Lower Mitochondrial Proton Leak and Decreased Glutathione Redox in Primary Muscle Cells of Obese Diet-Resistant Versus Diet-Sensitive Humans
Bibliographic record
Abstract
CONTEXT: Weight loss success in response to energy restriction is highly variable. This may be due in part to differences in mitochondrial function and oxidative stress. OBJECTIVE: The objective of the study was to determine whether mitochondrial function, content, and oxidative stress differ in well-matched obese individuals in the upper [obese diet sensitive (ODS)] vs lower quintiles [obese diet resistant (ODR)] for rate of weight loss. DESIGN: Primary myotubes derived from muscle biopsies of individuals identified as ODS or ODR were studied. SETTING: Compliant ODS and ODR females who completed in the Ottawa Hospital Weight Management Program and identified as ODS and ODR participated in this study. PATIENTS OR OTHER PARTICIPANTS: Eleven ODS and nine ODR weight-stable females matched for age, body mass, and body mass index participated in this study. INTERVENTION: Vastus lateralis muscle biopsies were obtained and processed for muscle satellite cell isolation. MAIN OUTCOME MEASURES: Mitochondrial respiration, content, reactive oxygen species, and glutathione redox ratios were measured in the myotubes of ODS and ODR individuals. RESULTS: Mitochondrial proton leak was increased in myotubes of ODS compared with ODR (P < .05). Reduced and oxidized glutathione was decreased in the myotubes of ODR vs ODS (P < .05), indicating a more oxidized glutathione redox state. There were no differences in myotube mitochondrial content, uncoupling protein 3, or adenine nucleotide translocase levels. CONCLUSIONS: Lower rate of mitochondrial proton leak in muscle is a cell autonomous phenomenon in ODR vs ODS individuals, and this is associated with a more oxidized glutathione redox state in ODR vs ODS myotubes. The muscle of ODR subjects may thus have a lower capacity to adapt to oxidative stress as compared with ODS.
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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 | 0.000 |
| 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) | 0.002 | 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".