不同羧基含量广金钱草多糖对草酸钙晶体生长、聚集及细胞表面黏附的抑制作用

Inhibitory effect of Desmodium styracifolium polysaccharides with different content of carboxyl groups on the growth,aggregation and cell adhesion of calcium oxalate crystals

为了探讨羧基化前后广金钱草多糖(DSPs)对草酸钙(CaC_(2)O_(4))晶体成核、生长和聚集的调控作用,采用FTIR、粉末X射线衍射、扫描电镜、ζ电位和热重分析(TGA)等方法,对具有不同羧基(—COOH)含量(质量分数)的DSPs调控形成的CaC_(2)O_(4)晶体进行表征,比较了各DSPs对纳米一水合草酸钙(nano-COM)损伤后HK-2细胞(人肾近端曲小管上皮细胞)表面的黏附分子的表达差异和nano-COM在细胞表面的黏附差异。结果表明,DSPs均可抑制COM晶体生长,并诱导二水合草酸钙(COD)晶体形成,同时增加CaC_(2)O_(4)晶体表面的ζ电位绝对值,抑制晶体间的聚集。随着多糖中—COOH含量从1.17%增加至7.45%、12.2%和17.7%,相应的多糖DSP0、DSP1、DSP2和DSP3对CaC_(2)O_(4)晶体生长的调控能力依次增强。TGA表明晶体中吸附有多糖,在0.2 g·L^(-1)DSPs存在下,掺入晶体中的DSP0、DSP1、DSP2和DSP3的质量分数分别为1.54%、2.94%、7.96%和8.12%。细胞实验表明,DSPs可显著降低HK-2细胞表面黏附分子CD44和Annexin A2的表达,并减少nano-COM在细胞表面的黏附量。DSPs能够抑制CaC_(2)O_(4)晶体成核、聚集、生长及其在肾上皮细胞表面的黏附,这些均有利于抑制CaC_(2)O_(4)肾结石的形成,其中羧基化程度最高的DSP3的能效最佳。

To explore the regulatory effect of Desmodium styracifolium polysaccharides before and after carboxymethylation(DSPs)on the nucleation,growth and aggregation of calcium oxalate(CaC_(2)O_(4))crystals,the CaC_(2)O_(4) crystals regulated by DSPs with different carboxyl(—COOH)contents(mass fractions)were characterized by FTIR,powder X-ray diffraction,scanning electron microscope,ζpotential and thermogravimetric analysis(TGA).The protective effect of DSPs on human renal proximal tubular epithelial cells(HK-2 cells)was evaluated by examining adhesion molecule expression and nano-COM(nano calcium oxalate monohydrate)cell adhesion.The results show that DSPs can inhibit the growth of COM crystals,induce the formation of calcium oxalate dihydrate(COD)crystals,increase the absolute value ofζpotential on the surface of CaC_(2)O_(4) crystals,and inhibit aggregation between crystals.When the—COOH content in the polysaccharide increased from 1.17%to 7.45%,12.2%and 17.7%,the ability of DSP0,DSP1,DSP2 and DSP3 to regulate the growth of CaC_(2)O_(4) crystals increased in sequence.TGA shows that polysaccharides are adsorbed in the crystal.In the presence of 0.2 g·L-1 DSPs,the mass fractions of DSP0,DSP1,DSP2 and DSP3 incorporated into the crystals were 1.54%,2.94%,7.96%and 8.12%,respectively.Cell experiments show that DSPs can significantly reduce the expression of adhesion molecules CD44 and Annexin A2 on the surface of HK-2 cells,and reduce the amount of nano-COM adhesion on the cell surface.DSPs can inhibit the nucleation,aggregation,and growth of CaC_(2)O_(4) crystals,and reduce the adhesion of nano-COM on renal epithelial cells,all these are beneficial to inhibit the formation of CaC_(2)O_(4) kidney stones,among which DSP3 with the highest degree of carboxylation has the best effect.