Id (Inhibitor of Differentiation) proteins belong to a family of transcriptional modulators that are characterized by a helix loop helix (HLH) region but lack the basic amino acid domain. Id proteins are known to interact with basic helix-loop-helix (bHLH) transcription factors and function as their negative regulators. The negative role of Id proteins has been well demonstrated in muscle development and some in neuronal cells. In this study, we investigated the effect of Id on the function of BETA2/NeuroD, a bHLH transcription factor responsible for neuron and endocrine cell specific gene expression. cDNAs of several Id isoforms were isolated by yeast two-hybrid system using the bHLH domain of E47, a ubiquitous bHLH partner as a bait. Id proteins expressed in COS M6 cells, were found in both cytosolic and nuclear fractions. Electrophoretic mobility shift assay showed that coexpression of Id2 proteins inhibited BETA2/ NeuroD binding to its target sequence, E-box. Id2 inhibited E-box mediated gene expression in a dose dependent manner in BETA2/NeuroD expressing HIT cells. Id coexpressed with BETA2/NeuroD in HeLa cells, inhibited the stimulatory activity of BETA2/NeuroD. These results suggest that Id proteins may negatively regulate tissue specific gene expression induced by BETA2/NeuroD in neuroendocrine cells and the inhibitory role of Id proteins during differentiation may be conserved in various tissues.
Amino Acid Sequence ; Animals ; Base Sequence ; Binding Sites ; Cells, Cultured ; DNA-Binding Proteins/genetics/*metabolism ; E-Box Elements ; Gene Expression Regulation/physiology ; Helix-Loop-Helix Motifs ; Human ; Islets of Langerhans/cytology/metabolism ; Mice ; Molecular Sequence Data ; Nerve Tissue Proteins/genetics/*metabolism ; Neurons/cytology/metabolism ; Organ Specificity ; Transcription Factors/genetics/*metabolism ; Two-Hybrid System Techniques

We correct a typo in the title.

Reelin, an extracellular glycoprotein has an important role in the proper migration and positioning of neurons during brain development. Lack of reelin causes not only disorganized lamination of the cerebral and cerebellar cortex but also malpositioning of mesencephalic dopaminergic (mDA) neurons. However, the accurate role of reelin in the migration and positioning of mDA neurons is not fully elucidated. In this study, reelin-deficient reeler mice exhibited a significant loss of mDA neurons in the substantia nigra pars compacta (SNc) and a severe alteration of cell distribution in the retrorubal field (RRF). This abnormality was also found in Dab1-deficinet, yotari mice. Stereological analysis revealed that total number of mDA neurons was not changed compared to wild type, suggesting that the loss of mDA neurons in reeler may not be due to the neurogenesis of mDA neurons. We also found that formation of PSA-NCAM-positive tangential nerve fibers rather than radial glial fibers was greatly reduced in the early developmental stage (E14.5) of reeler. These findings provide direct evidence that the alteration in distribution pattern of mDA neurons in the reeler mesencephalon mainly results from the defect of the lateral migration using tangential fibers as a scaffold.
Animals ; Brain ; Cerebellar Cortex ; Dopaminergic Neurons ; Glycoproteins ; Mesencephalon ; Mice ; Mice, Neurologic Mutants ; Nerve Fibers ; Neurogenesis ; Neurons ; Substantia Nigra

Neural stem cells are multipotent stem cells that can differentiate into neurons and glial cells. Neural stem cells are found in not only developing nervous system but some restricted regions in adult brain. Here, we presented an effective method that allows a long-term preservation of neural stem cells without losing multipotency. First, we isolated neural stem cells from the developing forebrain of nestin-EGFP transgenic mice carrying green fluorescence protein (GFP) driven by nestin promoter and enhancer. Primary neurospheres isolated from these mice highly expressed GFP. The expression of GFP in neurospheres was sustained for several passages. In order to investigate the effect of freezing on the stem cell properties, we cryopreserved the primary neurospheres for 2 wks in liquid nitrogen. GFP expression pattern as well as differentiation potential of the secondary neurosphere formed after cryopreservation were not that different from those of the primary neurosphere formed before cryopreservation. When the same cryopreservation method was applied to neural stem cells isolated from human fetal brain (gestation 13 ~15 wks), the expression of nestin, a stem cell marker, and differentiation patterns were not changed after cryopreservation. We also performed isolation of neural stem cells from long-term cryopreserved human fetal brain tissues. The neurospheres were successfully formed and showed similar differention properties with neurospheres isolated from fresh brain tissue. In addition, we demonstrated multipotentiality of neural stem cells was not changed with the duration of cryopreservation of brain tissue, suggesting the self renewality and multipotentiality of neural stem cells were not affected by long-term cryopreservation, The present results provide an useful information for the development of stem cell expansion which is essential factor in clinical application of stem cells.
Adult ; Animals ; Brain ; Cryopreservation* ; Fluorescence ; Freezing ; Humans ; Mice ; Mice, Transgenic ; Multipotent Stem Cells ; Nervous System ; Nestin ; Neural Stem Cells* ; Neuroglia ; Neurons ; Nitrogen ; Prosencephalon ; Stem Cells

