251
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MicroRNA-9 regulates neurogenesis in mouse telencephalon by targeting multiple transcription factors. J Neurosci 2011; 31:3407-22. [PMID: 21368052 DOI: 10.1523/jneurosci.5085-10.2011] [Citation(s) in RCA: 251] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
microRNA-9-2 and microRNA-9-3 double-mutant mice demonstrate that microRNA-9 (miR-9) controls neural progenitor proliferation and differentiation in the developing telencephalon by regulating the expression of multiple transcription factors. As suggested by our previous study, the Foxg1 expression was elevated, and the production of Cajal-Retzius cells and early-born neurons was suppressed in the miR-9-2/3 double-mutant pallium. At embryonic day 16.5 (E16.5), however, the Foxg1 expression was no longer elevated. The expression of an AU-rich RNA-binding protein Elavl2 increased at E16.5, Elav2 associated with Foxg1 3' untranslated region (UTR), and it countered the Foxg1 suppression by miR-9. Later, progenitor proliferation was reduced in the miR-9-2/3 double-mutant pallium with the decrease in Nr2e1 and Pax6 expression and the increase in Meis2 expression. The analyses suggest that microRNA-9 indirectly inhibits Pax6 expression by suppressing Meis2 expression. In contrast, together with Elavl1 and Msi1, microRNA-9 targets Nr2e1 mRNA 3' UTR to enhance the expression. Concomitantly, cortical layers were reduced, each cortical projection was malformed, and the tangential migration of interneurons into the pallium was impaired in the miR-9-2/3 double mutants. miR-9 also targets Gsh2 3' UTR, and Gsh2, as well as Foxg1, expression was elevated in the miR-9-2/3 double-mutant subpallium. The subpallium progenitor proliferation was enhanced, and the development of basal ganglia including striatum and globus pallidus was suppressed. Pallial/subpallial boundary shifted dorsally, and the ventral pallium was lost. Corridor was malformed, and thalamocortical and corticofugal axons were misrouted in the miR-9-2/3 double mutants.
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252
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Dentate gyrus neurogenesis, integration and microRNAs. Behav Brain Res 2011; 227:348-55. [PMID: 21443907 DOI: 10.1016/j.bbr.2011.03.048] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 02/24/2011] [Accepted: 03/20/2011] [Indexed: 12/15/2022]
Abstract
Neurons are born and become a functional part of the synaptic circuitry in adult brains. The proliferative phase of neurogenesis has been extensively reviewed. We therefore focus this review on a few topics addressing the functional role of adult-generated newborn neurons in the dentate gyrus. We discuss the evidence for a link between neurogenesis and behavior. We then describe the steps in the integration of newborn neurons into a functioning mature synaptic circuit. Given the profound effects of neural activity on the differentiation and integration of newborn neurons, we discuss the role of activity-dependent gene expression in the birth and maturation of newborn neurons. The differentiation and maturation of newborn neurons likely involves the concerted action of many genes. Thus we focus on transcription factors that can direct large changes to the transcriptome, and microRNAs, a newly-discovered class of molecules that can effect the expression of hundreds of genes. How microRNAs affect the generation and integration of newborn neurons is just being explored, but there are compelling clues hinting at their involvement.
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253
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Schiappacassi M, Lovisa S, Lovat F, Fabris L, Colombatti A, Belletti B, Baldassarre G. Role of T198 modification in the regulation of p27(Kip1) protein stability and function. PLoS One 2011; 6:e17673. [PMID: 21423803 PMCID: PMC3056717 DOI: 10.1371/journal.pone.0017673] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 02/11/2011] [Indexed: 12/16/2022] Open
Abstract
The tumor suppressor gene p27Kip1 plays a fundamental role in human cancer progression. Its expression and/or functions are altered in almost all the different tumor histotype analyzed so far. Recently, it has been demonstrated that the tumor suppression function of p27 resides not only in the ability to inhibit Cyclins/CDKs complexes through its N-terminal domain but also in the capacity to modulate cell motility through its C-terminal portion. Particular interest has been raised by the last amino-acid, (Threonine 198) in the regulation of both protein stability and cell motility. Here, we describe that the presence of Threonine in position 198 is of primary importance for the regulation of the protein stability and for the control of cell motility. However, while the control of cell motility is dependent on the phosphorylation of T198, the stability of the protein is specifically controlled by the steric hindrance of the last amino acid. The effects of T198 modification on protein stability are not linked to the capacity of p27 to bind Cyclins/CDKs complexes and/or the F-box protein Skp2. Conversely, our results support the hypothesis that conformational changes in the disordered structure of the C-terminal portion of p27 are important in its ability to be degraded via a proteasome-dependent mechanism. On the other hand T198 phosphorylation favors p27/stathmin interaction eventually contributing to the regulation of cell motility, supporting the hypothesis that the presence of T198 is fundamental for the regulation of p27 functions.
