Engraftment of sorted/expanded human central nervous system stem cells from fetal brain.
ABSTRACT Direct isolation of human central nervous system stem cells (CNS-SC) based on cell surface markers yields a highly purified stem cell population that can extensively expand in vitro and exhibit multilineage differentiation potential both in vitro and in vivo. The CNS-SC were isolated from fetal brain tissue using the cell surface markers CD133(+), CD34(-), CD45(-), and CD24(-/lo) (CD133(+) cells). Fluorescence-activated cell sorted (FACS) CD133(+) cells continue to expand exponentially as neurospheres while retaining multipotential differentiation capacity for >10 passages. CD133(-), CD34(-), and CD45(-) sorted cells (approximately 95% of total fetal brain tissue) fail to initiate neurospheres. Neurosphere cells transplanted into neonatal immunodeficient NOD-SCID mice proliferated, migrated, and differentiated in a site-specific manner. However, it has been difficult to evaluate human cell engraftment, because many of the available monoclonal antibodies against neural cells (beta-tubulin III and glial fibrillary acidic protein) are not species specific. To trace the progeny of human cells after transplantation, CD133(+)-derived neurosphere cells were transduced with lentiviral vectors containing enhanced green fluorescent protein (eGFP) expressed downstream of the phosphoglycerate kinase promoter. After transduction, GFP(+) cells were enriched by FACS, expanded, and transplanted into the lateral ventricular space of neonatal immunodeficient NOD-SCID brain. The progeny of transplanted cells were detected by either GFP fluorescence or antibody against GFP. GFP(+) cells were present in the subventricular zone-rostral migrating stream, olfactory bulb, and hippocampus as well as nonneurogenic sites, such as cerebellum, cerebral cortex, and striatum. Antibody against GFP revealed that some of the cells displayed differentiating dendrites and processes with neurons or glia cells. Thus, marking human CNS-SC with reporter genes introduced by lentiviral vectors is a useful tool with which to characterize migration and differentiation of human cells in this mouse transplantation model.
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ABSTRACT: BACKGROUND: The intricate regulation of several signaling pathways is essential for embryonic development and adult tissue homeostasis. Cancers commonly display aberrant activity within these pathways. A population of cells identified in several cancers, termed cancer stem cells (CSCs) show similar properties to normal stem cells and evidence suggests that altered developmental signaling pathways play an important role in maintaining CSCs and thereby the tumor itself. Scope of Review This review will focus on the roles of the Notch, Wnt and Hedgehog pathways in brain, breast and colon cancers. We describe the roles these pathways play in normal tissue homeostasis through the regulation of stem cell fate in these three tissues, and the experimental evidence indicating that the role of these pathways in cancers of these is directly linked to CSCs. Major Conclusions A large body of evidence is accumulating to indicate that the deregulation of Notch, Wnt and Hedgehog pathways play important roles in both normal and cancer stem cells. We are only beginning to understand how these pathways interact, how they are coordinated during normal development and adult tissue homeostasis, and how they are deregulated during cancer. However, it is becoming increasingly clear that if we are to target CSCs therapeutically, it will likely be necessary to develop combination therapies. General Significance If CSCs are the driving force behind tumor maintenance and growth then understanding the molecular mechanisms regulating CSCs is essential. Such knowledge will contribute to better targeted therapies that could significantly enhance cancer treatments and patient survival. This article is part of a Special Issue entitled Biochemistry of Stem Cells.Biochimica et Biophysica Acta 11/2012; · 4.66 Impact Factor
Article: Transplantation of human neural stem/progenitor cells overexpressing galectin-1 improves functional recovery from focal brain ischemia in the Mongolian gerbil.[show abstract] [hide abstract]
ABSTRACT: Transplantation of human neural stem/progenitor cells (hNSPCs) is a promising method to regenerate tissue from damage and recover function in various neurological diseases including brain ischemia. Galectin-1(Gal1) is a lectin that is expressed in damaged brain areas after ischemia. Here, we characterized the detailed Gal1 expression pattern in an animal model of brain ischemia. After brain ischemia, Gal1 was expressed in reactive astrocytes within and around the infarcted region, and its expression diminished over time. Previously, we showed that infusion of human Gal1 protein (hGal1) resulted in functional recovery after brain ischemia but failed to reduce the volume of the ischemic region. This prompted us to examine whether the combination of hNSPCs-transplantation and stable delivery of hGal1 around the ischemic region could reduce the ischemic volume and promote better functional recovery after brain ischemia. In this study, we transplanted hNSPCs that stably overexpressed hGal1 (hGal1-hNSPCs) in a model of unilateral focal brain ischemia using Mongolian gerbils. Indeed, we found that transplantation of hGal1-hNSPCs both reduced the ischemic volume and improved deficits in motor function after brain ischemia to a greater extent than the transplantation of hNSPCs alone. This study provides evidence for a potential application of hGal1 with hNSPCs-transplantation in the treatment of brain ischemia.Molecular Brain 09/2011; 4:35.
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ABSTRACT: Shiverer-immunodeficient (Shi-id) mice demonstrate defective myelination in the central nervous system (CNS) and significant ataxia by 2 to 3 weeks of life. Expanded, banked human neural stem cells (HuCNS-SCs) were transplanted into three sites in the brains of neonatal or juvenile Shi-id mice, which were asymptomatic or showed advanced hypomyelination, respectively. In both groups of mice, HuCNS-SCs engrafted and underwent preferential differentiation into oligodendrocytes. These oligodendrocytes generated compact myelin with normalized nodal organization, ultrastructure, and axon conduction velocities. Myelination was equivalent in neonatal and juvenile mice by quantitative histopathology and high-field ex vivo magnetic resonance imaging, which, through fractional anisotropy, revealed CNS myelination 5 to 7 weeks after HuCNS-SC transplantation. Transplanted HuCNS-SCs generated functional myelin in the CNS, even in animals with severe symptomatic hypomyelination, suggesting that this strategy may be useful for treating dysmyelinating diseases.Science translational medicine 10/2012; 4(155):155ra136. · 7.80 Impact Factor