Nuclear receptors are central regulators of fat and glucose metabolism. Moreover, they have been implicated in the modulation of the inflammatory response. Here the authors present data demonstrating a prominent expression of the nuclear receptor NR4A1 in different cells of the monocytic lineage including macrophages and osteoclasts.

Deletion of NR4A1 enhanced the inflammatory response of macrophages in vitro, which included elevated expression of proinflammatory cytokines. To determine the role of this nuclear receptor in an experimental model of inflammatory arthritis, the authors performed a K/BxN serum transfer model in WT and NR4A-/- mice, observing an exacerbation of arthritis in NR4A-deficient mice.

Together these data demonstrate a crucial role for the nuclear receptor NR4A1 in the regulation of the inflammatory response in vitro and in vivo.