犬氧化损伤性白内障晶状体结构和TGF-β_1 mRNA表达的变化

Changes of lens structure and TGF-β_1 mRNA expression in oxidative-induced cataract of dogs

为了明确犬氧化损伤性白内障发展过程中晶状体结构的变化与转化生长因子β_1(TGF-β_1)mRNA表达的关系。本试验选取重庆本地杂交犬通过芬顿溶液进行晶状体囊袋内注射法建立犬氧化损伤性白内障模型,使用裂隙灯观察成模效果,借助光镜观察晶状体病理组织学变化,最后使用荧光定量PCR(real-time quantitative PCR)检测白内障发展过程中晶状体组织TGF-β_1基因的相对表达量。结果显示,随着犬氧化损伤性白内障发展,晶状体前囊膜下和赤道部晶状体上皮细胞(LECs)从Ⅰ期起大小、数量、形态、细胞核染色以及结构排列异常,发展到Ⅲ、Ⅴ期时LECs与前囊膜连接变的疏松;当犬白内障Ⅲ期向Ⅴ期发展时后囊膜与皮质区连接疏松,在Ⅴ期时前、后囊膜均破裂;在白内障Ⅴ期时位于赤道部周围皮质区的晶状体纤维连接疏松,出现断裂崩解,走向改变的现象。与空白对照组相比犬白内障Ⅱ、Ⅲ、Ⅳ期的TGF-β_1mRNA的表达水平均上调,差异极显著(P<0.01),且Ⅱ期和Ⅲ期表达水平显著高于其他白内障发展的3个时期(P<0.05),其中Ⅲ期最高,Ⅱ期其次。结果表明,犬氧化损伤性白内障发展过程中TGF-β_1mRNA呈高表达是晶状体上皮细胞(LECs)异常变化、囊膜的完整性遭到破坏而发生炎性反应,LECs的异常变化和TGF-β_1的高表达可能导致犬晶体纤维结构的病理变化。

To determine the relationsh in oxidative damage cataract, the mod ips between lens structure and expression of TGF-β1 mRNA el of oxidative damage cataract were established in Chongqing local hybrid canine by Fenton injection. The lens were checked by slit lamp, the structures of lens observed by light microscope. We used real-time quantitative PCR to determine the expression of TGF-β1 mRNA during different cataract phases. The result indicated that with the development of cataract, the LECs in anterior capsule and equator became abnormal from phase Ⅰ, the connection between LECs and anterior capsule became loose in phase Ⅲ and V ,the connection between posterior capsular and cortex also became loose from phase Ⅲ toV ,both anterior and posterior capsule broke in phase V , the cortex lens fiber around equator became loose connection, fracture and alignment change in phaseV. TGF-β1 mRNA expression was significantly increased（P〈0.01） in phase Ⅱ , Ⅲ and Ⅳ compared with the blank group,phase Ⅱ and Ⅲ had significant（P〈0.05） increase compared with cataract stage, the highest in phase Ⅲ,next phase Ⅱ. The result showed that high expression of TGF-β1 mRNA was related to abnormal changed LECs and damaged integrity of cap- sule,so the cverexpression of TGF-β1 and abnormal LECs may cause the pathological changes of lens fiber structure.