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Zota I, Chanoumidou K, Gravanis A, Charalampopoulos I. Stimulating myelin restoration with BDNF: a promising therapeutic approach for Alzheimer's disease. Front Cell Neurosci 2024; 18:1422130. [PMID: 39285941 PMCID: PMC11402763 DOI: 10.3389/fncel.2024.1422130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Accepted: 08/12/2024] [Indexed: 09/19/2024] Open
Abstract
Alzheimer's Disease (AD) is a chronic neurodegenerative disorder constituting the most common form of dementia (60%-70% of cases). Although AD presents majorly a neurodegenerative pathology, recent clinical evidence highlights myelin impairment as a key factor in disease pathogenesis. The lack of preventive or restorative treatment is emphasizing the need to develop novel therapeutic approaches targeting to the causes of the disease. Recent studies in animals and patients have highlighted the loss of myelination of the neuronal axons as an extremely aggravating factor in AD, in addition to the formation of amyloid plaques and neurofibrillary tangles that are to date the main pathological hallmarks of the disease. Myelin breakdown represents an early stage event in AD. However, it is still unclear whether myelin loss is attributed only to exogenous factors like inflammatory processes of the tissue or to impaired oligodendrogenesis as well. Neurotrophic factors are well established protective molecules under many pathological conditions of the neural tissue, contributing also to proper myelination. Due to their inability to be used as drugs, many research efforts are focused on substituting neurotrophic activity with small molecules. Our research team has recently developed novel micromolecular synthetic neurotrophin mimetics (MNTs), selectively acting on neurotrophin receptors, and thus offering a unique opportunity for innovative therapies against neurodegenerative diseases. These small sized, lipophilic molecules address the underlying biological effect of these diseases (neuroprotective action), but also they exert significant neurogenic actions inducing neuronal replacement of the disease areas. One of the significant neurotrophin molecules in the Central Nervous System is Brain-Derived-Neurotrophin-Factor (BDNF). BDNF is a neurotrophin that not only supports neuroprotection and adult neurogenesis, but also mediates pro-myelinating effects in the CNS. BDNF binds with high-affinity on the TrkB neurotrophin receptor and enhances myelination by increasing the density of oligodendrocyte progenitor cells (OPCs) and playing an important role in CNS myelination. Conclusively, in the present review, we discuss the myelin pathophysiology in Alzheimer's Diseases, as well as the role of neurotrophins, and specifically BDNF, in myelin maintenance and restoration, revealing its valuable therapeutic potential against AD.
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Affiliation(s)
- Ioanna Zota
- Department of Pharmacology, Medical School, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology-Hellas (IMBB-FORTH), Heraklion, Greece
| | - Konstantina Chanoumidou
- Department of Pharmacology, Medical School, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology-Hellas (IMBB-FORTH), Heraklion, Greece
| | - Achille Gravanis
- Department of Pharmacology, Medical School, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology-Hellas (IMBB-FORTH), Heraklion, Greece
| | - Ioannis Charalampopoulos
- Department of Pharmacology, Medical School, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology-Hellas (IMBB-FORTH), Heraklion, Greece
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Gardner RS, Ambalavanar MT, Gold PE, Korol DL. Enhancement of response learning in male rats with intrastriatal infusions of a BDNF - TrkB agonist, 7,8-dihydroxyflavone. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.08.606692. [PMID: 39211174 PMCID: PMC11360987 DOI: 10.1101/2024.08.08.606692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Enhancement of learning and memory by cognitive and physical exercise may be mediated by brain-derived neurotrophic factor (BDNF) acting at tropomyosin receptor kinase B (TrkB). Upregulation of BDNF and systemic administration of a TrkB agonist, 7,8-dihydroxyflavone (7,8-DHF), enhance learning of several hippocampus-sensitive tasks in rodents. Although BDNF and 7,8-DHF enhance functions of other brain areas too, these effects have mainly targeted non-cognitive functions. One goal of the present study was to determine whether 7,8-DHF would act beyond the hippocampus to enhance cognitive functions sensitive to manipulations of the striatum. Here, we examined the effects of intrastriatal infusions of 7,8-DHF on learning a striatum-sensitive response maze and on phosphorylation of TrkB receptors in 3-month-old male Sprague Dawley rats. Most prior studies of BDNF and 7,8-DHF effects on learning and memory have administered the drugs for days to months before assessing effects on cognition. A second goal of the present study was to determine whether a single drug treatment near the time of training would effectively enhance learning. Moreover, 7,8-DHF is often tested for its ability to reverse impairments in learning and memory rather than to enhance these functions in the absence of impairments. Thus, a third goal of this experiment was to evaluate the efficacy of 7,8-DHF in enhancing learning in unimpaired rats. In untrained rats, intrastriatal infusions of 7,8-DHF resulted in phosphorylation of TrkB receptors, suggesting that 7,8-DHF acted as a TrkB agonist and BDNF mimic. The findings that a single, intra-striatal infusion of 7,8-DHF 20 min before training enhanced response learning in rats suggest that, in addition to its trophic effects, BDNF modulates learning and memory through receptor mediated cell signaling events.
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Charou D, Rogdakis T, Latorrata A, Valcarcel M, Papadogiannis V, Athanasiou C, Tsengenes A, Papadopoulou MA, Lypitkas D, Lavigne MD, Katsila T, Wade RC, Cader MZ, Calogeropoulou T, Gravanis A, Charalampopoulos I. Comprehensive characterization of the neurogenic and neuroprotective action of a novel TrkB agonist using mouse and human stem cell models of Alzheimer's disease. Stem Cell Res Ther 2024; 15:200. [PMID: 38971770 PMCID: PMC11227723 DOI: 10.1186/s13287-024-03818-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 06/26/2024] [Indexed: 07/08/2024] Open
Abstract
BACKGROUND Neural stem cell (NSC) proliferation and differentiation in the mammalian brain decreases to minimal levels postnatally. Nevertheless, neurogenic niches persist in the adult cortex and hippocampus in rodents, primates and humans, with adult NSC differentiation sharing key regulatory mechanisms with development. Adult neurogenesis impairments have been linked to Alzheimer's disease (AD) pathology. Addressing these impairments by using neurotrophic factors is a promising new avenue for therapeutic intervention based on neurogenesis. However, this possibility has been hindered by technical difficulties of using in-vivo models to conduct screens, including working with scarce NSCs in the adult brain and differences between human and mouse models or ethical limitations. METHODS Here, we use a combination of mouse and human stem cell models for comprehensive in-vitro characterization of a novel neurogenic compound, focusing on the brain-derived neurotrophic factor (BDNF) pathway. The ability of ENT-A011, a steroidal dehydroepiandrosterone derivative, to activate the tyrosine receptor kinase B (TrkB) receptor was tested through western blotting in NIH-3T3 cells and its neurogenic and neuroprotective action were assessed through proliferation, cell death and Amyloid-β (Aβ) toxicity assays in mouse primary adult hippocampal NSCs, mouse embryonic cortical NSCs and neural progenitor cells (NPCs) differentiated from three human induced pluripotent stem cell lines from healthy and AD donors. RNA-seq profiling was used to assess if the compound acts through the same gene network as BDNF in human NPCs. RESULTS ENT-A011 was able to increase proliferation of mouse primary adult hippocampal NSCs and embryonic cortical NSCs, in the absence of EGF/FGF, while reducing Aβ-induced cell death, acting selectively through TrkB activation. The compound was able to increase astrocytic gene markers involved in NSC maintenance, protect hippocampal neurons from Αβ toxicity and prevent synapse loss after Aβ treatment. ENT-A011 successfully induces proliferation and prevents cell death after Aβ toxicity in human NPCs, acting through a core gene network shared with BDNF as shown through RNA-seq. CONCLUSIONS Our work characterizes a novel BDNF mimetic with preferable pharmacological properties and neurogenic and neuroprotective actions in Alzheimer's disease via stem cell-based screening, demonstrating the promise of stem cell systems for short-listing competitive candidates for further testing.
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Affiliation(s)
- Despoina Charou
- Department of Pharmacology, Medical School, University of Crete, 71003, Heraklion, Greece
- Foundation for Research and Technology-Hellas (IMBB-FORTH), Institute of Molecular Biology and Biotechnology, 70013, Heraklion, Greece
| | - Thanasis Rogdakis
- Department of Pharmacology, Medical School, University of Crete, 71003, Heraklion, Greece
- Foundation for Research and Technology-Hellas (IMBB-FORTH), Institute of Molecular Biology and Biotechnology, 70013, Heraklion, Greece
| | - Alessia Latorrata
- Institute of Chemical Biology, National Hellenic Research Foundation, 11635, Athens, Greece
| | - Maria Valcarcel
- Innovative Technologies in Biological Systems SL (INNOPROT), 48160, Derio, Bizkaia, Spain
| | - Vasileios Papadogiannis
- Hellenic Centre for Marine Research (HCMR), Institute of Marine Biology Biotechnology and Aquaculture (IMBBC), Heraklion, Crete, Greece
| | - Christina Athanasiou
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), 69118, Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, 69120, Heidelberg, Germany
- Heidelberg Biosciences International Graduate School, Heidelberg University, 69120, Heidelberg, Germany
| | - Alexandros Tsengenes
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), 69118, Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, 69120, Heidelberg, Germany
- Heidelberg Biosciences International Graduate School, Heidelberg University, 69120, Heidelberg, Germany
| | - Maria Anna Papadopoulou
- Department of Pharmacology, Medical School, University of Crete, 71003, Heraklion, Greece
- Foundation for Research and Technology-Hellas (IMBB-FORTH), Institute of Molecular Biology and Biotechnology, 70013, Heraklion, Greece
| | - Dimitrios Lypitkas
- Department of Pharmacology, Medical School, University of Crete, 71003, Heraklion, Greece
- Foundation for Research and Technology-Hellas (IMBB-FORTH), Institute of Molecular Biology and Biotechnology, 70013, Heraklion, Greece
| | - Matthieu D Lavigne
- Foundation for Research and Technology-Hellas (IMBB-FORTH), Institute of Molecular Biology and Biotechnology, 70013, Heraklion, Greece
| | - Theodora Katsila
- Institute of Chemical Biology, National Hellenic Research Foundation, 11635, Athens, Greece
| | - Rebecca C Wade
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), 69118, Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, 69120, Heidelberg, Germany
- Center for Molecular Biology (ZMBH), DKFZ-ZMBH Alliance, Heidelberg University, 69120, Heidelberg, Germany
- Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, 69120, Heidelberg, Germany
| | - M Zameel Cader
- Translational Molecular Neuroscience Group, Dorothy Crowfoot Hodgkin Building, Kavli Institute for Nanoscience, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | | | - Achille Gravanis
- Department of Pharmacology, Medical School, University of Crete, 71003, Heraklion, Greece
- Foundation for Research and Technology-Hellas (IMBB-FORTH), Institute of Molecular Biology and Biotechnology, 70013, Heraklion, Greece
| | - Ioannis Charalampopoulos
- Department of Pharmacology, Medical School, University of Crete, 71003, Heraklion, Greece.
- Foundation for Research and Technology-Hellas (IMBB-FORTH), Institute of Molecular Biology and Biotechnology, 70013, Heraklion, Greece.
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Dhaliwal N, Dhaliwal J, Chopra K. 7, 8-dihydroxyflavone Ameliorates Cholinergic Dysfunction, Inflammation, Oxidative Stress, and Apoptosis in a Rat Model of Vascular Dementia. Neurochem Res 2024; 49:1137-1149. [PMID: 38300457 DOI: 10.1007/s11064-023-04090-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 12/16/2023] [Accepted: 12/19/2023] [Indexed: 02/02/2024]
Abstract
Vascular dementia (VD) is a degenerative cerebrovascular disorder associated with progressive cognitive decline. Previous reports have shown that 7,8-dihydroxyflavone (7,8-DHF), a well-known TrkB agonist, effectively ameliorates cognitive deficits in several disease models. Therefore, this study investigated the protective effects of 7,8-DHF against 2-VO-induced VD. VD was established in rats using the permanent bilateral carotid arteries occlusion (two-vessel occlusion, 2-VO) model. 7,8-DHF (5, 10, and 20 mg/kg) and Donepezil (10 mg/kg) were administered for 4 weeks. Memory function was assessed by the novel objective recognition task (NOR) and Morris water maze (MWM) tests. Inflammatory (TNF-α, IL-1β, and NF-kβ), oxidative stress, and apoptotic (BAX, BCL-2, caspase-3) markers, along with the activity of choline acetylcholinesterase (AChE) was assessed. p-AKT, p-CREB, BDNF, and neurotransmitter (NT) (GLU, GABA, and ACh) levels were also analyzed in the hippocampus of 2-VO rats. Our results show that 7,8-DHF effectively improved memory performance and cholinergic dysfunction in 2-VO model rats. Furthermore, 7,8-DHF treatment also increased p-AKT, p-CREB, and BDNF levels, suppressed oxidative, inflammatory, and apoptotic markers, and restored altered NT levels in the hippocampus. These findings imply that 7, 8-DHF may act via multiple mechanisms and as such serve as a promising neuroprotective agent in the context of VD.
