β-Arrestin2 Inhibits Expression of Inflammatory Cytokines in BEAS-2B Lung Epithelial Cells Treated with Cigarette Smoke Condensate via Inhibition of Autophagy

• Main Authors: Yanjun Wu, Yunxiao Li, Bo Wu, Chunting Tan, Xin He, Bo Xu, Ganggang Yu, Haoyan Wang
• Format: Article
• Language: English
• Published: Cell Physiol Biochem Press GmbH & Co KG 2018-10-01
• Series: Cellular Physiology and Biochemistry
• Subjects: β-Arrestin2; Cigarette smoke; Inflammation; Autophagy; Chronic obstructive pulmonary disease
• Online Access: https://www.karger.com/Article/FullText/494586

Background/Aims: β-arrestin2 has been shown to have a role in human inflammatory disease. However, the role of β-arrestin2 in cigarette smoke-induced inflammation in the lung remains unknown. The aims of this study were to investigate the effects of β-arrestin2 on cigarette smoke condensate (CSC)-induced expression of inflammatory cytokines in the BEAS-2B human bronchial epithelial cell line in vitro, and the mechanisms involved. Methods: The MTT assay determined cell viability of cultured BEAS-2B cells. Autophagy was assessed by western blot, adenoviral mRFP-GFP-LC3 transfection, and immunofluorescence. The effects of β-arrestin2 shRNA knockdown were studied by western blot and real-time reverse transcription-polymerase chain reaction (RT-PCR). Western blot evaluated the AMPK/mTOR signaling pathway. Levels of inflammatory cytokines, interleukin (IL)-6, IL-8, and MCP-1 were measured in cell culture supernatants by enzyme-linked immunosorbent assay (ELISA). Results: CSC suppressed expression of β-arrestin2 in BEAS-2B cells, activated the AMPK/mTOR signaling pathway, increased cell autophagy and the expression of IL-6, IL-8, and MCP-1,pretreatment with the β-arrestin2 biased ligands, propranolol, and ICI118551 reversed these changes. Inhibition of autophagy reduced the expression of inflammatory cytokines following CSC. Conclusion: In the human bronchial epithelial cell line, BEAS-2B, β-arrestin2 reduced the expression of CSC-induced inflammatory cytokines by inhibiting autophagy, most likely via the AMPK/mTOR signaling pathway.