Presence and function of microRNA-92a in chondrogenic ATDC5 and adipose-derived mesenchymal stem cells.

The aim of the present study was to investigate the presence and biological function of microRNA-92a (miR-92a) in chondrogenesis and cartilage degeneration. Human adipose‑derived mesenchymal stem cells (hADSCs) in micromass and chondrocyte‑like ATDC5 cells were induced to chondrogenesis, and primary human/mouse chondrocytes (PHCs/PMCs) and chondrogenic ATDC5 cells were stimulated with interleukin‑1β (IL‑1β). An miR‑92a mimic/inhibitor was transfected into the ATDC5 cells using lipofectamine 2000. Gene expression was analyzed using reverse transcription‑quantitative polymerase chain reaction. Alcian blue was used to stain the cartilage nodules and chondrogenic micromass. The potential target genes, signaling pathways and functions of miR‑92a were examined using miRanda, miRDB, CLIP‑Seq, TargetScan and Kyoto Encyclopedia of Genes and Genomes. The expression of miR‑92a was elevated in the chondrogenic ATDC5 cells and hADSCs, and also in the IL‑1β‑induced ATDC5 cells, PMCs and PHCs. Forced expression of miR‑92a enhanced the expression levels of col9a2 and aggrecan. A total of 279 genes were predicted as potential target genes of miR‑92a. The phosphoinositide 3‑kinase/PI3K)‑Akt, ErbB and focal adhesion kinase pathways, extracellular matrix (ECM)‑receptor interaction and the mammalian target of rapamycin (mTOR) signaling pathway were suggested to mediate the effects of miR‑92a on chondrogenesis and cartilage degeneration. These results demonstrated that miR‑92a was involved in chondrogenesis and the chondrocyte response induced by IL‑1β. miR‑92a positively contributed to the expression of col9a2 and of aggrecan.