1
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Murakami S, Ohki-Hamazaki H, Uchiyama Y. Somatostatin affects GnRH neuronal development and migration and stimulates olfactory-related fiber fasciculation. Dev Neurobiol 2024; 84:3-17. [PMID: 38072668 DOI: 10.1002/dneu.22931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 11/10/2023] [Accepted: 11/23/2023] [Indexed: 01/19/2024]
Abstract
Transient expression of somatostatin (SST) has been observed in the olfactory epithelium (OE) and nerves of chick embryos. Intense expression of SST in these regions on embryonic days (E) 5-8 coincides with the migration of neurons producing gonadotropin-releasing hormone (GnRH) from the OE to the forebrain (FB), suggesting that SST plays a role in the development of GnRH neurons. Using in ovo electroporation of small interfering RNA, we found that the suppression of SST mRNA in the olfactory placode (OP) of E3.5 chick embryos significantly reduced the number of GnRH and Islet-1-immunoreactive neurons in the nasal region without affecting the entry of GnRH neurons into the FB at E5.5-6. SST knockdown did not lead to changes in the number of apoptotic, proliferating, or HuC/D-positive neuronal cells in the OE; therefore, it is possible that SST is involved in the neurogenesis/differentiation of GnRH neurons and OP-derived GnRH-negative migratory neurons. In whole OP explant cultures, we also found that SST or its analog octreotide treatment significantly increased the number of migratory GnRH neurons and the migratory distance from the explants. The co-application of an SST antagonist blocked the octreotide-induced increase in the number of GnRH neurons. Furthermore, the fasciculation of polysialylated neural cell adhesion molecule-immunoreactive fibers emerging from the explants was dependent on octreotide. Taken together, our results provide evidence that SST exerts facilitatory effects on the development of neurons expressing GnRH or Islet-1 and on GnRH neuronal migration, in addition to olfactory-related fiber fasciculation.
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Affiliation(s)
- Shizuko Murakami
- Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Hiroko Ohki-Hamazaki
- College of Liberal Arts and Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Yasuo Uchiyama
- Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, Tokyo, Japan
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2
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Bedogni F, Hevner RF. Cell-Type-Specific Gene Expression in Developing Mouse Neocortex: Intermediate Progenitors Implicated in Axon Development. Front Mol Neurosci 2021; 14:686034. [PMID: 34321999 PMCID: PMC8313239 DOI: 10.3389/fnmol.2021.686034] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 06/03/2021] [Indexed: 01/06/2023] Open
Abstract
Cerebral cortex projection neurons (PNs) are generated from intermediate progenitors (IPs), which are in turn derived from radial glial progenitors (RGPs). To investigate developmental processes in IPs, we profiled IP transcriptomes in embryonic mouse neocortex, using transgenic Tbr2-GFP mice, cell sorting, and microarrays. These data were used in combination with in situ hybridization to ascertain gene sets specific for IPs, RGPs, PNs, interneurons, and other neural and non-neural cell types. RGP-selective transcripts (n = 419) included molecules for Notch receptor signaling, proliferation, neural stem cell identity, apical junctions, necroptosis, hippo pathway, and NF-κB pathway. RGPs also expressed specific genes for critical interactions with meningeal and vascular cells. In contrast, IP-selective genes (n = 136) encoded molecules for activated Delta ligand presentation, epithelial-mesenchymal transition, core planar cell polarity (PCP), axon genesis, and intrinsic excitability. Interestingly, IPs expressed several “dependence receptors” (Unc5d, Dcc, Ntrk3, and Epha4) that induce apoptosis in the absence of ligand, suggesting a competitive mechanism for IPs and new PNs to detect key environmental cues or die. Overall, our results imply a novel role for IPs in the patterning of neuronal polarization, axon differentiation, and intrinsic excitability prior to mitosis. Significantly, IPs highly express Wnt-PCP, netrin, and semaphorin pathway molecules known to regulate axon polarization in other systems. In sum, IPs not only amplify neurogenesis quantitatively, but also molecularly “prime” new PNs for axogenesis, guidance, and excitability.
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Affiliation(s)
| | - Robert F Hevner
- Department of Pathology, University of California, San Diego, La Jolla, CA, United States
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3
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Patthy Á, Murai J, Hanics J, Pintér A, Zahola P, Hökfelt TGM, Harkany T, Alpár A. Neuropathology of the Brainstem to Mechanistically Understand and to Treat Alzheimer's Disease. J Clin Med 2021; 10:jcm10081555. [PMID: 33917176 PMCID: PMC8067882 DOI: 10.3390/jcm10081555] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/01/2021] [Accepted: 04/05/2021] [Indexed: 12/18/2022] Open
Abstract
Alzheimer’s disease (AD) is a devastating neurodegenerative disorder as yet without effective therapy. Symptoms of this disorder typically reflect cortical malfunction with local neurohistopathology, which biased investigators to search for focal triggers and molecular mechanisms. Cortex, however, receives massive afferents from caudal brain structures, which do not only convey specific information but powerfully tune ensemble activity. Moreover, there is evidence that the start of AD is subcortical. The brainstem harbors monoamine systems, which establish a dense innervation in both allo- and neocortex. Monoaminergic synapses can co-release neuropeptides either by precisely terminating on cortical neurons or, when being “en passant”, can instigate local volume transmission. Especially due to its early damage, malfunction of the ascending monoaminergic system emerges as an early sign and possible trigger of AD. This review summarizes the involvement and cascaded impairment of brainstem monoaminergic neurons in AD and discusses cellular mechanisms that lead to their dysfunction. We highlight the significance and therapeutic challenges of transmitter co-release in ascending activating system, describe the role and changes of local connections and distant afferents of brainstem nuclei in AD, and summon the rapidly increasing diagnostic window during the last few years.
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Affiliation(s)
- Ágoston Patthy
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - János Murai
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - János Hanics
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
- SE NAP Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences, H-1094 Budapest, Hungary
| | - Anna Pintér
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - Péter Zahola
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
| | - Tomas G. M. Hökfelt
- Department of Neuroscience, Biomedicum 7D, Karolinska Institutet, 17165 Stockholm, Sweden; (T.G.M.H.); (T.H.)
| | - Tibor Harkany
- Department of Neuroscience, Biomedicum 7D, Karolinska Institutet, 17165 Stockholm, Sweden; (T.G.M.H.); (T.H.)
- Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, 1090 Vienna, Austria
| | - Alán Alpár
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary; (Á.P.); (J.M.); (J.H.); (A.P.); (P.Z.)
