YAP/TAZ regulates the expression of proteoglycan 4 and tenascin C in superficial-zone chondrocytes
Bibliographic record
Abstract
The roles of cell division control protein 42 homologue (CDC42) and actin polymerisation in regulating the phenotype of superficial-zone chondrocytes (SZCs) have been demonstrated in vitro; however, the signalling pathway(s) downstream have yet to be fully elucidated. The study hypothesis was that Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) act downstream to regulate proteoglycan 4 (PRG4) and tenascin C (TNC). Bovine SZCs grown in monolayer were treated with ML141 (CDC42 inhibitor) or the actin depolymerising agents, latrunculin B and cytochalasin D, to determine the effect on YAP/TAZ. Verteporfin (YAP/TAZ inhibitor) and YAP/TAZ siRNA-mediated knockdown were used to determine their role in regulating PRG4 and TNC. ML141 treatment reduced total YAP/TAZ protein, nuclear TAZ levels and the YAP/TAZ target gene, connective tissue growth factor (CTGF) mRNA levels. Latrunculin B decreased nuclear TAZ, while cytochalasin D treatment trended towards increased nuclear TAZ (p = 0.06), correlating with decreased and increased CTGF mRNA levels, respectively. Verteporfin treatment decreased PRG4 and TNC expression, with no effect on actin polymerisation. siRNA-mediated knockdown of YAP/TAZ revealed that PRG4 was regulated by YAP/TAZ while TNC was regulated by TAZ only. As cytochalasin D can activate myocardin-related transcription factor-A (MRTF-A), siRNA-mediated knockdown was performed to determine the role of MRTF-A in regulating YAP/TAZ. Although nuclear TAZ decreased, no significant changes in total protein levels were observed. Findings suggested that CDC42 and actin polymerisation regulated SZCs through multiple actin-regulated pathways. Understanding the regulation of these chondroprotective molecules may have important implications for prevention/treatment of osteoarthritis.
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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".