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人体老化可以逆转 返老还童或许不是梦

更新时间:2019/10/21 12:44:49 来源:纽约时报中文网 作者:佚名

The ambitious quest to cure ageing like a disease
人体老化可以逆转 返老还童或许不是梦

The list of diseases humankind has managed to defeat is impressive – polio, typhoid, measles, tetanus, yellow fever, smallpox, diphtheria and chicken pox have been almost completely eliminated in many parts of the world. Vaccines and powerful drugs have allowed our species to fight back against the bacteria, parasites and viruses that threaten to kill us.

人类已经成功战胜的疾病清单非常惊人——在全世界的很多地方,小儿麻痹症、伤寒、麻疹、破伤风、黄热病、天花、白喉和水痘已经几乎销声匿迹。疫苗和强效药帮助人类抵抗威胁生命的细菌、寄生虫和病毒。

But throughout history, humans have suffered from a condition that they have never been able to escape – ageing. As we get older, our cells stop working as well and can break down, leading to conditions like cancer, heart disease, arthritis and Alzheimer’s disease. Together, ageing-related diseases are responsible for 100,000 deaths per day and billions are spent around the world trying to slow their steady march on our bodies.

但是有史以来人类从来都无法逃避一个病症——衰老。随着人渐渐变老,细胞的工作能力下降,有可能会停止工作,导致癌症、心脏病、关节炎和阿兹海默症(老年痴呆症)等。全球每天有10万人因为与衰老相关的疾病而死亡。全世界各地人们每年花费数十亿来试图减缓衰老进程。

Some researchers, however, believe we may be thinking about these conditions in the wrong way. They say we should start treating ageing itself as a disease – one that can be prevented and treated. In a recent episode of the BBC Tomorrow’s World podcast, my fellow presenter Ellie Cosgrave and I spoke to some of those who are investigating ways to slow and even halt the ageing process.

不过,有研究人员认为我们对衰老的看法可能是错误的。他们表示,我们应开始把衰老本身视为一种疾病——它是可以被阻止和治疗的。在BBC Tomorrow的最新一集World播客中,埃莉·科斯格雷夫(Ellie Cosgrave)和我一起与一些正在探究延缓、甚至阻止衰老过程方法的研究人员对话。

Their hopes are founded on recent discoveries that suggest biological ageing may be entirely preventable and treatable. From a biological perspective, the body ages at different rates according to genetic and environmental factors. Tiny errors build up in our DNA and our cells begin developing faults that can accumulate into tissue damage. The extent of these changes over time can mean the difference between a healthy old age or one spent housebound and afflicted by chronic diseases.

他们的希望是建立在最近的一些研究发现基础之上。研究者认为生物学上的衰老有可能是完全可避免和可治疗的。从生物学的视角来看,身体根据基因和环境因素按照不同的速度衰老。我们的基因中的微小错误会逐渐累积,于是细胞开始出现错误,进而累积成组织损坏。这些变化的程度在一段时间之后可能意味有的人可能健康度过晚年,而有的人会受到慢性病的困扰,必须长期在家中休养。

The scientists who hope to do this sit on the fringes of the mainstream medical landscape. But there are now a number of research centres around the world that have made identifying ways of preventing biological ageing a priority. Studies in animals have shown that it is indeed possible to dramatically extend the lifespan of certain species, giving hope that it could also be possible in humans.

希望在该领域有所成就的科学家仍属于主流医学界的边缘人群。但是现在全世界已经有一些研究中心把探索预防生物学衰老的方法放到优先位置。动物研究表明某些物种大幅延长寿命确实是可能的,所以人类也有望实现这一点。

One common diabetes drug, metformin, was able to extend the lifespan of rodents. In the early 1990s, Cynthia Kenyon, now vice president of ageing research at Calico Labs, the Google-backed anti-ageing research company, demonstrated that roundworms could live six weeks instead of their natural three just by changing a single letter of their genetic code.

