西他滨联合丙戊酸钠对白血病细胞株的促分化效应研究

目的 探讨地西他滨(decitabine,DCA)和丙戊酸钠(valproic acid,VPA)联用对白血病细胞株HL-60的促分化影响。方法 设立分组如下：对照组,DCA A组(1.0 μmol·L^-1),DCA B组(4.0 μmol·L^-1),VPA组(2.0 mmol·L^-1),联合用药A组(DCA 1.0 μmol·L^-1+VPA 2.0 mmol·L^-1),联合用药B组(DCA 4.0 μmol·L^-1+VPA 2.0 mmol·L^-1),作用48 h。流式细胞术检测CD34、CD117 MFI以及CD11b、CD14表达率。结果 联合用药A、B组的CD117和CD34 MFI显著低于其各自的单药组(P<0.01);联合用药A组的CD11b和CD14表达率和联合用药B组CD11b表达率显著低于其各自的单药组(P<0.01)。结论 VPA与DCA联用对HL-60细胞具促分化作用。     

丁苯酞对神经干细胞向神经细胞分化的促进作用

目的 研究丁苯酞通过PI3K-AKT信号通路促进神经干细胞向神经细胞分化的作用。方法 分离培养SD大鼠胚胎脑皮质层的神经干细胞,采用分化专用完全培养基培养后,通过光镜下观察和Nestin蛋白免疫荧光法进行鉴定。设置对照组和实验组,其中实验组添加丁苯酞辅助分化,分为丁苯酞低剂量组（1 μmol·L^-1）、中剂量组（5 μmol·L^-1）和高剂量组（10 μmol·L^-1）,作用24 h后,CCK-8法检测神经干细胞的细胞活力,碱性磷酸酶染色法检测神经干细胞的分化能力,免疫荧光法检测神经细胞分化程度,RT-qPCR法检测转录因子SOX2、PAX6和NeuN的mRNA表达水平,Western-blot及RT-qPCR检测PI3K-AKT信号通路的表达。结果 丁苯酞干预后神经干细胞活力提高,分化能力提高,碱性磷酸酶试验呈强阳性,转录因子SOX2、PAX6和NeuN的mRNA表达水平增高,PI3K-AKT信号通路蛋白和mRNA表达水平均增高,且呈现剂量依赖性。结论 丁苯酞可以促进神经干细胞向神经细胞分化,其作用机制可能与PI3K-AKT的激活有关。     

星形胶质细胞对神经干细胞分化的影响实验研究

目的研究星形胶质细胞对神经干细胞分化的影响。方法随机在我院动物实验中心选取3只大鼠为研究对象,将本次实验均分为普通星形胶质细胞的培养的对照组以及星形胶质细胞与神经干细胞互不接触状态下共同培养的实验组。对比两组星形胶质细胞对神经干细胞分化的影响效果。结果实验组的纯化星形胶质细胞胶质纤维酸性蛋白抗体标记为阳性,其细胞纯度高到96%,且在神经元特异性烯醇化酶阳性细胞与酪氨酸羟化酶阳性细胞均比对照组多。结论星形胶质细胞不仅可以加快神经干细胞向神经元细胞的分化以及向多巴胺神经元细胞的分化,而且可以延长神经元存活时间,降低神经元凋亡率。     

胚胎大鼠神经干细胞体外分化的激光共聚焦显微镜观察

目的:采用激光扫描共聚焦显微镜观察体外培养胎鼠大脑皮质神经干细胞(neural stem cells,NSCs)分化情况。方法:利用无血清培养方法,分离培养胚胎大鼠大脑NSCs,进行体外扩增培养、传代;采用溴脱氧尿嘧啶核苷(bromodeoxyuridine,BrdU)掺入、双重免疫荧光细胞化学标记方法和激光扫描共聚焦显微镜,用神经细胞的特异性抗体(神经元β-微管蛋白、胶质纤维酸性蛋白),鉴定NSCs向神经元与星形胶质细胞分化的情况。结果:从胎鼠大脑皮质及皮质下分离的组织,经原代和传代培养均可形成细胞克隆,并表达神经上皮干细胞蛋白(Nestin)抗原。在血清诱导下,分化后的细胞表达神经元、星形胶质细胞2种神经细胞的特异性抗原,NSCs分化为星形胶质细胞神经元的比例分别为(43.70±8.55)%和(23.00±3.69)%。结论:从胎鼠大脑皮质分离出的细胞可获得呈集落样生长的神经干细胞团,并能表达NSCs的特异性抗原;激光扫描共聚焦显微镜可清晰地观察到培养细胞具有分化为神经元和星形胶质细胞的潜能。     

