Increased calcium oxalate monohydrate crystal binding to injured
renal tubular epithelial cells in culture.
Verkoelen, Carl F., Burt G. Van Der Boom, Adriaan B. Houtsmuller,
Fritz H. Schr[diaeresis]oder,and Johannes C. Romijn.
Departments of Urology and Pathology, Erasmus University and
Academic Hospital Dijkzigt Rotterdam.
APStracts 5:0019F, 1998.
The retention of crystals in the kidney is considered to be a crucial
step in the development of a renal stone. This study demonstrates the
time-dependent alterations in the extent of calcium oxalate
monohydrate (COM) crystal binding to Madin-Darby canine kidney (MDCK)
cells during their growth to confluency and during the healing of
wounds made in confluent monolayers. As determined by radiolabeled
COM crystal binding studies and confirmed by confocal scanning laser
microscopy (CSLM), relatively large amounts of crystals (10.4+/-0.4
[mu]g/cm2) bound to subconfluent cultures that still exhibited a low
transepithelial electrical resistance (TER<400 [OMEGA].cm2). The
development of junctional integrity, indicated by a high resistance
(TER>1500 [OMEGA].cm2), was followed by a decrease of the crystal
binding capacity to almost undetectable low levels (0.13+/-0.03
[mu]g/cm2). Epithelial injury resulted in increased crystal
adherence. The highest level of crystal binding was observed 2 days
post-injury when the wounds were already morphologically closed but
TER was still low. Confocal images showed that during the repair
process, crystals selectively adhered to migrating cells at the wound
border and to stacked cells at sites were the wounds were closed.
After the barrier integrity was restored, crystal binding decreased
again to the same low levels as in undamaged controls. These results
indicate that whereas functional MDCK monolayers are largely
protected against COM crystal adherence, epithelial injury and the
subsequent process of wound healing leads to increased crystal
binding.
Received 17 June 1997; accepted in final form 7 January 1998.
APS Manuscript Number F199-7.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 28 January 1998