硫化氢对创伤性脑损伤小鼠的神经保护作用研究

Neuroprotective effect of hydrogen sulfide on traumatic brain injury in mice

目的探究硫化氢(hydrogen sulfide,H_(2)S)通过改善神经炎症反应对创伤性脑损伤(traumatic brain injury,TBI)小鼠神经保护作用的影响。方法将27只雄性C57BL/6小鼠随机分为3组,假手术组(Sham组),模型组(TBI+Nacl组)和硫化氢的供体NaHS给药组(TBI+NaHS组),每组各9只。采用重锤坠落法构建中度TBI模型。干湿法测量脑含水量评估脑水肿情况,改良小鼠神经功能缺损评分(modified Neurological Severity Score,mNSS)和转棒实验评估小鼠的神经运动功能,免疫荧光染色检测小胶质细胞和星形胶质细胞的反应活性以及髓鞘丢失情况。结果TBI后1天,与Sham组相比,TBI模型组脑含水量明显增多[(85.62±2.35)%比(77.91±1.86)%,P=0.0237]。与TBI组相比,TBI+NaHS组脑含水量降低[(78.69±0.17)%比(85.62±2.35)%,P=0.0338]。TBI后第1,3和7天,与TBI组相比,TBI+NaHS组小鼠mNSS分值逐渐降低(P_(第1天)=0.0002;P_(第3天)=0.0019;P_(第7天)=0.0019)。匀速转棒实验中,与TBI组相比,TBI+NaHS组小鼠第1天和第7天转棒停留时间增加(P_(第1天)<0.0001;P_(第7天)=0.0347)。匀加速转棒实验中,与TBI组相比,TBI+NaHS组小鼠第1天,3天和7天转棒停留时间明显增加(P_(第1天)=0.0001;P_(第3天)=0.0007;P_(第7天)<0.0001)。TBI后7天,与TBI组相比,TBI+NaHS降低了小胶质细胞标志物离子钙结合衔接分子1(ionized calcium binding adapter molecule,IBA1)和星形细胞标志物胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)的表达(P_(IBA1)=0.0172;P_(GFAP)=0.0006),同时NaHS增加了髓鞘碱性蛋白(myelin basic protein,MBP)水平(P=0.002)。结论H_(2)S可通过降低胶质细胞的免疫活性,减少神经炎症的发生和提高髓鞘的完整性,进而改善TBI小鼠的神经运动功能。

Objective To explore the effect of Hydrogen sulfide(H2S)on the neuroprotective effect of Traumatic brain injury(TBI)mice by improving the neuroinflammatory response.Methods Twenty-seven male C57BL/6 mice were randomly divided into three groups:sham group,model group(TBI+Nacl group)and hydrogen sulfide donor NaHS group(TBI+NaHS group).The moderate TBI model was constructed by heavy hammer drop method.The modified Mouse Neurological Deficit Score(mNSS)was used to evaluate the neuromotor function of mice.Immunofluorescence staining was used to detect the reactivity of microglia and astrocyte and the loss of myelin sheath.Results One day after TBI,compared with the sham group,brain water content in the TBI model group was significantly increased[(85.62±2.35)%vs(77.91±1.86)%,P=0.0237].While brain water content in the TBI+NaHS group was decreased in comparision with the sham group[(78.69±0.17)%vs(85.62±2.35)%,P=0.0338].On day 1,3 and 7 after TBI,the mNSS score in the TBI+NaHS group decreased gradually in comparision with the TBI group(P_(day1)=0.0002,P_(day3)=0.0019,P_(day7)=0.0019).In the uniform rotarod test,compared with the TBI group,the retention time on the rotary of the TBI+NaHS group on day1 and 7 increased(P_(day1)<0.0001,_(Pday7)=0.0347).In the uniformly accelerated rootarod test,compared with the TBI group,the retention time on the rotary of the TBI+NaHS group on day1,3 and 7 increased significantly(P_(day1)=0.0001,P_(day3)=0.0007,P_(day7)<0.0001).7 days after TBI,compared with the TBI group,the TBI+NaHS group decreased Ionized calcium binding adapter molecule(IBA1)that is a microglia marker and Glial fibrillary acidic protein(GFAP)that is a astrocyte marker(P_(IBA1)=0.0172,P_(GFAP)=0.0006),and NaHS increased the level of myelin basic protein(MBP)(P=0.002).Conclusion H2S can improve the neuromotor function of TBI mice by reducing the immune activity of glial cells,reducing the occurrence of neuroinflammation and improving the integrity of myelin sheath.