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Brown M, Sciascia E, Ning K, Adam W, Veraksa A. Regulation of brain development by the Minibrain/Rala signaling network. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.10.593605. [PMID: 38766038 PMCID: PMC11100804 DOI: 10.1101/2024.05.10.593605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
The human dual specificity tyrosine phosphorylation regulated kinase 1A (DYRK1A) is implicated in the pathology of Down syndrome, microcephaly, and cancer, however the exact mechanism through which it functions is unknown. Here, we have studied the role of the Drosophila ortholog of DYRK1A, Minibrain (Mnb), in brain development. The neuroblasts (neural stem cells) that eventually give rise to differentiated neurons in the adult brain are formed from a specialized tissue in the larval optic lobe called the neuroepithelium, in a tightly regulated process. Molecular marker analysis of mnb mutants revealed alterations in the neuroepithelium and neuroblast regions of developing larval brains. Using affinity purification-mass spectrometry (AP-MS), we identified the novel Mnb binding partners Ral interacting protein (Rlip) and RALBP1 associated Eps domain containing (Reps). Rlip and Reps physically and genetically interact with Mnb, and the three proteins may form a ternary complex. Mnb phosphorylates Reps, and human DYRK1A binds to the Reps orthologs REPS1 and REPS2. Furthermore, Mnb engages the small GTPase Ras-like protein A (Rala) to regulate brain and wing development. This work uncovers a previously unrecognized early role of Mnb in the neuroepithelium and defines the functions of the Mnb/Reps/Rlip/Rala signaling network in brain development. Significance statement The kinase Minibrain(Mnb)/DYRK1A regulates the development of the brain and other tissues across many organisms. Here we show the critical importance of Mnb within the developing neuroepithelium. Advancing our understanding of Mnb function, we identified novel protein interactors of Mnb, Reps and Rlip, which function together with Mnb to regulate growth in Drosophila melanogaster . We also identify and characterize a role for the small GTPase Rala in Mnb-regulated growth and nervous system development. This work reveals an early role of Mnb in brain development and identifies a new Mnb/Reps/Rlip/Rala signaling axis.
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Malin JA, Chen YC, Simon F, Keefer E, Desplan C. Spatial patterning controls neuron numbers in the Drosophila visual system. Dev Cell 2024; 59:1132-1145.e6. [PMID: 38531357 PMCID: PMC11078608 DOI: 10.1016/j.devcel.2024.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 12/18/2023] [Accepted: 03/01/2024] [Indexed: 03/28/2024]
Abstract
Neurons must be made in the correct proportions to communicate with the appropriate synaptic partners and form functional circuits. In the Drosophila visual system, multiple subtypes of distal medulla (Dm) inhibitory interneurons are made in distinct, reproducible numbers-from 5 to 800 per optic lobe. These neurons are born from a crescent-shaped neuroepithelium called the outer proliferation center (OPC), which can be subdivided into specific domains based on transcription factor and growth factor expression. We fate mapped Dm neurons and found that more abundant neural types are born from larger neuroepithelial subdomains, while less abundant subtypes are born from smaller ones. Additionally, morphogenetic Dpp/BMP signaling provides a second layer of patterning that subdivides the neuroepithelium into smaller domains to provide more granular control of cell proportions. Apoptosis appears to play a minor role in regulating Dm neuron abundance. This work describes an underappreciated mechanism for the regulation of neuronal stoichiometry.
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Affiliation(s)
- Jennifer A Malin
- Department of Biology, New York University, New York, NY 10003, USA.
| | - Yen-Chung Chen
- Department of Biology, New York University, New York, NY 10003, USA
| | - Félix Simon
- Department of Biology, New York University, New York, NY 10003, USA
| | - Evelyn Keefer
- Department of Biology, New York University, New York, NY 10003, USA
| | - Claude Desplan
- Department of Biology, New York University, New York, NY 10003, USA.
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3
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Zhang Y, Li X. Development of the Drosophila Optic Lobe. Cold Spring Harb Protoc 2024; 2024:108156. [PMID: 37758285 DOI: 10.1101/pdb.top108156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
The Drosophila visual system has been a great model to study fundamental questions in neurobiology, such as neural fate specification, axon guidance, circuit formation, and information processing. The Drosophila visual system is composed of the compound eye and the optic lobe. The optic lobe is divided into four neuropils-namely, the lamina, medulla, lobula, and lobula plate. There are around 200 types of optic lobe neurons, which wire together to form a complex neural structure to processes visual information. These neurons are derived from two neuroepithelial structures-namely, the outer proliferation center (OPC) and the inner proliferation center (IPC), in the larval brain. Recent work on the Drosophila optic lobe has revealed basic principles underlying the development of this complex neural structure, and immunostaining has been a key tool in these studies. Here, we provide a brief overview of the Drosophila optic lobe structure and development, as revealed by immunostaining. First, we introduce the structure of the adult optic lobe. Then, we summarize recent advances in the study of neural fate specification during development of different parts of the optic lobe. Last, we briefly summarize general aspects of axon guidance and neuropil assembly in the optic lobe. With this review, we aim to familiarize readers with this complex neural structure and highlight the power of this great model to study neural development to facilitate further developmental and functional studies using this system.
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Affiliation(s)
- Yu Zhang
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Xin Li
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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Martin M, Gutierrez-Avino F, Shaikh MN, Tejedor FJ. A novel proneural function of Asense is integrated with the sequential actions of Delta-Notch, L'sc and Su(H) to promote the neuroepithelial to neuroblast transition. PLoS Genet 2023; 19:e1010991. [PMID: 37871020 PMCID: PMC10621995 DOI: 10.1371/journal.pgen.1010991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 11/02/2023] [Accepted: 09/20/2023] [Indexed: 10/25/2023] Open
Abstract
In order for neural progenitors (NPs) to generate distinct populations of neurons at the right time and place during CNS development, they must switch from undergoing purely proliferative, self-renewing divisions to neurogenic, asymmetric divisions in a tightly regulated manner. In the developing Drosophila optic lobe, neuroepithelial (NE) cells of the outer proliferation center (OPC) are progressively transformed into neurogenic NPs called neuroblasts (NBs) in a medial to lateral proneural wave. The cells undergoing this transition express Lethal of Scute (L'sc), a proneural transcription factor (TF) of the Acheate Scute Complex (AS-C). Here we show that there is also a peak of expression of Asense (Ase), another AS-C TF, in the cells neighboring those with transient L'sc expression. These peak of Ase cells help to identify a new transitional stage as they have lost NE markers and L'sc, they receive a strong Notch signal and barely exhibit NB markers. This expression of Ase is necessary and sufficient to promote the NE to NB transition in a more robust and rapid manner than that of l'sc gain of function or Notch loss of function. Thus, to our knowledge, these data provide the first direct evidence of a proneural role for Ase in CNS neurogenesis. Strikingly, we found that strong Delta-Notch signaling at the lateral border of the NE triggers l'sc expression, which in turn induces ase expression in the adjacent cells through the activation of Delta-Notch signaling. These results reveal two novel non-conventional actions of Notch signaling in driving the expression of proneural factors, in contrast to the repression that Notch signaling exerts on them during classical lateral inhibition. Finally, Suppressor of Hairless (Su(H)), which seems to be upregulated late in the transitioning cells and in NBs, represses l'sc and ase, ensuring their expression is transient. Thus, our data identify a key proneural role of Ase that is integrated with the sequential activities of Delta-Notch signaling, L'sc, and Su(H), driving the progressive transformation of NE cells into NBs.
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Affiliation(s)
- Mercedes Martin
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernandez, Sant Joan d’Alacant, Spain
| | - Francisco Gutierrez-Avino
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernandez, Sant Joan d’Alacant, Spain
| | - Mirja N. Shaikh
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernandez, Sant Joan d’Alacant, Spain
| | - Francisco J. Tejedor
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernandez, Sant Joan d’Alacant, Spain
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5
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Napoli FR, Daly CM, Neal S, McCulloch KJ, Zaloga AR, Liu A, Koenig KM. Cephalopod retinal development shows vertebrate-like mechanisms of neurogenesis. Curr Biol 2022; 32:5045-5056.e3. [PMID: 36356573 PMCID: PMC9729453 DOI: 10.1016/j.cub.2022.10.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/30/2022] [Accepted: 10/14/2022] [Indexed: 11/10/2022]
Abstract
Coleoid cephalopods, including squid, cuttlefish, and octopus, have large and complex nervous systems and high-acuity, camera-type eyes. These traits are comparable only to features that are independently evolved in the vertebrate lineage. The size of animal nervous systems and the diversity of their constituent cell types is a result of the tight regulation of cellular proliferation and differentiation in development. Changes in the process of development during evolution that result in a diversity of neural cell types and variable nervous system size are not well understood. Here, we have pioneered live-imaging techniques and performed functional interrogation to show that the squid Doryteuthis pealeii utilizes mechanisms during retinal neurogenesis that are hallmarks of vertebrate processes. We find that retinal progenitor cells in the squid undergo nuclear migration until they exit the cell cycle. We identify retinal organization corresponding to progenitor, post-mitotic, and differentiated cells. Finally, we find that Notch signaling may regulate both retinal cell cycle and cell fate. Given the convergent evolution of elaborate visual systems in cephalopods and vertebrates, these results reveal common mechanisms that underlie the growth of highly proliferative neurogenic primordia. This work highlights mechanisms that may alter ontogenetic allometry and contribute to the evolution of complexity and growth in animal nervous systems.
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Affiliation(s)
- Francesca R Napoli
- John Harvard Distinguished Science Fellowship Program, Harvard University, Cambridge, MA 02138, USA; Department of Organismic and Evolutionary Biology, Harvard University, Harvard University, Cambridge, MA 02138, USA
| | - Christina M Daly
- John Harvard Distinguished Science Fellowship Program, Harvard University, Cambridge, MA 02138, USA; Department of Organismic and Evolutionary Biology, Harvard University, Harvard University, Cambridge, MA 02138, USA
| | - Stephanie Neal
- John Harvard Distinguished Science Fellowship Program, Harvard University, Cambridge, MA 02138, USA; Department of Organismic and Evolutionary Biology, Harvard University, Harvard University, Cambridge, MA 02138, USA
| | - Kyle J McCulloch
- John Harvard Distinguished Science Fellowship Program, Harvard University, Cambridge, MA 02138, USA; Department of Organismic and Evolutionary Biology, Harvard University, Harvard University, Cambridge, MA 02138, USA
| | - Alexandra R Zaloga
- John Harvard Distinguished Science Fellowship Program, Harvard University, Cambridge, MA 02138, USA; Department of Organismic and Evolutionary Biology, Harvard University, Harvard University, Cambridge, MA 02138, USA
| | - Alicia Liu
- John Harvard Distinguished Science Fellowship Program, Harvard University, Cambridge, MA 02138, USA; Department of Organismic and Evolutionary Biology, Harvard University, Harvard University, Cambridge, MA 02138, USA
| | - Kristen M Koenig
- John Harvard Distinguished Science Fellowship Program, Harvard University, Cambridge, MA 02138, USA; Department of Organismic and Evolutionary Biology, Harvard University, Harvard University, Cambridge, MA 02138, USA.
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Valentino P, Erclik T. Spalt and disco define the dorsal-ventral neuroepithelial compartments of the developing Drosophila medulla. Genetics 2022; 222:iyac145. [PMID: 36135799 PMCID: PMC9630984 DOI: 10.1093/genetics/iyac145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 09/14/2022] [Indexed: 11/14/2022] Open
Abstract
Spatial patterning of neural stem cell populations is a powerful mechanism by which to generate neuronal diversity. In the developing Drosophila medulla, the symmetrically dividing neuroepithelial cells of the outer proliferation center crescent are spatially patterned by the nonoverlapping expression of 3 transcription factors: Vsx1 in the center, Optix in the adjacent arms, and Rx in the tips. These spatial genes compartmentalize the outer proliferation center and, together with the temporal patterning of neuroblasts, act to diversify medulla neuronal fates. The observation that the dorsal and ventral halves of the outer proliferation center also grow as distinct compartments, together with the fact that a subset of neuronal types is generated from only one half of the crescent, suggests that additional transcription factors spatially pattern the outer proliferation center along the dorsal-ventral axis. Here, we identify the spalt (salm and salr) and disco (disco and disco-r) genes as the dorsal-ventral patterning transcription factors of the outer proliferation center. Spalt and Disco are differentially expressed in the dorsal and ventral outer proliferation center from the embryo through to the third instar larva, where they cross-repress each other to form a sharp dorsal-ventral boundary. We show that hedgehog is necessary for Disco expression in the embryonic optic placode and that disco is subsequently required for the development of the ventral outer proliferation center and its neuronal progeny. We further demonstrate that this dorsal-ventral patterning axis acts independently of Vsx1-Optix-Rx and thus propose that Spalt and Disco represent a third outer proliferation center patterning axis that may act to further diversify medulla fates.
