Pharmacological activation of the cholinergic system attenuates lung inflammation in a Murine Model of acute respiratory distress syndrome

Abstract

Acute respiratory distress syndrome (ARDS) is characterized by acute lung inflammation involving both the recruitment and activation inflammatory cells as well as the release of inflammatory factors that cause lung injury and contributes to systemic inflammation. Despite advances in understanding the underlying pathogenic mechanisms of ARDS, no effective therapeutic approach has emerged. The anti‐inflammatory cholinergic reflex has been postulated as an important mechanism that modulates the immune system in both aseptic and septic experimental models. Pyridostigmine bromide (PB) is a reversible anticholinesterase agent that causes increased availability of acetylcholine and parasympathetic activity is routinely used in the treatment of myasthenia gravis. The aim of this study was to investigate the effect of cholinergic stimulation through the PB treatment on the pulmonary and systemic inflammatory response in an experimental model of LPS‐induced ARDS.MethodsC57Bl/6 male mice (n=24) were distributed into four groups Control (Control), pyridostigmine‐treated (PB), LPS installation (LPS), LPS installation and pyridostigmine treatment (PB+LPS) Animals were monitored for 72 hours. Acute respiratory distress syndrome (ARDS) model: Mice were anesthetized (ketamine 100 mg/kg and xylazine 10 mg/kg) and given one intratracheal instillation of 10 μg LPS/day per mice, during 3 days. Cholinergic stimulation: Pyridostigmine bromide (PB) 3 mg/kg/day was administered twice a day by oral gavage at 1h post‐LPS to achieve around 85–90% cholinergic inhibition as previously reported. After 72h, bronchoalveolar lavage fluid (BALF) was obtained to measure leukocyte infiltration and cytokine (IL‐6, IFN‐γ, IL‐1β e TNF and IL‐10) level in BALF and plasma.ResultsTreatment with PB after the bacterial endotoxin significantly reduced the number of both total cells and neutrophils in BAL fluid (p<0.001) and in the lung parenchyma (p<0.01). Reduced the levels of all of the inflammatory cytokines TNF, IL‐6 (p<0,001), and IL‐1β, IFN‐γ (p<0,01) but not IL‐10 levels in BALF when compared with LPS group. Reduced the levels of all of the inflammatory cytokines TNF (p<0,001), IL‐6, IL‐1β, IFN‐γ (p<0,01) and IL‐1β (p<0,05) but not the levels IL‐10 in plasma when compared with LPS group at 72 hours post‐treatment. In conclusion, the treatment with BP can activate the cholinergic system to attenuate lung inflammation in an experimental model of LPS‐induced ARDS. These results support the cholinergic system as an important pharmacological target for ARDS treatment.Support or Funding InformationSupport Post‐graduate stricto sensu Program UNINOVE and CAPESThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.