Open Accessα2A-adrenoceptor deficiency attenuates lipopolysaccharide-induced lung injury by increasing norepinephrine levels and inhibiting alveolar macrophage activation in acute respiratory distress syndrome
Author(s) -
Zhukai Cong,
Dan Li,
Xiangpeng Lv,
Cui Yang,
Qiang Zhang,
ChangYi Wu,
Zongyu Wang,
Xi Zhu
Publication year - 2020
Publication title -
clinical science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.91
H-Index - 138
eISSN - 1470-8736
pISSN - 0143-5221
DOI - 10.1042/cs20200586
Subject(s) - ards , medicine , lipopolysaccharide , lung , cxcl1 , alveolar macrophage , tumor necrosis factor alpha , inflammation , stimulation , diffuse alveolar damage , proinflammatory cytokine , endocrinology , immunology , pharmacology , macrophage , chemistry , acute respiratory distress , chemokine , in vitro , biochemistry
Acute respiratory distress syndrome (ARDS) is a severe condition with high morbidity and mortality and few interventions. The role of sympathetic stress in the pathogenesis of ARDS has attracted recent research attention. Blockade of α-2 or α2A-adrenoceptor (α2A-AR) has been shown to attenuate lung injury induced by lipopolysaccharide (LPS) in rats. However, the mechanism is unclear. We confirmed the role of α2A-AR in ARDS using knockout mice and alveolar macrophages following LPS stimulation to assess the underlying mechanisms. We found that α2A-AR deficiency decreased the permeability of the alveolar capillary barrier in ARDS mice and suppressed lung inflammation by reducing inflammatory cell infiltration and the production of TNF-α, interleukin (IL)-6, and CXCL2/MIP-2. LPS stimulation decreased NF-κB activation in lung tissues of α2A-AR deficient mice and increased norepinephrine concentrations. In vitro, we found that norepinephrine inhibited the production of TNF-α, IL-6, and CXCL2/MIP-2 and promoted the secretion of IL-10 from LPS-stimulated murine alveolar macrophages. Blockade of α2A-AR by a specific antagonist further inhibited the production of TNF-α, IL-6, and IL-10. Furthermore, norepinephrine down-regulated NF-κB activation in stimulated alveolar macrophages. Altogether, these results suggest that α2A-AR deficiency ameliorates lung injury by increasing norepinephrine concentrations in lung tissues and inhibiting the activation of alveolar macrophages.