(miRNAs) from bone marrow mesenchymal stem cells (BMSCs) in a rat model of steroid-induced osteonecrosis of the femoral head (ONFH) using Affymetrix GeneChip®. Following identification of miRNAs, the present study aimed to elucidate the molecular mechanisms underlying steroid-induced ONFH

The present study aimed to identify microRNAs (miRNAs) from bone marrow mesenchymal stem cells (BMSCs) in a rat model of steroid-induced osteonecrosis of the femoral head (ONFH) using Affymetrix GeneChip®. Following identification of miRNAs, the present study aimed to elucidate the molecular mechanisms underlying steroid-induced ONFH. A total of six C57BL/6J mice were randomly divided into two groups, control and experimental groups (n=3 per group). The mice in the experimental group were subcutaneously injected with 21 mg/kg methylprednisolone for 4 weeks, while the mice in the control group were injected with the identical dose of normal saline. The femoral head was subsequently removed and sectioned. Following sectioning, hematoxylin and eosin staining, and terminal deoxynucleotidyl transferase dUTP nick end labeling were performed to confirm the establishment of the model. To replicate the animal model ex vivo, the bone marrow was isolated. Next, different miRNAs were screened for using GeneChip®, and the key miRNAs were assessed by bioinformatics analysis and their functions were confirmed. Compared with the control, 23 miRNAs in the experimental group were identified, with seven upregulated and 16 downregulated. Of these miRNAs, putative target miRNAs were predicted by bioinformatics analysis, with two being upregulated (miR-21-3p and miR-652-5p) and five downregulated (miR-206-3p, miR-196a-5p, miR-34b-3p, miR-34c-5p and miR-148a-3p). The results of reverse transcription-quantitative polymerase chain reaction were consistent with the gene-chip results. Steroid-induced ONFH may cause miRNA changes in BMSCs. Numerous miRNAs regulate osteogenic differentiation and the decrease in miRNA-196a-5p may be important in steroid-induced ONFH.