davunetide and Down-Syndrome

Down syndrome is the most common genetic cause of mental retardation. Active fragments of neurotrophic factors release by astrocyte under the stimulation of vasoactive intestinal peptide, NAPVSIPQ (NAP) and SALLRSIPA (SAL) respectively, have shown therapeutic potential for developmental delay and learning deficits. Previous work demonstrated that NAP+SAL prevent developmental delay and glial deficit in Ts65Dn that is a well-characterized mouse model for Down syndrome. The objective of this study is to evaluate if prenatal treatment with these peptides prevents the learning deficit in the Ts65Dn mice. Pregnant Ts65Dn female and control pregnant females were randomly treated (intraperitoneal injection) on pregnancy days 8 through 12 with saline (placebo) or peptides (NAP 20 µg +SAL 20 µg) daily. Learning was assessed in the offspring (8-10 months) using the Morris Watermaze, which measures the latency to find the hidden platform (decrease in latency denotes learning). The investigators were blinded to the prenatal treatment and genotype. Pups were genotyped as trisomic (Down syndrome) or euploid (control) after completion of all tests.. two-way ANOVA followed by Neuman-Keuls test for multiple comparisons, P<0.05 was used to denote statistical significance. Trisomic mice who prenatally received placebo (Down syndrome-placebo; n = 11) did not demonstrate learning over the five day period. DS mice that were prenatally exposed to peptides (Down syndrome-peptides; n = 10) learned significantly better than Down syndrome-placebo (p<0.01), and similar to control-placebo (n = 33) and control-peptide (n = 30). In conclusion prenatal treatment with the neuroprotective peptides (NAP+SAL) prevented learning deficits in a Down syndrome model. These findings highlight a possibility for the prevention of sequelae in Down syndrome and suggest a potential pregnancy intervention that may improve outcome.

Topics: Animals; Disease Models, Animal; Down Syndrome; Female; Learning; Mice; Nerve Tissue Proteins; Oligopeptides; Peptide Fragments; Pregnancy

To evaluate whether peptides given to adult mice with Down syndrome prevent learning deficits, and to delineate the mechanisms behind the protective effect.. 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.. 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).. 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.

Topics: Animals; Disease Models, Animal; Down Syndrome; Female; Glial Fibrillary Acidic Protein; Homeodomain Proteins; Learning Disabilities; Male; Mice; Mice, Inbred C57BL; Nerve Tissue Proteins; Oligopeptides; Peptide Fragments; Vasoactive Intestinal Peptide

Down syndrome (DS) affects 1/800 infants. Prenatal NAPVSIPQ (NAP) and SALLRSIPA (SAL) (NAP+SAL) prevent developmental delay in Ts65Dn mice, a mouse model of DS. We investigated whether this finding involves N-methyl-D-aspartic acid and gamma-aminobutyric acid (GABA) receptor subunits.. Pregnant Ts65Dn mice were treated with placebo or NAP+SAL on gestational days 8-12. After developmental delay prevention was shown, 4 trisomic (Ts), 4 control, and 3 Ts+NAP+SAL adult offspring brains (from 3 litters) were collected. Calibrator-normalized real-time polymerase chain reaction was performed using primers for N-methyl-D-aspartic acid subunits NR2A and NR2B, and for GABA subunits GABA(A)alpha5 and GABA(A)beta3 with glyceraldehyde-3-phosphate dehydrogenase standardization. Statistics included analysis of variance and Fisher PLSD with P < .05 as significant.. NR2A, NR2B, and GABA(A)beta3 levels were decreased in Ts vs control (all P < .05). Prenatal NAP+SAL increased NR2A, NR2B, and GABA(A)beta3 to levels similar to control (all P < .05). A significant difference in GABA(A)alpha5 levels was not found.. Prenatal NAP+SAL increases NR2A, NR2B, and GABA(A)beta3 expression in adult DS mice to levels similar to controls. This may explain how NAP+SAL improve developmental milestone achievement.

