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Alpha11 integrin in the human cornea: importance in development and disease
Berit Byström1, Sergio Carracedo, Anders Behndig
1Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden.
Investigative Ophthalmology & Visual Science
|June 12, 2009
Summary
The alpha11 integrin chain is present in developing corneas and elevated in keratoconus, suggesting a role in corneal development and scarring. This protein is produced by corneal fibroblasts and its expression increases with TGF-beta treatment.
Area of Science:
- Ophthalmology
- Cell Biology
- Developmental Biology
Background:
- The cornea's structural integrity relies on extracellular matrix components and cellular interactions.
- Integrins, cell surface receptors, play crucial roles in cell adhesion, migration, and signaling.
- Alpha11 integrin is a component of specific integrin receptors involved in matrix interactions.
Purpose of the Study:
- To investigate the distribution of the alpha11 integrin chain in the developing human cornea.
- To analyze alpha11 integrin expression in normal and diseased adult corneas, including keratoconus and pseudophakic bullous keratopathy (PBK).
Main Methods:
- Immunohistochemistry was performed on fetal and adult human corneas using antibodies against alpha11 integrin, collagens I, IV, V, and alpha-smooth muscle actin (alpha-SMA).
- Cell cultures of human corneal fibroblasts/myofibroblasts were used to determine the cellular source of alpha11 integrin.
- The effect of TGF-beta on alpha11 integrin and alpha-SMA expression was examined in cell cultures.
Main Results:
- Alpha11 integrin was found in the anterior corneal stroma during early fetal development (10-17 weeks of gestation).
- Expression was weak in normal adult corneas and Fuchs' dystrophy, variable in PBK, and strongly expressed in the anterior stroma of keratoconus corneas.
- Human corneal fibroblasts/myofibroblasts produced alpha11 integrin, with increased expression observed after TGF-beta treatment, along with alpha-SMA.
Conclusions:
- Alpha11 integrin is present during early corneal development.
- Enhanced alpha11 integrin expression in keratoconus, particularly with scarring, suggests a role in collagen deposition and matrix remodeling.
- The findings indicate alpha11 integrin's involvement in corneal development and pathological conditions like keratoconus with compromised basement membrane integrity.
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