Human mesenchymal stem cells (hMSCs) are multipotent stem cells that can differentiate into several mesenchymal lineage cells. In this study, we established an efficient method for gene delivery into these cells. Non-viral transfection reagents that were commercially available yielded 5% efficiency. In contrast, a retroviral vector yielded more than 46% transduction, which was further increased to 90% by repetitive infection. Retroviral transduction did not alter the multipotency of hMSCs. Thus, the cells retained the potential to differentiate into adipogenic, chondrogenic, or osteogenic lineages. The conditions established in this study will contribute to development of trans-differentiation methods of hMSCs into non-mesodermal lineage cells and thereby facilitate their possible use as vehicles for autologous transplantation in both cell and gene therapy for various diseases.
Autografts ; Genetic Therapy ; Humans* ; Indicators and Reagents ; Mesenchymal Stromal Cells* ; Multipotent Stem Cells ; Retroviridae ; Transfection ; Transplantation, Autologous ; Zidovudine*

Human mesenchymal stem cells (hMSCs) are multipotent stem cells that can differentiate into several mesenchymal lineage cells. In this study, we established conditions that allowed a long term expansion of hMSCs. To search for the optimum culture condition, growth rates of hMSCs were measured in the presence of several growth factors. Hepatic growth factor (HGF) and leukemia inhibitory factor (LIF) did not facilitate proliferation of hMSCs. In contrast, basic fibroblast growth factor (bFGF) effectively promoted growth of the cells in vitro by 3 fold. The growth stimulatory effect of bFGF was dependent on the concentration. The adipogenic potential was dramatically decreased in hMSCs isolated from an aged donor whereas osteogenic potential was minimally decreased. Addition of bFGF resumed the adipogenic and osteogenic differentiation potential. Thus, the cells that expanded in the presence of bFGF retained the potential to differentiate into adipogenic, chondrogenic, or osteogenic lineage cells. MSCs could be expanded for at least 8 passages with bFGF and the resulting cells retained the normal karyotype. The cells were positive for CD9, CD13, CD15, CD90, CD137, and CD140b; but negative for CD14, CD34, and CD45. Importantly, the cells were found to express a neural stem cell marker, nestin, and a neuronal marker, beta-tubulin III. The results suggest that bFGF promote proliferation while maintaining multi-lineage differentiation potency of hMSCs. Finally, we suggest that it is critical to identify novel markers other than nestin or beta-tubulin III to monitor acquisition of neuronal phenotypes by hMSCs.
Fibroblast Growth Factor 2* ; Humans* ; Intercellular Signaling Peptides and Proteins ; Karyotype ; Leukemia Inhibitory Factor ; Mesenchymal Stromal Cells* ; Multipotent Stem Cells ; Nestin ; Neural Stem Cells ; Neurons ; Phenotype ; Tissue Donors ; Tubulin

NeuroD/BETA2, a basic helix-loop-helix transcription factor, has been known to play a role in terminal differentia-tion during neurogenesis. To gain further insight into the function of NeuroD/BETA2 in the nervous system devel-opment, we examined the expression pattern of NeuroD/BETA2 during embryonic and postnatal development by in situ hybridization. Dynamic changes of NeuroD/BETA2 expression were observed in the developing nervous system. Gene expression of the NeuroD/BETA2 in developing cerebellum and hippocampus increased during the embryonic stages and persisted throughout postnatal development and remained at a stable level in the adult brain. NeuroD/ BETA2 expression was detected in postmitotic cells in the subventricular zone of the cerebrum during embryogenesis. This observation confirms that NeuroD/BETA2 may have a role in terminal differentiation during neurogenesis.
Adult ; Animals ; Brain ; Central Nervous System* ; Cerebellum ; Cerebrum ; Embryonic Development ; Female ; Gene Expression* ; Hippocampus ; Humans ; In Situ Hybridization ; Mice* ; Nervous System ; Neurogenesis ; Pregnancy ; Transcription Factors

