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Updated: May 21, 2026

Methods to Study Epithelial Transport Protein Function and Expression in Native Intestine and Caco-2 Cells Grown in 3D
Published on: March 16, 2017
System L Amino Acid Transporter LAT1 is required for Mouse Intestinal Epithelial Homeostasis.
Lingyu Bao1, Zhaoyi Peng1,2, Bingyin Shi3
1Section on Molecular Morphogenesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, MD, USA.
System L amino acid transporter 1 (slc7a5) is crucial for maintaining intestinal homeostasis. Inducible knockout of slc7a5 in adult mice reduces Paneth cells and increases crypt cell proliferation, suggesting an indirect role in cell regulation.
Area of Science:
- Gastroenterology and Hepatology
- Cell Biology
- Molecular Biology
Background:
- The adult mammalian intestinal epithelium undergoes continuous self-renewal through crypt cell proliferation.
- System L amino acid transporter 1 (slc7a5) transports amino acids and thyroid hormone, activating mTORC1 signaling.
- Previous studies indicated slc7a5's role in intestinal epithelial cell proliferation and differentiation.
Purpose of the Study:
- To investigate the role of slc7a5 in adult intestinal epithelial homeostasis.
- To elucidate the mechanism by which slc7a5 influences cell proliferation and differentiation.
Main Methods:
- Generation of a tamoxifen-inducible intestinal epithelial-specific slc7a5 knockout mouse model (slc7a5ind∆IEC).
- Analysis of intestinal crypt cell proliferation and Paneth cell populations in knockout mice.
- Comparison with stable intestinal epithelial cell-specific knockout (Slc7a5ΔIEC) animals during development.
Main Results:
- Inducible knockout of slc7a5 in adult mice led to a reduction in mature Paneth cells and increased crypt cell proliferation.
- The decrease in mature Paneth cells preceded the increase in cell proliferation.
- In stable knockout models, Paneth cell reduction occurred early in postnatal development, while increased proliferation was observed later.
Conclusions:
- Slc7a5 is essential for maintaining adult intestinal epithelial homeostasis.
- Slc7a5 appears to regulate cell proliferation indirectly by influencing Paneth cell differentiation.
- These findings highlight a novel mechanism involving amino acid transport in intestinal stem cell regulation.
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