davunetide and Hypoxia

This review focuses on the therapeutic effects and mechanisms of action of NAP (davunetide), an eight amino acid snippet derived from activity-dependent neuroprotective protein (ADNP) which was discovered in the laboratory of Prof. Illana Gozes. The effects of NAP and its related peptides in models of neurodegenerative diseases and other neurological disorders will be described here in details. Possible mechanisms of NAP actions include anti-inflammatory effect, antioxidant activity, inhibition of protein aggregation and interaction with microtubules. In line with the fact that all of these features are characteristic to most neurological/neurodegenerative disorders, NAP was found to have beneficial effects on the behavioral manifestations associated with these disorders.

Topics: Animals; Humans; Hypoxia; Learning; Neurodegenerative Diseases; Oligopeptides; Retina

NAP (davunetide) is a clinical octapeptide and reportedly possesses neuroprotective, neurotrophic and cognitive protective properties. The information for NAP-mediated neuroproteome changes and associated signaling pathways during hypoxia will help in drug development programmes across the world. In the present study, we have evaluated the antioxidant activities of NAP in rat hippocampus exposed to hypobaric hypoxia (25,000 ft, 282 mm Hg) for 3, 6 and 12 h respectively. Using 2D-gel electrophoresis (2D-GE) with matrix-assisted laser desorption ionization time of flight (MALDI-TOF/TOF) mass spectrometry, we have identified altered expression of 80 proteins in NAP-supplemented hippocampus after hypoxia. Pathway analysis revealed that NAP supplementation significantly regulated oxidative stress response, oxidoreductase activity and cellular response to stress pathways during hypoxia. Additionally, NAP supplementation also regulated energy production pathways along with AMP-activated protein kinase (AMPK) signaling and signaling by Rho family GTPases pathways. We observed higher expression of antioxidant Sod1, Eno1, Prdx2 and Prdx5 proteins that were subsequently validated by Western blotting. A higher level of Prdx2 was also observed by immunohistochemistry in NAP-supplemented hippocampus during hypoxia. In corroboration, we are able to detect significant lower level of protein carbonyls in NAP-supplemented hypoxic hippocampus suggesting amelioration of oxidant molecules by NAP supplementation. These results emphasize the antioxidant and signaling properties of NAP in rodent hippocampus during hypobaric hypoxia.

Topics: Adenylate Kinase; Animals; Antioxidants; Hippocampus; Hypoxia; Male; Oligopeptides; Oxidative Stress; Peroxiredoxins; Phosphopyruvate Hydratase; Proteome; Rats; Rats, Sprague-Dawley; rho GTP-Binding Proteins; Superoxide Dismutase; Superoxide Dismutase-1

Hypobaric hypoxia is a socio-economic problem affecting cognitive, memory and behavior functions. Severe oxidative stress caused by hypobaric hypoxia adversely affects brain areas like cortex, hippocampus, basal ganglia, and cerebellum. In the present study, we have investigated the antioxidant and memory protection efficacy of the synthetic NAP peptide (NAPVSIPQ) during long-term chronic hypobaric hypoxia (7, 14, 21 and 28 days, 25,000ft) in rats. Intranasal supplementation of NAP peptide (2μg/Kg body weight) improved antioxidant status of brain evaluated by biochemical assays for free radical estimation, lipid peroxidation, GSH and GSSG level. Analysis of expression levels of SOD revealed that NAP significantly activated antioxidant genes as compared to hypoxia exposed rats. We have also observed a significant increased expression of Nrf2, the master regulator of antioxidant defense system and its downstream targets such as HO-1, GST and SOD1 by NAP supplementation, suggesting activation of Nrf2-mediated antioxidant defense response. In corroboration, our results also demonstrate that NAP supplementation improved the memory function assessed with radial arm maze. These cumulative results suggest the therapeutic potential of NAP peptide for ameliorating hypobaric hypoxia-induced oxidative stress.

Topics: Administration, Intranasal; Altitude Sickness; Animals; Brain; Free Radicals; Glutathione; Glutathione Disulfide; Heme Oxygenase-1; Hypoxia; Lipid Peroxidation; Male; Malondialdehyde; Maze Learning; Memory; Neuroprotective Agents; NF-E2-Related Factor 2; Oligopeptides; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Superoxide Dismutase; Superoxide Dismutase-1

Perinatal hypoxic injury is associated with significant neonatal morbidity and long-term neurodevelopmental complications. NAP, a peptide derived from ADNP (activity-dependent neuroprotective protein), has previously shown neuroprotective abilities in various adult animal models. To evaluate its neuroprotective role in neonatal hypoxic-ischemic injury, we evaluated the neurodevelopmental outcome in apolipoprotein E (ApoE)-deficient (knockout) mice (a breed prone to brain damage during hypoxic insult) exposed to postnatal global hypoxic damage with and without treatment with NAP. ApoE-deficient (n = 80) and control (C57B6) mice pups (n = 81) were exposed to postnatal global hypoxia (35 min of 8% O(2) within 24 h of birth) or room air with or without subsequent subcutaneous NAP treatment during postnatal days 1 to 14. Pups were then evaluated for neonatal motor reflex attainment, spatial learning ability in the Morris water maze, and locomotor open-field activity. The C57B6 and ApoE-deficient anoxic groups showed significantly slower achievement of neonatal reflexes, diminished locomotor activity, and diminished spatial learning ability compared with their control groups. This was more pronounced in the anoxic ApoE-deficient pups. NAP treatment had a pronounced effect on neurodevelopmental outcome in both breeds, particularly in the ApoE-deficient mice. ApoE-deficient and control mouse pups exposed to postnatal hypoxia and treated with NAP showed improvement in neurodevelopmental outcome compared with nontreated mice pups. ApoE-deficient mice show a greater susceptibility to hypoxic damage and better response to NAP treatment.

Topics: Animals; Animals, Newborn; Apolipoproteins E; Brain; Hypoxia; Maze Learning; Memory, Short-Term; Mice; Mice, Inbred C57BL; Motor Activity; Neuroprotective Agents; Oligopeptides; Reflex; Weight Gain