Alzheimer’s disease-associated protective variant Plcg2-P522R modulates peripheral macrophage function in a sex-dimorphic manner

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

PLCG2 supports numerous myeloid cell functions including phagocytosis, cytokine secretion, survival, and lipid metabolism.

“PLCG2 has been shown to support numerous myeloid cell functions including phagocytosis, cytokine secretion, survival, and lipid metabolism [10].”

• cites [10] Magno L, Bunney TD, Mead E, Svensson F, Bictash MN. TREM2/PLCγ2 signalling in immune cells: function, structural insight, and potential therapeutic modulation. Mol Neurodegener. 2021;16(1):22. https://doi.org/10.1186/s13024-021-00436-5. Published 2021 Apr 6. sourceSupported

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

The gut has been identified as a peripheral reservoir for Aβ.

“Furthermore, the immune cells of the peritoneum are of great interest in relation to the gut, which has been identified as a peripheral reservoir for Aβ, and as a conduit of peripheral messengers to the brain via the gut-brain-axis [22, 33].”

• cites [22] Wang J, Gu BJ, Masters CL, Wang YJ. A systemic view of Alzheimer disease — insights from amyloid-β metabolism beyond the brain. Nat Rev Neurol. 2017;13(10):612–23. https://doi.org/10.1038/nrneurol.2017.111. sourceNot checked — no full text of the source
• cites [33] Kowalski K, Mulak A. Brain-gut-microbiota axis in alzheimer’s disease. J Neurogastroenterol Motil. 2019;25(1):48–60. https://doi.org/10.5056/jnm18087. sourcePartly supported

  The Amyloid Plaque Formation > Enteric Nervous System section reports Aβ accumulation in the enteric neurons of APP transgenic mice, supporting the narrower point that Aβ can be present in the gut. It does not identify the gut as a peripheral Aβ reservoir generally. The Bacterial Amyloids section describes gut-microbial amyloids, but distinguishes them from Aβ. (LLM, conf=0.85)

  Experimental — accuracy not yet measured

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

LPMs are resident to the peritoneal cavity.

“In broad terms, LPMs are known to be resident to the peritoneal cavity, and SPMs are derived from blood-monocytes, which travel to the peritoneal cavity upon infection or other inflammatory events [29].”

• cites [29] Cassado Ados A, D’Império Lima MR, Bortoluci KR. Revisiting mouse peritoneal macrophages: heterogeneity, development, and function. Front Immunol. 2015;6:225. Published 2015 May 19. https://doi.org/10.3389/fimmu.2015.00225. sourceSupported

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

The P522R mutation has variable effects on phagocytosis by microglia depending on cargo size.

“Studies have shown that the P522R mutation increases the release of inflammatory cytokines by microglia, and has variable effects on phagocytosis depending on cargo size [13].”

• cites [13] Takalo M, Wittrahm R, Wefers B, et al. The Alzheimer’s disease-associated protective Plcγ2-P522R variant promotes immune functions. Mol Neurodegener. 2020;15(1):52. https://doi.org/10.1186/s13024-020-00402-7. Published 2020 Sep 11. sourcePartly supported

  The Findings section reports increased phagocytic activity in P522R-expressing BV2 microglia-like cells, but does not report that the effect varies with cargo size. It also reports increased inflammatory cytokine release from stimulated bone marrow-derived macrophages, not microglia. The Methods describe the phagocytosis cargo used in each assay without comparing cargo sizes; page numbers are unavailable in our copy. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

May combine two claims.

Peripherally derived Aβ enters the brain and exacerbates neuropathology.

“Furthermore, peripherally derived Aβ has been shown to enter the brain and exacerbate neuropathology, further supporting the importance of peripheral Aβ stores and clearance [25].”

• cites [25] Eisele YS, Obermüller U, Heilbronner G, et al. Peripherally applied aβ-containing inoculates induce cerebral β-amyloidosis. Science. 2010;330(6006):980–2. https://doi.org/10.1126/science.1194516. sourcePartly supported

  The paper reports that intraperitoneal injection of Aβ-rich brain extract induced cerebral β-amyloidosis and associated pathologies in APP23 mice (Abstract; no page provided). It says the injected material was likely carried to the brain, but does not demonstrate its entry or establish that naturally occurring peripheral Aβ stores have the same effect. (LLM, conf=0.85)

  Experimental — accuracy not yet measured

May combine two claims.

The insular cortex can store immune-related information and alter the peripheral immune response if reactivated.

“Not only that, but immune responses occurring in this region have been shown to directly activate the brain’s insular cortex, a region known to be affected during the preclinical stages of AD [34], which can in turn store this immune-related information and alter the peripheral immune response if reactivated, further supporting a direct connection between the brain and peritoneum [35].”

• cites [35] Koren T, Yifa R, Amer M, et al. Insular cortex neurons encode and retrieve specific immune responses. Cell. 2021;184(24):5902–e591517. https://doi.org/10.1016/j.cell.2021.10.013. sourceSupported

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

PLCG2 acts downstream of TREM2 and TLRs to cleave PIP2 into DAG and IP3.

“To do so, it acts downstream of receptors such as triggering receptor expressed on myeloid cells 2 (TREM2) and toll-like receptors (TLRs) to cleave phosphatidylinositol 4,5 bisphosphate (PIP2) into diacylglycerol (DAG) and inositol 1,4,5 triphosphate (IP3).”

