title: [Effect of transfection of microRNA-146a on expression of tumor necrosis factor-a in alveolar macrophages].
abstract: OBJECTIVE
  To observe the effect of transfected microRNA-146a (miR-146a) on expression of tumor necrosis factor-alpha ( TNF-alpha ) in alveolar macrophages, and to analyze its regulatory mechanism in the inflammatory response of alveolar macrophages.
  
  
  METHODS
  Cy.11113 labeled with 25, 50, 100 nmol/L of Pre-miR", respectively, were transfected into rat alveolar macrophages NR8383 cultured in vitro. The highest transfection efficiency was selected to he the experimental concentration. NR8383 cells were divided into two groups: transfected group was tranfected with 50 nmol/L Pre-miR1111 miR-146a precursor, and control group with SO nmol/L Cym3 labeled Pre-miR1" as the negative control. The mRNA expression of miR-146a of cells was detected hy real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR). Then cells were stimulated with lipopolysaccharide (LPS, 1 mg/L) for 6 hours. The production of TNF-alpha protein in the supernatant of cells was assayed by enzyme-linked immunosorhent assay (ELISA) , and the expression of TNF-alpha mRNA of cells was detected hy RT-qPCR.
  
  
  RESULTS
  Transfection rate was highest in the 50 nmol/L Cy11113 labeled Pre-miR"' cells, and it reached 80%. Compared with control group (set at 1), the expression of miR-146a increased by (24.55 ±6.14) folds in transfected alveolar marrophages (P<0.01). After the cells were stimulated with LPS, the production of TNF-alpha protein (ng/L) in the supernatant of cell was decreased from 616.6 ± 42.3 to 211.5 ± 30.4 (P<0.01), and the expression of TNF-alpha mRNA was decreased by (47 ± 6) % (P<0.05) in transfected alveolar macrophages when compared with that of the control.
  
  
  CONCLUSIONS
  Transfection alveolar macrophages with miR-146a precursors could down-regulate the expression of TNF-alpha. It is therefore suggests that up-regulation of miR-146a can inhibit inflammatory responses as induced hy LPS, in alveolar macrophages.
authors.affiliation: Department of Critical Care Medicine, the First Affiliated Hospital of Nanchang University, Jiangxi, China.
authors.forename: Fen
authors.initials: F
authors.lastname: Liu
authors.forename: Zhen-guo
authors.initials: ZG
authors.lastname: Zeng
authors.forename: Cheng
authors.initials: C
authors.lastname: Nie
authors.forename: Cheng-zhi
authors.initials: CZ
authors.lastname: Ding
authors.forename: Qiang
authors.initials: Q
authors.lastname: Shao
authors.forename: Cheng
authors.initials: C
authors.lastname: Qing
authors.forename: Ke-jian
authors.initials: KJ
authors.lastname: Qizn
mesh_terms: D000818:Animals; D002460:Cell Line; D016676:Macrophages, Alveolar / Q000378:metabolism*; D035683:MicroRNAs / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: C554180:MIRN146 microRNA, rat; D035683:MicroRNAs; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha