Comprehensive safety evaluation of a novel multitargeting compound XYY-CP1106: A candidate for Alzheimer's disease.

Multitargeting has become a promising strategy for the development of anti-Alzheimer's disease (AD) drugs, considering the complexity of molecular mechanisms in AD pathology. In most pre-clinical studies, the effectiveness of these multi-targeted anti-AD drugs has been demonstrated but comprehensive safety assessments are lacking. Here, the safety evaluation of a novel multi-targeted candidate in AD (XYY-CP1106), characterized by its dual-property of iron chelation and monoamine oxidase B inhibition, was conducted by multifaceted analysis. Acute toxicity in mice was conducted to investigate the safety of oral administration and the maximum tolerated dose of the agent. In vitro Ames analysis, CHL chromosomal aberration analysis, and bone marrow micronucleus analysis were executed to evaluate the genotoxicity. A teratogenesis investigation in pregnant mice were meticulously performed to evaluate the teratogenesis of XYY-CP1106. Furthermore, a 90-day long-term toxicity analysis in rats was investigated to evaluate the cumulative toxicity after long-term administration. Strikingly, no toxic phenomena were found in all investigations, demonstrating relatively high safety profile of the candidate compound. The securing of safety heightened the translational significance of XYY-CP1106 as a novel multi-targeted anti-AD candidate, supporting the rationality of multitargeting strategy in the designs of smart anti-AD drugs.

Untargeted Metabolomic Profiling of Cuprizone-Induced Demyelination in Mouse Corpus Callosum by UPLC-Orbitrap/MS Reveals Potential Metabolic Biomarkers of CNS Demyelination Disorders.

Multiple sclerosis (MS) is a neurodegenerative disorder characterized by periodic neuronal demyelination, which leads to a range of symptoms and eventually to disability. The goal of this research was to use UPLC-Orbitrap/MS to identify validated biomarkers and explore the metabolic mechanisms of MS in mice. Thirty-two C57BL/6 male mice were randomized into two groups that were fed either normal food or 0.2% CPZ for 11 weeks. The mouse demyelination model was assessed by LFB and the expression of MBP by immunofluorescence and immunohistochemistry. The metabolites of the corpus callosum were quantified using UPLC-Orbitrap/MS. The mouse pole climbing experiment was used to assess coordination ability. Multivariate statistical analysis was adopted for screening differential metabolites, and the ingenuity pathway analysis (IPA) was used to reveal the metabolite interaction network. We successfully established the demyelination model. The CPZ group slowly lost weight and showed an increased pole climbing time during feeding compared to the CON group. A total of 81 metabolites (VIP > 1 and P < 0.05) were determined to be enriched in 24 metabolic pathways; 41 metabolites were markedly increased, while 40 metabolites were markedly decreased in the CPZ group. The IPA results revealed that these 81 biomarker metabolites were associated with neuregulin signaling, PI3K-AKT signaling, mTOR signaling, and ERK/MAPK signaling. KEGG pathway analysis showed that two significantly different metabolic pathways were enriched, namely, the glycerophospholipid and sphingolipid metabolic pathways, comprising a total of nine biomarkers. Receiver operating characteristic analysis showed that the metabolites (e.g., PE (16 : 0/22 : 6(4Z, 7Z, 10Z, 13Z, 16Z, 19Z)), PC (18 : 0/22 : 4(7Z, 10Z, 13Z, 16Z)), cytidine 5'-diphosphocholine, PS (18 : 0/22 : 6(4Z, 7Z, 10Z, 13Z, 16Z, 19Z)), glycerol 3-phosphate, SM (d18 : 0/16 : 1(9Z)), Cer (d18:1/18 : 0), galabiosylceramide (d18:1/18 : 0), and GlcCer (d18:1/18 : 0)) have good discrimination ability for the CPZ group. In conclusion, the differential metabolites have great potential to serve as biomarkers of demyelinating diseases. In addition, we identified metabolic pathways associated with CPZ-induced demyelination pathogenesis, which provided a new perspective for understanding the relationship between metabolites and CNS demyelination pathogenesis.

Elezanumab, a clinical stage human monoclonal antibody that selectively targets repulsive guidance molecule A to promote neuroregeneration and neuroprotection in neuronal injury and demyelination models.

Repulsive guidance molecule A (RGMa) is a potent inhibitor of axonal growth and a regulator of neuronal cell death. It is up-regulated following neuronal injury and accumulates in chronic neurodegenerative diseases. Neutralizing RGMa has the potential to promote neuroregeneration and neuroprotection. Previously we reported that a rat anti-N terminal RGMa (N-RGMa) antibody r5F9 and its humanized version h5F9 (ABT-207) promote neuroprotection and neuroregeneration in preclinical neurodegenerative disease models. However, due to its cross-reactivity to RGMc/hemojuvelin, ABT-207 causes iron accumulation in vivo, which could present a safety liability. Here we report the generation and characterization of a novel RGMa-selective anti-N-RGMa antibody elezanumab, which is currently under Phase 2 clinical evaluation in multiple disease indications. Elezanumab, a human monoclonal antibody generated by in vitro PROfusion mRNA display technology, competes with ABT-207 in binding to N-RGMa but lacks RGMc cross-reactivity with no impact on iron metabolism. It neutralizes repulsive activity of soluble RGMa in vitro and blocks membrane RGMa mediated BMP signaling. In the optic nerve crush and optic neuritis models, elezanumab promotes axonal regeneration and prevents retinal nerve fiber layer degeneration. In the spinal targeted experimental autoimmune encephalomyelitis (EAE) model, elezanumab promotes axonal regeneration and remyelination, decreases inflammatory lesion area and improves functional recovery. Finally, in the mouse cuprizone model, elezanumab reduces demyelination, which is consistent with its inhibitory effect on BMP signaling. Taken together, these preclinical data demonstrate that elezanumab has neuroregenerative and neuroprotective activities without impact on iron metabolism, thus providing a compelling rationale for its clinical development in neurodegenerative diseases.

Synthesis of new hydrazone derivatives and evaluation of their monoamine oxidase inhibitory activity.

A novel series of hydrazone derivatives were designed and synthesized. Their structures were characterized by IR, 1H NMR, 13C NMR and HR-MS spectroscopic methods. The newly synthesized compounds were evaluated for their inhibitory activity against monoamine oxidase enzymes (MAO-A and MAO-B). Compounds 2a, 2k, 4a and 4i showed significant inhibitory activity against MAO-A, with IC50 value in the range of 0.084-0.207 µM compared to reference drug moclobemide (IC50 value = 6.061 µM). These compounds (2a, 2k, 4a and 4i) were exposed to cytotoxicity tests to establish their preliminary toxicological profiles and were found to be non-cytotoxic. Moreover, the most effective compound 4i was evaluated using enzyme kinetics and docking studies to elucidate the plausible mechanisms of inhibition of MAO-A. According to enzyme kinetic studies, compound 4i was a reversible and competitive inhibitor with similar inhibition features as the substrates. Also, it was seen that this compound was settled down very properly at the active site of MAO-A enzyme by doing important interactions owing to the docking studies. Finally, ADME predictions were applied to estimate pharmacokinetic profiles of synthesized compounds. According to calculated ADME predictions, all parameters of the compounds were within the standard ranges in terms of "Rule of Five" and "Rule of Three" and it was detected that the synthesized compounds (2a-4i) have good and promising pharmacokinetic profiles.

Potential Risks of Plant Constituents in Dietary Supplements: Qualitative and Quantitative Analysis of Peganum harmala Seeds.

