In October 2014, Stanford University is going to conduct an unprecedented clinical trial. This clinical trial sounds very alternative, or quirky. The subjects of the experiment are elderly people suffering from Alzheimer’s disease, commonly known as dementia. The experiment was conducted by drawing blood from young people, extracting the plasma and transfusing it to these elderly people. The purpose of the experiment was to see if the cognitive impairment of these elderly people could be improved or even partially recovered by feeding them the blood of young people.
This sounds a lot like a blood-sucking story from a spooky movie. In fact, Dr. Tony Wyss-Coray, the trial’s facilitator, says that every time he gives a talk about the program, it draws shouts of “vampire” from the audience.
But in reality, this incredible clinical trial is not a movie, but a serious research project that is actually underway. This seemingly absurd experiment is backed by solid scientific evidence. Previous animal experiments at Stanford and Harvard Universities have shown that by feeding blood to younger mice, some of the older mice have improved cognitive abilities and the health of several organs. Even the older mice fed with younger blood looked a little younger. If this “rejuvenation” phenomenon can be reproduced in human trials, it is expected to cause a huge revolution in the pharmaceutical and cosmetic industry.
The rejuvenation of mice
Immortality has always been an endless pursuit for human beings, and rejuvenation is an unreal legend. But the idea of rejuvenating older animals by replacing them with fresh blood is not a recent one. In February 1956, Dr. MaCay published an article in the Bulletin of the New York Academy of Medicine entitled “Experimental Life Extension”. He anastomosed the blood vessels of 90- and 300-day-old rats of the same blood type from the same family, and the two rats shared circulation, a state called heterozygous congenital. The results showed that the articular cartilage of the older rats quickly became much younger and appeared to reverse aging.
But there has been no answer as to why this happened. It is only in recent years that a number of studies have begun to unravel the mechanisms behind this phenomenon.
In 2005, a group led by Professor Thomas Rando of the Department of Neurology at Stanford University School of Medicine published their findings in the prestigious scientific journal Nature, which stunned the entire regenerative and geriatrics community. They matched young and old rats together through a vascular anastomosis. After a period of time, the linked rats began to share a circulatory system, becoming a model of heterozygosity, and after five weeks, they were surprised to find that the stem cells in the liver and skeletal muscle of the older rats returned to a more youthful state that was incompatible with their age. The older rats even showed almost the same ability to repair muscle damage as the young pups. To exaggerate, it was the older rats that partially rejuvenated.
However, unfortunately, the young mice that were forcibly attached received the blood circulation of the older rats and experienced premature aging. These young rats showed an age-appropriate diminution of muscle repair capacity. It seems that the young rats and the aged rats showed a surprising age-neutralization.
Does seeing this remind you of vampires in the movies?
Of course, scientific studies can’t be a family story, and have to be repeated by other independent teams to be reproduced. After this article was published, it attracted a lot of attention from the regenerative medicine and geriatrics community. Many teams started working on similar experiments.
The secret of longevity
In 2013, Professor Amy Wagers’ team at Harvard University did a similar experiment. They connected a two-month-old mouse and a 23-month-old mouse with cardiomegaly through a vascular anastomosis to start sharing blood circulation. Surprisingly, just four weeks after the connection, the hypertrophy in the older mouse improved rapidly and the heart muscle cells returned to almost the same size as the younger mouse. To add to the joy, the young mouse was not negatively affected in any way and grew healthy. The paper was published in the topmost biological journal Cell.
But is it possible that the heart muscle recovered because the hypertension in the older mice was relieved after the blood vessels were connected, thus reducing the stress on the heart muscle? After a series of experiments that ruled out the possibility that the heart muscle recovered because of the altered blood pressure, they found the answer in the mice’s blood. A protein in the blood, called growth differentiation factor 11 (GDF11), is thought to play a key role. This factor declines with age. To test this hypothesis, they gave aged mice with cardiomegaly a continuous injection of this protein for 30 days. At the same time, another group of mice of the same age with the same cardiac hypertrophy was used as a control, and only saline was injected. As a result, at the end of the experiment, almost all of the aged mice injected with GDF11 showed myocardial recovery that far exceeded that of the control group, with a significant reduction in heart size. Dissection revealed that cardiomyocytes were also significantly reduced in size.
Both experiments confirm that animal organ aging has a surprisingly scalable nature. However, it is clear that aging is an immensely complex physiological process that cannot be a function of this one protein alone. The aging of other organs may be manipulated by other factors. Anti-aging may require not only inhibiting aging factors, but also increasing the factors that maintain youth, one without the other.
A year later, the Harvard team published another progress paper in the prestigious journal Nature Medicine. They found that after a period of continuous injection of GDF11 into aged mice, the older mice showed an increase in the number of neovascularization and stem cells in their brains, indicating rejuvenation and suggesting improved brain function.
During the same period, Tony Wyss-Coray’s team at Stanford University in California did a similar experiment. After 5 weeks, they found that the brains of the older mice that received the younger blood showed significant changes, although not as pronounced as those achieved in the allogeneic symbiosis experiment, but the fresh blood partially reversed the aging brain, showing significant rejuvenation at the molecular, structural, functional and cognitive levels. . Older mice showed improvements in learning ability, environmental adaptability, and memory, as well as even partial improvements in physical strength. This study was published in the February 2014 issue of Nature Medicine.
Both mice and humans have now found that GDF11 in the blood slowly declines with age. Exactly why it declines is not yet known. But what is known is that this protein is associated with several physiological signaling pathways that control growth. It has also been found that this protein can control and influence brain aging and long-term memory through the control of additional proteins.
Looking forward to
The publication of this inspiring and unbelievable series of animal studies naturally leads to the next step: Can these animal results be reproduced in humans? Could the increased levels of GDF11 protein result in the rejuvenation observed in the mouse experiments?
Stanford’s Wyss-Coray is confident. That’s because they recently conducted experiments in which they took blood from young people, extracted the plasma, and injected it into older mice. Preliminary results found that the blood from young humans had the same effect on the mice. And this young man’s plasma affected almost all the organs of the older mice.
The experiment had made it this far and could no longer be stopped here.
Human experimentation was imperative. Normally, experiments with human protein injections in the United States require strict FDA regulation and approval, which is time-consuming and expensive. But blood or plasma transfusions are too common and too common a treatment that must be done every day in the clinic, and the safety of blood transfusions has been proven for more than 100 years, so this experiment did not need FDA approval to begin.
Interestingly, once this experiment was disclosed, the experiment host, Dr. Wyss-Coray, warned the public in the media not to change blood at home on their own. This is because blood transfusions are required to be sampled and matched at a hospital to screen for disease, and this experiment only transfuses plasma, not whole blood. In addition, he also warned that it is useless to drink blood like in the movie, although no one has done this experiment, but the blood drunk through the gastrointestinal processing, the protein will be digested and decomposed, is not useful.
The experiment called for young volunteers under the age of 30, and after drawing their blood, the blood cells were removed, and then the remaining plasma was injected into elderly patients with Alzheimer’s disease who were matched with the same blood type. The Stanford team is confident because of the strong data from the animal studies, and Dr. Wyss-Coray is optimistic about seeing rapid improvement in these patients’ symptoms. Of course, this is still early in the trial phase, and there is no guarantee that the expected improvements will occur; careful short-term and long-term evaluation and follow-up will be required. The improvement in patients’ symptoms may be short-lived and temporary, but even so, it can be considered encouraging. Because it means that this is the right direction, and if we continue along this line of research, we may actually see the day when rejuvenation is not just a myth, but a reality that can be achieved.