51
|
Reduced Sympathetic Innervation in Endometriosis is Associated to Semaphorin 3C and 3F Expression. Mol Neurobiol 2016; 54:5131-5141. [PMID: 27558236 DOI: 10.1007/s12035-016-0058-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 08/15/2016] [Indexed: 12/16/2022]
Abstract
Endometriosis is a chronic inflammatory disease and one of the most common causes of pelvic pain. The mechanisms underlying pain emergence or chronic inflammation during endometriosis remain unknown. Several chronic inflammatory diseases including endometriosis show reduced amounts of noradrenergic nerve fibers. The source of the affected innervation is still unclear. Semaphorins represent potential elicitors, due to their known role as axonal guidance cues, and are suggested as nerve repellent factors in different chronic inflammatory diseases. Therefore, semaphorins might influence the progress of neuroinflammatory mechanisms during endometriosis. Here, we analyzed the noradrenergic innervation and the expression of the specific semaphorins and receptors possibly involved in the neuroimmunomodulation in endometriosis. Our studies revealed an affected innervation and a significant increase of semaphorins and their receptors in peritoneal endometriotic tissue. Thereby, the expression of the receptors was identified on the membrane of noradrenergic nerve fibers and vessels. Macrophages and activated fibroblasts were found in higher density levels and additionally express semaphorins in peritoneal endometriotic tissue. Inflammation leads to an increased release of immune cells, which secrete a variety of inflammatory factors capable of affecting innervation. Therefore, our data suggests that the chronic inflammatory condition in endometriosis might contribute to the increase of semaphorins, which could possibly affect the innervation in peritoneal endometriosis.
Collapse
|
52
|
Mesocortical Dopamine Phenotypes in Mice Lacking the Sonic Hedgehog Receptor Cdon. eNeuro 2016; 3:eN-NWR-0009-16. [PMID: 27419218 PMCID: PMC4942720 DOI: 10.1523/eneuro.0009-16.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 06/22/2016] [Accepted: 06/22/2016] [Indexed: 12/21/2022] Open
Abstract
Motivated behaviors and many psychopathologies typically involve changes in dopamine release from the projections of the ventral tegmental area (VTA) and/or the substantia nigra pars compacta (SNc). The morphogen Sonic Hedgehog (Shh) specifies fates of midbrain dopamine neurons, but VTA-specific effects of Shh signaling are also being uncovered. In this study, we assessed the role of the Shh receptor Cdon in the development of VTA and SNc dopamine neurons. We find that Cdon is expressed in the proliferating progenitor zone of the embryonic ventral midbrain and that the number of proliferating cells in this region is increased in mouse Cdon(-/-) embryos. Consistent with a role of Shh in the regulation of neuronal proliferation in this region, we find that the number of tyrosine hydroxylase (TH)-positive neurons is increased in the VTA of Cdon(-/-) mice at birth and that this effect endures into adulthood. In contrast, the number of TH-positive neurons in the SNc is not altered in Cdon(-/-) mice at either age. Moreover, adult Cdon(-/-) mice have a greater number of medial prefrontal cortex (mPFC) dopamine presynaptic sites, and increased baseline concentrations of dopamine and dopamine metabolites selectively in this region. Finally, consistent with increased dopamine function in the mPFC, we find that adult Cdon(-/-) mice fail to exhibit behavioral plasticity upon repeated amphetamine treatment. Based on these data, we suggest that Cdon plays an important role encoding the diversity of dopamine neurons in the midbrain, influencing both the development of the mesocortical dopamine pathway and behavioral outputs that involve this neural circuitry.
Collapse
|
53
|
Biechl D, Dorigo A, Köster RW, Grothe B, Wullimann MF. Eppur Si Muove: Evidence for an External Granular Layer and Possibly Transit Amplification in the Teleostean Cerebellum. Front Neuroanat 2016; 10:49. [PMID: 27199681 PMCID: PMC4852188 DOI: 10.3389/fnana.2016.00049] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 04/13/2016] [Indexed: 01/12/2023] Open
Abstract
The secreted signaling factor Sonic Hedgehog (Shh) acts in the floor plate of the developing vertebrate CNS to promote motoneuron development. In addition, shh has dorsal expression domains in the amniote alar plate (i.e., in isocortex, superior colliculus, and cerebellum). For example, shh expressing Purkinje cells act in transit amplification of external granular layer (EGL) cells of the developing cerebellum. Our previous studies had indicated the presence of an EGL in anamniote zebrafish, but a possible role of shh in the zebrafish cerebellar plate remained elusive. Therefore, we used an existing zebrafish transgenic line Tg(2.4shha-ABC-GFP)sb15; Shkumatava et al., 2004) to show this gene activity and its cellular localization in the larval zebrafish brain. Clearly, GFP expressing cells occur in larval alar zebrafish brain domains, i.e., optic tectum and cerebellum. Analysis of critical cerebellar cell markers on this transgenic background and a PH3 assay for mitotic cells reveals that Purkinje cells and eurydendroid cells are completely non-overlapping postmitotic cell populations. Furthermore, shh-GFP cells never express Zebrin II or parvalbumin, nor calretinin. They are thus neither Purkinje cells nor calretinin positive migrating rhombic lip derived cells. The shh-GFP cells also never correspond to PH3 positive cells of the ventral cerebellar proliferative zone or the upper rhombic lip-derived EGL. From this marker analysis and the location of shh-GFP cells sandwiched between calretinin positive rhombic lip derived cells and parvalbumin positive Purkinje cells, we conclude that shh-GFP expressing cells qualify as previously reported olig2 positive eurydendroid cells, which are homologous to the amniote deep cerebellar nuclei. We confirm this using double transgenic progeny of shh-GFP and olig2-dsRed zebrafish. Thus, these zebrafish eurydendroid cells may have the same role in transit amplification as Purkinje cells do in amniotes.
Collapse
Affiliation(s)
- Daniela Biechl
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München Munich, Germany
| | - Alessandro Dorigo
- Institute of Zoology, Cellular and Molecular Neurobiology, Technische Universität Braunschweig Braunschweig, Germany
| | - Reinhard W Köster
- Institute of Zoology, Cellular and Molecular Neurobiology, Technische Universität Braunschweig Braunschweig, Germany
| | - Benedikt Grothe
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München Munich, Germany
| | - Mario F Wullimann
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München Munich, Germany
| |
Collapse
|
54
|
Dopamine neurons share common response function for reward prediction error. Nat Neurosci 2016; 19:479-86. [PMID: 26854803 PMCID: PMC4767554 DOI: 10.1038/nn.4239] [Citation(s) in RCA: 170] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 01/07/2016] [Indexed: 02/07/2023]
Abstract
Dopamine neurons are thought to signal reward prediction error, or the difference between actual and predicted reward. How dopamine neurons jointly encode this information, however, remains unclear. One possibility is that different neurons specialize in different aspects of prediction error; another is that each neuron calculates prediction error in the same way. We recorded from optogenetically-identified dopamine neurons in the lateral ventral tegmental area (VTA) while mice performed classical conditioning tasks. Our tasks allowed us to determine the full prediction error functions of dopamine neurons and compare them to each other. We found striking homogeneity among individual dopamine neurons: their responses to both unexpected and expected rewards followed the same function, just scaled up or down. As a result, we could describe both individual and population responses using just two parameters. Such uniformity ensures robust information coding, allowing each dopamine neuron to contribute fully to the prediction error signal.
Collapse
|
55
|
Dickkopf 3 Promotes the Differentiation of a Rostrolateral Midbrain Dopaminergic Neuronal Subset In Vivo and from Pluripotent Stem Cells In Vitro in the Mouse. J Neurosci 2015; 35:13385-401. [PMID: 26424886 DOI: 10.1523/jneurosci.1722-15.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Wingless-related MMTV integration site 1 (WNT1)/β-catenin signaling plays a crucial role in the generation of mesodiencephalic dopaminergic (mdDA) neurons, including the substantia nigra pars compacta (SNc) subpopulation that preferentially degenerates in Parkinson's disease (PD). However, the precise functions of WNT1/β-catenin signaling in this context remain unknown. Stem cell-based regenerative (transplantation) therapies for PD have not been implemented widely in the clinical context, among other reasons because of the heterogeneity and incomplete differentiation of the transplanted cells. This might result in tumor formation and poor integration of the transplanted cells into the dopaminergic circuitry of the brain. Dickkopf 3 (DKK3) is a secreted glycoprotein implicated in the modulation of WNT/β-catenin signaling. Using mutant mice, primary ventral midbrain cells, and pluripotent stem cells, we show that DKK3 is necessary and sufficient for the correct differentiation of a rostrolateral mdDA neuron subset. Dkk3 transcription in the murine ventral midbrain coincides with the onset of mdDA neurogenesis and is required for the activation and/or maintenance of LMX1A (LIM homeobox transcription factor 1α) and PITX3 (paired-like homeodomain transcription factor 3) expression in the corresponding mdDA precursor subset, without affecting the proliferation or specification of their progenitors. Notably, the treatment of differentiating pluripotent stem cells with recombinant DKK3 and WNT1 proteins also increases the proportion of mdDA neurons with molecular SNc DA cell characteristics in these cultures. The specific effects of DKK3 on the differentiation of rostrolateral mdDA neurons in the murine ventral midbrain, together with its known prosurvival and anti-tumorigenic properties, make it a good candidate for the improvement of regenerative and neuroprotective strategies in the treatment of PD. Significance statement: We show here that Dickkopf 3 (DKK3), a secreted modulator of WNT (Wingless-related MMTV integration site)/β-catenin signaling, is both necessary and sufficient for the proper differentiation and survival of a rostrolateral (parabrachial pigmented nucleus and dorsomedial substantia nigra pars compacta) mesodiencephalic dopaminergic neuron subset, using Dkk3 mutant mice and murine primary ventral midbrain and pluripotent stem cells. The progressive loss of these dopamine-producing mesodiencephalic neurons is a hallmark of human Parkinson's disease, which can up to now not be halted by clinical treatments of this disease. Thus, the soluble DKK3 protein might be a promising new agent for the improvement of current protocols for the directed differentiation of pluripotent and multipotent stem cells into mesodiencephalic dopaminergic neurons and for the promotion of their survival in situ.
Collapse
|
56
|
Luo SX, Huang EJ. Dopaminergic Neurons and Brain Reward Pathways: From Neurogenesis to Circuit Assembly. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 186:478-88. [PMID: 26724386 DOI: 10.1016/j.ajpath.2015.09.023] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 09/01/2015] [Accepted: 09/23/2015] [Indexed: 11/26/2022]
Abstract
Midbrain dopaminergic (DA) neurons in the substantia nigra pars compacta and ventral tegmental area regulate extrapyramidal movement and important cognitive functions, including motivation, reward associations, and habit learning. Dysfunctions in DA neuron circuitry have been implicated in several neuropsychiatric disorders, including addiction and schizophrenia, whereas selective degeneration of DA neurons in substantia nigra pars compacta is a key neuropathological feature in Parkinson disease. Efforts to understand these disorders have focused on dissecting the underlying causes, as well as developing therapeutic strategies to replenish dopamine deficiency. In particular, the promise of cell replacement therapies for clinical intervention has led to extensive research in the identification of mechanisms involved in DA neuron development. It is hoped that a comprehensive understanding of these mechanisms will lead to therapeutic strategies that improve the efficiency of DA neuron production, engraftment, and function. This review provides a comprehensive discussion on how Wnt/β-catenin and sonic hedgehog-Smoothened signaling mechanisms control the specification and expansion of DA progenitors and the differentiation of DA neurons. We also discuss how mechanisms involving transforming growth factor-β and transcriptional cofactor homeodomain interacting protein kinase 2 regulate the survival and maturation of DA neurons in early postnatal life. These results not only reveal fundamental mechanisms regulating DA neuron development, but also provide important insights to their potential contributions to neuropsychiatric and neurodegenerative diseases.
