Kim Jihye, Choi Jong-Whan, Namkung Jun
Department of Biochemistry, Yonsei University Wonju College of Medicine, Wonju, Korea.
J Lifestyle Med. 2021 Jan 31;11(1):13-22. doi: 10.15280/jlm.2021.11.1.13.
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.
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.
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.
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.
线粒体衍生肽（MDPs），如 MOTS-c 和人胰岛素，因其细胞保护功能而受到研究。在小鼠中，编码人胰岛素的是一个线粒体假基因，而类人胰岛素肽由核基因编码。然而，尚未确定其在组织中的内源性特异性表达谱。
使用仅含寡聚（dT）引物的逆转录方法，对 C57BL6/J 小鼠组织中的 和 表达进行分析。为了分析线粒体生物合成过程中表达的变化，对 C2C12 肌细胞和棕色脂肪细胞进行分化培养。对线粒体 DNA 拷贝数进行定量以进行标准化。
和 在棕色脂肪组织中均高表达。以线粒体含量进行标准化后， 在十二指肠中高表达，其次是空肠。在线粒体生物合成模型中， 在肌细胞和棕色脂肪细胞分化过程中均上调。棕色脂肪细胞分化过程中 的表达增加，在以线粒体 DNA 拷贝数进行标准化后仍具有显著性，而肌细胞分化在早期和晚期分别表现出双相上调和下调。
核编码的 显示出与线粒体编码的 相似的表达模式。棕色脂肪组织中 和 的基础表达水平最高。以线粒体 DNA 拷贝数进行标准化后，肠道组织中 的表达最高。线粒体生物合成过程中 的上调与线粒体含量无关。