- SE NAP Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences, H-1094 Budapest, Hungary
- Correspondence:
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4
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Csaba Z, Vitalis T, Charriaut-Marlangue C, Margaill I, Coqueran B, Leger PL, Parente I, Jacquens A, Titomanlio L, Constans C, Demene C, Santin MD, Lehericy S, Perrière N, Glacial F, Auvin S, Tanter M, Ghersi-Egea JF, Adle-Biassette H, Aubry JF, Gressens P, Dournaud P. A simple novel approach for detecting blood-brain barrier permeability using GPCR internalization. Neuropathol Appl Neurobiol 2020; 47:297-315. [PMID: 32898926 PMCID: PMC7891648 DOI: 10.1111/nan.12665] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 07/30/2020] [Accepted: 08/22/2020] [Indexed: 01/01/2023]
Abstract
Aims Impairment of blood–brain barrier (BBB) is involved in numerous neurological diseases from developmental to aging stages. Reliable imaging of increased BBB permeability is therefore crucial for basic research and preclinical studies. Today, the analysis of extravasation of exogenous dyes is the principal method to study BBB leakage. However, these procedures are challenging to apply in pups and embryos and may appear difficult to interpret. Here we introduce a novel approach based on agonist‐induced internalization of a neuronal G protein‐coupled receptor widely distributed in the mammalian brain, the somatostatin receptor type 2 (SST2). Methods The clinically approved SST2 agonist octreotide (1 kDa), when injected intraperitoneally does not cross an intact BBB. At sites of BBB permeability, however, OCT extravasates and induces SST2 internalization from the neuronal membrane into perinuclear compartments. This allows an unambiguous localization of increased BBB permeability by classical immunohistochemical procedures using specific antibodies against the receptor. Results We first validated our approach in sensory circumventricular organs which display permissive vascular permeability. Through SST2 internalization, we next monitored BBB opening induced by magnetic resonance imaging‐guided focused ultrasound in murine cerebral cortex. Finally, we proved that after intraperitoneal agonist injection in pregnant mice, SST2 receptor internalization permits analysis of BBB integrity in embryos during brain development. Conclusions This approach provides an alternative and simple manner to assess BBB dysfunction and development in different physiological and pathological conditions.
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Affiliation(s)
- Z Csaba
- NeuroDiderot, Inserm U1141, Université de Paris, Paris, France
| | - T Vitalis
- NeuroDiderot, Inserm U1141, Université de Paris, Paris, France
| | | | - I Margaill
- Research Team "Pharmacology of Cerebral Circulation" EA4475, Faculté de Pharmacie de Paris, Université de Paris, Paris, France
| | - B Coqueran
- Research Team "Pharmacology of Cerebral Circulation" EA4475, Faculté de Pharmacie de Paris, Université de Paris, Paris, France
| | - P-L Leger
- NeuroDiderot, Inserm U1141, Université de Paris, Paris, France
| | - I Parente
- NeuroDiderot, Inserm U1141, Université de Paris, Paris, France
| | - A Jacquens
- NeuroDiderot, Inserm U1141, Université de Paris, Paris, France
| | - L Titomanlio
- NeuroDiderot, Inserm U1141, Université de Paris, Paris, France
| | - C Constans
- Institut Langevin, ESPCI Paris, PSL Research University, CNRS UMR7587, Inserm U979, Inserm Technology Research Accelerator in Biomedical Ultrasound, Université de Paris, Paris, France
| | - C Demene
- Institut Langevin, ESPCI Paris, PSL Research University, CNRS UMR7587, Inserm U979, Inserm Technology Research Accelerator in Biomedical Ultrasound, Université de Paris, Paris, France
| | - M D Santin
- Brain and Spine Institute-ICM, Center for NeuroImaging Research - CENIR, Sorbonne Paris Cité, UPMC Université Paris 06, Inserm U1127, CNRS UMR 7225, Paris, France
| | - S Lehericy
- Brain and Spine Institute-ICM, Center for NeuroImaging Research - CENIR, Sorbonne Paris Cité, UPMC Université Paris 06, Inserm U1127, CNRS UMR 7225, Paris, France
| | - N Perrière
- BrainPlotting, Brain and Spine Institute-ICM, Paris, France
| | - F Glacial
- BrainPlotting, Brain and Spine Institute-ICM, Paris, France
| | - S Auvin
- NeuroDiderot, Inserm U1141, Université de Paris, Paris, France
| | - M Tanter
- Institut Langevin, ESPCI Paris, PSL Research University, CNRS UMR7587, Inserm U979, Inserm Technology Research Accelerator in Biomedical Ultrasound, Université de Paris, Paris, France
| | - J-F Ghersi-Egea
- Fluid Team, Lyon Neurosciences Research Center, Inserm U1028, CNRS, UMR5292, University Lyon-1, Villeurbanne, France
| | - H Adle-Biassette
- NeuroDiderot, Inserm U1141, Université de Paris, Paris, France.,Service d'Anatomie et de Cytologie Pathologiques, Hôpital Lariboisière, APHP, Paris, France
| | - J-F Aubry
- Institut Langevin, ESPCI Paris, PSL Research University, CNRS UMR7587, Inserm U979, Inserm Technology Research Accelerator in Biomedical Ultrasound, Université de Paris, Paris, France
| | - P Gressens
- NeuroDiderot, Inserm U1141, Université de Paris, Paris, France
| | - P Dournaud
- NeuroDiderot, Inserm U1141, Université de Paris, Paris, France
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5
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Rahman T, Weickert CS, Harms L, Meehan C, Schall U, Todd J, Hodgson DM, Michie PT, Purves-Tyson T. Effect of Immune Activation during Early Gestation or Late Gestation on Inhibitory Markers in Adult Male Rats. Sci Rep 2020; 10:1982. [PMID: 32029751 PMCID: PMC7004984 DOI: 10.1038/s41598-020-58449-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 12/26/2019] [Indexed: 02/06/2023] Open
Abstract
People with schizophrenia exhibit deficits in inhibitory neurons and cognition. The timing of maternal immune activation (MIA) may present distinct schizophrenia-like phenotypes in progeny. We investigated whether early gestation [gestational day (GD) 10] or late gestation (GD19) MIA, via viral mimetic polyI:C, produces deficits in inhibitory neuron indices (GAD1, PVALB, SST, SSTR2 mRNAs) within cortical, striatal, and hippocampal subregions of male adult rat offspring. In situ hybridisation revealed that polyI:C offspring had: (1) SST mRNA reductions in the cingulate cortex and nucleus accumbens shell, regardless of MIA timing; (2) SSTR2 mRNA reductions in the cortex and striatum of GD19, but not GD10, MIA; (3) no alterations in cortical or striatal GAD1 mRNA of polyI:C offspring, but an expected reduction of PVALB mRNA in the infralimbic cortex, and; (4) no alterations in inhibitory markers in hippocampus. Maternal IL-6 response negatively correlated with adult offspring SST mRNA in cortex and striatum, but not hippocampus. These results show lasting inhibitory-related deficits in cortex and striatum in adult offspring from MIA. SST downregulation in specific cortical and striatal subregions, with additional deficits in somatostatin-related signalling through SSTR2, may contribute to some of the adult behavioural changes resulting from MIA and its timing.
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Affiliation(s)
- Tasnim Rahman
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.,Neuroscience Research Australia, Sydney, NSW, Australia
| | - Cynthia Shannon Weickert
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.,Neuroscience Research Australia, Sydney, NSW, Australia.,Department of Neuroscience and Physiology, Upstate Medical University, Syracuse, NY, USA
| | - Lauren Harms
- School of Psychology, The University of Newcastle, Sydney, NSW, Australia.,Priority Centre for Brain and Mental Health Research, The University of Newcastle, Newcastle, NSW, Australia.,Hunter Medical Research Institute, Newcastle, NSW, Australia
| | - Crystal Meehan
- School of Psychology, The University of Newcastle, Sydney, NSW, Australia.,Priority Centre for Brain and Mental Health Research, The University of Newcastle, Newcastle, NSW, Australia.,Hunter Medical Research Institute, Newcastle, NSW, Australia.,Division of Psychology, School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Ulrich Schall
- Priority Centre for Brain and Mental Health Research, The University of Newcastle, Newcastle, NSW, Australia.,Hunter Medical Research Institute, Newcastle, NSW, Australia.,School of Medicine and Public Health, The University of Newcastle, Newcastle, NSW, Australia
| | - Juanita Todd
- School of Psychology, The University of Newcastle, Sydney, NSW, Australia.,Priority Centre for Brain and Mental Health Research, The University of Newcastle, Newcastle, NSW, Australia.,Hunter Medical Research Institute, Newcastle, NSW, Australia
| | - Deborah M Hodgson
- School of Psychology, The University of Newcastle, Sydney, NSW, Australia.,Priority Centre for Brain and Mental Health Research, The University of Newcastle, Newcastle, NSW, Australia.,Hunter Medical Research Institute, Newcastle, NSW, Australia
| | - Patricia T Michie
- School of Psychology, The University of Newcastle, Sydney, NSW, Australia.,Priority Centre for Brain and Mental Health Research, The University of Newcastle, Newcastle, NSW, Australia.,Hunter Medical Research Institute, Newcastle, NSW, Australia
| | - Tertia Purves-Tyson
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia. .,Neuroscience Research Australia, Sydney, NSW, Australia.
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6
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Wang M, Xu P, Zhu Z. Regulation of signal transduction in Coilia nasus during migration. Genomics 2019; 112:55-64. [PMID: 31404627 DOI: 10.1016/j.ygeno.2019.07.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 07/31/2019] [Accepted: 07/31/2019] [Indexed: 12/11/2022]
Abstract
Coilia nasus (C. nasus) is an important anadromous fish species that resides in the Yangtze River in China. However, wild C. nasus have suffered serious damage as a result of overfishing and environmental pollution. We performed comparative liver and brain transcriptome analyses of C. nasus from the Jingjiang (JJ) and Dangtu (DT) sections of the Yangtze River. The results indicate that, during migration, most signal pathways in C. nasus livers were downregulated, indicating that the liver has a function in energy conservation. The brain assumes more of a regulatory role, and the signal transduction pathways and relevant genes were upregulated. This study provides genetic information for screening the key regulatory genes of gonad development of C. nasus, which can be applied in the artificial breeding of C. nasus, providing high-quality fish fry for proliferation and release and may also contribute to efforts towards the restoration of wild C. nasus.
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Affiliation(s)
- Meiyao Wang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu Province, China; Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, Jiangsu Province, China; Aquatic Animal Genome Center of Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214128, Jiangsu Province, China
| | - Pao Xu
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu Province, China; Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, Jiangsu Province, China; Aquatic Animal Genome Center of Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214128, Jiangsu Province, China.
| | - Zhixiang Zhu
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu Province, China
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7
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Goldsmith H, Wells A, Sá MJN, Williams M, Heussler H, Buckman M, Pfundt R, de Vries BBA, Goel H. Expanding the phenotype of intellectual disability caused by HIVEP2 variants. Am J Med Genet A 2019; 179:1872-1877. [PMID: 31207095 DOI: 10.1002/ajmg.a.61271] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/09/2019] [Accepted: 06/01/2019] [Indexed: 01/14/2023]
Abstract
De novo pathogenic variants in the human immunodeficiency virus enhancer type I binding protein 2 (HIVEP2) gene, a large transcription factor predominantly expressed in the brain have previously been associated with intellectual disability (ID) and dysmorphic features in nine patients. We describe the phenotype and genotype of two additional patients with novel de novo pathogenic HIVEP2 variants, who have previously unreported features, including hyperphagia and Angelman-like features. Exome sequencing was utilized in the investigation of the patients who had previously incurred a rigorous genetic workup for their neurodevelopmental delay, and in whom no genetic cause had been detected. Information pertaining to phenotype and genotype for new patients was collated along with data from previous reports, showing that the phenotypic spectrum of patients with HIVEP2 variants is broader than first noted. Additional characteristics are: an increased body mass index; and features of Angelman-like syndromes including: ID, limited speech, post-natal microcephaly, and hypotonia. Dysmorphic features vary between patients. As yet, no clear association between the type of gene aberration and phenotype can be concluded. HIVEP2-related ID needs to be considered in the differential diagnosis of patients with Angelman-like phenotypes and hyperphagia, and whole-exome sequencing should be considered in the genetic diagnostic armamentarium for patients with ID of inconclusive etiology.
