Catalogue of soluble proteins in human vitreous humor by one-dimensional sodium dodecyl sulfate–polyacrylamide gel electrophoresis and electrospray ionization mass spectrometry including seven angiogenesis-regulating factors

A catalogue of proteins in the human vitreous humor may contribute to elucidating the pathogenesis of various diseases in ophthalmology. To improve the recovery of proteins in vitreous, we applied one-dimensional sodium dodecyl sulfate–polyacrylamide gel electrophoresis (1D-PAGE). Proteins were extracted from unstained gel strips and digested in gel with trypsin and the peptides were analyzed by capillary-column reversed-phase high-performance liquid chromatography coupled with electrospray ionization-ion trap-mass spectrometry. From a patient with diabetic retinopathy, 84 different proteins were identified. Most of the proteins which we identified in vitreous previously using 2D-PAGE were also identified in the present study. In total, we identified 121 different proteins including five proteins seen at the genomic level only. Four angiogenic factors, insulin-like growth factor, vascular endothelial growth factor, fibroblast growth factor, and placental endothelial cell growth factor, and three anti-angiogenic factors, pigment epithelium-derived factor, endostatin, and thrombospondin, were found, and this may contribute to elucidating the pathological changes in the concentration and the modified structures of these proteins, in diseases of the retina, especially, diabetic retinopathy.