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  • Where does the end begin?

    譯者: Lilian Chiu 審譯者: Helen Chang

  • Well, for me, it all began with this little fellow.

    結束是從何開始的?

  • This adorable organism --

    對我來說,它開始於這個小傢伙。

  • well, I think it's adorable --

    這可愛的有機體,

  • is called Tetrahymena and it's a single-celled creature.

    我認為它很可愛,

  • It's also been known as pond scum.

    它叫做四膜蟲,是種單細胞生物。

  • So that's right, my career started with pond scum.

    它也就是池塘浮渣。

  • Now, it was no surprise I became a scientist.

    是的,我的職涯始於池塘浮渣。

  • Growing up far away from here,

    我變成科學家並不讓人意外。

  • as a little girl I was deadly curious

    我在離這裡很遠的地方長大,

  • about everything alive.

    我小時候非常有好奇心,

  • I used to pick up lethally poisonous stinging jellyfish and sing to them.

    對所有的生物都好奇。

  • And so starting my career,

    我以前會撿起有致命劇毒 會螫人的水母,然後對牠們唱歌。

  • I was deadly curious about fundamental mysteries

    所以,開始我的職涯時,

  • of the most basic building blocks of life,

    我非常好奇,想解開最根本的謎題,

  • and I was fortunate to live in a society where that curiosity was valued.

    想知道構成生命的基礎積木是什麼,

  • Now, for me, this little pond scum critter Tetrahymena

    很幸運,我所在的社會 很重視好奇心。

  • was a great way to study the fundamental mystery

    對我而言,四膜蟲 這池塘浮渣小生物

  • I was most curious about:

    是研究我最好奇的 根本謎題的好方式:

  • those bundles of DNA in our cells called chromosomes.

    我們的細胞內大量的 DNA,

  • And it was because I was curious about the very ends of chromosomes,

    也就是所謂的染色體。

  • known as telomeres.

    因為我對染色體的末端很好奇,

  • Now, when I started my quest,

    也就是所謂的端粒。

  • all we knew was that they helped protect the ends of chromosomes.

    當我開始探索,

  • It was important when cells divide.

    我們只知道:它們 協助保護染色體的末端。

  • It was really important,

    細胞分裂時,這點很重要。

  • but I wanted to find out what telomeres consisted of,

    它相當重要,

  • and for that, I needed a lot of them.

    但我想要了解端粒是什麼組成的,

  • And it so happens that cute little Tetrahymena

    為這個目的,我需要很多端粒。

  • has a lot of short linear chromosomes,

    剛好這個可愛的小四膜蟲

  • around 20,000,

    有很多短短線性的染色體。

  • so lots of telomeres.

    大約兩萬個,

  • And I discovered that telomeres consisted of special segments

    所以會有很多端粒。

  • of noncoding DNA right at the very ends of chromosomes.

    我發現端粒包括

  • But here's a problem.

    位在染色體最末端 未編碼的特殊 DNA 區段。

  • Now, we all start life as a single cell.

    但,有一個問題。

  • It multiples to two. Two becomes four. Four becomes eight,

    生命是從單細胞開始的。

  • and on and on to form the 200 million billion cells

    一個會變成兩個, 兩個變成四個,四個變成八個,

  • that make up our adult body.

    一路這樣下去, 形成了二十萬兆個細胞,

  • And some of those cells have to divide thousands of times.

    組成了成人的身體。

  • In fact, even as I stand here before you,

    有些細胞需要分裂數千次。

  • all throughout my body, cells are furiously replenishing

    事實上,即使我站在各位面前,

  • to, well, keep me standing here before you.

    我整個身體的細胞正瘋狂地補充,

  • So every time a cell divides, all of its DNA has to be copied,

    讓我能夠持續站在你們面前。

  • all of the coding DNA inside of those chromosomes,

    每當一個細胞分裂, 它所有的 DNA 都會被複製,

  • because that carries the vital operating instructions

    那些染色體中所有編碼的 DNA,

  • that keep our cells in good working order,

    因為那帶有極重要的運作指示,

  • so my heart cells can keep a steady beat,

    讓我們的細胞 能處於良好的工作狀態,

  • which I assure you they're not doing right now,

    這麼一來我的心臟細胞 才能保持穩定的心跳,

  • and my immune cells

    我向各位保證,它們現在並沒做到,

  • can fight off bacteria and viruses,

    而我的免疫細胞,

  • and our brain cells can save the memory of our first kiss

    能擊退細菌和病毒,

  • and keep on learning throughout life.

