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Petrelli B, Oztürk A, Pind M, Ayele H, Fainsod A, Hicks GG. Genetically programmed retinoic acid deficiency during gastrulation phenocopies most known developmental defects due to acute prenatal alcohol exposure in FASD. Front Cell Dev Biol 2023; 11:1208279. [PMID: 37397253 PMCID: PMC10311642 DOI: 10.3389/fcell.2023.1208279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 06/05/2023] [Indexed: 07/04/2023] Open
Abstract
Fetal Alcohol Spectrum Disorder (FASD) arises from maternal consumption of alcohol during pregnancy affecting 2%-5% of the Western population. In Xenopus laevis studies, we showed that alcohol exposure during early gastrulation reduces retinoic acid (RA) levels at this critical embryonic stage inducing craniofacial malformations associated with Fetal Alcohol Syndrome. A genetic mouse model that induces a transient RA deficiency in the node during gastrulation is described. These mice recapitulate the phenotypes characteristic of prenatal alcohol exposure (PAE) suggesting a molecular etiology for the craniofacial malformations seen in children with FASD. Gsc +/Cyp26A1 mouse embryos have a reduced RA domain and expression in the developing frontonasal prominence region and delayed HoxA1 and HoxB1 expression at E8.5. These embryos also show aberrant neurofilament expression during cranial nerve formation at E10.5 and have significant FASD sentinel-like craniofacial phenotypes at E18.5. Gsc +/Cyp26A1 mice develop severe maxillary malocclusions in adulthood. Phenocopying the PAE-induced developmental malformations with a genetic model inducing RA deficiency during early gastrulation strongly supports the alcohol/vitamin A competition model as a major molecular etiology for the neurodevelopmental defects and craniofacial malformations seen in children with FASD.
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Affiliation(s)
- B. Petrelli
- Department of Biochemistry and Medical Genetics, Regenerative Medicine Program, Faculty of Medicine, University of Manitoba, Winnipeg, MB, Canada
| | - A. Oztürk
- Department of Biochemistry and Medical Genetics, Regenerative Medicine Program, Faculty of Medicine, University of Manitoba, Winnipeg, MB, Canada
| | - M. Pind
- Department of Biochemistry and Medical Genetics, Regenerative Medicine Program, Faculty of Medicine, University of Manitoba, Winnipeg, MB, Canada
| | - H. Ayele
- Department of Biochemistry and Medical Genetics, Regenerative Medicine Program, Faculty of Medicine, University of Manitoba, Winnipeg, MB, Canada
| | - A. Fainsod
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel–Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - G. G. Hicks
- Department of Biochemistry and Medical Genetics, Regenerative Medicine Program, Faculty of Medicine, University of Manitoba, Winnipeg, MB, Canada
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2
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Ananth MR, Rajebhosale P, Kim R, Talmage DA, Role LW. Basal forebrain cholinergic signalling: development, connectivity and roles in cognition. Nat Rev Neurosci 2023; 24:233-251. [PMID: 36823458 PMCID: PMC10439770 DOI: 10.1038/s41583-023-00677-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 01/18/2023] [Indexed: 02/25/2023]
Abstract
Acetylcholine plays an essential role in fundamental aspects of cognition. Studies that have mapped the activity and functional connectivity of cholinergic neurons have shown that the axons of basal forebrain cholinergic neurons innervate the pallium with far more topographical and functional organization than was historically appreciated. Together with the results of studies using new probes that allow release of acetylcholine to be detected with high spatial and temporal resolution, these findings have implicated cholinergic networks in 'binding' diverse behaviours that contribute to cognition. Here, we review recent findings on the developmental origins, connectivity and function of cholinergic neurons, and explore the participation of cholinergic signalling in the encoding of cognition-related behaviours.
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Affiliation(s)
- Mala R Ananth
- Section on Circuits, Synapses, and Molecular Signalling, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
| | - Prithviraj Rajebhosale
- Section on Genetics of Neuronal Signalling, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Ronald Kim
- Section on Genetics of Neuronal Signalling, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - David A Talmage
- Section on Genetics of Neuronal Signalling, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Lorna W Role
- Section on Circuits, Synapses, and Molecular Signalling, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
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3
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Udaykumar N, Zaidi MAA, Rai A, Sen J. CNKSR2, a downstream mediator of retinoic acid signaling, modulates the Ras/Raf/MEK pathway to regulate patterning and invagination of the chick forebrain roof plate. Development 2023; 150:286897. [PMID: 36734326 DOI: 10.1242/dev.200857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 01/03/2023] [Indexed: 02/04/2023]
Abstract
During embryonic development, the forebrain roof plate undergoes invagination, leading to separation of the cerebral hemispheres. Any defects in this process, in humans, lead to middle interhemispheric holoprosencephaly (MIH-HPE). In this study, we have identified a previously unreported downstream mediator of retinoic acid (RA) signaling, CNKSR2, which is expressed in the forebrain roof plate in the chick embryo. Knockdown of CNKSR2 affects invagination, cell proliferation and patterning of the roof plate, similar to the phenotypes observed upon inhibition of RA signaling. We further demonstrate that CNKSR2 functions by modulating the Ras/Raf/MEK signaling. This appears to be crucial for patterning of the forebrain roof plate and its subsequent invagination, leading to the formation of the cerebral hemispheres. Thus, a set of novel molecular players have been identified that regulate the morphogenesis of the avian forebrain.
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Affiliation(s)
- Niveda Udaykumar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016 Uttar Pradesh, India
| | - Mohd Ali Abbas Zaidi
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016 Uttar Pradesh, India
| | - Aishwarya Rai
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016 Uttar Pradesh, India
| | - Jonaki Sen
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016 Uttar Pradesh, India
- Mehta Family Center for Engineering in Medicine (MFCEM), Indian Institute of Technology Kanpur, Kanpur 208016, Uttar Pradesh, India
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Diacou R, Nandigrami P, Fiser A, Liu W, Ashery-Padan R, Cvekl A. Cell fate decisions, transcription factors and signaling during early retinal development. Prog Retin Eye Res 2022; 91:101093. [PMID: 35817658 PMCID: PMC9669153 DOI: 10.1016/j.preteyeres.2022.101093] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 06/02/2022] [Accepted: 06/03/2022] [Indexed: 12/30/2022]
Abstract
The development of the vertebrate eyes is a complex process starting from anterior-posterior and dorso-ventral patterning of the anterior neural tube, resulting in the formation of the eye field. Symmetrical separation of the eye field at the anterior neural plate is followed by two symmetrical evaginations to generate a pair of optic vesicles. Next, reciprocal invagination of the optic vesicles with surface ectoderm-derived lens placodes generates double-layered optic cups. The inner and outer layers of the optic cups develop into the neural retina and retinal pigment epithelium (RPE), respectively. In vitro produced retinal tissues, called retinal organoids, are formed from human pluripotent stem cells, mimicking major steps of retinal differentiation in vivo. This review article summarizes recent progress in our understanding of early eye development, focusing on the formation the eye field, optic vesicles, and early optic cups. Recent single-cell transcriptomic studies are integrated with classical in vivo genetic and functional studies to uncover a range of cellular mechanisms underlying early eye development. The functions of signal transduction pathways and lineage-specific DNA-binding transcription factors are dissected to explain cell-specific regulatory mechanisms underlying cell fate determination during early eye development. The functions of homeodomain (HD) transcription factors Otx2, Pax6, Lhx2, Six3 and Six6, which are required for early eye development, are discussed in detail. Comprehensive understanding of the mechanisms of early eye development provides insight into the molecular and cellular basis of developmental ocular anomalies, such as optic cup coloboma. Lastly, modeling human development and inherited retinal diseases using stem cell-derived retinal organoids generates opportunities to discover novel therapies for retinal diseases.
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Affiliation(s)
- Raven Diacou
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Prithviraj Nandigrami
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Andras Fiser
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Wei Liu
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Ruth Ashery-Padan
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Ales Cvekl
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
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5
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Gur M, Bendelac-Kapon L, Shabtai Y, Pillemer G, Fainsod A. Reduced Retinoic Acid Signaling During Gastrulation Induces Developmental Microcephaly. Front Cell Dev Biol 2022; 10:844619. [PMID: 35372345 PMCID: PMC8967241 DOI: 10.3389/fcell.2022.844619] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 02/24/2022] [Indexed: 12/21/2022] Open
Abstract
Retinoic acid (RA) is a central signaling molecule regulating multiple developmental decisions during embryogenesis. Excess RA induces head malformations, primarily by expansion of posterior brain structures at the expense of anterior head regions, i.e., hindbrain expansion. Despite this extensively studied RA teratogenic effect, a number of syndromes exhibiting microcephaly, such as DiGeorge, Vitamin A Deficiency, Fetal Alcohol Syndrome, and others, have been attributed to reduced RA signaling. This causative link suggests a requirement for RA signaling during normal head development in all these syndromes. To characterize this novel RA function, we studied the involvement of RA in the early events leading to head formation in Xenopus embryos. This effect was mapped to the earliest RA biosynthesis in the embryo within the gastrula Spemann-Mangold organizer. Head malformations were observed when reduced RA signaling was induced in the endogenous Spemann-Mangold organizer and in the ectopic organizer of twinned embryos. Two embryonic retinaldehyde dehydrogenases, ALDH1A2 (RALDH2) and ALDH1A3 (RALDH3) are initially expressed in the organizer and subsequently mark the trunk and the migrating leading edge mesendoderm, respectively. Gene-specific knockdowns and CRISPR/Cas9 targeting show that RALDH3 is a key enzyme involved in RA production required for head formation. These observations indicate that in addition to the teratogenic effect of excess RA on head development, RA signaling also has a positive and required regulatory role in the early formation of the head during gastrula stages. These results identify a novel RA activity that concurs with its proposed reduction in syndromes exhibiting microcephaly.
