Glaucomatous aqueous humor vesicles are smaller and differ in composition compared to controls
Anna Mueller1, Abdelrahman Anter2, Genea Edwards3
1Bascom Palmer Eye Institute, Miller School of Medicine at University of Miami, Miami, FL, 33136, USA; Miami Integrative Metabolomics Research Center, Miami, FL, 33136, USA; Herbert Wertheim College of Medicine, Florida International University, Florida, USA.
Experimental Eye Research
|June 29, 2023
Summary
Aqueous humor (AH) vesicles differ in size and composition between healthy individuals and primary open-angle glaucoma (POAG) patients. Larger control AH vesicles offer better collagen protection than smaller POAG vesicles.
Area of Science:
- Ophthalmology
- Cell Biology
- Biochemistry
Background:
- Cells utilize extracellular vesicles, including exosomes, for intercellular communication.
- Aqueous humor (AH) contains vesicles that may play a role in ocular health.
- Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness.
Purpose of the Study:
- To characterize and compare the properties of AH-derived vesicles from control and POAG patients.
- To investigate the functional differences in vesicle-mediated protection of collagen structures.
Main Methods:
- Isolation of AH vesicles via ultracentrifugation and exosome kits.
- Vesicle characterization using Nanotracker, DLS, AFM, and electron microscopy.
- Proteomic analysis (iTRAQ) and biochemical assays (dot blot, Western blot, ELISA) for protein and phospholipid composition.
Main Results:
- Distinct vesicle size distributions were observed in POAG vs. control AH.
- Reduced STT3B protein levels and altered phospholipid composition in POAG AH vesicles.
- POAG AH vesicles showed diminished protective capacity against Cathepsin D-induced collagen degradation compared to control vesicles.
Conclusions:
- AH vesicle size and composition are significantly altered in POAG.
- These alterations impair the protective function of AH vesicles, potentially impacting ocular structures like collagen beams.
- Vesicle size appears to be a critical factor in the protective efficacy of AH vesicles.
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