The DOI matches its Crossref record; 49 of the 49 references it cites were found in a registry or an index; 49 of the 67 sources its claims cite were checked for support.
A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system
Open accessAbstract
Sustained silencing of gene expression throughout the brain using small interfering RNAs (siRNAs) has not been achieved. Here we describe an siRNA architecture, divalent siRNA (di-siRNA), that supports potent, sustained gene silencing in the central nervous system (CNS) of mice and nonhuman primates following a single injection into the cerebrospinal fluid. Di-siRNAs are composed of two fully chemically modified, phosphorothioate-containing siRNAs connected by a linker. In mice, di-siRNAs induced the potent silencing of huntingtin, the causative gene in Huntington’s disease, reducing messenger RNA and protein throughout the brain. Silencing persisted for at least 6 months, with the degree of gene silencing correlating to levels of guide strand tissue accumulation. In cynomolgus macaques, a bolus injection of di-siRNA showed substantial distribution and robust silencing throughout the brain and spinal cord without detectable toxicity and with minimal off-target effects. This siRNA design may enable RNA interference-based gene silencing in the CNS for the treatment of neurological disorders. A divalent siRNA architecture enables sustained silencing of gene expression in deep regions of the brain.
Overview
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Written from the paper’s full text.
TL;DR
A divalent siRNA scaffold (Di-siRNA) composed of two fully chemically modified, phosphorothioate-containing siRNAs linked by tetra-ethylene glycol supports broad CNS distribution and sustained gene silencing after a single CSF injection. In mice and non-human primates, Di-siRNA targeting huntingtin produced potent, widespread HTT silencing with minimal detectable toxicity or off-target effects.
Key findings
- In mice, a single ICV injection of 475 µg Di-siRNAHTT silenced HTT protein below detection throughout the brain; silencing was greater for protein (>99%) than mRNA (~70%), and >80% protein silencing persisted at four months, with effects exceeding six months in some regions.
- Guide strand accumulation declined slowly: 2–7 µg/g at one month, 0.8–2.5 µg/g at four months, and 0.2–1.8 µg/g at six months; estimated protein silencing IC50 was ~0.5 µg/g and IC90 ~2 µg/g.
- In Cynomolgus macaques, a single 25 mg ICV dose yielded 1–9 µg/g guide strand at one month and potent HTT silencing: >90% in cortex, >80% in hippocampus, ~50–85% in caudate, and ~40–70% in putamen; spinal cord accumulation was 4–7 µg/g with significant HTT mRNA silencing.
- Safety assessments in mice and NHPs showed no detectable toxicity: no DARPP32 loss, only minor Iba-1 changes (<1.5-fold), transient Gfap activation at one month in high-dose mice, no MRI or blood chemistry changes in NHPs, and RNA-seq found 52 differentially expressed genes at 1% FDR, with only two potential off-target genes (APOLD1 ~40% down, ANLN ~20% down).
Methods
- Di-siRNAs were synthesized as two fully 2′-F/2′-OMe-modified asymmetric siRNAs with ~40% phosphorothioate content, linked at their 3′ ends through a tetra-ethylene glycol linker; guide strand concentration defined dosing.
- Mice (FVB/NJ or BACHD-ΔN17 females) received intra-striatal or ICV injections; Cynomolgus macaques received a single 25 mg ICV infusion via MRI/CT-guided cannula.
- Guide strand accumulation was quantified by PNA hybridization/HPLC; mRNA by Quantigene, protein by western blot/WES, distribution by fluorescence microscopy, and transcriptome effects by RNA-seq with DESeq2 and gene ontology analysis.
Limitations
- The paper states that the mechanism of phosphorothioate-mediated uptake and retention is not fully understood, and it is unclear whether the minimal off-target effects are specific to CNS regions, NHPs, or these compounds because no other genome-wide NHP off-target data are available for comparison.
- The paper states that further investigations are required to detect changes in small RNA function, that it is unclear whether non-selective or SNP-selective HTT silencing is a better therapeutic strategy, and that further evaluation in established disease models is necessary.
- Evident from the text: NHP efficacy was assessed at one month after a single dose, so long-term durability in primates was projected from mouse accumulation data rather than directly measured; behavioral or functional outcomes were not reported.
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Claims the paper makes
79 Own result · 21 Own interpretation · 20 Partly supported · 8 No full text of the sources · 5 Supported · 3 Own method · 2 Mixed support · 2 Couldn’t confirm · 2 Sources not found · 2 No basis given · 1 Supported so far · 1 Not checked yet · accuracy not yet measured
Some cited sources support this claim and some don’t — read each source’s verdict below.
In the paper
“However, multiple injections of AAV are required due to the limited distribution achieved with a single injection.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Discussion
What the sources say
- Disputedcites [41] Evers, M. M. et al. AAV5-miHTT gene therapy demonstrates broad distribution and strong human mutant huntingtin lowering in a huntington’s disease minipig model. Mol. Ther. 26, 2163–2177 (2018). sourceExperimental — accuracy not yet measured
The Results section reports transduction in the thalamus, striatum and cortex after thalamic injection, and the Discussion describes favorable widespread brain distribution after thalamic injection. Although the paper finds that intrathecal injection reaches deep brain structures poorly and favors combined striatal and thalamic delivery for Huntington’s disease, it does not say that AAV generally requires multiple injections because a single injection has limited distribution. Page numbers are unavailable in our copy. (LLM, conf=0.84)
Checked by a reasoning model — may be wrong.
- Disputedcites [43] Pfister, E. L. et al. Artificial miRNAs reduce human mutant huntingtin throughout the striatum in a transgenic sheep model of Huntington’s disease. Hum. Gene. Ther. 29, 663–673 (2018). sourceExperimental — accuracy not yet measured
The Results (page unavailable) report that vector genomes were widely distributed in the neostriatum and that a single administration reduced mutant huntingtin mRNA in the caudate and putamen. Although the Discussion notes much lower vector levels in the cortex, the paper does not say multiple injections are required; its striatal findings run contrary to that claim. (LLM, conf=0.84)
Checked by a reasoning model — may be wrong.
