Gruber Heike, Wessels Wiebke, Boynton Primrose, Xu Jinze, Wohlgemuth Stephanie, Leeuwenburgh Christiaan, Qi Wenbo, Austad Steven N, Schaible Ralf, Philipp Eva E R
Max-Planck-Institute for Evolutionary Biology, August-Thienemann Str. 2, 24306, Plön, Germany,
Age (Dordr). 2015 Oct;37(5):90. doi: 10.1007/s11357-015-9831-8. Epub 2015 Aug 29.
One of the biggest challenges to studying causes and effects of aging is identifying changes in cells that are related to senescence instead of simply the passing of chronological time. We investigated two populations of the longest living non-colonial metazoan, Arctica islandica, with lifespans that differed sixfolds. Of four investigated parameters (nucleic acid oxidation, protein oxidation, lipid oxidation, and protein instability), only nucleic acid oxidation increased with age and correlated with relative lifespan. Nucleic acid oxidation levels increased significantly faster and were significantly higher in the shorter-lived than the longer-lived population. In contrast, neither protein oxidation, lipid oxidation, nor protein stability changed over time. Protein resistance to unfolding stress when treated with urea was significantly lower overall in the shorter-lived population, and lipid peroxidation levels were higher in the longer-lived population. With the exception of nucleic acid oxidation, damage levels of A. islandica do not change with age, indicating excellent cellular maintenance in both populations. Since correlations between nucleic acid oxidation and age have also been shown previously in other organisms, and nucleic acid oxidation accumulation rate correlates with relative age in both investigated populations, nucleic acid oxidation may reflect intrinsic aging mechanisms.
研究衰老的原因和影响面临的最大挑战之一是识别细胞中与衰老相关的变化，而不仅仅是时间的流逝。我们研究了最长寿的非群居后生动物北极蛤的两个群体，它们的寿命相差六倍。在四个研究参数（核酸氧化、蛋白质氧化、脂质氧化和蛋白质不稳定性）中，只有核酸氧化随年龄增长而增加，并且与相对寿命相关。核酸氧化水平在寿命较短的群体中增加得明显更快，且显著高于寿命较长的群体。相比之下，蛋白质氧化、脂质氧化和蛋白质稳定性均未随时间变化。在寿命较短的群体中，用尿素处理时蛋白质对解折叠应激的抵抗力总体上显著较低，而在寿命较长的群体中脂质过氧化水平较高。除了核酸氧化外，北极蛤的损伤水平不会随年龄变化，这表明两个群体的细胞维持能力都很强。由于之前在其他生物中也发现了核酸氧化与年龄之间的相关性，并且在两个研究群体中核酸氧化积累速率都与相对年龄相关，因此核酸氧化可能反映了内在的衰老机制。
