1
|
Baazaoui N, Iqbal K. Alzheimer's Disease: Challenges and a Therapeutic Opportunity to Treat It with a Neurotrophic Compound. Biomolecules 2022; 12:biom12101409. [PMID: 36291618 PMCID: PMC9599095 DOI: 10.3390/biom12101409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 11/25/2022] Open
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disease with an insidious onset and multifactorial nature. A deficit in neurogenesis and synaptic plasticity are considered the early pathological features associated with neurofibrillary tau and amyloid β pathologies and neuroinflammation. The imbalance of neurotrophic factors with an increase in FGF-2 level and a decrease in brain derived neurotrophic factor (BDNF) and neurotrophin 4 (NT-4) in the hippocampus, frontal cortex and parietal cortex and disruption of the brain micro-environment are other characteristics of AD. Neurotrophic factors are crucial in neuronal differentiation, maturation, and survival. Several attempts to use neurotrophic factors to treat AD were made, but these trials were halted due to their blood-brain barrier (BBB) impermeability, short-half-life, and severe side effects. In the present review we mainly focus on the major etiopathology features of AD and the use of a small neurotrophic and neurogenic peptide mimetic compound; P021 that was discovered in our laboratory and was found to overcome the difficulties faced in the administration of the whole neurotrophic factor proteins. We describe pre-clinical studies on P021 and its potential as a therapeutic drug for AD and related neurodegenerative disorders. Our study is limited because it focuses only on P021 and the relevant literature; a more thorough investigation is required to review studies on various therapeutic approaches and potential drugs that are emerging in the AD field.
Collapse
Affiliation(s)
- Narjes Baazaoui
- Biology Department, College of Sciences and Arts Muhayil Assir, King Khalid University, Abha 61421, Saudi Arabia
| | - Khalid Iqbal
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA
- Correspondence: ; Tel.: +1-718-494-5259; Fax: +1-718-494-1080
| |
Collapse
|
2
|
Bartesaghi R. Brain circuit pathology in Down syndrome: from neurons to neural networks. Rev Neurosci 2022; 34:365-423. [PMID: 36170842 DOI: 10.1515/revneuro-2022-0067] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 08/28/2022] [Indexed: 11/15/2022]
Abstract
Down syndrome (DS), a genetic pathology caused by triplication of chromosome 21, is characterized by brain hypotrophy and impairment of cognition starting from infancy. While studies in mouse models of DS have elucidated the major neuroanatomical and neurochemical defects of DS, comparatively fewer investigations have focused on the electrophysiology of the DS brain. Electrical activity is at the basis of brain functioning. Therefore, knowledge of the way in which brain circuits operate in DS is fundamental to understand the causes of behavioral impairment and devise targeted interventions. This review summarizes the state of the art regarding the electrical properties of the DS brain, starting from individual neurons and culminating in signal processing in whole neuronal networks. The reported evidence derives from mouse models of DS and from brain tissues and neurons derived from individuals with DS. EEG data recorded in individuals with DS are also provided as a key tool to understand the impact of brain circuit alterations on global brain activity.
Collapse
Affiliation(s)
- Renata Bartesaghi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy
| |
Collapse
|
3
|
The flavonoid 7,8-DHF fosters prenatal brain proliferation potency in a mouse model of Down syndrome. Sci Rep 2021; 11:6300. [PMID: 33737521 PMCID: PMC7973813 DOI: 10.1038/s41598-021-85284-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 02/24/2021] [Indexed: 12/17/2022] Open
Abstract
Neurogenesis impairment is a key determinant of intellectual disability in Down syndrome (DS), a genetic pathology due to triplication of chromosome 21. Since neurogenesis ceases after birth, apart in the hippocampus and olfactory bulb, the only means to tackle the problem of neurogenesis impairment in DS at its root is to intervene during gestation. A few studies in DS mouse models show that this is possible, although the drugs used may raise caveats in terms of safety. We previously found that neonatal treatment with 7,8-dihydroxyflavone (7,8-DHF), a flavonoid present in plants, restores hippocampal neurogenesis in the Ts65Dn model of DS. The goal of the current study was to establish whether prenatal treatment with 7,8-DHF improves/restores overall brain proliferation potency. Pregnant Ts65Dn females received 7,8-DHF from embryonic day 10 until delivery. On postnatal day 2 (P2) the pups were injected with BrdU and were killed after either 2 h or 52–60 days (P52–60). Evaluation of the number of proliferating (BrdU+) cells in various forebrain neurogenic niches of P2 mice showed that in treated Ts65Dn mice proliferation potency was improved or even restored in most of the examined regions, including the hippocampus. Quantification of the surviving BrdU+ cells in the dentate gyrus of P52–60 mice showed no difference between treated and untreated Ts65Dn mice. At P52–60, however, treated Ts65Dn mice exhibited a larger number of granule cells in comparison with their untreated counterparts, although their number did not reach that of euploid mice. Results show that 7,8-DHF has a widespread impact on prenatal proliferation potency in Ts65Dn mice and exerts mild long-term effects. It remains to be established whether treatment extending into the neonatal period can lead to an improvement in brain development that is retained in adulthood.
Collapse
|
4
|
Tayebati SK, Cecchi A, Martinelli I, Carboni E, Amenta F. Pharmacotherapy of Down’s Syndrome: When and Which? CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2020; 18:750-757. [DOI: 10.2174/1871527318666191114092924] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 10/19/2019] [Accepted: 10/22/2019] [Indexed: 12/15/2022]
Abstract
:
Down Syndrome (DS) is an essential genetic disease that involves many other body systems
along with cerebral functions. The postnatal approach to treat this genetic disease includes intervention
on various related disorders (e.g., heart failure, respiratory, oral, ear, and hearing disorders). However,
different proposed treatments do not significantly improve the quality of life of these subjects. Another
approach to the treatment of DS considering the possibility to intervene on the embryo was recently
introduced. As of this, the current study has reviewed different outcomes regarding DS treatment in an
animal model, namely the Ts65Dn mouse. The obtained results encouraged spending more time, efforts,
and resources in this field. Besides, various treatment strategies were tried to include genetic
modification, treatment with vasoactive intestinal peptide derivatives or fluoxetine. However, the main
obstacle to the use of these possible treatments is the ethical issues it raises. The progression of the
pregnancy in spite of awareness that DS affects the unborn and prenatal treatment of DS injured embryo
are relevant dilemmas. Thus, talented researchers should spend more efforts to improve the quality
of life for people affected by DS, which will allow probably a better approach to the ethical issues.