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Affiliation(s)
| | - Anna Wells
- University of Newcastle, Callaghan, New South Wales, Australia
| | - Maria J N Sá
- Department of Human Genetics, Radboud University Medical Center (Radboudumc), Nijmegen, The Netherlands
| | - Mark Williams
- Mater Research Institute, The University of Queensland, Woolloongabba, Queensland, Australia.,Genetic Pathology, Mater Pathology, South Brisbane, Queensland, Australia
| | - Helen Heussler
- Child Development Program, Queensland Children's Hospital, South Brisbane, Queensland, Australia.,Child Health Research Centre, The University of Queensland, South Brisbane, Queensland, Australia
| | - Melissa Buckman
- Genetic Counselling Service, Tamworth, New South Wales, Australia
| | - Rolph Pfundt
- Department of Human Genetics, Radboud University Medical Center (Radboudumc), Nijmegen, The Netherlands
| | - Bert B A de Vries
- Department of Human Genetics, Radboud University Medical Center (Radboudumc), Nijmegen, The Netherlands
| | - Himanshu Goel
- Hunter Genetics, Waratah, New South Wales, Australia.,University of Newcastle, Callaghan, New South Wales, Australia
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8
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de Oliveira PG, Ramos MLS, Amaro AJ, Dias RA, Vieira SI. G i/o-Protein Coupled Receptors in the Aging Brain. Front Aging Neurosci 2019; 11:89. [PMID: 31105551 PMCID: PMC6492497 DOI: 10.3389/fnagi.2019.00089] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 04/03/2019] [Indexed: 12/18/2022] Open
Abstract
Cells translate extracellular signals to regulate processes such as differentiation, metabolism and proliferation, via transmembranar receptors. G protein-coupled receptors (GPCRs) belong to the largest family of transmembrane receptors, with over 800 members in the human species. Given the variety of key physiological functions regulated by GPCRs, these are main targets of existing drugs. During normal aging, alterations in the expression and activity of GPCRs have been observed. The central nervous system (CNS) is particularly affected by these alterations, which results in decreased brain functions, impaired neuroregeneration, and increased vulnerability to neuropathologies, such as Alzheimer's and Parkinson diseases. GPCRs signal via heterotrimeric G proteins, such as Go, the most abundant heterotrimeric G protein in CNS. We here review age-induced effects of GPCR signaling via the Gi/o subfamily at the CNS. During the aging process, a reduction in protein density is observed for almost half of the Gi/o-coupled GPCRs, particularly in age-vulnerable regions such as the frontal cortex, hippocampus, substantia nigra and striatum. Gi/o levels also tend to decrease with aging, particularly in regions such as the frontal cortex. Alterations in the expression and activity of GPCRs and coupled G proteins result from altered proteostasis, peroxidation of membranar lipids and age-associated neuronal degeneration and death, and have impact on aging hallmarks and age-related neuropathologies. Further, due to oligomerization of GPCRs at the membrane and their cooperative signaling, down-regulation of a specific Gi/o-coupled GPCR may affect signaling and drug targeting of other types/subtypes of GPCRs with which it dimerizes. Gi/o-coupled GPCRs receptorsomes are thus the focus of more effective therapeutic drugs aiming to prevent or revert the decline in brain functions and increased risk of neuropathologies at advanced ages.
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Affiliation(s)
- Patrícia G de Oliveira
- Department of Medical Sciences, Institute of Biomedicine (iBiMED) and The Discovery CTR, Universidade de Aveiro, Aveiro, Portugal
| | - Marta L S Ramos
- Department of Medical Sciences, Institute of Biomedicine (iBiMED) and The Discovery CTR, Universidade de Aveiro, Aveiro, Portugal
| | - António J Amaro
- School of Health Sciences (ESSUA), Universidade de Aveiro, Aveiro, Portugal
| | - Roberto A Dias
- Department of Medical Sciences, Institute of Biomedicine (iBiMED) and The Discovery CTR, Universidade de Aveiro, Aveiro, Portugal
| | - Sandra I Vieira
- Department of Medical Sciences, Institute of Biomedicine (iBiMED) and The Discovery CTR, Universidade de Aveiro, Aveiro, Portugal
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9
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Nocera S, Simon A, Fiquet O, Chen Y, Gascuel J, Datiche F, Schneider N, Epelbaum J, Viollet C. Somatostatin Serves a Modulatory Role in the Mouse Olfactory Bulb: Neuroanatomical and Behavioral Evidence. Front Behav Neurosci 2019; 13:61. [PMID: 31024270 PMCID: PMC6465642 DOI: 10.3389/fnbeh.2019.00061] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 03/12/2019] [Indexed: 11/30/2022] Open
Abstract
Somatostatin (SOM) and somatostatin receptors (SSTR1-4) are present in all olfactory structures, including the olfactory bulb (OB), where SOM modulates physiological gamma rhythms and olfactory discrimination responses. In this work, histological, viral tracing and transgenic approaches were used to characterize SOM cellular targets in the murine OB. We demonstrate that SOM targets all levels of mitral dendritic processes in the OB with somatostatin receptor 2 (SSTR2) detected in the dendrites of previously uncharacterized mitral-like cells. We show that inhibitory interneurons of the glomerular layer (GL) express SSTR4 while SSTR3 is confined to the granule cell layer (GCL). Furthermore, SOM cells in the OB receive synaptic inputs from olfactory cortical afferents. Behavioral studies demonstrate that genetic deletion of SSTR4, SSTR2 or SOM differentially affects olfactory performance. SOM or SSTR4 deletion have no major effect on olfactory behavioral performances while SSTR2 deletion impacts olfactory detection and discrimination behaviors. Altogether, these results describe novel anatomical and behavioral contributions of SOM, SSTR2 and SSTR4 receptors in olfactory processing.
