davunetide and Alzheimer-Disease

Fifteen years ago we discovered activity-dependent neuroprotective protein (ADNP), and showed that it is essential for brain formation/function. Our protein interaction studies identified ADNP as a member of the chromatin remodeling complex, SWI/SNF also associated with alternative splicing of tau and prediction of tauopathy. Recently, we have identified cytoplasmic ADNP interactions with the autophagy regulating microtubule-associated protein 1 light chain 3 (LC3) and with microtubule end-binding (EB) proteins. The ADNP-EB-binding SIP domain is shared with the ADNP snippet drug candidate, NAPVSIPQ termed NAP (davunetide). Thus, we identified a precise target for ADNP/NAP (davunetide) neuroprotection toward improved drug development.

Topics: Alzheimer Disease; Animals; Autistic Disorder; Autophagy; Cytoskeleton; Drug Discovery; Gene Expression Regulation; Homeodomain Proteins; Humans; Nerve Tissue Proteins; Neuroprotection; Oligopeptides; Protein Interaction Maps; Schizophrenia

Alzheimer's disease (AD) is characterised by a progressive loss of cognitive functions. Histopathologically, AD is defined by the presence of extracellular amyloid plaques containing Aβ and intracellular neurofibrillary tangles composed of hyperphosphorylated tau proteins. According to the now well-accepted amyloid cascade hypothesis is the Aβ pathology the primary driving force of AD pathogenesis, which then induces changes in tau protein leading to a neurodegenerative cascade during the progression of disease. Since many earlier drug trials aiming at preventing Aβ pathology failed to demonstrate efficacy, tau and microtubules have come into focus as prominent downstream targets. The article aims to develop the current concept of the involvement of tau in the neurodegenerative triad of synaptic loss, cell death and dendritic simplification. The function of tau as a microtubule-associated protein and versatile interaction partner will then be introduced and the rationale and progress of current tau-directed therapy will be discussed in the biological context.

Topics: Alzheimer Disease; Epothilones; Humans; Immunization, Passive; Methylene Blue; Molecular Targeted Therapy; Oligopeptides; Protein Aggregation, Pathological; tau Proteins

Alzheimer's disease (AD) is a multifactorial syndrome involving a complex array of different, while related, factors in its progression. Accordingly, novel approaches that can simultaneously modulate several disease-related targets hold great promise for the effective treatment of AD. This review describes the development of novel hybrid molecules with multimodal activity, including: i) M30, the brain permeable selective monoamine oxidase (MAO)-A and -B inhibitor with chelating and neuroprotective activity; ii) HLA20, a brain permeable metal chelator with neuroprotective activity; iii) HLA20A, an acetylcholinesterase (AChE) inhibitor with site-activated chelating and neuroprotective activity; iv) M30D, an AChE and MAO-A and -B inhibitor with site-activated chelating and neuroprotective activity; and v) analogs of the neuroprotective aminoacid peptide, NAPVSIPQ. HLA20A and M30D act as pro-chelators and can be activated to liberate their respective active chelators HLA20 and M30 through pseudo inhibition of AChE. We first discuss the knowledge and structure-based strategy for the rational design of these novel compounds. Then, we review our recent studies on these drug candidates, regarding their wide range in vitro and in vivo activities, with emphasis on antioxidant-chelating potency and AchE and MAO-A and -B inhibitory activity, as well as neuroprotective/neurorescue effects. Finally, we discuss the diverse molecular mechanisms of action of these compounds with relevance to AD, including modulation of amyloid-β and amyloid-β protein precursor expression/processing; induction of cell cycle arrest; inhibition of neuronal death markers; and upregulation of neurotrophic factors, as well as activation of protein kinase signaling pathways.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Animals; Cell Cycle Checkpoints; Chelating Agents; Cholinesterase Inhibitors; Humans; Hydroxyquinolines; Indans; Monoamine Oxidase Inhibitors; Neuroprotective Agents; Oligopeptides; Piperazines

