Preliminary Observations on the use of Short‐term Ambient Cooling during a Day‐long Extreme Heat Exposure on Autophagy in Older Adults
Notice bibliographique
Résumé
Aging is associated with impairments in autophagy, which is an integral cellular survival mechanism. Our ongoing work indicates that heat stress may worsen this age‐related impairment after a daylong (9‐hour) passive heat exposure (40°C) as assessed in peripheral blood mononuclear cells (PBMC). This was paralleled by a greater elevation in body core temperature in older compared to young adults, which together with diminished autophagy, may contribute to compromised health during extreme heat events (EHE). National and international health agencies widely recommend the use of short‐term ambient cooling (STAC; e.g., visiting a cooling center) to protect the health of vulnerable individuals during an EHE; however, its effects on body core temperature and autophagic function are currently unclear. We therefore sought to extend upon our previous work by assessing if STAC would mitigate rises in body core temperature, and thus, the heat‐related decline in autophagy in older adults during a simulated EHE. We evaluated the hypothesis that in parallel to a reduction in body core temperature, autophagy would be preserved in PBMCs from older adults exposed to STAC during the EHE when compared to those without access to a cool room. To assess this hypothesis, as part of a larger study evaluating thermal strain in older adults, autophagy was characterized in PBMCs of 7 older adults (mean [SD] 71 [5] years; 3 women) prior to and following a 9‐h heat exposure (40°C, ~15% relative humidity [RH]), with 2 h of exposure to a cool room (~23ºC; STAC) for hours 5 and 6. Responses were compared with 10 older adults (71 [3] years; 2 women) who had previously participated in a prolonged 9‐h exposure to an EHE (40°C, ~15% RH). Changes in autophagy were assessed via Western blot for autophagy‐related proteins p62 and microtubule associated protein 1 light chain 3 beta (LC3)‐II. All proteins were normalized to β‐actin and reported as fold changes relative to their respective baseline. Rectal temperature (T re ) was measured throughout and expressed as a change from baseline. Data were compared between‐groups using unpaired t‐tests (α=0.05). Following the first 4 h of heat exposure, T re did not differ between groups (both ~0.9 [0.3]°C; p>0.99), although following STAC (hour 6) T re was lower (by 0.8 [0.4]°C; p<0.001) than the non‐cooled group. Again, however, no significant difference between groups was observed at the end of the 9‐h exposure (both ~0.9 [0.2]°C; p>0.99). Despite this, p62 protein at end‐exposure (9 h) was lower in the STAC group when compared to the non‐cooled group (0.78 [0.51] vs. 2.57 [2.19]; p=0.03) and this was accompanied by a reduction in LC3‐II (0.72 [0.33] vs. 2.13 [1.83]; p=0.04). Given, LC3‐II and p62 undergo lysosomal degradation (indicative of normal autophagic function), our preliminary findings indicate STAC may reduce the time spent in a hyperthermic state, thereby preserving autophagy during a simulated EHE in older adults. Further work is required to evaluate if alternate cooling strategies (i.e., fan use) can preserve autophagic function in older adults during prolonged heat stress.
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 | 0,001 |
| 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 ».