The Prospect of Filtering Harmful Factors from Old Blood
The Life Extension Advocacy Foundation volunteers here interview Irina and Michael Conboy, two of the more influential scientists involved in parabiosis research. When the circulatory systems of an old mouse and a young mouse are connected, the older partner shows some reversal of measures of degenerative aging, while the younger partner shows some acceleration of similar measures of degenerative aging. The Conboys have of late produced evidence to show that this is based on the presence of harmful factors in old blood, where parabiosis dilutes harmful factors in the old mouse but also passes them over to the young mouse. There is similar evidence for beneficial factors in young blood passing in the opposite direction, however.
All of this data raises the possibility of somehow filtering out the harmful factors if they can be reliably identified. While numerous forms of blood filtration equipment exist today, it seems unlikely to me that being hooked up to a suitably adapted variant for a short time would provide lasting benefits - though it could certainly be used in studies to settle debates over the degree to which specific factors are involved or important. Harmful factors are, after all, generated on an ongoing basis by cells that are damaged or are reacting to the damage of aging. To produce useful results, filtering would have to be permanently in place, such as via an implant of some sort, or enhancement to the kidneys, or pharmaceuticals that inhibit harmful factors, and none of these options seem likely to appear immediately - all would require significant development. Even with that development, such an approach is not actually addressing the causes of the issue, but rather tries to patch over just a thin portion of it.
For the sake of those new to the topic, what is it in young blood and aged blood that affects aging?
Numerous changes in the levels of proteins that together regulate cell and tissue metabolism throughout the body. We wondered why almost every tissue and organ in the body age together and at a similar rate, and from the parabiosis and blood exchange work now think that young blood has several positive factors, and old blood accumulates several negative, "pro-aging" factors. We have published on improved liver regeneration, reduced fibrosis and adiposity by transfusion of old mice with young blood, but these are genetically matched animals, and in people, we do not have our own identical but much younger twins.
How do you propose to balance the cocktail of factors in aged blood to promote a youthful tissue environment?
We are working on the NextGen blood apheresis devices to accomplish this. We are collaborating with Dr. Dobri Kiprov, who is a practicing blood apheresis physician with 35 years of experience, and he is interested in repositioning this treatment for alleviating age-related illnesses.
Do you think a small molecule approach is a viable and, more importantly, a logistically practical approach to calibrate all these factors compared to filtering aged blood?
Yes, it is a very feasible alternative to the NextGen apheresis that we are working and publishing on.
Even if we can "scrub" aged blood clean, is it likely to have a long-lasting effect, or would the factors reach pro-aging levels fairly quickly?
That needs to be established experimentally, but due to the many feedback loops at the levels of proteins, genes and epigenetics, the acquired youthful state might persist.
Ultimately, could a wearable or an implanted device that constantly filters the blood be the solution to these quickly accumulating factors?
Maybe, but the first step of a day at a NextGen apheresis clinic once every few months might be more realistic.
What do you think it will take for the government to fully support the push to develop rejuvenation biotechnology?
Clear understanding of the current progress and separating the real science from snake oil is very important for guiding funding toward realistic clinical translation and away from the myth and hype.