Collapse
Affiliation(s)
- Sarah X Luo
- Neuroscience Graduate Program, University of California San Francisco, San Francisco, California; Department of Pathology, University of California San Francisco, San Francisco, California
| | - Eric J Huang
- Neuroscience Graduate Program, University of California San Francisco, San Francisco, California; Department of Pathology, University of California San Francisco, San Francisco, California; Pathology Service 113B, San Francisco Veterans Affairs Medical Center, San Francisco, California.
| |
Collapse
|
57
|
Gazea M, Tasouri E, Tolve M, Bosch V, Kabanova A, Gojak C, Kurtulmus B, Novikov O, Spatz J, Pereira G, Hübner W, Brodski C, Tucker KL, Blaess S. Primary cilia are critical for Sonic hedgehog-mediated dopaminergic neurogenesis in the embryonic midbrain. Dev Biol 2015; 409:55-71. [PMID: 26542012 DOI: 10.1016/j.ydbio.2015.10.033] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 10/21/2015] [Accepted: 10/30/2015] [Indexed: 02/07/2023]
Abstract
Midbrain dopaminergic (mDA) neurons modulate various motor and cognitive functions, and their dysfunction or degeneration has been implicated in several psychiatric diseases. Both Sonic Hedgehog (Shh) and Wnt signaling pathways have been shown to be essential for normal development of mDA neurons. Primary cilia are critical for the development of a number of structures in the brain by serving as a hub for essential developmental signaling cascades, but their role in the generation of mDA neurons has not been examined. We analyzed mutant mouse lines deficient in the intraflagellar transport protein IFT88, which is critical for primary cilia function. Conditional inactivation of Ift88 in the midbrain after E9.0 results in progressive loss of primary cilia, a decreased size of the mDA progenitor domain, and a reduction in mDA neurons. We identified Shh signaling as the primary cause of these defects, since conditional inactivation of the Shh signaling pathway after E9.0, through genetic ablation of Gli2 and Gli3 in the midbrain, results in a phenotype basically identical to the one seen in Ift88 conditional mutants. Moreover, the expansion of the mDA progenitor domain observed when Shh signaling is constitutively activated does not occur in absence of Ift88. In contrast, clusters of Shh-responding progenitors are maintained in the ventral midbrain of the hypomorphic Ift88 mouse mutant, cobblestone. Despite the residual Shh signaling, the integrity of the mDA progenitor domain is severely disturbed, and consequently very few mDA neurons are generated in cobblestone mutants. Our results identify for the first time a crucial role of primary cilia in the induction of mDA progenitors, define a narrow time window in which Shh-mediated signaling is dependent upon normal primary cilia function for this purpose, and suggest that later Wnt signaling-dependent events act independently of primary cilia.
Collapse
Affiliation(s)
- Mary Gazea
- Institute of Reconstructive Neurobiology, University of Bonn, 53127 Bonn, Germany
| | - Evangelia Tasouri
- Interdisciplinary Center for Neurosciences, University of Heidelberg, 69120 Heidelberg, Germany; Institute of Anatomy and Cell Biology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Marianna Tolve
- Institute of Reconstructive Neurobiology, University of Bonn, 53127 Bonn, Germany
| | - Viktoria Bosch
- Institute of Reconstructive Neurobiology, University of Bonn, 53127 Bonn, Germany
| | - Anna Kabanova
- Institute of Reconstructive Neurobiology, University of Bonn, 53127 Bonn, Germany
| | - Christian Gojak
- Department of Biophysical Chemistry, University of Heidelberg, 69120 Heidelberg, Germany; Department of New Materials and Biosystems, Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
| | - Bahtiyar Kurtulmus
- Molecular Biology of Centrosomes and Cilia, German Cancer Research Center, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Orna Novikov
- Department of Physiology and Cell Biology, Zlotowski Center for Neuroscience, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Joachim Spatz
- Department of Biophysical Chemistry, University of Heidelberg, 69120 Heidelberg, Germany; Department of New Materials and Biosystems, Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
| | - Gislene Pereira
- Molecular Biology of Centrosomes and Cilia, German Cancer Research Center, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Wolfgang Hübner
- Molecular Biophotonics, University of Bielefeld, 33615 Bielefeld, Germany
| | - Claude Brodski
- Department of Physiology and Cell Biology, Zlotowski Center for Neuroscience, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Kerry L Tucker
- Interdisciplinary Center for Neurosciences, University of Heidelberg, 69120 Heidelberg, Germany; Institute of Anatomy and Cell Biology, University of Heidelberg, 69120 Heidelberg, Germany; University of New England, College of Osteopathic Medicine, Department of Biomedical Sciences, Center for Excellence in the Neurosciences, Biddeford, ME 04005, USA.
| | - Sandra Blaess
- University of New England, College of Osteopathic Medicine, Department of Biomedical Sciences, Center for Excellence in the Neurosciences, Biddeford, ME 04005, USA.
| |
Collapse
|
58
|
Bodea GO, Blaess S. Establishing diversity in the dopaminergic system. FEBS Lett 2015; 589:3773-85. [PMID: 26431946 DOI: 10.1016/j.febslet.2015.09.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Revised: 09/13/2015] [Accepted: 09/16/2015] [Indexed: 11/19/2022]
Abstract
Midbrain dopaminergic neurons (MbDNs) modulate cognitive processes, regulate voluntary movement, and encode reward prediction errors and aversive stimuli. While the degeneration of MbDNs underlies the motor defects in Parkinson's disease, imbalances in dopamine levels are associated with neuropsychiatric disorders such as depression, schizophrenia and substance abuse. In recent years, progress has been made in understanding how MbDNs, which constitute a relatively small neuronal population in the brain, can contribute to such diverse functions and dysfunctions. In particular, important insights have been gained regarding the distinct molecular, neurochemical and network properties of MbDNs. How this diversity of MbDNs is established during brain development is only starting to be unraveled. In this review, we summarize the current knowledge on the diversity in MbDN progenitors and differentiated MbDNs in the developing rodent brain. We discuss the signaling pathways, transcription factors and transmembrane receptors that contribute to setting up these diverse MbDN subpopulations. A better insight into the processes that establish diversity in MbDNs will ultimately improve the understanding of the architecture and function of the dopaminergic system in the adult brain.
Collapse
Affiliation(s)
- Gabriela O Bodea
- Mater Research Institute - University of Queensland, Translational Research Institute, Woolloongabba, QLD 4102, Australia; Queensland Brain Institute, University of Queensland, Brisbane, QLD 4072, Australia
| | - Sandra Blaess
- Institute of Reconstructive Neurobiology, Life and Brain Center, University of Bonn, Bonn, Germany.
| |
Collapse
|
59
|
Nouri N, Patel MJ, Joksimovic M, Poulin JF, Anderegg A, Taketo MM, Ma YC, Awatramani R. Excessive Wnt/beta-catenin signaling promotes midbrain floor plate neurogenesis, but results in vacillating dopamine progenitors. Mol Cell Neurosci 2015; 68:131-42. [PMID: 26164566 PMCID: PMC4633300 DOI: 10.1016/j.mcn.2015.07.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 06/30/2015] [Accepted: 07/04/2015] [Indexed: 01/10/2023] Open
Abstract
The floor plate (FP), a ventral midline structure of the developing neural tube, has differential neurogenic capabilities along the anterior-posterior axis. The midbrain FP, unlike the hindbrain and spinal cord floor plate, is highly neurogenic and produces midbrain dopaminergic (mDA) neurons. Canonical Wnt/beta-catenin signaling, at least in part, is thought to account for the difference in neurogenic capability. Removal of beta-catenin results in mDA progenitor specification defects as well as a profound reduction of neurogenesis. To examine the effects of excessive Wnt/beta-catenin signaling on mDA specification and neurogenesis, we have analyzed a model wherein beta-catenin is conditionally stabilized in the Shh+domain. Here, we show that the Foxa2+/Lmx1a+ domain is extended rostrally in mutant embryos, suggesting that canonical Wnt/beta-catenin signaling can drive FP expansion along the rostrocaudal axis. Although excess canonical Wnt/beta-catenin signaling generally promotes neurogenesis at midbrain levels, less tyrosine hydroxylase (Th)+, mDA neurons are generated, particularly impacting the Substantia Nigra pars compacta. This is likely because of improper progenitor specification. Excess canonical Wnt/beta-catenin signaling causes downregulation of net Lmx1b, Shh and Foxa2 levels in mDA progenitors. Moreover, these progenitors assume a mixed identity to that of Lmx1a+/Lmx1b+/Nkx6-1+/Neurog1+ progenitors. We also show by lineage tracing analysis that normally, Neurog1+ progenitors predominantly give rise to Pou4f1+ neurons, but not Th+ neurons. Accordingly, in the mutant embryos, Neurog1+ progenitors at the midline generate ectopic Pou4f1+ neurons at the expense of Th+ mDA neurons. Our study suggests that an optimal dose of Wnt/beta-catenin signaling is critical for proper establishment of the mDA progenitor character. Our findings will impact embryonic stem cell protocols that utilize Wnt pathway reagents to derive mDA neuron models and therapeutics for Parkinson's disease.
Collapse
Affiliation(s)
- Navid Nouri
- Northwestern University, Feinberg Medical School, Department of Neurology and Center for Genetic Medicine, 7-113 Lurie Bldg., 303 E Superior Street, Chicago, IL 60611, USA.
| | - Meera J Patel
- Northwestern University, Feinberg Medical School, Department of Neurology and Center for Genetic Medicine, 7-113 Lurie Bldg., 303 E Superior Street, Chicago, IL 60611, USA; Committee on Neurobiology, University of Chicago, 924 E 57th St. R222, Chicago, IL 60637, USA.
| | - Milan Joksimovic
- Northwestern University, Feinberg Medical School, Department of Neurology and Center for Genetic Medicine, 7-113 Lurie Bldg., 303 E Superior Street, Chicago, IL 60611, USA.
| | - Jean-Francois Poulin
- Northwestern University, Feinberg Medical School, Department of Neurology and Center for Genetic Medicine, 7-113 Lurie Bldg., 303 E Superior Street, Chicago, IL 60611, USA.
| | - Angela Anderegg
- Northwestern University, Feinberg Medical School, Department of Neurology and Center for Genetic Medicine, 7-113 Lurie Bldg., 303 E Superior Street, Chicago, IL 60611, USA.
| | - M Mark Taketo
- Graduate School of Medicine, Kyoto University, Yoshida-Konoé-cho, Sakyo, Kyoto 606-8501, Japan.
| | - Yong-Chao Ma
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Children's Hospital of Chicago Research Center, 2430 North Halsted Street, Room C321, Chicago, IL 60614, USA.
| | - Rajeshwar Awatramani
- Northwestern University, Feinberg Medical School, Department of Neurology and Center for Genetic Medicine, 7-113 Lurie Bldg., 303 E Superior Street, Chicago, IL 60611, USA.
| |
Collapse
|
60
|
Heide M, Zhang Y, Zhou X, Zhao T, Miquelajáuregui A, Varela-Echavarría A, Alvarez-Bolado G. Lhx5 controls mamillary differentiation in the developing hypothalamus of the mouse. Front Neuroanat 2015; 9:113. [PMID: 26321924 PMCID: PMC4536661 DOI: 10.3389/fnana.2015.00113] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 07/30/2015] [Indexed: 12/30/2022] Open
Abstract
Acquisition of specific neuronal identity by individual brain nuclei is a key step in brain development. However, how the mechanisms that confer neuronal identity are integrated with upstream regional specification networks is still mysterious. Expression of Sonic hedgehog (Shh), is required for hypothalamic specification and is later downregulated by Tbx3 to allow for the differentiation of the tubero-mamillary region. In this region, the mamillary body (MBO), is a large neuronal aggregate essential for memory formation. To clarify how MBO identity is acquired after regional specification, we investigated Lhx5, a transcription factor with restricted MBO expression. We first generated a hypomorph allele of Lhx5—in homozygotes, the MBO disappears after initial specification. Intriguingly, in these mutants, Tbx3 was downregulated and the Shh expression domain abnormally extended. Microarray analysis and chromatin immunoprecipitation indicated that Lhx5 appears to be involved in Shh downregulation through Tbx3 and activates several MBO-specific regulator and effector genes. Finally, by tracing the caudal hypothalamic cell lineage we show that, in the Lhx5 mutant, at least some MBO cells are present but lack characteristic marker expression. Our work shows how the Lhx5 locus contributes to integrate regional specification pathways with downstream acquisition of neuronal identity in the MBO.
