Pigment epithelium-derived factor is differentially expressed in peripheral neuropathies

Abstract

Peripheral neuropathies are characterized by asymmetrical slowly progressive weakness with no upper motor neuron signs, and can occur either with or without pain. Due to poor knowledge of the disease mechanisms, available pain treatment is very limited. Because of the difficulties and invasiveness involved when performing direct analysis on peripheral and CNS, pathological markers can be searched for in the cerebrospinal fluid (CSF) as an alternative. To investigate pain mechanisms in peripheral neuropathy and find diagnostic markers, CSF samples were analyzed by a differential expression proteomic approach. We studied CSF from: neuropathic patients with pain (PN), without pain (NPN) and healthy controls (CN). 2-DE analysis showed ten protein spots differentially expressed, and six of these were identified by MS. In NPN patients we found an expression level decrease of three pigment epithelium-derived factor (PEDF) protein isoforms. Immunoblot with a specific antibody revealed the presence of additional PEDF isoforms not highlighted by differential expression analysis. Fucose residues on the oligosaccharide chain were found only in the isoforms down regulated in NPN patients. Considered as PEDF has important neurobiological effects, it might be considered an interesting pathology marker.

Ceruloplasmin Oxidation, a Feature of Parkinson's Disease CSF, Inhibits Ferroxidase Activity and Promotes Cellular Iron Retention

“…Current criteria for the diagnosis of PD (Italian Neurological Society, 2003), of ALS (Brooks, 1994), and of AD (McKhann et al, 1984) were used for the admission of patients into the study. PN diagnosis was as described by Conti et al (2005). The Unified Parkinson's Disease Rating Scale (UPDRS) (Hoehn and Yahr, 1967;Fahn, 1987) was used to grade the disease.…”

“…The Unified Parkinson's Disease Rating Scale (UPDRS) (Hoehn and Yahr, 1967;Fahn, 1987) was used to grade the disease. ALS and PN samples were from aliquots collected for previous studies (Conti et al, 2005(Conti et al, , 2008, while CSF from AD patients derived from the Institute of Experimental Neuroscience Bio-Bank (Institute of Experimental Neuroscience, San Raffaele Scientific Institute). Exclusion criteria consisted of the following: HIV or HCV (hepatitis C virus) seropositivity, the appearance of other neurodegenerative diseases or previous cerebral ischemic events, and severe metabolic disorders (e.g., diabetes).…”

Molecular Cloning of hMena (ENAH) and Its Splice Variant hMena+11a: Epidermal Growth Factor Increases Their Expression and Stimulates hMena+11a Phosphorylation in Breast Cancer Cell Lines

“…Cells were washed, lyophilized, and proteins solubilized with two-dimensional electrophoresis buffer [9 mol/L urea, 10 mmol/L Tris, 4% CHAPS, 65 mmol/L DTT, 2% IPG buffer ampholine (pH 3-10), protease inhibitor cocktail]. Protein samples (250 Ag) were applied to 7-cm IPG strips pH 3-10 nonlinear (Amersham Biosciences) and isoelectrofocusing was done with an IPGphor system (Amersham Biosciences) following a standard protocol as described (25). Strips were equilibrated in 50 mmol/L Tris-HCl buffer (pH 8.8) containing 6 mol/L urea, 30% glycerol, 2% SDS, and 2% DTT, followed by an incubation in the same buffer replacing DTT with 2.5% iodoacetamide.…”

Comparative Proteomics for the Evaluation of Protein Expression and Modifications in Neurodegenerative Diseases

“…Neuropathies In a comparative proteomics study aimed to identify relevant molecules characterizing the peripheral neuropathies either with or without pain, we found in the CSF three spots corresponding to the same protein, namely pigment epithelium-derived factor (PEDF), that is reduced in the pathological conditions compared to healthy subjects (Conti et al, 2005).…”

“…5), that may reflect different functional roles (Conti et al, 2005). The different electrophoretic migration properties of the six isoforms can be explained by the heterogeneity of the several PTMs described for the PEDF, namely the generation of pyroglutamate (pGlu) at the aminoterminus of the mature PEDF when the signal peptide is removed, the presence of one heterogeneous glycosidic residue that can include or not sialylation and fucosylation, and the possible phosphorylation on three serine residues ( Fig.…”