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1.
Brain Res ; 1678: 397-406, 2018 Jan 01.
Article En | MEDLINE | ID: mdl-29155003

Many studies have demonstrated that combining nerve conduits with neural stem cells or growth factors can repair peripheral nerve injury in rodents. However, nerve damage does occur with longer gaps in human than in rodents, thus findings from rodent studies are difficult to translate to clinical practice. Minipigs have a longer gap that is more closely applicable to the challenge of human nerve grafting in extensive traumatic nerve damage. In this study, human amniotic fluid stem cells (AFSCs) and polylactate nerve conduits were used to repair sciatic nerve injury in minipigs. The AFSCs exhibited the properties of mesenchymal stem cells with a propensity toward neural stem cells. Measurements of compound muscle action potential implied that administration of conduits with AFSCs was beneficial in function recovery in the minipig model compared with conduits alone. The results of diffusion tensor magnetic resonance imaging (DTI) based fiber tractography assay in the minipig model suggest that combining AFSCs with conduits could expedite the repair of sciatic nerve injury. Further, MR-based DTI provides an effective and non-invasive method to visualize the sciatic nerve and to monitor the regeneration progress of injured nerve in a longitudinal study.


Amniotic Fluid/cytology , Sciatic Neuropathy/surgery , Stem Cell Transplantation/methods , Animals , Antigens, CD/metabolism , Cell Differentiation/drug effects , Disease Models, Animal , Evoked Potentials, Motor/drug effects , Evoked Potentials, Motor/physiology , Fibroblast Growth Factor 1/metabolism , Flow Cytometry , Humans , Intercellular Signaling Peptides and Proteins/pharmacology , Magnetic Resonance Imaging , Mesenchymal Stem Cells/physiology , Muscle, Skeletal/physiopathology , Nerve Regeneration , Nerve Tissue Proteins/metabolism , RNA, Messenger/metabolism , Sciatic Neuropathy/diagnostic imaging , Sciatic Neuropathy/pathology , Stem Cells , Swine , Swine, Miniature
2.
Mol Cell Neurosci ; 79: 1-11, 2017 03.
Article En | MEDLINE | ID: mdl-27865767

Regeneration of injured peripheral nerves is a slow, complicated process that could be improved by implantation of neural stem cells (NSCs) or nerve conduit. Implantation of NSCs along with conduits promotes the regeneration of damaged nerve, likely because (i) conduit supports and guides axonal growth from one nerve stump to the other, while preventing fibrous tissue ingrowth and retaining neurotrophic factors; and (ii) implanted NSCs differentiate into Schwann cells and maintain a growth factor enriched microenvironment, which promotes nerve regeneration. In this study, we identified IL12p80 (homodimer of IL12p40) in the cell extracts of implanted nerve conduit combined with NSCs by using protein antibody array and Western blotting. Levels of IL12p80 in these conduits are 1.6-fold higher than those in conduits without NSCs. In the sciatic nerve injury mouse model, implantation of NSCs combined with nerve conduit and IL12p80 improves motor recovery and increases the diameter up to 4.5-fold, at the medial site of the regenerated nerve. In vitro study further revealed that IL12p80 stimulates the Schwann cell differentiation of mouse NSCs through the phosphorylation of signal transducer and activator of transcription 3 (Stat3). These results suggest that IL12p80 can trigger Schwann cell differentiation of mouse NSCs through Stat3 phosphorylation and enhance the functional recovery and the diameter of regenerated nerves in a mouse sciatic nerve injury model.


Interleukin-12/metabolism , Nerve Regeneration , Neural Stem Cells/transplantation , Neurogenesis , Peripheral Nerve Injuries/therapy , Schwann Cells/cytology , Sciatic Nerve/physiology , Animals , Cells, Cultured , Mice , Neural Stem Cells/cytology , Neural Stem Cells/metabolism , STAT3 Transcription Factor/metabolism , Stem Cell Transplantation
3.
Exp Cell Res ; 344(2): 153-66, 2016 06 10.
Article En | MEDLINE | ID: mdl-27138904

