Regulation of neutrophil migration in acute pulmonary inflammation by extraneuronal α1 gamma-aminobutyric acid receptors.
作者信息
Fuhr Anika, Roediger Robin, Simelitidis Mariana, Gamper-Tsigaras Jutta, Templin Markus, Kormann Michael, Antkowiak Bernd, Rudolph Uwe, Köhler David, Rosenberger Peter, Ngamsri Kristian-Christos, Konrad Franziska M
机构信息
Department of Anesthesiology and Intensive Care Medicine, University Hospital of Tuebingen, Tübingen, Germany.
NMI Natural and Medical Sciences Institute, University Tuebingen, Tübingen, Germany.
出版信息
Cell Death Dis. 2025 Apr 18;16(1):313. doi: 10.1038/s41419-025-07488-1.
Acute pulmonary inflammation is a common disease on intensive care. Due to the lack of specific treatments, lethality is still very high. The ionotropic GABAreceptors are known from the central nervous system (CNS) and have recently been detected in the lung. These receptors have been shown to influence inflammatory processes. Opposing data has been reported, where both, GABA site agonists and antagonists achieved anti-inflammatory effects. The distribution of the 19 known GABAreceptor subunits (α1-6, β1-3, γ1-3, δ, ε, π, θ and ρ1-3) and their role in inflammation remain unclear. In murine models of LPS- and bacteria-induced inflammation, Muscimol (GABA-receptor agonist) and Bicuculline (antagonist) were administered before the onset of inflammation. Transcription of GABA-receptor subunits was evaluated by real-time polymerase chain reaction. Neutrophil counts and adhesion molecule expression in wild type and GABAα1 knock-in mice were determined by flow-cytometry. Myeloperoxidase, neutrophil extracellular traps and cytokines were determined. In a model of ventilator-induced lung injury, blood gas analysis was performed using arterial blood. A multiplex western blot was done to assess signaling proteins. Muscimol and Bicuculline inhibited neutrophil influx in the bronchoalveolar lavage but did not change neutrophil activation. Both altered surface expression of adhesion molecules on neutrophils and reduced release of interleukin-6 (IL-6). The increased α1 subunit expression on lung epithelium and endothelium after inflammation was abolished by Muscimol and Bicuculline. In GABAα1-knock-in mice the protective effects of both agents were no longer observed. Only Muscimol lowered protein extravasation, improved blood gas analysis and lung function. A multiplex assay ascribed these anti-inflammatory effects to the influence of the IL-6 and phosphoinositide 3-kinase signaling pathways. In conclusion, Muscimol and Bicuculline exert various protective effects in two murine models of acute pulmonary inflammation. The multiple effects of Muscimol were linked to the inhibition of the proinflammatory signaling pathways IL-6 and PI3K.