Sertoli细胞诱导大鼠胚胎中脑神经干细胞定向分化的研究

目的研究Sertoli细胞对胚胎中脑神经干细胞的营养及向多巴胺能神经元分化的诱导作用。方法将大鼠Sertoli细胞与胚胎13d大鼠中脑神经前体细胞体外共培养5、7、10、14d后,免疫荧光检测神经干细胞标记物Nestin、神经元前体细胞标记物β-Ⅲ tubulin、多巴胺能神经元标记物酪氨酸羟化酶(TH)的表达情况。结果随着共培养时间的延长,神经干细胞中nestin阳性细胞数量逐渐减少,β-Ⅲ tubulin阳性细胞数在共培养7d时较多,TH阳性的神经元在共培养10d时数量最多。而且在各时间段TH阳性细胞数均多于单独培养的神经前体细胞。结论Sertoli细胞能够诱导与其共培养的胚胎中脑神经干细胞定向分化为多巴胺能神经元。     

与Sertoli细胞共培养大鼠大脑皮质神经前体细胞分化中Notch信号相关基因表达分析

目的:检测与Sertoli细胞共培养条件下大鼠大脑皮质神经前体细胞分化过程中Notch信号相关分子的表达变化.方法:分离大鼠Sertoli细胞和大脑皮质神经前体细胞.神经前体细胞与Dertoli细胞共培养条件下,用Real-time PCR相对定量法,分别检测Notch受体Notch1、Notch2、Notch3、Notch4及其配体Delta1、Delta3、Jagged1、Jagged2,以及ngn1、hes1基因的表达变化.结果:培养细胞汇片后第5天,Sertoli细胞Notch1～4基本表达维持不变;其配体Jagged2表达较高,但不表达Delta1;同时也不表达ngn1、hes1.神经前体细胞Notch表达水平较高,尤以Notch1和Notch2为高;而其配体以Jagged1、Jagged2表达较高,前神经因子Hes1有较高表达,而Ngn1表达较低.细胞共培养条件下,Notch受体、配体以及Hes1与神经前体细胞组相比都有明显的下调,而Ngn1却相对有所提高.结论:Sertoli细胞可通过Notch配体的作用,调节神经前体细胞Notch信号分子的表达.在共培养条件下,Sertoli细胞对神经前体细胞Hes1表达有抑制作用,但对Ngn1有正向调节作用,从而影响神经前体细胞的分化.     

Desert Hedgehog诱导大鼠胚胎中脑神经前体细胞定向分化为多巴胺能神经元

目的 研究Desert Hedgehog(DHH)对胚胎中脑神经前体细胞(NPCs)向多巴胺能神经元分化的诱导作用。方法 大鼠DHH病毒上清感染COS7、NIH/3T3和9L细胞, 用免疫荧光、实时定量PCR和Western blot方法检测DHH表达。分离培养大鼠胚胎中脑神经前体细胞，免疫荧光鉴定神经前体细胞的增殖分化特性。条件细胞表达DHH成功后分别与上述NPCs共培养10d，免疫荧光检测酪氨酸羟化酶(TH)的表达。结果 DHH在COS7、NIH/3T3和9L细胞中成功表达；同时，分离培养的大鼠胚胎中脑神经前体细胞具有良好的增殖分化特性，但两者共培养10d后偶见TH阳性的细胞。结论 DHH编码的蛋白不能或不能单独诱导与其共培养的NPCs定向分化为多巴胺能神经元。     

大鼠大脑皮质神经前体细胞的分离培养及其增殖分化鉴定

目的:体外分离和培养大鼠大脑皮质神经前体细胞并进行增殖和分化鉴定。方法:分离2周龄大鼠皮质神经前体细胞,在含EGF、bFGF和GDNF的NSC培养基中进行体外培养,使用免疫细胞荧光染色技术对细胞的分化特性进行鉴定。结果:EGF、bFGF和GDNF可促进神经前体细胞的增殖及神经球的克隆形成,并获得了Nestin阳性的神经前体细胞,其可分化为分别表达β-Ⅲtubulin、GFAP和GalC的阳性细胞。结论:体外分离和培养的大脑皮质神经前体细胞,在含EGF、bFGF和GDNF的NSC培养基中培养,具有增殖分化的能力,有望应用于神经系统疾病的细胞移植治疗。     

