液态氟碳纳米粒对大鼠蛛网膜下腔出血后早期脑损伤的保护作用

Perfluorooctyl-bromide nanoparticles protect early brain injury in rats after subarachnoid hemorrhage

目的探讨液态氟碳全氟辛基溴(perfluorooctyl-bromide,PFOB)纳米粒对大鼠蛛网膜下腔出血(subarachnoid hemorrhage,SAH)后早期脑损伤(early brain injury,EBI)的保护作用。方法采用雄性健康SD大鼠共90只,分为假手术组(SHAM)30只、蛛血组(SAH)30只及PFOB干预组(SAH+PFOB)30只。使用经视交叉前池注血法制作SAH模型。术后24 h检测脑含水量,透射电镜观察大鼠海马形态学改变,TUNEL染色检测大鼠海马CA1区神经元凋亡,完成免疫组化染色。Western blot检测术后12、24、48、72 h Caspase-3蛋白表达情况。结果 SAH+PFOB组同SAH组比较,脑含水量明显降低(P<0.01);电镜下见海马区神经元凋亡减少、胶质细胞肿胀减轻、血管周围水肿减轻。免疫组化染色结果显示,Caspase-3表达明显降低。TUNEL染色结果见海马CA1区细胞凋亡率明显降低(P<0.01)。Western blot检测结果显示,Caspase-3在SAH后12、24、48、72 h均可见明显降低(P<0.01)。结论溶解高浓度氧的液态氟碳纳米粒能够减轻蛛网膜下腔出血后神经元的凋亡,改善脑水肿、改善脑缺氧,对早期脑损伤起到保护作用。

Objective To determine the protective effects of perfluorooctyl-bromide（ PFOB）nanoparticles on early brain injury（ EBI） in rats following subarachnoid hemorrhage（ SAH）. Methods Ninety male healthy SD rats were randomly divided into 3 groups,that is,sham-operation group（ n = 30）,SAH model group（ n = 30） and SAH ＋ PFOB group（ n = 30）. Rat SAH model was produced by injecting blood into the prechiasmatic cistern. PFOB nanoparticles as emulsifier with high concentrations of dissolved oxygen was injected to the rats of the treatment group via tail vein in 3 h after model establishment. Brain water content was measured in 24 h after surgery. Morphological changes in the rat hippocampal CA1 region were examined by transmission electron microscopy. The neuronal apoptosis in the region was determined by TUNEL assay,and immunohistochemical staining was performed for the expression of Caspase-3. Protein expression levels of Caspase-3 were detected by Western blot assay in 12,24,48 and 72 h postoperatively.Results Compared to the SAH group,the SAH ＋ PFOB group had significantly lower brain water content（ P 〈 0. 01）. Transmission electron microscopy revealed the reduction of neuronal apoptosis,alleviation of glial cell swelling,and mitigation of perivascular edema in the hippocampal region. Immunohistochemical data showed that the expression of apoptosis-related factor Caspase-3 was significantly reduced. TUNEL staining showed that neuronal apoptosis was significantly reduced in the hippocampal CA1 region（ P 〈 0. 01）. Western blot assay indicated that the expression of Caspase-3 was significantly reduced at 12,24,48 and 72 h after SAH（ P 〈 0. 01）. Conclusion PFOB nanoparticles with high oxygen content could counteract ischemia and hypoxia,block neuronal apoptotic pathways,reduce neuronal apoptosis,and achieve neuroprotective effects in EBI following SAH.