Human Neuroblastoma Cell Cultures Research Articles

The Antidepressant Drug Amitriptyline Affects Human SH-SY5Y Neuroblastoma Cell Proliferation and Modulates Autophagy.

Amitriptyline is a tricyclic antidepressant commonly used for depressive disorders and is prescribed off-label for several neurological conditions like neuropathic pain, migraines and anxiety. Besides their action on the reuptake of monoaminergic neurotransmitters, tricyclic antidepressants interact with several additional targets that may contribute to either therapeutic or adverse effects. Here, we investigated the effects of amitriptyline on proliferation and autophagy (i.e., an evolutionarily conserved catabolic pathway responsible for the degradation and recycling of cytoplasmic material) in human SH-SY5Y neuroblastoma cell cultures. The dose and time-dependent upregulation of the autophagy marker LC3II and the autophagy receptor p62, with the accumulation of LAMP1 positive compartments, were observed in SH-SY5Y cells exposed to the amitriptyline. These effects were accompanied by reduced cell viability and decreased clonogenic capacity, without a significant induction of apoptosis. Decrease viability and clonogenic activity were still observed in autophagy deficient Atg5-/- MEF and following pre-treatment of SH-SY5Y culture with the autophagy inhibitor chloroquine, suggesting that they were independent from autophagy modulation. Our findings demonstrate that amitriptyline acts on pathways crucial for cell and tissue homeostasis (i.e., autophagy and proliferation) and pose the basis for further studies on the potential therapeutic application of amitriptyline, as well as the consequences of its use for long-term treatments.

The epigenetic signatures of opioid addiction and physical dependence are prevented by D-cysteine ethyl ester and betaine.

We have reported that D,L-thiol esters, including D-cysteine ethyl ester (D-CYSee), are effective at overcoming opioid-induced respiratory depression (OIRD) in rats. Our on-going studies reveal that co-injections of D-CYSee with multi-day morphine injections markedly diminish spontaneous withdrawal that usually occurs after cessation of multiple injections of morphine in rats. Chronically administered opioids are known (1) to alter cellular redox status, thus inducing an oxidative state, and (2) for an overall decrease in DNA methylation, therefore resulting in the transcriptional activation of previously silenced long interspersed elements (LINE-1) retrotransposon genes. The first objective of the present study was to determine whether D-CYSee and the one carbon metabolism with the methyl donor, betaine, would maintain redox control and normal DNA methylation levels in human neuroblastoma cell cultures (SH-SY5Y) under overnight challenge with morphine (100nM). The second objective was to determine whether D-CYSee and/or betaine could diminish the degree of physical dependence to morphine in male Sprague Dawley rats. Our data showed that overnight treatment with morphine reduced cellular GSH levels, induced mitochondrial damage, decreased global DNA methylation, and increased LINE-1 mRNA expression. These adverse effects by morphine, which diminished the reducing capacity and compromised the maintenance of the membrane potential of SH-SY5Y cells, was prevented by concurrent application of D-CYSee (100µM) or betaine (300µM). Furthermore, our data demonstrated that co-injections of D-CYSee (250μmol/kg, IV) and to a lesser extent, betaine (250μmol/kg, IV), markedly diminished the development of physical dependence induced by multi-day morphine injections (escalating daily doses of 10-30mg/kg, IV), as assessed by the lesser number of withdrawal phenomena elicited by the injection of the opioid receptor antagonist, naloxone (1.5mg/kg, IV). These findings provide evidence that D-CYSee and betaine prevent the appearance of redox alterations and epigenetic signatures commonly seen in neural cells involved in opioid physical dependence/addiction, and lessen development of physical dependence to morphine.