Collapse
Affiliation(s)
- Seyed K. Tayebati
- School of Medicinal Sciences and Health Products, University of Camerino, Camerino, Italy
| | | | - Ilenia Martinelli
- School of Medicinal Sciences and Health Products, University of Camerino, Camerino, Italy
| | - Elisa Carboni
- Regional Centre for Prenatal Diagnosis, Loreto, Italy
| | - Francesco Amenta
- School of Medicinal Sciences and Health Products, University of Camerino, Camerino, Italy
| |
Collapse
|
5
|
Haque MN, Mohibbullah M, Hong YK, Moon IS. Calotropis gigantea Promotes Neuritogenesis and Synaptogenesis through Activation of NGF-TrkA-Erk1/2 Signaling in Rat Hippocampal Neurons. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2019; 46:1861-1877. [DOI: 10.1142/s0192415x18500933] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Calotropis gigantea (L.) R. Br (Apocynaceae) (commonly known as milkweed or crown flower) is a large shrub native to temperate regions of Asia, including China, Bangladesh and India and has a long history of use in traditional medicines. In this study, we investigated the neuromodulatory effects of the ethanol extracts of C. gigantea leaves (CGE) during synaptogenesis in the late stage of neuronal development and during early stage neuritogenesis in cultured rat hippocampal neurons. Maximum neuritogenic activity was achieved at a CGE concentration of 7.5[Formula: see text][Formula: see text]g/ml. At this concentration, CGE facilitated the early development of cytoarchitecture, as evidenced by increases in morphometric parameters, such as, the numbers, lengths, and number of branches of initial neurites, axon and dendrites. During the synaptogenic stage (DIV 14), immunocytochemistry (ICC) showed that CGE upregulated synaptic vesicle 2 (SV2, a marker of axon terminals) and postsynaptic density-95 (PSD-95, a postsynaptic marker) and their colocalization. CGE upregulated nerve growth factor (NGF) and activated extracellular signal-regulated kinase 1/2 (Erk1/2), which is blocked by a TrkA-specific inhibitor suggesting the neuritogenic and synaptogenic potential of CGE was due to the activation of NGF-TrkA-Erk1/2 signaling. Moreover, UPLC of CGE did not detect stigmasterol, an active component of C. gigantea. However, the chloroform-methanol and ethyl acetate subfractions of CGE exhibited initial neuritogenic activity, suggesting that multiple active components were responsible for the neurotrophic-mimetic properties of CGE. Our data prove the neuromodulatory ability of CGE and provide a means of identifying new active phytochemicals with potential nootropic, preventative or therapeutic effects on the human brain.
Collapse
Affiliation(s)
- Md Nazmul Haque
- Department of Anatomy, Dongguk University Graduate School of Medicine, Gyeongju 38066, Republic of Korea
| | - Md Mohibbullah
- Department of Biotechnology, Pukyong National University, Namku, Busan 48513, Republic of Korea
- Department of Fisheries and Marine Bioscience, Bangabandhu Sheikh Mujibur Rahman Science and Technology University, Gopalgonj-8100, Bangladesh
| | - Yong-Ki Hong
- Department of Biotechnology, Pukyong National University, Namku, Busan 48513, Republic of Korea
| | - Il Soo Moon
- Department of Anatomy, Dongguk University Graduate School of Medicine, Gyeongju 38066, Republic of Korea
| |
Collapse
|
6
|
Herault Y, Delabar JM, Fisher EMC, Tybulewicz VLJ, Yu E, Brault V. Rodent models in Down syndrome research: impact and future opportunities. Dis Model Mech 2018; 10:1165-1186. [PMID: 28993310 PMCID: PMC5665454 DOI: 10.1242/dmm.029728] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Down syndrome is caused by trisomy of chromosome 21. To date, a multiplicity of mouse models with Down-syndrome-related features has been developed to understand this complex human chromosomal disorder. These mouse models have been important for determining genotype-phenotype relationships and identification of dosage-sensitive genes involved in the pathophysiology of the condition, and in exploring the impact of the additional chromosome on the whole genome. Mouse models of Down syndrome have also been used to test therapeutic strategies. Here, we provide an overview of research in the last 15 years dedicated to the development and application of rodent models for Down syndrome. We also speculate on possible and probable future directions of research in this fast-moving field. As our understanding of the syndrome improves and genome engineering technologies evolve, it is necessary to coordinate efforts to make all Down syndrome models available to the community, to test therapeutics in models that replicate the whole trisomy and design new animal models to promote further discovery of potential therapeutic targets. Summary: Mouse models have boosted therapeutic options for Down syndrome, and improved models are being developed to better understand the pathophysiology of this genetic condition.
Collapse
Affiliation(s)
- Yann Herault
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, 1 rue Laurent Fries, 67404 Illkirch, France .,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France.,T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris
| | - Jean M Delabar
- T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris.,Université Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, UMR8251, CNRS, 75205 Paris, France.,INSERM U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et la Moelle épinière, ICM, 75013 Paris, France.,Brain and Spine Institute (ICM) CNRS UMR7225, INSERM UMRS 975, 75013 Paris, France
| | - Elizabeth M C Fisher
- T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris.,Department of Neurodegenerative Disease, Institute of Neurology, University College London, London, WC1N 3BG, UK.,LonDownS Consortium, London, W1T 7NF UK
| | - Victor L J Tybulewicz
- T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris.,LonDownS Consortium, London, W1T 7NF UK.,The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.,Department of Medicine, Imperial College, London, SW7 2AZ, UK
| | - Eugene Yu
- T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris.,The Children's Guild Foundation Down Syndrome Research Program, Department of Cancer Genetics and Genetics Program, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.,Department of Cellular and Molecular Biology, Roswell Park Division of Graduate School, Genetics, Genomics and Bioinformatics Program, State University of New York at Buffalo, Buffalo, NY 14263, USA
| | - Veronique Brault
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, 1 rue Laurent Fries, 67404 Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
| |
Collapse
|
7
|
Baazaoui N, Iqbal K. Prevention of dendritic and synaptic deficits and cognitive impairment with a neurotrophic compound. ALZHEIMERS RESEARCH & THERAPY 2017; 9:45. [PMID: 28655344 PMCID: PMC5488423 DOI: 10.1186/s13195-017-0273-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 06/02/2017] [Indexed: 01/09/2023]
Abstract
Background The use of neurotrophic factors to treat Alzheimer’s disease (AD) is hindered by their blood–brain barrier impermeability, short half-life, and severe side effects. Peptide 021 (P021) is a neurotrophic/neurogenic tetra-peptide that was derived from the most active region of the ciliary neurotrophic factor (CNTF) by epitope mapping. Admantylated glycine was added to its C-terminal to increase its blood–brain barrier permeability and decrease its degradation by exopeptidases to make it druggable. Here, we report on the preventive effect of P021 in 3 × Tg-AD, a transgenic mouse model of AD. Methods P021 was administered in the diet at 3 months, i.e., 6–9 months before any overt amyloid beta (Aβ) or tau pathology, and during the period of synaptic compensation, and was continued until 21 months in 3 × Tg-AD mice. The 3 × Tg-AD mice and wild-type (WT) mice were treated identically but with a vehicle-only diet serving as controls. The effects of P021 on neurogenesis, dendritic and synaptic markers, and cognitive performance were investigated. Results We found that P021 treatment was able to rescue dendritic and synaptic deficits, boost neurogenesis, and reverse cognitive impairment in 3 × Tg-AD mice. Conclusions Availability of appropriate neurotrophic support during the period of synaptic compensation can prevent synaptic deficit and cognitive impairment, and P021 is a promising neurotrophic compound for this purpose. Electronic supplementary material The online version of this article (doi:10.1186/s13195-017-0273-7) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Narjes Baazaoui
- Department of Neurochemistry, IngeGrundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY, 10314, USA.,Graduate Program in Biology (Neuroscience), College of Staten Island (CSI), City University of New York (CUNY) Graduate Center, 365 Fifth Avenue, New York, NY, 10016-4309, USA
| | - Khalid Iqbal
- Department of Neurochemistry, IngeGrundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY, 10314, USA.
