Figure 1

Section of normal human lung treated for the immunohistochemical localization of Wnt7B. Figure1a at low power, airway (A) epithelial cells and smooth muscle (double arrows) surrounding a nearby vessel (V) exhibit reactivity for Wnt7B. Inset of the airway shows Wnt7B reactivity in ciliated cells (solid arrowtip), AT2 cell (single arrow), and smooth muscle (double arrows). The airway insert also shows and non-reactive non-ciliated bronchiolar cell (solid arrowhead). Methylene blue counterstain. Bar = 100 μm; inset Bar = 30 μm. Figure1b, Section of UIP/IPF lung treated for the immunohistochemical localization of Wnt7B. Two large fibroblastic foci (FF) demonstrate strong extracellular reactivity. Bar = 100 μm. Figure1c, Serial section of UIP/IPF lung in Figure1b treated with non-immune serum instead of the Wnt7B-specific antibody. Fibroblastic foci (FF) lack selective staining for the antigen, but show light metachromasia with the methylene blue counterstain. Bar = 100 μm. Figure1d, Serial section of UIP/IPF lung in Figure1b treated for the immunohistochemical localization of Wnt7B after being exposed for 30 minutes to hyaluronidase digestion. The same fibroblastic foci (FF) have lost the strong, extracellular reactivity seen in Figure1b, while there is enhanced cellular reactivity throughout the tissue, presumptively due to unmasking of intracellular, glycosylated Wnt7B. Methylene blue counterstain. Bar = 100 μm. Figure1e-f, Serial sections of UIP/IPF lung treated for the immunohistochemical localization of Wnt7B; the first (e) without and second (f) with the antigenic blocking peptide simultaneously with the Wnt7B-specific antibody. The two positive fibroblastic foci (FF) in (e) show diminished selective staining for Wnt7B in (f). Methylene blue counterstain. Bar = 100 μm.