- Partly supportedcites [44] Grondin, R. et al. Six-month partial suppression of huntingtin is well tolerated in the adult rhesus striatum. Brain 135, 1197–1209 (2012). sourceExperimental — accuracy not yet measured
The Stereotaxic surgical procedures section describes multiple AAV injections into the rhesus striatum, and Huntingtin suppression reports the extent of the effect around each injection site. The paper does not establish that a single injection has insufficient distribution or that multiple injections are required. (LLM, conf=0.84)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Disputed
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“However, they are retained near the brain injection site, even with continuous monthly administration4, 7.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Introduction
What the sources say
- Could not verifycites [4] Kordasiewicz, H. B. et al. Sustained therapeutic reversal of Huntington’s disease by transient repression of huntingtin synthesis. Neuron. 74, 1031–1044 (2012). sourceExperimental — accuracy not yet measured
The Results section on ASO distribution (page unavailable) reports that infused antisense oligonucleotides reached many brain regions, rather than remaining near the injection site. But the claim concerns conjugated siRNAs under continuous monthly administration; our copy does not report that treatment or its distribution. Searches for conjugated siRNAs and monthly administration found no passage addressing it. (LLM, conf=0.76)
- Partly supportedcites [7] Alterman, J. F. et al. Hydrophobically modified siRNAs silence huntingtin mRNA in primary neurons and mouse brain. Mol. Ther. Nucleic Acids 4, e266 (2015). sourceExperimental — accuracy not yet measured
The Results section on mouse-brain distribution (page not provided) reports a steep fluorescence gradient from the injection site 24 hours after a single injection, with no fluorescence visually detectable on the opposite side. This supports limited distribution after one injection, but not retention during continuous monthly administration; the Materials and methods section describes single injections, not a monthly regimen. (LLM, conf=0.88)
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Could not verify
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“When fully chemically-stabilized siRNAs are conjugated to hydrophobic ligands like cholesterol7, docosahexaenoic acid (DHA)8, or DHA with a phosphocholine head group10, they are successfully internalized by brain cells11.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Introduction
What the sources say
- Supportedcites [7] Alterman, J. F. et al. Hydrophobically modified siRNAs silence huntingtin mRNA in primary neurons and mouse brain. Mol. Ther. Nucleic Acids 4, e266 (2015). source
The Results section reports that cholesterol-conjugated hsiRNAs were internalized by primary cortical neurons. In the mouse-brain distribution results, the authors also observed internalization in cell bodies, including NeuN-positive neurons, after intrastriatal injection. The citing sentence uses this source for brain-cell internalization; its DHA examples carry separate citations. (LLM, conf=0.92)
- Partly supportedcites [8] Nikan, M. et al. Docosahexaenoic acid conjugation enhances distribution and safety of siRNA upon local administration in mouse brain. Mol. Ther. Nucleic Acids 5, e344 (2016). sourceExperimental — accuracy not yet measured
The Results section (page not provided) reports that cholesterol-conjugated siRNA is internalized by neurons and, to a lesser extent, astrocytes; it also describes neuronal internalization of DHA-conjugated siRNA. Our copy does not report brain-cell internalization of siRNA conjugated to DHA with a phosphocholine head group, so it does not support that example. (LLM, conf=0.87)
- Supportedcites [10] Nikan, M. et al. Synthesis and evaluation of parenchymal retention and efficacy of a metabolically stable O-Phosphocholine-N-docosahexaenoyl-l-serine siRNA conjugate in mouse brain. Bioconjug. Chem. 28, 1758–1766 (2017). source
In Results, under “PC-DHA-hsiRNA Exhibits Intracellular Uptake and Enhanced Huntingtin mRNA Silencing In Vitro” (page unavailable), the paper reports PC-DHA–siRNA in the cytoplasm of mouse cortical neurons and gene silencing after passive delivery of both PC-DHA– and DHA-conjugated siRNAs. This supports the cellular-internalization point for which this citation is attached; the ligand examples have separate citations in the citing sentence. (LLM, conf=0.90)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“As full chemical modification of siRNAs is essential for conjugate-mediated delivery16, we used fully chemically modified asymmetric siRNAs that have a 20-base guide strand and 15-base passenger strand.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Structure and synthesis of Divalent siRNAs
What the sources say
- Partly supportedcites [16] Hassler, M. R. et al. Comparison of partially and fully chemically-modified siRNA in conjugate-mediated delivery in vivo. Nucleic Acids Res. 46, 2185–2196 (2018). sourceExperimental — accuracy not yet measured
The Introduction (page unavailable) says full chemical stabilization is preferred for in vivo applications, not essential for conjugate-mediated delivery. It also describes marginal efficacy with conjugates tested using naked or partially modified siRNAs, so the citing sentence overstates the paper's conclusion. (LLM, conf=0.88)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Partly supported
The cited sources that could be checked couldn’t confirm or dispute this claim.
In the paper
“Di-siRNAHTT is perfectly complementary to both human HTT and mouse Htt genes7.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA silences wild type and mutant HTT protein with similar efficiency
What the sources say
- Could not verifycites [7] Alterman, J. F. et al. Hydrophobically modified siRNAs silence huntingtin mRNA in primary neurons and mouse brain. Mol. Ther. Nucleic Acids 4, e266 (2015). sourceExperimental — accuracy not yet measured
The Materials and methods describe hsiRNAs designed against human huntingtin, and the Results report that HTT10150 silences mouse Htt. Neither section identifies Di-siRNAHTT or states that it is perfectly complementary to both human and mouse targets (searched: Di-siRNAHTT, perfect complementarity, cross-species sequence matching). (LLM, conf=0.76)
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Could not verify
Every source the paper cites for this claim was checked and supports it.
In the paper
“The extent of HTT protein silencing was always greater than Htt mRNA (> 99% vs ~70%) (Fig. 2c,d) because a fraction of Htt mRNA localizes to the nucleus, making it more resistant to RNAi-based silencing29.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > The efficacy of high-dose Di-siRNA exceeds six months
What the sources say
- Supportedcites [29] Didiot, M. C. et al. Nuclear localization of huntingtin mRNA Is specific to cells of neuronal origin. Cell. Rep. 24, 2553–2560 e2555 (2018). source
The Results section, “Nuclear Htt mRNA Resists Silencing by Both ASOs and siRNAs” (page unavailable), reports that siRNAs reduced cytoplasmic Htt mRNA foci but not nuclear foci. This supports the cited explanation that nuclear localization makes a fraction of Htt mRNA more resistant to RNAi-based silencing. The >99% and ~70% figures are presented as the citing paper’s own results, not as figures attributed to this source. (LLM, conf=0.93)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“This HD model contains wild type mouse Htt and mutant human HTT (97 CAG repeats) with 17 N-terminal amino acids removed31.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA silences wild type and mutant HTT protein with similar efficiency
What the sources say
- Partly supportedcites [31] Gu, X. et al. N17 Modifies mutant huntingtin nuclear pathogenesis and severity of disease in HD BAC transgenic mice. Neuron 85, 726–741 (2015). sourceExperimental — accuracy not yet measured
The Introduction and Results describe BAC transgenic mice expressing human mutant HTT with 97Q on a mouse background. But the Results specify deletion of residues 2–16—15 amino acids within the N17 domain—not removal of all 17 N-terminal amino acids. (LLM, conf=0.90)
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Partly supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“To assess neuronal viability, we measured DARPP32 protein expression, an established marker for medium spiny neurons in the striatum7.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA are safe and well-tolerated in mice
What the sources say
- Partly supportedcites [7] Alterman, J. F. et al. Hydrophobically modified siRNAs silence huntingtin mRNA in primary neurons and mouse brain. Mol. Ther. Nucleic Acids 4, e266 (2015). sourceExperimental — accuracy not yet measured
