Prevention of learning deficit in a Down syndrome model.
OBJECTIVE
To evaluate whether peptides given to adult mice with Down syndrome prevent learning deficits, and to delineate the mechanisms behind the protective effect.


METHODS
Ts65Dn mice were treated for 9 days with peptides D-NAPVSIPQ (NAP)+D-SALLRSIPA (SAL) or placebo, and wild-type animals were treated with placebo. Beginning on treatment day 4, the mice were tested for learning using the Morris watermaze. Probe tests for long-term memory were performed on treatment day 9 and 10 days after treatment stopped. Open-field testing was performed before and after the treatment. Calibrator-normalized relative real-time polymerase chain reaction (PCR) with glyceraldehyde-3-phosphate dehydrogenase (GAPD) standardization was performed on the whole brain and hippocampus for activity-dependent neuroprotective protein, vasoactive intestinal peptide (VIP), glial fibrillary acidic protein (GFAP), NR2B, NR2A, and γ-aminobutyric acid type A (GABAA)-α5. Statistics included analysis of variance and the Fisher protected least significant difference, with P<.05 significant.


RESULTS
The Ts65Dn plus placebo animals did not learn over the 5-day period compared with the controls (P<.001). The Ts65Dn +(D-NAP+D-SAL) learned significantly better than the Ts65Dn plus placebo (P<.05), and they retained learning similar to controls on treatment day 9, but not after 10 days of no treatment. Treatment with D-NAP+D-SAL prevented the Ts65Dn hyperactivity. Adult administration of D-NAP+D-SAL prevented changes in activity-dependent neuroprotective protein, intestinal peptide, and NR2B with levels similar to controls (all P<.05).


