Silencing Angiopoietin-Like Protein 4 (ANGPTL4) Protects Against Lipopolysaccharide-Induced Acute Lung Injury Via Regulating SIRT1 /NF-kB Pathway

• Published in: Journal of cellular physiology Vol. 230; no. 10; pp. 2390 - 2402
• Main Authors: Guo, Liang, Li, Shaoying, Zhao, Yunfeng, Qian, Pin, Ji, Fuyun, Qian, Lanlan, Wu, Xueling, Qian, Guisheng
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.10.2015; Wiley Subscription Services, Inc
• Subjects: Acute Lung Injury - chemically induced; Acute Lung Injury - genetics; Acute Lung Injury - metabolism; Angiopoietin-like 4 Protein; Angiopoietins - genetics; Animals; Bronchoalveolar Lavage Fluid - immunology; Disease Models, Animal; Gene Silencing; Inflammation - genetics; Inflammation - metabolism; Lentivirus; Lipopolysaccharides - pharmacology; Mice; NF-kappa B - metabolism; Signal Transduction - drug effects; Signal Transduction - genetics; Sirtuin 1 - genetics
• ISSN: 0021-9541; 1097-4652
• DOI: 10.1002/jcp.24969

Lung inflammation and alveolar epithelial cell death are critical events in the development and progression of acute lung injury (ALI). Although angiopoietin‐like protein 4 (ANGPTL4) participates in inflammation, whether it plays important roles in ALI and alveolar epithelial cell inflammatory injury remains unclear. We therefore investigated the role of angptl4 in lipopolysaccharide (LPS)‐induced ALI and the associated mechanisms. Lentivirus‐mediated short interfering RNA targeted to the mouse angptl4 gene (AngsiRNA) and a negative control lentivirus (NCsiRNA) were intranasally administered to mice. Lung inflammatory injury and the underlying mechanisms for regulation of angptl4 on the LPS‐induced ALI were subsequently determined. We reported that angptl4 levels were increased both in human alveolar epithelial A549 cells and lung tissues obtained from a mouse model of LPS‐induced ALI. Angptl4 expression was induced by LPS in alveolar epithelial cells, whereas LPS‐induced lung inflammation (neutrophils infiltration in the lung tissues, tumor necrosis factor α, interleukin 6), lung permeability (lung wet/dry weight ratio and bronchoalveolar lavage fluid (BALF) protein concentration), tissue damage (caspase3 activation), and mortality rates were attenuated in AngsiRNA‐treated mice. The inflammatory reaction (tumor necrosis factor α, interleukin 6) and apoptosis rates were reduced in AngsiRNA(h)‐treated A549 cells. Moreover, angptl4 promoted NF‐kBp65 expression and suppressed SIRT1 expression both in mouse lungs and A549 cells. Additionally, SIRT1 antagonist nicotinamide (NAM) attenuated the inhibitory effects of AngsiRNA both on LPS‐induced NF‐kBp65 expression and IL6 expression. These findings suggest that silencing angptl4 protects against LPS‐induced ALI via regulating SIRT1/NF‐kB signaling pathway. J. Cell. Physiol. 230: 2390–2402, 2015. © 2015 Wiley Periodicals, Inc.