Activated Integrin-Linked Kinase Negatively Regulates Muscle Cell Enhancement Factor 2C in C2C12 Cells

Biomed Res Int. 2015:2015:748470. doi: 10.1155/2015/748470. Epub 2015 Dec 16.

Abstract

Our previous study reported that muscle cell enhancement factor 2C (MEF2C) was fully activated after inhibition of the phosphorylation activity of integrin-linked kinase (ILK) in the skeletal muscle cells of goats. It enhanced the binding of promoter or enhancer of transcription factor related to proliferation of muscle cells and then regulated the expression of these genes. In the present investigation, we explored whether ILK activation depended on PI3K to regulate the phosphorylation and transcriptional activity of MEF2C during C2C12 cell proliferation. We inhibited PI3K activity in C2C12 with LY294002 and then found that ILK phosphorylation levels and MEF2C phosphorylation were decreased and that MCK mRNA expression was suppressed significantly. After inhibiting ILK phosphorylation activity with Cpd22 and ILK-shRNA, we found MEF2C phosphorylation activity and MCK mRNA expression were increased extremely significantly. In the presence of Cpd22, PI3K activity inhibition increased MEF2C phosphorylation and MCK mRNA expression indistinctively. We conclude that ILK negatively and independently of PI3K regulated MEF2C phosphorylation activity and MCK mRNA expression in C2C12 cells. The results provide new ideas for the study of classical signaling pathway of PI3K-ILK-related proteins and transcription factors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Cell Proliferation / genetics
  • Creatine Kinase, MM Form / biosynthesis*
  • Creatine Kinase, MM Form / genetics
  • Gene Expression Regulation / genetics*
  • MEF2 Transcription Factors / biosynthesis
  • MEF2 Transcription Factors / genetics*
  • Mice
  • Muscle Cells / metabolism
  • Phosphatidylinositol 3-Kinases / genetics
  • Phosphorylation
  • Protein Serine-Threonine Kinases / biosynthesis*
  • Protein Serine-Threonine Kinases / genetics
  • RNA, Messenger / biosynthesis
  • Signal Transduction
  • Transcriptional Activation / genetics

Substances

  • MEF2 Transcription Factors
  • RNA, Messenger
  • integrin-linked kinase
  • Protein Serine-Threonine Kinases
  • Creatine Kinase, MM Form