Science Signaling 2015-11-24

The early synthesis of p35 and activation of CDK5 in LPS-stimulated macrophages suppresses interleukin-10 production.

Yi Rang Na, Daun Jung, Gyo Jeong Gu, Ah Ram Jang, Yoo-Hun Suh, Seung Hyeok Seok

Index: Sci. Signal. 8 , ra121, (2015)

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Abstract

Interleukin-10 (IL-10) is an important anti-inflammatory cytokine that is produced primarily by macrophages. We investigated mechanisms by which the timing of IL-10 production was controlled in macrophages and found that cyclin-dependent kinase 5 (CDK5) activity was markedly increased in lipopolysaccharide (LPS)-stimulated macrophages through the synthesis of the CDK5-binding partner and activator p35. Degradation of p35 released the inhibition on anti-inflammatory signaling mediated by CDK5-p35 complexes. The transiently active CDK5-p35 complexes limited the LPS-stimulated phosphorylation and activation of various mitogen-activated protein kinases (MAPKs), thereby preventing the premature production of SOCS3 (suppressor of cytokine signaling 3), an inhibitor of inflammatory responses in macrophages, and IL-10. Furthermore, we showed that dextran sodium sulfate failed to induce colitis in p35-deficient mice, which was associated with the enhanced production of IL-10 by macrophages. Together, our results suggest that CDK5 enhances the inflammatory function of macrophages by inhibiting the MAPK-dependent production of IL-10.Copyright © 2015, American Association for the Advancement of Science.