Hepatocyte growth factor function and c-Met expression in human lens epithelial cells

PURPOSE. Hepatocyte growth factor (HGF) and its receptor c-met perform a mu ltitude of functions. However, despite the significant degree of study of H GF and c-met in numerous tissues and cell types, relatively few investigati ons have been performed on the lens. In the current study, therefore, the r ole of HGF and the receptor c-met in human lens epithelial cells was invest igated. METHODS. Anterior epithelium and capsular bags were prepared from human don or eyes and maintained in Eagle's minimum essential medium (EMEM) in a 5% C O2 atmosphere at 35 degreesC. In addition, the human lens cell line FHL124, was routinely cultured and seeded onto glass coverslips (c-met immunodetec tion), 12-well plates (DNA and protein synthesis), and tissue culture dishe s (migration). c-Met was detected by immunocytochemistry and fluorescence-a ctivated cell scanning (FACS). HGF was measured using enzyme-linked immunos orbent assay (ELISA) techniques. Proliferation and protein synthesis were d etermined by [H-3]thymidine and S-35-methionine incorporation into DNA and proteins, respectively. Migration was assessed using a scratch-wound assay and time-lapse video microscopy. RESULTS. HGF was detected at all stages of culture of capsular bags in prot ein-free medium. Moreover, c-met was present on the native epithelium and a fter mechanical trauma was seen to be upregulated. Immunolocalization and F AGS analysis demonstrated c-met expression on FHL124 cells throughout the w hole population. Furthermore, FAGS analysis showed that serum-maintained ce lls sustained a higher level of receptor expression relative to serum-depri ved cells. Additionally, HGF was found to stimulate proliferation, protein synthesis, and migratory responses. CONCLUSIONS. c-Met receptors are expressed in native epithelium, capsular b ag cultures, and FHL124 cells. Receptor is distributed across the entire ce ll population; however, this expression is environmentally and mechanically sensitive. HGF is also present in capsular bags at all stages of culture. In addition, HGF can stimulate migration, proliferation, and protein synthe sis. It therefore appears that a multifunctional autocrine loop involving H GF and c-met is in place and could be important in the development of poste rior capsule opacification.