title: Two dimensional electrophoretic analysis of human tears: collection method in dry eye syndrome.
abstract: Tear proteomics, by 2-DE, can give a fingerprint of the protein profile, which is well suited in clinical proteomics for biomarker identification and in diagnostics. The mode of tear collection can influence the representation of the proteins in the tear and therefore it is important to use the appropriate method. In this study, capillary and Schirmer mode of tear collection was done in the healthy controls and the Schirmer method was validated in dry eye syndrome conditions. 2-D PAGE of normal and dry eye tear was performed using pH 3-10 linear IPG strips followed by 13% SDS-PAGE. The spot intensity was analyzed by the PD quest software. The two methods were compared using Bland-Altman statistical tool. The 2-D map of capillary and Schirmer tear showed 147 ± 8 spots and 145 ± 7 spots respectively. Both the collection methods were in agreement with each other and were comparable. Dry eye tear protein showed differential expression of proteins as observed in 25-35 kDa region. One of the significantly reduced protein was identified as proline-rich 4 protein. Schirmer method of tear collection is reliable in patients with dry eye, which can display the differential protein expression and help in biomarker identification.
authors.affiliation: Biochemistry and Cell Biology Department, Vision Research Foundation, Sankara Nethralaya, Chennai, India.
authors.forename: Aluru Venkata
authors.initials: AV
authors.lastname: Saijyothi
authors.forename: Narayanasamy
authors.initials: N
authors.lastname: Angayarkanni
authors.forename: Chandran
authors.initials: C
authors.lastname: Syama
authors.forename: Tatu
authors.initials: T
authors.lastname: Utpal
authors.forename: Agarwal
authors.initials: A
authors.lastname: Shweta
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Bhaskar
authors.forename: Iyer Krishnan
authors.initials: IK
authors.lastname: Geetha
authors.forename: Pillai S
authors.initials: PS
authors.lastname: Vinay
authors.forename: Maruthamuthu
authors.initials: M
authors.lastname: Thennarasu
authors.forename: Rajappa M
authors.initials: RM
authors.lastname: Sivakumar
authors.forename: Padmanabhan
authors.initials: P
authors.lastname: Prema
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000737:chemistry; D003627:Data Interpretation, Statistical; D015352:Dry Eye Syndromes / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010455:Peptides / Q000737:chemistry; D040901:Proteomics / Q000379:methods; D015203:Reproducibility of Results; D013048:Specimen Handling / Q000379:methods*; D053719:Tandem Mass Spectrometry; D013666:Tears / Q000737:chemistry*
chemical_list: D015415:Biomarkers; D010455:Peptides