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Affiliation(s)
- Monica Schiappacassi
- Division of Experimental Oncology 2, Centro di Riferimento Oncologico, National Cancer Institute, Aviano, Italy
| | - Sara Lovisa
- Division of Experimental Oncology 2, Centro di Riferimento Oncologico, National Cancer Institute, Aviano, Italy
| | - Francesca Lovat
- Division of Experimental Oncology 2, Centro di Riferimento Oncologico, National Cancer Institute, Aviano, Italy
| | - Linda Fabris
- Division of Experimental Oncology 2, Centro di Riferimento Oncologico, National Cancer Institute, Aviano, Italy
| | - Alfonso Colombatti
- Division of Experimental Oncology 2, Centro di Riferimento Oncologico, National Cancer Institute, Aviano, Italy
| | - Barbara Belletti
- Division of Experimental Oncology 2, Centro di Riferimento Oncologico, National Cancer Institute, Aviano, Italy
| | - Gustavo Baldassarre
- Division of Experimental Oncology 2, Centro di Riferimento Oncologico, National Cancer Institute, Aviano, Italy
- * E-mail:
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254
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Iwaniuk KM, Schira J, Weinhold S, Jung M, Adjaye J, Müller HW, Wernet P, Trompeter HI. Network-like impact of MicroRNAs on neuronal lineage differentiation of unrestricted somatic stem cells from human cord blood. Stem Cells Dev 2011; 20:1383-94. [PMID: 21067317 DOI: 10.1089/scd.2010.0341] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Unrestricted somatic stem cells (USSCs) represent an intrinsically multipotent CD45-negative fetal population from human cord blood. They show differentiation into neuronal cells of a dopaminergic phenotype, which express neuronal markers such as synaptophysin, neuronal-specific nuclear protein, and neurofilament and release the neurotransmitter dopamine accompanied by expression of dopaminergic key factors tyrosine hydroxylase and Nurr1 (NR4A2). MicroRNA expression analysis highlighted their importance in neural development but their specific functions remain poorly understood. Here, downregulation of a set of 18 microRNAs during neuronal lineage differentiation of unrestricted somatic stem cells, including members of the miR-17-92 family and additional microRNAs such as miR-130a, -138, -218, and -335 as well as their target genes, is described. In silico target gene predictions for this microRNA group uncovered a large set of proteins involved in neuronal differentiation and having a strong impact on differentiation-related pathways such as axon guidance and TGFβ, WNT, and MAPK signaling. Experimental target validations confirmed approximately 35% of predictions tested and revealed a group of proteins with specific impact on neuronal differentiation and function including neurobeachin, neurogenic differentiation 1, cysteine-rich motor neuron protein 1, neuropentraxin 1, and others. These proteins are combined targets for several subgroups from the set of 18 downregulated microRNAs. This finding was further supported by the observed upregulation of a significant amount of predicted and validated target genes based on Illumina Beadstudio microarray data. Confirming the functional relationship of a limited panel of microRNAs and predicted target proteins reveals a clear network-like impact of the group of 18 downregulated microRNAs on proteins involved in neuronal development and function.
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Affiliation(s)
- Katharina M Iwaniuk
- Medical Faculty, University Düsseldorf, Institute for Transplantation Diagnostics and Cell Therapeutics, Düsseldorf, Germany
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255
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Bonev B, Pisco A, Papalopulu N. MicroRNA-9 reveals regional diversity of neural progenitors along the anterior-posterior axis. Dev Cell 2011; 20:19-32. [PMID: 21238922 PMCID: PMC3361082 DOI: 10.1016/j.devcel.2010.11.018] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 10/11/2010] [Accepted: 11/19/2010] [Indexed: 12/19/2022]
Abstract
Neural progenitors self-renew and generate neurons throughout the central nervous system. Here, we uncover an unexpected regional specificity in the properties of neural progenitor cells, revealed by the function of a microRNA—miR-9. miR-9 is expressed in neural progenitors, and its knockdown results in an inhibition of neurogenesis along the anterior-posterior axis. However, the underlying mechanism differs—in the hindbrain, progenitors fail to exit the cell cycle, whereas in the forebrain they undergo apoptosis, counteracting the proliferative effect. Among several targets, we functionally identify hairy1 as a primary target of miR-9, regulated at the mRNA level. hairy1 mediates the effects of miR-9 on proliferation, through Fgf8 signaling in the forebrain and Wnt signaling in the hindbrain, but affects apoptosis only in the forebrain, via the p53 pathway. Our findings show a positional difference in the responsiveness of progenitors to miR-9 depletion, revealing an underlying divergence of their properties.