Topics: Animals; Animals, Newborn; Brain Diseases; Central Nervous System; Disease Models, Animal; Down Syndrome; Female; Intellectual Disability; Mice; Mice, Mutant Strains; Nerve Tissue Proteins; Oligopeptides; Peptide Fragments; Pregnancy; Prenatal Exposure Delayed Effects; Receptors, GABA-A; Receptors, N-Methyl-D-Aspartate

To estimate whether prenatal treatment with neuroprotective peptides prevents the developmental delay and the glial deficit in the Ts65Dn mouse model for Down syndrome and to explore the peptides' effects on achievement of normal development.. Pregnant Ts65Dn females were randomly assigned to NAPVSIPQ+SALLRSIPA or control and were treated by investigators blinded to treatment and genotype on gestational days 8-12. Offspring were tested from postnatal day 5 to 21 for motor and sensory milestones with standardized tests by operators blinded to the pup's treatment and genotype. The pup's genotype was determined after completion of all tests. Activity-dependent neurotrophic factor, glial fibrillary acidic protein, and vasoactive intestinal peptide expression were determined using real-time polymerase chain reaction.. Trisomic mice achieved milestones with a significant delay in four of five motor and sensory milestones. Trisomic mice that were prenatally exposed to NAPVSIPQ+SALLRSIPA achieved developmental milestones at the same time as the controls in three of four motor and one of four sensory milestones (P<.01). Euploid pups prenatally treated with NAPVSIPQ+SALLRSIPA achieved developmental milestones significantly earlier than the euploid pups prenatally treated with placebo. Activity-dependent neurotrophic factor expression was significantly downregulated in the Ts65Dn brains compared with the controls, prenatal treatment with NAPVSIPQ+ SALLRSIPA prevented the activity-dependent neurotrophic factor decrease in the Ts65Dn brains, and the expression was not different from the controls. The glial marker glial fibrillary acidic protein demonstrated the known glial deficit in the Ts65Dn mice, and treatment with NAPVSIPQ+ SALLRSIPA prevented its downregulation. Lastly, vasoactive intestinal peptide levels were increased in the trisomic brains, whereas treatment with NAPVSIPQ+SALLRSIPA did not prevent its upregulation.. Prenatal treatment with NAPVSIPQ and SALLRSIPA prevented developmental delay and the glial deficit in Down syndrome. These findings highlight a possibility for the prevention of developmental sequelae in Down syndrome and suggest a potential intervention during pregnancy that may improve the outcome.

Topics: Animals; Animals, Newborn; Developmental Disabilities; Disease Models, Animal; Down Syndrome; Female; Humans; Infant; Infusions, Parenteral; Mice; Nerve Tissue Proteins; Neuroglia; Neuroprotective Agents; Oligopeptides; Peptide Fragments; Pregnancy; Prenatal Care

NAP (Asn-Ala-Pro-Val-Ser-Ile-Pro-Gln, single letter code: NAPVSIPQ) and ADNF-9 (activity-dependent neurotrophic factor-9; Ser-Ala-Leu-Leu-Arg-Ser-Ile-Pro-Ala; single letter code: SALLRSIPA) are peptides derived from naturally occurring glial proteins that have shown neuroprotection in rodent model systems. Here, the neuroprotective activity of ADNF-9 and NAP was tested in two human models of neuronal degeneration in culture mediated by oxidative stress: normal human cortical neurons treated with H2O2 and Down's syndrome (DS) cortical neurons. Incubation of normal cortical neurons with 50 microM H2O2 for 1 hour resulted in morphological and structural changes consistent with neuronal degeneration and loss of viability of more than 60% of the neurons present in the culture. Addition of ADNF-9 or NAP at femtomolar concentrations resulted in significant increases in survival of normal neurons treated with H2O2. Femtomolar concentrations of ADNF-9 or NAP exhibited a similar neuroprotective efficacy, comparable to the antioxidant N-tert-butyl-2-sulpho-phenylnitrone at 100 microM (s-PBN). Treatment of DS cortical neurons with ADNF-9 or NAP resulted in a significant increase in neuronal survival as well as reduction of degenerative morphological changes. The results suggest that ADNF-9 and NAP possess potent neuroprotective properties against oxidative damage in human neurons that may be useful to preserve neuronal function and prevent neuronal death associated with chronic neurodegenerative disorders.

Topics: Animals; Apoptosis; Cell Survival; Cells, Cultured; Cerebral Cortex; Down Syndrome; Fetus; Humans; Mice; Neurodegenerative Diseases; Neurons; Neuroprotective Agents; Oligopeptides; Oxidative Stress