Adhesion of calcium oxalate (CaOx) crystals onto renal tubular epithelial cells is one of the critical steps in kidney stone formation. However, effects of crystal size on the crystal adhesive capability remained unclear. This study compared the adhesive capabilities of CaOx monohydrate (COM) crystals with various sizes (<10 μm, 20–30 μm, 50–60 μm, and > 80 μm). Crystal-cell adhesion assay showed size-dependent increase of COM crystal adhesion onto epithelial cell surface using the larger crystals. Identification of apical membrane proteins that could bind to COM crystals by tandem mass spectrometry (nanoLC-ESI-ETD MS/MS) demonstrated size-specific sets of the COM crystal-binding proteins. Among these, numbers of known oxalate-binding proteins and COM crystal receptors were greatest in the set of the largest size (>80 μm). Atomic force microscopy (AFM) revealed that adhesive forces between carboxylic-immobilized AFM tip and COM crystal surface and between COM-mounted AFM tip and renal epithelial cell surface were size-dependent (greater for the larger crystals). In summary, the adhesive capability of COM crystals is size-dependent – the larger the greater adhesive capability. These data may help better understanding of the pathogenic mechanisms of kidney stone formation at an initial stage when renal tubular cells are exposed to various sizes of COM crystals.

草酸钙（CaOx）晶体在肾小管上皮细胞上的粘附是肾结石形成的关键步骤之一。然而，晶体尺寸对晶体粘合能力的影响仍然不清楚。这项研究比较了各种尺寸（<10μm，20–30μm，50–60μm和> 80μm）的CaOx一水合物（COM）晶体的粘合能力。晶体细胞粘附试验表明，使用较大的晶体，COM晶体粘附在上皮细胞表面的大小依赖于增加。通过串联质谱（nanoLC-ESI-ETD MS / MS）鉴定可以与COM晶体结合的顶膜蛋白证明了COM晶体结合蛋白具有特定的大小。其中，已知草酸盐结合蛋白和COM晶体受体的数量在最大尺寸（> 80μm）的组中最大。原子力显微镜（AFM）显示，羧基固定的AFM尖端与COM晶体表面之间以及COM安装的AFM尖端与肾上皮细胞表面之间的粘附力取决于大小（较大的晶体更大）。总之，COM晶体的粘合能力取决于尺寸–越大，粘合能力越强。这些数据可能有助于更好地了解肾小管细胞暴露于各种大小的COM晶体的初始阶段肾结石的致病机制。COM晶体的粘合能力取决于尺寸–越大，粘合能力越强。这些数据可能有助于更好地了解肾小管细胞暴露于各种大小的COM晶体的初始阶段肾结石的致病机制。COM晶体的粘合能力取决于尺寸–越大，粘合能力越强。这些数据可能有助于更好地了解肾小管细胞暴露于各种大小的COM晶体的初始阶段肾结石的致病机制。