Mechanosensitive ATP Release Through Transient Membrane Rupture in Alveolar Epithelial Cells
Notice bibliographique
Résumé
Mechanical ventilation (MV) is critical for the survival of patients with respiratory distress, but it can also exacerbate their symptoms: a condition called ventilator‐induced lung injury (VILI). Innate protection to attenuate VILI symptoms includes adenosine (Ado), an anti‐inflammatory mediator known to promote resolution of pulmonary edema. Airways‐localized Ado is a breakdown product of ATP by ectoenzymes, and high level of ATP has been found in the airways at the onset of MV treatment. Since stretch is a potent ATP secretion stimulus, this elevated ATP level has been explained by the intense deformation experienced by lung cells during MV. While ATP‐permeable channels or exocytosis have been frequently proposed as probable mechanisms for mechanosensitive ATP release, the pathway for cell stretch‐induced ATP secretion remains to be firmly identified. Here, we present an investigation on alveolar cells with a quantitative ATP imaging technique. Rat‐derived primary cultures of alveolar epithelial type 2 cells grown in a compliant silicone chamber for 7 days were uniaxially stretched to 30% linear deformation at varying strain rate and hold time. Level of extracellular ATP in medium was quantified with an ATP‐dependent luciferase‐luciferin light‐emitting reaction and wide field of view imaging of the whole stretch chamber (2×18 mm). Pre‐ and post‐stretch uptake of the plasma membrane impermeant DNA intercalator‐type propidium iodide (PI) dye was evaluated by epifluorescence microscopy. We first observed a strong spatial and temporal correlation between density distribution of extracellular ATP and PI uptake in response to stretch, suggesting a conductive pathway for ATP secretion. High rate of ATP release per cell ruled out involvement of ATP‐permeable channels however, and was instead consistent with a membrane rupture process. Quantification of PI fluorescence uptake suggested that almost all of the detected extracellular ATP leaked through those transient cracks. In addition, the fast decline of ATP response as soon as cell deformation ceased (half‐life ~5 seconds), excluded the involvement of slow acting membrane repair processes for the closure of the ATP‐permeable pathways but rather suggested rapid recoil of elastic membrane components. Further proof implicating the viscoelastic plasma membrane came from two prominent characteristics of the stretch‐induced ATP response: relaxation and sensitivity to strain rate, both hallmarks of viscoelasticity. This study gathered evidence to support an alternate mechanism of ATP release by mechanical stretch; one occurring through transient membrane rupture. This lytic mechanism is most likely non‐lethal however, due to the fast resealing of these membrane breaks resulting in minimal trauma on cells. We expect such cellular ATP release mechanism to contribute for the early detection of ATP inside mechanically‐ventilated lungs. This knowledge may help to shape a MV load history optimized to stimulate ATP release, and subsequent Ado formation, in order to minimize VILI‐associated symptoms. Support or Funding Information Supported by the Canadian Institutes of Health Research (PJT166157 to R.G.)
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 machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| 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) | 0,001 | 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 source (Gemma direct ou Codex distillé), 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 ».