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Affiliation(s)
- Sonia Nocera
- INSERM, UMR 894-Center for Psychiatry and Neuroscience (CPN), Paris, France
- Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Axelle Simon
- INSERM, UMR 894-Center for Psychiatry and Neuroscience (CPN), Paris, France
- Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Oriane Fiquet
- INSERM, UMR 894-Center for Psychiatry and Neuroscience (CPN), Paris, France
- Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Ying Chen
- INSERM, UMR 894-Center for Psychiatry and Neuroscience (CPN), Paris, France
- Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Jean Gascuel
- CNRS UMR 6265—Centre des Sciences du Goût et de l’Alimentation (CSGA), Dijon, France
| | - Frédérique Datiche
- CNRS UMR 6265—Centre des Sciences du Goût et de l’Alimentation (CSGA), Dijon, France
| | - Nanette Schneider
- CNRS UMR 6265—Centre des Sciences du Goût et de l’Alimentation (CSGA), Dijon, France
| | - Jacques Epelbaum
- INSERM, UMR 894-Center for Psychiatry and Neuroscience (CPN), Paris, France
- Université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Cécile Viollet
- INSERM, UMR 894-Center for Psychiatry and Neuroscience (CPN), Paris, France
- Université Paris Descartes-Sorbonne Paris Cité, Paris, France
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Kumar Nagarajan S, Babu S, Sohn H, Devaraju P, Madhavan T. Toward a better understanding of the interaction between somatostatin receptor 2 and its ligands: a structural characterization study using molecular dynamics and conceptual density functional theory. J Biomol Struct Dyn 2018; 37:3081-3102. [PMID: 30079808 DOI: 10.1080/07391102.2018.1508368] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This study is a part of the extensive research intending to provide the structural insights on somatostatin and its receptor. Herein, we have studied the structural complexity involved in the binding of somatostatin receptor 2 (SSTR2) with its agonists and antagonist. A 3D QSAR study based on comparative molecular field analysis and comparative molecular similarity analysis (CoMSIA) discerned that a SSTR2 ligand with electronegative, less-bulkier, and hydrogen atom donating/accepting substitutions is important for their biological activity. A conceptual density functional theory (DFT) study was followed to study the chemical behavior of the ligands based on the molecular descriptors derived using the Fukui's molecular orbital theory. We have performed molecular dynamics simulations of receptor-ligand complexes for 100 ns to analyze the dynamic stability of the backbone Cα atoms of the receptor and strength and approachability of the receptor-ligand complex. The findings of this study could be efficacious in the further studies understanding intricate structural features of the somatostatin receptors and in discovering novel subtype-specific ligands with higher affinity. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Santhosh Kumar Nagarajan
- a Department of Genetic Engineering School of Bioengineering , SRM Institute of Science and Technology , Kattankulathur, Chennai , India
| | - Sathya Babu
- a Department of Genetic Engineering School of Bioengineering , SRM Institute of Science and Technology , Kattankulathur, Chennai , India
| | - Honglae Sohn
- b Department of Chemistry and Department of Carbon Materials , Chosun University , Gwangju , South Korea
| | - Panneer Devaraju
- c Division of Microbiology and Molecular Biology , Vector Control Research Centre, Indian Council of Medical Research , Pondicherry , India
| | - Thirumurthy Madhavan
- a Department of Genetic Engineering School of Bioengineering , SRM Institute of Science and Technology , Kattankulathur, Chennai , India
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Angelim MKSC, Maia LMSDS, Mouffle C, Ginhoux F, Low D, Amancio-Dos-Santos A, Makhoul J, Le Corronc H, Mangin JM, Legendre P. Embryonic macrophages and microglia ablation alter the development of dorsal root ganglion sensory neurons in mouse embryos. Glia 2018; 66:2470-2486. [PMID: 30252950 DOI: 10.1002/glia.23499] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 06/29/2018] [Accepted: 07/03/2018] [Indexed: 12/15/2022]
Abstract
Microglia are known to regulate several aspects of the development of the central nervous system. When microglia colonize the spinal cord, from E11.5 in the mouse embryo, they interact with growing central axons of dorsal root ganglion sensory neurons (SNs), which suggests that they may have some functions in SN development. To address this issue, we analyzed the effects of embryonic macrophage ablation on the early development of SNs using mouse embryo lacking embryonic macrophages (PU.1 knock-out mice) and immune cell ablation. We discovered that, in addition to microglia, embryonic macrophages contact tropomyosin receptor kinase (Trk) C+ SN, TrkB+ SN, and TrkA+ SN peripheral neurites from E11.5. Deprivation of immune cells resulted in an initial reduction of TrkC+ SN and TrkB+ SN populations at E11.5 that was unlikely to be related to an alteration in their developmental cell death (DCD), followed by a transitory increase in their number at E12.5. It also resulted in a reduction of TrkA+ SN number during the developmental period analyzed (E11.5-E15.5), although we did not observe any change in their DCD. Proliferation of cells negative for brain fatty acid-binding protein (BFABP- ), which likely correspond to neuronal progenitors, was increased at E11.5, while their proliferation was decreased at E12.5, which could partly explain the alterations of SN subtype production observed from E11.5. In addition, we observed alterations in the proliferation of glial cell progenitors (BFABP+ cells) in the absence of embryonic macrophages. Our data indicate that embryonic macrophages and microglia ablation alter the development of SNs.
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Affiliation(s)
- Monara Kaélle Sérvulo Cruz Angelim
- Sorbonne Université, UPMC Univ Paris 06, INSERM, CNRS, Neurosciences Paris Seine, Institut de Biologie Paris Seine (NPS, IBPS), Paris, France.,Neurophysiology and pharmacology laboratory, Federal University of Pernambuco, Pernambuco, Brazil
| | - Luciana Maria Silva de Seixas Maia
- Sorbonne Université, UPMC Univ Paris 06, INSERM, CNRS, Neurosciences Paris Seine, Institut de Biologie Paris Seine (NPS, IBPS), Paris, France.,Neurophysiology and pharmacology laboratory, Federal University of Pernambuco, Pernambuco, Brazil
| | - Christine Mouffle
- Sorbonne Université, UPMC Univ Paris 06, INSERM, CNRS, Neurosciences Paris Seine, Institut de Biologie Paris Seine (NPS, IBPS), Paris, France
| | - Florent Ginhoux
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research, Singapore, Singapore
| | - Donovan Low
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research, Singapore, Singapore
| | | | - Jennifer Makhoul
- Sorbonne Université, UPMC Univ Paris 06, INSERM, CNRS, Neurosciences Paris Seine, Institut de Biologie Paris Seine (NPS, IBPS), Paris, France
| | - Hervé Le Corronc
- Sorbonne Université, UPMC Univ Paris 06, INSERM, CNRS, Neurosciences Paris Seine, Institut de Biologie Paris Seine (NPS, IBPS), Paris, France.,Université d'Angers, Angers, France
| | - Jean-Marie Mangin
- Sorbonne Université, UPMC Univ Paris 06, INSERM, CNRS, Neurosciences Paris Seine, Institut de Biologie Paris Seine (NPS, IBPS), Paris, France
| | - Pascal Legendre
- Sorbonne Université, UPMC Univ Paris 06, INSERM, CNRS, Neurosciences Paris Seine, Institut de Biologie Paris Seine (NPS, IBPS), Paris, France
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12
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Radial and tangential migration of telencephalic somatostatin neurons originated from the mouse diagonal area. Brain Struct Funct 2015; 221:3027-65. [PMID: 26189100 PMCID: PMC4920861 DOI: 10.1007/s00429-015-1086-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 07/07/2015] [Indexed: 01/11/2023]
Abstract
The telencephalic subpallium is the source of various GABAergic interneuron cohorts that invade the pallium via tangential migration. Based on genoarchitectonic studies, the subpallium has been subdivided into four major domains: striatum, pallidum, diagonal area and preoptic area (Puelles et al. 2013; Allen Developing Mouse Brain Atlas), and a larger set of molecularly distinct progenitor areas (Flames et al. 2007). Fate mapping, genetic lineage-tracing studies, and other approaches have suggested that each subpallial subdivision produces specific sorts of inhibitory interneurons, distinguished by differential peptidic content, which are distributed tangentially to pallial and subpallial target territories (e.g., olfactory bulb, isocortex, hippocampus, pallial and subpallial amygdala, striatum, pallidum, septum). In this report, we map descriptively the early differentiation and apparent migratory dispersion of mouse subpallial somatostatin-expressing (Sst) cells from E10.5 onward, comparing their topography with the expression patterns of the genes Dlx5, Gbx2, Lhx7-8, Nkx2.1, Nkx5.1 (Hmx3), and Shh, which variously label parts of the subpallium. Whereas some experimental results suggest that Sst cells are pallidal, our data reveal that many, if not most, telencephalic Sst cells derive from de diagonal area (Dg). Sst-positive cells initially only present at the embryonic Dg selectively populate radially the medial part of the bed nucleus striae terminalis (from paraseptal to amygdaloid regions) and part of the central amygdala; they also invade tangentially the striatum, while eschewing the globus pallidum and the preoptic area, and integrate within most cortical and nuclear pallial areas between E10.5 and E16.5.