| |
Collapse
|
8
|
Kazim SF, Blanchard J, Bianchi R, Iqbal K. Early neurotrophic pharmacotherapy rescues developmental delay and Alzheimer's-like memory deficits in the Ts65Dn mouse model of Down syndrome. Sci Rep 2017; 7:45561. [PMID: 28368015 PMCID: PMC5377379 DOI: 10.1038/srep45561] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 02/27/2017] [Indexed: 12/21/2022] Open
Abstract
Down syndrome (DS), caused by trisomy 21, is the most common genetic cause of intellectual disability and is associated with a greatly increased risk of early-onset Alzheimer’s disease (AD). The Ts65Dn mouse model of DS exhibits several key features of the disease including developmental delay and AD-like cognitive impairment. Accumulating evidence suggests that impairments in early brain development caused by trisomy 21 contribute significantly to memory deficits in adult life in DS. Prenatal genetic testing to diagnose DS in utero, provides the novel opportunity to initiate early pharmacological treatment to target this critical period of brain development. Here, we report that prenatal to early postnatal treatment with a ciliary neurotrophic factor (CNTF) small-molecule peptide mimetic, Peptide 021 (P021), rescued developmental delay in pups and AD-like hippocampus-dependent memory impairments in adult life in Ts65Dn mice. Furthermore, this treatment prevented pre-synaptic protein deficit, decreased glycogen synthase kinase-3beta (GSK3β) activity, and increased levels of synaptic plasticity markers including brain derived neurotrophic factor (BNDF) and phosphorylated CREB, both in young (3-week-old) and adult (~ 7-month-old) Ts65Dn mice. These findings provide novel evidence that providing neurotrophic support during early brain development can prevent developmental delay and AD-like memory impairments in a DS mouse model.
Collapse
Affiliation(s)
- Syed Faraz Kazim
- Department of Neurochemistry, and SUNY Downstate/NYSIBR Center for Developmental Neuroscience, New York State Institute for Basic Research (NYSIBR), Staten Island, NY 10314, USA.,The Robert F. Furchgott Center for Neural and Behavioral Science, and Department of Physiology and Pharmacology, State University of New York (SUNY) Downstate Medical Center, Brooklyn, NY 11203, USA.,Graduate Program in Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY 11203, USA
| | - Julie Blanchard
- Department of Neurochemistry, and SUNY Downstate/NYSIBR Center for Developmental Neuroscience, New York State Institute for Basic Research (NYSIBR), Staten Island, NY 10314, USA
| | - Riccardo Bianchi
- The Robert F. Furchgott Center for Neural and Behavioral Science, and Department of Physiology and Pharmacology, State University of New York (SUNY) Downstate Medical Center, Brooklyn, NY 11203, USA
| | - Khalid Iqbal
- Department of Neurochemistry, and SUNY Downstate/NYSIBR Center for Developmental Neuroscience, New York State Institute for Basic Research (NYSIBR), Staten Island, NY 10314, USA
| |
Collapse
|
9
|
Kazim SF, Iqbal K. Neurotrophic factor small-molecule mimetics mediated neuroregeneration and synaptic repair: emerging therapeutic modality for Alzheimer's disease. Mol Neurodegener 2016; 11:50. [PMID: 27400746 PMCID: PMC4940708 DOI: 10.1186/s13024-016-0119-y] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Accepted: 07/02/2016] [Indexed: 11/10/2022] Open
Abstract
Alzheimer's disease (AD) is an incurable and debilitating chronic progressive neurodegenerative disorder which is the leading cause of dementia worldwide. AD is a heterogeneous and multifactorial disorder, histopathologically characterized by the presence of amyloid β (Aβ) plaques and neurofibrillary tangles composed of Aβ peptides and abnormally hyperphosphorylated tau protein, respectively. Independent of the various etiopathogenic mechanisms, neurodegeneration is a final common outcome of AD neuropathology. Synaptic loss is a better correlate of cognitive impairment in AD than Aβ or tau pathologies. Thus a highly promising therapeutic strategy for AD is to shift the balance from neurodegeneration to neuroregeneration and synaptic repair. Neurotrophic factors, by virtue of their neurogenic and neurotrophic activities, have potential for the treatment of AD. However, the clinical therapeutic usage of recombinant neurotrophic factors is limited because of the insurmountable hurdles of unfavorable pharmacokinetic properties, poor blood-brain barrier (BBB) permeability, and severe adverse effects. Neurotrophic factor small-molecule mimetics, in this context, represent a potential strategy to overcome these short comings, and have shown promise in preclinical studies. Neurotrophic factor small-molecule mimetics have been the focus of intense research in recent years for AD drug development. Here, we review the relevant literature regarding the therapeutic beneficial effect of neurotrophic factors in AD, and then discuss the recent status of research regarding the neurotrophic factor small-molecule mimetics as therapeutic candidates for AD. Lastly, we summarize the preclinical studies with a ciliary neurotrophic factor (CNTF) small-molecule peptide mimetic, Peptide 021 (P021). P021 is a neurogenic and neurotrophic compound which enhances dentate gyrus neurogenesis and memory processes via inhibiting leukemia inhibitory factor (LIF) signaling pathway and increasing brain-derived neurotrophic factor (BDNF) expression. It robustly inhibits tau abnormal hyperphosphorylation via increased BDNF mediated decrease in glycogen synthase kinase-3β (GSK-3β, major tau kinase) activity. P021 is a small molecular weight, BBB permeable compound with suitable pharmacokinetics for oral administration, and without adverse effects associated with native CNTF or BDNF molecule. P021 has shown beneficial therapeutic effect in several preclinical studies and has emerged as a highly promising compound for AD drug development.
