Showing papers on "Neurosphere published in 1994"

Mammalian neural crest stem cells

Abstract: The invention includes methods for the isolation and clonal propagation of mammalian neural crest stem cells and isolated cellular compositions comprising the same. The methods employ a novel separation and culturing regimen and bioassays for establishing the generation of neural crest stem cell derivatives. These methods result in the production of non-transformed neural crest stem cells and their progeny. The invention demonstrates, at the clonal level, the self regeneration and asymmetrical division of mammalian neural crest stem cells for the first time in feeder cell-independent cultures. Lineage restriction is demonstrated within a developing clone and is shown to be sensitive to the local environment. Neural crest stem cells cultured on a mixed substrate of poly-D-lysine and fibronectin generate PNS neurons and glia, but on fibronectin alone the stem cells generate PNS glia but not neurons. The neurogenic potential of the stem cells, while not expressed, is maintained over time on fibronectin. The invention further includes transplantation assays which allow for the identification of mammalian neural crest stem cells from various tissues. It also includes methods for transplanting mammalian neural crest stem cells and/or neural or glial progenitors into mammals.

Perpetuation of stem cells in the eye

Abstract: In adult tissues, cell numbers are maintained through a subpopulation of cell termed stem cells, characterised in part by a high capacity of self-renewal, slow cell cycle, and resistance towards differentiation. Stem cells are capable of asymmetric division and able to maintain their position in a particular microenvironment or niche. In the cornea, epithelial stem cells are believed to reside in the basal cell layer of the limbal epithelium. We consider the question of how stem cells are perpetuated in the limbus without entering the pathway of terminal differentiation. This perpetuation could presumably be the result of extrinsic properties of the limbal zone creating a 'stem cell niche', or of intrinsic properties of the cells. For example, limbal basal cells contain four- to fivefold higher levels of epidermal growth factor receptor than central corneal basal cells, suggesting that high levels of epidermal growth factor receptor help maintain the limbal basal cells in an undifferentiated stem cell state.

Developmental potential of trunk neural crest cells in the mouse.

Abstract: The availability of naturally occurring and engineered mutations in mice which affect the neural crest makes the mouse embryo an important experimental system for studying neural crest cell differentiation. Here, we determine the normal developmental potential of neural crest cells by performing in situ cell lineage analysis in the mouse by microinjecting lysinated rhodamine dextran (LRD) into individual dorsal neural tube cells in the trunk. Labeled progeny derived from single cells were found in the neural tube, dorsal root ganglia, sympathoadrenal derivatives, presumptive Schwann cells and/or pigment cells. Most embryos contained labeled cells both in the neural tube and at least one neural crest derivative, and numerous clones contributed to multiple neural crest derivatives. The time of injection influenced the derivatives populated by the labeled cells. Injections at early stages of migration yielded labeled progeny in both dorsal and ventral neural crest derivatives, whereas those performed at later stages had labeled cells only in more dorsal neural crest derivatives, such as dorsal root ganglion and presumptive pigment cells. The results suggest that in the mouse embryo: (1) there is a common precursor for neural crest and neural tube cells; (2) some neural crest cells are multipotent; and (3) the timing of emigration influences the range of possible neural crest derivatives.

Genetically engineered mammalian neural crest stem cells

Abstract: The invention includes mammalian multipotent neural stem cells and their progeny and methods for the isolation and clonal propagation of such cells. At the clonal level the stem cells are capable of self regeneration and asymmetrical division. Lineage restriction is demonstrated within developing clones which are sensitive to the local environment. The invention also includes such cells which are transfected with foreign nucleic acid, e.g., to produce an immortalized neural stem cell. The invention further includes transplantation assays which allow for the identification of mammalian multipotent neural stem cells from various tissues and methods for transplanting mammalian neural stem cells and/or neural or glial progenitors into mammals. A novel method for detecting antibodies to neural cell surface markers is disclosed as well as a monoclonal antibody to mouse LNGFR.

In vitro method for obtaining an isolated population of mammalian neural crest stem cells

Abstract: The invention includes methods for the isolation and clonal propagation of mammalian neural stem cells. The methods employ a novel separation and culturing regimen and bioassays for establishing the generation of neural stem cell derivatives. These methods result in the production of non-transformed neural stem cells and their progeny. The invention demonstrates, at the clonal level, the self regeneration and asymmetrical division of mammalian neural stem cells for the first time in feeder cell-independent cultures. Lineage restriction is demonstrated within a developing clone and is shown to be sensitive to the local environment. Multipotent neural stem cells cultured on a mixed substrate of poly-D-lysine and fibronectin generate PNS neurons and glia, but on fibronectin alone the stem cells generate PNS glia but not neurons. The neurogenic potential of the stem cells, while not expressed, is maintained over time on fibronectin. The invention further includes transplantation assays which allow for the identification of mammalian neural stem cells from various tissues. It also includes methods for transplanting mammalian neural stem cells and/or neural or glial progenitors into mammals.

Stem cells and transcription factors in the development of the mammalian neural crest.

Abstract: The neural crest is a migratory population of multipotent embryonic cells that generates the neurons and glia of the peripheral nervous system, as well as a variety of non-neural mesectodermal and endocrine cell types. The study of neural crest cell and molecular biology provides a system to investigate how such multipotent cells choose their fates, and whether the repertoire of fates becomes progressively restricted with time. The study of mammalian neural crest development has lagged behind studies of avian crest development due to the relative inaccessibility of mammalian embryos. The development of reverse genetic methods in mice, however, has made the analysis of mammalian neural crest development both more attractive and more tractable. Rodent neural crest cells have been isolated and grown in clonogenic cultures, where they behave as multipotent stem cells. This system provides an assay for factors that influence the differentiation of these multipotent cells. Transcription factors provide valuable early markers for neural crest cells as well as molecular handles on the lineage segregation process. One such factor is Mash1, a homolog of the Drosophila proneural genes, achaete-scute. Mash1 marks autonomic progenitor cells and is essential for their development in vivo, as shown by gene knockout experiments.