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Affiliation(s)
- Priscilla Valentino
- Department of Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Ted Erclik
- Department of Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 1A1, Canada
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7
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Hildebrandt K, Klöppel C, Gogel J, Hartenstein V, Walldorf U. Orthopedia expression during Drosophila melanogaster nervous system development and its regulation by microRNA-252. Dev Biol 2022; 492:87-100. [PMID: 36179878 DOI: 10.1016/j.ydbio.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/05/2022] [Accepted: 09/19/2022] [Indexed: 11/03/2022]
Abstract
During brain development of Drosophila melanogaster many transcription factors are involved in regulating neural fate and morphogenesis. In our study we show that the transcription factor Orthopedia (Otp), a member of the 57B homeobox gene cluster, plays an important role in this process. Otp is expressed in a stable pattern in defined lineages from mid-embryonic stages into the adult brain and therefore a very stable marker for these lineages. We determined the abundance of the two different otp transcripts in the brain and hindgut during development using qPCR. CRISPR/Cas9 generated otp mutants of the longer protein form significantly affect the expression of Otp in specific areas. We generated an otp enhancer trap strain by gene targeting and reintegration of Gal4, which mimics the complete expression of otp during development except the embryonic hindgut expression. Since in the embryo, the expression of Otp is posttranscriptionally regulated, we looked for putative miRNAs interacting with the otp 3'UTR, and identified microRNA-252 as a candidate. Further analyses with mutated and deleted forms of the microRNA-252 interacting sequence in the otp 3'UTR demonstrate an in vivo interaction of microRNA-252 with the otp 3'UTR. An effect of this interaction is seen in the adult brain, where Otp expression is partially abolished in a knockout strain of microRNA-252. Our results show that Otp is another important factor for brain development in Drosophila melanogaster.
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Affiliation(s)
- Kirsten Hildebrandt
- Developmental Biology, Saarland University, Building 61, 66421, Homburg, Saar, Germany
| | - Christine Klöppel
- Developmental Biology, Saarland University, Building 61, 66421, Homburg, Saar, Germany
| | - Jasmin Gogel
- Developmental Biology, Saarland University, Building 61, 66421, Homburg, Saar, Germany
| | - Volker Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, CA, 90095, USA
| | - Uwe Walldorf
- Developmental Biology, Saarland University, Building 61, 66421, Homburg, Saar, Germany.
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8
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Nguyen PK, Cheng LY. Non-autonomous regulation of neurogenesis by extrinsic cues: a Drosophila perspective. OXFORD OPEN NEUROSCIENCE 2022; 1:kvac004. [PMID: 38596708 PMCID: PMC10913833 DOI: 10.1093/oons/kvac004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/20/2022] [Accepted: 03/23/2022] [Indexed: 04/11/2024]
Abstract
The formation of a functional circuitry in the central nervous system (CNS) requires the correct number and subtypes of neural cells. In the developing brain, neural stem cells (NSCs) self-renew while giving rise to progenitors that in turn generate differentiated progeny. As such, the size and the diversity of cells that make up the functional CNS depend on the proliferative properties of NSCs. In the fruit fly Drosophila, where the process of neurogenesis has been extensively investigated, extrinsic factors such as the microenvironment of NSCs, nutrients, oxygen levels and systemic signals have been identified as regulators of NSC proliferation. Here, we review decades of work that explores how extrinsic signals non-autonomously regulate key NSC characteristics such as quiescence, proliferation and termination in the fly.
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Affiliation(s)
- Phuong-Khanh Nguyen
- Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
- Department of Anatomy and Physiology, The University of Melbourne, Victoria 3010, Australia
| | - Louise Y Cheng
- Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Victoria 3010, Australia
- Department of Anatomy and Physiology, The University of Melbourne, Victoria 3010, Australia
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Zhu H, Zhao SD, Ray A, Zhang Y, Li X. A comprehensive temporal patterning gene network in Drosophila medulla neuroblasts revealed by single-cell RNA sequencing. Nat Commun 2022; 13:1247. [PMID: 35273186 PMCID: PMC8913700 DOI: 10.1038/s41467-022-28915-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 02/12/2022] [Indexed: 12/24/2022] Open
Abstract
During development, neural progenitors are temporally patterned to sequentially generate a variety of neural types. In Drosophila neural progenitors called neuroblasts, temporal patterning is regulated by cascades of Temporal Transcription Factors (TTFs). However, known TTFs were mostly identified through candidate approaches and may not be complete. In addition, many fundamental questions remain concerning the TTF cascade initiation, progression, and termination. In this work, we use single-cell RNA sequencing of Drosophila medulla neuroblasts of all ages to identify a list of previously unknown TTFs, and experimentally characterize their roles in temporal patterning and neuronal specification. Our study reveals a comprehensive temporal gene network that patterns medulla neuroblasts from start to end. Furthermore, the speed of the cascade progression is regulated by Lola transcription factors expressed in all medulla neuroblasts. Our comprehensive study of the medulla neuroblast temporal cascade illustrates mechanisms that may be conserved in the temporal patterning of neural progenitors. During development, neural progenitors generate a variety of neural types sequentially. Here the authors examine gene expression patterns in Drosophila neural progenitors at single-cell level, and identify a gene regulatory network controlling the sequential generation of different neural types.
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Affiliation(s)
- Hailun Zhu
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Sihai Dave Zhao
- Department of Statistics, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Alokananda Ray
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Yu Zhang
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Xin Li
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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Hildebrandt K, Kolb D, Klöppel C, Kaspar P, Wittling F, Hartwig O, Federspiel J, Findji I, Walldorf U. Regulatory modules mediating the complex neural expression patterns of the homeobrain gene during Drosophila brain development. Hereditas 2022; 159:2. [PMID: 34983686 PMCID: PMC8728971 DOI: 10.1186/s41065-021-00218-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 12/10/2021] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND The homeobox gene homeobrain (hbn) is located in the 57B region together with two other homeobox genes, Drosophila Retinal homeobox (DRx) and orthopedia (otp). All three genes encode transcription factors with important functions in brain development. Hbn mutants are embryonic lethal and characterized by a reduction in the anterior protocerebrum, including the mushroom bodies, and a loss of the supraoesophageal brain commissure. RESULTS In this study we conducted a detailed expression analysis of Hbn in later developmental stages. In the larval brain, Hbn is expressed in all type II lineages and the optic lobes, including the medulla and lobula plug. The gene is expressed in the cortex of the medulla and the lobula rim in the adult brain. We generated a new hbnKOGal4 enhancer trap strain by reintegrating Gal4 in the hbn locus through gene targeting, which reflects the complete hbn expression during development. Eight different enhancer-Gal4 strains covering 12 kb upstream of hbn, the two large introns and 5 kb downstream of the gene, were established and hbn expression was investigated. We characterized several enhancers that drive expression in specific areas of the brain throughout development, from embryo to the adulthood. Finally, we generated deletions of four of these enhancer regions through gene targeting and analysed their effects on the expression and function of hbn. CONCLUSION The complex expression of Hbn in the developing brain is regulated by several specific enhancers within the hbn locus. Each enhancer fragment drives hbn expression in several specific cell lineages, and with largely overlapping patterns, suggesting the presence of shadow enhancers and enhancer redundancy. Specific enhancer deletion strains generated by gene targeting display developmental defects in the brain. This analysis opens an avenue for a deeper analysis of hbn regulatory elements in the future.
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Affiliation(s)
- Kirsten Hildebrandt
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
| | - Dieter Kolb
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
| | - Christine Klöppel
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
| | - Petra Kaspar
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
- Present address: COS Heidelberg, University of Heidelberg, Im Neuenheimer Feld 230, 69120, Heidelberg, Germany
| | - Fabienne Wittling
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
- Present address: Hemholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, Building E8.1, 66123, Saarbrücken, Germany
| | - Olga Hartwig
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
- Present address: Hemholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, Building E8.1, 66123, Saarbrücken, Germany
| | - Jannic Federspiel
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
| | - India Findji
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
| | - Uwe Walldorf
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany.
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11
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Guo N, McDermott KD, Shih YT, Zanga H, Ghosh D, Herber C, Meara WR, Coleman J, Zagouras A, Wong LP, Sadreyev R, Gonçalves JT, Sahay A. Transcriptional regulation of neural stem cell expansion in the adult hippocampus. eLife 2022; 11:72195. [PMID: 34982030 PMCID: PMC8820733 DOI: 10.7554/elife.72195] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 01/03/2022] [Indexed: 12/11/2022] Open
Abstract
Experience governs neurogenesis from radial-glial neural stem cells (RGLs) in the adult hippocampus to support memory. Transcription factors (TFs) in RGLs integrate physiological signals to dictate self-renewal division mode. Whereas asymmetric RGL divisions drive neurogenesis during favorable conditions, symmetric divisions prevent premature neurogenesis while amplifying RGLs to anticipate future neurogenic demands. The identities of TFs regulating RGL symmetric self-renewal, unlike those that regulate RGL asymmetric self-renewal, are not known. Here, we show in mice that the TF Kruppel-like factor 9 (Klf9) is elevated in quiescent RGLs and inducible, deletion of Klf9 promotes RGL activation state. Clonal analysis and longitudinal intravital two-photon imaging directly demonstrate that Klf9 functions as a brake on RGL symmetric self-renewal. In vivo translational profiling of RGLs lacking Klf9 generated a molecular blueprint for RGL symmetric self-renewal that was characterized by upregulation of genetic programs underlying Notch and mitogen signaling, cell cycle, fatty acid oxidation, and lipogenesis. Together, these observations identify Klf9 as a transcriptional regulator of neural stem cell expansion in the adult hippocampus. In humans and other mammals, a region of the brain known as the hippocampus plays important roles in memory. New experiences guide cells in the hippocampus known as radial-glial neural stem cells (RGLs) to divide to make new neurons and other types of cells involved in forming memories. Each time an RGL divides, it can choose to divide asymmetrically to maintain a copy of itself and make a new cell of another type, or divide symmetrically (a process known as symmetric self-renewal) to produce two RGLs. Symmetric self-renewal helps to restore and replenish the pool of stem cells in the hippocampus that are lost due to injury or age, allowing us to continue making new neurons. Proteins known as transcription factors are believed to control how RGLs divide. Previous studies have identified several transcription factors that regulate the RGLs splitting asymmetrically to make neurons and other cells. But the identities of the transcription factors that regulate symmetric self-renewal in the adult hippocampus have remained elusive. Here, Guo et al. searched for transcription factors that regulate symmetric self-renewal of RGLs in mice. The experiments found that RGLs that are resting and not dividing (referred to as ‘quiescent’) have higher levels of a transcription factor called Klf9 than RGLs that are actively dividing. Loss of the gene encoding Klf9 triggered quiescent RGLs to start dividing, and further experiments showed that Klf9 directly inhibited symmetric self-renewal. Guo et al. then used an approach called in vivo translational profiling to generate a blueprint that revealed new insights into the molecular processes involved in this symmetric division. These findings pave the way for researchers to develop strategies that may expand the numbers of stem cells in the hippocampus. This could eventually be used to help replenish brain circuits with neurons and improve the memory of individuals with Alzheimer’s disease or other conditions that cause memory loss.
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Affiliation(s)
- Nannan Guo
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, United States.,Harvard Stem Cell Institute, Cambridge, United States.,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, United States.,BROAD Institute of Harvard and MIT, Cambridge, United States
| | - Kelsey D McDermott
- Ruth L. and David S. Gottesman Institute for Stem Cell Biology and Regenerative Medicine; Dominick Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, United States
| | - Yu-Tzu Shih
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, United States.,Harvard Stem Cell Institute, Cambridge, United States.,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, United States.,BROAD Institute of Harvard and MIT, Cambridge, United States
| | - Haley Zanga
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, United States.,Harvard Stem Cell Institute, Cambridge, United States.,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, United States.,BROAD Institute of Harvard and MIT, Cambridge, United States
| | - Debolina Ghosh
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, United States.,Harvard Stem Cell Institute, Cambridge, United States
| | - Charlotte Herber
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, United States.,Harvard Stem Cell Institute, Cambridge, United States
| | - William R Meara
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, United States.,Harvard Stem Cell Institute, Cambridge, United States
| | - James Coleman
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, United States.,Harvard Stem Cell Institute, Cambridge, United States
| | - Alexia Zagouras
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, United States.,Harvard Stem Cell Institute, Cambridge, United States
| | - Lai Ping Wong
- Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, United States
| | - Ruslan Sadreyev
- Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, United States
| | - J Tiago Gonçalves
- Ruth L. and David S. Gottesman Institute for Stem Cell Biology and Regenerative Medicine; Dominick Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, United States
| | - Amar Sahay
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, United States.,Harvard Stem Cell Institute, Cambridge, United States.,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, United States.,BROAD Institute of Harvard and MIT, Cambridge, United States
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12
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Klöppel C, Hildebrandt K, Kolb D, Fürst N, Bley I, Karlowatz RJ, Walldorf U. Functional analysis of enhancer elements regulating the expression of the Drosophila homeodomain transcription factor DRx by gene targeting. Hereditas 2021; 158:42. [PMID: 34736520 PMCID: PMC8569992 DOI: 10.1186/s41065-021-00210-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 10/18/2021] [Indexed: 11/17/2022] Open
Abstract
Background The Drosophila brain is an ideal model system to study stem cells, here called neuroblasts, and the generation of neural lineages. Many transcriptional activators are involved in formation of the brain during the development of Drosophila melanogaster. The transcription factor Drosophila Retinal homeobox (DRx), a member of the 57B homeobox gene cluster, is also one of these factors for brain development. Results In this study a detailed expression analysis of DRx in different developmental stages was conducted. We show that DRx is expressed in the embryonic brain in the protocerebrum, in the larval brain in the DM and DL lineages, the medulla and the lobula complex and in the central complex of the adult brain. We generated a DRx enhancer trap strain by gene targeting and reintegration of Gal4, which mimics the endogenous expression of DRx. With the help of eight existing enhancer-Gal4 strains and one made by our group, we mapped various enhancers necessary for the expression of DRx during all stages of brain development from the embryo to the adult. We made an analysis of some larger enhancer regions by gene targeting. Deletion of three of these enhancers showing the most prominent expression patterns in the brain resulted in specific temporal and spatial loss of DRx expression in defined brain structures. Conclusion Our data show that DRx is expressed in specific neuroblasts and defined neural lineages and suggest that DRx is another important factor for Drosophila brain development. Supplementary Information The online version contains supplementary material available at 10.1186/s41065-021-00210-z.
