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Torres EM. Consequences of gaining an extra chromosome. Chromosome Res 2023; 31:24. [PMID: 37620607 PMCID: PMC10449985 DOI: 10.1007/s10577-023-09732-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 07/18/2023] [Accepted: 07/30/2023] [Indexed: 08/26/2023]
Abstract
Mistakes in chromosome segregation leading to aneuploidy are the primary cause of miscarriages in humans. Excluding sex chromosomes, viable aneuploidies in humans include trisomies of chromosomes 21, 18, or 13, which cause Down, Edwards, or Patau syndromes, respectively. While individuals with trisomy 18 or 13 die soon after birth, people with Down syndrome live to adulthood but have intellectual disabilities and are prone to multiple diseases. At the cellular level, mistakes in the segregation of a single chromosome leading to a cell losing a chromosome are lethal. In contrast, the cell that gains a chromosome can survive. Several studies support the hypothesis that gaining an extra copy of a chromosome causes gene-specific phenotypes and phenotypes independent of the identity of the genes encoded within that chromosome. The latter, referred to as aneuploidy-associated phenotypes, are the focus of this review. Among the conserved aneuploidy-associated phenotypes observed in yeast and human cells are lower viability, increased gene expression, increased protein synthesis and turnover, abnormal nuclear morphology, and altered metabolism. Notably, abnormal nuclear morphology of aneuploid cells is associated with increased metabolic demand for de novo synthesis of sphingolipids. These findings reveal important insights into the possible pathological role of aneuploidy in Down syndrome. Despite the adverse effects on cell physiology, aneuploidy is a hallmark of cancer cells. Understanding how aneuploidy affects cell physiology can reveal insights into the selective pressure that aneuploid cancer cells must overcome to support unlimited proliferation.
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Affiliation(s)
- Eduardo M Torres
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA.
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2
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Spears ME, Lee N, Hwang S, Park SJ, Carlisle AE, Li R, Doshi MB, Armando AM, Gao J, Simin K, Zhu LJ, Greer PL, Quehenberger O, Torres EM, Kim D. De novo sphingolipid biosynthesis necessitates detoxification in cancer cells. Cell Rep 2022; 40:111415. [PMID: 36170811 PMCID: PMC9552870 DOI: 10.1016/j.celrep.2022.111415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 07/21/2022] [Accepted: 09/02/2022] [Indexed: 11/29/2022] Open
Abstract
Sphingolipids play important signaling and structural roles in cells. Here, we find that during de novo sphingolipid biosynthesis, a toxic metabolite is formed with critical implications for cancer cell survival. The enzyme catalyzing the first step in this pathway, serine palmitoyltransferase complex (SPT), is upregulated in breast and other cancers. SPT is dispensable for cancer cell proliferation, as sphingolipids can be salvaged from the environment. However, SPT activity introduces a liability as its product, 3-ketodihydrosphingosine (3KDS), is toxic and requires clearance via the downstream enzyme 3-ketodihydrosphingosine reductase (KDSR). In cancer cells, but not normal cells, targeting KDSR induces toxic 3KDS accumulation leading to endoplasmic reticulum (ER) dysfunction and loss of proteostasis. Furthermore, the antitumor effect of KDSR disruption can be enhanced by increasing metabolic input (via high-fat diet) to allow greater 3KDS production. Thus, de novo sphingolipid biosynthesis entails a detoxification requirement in cancer cells that can be therapeutically exploited.
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Affiliation(s)
- Meghan E Spears
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Namgyu Lee
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Sunyoung Hwang
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Sung Jin Park
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Anne E Carlisle
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Rui Li
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Mihir B Doshi
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Aaron M Armando
- School of Medicine, Department of Pharmacology, University of California, San Diego, 9500 Gilman Drive, San Diego, CA 92093, USA
| | - Jenny Gao
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Karl Simin
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Lihua Julie Zhu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Paul L Greer
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Oswald Quehenberger
- School of Medicine, Department of Pharmacology, University of California, San Diego, 9500 Gilman Drive, San Diego, CA 92093, USA
| | - Eduardo M Torres
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Dohoon Kim
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01604, USA.
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Hwang S, Williams JF, Kneissig M, Lioudyno M, Rivera I, Helguera P, Busciglio J, Storchova Z, King MC, Torres EM. Suppressing Aneuploidy-Associated Phenotypes Improves the Fitness of Trisomy 21 Cells. Cell Rep 2020; 29:2473-2488.e5. [PMID: 31747614 PMCID: PMC6886690 DOI: 10.1016/j.celrep.2019.10.059] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 09/10/2019] [Accepted: 10/14/2019] [Indexed: 01/24/2023] Open
Abstract
An abnormal number of chromosomes, or aneuploidy, accounts for most spontaneous abortions, causes developmental defects, and is associated with aging and cancer. The molecular mechanisms by which aneuploidy disrupts cellular function remain largely unknown. Here, we show that aneuploidy disrupts the morphology of the nucleus. Mutations that increase the levels of long-chain bases suppress nuclear abnormalities of aneuploid yeast independent of karyotype identity. Quantitative lipidomics indicates that long-chain bases are integral components of the nuclear membrane in yeast. Cells isolated from patients with Down syndrome also show that abnormal nuclear morphologies and increases in long-chain bases not only suppress these abnormalities but also improve their fitness. We obtained similar results with cells isolated from patients with Patau or Edward syndrome, indicating that increases in long-chain bases improve the fitness of aneuploid cells in yeast and humans. Targeting lipid biosynthesis pathways represents an important strategy to suppress nuclear abnormalities in aneuploidy-associated diseases. The cellular defects associated with aneuploidy are not well defined. Hwang et al. show that aneuploid yeast and human cells have abnormal nuclear morphology. Targeting ceramide synthesis suppresses nuclear abnormalities and improves the proliferation of aneuploid cells, including cells isolated from patients with Down syndrome.
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Affiliation(s)
- Sunyoung Hwang
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Jessica F Williams
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Maja Kneissig
- Department of Molecular Genetics, TU Kaiserslautern, Kaiserslautern 67663, Germany
| | - Maria Lioudyno
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Isabel Rivera
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Pablo Helguera
- Instituto de Investigacion Medica Mercedes y Martin Ferreyra, INIMEC-CONICET, Universidad Nacional de Cordoba, Friuli 2434, Cordoba 5016, Argentina
| | - Jorge Busciglio
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA; Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA 92697, USA; Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA 92697, USA
| | - Zuzana Storchova
- Department of Molecular Genetics, TU Kaiserslautern, Kaiserslautern 67663, Germany
| | - Megan C King
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Eduardo M Torres
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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Duran CD, Binefa MF, Joan MM, Torres EM, Velescu A, Juscafresa LC, Pont CL, Velasco AC. Sarcopenia Predicts Lower Long-term Survival Among AAA Patients Submitted to EVAR. Eur J Vasc Endovasc Surg 2019. [DOI: 10.1016/j.ejvs.2019.06.1120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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5
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Torres HM, Evangelista K, Torres EM, Estrela C, Leite AF, Valladares-Neto J, Silva MAG. Reliability and validity of two software systems used to measure the pharyngeal airway space in three-dimensional analysis. Int J Oral Maxillofac Surg 2019; 49:602-613. [PMID: 31564477 DOI: 10.1016/j.ijom.2019.09.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 06/29/2019] [Accepted: 09/12/2019] [Indexed: 12/12/2022]
Abstract
The aim of this study was to test the reliability and validity of two software systems used to measure the pharyngeal airway space three-dimensionally. A sample of 40 cone beam computed tomography images from adult patients was taken from a database. The cone beam computed tomography images were analysed by InVivoDental and Dolphin 3D software systems by two calibrated examiners. Three nasopharynx and oropharynx prototypes were used as a reference standard to validate the software systems. The volume, minimum area and minimum area localization were the measurements tested. Measurements were compared using a paired t-test; correlated using Pearson's correlation and linear regression. Bland-Altman analysis was also used. We found significant differences in the oropharynx volume (P=0.002) and nasopharynx minimum area localization (P=0.009). The Dolphin 3D software presented higher-volume values than the ones found in the prototype, while the InVivoDental software presented lower values. Strong (r>0.7; P>0.001) or very strong (r>0.9; P>0.001) correlations were observed between the software systems. Bland-Altman analysis found good agreement between prototypes and the software systems. The measurements obtained from the Dolphin 3D and InVivoDental software systems are both reliable, strongly correlated, but should not be assumed as equal. Dolphin 3D software overestimates the nasopharynx and oropharynx volumes, while the InVivoDental software underestimates them.
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Affiliation(s)
- H M Torres
- Department of Stomatological Sciences, Dental School, Federal University of Goiás, Goiás, Brazil
| | - K Evangelista
- Department of Stomatological Sciences, Dental School, Federal University of Goiás, Goiás, Brazil
| | - E M Torres
- Department of Stomatological Sciences, Dental School, Federal University of Goiás, Goiás, Brazil
| | - C Estrela
- Department of Stomatological Sciences, Dental School, Federal University of Goiás, Goiás, Brazil
| | - A F Leite
- Department of Stomatological Sciences, Dental School, Federal University of Goiás, Goiás, Brazil
| | - J Valladares-Neto
- Department of Stomatological Sciences, Dental School, Federal University of Goiás, Goiás, Brazil
| | - M A G Silva
- Department of Stomatological Sciences, Dental School, Federal University of Goiás, Goiás, Brazil.
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6
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Hwang S, Gustafsson HT, O'Sullivan C, Bisceglia G, Huang X, Klose C, Schevchenko A, Dickson RC, Cavaliere P, Dephoure N, Torres EM. Serine-Dependent Sphingolipid Synthesis Is a Metabolic Liability of Aneuploid Cells. Cell Rep 2019; 21:3807-3818. [PMID: 29281829 DOI: 10.1016/j.celrep.2017.11.103] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 11/06/2017] [Accepted: 11/29/2017] [Indexed: 10/18/2022] Open
Abstract
Aneuploidy disrupts cellular homeostasis. However, the molecular mechanisms underlying the physiological responses and adaptation to aneuploidy are not well understood. Deciphering these mechanisms is important because aneuploidy is associated with diseases, including intellectual disability and cancer. Although tumors and mammalian aneuploid cells, including several cancer cell lines, show altered levels of sphingolipids, the role of sphingolipids in aneuploidy remains unknown. Here, we show that ceramides and long-chain bases, sphingolipid molecules that slow proliferation and promote survival, are increased by aneuploidy. Sphingolipid levels are tightly linked to serine synthesis, and inhibiting either serine or sphingolipid synthesis can specifically impair the fitness of aneuploid cells. Remarkably, the fitness of aneuploid cells improves or deteriorates upon genetically decreasing or increasing ceramides, respectively. Combined targeting of serine and sphingolipid synthesis could be exploited to specifically target cancer cells, the vast majority of which are aneuploid.