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Affiliation(s)
- Navneet Dhaliwal
- Pharmacology Division, University Institute of Pharmaceutical Sciences (UIPS), Panjab University, Chandigarh, 160014, India
| | - Jatinder Dhaliwal
- Pharmacology Division, University Institute of Pharmaceutical Sciences (UIPS), Panjab University, Chandigarh, 160014, India
| | - Kanwaljit Chopra
- Pharmacology Division, University Institute of Pharmaceutical Sciences (UIPS), Panjab University, Chandigarh, 160014, India.
- Pharmacology Research Laboratory, UGC Centre of Advanced Studies, University Institute of Pharmaceutical Sciences (UIPS), Panjab University, Chandigarh, 160 014, India.
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Zagrebelsky M, Korte M. Are TrkB receptor agonists the right tool to fulfill the promises for a therapeutic value of the brain-derived neurotrophic factor? Neural Regen Res 2024; 19:29-34. [PMID: 37488840 PMCID: PMC10479861 DOI: 10.4103/1673-5374.374138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/20/2023] [Accepted: 03/27/2023] [Indexed: 07/26/2023] Open
Abstract
Brain-derived neurotrophic factor signaling via its receptor tropomyosin receptor kinase B regulates several crucial physiological processes. It has been shown to act in the brain, promoting neuronal survival, growth, and plasticity as well as in the rest of the body where it is involved in regulating for instance aspects of the metabolism. Due to its crucial and very pleiotropic activity, reduction of brain-derived neurotrophic factor levels and alterations in the brain-derived neurotrophic factor/tropomyosin receptor kinase B signaling have been found to be associated with a wide spectrum of neurological diseases. However, because of its poor bioavailability and pharmacological properties, brain-derived neurotrophic factor itself has a very low therapeutic value. Moreover, the concomitant binding of exogenous brain-derived neurotrophic factor to the p75 neurotrophin receptor has the potential to elicit several unwanted and deleterious side effects. Therefore, developing tools and approaches to specifically promote tropomyosin receptor kinase B signaling has become an important goal of translational research. Among the newly developed tools are different categories of tropomyosin receptor kinase B receptor agonist molecules. In this review, we give a comprehensive description of the different tropomyosin receptor kinase B receptor agonist drugs developed so far and of the results of their application in animal models of several neurological diseases. Moreover, we discuss the main benefits of tropomyosin receptor kinase B receptor agonists, concentrating especially on the new tropomyosin receptor kinase B agonist antibodies. The benefits observed both in vitro and in vivo upon application of tropomyosin receptor kinase B receptor agonist drugs seem to predominantly depend on their general neuroprotective activity and their ability to promote neuronal plasticity. Moreover, tropomyosin receptor kinase B agonist antibodies have been shown to specifically bind the tropomyosin receptor kinase B receptor and not p75 neurotrophin receptor. Therefore, while, based on the current knowledge, the tropomyosin receptor kinase B receptor agonists do not seem to have the potential to reverse the disease pathology per se, promoting brain-derived neurotrophic factor/tropomyosin receptor kinase B signaling still has a very high therapeutic relevance.
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Affiliation(s)
- Marta Zagrebelsky
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig, Braunschweig, Germany
| | - Martin Korte
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig, Braunschweig, Germany
- Helmholtz Centre for Infection Research, AG NIND, Braunschweig, Germany
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Rawlings-Mortimer F, Lazari A, Tisca C, Tachrount M, Martins-Bach AB, Miller KL, Lerch JP, Johansen-Berg H. 7,8-dihydroxyflavone enhances long-term spatial memory and alters brain volume in wildtype mice. Front Syst Neurosci 2023; 17:1134594. [PMID: 37008453 PMCID: PMC10057119 DOI: 10.3389/fnsys.2023.1134594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 02/21/2023] [Indexed: 03/17/2023] Open
Abstract
Introduction: 7,8-dihydroxyflavone (7,8-DHF) is a low molecular weight compound that can cross the blood brain barrier and has been implicated in numerous functions and behaviours. It is thought to have neuroprotective capability and has been shown to alleviate symptoms in a wide range of diseases.Methods: 7,8-DHF was administered systemically to wildtype mice during Morris water maze training. Long-term spatial memory was assessed 28 days later. Ex-vivo T2-weighted (T2w) imaging was undertaken on a subset of these mice to assess brain-wide changes in volume.Results: We found that systemic 7,8-DHF administration during the training period enhanced spatial memory 28 days later. Volumetric changes were observed in numerous brain regions associated with a broad range of functions including cognition, sensory, and motor processing.Discussion: Our findings give the first whole brain overview of long-term anatomical changes following 7,8-DHF administration providing valuable information for assessing and understanding the widespread effects this drug has been shown to have in behaviour and disease.
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Timalsina B, Haque MN, Choi HJ, Dash R, Moon IS. Thymol in Trachyspermum ammi seed extract exhibits neuroprotection, learning, and memory enhancement in scopolamine-induced Alzheimer's disease mouse model. Phytother Res 2023. [PMID: 36808768 DOI: 10.1002/ptr.7777] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 09/18/2022] [Accepted: 01/29/2023] [Indexed: 02/22/2023]
Abstract
Several reports have stated the neuroprotective and learning/memory effects of Tachyspermum ammi seed extract (TASE) and its principal component thymol; however, little is known about its underlying molecular mechanisms and neurogenesis potential. This study aimed to provide insights into TASE and a thymol-mediated multifactorial therapeutic approach in a scopolamine-induced Alzheimer's disease (AD) mouse model. TASE and thymol supplementation significantly reduced oxidative stress markers such as brain glutathione, hydrogen peroxide, and malondialdehyde in mouse whole brain homogenates. Tumor necrosis factor-alpha was significantly downregulated, whereas the elevation of brain-derived neurotrophic factor and phospho-glycogen synthase kinase-3 beta (serine 9) enhanced learning and memory in the TASE- and thymol-treated groups. A significant reduction in the accumulation of Aβ 1-42 peptides was observed in the brains of TASE- and thymol-treated mice. Furthermore, TASE and thymol significantly promoted adult neurogenesis, with increased doublecortin positive neurons in the subgranular and polymorphic zones of the dentate gyrus in treated-mice. Collectively, TASE and thymol could potentially act as natural therapeutic agents for the treatment of neurodegenerative disorders, such as AD.
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Affiliation(s)
- Binod Timalsina
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, Korea
| | - Md Nazmul Haque
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, Korea.,Department of Fisheries Biology and Genetics, Patuakhali Science and Technology University, Patuakhali, Bangladesh
| | - Ho Jin Choi
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, Korea
| | - Raju Dash
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, Korea
| | - Il Soo Moon
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, Korea
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Oral Administration of TrkB Agonist, 7, 8-Dihydroxyflavone Regenerates Hair Cells and Restores Function after Gentamicin-Induced Vestibular Injury in Guinea Pig. Pharmaceutics 2023; 15:pharmaceutics15020493. [PMID: 36839815 PMCID: PMC9966733 DOI: 10.3390/pharmaceutics15020493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/24/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
The causes of vestibular dysfunction include the loss of hair cells (HCs), synapses beneath the HCs, and nerve fibers. 7, 8-dihydroxyflavone (DHF) mimics the physiological functions of brain-derived neurotrophic factor. We investigated the effects of the orally-administered DHF in the guinea pig crista ampullaris after gentamicin (GM)-induced injury. Twenty animals treated with GM received daily administration of DHF or saline for 14 or 28 days (DHF (+) or DHF (-) group; N = 5, each). At 14 days after GM treatment, almost all of the HCs had disappeared in both groups. At 28 days, the HCs number in DHF (+) and DHF (-) groups was 74% and 49%, respectively, compared to GM-untreated control. In the ampullary nerves, neurofilament 200 positive rate in the DHF (+) group was 91% at 28 days, which was significantly higher than 42% in DHF (-). On day 28, the synaptic connections observed between C-terminal-binding protein 2-positive and postsynaptic density protein-95-positive puncta were restored, and caloric response was significantly improved in DHF (+) group (canal paresis: 57.4% in DHF (+) and 100% in DHF (-)). Taken together, the oral administration of DHF may be a novel therapeutic approach for treating vestibular dysfunction in humans.
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Díaz A, Flores I, Treviño S. Neurotrophic fragments as therapeutic alternatives to ameliorate brain aging. Neural Regen Res 2023; 18:51-56. [PMID: 35799508 PMCID: PMC9241392 DOI: 10.4103/1673-5374.331867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Aging is a global phenomenon and a complex biological process of all living beings that introduces various changes. During this physiological process, the brain is the most affected organ due to changes in its structural and chemical functions, such as changes in plasticity and decrease in the number, diameter, length, and branching of dendrites and dendritic spines. Likewise, it presents a great reduction in volume resulting from the contraction of the gray matter. Consequently, aging can affect not only cognitive functions, including learning and memory, but also the quality of life of older people. As a result of the phenomena, various molecules with notable neuroprotective capacity have been proposed, which provide a therapeutic alternative for people under conditions of aging or some neurodegenerative diseases. It is important to indicate that in recent years the use of molecules with neurotrophic activity has shown interesting results when evaluated in in vivo models. This review aims to describe the neurotrophic potential of molecules such as resveratrol (3,5,4′-trihydroxystilbene), neurotrophins (brain-derived neurotrophic factor), and neurotrophic-type compounds such as the terminal carboxyl domain of the heavy chain of tetanus toxin, cerebrolysin, neuropeptide-12, and rapamycin. Most of these molecules have been evaluated by our research group. Studies suggest that these molecules exert an important therapeutic potential, restoring brain function in aging conditions or models of neurodegenerative diseases. Hence, our interest is in describing the current scientific evidence that supports the therapeutic potential of these molecules with active neurotrophic.
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Nordvall G, Forsell P, Sandin J. Neurotrophin-targeted therapeutics: A gateway to cognition and more? Drug Discov Today 2022; 27:103318. [PMID: 35850433 DOI: 10.1016/j.drudis.2022.07.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/05/2022] [Accepted: 07/12/2022] [Indexed: 02/09/2023]
Abstract
Neurotrophins, such as brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), are small proteins expressed in the brain and peripheral tissues, which regulate several key aspects of neuronal function, including neurogenesis, synaptic plasticity and neuroprotection, but also programmed cell death. This broad range of effects is a result of a complex downstream signaling pathway, with differential spatial and temporal activation patterns further diversifying their physiological effects. Alterations in neurotrophin levels, or known polymorphisms in neurotrophin genes, have been linked to a variety of disorders, including depression and Alzheimer's disease (AD). Historically, their therapeutic potential in these disorders has been hampered by the lack of suitable tool molecules for clinical studies. However, recent advancements have led to the development of new therapeutic candidates, which are now in clinical testing.
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Sahin E, Saglam N, Erdem S, Alvuroglu E, Abidin I, Yulug E, Alver A. 7,8-Dihydroxyflavone alleviates Endoplasmic Reticulum Stress in cafeteria diet-induced metabolic syndrome. Life Sci 2022; 306:120781. [PMID: 35835252 DOI: 10.1016/j.lfs.2022.120781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 06/29/2022] [Accepted: 07/01/2022] [Indexed: 10/17/2022]
Abstract
AIMS Prolonged Endoplasmic Reticulum Stress (ERS) is involved in the pathogenesis of metabolic syndrome, including type-2 diabetes mellitus, cardiovascular diseases, atherosclerosis, obesity, and fatty liver disease. There have been significant efforts to discover molecules to treat ERS and/or to ameliorate associate symptoms. In this study, we investigated the effect of 7,8-Dihydroxyflavone (7,8-DHF) on ERS in liver and pancreas tissues in a cafeteria (CAF) diet induced metabolic syndrome model. MAIN METHODS Male C57BL/6 mice were fed CAF diet for 16 weeks and 7,8-DHF was administered intraperitoneally (5 mg/kg/day) for last four weeks. 78-kDa glucose-regulated protein (GRP78) and C/EBP homologous protein (CHOP) in liver and pancreas tissues, insulin and interleukin-1β (IL-1β) in serum were analyzed by ELISA method and serum biochemistry parameters were analyzed with autoanalyzer. GRP78 and CHOP gene expression levels were determined by qRT-PCR. In addition, histopathological analyzes were performed on liver and pancreas tissues. KEY FINDINGS Findings revealed that CAF diet caused metabolic abnormalities, insulin resistance and inflammation in serum and triggered ERS in pancreas and liver tissues. 7,8-DHF treatment significantly reduced metabolic abnormalities by reducing serum biochemical parameters, HOMO-IR and IL-1β levels. qRT-PCR and ELISA results indicated that 7,8-DHF treatment down-regulated GRP78 and CHOP expression and protein levels in the liver and GRP78 expression in pancreas. Efficiency of 7,8-DHF in these tissues was also demonstrated by histopathological tests. SIGNIFICANCE In conclusion, CAF diet-induced metabolic syndrome model, 7,8-DHF suppressed ERS and ERS-induced metabolic disorders in both liver and pancreas. Therefore, 7,8-DHF may potentially be a novel therapeutic compound to ameliorate ERS and related metabolic symptoms.
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Affiliation(s)
- Elif Sahin
- Department of Medical Biochemistry, Graduate School of Medical Science, Karadeniz Technical University, Trabzon, Turkiye.
| | - Neslihan Saglam
- Department of Medical Biochemistry, Graduate School of Medical Science, Karadeniz Technical University, Trabzon, Turkiye
| | - Seniz Erdem
- Department of Medical Biochemistry, Graduate School of Medical Science, Karadeniz Technical University, Trabzon, Turkiye
| | - Elif Alvuroglu
- Department of Histology and Embryology, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkiye
| | - Ismail Abidin
- Department of Biophysics, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkiye
| | - Esin Yulug
- Department of Histology and Embryology, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkiye
| | - Ahmet Alver
- Department of Medical Biochemistry, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkiye
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Liraglutide, 7,8-DHF and their co-treatment prevents loss of vision and cognitive decline in a Wolfram syndrome rat model. Sci Rep 2021; 11:2275. [PMID: 33500541 PMCID: PMC7838169 DOI: 10.1038/s41598-021-81768-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/11/2021] [Indexed: 12/13/2022] Open
Abstract
Wolfram syndrome (WS) is a monogenic progressive neurodegenerative disease and is characterized by various neurological symptoms, such as optic nerve atrophy, loss of vision, cognitive decline, memory impairment, and learning difficulties. GLP1 receptor agonist liraglutide and BDNF mimetic 7,8-dihydroxyflavone (7,8-DHF) have had protective effect to visual pathway and to learning and memory in different rat models of neurodegenerative disorders. Although synergistic co-treatment effect has not been reported before and therefore the aim of the current study was to investigate liraglutide, 7,8-DHF and most importantly for the first time their co-treatment effect on degenerative processes in WS rat model. We took 9 months old WS rats and their wild-type (WT) control animals and treated them daily with liraglutide, 7,8-DHF or with the combination of liraglutide and 7,8-DHF up to the age of 12.5 months (n = 47, 5-8 per group). We found that liraglutide, 7,8-DHF and their co-treatment all prevented lateral ventricle enlargement, improved learning in Morris Water maze, reduced neuronal inflammation, delayed the progression of optic nerve atrophy, had remyelinating effect on optic nerve and thereby improved visual acuity in WS rats compared to WT controls. Thus, the use of the liraglutide, 7,8-DHF and their co-treatment could potentially be used as a therapeutic intervention to induce neuroprotection or even neuronal regeneration.
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13
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Ettcheto M, Busquets O, Cano A, Sánchez-Lopez E, Manzine PR, Espinosa-Jimenez T, Verdaguer E, Sureda FX, Olloquequi J, Castro-Torres RD, Auladell C, Folch J, Casadesús G, Camins A. Pharmacological Strategies to Improve Dendritic Spines in Alzheimer's Disease. J Alzheimers Dis 2021; 82:S91-S107. [PMID: 33325386 PMCID: PMC9853464 DOI: 10.3233/jad-201106] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
To deeply understand late onset Alzheimer's disease (LOAD), it may be necessary to change the concept that it is a disease exclusively driven by aging processes. The onset of LOAD could be associated with a previous peripheral stress at the level of the gut (changes in the gut microbiota), obesity (metabolic stress), and infections, among other systemic/environmental stressors. The onset of LOAD, then, may result from the generation of mild peripheral inflammatory processes involving cytokine production associated with peripheral stressors that in a second step enter the brain and spread out the process causing a neuroinflammatory brain disease. This hypothesis could explain the potential efficacy of Sodium Oligomannate (GV-971), a mixture of acidic linear oligosaccharides that have shown to remodel gut microbiota and slowdown LOAD. However, regardless of the origin of the disease, the end goal of LOAD-related preventative or disease modifying therapies is to preserve dendritic spines and synaptic plasticity that underlay and support healthy cognition. Here we discuss how systemic/environmental stressors impact pathways associated with the regulation of spine morphogenesis and synaptic maintenance, including insulin receptor and the brain derived neurotrophic factor signaling. Spine structure remodeling is a plausible mechanism to maintain synapses and provide cognitive resilience in LOAD patients. Importantly, we also propose a combination of drugs targeting such stressors that may be able to modify the course of LOAD by acting on preventing dendritic spines and synapsis loss.
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Affiliation(s)
- Miren Ettcheto
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Science, University of Barcelona, Barcelona, Spain
- Department of Biochemistry and Biotechnology, Faculty of Medicine and Life Science, University Rovira i Virgili, Reus, Spain
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Institute of Neuroscience, University of Barcelona, Barcelona, Spain
| | - Oriol Busquets
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Science, University of Barcelona, Barcelona, Spain
- Department of Biochemistry and Biotechnology, Faculty of Medicine and Life Science, University Rovira i Virgili, Reus, Spain
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Institute of Neuroscience, University of Barcelona, Barcelona, Spain
| | - Amanda Cano
- Institute of Neuroscience, University of Barcelona, Barcelona, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, Barcelona, Spain
- Department of Pharmacy, Pharmaceutical Technology and Physical Chemistry, Faculty of Pharmacy and Food Science, University of Barcelona, Barcelona, Spain
| | - Elena Sánchez-Lopez
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, Barcelona, Spain
- Department of Pharmacy, Pharmaceutical Technology and Physical Chemistry, Faculty of Pharmacy and Food Science, University of Barcelona, Barcelona, Spain
| | - Patricia R. Manzine
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Science, University of Barcelona, Barcelona, Spain
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Institute of Neuroscience, University of Barcelona, Barcelona, Spain
- Department of Gerontology, Federal University of São Carlos (UFSCar), São Carlos, Brazil
| | - Triana Espinosa-Jimenez
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Science, University of Barcelona, Barcelona, Spain
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Institute of Neuroscience, University of Barcelona, Barcelona, Spain
| | - Ester Verdaguer
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Institute of Neuroscience, University of Barcelona, Barcelona, Spain
- Departamento de Biología Celular y Molecular, Laboratorio de Neurobiología de laneurotransmisión, C.U.C.B.A, Universidad de Guadalajara, Jalisco, México
| | - Francesc X. Sureda
- Department of Biochemistry and Biotechnology, Faculty of Medicine and Life Science, University Rovira i Virgili, Reus, Spain
| | - Jordi Olloquequi
- Laboratory of Cellular and Molecular Pathology, Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Talca, Chile
| | - Ruben D. Castro-Torres
- Departamento de Biología Celular y Molecular, Laboratorio de Neurobiología de laneurotransmisión, C.U.C.B.A, Universidad de Guadalajara, Jalisco, México
| | - Carme Auladell
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Institute of Neuroscience, University of Barcelona, Barcelona, Spain
- Department of Cellular Biology, Physiology and Immunology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Jaume Folch
- Department of Biochemistry and Biotechnology, Faculty of Medicine and Life Science, University Rovira i Virgili, Reus, Spain
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Gemma Casadesús
- Department of Biological Sciences, Kent State University, Kent, OH, USA
| | - Antoni Camins
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Science, University of Barcelona, Barcelona, Spain
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
- Institute of Neuroscience, University of Barcelona, Barcelona, Spain
- Laboratory of Cellular and Molecular Pathology, Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Talca, Chile
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14
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Ötzkan S, Muller WE, Gibson Wood W, Eckert GP. Effects of 7,8-Dihydroxyflavone on Lipid Isoprenoid and Rho Protein Levels in Brains of Aged C57BL/6 Mice. Neuromolecular Med 2020; 23:130-139. [PMID: 33377988 PMCID: PMC7929957 DOI: 10.1007/s12017-020-08640-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/25/2020] [Indexed: 12/13/2022]
Abstract
Synaptic impairment may be the main cause of cognitive dysfunction in brain aging that is probably due to a reduction in synaptic contact between the axonal buttons and dendritic spines. Rho proteins including the small GTPase Rac1 have become key regulators of neuronal morphogenesis that supports synaptic plasticity. Small Rho- and Ras-GTPases are post-translationally modified by the isoprenoids geranylgeranyl pyrophosphate (GGPP) and farnesyl pyrophosphate (FPP), respectively. For all GTPases, anchoring in the plasma membrane is essential for their activation by guanine nucleotide exchange factors (GEFs). Rac1-specific GEFs include the protein T lymphoma invasion and metastasis 1 (Tiam1). Tiam1 interacts with the TrkB receptor to mediate the brain-derived neurotrophic factor (BDNF)-induced activation of Rac1, resulting in cytoskeletal rearrangement and changes in cellular morphology. The flavonoid 7,8-dihydroxyflavone (7,8-DHF) acts as a highly affine-selective TrkB receptor agonist and causes the dimerization and autophosphorylation of the TrkB receptor and thus the activation of downstream signaling pathways. In the current study, we investigated the effects of 7,8-DHF on cerebral lipid isoprenoid and Rho protein levels in male C57BL/6 mice aged 3 and 23 months. Aged mice were daily treated with 100 mg/kg b.w. 7,8-DHF by oral gavage for 21 days. FPP, GGPP, and cholesterol levels were determined in brain tissue. In the same tissue, the protein content of Tiam1 and TrkB in was measured. The cellular localization of the small Rho-GTPase Rac1 and small Rab-GTPase Rab3A was studied in total brain homogenates and membrane preparations. We report the novel finding that 7,8-DHF restored levels of the Rho proteins Rac1 and Rab3A in membrane preparations isolated from brains of treated aged mice. The selective TrkB agonist 7,8-DHF did not affect BDNF and TrkB levels, but restored Tiam1 levels that were found to be reduced in brains of aged mice. FPP, GGPP, and cholesterol levels were significantly elevated in brains of aged mice but not changed by 7,8-DHF treatment. Hence, 7,8-DHF may be useful as pharmacological tool to treat age-related cognitive dysfunction although the underlying mechanisms need to be elucidated in detail.
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Affiliation(s)
- Sarah Ötzkan
- Department of Pharmacology, Biocenter Niederursel, University of Frankfurt, Goethe-University, Max-von-Laue-St. 9, 60438, Frankfurt, Germany
| | - Walter E Muller
- Department of Pharmacology, Biocenter Niederursel, University of Frankfurt, Goethe-University, Max-von-Laue-St. 9, 60438, Frankfurt, Germany
| | - W Gibson Wood
- Department of Pharmacology, Geriatric Research, Education and Clinical Center, University of Minnesota School of Medicine, VAMC, Minneapolis, MN, 55417, USA
| | - Gunter P Eckert
- Department of Pharmacology, Biocenter Niederursel, University of Frankfurt, Goethe-University, Max-von-Laue-St. 9, 60438, Frankfurt, Germany.
- Institute of Nutritional Sciences, Laboratory for Nutrition in Prevention and Therapy, Justus-Liebig-University of Giessen, Biomedical Research Center Seltersberg (BFS), Schubertstr. 81, 35392, Giessen, Germany.
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Zagrebelsky M, Tacke C, Korte M. BDNF signaling during the lifetime of dendritic spines. Cell Tissue Res 2020; 382:185-199. [PMID: 32537724 PMCID: PMC7529616 DOI: 10.1007/s00441-020-03226-5] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/27/2020] [Indexed: 12/13/2022]
Abstract
Dendritic spines are tiny membrane specialization forming the postsynaptic part of most excitatory synapses. They have been suggested to play a crucial role in regulating synaptic transmission during development and in adult learning processes. Changes in their number, size, and shape are correlated with processes of structural synaptic plasticity and learning and memory and also with neurodegenerative diseases, when spines are lost. Thus, their alterations can correlate with neuronal homeostasis, but also with dysfunction in several neurological disorders characterized by cognitive impairment. Therefore, it is important to understand how different stages in the life of a dendritic spine, including formation, maturation, and plasticity, are strictly regulated. In this context, brain-derived neurotrophic factor (BDNF), belonging to the NGF-neurotrophin family, is among the most intensively investigated molecule. This review would like to report the current knowledge regarding the role of BDNF in regulating dendritic spine number, structure, and plasticity concentrating especially on its signaling via its two often functionally antagonistic receptors, TrkB and p75NTR. In addition, we point out a series of open points in which, while the role of BDNF signaling is extremely likely conclusive, evidence is still missing.
