颅内动脉瘤大鼠不同组织中端粒长度与动脉瘤大小的相关性

Comparison of telomere length in different tissues of IA model rats and its correlation with IA size

目的探讨颅内动脉瘤(intracranial aneurysm,IA)大鼠不同组织中端粒长度变化及其与IA大小相关性。方法SD大鼠随机分为2组(n=25),即对照组和IA组,手术造模。术后6个月,采集SD大鼠组织标本,包括血液、皮肤、肌肉组织、心肌、主动脉、脾脏及肾脏的组织标本。血管铸型观察颅内动脉瘤发病情况。提取各标本基因组DNA,实时荧光定量PCR法测算端粒长度,并将不同部位组织的端粒长度与IA形成情况进行相关性分析。结果IA组共有20只(80%)大鼠形成了动脉瘤,其中17只(68%)形成了Ⅱ期或Ⅲ期瘤体,5只(20%)为多发动脉瘤,共形成28处瘤体。IA组大鼠心肌组织和主动脉组织端粒长度增加,血液中细胞端粒长度显著缩短,差异有统计学意义(P<0.05)。IA组大鼠中,仅脾脏组织和骨骼肌组织端粒长度呈负相关(r=-0.515,P<0.05),心肌组织端粒长度与IA大小呈正相关(r=0.585,P=0.014)。结论在IA大鼠体内,外周血细胞端粒长度缩短,主动脉组织端粒长度增加,心肌细胞端粒长度增加且与IA大小呈正相关;端粒长度在不利因素作用下的变化趋势及程度具有组织特异性。

Objective To investigate the changes of telomere length in different tissues of intracranial aneurysm(IA)rats and its correlation with IA size.Methods SD rats were randomly divided into 2 groups(n=25),namely the control group and the IA model group.At 6 months postoperatively,specimens were collected after intraperitoneal injection of pentobarbital sodium,including blood specimens,skin specimens,muscle tissue,myocardium,aorta,spleen and kidney tissue specimens.The myocardium,aorta,spleen and kidney tissue were taken after the completion of the blood vessel casting.The vascular cast was performed to observe the incidence of intracranial aneurysms.The genomic DNA of each specimen was extracted,the telomere length was measured by real-time fluorescent quantitative PCR,and the telomere length of different tissues was correlated with the formation of IA.Results 20(80%)rats in the model group formed aneurysms,of which 17(68%)rats formed stageⅡorⅢtumors,five(20%)rats in the model group were multiple aneurysms,forming 28 aneurysms.In IA model group,the telomere length of myocardial tissue and aorta increased,and the telomere length of cells in blood decreased significantly(P<0.05).In the IA model group,the telomere length of spleen tissue were negatively correlated with skeletal muscle tissue(r=-0.515,P<0.05),while the telomere length of cardiac muscle was positively correlated with IA size(r=0.585,P=0.014).Conclusion In IA model rats,the telomere length of peripheral blood cells is shortened,the telomere length of aortic tissue increases,and the telomere length of cardiomyocytes increases,which is positively correlated with the size of IA.The change trend and degree of telomere length under the action of adverse factors are tissue-specific.