新生大鼠不同脑区内神经前体细胞生物学特性比较

为了观察海马、中脑和顶叶皮质内神经前体细胞的体外生长特性及其分化后所产生的神经元的形态特征,本研究使用碱性成纤维细胞生长因子(bFGF)体外扩增细胞技术和克隆形成实验分析了神经前体细胞的自我更新特性;采用神经前体细胞和骨髓基质细胞共培养方式,通过免疫细胞化学染色方法,研究了神经前体细胞的分化特点。结果发现:(1)新生大鼠海马、中脑和顶叶皮质内的神经前体细胞,在体外的分裂增殖能力无明显区别;(2)新生大鼠海马、中脑和顶叶皮质内的神经前体细胞在相同的条件下,其后代细胞中,神经元和胶质细胞所占的比例基本相同,但不同脑区内神经前体细胞所产生的神经元的形态却表现出明显不同。这些结果提示新生大鼠不同脑区内神经前体细胞的分化潜能已有了一定限制。     

成年鼠大脑皮质损伤后神经前体细胞的增殖、迁移和分化

探讨皮质损伤后室管膜下区(SVZ)神经前体细胞增殖、迁移和分化的变化。在立体定位仪上纵切SD大鼠的大脑皮质,于手术后10d腹腔注射BrdU,分别于术后10、13、16、19和21d处死动物。用BrdU、nestin、GFAP和NSE免疫组化单标或双标染色方法,观察损伤后神经前体细胞增殖、迁移和分化的情况。结果显示:损伤后第10d,除损伤区出现大量BrdU阳性细胞外,SVZ背外侧角也聚集大量BrdU阳性细胞;第13d时,SVZ背外侧角的BrdU阳性细胞开始沿胼胝体向损伤区迁移;至第16d和19d,BrdU阳性细胞已迁移到SVZ背外侧角和损伤区之间;第21d时,BrdU阳性细胞已进到损伤区;BrdU阳性细胞为神经前体细胞,但未见分化为星形胶质细胞和神经元。结果提示机械性大脑皮质损伤可诱导SVZ背外侧角神经前体细胞增殖并引导向损伤区迁移,可能参与脑损伤后的修复。     

从多潜能干细胞诱导成神经前体细胞及其分化探讨

目的探讨诱导多潜能干细胞在体外分化为神经前体细胞。方法采用N2B27作为选择培养基,多步法贴壁培养把诱导多潜能干细胞诱导为神经前体细胞。结果免疫荧光染色发现,该细胞神经干细胞的标记物巢蛋白阳性,有极个别的β-微管蛋白Ⅲ(β-Tub-Ⅲ)阳性细胞。在分化培养基内培养7d后,β-Tub-Ⅲ阳性细胞增多。结论本实验初步表明,诱导多潜能干细胞在体外可以被诱导为有一定神经特征的神经前体细胞,该细胞有望用于细胞移植治疗缺血性脑损伤。     

人Muse细胞体外诱导为神经前体细胞的研究

探讨成人骨髓来源的Muse细胞体外诱导为神经前体细胞的技术方法。从健康成人骨髓中分离出骨髓基质细胞（hBMSCs）,利用流式细胞分选技术从中筛选出Muse细胞,采取免疫荧光细胞化学染色和qPCR技术鉴定Muse细胞的多能干细胞特性;通过神经诱导培养基体外诱导Muse细胞分化为神经前体细胞（Muse-NPCs）,采用免疫荧光细胞化学染色和qPCR技术鉴定其神经干细胞标志物表达情况。从hBMSCs中分选出约0.58%的Muse细胞,Muse细胞表达多能干细胞标志物SSEA-3、Nanog和Oct4,其mRNA表达水平均高于hBMSCs（P＜0.01）;诱导后的Muse-NPCs表达神经干细胞标志物Nestin、βIII-tubulin,其mRNA表达水平均高于hBMSCs及Muse 细胞（P＜0.01）。从成人骨髓中成功分离出具有多能干细胞特性的Muse细胞,用体外诱导形成Muse-NPCs,可为今后细胞治疗修复神经损伤提供新的种子细胞。     

神经干细胞向多巴胺能神经元诱导分化研究进展

在帕金森病的细胞移植治疗研究中 ,如何在体外获得足够的多巴胺能神经元一直是一个难以解决的问题。干细胞的研究让人们看到了希望的曙光 ,利用干细胞不仅能在体外大量得到相关的神经元 ,而且也可能解决胎脑移植引发的伦理问题。本文就神经干细胞向多巴胺能神经元诱导分化及相关因素的研究进展作一综述。     

不同化学物质对新生大鼠中脑神经前体细胞神经元生成的影响

目的：观察新生大鼠中脑神经前体细胞对不同化学物质的反应性,以期找到体外有效增加其神经元生成的化学物质。方法：建立新生大鼠中脑神经前体细胞的培养体系,分别被各种化学物质诱导分化,利用神经元特异性标记物进行免疫细胞化学染色,检测不同化学物质诱导神经元生成的比例。结果：白介素-1α促新生大鼠中脑神经前体细胞的神经元生成,天麻素、胶质源性神经营养因子和睫状神经营养因子呈抑制效应,雌二醇、葛根素、牛蒡子苷、人参皂甙Rg1无明显作用。结论：新生大鼠中脑神经前体细胞的分化方向可被环境信号调控。白介素-1α是上述化学物质中唯一有望增加植入后神经元产量的细胞因子。     

Developmental potential of human spermatogenic cells co-cultured with Sertoli cells.

