Dietary Cholesterol Fails to Stimulate the Human Cholesterol 7α-Hydroxylase Gene (CYP7A1) in Transgenic Mice
Bibliographic record
Abstract
Dietary cholesterol has been shown to have a stimulatory effect on the murine cholesterol 7alpha-hydroxylase gene (Cyp7a1), but its effect on human cholesterol 7alpha-hydroxylase gene (CYP7A1) expression in vivo is not known. A transgenic mouse strain harboring the human CYP7A1 gene and homozygous for the disrupted murine Cyp7a1 gene was created. Cholesterol feeding increased the expression of the endogenous modified Cyp7a1 allele but failed to stimulate the human CYP7A1 transgene. In transfected hepatoma cells, 25-hydroxycholesterol increased murine Cyp7a1 gene promoter activity, whereas the human CYP7A1 gene promoter was unresponsive. Electrophoretic mobility shift assays demonstrated the interaction of the liver X receptor alpha (LXRalpha): retinoid X receptor (RXR) heterodimer, a transcription factor complex that is activated by oxysterols, with the murine Cyp7a1 gene promoter, whereas no binding to the human CYP7A1 gene promoter was detected. The results demonstrate that the human CYP7A1 gene is not stimulated by dietary cholesterol in the intact animal, and this is attributable to the inability of the CYP7A1 gene promoter to interact with LXRalpha:RXR.
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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".