FIG 5.

Protein malnutrition suppressed intestinal epithelial cell proliferation induced by C. parvum. C57BL/6 mice at postnatal day 28 were fed with an isocaloric low-protein (2% protein) diet or control diet containing 20% protein and simultaneously challenged with 2 × 10⁷ unexcysted oocysts per mouse and then euthanized 20 h later. (A) Equal amounts of total proteins from ileal epithelial cells were Western blotted against PCNA and GAPDH antibodies. After densitometry quantification and normalization against GAPDH, the fold change of the protein level relative to nourished uninfected group is shown as the mean ± SEM (n = 3). (B) Immunostain of uninfected or infected ileum with different nutritional statuses for Ki67. (C) Quantification of Ki67-positive epithelial cells in ileal crypts. Ki67-positive cells were measured in 10 crypts each mouse (n = 3). *, P < 0.05 compared with nourished uninfected; ♦, P < 0.05 compared with malnourished uninfected; ●, P < 0.05 compared with nourished infected. Similar results were obtained from three independent experiments.