Shenzhen Key Laboratory of Ophthalmology, Ocular Trauma Treatment and Stem Cell Differentiation Public Service Platform of Shenzhen, Shenzhen Eye Hospital, Affiliated Shenzhen Eye Hospital of Jinan University, Shenzhen, 518040, China.
Exp Eye Res. 2018 Aug;173:44-50. doi: 10.1016/j.exer.2018.04.008. Epub 2018 Apr 19.
This study evaluated whether lithium chloride (LiCl) prevents cytoplasmic accumulation of mutant-transforming growth factor β-induced protein (Mut-TGFBI) in granular corneal dystrophy (GCD) via activation of the autophagy pathway. Levels of TGFBI and microtubule-associated protein 1A/1B-light chain 3 (LC3) in 3 GCD patients and healthy controls were analyzed by immunohistochemistry (IHC) staining and Western blot. Primary corneal fibroblasts were isolated and transfected with wild type or mutant type TGFBI over-expressed vectors, and then treated with LiCl and/or autophagy inhibitor 3-methyladenine (3-MA). Then, levels of TGFBI, glycogen synthase kinase-3 (GSK-3) and LC3-I/-II were detected. Cell viability and transmission electron microscopy assay were also performed. Levels of TGFBI and LC3 were significantly increased in GCD patients. Over-expression of mutant type TGFBI inhibited cell viability and induced autophagy in corneal fibroblasts. LiCl downregulated the expression of TGFBI in mutant type TGFBI over-expressed cells in a dose- and time-dependent manner. LiCl enhanced autophagy in mutant type TGFBI over-expressed cells and recovered cell viability in those cells. However, the effects of LiCl were partly attenuated when autophagy was suppressed by 3-MA. To summarize, treatment with LiCl inhibited the expression of TGFBI and recovery the inhibitory of mutant type TGFBI in cell viability, at least part through enhancing of autophagy. These data strongly suggest that LiCl may be useful in the treatment of GCD.
本研究评估了氯化锂（LiCl）是否通过激活自噬途径来防止颗粒状角膜营养不良（GCD）中突变转化生长因子β诱导蛋白（Mut-TGFBI）的细胞质积累。通过免疫组织化学（IHC）染色和 Western blot 分析 3 名 GCD 患者和健康对照者的 TGFBI 和微管相关蛋白 1A/1B-轻链 3（LC3）水平。分离原代角膜成纤维细胞并转染野生型或突变型 TGFBI 过表达载体，然后用 LiCl 和/或自噬抑制剂 3-甲基腺嘌呤（3-MA）处理。然后，检测 TGFBI、糖原合酶激酶-3（GSK-3）和 LC3-I/-II 的水平。还进行了细胞活力和透射电子显微镜检测。GCD 患者的 TGFBI 和 LC3 水平显着增加。突变型 TGFBI 的过表达抑制了角膜成纤维细胞的活力并诱导了自噬。LiCl 以剂量和时间依赖的方式下调突变型 TGFBI 过表达细胞中 TGFBI 的表达。LiCl 增强了突变型 TGFBI 过表达细胞中的自噬并恢复了这些细胞的活力。然而，当自噬被 3-MA 抑制时，LiCl 的作用部分减弱。总之，LiCl 的治疗抑制了 TGFBI 的表达，并恢复了突变型 TGFBI 对细胞活力的抑制作用，至少部分是通过增强自噬来实现的。这些数据强烈表明 LiCl 可能对 GCD 的治疗有用。
