title: Identification and characterization of poly(I:C)-induced molecular responses attenuated by nicotine in mouse macrophages.
abstract: To further our understanding of the effects of nicotine on the molecular responses of macrophages during virus or virus-like infections, poly(I:C)-stimulated macrophage-like RAW264.2 cells or mouse primary peritoneal macrophages were challenged with nicotine; and their molecular responses were evaluated using a qRT-PCR array, antibody array, ELISA, Western blotting, and Ca(2+) imaging. Of 51 genes expressed in the Toll-like receptor (TLR) and RIG-I-like receptor (RLR) pathways, mRNA expression of 15 genes in RAW264.7 cells was attenuated by nicotine, of which mRNA expression of IL-6, TNF-α, and IL-1β was confirmed to be attenuated in peritoneal macrophages. Concurrently, nicotine treatment attenuated the release of IL-6 and TNF-α from poly(I:C)-stimulated macrophages. However, when poly(I:C)-stimulated macrophages were challenged with nicotine plus α-bungarotoxin (α-BTX), secretion of IL-6 and TNF-α was found to be in a level seen with poly(I:C) stimulation only, indicating that α7-nAChR, a highly Ca(2+) permeable ion channel sensitive to blockade by α-BTX, is involved in this process. Furthermore, results from an antibody array indicated that nicotine treatment attenuated the phosphorylation of 82 sites, including Thr286 on CaMKIIα, from poly(I:C)-stimulated RAW264.7 cells, of which 28 are expressed in the downstream cascade of Ca(2+) signaling. Coincidentally, poly(I:C)-stimulated macrophages showed attenuated expression of phosphorylated CaMKIIα when pretreated with nicotine. In addition, nicotine attenuated intracellular Ca(2+) signal from poly(I:C)-stimulated RAW264.7 cells. Collectively, these results indicate that poly(I:C)-induced molecular responses of macrophages could be significantly attenuated by nicotine.
authors.affiliation: Department of Psychiatry and Neurobehavioral Sciences University of Virginia 1670 Discovery Drive, Suite 110, Charlottesville, VA 22911, USA.
authors.forename: Wen-Yan
authors.initials: WY
authors.lastname: Cui
authors.forename: Shufang
authors.initials: S
authors.lastname: Zhao
authors.forename: Renata
authors.initials: R
authors.lastname: Polanowska-Grabowska
authors.forename: Ju
authors.initials: J
authors.lastname: Wang
authors.forename: Jinxue
authors.initials: J
authors.lastname: Wei
authors.forename: Bhagirathi
authors.initials: B
authors.lastname: Dash
authors.forename: Sulie L
authors.initials: SL
authors.lastname: Chang
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Saucerman
authors.forename: Jun
authors.initials: J
authors.lastname: Gu
authors.forename: Ming D
authors.initials: MD
authors.lastname: Li
mesh_terms: D000818:Animals; D002038:Bungarotoxins / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000378:metabolism; D002460:Cell Line; D053487:DEAD-box RNA Helicases / Q000235:genetics; D020869:Gene Expression Profiling; D007113:Immunity, Innate / Q000235:genetics; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009538:Nicotine / Q000494:pharmacology*; D010766:Phosphorylation; D011070:Poly I-C / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D011978:Receptors, Nicotinic / Q000378:metabolism; D015398:Signal Transduction; D051193:Toll-Like Receptors / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism; D014777:Virus Diseases / Q000276:immunology / Q000378:metabolism; D064569:alpha7 Nicotinic Acetylcholine Receptor
chemical_list: D002038:Bungarotoxins; C579166:Chrna7 protein, mouse; D015850:Interleukin-6; D012333:RNA, Messenger; D011978:Receptors, Nicotinic; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha; D064569:alpha7 Nicotinic Acetylcholine Receptor; D009538:Nicotine; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D053487:DEAD-box RNA Helicases; D011070:Poly I-C; D002118:Calcium