Brown adipose tissue lipoprotein and glucose disposal is not determined by thermogenesis in uncoupling protein 1-deficient mice
Part of the results reproduced; minor but material deviations remained.
Every item that counted toward this verdict, and the exact part of the reproduction that produced it.
- ✓Any deviation was negligible
- 🔴Could not use the authors’ exact input data
- 🔴Reported values were only indirectly comparable
- 🟡A deviation arose in the data or preprocessing
- 🟡A deviation was attributed to the published material
- 🟡Reported values were not (fully) derivable from the shared data
- 🟡The central claim did not (fully) hold under reproduction
- 🟡Overall, the reproduction showed a material discrepancy
▸Reproduction agent’s raw note
DROP (non_pipeline). 'Brown adipose tissue lipoprotein and glucose disposal is not determined by thermogenesis in UCP1-deficient mice' (J Lipid Res 2020, PMC7604721, DOI 10.1194/jlr.RA119000455) is a Ucp1-/- vs WT mouse metabolic-physiology study with NO pipeline-derived computational results. Verified across PubMed + Europe PMC + PMC full text: no sequencing/omics of any kind, no public data accession (GEO/SRA/ENA/etc.), and no analysis code (GitHub/GitLab). Quantitative outputs are wet-lab radiolabeled-tracer counts, tolerance-test assays, qRT-PCR ddCt, Western blot, and Adiposoft/Fiji image quantification; statistics computed in Excel 2016 + GraphPad Prism 6.0 (GUI). Data availability is 'from the corresponding author upon reasonable request' (on-request). There is nothing computational to run, so no «our HPC» compute was spent. Contributing drop reasons: no_code, no_data_accession, data_restricted. This is an honest, well-evidenced drop, not a reproduction failure. NOT attempted: any wet-lab measurement (out of scope by HARD RULE 2). Dataset profiled in the same pass (data/dataset_profile.json): documents the absence of any public deposit.
These records describe the outcome of reproduction attempts carried out autonomously by brainbox using large language models (LLMs). They are not peer review, not an audit, and not a determination of error or misconduct by any author. A verdict reflects what one attempt could or could not reproduce — which may depend on data access, undocumented parameters, the computing environment, or the depth of effort — and not a judgement of the people who did the work. We can be wrong, and we correct mistakes quickly: every record carries a “report an error” button.
Assessment versions
Every reproduction run is kept as an immutable version — anchored to the data as it stood, with a tamper-evident chain hash. A rerun (e.g. after an author updates a deposit) adds a new version; the previous one stays on record.
-
v1 current initial assessmentassessed: 2026-06-18 ⛓ 71065bf7bf6a
✎ I am an author of this paper
Updated or fixed a deposit, or is there an erratum? Ask us to re-run the metrics. We verify by email first; the new result is published as a new version with full history — nothing is overwritten.
Provenance — full disclosure
When this reproduction was carried out, which methodology version was used, and by whom — so the record can be audited and checked independently.
- Reproduced
- 2026-06-18
- Rubric version
- v1.0
- Assessed by
-
🤖 AI curator · claude (ai-curator room) · v1.0 · run #1 2026-06-18no human curator yet
- Last updated
- 2026-08-05
Provisional, curator- or AI-assessed, and independently checkable. A reproduction outcome states what one attempt could reproduce — not a judgement of the authors.
Deep full-text extraction
Model: opusWhether cold-stimulated uptake of glucose or lipid tracers into brown adipose tissue is a good surrogate marker of UCP1-mediated thermogenesis, tested by comparing glucose and lipoprotein-derived fatty acid disposal in Ucp1−/− versus WT mice.
