Deletion of SPI1 in microglia exacerbates amyloid pathology by impairing microglial response in Alzheimer’s disease models

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

Microglia play crucial roles in maintaining homeostasis and immune defense in the central nervous system.

“Microglia, professional phagocytes, play crucial roles in maintaining homeostasis and providing immune defense in the central nervous system (CNS)6”

• cites [6] Norris, 2019, Immune cells and CNS physiology: Microglia and beyond, J. Exp. Med. sourceSupported

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

Sample size was based on power calculations from prior APPPS1-21 data, targeting at least 11 mice per genotype.

“The sample size for our study was determined based on statistical power calculations derived from our prior data using the APPPS1–21 mouse model11. Using a power of 0.8, α = 0.05, an effect size of 40% for insoluble Aβ42 levels, and a standard deviation determined from previous studies, we aimed to generate at least 11 mice per genotype.”

• cites [11] Kim, 2024, Effects of SPI1-mediated transcriptome remodeling on Alzheimer’s disease-related phenotypes in mouse models of Aβ amyloidosis, Nat. Commun. sourceSupported

May combine two claims.

The APPPS1-21 model begins Aβ accumulation in the neocortex at about 6 to 8 weeks and shows robust Aβ accumulation and plaque deposition at 4 months.

“The APPPS1–21 mouse model used in our study starts to accumulate Aβ in the neocortex at approximately 6 to 8 weeks of age and exhibits robust Aβ accumulation and plaque deposition at 4 months of age13.”

• cites [13] Radde, 2006, Abeta42-driven cerebral amyloidosis in transgenic mice reveals early and robust pathology, EMBO Rep. sourceSupported

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

Galectin-3 is a key neuroinflammation protein and is strongly upregulated in neurodegenerative conditions.

“Galectin-3 (Gal-3) is a key protein involved in neuroinflammation and is strongly upregulated in neurodegenerative conditions16.”

• cites [16] Heneka, 2015, Neuroinflammation in Alzheimer's disease, Lancet Neurol. sourceCould not verify

  The Microglia and Summary and outlook sections discuss neuroinflammation in neurodegenerative disease, but do not identify galectin-3 as a key protein or report that it is strongly upregulated. Searches for galectin-3, Gal-3, galectin, and LGALS3 found no passage addressing those claims; no page numbers were available in our copy. (LLM, conf=0.75)

  Experimental — accuracy not yet measured

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

Zymosan particles are commonly used to assess general phagocytosis.

“zymosan particles, which are commonly used to assess general phagocytosis25,26”

• cites [25] Wang, 2022, TREM2 drives microglia response to amyloid-β via SYK-dependent and -independent pathways, Cell sourceNot checked — no full text of the source
• cites [26] Pimenova, 2021, Alzheimer's-associated PU.1 expression levels regulate microglial inflammatory response, Neurobiol. Dis. sourceSupported

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

Dystrophic neurites are abnormal neurites around amyloid plaques with swollen, bulbous formations and degenerating axons and dendrites.

“These are abnormal neurites surrounding amyloid plaques characterized by swollen, bulbous formations and the presence of degenerating axons and dendrites27.”

• cites [27] Tate, 2024, Deletion of miR-33, a regulator of the ABCA1–APOE pathway, ameliorates neuropathological phenotypes in APP/PS1 mice, Alzheimers Dement. sourceCould not verify

  The Results section describes amyloid plaque deposition in APP/PS1 mice, but does not describe dystrophic neurites. Searches for neurites, swollen or bulbous formations, and degenerating axons or dendrites found no passage defining them or linking them to plaques; page numbers were unavailable. (LLM, conf=0.70)

  Experimental — accuracy not yet measured

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

Abnormal activation of microglia and astrocytes occurs in Alzheimer's disease patients and APPPS1-21 transgenic model mice.

“Abnormal activation of microglia and astrocytes is observed in the brains of AD patients15 and APPPS1–21 transgenic model mice13.”

• cites [15] Cole, 2007, The Alzheimer's disease β-secretase enzyme, BACE1, Mol. Neurodegener. sourcePartly supported

  The BACE1 expression section (page unavailable) describes astrocyte activation as a feature observed in AD and refers to reactive astrocytes in human AD brain. It does not establish abnormal microglial activation in AD patients. The APPPS1–21 mouse claim has a separate citation and is not attributed to this source. (LLM, conf=0.82)

  Experimental — accuracy not yet measured
• cites [13] Radde, 2006, Abeta42-driven cerebral amyloidosis in transgenic mice reveals early and robust pathology, EMBO Rep. sourceSupported

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

A previous report found no sex-dependent differences in Aβ accumulation in the APPPS1-21 mouse model.

