General Science => Question of the Week => Topic started by: thedoc on 02/10/2012 17:01:29
Title: QotW - 12.09.30 - Would self bone marrow transplants reverse aging?
Post by: thedoc on 02/10/2012 17:01:29
I was trying to think of a way to reverse aging. And I thought about all errors that accumulate in your DNA over the years and I wandered what would happen if you donated blood at an early age and then received transfusions of your own blood when you were older?
I assume there are many things I am over looking like immunity that you acquire when you're older and the fact that when you get a blood transfusion from someone else it obviously doesn't replace your DNA.
But maybe a bone marrow transplant, or some way of infusing DNA without errors or repairing your DNA in someway.
Also I figure there is something I am not considering when it comes to factors such as different localities in the body, I know in Chimerism you can have the body pumping out different sets of genes in different parts of the body.
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Title: QotW - 12.09.30 - Would self bone marrow transplants reverse aging?
Post by: thedoc on 02/10/2012 17:01:29
We answered this question on the show...
We put this to I'm Professor Tom Kirkwood at Newcastle University... Tom - Ageing is complicated. We know that the underlying reason that the body ages is that as we live our lives, our cells accumulate a whole host of small faults, damage affects the DNA, proteins, membranes that make up the cells. So basically, the ageing process is driven by things going wrong, cells become damaged, and that also affects the stem cells of the body. It used to be thought that stem cells could keep going more or less indefinitely, but actually, we know that stem cells that underpin many parts of the body do themselves experience some form of intrinsic ageing. [img float=right]/forum/copies/RTEmagicC_Bone_marrow_biopsy.jpg.jpg[/img]So, in theory, one might think that a good way to combat some of the effects of ageing would be to replace the cells within the body that had been damaged by this accumulation of faults with cells that are somehow less damaged. And the idea that you could use your own banked cells from earlier in your life is an interesting one. There are problems with that though, ageing affect all the cells and tissues of the body, so simply rejuvenating one particular population of cells maybe do it for that group of cells, but it’s not going to do anything about all of the rest. So, it’s not going to be a universal effect. Hannah - Self-bone marrow transplant may not reverse the whole body ageing effect, but it could be used to reverse a specific aspect of it. Bone marrow stem cells replicate throughout your life to produce your blood cells including white blood cells such lymphocytes which act as soldiers, fighting off infection in your body. Your immune system is one function of your body profoundly affected by ageing which is why older people are more likely to succumb to infections. So, could injecting yourself with your younger fresher bone marrow stem cells keep the flu at bay in later years? Anne - My name is Anne Corcoran. I'm a Research Group Leader at the Babraham Institute in Cambridge and I work on how the body fights infection. Older lymphocytes grow more slowly and make far fewer new antibodies, the proteins that recognise and get rid of infections. So, a younger version of your bone marrow that still has younger stem cells to generate younger lymphocytes might help your immune system to fight infection. Hannah - In which case, should all under 40s be rushing to have their bones drilled in order to harvest their bone marrow stem cells and bank them to help boost their immune systems later in life? Anne - Taking a bone marrow sample is not a trivial procedure. It’s not like taking a blood sample. Also, we don’t yet know exactly to what effects of long term storage of bone marrow are on its efficiency. Hannah - Instead, Anne suggests, boosting the older immune system by reducing stress, getting enough sleep, having a healthy diet high in antioxidants, exercise, and some good old physical contact like hugs and handshakes to release endorphins and boost the production of antibodies.
Title: Re: QotW - 12.09.30 - Would self bone marrow transplants reverse aging?
Post by: kckuhns on 24/09/2012 06:45:16
A bone marrow transplant is effective for certain blood-related disease. But for repairing aged, 'broken' DNA a more complex approach is needed. I personally have absolutely no medical knowledge whatsoever, but I did once stay at a Holiday Inn. So my layman response is that it is feasible to reverse cellular DNA damage by delivering replacement/ undamaged genetically compatible DNA to the tens of trillion cells throughout the human body. So to start, yes, it would be helpful to set aside stem [undifferentiated] cells at a very early age, for example, to cryogenically preserve these cells taken from your own umbilical cord after birth. At later stages in life, this undamaged DNA could be harvested, replicated, then delivered to your body through some sort of vector, such as in viral-mediated gene therapy. I suppose there will eventually be non-viral gene delivery mechanisms developed in the future, such as chemical, mechanical [hydrodynamic?] or perhaps using nanotechnology....microscopic delivery bots.
