Interferon signaling modulates Down syndrome-associated Alzheimer’s disease pathology in a mouse model

May combine two claims.

People with DS present increased IFN signaling likely driven by triplication of four of the six IFN receptors encoded on HSA21, rather than by massive elevation of IFN ligands, and this has been associated with chronic immune dysregulation.

“people with DS present an increased IFN signaling likely driven by triplication of four of the six IFN receptors encoded on HSA21,36 rather than by massive elevation of the IFN ligands themselves as seen in interferonopathies,80 and this has been associated with chronic immune dysregulation.”

• cites [36] Sullivan K.D. Lewis H.C. Hill A.A. Pandey A. Jackson L.P. Cabral J.M. Smith K.P. Liggett L.A. Gomez E.B. Galbraith M.D. Trisomy 21 consistently activates the interferon response eLife 5 2016 e16220 10.7554/eLife.16220 PMC5012864 27472900 sourceSupported
• cites [80] Rodero M.P. Crow Y.J. Type I interferon–mediated monogenic autoinflammation: The type I interferonopathies, a conceptual overview J. Exp. Med. 213 2016 2527 2538 10.1084/jem.20161596 27821552 PMC5110029 sourceDisputed

  The citation is attached to the comparison with interferonopathies, not to the Down syndrome receptor-triplication claim. In “Is it appropriate to use the term type I interferonopathies (I)?” (page unavailable), the paper says circulating interferons are likely present at low levels and are difficult to measure directly; it does not describe massive elevation of IFN ligands in interferonopathies. It instead uses interferon-stimulated genes as a measure of increased signaling. (LLM, conf=0.86)

  Checked by a reasoning model — may be wrong.

  Experimental — accuracy not yet measured
• cites [30] Zhang Y. Che M. Yuan J. Yu Y. Cao C. Qin X.Y. Cheng Y. Aberrations in circulating inflammatory cytokine levels in patients with Down syndrome: a meta-analysis Oncotarget 8 2017 84489 84496 10.18632/oncotarget.21060 29137441 PMC5663613 sourcePartly supported

  The Discussion reports hyperactivity of the IFN-γ pathway and an aberrant inflammatory response in people with Down syndrome. The Results and Discussion also report significantly elevated circulating IFN-γ, with a large effect size. The paper does not compare ligand levels with interferonopathies or establish that ligand elevation is not massive; the receptor-triplication detail is attached to a different citation in the citing sentence. (LLM, conf=0.83)

  Experimental — accuracy not yet measured
• cites [31] Sullivan K.D. Evans D. Pandey A. Hraha T.H. Smith K.P. Markham N. Rachubinski A.L. Wolter-Warmerdam K. Hickey F. Espinosa J.M. Blumenthal T. Trisomy 21 causes changes in the circulating proteome indicative of chronic autoinflammation Sci. Rep. 7 2017 14818 10.1038/s41598-017-13858-3 PMC5665944 29093484 sourcePartly supported

  The Results and Discussion report a pro-inflammatory proteome in people with DS with ties to interferon signaling, and the Final Remarks describe profound immune dysregulation. The paper also discusses overexpression of four chromosome-21 interferon receptors, but our copy does not establish the claimed contrast with a massive elevation of interferon ligands. That ligand comparison is not supported by this source. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites [32] Huggard D. Doherty D.G. Molloy E.J. Immune Dysregulation in Children With Down Syndrome Front. Pediatr. 8 2020 73 10.3389/fped.2020.00073 PMC7056667 32175298 sourcePartly supported

  The Complement Pathway section associates Down syndrome with type 1 interferonopathies and persistent inflammation, broadly supporting the interferon-response and immune-dysregulation portions of the claim. Our copy does not state that increased signaling is driven by triplication of four of six interferon receptors on chromosome 21. The ligand comparison is attached to a different citation in the citing sentence. (LLM, conf=0.82)

  Experimental — accuracy not yet measured
• cites [33] Huggard D. Kelly L. Ryan E. McGrane F. Lagan N. Roche E. Balfe J. Leahy T.R. Franklin O. Doherty D.G. Molloy E.J. Increased systemic inflammation in children with Down syndrome Cytokine 127 2020 154938 10.1016/j.cyto.2019.154938 31785499 sourceNot checked — no full text of the source
• cites [34] Araya P. Waugh K.A. Sullivan K.D. Núñez N.G. Roselli E. Smith K.P. Granrath R.E. Rachubinski A.L. Enriquez Estrada B. Butcher E.T. Trisomy 21 dysregulates T cell lineages toward an autoimmunity-prone state associated with interferon hyperactivity Proc. Natl. Acad. Sci. USA 116 2019 24231 24241 10.1073/pnas.1908129116 31699819 PMC6883781 sourceSupported
• cites [35] Waugh K.A. Araya P. Pandey A. Jordan K.R. Smith K.P. Granrath R.E. Khanal S. Butcher E.T. Estrada B.E. Rachubinski A.L. Mass Cytometry Reveals Global Immune Remodeling with Multi-lineage Hypersensitivity to Type I Interferon in Down Syndrome Cell Rep. 29 2019 1893 1908.e4 10.1016/j.celrep.2019.10.038 31722205 PMC6871766 sourceSupported
• cites [86] Lambert K. Moo K.G. Arnett A. Goel G. Hu A. Flynn K.J. Speake C. Wiedeman A.E. Gersuk V.H. Linsley P.S. Deep immune phenotyping reveals similarities between aging, Down syndrome, and autoimmunity Sci. Transl. Med. 14 2022 eabi4888 10.1126/scitranslmed.abi4888 PMC9312285 35020411 sourcePartly supported

  The Results section on naïve CD4+ T cells says IFN signaling is enhanced in Down syndrome because of overexpression of chromosome 21-encoded IFN receptor subunits, and reports elevated pSTAT1 in DS T cells. It does not specify that four of six IFN receptors are encoded on chromosome 21. The ligand comparison is attached to a different citation in the citing sentence and is not assessed against this paper. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

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

Recent studies indicate an increased ratio of inhibitory to excitatory neurons in the cortex and hippocampus in Dp16 mice that is associated with deficits in learning, memory, and motor function.

“recent studies that indicate an increased ratio of inhibitory to excitatory neurons in the cortex and hippocampus in Dp16 mice that is associated with deficits in learning, memory, and motor function.”

• cites [24] Palmer C.R. Liu C.S. Romanow W.J. Lee M.-H. Chun J. Altered cell and RNA isoform diversity in aging Down syndrome brains Proc. Natl. Acad. Sci. USA 118 2021 e2114326118 10.1073/pnas.2114326118 PMC8617492 34795060 sourcePartly supported

  The Results section on DS prefrontal cortex reports an increased proportion of inhibitory neurons in human Down syndrome brains and notes a similar imbalance in the Ts65Dn mouse model. It does not establish that the ratio is increased in the cortex and hippocampus of Dp16 mice or associate that ratio with learning, memory, and motor deficits. The passage mentioning Dp16 instead concerns dendritic spine density. (LLM, conf=0.87)

  Experimental — accuracy not yet measured
• cites [40] Aziz N.M. Guedj F. Pennings J.L.A. Olmos-Serrano J.L. Siegel A. Haydar T.F. Bianchi D.W. Lifespan analysis of brain development, gene expression and behavioral phenotypes in the Ts1Cje, Ts65Dn and Dp(16)1/Yey mouse models of Down syndrome Dis. Model. Mech. 11 2018 dmm031013 10.1242/dmm.031013 PMC6031353 29716957 sourceDisputed

  The Results section (Excitatory and inhibitory neuronal density; Fig. 4) reports decreased cortical PV+ and SS+ inhibitory neurons and no change in hippocampal inhibitory populations in Dp(16)1/Yey mice, not an increased inhibitory-to-excitatory ratio in both regions. The Discussion reports behavioral deficits in these mice, but does not establish the claimed association with an increased ratio. Page numbers were unavailable in our copy. (LLM, conf=0.89)

  Checked by a reasoning model — may be wrong.

  Experimental — accuracy not yet measured
• cites [44] Goodliffe J.W. Olmos-Serrano J.L. Aziz N.M. Pennings J.L.A. Guedj F. Bianchi D.W. Haydar T.F. Absence of Prenatal Forebrain Defects in the Dp(16)1Yey/+ Mouse Model of Down Syndrome J. Neurosci. 36 2016 2926 2944 10.1523/JNEUROSCI.2513-15.2016 26961948 PMC4783496 sourceDisputed

  The section on P15 neuronal populations reports fewer PV-positive and Sst-positive inhibitory interneurons in Dp16 somatosensory cortex, not an increased inhibitory-to-excitatory ratio; it attributes higher inhibition in cortex and hippocampus to prior findings in Ts65Dn mice. The Motor assessment and Cognitive assessment sections do report motor, learning, and memory deficits in Dp16 mice, but do not establish the claimed association with an increased ratio. Page numbers were not provided in our copy. (LLM, conf=0.88)

  Checked by a reasoning model — may be wrong.

  Experimental — accuracy not yet measured
• cites [87] Raveau M. Polygalov D. Boehringer R. Amano K. Yamakawa K. McHugh T.J. Alterations of in vivo CA1 network activity in Dp(16)1Yey Down syndrome model mice eLife 7 2018 e31543 10.7554/eLife.31543 PMC5841929 29485402 sourcePartly supported

  The Results (CA1 interneuron density; page unavailable) report increased density of a specific inhibitory-neuron subtype in the hippocampus of Dp16 mice. The Discussion links these changes tentatively to spatial learning and memory deficits. The paper does not establish an increased inhibitory-to-excitatory neuron ratio across the cortex and hippocampus, or link that ratio to motor-function deficits. (LLM, conf=0.90)

  Experimental — accuracy not yet measured

May combine two claims.

Individuals with Down syndrome (T21) are strongly predisposed to Alzheimer's disease, with nearly all exhibiting AD-related neuropathological features by age ∼40 and highly variable onset of dementia thereafter.

“Individuals with Down syndrome (DS), caused by trisomy of chromosome 21 (chr21, T21), are strongly predisposed to Alzheimer’s disease (AD), due to triplication of the APP gene, with ∼100% penetrance of AD brain pathology by age 40 and variable onset of dementia thereafter.”

• Also stated in: § Introduction · plain

  “Remarkably, nearly all people with T21 exhibit Alzheimer’s disease (AD)-related neuropathological features by the age of ∼40, including development of amyloid-β (Aβ) plaques, neurofibrillary tangles, synaptic dysfunction, and neuroinflammation in several brain regions;6,7,8 however, the onset of dementia is highly variable.9,10,11”

• cites [6] Head E. Lott I.T. Wilcock D.M. Lemere C.A. Aging in Down Syndrome and the Development of Alzheimer's Disease Neuropathology Curr. Alzheimer Res. 13 2016 18 29 10.2174/1567205012666151020114607 26651341 PMC4948181 sourceSupported
• cites [7] Wisniewski K.E. Dalton A.J. McLachlan C. Wen G.Y. Wisniewski H.M. Alzheimer's disease in Down's syndrome: clinicopathologic studies Neurology 35 1985 957 961 10.1212/wnl.35.7.957 3159974 sourcePartly supported

  The Abstract reports Alzheimer’s pathology in seven Down syndrome patients older than 40, and the Results (Morphometric methods) give varying ages of cognitive-symptom onset, from 43.2 to 57.6 years. The study does not establish that nearly all people with Down syndrome have AD pathology by age 40; its seven patients were older than 40 and had clinical AD. Our copy also does not attribute the predisposition to APP gene triplication. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [8] Leverenz J.B. Raskind M.A. Early amyloid deposition in the medial temporal lobe of young Down syndrome patients: a regional quantitative analysis Exp. Neurol. 150 1998 296 304 10.1006/exnr.1997.6777 9527899 sourceNot checked — no full text of the source
• cites [9] Lott I.T. Head E. Dementia in Down syndrome: unique insights for Alzheimer disease research Nat. Rev. Neurol. 15 2019 135 147 10.1038/s41582-018-0132-6 30733618 PMC8061428 sourceSupported
• cites [10] Wilcock D.M. Griffin W.S.T. Down's syndrome, neuroinflammation, and Alzheimer neuropathogenesis J. Neuroinflammation 10 2013 84 10.1186/1742-2094-10-84 23866266 PMC3750399 sourceSupported
• cites [11] Hartley D. Blumenthal T. Carrillo M. DiPaolo G. Esralew L. Gardiner K. Granholm A.C. Iqbal K. Krams M. Lemere C. Down syndrome and Alzheimer's disease: Common pathways, common goals Alzheimer's Dement. 11 2015 700 709 10.1016/j.jalz.2014.10.007 25510383 PMC4817997 sourceSupported

May combine two claims.

