Yuan Ying, Li Min, Chen Qingzhong, Me Rao, Yu Yunjie, Gu Qing, Shi Guangsen, Ke Bilian
a Department of Ophthalmology , Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China.
b Shanghai Key Laboratory of Fundus Disease , Shanghai , China.
Curr Eye Res. 2018 Feb;43(2):200-207. doi: 10.1080/02713683.2017.1390770. Epub 2017 Nov 14.
Scleral remodeling causes the excessive ocular elongation that underlies myopia. Lysyl oxidase (LOX), a copper-containing amine oxidase, can catalyze collagen and elastin crosslinking. The purpose of this study was to investigate the role of LOX in scleral remodeling in form-deprivation myopia (FDM).
Seventy-five guinea pigs were randomly divided into five groups as follows: a normal control group, an FDM group, an FDM plus β-aminopropionitrile (BAPN) group, an FDM plus TGF-β1 (TGF-β1) group, and an FDM plus vehicle group. A translucent diffuser was used to induce FDM, and intravitreal injection was used to administer BAPN, TGF-β1 or vehicle. The scleral LOX and collagen gene and protein levels and the posterior scleral ultrastructure and biomechanics were measured.
In the FDM group, both the scleral LOX and collagen gene and protein levels were significantly lower than those in the control eyes. The collagen fibril diameters were significantly decreased in the FDM group compared with the diameters in the control group. A significant decrease in LOX gene and protein expression was observed after BAPN injection, and an increase was observed after TGF-β1 treatment compared with the levels in the FDM group. Additionally, the scleral collagen fibrils were significantly decreased in the BAPN-treated eyes but increased in the TGF-β1-treated eyes compared with the FDM eyes. The ultimate stress and Young's modulus of the sclera were lowest in the BAPN group, followed by the FDM group and the TGF-β1 group. The ultimate strain (%) of the sclera was lowest in the TGF-β1 group, followed by the FDM group and the BAPN group.
LOX expression was significantly lowered in myopic sclera. Modulating LOX expression induced a change in both the scleral collagen fibril diameter and the scleral biomechanics. Therefore, LOX may play a key role in the myopia scleral remodeling procedure.
巩膜重塑会导致引起近视的眼轴过度伸长。赖氨酰氧化酶（LOX）是一种含铜胺氧化酶，可催化胶原蛋白和弹性蛋白交联。本研究旨在探讨LOX在形觉剥夺性近视（FDM）巩膜重塑中的作用。
75只豚鼠随机分为五组：正常对照组、FDM组、FDM加β-氨基丙腈（BAPN）组、FDM加转化生长因子-β1（TGF-β1）组和FDM加溶媒组。使用半透明扩散器诱导FDM，并通过玻璃体腔注射给予BAPN、TGF-β1或溶媒。测量巩膜LOX、胶原蛋白基因和蛋白水平以及后极部巩膜超微结构和生物力学。
在FDM组中，巩膜LOX、胶原蛋白基因和蛋白水平均显著低于对照眼。与对照组相比，FDM组的胶原纤维直径显著减小。注射BAPN后，LOX基因和蛋白表达显著降低，与FDM组相比，TGF-β1治疗后表达增加。此外，与FDM眼相比，BAPN治疗组的巩膜胶原纤维显著减少，而TGF-β1治疗组的巩膜胶原纤维增加。巩膜的极限应力和杨氏模量在BAPN组中最低，其次是FDM组和TGF-β1组。巩膜的极限应变（%）在TGF-β1组中最低，其次是FDM组和BAPN组。
近视巩膜中LOX表达显著降低。调节LOX表达可引起巩膜胶原纤维直径和巩膜生物力学的改变。因此，LOX可能在近视巩膜重塑过程中起关键作用。
