Tian Cheng-Lei, Wen Qian, Fan Ting-Jun
Laboratory for Corneal Tissue Engineering, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
Laboratory for Corneal Tissue Engineering, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
Exp Toxicol Pathol. 2015 Oct;67(10):517-24. doi: 10.1016/j.etp.2015.07.006. Epub 2015 Aug 19.
Atropine is an anticholinergic drug for mydriasis in eye clinic, and its abuse might be cytotoxic to the cornea and result in blurred vision. However, the cytotoxicity of atropine to the cornea and its cellular and molecular mechanisms remain unknown. In this study, we investigated the cytotoxicity of atropine to corneal epithelium and its underlying mechanisms using an in vitro model of non-transfected human corneal epithelial (HCEP) cells. Our results showed that atropine, above the concentration of 0.3125 g/l (1/32 of its therapeutic dosage in eye clinic), had a dose- and time-dependent toxicity to HCEP cells by inducing morphological abnormality, cytopathic effect, viability decline, and proliferation retardation. Moreover, the proliferation-retarding effect of atropine on the cells was achieved by inducing G1/S phase arrest and downregulation of E-cadherin and β-catenin. Besides, atropine also had an apoptosis-inducing effect on the cells by inducing phosphatidylserine externalization, plasma membrane permeability elevation, DNA fragmentation and apoptotic body formation. Furthermore, atropine could also induce activations of caspase-2, -3 and -9, disruption of mitochondrial transmembrane potential, downregulation of Bcl-2 and Bcl-xL, upregulation of Bax and Bad, and upregulation of cytoplasmic cytochrome c and apoptosis-inducing factor, implying a death receptor-mediated mitochondrion-dependent pathway is most probably involved in the apoptosis of HCEP cells induced by atropine. Taken together, our results suggest that atropine has remarkable cytotoxicity to HCEP cells by inducing cell cycle arrest and death receptor-mediated mitochondrion-dependent apoptosis.
阿托品是眼科诊所用于散瞳的抗胆碱能药物，其滥用可能对角膜具有细胞毒性并导致视力模糊。然而，阿托品对角膜的细胞毒性及其细胞和分子机制仍不清楚。在本研究中，我们使用未转染的人角膜上皮（HCEP）细胞的体外模型研究了阿托品对角膜上皮的细胞毒性及其潜在机制。我们的结果表明，浓度高于0.3125 g/l（其眼科临床治疗剂量的1/32）时，阿托品通过诱导形态异常、细胞病变效应、活力下降和增殖迟缓，对HCEP细胞具有剂量和时间依赖性毒性。此外，阿托品对细胞的增殖抑制作用是通过诱导G1/S期阻滞以及下调E-钙黏蛋白和β-连环蛋白实现的。此外，阿托品还通过诱导磷脂酰丝氨酸外翻、质膜通透性升高、DNA片段化和凋亡小体形成，对细胞产生凋亡诱导作用。此外，阿托品还可诱导半胱天冬酶-2、-3和-9的激活、线粒体跨膜电位的破坏、Bcl-2和Bcl-xL的下调、Bax和Bad的上调以及细胞质细胞色素c和凋亡诱导因子的上调，这意味着死亡受体介导的线粒体依赖性途径很可能参与了阿托品诱导的HCEP细胞凋亡。综上所述，我们的结果表明，阿托品通过诱导细胞周期阻滞和死亡受体介导的线粒体依赖性凋亡，对HCEP细胞具有显著的细胞毒性。
