clearance.

AI snapshot

Written from the paper’s full text.

TL;DR

IL-1β overexpression in the hippocampus of APP/PS1 mice reduces amyloid plaque burden primarily by expanding the resident microglial population through proliferation, not by increasing the phagocytic capacity of individual microglia. RNAseq shows that IL-1β drives large-scale microglial transcriptional reprogramming related to immune responses, proliferation, and cytokine signaling.

Key findings

  • Resident microglia (CD45loCD11b+) constituted >70% of MX04+ cells in both Phe- and IL-1β-treated mice, while <15% of MX04+ cells were recruited myeloid cells (CD45hiCD11b+).
  • IL-1β did not increase the percentage of MX04+ microglia (approximately 8% in both conditions) or the mean fluorescence intensity of MX04 per microglia, nor did it alter the percentage of Aβ+ microglia or their localization to plaques by IHC.
  • IL-1β significantly increased the total number of MX04+ microglia in the hippocampus by nearly two-fold, increased total microglia, and increased BrdU+ proliferating microglia; IHC showed an IL-1β-associated doubling of Iba1+6E10+ cells and increased plaque-associated microglia.
  • RNAseq identified 315 differentially expressed genes in IL-1β-treated versus Phe-treated APP/PS1 microglia, with 110 shared between MX04+ and MX04− microglia, 44 in MX04− microglia, and 143 in MX04+ microglia; GO terms most impacted were immune responses, proliferation, and cytokine signaling. Only 6 DEGs were specific to Aβ+ microglia, including reduced Rab7b and Ch25h in MX04+ versus MX04− microglia in control-treated mice.

Methods

  • 7.5-month-old APP/PS1 mice received bilateral intrahippocampal rAAV2-IL-1β or control rAAV2-Phe and were sacrificed 3–4 weeks later; methoxy-X04 (MX04) was injected i.p. 3 days before sacrifice, and BrdU was injected to label proliferating cells.
  • Hippocampal single-cell preparations were analyzed by flow cytometry for CD45/CD11b, MX04, and BrdU; immunohistochemistry was used for 6E10, Iba1, GFAP, and BrdU; qRT-PCR measured Csf1, Il34, Tgfb1, and Il1b mRNA.
  • RNAseq was performed on FACS-sorted microglia (MX04+ and MX04−) from control- or IL-1β-treated APP/PS1 mice, with two biological replicates of pooled cells from 6–8 hippocampi per group; DESeq2 was used with q < 0.05 and log2 |fold change| ≥ 1.

Limitations

  • Stated: BrdU staining for flow cytometry was not compatible with MX04 signal, so the authors could not conclude whether BrdU+ microglia internalized Aβ; flow cytometry did not distinguish CD45hi myeloid/lymphoid subsets or astrocytes; the study focused on fibrillar Aβ and could not rule out contributions from soluble Aβ uptake or degradation/flux; live two-photon imaging was beyond scope; effects in other brain regions were not addressed.
  • Evident from the text: RNAseq used only two biological replicates per experimental group, limiting statistical power; the link between microglial proliferation and plaque clearance is correlational, as the authors did not directly test whether blocking proliferation prevents IL-1β-mediated clearance.

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

Integrity signals

Registry

Crossref · 10.1186/s12974-019-1645-7

Cites

96 of 96 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

47 of 62 cited sources checked · 24 supported · 2 flagged · accuracy not yet measured

  • Premisecitation

    Recruited myeloid cells are not as competent at restricting fAβ as resident microglia.

    “consistent with several studies showing that recruited myeloid cells are not as competent at restricting fAβ as resident microglia [48–50].”
    Quote in the paperNot a substantial claim3 of 3 sources checked
    • cites [48] Mildner A, Schlevogt B, Kierdorf K, Bottcher C, Erny D, Kummer MP, Quinn M, Bruck W, Bechmann I, Heneka MT, et al. Distinct and non-redundant roles of microglia and myeloid subsets in mouse models of Alzheimer’s disease. J Neurosci. 2011;31:11159–71. source

      The section “Perivascular macrophages in AD transgenic mice clear Aβ in a CCR2-dependent manner” concludes that peripheral macrophages, rather than parenchymal microglia, modulate amyloid deposition by clearing Aβ. The section on BM-derived phagocytes finds that their recruitment did not change parenchymal Aβ load, but it does not establish that resident microglia are more competent at restricting it. Page numbers were not provided for these passages. (LLM, conf=0.87)

      Checked by a reasoning model — may be wrong.

      Experimental — accuracy not yet measured
    • cites [49] Prokop S, Miller KR, Drost N, Handrick S, Mathur V, Luo J, Wegner A, Wyss-Coray T, Heppner FL. Impact of peripheral myeloid cells on amyloid-β pathology in Alzheimer’s disease–like mice. J Exp Med. 2015;212:1811–8. source

      In Results and Discussion, under “No recruitment of peripherally derived myeloid cells to Aβ plaques” (page unavailable), resident microglia cluster around plaques whereas recruited myeloid cells do not. But “Unaltered Aβ pathology in the presence of peripherally derived myeloid cells” reports no difference in plaque burden, including Congo red–positive plaques, after replacement. The paper therefore supports a weaker plaque-targeting response, not the claim that recruited cells are less competent at restricting fibrillar Aβ. (LLM, conf=0.85)

      Experimental — accuracy not yet measured
    • cites [50] Varvel NH, Grathwohl SA, Degenhardt K, Resch C, Bosch A, Jucker M, Neher JJ. Replacement of brain-resident myeloid cells does not alter cerebral amyloid-β deposition in mouse models of Alzheimer’s disease. J Exp Med. 2015;212:1803–9. source

      In Results and Discussion, the paper reports no change in congophilic plaques after peripheral myeloid cells replaced resident cells. It concludes that, in its mouse models, infiltrating monocytes did not perform a long-term function sufficiently distinct from microglia to modify cerebral β-amyloidosis—not that they were less competent at restricting fibrillar Aβ. Page numbers are not provided in our copy. (LLM, conf=0.88)

      Checked by a reasoning model — may be wrong.