Collapse
Affiliation(s)
- Michael Heide
- Institute of Anatomy and Cell Biology, University of Heidelberg Heidelberg, Germany
| | - Yuanfeng Zhang
- Institute of Anatomy and Cell Biology, University of Heidelberg Heidelberg, Germany
| | - Xunlei Zhou
- Institute of Anatomy and Cell Biology, University of Heidelberg Heidelberg, Germany
| | - Tianyu Zhao
- Key Laboratory of Oral Disease and Biomedical Sciences, Stomatological Hospital, Chongqing Medical University Chongqing, China
| | - Amaya Miquelajáuregui
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México Querétaro, Mexico
| | - Alfredo Varela-Echavarría
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México Querétaro, Mexico
| | | |
Collapse
|
61
|
Niederkofler V, Asher TE, Dymecki SM. Functional Interplay between Dopaminergic and Serotonergic Neuronal Systems during Development and Adulthood. ACS Chem Neurosci 2015; 6:1055-1070. [PMID: 25747116 DOI: 10.1021/acschemneuro.5b00021] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The complex integration of neurotransmitter signals in the nervous system contributes to the shaping of behavioral and emotional constitutions throughout development. Imbalance among these signals may result in pathological behaviors and psychiatric illnesses. Therefore, a better understanding of the interplay between neurotransmitter systems holds potential to facilitate therapeutic development. Of particular clinical interest are the dopaminergic and serotonergic systems, as both modulate a broad array of behaviors and emotions and have been implicated in a wide range of affective disorders. Here we review evidence speaking to an interaction between the dopaminergic and serotonergic neuronal systems across development. We highlight data stemming from developmental, functional, and clinical studies, reflecting the importance of this transmonoaminergic interplay.
Collapse
Affiliation(s)
- Vera Niederkofler
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Tedi E. Asher
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Susan M. Dymecki
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| |
Collapse
|
62
|
Şişecioğlu M, Budak H, Geffers L, Çankaya M, Çiftci M, Thaller C, Eichele G, Küfrevioğlu Öİ, Özdemir H. A compendium of expression patterns of cholesterol biosynthetic enzymes in the mouse embryo. J Lipid Res 2015; 56:1551-9. [PMID: 26108225 PMCID: PMC4513996 DOI: 10.1194/jlr.m059634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Indexed: 11/20/2022] Open
Abstract
Cholesterol and its biosynthetic pathway intermediates and derivatives are required for many developmental processes including membrane biogenesis, transmembrane receptor signaling, steroid biogenesis, nuclear receptor activation, and posttranslational modification of hedgehog (Hh) proteins. To perform such multifaceted tasks depends on stringent regulation of expression of cholesterol biosynthetic enzymes (CBEs). We established for a whole organism, for the first time, the 3D expression pattern of all genes required for cholesterol biosynthesis (CBS), starting from acetyl-CoA and ending with cholesterol. This data was produced by high-throughput in situ hybridization on serial sections through the mouse fetus. The textually annotated image data were seamlessly integrated into the METscout and GenePaint public databases. This novel information helps in the understanding of why CBEs are expressed at particular locations within the fetus. For example, strong CBE expression is detected at sites of cell proliferation and also where cell growth increases membrane surface, such as in neurons sprouting axons and forming synapses. The CBE data also sheds light on the spatial relationship of cells and tissue that express sonic Hh (Shh) and produce cholesterol, respectively. We discovered that not all cells expressing Shh are capable of CBS. This finding suggests novel ways by which cholesterylation of Shh is regulated.
Collapse
Affiliation(s)
- Melda Şişecioğlu
- Departments of Molecular Biology and Genetics Faculty of Science, Ataturk University, 25240 Erzurum, Turkey
| | - Harun Budak
- Departments of Molecular Biology and Genetics Faculty of Science, Ataturk University, 25240 Erzurum, Turkey Genes and Behavior Department, Max Planck Institute of Biophysical Chemistry, 37077 Goettingen, Germany
| | - Lars Geffers
- Genes and Behavior Department, Max Planck Institute of Biophysical Chemistry, 37077 Goettingen, Germany
| | - Murat Çankaya
- Genes and Behavior Department, Max Planck Institute of Biophysical Chemistry, 37077 Goettingen, Germany Department of Biology, Faculty of Arts and Sciences, Erzincan University, 24100 Erzincan, Turkey
| | - Mehmet Çiftci
- Chemistry, Faculty of Science, Ataturk University, 25240 Erzurum, Turkey Department of Chemistry, Faculty of Arts and Sciences, Bingol University, 12000 Bingol, Turkey
| | - Christina Thaller
- Genes and Behavior Department, Max Planck Institute of Biophysical Chemistry, 37077 Goettingen, Germany
| | - Gregor Eichele
- Genes and Behavior Department, Max Planck Institute of Biophysical Chemistry, 37077 Goettingen, Germany
| | | | - Hasan Özdemir
- Chemistry, Faculty of Science, Ataturk University, 25240 Erzurum, Turkey
| |
Collapse
|
63
|
Abstract
ABSTRACT
Midbrain dopaminergic (mDA) neuron development has been an intense area of research during recent years. This is due in part to a growing interest in regenerative medicine and the hope that treatment for diseases affecting mDA neurons, such as Parkinson's disease (PD), might be facilitated by a better understanding of how these neurons are specified, differentiated and maintained in vivo. This knowledge might help to instruct efforts to generate mDA neurons in vitro, which holds promise not only for cell replacement therapy, but also for disease modeling and drug discovery. In this Primer, we will focus on recent developments in understanding the molecular mechanisms that regulate the development of mDA neurons in vivo, and how they have been used to generate human mDA neurons in vitro from pluripotent stem cells or from somatic cells via direct reprogramming. Current challenges and future avenues in the development of a regenerative medicine for PD will be identified and discussed.
Collapse
Affiliation(s)
- Ernest Arenas
- Laboratory of Molecular Neurobiology, Dept. Medical Biochemistry and Biophysics, Center of Developmental Biology for Regenerative Medicine, Karolinska Institutet, Stockholm 171 77, Sweden
| | - Mark Denham
- Laboratory of Molecular Neurobiology, Dept. Medical Biochemistry and Biophysics, Center of Developmental Biology for Regenerative Medicine, Karolinska Institutet, Stockholm 171 77, Sweden
- Danish Research Institute of Translational Neuroscience, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus 8000, Denmark
| | - J. Carlos Villaescusa
- Laboratory of Molecular Neurobiology, Dept. Medical Biochemistry and Biophysics, Center of Developmental Biology for Regenerative Medicine, Karolinska Institutet, Stockholm 171 77, Sweden
- Institute of Experimental Biology, Faculty of Science, Masaryk University, Brno 61137, Czech Republic
| |
Collapse
|
64
|
Function and developmental origin of a mesocortical inhibitory circuit. Nat Neurosci 2015; 18:872-82. [DOI: 10.1038/nn.4020] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 04/16/2015] [Indexed: 02/07/2023]
|
65
|
Haddad-Tóvolli R, Paul FA, Zhang Y, Zhou X, Theil T, Puelles L, Blaess S, Alvarez-Bolado G. Differential requirements for Gli2 and Gli3 in the regional specification of the mouse hypothalamus. Front Neuroanat 2015; 9:34. [PMID: 25859185 PMCID: PMC4373379 DOI: 10.3389/fnana.2015.00034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 03/09/2015] [Indexed: 11/13/2022] Open
Abstract
Secreted protein Sonic hedgehog (Shh) ventralizes the neural tube by modulating the crucial balance between activating and repressing functions (GliA, GliR) of transcription factors Gli2 and Gli3. This balance—the Shh-Gli code—is species- and context-dependent and has been elucidated for the mouse spinal cord. The hypothalamus, a forebrain region regulating vital functions like homeostasis and hormone secretion, shows dynamic and intricate Shh expression as well as complex regional differentiation. Here we asked if particular combinations of Gli2 and Gli3 and of GliA and GliR functions contribute to the variety of hypothalamic regions, i.e., we wanted to approach the question of a possible hypothalamic version of the Shh-Gli code. Based on mouse mutant analysis, we show that: (1) hypothalamic regional heterogeneity is based in part on differentially stringent requirements for Gli2 or Gli3; (2) another source of diversity are differential requirements for Shh of neural vs. non-neural origin; (3) the medial progenitor domain known to depend on Gli2 for its development generates several essential hypothalamic nuclei plus the pituitary and median eminence; (4) the suppression of Gli3R by neural and non-neural Shh is essential for hypothalamic specification. Finally, we have mapped our results on a recent model which considers the hypothalamus as a transverse region with alar and basal portions. Our data confirm the model and are explained by it.