There is substantial evidence of neuropathology from early in life in DS, including defects in neuronal development, increased ratio of inhibitory to excitatory neurons, alterations in neuronal dendritic spine dynamics, activation of microglia, astrocyte reactivity, and elevated production of inflammatory cytokines in the brain.

“There is substantial evidence of neuropathology from early in life in DS,6,9,10,21 including defects in neuronal development, an increased ratio of inhibitory to excitatory neurons, alterations in neuronal dendritic spines dynamics, activation of microglia, astrocyte reactivity, and elevated production of inflammatory cytokines in the brain.22,23,24,25”

• cites [6] Head E. Lott I.T. Wilcock D.M. Lemere C.A. Aging in Down Syndrome and the Development of Alzheimer's Disease Neuropathology Curr. Alzheimer Res. 13 2016 18 29 10.2174/1567205012666151020114607 26651341 PMC4948181 sourcePartly supported

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

  Experimental — accuracy not yet measured
• cites [9] Lott I.T. Head E. Dementia in Down syndrome: unique insights for Alzheimer disease research Nat. Rev. Neurol. 15 2019 135 147 10.1038/s41582-018-0132-6 30733618 PMC8061428 sourcePartly supported

  The Neuropathogenesis section (page unavailable) reports developmental abnormalities beginning in utero, including disrupted neurogenesis and synaptogenesis. The Neuroinflammation section (page unavailable) reports altered microglia in adults over 40 and increased IL-1β expression in astrocytes, but does not establish these inflammatory changes from early life. The passages do not support the claimed inhibitory-to-excitatory neuron ratio or dendritic-spine dynamics; the reported increases in several inflammatory cytokines are in serum or plasma, not brain. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [10] Wilcock D.M. Griffin W.S.T. Down's syndrome, neuroinflammation, and Alzheimer neuropathogenesis J. Neuroinflammation 10 2013 84 10.1186/1742-2094-10-84 23866266 PMC3750399 sourcePartly supported

  The Introduction reports glial activation and excessive inflammatory cytokine expression in DS fetuses, infants, and children; its Summary specifies activated microglia and astrocytes. Our copy does not establish the claimed defects in neuronal development, increased inhibitory-to-excitatory neuron ratio, or altered dendritic spine dynamics. (LLM, conf=0.87)

  Experimental — accuracy not yet measured
• cites [21] Araya P. Kinning K.T. Coughlan C. Smith K.P. Granrath R.E. Enriquez-Estrada B.A. Worek K. Sullivan K.D. Rachubinski A.L. Wolter-Warmerdam K. IGF1 deficiency integrates stunted growth and neurodegeneration in Down syndrome Cell Rep. 41 2022 111883 10.1016/j.celrep.2022.111883 PMC9876612 36577365 sourcePartly supported

  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 [22] Flores-Aguilar L. Iulita M.F. Kovecses O. Torres M.D. Levi S.M. Zhang Y. Askenazi M. Wisniewski T. Busciglio J. Cuello A.C. Evolution of neuroinflammation across the lifespan of individuals with Down syndrome Brain 143 2020 3653 3671 10.1093/brain/awaa326 33206953 PMC7805813 sourcePartly supported

  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 [23] Haydar T.F. Reeves R.H. Trisomy 21 and early brain development Trends Neurosci. 35 2012 81 91 10.1016/j.tins.2011.11.001 22169531 PMC3273608 sourcePartly supported

  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 [24] Palmer C.R. Liu C.S. Romanow W.J. Lee M.-H. Chun J. Altered cell and RNA isoform diversity in aging Down syndrome brains Proc. Natl. Acad. Sci. USA 118 2021 e2114326118 10.1073/pnas.2114326118 PMC8617492 34795060 sourcePartly supported

  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 [25] Ponroy Bally B. Murai K.K. Astrocytes in Down Syndrome Across the Lifespan Front. Cell. Neurosci. 15 2021 702685 10.3389/fncel.2021.702685 PMC8416355 34483840 sourcePartly supported

  “General Features of the DS Brain” reports reduced neuronal production and abnormal dendritic spines, while “Astrocytes and Alzheimer’s Disease Pathology in DS” reports early astrocyte reactivity, microglial activation, and cytokine production in childhood. The copy does not establish an increased ratio of inhibitory to excitatory neurons; “DS Astrocytes and the Development of Brain Connectivity” discusses altered GABA transmission instead. Page numbers were not available in the indexed passages. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

Classified as probably not a substantial claim.

Many additional genes on HSA21 modulate processes that could contribute to AD pathology in DS.

“However, many additional genes on HSA21 modulate processes that could contribute to AD pathology in DS.14,15,16”

• cites [14] Kimura R. Kamino K. Yamamoto M. Nuripa A. Kida T. Kazui H. Hashimoto R. Tanaka T. Kudo T. Yamagata H. The DYRK1A gene, encoded in chromosome 21 Down syndrome critical region, bridges between beta-amyloid production and tau phosphorylation in Alzheimer disease Hum. Mol. Genet. 16 2007 15 23 10.1093/hmg/ddl437 17135279 sourcePartly supported

  The Discussion (page unavailable) reports AD-associated markers linked to six chromosome 21 genes, and the paper describes how DYRK1A may connect amyloid accumulation to tau phosphorylation. The other genes are discussed mainly through their known functions and genetic associations; the paper does not establish that many of them modulate processes contributing to AD pathology specifically in Down syndrome. (LLM, conf=0.83)

  Experimental — accuracy not yet measured
• cites [15] Mok K.Y. Jones E.L. Hanney M. Harold D. Sims R. Williams J. Ballard C. Hardy J. Polymorphisms in BACE2 may affect the age of onset Alzheimer's dementia in Down syndrome Neurobiol. Aging 35 2014 1513.e1 1513.e15135 10.1016/j.neurobiolaging.2013.12.022 PMC3969241 24462566 sourcePartly supported

  The Introduction identifies APP and BACE2 as chromosome 21 genes related to AD, and the Discussion proposes that BACE2 may influence dementia pathogenesis in people with trisomy 21. This supports an additional gene beyond APP, but the paper does not establish that many additional HSA21 genes modulate relevant processes. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [16] Snyder H.M. Bain L.J. Brickman A.M. Carrillo M.C. Esbensen A.J. Espinosa J.M. Fernandez F. Fortea J. Hartley S.L. Head E. Further understanding the connection between Alzheimer's disease and Down syndrome Alzheimer's Dement. 16 2020 1065 1077 10.1002/alz.12112 32544310 PMC8865308 sourceSupported

May combine two claims.

Dp16 mice exhibit impaired motor coordination at 3 and 5 months of age relative to WT littermates, with a trend toward poorer performance at 7 and 9 months of age.

“We next tested motor coordination using the accelerating rotarod test DS-AD mice (Data S4), and consistent with previous reports,38,40 we found that Dp16 mice exhibit impaired motor coordination at 3 and 5 months of age relative to WT littermates, with a trend toward poorer performance at 7 and 9 months of age (Figure 2A).”

• cites [38] Waugh K.A. Minter R. Baxter J. Chi C. Galbraith M.D. Tuttle K.D. Eduthan N.P. Kinning K.T. Andrysik Z. Araya P. Triplication of the interferon receptor locus contributes to hallmarks of Down syndrome in a mouse model Nat. Genet. 55 2023 1034 1047 10.1038/s41588-023-01399-7 37277650 PMC10260402 sourceSupported
• cites [40] Aziz N.M. Guedj F. Pennings J.L.A. Olmos-Serrano J.L. Siegel A. Haydar T.F. Bianchi D.W. Lifespan analysis of brain development, gene expression and behavioral phenotypes in the Ts1Cje, Ts65Dn and Dp(16)1/Yey mouse models of Down syndrome Dis. Model. Mech. 11 2018 dmm031013 10.1242/dmm.031013 PMC6031353 29716957 sourceSupported

May combine two claims.

Both individuals with DS and mouse models of DS experience constitutive hyperactivation of interferon (IFN) signaling with signs of chronic inflammation and immune dysregulation, which could exacerbate the neuroinflammatory response.

“Notably, both individuals with DS and mouse models of DS experience constitutive hyperactivation of interferon (IFN) signaling with signs of chronic inflammation and immune dysregulation,30,31,32,33,34,35,36,37,38,39,40 that could exacerbate the neuroinflammatory response.”

• cites [30] Zhang Y. Che M. Yuan J. Yu Y. Cao C. Qin X.Y. Cheng Y. Aberrations in circulating inflammatory cytokine levels in patients with Down syndrome: a meta-analysis Oncotarget 8 2017 84489 84496 10.18632/oncotarget.21060 29137441 PMC5663613 sourcePartly supported

  The Discussion reports elevated IFN-γ and neopterin in patients with Down syndrome and describes this as evidence of IFN-γ pathway hyperactivity and a heightened inflammatory response. It does not study mouse models or establish constitutive hyperactivation of IFN signaling in them. It suggests that IFN signaling may accelerate AD neuropathogenesis in Down syndrome, rather than demonstrating an exacerbated neuroinflammatory response. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [31] Sullivan K.D. Evans D. Pandey A. Hraha T.H. Smith K.P. Markham N. Rachubinski A.L. Wolter-Warmerdam K. Hickey F. Espinosa J.M. Blumenthal T. Trisomy 21 causes changes in the circulating proteome indicative of chronic autoinflammation Sci. Rep. 7 2017 14818 10.1038/s41598-017-13858-3 PMC5665944 29093484 sourcePartly supported

  The Results and Discussion report a pro-inflammatory circulating proteome in people with Down syndrome, with multiple ties to interferon signaling; the Final Remarks describe profound immune dysregulation. The paper does not establish constitutive interferon hyperactivation or chronic inflammation in Down syndrome mouse models. The clause about a possible exacerbation of neuroinflammation follows the citation cluster and is not attributed to this source. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [32] Huggard D. Doherty D.G. Molloy E.J. Immune Dysregulation in Children With Down Syndrome Front. Pediatr. 8 2020 73 10.3389/fped.2020.00073 PMC7056667 32175298 sourcePartly supported

