神经生长因子对穹窿海马伞切割后海马自体神经干细胞增殖和向神经元分化的影响

目的 探讨切割穹窿海马伞及脑室给予神经生长因子(NGF)后,对大鼠海马自体神经干细胞增殖和分化为神经元的影响.方法 12只SD大鼠,随机分成给药组和对照组,每组6只,切割右侧穹窿海马伞,两组切割后即时及第2d、4d向侧脑室分别注射NGF和人工脑脊液, 并在术后第3～7d每日腹腔注射2次BrdU.于术后28d灌注取脑、冷冻切片,行BrdU/NF-200免疫荧光双标检测.结果 海马齿状回内BrdU阳性细胞数,给药组和对照组切割侧明显多于正常侧,给药组切割侧和正常侧分别多于对照组切割侧和正常侧;海马齿状回内的BrdU/NF-200双标神经元数,给药组切割侧最多,给药组正常侧和对照组切割侧较少,而对照组正常侧则无.结论 切割穹窿海马伞后,可致大鼠海马齿状回自体神经干细胞增殖加快并向神经元分化,脑室施加 NGF可促进其增殖和分化.     

大鼠NSCs向多巴胺能神经元分化研究

目的：探讨IL-1β对神经干细胞（NSCs）分化为多巴胺能神经元作用：方法：体外培养和鉴定中脑来源NSCs，用免疫学方法检测分化细胞酪氨酸羟化酶（TH）表达.结果：血清组、IL-1β10pg／ml组、IL-1β120pg／ml组、IL-1β150pg／ml组、IL-1β200pg／ml组诱导7d后TH细胞分别平均为0,45％、0．6％、7.2％、12．5％、8．75％：结果显示IL-1β诱导NSCs明显提高TH细胞表达率，与血清组比较有显著性差异（P〈0，05），在IL-1β150pg／ml剂量范同内TH细胞表达率与剂量呈正相关。结论：IL-1β有诱导NSC向多巴胺能神经元分化的显著作用：     

Oligodendrogenesis from neural stem cells: Perspectives for remyelinating strategies

Mobilization of remyelinating cells spontaneously occurs in the adult brain. These cellular resources are specially active after demyelinating episodes in early phases of multiple sclerosis (MS). Indeed, oligodendrocyte precursor cells (OPCs) actively proliferate, migrate to and repopulate the lesioned areas. Ultimately, efficient remyelination is accomplished when new oligodendrocytes reinvest nude neuronal axons, restoring the normal properties of impulse conduction. As the disease progresses this fundamental process fails. Multiple causes seem to contribute to such transient decline, including the failure of OPCs to differentiate and enwrap the vulnerable neuronal axons. Regenerative medicine for MS has been mainly centered on the recruitment of endogenous self-repair mechanisms, or on transplantation approaches. The latter commonly involves grafting of neural precursor cells (NPCs) or neural stem cells (NSCs), with myelinogenic potential, in the injured areas. Both strategies require further understanding of the biology of oligodendrocyte differentiation and remyelination. Indeed, the success of transplantation largely depends on the pre-commitment of transplanted NPCs or NSCs into oligodendroglial cell type, while the endogenous differentiation of OPCs needs to be boosted in chronic stages of the disease. Thus, much effort has been focused on finding molecular targets that drive oligodendrocytes commitment and development. The present review explores several aspects of remyelination that must be considered in the design of a cell-based therapy for MS, and explores more deeply the challenge of fostering oligodendrogenesis. In this regard, we discuss herein a tool developed in our research group useful to search novel oligodendrogenic factors and to study oligodendrocyte differentiation in a time- and cost-saving manner.     

Irradiated microvascular endothelial cells may induce bystander effects in neural stem cells leading to neurogenesis inhibition

Radiation-induced neurocognitive dysfunction (RIND) has attracted a lot of attention lately due to the significant improvement of the survival of cancer patients after receiving cranial radiotherapy. The detailed mechanisms are not completely understood, but extensive evidence supports an involvement of the inhibition of hippocampal neurogenesis, which may result from radiation-induced depletion of neural stem cells (NSCs) as well as the damage to neurogenic niches. As an important component of neurogenic niches, vascular cells interact with NSCs through different signaling mechanisms, which is similar to the characteristics of radiation-induced bystander effect (RIBE). But whether RIBE is involved in neurogenesis inhibition contributed by the damaged vascular cells is unknown. Thus, the purpose of the present study was to investigate the occurrence of RIBEs in non-irradiated bystander NSCs induced by irradiated bEnd.3 vascular endothelial cells in a co-culture system. The results show that compared with the NSCs cultured alone, the properties of NSCs were significantly affected after co-culture with bEnd.3 cells, and further change was induced without obvious oxidative stress and apoptosis when bEnd.3 cells were irradiated, manifesting as a reduction in the proliferation, neurosphere-forming capability and differentiation potential of NSCs. All these results suggest that the damaged vascular endothelial cells may contribute to neurogenesis inhibition via inducing RIBEs in NSCs, thus leading to RIND.     

骨髓间充质干细胞体外诱导分化为神经样细胞的机制

目的探索骨髓间充质干细胞 (MSCs)在体外诱导分化为神经样细胞的机制。方法分离培养大鼠MSCs ,用二甲基亚砜 (DSMO)和丁羟茴醚 (BHA)诱导分化 ,检测诱导分化前、预诱导 2 4h、诱导分化后 6h、2 4h和 48h神经细胞和神经干细胞的特异性标记蛋白的表达。结果诱导分化后 ,大部分MSCs变成双极、多极和锥形 ,并相互交织成网络结构 ,巢蛋白 (Nestin)在诱导分化前不表达 ,在诱导分化后 6h达到最高 ,2 4h和 48h逐渐降低。神经元特异性核蛋白 (NeuN )在诱导分化前不表达 ,在诱导分化后 6h出现表达 ,2 4h和 48h表达增强。结论MSCs经体外诱导先分化为神经干细胞 ,然后分化为神经元样细胞。     

己烯雌酚对体外培养胎鼠中脑NSCs增殖分化的影响

为观察己烯雌酚对体外培养的胎鼠中脑神经干细胞(NSCs)增殖分化的影响,将孕14d的SD大鼠胎鼠中脑取出,制成单细胞悬液行悬浮培养,5d后行NSCs鉴定、传代及诱导分化实验。实验分空白对照组和己烯雌酚组(浓度分别为10-9、10-8、10-7mol/L)。在倒置显微镜下观察各组细胞的存活及生长状况,免疫荧光化学方法行NSCs鉴定及诱导分化后神经元特异烯醇化酶(NSE)及神经胶质酸性蛋白(GFAP)表达情况的检测。结果显示:己烯雌酚浓度在10-8mol/L时中脑NSCs增殖、分化明显,并能提高神经元的分化率。由此说明己烯雌酚对中脑NSCs的增殖分化具有促进作用,并能促进其向神经元分化。     

大鼠骨髓源性神经干细胞移植治疗颞叶癫痫实验研究

目的 探讨骨髓源性神经干细胞移植至KA大鼠海马后与宿主细胞的整合及其对损伤宿主的修复作用,从而为干细胞移植治疗颞叶癫痫提供理论依据.方法 首先分离大鼠骨髓基质细胞,并在特定的条件下培养使其诱导分化为神经干细胞,且使用Feridex对干细胞进行标记.然后建立大鼠颞叶癫痫模型,将Feridex标记的神经干细胞自体移植至KA大鼠的海马内,观察移植后1周、2周、4周、8周和16周大鼠海马的脑电图、病理学和MRI改变情况.结果 与KA未移植组相比,移植组大鼠海马脑电图的波幅明显降低,最高降低达40%以上;KA移植组海马CA3区锥体细胞数与未移植组相比有极显著性差异（P＜0.01）;KA移植组海马损伤侧的Timm染色与未移植组相比也有极显著性差异（P＜0.01）;MRI检查发现在神经干细胞移植后1周和2周时低信号改变区比较局限,但移植4周、8周和16周后低信号改变明显增大,且随着时间的推移低信号改变区逐渐增大.结论 骨髓源性神经干细胞移植至KA大鼠后能与宿主细胞进行整合,且对宿主海马具有显著的修复作用,但其具体的作用机制尚待进一步研究.     

神经干细胞移植促进脑出血大鼠神经功能恢复的实验研究

目的探讨脑内定向移植神经干细胞(NSCs)治疗脑出血的可行性和机制。方法采用在成年大鼠中立体定向纹状体内注入新鲜自体血液制作实验性脑出血模型,术后1d采用立体定向将在体外扩增、纯化并经BrdU标记的神经干细胞移植入脑出血部位,通过神经功能缺损评分来观察移植后大鼠神经行为学改善情况,并通过双标GFAP、NeuN、BrdU免疫组化来检测移植入脑的NSCs。结果移植的NSCs迁移至血肿周围区,并分化为神经元(≈10%BrdU阳性细胞)和星形胶质细胞(≈75%);与对照组比较,NSCs移植组在移植后1周有更好的神经功能缺损评分,而且此疗效可维持长达8周。结论移植的NSCs可在脑出血的大鼠脑中存活、迁移,并促进功能恢复。立体定向移植神经干细胞可改善实验性脑出血大鼠的神经功能。     

针刺作用于脑卒中后NSCs增殖的多信号通路研究进展

针刺不仅在整体水平上促进神经细胞的代偿性修复,减轻神经功能缺损程度,还可以作用到各个神经通路进行调节.针刺可以抑制或者上调很多蛋白的表达,进而影响各个信号通路.有些针刺效应更能作用于各个信号通路相链接的靶点蛋白上,从整体上抑制负性的信号通路,促进正性的信号通路.但目前针刺对各信号通路的调控主次作用不明确,各信号通路发挥的主次作用也不明确,仍需进一步研究,以寻求更明确的作用机制和作用靶点,明确主次关系.     

核转录因子NF-κB与缺血性脑血管病的研究

核转录因子NF-κB是一种具有多项转录作用的调节因子,其信号转导过程参与了脑缺血损伤时中枢神经系统神经干细胞增殖、迁移、分化以及炎性反应、细胞保护与凋亡等生物进程.因此,对NF-κB作用机制的深入研究,对于缺血性脑血管疾病的临床防治具有重要意义.