叶酸对体外缺氧神经干细胞保护作用的研究

THE PROTECTIVE ROLE OF FOLATE ON NEURAL STEM CELLS UNDER HYPOXIA IN VITRO

目的研究叶酸(folate,Fol)对体外培养缺氧神经干细胞(neural stem cell,NSCs)增殖、凋亡和抗氧化能力的影响。方法采用无血清体外细胞培养方法,培养新生大鼠NSCs。将其分为4组,即正常对照(normal control,NC)、缺氧模型(hypoxia,Hyp)、缺氧叶酸缺乏(Hpy+Fol-D)和缺氧叶酸添加(Hpy+Fol)组。除NC组以外,其余三组放入缺氧环境中6h,造成缺氧损伤。采用MTT法检测缺氧后细胞增殖能力的变化;收集增殖6d的细胞,测定缺氧后NSCs超氧化物歧化酶(superoxide dismutase,SOD)和谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)的活性;采用Western blot方法检测caspase-3的活性表达水平。结果与NC组比较,缺氧干预后NSCs增殖明显下降,SOD和GSH-PX活性降低,caspase-3的活性表达增加;Hpy组细胞增殖能力、SOD和GSH-PX活性均显著高于Hpy+Fol-D组,低于Hpy+Fol组(P<0.05),caspase-3的活性表达显著高于Hpy+Fol组,低于Hpy+Fol-D组(P<0.05)。结论缺氧可造成NSCs损伤,叶酸缺乏能使缺氧后NSCs的损伤加重,补充叶酸能促进缺氧后NSCs增殖,提高其抗氧化能力,抑制NSCs凋亡,对体外大鼠NSCs的缺氧损伤恢复有促进作用。

Objective To study the effects of folate （Fol） on proliferation, apoptosis and the antioxidative capacity of the NSCs under hypoxia in vitro. Method The NSCs taken from infant rats brain were cultured by serum-free medium in vitro and divided into four group which were normal control group （NC）, hypoxia group （Hyp）, Hpy＋Fol-D （folate deficient） group and Hpy＋Fol group. Except NC group, the other groups were cultured in hypoxia condition for 6 h. The proliferation of NSCs after hypoxia damage was detected by MTT test. The NSCs were collected after being cultured 6 d and then the activity of SOD and GSH-Px was examined. The expression of activated caspase-3 was detected by Western blot. Results Compared with NC group, the proliferation of NSCs and the activity of SOD＇and GSH-Px decreased significantly after hypoxia, while the expression of activated caspase-3 increased0 The proliferation of NSCs and the activity of SOD and GSH-Px in Hyp group were significantly higher than Hyp＋Fol-D group but much lower than HpyWFol group （P〈0.05）, while the expression of activated caspase-3 was much higher than HpyWFol group but much lower than Hpyq-Fol-D group （P〈0.05）. Conclusion Folate deficiency can aggravate the damage of NSCs injured after hypoxia, and folate supplement can promote the proliferation of NSCs, improve the antioxidative capacity and inhibit the apoptosis of NSCs induced by hypoxia, so that folate can promote the recovery of hypoxia damaged NSCs in vitro.