The free online trading of herbal mixtures useful for various purposes facilitates the circulation of dangerous herbs or plant parts. This is the case, for example, of the illegal trade in seeds of Peganum harmala (Pgh), which contain alkaloids capable of inhibiting monoamine oxidase (MAO) and are therefore used in hallucinogenic preparations, such as the psychedelic drink ayahuasca. The precise identification of these seeds and their distinction from other very similar but not dangerous seeds are necessary for forensic purposes and represents an advance in avoiding the adulteration of mixtures. In this work, we show the qualitative identification of Pgh seeds by optical and electron microscopy and the parallel development of a real-time qPCR test, which reveals, in a species-specific manner, the presence of Pgh DNA up to quantities lower than 1 pg. In addition to the species specificity and high sensitivity, the reaction accurately quantifies the presence of seeds or parts of seeds of Pgh in complex herbal mixtures, thus giving an indication of the danger or otherwise of the product.

The Intellicage system provides a reproducible and standardized method to assess behavioral changes in cuprizone-induced demyelination mouse model.

BACKGROUND: Multiple sclerosis is a neurodegenerative disorder characterized by myelin loss in the brain parenchyma. To mimic the disease, mice are fed a cuprizone-supplemented diet for 5 weeks, which leads to demyelination of white and grey matter regions, with the corpus callosum being the most susceptible to cuprizone intoxication. Although this model is highly exploited, classical behavioural tests showed inconsistent results. OBJECTIVE: In our study, we aimed to use the automated system Intellicage to phenotype the behaviour of cuprizone-fed mice. METHODS: Mice were continuously monitored during the 5 weeks of intoxication in their home cages, with minimal interference from the experimenter. Mice were assessed for spontaneous activity, fine movements, and impulsivity. RESULTS: Consistently, cuprizone-fed mice showed reduced activity and impulsivity throughout the test period. These behavioral results were confirmed by repeating the battery of behavioral tests in a second cohort of cuprizone-fed mice. Our results suggest that the behavioural phenotyping of cuprizone-fed mice using Intellicage is reproducible and sensitive enough to detect changes normally missed in standard behavioral test batteries. CONCLUSION: Using a reproducible and standardized method to assess behavioral changes in mice intoxicated with cuprizone is crucial to better understand the disease as well as the functional outcome of treatments.

Machine learning based white matter models with permeability: An experimental study in cuprizone treated in-vivo mouse model of axonal demyelination.

The intra-axonal water exchange time (τi), a parameter associated with axonal permeability, could be an important biomarker for understanding and treating demyelinating pathologies such as Multiple Sclerosis. Diffusion-Weighted MRI (DW-MRI) is sensitive to changes in permeability; however, the parameter has so far remained elusive due to the lack of general biophysical models that incorporate it. Machine learning based computational models can potentially be used to estimate such parameters. Recently, for the first time, a theoretical framework using a random forest (RF) regressor suggests that this is a promising new approach for permeability estimation. In this study, we adopt such an approach and for the first time experimentally investigate it for demyelinating pathologies through direct comparison with histology. We construct a computational model using Monte Carlo simulations and an RF regressor in order to learn a mapping between features derived from DW-MRI signals and ground truth microstructure parameters. We test our model in simulations, and find strong correlations between the predicted and ground truth parameters (intra-axonal volume fraction f: R2 =0.99, τi: R2 =0.84, intrinsic diffusivity d: R2 =0.99). We then apply the model in-vivo, on a controlled cuprizone (CPZ) mouse model of demyelination, comparing the results from two cohorts of mice, CPZ (N=8) and healthy age-matched wild-type (WT, N=8). We find that the RF model estimates sensible microstructure parameters for both groups, matching values found in literature. Furthermore, we perform histology for both groups using electron microscopy (EM), measuring the thickness of the myelin sheath as a surrogate for exchange time. Histology results show that our RF model estimates are very strongly correlated with the EM measurements (ρ = 0.98 for f, ρ = 0.82 for τi). Finally, we find a statistically significant decrease in τi in all three regions of the corpus callosum (splenium/genu/body) of the CPZ cohort (<τi>=310ms/330ms/350ms) compared to the WT group (<τi>=370ms/370ms/380ms). This is in line with our expectations that τi is lower in regions where the myelin sheath is damaged, as axonal membranes become more permeable. Overall, these results demonstrate, for the first time experimentally and in vivo, that a computational model learned from simulations can reliably estimate microstructure parameters, including the axonal permeability .