Rifampicin Inhibits TLR4 and IL1β Gene Expression and Enhances SH-SY5Y Cell Viability After Prolonged Ethanol Exposure in an In Vitro Experiment

Prolonged alcohol exposure activates TLR4-signaling pathways in the brain, responsible for the development of neuroinflammation. There is interest in pharmacologic correction of these mechanisms. The antibiotic rifampicin (Rif) is known as a potential neuroprotectant which can correct various pathologic conditions of the nervous system associated with the development of neuroinflammatory events. We performed a study on human neuroblastoma cell culture SH-SY5Y. Prolonged incubation of SH-SY5Y cells with ethanol (24 h, 100 mM) of induced activation the innate immune system genes Tlr4 and Il1β. Pre-treatment with Rif (25-100 mM) prior to incubation of cells with ethanol inhibited Tlr4 and Il1β gene expression, whereas addition of Rif after incubation of cells with ethanol dose-dependently reduced the increased expression of Tlr4 and Il1β genes, with the most significant effect observed at a concentration of 100 mM. In addition, the use of Rif increased cell survival in culture. Thus, the results of our experiment has shown that Rif is able to eliminate the increased expression of inflammation genes caused by prolonged alcohol exposure and to increase the survival rate of long-term incubated cells in ethanol solution.

Neuroprotective and antioxidant properties of new quinolylnitrones in in vitro and in vivo cerebral ischemia models

Cerebral ischemia is a condition affecting an increasing number of people worldwide, and the main cause of disability. Current research focuses on the search for neuroprotective drugs for its treatment, based on the molecular targets involved in the ischemic cascade. Nitrones are potent antioxidant molecules that can reduce oxidative stress. Here we report the neuroprotective properties and the antioxidant power of the six new quinolylnitrones (QNs) 1–6 for their potential application in stroke therapy. QNs 1–4 are 2-chloro-8-hydroxy-substituted QNs bearing N-t-butyl or N-benzyl substituents at the nitrone motif located at C3, whereas QN5 and QN6 are 8-hydroxy QNs bearing N-t-butyl or N-benzyl substituents at the nitrone motif located at C2, respectively. In vitro neuroprotection studies using QNs 1–6 in an oxygen-glucose-deprivation model of cerebral ischemia, in human neuroblastoma cell cultures, indicate that all QNs have promising neuroprotective, anti-necrotic, anti-apoptotic, and anti-oxidant properties against experimental ischemia–reperfusion in neuronal cultures. QN6 stands out as the most balanced nitrone out of all tested QNs, as it strongly prevents decreased neuronal metabolic activity (EC50 = 3.97 ± 0.78 μM), as well as necrotic (EC50 = 3.79 ± 0.83 μM) and apoptotic cell death (EC50 = 3.99 ± 0.21 μM). QN6 showed high capacity to decrease superoxide production (EC50 = 3.94 ± 0.76 μM), similar to its parent molecule α-phenyl-tert-butyl nitrone (PBN) and the well-known anti-oxidant molecule N-acetyl-l-cysteine (NAC). Thus, QN6 demonstrated the highest antioxidant power out of the other tested QNs. Finally, in vivo treatment with QN6 in an experimental permanent stroke model elicited a significant reduction (75.21 ± 5.31%) of the volume size of brain lesion. Overall, QN6 is a potential agent for the therapy of cerebral ischemia that should be further investigated.

Anti-Inflammatory Activity of Soluble Epoxide Hydrolase Inhibitors Based on Selenoureas Bearing an Adamantane Moiety.

The inhibitory potency of the series of inhibitors of the soluble epoxide hydrolase (sEH) based on the selenourea moiety and containing adamantane and aromatic lipophilic groups ranges from 34.3 nM to 1.2 μM. The most active compound 5d possesses aliphatic spacers between the selenourea group and lipophilic fragments. Synthesized compounds were tested against the LPS-induced activation of primary murine macrophages. The most prominent anti-inflammatory activity, defined as a suppression of nitric oxide synthesis by LPS-stimulated macrophages, was demonstrated for compounds 4a and 5b. The cytotoxicity of the obtained substances was studied using human neuroblastoma and fibroblast cell cultures. Using these cell assays, the cytotoxic concentration for 4a was 4.7–18.4 times higher than the effective anti-inflammatory concentration. The genotoxicity and the ability to induce oxidative stress was studied using bacterial lux-biosensors. Substance 4a does not exhibit genotoxic properties, but it can cause oxidative stress at concentrations above 50 µM. Put together, the data showed the efficacy and safety of compound 4a.