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Affiliation(s)
- Marta Zagrebelsky
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig, Spielmannstr 7, 38106, Braunschweig, Germany.
- Helmholtz Centre for Infection Research, AG NIND, Inhoffenstr. 7, D-38124, Braunschweig, Germany.
| | - Charlotte Tacke
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig, Spielmannstr 7, 38106, Braunschweig, Germany
| | - Martin Korte
- Division of Cellular Neurobiology, Zoological Institute, TU Braunschweig, Spielmannstr 7, 38106, Braunschweig, Germany.
- Helmholtz Centre for Infection Research, AG NIND, Inhoffenstr. 7, D-38124, Braunschweig, Germany.
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16
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Emili M, Guidi S, Uguagliati B, Giacomini A, Bartesaghi R, Stagni F. Treatment with the flavonoid 7,8-Dihydroxyflavone: a promising strategy for a constellation of body and brain disorders. Crit Rev Food Sci Nutr 2020; 62:13-50. [DOI: 10.1080/10408398.2020.1810625] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Marco Emili
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Sandra Guidi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Beatrice Uguagliati
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Andrea Giacomini
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Renata Bartesaghi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Fiorenza Stagni
- Department for Life Quality Studies, University of Bologna, Rimini, Italy
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17
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Di Palma M, Sartini S, Lattanzi D, Cuppini R, Pita-Rodriguez M, Diaz-Carmenate Y, Narvaez M, Fuxe K, Borroto-Escuela DO, Ambrogini P. Evidence for the existence of A2AR-TrkB heteroreceptor complexes in the dorsal hippocampus of the rat brain: Potential implications of A2AR and TrkB interplay upon ageing. Mech Ageing Dev 2020; 190:111289. [PMID: 32565059 DOI: 10.1016/j.mad.2020.111289] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 06/14/2020] [Accepted: 06/16/2020] [Indexed: 10/24/2022]
Abstract
Adenosine A2A receptors (A2AR) are crucial in facilitating the BDNF action on synaptic transmission in the rat hippocampus primarily upon ageing. Furthermore, it has been suggested that A2AR-Tropomyosin related kinase B receptor (TrkB) crosstalk has a pivotal role in adenosine A2AR-mediated modulation of the BDNF action on hippocampal plasticity. Considering the impact of the above receptors interplay on what concerns BDNF-induced enhancement of synaptic transmission, gaining a better insight into the mechanisms behind this powerful crosstalk becomes of primary interest. Using in situ proximity ligation assay (PLA), the existence of a direct physical interaction between adenosine A2AR and TrkB is demonstrated. The A2AR-TrkB heteroreceptor complexes show a heterogeneous distribution within the rat dorsal hippocampus. High densities of the heteroreceptor complexes were observed in the pyramidal cell layers of CA1-CA3 regions and in the polymorphic layer of the dentate gyrus (DG). The stratum radiatum of the CA1-3 regions showed positive PLA signal in contrast to the oriens region. The molecular and granular layers of the DG also lacked significant densities of PLA positive heteroreceptor complexes, but subgranular zone showed some PLA positive cells. Their allosteric receptor-receptor interactions may significantly modulate BDNF signaling impacting on hippocampal plasticity which is impaired upon ageing.
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Affiliation(s)
- Michael Di Palma
- Department of Experimental and Clinical Medicine, Faculty of Medicine and Surgery, Università Politecnica Delle Marche, Ancona, Italy.
| | - Stefano Sartini
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Davide Lattanzi
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Riccardo Cuppini
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Mariana Pita-Rodriguez
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden; Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Málaga, Spain; Departamento de Diagnóstico Molecular, Centro de Neurociencias de Cuba, La Habana, Cuba
| | | | - Manuel Narvaez
- Universidad de Málaga, Instituto de Investigación Biomédica de Málaga, Málaga, Spain
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Dasiel O Borroto-Escuela
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy; Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Patrizia Ambrogini
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
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18
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Pandey SN, Kwatra M, Dwivedi DK, Choubey P, Lahkar M, Jangra A. 7,8-Dihydroxyflavone alleviated the high-fat diet and alcohol-induced memory impairment: behavioral, biochemical and molecular evidence. Psychopharmacology (Berl) 2020; 237:1827-1840. [PMID: 32206827 DOI: 10.1007/s00213-020-05502-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 03/05/2020] [Indexed: 12/12/2022]
Abstract
RATIONALE Alcoholism and obesity impart a deleterious impact on human health and affects the quality of life. Chronic consumption of alcohol and western diet has been reported to cause memory deficits. 7,8-dihydroxyflavone (7,8-DHF), a TrkB agonist, comprises antioxidant and anti-inflammatory properties in treating various neurological disorders. OBJECTIVES The current study was aimed to determine the protective effect and molecular mechanism of 7,8-DHF against alcohol and high-fat diet (HFD)-induced memory deficits in rats. METHODS The adult male Wistar rats were given alcohol (3-15%) and HFD ad libitum for 12 weeks in different experimental groups. 7,8-DHF (5 mg/kg) was intraperitoneally injected daily for the last 4 weeks (9th-12th week). RESULTS The alcohol and HFD administration caused cognitive impairment as evaluated through the Morris water maze (MWM) test in alcohol, HFD, and alcohol + HFD-fed animals. The last 4-week treatment of 7,8-DHF (5 mg/kg; i.p.) attenuated alcohol and HFD-induced memory loss. 7,8-DHF treatment also restored the glutathione (GSH) level along with attenuation of nitrite, malondialdehyde content (markers of oxidative and nitrosative stress), and reduction of the acetylcholinesterase activity in the hippocampus of alcohol and HFD-fed animals. Furthermore, the administration of 7,8-DHF caused downregulation of NF-κB, iNOS, and caspase-3 and upregulation of Nrf2, HO-1, and BDNF mRNA level in rat hippocampus. CONCLUSION 7,8-DHF administration conferred beneficial effects against alcohol and HFD-induced memory deficit via its unique antioxidant, anti-inflammatory, anti-apoptotic potential, along with the activation of TrkB/BDNF signaling pathway in the hippocampus.
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Affiliation(s)
- Surya Narayan Pandey
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, Assam, India
| | - Mohit Kwatra
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, Assam, India
| | - Durgesh Kumar Dwivedi
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, Assam, India
| | - Priyansha Choubey
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, Assam, India
| | - Mangala Lahkar
- Department of Pharmacology, Gauhati Medical College, Guwahati, Assam, India
| | - Ashok Jangra
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Guwahati, Assam, India. .,Department of Pharmacology, KIET School of Pharmacy, KIET Group of Institutions, Ghaziabad, Uttar Pradesh, India.
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19
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Characterising lipoteichoic acid as an in vitro model of acute neuroinflammation. Int Immunopharmacol 2020; 85:106619. [PMID: 32485352 DOI: 10.1016/j.intimp.2020.106619] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 04/29/2020] [Accepted: 05/17/2020] [Indexed: 01/12/2023]
Abstract
Toll-like receptor 2 (TLR2) is a primary sensor for pathogens, including those derived from gram-positive bacteria. It can also mediate the effects of endogenous inflammatory signals such as β-amyloid peptide (Aβ), thus promoting the microglial activation and subsequent neuronal dysfunction, characteristic of chronic neuroinflammatory conditions. More recently, a role for TLR2 has been proposed in the pathogenesis of disorders associated with acute inflammation, including anxiety and depression. The current study aims to characterise the acute effects of the TLR2 agonist lipoteichoic acid (LTA) on microglial activation and neuronal integrity, and to evaluate the influence of LTA exposure on sensitivity to the inflammation and neuronal dysfunction associated with Aβ. Using BV2 and N2a cells as an in vitro model, we highlight that acute exposure to LTA robustly promotes inflammatory cytokine and nitric oxide (NO) production in microglia but also in neurons, similar to that reported under longer-term and chronic inflammatory conditions. Moreover, we find that exposure to LTA can enhance sensitivity to subthreshold Aβ, promoting an 'M1'-like phenotype in microglia and provoking dysregulation of neuronal activity in acute hippocampal slices. Anti-inflammatory agents, including mimetics of brain-derived neurotrophic factor (BDNF), have proven effective at alleviating chronic neuroinflammatory complications. We further examined the effects of 7,8,3-trihydroxyflavone (7,8,3-THF), a small-molecule TrkB agonist, on LTA-induced microglial activation. We report that 7,8,3-THF can significantly ameliorate interleukin (IL)-6 and NO production in LTA-stimulated BV2 cells. Taken together, our findings offer support for exploration of TLR2 as a potential target for therapeutic intervention into acute neuroinflammatory conditions. Moreover we propose that exposure to gram-positive bacterial pathogens may promote sensitivity to the inflammatory changes characteristic of the aged brain.
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Li XX, Yang T, Wang N, Zhang LL, Liu X, Xu YM, Gao Q, Zhu XF, Guan YZ. 7,8-Dihydroxyflavone Attenuates Alcohol-Related Behavior in Rat Models of Alcohol Consumption via TrkB in the Ventral Tegmental Area. Front Neurosci 2020; 14:467. [PMID: 32508571 PMCID: PMC7248303 DOI: 10.3389/fnins.2020.00467] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 04/15/2020] [Indexed: 12/22/2022] Open
Abstract
Alcohol use disorder (AUD) is a ubiquitous substance use disorder in the world, of which neural mechanisms remain unclear. Alcohol consumption induces neuro-adaptations in the dopaminergic system originating from the ventral tegmental area (VTA), an important brain region for the reward function in AUD. Endogenous brain-derived neurotrophic factor (BDNF)-TrkB implicated in the development of neuroplasticity, including long-term potentiation of GABAergic synapses (LTP GABA ). We previously found that ethanol blocks LTP GABA in the VTA, either in vivo or in vitro. 7,8-dihydroflavone (7,8-DHF), a BDNF-mimicking small compound, was recently found to penetrate the blood-brain barrier to mimic the biological role of BDNF-TrkB. In this study, we demonstrate that repeated ethanol consumption (including intermittent and continuous ethanol exposure) results in low expression of BDNF in rat VTA. The amount of ethanol intake enhances significantly in rats with intermittent ethanol exposure after 72 h abstinence. Withdrawal signs emerge in rats with continuous ethanol exposure within 3 days after abstinence. Using behavioral tests, intraperitoneal injection of 7,8-DHF can reduce excessive ethanol consumption and preference as well as withdrawal signs in rats with repeated ethanol exposure. Interestingly, microinjection of K252a, an antagonist of TrkB, into the VTA blocks the effects of 7,8-DHF on ethanol-related behaviors. Furthermore, direct microinjection of BDNF into the VTA mimics the effect of 7,8-DHF on ethanol related behaviors. Taken together, 7,8-DHF attenuates alcohol-related behaviors in rats undergoing alcohol consumption via TrkB in the VTA. Our findings suggest BDNF-TrkB in VTA is a part of regulating signals for opposing neural adaptations in AUD, and 7,8-DHF may serve as a potential candidate for treating alcoholism.
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Affiliation(s)
- Xin-Xin Li
- Department of Physiology and Neurobiology, Mudanjiang Medical University, Mudanjiang, China
| | - Tao Yang
- Department of Physiology and Neurobiology, Mudanjiang Medical University, Mudanjiang, China
| | - Na Wang
- Department of Physiology and Neurobiology, Mudanjiang Medical University, Mudanjiang, China
| | - Li-Li Zhang
- Department of Physiology and Neurobiology, Mudanjiang Medical University, Mudanjiang, China
| | - Xing Liu
- Department of Physiology and Neurobiology, Mudanjiang Medical University, Mudanjiang, China
| | - Yan-Min Xu
- Department of Physiology and Neurobiology, Mudanjiang Medical University, Mudanjiang, China
| | - Qing Gao
- Department of Physiology and Neurobiology, Mudanjiang Medical University, Mudanjiang, China
| | - Xiao-Feng Zhu
- Department of Physiology and Neurobiology, Mudanjiang Medical University, Mudanjiang, China
| | - Yan-Zhong Guan
- Department of Physiology and Neurobiology, Mudanjiang Medical University, Mudanjiang, China
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21
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Benko J, Vranková S. Natural Psychoplastogens As Antidepressant Agents. Molecules 2020; 25:E1172. [PMID: 32150976 PMCID: PMC7179157 DOI: 10.3390/molecules25051172] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/28/2020] [Accepted: 03/02/2020] [Indexed: 12/22/2022] Open
Abstract
Increasing prevalence and burden of major depressive disorder presents an unavoidable problem for psychiatry. Existing antidepressants exert their effect only after several weeks of continuous treatment. In addition, their serious side effects and ineffectiveness in one-third of patients call for urgent action. Recent advances have given rise to the concept of psychoplastogens. These compounds are capable of fast structural and functional rearrangement of neural networks by targeting mechanisms previously implicated in the development of depression. Furthermore, evidence shows that they exert a potent acute and long-term positive effects, reaching beyond the treatment of psychiatric diseases. Several of them are naturally occurring compounds, such as psilocybin, N,N-dimethyltryptamine, and 7,8-dihydroxyflavone. Their pharmacology and effects in animal and human studies were discussed in this article.