一种平常的糖尿病药物二甲双胍能够延长啮齿类动物的寿命。20世纪90年代初,谷歌支持的抗衰老研究公司Calico Labs的副总裁辛西娅·凯尼恩(Cynthia Kenyon)曾演示过,只需通过修改蛔虫基因密码中的一个字母,它的寿命就可以从自然的三周延长到六周。

In our Tomorrow’s World podcast episode about ageing, one of the leading figures in human longevity research, Aubrey De Grey, tells us how similar increases in lifespan could be achieved in humans. De Grey is the chief science officer at the Strategies for Engineered Negligible Senescence (Sens) Research Foundation, a California-based regenerative medicine research foundation focused on extending the healthy human lifespan. He explains their goal is to develop a suite of therapies for middle-aged and older people that will leave them physically and mentally equivalent to someone under the age of 30. “Of course, without wiping their memories,” he adds.

在Tomorrow's World播客关于衰老的一集中,人类寿命研究领域的领袖人物奥布里·德·格雷(Aubrey De Grey)告诉我们人类也可以通过类似的方法延长寿命。他是美国可忽略衰老研究工程战略基金会(Strategies for Engineered Negligible Senescence (Sens) Research Foundation)的首席科技官。这是加州的一家再生医药研究基金会,专注于延长人类的健康寿命。他解释说,他们的目标是为中年人和老年人开发一套疗法,让他们重新成为在生理和心理上不到30岁的人。"当然,我们不会消除他们的记忆,"他补充说。

De Grey says they want “to fix the things we don’t like about the changes that happen between the age of 30 and the age of 70”. There are seven biological factors De Grey argues are predominantly responsible for cellular damage that accompanies ageing and underlies ageing-related diseases.

德·格雷说,他们希望"解决三十岁到七十岁之间发生的人们不喜欢的那些改变"。他提出有七个生物学要素构成细胞受损的主要原因,而细胞受损伴随着衰老及与衰老相关疾病。

These include when cells in a tissue are not renewed quickly enough; when cells replicate uncontrollably as occurs in cancer; when cells don’t die when they should, which is another problem in cancer; damage to the DNA of the tiny power plants found in cells, known as mitochondria; the accumulation of waste products inside the cell; waste products that build up outside cells; and the stiffening of the lattice structure outside of cells, called the extra-cellular matrix, which allows tissues to stretch and bend.

这些要素包括组织中的细胞修复速度不足;细胞复制像癌症一样不受控制;细胞的死亡时间过晚,这也是癌症中的一个问题;细胞内小型发电厂线粒体遭到破坏;细胞内垃圾的累积;细胞外垃圾的累积;细胞外晶格结构变僵硬。这种结构被称为细胞外基质,它能够让细胞伸展和弯曲。

De Grey and his team at the Sens Research Foundation say they have identified ways for each of these problems to be combatted with therapies they’re developing.

德·格雷和他在美国可忽略衰老研究工程战略基金会的团队说,他们已经找到了方法逐一应对这些问题,并且正在开发相应的疗法。

“The fix for the first (problem) of having too few cells is stem cell therapy,” says De Grey. This provides tissue with a fresh supply of young cells to replace those that die during ageing. Other issues, such as when cells don’t die when they are supposed to, may require more complex solutions.

"第一个问题细胞太少的解决办法是干细胞疗法,"德·格雷说。可以为组织提供新一批年轻细胞,替代那些在衰老过程中死去的细胞。其他问题,比如细胞死亡过晚,可能需要较为复杂的解决方案。

“In principle, we could use gene targeting to introduce suicide genes – genes which the cells will express that will make proteins that will simply kill the cell,” says De Grey. The trick here, however, will be engineering the genes in such a way that they will only express the lethal protein if the cell’s growth patterns are doing more bad than good.

"原则上,我们可以利用基因靶向引入自杀式基因——这种基因的表达方式是产生会杀死细胞自身的蛋白质,"德·格雷说。难点在于基因设计必须做到当基因的增长方式弊大于利时才会产生致命蛋白质。

De Grey doesn’t think that it will be possible stop ageing altogether with these types of approaches, but they may give patients an extra 30 years or so of life. He envisages a future where “rejuvenation technologies” can be administered to old people in order to revert their cells to what they were like when they were in their youth, buying them extra time. The idea is that someone who is treated at the age of 60 will be biologically reverted to 30. But because the therapies are not permanent fixes, their cells will end up becoming 60 years old again in another 30 years time.