    我們的頭腦細胞 能儲存我們初吻的記憶,

  • But there is a glitch in the way DNA is copied.

    並在整個人生中持續學習。

  • It is just one of those facts of life.

    但複製 DNA 的方式有個小毛病,

  • Every time the cell divides and the DNA is copied,

    僅是生命的事實之一。

  • some of that DNA from the ends gets worn down and shortened,

    每當細胞分裂、DNA 被複製,

  • some of that telomere DNA.

    某些末端 DNA 會磨損縮短,

  • And think about it

    一些端粒的 DNA。

  • like the protective caps at the ends of your shoelace.

    可以用這方式來想:

  • And those keep the shoelace, or the chromosome, from fraying,

    就像你的鞋帶末端的保護套。

  • and when that tip gets too short, it falls off,

    它們能讓鞋帶或染色體不會被磨損,

  • and that worn down telomere sends a signal to the cells.

    當尖端變得太短時,它就會脫落,

  • "The DNA is no longer being protected."

    而那被磨損掉的端粒 就會發送一個訊號給細胞。

  • It sends a signal. Time to die.

    「這 DNA 不再受到保護。」

  • So, end of story.

    它發出訊號。是死亡的時候了。

  • Well, sorry, not so fast.

    所以,故事結束。

  • It can't be the end of the story,

    抱歉,沒那麼快。

  • because life hasn't died off the face of the earth.

    故事不可能這樣結束,

  • So I was curious:

    因為生命還沒從地球表面上消逝。

  • if such wear and tear is inevitable,

    所以我很好奇:

  • how on earth does Mother Nature make sure

    如果這種損耗是無可避免的,

  • we can keep our chromosomes intact?

    大自然到底要如何確保

  • Now, remember that little pond scum critter Tetrahymena?

    我們能保持不讓染色體受損?

  • The craziest thing was, Tetrahymena cells never got old and died.

    還記得那池塘浮渣小生物四膜蟲嗎?

  • Their telomeres weren't shortening as time marched on.

    最瘋狂的是,四膜蟲細胞 從來不會變老或死亡。

  • Sometimes they even got longer.

    牠們的端粒並不會隨時間而變短。

  • Something else was at work,

    有時甚至還會變長。

  • and believe me, that something was not in any textbook.

    還有某樣東西在運作,

  • So working in my lab with my extraordinary student Carol Greider --

    相信我,那某樣東西 並不在任何教科書中。

  • and Carol and I shared the Nobel Prize for this work --

    所以,我和傑出學生 凱洛葛萊德在實驗室中合作──

  • we began running experiments

    凱洛和我共享 這項研究贏得的諾貝爾獎──

  • and we discovered cells do have something else.

    我們開始進行實驗,

  • It was a previously undreamed-of enzyme

    我們發現細胞的確有其他的東西。

  • that could replenish, make longer, telomeres,

    是先前意想不到的酶(酵素),

  • and we named it telomerase.

    它能補充端粒,讓端粒更長,

  • And when we removed our pond scum's telomerase,

    我們將它命名為「端粒酶」。

  • their telomeres ran down and they died.

    當我們移除池塘浮渣的端粒酶後,

  • So it was thanks to their plentiful telomerase

    牠們的端粒就會耗盡而死亡。

  • that our pond scum critters never got old.

    所以要歸功於豐富的端粒酶,

  • OK, now, that's an incredibly hopeful message

    我們的池塘浮渣才能永生不老。

  • for us humans to be receiving from pond scum,

    那是我們人類能從池塘浮渣身上

  • because it turns out

    得到的一個非常有希望的訊息,

  • that as we humans age, our telomeres do shorten,

    因為結果發現,

  • and remarkably, that shortening is aging us.

    隨著我們人類年紀增長, 我們的端粒確實會變短,

  • Generally speaking, the longer your telomeres,

    很驚人的是, 那縮短現象讓我們變老。

  • the better off you are.