Collapse
Affiliation(s)
- Syed Faraz Kazim
- />Department of Neurochemistry, and SUNY Downstate/NYSIBR Program in Developmental Neuroscience, New York State Institute for Basic Research (NYSIBR), 1050 Forest Hill Road, Staten Island, NY 10314 USA
- />Graduate Program in Neural and Behavioral Science, and Department of Physiology and Pharmacology, State University of New York (SUNY) Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203 USA
| | - Khalid Iqbal
- />Department of Neurochemistry, and SUNY Downstate/NYSIBR Program in Developmental Neuroscience, New York State Institute for Basic Research (NYSIBR), 1050 Forest Hill Road, Staten Island, NY 10314 USA
| |
Collapse
|
10
|
|
11
|
Stagni F, Giacomini A, Guidi S, Ciani E, Bartesaghi R. Timing of therapies for Down syndrome: the sooner, the better. Front Behav Neurosci 2015; 9:265. [PMID: 26500515 PMCID: PMC4594009 DOI: 10.3389/fnbeh.2015.00265] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 09/15/2015] [Indexed: 11/13/2022] Open
Abstract
Intellectual disability (ID) is the unavoidable hallmark of Down syndrome (DS), with a heavy impact on public health. Accumulating evidence shows that DS is characterized by numerous neurodevelopmental alterations among which the reduction of neurogenesis, dendritic hypotrophy and connectivity alterations appear to play a particularly prominent role. Although the mechanisms whereby gene triplication impairs brain development in DS have not been fully clarified, it is theoretically possible to correct trisomy-dependent defects with targeted pharmacotherapies. This review summarizes what we know about the effects of pharmacotherapies during different life stages in mouse models of DS. Since brain alterations in DS start to be present prenatally, the prenatal period represents an optimum window of opportunity for therapeutic interventions. Importantly, recent studies clearly show that treatment during the prenatal period can rescue overall brain development and behavior and that this effect outlasts treatment cessation. Although late therapies are unlikely to exert drastic changes in the brain, they may have an impact on the hippocampus, a brain region where neurogenesis continues throughout life. Indeed, treatment at adult life stages improves or even rescues hippocampal neurogenesis and connectivity and hippocampal-dependent learning and memory, although the duration of these effects still remains, in the majority of cases, a matter of investigation. The exciting discovery that trisomy-linked brain abnormalities can be prevented with early interventions gives us reason to believe that treatments during pregnancy may rescue brain development in fetuses with DS. For this reason we deem it extremely important to expedite the discovery of additional therapies practicable in humans in order to identify the best treatment/s in terms of efficacy and paucity of side effects. Prompt achievement of this goal is the big challenge for the scientific community of researchers interested in DS.
Collapse
Affiliation(s)
| | | | | | | | - Renata Bartesaghi
- Department of Biomedical and Neuromotor Sciences, University of BolognaBologna, Italy
| |
Collapse
|
12
|
Chohan MO, Bragina O, Kazim SF, Statom G, Baazaoui N, Bragin D, Iqbal K, Nemoto E, Yonas H. Enhancement of neurogenesis and memory by a neurotrophic peptide in mild to moderate traumatic brain injury. Neurosurgery 2015; 76:201-14; discussion 214-5. [PMID: 25255260 DOI: 10.1227/neu.0000000000000577] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Traumatic brain injury (TBI) is a risk factor for Alzheimer disease (AD), a neurocognitive disorder with similar cellular abnormalities. We recently discovered a small molecule (Peptide 6) corresponding to an active region of human ciliary neurotrophic factor, with neurogenic and neurotrophic properties in mouse models of AD and Down syndrome. OBJECTIVE To describe hippocampal abnormalities in a mouse model of mild to moderate TBI and their reversal by Peptide 6. METHODS TBI was induced in adult C57Bl6 mice using controlled cortical impact with 1.5 mm of cortical penetration. The animals were treated with 50 nmol/d of Peptide 6 or saline solution for 30 days. Dentate gyrus neurogenesis, dendritic and synaptic density, and AD biomarkers were quantitatively analyzed, and behavioral tests were performed. RESULTS Ipsilateral neuronal loss in CA1 and the parietal cortex and increase in Alzheimer-type hyperphosphorylated tau and A-β were seen in TBI mice. Compared with saline solution, Peptide 6 treatment increased the number of newborn neurons, but not uncommitted progenitor cells, in dentate gyrus by 80%. Peptide 6 treatment also reversed TBI-induced dendritic and synaptic density loss while increasing activity in tri-synaptic hippocampal circuitry, ultimately leading to improvement in memory recall on behavioral testing. CONCLUSION Long-term treatment with Peptide 6 enhances the pool of newborn neurons in the dentate gyrus, prevents neuronal loss in CA1 and parietal cortex, preserves the dendritic and synaptic architecture in the hippocampus, and improves performance on a hippocampus-dependent memory task in TBI mice. These findings necessitate further inquiry into the therapeutic potential of small molecules based on neurotrophic factors.