Design, Synthesis, In Vitro and In Silico Studies of New Thiazolylhydrazine-Piperazine Derivatives as Selective MAO-A Inhibitors.

Monoamine oxidase (MAO) isoenzymes are very important drug targets among neurological disorders. Herein, novel series of thiazolylhydrazine-piperazine derivatives were designed, synthesized and evaluated for their MAO-A and -B inhibitory activity. The structures of the synthesized compounds were assigned using different spectroscopic techniques such as 1H-NMR, 13C-NMR and HRMS. Moreover, the prediction of ADME (Absorption, Distribution, Metabolism, Elimination) parameters for all of the compounds were performed using in silico method. According to the enzyme inhibition results, the synthesized compounds showed the selectivity against MAO-A enzyme inhibition. Compounds 3c, 3d and 3e displayed significant MAO-A inhibition potencies. Among them, compound 3e was found to be the most effective derivative with an IC50 value of 0.057 ± 0.002 µM. Moreover, it was seen that this compound has a more potent inhibition profile than the reference inhibitors moclobemide (IC50 = 6.061 ± 0.262 µM) and clorgiline (IC50 = 0.062 ± 0.002 µM). In addition, the enzyme kinetics were performed for compound 3e and it was determined that this compound had a competitive and reversible inhibition type. Molecular modeling studies aided in the understanding of the interaction modes between this compound and MAO-A. It was found that compound 3e had significant and important binding property.

Four-week repeated dose oral toxicity study of KDS2010, a novel selective monoamine oxidase B inhibitor, in Sprague Dawley rats.

Repeated dose oral toxicity and toxicokinetic of KDS2010, a new drug for Parkinson's disease, was investigated after 4-week repeated oral administration at 30, 50, 75, or 100 mg/kg/day in rats. Body weight and body weight gain decreased in rats of both sexes in the 75 and 100 mg/kg groups, and food consumption was reduced in male rats of the 75 and 100 mg/kg male groups. Histological alterations were observed in the kidney (urothelial hyperplasia, inflammatory cell infiltration in the renal pelvis, tubular vacuolation/degeneration, basophilic tubules, and hyaline droplets in the proximal tubules) of the 75 and 100 mg/kg male groups and the 50 and 100 mg/kg female groups. The 75 and 100 mg/kg male groups showed adverse effect in the testes (degeneration/exfoliation of germ cells, seminiferous tubules atrophy) and epididymis (cellular debris, oligospermia). These changes were partially recovered after a 2-week recovery period. However, basophilic tubules and hyaline droplets in the proximal tubules in the kidney and germ cell degeneration/exfoliation in the testis were not recovered. In toxicokinetics study, systemic exposure to KDS2010 increased proportionally in both sexes by in a dose -dependent manner. In addition, repeated administration for 4 weeks led to increased tendency of systemic exposure in both sexes compared with that in Day 1. In conclusion, KDS2010 was shown to target the kidney and testis with a no-observed-adverse-effect level of 50 and 30 mg/kg/day for males and females, respectively.

Integrated Binary QSAR-Driven Virtual Screening and In Vitro Studies for Finding Novel hMAO-B-Selective Inhibitors.

The increased activity of monoamine oxidase (MAO) enzymes may lead to serious consequences since they reduce the level of neurotransmitters and are associated with severe neurodegenerative diseases. The inhibition of this enzyme, especially the B isoform, plays a vital role in the treatment of Parkinson's disease (PD). This study is aimed to find novel human MAO-B (hMAO-B) selective inhibitors. A total of 256.750 compounds from the Otava small molecules database were virtually screened gradually by employing several screening techniques for this purpose. Initially, a high-throughput virtual screening (HTVS) method was employed, and 10% of the molecules having high docking scores were subjected to binary QSAR models for further screening of their therapeutic activities against PD, Alzheimer's disease (AD), and depression as well as for their toxicity and pharmacokinetic properties. Then, enzyme selectivity of the ligands towards the A and B forms that passed through all the filters were studied using the induced-fit docking method and molecular dynamics simulations. At the end of this exhaustive research, we identified two hit molecules ligand 3 (Otava ID: 7131545) and ligand 4 (Otava ID: 7566820). Based on the in vitro results, these two compounds (ligands 3 and 4) together with ligands 1 and 2 found in our previous study showed activity at the nanomolar (nM) level, and the results indicated that these four ligands inhibit hMAO-B better than the FDA-approved drug selegiline.

