Autism, Schizophrenia and Alzheimer’s Disease : a common thread from neuropeptides to brain regulating genes

Our original cloning of the gene coding for vasoactive intestinal peptide (VIP) (Bodner, Fridkin & Gozes, 1985), led to the identification of VIP’s involvement in synapse formation and neuroprotection, through our discoveries of activity-dependent neurotrophic factor (ADNF) (Brenneman & Gozes, 1996) and activity- dependent neuroprotective protein (ADNP) (Bassan et al., 1999; Zamostiano et al., 2001). To precisely delineate VIP and ADNP activities in the whole animal, we established transgenic animals, showing that manipulating VIP content impacts cognition in the mouse (Gozes et al., 1993). As for mouse ADNP, complete knockout results in severe neuronal tube closure defects and embryonic death at the time of neural tube closure (Pinhasov et al., 2003). ADNP haploinsufficient mice survive and show cognitive and social deficiencies, with pathologies resembling autism (Malishkevich et al., 2015) and Alzheimer’s disease (Vulih-Shultzman et al., 2007). Delineating the mechanism of action of ADNP, we discovered binding to the SWI/SNF chromatin remodeling complex and heterochromatin protein 1 alpha, and direct interaction with specific gene promoters (e.g. the major risk gene for Alzheimer’s disease, apolipoprotein E) (Mandel & Gozes, 2007; Mandel, Rechavi & Gozes, 2007). We have further discovered interactions with proteins associated with RNA splicing (Schirer et al., 2014), as well as with proteins regulating translation, like eukaryotic initiation factor 4E (Eif4e) (Malishkevich et al., 2015). In the cell cytoplasm, ADNP further interacts with the autophagy mechanism, binding to microtubule associated protein 1 light chain 3 (LC3) (Merenlender-Wagner et al., 2015) and to microtubule end binding proteins (EBs) (Oz et al., 2014).peer-reviewe

Tau and Caspase 3 as Targets for Neuroprotection

The peptide drug candidate NAP (davunetide) has demonstrated protective effects in various in vivo and in vitro models of neurodegeneration. NAP was shown to reduce tau hyperphosphorylation as well as to prevent caspase-3 activation and cytochrome-3 release from mitochondria, both characteristic of apoptotic cell death. Recent studies suggest that caspases may play a role in tau pathology. The purpose of this study was to evaluate the effect of NAP on tau hyperphosphorylation and caspase activity in the same biological system. Our experimental setup used primary neuronal cultures subjected to oxygen-glucose deprivation (OGD), with and without NAP or caspase inhibitor. Cell viability was assessed by measuring mitochondrial activity (MTS assay), and immunoblots were used for analyzing protein level. It was shown that apoptosis was responsible for all cell death occurring following ischemia, and NAP treatment showed a concentration-dependent protection from cell death. Ischemia caused an increase in the levels of active caspase-3 and hyperphosphorylated tau, both of which were prevented by either NAP or caspase-inhibitor treatment. Our data suggest that, in this model system, caspase activation may be an upstream event to tau hyperphosphorylation, although additional studies will be required to fully elucidate the cascade of events

VIP-derived sequences modified by N-terminal stearyl moiety induce cell death: the human keratinocyte as a model

AbstractVasoactive intestinal peptide (VIP) is a recognized growth factor affecting many cell types. We have previously developed a series of lipophilic VIP analogues containing an N-terminal covalently attached stearyl moiety. The current studies identified stearyl-Nle17-VIP and stearyl-Nle17-neurotensin6–11VIP7–28, acting at μM concentrations, as cytotoxic to human keratinocytes. The core C-terminal active VIP-derived peptide, stearyl-Lys-Lys-Tyr-Leu-NH2 (St-KKYL-NH2), was identified as being responsible for the observed cytotoxicity. Cytotoxicity coincided with marked reduction in intracellular cyclic GMP and was abolished by co-treatment with the endonuclease inhibitor, aurine-tricarboxylic acid, suggesting apoptotic mechanisms. Stearyl-VIP derivatives thus offer lead compounds for future drug development against hyperproliferative skin conditions

Study of NAP adsorption and assembly on the surface of HOPG

NAP is an octapeptide that has demonstrated a neuroprotective/therapeutic efficacy at very low concentrations in preclinical studies and in a number of clinical trials. Yet little is known about its structural organization at low concentrations. Here, we have employed atomic force microscopy to investigate NAP peptide assembly on graphite in aqueous media at nanomolar concentration. High spatial resolution scans of NAP assemblies reveal their fine structure with clearly resolved single NAP units. This observation leads us to conclude that NAP molecules do not form complex self-assembled structures at nanomolar concentration when adsorbed on graphite surface

Microbiota changes associated with ADNP deficiencies: rapid indicators for NAP (CP201) treatment of the ADNP syndrome and beyond

