Functional screening of mammalian mechanosensitive genes using Drosophila RNAi library-Smarcd3/Bap60 is a mechanosensitive pro-inflammatory gene

• Authors: Sandeep Kumar, Emory University; In-hwan Jang, Georgia Institute of Technology; Chan Woo Kim, Georgia Institute of Technology; Dong-Won Kang, Georgia Institute of Technology; Won Jae Lee, Seoul National University; Hanjoong Jo, Emory University
• Journal Title: Scientific Reports
• Volume: Volume 6
• Publisher: Nature Publishing Group: Open Access Journals - Option C | 2016-11-07, Pages 36461-36461
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1038/srep36461
• Subjects: Health Sciences, Medicine and Surgery; Engineering, Biomedical
• Keywords: Science & Technology; Multidisciplinary Sciences; Science & Technology - Other Topics; ENDOTHELIAL-CELLS; DISTURBED FLOW; SHEAR-STRESS; IMMUNE-RESPONSE; HOST-DEFENSE; ACTIVATION; ATHEROSCLEROSIS; EXPRESSION; MELANOGASTER; DYSFUNCTION

Abstract

Disturbed blood flow (d-flow) induces atherosclerosis by altering the expression of mechanosensitive genes in the arterial endothelium. Previously, we identified >580 mechanosensitive genes in the mouse arterial endothelium, but their role in endothelial inflammation is incompletely understood. From this set, we obtained 84 Drosophila RNAi lines that silences the target gene under the control of upstream activation sequence (UAS) promoter. These lines were crossed with C564-GAL4 flies expressing GFP under the control of drosomycin promoter, an NF-? B target gene and a marker of pathogen-induced inflammation. Silencing of psmd12 or ERN1 decreased infection-induced drosomycin expression, while Bap60 silencing significantly increased the drosomycin expression. Interestingly, knockdown of Bap60 in adult flies using temperature-inducible Bap60 RNAi (C564 ts -GAL4-Bap60-RNAi) enhanced drosomycin expression upon Gram-positive bacterial challenge but the basal drosomycin expression remained unchanged compared to the control. In the mammalian system, smarcd3 (mammalian ortholog of Bap60) expression was reduced in the human- and mouse aortic endothelial cells exposed to oscillatory shear in vitro as well as in the d-flow regions of mouse arterial endothelium in vivo. Moreover, siRNA-mediated knockdown of smarcd3 induced endothelial inflammation. In summary, we developed an in vivo Drosophila RNAi screening method to identify flow-sensitive genes that regulate endothelial inflammation.