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Affiliation(s)
- Jakub Benko
- Center of Experimental Medicine, Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, 841 04 Bratislava, Slovakia;
- Faculty of Medicine, Comenius University, 813 72 Bratislava, Slovakia
| | - Stanislava Vranková
- Center of Experimental Medicine, Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, 841 04 Bratislava, Slovakia;
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22
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Miyamoto N, Magami S, Inaba T, Ueno Y, Hira K, Kijima C, Nakajima S, Yamashiro K, Urabe T, Hattori N. The effects of A1/A2 astrocytes on oligodendrocyte linage cells against white matter injury under prolonged cerebral hypoperfusion. Glia 2020; 68:1910-1924. [DOI: 10.1002/glia.23814] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/19/2020] [Accepted: 02/21/2020] [Indexed: 12/30/2022]
Affiliation(s)
- Nobukazu Miyamoto
- Department of NeurologyJuntendo University School of Medicine Tokyo Japan
| | - Shunsuke Magami
- Department of NeurosurgeryJuntendo University School of Medicine Tokyo Japan
| | - Toshiki Inaba
- Department of NeurologyJuntendo University Urayasu Hospital Chiba Japan
| | - Yuji Ueno
- Department of NeurologyJuntendo University School of Medicine Tokyo Japan
| | - Kenichiro Hira
- Department of NeurologyJuntendo University School of Medicine Tokyo Japan
| | - Chikage Kijima
- Department of NeurologyJuntendo University School of Medicine Tokyo Japan
| | - Sho Nakajima
- Department of NeurologyJuntendo University School of Medicine Tokyo Japan
| | - Kazuo Yamashiro
- Department of NeurologyJuntendo University School of Medicine Tokyo Japan
| | - Takao Urabe
- Department of NeurologyJuntendo University Urayasu Hospital Chiba Japan
| | - Nobutaka Hattori
- Department of NeurologyJuntendo University School of Medicine Tokyo Japan
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Seese RR, Le AA, Wang K, Cox CD, Lynch G, Gall CM. A TrkB agonist and ampakine rescue synaptic plasticity and multiple forms of memory in a mouse model of intellectual disability. Neurobiol Dis 2020; 134:104604. [PMID: 31494285 PMCID: PMC7258745 DOI: 10.1016/j.nbd.2019.104604] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/26/2019] [Accepted: 09/04/2019] [Indexed: 12/20/2022] Open
Abstract
Fragile X syndrome (FXS) is associated with deficits in various types of learning, including those that require the hippocampus. Relatedly, hippocampal long-term potentiation (LTP) is impaired in the Fmr1 knockout (KO) mouse model of FXS. Prior research found that infusion of brain-derived neurotrophic factor (BDNF) rescues LTP in the KOs. Here, we tested if, in Fmr1 KO mice, up-regulating BDNF production or treatment with an agonist for BDNF's TrkB receptor restores synaptic plasticity and improves learning. In hippocampal slices, bath infusion of the TrkB agonist 7,8-dihydroxyflavone (7,8-DHF) completely restored otherwise impaired hippocampal field CA1 LTP of Fmr1 KOs without effect in wild types (WTs). Similarly, acute, semi-chronic, or chronic treatments with 7,8-DHF rescued a simple hippocampus-dependent form of spatial learning (object location memory: OLM) in Fmr1 KOs without effect in WTs. The agonist also restored object recognition memory, which depends on cortical regions. Semi-chronic, but not acute, treatment with the ampakine CX929, which up-regulates BDNF expression, lowered the training threshold for OLM in WT mice and rescued learning in the KOs. Positive results were also obtained in a test for social recognition. An mGluR5 antagonist did not improve learning. Quantification of synaptic immunolabeling demonstrated that 7,8-DHF and CX929 increase levels of activated TrkB at excitatory synapses. Moreover, CX929 induced a robust synaptic activation of the TrkB effector ERK1/2. These results suggest that enhanced synaptic BDNF signaling constitutes a plausible strategy for treating certain aspects of the cognitive disabilities associated with FXS.
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Affiliation(s)
- Ronald R Seese
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, United States of America
| | - Aliza A Le
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, United States of America
| | - Kathleen Wang
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, United States of America
| | - Conor D Cox
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, United States of America
| | - Gary Lynch
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, United States of America; Department of Psychiatry and Human Behavior, University of California, Irvine, CA, United States of America.
| | - Christine M Gall
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, United States of America; Department of Neurobiology and Behavior, University of California, Irvine, CA, United States of America.
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Timing of Treatment with the Flavonoid 7,8-DHF Critically Impacts on Its Effects on Learning and Memory in the Ts65Dn Mouse. Antioxidants (Basel) 2019; 8:antiox8060163. [PMID: 31174258 PMCID: PMC6617346 DOI: 10.3390/antiox8060163] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/29/2019] [Accepted: 06/05/2019] [Indexed: 12/12/2022] Open
Abstract
No therapies currently exist for intellectual disability in Down syndrome (DS). In view of its similarities with DS, including learning and memory (L&M) defects, the Ts65Dn mouse model of DS is widely used for the design of therapy. 7,8-dihydroxyflavone (7,8-DHF), a flavonoid that targets the tropomyosin-related kinase B (TrkB) receptor of brain-derived neurotrophic factor (BDNF), exerts positive effects in various brain disease models. Based on previous demonstration that administration of 7,8-DHF in the postnatal period P3-P15 restores hippocampal neurogenesis and spinogenesis, we sought to establish whether these effects translate into behavioral benefits after treatment cessation. We found that Ts65Dn mice treated with 7,8-DHF (5.0 mg/kg/day) during postnatal days P3-P15 did not show any L&M improvement at one month after treatment cessation, indicating that the effects of 7,8-DHF on the brain are ephemeral. Based on evidence that chronic treatment with 7,8-DHF in juvenile Ts65Dn mice restores L&M, we sought to establish whether a similar effect is elicited in adulthood. We found that Ts65Dn mice treated with 7,8-DHF (5.0 mg/kg/day) for about 40 days starting from 4 months of age did not show any improvement in L&M. The results suggest that timing of therapy with 7,8-DHF is a critical issue for attainment of positive effects on the brain.
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Matias I, Morgado J, Gomes FCA. Astrocyte Heterogeneity: Impact to Brain Aging and Disease. Front Aging Neurosci 2019; 11:59. [PMID: 30941031 PMCID: PMC6433753 DOI: 10.3389/fnagi.2019.00059] [Citation(s) in RCA: 222] [Impact Index Per Article: 44.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 03/01/2019] [Indexed: 12/13/2022] Open
Abstract
Astrocytes, one of the largest glial cell population in the central nervous system (CNS), play a key function in several events of brain development and function, such as synapse formation and function, control of neurotransmitters release and uptake, production of trophic factors and control of neuronal survival. Initially described as a homogenous population, several evidences have pointed that astrocytes are highly heterogeneous, both morphologically and functionally, within the same region, and across different brain regions. Recent findings suggest that the heterogeneity in the expression profile of proteins involved in astrocyte function may predict the selective vulnerability of brain regions to specific diseases, as well as to the age-related cognitive decline. However, the molecular mechanisms underlying these changes, either in aging as well as in brain disease are scarce. Neuroinflammation, a hallmark of several neurodegenerative diseases and aging, is reported to have a dubious impact on glial activation, as these cells release pro- and anti-inflammatory cytokines and chemokines, anti-oxidants, free radicals, and neurotrophic factors. Despite the emerging evidences supporting that reactive astrocytes have a duality in their phenotype, neurotoxic or neuroprotective properties, depending on the age and stimuli, the underlying mechanisms of their activation, cellular interplays and the impact of regional astrocyte heterogeneity are still a matter of discussion. In this review article, we will summarize recent findings on astrocyte heterogeneity and phenotypes, as well as their likely impact for the brain function during aging and neural diseases. We will focus on the molecules and mechanisms triggered by astrocyte to control synapse formation in different brain regions. Finally, we will discuss new evidences on how the modulation of astrocyte phenotype and function could impact the synaptic deficits and glial dysfunction present in aging and pathological states.
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Affiliation(s)
- Isadora Matias
- Laboratory of Cellular Neurobiology, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Juliana Morgado
- Laboratory of Cellular Neurobiology, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Flávia Carvalho Alcantara Gomes
- Laboratory of Cellular Neurobiology, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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Aydin-Abidin S, Abidin İ. 7,8-Dihydroxyflavone potentiates ongoing epileptiform activity in mice brain slices. Neurosci Lett 2019; 703:25-31. [PMID: 30880161 DOI: 10.1016/j.neulet.2019.03.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 02/22/2019] [Accepted: 03/09/2019] [Indexed: 12/14/2022]
Abstract
In the central nervous system, Tropomyosin-receptor-kinase B (TrkB) signaling is involved in neuronal survival, differentiation as well as in regulation of synaptic transmission and excitability. As its powerful potential to modulate neuronal functions, TrkB pathway is an attractive target for novel drugs and treatment of common neurological disorders. 7,8-Dihydroxyflavone (DHF), a TrkB receptor agonist, has similar properties with neurotrophin Brain Derived Neurotropic Factor (BDNF). DHF is reported to have a number of beneficial effects in neuroprotection, against depression and improving learning and memory. However, the outcome of acute application of DHF on the excitability of neuronal circuits is not clear. Especially the effects of DHF on synchronized epileptiform activity are not known. In this study, we investigated whether DHF induces epileptiform activity in brain slices and DHF has any effect on already initiated epileptiform discharges. We used acute horizontal hippocampal-entorhinal cortex slices obtained from 30 to 35 days of mice. Extracellular field potential recordings were obtained from entorhinal cortex (EC) and hippocampus CA1 region. DHF did not initiate any epileptiform activity or abnormal discharges. However, DHF increased the frequency of 4 aminopyridine (4AP) induced ictal and interictal events in both EC and CA1. The duration of induced ictal charges were also prolonged upon DHF application. In a number of slices, both EC and CA1, DHF led to ictogenesis. These results suggest that the acute activation of TrkB by DHF has a powerful potential on synchronized neuronal discharges which should be considered in future therapeutical approaches.
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Affiliation(s)
- Selcen Aydin-Abidin
- Department of Biophysics, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey.
| | - İsmail Abidin
- Department of Biophysics, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey
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Suto T, Kato D, Obata H, Saito S. Tropomyosin Receptor Kinase B Receptor Activation in the Locus Coeruleus Restores Impairment of Endogenous Analgesia at a Late Stage Following Nerve Injury in Rats. THE JOURNAL OF PAIN 2018; 20:600-609. [PMID: 30529695 DOI: 10.1016/j.jpain.2018.11.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 11/08/2018] [Accepted: 11/28/2018] [Indexed: 12/16/2022]
Abstract
A rat model of neuropathic pain at 6 weeks after spinal nerve ligation (SNL6w) exhibits both mechanical hypersensitivity and impaired noxious stimuli-induced analgesia (NSIA). Repeated treatment with antidepressants can produce antihypersensitivity and restore NSIA. To examine the involvement of a brain-derived neurotrophic factor-mediated mechanism, a tropomyosin receptor kinase B (TrkB) agonist, 7,8-dihydroxyflavone (DHF), was administered to SNL6w rats (5 mg/kg/d for 5 days). Mechanical hypersensitivity was evaluated using the von Frey filament test and paw pressure test. NSIA was examined by measuring the change in the hind paw withdrawal threshold 30 minutes after painful stimulation induced by capsaicin injection into the fore paw. Changes in the concentrations of glutamate and GABA in the locus coeruleus area were measured by in vivo microdialysis. DHF treatment did not affect mechanical hypersensitivity, although it restored NSIA by reducing GABA release in response to the fore paw capsaicin injection. DHF treatment did not alter the baseline concentration of glutamate or GABA. These findings suggest that DHF treatment restored the stimuli-response activity of the locus coeruleus without affecting the tonic activity of the locus coeruleus. The brain-derived neurotrophic factor-TkB signaling is also involved in the NSIA-restoring effect of amitriptyline. PERSPECTIVE: This article demonstrates that repeated treatment with TrkB agonist, DHF, restored endogenous analgesia. Repeated amitriptyline treatment showed similar effect via TrkB-mediated mechanisms, and the effect may be independent from the effect of antihypersensitivity. This effect of TrkB activation is promising for patients with chronic pain with impaired descending inhibition.
