A pathogen-derived effector modulates host glucose metabolism by arginine GlcNAcylation of HIF-1α protein
Fig 8
NleB enhances glucose metabolism-associated genes known to be downstream of HIF-1α in vivo.
(A) Slc2a1 (Glut1) and Pkm2 were enhanced by NleB in mouse colon. Male C57BL/6 mice (5–6 weeks old; 17–19 g/mouse) were orally gavaged with the wild-type C. rodentium DBS100 strain, ΔnleB strain, or were uninfected; the mutant strain was complemented with a plasmid expressing wild-type NleB (pNleBc) or the GlcNAc transferase-deficient D221A/D223A mutant (pNleBc-DXD). After 8 days, total RNA was extracted from colons (n = 5 mice for each group), and the expressions of Slc2a1 (Glut1) and Pkm2 were examined by semi-quantitative RT-PCR. (B) Knocking-down HIF-1α by PX-478 rescued the enhancement of Slc2a1 (Glut1) and Pkm2 by NleB in mouse colon. Male C57BL/6 mice (5–6 weeks old; 17–19 g/mouse) were injected intraperitoneally with PX-478 (30 μg/g) or PBS control for 48 h, followed by oral gavage with the indicated C. rodentium strains or were uninfected. After 8 days, total RNA was extracted from colons (n = 5 mice for each group), and the expressions of Slc2a1 (Glut1) and Pkm2 were examined by semi-quantitative RT-PCR. P-values were calculated using 2-way ANOVA. (C) Protein levels of Ldha, Pkm2, and Vegf were enhanced by NleB in mouse colon. Male C57BL/6 mice (5–6 weeks old; 17–19 g/mouse) were orally gavaged with the wild-type C. rodentium DBS100 strain or ΔnleB strain. After 8 days, the protein levels of Ldha, Pkm2, and Vegf were examined by western blot (n = 3 mice for each group). (D) Slc2a1 (Glut1) expression was enhanced by NleB in mouse colon. Male C57BL/6 mice (5–6 weeks old; 17–19 g/mouse) were orally gavaged with the wild-type C. rodentium DBS100 strain, ΔnleB strain, or were uninfected. After 8 days, the expression of Slc2a1 (Glut1) was detected by immunofluorescent staining.