贝特舒对人角膜上皮细胞凋亡诱导作用的实验研究

Experimental studies of the apoptosis-inducing effect of betaxolol on human corneal epithelial cells

为了揭示常用青光眼药物贝特舒（betaxol01）对人角膜上皮（HCEP）细胞的毒性及其作用机理，使用不同质量浓度贝特舒对体外培养IqCEP细胞进行了处理，并利用倒置显微镜跟踪观察了细胞的生长和形态，用吖啶橙／溴化乙锭（AO／EB）荧光双染色法检测了质膜的通透性，用琼脂糖凝胶电泳法检测DNA的断片化，用透射电镜检测细胞的超微结构。发现在0．17500—2．80000g／L的质量浓度范围内，贝特舒对HCEP细胞具有显著的毒性。并随着质量浓度的提高和处理时间的延长而逐渐增大，处理24h即可使大部分细胞皱缩死亡；进一步的研究结果发现，质量浓度为0．17500—2．80000g／L的贝特舒能显著提高HCEP细胞的质膜通透性，并使其出现DNA断片化、染色质凝缩和形成凋亡小体等凋亡细胞的结构变化。可见，在贝特舒0．17500—2．80000g／L的质量浓度范围内对HCEP细胞具有显著的毒性，并具有质量浓度和时间依赖性，其毒性作用的发挥是通过诱导细胞凋亡实现的，在眼科I旌床应用中毒副作用极大。

To examine the cytotoxic effect of betaxolol, a widely used anti-glaucoma drug, on human corneal epithelial （HCEP） cells and its underlying mechanisms, in vitro cultured I-ICEP cells were treated with betaxolol at different do- ses. And the growth situation and morphology of the cells were monitored with an inverted light microscope, plasma membrane permeability of them was detected by acridine orange/ethidium bromide （AO/EB） double-fluorescent stai- ning, DNA fragmentation and ultrastructure of them were investigated by DNA agarose gel electrophoresis and transmis- sion electron microscopy （TEM）, respectively. It was found that betaxolol at doses of 0.175 00-2.800 00 g/L showed significant cytotoxicity to HCEP cells. The cytotoxicity increased with dose and time, and most of the cells shrunk and died 24 h post treatment. Furthermore, 0.175 00-2.800 00 g/L betaxolol elevated the plasma membrane permeability of HCEP cells, induced DNA fragmentation, chromatin condensation, and apoptotic body formation as well. In conclu- sion, betaxolol at doses ranging from 0. 175 00 to 2. 800 00 g/L has significant cytotoxicity to HCEP cells in dose- and time-dependent manners, which is realized by inducing apoptosis in these cells, suggesting the inescapable sever cyto- toxic side effect of betaxolol in eye clinic.