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Affiliation(s)
- Sunyoung Hwang
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - H Tobias Gustafsson
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Ciara O'Sullivan
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Gianna Bisceglia
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Xinhe Huang
- Department of Molecular and Cellular Biochemistry and the Lucille Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY 40506, USA
| | - Christian Klose
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany
| | - Andrej Schevchenko
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany
| | - Robert C Dickson
- Department of Molecular and Cellular Biochemistry and the Lucille Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY 40506, USA
| | - Paola Cavaliere
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10021, USA
| | - Noah Dephoure
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10021, USA
| | - Eduardo M Torres
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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7
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Zaytouni T, Tsai PY, Hitchcock DS, DuBois CD, Freinkman E, Lin L, Morales-Oyarvide V, Lenehan PJ, Wolpin BM, Mino-Kenudson M, Torres EM, Stylopoulos N, Clish CB, Kalaany NY. Critical role for arginase 2 in obesity-associated pancreatic cancer. Nat Commun 2017; 8:242. [PMID: 28808255 PMCID: PMC5556090 DOI: 10.1038/s41467-017-00331-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 06/21/2017] [Indexed: 12/13/2022] Open
Abstract
Obesity is an established risk factor for pancreatic ductal adenocarcinoma (PDA). Despite recent identification of metabolic alterations in this lethal malignancy, the metabolic dependencies of obesity-associated PDA remain unknown. Here we show that obesity-driven PDA exhibits accelerated growth and a striking transcriptional enrichment for pathways regulating nitrogen metabolism. We find that the mitochondrial form of arginase (ARG2), which hydrolyzes arginine into ornithine and urea, is induced upon obesity, and silencing or loss of ARG2 markedly suppresses PDA. In vivo infusion of 15N-glutamine in obese mouse models of PDA demonstrates enhanced nitrogen flux into the urea cycle and infusion of 15N-arginine shows that Arg2 loss causes significant ammonia accumulation that results from the shunting of arginine catabolism into alternative nitrogen repositories. Furthermore, analysis of PDA patient tumors indicates that ARG2 levels correlate with body mass index (BMI). The specific dependency of PDA on ARG2 rather than the principal hepatic enzyme ARG1 opens a therapeutic window for obesity-associated pancreatic cancer.Obesity is an established risk factor for pancreatic ductal adenocarcinoma (PDA). Here the authors show that obesity induces the expression of the mitochondrial form of arginase ARG2 in PDA and that ARG2 silencing or loss results in ammonia accumulation and suppression of obesity-driven PDA tumor growth.
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Affiliation(s)
- Tamara Zaytouni
- Division of Endocrinology, Center for Basic and Translational Obesity Research, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
- Broad Institute of Harvard and MIT, Cambridge, MA, 02142, USA
| | - Pei-Yun Tsai
- Division of Endocrinology, Center for Basic and Translational Obesity Research, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | | | - Cory D DuBois
- Division of Endocrinology, Center for Basic and Translational Obesity Research, Boston Children's Hospital, Boston, MA, 02115, USA
- Broad Institute of Harvard and MIT, Cambridge, MA, 02142, USA
| | - Elizaveta Freinkman
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
- Metabolon Inc, Research Triangle Park, Durham, NC, 27709, USA
| | - Lin Lin
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - Vicente Morales-Oyarvide
- Department of Medical Oncology, Dana-Farber Cancer Institute and Department of Medicine, Harvard Medical School, Boston, MA, 02215, USA
| | - Patrick J Lenehan
- Division of Endocrinology, Center for Basic and Translational Obesity Research, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - Brian M Wolpin
- Department of Medical Oncology, Dana-Farber Cancer Institute and Department of Medicine, Harvard Medical School, Boston, MA, 02215, USA
| | - Mari Mino-Kenudson
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA
| | - Eduardo M Torres
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Nicholas Stylopoulos
- Division of Endocrinology, Center for Basic and Translational Obesity Research, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
- Broad Institute of Harvard and MIT, Cambridge, MA, 02142, USA
| | - Clary B Clish
- Broad Institute of Harvard and MIT, Cambridge, MA, 02142, USA
| | - Nada Y Kalaany
- Division of Endocrinology, Center for Basic and Translational Obesity Research, Boston Children's Hospital, Boston, MA, 02115, USA.
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA.
- Broad Institute of Harvard and MIT, Cambridge, MA, 02142, USA.
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Abstract
Only a small proportion of dopamine neurons in nigral grafts typically survive transplantation into the adult striatum. Since many anaesthetics reduce blood flow and disturb a variety of brain metabolites, surgical anaesthesia may be one of the factors that compromise graft survival. Conversely, the lowered core body temperature induced by some anaesthetics might promote the survival of grafted cells by slowing their metabolism. In an initial screen, the widely-used surgical anaesthetic, equithesin, was found to reduce core temperature, mean arterial blood pressure, and to increase the partial pressure of oxygen in arterial blood without producing any significant alteration in arterial pH or the partial pressure of carbon dioxide. In the main experiment, rats with unilateral 6-hydroxydopamine lesions of the nigrostriatal bundle received dopamine-rich embryonic nigral grafts injected into the deafferented neostriatum via previously implanted guide cannulae, which allowed comparison to be made of graft survival after transplantation into awake and in re-anaesthetised animals. There were no significant differences between groups in either the functional effects of the grafts to compensate amphetamine-induced rotation, or in the survival and growth of the grafts as measured in post mortem histology. We therefore conclude that anaesthesia per se is not a major contributory factor in the relatively poor survival of dopamine neurons following transplantation into the rat striatum.
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Affiliation(s)
- S B Dunnett
- MRC Cambridge Centre for Brain Repair, and the Department of Experimental Psychology, University of Cambridge, UK.
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Cornish-Bowden A, Cornish-Bowden A, Rasnick D, Heng HH, Horne S, Abdallah B, Liu G, Ye CJ, Bloomfield M, Vincent MD, Aldaz CM, Karlsson J, Valind A, Jansson C, Gisselsson D, Graves JAM, Stepanenko AA, Andreieva SV, Korets KV, Mykytenko DO, Huleyuk NL, Baklaushev VP, Kovaleva OA, Chekhonin VP, Vassetzky YS, Avdieiev SS, Bakker B, Taudt AS, Belderbos ME, Porubsky D, Spierings DCJ, de Jong TV, Halsema N, Kazemier HG, Hoekstra-Wakker K, Bradley A, de Bont ESJM, van den Berg A, Guryev V, Lansdorp PM, Tatché MC, Foijer F, Liehr T, Baudoin NC, Nicholson JM, Soto K, Quintanilla I, Camps J, Cimini D, Dürrbaum M, Donnelly N, Passerini V, Kruse C, Habermann B, Storchová Z, Mandrioli D, Belpoggi F, Silbergeld EK, Perry MJ, Skotheim RI, Løvf M, Johannessen B, Hoff AM, Zhao S, SveeStrømme JM, Sveen A, Lothe RA, Hehlmann R, Voskanyan A, Fabarius A, Böcking A, Biesterfeld S, Berynskyy L, Börgermann C, Engers R, Dietz J, Fritz A, Sehgal N, Vecerova J, Stojkovicz B, Ding H, Page N, Tye C, Bhattacharya S, Xu J, Stein G, Stein J, Berezney R, Gong X, Grasedieck S, Swoboda J, Rücker FG, Bullinger L, Pollack JR, Roumelioti FM, Chiourea M, Raftopoulou C, Gagos S, Duesberg P, Bloomfield M, Hwang S, Gustafsson HT, O’Sullivan C, Acevedo-Colina A, Huang X, Klose C, Schevchenko A, Dickson RC, Cavaliere P, Dephoure N, Torres EM, Stampfer MR, Vrba L, LaBarge MA, Futscher B, Garbe JC, Zhou YH, Trinh AL, Zhou YH, Digman M. Abstracts from the 3rd Conference on Aneuploidy and Cancer: Clinical and Experimental Aspects. Mol Cytogenet 2017. [PMCID: PMC5499067 DOI: 10.1186/s13039-017-0320-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Annett LE, Torres EM, Clarke DJ, Ishida Y, Barker RA, Ridley RM, Baker HF, Dunnett SB. Survival of Nigral Grafts within the Striatum of Marmosets with 6-Ohda Lesions Depends Critically on Donor Embryo Age. Cell Transplant 2017; 6:557-69. [PMID: 9440865 DOI: 10.1177/096368979700600606] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The study examined the importance of embryonic donor age for the survival of nigral grafts in 6-OHDA–lesioned marmosets. The issue as to whether donor age is critical for the survival of nigral grafts in primates is controversial, because several early reports suggested that relatively old tissue could survive transplantation and produce functional benefits in monkeys, in contrast to the restrictive time dependence observed in rodents. Embryonic marmoset donors embryos of three different ages were employed: 1) E74 (Carnegie stage 18-19); 2) E83-84 (Carnegie stage 23+); 3) E92-93 (foetal period). The nigral neurons derived from the ventral mesencephalon in the two older donor age groups did not survive well when grafted to the striatum of adult marmosets with unilateral 6-OHDA lesions. Although a few tyrosine hydroxylase (TH+) neurons could be identified by immunohistochemistry at graft sites in all recipients in older donor age groups, the numbers of surviving neurons in these were small, on average typically less than 100 TH+ cells. These small grafts were not sufficient to affect amphetamine-induced rotation. In contrast, many more TH+ cells typically survived transplantation in the recipients; of graft tissue derived from the youngest donors and amphetamine-induced rotation was significantly reduced in this group alone. The time course and extent of the reduction in rotation was remarkably similar to that observed in previous marmoset nigral graft studies, confirming the utility of amphetamine-induced rotation as a sensitive and reliable indicator of nigral graft function in this species. Considering these results and other recent evidence from monkey to monkey, human to rat, and human to human graft studies, the survival of embryonic nigral tissues derived from primate donors transplanted into the striatum does appear to be critically dependent on the age of the donor tissue.
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Affiliation(s)
- L E Annett
- Department of Experimental Psychology, University of Cambridge, UK
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11
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Fjodorova M, Torres EM, Dunnett SB. Transplantation site influences the phenotypic differentiation of dopamine neurons in ventral mesencephalic grafts in Parkinsonian rats. Exp Neurol 2017; 291:8-19. [PMID: 28131726 PMCID: PMC5354310 DOI: 10.1016/j.expneurol.2017.01.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 01/17/2017] [Accepted: 01/24/2017] [Indexed: 01/26/2023]
Abstract
Foetal midbrain progenitors have been shown to survive, give rise to different classes of dopamine neurons and integrate into the host brain alleviating Parkinsonian symptoms following transplantation in patients and animal models of the disease. Dopamine neuron subpopulations in the midbrain, namely A9 and A10, can be identified anatomically based on cell morphology and ascending axonal projections. G protein-gated inwardly rectifying potassium channel Girk2 and the calcium binding protein Calbindin are the two best available histochemical markers currently used to label (with some overlap) A9- and A10-like dopamine neuron subtypes, respectively, in tyrosine hydroxylase expressing neurons both in the midbrain and grafts. Both classes of dopamine neurons survive in grafts in the striatum and extend axonal projections to their normal dorsal and ventral striatal targets depending on phenotype. Nevertheless, grafts transplanted into the dorsal striatum, which is an A9 input nucleus, are enriched for dopamine neurons that express Girk2. It remains to be elucidated whether different transplantation sites favour the differential survival and/or development of concordant dopamine neuron subtypes within the grafts. Here we used rat foetal midbrain progenitors at two developmental stages corresponding to a peak in either A9 or A10 neurogenesis and examined their commitment to respective dopaminergic phenotypes by grafting cells into different forebrain regions that contain targets of either nigral A9 dopamine innervation (dorsal striatum), ventral tegmental area A10 dopamine innervation (nucleus accumbens and prefrontal cortex), or only sparse dopamine but rich noradrenaline innervation (hippocampus). We demonstrate that young (embryonic day, E12), but not older (E14), mesencephalic tissue and the transplant environment influence survival and functional integration of specific subtypes of dopamine neurons into the host brain. We also show that irrespective of donor age A9-like, Girk2-expressing neurons are more responsive to environmental cues in adopting a dopaminergic phenotype during differentiation post-grafting. These novel findings suggest that dopamine progenitors use targets of A9/A10 innervation in the transplantation site to complete maturation and the efficacy of foetal cell replacement therapy in patients may be improved by deriving midbrain tissue at earlier developmental stages than in current practice.