      Experimental — accuracy not yet measured
  • Findingcitation

    There was minimal recruitment of CD45hi peripheral immune cells (CD11b+ and CD11b−) in APP/PS1-Phe mice.

    “In agreement with our previous observations [28, 30] there was minimal recruitment of CD45hi peripheral immune cells (CD11b+ and CD11b−) in APP/PS1-Phe mice”
    Quote in the paperSubstantial claim2 of 2 sources checked
    • cites [28] Rivera-Escalera F, Matousek SB, Ghosh S, Olschowka JA, O'Banion MK. Interleukin-1beta mediated amyloid plaque clearance is independent of CCR2 signaling in the APP/PS1 mouse model of Alzheimer’s disease. Neurobiol Dis. 2014;69:124–33. source

      The Results (page unavailable) report no GFP+ peripheral-derived cells in control-vector hippocampi of APP/PS1/CCR2−/− mice, and the Discussion reports no evidence of peripheral plaque-associated microglia in APP/PS1 mice without IL-1 induction. These findings support minimal recruitment in control conditions, but the paper does not establish that both CD45hi/CD11b+ and CD45hi/CD11b− populations were minimally recruited specifically in APP/PS1-Phe mice. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
    • cites [30] Shaftel SS, Carlson TJ, Olschowka JA, Kyrkanides S, Matousek SB, O'Banion MK. Chronic interleukin-1beta expression in mouse brain leads to leukocyte infiltration and neutrophil-independent blood brain barrier permeability without overt neurodegeneration. J Neurosci. 2007;27:9301–9. source

      The ‘Diverse leukocyte populations are recruited by IL-1β expression’ section reports a fivefold increase in CD45hi/CD11b+ cells in IL-1β XAT mice, not minimal recruitment in APP/PS1-Phe mice. Our copy does not address APP/PS1-Phe mice or the claimed CD11b+ and CD11b− recruitment pattern; the finding in a different mouse model does not establish a contradiction. (LLM, conf=0.76)

      Experimental — accuracy not yet measured
  • Premisecitation

    IL-1β does not influence Aβ production.

    “This is consistent with our previously published data showing that IL-1β does not influence Aβ production [4, 6, 7, 28].”
    Quote in the paperSubstantial claim4 of 4 sources checked
    • cites [4] Shaftel SS, Kyrkanides S, Olschowka JA, Miller JN, Johnson RE, O’Banion MK. Sustained hippocampal IL-1 beta overexpression mediates chronic neuroinflammation and ameliorates Alzheimer plaque pathology. J Clin Invest. 2007;117:1595–604. source

      In “IL-1β overexpression reduces amyloid pathology” (page not supplied), the paper reports no evidence that IL-1β altered APP or BACE-1 expression or activity, and concludes that reduced plaques in its mouse model were likely not due to changes in Aβ synthesis. That supports the claim for this model, but not the unqualified assertion that IL-1β does not influence Aβ production generally. (LLM, conf=0.87)

      Experimental — accuracy not yet measured
    • cites [6] Matousek SB, Ghosh S, Shaftel SS, Kyrkanides S, Olschowka JA, O'Banion MK. Chronic IL-1beta-mediated neuroinflammation mitigates amyloid pathology in a mouse model of Alzheimer’s disease without inducing overt neurodegeneration. J Neuroimmune Pharmacol. 2012;7:156–64. source

      The Results section (page not provided) reports that IL-1β induction did not significantly alter soluble Aβ, full-length APP, or BACE-1 in the studied mouse model. The Discussion likewise reports no significant change in APP production or processing. These findings support the claim in this model, but not the unqualified statement that IL-1β does not influence Aβ production generally. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [7] Ghosh S, Wu MD, Shaftel SS, Kyrkanides S, LaFerla FM, Olschowka JA, O’Banion MK. Sustained interleukin-1beta overexpression exacerbates tau pathology despite reduced amyloid burden in an Alzheimer's mouse model. J Neurosci. 2013;33:5053–64. source

      The Results (page unavailable) report unchanged APP, BACE, and β-CTF levels in the studied mice; the Discussion says these findings indicate unaltered secretase activity. This supports no detected change in markers of Aβ production in this mouse model, but not the unqualified claim that IL-1β does not influence Aβ production generally. (LLM, conf=0.85)

      Experimental — accuracy not yet measured
    • cites [28] Rivera-Escalera F, Matousek SB, Ghosh S, Olschowka JA, O'Banion MK. Interleukin-1beta mediated amyloid plaque clearance is independent of CCR2 signaling in the APP/PS1 mouse model of Alzheimer’s disease. Neurobiol Dis. 2014;69:124–33. source

      The Results (pages not provided) report that IL-1β overexpression did not alter APP levels or processing in the hippocampus of APP/PS1 mice, including BACE activity and β-CTF products. This supports unchanged Aβ production in that experimental setting, but the paper does not directly measure production rates or establish that IL-1β never influences Aβ production more generally. (LLM, conf=0.82)

      Experimental — accuracy not yet measured
  • Premisecitation

    Disrupting CCR2 signaling and recruitment of BMD-mononuclear phagocytes did not alter the ability of IL-1β to reduce amyloid plaque burden.