  The Cytokines section (page unavailable) reports elevated IFN-γ and baseline inflammatory markers in people with Down syndrome; the Complement Pathway section links Down syndrome to type 1 interferonopathies and persistent inflammation. These passages support the human inflammation and immune-dysregulation portions, but do not establish constitutive hyperactivation of IFN signaling in both people and mouse models of Down syndrome. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [33] Huggard D. Kelly L. Ryan E. McGrane F. Lagan N. Roche E. Balfe J. Leahy T.R. Franklin O. Doherty D.G. Molloy E.J. Increased systemic inflammation in children with Down syndrome Cytokine 127 2020 154938 10.1016/j.cyto.2019.154938 31785499 sourceNot checked — no full text of the source
• cites [34] Araya P. Waugh K.A. Sullivan K.D. Núñez N.G. Roselli E. Smith K.P. Granrath R.E. Rachubinski A.L. Enriquez Estrada B. Butcher E.T. Trisomy 21 dysregulates T cell lineages toward an autoimmunity-prone state associated with interferon hyperactivity Proc. Natl. Acad. Sci. USA 116 2019 24231 24241 10.1073/pnas.1908129116 31699819 PMC6883781 sourcePartly supported

  The Abstract and Results report elevated basal IFN signaling, chronic inflammation, and T-cell dysregulation in people with Down syndrome. The paper does not establish the same findings in mouse models of Down syndrome, which are also included in the cited claim. The proposed neuroinflammatory consequence appears after the citations and is not treated as a finding attributed to this source. (LLM, conf=0.87)

  Experimental — accuracy not yet measured
• cites [35] Waugh K.A. Araya P. Pandey A. Jordan K.R. Smith K.P. Granrath R.E. Khanal S. Butcher E.T. Estrada B.E. Rachubinski A.L. Mass Cytometry Reveals Global Immune Remodeling with Multi-lineage Hypersensitivity to Type I Interferon in Down Syndrome Cell Rep. 29 2019 1893 1908.e4 10.1016/j.celrep.2019.10.038 31722205 PMC6871766 sourcePartly supported

  The Introduction reports global immune dysregulation and heightened IFN responsiveness in adults with Down syndrome; the Results report elevated baseline signaling and point to chronic IFN hyperactivity. The paper does not establish the same findings in mouse models of Down syndrome. The proposed exacerbation of neuroinflammation follows the citation and is not treated here as attributed to this source. Page numbers were unavailable in our copy. (LLM, conf=0.87)

  Experimental — accuracy not yet measured
• cites [36] Sullivan K.D. Lewis H.C. Hill A.A. Pandey A. Jackson L.P. Cabral J.M. Smith K.P. Liggett L.A. Gomez E.B. Galbraith M.D. Trisomy 21 consistently activates the interferon response eLife 5 2016 e16220 10.7554/eLife.16220 PMC5012864 27472900 sourcePartly supported

  The Results report IFN-response gene activation in a DS mouse model, and the Discussion describes widespread IFN-pathway activation in human trisomy 21 cells and relevance to mouse models with triplicated IFN receptors. The Discussion also links DS to inflammatory and autoimmune conditions, but does not establish signs of chronic inflammation and immune dysregulation in both individuals and mouse models. It proposes, rather than demonstrates, a neurological effect through microglial activation. (LLM, conf=0.83)

  Experimental — accuracy not yet measured
• cites [37] Tuttle K.D. Waugh K.A. Araya P. Minter R. Orlicky D.J. Ludwig M. Andrysik Z. Burchill M.A. Tamburini B.A.J. Sempeck C. JAK1 Inhibition Blocks Lethal Immune Hypersensitivity in a Mouse Model of Down Syndrome Cell Rep. 33 2020 108407 10.1016/j.celrep.2020.108407 PMC7727402 33207208 sourcePartly supported

  The Abstract reports IFN-signaling hyperactivation and chronic inflammation in individuals with DS, and the Results show that Dp16 mice are unusually responsive to IFN stimulation. But the Results also report no significant difference in basal pSTAT1 in Dp16 immune cells; the mouse findings therefore do not support describing IFN signaling as constitutively hyperactivated. The proposed neuroinflammatory consequence follows the citations and is not attributed to this source. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [38] Waugh K.A. Minter R. Baxter J. Chi C. Galbraith M.D. Tuttle K.D. Eduthan N.P. Kinning K.T. Andrysik Z. Araya P. Triplication of the interferon receptor locus contributes to hallmarks of Down syndrome in a mouse model Nat. Genet. 55 2023 1034 1047 10.1038/s41588-023-01399-7 37277650 PMC10260402 sourceSupported
• cites [39] Galbraith M.D. Rachubinski A.L. Smith K.P. Araya P. Waugh K.A. Enriquez-Estrada B. Worek K. Granrath R.E. Kinning K.T. Paul Eduthan N. Multidimensional definition of the interferonopathy of Down syndrome and its response to JAK inhibition Sci. Adv. 9 2023 eadg6218 10.1126/sciadv.adg6218 PMC10306300 37379383 sourceSupported

May combine two claims.

Dp16 mice exhibit hyperactive IFN signaling and recapitulate many phenotypes of DS including developmental delays, cranial malformations, and cognitive deficits.

“Notably, Dp16 mice exhibit hyperactive IFN signaling and recapitulate many phenotypes of DS including developmental delays, cranial malformations, and cognitive deficits.38,40,42,43,44,45”

• cites [38] Waugh K.A. Minter R. Baxter J. Chi C. Galbraith M.D. Tuttle K.D. Eduthan N.P. Kinning K.T. Andrysik Z. Araya P. Triplication of the interferon receptor locus contributes to hallmarks of Down syndrome in a mouse model Nat. Genet. 55 2023 1034 1047 10.1038/s41588-023-01399-7 37277650 PMC10260402 sourceSupported
• cites [40] Aziz N.M. Guedj F. Pennings J.L.A. Olmos-Serrano J.L. Siegel A. Haydar T.F. Bianchi D.W. Lifespan analysis of brain development, gene expression and behavioral phenotypes in the Ts1Cje, Ts65Dn and Dp(16)1/Yey mouse models of Down syndrome Dis. Model. Mech. 11 2018 dmm031013 10.1242/dmm.031013 PMC6031353 29716957 sourcePartly supported

  The Results report upregulated interferon signaling in Dp(16)1/Yey brains, and the Discussion reports delays in late-acquired developmental milestones and adult learning and memory deficits. The source does not establish cranial malformations in these mice; its Summary of brain phenotypes by model instead reports no measurable embryonic brain-growth or forebrain-morphogenesis defects (page unavailable). (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [42] Li Z. Yu T. Morishima M. Pao A. LaDuca J. Conroy J. Nowak N. Matsui S.I. Shiraishi I. Yu Y.E. Duplication of the entire 22.9 Mb human chromosome 21 syntenic region on mouse chromosome 16 causes cardiovascular and gastrointestinal abnormalities Hum. Mol. Genet. 16 2007 1359 1366 10.1093/hmg/ddm086 17412756 sourceNot checked — no full text of the source
• cites [43] Starbuck J.M. Dutka T. Ratliff T.S. Reeves R.H. Richtsmeier J.T. Overlapping trisomies for human chromosome 21 orthologs produce similar effects on skull and brain morphology of Dp(16)1Yey and Ts65Dn mice Am. J. Med. Genet. 164A 2014 1981 1990 10.1002/ajmg.a.36594 24788405 PMC4107150 sourcePartly supported

  The Discussion (page not provided) reports Down syndrome-like craniofacial abnormalities and cerebellar differences in Dp(16)1Yey mice. Our copy does not report hyperactive IFN signaling, developmental delays, or cognitive deficits in these mice; its mention of behavioral effects in the Introduction concerns Ts65Dn mice. (LLM, conf=0.90)

  Experimental — accuracy not yet measured
• cites [44] Goodliffe J.W. Olmos-Serrano J.L. Aziz N.M. Pennings J.L.A. Guedj F. Bianchi D.W. Haydar T.F. Absence of Prenatal Forebrain Defects in the Dp(16)1Yey/+ Mouse Model of Down Syndrome J. Neurosci. 36 2016 2926 2944 10.1523/JNEUROSCI.2513-15.2016 26961948 PMC4783496 sourcePartly supported

  The Introduction reports craniofacial dysmorphology in Dp16 mice, and the paper reports delayed postnatal developmental milestones and impaired adult cognitive performance. Neither the supplied passages nor a search of our copy for IFN and interferon signaling supports the claim of hyperactive IFN signaling. Page numbers were not available in our copy. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [45] Yu T. Liu C. Belichenko P. Clapcote S.J. Li S. Pao A. Kleschevnikov A. Bechard A.R. Asrar S. Chen R. Effects of individual segmental trisomies of human chromosome 21 syntenic regions on hippocampal long-term potentiation and cognitive behaviors in mice Brain Res. 1366 2010 162 171 10.1016/j.brainres.2010.09.107 20932954 PMC3027718 sourcePartly supported

  The Discussion (page unavailable) reports that Dp(16)1Yey/+ mice have Down-syndrome-related cognitive phenotypes, including impaired learning and memory. This paper does not report hyperactive IFN signaling, developmental delays, or cranial malformations in these mice; searches for those terms found no supporting passage. (LLM, conf=0.87)

  Experimental — accuracy not yet measured

May combine two claims.

The 5xFAD transgenic mouse overexpresses human APP with three familial AD mutations (Swedish K670N/M671L, Florida I716V, London V717I) and human PSEN1 with two FAD mutations (M146L, L286V), causing accelerated formation of Aβ plaques and very high cerebral Aβ42 levels.

“The 5xFAD transgenic mouse overexpresses human APP with three familial AD (FAD) mutations (the Swedish [K670N and M671L], Florida [I716V], and London [V7171] mutations) and human PSEN1 with two FAD mutations (M146L and L286V), causing the accelerated formation of Aβ plaques and very high cerebral Aβ42 levels.46”

• cites [46] Oakley H. Cole S.L. Logan S. Maus E. Shao P. Craft J. Guillozet-Bongaarts A. Ohno M. Disterhoft J. Van Eldik L. Intraneuronal β-Amyloid Aggregates, Neurodegeneration, and Neuron Loss in Transgenic Mice with Five Familial Alzheimer's Disease Mutations: Potential Factors in Amyloid Plaque Formation J. Neurosci. 26 2006 10129 10140 10.1523/jneurosci.1202-06.2006 17021169 PMC6674618 sourceSupported

May combine two claims.

DNA repair, Myc targets V1, and oxidative phosphorylation gene sets are linked to cellular damage or stress facilitating the progression of pathogenesis and contributing to neurodegeneration in AD.

“Conversely, 5xFAD-Dp16 also exhibited greatly decreased NES for several gene sets, including DNA repair, Myc targets V1, and oxidative phosphorylation, all of which are linked to cellular damage or stress facilitating the progression of the pathogenesis and contributing to neurodegeneration in AD48,49,50 (Figures 3A and S3A).”

• cites [48] Wang H. Lautrup S. Caponio D. Zhang J. Fang E.F. DNA Damage-Induced Neurodegeneration in Accelerated Ageing and Alzheimer's Disease Int. J. Mol. Sci. 22 2021 6748 10.3390/ijms22136748 PMC8268089 34201700 sourcePartly supported

  Section 3.5 (AD; page not provided) links impaired DNA repair to AD pathogenesis and describes mitochondrial dysfunction and oxidative stress in AD. The paper does not establish that the named Myc targets V1 or oxidative phosphorylation gene sets contribute to AD neurodegeneration; its mitochondrial findings are broader than that gene-set claim. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [49] Lin X. Kapoor A. Gu Y. Chow M.J. Peng J. Zhao K. Tang D. Contributions of DNA Damage to Alzheimer's Disease Int. J. Mol. Sci. 21 2020 1666 10.3390/ijms21051666 PMC7084447 32121304 sourcePartly supported

  The Conclusions (page not available in our copy) link DNA damage and abnormalities in DNA repair to AD pathogenesis and neurodegeneration. The paper does not establish the claimed links for the Myc targets V1 or oxidative phosphorylation gene sets; searches for those terms found no supporting discussion. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [50] Schon E.A. Przedborski S. Mitochondria: The Next (Neurode)Generation Neuron 70 2011 1033 1053 10.1016/j.neuron.2011.06.003 21689593 PMC3407575 sourcePartly supported

  The mitochondrial–ER communication section identifies defects in energy metabolism and ER stress as features of AD, but says their causal links remain uncertain. The concluding remarks discuss impaired oxidative phosphorylation as a possible consequence in neurodegeneration, not an established cause. Our copy does not link the DNA repair or Myc targets V1 gene sets to AD pathogenesis. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

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

In preclinical models of DS-AD, triplication of HSA21 genes modulates Aβ aggregation and APP transgene-associated mortality independently of an extra copy of APP.