• cites [10] Magno L, Bunney TD, Mead E, Svensson F, Bictash MN. TREM2/PLCγ2 signalling in immune cells: function, structural insight, and potential therapeutic modulation. Mol Neurodegener. 2021;16(1):22. https://doi.org/10.1186/s13024-021-00436-5. Published 2021 Apr 6. sourcePartly supported

  The section “Microglia signalling networks: linking TREM2 to PLCγ2” states that activated PLCγ2 hydrolyses PIP2 into IP3 and DAG, and describes PLCγ2 signalling downstream of TREM2. The section “The role of TREM2 and PLCG2 in immune cell biology” mentions TLR-induced responses, but does not establish that PLCγ2 acts downstream of TLRs. (LLM, conf=0.87)

  Experimental — accuracy not yet measured
• cites [11] Andreone BJ, Przybyla L, Llapashtica C, et al. Alzheimer’s-associated PLCγ2 is a signaling node required for both TREM2 function and the inflammatory response in human microglia. Nat Neurosci. 2020;23(8):927–38. https://doi.org/10.1038/s41593-020-0650-6. sourceNot checked — no full text of the source

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

DAG and IP3 release intracellular calcium and activate downstream pathways including NF-κB.

“DAG and IP3 go on to both release intracellular calcium and activate downstream pathways including nuclear factor light chain enhancer of activated B cells (NF-κB) [10, 11].”

• cites [10] Magno L, Bunney TD, Mead E, Svensson F, Bictash MN. TREM2/PLCγ2 signalling in immune cells: function, structural insight, and potential therapeutic modulation. Mol Neurodegener. 2021;16(1):22. https://doi.org/10.1186/s13024-021-00436-5. Published 2021 Apr 6. sourcePartly supported

  The ‘Microglia signalling networks: linking TREM2 to PLCγ2’ section (page unavailable) says IP3 leads to calcium release from intracellular stores, while DAG activates PKC and other proteins. It does not identify NF-κB as a downstream pathway, and it assigns calcium release to IP3 rather than to both products. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [11] Andreone BJ, Przybyla L, Llapashtica C, et al. Alzheimer’s-associated PLCγ2 is a signaling node required for both TREM2 function and the inflammatory response in human microglia. Nat Neurosci. 2020;23(8):927–38. https://doi.org/10.1038/s41593-020-0650-6. sourceNot checked — no full text of the source

May combine two claims.

Peritoneal macrophages differentiate within the tissue, allowing them to mold to their environment and experience hormonal changes throughout the animal's lifespan.

“This population was selected over bone-marrow derived macrophages as peritoneal macrophages differentiate within the tissue, which allows them to mold to their environment and experience hormonal changes throughout the animal’s lifespan [29, 31, 32].”

• cites [29] Cassado Ados A, D’Império Lima MR, Bortoluci KR. Revisiting mouse peritoneal macrophages: heterogeneity, development, and function. Front Immunol. 2015;6:225. Published 2015 May 19. https://doi.org/10.3389/fimmu.2015.00225. sourcePartly supported

  The Abstract describes macrophage adaptation to distinct tissue environments, and “Origin and Development of LPM and SPM” says resident peritoneal macrophages are maintained locally by self-renewal throughout adult life. But the paper distinguishes embryonic-origin resident macrophages from bone-marrow-derived small peritoneal macrophages; it does not say peritoneal macrophages generally differentiate within the tissue or discuss their exposure to hormonal changes across an animal’s lifespan. Page numbers are unavailable in our copy. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites [31] Zajd CM, Ziemba AM, Miralles GM, et al. Bone marrow-derived and elicited peritoneal macrophages are not created equal: the questions asked dictate the cell type used. Front Immunol. 2020;11. https://doi.org/10.3389/fimmu.2020.00269. sourcePartly supported

  The Introduction and Discussion state that peritoneal macrophages differentiate in vivo and that their phenotype is shaped by the animal’s environment. Our copy does not say that they experience hormonal changes throughout the animal’s lifespan, so that specific part of the claim is unsupported. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [32] Wang C, Yu X, Cao Q, et al. Characterization of murine macrophages from bone marrow, spleen and peritoneum. BMC Immunol. 2013;14(1). https://doi.org/10.1186/1471-2172-14-6. sourcePartly supported

  The Discussion says peritoneal macrophages are obtained directly from the peritoneum, unlike bone-marrow-derived macrophages that can be fully differentiated in vitro. The Background also suggests that conditions in the peritoneal cavity may contribute to their distinct characteristics. Neither section establishes that peritoneal macrophages differentiate within the tissue or experience hormonal changes throughout the animal’s lifespan. (LLM, conf=0.83)

  Experimental — accuracy not yet measured

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

The P522R mutation increases the release of inflammatory cytokines by microglia.

“Studies have shown that the P522R mutation increases the release of inflammatory cytokines by microglia, and has variable effects on phagocytosis depending on cargo size [13].”

• cites [13] Takalo M, Wittrahm R, Wefers B, et al. The Alzheimer’s disease-associated protective Plcγ2-P522R variant promotes immune functions. Mol Neurodegener. 2020;15(1):52. https://doi.org/10.1186/s13024-020-00402-7. Published 2020 Sep 11. sourcePartly supported

  The Findings section reports increased TNFα, IL-6, and IL-1β release from P522R knock-in bone marrow-derived macrophages after LPS and IFNγ stimulation, not from microglia. It reports increased phagocytosis in BV2 microglia-like cells, but does not establish that the effect varies with cargo size. (LLM, conf=0.87)

  Experimental — accuracy not yet measured

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

SPMs are derived from blood monocytes, which travel to the peritoneal cavity upon infection or other inflammatory events.

