Activation of the Nrf-2 pathway improves the mitochondrial phenotype in skeletal muscle cells
Notice bibliographique
Résumé
Aging muscle displays a reduction in mitochondrial content, along with elevated reactive oxygen species (ROS) emission and reduced levels of antioxidant enzymes. These characteristics enhance tissue susceptibility to oxidative damage, facilitating sub-optimal cellular metabolism and subsequent muscle atrophy. While these perturbations to metabolic homeostasis are a natural course of the aging process, there has been ongoing research investigating how to implement interventions to reduce this decline in muscle health. Regular exercise is one possible treatment modality, however this may be unsuitable for some populations who are unable to participate due to their health status. The objective of this study was to examine the activation of the Nrf-2 pathway using the nutraceutical Sulforaphane (SFN) and evaluate its role as a potential exercise mimetic. We hypothesized that SFN would act through similar pathways activated with chronic exercise to improve mitochondrial content, respiration, and ROS emission. To address our objective, C2C12 myotubes were treated with SFN for various timepoints basally, and in the presence of the Complex-I inhibitor rotenone to induce oxidative stress. Western blotting revealed an 8-fold increase in Nrf-2 nuclear localization following 24hrs of SFN treatment, which subsequently led to the upregulation of antioxidant enzymes NQO1, Heme Oxygenase-1, catalase, glutathione reductase and Glucose-6-Phosphate Dehydrogenase by 2-to 3-fold. These protein changes, were accompanied by dramatic reductions in both total cellular and mitochondrial ROS emission with SFN, detected with CellROX Green and MitoSOX Red respectively. Interestingly, this led to an increase in mitochondrial membrane potential, detected via MitoTracker Red (MTR), despite rotenone-induced oxidative stress. Western blotting revealed TFAM upregulation at 24hrs, suggesting an increase in mitochondrial DNA (mtDNA) replication and transcription. This was corroborated by an increase in COX subunit I protein, a mitochondrially-encoded subunit of cytochrome c oxidase, as well as MitoTracker Green and MTR staining by 48hrs. Mitochondrial respiration was evaluated using Seahorse analysis, demonstrating a marked increase in ATP production as well as basal and maximal respiration. Together these data suggest that activation of the Nrf-2 pathway via SFN may lead to adaptations similar to chronic exercise. Additionally, SFN may have applications in disorders characterized by mitochondrial loss and high ROS emission. To fully elucidate the precise mechanisms underlying this agent, SFN will be combined with chronic contractile activity to determine if these two interventions operate through independent pathways. This work was supported by funds from the Natural Science and Engineering Research Council (NSERC). Sabrina Champsi is the recipient of the NSERC Alexander Graham Bell Canada Graduate Scholarship-Master’s (CGS-M). David A. Hood is the holder of a Canadian Research Chair in Cell Physiology. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».