Lucky Dogs Get Shot at Diabetes Cure
To test the therapy, the researchers needed dogs with diabetes. However, the types of diabetes that occur naturally in dogs aren't the same as type 1 diabetes. So, the researchers induced diabetes in a group of beagle puppies between 6 and 12 months old. The dogs were then given daily insulin injections.
The gene therapy involved a single session of numerous injections in the dog's rear legs. The needles used are like those used in human cosmetic procedures.
The dogs quickly got better and maintained normal blood sugar levels without insulin. The researchers continued to measure blood sugar control and the animals' health for more than four years. The dogs stayed healthy, and seem to have no long-term problems from the gene therapy.
Lead researcher Fatima Bosch, director of the Center of Animal Biotechnology and Gene Therapy at the Universitat Autonoma de Barcelona in Spain, said the next step in their research is to test the gene therapy on dogs with naturally occurring diabetes. The dogs will also be pets, so their living conditions and glucose levels will be varied, more closely mimicking what a person with type 1 diabetes would encounter.
Dr. Camillo Ricordi, director of the Diabetes Research Institute and the cell transplant center at the University of Miami, called the new research "an important study, and a remarkable initial finding. But, this is not a type 1 model of diabetes. This is a model where you induce diabetes chemically and you may have residual [beta] cell function."
Ricordi explained that because it's not naturally occurring type 1 diabetes, there's no worry of the immune system destroying the insulin-releasing cells in the muscle. But, in a person with type 1 diabetes, the immune system could still attack and destroy these new cells.
Dr. Massimo Trucco, chief of the division of immunogenics at Children's Hospital of Pittsburgh, said the issue of autoimmunity is an important one. But, of greater concern to him is that while this therapy worked in very controlled conditions -- the dogs' diets and exercise sessions were controlled -- in real-life conditions, this therapy might not work as well.