“In broad terms, LPMs are known to be resident to the peritoneal cavity, and SPMs are derived from blood-monocytes, which travel to the peritoneal cavity upon infection or other inflammatory events [29].”

• cites [29] Cassado Ados A, D’Império Lima MR, Bortoluci KR. Revisiting mouse peritoneal macrophages: heterogeneity, development, and function. Front Immunol. 2015;6:225. Published 2015 May 19. https://doi.org/10.3389/fimmu.2015.00225. sourceSupported

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

The gut has been identified as a conduit of peripheral messengers to the brain via the gut-brain-axis.

“Furthermore, the immune cells of the peritoneum are of great interest in relation to the gut, which has been identified as a peripheral reservoir for Aβ, and as a conduit of peripheral messengers to the brain via the gut-brain-axis [22, 33].”

• cites [22] Wang J, Gu BJ, Masters CL, Wang YJ. A systemic view of Alzheimer disease — insights from amyloid-β metabolism beyond the brain. Nat Rev Neurol. 2017;13(10):612–23. https://doi.org/10.1038/nrneurol.2017.111. sourceNot checked — no full text of the source
• cites [33] Kowalski K, Mulak A. Brain-gut-microbiota axis in alzheimer’s disease. J Neurogastroenterol Motil. 2019;25(1):48–60. https://doi.org/10.5056/jnm18087. sourceSupported

Classified as probably not a substantial claim.

Recruited monocytes can, over time, differentiate into macrophages that closely mimic resident LPMs.

“Recent studies have shown that these recruited monocytes can, over time, differentiate into macrophages that closely mimic the resident LPMs [30].”

• cites [30] Bain CC, Hawley CA, Garner H, et al. Long-lived self-renewing bone marrow-derived macrophages displace embryo-derived cells to inhabit adult serous cavities. Nat Commun. 2016;7:ncomms11852. https://doi.org/10.1038/ncomms11852. Published 2016 Jun 13. sourceSupported

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

Many of these pathways involve calcium signaling, and the calcineurin cascade which in macrophages has been shown to down-regulate TLR mediated activation pathways.

“Many of these pathways involve calcium signaling, and the calcineurin cascade which in macrophages has been shown to down-regulate TLR mediated activation pathways [43].”

• cites [43] Kang YJ, Kusler B, Otsuka M, et al. Calcineurin negatively regulates tlr-mediated activation pathways. J Immunol. 2007;179(7):4598–607. https://doi.org/10.4049/jimmunol.179.7.4598. sourceSupported

Classified as probably not a substantial claim.

Flow cytometry using CD11b expression distinguishes SPMs from LPMs, as previously described.

“we isolated pMacs from the peritoneal cavity of male mice, and then used flow cytometry to distinguish SPMs from LPMs on the basis of CD11b expression, as has been previously described (Supplemental Fig. 1A) [39].”

• cites [39] Ghosn EE, Cassado AA, Govoni GR, et al. Two physically, functionally, and developmentally distinct peritoneal macrophage subsets. Proc Natl Acad Sci U S A. 2010;107(6):2568–73. https://doi.org/10.1073/pnas.0915000107. sourceSupported

• AssumptionRests on an assumption: Peritoneal macrophages are a heterogeneous population, with small peritoneal macrophages (SPMs) arising from blood monocytes and large peritoneal macrophages (LPMs) resident to the peritoneal cavity.

Classified as probably not a substantial claim.

There are distinct sex-differences in pMac populations.

“Based on the literature indicating distinct sex-differences in pMac populations, we aimed to determine whether the P522R mutation would have similar effects on population frequencies and antigen presentation in female mice as was seen in male mice [40].”

• cites [40] Bain CC, Gibson DA, Steers NJ, et al. Rate of replenishment and microenvironment contribute to the sexually dimorphic phenotype and function of peritoneal macrophages. Sci Immunol. 2020;5(48):eabc4466. https://doi.org/10.1126/sciimmunol.abc4466. sourceSupported

Classified as probably not a substantial claim.

Chronic inflammatory cytokines can exacerbate neurodegeneration.

“which, when chronic, can exacerbate neurodegeneration [2–4]”

• cites [2] Cunningham C, Campion S, Lunnon K, et al. Systemic inflammation induces acute behavioral and cognitive changes and accelerates neurodegenerative disease. Biol Psychiatry. 2009;65(4):304–12. https://doi.org/10.1016/j.biopsych.2008.07.024. sourcePartly supported

  The Abstract Conclusions report that transient systemic inflammation accelerates neurodegenerative disease, and the Discussion Conclusion cites evidence that systemic IL-1β exacerbates neurodegeneration. Neither passage establishes that chronic exposure to inflammatory cytokines causes the exacerbation; the paper says its mechanism remains unclear. Page numbers are unavailable in our copy. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [3] Tejera D, Mercan D, Sanchez-Caro JM, et al. Systemic inflammation impairs microglial Aβ clearance through NLRP3 inflammasome. EMBO J. 2019;38(17):e101064. https://doi.org/10.15252/embj.2018101064. sourceSupported
• cites [4] Marshall JS, Warrington R, Watson W, Kim HL. An introduction to immunology and immunopathology. Allergy Asthma Clin Immunol. 2018;14(Suppl 2):49. Published 2018 Sep 12. https://doi.org/10.1186/s13223-018-0278-1. sourcePartly supported

  The Immunopathology > Inflammation section says that overproduction of inflammatory cytokines drives inflammation and that poorly regulated inflammation can cause tissue damage. It does not address neurodegeneration, so it does not support that specific consequence (searched: neurodegeneration, neurodegenerative, brain, neurons). (LLM, conf=0.78)

  Experimental — accuracy not yet measured

Classified as probably not a substantial claim.