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Affiliation(s)
- Boyan Bonev
- Faculty of Life Sciences, Michael Smith Building, University of Manchester, Oxford Road, Manchester M13 9PT, UK
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256
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Alcantara Llaguno SR, Chen Y, McKay RM, Parada LF. Stem Cells in Brain Tumor Development. Curr Top Dev Biol 2011; 94:15-44. [DOI: 10.1016/b978-0-12-380916-2.00002-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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257
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MicroRNA function in the nervous system. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 102:47-100. [PMID: 21846569 DOI: 10.1016/b978-0-12-415795-8.00004-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
MicroRNAs (miRNAs) are an extensive class of small noncoding RNAs that control posttranscriptional gene expression. miRNAs are highly expressed in neurons where they play key roles during neuronal differentiation, synaptogenesis, and plasticity. It is also becoming increasingly evident that miRNAs have a profound impact on higher cognitive functions and are involved in the etiology of several neurological diseases and disorders. In this chapter, we summarize our current knowledge of miRNA functions during neuronal development, physiology, and dysfunction.
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258
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Abstract
MicroRNAs are a class of small RNA regulators that are involved in numerous cellular processes, including development, proliferation, differentiation, and plasticity. The emerging concept is that microRNAs play a central role in controlling the balance between stem cell self-renewal and fate determination by regulating the expression of stem cell regulators. This review will highlight recent advances in the regulation of neural stem cell self-renewal and neurogenesis by microRNAs. It will cover microRNA functions during the entire process of neurogenesis, from neural stem cell self-renewal and fate determination to neuronal maturation, synaptic formation, and plasticity. The interplay between microRNAs and both cell-intrinsic and -extrinsic stem cell players, including transcription factors, epigenetic regulators, and extrinsic signaling molecules will be discussed. This is a summary of the topics covered in the mini-symposium on microRNA regulation of neural stem cells and neurogenesis in SFN 2010 and is not meant to be a comprehensive review of the subject.
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259
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microRNAs: tiny RNA molecules, huge driving forces to move the cell. Protein Cell 2010; 1:916-26. [PMID: 21204018 DOI: 10.1007/s13238-010-0116-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 10/09/2010] [Indexed: 12/19/2022] Open
Abstract
Cell migration or movement is a highly dynamic cellular process, requiring precise regulation that is essential for a variety of biological processes. microRNAs (miRNAs) are a class of tiny non-coding RNA molecules that function as critical post-transcriptional regulators of gene expression. Emerging evidence demonstrates that miRNAs play important roles in cell migration and directly contribute to extracellular matrix (ECM) remodeling, cell adhesion, and cell signalling that controls cell migration by targeting a large number of protein-coding genes. Accordingly, the dysregulation of these miRNAs has been linked to several migration-related diseases. In this review, we summarize and highlight the recent advances concerning the roles and validated targets of miRNAs in the control of cell movement.
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260
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Epigenetic control of stem cell fate to neurons and glia. Arch Pharm Res 2010; 33:1467-73. [DOI: 10.1007/s12272-010-1001-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2010] [Revised: 08/27/2010] [Accepted: 08/29/2010] [Indexed: 01/24/2023]
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261
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Abstract
Unique expression domains, targets, and gain- and loss-of-function phenotypes of particular microRNAs have important implications for directed differentiation of stem cell populations and suppression of undesired cell types. We discuss this emerging topic, in part using muscle differentiation as a paradigm, and highlight common themes and unique modalities by which microRNAs exert their lineage-promoting or differentiation effects on multiple tissues.
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Affiliation(s)
- Kathryn N Ivey
- Department of Pediatrics, Gladstone Institute of Cardiovascular Disease, University of California San Francisco, 1650 Owens Street, San Francisco, CA 94158, USA
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262
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Gao FB. Context-dependent functions of specific microRNAs in neuronal development. Neural Dev 2010; 5:25. [PMID: 20920300 PMCID: PMC2958854 DOI: 10.1186/1749-8104-5-25] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 10/01/2010] [Indexed: 12/15/2022] Open
Abstract
MicroRNAs (miRNAs) are small noncoding RNAs that regulate multiple developmental processes at the post-transcriptional level. Recent rapid progresses have demonstrated critical roles for a number of miRNAs in neuronal development and function. In particular, miR-9 and miR-124 are specifically expressed in the mammalian nervous system, and their respective nucleotide sequences are 100% identical among many species. Yet, their expression patterns and mRNA targets are less conserved throughout evolution. As a consequence, these miRNAs exhibit diverse context-dependent functions in different aspects of neuronal development, ranging from early neurogenesis and neuronal differentiation to dendritic morphogenesis and synaptic plasticity. Some other neuronal miRNAs also exhibit context-dependent functions in development. Thus, post-transcriptional regulation of spatial and temporal expression levels of protein-coding genes by miRNAs contributes uniquely to the proper development and evolution of the complex nervous system.
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Affiliation(s)
- Fen-Biao Gao
- Department of Neurology and Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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263
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Abstract
MicroRNAs play roles in developmental switching; however, their roles in human neural progenitor cells (hNPCs) is poorly understood. In this issue of Cell Stem Cell, Delaloy et al. (2010) report that proliferation and migration choices in hNPCs are regulated by miR-9.
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Affiliation(s)
- Nobuko Uchida
- StemCells Inc., 3155 Porter Drive, Palo Alto, CA 94301, USA.
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