科学家成功使人体细胞“返老还童”

Eternal youth could be one step closer following the successful transformation of old human cells into young ones.
随着科学家成功地将人体衰老细胞转换成年轻的细胞，人类距离青春永驻的梦想将更近一步。

The process increases the length of the 'telomeres', which are the protective caps on the end of chromosomes that impact ageing and disease.
端粒体是位于染色体末端的“保护帽”，有助于减缓人体衰老，降低疾病发生率。而将衰老细胞转化为年轻细胞的过程能延长端粒体的长度。

Researchers in the US say the technique could extend human life and provide new hope for battling diseases that arise from old age.
美国研究人员称，此项技术将会延长人类寿命，为治疗各种老年疾病带来新的希望。

Telomeres - often described as being like the plastic caps on the end of shoelaces – help keep DNA healthy.
端粒体常被描述为“鞋带末端的塑料帽”，能使脱氧核糖核酸（DNA）保持健康状态。

These protective end caps become shorter with each DNA replication, and eventually are no longer able to protect DNA from sustaining damage and mutations, causing people to age.
随着每次DNA的复制，这些起保护作用的“末端冒”会变得越来越短，最终将丧失对DNA的保护能力。失去保护层的DNA将会受损并发生突变，人类因此会走向衰老。

In young people, telomeres are about 8,000-10,000 organic molecules, or nucleotides, long.
在年轻人体内，端粒体的长度约有8000至1万个有机分子或核苷酸连起来那么长。

'Now we have found a way to lengthen human telomeres by as much as 1,000 nucleotides, turning back the internal clock in these cells by the equivalent of many years of human life,' said Helen Blau of Stanford University.
美国斯坦福大学（Stanford University）的海伦•布劳（Helen Blau）表示：“现在，我们已经发现一种方法，能将人体的端粒体长度延长多达1000个核苷酸的长度。人们体内这些细胞的时钟能被逆转多少，人的寿命就能延长多少年。”

To make the discovery, researchers used modified messenger RNA to extend the telomeres.
为了获得这项发现，研究人员用改良后的信使核糖核酸（RNA）来延长端粒体长度。

RNA carries instructions from genes in the DNA to the cell's protein-making factories.
RNA携带来自DNA基因的指令至细胞的“蛋白质制造工厂”。

The RNA used in this experiment contained the coding sequence for TERT - the active component of a naturally occurring enzyme called telomerase.
实验中使用的RNA含有端粒酶逆转录酶（TERT）的编码序列——自然形成的酶的活性成分叫做端粒酶。

When the cells are treated, they behave as if they are younger and multiply quickly rather than dying.
细胞受到治疗后，会表现得仿佛更加年轻，分裂速度更快而非老化。

'One day it may be possible to target muscle stem cells in a patient with Duchenne muscular dystrophy, for example, to extend their telomeres,' said Dr Blau.
布劳博士表示：“有朝一日，将可能针对杜氏肌肉营养不良症患者的肌肉干细胞，比如通过延长其端粒体进行治疗。”

'There are also implications for treating conditions of aging, such as diabetes and heart disease.
“这种疗法对治疗糖尿病和心脏病等因衰老引发的疾病，也会产生影响。”

'This has really opened the doors to consider all types of potential uses of this therapy.'
“这真的为我们开启了一扇新的大门，让我们思考如何发挥这种疗法的各种潜在用途。”

The researchers also hope that the method will be able to allow scientists to generate large numbers of cells that could someday lead to an effective anti-aging drug.
研究人员也希望，这种方法能让科学家培育出大量细胞，有朝一日可用它们研发出有效的抗衰老药物。

Vocabulary

telomere: 染色体端粒
chromosome: 染色体
replication: 复制
mutation: 突变
nucleotides: 核苷酸
telomerase: 端粒酶
enzyme: 酶
Duchenne muscular dystrophy: 杜氏肌肉营养不良症