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Affiliation(s)
- Christine Klöppel
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
| | - Kirsten Hildebrandt
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
| | - Dieter Kolb
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
| | - Nora Fürst
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany.,Present address: Genetics/Epigenetics, Saarland University, Building A2.4, 66123, Saarbrücken, Germany
| | - Isabelle Bley
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany.,Present address: Research Institute Children's Cancer Center Hamburg, Building N63, Martinistr. 52, 20251, Hamburg, Germany
| | | | - Uwe Walldorf
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany.
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13
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Hildebrandt K, Kübel S, Minet M, Fürst N, Klöppel C, Steinmetz E, Walldorf U. Enhancer analysis of the Drosophila zinc finger transcription factor Earmuff by gene targeting. Hereditas 2021; 158:41. [PMID: 34732265 PMCID: PMC8567707 DOI: 10.1186/s41065-021-00209-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 10/08/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Many transcription factors are involved in the formation of the brain during the development of Drosophila melanogaster. The transcription factor Earmuff (Erm), a member of the forebrain embryonic zinc finger family (Fezf), is one of these important factors for brain development. One major function of Earmuff is the regulation of proliferation within type II neuroblast lineages in the brain; here, Earmuff is expressed in intermediate neural progenitor cells (INPs) and balances neuronal differentiation versus stem cell maintenance. Erm expression during development is regulated by several enhancers. RESULTS In this work we show a functional analysis of erm and some of its enhancers. We generated a new erm mutant allele by gene targeting and reintegrated Gal4 to make an erm enhancer trap strain that could also be used on an erm mutant background. The deletion of three of the previously analysed enhancers showing the most prominent expression patterns of erm by gene targeting resulted in specific temporal and spatial defects in defined brain structures. These defects were already known but here could be assigned to specific enhancer regions. CONCLUSION This analysis is to our knowledge the first systematic analysis of several large enhancer deletions of a Drosophila gene by gene targeting and will enable deeper analysis of erm enhancer functions in the future.
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Affiliation(s)
- Kirsten Hildebrandt
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
| | - Sabrina Kübel
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
- Present address: Clinical and Molecular Virology, Friedrich-Alexander University, 91054, Erlangen, Germany
| | - Marie Minet
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
- Present address: Human Genetics, Saarland University, Building 60, 66421, Homburg/Saar, Germany
| | - Nora Fürst
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
- Present address: Genetics/Epigenetics, Saarland University, Building A2.4, 66123, Saarbrücken, Germany
| | - Christine Klöppel
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
| | - Eva Steinmetz
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany
- Present address: Zoology and Physiology, Saarland University, Building B2.1, 66123, Saarbrücken, Germany
| | - Uwe Walldorf
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany.
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14
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Abstract
Notch signalling is a well-conserved signalling pathway that regulates cell fate through cell-cell communication. A typical feature of Notch signalling is ‘lateral inhibition’, whereby two neighbouring cells of equivalent state of differentiation acquire different cell fates. Recently, mathematical and computational approaches have addressed the Notch dynamics in Drosophila neural development. Typical examples of lateral inhibition are observed in the specification of neural stem cells in the embryo and sensory organ precursors in the thorax. In eye disc development, Notch signalling cooperates with other signalling pathways to define the evenly spaced positioning of the photoreceptor cells. The interplay between Notch and epidermal growth factor receptor signalling regulates the timing of neural stem cell differentiation in the optic lobe. In this review, we summarize the theoretical studies that have been conducted to elucidate the Notch dynamics in these systems and discuss the advantages of combining mathematical models with biological experiments.
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Affiliation(s)
- Tetsuo Yasugi
- Mathematical Neuroscience Unit, Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Makoto Sato
- Mathematical Neuroscience Unit, Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa, Japan.,Laboratory of Developmental Neurobiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
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15
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Hoffmann N, Peters J. Functions of the (pro)renin receptor (Atp6ap2) at molecular and system levels: pathological implications in hypertension, renal and brain development, inflammation, and fibrosis. Pharmacol Res 2021; 173:105922. [PMID: 34607004 DOI: 10.1016/j.phrs.2021.105922] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 09/16/2021] [Accepted: 09/29/2021] [Indexed: 12/13/2022]
Abstract
The (pro)renin receptor [(P)RR, Atp6ap2] was initially discovered as a membrane-bound binding partner of prorenin and renin. A soluble (P)RR has additional paracrine effects and is involved in metabolic syndrome and kidney damage. Meanwhile it is clear that most of the effects of the (P)RR are independent of prorenin. In the kidney, (P)RR plays an important role in renal dysfunction by activating proinflammatory and profibrotic molecules. In the brain, (P)RR is expressed in cardiovascular regulatory nuclei and is linked to hypertension. (P)RR is known to be an essential component of the v-ATPase as a key accessory protein and plays an important role in kidney, brain and heart via regulating the pH of the extracellular space and intracellular compartments. V-ATPase and (P)RR together act on WNT and mTOR signalling pathways, which are responsible for cellular homeostasis and autophagy. (P)RR through its role in v-ATPase assembly and function is also important for fast recycling endocytosis by megalin. In the kidney, megalin together with v-ATPase and (P)RR is crucial for endocytic uptake of components of the RAS and their intracellular processing. In the brain, (P)RR, v-ATPases and megalin are important regulators both during development and in the adult. All three proteins are associated with diseases such as XLMR, XMRE, X-linked parkinsonism and epilepsy, cognitive disorders with Parkinsonism, spasticity, intellectual disability, and Alzheimer's Disease which are characterized by impaired neuronal function and/or neuronal loss. The present review focusses on the relevant effects of Atp6ap2 without assigning them necessarily to the RAS. Mechanistically, many effects can be well explained by the role of Atp6ap2 for v-ATPase assembly and function. Furthermore, application of a soluble (P)RR analogue as new therapeutic option is discussed.
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Affiliation(s)
- Nadin Hoffmann
- Institute of Physiology, University Medicine Greifswald, Friedrich-Ludwig-Jahn-Str. 15A, 17475, Greifswald, Germany
| | - Jörg Peters
- Institute of Physiology, University Medicine Greifswald, Friedrich-Ludwig-Jahn-Str. 15A, 17475, Greifswald, Germany.
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16
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Biembengut ÍV, Silva ILZ, Souza TDACBD, Shigunov P. Cytoplasmic FMR1 interacting protein (CYFIP) family members and their function in neural development and disorders. Mol Biol Rep 2021; 48:6131-6143. [PMID: 34327661 DOI: 10.1007/s11033-021-06585-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/20/2021] [Indexed: 11/25/2022]
Abstract
In humans, the cytoplasmic FMR1 interacting protein (CYFIP) family is composed of CYFIP1 and CYFIP2. Despite their high similarity and shared interaction with many partners, CYFIP1 and CYFIP2 act at different points in cellular processes. CYFIP1 and CYFIP2 have different expression levels in human tissues, and knockout animals die at different time points of development. CYFIP1, similar to CYFIP2, acts in the WAVE regulatory complex (WRC) and plays a role in actin dynamics through the activation of the Arp2/3 complex and in a posttranscriptional regulatory complex with the fragile X mental retardation protein (FMRP). Previous reports have shown that CYFIP1 and CYFIP2 may play roles in posttranscriptional regulation in different ways. While CYFIP1 is involved in translation initiation via the 5'UTR, CYFIP2 may regulate mRNA expression via the 3'UTR. In addition, this CYFIP protein family is involved in neural development and maturation as well as in different neural disorders, such as intellectual disabilities, autistic spectrum disorders, and Alzheimer's disease. In this review, we map diverse studies regarding the functions, regulation, and implications of CYFIP proteins in a series of molecular pathways. We also highlight mutations and their structural effects both in functional studies and in neural diseases.
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Affiliation(s)
- Ísis Venturi Biembengut
- Carlos Chagas Institute-FIOCRUZ-PR, Rua Prof. Algacyr Munhoz Mader, 3775, CIC, Curitiba, Paraná, 81830-010, Brazil
| | | | | | - Patrícia Shigunov
- Carlos Chagas Institute-FIOCRUZ-PR, Rua Prof. Algacyr Munhoz Mader, 3775, CIC, Curitiba, Paraná, 81830-010, Brazil.
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17
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Giri A, Sengupta D, Kar S. Deciphering the Role of Fluctuation Dependent Intercellular Communication in Neural Stem Cell Development. ACS Chem Neurosci 2021; 12:2360-2372. [PMID: 34170103 DOI: 10.1021/acschemneuro.1c00116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Neural stem cells (NPCs) efficiently communicate in an intercellular manner to govern specific cell fate decisions during the developmental process despite withstanding the fluctuating cellular environment. How these fluctuations from diverse origins functionally affect the precise cell fate decision making remains elusive. By taking a stochastic mathematical modeling approach, we unravel that the transcriptional variability arising within an NPC population due to intermittent cell cycle events significantly influences the neuron to NPC ratio during development. Our model proficiently quantifies the impact of different sources of heterogeneities in maintaining an exact neuron to NPC ratio and predicts plausible experimental ways to fine-tune the development of NPCs. In the future, these modeling insights may lead to better therapeutic avenues to regenerate neurons from NPCs.
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Affiliation(s)
- Amitava Giri
- Department of Chemistry, IIT Bombay, Powai, Mumbai 400076, India
| | - Dola Sengupta
- Department of Chemistry, Techno India University, Salt Lake, Kolkata 700091, India
| | - Sandip Kar
- Department of Chemistry, IIT Bombay, Powai, Mumbai 400076, India
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18
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Neural specification, targeting, and circuit formation during visual system assembly. Proc Natl Acad Sci U S A 2021; 118:2101823118. [PMID: 34183440 DOI: 10.1073/pnas.2101823118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Like other sensory systems, the visual system is topographically organized: Its sensory neurons, the photoreceptors, and their targets maintain point-to-point correspondence in physical space, forming a retinotopic map. The iterative wiring of circuits in the visual system conveniently facilitates the study of its development. Over the past few decades, experiments in Drosophila have shed light on the principles that guide the specification and connectivity of visual system neurons. In this review, we describe the main findings unearthed by the study of the Drosophila visual system and compare them with similar events in mammals. We focus on how temporal and spatial patterning generates diverse cell types, how guidance molecules distribute the axons and dendrites of neurons within the correct target regions, how vertebrates and invertebrates generate their retinotopic map, and the molecules and mechanisms required for neuronal migration. We suggest that basic principles used to wire the fly visual system are broadly applicable to other systems and highlight its importance as a model to study nervous system development.
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19
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Abstract
AbstractIn the developing Drosophila CNS, two pools of neural stem cells, the symmetrically dividing progenitors in the neuroepithelium (NE) and the asymmetrically dividing neuroblasts (NBs) generate the majority of the neurons that make up the adult central nervous system (CNS). The generation of a correct sized brain depends on maintaining the fine balance between neural stem cell self-renewal and differentiation, which are regulated by cell-intrinsic and cell-extrinsic cues. In this review, we will discuss our current understanding of how self-renewal and differentiation are regulated in the two neural stem cell pools, and the consequences of the deregulation of these processes.
