Institute of Biotechnology, HiLIFE, University of Helsinki, Viikinkaari 5D, 00790 Helsinki, Finland.
Institute of Molecular Biology and Genetics, NASU, 03143 Kyiv, Ukraine.
Int J Mol Sci. 2021 Sep 7;22(18):9691. doi: 10.3390/ijms22189691.
Mesencephalic astrocyte derived neurotrophic factor (MANF) and cerebral dopamine neurotrophic factor (CDNF) are novel evolutionary conserved trophic factors, which exhibit cytoprotective activity via negative regulation of unfolded protein response (UPR) and inflammation. Despite multiple reports demonstrating detrimental effect of MANF/CDNF downregulation, little is known about the control of their expression. miRNAs-small non-coding RNAs-are important regulators of gene expression. Their dysregulation was demonstrated in multiple pathological processes and their ability to modulate levels of other neurotrophic factors, glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF), was previously reported. Here, for the first time we demonstrated direct regulation of MANF and CDNF by miRNAs. Using bioinformatic tools, reporter assay and analysis of endogenous MANF and CDNF, we identified that miR-144 controls MANF expression, and miR-134 and miR-141 downregulate CDNF levels. We also demonstrated that this effect is human-specific and is executed via predicted binding sites of corresponding miRNAs. Finally, we found that miR-382 suppressed hCDNF expression indirectly. In conclusion, we demonstrate for the first time direct regulation of MANF and CDNF expression by specific miRNAs, despite the fact their binding sites are not strongly evolutionary conserved. Furthermore, we demonstrate a functional effect of miR-144 mediated regulation of MANF on ER stress response markers. These findings emphasize that (1) prediction of miRNA targets based on evolutionary conservation may miss biologically meaningful regulatory pairs; and (2) interpretation of miRNA regulatory effects in animal models should be cautiously validated.
中脑星形胶质细胞衍生神经营养因子 (MANF) 和脑源性神经营养因子 (CDNF) 是新型进化保守的营养因子，通过负向调节未折叠蛋白反应 (UPR) 和炎症发挥细胞保护作用。尽管有多项研究报告表明 MANF/CDNF 下调具有有害作用，但人们对其表达的控制知之甚少。miRNAs-小的非编码 RNA-是基因表达的重要调控因子。它们在多种病理过程中的失调已被证明，并且它们调节其他神经营养因子（胶质细胞源性神经营养因子 (GDNF) 和脑源性神经营养因子 (BDNF)）水平的能力以前也有报道。在这里，我们首次证明了 miRNAs 对 MANF 和 CDNF 的直接调控。使用生物信息学工具、报告基因检测和内源性 MANF 和 CDNF 的分析，我们确定了 miR-144 控制 MANF 的表达，而 miR-134 和 miR-141 下调 CDNF 的水平。我们还证明，这种效应是人类特有的，是通过相应 miRNAs 的预测结合位点执行的。最后，我们发现 miR-382 间接抑制 hCDNF 的表达。总之，我们首次证明了特定 miRNAs 对 MANF 和 CDNF 表达的直接调控，尽管它们的结合位点没有得到强烈的进化保守。此外，我们还证明了 miR-144 介导的 MANF 调控对 ER 应激反应标志物的功能影响。这些发现强调了 (1) 基于进化保守性预测 miRNA 靶标可能会错过具有生物学意义的调节对；(2) 在动物模型中解释 miRNA 调节作用时应谨慎验证。
