Abstract
Purpose: :
Proteomic technologies such as protein microarrays, multiplexed immunohistochemistry, 2D gel electrophoresis, and mass spectrometry have proven useful for deciphering the unique proteome of many biologic materials including serum and cerebrospinal fluid. Vitreous proteins are less abundant than in serum and tissue lysates and therefore will require the development more sensitive analytical techniques. This presentation provides the first data on the spectrum of proteins composing the vitreous and retinal proteome that can be detected and studied in small aspirates from human eyes.
Methods: :
Human vitreous was obtained under patient consent and IRB approval. Each patient sample was divided into four separate aliquots, and each aliquot independently analyzed. The vitreous fluid was subjected to complete trypsin enzymatic digestion followed by cationic and reverse phase chromatographic fractionation. Each fraction was analyzed by LTQ–ESI nano–flow electrospray mass spectrometry (ThermoElectron, Boston, MA) and protein assignment given based on repetitive and multiple peptide identifications.
Results: :
Analysis of the vitreous samples revealed 664 specific proteins. Of these, 226 were found in more than one sample. Included in these proteins are heat shock proteins, brain creatine kinase, and prostaglandin D2 synthase that can reflect retinal status in response to disease and treatment. An array of growth factors and/or receptors were identified including epithelial cell growth factor, insulin–like growth factor, insulin–like growth factor binding protein, vascular endothelial growth factor, wnt inhibitory factor, and others that have the potential of advancing our understanding, monitoring and treatment of ocular proliferation.
Conclusions: :
This is the first report using techniques of advanced proteomics to characterize the hundreds of proteins in human vitreous. Large, multi–center investigations and trials will be needed to reach the full potential of these findings. However, a vastly more complete understanding of the molecular pathways regulating ocular disease holds the promise of revolutionizing clinical practice.
Keywords: proteomics • retina • age-related macular degeneration