Peripheral blood mononuclear cells-expressed miRNA profiles derived from children with metabolic-associated fatty liver disease and insulin resistance.

BACKGROUND: miRNA have been proposed as potential biomarkers of metabolic diseases. OBJECTIVES: To identify potential miRNA biomarkers of early metabolic-associated fatty liver disease (MAFLD) and/or insulin resistance (IR) in preadolescent children. METHODS: A total of 70 preadolescents, aged 8.5-12 years old participated in the study. Hepatic fat was assessed by magnetic resonance imaging. Fasting blood biochemical parameters were measured and HOMA-IR calculated. Peripheral blood mononuclear cells (PBMC)-derived miRNA profiles associated with MAFLD (≥5.5% hepatic fat) and IR (HOMA-IR ≥2.5) were identified using untargeted high-throughput miRNAs sequencing (RNA-seq). RESULTS: A total of 2123 PBMC-derived miRNAs were identified in children with (21.4%) or without MAFLD. Among them, hsa-miR-143-3p, hsa-miR-142-5p and hsa-miR-660-5p were up-regulated, and p-hsa-miR-247, hsa-let-7a-5p and hsa-miR-6823-3p down-regulated. Importantly, children with MAFLD had consistently higher miR-660-5p expression levels than their peers without it (p < 0.01), regardless of weight status. A total of 2124 PBMC-derived miRNA were identified in children with IR (28.6%) versus children without IR, where thirteen of them were dysregulated (p < 0.05) in children with IR. In addition, children with IR showed higher levels of miR-374a-5p and miR-190a-5p (p < 0.01) and lower levels of miR-4284 and miR-4791 (p < 005), than their peers without IR in both the whole sample and in those with overweight or obesity. CONCLUSIONS: Our study results suggest circulating miR-660-5p as a potential biomarker of the presence of MAFLD in preadolescent children while circulating miR-320a, miR-142-3p, miR-190a-5p, miR-374a-5p and let-7 family miRNAs could serve as potential biomarkers of IR in children.

Circulating miRNAs as Biomarkers of Obesity and Obesity-Associated Comorbidities in Children and Adolescents: A Systematic Review.

Early detection of obesity and its associated comorbidities in children needs priority for the development of effective therapeutic intervention. Circulating miRNAs (microRNAs) have been proposed as biomarkers for obesity and its comorbidities; therefore, we conducted a systematic review to summarize results of studies that have quantified the profile of miRNAs in children and adolescents with obesity and/or associated disorders. Nine studies aiming to examine differences in miRNA expression levels between children with normal weight and obesity or between obese children with or without cardiometabolic diseases were included in this review. We identified four miRNAs overexpressed in obesity (miR-222, miR-142-3, miR-140-5p, and miR-143) and two miRNAs (miR-122 and miR-34a) overexpressed in children with obesity and nonalcoholic fatty liver disease (NAFLD) and/or insulin resistance. In conclusion, circulating miRNAs are promising diagnostic biomarkers of obesity-associated diseases such as NAFLD and type 2 diabetes already in childhood. However, more studies in children, using massive search technology and with larger sample sizes, are required to draw any firm conclusions.