BACKGROUND: Development of an in-vitro culture system capable of supporting human early germ cell differentiation would be important for treatment of azoospermic patients. METHODS: Sertoli cells, spermatogonia and spermatocytes were isolated from testicular biopsies of 61 non-obstructive azoospermic patients, and co-cultured using Vero cell conditioned medium only or supplemented with recombinant (r)FSH or rFSH plus testosterone. Germ cell purity was checked by fluorescent in-situ hybridization (FISH) analysis. RESULTS: Best results were achieved with both hormones, which elicited 6.9% of meiosis index and 22.7% of differentiation into normal late spermatids after 2-3 weeks of culture. In-vitro matured spermatids were microinjected into oocytes to study their developmental potential. Round spermatids elicited 37.5% of fertilization and 28.6% blastocyst rates. Abnormal elongating and elongated spermatids enabled 8.3 and 27.3% fertilization rates respectively, but none achieved the blastocyst stage. Normal elongating and elongated spermatids elicited 30.5% fertilization and 42.9% of blastocyst rates. FISH analysis showed sex chromosome anomalies in all embryos, except in the case of morulae from normal late spermatids. CONCLUSIONS: Results suggest that meiosis and spermiogenesis can be resumed in vitro, with normal differentiated spermatids showing a low fertilization potential but regular rates of blastocyst formation. However, most of the embryos did not reach the morula stage and showed major sex chromosome abnormalities.     

促红细胞生成素体外培养鼠胚脑皮质神经干细胞的分化

背景：促红细胞生成素最早作为生长因子被认识,近些年来其对中枢神经系统保护作用的体内研究较多。 目的：观察促红细胞生成素对体外培养大鼠胚脑皮质神经干细胞凋亡及分化的影响。 方法：无菌条件下取孕14 d SD大鼠胚脑皮质,体外先悬浮增殖培养后贴壁诱导分化。巢蛋白免疫细胞荧光染色检测神经干细胞,以微管相关蛋白2、神经胶质原纤维酸性蛋白检测神经干细胞分化。取第3代神经干细胞向培养基中添加0.5,5,50,500 U/mL的促红细胞生成素,另设不添加促红细胞生成素的对照组。应用半胱氨酸天冬氨酸蛋白酶3检测神经干细胞凋亡,微管相关蛋白2检测神经干细胞向神经元方向的分化。 结果与结论：加入≥5 U/mL促红细胞生成素,神经球内半胱氨酸天冬氨酸蛋白酶3表达显著下降(P < 0.01),分化培养后微管相关蛋白2阳性细胞较对照组明显升高(P < 0.01)。提示促红细胞生成素可降低体外培养鼠胚脑皮质神经干细胞的凋亡率,促进其神经干细胞向神经元方向分化。     

大鼠脊髓发育过程中神经干细胞的分化

目的:研究正常大鼠脊髓发育过程中神经干细胞的分化规律。方法:应用免疫荧光染色技术,检测Nestin、NeuN、MAP2、GFAP、CNPase阳性细胞在大鼠胚胎期及生后脊髓内的分布及变化情况。结果:胚胎发育早期,脊髓中央管、灰质、白质均可检测到Nestin阳性细胞,生后Nestin阳性细胞数量逐渐减少。大鼠脊髓神经元的发生呈现明显的背腹模式,孕14d(E14)脊髓内可检测到NeuN阳性细胞,E16 NeuN阳性细胞逐渐增多,腹侧NeuN阳性细胞核体积较大,分布较稀疏,背侧神经元细胞核体积较小,分布较密集。MAP2染色结果与NeuN一致。胶质细胞的分化、成熟在生后初期进行,P4可检测到GFAP及CNPase阳性细胞,主要分布于脊髓白质内,P30在脊髓灰质内可检测到GFAP阳性细胞,细胞分支较多且短。结论:正常大鼠脊髓发育中神经干细胞的分化呈现一定规律性,向神经元方向化较早且呈明显的背腹模式,胶质细胞的分化较晚。     

