Inhibition of cyclooxygenase-2 activity in subchondral bone modifies a subtype of osteoarthritis.

Osteoarthritis (OA) causes the destruction of joints. Its pathogenesis is still under investigation, and there is no effective disease-modifying therapy. Here, we report that elevated cyclooxygenase-2 (COX-2) expression in the osteocytes of subchondral bone causes both spontaneous OA and rheumatoid arthritis (RA).

Inhibition of overactive TGF-β attenuates progression of heterotopic ossification in mice.

Acquired heterotopic ossification (HO) is a painful and debilitating disease characterized by extraskeletal bone formation after injury. The exact pathogenesis of HO remains unknown. Here we show that TGF-β initiates and promotes HO in mice.

MiR-497∼195 cluster regulates angiogenesis during coupling with osteogenesis by maintaining endothelial Notch and HIF-1α activity.

A specific bone vessel subtype, strongly positive for CD31 and endomucin (CD31Emcn), is identified as coupling angiogenesis and osteogenesis. The abundance of type CD31Emcn vessels decrease during ageing. Here we show that expression of the miR-497∼195 cluster is high in CD31Emcn endothelium but gradually decreases during ageing.

GDF11 Inhibits Bone Formation by Activating Smad2/3 in Bone Marrow Mesenchymal Stem Cells.

Growth differentiation factor 11 (GDF11) is a member of the transforming growth factor-β superfamily. Recent studies confirmed that GDF11 plays an important role in regulating the regeneration of brain, skeletal muscle, and heart during aging; however, its role in bone metabolism remains unclear. Thus, the aim of this study was to determine the effects of GDF11 on bone metabolism, including bone formation and bone resorption, both in vitro and in vivo.

MiR-142-5p promotes bone repair by maintaining osteoblast activity.

MicroRNAs play important roles in regulating bone regeneration and remodeling. However, the pathophysiological roles of microRNAs in bone repair remain unclear. Here we identify a significant upregulation of miR-142-5p correlated with active osteoblastogenesis during the bone healing process.