凋亡小分子探针在急性大脑中动脉栓塞和再通模型中的应用

Application of Apoptosis Small-Molecule Probe in Acute Middle Cerebral Artery Embolization and Recanalization Model

目的探讨凋亡小分子探针CYS-F在急性大脑中动脉栓塞和再通模型中活体分子成像的可行性,分析其反映病变程度的能力。材料与方法阿霉素诱导Hela细胞凋亡,体外验证探针靶向能力;模拟临床,构建小鼠急性大脑中动脉栓塞模型(n=15)和再通模型(n=15),行磁共振血管成像评估靶血管情况;经尾静脉注射CYS-F探究探针分布情况。建模24 h后,T2WI评估病灶体积,近红外成像活体评估细胞凋亡情况。采用尼氏染色和c-fos染色比较两组的差异。结果CYS-F有较好的体外细胞凋亡靶向能力。建模后多普勒血流仪和磁共振血管成像显示,栓塞组成功栓塞大脑中动脉,再通组大脑中动脉复通;近红外成像显示栓塞组大脑中动脉区域荧光信号缺失。建模24 h后,T2WI显示再通组梗死灶体积率明显小于栓塞组(0.055±0.015比0.512±0.220;t=19.761,P<0.001)。栓塞组荧光强度较再通组强,靶背景比分别为1.215±0.162、0.731±0.085(t=10.252,P<0.001)。栓塞组可见大量激活的神经元细胞表达c-fos蛋白,尼氏染色可见大量细胞发生核固缩和裂解。结论小鼠急性大脑中动脉栓塞模型和再通模型贴近临床,应用CYS-F小分子探针可在体对细胞凋亡成像,反映梗死程度,且能在注射初期反映局部组织血流灌注情况。

Purpose To investigate the feasibility of apoptosis small-molecule probe CYS-F for in vivo molecular imagingin acute middle cerebral artery embolization and recalculation models,and to explore its abilityto reflect lesions.Materials and Methods Hela cell apoptosis was induced by Adriamycin,and the targeting ability of the probe was verified in vitro.Clinical middle cerebral artery embolization was simulated,acute ischemic stroke model(n=15)and recanalization model(n=15)were constructed,and the vessels were evaluated by magnetic resonance angiography imaging.The distribution of CYS-F was investigated by injecting the probe into the caudal vein.24 hours after modeling,the lesion volume rate was assessed on T2WI,and apoptosis was assessed in vivo by near infrared imaging.Niss and c-fos staining were used to compare the differences between the two groups.Results CYS-F showed a good ability to target apoptosis in vitro.After modeling,Doppler flowmeter and magnetic resonance angiography showed that the middle cerebral artery was successfully embolized in the embolization group,and the artery was recanalized in the recanalization group.Near infrared imaging showed the loss of fluorescence signal in the middle cerebral artery region in the embolized group.24 hours after modeling,T2WI showed that the infarct volume rate in the recanalization group was significantly lower than that in the embolization group(0.055±0.015 vs.0.512±0.220;t=19.761,P<0.001).The fluorescence intensity of the embolization group was significantly stronger than that of the recusing group,the target to background ratio was 1.215±0.162 and 0.731±0.085,respectively(t=10.252,P<0.001).In the embolization group,a large number of activated neurons expressed c-fos protein,and a large number of cells underwent nuclear condensation and lysis by Niss staining.Conclusion The acute embolization model and recalculation model of middle cerebral artery in mice are close to the clinic.CYS-F can be used to image apoptosis in vivo,reflect the lesion degree,and reflect the local tissue blood perfusion at the initial stage of injection.