“Importantly, it has been shown in preclinical models of DS-AD that triplication of HSA21 genes modulates Aβ aggregation and APP transgene-associated mortality independently of an extra copy of APP.17,18”

• cites [17] Wiseman F.K. Pulford L.J. Barkus C. Liao F. Portelius E. Webb R. Chávez-Gutiérrez L. Cleverley K. Noy S. Sheppard O. Trisomy of human chromosome 21 enhances amyloid-β deposition independently of an extra copy of APP Brain 141 2018 2457 2474 10.1093/brain/awy159 29945247 PMC6061702 sourceSupported
• cites [18] Tosh J.L. Rhymes E.R. Mumford P. Whittaker H.T. Pulford L.J. Noy S.J. Cleverley K. LonDownS Consortium Walker M.C. Tybulewicz V.L.J. Genetic dissection of down syndrome-associated alterations in APP/amyloid-β biology using mouse models Sci. Rep. 11 2021 5736 10.1038/s41598-021-85062-3 33707583 PMC7952899 sourceSupported

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

USP25, a ubiquitin-specific protease encoded on HSA21, is a critical regulator of AD pathology, promoting β cleavage of APP and Aβ generation by reducing ubiquitination and lysosomal degradation of APP and BACE1 in DS-AD mice.

“Furthermore, it was recently reported that USP25, a ubiquitin-specific protease encoded on HSA21, is a critical regulator of AD pathology, as it promotes β cleavage of APP and Aβ generation by reducing the ubiquitination and lysosomal degradation of both APP and BACE1 in DS-AD mice.19,20”

• cites [19] Zheng Q. Song B. Li G. Cai F. Wu M. Zhao Y. Jiang L. Guo T. Shen M. Hou H. USP25 inhibition ameliorates Alzheimer's pathology through the regulation of APP processing and Aβ generation J. Clin. Investig. 132 2022 e152170 10.1172/jci152170 PMC8884900 35229730 sourcePartly supported

  The Introduction identifies USP25 as chromosome 21–encoded, and the Results section on BACE1 deubiquitination and APP β cleavage shows that USP25 reduces APP and BACE1 ubiquitination and protects them from degradation. The Results on increased USP25 gene dosage also report greater amyloid pathology in a combined DS-AD mouse model. However, the cited mechanistic experiments were not shown in those DS-AD mice, so the claim’s final qualifier overstates where that mechanism was demonstrated. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites [20] Zheng Q. Li G. Wang S. Zhou Y. Liu K. Gao Y. Zhou Y. Zheng L. Zhu L. Deng Q. Trisomy 21-induced dysregulation of microglial homeostasis in Alzheimer's brains is mediated by USP25 Sci. Adv. 7 2021 eabe1340 10.1126/sciadv.abe1340 PMC7775784 33523861 sourcePartly supported

  The Introduction identifies USP25 as a chromosome 21–encoded ubiquitin-specific protease, and the Discussion calls it a critical regulator of immune homeostasis in DS and AD. But the paper attributes its effects to microglial pathways, identifying WDFY1 and ATP6V0C as USP25 substrates; it does not support the claimed mechanism of APP and BACE1 stabilization, increased APP β-cleavage, or increased Aβ generation in DS-AD mice. The indexed copy supplies section labels but no page numbers. (LLM, conf=0.90)

  Experimental — accuracy not yet measured

May combine two claims.

Recent studies using complementary mouse models of DS (Ts65Dn, Ts2Cje, Tc1, Dp16) reported an activated microglia phenotype during brain development, with functional morphological alterations and elevated pro-inflammatory cytokines, accompanied by a reduction of neuronal dendritic spines.

“Recent studies using complementary mouse models of DS, including Ts65Dn, Ts2Cje, Tc1, and Dp16 mice, reported an activated phenotype in microglia cells during brain development, as evidenced by functional morphological alterations and elevated pro-inflammatory cytokines, accompanied by a reduction of neuronal dendritic spines.26,27,28,29”

• cites [26] Pinto B. Morelli G. Rastogi M. Savardi A. Fumagalli A. Petretto A. Bartolucci M. Varea E. Catelani T. Contestabile A. Rescuing Over-activated Microglia Restores Cognitive Performance in Juvenile Animals of the Dp(16) Mouse Model of Down Syndrome Neuron 108 2020 887 904.e12 10.1016/j.neuron.2020.09.010 33027640 PMC7736620 sourceSupported
• cites [27] Chiotto A.M.A. Migliorero M. Pallavicini G. Bianchi F.T. Gai M. Di Cunto F. Berto G.E. Neuronal Cell-Intrinsic Defects in Mouse Models of Down Syndrome Front. Neurosci. 13 2019 1081 10.3389/fnins.2019.01081 PMC6795679 31649502 sourcePartly supported

  The Results section, “Dendritic Spines of Trisomic Neurons in Primary Culture Show Immature Morphology and Reduced Density” (page unavailable), reports reduced spine density in Ts65Dn and Ts2Cje cortical neurons. The paper does not report activated microglia, elevated pro-inflammatory cytokines, or findings from Tc1 and Dp16 mice; searches for microglia and those models found no supporting passage. (LLM, conf=0.90)

  Experimental — accuracy not yet measured
• cites [28] Haas M.A. Bell D. Slender A. Lana-Elola E. Watson-Scales S. Fisher E.M.C. Tybulewicz V.L.J. Guillemot F. Alterations to dendritic spine morphology, but not dendrite patterning, of cortical projection neurons in Tc1 and Ts1Rhr mouse models of Down syndrome PLoS One 8 2013 e78561 10.1371/journal.pone.0078561 PMC3813676 24205261 sourcePartly supported

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

  Experimental — accuracy not yet measured
• cites [29] Real R. Peter M. Trabalza A. Khan S. Smith M.A. Dopp J. Barnes S.J. Momoh A. Strano A. Volpi E. In vivo modeling of human neuron dynamics and Down syndrome Science 362 2018 eaau1810 10.1126/science.aau1810 PMC6570619 30309905 sourceCould not verify

  Split into 2 atoms — 0 confirmed, 0 partially supported, 0 disputed, 0 misattributed, 2 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.

Aβ plaques in the 5xFAD brain appear at 2 months of age and increase in an age-dependent manner, becoming saturated by 6-9 months of age.

“Aβ plaques in the brain appear at 2 months of age and increase in an age-dependent manner, becoming saturated by 6–9 months of age.46”

• cites [46] Oakley H. Cole S.L. Logan S. Maus E. Shao P. Craft J. Guillozet-Bongaarts A. Ohno M. Disterhoft J. Van Eldik L. Intraneuronal β-Amyloid Aggregates, Neurodegeneration, and Neuron Loss in Transgenic Mice with Five Familial Alzheimer's Disease Mutations: Potential Factors in Amyloid Plaque Formation J. Neurosci. 26 2006 10129 10140 10.1523/jneurosci.1202-06.2006 17021169 PMC6674618 sourcePartly supported

  In “5XFAD mice rapidly accumulate massive Aβ42 levels in brain” (page unavailable), the paper reports that plaques appeared at 2 months in the Tg6799 line and increased rapidly with age, reaching massive levels by 6 months. It does not report that plaque burden saturated by 6–9 months; the other 5XFAD lines also began depositing plaques later, at 4 and 6 months. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

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

Previous studies in mouse models of DS-AD have shown that independently of an extra copy of APP, other genes on HSA21 can increase Aβ plaque deposition at 5 and 6 months of age, indicating that genes act early in the pathological cascade.

“previous studies in mouse models of DS-AD have shown that independently of an extra copy of APP, other genes on HSA21 can increase Aβ plaque deposition at 5 and 6 months of age, indicating that genes act early in the pathological cascade.”

• cites [18] Tosh J.L. Rhymes E.R. Mumford P. Whittaker H.T. Pulford L.J. Noy S.J. Cleverley K. LonDownS Consortium Walker M.C. Tybulewicz V.L.J. Genetic dissection of down syndrome-associated alterations in APP/amyloid-β biology using mouse models Sci. Rep. 11 2021 5736 10.1038/s41598-021-85062-3 33707583 PMC7952899 sourcePartly supported

  The Introduction and Discussion report that an earlier Tc1;tgAPP mouse study found increased Aβ deposition despite the Tc1 mice lacking an extra APP copy. But the paper does not place that deposition increase at 5 and 6 months or draw the stated conclusion about its timing. Its own Results report no significant increase in plaque deposition at 6 months in the segmental-duplication models studied (page numbers unavailable). (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [19] Zheng Q. Song B. Li G. Cai F. Wu M. Zhao Y. Jiang L. Guo T. Shen M. Hou H. USP25 inhibition ameliorates Alzheimer's pathology through the regulation of APP processing and Aβ generation J. Clin. Investig. 132 2022 e152170 10.1172/jci152170 PMC8884900 35229730 sourcePartly supported

  The Results (page not provided) report increased Aβ plaques in 5-month-old 5×FAD;Dp16 mice and in 6-month-old mice overexpressing the chromosome 21 gene USP25. But the 5-month-old Dp16 mice also had increased APP, so that experiment does not establish an APP-copy-independent effect at 5 months. The Discussion reports a previous APP-copy-independent finding in another DS-AD mouse model, without specifying its age. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

May combine two claims.

In APP/PS1 mice and 5xFAD mice, loss of type I IFN signaling is protective, ameliorating Aβ pathology and attenuating neurotoxicity, synapse loss, and microglial activation.

“In APP/PS1 mice and 5xFAD mice, loss of type I IFN signaling is protective ameliorating the Aβ pathology and attenuating neurotoxicity, synapse loss, and microglial activation.”