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+ (30micrometer) or Cs+ (3micrometer). 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.
4-Aminopyridine ; Action Potentials ; Humans ; Membranes ; Neural Stem Cells ; Neurons ; Tetraethylammonium ; Tetrodotoxin

Bone marrow-derived mesenchymal stromal cells (MSCs) have been reported to be beneficial for the treatment of liver fibrosis. Here, we investigated the use of genetically engineered MSCs that overexpress hepatocyte growth factor (HGF) as a means to improve their therapeutic effect in liver fibrosis. Liver fibrosis was induced by intraperitoneal injection of dimethylnitrosamine. HGF-secreting MSCs (MSCs/HGF) were prepared by transducing MSCs with an adenovirus carrying HGF-encoding cDNA. MSCs or MSCs/HGF were injected directly into the spleen of fibrotic rats. Tissue fibrosis was assessed by histological analysis 12 days after stem cell injection. Although treatment with MSCs reduced fibrosis, treatment with MSCs/HGF produced a more significant reduction and was associated with elevated HGF levels in the portal vein. Collagen levels in the liver extract were decreased after MSC/HGF therapy, suggesting recovery from fibrosis. Furthermore, liver function was improved in animals receiving MSCs/HGF, indicating that MSC/HGF therapy resulted not only in reduction of liver fibrosis but also in improvement of hepatocyte function. Assessment of cell and biochemical parameters revealed that mRNA levels of the fibrogenic cytokines PDGF-bb and TGF-beta1 were significantly decreased after MSC/HGF therapy. Subsequent to the decrease in collagen, expression of matrix metalloprotease-9 (MMP-9), MMP-13, MMP-14 and urokinase-type plasminogen activator was augmented following MSC/HGF, whereas tissue inhibitor of metalloprotease-1 (TIMP-1) expression was reduced. In conclusion, therapy with MSCs/HGF resulted in an improved therapeutic effect compared with MSCs alone, probably because of the anti-fibrotic activity of HGF. Thus, MSC/HGF represents a promising approach toward a cell therapy for liver fibrosis.
Animals ; Cell Engineering ; Cells, Cultured ; *Genetic Engineering ; Hepatocyte Growth Factor/analysis/*genetics ; Humans ; Liver/metabolism/pathology ; Liver Cirrhosis/pathology/*therapy ; Male ; *Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells/*metabolism ; Rats ; Rats, Sprague-Dawley ; *Up-Regulation

Human mesenchymal stem cells (MSCs) have emerged as attractive cellular vehicles to deliver therapeutic genes for ex-vivo therapy of diverse diseases; this is, in part, because they have the capability to migrate into tumor or lesion sites. Previously, we showed that MSCs could be utilized to deliver a bacterial cytosine deaminase (CD) suicide gene to brain tumors. Here we assessed whether transduction with a retroviral vector encoding CD gene altered the stem cell property of MSCs. MSCs were transduced at passage 1 and cultivated up to passage 11. We found that proliferation and differentiation potentials, chromosomal stability and surface antigenicity of MSCs were not altered by retroviral transduction. The results indicate that retroviral vectors can be safely utilized for delivery of suicide genes to MSCs for ex-vivo therapy. We also found that a single retroviral transduction was sufficient for sustainable expression up to passage 10. The persistent expression of the transduced gene indicates that transduced MSCs provide a tractable and manageable approach for potential use in allogeneic transplantation.
Adolescent ; Animals ; Cell Death/drug effects ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Cell Transformation, Neoplastic/drug effects/pathology ; Child ; Cytosine Deaminase/*genetics/therapeutic use ; Fluorouracil/pharmacology ; Genetic Therapy ; Genomic Instability/drug effects ; Humans ; Karyotype ; Mesenchymal Stromal Cells/*cytology/drug effects/metabolism ; Mice ; Multipotent Stem Cells/cytology/drug effects/metabolism ; Neoplasms/therapy ; Retroviridae/*metabolism ; Time Factors ; *Transduction, Genetic