2015年4月13日訊 /生物谷BIOON/ --近日,國際學術期刊nature communication在線發表了美國科學家的一項最新研究進展,他們利用腺病毒系統在小鼠肝臟細胞內製造DNA雙鏈斷裂(DSB),在體內證明了DNA損傷會導致肝臟組織衰老,彌補了DNA損傷與組織器官衰老之間的體內證據,對於DNA損傷與衰老研究具有一定意義。
DNA雙鏈斷裂是DNA損傷眾多類型中的一種,在幾乎所有生物中都會發生,這一過程可以受到多種條件的誘導,並且雙鏈斷裂會導致基因組重排,因此DSB過程在促進腫瘤發生以及衰老方面具有重要作用。
DNA損傷可參與衰老過程,但目前仍缺少直接證據證明兩者因果關係,其主要原因是由於在細胞和組織內誘導特定的DNA損傷,同時不損傷其他生物分子和細胞結構存在困難。在該研究中,研究人員利用腺病毒系統在細胞內表達四環素調節的SacI 限制性內切酶,進而檢測高毒性的DNA雙鏈損傷是否會驅動衰老表型的出現。研究人員將腺病毒注入小鼠體內,然後將肝臟內的分子與細胞與正常衰老的小鼠進行了對比。對3月齡的小鼠進行了病毒處理後,發現其表現出許多特徵,包括衰老的病理特徵,出現細胞衰老的標記,線粒體發生融合,並且基因表達譜也出現改變。
綜上所述,這些結果表明DNA雙鏈斷裂會在小鼠肝臟造成衰老表型,為研究DNA損傷在驅動組織衰老方面的作用提供了新的見解。(生物谷Bioon.com)
Controlled induction of DNA double-strand breaks in the mouse liver induces features of tissue ageing
Ryan R. White,Brandon Milholland,Alain de Bruin,Samuel Curran,Remi-Martin Laberge,Harry van Steeg,Judith Campisi,Alexander Y. Maslov & Jan Vijg
DNA damage has been implicated in ageing, but direct evidence for a causal relationship is lacking, owing to the difficulty of inducing defined DNA lesions in cells and tissues without simultaneously damaging other biomolecules and cellular structures. Here we directly test whether highly toxic DNA double-strand breaks (DSBs) alone can drive an ageing phenotype using an adenovirus-based system based on tetracycline-controlled expression of the SacI restriction enzyme. We deliver the adenovirus to mice and compare molecular and cellular end points in the liver with normally aged animals. Treated, 3-month-old mice display many, but not all signs of normal liver ageing as early as 1 month after treatment, including ageing pathologies, markers of senescence, fused mitochondria and alterations in gene expression profiles. These results, showing that DSBs alone can cause distinct ageing phenotypes in mouse liver, provide new insights in the role of DNA damage as a driver of tissue ageing.