• cites [75] Roy E.R. Wang B. Wan Y.W. Chiu G. Cole A. Yin Z. Propson N.E. Xu Y. Jankowsky J.L. Liu Z. Type I interferon response drives neuroinflammation and synapse loss in Alzheimer disease J. Clin. Investig. 130 2020 1912 1930 10.1172/JCI133737 31917687 PMC7108898 sourcePartly supported

  In the section on IFN pathway activation in Aβ models (page not supplied), IFNAR blockade reduced microglial activation and restored synaptic markers in 5XFAD mice. The same section reports unaltered Aβ plaque load, contrary to the claimed amelioration of Aβ pathology. The paper does not establish the stated protective effects in APP/PS1 mice or directly show attenuated neurotoxicity. (LLM, conf=0.90)

  Experimental — accuracy not yet measured
• cites [78] Roy E.R. Chiu G. Li S. Propson N.E. Kanchi R. Wang B. Coarfa C. Zheng H. Cao W. Concerted type I interferon signaling in microglia and neural cells promotes memory impairment associated with amyloid β plaques Immunity 55 2022 879 894.e6 10.1016/j.immuni.2022.03.018 35443157 PMC9109419 sourcePartly supported

  The Results sections on IFN-I blockade report restored excitatory synapse markers, reduced microglial activation, and partial reductions in neuritic pathology in 5XFAD mice. But blockade did not reduce Aβ plaque load; only neural-cell-specific Ifnar1 deletion did. The paper does not report these protective effects as findings from its own APP/PS1 experiments, so the claim overgeneralizes across models and forms of IFN-I loss. (LLM, conf=0.90)

  Experimental — accuracy not yet measured
• cites [93] Minter M.R. Moore Z. Zhang M. Brody K.M. Jones N.C. Shultz S.R. Taylor J.M. Crack P.J. Deletion of the type-1 interferon receptor in APPSWE/PS1ΔE9 mice preserves cognitive function and alters glial phenotype Acta Neuropathol. Commun. 4 2016 72 10.1186/s40478-016-0341-4 27400725 PMC4940712 sourcePartly supported

  The Introduction and Discussion report that IFNAR1 deletion in APP/PS1 mice improved spatial cognition and reduced microgliosis; the Discussion also describes a neuroprotective effect in cultured cells. But the paper studies APP/PS1 mice, not 5xFAD mice, and does not establish reduced synapse loss. It reports only a modest reduction in soluble Aβ, with plaque deposition unchanged, so the broad claim of ameliorated Aβ pathology overstates its findings. Page numbers were not provided in our copy. (LLM, conf=0.90)

  Experimental — accuracy not yet measured

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

An additional copy of HSA21 genes can alter APP biology, including Aβ deposition, in other APP transgenic models.

“Previous studies have indicated that an additional copy of HSA21 genes can alter APP biology, including Aβ deposition in other APP transgenic models.”

• cites [17] Wiseman F.K. Pulford L.J. Barkus C. Liao F. Portelius E. Webb R. Chávez-Gutiérrez L. Cleverley K. Noy S. Sheppard O. Trisomy of human chromosome 21 enhances amyloid-β deposition independently of an extra copy of APP Brain 141 2018 2457 2474 10.1093/brain/awy159 29945247 PMC6061702 sourceSupported
• cites [18] Tosh J.L. Rhymes E.R. Mumford P. Whittaker H.T. Pulford L.J. Noy S.J. Cleverley K. LonDownS Consortium Walker M.C. Tybulewicz V.L.J. Genetic dissection of down syndrome-associated alterations in APP/amyloid-β biology using mouse models Sci. Rep. 11 2021 5736 10.1038/s41598-021-85062-3 33707583 PMC7952899 sourceSupported
• cites [19] Zheng Q. Song B. Li G. Cai F. Wu M. Zhao Y. Jiang L. Guo T. Shen M. Hou H. USP25 inhibition ameliorates Alzheimer's pathology through the regulation of APP processing and Aβ generation J. Clin. Investig. 132 2022 e152170 10.1172/jci152170 PMC8884900 35229730 sourceSupported
• cites [61] Sasaguri H. Nilsson P. Hashimoto S. Nagata K. Saito T. De Strooper B. Hardy J. Vassar R. Winblad B. Saido T.C. APP mouse models for Alzheimer's disease preclinical studies Embo j 36 2017 2473 2487 10.15252/embj.201797397 28768718 PMC5579350 sourceCould not verify

  The First-generation mouse models section describes APP transgenic mice with Aβ deposits, but does not address whether an additional copy of HSA21 genes alters APP biology or deposition. Searches for HSA21, trisomy 21, Down syndrome, and human chromosome 21 found no passage making that connection. (LLM, conf=0.74)

  Experimental — accuracy not yet measured
• cites [62] Mumford P. Tosh J. Anderle S. Gkanatsiou Wikberg E. Lau G. Noy S. Cleverley K. Saito T. Saido T.C. Yu E. Genetic Mapping of APP and Amyloid-beta Biology Modulation by Trisomy 21 J. Neurosci. 42 2022 6453 6468 10.1523/JNEUROSCI.0521-22.2022 35835549 PMC9398545 sourceSupported

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

Previous reports have shown that neuron loss in cortical layer V and subiculum, but not in other brain regions, is consistently associated with intraneuronal Aβ42 accumulation, Aβ plaque burden, spatial memory deficits, and working memory impairment in 5xFAD mice.

“previous reports have shown that neuron loss in the cortical layer V and subiculum, but not in other brain regions, is consistently associated with intraneuronal Aβ42 accumulation, Aβ plaque burden, as well as spatial memory deficits and working memory impairment in 5xFAD mice.”

• cites [46] Oakley H. Cole S.L. Logan S. Maus E. Shao P. Craft J. Guillozet-Bongaarts A. Ohno M. Disterhoft J. Van Eldik L. Intraneuronal β-Amyloid Aggregates, Neurodegeneration, and Neuron Loss in Transgenic Mice with Five Familial Alzheimer's Disease Mutations: Potential Factors in Amyloid Plaque Formation J. Neurosci. 26 2006 10129 10140 10.1523/jneurosci.1202-06.2006 17021169 PMC6674618 sourcePartly supported

  The neuron-loss findings (Fig. 7) place visible loss in cortical layer 5 and subiculum, the regions with the most intraneuronal Aβ and plaque deposition. The authors say other regions appeared relatively intact by visual inspection but were not counted, so loss elsewhere cannot be excluded. The memory sections report spatial working-memory and other memory deficits in 5XFAD mice, but do not establish that those deficits are consistently associated with neuron loss in those specific regions. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [88] Eimer W.A. Vassar R. Neuron loss in the 5XFAD mouse model of Alzheimer’s disease correlates with intraneuronal Aβ42 accumulation and Caspase-3 activation Mol. Neurodegener. 8 2013 2 10.1186/1750-1326-8-2 23316765 PMC3552866 sourcePartly supported

  The Results and Discussion report neuron loss in cortical layer V and subiculum alongside intraneuronal Aβ42 accumulation and greater plaque burden in those regions. The Background reports memory deficits by four months, but does not distinguish spatial from working memory or link either specifically to regional neuron loss. The paper also does not establish the claim’s exclusion of neuron loss in all other brain regions (page numbers unavailable). (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [89] Jawhar S. Trawicka A. Jenneckens C. Bayer T.A. Wirths O. Motor deficits, neuron loss, and reduced anxiety coinciding with axonal degeneration and intraneuronal Aβ aggregation in the 5XFAD mouse model of Alzheimer's disease Neurobiol. Aging 33 2012 196.e29 10.1016/j.neurobiolaging.2010.05.027 20619937 sourceNot checked — no full text of the source
• cites [90] Zhang J. Wu N. Wang S. Yao Z. Xiao F. Lu J. Chen B. Neuronal loss and microgliosis are restricted to the core of Aβ deposits in mouse models of Alzheimer's disease Aging Cell 20 2021 e13380 10.1111/acel.13380 PMC8208784 34080759 sourcePartly supported

  The Introduction (page unavailable) reports prior findings of neuron loss in cortical layer V and the subiculum, and separately reports a correlation between neuron loss and intraneuronal Aβ42 in 5xFAD mice. The Discussion (page unavailable) reports this paper’s correlation between neuronal loss and Aβ-deposit size. Neither passage establishes the claimed combined association with spatial-memory deficits or working-memory impairment; the Introduction also says earlier studies had not confirmed the relationship between deposits and neuron loss. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

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

Recent studies demonstrate that type I IFN signaling is essential for cognitive impairment in AD, impacting the neuroinflammatory network and contributing to neuropathogenic processes.

“recent studies that demonstrate how type I IFN signaling is essential for cognitive impairment in AD,78 not only impacting the neuroinflammatory network of the disease but also contributing to neuropathogenic processes.”

• cites [78] Roy E.R. Chiu G. Li S. Propson N.E. Kanchi R. Wang B. Coarfa C. Zheng H. Cao W. Concerted type I interferon signaling in microglia and neural cells promotes memory impairment associated with amyloid β plaques Immunity 55 2022 879 894.e6 10.1016/j.immuni.2022.03.018 35443157 PMC9109419 sourcePartly supported

  The Results section ('IFN-I blockade rescues memory and synaptic deficits'; page not provided) reports restored memory in an amyloid-plaque mouse model after IFN-I receptor blockade. Other Results passages link IFN-I signaling to neuroinflammation and neuritic pathology, but the human AD evidence is observational; the paper does not demonstrate that IFN-I signaling is essential for cognitive impairment in people with AD. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [75] Roy E.R. Wang B. Wan Y.W. Chiu G. Cole A. Yin Z. Propson N.E. Xu Y. Jankowsky J.L. Liu Z. Type I interferon response drives neuroinflammation and synapse loss in Alzheimer disease J. Clin. Investig. 130 2020 1912 1930 10.1172/JCI133737 31917687 PMC7108898 sourcePartly supported

  The Introduction reports that IFN receptor blockade reduced microgliosis and synapse loss in AD mouse models, and identifies IFN as a contributor to AD neuroinflammation and neuropathology. The section “IFN pathway activation is manifested in human AD” reports a correlation with cognitive decline, but the paper does not demonstrate that type I IFN signaling is essential for cognitive impairment in AD. Page numbers were not available in the indexed passages. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [79] Jin M. Xu R. Wang L. Alam M.M. Ma Z. Zhu S. Martini A.C. Jadali A. Bernabucci M. Xie P. Type-I-interferon signaling drives microglial dysfunction and senescence in human iPSC models of Down syndrome and Alzheimer's disease Cell Stem Cell 29 2022 1135 1153.e8 10.1016/j.stem.2022.06.007 35803230 PMC9345168 sourcePartly supported

  The Discussion (page unavailable) links elevated type I IFN signaling to microglial activation, synaptic loss and senescence in AD-related models. The paper's own experiments concern Down syndrome microglia and pathological tau; they do not demonstrate that IFN signaling is essential for cognitive impairment in AD. Its suggestion that targeting IFNARs might slow AD progression is more tentative than the citing sentence. (LLM, conf=0.86)

  Experimental — accuracy not yet measured

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

Aβ plaques act as a driver of AD pathology and their accumulation initiates a complex multicellular neurodegenerative process.

“since it is known that the Aβ plaques act as a driver of AD pathology63 and the accumulation Aβ plaques in the brain initiates a complex multicellular neurodegenerative process.”

• cites [63] Karran E. Mercken M. De Strooper B. The amyloid cascade hypothesis for Alzheimer's disease: an appraisal for the development of therapeutics Nat. Rev. Drug Discov. 10 2011 698 712 10.1038/nrd3505 21852788 sourceNot checked — no full text of the source
• cites [64] Sevigny J. Chiao P. Bussière T. Weinreb P.H. Williams L. Maier M. Dunstan R. Salloway S. Chen T. Ling Y. The antibody aducanumab reduces Aβ plaques in Alzheimer’s disease Nature 537 2016 50 56 10.1038/nature19323 27582220 sourceNot checked — no full text of the source
• cites [65] Long J.M. Holtzman D.M. Alzheimer Disease: An Update on Pathobiology and Treatment Strategies Cell 179 2019 312 339 10.1016/j.cell.2019.09.001 31564456 PMC6778042 sourceSupported
• cites [66] Schneider L. A resurrection of aducanumab for Alzheimer's disease Lancet Neurol. 19 2020 111 112 10.1016/S1474-4422(19)30480-6 31978357 sourceCould not verify

  The aducanumab trial discussion (article pp. 111–112) reports substantial plaque reduction but says the clinical effects were far less certain. It does not establish that Aβ plaques drive Alzheimer’s pathology or that their accumulation initiates a multicellular neurodegenerative process; searches for those causal claims found no supporting passage. (LLM, conf=0.72)

  Experimental — accuracy not yet measured

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

In a transgenic mouse model expressing human tau, cognitive impairment is ameliorated when STAT1 signaling is blocked.

