动物实验,阿尔茨海默氏病 z-bo 2020-08-19 524

　　Some patients with Alzheimer's disease will participate in a special experiment in California: They come from adolescents to study whether this method can improve cognitive performance and reverse the condition. The blood transfused can cause damage.

　　Scientists have reason to be confident in this research. Animal studies have shown that blood transfusion from young mice not only improves the cognitive ability and health of multiple organs in old mice, but they also look younger. If the same results can be produced for humans, the market for branch industries such as cosmetics and pharmaceuticals may be very large.

　　The blood of young mice revitalizes old mice

　　In addition to the vampire legend, the earliest idea of implementing blood exchange can be traced back to Cornell Ithaca nutritionist Clive in the 1950s. I will. McKay (McKay) is a method of connecting the circulatory system of old mice, which is called "changing time and symbiosis" in immunology. He found that the old cartilage had recovered earlier than expected.

　　However, it was only recently that people had a better understanding of the mechanism behind the experiment.

　　Stanford University's Thomas Rand (Thomasand) research team found in 2005 that the blood of young mice can restore the liver and skeletal muscle stem cells of young mice to a young state. Like little mice, big mice can also repair injured muscles. But things seem to have two aspects: the younger mice that took blood from the older mice also showed signs of premature aging, and in some cases the injured muscles did not heal as fast as expected.

　　Several other experiments showed similar results. In 2012, a study conducted by the Harvard University Amy Weijiesite team showed that the blood of young mice can reverse the weak heart function of old mice. The researchers paired hypertrophied old mice with healthy young mice and connected their circulatory systems. After 4 weeks, the hearts of the old mice shrank to the same size as the young mice. However, in this experiment, young mice were not affected by the blood of their opponents, and there was no change in heart size. The protein GDF11 in plasma is an important element. Researchers at Harvard University denied that lower blood pressure would affect changes in older mice, and concluded that a protein called growth differentiation factor 11 (GDF11) in the plasma seemed to play an important role. The level of this protein decreases with age. They injected GDF11 into aging mice with hypertrophic myocarditis every day. After 30 days, these mice had the same degree of cardiac contraction as the previous "xenobiotic" experiments. One year later, experiments showed that the number of blood vessels and stem cells in the brain of mice injected with GDF11 every day increased, and these two factors helped to improve brain function. Another independent research team led by Tony Weiskerry of Stanford University conducted similar experiments. They injected the plasma of young mice into old mice and found that the latter had enhanced endurance and cognitive functions.

　　GDF11 levels decrease with age, whether it is mice or humans. Researchers do not know the reason for the decline in GDF11, but do know that GDF11 is involved in several mechanisms that control the development. GDF11 is also believed to reduce the effects of aging on the brain because it can activate other proteins involved in neurodevelopment and long-term memory.

　　Human experiments are about to begin

　　The next important question is whether increasing the level of GDF11 will have the same effect on humans.

　　Weiss-Corey believes that this method is feasible. His research team has tried to inject juvenile plasma into old mice. Preliminary studies have shown that human blood can also rejuvenate old mice. He said: "We have seen these amazing effects, and human blood has beneficial effects on all organs studied so far."

　　Healthow's last contact with the poor elderly will soon begin to conduct plasma human testing on young people. In early October, the Stanford University research team injected plasma donated by teenagers under the age of 30 into elderly volunteers with mild to moderate Alzheimer's disease.

　　Weiss-Corey said that because of the long-term safe blood transfusion record, this human trial is easily approved. The research team hopes that the cognitive abilities of these elderly volunteers will soon improve, but Vescoli said this is still an experimental move. He warned against trying to replace blood at home because it requires multiple steps before transfusion, such as disease screening, blood type matching, plasma separation, etc., and "of course it is not recommended to drink blood." He said: "

　　"Evaluate the cognitive function of the patient before and after the blood transfusion, and follow each patient in the next few months to see if there is a positive effect. "This effect may be temporary, but it turns out that even if only one day It is also worth pursuing this idea. "

　　But all the researchers who participated in this study. Agree that GDF11 cannot make organs young. The only factor. "The idea that there is only one factor is too optimistic," said Francisco Lofred, who conducted similar research at Harvard University. This is likely the result of a combination of multiple factors. "It seems attractive to examine adolescents’ blood with Alzheimer’s disease, but in the long run, it’s best to work hard to determine which repair factor is performing this repair... It is easier for humans. He said: "It's hard to imagine if you have to inject young blood all the time, and who can provide you with all this blood, can use it as a treatment. Could young people’s blood be an adjunct to chemotherapy? University of Rome, Italy

　　Alessandro Laviano said that this research on aging diseases is undoubtedly promising. But he is more interested in the possibility of using adolescent blood to treat chronic diseases. He said that if cancer patients can avoid muscle atrophy, their chances of survival will be greatly increased. "We are considering whether to use these important factors in the blood of young people to reduce the occurrence of muscle wasting during chemotherapy."

　　Tanla Viano also entered clinical trials for cancer patients. He also said that a more in-depth understanding of the dynamic changes of these beneficial factors in the blood is needed, such as during peak hours. 5 years or 35 years? He said: "I don't know." I also want to make a clear investigation of what happens if I overuse GDF11. Will GDF11 provide more benefits, or will it be adversely affected? Laviano is currently testing the effect of GDF11 on tumor animals to see if it can inhibit tumor growth.