    “However, disrupting CCR2 signaling and recruitment of BMD-mononuclear phagocytes did not alter the ability of IL-1β to reduce amyloid plaque burden [28].”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites [28] Rivera-Escalera F, Matousek SB, Ghosh S, Olschowka JA, O'Banion MK. Interleukin-1beta mediated amyloid plaque clearance is independent of CCR2 signaling in the APP/PS1 mouse model of Alzheimer’s disease. Neurobiol Dis. 2014;69:124–33. source
  • Findingcitation

    Sustained hippocampal IL-1β expression decreases amyloid plaque accumulation in APP/PS1 mice.

    “As previously described [28], APP/PS1 mice transduced with rAAV2-IL-1β showed significant reductions in hippocampal amyloid plaques compared to mice treated with rAAV2-Phe, as determined by immunohistochemical (IHC) analysis using both 6E10 staining and MX04 (Fig. 1b)”
    • Also stated in: § Introduction · plain
      “we found that sustained hippocampal IL-1β expression decreases amyloid plaque accumulation in APPswe/PS1dE9 (APP/PS1) mice [4, 6]”
    Quote in the paperSubstantial claim3 of 3 sources checked
    • cites [28] Rivera-Escalera F, Matousek SB, Ghosh S, Olschowka JA, O'Banion MK. Interleukin-1beta mediated amyloid plaque clearance is independent of CCR2 signaling in the APP/PS1 mouse model of Alzheimer’s disease. Neurobiol Dis. 2014;69:124–33. source
    • cites [4] Shaftel SS, Kyrkanides S, Olschowka JA, Miller JN, Johnson RE, O’Banion MK. Sustained hippocampal IL-1 beta overexpression mediates chronic neuroinflammation and ameliorates Alzheimer plaque pathology. J Clin Invest. 2007;117:1595–604. source
    • cites [6] Matousek SB, Ghosh S, Shaftel SS, Kyrkanides S, Olschowka JA, O'Banion MK. Chronic IL-1beta-mediated neuroinflammation mitigates amyloid pathology in a mouse model of Alzheimer’s disease without inducing overt neurodegeneration. J Neuroimmune Pharmacol. 2012;7:156–64. source

      The Results section reports significantly reduced hippocampal 6E10-positive plaques after sustained IL-1β upregulation in APP/PS1 mice, supporting the general claim. But this paper induced IL-1β using an IL-1βXAT model with FIV-Cre and an FIV-LacZ control; it does not establish the citing sentence’s rAAV2-IL-1β versus rAAV2-Phe comparison or its MX04 staining result. (LLM, conf=0.89)

      Experimental — accuracy not yet measured
  • Classified as probably not a substantial claim. 28
  • May combine two claims. 13
  • The quote only partly states this claim. 1

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Microglia are brain-resident innate immune effector cells and are widely thought to be the key mediators of amyloid beta clearance.

    “Microglia are brain-resident innate immune effector cells and are widely thought to be the key mediators of amyloid beta clearance [14–16].”
    Quote in the paperSubstantial claim3 of 3 sources checked
    • cites [14] Bolmont T, Haiss F, Eicke D, Radde R, Mathis CA, Klunk WE, Kohsaka S, Jucker M, Calhoun ME. Dynamics of the microglial/amyloid interaction indicate a role in plaque maintenance. J Neurosci. 2008;28:4283–92. source

      The Introduction describes microglia reacting to brain injury and phagocytosing amyloid beta, and the Discussion reports that they can take up amyloid in vivo. But the paper calls their role in clearance controversial and says their response is inefficient at clearing existing deposits without additional manipulation. It does not establish resident microglia as the key mediators of amyloid beta clearance. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
    • cites [15] Sarlus H, Heneka MT. Microglia in Alzheimer’s disease. J Clin Invest. 2017;127:3240–9. source
    • cites [16] Weitz TM, Town T. Microglia in Alzheimer’s disease: it’s all about context. Int J Alzheimers Dis. 2012;2012:314185. source

      The Introduction identifies microglia as brain-resident macrophages involved in innate immune responses. But section 4.1 says they are generally regarded as inefficient Aβ phagocytes, and section 6 reports evidence that brain-resident microglia may not significantly affect plaque clearance. The paper therefore does not support calling them the key mediators of Aβ clearance. (LLM, conf=0.88)

      Experimental — accuracy not yet measured

  • Classified as probably not a substantial claim.

    Premisecitation

    This impairment has been shown to correlate with increased production of proinflammatory cytokines and overwhelming accumulation of Aβ plaques in the AD brain.

