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Mol Biol Rep (2014) 41:80098017 DOI 10.1007/s11033-014-3698-0
New gene targets of PGC-1a and ERRa co-regulation in C2C12 myotubes
Abena Nsiah-Sefaa Erin L. Brown
Aaron P. Russell Victoria C. Foletta
Received: 31 May 2014 / Accepted: 23 August 2014 / Published online: 6 September 2014 Springer Science+Business Media Dordrecht 2014
Abstract As a transcriptional coactivator, PGC-1a 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-1a regulation, mouse C2C12 myotubes were screened by microarray analysis following PGC-1a overexpression. Genes with an mRNA expression of 2.5-fold or more (P \ 0.001) were identied. From these, further genes were singled out if they had no previous connection to
PGC-1a regulation or characterization in skeletal muscle, or were unannotated with no known function. Following conrmation of their regulation by PGC-1a 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-1a gene expression, increased the mRNA levels of both Pgc-1a (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 a (ERRa), a key transcription factor-binding partner of PGC-1a in skeletal muscle. Furthermore, knockdown of endogenous ERRa levels partially or completely blocked the induction of gene expression of all genes by PGC-1a, while each gene was signicantly upregulated in the presence of a constitutively active form of ERRa (P \ 0.05) except for Akr1b10. These ndings provide preliminary evidence for the novel regulation of these genes by PGC-1a and its signaling pathway in skeletal muscle.
Keywords Peroxisome proliferator-activated receptor gamma, coactivator 1-alpha (PGC-1a) C2C12 myotubes
5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) Estrogen-related receptor alpha (ERRa)
Bioinformatics
Introduction
The peroxisome proliferator-activated receptor (PPAR) gamma, coactivator 1-alpha (PGC-1a) protein is a key molecular switch in the...