The Results section (page unavailable) calls DARPP-32 “an established marker for striatal neuron viability,” and Materials and methods describes counting DARPP-32-positive neurons in the striatum. Our copy does not identify those neurons specifically as medium spiny neurons, so that part of the claim is not supported. (LLM, conf=0.84)
boostedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Partly supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Recently, we identified functional siRNA sequences targeting Apolipoprotein E (ApoE), implicated in several neurodegenerative diseases, including Alzheimer’s disease and Amyotrophic Lateral Sclerosis26–28 (Ferguson et al., manuscript in preparation).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA can be reprogrammed to silence multiple genes in the CNS
What the sources say
- Partly supportedcites [26] Liu, C. C., Liu, C. C., Kanekiyo, T., Xu, H. & Bu, G. Apolipoprotein E and Alzheimer disease: risk, mechanisms and therapy. Nat. Rev. Neurol. 9, 106–118 (2013). sourceExperimental — accuracy not yet measured
The Introduction (page unavailable) identifies APOE ε4 as a risk factor for late-onset Alzheimer’s disease, and “APOE and other types of dementia” discusses associations with other disorders. That section says APOE genotypes do not seem to influence the risk of amyotrophic lateral sclerosis, so the ALS example is not supported. The siRNA identification is attributed to the citing authors’ own work, not to this source. (LLM, conf=0.88)
- Supportedcites [27] Mahley, R. W., Weisgraber, K. H. & Huang, Y. Apolipoprotein E4: a causative factor and therapeutic target in neuropathology, including Alzheimer’s disease. Proc. Natl Acad. Sci. USA 103, 5644–5651 (2006). source
The citation supports the disease-association clause, not the citing authors’ statement that they identified functional siRNA sequences. The “ApoE and Neuropathology” section identifies apoE4 as a major genetic risk factor for Alzheimer’s disease and associates it with amyotrophic lateral sclerosis and other neurological disorders. (LLM, conf=0.92)
- Not checked — no full text of the sourcecites [28] Zetterberg, H., Jacobsson, J., Rosengren, L., Blennow, K. & Andersen, P. M. Association of APOE with age at onset of sporadic amyotrophic lateral sclerosis. J. Neurol. Sci. 273, 67–69 (2008). source
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Partly supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Intracellular distribution followed a perinuclear localization pattern that is characteristic of oligonucleotides11.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes broadly with productive silencing after a bolus CSF injection
What the sources say
- Partly supportedcites [11] Ly, S. et al. Visualization of self-delivering hydrophobically modified siRNA cellular internalization. Nucleic Acids Res. 45, 15–25 (2017). sourceExperimental — accuracy not yet measured
The Results section ('sd-rxRNA quickly internalizes through endocytic pathways following membrane association'; page unavailable) reports vesicles carrying the studied oligonucleotide in the perinuclear space. It does not establish that this localization pattern is characteristic of oligonucleotides generally. (LLM, conf=0.85)
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Partly supported
- Probably not a substantial claim. 24
- It may state two separate claims as one. 43
Some cited sources support this claim and some don’t — read each source’s verdict below.
In the paper
“The most advanced CNS-active ASO scaffold utilizes a mixed backbone configuration with at least 70–80% PS content. This modification maintains efficacy and distribution with minimal risk of toxic phenotypes 13, 14 via mechanisms that are not fully understood15.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Introduction
What the sources say
- Disputedcites [13] Flierl, U. et al. Phosphorothioate backbone modifications of nucleotide-based drugs are potent platelet activators. J. Exp. Med. 212, 129–137 (2015). sourceExperimental — accuracy not yet measured
The Results and Discussion sections on PS backbone modification and therapeutic relevance report platelet activation by PS-modified oligonucleotides and warn that these effects should be assessed in clinical trials. That is contrary to the claim of minimal toxic risk. The paper does not evaluate a CNS-active scaffold with 70–80% PS content, so its findings do not establish the risk of that specific mixed backbone. (LLM, conf=0.76)
Checked by a reasoning model — may be wrong.
- Partly supportedcites [14] Sewing, S. et al. Assessing single-stranded oligonucleotide drug-induced effects in vitro reveals key risk factors for thrombocytopenia. PLoS ONE 12, e0187574 (2017). sourceExperimental — accuracy not yet measured
The Discussion (page not provided) reports that reducing PS content may reduce platelet activation and thrombocytopenia risk, and that LNA modifications improve binding to RNA targets. But the Methods describe the tested oligonucleotides as fully phosphorothioated; the paper does not establish a CNS-active mixed-backbone scaffold with 70–80% PS content or show maintained efficacy and distribution. (LLM, conf=0.88)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. It may state two separate claims as one.
- Disputed
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“PS modifications are also essential for clinically-advanced siRNA configurations1, 16.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Introduction
What the sources say
- Partly supportedcites [1] Khvorova, A. & Watts, J. K. The chemical evolution of oligonucleotide therapies of clinical utility. Nat. Biotechnol. 35, 238–248 (2017). sourceExperimental — accuracy not yet measured
In “Chemical evolution of siRNAs > Metabolic stabilization” (page unavailable), the paper says phosphorothioate modifications are incorporated into many leading clinical siRNA candidates and improve nuclease resistance and in-vivo accumulation. It does not say they are essential to clinically advanced siRNA configurations; “many” does not establish necessity. (LLM, conf=0.88)
- Partly supportedcites [16] Hassler, M. R. et al. Comparison of partially and fully chemically-modified siRNA in conjugate-mediated delivery in vivo. Nucleic Acids Res. 46, 2185–2196 (2018). sourceExperimental — accuracy not yet measured
The Results (page not specified) say phosphorothioate (PS) linkages were included in the tested siRNAs to improve stability and resistance to exonucleases. The Introduction (page not specified) says additional PS modifications can enhance long-term efficacy of conjugated siRNAs. Neither passage establishes that PS modifications are essential for clinically advanced siRNA configurations. (LLM, conf=0.85)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
- Partly supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“siRNAs are large, negatively-charged, double-stranded molecules that require formulation6 or chemical conjugation7–10 for delivery to tissues (especially CNS).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Introduction
What the sources say
- Partly supportedcites [6] Coelho, T. et al. Safety and efficacy of RNAi therapy for transthyretin amyloidosis. N. Engl. J. Med. 369, 819–829 (2013). sourceExperimental — accuracy not yet measured
Citation 6 is attached to formulation. The paper describes lipid-nanoparticle formulations that deliver siRNAs to hepatocytes, supporting that part of the sentence. But it says these systemically administered formulations do not penetrate the CNS, so it does not support the CNS qualifier. The provided copy gives no page number for the relevant passage. (LLM, conf=0.88)
- Supportedcites [7] Alterman, J. F. et al. Hydrophobically modified siRNAs silence huntingtin mRNA in primary neurons and mouse brain. Mol. Ther. Nucleic Acids 4, e266 (2015). source
The citation is attached to chemical conjugation as a delivery strategy. The Results section describes siRNA conjugated to cholesterol to promote cellular uptake, and the Introduction reports that a single injection of unformulated, modified siRNA silenced Htt mRNA in mouse brain. The paper therefore supports this example of chemical conjugation for CNS delivery. (LLM, conf=0.90)
- Supportedcites [8] Nikan, M. et al. Docosahexaenoic acid conjugation enhances distribution and safety of siRNA upon local administration in mouse brain. Mol. Ther. Nucleic Acids 5, e344 (2016). source
The citation is attached to chemical conjugation as a delivery strategy, particularly for the CNS. The Introduction describes the difficulty of delivering siRNA to the brain, and the Discussion reports that DHA conjugation improved siRNA distribution in mouse brain. The source supports that attributed point; the separate formulation citation is not assessed here. (LLM, conf=0.91)
