Neurons from stem cells: Implications for understanding nervous system development and repair

2000 ◽  
Vol 78 (5) ◽  
pp. 613-628 ◽  
Author(s):  
Fiona C Mansergh ◽  
Michael A Wride ◽  
Derrick E Rancourt

Neurodegenerative diseases cost the economies of the developed world billions of dollars per annum. Given ageing population profiles and the increasing extent of this problem, there has been a surge of interest in neural stem cells and in neural differentiation protocols that yield neural cells for therapeutic transplantation. Due to the oncogenic potential of stem cells a better characterisation of neural differentiation, including the identification of new neurotrophic factors, is required. Stem cell cultures undergoing synchronous in vitro neural differentiation provide a valuable resource for gene discovery. Novel tools such as microarrays promise to yield information regarding gene expression in stem cells. With the completion of the yeast, C. elegans, Drosophila, human, and mouse genome projects, the functional characterisation of genes using genetic and bioinformatic tools will aid in the identification of important regulators of neural differentiation.Key words: neural differentiation, neural precursor cell, brain repair, central nervous system repair, CNS.

2002 ◽  
Vol 13 (2) ◽  
pp. 698-710 ◽  
Author(s):  
Sylvie Ozon ◽  
Antoine Guichet ◽  
Olivier Gavet ◽  
Siegfried Roth ◽  
André Sobel

Stathmin is a ubiquitous regulatory phosphoprotein, the generic element of a family of neural phosphoproteins in vertebrates that possess the capacity to bind tubulin and interfere with microtubule dynamics. Although stathmin and the other proteins of the family have been associated with numerous cell regulations, their biological roles remain elusive, as in particular inactivation of the stathmin gene in the mouse resulted in no clear deleterious phenotype. We identified stathmin phosphoproteins inDrosophila, encoded by a unique gene sharing the intron/exon structure of the vertebrate stathmin andstathmin family genes. They interfere with microtubule assembly in vitro, and in vivo when expressed in HeLa cells. Drosophila stathmin expression is regulated during embryogenesis: it is high in the migrating germ cells and in the central and peripheral nervous systems, a pattern resembling that of mammalian stathmin. Furthermore, RNA interference inactivation ofDrosophila stathmin expression resulted in germ cell migration arrest at stage 14. It also induced important anomalies in nervous system development, such as loss of commissures and longitudinal connectives in the ventral cord, or abnormal chordotonal neuron organization. In conclusion, a single Drosophilagene encodes phosphoproteins homologous to the entire vertebrate stathmin family. We demonstrate for the first time their direct involvement in major biological processes such as development of the reproductive and nervous systems.


2019 ◽  
Vol 28 (12) ◽  
pp. 1686-1699 ◽  
Author(s):  
Chongfeng Chen ◽  
Yujia Yang ◽  
Yue Yao

Hyperbaric oxygen (HBO) therapy may promote neurological recovery from hypoxic-ischemic encephalopathy (HIE). However, the therapeutic effects of HBO and its associated mechanisms remain unknown. The canonical Wnt/β-catenin signaling pathways and bone morphogenetic protein (BMP) play important roles in mammalian nervous system development. The present study examined whether HBO stimulates the differentiation of neural stem cells (NSCs) and its effect on Wnt3/β-catenin and BMP2 signaling pathways. We showed HBO treatment (2 ATA, 60 min) promoted differentiation of NSCs into neurons and oligodendrocytes in vitro. In addition, rat hypoxic-ischemic brain damage (HIBD) tissue extracts also promoted the differentiation of NSCs into neurons and oligodendrocytes, with the advantage of reducing the number of astrocytes. These effects were most pronounced when these two were combined together. In addition, the expression of Wnt3a, BMP2, and β-catenin nuclear proteins were increased after HBO treatment. However, blockade of Wnt/β-catenin or BMP signaling inhibited NSC differentiation and reduced the expression of Wnt3a, BMP2, and β-catenin nuclear proteins. In conclusion, HBO promotes differentiation of NSCs into neurons and oligodendrocytes and reduced the number of astrocytes in vitro possibly through regulation of Wnt3/β-catenin and BMP2 signaling pathways. HBO may serve as a potential therapeutic strategy for treating HIE.


2017 ◽  
Author(s):  
Jonathan Enriquez ◽  
Laura Quintana Rio ◽  
Richard Blazeski ◽  
Carol Mason ◽  
Richard S. Mann

SummaryIn both vertebrates and invertebrates, neurons and glia are generated in a stereotyped order from dedicated progenitors called neural stem cells, but the purpose of invariant lineages is not understood. Here we show that three of the stem cells that produce leg motor neurons in Drosophila also generate a specialized subset of glia, the neuropil glia, which wrap and send processes into the neuropil where motor neuron dendrites arborize. The development of the neuropil glia and leg motor neurons is highly coordinated. However, although individual motor neurons have a stereotyped birth order and transcription factor code, both the number and individual morphologies of the glia born from these lineages are highly plastic, even though the final structure they contribute to is highly stereotyped. We suggest that the shared lineages of these two cell types facilitates the assembly of complex neural circuits, and that the two different birth order strategies – hardwired for motor neurons and flexible for glia – are important for robust nervous system development and homeostasis.


