糖尿病 z-bo 2020-11-16 293

　　Researchers successfully treated mice with type 1 diabetes by transplanting pancreas tissue to mice. These transplanted pancreatic tissues are grown from stem cells taken from healthy mice in rats. They successfully controlled the blood sugar levels of mice for more than one year without the assistance of any other drugs. This also means that the diabetic mice successfully received pancreatic tissue transplantation without the need for immunosuppressive drugs.

　　Research shows that this technology is expected to be used in the treatment of human diseases, and it is very promising to increase the success rate of various organ transplants.

　　Type I diabetes is caused by the immune system destroying certain cells in the pancreas (such as the islet cells that produce insulin). Without insulin, it will be difficult for the human body to transport the glucose in the blood to the tissue cells, which is why people with diabetes need to inject insulin regularly and monitor blood sugar levels to ensure a stable body condition. However, scientists have been looking for more long-lasting methods than insulin injections to solve the problems caused by diabetes.

　　In the 1970s, scientists discovered some pancreatic islet cell populations successfully transplanted in laboratory mice, which gave people the hope of pancreatic tissue transplantation in diabetic patients. However, although some progress made in recent years has allowed transplanted cells to live longer, the process of achieving clinical application is very long and tortuous.

　　So far, these transplant operations still require lifelong anti-rejection drugs. However, if the body can treat the foreign islet cells as its own cells, it can avoid the use of these anti-rejection drugs. Now, scientists have found a way to conceal the alien characteristics of these foreign tissues to achieve this goal.

　　According to a report in the journal Nature, a group of scientists from Stanford University and the University of Tokyo found that replacing the pancreas with pluripotent stem cells may be able to successfully achieve transplantation without the need for lifelong immunosuppressive drugs.

　　In the process of transplantation, after the tissue is transplanted into a new individual, some "tags" on the tissue will allow the body to recognize that these tissues are from other individuals, leading to an immune response. Pluripotent stem cells are cells that have not yet clearly differentiated. Some "tags" of these cells can be removed by cell engineering methods, so that after these cells grow into other tissues of the body, they lack those that may expose their foreign identity. Sign. Therefore, tissue cultured with pluripotent stem cells becomes an ideal transplant material.

　　In order to convert these pluripotent stem cells into pancreatic tissue, these scientists implanted stem cells from mice into rat embryos that lacked pancreas. As rats grow, they have to use the cells of these mice to generate new pancreas. Because when these stem cells were injected into the rats, the rats had not yet formed their own immune system, so their bodies retained the stem cells of these mice as their own tissues.

　　When the rat’s own pancreatic tissue grows, the original islet cells will be transplanted into the kidneys of diabetic mice. This process will transplant hundreds of thousands of cells. After a year of transplantation, the pancreatic cells grown in the rat successfully controlled the blood sugar level of the recipient (ie, the mouse). At the same time, scientists found that transplantation of only 100 islet cells can be successful.

　　Scientist Nakauchi said: "In addition, the transplanted animals only need to take immunosuppressive drugs five days after the transplant operation, instead of continuous immunosuppression like those that have received mismatched organ transplants."

　　Finding a way to reduce the risk of rejection is of great benefit to any organ transplant, so this is a huge improvement. In the current scarcity of organ donors, people urgently need a tissue that can grow into transplantable organs to meet the demand for organs. This is also a breakthrough in the technology of culturing and transplanting tissues in the laboratory. It is not only expected to bring good news to the majority of diabetic patients, but may also find use in other occasions where tissue or organ transplantation is needed.