Tissue- and Site-Specific Gene Expression of Type 2 17β-Hydroxysteroid Dehydrogenase:<i>In Situ</i>Hybridization and Specific Enzymatic Activity Studies in Human Placental Endothelial Cells of the Arterial System<sup>1</sup>
Bibliographic record
Abstract
Progesterone and estradiol are the most potent human sex steroid hormones of placental origin and are essential to the maintenance of pregnancy, the timing of parturition, the maturation of many fetal organs, and the preparation of the maternal reproductive system. Naturally, regulatory mechanisms must be in place to coordinate the synthesis and inactivation of these two hormones. We have previously shown that the highest levels of type 1 and type 2 17beta-hydroxysteroid dehydrogenase (17betaHSD) messenger ribonucleic acids (mRNAs) occur in the placenta, particularly in the villi. However, in contrast to type 1 17betaHSD mRNA, type 2 17betaHSD mRNA was not detectable in cell cultures of human cytotrophoblasts or syncytiotrophoblasts. Using in situ hybridization, we unequivocally identified endothelial cells as the only cell type expressing the type 2 17betaHSD gene in fetal villi. Moreover, type 2 17betaHSD mRNA was specifically detected in the endothelial cells of the arterial system, and at higher levels in the villi compared with endothelial cells of the cord arteries when the two tissue sections were cohybridized. In fact, both mRNA levels and enzymatic activity are at their highest levels in arterial endothelial cells. In conclusion, the endothelial cells of the villous arterioles are the primary site of type 2 17betaHSD gene expression. This suggests a regulatory role for these cells in the control of progestin, androgen, and estrogen levels during pregnancy, thus opening a whole new way of viewing regionalization and localization of steroidogenesis in the human villi.
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 | 0.000 |
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".