Activity-dependent neuroprotective protein (ADNP) is essential for brain formation. Peptide activity scanning identified NAP (NAPVSIPQ) as a small active fragment of ADNP that provides neuroprotection at very low concentrations. In cell culture, NAP has demonstrated protection against toxicity associated with the beta-amyloid peptide, N-methyl-D-aspartate, electrical blockade, the envelope protein of the AIDS virus, dopamine, H2O2, nutrient starvation and zinc overload. NAP has also provided neuroprotection in animal models of apolipoprotein E deficiency, cholinergic toxicity, closed head injury, stroke, middle aged anxiety and cognitive dysfunction. NAP binds to tubulin and facilitates microtubule assembly leading to enhanced cellular survival that is associated with fundamental cytoskeletal elements. A liquid-chromatography, mass spectrometry assay demonstrated that NAP reaches the brain after either intravenous or intranasal administration. In a battery of toxicological tests including repeated dose toxicity in rats and dogs, cardiopulmonary tests in dogs, and functional behavioral assays in rats, no adverse side effects were observed with NAP concentrations that were approximately 500-fold higher than the biologically active dose. A Phase Ia clinical trial in the US assessed the tolerability and pharmacokinetics of intranasal administration of NAP in sequential ascending doses. The results supported the safety and tolerability of a single dose of NAP administered at up to 15 mg intranasally. Furthermore, dosing was recently completed for a second Phase I clinical trial in healthy adults and elderly volunteers with an intravenous formulation of NAP. NAP is poised for further clinical development targeting several indications, including Alzheimer's disease.

Topics: Alzheimer Disease; Animals; Behavior, Animal; Disease Models, Animal; Dogs; Drug Interactions; Humans; Neuroprotective Agents; Oligopeptides; Rats

NAP (NAPVSIPQ) is a small peptide derived from the activity-dependent neuroprotective protein (ADNP), which provides neuroprotection against amyloid-β peptide toxicity associated with Alzheimer disease. Several metal ions are able to promote the formation of amyloid-β peptide oligomers and protofibrils in human brain tissue. Although the relationship between metal ions and amyloid-β peptide peptides is extensively investigated, that with the NAP peptide is less understood. Nevertheless, our previous research revealed unexpected iron binding to NAP peptide and its analogs. However, a link between aluminum ions, Alzheimer disease and amyloid-β peptide or NAP peptides still remains controversial. Therefore, we have investigated the possible binding of aluminum ions to NAP peptide and its four analogs. Indeed, MALDI-ToF mass spectrometry (MS), including MS/MS study, and Fourier transform infrared (FT-IR) spectroscopy revealed an unexpected pattern of aluminum ion binding to both NAP peptide and its analogs. Our results have been discussed with respect to NAP protection against Alzheimer disease-related neurotoxicity.

Topics: Aluminum; Alzheimer Disease; Humans; Oligopeptides; Protein Binding; Spectroscopy, Fourier Transform Infrared; Tandem Mass Spectrometry

The microtubule (MT) associated protein Tau is instrumental for the regulation of MT assembly and dynamic instability, orchestrating MT-dependent cellular processes. Aberration in Tau post-translational modifications ratio deviation of spliced Tau isoforms 3 or 4 MT binding repeats (3R/4R) have been implicated in neurodegenerative tauopathies. Activity-dependent neuroprotective protein (ADNP) is vital for brain formation and cognitive function. ADNP deficiency in mice causes pathological Tau hyperphosphorylation and aggregation, correlated with impaired cognitive functions. It has been previously shown that the ADNP-derived peptide NAP protects against ADNP deficiency, exhibiting neuroprotection, MT interaction and memory protection. NAP prevents MT degradation by recruitment of Tau and end-binding proteins to MTs and expression of these proteins is required for NAP activity. Clinically, NAP (davunetide, CP201) exhibited efficacy in prodromal Alzheimer's disease patients (Tau3R/4R tauopathy) but not in progressive supranuclear palsy (increased Tau4R tauopathy). Here, we examined the potential preferential interaction of NAP with 3R vs. 4R Tau, toward personalized treatment of tauopathies. Affinity-chromatography showed that NAP preferentially interacted with Tau3R protein from rat brain extracts and fluorescence recovery after photobleaching assay indicated that NAP induced increased recruitment of human Tau3R to MTs under zinc intoxication, in comparison to Tau4R. Furthermore, we showed that NAP interaction with tubulin (MTs) was inhibited by obstruction of Tau-binding sites on MTs, confirming the requirement of Tau-MT interaction for NAP activity. The preferential interaction of NAP with Tau3R may explain clinical efficacy in mixed vs. Tau4R pathologies, and suggest effectiveness in Tau3R neurodevelopmental disorders.

