Figure 3

Identification of different cell types expressing GATA-4 and GATA-6 proteins in normal gastrointestinal mucosa. Staining for chromogranin A (ChrA) (blue-greyish cytoplasmic staining in A, A', C, C', F, and F') was used to detect neuroendocrine cells and staining for H+/K+-ATPase α (HK) (blue-greyish cytoplasmic staining in B and B' to detect parietal cells. The samples were double-stained for GATA-4 (G4) or GATA-6 (G6) (brown nuclear staining). The GATA proteins are not expressed in the neuroendocrine cells of the stomach, duodenum, or colon (A, A', C, C', F and F' respectively; arrowheads). GATA-4 is detected in the H+/K+-ATPase α presenting parietal cells (B). GATA-6 is positive in approximately two thirds of the parietal cells positive for H+/K+-ATPase α (B', arrowheads). Some duodenal goblet cells, stained deep blue by the Alcian blue method (Alc) (D'), and most Paneth cells are positive for GATA-6 (E', arrowhead) showing no immunoreactivity for GATA-4 (D and E, arrowheads). Scale bar = 50 μm.