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Invest Ophthalmol Vis SciDecember 20210 citations

Compositional Analysis of Extracellular Aggregates in the Eyes of Patients With Exfoliation Syndrome and Exfoliation Glaucoma.

De Maria Alicia, Zientek Keith D, David Larry L, Wilmarth Phillip A, Bhorade Anjali M, Harocopos George J, Huang Andrew J W, Hong Augustine R, Siegfried Carla J, Tsai Linda M


AI Summary

Researchers analyzed exfoliation material composition, finding consistent proteins like fibrillin-1 and LEFTY2. Elevated LEFTY2 in aqueous humor may be a biomarker for exfoliation glaucoma.

Abstract

Purpose

Exfoliation syndrome (XFS) is a condition characterized by the production of insoluble fibrillar aggregates (exfoliation material; XFM) in the eye and elsewhere. Many patients with XFS progress to exfoliation glaucoma (XFG), a significant cause of global blindness. We used quantitative mass spectrometry to analyze the composition of XFM in lens capsule specimens and in aqueous humor (AH) samples from patients with XFS, patients with XFG and unaffected individuals.

Methods

Pieces of lens capsule and samples of AH were obtained with consent from patients undergoing cataract surgery. Tryptic digests of capsule or AH were analyzed by high-performance liquid chromatography-mass spectrometry and relative differences between samples were quantified using the tandem mass tag technique. The distribution of XFM on the capsular surface was visualized by SEM and super-resolution light microscopy.

Results

A small set of proteins was consistently upregulated in capsule samples from patients with XFS and patients with XFG, including microfibril components fibrillin-1, latent transforming growth factor-β-binding protein-2 and latent transforming growth factor-β-binding protein-3. Lysyl oxidase-like 1, a cross-linking enzyme associated with XFS in genetic studies, was an abundant XFM constituent. Ligands of the transforming growth factor-β superfamily were prominent, including LEFTY2, a protein best known for its role in establishing the embryonic body axis. Elevated levels of LEFTY2 were also detected in AH from patients with XFG, a finding confirmed subsequently by ELISA.

Conclusions

This analysis verified the presence of suspected XFM proteins and identified novel components. Quantitative comparisons between patient samples revealed a consistent XFM proteome characterized by strong expression of fibrillin-1, lysyl oxidase-like-1, and LEFTY2. Elevated levels of LEFTY2 in the AH of patients with XFG may serve as a biomarker for the disease.


MeSH Terms

AgedAged, 80 and overAmino Acid OxidoreductasesAqueous HumorChromatography, High Pressure LiquidCrystallinsEnzyme-Linked Immunosorbent AssayExfoliation SyndromeFemaleFibrillin-1Fluorescent Antibody Technique, IndirectGlaucoma, Open-AngleHumansLatent TGF-beta Binding ProteinsLeft-Right Determination FactorsLens Capsule, CrystallineMaleMass SpectrometryMicroscopy, Electron, ScanningMiddle AgedProtein AggregatesAdipokines

Key Concepts4

Quantitative mass spectrometry analysis of lens capsule samples from patients with exfoliation syndrome (XFS) and exfoliation glaucoma (XFG) consistently upregulated fibrillin-1, latent transforming growth factor-β-binding protein-2, and latent transforming growth factor-β-binding protein-3.

MechanismBasic ScienceQuantitative mass spectrometry analysis of lens capsule specimensn=Patients with XFS and XFGCh16

Lysyl oxidase-like 1 was an abundant constituent of exfoliation material (XFM) in lens capsule samples from patients with exfoliation syndrome (XFS) and exfoliation glaucoma (XFG), as determined by quantitative mass spectrometry.

MechanismBasic ScienceQuantitative mass spectrometry analysis of lens capsule specimensn=Patients with XFS and XFGCh16

Elevated levels of LEFTY2 were detected in aqueous humor (AH) from patients with exfoliation glaucoma (XFG), a finding confirmed by ELISA, suggesting its potential as a biomarker.

DiagnosisBasic ScienceQuantitative mass spectrometry and ELISA analysis of aqueous humor samplesn=Patients with XFGCh16

The consistent exfoliation material (XFM) proteome in patients with exfoliation syndrome (XFS) and exfoliation glaucoma (XFG) is characterized by strong expression of fibrillin-1, lysyl oxidase-like-1, and LEFTY2, as revealed by quantitative mass spectrometry.

MechanismBasic ScienceQuantitative mass spectrometry analysis of lens capsule and aqueous humor samplesn=Patients with XFS and XFGCh16

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