大鼠FasL+Sertoli细胞的分离与鉴定

为了将睾丸Sertoli细胞应用于细胞治疗,应用胶原酶、胰蛋白酶及脱氧核糖核酸酶消化制备睾丸Sertoli细胞,并对其做生活观察、透射电镜检查,了解其功能状态。SABC法标记Fas配体和卵泡刺激素受体的表达情况,对睾丸Sertoli细胞加以鉴定。培养的睾丸Sertoli细胞,形态完整,细胞器和细胞核保持良好,有丰富的线粒体、内质网、高尔基复合体和溶酶体,功能状态良好。且高度表达Fas配体和卵泡刺激素受体,出现优势生长现象。Fas配体阳性的睾丸Sertoli细胞可以作为联合移植的供体,发挥其免疫赦免作用。     

Differentiation of neural stem cells into cells of oligodendroglial lineage

We described three different conditions that induce differentiation of dissociated neural stem cells derived from mouse embryonic CNS. In the first set of experiments, where the cell differentiation was triggered by cell adhesion, removal of growth factors and serum-supplemented medium, only sporadic neuronal and astroglial cells survived longer than two weeks and the latter formed a monolayer. When differentiation was induced in serum-free medium supplemented with retinoic acid, rapid and massive cell death occurred. A prolonged survival was observed in cultivation medium supplemented with serum and growth factors EGF plus FGF-2. One third of the cells did not express cell differentiation markers and were responsible for an increase in cell numbers. The remaining cells differentiated and formed the astrocytic monolayer on which occasional neuronal cells grew. One third of the differentiated phenotypes were represented by cells of oligodendroglial lineage. Differentiation of oligodendroglial cells occurred in a stepwise mechanism because the culture contained all successive developmental stages, including oligodendrocyte progenitors, preoligodendrocytes and immature and mature oligodendrocytes. Maturing oligodendrocytes displayed immunocytochemical and morphological features characteristic of cells that undergo physiological development. The cultivation conditions that supported growth and differentiation of neural stem cells were optimal for in vitro developmental studies and the production of oligodendroglial cells.     

Differentiation markers of Sertoli cells and germ cells in fetal and early postnatal human testis

The definition of the temporal sequence of appearance of fetal markers during prenatal and early postnatal development in Sertoli and germ cells may be important for understanding the mechanisms underlying their reexpression in disorders of the adult testis. For this reason, we studied the expression of Sertoli and germ cell markers in 25 human testes spanning a period from 8 gestational weeks to 4 years. Well-characterized antibodies were employed to anti-Müllerian hormone (AMH), cytokeratin 18 (CK18), vimentin (VIM), M2A-antigen (M2A), germ cell alkaline phosphatase (GCAP), and somatic angiotensin-converting enzyme (sACE) on formalin-fixed and microwave-pretreated paraffin sections. In Sertoli cells, AMH and VIM were consistently present. While VIM and CK18 were coexpressed in embryonic testes, CK18 was progressively downregulated and completely absent from the 20th gestational week. M2A was absent or moderately expressed in fetal Sertoli cells but increased during further development. In germ cells, M2A was consistently found in primordial germ cells (PGCs) as well as in M- and T₁-prespermatogonia. In contrast, sACE and GCAP were absent from PGCs but were a distinct feature of late M- and early T₁-prespermatogonia and appeared predominantly between the 18th and the 22nd gestational weeks. Both T₂-prespermatogonia and postnatal prespermatogonia were devoid of any marker. While CK18 represents a differentiation marker for fetal Sertoli cells, M2A, GCAP, and sACE can be used as differentiation markers for the discrimination of different germ cell types during human prespermatogenesis. Because various immunophenotypes reflect distinct differentiation stages, this knowledge may be important for understanding adult testicular pathology.     

人诱导性多能干细胞定向分化为神经干细胞的实验研究

目的 观察人诱导性多能干细胞（iPS细胞）定向分化为神经干细胞（NSCs）的潜能。方法 用维甲酸（RA）诱导人iPS细胞向NSCs分化。倒置显微镜下观察iPS细胞的形态变化,RT-PCR检测NANOG, OCT4, SOX2的表达;免疫组织化学方法检测NESTIN、SOX2、β-TUBULIN Ш和GFAP的表达。结果RA诱导后第4天,贴壁的拟胚体出现了早期神经祖细胞特有的神经管样结构并不断增多,细胞表达神经巢蛋白NESTIN,而对照组未观察到神经管样结构。神经管样结构内的细胞能分化为β-TUBULIN Ш阳性的神经元,但GFAP阳性的星形胶质细胞少见。结论 人iPS细胞具有定向分化为NSCs的潜能,并能模拟神经发育过程。