New gene targets of PGC-1α and ERRα co-regulation in C2C12 myotubes

Mol Biol Rep. 2014 Dec;41(12):8009-17. doi: 10.1007/s11033-014-3698-0. Epub 2014 Sep 6.

Abstract

As a transcriptional coactivator, PGC-1α contributes to the regulation of a broad range of metabolic processes in skeletal muscle health and disease; however, there is limited information about the genes it transcriptionally regulates. To identify new potential gene targets of PGC-1α regulation, mouse C2C12 myotubes were screened by microarray analysis following PGC-1α overexpression. Genes with an mRNA expression of 2.5-fold or more (P < 0.001) were identified. From these, further genes were singled out if they had no previous connection to PGC-1α regulation or characterization in skeletal muscle, or were unannotated with no known function. Following confirmation of their regulation by PGC-1α using qPCR analysis, eight genes were focused on for further investigation (Akr1b10, Rmnd1, 1110008P14Rik, 1700021F05Rik, Mtfp1, Mrm1, Oxnad1 and Cluh). Bioinformatics indicated a number of the genes were linked to a range of metabolic-related functions including fatty acid oxidation, oxido-reductase activity, and mitochondrial remodeling and transport. Treating C2C12 myotubes for 6 h with AICAR, a known activator of AMP kinase and inducer of Pgc-1α gene expression, increased the mRNA levels of both Pgc-1α (P < 0.001) and of Mtfp1, Mrm1, Oxnad1 and Cluh (P < 0.05). Screening of the promoter and intron 1 regions also revealed all genes to contain either a consensus or near consensus response elements for the estrogen-related receptor α (ERRα), a key transcription factor-binding partner of PGC-1α in skeletal muscle. Furthermore, knockdown of endogenous ERRα levels partially or completely blocked the induction of gene expression of all genes by PGC-1α, while each gene was significantly upregulated in the presence of a constitutively active form of ERRα (P < 0.05) except for Akr1b10. These findings provide preliminary evidence for the novel regulation of these genes by PGC-1α and its signaling pathway in skeletal muscle.

MeSH terms

  • Animals
  • ERRalpha Estrogen-Related Receptor
  • Gene Expression Regulation*
  • Humans
  • Mice
  • Microarray Analysis
  • Muscle Fibers, Skeletal / metabolism*
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • Receptors, Estrogen / genetics
  • Receptors, Estrogen / metabolism*
  • Response Elements
  • Signal Transduction
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transgenes
  • Up-Regulation*

Substances

  • PPARGC1A protein, human
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • Receptors, Estrogen
  • Transcription Factors