    一般來說,你的端粒越長,

  • It's the overshortening of telomeres

    你的狀況就會越好。

  • that leads us to feel and see signs of aging.

    是端粒過度減短的現象

  • My skin cells start to die

    導致我們會感到及看到老化的徵象。

  • and I start to see fine lines, wrinkles.

    我的皮膚細胞開始死亡,

  • Hair pigment cells die.

    我就會開始看到線條、皺紋。

  • You start to see gray.

    頭髮色素細胞死亡,

  • Immune system cells die.

    你就會開始看到白髮。

  • You increase your risks of getting sick.

    免疫細胞死亡,

  • In fact, the cumulative research from the last 20 years

    你被攻擊的風險就會提升。

  • has made clear that telomere attrition

    事實上,過去二十年所累積的研究

  • is contributing to our risks of getting cardiovascular diseases,

    清楚地指出,

  • Alzheimer's, some cancers and diabetes,

    端粒損耗可能造成罹患

  • the very conditions many of us die of.

    像是:心血管疾病、阿滋海默症、

  • And so we have to think about this.

    某些癌症,以及糖尿病等 許多致死疾病的風險。

  • What is going on?

    所以我們得要想想這一點。

  • This attrition,

    發生了什麼事?

  • we look and we feel older, yeah.

    這種損耗,

  • Our telomeres are losing the war of attrition faster.

    我們看起來且感覺起來變老了。

  • And those of us who feel youthful longer,

    我們的端粒在 損耗之戰中敗退得很快。

  • it turns out our telomeres are staying longer

    至於覺得年輕時間比較長的人,

  • for longer periods of time,

    結果發現是端粒能留比較久,

  • extending our feelings of youthfulness

    比較長的時間,

  • and reducing the risks of all we most dread

    延長我們對於年輕的感覺,

  • as the birthdays go by.

    並減少我們隨著每個生日過去

  • OK,

    而最害怕的那些風險。

  • seems like a no-brainer.

    好。

  • Now, if my telomeres are connected

    似乎很簡單。

  • to how quickly I'm going to feel and get old,

    如果我的端粒和我多快感到變老

  • if my telomeres can be renewed by my telomerase,

    及實際變老是有關聯的,

  • then all I have to do to reverse the signs and symptoms of aging

    如果我能用端粒酶來復原端粒,

  • is figure out where to buy that Costco-sized bottle

    那麼若我想要反轉 老化的徵兆和症狀,

  • of grade A organic fair trade telomerase, right?

    就是要找個地方 買像好市多那樣超大罐、

  • Great! Problem solved.

    A 級、有機、公平貿易的 端粒酶,對吧?

  • (Applause)

    好極了!問題解決。

  • Not so fast, I'm sorry.

    (掌聲)

  • Alas, that's not the case.

    很抱歉,沒那麼快。

  • OK. And why?

    唉,並不是那樣的。

  • It's because human genetics has taught us

    那為什麼呢?

  • that when it comes to our telomerase,

    因為人類遺傳學教導我們,

  • we humans live on a knife edge.

    談到我們的端粒酶時,

  • OK, simply put,

    我們人類是住在刀緣上的。

  • yes, nudging up telomerase does decrease the risks of some diseases,

    簡單來說,

  • but it also increases the risks of certain and rather nasty cancers.

    是的,增加端粒酶的確 可以減少一些疾病的風險,

  • So even if you could buy that Costco-sized bottle of telomerase,

    但同時也會增加某些 很糟糕的癌症的風險。

  • and there are many websites marketing such dubious products,

    所以,就算你能買到 像好市多那樣超大罐的端粒酶,

  • the problem is you could nudge up your risks of cancers.

    有許多網站在行銷這類可疑的產品,

  • And we don't want that.

    問題是你有可能增加罹癌的風險。

  • Now, don't worry,

    我們不想要那樣。

  • and because, while I think it's kind of funny that right now,

    別擔心,

  • you know, many of us may be thinking, well, I'd rather be like pond scum.

    因為,雖然我覺得有點好笑,

  • (Laughter)

    也許此刻很多人正想著, 我寧可像池塘浮渣一樣。

  • There is something for us humans

    (笑聲)

  • in the story of telomeres and their maintenance.

