Abstract：
Artificial light can affect eyeball development and increase myopia rate. Matrix metalloproteinase 2 (MMP-2) degrades the extracellular matrix, and induces its remodeling, while tissue inhibitor of matrix MMP-2 (TIMP-2) inhibits active MMP-2. The present study aimed to look into how refractive development and the expression of MMP-2 and TIMP-2 in the guinea pigs\' remodeled sclerae are affected by artificial light with varying spectral compositions. Three weeks old guinea pigs were randomly assigned to groups exposed to five different types of light: natural light, LED light with a low color temperature, three full spectrum artificial lights, i.e. E light (continuous spectrum in the range of ~390-780 nm), G light (a blue peak at 450 nm and a small valley 480 nm) and F light (continuous spectrum and wavelength of 400 nm below filtered). A-scan ultrasonography was used to measure the axial lengths of their eyes, every two weeks throughout the experiment. Following twelve weeks of exposure to light, the sclerae were observed by optical and transmission electron microscopy. Immunohistochemistry, Western blot and RT-qPCR were used to detect the MMP-2 and TIMP-2 protein and mRNA expression levels in the sclerae. After four, six, eight, ten, and twelve weeks of illumination, the guinea pigs in the LED and G light groups had axial lengths that were considerably longer than the animals in the natural light group while the guinea pigs in the E and F light groups had considerably shorter axial lengths than those in the LED group. Following twelve weeks of exposure to light, the expression of the scleral MMP-2 protein and mRNA were, from low to high, N group, E group, F group, G group, LED group; however, the expression of the scleral TIMP-2 protein and mRNA were, from high to low, N group, E group, F group, G group, LED group. The comparison between groups was statistically significant (p<0.01). Continuous, peaks-free or valleys-free artificial light with full-spectrum preserves remodeling of scleral extracellular matrix in guinea pigs by downregulating MMP-2 and upregulating TIMP-2, controlling eye axis elongation, and inhibiting the onset and progression of myopia.
摘要：
人工光可以影响眼球发育，增加近视率。基质金属蛋白酶2（MMP-2）降解细胞外基质，并诱导其重塑，而基质MMP-2的组织抑制剂（TIMP-2）抑制活性MMP-2。本研究旨在探讨不同光谱组成的人工光如何影响豚鼠重塑巩膜的屈光发育和MMP-2和TIMP-2的表达。将三周大的豚鼠随机分配到暴露于五种不同类型的光的组中：自然光，LED灯具有低色温，三个全光谱人造光，即E光（连续光谱在~390-780nm范围内），G光(在450nm处的蓝色峰和480nm处的小谷)和F光(连续光谱和400nm以下的波长过滤)。使用A扫描超声检查来测量他们眼睛的轴向长度，在整个实验中每两周。经过十二周的光照，通过光学和透射电子显微镜观察巩膜。免疫组织化学,Westernblot和RT-qPCR检测巩膜中MMP-2和TIMP-2蛋白和mRNA的表达水平。四点以后,六,八,十,和十二周的光照，LED和G灯组的豚鼠的轴向长度明显长于自然光组的动物,而E和F灯组的豚鼠的轴向长度明显短于LED组.经过十二周的光照，巩膜MMP-2蛋白和mRNA的表达,从低到高,N组,E组,F组,G组,LED组;然而,巩膜TIMP-2蛋白和mRNA的表达,从高到低,N组,E组,F组,G组,LED组。组间比拟有统计学意义(p<0.01)。连续,全谱无峰或无谷人造光通过下调MMP-2和上调TIMP-2，控制眼轴伸长，保留了豚鼠巩膜细胞外基质的重塑，并抑制近视的发生和发展。