    “This impairment has been shown to correlate with increased production of proinflammatory cytokines and overwhelming accumulation of Aβ plaques in the AD brain [20–22].”
    Quote in the paperSubstantial claim2 of 3 sources checked
    • cites [20] Babcock AA, Ilkjaer L, Clausen BH, Villadsen B, Dissing-Olesen L, Bendixen AT, Lyck L, Lambertsen KL, Finsen B. Cytokine-producing microglia have an altered beta-amyloid load in aged APP/PS1 Tg mice. Brain Behav Immun. 2015;48:86–101. source
    • cites [21] Baron R, Babcock AA, Nemirovsky A, Finsen B, Monsonego A. Accelerated microglial pathology is associated with Abeta plaques in mouse models of Alzheimer’s disease. Aging Cell. 2014;13:584–95. source

      The Results section on APP transgenic mice and the Discussion associate impaired microglial coverage with Aβ plaques in mouse models. The reported cytokine increase was measured during aging in wild-type mice; the Discussion cautions that plaque-associated microglial changes do not readily translate into robust cytokine upregulation. The paper therefore does not establish the full correlation claimed for the human AD brain. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [22] Hickman SE, Allison EK, El Khoury J. Microglial dysfunction and defective beta-amyloid clearance pathways in aging Alzheimer's disease mice. J Neurosci. 2008;28:8354–60. source

      The Results report increased proinflammatory cytokine expression in older PS1-APP mice and florid Aβ plaques in their brains; the Discussion links impaired microglial Aβ clearance to increased Aβ accumulation. The evidence comes from a mouse model of AD, however, and does not establish this correlation in the human AD brain. (LLM, conf=0.85)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    CCR2+ mononuclear cells are recruited to the inflamed hippocampus and associate with amyloid plaques in a CCR2-dependent manner.

    “Previously we showed that CCR2+ mononuclear cells are recruited to the inflamed hippocampus and associate with amyloid plaques in a CCR2-dependent manner [28].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [28] Rivera-Escalera F, Matousek SB, Ghosh S, Olschowka JA, O'Banion MK. Interleukin-1beta mediated amyloid plaque clearance is independent of CCR2 signaling in the APP/PS1 mouse model of Alzheimer’s disease. Neurobiol Dis. 2014;69:124–33. source

  • Classified as probably not a substantial claim.

    Premisecitation

    Microglial phagocytosis is believed to be dysfunctional in AD.

    “Microglial phagocytosis is believed to be dysfunctional in AD [17–19].”
    Quote in the paperSubstantial claim1 of 3 sources checked
    • cites [17] Frackowiak J, Wisniewski HM, Wegiel J, Merz GS, Iqbal K, Wang KC. Ultrastructure of the microglia that phagocytose amyloid and the microglia that produce beta-amyloid fibrils. Acta Neuropathol. 1992;84:225–33. source
    • cites [18] Krabbe G, Halle A, Matyash V, Rinnenthal JL, Eom GD, Bernhardt U, Miller KR, Prokop S, Kettenmann H, Heppner FL. Functional impairment of microglia coincides with Beta-amyloid deposition in mice with Alzheimer-like pathology. PLoS One. 2013;8:e60921. source
    • cites [19] Wisniewski HM, Vorbrodt AW, Wegiel J, Morys J, Lossinsky AS. Ultrastructure of the cells forming amyloid fibers in Alzheimer disease and scrapie. Am J Med Genet Suppl. 1990;7:287–97.

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Defects in the phagocytic function of microglia can be restored with Aβ immunization and anti-inflammatory drug treatment.

    “However, several studies have shown that defects in the phagocytic function of microglia can be restored with Aβ immunization [18, 23] and anti-inflammatory drug treatment [24, 25].”
    Quote in the paperNot a substantial claim3 of 4 sources checked
    • cites [18] Krabbe G, Halle A, Matyash V, Rinnenthal JL, Eom GD, Bernhardt U, Miller KR, Prokop S, Kettenmann H, Heppner FL. Functional impairment of microglia coincides with Beta-amyloid deposition in mice with Alzheimer-like pathology. PLoS One. 2013;8:e60921. source
    • cites [23] Nicoll JA, Wilkinson D, Holmes C, Steart P, Markham H, Weller RO. Neuropathology of human Alzheimer disease after immunization with amyloid-beta peptide: a case report. Nat Med. 2003;9:448–52. source
    • cites [24] Yamanaka M, Ishikawa T, Griep A, Axt D, Kummer MP, Heneka MT. PPARgamma/RXRalpha-induced and CD36-mediated microglial amyloid-beta phagocytosis results in cognitive improvement in amyloid precursor protein/presenilin 1 mice. J Neurosci. 2012;32:17321–31. source
    • cites [25] Mandrekar-Colucci S, Karlo JC, Landreth GE. Mechanisms underlying the rapid peroxisome proliferator-activated receptor-gamma-mediated amyloid clearance and reversal of cognitive deficits in a murine model of Alzheimer’s disease. J Neurosci. 2012;32:10117–28. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Neutrophils modulate Alzheimer's disease pathology.

