title: p47phox and reactive oxygen species production modulate expression of microRNA-451 in macrophages.
abstract: The production of microRNAs (miRNA) is influenced by various stimuli, including environmental stresses. We hypothesized that reactive oxygen species (ROS)-associated stress could regulate macrophage miRNA synthesis. miRNAs undergo unique steps of maturation processing through either one of two pathways of cytoplasmic processing. Unlike the canonical pathway, the regulation of alternative cytoplasmic processing of miRNA has not been fully elucidated yet. We cultured bone marrow derived macrophages (BMDM) from wild type (WT) and p47(phox-/-) mice and profiled miRNA expression using microarrays. We analyzed 375 miRNAs including four endogenous controls to normalize the data. At resting state, p47(phox-/-) BMDM has the markedly reduced expression of miR-451 compared to WT BMDM, without other significant differences. Unlike majority of miRNAs, miR-451 goes through the unique alternative processing pathway, in which Ago2 plays a key role. In spite of significant reduction of mature miR-451, however, its precursor form, pre-mir-451, was similar in both BMDMs, suggesting that the processing of pre-mir-451 is impaired in p47(phox-/-) BMDM. Moreover, p47(phox-/-) BMDM expressed significantly reduced level of Ago2. In contrast, Ago2 mRNA levels were similar in WT and p47(phox-/-) BMDM, suggesting a post-transcriptional defect of Ago2 production in p47(phox-/-) macrophages, which resulted in impaired processing of pre-miR-451. In order to examine the functional significance of miR-451 in macrophages, we cultured BMDMs from miR-451 knock-out mice. Of interest, miR-451-deficient BMDM exhibited reduced ROS generation upon zymosan stimulation, compared to WT BMDM. Our studies suggest functional crosstalk between ROS and miR-451 in the regulation of macrophage oxidant stress.
authors.affiliation: Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois , Chicago, IL , USA.
authors.forename: R
authors.initials: R
authors.lastname: Ranjan
authors.forename: Y G
authors.initials: YG
authors.lastname: Lee
authors.forename: M
authors.initials: M
authors.lastname: Karpurapu
authors.forename: M A
authors.initials: MA
authors.lastname: Syed
authors.forename: S
authors.initials: S
authors.lastname: Chung
authors.forename: J
authors.initials: J
authors.lastname: Deng
authors.forename: J J
authors.initials: JJ
authors.lastname: Jeong
authors.forename: G
authors.initials: G
authors.lastname: Zhao
authors.forename: L
authors.initials: L
authors.lastname: Xiao
authors.forename: R T
authors.initials: RT
authors.lastname: Sadikot
authors.forename: M J
authors.initials: MJ
authors.lastname: Weiss
authors.forename: J W
authors.initials: JW
authors.lastname: Christman
authors.forename: G Y
authors.initials: GY
authors.lastname: Park
mesh_terms: D000818:Animals; D060565:Argonaute Proteins / Q000378:metabolism; D002460:Cell Line; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D019255:NADPH Oxidases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: C526735:Ago2 protein, mouse; D060565:Argonaute Proteins; D035683:MicroRNAs; C550758:Mirn451 microRNA, mouse; D017382:Reactive Oxygen Species; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1
keywords: NADPH oxidase; macrophages; microRNA; p47phox; reactive oxygen species; stress