Detection and Regulation of the Messenger for a Putative Bovine Endometrial 9-Keto-Prostaglandin E2 Reductase: Effect of Oxytocin and Interferon-Tau1
Bibliographic record
Abstract
During reproductive processes, prostaglandin (PG) E(2) (PGE(2)) and PGF(2alpha) play important roles in which they often exert opposite effects. At the time of recognition of pregnancy in vivo, PGF(2alpha) is recognized as the luteolytic factor in ruminants and in most species including human, whereas PGE(2) may exert a luteoprotective action. We have previously demonstrated that recombinant interferon-tau (rIFN-tau), the embryonic signal responsible for recognition of pregnancy in ruminants, stimulated in vitro the production of PGE(2) and prostaglandin-endoperoxide synthase 2 (Ptgs2; also called cyclooxygenase-2) gene expression in both epithelial and stromal endometrial cells. Since PGE(2) is the major prostaglandin produced by stromal cells, the effect on Ptgs2 could explain the increase in PGE(2) output. At high concentrations, however, recombinant ovine (ro) IFN-tau acts on epithelial cells by changing the primary PG produced from PGF(2alpha) to PGE(2). This change in the primary PG produced could be explained by a decrease in PGF synthase (PGFS) activity or an increase in PGE synthase activity, or by modulation of a putative PGE(2)-9-ketoreductase, which converts PGE(2) into PGF(2alpha). Therefore, we have investigated the regulation of the mRNAs for PGFS and PGE(2)-9-ketoreductase (9K-PGR), two enzymes that lead to the production of PGF(2alpha). Others have described 9K-PGR activity in uterus, ovaries, kidney, and liver of different species and have established that this enzyme could possess both 9K-PGR and 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) activity. Some have concluded that 9K-PGR and 20alpha-HSD are identical enzymes. Using primers sequences chosen from homologous nucleotide sequences of published rabbit 20alpha-HSD/9K-PGR and rat 20alpha-HSD cDNAs, a 317-base pair (bp) fragment was amplified by reverse transcription-polymerase chain reaction (RT-PCR), cloned, and sequenced. Homologies of 83% and 78% were found with rabbit and rat 20alpha-HSD, respectively. The presence of 20alpha-HSD/9K-PGR and prostaglandin F synthase (PGFS) mRNA expression was studied semiquantitatively in cultured epithelial cells using RT-PCR. Stimulation of cells with roIFN-t resulted in a biphasic response, an inhibition of PGF(2alpha) production at low dose (1 ng/ml) and a stimulation of PGE(2) at high dose (10 microg/ml). The increase of PGE(2) was accompanied by reduced 9K-PGR and PGFS mRNA gene expression. The effect of oxytocin (OT) was also studied, and the presence of OT had no effect on either 9K-PGR or PGFS gene expression. The 20alpha-HSD/9K-PGR transcript was also detected in other bovine tissues at different intensity (liver > kidney > testis > ovaries). We believe that the 9K-PGR and PGFS can be key enzymes in the regulation of specific PGs in the endometrium during the periimplantation period.
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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 | 0.001 | 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".