青蒿琥酯对大鼠实验性视网膜分支静脉阻塞的抑制作用

Inhibitory effect of artesunate on experimental branch retinal vein occlusion in rats

目的探讨青蒿琥酯(Art)对大鼠实验性视网膜分支静脉阻塞(BRVO)的抑制作用。方法取SPF级雌性Wistar大鼠150只,将动物随机分为6组,每组25只,右眼为实验眼:空白对照组、模型对照组(玻璃体内注射生理盐水)、康柏西普组、Art高浓度(50.0 mg·L^(-1))组、Art中浓度(25.0 mg·L^(-1))组、Art低浓度(12.5 mg·L^(-1))组;空白对照组采用未造模大鼠进行实验,其他各组采用BRVO模型大鼠进行实验。采用光化学法建立大鼠BRVO模型。模型建立后行玻璃体内注射给药,注药后1 d、3 d、7 d及14 d行眼底照相观察血管阻塞、视网膜水肿情况;行HE染色观察视网膜组织形态,并测量视网膜内层厚度;实时荧光定量PCR检测视网膜组织VEGF、HIF-1αmRNA表达情况。结果玻璃体内注药后1 d,模型对照组,康柏西普组,Art高、中、低浓度组大鼠出现视网膜静脉阻塞、迂曲扩张及视网膜出血水肿表现。玻璃体内注药后7 d,康柏西普组和Art高、中、低浓度组大鼠视网膜静脉再通,仅有小部分静脉血管阻塞;而康柏西普组和Art高、中、低浓度大鼠视网膜静脉阻塞表现差异不明显。玻璃体内注药后7 d,模型对照组大鼠视网膜组织水肿,其中神经纤维层与内丛状层水肿明显,视网膜神经节细胞可见空泡样变性。康柏西普组和Art高、中、低浓度组大鼠视网膜水肿基本消失,视网膜神经节细胞空泡变性明显改善。玻璃体内注药后3 d、7 d、14 d,康柏西普组,Art高、中、低浓度组大鼠视网膜内层厚度明显小于模型对照组(均为P<0.05)。玻璃体内注药后1 d、3 d,模型对照组大鼠视网膜组织HIF-1αmRNA相对表达量较空白对照组均升高(均为P<0.05);注药后7 d,HIF-1αmRNA相对表达量则降低(P<0.05)。注药后1 d、3 d,康柏西普组,Art高、中、低浓度组大鼠视网膜组织HIF-1αmRNA相对表达量较模型对照组均降低(均为P<0.05)。玻璃体内注药后7 d、14 d,模型对照组大鼠视网膜组织VEGF mRNA的相对表达量较空白对照组均升高(均为P<0.05);康柏西普组,Art高、中、低浓度组VEGF mRNA的相对表达量较模型对照组均降低(均为P<0.05)。结论Art可以减轻BRVO大鼠视网膜损伤程度,其机制可能与调控HIF-1α/VEGF信号通路有关。

Objective To investigate the inhibitory effect of artesunate(Art)on experimental branch retinal vein occlusion(BRVO)in rats.Methods A total of 150 healthy SPF female Wistar rats(with the right eye being the experimental eye)were selected and randomly divided into six groups:blank control group,model control group(intravitreal injection of normal saline),Conbercept group,Art high concentration group(50.0 mg·L^(-1)),Art medium concentration group(25.0 mg·L^(-1)),and Art low concentration group(12.5 mg·L^(-1)),with 25 rats in each group.Rats in the blank control group were not modeled,while rats in the other groups were modeled with BRVO by laser photocoagulation and intravitreally injected with different drugs.On the 1st,3rd,7th,and 14th days after intervention,vascular occlusion and retinal edema were observed by fundus photography,the morphology of the retinal tissue was evaluated and the thickness of the retinal inner layer was measured by hematoxylin-eosin staining,and the mRNA expression of vascular endothelial growth factor(VEGF)and hypoxia-inducible factor-1α(HIF-1α)was determined by quantitative real-time polymerase chain reaction.Results One day after intravitreal injection,rats in the model control group,Conbercept group,and Art high,medium and low concentration groups showed retinal vein occlusion,tortuosity and dilatation,and retinal hemorrhage and edema.On the 7th day after intravitreal injection,the retinal veins of rats in the Conbercept group and the Art high,medium and low concentration groups were recanalized,except that a small part of the veins was still obstructed.There was no significant difference in retinal vein occlusion between the Conbercept group and the Art high,medium and low concentration groups.On the 7th day after intravitreal injection,the retinal tissue,especially the nerve fiber layer and the inner plexiform layer of rats in the model control group,showed edema,and vacuolar degeneration was observed in retinal ganglion cells;the retinal edema of rats in the Conbercept group and the Art high,medium and low concentration groups almost disappeared,and the vacuolar degeneration in retinal ganglion cells significantly improved.On the 3rd,7th and 14th days after intravitreal injection,the thickness of the retinal inner layer in the Conbercept group and the Art high,medium and low concentration groups significantly reduced when compared with the model control group(all P<0.05).On the 1st and 3rd days after intravitreal injection,the expression of HIF-1αmRNA in the model control group significantly increased when compared with the blank control group(both P<0.05),while decreased on the 7th day after intravitreal injection(P<0.05).On the 1st and 3rd days after intravitreal injection,the expression of HIF-1αmRNA in the Conbercept group and the Art high,medium and low concentration groups remarkably reduced when compared with the model control group(both P<0.05).On the 7th and 14th days after intravitreal injection,the expression of VEGF mRNA in the model control group was higher than that in the blank control group(both P<0.05),while the expression of VEGF mRNA in the Conbercept group and the Art high,medium and low concentration groups was lower than that in the model control group(all P<0.05).Conclusion Art can effectively alleviate retinal injury in BRVO rats,which may be related to its regulation of the HIF-1α/VEGF signaling pathway.