title: 14,15-Epoxyeicosatrienoic acid suppresses cigarette smoke condensate-induced inflammation in lung epithelial cells by inhibiting autophagy.
abstract: Epoxyeicosatrienoic acids (EETs) are metabolic products of free arachidonic acid, which are produced through cytochrome P-450 (CYP) epoxygenases. EETs have anti-inflammatory, antiapoptotic, and antioxidative activities. However, the effect of EETs on cigarette smoke-induced lung inflammation is not clear. Autophagy is believed to be involved in the pathogenesis of chronic obstructive pulmonary disease. In addition, nuclear erythroid-related factor 2 (Nrf2), a transcription factor that regulates many antioxidant genes, is thought to regulate antioxidant defenses in several lung diseases. In addition, interaction between EETs, autophagy, and Nrf2 has been reported. The aim of this study was to explore the effect of 14,15-EET on cigarette smoke condensate (CSC)-induced inflammation in a human bronchial epithelial cell line (Beas-2B), and to determine whether the underlying mechanisms involved in the regulation of Nrf2 through inhibition of autophagy. Autophagy and expression of autophagy signaling pathway proteins (LC3B, p62, PI3K, Akt, p-Akt, and p-mTOR) and anti-inflammatory proteins (Nrf2 and HO-1) were assessed via Western blot analysis. Autophagosomes and autolysosomes were detected by adenoviral mRFP-GFP-LC3 transfection. Inflammatory factors (IL-6, IL-8, and MCP-1) were detected by ELISA. Lentiviral vectors carrying p62 short hairpin RNA were used to interfere with p62 expression to evaluate the effect of p62 on Nrf2 expression. Nrf2 expression was determined through immunocytochemistry. 14,15-EET treatment resulted in a significant reduction in IL-6, IL-8, and MCP-1 secretion, and increased accumulation of Nrf2 and expression of HO-1. In addition, 14,15-EET inhibited CSC-induced autophagy in Beas-2B cells. The mechanism of the anti-inflammatory effect of 14,15-EET involved inhibition of autophagy and an increase in p62 levels, followed by translocation of Nrf2 into the nucleus, which then upregulated expression of the antioxidant enzyme HO-1. 14,15-EET protects against CSC-induced lung inflammation by promoting accumulation of Nrf2 via inhibition of autophagy.
authors: Department of Respiratory Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, China; and.
authors: Yunxiao
authors: Y
authors: Li
authors: Department of Respiratory Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, China; and.
authors: Ganggang
authors: G
authors: Yu
authors: Beijing Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors: Shaopeng
authors: S
authors: Yuan
authors: Department of Respiratory Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, China; and.
authors: Chunting
authors: C
authors: Tan
authors: Beijing Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors: Jianlin
authors: J
authors: Xie
authors: Beijing Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors: Yasi
authors: Y
authors: Ding
authors: Beijing Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors: Puqiao
authors: P
authors: Lian
authors: Beijing Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors: Lixia
authors: L
authors: Fu
authors: Beijing Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors: Qi
authors: Q
authors: Hou
authors: Department of Respiratory Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, China; and.
authors: Bo
authors: B
authors: Xu
authors: Department of Respiratory Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, China; and haoyanw@ccmu.edu.cn.
authors: Haoyan
authors: H
authors: Wang
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D001343:Autophagy / Q000187:drug effects*; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D004847:Epithelial Cells / Q000473:pathology*; D055785:Gene Knockdown Techniques; D051547:Heme Oxygenase-1 / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000473:pathology*; D018836:Inflammation Mediators / Q000378:metabolism; D008168:Lung / Q000473:pathology*; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D016601:RNA-Binding Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D012907:Smoking / Q000009:adverse effects*; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D015126:8,11,14-Eicosatrienoic Acid; D000893:Anti-Inflammatory Agents; D051547:Heme Oxygenase-1; D018836:Inflammation Mediators; D051267:NF-E2-Related Factor 2; D019869:Phosphatidylinositol 3-Kinases; D016601:RNA-Binding Proteins; D058570:TOR Serine-Threonine Kinases; C118585:P62 protein, human; C046782:14,15-epoxy-5,8,11-eicosatrienoic acid
keywords: Nrf2; autophagy; cigarette smoke-induced inflammation; epoxyeicosatrienoic acids