Pathogenesis of glucocorticoid-induced avascular necrosis: A microarray analysis of gene expression in vitro.

Avascular necrosis of the femoral head (ANFH) occurs following exposure to corticosteroids, and the proliferative capacity of the mesenchymal stem cells (MSCs) belonging to ANFH was reduced. The previous studies indicate that microRNA (miRNA) has an important regulatory role during proliferation and osteogenic differentiation of MSCs. Therefore, MSCs were obtained from healthy adults, and were cultured and osteogenically‑induced by different dexamethasone concentrations. The proliferation and osteogenic differentiation capacities were examined through observing cellular morphology, alkaline phosphatase and alizarin red; miRNA expression was investigated using an miRNA gene chip and miRNA of differential expressions were retrieved through a database to analyze its regulatory effect. Dexamethasone at a concentration of 10(‑7) mol/l induced the proliferation and osteogenic differentiation of MSCs and resulted in evident miRNA expression profile changes. In total, 11 miRNAs were upregulated at 10(‑7) mol/l while 6 were downregulated, and partial miRNA was identified to participate in the regulation of cell proliferation and cell apoptosis, MSC osteogenic differentiation, lipid metabolism and other processes.