Figure 2. KLF4 knockdown alters esophageal stratification via WNT5A.

(A) In three-dimensional organotypic culture, primary human esophageal keratinocytes form stratified epithelia. Cells in the basal layer were rounded with large nuclear-cytoplasmic ratios, and cells in the suprabasal and superficial layers were flattened with compacted nuclei. (B,C) In contrast, KLF4 knockdown in primary human esophageal keratinocytes in organotypic culture yielded epithelia that were hyperplastic, and cells appeared less mature, with cells outside of the basal layer maintaining a rounded appearance and large nuclei. (D–F) Treatment of the cultures with recombinant WNT5A had little effect on control epithelia (D) but restored normal epithelial stratification of primary esophageal keratinocytes with inducible KLF4 knockdown (E,F). Scale bars, 50 μm.