“although a previous report demonstrated no sex-dependent differences in Aβ accumulation in this APPPS1–21 mouse model13”

• cites [13] Radde, 2006, Abeta42-driven cerebral amyloidosis in transgenic mice reveals early and robust pathology, EMBO Rep. sourcePartly supported

  The Cerebral amyloidosis section reports that male and female APPPS1-21 mice did not differ statistically in Aβ levels or amyloid load at 1–2 months of age. The sex comparison was limited to those early ages, so it does not establish an absence of sex-dependent differences in Aβ accumulation generally. (LLM, conf=0.83)

  Experimental — accuracy not yet measured

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

In Alzheimer's disease patients and Aβ amyloidosis model mice, Gal-3 is elevated in microglia around Aβ plaques and induces neuroinflammation and neurodegeneration.

“In both AD patients and Aβ amyloidosis model mice, Gal-3 is significantly elevated in microglia clustered around Aβ plaques, where it induces neuroinflammation and neurodegeneration17,18.”

• cites [17] García-Revilla, 2022, Galectin-3, a rising star in modulating microglia activation under conditions of neurodegeneration, Cell Death Dis. sourcePartly supported

  The Alzheimer’s disease section (page unavailable) reports that Gal-3 is highly upregulated in AD patients and 5xFAD mice, is associated with Aβ plaques, and that deleting it in mice attenuates microglial immune responses and reduces pathology. But the Microglia diversity and Gal-3 section (page unavailable) calls the idea that Gal-3 makes microglia neurotoxic speculative; the copy does not establish that plaque-associated Gal-3 induces neurodegeneration in patients and mice as the sentence states. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites [18] Boza-Serrano, 2022, Galectin-3 is elevated in CSF and is associated with Aβ deposits and tau aggregates in brain tissue in Alzheimer’s disease, Acta Neuropathol. sourcePartly supported

  The Introduction reports elevated Gal-3 in plaque-associated microglia in AD patients, and the Abstract describes its expression around plaques in both human and mouse brain. The Discussion links Gal-3 to a detrimental inflammatory response, but its human findings associate Gal-3 with markers of neuronal degeneration; they do not establish that Gal-3 induces neurodegeneration in patients or model mice. Page numbers were not available in our copy. (LLM, conf=0.85)

  Experimental — accuracy not yet measured

Classified as probably not a substantial claim.

Microglial Fcgr1 is involved in Aβ clearance via Fc-receptor-Syk-mediated phagocytosis.

“Like Syk, microglial Fcgr1 is involved Aβ clearance via Fc-receptor-Syk-mediated phagocytosis53.”

• cites [53] Islam, 2022, Gender differences in Alzheimer's may be associated with TLR4-LYN expression in damage associated microglia and neuronal phagocytosis, J. Cell. Physiol. sourceCould not verify

  The Discussion addresses Aβ clearance and TLR4–LYN signaling, while the ‘Microglial phagocytosis of neurons in AD mice’ section examines neuronal material, not Aβ clearance. Neither passage identifies Fcgr1 or an Fc-receptor–Syk phagocytosis pathway; searches for those terms found no supporting passage in our copy. Page numbers were not available. (LLM, conf=0.75)

  Experimental — accuracy not yet measured

May combine two claims.

Microglia facilitate Aβ clearance through phagocytosis and can also exacerbate neurodegeneration by driving persistent neuroinflammation.

“For example, they facilitate the clearance of Aβ through phagocytosis42, yet they can also exacerbate neurodegeneration by driving persistent neuroinflammation43.”

• cites [42] Lee, 2010, The role of microglia in amyloid clearance from the AD brain, J. Neural Transm. (Vienna) sourceSupported
• cites [43] Sarlus, 2017, Microglia in Alzheimer's disease, J. Clin. Investig. sourceSupported

May combine two claims.

Spi1 overexpression enhances microglial phagocytosis, whereas Spi1 knockdown reduces this function in the same cell line.

“Conversely, Spi1 overexpression enhances microglial phagocytosis, whereas its knockdown reduced this function in the same cell line7,25.”

