Skeletal muscle impairment and proteomic profil in human pulmonary arterial hypertension
Bibliographic record
Abstract
Introduction: the most important symptom of pulmonary arterial hypertension (PAH) is exercise intolerance leading poor quality of life. Numerous observations suggest that exercise limitation in PAH is not solely due to pulmonary hemodynamic impairment, but that other determinants such as skeletal muscle abnormalities are involved. In order to better understand the origins of exercise limitation in PAH, we studied the proteomic signature of skeletal muscle impairment in patients with idiopathic PAH (iPAH). Methods and results: Muscle proteins from 4 iPAH patients and 4 sex and age matched controls were extracted following quadriceps muscle biopsy. Fractioned peptides were then tagged using isobaric Tags for Relative and Absolute Quantitation (iTRAQ, ABsciex) specific for each patient. Over 900 proteins were identified using iTRAQ analysis, among them, 9 were under-expressed and 7 were over-expressed in all iPAH patient quadriceps. In silico analysis revealed that more than 75% of the under-expressed proteins are involved in oxidative metabolism and most other highlighted proteins play a role in myogenesis. These findings were structurally associated with decreased mitochondrial density (citrate synthase assay) and impaired mitochondrial structure measured by electronic microscopy, while muscle fibers distribution was unchanged. Functionally, all these abnormalities resulted in decreases in oxidative metabolism Conclusions: For the first time in humans, we provide evidences that, as in lungs and the right ventricle, the impaired mitochondrial/metabolism function is also present in skeletal muscle suggesting that PAH might be considered as a global mitochondrial/metabolic disease.
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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) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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".