0000000000083436
AUTHOR
Sebastian Funke
Alterations in the tear proteome of dry eye patients--a matter of the clinical phenotype.
PURPOSE. Previous studies demonstrated alterations in the tear proteome of dry eye patients. The aim of the present study was to analyze tear protein patterns of dry eye patients considering different clinical phenotypes in order to examine their influence on tear film protein composition. METHODS. We applied a surface-enhanced laser desorption/ ionization-time-of-flight (SELDI-TOF)/matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF)/TOF mass spectrometry (MS)‐based strategy to detect/identify candidate biomarkers. Tear samples of 169 patients, enrolled in two independent studies, were analyzed. Patients were subdivided into healthy controls (CTRL: N ¼ 39), aqueous-defici…
Correlation of Crystallin Expression and RGC Susceptibility in Experimental Glaucoma Rats of Different Ages.
Glaucoma is one of the leading causes of blindness worldwide with age being an important risk factor. However, the pathogenesis remains poorly understood. Aim of this study was to focus on age-dependent molecular changes in an experimental animal model of glaucoma.Intraocular pressure was elevated in Sprague-Dawley rats aged 3, 14, and 47 weeks for a period of 7 weeks by episcleral vein cauterization. Ganglion cell loss was monitored by an immunohistochemical staining of the Brain-specific homeobox/POU (Pit-1, Oct-2, Unc-86) domain protein 3A positive cells in retinal flat-mounts and spectral-domain optical coherence tomography measuring the retinal nerve fiber layer thickness. Molecular pr…
Proteomics Differentiate Between Thyroid-Associated Orbitopathy and Dry Eye Syndrome.
PURPOSE: In patients with thyroid-associated orbitopathy (TAO), the dry eye syndrome occurs frequently, and symptoms and signs of both disorders overlap making early and accurate differential diagnosis difficult. A differentiation via specific markers is warranted. METHODS: Tear fluid samples of 120 subjects with TAO, TAO + dry eye, dry eye, and controls were collected. The samples were measured using matrix-assisted laser desorption ionization mass spectrometry. The identified proteins were tested with antibody microarrays. RESULTS: Proteomics identified deregulated proteins in TAO and dry eye. Compared with dry eye, proline-rich protein 1 (PROL1, P = 0.002); uridine diphosphate (UDP)-gluc…
Proteome alterations in aqueous humour of primary open angle glaucoma patients.
Aim To unravel the primary open angle glaucoma (POAG) related proteomic changes in aqueous humour (AH). Methods Totally 35 patients listed for cataract surgery (controls: n=12, age: 67.4±13.6y) or trabeculectomy for POAG (n=23, age: 72.5±8.3y) were included. AH samples of those patients were obtained during cataract surgery or trabeculectomy. AH samples were subsequently pooled into the experimental groups under equal contribution in terms of protein amount of each individual patient. Protein samples were analyzed by a linear trap quadrupol Orbitrap Mass Spectrometry device with an upstream liquid chromatography system. The obtained raw data were analyzed using the Maxquant proteome softwar…
Does autoimmunity play a part in the pathogenesis of glaucoma?
Glaucoma is a chronic neurodegenerative disease and one of the leading causes of blindness. Several risk factors have been described, e.g. an elevated intraocular pressure (IOP), oxidative stress or mitochondrial dysfunction. Additionally, alterations in serum antibody profiles of glaucoma patients, upregulation (e.g. anti-HSP60, anti-MBP) and downregulation (e.g. anti-14-3-3), have been described, but it still remains elusive if the autoantibodies seen in glaucoma are an epiphenomenon or causative. However, it is known that elicited autoimmunity causes retinal ganglion cell loss resulting in glaucomatous-like damage and according to the autoaggressive nature of some autoantibodies we found…
The evolutionary history of the rediscovered Austrian population of the giant centipede Scolopendra cingulata Latreille 1829 (Chilopoda, Scolopendromorpha).
The thermophilous giant centipede Scolopendra cingulata is a voracious terrestrial predator, which uses its modified first leg pair and potent venom to capture prey. The highly variable species is the most common of the genus in Europe, occurring from Portugal in the west to Iran in the east. The northernmost occurrences are in Hungary and Romania, where it abides in small isolated fringe populations. We report the rediscovery of an isolated Austrian population of Scolopendra cingulata with the first explicit specimen records for more than 80 years and provide insights into the evolutionary history of the northernmost populations utilizing fragments of two mitochondrial genes, COI and 16S, …
Longitudinal analysis of taurine induced effects on the tear proteome of contact lens wearers and dry eye patients using a RP-RP-Capillary-HPLC-MALDI TOF/TOF MS approach.
Tear proteomic studies revealed distinct similarities between contact lens wearers and dry eye patients. AMO Complete® multipurpose contact lens cleaning solutions containing taurine seem to have a beneficial effect regarding contact lens induced dry eye. To illuminate the effect of taurine on the tear proteome of contact lens wearers and sicca patients we developed a gel-based RP-RP capillary HPLC-MALDI TOF/TOF MS strategy. Two contact lens wearer groups, one using eye drops containing 0.05% taurine; the other for control physiological NaCl solution were monitored. Also, a third group of sicca patients using taurine solution was studied (N=4 individuals/group). Tear pools of each group at …
Characterization of human reflex tear proteome reveals high expression of lacrimal proline-rich protein 4 (PRR4).
