Circulating microRNA expression profiling in young obese Korean women.

Background/objectives: This study investigates correlations between circulating microRNAs (miRNAs) and obesity-related parameters among young women (aged 20-30 years old) in Korea.

Subjects/methods: We analyzed TaqMan low density arrays (TLDAs) of circulating miRNAs in 9 lean (body mass index [BMI] < 25 kg/m) and 15 obese (BMI > 25 kg/m) women. We also performed gene ontology (GO) analyses of the biological functions of predicted miRNA target genes, and clustered the results using the database for annotation, visualization and integrated discovery.

Results: The TLDA cards contain 754 human miRNAs; of these, the levels of 8 circulating miRNAs significantly declined (> 2-fold) in obese subjects compared with those in lean subjects, including miR-1227, miR-144-5p, miR-192, miR-320, miR-320b, miR-484, miR-324-3p, and miR-378. Among them, miR-484 and miR-378 displayed the most significant inverse correlations with BMI (miR-484, r = -0.5484, = 0.0056; miR-378, r = -0.5538, = 0.0050) and visceral fat content (miR-484, r = -0.6141, = 0.0014; miR-378, r = -0.6090, = 0.0017). GO analysis indicated that genes targeted by miR-484 and miR-378 had major roles in carbohydrate and lipid metabolism.

Conclusion: Our result showed the differentially expressed circulating miRNAs in obese subjects compared to lean subjects. Although the mechanistic study to reveal the causal role of miRNAs remains, these miRNAs may be novel biomarkers for obesity.