High-throughput sequencing to identify microRNA signatures during hepatic differentiation of human umbilical cord Wharton's jelly-derived mesenchymal stem cells.

AIM: MicroRNAs (miRNAs) constitute a class of small non-coding RNAs involved in regulation of cognate mRNAs post-transcriptionally. MicroRNAs have been implicated in regulating the stem cell differentiation process. Limited regulatory miRNAs have been reported to date during hepatic differentiation of stem cells. The present study was designed to identify the signature miRNAs implicated in hepatic differentiation of stem cells using next-generation sequencing methods.

METHODS: We undertook sequencing of miRNAs isolated from three different time points during hepatic differentiation of human umbilical cord Wharton's jelly-derived mesenchymal stem cells (hUC-MSCs) from two biological replicates.

RESULTS: Out of a total known 2588 miRNAs (according to miRBase version 21), 880 miRNAs were identified in our study. A total of 63 significantly expressed miRNAs during hepatic differentiation, with at least 2-fold change and a false discovery rate value <0.05, were considered for further analysis. The putative target genes of significantly downregulated miRNAs during hepatic differentiation appeared to be mostly associated with biological processes that are essential for hepatic differentiation and maintenance of mature hepatic phenotype-like liver development, stem cell differentiation, Wnt receptor signaling pathway, and drug and cholesterol metabolic processes. Putative target genes of significantly upregulated miRNAs are highly enriched in regulating processes that block hepatic differentiation of hUC-MSCs like epithelial-mesenchymal transition, transforming growth factor-β receptor signaling pathway, and stem cell maintenance.

CONCLUSION: The study provides a new insight for investigation of miRNA-regulated pathways during the differentiation process.