Dysregulation of miR-21-5p in children with obesity and its predictive value for metabolic syndrome

Background: microRNAs (miRNAs) could mediate the glucose and lipid metabolism progress in metabolic syndrome (MetS).

Objectives: To analyze the value of miRNA (miR)-21-5p for MetS diagnosis in children with obesity. Function of miR-21-5p has been explored by the prediction of target genes and functional and pathway enrichment analysis.

Methods: Relative miR-21-5p level was examined by qRT-PCR. Predictive value of miR-21-5p for MetS was assessed by ROC curve. miRBase, TargetScan, and miRWalk databases were used to screen the target genes of miR-21-5p. GO and KEGG were operated to analyze the function of candidate genes of miR-21-5p.

Results: Overexpressed miR-21-5p was discovered in MetS children (P < 0.001). High miR-21-5p level could predict MetS patients from children with obesity. Serum miR-21-5p level was closely related to BMI (r = 0.631, P < 0.001), FBG (r = 0.341, P < 0.001), Fasting Insulin (r = 0.438, P < 0.001), TG (r = 0.662, P < 0.001), SBP (r = 0.432, P < 0.001), DBP (r = 0.524, P < 0.001), and HDL-C (r = -0.201, P < 0.001). High miR-21-5p level could predict MetS patients from children with obesity (AUC= 0.827, sensitivity= 0.750, specificity=0.806, cutoff value= 1.0293, P < 0.001). Venn diagram found 83 intersection genes among 3 databases. GO and KEGG analyses indicated that candidate genes of miR-21-5p were mainly correlated with Axon guidance, FoxO signaling pathway, cytokine-cytokine receptor interaction, and insulin resistance pathways.

Conclusion: Blood miR-21-5p was elevated in MetS children, and could predict MetS subjects from children with obesity. miR-21-5p could regulate the MetS development via FoxO signaling pathway and insulin resistance pathways.