Myocardial knockdown of mRNA-stabilizing protein HuR attenuates post-MI inflammatory response and left ventricular dysfunction in IL-10-null mice

FASEB J. 2010 Jul;24(7):2484-94. doi: 10.1096/fj.09-149815. Epub 2010 Mar 10.

Abstract

Prolonged inflammatory response is associated with left ventricular (LV) dysfunction and adverse remodeling following myocardial infarction (MI). IL-10 inhibits inflammation by suppressing HuR-mediated mRNA stabilization of proinflammatory cytokines. Here we report that following MI, IL-10(-/-) mice showed exaggerated LV dysfunction, fibrosis, and cardiomyocyte apoptosis. Short-hairpin RNA (shRNA)-mediated knockdown of HuR in the myocardium significantly reversed MI-induced LV dysfunctions and LV remodeling. HuR knockdown significantly reduced MI-induced cardiomyocyte apoptosis concomitant with reduced p53 expression. Moreover, HuR knockdown significantly reduced infarct size and fibrosis area, which in turn was associated with decreased TGF-beta expression. In vitro, stable knockdown of HuR in mouse macrophage cell line RAW 264.7 corroborated in vivo data and revealed reduced mRNA expression of TNF-alpha, TGF-beta, and p53 following LPS challenge, which was associated with a marked reduction in the mRNA stability of these genes. Taken together, our studies suggest that HuR is a direct target of IL-10, and HuR knockdown mimics anti-inflammatory effects of IL-10.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Surface / genetics*
  • Antigens, Surface / physiology
  • Cell Line
  • ELAV Proteins
  • ELAV-Like Protein 1
  • Inflammation / etiology
  • Inflammation / prevention & control*
  • Interleukin-10 / deficiency*
  • Interleukin-10 / physiology
  • Macrophages
  • Mice
  • Mice, Knockout
  • Myocardial Infarction / pathology*
  • Myocardium / metabolism
  • Myocardium / pathology*
  • RNA Stability
  • RNA, Small Interfering / pharmacology
  • RNA-Binding Proteins / genetics*
  • RNA-Binding Proteins / physiology
  • Ventricular Dysfunction, Left / prevention & control*

Substances

  • Antigens, Surface
  • ELAV Proteins
  • ELAV-Like Protein 1
  • ELAVL1 protein, human
  • RNA, Small Interfering
  • RNA-Binding Proteins
  • Interleukin-10