Estrogen Related Receptor-α Enhances<i>Surfactant Protein-A</i>Gene Expression in Fetal Lung Type II Cells
Bibliographic record
Abstract
Surfactant protein-A (SP-A) gene expression is developmentally regulated in fetal lung type II cells in concert with surfactant glycerophospholipid synthesis. In studies using transfected type II cells, we characterized a nuclear receptor element (NRE(SP-A), 5'-TGACCTTA-3') at -242 bp in the 5'-flanking sequence of human SP-A2 (hSP-A) gene that is essential for basal and cAMP-induced expression. NRE(SP-A) has high sequence similarity to the consensus binding site for estrogen-related receptor (ERR). In the present study, we observed that ERRalpha and ERRgamma, but not ERRbeta, were expressed in human fetal lung type II cells. In vitro transcribed/translated ERRalpha and ERRgamma bound to the NRE(SP-A); DNase I footprinting using bacterially expressed ERRalpha revealed a single DNase I protected region that included NRE(SP-A). In transient transfection assays of COS-7 and primary cultures of lung type II cells, ERRalpha acting through NRE(SP-A) increased hSP-A promoter activity, whereas ERRgamma had no effect. ERRalpha overexpression in lung type II cells enhanced cAMP induction of endogenous hSP-A expression, whereas cotransfection of protein kinase A catalytic subunit enhanced ERRalpha stimulation of hSP-A promoter activity in lung adenocarcinoma cells. Mice homozygous null for the ERRalpha gene manifested decreased SP-A expression relative to wild-type and heterozygous littermates. The ERRalpha-specific inverse agonist XCT790 inhibited cAMP induced hSP-A expression in human fetal lung type II cells in a concentration-dependent manner, suggesting a role of peroxisome proliferator-activated receptor-gamma coactivator 1alpha. These findings suggest that ERRalpha acting through NRE(SP-A) is an important mediator of hSP-A gene expression and its induction by cAMP.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
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".