Acute lung injury by gastric fluid instillation: activation of myofibroblast apoptosis during injury resolution

dc.contributor.authorAyala, Pedro
dc.contributor.authorTorres, Jorge
dc.contributor.authorVivar, Raúl
dc.contributor.authorMeneses, Manuel
dc.contributor.authorOlmos Coelho, Pablo Roberto
dc.contributor.authorSan Martín, Tamara
dc.contributor.authorBorzone, Gisella
dc.date.accessioned2019-10-17T13:43:58Z
dc.date.available2019-10-17T13:43:58Z
dc.date.issued2018
dc.date.updated2019-10-14T18:48:22Z
dc.description.abstractAbstract Background Gastric contents aspiration in humans has variable consequences depending on the volume of aspirate, ranging from subclinical pneumonitis to respiratory failure with up to 70% mortality. Several experimental approaches have been used to study this condition. In a model of single orotracheal instillation of gastric fluid we have shown that severe acute lung injury evolves from a pattern of diffuse alveolar damage to one of organizing pneumonia (OP), that later resolves leaving normal lung architecture. Little is known about mechanisms of injury resolution after a single aspiration that could be dysregulated with repetitive aspirations. We hypothesized that, in a similar way to cutaneous wound healing, apoptosis may participate in lung injury resolution by reducing the number of myofibroblasts and by affecting the balance between proteases and antiproteases. Our aim was to study activation of apoptosis as well as MMP-2/TIMP-2 balance in the sub-acute phase (4–14 days) of gastric fluid-induced lung injury. Methods Anesthesized Sprague-Dawley rats received a single orotracheal instillation of gastric fluid and were euthanized 4, 7 and 14 days later (n = 6/group). In lung tissue we studied caspase-3 activation and its location by double immunofluorescence for cleaved caspase-3 or TUNEL and alpha-SMA. MMP-2/TIMP-2 balance was studied by zymography and Western blot. BALF levels of TGF-β1 were measured by ELISA. Results An OP pattern with Masson bodies and granulomas was seen at days 4 and 7 that was no longer present at day 14. Cleaved caspase-3 increased at day 7 and was detected by immunofluorescence in Masson body-alpha-SMA-positive and –negative cells. TUNEL-positive cells at days 4 and 7 were located mainly in Masson bodies. Distribution of cleaved caspase-3 and TUNEL-positive cells at day 14 was similar to that in controls. At the peak of apoptosis (day 7), an imbalance between MMP-2 activity and TIMP-2 expression was produced by reduction in TIMP-2 expression. Conclusions Apoptosis is activated in Masson body-alpha-SMA–positive and –negative cells during the sub-acute phase of gastric fluid-induced lung injury. This mechanism likely contributes to OP resolution, by reducing myofibroblast number and new collagen production. In addition, pre-formed collagen degradation is favored by an associated MMP-2/TIMP-2 imbalance.
dc.fuente.origenBiomed Central
dc.identifier.citationRespiratory Research. 2018 Apr 10;19(1):57
dc.identifier.doi10.1186/s12931-018-0763-6
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/26647
dc.identifier.urihttps://doi.org/10.1186/s12931-018-0763-6
dc.issue.numeroNo. 57
dc.language.isoen
dc.pagina.final12
dc.pagina.inicio1
dc.revistaRespiratory Researches_ES
dc.rights.holderThe Author(s).
dc.subject.ddc610
dc.subject.deweyMedicina y saludes_ES
dc.subject.otherNeumonitis por aspiraciones_ES
dc.subject.otherPulmones - insuficienciaes_ES
dc.subject.otherPulmones - Enfermedadeses_ES
dc.subject.otherJugo gástricoes_ES
dc.titleAcute lung injury by gastric fluid instillation: activation of myofibroblast apoptosis during injury resolutiones_ES
dc.typeartículo
dc.volumenVol. 19
sipa.codpersvinculados1013060
sipa.codpersvinculados98490
sipa.codpersvinculados98949
sipa.codpersvinculados99892
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