生长相关蛋白-43在缺氧缺血性脑损伤新生大鼠脑内表达的变化及意义(英文)

Growth Associated Protein-43 mRNA Expression in Neonatal Rats with Hypoxic Ischemic Brain Damaged

摘要:

目的：探讨缺氧缺血性脑损伤(HIBD)后脑内神经突起外生及突触重建标志蛋白——生长相关蛋白-43(GAP-43)mRNA表达的变化及碱性成纤维细胞生长因子(bFGF)对其表达的影响。方法：取20只正常Wis-tar大鼠为正常对照组,另取54只7日龄大鼠随机分为假手术组、HIBD组和bFGF治疗组。HIBD模型参照Rice法制成。治疗组于损伤后腹腔注射bFGF、每天4U/g,直至处死;HIBD组腹腔注射等量生理盐水。采用逆转录-聚合酶链式反应(RT-PCR)技术测定3组大鼠损伤后1 d,3 d,7 d(即8,10,14日龄)以及正常大鼠2 d,5 d,7 d及14 d脑内GAP-43 mRNA的表达。结果：正常大鼠生后2天GAP-43 mRNA表达较低(0.16±0.19),以后逐渐增强,7d高峰表达,至14 d仍有较高水平表达(1.0±0.70)。HIBD后1 d双侧脑组织GAP-43 mRNA表达较假手术组明显减低。bFGF治疗3 d后,与同组治疗后1天及同日龄HIBD组比较,双侧脑组织GAP-43 mRNA表达显著增加,至7 d仍维持较高表达。结论：新生大鼠生后脑内GAP-43mRNA表达呈时间依赖性变化,与脑发育及功能成熟过程密切相关,bFGF对脑损伤后细胞增殖及功能重建有一定促进作用。

Abstract:

OBJECTIVE: To study the mRNA expression of growth associated protein-43 (GAP-43) in neonatal rats with hypoxic-ischemic brain damage (HIBD) and the influence of basic fibroblast growth factor (bFGF) on GAP-43 mRNA. METHODS: Twenty normal Wistar rats were used as the normal group, and another 54 7-day-old Wistar rats were randomly assigned into the sham operation group, HIBD group and bFGF treatment group. Immediately after HIBD models were made, 4 U/g of bFGF was injected each day in the treated group, and in the HIBD group an equal amount of NS was injected ip each day. The expression of GAP-43 was examined by RT-PCR in the three groups on day 1, day 3 and day 7 after HIBD. And the expression of GAP-43 in the normal group on the 2nd, 5th, 7th and 14th days after birth was also examined. RESULTS: The expression of GAP-43 mRNA on the 2nd day after birth was lower and it increased later to a peak on the 7th day in the normal rats. Compared with the sham operation group, GAP-43 mRNA expression on both sides of the brain in the HIBD group decreased rapidly on the 1st day after damage. In the bFGF treatment group, GAP-43 mRNA expression on the 3rd day after damage increased markedly compared with that in the HIBD group of the same age and that in the 8-day old treatment group, and it still remained at high level on day 7 after damage. CONCLUSIONS: The expression of GAP-43 mRNA in the brain of neonatal rats may change with age. It is related to the development and maturation of the brain. bFGF may have some positive effects on the restoration of brain function after HIBD.