Motor learning promotes remyelination via new and surviving oligodendrocytes.

Oligodendrocyte loss in neurological disease leaves axons vulnerable to damage and degeneration, and activity-dependent myelination may represent an endogenous mechanism to improve remyelination following injury. Here we report that, while learning a forelimb reach task transiently suppresses oligodendrogenesis, it subsequently increases oligodendrocyte precursor cell differentiation, oligodendrocyte generation and myelin sheath remodeling in the forelimb motor cortex. Immediately following demyelination, neurons exhibit hyperexcitability, learning is impaired and behavioral intervention provides no benefit to remyelination. However, partial remyelination restores neuronal and behavioral function, allowing learning to enhance oligodendrogenesis, remyelination of denuded axons and the ability of surviving oligodendrocytes to generate new myelin sheaths. Previously considered controversial, we show that sheath generation by mature oligodendrocytes is not only possible but also increases myelin pattern preservation following demyelination, thus presenting a new target for therapeutic interventions. Together, our findings demonstrate that precisely timed motor learning improves recovery from demyelinating injury via enhanced remyelination from new and surviving oligodendrocytes.

N-alkylpiperidine carbamates as potential anti-Alzheimer's agents.

Compounds capable of interacting with single or multiple targets involved in Alzheimer's disease (AD) pathogenesis are potential anti-Alzheimer's agents. In our aim to develop new anti-Alzheimer's agents, a series of 36 new N-alkylpiperidine carbamates was designed, synthesized and evaluated for the inhibition of cholinesterases [acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)] and monoamine oxidases [monoamine oxidase A (MAO-A and monoamine oxidase B (MAO-B)]. Four compounds are very promising: multiple AChE (IC50 = 7.31 µM), BChE (IC50 = 0.56 µM) and MAO-B (IC50 = 26.1 µM) inhibitor 10, dual AChE (IC50 = 2.25 µM) and BChE (IC50 = 0.81 µM) inhibitor 22, selective BChE (IC50 = 0.06 µM) inhibitor 13, and selective MAO-B (IC50 = 0.18 µM) inhibitor 16. Results of enzyme kinetics experiments showed that despite the carbamate group in the structure, compounds 10, 13, and 22 are reversible and non-time-dependent inhibitors of AChE and/or BChE. The resolved crystal structure of the complex of BChE with compound 13 confirmed the non-covalent mechanism of inhibition. Additionally, N-propargylpiperidine 16 is an irreversible and time-dependent inhibitor of MAO-B, while N-benzylpiperidine 10 is reversible. Additionally, compounds 10, 13, 16, and 22 should be able to cross the blood-brain barrier and are not cytotoxic to human neuronal-like SH-SY5Y and liver HepG2 cells. Finally, compounds 10 and 16 also prevent amyloid ß1-42 (Aß1-42)-induced neuronal cell death. The neuroprotective effects of compound 16 could be the result of its Aß1-42 anti-aggregation effects.

Monoamine oxidase A inhibition by toxic concentrations of metaxalone.