Ameliorative Effects by Hexagonal Boron Nitride Nanoparticles against Beta Amyloid Induced Neurotoxicity.

Alzheimer’s disease (AD) is considered as the most common neurodegenerative disease. Extracellular amyloid beta (Aβ) deposition is a hallmark of AD. The options based on degradation and clearance of Aβ are preferred as promising therapeutic strategies for AD. Interestingly, recent findings indicate that boron nanoparticles not only act as a carrier but also play key roles in mediating biological effects. In the present study, the aim was to investigate the effects of different concentrations (0–500 mg/L) of hexagonal boron nitride nanoparticles (hBN-NPs) against neurotoxicity by beta amyloid (Aβ1-42) in differentiated human SH-SY5Y neuroblastoma cell cultures for the first time. The synthesized hBN-NPs were characterized by X-ray diffraction (XRD) measurements, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Aβ1-42-induced neurotoxicity and therapeutic potential by hBN-NPs were assessed on differentiated SH-SY5Y cells using MTT and LDH release assays. Levels of total antioxidant capacity (TAC) and total oxidant status (TOS), expression levels of genes associated with AD and cellular morphologies were examined. The exposure to Aβ1-42 significantly decreased the rates of viable cells which was accompanied by elevated TOS level. Aβ1-42 induced both apoptotic and necrotic cell death. Aβ exposure led to significant increases in expression levels of APOE, BACE 1, EGFR, NCTSN and TNF-α genes and significant decreases in expression levels of ADAM 10, APH1A, BDNF, PSEN1 and PSENEN genes (p < 0.05). All the Aβ1-42-induced neurotoxic insults were inhibited by the applications with hBN-NPs. hBN-NPs also suppressed the remarkable elevation in the signal for Aβ following exposure to Aβ1-42 for 48 h. Our results indicated that hBN-NPs could significantly prevent the neurotoxic damages by Aβ. Thus, hBN-NPs could be a novel and promising anti-AD agent for effective drug development, bio-nano imaging or drug delivery strategies.

Neuroprotective effect of the positive allosteric modulator of the mglur2 jnj-46356479 in human neuroblastoma cell cultures

Neuroprotective effect of the positive allosteric modulator of the mglur2 jnj-46356479 in human neuroblastoma cell cultures

Interaction of Prion Peptides with DNA Structures.

Prion protein aggregation is known to be modulated by macromolecules including nucleic acids. To clarify the role of nucleic acids in PrP pathology, we investigated the interaction between nucleic acids and the prion peptide (PrP)—a synthetic prion protein model peptide resembling a portion of the human prion protein in structure and function spanning amino acid residues 106–126. We used synthetic DNA lattices and natural DNA duplexes extracted from salmon (sDNA) bound with PrP and studied their interaction using distinct physical measurements. The formation of DNA lattices with PrP was visualized by atomic force microscopy (AFM) to investigate the influence of the PrP. PrP inhibited the growth of the double-crossover (DX) lattices significantly compared to the control peptide (CoP). We also conducted optical measurements such as ultraviolet–visible (UV–Vis), circular dichroism (CD), and Fourier transform infrared (FTIR) spectroscopies to validate the interaction between PrP and DNA immediately (D0) and after a 30-day incubation (D30) period. UV–Vis spectra showed variation in the absorbance intensities, specific for the binding of CoP and PrP to DNA. The CD analysis revealed the presence of various secondary structures, such as α-helices and β-sheets, in PrP- and PrP-bound sDNA complexes. The PrP–sDNA interaction was confirmed using FTIR by the change and shift of the absorption peak intensity and the alteration of PrP secondary structures in the presence of DNA. The cytotoxic effects of the PrP-bound sDNA complexes were assessed by a cytotoxicity assay in human neuroblastoma cells in culture. It confirmed that PrP with sDNA was less cytotoxic than CoP. This study provides new applications for DNA molecules by investigating their effect in complex with aggregated proteins. Our study unequivocally showed the beneficial effect of the interaction between DNA and the pathological prion protein. It therefore provides valuable information to exploit this effect in the development of potential therapeutics. Moreover, our work might serve as a basis for further studies investigating the role of DNA interactions with other amyloidogenic proteins.

