Related Experiment Video
Updated: Mar 14, 2026
10:22
In Vitro and In Vivo Approaches to Determine Intestinal Epithelial Cell Permeability
Published on: October 19, 2018
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Aftiphilin Regulation of Myosin Light Chain Kinase Activity Promotes Actin Dynamics and Intestinal Epithelial Barrier
Ivy Ka Man Law1, Kai Fang1, Charalabos Pothoulakis1
1Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, CA, United States.
Frontiers in Gastroenterology (Lausanne, Switzerland)
|March 13, 2026
Summary
Aftiphilin (AFTPH) reduction increases intestinal permeability during colitis. AFTPH regulates epithelial barrier function by modulating myosin light chain kinase (MLCK) activity and actin organization.
Area of Science:
- Gastroenterology
- Cell Biology
- Molecular Biology
Background:
- Inflammation in ulcerative colitis (UC) compromises colonic epithelial barrier function.
- Aftiphilin (AFTPH) expression is reduced in inflamed colonic tissues.
- Epithelial barrier dysfunction is linked to tight junction (TJ) proteins and actomyosin regulation.
Purpose of the Study:
- To investigate the role of aftiphilin (AFTPH) in regulating intestinal epithelial permeability.
- To determine if reduced AFTPH levels contribute to increased permeability during colitis.
Main Methods:
- Silencing of AFTPH in polarized colonic epithelial cells.
- Measurement of transepithelial electric resistance (TEER), ion flux, and dextran permeability.
- Analysis of TJ protein expression, MLCK activity, and actin filament arrangement.
Main Results:
- AFTPH silencing decreased TEER and increased ion/dextran permeability.
- AFTPH deficiency altered junctional Occludin levels and affected actin filament organization.
- AFTPH co-localized with MLCK, attenuated its activity, and inhibition of MLCK reversed permeability defects.
Conclusions:
- Aftiphilin (AFTPH) is a key regulator of intestinal epithelial barrier function.
- AFTPH modulates epithelial permeability by interfering with MLCK/MLC interactions and affecting actin polymerization.
- Targeting AFTPH or MLCK may offer therapeutic strategies for inflammatory bowel diseases like UC.
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