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Affiliation(s)
- Francesca Froldi
- Peter MacCallum Cancer Centre, East Melbourne, Victoria, 3002, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Victoria, 3010, Australia
| | - Milán Szuperák
- Peter MacCallum Cancer Centre, East Melbourne, Victoria, 3002, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Victoria, 3010, Australia
| | - Louise Y. Cheng
- Peter MacCallum Cancer Centre, East Melbourne, Victoria, 3002, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Victoria, 3010, Australia
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20
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Krishnan M, Kumar S, Kangale LJ, Ghigo E, Abnave P. The Act of Controlling Adult Stem Cell Dynamics: Insights from Animal Models. Biomolecules 2021; 11:biom11050667. [PMID: 33946143 PMCID: PMC8144950 DOI: 10.3390/biom11050667] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 04/02/2021] [Accepted: 04/09/2021] [Indexed: 12/12/2022] Open
Abstract
Adult stem cells (ASCs) are the undifferentiated cells that possess self-renewal and differentiation abilities. They are present in all major organ systems of the body and are uniquely reserved there during development for tissue maintenance during homeostasis, injury, and infection. They do so by promptly modulating the dynamics of proliferation, differentiation, survival, and migration. Any imbalance in these processes may result in regeneration failure or developing cancer. Hence, the dynamics of these various behaviors of ASCs need to always be precisely controlled. Several genetic and epigenetic factors have been demonstrated to be involved in tightly regulating the proliferation, differentiation, and self-renewal of ASCs. Understanding these mechanisms is of great importance, given the role of stem cells in regenerative medicine. Investigations on various animal models have played a significant part in enriching our knowledge and giving In Vivo in-sight into such ASCs regulatory mechanisms. In this review, we have discussed the recent In Vivo studies demonstrating the role of various genetic factors in regulating dynamics of different ASCs viz. intestinal stem cells (ISCs), neural stem cells (NSCs), hematopoietic stem cells (HSCs), and epidermal stem cells (Ep-SCs).
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Affiliation(s)
- Meera Krishnan
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Gurgaon-Faridabad Ex-pressway, Faridabad 121001, India; (M.K.); (S.K.)
| | - Sahil Kumar
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Gurgaon-Faridabad Ex-pressway, Faridabad 121001, India; (M.K.); (S.K.)
| | - Luis Johnson Kangale
- IRD, AP-HM, SSA, VITROME, Aix-Marseille University, 13385 Marseille, France;
- Institut Hospitalo Universitaire Méditerranée Infection, 13385 Marseille, France;
| | - Eric Ghigo
- Institut Hospitalo Universitaire Méditerranée Infection, 13385 Marseille, France;
- TechnoJouvence, 13385 Marseille, France
| | - Prasad Abnave
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Gurgaon-Faridabad Ex-pressway, Faridabad 121001, India; (M.K.); (S.K.)
- Correspondence:
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21
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Chen M, Lu C, Lu H, Zhang J, Qin D, Liu S, Li X, Zhang L. Farnesoid X receptor via Notch1 directs asymmetric cell division of Sox9 + cells to prevent the development of liver cancer in a mouse model. Stem Cell Res Ther 2021; 12:232. [PMID: 33845903 PMCID: PMC8042944 DOI: 10.1186/s13287-021-02298-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 03/18/2021] [Indexed: 12/21/2022] Open
Abstract
Background Asymmetrical cell division (ACD) maintains the proper number of stem cells to ensure self-renewal. The rate of symmetric division increases as more cancer stem cells (CSCs) become malignant; however, the signaling pathway network involved in CSC division remains elusive. FXR (Farnesoid X receptor), a ligand-activated transcription factor, has several anti-tumor effects and has been shown to target CSCs. Here, we aimed at evaluating the role of FXR in the regulation of the cell division of CSCs. Methods The FXR target gene and downstream molecular mechanisms were confirmed by qRT-PCR, Western blot, luciferase reporter assay, EMAS, Chip, and IF analyses. Pulse-chase BrdU labeling and paired-cell experiments were used to detect the cell division of liver CSCs. Gain- and loss-of-function experiments in Huh7 cells and mouse models were performed to support findings and elucidate the function and underlying mechanisms of FXR-Notch1 in liver CSC division. Results We demonstrated that activation of Notch1 was significantly elevated in the livers of hepatocellular carcinoma (HCC) in Farnesoid X receptor-knockout (FXR-KO) mice and that FXR expression negatively correlated with Notch1 level during chronic liver injury. Activation of FXR induced the asymmetric divisions of Sox9+ liver CSCs and ameliorated liver injury. Mechanistically, FXR directs Sox9+ liver CSCs from symmetry to asymmetry via inhibition of Notch1 expression and activity. Deletion of FXR signaling or over-expression of Notch1 greatly increased Notch1 expression and activity along with ACD reduction. FXR inhibited Notch1 expression by directly binding to its promoter FXRE. FXR also positively regulated Numb expression, contributing to a feedback circuit, which decreased Notch1 activity and directed ACD. Conclusion Our findings suggest that FXR represses Notch1 expression and directs ACD of Sox9+ cells to prevent the development of liver cancer. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-021-02298-6.
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Affiliation(s)
- Mi Chen
- College of Veterinary Medicine/College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China
| | - Chenxia Lu
- The Clinical Medical College of Traditional Chinese Medicine, Hubei University of Chinese Medicine, Wuhan, 430065, China
| | - Hanwen Lu
- College of Veterinary Medicine/College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China
| | - Junyi Zhang
- College of Veterinary Medicine/College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China
| | - Dan Qin
- College of Veterinary Medicine/College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shenghui Liu
- College of Veterinary Medicine/College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiaodong Li
- Hubei Provincial Hospital of TCM, Hubei Provincial Academy of TCM, Wuhan, 430061, China
| | - Lisheng Zhang
- College of Veterinary Medicine/College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China.
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22
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Shard C, Luna-Escalante J, Schweisguth F. Tissue-wide coordination of epithelium-to-neural stem cell transition in the Drosophila optic lobe requires Neuralized. J Cell Biol 2021; 219:152101. [PMID: 32946560 PMCID: PMC7594497 DOI: 10.1083/jcb.202005035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/06/2020] [Accepted: 08/17/2020] [Indexed: 12/15/2022] Open
Abstract
Many tissues are produced by specialized progenitor cells emanating from epithelia via epithelial-to-mesenchymal transition (EMT). Most studies have so far focused on EMT involving single or isolated groups of cells. Here we describe an EMT-like process that requires tissue-level coordination. This EMT-like process occurs along a continuous front in the Drosophila optic lobe neuroepithelium to produce neural stem cells (NSCs). We find that emerging NSCs remain epithelial and apically constrict before dividing asymmetrically to produce neurons. Apical constriction is associated with contractile myosin pulses and involves RhoGEF3 and down-regulation of the Crumbs complex by the E3 ubiquitin ligase Neuralized. Anisotropy in Crumbs complex levels also results in accumulation of junctional myosin. Disrupting the regulation of Crumbs by Neuralized lowered junctional myosin and led to imprecision in the integration of emerging NSCs into the front. Thus, Neuralized promotes smooth progression of the differentiation front by coupling epithelium remodeling at the tissue level with NSC fate acquisition.
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Affiliation(s)
- Chloé Shard
- Institut Pasteur, Paris, France.,UMR3738, Centre National de la Recherche Scientifique, Paris, France
| | - Juan Luna-Escalante
- Institut Pasteur, Paris, France.,UMR3738, Centre National de la Recherche Scientifique, Paris, France.,Laboratoire de Physique, Ecole Normale Supérieure, Centre National de la Recherche Scientifique, Sorbonne Université, Université Paris Diderot, Paris, France
| | - François Schweisguth
- Institut Pasteur, Paris, France.,UMR3738, Centre National de la Recherche Scientifique, Paris, France
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23
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Lago-Baldaia I, Fernandes VM, Ackerman SD. More Than Mortar: Glia as Architects of Nervous System Development and Disease. Front Cell Dev Biol 2020; 8:611269. [PMID: 33381506 PMCID: PMC7767919 DOI: 10.3389/fcell.2020.611269] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 11/17/2020] [Indexed: 12/12/2022] Open
Abstract
Glial cells are an essential component of the nervous system of vertebrates and invertebrates. In the human brain, glia are as numerous as neurons, yet the importance of glia to nearly every aspect of nervous system development has only been expounded over the last several decades. Glia are now known to regulate neural specification, synaptogenesis, synapse function, and even broad circuit function. Given their ubiquity, it is not surprising that the contribution of glia to neuronal disease pathogenesis is a growing area of research. In this review, we will summarize the accumulated evidence of glial participation in several distinct phases of nervous system development and organization-neural specification, circuit wiring, and circuit function. Finally, we will highlight how these early developmental roles of glia contribute to nervous system dysfunction in neurodevelopmental and neurodegenerative disorders.
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Affiliation(s)
- Inês Lago-Baldaia
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Vilaiwan M. Fernandes
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Sarah D. Ackerman
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR, United States
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24
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LNX1 Modulates Notch1 Signaling to Promote Expansion of the Glioma Stem Cell Population during Temozolomide Therapy in Glioblastoma. Cancers (Basel) 2020; 12:cancers12123505. [PMID: 33255632 PMCID: PMC7759984 DOI: 10.3390/cancers12123505] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/05/2020] [Accepted: 10/12/2020] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Glioblastoma is the most common adult malignant brain tumor. It is an aggressive tumor that returns even after surgical removal and temozolomide-based chemotherapy and radiation. Our goal was to understand what genes are altered by temozolomide and how those genes may contribute to tumor return. Our work shows that one of the genes altered is LNX1, which increases the expression of Notch1, a gene important for glioblastoma progression. We further showed that the elevation of LNX1 and Notch1 results in an increase in the tumor stem cell population, a subpopulation of cells thought to help propagate a more aggressive tumor. Finally, we showed that forced reduction in LNX1 expression results in increased survival of animals implanted with glioblastoma. Together, these results suggest that LNX1 may be a novel therapeutic target that would allow modulation of Notch1 activity and the stem cell population, potentially resulting in increased patient survival. Abstract Glioblastoma (GBM) is the most common primary brain malignancy in adults, with a 100% recurrence rate and 21-month median survival. Our lab and others have shown that GBM contains a subpopulation of glioma stem cells (GSCs) that expand during chemotherapy and may contribute to therapeutic resistance and recurrence in GBM. To investigate the mechanism behind this expansion, we applied gene set expression analysis (GSEA) to patient-derived xenograft (PDX) cells in response to temozolomide (TMZ), the most commonly used chemotherapy against GBM. Results showed significant enrichment of cancer stem cell and cell cycle pathways (False Discovery Rate (FDR) < 0.25). The ligand of numb protein 1 (LNX1), a known regulator of Notch signaling by targeting negative regulator Numb, is strongly upregulated after TMZ therapy (p < 0.0001) and is negatively correlated with survival of GBM patients. LNX1 is also upregulated after TMZ therapy in multiple PDX lines with concomitant downregulations in Numb and upregulations in intracellular Notch1 (NICD). Overexpression of LNX1 results in Notch1 signaling activation and increased GSC populations. In contrast, knocking down LNX1 reverses these changes, causing a significant downregulation of NICD, reduction in stemness after TMZ therapy, and resulting in more prolonged median survival in a mouse model. Based on this, we propose that during anti-GBM chemotherapy, LNX1-regulated Notch1 signaling promotes stemness and contributes to therapeutic resistance.
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Nerli E, Rocha-Martins M, Norden C. Asymmetric neurogenic commitment of retinal progenitors involves Notch through the endocytic pathway. eLife 2020; 9:e60462. [PMID: 33141024 PMCID: PMC7679139 DOI: 10.7554/elife.60462] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 11/02/2020] [Indexed: 01/07/2023] Open
Abstract
During brain development, progenitor cells need to balanceproliferation and differentiation in order to generate different neurons in the correct numbers and proportions. Currently, the patterns of multipotent progenitor divisions that lead to neurogenic entry and the factors that regulate them are not fully understood. We here use the zebrafish retina to address this gap, exploiting its suitability for quantitative live-imaging. We show that early neurogenic progenitors arise from asymmetric divisions. Notch regulates this asymmetry, as when inhibited, symmetric divisions producing two neurogenic progenitors occur. Surprisingly however, Notch does not act through an apicobasal activity gradient as previously suggested, but through asymmetric inheritance of Sara-positive endosomes. Further, the resulting neurogenic progenitors show cell biological features different from multipotent progenitors, raising the possibility that an intermediate progenitor state exists in the retina. Our study thus reveals new insights into the regulation of proliferative and differentiative events during central nervous system development.
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Affiliation(s)
- Elisa Nerli
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Instituto Gulbenkian de CiênciaOeirasPortugal
| | - Mauricio Rocha-Martins
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Instituto Gulbenkian de CiênciaOeirasPortugal
| | - Caren Norden
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Instituto Gulbenkian de CiênciaOeirasPortugal
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26
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Islam IM, Ng J, Valentino P, Erclik T. Identification of enhancers that drive the spatially restricted expression of Vsx1 and Rx in the outer proliferation center of the developing Drosophila optic lobe. Genome 2020; 64:109-117. [PMID: 33054400 DOI: 10.1139/gen-2020-0034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Combinatorial spatial and temporal patterning of stem cells is a powerful mechanism for the generation of neural diversity in insect and vertebrate nervous systems. In the developing Drosophila medulla, the neural stem cells of the outer proliferation center (OPC) are spatially patterned by the mutually exclusive expression of three homeobox transcription factors: Vsx1 in the center of the OPC crescent (cOPC), Optix in the main arms (mOPC), and Rx in the posterior tips (pOPC). These spatial factors act together with a temporal cascade of transcription factors in OPC neuroblasts to specify the greater than 80 medulla cell types. Here, we identify the enhancers that are sufficient to drive the spatially restricted expression of the Vsx1 and Rx genes in the OPC. We show that removal of the cOPC enhancer in the Muddled inversion mutant leads to the loss of Vsx1 expression in the cOPC. Analysis of the evolutionarily conserved sequences within these enhancers suggests that direct repression by Optix may restrict the expression of Vsx1 and Rx to the cOPC and pOPC, respectively.