Synthesis, antioxidant properties and neuroprotection of \u03b1-phenyl-tert-butylnitrone derived HomoBisNitrones in in vitro and in vivo ischemia models

We herein report the synthesis, antioxidant power and neuroprotective properties of nine homo-bis-nitrones HBNs1–9 as alpha-phenyl-N-tert-butylnitrone (PBN) analogues for stroke therapy. In vitro neuroprotection studies of HBNs1–9 against Oligomycin A/Rotenone and in an oxygen-glucose-deprivation model of ischemia in human neuroblastoma cell cultures, indicate that (1Z,1′Z)-1,1′-(1,3-phenylene)bis(N-benzylmethanimine oxide) (HBN6) is a potent neuroprotective agent that prevents the decrease in neuronal metabolic activity (EC50 = 1.24 ± 0.39 μM) as well as necrotic and apoptotic cell death. HBN6 shows strong hydroxyl radical scavenger power (81%), and capacity to decrease superoxide production in human neuroblastoma cell cultures (maximal activity = 95.8 ± 3.6%), values significantly superior to the neuroprotective and antioxidant properties of the parent PBN. The higher neuroprotective ability of HBN6 has been rationalized by means of Density Functional Theory calculations. Calculated physicochemical and ADME properties confirmed HBN6 as a hit-agent showing suitable drug-like properties. Finally, the contribution of HBN6 to brain damage prevention was confirmed in a permanent MCAO setting by assessing infarct volume outcome 48 h after stroke in drug administered experimental animals, which provides evidence of a significant reduction of the brain lesion size and strongly suggests that HBN6 is a potential neuroprotective agent against stroke.

Clay-based hybrids for controlled release of 7-azaindole derivatives as neuroprotective drugs in the treatment of Alzheimer's disease

Hybrid systems based on clay minerals and 7-azaindole derivatives, which show an interesting neuroprotective profile in several in vitro models of neurodegeneration, were developed in order to facilitate the oral administration of these drugs in the treatment of Alzheimer's disease and provide a controlled release. Two 7-azaindole derivatives with different substitution at position 5 (-OCH3, -H) were synthesized and adsorbed on nanocarriers of different morphology, the lamellar clay montmorillonite (MMT) and the halloysite nanotubes (HNT). The drugs intercalation in MMT was confirmed by X-ray diffraction, obtaining basal spacing values around 1.9–2.0 nm in the hybrids, with a drug loading around 31–36 g per 100 g of MMT, while the HNT-based hybrids show an uptake of 15–21 g per 100 g of HNT. Studies carried out in cultures of human neuroblastoma cells confirmed the lack of toxicity of the hybrids and their neuroprotective effect against okadaic acid (OA), the inhibitor of the protein phosphatase 2A (PP2A), similarly to the non-encapsulated drugs. The release assays carried out in systems that simulate the gastrointestinal tract show a rapid release of the drugs from the hybrid materials, making necessary their encapsulation in a protective biopolymer matrix to slow down the release kinetics. A blend of alginate and zein was chosen for this purpose, exploiting the gelation of alginate with calcium ions to process the material as microbeads and the hydrophobic character of zein to reduce the water uptake of the material. Therefore, these bionanocomposite systems integrating the drug/clay hybrids seem promising for the oral administration of drugs with multitarget activity for the treatment of Alzheimer's disease.

In vitro cellular uptake and neuroprotective efficacy of poly-arginine-18 (R18) and poly-ornithine-18 (O18) peptides: critical role of arginine guanidinium head groups for neuroprotection.