• cites [7] Huang, 2017, A common haplotype lowers PU.1 expression in myeloid cells and delays onset of Alzheimer's disease, Nat. Neurosci. sourceSupported
• cites [25] Wang, 2022, TREM2 drives microglia response to amyloid-β via SYK-dependent and -independent pathways, Cell sourceNot checked — no full text of the source

May combine two claims.

Partial reduction of human APOE level substantially reduced amyloid deposition and neuroinflammation, independent of APOE isoform, implicating overall APOE protein abundance as a key driver of AD pathogenesis.

“Partial reduction of human APOE level substantially reduced amyloid deposition and neuroinflammation, independent of APOE isoform, implicating overall APOE protein abundance itself as a key driver of AD pathogenesis56,57.”

• cites [56] Bien-Ly, 2012, Reducing Human Apolipoprotein E Levels Attenuates Age-Dependent Aβ Accumulation in Mutant Human Amyloid Precursor Protein Transgenic Mice, J. Neurosci. sourcePartly supported

  The Results section, “Halving the levels of apoE significantly attenuates Aβ deposition in aged mice,” reports fewer fibrillar plaques with one rather than two copies of either human APOE3 or APOE4. The Discussion also says the reduction in Aβ accumulation occurred regardless of isoform, while noting that the effects differed by isoform and age. Our copy does not report that reducing APOE lowered neuroinflammation or establish protein abundance as a driver of AD pathogenesis beyond the measured amyloid outcomes in mice. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [57] Chemparathy, 2024, APOE loss-of-function variants: Compatible with longevity and associated with resistance to Alzheimer’s disease pathology, Neuron sourceNot checked — no full text of the source

Classified as probably not a substantial claim.

A human genetic study reported that lower SPI1 expression is associated with delayed onset of AD.

“Interestingly, our findings appear to contradict a human genetic study that reported the association of lower SPI1 expression with the delayed onset of AD7.”

• cites [7] Huang, 2017, A common haplotype lowers PU.1 expression in myeloid cells and delays onset of Alzheimer's disease, Nat. Neurosci. sourceSupported

May combine two claims.

In a 1-year-old male amyloid mouse model, the compound alleviated neuropathological phenotypes including neuroinflammation.

“When tested in a 1-year-old male amyloid mouse models, this compound alleviated neuropathological phenotypes, including neuroinflammation51, opening exciting possibilities for future treatment strategies.”

• cites [51] Ennerfelt, 2022, SYK coordinates neuroprotective microglial responses in neurodegenerative disease, Cell sourcePartly supported

  The Results section, “Exogenous activation of the CLEC7A-SYK signaling pathway promotes improved clearance of Aβ” (page unavailable), reports that pustulan reduced hippocampal Aβ load in 5xFAD mice compared with vehicle. The cited passages do not establish that the treated mice were 1-year-old males or that the compound alleviated neuroinflammation; the reported treatment outcome is Aβ clearance. (LLM, conf=0.85)

  Experimental — accuracy not yet measured

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

A recent study by Wu et al. (2025) reported that microglial PU.1 is essential for microglial maintenance in adult mice, with reduced microglial numbers 1 week after tamoxifen in Spi1Fl/Fl;Cx3cr1CreER mice compared to Spi1Fl/+;Cx3cr1CreER mice.

“Nevertheless, a recent study by Wu et al. (2025) reported that microglial PU.1 is essential for microglial maintenance in adult mice44, demonstrating a reduction in microglial numbers 1 week after tamoxifen injection in Spi1Fl/Fl;Cx3cr1CreER mice compared to Spi1Fl/+;Cx3cr1CreER mice.”

• cites [44] Wu, 2025, Pu.1/Spi1 dosage controls the turnover and maintenance of microglia in zebrafish and mammals, eLife sourceSupported

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

Lowering APOE levels may confer protection against AD.

“Previous studies suggest that lowering APOE levels may confer protection against AD56–59.”

• cites [56] Bien-Ly, 2012, Reducing Human Apolipoprotein E Levels Attenuates Age-Dependent Aβ Accumulation in Mutant Human Amyloid Precursor Protein Transgenic Mice, J. Neurosci. sourceSupported
• cites [57] Chemparathy, 2024, APOE loss-of-function variants: Compatible with longevity and associated with resistance to Alzheimer’s disease pathology, Neuron sourceNot checked — no full text of the source
• cites [58] Tate, 2024, APOE loss of function: A genetic shield against Alzheimer’s disease, Neuron sourceNot checked — no full text of the source
• cites [59] Lopes, 2022, Genetic analysis of the human microglial transcriptome across brain regions, aging and disease pathologies, Nat. Genet. sourceCould not verify

  The Results section links altered microglial gene expression to Alzheimer’s disease risk, but its specific example concerns USP6NL, not APOE. Searches for APOE and for lowered APOE expression found no passage in our copy saying that lowering APOE levels may protect against Alzheimer’s disease. (LLM, conf=0.76)

  Experimental — accuracy not yet measured

May combine two claims.