Context: Serotonin toxicity is a reported complication associated with both therapeutic use and overdose of metaxalone while on therapeutic doses of serotonergic drugs such as serotonin reuptake inhibitors. Monoamine oxidase A (MAO-A) inhibition by metaxalone has been proposed as the etiology of this toxicity. Metaxalone concentrations reported with cases of serotonin toxicity range from 31 to 61 mcg/ml (140-276 µM). We investigated the effect of metaxalone on MAO-A activity using an in vitro model.Methods: Metaxalone at concentrations ranging from 1.56 to 400 µM were incubated with a proprietary MAO substrate and recombinant human MAO-A for 1 h. After that, an esterase and luciferase were added and luminescence measured. Clorgyline, a known MAO-A inhibitor, was used as a positive control. Luminescence was measured using a Biotek Synergy HT microplate reader.Results: Metaxalone demonstrated significant dose-related inhibition of MAO-A activity. Four-parameter logistic regression analysis demonstrated a strong dose-response relationship at increasing concentrations.Conclusions: Our in vitro model shows that at toxic concentrations similar to those reported in case reports metaxalone shows significant MAO-A inhibition. Clinicians should be aware of this mechanism and understand the potentially lethal interactions metaxalone can have when prescribed with other serotonergic drugs and consider this as a potential cause of serotonin toxicity, especially in overdose scenarios.

New role for crinamine as a potent, safe and selective inhibitor of human monoamine oxidase B: In vitro and in silico pharmacology and modeling.

ETHNOPHARMACOLOGICAL RELEVANCE: The development of selective inhibitors of monoamine oxidase B (MAO-B) has been essential in treating Parkinson's disease. However, the apparent hepatotoxicity and drug-drug interactions of current inhibitors accentuate the need for the development of novel pharmacotherapies. Crossyne guttata (L.) D. & U. Müll-Doblies is used frequently by Rastafarian bush doctors to treat alcoholism, a disorder which is also accentuated by MAO. OBJECTIVE: The study sought to isolate, identify and characterise the biologically active constituents of C. guttata based on their ability to inhibit the MAO enzymes. MATERIALS AND METHODS: Column chromatography was used to isolate the biologically active alkaloids of C. guttata. The ability of the alkaloids to inhibit the biotransformation of 4-aminoantipyrine by the MAO enzymes was evaluated in vitro. In silico docking was conducted using AutoDock Vina server while the pharmacokinetic properties of the compounds were evaluated using SwissADME. RESULTS: Chromatographic separation of an ethanolic fraction of C. guttata yielded the alkaloids crinamine 1 and epibuphanisine 2. 1 and 2 along with structurally related alkaloids haemanthamine 3 and haemanthidine 4 were evaluated for their ability to inhibit the action of isozymes of MAO in vitro. Alkaloids effected submicromolar IC50 values against MAO-B, the most potent of which being crinamine 1 (0.014 µM) > haemanthidine 4 (0.017 µM) > epibuphanisine 2 (0.039 µM) > haemanthamine 3 (0.112 µM). Binding energies of the alkaloids correlated well with their inhibitory potential with crinamine displaying the best binding efficacy and binding energy score with MAO-B. DISCUSSION AND CONCLUSION: Crinamine and epibuphanisine exhibited potent and selective inhibitory activity towards MAO-B. After comprehensive in silico investigations encompassing robust molecular docking analysis, the drug-like attributes and safety of the alkaloids suggest the crinamine is a potentially safe drug for human application.

Intranasal delivery of SDF-1α-preconditioned bone marrow mesenchymal cells improves remyelination in the cuprizone-induced mouse model of multiple sclerosis.

Multiple sclerosis (MS) is an inflammatory and demyelinating disease of the central nervous system (CNS) that leads to disability in middle-aged individuals. High rates of apoptosis and inappropriate homing are limitations for the application of stem cells in cell therapy. Preconditioning of bone marrow mesenchymal stem cells (BMSCs) with stromal cell-derived factor 1α (SDF-1α), also called C-X-C motif chemokine 12 (CXCL12), is an approach for improving the functional features of the cells. The aim of this study was to investigate the therapeutic efficacy of intranasal delivery of SDF-1α preconditioned BMSCs in the cuprizone-induced chronically demyelinated mice model. BMSCs were isolated, cultured, and preconditioned with SDF-1α. Then, intranasal delivery of the preconditioned cells was performed in the C57BL/6 mice receiving cuprizone for 12 weeks. Animals were killed at 30 days after cell delivery. SDF-1α preconditioning increased C-X-C chemokine receptor type 4 (CXCR4) expression on the surface of BMSCs, improved survival of the cells, and decreased their apoptosis in vitro. SDF-1α preconditioning also improved CXCL12 level within the brain, and enhanced spatial learning and memory (assessed by Morris water maze [MWM]), and myelination (assessed by Luxol fast blue [LFB] and transmission electron microscopy [TEM]). In addition, preconditioning of BMSCs with SDF-1α reduced the protein expressions of glial fibrillary acidic protein and ionized calcium-binding adapter molecule (Iba-1) and increased the expressions of oligodendrocyte lineage transcription factor-2 (Olig-2) and adenomatous polyposis coli (APC), evaluated by immunofluorescence. The results showed the efficacy of intranasal delivery of SDF-1α-preconditioned BMSCs for improving remyelination in the cuprizone model of MS.