Collapse
Affiliation(s)
- Roberta Haddad-Tóvolli
- Department of Medical Cell Biology and Neuroanatomy, University of Heidelberg Heidelberg, Germany
| | - Fabian A Paul
- Laboratory of Neurodevelopmental Genetics, Institute of Reconstructive Neurobiology, Life and Brain Center, University of Bonn Bonn, Germany
| | - Yuanfeng Zhang
- Department of Medical Cell Biology and Neuroanatomy, University of Heidelberg Heidelberg, Germany
| | - Xunlei Zhou
- Department of Medical Cell Biology and Neuroanatomy, University of Heidelberg Heidelberg, Germany
| | - Thomas Theil
- Centre for Integrative Physiology, University of Edinburgh Edinburgh, UK
| | - Luis Puelles
- Department of Morphology, Instituto Murciano de Investigación Biosanitaria, School of Medicine, University of Murcia Murcia, Spain ; Facultad de Medicina, University of Murcia Murcia, Spain
| | - Sandra Blaess
- Laboratory of Neurodevelopmental Genetics, Institute of Reconstructive Neurobiology, Life and Brain Center, University of Bonn Bonn, Germany
| | - Gonzalo Alvarez-Bolado
- Department of Medical Cell Biology and Neuroanatomy, University of Heidelberg Heidelberg, Germany
| |
Collapse
|
66
|
Somaa FA, Bye CR, Thompson LH, Parish CL. Meningeal cells influence midbrain development and the engraftment of dopamine progenitors in Parkinsonian mice. Exp Neurol 2015; 267:30-41. [PMID: 25708989 DOI: 10.1016/j.expneurol.2015.02.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 01/30/2015] [Accepted: 02/09/2015] [Indexed: 01/09/2023]
Abstract
Dopaminergic neuroblasts, isolated from ventral midbrain fetal tissue, have been shown to structurally and functionally integrate, and alleviate Parkinsonian symptoms following transplantation. The use of donor tissue isolated at an age younger than conventionally employed can result in larger grafts - a consequence of improved cell survival and neuroblast proliferation at the time of implantation. However studies have paid little attention to removal of the meninges from younger tissue, due to its age-dependent tight attachment to the underlying brain. Beyond the protection of the central nervous system, the meninges act as a signaling center, secreting a variety of trophins to influence neural development and additionally impact on neural repair. However it remains to be elucidated what influence these cells have on ventral midbrain development and grafted dopaminergic neuroblasts. Here we examined the temporal role of meningeal cells in graft integration in Parkinsonian mice and, using in vitro approaches, identified the mechanisms underlying the roles of meningeal cells in midbrain development. We demonstrate that young (embryonic day 10), but not older (E12), meningeal cells promote dopaminergic differentiation as well as neurite growth and guidance within grafts and during development. Furthermore we identify stromal derived factor 1 (SDF1), secreted by the meninges and acting on the CXCR4 receptor present on dopaminergic progenitors, as a contributory mediator in these effects. These findings identify new and important roles for the meningeal cells, and SDF1/CXCR4 signaling, in ventral midbrain development as well as neural repair following cell transplantation into the Parkinsonian brain.
Collapse
Affiliation(s)
- Fahad A Somaa
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Christopher R Bye
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Lachlan H Thompson
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Clare L Parish
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3010, Australia.
| |
Collapse
|
67
|
Blaess S, Szabó N, Haddad-Tóvolli R, Zhou X, Álvarez-Bolado G. Sonic hedgehog signaling in the development of the mouse hypothalamus. Front Neuroanat 2015; 8:156. [PMID: 25610374 PMCID: PMC4285088 DOI: 10.3389/fnana.2014.00156] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 12/02/2014] [Indexed: 11/13/2022] Open
Abstract
The expression pattern of Sonic Hedgehog (Shh) in the developing hypothalamus changes over time. Shh is initially expressed in the prechordal mesoderm and later in the hypothalamic neuroepithelium—first medially, and then in two off-medial domains. This dynamic expression suggests that Shh might regulate several aspects of hypothalamic development. To gain insight into them, lineage tracing, (conditional) gene inactivation in mouse, in ovo loss- and gain-of-function approaches in chick and analysis of Shh expression regulation have been employed. We will focus on mouse studies and refer to chick and fish when appropriate to clarify. These studies show that Shh-expressing neuroepithelial cells serve as a signaling center for neighboring precursors, and give rise to most of the basal hypothalamus (tuberal and mammillary regions). Shh signaling is initially essential for hypothalamic induction. Later, Shh signaling from the neuroepithelium controls specification of the lateral hypothalamic area and growth-patterning coordination in the basal hypothalamus. To further elucidate the role of Shh in hypothalamic development, it will be essential to understand how Shh regulates the downstream Gli transcription factors.
Collapse
Affiliation(s)
- Sandra Blaess
- Neurodevelopmental Genetics, Institute of Reconstructive Neurobiology, University of Bonn Bonn, Germany
| | - Nora Szabó
- Department of Neurobiology and Development, Institut de Recherches Cliniques de Montréal Montréal, QC, Canada
| | - Roberta Haddad-Tóvolli
- Department of Medical Cell Biology, Institute of Anatomy and Cell Biology, University of Heidelberg Heidelberg, Germany
| | - Xunlei Zhou
- Department of Medical Cell Biology, Institute of Anatomy and Cell Biology, University of Heidelberg Heidelberg, Germany
| | - Gonzalo Álvarez-Bolado
- Department of Medical Cell Biology, Institute of Anatomy and Cell Biology, University of Heidelberg Heidelberg, Germany
| |
Collapse
|
68
|
Blaess S, Ang SL. Genetic control of midbrain dopaminergic neuron development. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2015; 4:113-34. [PMID: 25565353 DOI: 10.1002/wdev.169] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 10/31/2014] [Accepted: 11/16/2014] [Indexed: 12/31/2022]
Abstract
UNLABELLED Midbrain dopaminergic neurons are involved in regulating motor control, reward behavior, and cognition. Degeneration or dysfunction of midbrain dopaminergic neurons is implicated in several neuropsychiatric disorders such as Parkinson's disease, substance use disorders, depression, and schizophrenia. Understanding the developmental processes that generate midbrain dopaminergic neurons will facilitate the generation of dopaminergic neurons from stem cells for cell replacement therapies to substitute degenerating cells in Parkinson's disease patients and will forward our understanding on how functional diversity of dopaminergic neurons in the adult brain is established. Midbrain dopaminergic neurons develop in a multistep process. Following the induction of the ventral midbrain, a distinct dopaminergic progenitor domain is specified and dopaminergic progenitors undergo proliferation, neurogenesis, and differentiation. Subsequently, midbrain dopaminergic neurons acquire a mature dopaminergic phenotype, migrate to their final position and establish projections and connections to their forebrain targets. This review will discuss insights gained on the signaling network of secreted molecules, cell surface receptors, and transcription factors that regulate specification and differentiation of midbrain dopaminergic progenitors and neurons, from the induction of the ventral midbrain to the migration of dopaminergic neurons. For further resources related to this article, please visit the WIREs website. CONFLICT OF INTEREST The authors have declared no conflicts of interest for this article.
Collapse
Affiliation(s)
- Sandra Blaess
- Institute of Reconstructive Neurobiology, Life and Brain Center, University of Bonn, Bonn, Germany
| | | |
Collapse
|
69
|
Poulin JF, Zou J, Drouin-Ouellet J, Kim KYA, Cicchetti F, Awatramani RB. Defining midbrain dopaminergic neuron diversity by single-cell gene expression profiling. Cell Rep 2014; 9:930-43. [PMID: 25437550 DOI: 10.1016/j.celrep.2014.10.008] [Citation(s) in RCA: 223] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 08/07/2014] [Accepted: 09/30/2014] [Indexed: 11/19/2022] Open
Abstract
Effective approaches to neuropsychiatric disorders require detailed understanding of the cellular composition and circuitry of the complex mammalian brain. Here, we present a paradigm for deconstructing the diversity of neurons defined by a specific neurotransmitter using a microfluidic dynamic array to simultaneously evaluate the expression of 96 genes in single neurons. With this approach, we successfully identified multiple molecularly distinct dopamine neuron subtypes and localized them in the adult mouse brain. To validate the anatomical and functional correlates of molecular diversity, we provide evidence that one Vip+ subtype, located in the periaqueductal region, has a discrete projection field within the extended amygdala. Another Aldh1a1+ subtype, located in the substantia nigra, is especially vulnerable in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of Parkinson's disease. Overall, this rapid, cost-effective approach enables the identification and classification of multiple dopamine neuron subtypes, with distinct molecular, anatomical, and functional properties.
Collapse
Affiliation(s)
- Jean-Francois Poulin
- Department of Neurology and the Center for Genetic Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Jian Zou
- Department of Neurology and the Center for Genetic Medicine, Northwestern University, Chicago, IL 60611, USA
| | | | - Kwang-Youn A Kim
- Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Francesca Cicchetti
- Centre de Recherche du CHU de Québec, Axe Neurosciences and Université Laval, Québec, QC G1V 4G2, Canada
| | - Rajeshwar B Awatramani
- Department of Neurology and the Center for Genetic Medicine, Northwestern University, Chicago, IL 60611, USA.
| |
Collapse
|
70
|
Panman L, Papathanou M, Laguna A, Oosterveen T, Volakakis N, Acampora D, Kurtsdotter I, Yoshitake T, Kehr J, Joodmardi E, Muhr J, Simeone A, Ericson J, Perlmann T. Sox6 and Otx2 control the specification of substantia nigra and ventral tegmental area dopamine neurons. Cell Rep 2014; 8:1018-25. [PMID: 25127144 DOI: 10.1016/j.celrep.2014.07.016] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 06/24/2014] [Accepted: 07/14/2014] [Indexed: 10/24/2022] Open
Abstract
Distinct midbrain dopamine (mDA) neuron subtypes are found in the substantia nigra pars compacta (SNc) and the ventral tegmental area (VTA), but it is mainly SNc neurons that degenerate in Parkinson's disease. Interest in how mDA neurons develop has been stimulated by the potential use of stem cells in therapy or disease modeling. However, very little is known about how specific dopaminergic subtypes are generated. Here, we show that the expression profiles of the transcription factors Sox6, Otx2, and Nolz1 define subpopulations of mDA neurons already at the neural progenitor cell stage. After cell-cycle exit, Sox6 selectively localizes to SNc neurons, while Otx2 and Nolz1 are expressed in a subset of VTA neurons. Importantly, Sox6 ablation leads to decreased expression of SNc markers and a corresponding increase in VTA markers, while Otx2 ablation has the opposite effect. Moreover, deletion of Sox6 affects striatal innervation and dopamine levels. We also find reduced Sox6 levels in Parkinson's disease patients. These findings identify Sox6 as a determinant of SNc neuron development and should facilitate the engineering of relevant mDA neurons for cell therapy and disease modeling.
Collapse
Affiliation(s)
- Lia Panman
- Ludwig Institute for Cancer Research, 17177 Stockholm, Sweden; MRC Toxicology Unit, Leicester LE1 9HN, UK.
| | | | - Ariadna Laguna
- Ludwig Institute for Cancer Research, 17177 Stockholm, Sweden; Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | | | | | - Dario Acampora
- Institute of Genetics and Biophysics "A. Buzzati-Traverso," CNR, 80131 Naples, Italy; IRCCS Neuromed, Pozzilli IS 86077, Italy
| | - Idha Kurtsdotter
- Ludwig Institute for Cancer Research, 17177 Stockholm, Sweden; Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Takashi Yoshitake
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Jan Kehr
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Eliza Joodmardi
- Ludwig Institute for Cancer Research, 17177 Stockholm, Sweden
| | - Jonas Muhr
- Ludwig Institute for Cancer Research, 17177 Stockholm, Sweden; Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Antonio Simeone
- Institute of Genetics and Biophysics "A. Buzzati-Traverso," CNR, 80131 Naples, Italy; IRCCS Neuromed, Pozzilli IS 86077, Italy
| | - Johan Ericson
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Thomas Perlmann
- Ludwig Institute for Cancer Research, 17177 Stockholm, Sweden; Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden.
| |
Collapse
|
71
|
Mesman S, von Oerthel L, Smidt MP. Mesodiencephalic dopaminergic neuronal differentiation does not involve GLI2A-mediated SHH-signaling and is under the direct influence of canonical WNT signaling. PLoS One 2014; 9:e97926. [PMID: 24865218 PMCID: PMC4035267 DOI: 10.1371/journal.pone.0097926] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 04/27/2014] [Indexed: 12/19/2022] Open
Abstract
Sonic Hedgehog (SHH) and WNT proteins are key regulators in many developmental processes, like embryonic patterning and brain development. In the brain, SHH is expressed in a gradient starting in the floor plate (FP) progressing ventrally in the midbrain, where it is thought to be involved in the development and specification of mesodiencephalic dopaminergic (mdDA) neurons. GLI2A-mediated SHH-signaling induces the expression of Gli1, which is inhibited when cells start expressing SHH themselves. To determine whether mdDA neurons receive GLI2A-mediated SHH-signaling during differentiation, we used a BAC-transgenic mouse model expressing eGFP under the control of the Gli1 promoter. This mouse-model allowed for mapping of GLI2A-mediated SHH-signaling temporal and spatial in the mouse midbrain. Since mdDA neurons are born from E10.5, peaking at E11.0–E12.0, we examined Gli1-eGFP embryos at E11.5, E12.5, and E13.5, indicating whether Gli1 was induced before or during mdDA development and differentiation. Our data indicate that GLI2A-mediated SHH-signaling is not involved in mdDA neuronal differentiation. However, it appears to be involved in the differentiation of neurons which make up a subset of the red nucleus (RN). In order to detect whether mdDA neuronal differentiation may be under the control of canonical WNT-signaling, we used a transgenic mouse-line expressing LacZ under the influence of stable β-catenin. Here, we show that TH+ neurons of the midbrain receive canonical WNT-signaling during differentiation. Therefore, we suggest that early SHH-signaling is indirectly involved in mdDA development through early patterning of the midbrain area, whereas canonical WNT-signaling is directly involved in the differentiation of the mdDA neuronal population.
