title: Shotgun proteomics reveals specific modulated protein patterns in tears of patients with primary open angle glaucoma naïve to therapy.
abstract: Primary open angle glaucoma (POAG) is one of the main causes of irreversible blindness worldwide. The pathogenesis of POAG is still unclear. Alteration and sclerosis of trabecular meshwork with changes in aqueous humor molecular composition seem to play the key role. Increased intraocular pressure is widely known to be the main risk factor for the onset and progression of the disease. Unfortunately, the early diagnosis of POAG still remains the main challenge. In order to provide insight into the patho-physiology of glaucoma, here we report a shotgun proteomics approach to tears of patients with POAG naïve to therapy. Our proteomics results showed 27 differential tear proteins in POAG vs. CTRL comparison (25 up regulated proteins in the POAG group and two unique proteins in the CTRL group), 16 of which were associated with inflammatory response, free radical scavenging, cell-to-cell signaling and interaction. Overall the protein modulation shown in POAG tears proves the involvement of biochemical networks linked to inflammation. Among all regulated proteins, a sub-group of 12 up-regulated proteins in naïve POAG patients were found to be down-regulated in medically controlled POAG patients treated with prostanoid analogues (PGA), as reported in our previous work (i.e., lipocalin-1, lysozyme C, lactotransferrin, proline-rich-protein 4, prolactin-inducible protein, zinc-alpha-2-glycoprotein, polymeric immunoglobulin receptor, cystatin S, Ig kappa chain C region, Ig alpha-2 chain C region, immunoglobulin J chain, Ig alpha-1 chain C region). In summary, our findings indicate that the POAG tears protein expression is a mixture of increased inflammatory proteins that could be potential biomarkers of the disease, and their regulation may be involved in the mechanism by which PGA are able to decrease the intraocular pressure in glaucoma patients.
authors.affiliation: Department of Experimental and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Via dei Vestini, 66100 Chieti, Italy. dpieragostino@unich.it
authors.forename: Damiana
authors.initials: D
authors.lastname: Pieragostino
authors.forename: Luca
authors.initials: L
authors.lastname: Agnifili
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Fasanella
authors.forename: Simona
authors.initials: S
authors.lastname: D'Aguanno
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Mastropasqua
authors.forename: Carmine
authors.initials: C
authors.lastname: Di Ilio
authors.forename: Paolo
authors.initials: P
authors.lastname: Sacchetta
authors.forename: Andrea
authors.initials: A
authors.lastname: Urbani
authors.forename: Piero
authors.initials: P
authors.lastname: Del Boccio
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D005136:Eye Proteins / Q000032:analysis*; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism*; D006801:Humans; D007249:Inflammation; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D011453:Prostaglandins / Q000627:therapeutic use; D011465:Prostaglandins, Synthetic / Q000627:therapeutic use; D040901:Proteomics / Q000379:methods; D013666:Tears / Q000737:chemistry*; D014129:Trabecular Meshwork / Q000378:metabolism
chemical_list: D015415:Biomarkers; D005136:Eye Proteins; D011453:Prostaglandins; D011465:Prostaglandins, Synthetic; C042434:tear proteins