Expression data from mouse colon tissue in activated T cell transfer colitis model treated with MEK inhibitor or anti-TNFa antibody

We analyzed publicly available mucosal gene expression data from Crohn''s disease (CD) patients pre- and post-infliximab therapy and found that a series of gene expression signature that remains abnormal even if patients achieve clinical remission. Using CMap approach to discover novel therapeutic target for untreatable mechanism of anti-TNFa mAb therapy, we have identified MEK inhibitor exhibiting negatively-correlated effects on reference signature match infliximab therapy untreatable signature. Our findings provide the rationale for testing MEK inhibitor to identify a novel mechanism of action for CD. Using an activated T cell trasnfer colitis model, a highly selective MEK inhibitor showed therapeutic efficacy and improved the histological changes. To dissect molecular mechanisms, we performed global gene expression profile by RNA-sequencing on the Ion Torrent platform to identify broad scale changes in gene expression treated with MEK inhibitor compared to anti-TNFa mAb. Overall design: Splenocytes from BALB/c female mice were activated with Concanavalin A (4 µg/mL), and recombinant human IL-2 (10 ng/mL, R&D systems) for 3 days. CD4+ T cells were isolated by MACS separation systems, and then 2 x105 activated CD4+ T cells were intravenously injected into female SCID mice (day 0). At day 17, diarrhea score for stool consistency was graded and equally divided into 5 groups as follows: vehicle control, enteric MEK inhibitor microparticles (MPs) at 0.3 mg/kg and at 1 mg/kg, isotype antibody (Isotype mAb) and anti-TNFa antibody (Anti-TNFa mAb). Enteric MEK inhibitor MPs were orally administered once a day from day 17 to day 27. Isotype mAb and anti-TNFa mAb were intraperitoneally injected every 4 days from day 17 at 0.1 mg/mouse. Total RNA from individual cohorts were extracted from the distal part of the colon at day 28, and whole transcriptome sequencing was performed on the Ion Torrent platform. MEK inhibitor (compound 33 in Bioorg. Med. Chem. Lett. 22 (2012) 2411 2414))

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Gamo K, Okuzono Y, Yabuki M, Ochi T, Sugimura K, Sato Y, Sagara M, Hayashi H, Ishimura Y, Nishimoto Y, Murakawa Y, Shiokawa Z, Gotoh M, Miyazaki T, Ebisuno Y