Cx3cr1CreER mice can exhibit Cre recombination even without tamoxifen injection, which could confound experimental results.

“However, it has been reported that Cx3cr1CreER mice can exhibit Cre recombination even without tamoxifen injection, which could confound experimental results48,49.”

• cites [48] Stifter, 2020, STOP floxing around: Specificity and leakiness of inducible Cre/loxP systems, Eur. J. Immunol. sourceSupported
• cites [49] Sahasrabuddhe, 2022, Cx3Cr1-Cre induction leads to microglial activation and IFN-1 signaling caused by DNA damage in early postnatal brain, Cell Rep. sourceNot checked — no full text of the source

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

Microglial Syk is essential for Aβ clearance, and its deficiency exacerbates Aβ pathology in a mouse model.

“Intriguingly, recent studies revealed that microglial Syk is essential for Aβ clearance, with its deficiency exacerbating Aβ pathology in a mouse model24,52.”

• cites [24] Condello, 2015, Microglia constitute a barrier that prevents neurotoxic protofibrillar Aβ42 hotspots around plaques, Nat. Commun. sourceCould not verify

  The Introduction discusses a possible role for microglia in Aβ clearance, and the Results examine CX3CR1 manipulation and plaque neurotoxicity. Searches for Syk and Syk deficiency found no passage in our copy addressing whether microglial Syk is essential for clearance or whether its deficiency exacerbates Aβ pathology. (LLM, conf=0.75)

  Experimental — accuracy not yet measured
• cites [52] Illouz, 2021, Maternal antibodies facilitate Amyloid-β clearance by activating Fc-receptor-Syk-mediated phagocytosis, Commun. Biol. sourcePartly supported

  The Results section ('MAbs facilitate Aβ clearance by microglial cells in a Syk-dependent manner'; page unavailable) reports that Syk inhibition reduced Aβ phagocytosis in cultured microglia, supporting a role for Syk in clearance. It does not show that microglial Syk deficiency exacerbated Aβ pathology in a mouse model; the mouse findings concern maternal vaccination and Syk activation, not Syk deficiency. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

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

The level of APOE plays critical roles in AD-associated phenotypes beyond APOE isoform status.

“Beyond APOE isoform status, the level of APOE also plays critical roles in AD-associated phenotypes55.”

• cites [55] Kim, 2011, Haploinsufficiency of human APOE reduces amyloid deposition in a mouse model of amyloid-beta amyloidosis, J. Neurosci. sourceSupported

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

A compound that recruits transcriptional co-repressor complexes to SPI1 binding motifs indirectly inhibits PU.1 function without directly binding PU.1.

“Although this compound did not directly bind to the PU.1 protein, it indirectly inhibited PU.1 function through these co-repressor complexes51.”

• cites [51] Ennerfelt, 2022, SYK coordinates neuroprotective microglial responses in neurodegenerative disease, Cell sourceCould not verify

  The Results section on Aβ-induced microglial activation discusses how SYK deletion alters microglial gene expression, not a compound acting on PU.1. Searches for PU.1, SPI1, co-repressor complexes, and indirect inhibition found no passage in our copy addressing the claimed mechanism. (LLM, conf=0.77)

  Experimental — accuracy not yet measured

May combine two claims.

Seven genes (Syk, Lyn, Stat1, Entpd1, Rgs10, Fcgr1, and Fcgr3) are directly targeted by Spi1 and may be involved in phagocytosis.

“Based on the “Immune response_Phagocytosis” components and the Spi1 chromatin immunoprecipitation sequencing (ChIP-Seq) data38,39, we selected seven genes (Syk, Lyn, Stat1, Entpd1, Rgs10, Fcgr1, and Fcgr3) that are directly targeted by Spi1 and may be involved in phagocytosis.”

