Effects of hypoxia on heme oxygenase expression in human chorionic villi explants and immortalized trophoblast cells
Bibliographic record
Abstract
Although hypoxia induces heme oxygenase (HO)-1 protein and mRNA expression in many cell types, hypoxia has also been shown to decrease HO-1 mRNA and protein expression. We tested the hypothesis that 24-h preexposure to hypoxia in human placental preparations suppresses HO protein expression and enzymatic function. Immortalized HTR-8/SVneo first-trimester trophoblast cells and explants of normal human chorionic villi (CV) from term placentas were cultured for 24 h in 1%, 5%, or 20% O(2). HO protein levels were determined by Western blot analysis, and microsomal HO activity was measured. HO-2 protein content was decreased by 17% and 5% in human trophoblast cells after 24-h exposure to 1% and 5% O(2), respectively, versus 20% O(2). In contrast, HO-2 protein content in CV explants was unaffected by changes in oxygenation. HO-1 protein content, which was barely detectable in both biological systems, was not affected by changes in oxygenation. Similarly, HO enzymatic activity was unchanged in both preparations after 24-h exposure to 1%, 5%, or 20% O(2). The above data do not support the hypothesis that hypoxia in the human placenta suppresses both HO protein content and HO protein function. The present observations reinforce the necessity to determine both HO protein expression and function.
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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) | 0.001 | 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".