Figure 4. The effect of p2TA peptide on COX-2 expression in jejunal crypts.

Expression of COX-2 in mouse intestine: a–h) overview, i–p) details. a–d, i–l) A/J mice; e–h, m–p) BALB/c mice; a,e,i,m) sham irradiated controls; b,f,j,n) mice treated with p2TA peptide six days before tissue harvest; c,g,k,o) mice exposed to 8 Gy gamma rays total body irradiation seven days before the sacrifice; d,h,l,p) mice exposed to 8 Gy gamma rays that received p2TA peptide 24 hours after radiation exposure. In irradiated mice (c,g,k,o) villus integrity is disrupted, their crypts show disorganization, and COX-2 staining is observable in cells in the surface layer of villi. Intestines of irradiated mice that were also treated with 5 mg/kg p2TA peptide 24 hours after irradiation show a more normal morphology with respect to villus height and crypt appearance, and they also show fewer COX-2 positive cells in villi surface cell layer, while COX-2 staining pattern inside villi replicates the pattern seen in sham irradiated mice.