Tear proteomics in evaporative dry eye disease

• Published in: Eye (London) Vol. 24; no. 8; pp. 1396 - 1402
• Main Authors: Versura, P, Nanni, P, Bavelloni, A, Blalock, W L, Piazzi, M, Roda, A, Campos, E C
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.08.2010; Nature Publishing Group
• Subjects: 631/45/475; Adult; Aged; Albumins - analysis; Biological and medical sciences; Carrier Proteins - analysis; Case-Control Studies; Dry Eye Syndromes; Electrophoresis, Polyacrylamide Gel; Eye Proteins - analysis; Eye Proteins - genetics; Female; Glycoproteins - analysis; Humans; Laboratory Medicine; laboratory-study; Lactoferrin - analysis; Lipocalins - analysis; Lipocalins - genetics; Male; Medical sciences; Medicine; Medicine & Public Health; Middle Aged; Miscellaneous; Muramidase - analysis; Myelin Proteins - analysis; Myelin Proteins - genetics; Ophthalmology; Pharmaceutical Sciences/Technology; Proteolipids - analysis; Proteolipids - genetics; Proteomics; Secretoglobins; Surgery; Surgical Oncology; Tears - chemistry; Uteroglobin - analysis; Uteroglobin - genetics; mass spectrometry; western-blot; dry eye disease; proteomics; electrophoresis; human tears; Human; Tear; Exploration; Dry eye syndrome; Eye disease; Dry eye; Proteomics; Immunoblotting assay; Electrophoresis; Ophthalmology; Mass spectrometry
• ISSN: 0950-222X; 1476-5454; 1476-5454
• DOI: 10.1038/eye.2010.7

Purpose: To analyze tear protein variations in patients suffering from dry eye symptoms in the presence of tear film instability but without epithelial defects. Methods: Five microlitres of non-stimulated tears from 60 patients, suffering from evaporative dry eye (EDE) with a break-up time (BUT) <10 s, and from 30 healthy subjects as control (no symptoms, BUT >10 s) were collected. Tear proteins were separated by mono and bi-dimensional SDS-PAGE electrophoresis and characterized by immunoblotting and enzymatic digestion. Digested peptides were analyzed by liquid chromatography coupled to electrospray ionization quadrupole-time of flight mass spectrometry followed by comparative data analysis into Swiss-Prot human protein database using Mascot. Statistical analysis were performed by applying a t -test for independent data and a Mann–Whitney test for unpaired data ( P <0.05). Results: In EDE patients vs controls, a significant decrease in levels of lactoferrin (data in %±SD): 20.15±2.64 vs 24.56±3.46 ( P =0.001), lipocalin-1: 14.98±2.70 vs 17.73±2.96 ( P =0.0001), and lipophilin A–C: 2.89±1.06 vs 3.63±1.37 ( P =0.006) was revealed, while a significant increase was observed for serum albumin: 9.45±1.87 vs 3.46±1.87 ( P =0.0001). No changes for lysozyme and zinc α-2 glycoprotein ( P =0.07 and 0.7, respectively) were shown. Proteomic analysis showed a downregulation of lipophilin A and C and lipocalin-1 in patients, which is suggested to be associated with post-translational modifications. Conclusions: Data show that tear protein changes anticipate the onset of more extensive clinical signs in early stage dry eye disease.