Correlation between receptor-interacting protein 140 expression and directed differentiation of human embryonic stem cells into neural stem cells

Overexpression of receptor-interacting protein 140（RIP140） promotes neuronal differentiation of N2 a cells via extracellular regulated kinase 1/2（ERK1/2） signaling.However,involvement of RIP140 in human neural differentiation remains unclear.We found both RIP140 and ERK1/2 expression increased during neural differentiation of H1 human embryonic stem cells.Moreover,RIP140 negatively correlated with stem cell markers Oct4 and Sox2 during early stages of neural differentiation,and positively correlated with the neural stem cell marker Nestin during later stages.Thus,ERK1/2 signaling may provide the molecular mechanism by which RIP140 takes part in neural differentiation to eventually affect the number of neurons produced.

In vitro culture and differentiation of rat embryonic midbrain-derived neural stem cells

BACKGROUND： Midbrain-derived neural stem cells （mNSCs） can differentiate into functional mature dopaminergic neurons. The mNSCs are considered the ideal choice for cell therapy of Parkinson＇s disease. OBJECTIVE： To isolate rat embryonic mNSCs and to observe the differentiation characteristics of mNSCs induced by cell growth-promoting factors. DESIGN, TIME AND SETTING： An in vitro cell culture study based on the molecular biology of nerve cells was carried out at the Institute of Clinical Medicine, China-Japan Friendship Hospital （China） from March to November 2007. MATERIALS： Sprague Dawley rats at embryonic day 14 were used in this study. Nestin antibody, β-Ⅲ tubulin antibody, glial fibrillary acidic protein （GFAP） antibody and cyclic nucleotide 3＇-phosphohydrolase （CNPase） antibody were provided by Abcam; DMEM/F12 medium and N2 supplement were provided by Invitrogen; epidermal growth factor （EGF） and fibroblast growth factor-2 （FGF2） were provided by R＆D Systems. METHODS： The ventral mesencephalon was dissected from embryonic day 14 rat embryos. By trypsin digestion and mechanical separation, the brain tissue was triturated into a fine single-cell suspension. The cells were cultured in 5 mL serum-free medium containing DMEM/FI 2, 1% N： supplement, 20 ng/mL EGF and FGF2. The mNSCs at the third generation were coated with 10ug/mL polylysine and induced to differentiate in the DMEM/F12 supplemented with 1% fetal bovine serum and 1% N2. MAIN OUTCOME MEASURES： The neural spheres of the third passage were identified by nestin immunofluorescence; at the same time, the cells were induced to differentiate, and the types of differentiated cell were identified by immunofluorescence for β Ⅲ tubulin, GFAP and CNPase. RESULTS： Seven days after primary culture, a great many neurospheres could be obtained by successive pasage. Immunofluorescence assays showed that the neurospheres were nestin positive, and after differentiation, the cells expressed GFAP, CNPase and β -Ⅲ-tubulin. CONCLUSION： Embryonic day 14 rat mNSCs can differentiate into neuron-like cells and glial cells following induction by EGF, FGF2 and N： additive.

Cell cycle exit and neuronal differentiation 1-engineered embryonic neural stem cells enhance neuronal differentiation and neurobehavioral recovery after experimental traumatic brain injury

Our previous study showed that cell cycle exit and neuronal differentiation 1(CEND1)may participate in neural stem cell cycle exit and oriented differentiation.However,whether CEND1-transfected neural stem cells can improve the prognosis of traumatic brain injury remained unclear.In this study,we performed quantitative proteomic analysis and found that after traumatic brain injury,CEND1 expression was downregulated in mouse brain tissue.Three days after traumatic brain injury,we transplanted CEND1-transfected neural stem cells into the area surrounding the injury site.We found that at 5 weeks after traumatic brain injury,transplantation of CEND1-transfected neural stem cells markedly alleviated brain atrophy and greatly improved neurological function.In vivo and in vitro results indicate that CEND1 overexpression inhibited the proliferation of neural stem cells,but significantly promoted their neuronal differentiation.Additionally,CEND1 overexpression reduced protein levels of Notch1 and cyclin D1,but increased levels of p21 in CEND1-transfected neural stem cells.Treatment with CEND1-transfected neural stem cells was superior to similar treatment without CEND1 transfection.These findings suggest that transplantation of CEND1-transfected neural stem cells is a promising cell therapy for traumatic brain injury.This study was approved by the Animal Ethics Committee of the School of Biomedical Engineering of Shanghai Jiao Tong University,China(approval No.2016034)on November 25,2016.