- Supportedcites [9] Osborn, M. F. & Khvorova, A. Improving small interfering RNA delivery in vivo through lipid conjugation. Nucleic Acid Ther. 28, 128–136 (2018). source
The Introduction describes siRNAs as large, polyanionic molecules that cannot permeate intact cell membranes and identifies conjugation as a delivery strategy. It also reports delivery of cholesterol-conjugated siRNAs to brain tissue, supporting the CNS example. (LLM, conf=0.90)
- Supportedcites [10] Nikan, M. et al. Synthesis and evaluation of parenchymal retention and efficacy of a metabolically stable O-Phosphocholine-N-docosahexaenoyl-l-serine siRNA conjugate in mouse brain. Bioconjug. Chem. 28, 1758–1766 (2017). source
Citation 7–10 is attached to chemical conjugation, rather than to the separate description of siRNA size and charge or to formulation. The Introduction identifies direct chemical conjugation as a strategy for tissue delivery and specifically discusses conjugation for non-formulated delivery to the CNS. (LLM, conf=0.90)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Partly supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“IBA-1 is located within a major histocompatibility complex and increases as a result of microglial activation7.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA are safe and well-tolerated in mice
What the sources say
- Supportedcites [7] Alterman, J. F. et al. Hydrophobically modified siRNAs silence huntingtin mRNA in primary neurons and mouse brain. Mol. Ther. Nucleic Acids 4, e266 (2015). source
The References section identifies the iba1 gene as located in the major histocompatibility complex class III region. The Results section says IBA-1 is upregulated following brain injury and is used to distinguish resting from activated microglia. (LLM, conf=0.86)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
- Supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“However, increasing the PS content of individual siRNA duplexes to 80% can limit RNA-induced silencing complex (RISC) efficacy 17, 18 and increase toxicity19, 20.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Introduction
What the sources say
- Partly supportedcites [17] Behlke, M. A. Progress towards in vivo use of siRNAs. Mol. Ther. 13, 644–670 (2006). sourceExperimental — accuracy not yet measured
The Chemical modification section says extensively PS-modified siRNA duplexes show reduced potency and/or toxicity. It does not specify 80% PS content or establish that the reduced potency results from impaired RISC efficacy. (LLM, conf=0.88)
- Not checked — no full text of the sourcecites [18] Winkler, J., Stessl, M., Amartey, J. & Noe, C. R. Off-target effects related to the phosphorothioate modification of nucleic acids. Chem. Med. Chem. 5, 1344–1352 (2010). source
- Partly supportedcites [19] Amarzguioui, M., Holen, T., Babaie, E. & Prydz, H. Tolerance for mutations and chemical modifications in a siRNA. Nucl. Acids Res. 31, 589–595 (2003). sourceExperimental — accuracy not yet measured
The Chemical modification section reports about 70% cell death with the most extensively phosphorothioated siRNA, supporting the toxicity part. The Discussion says shorter phosphorothioate stretches were well tolerated; our copy does not specify 80% PS content or show that PS modification limits RISC efficacy. (LLM, conf=0.86)
- Not checked — no full text of the sourcecites [20] Harborth, J. et al. Sequence, chemical, and structural variation of small interfering RNAs and short hairpin RNAs and the effect on mammalian gene silencing. Antisense Nucl. Acid Drug Devel. 13, 83–105 (2003). source
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Partly supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“The 1C2 antibody detects polyQ expansions33; and thus, is specific to the mutant protein.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA silences wild type and mutant HTT protein with similar efficiency
What the sources say
- Partly supportedcites [33] Herndon, E. S. et al. Neuroanatomic profile of polyglutamine immunoreactivity in Huntington disease brains. J. Neuropathol. Exp. Neurol. 68, 250–261 (2009). sourceExperimental — accuracy not yet measured
The Introduction says 1C2 binds preferentially to long-glutamine-stretch-containing mutant huntingtin, supporting its use to detect polyQ expansions. It does not support specificity to the mutant protein: the antibody was raised against normal TATA-binding protein, and the Abstract reports 1C2 immunoreactivity in controls. (LLM, conf=0.88)
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Partly supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“To evaluate the impact of Di-siRNA injection on microglia activation and gliosis, we measured two well-established markers of immune stimulation, IBA-1 and GFAP.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA are safe and well-tolerated in mice
What the sources say
- Partly supportedcites [7] Alterman, J. F. et al. Hydrophobically modified siRNAs silence huntingtin mRNA in primary neurons and mouse brain. Mol. Ther. Nucleic Acids 4, e266 (2015). sourceExperimental — accuracy not yet measured
The Results section (page not provided) uses IBA-1-positive microglia to assess innate immune activation and says IBA-1 is upregulated after brain injury. The cited paper’s passages do not identify GFAP as a marker or use it to assess gliosis, so they support only the IBA-1 part of the claim. (LLM, conf=0.86)
- Partly supportedcites [30] Achuta, V. S. et al. Tissue plasminogen activator contributes to alterations of neuronal migration and activity-dependent responses in fragile X mice. J. Neurosci. 34, 1916–1923 (2014). sourceExperimental — accuracy not yet measured
The section on increased tPA expression identifies GFAP as an astrocytic marker, supporting its use to identify glial cells. Our copy does not identify GFAP as a marker of immune stimulation or discuss IBA-1; the claimed role of both markers in assessing immune stimulation is therefore not established by this source. No page number is available in the indexed copy. (LLM, conf=0.82)
boosted- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
- Partly supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“A single subcutaneous injection of trivalent GalNAc-conjugated siRNA can achieve efficacy for >12 months22, 2324.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Introduction
What the sources say
- Partly supportedcites [22] Fitzgerald, K. et al. A highly durable RNAi therapeutic inhibitor of PCSK9. N. Engl. J. Med. 376, 41–51 (2017). sourceExperimental — accuracy not yet measured
The Methods and Results describe a single subcutaneous dose of inclisiran, a triantennary GalNAc-conjugated siRNA, with reductions in PCSK9 and LDL cholesterol maintained at day 180. The paper reports follow-up only to 180 days and discusses potential dosing every 3 or 6 months; it does not establish efficacy beyond 12 months. (LLM, conf=0.90)
- Partly supportedcites [23] Ray, K. K. et al. Inclisiran in patients at high cardiovascular risk with elevated LDL cholesterol. N. Engl. J. Med. 376, 1430–1440 (2017). sourceExperimental — accuracy not yet measured
The Methods describe a single subcutaneous dose of inclisiran, an siRNA, and the LDL Cholesterol Levels and Other Laboratory Measures section reports LDL-cholesterol reductions after a single dose through day 240. That is less than 12 months; our copy does not establish efficacy beyond 12 months or identify inclisiran as trivalent GalNAc-conjugated. (LLM, conf=0.89)
- Not checked — no full text of the sourcecites [24] Lee, Y. C. et al. Binding of synthetic oligosaccharides to the hepatic Gal/GalNAc lectin. Dependence on fine structural features. J. Biol. Chem. 258, 199–202 (1983). source
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
- Partly supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“GFAP is an intermediate filament protein and increases as a result of astrocyte proliferation30.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA are safe and well-tolerated in mice
What the sources say
- Partly supportedcites [30] Achuta, V. S. et al. Tissue plasminogen activator contributes to alterations of neuronal migration and activity-dependent responses in fragile X mice. J. Neurosci. 34, 1916–1923 (2014). sourceExperimental — accuracy not yet measured
The Materials and Methods section identifies GFAP as glial fibrillary acidic protein, and the section on increased tPA expression calls it an astrocytic marker. The paper does not describe GFAP as an intermediate filament protein or say that GFAP increases because of astrocyte proliferation; the reported increase is in tPA, not GFAP. No page numbers are available in our copy. (LLM, conf=0.86)
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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Probably not a substantial claim. It may state two separate claims as one.