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Affiliation(s)
- Takashi Suto
- Department of Anesthesiology, Gunma University Graduate School of Medicine, Gunma, Japan.
| | - Daiki Kato
- Department of Anesthesiology, Gunma University Graduate School of Medicine, Gunma, Japan
| | - Hideaki Obata
- Department of Anesthesiology and Center for Pain Management, Fukushima Medical University, Fukushima, Japan
| | - Shigeru Saito
- Department of Anesthesiology, Gunma University Graduate School of Medicine, Gunma, Japan
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Kobayashi K, Suzuki H. Synapse-selective rapid potentiation of hippocampal synaptic transmission by 7,8-dihydroxyflavone. Neuropsychopharmacol Rep 2018; 38:197-203. [PMID: 30280523 PMCID: PMC7292275 DOI: 10.1002/npr2.12033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 08/29/2018] [Accepted: 09/05/2018] [Indexed: 12/25/2022] Open
Abstract
AIM The identification of 7,8-dihydroxyflavone (DHF) as a small molecule agonist for tropomyosin-related kinase B (TrkB) facilitated understanding of the role of TrkB signaling in regulating higher brain functions. DHF can penetrate the blood-brain barrier after systemic administration and changes the performance of cognitive and emotional behavioral tasks. However, it is poorly understood how DHF modulates neuronal functions at cellular levels. Aiming to understand the cellular basis underlying DHF-induced modifications of the brain functions, we examined the effects of DHF on the hippocampal excitatory synaptic transmission. METHODS Field excitatory postsynaptic potentials were recorded using hippocampal slices prepared from adult male mice. Effects of bath-applied DHF on the synaptic efficacy were examined. RESULTS We found that DHF induced robust synaptic potentiation at the mossy fiber to CA3 synapse. DHF had minimal effects at other hippocampal excitatory synapses or at immature mossy fiber synapse in juvenile mice. The TrkB receptor blockers K252a and ANA-12 did not affect the DHF-induced synaptic potentiation. Drug screening revealed that relatively low concentrations of 2-aminoethoxydiphenylborane blocked the DHF-induced synaptic potentiation. CONCLUSION Our results demonstrate that DHF selectively potentiates hippocampal mossy fiber synaptic transmission via a TrkB receptor-independent mechanism. This novel neuromodulatory effect of DHF may influence higher brain functions by itself or together with the activation of the TrkB receptor. The rapid induction of the potentiation implies its potential importance in the acute behavioral effects of DHF.
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Affiliation(s)
- Katsunori Kobayashi
- Department of Pharmacology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Hidenori Suzuki
- Department of Pharmacology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
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29
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Psychedelics Promote Structural and Functional Neural Plasticity. Cell Rep 2018; 23:3170-3182. [PMID: 29898390 PMCID: PMC6082376 DOI: 10.1016/j.celrep.2018.05.022] [Citation(s) in RCA: 520] [Impact Index Per Article: 86.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 04/03/2018] [Accepted: 05/07/2018] [Indexed: 12/12/2022] Open
Abstract
Atrophy of neurons in the prefrontal cortex (PFC) plays a key role in the pathophysiology of depression and related disorders. The ability to promote both structural and functional plasticity in the PFC has been hypothesized to underlie the fast-acting antidepressant properties of the dissociative anesthetic ketamine. Here, we report that, like ketamine, serotonergic psychedelics are capable of robustly increasing neuritogenesis and/or spinogenesis both in vitro and in vivo. These changes in neuronal structure are accompanied by increased synapse number and function, as measured by fluorescence microscopy and electrophysiology. The structural changes induced by psychedelics appear to result from stimulation of the TrkB, mTOR, and 5-HT2A signaling pathways and could possibly explain the clinical effectiveness of these compounds. Our results underscore the therapeutic potential of psychedelics and, importantly, identify several lead scaffolds for medicinal chemistry efforts focused on developing plasticity-promoting compounds as safe, effective, and fast-acting treatments for depression and related disorders.
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Aytan N, Choi JK, Carreras I, Crabtree L, Nguyen B, Lehar M, Blusztajn JK, Jenkins BG, Dedeoglu A. Protective effects of 7,8-dihydroxyflavone on neuropathological and neurochemical changes in a mouse model of Alzheimer's disease. Eur J Pharmacol 2018; 828:9-17. [PMID: 29510124 DOI: 10.1016/j.ejphar.2018.02.045] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 02/13/2018] [Accepted: 02/28/2018] [Indexed: 12/26/2022]
Abstract
Interest in brain-derived neurotrophic factor (BDNF) was greatly enhanced when it was recognized that its expression is reduced in neurodegenerative disorders, especially in Alzheimer's disease (AD). BDNF signaling through the TrkB receptor has a central role in promoting synaptic transmission, synaptogenesis, and facilitating synaptic plasticity making the BDNF-TrkB signaling pathway an attractive candidate for targeted therapies. Here we investigated the early effect of the small molecule TrkB agonist, 7,8 dihydroxyflavone (7,8-DHF), on AD-related pathology, dendritic arborization, synaptic density, and neurochemical changes in the 5xFAD mouse model of AD. We treated 5xFAD mice with 7,8-DHF for 2 months beginning at 1 month of age. We found that, in this model of AD, 7,8-DHF treatment decreased cortical Aβ plaque deposition and protected cortical neurons against reduced dendritic arbor complexity but had no significant impact on the density of dendritic spines. In addition 7,8-DHF treatment protected against hippocampal increase in the level of choline-containing compounds and glutamate loss, but had no significant impact on hippocampal neurogenesis.
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Affiliation(s)
- Nurgul Aytan
- Department of Veterans Affairs, VA Boston Healthcare System, Boston, MA 02130, USA; Department of Neurology Boston University School of Medicine, Boston, MA 02118, USA; Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
| | - Ji-Kyung Choi
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
| | - Isabel Carreras
- Department of Veterans Affairs, VA Boston Healthcare System, Boston, MA 02130, USA; Department of Biochemistry Boston University School of Medicine, Boston, MA 02118, USA.
| | - Leah Crabtree
- Department of Veterans Affairs, VA Boston Healthcare System, Boston, MA 02130, USA; Department of Neurology Boston University School of Medicine, Boston, MA 02118, USA; University of Exeter Medical School, Devon EX4 4QJ, UK.
| | - Brian Nguyen
- Department of Veterans Affairs, VA Boston Healthcare System, Boston, MA 02130, USA; Department of Neurology Boston University School of Medicine, Boston, MA 02118, USA.
| | - Margaret Lehar
- Department of Veterans Affairs, VA Boston Healthcare System, Boston, MA 02130, USA; Department of Neurology Boston University School of Medicine, Boston, MA 02118, USA.
| | | | - Bruce G Jenkins
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
| | - Alpaslan Dedeoglu
- Department of Veterans Affairs, VA Boston Healthcare System, Boston, MA 02130, USA; Department of Neurology Boston University School of Medicine, Boston, MA 02118, USA; Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
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Perez-Rando M, Castillo-Gomez E, Bueno-Fernandez C, Nacher J. The TrkB agonist 7,8-dihydroxyflavone changes the structural dynamics of neocortical pyramidal neurons and improves object recognition in mice. Brain Struct Funct 2018; 223:2393-2408. [PMID: 29500536 DOI: 10.1007/s00429-018-1637-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 02/20/2018] [Indexed: 01/17/2023]
Abstract
BDNF and its receptor TrkB have important roles in neurodevelopment, neural plasticity, learning, and memory. Alterations in TrkB expression have been described in different CNS disorders. Therefore, drugs interacting with TrkB, specially agonists, are promising therapeutic tools. Among them, the recently described 7,8-dihydroxyflavone (DHF), an orally bioactive compound, has been successfully tested in animal models of these diseases. Recent studies have shown the influence of this drug on the structure of pyramidal neurons, specifically on dendritic spine density. However, there is no information yet on how DHF may alter the structural dynamics of these neurons (i.e., real-time study of the addition/elimination of dendritic spines and axonal boutons). To gain knowledge on these effects of DHF, we have performed a real-time analysis of spine and axonal dynamics in pyramidal neurons of barrel cortex, using cranial windows and 2-photon microscopy during a chronic oral treatment with this drug. After confirming TrkB expression in these neurons, we found that DHF increased the gain rates of spines and axonal boutons, as well as improved object recognition memory. These results help to understand how the activation of the BDNF-TrkB system can improve basic behavioral tasks through changes in the structural dynamics of pyramidal neurons. Moreover, they highlight DHF as a promising therapeutic vector for certain brain disorders in which this system is altered.
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Affiliation(s)
- Marta Perez-Rando
- Neurobiology Unit, Cell Biology Department, Program in Neurosciences and Interdisciplinary Research Structure for Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Dr. Moliner, 50, Burjassot, 46100, Spain
| | - Esther Castillo-Gomez
- Neurobiology Unit, Cell Biology Department, Program in Neurosciences and Interdisciplinary Research Structure for Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Dr. Moliner, 50, Burjassot, 46100, Spain. .,CIBERSAM: Spanish National Network for Research in Mental Health, Valencia, Spain. .,Department of Medicine, School of Medical Sciences, Universitat Jaume I, Vicente Sos Banyat s/n, 12071, Castellón de la Plana, Spain.
| | - Clara Bueno-Fernandez
- Neurobiology Unit, Cell Biology Department, Program in Neurosciences and Interdisciplinary Research Structure for Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Dr. Moliner, 50, Burjassot, 46100, Spain
| | - Juan Nacher
- Neurobiology Unit, Cell Biology Department, Program in Neurosciences and Interdisciplinary Research Structure for Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Dr. Moliner, 50, Burjassot, 46100, Spain. .,CIBERSAM: Spanish National Network for Research in Mental Health, Valencia, Spain. .,Fundación Investigación Hospital Clínico de Valencia, INCLIVA, Valencia, Spain.
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The prodrug of 7,8-dihydroxyflavone development and therapeutic efficacy for treating Alzheimer's disease. Proc Natl Acad Sci U S A 2018; 115:578-583. [PMID: 29295929 DOI: 10.1073/pnas.1718683115] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The BDNF mimetic compound 7,8-dihydroxyflavone (7,8-DHF), a potent small molecular TrkB agonist, displays prominent therapeutic efficacy against Alzheimer's disease (AD). However, 7,8-DHF has only modest oral bioavailability and a moderate pharmacokinetic (PK) profile. To alleviate these preclinical obstacles, we used a prodrug strategy for elevating 7,8-DHF oral bioavailability and brain exposure, and found that the optimal prodrug R13 has favorable properties and dose-dependently reverses the cognitive defects in an AD mouse model. We synthesized a large number of 7,8-DHF derivatives via ester or carbamate group modification on the catechol ring in the parent compound. Using in vitro absorption, distribution, metabolism, and excretion assays, combined with in vivo PK studies, we identified a prodrug, R13, that prominently up-regulates 7,8-DHF PK profiles. Chronic oral administration of R13 activated TrkB signaling and prevented Aβ deposition in 5XFAD AD mice, inhibiting the pathological cleavage of APP and Tau by AEP. Moreover, R13 inhibited the loss of hippocampal synapses and ameliorated memory deficits in a dose-dependent manner. These results suggest that the prodrug R13 is an optimal therapeutic agent for treating AD.
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Pandey RP, Parajuli P, Pokhrel AR, Sohng JK. Biosynthesis of novel 7,8-dihydroxyflavone glycoside derivatives and in silico
study of their effects on BACE1 inhibition. Biotechnol Appl Biochem 2017; 65:128-137. [DOI: 10.1002/bab.1570] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 06/03/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Ramesh Prasad Pandey
- Department of Life Science and Biochemical Engineering; SunMoon University; Asan-si Chungnam Republic of Korea
- Department of BT-Convergent Pharmaceutical Engineering; SunMoon University; Asan-si Chungnam Republic of Korea
| | - Prakash Parajuli
- Department of Life Science and Biochemical Engineering; SunMoon University; Asan-si Chungnam Republic of Korea
| | - Anaya Raj Pokhrel
- Department of Life Science and Biochemical Engineering; SunMoon University; Asan-si Chungnam Republic of Korea
| | - Jae Kyung Sohng
- Department of Life Science and Biochemical Engineering; SunMoon University; Asan-si Chungnam Republic of Korea
- Department of BT-Convergent Pharmaceutical Engineering; SunMoon University; Asan-si Chungnam Republic of Korea
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Matias I, Diniz LP, Buosi A, Neves G, Stipursky J, Gomes FCA. Flavonoid Hesperidin Induces Synapse Formation and Improves Memory Performance through the Astrocytic TGF-β1. Front Aging Neurosci 2017; 9:184. [PMID: 28659786 PMCID: PMC5468382 DOI: 10.3389/fnagi.2017.00184] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 05/24/2017] [Indexed: 11/24/2022] Open
Abstract
Synapse formation and function are critical events for the brain function and cognition. Astrocytes are active participants in the control of synapses during development and adulthood, but the mechanisms underlying astrocyte synaptogenic potential only began to be better understood recently. Currently, new drugs and molecules, including the flavonoids, have been studied as therapeutic alternatives for modulation of cognitive processes in physiological and pathological conditions. However, the cellular targets and mechanisms of actions of flavonoids remain poorly elucidated. In the present study, we investigated the effects of hesperidin on memory and its cellular and molecular targets in vivo and in vitro, by using a short-term protocol of treatment. The novel object recognition test (NOR) was used to evaluate memory performance of mice intraperitoneally treated with hesperidin 30 min before the training and again before the test phase. The direct effects of hesperidin on synapses and astrocytes were also investigated using in vitro approaches. Here, we described hesperidin as a new drug able to improve memory in healthy adult mice by two main mechanisms: directly, by inducing synapse formation and function between hippocampal and cortical neurons; and indirectly, by enhancing the synaptogenic ability of cortical astrocytes mainly due to increased secretion of transforming growth factor beta-1 (TGF-β1) by these cells. Our data reinforces the known neuroprotective effect of hesperidin and, by the first time, characterizes its synaptogenic action on the central nervous system (CNS), pointing astrocytes and TGF-β1 signaling as new cellular and molecular targets of hesperidin. Our work provides not only new data regarding flavonoid’s actions on the CNS but also shed light on possible new therapeutic alternative based on astrocyte biology.
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Affiliation(s)
- Isadora Matias
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
| | - Luan P Diniz
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
| | - Andrea Buosi
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
| | - Gilda Neves
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
| | - Joice Stipursky
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
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Wang X, Romine JL, Gao X, Chen J. Aging impairs dendrite morphogenesis of newborn neurons and is rescued by 7, 8-dihydroxyflavone. Aging Cell 2017; 16:304-311. [PMID: 28256073 PMCID: PMC5334527 DOI: 10.1111/acel.12553] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2016] [Indexed: 11/28/2022] Open
Abstract
All aging individuals will develop some degree of decline in cognitive capacity as time progresses. The molecular and cellular mechanisms leading to age‐related cognitive decline are still not fully understood. Through our previous research, we discovered that active neural progenitor cells selectively become more quiescent in response to aging, thus leading to the decline of neurogenesis in the aged hippocampus. Here, we further find that aging impaired dendrite development of newborn neurons. Currently, no effective approach is available to increase neurogenesis or promote dendrite development of newborn neurons in the aging brain. We found that systemically administration of 7, 8‐dihydroxyflavone (DHF), a small molecule imitating brain‐derived neurotrophic factor (BDNF), significantly enhanced dendrite length in the newborn neurons, while it did not promote survival of immature neurons, in the hippocampus of 12‐month‐old mice. DHF‐promoted dendrite development of newborn neurons in the hippocampus may enhance their function in the aging animal leading to a possible improvement in cognition.
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Affiliation(s)
- Xiaoting Wang
- Spinal Cord and Brain Injury Research Group; Stark Neuroscience Research Institute; Indianapolis IN 46202 USA
- Department of Neurological Surgery; Indiana University School of Medicine; Indianapolis IN 46202 USA
| | - Jennifer Lynn Romine
- Spinal Cord and Brain Injury Research Group; Stark Neuroscience Research Institute; Indianapolis IN 46202 USA
- Department of Neurological Surgery; Indiana University School of Medicine; Indianapolis IN 46202 USA
| | - Xiang Gao
- Spinal Cord and Brain Injury Research Group; Stark Neuroscience Research Institute; Indianapolis IN 46202 USA
- Department of Neurological Surgery; Indiana University School of Medicine; Indianapolis IN 46202 USA
| | - Jinhui Chen
- Spinal Cord and Brain Injury Research Group; Stark Neuroscience Research Institute; Indianapolis IN 46202 USA
- Department of Neurological Surgery; Indiana University School of Medicine; Indianapolis IN 46202 USA
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Tan Y, Nie S, Zhu W, Liu F, Guo H, Chu J, Cao XB, Jiang X, Zhang Y, Li Y. 7,8-Dihydroxyflavone Ameliorates Cognitive Impairment by Inhibiting Expression of Tau Pathology in ApoE-Knockout Mice. Front Aging Neurosci 2016; 8:287. [PMID: 27965573 PMCID: PMC5126466 DOI: 10.3389/fnagi.2016.00287] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 11/14/2016] [Indexed: 11/13/2022] Open
Abstract
7,8-Dihydroxyflavone (7,8-DHF), a tyrosine kinase B agonist that mimics the neuroprotective properties of brain-derived neurotrophic factor, which can not efficiently deliver into the brain, has been reported to be useful in ameliorating cognitive impairment in many diseases. Researches have indicated that apolipoprotein E-knockout (ApoE-KO) mouse was associated with cognitive alteration via various mechanisms. Our present study investigated the possible mechanisms of cognitive impairment of ApoE-KO mouse fed with western type diet and the protective effects of 7,8-DHF in improving spatial learning and memory in ApoE-KO mouse. Five-weeks-old ApoE-KO mice and C57BL/6 mice were chronically treated with 7,8-DHF (with a dosage of 5 mg/kg) or vehicles orally for 25 weeks, and then subjected to Morris water maze at the age of 30 weeks to evaluate the cognitive performances. Afterward, histology analysis and western blotting were performed. Spatial learning and memory deficits were observed in ApoE-KO mice, which were consistent with higher expression of active-asparaginyl endopeptidase (active-AEP) as well as AEP-derived truncated tau N368 compared with normal group. In addition to that, long-term treatment of 7,8-DHF dramatically ameliorated cognitive decline in ApoE-KO mice, accompanied by the activation in phosphorylated protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β) pathway and down-regulated expression of tau S396 and PHF-tau (phosphorylated tau at ser396 and ser404 epitope). These findings suggested that cognitive impairment of ApoE-KO mouse might associate with tau pathology and 7,8-DHF could activate AKT and then phosphorylate its downstream molecule to inhibit expression of abnormal tau, meanwhile, 7,8-DHF could reduce the expression of active-AEP and then inhibit production of truncated tau N368.
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Affiliation(s)
- Yang Tan
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan, China
| | - Shuke Nie
- Department of Neurology, Renmin Hospital of Wuhan University Wuhan, China
| | - Wende Zhu
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan, China
| | - Fang Liu
- Department of Medicine, LuoHu Chronic Disease Control and Cure Hospital Shenzhen, China
| | - Hailong Guo
- Department of Pharmacy, The Eighth Affiliated Hospital of Sun Yat-sen University Shenzhen, China
| | - Jiewen Chu
- Department of Pharmacy, The Eighth Affiliated Hospital of Sun Yat-sen University Shenzhen, China
| | - Xue B Cao
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan, China
| | - Xingjun Jiang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan, China
| | - Yunjian Zhang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan, China
| | - Yuzhen Li
- Department of Pharmacy, The Eighth Affiliated Hospital of Sun Yat-sen University Shenzhen, China
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Pitts EG, Taylor JR, Gourley SL. Prefrontal cortical BDNF: A regulatory key in cocaine- and food-reinforced behaviors. Neurobiol Dis 2016; 91:326-35. [PMID: 26923993 PMCID: PMC4913044 DOI: 10.1016/j.nbd.2016.02.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 02/20/2016] [Accepted: 02/24/2016] [Indexed: 12/21/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) affects synaptic plasticity and neural structure and plays key roles in learning and memory processes. Recent evidence also points to important, yet complex, roles for BDNF in rodent models of cocaine abuse and addiction. Here we examine the role of prefrontal cortical (PFC) BDNF in reward-related decision making and behavioral sensitivity to, and responding for, cocaine. We focus on BDNF within the medial and orbital PFC, its regulation by cocaine during early postnatal development and in adulthood, and how BDNF in turn influences responding for drug reinforcement, including in reinstatement models. When relevant, we draw comparisons and contrasts with experiments using natural (food) reinforcers. We also summarize findings supporting, or refuting, the possibility that BDNF in the medial and orbital PFC regulate the development and maintenance of stimulus-response habits. Further investigation could assist in the development of novel treatment approaches for cocaine use disorders.
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Affiliation(s)
- Elizabeth G Pitts
- Graduate Program in Neuroscience, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Jane R Taylor
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States; Interdepartmental Neuroscience Program, Department of Psychology, Yale University, New Haven, CT, United States
| | - Shannon L Gourley
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, United States; Graduate Program in Neuroscience, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States.
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38
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Yang P, Leu D, Ye K, Srinivasan C, Fike JR, Huang TT. Cognitive impairments following cranial irradiation can be mitigated by treatment with a tropomyosin receptor kinase B agonist. Exp Neurol 2016; 279:178-186. [PMID: 26946222 PMCID: PMC4933026 DOI: 10.1016/j.expneurol.2016.02.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 02/10/2016] [Accepted: 02/26/2016] [Indexed: 12/18/2022]
Abstract
Brain radiotherapy is frequently used successfully to treat brain tumors. However, radiotherapy is often associated with declines in short-term and long-term memory, learning ability, and verbal fluency. We previously identified a downregulation of the brain-derived neurotrophic factor (BDNF) following cranial irradiation in experimental animals. In the present study, we investigated whether targeting the BDNF high affinity receptor, tropomysin receptor kinase B (TrkB), could mitigate radiation-induced cognitive deficits. After irradiation, chronic treatment with a small molecule TrkB agonist, 7,8-dihydroxyflavone (DHF) in mice led to enhanced activation of TrkB and its downstream targets ERK and AKT, both important factors in neuronal development. DHF treatment significantly restored spatial, contextual, and working memory, and the positive effects persisted for at least 3months after completion of the treatment. Consistent with preservation of cognitive functions, chronic DHF treatment mitigated radiation-induced suppression of hippocampal neurogenesis. Spine density and major components of the excitatory synapses, including glutamate receptors and postsynaptic density protein 95 (PSD-95), were also maintained at normal levels by DHF treatment after irradiation. Taken together, our results show that chronic treatment with DHF after irradiation significantly mitigates radiation-induced cognitive defects. This is achieved most likely by preservation of hippocampal neurogenesis and synaptic plasticity.
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Affiliation(s)
- Phillip Yang
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA; Palo Alto Veterans Institute for Research, Palo Alto, CA 94304, USA
| | - David Leu
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA; Palo Alto Veterans Institute for Research, Palo Alto, CA 94304, USA
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, USA
| | - Chandra Srinivasan
- Department of Chemistry and Biochemistry, California State University Fullerton, CA 92831, USA
| | - John R Fike
- Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA
| | - Ting-Ting Huang
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA; Geriatric Research, Education, and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA.
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39
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Matias I, Buosi AS, Gomes FCA. Functions of flavonoids in the central nervous system: Astrocytes as targets for natural compounds. Neurochem Int 2016; 95:85-91. [DOI: 10.1016/j.neuint.2016.01.009] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 01/28/2016] [Accepted: 01/29/2016] [Indexed: 01/16/2023]
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40
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Zhao S, Gao X, Dong W, Chen J. The Role of 7,8-Dihydroxyflavone in Preventing Dendrite Degeneration in Cortex After Moderate Traumatic Brain Injury. Mol Neurobiol 2016; 53:1884-1895. [PMID: 25801526 PMCID: PMC5441052 DOI: 10.1007/s12035-015-9128-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 02/22/2015] [Indexed: 01/24/2023]
Abstract
Our previous research showed that traumatic brain injury (TBI) induced by controlled cortical impact (CCI) not only causes massive cell death, but also results in extensive dendrite degeneration in those spared neurons in the cortex. Cell death and dendrite degeneration in the cortex may contribute to persistent cognitive, sensory, and motor dysfunction. There is still no approach available to prevent cells from death and dendrites from degeneration following TBI. When we treated the animals with a small molecule, 7,8-dihydroxyflavone (DHF) that mimics the function of brain-derived neurotrophic factor (BDNF) through provoking TrkB activation reduced dendrite swellings in the cortex. DHF treatment also prevented dendritic spine loss after TBI. Functional analysis showed that DHF improved rotarod performance on the third day after surgery. These results suggest that although DHF treatment did not significantly reduced neuron death, it prevented dendrites from degenerating and protected dendritic spines against TBI insult. Consequently, DHF can partially improve the behavior outcomes after TBI.
