低氧诱导因子-1α与马桑内酯点燃SD大鼠难治性颞叶癫痫耐药模型耐药性的相关性研究

目的 探讨难治性颞叶癫痫中低氧诱导因子-1α (HIF-1α)在不同脑区表达水平的变化及其与耐药蛋白MDR1/Pgp表达的关系.方法 以SD大鼠作为研究对象,设置点燃组和对照组.点燃组处理方法:以马桑内酯(CL)0.4ml/kg肌注,1次/72h,在给药1～5次期间判定点燃模型是否构建成功,选择符合标准的大鼠继续给药,1次/6d,共30次；最后点燃组共存留7只大鼠.对照组5只大鼠,在同时间点给予0.4ml/kg生理盐水肌注.取大鼠脑组织标本,制备后采用实时荧光定量PCR(RQ-PCR)、免疫组织化学(IIHC)和Western blotting三种方法分别检测HIF-1 α、MDR1/Pgp在脑组织中的表达情况.结果 IHC显示,HIF-1α在点燃组主要表达于大鼠海马、颞叶皮质等部位的神经元和神经胶质细胞,在对照组仅见微弱表达.Pgp的分布及表达情况与HIF-1 α一致.RO-PCR显示,点燃组HIF-1αmRNA在海马中的表达为对照组的1.741倍,在颞叶中的表达是对照组的1.395倍.Pgp mRNA在海马及颞叶的表达分别为对照组的2.297倍和1.474倍.Western blotting显示,点燃组海马HIF-1 α蛋白表达(1.284±0.166)较对照组(0.763±0.117)明显增高(p＜0.05),且点燃组颞叶皮质中HIF-1α蛋白(1.350±0.105)亦较对照组(0.941±0.078)明显增高(P＜0.05).Pgp的表达与HIF-1α表达呈一致变化,即点燃组海马和颞叶中Pgp的表达(0.831±0.086,0.919±0.129)较对照组(0.441±0.053,0.643±0.095)明显增高(P＜0.05).另外,点燃组Pgp蛋白和mRNA在海马中的表达较颞叶高(P＜0.05).结论 HIF-1α在大鼠颞叶癫痫耐药模型的海马和颞叶皮质中的表达较正常大鼠高,且与Pgp表达的空间分布一致.HIF-1 α与PgP表达的相关性提示HIF-1 α可能与难治性颢叶癫痫的耐药性相关.

Correlational study of hypoxia-inducible factor-1 and pharmacoresistance of Sprague-Dawley rat temporal lobe epilepsy model kindled by coriaria lactone

Objective To investigate changes in the expression of hypoxia-inducible factor-1(HIF-1) in different brain regions in a pharmacoresistance model of temporal lobe epilepsy,and explore its relation to the expression of drug resistance gene/ protein multidrug-resistance-gene1(MDR1)/P-glycoprotein (Pgp). Methods A kindling model of pharmacoresistant temporal lobe epilepsy was developed by injecting Sprague-Dawley (SD) rats with coriaria lactone (CL). Normal SD rats were injected with normal sodium(NS) served as control group.The expressions of HIF-1,MDR1/Pgp in brain tissues were detected by realtime fluorescence-based quantitative polymerase chain reaction (RQ-PCR), immunohistochemistry (IHC), Western blotting, respectively.Results IHC showed that the expressions of HIF-1 in neurons and glial cells were higher in the hippocampus and temporal cortex than in other brain regions in kindled rats,and the regional distribution of HIF-1 was similar to that of Pgp.RQ-PCR and Western blotting showed that the expressions of HIF-1 in the hippocampus and temporal cortex were higher in kindled group than in control group(P<0.05),and the expressions of MDR1/Pgp in gene and protein levels were consistent with the alterations of HIF-1 in both groups.Conclusion HIF-1 expressions in hippocampus and temporal cortex in kindled rats are higher than those in control rats,and it corresponds to the regional distribution of Pgp.The correlation of HIF-1 and MDR1/Pgp expressions indicates that HIF-1 may be related to the drug resistance of refractory temporal lobe epilepsy.