NF-κB-Regulated miR-99a Modulates Endothelial Cell Inflammation

Mediators Inflamm. 2016:2016:5308170. doi: 10.1155/2016/5308170. Epub 2016 Jun 14.

Abstract

Objective. The present study was performed to investigate the effects and mechanisms of miR-99a on LPS-induced endothelial cell inflammation, as well as the regulation of NF-κB on miR-99a production. Methods and Results. ELISA showed that LPS treatment significantly promoted the secretion of inflammatory factors (TNF-α, IL-6, IL-1β, and MCP-1). LPS treatment also inhibited miR-99a production and promoted mTOR expression and NF-κB nuclear translocation. Overexpression of miR-99a suppressed the LPS-induced TNF-α, IL-6, IL-1β, and MCP-1 overproduction, mTOR upregulation, and NF-κB nuclear translocation. The PROMO software analysis indicated NF-κB binding site in the -1643 to -1652 region of miR-99a promoter. Dual luciferase reporter analysis, electrophoretic mobility shift assays (EMSA), and chromosome immunoprecipitation (ChIP) assays demonstrated that NF-κB promoted the transcription of miR-99a by binding to the -1643 to -1652 region of miR-99a promoter. Further studies on HUVECs verified the regulatory effects of NF-κB on miR-99a production. Conclusion. MiR-99a inhibited the LPS-induced HUVECs inflammation via inhibition of the mTOR/NF-κB signal. NF-κB promoted miR-99a production by binding to the -1643 to -1652 region of miR-99a promoter. Considering the importance of endothelial inflammation on cardiovascular diseases, such as atherosclerosis, our results may provide a new insight into the pathogenesis and therapy of atherosclerosis.

MeSH terms

  • Binding Sites
  • Chemokine CCL2 / metabolism
  • Endothelial Cells / drug effects
  • Endothelial Cells / metabolism
  • Enzyme-Linked Immunosorbent Assay
  • HEK293 Cells
  • Histones / metabolism
  • Human Umbilical Vein Endothelial Cells / drug effects
  • Human Umbilical Vein Endothelial Cells / metabolism*
  • Humans
  • Inflammation / metabolism
  • Interleukin-6 / metabolism
  • Lipopolysaccharides / pharmacology
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • NF-kappa B / metabolism*
  • Polymerase Chain Reaction
  • Promoter Regions, Genetic / genetics
  • TOR Serine-Threonine Kinases / metabolism
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Chemokine CCL2
  • Histones
  • Interleukin-6
  • Lipopolysaccharides
  • MIRN99 microRNA, human
  • MicroRNAs
  • NF-kappa B
  • Tumor Necrosis Factor-alpha
  • TOR Serine-Threonine Kinases