Abstract
Purpose :
Müller glia with stem cell characteristics are responsible for the spontaneous regeneration of the zebrafish retina after injury. These cells are also present in the human retina, however there is no evidence for regeneration. It is thought that factors either expressed in the mature human retina or produced as a result of injury, may prevent endogenous regeneration in humans. To identify these factors, this study compared the protein expression profile of normal and gliotic human retina with that of the degenerated and regenerating zebrafish retina
Methods :
Retinal samples were obtained from patients undergoing retinectomy for PVR in accordance with the tenets of the Declaration of Helsinki. Normal cadaveric retina was obtained from Moorfields Eye Bank by approval of the local Ethics Committee. Zebrafish eyes were injected with 200μM Ouabain, and retina was excised at days 3 and 18 post injection. The use of animals was in accordance with the U.K. Home Office regulations for the use of laboratory animals. Differential protein profile expression was performed on retinal lysates using Label-free proteomics by LC-MS/MS and 2D DIGE methods. Protein identification and bioinformatics were performed using Protein Lynx Global Server (PLGS), and Non-Linear dynamics Progenesis software
Results :
Mass spectrometry identified 473 proteins in the human retina and 328 proteins in the zebrafish retina. Orthological protein comparison showed that 80 proteins were present in both zebrafish and human retinae. Of these proteins, 6 were upregulated >2-fold in the gliotic human retina, but only one, identified as galectin, was upregulated >2-fold in the degenerated zebrafish retina. In addition, 36 of these 80 proteins were <0.5-fold downregulated in the gliotic human retina, whilst 26 were also downregulated in the degenerated zebrafish retina. Only one protein, known as adenylate kinase, was upregulated >2-fold in the degenerated zebrafish retina. Many protein changes observed in both species were associated with heat shock proteins, histones and the extracellular matrix
Conclusions :
This proteomic-based study has identified differences in the protein expression profile of the degenerated human and zebrafish retinae. Further investigations of the role of differentially expressed proteins in both species during retinal degeneration may help to design novel approaches to promote endogenous repair mechanisms in the human retina
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.