Using a new technique which takes adult cells back to their embryonic form, U.S. researchers at the Salk Institute in California showed it was possible to reverse aging in mice, allowing the animals to not only look younger, but live for 30 percent longer.

    The technique involves stimu-lating four genes which are particularly active during development in the womb. It was also found to work to turn the clock back on human skin cells in the lab, making them look and behave younger.

    Scientists hope to eventually create a drug which can mimic the effect of the found genes which could be taken to slow down and even reverse the aging process. They say it will take around 10 years to get to human trials.

    “Our study shows that aging may not have to proceed in one single direction,” said Dr. Juan Carlos Izpisua Belmonte, a professor in Salk’s Gene Expression Laboratory. “With careful modulation, aging might be reversed.”

    “Obviously, mice are not humans and we know it will be much more complex to rejuvenate a person. But this study shows that aging is a very dynamic and plastic process, and therefore will be more amenable to therapeutic interventions than what we previously thought.”

    Scientists have known for some time that the four genes, which are known collectively as the Yamanaka factors, could turn adult cells back to their stem cell state, where they can grow into any part of the body.

    But it was always feared that allowing that to happen could damage organs made from the cells, and even trigger cancer.

    However, it was discovered that stimulating the genes intermittently reversed aging, without causing any damaging side effects.

    “In other studies scientists have completely reprogramed cells all the way back to a stem-cell-like state,” says co-first author Pradeep Reddy, also a Salk research associate.

    “But we show, for the first time, that by expressing these factors for a short duration you can maintain the cell’s identity while reversing age-associated hallmarks.”

美国加利福尼亚索尔克研究所的研究员利用一项新技术让成年鼠细胞重回胚胎状态，证明在老鼠身上可以实现逆生长，不仅能让老鼠看上去更年轻，还能延长其寿命30%。

该技术会刺激在子宫内发育阶段特别活跃的四种基因。实验发现该技术可以让人类的皮肤细胞逆龄生长，让皮肤细胞的状态更年轻。

科学家们希望最终可以发明与这四种基因具有相同效用的药，减缓细胞衰老，甚至逆转衰老的过程。他们表示，进入人体试验阶段大概需要10年时间。

“我们的研究表明，衰老不一定是一个单向的过程，”索尔克基因表现试验室的专家胡安•卡洛斯•贝尔蒙特博士说，“通过小心谨慎的调节，衰老的过程可能逆转。”

“显然，老鼠与人类不同，我们知道让一个人重返年轻要复杂得多。但是该研究表明衰老是一个动态的和可塑性极强的过程，因此要比我们之前认为的更加经受得住医疗的干预。”

科学家们对这四种基因的了解已有多时，它们被集体称为山中因子，可以让成人细胞重新回到干细胞的状态，在这种状态下，细胞可以分化形成人体的任何器官。

但一直令人担心的是，这样做可能会损害由这些细胞组成的器官，甚至引发癌症。

然而研究发现，间歇性地刺激这四种基因，逆转衰老过程，并不会引起任何破坏性的副作用。

“在其他研究中，科学家们已经对细胞进行了完全重组，让成人细胞重回类似干细胞的状态。”共同第一作者兼索尔克助理研究员普拉迪普•雷迪说。

“但我们首次发现，通过短时间地重组这些因素，你可以既保持细胞的身份，也能逆转与衰老相关的印记。”

(Chinadaily.com.cn)

Words to Learn 相关词汇

【逆转】nìzhuǎn reverse turn in an opposite position

【可塑的】kěsù de plastic capable of being molded