Epigenetic changes in DNA could explain type 2 diabetes

People with type 2 diabetes have epigenetic changes in their DNA that healthy individuals do not have. This has been shown in a major survey by researchers at Lund University. The researchers also found a large number of genes that contribute to reduced insulin production because of these epigenetic changes.

“This shows that the risk of developing type 2 diabetes is not only genetic, but also epigenetic”, said Charlotte Ling, who led the study.

Epigenetic changes occur as a result of factors including environment and lifestyle, and affect the function of the genes. Charlotte Ling and her colleagues have analysed all the genes in the DNA of the insulin-producing cells in both healthy individuals and patients with type 2 diabetes. The analysis revealed epigenetic changes in 800 genes in those with type 2 diabetes. Over 100 of the genes also had altered expression that could contribute to reduced insulin production. Reduced insulin production is one of the underlying causes of type 2 diabetes.

In order to work out which is the chicken and which is the egg, i.e. whether the epigenetic changes are a consequence of the disease or if the disease is a result of the changes, the researchers also investigated whether healthy individuals had epigenetic changes caused by age, BMI and raised blood sugar levels.

“We were able to observe that a number of epigenetic changes had already taken place in healthy subjects as a result of age or high BMI, and were therefore able to conclude that the disease could come about as a result of these changes”, said Charlotte Ling.

Drugs that cause epigenetic changes have long been used in the treatment of cancer and epilepsy. The new survey changes the view of epigenetics in relation to diabetes, according to Charlotte Ling.

“It shows that epigenetics have major significance for type 2 diabetes, and that we can explain why people develop the condition using epigenetics. This also opens the way for the development of future drugs.”

The study has been published in PLOS Genetics.

Publication: Genome-wide DNA methylation analysis of human pancreatic islets from type 2 diabetic and non-diabetic donors identifies candidate genes that influence insulin secretion

Authors: Tasnim Dayeh, Petr Volkov, Sofia Salö, Elin Hall, Emma Nilsson, Anders H. Olsson, Clare L. Kirkpatrick, Claes B. Wollheim, Lena Eliasson, Tina Rönn, Karl Bacos, Charlotte Ling

Text: Charlotte Ling

Published 2014

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