- Partly supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Indeed, the most clinically-advanced siRNA conjugate is the multi-valent N-acetylgalactosamine (GalNAc)21, which drives delivery to and silencing in the liver.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Introduction
What the sources say
- Partly supportedcites [21] Nair, J. K. et al. Impact of enhanced metabolic stability on pharmacokinetics and pharmacodynamics of GalNAc-siRNA conjugates. Nucleic Acids Res. 45, 10969–10977 (2017). sourceExperimental — accuracy not yet measured
The Introduction (page unavailable) describes triantennary GalNAc as enabling efficient siRNA delivery to the liver, and the Results and Discussion report liver gene silencing. The Conclusion mentions programs progressing into clinical development, but the paper does not establish that GalNAc is the most clinically advanced siRNA conjugate compared with others. (LLM, conf=0.85)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
- Partly supported
The sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“To evaluate any potential preference for specific cell-types, we performed immunofluorescence on sections of Di-siRNA-treated NHP brains using neuron-specific (NeuN)34 and glial cell-specific (GFAP)35 antibodies.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes and silences in NHP brain
What the sources say
- Not checked — no full text of the sourcecites [34] Weyer, A. & Schilling, K. Developmental and cell type-specific expression of the neuronal marker NeuN in the murine cerebellum. J. Neurosci. Res. 73, 400–409 (2003). source
- Supportedcites [35] Takala, R. S. et al. Glial fibrillary acidic protein and ubiquitin C-Terminal hydrolase-L1 as outcome predictors in traumatic brain injury. World Neurosurg. 87, 8–20 (2016). source
The citation is attached to GFAP, not NeuN. The Introduction describes GFAP as a protein of the astroglial skeleton that represents glial injury, supporting its identification as a glial marker. The paper does not test an antibody's staining specificity. (LLM, conf=0.86)
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. It may state two separate claims as one.
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Since increasing the percentage of PS modifications in the siRNA, either uniformly (i.e. every other nucleotide linkage) or strategically, may interfere with RISC 17, 18 and reduce tolerability, a multi-valency approach may be preferable for fine-tuning siRNA uptake and toxicity.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Discussion
What the sources say
- Partly supportedcites [17] Behlke, M. A. Progress towards in vivo use of siRNAs. Mol. Ther. 13, 644–670 (2006). sourceExperimental — accuracy not yet measured
The Chemical modification section (page unavailable) says limited PS modification preserves siRNA potency, while extensive modification can reduce potency and/or cause toxicity. It does not say that PS modification interferes with RISC or assess an every-other-linkage pattern, so those specifics are unsupported. (LLM, conf=0.86)
- Not checked — no full text of the sourcecites [18] Winkler, J., Stessl, M., Amartey, J. & Noe, C. R. Off-target effects related to the phosphorothioate modification of nucleic acids. Chem. Med. Chem. 5, 1344–1352 (2010). source
hedgedconditional- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Partly supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“However, ASO delivery to deep brain structures is limited4, with no significant HTT silencing observed in NHP caudate after multiple injections42.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Discussion
What the sources say
- Partly supportedcites [4] Kordasiewicz, H. B. et al. Sustained therapeutic reversal of Huntington’s disease by transient repression of huntingtin synthesis. Neuron. 74, 1031–1044 (2012). sourceExperimental — accuracy not yet measured
The Results section (‘Suppression of huntingtin levels in the CNS after ASO infusion into non-human primates’; page not provided) reports that caudate huntingtin mRNA trended toward a 25% reduction, but the result was not statistically significant (p=0.23). The study used continuous infusion into the cerebrospinal fluid for 21 days, not multiple injections. The separate claim about limited delivery to deep brain structures is attached to citation 4, not this source. (LLM, conf=0.90)
- Not checked — no full text of the sourcecites [42] Southwell, A. L. et al. Huntingtin suppression restores cognitive function in a mouse model of Huntington’s disease. Sci. Transl. Med. 10, eaar3959 (2018). source
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Partly supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“siRNA off-target effects are a major concern in development of siRNA-based therapeutics38.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA modulates HTT expression with minimal off-target events
What the sources say
- Supportedcites [38] Janas, M. M. et al. Selection of GalNAc-conjugated siRNAs with limited off-target-driven rat hepatotoxicity. Nat. Commun. 9, 723 (2018). source
The Introduction identifies off-target effects as a major driver of hepatotoxicity in rodent GalNAc-siRNA toxicity screens. The Discussion says minimizing these effects could reduce attrition in toxicity screens and improve safety, supporting the claim that they are a significant concern in therapeutic development. (LLM, conf=0.90)
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
- Supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“In addition, we found no measurable changes in blood chemistry or cell counts (Supplementary Fig. 20), which is particularly important because thrombocytopenia (low platelet count) has been reported as a PS-mediated rare adverse event13, 14.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Absence of detectable adverse events.
What the sources say
- Partly supportedcites [13] Flierl, U. et al. Phosphorothioate backbone modifications of nucleotide-based drugs are potent platelet activators. J. Exp. Med. 212, 129–137 (2015). sourceExperimental — accuracy not yet measured
The Results and Discussion section, under “Relevance for PS-modified, nucleotide-based therapeutics” (page unavailable), identifies thrombocytopenia as a reported side effect of the PS-modified drug oblimersen. It does not say the event is rare or establish that the PS modification causes thrombocytopenia. (LLM, conf=0.85)
- Partly supportedcites [14] Sewing, S. et al. Assessing single-stranded oligonucleotide drug-induced effects in vitro reveals key risk factors for thrombocytopenia. PLoS ONE 12, e0187574 (2017). sourceExperimental — accuracy not yet measured
The Introduction (page unavailable) reports rare platelet-count reductions and cases of severe thrombocytopenia in trials of phosphorothioate oligonucleotides. But the Discussion (page unavailable) says the clinical mechanism remains unknown and may be multifactorial, so the paper does not establish that PS itself mediated those events. (LLM, conf=0.86)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
- Partly supported
The cited sources that could be checked couldn’t confirm or dispute this claim.
