For the first time in history, Chinese scientists have successfully cured diabetes in a patient by transplanting their own stem cells. A 25-year-old woman with type 1 diabetes began producing insulin independently within three months after the procedure.
Researchers from Peking University transplanted reprogrammed stem cells, derived from the woman’s own body, into her abdominal cavity. It has now been over a year since her surgery, and she reports enjoying the ability to eat anything, including sugar, according to Nature News.
A similar study was published in April by scientists from Shanghai universities. In that case, a research team successfully transplanted insulin-secreting Langerhans islets into the liver of a 59-year-old man with type 2 diabetes. These islets were also created from the man’s own reprogrammed stem cells. He no longer requires additional insulin treatment.
Both studies are among the first to use stem cells for diabetes treatment. Worldwide, there are approximately half a billion people with diabetes. Most have type 2 diabetes, meaning their bodies either do not produce enough insulin or cannot use it effectively. In type 1 diabetes, the immune system attacks the insulin-producing cells in the pancreas.
Transplanting Langerhans islets could cure diabetes, but there are not enough organ donors for all patients in need. Additionally, patients with transplanted islets must take immunosuppressive drugs to prevent their bodies from rejecting foreign tissue.
In contrast, stem cells can be used to grow any type of tissue. Since they can be cultivated indefinitely in a laboratory, they represent a virtually unlimited source of pancreatic tissue. By using a patient’s own stem cells, scientists hope to eliminate the need for post-surgery immune suppression.
Reprogrammed Cells
In the first experiment of its kind, Peking University cell biologist Kongkui Deng and colleagues extracted stem cells from three individuals with type 1 diabetes. The researchers reverted these cells to a pluripotent state, meaning they could develop into any type of body cell.
The technique used to reprogram the cells is not new—it was originally developed by Shinya Yamanaka at Kyoto University about 20 years ago. However, Deng’s team modified the technique. Instead of using proteins that trigger gene expression, as Yamanaka did, they used small molecules, which allowed for better control over the process.
This method produced chemically induced pluripotent stem cells, which the researchers then assembled into three-dimensional clusters resembling Langerhans islets. Before transplanting them into humans, they tested the cells for safety and functionality in mice and primates.
In June of last year, the team injected approximately 1.5 million modified islet cells into the woman’s abdominal muscles in a procedure lasting less than 30 minutes. Stem cells had never been transplanted into the abdominal cavity before—normally, they are injected into the liver, where their progress is difficult to monitor. However, in the abdominal cavity, researchers could track the cells using MRI scans and even remove them if necessary.
Life Without Insulin Injections
Two and a half months after the surgery, the woman’s body was producing sufficient insulin, and she no longer needed to take insulin injections. Her insulin levels have now remained stable for over a year. A few months after the transplant, she no longer experienced dangerous fluctuations in blood sugar levels—98% of the time, her blood glucose remained within the normal range.
Scientists not involved in the study have called it a remarkable achievement and hope the technique can be used to treat many more patients. However, they caution that the results must be replicated in further studies.
Endocrinologist Jay Skyler from the University of Miami is particularly interested in whether the woman’s new insulin-producing cells will continue to function for five years—only then, he says, could she be considered fully cured.
According to Kongkui Deng, results from the other two trial participants have also been very positive. Their surgeries will reach the one-year mark this November, after which Deng plans to conduct the same procedure on 10 to 20 more patients.
Since the woman had previously received a liver transplant, she was already taking immunosuppressive drugs. Therefore, the researchers could not determine whether her reprogrammed cells reduced the risk of organ rejection.
Even if transplanted cells are not rejected by the immune system, type 1 diabetes is fundamentally an autoimmune disease. This means there is still a risk that the patient’s immune system could attack the newly transplanted cells. Deng’s team observed no such attack in the woman receiving immunosuppressive treatment, but they are working on developing immune-resistant cells for future use.
Donor Cells
Although using a patient’s own cells has many advantages, the process is complex and difficult to scale. As a result, several research teams have begun experimenting with donor-derived stem cells.
For example, in June, a research team led by Vertex Pharmaceuticals in Boston reported initial results from a study in which embryonic stem cell-derived Langerhans islets were transplanted into the livers of twelve patients with type 1 diabetes. All patients also received immunosuppressive therapy. Three months after the transplant, all participants were producing insulin in response to glucose, and some no longer needed insulin therapy.
Last year, Vertex also launched a second trial, in which donor-derived islet cells were encapsulated in a protective device designed to shield them from immune attacks. This device was implanted in one patient with type 1 diabetes who did not receive immunosuppressive therapy. Since the study is ongoing, the results have yet to be determined.
The study was published in the journal Cell.