Indirect inhibition of the NLRP3-interleukin-1β axis contributes to the efficacy of JAK1 inhibitors in experimental colitis and human ulcerative colitis.

Liu, Beibei; Spalinger, Marianne R; Invernizzi, Annalisa; Gerdes, Eike; Steglich, Babett; Schwarzfischer, Marlene; Machicote, Andres; Pelczar, Penelope et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Tofacitinib, a pan-Janus kinase inhibitor, and the Janus kinase 1-preferential inhibitors Upadacitinib and Filgotinib are approved for the treatment of ulcerative colitis, yet their molecular mechanisms of action remain incompletely understood. Here, using dextran sulfate sodium-induced and T cell transfer colitis models together with analyses of individuals with ulcerative colitis, we show that all three inhibitors ameliorate colitis in mice with macrophage-specific deletion of protein tyrosine phosphatase non-receptor type 2, a model characterized by hyperactive Janus kinase-signal transducer and activator of transcription signaling. In contrast, only Upadacitinib and Filgotinib provide enhanced protection in wild-type mice - an effect that is lost upon genetic disruption of inflammasome signaling. Longitudinal single-cell transcriptomic analyses and immunostaining of intestinal biopsies further show that Upadacitinib reduces interleukin-1β expression in vivo, which associates with clinical response. Thus, indirect suppression of inflammasome activity contributes to the efficacy of Janus kinase 1-preferential inhibitors.