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Weinreb O.,Rappaport Family Research Institute | Amit T.,Rappaport Family Research Institute | Bar-Am O.,Rappaport Family Research Institute | Youdim M.B.H.,Rappaport Family Research Institute | Youdim M.B.H.,Yonsei University
Current Drug Targets | Year: 2012

Ladostigil [(N-propargyl-(3R) aminoindan-5yl)-ethyl methyl carbamate] is a dual acetylcholine-butyrylcholine-esterase and brain selective monoamine oxidase (MAO)-A and -B inhibitor in vivo (with little or no MAO inhibitory effect in the liver and small intestine), intended for the treatment of dementia co-morbid with extrapyramidal disorders and depression (presently in a Phase IIb clinical study). This suggests that the drug should not cause a significant potentiation of the cardiovascular response to tyramine, thereby making it a potentially safer antidepressant than other irreversible MAO-A inhibitors. Ladostigil was shown to antagonize scopolamine-induced impairment in spatial memory, indicating that it can cause significant increases in rat brain cholinergic activity. Furthermore, ladostigil prevented gliosis and oxidative-nitrative stress and reduced the deficits in episodic and spatial memory induced by intracerebroventricular injection of streptozotocin in rats. Ladostigil was demonstrated to possess potent anti-apoptotic and neuroprotective activities in vitro and in various neurodegenerative rat models, (e.g. hippocampal damage induced by global ischemia in gerbils and cerebral oedema induced in mice by closed head injury). These neuroprotective activities involve regulation of amyloid precursor protein processing; activation of protein kinase C and mitogen-activated protein kinase signaling pathways; inhibition of neuronal death markers; prevention of the fall in mitochondrial membrane potential and up-regulation of neurotrophic factors and antioxidative activity. Recent findings demonstrated that the major metabolite of ladostigil, hydroxy-1-(R)-aminoindan has also a neuroprotective activity and thus, may contribute to the overt activity of its parent compound. This review will discuss the scientific evidence for the therapeutic potential use of ladostigil in Alzheimer's and Lewy Body diseases and the molecular signaling pathways that are considered to be involved in the biological activities of the drug. © 2012 Bentham Science Publishers.


Bar-Am O.,Rappaport Family Research Institute | Weinreb O.,Rappaport Family Research Institute | Amit T.,Rappaport Family Research Institute | Youdim M.B.H.,Rappaport Family Research Institute
Journal of Neurochemistry | Year: 2010

The anti-parkinsonian drug, rasagiline [N-propargyl-1-(R)-aminoindan; Azilect®], is a secondary cyclic benzylamine and indane derivative, which provides irreversible, potent monoamine oxidase-B (MAO-B) inhibition and possesses neuroprotective and neurorestorative activities. A prospective clinical trial has shown that rasagiline confers significant symptomatic improvement and demonstrated alterations in Parkinson's disease progression. Rasagiline is primarily metabolized by hepatic cytochrome P-450 to form its major metabolite, 1-(R)-aminoindan, a non-amphetamine, weak reversible MAO-B inhibitor compound. Recent studies indicated the potential neuroprotective effect of 1-(R)-aminoindan, suggesting that it may contribute to the overall neuroprotective and antiapoptotic effects of its parent compound, rasagiline. This review article briefly highlights the molecular mechanisms underlying the neuroprotective properties of the active metabolite of rasagiline, 1-(R)-aminoindan, supporting the valuable potential of rasagiline for disease modification. © 2010 International Society for Neurochemistry.


Weinreb O.,Rappaport Family Research Institute | Amit T.,Rappaport Family Research Institute | Mandel S.,Rappaport Family Research Institute | Kupershmidt L.,Rappaport Family Research Institute | Youdim M.B.H.,Rappaport Family Research Institute
Antioxidants and Redox Signaling | Year: 2010

