| Abstract | MicroRNAs are a recently described class of short, non-coding RNAs involved in the regulation of cellular function. Changes in microRNA expression have been identified which may correlate to chondrocyte function and survival indicating a possible role in the pathophysiology of osteoarthritis (OA). Having demonstrated the profound effects of Urocortin (Ucn) on chondrocyte function and survival, we sought to study possible mechanisms for this effect. We have previously shown that Ucn modulates gene expression and have extended these studies to examine the effects of Ucn treatment on chondrocyte miRNAs expression. Dot blot array analysis demonstrated that a number of miRNA’s, in particular miR-9, miR-21, miR-34a, miR-145 and miR-222, were modulated following SNAP (NO) challenge and that those changes were abrogated by concomitant Ucn treatment. Of these, the apparent up-regulation of miRNA 34a, a known pro-apoptotic miRNA, was studied further given the proposed role of chondrocyte apoptosis in the pathogenesis of OA. Transfection of these cells with a miR-34a antagomir resulted in a reduction of SNAP-induced chondrocyte death, in line with that observed with concomitant Ucn treatment. These data suggest a role for microRNA translational control in the maintenance of healthy articular cartilage. |
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