Nestin expression is lost in ventricular fibroblasts during postnatal development of the rat heart and re‐expressed in scar myofibroblasts
Bibliographic record
Abstract
Studies have reported that the intermediate filament protein nestin was expressed in various non-stem/progenitor cells during development, downregulated during postnatal growth and re-expressed following injury. The present study tested the hypothesis that an analogous paradigm was prevalent for ventricular fibroblasts. In the neonatal rat heart, nestin protein levels were significantly higher than the adult heart and the isolation of cardiac cells revealed a selective expression in ventricular fibroblasts. In adult ventricular fibroblasts, nestin protein expression was markedly lower compared to neonatal ventricular fibroblasts. Following ischemic damage to the rat heart, nestin staining was detected in a subpopulation of scar myofibroblasts (37%) and the percentage of immunoreactive cells was greater than adult ventricular fibroblasts (7%) but significantly lower than neonatal ventricular fibroblasts (86%). Moreover, dissimilar rates of (3)H-thymidine uptake were observed among the fibroblast populations and may be related in part to the disparate percentage of nestin(+) cells. To assess the role of nestin in DNA synthesis, neonatal ventricular fibroblasts were infected with a lentivirus containing a shRNAmir directed against the intermediate filament protein. The partial depletion of nestin expression in neonatal ventricular fibroblasts significantly reduced basal DNA synthesis, in the absence of an apoptotic response. Thus, postnatal development of the rat heart was associated with a selective loss of nestin expression in ventricular fibroblasts and subsequent induction in a subpopulation of myofibroblasts following ischemic injury. The re-expression of nestin in scar myofibroblasts may represent an adaptive response to enhance their proliferative rate and accelerate the healing process.
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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 | 0.000 | 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) | 0.000 | 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".