Silk Fibroin Scaffolds Direct Neural and Glial Differentiation from Embryonic Stem Cells

Spinal cord injury repair is one of the major challenges in medicine,as it can lead to permanent loss of function of central nervous system and damage to other function of the body.Stem cell transplantation together with tissue engineering is increasingly becoming a potential choice of treatment.However,direct transplantation of stem cells without scaffolds has yielded poor clinical outcome.Here we show a strategy of using mouse embryonic stem cells(ESCs)cultured within a silk fibroin(SF)based,three-dimensional scaffold with oriented channels by a directional temperature field freezing technique and lysophilization.We find that the ESCs maintained proliferation and migrated in the scaffolds and the cells migrated fastest along the SF channels.SF scaffolds contributed to ESC differentiation into neural and glial cell like cells and expressions of the neural and glial cell markers MAP2 and GFAP were greatly elevated when retinoic acid was used as an inducing factor.Our results suggest that this approach may offer some hope in the future for spinal cord injury repair using SF scaffolds and ESCs.

Differentiation of neuron-like cells from mouse parthenogenetic embryonic stem cells

Parthenogenetic embryonic stem cells have pluripotent differentiation potentials, akin to fertilized embryo-derived embryonic stem cells. The aim of this study was to compare the neuronal differentiation potential of parthenogenetic and fertilized embryo-derived embryonic stem cells. Before differentiation, karyotype analysis was performed, with normal karyotypes detected in both parthenogenetic and fertilized embryo-derived embryonic stem cells. Sex chromosomes were identified as XX. Immunocytochemistry and quantitative real-time PCR detected high expression of the pluripotent gene, Oct4, at both the mRNA and protein levels, indicating pluripotent differentiation potential of the two embryonic stem cell subtypes. Embryonic stern cells were induced with retinoic acid to form embryoid bodies, and then dispersed into single cells. Single cells were differentiated in N2 differentiation medium for 9 days. Immunocytochemistry showed parthenogenetic and fertilized embryo-derived embryonic stem cells both express the neuronal cell markers nestin, ~lll-tubulin and myelin basic protein. Quantitative real-time PCR found expression of neuregenesis related genes （Sox-1, Nestin, GABA, Pax6, Zic5 and Pitxl） in both types of embryonic stem cells, and Oct4 expression was significantly decreased. Nestin and Pax6 expression in parthenogenetic embryonic stem cells was significantly higher than that in fertilized embryo-derived embryonic stem cells. Thus, our experimental findings indicate that parthenogenetic embryonic stem cells have stronger neuronal differentiation potential than fertilized embryo-derived embryonic stem cells.

Noggin versus basic fibroblast growth factor on the differentiation of human embryonic stem cells

The difference between Noggin and basic fibroblast growth factor for the neural precursor differen- tiation from human embryonic stem cells has not been studied. In this study, 100 tJg/L Noggin or 20 IJg/L basic fibroblast growth factor in serum-free neural induction medium was used to differen- tiate human embryonic stem cells H14 into neural precursors using monolayer differentiation. Two weeks after induction, significantly higher numbers of neural rosettes formed in the Noggin-induced group than the basic fibroblast growth factor-induced group, as detected by phase contrast micro- scope. Immunofluorescence staining revealed expression levels of Nestin, [3-111 Tubulin and Sox-1 were higher in the induced cells and reverse-transcription PCR showed induced cells expressed Nestin, Sox-1 and Neurofilament mRNA. Protein and mRNA expression in the Noggin-induced group was increased compared with the basic fibroblast growth factor-induced group. Noggin has a greater effect than basic fibroblast growth factor on the induction of human embryonic stem cell differentiation into neural precursors by monolayer differentiation, as Noggin accelerates and in- creases the differentiation of neural precursors.