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George SM, Lu F, Rao M, Leach LL, Gross JM. The retinal pigment epithelium: Development, injury responses, and regenerative potential in mammalian and non-mammalian systems. Prog Retin Eye Res 2021; 85:100969. [PMID: 33901682 DOI: 10.1016/j.preteyeres.2021.100969] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 03/23/2021] [Accepted: 04/07/2021] [Indexed: 12/13/2022]
Abstract
Diseases that result in retinal pigment epithelium (RPE) degeneration, such as age-related macular degeneration (AMD), are among the leading causes of blindness worldwide. Atrophic (dry) AMD is the most prevalent form of AMD and there are currently no effective therapies to prevent RPE cell death or restore RPE cells lost from AMD. An intriguing approach to treat AMD and other RPE degenerative diseases is to develop therapies focused on stimulating endogenous RPE regeneration. For this to become feasible, a deeper understanding of the mechanisms underlying RPE development, injury responses and regenerative potential is needed. In mammals, RPE regeneration is extremely limited; small lesions can be repaired by the expansion of adjacent RPE cells, but large lesions cannot be repaired as remaining RPE cells are unable to functionally replace lost RPE tissue. In some injury paradigms, RPE cells proliferate but do not regenerate a morphologically normal monolayer, while in others, proliferation is pathogenic and results in further disruption to the retina. This is in contrast to non-mammalian vertebrates, which possess tremendous RPE regenerative potential. Here, we discuss what is known about RPE formation during development in mammalian and non-mammalian vertebrates, we detail the processes by which RPE cells respond to injury, and we describe examples of RPE-to-retina and RPE-to-RPE regeneration in non-mammalian vertebrates. Finally, we outline barriers to RPE-dependent regeneration in mammals that could potentially be overcome to stimulate a regenerative response from the RPE.
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Affiliation(s)
- Stephanie M George
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Fangfang Lu
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA; Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Mishal Rao
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Lyndsay L Leach
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Jeffrey M Gross
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA; Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA.
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7
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Garland MA, Reynolds K, Zhou CJ. Environmental mechanisms of orofacial clefts. Birth Defects Res 2020; 112:1660-1698. [PMID: 33125192 PMCID: PMC7902093 DOI: 10.1002/bdr2.1830] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 10/07/2020] [Accepted: 10/13/2020] [Indexed: 12/11/2022]
Abstract
Orofacial clefts (OFCs) are among the most common birth defects and impart a significant burden on afflicted individuals and their families. It is increasingly understood that many nonsyndromic OFCs are a consequence of extrinsic factors, genetic susceptibilities, and interactions of the two. Therefore, understanding the environmental mechanisms of OFCs is important in the prevention of future cases. This review examines the molecular mechanisms associated with environmental factors that either protect against or increase the risk of OFCs. We focus on essential metabolic pathways, environmental signaling mechanisms, detoxification pathways, behavioral risk factors, and biological hazards that may disrupt orofacial development.
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Affiliation(s)
- Michael A. Garland
- Department of Biochemistry and Molecular Medicine, University of California at Davis, School of Medicine, Sacramento, CA 95817
- Institute for Pediatric Regenerative Medicine of Shriners Hospitals for Children, University of California at Davis, School of Medicine, Sacramento, CA 95817
| | - Kurt Reynolds
- Department of Biochemistry and Molecular Medicine, University of California at Davis, School of Medicine, Sacramento, CA 95817
- Institute for Pediatric Regenerative Medicine of Shriners Hospitals for Children, University of California at Davis, School of Medicine, Sacramento, CA 95817
- Biochemistry, Molecular, Cellular, and Developmental Biology (BMCDB) graduate group, University of California, Davis, CA 95616
| | - Chengji J. Zhou
- Department of Biochemistry and Molecular Medicine, University of California at Davis, School of Medicine, Sacramento, CA 95817
- Institute for Pediatric Regenerative Medicine of Shriners Hospitals for Children, University of California at Davis, School of Medicine, Sacramento, CA 95817
- Biochemistry, Molecular, Cellular, and Developmental Biology (BMCDB) graduate group, University of California, Davis, CA 95616
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8
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Reynolds K, Zhang S, Sun B, Garland MA, Ji Y, Zhou CJ. Genetics and signaling mechanisms of orofacial clefts. Birth Defects Res 2020; 112:1588-1634. [PMID: 32666711 DOI: 10.1002/bdr2.1754] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/11/2020] [Accepted: 06/15/2020] [Indexed: 12/31/2022]
Abstract
Craniofacial development involves several complex tissue movements including several fusion processes to form the frontonasal and maxillary structures, including the upper lip and palate. Each of these movements are controlled by many different factors that are tightly regulated by several integral morphogenetic signaling pathways. Subject to both genetic and environmental influences, interruption at nearly any stage can disrupt lip, nasal, or palate fusion and result in a cleft. Here, we discuss many of the genetic risk factors that may contribute to the presentation of orofacial clefts in patients, and several of the key signaling pathways and underlying cellular mechanisms that control lip and palate formation, as identified primarily through investigating equivalent processes in animal models, are examined.
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Affiliation(s)
- Kurt Reynolds
- Department of Biochemistry and Molecular Medicine, University of California Davis, School of Medicine, Sacramento, California, USA.,Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children-Northern California; University of California Davis, School of Medicine, Sacramento, California, USA.,Biochemistry, Molecular, Cellular, and Developmental Biology (BMCDB) Graduate Group, University of California, Davis, California, USA
| | - Shuwen Zhang
- Department of Biochemistry and Molecular Medicine, University of California Davis, School of Medicine, Sacramento, California, USA.,Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children-Northern California; University of California Davis, School of Medicine, Sacramento, California, USA
| | - Bo Sun
- Department of Biochemistry and Molecular Medicine, University of California Davis, School of Medicine, Sacramento, California, USA.,Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children-Northern California; University of California Davis, School of Medicine, Sacramento, California, USA
| | - Michael A Garland
- Department of Biochemistry and Molecular Medicine, University of California Davis, School of Medicine, Sacramento, California, USA.,Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children-Northern California; University of California Davis, School of Medicine, Sacramento, California, USA
| | - Yu Ji
- Department of Biochemistry and Molecular Medicine, University of California Davis, School of Medicine, Sacramento, California, USA.,Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children-Northern California; University of California Davis, School of Medicine, Sacramento, California, USA.,Biochemistry, Molecular, Cellular, and Developmental Biology (BMCDB) Graduate Group, University of California, Davis, California, USA
| | - Chengji J Zhou
- Department of Biochemistry and Molecular Medicine, University of California Davis, School of Medicine, Sacramento, California, USA.,Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children-Northern California; University of California Davis, School of Medicine, Sacramento, California, USA.,Biochemistry, Molecular, Cellular, and Developmental Biology (BMCDB) Graduate Group, University of California, Davis, California, USA
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9
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Roberts C. Regulating Retinoic Acid Availability during Development and Regeneration: The Role of the CYP26 Enzymes. J Dev Biol 2020; 8:jdb8010006. [PMID: 32151018 PMCID: PMC7151129 DOI: 10.3390/jdb8010006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 02/17/2020] [Accepted: 02/17/2020] [Indexed: 12/16/2022] Open
Abstract
This review focuses on the role of the Cytochrome p450 subfamily 26 (CYP26) retinoic acid (RA) degrading enzymes during development and regeneration. Cyp26 enzymes, along with retinoic acid synthesising enzymes, are absolutely required for RA homeostasis in these processes by regulating availability of RA for receptor binding and signalling. Cyp26 enzymes are necessary to generate RA gradients and to protect specific tissues from RA signalling. Disruption of RA homeostasis leads to a wide variety of embryonic defects affecting many tissues. Here, the function of CYP26 enzymes is discussed in the context of the RA signalling pathway, enzymatic structure and biochemistry, human genetic disease, and function in development and regeneration as elucidated from animal model studies.
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Affiliation(s)
- Catherine Roberts
- Developmental Biology of Birth Defects, UCL-GOS Institute of Child Health, 30 Guilford St, London WC1N 1EH, UK;
- Institute of Medical and Biomedical Education St George’s, University of London, Cranmer Terrace, Tooting, London SW17 0RE, UK
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Fainsod A, Bendelac-Kapon L, Shabtai Y. Fetal Alcohol Spectrum Disorder: Embryogenesis Under Reduced Retinoic Acid Signaling Conditions. Subcell Biochem 2020; 95:197-225. [PMID: 32297301 DOI: 10.1007/978-3-030-42282-0_8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Fetal Alcohol Spectrum Disorder (FASD) is a complex set of developmental malformations, neurobehavioral anomalies and mental disabilities induced by exposing human embryos to alcohol during fetal development. Several experimental models and a series of developmental and biochemical approaches have established a strong link between FASD and reduced retinoic acid (RA) signaling. RA signaling is involved in the regulation of numerous developmental decisions from patterning of the anterior-posterior axis, starting at gastrulation, to the differentiation of specific cell types within developing organs, to adult tissue homeostasis. Being such an important regulatory signal during embryonic development, mutations or environmental perturbations that affect the level, timing or location of the RA signal can induce multiple and severe developmental malformations. The evidence connecting human syndromes to reduced RA signaling is presented here and the resulting phenotypes are compared to FASD. Available data suggest that competition between ethanol clearance and RA biosynthesis is a major etiological component in FASD.
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Affiliation(s)
- Abraham Fainsod
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Ein Kerem, POB 12271, 9112102, Jerusalem, Israel.
| | - Liat Bendelac-Kapon
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Ein Kerem, POB 12271, 9112102, Jerusalem, Israel
| | - Yehuda Shabtai
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Ein Kerem, POB 12271, 9112102, Jerusalem, Israel
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Spampinato SF, Bortolotto V, Canonico PL, Sortino MA, Grilli M. Astrocyte-Derived Paracrine Signals: Relevance for Neurogenic Niche Regulation and Blood-Brain Barrier Integrity. Front Pharmacol 2019; 10:1346. [PMID: 31824311 PMCID: PMC6881379 DOI: 10.3389/fphar.2019.01346] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 10/24/2019] [Indexed: 01/12/2023] Open
Abstract
Astrocytes are essential for proper regulation of the central nervous system (CNS). Importantly, these cells are highly secretory in nature. Indeed they can release hundreds of molecules which play pivotal physiological roles in nervous tissues and whose abnormal regulation has been associated with several CNS disorders. In agreement with these findings, recent studies have provided exciting insights into the key contribution of astrocyte-derived signals in the pleiotropic functions of these cells in brain health and diseases. In the future, deeper analysis of the astrocyte secretome is likely to further increase our current knowledge on the full potential of these cells and their secreted molecules not only as active participants in pathophysiological events, but as pharmacological targets or even as therapeutics for neurological and psychiatric diseases. Herein we will highlight recent findings in our and other laboratories on selected molecules that are actively secreted by astrocytes and contribute in two distinct functions with pathophysiological relevance for the astroglial population: i) regulation of neural stem cells (NSCs) and their progeny within adult neurogenic niches; ii) modulation of the blood–brain barrier (BBB) integrity and function.
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Affiliation(s)
- Simona Federica Spampinato
- Section of Pharmacology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Valeria Bortolotto
- Laboratory of Neuroplasticity, Department of Pharmaceutical Sciences, University of Piemonte Orientale, Novara, Italy
| | - Pier Luigi Canonico
- Laboratory of Neuroplasticity, Department of Pharmaceutical Sciences, University of Piemonte Orientale, Novara, Italy
| | - Maria Angela Sortino
- Section of Pharmacology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Mariagrazia Grilli
- Laboratory of Neuroplasticity, Department of Pharmaceutical Sciences, University of Piemonte Orientale, Novara, Italy
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12
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Choi SA, An JH, Lee SH, Lee GH, Yang HJ, Jeong PS, Cha JJ, Lee S, Park YH, Song BS, Sim BW, Kim YH, Kim JS, Jin YB, Huh JW, Lee SR, Lee JH, Kim SU. Comparative Evaluation of Hormones and Hormone-Like Molecule in Lineage Specification of Human Induced Pluripotent Stem Cells. Int J Stem Cells 2019; 12:240-250. [PMID: 31242719 PMCID: PMC6657937 DOI: 10.15283/ijsc18137] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 05/10/2019] [Accepted: 05/25/2019] [Indexed: 12/14/2022] Open
Abstract
Background and Objectives Proficient differentiation of human pluripotent stem cells (hPSCs) into specific lineages is required for applications in regenerative medicine. A growing amount of evidences had implicated hormones and hormone-like molecules as critical regulators of proliferation and lineage specification during in vivo development. Therefore, a deeper understanding of the hormones and hormone-like molecules involved in cell fate decisions is critical for efficient and controlled differentiation of hPSCs into specific lineages. Thus, we functionally and quantitatively compared the effects of diverse hormones (estradiol 17-β (E2), progesterone (P4), and dexamethasone (DM)) and a hormone-like molecule (retinoic acid (RA)) on the regulation of hematopoietic and neural lineage specification. Methods and Results We used 10 nM E2, 3 µM P4, 10 nM DM, and 10 nM RA based on their functional in vivo developmental potential. The sex hormone E2 enhanced functional activity of hematopoietic progenitors compared to P4 and DM, whereas RA impaired hematopoietic differentiation. In addition, E2 increased CD34+CD45+ cells with progenitor functions, even in the CD43- population, a well-known hemogenic marker. RA exhibited lineage-biased potential, preferentially committing hPSCs toward the neural lineage while restricting the hematopoietic fate decision. Conclusions Our findings reveal unique cell fate potentials of E2 and RA treatment and provide valuable differentiation information that is essential for hPSC applications.
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Affiliation(s)
- Seon-A Choi
- Futuristic Animal Resource & Research Center (FARRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea
| | - Ju-Hyun An
- Futuristic Animal Resource & Research Center (FARRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, Korea
| | - Seung Hwan Lee
- Futuristic Animal Resource & Research Center (FARRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea
| | - Geun-Hui Lee
- Futuristic Animal Resource & Research Center (FARRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea
| | - Hae-Jun Yang
- Futuristic Animal Resource & Research Center (FARRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea
| | - Pil-Soo Jeong
- Futuristic Animal Resource & Research Center (FARRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea
| | - Jae-Jin Cha
- Futuristic Animal Resource & Research Center (FARRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea
| | - Sanghoon Lee
- Futuristic Animal Resource & Research Center (FARRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea
| | - Young-Ho Park
- Futuristic Animal Resource & Research Center (FARRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, Korea
| | - Bong-Seok Song
- Futuristic Animal Resource & Research Center (FARRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, Korea
| | - Bo-Woong Sim
- Futuristic Animal Resource & Research Center (FARRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea
| | - Young-Hyun Kim
- National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, Korea
| | - Ji-Su Kim
- National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, Korea.,Primate Resource Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup, Korea
| | - Yeung Bae Jin
- National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea
| | - Jae-Won Huh
- National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, Korea
| | - Sang-Rae Lee
- National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, Korea
| | - Jong-Hee Lee
- Futuristic Animal Resource & Research Center (FARRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea
| | - Sun-Uk Kim
- Futuristic Animal Resource & Research Center (FARRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea.,Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon, Korea
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13
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Friedl RM, Raja S, Metzler MA, Patel ND, Brittian KR, Jones SP, Sandell LL. RDH10 function is necessary for spontaneous fetal mouth movement that facilitates palate shelf elevation. Dis Model Mech 2019; 12:12/7/dmm039073. [PMID: 31300413 PMCID: PMC6679383 DOI: 10.1242/dmm.039073] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 06/06/2019] [Indexed: 12/15/2022] Open
Abstract
Cleft palate is a common birth defect, occurring in approximately 1 in 1000 live births worldwide. Known etiological mechanisms of cleft palate include defects within developing palate shelf tissues, defects in mandibular growth and defects in spontaneous fetal mouth movement. Until now, experimental studies directly documenting fetal mouth immobility as an underlying cause of cleft palate have been limited to models lacking neurotransmission. This study extends the range of anomalies directly demonstrated to have fetal mouth movement defects correlated with cleft palate. Here, we show that mouse embryos deficient in retinoic acid (RA) have mispatterned pharyngeal nerves and skeletal elements that block spontaneous fetal mouth movement in utero. Using X-ray microtomography, in utero ultrasound video, ex vivo culture and tissue staining, we demonstrate that proper retinoid signaling and pharyngeal patterning are crucial for the fetal mouth movement needed for palate formation. Embryos with deficient retinoid signaling were generated by stage-specific inactivation of retinol dehydrogenase 10 (Rdh10), a gene crucial for the production of RA during embryogenesis. The finding that cleft palate in retinoid deficiency results from a lack of fetal mouth movement might help elucidate cleft palate etiology and improve early diagnosis in human disorders involving defects of pharyngeal development. Summary: Fetal mouth immobility and defects in pharyngeal patterning underlie cleft palate in retinoid-deficient Rdh10 mutant mouse embryos.
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Affiliation(s)
- Regina M Friedl
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY 40202, USA
| | - Swetha Raja
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY 40202, USA
| | - Melissa A Metzler
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY 40202, USA
| | - Niti D Patel
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY 40202, USA
| | - Kenneth R Brittian
- Department of Medicine, Diabetes and Obesity Center, University of Louisville, Louisville, KY 40202, USA
| | - Steven P Jones
- Department of Medicine, Diabetes and Obesity Center, University of Louisville, Louisville, KY 40202, USA
| | - Lisa L Sandell
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY 40202, USA
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14
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Cibi DM, Mia MM, Guna Shekeran S, Yun LS, Sandireddy R, Gupta P, Hota M, Sun L, Ghosh S, Singh MK. Neural crest-specific deletion of Rbfox2 in mice leads to craniofacial abnormalities including cleft palate. eLife 2019; 8:45418. [PMID: 31241461 PMCID: PMC6663295 DOI: 10.7554/elife.45418] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 06/25/2019] [Indexed: 12/17/2022] Open
Abstract
Alternative splicing (AS) creates proteomic diversity from a limited size genome by generating numerous transcripts from a single protein-coding gene. Tissue-specific regulators of AS are essential components of the gene regulatory network, required for normal cellular function, tissue patterning, and embryonic development. However, their cell-autonomous function in neural crest development has not been explored. Here, we demonstrate that splicing factor Rbfox2 is expressed in the neural crest cells (NCCs), and deletion of Rbfox2 in NCCs leads to cleft palate and defects in craniofacial bone development. RNA-Seq analysis revealed that Rbfox2 regulates splicing and expression of numerous genes essential for neural crest/craniofacial development. We demonstrate that Rbfox2-TGF-β-Tak1 signaling axis is deregulated by Rbfox2 deletion. Furthermore, restoration of TGF-β signaling by Tak1 overexpression can rescue the proliferation defect seen in Rbfox2 mutants. We also identified a positive feedback loop in which TGF-β signaling promotes expression of Rbfox2 in NCCs. Abnormalities affecting the head and face – such as a cleft lip or palate – are among the most common of all birth defects. These tissues normally develop from cells in the embryo known as the neural crest cells, and specifically a subset of these cells called the cranial neural crest cells. Most cases of cleft lip or palate are linked back to genes that affect the biology of this group of cells. The list of genes implicated in the impaired development of cranial neural crest cells code for proteins with a wide range of different activities. Some encode transcription factors – proteins that switch genes on or off. Others code for chromatin remodeling factors, which control how the DNA is packed inside cells. However, the role of another group of proteins – the splicing factors – remains unclear and warrants further investigation. When a gene is switched on its genetic code is first copied into a short-lived molecule called a transcript. These transcripts are then edited to form templates to build proteins. Splicing is one way that a transcript can be edited, which involves different pieces of the transcript being cut out and the remaining pieces being pasted together to form alternative versions of the final template. Splicing factors control this process. Cibi et al. now show that neural crest cells from mice make a splicing factor called Rbfox2 and that deleting this gene for this protein from only these cells leads to mice with a cleft palate and defects in the bones of their head and face. Further analysis helped to identify the transcripts that are spliced by Rbfox2, and the effects that these splicing events have on gene activity in mouse tissues that develop from cranial neural crest cells. Cibi et al. went on to find a signaling pathway that was impaired in the mutant cells that lacked Rbfox2. Forcing the mutant cells to over-produce one of the proteins involved in this signaling pathway (a protein named Tak1) was enough to compensate for the some of the defects caused by a lack of Rbfox2, suggesting it acts downstream of the splicing regulator. Lastly, Cibi et al. showed that another protein in this signaling pathway, called TGF-β, acted to increase how much Rbfox2 was made by neural crest cells. Together these findings may be relevant in human disease studies, given that altered TGF-β signaling is a common feature in many birth defects seen in humans.
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Affiliation(s)
- Dasan Mary Cibi
- Program in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Masum M Mia
- Program in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Shamini Guna Shekeran
- Program in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Lim Sze Yun
- National Heart Research Institute, National Heart Center, Singapore, Singapore
| | - Reddemma Sandireddy
- Program in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Priyanka Gupta
- Program in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Monalisa Hota
- Program in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Lei Sun
- Program in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Sujoy Ghosh
- Program in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Manvendra K Singh
- Program in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, Singapore, Singapore.,National Heart Research Institute, National Heart Center, Singapore, Singapore
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15
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Petrelli B, Bendelac L, Hicks GG, Fainsod A. Insights into retinoic acid deficiency and the induction of craniofacial malformations and microcephaly in fetal alcohol spectrum disorder. Genesis 2019; 57:e23278. [DOI: 10.1002/dvg.23278] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 12/03/2018] [Accepted: 12/04/2018] [Indexed: 12/14/2022]
Affiliation(s)
- Berardino Petrelli
- Regenerative Medicine Program and the Department of Biochemistry & Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health SciencesUniversity of Manitoba Winnipeg Manitoba Canada
| | - Liat Bendelac
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel‐CanadaFaculty of Medicine, Hebrew University Jerusalem Israel
| | - Geoffrey G. Hicks
- Regenerative Medicine Program and the Department of Biochemistry & Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health SciencesUniversity of Manitoba Winnipeg Manitoba Canada
| | - Abraham Fainsod
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel‐CanadaFaculty of Medicine, Hebrew University Jerusalem Israel
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16
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Sharif Y, Jumah F, Coplan L, Krosser A, Sharif K, Tubbs RS. Blood brain barrier: A review of its anatomy and physiology in health and disease. Clin Anat 2018; 31:812-823. [PMID: 29637627 DOI: 10.1002/ca.23083] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 04/03/2018] [Indexed: 12/14/2022]
Abstract
The blood-brain barrier (BBB) is the principal regulator of transport of molecules and cells into and out of the central nervous system (CNS). It comprises endothelial cells, pericytes, immune cells, astrocytes, and basement membrane, collectively known as the neurovascular unit. The development of the barrier involves many complex pathways from all the progenitors of the neurovascular unit, but the timing of its formation is not entirely known. The coordinated activities of all the components of the neurovascular unit and other tissues ensure that materials required for growth and maintenance are allowed into the CNS while extraneous ones are excluded. This review summarizes current knowledge of the anatomy, development, and physiology of the BBB, and alterations that occur in disease conditions. Clin. Anat. 31:812-823, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Yousra Sharif
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Fareed Jumah
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Louis Coplan
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Alec Krosser
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Kassem Sharif
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - R Shane Tubbs
- Department of Anatomical Sciences, St. George's University, Grenada.,Seattle Science Foundation, Seattle, Washington
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17
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Cavodeassi F, Creuzet S, Etchevers HC. The hedgehog pathway and ocular developmental anomalies. Hum Genet 2018; 138:917-936. [PMID: 30073412 PMCID: PMC6710239 DOI: 10.1007/s00439-018-1918-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 07/24/2018] [Indexed: 12/18/2022]
Abstract
Mutations in effectors of the hedgehog signaling pathway are responsible for a wide variety of ocular developmental anomalies. These range from massive malformations of the brain and ocular primordia, not always compatible with postnatal life, to subtle but damaging functional effects on specific eye components. This review will concentrate on the effects and effectors of the major vertebrate hedgehog ligand for eye and brain formation, Sonic hedgehog (SHH), in tissues that constitute the eye directly and also in those tissues that exert indirect influence on eye formation. After a brief overview of human eye development, the many roles of the SHH signaling pathway during both early and later morphogenetic processes in the brain and then eye and periocular primordia will be evoked. Some of the unique molecular biology of this pathway in vertebrates, particularly ciliary signal transduction, will also be broached within this developmental cellular context.
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Affiliation(s)
- Florencia Cavodeassi
- Institute for Medical and Biomedical Education, St. George´s University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Sophie Creuzet
- Institut des Neurosciences Paris-Saclay (Neuro-PSI), UMR 9197, CNRS, Université Paris-Sud, 1 Avenue de la Terrasse, 91198, Gif-sur-Yvette Cedex, France
| | - Heather C Etchevers
- Aix-Marseille Univ, Marseille Medical Genetics (MMG), INSERM, Faculté de Médecine, 27 boulevard Jean Moulin, 13005, Marseille, France.
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18
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Haddad-Tóvolli R, Dragano NRV, Ramalho AFS, Velloso LA. Development and Function of the Blood-Brain Barrier in the Context of Metabolic Control. Front Neurosci 2017; 11:224. [PMID: 28484368 PMCID: PMC5399017 DOI: 10.3389/fnins.2017.00224] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 04/04/2017] [Indexed: 12/21/2022] Open
Abstract
Under physiological conditions, the brain consumes over 20% of the whole body energy supply. The blood-brain barrier (BBB) allows dynamic interactions between blood capillaries and the neuronal network in order to provide an adequate control of molecules that are transported in and out of the brain. Alterations in the BBB structure and function affecting brain accessibility to nutrients and exit of toxins are found in a number of diseases, which in turn may disturb brain function and nutrient signaling. In this review we explore the major advances obtained in the understanding of the BBB development and how its structure impacts on function. Furthermore, we focus on the particularities of the barrier permeability in the hypothalamus, its role in metabolic control and the potential impact of hypothalamic BBB abnormities in metabolic related diseases.
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Affiliation(s)
- Roberta Haddad-Tóvolli
- Laboratory of Cell Signaling and Obesity and Comorbidities Research Center, Faculty of Medical Sciences, University of CampinasCampinas, Brazil
| | | | | | - Licio A. Velloso
- Laboratory of Cell Signaling and Obesity and Comorbidities Research Center, Faculty of Medical Sciences, University of CampinasCampinas, Brazil
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19
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Metzler MA, Sandell LL. Enzymatic Metabolism of Vitamin A in Developing Vertebrate Embryos. Nutrients 2016; 8:E812. [PMID: 27983671 PMCID: PMC5188467 DOI: 10.3390/nu8120812] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 12/09/2016] [Accepted: 12/13/2016] [Indexed: 12/16/2022] Open
Abstract
Embryonic development is orchestrated by a small number of signaling pathways, one of which is the retinoic acid (RA) signaling pathway. Vitamin A is essential for vertebrate embryonic development because it is the molecular precursor of the essential signaling molecule RA. The level and distribution of RA signaling within a developing embryo must be tightly regulated; too much, or too little, or abnormal distribution, all disrupt embryonic development. Precise regulation of RA signaling during embryogenesis is achieved by proteins involved in vitamin A metabolism, retinoid transport, nuclear signaling, and RA catabolism. The reversible first step in conversion of the precursor vitamin A to the active retinoid RA is mediated by retinol dehydrogenase 10 (RDH10) and dehydrogenase/reductase (SDR family) member 3 (DHRS3), two related membrane-bound proteins that functionally activate each other to mediate the interconversion of retinol and retinal. Alcohol dehydrogenase (ADH) enzymes do not contribute to RA production under normal conditions during embryogenesis. Genes involved in vitamin A metabolism and RA catabolism are expressed in tissue-specific patterns and are subject to feedback regulation. Mutations in genes encoding these proteins disrupt morphogenesis of many systems in a developing embryo. Together these observations demonstrate the importance of vitamin A metabolism in regulating RA signaling during embryonic development in vertebrates.
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Affiliation(s)
- Melissa A Metzler
- Department of Molecular, Cellular and Craniofacial Biology, University of Louisville, Louisville, KY 40201, USA.
| | - Lisa L Sandell
- Department of Molecular, Cellular and Craniofacial Biology, University of Louisville, Louisville, KY 40201, USA.
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20
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Mammadova A, Zhou H, Carels CE, Von den Hoff JW. Retinoic acid signalling in the development of the epidermis, the limbs and the secondary palate. Differentiation 2016; 92:326-335. [DOI: 10.1016/j.diff.2016.05.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 04/20/2016] [Accepted: 05/02/2016] [Indexed: 01/06/2023]
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21
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Kumar A, Singh HN, Pareek V, Raza K, Dantham S, Kumar P, Mochan S, Faiq MA. A Possible Mechanism of Zika Virus Associated Microcephaly: Imperative Role of Retinoic Acid Response Element (RARE) Consensus Sequence Repeats in the Viral Genome. Front Hum Neurosci 2016; 10:403. [PMID: 27555815 PMCID: PMC4977292 DOI: 10.3389/fnhum.2016.00403] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 07/27/2016] [Indexed: 11/13/2022] Open
Abstract
Owing to the reports of microcephaly as a consistent outcome in the fetuses of pregnant women infected with ZIKV in Brazil, Zika virus (ZIKV)-microcephaly etiomechanistic relationship has recently been implicated. Researchers, however, are still struggling to establish an embryological basis for this interesting causal handcuff. The present study reveals robust evidence in favor of a plausible ZIKV-microcephaly cause-effect liaison. The rationale is based on: (1) sequence homology between ZIKV genome and the response element of an early neural tube developmental marker "retinoic acid" in human DNA and (2) comprehensive similarities between the details of brain defects in ZIKV-microcephaly and retinoic acid embryopathy. Retinoic acid is considered as the earliest factor for regulating anteroposterior axis of neural tube and positioning of structures in developing brain through retinoic acid response elements (RARE) consensus sequence (5'-AGGTCA-3') in promoter regions of retinoic acid-dependent genes. We screened genomic sequences of already reported virulent ZIKV strains (including those linked to microcephaly) and other viruses available in National Institute of Health genetic sequence database (GenBank) for the RARE consensus repeats and obtained results strongly bolstering our hypothesis that ZIKV strains associated with microcephaly may act through precipitation of dysregulation in retinoic acid-dependent genes by introducing extra stretches of RARE consensus sequence repeats in the genome of developing brain cells. Additional support to our hypothesis comes from our findings that screening of other viruses for RARE consensus sequence repeats is positive only for those known to display neurotropism and cause fetal brain defects (for which maternal-fetal transmission during developing stage may be required). The numbers of RARE sequence repeats appeared to match with the virulence of screened positive viruses. Although, bioinformatic evidence and embryological features are in favor of our hypothesis, additional studies including animal models are warranted to validate our proposition. Such studies are likely to unfold ZIKV-microcephaly association and may help in devising methods to combat it.