In the paper
“a non-selective strategy would allow for treatment of all HD patients with a single entity49”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Discussion
What the sources say
- Could not verifycites [49] Pfister, E. L. et al. Five siRNAs targeting three SNPs may provide therapy for three-quarters of Huntington’s disease patients. Curr. Biol. 19, 774–778 (2009). sourceExperimental — accuracy not yet measured
The Discussion (page unavailable) addresses allele-selective siRNAs: one could target nearly half the studied patients, while five could cover about three-quarters. A search for a non-selective, single-entity strategy found no passage assessing whether it could treat all HD patients. The paper's limited coverage estimates for selective siRNAs do not settle that different proposal. (LLM, conf=0.74)
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
- Could not verify
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“In Cynomolgus macaques, a bolus injection of Di-siRNA showed substantial distribution and robust silencing throughout the brain and spinal cord without detectable toxicity and with minimal off-target effects.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Abstract
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Silencing persisted for at least six months, with the degree of gene silencing correlating to guide strand tissue accumulation levels.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Abstract
plaincorrelational- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Guide strand accumulation in different brain regions ranged between 2–7 µg/g at one month, 0.8–2.5 µg/g at four months, and 0.2– 1.8 µg/g at six months, suggesting relatively slow clearance (Fig. 2b).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > The efficacy of high-dose Di-siRNA exceeds six months
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“At six months, the degree of silencing differed between brain regions: > 90% in hippocampus, ~50% in thalamus and striatum, and high variability in the cortex.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > The efficacy of high-dose Di-siRNA exceeds six months
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The higher dose resulted in approximately a two-fold maximum increase in guide strand tissue retention and a wider distribution compared to the lower dose (0.1 to 4 µg/g at 60 µg; 2–8 µg/g at 475 µg dose, Supplementary Fig. 6b).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes broadly with productive silencing after a bolus CSF injection
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“In the cortical regions, initial accumulation at one month was 3–4 µg/g and fell below the 0.5 µg/g threshold by six months, resulting in loss of silencing in some animals.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA retention correlates with mRNA and protein silencing
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Forty-eight hours after the injection, the mouse brain was uniformly pink to the naked eye (Fig. 1e), indicating broad distribution.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes broadly with productive silencing after a bolus CSF injection
hedgeddirectSingle case- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“We estimate the protein silencing IC50 value to be ~0.5 µg/g and the IC90 value to be ~2 µg/g of guide strand accumulation in tissue.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA retention correlates with mRNA and protein silencing
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“For genes differentially expressed at a 1% FDR, there were no significantly over-represented 6-mers and the HTT siRNA seed complement, AGAUUA, was present in the middle of the distribution (Fig. 6b).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA modulates HTT expression with minimal off-target events
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“There was no detectable difference between these scans, indicating that Di-siRNA injection did not cause a major inflammatory response (Fig. 5a).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Absence of detectable adverse events.
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Again, the level of guide strand accumulation was sufficient for potent HTT mRNA silencing in all regions tested (p < 0.01), with the exception of a single outlier in cervical white matter (Fig. 4e).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes and silences in NHP spinal cord
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“There was no major difference in silencing between the ipsilateral and contralateral sides of the brain, which is consistent with uniform distribution.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes and silences in NHP brain
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Slightly higher accumulation was seen in the lumbar compared to the cervical region.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes and silences in NHP spinal cord
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Fluorescent microscopy confirmed the visual distribution, with significant delivery to the cortex, caudate, and hippocampus.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes and silences in NHP brain
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“A single injection of Di-siRNAHTT showed potent down-regulation of both mutant and wild type HTT protein (Supplementary Fig. 15), with a silencing efficiency similar to that in wild type mice at four months post injection (Fig. 2d).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA silences wild type and mutant HTT protein with similar efficiency
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Upon sectioning of the brain, we observed uniform cortical distribution with evident delivery to deep brain structures, including the striatum (caudate and putamen) and hippocampus (Fig. 3c).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes and silences in NHP brain
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Forty-eight hours after unilateral injection, we observed uniform distribution throughout the non-human primate (NHP) brain, similar to mice.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes and silences in NHP brain
plainSingle case- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“We observed robust distribution to all spinal cord regions, with guide strand accumulation ranging from 4–7 µg/g (Fig. 4d).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes and silences in NHP spinal cord
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Animals woke up within 15 minutes after anesthesia was discontinued, with no observable adverse events.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes and silences in NHP brain
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“With a 1% FDR, only the “immune system processes” category was significantly enriched among differentially expressed genes, with 12 out of 576 expressed genes in this category showing differential expression.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA modulates HTT expression with minimal off-target events
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“We observed efficient distribution of Di-siRNA to both neurons and glial cells in the hippocampus and cortex, and observed co-localization of Di-siRNA (red) with both neurons (green) and glial cells (purple) (Fig. 3d).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes and silences in NHP brain
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Relaxing the differential expression threshold to 10% FDR, there were several overrepresented 6-mers, but none of them matched AGAUUA (Supplementary Fig. 21).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA modulates HTT expression with minimal off-target events
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The brain appeared visibly pink with no obvious difference in the degree of oligonucleotide distribution in injected vs non-injected sides (Fig. 3b).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes and silences in NHP brain
hedgedSingle case- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“For protein silencing (Fig. 3f, Supplementary Fig. 18 for raw westerns), we observed >90% silencing in cortex (p < 0.001), >80% silencing in hippocampus (p < 0.01), ~50–85% silencing in the caudate (p < 0.001), and ~40–70% silencing in putamen (p < 0.05).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes and silences in NHP brain
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“At one-month post injection (Fig. 3e), we observed 1–9 µg/g guide strand accumulation, with the highest accumulation detected in the cortex (9 µg/g), hippocampus (6 µg/g), and thalamus (6 µg/g), and the lowest accumulation in the caudate (2 µg/g) and putamen (1 µg/g).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes and silences in NHP brain
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Downregulated transcripts were slightly enriched for perfect complementarity to the guide strand seed region (P = 0.04) while no enrichment was observed in up-regulated genes (P = 0.59).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA modulates HTT expression with minimal off-target events
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Animals with a single treatment of Di-siRNA targeting HTT showed significant silencing of HTT with minimal transcriptome-wide changes.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Di-siRNA is delivered to most cortical neurons, resulting in non-selective, potent silencing of wild type and mutant HTT in the CNS, independent of brain size.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: unclear — It is unclear why the paper says it holds.
It may state two separate claims as one.
In the paper
“Broad distribution of ASOs, systemically and in the CNS, has been achieved primarily using phosphorothioate (PS) backbone modifications12.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Introduction
What the sources say
- Not checked — no full text of the sourcecites [12] Eckstein, F. Phosphorothioates, essential components of therapeutic oligonucleotides. Nucleic Acid Ther. 24, 374–387 (2014). source
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
In the paper
“To quantitatively evaluate guide strand accumulation, we used a PNA hybridization assay, which provides quantitative accumulation data and does not depend on the presence of a fluorescent label25.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes broadly with productive silencing after a bolus CSF injection
What the sources say
- Not matchedcites [25] Roehl, I., Schuster, M. & Seiffert, S. US Patent 20110201006 A1 (2011).
