Parabiosis research in which the circulatory systems of a young and old mouse are connected has led to a cataloging of differences in circulating factors in old versus young blood. Researchers have demonstrated that resetting the levels of GDF-11 in old mice produces beneficial effects, probably through reactivation of stem cell populations and thus increased repair and maintenance of tissues. Other important signaling molecules will no doubt be discovered and manipulated in the years ahead.
Outside of the ability to energize native stem cell populations, there may not be too much more here, however. Even that has to be cautiously approached because of the risk of spurring cancer - the consensus is that the fading of stem cell activity reduces cancer risk, but at the cost of a slow decline in tissue and organ function. Much of the rest of the aging process is driven by things like accumulation of metabolic waste products that the body breaks down only slowly, if at all, however, things that are not much affected by stem cell activity. So it may well be that parabiosis research and the resulting manipulation of factors in the blood is one of the first stepping stones to a future of stem cell therapies that discards transplantation in favor of controlling a patient's own stem cells, but nothing more.
The proposal quoted below is one logical next step following on from present research indicating factors in old blood can be manipulated for benefit. The author suggests a sophisticated form of periodic blood filtration and augmentation, in which the level of some factors is reduced and others raised. Whether this particular technology comes to pass or not depends strongly on the details of the ongoing cataloging and manipulation of important signaling molecules in animal studies, of course.
This hypothesis proposes a new prospective approach to slow the aging process in older humans. The hypothesis could lead to developing new treatments for age-related illnesses and help humans to live longer. Scientists have presented evidence that systemic aging is influenced by peculiar molecules in the blood. Researchers discovered elevated titer of aging-related molecules (ARMs) in blood, which trigger cascade of aging process in mice; they also indicated that the process can be reduced or even reversed. By inhibiting the production of ARMs, they could reduce age-related cognitive and physical declines and lead to slower rates of aging.
A prospective "antiaging blood filtration column" (AABFC) is a nanotechnological device that would fulfill the central role in this approach. An AABFC would set a near-youth homeostatic titer of ARMs in the blood. In this regard, the AABFC immobilizes ARMs from the blood while blood passes through the column. The AABFC harbors antibodies against ARMs. ARM antibodies would be conjugated irreversibly to ARMs on contact surfaces of the reaction platforms inside the AABFC till near-youth homeostasis is attained. The treatment is performed with the aid of a blood-circulating pump. Similar to a renal dialysis machine, blood would circulate from the body to the AABFC and from there back to the body in a closed circuit until ARMs were sufficiently depleted from the blood.
The optimal application criteria, such as human age for implementation, frequency of treatments, dosage, ideal homeostasis, and similar concerns, should be revealed by appropriate investigations. If AABFC technology undergoes practical evaluations and gains approval, it would hold future promises such as: 1) prolonged lifespans; 2) slowed age-related illnesses in the elderly; 3) reduced health expenses; 4) reduced cosmetic surgeries performed on the elderly; 5) healthier astronauts in extended outer space journeys; 6) reduced financial burden of advanced care for the elderly imposed upon both government and society; and 7) rejuvenating effects in healthy, non-aged individuals.