Hippocampal Neurogenesis and Neural Circuit Formation in a Cuprizone-Induced Multiple Sclerosis Mouse Model.

Cognitive impairments are key features in multiple sclerosis (MS), a progressive disorder characterized by neuroinflammation-induced demyelination in the central nervous system. To understand the neural substrates that link demyelination to cognitive deficits in MS, we investigated hippocampal neurogenesis and synaptic connectivity of adult-born neurons, which play an essential role in cognitive function. The administration and withdrawal of the combination of cuprizone and rapamycin (Cup/Rap) in C57BL/6J male mice efficiently demyelinated and remyelinated the hippocampus, respectively. In the demyelinated hippocampus, neurogenesis was nearly absent in the dentate gyrus, which was due to inhibited proliferation of neural stem cells (NSCs). Specifically, radial glia-like type 1 NSCs were shifted from a proliferative state to a mitotically-quiescent state in the demyelinated hippocampus. In addition, dendritic spine densities of adult-born neurons were significantly decreased, indicating a reduction in synaptic connections between hippocampal newborn neurons and excitatory input neurons. Concomitant with hippocampal remyelination induced by withdrawal of Cup/Rap, proliferation of type 1 NSCs and dendritic spine densities of adult-born neurons reverted to normal in the hippocampus. Our study shows that proliferation of hippocampal NSCs and synaptic connectivity of adult-born neurons are inversely correlated with the level of demyelination, providing critical insight into hippocampal neurogenesis as a potential therapeutic target to treat cognitive deficits associated with MS.SIGNIFICANCE STATEMENT To identify the neural substrates that mediate cognitive dysfunctions associated with a majority of MS patients, we investigated hippocampal neurogenesis and structural development of adult-born neurons using a Cup/Rap model, which recapitulates the hippocampal demyelination that occurs in MS patients. A shift of NSCs from a proliferatively-active state to mitotically-quiescent state dramatically decreased neurogenesis in the demyelinated hippocampus. Formation of dendritic spines on newborn neurons was also impaired following demyelination. Interestingly, the altered neurogenesis and synaptic connectivity of newborn neurons were reversed to normal levels during remyelination. Thus, our study revealed reversible genesis and synaptic connectivity of adult-born neurons between the demyelinated and remyelinated hippocampus, suggesting hippocampal neurogenesis as a potential target to normalize cognitive impairments in MS patients.

Dipropargyl substituted diphenylpyrimidines as dual inhibitors of monoamine oxidase and acetylcholinesterase.

Alzheimer's disease (AD) is a multifactorial neurological disorder involving complex pathogenesis. Single target directed drugs proved ineffective and since last few years' different pharmacological strategies including multi-targeting agents are being explored for the effective drug development for AD. A total of 19 dipropargyl substituted diphenylpyrimidines have been synthesized and evaluated for the monoamine oxidase (MAO) and acetylcholinesterase (AChE) inhibition potential. All the compounds were found to be selective and reversible inhibitors of MAO-B isoform. These compounds also displayed good AChE inhibition potential with IC50 values in low micromolar range. AVB4 was found to be the most potent MAO-B inhibitor with IC50 value of 1.49 ±â€¯0.09 µM and AVB1 was found to be the most potent AChE inhibitor with IC50 value of 1.35 ±â€¯0.03 µM. In the ROS protection inhibition studies, AVB1 and AVB4 displayed weak but interesting activity in SH-SY5Y cells. In the cytotoxicity studies involving SH-SY5Y cells, both AVB1 and AVB4 were found to be non-toxic to the tissue cells. In the molecular dynamic simulation studies of 30 ns, the potent compounds were found to be quite stable in the active site of MAO-B and AChE. The results suggested that AVB1 and AVB4 are promising dual inhibitors and have the potential to be developed as anti-Alzheimer's drug.

