Figure 5.

AREG promotes mucous cell differentiation and hyperplasia. (A): Fold-change in expression of mucous differentiation-related genes (see text for full gene names) in the epithelium derived from basal cells (BC) after 28 days of ALI culture in the presence of AREG versus untreated control (mean ± SD). (B): Cytopreps (top panels) and sections (remaining panels) of ALI samples derived from BC as described in A analyzed using immunohistochemistry for MUC5AC (see Supporting Information Fig. S5A for more examples) or Alcian blue staining (blue–mucus); scale bars-20 µm (representative of three experiments). (C): Quantification of MUC5AC-expressing cells in samples described in B (relative to the AREG group; mean±SD). (D): % Alcian blue-positive cells in AREG versus control groups described in B (mean ± SD; n = 3 experiments); arrows show Alcian blue-positive cells. (E): Fold-change in expression of indicated mucous differentiation-related genes in the epithelium derived from BC during 14 days of ALI in the presence of neutralizing anti-AREG antibody versus goat IgG control (mean±SD). (F): Expression of indicated mucous-related genes in the epithelium derived from BC treated as described in Figure 4F; normalized to control IgG group (mean ± SD); see more data in Supporting Information Figure S5C. All panels represent data derived from ≥3 independent experiments. Abbreviations: AGR2, anterior gradient 2; AREG, amphiregulin; SPDEF, SAM pointed domain containing ETS transcription factor.