Deletion of claudin-10 (Cldn10) in the thick ascending limb impairs paracellular sodium permeability and leads to hypermagnesemia and nephrocalcinosis

Item Type:	Article
Title:	Deletion of claudin-10 (Cldn10) in the thick ascending limb impairs paracellular sodium permeability and leads to hypermagnesemia and nephrocalcinosis
Creators Name:	Breiderhoff, T. and Himmerkus, N. and Stuiver, M. and Mutig, K. and Will, C. and Meij, I.C. and Bachmann, S. and Bleich, M. and Willnow, T.E. and Mueller, D.
Abstract:	In the kidney, tight junction proteins contribute to segment specific selectivity and permeability of paracellular ion transport. In the thick ascending limb (TAL) of Henle's loop, chloride is reabsorbed transcellularly, whereas sodium reabsorption takes transcellular and paracellular routes. TAL salt transport maintains the concentrating ability of the kidney and generates a transepithelial voltage that drives the reabsorption of calcium and magnesium. Thus, functionality of TAL ion transport depends strongly on the properties of the paracellular pathway. To elucidate the role of the tight junction protein claudin-10 in TAL function, we generated mice with a deletion of Cldn10 in this segment. We show that claudin-10 determines paracellular sodium permeability, and that its loss leads to hypermagnesemia and nephrocalcinosis. In isolated perfused TAL tubules of claudin-10-deficient mice, paracellular permeability of sodium is decreased, and the relative permeability of calcium and magnesium is increased. Moreover, furosemide-inhibitable transepithelial voltage is increased, leading to a shift from paracellular sodium transport to paracellular hyperabsorption of calcium and magnesium. These data identify claudin-10 as a key factor in control of cation selectivity and transport in the TAL, and deficiency in this pathway as a cause of nephrocalcinosis.
Keywords:	Biological Transport, Calcium, Claudins, Drinking, Embryonic Stem Cells, Gene Deletion, Homeostasis, Knockout Mice, Loop of Henle, Magnesium, Metabolic Diseases, Nephrocalcinosis, Phenotype, Sodium, Water Deprivation, Animals, Mice
Source:	Proceedings of the National Academy of Sciences of the United States of America
ISSN:	0027-8424
Publisher:	National Academy of Sciences
Volume:	109
Number:	35
Page Range:	14241-14246
Date:	28 August 2012
Additional Information:	Erratum in: PNAS 109(37): 15072.
Official Publication:	https://doi.org/10.1073/pnas.1203834109
PubMed:	View item in PubMed

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