人脐带问充质干细胞体外培养、鉴定及其诱导分化的研究

目的通过体外分离、培养及鉴定人脐带间充质干细胞（humanumbilicalcordmesenchymalstemcells,hUCMSCs）,探讨其多向分化潜能。方法取正常足月新生儿脐带,采用组织贴壁培养法分离原代hUCMSCs,观察细胞生长形态。采用流式细胞仪技术检测hUCMSCs细胞表型及细胞周期。通过成神经细胞诱导和成脂肪细胞诱导,鉴定hUCMSCs的多向诱导分化能力。结果成功分离和培养hUCMSCs原代细胞,经流式细胞仪鉴定高表达间质细胞标志CD44和CDl05,阳性率为96．73％和96．10％,整合素受体CD29阳性率为99．53％;低表达造血系标志CD34和CD45阳性率为0．80％和1．91％,人白细胞抗原HLA-DR阳性率为1．41％。细胞周期检测hUCMSCs主要处于G0／G1期。hUCMSCs成神经细胞诱导,出现神经元样细胞;免疫组化检测神经巢蛋白（Nestin）呈阳性表达。hUCMSCs成脂肪细胞诱导,出现空泡样脂肪滴,油红O染色可见脂质沉积。结论hUCMSCs具有多向分化潜能,可跨胚层诱导分化为多种组织类型的细胞。     

黄芩苷下调p-STAT3诱导神经干细胞向神经元分化*

目的观察黄芩苷促进神经干细胞（NSCs）体外向神经元分化过程中信号传导子与转录激活子(STAT)的磷酸化蛋白表达水平。方法从孕14～15 d的SD大鼠胚胎大脑皮质中分离NSCs,体外培养传代,实验用第3代NSCs。随机分为对照组,低、中、高黄芩苷组（分别含黄芩苷7.5、15、30μmol/L）,白血病抑制因子（LIF）+碱性成纤维细胞生长因子（bFGF）组和黄芩苷+LIF+bFGF组。培养6 d后,细胞免疫荧光化学染色法观察各组中微管相关蛋白2(MAP-2)、胶质纤维酸性蛋白（GFAP）表达水平。培养2 h与6 d后,用Western blot方法观察各组中STAT3蛋白磷酸化水平。结果黄芩苷可使NSCs中MAP-2表达增加,GFAP表达减弱;LIF+bFGF可促进NSCs中GFAP表达增加;黄芩苷可抑制LIF+bFGF引起的NSCs中GFAP的表达增加。黄芩苷可下调NSCs中STAT3蛋白磷酸化水平;LIF+bFGF可上调NSCs中STAT3蛋白磷酸化水平;黄芩苷可抑制LIF+bFGF引起的NSCs中STAT3蛋白磷酸化水平的上调（P＜0.05）。结论黄芩苷可诱导NSCs向神经元分化并抑制其向星形胶质细胞分化,该作用可能经下调NSCs中STAT3的磷酸化水平来实现。     

影响丙戊酸钠血药浓度波动的因素及应对措施

目的 :探讨影响丙戊酸钠血药浓度波动的因素 ,提高丙戊酸钠血药浓度检测的有效性及可利用性。方法 :归纳总结影响丙戊酸钠血药浓度波动的因素 ,提出应对措施。结果 :服药时间、采血时间、监测时机、剂型及制剂质量、患者依从性、合并用药、患者生理和病理指标等均为影响丙戊酸钠血药浓度波动的因素。结论 :在癫痫患者长期服药治疗过程中 ,医师、患者、药师应互相沟通 ,建立监测档案 ,密切注意影响丙戊酸钠血药浓度波动的因素 ,以确保患者用药的安全、有效     