• cites [38] Crotti, 2014, Mutant Huntingtin promotes autonomous microglia activation via myeloid lineage-determining factors, Nat. Neurosci. sourcePartly supported

  The Results section on mHTT-promoted PU.1–C/EBP gene expression reports PU.1 ChIP-seq data in microglia, supporting the citation as a source of Spi1/PU.1 binding data (page unavailable). Our copy does not identify the seven named genes as direct targets or link them to phagocytosis; searches for the gene list, Fcgr3, and phagocytosis did not locate that evidence. (LLM, conf=0.82)

  Experimental — accuracy not yet measured
• cites [39] Satoh, 2014, A Comprehensive Profile of ChIP-Seq-Based PU.1/Spi1 Target Genes in Microglia, Gene Regul. Syst. Biol. sourcePartly supported

  The Results section on target-gene identification names Syk as a ChIP-Seq-based Spi1 target, and the molecular-networks Results section links the broader target set to phagocytosis pathways (page numbers unavailable). Our copy does not identify Lyn, Stat1, Entpd1, Rgs10, Fcgr1, or Fcgr3 as Spi1 targets or link each of the seven genes to phagocytosis. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

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

Impaired Aβ clearance by microglia may be associated with Lyn.

“In addition, a recent study suggested that impaired Aβ clearance by microglia may be associated with Lyn54.”

• cites [54] Kang, 2018, Microglial translational profiling reveals a convergent APOE pathway from aging, amyloid, and tau, J. Exp. Med. sourceCould not verify

  The Results and discussion passage links aging, amyloidosis, and tauopathy to a microglial APOE response and possible dysfunction, but does not link Lyn to impaired Aβ clearance. Searches of our full-text copy for Lyn and Aβ clearance found no passage addressing that association. (LLM, conf=0.75)

  Experimental — accuracy not yet measured

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

The rs1057233 SNP in SPI1 is a protective allele (OR=0.93, 95% CI=0.91-0.97) associated with lower SPI1 mRNA levels in peripheral immune cells.

“This study identified a specific variant within the SPI1 gene (rs1057233 SNP) as a protective allele (odds ratio [OR] = 0.93, 95% confidence interval [CI] = 0.91–0.97) and found it is associated with lower SPI1 mRNA levels in peripheral immune cells (monocytes and macrophages)7.”

• cites [7] Huang, 2017, A common haplotype lowers PU.1 expression in myeloid cells and delays onset of Alzheimer's disease, Nat. Neurosci. sourcePartly supported

  The Results section (Cis-eQTL associations and colocalization analysis; page unavailable) identifies the protective rs1057233G allele and reports its association with lower SPI1 expression in monocytes and macrophages. The passages retrieved for the stated odds ratio and confidence interval do not establish OR = 0.93 or 95% CI = 0.91–0.97, so those figures are not verified by our copy. (LLM, conf=0.84)

  Experimental — accuracy not yet measured

May combine two claims.

Microglial SPI1 deficiency did not change microglial number but reduced microglial processes.

“Taken together, these findings indicate that although the deficiency of microglial SPI1 did not alter the number of microglia, it led to a reduction in microglial processes.”

May combine two claims.

GFAP+ cell area and GFAP+ cell number per area were increased by 2.39-fold and 1.57-fold in the cortex of Spi1ΔMG;APPPS1-21 mice.

“the GFAP+ cell area and the number of GFAP+ cells normalized by the area were significantly increased by 2.39-fold (Figure 4G) and 1.57-fold (Figure 4H), respectively, in the cortical area of Spi1ΔMG;APPPS1–21 mice compared to Spi1wt;APPPS1–21 mice.”

May combine two claims.

SPI1 is functionally or physically associated with Syk and Lyn in the Immune response_Phagocytosis network.

“This analysis further supported that SPI1 is functionally or physically associated with Syk and Lyn in the “Immune response_Phagocytosis” network.”

May combine two claims.

Microglial Spi1 deletion increases the extent of dystrophic neurites and the number of neuritic plaques.

“These results demonstrate that microglial Spi1 deletion significantly increases the extent of dystrophic neurites and the number of”

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

Insoluble Aβ40 and Aβ42 levels were significantly correlated in cortical and hippocampal tissues and in PBS and RIPA fractions of cortical tissue.

“there was a significant correlation between insoluble Aβ40 and Aβ42 levels in both in cortical and hippocampal tissues (Figures S2E and S2F, respectively), as well as in the PBS and RIPA fractions of cortical tissue (Figures S2G and S2E, respectively) from these mice.”

May combine two claims.

The number of neuritic plaques (LAMP1+82E1+) was increased by 1.45-fold in cortex and 2.05-fold in hippocampus in Spi1ΔMG;APPPS1-21 mice.