Collapse
Affiliation(s)
- Muhammad Omar Chohan
- *Department of Neurosurgery, University of New Mexico Hospital, Albuquerque, New Mexico; ‡Department of Neurochemistry, Inge Grundke-Iqbal Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York; §Neural and Behavioral Science Graduate Program, State University of New York (SUNY) Downstate Medical Center, Brooklyn, New York
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Kazim SF, Cardenas-Aguayo MDC, Arif M, Blanchard J, Fayyaz F, Grundke-Iqbal I, Iqbal K. Sera from children with autism induce autistic features which can be rescued with a CNTF small peptide mimetic in rats. PLoS One 2015; 10:e0118627. [PMID: 25769033 PMCID: PMC4359103 DOI: 10.1371/journal.pone.0118627] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 01/21/2015] [Indexed: 12/29/2022] Open
Abstract
Autism is a neurodevelopmental disorder characterized clinically by impairments in social interaction and verbal and non-verbal communication skills as well as restricted interests and repetitive behavior. It has been hypothesized that altered brain environment including an imbalance in neurotrophic support during early development contributes to the pathophysiology of autism. Here we report that sera from children with autism which exhibited abnormal levels of various neurotrophic factors induced cell death and oxidative stress in mouse primary cultured cortical neurons. The effects of sera from autistic children were rescued by pre-treatment with a ciliary neurotrophic factor (CNTF) small peptide mimetic, Peptide 6 (P6), which was previously shown to exert its neuroprotective effect by modulating CNTF/JAK/STAT pathway and LIF signaling and by enhancing brain derived neurotrophic factor (BDNF) expression. Similar neurotoxic effects and neuroinflammation were observed in young Wistar rats injected intracerebroventricularly with autism sera within hours after birth. The autism sera injected rats demonstrated developmental delay and deficits in social communication, interaction, and novelty. Both the neurobiological changes and the behavioral autistic phenotype were ameliorated by P6 treatment. These findings implicate the involvement of neurotrophic imbalance during early brain development in the pathophysiology of autism and a proof of principle of P6 as a potential therapeutic strategy for autism.
Collapse
Affiliation(s)
- Syed Faraz Kazim
- Inge Grundke-Iqbal Research Floor, Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities (NYSIBR), Staten Island, New York, United States of America
- Neural and Behavioral Science Graduate Program, State University of New York (SUNY) Downstate Medical Center, Brooklyn, New York, United States of America
- SUNY Downstate/NYSIBR Center for Developmental Neuroscience (CDN), Staten Island, New York, United States of America
| | - Maria del Carmen Cardenas-Aguayo
- Inge Grundke-Iqbal Research Floor, Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities (NYSIBR), Staten Island, New York, United States of America
| | - Mohammad Arif
- Inge Grundke-Iqbal Research Floor, Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities (NYSIBR), Staten Island, New York, United States of America
| | - Julie Blanchard
- Inge Grundke-Iqbal Research Floor, Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities (NYSIBR), Staten Island, New York, United States of America
| | - Fatima Fayyaz
- Inge Grundke-Iqbal Research Floor, Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities (NYSIBR), Staten Island, New York, United States of America
| | - Inge Grundke-Iqbal
- Inge Grundke-Iqbal Research Floor, Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities (NYSIBR), Staten Island, New York, United States of America
| | - Khalid Iqbal
- Inge Grundke-Iqbal Research Floor, Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities (NYSIBR), Staten Island, New York, United States of America
- SUNY Downstate/NYSIBR Center for Developmental Neuroscience (CDN), Staten Island, New York, United States of America
- * E-mail:
| |
Collapse
|
14
|
Gardiner KJ. Pharmacological approaches to improving cognitive function in Down syndrome: current status and considerations. Drug Des Devel Ther 2014; 9:103-25. [PMID: 25552901 PMCID: PMC4277121 DOI: 10.2147/dddt.s51476] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Down syndrome (DS), also known as trisomy 21, is the most common genetic cause of intellectual disability (ID). Although ID can be mild, the average intelligence quotient is in the range of 40-50. All individuals with DS will also develop the neuropathology of Alzheimer's disease (AD) by the age of 30-40 years, and approximately half will display an AD-like dementia by the age of 60 years. DS is caused by an extra copy of the long arm of human chromosome 21 (Hsa21) and the consequent elevated levels of expression, due to dosage, of trisomic genes. Despite a worldwide incidence of one in 700-1,000 live births, there are currently no pharmacological treatments available for ID or AD in DS. However, over the last several years, very promising results have been obtained with a mouse model of DS, the Ts65Dn. A diverse array of drugs has been shown to rescue, or partially rescue, DS-relevant deficits in learning and memory and abnormalities in cellular and electrophysiological features seen in the Ts65Dn. These results suggest that some level of amelioration or prevention of cognitive deficits in people with DS may be possible. Here, we review information from the preclinical evaluations in the Ts65Dn, how drugs were selected, how efficacy was judged, and how outcomes differ, or not, among studies. We also summarize the current state of human clinical trials for ID and AD in DS. Lastly, we describe the genetic limitations of the Ts65Dn as a model of DS, and in the preclinical testing of pharmacotherapeutics, and suggest additional targets to be considered for potential pharmacotherapies.
Collapse
Affiliation(s)
- Katheleen J Gardiner
- Linda Crnic Institute for Down Syndrome, Department of Pediatrics, Department of Biochemistry and Molecular Genetics, Human Medical Genetics and Genomics Program, Neuroscience Program, University of Colorado School of Medicine, Aurora, CO, USA
| |
Collapse
|
15
|
Hartley D, Blumenthal T, Carrillo M, DiPaolo G, Esralew L, Gardiner K, Granholm AC, Iqbal K, Krams M, Lemere C, Lott I, Mobley W, Ness S, Nixon R, Potter H, Reeves R, Sabbagh M, Silverman W, Tycko B, Whitten M, Wisniewski T. Down syndrome and Alzheimer's disease: Common pathways, common goals. Alzheimers Dement 2014; 11:700-9. [PMID: 25510383 DOI: 10.1016/j.jalz.2014.10.007] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Revised: 08/26/2014] [Accepted: 10/02/2014] [Indexed: 12/17/2022]
Abstract
In the United States, estimates indicate there are between 250,000 and 400,000 individuals with Down syndrome (DS), and nearly all will develop Alzheimer's disease (AD) pathology starting in their 30s. With the current lifespan being 55 to 60 years, approximately 70% will develop dementia, and if their life expectancy continues to increase, the number of individuals developing AD will concomitantly increase. Pathogenic and mechanistic links between DS and Alzheimer's prompted the Alzheimer's Association to partner with the Linda Crnic Institute for Down Syndrome and the Global Down Syndrome Foundation at a workshop of AD and DS experts to discuss similarities and differences, challenges, and future directions for this field. The workshop articulated a set of research priorities: (1) target identification and drug development, (2) clinical and pathological staging, (3) cognitive assessment and clinical trials, and (4) partnerships and collaborations with the ultimate goal to deliver effective disease-modifying treatments.