Macrophages are one of the main producers of inflammatory cytokines.

“macrophages are known to be one of the main producers of inflammatory cytokines”

• cites [2] Cunningham C, Campion S, Lunnon K, et al. Systemic inflammation induces acute behavioral and cognitive changes and accelerates neurodegenerative disease. Biol Psychiatry. 2009;65(4):304–12. https://doi.org/10.1016/j.biopsych.2008.07.024. sourcePartly supported

  The Discussion (Exaggerated Sickness Behavior and Microglial Priming; page unavailable) reports IL-1β production by hippocampal microglia after systemic LPS challenge. The paper does not establish that macrophages generally are among the main producers of inflammatory cytokines; its finding concerns microglia under a specific condition. (LLM, conf=0.78)

  Experimental — accuracy not yet measured
• cites [3] Tejera D, Mercan D, Sanchez-Caro JM, et al. Systemic inflammation impairs microglial Aβ clearance through NLRP3 inflammasome. EMBO J. 2019;38(17):e101064. https://doi.org/10.15252/embj.2018101064. sourcePartly supported

  The Introduction and Discussion describe activated microglia releasing inflammatory cytokines, supporting the cytokine-production part of the claim. The paper focuses on microglia in the brain; it does not establish that macrophages generally are among the main producers of inflammatory cytokines. The indexed passages provide section labels but no page numbers. (LLM, conf=0.81)

  Experimental — accuracy not yet measured
• cites [4] Marshall JS, Warrington R, Watson W, Kim HL. An introduction to immunology and immunopathology. Allergy Asthma Clin Immunol. 2018;14(Suppl 2):49. Published 2018 Sep 12. https://doi.org/10.1186/s13223-018-0278-1. sourceCould not verify

  The Innate immunity section identifies macrophages as innate immune cells and discusses inflammatory cytokine production, but does not identify macrophages as producers of those cytokines. Searches for macrophages as major producers of inflammatory cytokines found no passage making that connection or ranking their contribution. (LLM, conf=0.70)

  Experimental — accuracy not yet measured

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

Peripheral monocytes and tissue-resident macrophages participate in Aβ plaque uptake, both around the brain and in peripheral tissue reservoirs.

“This includes evidence that peripheral monocytes and tissue-resident macrophages participate in Aβ plaque uptake, both around the brain and in peripheral tissue reservoirs [22–24].”

• cites [22] Wang J, Gu BJ, Masters CL, Wang YJ. A systemic view of Alzheimer disease — insights from amyloid-β metabolism beyond the brain. Nat Rev Neurol. 2017;13(10):612–23. https://doi.org/10.1038/nrneurol.2017.111. sourceNot checked — no full text of the source
• cites [23] Qosa H, Abuasal BS, Romero IA, et al. Differences in amyloid-β clearance across mouse and human blood–brain barrier models: kinetic analysis and mechanistic modeling. Neuropharmacology. 2014;79:668–78. https://doi.org/10.1016/j.neuropharm.2014.01.023. sourceCould not verify

  The Results (§3.3) report Aβ40 uptake by mouse and human brain endothelial cells, and the Discussion (§4) focuses on endothelial transport across the blood–brain barrier. Searches for monocytes, macrophages, plaque uptake, and peripheral tissue reservoirs found no passage addressing their participation. (LLM, conf=0.76)

  Experimental — accuracy not yet measured
• cites [24] Xiang Y, Bu XL, Liu YH, et al. Physiological amyloid-beta clearance in the periphery and its therapeutic potential for Alzheimer’s disease. Acta Neuropathol. 2015;130(4):487–99. https://doi.org/10.1007/s00401-015-1477-1. sourcePartly supported

  The Discussion (page unavailable) reports that monocytes can internalize Aβ, and the Results section on peripheral distribution (page unavailable) finds Aβ uptake in organs including the liver and kidney. Neither passage shows peripheral monocytes or tissue-resident macrophages taking up Aβ plaques around the brain or in peripheral tissues; the paper does not identify the cells responsible for the measured organ uptake. (LLM, conf=0.84)

  Experimental — accuracy not yet measured

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

Cytokines are main promoters of apoptosis, particularly TNF.

“as cytokines are main promoters of apoptosis, particularly TNF [48, 49].”

