Figure 2

GATA-4, GATA-6, and Ihh protein expression in normal gastrointestinal mucosa. Brown nuclear staining indicates positivity for GATA-4 and GATA-6, and brown cytoplasmic color positivity for Ihh. In contrast to GATA-4 (A), GATA-6 (B) and Ihh (C) are strongly expressed at the bottom of the gastric glands (A, B, and C with insets). In the duodenum (D and E), both GATA-4 and GATA-6 are abundant in the villus enterocytes (D and E). In the ileum (G and H) and colon (J and K), GATA-4 is undetectable (G and J), whereas GATA-6 is abundant in the enterocytes, especially in the crypts (H and K). Some GATA-6 positivity is detected also in the lamina propria. Ihh expression is intense in intraepithelial neuroendocrine cells of the small intestine. Positivity can also be seen in some inflammatory cells of lamina propria, though non-specific absorption by plasma cells cannot be ruled out (F and I, arrowheads). In the colon, the enterocytes and the superficial compartments of the lamina propria are weakly positive for Ihh (L, arrowheads). Scale bars: Black = 200 μm and yellow = 25 μm. Abbreviations: STO = stomach, DUO = duodenum, ILE = ileum, COL = colon.