Renal cell-urinary crystal interactions.

Crystals of calcium oxalate and calcium phosphate bind to anionic molecules on the apical surface of renal collecting duct cells. Atomic arrays on crystal faces interact stereospecifically with cell-surface anions to bind crystals that nucleate in tubular fluid, or those that nucleate directly on the plasma membrane. The internalization of adherent crystals, changes in gene expression, and secretion of specific proteins ensue, and appear to be important processes in crystal retention and kidney stone pathogenesis.