    “neutrophils have been shown to modulate Alzheimer’s disease pathology [52, 53].”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites [52] Baik SH, Cha M-Y, Hyun Y-M, Cho H, Hamza B, Kim DK, Han S-H, Choi H, Kim KH, Moon M, et al. Migration of neutrophils targeting amyloid plaques in Alzheimer's disease mouse model. Neurobiol Aging. 2014;35:1286–92. source

      The Introduction and Results (page numbers unavailable) show that neutrophils migrate toward amyloid plaques in an Alzheimer’s disease mouse model. The Discussion (page number unavailable) says they might influence disease progression, but whether they are protective or detrimental remains unknown. The paper therefore does not show that neutrophils modulate pathology, as the citing sentence states. (LLM, conf=0.88)

      Experimental — accuracy not yet measured
    • cites [53] Zenaro E, Pietronigro E, Bianca VD, Piacentino G, Marongiu L, Budui S, Turano E, Rossi B, Angiari S, Dusi S, et al. Neutrophils promote Alzheimer's disease–like pathology and cognitive decline via LFA-1 integrin. Nat Med. 2015;21:880–6. source

  • Classified as probably not a substantial claim.

    Premisecitation

    CSF-1, IL-34, and TGF-β1 have been shown to play important roles in microglial proliferation and/or survival.

    “because these cytokines have been shown to play important roles in microglial proliferation and/or survival [43, 44].”
    Quote in the paperSubstantial claim2 of 2 sources checked
    • cites [43] Butovsky O, Jedrychowski MP, Moore CS, Cialic R, Lanser AJ, Gabriely G, Koeglsperger T, Dake B, Wu PM, Doykan CE, et al. Identification of a unique TGF-beta-dependent molecular and functional signature in microglia. Nat Neurosci. 2014;17:131–43. source

      The Results sections on microglial development in vivo and in vitro (pages unavailable) support roles for TGF-β1 and MCSF (CSF-1): CNS TGF-β1 deficiency was associated with microglial loss and increased apoptosis, while adult microglia did not survive in culture with TGF-β1 alone rather than with MCSF. No passage found for IL-34 supports its role in microglial proliferation or survival (searched: IL-34 and the three cytokines together). (LLM, conf=0.87)

      Experimental — accuracy not yet measured
    • cites [44] Elmore MR, Najafi AR, Koike MA, Dagher NN, Spangenberg EE, Rice RA, Kitazawa M, Matusow B, Nguyen H, West BL, Green KN. Colony-stimulating factor 1 receptor signaling is necessary for microglia viability, unmasking a microglia progenitor cell in the adult brain. Neuron. 2014;82:380–97. source

      The Discussion ('Dependence of microglia on CSF1R signaling in the adult brain'; page not supplied) reports reduced microglial densities in mice lacking CSF-1 or IL-34 and finds that adult microglia depend on CSF1R signaling for survival. Our copy does not establish a role for TGF-β1 in microglial proliferation or survival; its References list a TGF-β1 study concerning macrophages instead. (LLM, conf=0.88)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Microglial activation plays a beneficial role in early stages of AD pathology but contributes to disease worsening in late stages of AD.

    “several studies have suggested that microglial activation plays a beneficial role in early stages of AD pathology, but contributes to disease worsening in late stages of AD [66–68].”
    Quote in the paperNot a substantial claim3 of 3 sources checked
    • cites [66] Jimenez S, Baglietto-Vargas D, Caballero C, Moreno-Gonzalez I, Torres M, Sanchez-Varo R, Ruano D, Vizuete M, Gutierrez A, Vitorica J. Inflammatory response in the hippocampus of PS1M146L/APP751SL mouse model of Alzheimer’s disease: age-dependent switch in the microglial phenotype from alternative to classic. J Neurosci. 2008;28:11650–61. source
    • cites [67] Navarro V, Sanchez-Mejias E, Jimenez S, Munoz-Castro C, Sanchez-Varo R, Davila JC, Vizuete M, Gutierrez A, Vitorica J. Microglia in Alzheimer’s disease: activated, dysfunctional or degenerative. Front Aging Neurosci. 2018;10:140. source

      The section ‘Decoding Microglial Activation in Mouse Models and Human Brains’ says plaque-associated activation could be protective, though that role is under debate. For late-stage human AD, the paper instead describes attenuated activation and microglial degeneration (Figure 2; ‘Microglial Deterioration in the Hippocampus of AD Patients’). It does not support the claim that activation itself worsens disease in late stages. (LLM, conf=0.87)

      Experimental — accuracy not yet measured
    • cites [68] Shen Z, Bao X, Wang R. Clinical PET imaging of microglial activation: implications for microglial therapeutics in Alzheimer’s disease. Front Aging Neurosci. 2018;10:314. source

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    CD45 is differentially expressed on microglia (CD45lo/CD11b+) and recruited myeloid cells (CD45hi/CD11b+), and this distinction is commonly used in flow cytometry to distinguish recruited myeloid cells from resident microglia in various disease states.

