EGCG治疗大鼠脊髓损伤后脊髓水肿的机制研究

目的 探讨表没食子儿茶素没食子酸酯(EGCG)治疗脊髓损伤后继发脊髓水肿的可能机制.方法 取80只成年SD大鼠,随机分为假手术组,损伤对照组,EGCG组和甲基强的松龙(MPSS)组,每组20只.采用钳夹法制备脊髓损伤模型,造模24 h后,通过脊髓干湿重检测评估脊髓水肿情况,测定各组脊髓组织中丙二醛(MDA)与超氧化物歧化酶(SOD)含量,HE染色观察脊髓损伤后局部出血及坏死情况,免疫组化及Western blot检测损伤节段AQP4,GFAP,Kir4.1蛋白表达.结果 HE染色显示损伤对照组脊髓局部大量出血,神经细胞肿胀、坏死;EGCG组和MPSS组情况相近,出血范围较小,神经细胞轻度水肿.与假手术组比较,损伤对照组脊髓组织含水量增多,MDA水平增加,SOD活性下降,损伤节段AQP4,GFAP,Kir4.1蛋白表达增高,差异有统计学意义(P<0.05).与损伤对照组比较,EGCG组和MPSS组脊髓含水量降低、MDA水平下降、SOD活性增高、AQP4、GFAP、Kir4.1蛋白表达降低,差异均有统计学意义(P<0.05),而EGCG组和MPSS组间上述指标没有明显差异(P>0.05).结论 EGCG能够减轻脊髓损伤后的脊髓水肿程度,可能是通过调节损伤节段AQP4和Kir4.1蛋白表达实现的,在这一过程中GFAP特异性表达的星形胶质细胞可能也参与其中.EGCG是安全有效的一种潜在治疗脊髓损伤的药物.

Anti-edema effect of epigallocatechin gallate on spinal cord injury in rats

Objective To explore the possible mechanism of epigallocatechin gallate (EGCG) in the treatment of edema after spinal cord injury. Methods Eighty adult Sprague-Dawley (SD) rats were randomly and evenly allocated into sham group, spinal cord injury (SCI) group, EGCG group and methylprednisolonen (MPSS) group. The spinal cord edema was estimated by dry and wet weight of the spinal cord, and the content of malondialdehyde (MDA) and superoxide dismutase (SOD) in the spinal cord tissues was determined. We used HE staining to observe the local injury after spinal cord injury. Immunohistochemistry staining and WB method to detect observe AQP4, GFAP and Kir4.1 expression in the injury segment. Results HE staining showed massive hemorrhage, swelling and necrosis of nerve cells in the SCI group. EGCG group and MPSS group showed similar conditions with smaller bleeding points and mild edema of nerve cells. Compared with the sham group, the spinal cord water content increased, MDA level increased, SOD activity decreased, and AQP4, GFAP, Kir4.1 protein expression of the injured segment increased in the SCI group (P<0.05). Compared with the SCI group, the spinal cord water content decreased, MDA level decreased, SOD activity increased, and AQP4, GFAP, Kir4.1 protein expression decreased in EGCG and MPSS group (P<0.05). There was no significant difference between EGCG group and MPSS group (P>0.05).Conclusion EGCG could reduce the degree of edema after spinal cord injury by down regulation AQP4 and Kir4.1 expression. EGCG could be a potential treatment option for spinal cord injury.