1. Mechanism of atopic cataract caused by eosinophil granule major basic protein.
- Author
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Yamamoto N, Hiramatsu N, Isogai S, Kondo M, Imaizumi K, and Horiguchi M
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Aqueous Humor immunology, Aqueous Humor metabolism, Case-Control Studies, Cataract blood, Cataract pathology, Cataract Extraction, Cell Survival immunology, Cells, Cultured, Eosinophil Major Basic Protein analysis, Eosinophil Major Basic Protein immunology, Eosinophil Major Basic Protein isolation & purification, Eosinophils immunology, Epithelial Cells immunology, Epithelial Cells metabolism, Female, Humans, Lens, Crystalline cytology, Lens, Crystalline immunology, Lens, Crystalline pathology, Lens, Crystalline surgery, Male, Primary Cell Culture, Proteoglycans analysis, Proteoglycans immunology, Proteoglycans isolation & purification, Recombinant Proteins immunology, Recombinant Proteins isolation & purification, Recombinant Proteins metabolism, Young Adult, Cataract immunology, Eosinophil Major Basic Protein metabolism, Eosinophils metabolism, Proteoglycans metabolism
- Abstract
Atopic cataracts develop under the ages of 40 years, after which visual acuity rapidly declines. However, the mechanism underlying the development of atopic cataracts is not yet clear. We focused on the eosinophil granule major basic protein (MBP), which was detected in the aqueous humor of atopic cataracts previously, and which was cytotoxic. Specifically, we investigated its origin in this fluid and its effects on lens epithelial cells (LECs). MBP immunostaining was positive in atopic cataract-derived LECs, but negative in age-related cataract-derived LECs. MBP mRNA was not detected in either type of cataract, but protein was detected in the aqueous humor. Furthermore, the flare values associated with atopic cataracts were higher than those with age-related cataracts. When MBP was purified from eosinophils or recombinant MBP was added to LEC culture medium, cell viability decreased in a concentration-dependent manner, but an MBP antibody neutralized the cytotoxic effect of this protein towards these cells. These results were consistent with the flow of MBP into the aqueous humor from the blood due to a compromised blood-aqueous barrier. Thus, MBP could further penetrate the lens capsule and adhere to LECs, resulting in decreased cell viability and the development of atopic cataracts.
- Published
- 2020
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