    在這關於端粒以及維護端粒的真相中

  • But I want to get one thing clear.

    還是有我們人類可以學習之處。

  • It isn't about enormously extending human lifespan

    但我想先澄清一件事。

  • or immortality.

    重點並不是將人類壽命期間延長很多

  • It's about health span.

    或是永生不死。

  • Now, health span is the number of years of your life

    重點是「健康期間」。

  • when you're free of disease, you're healthy, you're productive,

    健康期間,就是你人生中有多少年

  • you're zestfully enjoying life.

    是沒有疾病、很健康、有生產力、

  • Disease span, the opposite of health span,

    能夠熱情享受人生的。

  • is the time of your life spent feeling old and sick and dying.

    相對於健康期間的「疾病期間」,

  • So the real question becomes,

    指的就是你人生中有多長時間 覺得自己老、病、和垂死。

  • OK, if I can't guzzle telomerase,

    所以,真正的問題變成是,

  • do I have control over my telomeres' length

    如果我無法狂飲端粒酶,

  • and hence my well-being, my health,

    我是否能控制端粒酶的長度,

  • without those downsides of cancer risks?

    進而控制我的福祉、我的健康,

  • OK?

    而沒有癌症風險的壞處?

  • So, it's the year 2000.

    好嗎?

  • Now, I've been minutely scrutinizing little teeny tiny telomeres

    所以,那是 2000 年。

  • very happily for many years,

    多年來,我很快樂地、分分鐘鐘地

  • when into my lab walks a psychologist named Elissa Epel.

    持續仔細觀察著那些極微小的端粒,

  • Now, Elissa's expertise is in the effects of severe, chronic psychological stress

    直到有一天,名叫伊莉莎埃佩爾的 心理學家走入了我的實驗室。

  • on our mind's and our body's health.

    伊莉莎的專長在於嚴重慢性心理壓力

  • And there she was standing in my lab,

    對於我們身、心健康的影響。

  • which ironically overlooked the entrance to a mortuary, and --

    她出現在我的實驗室,

  • (Laughter)

    很諷刺的是從實驗室 可以眺望停屍間的入口,而且──

  • And she had a life-and-death question for me.

    (笑聲)

  • "What happens to telomeres in people who are chronically stressed?"

    她有個生死問題要問我。

  • she asked me.

    「有慢性壓力的人, 他們的端粒會發生什麼事?」

  • You see, she'd been studying caregivers,

    她這樣問我。

  • and specifically mothers of children with a chronic condition,

    她一直在研究照護者,

  • be it gut disorder, be it autism, you name it --

    特別慢性病孩童的母親,

  • a group obviously under enormous and prolonged psychological stress.

    可能是腸病,可能是自閉症, 任何你想得到的──

  • I have to say, her question

    這個族群很顯然處在 巨大且長期的心理壓力之下。

  • changed me profoundly.

    我不得不說,

  • See, all this time I had been thinking of telomeres

    她的問題深深改變了我。

  • as those miniscule molecular structures that they are,

    一直以來,

  • and the genes that control telomeres.

    我從小分子結構的角度來思考端粒

  • And when Elissa asked me about studying caregivers,

    和控制端粒的基因。

  • I suddenly saw telomeres in a whole new light.

    當伊莉莎問我 關於照護者的問題時,

  • I saw beyond the genes and the chromosomes

    我突然從全新的角度去看端粒。

  • into the lives of the real people we were studying.

    我超越了基因和染色體,

  • And I'm a mom myself,

    看到我們所研究的真實人類的生活。

  • and at that moment,

    我自己也是個母親,

  • I was struck by the image of these women

    在那一刻,

  • dealing with a child with a condition

    我被這個影像震撼了:

  • very difficult to deal with, often without help.

    這些女子通常靠一己之力照顧孩子,

  • And such women, simply,

    有非常難處理的疾病的孩子, 往往沒有幫手。

  • often look worn down.

    這類女子,很顯而易見,

  • So was it possible their telomeres were worn down as well?

    經常看起來是耗盡了精力的模樣。

  • So our collective curiosity went into overdrive.

