Toxicity of sub-micron and micron calcium oxalate monohydrate on renal epithelial cells

Abstract

[Objective] This study aims to synthesize calcium oxalate monohydrate (COM) crystals with a size of 300 nm and 5 μm, respectively, and to compare their damage and adhesion ability toward human kidney proximal tubule epithelial cells (HKC). [Method] The injury degree of HKC caused by COM crystals was measured by detecting the cell viability, lactate dehydrogenase (LDH) release amounts, reactive oxygen species (ROS), cell death rate, hyaluronic acid (HA) expression and the crystal adhesion amount on cell surface. [Result] HKC cell viability, LDH release quantity, cell death rate and HA expression were closely associated with the size of COM crystals. The damage ability of 300 nm COM crystals on normal cells was higher than that of COM-5 μm crystals. The adhesive amount of small size COM crystals (62.4 μg/cm2) was higher than micron COM crystals (26.7 μg/cm2). The increased adhesion amount of small size COM crystal are related to its larger specific surface area, crystal face changes and larger cell contact probability. [Conclusions] The cytotoxicity of COM crystals toward HKC cells is size dependent. This study is helpful to further clarify the formation mechanism of COM calculi, and provide inspiration for its prevention and treatment.