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Updated: Jul 18, 2026
06:07
RNA Isolation from Mouse Ocular Lens Epithelium and Fiber Cell Bulk Masses
Published on: October 10, 2025
Proteolytic mechanisms underlying mitochondrial degradation in the ocular lens
Anna J Zandy1, Steven Bassnett
1Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Investigative Ophthalmology & Visual Science
|January 2, 2007
Summary
The lens VEIDase, responsible for organelle breakdown during eye lens development, is identified as the proteasome. Inhibiting the ubiquitin-proteasome pathway prevents organelle removal, highlighting its role in lens clarity.
Area of Science:
- Ophthalmology
- Cell Biology
- Biochemistry
Background:
- During ocular lens development, intracellular organelles are eliminated from the central visual axis to ensure transparency.
- This organelle degradation is linked to increased VEIDase (caspase-6-like) activity, but evidence suggests it's not caspase-6.
Purpose of the Study:
- To identify the specific enzyme responsible for lens VEIDase activity.
- To investigate the role of this enzyme in the breakdown of organelles within developing lens cells.
Main Methods:
- Size-exclusion chromatography was used to estimate the molecular mass of lens VEIDase.
- Proteasome inhibitors were tested for their effect on lens VEIDase activity.
- The ubiquitin-proteasome pathway (UPP) was inhibited in vivo using lactacystin to assess its impact on mitochondrial degradation.
Main Results:
- Lens VEIDase activity was found to be approximately 700 kDa and was inhibited by proteasome inhibitors.
- Inhibition of the proteasome in vivo led to the accumulation of ubiquitinated proteins and lens opacification.
- The programmed degradation of mitochondrial proteins was blocked in lactacystin-treated eyes.
Conclusions:
- Lens VEIDase activity is attributed to the proteasome.
- The ubiquitin-proteasome pathway likely plays a crucial role in removing organelle components during lens fiber cell differentiation.
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