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
- Not matched
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“NTC had no impact on APOE expression, indicating that observed silencing is sequence specific and not caused by the Di-siRNA chemical scaffold.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA can be reprogrammed to silence multiple genes in the CNS
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“The underlying mechanism is not fully understood, but multiple cell surface receptors have been recently identified that may be involved in phosphorothioate-mediated oligonucleotide uptake15.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Discussion
What the sources say
- Not checked — no full text of the sourcecites [15] Crooke, S. T., Wang, S., Vickers, T. A., Shen, W. & Liang, X. H. Cellular uptake and trafficking of antisense oligonucleotides. Nat. Biotechnol. 35, 230–237 (2017). source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“In general, RNA-seq analyses of Di-siRNAHTT treated NHP brains reveal no major transcriptional changes (aside from HTT silencing) and minimal, if any, off-targeting activity.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA modulates HTT expression with minimal off-target events
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“We delivered Di-siRNAHTT via ICV injection, using Magnetic resonance Imaging (MRI) and Computerized Tomography (CT) to confirm needle placement in the lateral ventricle.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA distributes and silences in NHP brain
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. It may state two separate claims as one.
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“To determine whether there was any effect on neuronal viability, we examined two additional markers by western blot, NeuN36 and BF-137.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Absence of detectable adverse events.
What the sources say
- Not checked — no full text of the sourcecites [36] Lind, D., Franken, S., Kappler, J., Jankowski, J. & Schilling, K. Characterization of the neuronal marker NeuN as a multiply phosphorylated antigen with discrete subcellular localization. J. Neurosci. Res. 79, 295–302 (2005). source
- Not checked — no full text of the sourcecites [37] Dou, C. L., Li, S. & Lai, E. Dual role of brain factor-1 in regulating growth and patterning of the cerebral hemispheres. Cereb. Cortex 9, 543–550 (1999). source
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. It may state two separate claims as one.
In the paper
“HTT is involved in several cellular processes40, raising the potential for transcriptional changes downstream of HTT silencing (on-target vs off-target effects).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA modulates HTT expression with minimal off-target events
What the sources say
- Not checked — no full text of the sourcecites [40] Zuccato, C., Valenza, M. & Cattaneo, E. Molecular mechanisms and potential therapeutical targets in Huntington’s disease. Physiol. Rev. 90, 905–981 (2010). source
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
In the paper
“siRNA off-target effects are predominantly due to seed (position 2–7 of the guide strand) complementarity in the 3’ UTR of other targets39.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Results > Di-siRNA modulates HTT expression with minimal off-target events
What the sources say
- Not checked — no full text of the sourcecites [39] Birmingham, A. et al. 3’ UTR seed matches, but not overall identity, are associated with RNAi off-targets. Nat. Methods 3, 199–204 (2006). source
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
In the paper
“Linking of two ASOs via their 5’ ends resulted in better systemic efficacy compared to monomeric ASO variants46.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Discussion
What the sources say
- Not checked — no full text of the sourcecites [46] Bhagat, L. et al. Novel oligonucleotides containing two 3’-ends complementary to target mRNA show optimal gene-silencing activity. J. Med. Chem. 54, 3027–3036 (2011). source
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
In the paper
“Our findings are consistent with recent efforts to fine-tune ASO potency and toxicity profiles via optimization of PS content (Moazami et al., in review).”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Discussion
What the sources say
- Not matchedcites Moazami et al., in review
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
- Not matched
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Given the level of accumulation in cortex and hippocampus, silencing is expected to last 6–9 months in these regions, and as long as 2–4 months in the caudate and putamen.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Discussion
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The relationship between tissue accumulation and duration of silencing observed in mice holds in NHPs.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“The RNA-seq data from non-human primate samples have been deposited in GEO under accession code GSE130132, including processed transcriptome read counts.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Online Methods > Data availability
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“All experimental studies involving animals were approved by the University of Massachusetts Medical School Institutional Animal Care and Use Committee (IACUC Protocol #A-2411 and #A-2515) and performed according to the guidelines and regulations therein described.”
§ A divalent siRNA chemical scaffold for potent and sustained modulation of gene expression throughout the central nervous system > Online Methods > Animal Studies
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
The paper relies on this without support.
Sustained silencing of gene expression in deep regions of the brain using siRNAs has not been achieved.
“Sustained silencing of gene expression in deep regions of the brain using small interfering RNAs (siRNAs) has not been achieved.”
The paper relies on this without support.
An outstanding challenge is developing chemical architectures of oligonucleotides that permit robust, productive, and safe delivery to a particular target tissue.
“An outstanding challenge is developing chemical architectures of oligonucleotides that permit robust, productive, and safe delivery to a particular target tissue.”
The paper relies on this without support.
Rodent systemic distribution is generally predictive of large mammal distribution, but this is not necessarily the case for the CNS.
“Rodent systemic distribution is generally predictive of large mammal distribution. However, this is not necessarily the case for the CNS.”
The paper relies on this without support.
The siRNA-targeting region in the HTT sequence is equivalent in Cynomolgus macaque, mouse, and human.
“whose siRNA-targeting region in the HTT sequence is equivalent to that in mouse and human.”
The paper relies on this without support.
The chemical architecture of an siRNA determines pharmacokinetics and tissue delivery, but the base sequence of the oligonucleotide determines its target.
“The chemical architecture of an siRNA determines pharmacokinetics and tissue delivery, but the base sequence of the oligonucleotide determines its target.”
The paper relies on this without support.
Loss of DARPP32 indicates neuronal death.
“Loss of DARPP32 indicates neuronal death.”
The paper relies on this without support.
The cortex and striatum are the two brain regions primarily affected in HD.
“The cortex and striatum are the two brain regions primarily affected in HD.”
The paper relies on this without support.
Substantially lower accumulation is sufficient for target silencing.
“Substantially lower accumulation is sufficient for target silencing”
The paper relies on this without support.
The relationship between tissue accumulation and duration of silencing observed in mice holds in NHPs.
“Given the level of accumulation in cortex and hippocampus, silencing is expected to last 6–9 months in these regions, and as long as 2–4 months in the caudate and putamen.”
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
In the citing paper
“vinyl phosphonate was integrated at the 5′ antisense position, which is an important feature for maximal silencing in the CNS [8,22].”
From Elucidating brain transport pathways and cell type-dependent gene silencing of a durable lipid–siRNA conjugate administered into cerebrospinal fluid (2025) · cites this paper as [22]
Experimental — accuracy not yet measuredThe cited source says what the claim attributes to it.