“The number of neuritic plaques (LAMP1+82E1+) was also significantly increased by 1.45- and 2.05-fold in the cortical and hippocampal areas, respectively, in the Spi1ΔMG;APPPS1–21 mice compared to Spi1wt;APPPS1–21 mice (Figures 6D and 6E).”

May combine two claims.

Microglial Spi1 deletion increased fibrillar plaque load by 1.69-fold in cortex and 2.08-fold in hippocampus.

“We observed a significant increase in the fibrillar plaque load by 1.69- and 2.08-fold in the cortical and hippocampal areas, respectively, in Spi1ΔMG;APPPS1–21 mice compared to Spi1wt;APPPS1–21 mice (Figures 3G and 3H).”

May combine two claims.

Microglial Spi1 deletion increased Aβ plaque load by 1.52-fold in cortex and 1.65-fold in hippocampus.

“microglial Spi1 deletion significantly increased the Aβ plaque load by 1.52- and 1.65-fold in the cortical and hippocampal areas, respectively (Figures 3B and 3C).”

May combine two claims.

IBA1+ cell area and IBA1+ cell number per area were increased by 1.51-fold and 1.36-fold in the cortex of Spi1ΔMG;APPPS1-21 mice.

“The area covered by IBA1+ cell and the number of IBA1+ cells per area were significantly increased by 1.51-fold and 1.36-fold, respectively, in the cortical area of Spi1ΔMG;APPPS1–21 mice compared to Spi1wt;APPPS1–21 mice (Figures 4B and 4C).”

May combine two claims.

Microglial Spi1 deletion increased LAMP1+ cluster load by 1.72-fold in cortex and 2.06-fold in hippocampus.

“Microglial Spi1 deletion dramatically increased the LAMP1+ cluster load by 1.72- and 2.06-fold in the cortical and hippocampal areas, respectively, compared to that in Spi1wt;APPPS1–21 mice (Figures 6B and 6C).”

The quote only partly states this claim.

No significant differences in microglial numbers or density were observed between Spi1wt and Spi1ΔMG mice at 1 and 2 weeks after final tamoxifen injection.

“No significant differences were observed between genotypes, consistent with our finding at 4 weeks post-injection (Figures 1E–1I).”

May combine two claims.

In APPPS1-21 mice, microglial Spi1 deletion significantly increases microgliosis, astrogliosis, and neuroinflammatory marker gene expression.

“In APPPS1–21 mice, microglial Spi1 deletion led to a significant increase in microgliosis and astrogliosis (Figure 4) as well as elevated expression of neuroinflammatory maker genes (Figure S3).”

May combine two claims.

In primary microglia, overexpression of Syk and Fcgr1 significantly restores Aβ uptake impaired by Spi1 knockdown without affecting cell viability.

“Importantly, consistent with our findings in BV-2 cells, the overexpression of Syk and Fcgr1 significantly restored the Aβ uptake impaired by Spi1 knockdown in primary microglia (Figure 7I), without affecting cell viability (Figure S7C).”

May combine two claims.

Spi1 deletion in microglia worsens Aβ accumulation by disrupting SPI target genes including Syk, Lyn, and Fcgr1, but not Stat1 and Entpd1.

“Our findings suggest that Spi1 deletion in microglia exacerbates Aβ accumulation by disrupting the regulatory functions of SPI target genes, including Syk, Lyn, and Fcgr1, but not Stat1 and Entpd1.”

May combine two claims.

The findings suggest a general decrease in microglial surveillance activity or an alteration in microglial function.

“These findings suggest a general decrease in microglial surveillance activity or a potential alteration in microglial function.”

May combine two claims.

This impairment may increase activation of microglia and astrocytes, triggering neuroinflammation in an Aβ amyloidosis mouse model.

“This impairment consequently may lead to increased activation of both microglia and astrocytes, triggering neuroinflammation in a mouse model of Aβ amyloidosis.”

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

Separate analyses using up- or down-regulated DEPs supported the pathway and network findings.

“These findings were also supported by separate analyses with up- or down-regulated DEPs (Figure S6).”

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

PU.1 is essential for microglial development at the embryonic precursor stage, and early Spi1 deletion interferes with microglial maturation.

“Since the transcription factor PU.1 is essential for the development of microglia at the embryonic microglial precursor stage, deletion of the Spi1 gene at this early stage interferes with the maturation of microglia8.”

