Drs. Prud'homme and Wang warn that many treatments that work in mice are not always equally effective in humans.
Image credit: St. Michael's Hospital
In 2011, the team published a study demonstrating how injections of the amino acid gamma-aminobutryic acid (GABA) not only prevented mice from getting type 1 diabetes, but also reversed the disease in mice that already had the disease.
Scientists have known for decades that GABA plays an important role in the brain as a neurotransmitter, where it facilitates the communication between nerve cells. However, its role in the pancreas - where it is produced - was not known until the 2011 paper, authored by Drs. Gerald Prud'homme and Qinghua Wang.
In their latest research, the team trialled the therapy in mice that had been injected with human pancreatic cells. In the December issue of the journal Diabetes, they report that GABA has the same diabetes-reversing effect on the human cells that it did in the mice from the previous study.
The researchers say that GABA also "vastly improved" the survival rate of the pancreatic cells during the period between the cells being harvested from the organ and being transplanted into the mice.
Identifying this life-extending property of GABA is an exciting finding, because usually about 70% of pancreatic cells die during this period. Drs. Prud'homme and Wang think that this finding could form the basis of further research looking specifically at pancreatic transplants.
Although the potential for this naturally produced chemical to reverse type 1 diabetes sounds promising, the process of testing the therapy in human clinical trials could take several years. The scientists also warn that many treatments that work in mice are not always equally effective in humans.
Other successes in reversing diabetes in mouse models
Last month, Medical News Today looked at a study conducted by researchers from Harvard University in Cambridge, MA, which purported to be a breakthrough in using stem cells as an effective therapy for reversing type 1 diabetes in mice.
Fast facts about beta cells and type 1 diabetes
- Insulin is a hormone produced in the pancreas by beta cells, which is needed to move glucose into cells
- In people with type 1 diabetes, the body mistakenly attacks the insulin-producing beta cells
- Without insulin from the beta cells, glucose instead builds up in the bloodstream, where it cannot be turned into energy.
The Harvard scientists successfully created billions of insulin-producing pancreatic beta cells from embryonic stem cells. Two weeks after the transplantation of these beta cells into a diabetic mouse, the mouse was free of the disease.
However, for this treatment to work in humans with type 1 diabetes, another component would have to be added to the process in order to prevent the human immune system from attacking the beta cells upon transplantation.
Scientists from the University of Cincinnati also reported their own reversal of type 1 diabetes in a mouse model back in June. In this study, the researchers targeted a receptor called TLR4, which some studies have suggested may be defective in cases of diabetes.
The team used an agonistic monoclonal antibody to boost TLR4 activity in mice with type 1 diabetes, and they reported that the disease was reversed in a high percentage of the mice.
Boosted activity of the TLR4 receptors caused improved preservation of the pancreatic beta cells that produce insulin, say the researchers, which shielded them from the autoimmune attack characteristic of type 1 diabetes.