three-dimensional-culture-murine-colonic-crypts-to-study-intestinal

Three-Dimensional Culture of Murine Colonic Crypts to Study Intestinal Stem Cell Function <em>Ex Vivo</em>

The intestinal epithelium regenerates every 5-7 days, and is controlled by the intestinal epithelial stem cell (IESC) population located at the bottom of ...

East Carolina University

Claudin-7 knockout (CLDN7) mice display renal salt wasting and dehydration phenotypes. To address the role of CLDN7 in kidneys, we established collecting duct (CD) cell lines from CLDN7 and CLDN7 mouse kidneys. We found that deletion of CLDN7 increased the transepithelial resistance (TER) and decreased the paracellular permeability for Cl and Na in CLDN7 CD cells. Inhibition of transcellular Cl and Na channels has no significant effect on TER or dilution potentials. Current-voltage curves were linear in both CLDN7 and CLDN7 CD cells, indicating that the ion flux was through the paracellular pathway. The impairment of Cl and Na permeability phenotype can be rescued by CLDN7 re-expression. We also found that WNK4 (its mutations lead to hypertension) expression, but not WNK1, was significantly increased in CLDN7 CD cell lines as well as in primary CLDN7 CD cells, suggesting that the expression of WNK4 was modulated by CLDN7. In addition, deletion of CLDN7 upregulated the expression level of the apical epithelial sodium channel (ENaC), indicating a potential cross-talk between paracellular and transcellular transport systems. This study demonstrates that CLDN7 plays an important role in salt balance in renal CD cells and modulating WNK4 and ENaC expression levels that are vital in controlling salt-sensitive hypertension.

Claudin-7 Modulates Cl and Na Homeostasis and WNK4 Expression in Renal Collecting Duct Cells.

Claudin-7 (Cldn7) is a tight junction (TJ) membrane protein located at the apical TJ and basolateral side of intestinal epithelial cells. Deletion of Cldn7 by gene targeting leads to the inflammatory bowel disease-like phenotype in mice, which includes weight loss, diarrhea, mucosa ulceration, and severe intestinal epithelial damage. In this study, we test our hypothesis that Cldn7 plays a critical role in regulating intestinal crypt stem cell functions.

Article	Year
Claudin-7 Modulates Cl and Na Homeostasis and WNK4 Expression in Renal Collecting Duct Cells. International journal of molecular sciences\| PubMed ID: 31382627	2019
Tight Junction Protein Claudin-7 Is Essential for Intestinal Epithelial Stem Cell Self-Renewal and Differentiation. Cellular and molecular gastroenterology and hepatology\| PubMed ID: 31874254	2020

Yan-Hua Chen

Biography

JoVE Journal Publications

Other Publications