“in a transgenic mouse model expressing human tau, cognitive impairment is ameliorated when STAT1 signaling is blocked.”

• cites [94] Li X.G. Hong X.Y. Wang Y.L. Zhang S.J. Zhang J.F. Li X.C. Liu Y.C. Sun D.S. Feng Q. Ye J.W. Tau accumulation triggers STAT1-dependent memory deficits by suppressing NMDA receptor expression EMBO Rep. 20 2019 e47202 10.15252/embr.201847202 PMC6549025 31085626 sourcePartly supported

  The Results (‘Downregulating STAT1 rescues hTau-induced memory and synaptic deficits,’ p. 19) report improved learning and memory after STAT1 knockdown in mice expressing human tau. But human tau was introduced by hippocampal AAV injection into STAT1-floxed mice; the cited rescue experiment was not conducted in a transgenic mouse model expressing human tau. (LLM, conf=0.87)

  Experimental — accuracy not yet measured

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

Another study revealed decreased neurogenesis in the subgranular zone of the hippocampus DG in 5xFAD mice, which plays an important role in cognitive dysfunction.

“Another study revealed decrease neurogenesis in the subgranular zone of the hippocampus DG in 5xFAD mice,91 which plays an important role in cognitive dysfunction.”

• cites [91] Zaletel I. Schwirtlich M. Perović M. Jovanović M. Stevanović M. Kanazir S. Puškaš N. Early Impairments of Hippocampal Neurogenesis in 5xFAD Mouse Model of Alzheimer's Disease Are Associated with Altered Expression of SOXB Transcription Factors J. Alzheimers Dis. 65 2018 963 976 10.3233/jad-180277 30103323 sourceNot checked — no full text of the source
• cites [92] Mu Y. Gage F.H. Adult hippocampal neurogenesis and its role in Alzheimer's disease Mol. Neurodegener. 6 2011 85 10.1186/1750-1326-6-85 22192775 PMC3261815 sourcePartly supported

  The “Neurogenesis deficits in AD mouse models” section (page unavailable) reports reduced dentate-gyrus neurogenesis in several AD mouse models, but does not identify 5xFAD mice among them. It reports a correlation with impaired learning in PS1M146V mice and explicitly says it remains unclear whether reduced neurogenesis causes the memory deficits. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

Classified as probably not a substantial claim.

People with DS are at greater risk for developing early-onset dementia caused by AD.

“People with DS are at greater risk for developing early-onset of dementia caused by AD.”

• cites [9] Lott I.T. Head E. Dementia in Down syndrome: unique insights for Alzheimer disease research Nat. Rev. Neurol. 15 2019 135 147 10.1038/s41582-018-0132-6 30733618 PMC8061428 sourceSupported
• cites [41] Wiseman F.K. Al-Janabi T. Hardy J. Karmiloff-Smith A. Nizetic D. Tybulewicz V.L.J. Fisher E.M.C. Strydom A. A genetic cause of Alzheimer disease: mechanistic insights from Down syndrome Nat. Rev. Neurosci. 16 2015 564 574 10.1038/nrn3983 26243569 PMC4678594 sourceSupported
• cites [76] McCarron M. McCallion P. Coppus A. Fortea J. Stemp S. Janicki M. Wtachman K. Supporting advanced dementia in people with Down syndrome and other intellectual disability: consensus statement of the International Summit on Intellectual Disability and Dementia J. Intellect. Disabil. Res. 62 2018 617 624 10.1111/jir.12500 29781149 sourceSupported

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

Inappropriate upregulation of type I IFN signaling and ISG expression in the CNS has been linked to several interferonopathies including Aicardi-Goutieres syndrome and USP18-deficiency in humans.

“Inappropriate upregulation of type I IFN signaling and ISG expression in the CNS have been linked to several interferonopathies including Aicardi-Goutieres syndrome and ubiquitin specific peptidase 18 (USP18)-deficiency in humans.”

• cites [80] Rodero M.P. Crow Y.J. Type I interferon–mediated monogenic autoinflammation: The type I interferonopathies, a conceptual overview J. Exp. Med. 213 2016 2527 2538 10.1084/jem.20161596 27821552 PMC5110029 sourcePartly supported

  The sections “Which diseases should be considered as type I interferonopathies?” and “Is it appropriate to use the term type I interferonopathies (II)?” link AGS and USP18 deficiency to enhanced interferon signaling, and report elevated cerebrospinal-fluid interferon activity in AGS. They do not establish upregulated ISG expression specifically in the CNS of humans with both conditions. No page numbers are available in our copy. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [81] Goldmann T. Zeller N. Raasch J. Kierdorf K. Frenzel K. Ketscher L. Basters A. Staszewski O. Brendecke S.M. Spiess A. USP18 lack in microglia causes destructive interferonopathy of the mouse brain EMBO J. 34 2015 1612 1629 10.15252/embj.201490791 25896511 PMC4475397 sourcePartly supported

  The Introduction identifies Aicardi–Goutières syndrome as an IFN-associated disorder affecting infants’ brains, and the results link Usp18 loss to prolonged IFN signaling and ISG expression in mouse microglia. The paper does not establish USP18 deficiency as a human interferonopathy: it describes human patients with ISG15 deficiency and reduced USP18 protein stability, which is a different condition. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [82] Hofer M.J. Campbell I.L. Type I interferon in neurological disease—The devil from within Cytokine Growth Factor Rev. 24 2013 257 267 10.1016/j.cytogfr.2013.03.006 23548179 sourceNot checked — no full text of the source
• cites [83] Crow Y.J. Stetson D.B. The type I interferonopathies: 10 years on Nat. Rev. Immunol. 22 2022 471 483 10.1038/s41577-021-00633-9 34671122 PMC8527296 sourcePartly supported

  The 'Phenotypes, expression and penetrance' section (page unavailable) identifies the CNS as the primary site of interferon production in AGS. 'Interferon receptor signalling' links USP18 deficiency to unrestrained type I interferon signalling and neurological involvement, and 'Definitions' explains that this signalling induces ISGs. The copy does not establish increased ISG expression specifically in the CNS for both human conditions. (LLM, conf=0.83)

  Experimental — accuracy not yet measured

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

Several commonly used cognitive tests employed here, including RAWM, rotarod, and the open field task, could be partially a function of non-neurological contributors to motor function that have been reported in Dp16 mice.

“Several commonly used cognitive tests employed here, including RAWM, rotarod, and the open field task, could be partially a function of non-neurological contributors to motor function that have been reported in Dp16 mice.44”

• cites [44] Goodliffe J.W. Olmos-Serrano J.L. Aziz N.M. Pennings J.L.A. Guedj F. Bianchi D.W. Haydar T.F. Absence of Prenatal Forebrain Defects in the Dp(16)1Yey/+ Mouse Model of Down Syndrome J. Neurosci. 36 2016 2926 2944 10.1523/JNEUROSCI.2513-15.2016 26961948 PMC4783496 sourcePartly supported

  The Motor assessment section (page not provided) reports reduced open-field locomotion, impaired hindlimb reflexes, and motor weakness in adult Dp16 mice. It does not identify non-neurological causes of those impairments or test whether they affect RAWM or rotarod performance; the proposed contribution to those tests remains an inference. (LLM, conf=0.83)

  Experimental — accuracy not yet measured

May combine two claims.

DS-AD mice show increased accumulation of activated microglia associated with Aβ plaques, with increased phagocytic activity.

“Our results demonstrate an increased accumulation of activated microglia associated with Aβ plaques in DS-AD mice, with increased phagocytic activity”

• cites [67] Keren-Shaul H. Spinrad A. Weiner A. Matcovitch-Natan O. Dvir-Szternfeld R. Ulland T.K. David E. Baruch K. Lara-Astaiso D. Toth B. A Unique Microglia Type Associated with Restricting Development of Alzheimer's Disease Cell 169 2017 1276 1290.e17 10.1016/j.cell.2017.05.018 28602351 sourcePartly supported

  The Introduction reports increased numbers of microglia containing intracellular Aβ particles and DAM markers in 5XFAD mice. The Results place phagocytic microglia near Aβ plaques. The paper studied 5XFAD mice, not DS-AD mice, so it does not establish the claim for the stated model. (LLM, conf=0.89)

  Experimental — accuracy not yet measured
• cites [95] Marlatt M.W. Bauer J. Aronica E. van Haastert E.S. Hoozemans J.J.M. Joels M. Lucassen P.J. Proliferation in the Alzheimer hippocampus is due to microglia, not astroglia, and occurs at sites of amyloid deposition Neural Plast. 2014 2014 693851 10.1155/2014/693851 PMC4157009 25215243 sourcePartly supported

  The Discussion (page unavailable) reports activated microglia proliferating around Aβ plaques in an AD mouse model, which supports the general plaque-association point. It does not report findings in DS-AD mice or increased phagocytic activity; its own study examined human hippocampal tissue. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

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

JAK inhibitors have been successfully used to treat alopecia areata, psoriatic arthritis, and other autoimmune skin conditions in individuals with DS.

“we have reported instances of successful use of JAK inhibitors to treat alopecia areata, psoriatic arthritis, and other autoimmune skin conditions in individuals with DS.”

• cites [96] Rachubinski A.L. Estrada B.E. Norris D. Dunnick C.A. Boldrick J.C. Espinosa J.M. Janus kinase inhibition in Down syndrome: 2 cases of therapeutic benefit for alopecia areata JAAD Case Rep. 5 2019 365 367 10.1016/j.jdcr.2019.02.007 31008170 PMC6453941 sourcePartly supported

  The Introduction and Case reports describe two individuals with Down syndrome whose alopecia areata improved with the JAK inhibitor tofacitinib. The Discussion mentions approval of tofacitinib for psoriatic arthritis and the prevalence of other autoimmune skin conditions in Down syndrome, but does not report successful treatment of those conditions in individuals with Down syndrome. (LLM, conf=0.90)

  Experimental — accuracy not yet measured
• cites [97] Pham A.T. Rachubinski A.L. Enriquez-Estrada B. Worek K. Griffith M. Espinosa J.M. JAK inhibition for treatment of psoriatic arthritis in Down syndrome Rheumatology 60 2021 e309 e311 10.1093/rheumatology/keab203 33630031 PMC8410001 sourcePartly supported

  The case report describes successful tofacitinib treatment of psoriatic arthritis in one person with Down syndrome; her psoriasis also largely cleared within six weeks (treatment account and Fig. 1). Our copy does not report treatment of alopecia areata or other autoimmune skin conditions beyond psoriasis, so it does not support the full list of conditions in the claim. (LLM, conf=0.90)

  Experimental — accuracy not yet measured
• cites [98] Rachubinski A.L. Wallace E. Gurnee E. Enriquez-Estrada B.A. Worek K.R. Smith K.P. Araya P. Waugh K.A. Granrath R.E. Britton E. JAK inhibition decreases the autoimmune burden in Down syndrome eLife 13 2024 RP99323 10.7554/eLife.99323 PMC11687933 39737640 sourceSupported

May combine two claims.

5xFAD-Dp16 mice showed delayed acquisition of cliff aversion, auditory startle reflex, and eye-opening developmental milestones, but not in surface righting or ear twitch.

“5xFAD-Dp16 mice showed delayed acquisition of cliff aversion, auditory startle reflex, and eye-opening developmental milestones, but not in surface righting or ear twitch (Figures 1D, S1D, and Data S1).”

May combine two claims.

5xFAD and 5xFAD-Dp16 mice present a higher proportion of DAM relative to WT mice, with Dp16 animals showing only a modest increase within the brain.

