Inhibition of Alveolar Macrophage Pyroptosis Reduces Lipopolysaccharide-induced Acute Lung Injury in Mice.
- Author:
Dong-Dong WU
;
Pin-Hua PAN
1
;
Ben LIU
;
Xiao-Li SU
;
Le-Meng ZHANG
;
Hong-Yi TAN
;
Zu CAO
;
Zuo-Ren ZHOU
;
Hai-Tao LI
;
Hao-Si LI
;
Li HUANG
;
Yuan-Yuan LI
Author Information
- Publication Type:Journal Article
- MeSH: Acute Lung Injury; chemically induced; prevention & control; Amino Acid Chloromethyl Ketones; pharmacology; Animals; Lipopolysaccharides; toxicity; Macrophages, Alveolar; drug effects; Male; Mice; Mice, Inbred C57BL; Oligopeptides; pharmacology; Pyroptosis; drug effects
- From: Chinese Medical Journal 2015;128(19):2638-2645
- CountryChina
- Language:English
-
Abstract:
BACKGROUNDPyroptosis is the term for caspase-1-dependent cell death associated with pro-inflammatory cytokines. The role of alveolar macrophage (AM) pyroptosis in the pathogenesis of the acute lung injury and acute respiratory distress syndrome (ALI/ARDS) remains unclear.
METHODSC57BL/6 wild-type mice were assigned to sham, lipopolysaccharide (LPS) + vehicle, LPS + acetyl-tyrosyl-valyl- alanyl-aspartyl-chloromethylketone (Ac-YVAD-CMK) and LPS + Z-Asp-Glu-Val-Asp-fluoromethylketone groups. Mice were given intraperitoneal (IP) injections of LPS. Drugs were IP injected 1 h before LPS administration. Mice were sacrificed 16 h after LPS administration, and AMs were isolated. Western blot analysis for active caspase-1 and cleaved caspase-3, evaluation of lung injury and a cytokine release analysis were performed. AMs were treated with LPS and adenosine triphosphate (ATP); caspase-1-dependent cell death was evaluated using flow cytometry; the apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) pyroptosomes were examined by immunofluorescence.
RESULTSThe expression of activated caspase-1 in AMs was enhanced following LPS challenge compared with the sham group. In the ex vivo study, the caspase-1/propidium iodide-positive cells, caspase-1 specks and ASC pyroptosomes were up-regulated in AMs following LPS/ATP stimulation. The specific caspase-1 inhibitor Ac-YVAD-CMK inhibited the activation of caspase-1 and pyroptotic cell death. Ac-YVAD-CMK also reduced the lung injury, pulmonary edema and total protein in bronchoalveolar lavage fluid (BALF). In addition, Ac-YVAD-CMK significantly inhibited interleukin-α2 (IL-1α2) release both in serum and BALF and reduced the levels of IL-18, tumor necrosis factor-α± (TNF-α±), High Mobility Group Box 1 (HMGB1) in BALF during LPS-induced ALI/ARDS.
CONCLUSIONSThis study reported AM pyroptosis during LPS-induced ALI/ARDS in mice and has demonstrated that Ac-YVAD-CMK can prevent AM-induced pyroptosis and lung injury. These preliminary findings may form the basis for further studies to evaluate this pathway as a target for prevention or reduction of ALI/ARDS.