title: Proteomic analysis of aqueous humor from patients with primary open angle glaucoma.
abstract: OBJECTIVE
  Primary open angle glaucoma (POAG) is a leading cause of irreversible blindness on a global level. Researchers have yet to specify the exact mechanisms of POAG; the respective relationships between POAG and elevated intraocular pressure (IOP), as well as optic neuropathy, remain particularly unclear. It is known, however, that the expression profile for some proteins in the aqueous humor (AH) changes in some diseases, and that AH changes play important roles in elevated IOP. To identify the possible roles of these AH proteins in POAG, a proteomic analysis of the AH compositions of POAG patients' eyes was performed and compared with those derived from paired, non-POAG cataract (control) eyes.
  
  
  METHODS
  We used Bradford's method to determine total protein concentration in AH, and analyzed separation profiles via two-dimensional (2D) gel electrophoresis. We used silver stain to determine gel proteins, and analyzed separation profiles to assess spot density differences between POAG and non-POAG patients. These gel spots were isolated and identified via mass spectrometry. Prostaglandin H2 D-isomerase (PGDS) in AH were analyzed by western Blotting.
  
  
  RESULTS
  There was no significant difference between the total protein concentration in AH of POAG patients and that in AH of non-POAG patients. A total of seven spots were increased in 2D gels from POAG patients. The spots were derived from PGDS, caspase 14 precursor, transthyretin, cystain C, albumin precursor, and tranferrin. And PGDS in AH from patients was more than from controls.
  
  
  CONCLUSIONS
  The protein composition in AH was significantly different in POAG patients versus non-POAG patients. The identified proteins could be a potential biomarker for POAG and may play a role in the mechanisms of elevated IOP and optic neuropathy in POAG.
authors.affiliation: Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Duan
authors.forename: Peng
authors.initials: P
authors.lastname: Xue
authors.forename: Ningli
authors.initials: N
authors.lastname: Wang
authors.forename: Zhe
authors.initials: Z
authors.lastname: Dong
authors.forename: Qingjun
authors.initials: Q
authors.lastname: Lu
authors.forename: Fuquan
authors.initials: F
authors.lastname: Yang
mesh_terms: D000328:Adult; D001082:Aqueous Humor / Q000378:metabolism*; D015153:Blotting, Western; D016022:Case-Control Studies; D015180:Electrophoresis, Gel, Two-Dimensional; D005136:Eye Proteins / Q000737:chemistry / Q000378:metabolism; D005260:Female; D005902:Glaucoma, Open-Angle / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000737:chemistry / Q000378:metabolism; D054834:Lipocalins / Q000737:chemistry / Q000378:metabolism; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D040901:Proteomics / Q000379:methods*; D016622:Silver Staining
chemical_list: D005136:Eye Proteins; D054834:Lipocalins; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase