去分化肌肉干细胞神经分化潜能的探讨

目的探讨去分化肌肉干细胞经条件培养诱导,具有神经干细胞性质并分化为终末神经细胞的潜能。方法依次用神经干细胞增殖及神经细胞分化条件培养基,对去分化肌肉干细胞进行体外诱导,促使其向神经干细胞转变以及向终末神经细胞分化,并通过形态学、免疫细胞化学、RT-PCR等实验手段研究其性质并加以鉴定。结果 (1)去分化肌肉干细胞在神经干细胞增殖条件培养基诱导下,可形成神经球,EdU标记阳性,抗Nestin、Neurofilament-m(NFm)、GFAP、CNPase阳性;Myogenin表达水平下调,而Nestin、Sca-1表达上调;(2)经神经细胞分化条件培养基诱导,神经球细胞可分化为形态学上典型的、抗NFm阳性神经元,以及抗GFAP、CNPase阳性神经胶质细胞。结论去分化肌肉干细胞具有神经系的多分化潜能。     

双嘧达莫对体外培养神经干细胞增殖的影响

目的研究双嘧达莫(dipyridamole)对体外培养神经干细胞的促增殖作用.方法取新生小鼠大脑进行神经干细胞原代培养,通过神经球生成的观察、特异性蛋白质免疫细胞化学染色和BrdU标记鉴定并判断其增殖能力;双嘧达莫按0.1,0.5,2.5 μmol·L-13个浓度加入神经干细胞培养基中,同时设立溶媒对照组和阳性对照组,通过观察神经球形态、神经球生成数目及MTT法定量比较,分析不同浓度双嘧达莫对神经干细胞分裂增殖的影响.结果在培养物中有大量神经球生成,神经干细胞的特异性蛋白质免疫细胞化学染色呈阳性,BrdU标记亦呈阳性反应,表明所培养的细胞为神经干细胞,具有增殖能力.双嘧达莫中、高浓度组神经球数目、MTT比色结果明显高于溶媒对照组.结论双嘧达莫具有促进神经干细胞增殖的作用.     

骨骼肌提取液促进体外培养神经干细胞增殖作用研究

目的寻找促神经干细胞分裂增殖物质,为神经系统发育研究和神经系统疾病的治疗研究提供新的依据。方法用硫酸铵盐析及超滤离心法分离骨骼肌蛋白质,体外培养新生小鼠神经干细胞,通过神经球生成的观察、特异性蛋白质免疫细胞化学染色和MTT比色检测法鉴定神经干细胞并判断其增殖能力。结果在培养物中有大量神经球生成,且与对照组差异有显著性(P<0.01),神经干细胞的特异性蛋白质(Nestin)免疫细胞化学染色呈阳性。结论骨骼肌提取液可促进体外培养神经干细胞增殖分裂,且呈一定量效关系,其有效成分为分子量≤100 ku的蛋白质分子。     

腺苷促进体外培养神经干细胞增殖作用研究

目的研究腺苷促进体外培养神经干细胞（NSCs）增殖作用。方法取新生小鼠大脑进行神经干细胞原代培养,观察神经球生成情况,特异性蛋白质免疫细胞化学染色和BrdU标记鉴定并判断其增殖能力;将腺苷按0.4,2.0,10.0 μmol&#8226;L 13个浓度加入神经干细胞培养基,同时设立溶媒对照组和阳性对照组,通过观察神经球形态、神经球生成数目及 MTT法定量比较,分析不同浓度腺苷对神经干细胞分裂增殖的影响。结果培养物中有大量神经球生成,神经干细胞特异性蛋白质免疫细胞化学染色呈阳性,BrdU标记亦呈阳性反应,所培养的细胞为神经干细胞,具有增殖能力;腺苷中、高浓度组神经球数目、MTT比色结果明显高于溶媒对照组。结论腺苷具有促进NSCs增殖作用。     

双嘧达莫可能通过Trk受体促进神经干细胞增殖

目的:探讨双嘧达莫促进体外培养神经干细胞增殖的机制。方法:取新生小鼠大脑进行神经干细胞原代培养,以2.5μmol·L~(-1)双嘧达莫组作为阳性对照组,分别加入腺苷受体拮抗剂CGS15943和Trk受体拮抗剂K252a,通过观察神经球形态、神经球生成数目、MTT法定量,初步探讨双嘧达莫促神经干细胞增殖的机制。结果:K252a 双嘧达莫组神经球数量和细胞活性均明显低于双嘧达莫组(P<0,01),而CGS15943 双嘧达莫组与双嘧达莫组相比差异无统计学意义。结论:双嘧达莫的促神经干细胞增殖作用可能是通过Trk受体介导的。     

新生小鼠神经干细胞体外培养、分化及鉴定

目的 简化神经干细胞原代培养的取材及步骤,明确体外定向诱导分化条件,为进一步神经干细胞移植相关实验提供基础条件。方法 新生24 h昆明种小鼠无菌条件下冰上取大脑组织,经机械分离加胰酶消化吹打后,加入含有碱性成纤维细胞生长因子、表皮细胞生长因子和B27的DMEM/F12培养基中培养;加入不同浓度胎牛血清诱导其分化,应用免疫荧光技术行巢蛋白、胶质纤维酸性蛋白、微管相关蛋白2染色,对培养细胞鉴定。结果 新生小鼠提取神经干细胞可形成神经球,并稳定增殖传代,经诱导可定向分化为神经元及星形胶质细胞。结论 新生小鼠较胎鼠取材简单,可培养高质量神经干细胞,血清浓度同向星型胶质细胞方向的分化概率呈正相关。     

β-淀粉样蛋白对神经干细胞致凋亡作用研究

目的观察β-淀粉样蛋白(Aβ)能否诱导体外培养的大鼠神经干细胞凋亡。方法取孕13d的胎鼠大脑,体外进行培养、传代、鉴定后,加入Aβ,利用细胞计数观察细胞增生,利用琼脂糖凝胶电泳及流式细胞仪观察凋亡情况。结果当Aβ浓度>25μmol/L时,能明显抑制神经干细胞的增生,同时引起神经干细胞的明显凋亡。结论Aβ抑制神经干细胞的增生并可致神经干细胞凋亡,可能与阿尔茨海默病的发病有关。     

胶质瘤细胞诱导神经干细胞迁移作用的实验研究

目的观察胶质瘤细胞在体外培养条件下对神经干细胞是否有诱导迁移的作用。方法①从新生1～2dSD大鼠脑皮层分离培养神经干细胞,进行神经干细胞及其增殖能力鉴定。②胶质瘤细胞与神经干细胞限定区域联合培养,观察神经干细胞的生长及其形态学变化。结果①所获得神经细胞球Nestin染色阳性,传代神经细胞球抗BrdU染色阳性。②可观察到神经干细胞球周围长出细胞突起,在靠近胶质瘤细胞的一侧,细胞突起的密度及长度均大于其他方向上的突起并且可见部分干细胞向胶质瘤细胞方向的移动。结论胶质瘤细胞在体外对神经干细胞有诱导迁移作用。     

GM-1对新生大鼠神经干细胞增殖和分化的影响

目的:观察不同剂量神经节苷脂(GM—1)对神经干细胞增殖和分化的影响。方法:从新生大鼠海马组织分离出神经干细胞,分别培养于基础培养液(阴性对照组) ,加入三种不同剂量GM—1(实验组)及含有b FGF(阳性对照组)的神经干细胞培养液。采用神经干细胞球直接计数法测定细胞的增殖能力,并应用免疫细胞化学技术对神经干细胞分化情况进行鉴定。结果:3个实验组神经干细胞的增殖能力较阳性对照组无明显差异,较阴性对照组差异显著,贴壁培养细胞分化发现3个实验组分化能力明显低于阳性对照组。结论:GM—1对新生鼠神经干细胞的增殖起促进作用,对神经干细胞无明显的诱导分化作用。     

神经干细胞与脑源性神经生长因子

神经干细胞对于损伤后的脑组织的修复、再生起着关键作用,脑源性神经生长因子对于干细胞的增殖分化起着重要作用。现有关于神经干细胞研究多为体外细胞研究,对于脑源性神经生长因子等因子对于内源性神经干细胞影响的研究较少。中医药诱导脑源性神经生长因子等其他因子增殖,进而影响神经干细胞增殖分化,可能成为一个新的研究切入点。     

大鼠神经干细胞的分离培养和分化鉴定

目的建立神经干细胞分离、培养和分化鉴定技术。观察神经干细胞生长、增殖特点。方法利用无血清培养,从胚胎大鼠海马、纹状体等区分离神经干细胞,进行体外扩增培养、传代观察。采用荧光免疫细胞化学检测技术,观察鉴定神经干细胞及其分化结果。结果从胚胎大鼠海马、纹状体等区分离的细胞具有增殖能力,可进行传代培养,获得的细胞克隆中有巢蛋白(nestin)表达阳性细胞,显微镜下观察见典型的干细胞特征。分化为3种神经细胞类型:神经元、胶质细胞、少突胶质细胞。结论用上述方法分离培养的神经干细胞具有自我更新和增殖能力,通过鉴定确为神经干细胞,并经过分化鉴定确认。     

Study of lead-induced neurotoxicity in neural cells differentiated from adipose tissue-derived stem cells

Abstract

In recent years, the use of stem cells as a new tool to create an in vitro model for toxicological studies has been considered. Adipose tissue-derived stem cells (ADSCs) are mesenchymal stem cells which have been extracted from adipose tissue by a less invasive method and rapidly propagated in culture medium compared with other sources. These cells have the capacity to differentiate into different cell lineage in vitro including neural cells. The aim of this study was to investigate the effect of lead exposure at various stages of differentiation on the neural differentiation of ADSCs. Third-passaged ADSCs were differentiated to neural cell in differentiation medium during 16?d. The ADSCs were exposed to lead (0.1–100?µg/ml) before differentiation and during differentiation on days 1, 7 and 14. The cell viability was assessed by MTT assay after 48?h. Also expression of β-tubulin III protein and Nestin, NeuN, NF70, Synaptophysin genes were evaluated at the end of differentiation in all treated groups. The results showed that lead had no effect on viability of undifferentiated ADSCs but differentiating cells showed various sensitivities to lead exposure and cells were more vulnerable to lead exposure at early stage of differentiation. Also, lead exposure at different stages of differentiation had various effects on gene expressions. Our study indicated that neural cells differentiated from ADSCs in vitro are sensitive to neurotoxic effect of lead as well-known developmental neurotoxicant, and then ADSCs could be a candidate as an alternative method for assessing neurodevelopmental toxicity potential of chemicals.     

溶血卵磷脂对血管内皮细胞增殖及凋亡的影响

目的观测溶血卵磷脂(LPC)对血管内皮细胞增殖及凋亡的影响,从而探讨动脉硬化发生的机制。方法取体外培养的人脐静脉内皮细胞(HUVECs),在含不同浓度LPC(5、10、20mg/L)的培养基中分别培养6、12、24、48h,用四甲基偶氮唑蓝(MTT)比色法、流式细胞仪、荧光显微镜观测血管内皮细胞增殖及凋亡的变化。结果与正常对照组比较,LPC抑制内皮细胞增殖,促进细胞凋亡,且其作用呈时间-效应、浓度-效应依赖关系,但随着LPC浓度增加,细胞凋亡增加的同时细胞死亡比例也增加。结论LPC抑制血管内皮细胞增殖,促进细胞凋亡,可能是其致动脉粥样硬化机制之一。     

胎鼠神经干细胞培养方法的建立及药物对干细胞增殖的影响

目的建立神经干细胞培养模型，观察药物对其增殖能力的影响。方法建立大鼠胎脑神经干细胞的培养方法，并用MTT法和3H-胸腺嘧啶核苷参入法观察黄皮酰胺、丹酚酸A及人参皂苷Rg1等对第2代神经球细胞状态的影响。结果免疫细胞化学结果显示，培养的神经细胞具备干细胞的基本特性；MTT和液闪结果则表明，上述3种药物可不同程度地影响神经干细胞的存活率和/或增殖活性。结论本实验所建立的胚胎大鼠神经干细胞培养模型可以观察到一些有脑保护作用的药物对干细胞存活和增殖有一定影响。     

Effect of lead on proliferation and neural differentiation of mouse bone marrow-mesenchymal stem cells

Bone marrow-mesenchymal stem cells (MSCs) are considered to be an ideal source of stem cells for assessing the effects of environmental toxins on the proliferation, multipotency and differentiation of adult stem cells. The aim of this study was to investigate the effect of lead on the proliferation and neuronal differentiation of murine MSCs. MTT assay used in this study revealed that while the proliferation of MSCs is sensitive to higher than 10 μM lead, a 50% reduction in the rate of their proliferation can be achieved in the presence of 60 μM lead. The results of immunocytochemistry and RT–PCR showed that β-mercaptoethanol induced-neuronal differentiation is also reduced after the treatment of MSCs by 60 μM lead. Furthermore, the comet assay analysis of MSCs showed a substantial increase in DNA damage in the lead treated cells compared to the control. In conclusion our results revealed for the first time that lead is not only cytotoxic to the survival and proliferation of MSCs but also inhibits their differentiation to neurons in a dose-dependant manner. Therefore, MSCs appear to be an alternative method for assessing the cytotoxic effects of such environmental hazards.     

