Figure 4. Inhibition of DSS-induced IEC apoptosis in PUMA-KO mice.
After treatment of WT and PUMA-KO mice with 5% DSS for 7 days, several methods were used to analyze apoptosis. (A) Genomic DNA isolated from colonic mucosa was analyzed by agarose gel electrophoresis. (B) TUNEL staining of colonic tissues from the treated mice (original magnification, ×200). (C) The apoptotic index was measured by counting TUNEL signals in 100 randomly selected crypts. Values were mean ± SD (n = 3 in each group). (D) TUNEL (green) and cytokeratin (red) double staining of colonic tissues from the treated mice (original magnification, ×400). (E) Cytochrome c release was analyzed by probing the cytosolic and mitochondrial fractions of colonic mucosa using Western blotting. β-Actin and Cox IV, which are expressed in cytosol and mitochondria, respectively, were used as the controls for loading and fractionation. (F) Active caspase-3 was probed by Western blotting.