UNLABELLED: Fibroblast growth factor 1 (FGF1) binds and activates FGF receptors, thereby regulating cell proliferation and neurogenesis. Human FGF1 gene 1B promoter (-540 to +31)-driven SV40 T antigen has been shown to result in tumorigenesis in the brains of transgenic mice. FGF1B promoter (-540 to +31)-driven green fluorescent protein (F1BGFP) has also been used in isolating neural stem cells (NSCs) with self-renewal and multipotency from developing and adult mouse brains. In this study, we provide six lines of evidence to demonstrate that FGF1/FGFR signaling is implicated in the expression of Aurora A (AurA) and the activation of its kinase domain (Thr288 phosphorylation) in the maintenance of glioblastoma (GBM) cells and NSCs. First, treatment of FGF1 increases AurA expression in human GBM cell lines. Second, using fluorescence-activated cell sorting, we observed that F1BGFP reporter facilitates the isolation of F1BGFP(+) GBM cells with higher expression levels of FGFR and AurA. Third, both FGFR inhibitor (SU5402) and AurA inhibitor (VX680) could down-regulate F1BGFP-dependent AurA activity. Fourth, inhibition of AurA activity by two different AurA inhibitors (VX680 and valproic acid) not only reduced neurosphere formation but also induced neuronal differentiation of F1BGFP(+) GBM cells. Fifth, flow cytometric analyses demonstrated that F1BGFP(+) GBM cells possessed different NSC cell surface markers. Finally, inhibition of AurA by VX680 reduced the neurosphere formation of different types of NSCs. Our results show that activation of AurA kinase through FGF1/FGFR signaling axis sustains the stem cell characteristics of GBM cells. IMPLICATIONS: This study identified a novel mechanism for the malignancy of GBM, which could be a potential therapeutic target for GBM.


Aurora Kinase A/metabolism , Fibroblast Growth Factor 1/metabolism , Glioblastoma/pathology , Neoplastic Stem Cells/enzymology , Neoplastic Stem Cells/pathology , Receptors, Fibroblast Growth Factor/metabolism , Signal Transduction , Animals , Aurora Kinase A/antagonists & inhibitors , Cell Differentiation/drug effects , Cell Line, Tumor , Cell Self Renewal/drug effects , Cell Separation , Embryonic Stem Cells/drug effects , Embryonic Stem Cells/metabolism , Enzyme Activation/drug effects , Fibroblast Growth Factor 1/genetics , Fibroblast Growth Factor 1/pharmacology , Genes, Reporter , Glioblastoma/enzymology , Green Fluorescent Proteins/metabolism , Humans , Mice , Multipotent Stem Cells/drug effects , Multipotent Stem Cells/pathology , Neoplastic Stem Cells/drug effects , Neural Stem Cells/drug effects , Neural Stem Cells/metabolism , Neurons/drug effects , Neurons/pathology , Piperazines/pharmacology , Promoter Regions, Genetic/genetics , Signal Transduction/drug effects , Spheroids, Cellular/drug effects , Spheroids, Cellular/metabolism
4.
Methods Mol Biol ; 1516: 289-297, 2016.
Article En | MEDLINE | ID: mdl-27044047

Neurosphere assay is a common and robust method for identification of neural stem/progenitor cells, but obtaining large numbers of live single cells from dissociated neurospheres is difficult using nonenzymatic methods. Here, we present an enzyme-free method for high-efficiency neurosphere dissociation into single cells using microfluidic device technology. This method allows single cell dissociation of DC115 and KT98 cells with high cell viabilities (80-85 %), single-cell yield (91-95 %), and recovery (75-93 %).


Cell Culture Techniques/methods , Microfluidic Analytical Techniques/methods , Microfluidics/methods , Neural Stem Cells/cytology , Animals , Cell Differentiation/genetics , Mice
6.
Stem Cells Dev ; 24(24): 2853-63, 2015 Dec 15.
Article En | MEDLINE | ID: mdl-26414172

Heart disease is the leading cause of human death in the 21st century. Heart transplantation is a promising way to treat this. Because donor resources are limited, cell-based therapy has been developed as an alternative. Therefore, genes that trigger cardiogenesis could have potential in the treatment of heart disease. Fibroblast growth factor 1 (FGF1) is reported to stimulate cardiomyocyte proliferation under conditions of myocardial infarction, but little is known about its function during cardiac differentiation. In this study, we established an in vitro cardiogenesis model through a reliable chemical induction protocol to determine whether FGF1 and its gene expression are involved in cardiogenesis. Oxytocin, not only a well-known hormone but also a cardiac differentiation inducer, was used in a mouse embryonic stem cell line, E14Tg2a, to achieve cardiac differentiation. After differentiation, beating cell clusters appeared and the expression of FGF1B mRNA was upregulated in the late differentiation stage (differentiation days 8-14). Interestingly, FGF1B expression patterns during cardiac differentiation were similar to those of a mature cardiomyocyte marker, troponin T2, cardiac. The blockage of FGF1-FGF receptor (FGFR) signaling reduced not only the appearance of beating cluster formation but also the expression levels of cardiomyocyte-associated genes. Moreover, by investigating FGF1 downstream signaling cascades, we observed that the efficiency of beating cluster formation was mainly regulated through the FGF1-FGFR-PKC signaling axis. Taken together, we provide evidence to support that FGF1 could regulate cardiogenesis primarily through the protein kinase C signaling, but not through the mitogen-activated protein kinase signaling, pathway.


