天麻素调控miR-181b对创伤性颅脑损伤大鼠行为及脑水肿的作用机制探究

The mechanism of Gastrodin on behavior and brain edema in rats with traumatic brain injury by regulating miR-181b

目的探究天麻素(GAS)调控miR-181b对创伤性颅脑损伤(TBI)大鼠行为及脑水肿的作用机制。方法将120只SPF级SD雄性大鼠随机分为假手术组(Sham组)、TBI模型组(Model组)、低剂量GAS组(GAS-L组,50 mg/kg GAS)、高剂量GAS组(GAS-H组,100 mg/kg GAS)、高剂量GAS+miR-181b antagomir NC组(GAS-H+miR-181b antagomir NC组,100 mg/kg GAS+200 nmol miR-181b antagomir NC)和高剂量GAS+miR-181b antagomir组(GAS-H+miR-181b antagomir组,100 mg/kg GAS+200 nmol miR-181b antagomir),每组20只大鼠。采用改良神经功能缺损严重程度评分量表(mNSS)对各组大鼠神经功能进行评估。采用转棒测试、旷场实验评价大鼠行为学变化。干湿重法测定大鼠脑组织含水量。HE染色观察大鼠脑组织病理学变化。实时荧光定量PCR(RT-qPCR)法测定各组大鼠脑组织miR-181b水平。Western blot法测定大鼠脑组织中基质金属蛋白酶-9(MMP-9)、水通道蛋白-4(AQP-4)的表达水平。结果与Sham组相比,Model组大鼠mNSS评分、脑组织含水量、脑组织MMP-9、AQP4蛋白表达显著升高(P<0.05),转棒测试跌落时间、旷场实验区域中心停留时间、脑组织miR-181b水平显著降低(P<0.05),大鼠脑皮质神经元萎缩,结构紊乱,细胞轮廓不清晰,出现严重的脑损伤。与Model组相比,GAS-H组大鼠相关指标变化趋势与上述相反(P<0.05)。miR-181b antagomir减弱了GAS对TBI导致的大鼠行为学障碍和脑水肿的减轻作用。结论GAS可能通过提高miR-181b的表达来改善TBI导致的大鼠行为学障碍和脑水肿。

Objective To investigate the mechanism by which Gastrodin(GAS)regulates miR-181b in rats with traumatic brain injury(TBI)and its effects on behavior and brain edema.Methods 120 SPF-grade male SD rats were randomly divided into Sham group,Model group(TBI model),low-dose GAS group(GAS-L group,50 mg/kg GAS),high-dose GAS group(GAS-H group,100 mg/kg GAS),high-dose GAS+miR-181b antagomir NC group(GAS-H+miR-181b antagomir NC group,100 mg/kg GAS+200 nmol miR-181b antagomir NC),and high-dose GAS+miR-181b antagomir group(GAS-H+miR-181b antagomir group,100 mg/kg GAS+200 nmol miR-181b antagomir),with 20 rats in each group.Modified neurological severity scores(mNSS)were used to assess the neurological function of rats.Rotarod test and open field test were employed to evaluate behavioral changes.Brain tissue water content was measured using the wet-dry method.Histopathological changes in rat brain tissues were observed through HE staining.Real-time fluorescent quantitative PCR(RT-qPCR)was used to determine miR-181b levels in rat brain tissues.Western blot was performed to assess the expression levels of matrix metalloproteinase(MMP)-9 and aquaporin(AQP)-4 in rat brain tissues.Results Compared with the Sham group,rats in the Model group showed significantly increased mNSS scores,brain tissue water content,expression of MMP-9 and AQP4 in brain tissues(P<0.05),decreased fall time in the rotarod test,reduced central stay time in the open field test,and decreased miR-181b levels in brain tissues(P<0.05).Neurons in the rat cerebral cortex were atrophied,structurally disordered,and cell contours were unclear,indicating severe brain damage.Compared with the Model group,rats in the GAS-H group showed opposite trends in the above indicators(P<0.05).miR-181b antagomir attenuated the alleviating effects of GAS on TBI-induced behavioral disorders and brain edema.Conclusion GAS may improve TBI-induced behavioral disorders and brain edema in rats by upregulating the expression of miR-181b.