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Affiliation(s)
- Ashutosh Kumar
- Department of Anatomy, All India Institute of Medical Sciences New Delhi, India
| | - Himanshu N Singh
- Department of Biochemistry, All India Institute of Medical Sciences New Delhi, India
| | - Vikas Pareek
- Computational Neuroscience and Neuroimaging Division, National Brain Research Centre Manesar, India
| | - Khursheed Raza
- Department of Anatomy, All India Institute of Medical Sciences New Delhi, India
| | - Subrahamanyam Dantham
- Department of Biochemistry, All India Institute of Medical Sciences New Delhi, India
| | - Pavan Kumar
- Department of Anatomy, All India Institute of Medical Sciences New Delhi, India
| | - Sankat Mochan
- Department of Anatomy, All India Institute of Medical Sciences New Delhi, India
| | - Muneeb A Faiq
- Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical SciencesNew Delhi, India; Laboratory for Molecular Reproduction and Genetics, Department of Anatomy, All India Institute of medical SciencesNew Delhi, India; Medical Biotechnology Laboratory, Dr. B. R. Ambedkar Centre for Biomedical Research, University of DelhiNew Delhi, India
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22
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Kiecker C. The chick embryo as a model for the effects of prenatal exposure to alcohol on craniofacial development. Dev Biol 2016; 415:314-325. [PMID: 26777098 DOI: 10.1016/j.ydbio.2016.01.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 10/28/2015] [Accepted: 01/13/2016] [Indexed: 12/15/2022]
Abstract
Prenatal exposure to ethanol results in fetal alcohol spectrum disorder (FASD), a syndrome characterised by a broad range of clinical manifestations including craniofacial dysmorphologies and neurological defects. The characterisation of the mechanisms by which ethanol exerts its teratogenic effects is difficult due to the pleiotropic nature of its actions. Different experimental model systems have been employed to investigate the aetiology of FASD. Here, I will review studies using these different model organisms that have helped to elucidate how ethanol causes the craniofacial abnormalities characteristic of FASD. In these studies, ethanol was found to impair the prechordal plate-an important embryonic signalling centre-during gastrulation and to negatively affect the induction, migration and survival of the neural crest, a cell population that generates the cartilage and most of the bones of the skull. At the cellular level, ethanol appears to inhibit Sonic hedgehog signalling, alter levels of retionoic acid activity, trigger a Ca(2+)-CamKII-dependent pathway that antagonises WNT signalling, affect cytoskeletal dynamics and increase oxidative stress. Embryos of the domestic chick Gallus gallus domesticus have played a central role in developing a working model for the effects of ethanol on craniofacial development because they are easily accessible and because key steps in craniofacial development are particularly well established in the avian embryo. I will finish this review by highlighting some potential future avenues of fetal alcohol research.
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Affiliation(s)
- Clemens Kiecker
- MRC Centre for Developmental Neurobiology, 4th Floor, Hodgkin Building, Guy's Hospital Campus, King's College London, UK.
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23
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Glial influences on BBB functions and molecular players in immune cell trafficking. Biochim Biophys Acta Mol Basis Dis 2015; 1862:472-82. [PMID: 26454208 DOI: 10.1016/j.bbadis.2015.10.004] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Revised: 09/29/2015] [Accepted: 10/05/2015] [Indexed: 02/06/2023]
Abstract
The blood-brain barrier (BBB) constitutes an elaborate structure formed by specialized capillary endothelial cells, which together with pericytes and perivascular glial cells regulates the exchanges between the central nervous system (CNS) and the periphery. Intricate interactions between the different cellular constituents of the BBB are crucial in establishing a functional BBB and maintaining the delicate homeostasis of the CNS microenvironment. In this review, we discuss the role of astrocytes and microglia in inducing and maintaining barrier properties under physiological conditions as well as their involvement during neuroinflammatory pathologies. This article is part of a Special Issue entitled: Neuro Inflammation edited by Helga E. de Vries and Markus Schwaninger.
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24
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Abstract
The brain, which represents 2% of body mass but consumes 20% of body energy at rest, has a limited capacity to store energy and is therefore highly dependent on oxygen and glucose supply from the blood stream. Normal functioning of neural circuits thus relies on adequate matching between metabolic needs and blood supply. Moreover, not only does the brain need to be densely vascularized, it also requires a tightly controlled environment free of toxins and pathogens to provide the proper chemical composition for synaptic transmission and neuronal function. In this review, we focus on three major factors that ensure optimal brain perfusion and function: the patterning of vascular networks to efficiently deliver blood and nutrients, the function of the blood-brain barrier to maintain brain homeostasis, and the regulation of cerebral blood flow to adequately couple energy supply to neural function.
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Affiliation(s)
- Benjamin J Andreone
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115; , ,
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25
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Gupta S, Sen J. Retinoic acid signaling regulates development of the dorsal forebrain midline and the choroid plexus in the chick. Development 2015; 142:1293-8. [PMID: 25758461 DOI: 10.1242/dev.122390] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The developing forebrain roof plate (RP) contains a transient signaling center, perturbations in which have been linked to holoprosencephaly (HPE). Here, we describe a novel domain of retinoic acid (RA) signaling that is specific to the chick RP and demonstrate that RA signaling is sufficient for inducing characteristics of the RP in ectopic locations. We further demonstrate that, unlike what has been observed in the mouse, RA signaling is essential for invagination of the RP in chick, failure of which leads to an HPE-like phenotype. In addition, we found that RA exerts a negative influence on choroid plexus differentiation. Thus, our findings identify RA as a novel regulator of chick forebrain RP development.
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Affiliation(s)
- Sandeep Gupta
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India
| | - Jonaki Sen
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India
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26
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Samarut E, Fraher D, Laudet V, Gibert Y. ZebRA: An overview of retinoic acid signaling during zebrafish development. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1849:73-83. [DOI: 10.1016/j.bbagrm.2014.05.030] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 05/26/2014] [Accepted: 05/27/2014] [Indexed: 11/15/2022]
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Cunningham TJ, Duester G. Mechanisms of retinoic acid signalling and its roles in organ and limb development. Nat Rev Mol Cell Biol 2015; 16:110-23. [PMID: 25560970 PMCID: PMC4636111 DOI: 10.1038/nrm3932] [Citation(s) in RCA: 379] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Retinoic acid (RA) signalling has a central role during vertebrate development. RA synthesized in specific locations regulates transcription by interacting with nuclear RA receptors (RARs) bound to RA response elements (RAREs) near target genes. RA was first implicated in signalling on the basis of its teratogenic effects on limb development. Genetic studies later revealed that endogenous RA promotes forelimb initiation by repressing fibroblast growth factor 8 (Fgf8). Insights into RA function in the limb serve as a paradigm for understanding how RA regulates other developmental processes. In vivo studies have identified RAREs that control repression of Fgf8 during body axis extension or activation of homeobox (Hox) genes and other key regulators during neuronal differentiation and organogenesis.
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Affiliation(s)
- Thomas J Cunningham
- Development, Aging, and Regeneration Program, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Road, La Jolla, California 92037, USA
| | - Gregg Duester
- Development, Aging, and Regeneration Program, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Road, La Jolla, California 92037, USA
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Abstract
Blood vessels are critical to deliver oxygen and nutrients to all of the tissues and organs throughout the body. The blood vessels that vascularize the central nervous system (CNS) possess unique properties, termed the blood-brain barrier, which allow these vessels to tightly regulate the movement of ions, molecules, and cells between the blood and the brain. This precise control of CNS homeostasis allows for proper neuronal function and also protects the neural tissue from toxins and pathogens, and alterations of these barrier properties are an important component of pathology and progression of different neurological diseases. The physiological barrier is coordinated by a series of physical, transport, and metabolic properties possessed by the endothelial cells (ECs) that form the walls of the blood vessels, and these properties are regulated by interactions with different vascular, immune, and neural cells. Understanding how these different cell populations interact to regulate the barrier properties is essential for understanding how the brain functions during health and disease.
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Affiliation(s)
- Richard Daneman
- Departments of Neuroscience and Pharmacology, University of California, San Diego, San Diego, California 92093
| | - Alexandre Prat
- Department of Neuroscience, Université de Montréal, Montréal, Quebec H2X 0A9, Canada
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Okano J, Udagawa J, Shiota K. Roles of retinoic acid signaling in normal and abnormal development of the palate and tongue. Congenit Anom (Kyoto) 2014; 54:69-76. [PMID: 24666225 DOI: 10.1111/cga.12049] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 12/26/2013] [Indexed: 02/02/2023]
Abstract
Palatogenesis involves various developmental events such as growth, elevation, elongation and fusion of opposing palatal shelves. Extrinsic factors such as mouth opening and subsequent tongue withdrawal are also needed for the horizontal elevation of palate shelves. Failure of any of these steps can lead to cleft palate, one of the most common birth defects in humans. It has been shown that retinoic acid (RA) plays important roles during palate development, but excess RA causes cleft palate in fetuses of both rodents and humans. Thus, the coordinated regulation of retinoid metabolism is essential for normal palatogenesis. The endogenous RA level is determined by the balance of RA-synthesizing (retinaldehyde dehydrogenases: RALDHs) and RA-degrading enzymes (CYP26s). Cyp26b1 is a key player in normal palatogenesis. In this review, we discuss recent progress in the study of the pathogenesis of RA-induced cleft palate, with special reference to the regulation of endogenous RA levels by RA-degrading enzymes.
