The modulation of MiR-155 and MiR-23a manipulates Klebsiella pneumoniae Adhesion on Human pulmonary Epithelial cells via Integrin α5β1 Signaling

Sci Rep. 2016 Aug 18:6:31918. doi: 10.1038/srep31918.

Abstract

Micro-RNAs (miRNAs) critically regulate several host defense mechanisms, but their roles in the bacteria-epithelium interplay remain unclear. Our results displayed that the expression of miR-155 and miR-23a were down-regulated in K. pneumoniae-infected pulmonary epithelial cells. The elevated bacterial adhesion on A549 cells followed the enhancement of the cellular levels of these two miRNAs. Meanwhile, a mechanistic study demonstrated that miR-155 promoted integrin α5β1 function and resulted in the increased actin polymerization. Moreover, a non-histone nuclear protein, high mobility group nucleosomal-binding domain 2 (HMGN2) served as the potential target of miR-155 and miR-23a to regulate the integrin α5β1 expression and K. pneumoniae adhesion. Furthermore, the expression of a known integrin transcription suppressor-Nuclear Factor-I (NFI) was also repressed by miR-155, which paralleled with its chromatin location in the promoter regions of integrin α5 and β1. These results uncover novel links between miRNAs and integrin function to regulate bacterial adhesion, indicating a potential mechanism of host cell autonomous immune response to K. pneumoniae infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alveolar Epithelial Cells / metabolism*
  • Bacterial Adhesion*
  • Cell Line
  • Down-Regulation
  • Humans
  • Integrin alpha5beta1 / metabolism*
  • Klebsiella Infections / metabolism*
  • Klebsiella pneumoniae / metabolism*
  • MicroRNAs / metabolism*
  • Signal Transduction

Substances

  • Integrin alpha5beta1
  • MIRN155 microRNA, human
  • MIRN23a microRNA, human
  • MicroRNAs