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Affiliation(s)
- Marija Fjodorova
- Brain Repair Group, School of Biosciences, Cardiff University, Museum Avenue, Cardiff, Wales CF10 3AX, UK.
| | - Eduardo M Torres
- Brain Repair Group, School of Biosciences, Cardiff University, Museum Avenue, Cardiff, Wales CF10 3AX, UK
| | - Stephen B Dunnett
- Brain Repair Group, School of Biosciences, Cardiff University, Museum Avenue, Cardiff, Wales CF10 3AX, UK
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Wang F, Shin J, Shea JM, Yu J, Bošković A, Byron M, Zhu X, Shalek AK, Regev A, Lawrence JB, Torres EM, Zhu LJ, Rando OJ, Bach I. Regulation of X-linked gene expression during early mouse development by Rlim. eLife 2016; 5. [PMID: 27642011 PMCID: PMC5059138 DOI: 10.7554/elife.19127] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 09/15/2016] [Indexed: 01/22/2023] Open
Abstract
Mammalian X-linked gene expression is highly regulated as female cells contain two and male one X chromosome (X). To adjust the X gene dosage between genders, female mouse preimplantation embryos undergo an imprinted form of X chromosome inactivation (iXCI) that requires both Rlim (also known as Rnf12) and the long non-coding RNA Xist. Moreover, it is thought that gene expression from the single active X is upregulated to correct for bi-allelic autosomal (A) gene expression. We have combined mouse genetics with RNA-seq on single mouse embryos to investigate functions of Rlim on the temporal regulation of iXCI and Xist. Our results reveal crucial roles of Rlim for the maintenance of high Xist RNA levels, Xist clouds and X-silencing in female embryos at blastocyst stages, while initial Xist expression appears Rlim-independent. We find further that X/A upregulation is initiated in early male and female preimplantation embryos. DOI:http://dx.doi.org/10.7554/eLife.19127.001
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Affiliation(s)
- Feng Wang
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, United States
| | - JongDae Shin
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, United States.,Department of Cell Biology, College of Medicine, Konyang University, Daejeon, Korea
| | - Jeremy M Shea
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, United States
| | - Jun Yu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, United States
| | - Ana Bošković
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, United States
| | - Meg Byron
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, United States
| | - Xiaochun Zhu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, United States
| | - Alex K Shalek
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, United States.,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, United States.,Broad Institute of MIT and Harvard, Cambridge, United States.,Ragon Institute of MGH, MIT and Harvard, Cambridge, United States
| | - Aviv Regev
- Broad Institute of MIT and Harvard, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, United States
| | - Jeanne B Lawrence
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, United States
| | - Eduardo M Torres
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, United States
| | - Lihua J Zhu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, United States.,Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, United States
| | - Oliver J Rando
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, United States
| | - Ingolf Bach
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, United States
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13
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Lelos MJ, Roberton VH, Vinh NN, Harrison C, Eriksen P, Torres EM, Clinch SP, Rosser AE, Dunnett SB. Direct Comparison of Rat- and Human-Derived Ganglionic Eminence Tissue Grafts on Motor Function. Cell Transplant 2016; 25:665-75. [DOI: 10.3727/096368915x690297] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Huntington's disease (HD) is a debilitating, genetically inherited neurodegenerative disorder that results in early loss of medium spiny neurons from the striatum and subsequent degeneration of cortical and other subcortical brain regions. Behavioral changes manifest as a range of motor, cognitive, and neuropsychiatric impairments. It has been established that replacement of the degenerated medium spiny neurons with rat-derived fetal whole ganglionic eminence (rWGE) tissue can alleviate motor and cognitive deficits in preclinical rodent models of HD. However, clinical application of this cell replacement therapy requires the use of human-derived (hWGE), not rWGE, tissue. Despite this, little is currently known about the functional efficacy of hWGE. The aim of this study was to directly compare the ability of the gold standard rWGE grafts, against the clinically relevant hWGE grafts, on a range of behavioral tests of motor function. Lister hooded rats either remained as unoperated controls or received unilateral excitotoxic lesions of the lateral neostriatum. Subsets of lesioned rats then received transplants of either rWGE or hWGE primary fetal tissue into the lateral striatum. All rats were tested postlesion and postgraft on the following tests of motor function: staircase test, apomorphine-induced rotation, cylinder test, adjusting steps test, and vibrissae-evoked touch test. At 21 weeks postgraft, brain tissue was taken for histological analysis. The results revealed comparable improvements in apomorphine-induced rotational bias and the vibrissae test, despite larger graft volumes in the hWGE cohort. hWGE grafts, but not rWGE grafts, stabilized behavioral performance on the adjusting steps test. These results have implications for clinical application of cell replacement therapies, as well as providing a foundation for the development of stem cell-derived cell therapy products.
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Affiliation(s)
- Mariah J. Lelos
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Victoria H. Roberton
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Ngoc-Nga Vinh
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Carl Harrison
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Peter Eriksen
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Eduardo M. Torres
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Susanne P. Clinch
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Anne E. Rosser
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales, UK
- Neuroscience and Mental Health Institute, School of Medicine, Cardiff University, Cardiff, Wales, UK
| | - Stephen B. Dunnett
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales, UK
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14
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Abstract
Previous studies of laboratory strains of budding yeast had shown that when gene copy number is altered experimentally, RNA levels generally scale accordingly. This is true when the copy number of individual genes or entire chromosomes is altered. In a recent study, Hose et al. (2015) reported that this tight correlation between gene copy number and RNA levels is not observed in recently isolated wild Saccharomyces cerevisiae variants. To understand the origins of this proposed difference in gene expression regulation between natural variants and laboratory strains of S. cerevisiae, we evaluated the karyotype and gene expression studies performed by Hose et al. on wild S. cerevisiae strains. In contrast to the results of Hose et al., our reexamination of their data revealed a tight correlation between gene copy number and gene expression. We conclude that widespread dosage compensation occurs neither in laboratory strains nor in natural variants of S. cerevisiae. DOI:http://dx.doi.org/10.7554/eLife.10996.001 DNA inside cells is packaged into structures called chromosomes. Different species can have different numbers of chromosomes, but when any cell divides it must allocate the right number of chromosomes to each new cell. If this process goes wrong, cells end up with too many or too few chromosomes. The presence of extra copies of the genes on the additional chromosomes can cause the levels of the proteins encoded by those genes to rise abnormally, which can in turn lead to cell damage and disease. Proteins are produced using the information in genes via a two-step process. First, the gene’s DNA is copied to create molecules of RNA, and these molecules are then translated into proteins. In many organisms, the presence of extra chromosomes in a cell is matched by a corresponding increase in the RNA molecules encoded by the extra genes. Some organisms, however, counteract this effect through a process called dosage compensation. This process inactivates single genes or whole chromosomes by various means, and ensures that normal levels of RNA are produced, even in the presence of extra genes. In 2015, researchers from the University of Wisconsin-Madison reported that dosage compensation occurs in wild strains of budding yeast and effectively protects the yeast cells against the harmful effects of having extra chromosomes. However, these findings conflicted with earlier studies of laboratory strains of this yeast, which had reported that RNA levels increased along with gene number. Torres, Springer and Amon have re-analysed the data published in 2015, and now challenge the findings of the previous study involving the wild yeast strains. The new re-analysis instead showed that, like in laboratory yeast strains, gene number still correlates closely with RNA levels in the wild yeast. This led Torres, Springer and Amon to conclude that, in contrast with the previous report, there is currently no evidence that dosage compensation occurs in wild strains of yeast. So why do the results of these two studies disagree? Torres, Springer and Amon identified several issues concerning the original analysis made by the researchers from the University of Wisconsin-Madison. For example, some of the strains included in the 2015 study were unstable and were naturally losing the additional chromosomes that they’d acquired. Also, the thresholds set in the analysis to identify dosage compensated genes do not appear to have been stringent enough. Together, the new findings indicate that dosage compensation is a rare event in both wild and laboratory strains of yeast. DOI:http://dx.doi.org/10.7554/eLife.10996.002
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Affiliation(s)
- Eduardo M Torres
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, United States
| | - Michael Springer
- Department of Systems Biology, Harvard Medical School, Boston, United States
| | - Angelika Amon
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, United States
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15
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Lelos MJ, Morgan RJ, Kelly CM, Torres EM, Rosser AE, Dunnett SB. Amelioration of non-motor dysfunctions after transplantation of human dopamine neurons in a model of Parkinson's disease. Exp Neurol 2016; 278:54-61. [PMID: 26851542 PMCID: PMC4801014 DOI: 10.1016/j.expneurol.2016.02.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Revised: 01/25/2016] [Accepted: 02/02/2016] [Indexed: 11/29/2022]
Abstract
Background Patients suffering from Parkinson's disease (PD) display cognitive and neuropsychiatric dysfunctions, especially with disease progression. Although these impairments have been reported to impact more heavily upon a patient's quality of life than any motor dysfunctions, there are currently no interventions capable of adequately targeting these non-motor deficits. Objectives Utilizing a rodent model of PD, we investigated whether cell replacement therapy, using intrastriatal transplants of human-derived ventral mesencephalic (hVM) grafts, could alleviate cognitive and neuropsychiatric, as well as motor, dysfunctions. Methods Rats with unilateral 6-hydroxydopamine lesions to the medial forebrain bundle were tested on a complex operant task that dissociates motivational, visuospatial and motor impairments sensitive to the loss of dopamine. A subset of lesioned rats received intrastriatal hVM grafts of ~ 9 weeks gestation. Post-graft, rats underwent repeated drug-induced rotation tests and were tested on two versions of the complex operant task, before post-mortem analysis of the hVM tissue grafts. Results Post-graft behavioural testing revealed that hVM grafts improved non-motor aspects of task performance, specifically visuospatial function and motivational processing, as well as alleviating motor dysfunctions. Conclusions We report the first evidence of human VM cell grafts alleviating both non-motor and motor dysfunctions in an animal model of PD. This intervention, therefore, is the first to improve cognitive and neuropsychiatric symptoms long-term in a model of PD. Non-motor dysfunctions affect quality of life in Parkinson's disease. We tested whether human-derived foetal dopamine cells could improve these deficits. Human dopamine cells improved rotational bias and movement impairments in a rat model. Non-motor dysfunctions, specifically visuospatial and motivational deficits, improved. This is the first evidence of improved non-motor deficits from human dopamine cells.