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Affiliation(s)
- Junko Okano
- Department of Anatomy and Cell Biology, Shiga University of Medical Science, Otsu
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31
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Taibi G, Gueli MC, Nicotra CMA, Cocciadiferro L, Carruba G. Retinol oxidation to retinoic acid in human thyroid glandular cells. J Enzyme Inhib Med Chem 2014; 29:796-803. [PMID: 24506204 DOI: 10.3109/14756366.2013.855928] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract Retinoic acid is regarded as the retinol metabolite that controls proliferation and differentiation of epithelial cells. In the present study, we investigated the potential role of xanthine dehydrogenase (XDH) in retinoic acid biosynthesis in human thyroid glandular cells (HTGC). In particular, we observed that cellular retinoids binding proteins (CRBPs) are also implicated in the biosynthetic pathway leading to retinoic acid formation in primary cultures of HTGC, as we have already reported for human mammary epithelial cells (HMEC). After partial protein purification, the enzyme responsible for retinoic acid biosynthesis was identified and quantified as XDH by immunoassay, by its ability to oxidize xanthine to uric acid and its sensitivity to the inhibitory effect of oxypurinol. The evidence of XDH-driven formation of retinoic acid in HTGC cultures further corroborates the potential role of XDH in retinoic acid biosynthesis in the epithelia.
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Affiliation(s)
- Gennaro Taibi
- Dipartimento di Biomedicina Sperimentale e Neuroscienze Cliniche, Università degli Studi di Palermo , Palermo , Italy
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Alfano C, Magrinelli E, Harb K, Studer M. The nuclear receptors COUP-TF: a long-lasting experience in forebrain assembly. Cell Mol Life Sci 2014; 71:43-62. [PMID: 23525662 PMCID: PMC11114017 DOI: 10.1007/s00018-013-1320-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2012] [Revised: 02/14/2013] [Accepted: 03/04/2013] [Indexed: 12/16/2022]
Abstract
Chicken ovalbumin upstream promoter transcription factors (COUP-TFs) are nuclear receptors belonging to the superfamily of the steroid/thyroid hormone receptors. Members of this family are internalized to the nucleus both in a ligand-dependent or -independent manner and act as strong transcriptional regulators by binding to the DNA of their target genes. COUP-TFs are defined as orphan receptors, since ligands regulating their activity have not so far been identified. From the very beginning of metazoan evolution, these molecules have been involved in various key events during embryonic development and organogenesis. In this review, we will mainly focus on their function during development and maturation of the central nervous system, which has been well characterized in various animal classes ranging from ctenophores to mammals. We will start by introducing the current knowledge on COUP-TF mechanisms of action and then focus our discussion on the crucial processes underlying forebrain ontogenesis, with special emphasis on mammalian development. Finally, the conserved roles of COUP-TFs along phylogenesis will be highlighted, and some hypotheses, worth exploring in future years to gain more insight into the mechanisms controlled by these factors, will be proposed.
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Affiliation(s)
- Christian Alfano
- Institute of Biology Valrose, iBV, UMR INSERM1091/CNRS7277/UNS, 06108 Nice, France
- University of Nice-Sophia Antipolis, UFR Sciences, 06108 Nice, France
| | - Elia Magrinelli
- Institute of Biology Valrose, iBV, UMR INSERM1091/CNRS7277/UNS, 06108 Nice, France
- University of Nice-Sophia Antipolis, UFR Sciences, 06108 Nice, France
| | - Kawssar Harb
- Institute of Biology Valrose, iBV, UMR INSERM1091/CNRS7277/UNS, 06108 Nice, France
- University of Nice-Sophia Antipolis, UFR Sciences, 06108 Nice, France
| | - Michèle Studer
- Institute of Biology Valrose, iBV, UMR INSERM1091/CNRS7277/UNS, 06108 Nice, France
- University of Nice-Sophia Antipolis, UFR Sciences, 06108 Nice, France
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Alvarez JI, Katayama T, Prat A. Glial influence on the blood brain barrier. Glia 2013; 61:1939-58. [PMID: 24123158 PMCID: PMC4068281 DOI: 10.1002/glia.22575] [Citation(s) in RCA: 380] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 08/13/2013] [Accepted: 08/19/2013] [Indexed: 12/14/2022]
Abstract
The Blood Brain Barrier (BBB) is a specialized vascular structure tightly regulating central nervous system (CNS) homeostasis. Endothelial cells are the central component of the BBB and control of their barrier phenotype resides on astrocytes and pericytes. Interactions between these cells and the endothelium promote and maintain many of the physiological and metabolic characteristics that are unique to the BBB. In this review we describe recent findings related to the involvement of astroglial cells, including radial glial cells, in the induction of barrier properties during embryogenesis and adulthood. In addition, we describe changes that occur in astrocytes and endothelial cells during injury and inflammation with a particular emphasis on alterations of the BBB phenotype. GLIA 2013;61:1939–1958
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Affiliation(s)
- Jorge Ivan Alvarez
- Neuroimmunology unit, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada
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Schulte D, Frank D. TALE transcription factors during early development of the vertebrate brain and eye. Dev Dyn 2013; 243:99-116. [DOI: 10.1002/dvdy.24030] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 07/11/2013] [Accepted: 07/13/2013] [Indexed: 12/25/2022] Open
Affiliation(s)
- Dorothea Schulte
- Institute of Neurology (Edinger Institute); University Hospital Frankfurt, J.W. Goethe University; Frankfurt Germany
| | - Dale Frank
- Department of Biochemistry; The Rappaport Family Institute for Research in the Medical Sciences, Faculty of Medicine, Technion-Israel Institute of Technology; Haifa Israel
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Franzosa JA, Bugel SM, Tal TL, La Du JK, Tilton SC, Waters KM, Tanguay RL. Retinoic acid-dependent regulation of miR-19 expression elicits vertebrate axis defects. FASEB J 2013; 27:4866-76. [PMID: 23975936 DOI: 10.1096/fj.12-225524] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Retinoic acid (RA) is involved in multifarious and complex functions necessary for vertebrate development. RA signaling is reliant on strict enzymatic regulation of RA synthesis and metabolism. Improper spatiotemporal expression of RA during development can result in vertebrate axis defects. microRNAs (miRNAs) are also pivotal in orchestrating developmental processes. While mechanistic links between miRNAs and axial development are established, the role of miRNAs in regulating metabolic enzymes responsible for RA abundance during axis formation has yet to be elucidated. Our results uncovered a role of miR-19 family members in controlling RA metabolism through the regulation of CYP26A1 during vertebrate axis formation. Global miRNA expression profiling showed that developmental RA exposure suppressed the expression of miR-19 family members during zebrafish somitogenesis. A reporter assay confirmed that cyp26a1 is a bona fide target of miR-19 in vivo. Transient knockdown of miR-19 phenocopied axis defects caused by RA exposure. Exogenous miR-19 rescued the axis defects induced by RA exposure. Taken together, these results indicate that the teratogenic effects of RA exposure result, in part, from repression of miR-19 expression and subsequent misregulation of cyp26a1. This highlights a previously unidentified role of miR-19 in facilitating vertebrate axis development via regulation of RA signaling.
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Affiliation(s)
- Jill A Franzosa
- 3Department of Environmental and Molecular Toxicology, Oregon State University, 28645 East HWY 34. Corvallis, OR 97333, USA.
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36
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Orsolits B, Borsy A, Madarász E, Mészáros Z, Kőhidi T, Markó K, Jelitai M, Welker E, Környei Z. Retinoid machinery in distinct neural stem cell populations with different retinoid responsiveness. Stem Cells Dev 2013; 22:2777-93. [PMID: 23734950 DOI: 10.1089/scd.2012.0422] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Retinoic acid (RA) is present at sites of neurogenesis in both the embryonic and adult brain. While it is widely accepted that RA signaling is involved in the regulation of neural stem cell differentiation, little is known about vitamin A utilization and biosynthesis of active retinoids in the neurogenic niches, or about the details of retinoid metabolism in neural stem cells and differentiating progenies. Here we provide data on retinoid responsiveness and RA production of distinct neural stem cell/neural progenitor populations. In addition, we demonstrate differentiation-related changes in the expression of genes encoding proteins of the retinoid machinery, including components responsible for uptake (Stra6) and storage (Lrat) of vitamin A, transport of retinoids (Rbp4, CrbpI, CrabpI-II), synthesis (Rdh10, Raldh1-4), degradation of RA (Cyp26a1-c1) and RA signaling (Rarα,β,γ, Rxrα,β,γ). We show that both early embryonic neuroectodermal (NE-4C) stem cells and late embryonic or adult derived radial glia like progenitors (RGl cells) are capable to produce bioactive retinoids but respond differently to retinoid signals. However, while neuronal differentiation of RGl cells can not be induced by RA, neuron formation by NE-4C cells is initiated by both RA and RA-precursors (retinol or retinyl acetate). The data indicate that endogenous RA production, at least in some neural stem cell populations, may result in autocrine regulation of neuronal differentiation.