Morphogenesis of human embryonic stem cells into mature neurons under in vitro culture conditions

AIM To describe the morphogenesis of different neuronal cells from the human embryonic stem cell(h ESC) line,SCT-N,under in vitro culture conditions.METHODS The directed neuronal cell line was produced from a single,spare,pre-implantation stage fertilized ovum that was obtained during a natural in vitro fertilization process. The h ESCs were cultured and maintained as per our proprietary in-house technology in a Good Manufacturing Practice,Good Laboratory Practice and Good Tissue Practice compliant laboratory. The cell line was derived and incubated in aerobic conditions. The cells were examined daily under a phase contrast microscope for their growth and differentiation. RESULTS Different neural progenitor cells(NPCs) and differentiating neurons were observed under the culture conditions. Multipotent NPCs differentiated into all three types of nervous system cells,i.e.,neurons,oligodendrocytes and astrocytes. Small projections resembling neurites or dendrites,and protrusion coming out of the cells,were observed. Differentiating cells were observed at day 18 to 20. The differentiating neurons,neuronal bodies,axons,and neuronal tissue were observed on day 21 and day 30 of the culture. On day 25 and day 30,prominent neurons,axons and neuronal tissue were observed under phase contrast microscopy. 4',6-diamidino-2-phenylindole staining also indicated the pattern of differentiating neurons,axonal structure and neuronal tissue. CONCLUSION This study describes the generation of different neuronal cells from an h ESC line derived from biopsy of blastomeres at the two-cell cleavage stage from a discarded embryo.

Histone deacetylase inhibitor promotes differentiation of embryonic stem cells into neural cells in adherent monoculture

Background Embryonic stem （ES） cells poss unlimited self-renewal capacity and the ability to differentiate into cell of all three germ layers in vitro. Induced differentiation of ES cells to neural lineage cells has great potential in basic study of neurogenesis and regeneration therapy of neurodegenerative diseases. Histone deacetylase （HDAC） inhibitors enhance histone acetylation so that globularly activate gene expression and may initiate multilineage differentiation. In this study,we aimed to develop a method to induce the differentiation of ES cells to neural cells combining HDAC inhibition and neural cellselection.Methods In this study, we used HDAC inhibitor sodium butyrate （NAB） to induce the differentiation of mouse embryonic stem cells to neural cells through monolayer culture. After differentiation initiation by histone deacetylase inhibitor sodium butyrate, neural cells were induced and selected with a serum free culture system. Results Homogeneous neurons without glial cells demonstrated by molecular marker expression were differentiated with the method. The resultant neurons were excitable. Conclusion The method combined differentiation induction effect of HDAC inhibitors and selective culture system to derive neural cells from ES cells, and implied the involvement of epigenetic regulation in neural differentiation.

TGF-β receptors in mouse ES-5 cells and their differentiated derivatives

By radioreceptor binding studies with iodinated TGF-β1, it has been shown that an undifferentiated ES-5 cell expresses approximately 3270 receptors with a dissociation constant Kd=130pM, but after the induction of differenti-ation by retinoic acid and dBcAMP, the receptor number of a differentiated RA-ES-5 cell was increased about 80% and the Kd was also increased to 370 pM. Furthermore,more direct evidence supporting the expression of TGF-βtype Ⅰand type Ⅱ receptors in both ES-5 and RA-ES-5 cells has come from dot blot hybridization of cellular mRNA with cDNA probes for type Ⅰ and type Ⅱ recep-tors. Meanwhile, mRNA expression level of types Ⅰ and Ⅱreceptors in RA-ES-5 cells were higher than that in ES-5 cells. Down regulation of TGF-β receptors with a signifi-cant decrease in the rate of cell proliferation in both cells, was found by employing a pretreatment with neutralizing antibody to TGF-β1. The possible role of receptors for TGF-β in cen differentiation is discussed here.

