Venki Ramakrishnan

But later stem cells, later in development, they specialize. So some stem cells can only make skin and hair. Others can only make cells of the nervous system. Of course, there are many different types, but still a subset. Others can only make cells of the blood, and that includes the entire immune system and our red blood cells. So these stem cells themselves

But later stem cells, later in development, they specialize. So some stem cells can only make skin and hair. Others can only make cells of the nervous system. Of course, there are many different types, but still a subset. Others can only make cells of the blood, and that includes the entire immune system and our red blood cells. So these stem cells themselves

decline with age because many of them go into senescence. And so you get a depletion of stem cells. And the quality of the remaining stem cells is also not as diverse and not as good because they're often descended from a few clones which don't have necessarily the optimal properties. So that's another cause of aging. And that leads to tissue loss.

decline with age because many of them go into senescence. And so you get a depletion of stem cells. And the quality of the remaining stem cells is also not as diverse and not as good because they're often descended from a few clones which don't have necessarily the optimal properties. So that's another cause of aging. And that leads to tissue loss.

For example, a common problem with aging is loss of muscle and frailty. So you can see that at every level there's an effect, but each level is not independent. They all interact with each other. And so there's this complicated web of things happening at different levels of complexity.

For example, a common problem with aging is loss of muscle and frailty. So you can see that at every level there's an effect, but each level is not independent. They all interact with each other. And so there's this complicated web of things happening at different levels of complexity.

Yeah, it does. People have made a lot of progress. For example, I mentioned senescent cells. So amazingly, people have been able to target senescent cells using some particular biomarkers, things characteristic of senescent cells. And when they destroy senescent cells in, say, mice, aging mice, the symptoms of aging improve in those mice. And so that's one way.

Yeah, it does. People have made a lot of progress. For example, I mentioned senescent cells. So amazingly, people have been able to target senescent cells using some particular biomarkers, things characteristic of senescent cells. And when they destroy senescent cells in, say, mice, aging mice, the symptoms of aging improve in those mice. And so that's one way.

that one of the more exciting and more challenging ways to deal with aging is to reprogram cells. So you take cells and you reprogram them so they go slightly backwards in development. So effectively they become like stem cells. So you're reactivating stem cells for different types of tissues.

that one of the more exciting and more challenging ways to deal with aging is to reprogram cells. So you take cells and you reprogram them so they go slightly backwards in development. So effectively they become like stem cells. So you're reactivating stem cells for different types of tissues.

And that, I would have thought that was almost science fiction, but recently in the last few years, a number of papers have come out doing exactly this in mice. And showing that the symptoms of aging have improved in these mice. But of course, reprogramming cells raises the risk of cancer. It also raises the risk of how do you do this in a body in a holistic way?

And that, I would have thought that was almost science fiction, but recently in the last few years, a number of papers have come out doing exactly this in mice. And showing that the symptoms of aging have improved in these mice. But of course, reprogramming cells raises the risk of cancer. It also raises the risk of how do you do this in a body in a holistic way?

Because our different organs age at different rates. And how do you ensure a kind of systemic recovery? rejuvenation, if you like. I think people don't like that word. Some people like it. Just to popularize it. So it's a challenging but hard problem. It's another way to maybe tackle some aspects of aging.

Because our different organs age at different rates. And how do you ensure a kind of systemic recovery? rejuvenation, if you like. I think people don't like that word. Some people like it. Just to popularize it. So it's a challenging but hard problem. It's another way to maybe tackle some aspects of aging.

It's unlikely to, although that also has a real scientific basis. And many decades ago, people actually connected a young mouse with an old mouse.

It's unlikely to, although that also has a real scientific basis. And many decades ago, people actually connected a young mouse with an old mouse.

By connecting their blood systems together. And some decades ago, people found that actually the old mouse benefited from the young blood And the young mouse actually deteriorated as a result of the old blood. And so this was an amazing finding and, of course, raised all sorts of questions like what's going on in blood and what are the factors in blood.

By connecting their blood systems together. And some decades ago, people found that actually the old mouse benefited from the young blood And the young mouse actually deteriorated as a result of the old blood. And so this was an amazing finding and, of course, raised all sorts of questions like what's going on in blood and what are the factors in blood.

Maybe there are factors that prevent damage or factors that cause damage in old blood or maybe activate stem cells in young blood. There could be a number of scenarios. And so there's a huge field that's looking for these factors and trying to identify what is different about young and old blood. And of course, of the many differences, not all of them will be relevant.

Maybe there are factors that prevent damage or factors that cause damage in old blood or maybe activate stem cells in young blood. There could be a number of scenarios. And so there's a huge field that's looking for these factors and trying to identify what is different about young and old blood. And of course, of the many differences, not all of them will be relevant.