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Affiliation(s)
- Barbara Orsolits
- 1 Institute of Experimental Medicine , Hungarian Academy of Sciences, Budapest, Hungary
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37
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Yahyavi M, Abouzeid H, Gawdat G, de Preux AS, Xiao T, Bardakjian T, Schneider A, Choi A, Jorgenson E, Baier H, El Sada M, Schorderet DF, Slavotinek AM. ALDH1A3 loss of function causes bilateral anophthalmia/microphthalmia and hypoplasia of the optic nerve and optic chiasm. Hum Mol Genet 2013; 22:3250-8. [PMID: 23591992 DOI: 10.1093/hmg/ddt179] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The major active retinoid, all-trans retinoic acid, has long been recognized as critical for the development of several organs, including the eye. Mutations in STRA6, the gene encoding the cellular receptor for vitamin A, in patients with Matthew-Wood syndrome and anophthalmia/microphthalmia (A/M), have previously demonstrated the importance of retinol metabolism in human eye disease. We used homozygosity mapping combined with next-generation sequencing to interrogate patients with anophthalmia and microphthalmia for new causative genes. We used whole-exome and whole-genome sequencing to study a family with two affected brothers with bilateral A/M and a simplex case with bilateral anophthalmia and hypoplasia of the optic nerve and optic chiasm. Analysis of novel sequence variants revealed homozygosity for two nonsense mutations in ALDH1A3, c.568A>G, predicting p.Lys190*, in the familial cases, and c.1165A>T, predicting p.Lys389*, in the simplex case. Both mutations predict nonsense-mediated decay and complete loss of function. We performed antisense morpholino (MO) studies in Danio rerio to characterize the developmental effects of loss of Aldh1a3 function. MO-injected larvae showed a significant reduction in eye size, and aberrant axonal projections to the tectum were noted. We conclude that ALDH1A3 loss of function causes anophthalmia and aberrant eye development in humans and in animal model systems.
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Affiliation(s)
- Mani Yahyavi
- Division of Genetics, Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143-0748, USA
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38
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Abstract
The blood-brain barrier (BBB) is crucial in the maintenance of a controlled environment within the brain to safeguard optimal neuronal function. The endothelial cells (ECs) of the BBB possess specific properties that restrict the entry of cells and metabolites into the CNS. The specialized BBB endothelial phenotype is induced during neurovascular development by surrounding cells of the CNS. However, the molecular differentiation of the BBB endothelium remains poorly understood. Retinoic acid (RA) plays a crucial role in the brain during embryogenesis. Because radial glial cells supply the brain with RA during the developmental cascade and associate closely with the developing vasculature, we hypothesize that RA is important for the induction of BBB properties in brain ECs. Analysis of human postmortem fetal brain tissue shows that the enzyme mainly responsible for RA synthesis, retinaldehyde dehydrogenase, is expressed by radial glial cells. In addition, the most important receptor for RA-driven signaling in the CNS, RA-receptor β (RARβ), is markedly expressed by the developing brain vasculature. Our findings have been further corroborated by in vitro experiments showing RA- and RARβ-dependent induction of different aspects of the brain EC barrier. Finally, pharmacologic inhibition of RAR activation during the differentiation of the murine BBB resulted in the leakage of a fluorescent tracer as well as serum proteins into the developing brain and reduced the expression levels of important BBB determinants. Together, our results point to an important role for RA in the induction of the BBB during human and mouse development.
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39
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Spencer PS, Palmer VS. Interrelationships of undernutrition and neurotoxicity: food for thought and research attention. Neurotoxicology 2012; 33:605-16. [PMID: 22394483 PMCID: PMC3437940 DOI: 10.1016/j.neuro.2012.02.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 02/13/2012] [Accepted: 02/13/2012] [Indexed: 12/25/2022]
Abstract
The neurotoxic actions of chemical agents on humans and animals are usually studied with little consideration of the subject's nutritional status. States of protein-calorie, vitamin and/or mineral undernutrition are associated with a range of neurodevelopmental, neurological and psychiatric disorders, commonly with involvement of both the central and the peripheral nervous system. Undernutrition can modify risk for certain chemical-induced neurologic diseases, and in some cases undernutrition may be a prerequisite for neurotoxicity to surface. In addition, neurologic disease associated with undernutrition or neurotoxicity may show similarities in clinical and neuropathological expression, especially in the peripheral nervous system. The combined effects of undernutrition and chemical neurotoxicity are most relevant to people with low incomes who experience chronic hunger, parasitism and infectious disease, monotonous diets of plants with neurotoxic potential (notably cassava), environmental pollution from rapid industrial development, chronic alcohol abuse, or prolonged treatment with certain therapeutic drugs. Undernutrition alone or in combination with chemical exposure is also important in high-income societies in the setting of drug and alcohol abuse, old age, food faddism, post-bariatric surgery, and drug treatment for certain medical conditions, including cancer and tuberculosis. The nutritional demands of pregnancy and lactation increase the risk of fetal and infant undernutrition and chemical interactions therewith.
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Affiliation(s)
- Peter S Spencer
- Global Health Center, Center for Research on Occupational and Environmental Toxicology, and Department of Neurology, School of Medicine, Oregon Health & Science University, Portland, OR 97239, United States.
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40
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Kennedy AE, Dickinson AJG. Median facial clefts in Xenopus laevis: roles of retinoic acid signaling and homeobox genes. Dev Biol 2012; 365:229-40. [PMID: 22405964 DOI: 10.1016/j.ydbio.2012.02.033] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 02/22/2012] [Accepted: 02/24/2012] [Indexed: 12/28/2022]
Abstract
The upper lip and primary palate form an essential separation between the brain, nasal structures and the oral cavity. Surprisingly little is known about the development of these structures, despite the fact that abnormalities can result in various forms of orofacial clefts. We have uncovered that retinoic acid is a critical regulator of upper lip and primary palate development in Xenopus laevis. Retinoic acid synthesis enzyme, RALDH2, and retinoic acid receptor gamma (RARγ) are expressed in complementary and partially overlapping regions of the orofacial prominences that fate mapping revealed contribute to the upper lip and primary palate. Decreased RALDH2 and RARγ result in a median cleft in the upper lip and primary palate. To further understand how retinoic acid regulates upper lip and palate morphogenesis we searched for genes downregulated in response to RARγ inhibition in orofacial tissue, and uncovered homeobox genes lhx8 and msx2. These genes are both expressed in overlapping domains with RARγ, and together their loss of function also results in a median cleft in the upper lip and primary palate. Inhibition of RARγ and decreased Lhx8/Msx2 function result in decreased cell proliferation and failure of dorsal anterior cartilages to form. These results suggest a model whereby retinoic acid signaling regulates Lhx8 and Msx2, which together direct the tissue growth and differentiation necessary for the upper lip and primary palate morphogenesis. This work has the potential to better understand the complex nature of the upper lip and primary palate development which will lead to important insights into the etiology of human orofacial clefts.
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Affiliation(s)
- Allyson E Kennedy
- Virginia Commonwealth University, 1000 West Cary St., Department of Biology, Richmond, VA 23284, USA
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41
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Kam RKT, Deng Y, Chen Y, Zhao H. Retinoic acid synthesis and functions in early embryonic development. Cell Biosci 2012; 2:11. [PMID: 22439772 PMCID: PMC3325842 DOI: 10.1186/2045-3701-2-11] [Citation(s) in RCA: 167] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 03/22/2012] [Indexed: 01/08/2023] Open
Abstract
Retinoic acid (RA) is a morphogen derived from retinol (vitamin A) that plays important roles in cell growth, differentiation, and organogenesis. The production of RA from retinol requires two consecutive enzymatic reactions catalyzed by different sets of dehydrogenases. The retinol is first oxidized into retinal, which is then oxidized into RA. The RA interacts with retinoic acid receptor (RAR) and retinoic acid X receptor (RXR) which then regulate the target gene expression. In this review, we have discussed the metabolism of RA and the important components of RA signaling pathway, and highlighted current understanding of the functions of RA during early embryonic development.
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Affiliation(s)
- Richard Kin Ting Kam
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, P, R, China.
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42
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Viegas P, Nicoleau C, Perrier AL. Derivation of striatal neurons from human stem cells. PROGRESS IN BRAIN RESEARCH 2012. [DOI: 10.1016/b978-0-444-59575-1.00017-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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43
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Liu L, Suzuki K, Nakagata N, Mihara K, Matsumaru D, Ogino Y, Yashiro K, Hamada H, Liu Z, Evans SM, Mendelsohn C, Yamada G. Retinoic acid signaling regulates sonic hedgehog and bone morphogenetic protein signalings during genital tubercle development. ACTA ACUST UNITED AC 2011; 95:79-88. [PMID: 22127979 DOI: 10.1002/bdrb.20344] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 10/04/2011] [Indexed: 01/07/2023]
Abstract
Retinoic acid (RA) plays pivotal roles in organogenesis, and both excessive and reduced amounts of RA cause developmental abnormalities. Reproductive organs are susceptible to teratogen toxigenicity, and the genital tubercle (GT) is one such representative organ. The physiological function of endogenous RA signaling and the mechanisms of RA-induced teratogenicity are poorly understood during the GT development. The objective of this study is to understand the developmental and teratogenic roles of RA during GT development by analyzing genetically modified mouse models. We found dynamic patterns of gene expression for the RA-synthesizing enzyme, Raldh2, and for the RA-catabolizing enzyme, Cyp26b1, during GT development. Rarb, an indicator gene for RA signaling, starts its expression in the prospective corpus cavernosum penis and in the urethral plate epithelium (UE), which plays central roles during GT development. Excessive RA signaling in Cyp26b1(-/-) mutants leads to abnormal extents of cell proliferation and differentiation during GT development, and also upregulates expression of growth factor signalings. They include Sonic hedgehog (Shh) signaling and Bone morphogenetic protein (Bmp) signaling, which are expressed in the UE and its bilateral mesenchyme. RA signaling positively regulatesShh and Bmp4 expression during GT development as testified also by the experiment of RA administration and analyses of loss-of-function of RA signaling mutants. Thus, RA signaling is involved in the developmental cascade necessary for UE formation and GT development.
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Affiliation(s)
- Liqing Liu
- Department of Organ Formation, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
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Abstract
In canonical Wnt signaling, β-catenin translocates to the cell nucleus, interacting with Tcf/Lef factors to activate transcription of Wnt target genes. In this issue of Genes & Development, Vacik and colleagues (pp. 1783-1795) report that a highly conserved sequence in intron 5 of Tcf7l2 conceals an internal promoter region that, when activated by Vax2, drives transcription of truncated Tcf7l2 mRNAs. The encoded Tcf7l2 protein binds to DNA, but not β-catenin, and therefore acts as a dominant-negative Wnt antagonist.
