Upregulation of eIF6 inhibits cardiac hypertrophy induced by phenylephrine

Biochem Biophys Res Commun. 2018 Jan 1;495(1):601-606. doi: 10.1016/j.bbrc.2017.11.046. Epub 2017 Nov 8.

Abstract

Cardiac hypertrophy is determined by an increase of cell size in cardiomyocytes (CMCs). Among the cellular processes regulating the growth of cell size, the increase of protein synthesis rate represents a critical event. Most of translational factors promoting protein synthesis stimulate cardiac hypertrophy. In contrast, activity of translational repressor factors, in cardiac hypertrophy, is not fully determined yet. Here we report the effect of a translational modulator, eIF6/p27BBP in the hypertrophy of neonatal rat CMCs. The increase of eIF6 levels surprisingly prevent the growth of cell size induced by phenylephrine, through a block of protein synthesis without affecting skeletal rearrangement and ANF mRNA expression. Thus, this work uncovers a new translational cardiac regulator independent by other well-known factors such as mTOR signalling or eIF2β.

Keywords: Cardiac hypertrophy; Cardiomyocytes; Cell signaling; Protein synthesis; Ribosomes; eIF6/p27(BBP).

MeSH terms

  • Animals
  • Animals, Newborn
  • Cardiomegaly
  • Cell Size / drug effects*
  • Cells, Cultured
  • Eukaryotic Initiation Factors / metabolism*
  • Muscle Cells / drug effects*
  • Muscle Cells / metabolism*
  • Muscle Cells / pathology
  • Phenylephrine*
  • Rats
  • Up-Regulation / drug effects

Substances

  • EIF6 protein, rat
  • Eukaryotic Initiation Factors
  • Phenylephrine