The Spatial and Temporal Characters of Demyelination and Remyelination in the Cuprizone Animal Model.

Multiple sclerosis (MS) is the most common central nervous system disease due to demyelination in young adults, and currently, there is no cure. Some experimental animal models were generated to mimic specific aspects of MS pathological characteristics. Among them, the cuprizone (CPZ)-induced mouse demyelination model presents heterogeneous pathologies with both focal and diffuse lesions. Considering that MS is a progressive disease, it is important to study the spatial and temporal characters of de- and remyelination in MS animal models. However, such data especially in some brain regions such as lateral septal area, fimbria of hippocampus, and hippocampus are still lacking. In this study, we investigated the alterations of myelin in these areas in parallel to the changes in corpus callosum using coronal sections. We found that the progression of demyelinating varied in different brain regions in C57BL/6J mice treated with CPZ for 1 to 5 weeks. This result suggests that each brain region has a distinct sensitivity to CPZ intoxication. Interestingly, activated microglia appeared not only in the active demyelinating areas but also in the non-myelinolysis regions. After CPZ withdrawal, significant remyelination was started in corpus callosum as early as 3 days. The completion of remyelination in the entire brain regions took 3 weeks. Our study detailed characterized the dynamics of myelin alterations and microglial status in the brain of the CPZ model. This information is valuable to facilitate further MS studies utilizing the CPZ model. Anat Rec, 302:2020-2029, 2019. © 2019 American Association for Anatomy.

Voluntary running wheel attenuates motor deterioration and brain damage in cuprizone-induced demyelination.

Growing data from human and animal studies indicate the beneficial effects of exercise on several clinical outcomes in patients with multiple sclerosis (MS), an autoimmune, demyelinating disease, suggesting that it may slow down the disease progression, by reducing brain damage. However, the mechanisms involved are still elusive. Aim of this study was to address the effects of voluntary running wheel in a toxic-demyelinating model of MS, in which demyelination and brain inflammation occur in response to cuprizone (CPZ) treatment. Mice were housed in standard or wheel-equipped cages starting from the day of CPZ or normal chow feeding for three or six weeks and evaluated for weight changes, locomotor skills and neuromuscular functions over the course of the experimental design. Biochemical, molecular biology and immunohistochemical analyses were performed. Exercise prevented early weight loss caused by CPZ, indicating improved wellness in these mice. Both neuromuscular function and motor coordination were significantly enhanced by exercise in CPZ-treated mice. Moreover, exercise induced an early protection against axonal damage and the loss of the myelin associated proteins, myelin basic protein (MBP) and 2',3'-Cyclic-nucleotide 3'-phosphodiesterase (CNPase), in the striatum and the corpus callosum, in coincidence of a strongly attenuated microglia activation in both brain areas. Further, during the late phase of the treatment, exercise in CPZ mice reduced the recruitment of new OLs compared to sedentary CPZ mice, likely due to the precocious protection against myelin damage. Overall, these results suggest that life-style interventions can be effective against the demyelinating-inflammatory processes occurring in the brains of MS patients.

Inhibitor structure-guided design and synthesis of near-infrared fluorescent probes for monoamine oxidase A (MAO-A) and its application in living cells and in vivo.

A series of near-infrared fluorescent probes based on inhibitor (clorgyline) structure-guided design were synthesized for the specific detection of MAO-A in cells and in vivo. Moreover, we have successfully used the high specificity of one of the probes to visualize MAO-A activity in zebrafish and tumor tissue for the first time.