Author(s):  
Sarah E. Walker ◽  
Gaynor E. Spencer ◽  
Alexsandr Necakov ◽  
Robert L. Carlone

Retinoic acid (RA) is the biologically active metabolite of vitamin A,and has become a well-established factor that induces neurite outgrowth and regeneration in both vertebrates and invertebrates. However, the underlying regulatory mechanisms that may mediate RA-induced neurite sprouting remain unclear. In the past decade, microRNAs have emerged as important regulators of nervous system development and regeneration, and have been shown to contribute to processes such as neurite sprouting. However, few studies have demonstrated the role of miRNAs in RA-induced neurite sprouting. By R-Seq analysis, we identify 482 miRNAs in the regenerating CNS of the mollusc Lymnaea stagnalis, 219 of which represent potentially novel miRNAs. Of the remaining conserved miRNAs, 38 show a statistically significant up or downregulation in regenerating CNS as a result of RA treatment. We further characterized the expression of one neuronally-enriched miRNA upregulated by RA, miR-124. We demonstrate for the first time that miR-124 is expressed within the cell bodies and neurites of regenerating motorneurons. Moreover, we identify miR-124 expression within the growth cones of cultured ciliary motorneurons (Pedal A), whereas expression from the growth cones of another class of respiratory motorneurons (RPA) was absent in vitro. These findings support our hypothesis miRNAs are important regulators of retinoic acid induced neuronal outgrowth and regeneration in regeneration-competent species.


Author(s):  
Bert M. Verheijen

The brain is a genomic mosaic. Cell-to-cell genomic differences, which are the result of somatic mutations during development and aging, contribute to cellular diversity in the nervous system. This genomic diversity has important implications for nervous system development, function, and disease. Brain somatic mosaicism might contribute to individualized behavioral phenotypes and has been associated with several neuropsychiatric and neurodegenerative disorders. Therefore, understanding the causes and consequences of somatic mosaicism in neural circuits is of great interest. Recent advances in 3D cell culture technology have provided new means to study human organ development and various human pathologies in vitro. Cerebral organoids (“mini-brains”) are pluripotent stem cell-derived 3D culture systems that recapitulate, to some extent, the developmental processes and organization of the developing human brain. Here, I discuss the application of these neural organoids for modeling brain somatic mosaicism in a lab dish. Special emphasis is given to the potential role of microglial mutations in the pathogenesis of neurodegenerative diseases.


2010 ◽  
Vol 32 (1-2) ◽  
pp. 77-86
Author(s):  
Maria Valeria Corrias ◽  
Claudio Gambini ◽  
Andrea Gregorio ◽  
Michela Croce ◽  
Gaia Barisione ◽  
...  

Background: The Activated Leukocyte Cell Adhesion Molecule (ALCAM/CD), involved in nervous system development, has been linked to tumor progression and metastasis in several tumors. No information is available on ALCAM expression in neuroblastoma, a childhood neoplasia originating from the sympathetic nervous system.Methods: ALCAM expression was analysed by immunofluorescence and immunohistochemistry on differentiated neuroblastoma cell lines and on archival specimens of stroma-poor, not MYCN amplified, resectable neuroblastoma tumors, respectively.Results: ALCAM is variously expressed in neuroblastoma cell lines, is shed by metalloproteases and is cleaved by ADAM17/TACE in vitro. ALCAM is expressed in neuroblastoma primary tumors with diverse patterns of subcellular localization and is highly expressed in the neuropil area in a subgroup of cases. Tumor specimens showing high expression of ALCAM at the membrane of the neuroblast body or low levels in the neuropil area are associated with relapse (P = 0.044 and P < 0.0001, respectively). In vitro differentiated neuroblastoma cells show strong ALCAM expression on neurites, suggesting that ALCAM expression in the neuropil is related to a differentiated phenotype.Conclusions: Assessment of ALCAM localization by immunohistochemistry may help to identify patients who, in the absence of negative prognostic factors, are at risk of relapse and require a more careful follow-up.


2018 ◽  
Author(s):  
Angela K. Tiethof ◽  
Jason R. Richardson ◽  
Ronald P. Hart

AbstractButyrylcholinesterase (BChE) is the evolutionary counterpart to acetylcholinesterase (AChE). Both are expressed early in nervous system development prior to cholinergic synapse formation. The organophosphate pesticide chlorpyrifos (CPF) primarily exerts toxicity through inhibition of AChE, which results in excess cholinergic stimulation at the synapse. We hypothesized that inhibition of AChE and BChE by CPF may impair early neurogenesis in neural stem cells (NSCs). To model neurodevelopment in vitro, we used human NSCs derived from induced pluripotent stem cells (iPSCs) with a focus on initial differentiation mechanisms. Over six days of NSC differentiation, BChE activity and mRNA expression significantly increased, while AChE activity and expression remained unchanged. CPF treatment (10 μM) caused 82% and 92% inhibition of AChE and BChE, respectively. CPF exposure had no effect on cell viability or the expression of differentiation markers HES5, DCX or MAP2. However, shRNA-knockdown of BChE expression resulted in decreased or delayed expression of transcription factors HES5 and HES3. BChE may have a role in the differentiation of NSCs independent of, or in addition to, its enzymatic activity.


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