德·格雷认为,即使使用这些方法,也不可能完全阻止衰老,但是这会让患者多活30年左右。他设想的未来是,老年人可以通过接受"恢复青春科技"疗法,把细胞逆转为年轻时的状态,延长细胞的寿命。这个理念就是当患者在60岁接受治疗时,他在生物学上能够回到30岁的状态。但是,因为这些疗法并不是一劳永逸的,所以再过30年,这些细胞还是会变成60岁的状态。

By then De Grey hopes the therapies could be reapplied as “version 2.0” to revert the same individuals once again to become younger in their cells. As a result, that person’s cells wouldn’t become 60 again until they’re about 150 years old.

但是到那个时候,德·格雷希望可以施用第二代技术,让同一批人再度回到年轻状态。所以,他们的细胞要到150岁时才会变成60岁的状态。

But, there needs to be some caution when dealing with claims like this. There is no experimental evidence to show that our bodies would respond to this sort of “software update”. Much like computers, with too many updates our bodies could grind to a halt.

但是我们需要谨慎对待这样的说法,因为没有实验证据表明我们的身体会对这种"软件升级"作出反应。就像电脑一样,如果升级太多,我们的身体可能就会陷入宕机状态。

But De Grey believes this kind of thinking, something he calls “the pro-ageing trance”, is holding back the advance of anti-ageing technologies. The problem, he says, is that we culturally accept ageing as unavoidable and so attempts to halt the damage it causes are often dismissed as quack science.

但是德·格雷深信这种看法,一种被他称为"在恍惚中默认衰老"的观念正在阻碍抗衰老科技的进步。他说,问题在于我们在文化上接受衰老是一个不可避免的问题,所以阻止细胞损坏的尝试常常被斥为伪科学。

And he is not alone in believing ageing-related diseases can be solved. George Church, a geneticist at Harvard Medical School, told us that while some of his colleagues argue many age-related diseases are so complex that they simply can’t be treated, he finds such thinking to be incorrect.

不止他一人相信与衰老有关的疾病是可以治愈的。哈佛医学院的基因学家乔治·丘奇(George Church)告诉我们,虽然他的同事辩称很多与衰老有关的疾病非常复杂,以至于无法治愈,但是他觉得这种想法是错误的。

“If you can control both the environment and the genetics, you can get people that live youthful healthy lives for exceptionally much longer than others,” says Church. “In industrialised nations, most of the diseases are due to age-related diseases and I think those too can be handled.”

"如果你能够同时控制环境和基因,那么你就可以让人活得年轻又健康,而且寿命比其他人长很多,"丘奇说,"在工业化国家,大多数疾病都与衰老有关,我觉得这些疾病是可以应对的。"

Among the prominent approaches to increasing longevity is a gruesome-sounding procedure that is commonly known as “vampire therapy”. Dementia patients who were given transfusions of blood plasma from younger donors aged between 18 and 30 years old showed signs of improvement in a recent trial. Patient’s with early-onset Alzheimer’s disease regained the ability to bathe or dress themselves, or to do other tasks such as housework.

在延长寿命的著名方法中有一种听起来毛骨悚然的疗法,通常被称为"吸血鬼疗法"。在最近的一次试验中,老年痴呆症患者在获得18至30岁年轻人的献血后,病情有所好转。这些早发型老年痴呆症患者从此恢复了穿衣或洗澡的自理能力,有的还能够完成家务等其他事项。

While this trial is still ongoing, one US start-up called Ambrosia is already offering older customers the chance to receive transfusions of blood from donors aged between 16 and 25 years old for $8,000 (£5,985) per treatment. The company says that these transfusions can boost the performance of older people’s lethargic cells, and also claims to have improved the condition of an early-onset Alzheimer’s patient as well as have turned the hair of a 60-something-year-old patient darker. Their research, however, has yet to be published in any peer-reviewed journals and has been criticised for not accounting for the placebo effect.

虽然这个试验仍在进行中,美国一家名为Ambrosia的创业公司已经开始为老客户提供获得16至25岁年轻人献血的机会,一次治疗费用为8000美元。该公司称,这种输血能够增强老年人懒惰细胞的表现。另外,公司还声称它改善了早发型老年痴呆症患者的病情,还有让一位60多岁的患者头发变黑。不过,他们的研究尚未发表到任何同行评议的期刊上,还被批评没有纳入计算安慰剂的作用。

But there are some studies in animals that suggest there may be a biological basis for the effects these treatments are having. In 2013, a study by researchers at the Harvard Stem Cell Institute showed the muscle strength of mice could be improved by a growth factor found in young blood called GDF11, though the findings could not be replicated. BBC Future has previously explored some of the other approaches in animals that could lead to a longer life. Meanwhile, others say the key to longevity is as simple as cutting the amount of calories you consume in a day.

