罗格列酮对大鼠蛛网膜下腔出血后脑血管痉挛的保护作用

Protective effect of PPAR-γ agonist rosiglitazone on cerebral vasospasm after subarachnoid hemorrhage in rats

目的研究过氧化物酶体增殖物活化受体γ(PPAR-γ)激动剂——罗格列酮对大鼠蛛网膜下腔出血(SAH)模型脑血管痉挛的作用及对基底动脉Toll样受体4(TLR4)介导的炎性信号通路的影响。方法取SD雄性大鼠78只,应用抽签法随机分为对照组、SAH组及罗格列酮组,每组26只。采用枕大池二次注血法建立SAH模型。在2次注血前后30 min,罗格列酮组大鼠经腹腔注射罗格列酮(3 mg/kg,0.5mg/ml,二甲亚砜为溶剂),给予SAH组大鼠等体积的二甲亚砜;对照组经枕大池注入等量等渗盐水,腹腔注射等体积二甲亚砜。于造模后第5天取基底动脉标本,HE染色观察管径和横截面积,免疫组化染色观察髓过氧化物酶(MPO)和细胞间黏附因子1(ICAM-1)的表达,Western blot检测TLR4蛋白的表达。结果对照组、SAH组、罗格列酮组大鼠的基底动脉的横截面积分别为(55508±4630)、(32139±3239)、(45969±4465)μm2,直径分别为(260±14)、(195±12)、(237±12)μm。ICAM-1阳性细胞数分别为(0.5±0.2)、(4.7±0.7)、(2.5±0.6)个,MPO阳性细胞数分别为(0.9±0.3)、(17.9±2.6)、(6.5±1.3)个。TLR4蛋白的表达量分别为0.15±0.19、1.09±0.14、0.45±0.16。SAH组、罗格列酮组的上述指标与对照组比较差异有统计学意义,SAH组与罗格列酮组比较差异亦有统计学意义,P值均<0.01。结论罗格列酮可能通过抑制TLR4信号通路途径,减轻SAH后基底动脉的炎性反应,缓解脑血管痉挛。

Objective To study the effect of peroxisome proliferator-activated receptor gamma （PPAR-γ） agonist rosiglitazone on cerebral vasospasm in a rat subarachnoid hemorrhage （SAH） model and the influence on basilar artery toll-like receptor 4 （TLR4）-mediated inflammatory signaling pathways. Methods A total of 78 male SD rats were selected and randomly divided into three groups：control group, SAH group, and rosiglitazone group （n = 26 in each group）. A SAH model was induced by injection of blood twice into cisterna magna. At 30 minutes before and after the two blood injections, the rats in the rosiglitazone group were injected rosiglitazone intraperitoneally （3 mg/kg dimethyl sulfoxide solvent） and the SAH rats were given an equal volume of dimethyl sulfoxide; the equal volume of isotonic saline was injected via cisterna magna and the equal volume of dimethyl sulfoxide in the control group was injected in traperitoneally. At day 5 after modeling, the basilar artery specimens were harvested. HE staining was used to observe the diameter and cross-sectional area. Immunohistochemical staining was used to observe the ex pression of myeloperoxidase （MPO） and intercellular adhesion molecule-1 （ ICAM-1 ）. Western blot was used to detect the expression of TLR4 protein. Results The mean cross-sectional area of the control, SAH, and rosiglitazone groups were 55 508 ±4630, 32 139 ± 3239, and 45 969 ±4465μ㎡, respectively, and their diameters were 260 ±14, 195 ± 12, and 237 ± 2 μm, respectively. The numbers of ICAM-1positive cells were 0.5 ± 0.2, 4.7 ± 0.7, and 2.5 ± 0.6, respectively. The numbers of MPO positive cells were 0.9 ±0.3, 17.9 ± 2.6, and 6.5 ± 1.3, respectively. The expression levels of TLR4 were 0. 15 ± 0.19, 1.09 ±0. 14, and 0. 45 ± 0. 16, respectively. There were significant differences in the above indicators among the SAH, rosiglitazone and control groups. There was also significant difference between the SAH group and the rosiglitazone group （P 〈 0.01 ）. Conclusion Rosiglitazone may reduce the inflammatory response of basilar artery after SAH and relieve the degree of cerebral vasospasm via inhibiting TLR4 signaling pathways.