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Affiliation(s)
- Ishrat Maliha Islam
- Departments of Biology and Cell & Systems Biology, University of Toronto - Mississauga, Mississauga, ON., Canada
| | - June Ng
- Department of Biology, New York University, New York, USA
| | - Priscilla Valentino
- Departments of Biology and Cell & Systems Biology, University of Toronto - Mississauga, Mississauga, ON., Canada
| | - Ted Erclik
- Departments of Biology and Cell & Systems Biology, University of Toronto - Mississauga, Mississauga, ON., Canada
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27
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Ravenscroft TA, Janssens J, Lee PT, Tepe B, Marcogliese PC, Makhzami S, Holmes TC, Aerts S, Bellen HJ. Drosophila Voltage-Gated Sodium Channels Are Only Expressed in Active Neurons and Are Localized to Distal Axonal Initial Segment-like Domains. J Neurosci 2020; 40:7999-8024. [PMID: 32928889 PMCID: PMC7574647 DOI: 10.1523/jneurosci.0142-20.2020] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 07/15/2020] [Accepted: 08/04/2020] [Indexed: 12/28/2022] Open
Abstract
In multipolar vertebrate neurons, action potentials (APs) initiate close to the soma, at the axonal initial segment. Invertebrate neurons are typically unipolar with dendrites integrating directly into the axon. Where APs are initiated in the axons of invertebrate neurons is unclear. Voltage-gated sodium (NaV) channels are a functional hallmark of the axonal initial segment in vertebrates. We used an intronic Minos-Mediated Integration Cassette to determine the endogenous gene expression and subcellular localization of the sole NaV channel in both male and female Drosophila, para Despite being the only NaV channel in the fly, we show that only 23 ± 1% of neurons in the embryonic and larval CNS express para, while in the adult CNS para is broadly expressed. We generated a single-cell transcriptomic atlas of the whole third instar larval brain to identify para expressing neurons and show that it positively correlates with markers of differentiated, actively firing neurons. Therefore, only 23 ± 1% of larval neurons may be capable of firing NaV-dependent APs. We then show that Para is enriched in an axonal segment, distal to the site of dendritic integration into the axon, which we named the distal axonal segment (DAS). The DAS is present in multiple neuron classes in both the third instar larval and adult CNS. Whole cell patch clamp electrophysiological recordings of adult CNS fly neurons are consistent with the interpretation that Nav-dependent APs originate in the DAS. Identification of the distal NaV localization in fly neurons will enable more accurate interpretation of electrophysiological recordings in invertebrates.SIGNIFICANCE STATEMENT The site of action potential (AP) initiation in invertebrates is unknown. We tagged the sole voltage-gated sodium (NaV) channel in the fly, para, and identified that Para is enriched at a distal axonal segment. The distal axonal segment is located distal to where dendrites impinge on axons and is the likely site of AP initiation. Understanding where APs are initiated improves our ability to model neuronal activity and our interpretation of electrophysiological data. Additionally, para is only expressed in 23 ± 1% of third instar larval neurons but is broadly expressed in adults. Single-cell RNA sequencing of the third instar larval brain shows that para expression correlates with the expression of active, differentiated neuronal markers. Therefore, only 23 ± 1% of third instar larval neurons may be able to actively fire NaV-dependent APs.
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Affiliation(s)
- Thomas A Ravenscroft
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030
| | - Jasper Janssens
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium
- Department of Human Genetics, KU Leuven, Leuven 3000, Belgium
| | - Pei-Tseng Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030
| | - Burak Tepe
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030
| | - Paul C Marcogliese
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030
| | - Samira Makhzami
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium
- Department of Human Genetics, KU Leuven, Leuven 3000, Belgium
| | - Todd C Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California at Irvine, Irvine, California 92697
| | - Stein Aerts
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium
- Department of Human Genetics, KU Leuven, Leuven 3000, Belgium
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030
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28
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Chen YC, Desplan C. Gene regulatory networks during the development of the Drosophila visual system. Curr Top Dev Biol 2020; 139:89-125. [PMID: 32450970 DOI: 10.1016/bs.ctdb.2020.02.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The Drosophila visual system integrates input from 800 ommatidia and extracts different features in stereotypically connected optic ganglia. The development of the Drosophila visual system is controlled by gene regulatory networks that control the number of precursor cells, generate neuronal diversity by integrating spatial and temporal information, coordinate the timing of retinal and optic lobe cell differentiation, and determine distinct synaptic targets of each cell type. In this chapter, we describe the known gene regulatory networks involved in the development of the different parts of the visual system and explore general components in these gene networks. Finally, we discuss the advantages of the fly visual system as a model for gene regulatory network discovery in the era of single-cell transcriptomics.
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Affiliation(s)
- Yen-Chung Chen
- Department of Biology, New York University, New York, NY, United States
| | - Claude Desplan
- Department of Biology, New York University, New York, NY, United States.
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29
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Brenneis G, Beltz BS. Adult neurogenesis in crayfish: Origin, expansion, and migration of neural progenitor lineages in a pseudostratified neuroepithelium. J Comp Neurol 2019; 528:1459-1485. [PMID: 31743442 DOI: 10.1002/cne.24820] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/05/2019] [Accepted: 11/14/2019] [Indexed: 02/04/2023]
Abstract
Two decades after the discovery of adult-born neurons in the brains of decapod crustaceans, the deutocerebral proliferative system (DPS) producing these neural lineages has become a model of adult neurogenesis in invertebrates. Studies on crayfish have provided substantial insights into the anatomy, cellular dynamics, and regulation of the DPS. Contrary to traditional thinking, recent evidence suggests that the neurogenic niche in the crayfish DPS lacks self-renewing stem cells, its cell pool being instead sustained via integration of hemocytes generated by the innate immune system. Here, we investigated the origin, division and migration patterns of the adult-born neural progenitor (NP) lineages in detail. We show that the niche cell pool is not only replenished by hemocyte integration but also by limited numbers of symmetric cell divisions with some characteristics reminiscent of interkinetic nuclear migration. Once specified in the niche, first generation NPs act as transit-amplifying intermediate NPs that eventually exit and produce multicellular clones as they move along migratory streams toward target brain areas. Different clones may migrate simultaneously in the streams but occupy separate tracks and show spatio-temporally flexible division patterns. Based on this, we propose an extended DPS model that emphasizes structural similarities to pseudostratified neuroepithelia in other arthropods and vertebrates. This model includes hemocyte integration and intrinsic cell proliferation to synergistically counteract niche cell pool depletion during the animal's lifespan. Further, we discuss parallels to recent findings on mammalian adult neurogenesis, as both systems seem to exhibit a similar decoupling of proliferative replenishment divisions and consuming neurogenic divisions.
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Affiliation(s)
- Georg Brenneis
- Wellesley College, Neuroscience Program, Wellesley, Massachusetts, USA.,Universität Greifswald, Zoologisches Institut und Museum, AG Cytologie und Evolutionsbiologie, Greifswald, Germany
| | - Barbara S Beltz
- Wellesley College, Neuroscience Program, Wellesley, Massachusetts, USA
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30
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Brunet Avalos C, Maier GL, Bruggmann R, Sprecher SG. Single cell transcriptome atlas of the Drosophila larval brain. eLife 2019; 8:50354. [PMID: 31746739 PMCID: PMC6894929 DOI: 10.7554/elife.50354] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 11/19/2019] [Indexed: 12/15/2022] Open
Abstract
Cell diversity of the brain and how it is affected by starvation, remains largely unknown. Here, we introduce a single cell transcriptome atlas of the entire Drosophila first instar larval brain. We first assigned cell-type identity based on known marker genes, distinguishing five major groups: neural progenitors, differentiated neurons, glia, undifferentiated neurons and non-neural cells. All major classes were further subdivided into multiple subtypes, revealing biological features of various cell-types. We further assessed transcriptional changes in response to starvation at the single-cell level. While after starvation the composition of the brain remains unaffected, transcriptional profile of several cell clusters changed. Intriguingly, different cell-types show very distinct responses to starvation, suggesting the presence of cell-specific programs for nutrition availability. Establishing a single-cell transcriptome atlas of the larval brain provides a powerful tool to explore cell diversity and assess genetic profiles from developmental, functional and behavioral perspectives.
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Affiliation(s)
| | - G Larisa Maier
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Rémy Bruggmann
- Interfaculty Bioinformatics Unit, University of Bern, Bern, Switzerland
| | - Simon G Sprecher
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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31
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Zhou Y, Yang Y, Huang Y, Wang H, Wang S, Luo H. Broad Promotes Neuroepithelial Stem Cell Differentiation in the Drosophila Optic Lobe. Genetics 2019; 213:941-951. [PMID: 31530575 PMCID: PMC6827381 DOI: 10.1534/genetics.119.302421] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 09/08/2019] [Indexed: 11/18/2022] Open
Abstract
Brain development requires the generation of the right number, and type, of neurons and glial cells at the right time. The Drosophila optic lobe, like mammalian brains, develops from simple neuroepithelia; they first divide symmetrically to expand the progenitor pool and then differentiate into neuroblasts, which divide asymmetrically to generate neurons and glial cells. Here, we investigate the mechanisms that control neuroepithelial growth and differentiation in the optic lobe. We find that the Broad/Tramtrack/Bric a brac-zinc finger protein Broad, which is dynamically expressed in the optic lobe neuroepithelia, promotes the transition of neuroepithelial cells to medulla neuroblasts. Loss of Broad function causes neuroepithelial cells to remain highly proliferative and delays neuroepithelial cell differentiation into neuroblasts, which leads to defective lamina and medulla. Conversely, Broad overexpression induces neuroepithelial cells to prematurely transform into medulla neuroblasts. We find that the ecdysone receptor is required for neuroepithelial maintenance and growth, and that Broad expression in neuroepithelial cells is repressed by the ecdysone receptor. Our studies identify Broad as an important cell-intrinsic transcription factor that promotes the neuroepithelial-cell-to-neuroblast transition.
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Affiliation(s)
- Yanna Zhou
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yuqin Yang
- College of Biology, Hunan University, Changsha, Hunan 410082, China
| | - Yanyi Huang
- College of Biology, Hunan University, Changsha, Hunan 410082, China
| | - Hui Wang
- College of Biology, Hunan University, Changsha, Hunan 410082, China
| | - Shengyu Wang
- College of Biology, Hunan University, Changsha, Hunan 410082, China
| | - Hong Luo
- School of Life Sciences, Tsinghua University, Beijing 100084, China
- College of Biology, Hunan University, Changsha, Hunan 410082, China
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32
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Plazaola-Sasieta H, Zhu Q, Gaitán-Peñas H, Rios M, Estévez R, Morey M. Drosophila ClC-a is required in glia of the stem cell niche for proper neurogenesis and wiring of neural circuits. Glia 2019; 67:2374-2398. [PMID: 31479171 PMCID: PMC6851788 DOI: 10.1002/glia.23691] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 07/10/2019] [Accepted: 07/15/2019] [Indexed: 01/01/2023]
Abstract
Glial cells form part of the neural stem cell niche and express a wide variety of ion channels; however, the contribution of these channels to nervous system development is poorly understood. We explored the function of the Drosophila ClC‐a chloride channel, since its mammalian ortholog CLCN2 is expressed in glial cells, and defective channel function results in leukodystrophies, which in humans are accompanied by cognitive impairment. We found that ClC‐a was expressed in the niche in cortex glia, which are closely associated with neurogenic tissues. Characterization of loss‐of‐function ClC‐a mutants revealed that these animals had smaller brains and widespread wiring defects. We showed that ClC‐a is required in cortex glia for neurogenesis in neuroepithelia and neuroblasts, and identified defects in a neuroblast lineage that generates guidepost glial cells essential for photoreceptor axon guidance. We propose that glia‐mediated ionic homeostasis could nonautonomously affect neurogenesis, and consequently, the correct assembly of neural circuits.
