Expression and Correlation of Circulating miRNAs in Healthy Obese Children

Abstract Objective: Obesity is an important risk factor of metabolic diseases. It is caused by the interaction of genetic, epigenetic, and environmental factors. This study aimed to identify specific circulating miRNAs for evaluating obesity in children. Methods: Thirty children including 15 obese and 15 extremely thin were selected. The miRNA microarray was used to detect the expression of miRNAs in circulating plasma. The reliability of differential miRNA expression was verified using TaqMan qPCR. The correlation between miRNA and obesity was analyzed using multiple linear regression. Target genes for selected miRNAs were analyzed using informatics tools, and a functional network map was constructed. Results: Thirty-six differential expression miRNAs were screened by gene chip, and seven up-regulated miRNAs were verified by TaqMan qPCR, including hsa-miR-126-3p, hsa-miR-15b-5p, hsa-miR-199a-3p, hsa-miR-20a-5p, hsa-miR-223-3p, hsa-miR-23a-3p, and hsa-miR-24-3p. Six miRNAs had significant statistical difference except hsa-miR-23a-3p. Multiple linear regression analysis showed that hsa-miR-15b-5p and hsa-miR-223-3p were associated with obesity [1.649 (4.974-16.084), -1.175 (-17.852~ -2.657)]. After adjusting for age and gender, these two miRNAs were still associated with obesity [1.400 (3.572-14.301), -0.973 (-15.634~ -1.303)]. Among them, hsa-miR-15b-5p and hsa-miR-223 had more predicted obesity-related target genes than others. In particular, hsa-miR-15b-5p had numerous target genes associated with the FoxO, insulin, Ras, and AMPK signaling pathways. Conclusion: The miRNA expression profile in the body circulation of obese children differs from normal children. This result is attributed to the abnormal metabolism of obese children. hsa-miR-15b-5p and hsa-miR-223-3p could serve as a molecular marker for screening obese children and susceptible population of metabolic syndrome.