A study by Lund University researchers has examined the chicken vs egg dilemma when it comes to investigating what comes first, diabetes or the epigenetic changes that are a major part of diabetes? This study has for the first time correlated epigenetic changes as a major cause of diabetes. “This shows that the risk of developing type 2 diabetes is not only genetic, but also epigenetic,” said Charlotte Ling, who led the study, published in the PLOS journal.
Epigenetics is defined by the changes to gene expression caused through outside influences such as the environment or food ingested, and not directly through changes in the DNA sequence. Changes caused by epigenetics are reversible.
Ling and her colleagues analysed insulin- producing cells of both healthy individuals and patients with type 2 diabetes. The investigation revealed epigenetic changes in approximately 800 genes in the individuals afflicted with type 2 diabetes. Over 100 of the genes also had an altered expression contributing to reduced insulin production. Reduced insulin production is one of the underlying causes of type 2 diabetes.
“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 these changes could contribute to the development of the disease,” said Charlotte Ling. “Unlike genes that can’t be changed, epigenetic changes are reversible,” added Tasnim Dayeh, first author of the study.
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. Genome-Wide DNA Methylation Analysis of Human Pancreatic Islets from Type 2 Diabetic and Non-Diabetic Donors Identifies Candidate Genes That Influence Insulin Secretion. PLoS Genetics, 2014; 10 (3): e1004160 DOI: 10.1371/journal.pgen.1004160