scholarly journals Regulation of miRNAs during Retinoic Acid-Induced Regeneration of a Molluscan Central Nervous System

2018 ◽  
Author(s):  
Sarah E. Walker ◽  
Gaynor E. Spencer ◽  
Alexsandr Necakov ◽  
Robert L. Carlone
Keyword(s):  
Nervous System ◽  
Retinoic Acid ◽  
Lymnaea Stagnalis ◽  
System Development ◽  
Growth Cones ◽  
Nervous System Development ◽  
Biologically Active ◽  
Neuronal Outgrowth ◽  
First Time

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.

scholarly journals Identification and Characterization of microRNAs during Retinoic Acid-Induced Regeneration of a Molluscan Central Nervous System

2018 ◽  
Vol 19 (9) ◽  
pp. 2741 ◽  
Author(s):  
Sarah Walker ◽  
Gaynor Spencer ◽  
Aleksandar Necakov ◽  
Robert Carlone
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Retinoic Acid ◽  
Lymnaea Stagnalis ◽  
System Development ◽  
Growth Cones ◽  
Nervous System Development ◽  
Biologically Active ◽  
Sequencing Analysis

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 miRNA sequencing analysis, we identify 482 miRNAs in the regenerating central nervous system (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 in the growth cones of another class of respiratory motorneurons (right parietal A) was absent in vitro. These findings support our hypothesis that miRNAs are important regulators of retinoic acid-induced neuronal outgrowth and regeneration in regeneration-competent species.

scholarly journals Identification and Characterization of microRNAs during Retinoic Acid-Induced Regeneration of a Molluscan Central Nervous System

2018 ◽  
Author(s):  
Sarah E. Walker ◽  
Gaynor E. Spencer ◽  
Aleksandar Necakov ◽  
Robert L. Carlone
Keyword(s):  
Nervous System ◽  
Retinoic Acid ◽  
Lymnaea Stagnalis ◽  
System Development ◽  
Growth Cones ◽  
Nervous System Development ◽  
Biologically Active ◽  
Sequencing Analysis ◽  
Mirna Sequencing

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 miRNA-Sequencing 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 in the growth cones of another class of respiratory motorneurons (RPA) was absent in vitro. These findings support our hypothesis that miRNAs are important regulators of retinoic acid-induced neuronal outgrowth and regeneration in regeneration-competent species.

scholarly journals Drosophila Stathmin: A Microtubule-destabilizing Factor Involved in Nervous System Formation

2002 ◽  
Vol 13 (2) ◽  
pp. 698-710 ◽  
Author(s):  
Sylvie Ozon ◽  
Antoine Guichet ◽  
Olivier Gavet ◽  
Siegfried Roth ◽  
André Sobel
Keyword(s):  
Nervous System ◽  
System Development ◽  
Nervous System Development ◽  
Microtubule Assembly ◽  
Nervous Systems ◽  
Germ Cell Migration ◽  
Numerous Cell ◽  
First Time

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.

scholarly journals Retinoic acid treatment recruits macrophages and increases axonal regeneration after optic nerve injury in the frog Rana pipiens

2021 ◽  
Author(s):  
Valeria De La Rosa-Reyes ◽  
Mildred V Duprey-Díaz ◽  
Jonathan M Blagburn ◽  
Rosa E Blanco
Keyword(s):  
Nervous System ◽  
Retinoic Acid ◽  
Optic Nerve ◽  
Nerve Injury ◽  
Phagocytic Activity ◽  
Axonal Regeneration ◽  
Ganglion Cells ◽  
System Development ◽  
Nervous System Development ◽  
Optic Nerve Injury

Retinoic acid (RA) plays major roles during nervous system development, and during regeneration of the adult nervous system. We have previously shown that components of the RA signaling pathway are upregulated after optic nerve injury, and that exogenous application of all-trans retinoic acid (ATRA) greatly increases the survival of axotomized retinal ganglion cells (RGCs). The objective of the present study is to investigate the effects of ATRA application on the macrophages in the optic nerve after injury, and to determine whether this affects axonal regeneration. The optic nerve was crushed and treated with PBS, ATRA and/or clodronate-loaded liposomes. Nerves were examined at one and two weeks after axotomy with light microscopy, immunocytochemistry and electron microscopy. ATRA application to the optic nerve caused transient increases in the number of macrophages and microglia one week after injury. The macrophages are consistently labeled with M2-type markers, and have considerable phagocytic activity. ATRA increased ultrastructural features of ongoing phagocytic activity in macrophages at one and two weeks. ATRA treatment also significantly increased the numbers of regenerating GAP-43-labeled axons. Clodronate liposome treatment depleted macrophage numbers by 80%, completely eliminated the ATRA-mediated increase in axonal regeneration, and clodronate treatment alone decreased axonal numbers by 30%. These results suggest that the success of axon regeneration is partially dependent on the presence of debris-phagocytosing macrophages, and that the increases in regeneration caused by ATRA are in part due to their increased numbers. Further studies will examine whether macrophage depletion affects RGC survival.