Activity-dependent neuroprotective protein (ADNP) and its protein snippet NAP (drug candidate CP201) regulate synapse formation and cognitive as well as behavioral functions, in part, through microtubule interaction. Given potential interactions between the microbiome and brain function, we now investigated the potential effects of the ADNP-deficient genotype, mimicking the ADNP syndrome on microbiota composition in the Adnp+/- mouse model. We have discovered a surprising robust sexually dichotomized Adnp genotype effect and correction by NAP (CP201) as follows. Most of the commensal bacterial microbiota tested were affected by the Adnp genotype and corrected by NAP treatment in a male sex-dependent manner. The following list includes all the bacterial groups tested-labeled in bold are male Adnp-genotype increased and corrected (decreased) by NAP. (1) Eubacteriaceae (EubV3), (2) Enterobacteriaceae (Entero), (3) Enterococcus genus (gEncocc), (4) Lactobacillus group (Lacto), (5) Bifidobacterium genus (BIF), (6) Bacteroides/Prevotella species (Bac), (7) Clostridium coccoides group (Coer), (8) Clostridium leptum group (Cluster IV, sgClep), and (9) Mouse intestinal Bacteroides (MIB). No similarities were found between males and females regarding sex- and genotype-dependent microbiota distributions. Furthermore, a female Adnp+/- genotype associated decrease (contrasting male increase) was observed in the Lactobacillus group (Lacto). Significant correlations were discovered between specific bacterial group loads and open-field behavior as well as social recognition behaviors. In summary, we discovered ADNP deficiency associated changes in commensal gut microbiota compositions, a sex-dependent biomarker for the ADNP syndrome and beyond. Strikingly, we discovered rapidly detected NAP (CP201) treatment-dependent biomarkers within the gut microbiota

Critical appraisal of the role of davunetide in the treatment of progressive supranuclear palsy

Progressive supranuclear palsy (PSP) is a rare neurodegenerative disease characterized by the accumulation of tau protein aggregates in the basal ganglia, brainstem and cerebral cortex leading to rapid disease progression and death. The neurofibrillary tangles that define the neuropathology of PSP are comprised of aggregated 4R tau and show a well-defined distribution. Classically, PSP is diagnosed by symptoms that include progressive gait disturbance, early falls, vertical ophthalmoparesis, akinetic-rigid features, prominent bulbar dysfunction and fronto-subcortical dementia. There are currently no effective therapies for the treatment of this rapidly degenerating and debilitating disease. Davunetide is a novel neuroprotective peptide that is thought to impact neuronal integrity and cell survival through the stabilization of microtubules. Preclinical activity in models of tauopathy has been translated to clinical studies, demonstrating pharmacologic activity that has supported further development. Davunetide’s efficacy and tolerability are being tested in a placebo-controlled study in PSP patients, making it the most advanced drug candidate in this indication. This review examines the disease characteristics of PSP, the rationale for treating PSP with davunetide and assesses some of the challenges of clinical trials in this patient population

Immune-modulatory Properties of the Octapeptide NAP in Campylobacter jejuni Infected Mice Suffering from Acute Enterocolitis

Human infections with the food-borne zoonotic pathogen Campylobacter jejuni are progressively rising and constitute serious global public health and socioeconomic burdens. Hence, application of compounds with disease-alleviating properties are required to combat campylobacteriosis and post-infectious sequelae. In our preclinical intervention study applying an acute C. jejuni induced enterocolitis model, we surveyed the anti-pathogenic and immune-modulatory effects of the octapeptide NAP which is well-known for its neuroprotective and anti-inflammatory properties. Therefore, secondary abiotic IL-10-/- mice were perorally infected with C. jejuni and intraperitoneally treated with synthetic NAP from day 2 until day 5 post-infection. NAP-treatment did not affect gastrointestinal C. jejuni colonization but could alleviate clinical signs of infection that was accompanied by less pronounced apoptosis of colonic epithelial cells and enhancement of cell regenerative measures on day 6 post-infection. Moreover, NAP-treatment resulted in less distinct innate and adaptive pro-inflammatory immune responses that were not restricted to the intestinal tract but could also be observed in extra-intestinal and even systemic compartments. NAP-treatment further resulted in less frequent translocation of viable pathogens from the intestinal tract to extra-intestinal including systemic tissue sites. For the first time, we here provide evidence that NAP application constitutes a promising option to combat acute campylobacteriosis

A multi-lab experimental assessment reveals that replicability can be improved by using empirical estimates of genotype-by-lab interaction.

The utility of mouse and rat studies critically depends on their replicability in other laboratories. A widely advocated approach to improving replicability is through the rigorous control of predefined animal or experimental conditions, known as standardization. However, this approach limits the generalizability of the findings to only to the standardized conditions and is a potential cause rather than solution to what has been called a replicability crisis. Alternative strategies include estimating the heterogeneity of effects across laboratories, either through designs that vary testing conditions, or by direct statistical analysis of laboratory variation. We previously evaluated our statistical approach for estimating the interlaboratory replicability of a single laboratory discovery. Those results, however, were from a well-coordinated, multi-lab phenotyping study and did not extend to the more realistic setting in which laboratories are operating independently of each other. Here, we sought to test our statistical approach as a realistic prospective experiment, in mice, using 152 results from 5 independent published studies deposited in the Mouse Phenome Database (MPD). In independent replication experiments at 3 laboratories, we found that 53 of the results were replicable, so the other 99 were considered non-replicable. Of the 99 non-replicable results, 59 were statistically significant (at 0.05) in their original single-lab analysis, putting the probability that a single-lab statistical discovery was made even though it is non-replicable, at 59.6%. We then introduced the dimensionless Genotype-by-Laboratory (GxL) factor-the ratio between the standard deviations of the GxL interaction and the standard deviation within groups. Using the GxL factor reduced the number of single-lab statistical discoveries and alongside reduced the probability of a non-replicable result to be discovered in the single lab to 12.1%. Such reduction naturally leads to reduced power to make replicable discoveries, but this reduction was small (from 87% to 66%), indicating the small price paid for the large improvement in replicability. Tools and data needed for the above GxL adjustment are publicly available at the MPD and will become increasingly useful as the range of assays and testing conditions in this resource increases