- ★ Glucose and lipoprotein handling by thermogenic adipose tissue does not necessarily reflect UCP1-dependent thermogenic activity finding
- ★ Lipid (lipoprotein-derived fatty acid) uptake into adipose tissue mirrors sympathetic activation rather than UCP1-dependent thermogenesis finding
- ★ Glucose uptake is increased in mildly cold-activated BAT of Ucp1−/− versus WT mice at subthermoneutral temperature finding
- ★ After full thermogenic activation (sustained cold or CL316,243), glucose disposal is lower in Ucp1−/− mice finding
- ★ Uptake of lipoprotein-derived fatty acids into chronically activated thermogenic tissues is substantially increased in UCP1-deficient mice finding
- ★ Increased lipid uptake is linked to higher sympathetic tone, indicated by elevated thermogenic gene levels in BAT and WAT of Ucp1−/− mice mechanism
| Assay | System | Perturbation | Readout | Platform |
|---|---|---|---|---|
| radiolabeled glucose tracer uptake | BAT of Ucp1−/− and WT mice | UCP1 knockout; mild cold (subthermoneutral) exposure | glucose uptake/disposal | — |
| radiolabeled glucose tracer uptake | BAT of Ucp1−/− and WT mice | sustained cold exposure or CL316,243 (β-3 adrenergic agonist) treatment | glucose disposal | — |
| radiolabeled lipoprotein/lipid tracer uptake | thermogenic adipose tissues (BAT and WAT) of Ucp1−/− and WT mice | chronic thermogenic activation (cold/CL316,243); UCP1 knockout | uptake of lipoprotein-derived fatty acids | — |
| thermogenic gene expression analysis | BAT and WAT of Ucp1−/− and WT mice | UCP1 knockout | levels of thermogenic genes (proxy for sympathetic tone) | — |
- ▲ Glucose uptake increased in mildly cold-activated BAT of Ucp1−/− vs WT mice at subthermoneutral temperature
- ▼ Lower glucose disposal in Ucp1−/− mice after full thermogenic activation by sustained cold or CL treatment
- ▲ Uptake of lipoprotein-derived fatty acids into chronically activated thermogenic adipose tissues substantially increased in UCP1-deficient mice
- ▲ Elevated thermogenic gene levels in BAT and WAT of Ucp1−/− mice indicating higher sympathetic tone
Statistical methods review
Model: sonnetA neutral, descriptive read of the statistical approach — what was done, and (for shared learning, not as criticism) what could also have been done.
This study employed radiolabeled tracer methodology to quantify glucose and lipoprotein-derived fatty acid uptake in brown and white adipose tissue of Ucp1−/− versus wild-type mice under subthermoneutral, sustained cold, and β-3-adrenergic agonist (CL316,243) conditions. The provided text consists of journal metadata and the abstract only; the methods and results sections containing statistical test names, n values, software, and reporting details are not present in the supplied excerpt. All factual statistical fields below therefore reflect what can and cannot be determined from the available text.
-
The study compares two genotypes (Ucp1−/− vs WT) across multiple treatment conditions using continuous tracer-uptake outcomes, a factorial structure↳ Could also: A two-way ANOVA (genotype × treatment) followed by a post-hoc test (e.g., Tukey HSD or Sidak correction) could be applied to the full factorial design — A two-way ANOVA explicitly estimates and tests the genotype-by-treatment interaction term, which is central to the paper's question of whether UCP1 status modulates the tracer-uptake response to thermogenic stimuli; separate pairwise tests do not directly quantify this interaction
-
Radiolabeled tracer uptake is reported across multiple tissues (BAT, WAT) and multiple conditions simultaneously, implying a family of comparisons↳ Could also: Family-wise error rate control (Bonferroni, Holm) or false discovery rate control (Benjamini-Hochberg) applied across the full set of tissue × condition comparisons — When many simultaneous comparisons are made across tissues and conditions, a multiplicity correction reduces the probability of spurious findings while preserving detection power for true effects
-
Multiple tissues from the same individual animal were likely assayed (BAT, inguinal WAT, epididymal WAT), producing within-animal correlated measurements↳ Could also: Mixed-effects models or repeated-measures ANOVA treating animal as a random effect, with tissue as a within-subject factor — Measurements from the same animal share unmeasured biological variation; modeling this correlation produces more accurate standard errors and prevents underestimation of variance relative to treating each tissue measurement as fully independent
-
Thermogenic gene expression differences between genotypes are used to infer sympathetic tone, a common endpoint in small-animal metabolic studies↳ Could also: Non-parametric alternatives (Mann-Whitney U, Kruskal-Wallis with Dunn post-hoc) for gene expression comparisons if group sizes are small (n < 6–8 per group) and normality cannot be assumed — Gene expression data in small rodent cohorts frequently departs from normality; non-parametric tests make no distributional assumption and maintain valid type-I error control under these conditions
-
Results in the abstract are described in directional qualitative terms (increased, lower, substantially increased) without explicit effect-size metrics↳ Could also: Reporting standardized effect sizes (Cohen's d for two-group comparisons, or eta-squared/partial eta-squared for ANOVA) alongside p-values — Effect sizes communicate the magnitude of differences independent of sample size, enabling readers to judge biological relevance and facilitating future power calculations and meta-analyses
What was reproduced
The exact results taken into scope, with each reported value next to the value our attempt produced.
Scope analysis — pmid-32769145
- Title: Brown adipose tissue lipoprotein and glucose disposal is not determined by thermogenesis in uncoupling protein 1-deficient mice
- Authors: Fischer AW, Behrens J, Sass F, Schlein C, Heine M, Pertzborn P, Scheja L, Heeren J.