Cell Differentiation , Embryonic Stem Cells/cytology , Fibroblast Growth Factor 1/metabolism , Myocytes, Cardiac/cytology , Promoter Regions, Genetic , Protein Kinase C/metabolism , Second Messenger Systems , Animals , Cell Line , Embryonic Stem Cells/drug effects , Embryonic Stem Cells/metabolism , Fibroblast Growth Factor 1/genetics , MAP Kinase Signaling System , Mice , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Oxytocin/pharmacology , Protein Kinase C/genetics , Receptors, Fibroblast Growth Factor/genetics , Receptors, Fibroblast Growth Factor/metabolism , Troponin T/genetics , Troponin T/metabolism
7.
Dev Neurobiol ; 75(3): 232-48, 2015 Mar.
Article En | MEDLINE | ID: mdl-25104610

FGF1 is involved in multiple biological functions and exhibits the importance in neuroprotective effects. Our previous studies indicated that, in human brain and retina, the FGF1B promoter controlled the expression of FGF1. However, the exact function and regulation of FGF1 in brain is still unclear. Here, we generated F1B-GFP transgenic mice that expressed the GFP reporter gene under the control of human FGF1B promoter (-540 to +31). Using the fresh brain sections of F1B-GFP transgenic mice, we found that the F1B-GFP cells expressed strong fluorescent signals in the ventricular system throughout the brain. The results of immunohistochemistry further showed that two distinct populations of F1B-GFP(+) cells existed in the brains of F1B-GFP transgenic mice. We demonstrated that one population of F1B-GFP(+) cells was ependymal cells, which distributed along the entire ventricles, and the second population of F1B-GFP(+) cells was neuronal cells that projected their long processes into multiple directions in specific areas of the brain. The double labeling of F1B-GFP(+) cells and tyrosine hydroxylase indicated that a subpopulation of F1B-GFP(+) -neuronal cells was dopaminergic neurons. Importantly, these F1B-GFP(+) /TH(+) cells were distributed in the main dopaminergic neuronal groups including hypothalamus, ventral tegmental area, and raphe nuclei. These results suggested that human FGF1B promoter was active in ependymal cells, neurons, and a portion of dopaminergic neurons. Thus, the F1B-GFP transgenic mice provide an animal model not only for studying FGF1 gene expression in vivo but also for understanding the role of FGF1 contribution in neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease.


Dopaminergic Neurons/metabolism , Ependyma/cytology , Fibroblast Growth Factor 1/genetics , Green Fluorescent Proteins/metabolism , Promoter Regions, Genetic , Receptor, Fibroblast Growth Factor, Type 1/genetics , Animals , Brain/cytology , Brain/metabolism , Cerebral Ventricles/cytology , Cerebral Ventricles/metabolism , Dopaminergic Neurons/cytology , Ependyma/metabolism , Fibroblast Growth Factor 1/metabolism , Gene Expression Regulation , Green Fluorescent Proteins/genetics , Humans , Mice , Mice, Transgenic , Receptor, Fibroblast Growth Factor, Type 1/metabolism , Tyrosine 3-Monooxygenase/metabolism
8.
Cell Transplant ; 24(5): 779-96, 2015.
Article En | MEDLINE | ID: mdl-24380568

Previous studies showed that transplantation of cultured neural stem/progenitor cells (NSPCs) could improve functional recovery for various neurological diseases. This study aims to develop a stem cell-based model for predictive toxicology of development in the neurological system after acrylamide exposure. Treatment of mouse (KT98/F1B-GFP) and human (U-1240 MG/F1B-GFP) NSPCs with 0.5 mM acrylamide resulted in the inhibition of neurosphere formation (definition of self-renewal ability in NSPCs), but not inhibition of cell proliferation. Apoptosis and differentiation of KT98 (a precursor of KT98/F1B-GFP) and KT98/F1B-GFP are not observed in acrylamide-treated neurospheres. Analysis of secondary neurosphere formation and differentiation of neurons and glia illustrated that acrylamide-treated KT98 and KT98/F1B-GFP neurospheres retain the NSPC properties, such as self-renewal and differentiation capacity. Correlation of acrylamide-inhibited neurosphere formation with cell-cell adhesion was observed in mouse NSPCs by live cell image analysis and the presence of acrylamide. Protein expression levels of cell adhesion molecules [neural cell adhesion molecule (NCAM) and N-cadherin] and extracellular signal-regulated kinases (ERK) in acrylamide-treated KT98/F1B-GFP and U-1240 MG/F1B-GFP neurospheres demonstrated that NCAM decreased and phospho-ERK (pERK) increased, whereas expression of N-cadherin remained unchanged. Analysis of AKT (protein kinase B, PKB)/ß-catenin pathway showed decrease in phospho-AKT (p-AKT) and cyclin D1 expression in acrylamide-treated neurospheres of KT98/F1B-GFP. Furthermore, PD98059, an ERK phosphorylation inhibitor, attenuated acrylamide-induced ERK phosphorylation, indicating that pERK contributed to the cell proliferation, but not in neurosphere formation in mouse NSPCs. Coimmunoprecipitation results of KT98/F1B-GFP cell lysates showed that the complex of NCAM and fibroblast growth factor receptor 1 (FGFR1) is present in the neurosphere, and the amount of this complex decreases after acrylamide treatment. Our results reveal that acrylamide inhibits neurosphere formation through the disruption of the neurosphere architecture in NSPCs. The downregulation of cell-cell adhesion resulted from decreasing the levels of NCAM as well as the formation of NCAM/FGFR complex.


