A Link between Lung Androgen Metabolism and the Emergence of Mature Epithelial Type II Cells
Bibliographic record
Abstract
Lung maturation is delayed in male fetuses compared with female fetuses, which has been attributed to higher levels of androgens in the male lung. Our previous studies demonstrated that the genes encoding for the 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) type 5 (androstenedione --> testosterone) and type 2 (the opposite reaction) are expressed in human epithelial type II (PTII)-like A549 cells and in human lung fibroblasts, respectively. Here, we aim to explain the physiological relevance of androgen synthesis by PTII cells. We showed that both 17 beta-HSD type 2 and type 5 genes are upregulated in correlation with the emergence of mature PTII cells in both male and female developing lungs of the mouse. In contrast, the androgen receptor gene is expressed equally in both sexes with no temporal regulation. We conclude that the expression profile of the 17 beta-HSD type 5 gene does not explain the presence of higher levels of androgen in the male fetal lung, but that androgen synthesis must be a normal feature of mature PTII cells for both sexes. The production of androgens after the emergence of mature PTII cells should negatively regulate PTII cell maturation and, thus, a role for androgens in cell reprogramming is suggested.
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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) | 0.002 | 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 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".