FIG 6.

GDNF mRNA and protein levels were significantly higher in the duodenum of rotavirus-infected mice. (A) The duodenum of infected (n = 8) and noninfected (n = 7) mouse pups were collected at 16 h p.i., and the Gdnf and TATA-binding protein (Tbp) mRNA levels were quantified using qPCR. There was significant upregulation of Gdnf mRNA in the infected mice. Data are means ± SEM. *, P < 0.05, unpaired t test. (B) The duodenum of infected and noninfected mouse pups were collected at 16 h p.i., and the GDNF protein levels were measured using ELISA. The infected mice had significantly higher levels of GDNF protein than the noninfected controls. Four biopsy specimens from noninfected pups had GDNF protein concentrations below the ELISA detection limit. Data are medians with interquartile range. *, P < 0.05, Mann-Whitney test (n = 5). (C and D) GDNF was present in the enterocytes of mouse small intestine, mainly in the middle and tip of the villi. Immunofluorescence staining shows GDNF (green, Alexa Fluor 488) in the ileal enterocytes of rotavirus-infected mouse pups (red, Alexa Fluor 594) at 16 h p.i. (C) and noninfected mouse pups (D). The tissue was counterstained with 4′,6‐diamidino‐2‐phenylindole (DAPI) nuclear stain.