Updated project metadata. Osteoarthritis is a devastating disease of articular cartilage. The pathogenic factors contributing to this disorder are inflammation, extracellular matrix degradation and failure to rebuild the articular cartilage. Preclinical studies suggest that microRNA-140 (miR-140) may play a protective role in osteoarthritis development, but little is known about the mechanism by which this may occur. Here we present the results of overexpression of miR-140 in an in vitro model of osteoarthritis, evaluated by global proteomics analysis. We show that inflammation is reduced through the differential synthesis of multiple proteins involved in the nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 (NFKB) pathway, articular cartilage regeneration may be induced through the upregulation of many of the components involved in the synthesis of hyaline extracellular matrix, and cartilage degeneration may be reduced through the reduced expression of aggrecanases. Thus, miR-140 overexpression may have a beneficial effect on the development of osteoarthritis through the differential synthesis of a surprisingly large number of proteins involved in all three pathogenic processes. These results show how intraarticular injection of miR-140 may benefit patients suffering from osteoarthritis.