内毒素诱导外周血单核细胞释放β-葡萄糖苷酸酶的体外研究

Endotoxin regulates activity of human β-glucuronidase in peripheral blood mononuclear cells in vitro

目的研究内毒素(LPS)对正常人外周血单核细胞(PBMC)产生β-葡萄糖苷酸酶(β-GD)的影响,探讨胆石症的又一个发病机制。方法以生理盐水(对照组)和0.01、0.10、1.00、10.00和100.00μg/mL内毒素(LPS组)刺激体外培养的外周血单核细胞,并分别于培养的2、4、8、12和24h取上清液,采用酶促动力学方法于pH值4.5条件下检测β-GD活性。结果正常人PBMC在无LPS条件下可以产生具有一定活性的β-GD;在培养的4、8、12和24h,各LPS组β-GD活性显著高于对照组(以1.00μg/mLLPS组为例,与对照组β-GD活性分别为(1633.3±65.0)vs(1106.7±48.6),(1926.0±147.1)vs(1067.7±133.1),(1743.3±66.8)vs(1016.7±147.7),(1553.7±79.6)vs(1193.3±90.2)Fishman单位/106PBMC,t值分别为14.5、9.6、10.0和6.7,P<0.05)。结论LPS可以增加正常人PBMC释放β-GD,此途径可能是LPS参与胆石症发病的又一个机制。

[Objective] To investigate the effect of lipopolysaccharide(LPS) on β-glucuronidase(β-GD) activity in human peripheral blood mononuclear cells(PBMC),and discuss a kind of mechanism of cholelithiasis pathogenesis. [Methods] 0.01, 0.10, 1.00, 10.00 and 100.00 μg/mL of LPS or Saline(as control group)was applied to stimulate human PBMC, the time course of changes in β-GD enzyme activity in the medium was followed using enzyme kinetic method. [Results] Nonstimulated human PBMC(the control group)under in vitro conditions can produce β-GD, whose activity isn′t changed significantly during 24 hours. In contrast to the control group, the β-GD activity in the various LPS groups is significantly higher after cultured for 4, 8, 12 and 24 hours (taking 1.00 μg/mL LPS group and control group as example, the activity of these two groups is (1633.3±65.0) vs (1106.7±48.6), (1926.0±147.1) vs (1067.7±133.1), (1743.3±66.8) vs (1016.7±147.7), (1553.7±79.6) vs (1193.3±90.2) Fishman unit/106 PBMC, t value is 14.5, 9.6, 10.0 and 6.7, respectively, P﹤0.05). [Conclusions] LPS can increase PBMC to produce more human β-GD, which may be another mechanism of LPS taking part in the pathogenesis of cholelithiasis.