Abstract 12789: Time-Dependent Changes in Mitochondrial Properties and Function in Dogs During Electrically Maintained Atrial Fibrillation
Bibliographic record
Abstract
Introduction: Atrial fibrillation (AF) causes atrial remodeling, leading to progressive resistance to therapy. Changes in cell metabolism likely contribute to remodeling; here, we studied the nature and time course of mitochondrial (MITO) changes during AF . Methods: Atrial cardiomyocytes were isolated from control dogs and dogs kept in AF for 24 hrs, 3 days, 1 and 3 wks by atrial tachypacing at 600 bpm (N=10/group). MITO were visualized with transmission electron microscopy. [Ca 2+ ] Mito (Rhod-2 AM), MITO ROS production (MitoSOX), membrane potential (αψ, JC-1), mPTP opening (TMRM) and FAD autofluorescence were measured via confocal microscope, NADH autofluorescence was determined under UV light. Protein expression was assayed by western blotting. Results: MITO elongation occurred following 24-hr and 3-day AF, while 3-week AF induced MITO fragmentation, rupture and shrinking (A). MITO fusion protein (MFN1) decreased from 3 days to 3 wks of AF and fission protein pDRP1ser-616 was increased at 1 and 3 wks of AF, potentially accounting for MITO fragmentation. [Ca 2+ ] Mito increased progressively with AF-time (B). MITO ROS production increased at 24 hr AF, and remained elevated from 3 days to 3 wks of AF (C). SOD2 was reduced after 3 days AF. NOX4 expression was increased at 3 wks AF. mPTP opening frequency and duration increased progressively during AF (D). AF increased JC-1 fluorescence, indicating depolarized αψ, beginning 24 hours after AF-onset (E). NADH increased by 15% at 24 hr AF, and then decreased progressively with AF-time (F). FAD was decreased during AF. Mitotempo (5-μM) reversed AF-induced atrial-cell I CaL downregulation (G) and reduced triggered activity (H). Conclusions: MITO are activated early during AF, but then show progressive changes likely due to ROS autotoxicity. MITO dysfunction and impaired bioenergetics may contribute to AF maintenance/ progress. MITO-targeted antioxidant intervention may have potential as a novel therapeutic approach for AF.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 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) | 0.001 | 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".