Fig 2: Semi-quantitative analysis of the mitochondrial respiratory enzyme complexes in the distal colon of IFN?-/- mice after C. rodentium infection.Immunohistochemical staining using antibodies for (A) MTND6 (complex I) (B) SDHA (complex-II) (C) CYC1 (complex-III) (D) CCO-VIc (complex-IV). Statistics: ANOVA Student Newman-Keuls Multiple Comparison post hoc test: *P < 0.05, **P < 0.01, ***P < 0.001. vs. control.

Fig 3: Semi-quantification of mitochondrial respiratory enzyme complexes of an in vitro intestinal model treated with cytokines and E. coli infection.Immunohistochemical staining using antibodies for (A) MTND6 (complex I) (B) SDHA (complex-II) (C) CYC1 (complex-III) (D) CCO-VIc (complex-IV). Values are mean ± S.E.M. Statistics: ANOVA with Student Newman-Keuls Multiple Comparison post hoc test: *P < 0.05, **P < 0.01, ***P < 0.001.

Fig 4: Tissue localization and semi-quantification of the mitochondrial respiratory enzyme complexes in the murine distal colon during C. rodentium infection.Immunohistochemical staining using antibodies for (A) MTND6 (complex I) (B) SDHA (complex-II) (C) CYC1 (complex-III) (D) CCO-VIc (complex-IV). Statistics: unpaired t test. *P < 0.05, **P < 0.01, ***P < 0.001 vs. control, n = 5–6 mice/group. The infection experiments were performed twice, and each time point contain results pooled from 5–6 mice. Scale bar 100 µm, magnification × 200.

Fig 5: Effects of VIP on restoring the decreased levels of mitochondrial respiratory enzyme complexes caused by cytokines and C. rodentium infection in vitro.An in vivo like in vitro intestinal mucosal model was treated with cytokines and infected in the presence and absence of VIP, stained immunohistochemically and the intensity of the stain was scored. (A) Semi-quantification for complex I (MTND6 antibody), (B) complex-II (SDHA antibody) (C) complex-III (CYC1 antibody) and (D) complex-IV (CCO-VIc antibody). Statistics: data are presented as mean ± S.E.M. (n = 4, biological replicates, results were pooled from two separate experiments) and analyzed by ANOVA with Student Newman-Keuls Multiple Comparison post hoc test: * P<0.05, ** P<0.01, *** P<0.001.