• cites [48] Behar SM, Martin CJ, Booty MG, et al. Apoptosis is an innate defense function of macrophages against Mycobacterium tuberculosis. Mucosal Immunol. 2011;4(3):279–87. https://doi.org/10.1038/mi.2011.3. sourcePartly supported

  In “Induction of apoptosis through the extrinsic pathway in Mtb-infected macrophages” (page not provided), the paper identifies TNF as the cytokine-dependent signal required for apoptosis in that setting. It also says a lipid-dependent signal is required, so it does not establish the broader claim that cytokines are the main promoters of apoptosis generally. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [49] Xaus J, Comalada M, Valledor AF, et al. LPS induces apoptosis in macrophages mostly through the autocrine production of TNF-α. Blood. 2000;95(12):3823–31. https://doi.org/10.1182/blood.V95.12.3823. sourceNot checked — no full text of the source

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

Tyrosine phosphorylation has been characterized as a main event following LPS stimulation in macrophages which aids in cellular activation.

“Tyrosine phosphorylation has been characterized as a main event following LPS stimulation in macrophages which aids in cellular activation [47]”

• cites [47] Weinstein SL, Gold MR, DeFranco AL. Bacterial lipopolysaccharide stimulates protein tyrosine phosphorylation in macrophages. Proc Natl Acad Sci USA. 1991;88(10):4148–52. https://doi.org/10.1073/pnas.88.10.4148. sourcePartly supported

  The Abstract (p. 4148) reports that LPS rapidly increases protein tyrosine phosphorylation in macrophages. It also reports that a tyrosine kinase inhibitor blocked both phosphorylation and release of arachidonic acid metabolites, but concludes only that phosphorylation *may* mediate that response; it does not establish as fact that phosphorylation aids cellular activation generally. (LLM, conf=0.83)

  Experimental — accuracy not yet measured

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

Recent studies have shown that SPMs can continue to alter their functional and transcriptional profiles to look more like LPMs, and even occupy that same niche over time.

“recent studies have shown that not only can SPMs continue to alter their functional and transcriptional profiles to look more like LPMs, and even occupy that same niche over time”

• cites [30] Bain CC, Hawley CA, Garner H, et al. Long-lived self-renewing bone marrow-derived macrophages displace embryo-derived cells to inhabit adult serous cavities. Nat Commun. 2016;7:ncomms11852. https://doi.org/10.1038/ncomms11852. Published 2016 Jun 13. sourcePartly supported

  The Results section, “F4/80loCSF1R+ cells are precursors of F4/80hi macrophages” (page unavailable), supports maturation of cells in the SPM-like population into F4/80hi resident macrophages over time. The Results section, “BM-derived macrophages largely phenocopy embryo macrophages” (page unavailable), shows acquisition of LPM-associated markers including GATA6 and CD102. The copy does not establish that SPMs broadly acquire LPM functional and transcriptional profiles; the Discussion says whether origin affects resident macrophage function remains to be fully determined. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [40] Bain CC, Gibson DA, Steers NJ, et al. Rate of replenishment and microenvironment contribute to the sexually dimorphic phenotype and function of peritoneal macrophages. Sci Immunol. 2020;5(48):eabc4466. https://doi.org/10.1126/sciimmunol.abc4466. sourcePartly supported

  The Results section on scRNA-seq (page unavailable) describes an intermediate transcriptional phenotype between small F4/80loMHCII+ macrophages and resident CD102+ macrophages; fate-mapping results support derivation of some resident cells from the small-cell population. The Discussion (page unavailable) treats further progression toward the long-lived resident population as a possibility, particularly in females, but says a linear progression is unlikely in males. These passages do not establish that small macrophages acquire the large macrophages’ functional profile, and the claim states the progression more definitively than the paper does. (LLM, conf=0.85)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S1 (asserted), S3 (load-bearing). May combine two claims.

The discrepancy was hypothesized to be due to the size of the cargo, with studies showing lower phagocytosis of larger particles such as zymosan and E. coli, and more phagocytosis of smaller-sized dextrans.

“This discrepancy was hypothesized to be due to the size of the cargo, with studies showing lower phagocytosis of larger particles such as zymosan and E. coli, and more phagocytosis of smaller-sized dextrans [14, 15].”

• cites [14] Maguire E, Menzies GE, Phillips T, et al. PIP2 depletion and altered endocytosis caused by expression of Alzheimer’s disease-protective variant PLCγ2 R522. EMBO J. 2021;40(17):e105603. https://doi.org/10.15252/embj.2020105603. sourcePartly supported

  The Results report reduced phagocytosis of E. coli and zymosan in R522-expressing cells, while the Discussion reports increased uptake of the smaller dextran cargo. The paper calls dextran uptake endocytosis, not phagocytosis, and does not establish cargo size as the explanation for the difference. Page numbers were not available in our copy. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [15] Solomon S, Sampathkumar NK, Carre I, et al. Heterozygous expression of the Alzheimer’s disease-protective PLCγ2 P522R variant enhances Aβ clearance while preserving synapses. Cell Mol Life Sci. 2022;79(8):453. https://doi.org/10.1007/s00018-022-04473-1. Published 2022 Jul 27. sourcePartly supported

  The Results section ('PLCγ2 P522R differential selectivity is driven by cargo size'; page not provided) reports reduced uptake of larger zymosan particles and increased uptake of smaller dextrans in PLCγ2 P522R microglia. The paper does not report an E. coli uptake result, so that example is not supported by this source. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

Classified as probably not a substantial claim.

Previous studies showed that the P522R mutation was capable of increasing cytokine secretion in microglia.

“as previous studies showed that the P522R mutation was capable of increasing cytokine secretion in microglia [13].”

