棘阿米巴对体外培养人角膜上皮细胞的损伤作用

Cytopathic effect of acanthamoeba on human corneal epithelial cells cultured in vitro

目的观察棘阿米巴对体外培养人角膜上皮细胞(corneal epithelial cells,CECs)的损伤作用。方法以呈浓度梯度的棘阿米巴滋养体与体外培养人CECs作用,24h内在不同时间点观察细胞的受损程度。最终选用每孔1×106mL-1的棘阿米巴滋养体与CECs作用,于3h、6h、9h、24h在光镜和扫描电镜下观察棘阿米巴致人CECs损伤的过程。结果每孔10×103mL-1以下浓度的棘阿米巴不能引起明显的细胞损伤,每孔0.1×106mL-1和1×106mL-1的棘阿米巴可引起细胞损伤,且随时间的延长和棘阿米巴浓度的增加,人CECs受损程度加重。棘阿米巴与CECs共培养过程中,首先看到人CECs皱缩、细胞间隙形成,然后棘阿米巴变形,伸出吸盘样结构至细胞间缝隙处,并引起细胞肿胀、空泡形成、细胞崩解及核溶解等病理变化,且阿米巴分裂、增生活跃。结论CECs间紧密的缝隙连接是棘阿米巴侵袭人CECs的重要屏障,并引起一系列病理变化,同时CECs又可作为棘阿米巴良好的养料,促使其活跃分裂、增生,导致CECs的进一步损伤,形成恶性循环。

Objective To investigate the cytopathic effect of acanthamoeba on human corneal epithelial cells （CECs） cultured in vitro. Methods The cytopathic effect of acanthamoeba with different concentrations on human CECs was observed at different time points during 24 hours. Ultimately 1 ×10^6 mL^-1 acanthamoeba was chosen ,and its cytopathic effect on human CECs was observed at 3 hours,5 hours,9 hours, 24 hours under light microscope and scanning electron microscope. Results Acanthamoeba with the concentrations less than 10×10^6 mL^-1 had no cytopathic effect on human CECs,but that with 0. 1×10^6 mL^-1 and 1×10^6 mL^-1 had effect,and the effect was more serious with the time enlonged and the concentrations increased. During coculture period, firstly, human CECs shrinked with the formation of intracellular spaces. Then acanthamoeba deformed, and inserted sucker-like structure to the gaps of the cells. Cellular swelling, vacuolization, cells disruption, even caryolysis were seen, and acanthamoeba were found with active division and proliferation. Conclusion The relative resistance of human CECs to acanthamoeba may due to the tight junction between cells, and a series pathological change may be caused. Human CECs are nutrient for acanthamoeba, and help them to split and proliferate, which can cause further damage to cells. At last, vicious cycle happens.