miR-146a polymorphism influences levels of miR-146a, IRAK-1, and TRAF-6 in young patients with coronary artery disease

Cell Biochem Biophys. 2014 Mar;68(2):259-66. doi: 10.1007/s12013-013-9704-7.

Abstract

Modulation of nuclear factor KappaB (NF-κB) activation may play a role in regulating inflammatory conditions associated with coronary artery disease (CAD). MicroRNA-146a (miR-146a) primarily targets interleukin-1 receptor-associated kinase 1 (IRAK-1) and tumour necrosis factor receptor associated factor 6 (TRAF-6), which results in inhibition of NF-κB via the TLR pathway. This study investigated the influence of the miR-146a GC rs2910164 on miR-146a expression in young South African Indians with CAD. CAD patients and controls were genotyped by PCR-RFLP and miRNA-146a levels were measured by qPCR. IRAK-1, TRAF-6 and NF-κB expression was determined by Western blot. No differences in genotypic frequency was found (GG: 45 vs. 47%, GC: 46 vs. 41%, CC: 9 vs. 12%) in controls and patients respectively (odds ratio = 1.025; 95% confidence interval 0.6782-1.550; p = 0.9164). Significantly higher levels of miR-146a was associated with CAD patients with the CC genotype (6.25-fold increase relative to controls and patients with the wildtype variant, p < 0.0001). Significantly lower levels of IRAK-1 (0.38 ± 0.02; p = 0.0072) and TRAF-6 (0.44 ± 0.02; p = 0.0146) was found in CAD patients with the CC genotype. The lowest levels of NF-κB and C-reactive protein were found in patients with the homozygous C allele compared to the heterozygous GC and wildtype variants. We propose a role for miR-146a in TLR signalling through a negative feedback mechanism involving the attenuation of NF-κB by down-regulation of IRAK-1 and TRAF-6. Our observations implicate miR-146a as a target for lowering inflammation in CAD patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Alleles
  • C-Reactive Protein / analysis
  • Coronary Artery Disease / genetics*
  • Coronary Artery Disease / metabolism
  • Coronary Artery Disease / pathology
  • Down-Regulation
  • Genotype
  • Homozygote
  • Humans
  • Interleukin-1 Receptor-Associated Kinases / genetics
  • Interleukin-1 Receptor-Associated Kinases / metabolism*
  • Male
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • NF-kappa B / genetics
  • NF-kappa B / metabolism
  • Odds Ratio
  • Polymorphism, Genetic*
  • RNA, Messenger / metabolism
  • TNF Receptor-Associated Factor 6 / genetics
  • TNF Receptor-Associated Factor 6 / metabolism*

Substances

  • MIRN146 microRNA, human
  • MicroRNAs
  • NF-kappa B
  • RNA, Messenger
  • TNF Receptor-Associated Factor 6
  • C-Reactive Protein
  • Interleukin-1 Receptor-Associated Kinases