We have previously demonstrated that Cationic Arginine-Rich Peptides (CARPs) and in particular poly-arginine-18 (R18; 18-mer of arginine) exhibit potent neuroprotective properties in both in vitro and in vivo neuronal injury models. Based on the current literature, there is a consensus that arginine residues by virtue of their positive charge and guanidinium head group is the critical element for imparting CARP neuroprotective properties and their ability to traverse cell membranes. This study examined the importance of guanidinium head groups in R18 for peptide cellular uptake, localization, and neuroprotection. This was achieved by using poly-ornithine-18 (O18; 18-mer of ornithine) as a control, which is structurally identical to R18, but possesses amino head groups rather than guanidino head groups. Epifluorescence and confocal fluorescence microscopy was used to examine the cellular uptake and localization of the FITC-conjugated R18 and O18 in primary rat cortical neurons and SH-SY5Y human neuroblastoma cell cultures. An in vitro cortical neuronal glutamic acid excitotoxicity model was used to compare the effectiveness of R18 and O18 to inhibit cell death and intracellular calcium influx, as well as caspase and calpain activation. Fluorescence imaging studies revealed cellular uptake of both FITC-R18 and FITC-O18 in neuronal and SH-SY5Y cells; however, intracellular localization of the peptides differed in neurons. Following glutamic acid excitotoxicity, only R18 was neuroprotective, prevented caspases and calpain activation, and was more effective at reducing neuronal intracellular calcium influx. Overall, this study demonstrated that for long chain cationic poly-arginine peptides, the guanidinium head groups provided by arginine residues are an essential requirement for neuroprotection but are not required for entry into neurons.

Detailed Dissection of UBE3A-Mediated DDI1 Ubiquitination.

The ubiquitin E3 ligase UBE3A has been widely reported to interact with the proteasome, but it is still unclear how this enzyme regulates by ubiquitination the different proteasomal subunits. The proteasome receptor DDI1 has been identified both in Drosophila photoreceptor neurons and in human neuroblastoma cells in culture as a direct substrate of UBE3A. Here, we further characterize this regulation, by identifying the UBE3A-dependent ubiquitination sites and ubiquitin chains formed on DDI1. Additionally, we found one deubiquitinating enzyme that is capable of reversing the action of UBE3A on DDI1. The complete characterization of the ubiquitination pathway of an UBE3A substrate is important due to the role of this E3 ligase in rare neurological disorders as Angelman syndrome.

Neuroprotective effect of astaxanthin (ATX) against cognitive impairment on PTZ-induced epileptic seizures in rats and against PTZ-induced neurotoxicity in SH-SY5Y human neuroblastoma cell culture

Objective: Epilepsy is a common brain disorder that seizures could cause neuronal loss in the hippocampus. Oxidative stress has an important role in the pathology of this way. The aim of this study was to investigate the neuroprotective effect of astaxanthin (ATX), on pentylenetetrazole (PTZ) induced epileptic seizures in rats and in SH-SY5Y human neuroblastoma cell culture . Method: In our study, we used 42 male 230-250 g Wistar Albino rats. Animals were divided into seven groups as control, saline (PTZ; 1 ml/kg serum physiologic), positive control (2,5 mg/kg diazepam), 10 mg/kg, 20 mg/kg, 40 mg/kg and 80 mg/kg ATX for seven days. Thirty min after the administration of the last drug at the indicated doses, PTZ was administered 45 mg/kg to induce an epileptic seizure. The animals were observed for 30 min. Seizure stages according to the Racine Scale (RC) and first myoclonic jerk times (FMJ). Twenty four hours after PTZ injection, passive avoidance test was performed, and then brain tissues were removed for biochemical and histopathological evaluation. The hippocampal Cornu Ammonis 1 (CA1), CA3 and dentate gyrus (DG) regions were evaluated histopathologically regarding neuronal damage. Besides, oxidative stress markers total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI)) were measured in brain tissues. Furthermore, ATX was performed in vitro SH-SY5Y human neuroblastoma cell culture to evaluate PTZ-induced neurotoxicity. Results: When epileptic behaviors were evaluated, ATX did not affect RC and FMJ (p>0, 05). However, ATX reduced both cognitive impairment in passive avoidance test and neuronal damage in the hippocampus (p<0, 05). Moreover, ATX reduced both TOS levels and OSI in the brain (p<0, 05). Besides of these in vitro studies, ATX increased neuronal viability in vitro. Conclusions: Although ATX does not have antiepileptic properties directly, it has a protective effect on not only in vivo but also in vitro. These effects may occur by possible oxidative pathways.

