Rapamycin‐sensitive phase of 3T3‐L1 preadipocyte differentiation after clonal expansion
Bibliographic record
Abstract
Inhibition of insulin-induced 3T3-L1 preadipocyte differentiation by rapamycin has been attributed to a blockade of the early critical clonal expansion phase of the adipogenic program. Rapamycin binds to, and inhibits, mTOR (mammalian target of rapamycin), leading to diminution of p70 S6 kinase activity and eukaryotic initiation factor 4E binding protein 1 (eIF4E-BP1) function. Our objective was to determine if rapamycin-sensitive pathways exist subsequent to the clonal expansion phase. We determined that the mitotic clonal expansion was complete by day 4 of the differentiation protocol, based on the response to Ara-C (cytosine beta-D-arabinofuranoside), which only inhibits differentiation when administered during this phase. Treatment of differentiating 3T3-L1 cells with rapamycin, starting on day 4, exerted potent negative effects on glycerol phosphate dehydrogenase activity, and triacylglycerol accumulation, as well as on the protein expression of adipogenic transcription factors, C/EBPalpha and PPARgamma. Insulin-stimulated p70 S6 kinase activity, and its inhibition by rapamycin, were comparable in preadipocytes at day 0 vs. day 4 post-differentiation. We conclude that a component of the adipogenic program, operating after the completion of clonal expansion, is inhibited by rapamycin, suggesting an ongoing need for mTOR function in this process.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".