Potential new approach to treating diabetes

Manipulation of a cytokine that regulates beta cell stress reverses high blood sugar providing a potential new approach to treating diabetes.

Professor Mike McGuckin and his team at the Mater Research Institute at the University of Queensland have found that a cytokine, interleukin 22 (IL-22), produced by immune cells relieves stress in the insulin-producing beta cells of the pancreas.

The main problem for people with type 2 diabetes is the inability to produce enough insulin to control blood sugar. This results in hyperglycaemia or high blood sugar levels, which are associated with obesity.

Insulin synthesis in beta cells begins in the intracellular endoplasmic reticulum (ER). Preproinsulin is folded and cleaved to form mature insulin, which is packaged into granules and passed through the cell to be secreted.

Beta cells are believed to become dysfunctional and secrete insufficient functional insulin because of oxidative and ER stress.

“The research shows that IL-22 can restore the control of blood sugar levels by restoring appropriate insulin production and also correcting sensitivity to insulin in responsive tissues,” he said.

The researchers found that endogenous and exogenous IL-22 regulate oxidative stress pathways, which in turn suppressed oxidative and ER stress in mouse and human beta cells.

“This finding is significant because it means diabetics could potentially replace insulin injections with less frequent injections of IL-22.”

More work needs to be done before clinical trials in diabetes patients could begin.

“Because it is a biological therapy, IL-22 may have side effects that we have not seen so far in the research, limiting its appropriateness as a treatment. However, it also opens up a new pathway for treating diabetes based around the way IL-22 works.”

The researchers are working with partners in the pharmaceutical industry to develop prototype therapies with a view to moving towards clinical trials in patients with diabetes.

The paper has been published in Nature Medicine.