Collapse
Affiliation(s)
- Dean Hartley
- Medical and Scientific Relations, Alzheimer's Association, Chicago, IL, USA.
| | - Thomas Blumenthal
- Linda Crnic Institute for Down Syndrome, University of Colorado, Aurora, CO, USA; Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Maria Carrillo
- Medical and Scientific Relations, Alzheimer's Association, Chicago, IL, USA
| | - Gilbert DiPaolo
- Department of Pathology and Cell Biology, Columbia University Medical Center and The Taub Institute for Research on Alzheimer's Disease and The Aging Brain, New York, NY, USA
| | - Lucille Esralew
- Department of Behavioral Health, Trinitas Regional Medical Center, Elizabeth, NJ, USA
| | - Katheleen Gardiner
- Linda Crnic Institute for Down Syndrome, University of Colorado, Aurora, CO, USA; Department of Pediatrics, University of Colorado, Denver, CO, USA
| | - Ann-Charlotte Granholm
- Department of Neuroscience and the Center on Aging, Medical University of South Carolina, Columbia, SC, USA
| | - Khalid Iqbal
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, New York, NY, USA
| | | | - Cynthia Lemere
- Department of Neurology and the Anne Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ira Lott
- Department of Pediatrics, University of California, Irvine, CA, USA
| | - William Mobley
- Department of Neurosciences, University of California, San Diego, CA, USA
| | - Seth Ness
- Janssen Research & Development, Raritan, NJ, USA
| | - Ralph Nixon
- Department of Psychiatry and Cell Biology, New York University, Langone Medical Center, New York, NY, USA
| | - Huntington Potter
- Linda Crnic Institute for Down Syndrome, University of Colorado, Aurora, CO, USA; Department of Neurology, University of Colorado, Denver, CO, USA
| | - Roger Reeves
- Department of Physiology, McKusick-Nathans Institute for Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Marwan Sabbagh
- Banner Sun Health Research Institute, Banner Health, Sun City, AZ, USA
| | - Wayne Silverman
- Department of Behavioral Psychology, Kennedy Krieger Institute, Baltimore, MD, USA; Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Benjamin Tycko
- Department of Pathology and Cell Biology, Columbia University Medical Center and The Taub Institute for Research on Alzheimer's Disease and The Aging Brain, New York, NY, USA
| | | | - Thomas Wisniewski
- Department of Neurology, Pathology, and Psychiatry, New York University, Langone Medical Center, New York, NY, USA
| |
Collapse
|
16
|
Wang X, Yang Z, Sun Y, Zhou H, Chu G, Zhang J, Meng X. Ethanol Activation of PKA Mediates Single-Minded 2 Expression in Neuronal Cells. Mol Neurobiol 2014; 52:1234-1244. [PMID: 25319570 DOI: 10.1007/s12035-014-8924-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 10/06/2014] [Indexed: 10/24/2022]
Abstract
Prenatal ethanol exposure can cause extensive apoptotic neurodegeneration throughout the developing central nervous system (CNS), which results in cognitive deficits and memory decline. However, the underlying mechanisms need further study. Single-minded 2 (Sim2), a transcriptional repressor, is reportedly involved in diseases that impair learning and memory, such as Down syndrome (DS) and Alzheimer's disease. It is still unknown whether Sim2 is involved in regulating ethanol-mediated neuronal injury that might ultimately lead to neuronal dysfunction and subsequent learning and memory deficits. To study the effects of ethanol on Sim2 expression and neuronal injury, we used animal models and cell culture experiments. Our results indicated that in SH-SY5Y cells, ethanol exposure increased Sim2 expression and levels of cleaved caspase 3, which is a marker for cells undergoing apoptosis. Silencing Sim2 expression attenuated caspase 3 activation and cellular apoptosis. We also found that protein kinase A (PKA) activation induced Sim2 expression, as did ethanol. Inhibiting the PKA signaling pathway with H-89 decreased Sim2 expression and cleavage of caspase 3 that was induced by ethanol in vivo and in vitro. We further found that PKA regulated Sim2 expression at the transcriptional level. These results demonstrate that ethanol leads to increased Sim2 expression via the PKA pathway, ultimately resulting in apoptotic cell death.
Collapse
Affiliation(s)
- Xiaolan Wang
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Zhihua Yang
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yinan Sun
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Hanjing Zhou
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Guangpin Chu
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Jing Zhang
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xianfang Meng
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China. .,The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, China.
| |
Collapse
|
17
|
Iqbal K, Kazim SF, Bolognin S, Blanchard J. Shifting balance from neurodegeneration to regeneration of the brain: a novel therapeutic approach to Alzheimer's disease and related neurodegenerative conditions. Neural Regen Res 2014; 9:1518-9. [PMID: 25317168 PMCID: PMC4192968 DOI: 10.4103/1673-5374.139477] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2014] [Indexed: 12/01/2022] Open
Affiliation(s)
- Khalid Iqbal
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Syed Faraz Kazim
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Silvia Bolognin
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Julie Blanchard
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| |
Collapse
|
18
|
Alldred MJ, Lee SH, Petkova E, Ginsberg SD. Expression profile analysis of vulnerable CA1 pyramidal neurons in young-Middle-Aged Ts65Dn mice. J Comp Neurol 2014; 523:61-74. [PMID: 25131634 DOI: 10.1002/cne.23663] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 08/07/2014] [Accepted: 08/07/2014] [Indexed: 12/19/2022]
Abstract
Down syndrome (DS) is the most prevalent cause of intellectual disability (ID). Individuals with DS show a variety of cognitive deficits, most notably in hippocampal learning and memory, and display pathological hallmarks of Alzheimer's disease (AD), with neurodegeneration of cholinergic basal forebrain (CBF) neurons. Elucidation of the molecular and cellular underpinnings of neuropathology has been assessed via gene expression analysis in a relevant animal model, termed the Ts65Dn mouse. The Ts65Dn mouse is a segmental trisomy model of DS that mimics DS/AD pathology, notably age-related cognitive dysfunction and degeneration of basal forebrain cholinergic neurons (BFCNs). To determine expression level changes, molecular fingerprinting of cornu ammonis 1 (CA1) pyramidal neurons was performed in adult (4-9 month-old) Ts65Dn mice, at the initiation of BFCN degeneration. To quantitate transcriptomic changes during this early time period, laser capture microdissection (LCM), terminal continuation (TC) RNA amplification, custom-designed microarray analysis, and subsequent validation of individual transcripts by qPCR and protein analysis via immunoblotting was performed. The results indicate significant alterations within CA1 pyramidal neurons of Ts65Dn mice compared with normal disomic (2N) littermates, notably in the downregulation of neurotrophins and their cognate neurotrophin receptors among other classes of transcripts relevant to neurodegeneration. The results of this single-population gene expression analysis at the time of septohippocampal deficits in a trisomic mouse model shed light on a vulnerable circuit that may cause the AD-like pathology invariably seen in DS that could help to identify mechanisms of degeneration, and provide novel gene targets for therapeutic interventions. J. Comp. Neurol. 523:61-74, 2015. © 2014 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Melissa J Alldred