• cites [8] Kierdorf, 2013, Microglia emerge from erythromyeloid precursors via Pu.1- and Irf8-dependent pathways, Nat. Neurosci. sourceNot checked — no full text of the source

May combine two claims.

Spi1 deletion in microglia reduces microglial processes in an Aβ amyloid mouse model, impairing microglial detection of and response to brain microenvironment changes or damage.

“Taken together, our results indicate that deletion of Spi1 in microglia reduces microglial processes in an Aβ amyloid mouse model, impairing the ability of microglia to detect and respond to changes or damage in the brain microenvironment.”

May combine two claims.

CD11b+MeX04+CD45high microglia and their population abundance were barely detectable in a B6 mouse, confirming assay specificity.

“As expected, the accumulation of CD11b+MeX04+CD45high microglia cells (Figure 5D) and their population abundance (Figure S4D) were barely detectable in a B6 mouse. This confirms the specificity of the assay for the target population.”

May combine two claims.

The APP processing pathway term includes Aβ40 and Aβ42 and supports the observation that Spi1 knockout in microglia increases Aβ accumulation and amyloid plaque deposition.

“The pathway term “Protein folding and maturation_Amyloid precursor protein processing”, which includes Aβ40, Aβ42 as the component, further supports our observation that Spi1 knockout in microglia significantly increases Aβ accumulation and amyloid plaque deposition (Figures 2 and 3).”

May combine two claims.

Spi1 deletion impairs general microglial phagocytic function without affecting cell viability, indicating a crucial role for SPI1 in microglial phagocytosis including Aβ.

“These findings suggest that Spi1 deletion impairs general microglial phagocytic function without affecting cell viability, highlighting the crucial role of SPI1 in regulating microglial phagocytosis, including that of Aβ.”

May combine two claims.

Microglial Spi1 knockout exacerbates gliosis likely due to reduced phagocytic clearance of Aβ, which increases Aβ accumulation and amyloid plaque deposition.

“Our in vivo study demonstrates that microglial Spi1 knockout exacerbates gliosis (Figure 4), likely due to the reduced phagocytic clearance of Aβ (Figure 5), which in turn exacerbates Aβ accumulation (Figure 2) and amyloid plaque deposition (Figure 3).”

May combine two claims.

Conditional Spi1 knockout in microglia exacerbates multiple AD-related pathologies in APPPS1-21 mice, including increased soluble and insoluble Aβ, more amyloid plaques, increased neuroinflammation, and higher dystrophic neurites.

“Our study demonstrates that conditional Spi1 knockout in microglia significantly exacerbates multiple aspects of AD, such as increased soluble and insoluble Aβ levels (Figure 2), more amyloid plaque deposition (Figure 3), increased neuroinflammation including both microgliosis and astrogliosis (Figure 4 and Figure S3), and higher levels of dystrophic neurites (Figure 6) in APPPS1–21 mice.”

• Also stated in: § DISCUSSION · boosted

  “Our data demonstrate that the knockout of Spi1 in microglia exacerbates multiple AD pathologies in a mouse model of Aβ amyloidosis (Figures 2, 3, 4, and 6).”

May combine two claims.

SPI1 has a critical regulatory role in microglial function and AD pathogenesis.

“The dramatic effects on AD pathology observed with such a modest decrease in SPI1 levels, including increased amyloid deposition (Figures 2 and 3), higher gliosis (Figure 4), and impaired microglial phagocytosis (Figures 5D,5E,5G,5H), actually underscore the critical regulatory role of SPI1 in microglial function and AD pathogenesis.”

May combine two claims.

Spi1 knockdown attenuates microglial inflammatory response in BV-2 cells, while Spi1 overexpression exacerbates this phenotype.

“For example, Spi1 knockdown attenuates the microglial inflammatory response in BV-2 cells, while its overexpression exacerbates this phenotype25.”

• cites [25] Wang, 2022, TREM2 drives microglia response to amyloid-β via SYK-dependent and -independent pathways, Cell sourceNot checked — no full text of the source

May combine two claims.

APOE loss-of-function variants in cognitively normal elderly individuals are compatible with healthy aging and confer resistance to AD pathology, including absence of neuritic plaques and normal CSF Aβ profiles.

“Chemparathy et al. (2024) identified APOE loss-of-function variants in cognitively normal elderly individuals, demonstrating that these mutations are compatible with healthy aging and confer resistance to AD pathology, including the absence of neuritic plaques and normal CSF Aβ profiles58.”

