Releasing the insulin handbrake

Posted: 11th September 2017

SVI’s Dr Kim Loh is part of a team of international researchers led by Prof Herbert Herzog from the Garvan Institute, who have found that a receptor, called Y1, suppresses the release of insulin by pancreatic islets. This discovery has the potential to boost insulin secretion and improve the effectiveness of islet transplant procedures.

Dr Loh, from SVI’s Protein Chemistry & Metabolism Unit, led the human islet studies in the study, in collaboration with SVI Director, Professor Tom Kay and Associate Professor Helen Thomas. The human islets were obtained through the Australian Islet Transplant Program, of which that SVI is part. The Program has undertaken more than 45 isolations for type 1 diabetes and and pancreatitis patients.

“We found that human islets are able to release more insulin when this receptor - the Y1 receptor - is blocked. When we undertook transplants using human islets in diabetic mice, we also found that we could correct their blood sugar levels more rapidly when they were co-administered with the Y1 receptor blocker,” said Dr Loh.

Often, patients will need two or three islet transplants before their body has enough islets to produce the amount of insulin they need. Blocking the Y1 receptor and boosting insulin production could mean fewer islet cells needed for each transplant, opening up the procedure to more people with type 1 diabetes. The need for fewer donor cells could reduce the risk of immunological complications, leading to a better outcome for transplant recipients. 

Type 1 diabetes is an autoimmune disease that develops when the body’s immune cells mistakenly destroy the insulin-producing cells contained within the pancreas; it is normally managed with daily insulin injections throughout an individual’s lifetime. Islet transplantation is a treatment for people who have unstable type 1 diabetes, especially those with recurrent or severe hypoglycemia, which happens when blood glucose levels drop dangerously low. 

“We are very grateful to the people who donate their pancreatic islets for our studies, and their families. Pancreas donation is essential for making islet transplantation therapy feasible and more accessible for type 1 diabetes patients,” said Dr Loh. “These discoveries wouldn’t happen without their generosity.”

The findings were published on Friday September 8th in the journal Nature Communications.

Learn more about the study.