Acrylamide/pharmacology , Neural Stem Cells/metabolism , Spheroids, Cellular/metabolism , Animals , Cell Adhesion/drug effects , Cell Culture Techniques , Cells, Cultured , Mice , Mice, Transgenic , Neural Stem Cells/cytology , Spheroids, Cellular/cytology
9.
Arch Toxicol ; 88(3): 769-80, 2014 Mar.
Article En | MEDLINE | ID: mdl-24318646

Acrylamide is a neurological and reproductive toxicant in humans and laboratory animals; however, the neuron developmental toxicity of acrylamide remains unclear. The aims of this study are to investigate the cytotoxicity and neurite outgrowth inhibition of acrylamide in nerve growth factor (NGF)- or fibroblast growth factor 1 (FGF1)-mediated neural development of PC12 cells. MTS assay showed that acrylamide treatment suppresses NGF- or FGF1-induced PC12 cell proliferation in a time- and dose-dependent manner. Quantification of neurite outgrowth demonstrated that 0.5 mM acrylamide treatment resulted in significant decrease in differentiation of NGF- or FGF1-stimulated PC12 cells. This decrease is accompanied with the reduced expression of growth-associated protein-43, a neuronal marker. Moreover, relative levels of pERK, pAKT, pSTAT3 and pCREB were increased within 5-10 min when PC12 cells were treated with NGF or FGF1. Acrylamide (0.5 mM) decreases the NGF-induced activation of AKT-CREB but not ERK-STAT3 within 20 min. Similarly, acrylamide (0.5 mM) decreases the FGF1-induced activation of AKT-CREB within 20 min. In contrast to the NGF treatment, the ERK-STAT3 activation that was induced by FGF1 was slightly reduced by 0.5 mM acrylamide. We further showed that PI3K inhibitor (LY294002), but not MEK inhibitor (U0126), could synergize with acrylamide (0.5 mM) to reduce the cell viability and neurite outgrowth in NGF- or FGF1-stimulated PC12 cells. Moreover, acrylamide (0.5 mM) increased reactive oxygen species (ROS) activities in NGF- or FGF1-stimulated PC12 cells. This increase was reversed by Trolox (an ROS scavenging agent) co-treatment. Together, our findings reveal that NGF- or FGF1-stimulation of the neuronal differentiation of PC12 cells is attenuated by acrylamide through the inhibition of PI3K-AKT-CREB signaling, along with the production of ROS.


Acrylamide/toxicity , Fibroblast Growth Factor 1/pharmacology , Nerve Growth Factor/pharmacology , PC12 Cells/drug effects , Animals , Butadienes/pharmacology , Cell Differentiation/drug effects , Chromones/pharmacology , Morpholines/pharmacology , Neurites/drug effects , Nitriles/pharmacology , PC12 Cells/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Phosphoinositide-3 Kinase Inhibitors , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-akt/metabolism , Rats , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects
10.
Anal Chem ; 85(24): 11920-8, 2013 Dec 17.
Article En | MEDLINE | ID: mdl-24228937

Obtaining single dissociated cells from neurospheres is difficult using nonenzymatic methods. In this paper we report the development of a microfluidic-chip-based approach that utilizes flow and microstructures to dissociate neurospheres. We show that this microfluidic-chip-based neurosphere-dissociation method can generate high yields of single cells from dissociated neurospheres of mouse KT98 and DC115 cell models (passage number, 3-8; diameter range, 40-250 µm): 90% and 95%, respectively. The microfluidic-chip-dissociated cells had high viabilities (80-85%) and the ability to regrow into neurospheres, demonstrating the applicability of this device to neurosphere assay applications. In addition, the dissociated cells retained their normal differentiation potentials, as shown by their capabilities to differentiate into three neural lineages (neurons, astroglia, and oligodendrocytes) when cultured in differentiation culture conditions. Since this microfluidic-chip-based method does not require the use of enzymatic reagents, the risk of contamination from exogenous substances could be reduced, making it an attractive tool for a wide range of applications where neurosphere dissociation is needed.