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13
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Peineau S, Guimiot F, Csaba Z, Jacquier S, Fafouri A, Schwendimann L, de Roux N, Schulz S, Gressens P, Auvin S, Dournaud P. Somatostatin receptors type 2 and 5 expression and localization during human pituitary development. Endocrinology 2014; 155:33-9. [PMID: 24189142 DOI: 10.1210/en.2013-1683] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Somatostatin (SRIF), by acting mainly through sst2 and sst5 receptors, is a potent inhibitor of hormonal secretion by the human anterior pituitary gland. However, the pattern of protein expression of these SRIF receptors remains unknown during pituitary development. To get further insights into the physiological role of SRIF receptors in human development and pituitary function, the present study examined the developmental expression of the sst2 and sst5 receptors in the individual cell types of the anterior human pituitary. Thirteen fetal human pituitaries were investigated between 13 to 38 weeks of gestation (WG) by double-labeling immunofluorescence with antibodies raised against sst2 or sst5 receptors and GH, LH, FSH, TSH, or pro-opiomelanocortin proteins. SRIF immunoreactivity in the hypothalamus and median eminence was investigated at the same developmental ages. Immunoreactivity for the sst2 receptor was evident as early as 13 to 15 WG and onward mainly in TSH-, LH-, and FSH-expressing cells, whereas sst5 immunoreactivity was apparent at the late development stages (35-38 WG). GH-expressing cells mainly expressed sst5 immunoreactivity. SRIF-positive fibers and cells were detected as soon as 13 to 16 WG in the hypothalamus and median eminence and their densities increased with gestational age. The early appearance of hypothalamic SRIF cells and fibers suggests a physiological link between SRIF and its receptors during pituitary development. Whereas sst2 receptors might play a primary role in the differentiation and regulation of TSH, LH, and FSH cells, sst5 receptors appear to be mainly involved in GH regulation from birth onward.
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Affiliation(s)
- Stéphane Peineau
- Medical Research Council Centre for Synaptic Plasticity (S.P.), University of Bristol, School of Physiology and Pharmacology, Bristol BS8 1TD, United Kingdom; Inserm (S.P., F.G., Z.C., S.J., A.F., L.S., N.d.R., P.G., S.A., P.D.), U676, 75019 Paris, France; University Paris Diderot (S.P., F.G., Z.C., S.J., A.F., L.S., N.d.R., P.G., S.A., P.D.), Sorbonne Paris Cité, UMR676, 75019 Paris, France; and Institute of Pharmacology and Toxicology (S.S.), Jena University Hospital, Friedrich Schiller University Jena, Germany
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14
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Remke M, Hering E, Gerber NU, Kool M, Sturm D, Rickert CH, Gerß J, Schulz S, Hielscher T, Hasselblatt M, Jeibmann A, Hans V, Ramaswamy V, Taylor MD, Pietsch T, Rutkowski S, Korshunov A, Monoranu CM, Frühwald MC. Somatostatin receptor subtype 2 (sst₂) is a potential prognostic marker and a therapeutic target in medulloblastoma. Childs Nerv Syst 2013; 29:1253-62. [PMID: 23677175 DOI: 10.1007/s00381-013-2142-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 04/30/2013] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Neuroectodermal tumors in general demonstrate high and dense expression of the somatostatin receptor subtype 2 (sst₂). It controls proliferation of both normal and neoplastic cells. sst₂ has thus been suggested as a therapeutic target and prognostic marker for certain malignancies. METHODS To assess global expression patterns of sst 2 mRNA, we evaluated normal (n = 353) and tumor tissues (n = 340) derived from previously published gene expression profiling studies. These analyses demonstrated specific upregulation of sst 2 mRNA in medulloblastoma (p < 0.001). sst₂ protein was investigated by immunohistochemistry in two independent cohorts. RESULTS Correlation of sst₂ protein expression with clinicopathological variables revealed significantly higher levels in medulloblastoma (p < 0.05) compared with CNS-PNET, ependymoma, or pilocytic astrocytoma. The non-SHH medulloblastoma subgroup tumors showed particularly high expression of sst₂, when compared to other tumors and normal tissues. Furthermore, we detected a significant survival benefit in children with tumors exhibiting high sst₂ expression (p = 0.02) in this screening set. A similar trend was observed in a validation cohort including 240 independent medulloblastoma samples. CONCLUSION sst₂ is highly expressed in medulloblastoma and deserves further evaluation in the setting of prospective trials, given its potential utility as a prognostic marker and a therapeutic target.
