Potential Diabetes Cure Grown in GMO Lettuce

Author:  Doshi Ojus
Date:  August 2007

Last week, scientists at the University of Central Florida announced and demonstrated a possible way to cure Type-1 diabetes, an auto-immune disease which destroys insulin producing cells in the pancreas.

The researchers, led by Professor Henry Daniell, fed diabetic mice capsules of insulin derived from genetically engineered lettuce. By the end of the study, they observed that all mice recovered normal blood and urine glucose levels. If human clinical trials are successful, the potential medication could provide lasting relief for millions of Type-1 diabetes sufferers worldwide. The findings were published in the July issue of Plant Biotechnology Journal.

"Diabetes is a big health and financial burden in the United States and in the rest of the world," Daniell said. "This study would facilitate a dramatic change because so far there is no medicine that will cure insulin-dependent diabetes."

The researchers employed several clever methods to deliver insulin to the pancreas, the organ which normally produces insulin. First, they modified DNA in the chloroplasts of lettuce cells to produce insulin. Since chloroplasts, which are unique to plant cells, contain hundreds of copies of the same DNA, this method effectively amplified the amount of insulin produced, and, at the same time, packaged the insulin inside a protective casing.

"When we orally deliver it, the insulin is inside the chloroplast, and the plant cell wall protects the insulin from the stomach acids," Daniell explained. "Bacteria in the gut then act on these cells and release insulin."

In addition, the researchers attached a non-toxic version of cholera to the plant derived insulin. Normally, cholera uses a protein with a specific receptor to gain access into the circulatory system. By coupling that protein with insulin, the researchers increased the uptake of non-native insulin into the bloodstream.

At the end of the 12-week study, their final measurements indicated that the pancreatic islets, which house insulin producing beta-cells, were destroyed in untreated mice and preserved in the treated group. The delivery of insulin both restored glucose levels and prevented the destruction of beta-cells by the immune system.

"We are very specifically showing that this is a cure for diabetes," said Daniell, whose lab is now entering the human clinical trial phase.

Written by Ojus Doshi