Related Experiment Video

Updated: Oct 27, 2025

Functional Assessment of Intestinal Tight Junction Barrier and Ion Permeability in Native Tissue by Ussing Chamber Technique
06:43

Functional Assessment of Intestinal Tight Junction Barrier and Ion Permeability in Native Tissue by Ussing Chamber Technique

Published on: May 26, 2021

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Tsc1 regulates tight junction independent of mTORC1

Mingqiang Lai1, Wenchong Zou1, Zelong Han2

  • 1State Key Laboratory of Organ Failure Research, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China.

Proceedings of the National Academy of Sciences of the United States of America
|July 24, 2021
PubMed

Insights

Tuberous sclerosis complex 1 (Tsc1) is crucial for epithelial tight junction formation, independent of its known tumor suppressor role. Its absence disrupts cell junctions, leading to diseases like Crohn's and psoriasis.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Dermatology

Background:

  • Tuberous sclerosis complex 1 (Tsc1) is a known tumor suppressor, regulating mTORC1 activity with Tsc2.
  • The precise role of Tsc1 in epithelial cell junction formation remains largely unexplored.
  • Dysfunctional cell junctions are implicated in various human diseases.

Purpose of the Study:

  • To investigate the role of Tsc1 in epithelial tight junction (TJ) formation.
  • To elucidate the molecular mechanisms by which Tsc1 influences TJ structure.
  • To explore the potential link between Tsc1 deficiency and TJ-related human diseases.

Main Methods:

  • Studied Tsc1 localization and binding partners in epithelial cells.
  • Utilized mouse models with intestine-specific or inducible Tsc1 ablation.
  • Examined epithelial tissues from patients with Crohn's disease and psoriasis.

Main Results:

  • Tsc1, independent of Tsc2/mTORC1, is essential for TJ formation.
  • Tsc1 binds myosin 6 to anchor the actin cytoskeleton to junctional proteins (β-catenin, ZO-1).
  • Tsc1 deficiency in mice causes intestinal and skin epithelial defects, mimicking Crohn's and psoriasis.
  • Reduced Tsc1 levels observed in human Crohn's and psoriasis tissues correlate with TJ impairment.

Conclusions:

  • Tsc1 plays a critical, previously unrecognized role in establishing epithelial tight junctions.
  • Tsc1's function in cell junction integrity is independent of its tumor suppressor activity.
  • Tsc1 deficiency is a potential underlying factor in TJ-related human diseases like Crohn's and psoriasis.
Keywords:
Myo6Tsc1cell adhesionmTORC1tight junction–related disease

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