Collapse
Affiliation(s)
- Simone Mesman
- Swammerdam Institute for Life Sciences, CNS, FNWI University of Amsterdam, Amsterdam, The Netherlands
| | - Lars von Oerthel
- Swammerdam Institute for Life Sciences, CNS, FNWI University of Amsterdam, Amsterdam, The Netherlands
| | - Marten P. Smidt
- Swammerdam Institute for Life Sciences, CNS, FNWI University of Amsterdam, Amsterdam, The Netherlands
- * E-mail:
| |
Collapse
|
72
|
Bodea GO, Spille JH, Abe P, Andersson AS, Acker-Palmer A, Stumm R, Kubitscheck U, Blaess S. Reelin and CXCL12 regulate distinct migratory behaviors during the development of the dopaminergic system. Development 2014; 141:661-73. [PMID: 24449842 DOI: 10.1242/dev.099937] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The proper functioning of the dopaminergic system requires the coordinated formation of projections extending from dopaminergic neurons in the substantia nigra (SN), ventral tegmental area (VTA) and retrorubral field to a wide array of forebrain targets including the striatum, nucleus accumbens and prefrontal cortex. The mechanisms controlling the assembly of these distinct dopaminergic cell clusters are not well understood. Here, we have investigated in detail the migratory behavior of dopaminergic neurons giving rise to either the SN or the medial VTA using genetic inducible fate mapping, ultramicroscopy, time-lapse imaging, slice culture and analysis of mouse mutants. We demonstrate that neurons destined for the SN migrate first radially and then tangentially, whereas neurons destined for the medial VTA undergo primarily radial migration. We show that tangentially migrating dopaminergic neurons express the components of the reelin signaling pathway, whereas dopaminergic neurons in their initial, radial migration phase express CXC chemokine receptor 4 (CXCR4), the receptor for the chemokine CXC motif ligand 12 (CXCL12). Perturbation of reelin signaling interferes with the speed and orientation of tangentially, but not radially, migrating dopaminergic neurons and results in severe defects in the formation of the SN. By contrast, CXCR4/CXCL12 signaling modulates the initial migration of dopaminergic neurons. With this study, we provide the first molecular and functional characterization of the distinct migratory pathways taken by dopaminergic neurons destined for SN and VTA, and uncover mechanisms that regulate different migratory behaviors of dopaminergic neurons.
Collapse
Affiliation(s)
- Gabriela Oana Bodea
- Institute of Reconstructive Neurobiology, Life and Brain Center, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany
| | | | | | | | | | | | | | | |
Collapse
|
73
|
Novel insights into the development and maintenance of the blood-brain barrier. Cell Tissue Res 2014; 355:687-99. [PMID: 24590145 PMCID: PMC3972432 DOI: 10.1007/s00441-014-1811-2] [Citation(s) in RCA: 211] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 01/13/2014] [Indexed: 01/20/2023]
Abstract
The blood-brain barrier (BBB) is essential for maintaining homeostasis within the central nervous system (CNS) and is a prerequisite for proper neuronal function. The BBB is localized to microvascular endothelial cells that strictly control the passage of metabolites into and out of the CNS. Complex and continuous tight junctions and lack of fenestrae combined with low pinocytotic activity make the BBB endothelium a tight barrier for water soluble moleucles. In combination with its expression of specific enzymes and transport molecules, the BBB endothelium is unique and distinguishable from all other endothelial cells in the body. During embryonic development, the CNS is vascularized by angiogenic sprouting from vascular networks originating outside of the CNS in a precise spatio-temporal manner. The particular barrier characteristics of BBB endothelial cells are induced during CNS angiogenesis by cross-talk with cellular and acellular elements within the developing CNS. In this review, we summarize the currently known cellular and molecular mechanisms mediating brain angiogenesis and introduce more recently discovered CNS-specific pathways (Wnt/β-catenin, Norrin/Frizzled4 and hedgehog) and molecules (GPR124) that are crucial in BBB differentiation and maturation. Finally, based on observations that BBB dysfunction is associated with many human diseases such as multiple sclerosis, stroke and brain tumors, we discuss recent insights into the molecular mechanisms involved in maintaining barrier characteristics in the mature BBB endothelium.
Collapse
|
74
|
Stepp MA, Zieske JD, Trinkaus-Randall V, Kyne BM, Pal-Ghosh S, Tadvalkar G, Pajoohesh-Ganji A. Wounding the cornea to learn how it heals. Exp Eye Res 2014; 121:178-93. [PMID: 24607489 DOI: 10.1016/j.exer.2014.02.007] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 02/07/2014] [Accepted: 02/10/2014] [Indexed: 12/12/2022]
Abstract
Corneal wound healing studies have a long history and rich literature that describes the data obtained over the past 70 years using many different species of animals and methods of injury. These studies have lead to reduced suffering and provided clues to treatments that are now helping patients live more productive lives. In spite of the progress made, further research is required since blindness and reduced quality of life due to corneal scarring still happens. The purpose of this review is to summarize what is known about different types of wound and animal models used to study corneal wound healing. The subject of corneal wound healing is broad and includes chemical and mechanical wound models. This review focuses on mechanical injury models involving debridement and keratectomy wounds to reflect the authors' expertise.
Collapse
Affiliation(s)
- Mary Ann Stepp
- Department of Anatomy and Regenerative Biology, The George Washington University Medical Center, Washington, DC 20037, USA; Department of Ophthalmology, The George Washington University Medical Center, Washington, DC 20037, USA.
| | - James D Zieske
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114-2500, USA
| | - Vickery Trinkaus-Randall
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA 02118, USA; Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Briana M Kyne
- Department of Anatomy and Regenerative Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Sonali Pal-Ghosh
- Department of Anatomy and Regenerative Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Gauri Tadvalkar
- Department of Anatomy and Regenerative Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Ahdeah Pajoohesh-Ganji
- Department of Anatomy and Regenerative Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| |
Collapse
|
75
|
Arenas E. Wnt signaling in midbrain dopaminergic neuron development and regenerative medicine for Parkinson's disease. J Mol Cell Biol 2014; 6:42-53. [DOI: 10.1093/jmcb/mju001] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
|
76
|
Anderegg A, Lin HP, Chen JA, Caronia-Brown G, Cherepanova N, Yun B, Joksimovic M, Rock J, Harfe BD, Johnson R, Awatramani R. An Lmx1b-miR135a2 regulatory circuit modulates Wnt1/Wnt signaling and determines the size of the midbrain dopaminergic progenitor pool. PLoS Genet 2013; 9:e1003973. [PMID: 24348261 PMCID: PMC3861205 DOI: 10.1371/journal.pgen.1003973] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 10/09/2013] [Indexed: 11/19/2022] Open
Abstract
MicroRNAs regulate gene expression in diverse physiological scenarios. Their role in the control of morphogen related signaling pathways has been less studied, particularly in the context of embryonic Central Nervous System (CNS) development. Here, we uncover a role for microRNAs in limiting the spatiotemporal range of morphogen expression and function. Wnt1 is a key morphogen in the embryonic midbrain, and directs proliferation, survival, patterning and neurogenesis. We reveal an autoregulatory negative feedback loop between the transcription factor Lmx1b and a newly characterized microRNA, miR135a2, which modulates the extent of Wnt1/Wnt signaling and the size of the dopamine progenitor domain. Conditional gain of function studies reveal that Lmx1b promotes Wnt1/Wnt signaling, and thereby increases midbrain size and dopamine progenitor allocation. Conditional removal of Lmx1b has the opposite effect, in that expansion of the dopamine progenitor domain is severely compromised. Next, we provide evidence that microRNAs are involved in restricting dopamine progenitor allocation. Conditional loss of Dicer1 in embryonic stem cells (ESCs) results in expanded Lmx1a/b+ progenitors. In contrast, forced elevation of miR135a2 during an early window in vivo phenocopies the Lmx1b conditional knockout. When En1::Cre, but not Shh::Cre or Nes::Cre, is used for recombination, the expansion of Lmx1a/b+ progenitors is selectively reduced. Bioinformatics and luciferase assay data suggests that miR135a2 targets Lmx1b and many genes in the Wnt signaling pathway, including Ccnd1, Gsk3b, and Tcf7l2. Consistent with this, we demonstrate that this mutant displays reductions in the size of the Lmx1b/Wnt1 domain and range of canonical Wnt signaling. We posit that microRNA modulation of the Lmx1b/Wnt axis in the early midbrain/isthmus could determine midbrain size and allocation of dopamine progenitors. Since canonical Wnt activity has recently been recognized as a key ingredient for programming ESCs towards a dopaminergic fate in vitro, these studies could impact the rational design of such protocols.