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Affiliation(s)
- Haritz Plazaola-Sasieta
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Qi Zhu
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Héctor Gaitán-Peñas
- Departament de Ciencies Fisiològiques, Genes, Disease and Therapy Program IDIBELL-Institute of Neurosciences, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Martín Rios
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Raúl Estévez
- Departament de Ciencies Fisiològiques, Genes, Disease and Therapy Program IDIBELL-Institute of Neurosciences, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Morey
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain.,Institut de Biomedicina de la Universitat de Barcelona (IBUB), Programa de Biologia Integrativa, Barcelona, Spain
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33
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Contreras EG, Sierralta J, Oliva C. Novel Strategies for the Generation of Neuronal Diversity: Lessons From the Fly Visual System. Front Mol Neurosci 2019; 12:140. [PMID: 31213980 PMCID: PMC6554424 DOI: 10.3389/fnmol.2019.00140] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/13/2019] [Indexed: 12/17/2022] Open
Abstract
Among all organs of an adult animal, the central nervous system stands out because of its vast complexity and morphological diversity. During early development, the entire central nervous system develops from an apparently homogenous group of progenitors that differentiate into all neural cell types. Therefore, understanding the molecular and genetic mechanisms that give rise to the cellular and anatomical diversity of the brain is a key goal of the developmental neurobiology field. With this aim in mind, the development of the central nervous system of model organisms has been extensively studied. From more than a century, the mechanisms of neurogenesis have been studied in the fruit fly Drosophila melanogaster. The visual system comprises one of the major structures of the Drosophila brain. The visual information is collected by the eye-retina photoreceptors and then processed by the four optic lobe ganglia: the lamina, medulla, lobula and lobula plate. The molecular mechanisms that originate neuronal diversity in the optic lobe have been unveiled in the past decade. In this article, we describe the early development and differentiation of the lobula plate ganglion, from the formation of the optic placode and the inner proliferation center to the specification of motion detection neurons. We focused specifically on how the precise combination of signaling pathways and cell-specific transcription factors patterns the pool of neural stem cells that generates the different neurons of the motion detection system.
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Affiliation(s)
- Esteban G Contreras
- Department of Neuroscience and Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Jimena Sierralta
- Department of Neuroscience and Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Carlos Oliva
- Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
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34
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Akbari Kordkheyli V, Khonakdar Tarsi A, Mishan MA, Tafazoli A, Bardania H, Zarpou S, Bagheri A. Effects of quercetin on microRNAs: A mechanistic review. J Cell Biochem 2019; 120:12141-12155. [PMID: 30957271 DOI: 10.1002/jcb.28663] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/10/2019] [Accepted: 02/14/2019] [Indexed: 12/21/2022]
Abstract
MicroRNA (miRNA)-dependent pathways are one of the newest gene regulation mechanisms in various diseases, particularly in cancers. miRNAs are endogenous noncoding RNAs with about 18 to 25 nucleotide length, which can regulate the expression of at least 60% of human total genome posttranscriptionally. Quercetin is the most abundant flavonoid in a variety of fruits, flowers, and medical herbs, known as a strong free radical scavenger that could show antioxidant, anti-inflammatory, and antitumor activities. Recent studies also reported its strong impact on various miRNA expressions in different abnormalities. In this review, we aimed to summarize the studies focused on the effects of quercetin on different miRNA expressions to more clear the main possible mechanisms of quercetin influences and introduce it as a beneficial agent for regulation of miRNAs in various biological directions.
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Affiliation(s)
- Vahid Akbari Kordkheyli
- Department of Clinical Biochemistry-Biophysics and Genetics, Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Abbas Khonakdar Tarsi
- Department of Clinical Biochemistry-Biophysics and Genetics, Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mohammad A Mishan
- Ocular Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Alireza Tafazoli
- Department of Analysis and Bioanalysis of Medicines, Faculty of Pharmacy with the Division of Laboratory Medicine, Medical University of Bialystok, 15-089 Bialystok, Poland.,Department of Endocrinology, Diabetology and Internal Medicine, Clinical Research Center, Medical University of Bialystok, 15-276 Bialystok, Poland
| | - Hassan Bardania
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran
| | - Setareh Zarpou
- Department of Clinical Biochemistry-Biophysics and Genetics, Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Abouzar Bagheri
- Department of Clinical Biochemistry-Biophysics and Genetics, Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
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35
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Jörg DJ, Caygill EE, Hakes AE, Contreras EG, Brand AH, Simons BD. The proneural wave in the Drosophila optic lobe is driven by an excitable reaction-diffusion mechanism. eLife 2019; 8:e40919. [PMID: 30794154 PMCID: PMC6386523 DOI: 10.7554/elife.40919] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 02/08/2019] [Indexed: 11/13/2022] Open
Abstract
In living organisms, self-organised waves of signalling activity propagate spatiotemporal information within tissues. During the development of the largest component of the visual processing centre of the Drosophila brain, a travelling wave of proneural gene expression initiates neurogenesis in the larval optic lobe primordium and drives the sequential transition of neuroepithelial cells into neuroblasts. Here, we propose that this 'proneural wave' is driven by an excitable reaction-diffusion system involving epidermal growth factor receptor (EGFR) signalling interacting with the proneural gene l'sc. Within this framework, a propagating transition zone emerges from molecular feedback and diffusion. Ectopic activation of EGFR signalling in clones within the neuroepithelium demonstrates that a transition wave can be excited anywhere in the tissue by inducing signalling activity, consistent with a key prediction of the model. Our model illuminates the physical and molecular underpinnings of proneural wave progression and suggests a generic mechanism for regulating the sequential differentiation of tissues.
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Affiliation(s)
- David J Jörg
- Cavendish Laboratory, Department of PhysicsUniversity of CambridgeCambridgeUnited Kingdom
- The Wellcome Trust/Cancer Research UK Gurdon InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Elizabeth E Caygill
- The Wellcome Trust/Cancer Research UK Gurdon InstituteUniversity of CambridgeCambridgeUnited Kingdom
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Anna E Hakes
- The Wellcome Trust/Cancer Research UK Gurdon InstituteUniversity of CambridgeCambridgeUnited Kingdom
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUnited Kingdom
| | - Esteban G Contreras
- The Wellcome Trust/Cancer Research UK Gurdon InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Andrea H Brand
- The Wellcome Trust/Cancer Research UK Gurdon InstituteUniversity of CambridgeCambridgeUnited Kingdom
| | - Benjamin D Simons
- Cavendish Laboratory, Department of PhysicsUniversity of CambridgeCambridgeUnited Kingdom
- The Wellcome Trust/Cancer Research UK Gurdon InstituteUniversity of CambridgeCambridgeUnited Kingdom
- The Wellcome Trust/Medical Research Council Stem Cell InstituteUniversity of CambridgeCambridgeUnited Kingdom
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36
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Bielefeld P, Schouten M, Meijer GM, Breuk MJ, Geijtenbeek K, Karayel S, Tiaglik A, Vuuregge AH, Willems RAL, Witkamp D, Lucassen PJ, Encinas JM, Fitzsimons CP. Co-administration of Anti microRNA-124 and -137 Oligonucleotides Prevents Hippocampal Neural Stem Cell Loss Upon Non-convulsive Seizures. Front Mol Neurosci 2019; 12:31. [PMID: 30837840 PMCID: PMC6389789 DOI: 10.3389/fnmol.2019.00031] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 01/24/2019] [Indexed: 11/13/2022] Open
Abstract
Convulsive seizures promote adult hippocampal neurogenesis (AHN) through a transient activation of neural stem/progenitor cells (NSPCs) in the subgranular zone (SGZ) of the dentate gyrus (DG). However, in a significant population of epilepsy patients, non-convulsive seizures (ncSZ) are observed. The response of NSPCs to non-convulsive seizure induction has not been characterized before. We here studied first the short-term effects of controlled seizure induction on NSPCs fate and identity. We induced seizures of controlled intensity by intrahippocampally injecting increasing doses of the chemoconvulsant kainic acid (KA) and analyzed their effect on subdural EEG recordings, hippocampal structure, NSPC proliferation and the number and location of immature neurons shortly after seizure onset. After establishing a KA dose that elicits ncSZ, we then analyzed the effects of ncSZ on NSPC proliferation and NSC identity in the hippocampus. ncSZ specifically triggered neuroblast proliferation, but did not induce proliferation of NSPCs in the SGZ, 3 days post seizure onset. However, ncSZ induced significant changes in NSPC composition in the hippocampus, including the generation of reactive NSCs. Interestingly, intrahippocampal injection of a combination of two anti microRNA oligonucleotides targeting microRNA-124 and -137 normalized neuroblast proliferation and prevented NSC loss in the DG upon ncSZ. Our results show for the first time that ncSZ induce significant changes in neuroblast proliferation and NSC composition. Simultaneous antagonism of both microRNA-124 and -137 rescued seizure-induced alterations in NSPC, supporting their coordinated action in the regulation of NSC fate and proliferation and their potential for future seizure therapies.
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Affiliation(s)
- Pascal Bielefeld
- Neuroscience Program, Swammerdam Institute for Life Sciences, Faculty of Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Marijn Schouten
- Neuroscience Program, Swammerdam Institute for Life Sciences, Faculty of Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Guido M Meijer
- Neuroscience Program, Swammerdam Institute for Life Sciences, Faculty of Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Marit J Breuk
- Neuroscience Program, Swammerdam Institute for Life Sciences, Faculty of Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Karlijne Geijtenbeek
- Neuroscience Program, Swammerdam Institute for Life Sciences, Faculty of Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Sedef Karayel
- Neuroscience Program, Swammerdam Institute for Life Sciences, Faculty of Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Alisa Tiaglik
- Neuroscience Program, Swammerdam Institute for Life Sciences, Faculty of Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Anna H Vuuregge
- Neuroscience Program, Swammerdam Institute for Life Sciences, Faculty of Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Ruth A L Willems
- Neuroscience Program, Swammerdam Institute for Life Sciences, Faculty of Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Diede Witkamp
- Neuroscience Program, Swammerdam Institute for Life Sciences, Faculty of Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Paul J Lucassen
- Neuroscience Program, Swammerdam Institute for Life Sciences, Faculty of Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Juan M Encinas
- Achucarro Basque Center for Neuroscience, Bizkaia Science and Technology Park, Zamudio, Spain.,Ikerbasque Foundation, Bilbao, Spain.,University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Carlos P Fitzsimons
- Neuroscience Program, Swammerdam Institute for Life Sciences, Faculty of Sciences, University of Amsterdam, Amsterdam, Netherlands
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37
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Sei Y, Feng J, Chow CC, Wank SA. Asymmetric cell division-dominant neutral drift model for normal intestinal stem cell homeostasis. Am J Physiol Gastrointest Liver Physiol 2019; 316:G64-G74. [PMID: 30359083 PMCID: PMC6383375 DOI: 10.1152/ajpgi.00242.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The normal intestinal epithelium is continuously regenerated at a rapid rate from actively cycling Lgr5-expressing intestinal stem cells (ISCs) that reside at the crypt base. Recent mathematical modeling based on several lineage-tracing studies in mice shows that the symmetric cell division-dominant neutral drift model fits well with the observed in vivo growth of ISC clones and suggests that symmetric divisions are central to ISC homeostasis. However, other studies suggest a critical role for asymmetric cell division in the maintenance of ISC homeostasis in vivo. Here, we show that the stochastic branching and Moran process models with both a symmetric and asymmetric division mode not only simulate the stochastic growth of the ISC clone in silico but also closely fit the in vivo stem cell dynamics observed in lineage-tracing studies. In addition, the proposed model with highest probability for asymmetric division is more consistent with in vivo observations reported here and by others. Our in vivo studies of mitotic spindle orientations and lineage-traced progeny pairs indicate that asymmetric cell division is a dominant mode used by ISCs under normal homeostasis. Therefore, we propose the asymmetric cell division-dominant neutral drift model for normal ISC homeostasis. NEW & NOTEWORTHY The prevailing mathematical model suggests that intestinal stem cells (ISCs) divide symmetrically. The present study provides evidence that asymmetric cell division is the major contributor to ISC maintenance and thus proposes an asymmetric cell division-dominant neutral drift model. Consistent with this model, in vivo studies of mitotic spindle orientation and lineage-traced progeny pairs indicate that asymmetric cell division is the dominant mode used by ISCs under normal homeostasis.
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Affiliation(s)
- Yoshitatsu Sei
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Jianying Feng
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Carson C. Chow
- 2Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Stephen A. Wank
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
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38
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Ramon-Cañellas P, Peterson HP, Morante J. From Early to Late Neurogenesis: Neural Progenitors and the Glial Niche from a Fly's Point of View. Neuroscience 2018; 399:39-52. [PMID: 30578972 DOI: 10.1016/j.neuroscience.2018.12.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 12/06/2018] [Accepted: 12/12/2018] [Indexed: 12/15/2022]
Abstract
Drosophila melanogaster is an important model organism used to study the brain development of organisms ranging from insects to mammals. The central nervous system in fruit flies is formed primarily in two waves of neurogenesis, one of which occurs in the embryo and one of which occurs during larval stages. In order to understand neurogenesis, it is important to research the behavior of progenitor cells that give rise to the neural networks which make up the adult nervous system. This behavior has been shown to be influenced by different factors including interactions with other cells within the progenitor niche, or local tissue microenvironment. Glial cells form a crucial part of this niche and play an active role in the development of the brain. Although in the early years of neuroscience it was believed that glia were simply scaffolding for neurons and passive components of the nervous system, their importance is nowadays recognized. Recent discoveries in progenitors and niche cells have led to new understandings of how the developing brain shapes its diverse regions. In this review, we attempt to summarize the distinct neural progenitors and glia in the Drosophila melanogaster central nervous system, from embryo to late larval stages, and make note of homologous features in mammals. We also outline the recent advances in this field in order to define the impact that glial cells have on progenitor cell niches, and we finally emphasize the importance of communication between glia and progenitor cells for proper brain formation.
