MicroRNA expression analysis during FK506-induced osteogenic differentiation in rat bone marrow stromal cells

FK506 (also known as tacrolimus) is a potent immunosuppressive agent that is widely used in the treatment of graft-rejection and autoimmune diseases. FK506 has attracted additional attention owing to its potential role in osteogenic differentiation and bone formation. MicroRNAs (miRNAs) have been demonstrated to serve important roles in the regulation of osteogenic differentiation; however, identification of specific miRNAs and their roles in regulating FK506-induced osteogenic differentiation have been poorly examined. In the present study, osteodifferentiation of rat bone marrow stromal cells (BMSCs) was induced with varying concentrations of FK506 (5–5,000 nM) for 3, 7 and 14 days. Differentially expressed miRNAs were profiled using miRNA array, verified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and subjected to gene ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Results from the present study identified a subset of miRNAs that were differentially expressed, of which five upregulated miRNAs (miR-106b-5p, miR-101b-3p, miR-193a-3p, miR-485-3p and miR-142-3p) and four downregulated miRNAs (miR-27a-3p, miR-207, miR-218a-2-3p and let-7a-5p) were confirmed by RT-qPCR. GO and KEGG analysis revealed that the predicted target genes of these miRNAs are involved in multiple biological processes and signaling pathways, including cell differentiation and the mitogen-activated protein kinase (MAPK) signaling pathway. Verification of the miRNA-target genes revealed that Smad5, Jagged 1 and MAPK9 were significantly upregulated, whereas Smad7, BMP and activin membrane-bound inhibitor, and dual-specificity phosphatase 2 were significantly downregulated during FK506-induced osteodifferentiation. The present study may provide an experimental basis for further research on miRNA functions during FK506-induced osteogenic differentiation in rat BMSCs.