Aug 15th 2018

Ageing in human cells successfully reversed in the lab

by Lorna Harries and Matt Whiteman

 

Lorna Harries is Associate Professor in Molecular Genetics, University of Exeter

Matt Whiteman is Professor of Experimental Therapeutics, University of Exeter

 

The ability to reverse ageing is something many people would hope to see in their lifetime. This is still a long way from reality, but in our latest experiment, we have reversed the ageing of human cells, which could provide the basis for future anti-degeneration drugs.

Ageing can be viewed as the progressive decline in bodily function and is linked with most of the common chronic diseases that humans suffer from, such as cancer, diabetes and dementia. There are many reasons why our cells and tissues stop functioning, but a new focus in the biology of ageing is the accumulation of “senescent” cells in the tissues and organs.

Senescent cells are older deteriorated cells that do not function as they should, but also compromise the function of cells around them. Removal of these old dysfunctional cells has been shown to improve many features of ageing in animals such as the delayed onset of cataracts.

We still don’t fully understand why cells become senescent as we age, but damage to DNA, exposure to inflammation and damage to the protective molecules at the end of the chromosomes – the telomeres – have all been suggested.

More recently, people have suggested that one driver of senescence may be loss of our ability to turn genes on and off at the right time and in the right place.

A senescent cell. Eva Latorre, Author provided

One gene, many messages

As we age, we lose our ability to control how our genes are regulated. Each cell in the body contains all the information needed for life, but not all genes are switched on in all tissues or under all conditions. This is one of the ways that a heart cell is different from a kidney cell, despite the fact they contain the same genes.

When a gene is activated by signals from inside or outside the cell, it makes a molecular message (called an RNA) that contains all the information needed to make whatever that gene makes. We now know that over 95% of our genes can actually make several different types of messages, depending on the needs of the cell.

A good way to think about this is to consider each gene as a recipe. You could make either a vanilla sponge, or a chocolate cake, depending on whether you include the chocolate. Our genes can work like this. The decision as to which type of message is produced at any given time is made by a group of about 300 proteins called “splicing factors”.

As we age, the amount of splicing factors we are able to make declines. This means that aged cells are less able to switch genes on and off to respond to changes in their environment. We and others have shown that the levels of these important regulators decline in blood samples from elderly humans, and also in isolated human senescent cells of different tissue types.

Rejuvenating old cells

We have been looking for ways to turn the splicing factors back on. In our new work, we showed that by treating old cells with a chemical that releases small amounts of hydrogen sulphide, we were able to increase levels of some splicing factors, and to rejuvenate old human cells.

Hydrogen sulphide is a molecule that is found naturally in our bodies and has been shown to improve several features of age-related disease in animals. But it can be toxic in large amounts, so we needed to find a way to deliver it directly to the part of the cell where it is needed.

By using a “molecular postcode” we have been able to deliver the molecule directly to the mitochondria, the structures that produce energy in cells, where we think it acts, allowing us to use tiny doses, which are less likely to cause side effects.

We are hopeful that in using molecular tools such as this, we will be able to eventually remove senescent cells in living people, which may allow us to target multiple age-related diseases at once. This is some way in the future yet, but it’s an exciting start.

Lorna Harries, Associate Professor in Molecular Genetics, University of Exeter and Matt Whiteman, Professor of Experimental Therapeutics, University of Exeter

This article was originally published on The Conversation. Read the original article.