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Affiliation(s)
- Pol Ramon-Cañellas
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas (CSIC), and Universidad Miguel Hernández (UMH), Campus de Sant Joan, Apartado 18, 03550 Sant Joan, Alicante, Spain
| | - Hannah Payette Peterson
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas (CSIC), and Universidad Miguel Hernández (UMH), Campus de Sant Joan, Apartado 18, 03550 Sant Joan, Alicante, Spain
| | - Javier Morante
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas (CSIC), and Universidad Miguel Hernández (UMH), Campus de Sant Joan, Apartado 18, 03550 Sant Joan, Alicante, Spain.
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39
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Contreras EG, Egger B, Gold KS, Brand AH. Dynamic Notch signalling regulates neural stem cell state progression in the Drosophila optic lobe. Neural Dev 2018; 13:25. [PMID: 30466475 PMCID: PMC6251220 DOI: 10.1186/s13064-018-0123-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 11/13/2018] [Indexed: 11/10/2022] Open
Abstract
Background Neural stem cells generate all of the neurons and glial cells in the central nervous system, both during development and in the adult to maintain homeostasis. In the Drosophila optic lobe, neuroepithelial cells progress through two transient progenitor states, PI and PII, before transforming into neuroblasts. Here we analyse the role of Notch signalling in the transition from neuroepithelial cells to neuroblasts. Results We observed dynamic regulation of Notch signalling: strong activity in PI progenitors, low signalling in PII progenitors, and increased activity after neuroblast transformation. Ectopic expression of the Notch ligand Delta induced the formation of ectopic PI progenitors. Interestingly, we show that the E3 ubiquitin ligase, Neuralized, regulates Delta levels and Notch signalling activity at the transition zone. We demonstrate that the proneural transcription factor, Lethal of scute, is essential to induce expression of Neuralized and promote the transition from the PI progenitor to the PII progenitor state. Conclusions Our results show dynamic regulation of Notch signalling activity in the transition from neuroepithelial cells to neuroblasts. We propose a model in which Lethal of scute activates Notch signalling in a non-cell autonomous manner by regulating the expression of Neuralized, thereby promoting the progression between different neural stem cell states. Electronic supplementary material The online version of this article (10.1186/s13064-018-0123-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Esteban G Contreras
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK
| | - Boris Egger
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK.,Present Address: Department of Biology, Zoology, University of Fribourg, Chemin du Musée 10, CH-1700, Fribourg, Switzerland
| | - Katrina S Gold
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK
| | - Andrea H Brand
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK.
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40
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Xavier da Silveira Dos Santos A, Liberali P. From single cells to tissue self-organization. FEBS J 2018; 286:1495-1513. [PMID: 30390414 PMCID: PMC6519261 DOI: 10.1111/febs.14694] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 10/10/2018] [Accepted: 11/02/2018] [Indexed: 12/16/2022]
Abstract
Self-organization is a process by which interacting cells organize and arrange themselves in higher order structures and patterns. To achieve this, cells must have molecular mechanisms to sense their complex local environment and interpret it to respond accordingly. A combination of cell-intrinsic and cell-extrinsic cues are decoded by the single cells dictating their behaviour, their differentiation and symmetry-breaking potential driving development, tissue remodeling and regenerative processes. A unifying property of these self-organized pattern-forming systems is the importance of fluctuations, cell-to-cell variability, or noise. Cell-to-cell variability is an inherent and emergent property of populations of cells that maximize the population performance instead of the individual cell, providing tissues the flexibility to develop and maintain homeostasis in diverse environments. In this review, we will explore the role of self-organization and cell-to-cell variability as fundamental properties of multicellularity-and the requisite of single-cell resolution for its understanding. Moreover, we will analyze how single cells generate emergent multicellular dynamics observed at the tissue level 'travelling' across different scales: spatial, temporal and functional.
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Affiliation(s)
| | - Prisca Liberali
- Friedrich Miescher Institute for Biomedical Research (FMI), Basel, Switzerland.,University of Basel, Switzerland
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41
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Hakes AE, Otsuki L, Brand AH. A newly discovered neural stem cell population is generated by the optic lobe neuroepithelium during embryogenesis in Drosophila melanogaster. Development 2018; 145:145/18/dev166207. [PMID: 30254066 PMCID: PMC6176933 DOI: 10.1242/dev.166207] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 08/24/2018] [Indexed: 12/21/2022]
Abstract
Neural stem cells must balance symmetric and asymmetric cell divisions to generate a functioning brain of the correct size. In both the developing Drosophila visual system and mammalian cerebral cortex, symmetrically dividing neuroepithelial cells transform gradually into asymmetrically dividing progenitors that generate neurons and glia. As a result, it has been widely accepted that stem cells in these tissues switch from a symmetric, expansive phase of cell divisions to a later neurogenic phase of cell divisions. In the Drosophila optic lobe, this switch is thought to occur during larval development. However, we have found that neuroepithelial cells start to produce neuroblasts during embryonic development, demonstrating a much earlier role for neuroblasts in the developing visual system. These neuroblasts undergo neurogenic divisions, enter quiescence and are retained post-embryonically, together with neuroepithelial cells. Later in development, neuroepithelial cells undergo further cell divisions before transforming into larval neuroblasts. Our results demonstrate that the optic lobe neuroepithelium gives rise to neurons and glia over 60 h earlier than was thought previously. Highlighted Article: Two types of neural stem cell, with distinct proliferation modes, act side by side to generate the Drosophila optic lobe, challenging current dogma that they act sequentially.
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Affiliation(s)
- Anna E Hakes
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Leo Otsuki
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Andrea H Brand
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
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42
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Contreras EG, Palominos T, Glavic Á, Brand AH, Sierralta J, Oliva C. The transcription factor SoxD controls neuronal guidance in the Drosophila visual system. Sci Rep 2018; 8:13332. [PMID: 30190506 PMCID: PMC6127262 DOI: 10.1038/s41598-018-31654-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 08/23/2018] [Indexed: 01/21/2023] Open
Abstract
Precise control of neurite guidance during development is essential to ensure proper formation of neuronal networks and correct function of the central nervous system (CNS). How neuronal projections find their targets to generate appropriate synapses is not entirely understood. Although transcription factors are key molecules during neurogenesis, we do not know their entire function during the formation of networks in the CNS. Here, we used the Drosophila melanogaster optic lobe as a model for understanding neurite guidance during development. We assessed the function of Sox102F/SoxD, the unique Drosophila orthologue of the vertebrate SoxD family of transcription factors. SoxD is expressed in immature and mature neurons in the larval and adult lobula plate ganglia (one of the optic lobe neuropils), but is absent from glial cells, neural stem cells and progenitors of the lobula plate. SoxD RNAi knockdown in all neurons results in a reduction of the lobula plate neuropil, without affecting neuronal fate. This morphological defect is associated with an impaired optomotor response of adult flies. Moreover, knocking down SoxD only in T4/T5 neuronal types, which control motion vision, affects proper neurite guidance into the medulla and lobula. Our findings suggest that SoxD regulates neurite guidance, without affecting neuronal fate.
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Affiliation(s)
- Esteban G Contreras
- Department of Neuroscience and Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Independencia, 1027, Santiago, Chile.,Center for Genome Regulation, Faculty of Sciences, Universidad de Chile, Las Palmeras, 3425, Nuñoa, Santiago, Chile
| | - Tomás Palominos
- Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Av Libertador Bernardo O'Higgins 340, Santiago, Chile
| | - Álvaro Glavic
- Center for Genome Regulation, Faculty of Sciences, Universidad de Chile, Las Palmeras, 3425, Nuñoa, Santiago, Chile
| | - Andrea H Brand
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, United Kingdom
| | - Jimena Sierralta
- Department of Neuroscience and Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Independencia, 1027, Santiago, Chile
| | - Carlos Oliva
- Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Av Libertador Bernardo O'Higgins 340, Santiago, Chile.
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43
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Gopurappilly R, Deb BK, Chakraborty P, Hasan G. Stable STIM1 Knockdown in Self-Renewing Human Neural Precursors Promotes Premature Neural Differentiation. Front Mol Neurosci 2018; 11:178. [PMID: 29942250 PMCID: PMC6004407 DOI: 10.3389/fnmol.2018.00178] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Accepted: 05/09/2018] [Indexed: 12/31/2022] Open
Abstract
Ca2+ signaling plays a significant role in the development of the vertebrate nervous system where it regulates neurite growth as well as synapse and neurotransmitter specification. Elucidating the role of Ca2+ signaling in mammalian neuronal development has been largely restricted to either small animal models or primary cultures. Here we derived human neural precursor cells (NPCs) from human embryonic stem cells to understand the functional significance of a less understood arm of calcium signaling, Store-operated Ca2+ entry or SOCE, in neuronal development. Human NPCs exhibited robust SOCE, which was significantly attenuated by expression of a stable shRNA-miR targeted toward the SOCE molecule, STIM1. Along with the plasma membrane channel Orai, STIM is an essential component of SOCE in many cell types, where it regulates gene expression. Therefore, we measured global gene expression in human NPCs with and without STIM1 knockdown. Interestingly, pathways down-regulated through STIM1 knockdown were related to cell proliferation and DNA replication processes, whereas post-synaptic signaling was identified as an up-regulated process. To understand the functional significance of these gene expression changes we measured the self-renewal capacity of NPCs with STIM1 knockdown. The STIM1 knockdown NPCs demonstrated significantly reduced neurosphere size and number as well as precocious spontaneous differentiation toward the neuronal lineage, as compared to control cells. These findings demonstrate that STIM1 mediated SOCE in human NPCs regulates gene expression changes, that in vivo are likely to physiologically modulate the self-renewal and differentiation of NPCs.
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Affiliation(s)
- Renjitha Gopurappilly
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru, India
| | - Bipan Kumar Deb
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru, India
| | - Pragnya Chakraborty
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru, India
| | - Gaiti Hasan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru, India
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44
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Dark C, Homman-Ludiye J, Bryson-Richardson RJ. The role of ADHD associated genes in neurodevelopment. Dev Biol 2018; 438:69-83. [DOI: 10.1016/j.ydbio.2018.03.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 03/04/2018] [Accepted: 03/27/2018] [Indexed: 12/19/2022]
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45
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Caygill EE, Brand AH. miR-7 Buffers Differentiation in the Developing Drosophila Visual System. Cell Rep 2018; 20:1255-1261. [PMID: 28793250 PMCID: PMC5561169 DOI: 10.1016/j.celrep.2017.07.047] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 05/23/2017] [Accepted: 07/18/2017] [Indexed: 01/21/2023] Open
Abstract
The 40,000 neurons of the medulla, the largest visual processing center of the Drosophila brain, derive from a sheet of neuroepithelial cells. During larval development, a wave of differentiation sweeps across the neuroepithelium, converting neuroepithelial cells into neuroblasts that sequentially express transcription factors specifying different neuronal cell fates. The switch from neuroepithelial cells to neuroblasts is controlled by a complex gene regulatory network and is marked by the expression of the proneural gene l’sc. We discovered that microRNA miR-7 is expressed at the transition between neuroepithelial cells and neuroblasts. We showed that miR-7 promotes neuroepithelial cell-to-neuroblast transition by targeting downstream Notch effectors to limit Notch signaling. miR-7 acts as a buffer to ensure that a precise and stereotypical pattern of transition is maintained, even under conditions of environmental stress, echoing the role that miR-7 plays in the eye imaginal disc. This common mechanism reflects the importance of robust visual system development. miR-7 promotes neuroblast formation during optic lobe development miR-7 targets the Notch pathway miR-7 buffers the effects of environmental stress Without miR-7, timely neuroblast production is disrupted
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Affiliation(s)
- Elizabeth E Caygill
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Andrea H Brand
- The Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK.
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46
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Development of Concurrent Retinotopic Maps in the Fly Motion Detection Circuit. Cell 2018; 173:485-498.e11. [PMID: 29576455 DOI: 10.1016/j.cell.2018.02.053] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 12/24/2017] [Accepted: 02/21/2018] [Indexed: 11/22/2022]
Abstract
Understanding how complex brain wiring is produced during development is a daunting challenge. In Drosophila, information from 800 retinal ommatidia is processed in distinct brain neuropiles, each subdivided into 800 matching retinotopic columns. The lobula plate comprises four T4 and four T5 neuronal subtypes. T4 neurons respond to bright edge motion, whereas T5 neurons respond to dark edge motion. Each is tuned to motion in one of the four cardinal directions, effectively establishing eight concurrent retinotopic maps to support wide-field motion. We discovered a mode of neurogenesis where two sequential Notch-dependent divisions of either a horizontal or a vertical progenitor produce matching sets of two T4 and two T5 neurons retinotopically coincident with pairwise opposite direction selectivity. We show that retinotopy is an emergent characteristic of this neurogenic program and derives directly from neuronal birth order. Our work illustrates how simple developmental rules can implement complex neural organization.
