Thanks to a breakthrough in stem cell research, scientists are tantalizingly close to finally achieving an effective treatment for type 1 diabetes. Using human embryonic stem cells, Harvard researchers have developed a technique that allows them to produce insulin-producing cells in quantities sufficient for both drug discovery and transplantation into diabetes sufferers. Due to the success of pre-clinical non-human animal trials, the researchers are hopeful that human trials could be initiated in just a few years. The work has been published in Cell.
Diabetes is a metabolic disease which results in higher than normal blood sugar levels for prolonged periods. There are two main types of diabetes: type 1 and type 2. The former, which accounts for around 10% of diabetes cases, is an autoimmune condition in which the body attacks insulin-producing beta cells in the pancreas. Because insulin is not produced, the body is unable to regulate blood glucose levels.
While sufferers can maintain relatively normal blood glucose levels with daily insulin injections, it is often not precise enough to properly control metabolism, which can lead to serious complications such as blindness. Researchers have therefore been exploring new ways to tackle the disease in order to overcome these problems. Given the vast therapeutic potential of stem cells, scientists wondered whether it might be possible to replace the beta cells in diabetic patients as a novel form of therapy.
Although scientists previously managed to produce insulin-producing cells from human stem cells, they lacked many of the functional characteristics of pancreatic beta cells. However, the new technique pioneered by Harvard scientists allowed the team to produce hundreds of millions of mature beta cells from stem cells. These are remarkably similar to adult beta cells in that they respond to glucose and secrete insulin in quantities comparable to normal functioning cells.
They tested out the cells both in dishes and in mice and found that they responded appropriately to challenges with glucose. Furthermore, they relieved diabetic mice of hyperglycemia after transplantation. They have been monitoring the transplanted mice for several months now, and so far the cells have resisted immune attack and are still producing insulin. The researchers are currently continuing tests in both rodents and non-human primates, but they hope to move towards human trials within a few years. “We are now just one pre-clinical step away from the finish line,” lead researcher Doug Melton said in a news release.
Since the immune system destroys beta cells in individuals with diabetes, the team needs to develop a way to prevent this from happening for the therapy to be viable. Although they haven’t got this far yet, they are currently in the process of producing an implantation device that would provide the cells with some protection.