Microfluidic Analytical Techniques/methods , Neural Stem Cells/cytology , Single-Cell Analysis/methods , Animals , Cell Differentiation , Cell Line , Cell Survival , Equipment Design , Mice , Microfluidic Analytical Techniques/instrumentation , Single-Cell Analysis/instrumentation
11.
J Neurochem ; 126(1): 4-18, 2013 Jul.
Article En | MEDLINE | ID: mdl-23647222

Valproic acid (VPA) is the primary mood-stabilizing drug to exert neuroprotective effects and to treat bipolar disorder in clinic. Fibroblast growth factor 1 (FGF1) has been shown to regulate cell proliferation, cell division, and neurogenesis. Human FGF1 gene 1B promoter (-540 to +31)-driven green fluorescence (F1BGFP) has been shown to recapitulate endogenous FGF1 gene expression and facilitates the isolation of neural stem/progenitor cells (NSPCs) from developing and adult mouse brains. In this study, we provide several lines of evidence to demonstrate the underlying mechanisms of VPA in activating FGF-1B promoter activity: (i) VPA significantly increased the FGF-1B mRNA expression and the percentage of F1BGFP(+) cells; (ii) the increase of F1BGFP expression by VPA involves changes of regulatory factor X (RFX) 1-3 transcriptional complexes and the increase of histone H3 acetylation on the 18-bp cis-element of FGF-1B promoter; (iii) treatments of other histone deacetylases (HDAC) inhibitors, sodium butyrate and trichostatin A, significantly increased the expression levels of FGF-1B, RFX2, and RFX3 transcripts; (iv) treatments of glycogen synthase kinase 3 (GSK-3) inhibitor, lithium, or GSK-3 siRNAs also significantly activated FGF-1B promoter; (v) VPA specifically enhanced neuronal differentiation in F1BGFP(+) embryonic stem cells and NSPCs rather than GFP(-) cells. This study suggested, for the first time, that VPA activates human FGF1 gene promoter through inhibiting HDAC and GSK-3 activities.


Antimanic Agents/pharmacology , Fibroblast Growth Factor 1/drug effects , Fibroblast Growth Factor 1/genetics , Glycogen Synthase Kinase 3/antagonists & inhibitors , Histone Deacetylase Inhibitors , Histone Deacetylases/metabolism , Valproic Acid/pharmacology , Animals , Blotting, Western , Cell Differentiation/drug effects , Cell Line, Tumor , Chromatin Immunoprecipitation , Electrophoretic Mobility Shift Assay , Embryonic Stem Cells/drug effects , Flow Cytometry , Humans , Immunohistochemistry , Lithium Chloride/pharmacology , Mice , Neural Stem Cells/drug effects , Polymerase Chain Reaction , Promoter Regions, Genetic/genetics , RNA, Small Interfering/pharmacology , Transcriptional Activation/drug effects
12.
PLoS One ; 7(12): e52556, 2012.
Article En | MEDLINE | ID: mdl-23272250

POU5F1 is essential for maintaining pluripotency in embryonic stem cells (ESCs). It has been reported that the constitutive activation of POU5F1 is sustained by the core transcriptional regulatory circuitry in ESCs; however, the means by which POU5F1 is epigenetically regulated remains enigmatic. In this study a fluorescence-based reporter system was used to monitor the interplay of 5 reprogramming-associated TFs and 17 chromatin regulators in the transcription of POU5F1. We show the existence of a stoichiometric effect for SOX2, POU5F1, NANOG, MYC and KLF4, in regulating POU5F1 transcription. Chromatin regulators EP300, KDM5A, KDM6A and KDM6B cooperate with KLF4 in promoting the transcription of POU5F1. Moreover, inhibiting HDAC activities induced the expression of Pou5f1 in mouse neural stem cells (NSCs) in a spatial- and temporal- dependent manner. Quantitative chromatin immunoprecipitation-PCR (ChIP-qPCR) shows that treatment with valproic acid (VPA) increases the recruitment of Kdm5a and Kdm6a to proximal promoter (PP) and proximal enhancer (PE) of Pou5f1 whereas enrichment of Ep300 and Kdm6b was seen in PP but not PE of Pou5f1 promoter. These findings reveal the interplay between the chromatin regulators and histone modifications in the expression of POU5F1.


