Modulation of renal Ca <sup>2+</sup> transport protein genes by dietary Ca <sup>2+</sup> and 1,25‐dihydroxyvitamin D <sub>3</sub> in 25hydroxyvitamin D <sub>3</sub> ‐1α‐hydroxylase knockout mice
Bibliographic record
Abstract
ABSTRACT Pseudovitamin D‐deficiency rickets (PDDR) is an autosomal disease characterized by hyperparathyroidism, rickets, and undetectable levels of 1,25‐dihydroxyvitaminD 3 (1,25(OH) 2 D 3 ). Mice in which the 25hydroxyvitamin D 3 ‐1α‐hydroxylase (1α‐OHase) gene was inactivated presented the same clinical phenotype as patients with PDDR and were used to study renal expression of the epithelial Ca 2+ channel (ECaC1), the calbindins, Na + /Ca 2+ exchanger (NCX1), and Ca 2 + ‐ATPase (PMCA1b). Serum Ca 2+ (1.20±0.05 mM) and mRNA/ protein expression of ECaC1 (41±3%), calbindin‐D 28K (31±2%), calbindin‐D 9K (58±7%), NCX1 (10±2%), PMCA1b (96±4%) were decreased in 1α‐OHase −/− mice compared with 1α‐OHase +/‐ littermates. Feeding these miceaCa 2+ ‐enriched diet normalized serum Ca 2+ levels and expression of Ca 2+ proteins except for calbindin‐D 9K expression. 1,25(OH) 2 D 3 repletion resulted in increased expression of Ca 2+ transport proteins and normalization of serum Ca 2+ levels. Localization of Ca 2+ transport proteins was clearly polarized in which ECaC1 was localized along the apical membrane, calbindin‐D 28K in the cytoplasm, and calbindin‐D 9K along the apical and basolateral membranes, resulting in a comprehensive mechanism facilitating renal transcellular Ca 2+ transport. This study demonstrated that high dietary Ca 2+ intake is an important regulator of the renal Ca 2+ transport proteins in 1,25(OH) 2 D 3 ‐deficient status and thus contributes to the normalization of blood Ca 2+ levels.—Hoenderop, J. G. J., Dardenne, O., van Abel, M., van der Kemp, A. W. C. M., van Os, C. H., St.—Arnaud, R., Bindels, R. J. M. Modulation of renal Ca 2+ transport protein genes by dietary Ca 2+ and 1,25‐dihydroxyvitamin D 3 in 25 hydroxyvitamin D 3 ‐1α‐hydroxylase knockout mice. FASEB J. 16, 1398–1406 (2002)
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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) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".