Topics: Alzheimer Disease; Animals; Brain; Cell Line, Tumor; Cell Survival; Cognition; Fluorescence Recovery After Photobleaching; Homeodomain Proteins; Humans; Mice; Microtubules; Oligopeptides; Paclitaxel; Phosphorylation; Protein Binding; Protein Domains; Protein Processing, Post-Translational; Rats; Rats, Sprague-Dawley; tau Proteins; Tauopathies; Tubulin; Zinc

Organotypic brain slice culture models provide an alternative to early stage in vivo studies as an integrated tissue system that can recapitulate key disease features, thereby providing an excellent platform for drug screening. We recently described a novel organotypic 3xTg-AD mouse brain slice culture model with key Alzheimer's disease-like changes. We now highlight the potential of this model for testing disease-modifying agents and show that results obtained following in vivo treatment are replicated in brain slice cultures from 3xTg-AD mice. Moreover, we describe novel effects of the amyloid-binding tetra (ethylene glycol) derivative of benzothiazole aniline, BTA-EG

Topics: Alzheimer Disease; Animals; Brain; Drug Evaluation, Preclinical; Glycogen Synthase Kinase 3; Humans; Lithium Chloride; Mice; Mice, Transgenic; Models, Biological; Oligopeptides; Organ Culture Techniques; Phosphorylation; Polyethylene Glycols; tau Proteins

Memory loss and cognition decline are the main clinical manifestations of Alzheimer's disease (AD). Amyloid β protein (Aβ) aggregated in the brain is one of the key pathological characteristics of AD and responsible for the deficits in learning and memory. It is reported that davunetide, an octapeptide derived from activity-dependent neuroprotective protein (ADNP), inhibited Aβ aggregation and Aβ-induced neurotoxicity. To further characterize the neuroprotective roles of davunetide and its possible mechanism, the present study investigated the effects of davunetide on Aβ1-42-induced impairments in spatial memory, synaptic plasticity and hippocampal AKT level. In Morris water maze (MWM) test, bilateral intrahippocampal injection of Aβ1-42 significantly increased escape latency and decreased target quadrant swimming time of rats, while three weeks of intranasal application of davunetide reversed the Aβ1-42-induced learning deficits and memory loss in a dose-dependent manner. In vivo field potentiation recording showed that Aβ1-42 suppressed long-term potentiation (LTP) of excitatory postsynaptic potential (fEPSP) in the hippocampal CA1 region of rats, while davunetide effectively blocked the suppression of LTP, without affecting paired-pulse facilitation (PPF). Western blotting experiments showed a significant decrease in the level of hippocampal p-AKT (Ser473), not total AKT, in Aβ1-42 only group, which was mostly antagonized by davunetide treatment. These findings demonstrate that davunetide, probably by enhancing PI3K/AKT pathway, plays an important positive role in attenuating Aβ1-42-induced impairments in spatial memory and synaptic plasticity, suggesting that davunetide could be an effective therapeutic candidate for the prevention and treatment of neurodegenerative disease such as AD.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Disease Models, Animal; Electric Stimulation; Hippocampus; Long-Term Potentiation; Male; Maze Learning; Memory Disorders; Oligopeptides; Oncogene Protein v-akt; Peptide Fragments; Rats; Rats, Sprague-Dawley; Reaction Time; Signal Transduction; Spatial Learning