Micro X-ray fluorescence elemental analysis of spheroid cultures of human neuroblastoma cells

Neuroblastoma (NB) is a malignancy of the sympathetic nervous system that almost exclusively occurs during infancy and early childhood. NB is responsible for 8–10% of all childhood cancers. More than 50% of the diagnosed cases have metastatic disease at the time of diagnosis. Trace elements are extremely important in biological processes, including reactions involving metabolic enzymes and gene expression. Micro X-ray fluorescence (µXRF) is an important tool since it is a non-destructive technique for the analysis of sample composition. Elemental distributions in spheroids of human neuroblastoma cells were investigated using a commercial μXRF system, which detected seven elements: P, S, Cl, K, Ca, Fe and Zn. Mapping by µXRF was performed to investigate the spatial distribution of all detected elements. Results of µXRF revealed a non-uniform distribution of elements in all the spheroids analyzed. The results of this work can serve as a baseline for studies investigating the role of trace elements in NB.

Synthesis, neuroprotective and antioxidant capacity of PBN-related indanonitrones

In this work six PBN-related indanonitrones 1–6 have been designed, synthesized, and their neuroprotection capacity tested in vitro, under OGD conditions, in SH-SY5Y human neuroblastoma cell cultures. As a result, we have identified indanonitrones 1, 3 and 4 (EC50 = 6.64 ± 0.28 μM) as the most neuroprotective agents, and in particular, among them, indanonitrone 4 was also the most potent and balanced nitrone, showing antioxidant activity in three experiments [LOX (100 μM), APPH (51%), DPPH (36.5%)], being clearly more potent antioxidant agent than nitrone PBN. Consequently, we have identified (Z)-5-hydroxy-N-methyl-2,3-dihydro-1H-inden-1-imine oxide (4) as a hit-molecule for further investigation.

Identification and characterization of synthetic chondroitin-4-sulfate binding peptides in neuronal functions

Chondroitin sulfate proteoglycans (CSPGs), up-regulated in and around the glial scar after mammalian spinal cord injury, have been suggested to be key inhibitory molecules for functional recovery by impeding axonal regrowth/sprouting and synaptic rearrangements. CSPG-mediated inhibition is mainly associated with the glycosaminoglycan chains of CSPGs, and chondroitin-4-sulfate (C4S) is the predominant sulfated structure that regulates axonal guidance and growth in the adult nervous system. With the aim to find molecules that neutralize the inhibitory functions of C4S, we screened a phage display library for peptides binding to C4S. From the phage clones binding to C4S we selected three peptides for further analysis. We observed that these peptides bind to C4S, but not chondroitin-6-sulfate, heparin sulfate or dermatan sulfate, in a concentration-dependent and saturable manner, whereas the scrambled peptides showed highly reduced or no binding to C4S. The C4S-binding peptides, but not their scrambled counterparts, when added to cultures of mouse cerebellar neurons and human neuroblastoma cells, neutralized the inhibitory functions of the C4S- and CSPG-coated substrate on cell adhesion, neuronal migration and neurite outgrowth. These results indicate that the C4S-binding peptides neutralize several inhibitory functions of CSPGs, suggesting that they may be beneficial in repairing mammalian nervous system injuries.