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Affiliation(s)
- M J Lelos
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AX, UK.
| | - R J Morgan
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AX, UK
| | - C M Kelly
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AX, UK
| | - E M Torres
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AX, UK
| | - A E Rosser
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AX, UK
| | - S B Dunnett
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AX, UK
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Torres EM, Trigano M, Dunnett TB. Translation of Cell Therapies to the Clinic: Characteristics of Cell Suspensions in Large-Diameter Injection Cannulae. Cell Transplant 2015; 24:737-49. [DOI: 10.3727/096368914x685429] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
With the use of cell replacement therapies as a realistic prospect for conditions such as Parkinson's and Huntington's diseases, the logistics of the delivery of cell suspensions to deep brain targets is a topic for consideration. Because of the large cannulae required for such procedures, we need to consider the behavior of cell suspensions within the cannulae if we are to ensure that the injected cells are distributed as intended within the target tissue. We have investigated the behavior of primary embryonic cell suspensions of neural tissue, in cannulae of different diameters, using a protocol designed to mimic the handling and injection of cells during clinical application. Internal cannula diameter had a large effect on the distribution of cells during their dispensation from the syringe. In vertical or near vertical cannulae, cells settled toward the tip of the needle, and were dispensed unevenly, with the majority of cells emerging in the first 10-20% of the injectate. In horizontal or near-horizontal cannulae, we observed the opposite effect, such that few cells were dispensed in the first 80% of the injectate, and the majority emerged in the final 10-20%. Use of a glass cannula showed that the results obtained using the horizontal cannula were caused by settling and adherence of the cells on the side of the cannulae, such that during dispensation, the overlying, cell-free solution was dispensed first, prior to the emergence of the cells. We show that the behavior of cells in such cannulae is affected by the cannula diameter, and by the material of the cannula itself. In horizontal cannulae, uneven expulsion of cells from the needle can be ameliorated by regular rotation of the cannula during the procedure. We discuss the potential impact of these observations on the translation of cell therapies to the clinic.
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17
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Dephoure N, Hwang S, O'Sullivan C, Dodgson SE, Gygi SP, Amon A, Torres EM. Quantitative proteomic analysis reveals posttranslational responses to aneuploidy in yeast. eLife 2014; 3:e03023. [PMID: 25073701 PMCID: PMC4129440 DOI: 10.7554/elife.03023] [Citation(s) in RCA: 181] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Aneuploidy causes severe developmental defects and is a near universal feature of tumor cells. Despite its profound effects, the cellular processes affected by aneuploidy are not well characterized. Here, we examined the consequences of aneuploidy on the proteome of aneuploid budding yeast strains. We show that although protein levels largely scale with gene copy number, subunits of multi-protein complexes are notable exceptions. Posttranslational mechanisms attenuate their expression when their encoding genes are in excess. Our proteomic analyses further revealed a novel aneuploidy-associated protein expression signature characteristic of altered metabolism and redox homeostasis. Indeed aneuploid cells harbor increased levels of reactive oxygen species (ROS). Interestingly, increased protein turnover attenuates ROS levels and this novel aneuploidy-associated signature and improves the fitness of most aneuploid strains. Our results show that aneuploidy causes alterations in metabolism and redox homeostasis. Cells respond to these alterations through both transcriptional and posttranscriptional mechanisms. DOI:http://dx.doi.org/10.7554/eLife.03023.001 Nearly all tumor cells contain abnormal number of chromosomes. This state is called aneuploidy, and can also cause embryos to be miscarried, or to be born with severe developmental disorders. Proteins are produced from the genes contained within chromosomes, and so cells with too many chromosomes produce too many of some proteins. How do these cells cope with this excess? Previous work identified one strategy where a gene called UBP6 is mutated to prevent it from working correctly. The UBP6 gene normally encodes a protein that removes a small tag (called ubiquitin) from other proteins. This tag normally marks other proteins that should be degraded; thus, if UBP6 is not working, more proteins are broken down. Dephoure et al. investigated the effect of aneuploidy on the proteins produced by 12 different types of yeast cell, which each had an extra chromosome. In general, the amount of each protein produced by these yeast increased depending on the number of extra copies of the matching genes found on the extra chromosome. However, this was not the case for around 20% of the proteins, which were found in lower amounts than expected. Dephoure et al. revealed that this was not because fewer proteins were made, but because more were broken down. These proteins may be targeted for degradation because they are unstable, as many of these proteins need to bind to other proteins to keep them stable—but these stabilizing proteins are not also over-produced. Aneuploidy in cells also has other effects, including changing the cells' metabolism so that the cells grow more slowly and do not respond as well to stress. However, Dephoure et al. found that, as well as reducing the number of proteins produced, deleting the UBP6 gene also increased the fitness of the cells. Targeting the protein encoded by the UBP6 gene, or others that also stop proteins being broken down, could therefore help to reduce the negative effects of aneuploidy for a cell. Whether targeting these genes or proteins could also help to treat the diseases and disorders that result from aneuploidy, such as Alzheimer's and Huntington's disease, remains to be investigated. DOI:http://dx.doi.org/10.7554/eLife.03023.002
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Affiliation(s)
- Noah Dephoure
- Department of Cell Biology, Harvard Medical School, Boston, United States
| | - Sunyoung Hwang
- Program in Gene Function and Expression, University of Massachusetts Medical School, Worcester, United States
| | - Ciara O'Sullivan
- Program in Gene Function and Expression, University of Massachusetts Medical School, Worcester, United States
| | - Stacie E Dodgson
- David H. Koch Institute for Integrative Cancer Research, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, United States
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, United States
| | - Angelika Amon
- David H. Koch Institute for Integrative Cancer Research, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, United States
| | - Eduardo M Torres
- Program in Gene Function and Expression, University of Massachusetts Medical School, Worcester, United States
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Heuer A, Lelos MJ, Kelly CM, Torres EM, Dunnett SB. Dopamine-rich grafts alleviate deficits in contralateral response space induced by extensive dopamine depletion in rats. Exp Neurol 2013; 247:485-95. [PMID: 23360805 DOI: 10.1016/j.expneurol.2013.01.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 01/07/2013] [Accepted: 01/21/2013] [Indexed: 11/18/2022]
Abstract
Unilateral infusion of 6-hydroxydopamine into the nigro-striatal pathway in the rat is the most common dopamine lesion model of Parkinson's disease. In the present study, we explore the impact of near complete unilateral loss of dopamine along the nigro-striatal pathway and subsequent cell replacement therapy in a choice reaction time task in rats, with assessment of spatial responding towards either side of the body (ipsilateral or contralateral to the lesion) on alternate days. Results indicated a stable contralateral deficit in response accuracy, reaction times and motor function for 50 consecutive days of testing, with no signs of recovery or compensation. All lesioned rats developed a near-hole bias and displayed prolonged movement and reaction times when responses had to be directed towards a distal response location on the side of the body contralateral to the lesion, as well as a smaller ipsilateral impairment in response accuracy and movement times. Grafts of dopamine-rich tissue into the denervated striatum improved some, but not all, of the deficits induced by the lesion. Specifically, grafted rats performed at a similar level to control animals when assessed on the ipsilateral side, they demonstrated a partial restitution of their ability to respond to far contralateral stimuli, and they exhibited a marked reduction in the time to complete all lateralised responses on both sides. The present characterisation of the task and the effects of cell replacement via primary fetal mesencephalic tissue demonstrate restorative properties in alleviating the marked spatial response bias induced by unilateral loss of dopamine.
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Affiliation(s)
- Andreas Heuer
- The Brain Repair Group, School of Bioscience, Cardiff University, Cardiff, UK.
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19
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Torres EM, Lane EL, Heuer A, Smith GA, Murphy E, Dunnett SB. Increased efficacy of the 6-hydroxydopamine lesion of the median forebrain bundle in small rats, by modification of the stereotaxic coordinates. J Neurosci Methods 2011; 200:29-35. [PMID: 21723319 DOI: 10.1016/j.jneumeth.2011.06.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 06/09/2011] [Accepted: 06/14/2011] [Indexed: 01/20/2023]
Abstract
The 6-hydroxydopamine (6-OHDA) lesion is the most widely used rat model of Parkinson's disease. A single unilateral injection of 6-OHDA into the median forebrain bundle (MFB) selectively destroys dopamine neurons in the ipsilateral substantia nigra pars compacta (SNc) and ventral tegmental area (VTA), removing more than 95% of the dopamine innervation from target areas. The stereotaxic coordinates used to deliver 6-OHDA to the MFB have been used in our laboratory successfully for more than 25 years. However, in recent years we have observed a decline in the success rate of this lesion. Previously regular success rates of >80% of rats lesioned, have become progressively more variable, with rates as low as 20% recorded in some experiments. Having excluded variability of the neurotoxin and operator errors, we hypothesized that the change seen might be due to the use of smaller rats at the time of first surgery. An attempt to proportionally adjust the lesion coordinates base on head size did not increase lesion efficacy. However, in support of the small rat hypothesis it was observed that, using the standard coordinates, rat's heads had a "nose-up" position in the stereotaxic fame. Adjustment of the nose bar to obtain a flat head position during surgery improved lesion success, and subsequent adjustments of the lesion coordinates to account for smaller head size led to a greatly increased lesion efficacy (>90%) as assessed by amphetamine induced rotation.
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Affiliation(s)
- E M Torres
- Department of Biosciences, Cardiff University, Biomedical Sciences Building, Museum Avenue Cardiff CF10 3AX, UK.
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20
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Bayram-Weston Z, Torres EM, Jones L, Dunnett SB, Brooks SP. Light and electron microscopic characterization of the evolution of cellular pathology in the Hdh(CAG)150 Huntington's disease knock-in mouse. Brain Res Bull 2011; 88:189-98. [PMID: 21511013 DOI: 10.1016/j.brainresbull.2011.03.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 03/15/2011] [Accepted: 03/18/2011] [Indexed: 12/30/2022]
Abstract
Huntington's disease is an autosomal dominant, progressive neurodegenerative disease in which a single mutation in the gene responsible for the protein huntingtin leads to a primarily striatal and cortical neuronal loss, resulting progressive motor, cognitive and psychiatric disability and ultimately death. The mutation induces an abnormal protein accumulation within cells, although the precise role of this accumulation in the disease process is unknown. Several animal models have been created to model the disease. In the present study, the pathology of the Hdh(CAG(150)) mouse model was analyzed longitudinally over 24 months. At 5 months of age, the mutant N-terminal antibody S830 found dense nuclear staining and nuclear inclusions in the olfactory tubercle and striatum of the Hdh(Q150/Q150) mice. Nuclear inclusions increased in number and size with age and disease progression, and spread in ventral to dorsal, and anterior to posterior pattern. Electron microscopy observations at 14 months of age revealed that the neurons showed a normal nucleus having a circular shape and regular membranes in a densely packed cytoplasm, whereas by 21 months the cytoplasm was vacuolated and contained swollen mitochondria with many degenerated cytoplasmic organelles. Immunogold labelling of the S830 antibody was found to be specifically localised to the inner area of the neuronal intra-nuclear inclusions. Our data demonstrate a marked and progressive cellular phenotype that begins at 5 months of age and progresses with time. The pathology the Hdh(Q150/Q150) line was focused on the striatum and cortex until the late stage of the disease, consistent with the human condition.
