胰岛素样生长因子1在脑梗死大鼠神经干细胞增殖、迁移和分化中的作用(英文)

Role of insulin-like growth factor-1 in proliferation,migration and differentiation of neural stem cells in cerebral infarction rats

背景:胰岛素样生长因子1是一种多肽类激素,已证明其对前体细胞增殖有促进作用。目的:探讨静脉注射胰岛素样生长因子1对大鼠脑缺血后神经干细胞增殖、迁移和分化的影响。方法:成年雄性SD大鼠80只,随机分为对照组和实验组,40只/组。两组大鼠均采用改良线栓法制备局灶性脑缺血模型,实验组大鼠通过尾静脉注射胰岛素样生长因子1,按100μg/kg计算,连续注射6d;对照组给予等剂量的生理盐水。分别于干预后7,14,21,28d断头去脑,各组分别在处死前1d腹腔注射BrdU。采用免疫组织化学及其双重染色法检测BrdU阳性细胞、PSA-NCAM阳性细胞、BrdU+PSA-NCAM双阳性细胞、BrdU+MAP2双阳性细胞的表达。结果与结论:BrdU阳性细胞、PSA-NCAM阳性细胞数均在缺血后7d最多;BrdU+PSA-NCAM双标阳性细胞在缺血后双侧室管膜下区和海马齿状回区均可以检测到,于7d计数最多,之后逐渐减少;BrdU+MAP2双阳性细胞却从14d开始逐渐增多,随BrdU+PSA-NCAM双阳性表达的逐渐降低,BrdU+MAP2双阳性表达逐渐增高,呈现此消彼涨的变化。提示静脉途经给予胰岛素样生长因子1能诱导大鼠缺血性脑损伤后神经干细胞的增殖、分化和迁移。

BACKGROUND：Insulin-like growth factor-1 （IGF-1） is a peptide hormone,it has been proved a promotion role on the proliferation of precursor cells.OBJECTIVE：To explore the intravenous injection of IGF-1 on the proliferation,migration and differentiation of neural stem cells in rats after cerebral ischemia.METHODS：Eight adult male SD rats were randomly divided into control group and experimental group,with 40 rats in each group.The rats in two groups were used to prepare models of focal cerebral ischemia using modified suture method,the rats in the experimental group were treated with tail vein injection of IGF-1,according to 100 μg/kg computation,the injection was given for 6 continuous days;in the control group,rats were given equal volume of saline.The rats were decapitated at 7,14,21,28 days following intervention,respectively,and rats in each group were given intraperitoneal injection of the BrdU at 1 day before death.Immunohistochemistry and double staining were applied to detect the expressions of BrdU-positive cells,PSA-NCAM-positive cells,BrdU ＋ PSA-NCAM double-positive cells,and BrdU ＋ MAP2 double-positive cells.RESULTS AND CONCLUSION：The number of BrdU-positive cells and PSA-NCAM positive cells reached the peak at 7 days after ischemia;BrdU ＋ PSA-NCAM double-labeled-positive cells could be detected in ischemic bilateral subependymal zone and dentate gyrus,the number was the most at 7 days,then followed by a gradual decrease;the BrdU ＋ MAP2 double-positive cells began to increase from 14 days,and then gradually increased along with the decrease of BrdU ＋ PSA-NCAM double-positive expression,showing a reverse trend.Intravenous injection of IGF-1 can induce the proliferation,differentiation and migration of neural stem cells in rats following ischemic brain injury.