HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 291/6/F1132    most recent 00063.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (17) Citing Articles via Google Scholar Google Scholar Articles by Abuazza, G. Articles by Baum, M. Search for Related Content PubMed PubMed Citation Articles by Abuazza, G. Articles by Baum, M.

Claudins 6, 9, and 13 are developmentally expressed renal tight junction proteins

Departments of ¹Pediatrics and ²Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas

Submitted 22 February 2006 ; accepted in final form 1 June 2006

The adult proximal tubule is a low-resistance epithelium where there are high rates of both active transcellular and passive paracellular NaCl transport. We have previously demonstrated that the neonatal rabbit and rat proximal tubule have substantively different passive paracellular transport properties than the adult proximal tubule, which results in a maturational change in the paracellular passive flux of ions. Neonatal proximal tubules have a higher P_Na/P_Cl ratio and lower chloride and bicarbonate permeabilities than adult proximal tubules. Claudins are a large family of proteins which are the gate keepers of the paracellular pathway, and claudin isoform expression determines the permeability characteristics of the paracellular pathway. Previous studies have shown that claudins 1, 2, 3, 4, 5, 7, 8, 10, 11, 12, 15, and 16 are expressed in the adult mouse kidney. To determine whether there are developmental claudin isoforms, we compared the claudin isoforms present in the neonatal and adult kidney using RT-PCR to detect mRNA of claudin isoforms. Claudin 6, claudin 9, and claudin 13 were either not expressed or barely detectable in the adult mouse kidney using traditional PCR, but were expressed in the neonatal mouse kidney. Using real-time RT-PCR, we were able to detect a low level of claudin 6 mRNA expression in the adult kidney compared with the neonate, but claudin 9 and claudin 13 were only detected in the neonatal kidney. There was the same maturational decrease in these claudin proteins with Western blot analysis. Immunohistochemistry showed high levels of expression of claudin 6 in neonatal proximal tubules, thick ascending limb, distal convoluted tubules, and collecting ducts in a paracellular distribution but there was no expression of claudin 6 in the adult kidney. Using real-time RT-PCR claudin 6 and 9 mRNA were present in 1-day-old proximal convoluted tubules and were virtually undetectable in proximal convoluted tubules from adults. Claudin 13 was not detectable in neonatal or adult proximal convoluted tubules. In summary, we have identified developmentally expressed claudin isoforms, claudin 6, claudin 9, and claudin 13. These paracellular proteins may play a role in the maturational changes in paracellular permeability.

renal tubule; renal development; paracellular pathway; neonatal kidney

This article has been cited by other articles:

				J. Gattineni, C. Bates, K. Twombley, V. Dwarakanath, M. L. Robinson, R. Goetz, M. Mohammadi, and M. Baum FGF23 decreases renal NaPi-2a and NaPi-2c expression and induces hypophosphatemia in vivo predominantly via FGF receptor 1 Am J Physiol Renal Physiol, August 1, 2009; 297(2): F282 - F291. [Abstract] [Full Text] [PDF]

				M. Baum Postnatal developmental renal physiology: a study of historic significance Am J Physiol Renal Physiol, April 1, 2009; 296(4): F667 - F668. [Abstract] [Full Text] [PDF]

				D. Sas, M. Hu, O. W. Moe, and M. Baum Effect of claudins 6 and 9 on paracellular permeability in MDCK II cells Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2008; 295(5): R1713 - R1719. [Abstract] [Full Text] [PDF]

				S. Angelow, R. Ahlstrom, and A. S. L. Yu Biology of claudins Am J Physiol Renal Physiol, October 1, 2008; 295(4): F867 - F876. [Abstract] [Full Text] [PDF]

				L. Zhao, E. Yaoita, M. Nameta, Y. Zhang, L. M. Cuellar, H. Fujinaka, B. Xu, Y. Yoshida, K. Hatakeyama, and T. Yamamoto Claudin-6 localized in tight junctions of rat podocytes Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2008; 294(6): R1856 - R1862. [Abstract] [Full Text] [PDF]

				J. Fujita-Yoshigaki, M. Matsuki-Fukushima, and H. Sugiya Inhibition of Src and p38 MAP kinases suppresses the change of claudin expression induced on dedifferentiation of primary cultured parotid acinar cells Am J Physiol Cell Physiol, March 1, 2008; 294(3): C774 - C785. [Abstract] [Full Text] [PDF]