• cites [58] Tate, 2024, APOE loss of function: A genetic shield against Alzheimer’s disease, Neuron sourceNot checked — no full text of the source

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

The conflicting outcome may stem from in vitro models not fully replicating the complexity of the systemic environment.

“This apparently conflicting outcome may stem from a limitation of in vitro model, as cell line experiments cannot fully replicate the complexity of the systemic environment.”

• AssumptionRests on an assumption: Cell line experiments cannot fully replicate the complexity of the systemic environment.

May combine two claims.

SPI1 has a dual role in Aβ clearance and regulation of inflammatory responses, both essential for effective AD treatment.

“Taken together, these findings underscore the dual role of SPI1 in Aβ clearance and the regulation of inflammatory responses, both of which are essential for effective AD treatment.”

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

Spi1 knockdown attenuates inflammatory response to LPS and Aβ42 in the BV-2 cell line.

“This finding appears to contradict a previous in vitro study, which reported that knockdown of Spi1 attenuates the inflammatory response to LPS and Aβ42 in the BV-2 cell line25.”

• cites [25] Wang, 2022, TREM2 drives microglia response to amyloid-β via SYK-dependent and -independent pathways, Cell sourceNot checked — no full text of the source

Classified as probably not a substantial claim.

Aβ uptake measurements were normalized to cell viability because Aβ uptake is strongly influenced by cell density.

“Since Aβ uptake is strongly influenced by the cell density, we examined the cell viability after performing the Aβ uptake assay and then calculated Aβ uptake level after normalizing the data based on cell viability (Figure S7B).”

• AssumptionRests on an assumption: Aβ uptake is strongly influenced by cell density.

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

Functional interactions between Spi1 and Syk, Lyn, and Fcgr1 occur via pathways enriched in phagocytosis pathways.

“In addition, their functional interactions were suggested to occur via pathways enriched in phagocytosis pathways (Table S6).”

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

Using non-floxed mice as negative control and injecting tamoxifen to both experimental groups ensured observed effects were not due to leaky Cre activity.

“This approach ensured that any observed effects were not due to leaky Cre activity since we used non-floxed mice as a negative control group.”

• AssumptionRests on an assumption: The Cx3cr1CreER mouse line allows inducible deletion of the Spi1 gene in myeloid cells upon tamoxifen injection.

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

Immune response_Phagocytosis was the most enriched network, supporting the validity of functional experiments in Figure 5.

“Our biological pathway enrichment analysis revealed “Immune response_Phagocytosis” as the most enriched network, further supporting the validity of our functional experiments in Figure 5.”

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

The in vitro experiments were performed in quadruplicate and independently repeated twice.

“All experiments were performed in quadruplicate and repeated independently twice.”

• Also stated in: § METHOD DETAILS · plain

  “All experiments were performed in quadruplicate and repeated independently twice.”

• Also stated in: § METHOD DETAILS · plain

  “All experiments were performed in quadruplicate and repeated independently twice.”

May combine two claims.

This reduction leads to impaired microglial Aβ clearance, consequently exacerbating AD phenotypes including Aβ accumulation, amyloid plaque deposition, gliosis, and dystrophic neurites.

“This reduction led to the impaired microglial Aβ clearance, consequently exacerbating several phenotypes associated with AD, including Aβ peptides accumulation, amyloid plaque deposition, gliosis, and dystrophic neurites.”

May combine two claims.

Reduced Spi1 expression in microglia may worsen AD pathogenesis, contrary to expectation from the peripheral protective allele association.

“These results suggest that reduced Spi1 expression in microglia may actually worsen AD pathogenesis, contrary to what might be expected based on the association of the protective allele and its lower mRNA levels in peripheral immune cells.”

Probably not a substantial claim: may not pass S2 (checkable).

The SPI1 downstream pathway is a potentially promising avenue for AD therapeutic targets.

“Based on the combined findings from our functional data and mechanistic investigations in this study, SPI1 downstream pathway emerges as a potentially promising avenue for exploring potential therapeutic targets for AD.”

Classified as probably not a substantial claim.

All datasets satisfied equal variance and normality assumptions for the statistical tests used.

“All data sets passed the equal variance test (F test or Brown-Forsythe test) and normality test (Shapiro–Wilk test).”

May combine two claims.

SPI1 plays a crucial role in microglial function and AD pathogenesis.

“These results strongly suggest that SPI1 plays a crucial role in microglial function and the pathogenesis of AD.”