CONCLUSIONS
Adult treatment with D-NAP+D-SAL prevented learning deficit in Ts65Dn, a model of Down syndrome. Possible mechanisms of action include reversal of vasoactive intestinal peptide and activity-dependent neuroprotective protein dysregulation, as well as increasing expression of NR2B, thus facilitating learning.
From the Unit on Perinatal and Developmental Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institute of Health, Bethesda, Maryland; the Department of Obstetrics/Gynecology, George Washington University, Washington, District of Columbia; the Division of Maternal Fetal Medicine, Columbia University Medical Center, New York, New York, and the Department of Obstetrics/Gynecology University of Connecticut Health Center, Connecticut.
Maddalena
M
Incerti
Laura
L
Toso
Joy
J
Vink
Robin
R
Roberson
Christopher
C
Nold
Daniel
D
Abebe
Catherine Y
CY
Spong
D000818:Animals; D004195:Disease Models, Animal; D004314:Down Syndrome / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D018398:Homeodomain Proteins / Q000378:metabolism; D007859:Learning Disabilities / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009419:Nerve Tissue Proteins / Q000378:metabolism / Q000627:therapeutic use*; D009842:Oligopeptides / Q000627:therapeutic use*; D010446:Peptide Fragments / Q000627:therapeutic use*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism
C117632:Adnp protein, mouse; D005904:Glial Fibrillary Acidic Protein; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D009842:Oligopeptides; D010446:Peptide Fragments; C526732:SALLRSIPA; D014660:Vasoactive Intestinal Peptide; C425904:davunetide
Epstein CJ. Down syndrome (trisomy 21). In: Shriver CR, Beaudet AL, Sly WS, Valle D, editors. The metabolic basis of inherited disease. New York (NY): McGraw-Hill; 1989:291–326.
Coyle JT, Oster-Granite ML, Gearhart JD. The neurobiologic consequences of Down syndrome. Brain Res Bull 1986;16:773–87.
Vicari S. Motor development and neuropsychological patterns in persons with Down syndrome. Behav Genet 2006;36:355–64.
Hill JM, Ades AM, McCune SK, Sahir N, Moody EM, Abebe DT, et al. Vasoactive intestinal peptide in the brain of a mouse model for Down syndrome. Exp Neurol 2003;183:56–65.
Nelson PG, Kuddo T, Song EY, Dambrosia JM, Kohler S, Satyanarayana G, et al. Selected neurotrophins, neuropeptides, and cytokines: developmental trajectory and concentrations in neonatal blood of children with autism or Down syndrome. Int J Dev Neurosci 2006;24:73–80.
Brenneman DE, Phillips TM, Festoff BW, Gozes I. Identity of neurotrophic molecules released from astroglia by vasoactive intestinal peptide. Ann N Y Acad Sci 1997;814:167–73.
Brenneman DE, Hauser J, Neale E, Rubinraut S, Fridkin M, Davidson A, et al. Activity-dependent neurotrophic factor: structure-activity relationships of femtomolar-acting peptides. J Pharmacol Exp Ther 1998;285:619–27.
Bassan M, Zamostiano R, Davidson A, Pinhasov A, Giladi E, Perl O, et al. Complete sequence of a novel protein containing a femtomolar-activity-dependent neuroprotective peptide. J Neurochem 1999;72:1283–93.
Gozes I, Zamostiano R, Pinhasov A, Bassan M, Giladi E, Steingart RA, et al. A novel VIP responsive gene: activity dependent neuroprotective protein. Ann N Y Acad Sci 2000;921:115–8.
Busciglio J, Pelsman A, Helguera P, Ashur-Fabian O, Pinhasov A, Brenneman DE, et al. NAP and ADNF-9 protect normal and Down's syndrome cortical neurons from oxidative damage and apoptosis. Curr Pharm Des 2007;13:1091–8.
Toso L, Cameroni I, Roberson R, Abebe D, Bissell S, Spong CY. Prevention of developmental delays in a Down syndrome model. Obstet Gynecol 2008;112:1242–51.
Epstein CJ. 2001 William Allan Award Address. From Down syndrome to the “human” in “human genetics.” Am J Hum Genet 2002;70:300–13.
Hyde LA, Frisone DF, Crnic LS. Ts65Dn mice, a model for Down syndrome, have deficits in context discrimination learning suggesting impaired hippocampal function. Behav Brain Res 2001;118:53–60.
Kleschevnikov AM, Belichenko PV, Villar AJ, Epstein CJ, Malenka RC, Mobley WC. Hippocampal long-term potentiation suppressed by increased inhibition in the Ts65Dn mouse, a genetic model of Down syndrome. J Neurosci 2004;24:8153–60.
Freund TF, Buzsáki G. Interneurons of the hippocampus. Hippocampus 1996;6:347–470.
Pérez-Otaňo I, Ehlers D. Learning form NMDA receptor trafficking: clues to the development and maturation of glutamatergic synapses. Neurosignals 2004;3:175–89.
Davisson MT, Schmidt C, Akeson EC. Segmental trisomy of murine chromosome 16: a new model system for studying Down syndrome. Prog Clin Biol Res 1990;360:263–80.
Reeves RH, Irving NG, Moran TH, Wohn A, Kitt C, Sisodia SS, et al. A mouse model for Down Syndrome exhibits learning and behaviour deficits. Nat Genet 1995;11:177–84.
Holtzman DM, Santucci D, Kilbridge J, Chua-Couzens J, Fontana DJ, Daniels SE, et al. Developmental abnormalities and age-related neurodegeneration in a mouse model of Down syndrome. Proc Natl Acad Sci U S A 1996;93:13333–8.
Demas GE, Nelson RJ, Krueger BK, Yarowsky PJ. Spatial memory deficits in segmental trisomic Ts65Dn mice. Behav Brain Res 1996;82:85–92.
Demas GE, Nelson RJ, Krueger BK, Yarowsky PJ. Impaired spatial working and reference memory in segmental trisomy (Ts65Dn) mice. Behav Brain Res 1998;90:199–201.
Escorihuela RM, Vallina IF, Martinez-Cué C, Baamonde C, Dierssen M, Tobeña A, et al. Impaired short- and long-term memory in Ts65Dn mice, a model for Down syndrome. Neurosci Lett 1998;247:171–4.
Sago H, Carlson EJ, Smith DJ, Rubin EM, Crnic LS, Huang TT, et al. Genetic dissection of region associated with behavioral abnormalities in mouse models for Down syndrome. Pediatr Res 2000;48:606–13.
Brenneman DE, Spong CY, Hauser JM, Abebe D, Pinhasov A, Golian T, et al. Protective peptides that are orally active and mechanistically nonchiral. J Pharmacol Exp Ther 2004;309:1190–7.
Morris RG, Garrud P, Rawlins JN, O'Keefe J. Place navigation in rats with hippocampal lesions. Nature 1982;297:681–3.
Vink J, Auth J, Abebe DT, Brenneman DE, Spong CY. Novel peptides prevent alcohol-induced spatial learning deficits and proinflammatory cytokine release in a mouse model of fetal alcohol syndrome. Am J Obstet Gynecol 2005;193(3 pt 1):825–9.
Toso L, Endres M, Vink J, Abebe DT, Brenneman DE, Spong CY. Learning enhancement with neuropeptides. Am J Obstet Gynecol 2006;194:1153–8.
Nelson PG, McCune SK, Ades AM, Nelson KB. Glial-neurotrophic mechanisms in Down syndrome. J Neural Transm Suppl 2001;(61):85–94.
Collison N, Kuenzi FM, Jarolimek W, Maubach KA, Cothliff R, Sur C, et al. Enhanced learning and memory and altered GABAergic synaptic transmission in mice lacking the alpha 5 subunit of the GABAA receptor. J Neurosci 2002;22:5572–80.
Sicar R, Basak A. Adolescent gamma-hydroxybutyric acid exposure decreases cortical N-methyl-D-aspartate receptor and impairs spatial learning. Pharmacol Biochem Behav 2004;79:701–8.
Toso L, Poggi SH, Roberson R, Woodard J, Park J, Abebe D, et al. Prevention of alcohol-induced learning deficits in a fetal alcohol syndrome mediated through NMDA and GABA receptors. Am J Obstet Gynecol 2006;194:681–6.
Brenneman DE, Gozes I. A femtomolar-acting neuroprotective peptide. J Clin Invest 1996;97:2299–307.
Roizen NJ, Patterson D. Down's syndrome. Lancet 2003;361:1281–9.
Fernandez F, Morishita W, Zuniga E, Nguyen J, Blank M, Malenka RC, et al. Pharmacotherapy for cognitive impairment in a mouse model of Down syndrome. Nat Neurosci. 2007;10:411–3.