Ji Yuhua, Zhang Jinsheng, Wang Wenwen, Ji Juling
Key Laboratory of Neuroregeneration, Nantong University, Nanton, China.
Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, PR China.
PLoS One. 2014 Sep 29;9(9):e108351. doi: 10.1371/journal.pone.0108351. eCollection 2014.
We previous reported that miR-27a regulates lipid metabolism and cell proliferation during hepatic stellate cells (HSCs) activation. To further explore the biological function and underlying mechanisms of miR-27a in HSCs, global protein expression affected by overexpression of miR-27a in HSCs was analyzed by a cleavable isotope-coded affinity tags (cICAT) based comparative proteomic approach. In the present study, 1267 non-redundant proteins were identified with unique accession numbers (score ≥1.3, i.e. confidence ≥95%), among which 1171 were quantified and 149 proteins (12.72%) were differentially expressed with a differential expression ratio of 1.5. We found that up-regulated proteins by miR-27a mainly participate in cell proliferation and myogenesis, while down-regulated proteins were the key enzymes involved in de novo lipid synthesis. The expression of a group of six miR-27a regulated proteins was validated and the function of one miR-27a regulated protein was further validated. The results not only delineated the underlying mechanism of miR-27a in modulating fat metabolism and cell proliferation, but also revealed a novel role of miR-27a in promoting myogenic tans-differentiation during HSCs activation. This study also exemplified proteomics strategy as a powerful tool for the functional study of miRNA.
我们之前报道过，miR-27a在肝星状细胞（HSCs）激活过程中调节脂质代谢和细胞增殖。为了进一步探究miR-27a在HSCs中的生物学功能及潜在机制，我们采用基于可切割同位素编码亲和标签（cICAT）的比较蛋白质组学方法，分析了miR-27a过表达对HSCs中整体蛋白质表达的影响。在本研究中，共鉴定出1267个具有唯一登录号的非冗余蛋白质（得分≥1.3，即置信度≥95%），其中1171个被定量，149个蛋白质（12.72%）差异表达，差异表达倍数为1.5。我们发现，miR-27a上调的蛋白质主要参与细胞增殖和肌生成，而下调的蛋白质是从头脂质合成的关键酶。对一组6个受miR-27a调控的蛋白质的表达进行了验证，并进一步验证了一个受miR-27a调控的蛋白质的功能。这些结果不仅阐明了miR-27a调节脂肪代谢和细胞增殖的潜在机制，还揭示了miR-27a在HSCs激活过程中促进肌源性转分化的新作用。本研究还例证了蛋白质组学策略作为miRNA功能研究的有力工具。