    “CD45 is differentially expressed on microglia (CD45lo/CD11b+) and recruited myeloid cells (CD45hi/CD11b+), and this distinction is commonly used in flow cytometry experiments to distinguish recruited myeloid cells from resident microglia in various disease states [27, 40, 41].”
    Quote in the paperSubstantial claim3 of 3 sources checked
    • cites [27] Fu AK, Hung KW, Yuen MY, Zhou X, Mak DS, Chan IC, Cheung TH, Zhang B, Fu WY, Liew FY, Ip NY. IL-33 ameliorates Alzheimer's disease-like pathology and cognitive decline. Proc Natl Acad Sci U S A. 2016;113:E2705–13. source

      Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

      Experimental — accuracy not yet measured
    • cites [40] Jay TR, Miller CM, Cheng PJ, Graham LC, Bemiller S, Broihier ML, Xu G, Margevicius D, Karlo JC, Sousa GL, et al. TREM2 deficiency eliminates TREM2+ inflammatory macrophages and ameliorates pathology in Alzheimer’s disease mouse models. J Exp Med. 2015;212:287–95. source
    • cites [41] Ritzel RM, Patel AR, Grenier JM, Crapser J, Verma R, Jellison ER, McCullough LD. Functional differences between microglia and monocytes after ischemic stroke. J Neuroinflammation. 2015;12:106. source

      Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Increases in the resident microglial population under inflammatory conditions can be supported by local self-proliferation and this proliferation depends on CSF1R signaling.

    “It has been reported that increases in the resident microglial population under inflammatory conditions can be supported by local self-proliferation and that this proliferation depends on CSF1R signaling [42].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [42] Gomez-Nicola D, Fransen NL, Suzzi S, Perry VH. Regulation of microglial proliferation during chronic neurodegeneration. J Neurosci. 2013;33:2481–93. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Astrocytes can modulate microglial responses to Aβ.

    “Moreover, astrocytes can also modulate microglial responses to Aβ [55, 58, 59].”
    Quote in the paperNot a substantial claim2 of 3 sources checked
    • cites [55] Kraft AW, Hu X, Yoon H, Yan P, Xiao Q, Wang Y, Gil SC, Brown J, Wilhelmsson U, Restivo JL, et al. Attenuating astrocyte activation accelerates plaque pathogenesis in APP/PS1 mice. Faseb J. 2013;27:187–98. source
    • cites [58] Lian H, Litvinchuk A, Chiang AC, Aithmitti N, Jankowsky JL, Zheng H. Astrocyte-Microglia cross talk through complement activation modulates amyloid pathology in mouse models of Alzheimer’s disease. J Neurosci. 2016;36:577–89. source
    • cites [59] DeWitt DA, Perry G, Cohen M, Doller C, Silver J. Astrocytes regulate microglial phagocytosis of senile plaque cores of Alzheimer’s disease. Exp Neurol. 1998;149:329–40. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    IL-1β induces recruitment of CD4+ and CD8+ T cells.

    “we have previously shown that IL-1β induces recruitment of CD4+ and CD8+ T cells [30].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [30] Shaftel SS, Carlson TJ, Olschowka JA, Kyrkanides S, Matousek SB, O'Banion MK. Chronic interleukin-1beta expression in mouse brain leads to leukocyte infiltration and neutrophil-independent blood brain barrier permeability without overt neurodegeneration. J Neurosci. 2007;27:9301–9. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    AAV2 selectively transduces neurons and its use in the CNS is well characterized.

    “AAV2 selectively transduces neurons and its use in the CNS is well characterized [34–36].”
    Quote in the paperNot a substantial claim2 of 3 sources checked
    • cites [34] Burger C, Nash K, Mandel RJ. Recombinant adeno-associated viral vectors in the nervous system. Hum Gene Ther. 2005;16:781–91. source
    • cites [35] Janelsins MC, Mastrangelo MA, Park KM, Sudol KL, Narrow WC, Oddo S, LaFerla FM, Callahan LM, Federoff HJ, Bowers WJ. Chronic neuron-specific tumor necrosis factor-alpha expression enhances the local inflammatory environment ultimately leading to neuronal death in 3xTg-AD mice. Am J Pathol. 2008;173:1768–82. source
    • cites [36] Montgomery SL, Narrow WC, Mastrangelo MA, Olschowka JA, O'Banion MK, Bowers WJ. Chronic neuron- and age-selective down-regulation of TNF receptor expression in triple-transgenic Alzheimer disease mice leads to significant modulation of amyloid- and Tau-related pathologies. Am J Pathol. 2013;182:2285–97. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Microglial proliferation is the main contributor to increased microglial numbers under certain disease states such as ischemia, facial nerve transection, prion disease, and Alzheimer's disease.

    “Microglial proliferation has been shown to be the main contributor to increased microglial numbers under certain disease states such as ischemia, facial nerve transection, prion disease, and Alzheimer’s disease [42, 61–64].”
    Quote in the paperNot a substantial claim3 of 5 sources checked
    • cites [42] Gomez-Nicola D, Fransen NL, Suzzi S, Perry VH. Regulation of microglial proliferation during chronic neurodegeneration. J Neurosci. 2013;33:2481–93. source

      The Discussion (page not provided) concludes that local proliferation sustains the increase in microglial numbers during prion disease. The human vCJD and AD section reports evidence of microglial proliferation in Alzheimer’s disease, but does not establish that it is the main contributor to increased numbers there. Our copy does not establish that conclusion for ischemia or facial nerve transection either. (LLM, conf=0.87)