The Alzheimer's disease THErapy with NEuroaid (ATHENE) study protocol: Assessing the safety and efficacy of Neuroaid II (MLC901) in patients with mild-to-moderate Alzheimer's disease stable on cholinesterase inhibitors or memantine—A randomized, double-blind, placebo-controlled trial

BackgroundDementia is a large and growing health care burden globally, and its major cause is Alzheimer's disease (AD). MLC901 (Neuroaid II) is a simplified form of MLC601 (Neuroaid), a Traditional Chinese Medicine with neuroprotective and neuroproliferative properties in cellular and animal models of brain injury. MLC601 has been shown to modulate amyloid precursor protein (APP) processing in human neuroblastoma cell cultures and increase the levels of soluble APPα. In addition, MLC901 has been shown to reduce tau phosphorylation in vitro. Hence, MLC901 may have possible multimodal actions and a disease-modifying effect in AD. In previous clinical studies, MLC601 has shown promising effects in AD. ObjectiveTo investigate the safety and efficacy of MLC901 add-on therapy to standard treatment in mild-to-moderate probable AD patients stable on standard treatment and to evaluate if MLC901 has a disease-modifying effect in AD. MethodsThis is a 6-month randomized, double-blind, placebo-controlled trial in mild-to-moderate probable AD where MLC901 will be given as an add-on therapy to standard AD treatment, followed by an extension study for another 6 months, where all subjects will be treated with open-label MLC901 in addition to standard treatment. The primary outcome is safety as measured by adverse events, vital signs, electrocardiogram, laboratory tests, and physical and neurological examinations. Secondary outcomes evaluating cognition, behavior, and activities of daily living at various time points include the Alzheimer's Disease Assessment Scale–cognitive subscale, Alzheimer's Disease Cooperative Study–Clinical Global Impression of Change, Alzheimer's Disease Cooperative Study–Activities of Daily Living Inventory, Neuropsychiatric Inventory, and Mini–Mental State Examination. ConclusionMLC901 has the potential to improve cognition in AD patients. It may also have a role in delaying disease progression. This study will be the first to provide safety and efficacy data for MLC901 in mild-to-moderate probable AD patients already receiving standard therapy.

Structure–Activity (Antihypoxic) Relationship in a Series of Substituted Glyprolines

A series of C-substituted N-phenylacetylglycylprolines were synthesized. Their structure-activity (antihypoxic) relationship was studied in normobaric hypoxia tests at i.p. doses of 0.1 – 1 mg/kg as a function of the C-substitution. The amide and ethyl ester of N-phenylacetylglycyl-L-proline exhibited antihypoxic activity and could cyclize in biological fluids to form cycloprolylglycine that was identical to the endogenous peptide with antihypoxic, neuroprotective, and other types of neuropsychotropic activity. The antihypoxic effect was stereospecific because the D-enantiomers were inactive. These compounds at concentrations of 10–7 – 10–5 M also exhibited neuroprotective activity for SH-SY5Y human neuroblastoma cell culture with 6-hydroxydopamine neurotoxicity. The methylamide and analogous free acid of N-phenylacetylglycylproline could not be cyclized into cycloprolylglycine and were inactive. It was concluded that the activity of the substituted glyprolines was associated with their conversion into cycloprolylglycine.

GD2 ganglioside-binding antibody 14G2a and specific aurora A kinase inhibitor MK-5108 induce autophagy in IMR-32 neuroblastoma cells

The process of autophagy and its role in survival of human neuroblastoma cell cultures was studied upon addition of an anti-GD2 ganglioside (GD2) 14G2a mouse monoclonal antibody (14G2a mAb) and an aurora A kinase specific inhibitor, MK-5108. It was recently shown that combination of these agents significantly potentiates cytotoxicity against IMR-32 and CHP-134 neuroblastoma cells in vitro, as compared to the inhibitor used alone. In this study we gained mechanistic insights on autophagy in the observed cytotoxic effects exerted by both agents using cytotoxicity assays, RT-qPCR, immunoblotting, and autophagy detection methods. Enhancement of the autophagy process in the 14G2a mAb- and MK-5108-treated IMR-32 cells was documented by assessing autophagic flux. Application of a lysosomotropic agent—chloroquine (CQ) affected the 14G2a mAb- and MK-5108-stimulated autophagic flux. It is our conclusion that the 14G2a mAb (40 μg/ml) and MK-5108 inhibitor (0.1 μM) induce autophagy in IMR-32 cells. Moreover, the combinatorial treatment of IMR-32 cells with the 14G2a mAb and CQ significantly potentiates cytotoxic effect, as compared to CQ used alone. Most importantly, we showed that interfering with autophagy at its early and late step augments the 14G2a mAb-induced apoptosis, therefore we can conclude that inhibition of autophagy is the primary mechanism of the CQ-mediated sensitization to the 14G2a mAb-induced apoptosis. Although, there was no virtual stimulation of autophagy in the 14G2a mAb-treated CHP-134 neuroblastoma cells, we were able to show that PHLDA1 protein positively regulates autophagy and this process exists in a mutually exclusive manner with apoptosis in PHLDA1-silenced CHP-134 cells.