A phage-displayed peptide TGN was used as a targeting motif to help the delivery of NAP-loaded nanoparticles across the blood-brain barrier (BBB), which sets an obstacle for brain delivery of NAP in vivo.. Intracerebroventricular injection of Aβ₁₋₄₀ into mice was used to construct in vivo model of Alzheimer's disease. The water maze task was performed to evaluate the effects of the NAP formulations on learning and memory deficits in mice. The neuroprotective effect was tested by detecting acetylcholinesterase (AChE) and choline acetyltransferase (ChAT) activity and conducting histological assays.. Intravenous administration of NAP-loaded TGN modified nanoparticles (TGN-NP/NAP) has shown better improvement in spatial learning than NAP solution and NAP-loaded nanoparticles in Morris water maze experiment. The crossing number of the mice with memory deficits recovered after treatment with TGN-NP/NAP in a dose dependent manner. Similar results were also observed in AChE and ChAT activity. No morphological damage and no detectable Aβ plaques were found in mice hippocampus and cortex treated with TGN-NP/NAP.. TGN modified nanoparticles could be a promising drug delivery system for peptide and protein drug such as NAP to enter the brain and play the therapeutic role.

Topics: Acetylcholinesterase; Alzheimer Disease; Animals; Blood-Brain Barrier; Brain; Choline O-Acetyltransferase; Drug Delivery Systems; Male; Memory Disorders; Mice; Nanoparticles; Neuroprotective Agents; Oligopeptides; Polyethylene Glycols; Polyglactin 910

NAPVSIPQ (NAP) is a small, active fragment of activity-dependent neuroprotective protein that has neuroprotective and memory enhancing properties at very low concentrations. Previous research demonstrated that 1-2 weeks of treatment provided memory enhancing effects in normal middle-aged and cholinergically lesioned rats. Improvement in cognitive performance was shown in 12-month-old C57Bl6/J mice after 10 days of oral treatment with D-NAP and D-SALLRSIPA. Additionally, NAP-related cognitive benefits on spatial memory were observed in a 3xTg Alzheimer mouse model after 6 months of chronic administration at a moderate stage of disease. In this study, the potential memory enhancing effect of NAP was investigated using the APP23 transgenic mouse model for Alzheimer's disease. Twelve-month-old male heterozygous APP23 mice and their wild-type control littermates were intraperitoneally injected with 0.3 microg NAP/g body weight or with saline vehicle for 22 consecutive days. Cognitive performance training in the Morris Water Maze (MWM) started on day 8 of treatment. The internal validity of our study was demonstrated by the fact that the APP23 mice performed significantly worse in the MWM than wild-type animals. Treatment with NAP, however, did not exert any significant effects on MWM performance. Although we failed to show significant memory enhancing effects in this study, NAP might be a promising peptide for disease-modifying therapy in neurodegenerative disease, but short-term effects are probably not to be expected. Also, most likely, treatment should start in an early stage, i.e. before full-blown pathology is eminent, and the necessary treatment period should enclose several months.

Topics: Alzheimer Disease; Animals; Disease Models, Animal; Male; Memory; Mice; Neuroprotective Agents; Oligopeptides

Neurofibrillary tangles composed of aggregated, hyperphosphorylated tau in an abnormal conformation represent one of the major pathological hallmarks of Alzheimer's disease (AD) and other tauopathies. However, recent data suggest that the pathogenic processes leading to cognitive impairment occur before the formation of classic tangles. In the earliest stages of tauopathy, tau detaches from microtubules and accumulates in the cytosol of the somatodendritic compartment of cells. Either as a cause or an effect, tau becomes hyperphosphorylated and aggregates into paired helical filaments that comprise the tangles. To assess whether an agent that modulates microtubule function can inhibit the pathogenic process and prevent cognitive deficits in a transgenic mouse model with AD-relevant tau pathology, we administered the neuronal tubulin-preferring agent, NAPVSIPQ (NAP). Three months of treatment with NAP at an early-to-moderate stage of tauopathy reduced the levels of hyperphosphorylated soluble and insoluble tau. A 6-month course of treatment improved cognitive function. Although nonspecific tubulin-interacting agents commonly used for cancer therapy are associated with adverse effects due to their anti-mitotic activity, no adverse effects were found after 6 months of exposure to NAP. Our results suggest that neuronal microtubule interacting agents such as NAP may be useful therapeutic agents for the treatment or prevention of tauopathies.