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Abstract
Aneuploidy refers to karyotypic abnormalities characterized by gain or loss of individual chromosomes. This condition is associated with disease and death in all organisms in which it has been studied. We have characterized the effects of aneuploidy on yeast and primary mouse cells and found it to be detrimental at the cellular level. Furthermore, we find that aneuploid cells exhibit phenotypes consistent with increased energy need and proteotoxic stress. These observations, together with the finding that the additional chromosomes found in aneuploid cells are active, lead us to propose that aneuploidy causes an increased burden on protein synthesis and protein quality-control pathways and so induces an aneuploidy stress response.
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Affiliation(s)
- E M Torres
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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22
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Torres EM, Dephoure N, Panneerselvam A, Tucker CM, Whittaker CA, Gygi SP, Dunham MJ, Amon A. Identification of aneuploidy-tolerating mutations. Cell 2010; 143:71-83. [PMID: 20850176 DOI: 10.1016/j.cell.2010.08.038] [Citation(s) in RCA: 248] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Revised: 06/14/2010] [Accepted: 08/03/2010] [Indexed: 10/19/2022]
Abstract
Aneuploidy causes a proliferative disadvantage in all normal cells analyzed to date, yet this condition is associated with a disease characterized by unabated proliferative potential, cancer. The mechanisms that allow cancer cells to tolerate the adverse effects of aneuploidy are not known. To probe this question, we identified aneuploid yeast strains with improved proliferative abilities. Their molecular characterization revealed strain-specific genetic alterations as well as mutations shared between different aneuploid strains. Among the latter, a loss-of-function mutation in the gene encoding the deubiquitinating enzyme Ubp6 improves growth rates in four different aneuploid yeast strains by attenuating the changes in intracellular protein composition caused by aneuploidy. Our results demonstrate the existence of aneuploidy-tolerating mutations that improve the fitness of multiple different aneuploidies and highlight the importance of ubiquitin-proteasomal degradation in suppressing the adverse effects of aneuploidy.
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Affiliation(s)
- Eduardo M Torres
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Monville C, Torres EM, Pekarik V, Lane EL, Dunnett SB. Genetic, temporal and diurnal influences on L-dopa-induced dyskinesia in the 6-OHDA model. Brain Res Bull 2009; 78:248-53. [DOI: 10.1016/j.brainresbull.2008.11.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Revised: 11/12/2008] [Accepted: 11/18/2008] [Indexed: 10/21/2022]
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Torres EM, Dowd E, Dunnett SB. Recovery of functional deficits following early donor age ventral mesencephalic grafts in a rat model of Parkinson's disease. Neuroscience 2008; 154:631-40. [PMID: 18468807 DOI: 10.1016/j.neuroscience.2008.03.048] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 03/10/2008] [Accepted: 03/20/2008] [Indexed: 12/12/2022]
Abstract
It has previously been reported that dopaminergic grafts derived from early donor age, embryonic age 12-day-old (E12) rat embryos produced a fivefold greater yield of dopamine neurons than those derived from conventional E14 donors. The present study addresses whether E12 grafts are able to ameliorate lesion-induced behavioral deficits to the same extent as E14 grafts. In a unilateral rat model of Parkinson's disease, animals received grafts derived from either E12 or E14 donor embryos, dispersed at four sites in the lesioned striatum. Both E12 and E14 grafts were able to induce recovery on both amphetamine and apomorphine rotation tests, and to ameliorate deficits in the cylinder, stepping test, and corridor tests, but were unable to restore function in the paw reaching task. E12 grafts were equivalent to E14 grafts in their effects on lesion-induced deficits. However, E12 grafts resulted in cell yields greater than previously reported for untreated primary tissue, with mean TH-positive cell counts in excess of 25,000 neurons, compared with E14 TH cell counts of 4000-5000 cells, representing survival rates of 75% and 12.5%, respectively, based on the expected adult complement. The equivalence of graft induced behavioral recovery between the two graft groups is attributed to a threshold number of cells, above which no further improvement is seen. Such high dopamine cell survival rates should mean that multiple, functioning grafts can be derived from a single embryonic donor, and if similar yields could be obtained from human tissues then the goal of one embryo per patient would be achieved.
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Affiliation(s)
- E M Torres
- Department of Biosciences, Biomedical Sciences Building, Museum Avenue, Cardiff University, PO Box 911 Cardiff South Glamorgan, UK.
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Abstract
Aneuploidy is a condition frequently found in tumor cells, but its effect on cellular physiology is not known. We have characterized one aspect of aneuploidy: the gain of extra chromosomes. We created a collection of haploid yeast strains that each bear an extra copy of one or more of almost all of the yeast chromosomes. Their characterization revealed that aneuploid strains share a number of phenotypes, including defects in cell cycle progression, increased glucose uptake, and increased sensitivity to conditions interfering with protein synthesis and protein folding. These phenotypes were observed only in strains carrying additional yeast genes, which indicates that they reflect the consequences of additional protein production as well as the resulting imbalances in cellular protein composition. We conclude that aneuploidy causes not only a proliferative disadvantage but also a set of phenotypes that is independent of the identity of the individual extra chromosomes.
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Affiliation(s)
- Eduardo M Torres
- Center for Cancer Research, Howard Hughes Medical Institute, Massachusetts Institute of Technology, E17-233, 40 Ames Street, Cambridge, MA 02139, USA
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Torres EM, Monville C, Gates MA, Bagga V, Dunnett SB. Improved survival of young donor age dopamine grafts in a rat model of Parkinson's disease. Neuroscience 2007; 146:1606-17. [PMID: 17478050 DOI: 10.1016/j.neuroscience.2007.03.037] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 03/08/2007] [Accepted: 03/24/2007] [Indexed: 12/12/2022]
Abstract
In an attempt to improve the survival of implanted dopamine cells, we have readdressed the optimal embryonic donor age for dopamine grafts. In a rat model of Parkinson's disease, animals with unilateral 6-hydroxydopamine lesions of the median forebrain bundle received dopamine-rich ventral mesencephalic grafts derived from embryos of crown to rump length 4, 6, 9, or 10.5 mm (estimated embryonic age (E) 11, E12, E13 and E14 days post-coitus, respectively). Grafts derived from 4 mm embryos survived poorly, with less than 1% of the implanted dopamine cells surviving. Grafts derived from 9 mm and 10.5 mm embryos were similar to those seen in previous experiments with survival rates of 8% and 7% respectively. The best survival was seen in the group that received 6 mm grafts, which were significantly larger than all other graft groups. Mean dopamine cell survival in the 6 mm group (E12) was 36%, an extremely high survival rate for primary, untreated ventral mesencephalic grafts applied as a single placement, and more than fivefold larger than the survival rate observed in the 10.5 mm (E14) group. As E12 ventral mesencephalic tissues contain few, if any, differentiated dopamine cells we conclude that the large numbers of dopamine cells seen in the 6 mm grafts must have differentiated post-implantation. We consider the in vivo conditions which allow this differentiation to occur, and the implications for the future of clinical trials based on dopamine cell replacement therapy.
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Affiliation(s)
- E M Torres
- Department of Biosciences, Cardiff University, Museum Avenue, PO Box 911, Cardiff CF10 3US, UK.
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Torres EM, Dunnett SB. Amphetamine induced rotation in the assessment of lesions and grafts in the unilateral rat model of Parkinson's disease. Eur Neuropsychopharmacol 2007; 17:206-14. [PMID: 16750350 DOI: 10.1016/j.euroneuro.2006.04.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Revised: 03/29/2006] [Accepted: 04/11/2006] [Indexed: 11/18/2022]
Abstract
In the unilateral rat model of Parkinson's disease (PD), amphetamine induced rotation is widely used as an index of both lesion deficits and of graft-derived recovery. We have analysed the time course of the rotational response in lesioned rats, and in rats with lesions and dopamine grafts. In lesioned rats, the rotation exhibited a typical dose-dependent response, with low rates of rotation in the first 10 min after injection, rising gradually to a maximum after 20-30 min. Grafted rats exhibited a peak of rotation in the first 10 min after injection, which then fell to a minimum after 30 min. We demonstrate that the response seen in grafted rats is both drug and dose-dependent and show that the rotational profile results from interaction of the grafted and intact striata which exhibit differential temporal responses to the amphetamine.
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Torres EM, Meldrum A, Kirik D, Dunnett SB. An investigation of the problem of two-layered immunohistochemical staining in paraformaldehyde fixed sections. J Neurosci Methods 2006; 158:64-74. [PMID: 16797719 DOI: 10.1016/j.jneumeth.2006.05.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Revised: 05/15/2006] [Accepted: 05/15/2006] [Indexed: 11/28/2022]
Abstract
In sections of paraformaldehyde fixed brain tissue, stained using immunohistochemical methods, the distribution of staining within the sections is not uniform. Whilst stained cells are seen at the top and bottom surfaces, the central thicknesses of the sections contain little or no immunoreactivity. This presents a major problem for quantification, as each section contains a population of cells that is not visualized by the staining method. Following extensive investigation of this phenomenon, we report that the failure of full thickness, immunohistochemical staining is not a failure of the immunohistochemical methodology per se, nor is it related directly to the thickness of the sections used. Rather, the problem lies in the chemistry of the tissue itself, and originates during fixation of the tissues using paraformaldehyde-based perfusion methods, which render the cell membranes impermeable to one or more components of the staining protocol. We show that this impermeability is affected by addition of membrane-disrupting agents to the fixative, and by a reduction of exposure to paraformaldehyde during fixation. The present investigation contributes to the development of new fixation protocols, optimised for use in both immunohistochemical methods and morphometric analyses.
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Affiliation(s)
- Eduardo M Torres
- Cardiff University, School of Biosciences, Museum Avenue, Cardiff CF10 3US, United Kingdom.
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Abstract
Recently, the need to detail the precise ontogeny of nigrostriatal dopamine neurons has grown significantly. It is now thought that the gestational day on which the majority of these neurons are born is important not only for maximizing the yield of primary cells for transplantation but also for extracting suitable dopamine neural precursors (as stem cells) for expansion in vitro. Historically, peak ontogeny of substantia nigra pars compacta (SNc) dopamine neurons in the rat has been considered to occur around embryonic day (E)14. However, such a concept is at odds with recent studies that reveal not only that substantial numbers of tyrosine hydroxylase-immunopositive cells reside in the ventral mesencephalic region of rats at E14 but that many of these cells have matured extensive axonal projections to the ventral forebrain. Here, then, the ontogeny of SNc neurons in rats commonly used as a source of donor tissue for experimental cell transplantation in animal models of Parkinson's disease has been re-examined. Using a combination of bromodeoxyuridine (BrdU) administration at E11, E12, E13 or E14 with immunocytochemical stainings for both BrdU and tyrosine hydroxylase after 4 weeks of postnatal development, this characterization reveals that the vast majority (perhaps 80%) of SNc dopamine neurons are probably born on E12 in Sprague-Dawley rats. Such findings are important in refining the use of embryonic tissues for primary cell transplantation and may provide more precise timing for identifying the cellular and molecular events that drive neural stem cells toward a dopaminergic phenotype during development.
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Affiliation(s)
- Monte A Gates
- Schools of Medicine and Life Sciences, Keele University, Staffordshire, UK.
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Monville C, Torres EM, Dunnett SB. Comparison of incremental and accelerating protocols of the rotarod test for the assessment of motor deficits in the 6-OHDA model. J Neurosci Methods 2006; 158:219-23. [PMID: 16837051 DOI: 10.1016/j.jneumeth.2006.06.001] [Citation(s) in RCA: 185] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Revised: 05/30/2006] [Accepted: 06/02/2006] [Indexed: 11/18/2022]
Abstract
The rotarod test, in which animals must balance on a rotating drum, is widely used to assess motor deficit in neurodegenerative disease models in rodents. Performance is measured by the duration that an animal stays on the rod as a function of drum speed. Two different protocols are widely used, incremental fixed speeds or an accelerating protocol, but there is little information on their equivalence or the relative power, reliability and sensitivity of the two protocols. The present study was undertaken to compare the incremental fixed-speed and accelerating rotarod protocols on two different lesions of the ascending forebrain dopamine pathways. Three groups of rats were used, controls, rats with 6-OHDA lesions of nigrostriatal bundle, and rats with terminal 6-OHDA lesions within the striatum. Rats were tested at different time points after the lesion. We report that whereas the incremental protocol is more sensitive to detect the presence of a lesion, the accelerating protocol provides a more discriminative test to correlate motor deficits against lesion size.
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Dowd E, Monville C, Torres EM, Wong LF, Azzouz M, Mazarakis ND, Dunnett SB. Lentivector-mediated delivery of GDNF protects complex motor functions relevant to human Parkinsonism in a rat lesion model. Eur J Neurosci 2006; 22:2587-95. [PMID: 16307601 DOI: 10.1111/j.1460-9568.2005.04414.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although viral vector-mediated delivery of glial cell-line derived neurotrophic factor (GDNF) to the brain has considerable potential as a neuroprotective strategy in Parkinson's disease (PD), its ability to protect complex motor functions relevant to the human condition has yet to be established. In this study, we used an operant task that assesses the selection, initiation and execution of lateralized nose-pokes in Lister Hooded rats to assess the efficacy with which complex behaviours are protected against neurotoxic lesions by prior injection of a lentiviral vector expressing GDNF. Unilateral injection of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle (MFB) caused rats to attempt fewer trials and to make more procedural errors. Lesioned rats also developed a pronounced ipsilateral bias, with a corresponding drop in contralateral accuracy. They were also slower to react to contralateral stimuli and to execute movements bilaterally. Rats that were pre-treated 4 weeks prior to lesion surgery with an equine infectious anaemia virus (EIAV) vector carrying GDNF [EIAV-GDNF, injected into the striatum and above the substantia nigra (SN)] performed significantly better on all of these parameters than control rats. In addition to the operant task, EIAV-GDNF successfully rescued contralateral impairments in the corridor, staircase, stepping and cylinder tasks, and prevented drug-induced rotational asymmetry. This study confirms that GDNF can protect against 6-OHDA-induced impairments in complex as well as simple behaviours, and reinforces the use of EIAV-based vectors for the treatment of PD.
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Affiliation(s)
- Eilís Dowd
- Brain Repair Group, School of Biosciences, Cardiff University, Wales, UK.
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Torres EM, Monville C, Lowenstein PR, Castro MG, Dunnett SB. Delivery of sonic hedgehog or glial derived neurotrophic factor to dopamine-rich grafts in a rat model of Parkinson's disease using adenoviral vectors Increased yield of dopamine cells is dependent on embryonic donor age. Brain Res Bull 2005; 68:31-41. [PMID: 16325002 PMCID: PMC2902250 DOI: 10.1016/j.brainresbull.2005.08.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The poor survival of dopamine grafts in Parkinson's disease is one of the main obstacles to the widespread application of this therapy. One hypothesis is that implanted neurons, once removed from the embryonic environment, lack the differentiation factors needed to develop the dopaminergic phenotype. In an effort to improve the numbers of dopamine neurons surviving in the grafts, we have investigated the potential of adenoviral vectors to deliver the differentiation factor sonic hedgehog or the glial cell line-derived neurotrophic factor GDNF to dopamine-rich grafts in a rat model of Parkinson's disease. Adenoviral vectors containing sonic hedgehog, GDNF, or the marker gene LacZ were injected into the dopamine depleted striatum of hemiparkinsonian rats. Two weeks later, ventral mesencephalic cell suspensions were prepared from embryos of donor ages E12, E13, E14 or E15 and implanted into the vector-transduced striatum. Pre-treatment with the sonic hedgehog vector produced a three-fold increase in the numbers of tyrosine hydroxylase-positive (presumed dopaminergic) cells in grafts derived from E12 donors, but had no effect on E13-E15 grafts. By contrast, pre-treatment with the GDNF vector increased yields of dopamine cells in grafts derived from E14 and E15 donors but had no effect on grafts from younger donors. The results indicate that provision of both trophic and differentiation factors can enhance the yields of dopamine neurons in ventral mesencephalic grafts, but that the two factors differ in the age and stage of embryonic development at which they have maximal effects.
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Affiliation(s)
- E M Torres
- Department of Biosciences, Cardiff University, Biomedical Sciences Building, Museum Avenue, PO Box 911, Cardiff CF10 3US, UK.
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Dowd E, Monville C, Torres EM, Dunnett SB. The Corridor Task: A simple test of lateralised response selection sensitive to unilateral dopamine deafferentation and graft-derived dopamine replacement in the striatum. Brain Res Bull 2005; 68:24-30. [PMID: 16325001 DOI: 10.1016/j.brainresbull.2005.08.009] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this experiment, we report a novel drug-free behavioural test of lateralised neglect which is sensitive to unilateral dopamine-denervating lesions and subsequent graft-derived striatal dopamine replacement. For the task, white plastic lids containing sugar pellets were placed along the left and right sides of the floor of a long narrow corridor at regular intervals. Hungry female Sprague-Dawley rats were placed individually into the corridor where they were allowed to make up to 20 pellet retrievals. The number of retrievals each rat made from its left and right sides was counted. Complete mesencephalic or partial nigrostriatal lesions were induced by injection of 6-hydroxydopamine into the medial forebrain bundle or striatum, respectively. Both lesions induced a pronounced ipsilateral retrieval bias in the task. Five weeks after lesion surgery, half of the rats from each lesion group were given E14 ventral mesencephalic cell suspension transplants into the denervated striatum, and were then re-tested in the Corridor Task 5 and 10 weeks later. There was no amelioration of the side bias in rats with medial forebrain bundle lesions. In contrast, in nigrostriatal-lesioned rats, the graft significantly reduced the lesion-induced ipsilateral bias. We conclude that the Corridor Task is a sensitive test of lateralised sensorimotor response selection, and is suitable for assessing deficits and recovery associated with lesions and grafts within the nigrostriatal system.
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Affiliation(s)
- Eilís Dowd
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, CF10 3US Wales, UK.
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Torres EM, Monville C, Lowenstein PR, Castro MG, Dunnett SB. In vivo transgene expression from an adenoviral vector is altered following a 6-OHDA lesion of the dopamine system. ACTA ACUST UNITED AC 2005; 137:1-10. [PMID: 15950755 PMCID: PMC2902248 DOI: 10.1016/j.molbrainres.2004.10.046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2004] [Revised: 10/12/2004] [Accepted: 10/17/2004] [Indexed: 10/25/2022]
Abstract
We have investigated the in vivo dynamics of an adenovirus-based, LacZ expressing vector, RAd36, at different doses, when injected unilaterally into the corpus striatum of normal rats. We have further investigated the characteristics of this vector in the presence of a 6-OHDA lesion of the nigrostriatal pathway. The dopamine-depleting lesion had an effect on both the number and the distribution of cells transduced by the adenoviral vector. The lesioned side of the brain contained significantly greater numbers of beta-galactosidase positive cells than the unlesioned side at 3 days, 1 week and 4 weeks post-injection and the distribution of transduced cells was altered by the presence of a dopamine lesion. We conclude that the increased levels of transgene expression seen in the lesioned hemisphere are due to a change in the diffusion characteristics of the injected vector in the lesioned hemisphere. These results indicate that, when investigating the use of virus-based vectors, ultimately for use in gene therapies in the CNS, the in vivo dynamics of the vector need to be assessed not only in the normal brain, but also in the pathological brain state such as animal models of target diseases.
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Affiliation(s)
- E M Torres
- Department of Biosciences, Cardiff University Museum Avenue, PO Box 911 Cardiff CF10 3US, UK.
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Monville C, Torres EM, Dunnett SB. Validation of the l-dopa-induced dyskinesia in the 6-OHDA model and evaluation of the effects of selective dopamine receptor agonists and antagonists. Brain Res Bull 2004; 68:16-23. [PMID: 16325000 DOI: 10.1016/j.brainresbull.2004.10.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2004] [Revised: 10/13/2004] [Accepted: 10/13/2004] [Indexed: 10/26/2022]
Abstract
Current treatments for Parkinson's disease (PD) rely on a dopamine replacement strategy and are reasonably effective, particularly in the early stages of the disease. However, chronic dopaminergic therapy is limited by the development of a range of side effects, including dyskinesia. This has led to a search for alternative treatments. Transplantation of foetal nigral dopamine neurons is a rational approach and many studies have shown that it can improve motor functions in parkinsonian rodents, primates and man. Recently, however, two clinical trials have reported an exacerbation of dyskinesias in some transplanted patients, raising concerns about the safety of the transplantation strategy. To study this issue, we have reproduced the l-dopa-induced dyskinesia model developed by Cenci et al. [M.A. Cenci, C.S. Lee, A. Bjorklund, l-DOPA-induced dyskinesia in the rat is associated with striatal overexpression of prodynorphin- and glutamic acid decarboxylase mRNA, Eur. J. Neurosci. 10 (1998) 2694-2706] in the rat. We find that their abnormal involuntary movements rating scale is easy to apply and consistent to use. Moreover, the Schallert forelimb placing test has been used to assess l-dopa-induced recovery of function and we find that the rats continue to show good recovery on this test, even while they are exhibiting abnormal dyskinetic side effects. To further evaluate this model, we have studied the effects of selective dopamine receptor antagonists and agonists for D1, D2 and D3 receptors. Antagonists of all three receptors are able to block the l-dopa-induced dyskinesia without interfering with the beneficial effects of l-dopa on the placing test. This indicates that the effects of chronic l-dopa on recovery of parkinsonian symptoms and on induction of dyskinetic side effects can be dissociated, which may provide the basis for developing novel combination treatments, e.g. using grafts while blocking the unwanted adverse effects of the drugs.
