葡萄籽原花青素通过细胞外信号调节激酶1/2途径对放射性脑损伤大鼠海马区生长相关蛋白-43活性的影响

摘要

Objective To observe the effect of grape seed proanthocyanidin extract (GSPE) on growth associated protein-43 (GAP-43) through extracellular signal regulated kinase 1/2 (ERK1/2) pathway in rats with brain radiation injury. Methods 72 3-month male Sprague-Dawley rats were divided into control group (n=18), model group (n=18), high dose GSPE group (n=18) and low dose GSPE group (n=18). The brain radiation injury models were established by linear accelerator irradiation with 22 Gy. The learning ability was assessed with shuttle box. The morphological changes of neurons in hippocampus were observed with HE staining;the expression of GAP-43 was de-tected by RT-PCR; and the expression of phosphorylated ERK1/2 was detected by Western blotting. Results Compared with the model group, the active avoidance reaction rate in the shuttle box test increased and the passive avoidance latency shortened in GSPE groups (P<0.001); the nerve cell morphological injury reduced and the expression of GAP-43 mRNA and phosphorylated ERK1/2 increased in the GSPE groups (P<0.001), especially in the high dose GSPE group (P<0.001). The GAP-43 mRNA level positively correlated with phosphory-lated ERK1/2 level in the model group (r=0.764, P<0.001), the low dose GSPE group (r=0.814, P<0.001) and the high dose GSPE group (r=0.822, P<0.001). Conclusion GSPE could promote the expression of GAP-43 through ERK1/2 pathway in rats, and prevent the brain from radiation injury.%目的：观察葡萄籽原花青素(GSPE)对放射性脑损伤大鼠的防治作用，并分析可能的保护机制。方法72只3月龄雄性Sprague-Dawley大鼠随机分为对照组(n=18)、模型组(n=18)、低剂量GSPE组(n=18)和高剂量GSPE组(n=18)。用直线加速器进行脑部照射22 Gy制作放射性脑损伤模型。采用穿梭箱实验检测大鼠学习能力；HE染色观察海马区神经细胞组织形态变化；RT-PCR法检测生长相关蛋白-43(GAP-43) mRNA表达，Western blotting检测磷酸化的细胞外信号调节激酶1/2(ERK1/2)表达。结果与模型组比较，各GSPE组动物穿梭箱主动回避反应率显著升高(P<0.001)，被动回避潜伏期显著缩短(P<0.001)；海马区神经细胞结构损伤减轻；GAP-43 mRNA和磷酸化ERK1/2表达水平增高(P<0.001)。且高剂量GSPE组显著优于低剂量GSPE组(P<0.001)。模型组中GAP-43 mRNA表达水平与磷酸化ERK1/2水平呈正相关(r=0.764, P<0.001)；低剂量GSPE组和高剂量GSPE组中GAP-43 mRNA表达水平与磷酸化ERK1/2水平呈正相关(r=0.814,0.822, P<0.001)。结论 GSPE通过ERK1/2途径提高大鼠海马区GAP-43表达，发挥防治放射性脑损伤作用。