Changed cellular functions and aberrantly expressed miRNAs and circRNAs in bone marrow stem cells in osteonecrosis of the femoral head

The present study aimed to detect the correlations between altered cellular functions in bone marrow stem cells (BMSCs) and osteonecrosis of the femoral head (ONFH). By profiling the aberrant expression of miRNAs and circRNAs in BMSCs isolated from ONFH patients, the present study aimed to further explore the potential regulatory mechanisms of action of circRNAs in ONFH using integrated bioinfor-matics analysis. BMSCs were isolated from seven ONFH patients and seven controls. Cellular functions, including proliferation, apoptosis and differentiation, were compared. miRNA and circRNA sequencing were conducted using RNA samples of three ONFH patients and three controls to identify differentially expressed circRNAs and miRNAs. The expression of hsa_circ_0000219, hsa_circ_0004588 and hsa_circ_0005936 were validated by qPCR. Target miRNAs were also predicted and validated by qPCR and circRNA-miRNA co-expression networks were constructed. BMSCs of ONFH patients displayed decreased proliferation and increased apoptosis during in vitro culturing. In addition, reduced osteogenesis and enhanced adipogenesis were found in the ONFH group. A total of 129 miRNAs and 231 circRNAs were detected to be differentially expressed. The expression levels of hsa_circ_0000219, hsa_circ_0004588 and hsa_circ_0005936 were significantly decreased in BMSCs of ONFH patients. A number of target miRNAs related to cell proliferation, apoptosis and differentiation were predicted for hsa_circ_0000219 and hsa_circ_0005936. The expression levels of miR-144-3p and miR-1270 were found to be elevated in ONFH patients, which was consistent with miRNA sequencing data and competitive endogenous RNA hypothesis. Time-dependent expression patterns of hsa_circ_0000219, hsa_circ_0004588, hsa_circ_0005936, miR-144-3p and miR-1270 were also validated during osteogenic and adipogenic differentiation in BMSCs. The results of the present study substantiated the involvement of BMSCs in ONFH development. hsa_circ_0000219 and hsa_circ_0005936 may regulate the progression of ONFH by mediating the proliferation and differentiation of BMSCs by sponging miRNAs.