Matrix accumulation by articular chondrocytes during mechanical stimulation is influenced by integrin‐mediated cell spreading
Bibliographic record
Abstract
We have shown previously that cyclic compression of newly forming bioengineered cartilage in vitro results in improved tissue formation via changes in expression of matrix metalloproteases, such as, MT1-MMP (membrane type metalloprotease), and increased synthesis of matrix molecules. Several studies have suggested an association between MT1-MMP and integrins, which are known to influence cell shape. Thus, the objectives of this study were to determine the effect of compressive mechanical stimulation on cell shape and the role of integrins and MT1-MMP in mediating these changes and influencing matrix accumulation. Bovine articular chondrocytes were grown on the surface of a porous ceramic substrate for 72 h and then cyclically compressed for 30 min. Scanning electron microscopy and morphometric analysis demonstrated that compression induced a rapid, transient increase in chondrocyte spreading by 10 min, followed by a retraction to prestimulated size within 6 h. This was associated with increased accumulation of newly synthesized proteoglycans, as determined by quantification of radioisotope incorporation. Blocking the alpha5beta1 integrin, or its beta1 subunit, inhibited cell spreading and resulted in a partial inhibition of compression-induced increase in matrix accumulation. Knockdown of MT1-MMP expression partially inhibited cell retraction and resulted in a reduced matrix accumulation as well. These results suggest that chondrocyte spreading and retraction following cyclic compression in vitro regulates matrix accumulation. Understanding the mechanisms that regulate chondrocyte mechanotransduction may ultimately lead to the design of improved repair tissue for cartilage damage. (c) 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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 teacher head, 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".