Genetic modification of neural stem cells.

Abstract: Genetically modified, epidermal growth factor-responsive neural stem cells are disclosed that are capable of differentiating into neurons, astrocytes, and oligodendrocytes in vitro. The stem cells can be proliferated in vitro to result in large numbers of cells for use in transplantation to treat various neurological disorders. The stem cells can be obtained from a human or other animal, cultured in vitro in the presence of a growth factor and genetically modified with desired DNA using techniques known in the art. Alternatively, the precursor cells can be derived from a transgenic animal which has had a desired gene inserted into its genome.

In situ modification and manipulation of stem cells of the central nervous system

Abstract: Endogenous precursor cells are manipulated/modified in situ to induce the cells, by the application of one or more growth factors or similar compounds, to proliferate, differentiate and migrate within the CNS so as to replace lost or non-functional cells. The precursor cells are also altered in situ (in vivo) so as to secrete a compound which alters the function of other differentiated CNS cells. The endogenous precursor cells can also be treated with one or more growth factors in situ in order to increase the yield of stem cells that can be isolated from the adult CNS and proliferated in vitro.

Autocrine factors sustain glioblastoma stem cell self- renewal

Abstract: Glioblastoma stem cells are able to reform original glioblastoma and express the neural stem cell marker CD133 and Nestin. They can self-renew and proliferate in tumor sphere medium containing EGF, bFGF and LIF that is known to be permissive for stem cell proliferation. In this study, we found that neurosphere-like colonies appeared after the human primary glioblastoma cells had been switched into pure DMEM/F12 medium. We investigated whether tumor spheres formed in pure DMEM/F12 medium possess the characteristics of glioblastoma stem cells. We identified that the tumor sphere cells were cancer stem cells of glioblastoma and they can self-renew and proliferate in pure DMEM/F12 medium. Glioblastoma cells can secrete several factors that result in autocrine motility signaling and stimulate glioma invasion. We hypothesized that an essential autocrine signal promotes the self-renewal and proliferation of human glioblastoma stem cells in pure DMEM/F12 medium. Then, expression of EGF and bFGF in glioblastoma stem cells were analyzed. Both the mRNA and protein of EGF and bFGF were detected in three human glioblastoma stem cells. Our findings suggest that autocrine of EGF and bFGF may sustain the self-renewal of glioblastoma stem cells. Oncology Reports

Transplantation of Epidermal Growth Factor-Responsive Neural Stem Cell Progeny into the Murine Central Nervous System

Abstract: Publisher Summary This chapter describes transplantation of epidermal growth factor (EGF)-responsive neural stem cell progeny into the murine central nervous system (CNS) Neurodegenerative disorders such as Alzheimer's, Parkinson's, and Huntington's disease, and also demyelinating disorders such as multiple sclerosis (MS) are of serious concern in the society Because of the wide array of CNS disorders, possible therapeutic approaches are also diverse and include cell replacement via transplantation, neurotrophic factor delivery from implants of polymer-encapsulated or unencapsulated genetically modified cell lines, etc This chapter describes aspects of a novel EGF-responsive stem cell culture system The EGF-responsive cells can be isolated from embryonic and adult rat and mouse brain, and similar cells have been isolated from fetal human brain Undifferentiated stem cell progeny are capable of forming oligodendrocytes when transplanted in vivo The chapter also describes the development of genetically tagged, EGF-responsive stem cells derived from transgenic mice These mice carry chimeric genes composed of mammalian cell-specific promoter elements that direct the expression of a reporter gene to either astrocytes or oligodendrocytes

In vitro amplification of stem cells

Abstract: The present invention relates to a method of amplifying in vitro stem cells. In this method stem cells are isolated from human bone marrow and contacted with endothelial cells. The contacted stem cells+ and endothelial cells are cultured in the presence of at least one cytokine in an amount sufficient to support expansion of the stem cells. This method produces increased yields of stem cells which can be used in human therapeutics.

Use of stem cell factor interleukin-6 and soluble interleukin-6 receptor to induce the development of hematopoietic stem cells

Abstract: Stem cell factor in combination with interleukin-6 and soluble interleukin-6 receptor supports proliferation, differentiation and terminal maturation of erythroid cells from normal human hematopoietic stem cells.

Stem Cells of Olfactory Cells During Development

Abstract: There are two types of basal cell in the basal region of the olfactory epithelium of mice: (1) The basal cells proper, which are in direct contact with the basement membrane, are positive for keratin as detected with anti-keratin antibodies [1–4]. (2) The globose basal cells, which lie between basal cells proper and olfactory cell nuclei, or often close to the basement membrane, are stained positively with antineural cell adhesion molecule (N-CAM) antibody [5,6] and are devoid of keratin [2]. An earlier study using [3 H]thymidine autoradiography revealed that basal cells proper divide and give rise to new olfactory cells via globose basal cells because olfactory cells are continuously replaced by stem cells [7]. We reported in a previous study combining immunohistochemistry of keratin with the bromodeoxyuridine (BrdU) method for labeling dividing cells that globose basal cells increase their mitotic activity after axotomy but that basal cells proper do not show any change in their mitotic rate, suggesting that globose basal cells are stem cells of olfactory cells [8]. These two types of basal cell have been shown to differentiate in the basal region of the olfactory epithelium at birth [2]; however, the changes in the mitotic activity of these cells during postnatal development have not been investigated.