Collapse
Affiliation(s)
- Angela Anderegg
- Northwestern University Feinberg School of Medicine, Department of Neurology and Center for Genetic Medicine, Chicago, Illinois, United States of America
| | - Hsin-Pin Lin
- Northwestern University Feinberg School of Medicine, Department of Neurology and Center for Genetic Medicine, Chicago, Illinois, United States of America
| | - Jun-An Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Giuliana Caronia-Brown
- Northwestern University Feinberg School of Medicine, Department of Neurology and Center for Genetic Medicine, Chicago, Illinois, United States of America
| | - Natalya Cherepanova
- Northwestern University Feinberg School of Medicine, Department of Neurology and Center for Genetic Medicine, Chicago, Illinois, United States of America
| | - Beth Yun
- Northwestern University Feinberg School of Medicine, Department of Neurology and Center for Genetic Medicine, Chicago, Illinois, United States of America
| | - Milan Joksimovic
- Northwestern University Feinberg School of Medicine, Department of Neurology and Center for Genetic Medicine, Chicago, Illinois, United States of America
| | - Jason Rock
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, United States of America
| | - Brian D. Harfe
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, United States of America
| | - Randy Johnson
- Department of Biochemistry and Molecular Biology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Rajeshwar Awatramani
- Northwestern University Feinberg School of Medicine, Department of Neurology and Center for Genetic Medicine, Chicago, Illinois, United States of America
- * E-mail:
| |
Collapse
|
77
|
Wurst W, Prakash N. Wnt1-regulated genetic networks in midbrain dopaminergic neuron development. J Mol Cell Biol 2013; 6:34-41. [DOI: 10.1093/jmcb/mjt046] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
78
|
Joksimovic M, Awatramani R. Wnt/ -catenin signaling in midbrain dopaminergic neuron specification and neurogenesis. J Mol Cell Biol 2013; 6:27-33. [DOI: 10.1093/jmcb/mjt043] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
|
79
|
Smits SM, von Oerthel L, Hoekstra EJ, Burbach JPH, Smidt MP. Molecular marker differences relate to developmental position and subsets of mesodiencephalic dopaminergic neurons. PLoS One 2013; 8:e76037. [PMID: 24116087 PMCID: PMC3792114 DOI: 10.1371/journal.pone.0076037] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 08/23/2013] [Indexed: 12/02/2022] Open
Abstract
The development of mesodiencephalic dopaminergic (mdDA) neurons located in the substantia nigra compacta (SNc) and ventral tegmental area (VTA) follow a number of stages marked by distinct events. After preparation of the region by signals that provide induction and patterning, several transcription factors have been identified, which are involved in specifying the neuronal fate of these cells. The specific vulnerability of SNc neurons is thought to root in these specific developmental programs. The present study examines the positions of young postmitotic mdDA neurons to relate developmental position to mdDA subset specific markers. MdDA neurons were mapped relative to the neuromeric domains (prosomeres 1-3 (P1-3), midbrain, and hindbrain) as well as the longitudinal subdivisions (floor plate, basal plate, alar plate), as proposed by the prosomeric model. We found that postmitotic mdDA neurons are located mainly in the floorplate domain and very few in slightly more lateral domains. Moreover, mdDA neurons are present along a large proportion of the anterior/posterior axis extending from the midbrain to P3 in the diencephalon. The specific positions relate to some extent to the presence of specific subset markers as Ahd2. In the adult stage more of such subsets specific expressed genes are present and may represent a molecular map defining molecularly distinct groups of mdDA neurons.
Collapse
Affiliation(s)
- Simone M. Smits
- Department of Neuroscience and Pharmacology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Lars von Oerthel
- Molecular Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
- Department of Neuroscience and Pharmacology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Elisa J. Hoekstra
- Molecular Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - J. Peter H Burbach
- Department of Neuroscience and Pharmacology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marten P. Smidt
- Molecular Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
- Department of Neuroscience and Pharmacology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
- * E-mail:
| |
Collapse
|
80
|
Dissecting the diversity of midbrain dopamine neurons. Trends Neurosci 2013; 36:336-42. [DOI: 10.1016/j.tins.2013.03.003] [Citation(s) in RCA: 261] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 03/11/2013] [Accepted: 03/14/2013] [Indexed: 11/17/2022]
|
81
|
Yang J, Brown A, Ellisor D, Paul E, Hagan N, Zervas M. Dynamic temporal requirement of Wnt1 in midbrain dopamine neuron development. Development 2013; 140:1342-52. [PMID: 23444360 DOI: 10.1242/dev.080630] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Wnt1-expressing progenitors generate midbrain dopamine (MbDA) and cerebellum (Cb) neurons in distinct temporal windows and from spatially discrete progenitor domains. It has been shown that Wnt1 and Lmx1a participate in a cross-regulatory loop that is utilized during MbDA neuron development. However, Wnt1 expression dynamically changes over time and precedes that of Lmx1a. The spatial and temporal requirements of Wnt1 in development and specifically its requirement for MbDA neurons remain to be determined. To address these issues, we generated a conditional Wnt1 allele and temporally deleted Wnt1 coupled with genetic lineage analysis. Using this approach, we show that patterning of the midbrain (Mb) and Cb by Wnt1 occurs between the one-somite and the six- to eight-somite stages and is solely dependent on Wnt1 function in the Mb, but not in the Cb. Interestingly, an En1-derived domain persists after the early deletion of Wnt1 and mutant cells express OTX2. However, the En1-derived Wnt1-mutant domain does not contain LMX1a-expressing progenitors, and MbDA neurons are depleted. Thus, we demonstrate an early requirement of Wnt1 for all MbDA neurons. Subsequently, we deleted Wnt1 in the ventral Mb and show a continued late requirement for Wnt1 in MbDA neuron development, but not in LMX1a-expressing progenitors. Specifically, Wnt1 deletion disrupts the birthdating of MbDA neurons and causes a depletion of MbDA neurons positioned medially and a concomitant expansion of MbDA neurons positioned laterally during embryogenesis. Collectively, our analyses resolve the spatial and temporal function of Wnt1 in Mb and Cb patterning and in MbDA neuron development in vivo.
Collapse
Affiliation(s)
- Jasmine Yang
- Department of Molecular Biology, Cell Biology and Biochemistry, Division of Biology and Medicine, Brown University, 70 Ship Street, Providence, RI 02903, USA
| | | | | | | | | | | |
Collapse
|
82
|
Miura P, Shenker S, Andreu-Agullo C, Westholm JO, Lai EC. Widespread and extensive lengthening of 3' UTRs in the mammalian brain. Genome Res 2013; 23:812-25. [PMID: 23520388 PMCID: PMC3638137 DOI: 10.1101/gr.146886.112] [Citation(s) in RCA: 248] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 02/26/2013] [Indexed: 11/25/2022]
Abstract
Remarkable advances in techniques for gene expression profiling have radically changed our knowledge of the transcriptome. Recently, the mammalian brain was reported to express many long intergenic noncoding (lincRNAs) from loci downstream from protein-coding genes. Our experimental tests failed to validate specific accumulation of lincRNA transcripts, and instead revealed strongly distal 3' UTRs generated by alternative cleavage and polyadenylation (APA). With this perspective in mind, we analyzed deep mammalian RNA-seq data using conservative criteria, and identified 2035 mouse and 1847 human genes that utilize substantially distal novel 3' UTRs. Each of these extends at least 500 bases past the most distal 3' termini available in Ensembl v65, and collectively they add 6.6 Mb and 5.1 Mb to the mRNA space of mouse and human, respectively. Extensive Northern analyses validated stable accumulation of distal APA isoforms, including transcripts bearing exceptionally long 3' UTRs (many >10 kb and some >18 kb in length). The Northern data further illustrate that the extensions we annotated were not due to unprocessed transcriptional run-off events. Global tissue comparisons revealed that APA events yielding these extensions were most prevalent in the mouse and human brain. Finally, these extensions collectively contain thousands of conserved miRNA binding sites, and these are strongly enriched for many well-studied neural miRNAs. Altogether, these new 3' UTR annotations greatly expand the scope of post-transcriptional regulatory networks in mammals, and have particular impact on the central nervous system.
Collapse
Affiliation(s)
- Pedro Miura
- Department of Developmental Biology, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Sol Shenker
- Department of Developmental Biology, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Celia Andreu-Agullo
- Department of Developmental Biology, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Jakub O. Westholm
- Department of Developmental Biology, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Eric C. Lai
- Department of Developmental Biology, Sloan-Kettering Institute, New York, New York 10065, USA
| |
Collapse
|
83
|
Tang M, Luo SX, Tang V, Huang EJ. Temporal and spatial requirements of Smoothened in ventral midbrain neuronal development. Neural Dev 2013; 8:8. [PMID: 23618354 PMCID: PMC3680293 DOI: 10.1186/1749-8104-8-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 04/05/2013] [Indexed: 11/11/2022] Open
Abstract
Background Several studies have indicated that Sonic hedgehog (Shh) regulates the expansion of dopaminergic (DA) progenitors and the subsequent generation of mature DA neurons. This prevailing view has been based primarily on in vitro culture results, and the exact in vivo function of Shh signaling in the patterning and neurogenesis of the ventral midbrain (vMB) remains unclear. Methods We characterized the transcriptional codes for the vMB progenitor domains, and correlated them with the expression patterns of Shh signaling effectors, including Shh, Smoothened, Patched, Gli1, Gli2 and Gli3. Results While Shh and its downstream effectors showed robust expression in the neurogenic niche for DA progenitors at embryonic day (E)8 to E8.5, their expression shifted to the lateral domains from E9.5 to E12.5. Consistent with this dynamic change, conditional mutants with region-specific removal of the Shh receptor Smoothened in the vMB progenitors (Shh-Cre;Smofl/fl) showed a transient reduction in DA progenitors and DA neurons at E10.5, but had more profound defects in neurons derived from the more lateral domains, including those in the red nucleus, oculomotor nucleus, and raphe nuclei. Conversely, constitutive activation of Smoothened signaling in vMB (Shh-Cre;SmoM2) showed transient expansion of the same progenitor population. To further characterize the nature of Shh-Smoothened signaling in vMB, we examined the BAT-GAL reporter and the expression of Wnt1 in vMB, and found that the antagonistic effects of Shh and Wnt signaling critically regulate the development of DA progenitors and DA neurons. Conclusion These results highlight previously unrecognized effects of Shh-Smoothened signaling in the region-specific neurogenesis within the vMB.
Collapse
Affiliation(s)
- Mianzhi Tang
- Department of Pathology, University of California San Francisco, San Francisco, CA 94143, USA
| | | | | | | |
Collapse
|
84
|
Ventura T, Manor R, Aflalo ED, Chalifa-Caspi V, Weil S, Sharabi O, Sagi A. Post-embryonic transcriptomes of the prawn Macrobrachium rosenbergii: multigenic succession through metamorphosis. PLoS One 2013; 8:e55322. [PMID: 23372848 PMCID: PMC3555924 DOI: 10.1371/journal.pone.0055322] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 12/21/2012] [Indexed: 12/03/2022] Open
Abstract
Like many metazoans, the freshwater prawn Macrobrachium rosenbergii begins its post-embryonic life with a set of morphologically distinct planktonic larval stages, followed by a benthic post-larval stage during which the maturing organism differs from the larvae both ecologically and physiologically. Understanding of the molecular basis underlying morphogenesis in crustaceans is limited to the observation that methyl farnesoate, the non-epoxidated form of the insect juvenile hormone, acts as the active crustacean juvenoid. Molt steroids were also linked to morphogenesis and several other molecular pathways, such as Hedgehog and Wnt, are known to underlie morphogenesis in all metazoans examined and, as such, are thought to do the same in crustaceans. Using next generation sequencing, we deep-sequenced the transcriptomes of several larval and post-larval stages. De novo assembly, followed by bioinformatics analysis, revealed that many novel transcripts are over-expressed in either larvae- or post-larvae-stage prawn, shedding light on the molecular basis underlying M. rosenbergii metamorphosis. Fast larval molting rates and periodic morphological changes were reflected in over-expression of transcripts annotated to the cell cycle, DNA replication and morphogenic pathways (i.e., Hedgehog and Wnt). Further characterization of transcripts assigned to morphogenic pathways by real-time RT-PCR reconfirmed their over-expression in larvae, albeit with a more complex expression pattern when examined in the individual developmental stages. The expression level of an orthologue of cytochrome P450, 15A1, known to epoxidize methyl farnesoate in insects, was increased in the late larval and early post-larval stages, in accordance with the role of methyl farnesoate in crustacean metamorphosis. This study exemplifies the applicability of a high-throughput sequencing approach for studying complex traits, including metamorphosis, providing new insight into this unexplored area of crustacean research.