Browse articles by author

More Essays

Jun 27th 2020
An essay about the "the enormously influential 1940 'Head of Christ' painting by evangelical Warner E. Sallman" pictured below.
Jun 17th 2020
EXTRACT: "The diverse, non-human life forms that live in our guts – known as our microbiome – are crucial to our health. A disrupted balance of these contribute to a range of disorders and diseases, including obesity, diabetes, inflammatory bowel disease. It could even affect our mental health..... It’s well known that the microbes living in our guts are altered through diet. For example, including dietary fibre and dairy products in our diets encourages the growth of beneficial bacteria. But mounting evidence suggests that exercise can also modify the types of bacteria that reside within our guts."
Jun 13th 2020
EXTRACT: "Bonhoeffer’s life holds an important lesson for us today, regardless of our religious affiliation or lack thereof. And simply put it is this: you are called upon; you are called on behalf of your neighbor. When you are called to be responsible that is not an obligation which you can decline, discharge or acquit yourself of – it is an infinite responsibility, a “forever commitment” as Charles Blow recently put it. And we all must be prepared to make any sacrifice necessary when we are called."
Jun 11th 2020
EXTRACT: "People differ substantially in how much they’re affected by experiences in their lives. Some people seem to be more affected by daily stress, or the loss of someone close to them. On the other hand, some people seem to get through the same experiences relatively unscathed. Similarly, some people benefit strongly from counselling, or having a support system of close family and friends. Others seem better able to manage on their own. But understanding why some people are more sensitive than others isn’t just a question of how they were raised, and the experiences they’ve been through. In fact, previous research has found that some people in general seem more sensitive to what they experience – and some are generally less sensitive."
Jun 7th 2020
EXTRACT: " The root causes of anthropogenic climate change – which has led to the endangering of countless species across the globe – cannot be adequately grasped in isolation from the technological application of modern science. While Swedish activist Greta Thunberg was certainly justified in calling upon American legislators to “unite behind the science,” neither can we overlook the culpability of science in bringing about the environmental crisis. "
May 23rd 2020
EXTRACT: "The QAnon movement began in 2017 after someone known only as Q posted a series of conspiracy theories about Trump on the internet forum 4chan. QAnon followers believe global elites are seeking to bring down Trump, whom they see as the world’s only hope to defeat the “deep state.” OKM is part of a network of independent congregations (or ekklesia) called Home Congregations Worldwide (HCW). The organization’s spiritual adviser is Mark Taylor, a self-proclaimed “Trump Prophet” and QAnon influencer with a large social media following on Twitter and YouTube."
May 23rd 2020
EXTRACT: "The aim of my research for the Understanding Unbelief programme was to investigate the worldviews of non-believers, since little is known about the diversity of these non-religious beliefs, and what psychological functions they serve. I wanted to explore the idea that while non-believers may not hold religious beliefs, they still hold distinct ontological, epistemological and ethical beliefs about reality, and the idea that these secular beliefs and worldviews provide the non-religious with equivalent sources of meaning, or similar coping mechanisms, as the supernatural beliefs of religious individuals."
May 22nd 2020
EXTRACT: "Psalm 91, for example, reassures believers that God will protect them from “the pestilence that walketh in darkness… A thousand shall fall at thy side, and ten thousand at thy right hand; but it shall not come nigh thee”.............Luther was a devout believer but insisted that religious faith had to be joined with practical, physical defences against sickness. It was a good Christian’s duty to work to keep themselves and others safe, rather than relying solely on the protection of God. "
May 22nd 2020
EXTRACT: "Evidence from this study shows clearly that eating foods rich in flavonoids over your lifetime is significantly linked to reducing Alzheimer’s disease risk. However, their consumption will be even more beneficial alongside other lifestyle changes, such as quitting smoking, managing a healthy weight and exercising."
May 5th 2020
EXTRACT: "It’s possible that the answers to questions like, “how do I live a virtuous life?” or “how do we build a good society?” are not the same as they were a few weeks ago."
May 2nd 2020
EXTRACT: "Strangely, those with strong beliefs tend to be admired. The human mind hates uncertainty, so it is comforting to be told what to think, and to form settled opinions. But it is not rational. As the philosopher Bertrand Russell wrote: “The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.”
