阿替普酶对急性脑梗死大鼠海马区脑组织闭合蛋白5及铁死亡的影响

Effects of alteplase on claudin-5 and ferroptosis in the hippocampus of rats with acute cerebral infarction

目的探讨阿替普酶对急性脑梗死大鼠海马区脑组织闭合蛋白5(Claudin-5)及铁死亡的影响。方法选择雄性SD大鼠36只,按照随机数字表法分为假手术组,脑梗死组,药物组,每组12只。采用大脑中动脉凝血酶栓塞法建立急性脑梗死模型。Longa评分评价大鼠神经功能,TTC染色观察脑梗死体积,比色法检测Fe^(2+)含量,免疫组织化学及Western blot检测Claudin-5及谷胱甘肽过氧化物酶4(GPX4)及胱氨酸谷氨酸逆转运体轻链蛋白(xCT)表达。结果脑梗死组Longa评分、脑梗死体积、脑组织Fe^(2+)含量、Claudin-5表达较假手术组明显升高,GPX4及xCT表达较假手术组明显降低(P<0.01)。与脑梗死组比较,药物组Longa评分[(1.33±0.50)分vs(2.90±1.66)分,P<0.01]、脑梗死体积[(32.09±11.78)%vs(41.38±7.45)%,P<0.01]、脑组织Fe^(2+)含量[(6.02±1.93)ng/L vs(9.10±1.97)ng/L,P<0.01]、Claudin-5阳性细胞数[(78.93±16.62)个vs(91.31±7.41)个,P<0.01]、Claudin-5蛋白(0.56±0.24 vs 0.81±0.21,P<0.01)表达明显降低,GPX4[(79.80±7.74)个vs(63.60±5.15)个,P<0.01]、xCT[(81.30±19.31)个vs(71.40±21.48)个,P<0.01]阳性细胞数及GPX4蛋白(0.47±0.23 vs 0.34±0.04,P<0.01)、xCT(0.64±0.10 vs 0.46±0.11,P<0.01)蛋白表达明显升高。结论阿替普酶可减轻急性脑梗死大鼠脑组织铁死亡,减少脑梗死体积,改善神经功能,其机制可能与抑制Claudin-5蛋白有关。

Objective To explore the effects of alteplase on claudin-5 and ferroptosis in the hippocampus of rats with acute cerebral infarction.Methods A total of 36 Sprague-Dawley male rats were randomly divided into Sham,model and treatment groups,with 12 rats per group.The rat model of acute cerebral infarction was established by thrombin embolization in the middle cerebral artery.Longa score was used to observe the neurological function,and TTC staining,colorimetry,immunohistochemical assay and Western blotting were employed to observe the volume of cerebral infarct,detect the content of Fe^(2+),and measure the protein expression of claudin-5,GPX4 and xCT,respectively.Results The model group had significantly higher Longa score,larger infarct volume,and higher Fe^(2+)and claudin-5 expression,but decreased expression of GPX4 and xCT than the Sham group(P<0.01).Alteplase treatment resulted in decreased Longa score(1.33±0.50 vs 2.90±1.66,P<0.01),reduced cerebral infarct volume[(32.09±11.78)%vs(41.38±7.45)%,P<0.01],lower Fe^(2+)content(6.02±1.93 ng/L vs 9.10±1.97 ng/L,P<0.01)and number of claudin-5-positive cells(78.93±16.62 vs 91.31±7.41,P<0.01),and down-regulation of claudin-5(0.56±0.24 vs 0.81±0.21,P<0.01),and increased numbers of GPX4(79.80±7.74 vs 63.60±5.15,P<0.01)and xCT positive cells(81.30±19.31 vs 71.40±21.48,P<0.01)and up-regulation of GPX4(0.47±0.23 vs 0.34±0.04,P<0.01)and xCT(0.64±0.10 vs 0.46±0.11,P<0.01).Conclusion Alteplase can alleviate ferroptosis,reduce cerebral infarct volume,and improve neurological function in rats with acute cerebral infarction,which may be associated with its inhibition of claudin-5.