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Affiliation(s)
- Elizabeth A Grove
- Department of Neurobiology, University of Chicago, Chicago, Illinois 60637, USA.
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45
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Involvement of retinol dehydrogenase 10 in embryonic patterning and rescue of its loss of function by maternal retinaldehyde treatment. Proc Natl Acad Sci U S A 2011; 108:16687-92. [PMID: 21930923 DOI: 10.1073/pnas.1103877108] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Retinoic acid (RA), an active vitamin A metabolite, is a key signaling molecule in vertebrate embryos. Morphogenetic RA gradients are thought to be set up by tissue-specific actions of retinaldehyde dehydrogenases (RALDHs) and catabolizing enzymes. According to the species, two enzymatic pathways (β-carotene cleavage and retinol oxidation) generate retinaldehyde, the substrate of RALDHs. Placental species depend on maternal retinol transferred to the embryo. The retinol-to-retinaldehyde conversion was thought to be achieved by several redundant enzymes; however, a random mutagenesis screen identified retinol dehydrogenase 10 [Rdh10(Trex) allele; Sandell LL, et al. (2007) Genes Dev 21:1113-1124] as responsible for a homozygous lethal phenotype with features of RA deficiency. We report here the production and characterization of unique murine Rdh10 loss-of-function alleles generated by gene targeting. We show that although Rdh10(-/-) mutants die at an earlier stage than Rdh10(Trex) mutants, their molecular patterning defects do not reflect a complete state of RA deficiency. Furthermore, we were able to correct most developmental abnormalities by administering retinaldehyde to pregnant mothers, thereby obtaining viable Rdh10(-/-) mutants. This demonstrates the rescue of an embryonic lethal phenotype by simple maternal administration of the missing retinoid compound. These results underscore the importance of maternal retinoids in preventing congenital birth defects, and lead to a revised model of the importance of RDH10 and RALDHs in controlling embryonic RA distribution.
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Goulburn AL, Alden D, Davis RP, Micallef SJ, Ng ES, Yu QC, Lim SM, Soh CL, Elliott DA, Hatzistavrou T, Bourke J, Watmuff B, Lang RJ, Haynes JM, Pouton CW, Giudice A, Trounson AO, Anderson SA, Stanley EG, Elefanty AG. A targeted NKX2.1 human embryonic stem cell reporter line enables identification of human basal forebrain derivatives. Stem Cells 2011; 29:462-73. [PMID: 21425409 DOI: 10.1002/stem.587] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have used homologous recombination in human embryonic stem cells (hESCs) to insert sequences encoding green fluorescent protein (GFP) into the NKX2.1 locus, a gene required for normal development of the basal forebrain. Generation of NKX2.1-GFP(+) cells was dependent on the concentration, timing, and duration of retinoic acid treatment during differentiation. NKX2.1-GFP(+) progenitors expressed genes characteristic of the basal forebrain, including SHH, DLX1, LHX6, and OLIG2. Time course analysis revealed that NKX2.1-GFP(+) cells could upregulate FOXG1 expression, implying the existence of a novel pathway for the generation of telencephalic neural derivatives. Further maturation of NKX2.1-GFP(+) cells gave rise to γ-aminobutyric acid-, tyrosine hydroxylase-, and somatostatin-expressing neurons as well as to platelet-derived growth factor receptor α-positive oligodendrocyte precursors. These studies highlight the diversity of cell types that can be generated from human NKX2.1(+) progenitors and demonstrate the utility of NKX2.1(GFP/w) hESCs for investigating human forebrain development and neuronal differentiation.
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Affiliation(s)
- Adam L Goulburn
- Monash Immunology and Stem Cell Laboratories, Monash University, Clayton, Victoria, Australia
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47
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Clagett-Dame M, Knutson D. Vitamin A in reproduction and development. Nutrients 2011; 3:385-428. [PMID: 22254103 PMCID: PMC3257687 DOI: 10.3390/nu3040385] [Citation(s) in RCA: 235] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 02/28/2011] [Accepted: 03/22/2011] [Indexed: 12/12/2022] Open
Abstract
The requirement for vitamin A in reproduction was first recognized in the early 1900's, and its importance in the eyes of developing embryos was realized shortly after. A greater understanding of the large number of developmental processes that require vitamin A emerged first from nutritional deficiency studies in rat embryos, and later from genetic studies in mice. It is now generally believed that all-trans retinoic acid (RA) is the form of vitamin A that supports both male and female reproduction as well as embryonic development. This conclusion is based on the ability to reverse most reproductive and developmental blocks found in vitamin A deficiency induced either by nutritional or genetic means with RA, and the ability to recapitulate the majority of embryonic defects in retinoic acid receptor compound null mutants. The activity of the catabolic CYP26 enzymes in determining what tissues have access to RA has emerged as a key regulatory mechanism, and helps to explain why exogenous RA can rescue many vitamin A deficiency defects. In severely vitamin A-deficient (VAD) female rats, reproduction fails prior to implantation, whereas in VAD pregnant rats given small amounts of carotene or supported on limiting quantities of RA early in organogenesis, embryos form but show a collection of defects called the vitamin A deficiency syndrome or late vitamin A deficiency. Vitamin A is also essential for the maintenance of the male genital tract and spermatogenesis. Recent studies show that vitamin A participates in a signaling mechanism to initiate meiosis in the female gonad during embryogenesis, and in the male gonad postnatally. Both nutritional and genetic approaches are being used to elucidate the vitamin A-dependent pathways upon which these processes depend.
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Affiliation(s)
- Margaret Clagett-Dame
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA;
- School of Pharmacy, Pharmaceutical Sciences Division, University of Wisconsin-Madison, 777 Highland Ave., Madison, WI 53705, USA
| | - Danielle Knutson
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA;
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Dollé P, Fraulob V, Gallego-Llamas J, Vermot J, Niederreither K. Fate of retinoic acid-activated embryonic cell lineages. Dev Dyn 2011; 239:3260-74. [PMID: 21046629 DOI: 10.1002/dvdy.22479] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Retinoic acid (RA), a vitamin A derivative, is synthesized by specific cell populations and acts as a diffusible embryonic signal activating ligand-inducible transcription factors, the RA receptors (RARs). RA-activatable transgenic systems have revealed many discrete, transient sites of RA action during development. However, there has been no attempt to permanently label the RA-activated cell lineages during mouse ontogenesis. We describe the characterization of a RA-activatable Cre transgene, which through crosses with a conditional reporter strain (the ROSA26R lacZ reporter), leads to a stable labeling of the cell populations experiencing RA signaling during embryogenesis. RA response-element (RARE)-driven Cre activity mimics at early stages the known activity of the corresponding RARE-lacZ transgene (Rossant et al.,1991). Stable labeling of the Cre-excised cell populations allows to trace the distribution of the RA-activated cell lineages at later stages. These are described in relationship with current models of RA activity in various developmental systems, including the embryonic caudal region, limb buds, hindbrain, sensory organs, and heart.
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Affiliation(s)
- Pascal Dollé
- IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Illkirch, France.
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49
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Wang C, Kane MA, Napoli JL. Multiple retinol and retinal dehydrogenases catalyze all-trans-retinoic acid biosynthesis in astrocytes. J Biol Chem 2010; 286:6542-53. [PMID: 21138835 DOI: 10.1074/jbc.m110.198382] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
All-trans-retinoic acid (atRA) stimulates neurogenesis, dendritic growth of hippocampal neurons, and higher cognitive functions, such as spatial learning and memory formation. Although astrocyte-derived atRA has been considered a key factor in neurogenesis, little direct evidence identifies hippocampus cell types and the enzymes that biosynthesize atRA. Here we show that primary rat astrocytes, but not neurons, biosynthesize atRA using multiple retinol dehydrogenases (Rdh) of the short chain dehydrogenase/reductase gene family and retinaldehyde dehydrogenases (Raldh). Astrocytes secrete atRA into their medium; neurons sequester atRA. The first step, conversion of retinol into retinal, is rate-limiting. Neurons and astrocytes both synthesize retinyl esters and reduce retinal into retinol. siRNA knockdown indicates that Rdh10, Rdh2 (mRdh1), and Raldh1, -2, and -3 contribute to atRA production. Knockdown of the Rdh Dhrs9 increased atRA synthesis ∼40% by increasing Raldh1 expression. Immunocytochemistry revealed cytosolic and nuclear expression of Raldh1 and cytosol and perinuclear expression of Raldh2. atRA autoregulated its concentrations by inducing retinyl ester synthesis via lecithin:retinol acyltransferase and stimulating its catabolism via inducing Cyp26B1. These data show that adult hippocampus astrocytes rely on multiple Rdh and Raldh to provide a paracrine source of atRA to neurons, and atRA regulates its own biosynthesis in astrocytes by directing flux of retinol. Observation of cross-talk between Dhrs9 and Raldh1 provides a novel mechanism of regulating atRA biosynthesis.
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Affiliation(s)
- Chao Wang
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California 94720, USA
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Minoux M, Rijli FM. Molecular mechanisms of cranial neural crest cell migration and patterning in craniofacial development. Development 2010; 137:2605-21. [DOI: 10.1242/dev.040048] [Citation(s) in RCA: 329] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
During vertebrate craniofacial development, neural crest cells (NCCs) contribute much of the cartilage, bone and connective tissue that make up the developing head. Although the initial patterns of NCC segmentation and migration are conserved between species, the variety of vertebrate facial morphologies that exist indicates that a complex interplay occurs between intrinsic genetic NCC programs and extrinsic environmental signals during morphogenesis. Here, we review recent work that has begun to shed light on the molecular mechanisms that govern the spatiotemporal patterning of NCC-derived skeletal structures – advances that are central to understanding craniofacial development and its evolution.
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Affiliation(s)
- Maryline Minoux
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- Faculté de Chirurgie Dentaire, 1, Place de l'Hôpital, 67000 Strasbourg, France
| | - Filippo M. Rijli
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
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