Type 1 diabetes results from the inability of the endocrine portion of the pancreas to secrete sufficient quantities of the hormone insulin. The cells that make insulin, beta cells, have been destroyed. Consequently, type 1 diabetics must inject themselves with insulin routinely in order to stay alive. Is there a better way?
A new strategy suggests that maybe pancreatic cells can be “rebooted” to produce insulin and that sure reprogramming could potentially help people with type 1 diabetes manage their blood sugar levels without the need for daily injections. This therapeutic approach is simpler and potentially safer than giving people stem cells that have been differentiated into pancreatic beta cells.
Philippe Lysy at the Cliniques Universitaires Saint Luc, which is part of the Catholic University of Louvain in Belgium, and his colleagues have reprogrammed pancreatic duct cells extracted from dead donors who were not diabetic at the time of death. The duct cells do not produce insulin, but they have a natural tendency to grow and differentiate into specific types of cells.
Lysy and his team grew the cells in the laboratory and encouraged them to become insulin-producing cells by exposing them to fatty particles. These fatty particles are absorbed into the cells after which they induce the synthesis of the MAFA transcription factor. MAFA acts as a genetic “switch” that binds to DNA and activates insulin production.
Implantation of these altered cells into diabetic mice showed that the cells were able to secrete insulin in a way that controls blood sugar levels. “The results are encouraging,” says Lysy.
Lysy’s colleague, Elisa Corritore, reported these results at this week’s annual meeting of the European Society for Pediatric Endocrinology in Barcelona, Spain. Lysy and others are preparing to submit their results for publication.
This work, if it continues to pan out, might lead to the harvesting of pancreatic ducts from deceased donors and converted in bulk into insulin-making cells. Such “off-the-shelf” cells could then be transplanted into people with type 1 diabetes to compensate for their inability to make their own insulin.
“We would hope to put the cells in a device under the skin that isolates them from the body’s immune system, so they’re not rejected as foreign,” says Lysy. He says devices like this are already being tested for their ability to house insulin-producing cells derived from stem cells.
Previous attempts to get round this problem have included embedding insulin-producing cells in a seaweed derivative prior to transplantation in order to keep them from being destroyed by the recipient’s immune system.
Lysy thinks that since insulin-producing cells originate from pancreatic tissue, they have an inherently lower risk of becoming cancerous after the transplant. This has always been a worry associated with tissues produced from embryonic stem cells, since these have the capability to form tumors if any are left in their original state in the transplanted tissue.
The basic premise of the work looks solid, says Juan Dominguez-Bendala, director of stem cell development for Translational Research at the University of Miami Miller School of Medicine’s Diabetes Research Institute in Florida. “However, until a peer-reviewed manuscript is published and all the details of the work become available to the scientific community, it is difficult to judge if this advance represents a meaningful leap in the state of the art.”
Lysy expects it will take between three and five years before the technique is ready to be tested in human clinical trials.