METHODS: The 12-month-old healthy M. fortis were served as a control group and 12-month-old cataractous M. fortis were served as an experimental group. The lens transparency was observed using the slit-lamp biomicroscope. Hematoxylin and eosin staining was used to detect pathological changes in the lens. Biochemical detection methods were applied to detect blood routine, blood glucose levels, the serum activities of superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) in both groups. Finally, real-time RT-PCR was used to detect the transcription levels of cataract-related genes in the lens of 2 groups.
RESULTS: Compared with the control group, the lens of cataract M. fortis showed severely visible opacity, the structure of lens was destroyed seriously, and some pathological damage, such as swelling, degeneration/necrosis, calcification, hyperplasia, and fiber liquefaction were found in lens epithelial cells (LECs). The fibrous structure was disorganized and irregularly distributed with morgagnian globules (MGs) aggregated in the degenerated lens fibers. There was no statistically significant difference in blood glucose levels between the experimental and control groups (P>0.05). However, white blood cell (WBC) count (P<0.05), lymphocyte count (P<0.01), and lymphocyte ratio (P<0.05) were significantly decreased, while neutrophil percentage (P<0.05) and monocyte ratio (P<0.01) were significantly increased. The serum activities of SOD and GSH-Px (both P<0.05) were both reduced. The mRNAs of cataract-related genes, including CRYAA, CRYBA1, CRYBB3, Bsfp1, GJA3, CRYBA2, MIP, HspB1, DNase2B, and GJA8, were significantly downregultaed in the lenses of the experimental group (all P<0.05).
CONCLUSIONS: There are significant differences in lens pathological changes, peroxidase levels, and cataract-related gene expression between cataract and healthy M. fortis. The developed cataract spontaneously in M. fortis is closely related to age, the cataract M. fortis might be an ideal animal model for the research of age-related cataract.
目的: 年龄相关性白内障是成人白内障中最常见的类型,也是主要的致盲眼科疾病。目前关于年龄相关性白内障动物模型的建立报道较少。本课题组在东方田鼠实验动物化培育过程中首次发现12~15月龄东方田鼠能自然发生白内障。本研究通过对东方田鼠自发性白内障进行鉴定分析,探讨其发展成为年龄相关性白内障动物模型的可能性。方法: 分别选用12月龄健康东方田鼠为对照组和12月龄白内障东方田鼠为实验组。通过裂隙灯生物显微镜观察晶状体透明度;苏木精-伊红染色观察东方田鼠的晶状体病理变化;生物化学方法测定2组东方田鼠的血常规、血糖水平及血清中超氧化物歧化酶(superoxide dismutase,SOD)和谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活性。最后通过实时反转录聚合酶链反应(real-time reverse transcription PCR,real-time RT-PCR)检测2组东方田鼠晶状体中白内障发病相关基因的转录水平。结果: 与对照组比较,实验组东方田鼠的晶状体呈现不同程度的浑浊,晶状体结构被严重破坏,晶状体上皮细胞出现明显肿胀、大量空泡、变性/坏死、钙化、增生和纤维液化等病理变化,纤维结构紊乱,分布不规则,变性的晶状体纤维中有马氏小体聚集。与对照组比较,实验组东方田鼠的血糖水平差异无统计学意义(P>0.05),白细胞数量(P<0.05)、淋巴细胞数量(P<0.01)、淋巴细胞比率(P<0.05)均显著降低,而中性粒细胞百分比(P<0.05)和单核细胞比率(P<0.01)均显著增加,血清中SOD和GSH-Px活性均降低(均P<0.05);实验组东方田鼠晶状体中白内障发病相关基因CRYAA、CRYBA1、CRYBB3、Bsfp1、GJA3、CRYBA2、MIP、HspB1、DNase2B和GJA8的mRNA水平均显著降低(均P<0.05)。结论: 白内障东方田鼠与健康东方田鼠相比,晶状体病理变化、过氧化物酶水平和白内障相关基因表达均有显著差异。东方田鼠自发性白内障具有年龄相关性,白内障东方田鼠有望发展成为年龄相关性白内障研究的理想动物模型。.