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Sensing of Barrier Tissue Disruption with an Organic Electrochemical Transistor
Published on: February 10, 2014
Regulation of epithelial apical junctions and barrier function by Galpha13
Rino Donato1, Stephen A Wood, Ian Saunders
1Women's and Children's Health Research Institute, North Adelaide, South Australia, Australia.
Biochimica Et Biophysica Acta
|May 2, 2009
Summary
The heterotrimeric G-protein Galpha13 disrupts epithelial tight junctions, increasing permeability. Rho kinase signaling mediates these effects, distinct from Galpha12 pathways, impacting epithelial barrier function.
Area of Science:
- Cell Biology
- Molecular Biology
- Physiology
Background:
- Epithelial tight junctions are crucial for regulating paracellular solute movement.
- The role of heterotrimeric G-proteins in epithelial barrier function requires further elucidation.
Purpose of the Study:
- To investigate the role of the heterotrimeric G-protein Galpha13 in regulating epithelial tight junction barrier function.
- To identify the signaling pathways involved in Galpha13-mediated regulation of epithelial permeability.
Main Methods:
- Generation of MDCKII kidney epithelial cell lines with inducible expression of an active Galpha13 mutant (Galpha13Q226L).
- Assessment of paracellular permeability and analysis of tight junction and adherens junction protein localization.
- Inhibition studies using Rho kinase inhibitor (Y27632) and Src kinase inhibitor (PP2).
Main Results:
- Inducible expression of Galpha13Q226L increased paracellular permeability.
- Galpha13Q226L expression caused disruption and redistribution of tight and adherens junction proteins and induced basal stress fibers.
- Inhibition of Rho kinase abrogated junctional protein disruption and actin cytoskeleton changes, while Src kinase inhibition had no effect.
- Galpha13-mediated permeability increase was independent of Src kinase but partly dependent on Rho kinase signaling.
Conclusions:
- Galpha13 plays a significant role in regulating epithelial tight junction barrier function.
- Rho kinase signaling is a key mediator of Galpha13's effects on epithelial junctions and permeability.
- Galpha13 regulates epithelial barrier function through distinct signaling pathways compared to Galpha12.
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