E1A-Associated p300 Protein/metabolism , Histone Demethylases/metabolism , Jumonji Domain-Containing Histone Demethylases/metabolism , Kruppel-Like Transcription Factors/metabolism , Nuclear Proteins/metabolism , Octamer Transcription Factor-3/genetics , Retinoblastoma-Binding Protein 2/metabolism , Transcriptional Activation , Animals , Cell Line , Chromatin/metabolism , Gene Expression Regulation/drug effects , Histone Deacetylase Inhibitors/pharmacology , Homeodomain Proteins/metabolism , Humans , Kruppel-Like Factor 4 , Mice , Nanog Homeobox Protein , Neural Stem Cells/metabolism , Protein Binding , Proto-Oncogene Proteins c-myc/metabolism , Regulatory Sequences, Nucleic Acid , Transcriptional Activation/drug effects
13.
Biomaterials ; 31(21): 5575-87, 2010 Jul.
Article En | MEDLINE | ID: mdl-20427083

The interaction of ultra-nanocrystalline diamond (UNCD) with neural stem cells (NSCs) has been studied in order to evaluate its potential as a biomaterial. Hydrogen-terminated UNCD (H-UNCD) films were compared with standard grade polystyrene in terms of their impact on the differentiation of NSCs. When NSCs were cultured on these substrates in medium supplemented with low concentration of serum and without any differentiating factors, H-UNCD films spontaneously induced neuronal differentiation on NSCs. By direct suppression of mitogen-activated protein kinase/extracellular signaling-regulated kinase1/2 (MAPK/Erk1/2) signaling pathway in NSCs using U0126, known to inhibit the activation of Erk1/2, we demonstrated that the enhancement of Erk1/2 pathway is one of the effects of H-UNCD-induced NSCs differentiation. Moreover, functional-blocking antibody directed against integrin beta1 subunit inhibited neuronal differentiation on H-UNCD films. This result demonstrated the involvement of integrin beta1 in H-UNCD-mediated neuronal differentiation. Mechanistic studies revealed the cell adhesion to H-UNCD films associated with focal adhesion kinase (Fak) and initiated MAPK/Erk1/2 signaling. Our study demonstrated that H-UNCD films-mediated NSCs differentiation involves fibronectin-integrin beta1 and Fak-MAPK/Erk signaling pathways in the absence of differentiation factors. These observations raise the potential for the use of UNCD as a biomaterial for central nervous system transplantation and tissue engineering.


Cell Differentiation/physiology , Diamond/chemistry , Nanoparticles/chemistry , Neurons/physiology , Stem Cells/physiology , Animals , Biomarkers/metabolism , Butadienes/metabolism , Cell Adhesion , Cells, Cultured , Coated Materials, Biocompatible/chemistry , Enzyme Inhibitors/metabolism , Extracellular Signal-Regulated MAP Kinases/metabolism , Fibronectins/metabolism , Focal Adhesion Kinase 1/metabolism , Integrin beta1/metabolism , Materials Testing , Mice , Neurons/cytology , Nitriles/metabolism , Signal Transduction/physiology , Stem Cells/cytology , Surface Properties
14.
Mol Cell Neurosci ; 41(3): 348-63, 2009 Jul.
Article En | MEDLINE | ID: mdl-19409495

Fibroblast growth factor 1 (FGF1) and FGF2 have been shown to maintain the proliferation, self-renewal and multipotent capacities of neural stem/progenitor cells (NSPCs) in vitro. FGF1 is unique for binding to all known FGF receptors. In this study, we investigated if exogenous EGF and FGF1 could be used in the isolation of NSPCs from embryonic mouse brains. We demonstrated that EGF/FGF1-responsive cells exhibited lower proliferation rate and neurosphere formation efficiency than EGF/FGF2-responsive NSPCs. However, EGF/FGF1-responsive mouse brain cells exhibited better neural differentiation capacities than EGF/FGF2-responsive NSPCs at E11.5. Using F1BGFP reporter, we further demonstrated that F1BGFP+ cells showed similar multipotent capacities to CD133+ NSPCs, and could be induced more efficiently toward neuronal differentiation. Our results suggested that EGF/FGF1-responsive cells from E11.5 mouse brains could self-renew and have better multipotency than EGF/FGF2-responsive NSPCs. Further, CD133+ and F1BGFP+ NSPCs may also represent different subsets of NSPCs during neural development and adult neurogenesis.