Apr 21st 2020
Extract: "Humans, Boccaccio seems to be saying, can think of themselves as upstanding and moral – but unawares, they may show indifference to others. We see this in the 10 storytellers themselves: They make a pact to live virtuously in their well-appointed retreats. Yet while they pamper themselves, they indulge in some stories that illustrate brutality, betrayal and exploitation. Boccaccio wanted to challenge his readers, and make them think about their responsibilities to others. “The Decameron” raises the questions: How do the rich relate to the poor during times of widespread suffering? What is the value of a life? In our own pandemic, with millions unemployed due to a virus that has killed thousands, these issues are strikingly relevant.
Apr 20th 2020
Extract: "If we do not seize this crisis as a moment for transformation, then we will have lost the war. If doing so requires reviving notions of collective guilt and responsibility – including the admittedly uncomfortable view that every one of us is infinitely responsible, then so be it; as long we do not morally cop out by blaming some group as the true bearers of sin, guilt, and God’s heavy judgment. A pandemic clarifies the nature of action: that with our every act we answer to each other. In that light, we have a duty to seize this public crisis as an opportunity to reframe our mutual responsibility to one another and the world."
Apr 16th 2020
EXTRACT: "Death is the common experience which can make all members of the human race feel their common bonds and their common humanity."
Apr 7th 2020
EXTRACT: "A crisis such as this one demands that we exercise what the philosopher Immanuel Kant called the ‘public use of reason’ – as opposed to merely the ‘private use of reason’ where, briefly put, the expert, the specialist is tasked with resolving a defined problem. The private use of reason is sufficient when we are dealing with a problem that can be solved by simply applying the appropriate expertise...............The public use of reason asks: how we are defining the problem? Is our definition – our conceptualization of the problem – perhaps part of the problem itself? Is this pandemic solely a problem of public health, or is it also a problem of extreme economic inequality? ..............Since this crisis began, the greatest failure of the administration is not the denial, the lies, the lack of preparedness, but the inability to rally and unify the nation against this common threat, the lack of genuine leadership – Trump’s utter inability to bring the nation together."
Apr 5th 2020
EXTRACT: "Rarely has an architectural experiment aroused such extremes of ire and admiration. One side is convinced the house is a masterpiece. The other expresses brutal condemnation of the entire project (leaky roof, danger of flooding, too-hot, too-cold interiors depending on the American Midwest weather).........Farnsworth encapsulated her personal ambiguity in her comment to a Newsweek interviewer: “This handsome pavilion I own is almost totally unworkable.” She told one journalist, “ … all I got was this glib, false sophistication. The conception of a house as a glass cage suspended in air is ridiculous.”
Apr 1st 2020
Ambrogio Lorenzetti, Effects of Good Government fresco, Palazzo Pubblico, Siena.
Mar 29th 2020
EXTRACT: "The coronavirus crisis has forced us to look at our behaviour in a way that we’re not used to. We are being asked to act in the collective good rather than our individual preservation and interest. Even for those of us with the best of intentions, this is not so easy."
Mar 23rd 2020
EXTRACT: "In March 2020, my sister Nancy and I did something that, as scholars, we had never done before: we wrote about ourselves, comparing our own experiences receiving cancer care on either side of the Atlantic. As we recently reported in the BMJ, much of our experience is similar. As twins, we both have the same form of cancer. Both of us received excellent treatment in well-established university teaching hospitals. Both of us are now in remission. But there is a glaring difference. Nancy lives in the US, covered under a good private healthcare scheme. I live in the UK, covered by the NHS."
Mar 21st 2020
EXTRACT: "In philosophy, individualism is closely linked with the concept of freedom. As soon as restrictive measures were imposed in Italy, many people felt that their freedom was threatened and started to assert their individuality in various ways. Some disagreed with the necessity of cancelling group gatherings and organised unofficial ones themselves. Others continued to go out and live as they always did. We often assume that freedom is to do as we choose, and that is contrasted with being told what to do. As long as I am doing what the government tells me, I am not free. I am going out, not because I want to, but because that shows I am free. But there is another route to freedom..........."