Exercise can impact the expression of genes in adipose tissues that are associated with obesity and type 2 diabetes, a study found.
Note that in further experiments to assess whether the changes in methylation status and mRNA expression had an effect on adipocyte metabolism, changes in some of the affected gene sites were associated with improved lipid parameters.
Exercise can impact the expression of genes in adipose tissues that are associated with obesity and type 2 diabetes, researchers reported here.
In a small study, healthy men who followed a 6-month exercise plan had changes in DNA methylation in 18 genes associated with obesity and in 21 genes associated with type 2 diabetes, Tina Rönn, PhD, of Lund University in Malmö, Sweden, and colleagues reported at the European Association for the Study of Diabetes meeting here.
A handful of those genes also had changes in mRNA expression, potentially suggesting that exercise could impact adipocyte metabolism, Rönn said.
”The changes in genes linked to type 2 diabetes and obesity we believe are important because with epigenetics it is possible to modify by the way you live your life, with exercise and dietary and lifestyle changes,” Rönn told MedPage Today.
Metabolic disorders are influenced by genetic and environmental factors, and epigenetic factors such as DNA methylation could help explain how the environment influences the genome, ultimately impacting metabolism.
To analyze genome-wide changes in DNA methylation in human adipose tissue after a 6-month exercise intervention, Rönn and colleagues studied 23 men who were healthy but sedentary — all had a low level of physical activity at baseline.
These men then had an endurance training intervention 3 days per week.
The researchers focused on 485,577 different DNA methylation sites throughout the genome, and also looked at mRNA expression — to see how genes were being transcribed — in 21,014 genes.
All the men had significant improvements in VO2max, diastolic blood pressure, pulse rate, and HDL cholesterol, as well as significant declines in waist circumference and waist-to-hip ratio, even though body mass index (BMI) and weight didn’t change significantly.
In the genome-wide analyses, they found 17,975 CpG sites that showed changes in DNA methylation in adipose tissue after exercise. Most of the sites (90%) exhibited very small changes, so Rönn and colleagues narrowed their focus to the 1,009 sites that had much larger changes in methylation (a range of 6% to 38%).
They matched those sites with mRNA expression patterns that also changed after exercise, and found 236 sites with changes in both DNA methylation and mRNA expression. The vast majority of those (139 sites) showed increased DNA methylation and reduced mRNA expression, Rönn said.
They further checked into whether candidate genes for obesity and type 2 diabetes were among those that had such changes.
Overall, they found sites in 18 obesity gene candidates and 21 type 2 diabetes gene candidates that had changes in methylation.
For obesity, two of those genes — CPEB4 and SDCCAG8 — also had changes in mRNA expression, as did four of the genes in type 2 diabetes: HHEX, IGF2BP2, JAZF1, and TCF7L2.
In further experiments to assess whether the changes in methylation status and mRNA expression had an effect on adipocyte metabolism, Rönn said changes in some of the affected gene sites were associated with improved lipid parameters.
Thus, she concluded, changes in DNA methylation may affect changes in adipocyte metabolism.
”We have a new mechanism for why exercise is beneficial, especially for type 2 diabetes patients,” Rönn told MedPage Today. ”We knew that it is beneficial, but now we have a mechanism where we see adipose tissue [after exercise] is better at clearing lipids from the blood.”
The researchers reported no conflicts of interest.
Primary source: European Association for the Study of Diabetes
Source reference: Ronn TS, et al ”Genes associated with obesity or type 2 diabetes display altered levels of DNA methylation in human adipose tissue in response to exercise” EASD 2013; Abstract 257.
From www.medpagetoday.com
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