N. Yanagihara et al., Hepatocyte growth factor promotes epithelial morphogenesis and occludin linkage to the cytoskeleton in cultured retinal pigment epithelial cells, GR ARCH CL, 239(8), 2001, pp. 619-627
Citations number
42
Categorie Soggetti
Optalmology
Journal title
GRAEFES ARCHIVE FOR CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
Background: Although hepatocyte growth factor (HGF) is also known as scatte
r factor, it induces epithelial morphogenesis in cultured bovine retinal pi
gment epithelial (RPE) cells. To elucidate the mechanism of epithelial morp
hogenesis, we investigated the influence of HGF on occludin, a major compon
ent of tight junctions. Methods: RPE cells were plated on collagen type 1-c
oated chamber slides or dishes, 20 ng/ml HGF was added and the cells were i
ncubated for 1 week. Cells were harvested at several time-points, and occlu
din expression was examined by immunohistochemistry. Detergent extraction p
rotocols to identify the intensity of occludin linkage to the cytoskeleton
were also used. Occludin expression was determined semiquantitatively by We
stern blotting. Results: Fluorescence microscopy revealed that HGF treatmen
t increased the levels of insoluble occludin at the cell borders after dete
rgent extraction. These level of insoluble occludin and the associated epit
helial morphology were maintained for more than 3 weeks after withdrawal of
HGF, whereas cells not treated with HGF had a fibroblastic appearance. Wes
tern blotting also showed that insoluble occludin was more abundant in HGF-
treated cells. Furthermore, immunoreactive bands of insoluble occludin were
somewhat larger than those of soluble occludin, suggesting that insoluble
occludin may be modified in comparison to soluble occludin. Conclusion: Our
results suggest that HGF promotes linkage of occludin to the cytoskeleton.
HGF may become a therapeutic candidate in physiological recovery of RPE ce
lls and in preparation of RPE monolayers for transplantation.