Effects of salvianolic acid B on proliferation, neurite outgrowth and differentiation of neural stem cells derived from the cerebral cortex of embryonic mice

Salvianolic acid B is isolated from Salvia miltiorrhiza,the root of which is widely used as a traditional Chinese medicine to treat stroke.However,little is known about how salvianolic acid B influences growth characteristics of neural stem cells (NSCs).The purpose of the present study was to evaluate the effects of salvianolic acid B on proliferation,neurite outgrowth and differentiation of NSCs derived from the cerebral cortex of embryonic mice using MTT,flow cytometry,immunofluorescence and RT-PCR.It was found that 20 μg mL·1 and 40 μg mL·1 salvianolic acid B had similar effects on proliferation of NSCs,and a suitable concentration of salvianolic acid B increased the number of NSCs and their derivative neurospheres.The growth-promoting activity of salvianolic acid B was dependent on and associated with an accumulation in the G2/S-phase cell population.Salvianolic acid B also promoted the neurite outgrowth of NSCs and their differentiation into neurons.The mRNA for tau,GFAP and nestin were present in differentiating neurospheres induced by salvianolic acid B.However,high-level expression of tau mRNA and low-level expression of GFAP mRNA was detected in differentiated cells,in contrast to the control conditions.This collective evidence indicates that exogenous salvianolic acid B is capable of promoting proliferation of neurospheres and differentiation towards the neuronal lineage in vitro and may act in the proliferation of NSCs and may promote NSC differentiation into neuronal cells.

Embryoid bodies formation and differentiation from mouse embryonic stem cells in collagen/Matrigel scaffolds

Embryonic stem （ES） cells have the potential to develop into any type of tissue and are considered as a promising source of seeding cells for tissue engineering and transplantation therapy.The main catalyst for ES cells differentiation is the growth into embryoid bodies （EBs）,which are utilized widely as the trigger of in vitro differentiation.In this study,a novel method for generating EBs from mouse ES cells through culture in collagen/Matrigel scaffolds was successfully established.When single ES cells were seeded in three dimensional collagen/Matrigel scaffolds,they grew into aggregates gradually and formed simple EBs with circular structures.After 7 days＇ culture,they formed into cystic EBs that would eventually differentiate into the three embryonic germ layers.Evaluation of the EBs in terms of morphology and potential to differentiate indicated that they were typical in structure and could generate various cell types;they were also able to form into tissue-like structures.Moreover,with introduction of ascorbic acid,ES cells differentiated into cardiomyocytes efficiently and started contracting synchronously at day 19.The results demonstrated that collagen/Matrigel scaffolds supported EBs formation and their subsequent differentiation in a single three dimensional environment.

Generation of diverse neural cell types through direct conversion

A characteristic of neurological disorders is the loss of critical populations of cells that the body is unable to replace,thus there has been much interest in identifying methods of generating clinically relevant numbers of cells to replace those that have been damaged or lost.The process of neural direct conversion,in which cells of one lineage are converted into cells of a neural lineage without first inducing pluripotency,shows great potential,with evidence of the generation of a range of functional neural cell types both in vitro and in vivo,through viral and non-viral delivery of exogenous factors,as well as chemical induction methods.Induced neural cells have been proposed as an attractive alternative to neural cells derived from embryonic or induced pluripotent stem cells,with prospective roles in the investigation of neurological disorders,including neurodegenerative disease modelling,drug screening,and cellular replacement for regenerative medicine applications,however further investigations into improving the efficacy and safety of these methods need to be performed before neural direct conversion becomes a clinically viable option.In this review,we describe the generation of diverse neural cell types via direct conversion of somatic cells,with comparison against stem cell-based approaches,as well as discussion of their potential research and clinical applications.

Neural precursors derived from human embryonic stem cells

Human embryonic stem (hES) cells provide a promising supply of specific cell types for transplantation therapy. We presented here the method to induce differentiation of purified neural precursors from hES cells. hES cells (Line PKU-1 and Line PKU-2) were cultured in sus- pension in bacteriological Petri dishes, which differentiated into cystic embryoid bodies (EBs). The EBs were then cultured in N2 medium containing bFGF in poly-L-lysine-coated tissue culture dishes for two weeks. The central, small cells with 2―3 short processes of the spreading out- growth were isolated mechanically and replated. The resulting neurospheres were cultured in suspension for 10 days, then dissociated into single cell suspension with a Pasteur pipette and plated. Cells grew vigorously in an attached way and were passed every 4―5 days. Almost all the cells were proved nestin positive by immunostaining. Following withdrawal of bFGF, they differentiated into neurons expressing β-tubulin isotypeIII, GABA, serotonin and synaptophysin. Through induction of PDGF-AA, they differentiated into astrocytes expressing GFAP and oli- godendrocytes expressing O4. The results showed that hES cells can differentiate into typical neural precursors expressing the specific marker nestin and capable of generating all three cell types of the central nervous system (CNS) in vitro.

