By Steven Chessler, MD, PhD – Associate Professor of Medicine (Endocrinology) at UCI
Dr. Steven Chessler’s lab is focused on researching insulin producing beta islet cells.
News has recently hit the wires regarding Johnson & Johnson and San Diego-based Viacyte combining forces to develop a new, promising therapy for diabetes. In the press, the new, stem cell-based treatment has been described as a “cure.” In truth, referring to this as a potential “cure” is a stretch. The goal is to use stem cells to replace lost or damaged pancreatic islet beta cells. A cure would reverse the disease process, preventing beta cell destruction and allowing regeneration. Nevertheless, the ability to treat diabetes with functioning beta cells would be a tremendous advance.
The exquisite control pancreatic islets maintain over blood sugar in large part derives in from the ability of the islet beta cells to react quickly to changes in blood glucose while also processing and responding to a complex array of incoming signals. These signals originate in the brain, gut and other tissues. Replacement of lost islets or of just beta cells has therefore been a focus of much diabetes research. Prior enthusiasm surrounding islet transplantation has ebbed in the face of significant challenges, notably ensuring long-term survival of the transplanted islets and being able to procure sufficient islets to treat more than just a few patients.
Large-scale production of beta cells from stem cells would eliminate the issue of adequate supply that limits use of donor-derived islets. A number of research groups have recently reported advances in developing the necessary biological recipes for converting stem cells into functioning beta cells. BetaLogics, part of the pharmaceutical giant Johnson & Johnson, was one of these research groups. Viacyte has also developed a method for converting stem cells to beta cells. In addition, it has developed technologies that enable delivery of the cells in a protective capsule that is implanted under the skin. Viacyte’s therapy is the first to have reached early-phase clinical trials. Viacyte’s merger with BetaLogics was announced a few weeks ago. Combining these two leaders in stem cell-derived diabetes therapies, it is hoped, will accelerate the development of these therapies.
Significant challenges remain, including establishing safety, proving the long-term viability of the implanted cells, and uncertainty regarding how well beta cells acting alone—rather than within islets can control blood sugars. Even if the current clinical testing of the Viacyte therapy goes well, it is likely that stem cell-based therapies for type 1 and type 2 diabetes are still years away.
Ongoing research by UCI diabetes researchers will contribute to the development of these novel therapies, whether through advancing stem cell technology or gaining new knowledge of the processes that lead to beta cell loss and failure in types 1 and 2 diabetes.
One of the projects in my laboratory, for example, is leading to the development of new agents that may help protect transplanted beta cells and, by tricking them into behaving as they would in a natural islet, increase their ability to secrete insulin. These agents could, we think, direct stem cell-derived beta cells to function more like fully mature beta cells, allowing individuals with diabetes to regain the elegant control of blood glucose lost with the onset of diabetes.