• cites [13] Takalo M, Wittrahm R, Wefers B, et al. The Alzheimer’s disease-associated protective Plcγ2-P522R variant promotes immune functions. Mol Neurodegener. 2020;15(1):52. https://doi.org/10.1186/s13024-020-00402-7. Published 2020 Sep 11. sourcePartly supported

  The Findings section reports increased TNFα, IL-6, and IL-1β release from P522R knock-in bone marrow-derived macrophages after LPS and IFNγ stimulation. It separately reports signs of microglial activation, but does not show increased cytokine secretion by microglia. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

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

Canonical sub-populations LPMs and SPMs are recognized as separate groups.

“Although the canonical sub-populations known as LPMs and SPMs are recognized as separate groups [29]”

• cites [29] Cassado Ados A, D’Império Lima MR, Bortoluci KR. Revisiting mouse peritoneal macrophages: heterogeneity, development, and function. Front Immunol. 2015;6:225. Published 2015 May 19. https://doi.org/10.3389/fimmu.2015.00225. sourceSupported

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

Acute inflammatory cytokines act as messengers to brain immune cells and signals to other local immune cells.

“but when acute, act as messengers to brain immune cells and signals to other local immune cells [44–46].”

• cites [44] Dantzer R. Neuroimmune interactions: from the brain to the immune system and vice versa. Physiol Rev. 2018;98(1):477–504. https://doi.org/10.1152/physrev.00039.2016. sourceSupported
• cites [45] Jin H, Li M, Jeong E, Castro-Martinez F, Zuker CS. A body–brain circuit that regulates body inflammatory responses. Nature. 2024;630(8017):695–703. https://doi.org/10.1038/s41586-024-07469-y. sourcePartly supported

  The Discussion and “Vagal responses to immune cytokines” sections say cytokines convey inflammatory information to the brain through vagal neurons. They do not identify brain immune cells as the recipients or establish that cytokines signal to other local immune cells in this context. No page numbers are available in our copy. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [46] Zang X, Chen S, Zhu J, Ma J, Zhai Y. The emerging role of central and peripheral immune systems in neurodegenerative diseases. Front Aging Neurosci. 2022;14:872134. https://doi.org/10.3389/fnagi.2022.872134. sourcePartly supported

  The CNS sections on Microglia and Astrocytes describe cytokines acting on brain cells: Th1 cytokines drive microglial polarization, and microglial pro-inflammatory factors activate astrocytes. These passages support the signaling role, but they describe stressors or pathological conditions rather than specifically acute inflammation, and do not establish the claimed acute role in signaling to other local immune cells. Page numbers are unavailable in our copy. (LLM, conf=0.84)

  Experimental — accuracy not yet measured

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

SPMs do so more readily in males.

“but they actually do so more readily in males [30, 40].”

• cites [30] Bain CC, Hawley CA, Garner H, et al. Long-lived self-renewing bone marrow-derived macrophages displace embryo-derived cells to inhabit adult serous cavities. Nat Commun. 2016;7:ncomms11852. https://doi.org/10.1038/ncomms11852. Published 2016 Jun 13. sourcePartly supported

  The Results section on F4/80loCSF1R+ precursors identifies small peritoneal macrophage–like cells as intermediates in replenishing resident F4/80hi macrophages. The Results section on gradual replenishment reports more than sixfold greater replacement of peritoneal F4/80hi macrophages in male mice. It does not separately establish that SPMs themselves differentiate more readily in males; the measured sex difference is in replacement of the resident population. (LLM, conf=0.82)

  Experimental — accuracy not yet measured
• cites [40] Bain CC, Gibson DA, Steers NJ, et al. Rate of replenishment and microenvironment contribute to the sexually dimorphic phenotype and function of peritoneal macrophages. Sci Immunol. 2020;5(48):eabc4466. https://doi.org/10.1126/sciimmunol.abc4466. sourceSupported

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

Many drugs aiming to cure or mediate disease have been pulled from the market due to unforeseen issues arising in one sex or another.

“Many drugs aiming to cure or mediate disease have been pulled from the market due to unforeseen issues arising in one sex or another [50, 51].”

• cites [50] Soldin OP, Mattison DR. Sex differences in pharmacokinetics and pharmacodynamics. Clin Pharmacokinet. 2009;48(3):143–57. https://doi.org/10.2165/00003088-200948030-00001. sourceSupported
• cites [51] U.S. Government Accountability Office. Drug Safety: Most Drugs Withdrawn in Recent Years Had Greater Health Risks for Women. 2001. GAO-01-286R. Accessed August 22, 2024.Not matched

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

May combine two claims.

Up until approximately the 6 h mark, P522R and WT male pMacs performed very similar amounts of E. coli uptake, but the P522R pMacs were not able to keep up with the WT pMacs thereafter.

“Up until approximately the 6 h mark, the P522R and WT pMacs performed very similar amounts of E. coli uptake, but the P522R pMacs were not able to keep up with the WT pMacs, which seemingly performed better (Fig. 4B).”

May combine two claims.

Vehicle-treated pMacs from WT and P522R males produced very low concentrations of inflammatory cytokines, with no difference between genotypes.

“We found that vehicle treated cells produced very low concentrations of inflammatory cytokines, with no difference between WT and P522R cells, further supporting that our ex vivo cultures are not activated or inflammatory at baseline conditions (Fig. 6A-H).”

Classified as probably not a substantial claim.

The results were quite distinct from the male groups.