In the citing paper
“One such compound is the divalent siRNA, a small (~25 kDa) and heavily phosphorothioated conjugate that exhibited potent Htt knockdown in mice out to 6 months following ICV delivery (40 nmol, ~2.67X the dose used here to assess L2-siRNA knockdown).31”
From Lipid-siRNA conjugate accesses a perivascular transport mechanism and achieves widespread and durable knockdown in the central nervous system (2024) · cites this paper as [31]
Citations
Cites
Apolipoprotein E and Alzheimer disease: risk, mechanisms and therapy
Liu, C.-C., Kanekiyo, T., Xu, H., & Bu, G. (2013) · Nature Reviews Neurology · doi:10.1038/nrneurol.2012.263 · Cited by 3,459
Nusinersen versus Sham Control in Infantile-Onset Spinal Muscular Atrophy
Finkel, R. S., Mercuri, E., Darras, B. T., Connolly, A. M., Kuntz, N. L., Kirschner, J., Chiriboga, C. A., Saito, K., Servais, L., Tizzano, E., et al. (2017) · New England Journal of Medicine · doi:10.1056/nejmoa1702752 · Cited by 2,337
The chemical evolution of oligonucleotide therapies of clinical utility
Khvorova, A., & Watts, J. K. (2017) · Nature Biotechnology · doi:10.1038/nbt.3765 · Cited by 1,216
Self-citationInclisiran in Patients at High Cardiovascular Risk with Elevated LDL Cholesterol
Ray, K. K., Landmesser, U., Leiter, L. A., Kallend, D., Dufour, R., Karakas, M., Hall, T., Troquay, R. P. T., Turner, T., Visseren, F. L. J., et al. (2017) · New England Journal of Medicine · doi:10.1056/nejmoa1615758 · Cited by 992
Safety and efficacy of RNAi therapy for transthyretin amyloidosis
Coelho, T., Adams, D., Silva, A., Lozeron, P., Hawkins, P. N., Mant, T., Perez, J., Chiesa, J., Warrington, S., Tranter, E., et al. (2013) · New England Journal of Medicine · doi:10.1056/nejmoa1208760 · Cited by 971
3′ UTR seed matches, but not overall identity, are associated with RNAi off-targets
Birmingham, A., Anderson, E. M., Reynolds, A., Ilsley-Tyree, D., Leake, D., Fedorov, Y., Baskerville, S., Maksimova, E., Robinson, K., Karpilow, J., et al. (2006) · Nature Methods · doi:10.1038/nmeth854 · Cited by 920
Self-citationMahley, R. W., Weisgraber, K. H., & Huang, Y. (2006) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0600549103 · Cited by 912
Molecular Mechanisms and Potential Therapeutical Targets in Huntington's Disease
Zuccato, C., Valenza, M., & Cattaneo, E. (2010) · Physiological Reviews · doi:10.1152/physrev.00041.2009 · Cited by 848
Kordasiewicz, H. B., Stanek, L. M., Wancewicz, E. V., Mazur, C., McAlonis, M. M., Pytel, K. A., Artates, J. W., Weiss, A., Cheng, S. H., Shihabuddin, L. S., et al. (2012) · Neuron · doi:10.1016/j.neuron.2012.05.009 · Cited by 770
A highly durable RNAi therapeutic inhibitor of PCSK9
Fitzgerald, K., White, S., Borodovsky, A., Bettencourt, B. R., Strahs, A., Clausen, V., Wijngaard, P., Horton, J. D., Taubel, J., Brooks, A., et al. (2017) · New England Journal of Medicine · doi:10.1056/nejmoa1609243 · Cited by 768
Cited by
Sorted by citations
Advances in oligonucleotide drug delivery
Roberts, T. C., Langer, R., & Wood, M. J. A. (2020) · Nature Reviews Drug Discovery · doi:10.1038/s41573-020-0075-7 · Cited by 2,121
Cytosolic delivery of nucleic acids: The case of ionizable lipid nanoparticles
Schlich, M., Palomba, R., Costabile, G., Mizrahy, S., Pannuzzo, M., Peer, D., & Decuzzi, P. (2021) · Bioengineering & Translational Medicine · doi:10.1002/btm2.10213 · Cited by 387
Tabrizi, S. J., Estevez‐Fraga, C., van Roon‐Mom, W., Flower, M. D., Scahill, R. I., Wild, E. J., Muñoz-Sanjuán, I., Sampaio, C., Rosser, A., & Leavitt, B. R. (2022) · The Lancet Neurology · doi:10.1016/s1474-4422(22)00121-1 · Cited by 354
RNAi-based drug design: considerations and future directions
Tang, Q., & Khvorova, A. (2024) · Nature Reviews Drug Discovery · doi:10.1038/s41573-024-00912-9 · Cited by 330
“Local administration of optimized siRNAs into the CNS, eye, lung and skin has shown robust efficacy 49,52,99,143,144 .”
InfluentialSelf-citationExpanding RNAi therapeutics to extrahepatic tissues with lipophilic conjugates
Brown, K. M., Nair, J. K., Janas, M. M., Anglero-Rodriguez, Y. I., Dang, L. T. H., Peng, H., Theile, C. S., Castellanos-Rizaldos, E., Brown, C., Foster, D., et al. (2022) · Nature Biotechnology · doi:10.1038/s41587-022-01334-x · Cited by 258
Metadata
- Authors
- Alterman, J. F., Godinho, B. M. D. C., Hassler, M. R., Ferguson, C. M., Echeverria, D., Sapp, E., Haraszti, R. A., Coles, A. H., Conroy, F., Miller, R., Roux, L., Yan, P., Knox, E. G., Turanov, A. A., King, R. M., Gernoux, G., Mueller, C., Gray-Edwards, H. L., Moser, R. P., Bishop, N. C., Jaber, S. M., Gounis, M. J., Sena-Esteves, M., Pai, A. A., DiFiglia, M., Aronin, N., & Khvorova, A.
- Affiliations
- University of Massachusetts Chan Medical School (US)
- Massachusetts General Hospital (US)
- Worcester Polytechnic Institute (US)
- Corresponding author
- Khvorova, Anastasia
- ORCID
- Alterman, Julia F.
- Godinho, Bruno M. D. C.
- Hassler, Matthew R.
- Ferguson, Chantal M.
- Echeverria, Dimas
- Sapp, Ellen
- Coles, Andrew H.
- Conroy, Faith
- Miller, Rachael
- Yan, Paul
- Knox, Emily G.
- King, Robert M.
- Gernoux, Gwladys
- Mueller, Christian
- Moser, Richard P.
- Jaber, Samer M.
- Gounis, Matthew J.
- Pai, Athma A.
- DiFiglia, Marian
- Khvorova, Anastasia
- Venue
- Nature Biotechnology
- Published
- 2019-08
- Volume
- 37
- Issue
- 8
- Pages
- 884-894
- ISSN
- 0733-222X (ISSN-L)
- 1087-0156
- 1546-1696
- PMC
- PMC6879195
- OpenAlex
- W2965851198
- Semantic Scholar
- b50dbba5e71ee3bcdb11e48c9d7bc44e58166827
- Cited by
- 227
- References
- 49
- Citations by year
- 2026: 35 · 2025: 37 · 2024: 42 · 2023: 32 · 2022: 33 · 2021: 24 · 2020: 21 · 2019: 3
- FWCI
- 5.80
- Type
- journal article
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Locations
- Nature Biotechnology (publishedVersion)
- PubMed (publishedVersion)
- Europe PMC (PubMed Central) (submittedVersion)
- PubMed Central (submittedVersion)
- The Journal of the American Medical Association (JAMA) Network (American Medical Association) (submittedVersion)
- Funders
- CHDI Foundation (A-6119)
- Alzheimer's Drug Discovery Foundation (20170101)
- Topics
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › RNA Interference and Gene Delivery
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › DNA and Nucleic Acid Chemistry
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Virus-based gene therapy research
- Keywords
- central nervous system, cerebrospinal fluid injection, chemically modified siRNA, Huntington's disease, non-human primates, neurological disorders
- MeSH terms
- Huntingtin Protein, Animals, Central Nervous System, Gene Expression Regulation, Mutation, RNA, Messenger, RNA, Small Interfering, Mice
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
A language model drew the claims from the paper on 2026-10-20, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).
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