Differentiation of vitreous proteome in human eye with proliferative Vitreoretinopathy

Abstract

Background Proliferative vitreoretinopathy (PVR) is a a common cause of anatomic failure in retinal detachment surgery.Proteomics is the critical method to investigate the different proteins. Objective This study was to search for related vitreous proteins in rhegmatogenous retinal detachment patients with proliferative vitreoretinopathy (PVR)and screen for the related protein expression in the vitreous with PVR. Methods Vitreous samples were obtained from 8 moderate PVR (grade B)eyes and 8 severe PVR(grade C or D)eyes during pars plana vitrectomy (PPV)for the proteomics analysis by two-dimensional gel electrophoresis coupled with mass spectrometry.Normal vitreous from 8 healthy donor eyes served as control.First dimension isoelectric focusing (IEF) was performed with the Pharmacia IPGphor in solvent B using 18 cm non-linear pH 3-10 immobilized pH gradient (IPG)strips.IPG strips were rehydrated with sample,and then IEF was performed.The second dimension 12%sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE) was performed after the IPG strips were equilibrated.After silver staining,the gels were analyzed by the 2-DE gel analysis software.The matched spots were excised and tryptica digested in-gel.The peptides were analyzed by MALDI-TOF-MS and the MS/MS spectral were searched against the human protein databases using MASCOT.This study process complied with the Declaration of Helsinki.Wfitten informed consent was obtained from each patient prior to this trial. Results In the current study,a total of 47,184 and 336 protein spots were detected from the normal donor eyes,moderate PVR eyes and severe PVR eyes,respectively,by 2-DE gels.Among 13 protein spots with significant differences in the 3 groups,7 types of proteins were successfully identified.The results indicated that Enolase 2 was a specific protein for normal donor vitreous.whereas transthyretin monomer and retinol-binding protein(RBP) chain B were distinct proteins found in severe PVR vitreous.and prostaglandin D synthase and RBP3 precursor were common proteins with up-regulated expression in vitreous samples with moderate PVR,but down-regulated levels in vitreous samples with severe PVR.The levels of albumin and transferrin in vitreous showed dynamic elevation with the enhancement of severity of PVR.Conclusion The changes in the vitreous proteome imply that some types of vitreous proteins degrade and some common serum proteins are expressed in the vitreous body with PVR,which indicated the disruption of the blood retinal barrier in the pathogenesis of PVR. Key words: Proteome; Proliferative vitreoretinopathy; Vitreous