      Experimental — accuracy not yet measured
    • cites [61] Lalancette-Hebert M, Gowing G, Simard A, Weng YC, Kriz J. Selective ablation of proliferating microglial cells exacerbates ischemic injury in the brain. J Neurosci. 2007;27:2596–605. source
    • cites [62] Lalancette-Hebert M, Swarup V, Beaulieu JM, Bohacek I, Abdelhamid E, Weng YC, Sato S, Kriz J. Galectin-3 is required for resident microglia activation and proliferation in response to ischemic injury. J Neurosci. 2012;32:10383–95. source
    • cites [63] Olmos-Alonso A, Schetters ST, Sri S, Askew K, Mancuso R, Vargas-Caballero M, Holscher C, Perry VH, Gomez-Nicola D. Pharmacological targeting of CSF1R inhibits microglial proliferation and prevents the progression of Alzheimer’s-like pathology. Brain. 2016;139:891–907. source

      The Introduction (page unavailable) says expansion of the microglial population during neurodegeneration depends almost exclusively on proliferation of resident cells, and discusses prion disease and Alzheimer’s disease. The Results (page unavailable) also document increased microglial numbers and proliferation in Alzheimer’s disease. Our copy does not establish the same claim for ischemia or facial nerve transection. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites [64] Tay TL, Mai D, Dautzenberg J, Fernandez-Klett F, Lin G, Sagar, Datta M, Drougard A, Stempfl T, Ardura-Fabregat A, et al. A new fate mapping system reveals context-dependent random or clonal expansion of microglia. Nat Neurosci. 2017;20:793–803. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    IL-1β induces significant recruitment of neutrophils.

    “Previous work from our lab has shown that IL-1β induces significant recruitment of neutrophils [30]”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [30] Shaftel SS, Carlson TJ, Olschowka JA, Kyrkanides S, Matousek SB, O'Banion MK. Chronic interleukin-1beta expression in mouse brain leads to leukocyte infiltration and neutrophil-independent blood brain barrier permeability without overt neurodegeneration. J Neurosci. 2007;27:9301–9. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Astrocytes restrict amyloid pathology.

    “astrocytes have been shown to restrict amyloid pathology [55–57].”
    Quote in the paperNot a substantial claim2 of 3 sources checked
    • cites [55] Kraft AW, Hu X, Yoon H, Yan P, Xiao Q, Wang Y, Gil SC, Brown J, Wilhelmsson U, Restivo JL, et al. Attenuating astrocyte activation accelerates plaque pathogenesis in APP/PS1 mice. Faseb J. 2013;27:187–98. source
    • cites [56] Pihlaja R, Koistinaho J, Kauppinen R, Sandholm J, Tanila H, Koistinaho M. Multiple cellular and molecular mechanisms are involved in human Abeta clearance by transplanted adult astrocytes. Glia. 2011;59:1643–57. source
    • cites [57] Xiao Q, Yan P, Ma X, Liu H, Perez R, Zhu A, Gonzales E, Burchett JM, Schuler DR, Cirrito JR, et al. Enhancing astrocytic lysosome biogenesis facilitates Abeta clearance and attenuates amyloid plaque pathogenesis. J Neurosci. 2014;34:9607–20. source

  • May combine two claims.

    Findingown data

    IL-1β reduced fibrillar and total amyloid plaque burden regardless of sex in APP/PS1 mice.

    “IL-1β reduced fibrillar and total amyloid plaque burden regardless of sex (Additional file 1).”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    Approximately 8% of hippocampal microglia were MX04+ in both control- and IL-1β-treated APP/PS1 mice.

    “Flow cytometry analysis revealed that approximately 8% of hippocampal microglia were MX04+ in both control- and IL-1β-treated mice (Fig. 3a)”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    IL-1β increases levels of CSF-1 and TGF-β1.

    “Our studies showed that IL-1β increased the total number of microglial cells by inducing microglial proliferation, concomitant with increased levels of CSF-1 and TGF-β1.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Microglia were manually counted by a blinded investigator.

    “which were manually counted by a blinded investigator.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    GAPDH was used as a housekeeping gene to normalize the calculated quantities of mRNA for the gene of interest.

    “GAPDH was used as a housekeeping to normalize the calculated quantities of mRNA for the gene of interest.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The findings are consistent with a study that found no change in Aβ phagocytosis in microglia producing IL-1β.

    “These findings are consistent with a study that found no change in Aβ phagocytosis in microglia producing the cytokine IL-1β [20].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] Babcock AA, Ilkjaer L, Clausen BH, Villadsen B, Dissing-Olesen L, Bendixen AT, Lyck L, Lambertsen KL, Finsen B. Cytokine-producing microglia have an altered beta-amyloid load in aged APP/PS1 Tg mice. Brain Behav Immun. 2015;48:86–101. source

  • May combine two claims.

    Interpretationown data

    IL-1β overexpression early in amyloid pathogenesis induces a change in the microglial gene expression profile and an expansion of microglial cells that facilitates Aβ plaque clearance.

    “These studies show that IL-1β overexpression early in amyloid pathogenesis induces a change in the microglial gene expression profile and an expansion of microglial cells that facilitates Aβ plaque clearance.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Two biological replicates of pooled cells from 6 to 8 APP/PS1 mouse hippocampi were sequenced for each experimental group.

    “Two biological replicates of pooled cells from 6 to 8 APP/PS1 mouse hippocampi were sequenced for each experimental group.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Multiple t tests were corrected for multiple comparisons using the Holm-Sidak method.

    “Multiple t tests were corrected for multiple comparisons using the Holm-Sidak method.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    Genes were considered differentially expressed if q-value < 0.05 and log2 |fold change| ≥ 1.

