科學家成功使人體細胞“返老還童”
Eternal youth could be one step closer following the successful transformation of old human cells into young ones.
隨着科學家成功地將人體衰老細胞轉換成年輕的細胞，人類距離青春永駐的夢想將更近一步。
The process increases the length of the 'telomeres', which are the protective caps on the end of chromosomes that impact ageing and disease.
端粒體是位於染色體末端的“保護帽”，有助於減緩人體衰老，降低疾病發生率。而將衰老細胞轉化爲年輕細胞的過程能延長端粒體的長度。
Researchers in the US say the technique could extend human life and provide new hope for battling diseases that arise from old age.
美國研究人員稱，此項技術將會延長人類壽命，爲治療各種老年疾病帶來新的希望。
Telomeres - often described as being like the plastic caps on the end of shoelaces – help keep DNA healthy.
端粒體常被描述爲“鞋帶末端的塑料帽”，能使脫氧核糖核酸（DNA）保持健康狀態。
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.
隨着每次DNA的複製，這些起保護作用的“末端冒”會變得越來越短，最終將喪失對DNA的保護能力。失去保護層的DNA將會受損併發生突變，人類因此會走向衰老。
In young people, telomeres are about 8,000-10,000 organic molecules, or nucleotides, long.
在年輕人體內，端粒體的長度約有8000至1萬個有機分子或核苷酸連起來那麼長。
'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.
美國斯坦福大學（Stanford University）的海倫•布勞（Helen Blau）表示：“現在，我們已經發現一種方法，能將人體的端粒體長度延長多達1000個核苷酸的長度。人們體內這些細胞的時鐘能被逆轉多少，人的壽命就能延長多少年。”
To make the discovery, researchers used modified messenger RNA to extend the telomeres.
爲了獲得這項發現，研究人員用改良後的信使核糖核酸（RNA）來延長端粒體長度。
RNA carries instructions from genes in the DNA to the cell's protein-making factories.
RNA攜帶來自DNA基因的指令至細胞的“蛋白質製造工廠”。
The RNA used in this experiment contained the coding sequence for TERT - the active component of a naturally occurring enzyme called telomerase.
實驗中使用的RNA含有端粒酶逆轉錄酶（TERT）的編碼序列——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.
細胞受到治療後，會表現得彷彿更加年輕，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.
布勞博士表示：“有朝一日，將可能針對杜氏肌肉營養不良症患者的肌肉乾細胞，比如通過延長其端粒體進行治療。”
'There are also implications for treating conditions of aging, such as diabetes and heart disease.
“這種療法對治療糖尿病和心臟病等因衰老引發的疾病，也會產生影響。”
'This has really opened the doors to consider all types of potential uses of this therapy.'
“這真的爲我們開啓了一扇新的大門，讓我們思考如何發揮這種療法的各種潛在用途。”
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.
研究人員也希望，這種方法能讓科學家培育出大量細胞，有朝一日可用它們研發出有效的抗衰老藥物。
Vocabulary
telomere: 染色體端粒
chromosome: 染色體
replication: 複製
mutation: 突變
nucleotides: 核苷酸
telomerase: 端粒酶
enzyme: 酶
Duchenne muscular dystrophy: 杜氏肌肉營養不良症
