The effect of nerve growth factor on proliferation and expression of mucin gene in human conjunctival goblet cells

Abstract

To study the effect of nerve growth factor (NGF) on the proliferation and the expression of MUC5AC gene in cultured human conjunctival goblet cells. The presence of high affinity receptors of nerve growth factor (TrkA) in cultured human conjunctival goblet cells was identified with immunocytochemical analysis. Proliferation of goblet cells was determined by MTT proliferation assay after exposure to different concentrations of NGF, (20, 40, 60 and 80 ng/ml) in serum-free RPMI-1640 culture medium (RPMI) for 1, 3 and 5 days. The effect of NGF on gene expression of MUC5AC of goblet cells was determined by RT-PCR after exposing cells to NGF (80 ng/ml in serum-free RPMI) for 5 days. Human conjunctival goblet cells in subculture exhibited positive staining for TrkA. After exposure to NGF, the differences in absorption value of MTT test of goblet cells cultured with different levels of NGF (F = 12.766, P = 0.000) and at different time points (F = 892.406, P = 0.000) were statistically significant, but the difference in interaction effects was not significant. MUC5AC gene expression of NGF group was higher than that of the control group (t = 4.963, P = 0.000). NGF receptors (TrkA) are present in human conjunctival goblet cells. NGF causes a dose-dependent increase in the proliferation of goblet cells. The expression of MUC5AC gene in goblet cells is upgraded by NGF.