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Affiliation(s)
- Marc Remke
- Division of Neurosurgery, Arthur and Sonia Labatt Brain Tumor Research Centre, Program in Developmental and Stem Cell Biology, Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
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15
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Simon AC, Loverdo C, Gaffuri AL, Urbanski M, Ladarre D, Carrel D, Rivals I, Leterrier C, Benichou O, Dournaud P, Szabo B, Voituriez R, Lenkei Z. Activation-dependent plasticity of polarized GPCR distribution on the neuronal surface. J Mol Cell Biol 2013; 5:250-65. [PMID: 23585691 DOI: 10.1093/jmcb/mjt014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Directionality of information flow through neuronal networks is sustained at cellular level by polarized neurons. However, specific targeting or anchoring motifs responsible for polarized distribution on the neuronal surface have only been identified for a few neuronal G-protein-coupled receptors (GPCRs). Here, through mutational and pharmacological modifications of the conformational state of two model GPCRs, the axonal CB1R cannabinoid and the somatodendritic SSTR2 somatostatin receptors, we show important conformation-dependent variations in polarized distribution. The underlying mechanisms include lower efficiency of conformation-dependent GPCR endocytosis in axons, compared with dendrites, particularly at moderate activation levels, as well as endocytosis-dependent transcytotic delivery of GPCRs from the somatodendritic domain to distal axonal portions, shown by using compartmentalized microfluidic devices. Kinetic modeling predicted that GPCR distribution polarity is highly regulated by steady-state endocytosis, which is conformation dependent and is able to regulate the relative amount of GPCRs targeted to axons and that axonally polarized distribution is an intermediary phenotype that appears at moderate basal activation levels. Indeed, we experimentally show that gradual changes in basal activation-dependent endocytosis lead to highly correlated shifts of polarized GPCR distribution on the neuronal surface, which can even result in a fully reversed polarized distribution of naturally somatodendritic or axonal GPCRs. In conclusion, polarized distribution of neuronal GPCRs may have a pharmacologically controllable component, which, in the absence of dominant targeting motifs, could even represent the principal regulator of sub-neuronal distribution. Consequently, chronic modifications of basal GPCR activation by therapeutic or abused drugs may lead to previously unanticipated changes in brain function through perturbation of polarized GPCR distribution on the neuronal surface.
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Affiliation(s)
- Anne C Simon
- Laboratoire de Neurobiologie, CNRS UMR7637, ESPCI-ParisTech, 10 Rue Vauquelin, Paris 75005, France
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16
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Alternative oxidase expression in the mouse enables bypassing cytochrome c oxidase blockade and limits mitochondrial ROS overproduction. PLoS Genet 2013; 9:e1003182. [PMID: 23300486 PMCID: PMC3536694 DOI: 10.1371/journal.pgen.1003182] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 11/06/2012] [Indexed: 12/21/2022] Open
Abstract
Cyanide-resistant non-phosphorylating respiration is known in mitochondria from plants, fungi, and microorganisms but is absent in mammals. It results from the activity of an alternative oxidase (AOX) that conveys electrons directly from the respiratory chain (RC) ubiquinol pool to oxygen. AOX thus provides a bypath that releases constraints on the cytochrome pathway and prevents the over-reduction of the ubiquinone pool, a major source of superoxide. RC dysfunctions and deleterious superoxide overproduction are recurrent themes in human pathologies, ranging from neurodegenerative diseases to cancer, and may be instrumental in ageing. Thus, preventing RC blockade and excess superoxide production by means of AOX should be of considerable interest. However, because of its energy-dissipating properties, AOX might produce deleterious effects of its own in mammals. Here we show that AOX can be safely expressed in the mouse (MitAOX), with major physiological parameters being unaffected. It neither disrupted the activity of other RC components nor decreased oxidative phosphorylation in isolated mitochondria. It conferred cyanide-resistance to mitochondrial substrate oxidation and decreased reactive oxygen species (ROS) production upon RC blockade. Accordingly, AOX expression was able to support cyanide-resistant respiration by intact organs and to afford prolonged protection against a lethal concentration of gaseous cyanide in whole animals. Taken together, these results indicate that AOX expression in the mouse is innocuous and permits to overcome a RC blockade, while reducing associated oxidative insult. Therefore, the MitAOX mice represent a valuable tool in order to investigate the ability of AOX to counteract the panoply of mitochondrial-inherited diseases originating from oxidative phosphorylation defects.
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17
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Shpakov AO, Shpakova EA. [Development of non-hormonal regulators of adenylyl cyclase signaling system on the basis of peptides, derivatives of the third intracellular loop of somatostatin receptors]. BIOMEDITSINSKAIA KHIMIIA 2012; 58:446-456. [PMID: 23413689 DOI: 10.18097/pbmc20125804446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In the majority of the serpentine type receptors the third intracellular loop (ICL-3) is responsible for interaction with heterotrimeric G-proteins and for transduction of hormonal signal to the enzymes, generators of the second messengers. It was found that the peptides corresponding to ICL-3 influence functional activity of hormonal signaling systems in the absence of the hormone and, in consequence, can be considered as prototypes for the development of selective regulators of these systems. We have originally synthesized peptides corresponding to C-terminal regions 255-269 and 240 254 of ICL-3 of type 1 and 2 rat somatostatin receptors (Som1R and Som2R). Micromolar concentrations of these peptides activated Gi-proteins and inhibited forskolin-stimulated activity of adenylyl cyclase (AC) in rat brain tissues. The peptide 255-269 of Som1R is a selective antagonist of Som1R, and the peptide 240-254 of Som2R is an agonist of Som1R. So, the peptide 255-269 of Som1R decreased the regulatory effects of somatostatin and selective Som1R-agonist CH-275 realized via the receptor homologous to them, while the peptide 240-254 of Som2R, on the contrary, increased AC inhibitory action of CH-275. Both peptides insignificantly influenced regulatory effects of the Som2R-agonist octreotide. Summing up, the peptides studied by us are selective regulators of somatostatin-sensitive AC system. Using the peptides it was shown that ICL-3 of Som1R and Som2R includes the main molecular determinants that are responsible for activation of Gi-proteins and regulation of AC system by somatostatin and its analogues.
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Abstract
The neuropeptide somatostatin (SRIF) is an important modulator of neurotransmission in the central nervous system and acts as a potent inhibitor of hormone and exocrine secretion. In addition, SRIF regulates cell proliferation in normal and tumorous tissues. The six somatostatin receptor subtypes (sst1, sst2A, sst2B, sst3, sst4, and sst5), which belong to the G protein-coupled receptor (GPCR) family, share a common molecular topology: a hydrophobic core of seven transmembrane-spanning α-helices, three intracellular loops, three extracellular loops, an amino-terminus outside the cell, and a carboxyl-terminus inside the cell. For most of the GPCRs, intracytosolic sequences, and more particularly the C-terminus, are believed to interact with proteins that are mandatory for either exporting neosynthesized receptor, anchoring receptor at the plasma membrane, internalization, recycling, or degradation after ligand binding. Accordingly, most of the SRIF receptors can traffic not only in vitro within different cell types but also in vivo. A picture of the pathways and proteins involved in these processes is beginning to emerge.
