Cell type-specific acquired protection from crystal adherence by renal tubule cells in culture.
BACKGROUND
Adherence of crystals to the surface of renal tubule epithelial cells is considered an important step in the development of nephrolithiasis. Previously, we demonstrated that functional monolayers formed by the renal tubule cell line, Madin-Darby canine kidney (MDCK), acquire protection against the adherence of calcium oxalate monohydrate crystals. We now examined whether this property is cell type specific. The susceptibility of the cells to crystal binding was further studied under different culture conditions.


METHODS
Cell-type specificity and the influence of the growth substrate was tested by comparing calcium oxalate monohydrate crystal binding to LLC-PK1 cells and to two MDCK strains cultured on either permeable or impermeable supports. These cell lines are representative for the renal proximal tubule (LLC-PK1) and distal tubule/collecting duct (MDCK) segments of the nephron, in which crystals are expected to be absent and present, respectively.


RESULTS
Whereas relatively large amounts of crystals adhered to subconfluent MDCK cultures, the level of crystal binding to confluent monolayers was reduced for both MDCK strains. On permeable supports, MDCK cells not only obtained a higher level of morphological differentiation, but also acquired a higher degree of protection than on impermeable surfaces. Crystals avidly adhered to LLC-PK1 cells, irrespective of their developmental stage or growth substrate used.


CONCLUSIONS
These results show that the prevention of crystal binding is cell type specific and expressed only by differentiated MDCK cells. The anti-adherence properties acquired by MDCK cells may mirror a specific functional characteristic of its in situ equivalent, the renal distal tubule/collecting ducts.
Verkoelen
C F
CF
Department of Urology, Erasmus University, Rotterdam, The Netherlands. Verkoelen@uro.fgg.eur.nl
van der Boom
B G
BG
Kok
D J
DJ
Houtsmuller
A B
AB
Visser
P
P
Schröder
F H
FH
Romijn
J C
JC
D000818:Animals; D002129:Calcium Oxalate / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology; D002460:Cell Line; D048429:Cell Size / Q000502:physiology; D003460:Crystallization; D015194:Diffusion Chambers, Culture; D004285:Dogs; D007685:Kidney Tubules, Collecting / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D007687:Kidney Tubules, Proximal / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D018374:LLC-PK1 Cells; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D010042:Ouabain / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013552:Swine; D013997:Time Factors
D002129:Calcium Oxalate; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase