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Functional Assessment of Intestinal Tight Junction Barrier and Ion Permeability in Native Tissue by Ussing Chamber Technique
Published on: May 26, 2021
Claudins 6, 9, and 13 are developmentally expressed renal tight junction proteins
Ghazala Abuazza1, Amy Becker, Scott S Williams
1Deptartment of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9063, USA.
American Journal of Physiology. Renal Physiology
|June 16, 2006
Summary
Neonatal kidneys express unique claudins (6, 9, 13) not found in adults, explaining developmental changes in kidney paracellular permeability. These claudins are crucial for ion transport maturation.
Area of Science:
- Nephrology
- Molecular Biology
- Developmental Biology
Background:
- The adult proximal tubule exhibits high active transcellular and passive paracellular NaCl transport.
- Neonatal proximal tubules differ from adult tubules in passive paracellular transport, showing maturational changes in ion flux.
- Claudins, key proteins regulating paracellular pathway permeability, vary in expression and determine kidney paracellular characteristics.
Purpose of the Study:
- To identify developmental claudin isoforms in the neonatal versus adult mouse kidney.
- To investigate the role of specific claudin isoforms in the maturational changes of paracellular permeability in the kidney.
Main Methods:
- Reverse transcription polymerase chain reaction (RT-PCR) was used to detect claudin mRNA expression in neonatal and adult kidneys.
- Real-time RT-PCR quantified claudin mRNA levels, comparing neonatal and adult kidney samples.
- Western blot analysis and immunohistochemistry were employed to assess claudin protein expression and localization.
Main Results:
- Claudin 6, claudin 9, and claudin 13 were expressed in neonatal kidneys but were absent or barely detectable in adult kidneys.
- Real-time RT-PCR confirmed significantly lower expression of claudin 6 mRNA in adult kidneys compared to neonates, with claudin 9 and 13 detected only in neonates.
- Immunohistochemistry revealed high claudin 6 expression in neonatal kidney tubules and ducts, with no detectable expression in adult kidneys.
Conclusions:
- Claudin 6, 9, and 13 are developmentally expressed claudin isoforms in the mouse kidney.
- These specific claudin isoforms likely contribute to the observed maturational changes in kidney paracellular permeability and ion transport.
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