Accumulating evidence suggests that many cytotoxic signals occurring in the neurodegenerative brain can initiate neuronal death processes, including oxidative stress, inflammation, and accumulation of iron at the sites of the neuronal deterioration. Neuroprotection by iron chelators has been widely recognized with respect to their ability to prevent hydroxyl radical formation in the Fenton reaction by sequestering redox-active iron. An additional neuroprotective mechanism of iron chelators is associated with their ability to upregulate or stabilize the transcriptional activator, hypoxia-inducible factor-1α (HIF-1α). HIF-1α stability within the cells is under the control of a class of iron-dependent and oxygen-sensor enzymes, HIF prolyl-4-hydroxylases (PHDs) that target HIF-1α for degradation. Thus, an emerging novel target for neuroprotection is associated with the HIF system to promote stabilization of HIF-1α and increase transcription of HIF-1-related survival genes, which have been reported to be regulated in patient's brains afflicted with diverse neurodegenerative diseases. In accordance, a new potential therapeutic strategy for neurodegenerative diseases is explored, by which iron chelators would inhibit PHDs, target the HIF-1-signaling pathway and ultimately activate HIF-1-dependent neuroprotective genes. This review discusses two interrelated approaches concerning therapy targets in neurodegeneration, sharing in common the implementation of iron chelation activity: antioxidation and HIF-1-pathway activation. © 2010 Mary Ann Liebert, Inc.


Bar-Am O.,Rappaport Family Research Institute | Amit T.,Rappaport Family Research Institute | Weinreb O.,Rappaport Family Research Institute | Youdim M.B.H.,Rappaport Family Research Institute | Mandel S.,Rappaport Family Research Institute
Journal of Alzheimer's Disease | Year: 2010

The anti-Parkinsonian, irreversible, selective monoamine oxidase (MAO)-B inhibitors, selegiline (deprenyl, (R)-N-methyl-N-(1-phenylpropan-2-yl) prop-2-yn-1-amine) and rasagiline (Azilect, N-propargyl-1(R)-aminoindan), have been proven to possess neuroprotective/neurorestorative activities in cell cultures and animal models of neurodegenerative diseases. Structure-activity studies provide evidence that neuroprotection is associated with some intrinsic pharmacological action of the propargylamine moiety in these drugs. This indication and recent therapeutic approaches, entailing new drug candidates possessing diverse pharmacological properties and acting on multiple targets, have stimulated the development of two multifunctional chimeric propargylamine-derivatives: 1) ladostigil (TV3326, [(N-propargyl-(3R) 1-(R)-aminoindan-5yl)-ethyl methyl carbamate)], which combines the pharmacophore of rasagiline, with the carbamate moiety of the cholinesterase inhibitor rivastigmine, as a potential treatment for Alzheimer's disease and Lewy body disease; and 2) M30 5-[(N-methyl-N-propargylaminomethyl)-8-hydroxyquinoline], where the propargylamine moiety of rasagiline was embedded onto the backbone of the neuroprotective and brain permeable iron chelator 8-hydroxyquinoline- derivative, VK28 as a potential treatment for various neurodegenerative disorders. Both multifunctional propargylamine-derivatives were found to possess neuroprotective and anti-apoptotic properties. An additional and new neuroprotective effect, shared by the propargylamine-derivative compounds, is related to their ability to regulate the processing of amyloid-β protein precursor (AβPP) by the non-amyloidogenic α-secretase pathway. This effect was shown to involve activation of p42/44 mitogen-activated protein kinase (MAPK) and protein kinase C (PKC) signaling pathway. This review will summarize and discuss current research, focused on the effect of propargylamine-related derivatives on the proteolytic processing of AβPP and signal transduction mechanisms. © 2010 - IOS Press and the authors.


Weinreb O.,Rappaport Family Research Institute | Bar-Am O.,Rappaport Family Research Institute | Prosolovich K.,Rappaport Family Research Institute | Amit T.,Rappaport Family Research Institute | And 2 more authors.
Antioxidants and Redox Signaling | Year: 2011

The anti-Parkinsonian, monoamine oxidase-B inhibitor drug, rasagiline (Azilect ®), is primarily metabolized by hepatic cytochrome P450 isoenzyme 1A2-mediated N-dealkylation to form its major metabolite, 1-(R)-aminoindan. The present study was undertaken to further investigate, for the first time, the possible neuroprotective effect of 1-(R)-aminoindan in two rat models of Parkinson's disease, the 6-hydroxydopamine-and lactacystin (a proteasomal inhibitor)-induced nigrostriatal degeneration. 1-(R)-aminoindan reversed behavioral asymmetry and restored striatal catecholamine levels in these two rat models and significantly protected neurons from hydrogen peroxide-induced oxidative stress. These observations indicate that 1-(R)-aminoindan may contribute to the overall neuroprotective activity of its parental compound, rasagiline. © 2011, Mary Ann Liebert, Inc.