“Notably, we observed that 5xFAD and 5xFAD-Dp16 mice present a higher proportion of DAM (defined by Cst7, Myoc, Ccl6, Acta2, Cd74, Lyz2, Trem2, Vim, Ifi27l2a, and Cd52) relative to WT mice, with the Dp16 animals showing only a modest increase within the brain (Figure 3E and Data S9).”

May combine two claims.

DS-AD mice committed more working memory errors than their WT littermates, particularly males.

“However, when we quantified working memory errors (WME), the number of times a mouse re-entered an arm without a platform, we found that DS-AD committed more working memory errors than their WT littermates, particularly males (Figures 1J and S2F).”

May combine two claims.

Systemic treatment with a JAK inhibitor improved cognition and rescued gene expression changes in DS-AD animals.

“Finally, systemic treatment with a JAK inhibitor improved cognition and rescued gene expression changes in DS-AD animals, indicating that IFN may be a driver of pathophysiology in DS-AD that could be amenable to therapeutic intervention.”

• Also stated in: § Introduction · plain

  “Finally, we treated animals with the JAK inhibitor tofacitinib after establishment of neuropathology and found that it improved cognition and rescued gene expression changes in DS-AD animals.”

May combine two claims.

DS-AD mice showed an increase in total number of wrong arm entries relative to WT at both 7 and 9 months, and relative to 5xFAD at 7 months, with trends generally held for both sexes.

“When observed an increase in the total number of wrong arm entries for the DS-AD mice relative to the WT group at both 7 and 9 months, and relative to 5xFAD at 7 months, trends the generally held for both sexes (Figures 1H, 1I, and S2E).”

May combine two claims.

5xFAD-Dp16 mice presented significantly reduced weight compared to all other genotypes throughout the preweaning period, while Dp16 mice were significantly smaller than both WT and 5xFAD mice.

“Analysis of growth profiles indicated that 5xFAD-Dp16 mice presented significantly reduced weight compared to all other genotypes throughout the preweaning period, while Dp16 mice were significantly smaller than both wild-type (WT) and 5xFAD mice (Figures 1B and 1C).”

May combine two claims.

Male mice performed like the combined group, with 5xFAD animals exhibiting significantly more freezing than other genotypes at the end of day 1 and throughout day 2.

“When we broke these data out by sex, we found that the male mice performed like the combined group, with 5xFAD animals exhibiting significantly more freezing than other genotypes at the end of day 1 and throughout day 2 (Figure 2C).”

May combine two claims.

5xFAD mice trended toward greater latency to fall at 3 and 5 months of age, with significant increases at 7 and 9 months of age.

“In contrast, 5xFAD mice trended toward greater latency to fall at 3 and 5 months of age, with significant increases at 7 and 9 months of age (Figure 2A).”

May combine two claims.

DAM were mostly present in the hippocampus, cortex, thalamus, and hypothalamus in 5xFAD-Dp16 mice, while stressed cells were identified in the hippocampus, cortex, thalamus, hypothalamus, and fiber track.

“When we evaluated the spatial distribution of the DAM and the cells stressed by disease pathology, we found that DAM were mostly present in the hippocampus, cortex, thalamus, and hypothalamus in 5xFAD-Dp16 mice, while the stressed cells were identified in the hippocampus, cortex, thalamus, hypothalamus, and fiber track (Figures 3F and 3G).”

May combine two claims.

The combinatorial induction of ISGs was largely diminished by 9 months of age; however, certain genes such as Ifi44 in the hippocampus and Irf7 in the cortex remained moderately elevated in 5xFAD-Dp16 mice relative to the other genotypes.

“This combinatorial induction of ISGs was largely diminished by 9 months of age; however, certain genes such as Ifi44 in the hippocampus and Irf7 in the cortex remained moderately elevated in 5xFAD-Dp16 mice relative to the other genotypes (Figures 3B and S3B).”

May combine two claims.

On day 2, 5xFAD animals exhibited a high degree of freezing, and WT and 5xFAD-Dp16 were indistinguishable from one another with freezing rates between Dp16 and 5xFAD.

“The 5xFAD animals exhibited a high degree of freezing throughout the day 2 assessment and the WT and 5xFAD-Dp16 were indistinguishable from one another with freezing rates between Dp16 and 5xFAD (Figure 2B), showing how 5xFAD-Dp16 improved associative learning and memory compared to Dp16 and 5xFAD.”

May combine two claims.

Female animals showed similar, albeit insignificant at times, trends, driven by 5xFAD animals exhibiting lower rates of freezing than their male counterparts at the end of day 1 and across day 2.

“Female animals showed similar, albeit insignificant at times, trends, driven by 5xFAD animals exhibiting lower rates of freezing than their male counterparts at the end of day 1 and across day 2 (Figure 2D).”

May combine two claims.

GSEA identified significantly elevated IFN and inflammatory signaling as a common feature across DS, AD, and DS-AD models compared to WT mice in both brain regions at different time points, with greater normalized enrichment scores at 9 months compared to 5 for many gene sets.

“Gene set enrichment analysis (GSEA) of Hallmark Gene Sets identified significantly elevated IFN and inflammatory signaling as a common feature across DS, AD, and DS-AD models compared to WT mice on both brain regions at the different time points), with greater normalized enrichments scores (NES) at 9 months of age compared to 5 for many gene sets (Figures 3A and S3A; Data S7).”

May combine two claims.

At 9 months of age, 5xFAD-Dp16 animals took longer to reach the platform than WT animals but were not significantly different from 5xFAD or Dp16 animals.

“At 9 months of age, the 5xFAD-Dp16 animals took longer to reach the platform than WT animals but were not significantly different from 5xFAD or Dp16 animals (Figures 1E and S2H).”

May combine two claims.

Both 5xFAD and 5xFAD-Dp16 animals weighed less only at 9 months of age than did their WT and Dp16 counterparts, indicating that changes in weight are not the cause for alterations in their performance on the accelerating rotarod.

“Of note, both 5xFAD and 5xFAD-Dp16 animals weighed less only at 9 months of age than did their WT and Dp16 counterparts (Figure S2G), indicating that changes in weight are not the cause for alterations in their performance on the accelerating rotarod, which may have masked differences in motor coordination, since lighter animals typically perform better on the rotarod.”

• AssumptionRests on an assumption: Lighter animals typically perform better on the rotarod.

May combine two claims.

5xFAD-Dp16 mice normalized the effects of the individual DS and AD genotypes and were not significantly different from any group at any age on the accelerating rotarod.

“Strikingly, the 5xFAD-Dp16 mice normalized the effects of the individual DS and AD genotypes and were not significantly different from any group at any age (Figure 2A).”

May combine two claims.

Spatial transcriptomic analysis revealed genome-wide alterations in DS-AD animals typified by upregulation of interferon signatures and elevated levels of disease-associated microglia with concomitant decreases in neurons.

“Spatial transcriptomic analysis revealed genome-wide alterations typified by upregulation of interferon (IFN) signatures and elevated levels of disease-associated microglia with concomitant decreases in neurons in DS-AD animals.”

• Also stated in: § Introduction · plain

  “Spatial transcriptomics and multispectral immunofluorescence revealed elevated levels of disease-associated microglia (DAM) in DS-AD animals relative to other genotypes with a concomitant reduction in neurons.”

May combine two claims.

At the 5-month RAWM training, the deficits observed in 5xFAD-Dp16 and Dp16 mice were abrogated, demonstrating that all genotypes were capable of learning, as evidenced by similar performance on day 2.

“Notably, at the additional 5-month training, the deficits observed in the 5xFAD-Dp16 and Dp16 mice were abrogated, demonstrating that all genotypes were capable of learning, as evidenced by the similar performance on day 2 (Figures 1E and 1F).”

May combine two claims.

At 7 months of age, both male and female 5xFAD-Dp16 mice exhibited increased time to platform compared to their littermate controls on day 1, and these deficits persisted into day 2.

“At 7 months of age, we observed that both male and female 5xFAD-Dp16 mice exhibited increased time to platform compared to their littermate controls on day 1 (Figures 1E–1G and S2B). Interestingly, these deficits persisted into day 2 (Figures 1E and S2B).”

May combine two claims.

5xFAD-Dp16 mice traveled further to reach the platform than their littermates at 7 months of age, but this difference was moderated by 9 months.

“Furthermore, 5xFAD-Dp16 mice traveled further to reach the platform than did their littermates at 7 months of age, but this difference was moderated by 9 months (Figure S1I).”

May combine two claims.

Median RAWM performance change values for 5xFAD and 5xFAD-Dp16 JAKi-treated groups were lower than their sham-treated counterparts, though not statistically significant.

“While not statistically significant, median values for 5xFAD and 5xFAD-Dp16 JAKi-treated groups were also lower than their sham-treated counterparts, also indicative of improved performance”

May combine two claims.

Many animals in the sham-treated group performed better in the RAWM after treatment, but no groups showed significant improvements.

“we observed that many animals in the sham-treated group performed better in the RAWM, as measured by total latency to reach platform, their second time in the maze after completion of treatment; however, no groups showed significant improvements”

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

Considerable inter-individual variation was observed in all four genotypes, with some animals performing worse.

“We also observed considerable inter-individual variation in all four genotypes, with some animals performing worse.”

May combine two claims.

Leading-edge genes from the oxidative phosphorylation gene set, including Atp5b, Mdh2, and Surf1, were strongly depleted in 5xFAD-Dp16 mice relative to WT littermates, and this effect was mitigated by JAKi treatment.

“Leading-edge genes from the oxidative phosphorylation gene set, including Atp5b, Mdh2, and Surf1, were once again strongly depleted in 5xFAD-Dp16 mice relative to WT littermates, and this effect was mitigated by JAKi treatment”

May combine two claims.

Increased dosage of HSA21 genes triplicated in Dp16 mice resulted in a significant decrease in Aβ plaque number in the cortex, with trends toward a decrease in most other brain regions examined.

“We found that increased dosage of HSA21 genes triplicated in Dp16 mice resulted in a significant decrease in Aβ plaque number in the cortex, with trends toward a decrease in most other brain regions examined”

• Also stated in: § Discussion · plain

  “we found decreased Aβ levels in the cortex, with trends toward decreased levels throughout the brain.”

May combine two claims.

JAK inhibition improves cognition and rescues alterations in gene expression associated with neuroinflammation and AD pathology.

“We also report that JAK inhibition improves cognition and rescues alterations in gene expression associated with neuroinflammation and AD pathology.”

May combine two claims.

This mouse model of DS-AD exhibits global transcriptomic changes, including exacerbated inflammatory signaling relative to either the DS or AD model alone.

“This mouse model of DS-AD exhibits global transcriptomic changes, including exacerbated inflammatory signaling relative to either the DS or AD model alone.”

May combine two claims.

Nearly 20% of all microglia had detectable Aβ in both 5xFAD and 5xFAD-Dp16 groups, a substantial increase from WT and Dp16.

“We found that nearly 20% of all microglia had detectable Aβ in both the 5xFAD and 5xFAD-Dp16 groups, a substantial increase from WT and Dp16, which do not express pathogenic Aβ”

May combine two claims.

Frequencies of activated microglia expressing CD11c and CX3CR1 were similar in WT and Dp16 animals, with increased frequencies in 5xFAD and Dp16-5xFAD.

“Assessment of activation marker expression on activated microglia, including CD11c and CX3CR1 revealed similar frequencies of cells expressing these markers among activated microglia in WT and Dp16 animals with increased frequencies in 5xFAD and Dp16-5xFAD”

May combine two claims.

