Circulating mRNA and miRNA Signatures as Predictive Markers of Lifestyle Modification Outcomes in Pediatric Obesity Treatment

Context: The response to lifestyle modification (LSM) in children with obesity is variable and difficult to predict. Aim: A systematic search for molecular markers to predict outcomes of LSM in pediatric obesity management. Patients/Methods: Out of 240 children with obesity (BMI>97%) recruited to a prospective ‘multi-OMICS’ study granted by ESPE Research Unit, 159 subjects (age 8-17 yrs, median 12.8 yrs; 45% females) finished twelve-months (V12) of LSM obesity management at three centers in Poland, Turkey and Italy. Four of >180 baseline clinical/laboratory (V0) features (sex/age/severity of obesity at V0/delta z-score BMI V12-V0) were used to select 50 representatives for RNA-seq analysis. We searched for circulating mRNA & miRNA capable of predicting the response to LSM defined by a decrease in z-score BMI (Responders/RS). First, the candidate gene approach with previously documented STAT3, CORO1C, SERPINH1, MVP, ITGB5 (upregulated in obesity), PCM1, SIRT1, EEF1G, PTEN and RPS2 (down-regulated in obesity) hub genes was applied. The pairwise ratios of transcripts per million (TPM)s of these genes were tested for statistical significance between RS (n=31) and non-RS (n=19) groups. Secondly, the TPM expression values of 2,129 miRNAs and 33,246 RPL13Anormalized mRNAs were compared between RS and non-RS to get a list of putative significant genes (p < 0.05; the Welch t-test). Enrichr, a web-based tool (http://amp.pharm.mssm.edu/Enrichr), was used for analysing gene sets. Results: Expression values for 909 mRNA and 24 miRNA genes were significantly different between RS vs non-RS. For example, STAT3/PTEN, CORO1C/PTEN, MVP/PTEN; miRNA10a, miRNA-122, miRNA-127, miRNA-502, miRNA-210 were significantly higher and SIRT1/PTEN, EEF1G/PTEN, RPS2/PTEN, miRNA-27a were lower comparing RS vs. non-RS (p= 0.009, 0.022, 0.030, 0.048, 0.029, 0.045, 0.035, 0.020, 0.047, 0.04, 0.039, 0.029, respectively). Several pathways, including “Vitamin B6 metabolism” and “Insulin receptor signaling”, were enriched in our differentially expressed mRNA (p<0.001): PNPO, PHOSPHO2, PDXP, PSAT1 were up-regulated in RS vs. non-RS. “Leptin signaling pathway WP2034” were enriched in STAT3 and PTEN (p<0.0001). Conclusions: The role of the balance between STAT3 and PTEN in LSM was discovered. The importance of previously described miRNA markers (miRNA-122, miRNA-127, miRNA27a) related to adipogenesis risk, insulin resistance, hepatic fat reduction, PPAR-γ expression were confirmed. A combination of the previously reported V0 Leptin feature together with STAT3/ PTEN and miRNA-27a levels showed promising predictive results. Our findings not only showed the predictive molecular markers but also pointed to their role in personalization of therapeutic management.