Expression Profile of Mouse , Nuclear-Encoded Humanin-Like Gene.

BACKGROUND

Mitochondrial-derived peptides (MDPs) such as MOTS-c and humanin have been studied for their cytoprotective functions. In mice, humanin-encoding is a mitochondrial pseudogene, and the humanin-like peptide is encoded by the nuclear gene. However, endogenous tissue-specific expression profiles of have not yet been identified.

METHODS

and expression was profiled via reverse transcription using only oligo(dT) primers from tissues of C57BL6/J mice. To analyze altered expression upon mitochondrial biogenesis, C2C12 myocytes and brown adipocytes were differentiated. Mitochondrial DNA copy numbers were quantified for normalization.

RESULTS

Both and were highly expressed in brown adipose tissue. When normalized against mitochondrial content, was identified as being highly expressed in the duodenum, followed by the jejunum. In models of mitochondrial biogenesis, both and were upregulated during myocyte and brown adipocyte differentiation. Increased expression during brown adipocyte differentiation remained significant after normalization against mitochondrial DNA copy number, whereas myocyte differentiation exhibited biphasic upregulation and downregulation in early and late phases, respectively.

CONCLUSION

Nuclear-encoded showed similar expression patterns of mitochondrial-encoded . Brown adipose tissue presented the highest basal expression levels of and . When normalized against mitochondrial DNA copy number, gut tissues exhibited the highest expression of . Upregulation of during mitochondrial biogenesis is independent of mitochondrial content.