Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter, Exeter EX1 2LU, UK.
Mech Ageing Dev. 2013 Sep;134(9):356-66. doi: 10.1016/j.mad.2013.05.006. Epub 2013 Jun 6.
Human ageing is associated with decreased cellular plasticity and adaptability. Changes in alternative splicing with advancing age have been reported in man, which may arise from age-related alterations in splicing factor expression. We determined whether the mRNA expression of key splicing factors differed with age, by microarray analysis in blood from two human populations and by qRT-PCR in senescent primary fibroblasts and endothelial cells. Potential regulators of splicing factor expression were investigated by siRNA analysis. Approximately one third of splicing factors demonstrated age-related transcript expression changes in two human populations. Ataxia Telangiectasia Mutated (ATM) transcript expression correlated with splicing factor expression in human microarray data. Senescent primary fibroblasts and endothelial cells also demonstrated alterations in splicing factor expression, and changes in alternative splicing. Targeted knockdown of the ATM gene in primary fibroblasts resulted in up-regulation of some age-responsive splicing factor transcripts. We conclude that isoform ratios and splicing factor expression alters with age in vivo and in vitro, and that ATM may have an inhibitory role on the expression of some splicing factors. These findings suggest for the first time that ATM, a core element in the DNA damage response, is a key regulator of the splicing machinery in man.
人类衰老与细胞可塑性和适应性降低有关。据报道，随着年龄的增长，人类的剪接方式发生了变化，这可能是由于剪接因子表达的年龄相关性改变所致。我们通过对两个人群的血液进行微阵列分析和对衰老的原代成纤维细胞和内皮细胞进行 qRT-PCR 分析，确定关键剪接因子的 mRNA 表达是否随年龄而变化。通过 siRNA 分析研究了潜在的剪接因子表达调节剂。在两个人群中，大约三分之一的剪接因子表现出与年龄相关的转录表达变化。共济失调毛细血管扩张突变基因 (ATM) 的转录表达与人类微阵列数据中的剪接因子表达相关。衰老的原代成纤维细胞和内皮细胞也表现出剪接因子表达和选择性剪接的改变。在原代成纤维细胞中靶向敲低 ATM 基因导致一些年龄反应性剪接因子转录本的上调。我们的结论是，体内和体外的同工型比率和剪接因子表达随年龄而改变，并且 ATM 可能对一些剪接因子的表达具有抑制作用。这些发现首次表明，ATM 是 DNA 损伤反应的核心要素，是人类剪接机制的关键调节剂。
