大鼠脑实质注射血清所致病理改变及其相关机制的研究

Study on Pathological Changes and Related Mechanism Induced by Brain Injection of Serum in Rats

目的探讨大鼠脑实质注射血清所致病理改变及其相关机制。方法在大鼠脑实质注射胎牛血(FBS)建立大鼠脑实质血清注射模型,对照组注射等体积生理盐水。术后48 h对比两组大鼠生存率、行为学改变。取材测量脑组织含水量变化,观察脑实质组织学及超微结构的改变,逆转录PCR检测脑组织水通道蛋白-4(AQP-4) mRNA的表达,蛋白免疫印迹检测AQP-4蛋白的表达。含血清/无血清培养大鼠星形胶质细胞,逆转录PCR检测细胞AQP-4 mRNA的表达,蛋白免疫印迹检测AQP-4蛋白的表达。结果电子显微镜下显示实验组注射部位周围脑组织水肿;实验组注射侧脑组织表达AQP-4蛋白与mRNA均较对照组明显减少(P<0.01),实验组注射部位对侧脑组织表达AQP-4蛋白与mRNA与对照组未见明显差异(P>0.05);相对于无血清培养组,含血清培养组大鼠星形胶质细胞表达AQP-4蛋白及mRNA均明显下降(P<0.05)。结论体外与体内实验共同表明,血清导致脑组织、尤其是星形胶质细胞AQP-4表达下降可能是脑出血(ICH)后继发性脑水肿的重要分子机制,为未来治疗脑出血后脑水肿治疗提供新的治疗靶点。

Objective To investigate the pathological changes and related mechanism induced by brain injection of serum in rats.Methods Injection of fetal bovine serum(FBS) into rat brain.The control group injected the same volume normal saline,after 48 h contrast two groups survival rate,behavioral change,the measurement of brain tissue water content changes,RT-PCR detection of aquaporin-4(AQP-4) mRNA expression;The expression of AQP-4 protein was detected by Western blot.The expression of AQP-4 mRNA was detected in serum/serum-free culture of rat astrocytes,RT-PCR,and the expression of AQP-4 protein was detected by Western blot.Results The survival rate and behavioral score of the experimental group were significantly improved compared with the control group.The edema of brain tissue around the injection site of the experimental group was shown under electron microscope,the expression of AQP-4 protein and mRNA in the experimental group was significantly higher than that in the control group(P<0.01),the expression of AQP-4 protein and mRNA in the injection site of the experimental group were not significantly different from that of the control group(P<0.05);Compared with serum-free culture group,the expression of AQP-4 protein in astrocytes of rat with serum and mRNA were significantly decreased(P<0.05).Conclusion In vitro and in vivo,it is shown that the decrease of AQP-4 expression in brain tissue,especially astrocytes may be an important molecular mechanism of secondary cerebral edema after intracerebral hemorrhage(ICH),and provide a new therapeutic target for the treatment of cerebral edema after ICH in the future.