Collapse
Affiliation(s)
- Tomer Ventura
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Rivka Manor
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Eliahu D. Aflalo
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Vered Chalifa-Caspi
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Simy Weil
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Omri Sharabi
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Amir Sagi
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- * E-mail:
| |
Collapse
|
85
|
Abstract
Sonic hedgehog (Shh) signaling is critical for various developmental processes including specification of the midbrain dopamine (mDA) neurons in the ventral mesencephalon (vMes). While the timing of Shh and its response gene Gli1 segregates mDA neurons, their overall lineage contribution to mDA neurons heavily overlaps. Here, we demonstrate that the same set of mDA neuron progenitors sequentially respond to Shh signaling (Gli1 expression), induce Shh expression, and then turn off Shh responsiveness. Thus, at any given developmental stage, cells rarely co-express Shh and Gli1. Using Shh(Cre:GFP) mice to delete the Smoothened receptor in the Shh pathway, we demonstrate that the loss of Shh signaling in Shh expressing cells results in a transient increase in proliferation and subsequent depletion of mDA neuron progenitors in the posterior vMes due to the facilitated cell cycle exit. Moreover, the change in duration of Shh signaling in vMes progenitors altered the timing of the contribution to the ventral tegmental area (VTA) and the substantia nigra pars compacta (SNc) mDA neurons. Taken together, our investigation on the relationship between the Shh-secreting and -responding cells revealed an intricate regulation of induction and cessation of Shh signaling that influences the distribution of mDA neurons in the VTA and SNc.
Collapse
Affiliation(s)
- Lindsay Hayes
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | | | | | | |
Collapse
|
86
|
Kauhausen J, Thompson LH, Parish CL. Cell intrinsic and extrinsic factors contribute to enhance neural circuit reconstruction following transplantation in Parkinsonian mice. J Physiol 2012; 591:77-91. [PMID: 23045338 DOI: 10.1113/jphysiol.2012.243063] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cell replacement therapy for Parkinson's disease has predominantly focused on ectopic transplantation of fetal dopamine (DA) neurons into the striatum as a means to restore neurotransmission, rather than homotopic grafts into the site of cell loss, which would require extensive axonal growth. However, ectopic grafts fail to restore important aspects of DA circuitry necessary for controlled basal ganglia output, and this may underlie the suboptimal and variable functional outcomes in patients. We recently showed that DA neurons in homotopic allografts of embryonic ventral mesencephalon (VM) can send long axonal projections along the nigrostriatal pathway in order to innervate forebrain targets, although the extent of striatal reinnervation remains substantially less than can be achieved with ectopic placement directly into the striatal target. Here, we examined the possible benefits of using younger VM donor tissue and over-expression of glial cell-derived neurotrophic factor (GDNF) in the striatal target to improve the degree of striatal innervation from homotopic grafts. Younger donor tissue, collected on embryonic day (E)10, generated 4-fold larger grafts with greater striatal targeting, compared to grafts generated from more conventional E12 donor VM. Over-expression of GDNF in the host brain also significantly increased DA axonal growth and striatal innervation. Furthermore, a notable increase in the number and proportion of A9 DA neurons, essential for functional recovery, was observed in younger donor grafts treated with GDNF. Behavioural testing confirmed functional integration of younger donor tissue and demonstrated that improved motor function could be attributed to both local midbrain and striatal innervation. Together, these findings suggest there is significant scope for further development of intra-nigral grafting as a restorative approach for Parkinson's disease.
Collapse
Affiliation(s)
- Jessica Kauhausen
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3010, Australia
| | | | | |
Collapse
|
87
|
Ellisor D, Rieser C, Voelcker B, Machan JT, Zervas M. Genetic dissection of midbrain dopamine neuron development in vivo. Dev Biol 2012; 372:249-62. [PMID: 23041116 DOI: 10.1016/j.ydbio.2012.09.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 09/10/2012] [Accepted: 09/23/2012] [Indexed: 11/27/2022]
Abstract
Midbrain dopamine (MbDA) neurons are partitioned into medial and lateral cohorts that control complex functions. However, the genetic underpinnings of MbDA neuron heterogeneity are unclear. While it is known that Wnt1-expressing progenitors contribute to MbDA neurons, the role of Wnt1 in MbDA neuron development in vivo is unresolved. We show that mice with a spontaneous point mutation in Wnt1 have a unique phenotype characterized by the loss of medial MbDA neurons concomitant with a severe depletion of Wnt1-expressing progenitors and diminished LMX1a-expressing progenitors. Wnt1 mutant embryos also have alterations in a hierarchical gene regulatory loop suggesting multiple gene involvement in the Wnt1 mutant MbDA neuron phenotype. To investigate this possibility, we conditionally deleted Gbx2, Fgf8, and En1/2 after their early role in patterning and asked whether these genetic manipulations phenocopied the depletion of MbDA neurons in Wnt1 mutants. The conditional deletion of Gbx2 did not result in re-positioning or distribution of MbDA neurons. The temporal deletion of Fgf8 did not result in the loss of either LMX1a-expressing progenitors nor the initial population of differentiated MbDA neurons, but did result in a complete loss of MbDA neurons at later stages. The temporal deletion and species specific manipulation of En1/2 demonstrated a continued and species specific role of Engrailed genes in MbDA neuron development. Notably, our conditional deletion experiments revealed phenotypes dissimilar to Wnt1 mutants indicating the unique role of Wnt1 in MbDA neuron development. By placing Wnt1, Fgf8, and En1/2 in the context of their temporal requirement for MbDA neuron development, we further deciphered the developmental program underpinning MbDA neuron progenitors.
Collapse
Affiliation(s)
- Debra Ellisor
- Department of Molecular Biology, Cell Biology and Biochemistry, Division of Biology and Medicine, Brown University, 70 Ship St., Providence, RI 02903, USA
| | | | | | | | | |
Collapse
|
88
|
Bayly RD, Brown CY, Agarwala S. A novel role for FOXA2 and SHH in organizing midbrain signaling centers. Dev Biol 2012; 369:32-42. [PMID: 22750257 DOI: 10.1016/j.ydbio.2012.06.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 06/06/2012] [Accepted: 06/20/2012] [Indexed: 02/04/2023]
Abstract
The floor plate (FP) is a midline signaling center, known to direct ventral cell fates and axon guidance in the neural tube. The recent identification of midbrain FP as a source of dopaminergic neurons has renewed interest in its specification and organization, which remain poorly understood. In this study, we have examined the chick midbrain and spinal FP and show that both can be partitioned into medial (MFP) and lateral (LFP) subdivisions. Although Hedgehog (HH) signaling is necessary and sufficient for LFP specification, it is not sufficient for MFP induction. By contrast, the transcription factor FOXA2 can execute the full midbrain and spinal cord FP program via HH-independent and dependent mechanisms. Interestingly, although HH-independent FOXA2 activity is necessary and sufficient for inducing MFP-specific gene expression (e.g., LMX1B, BMP7), it cannot confer ventral identity to midline cells without also turning on Sonic hedgehog (SHH). We also note that the signaling centers of the midbrain, the FP, roof plate (RP) and the midbrain-hindbrain boundary (MHB) are physically contiguous, with each expressing LMX1B and BMP7. Possibly as a result, SHH or FOXA2 misexpression can transform the MHB into FP and also suppress RP induction. Conversely, HH or FOXA2 knockdown expands the endogenous RP and transforms the MFP into a RP and/or MHB fate. Finally, combined HH blockade and FOXA2 misexpression in ventral midbrain induces LMX1B expression, which triggers the specification of the RP, rather than the MFP. Thus we identify HH-independent and dependent roles for FOXA2 in specifying the FP. In addition, we elucidate for the first time, a novel role for SHH in determining whether a midbrain signaling center will become the FP, MHB or RP.
Collapse
Affiliation(s)
- Roy D Bayly
- Institute for Cell and Molecular Biology, University of Texas at Austin, Austin, TX 78712-0248, USA
| | | | | |
Collapse
|
89
|
Achim K, Peltopuro P, Lahti L, Li J, Salminen M, Partanen J. Distinct developmental origins and regulatory mechanisms for GABAergic neurons associated with dopaminergic nuclei in the ventral mesodiencephalic region. Development 2012; 139:2360-70. [PMID: 22627282 DOI: 10.1242/dev.076380] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
GABAergic neurons in the ventral mesodiencephalic region are highly important for the function of dopaminergic pathways that regulate multiple aspects of behavior. However, development of these neurons is poorly understood. We recently showed that molecular regulation of differentiation of the GABAergic neurons associated with the dopaminergic nuclei in the ventral midbrain (VTA and SNpr) is distinct from the rest of midbrain, but the reason for this difference remained elusive. Here, we have analyzed the developmental origin of the VTA and SNpr GABAergic neurons by genetic fate mapping. We demonstrate that the majority of these GABAergic neurons originate outside the midbrain, from rhombomere 1, and move into the ventral midbrain only as postmitotic neuronal precursors. We further show that Gata2, Gata3 and Tal1 define a subpopulation of GABAergic precursors in ventral rhombomere 1. A failure in GABAergic neuron differentiation in this region correlates with loss of VTA and SNpr GABAergic neurons in Tal1 mutant mice. In contrast to midbrain, GABAergic neurons of the anterior SNpr in the diencephalon are not derived from the rhombomere 1. These results suggest unique migratory pathways for the precursors of important GABAergic neuron subpopulations, and provide the basis for understanding diversity within midbrain GABAergic neurons.
Collapse
Affiliation(s)
- Kaia Achim
- Department of Biosciences, PO Box 56, Viikinkaari 5, FIN00014-University of Helsinki, Helsinki, Finland
| | | | | | | | | | | |
Collapse
|
90
|
Bye CR, Thompson LH, Parish CL. Birth dating of midbrain dopamine neurons identifies A9 enriched tissue for transplantation into parkinsonian mice. Exp Neurol 2012; 236:58-68. [PMID: 22524988 DOI: 10.1016/j.expneurol.2012.04.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 04/02/2012] [Accepted: 04/07/2012] [Indexed: 01/08/2023]
Abstract
Clinical trials have provided proof of principle that new dopamine neurons isolated from the developing ventral midbrain and transplanted into the denervated striatum can functionally integrate and alleviate symptoms in Parkinson's disease patients. However, extensive variability across patients has been observed, ranging from long-term motor improvement to the absence of symptomatic relief and development of dyskinesias. Heterogeneity of the donor tissue is likely to be a contributing factor in the variable outcomes. Dissections of ventral midbrain used for transplantation will variously contain progenitors for different dopamine neuron subtypes as well as different neurotransmitter phenotypes. The overall impact of the resulting graft will be determined by the functional contribution from these different cell types. The A9 substantia nigra pars compacta dopamine neurons, for example, are known to be particularly important for motor recovery in animal models. Serotonergic neurons, on the other hand, have been implicated in unwanted dyskinesias. Currently little knowledge exists on how variables such as donor age, which have not been controlled for in clinical trials, will impact on the final neuronal composition of fetal grafts. Here we performed a birth dating study to identify the time-course of neurogenesis within the various ventral midbrain dopamine subpopulations in an effort to identify A9-enriched donor tissue for transplantation. The results show that A9 neurons precede the birth of A10 ventral tegmental area dopamine neurons. Subsequent grafting of younger ventral midbrain donor tissue revealed significantly larger grafts containing more mitotic dopamine neuroblasts compared to older donor grafts. These grafts were enriched with A9 neurons and showed significantly greater innervation of the target dorso-lateral striatum and DA release. Younger donor grafts also contained significantly less serotonergic neurons. These findings demonstrate the importance of standardized methods to improve cell therapy for Parkinson's disease and have significant implications for the generation and selectivity of dopamine neurons from stem cell based sources.
