Faculty Collaboration Database

Adhesion at calcium oxalate crystal surfaces and the effect of urinary constituents. Proc Natl Acad Sci U S A 2005 Jan 11;102(2):267-72

Date

12/31/2004

Pubmed ID

15625112

Pubmed Central ID

PMC544292

DOI

10.1073/pnas.0406835101

Scopus ID

2-s2.0-12244279575 (requires institutional sign-in at Scopus site)   179 Citations

Abstract

Kidney stones, aggregates of microcrystals, most commonly contain calcium oxalate monohydrate (COM) as the primary constituent. The aggregation of COM microcrystals and their attachment to epithelial cells are thought to involve adhesion at COM crystal surfaces, mediated by anionic molecules or urinary macromolecules. Identification of the most important functional group-crystal face adhesive combinations is crucial to understanding the stability of COM aggregates and the strength of their attachments to epithelial cell surfaces under flow in the renal tubules of the kidney. Here, we describe direct measurements of adhesion forces, by atomic force microscopy, between various functional groups and select faces of COM crystals immersed in aqueous media. Tip-immobilized carboxylate and amidinium groups displayed the largest adhesion forces, and the adhesive strength of the COM crystal faces decreased in the order (100) > (121) > (010), demonstrating that adhesion is sensitive to the structure and composition of crystal faces. The influence of citrate and certain urinary proteins on adhesion was examined, and it was curious that osteopontin, a suspected regulator of stone formation, increased the adhesion force between a carboxylate tip and the (100) crystal face. This behavior was unique among the various combinations of additives and COM crystal faces examined here. Collectively, the force measurements demonstrate that adhesion of functional groups and binding of soluble additives, including urinary macromolecules, to COM crystal surfaces are highly specific in nature, suggesting a path toward a better understanding of kidney stone disease and the eventual design of therapeutic agents.

Author List

Sheng X, Jung T, Wesson JA, Ward MD

Author

Jeffrey A. Wesson MD, PhD Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adhesiveness
Calcium Oxalate
Citric Acid
Crystallization
Humans
Kidney Calculi
Microscopy, Atomic Force
Protein Binding