Differential expression and significance of complement C4b and transthyretin in proliferative vitreoretinopathy
ABSTRACT To investigate the differential expression of complement C4b and transthyretin in proliferative vitreoretinopathy (PVR).
It was a controlled experimental study. Human vitreous samples of 5 patients with PVR were analyzed by using two-dimensional gel electrophoresis and mass spectrometry, and the results were compared with those from normal control vitreous obtained from donor eyes. An in vivo model of PVR was created by intravitreous injection of cultured rabbit retinal pigment epithelial (RPE) cells. The vitreous of PVR models were analyzed by enzyme linked immunosorbent assay (ELISA) to confirm the proteomic results from the PVR patients.
Seventy nine various proteins were expressed differently between PVR and normal vitreous, among which nine up-regulated proteins including complement C4b, transthyretin (TTR), and 7 albumins were identified by mass spectrometry. The up-regulation of complement C4b and TTR in PVR patients was also confirmed by ELISA. The concentration of complement C4b and TTR in normal vitreous were (20.18 ± 1.97) mg/L and (88.58 ± 8.84) mg/L respectively, in PVR patients were (38.1 ± 5.79) mg/L and (112.57 ± 6.89) mg/L respectively, difference significantly between these two groups (C4b: t = 11.54, TTR:t = 9.24; P < 0.05).
Differences of complement C4b and TTR expression were observed between PVR and normal vitreous. These results have lead to the assumption that there is a connection between elevated concentrations of both complement C4b and TTR and the pathogenesis of PVR and further studies on the functions of these proteins are required.
- SourceAvailable from: Luis António Passarinha[Show abstract] [Hide abstract]
ABSTRACT: The vitreous humor (VH) is the largest component of the eye. It is a colorless, gelatinous, highly hydrated matrix that fills the posterior segment of the eye between the lens and the retina in vertebrates. In VH, a diversity of proteins that can influence retinal physiology is present, including growth factors, hormones, proteins with transporter activity, and enzymes. More importantly, the protein composition of VH has been described as being altered in a number of disease states. Therefore, attempts aiming at establishing a map of VH proteins and detecting putative biomarkers for ocular illness or protein fluctuations with putative physiologic significance were conducted over the last two decades, using proteomic approaches. Proteomic strategies often involve gel-based or liquid-chromatography techniques as sample fractioning approaches, subsequently coupled with mass spectrometry procedures. This set of studies resulted in the proteomic characterization of a range of ocular disease samples, with particular incidence on diabetic retinopathy. However, practical therapeutic applications arising from these studies are scarce at the moment. A pertinent example of therapeutic targets arising from VH proteomics has emerged concerning vasoproliferative factors present in the vitreous, which should be involved in neovascularization and subsequent fibrovascular proliferation of the retina, in ocular disease context. Therefore, this review attempts to sum up the information acquired from the proteomic approaches to ocular disease conducted in VH samples, highlighting its clinical potential for disclosing ocular disease mechanisms and engendering pharmacological therapeutic treatments. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.PROTEOMICS - CLINICAL APPLICATIONS 02/2015; 9(1-2). DOI:10.1002/prca.201400133 · 2.68 Impact Factor