Institute for Molecular Medicine, University Hospital Düsseldorf, Moorenstr. 5, Düsseldorf, Germany.
Molecular Neurobiology Laboratory, Department of Neurology, University Hospital Düsseldorf, Moorenstr. 5, 40225, Düsseldorf, Germany.
Sci Rep. 2020 Feb 24;10(1):3284. doi: 10.1038/s41598-020-60065-8.
The contribution of microRNA-mediated posttranscriptional regulation on the final proteome in differentiating cells remains elusive. Here, we evaluated the impact of microRNAs (miRNAs) on the proteome of human umbilical cord blood-derived unrestricted somatic stem cells (USSC) during retinoic acid (RA) differentiation by a systemic approach using next generation sequencing analysing mRNA and miRNA expression and quantitative mass spectrometry-based proteome analyses. Interestingly, regulation of mRNAs and their dedicated proteins highly correlated during RA-incubation. Additionally, RA-induced USSC demonstrated a clear separation from native USSC thereby shifting from a proliferating to a metabolic phenotype. Bioinformatic integration of up- and downregulated miRNAs and proteins initially implied a strong impact of the miRNome on the XXL-USSC proteome. However, quantitative proteome analysis of the miRNA contribution on the final proteome after ectopic overexpression of downregulated miR-27a-5p and miR-221-5p or inhibition of upregulated miR-34a-5p, respectively, followed by RA-induction revealed only minor proportions of differentially abundant proteins. In addition, only small overlaps of these regulated proteins with inversely abundant proteins in non-transfected RA-treated USSC were observed. Hence, mRNA transcription rather than miRNA-mediated regulation is the driving force for protein regulation upon RA-incubation, strongly suggesting that miRNAs are fine-tuning regulators rather than active primary switches during RA-induction of USSC.
在分化细胞中，微小 RNA（miRNA）介导的转录后调控对最终蛋白质组的贡献仍然难以捉摸。在这里，我们通过使用下一代测序分析 mRNA 和 miRNA 表达以及基于定量质谱的蛋白质组分析的系统方法，评估了 miRNA 对人类脐带血来源的无限制体干细胞（USSC）在维甲酸（RA）分化过程中的蛋白质组的影响。有趣的是，在 RA 孵育过程中，mRNA 及其专用蛋白的调节高度相关。此外，RA 诱导的 USSC 与天然 USSC 明显分离，从而从增殖表型转变为代谢表型。上调和下调的 miRNA 和蛋白质的生物信息学整合最初暗示了 miRNA 对 XXL-USSC 蛋白质组的强烈影响。然而，在异位过表达下调的 miR-27a-5p 和 miR-221-5p 或抑制上调的 miR-34a-5p 后，对最终蛋白质组中 miRNA 贡献的定量蛋白质组分析分别显示出差异丰度蛋白的比例较小。此外，在非转染的 RA 处理的 USSC 中，这些受调控的蛋白质与反向丰度的蛋白质之间仅观察到很小的重叠。因此，RNA 转录而不是 miRNA 介导的调节是 RA 孵育时蛋白质调节的驱动力，这强烈表明 miRNA 是精细调节调节剂，而不是 USSC 中 RA 诱导的主动主要开关。