Topics: Alzheimer Disease; Animals; Cognition; Disease Models, Animal; Mice; Mice, Transgenic; Microtubules; Neurons; Oligopeptides; tau Proteins; Tauopathies; Treatment Outcome

Accumulation of beta-amyloid (Abeta) peptide and hyperphosphorylation of tau in the brain are pathological hallmarks of Alzheimer's disease (AD). Agents altering these pathological events might modify clinical disease progression. NAP (Asn-Ala-Pro-Val-Ser-Ile-Pro-Gln) is an octapeptide that has shown neuroprotective effects in various in vitro and in vivo neurodegenerative models. Previous studies showed that NAP protected against Abeta-induced neurotoxicity, inhibited Abeta aggregation, and, by binding to tubulin, prevented disruption of microtubules. In this study, we investigated the effect of NAP on Abeta and tau pathology using a transgenic mouse model that recapitulates both aspects of AD. We administered NAP intranasally (0.5 microg/mouse per day, daily from Monday through Friday) for 3 mo, starting from 9 mo of age, which is a prepathological stage in these mice. NAP treatment significantly lowered levels of Abeta 1-40 and 1-42 in brain. In addition, NAP significantly reduced levels of hyperphosphorylated tau. Of particular interest, hyperphosphorylation at the threonine 231 site was reduced; phosphorylation at this site influences microtubule binding. Our results indicate that NAP treatment of transgenic mice initiated at an early stage reduced both Abeta and tau pathology, suggesting that NAP might be a potential therapeutic agent for AD.

Topics: Administration, Intranasal; Alzheimer Disease; Amyloid beta-Peptides; Animals; Disease Models, Animal; Humans; Mice; Mice, Transgenic; Oligopeptides; Peptides; Phosphorylation; tau Proteins

An 8-amino-acid peptide, NAPVSIPQ (NAP), was identified as the smallest active element of activity-dependent neuroprotective protein that exhibits potent neuroprotective action. Potential signal transduction pathways include cGMP production and interference with inflammatory mechanisms, tumor necrosis factor-alpha, and MAC1-related changes. Because of its intrinsic structure, NAP might interact with extracellular proteins and also transverse membranes. NAP-associated protection against oxidative stress, glucose deprivation, and apoptotic mechanisms suggests interference with fundamental processes. This paper identifies p53, a key regulator of cellular apoptosis, as an intracellular target for NAP's activity.

Topics: Alzheimer Disease; Animals; Apoptosis; Brain; Brain Ischemia; Cyclic GMP; Down-Regulation; Encephalitis; Macrophage-1 Antigen; Neuroprotective Agents; Oligopeptides; Oxidative Stress; PC12 Cells; Rats; Tumor Necrosis Factor-alpha; Tumor Suppressor Protein p53

Alzheimer's disease (AD) is characterized by brain plaques containing the beta-amyloid peptide (Abeta). One approach for treating AD is by blocking Abeta aggregation. Activity-dependent neuroprotective protein contains a peptide, NAP that protects neurons in culture against Abeta toxicity. Here, NAP was shown to inhibit Abeta aggregation using: (1) fluorimetry; (2) electron microscopy; (3) high-throughput screening of Abeta deposition onto a synthetic template (synthaloid); and (4) Congo Red staining of neurons. Further assays showed biotin-NAP binding to Abeta. These results suggest that part of the neuroprotective mechanism exerted by NAP is through modulation of toxic protein folding in the extracellular milieu.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Animals, Newborn; Cell Aggregation; Cells, Cultured; Congo Red; Copper; Microscopy, Electron; Neurons; Oligopeptides; Peptide Fragments; Protein Binding; Protein Structure, Quaternary; Rats