Correlation of proliferative and anti-apoptotic effects of HGF, insulin, IGF-1, IGF-2, and EGF in SV40-transformed human corneal epithelial cells.
The effects of various growth factors on the proliferation and apoptosis of human corneal epithelial cells were investigated. Simian virus 40-transformed human corneal epithelial cells were thus incubated separately with eight different growth factors, after which cell proliferation was evaluated by measurement of [(3)H]thymidine incorporation or with the MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay and apoptosis was quantified by the terminal deoxyribonucleotidyl transferase-mediated dUTP-biotin nick-end labeling assay. Phosphorylation of the protein kinase Akt, which plays an important role in anti-apoptotic signaling, was also assessed by immunoblot analysis. The growth factors examined could be classified into three groups on the basis of their effects on the proliferation and apoptosis of human corneal epithelial cells: hepatocyte growth factor (HGF), insulin, insulin-like growth factor (IGF)-1, IGF-2, and epidermal growth factor (EGF) each increased cell proliferation, inhibited the induction of apoptosis by sodium nitroprusside, and elicited the activation of Akt; transforming growth factor-beta1 and -beta2 inhibited [3H]thymidine incorporation but had no effect on sodium nitroprusside-induced apoptosis or on Akt activity; and platelet-derived growth factor-BB had no effects on the measured parameters. HGF, insulin, IGF-1, IGF-2, and EGF may thus contribute to maintenance of the corneal epithelium and coordinate the proliferative and apoptotic responses of this tissue.
Yanai
Ryoji
R
Department of Biomolecular Recognition and Ophthalmology, Yamaguchi University School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan. yanai@yamaguchi-u.ac.jp
Yamada
Naoyuki
N
Inui
Makoto
M
Nishida
Teruo
T
D017209:Apoptosis / Q000502:physiology*; D002455:Cell Division / Q000502:physiology; D002461:Cell Line, Transformed; D004815:Epidermal Growth Factor / Q000502:physiology; D004847:Epithelial Cells / Q000502:physiology; D019573:Epithelium, Corneal / Q000502:physiology; D005136:Eye Proteins / Q000378:metabolism; D005347:Fibroblasts / Q000502:physiology; D017228:Hepatocyte Growth Factor / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000502:physiology*; D007334:Insulin-Like Growth Factor I / Q000502:physiology; D007335:Insulin-Like Growth Factor II / Q000502:physiology; D036341:Intercellular Signaling Peptides and Proteins / Q000502:physiology*; D009599:Nitroprusside; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011994:Recombinant Proteins; D015398:Signal Transduction / Q000502:physiology; D013539:Simian virus 40
D005136:Eye Proteins; D007328:Insulin; D036341:Intercellular Signaling Peptides and Proteins; D011994:Recombinant Proteins; D009599:Nitroprusside; D004815:Epidermal Growth Factor; D017228:Hepatocyte Growth Factor; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D051057:Proto-Oncogene Proteins c-akt