Adult Stem Cells/metabolism , Brain/cytology , Embryonic Stem Cells/metabolism , Epidermal Growth Factor/metabolism , Fibroblast Growth Factor 1/metabolism , Promoter Regions, Genetic , Receptor, Fibroblast Growth Factor, Type 1/metabolism , Adult Stem Cells/cytology , Animals , Brain/embryology , Brain/metabolism , Cell Differentiation , Cell Separation/methods , Embryonic Stem Cells/cytology , Fibroblast Growth Factor 2/metabolism , Green Fluorescent Proteins , Humans , Mice , Neurons/cytology , Neurons/metabolism , Receptor, Fibroblast Growth Factor, Type 1/genetics , Recombinant Fusion Proteins/metabolism , Regeneration
15.
Biomaterials ; 30(20): 3428-35, 2009 Jul.
Article En | MEDLINE | ID: mdl-19406465

The interaction of ultra-nanocrystalline diamond (UNCD) with neural stem cells (NSCs) has been studied along with its surface modification in order to improve its function as a biomaterial. Hydrogen- and oxygen-terminated UNCD films were compared with standard grade polystyrene in terms of their impact on the growth, expansion and differentiation of NSCs. When NSCs were cultured on these substrates in low serum and without any differentiating factors, hydrogen-terminated UNCD films spontaneously induced cell proliferation and neuronal differentiation. Oxygen-terminated UNCD films were also shown to further improve neural differentiation, with a preference to differentiate into oligodendrocytes. Hence, controlling the surface properties of UNCD could manipulate the differentiation of NSCs for different biomedical applications. These observations raise the potential for the use of UNCD as a biomaterial for central nervous system transplantation and tissue engineering.


Cell Culture Techniques/instrumentation , Cell Differentiation/physiology , Cell Proliferation , Diamond/chemistry , Neurons/physiology , Stem Cells/physiology , Animals , Biocompatible Materials/chemistry , Biocompatible Materials/metabolism , Cell Shape , Cells, Cultured , Humans , Materials Testing , Mice , Neurons/cytology , Polystyrenes/chemistry , Stem Cells/cytology , Surface Properties , Tubulin/metabolism
16.
Dev Dyn ; 238(2): 302-14, 2009 Feb.
Article En | MEDLINE | ID: mdl-18855895

Fibroblast growth factor 1 (FGF1) has been shown to maintain proliferation and self-renewal capacities of neural stem/progenitor cells (NSPCs) in vitro. We have previously identified FGF1B as the major transcript of FGF1 gene expressed exclusively in brain areas that are known to be abundant for NSPCs in vivo. The 540-bp (-540 to +31) sequence upstream of the 1B transcription start site (F1B) is sufficient to drive the expression of a heterologous luciferase reporter in cultured cells. In this study, we report a direct genetic and functional approach to isolate F1B(+) NSPCs using green fluorescent protein (GFP) reporter gene under the control of human F1B promoter. The F1B-GFP reporter could facilitate the isolation of NSPCs with self-renewal and multipotent capacities from human glioblastoma tissues, developing or adult mouse brains by fluorescence-activated cell sorting. Future work elucidating the mechanisms that control FGF1B expression will help to identify new NSPC-related genes.


Brain/cytology , Fibroblast Growth Factor 1/metabolism , Multipotent Stem Cells/cytology , Neurons/cytology , Stem Cells/cytology , Animals , Base Sequence , Brain/embryology , Brain/growth & development , Brain/metabolism , Cell Differentiation , Cell Line, Tumor , Fibroblast Growth Factor 1/genetics , Flow Cytometry , Gene Expression Regulation , Genes, Reporter , Glioblastoma/pathology , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Humans , Mice , Molecular Sequence Data , Promoter Regions, Genetic
17.
Cell Transplant ; 16(2): 133-50, 2007.
Article En | MEDLINE | ID: mdl-17474295

Neural stem cells (NSCs) have been proposed as a promising cellular source for the treatment of diseases in nervous systems. NSCs can self-renew and generate major cell types of the mammalian central nervous system throughout adulthood. NSCs exist not only in the embryo, but also in the adult brain neurogenic region: the subventricular zone (SVZ) of the lateral ventricle. Embryonic stem (ES) cells acquire NSC identity with a default mechanism. Under the regulations of leukemia inhibitory factor (LIF) and fibroblast growth factors, the NSCs then become neural progenitors. Neurotrophic and differentiation factors that regulate gene expression for controlling neural cell fate and function determine the differentiation of neural progenitors in the developing mammalian brain. For clinical application of NSCs in neurodegenerative disorders and damaged neurons, there are several critical problems that remain to be resolved: 1) how to obtain enough NSCs from reliable sources for autologous transplantation; 2) how to regulate neural plasticity of different adult stem cells; 3) how to control differentiation of NSCs in the adult nervous system. In order to understand the mechanisms that control NSC differentiation and behavior, we review the ontogeny of NSCs and other stem cell plasticity of neuronal differentiation. The role of NSCs and their regulation by neurotrophic factors in CNS development are also reviewed.