Title: Re: QotW - 12.09.30 - Would self bone marrow transplants reverse aging?
Post by: evan_au on 30/09/2012 00:19:44
The most common cell in blood is red blood cells. These have no DNA, do not replicate, and have a very short lifetime in the body, so transfusing these will have minimal benefit. White blood cells are les frequent, and rather specialised, but have a full set of DNA. However, all the blood cells originate in the marrow, so treating the marrow could be a useful therapy for genetic diseases affecting the blood.
Every time a cell divides, there is a small chance that a random transcription error will occur which is not corrected by the cell. http://en.wikipedia.org/wiki/DNA_Polymerase#Function
This is especially important for cells which divide frequently throughout life, including stem cells and sperm-generating cells. A recent study showed that sperm accumulate an average of 2 extra random mutations for every additional year of a man's age.
One day we may be able to safely correct a specific genetic defect in a cell, but this works best for systematic mutations which are identical in every cell of the body, not for random mutations which may be different in every cell line in the body. eg see: http://en.wikipedia.org/wiki/Zinc_finger_nucleases#Gene_therapy
Reliably delivering this therapy to every cell in the body would be a real challenge. So perhaps it could be applied to stem cells in vitro, which could then be multiplied and reintroduced into the adult body (after checks for successful DNA correction, lack of cancerous behavior, specialisation for treating certain tissues, etc).
To avoid buildup of random mutations, the therapy is best applied to stored stem cells which just have the target systematic mutation, but minimal random mutations. This suggests a stem cell which is captured at a young age. Perhaps collected at birth, such as from the placenta. Over time, the "corrected" stem cells may be able to take over from the "faulty" ones.
There has been recent progress in picking up fetal white blood cells from the mother's circulation, even before birth. In the long term, perhaps the best time to apply gene therapy may be before birth?
Title: Re: QotW - 12.09.30 - Would self bone marrow transplants reverse aging?
Post by: CliffordK on 30/09/2012 01:45:15
Cord Blood, of course, gives a "marrow transplant", rather than just replacing the blood.
However, to be effective, one would have to irradiate one's own bone marrow, which is a brutal, and dangerous procedure, and would not be a good procedure for "anti-aging".
And, the most effective bone marrow transplants are from close matches, not perfect matches, thus causing a minimal amount of graft vs host disease. Thus, one might be better off using one's sibling's cord blood, rather than one's own autologous donation.
Nonetheless, one is only rejuvenating one's own blood. There are many other cells in the body such as skin cells that would still be OLD.
Title: Re: QotW - 12.09.30 - Would self bone marrow transplants reverse aging?
Post by: chris on 02/10/2012 20:29:48
I don't think you'd necessarily have to ablate your own bone marrow with radiation before a transplant, Clifford, assuming you were infusing your own cells. The new, youthful, cells would merely take up residence in bone marrow niches alongside their more elderly counterparts...
Title: Re: QotW - 12.09.30 - Would self bone marrow transplants reverse aging?
Post by: JamesHarvisonStuart on 16/10/2012 12:12:16
Sorry for the slight change in subject: You quote Anne Corcoran of the Babraham Institute suggesting amongst other immune system boosters "a healthy diet high in antioxidants". From reading such works as Ben Goldacre's 'Bad Science', I had formed the impression that there was little if any basis for claiming health benefits for anti-oxidant rich foods and supplements. Has this now changed, or did I miss the point in the first place?
Title: None
Post by: Philip on 30/04/2015 14:04:45
If we took ethics aside, imagine the following: MAYBE your young clones could provide all the progenitor cells you need to live healthy ever after. However, the point is: we don't yet know all the pathways for tissue renewal. For instance, Neuroblasts injected to the blood stream would have possibly no effect at all in replacing ageing neurons in the brain or spinal chord.
An interesting experimental model would be to promote bone marrow transplants from youngling syngenic mice to elder ones, to evaluate if there would be an immune response improvement to a major ageing related cause of death pathogen infection.