哺乳动物雷帕霉素靶蛋白在脑动静脉畸形中的表达及其对病灶血管内皮组织增殖与凋亡的影响

Expression of mammalian target of rapamycin in brain arteriovenous malformation and its effect on proliferation and apoptosis of nidal vascular endothelium

目的观察哺乳动物雷帕霉素靶蛋白(mTOR)在脑动静脉畸形(bAVM)中的表达情况及其对bAVM病灶血管内皮组织增殖与凋亡的影响,并尝试探索与bAVM中mTOR表达量相关的基线因素。方法收集河南省人民医院神经外科2019年6月至2020年12月行单纯外科切除的16例bAVM患者的基线资料[性别、年龄、畸形病灶出血史及Spezler-Martin(S-M)分级等]及bAVM病理标本,同时于病理科获取4例颅外伤患者的正常颞浅动脉标本。应用苏木素-伊红(HE)及Masson染色观察bAVM组织病理特征,免疫组织化学检测mTOR及血管内皮生长因子A(VEGFA)、Ki-67、含半胱氨酸的天冬氨酸蛋白水解酶3(Caspase-3)表达水平并以累积吸光度(IOD)值表示。比较bAVM血管内皮组织与正常颞浅动脉内皮组织mTOR及VEGFA、Ki-67、Caspase-3的表达水平。采用线性相关分析方法分析mTOR与VEGFA、Ki-67、Caspase-3的相关性及年龄对其表达水平的影响。采用单因素分析方法评估不同bAVM病灶出血史、S-M分级及性别间mTOR表达水平。结果所有bAVM标本的HE及Masson染色结果均可见典型的畸形血管组织。免疫组织化学分析结果显示,mTOR主要定位于bAVM内皮组织,bAVM中mTOR、Ki-67、VEGFA、Caspase-3表达量均较正常颞浅动脉显著增加[IOD分别为(157.5±88.2)比(36.5±4.9)、(60.9±29.2)比(20.3±4.5)、(60.4±50.7)比(22.0±6.8)、(28.6±25.2)比(5.3±1.4);P值分别为0.030、<0.01、0.041、0.001],其中VEGFA、Ki-67与mTOR表达量呈正相关(R^(2)值分别为0.581、0.312,均P<0.05),而Caspase-3表达量与mTOR表达量呈负相关(R^(2)=0.249,P=0.049)。mTOR表达量随患者年龄增加逐渐降低,二者呈显著负相关(R^(2)=0.320,P=0.022);患者既往是否有出血史、不同S-M分级(Ⅱ级,Ⅲ级)及不同性别间mTOR表达量差异均无统计学意义(均P>0.05)。结论mTOR主要高表达于bAVM血管内皮组织,可能与bAVM病灶内皮组织的增殖与凋亡活动密切相关;mTOR在bAVM血管内皮组织中的表达量与患者年龄有关,而与S-M分级、出血史及性别无关。

Objective To observe the expression of mammalian target of rapamycin(mTOR)in brain arteriovenous malformation(bAVM)and its effect on vascular proliferation and apoptosis in bAVM lesions.Exploreing the clinical factors affecting mTOR expression in bAVM.Methods The baseline data of 16 bAVM patients including the gender,age,history of abnormal lesions bleeding and Spezler-Martin(S-M)grade and the pathological specimens of bAVM resected by surgery alone from June 2019 to December 2020 in the Department of Neurosurgery,Henan Provincial People′s Hospital were collected.The normal temporal shallow arteries specimens of the patients with cranial trauma from the Department of Pathology were collected.The hematoxylin-eosin(HE)and Masson staining were used to observe the histopathological features of bAVM.Immunohistochemistry was used to count the expression of mTOR,vascular endothelial growth factor A(VEGFA),Ki-67 and cysteinyl aspartate specific proteinase 3(Caspase-3)and integrated optical density(IOD)analysis was used to quantify them.The expression of mTOR,VEGFA,Ki-67 and Caspase-3 were compared between the bAVM endothelial tissue and normal temporal shallow artery endothelial tissue.The relationship between mTOR and VEGFA,Ki-67,Caspase-3,age were analyzed with linear correlation analysis.Finally,the expression of mTOR between bleeding history or not,S-M grade(Ⅱ,Ⅲ),male and female were compared.Results Typical malformed vascular tissue was observed in HE and Masson staining results of all bAVM specimens.Immunohistochemistry showed that mTOR was mainly localized in bAVM endothelial tissue,and the expression levels of mTOR,Ki-67,VEGFA and Caspase-3 in bAVM endothelial tissue were significantly increased compared with normal temporal shallow artery([157.5±88.2]vs.[36.5±4.9],[60.9±29.2]vs.[20.3±4.5],[60.4±50.7]vs.[22.0±6.8],[28.6±25.2]vs.[5.3±1.4];P value was 0.030,<0.01,0.041,0.001,respectively).Among them,VEGFA and Ki-67 were significantly positively correlated with mTOR expression(R^(2)=0.581 and 0.312,respectively,both P<0.05),while Caspase-3 expression was negatively correlated with mTOR expression(R^(2)=0.249,P=0.049).The mTOR expression gradually decreased with increasing patient age,and there was a significant negative correlation between the two(R^(2)=0.320,P=0.022).There was no significant difference in mTOR expression of bAVM patients between previous bleeding history or not,S-M grade(Ⅱ,Ⅲ)and male and female(all P>0.05).Conclusion The mTOR is mainly expressed in vascular endothelium of bAVM and is significantly correlated with endothelial proliferation and apoptosis,and the expression of mTOR in bAVM tissues was related to patient age,but not to S-M grade,bleeding history and gender.