Generation of Tripotent Neural Progenitor Cells from Rat Embryonic Stem Cells

Rat is a valuable model for pharmacological and physiological studies. Germline-competent rat embryonic stem （rES） cell lines have been successfully established and the molecular networks maintaining the self-renewing, undifferentiated state of rES cells have also been well uncovered. However, little is known about the differentiation strategies and the underlying mechanisms of how these authentic rat pluripotent stem ceils give rise to specific cell types. The aim of this study is to investigate the neural differentiation capacity of rES cells. By means of a modified procedure based on previous publications - combination of mitogen-activated protein kinase （MAPK） and glycogen synthase kinase 3 （GSK3） inhibitors （two inhibitors, ＂2i＂） with feeder-conditioned medium, we successfully obtained high- quality rat embryoid bodies （rEBs） from rES cells and then differentiated them to tripotent neural progenitors. These rES cell-derived neural progenitor cells （rNPCs） were capable of self-renewing and giving rise to all three neural lineages, including astrocytes, oligo- dendrocytes, and neurons. Besides, these rES cell-derived neurons stained positive for y-aminobutyric acid （GABA） and tyrosine hydroxylase （TH）. In summary, we develop an experimental system for differentiating rES cells to tripotent neural progenitors, which may provide a powerful tool for pharmacological test and a valuable platform for studying the pathogenesis of many neurodegenerative disorders such as Parkinson＇s disease and the development of rat nervous system.

Differentiation of embryonic stem cells transfected by ibeB gene

We have previously identified an E. coli deter- minant, ibeB gene locus contributing to invasion of human brain microvascular endothelial cells. In the present study, we established embryonic stem (ES) cell lines overexpressing IbeB and found that exogenic ibeB gene could start-up expression of a neural stem cell specific marker, nestin, and give rise to polar changes. In analysis of IbeB location, it was found that GFP-IbeB fusion protein targeted at the ES cell nucleus. These data suggests that ibeB gene may play an important role in the regulation of nestin expression.

小鼠ES细胞神经分化的方法比较研究

采用类胚体法(EB)的EB分化4-/4+程序和单层分化法研究不同的实验方法对胚胎干细胞神经分化的影响。用4-/4+分化程序进行胚胎干细胞的神经分化时,饲养层细胞的存在对类胚体的形成无影响,在神经分化的13d,仍可观察到46C细胞的Sox1-GFP绿色荧光,此时的免疫染色结果显示,分化细胞中除了有Nestin阳性的神经干细胞及胶质纤维酸性蛋白(GFAP)阳性的神经胶质细胞外,以β-tubulin 阳性神经元细胞最为多见,这些神经元呈现出多种形态;用单层分化法进行胚胎干细胞(ES)细胞的神经分化至13d时,分化形成的神经细胞种类与类胚体法相同,但神经元的细长纤维形成了复杂的网状结构,提示两种分化方法获得的神经元处于不同发育阶段。研究结果表明,两种分化方法均能为ES细胞提供从神经分化的起始到继续分化所需的环境,EB分化法适合于大量地获取分化的细胞,而单层分化法可直观地研究分化过程的细胞变化。

