摘要
目的研究低氧预适应对光损伤后小鼠视网膜光感受器细胞的保护作用,并探讨其可能的基因调控机制。方法将54只BALB/c小鼠随机分成单纯光照组、低氧预适应组和正常对照组,并将前两组动物在自制光照箱中连续光照3h,制成光损伤动物模型。应用光镜、核苷酸末端转移酶介导的dUTP缺口标记法观察各组小鼠视网膜组织结构的改变;应用免疫组织化学方法检测各组小鼠视网膜cfos和caspase1的表达。结果单纯光照组小鼠视网膜组织学改变出现的早且明显,光照后视网膜出现不同程度的病理学改变,且损伤主要发生在光感受器细胞层。随着光照后时间的延长,光感受器细胞凋亡数增加,视网膜光损伤逐渐加重,cfos和caspase1在该层出现了不同程度的阳性表达;低氧预适应组同单纯光照组相比,各时间段损伤均较轻,视网膜光感受器细胞层明显得到了保护,同单纯光照组比较,caspase1的阳性表达明显减少,而cfos无明显变化;正常对照组小鼠视网膜组织结构层次清楚,外核层排列规则,无cfos和caspase1的阳性表达。结论低氧预适应通过抑制凋亡相关基因的表达而对光感受器细胞有神经保护作用,且caspase1参与了低氧预适应的保护机制。
Objective To study the protective roles of hypoxic preconditioning in light induced retinal injury in a mice model and investigate the possible mechanism of related gene regulation. Methods 54 BALB/c mice were randomly divided into simple light exposure group(SL), hypoxic pretreatment group (HP) and control group(CON). The mice of SL and HP were continually exposed to light for 3 h, which built model of light-induced damage. Morphologic changes of photoreceptor cells in different group were examined by light microscope and the apoptosis was detected by TdT-mediated dUTP nick end labeling. Different expressions of c-fos and caspase-1 gene were examined by immunohistochemical staining. Results In group SL, the photic injury appeared very obviously and early. Different changes appeared in the outer nuclear layer after light exposure. Photic injury was aggravated flollwing the increased light exposure. Positive staining of c-fos and caspase-1 could be seen in the outer nuclear layer. In group HP, the changes of retinal morphology appeared slightly and lately.Compared with group SL, caspsae-1 expression was decreased obviously, while no difference was seen in the expression of c-fos . the retinal structures was normal in the mice of control group and c-fos and caspase-1 were stained negative. Conclusion Hypoxic preconditioning has neuroprotective effect on photoreceptor cells by inhibiting the expression of apoptosis-related genes in photic injured mice model. caspase-1 may be involved in the protective mechanism.
出处
《中华眼科杂志》
CAS
CSCD
北大核心
2005年第7期631-635,共5页
Chinese Journal of Ophthalmology
