Nitric Oxide and cGMP Induce COX-2 Expression and PGE<sub>2</sub>Production in Human Granulosa Cells Through CREB Signaling Pathway
Bibliographic record
Abstract
CONTEXT: It is well known that cyclooxygenase-2 (COX-2) and its major derivative product prostaglandin E2 (PGE2) play key regulatory roles in the ovulation process. Animal studies have demonstrated that the inhibition of nitric oxide (NO) suppresses ovarian PGE2 production and ovulation. Although the expression of NO synthases has been detected in human granulosa cells, the effect of NO on COX-2 expression and PGE2 production in these cells remains unknown. OBJECTIVE: The purpose of this article was to investigate the effects of NO on COX-2 expression and PGE2 production in human granulosa cells. DESIGN: SVOG cells are human granulosa cells that were obtained from women undergoing in vitro fertilization and immortalized with simian virus 40 large T antigen. SVOG cells were used to investigate the effects of NO on COX-2 expression and PGE2 production. SETTING: The study was conducted in an academic research center. MAIN OUTCOME MEASURES: The levels of mRNA and protein were examined by RT-quantitative real-time PCR and Western blotting, respectively. The accumulation levels of PGE2 were measured by ELISA. RESULTS: Treatment with the NO donor S-nitroso-N-acetyl-DL-penicillamine (SNAP) induced COX-2 expression and PGE2 production. In addition, the stimulatory effect of SNAP on COX-2 and PGE2 was mimicked by treatment with the cGMP analog 8-bromo-cGMP (8-Br-cGMP). Interestingly, neither SNAP nor 8-Br-cGMP affected the expression of COX-1. Moreover, our results showed that either SNAP or 8-Br-cGMP activated cAMP response element-binding protein (CREB) signaling and that the knockdown of CREB attenuated SNAP- and 8-Br-cGMP-induced COX-2 expression and PGE2 production. CONCLUSION: CREB mediates NO and cGMP-induced COX-2 expression and PGE2 production, which subsequently contribute to NO-regulated ovulation in human granulosa cells.
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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) | 0.003 | 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".