MicroRNA-140 and the silencing of osteoarthritis.

MicroRNAs (miRNAs) have emerged as important modulators in development, tissue homeostasis, and diseases. In this issue of Genes & Development, Miyaki and colleagues (pp. 1173-1185) report that miR-140 is involved in the pathogenesis of osteoarthritis by regulating, at least in part, ADAMTS5. Moreover, mice lacking miR-140 are dwarf as a consequence of impaired chondrocyte proliferation. This study is the first in vivo demonstration that miR-140 has a critical and nonredundant role in cartilage development and homeostasis.