“These distinct gene groups were once again analyzed via GO biological process pathway analysis, and the results were, unsurprisingly, quite distinct from the male groups.”

May combine two claims.

In females, these same differences were not found, and the P522R mutation seemingly had little effect on E. coli uptake over time.

“In females, these same differences were not found, and the P522R mutation seemingly had little effect on E. coli uptake over time.”

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

Phagocytosis treatment conditions were performed in triplicate wells and averaged for analysis.

“Treatment conditions were performed in triplicate wells and averaged for analysis.”

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

Multiplexed immunoassay samples were plated in duplicate at a 1:1 dilution with MSD diluent 41.

“Samples were plated in duplicate at a 1:1 dilution with MSD diluent 41 and the rest of the experimental procedure was performed according to the manufacturer’s instructions.”

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

Raw NanoString counts were normalized to the geometric mean of the positive and negative controls.

“Raw counts were normalized to the geometric mean of the positive and negative controls and count expression was calculated via nSolver Advanced Analysis v2.0.134.”

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

RNA quality was assessed using Bioanalyzer 2100.

“Concentration of RNA was analyzed on a spectrophotometer, and RNA quality was assessed using Bioanalyzer 2100 (Agilent, Denmark).”

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

Fluorescence minus one controls (FMOCs) were used to set flow cytometry gates and isotype controls were used to ensure antibody-specific binding.

“When validating flow cytometry panels and antibodies, fluorescence minus one controls (FMOCs) were used to set gates and isotype controls were used to ensure antibody-specific binding.”

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

A minimum of 100,000 events were captured per sample for flow cytometric analysis.

“A minimum of 100,000 events were captured per sample and data were analyzed using FlowJo version 10.6.2 software (BD Biosciences).”

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

A three-day rest period after thioglycolate injection and before cell isolation allows acute inflammation and cell activation induced by the injection to subside.

“However, we do allow a three-day rest period post injection and prior to cell isolation so that acute inflammation and cell activation induced by the injection subside (Fig. 1).”

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

All animal procedures were approved by the University of Florida Institutional Animal Care and Use Committee and were in accordance with the National Institute of Health Guide for the Care and Use of Laboratory Animals.

“All animal procedures were approved by the University of Florida Institutional Animal Care and Use Committee and were in accordance with the National Institute of Health Guide for the Care and Use of Laboratory Animals (NIH Publications No. 80 − 23) revised 1996.”

May combine two claims.

The P522R mutation may confer functional advantages in lysosomal activity in pMacs from females, but not in males.

“These data indicate that the P522R mutation may confer functional advantages in lysosomal activity in pMacs from females, but not in males.”

• AssumptionRests on an assumption: The P522R mutation is associated with protection.

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

These data further support previously published data indicating significant sex-differences in immune cell populations and function.

“and further support previously published data indicating significant sex-differences in immune cell populations and function.”

Classified as probably not a substantial claim.

Fluorescently labeled E. coli bioparticles only fluoresce after being internalized and exposed to the low pH associated with the lysosome, thereby reporting on the extent of bacterial uptake by the cells.

“we utilized fluorescently labeled E. coli bioparticles which only fluoresce after being internalized and exposed to the low pH associated with the lysosome, thereby reporting on the extent of bacterial uptake by the cells (Supplemental Fig. 4).”

May combine two claims.

The P522R mutation has sex-dependent effects on phagocytosis and lysosomal function.

“We have already demonstrated that the P522R mutation has sex-dependent effects on phagocytosis and lysosomal function”

May combine two claims. The quote only partly states this claim.

pMacs from females seemed to be more affected by the presence of the mutation and produced significantly more inflammatory cytokines over time than pMacs from males.

“the pMacs from females seemed to be more affected by the presence of the mutation and produced significantly more inflammatory cytokines over time.”

May combine two claims.

The P522R mutation alters phagocytosis and lysosomal activity in male pMacs, but these alterations may not be beneficial to pMac function.

“These data indicate that the P522R mutation does indeed alter phagocytosis and lysosomal activity in males, but these alterations may not be beneficial to pMac function.”

• AssumptionRests on an assumption: The P522R mutation is associated with protection.

May combine two claims.

In males, the P522R mutation does not affect the makeup of peritoneal macrophage sub-populations, but does increase the amount of resident LPMs displaying antigens.

“These data indicate that in males the P522R mutation does not affect the makeup of peritoneal macrophage sub-populations, but does increase the amount of resident LPMs displaying antigens.”

May combine two claims.

The P522R mutation's effects may be activation-dependent and not as prevalent under baseline conditions.

“supporting the idea that the P522R mutation’s effects may be activation-dependent, and not as prevalent under baseline conditions.”

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

Gene expression was considered significant if p < 0.05 after Benjamini-Hochberg false discovery rate adjustment and if the fold change was greater than 1.5.

“Gene expression was considered significant if p < 0.05 after adjustment using the Benjamini-Hochberg method for false discovery rate, and if the fold change was greater than 1.5.”

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

AD progression has been correlated with infection.

“AD progression has been correlated with infection, emphasizing the importance of the pMacs ability to uptake and degrade bacterial particles [42].”

• cites [42] Maheshwari P, Eslick GD. Bacterial infection and alzheimer’s disease: a meta-analysis. JAD. 2014;43(3):957–66. https://doi.org/10.3233/JAD-140621. sourceNot checked — no full text of the source

Classified as probably not a substantial claim.

