Figure 2.

Loss of ERRα results in impaired intestinal epithelial regeneration, increased cell death and exacerbated DSS-induced colonic inflammation. (a) Immunofluorescence images of colon sections from WT and Esrra^−/− mice on day 8 after 3% DSS treatment stained with antibodies against cleaved caspase-3 and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling), and Hoechst to label nuclei. Zoomed images correspond to boxed regions. (b) Quantification of cleaved caspase-3 positive, TUNEL positive, and double positive cells, per area (mm²) on day 8 following DSS treatment is shown. Data represent the mean ± SEM of 3 mice/genotype. Statistical analysis was performed using Student’s t-test, *p < 0.05. (c) Western blots depicting cleaved caspase-3, phosphorylated RipK1, and beta-actin levels in colon homogenates from 6 WT and 6 Esrra^−/− mice on day 8 after 3% DSS treatment. (d) Immunofluorescence was performed on colon sections derived from WT and Esrra^−/− mice on day 8 after 3% DSS treatment stained with antibodies against proliferating cellular nuclear antigen (PCNA) to mark dividing cells, E-cadherin to mark intestinal epithelial cells (IECs), and Hoechst to label nuclei. (e) The quantification of PCNA⁺ cells per crypt on day 8 following 3% DSS treatment is shown (5–10 crypts were scored/mouse). Data represent the mean ± SEM of n = 3–4 mice/genotype. Statistical analysis was performed using Student’s t-test, **p < 0.001. (f) Immunofluorescence images of colon sections from WT and Esrra^−/− mice on day 8 following 3% DSS treatment stained with antibodies against MUC-2. (g) The quantification of MUC-2 positive cells/mm² on day 8 following 3% DSS treatment is shown. Data represent the mean ± SEM of 3 mice/genotype. Statistical analysis was performed using Student’s t-test, **p < 0.01. ns, not significant. (i) Immunofluorescence staining was performed on colon sections derived from WT or Esrra^−/− mice on day 8 after 3% DSS treatment. The staining was with anti-CD3 antibodies to mark T cells, anti-Ly6G antibodies to mark granulocytes, and Hoechst to label nuclei. (j,k) Quantification of CD3 + and Ly6G + cells/area (mm²) on day 8 following 3% DSS treatment is shown. Data represent the mean ± SEM of n = 3–4 mice/genotype. Statistical analysis was performed using Student’s t-test, *p < 0.05, **p < 0.01. (l) Immunofluorescence staining was performed on colon sections derived from WT or Esrra^−/− mice on day 8 after 3% DSS treatment. The staining was with anti-CD19 antibodies to mark B cells, anti-F4/80 antibodies to mark macrophages, and Hoechst to label nuclei. (m,n) Quantification of CD19+ and F4/80+ cells/area (mm²) on day 8 following 3% DSS treatment is shown. Data represent the mean ± SEM of n = 3–4 mice/genotype. Statistical analysis was performed using Student’s t-test. ns, not significant.