TERT在视网膜新生血管模型中的动态表达及与Bcl-2的关系

Dynamic expression of TERT in a model of retinal neovascularization and its relationship with Bcl-2

目的观察小鼠视网膜新生血管(retinal neovascularization,RNV)模型中端粒酶逆转录酶(telomerase reverse transcriptase,TERT)的动态表达以及与抗凋亡基因Bcl-2表达的关系,验证TERT对RNV形成的重要作用。方法选择生后7d龄C57BL/6J小鼠50只随机分为高氧模型组、正常对照组,每组25只,高氧模型组置于体积分数75%±2%高氧环境中生活5d,然后正常氧环境中饲养。正常对照组小鼠置于正常氧环境中饲养。于生后19d、24d、27d、30d,用20g.L-1伊凡思蓝灌注进行视网膜铺片,观察各组小鼠视网膜血管形态变化;RT-PCR检测各组生后19d、24d、30d TERTmRNA的表达变化及生后19d各组Bcl-2mRNA的表达变化。结果灌注铺片显示,高氧模型组生后19d RNV最多,生后21-30d RNV逐渐减少。RT-PCR显示高氧模型组小鼠视网膜TERT mRNA灰度比值19-30d逐渐减少,生后19d(1.03±0.07)与30d(0.59±0.07)差异有统计学意义(t=8.232,P=0.010);生后19d,高氧模型组Bcl-2mRNA灰度值为1.25±0.14,明显高于正常对照组的0.48±0.26(t=4.505,P=0.011)。结论TERT基因对RNV形成起重要调控作用,RNV的形成可能与抗凋亡基因Bcl-2高表达有关。

Objective To study the dynamic expression of telomerase reverse transcriptase （TERT） in a mouse model of retinal neovascularization （RNV） and its relationship with expression of Bcl-2 to identify its effect on RNV. Methods Fifty postnatal 7 days C57BL/6J mice were divided into hyperxia model group and control group ,25 in each group. In hyperxia model group ,mice were exposed to volume fraction 75% ± 2% oxygen for 5 days and then to room air;In control group, mice were raised in room air. The mice＇ s retina stretched preparation was made with 20 g · L^-1 Evens blue solution at postnatal 19 days, 24 days, 27 days, 30 days, respectively, and the morphologic changes of retinal vessel were observed. With RT-PCR, the expression of TERT mRNA was carefully detected at postnatal 19 days, 24 days, 30 days in hyperxia model group, and Bcl-2 mRNA was detected in both groups at postnatal 19 days. Results Perfusion stretched preparation showed RNV was most at postnatal 19 days and gradually decreased from postnatal 21 days to 30 days in hyperxia model group. RT-PCR showed gray scale of TERT mRNA was gradually decreased from postnatal 19 days to 30 days in hyperxia model group,and there was significant difference between that at postnatal 19 days （ 1. 03 ± 0.07 ） and that at postnatal 30 days （ 0.59±0.07 ） （ t = 8. 232, P = 0. 010 ）. At postnatal 19 days, the expression of Bcl-2 mRNA in hyperxia model group （ 1.25 ± 0.14 ） was noticeably higher than that in control group（0.48 ±0.26） （ t =4. 505,P =0. 011 ）. Conclusion TERT may have an effect on the development of the RNV and it may be related to anti-aoootosis Bc1-2 gene.