Weinreb O.,Rappaport Family Research Institute | Amit T.,Rappaport Family Research Institute | Mandel S.,Rappaport Family Research Institute | Youdim M.B.H.,Rappaport Family Research Institute
Neurodegenerative Diseases | Year: 2012

Our novel multimodal brain-permeable iron-chelating compounds M30 and HLA20 were demonstrated to possess neuroprotective/neurorescue activities in vitro and in vivo against several insults applicable to various neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis. Neuroprotection by iron chelators has been widely recognized with respect to their ability to prevent reactive oxygen species generation in the Fenton reaction by sequestering redox-active iron. An additional neuroprotective mechanism of iron-chelating compounds is associated with their ability to regulate the transcriptional activator hypoxia-inducible factor 1 (HIF-1). HIF-1 is a 'master switch' being an important physiological response mechanism, likely enhancing neuroprotective compensatory pathways involved in many physiological processes within the brain. This mini-review will discuss the multifunctional mechanisms of action of the drugs, M30 and HLA20 in preclinical models of neurodegeneration with a specific emphasis on their ability to activate the HIF-1 signal transduction pathway. Copyright © 2011 S. Karger AG, Basel.


Kupershmidt L.,Rappaport Family Research Institute | Amit T.,Rappaport Family Research Institute | Bar-Am O.,Rappaport Family Research Institute | Youdim M.B.H.,Rappaport Family Research Institute | Weinreb O.,Rappaport Family Research Institute
Antioxidants and Redox Signaling | Year: 2012

Aims: The aim of the present study was to evaluate the therapeutic effect of the novel neuroprotective multi-target nontoxic, lipophilic, brain permeable monoamine oxidase inhibitor and iron chelating-radical scavenging drug, M30, on the neuropathology and deficits of spatial learning and memory in amyloid precursor protein (APP) and presenilin 1 (PS1) double-transgenic (Tg) Alzheimer's disease (AD) mice. Results: Here, we report that systemic treatment of APP/PS1 Tg mice with M30 for 9 months, significantly attenuated cognitive impairments in a variety of tasks of spatial learning and memory retention, working memory, learning abilities, anxiety levels, and memory for novel food and nesting behavior. Furthermore, we found that M30 reduced cerebral iron accumulation accompanied by a marked decrease in several AD-like phenotypes, including cerebral APP levels, amyloid β (Aβ) levels and plaques, phospho-APP and phospho-tau. Signaling studies revealed that M30 markedly downregulated the levels of phosphorylated cyclin-dependent kinase 5 and increased protein kinase B and glycogen synthase kinase 3β phosphorylation. Innovation: Accumulation and deposition of brain iron is central to various neuropathological processes in AD, including oxidative stress, amyloid deposition, and tau phosphorylation. Thus, the concept of iron chelation holds considerable promise as a therapeutic strategy for AD pathogenesis. Here, for the first time, we demonstrated that, when systemically administered to APP/PS1 Tg mice, our novel multifunctional iron chelating/radical scavenging compound, M30, effectively reduced Aβ accumulation and tau phosphorylation, and attenuated memory deficits. Conclusions: These findings suggest that M30 is a potential therapeutic agent for the prevention and treatment of AD. Antioxid. Redox Signal. © 2012 Mary Ann Liebert, Inc.


Weinreb O.,Rappaport Family Research Institute
Journal of neural transmission (Vienna, Austria : 1996) | Year: 2011