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Affiliation(s)
- Zsolt Csaba
- INSERM, Unité Mixte de Recherche U676, Paris, France
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deCampo D, Fudge J. Where and what is the paralaminar nucleus? A review on a unique and frequently overlooked area of the primate amygdala. Neurosci Biobehav Rev 2012; 36:520-35. [PMID: 21906624 PMCID: PMC3221880 DOI: 10.1016/j.neubiorev.2011.08.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 07/25/2011] [Accepted: 08/18/2011] [Indexed: 12/16/2022]
Abstract
The primate amygdala is composed of multiple subnuclei that play distinct roles in amygdala function. While some nuclei have been areas of focused investigation, others remain virtually unknown. One of the more obscure regions of the amygdala is the paralaminar nucleus (PL). The PL in humans and non-human primates is relatively expanded compared to lower species. Long considered to be part of the basal nucleus, the PL has several interesting features that make it unique. These features include a dense concentration of small cells, high concentrations of receptors for corticotropin releasing hormone and benzodiazepines, and dense innervation of serotonergic fibers. More recently, high concentrations of immature-appearing cells have been noted in the primate PL, suggesting special mechanisms of neural plasticity. Following a brief overview of amygdala structure and function, this review will provide an introduction to the history, embryology, anatomical connectivity, immunohistochemical and cytoarchitectural properties of the PL. Our conclusion is that the PL is a unique subregion of the amygdala that may yield important clues about the normal growth and function of the amygdala, particularly in higher species.
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Affiliation(s)
| | - Julie Fudge
- Department of Neurobiology and Anatomy
- Department of Psychiatry
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Gressens P, Le Verche V, Fraser M, Rousset CI, Schwendimann L, Bennet L, George SA, Wang X, Mallard C, Tilley BC, Dournaud P, Gunn AJ, Hagberg H, Levison SW. Pitfalls in the quest of neuroprotectants for the perinatal brain. Dev Neurosci 2011; 33:189-98. [PMID: 21968048 DOI: 10.1159/000333109] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 09/14/2011] [Indexed: 11/19/2022] Open
Abstract
Sick preterm and term newborns are highly vulnerable to neural injury, and thus there has been a major search for new, safe and efficacious neuroprotective interventions in recent decades. Preclinical studies are essential to select candidate drugs for clinical trials in humans. This article focuses on 'negative' preclinical studies, i.e. studies where significant differences cannot be detected. Such findings are critical to inform both clinical and preclinical investigators, but historically they have been difficult to publish. A significant amount of time and resources is lost when negative results or nonpromising therapeutics are replicated in separate laboratories because these negative results were not shared with the research community in an open and accessible format. In this article, we discuss approaches to strengthen conclusions from negative preclinical studies and, conversely, to reduce false-negative preclinical evaluations of potential therapeutic compounds. Without being exhaustive, we address three major issues in conducting and interpreting preclinical experiments, including: (a) the choice of animal models, (b) the experimental design, and (c) issues concerning statistical analyses of the experiments. This general introduction is followed by synopses of negative data obtained from studies of three potential therapeutics for perinatal brain injury: (1) the somatostatin analog octreotide, (2) an AMPA/kainate receptor antagonist, topiramate, and (3) a pyruvate derivative, ethyl pyruvate.
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Shpakov AO, Shpakova EA. Development of non-hormonal regulators of the adenylyl cyclase signaling system based on the peptides, derivatives of the third intracellular loop of somatostatin receptors. BIOCHEMISTRY (MOSCOW) SUPPLEMENT SERIES B: BIOMEDICAL CHEMISTRY 2011. [DOI: 10.1134/s1990750811030127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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22
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Morales-Delgado N, Merchan P, Bardet SM, Ferrán JL, Puelles L, Díaz C. Topography of Somatostatin Gene Expression Relative to Molecular Progenitor Domains during Ontogeny of the Mouse Hypothalamus. Front Neuroanat 2011; 5:10. [PMID: 21441981 PMCID: PMC3057523 DOI: 10.3389/fnana.2011.00010] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Accepted: 02/16/2011] [Indexed: 11/13/2022] Open
Abstract
The hypothalamus comprises alar, basal, and floor plate developmental compartments. Recent molecular data support a rostrocaudal subdivision into rostral (terminal) and caudal (peduncular) halves. In this context, the distribution of neuronal populations expressing somatostatin (Sst) mRNA was analyzed in the developing mouse hypothalamus, comparing with the expression pattern of the genes Orthopedia (Otp), Distal-less 5 (Dlx5), Sonic Hedgehog (Shh), and Nk2 homeobox 1 (Nkx2.1). At embryonic day 10.5 (E10.5), Sst mRNA was first detectable in the anterobasal nucleus, a Nkx2.1-, Shh-, and Otp-positive basal domain. By E13.5, nascent Sst expression was also related to two additional Otp-positive domains within the alar plate and one in the basal plate. In the alar plate, Sst-positive cells were observed in rostral and caudal ventral subdomains of the Otp-positive paraventricular complex. An additional basal Sst-expressing cell group was found within a longitudinal Otp-positive periretromamillary band that separates the retromamillary area from tuberal areas. Apart of subsequent growth of these initial populations, at E13.5 and E15.5 some Sst-positive derivatives migrate tangentially into neighboring regions. A subset of cells produced at the anterobasal nucleus disperses ventralward into the shell of the ventromedial hypothalamic nucleus and the arcuate nucleus. Cells from the rostroventral paraventricular subdomain reach the suboptic nucleus, whereas a caudal contingent migrates radially into lateral paraventricular, perifornical, and entopeduncular nuclei. Our data provide a topologic map of molecularly defined progenitor areas originating a specific neuron type during early hypothalamic development. Identification of four main separate sources helps to understand causally its complex adult organization.
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Affiliation(s)
- Nicanor Morales-Delgado
- Department of Medical Sciences, School of Medicine, Regional Centre for Biomedical Research and Institute for Research in Neurological Disabilities, University of Castilla-La Mancha Albacete, Spain
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