GS143

GS143 is a selec­tive IκBα ubiquitination inhibitor with an IC₅₀ of 5.2 μM for SCF^βTrCP1-mediated IκBα ubiquitylation. GS143 sup­presses NF-κB acti­va­tion and tran­scrip­tion of tar­get genes and does not inhibit proteasome activity. GS143 has anti-asthma effect^[1][2]. IC50 & Target: IC50: 5.2 μM (SCF^βTrCP1-mediated IκBα ubiquitylation)^[2] In Vitro: GS143 (10 μM or 20 μM) inhibits antigen-induced differentiation of Th2 cells but not of Th1 cells in vitro. The IL-4 pro­duc­tion in Th2-polar­iz­ing con­di­tion is mark­edly sup­pressed by GS143 in a dose-depen­dent man­ner^[1].
GS143 suppresses the transcription of TNFα-induced NF-κB with a mean IC₅₀ value of 10.5 μM. GS143 also inhibits TNFα-induced expression of ICAM-1 in HT-29 colon cancer cells with an IC₅₀ value of 6.1 μM. The production levels of TNFα and IL-1β in LPS-activated THP-1 cells are inhibited with IC₅₀ values of 5.3 μM and 2.1 μM, respectively. GS143 does not inhibit p53 and β-catenin^[2]. In Vivo: GS143 (16-32 μg/body; intranasal administration; once; BALB/c mice) treatment suppresses antigen-induced NF-κB activation in the lung of sensitized mice. GS143 treatment also inhibits antigen-induced eosinophil and lymphocyte recruitment into the airways and the expression of Th2 cytokines and eotaxin in the airways^[1].