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Affiliation(s)
- Christelle Monville
- Cardiff University, School of Biosciences, Museum Avenue, Cardiff CF10 3US, UK.
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Gates MA, Coupe VM, Torres EM, Fricker-Gates RA, Dunnett SB. Spatially and temporally restricted chemoattractive and chemorepulsive cues direct the formation of the nigro-striatal circuit. Eur J Neurosci 2004; 19:831-44. [PMID: 15009130 DOI: 10.1111/j.1460-9568.2004.03213.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Identifying cellular and molecular mechanisms that direct the formation of circuits during development is thought to be the key to reconstructing circuitry lost in adulthood to neurodegenerative disorders or common traumatic injuries. Here we have tested whether brain regions situated in and around the developing nigro-striatal pathway have particular chemoattractive or chemorepulsive effects on mesencephalic dopamine axons, and whether these effects are temporally restricted. Mesencephalic explants from embryonic day (E)12 rats were either cultured alone or with coexplants from the embryonic, postnatal or adult medial forebrain bundle region (MFB), striatum, cortex, brain stem or thalamus. Statistical analysis of axon growth responses revealed a potent chemoattraction to the early embryonic MFB (i.e. E12-15) that diminished (temporally) in concert with the emergence of chemoattraction to the striatum in the late embryonic period (i.e. E19+). Repulsive responses by dopaminergic axons were obvious in cocultures with embryonic brain stem and cortex, however, there was no effect by the thalamus. Such results suggest that the nigro-striatal circuit is formed via spatially and temporally distributed chemoattractive and chemorepulsive elements that: (i) orientate the circuit in a rostral direction (via brain stem repulsion); (ii) initiate outgrowth (via MFB attraction); (iii) prevent growth beyond the target region (via cortical repulsion); and (iv) facilitate target innervation (via striatal chemoattraction). Subsequent studies will focus on identifying genes responsible for these events so that their products may be exploited to increase the integration of neuronal transplants to the mature brain, or provide a means to (re)establish the nigro-striatal circuit in vivo.
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Affiliation(s)
- Monte A Gates
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, Wales, CF10 3US, UK.
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Scarpini CG, May J, Lachmann RH, Preston CM, Dunnett SB, Torres EM, Efstathiou S. Latency associated promoter transgene expression in the central nervous system after stereotaxic delivery of replication-defective HSV-1-based vectors. Gene Ther 2001; 8:1057-71. [PMID: 11526453 DOI: 10.1038/sj.gt.3301497] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2000] [Accepted: 05/10/2001] [Indexed: 11/09/2022]
Abstract
The herpes simplex virus type 1 (HSV-1) latency associated promoter (LAP) has been shown to sustain long-term reporter gene expression within sensory neurones. Its activity within the CNS is, however, less well understood. In this study we characterise the activity of the LAP after stereotaxic delivery of recombinant HSV-1-based vectors to the brain. Two classes of vectors were utilised in these studies: (1) a replication-defective vector lacking the glycoprotein H and thymidine kinase genes, designated CS1, and (2) a virus mutant severely impaired for immediate-early (IE) gene expression which lacks functional VP16, ICP4 and ICP0 genes, designated in1388. Both vectors contain the LacZ gene under the control of the LAP. Following delivery of either vector to the striatum, beta-gal expression was detected within anatomically related CNS regions distal to the site of injection. At these sites the number of beta-gal-positive cells increased with time and remained stable up to 4 weeks p.i. beta-Gal expression could not be detected at the site of injection after delivery of CS1 but beta-gal expression within neurones located at this site was observed after delivery of in1388, indicating reduced toxicity of this severely disabled virus. Transgene expression decreased dramatically with both vectors at later time-points (>4 weeks after delivery), but PCR analysis demonstrated that viral genomes were stably maintained for up to 180 days following delivery, indicating that the loss of beta-gal-positive neurones was not likely to be due to a loss of vector-transduced cells. Moreover, after delivery of an equivalent virus to the rat striatum in situ hybridisation analysis showed a similar decrease in the number of neurones expressing the endogenous LATs with time. These data indicate that although the HSV-1 LAP can drive the expression of foreign genes in a variety of CNS neurones, in these cells there is a slow down-regulation of the viral promoter which eventually results in the loss of detectable transgene expression.
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Affiliation(s)
- C G Scarpini
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge, UK
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Bucher K, Sofroniew MV, Pannell R, Impey H, Smith AJ, Torres EM, Dunnett SB, Jin Y, Baer R, Rabbitts TH. The T cell oncogene Tal2 is necessary for normal development of the mouse brain. Dev Biol 2000; 227:533-44. [PMID: 11071772 DOI: 10.1006/dbio.2000.9920] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Transcription factors are commonly involved in leukemia by activation through chromosomal translocations and normally function in cell type(s) that differ from that of the tumor. TAL2 is a member of a basic helix-loop-helix gene family specifically involved in T cell leukemogenesis. Null mutations of Tal2 have been made in mice to determine its function during development. Tal2 null mutant mice show no obvious defects of hematopoiesis. During embryogenesis, Tal2 expression is restricted to the developing midbrain, dorsal diencephalon, and rostroventral diencephalic/telencephalic boundary, partly along presumptive developing fiber tracts. The null mutant mice are viable at birth but growth become progressively retarded and they do not survive to reproductive age. Tal2-deficient mice show a distinct dysgenesis of the midbrain tectum. Due to loss of superficial gray and optical layers, the superior colliculus is reduced in size and the inferior colliculus is abnormally rounded and protruding. Death is most likely due to progressive hydrocephalus which appears to be caused by obstruction of the foramen of Monro (the connection between the ventricles of the forebrain). Thus, in addition to its oncogenicity when ectopically expressed, Tal2 normally plays a pivotal role in brain development and without this gene, mice cannot survive to maturity.
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Affiliation(s)
- K Bucher
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 2QH, United Kingdom
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Abstract
The effects of long-term administration of the dopamine D(2) receptor antagonist haloperidol on Parkinsonian symptoms have been shown to persist after cessation of the drug treatment. In order to determine whether the level of tyrosine hydroxylase could be affected by subchronic administration of haloperidol, we examined tyrosine hydroxylase-positive immunoreactive cells in the substantia nigra after blockade of dopaminergic receptors with this antipsychotic. Three weeks of injections with haloperidol (1.5 mg/kg, i.p.) caused a significant decrease in tyrosine hydroxylase-positive cell counts at 24 h (27%), 5 days (21%) and 2 weeks (10%) after the last administration, an effect that was blocked by concurrent administration of the antioxidant, vitamin C. The level of tyrosine hydroxylase returned to baseline after 4 weeks withdrawal, no change being observed at later time-points. Nissl staining demonstrated that no damage to the cell bodies was observed, suggesting that the decrease in tyrosine hydroxylase-positive cells was not due to dopaminergic cell loss. These results demonstrate a depleting action of a short course of haloperidol on nigral tyrosine hydroxylase that outlasts the period of application by 2-4 weeks. Moreover, the current study has shown the effect of the antioxidant vitamin C in protecting haloperidol effects on tyrosine hydroxylase-immunostaining.
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Affiliation(s)
- L Besret
- Centre for Brain Repair, University of Cambridge, Cambridge, UK.
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Kendall AL, David F, Rayment G, Torres EM, Annett LE, Dunnett SB. The influence of excitotoxic basal ganglia lesions on motor performance in the common marmoset. Brain 2000; 123 ( Pt 7):1442-58. [PMID: 10869056 DOI: 10.1093/brain/123.7.1442] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Huntington's disease is a genetically inherited neurodegenerative disorder for which currently there is no effective treatment or cure. In order to gauge the potential therapeutic benefits of neuroprotective or restorative treatments, it is necessary to create an animal model that is associated with readily measurable and long-lasting functional impairments. The undifferentiated neostriatum and limited behavioural repertoire of rodents have led to the extension of our investigations into the common marmoset. We have used quinolinic acid to create unilateral excitotoxic lesions of the caudate nucleus or the putamen in this small non-human primate. Following rigorous investigation of each monkey on a battery of behavioural tests, we found that the unilateral putamen lesion was associated with a contralateral motor impairment that persisted for at least 9 months and withstood repeated testing. However, the unilateral caudate nucleus lesion did not appear to be associated with any detectable motor deficit. The stability and the reproducibility of the unilateral putamen lesion in the marmoset provide a suitable tool for the investigation of potential treatments for neurodegenerative disorders that attack this region of the brain.
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Affiliation(s)
- A L Kendall
- Department of Experimental Psychology and Cambridge Centre for Brain Repair, University of Cambridge, Cambridge, UK.
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Brasted PJ, Watts C, Torres EM, Robbins TW, Dunnett SB. Behavioral recovery after transplantation into a rat model of Huntington's disease: dependence on anatomical connectivity and extensive postoperative training. Behav Neurosci 2000; 114:431-6. [PMID: 10832803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Rats were trained to perform a conditioned stimulus-response task known to be sensitive to striatal damage, after which they received unilateral excitotoxic striatal lesions. The subsequent implantation of graft tissue into the lesioned striatum was either immediate (9 days) or substantially delayed (70 days). When retested 14 weeks later, all graft and lesion rats were equally impaired initially and biased their responding toward the ipsilateral side. Graft-associated recovery was evident with repeated postoperative testing, but only in rats that had received transplants 9 days postlesion. It is suggested that this training-dependent, graft-associated recovery is mediated specifically by the restored host-graft connections.
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Affiliation(s)
- P J Brasted
- Department of Experimental Psychology, University of Cambridge, United Kingdom
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Brasted PJ, Watts C, Torres EM, Robbins TW, Dunnett SB. Behavioral recovery after transplantation into a rat model of Huntington's disease: Dependence on anatomical connectivity and extensive postoperative training. Behav Neurosci 2000. [DOI: 10.1037/0735-7044.114.2.431] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Brasted PJ, Watts C, Torres EM, Robbins TW, Dunnett SB. Behavioural recovery following striatal transplantation: effects of postoperative training and P-zone volume. Exp Brain Res 1999; 128:535-8. [PMID: 10541748 DOI: 10.1007/s002210050877] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Rats were trained on an operant task and then received striatal lesions and grafts. Grafts were derived either from whole-ganglionic eminences or restricted to the lateral eminence. When retested 4 months later; graft-associated behavioural recovery was only apparent with extensive retesting. There was no difference in performance between rats that received whole-dissection or lateral-dissection grafts, and no correlation between performance and the amount of striatal-like (P-zone) tissue within the graft. It is suggested that P-zone reconstruction may be necessary, but not sufficient for behavioural recovery, which may additionally depend upon rehabilitative training.
