Purpose: To isolate and characterize goblet cells from normal human conjunctival tissue to determine whether epidermal growth factor (EGF) receptors are present and whether EGF can influence goblet cell proliferation.
Methods: Goblet cells were isolated from explant cultures established from normal conjunctival tissue harvested from patients during periocular surgery. The cells were grown in RPMI culture medium supplemented with 10% fetal bovine serum and characterized using morphology, histochemistry, indirect immunofluorescence microscopy, molecular biology, and biochemistry. Proliferation was determined with a MTT proliferation assay after exposing goblet cells, which had been serum deprived for 48 hours, to increasing concentrations of epidermal growth factor (EGF; 0-80 ng/mL) for 24 hours.
Results: Goblet cells were isolated from conjunctival explants by scraping nongoblet cells from the culture dish. Human goblet cells exhibited positive reactivity with alcian blue-periodic acid Schiff (PAS) reagent, goblet cell-specific cytokeratin-7, HPA lectin, and MUC5AC, but negative reactivity to the stratified squamous epithelial cell marker, cytokeratin-4. The mRNA for MUC5AC was detected using RT-PCR. The presence of the EGF receptors EGFR, ErbB2, and ErbB3 was confirmed through Western blot analysis of cell lysates. EGF elicited a concentration-dependent increase in goblet cell proliferation of 160% +/- 0.5%, 188% +/- 0.45%, 293% +/- 1.3%, and 220% +/- 0.5% of control values with 10, 20, 40, and 80 ng/mL EGF, respectively.
Conclusions: Human goblet cells that retain characteristics of goblet cells in vivo can be cultured. EGF receptors are present in human goblet cells, and EGF stimulates their proliferation.