【摘要】 目的　探讨在短暂、局灶性脑缺血后 ,脂质体介导的外源基因能否在大鼠脑组织中有效的表达。方法　将大鼠一侧大脑中动脉栓塞 1h以制作短暂、局灶性脑缺血模型。根据行为实验来判定模型制作是否成功。将含报告基因LacZ的质粒和脂质体的复合体注入实验组大鼠的脑脊液中 ,对照组只注射脂质体。 7d后取动物脑组织 ,通过组织化学和逆转录酶 多聚酶链反应 (RT PCR)等方法来鉴定外源基因是否表达。结果　转染LacZ基因的缺血性脑损伤大鼠脑组织中 ,其表达产物 β 半乳糖苷酶在皮质、皮质下区域的细胞及脉络丛中均呈阳性表达 ;在缺血中心区域 ,表达 β 半乳糖苷酶的细胞数很少 ;在缺血周边区域 ,表达β 半乳糖苷酶的细胞数较多 ;而非缺血区域表达 β 半乳糖苷酶的细胞明显较缺血中心区域为多 ;其脑组织中LacZmRNA在RT PCR实验中亦呈阳性。只注射脂质体的缺血大鼠脑组织中 ,β 半乳糖苷酶和LacZmRNA的检测均为阴性。 结论　缺血性脑损伤发生后 ,脂质体介导的外源基因可在脑组织中有效表达。脂质体介导的基因转染可能是治疗缺血性脑损伤的一种有效方法。更多还原

【Abstract】 Objective To investigate whether gene expression can be achieved by liposome mediated gene transfer to rat brain after transient focal cerebral ischemia.Methods Transient focal cerebral ischemia in a rat model was produced by unilateral middle cerebral artery occlusion (MCAO) for 1 h. Reliable behavioral evaluation was employed to detect successful occlusion of the middle cerebral artery. The plasmid contained LacZ marker gene,complexed to cationic liposomes, were injected directly into the cerebral fluid of one group of animals immediately after MCAO. The other group of control animals was injected with liposomes only. Expression of β galactosidase gene product was detected by histochemistry and reverse transcription polymerase chain reaction (RT PCR). Results Positive staining of β galactosidase was clearly observed in cells of the cortical areas, deep subcortical areas, and choroid plexus at 7 days after transfection with LacZ. In the ischemic core, expression of the reporter gene was severely inhibited. In the non ischemic area, good transgene expression occurred. Compared with the non ischemic area, a moderate degree of expression was present in the peri ischemic area. LacZ mRNA in brain tissue was also detected by RT PCR. In addition, no positive staining for β galactosidase and no LacZ mRNA were detected in brain transfected with liposomes only.Conclusion Liposome mediated gene transfer into the ischemic brain provided effective expression of transgene after transient focal cerebral ischemia. Gene transfer mediated by liposome may be a promising approach for treament of cerebral ischemia.更多还原