Molecular Mechanism of Adhesion of Monohydrate and Dihydrate Calcium Oxalate Crystals on Injured Kidney Epithelial Cells

Effects of cell injury on calcium oxalate monohydrate(COM) and calcium oxalate dihydrate(COD) microcrystalline adhesion and cellular response of calcium oxalate microcrystalline on African green monkey renal epithelial(Vero) cells after adhesion were evaluated. COM amd COD crystal adhesion to injured Vero cells increased oxidative damage degree, the LDH release amount, reactive oxygen species (ROS) and dead cells and decreased cell viability. The cells shrinked and apoptotic bodies appeared. COM crystals caused more serious damage to injured Vero cells than COD crystals. The results of scanning electron microscopy (SEM) showed that the adhesive capacity of injured Vero cells to COM was significantly stronger than the control group, which enhanced crystals adhesion and aggregation. Laser scanning confocal microscope showed that Vero cell injury increased the expression of crystal binding hyaluronic acid (HA) molecules which were the most important reasons for promoting microcrystalline adhesion. The microcrystalline adhesion and aggregation on cellular surface were positively correlated to cell injury degree. These findings indicated that cell injury was the leading risk factor of kidney stone formation, which may provide insights into the mechanisms of kidney stone formation from molecular and cellular levels.