Nerve Growth Factors/metabolism , Neurons/cytology , Stem Cells/cytology , Animals , Brain/cytology , Humans , Neuronal Plasticity
18.
Stem Cells ; 24(3): 679-85, 2006 Mar.
Article En | MEDLINE | ID: mdl-16179428

Bone marrow and umbilical cord blood are reported to be the main sources of mesenchymal stem cells (MSCs), which have been proposed for many clinical applications. This study evaluated and quantitated the differentiation potential of bone marrow-derived MSCs (bmMSCs) and cord blood-derived MSCs (cbMSCs) by in vitro induction. Results indicated that cbMSCs had a significantly stronger osteogenic potential but lower capacity for adipogenic differentiation than bmMSCs. Leptin, an important regulator of mesenchymal differentiation, has a significantly stronger effect of promoting osteogenesis and inhibiting adipogenesis in bmMSCs than in cbMSCs. Moreover, Cbfa1 mRNA expression in bmMSCs and cbMSCs was affected to different degrees by leptin during osteogenesis. In contrast, leptin reduced PPARgamma2 mRNA expression to the same level during adipogenesis in both types of MSCs. These results demonstrate the disparate capacities of MSCs from bone marrow and cord blood and suggest that they be used differently in experimental and therapeutic studies. In addition, the disparate differentiation tendencies of MSCs from different sources should be considered in further applications.


Bone Marrow Cells/physiology , Cell Differentiation/physiology , Fetal Blood/physiology , Mesenchymal Stem Cells/physiology , Adipogenesis/drug effects , Adipogenesis/physiology , Bone Marrow Cells/cytology , Cell Differentiation/drug effects , Cells, Cultured , Core Binding Factor Alpha 1 Subunit/biosynthesis , Fetal Blood/cytology , Gene Expression Regulation/drug effects , Gene Expression Regulation/physiology , Humans , Leptin/metabolism , Leptin/pharmacology , Mesenchymal Stem Cells/cytology , Osteogenesis/drug effects , Osteogenesis/physiology , PPAR gamma/biosynthesis
19.
Stem Cells ; 23(7): 1012-20, 2005 Aug.
Article En | MEDLINE | ID: mdl-15941858

Recent studies have shown that adult tissues contain stem/ progenitor cells capable of not only generating mature cells of their tissue of origin but also transdifferentiating themselves into other tissue cells. Murine skin-derived precursor cells, for example, have been described as unique, nonmesenchymal-like stem cells capable of mesodermal and ectodermal neurogenic differentiation. Human-derived skin precursors are less well characterized. In this study, the isolation and characterization of adherent, mesenchymal stem cell-like cells from human scalp tissue (hSCPs) are described. hSCPs initially isolated by both medium-selection (ms-hSCPs) and single-cell (c-hSCPs) methods were cultured in medium containing epidermal growth factor and fibroblast growth factor-beta. Cultured ms-hSCPs and c-hSCPs demonstrated a consistent growth rate, continuously replicated in cell culture, and displayed a stable phenotype indistinguishable from each other. Both hSCPs expressed surface antigen profile (CDw90, SH2, SH4, CD105, CD166, CD44, CD49d-e, and HLA class I) similar to that of bone marrow mesenchymal stem cells (BM-MSCs). The growth kinetics, surface epitopes, and differentiation potential of c-hSCP cells were characterized and compared with BM-MSCs. In addition to differentiation along the osteogenic, chondrogenic, and adipogenic lineages, hSCPs can effectively differentiate into neuronal precursors evident by neurogenic gene expression of glial fibrillary acid protein, NCAM, neuron filament-M, and microtubule-associated protein 2 transcripts. Therefore, hSCPs may potentially be a better alternative of BM-MSCs for neural repairing, in addition to their other mesenchymal regenerative capacity. Our study suggests that hSCPs may provide an alternative adult stem cell resource that may be useful for regenerative tissue repair and autotransplantations.


Gene Expression Regulation , Mesenchymal Stem Cells/cytology , Neurons/metabolism , Scalp/metabolism , Adipocytes/metabolism , Adult , Animals , Bone Marrow Cells/cytology , Calcium/metabolism , Cell Culture Techniques/methods , Cell Differentiation , Cell Lineage , Cell Membrane/metabolism , Cells, Cultured , Chondrocytes/metabolism , Culture Media , Cytokines/metabolism , Fibroblast Growth Factors/metabolism , Flow Cytometry , Humans , Mice , Middle Aged , Osteocytes/metabolism , Phenotype , Reverse Transcriptase Polymerase Chain Reaction , Scalp/cytology , Skin/metabolism , Time Factors , Wound Healing
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