BDE-209/BPA暴露对人胚胎干细胞系FY-hES-10早期神经分化中印记基因表达的影响

目的探讨十溴联苯醚(BDE-209)和双酚A(BPA)暴露对人胚胎干细胞系FY-hES-10体外早期神经分化中印记基因表达的影响。方法利用添加小分子抑制剂的方法将FY-hES-10细胞系进行神经贴壁诱导,并在培养基中添加低剂量的BDE-209或/和BPA,每24 h换液1次,连续暴露11 d。收集诱导分化第11天的细胞检测nestin阳性率以及印记基因SNRPN、KCNK9、UBE3A和PEG10的表达水平。结果 BDE-209、BPA单独或联合暴露组nestin的阳性率明显低于对照组(P<0. 05)。印记基因SNRPN、KCNK9、UBE3A在BDE-209、BPA单独或联合暴露组表达均明显低于对照组,PEG10在BDE-209 1 nmol/L和BDE-209 1 nmol/L+BPA 1 nmol/L组表达明显低于对照组,而在BPA 1 nmol/L组中表达与对照组无明显区别。结论低剂量BDE-209/BPA单独或联合暴露均有可能通过影响胚胎干细胞早期神经分化中印记基因表达从而产生神经发育毒性,BDE-209和BPA联合暴露可能加重神经发育毒性。

胚体培养对小鼠ES细胞定向神经分化的影响研究

为了研究胚胎干细胞（ES细胞）的定向诱导分化过程中胚体的形成对其后分化的影响，通过悬滴培养、悬浮培养及两者结合的方法得到2～4d的胚体（EBs），利用全反视黄酸（RA）对其处理4d后，进行免疫细胞化学和兴奋性功能的检测，观察比较了不同培养方式和不同培养时间下EBs分化出来的神经细胞所占的比例。结果表明，用单纯悬浮3d或悬滴3d转悬浮1d的培养方法得到的胚体其神经分化的比例较高，这对进一步阐明胚胎干细胞自身内部调控诱导分化的机制有一定的参考意义。

Nestin-GFP小鼠胚胎干细胞的建系及体外神经分化

【目的】建立Nestin-GFP转基因小鼠的胚胎干细胞(mESC)系,并观察其示踪ES细胞系的神经分化过程。【方法】将E3.5的Nestin-GFP小鼠囊胚接种于小鼠胚胎成纤维细胞上(MEF经γ射线照射失去增殖活性)。4～6d后将自囊胚长出的内细胞团(ICM)继续培养并传代扩增,检测所得细胞Oct-4、SSEA-1和AKP等胚胎干细胞特异性标志物的表达及在体内外向三胚层分化的能力;之后,诱导细胞向神经元样细胞及神经胶质样细胞分化,利用免疫荧光检测其标志性抗原。【结果】免疫组化可见Nestin-GFP小鼠胚胎干细胞表达未分化细胞特异性标志Oct-4、SSEA-1,AKP染色呈强阳性,并具有向体内外三胚层分化潜能;在体外诱导其向神经分化,第6d可见到明显的绿色荧光,并与免疫组化Nestin表达部位基本吻合。第12d及第16d分别可见神经元及神经胶质细胞特异性标志物表达,而此时Nestin的表达较前明显下降。【结论】成功建立了Nestin-GFP小鼠胚胎干细胞系,该细胞具有自我更新的特性及多向分化潜能,并可用于在体外更直观的监测神经分化的阶段性变化并由此进行调控。

Chemical approach to generating long-term self-renewing pMN progenitors from human embryonic stem cells

Spinal cord impairment involving motor neuron degeneration and demyelination can cause lifelong disabilities,but effective clinical interventions for restoring neurological functions have yet to be developed.In early spinal cord development,neural progenitors of the motor neuron(pMN)domain,defined by the expression of oligodendrocyte transcription factor 2(OLIG2),in the ventral spinal cord first generate motor neurons and then switch the fate to produce myelin-forming oligodendrocytes.Given their differentiation potential,pMN progenitors could be a valuable cell source for cell therapy in relevant neurological conditions such as spinal cord injury.However,fast generation and expansion of pMN progenitors in vitro while conserving their differentiation potential has so far been technically challenging.In this study,based on chemical screening,we have developed a new recipe for efficient induction of pMN progenitors from human embryonic stem cells.More importantly,these OLIG2+pMN progenitors can be stably maintained for multiple passages without losing their ability to produce spinal motor neurons and oligodendrocytes rapidly.Our results suggest that these self-renewing pMN progenitors could potentially be useful as a renewable source of cell transplants for spinal cord injury and demyelinating disorders.