Zhang Xumei, Liu Huan, Cong Gexin, Tian Zhihong, Ren Dalin, Wilson John X, Huang Guowei
Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China.
J Nutr Sci Vitaminol (Tokyo). 2008 Oct;54(5):353-6. doi: 10.3177/jnsv.54.353.
The aim of the present study was to determine if folate alters Notch signaling and cell proliferation in neural stem cells (NSCs). NSCs were isolated from neonatal rats and grown in serum-free suspension culture. The cells were identified as NSCs by their expression of immunoreactive nestin. Individual cultures were assigned to one of three treatment groups: vehicle control, low-dose folate group (Folate-L, liquid media contained 4 mg/L folate), or high-dose folate group (Folate-H, liquid media contained 40 mg/L folate). Proliferating cells were identified by labeling with 5-bromo-2'-deoxyuridine (BrdU). Cell proliferation was quantitated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Gene expression of components of the Notch signaling system (Notch1, Hes1 and Mash1) was quantified by real-time polymerase chain reaction (PCR) assay. We observed that Nestin-positive NSCs grew as neurospheres in the serum-free suspension cultures. Folate increased the rate of cell proliferation compared to vehicle control (p<0.05). During cell proliferation, folate also increased Notch1 and Hes1 expression and decreased Mash1 expression compared to vehicle control (p<0.05). These results suggest that NSCs cultured from neonatal rats respond to folate with altered Notch signaling and increased cell proliferation.
本研究的目的是确定叶酸是否会改变神经干细胞（NSCs）中的Notch信号传导和细胞增殖。从新生大鼠中分离出神经干细胞，并在无血清悬浮培养中生长。通过免疫反应性巢蛋白的表达将这些细胞鉴定为神经干细胞。将单独的培养物分配到三个处理组之一：溶剂对照组、低剂量叶酸组（Folate-L，液体培养基含4mg/L叶酸）或高剂量叶酸组（Folate-H，液体培养基含40mg/L叶酸）。通过用5-溴-2'-脱氧尿苷（BrdU）标记来鉴定增殖细胞。通过3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴盐（MTT）测定法定量细胞增殖。通过实时聚合酶链反应（PCR）测定法定量Notch信号系统（Notch1、Hes1和Mash1）各组分的基因表达。我们观察到，在无血清悬浮培养中，巢蛋白阳性神经干细胞以神经球的形式生长。与溶剂对照组相比，叶酸增加了细胞增殖率（p<0.05）。在细胞增殖过程中，与溶剂对照组相比，叶酸还增加了Notch1和Hes1的表达，并降低了Mash1的表达（p<0.05）。这些结果表明，从新生大鼠培养的神经干细胞对叶酸的反应是Notch信号传导改变和细胞增殖增加。
