Mechanical strain and dexamethasone selectively increase surfactant protein C and tropoelastin gene expression
Bibliographic record
Abstract
Physical forces derived from fetal breathing movements and hormones such as glucocorticoids are implicated in regulating fetal lung development. To elucidate whether the different signaling pathways activated by physical and hormonal factors are integrated and coordinated at the cellular and transcriptional levels, organotypic cultures of mixed fetal rat lung cells were subjected to static culture or mechanical strain in the presence and absence of dexamethasone. Tropoelastin and collagen type I were used as marker genes for fibroblasts, whereas surfactant protein (SP) A and SP-C were used as marker genes for distal epithelial cells. Mechanical strain, but not dexamethasone, significantly increased SP-C mRNA expression. Tropoelastin mRNA expression was upregulated by both mechanical strain and dexamethasone. No additive or synergistic effect was observed when cells were subjected to mechanical stretch in the presence of dexamethasone. Neither mechanical strain nor dexamethasone alone or in combination had any significant effect on the expression of SP-A mRNA. Dexamethasone decreased collagen type I mRNA expression, whereas mechanical strain had no effect. The increases in tropoelastin and SP-C mRNA levels induced by mechanical strain and/or dexamethasone were accompanied by increases in their heterogeneous nuclear RNA. In addition, the stretch- and glucocorticoid-induced alterations in tropoelastin and SP-C mRNA expression were abrogated with 10 microg/ml actinomycin D. These findings suggest that tropoelastin and SP-C genes are selectively stimulated by physical and/or hormonal factors at the transcriptional level in fetal lung fibroblasts and distal epithelial cells, respectively.
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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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| 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".