Intraperitoneal injection of 3% thioglycolate prior to isolation allows harvesting both large peritoneal macrophages (LPMs) and small peritoneal macrophages (SPMs), not just resident LPMs.

“This step is crucial prior to isolation, as it allows us to harvest both LPMs and SPMs, not just the resident LPMs.”

• AssumptionRests on an assumption: Peritoneal macrophages are a heterogeneous population, with small peritoneal macrophages (SPMs) arising from blood monocytes and large peritoneal macrophages (LPMs) resident to the peritoneal cavity.

Classified as probably not a substantial claim.

DQ-BSA is a substrate for proteases that only fluoresces after it has been cleaved within the lysosome.

“To do so, we treated the cells with DQ-BSA, a substrate for proteases that only fluoresces after it has been cleaved within the lysosome, and quantified via flow cytometry.”

May combine two claims.

The effects of the P522R mutation on macrophage sub-populations and antigen presentation are largely sex-specific, and bi-directional in the case of antigen presentation.

“However, these effects are largely sex-specific, and even bi-directional in the case of antigen presentation.”

• Also stated in: § The P522R mutation does not alter phagocytic capacity in pMacs from females, but increases lysosomal protease activity · plain

  “Similar to what we found in our assessment of pMac populations, the P522R mutation had different effects in pMacs from females compared to pMacs from males.”

Classified as probably not a substantial claim.

The adherence step of resting peritoneal cells for two hours and then rinsing allows only adherent peritoneal macrophages (pMacs) to remain, washing away other immune cell types.

“Additionally, after plating the cells collected from the peritoneum, we leave the cells to rest for two hours and then rinse with sterile DPBS and replace the media, as this allows only the adherent cells (pMacs) to remain and all other immune cell types to be washed away (Supplemental Fig. 1B).”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

Our study only looked at acute cytokine secretion, which is likely to have been an adaptive and beneficial response.

“Although it could be assumed that these increases in inflammatory cytokines could be negative, our study only looked at acute cytokine secretion, which is likely to have been an adaptive and beneficial response.”

May combine two claims.

Herein, we show that the P522R mutation does indeed confer functional alterations in the periphery, but these changes seem to vary by sex.

“Herein, we show that the P522R mutation does indeed confer functional alterations in the periphery, but these changes seem to vary by sex.”

May combine two claims.

In pMacs from males, the P522R mutation decreases phagocytosis and lysosomal activity, and does not exert as strong of an effect on inflammatory cytokine secretion as is seen in females.

“This lines up with the functional data that revealed that in pMacs from males, the P522R mutation decreases phagocytosis and lysosomal activity, and does not exert as strong of an effect on inflammatory cytokine secretion as is seen in females.”

May combine two claims.

Our data indicated that this effect is also present in pMacs, but to different extents in males and females.

“Our data indicated that this effect is also present in pMacs, but to different extents in males and females.”

May combine two claims.

The P522R mutation alters pMac sub-populations in females but not males.

“These data indicate that the mutation alters pMac sub-populations in females but not males”

May combine two claims.

Taken together, these results suggested the potential of the P522R mutation to be positive in females, but potentially negative in males via the reduction in bacterial uptake and degradation.

“Taken together, these results suggested the potential of the P522R mutation to be positive in females, but potentially negative in males via the reduction in bacterial uptake and degradation.”

May combine two claims.

Herein we provide the first evidence that the P522R mutation also modulates peripheral tissue-resident macrophage functions, and that these effects are highly sex-dependent.

“Herein we provide the first evidence that the P522R mutation also modulates peripheral tissue-resident macrophage functions, and that these effects are highly sex-dependent.”

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

Some functional changes could be due to the macrophages' direct interaction with/response to other mutated immune cells which might leave lasting impacts on macrophage function.

“some of these functional changes could be due to the macrophages’ direct interaction with/response to other mutated immune cells which might leave lasting impacts on macrophage function.”

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

These responses and functional differences may not solely be due to intrinsic changes in macrophages due to the P522R mutation.

“It should be noted however, that these responses and functional differences may not solely be due to intrinsic changes in macrophages due to the P522R mutation.”

May combine two claims.

It appears based on our transcriptomic data that the P522R mutation activates different intracellular signaling pathways and concurrent gene expression in response to LPS leading to the different outcomes in response to activation seen between males and females.

“It appears based on our transcriptomic data that the P522R mutation activates different intracellular signaling pathways and concurrent gene expression in response to LPS leading to the different outcomes in response to activation seen between males and females.”

May combine two claims.

It further supports the importance of including sex as a biological variable in studies, showing that not only can the magnitude of response to protective genetic mutations be different between sexes, but also the directionality of response can vary by sex and will have implications for future therapeutic interventions.

“It further supports the importance of including sex as a biological variable in studies as well, showing that not only can the magnitude of response to protective genetic mutations be different between sexes, but also the directionality of response can vary by sex and will have implications for future therapeutic interventions.”

May combine two claims.

Peripheral immune cells, particularly peritoneal macrophages, are affected by the presence of this mutation, and show transcriptional, lysosomal, phagocytic, and inflammatory alterations due to its presence, particularly after an inflammatory challenge.

“However, we can say with certainty that peripheral immune cells, particularly peritoneal macrophages, are affected by the presence of this mutation, and show transcriptional, lysosomal, phagocytic, and inflammatory alterations due to its presence, particularly after an inflammatory challenge.”