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Connexin 46 and connexin 50 in selenite cataract
1A.T. Still University of Health Sciences, Kirksville College of Osteopathic Medicine, MO 63501-1443, USA. cfleschner@atsu.edu
Ophthalmic Research
|September 30, 2005
Summary
Selenite-induced cataracts in rats show altered phosphorylation of connexin 46 (Cx46) gap junction protein. However, overall levels of Cx46 and connexin 50 (Cx50) remain unchanged, suggesting altered function, not degradation, in cataract development.
Area of Science:
- Ophthalmology
- Cell Biology
- Biochemistry
Background:
- Gap junction proteins, connexin 46 (Cx46) and connexin 50 (Cx50), are crucial for lens transparency.
- Lens opacification, or cataract, can result from various factors, including chemical induction.
- The selenite-induced cataract model in rats is a well-established experimental system for studying cataractogenesis.
Purpose of the Study:
- To investigate the changes in lens gap junction proteins, specifically Cx46 and Cx50, during the development of selenite-induced cataracts.
- To determine if the expression or phosphorylation status of Cx46 and Cx50 is altered in cataractous lenses compared to normal lenses.
Main Methods:
- Cataracts were induced in Sprague-Dawley rats using sodium selenite injection.
- Membrane fractions were isolated from normal and cataractous rat lenses.
- Quantitative Western blot analysis was performed on urea-insoluble proteins to assess Cx46 and Cx50 levels and phosphorylation.
Main Results:
- A significant reduction in the phosphorylated form of Cx46 was observed in the major membrane fraction of cataractous lens cortex.
- No significant differences were found in the total amounts of Cx46 or Cx50 between normal and cataractous lenses across examined membrane fractions.
- These findings indicate that Cx46 and Cx50 are not proteolytically degraded in this cataract model.
Conclusions:
- Alterations in Cx46 phosphorylation suggest a potential change in gap junction function associated with selenite cataract development.
- Neither Cx46 nor Cx50 undergoes significant degradation in the selenite cataract model.
- Further research is warranted to elucidate the precise role of Cx46 phosphorylation in cataractogenesis.
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