scholarly journals Modeling Brain Somatic Mosaicism With Cerebral Organoids, Including a Note on Mutant Microglia

2019 ◽  
Vol 12 ◽  
Author(s):  
Bert M. Verheijen
Keyword(s):  
Nervous System ◽  
System Development ◽  
Somatic Mosaicism ◽  
3D Culture ◽  
3D Cell Culture ◽  
Nervous System Development ◽  
Genomic Diversity ◽  
Human Organ ◽  
Development And Aging

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.

13-cis-Retinoic Acid Alters Intracellular Serotonin, Increases 5-HT1A Receptor, and Serotonin Reuptake Transporter Levels In Vitro

2007 ◽  
Vol 232 (9) ◽  
pp. 1195-1203 ◽  
Author(s):  
Kally C. O’Reilly ◽  
Simon Trent ◽  
Sarah J. Bailey ◽  
Michelle A. Lane
Keyword(s):  
Retinoic Acid ◽  
Cell Line ◽  
Serotonin Reuptake ◽  
System Development ◽  
Chronic Administration ◽  
Nervous System Development ◽  
Adult Brain ◽  
Adolescent Male ◽  
Serotonin Reuptake Transporter

In addition to their established role in nervous system development, vitamin A and related retinoids are emerging as regulators of adult brain function. Accutane (13- cis-retinoic acid, isotretinoin) treatment has been reported to increase depression in humans. Recently, we showed that chronic administration of 13- cis-retinoic acid (13- cis-RA) to adolescent male mice increased depression-related behaviors. Here, we have examined whether 13- cis-RA regulates components involved in serotonergic neurotransmission in vitro. We used the RN46A-B14 cell line, derived from rat embryonic raphe nuclei. This cell line synthesizes serotonin (5-hydroxytryptamine, 5-HT) and expresses the 5-HT1A receptor and the serotonin reuptake transporter (SERT). Cells were treated with 0, 2.5, or 10 μ M 13- cis-RA for 48 or 96 hrs, and the levels of 5-HT; its metabolite, 5-hydroxyindoleacetic acid (5HIAA); 5-HT1A receptor; and SERT were determined. Treatment with 13- cis-RA for 96 hrs increased the intracellular levels of 5-HT and tended to increase intra-cellular 5HIAA levels. Furthermore, 48 hrs of treatment with 2.5 and 10 μ M 13- cis-RA significantly increased 5-HT1A protein to 168.5 ± 20.0% and 148.7 ± 2.2% of control respectively. SERT protein levels were significantly increased to 142.5 ± 11.1% and 119.2 ± 3.6% of control by 48 hrs of treatment with 2.5 and 10 μ M of 13- cis-RA respectively. Increases in both 5-HT1A receptor and SERT proteins may lead to decreased serotonin availability at synapses. Such an effect of 13- cis-RA could contribute to the increased depression-related behaviors we have shown in mice.

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
Keyword(s):  
Stem Cells ◽  
Nervous System ◽  
Neural Differentiation ◽  
System Development ◽  
Nervous System Development ◽  
Neural Cells ◽  
Ageing Population ◽  
Bioinformatic Tools ◽  
Functional Characterisation

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.

scholarly journals Different Subcellular Localization of ALCAM Molecules in Neuroblastoma: Association with Relapse

2010 ◽  
Vol 32 (1-2) ◽  
pp. 77-86
Author(s):  
Maria Valeria Corrias ◽  
Claudio Gambini ◽  
Andrea Gregorio ◽  
Michela Croce ◽  
Gaia Barisione ◽  
...  
Keyword(s):  
Nervous System ◽  
Subcellular Localization ◽  
Cell Lines ◽  
System Development ◽  
Neuroblastoma Cell ◽  
Neuroblastoma Cells ◽  
Nervous System Development ◽  
Primary Tumors ◽  
Neuroblastoma Cell Lines

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.

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