    “Genes were considered differentially expressed if q-value (p value corrected for multiple testing) < 0.05 and had a log2 |fold change| ≥ 1.”
    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

    Both female and male mice were used to balance sex across experimental conditions, and equal numbers of female and male mice were attempted in all experiments.

    “Both female and male mice were used to balance sex across our experimental conditions, and we tried to maintain equal numbers of female and male mice in all of our experiments.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    All animal procedures were reviewed and approved by the University of Rochester Committee on Animal Resources for compliance with federal regulations before the initiation of this study.

    “All animal procedures were reviewed and approved by the University of Rochester Committee on Animal Resources for compliance with federal regulations before the initiation of this study.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    Flow cytometry gating excluded debris, cell doublets, and dead cells.

    “after gating to exclude debris, cell doublets, and dead cells (Fig. 2a, b).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    The flow cytometry analysis did not distinguish between different CD45hi myeloid and lymphoid populations, or other brain resident populations such as astrocytes.

    “One caveat of our flow cytometry analysis is that it did not distinguish between different CD45hi myeloid and lymphoid populations, or other brain resident populations such as astrocytes.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Microglia may facilitate Aβ clearance either directly by local self-proliferation and/or by the interplay of these gene expression changes.

    “and that microglia may facilitate Aβ clearance either directly by local self-proliferation and/or by the interplay of these gene expression changes.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    BrdU staining for flow cytometry was not compatible with the MX04 signal, so no conclusions could be made on Aβ internalization in BrdU+ microglial cells.

    “Unfortunately, the BrdU staining for flow cytometry was not compatible with the MX04 signal, thus we were not able to make any conclusions on Aβ internalization in BrdU+ microglial cells.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Methoxy-X04 labels fibrillar amyloid beta plaques.

    “Three days prior to sacrifice, APP/PS1 mice received an intraperitoneal (i.p.) injection of methoxy-X04 (MX04) (10 mg/kg, Tocris) to label fibrillar amyloid beta plaques [37].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [37] Klunk WE, Bacskai BJ, Mathis CA, Kajdasz ST, McLellan ME, Frosch MP, Debnath ML, Holt DP, Wang Y, Hyman BT. Imaging Abeta plaques in living transgenic mice with multiphoton microscopy and methoxy-X04, a systemically administered Congo red derivative. J Neuropathol Exp Neurol. 2002:797–805. source
33 of 33

  • The paper relies on this without support.

    The decrease in pre-labeled MX04+ plaques following IL-1β overexpression reflects clearance of existing plaques rather than loss of MX04 labeling or other changes.

    “In addition, we found that pre-labeled MX04+ amyloid plaques were significantly decreased following IL-1β overexpression, suggesting that IL-1β drives reductions in existing amyloid plaques (see Additional file 2).”
1 of 1

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.

  • Fig. 5 panel c is assigned to two different analyses

    Minor

    The caption describes panel c as images and quantification of BrdU+ plaque-associated microglia, then assigns the Csf1r qRT-PCR result to panel c as well.

  • qRT-PCR target is labeled Csf1r instead of Csf1

    Minor

    The methods list an assay for Csf1, while the Fig. 5 caption identifies the corresponding measured transcript as Csf1r. These are different genes.

  • Viral vector is identified as both adenoviral and adeno-associated

    Minor

    The abstract calls the delivery adenoviral transduction, whereas the methods identify the vector produced for the study as recombinant adeno-associated virus serotype 2.

3 of 3

Cites

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Authors
Rivera-Escalera, F., Pinney, J. J., Owlett, L., Ahmed, H., Thakar, J., Olschowka, J. A., Elliott, M. R., & O’Banion, M. K.
Affiliations
University of Rochester Medicine (US)
Corresponding author
O’Banion, M. Kerry
ORCID
Venue
Journal of Neuroinflammation
Publisher
Springer Science and Business Media LLC
Published
2019-12
Volume
16
Issue
1
Pages
261-261
ISSN
1742-2094 (ISSN-L)
DOI
10.1186/s12974-019-1645-7
PMC
PMC6902486
OpenAlex
W2995426022
Semantic Scholar
b6dc033d2c6cc951561a46205bdd4564fb140a78
Cited by
75
References
96
Citations by year
2026: 4 · 2025: 7 · 2024: 10 · 2023: 12 · 2022: 27 · 2021: 10 · 2020: 5
FWCI
3.88
Type
journal article
Language
en
Open access
Licence
Locations
  • Journal of Neuroinflammation (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • PubMed Central (submittedVersion, cc-by)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
Funders
National Institute on Aging (RO1 AG030149)
Topics
  • Life Sciences › Neuroscience › Neurology › Neuroinflammation and Neurodegeneration Mechanisms
  • Health Sciences › Medicine › Physiology › Alzheimer's disease research and treatments
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Inflammasome and immune disorders
Keywords
IL-1β, amyloid plaque clearance, microglia, Alzheimer's disease, neuroinflammation, APP/PS1 mice, hippocampus, microglial proliferation, microglial gene expression, myeloid cell recruitment, CCR2
MeSH terms
Animals, Female, Male, Mice, Inbred C57BL, Mice, Transgenic, Transcription, Genetic, Microglia, Cell Proliferation, Mice, Interleukin-1beta, Plaque, Amyloid, Transcriptome, Cellular Reprogramming

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 2026-10-20.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-20.

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.

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