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, New York, 10962; Department of Psychiatry, New York University Langone Medical Center, New York, New York, 10016
| | | | | | | |
Collapse
|
19
|
Disease modifying effect of chronic oral treatment with a neurotrophic peptidergic compound in a triple transgenic mouse model of Alzheimer's disease. Neurobiol Dis 2014; 71:110-30. [PMID: 25046994 DOI: 10.1016/j.nbd.2014.07.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 05/28/2014] [Accepted: 07/08/2014] [Indexed: 12/16/2022] Open
Abstract
Besides the presence of amyloid beta (Aβ) plaques and neurofibrillary tangles, neurogenesis and synaptic plasticity are markedly impaired in Alzheimer's disease (AD) possibly contributing to cognitive impairment. In this context, neurotrophic factors serve as a promising therapeutic approach via utilization of regenerative capacity of brain to shift the balance from neurodegeneration to neural regeneration. However, besides more conventional "bystander" effect, to what extent can neurotrophic compounds affect underlying AD pathology remains questionable. Here we investigated the effect of chronic oral treatment with a ciliary neurotrophic factor (CNTF) derived peptidergic compound, P021 (Ac-DGGL(A)G-NH2), on disease pathology both at moderate and severe stages in a transgenic mouse model of AD. 3xTg-AD and wild type female mice were treated for 12months with P021 or vehicle diet starting at 9-10months of age. A significant reduction in abnormal hyperphosphorylation and accumulation of tau at known major AD neurofibrillary pathology associated sites was observed. The effect of P021 on Aβ pathology was limited to a significant decrease in soluble Aβ levels and a trend towards reduction in Aβ plaque load in CA1 region of hippocampus, consistent with reduction in Aβ generation and not clearance. This disease modifying effect was probably via increased brain derived neurotrophic factor (BDNF) expression mediated decrease in glycogen synthase kinase-3-β (GSK3β) activity we found in P021 treated 3xTg-AD mice. P021 treatment also rescued deficits in cognition, neurogenesis, and synaptic plasticity in 3xTg-AD mice. These findings demonstrate the potential of the neurotrophic peptide mimetic as a disease modifying therapy for AD.
Collapse
|
20
|
Bolognin S, Buffelli M, Puoliväli J, Iqbal K. Rescue of cognitive-aging by administration of a neurogenic and/or neurotrophic compound. Neurobiol Aging 2014; 35:2134-46. [PMID: 24702821 DOI: 10.1016/j.neurobiolaging.2014.02.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 02/18/2014] [Accepted: 02/26/2014] [Indexed: 10/25/2022]
Abstract
Aging is characterized by a progressive decline of cognitive performance, which has been partially attributed to structural and functional alterations of hippocampus. Importantly, aging is the major risk factor for the development of neurodegenerative diseases, especially Alzheimer's disease. An important therapeutic approach to counteract the age-associated memory dysfunctions is to maintain an appropriate microenvironment for successful neurogenesis and synaptic plasticity. In this study, we show that chronic oral administration of peptide 021 (P021), a small peptidergic neurotrophic compound derived from the ciliary neurotrophic factor, significantly reduced the age-dependent decline in learning and memory in 22 to 24-month-old Fisher rats. Treatment with P021 inhibited the deficit in neurogenesis in the aged rats and increased the expression of brain derived neurotrophic factor. Furthermore, P021 restored synaptic deficits both in the cortex and the hippocampus. In vivo magnetic resonance spectroscopy revealed age-dependent alterations in hippocampal content of several metabolites. Remarkably, P021 was effective in significantly reducing myoinositol (INS) concentration, which was increased in aged compared with young rats. These findings suggest that stimulating endogenous neuroprotective mechanisms is a potential therapeutic approach to cognitive aging, Alzheimer's disease, and associated neurodegenerative disorders and P021 is a promising compound for this purpose.
Collapse
Affiliation(s)
- Silvia Bolognin
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Mario Buffelli
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Jukka Puoliväli
- Department of Behavioral Studies, Charles River Finland, Kuopio, Finland
| | - Khalid Iqbal
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA.
| |
Collapse
|
21
|
Iqbal K, Liu F, Gong CX. Alzheimer disease therapeutics: focus on the disease and not just plaques and tangles. Biochem Pharmacol 2014; 88:631-9. [PMID: 24418409 DOI: 10.1016/j.bcp.2014.01.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 12/26/2013] [Accepted: 01/02/2014] [Indexed: 12/13/2022]
Abstract
The bulk of AD research during the last 25 years has been Aβ-centric based on a strong faith in the Amyloid Cascade Hypothesis which is not supported by the data on humans. To date, Aβ-based therapeutic clinical trials on sporadic cases of AD have been negative. Although most likely the major reason for the failure is that Aβ is not an effective therapeutic target for sporadic AD, initiation of the treatment at mild to moderate stages of the disease is blamed as too late to be effective. Clinical trials on presymptomatic familial AD cases have been initiated with the logic that Aβ is a trigger of the disease and hence initiation of the Aβ immunotherapies several years before any clinical symptoms would be effective. There is an urgent need to explore targets other than Aβ. There is now increasing interest in inhibiting tau pathology, which does have a far more compelling rationale than Aβ. AD is multifactorial and over 99% of the cases are the sporadic form of the disease. Understanding of the various etiopathogenic mechanisms of sporadic AD and generation of the disease-relevant animal models are required to develop rational therapeutic targets and therapies. Treatment of AD will require both inhibition of neurodegeneration and regeneration of the brain.
