CCL2 and colitis: Without GUSi, exposure to TCS exacerbated DSS-induced colitis: compared with vehicle, TCS treatment reduced colon length (Fig. 5b), caused more severe crypt damage (Fig. 5c), enhanced colonic infiltration of immune cells, including CD45+ leukocytes, CD45+ F4/80+ macrophages, and CD45+ Gr1+ neutrophils (Fig. 5d), and increased expression of pro-inflammatory genes (Tnf-a, Mcp-1, Il-6, Il-17, and Il-23) in the colon (Fig. 5e).