    有沒有可能她們的端粒 也被損耗掉了呢?

  • Elissa selected for our first study a group of such caregiving mothers,

    我們共同的好奇心 促使我們加倍努力。

  • and we wanted to ask: What's the length of their telomeres

    伊莉莎為我們的第一項研究 選了一群照護母親,

  • compared with the number of years that they have been caregiving

    我們想要問:她們的端粒長度

  • for their child with a chronic condition?

    和她們照顧有慢性疾病孩童多少年

  • So four years go by

    有什麼關聯?

  • and the day comes when all the results are in,

    所以,經過了四年,

  • and Elissa looked down at our first scatterplot

    所有結果都進來的那一天,

  • and literally gasped,

    伊莉莎看著我們的 第一張資料散佈圖,

  • because there was a pattern to the data,

    真的是倒抽了一口氣,

  • and it was the exact gradient that we most feared might exist.

    因為資料的確呈現出了模式,

  • It was right there on the page.

    且正是我們最怕存在的斜線。

  • The longer, the more years that is,

    就在那裡,呈現在那一頁上。

  • the mother had been in this caregiving situation,

    母親在照護情境中的時間

  • no matter her age,

    越久、越多年,

  • the shorter were her telomeres.

    不論她幾歲,

  • And the more she perceived

    她的端粒都會比較短。

  • her situation as being more stressful,

    而且,她若越是感受到

  • the lower was her telomerase and the shorter were her telomeres.

    她所處的情境有很大的壓力,

  • So we had discovered something unheard of:

    她的端粒酶就會越少, 她的端粒也就會越短。

  • the more chronic stress you are under, the shorter your telomeres,

    所以我們發現了以前沒聽過的事:

  • meaning the more likely you were to fall victim to an early disease span

    越是在長期壓力之下, 你的端粒就會越短,

  • and perhaps untimely death.

    意味著,你越可能很早就罹患疾病,

  • Our findings meant that people's life events

    也可能最終會比較早死。

  • and the way we respond to these events

    我們的發現意味著, 人一生經歷的事件、

  • can change how you maintain your telomeres.

    以及我們對這些事件的因應方式,

  • So telomere length wasn't just a matter of age counted in years.

    能夠改變你的端粒的維護狀況。

  • Elissa's question to me,

    所以端粒長度並不只是 把年齡換算成年數。

  • back when she first came to my lab, indeed had been a life-and-death question.

    伊莉莎一開始到我實驗室問的問題,

  • Now, luckily, hidden in that data there was hope.

    的確是個生死的問題。

  • We noticed that some mothers,

    幸運的是,在那些 資料中也藏有希望。

  • despite having been carefully caring for their children for many years,

    我們注意到,有些母親

  • had been able to maintain their telomeres.

    雖然多年來都一直 很細心照顧她們的孩子,

  • So studying these women closely revealed that they were resilient to stress.

    卻仍然能維持著她們的端粒。

  • Somehow they were able to experience their circumstances

    仔細研究這些女性, 發現她們對壓力的恢復力很強。

  • not as a threat day in and day out

    她們能夠以某種方式,

  • but as a challenge,

    不一天到晚視她們 所經歷的情況為威脅,

  • and this has led to a very important insight for all of us:

    而視為是挑戰,

  • we have control over the way we age

    這就導出了對於我們所有人 都非常重要的洞見:

  • all the way down into our cells.

    我們能夠控制我們老化的方式

  • OK, now our initial curiosity became infectious.

    且一路控制到我們的細胞。

  • Thousands of scientists from different fields

    我們一開始的好奇心 變成是有感染力的。

  • added their expertise to telomere research,

    數以千計來自不同領域的科學家

  • and the findings have poured in.

    把他們的專長加到了 端粒的研究當中,

  • It's up to over 10,000 scientific papers and counting.

    大量的發現湧入。

  • So several studies rapidly confirmed our initial finding

    有超過一萬份科學論文, 且還在增加中。

  • that yes, chronic stress is bad for telomeres.

    所以,有許多研究很快就 確認了我們最初的發現,

  • And now many are revealing

    是的,長期壓力對於端粒有害。

  • that we have more control over this particular aging process

    現在,許多研究指出,