Figure 6.

Activation of the PXR provides protection against the colonic inflammation and injury prompted by TcdA/B exposure. C57Bl/6 mice were treated with the mouse‐specific PXR agonist pregnenolone 16α‐carbonitrile (PCN; in sterile corn oil vehicle) 48, 24, and 0.5 h prior to intrarectal instillation of TcdA/B. A, Colonic expression of the PXR target gene Cyp3a11 in mice following treatment with vehicle or PCN. B, Representative FACS plots and (C) associated cell frequencies and counts of infiltrating Ly6G + neutrophils in the colon. D, representative histological images and total damage scores, and (E) the expression of various cytokines in colon 4 h after vehicle‐ or PCN‐treated mice were exposed to TcdA/B. Gene expression was normalized to β‐actin (Actb). All data are expressed as SEM (n = 4‐6 per group). Student's t test, *P < .05, ***P < .005