Abstract 16348: Ecto-Nucleotidase-Derived Adenosine Promotes Mineralization Through A2a Receptor in Calcified Aortic Valves Disease
Bibliographic record
Abstract
Background: Mineralization plays a crucial role in the development of calcific aortic valve disease (CAVD). The expression of ecto-nucleotidases may promote the mineralization of valve interstitial cells (VICs). We hypothesized that the expression of NPP1, which generates adenosine monophosphate (AMP), and 5’nucleotidase, an enzyme using AMP as a substrate to produce adenosine, may co-regulate the mineralization of the aortic valve. Methods: We have investigated the expression of NPP1 and 5’nucleotidase in CAVD tissues and determined the role of these ecto-nucleotidases on the mineralization of isolated VICs. The signaling pathway involving adenosine receptors was also studied. Results: In CAVD tissues, we documented that NPP1 and 5’nucleotidase enzyme activities were increased. NPP1 and 5’nucleotidase were co-expressed by VICs. In cell culture we found that mineralization induced by ATP was decreased by silencing NPP1 and 5’nucleotidase, suggesting a role for adenosine. Adenosine and specific A2a receptor agonist increased the calcification of VICs. Silencing of A2a receptor and the use of A2a-/- receptor mouse VICs abrogated adenosine-induced mineralization. Also, A2a receptor-mediated mineralization of VICs was negated by the transfection of a mutant dominant negative Gαs vector. Inhibition of the protein kinase A (PKA) pathway prevented adenosine-induced mineralization of VICs and expression of NPP1. We next showed that activation of PKA promoted in luciferase assay the activity of the NPP1 promoter. By using chromatin immunoprecipitation assay (ChIP) we documented that the cAMP response element binding protein (CREB), downstream of PKA, physically interacted with the NPP1 promoter region. Furthermore, the transfection of a mutant dominant active CREBDIEDML in isolated VICs increased the NPP1 promoter activity by 6.5-fold. Conclusion: The overexpression of NPP1 and 5’nucleotidase in CAVD promotes the mineralization of the aortic valve through A2a adenosine receptor, which signals through Gαs and the cAMP/PKA/CREB pathway. CREB is a positive regulator of NPP1 promoter activity in a positive feedback loop. The ecto-nucleotidases and/or A2a adenosine receptor could represent potential novel pharmaceutical targets in CAVD.
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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) | 0.001 | 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 | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 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".