Targeting CDK7 function in the RNA Polymerase II transcription cycle in inflammatory arthritis. Targeting CDK7 function in the RNA Polymerase II transcription cycle in inflammatory arthritis

Macrophages are main drivers of inflammation and tissue damage in autoimmune diseases including rheumatoid arthritis1-4. The rate-limiting step for transcription of >70% of inducible genes in macrophages is RNA Polymerase II (Pol II) promoter-proximal pause release5-7, yet, the specific role of Pol II pausing in inflammation or whether it can be modulated therapeutically is unknown. Genetic ablation of a pause-stabilizing negative elongation factor (NELF) in macrophages enhanced the transcriptional response of paused anti-inflammatory genes to LPS, followed by secondary attenuation of inflammatory signaling, and reduced severity of K/BxN-serum transfer (ST) arthritis in mice. To disrupt Pol II pause establishment pharmacologically, we employed covalent inhibitors of the TFIIH-associated cyclin-dependent kinase (CDK) 7, THZ1 and YKL-5-124. Both dramatically reduced Pol II pausing in murine and human macrophages, broadly suppressed induction of pro- but not anti-inflammatory genes, and rapidly reversed pre-established inflammatory macrophage polarization by TNF+IFNγ. In vivo, CDK7i ameliorated the acute K/BxN-ST and chronic progressive hTNF-transgenic arthritis in mice. Finally, CDK7i downregulated a pathogenic gene expression signature in synovial explants from arthritis patients. We propose that interfering with Pol II pausing by targeting CDK7 represents a novel therapeutic opportunity for inflammatory diseases. Overall design: NOT PROVIDED; REQUESTED