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47
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Dillard C, Narbonne-Reveau K, Foppolo S, Lanet E, Maurange C. Two distinct mechanisms silence chinmo in Drosophila neuroblasts and neuroepithelial cells to limit their self-renewal. Development 2018; 145:dev.154534. [PMID: 29361557 DOI: 10.1242/dev.154534] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 12/18/2017] [Indexed: 02/03/2023]
Abstract
Whether common principles regulate the self-renewing potential of neural stem cells (NSCs) throughout the developing central nervous system is still unclear. In the Drosophila ventral nerve cord and central brain, asymmetrically dividing NSCs, called neuroblasts (NBs), progress through a series of sequentially expressed transcription factors that limits self-renewal by silencing a genetic module involving the transcription factor Chinmo. Here, we find that Chinmo also promotes neuroepithelium growth in the optic lobe during early larval stages by boosting symmetric self-renewing divisions while preventing differentiation. Neuroepithelium differentiation in late larvae requires the transcriptional silencing of chinmo by ecdysone, the main steroid hormone, therefore allowing coordination of neural stem cell self-renewal with organismal growth. In contrast, chinmo silencing in NBs is post-transcriptional and does not require ecdysone. Thus, during Drosophila development, humoral cues or tissue-intrinsic temporal specification programs respectively limit self-renewal in different types of neural progenitors through the transcriptional and post-transcriptional regulation of the same transcription factor.
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Affiliation(s)
- Caroline Dillard
- Aix Marseille Univ, CNRS, IBDM, Campus de Luminy Case 907, 13288 Marseille Cedex 9, France
| | - Karine Narbonne-Reveau
- Aix Marseille Univ, CNRS, IBDM, Campus de Luminy Case 907, 13288 Marseille Cedex 9, France
| | - Sophie Foppolo
- Aix Marseille Univ, CNRS, IBDM, Campus de Luminy Case 907, 13288 Marseille Cedex 9, France
| | - Elodie Lanet
- Aix Marseille Univ, CNRS, IBDM, Campus de Luminy Case 907, 13288 Marseille Cedex 9, France
| | - Cédric Maurange
- Aix Marseille Univ, CNRS, IBDM, Campus de Luminy Case 907, 13288 Marseille Cedex 9, France
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48
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Rujano MA, Cannata Serio M, Panasyuk G, Péanne R, Reunert J, Rymen D, Hauser V, Park JH, Freisinger P, Souche E, Guida MC, Maier EM, Wada Y, Jäger S, Krogan NJ, Kretz O, Nobre S, Garcia P, Quelhas D, Bird TD, Raskind WH, Schwake M, Duvet S, Foulquier F, Matthijs G, Marquardt T, Simons M. Mutations in the X-linked ATP6AP2 cause a glycosylation disorder with autophagic defects. J Exp Med 2017; 214:3707-3729. [PMID: 29127204 PMCID: PMC5716037 DOI: 10.1084/jem.20170453] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 08/01/2017] [Accepted: 09/22/2017] [Indexed: 12/25/2022] Open
Abstract
Rujano et al. report mutations in ATP6AP2 leading to liver disease, immunodeficiency, and psychomotor impairment. ATP6AP2 deficiency impairs the assembly and function of the V-ATPase proton pump, causing defects in protein glycosylation and autophagy. The biogenesis of the multi-subunit vacuolar-type H+-ATPase (V-ATPase) is initiated in the endoplasmic reticulum with the assembly of the proton pore V0, which is controlled by a group of assembly factors. Here, we identify two hemizygous missense mutations in the extracellular domain of the accessory V-ATPase subunit ATP6AP2 (also known as the [pro]renin receptor) responsible for a glycosylation disorder with liver disease, immunodeficiency, cutis laxa, and psychomotor impairment. We show that ATP6AP2 deficiency in the mouse liver caused hypoglycosylation of serum proteins and autophagy defects. The introduction of one of the missense mutations into Drosophila led to reduced survival and altered lipid metabolism. We further demonstrate that in the liver-like fat body, the autophagic dysregulation was associated with defects in lysosomal acidification and mammalian target of rapamycin (mTOR) signaling. Finally, both ATP6AP2 mutations impaired protein stability and the interaction with ATP6AP1, a member of the V0 assembly complex. Collectively, our data suggest that the missense mutations in ATP6AP2 lead to impaired V-ATPase assembly and subsequent defects in glycosylation and autophagy.
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Affiliation(s)
- Maria A Rujano
- Laboratory of Epithelial Biology and Disease, Imagine Institute, Paris, France.,Université Paris Descartes-Sorbonne Paris Cité, Imagine Institute, Paris, France
| | - Magda Cannata Serio
- Laboratory of Epithelial Biology and Disease, Imagine Institute, Paris, France.,Université Paris Descartes-Sorbonne Paris Cité, Imagine Institute, Paris, France
| | - Ganna Panasyuk
- Institut Necker-Enfants Malades, Paris, France.,Institut National de la Santé et de la Recherche Medicale U1151/Centre National de la Recherche Scientifique UMR 8253, Paris, France
| | - Romain Péanne
- University of Leuven (KU Leuven), Center for Human Genetics, Leuven, Belgium
| | - Janine Reunert
- Universitätsklinikum Münster, Klinik für Kinder- und Jugendmedizin, Münster, Germany
| | - Daisy Rymen
- University of Leuven (KU Leuven), Center for Human Genetics, Leuven, Belgium
| | - Virginie Hauser
- Laboratory of Epithelial Biology and Disease, Imagine Institute, Paris, France.,Institut National de la Santé et de la Recherche Medicale U1151/Centre National de la Recherche Scientifique UMR 8253, Paris, France
| | - Julien H Park
- Universitätsklinikum Münster, Klinik für Kinder- und Jugendmedizin, Münster, Germany
| | - Peter Freisinger
- Kreiskliniken Reutlingen, Klinik für Kinder- und Jugendmedizin, Klinikum am Steinenberg, Reutlingen, Germany
| | - Erika Souche
- University of Leuven (KU Leuven), Center for Human Genetics, Leuven, Belgium
| | - Maria Clara Guida
- Laboratory of Epithelial Biology and Disease, Imagine Institute, Paris, France.,Institut National de la Santé et de la Recherche Medicale U1151/Centre National de la Recherche Scientifique UMR 8253, Paris, France
| | - Esther M Maier
- Dr. von Haunersches Kinderspital der Universität München, München, Germany
| | - Yoshinao Wada
- Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan
| | - Stefanie Jäger
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA
| | - Nevan J Krogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA
| | - Oliver Kretz
- Centre for Biological Signaling Studies BIOSS, University of Freiburg, Freiburg, Germany
| | - Susana Nobre
- Metabolic Reference Center, Coimbra University Hospital Center, Coimbra, Portugal
| | - Paula Garcia
- Metabolic Reference Center, Coimbra University Hospital Center, Coimbra, Portugal
| | - Dulce Quelhas
- Biochemical Genetics Unit, Centro de Genética Médica Doutor Jacinto Magalhães, Centro Hospitalar do Porto, Abel Salazar Institute of Biomedical Sciences, University of Porto, Porto, Portugal
| | - Thomas D Bird
- Department of Neurology, University of Washington, Seattle, WA.,Geriatric Research Center, Veterans Administration Medical Center, Seattle, WA
| | - Wendy H Raskind
- Department of Medicine, University of Washington, Seattle, WA
| | - Michael Schwake
- Faculty of Chemistry/Biochemistry III, University Bielefeld, Bielefeld, Germany
| | - Sandrine Duvet
- Université Lille, Centre National de la Recherche Scientifique UMR 8576, Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Francois Foulquier
- Université Lille, Centre National de la Recherche Scientifique UMR 8576, Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Gert Matthijs
- University of Leuven (KU Leuven), Center for Human Genetics, Leuven, Belgium
| | - Thorsten Marquardt
- Universitätsklinikum Münster, Klinik für Kinder- und Jugendmedizin, Münster, Germany
| | - Matias Simons
- Laboratory of Epithelial Biology and Disease, Imagine Institute, Paris, France .,Université Paris Descartes-Sorbonne Paris Cité, Imagine Institute, Paris, France
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49
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Xu T, Park SS, Giaimo BD, Hall D, Ferrante F, Ho DM, Hori K, Anhezini L, Ertl I, Bartkuhn M, Zhang H, Milon E, Ha K, Conlon KP, Kuick R, Govindarajoo B, Zhang Y, Sun Y, Dou Y, Basrur V, Elenitoba-Johnson KS, Nesvizhskii AI, Ceron J, Lee CY, Borggrefe T, Kovall RA, Rual JF. RBPJ/CBF1 interacts with L3MBTL3/MBT1 to promote repression of Notch signaling via histone demethylase KDM1A/LSD1. EMBO J 2017; 36:3232-3249. [PMID: 29030483 PMCID: PMC5666606 DOI: 10.15252/embj.201796525] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 08/31/2017] [Accepted: 09/12/2017] [Indexed: 12/21/2022] Open
Abstract
Notch signaling is an evolutionarily conserved signal transduction pathway that is essential for metazoan development. Upon ligand binding, the Notch intracellular domain (NOTCH ICD) translocates into the nucleus and forms a complex with the transcription factor RBPJ (also known as CBF1 or CSL) to activate expression of Notch target genes. In the absence of a Notch signal, RBPJ acts as a transcriptional repressor. Using a proteomic approach, we identified L3MBTL3 (also known as MBT1) as a novel RBPJ interactor. L3MBTL3 competes with NOTCH ICD for binding to RBPJ. In the absence of NOTCH ICD, RBPJ recruits L3MBTL3 and the histone demethylase KDM1A (also known as LSD1) to the enhancers of Notch target genes, leading to H3K4me2 demethylation and to transcriptional repression. Importantly, in vivo analyses of the homologs of RBPJ and L3MBTL3 in Drosophila melanogaster and Caenorhabditis elegans demonstrate that the functional link between RBPJ and L3MBTL3 is evolutionarily conserved, thus identifying L3MBTL3 as a universal modulator of Notch signaling in metazoans.
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Affiliation(s)
- Tao Xu
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Sung-Soo Park
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | | | - Daniel Hall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | | | - Diana M Ho
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Kazuya Hori
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Lucas Anhezini
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Iris Ertl
- Cancer and Human Molecular Genetics, Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Marek Bartkuhn
- Institute for Genetics, University of Giessen, Giessen, Germany
| | - Honglai Zhang
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Eléna Milon
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kimberly Ha
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kevin P Conlon
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Rork Kuick
- Center for Cancer Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Brandon Govindarajoo
- Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Yang Zhang
- Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Yuqing Sun
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Yali Dou
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Venkatesha Basrur
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | | | - Alexey I Nesvizhskii
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA.,Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Julian Ceron
- Cancer and Human Molecular Genetics, Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Cheng-Yu Lee
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Tilman Borggrefe
- Institute of Biochemistry, University of Giessen, Giessen, Germany
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Jean-François Rual
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
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50
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Perry M, Konstantinides N, Pinto-Teixeira F, Desplan C. Generation and Evolution of Neural Cell Types and Circuits: Insights from the Drosophila Visual System. Annu Rev Genet 2017; 51:501-527. [PMID: 28961025 DOI: 10.1146/annurev-genet-120215-035312] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The Drosophila visual system has become a premier model for probing how neural diversity is generated during development. Recent work has provided deeper insight into the elaborate mechanisms that control the range of types and numbers of neurons produced, which neurons survive, and how they interact. These processes drive visual function and influence behavioral preferences. Other studies are beginning to provide insight into how neuronal diversity evolved in insects by adding new cell types and modifying neural circuits. Some of the most powerful comparisons have been those made to the Drosophila visual system, where a deeper understanding of molecular mechanisms allows for the generation of hypotheses about the evolution of neural anatomy and function. The evolution of new neural types contributes additional complexity to the brain and poses intriguing questions about how new neurons interact with existing circuitry. We explore how such individual changes in a variety of species might play a role over evolutionary timescales. Lessons learned from the fly visual system apply to other neural systems, including the fly central brain, where decisions are made and memories are stored.
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Affiliation(s)
- Michael Perry
- Department of Biology, New York University, New York, NY 10003, USA;
| | | | - Filipe Pinto-Teixeira
- Department of Biology, New York University, New York, NY 10003, USA; .,Center for Genomics and Systems Biology, New York University Abu Dhabi, Saadiyat Island, Abu Dhabi, United Arab Emirates
| | - Claude Desplan
- Department of Biology, New York University, New York, NY 10003, USA; .,Center for Genomics and Systems Biology, New York University Abu Dhabi, Saadiyat Island, Abu Dhabi, United Arab Emirates
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