Collapse
Affiliation(s)
- Khalid Iqbal
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA.
| | - Fei Liu
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA
| | - Cheng-Xin Gong
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA
| |
Collapse
|
22
|
Abstract
Down syndrome (DS), which results from an extra copy of chromosome 21 (trisomy 21), is the most common genetically defined cause of intellectual disability. Although no pharmacotherapy aimed at counteracting the cognitive and adaptive deficits associated with this genetic disorder has been approved at present, there have been several new promising studies on pharmacological agents capable of rescuing learning/memory deficits seen in mouse models of DS. Here, we will review the available mouse models for DS and provide a comprehensive, albeit not exhaustive review of the following preclinical research strategies: (1) SOD1 and antioxidant agents; (2) APP and γ-secretase inhibitors; (3) DYRK1A and the polyphenol epigallocatechin gallate (EGCG); (4) GIRK2 and fluoxetine; (5) adrenergic receptor agonists; (6) modulation of GABAA and GABAB receptors; (7) agonism of the hedgehog signaling pathway; (8) nerve growth factor (NGF) and other neurotrophic factors; (9) anticholinesterase (AChE) agents; and (10) antagonism of NMDA receptors. Finally, we will review briefly five different strategies in DS that have led to clinical studies that either have been concluded or are currently underway: (1) antioxidant therapy; (2) AChE therapy; (3) green tea extract therapy; (4) RG1662 therapy; and (5) memantine therapy. These are exciting times in DS research. Within a decade or so, it is well into the realm of possibility that new forms of pharmacotherapies might become valuable tools in the armamentarium of developmental clinicians, as adjutants to more traditional and proven forms of habilitative interventions aimed at improving the quality of life of individuals with DS.
Collapse
|
23
|
Kida E, Rabe A, Walus M, Albertini G, Golabek AA. Long-term running alleviates some behavioral and molecular abnormalities in Down syndrome mouse model Ts65Dn. Exp Neurol 2013. [DOI: 10.1016/j.expneurol.2012.11.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
24
|
Cardenas-Aguayo MDC, Kazim SF, Grundke-Iqbal I, Iqbal K. Neurogenic and neurotrophic effects of BDNF peptides in mouse hippocampal primary neuronal cell cultures. PLoS One 2013; 8:e53596. [PMID: 23320097 PMCID: PMC3539976 DOI: 10.1371/journal.pone.0053596] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 11/30/2012] [Indexed: 12/11/2022] Open
Abstract
The level of brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, is down regulated in Alzheimer’s disease (AD), Parkinson’s disease (PD), depression, stress, and anxiety; conversely the level of this neurotrophin is increased in autism spectrum disorders. Thus, modulating the level of BDNF can be a potential therapeutic approach for nervous system pathologies. In the present study, we designed five different tetra peptides (peptides B-1 to B-5) corresponding to different active regions of BDNF. These tetra peptides were found to be non-toxic, and they induced the expression of neuronal markers in mouse embryonic day 18 (E18) primary hippocampal neuronal cultures. Additionally, peptide B-5 induced the expression of BDNF and its receptor, TrkB, suggesting a positive feedback mechanism. The BDNF peptides induced only a moderate activation (phosphorylation at Tyr 706) of the TrkB receptor, which could be blocked by the Trk’s inhibitor, K252a. Peptide B-3, when combined with BDNF, potentiated the survival effect of this neurotrophin on H2O2-treated E18 hippocampal cells. Peptides B-3 and B-5 were found to work as partial agonists and as partial antagonists competing with BDNF to activate the TrkB receptor in a dose-dependent manner. Taken together, these results suggest that the described BDNF tetra peptides are neurotrophic, can modulate BDNF signaling in a partial agonist/antagonist way, and offer a novel therapeutic approach to neural pathologies where BDNF levels are dysregulated.
Collapse
Affiliation(s)
- Maria del Carmen Cardenas-Aguayo
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
| | - Syed Faraz Kazim
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
- Neural and Behavioral Science Graduate Program, State University of New York Downstate Medical Center, Brooklyn, New York, United States of America
| | - Inge Grundke-Iqbal
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
| | - Khalid Iqbal
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
- * E-mail:
| |
Collapse
|
25
|
From abnormal hippocampal synaptic plasticity in down syndrome mouse models to cognitive disability in down syndrome. Neural Plast 2012; 2012:101542. [PMID: 22848844 PMCID: PMC3403629 DOI: 10.1155/2012/101542] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 05/02/2012] [Accepted: 05/07/2012] [Indexed: 12/17/2022] Open
Abstract
Down syndrome (DS) is caused by the overexpression of genes on triplicated regions of human chromosome 21 (Hsa21). While the resulting physiological and behavioral phenotypes vary in their penetrance and severity, all individuals with DS have variable but significant levels of cognitive disability. At the core of cognitive processes is the phenomenon of synaptic plasticity, a functional change in the strength at points of communication between neurons. A wide variety of evidence from studies on DS individuals and mouse models of DS indicates that synaptic plasticity is adversely affected in human trisomy 21 and mouse segmental trisomy 16, respectively, an outcome that almost certainly extensively contributes to the cognitive impairments associated with DS. In this review, we will highlight some of the neurophysiological changes that we believe reduce the ability of trisomic neurons to undergo neuroplasticity-related adaptations. We will focus primarily on hippocampal networks which appear to be particularly impacted in DS and where consequently the majority of cellular and neuronal network research has been performed using DS animal models, in particular the Ts65Dn mouse. Finally, we will postulate on how altered plasticity may contribute to the DS cognitive disability.
Collapse
|
26
|
Mouse models of Down syndrome as a tool to unravel the causes of mental disabilities. Neural Plast 2012; 2012:584071. [PMID: 22685678 PMCID: PMC3364589 DOI: 10.1155/2012/584071] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 03/23/2012] [Accepted: 03/24/2012] [Indexed: 12/16/2022] Open
Abstract
Down syndrome (DS) is the most common genetic cause of mental disability. Based on the homology of Hsa21 and the murine chromosomes Mmu16, Mmu17 and Mmu10, several mouse models of DS have been developed. The most commonly used model, the Ts65Dn mouse, has been widely used to investigate the neural mechanisms underlying the mental disabilities seen in DS individuals. A wide array of neuromorphological alterations appears to compromise cognitive performance in trisomic mice. Enhanced inhibition due to alterations in GABA(A)-mediated transmission and disturbances in the glutamatergic, noradrenergic and cholinergic systems, among others, has also been demonstrated. DS cognitive dysfunction caused by neurodevelopmental alterations is worsened in later life stages by neurodegenerative processes. A number of pharmacological therapies have been shown to partially restore morphological anomalies concomitantly with cognition in these mice. In conclusion, the use of mouse models is enormously effective in the study of the neurobiological substrates of mental disabilities in DS and in the testing of therapies that rescue these alterations. These studies provide the basis for developing clinical trials in DS individuals and sustain the hope that some of these drugs will be useful in rescuing mental disabilities in DS individuals.
Collapse
|