The Orphan Nuclear Estrogen Receptor-Related Receptor-α Regulates Cartilage Formation<i>in Vitro</i>: Implication of Sox9
Bibliographic record
Abstract
We report for the first time the expression of estrogen receptor-related receptor (ERR)-alpha in fetal and adult rat chondrocytes in growth plate and articular cartilage and the rat chondrogenic cell line C5.18 cells in vitro. ERRalpha mRNA and protein were expressed from proliferating chondrocyte to mature chondrocyte stages. We show that overexpressing ERRalpha in C5.18 cell cultures induces an increase in Sry-type high-mobility-group box transcription factor (Sox)-9 expression, a master gene in cartilage formation. In parallel, we report Sox9 promoter regulation by ERRalpha in C5.18 cells. To assess a functional role for ERRalpha in chondrogenesis, its expression was blocked by antisense oligonucleotides in C5.18 cell cultures, and this led to inhibition of cartilage formation associated with down-regulation of Sox9 and Indian hedgehog expression and maturation of proliferating chondrocytes into hypertrophic chondrocytes in vitro. Together these results implicate ERRalpha in the formation and maintenance of cartilage and also suggest that agonists and antagonists of ERRalpha may be useful as therapeutic agents in a wide variety of diseases affecting cartilage and joints.
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) | 0.001 | 0.000 |
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".