5xFAD-Dp16 mice show age-associated decline in locomotion and impairment in spatial learning and memory compared with their littermate controls.

“5xFAD-Dp16 mice show age-associated decline in locomotion and impairment in spatial learning and memory compared with their littermate controls”

May combine two claims.

DS-AD mice present decreased neuronal cell density in hippocampus, cortex, and cerebellum compared with littermate controls at 9 months of age, with elevated microglial density, but no significant differences in astrocyte density.

“Our findings indicate that DS-AD mice present a decreased neuronal cell density in hippocampus, cortex, and cerebellum compared with their littermate controls at 9 months of age, with elevated microglial density, but no significant differences in the density of astrocytes regardless of differences among the AD models analyzed.”

May combine two claims.

In the JAKi-treated group, 5xFAD-Dp16 animals performed significantly better in the RAWM task, with shorter time to platform observed for all animals in this cohort.

“In the JAKi-treated group, we found that the 5xFAD-Dp16 animals performed significantly better in the RAWM task, with shorter time to platform observed for all animals in this cohort”

May combine two claims.

There was a clear decrease in homeostatic microglia in DS, AD, and DS-AD animals relative to WT, and both AD and DS-AD had lower percentage of homeostatic microglia than Dp16 animals.

“we observed a clear decrease in homeostatic microglia DS, AD, and DS-AD, animals relative to WT (Figure 6E) and both the AD and DS-AD had lower percentage of homeostatic microglia than the Dp16 animals.”

May combine two claims.

Tofacitinib rescues molecular changes at the gene expression level and may improve cognition in Dp16-5xFAD mice.

“consistent with our results here that tofacitinib rescues molecular changes at the gene expression level and may improve cognition in Dp16-5xFAD mice.”

May combine two claims.

DS increased neuron loss in AD mice, which may exacerbate cognitive dysfunction compared to their littermate controls.

“These observations suggest that DS increased neuron loss in AD mice, which may exacerbate cognitive dysfunction compared to their”

May combine two claims.

IFN may be a driver of pathophysiology in DS-AD that could be amenable to therapeutic intervention.

“Finally, systemic treatment with a JAK inhibitor improved cognition and rescued gene expression changes in DS-AD animals, indicating that IFN may be a driver of pathophysiology in DS-AD that could be amenable to therapeutic intervention.”

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

The complete spatial transcriptomics dataset after quality control contained information on the expression of 19,090 unique genes in a total of 10,549 spots across all four slides, with an average of 20,000 reads and ∼5,000 genes per spot.

“The complete dataset after quality control (QC) contained information on the expression of 19,090 unique genes in a total of 10,549 spots, or tissue domains (TDs), across all four slides, with an average of 20,000 reads and ∼5,000 genes per spot (see STAR Methods).”

May combine two claims.

DS contributes to the neuroinflammatory network of AD, causing alterations in cellular states consistent with alterations in memory and cognitive decline that may be amenable to therapeutic intervention.

“Altogether, these results indicate that DS contributes to the neuroinflammatory network of AD, causing alterations in cellular states consistent with alterations in memory and cognitive decline that may be amenable to therapeutic intervention.”

May combine two claims.

Segmental duplication of genes syntenic to human HSA21 in Dp16 potentiates different neuroinflammatory processes across the lifespan that could contribute to neurodegeneration in AD, including dysregulation of inflammatory signaling, as well as decreased DNA repair, cellular proliferation, and oxidative phosphorylation.

“Overall, these findings reveal that segmental duplication of genes syntenic to human HSA21 in Dp16 potentiate different neuroinflammatory processes across the lifespan that could contribute to neurodegeneration in AD, including dysregulation of inflammatory signaling, as well as decreased DNA repair, cellular proliferation, and oxidative phosphorylation.”

Classified as probably not a substantial claim.

Substantial evidence supports a pivotal role for neuroinflammation and neuronal cell loss in cognitive dysfunction in DS and AD.

“Substantial evidence supports a pivotal role for neuroinflammation and neuronal cell loss in cognitive dysfunction in DS and AD.”

May combine two claims.

Triplication of HSA21 orthologous genes can alter neuropathology in AD mice, exacerbating decreased neuronal density, which could contribute to impaired spatial learning and memory in 5xFAD-Dp16 mice relative to AD or DS models.

“these data indicate that triplication of HSA21 orthologous genes can alter the neuropathology in AD mice, exacerbating a decreased neuronal density, which could contribute to the fact that 5xFAD-DP16 mice exhibit impaired spatial learning and memory relative to models of AD or DS.”

May combine two claims.

Increased dosage of HSA21-encoded genes in Dp16 mice impacts multiple processes that can promote or ameliorate AD pathogenesis in DS, which may be amenable to therapeutic or preventative intervention with currently available drugs.

“this study reveals that the increased dosage of HSA21-encoded genes in Dp16 mice impacts multiple processes that can promote or ameliorate the AD pathogenesis in DS that may be amenable to therapeutic or preventative intervention with currently available drugs.”

Classified as probably not a substantial claim.

The relationship between neuronal loss and Aβ deposits has been associated with dysregulation of type I IFN production.

“The relationship between neuronal loss and Aβ deposits has been associated with dysregulation of type I IFN production.”

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

5-month-old animals were randomized into treatment groups and underwent a pre-treatment RAWM assessment to establish a baseline.

“5-month-old animals were randomized into treatment groups and then underwent a pre-treatment RAWM assessment to establish a baseline.”

May combine two claims.

DS increased neuron loss in AD mice, which may exacerbate cognitive dysfunction compared to littermate controls.

“These observations suggest that DS increased neuron loss in AD mice, which may exacerbate cognitive dysfunction compared to their littermate controls.”

May combine two claims.

These data indicate a dysregulation or disruption in both microglia activation and phagocytosis activity in DS-AD mice.

“Taken together, these data indicate a dysregulation or disruption in both microglia activation and phagocytosis activity in DS-AD mice.”

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

The APP gene encoded on HSA21 has an essential role in DS-AD pathogenesis through increased levels of APP protein and Aβ in the brain.

“it is well-established that the APP gene encoded on HSA21 has an essential role in DS-AD pathogenesis through increased levels of APP protein and Aβ in the brain”

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

The sham-treated performance pattern is consistent with learning via repeated assessment.

“consistent with learning via repeated assessment”

May combine two claims.

These activated microglia could participate in dismantling and digestion of Aβ plaques involved in protective phagocytosis and influence and modulate neuronal function.

“suggesting that these cells could participate in the dismantling and digestion of Aβ plaques involved in protective phagocytosis, as well as influence and modulate the function of neurons.”

Classified as probably not a substantial claim.

Age-matched littermates were used as controls.

“Mice were randomly grouped by genotype, and age-matched littermates were used as controls.”

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

The sub-Mendelian survival of Dp16 animals to weaning affects cohort size.

“Additionally, Dp16 animals survive to weaning at sub-Mendelian ratios, which affects cohort size.”

• AssumptionRests on an assumption: Dp16 animals survive to weaning at sub-Mendelian ratios.

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

Pups were assessed in a pseudorandom order.

“Pups were assessed in a pseudorandom order by blinded investigators”

May combine two claims.

The spatial transcriptomics assay was performed in one mouse per cohort, reducing biological diversity and limiting the ability to comment on inter-individual variation.

“Although spatial transcriptomics is a powerful technology, we note that this assay was performed in one mouse per cohort, which reduces biological diversity and limits our ability to comment on inter-individual variation.”

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

Experimenters were blind to genotype during neonatal behavioral testing.

“All neonatal behavioral tests to measure different sensory and motor developmental parameters were performed between postnatal days (P) 3–21 at 8:00-10:00 h while experimenters were blind to genotype.”

• Also stated in: § Method details · plain

  “Pups were assessed in a pseudorandom order by blinded investigators”

Classified as probably not a substantial claim.

Five-month-old mice were randomized into treatment groups.

“5-month-old mice were randomized into treatment groups and treated with tofacitinib (JAKi) (15 mg/kg) or an equivalent volume of 0.5% methylcellulose vehicle once a day via oral gavage for 30 days.”

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

Differential gene expression was evaluated using DESeq2 with surrogate variables to remove unwanted sources of variation, including sex and batch.

“Differential gene expression (DEG) was evaluated using DESeq2 v1.28.1109 with surrogate variables, determined using the svaseq() function from the sva package (version 3.46.0), as covariates to remove unwanted sources of variation, including sex and batch.”

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

These efforts have led to the launch of clinical trials for autoimmune skin conditions in DS (NCT04246372) and Down syndrome regression disorder (NCT05662228).

“These efforts have led to the launch of clinical trials for autoimmune skin conditions in DS (NCT04246372) and Down syndrome regression disorder (NCT05662228).”

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

All molecular and cellular biology experiments were performed with validated reagents by trained personnel.

“All molecular and cellular biology experiments were performed with validated reagents by trained personnel.”

May combine two claims.

The spatial transcriptomics analysis could not ascribe gene changes to a particular cell type, detect fine-grained cellular heterogeneity, cellular interactions, and dynamic processes.

“Furthermore, we were not able to ascribe any gene changes to a particular cell type, detect fine-grained cellular heterogeneity, cellular interactions, and dynamic processes, in part because any given spot can contain multiple cells making it difficult to interpret spatially resolved gene expression accurately.”

• AssumptionRests on an assumption: Any given spot in spatial transcriptomics can contain multiple cells, making it difficult to interpret spatially resolved gene expression accurately.

May combine two claims.

Dp16 mice only triplicate about half of the protein-coding genes on HSA21 and as a segmental duplication rather than a freely segregating chromosome.

“Dp16 mice only triplicate about half of the protein-coding genes on HSA21 and even those existing as a segmental duplication rather than a freely segregating chromosome.”

• cites [42] Li Z. Yu T. Morishima M. Pao A. LaDuca J. Conroy J. Nowak N. Matsui S.I. Shiraishi I. Yu Y.E. Duplication of the entire 22.9 Mb human chromosome 21 syntenic region on mouse chromosome 16 causes cardiovascular and gastrointestinal abnormalities Hum. Mol. Genet. 16 2007 1359 1366 10.1093/hmg/ddm086 17412756 sourceNot checked — no full text of the source

May combine two claims.

Immunomodulatory strategies may be beneficial to those with AD as well as those with DS-AD.

“Taken together, these data indicate that immunomodulatory strategies may be beneficial to those with AD as well as those with DS-AD.”

May combine two claims.

IFN signaling and neuroinflammation are key aspects of DS-AD pathology.

“Our observations, as well as those of other groups, that IFN signaling and neuroinflammation are key aspects of DS-AD pathology”

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

All experiments used both age-matched male and female animals.

“All experiments used both age-matched male and female animals.”

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

At times, the authors were unable to utilize perfectly sex-balanced cohorts due to animal availability, particularly for JAK inhibitor experiments.

“At times, we were unable to utilize perfectly sex-balanced cohorts due to animal availability—particularly for our JAK inhibitor experiments.”

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

The 5xFAD mouse model is highly useful for studying amyloid-beta plaque formation and early-stage AD mechanisms, but it fails to model the full spectrum of AD pathology, lacking tauopathy and genetic diversity.

“the 5xFAD mouse model is highly useful for studying amyloid-beta plaque formation and early-stage AD mechanisms, but it has fails to model the full spectrum of AD pathology, lacking tauopathy and genetic diversity, for example.”

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

Mice were randomly assigned to experimental groups.

“Mice were randomly grouped by genotype, and age-matched littermates were used as controls.”

• Also stated in: § Experimental model and study particpant details · plain

  “In all cases, models of DS-AD and their littermate controls were randomly assigned to experimental groups.”