Increased methylation of interleukin 6 gene is associated with obesity in Korean women.
Obesity is the fifth leading risk for death globally, and a significant challenge to global health. It is a common, complex, non-malignant disease and develops due to interactions between the genes and the environment. DNA methylation can act as a downstream effector of environmental signals; analysis of this process therefore holds substantial promise for identifying mechanisms through which genetic and environmental factors jointly contribute to disease risk. To assess the effects of excessive weight and obesity on gene-specific methylation levels of promoter regions, we determined the methylation status of four genes involved in inflammation and oxidative stress [interleukin 6 (IL6), tumor necrosis factor α (TNFα), mitochondrial transcription factor A (TFAM), and glucose transport 4 (GLUT4)] in blood cell-derived DNA from healthy women volunteers with a range of body mass indices (BMIs) by methylation-specific PCR. Interestingly, the samples from obese individuals (BMI ≥ 30 kg/m(2)) showed significantly increased hypermethylation for IL6 gene compared to normal weight (BMI < 23 kg/m(2)) and overweight samples (23 kg/m(2) ≤ BMI < 30 kg/m(2)) (P = 0.034 and P = 0.026). However, there was no statistically significant difference in promoter methylation of the other 3 genes between each group. These findings suggest that aberrant DNA methylation of IL6 gene promoter may play an important role in the etiology and pathogenesis of obesity and IL6 methylation could be used as molecular biomarker for obesity risk assessment. Further studies are required to elucidate the potential mechanisms underlying this relationship.
College of Nursing, School of Medicine, Kyungpook National University, Daegu 702-422, Korea.
Yeon Kyung
YK
Na
College of Nursing, School of Medicine, Kyungpook National University, Daegu 702-422, Korea.
Hae Sook
HS
Hong
Department of Preventive Medicine, School of Medicine, Kyungpook National University, Daegu 702-422, Korea.
Won Kee
WK
Lee
Department of Anatomy and BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu 702-422, Korea.
Young Hun
YH
Kim
Department of Anatomy and BK21 Plus KNU Biomedical Convergence Program, School of Medicine, Kyungpook National University, Daegu 702-422, Korea.
Dong Sun
DS
Kim
D000293:Adolescent; D000328:Adult; D044466:Asian People / Q000235:genetics*; D019175:DNA Methylation; D005260:Female; D056726:Genetic Association Studies; D006801:Humans; D015850:Interleukin-6 / Q000097:blood / Q000235:genetics*; D008875:Middle Aged; D009765:Obesity / Q000235:genetics*; D011401:Promoter Regions, Genetic; D056910:Republic of Korea; D055815:Young Adult
C508600:IL6 protein, human; D015850:Interleukin-6
BMI; GLUT4; IL6; MSP; Methylation; TFAM; TNFα