P.1.017 - New link between inflammation and schizophrenia: IgG with nuclease activity

Introduction Schizophrenia is known to be associated with the disorganization of neurotransmission processes in the brain as well as immunological disturbances [1]. Inflammation in the perinatal period can lead to a violation of synaptic plasticity and pruning of synapses in the adulthood [2]. Also, microRNAs play an important role in neuronal development. The microRNA expression profiles in the circulation and brain are altered in schizophrenia. It is shown that a change in the levels of microRNAs in the blood serum or brain leads to a violation of behavior [3]. We have shown that the formation of catalytic antibodies (abzymes) is one of the signs of immune system pathology. Catalytic antibodies hydrolyzing DNA were detected in the serum of patients with schizophrenia [4]. We assume that antibodies hydrolyzing the circulating regulatory nucleic acids can play a role in schizophrenia pathogenesis. Objectives To investigate a) microRNA-hydrolyzing activity of IgG antibodies from the serum of patients with schizophrenia; b) correlation of the microRNA-hydrolyzing activity level with clinical features of the disease; c) the cytotoxicity of isolated IgG on the human neuroblastoma cell culture IMR-32. Materials and Methods In our study, 35 patients with a verified diagnosis of simple or paranoid schizophrenia and 20 healthy donors were included. The average age in the group of patients was 35.8±8.9 years, duration of disease – 9.1±5.4 years. Electrophoretically and immunologically homogeneous IgGs were obtained by affinity chromatography of the serum proteins under conditions removing non-specifically bound proteins. The microRNA-hydrolyzing activity of IgG was detected by the level of hydrolysis of two neuro-specific fluorescently labeled microRNAs (miR-137 and miR-219a-2-3p). The products of the hydrolysis were analyzed by PAGE under denaturing conditions using laser scanner. Cytotoxicity of antibodies on human neuroblastoma cell culture IMR-32 was studied using MTT-test. Statistical analysis was carried out using the Pearson’s correlation in the Statistica 10 software. Results We have shown for the first time that IgG from all schizophrenia patients possesses microRNA-hydrolyzing activity. Using strict criteria, we proved that the observed activity is an intrinsic property of IgGs in schizophrenia. Interestingly, the microRNA-hydrolyzing activity level on miR-137 is strongly negatively correlated with the disease duration (R=–0.879). The activity decreased with increasing duration of the disease. Also, the level of RNase activity on miR-219a-2-3p was positively correlated with the values of the General Psychopathology PANSS scale and the PANSS Total score (R>0.8). It was shown that the RNase activity is metal-dependent. The kinetic parameters of nuclease reactions catalyzed by IgG were significantly lower than that for native enzymes. Besides, we detected the major hydrolysis sites of two neuro-specific microRNAs. Also, we show that IgG from schizophrenia patients with nuclease activity reduced the survival rate neuroblastoma IMR-32 cell culture by 10-28%. Conclusion We propose that immunological disorders can play an important role in schizophrenia, especially in the prodromal period. The environment and genetic predisposition can lead to inflammation and the formation of antibodies hydrolyzing the microRNAs. These antibodies can contribute to changes in the level of circulating microRNAs and schizophrenia development.