但是有动物研究表明这些疗法产生的效果可能存在生物学基础。2013年哈佛干细胞研究所的一项研究表明年轻血液中名为GDF11的生长因素有可能增强老鼠的肌肉力量,尽管这些研究结果无法重现。BBC Future此前报道过延长动物寿命的其他方法。同时,还有人认为长寿的关键非常简单,就是削减每天卡路里的摄入量。

But what about actually “curing” death? There have long been proposals to do this by cryogenically freezing a person’s brain or body immediately after death so they can be revived at a later date when technology has advanced sufficiently. A number of companies even offer the opportunity for wealthy clients to preserve their bodies in this way, such the Alcor Life Extension Foundation. However, to date, none of their clients have ever been resurrected from their icy storage units.

但是什么能真正"治愈"死亡?很早以前就有人提出在人刚刚死亡时冷冻大脑或者身体,这样就可以等待日后技术足够进步以后再重生。一些公司甚至为富有的客户提供冷冻保存身体的机会,比如阿尔科生命延续基金(Alcor Life Extension Foundation)。然而,到目前为止,还没有任何客户从冷冻储藏单元中被复活。

Others, such as Ray Kurzweil, theorist of the Singularity and lead engineer at Google have espoused “mind uploading” as a way to achieve (at least digital) immortality.

再比如奇点理论家、谷歌首席工程师雷·科兹威尔(Ray Kurzweil)赞成通过"上传大脑"的方法实现永生(至少在数字化的意义上)。

It’s easy to conflate these outlandish ideas, which seem more based in science fiction than reality, with the lab-based work De Grey and others in longevity research are doing. But regardless of how it is achieved, extending human lifespans by decades or even hundreds of years will present us with some difficult social realities. As BBC Future has explored before, there could be major societal impacts if we all start living longer. There are some that fear greater longevity could lead to swelling populations and raise doubts that our planet could support such numbers.

这些怪异的想法很容易与德·格雷等人的长寿实验混同起来,看似更像是科幻小说,而非现实。但是,不论它将如何实现,如果人类寿命延长数十年或者甚至数百年,那么社会现实就会出现一些麻烦。BBC Future曾探讨过这个话题,如果人们都开始延长寿命,可能会出现重大社会影响。一些人担心寿命延长可能会导致人口过度增长,让人担忧地球能否支撑庞大的人口规模。

De Grey himself says he is often asked about whether the technologies he is working on could be abused by wealthy tyrants to give them extended lifespans, while others ask whether we will simply be bored by lives that can be continuously extended.

德·格雷说,常有人问他这些技术会不会被富有的独裁者滥用,为他们自己延长寿命,还有人会问如果生命可以不断延续,我们会不会觉得无聊。

He has little time for such questions and believes that other technologies – such as artificial meat, desalination, solar energy and other renewables – will increase the carrying capacity of the planet, allowing more people to live longer lives. But this rationale suffers from a dependence on uncertain techno-fixes that may not alleviate suffering in an equally distributed manner.

他几乎没有时间回答这样的问题。他相信其他技术——比如人造肉、海水淡化、太阳能等其他可更新能源——将增加地球的承载能力,让更多的人能够享受长寿生活。但是这一原理受制于某些不确定的技术困境,它可能无法以平均分配的方式减轻痛苦。

Yet, if concerns like these had paralysed the early pioneers of vaccination and antibiotics, it is unlikely many of us today could expect to live much beyond the age of 40-years-old. Advances in medicine over the last two centuries have taught us that we have the power to defeat the diseases that afflict us. Perhaps if we apply ourselves, then we can beat ageing too.

然而,如果类似这类担忧当年束缚了疫苗和抗生素的研究先驱,那么如今的我们有很多人都不太可能活过40岁。过去两个世纪,医学的进步告诉我们,人类有能力战胜疾病。如果我们去尝试,也有可能战胜衰老。

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