Collapse
Affiliation(s)
- Christopher R Bye
- Florey Neuroscience Institutes, The University of Melbourne, Parkville, Victoria 3010, Australia
| | | | | |
Collapse
|
91
|
Haddad-Tóvolli R, Heide M, Zhou X, Blaess S, Alvarez-Bolado G. Mouse thalamic differentiation: gli-dependent pattern and gli-independent prepattern. Front Neurosci 2012; 6:27. [PMID: 22371696 PMCID: PMC3283895 DOI: 10.3389/fnins.2012.00027] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Accepted: 02/08/2012] [Indexed: 12/17/2022] Open
Abstract
Sonic hedgehog (Shh) signaling is essential for thalamic development. The Gli transcription factors act downstream of Shh – while Gli2 is the major activator (GliA), Gli3 acts primarily as a repressor (GliR). The thalamus is remarkable among dorsal structures because of its proximity to the mid-diencephalic organizer, a unique dorsal Shh source. This lends complexity to the interactions between Shh, Gli2, and Gli3, suggesting the presence of a dorsal Gli activator which elsewhere is found only ventrally, and making the dissection of thalamic Gli functions particularly interesting. A current model based on mutant phenotypes in telencephalon and midbrain postulates a degree of reciprocal antagonism of Shh and Gli3 in dorsal brain regions. To approach the role of Gli factors in thalamic specification we first analyzed mice deficient in Gli2 or Gli3. In Gli2 mutants, the thalamus is small and poorly differentiated with the exception of the medial and intralaminar nuclei which, in contrast, are specifically and severely affected by Gli3 inactivation. Gbx2 expression is very reduced in the Gli3 mutant. Most thalamic nuclei are present in both mutants, although incompletely differentiated, as reflected by the loss of specific markers. The ventral posterior group, revealed by novel specific marker Hes1, is present in both mutants and extends axons to the telencephalon. To test the Gli3/Shh interaction we generated a novel mutant deficient in Gli3 and neuroepithelial Shh. The thalamus of the n-Shh/Gli3 double mutants is very large and very poorly differentiated except for a broad domain of Gbx2, Lhx2, and Calb2 expression. In utero electroporation experiments on wild type embryos suggest that a stage-specific factor acting early is responsible for this prepattern. We show that, in the thalamus, GliA acts downstream of Shh to specify pattern and size of the thalamic nuclei to the exception of the medial and intralaminar groups. Gli3A can partially substitute for Gli2A in the Gli2 mutant. GliR is essential for specification and growth of the medial and intralaminar nuclei, contributes to the specification of other thalamic nuclei and reduces thalamic size. GliA (from neuroepithelial Shh signaling) and GliR do not show reciprocal antagonism in the thalamus, and their joint abolition does not rescue the wild type phenotype.
Collapse
Affiliation(s)
- Roberta Haddad-Tóvolli
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, University of Heidelberg Heidelberg, Germany
| | | | | | | | | |
Collapse
|
92
|
Lahti L, Peltopuro P, Piepponen TP, Partanen J. Cell-autonomous FGF signaling regulates anteroposterior patterning and neuronal differentiation in the mesodiencephalic dopaminergic progenitor domain. Development 2012; 139:894-905. [PMID: 22278924 DOI: 10.1242/dev.071936] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The structure and projection patterns of adult mesodiencephalic dopaminergic (DA) neurons are one of the best characterized systems in the vertebrate brain. However, the early organization and development of these nuclei remain poorly understood. The induction of midbrain DA neurons requires sonic hedgehog (Shh) from the floor plate and fibroblast growth factor 8 (FGF8) from the isthmic organizer, but the way in which FGF8 regulates DA neuron development is unclear. We show that, during early embryogenesis, mesodiencephalic neurons consist of two distinct populations: a diencephalic domain, which is probably independent of isthmic FGFs; and a midbrain domain, which is dependent on FGFs. Within these domains, DA progenitors and precursors use partly different genetic programs. Furthermore, the diencephalic DA domain forms a distinct cell population, which also contains non-DA Pou4f1(+) cells. FGF signaling operates in proliferative midbrain DA progenitors, but is absent in postmitotic DA precursors. The loss of FGFR1/2-mediated signaling results in a maturation failure of the midbrain DA neurons and altered patterning of the midbrain floor. In FGFR mutants, the DA domain adopts characteristics that are typical for embryonic diencephalon, including the presence of Pou4f1(+) cells among TH(+) cells, and downregulation of genes typical of midbrain DA precursors. Finally, analyses of chimeric embryos indicate that FGF signaling regulates the development of the ventral midbrain cell autonomously.
Collapse
Affiliation(s)
- Laura Lahti
- Department of Biosciences, Division of Genetics, University of Helsinki, Helsinki, Finland
| | | | | | | |
Collapse
|
93
|
Alvarez-Bolado G, Paul FA, Blaess S. Sonic hedgehog lineage in the mouse hypothalamus: from progenitor domains to hypothalamic regions. Neural Dev 2012; 7:4. [PMID: 22264356 PMCID: PMC3292819 DOI: 10.1186/1749-8104-7-4] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Accepted: 01/20/2012] [Indexed: 12/31/2022] Open
Abstract
Background The hypothalamus is a brain region with essential functions for homeostasis and energy metabolism, and alterations of its development can contribute to pathological conditions in the adult, like hypertension, diabetes or obesity. However, due to the anatomical complexity of the hypothalamus, its development is not well understood. Sonic hedgehog (Shh) is a key developmental regulator gene expressed in a dynamic pattern in hypothalamic progenitor cells. To obtain insight into hypothalamic organization, we used genetic inducible fate mapping (GIFM) to map the lineages derived from Shh-expressing progenitor domains onto the four rostrocaudally arranged hypothalamic regions: preoptic, anterior, tuberal and mammillary. Results Shh-expressing progenitors labeled at an early stage (before embryonic day (E)9.5) contribute neurons and astrocytes to a large caudal area including the mammillary and posterior tuberal regions as well as tanycytes (specialized median eminence glia). Progenitors labeled at later stages (after E9.5) give rise to neurons and astrocytes of the entire tuberal region and in particular the ventromedial nucleus, but not to cells in the mammillary region and median eminence. At this stage, an additional Shh-expressing domain appears in the preoptic area and contributes mostly astrocytes to the hypothalamus. Shh-expressing progenitors do not contribute to the anterior region at any stage. Finally, we show a gradual shift from neurogenesis to gliogenesis, so that progenitors expressing Shh after E12.5 generate almost exclusively hypothalamic astrocytes. Conclusions We define a fate map of the hypothalamus, based on the dynamic expression of Shh in the hypothalamic progenitor zones. We provide evidence that the large neurogenic Shh-expressing progenitor domains of the ventral diencephalon are continuous with those of the midbrain. We demonstrate that the four classical transverse zones of the hypothalamus have clearly defined progenitor domains and that there is little or no cell mixing between the tuberal and anterior or the preoptic and anterior hypothalamus. Finally, we show that, in the tuberal hypothalamus, neurons destined for every mediolateral level are produced during a period of days, in conflict with the current 'three-wave' model of hypothalamic neurogenesis. Our work sets the stage for a deeper developmental analysis of this complex and important brain region.
Collapse
Affiliation(s)
- Gonzalo Alvarez-Bolado
- Department of Neuroanatomy, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany.
| | | | | |
Collapse
|
94
|
Joksimovic M, Patel M, Taketo MM, Johnson R, Awatramani R. Ectopic Wnt/beta-catenin signaling induces neurogenesis in the spinal cord and hindbrain floor plate. PLoS One 2012; 7:e30266. [PMID: 22276170 PMCID: PMC3261891 DOI: 10.1371/journal.pone.0030266] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 12/12/2011] [Indexed: 01/08/2023] Open
Abstract
The most ventral structure of the developing neural tube, the floor plate (FP), differs in neurogenic capacity along the neuraxis. The FP is largely non-neurogenic at the hindbrain and spinal cord levels, but generates large numbers of dopamine (mDA) neurons at the midbrain levels. Wnt1, and other Wnts are expressed in the ventral midbrain, and Wnt/beta catenin signaling can at least in part account for the difference in neurogenic capacity of the FP between midbrain and hindbrain levels. To further develop the hypothesis that canonical Wnt signaling promotes mDA specification and FP neurogenesis, we have generated a model wherein beta–catenin is conditionally stabilized throughout the FP. Here, we unambiguously show by fate mapping FP cells in this mutant, that the hindbrain and spinal cord FP are rendered highly neurogenic, producing large numbers of neurons. We reveal that a neurogenic hindbrain FP results in the altered settling pattern of neighboring precerebellar neuronal clusters. Moreover, in this mutant, mDA progenitor markers are induced throughout the rostrocaudal axis of the hindbrain FP, although TH+ mDA neurons are produced only in the rostral aspect of rhombomere (r)1. This is, at least in part, due to depressed Lmx1b levels by Wnt/beta catenin signaling; indeed, when Lmx1b levels are restored in this mutant, mDA are observed not only in rostral r1, but also at more caudal axial levels in the hindbrain, but not in the spinal cord. Taken together, these data elucidate both patterning and neurogenic functions of Wnt/beta catenin signaling in the FP, and thereby add to our understanding of the molecular logic of mDA specification and neurogenesis.
Collapse
Affiliation(s)
- Milan Joksimovic
- Department of Neurology and Center for Genetic Medicine, Feinberg Medical School, Northwestern University, Chicago, Illinois, United States of America
| | - Meera Patel
- Department of Neurology and Center for Genetic Medicine, Feinberg Medical School, Northwestern University, Chicago, Illinois, United States of America
| | - Makoto Mark Taketo
- Department of Pharmacology, Graduate School of Medicine, Kyoto University, Yoshida-Konoé-cho, Sakyo, Kyoto, Japan
| | - Randy Johnson
- Department of Biochemistry and Molecular Biology, University of Texas, M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Rajeshwar Awatramani
- Department of Neurology and Center for Genetic Medicine, Feinberg Medical School, Northwestern University, Chicago, Illinois, United States of America
- * E-mail:
| |
Collapse
|
95
|
Panman L, Perlmann T. Tracing lineages to uncover neuronal identity. BMC Biol 2011; 9:51. [PMID: 21771352 PMCID: PMC3141605 DOI: 10.1186/1741-7007-9-51] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 07/19/2011] [Indexed: 12/18/2022] Open
Abstract
Many previous studies have focused on understanding how midbrain dopamine neurons, which are implicated in many neurological conditions, are generated during embryogenesis. One of the remaining questions concerns how different dopamine neuron subtypes are specified. A recent paper in Neural Development has revealed features of a spatial and temporal lineage map that, together with other studies, begins to elucidate the developmental origin of distinct neuronal subtypes within the developing midbrain.
Collapse
Affiliation(s)
- Lia Panman
- Ludwig Institute for Cancer Research Ltd, Stockholm, Sweden
| | | |
Collapse
|