miR-424-5p reduces ribosomal RNA and protein synthesis in muscle wasting.
miR-424-5p reduces ribosomal RNA and protein synthesis in muscle wasting.
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DOI：
10.1002/jcsm.12266
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发表时间：
2018-04
期刊：
影响因子：
--
通讯作者：
Kemp PR
中科院分区：
文献类型：
--
作者：
Connolly M;Paul R;Farre-Garros R;Natanek SA;Bloch S;Lee J;Lorenzo JP;Patel H;Cooper C;Sayer AA;Wort SJ;Griffiths M;Polkey MI;Kemp PR
肌肉质量的损失是一系列慢性和急性疾病以及老年人的结果。这种浪费是由于蛋白质合成和降解的不平衡，合成减少和对合成代谢刺激的抵抗经常报告的特征。核糖体是蛋白质合成所必需的，因此核糖体合成控制的变化是肌肉萎缩的潜在因素。微RNA（miRNAs）是已知的肌肉表型的调节因子，并且已经显示出调节蛋白质合成途径的组分。一种被预测靶向蛋白质合成途径的许多组分的miRNA是miR-424 - 5 p，其在慢性阻塞性肺疾病（COPD）患者的四头肌中升高。通过Argonaute 2 pull down鉴定miR-424 - 5 p的靶点，并通过定量聚合酶链反应和蛋白质印迹法在体外肌细胞中确定miRNA对RNA和蛋白质表达的影响。通过嘌呤霉素体外掺入法测定蛋白质合成。通过电穿孔，miRNA在小鼠胫骨前肌中过表达，并量化其影响。最后，通过定量聚合酶链反应测定了COPD和重症监护病房（ICU）获得性虚弱患者和接受主动脉手术患者以及赫特福德郡肌肉减少症研究个体的四头肌miRNA表达。下拉分析显示，miR-424 - 5 p与编码与肌肉蛋白质合成相关的蛋白质的信使RNA结合。最高度富集的信使RNA编码核糖体RNA（rRNA）转录所需的Pol I RNA前起始复合物（PolR 1A和上游结合转录因子）所需的蛋白质。在体外，miR-424 - 5 p降低了这些RNA的表达，降低了rRNA水平，并抑制了蛋白质合成。在小鼠中，miR-322（啮齿动物miR-424直系同源物）的过度表达导致纤维萎缩，并降低上游结合转录因子表达和rRNA水平。在人类中，miR-424 - 5 p升高与COPD（FEV1%）、接受主动脉手术的患者（LVEF%）和ICU获得性虚弱患者（ICU天数）的疾病严重程度标志物相关。在接受主动脉手术的患者中，骨骼肌中的术前miR-424 - 5 p表达与随后7天的肌肉损失相关。这些数据表明，miR-424 - 5 p通过抑制Pol I前起始复合物的形成来调节rRNA合成。与肌肉萎缩相关的疾病患者中miR-424 - 5 p表达增加可能有助于抑制蛋白质合成和肌肉质量损失。
A loss of muscle mass occurs as a consequence of a range of chronic and acute diseases as well as in older age. This wasting results from an imbalance of protein synthesis and degradation with a reduction in synthesis and resistance to anabolic stimulation often reported features. Ribosomes are required for protein synthesis, so changes in the control of ribosome synthesis are potential contributors to muscle wasting. MicroRNAs (miRNAs) are known regulators of muscle phenotype and have been shown to modulate components of the protein synthetic pathway. One miRNA that is predicted to target a number of components of protein synthetic pathway is miR‐424‐5p, which is elevated in the quadriceps of patients with chronic obstructive pulmonary disease (COPD). Targets of miR‐424‐5p were identified by Argonaute2 pull down, and the effects of the miRNA on RNA and protein expression were determined by quantitative polymerase chain reaction and western blotting in muscle cells in vitro. Protein synthesis was determined by puromycin incorporation in vitro. The miRNA was over‐expressed in the tibialis anterior muscle of mice by electroporation and the effects quantified. Finally, quadriceps expression of the miRNA was determined by quantitative polymerase chain reaction in patients with COPD and intensive care unit (ICU)‐acquired weakness and in patients undergoing aortic surgery as well as in individuals from the Hertfordshire Sarcopenia Study. Pull‐down assays showed that miR‐424‐5p bound to messenger RNAs encoding proteins associated with muscle protein synthesis. The most highly enriched messenger RNAs encoded proteins required for the Pol I RNA pre‐initiation complex required for ribosomal RNA (rRNA) transcription, (PolR1A and upstream binding transcription factor). In vitro, miR‐424‐5p reduced the expression of these RNAs, reduced rRNA levels, and inhibited protein synthesis. In mice, over‐expression of miR‐322 (rodent miR‐424 orthologue) caused fibre atrophy and reduced upstream binding transcription factor expression and rRNA levels. In humans, elevated miR‐424‐5p associated with markers of disease severity in COPD (FEV1%), in patients undergoing aortic surgery (LVEF%), and in patients with ICU‐acquired weakness (days in ICU). In patients undergoing aortic surgery, preoperative miR‐424‐5p expression in skeletal muscle was associated with muscle loss over the following 7 days. These data suggest that miR‐424‐5p regulates rRNA synthesis by inhibiting Pol I pre‐initiation complex formation. Increased miR‐424‐5p expression in patients with conditions associated with muscle wasting is likely to contribute to the inhibition of protein synthesis and loss of muscle mass.
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DOI：
10.1073/pnas.0909873106
发表时间：
2009-10-20
影响因子：
11.1
作者：
Hoppe, Sven;Bierhoff, Holger;Voit, Renate
通讯作者：
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DOI：
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发表时间：
2007-08-01
影响因子：
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影响因子：
6
作者：
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通讯作者：
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DOI：
10.1016/j.biocel.2013.05.039
发表时间：
2013-10
影响因子：
4
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影响因子：
16
作者：
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Lamond AI