当归对宫内缺氧新生大鼠神经干细胞增殖、分化的影响

Angelica effects on proliferation and differentiation of neural stem cells from neonatal rats with intrauterin hypoxia

背景:实验小组前期研究发现孕鼠宫内缺氧可刺激胎鼠神经干细胞的增殖,缺氧6h时增殖达高峰,在9h也表现增殖,但能力开始下降。而缺氧达12h时即表现为坏死或凋亡,但随缺氧天数的延长及时段的不同,对神经干细胞的影响又如何?目的:进一步探讨宫内缺氧对新生大鼠神经干细胞增殖、分化的影响及当归注射液的保护作用。方法:孕SD大鼠随机分为对照组、缺氧组和当归治疗组。孕14d开始将当归组与缺氧组孕鼠置于三气培养箱中,制作缺氧性脑损伤新生鼠模型,此前1h分别给于当归注射液和生理盐水尾静脉注射,对照组不缺氧,余同缺氧组。孕鼠分娩后立即取新生鼠大脑组织,经胶质纤维酸性蛋白、神经元特异性烯醇化酶免疫组织化学染色后行图像分析。结果与结论:①缺氧组新生鼠海马胶质纤维酸性蛋白免疫组织化学阳性细胞的表达较相应对照组增加;而神经元特异性烯醇化酶免疫组织化学阳性细胞的表达较对照组减小。②当归治疗组新生鼠海马胶质纤维酸性蛋白免疫组织化学阳性细胞的表达较相应缺氧组减少;而神经元特异性烯醇化酶免疫组织化学阳性细胞的表达较对照组增大。结果表明,一定程度的缺氧可刺激神经干细胞增殖,并可刺激神经干细胞向神经胶质细胞分化,以及导致神经元的减少;当归注射液可减弱由于缺氧导致的神经干细胞的增殖和向胶质细胞分化的能力,并可缓解神经元的减少,提示当归可能对缺氧大鼠神经系统有一定的保护作用。

BACKGROUND：Previous studies have found that intrauterin hypoxia could stimulate proliferation of neural stem cells（NSCs） of neonatal rats.The proliferation reached a peak during 6-hours hypoxia;proliferation also expressed in 9 hours,but the ability began to decline,but the neural stem cells showed necrosis or apoptosis when hypoxia up to 12 hours.However,what effect will have on neural stem cells with the time and day extension？ OBJECTIVE：To study the effect of intrauterin hypoxia on the proliferation and differentiation of NSCs from neonatal rats and the protective role of angelica injection on NSCs under hypoxia.METHODS：Pregnant Sprague Dawley rats were randomly divided into control group,hypoxia group and angelica group.Pregnant rats from angelica group and hypoxia group were placed in the three-gas incubator from the beginning of pregnant 14th days to make the injured brain neonatal rat model.One hour ago,the pregnant rats of the two groups received injections respectively angelica injection and normal saline through the caudal vein of rats.Hypoxia was not performed in the control group.The remaining was identical to hypoxia group.Their brain tissues of neonatal rats were immediately taken out after childbirth.The expression of glial fibrillary acidic protein（GFAP） and neurone specific enolase（NSE） of neonatal rats was studied with immunohistochemistry and the results were analyzed by image processing system.RESULTS AND CONCLUSION：①Expression of GFAP-positive cells in the hippocampus of neonatal rats in the hypoxia group was higher than control group.However,expression of NSE-positive cells was less in the hypoxia group than in the control group.②Expression of GFAP-positive cells in the hippocampus of neonatal rats was less in the angelica group than in the hypoxia group,whereas expression of NSE-positive cells was higher in the angelica group than in the control group.Results have indicated that hypoxia could stimulate the proliferation of NSCs of neonatal rats and differentiation of NSCs into glial cells.Meanwhile,the number of neuron in hippocampus CA3 area was decreased.The ability of proliferation and differentiation of NSCs into glial cells after hypoxia was attenuated by angelica injection.At the same time,angelica injection could relieve neuron decrement.These suggested that angelica injection has a certain protective effect on nervous system of neonatal rats with intrauterine hypoxia.