Peptide Blocking Self-Polymerization of Extracellular Calcium-Sensing Receptor Attenuates Hypoxia-Induced Pulmonary Hypertension
Bibliographic record
Abstract
Activation of the CaSR (extracellular calcium-sensing receptor) has been recognized as a critical mediator of hypoxia-induced pulmonary hypertension. Preventive targeting of the early initiating phase as well as downstream events after CaSR activation remains unexplored. As a representative of the G protein-coupled receptor family, CaSR polymerizes on cell surface upon stimulation. Immunoblotting together with MAL-PEG technique identified a reactive oxygen species-sensitive CaSR polymerization through its extracellular domain in pulmonary artery smooth muscle cells upon exposure to acute hypoxia. Fluorescence resonance energy transfer screening employing blocking peptides determined that cycteine129/131 residues in the extracellular domain of CaSR formed intermolecular disulfide bonds to promote CaSR polymerization. The monitoring of intracellular Ca 2+ signal highlighted the pivotal role of CaSR polymerization in its activation. In contrast, the blockade of disulfide bonds formation using a peptide decreased both CaSR and hypoxia-induced mitogenic factor expression as well as other hypoxic-related genes in vitro and in vivo and attenuated pulmonary hypertension development in rats. The blocking peptide did not affect systemic arterial oxygenation in vivo but inhibited acute hypoxia-induced pulmonary vasoconstriction. Pharmacokinetic analyses revealed a more efficient lung delivery of peptide by inhaled nebulizer compared to intravenous injection. In addition, the blocking peptide did not affect systemic arterial pressure, body weight, left ventricular function, liver, or kidney function or plasma Ca 2+ level. In conclusion, a peptide blocking CaSR polymerization reduces its hypoxia-induced activation and downstream events leading to pulmonary hypertension and represents an attractive inhaled preventive alternative worthy of further development.
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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 | 0.000 | 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) | 0.000 | 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".