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Affiliation(s)
- P J Brasted
- MRC Cambridge Centre for Brain Repair, Forvie Site, Robinson Way, Cambridge CB2 2PY, UK
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Kiernan BW, Garcion E, Ferguson J, Frost EE, Torres EM, Dunnett SB, Saga Y, Aizawa S, Faissner A, Kaur R, Franklin RJ, ffrench-Constant C. Myelination and behaviour of tenascin-C null transgenic mice. Eur J Neurosci 1999; 11:3082-92. [PMID: 10510172 DOI: 10.1046/j.1460-9568.1999.00729.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The extracellular matrix glycoprotein tenascin-C is widely expressed during development and repair, making it surprising that few abnormalities have been found in transgenic mice lacking this molecule. We have therefore re-examined the transgenic mice described by Saga et al. [Saga, Y., Yagi, T., Ikawa, Y., Sakakura, T. & Aizawa, S. (1992) Genes Dev., 6 1821-1831] in which tenascin-C was knocked-out by homologous recombination, focusing on two aspects of the nervous system likely to reveal any abnormalities that might follow the loss of tenascin-C. First, we have determined the pattern of myelin and distribution of oligodendrocyte precursor cells in those areas, such as the optic nerve and retina where local concentrations of tenascin-C have been proposed to act as barriers to oligodendrocyte precursor migration and so prevent inappropriate myelination. Secondly, we have examined the behaviour of the mice in a number of well-characterized tests, e.g. beam-walking, passive avoidance and the Morris water maze. We find no abnormalities of myelination or oligodendrocyte precursor distribution in adult mice, showing that local concentrations of tenascin-C are not the sole mechanism responsible for the pattern of myelination in these regions of CNS. However, we do find a number of behavioural abnormalities in these mice and show that hyperlocomotion and deficits in coordination during beam walking can be ascribed to tenascin-C deficiency. The effects on coordination are, however, not seen on a 129 genetic background. Taken together, these results significantly extend the phenotype associated with tenascin-C deficiency but argue against a role in myelination.
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Affiliation(s)
- B W Kiernan
- Wellcome/CRC Institute of Developmental Biology and Cancer, Cambridge, UK
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Henderson JM, Annett LE, Ryan LJ, Chiang W, Hidaka S, Torres EM, Dunnett SB. Subthalamic nucleus lesions induce deficits as well as benefits in the hemiparkinsonian rat. Eur J Neurosci 1999; 11:2749-57. [PMID: 10457171 DOI: 10.1046/j.1460-9568.1999.00692.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Lesions of the subthalamic nucleus can restore some imbalances in motor output of the basal ganglia induced by nigrostriatal dopamine depletion, and have been proposed as a potential therapy for Parkinson's disease. Although there is substantial supporting evidence from experimental studies in both rats and primates, there is less information on the effects of subthalamic lesions alone. In order to characterize potential side effects, the present study evaluates the behavioural effects of unilateral excitotoxic lesions of the subthalamic nucleus in rats that have previously received either unilateral saline or 6-hydroxydopamine injections into the nigrostriatal bundle on the same side. The 6-hydroxydopamine lesions induced ipsilateral orientation asymmetries in head position and body axis bias, rotational asymmetries following injections of direct or indirect dopamine agonists, neglect of contralateral stimuli, and a reduction in the numbers of pellets retrieved with the contralateral paw in a skilled reaching task. Subsequent excitotoxic lesions of the subthalamic nucleus reduced (but did not abolish) rotational asymmetries, had no effects on the measures of neglect and skilled paw-reaching, and produced contralateral orientation biases in head turning and body axis curling. Rats that received subthalamic lesions alone exhibited de novo impairments comprising contralateral biases in the orientation tests. These results support a neuromodulatory role of the subthalamic nucleus in regulating motor outputs of the basal ganglia, and caution that there may be distinct side effects of the lesion by itself. Whereas some impairments attributable to dopamine depletion may be alleviated by subthalamic manipulations, other symptoms are not, or may even be aggravated.
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Affiliation(s)
- J M Henderson
- MRC Cmbrdige Centre for Brain Repair and Department of Experimental Psychology, University of Cambridge, UK
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Dunnett SB, Carter RJ, Watts C, Torres EM, Mahal A, Mangiarini L, Bates G, Morton AJ. Striatal transplantation in a transgenic mouse model of Huntington's disease. Exp Neurol 1998; 154:31-40. [PMID: 9875265 DOI: 10.1006/exnr.1998.6926] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Striatal grafts have been proposed as a potential strategy for striatal repair in Huntington's disease, but it is unknown whether the diseased brain will compromise graft survival. A transgenic mouse line has recently been described in which hemizygotes with an expanded CAG repeat in exon 1 of the HD gene exhibit a progressive neurological phenotype similar to the motor symptoms of Huntington's disease. We have therefore evaluated the effects of the transgenic brain environment on the survival, differentiation, and function of intrastriatal striatal grafts and undertaken a preliminary analysis of the effects of the grafts on the development of neurological deficits in the host mice. Hemizygote transgenic and wild-type littermate female mice received striatal grafts at 10 weeks of age and were allowed to survive 6 weeks. Normal healthy grafts were seen to survive and differentiate within the striatum of transgenic mice in a manner comparable to that seen in control mice. The transgenic mice exhibited a progressive decline in body weight from 9 weeks of age and a progressive hypoactivity in an open field test of general locomotor behavior. Although striatal grafts exerted a statistically significant influence on several indices of this impairment, all behavioral effects were small and did not exert any clinically relevant effect on the profound neurological deficiency of the transgenic mice.
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Affiliation(s)
- S B Dunnett
- MRC Cambridge Centre for Brain Repair, University of Cambridge, London, United Kingdom
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Abstract
Only a small proportion of dopamine neurons in nigral grafts typically survive transplantation into the adult striatum. Since many anaesthetics reduce blood flow and disturb a variety of brain metabolites, surgical anaesthesia may be one of the factors that compromise graft survival. Conversely, the lowered core body temperature induced by some anaesthetics might promote the survival of grafted cells by slowing their metabolism. In an initial screen, the widely-used surgical anaesthetic, equithesin, was found to reduce core temperature, mean arterial blood pressure, and to increase the partial pressure of oxygen in arterial blood without producing any significant alteration in arterial pH or the partial pressure of carbon dioxide. In the main experiment, rats with unilateral 6-hydroxydopamine lesions of the nigrostriatal bundle received dopamine-rich embryonic nigral grafts injected into the deafferented neostriatum via previously implanted guide cannulae, which allowed comparison to be made of graft survival after transplantation into awake and in re-anaesthetised animals. There were no significant differences between groups in either the functional effects of the grafts to compensate amphetamine-induced rotation, or in the survival and growth of the grafts as measured in post mortem histology. We therefore conclude that anaesthesia per se is not a major contributory factor in the relatively poor survival of dopamine neurons following transplantation into the rat striatum.
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Affiliation(s)
- S B Dunnett
- MRC Cambridge Centre for Brain Repair, and the Department of Experimental Psychology, University of Cambridge, UK.
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Fanghänel G, Silva U, Sanchez-Reyes L, Sisson D, Sotres D, Torres EM. Effects of metformin on fibrinogen levels in obese patients with type 2 diabetes. Rev Invest Clin 1998; 50:389-94. [PMID: 9949668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
OBJECTIVE To determine fibrinogen levels in obese patients with type 2 diabetes and assess its changes with the use of metformin. METHODS 60 obese patients (BMI > 27) with type 2 diabetes were studied in an open, two phase, prospective, randomized and comparative study. The pre-treatment phase was a period of four weeks of a controlled diet. In the treatment phase they were divided in two subgroups of 30. One received metformin as a daily single tablet of 850 mg and increasing the dosage to two or three tablets depending on their metabolic control. The second subgroup received 24 units of DNA-recombinant insulin subcutaneously (two thirds of dose before breakfast, and the remaining third before dinner). The insulin dosage was adjusted according to the metabolic response. A control group was formed by 60 non diabetic obese patients with only the controlled diet. RESULTS The mean values of plasma glucose, fibrinogen levels and body mass index did not change in the pretreatment phase in controls and diabetics. These parameters decreased significantly in the metformin subgroup in the treatment phase (p < 0.001). Only glucose decreased in the insulin subgroup. There were no changes in the controls. CONCLUSIONS In addition to improving metabolic control, metformin showed to be a good therapeutic alternative in modifying fibrinogen levels in type 2 diabetic patients.
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Affiliation(s)
- G Fanghänel
- Department of Endocrinology, General Hospital of Mexico, Mexico City, Mexico.
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Kendall AL, Rayment FD, Torres EM, Baker HF, Ridley RM, Dunnett SB. Functional integration of striatal allografts in a primate model of Huntington's disease. Nat Med 1998; 4:727-9. [PMID: 9623985 DOI: 10.1038/nm0698-727] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Huntington's disease is an autosomal dominant, inherited disorder that results in progressive degeneration of the basal ganglia (especially the neostriatal caudate nucleus and putamen) and other forebrain structures and is associated with a clinical profile of movement, cognitive and psychiatric impairments for which there is at present no effective therapy. Neuropathological, neurochemical and behavioral features of the disease can all be reproduced in experimental animals by local injection of excitotoxic or metabolic toxins into the neostriatum. All these features of the disease can be alleviated, at least in rats, by transplantation of embryonic striatal tissue into the degenerated striatum, which was the basis for commencing the first clinical trials of striatal transplantation in Huntington's patients. However, although rat striatal xenografts may temporarily reduce apomorphine-induced dyskinesias in monkeys, there has been no demonstration that allograft techniques that work well in rats translate effectively to the much larger differentiated striatum of primates. Here we demonstrate good survival, differentiation and integration of striatal allografts in the primate neostriatum, and recovery in a test of skilled motor performance. Long-term graft survival in primates indicates probable success for clinical transplants in Huntington's disease; in addition, our data suggest that graft placement has a direct influence on the pattern and extent of functional recovery.
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Affiliation(s)
- A L Kendall
- Department of Experimental Psychology and the MRC Cambridge Centre for Brain Repair, University of Cambridge, UK.
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Abstract
A modified grip strength meter was designed to enable the separate measurement of lateralised grip strength in the two forelimbs of rats, in order to allow assessment of deficits in animals with unilateral lesions and grafts within the basal ganglia. Unilateral 6-hydroxydopamine lesions of the dopaminergic nigrostriatal bundle induced a significant asymmetry, marked by an increased grip strength on the side contralateral to the lesion. Lesioned animals with additional implants of embryonic nigral cell suspensions into the dopamine-denervated neostriatum showed a reduced (but not significant) deficit and did not differ from control performance. The lateralised nature of the deficit excludes explanation based on global activational changes; rather the unilateral deficit may provide a simple test of unilateral 'rigidity' in a widely used rodent model of Parkinson's disease.
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Affiliation(s)
- S B Dunnett
- MRC Cambridge Centre for Brain Repair and Department of Experimental Psychology, University of Cambridge, UK.
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