Related Experiment Videos
Nuclear envelope barrier leak induced by dexamethasone.
Lilian Kastrup1, Hans Oberleithner, Yvonne Ludwig
1Institute of Physiology II, University of Muenster, Muenster, Germany.
Journal of Cellular Physiology
|August 20, 2005
Summary
Dexamethasone (dex) treatment causes nuclear pore complexes (NPCs) to dilate, forming giant pores. This NPC dilation transiently increases nuclear envelope permeability, allowing large molecules to enter the nucleus.
Area of Science:
- Cell biology
- Molecular biology
- Biophysics
Background:
- Nuclear pore complexes (NPCs) regulate transport between the nucleus and cytoplasm.
- NPCs limit the efficiency of gene transfection by restricting macromolecule entry into the nucleus.
Purpose of the Study:
- To analyze the structural details of NPC dilation induced by dexamethasone (dex).
- To correlate NPC structural changes with nuclear envelope permeability.
- To assess the potential of NPC dilation for improving gene transfection efficiency.
Main Methods:
- Atomic force microscopy (AFM) to visualize NPC structure.
- Electrophysiology to measure nuclear envelope permeability.
- Confocal fluorescence microscopy to track macromolecule entry.
Main Results:
- NPCs dilated up to approximately 140 nm within 5-11 minutes after dex injection.
- A novel 'giant pore' configuration, up to 300 nm in diameter, was observed.
- Nuclear envelope permeability significantly increased, allowing large macromolecules (77 kDa FITC-dextran) to enter the nucleus.
Conclusions:
- Dexamethasone (dex) treatment induces transient NPC dilation and giant pore formation.
- This process creates unspecific pathways for large macromolecules into the nucleus.
- Dex-induced NPC dilation shows potential for enhancing nuclear gene transfection efficiency.