- Journal: Journal of Lipid Research (2020) · DOI 10.1194/jlr.RA119000455 · PMCID PMC7604721
- Screened (UTC): 2026-06-18T11:13:49Z
Verdict: DROP — non_pipeline (no computational-pipeline-derived results)
What this study actually is
A mouse metabolic-physiology study (Heeren/Scheja lab, UKE Hamburg) comparing
glucose and lipoprotein-derived fatty-acid disposal in brown/white adipose tissue
of UCP1-deficient (Ucp1-/-) vs wild-type mice under different thermal/adrenergic
activation states. The quantitative readouts are wet-lab measurements, not
the output of any bioinformatic pipeline:
- in-vivo radiolabeled tracer uptake (³H/¹⁴C glucose & lipoprotein tracers) into tissues, counted by scintillation
- oral glucose / lipid tolerance tests, plasma lipid/glucose assays
- gene-expression by quantitative real-time PCR (ΔΔCt vs housekeeping genes)
- Western blotting (protein levels)
- histology with adipocyte size quantified via the Adiposoft plugin for Fiji/ImageJ (interactive GUI image analysis)
- indirect calorimetry / metabolic-cage parameters
Why nothing is in scope for pipeline reproduction
HARD RULE 2 of the brief limits reproduction to pipeline-derived computational results. This paper has none:
| Requirement for an eligible RU | Status here |
|---|---|
| Resolvable analysis code (own or third-party tool) | Absent — no GitHub/GitLab; analysis was Excel 2016 + GraphPad Prism 6.0 (GUI), Adiposoft/Fiji (GUI) |
| Public, obtainable data accession | Absent — no GEO/SRA/ENA/ArrayExpress/PRIDE/figshare/zenodo. Data availability: "available in the article and supplemental information, and from the corresponding author upon reasonable request" |
| A bioinformatic pipeline producing a reported result | Absent — no sequencing/omics of any kind (no RNA-seq, microarray, proteomics, mass-spec) |
There is no sequencing or omics modality, no deposited dataset, no scriptable pipeline, and no code repository. The statistics (Student's t-test / two-way ANOVA) were computed in Excel and GraphPad Prism on small wet-lab measurement tables that are not deposited. None of this is reproducible as a computational pipeline, and there is no public data to run anything against.
Data availability statement (verbatim)
"The data supporting this study are available in the article and the supplemental information, and are available from the corresponding author upon reasonable request."
Decision
- drop_reason:
non_pipeline(primary) - contributing:
no_code(no analysis code repository) andno_data_accession/ on-request data (data_restricted) — any one of these alone would also block eligibility. - No «our HPC» compute submitted: there is nothing computational to run. Honest drop, not a failure to reproduce.
Honesty note
This is verified, not assumed: the abstract, methods, statistics section, and data-availability statement were read from PubMed + Europe PMC + the PMC full text (PMC7604721). All three sources agree — no omics, no accession, no code.
Assessments & scoring basis
Each contributor’s verdict, the per-question basis, and the auditable, itemised worksheet behind it.
An automated assessment. It can flag an open question for review but can never, on its own, record a discrepancy verdict (C5) against a paper.
Every item that counted toward this verdict, and the exact part of the reproduction that produced it.
This is an honest non_pipeline drop, not a reproduction failure. The paper (J Lipid Res 2020, PMC7604721) is a Ucp1-/- vs WT mouse metabolic-physiology study whose readouts are entirely wet-lab (radiotracer uptake, glucose/lipid tolerance, qRT-PCR ddCt, Western blot, Adiposoft histology) with statistics in Excel/GraphPad Prism — there is no omics, no public accession, and no code to run. The blocker sits on the data-availability side ('upon reasonable request'), so q1/q2 are red while q5/q7 are held at yellow per the rubric's caution against penalizing authors for restricted data. No fabrication concern; severity is effectively none because nothing was computed to deviate.
Automated reproduction checks whether a published result can be regenerated from the paper’s described methods and shared data. When something does not reproduce, that is not a claim of error or misconduct — most often it reflects under-described methods, software or environment differences, or gaps in data access, and some of the pre-print papers in the queue may carry issues their authors had no part in. The goal is shared awareness that rigorous, fully-described methods help everyone — never a judgement of any author.
Are you an author? We would genuinely like to hear from you — to clarify the record, add data or code, re-run the pipeline after an accession update, and publish your response right next to the assessment. Everything here is open and auditable.
🚩 Report an error in this record
Spotted something wrong — a verdict you’d contest, a data or value error, or a private detail that slipped through? Tell us, with a short justification. Authors and readers are equally welcome to write in; we review every report.
Prefer email, or the form below not working? Contact us at support@doesitreproduce.com.
Reproduction footprint
claude-opus-4-8Measured resources invested to assess this paper — sanitised (machine class only, no job ids/paths). Compute = HPC accounting (SLURM); tokens = the AI agent's session.