The Aromatic Amino Acid Residues of Tumor Necrosis Factor Receptor-1-Derived Peptide are Important for Promoting Differentiation of Neural Stem Cells

Neural stem cells have the self-renewal capacity and the ability to differentiate into all types of nerve cells. We previously reported that the tumor necrosis factor receptor-1-derived peptide promotes neural differentiation of fetal rat hippocampal neural stem cells. The tumor necrosis factor receptor-1-derived peptide contains six aromatic amino acid residues among its 14 amino acid residues. To clarify the role of these aromatic amino acid residues in the action of tumor necrosis factor receptor-1-derived peptide on neural stem cells, we synthesized mutant peptides, in which aromatic residues were substituted with alanine, and we assessed their effects. Substitution of the tyrosine residue at position 103 (Y¹⁰³) or 106 (Y¹⁰⁶), the tryptophan residue at position 107 (W¹⁰⁷), or the phenylalanine residue at position 112 (F¹¹²) or 115 (F¹¹⁵), decreased the ability of the peptide to promote neurite outgrowth of neural stem cells depending on their concentration. These data suggest that although all five aromatic amino acid residues mediate the action of the tumor necrosis factor receptor-1-derived peptide, their order of importance in this activity is F¹¹⁵ > Y¹⁰³ > W¹⁰⁷ > Y¹⁰⁶ and F¹¹².     

SRC-1基因在小鼠神经干细胞分化过程中的变化

目的观察类固醇受体辅助活化因子-1(SRC-1)基因在小鼠神经干细胞(NSCs)体外培养分化过程中表达的变化。方法用机械分离和酶消化法从1~3 d小鼠大脑皮质获取NSCs原代细胞,体外培养获神经球,传代并消化,经血清诱导神经球细胞分化。形态学、细胞免疫荧光实验观察神经球形态、Nestin表达鉴定NSCs;抗体分别标记神经元、星形胶质细胞,检测细胞分化d 3、9的细胞类型。RT-qPCR和免疫印迹法检测细胞分化d 0、3、9 SRC-1基因mRNA和蛋白的表达。结果新生小鼠大脑皮质获取的细胞,体外培养能扩增形成神经球,Nestin阳性表达。NSCs分化d 3主要为神经元,d 9主要为星形胶质细胞。与NSCs分化d 0相比,SRC-1表达在分化d 3明显升高,在分化d 9明显降低。 结论 成功分离并获取新生小鼠皮质NSCs。在NSCs分化中,SRC-1表达量有明显变化,分布依次为神经元>NSCs>星形胶质细胞。     

骨髓基质细胞和神经干细胞体外共培养的实验研究

目的:研究神经干细胞(NSCs)和骨髓基质细胞(MSCs)共培养时对各自分化的影响。方法:将2种细胞按接种数目分为5组,A组为NSCs∶MSCs=105∶0;B组为NSCs∶MSCs=105∶104;C组为NSCs∶MSCs=105∶105;D组为NSCs∶MSCs=104∶105;E组为NSCs∶MSCs=0∶105。培养7d后分别进行5-溴-2-脱氧尿嘧啶(BrdU)和神经元特异性烯醇化酶(NSE)、胶质细胞纤维酸性蛋白(GFAP)、微管相关蛋白2(MAP2)、半乳糖神经酰胺(GalC)免疫细胞化学双染色。结果:随着MSCs比例的提高,各组BrdU和NSE或MAP2的双阳性细胞表达差异有统计学意义(P<0.05),且B、C及D组分别与A组比较差异亦有统计学意义(均P<0.01);随NSCs比例的增高,B、C、D组NSE、MAP2和GFAP双阳性MSCs表达逐渐增高(均P<0.01)。结论:MSCs可以促进NSCs分化为神经元,而且在NSCs诱导下部分MSCs可以转化为神经元和星形细胞。     

变活霉素诱导人红白血病细胞K—562向红系方向分化作用的研究

新蒽环类抗生素变活霉素由五种组分组成：变活霉素A、B、C、D和7－脱氧变活霉酮A。变活霉素各组分体外抑制人红白血病K－562细胞生长和诱导其分化活性各不相同，经联苯胺染色，变活霉素C诱导后K－562细胞血红蛋白表达百分率为86%。联苯胺染色阳性细胞最大值出现在第五或第六天；去除药物后，分化细胞为部分可逆性；诱导细胞失去在软琼脂上克隆生长的能力。与其它已知蒽环类抗生素比较，变活霉素C的促分化动力学变化与阿霉素、表阿霉素和柔红霉素相似，但变活霉素C较阿克拉霉素A促分化活性要强。构效关系研究表明，蒽环类抗生素的促分化活性与蒽环上C3、C11或C9或C10位的取代基以及C7位的取代糖有很大关系。     

变活霉素诱导人红白血病细胞K－562向红系方向分化作用的研究

新蒽环类抗生素变活霉素由五种组分组成：变活霉素Ａ、Ｂ、Ｃ、Ｄ和７－脱氧变活霉酮Ａ。变活霉素各组分体外抑制人红白血病Ｋ－５６２细胞生长和诱导其分化活性各不相同。经联苯胺染色，变活霉素Ｃ诱导后Ｋ－５６２细胞血红蛋白表达百分率为８６％。联苯胺染色阳性细胞最大值出现在第五或第六天；去除药物后，分化细胞为部分可逆性；诱导细胞失去在软琼脂上克隆生长的能力。与其它已知蒽环类抗生素比较，变活霉素Ｃ的促分化动力学变化与阿霉素、表阿霉素和柔红霉素相似。但变活霉素Ｃ较阿克拉霉素Ａ促分化活性要强。构效关系研究表明，蒽环类抗生素的促分化活性与蒽环上Ｃ＿３、Ｃ＿１１或Ｃ＿９或Ｃ＿１０位的取代基以及Ｃ＿７位的取代糖有很大关系。     

Combination of Hyaluronic Acid Hydrogel Scaffold and PLGA Microspheres for Supporting Survival of Neural Stem Cells

Purpose

To develop a biomaterial composite for promoting proliferation and migration of neural stem cells (NSCs), as well as angiogenesis on the materials, to rescue central nervous system (CNS) injuries.

Methods

A delivery system was constructed based on cross-linked hyaluronic acid (HA) hydrogels, containing embedded BDNF and VEGF-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres for controlled delivery and support for NSCs in the CNS. The surface morphologies were evaluated by SEM and AFM, mechanical property was investigated by rheological tests, and release kinetics were performed by ELISA. Bioactivity of released BDNF and VEGF was assessed by neuron and endothelial cell culture, respectively. Compatibility with NSCs was studied by immunofluorescent staining.

Results

Release kinetics showed the delivery of BDNF and VEGF from PLGA microspheres and HA hydrogel composite were sustainable and stable, releasing ~20–30% within 150 h. The bioactivities preserved well to promote survival and growth of the cells. Evaluation of structure and mechanical properties showed the hydrogel composite possessed an elastic scaffold structure. Biocompatibility assay showed NSCs adhered and proliferated well on the hydrogel.

Conclusions

Our created HA hydrogel/PLGA microsphere systems have a good potential for controlled delivery of varied biofactors and supporting NSCs for brain repair and implantation.

     

Endogenous Neural Stem Cells in the Adult Brain

Despite progress in our understanding molecular mechanisms of neuronal cell death in many central nervous system (CNS) diseases, widely effective treatments remain elusive. Recent studies have shown that neural stem cells (NSCs) are present in the subventricular zone (SVZ) lining the lateral ventricles and the subgranular zone (SGZ) of the hippocampal dentate gyrus (DG) in adult mouse, rat, nonhuman primate, and human brain. Newly generated cells in the SGZ can differentiate into mature, functional neurons and integrate into the DG as granule cells, which are involved in memory formation. In addition, many CNS diseases can stimulate the proliferation of neuronal stem/progenitor cells located in the SVZ and SGZ of the adult rodent brain, and the resulting newborn cells migrate into damaged brain regions, where they express mature neuronal markers. Therefore, it might be possible for damaged cells to be replaced from endogenous neural stem cell pools. However, the capacity of self-repair is obviously not enough. Proliferation, migration, and neuronal differentiation of endogenous NSCs could be manipulated by pharmaceutical tools to reach the adequate benefits for the treatment of CNS diseases. This work is supported in part by National Institute of Health (NIH) grant AG21980 (K.J.).     

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。     

Characterization of Ionic Currents in Human Neural Stem Cells

The profile of membrane currents was investigated in differentiated neuronal cells derived from human neural stem cells (hNSCs) that were obtained from aborted fetal cortex. Whole-cell voltage clamp recording revealed at least 4 different currents: a tetrodotoxin (TTX)-sensitive Na⁺ current, a hyperpolarization-activated inward current, and A-type and delayed rectifier-type K⁺ outward currents. Both types of K⁺ outward currents were blocked by either 5 mM tetraethylammonium (TEA) or 5 mM 4-aminopyridine (4-AP). The hyperpolarization-activated current resembled the classical K⁺ inward current in that it exhibited a voltage-dependent block in the presence of external Ba²⁺ (30µM) or Cs⁺ (3µM). However, the reversal potentials did not match well with the predicted K⁺ equilibrium potentials, suggesting that it was not a classical K⁺ inward rectifier current. The other Na⁺ inward current resembled the classical Na⁺ current observed in pharmacological studies. The expression of these channels may contribute to generation and repolarization of action potential and might be regarded as functional markers for hNSCs-derived neurons.     

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。     

Feridex标记胎盘来源的间充质干细胞分化为神经干细胞的实验研究

目的分离胎盘组织来源的间充质干细胞并诱导分化为神经干细胞,以期找到能成功标记神经干细胞的方法。方法将胎盘组织剪碎后消化、培养,加入神经干细胞诱导因子10ng/mL表皮生长因子（EGF）＋10ng/mL重组人碱性成纤维生长因子（bFGF）＋DMEM/F12,并分别添加相应浓度的血清,预诱导3d后加入DMEM/F12＋0.1μmol/L全反式维甲酸（RA）,10ng/mL胶质细胞系源性神经营养因子（GDNF）＋10ng/mL脑源性神经营养因子（BDNF）进行正式诱导7d。结果诱导10d后用Feridex标记诱导后的细胞,普鲁士蓝染色显示90%以上的干细胞胞质内出现细小的蓝色铁颗粒,Nestin染色显示阳性。结论胎盘来源的间充质干细胞能成功诱导为神经干细胞,且Feridex可成功标记诱导后的细胞。     

依达拉奉对谷氨酸所致神经干细胞损害的保护作用

目的探讨依达拉奉对谷氨酸所致神经干细胞损害的保护作用及机制。方法取大鼠13.5 d胚胎皮质,提取神经干细胞,分为谷氨酸处理组(500μmol/L)、依达拉奉干预组(500μmol/L谷氨酸+500 ng/mL依达拉奉)和正常对照组。谷氨酸及依达拉奉处理24 h后,应用光学显微镜高倍下观察各组细胞的形态和数量;并对各组细胞作DAPI及TUNEL染色,计数阳性细胞。结果与正常对照组比较,谷氨酸处理组细胞的数量减少(P<0.05);依达拉奉组细胞的数量较谷氨酸组明显增多(P<0.05)。谷氨酸处理组的TUNEL阳性细胞明显多于正常对照组(P<0.05),依达拉奉组的TUNEL阳性细胞明显少于谷氨酸组(P<0.05)。结论依达拉奉通过拮抗谷氨酸诱导的细胞凋亡对谷氨酸所致的神经干细胞损害起到保护作用。