It is for these authors a great privilege to dedicate this review article to Moussa Youdim, who is one of the most imperative pharmacologists and pioneer investigators in the search and development of novel therapeutics for neurodegenerative diseases. 40 years ago, Moussa Youdim has started studying brain iron, catecholamine receptor and monoamine oxidase (MAO)-A and -B functions. Although Moussa Youdim succeeded in exploring the novel anti-Parkinsonian, selective MAO-B inhibitor drug, rasagiline (Azilect, Teva Pharmaceutical Co.), he did not stop searching for superior therapeutic approaches for neurodegenerative disorders. To date, Moussa Youdim and his research group are designing and synthesizing pluripotential drug candidates possessing diverse pharmacological properties that can act on multiple targets and pathological features ascribed to Parkinson's disease, Alzheimer's disease (AD) and amyotrophic lateral sclerosis. One such example is the multimodal non-toxic, brain-permeable iron-chelating compound, M30 (5-[N-methyl-N-propargylaminomethyl]-8-hydroxyquinoline), which amalgamates the propargyl moiety of rasagiline with the backbone of the potent iron chelator, VK28. This review discusses the multiple effects of several leading compounds of this series, concerning their neuroprotective/neurorestorative molecular mechanisms in vivo and in vitro, with a special focus on the pathological features ascribed to AD, including antioxidant and iron chelating activities, regulation of amyloid precursor protein and amyloid β peptide expression processing, activation of pro-survival signaling pathways and regulation of cell cycle and neurite outgrowth.


Avramovich-Tirosh Y.,Rappaport Family Research Institute | Bar-Am O.,Rappaport Family Research Institute | Amit T.,Rappaport Family Research Institute | Youdim M.B.H.,Rappaport Family Research Institute | Weinreb O.,Rappaport Family Research Institute
Current Alzheimer Research | Year: 2010

Based on a multimodal drug design paradigm, we have synthesized a multifunctional non-toxic, brain permeable iron chelator, M30, possessing the neuroprotective propargylamine moiety of the anti-Parkinsonian drug, rasagiline (Azilect) and antioxidant-iron chelator moiety of an 8-hydroxyquinoline derivative of our iron chelator, VK28. M30 was recently found to confer potential neuroprotective effects in vitro and in various preclinical neurodegenerative models and regulate the levels and processing of the Alzheimer's amyloid precursor protein and its toxic amyloidogenic derivative, Aβ. Here, we show that M30 activates the hypoxia-inducible factor (HIF)-1α signaling pathway, thus promoting HIF-1α mRNA and protein expression levels, as well as increasing transcription of HIF-1α-dependent genes, including vascular endothelial growth factor, erythropoietin, enolase-1, p21 and tyrosine hydroxylase in rat primary cortical cells. In addition, M30 increased the expression levels of the transcripts of brain derived neurotrophic factor (BDNF) and growthassociated protein-43 (GAP-43). Regarding aspects of relevance to Alzheimer's disease (AD), western blotting analysis of glycogen synthase kinase- 3β (GSK-3β) signaling pathway revealed that M30 enhanced the levels of phospho-AKT (Ser473) and phospho- GSK-3β (Ser9) and attenuated Tau phosphorylation. M30 was also shown to protect cultured cortical neurons against Aβ25-35 toxicity. All these multimodal pharmacological activities of M30 might be beneficial for its potent efficacy in the prevention and treatment of neurodegenerative conditions, such as Parkinson's disease and AD in which oxidative stress and iron-mediated toxicity are involved. © 2010 Bentham Science Publishers Ltd.


PubMed | Tel Aviv University, Rappaport Family Research Institute and Bar - Ilan University
Type: Journal Article | Journal: Nutritional neuroscience | Year: 2016

Iron deficiency (ID) induces in rats marked reduction of brain iron and dopamine D2 receptor. The resultant effects are a wide variety of changes in dopamine-mediated behaviors including thermo-regulation, motor activity, stereotyped behavior and diminished learning. Another behavioral change resulting from ID rats is an increase in the pain threshold, which is dependent on the duration and severity of ID. The results showed that peripheral administration of enkaphalines (0.1-3.0 mg/kg I.P.) potentiates ID-induced analgesia and causes a higher pain threshold, a phenomenon not observed in control rats.This effect may be associated with the known functional alteration in blood brain barrier resulting from ID. The opiate antagonists, naloxone (2 mg/kg and MIF-I (1 mg/kg), blocked the opiate-induced pain threshold potentiation in ID. Furthermore, the levels of dynorphin B and met-enkephalin are significantly increased in dopamine opiate-rich brain areas (caudate nucleus, substantia nigra, nucleus accumbens and globus pallidus) during ID. These phenomena can be reversed by placing rats on iron plus (control) diet for 24 days. It is concluded that a decrease in brain dopamine neurotransmission is associated with an increased functional level of the opiate system and that this mechanism mediates not only the analgesic effect but may also be associated with learning deficit observed in ID rats.

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