Sun Yi-Chen, Liou Hau-Min, Yeh Po-Ting, Chen Wei-Li, Hu Fung-Rong
Department of Ophthalmology, Taipei Tzu Chi Hospital, the Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan 2Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.
Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.
Invest Ophthalmol Vis Sci. 2017 Jul 1;58(9):3716-3722. doi: 10.1167/iovs.16-20998.
To determine the presence of monocarboxylate transporter (MCT) in human and rabbit corneal epithelium and its role in transcellular fluorescein transportation in the cornea.
The presence of MCTs in human and rabbit corneal epithelium was determined by RT-PCR and immunohistochemistry. Intracellular fluorescein uptake experiment was performed using cultured human corneal epithelial cells (HCECs). The involvement of MCT in fluorescein uptake was determined by addition of MCT inhibitors to HCECs and acute dry eye model on New Zealand albino rabbits by spectrophotometry, corneal impression cytology, and external eye photographs.
MCT-1 and MCT-4 were identified in both human and rabbit corneal epithelia. A longer treatment period and a lower pH value in culture medium increased fluorescein uptake in HCECs. Fluorescein uptake in HCECs was decreased following addition of MCT inhibitors in a concentration-dependent manner. Impression cytology under fluorescent microscopy showed intracellular fluorescein staining in the rabbit cornea with acute dry eye treatment that was decreased following topical treatment of MCT inhibitors.
Fluorescein ingress in corneal epithelial cells is mediated by the MCT family. Further study of MCT-mediated transport on HCECs may potentially benefit differential diagnosis and contribute better understandings of ocular surface disorders.
确定单羧酸转运体（MCT）在人及兔角膜上皮中的存在情况及其在角膜跨细胞荧光素转运中的作用。
采用逆转录聚合酶链反应（RT-PCR）和免疫组织化学方法检测人及兔角膜上皮中MCT的存在情况。使用培养的人角膜上皮细胞（HCECs）进行细胞内荧光素摄取实验。通过向HCECs中添加MCT抑制剂以及对新西兰白化兔建立急性干眼模型，采用分光光度法、角膜印片细胞学检查和眼部外观照片，确定MCT在荧光素摄取中的作用。
在人及兔角膜上皮中均鉴定出MCT-1和MCT-4。在HCECs中，延长处理时间和降低培养基pH值可增加荧光素摄取。添加MCT抑制剂后，HCECs中的荧光素摄取呈浓度依赖性降低。荧光显微镜下的印片细胞学检查显示，急性干眼处理后的兔角膜中有细胞内荧光素染色，局部应用MCT抑制剂后染色减少。
角膜上皮细胞中的荧光素进入是由MCT家族介导的。对HCECs上MCT介导的转运进行进一步研究可能有助于鉴别诊断，并有助于更好地理解眼表疾病。
