Localization of E-cadherin Along the Nephron Segments in the Rat Kidney / 대한해부학회지

ABSTRACT

E-cadherin is a cell adhesion molecule that is expressed abundantly in the kidney. However, the expression pattern in various renal epithelial cells is not well established. The purpose of this study was to determine the cellular localization along the nephron segments in the rat kidney. Kidneys from adult Sprague Dawley rats were fixed in 4% paraformaldehyde and processed for immunohistochemistry. Bumetanide-sensitive Na+/K+/2Cl- cotransporter (BSC1), thiazide-sensitive Na+/Cl- cotransporter (TSC), calbindin D28k, and H+-ATPase were used to identify the thick ascending, distal convoluted stubule, connecting tubule, and collecting duct, respectively. In the rat kidney, Ecadherin was expressed mainly in the basolateral domain of the collecting duct and papillary surface epithelial cells. The expression level of E-cadherin changed gradually in the connecting tubule and became moderate in the distal convoluted tubule, thick ascending limb, and loop of Henle. The S1 and S2 segment of the proximal tubule showed weak immunoreactivity. However, E-cadherin was not expressed in the S3 segment of the proximal tubule in the rat kidney. These results suggest that E-cadherin is a major adhesion molecule in the collecting duct and papillary surface epithelium, and that E-cadherin may play a critical role in maintaining the epithelial polarity of these nephron segments.