In-depth studies on the proteome of reflex tears are still inadequate. Hence, further studies on this subject will unravel the key proteins which are conjectured to possess vital functions in the protection of the ocular surface. Therefore, this study investigated the differences in the expression levels in proteome of reflex compared to basal tears. Basal (n = 10) and reflex (n = 10) tear samples from healthy subjects were collected employing the capillary method, subsequently pooled and the proteomes were characterized employing 1DE combined with LC-ESI-MS/MS strategy for label-free quantitative (LFQ) analysis. The differentially expressed proteins were validated by 2DE combined with LC-E…
Comparison of Two Solid-Phase Extraction (SPE) Methods for the Identification and Quantification of Porcine Retinal Protein Markers by LC-MS/MS
Proper sample preparation protocols represent a critical step for liquid chromatography-mass spectrometry (LC-MS)-based proteomic study designs and influence the speed, performance and automation of high-throughput data acquisition. The main objective of this study was to compare two commercial solid-phase extraction (SPE)-based sample preparation protocols (comprising SOLAµ
Serum and antibodies of glaucoma patients lead to changes in the proteome, especially cell regulatory proteins, in retinal cells.
PURPOSE: Previous studies show significantly specifically changed autoantibody reactions against retinal antigens in the serum of glaucoma and ocular hypertension (OHT) patients in comparison to healthy people. As pathogenesis of glaucoma still is unknown the aim of this study was to analyze if the serum and antibodies of glaucoma patients interact with neuroretinal cells. METHODS: R28 cells were incubated with serum of patients suffering from primary open angle glaucoma (POAG), normal tension glaucoma (NTG) or OHT, POAG serum after antibody removal and serum from healthy people for 48 h under a normal or an elevated pressure of 15000 Pa (112 mmHg). RGC5 cells were additionally incubated wi…
Tears as a source of biomarkers for ocular and systemic diseases
The main focus in clinical proteomics is the discovery of new protein or peptide biomarkers which are correlated with a certain disease. Tear proteins have been investigated extensively in the past and distinct relations between the levels of certain tear proteins to different disorders have been demonstrated. In this review we attempt to summarize proteomic technologies for biomarker identification in tears and some disease related biomarkers in tear fluids that were discovered through different proteomic techniques in different conditions like dry eye, Sjogren's syndrome, contact lens wearers, glaucoma, diabetic retinopathy or cancer. Proteomic analysis of tear fluid has proven to be a pr…
Peptides of the variable IgG domain as potential biomarker candidates in primary open-angle glaucoma (POAG)
Autoantibody profiling has gained increasing interest in the research field of glaucoma promising the detection of highly specific and sensitive marker candidates for future diagnostic purposes. Recent studies demonstrated that immune responses are characterized by the expression of congruent or similar complementarity determining regions (CDR) in different individuals and could be used as molecular targets in biomarker discovery. Main objective of this study was to characterize glaucoma-specific peptides from the variable region of sera-derived immunoglobulins using liquid chromatography--mass spectrometry (LC-MS)-based quantitative proteomics. IgG was purified from sera of 13 primary open…
Comparative Quantitative Analysis of Porcine Optic Nerve Head and Retina Subproteomes
Optic nerve head (ONH) and retina (RET) are the main sites of damage in neurodegenerative optic neuropathies including glaucoma. Up to date, little is known about the molecular interplay between these two adjoining ocular components in terms of proteomics. To close this gap, we investigated ONH and RET protein extracts derived from porcine eyes (n = 12) (Sus scrofa domestica Linnaeus 1758) using semi-quantitative mass spectrometry (MS)-based proteomics comprising bottom-up LC&ndash
Biomarker sources for Parkinson's disease: Time to shed tears?
Abstract Parkinson's disease (PD) is the most frequent neurodegenerative movement disorder. In nearby future its importance will increase, especially due to changes in age structure. There are still substantial problems in terms of early diagnosis of the disease. In clinical practice, the diagnosis of PD is still based on the evaluation of clinical presentation and is supported by various ancillary tests with heterogeneous predictive value. In regard to diagnosis and disease monitoring, body fluid-based biomarkers have become an indispensable tool in today's medicine. In this Current Opinion we briefly address the present approaches to biomarker development for PD, including clinical trials…
Neuroprotective effects of antibodies on retinal ganglion cells in an adolescent retina organ culture
Glaucoma, a neurodegenerative disease, is characterized by a progressive loss of retinal ganglion cells (rgc). Up- and down-regulated autoantibody immunoreactivities in glaucoma patients have been demonstrated. Previous studies showed protective effects of down-regulated antibodies [gamma (γ)-synuclein and glial fibrillary acidic protein [GFAP]) on neuroretinal cells. The aim of this study was to test these protective antibody effects on rgc in an organ culture model and to get a better understanding of cell-cell interactions of the retina in the context of the protective effect. We used an adolescent retinal organ culture (pig) with an incubation time of up to 4 days. Retinal explants were…
Characterization of lacrimal proline-rich protein 4 (PRR4) in human tear proteome
This study was initiated considering the lack of comprehensive characteristics profile of PRR4 in tears of healthy subjects. Therefore, detailed characterizations of PRR4 from basal tears employing in-gel and in-solution digestions for MS systems are presented herein. First, pooled tear samples (n = 10) were utilized to identify PRR4-rich region/spots in 1DE/2DE gels employing LC-MALDI-MS and 1DE-LC-ESI-LTQ-Orbitrap-MS systems. PRR4-rich region and ten spots with vast polymorphisms (Mr : 17-30 kDa, pI: 3.0-6.6) were identified in 1DE and 2DE gels, respectively. In addition, combinations of four types of PTMs, which are methylation, acetylation, oxidation, and pyroglutamate formation, were i…