Transmission of a protein could cause symptoms of type 2 diabetes

Symptoms of type 2 diabetes can be induced following the transmission of a misfolded type of protein, according to new research.
US researchers have reported a type of pancreatic protein is capable of inducing lost beta cell function and elevated blood glucose levels, both symptoms of type 2 diabetes.
The study also found some similarities to a form of diseases known as prion diseases, which include Bovine Spongiform Encephalopathy (mad cow disease) and Creutzfeldt-Jakob disease.
“Until now, this concept has not been considered,” said study author Claudio Soto, McGovern Medical School at The University of Texas Health Science Center at Houston. Soto stressed, however, that there is no strong evidence to suggest type 2 diabetes is an infectious condition.
Over 90 per cent of people with type 2 diabetes have abnormal protein deposits in their insulin-producing pancreatic islets. These deposits mainly consist of aggregates of a particular protein: islet amyloid polypeptide (IAPP).
While type 2 diabetes is linked to genetic, environmental and lifestyle risk factors, its cause is not wholly understood. Similarly, the precise role of IAPP in type 2 diabetes is unclear.
The researchers hypothesise that IAPP kills pancreatic islets in a similar way to diseases caused by other misfolded protein aggregates, such as Alzheimer’s disease and Parkinson’s. When a protein becomes misfolded its structure changes which prevents it from functioning as expected.
Soto and colleagues found that injecting small amounts of misfolded IAPP aggregated the formation of protein deposits in the pancreases of mice. Within weeks these mice developed type 2 diabetes symptoms.
They believe small amounts of misfolded IAPP could induce similar levels of deposits of protein aggregates in pancreatic islets isolated from healthy human donors.
However, the research does not show that type 2 diabetes can be transmitted between individuals. Soto said: “Considering the experimental nature of the models and conditions utilized in this study, the results should not be extrapolated to conclude that type 2 diabetes is a transmissible disease in humans without additional studies.”
The findings appear in The Journal of Experimental Medicine.