SAR-20347

Kinase experiment:

Kinases are prepared in Base Reaction Buffer (20 mM Hepes pH 7.5, 10 mM MgCl2, 1 mM EGTA, 0.02% Brij35, 0.02 mg/mL BSA, 0.1 mM Na3VO4, 2 mM DTT, 1% DMSO) and substrate is added with 1.5 mM CaCl2, 16 μg/mL Calmodulin, and 2 mM MnCl2. Varying concentrations of SAR-20347 in DMSO are added to the kinase reaction along with 10 μM 33P-ATP (activity 0.01 μCi/μL final) for IC50 determination[1].

Cell experiment:

Cells are plated in a 96-well v-bottom plate in starvation medium, incubated with SAR-20347 (0.5% DMSO) for 20 minutes at 37°C, 5% CO2, and stimulated with individual cytokines. P-STAT levels are measured in duplicate using MSD plates following the manufacturer's instructions (MSD). The IC50 is determined by subtracting background (no cytokine) and relative to DMSO/cytokine control[1].

Animal experiment:

Female 7 to 9 week old C57BL/6 mice are used. Mice are administered vehicle or 50 mg/kg SAR-20347 by oral gavage 30 minutes prior to application of 62.5 mg 5% imiquimod cream or control cream. Another dose of vehicle or 50 mg/kg SAR-20347 is given 5.5 hours following the first dose. This treatment is repeated for 5 days and on day 3 and 4, animals are injected with 100 uL saline to prevent dehydration. Each day, the mice are assessed by the same researcher for redness. On the 6th day, the animals are euthanized and photographs are taken[1].

References:

[1]. Works MG, et al. Inhibition of TYK2 and JAK1 ameliorates imiquimod-induced psoriasis-like dermatitis by inhibiting IL-22 and the IL-23/IL-17 axis. J Immunol. 2014 Oct 1;193(7):3278-87.