氯胺酮对胚胎大鼠培养神经干细胞增殖和细胞周期的影响

目的　探讨氯胺酮对体外培养的大鼠神经干细胞细胞增殖、细胞周期的影响。方法　采用MTT法检测氯胺酮对体外培养的大鼠神经干细胞细胞生长的抑制作用 ,流式细胞仪检测细胞周期分布。结果　氯胺酮对体外培养的大鼠神经干细胞细胞具有生长抑制作用 ,并存在量效关系。流式细胞仪分析表明G0 /G1期细胞百分率上升 ,S期细胞百分率下降。结论　氯胺酮对大鼠培养神经干细胞的增殖有抑制作用 ,其机制与细胞周期阻滞有关。     

托吡酯促进体外培养神经干细胞增殖的实验研究

目的:研究托吡酯对体外培养神经干细胞的促增殖作用。方法:取新生小鼠大脑进行神经干细胞原代培养,托吡酯按0.4、2、10μmol.L-13个量级(或3种浓度)加入神经干细胞培养基中,同时设立溶媒对照组和阳性对照组,通过神经球生成数目及MTT法定量比较,分析不同浓度托吡酯对神经干细胞分裂增殖的影响。结果:2、10μmol.L-1托吡酯组神经球数目分别为20.67±4.04和49.68±3.79;MTT比色结果分别为0.3546±0.0705和0.5018±0.0369,明显高于溶媒对照组(7.34±2.31、0.2880±0.0093,P<0.01)。结论:托吡酯具有促进神经干细胞增殖的作用。     

人胚胎神经干细胞体外培养及其增殖与分化的研究

目的 建立神经干细胞分离、培养及分化的鉴定技术，观察神经干细胞增殖、分化的特点。方法 从人胚胎海马区分离神经干细胞，采用无血清培养基，进行体外扩增培养、传代。采用免疫细胞化学法鉴定神经干细胞和分化的神经细胞；利用流式细胞仪和细胞生长曲线检测神经干细胞的增殖能力。结果 从人胚胎脑海马区分离的细胞具有增殖和多向分化潜能，可进行传代培养，获得的细胞团中大部分为nestin表达阳性细胞。贴壁分化后可以出现NSE、GFAP表达阳性的细胞。结论 用上述方法分离培养的细胞能表达nestin蛋白，具有自我更新和增殖能力，并具有向神经元、星形胶质细胞分化的潜能，具备神经干细胞的特征，可用于细胞移植等相关研究。     

Effect of leukemia inhibitory factor on embryonic stem cell differentiation： implications for supporting neuronal differentiation

AIM: Leukemia inhibitory factor (LIF), a pleiotropic cytokine, has been used extensively in the maintenance of mouse embryonic stem cell pluripotency. In this current work, we examined the effect of the LIF signaling pathway in embryonic stem (ES) cell differentiation to a neural fate. METHODS: In the presence of LIF (1000 U/mL), the production of neuronal cells derived from embryoid bodies (EB) was tested under various culture conditions. Inhibition of the LIF pathway was examined with specific inhibitors. The effects of cell apoptosis and proliferation on neural differentiation were examined. ES cell differentiation into three-germ layers was compared. RESULTS: Under various culture conditions, neuronal differentiation was increased in the presence of LIF. Blocking the LIF-activated STAT3 signaling pathway with specific inhibitors abolished the neuronal differentiation of ES cells, whereas inhibition of the LIF-activated MEK signaling pathway impaired the differentiation of ES cells toward a glial fate. LIF suppressed cell apoptosis and promoted cell proliferation during ES cell differentiation. LIF inhibited the differentiation of ES cells to both mesoderm and extraembryonic endoderm fates, but enhanced the determination of neural progenitors. CONCLUSION: These results suggest that LIF plays a positive role during the differentiation of ES cells into neuronal cells.