12 February 2020
Vol 12, Issue 530

About The Cover

Cover image expansion

ONLINE COVER Bolstering Bone Formation. These computed tomography images show bone erosion in a finger joint of an individual with rheumatoid arthritis before (left) and after (right) 2 years of treatment with a Janus kinase (JAK) inhibitor. JAK inhibitors are approved treatments for rheumatoid arthritis that reduce inflammation. Adam et al. studied whether these drugs have bone-specific antiresorptive effects. Treatment with JAK inhibitors increased bone mass under steady-state conditions in healthy mice, halted bone loss in mouse models of osteoporosis and arthritis, and repaired bone erosions in two individuals with rheumatoid arthritis. Results support use of JAK inhibitors as potential osteoanabolic agents that enhance the activity of bone-forming osteoblasts. [CREDIT: ADAM ET AL./SCIENCE TRANSLATIONAL MEDICINE]