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Affiliation(s)
- Shu Zhao
- Department of Histology and Embryology, Southern Medical University, Guangzhou, China
| | - Xiang Gao
- Spinal Cord and Brain Injury Research Group, Indiana University, 950 W. Walnut Street, Indianapolis, IN, 46202, USA
- Stark Neuroscience Research Institute, Indiana University, 950 W. Walnut Street, Indianapolis, IN, 46202, USA
- Department of Neurosurgery, Indiana University, 950 W. Walnut Street, Indianapolis, IN, 46202, USA
| | - Weiren Dong
- Department of Histology and Embryology, Southern Medical University, Guangzhou, China.
- , 1838 North Guangzhou Blvd, Guangzhou, 510515, China.
| | - Jinhui Chen
- Spinal Cord and Brain Injury Research Group, Indiana University, 950 W. Walnut Street, Indianapolis, IN, 46202, USA.
- Stark Neuroscience Research Institute, Indiana University, 950 W. Walnut Street, Indianapolis, IN, 46202, USA.
- Department of Neurosurgery, Indiana University, 950 W. Walnut Street, Indianapolis, IN, 46202, USA.
- Indiana University, School of Medicine, 980 W. Walnut Street, R3, Indianapolis, IN, 46202, USA.
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41
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Liu C, Chan CB, Ye K. 7,8-dihydroxyflavone, a small molecular TrkB agonist, is useful for treating various BDNF-implicated human disorders. Transl Neurodegener 2016; 5:2. [PMID: 26740873 PMCID: PMC4702337 DOI: 10.1186/s40035-015-0048-7] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 12/29/2015] [Indexed: 12/21/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) regulates a variety of biological processes predominantly via binding to the transmembrane receptor tyrosine kinase TrkB. It is a potential therapeutic target in numerous neurological, mental and metabolic disorders. However, the lack of efficient means to deliver BDNF into the body imposes an insurmountable hurdle to its clinical application. To address this challenge, we initiated a cell-based drug screening to search for small molecules that act as the TrkB agonist. 7,8-Dihydroxyflavone (7,8-DHF) is our first reported small molecular TrkB agonist, which has now been extensively validated in various biochemical and cellular systems. Though binding to the extracellular domain of TrkB, 7,8-DHF triggers TrkB dimerization to induce the downstream signaling. Notably, 7,8-DHF is orally bioactive that can penetrate the brain blood barrier (BBB) to exert its neurotrophic activities in the central nervous system. Numerous reports suggest 7,8-DHF processes promising therapeutic efficacy in various animal disease models that are related to deficient BDNF signaling. In this review, we summarize our current knowledge on the binding activity and specificity, structure-activity relationship, pharmacokinetic and metabolism, and the pre-clinical efficacy of 7,8-DHF against some human diseases.
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Affiliation(s)
- Chaoyang Liu
- School of Information and Safety Engineering, Zhongnan University of Economics and Law, Wuhan, 430073 P.R. China
| | - Chi Bun Chan
- Department of Physiology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young Blvd., Oklahoma City, OK 73104 USA
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322 USA
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42
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Gao L, Tian M, Zhao HY, Xu QQ, Huang YM, Si QC, Tian Q, Wu QM, Hu XM, Sun LB, McClintock SM, Zeng Y. TrkB activation by 7, 8-dihydroxyflavone increases synapse AMPA subunits and ameliorates spatial memory deficits in a mouse model of Alzheimer's disease. J Neurochem 2015; 136:620-36. [DOI: 10.1111/jnc.13432] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 09/20/2015] [Accepted: 11/06/2015] [Indexed: 01/11/2023]
Affiliation(s)
- Lei Gao
- Brain and Cognitive Dysfunction Research Center; School of Medicine; Wuhan University of Science and Technology; Wuhan China
| | - Mi Tian
- Brain and Cognitive Dysfunction Research Center; School of Medicine; Wuhan University of Science and Technology; Wuhan China
| | - Hong-Yun Zhao
- The Fifth Ward of Neurology Rehabilitation Center; Hangzhou Armed Police Hospital; Hangzhou China
| | - Qian-Qian Xu
- Brain and Cognitive Dysfunction Research Center; School of Medicine; Wuhan University of Science and Technology; Wuhan China
| | - Yu-Ming Huang
- Brain and Cognitive Dysfunction Research Center; School of Medicine; Wuhan University of Science and Technology; Wuhan China
| | - Qun-Cao Si
- Brain and Cognitive Dysfunction Research Center; School of Medicine; Wuhan University of Science and Technology; Wuhan China
| | - Qing Tian
- Brain and Cognitive Dysfunction Research Center; School of Medicine; Wuhan University of Science and Technology; Wuhan China
| | - Qing-Ming Wu
- Brain and Cognitive Dysfunction Research Center; School of Medicine; Wuhan University of Science and Technology; Wuhan China
| | - Xia-Min Hu
- Brain and Cognitive Dysfunction Research Center; School of Medicine; Wuhan University of Science and Technology; Wuhan China
| | - Li-Bo Sun
- Brain and Cognitive Dysfunction Research Center; School of Medicine; Wuhan University of Science and Technology; Wuhan China
| | - Shawn M. McClintock
- Brain and Cognitive Dysfunction Research Center; School of Medicine; Wuhan University of Science and Technology; Wuhan China
- Division of Brain Stimulation and Neurophysiology; Department of Psychiatry and Behavioral Sciences; Duke University School of Medicine; Durham North Carolina USA
- Department of Psychiatry; UT Southwestern Medical Center; Dallas Texas USA
| | - Yan Zeng
- Brain and Cognitive Dysfunction Research Center; School of Medicine; Wuhan University of Science and Technology; Wuhan China
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43
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Xu J, Kurup P, Baguley TD, Foscue E, Ellman JA, Nairn AC, Lombroso PJ. Inhibition of the tyrosine phosphatase STEP61 restores BDNF expression and reverses motor and cognitive deficits in phencyclidine-treated mice. Cell Mol Life Sci 2015; 73:1503-14. [PMID: 26450419 DOI: 10.1007/s00018-015-2057-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 09/02/2015] [Accepted: 09/28/2015] [Indexed: 02/07/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) and STriatal-Enriched protein tyrosine Phosphatase 61 (STEP61) have opposing functions in the brain, with BDNF supporting and STEP61 opposing synaptic strengthening. BDNF and STEP61 also exhibit an inverse pattern of expression in a number of brain disorders, including schizophrenia (SZ). NMDAR antagonists such as phencyclidine (PCP) elicit SZ-like symptoms in rodent models and unaffected individuals, and exacerbate psychotic episodes in SZ. Here we characterize the regulation of BDNF expression by STEP61, utilizing PCP-treated cortical culture and PCP-treated mice. PCP-treated cortical neurons showed both an increase in STEP61 levels and a decrease in BDNF expression. The reduction in BDNF expression was prevented by STEP61 knockdown or use of the STEP inhibitor, TC-2153. The PCP-induced increase in STEP61 expression was associated with the inhibition of CREB-dependent BDNF transcription. Similarly, both genetic and pharmacologic inhibition of STEP prevented the PCP-induced reduction in BDNF expression in vivo and normalized PCP-induced hyperlocomotion and cognitive deficits. These results suggest a mechanism by which STEP61 regulates BDNF expression, with implications for cognitive functioning in CNS disorders.
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Affiliation(s)
- Jian Xu
- Child Study Center, Yale University, 230 S Frontage Rd., New Haven, CT, 06520, USA
| | - Pradeep Kurup
- Child Study Center, Yale University, 230 S Frontage Rd., New Haven, CT, 06520, USA
| | - Tyler D Baguley
- Department of Chemistry, Yale University, 225 Prospect St., New Haven, CT, 06520, USA
| | - Ethan Foscue
- Child Study Center, Yale University, 230 S Frontage Rd., New Haven, CT, 06520, USA
| | - Jonathan A Ellman
- Department of Chemistry, Yale University, 225 Prospect St., New Haven, CT, 06520, USA
| | - Angus C Nairn
- Department of Psychiatry, Yale University, 300 George St., New Haven, CT, 06520, USA
| | - Paul J Lombroso
- Child Study Center, Yale University, 230 S Frontage Rd., New Haven, CT, 06520, USA. .,Department of Psychiatry, Yale University, 300 George St., New Haven, CT, 06520, USA. .,Department of Neurobiology, Yale University, 333 Cedar St., New Haven, CT, 06520, USA.
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44
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Janssen CI, Zerbi V, Mutsaers MP, Jochems M, Vos CA, Vos JO, Berg BM, van Tol EA, Gross G, Jouni ZE, Heerschap A, Kiliaan AJ. Effect of perinatally supplemented flavonoids on brain structure, circulation, cognition, and metabolism in C57BL/6J mice. Neurochem Int 2015; 89:157-69. [DOI: 10.1016/j.neuint.2015.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 04/27/2015] [Accepted: 05/04/2015] [Indexed: 01/15/2023]
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45
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Xu J, Kurup P, Azkona G, Baguley TD, Saavedra A, Nairn AC, Ellman JA, Pérez-Navarro E, Lombroso PJ. Down-regulation of BDNF in cell and animal models increases striatal-enriched protein tyrosine phosphatase 61 (STEP61 ) levels. J Neurochem 2015; 136:285-94. [PMID: 26316048 DOI: 10.1111/jnc.13295] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 08/12/2015] [Accepted: 08/13/2015] [Indexed: 12/23/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) regulates synaptic strengthening and memory consolidation, and altered BDNF expression is implicated in a number of neuropsychiatric and neurodegenerative disorders. BDNF potentiates N-methyl-D-aspartate receptor function through activation of Fyn and ERK1/2. STriatal-Enriched protein tyrosine Phosphatase (STEP) is also implicated in many of the same disorders as BDNF but, in contrast to BDNF, STEP opposes the development of synaptic strengthening. STEP-mediated dephosphorylation of the NMDA receptor subunit GluN2B promotes internalization of GluN2B-containing NMDA receptors, while dephosphorylation of the kinases Fyn, Pyk2, and ERK1/2 leads to their inactivation. Thus, STEP and BDNF have opposing functions. In this study, we demonstrate that manipulation of BDNF expression has a reciprocal effect on STEP61 levels. Reduced BDNF signaling leads to elevation of STEP61 both in BDNF(+/-) mice and after acute BDNF knockdown in cortical cultures. Moreover, a newly identified STEP inhibitor reverses the biochemical and motor abnormalities in BDNF(+/-) mice. In contrast, increased BDNF signaling upon treatment with a tropomyosin receptor kinase B agonist results in degradation of STEP61 and a subsequent increase in the tyrosine phosphorylation of STEP substrates in cultured neurons and in mouse frontal cortex. These findings indicate that BDNF-tropomyosin receptor kinase B signaling leads to degradation of STEP61 , while decreased BDNF expression results in increased STEP61 activity. A better understanding of the opposing interaction between STEP and BDNF in normal cognitive functions and in neuropsychiatric disorders will hopefully lead to better therapeutic strategies. Altered expression of BDNF and STEP61 has been implicated in several neurological disorders. BDNF and STEP61 are known to regulate synaptic strengthening, but in opposite directions. Here, we report that reduced BDNF signaling leads to elevation of STEP61 both in BDNF(+/-) mice and after acute BDNF knockdown in cortical cultures. In contrast, activation of TrkB receptor results in the degradation of STEP61 and reverses hyperlocomotor activity in BDNF(+/-) mice. Moreover, inhibition of STEP61 by TC-2153 is sufficient to enhance the Tyr phosphorylation of STEP substrates and also reverses hyperlocomotion in BDNF(+/-) mice. These findings give us a better understanding of the regulation of STEP61 by BDNF in normal cognitive functions and in neuropsychiatric disorders.
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Affiliation(s)
- Jian Xu
- Yale University School of Medicine, New Haven, Connecticut, USA
| | - Pradeep Kurup
- Yale University School of Medicine, New Haven, Connecticut, USA
| | - Garikoitz Azkona
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Spain
| | - Tyler D Baguley
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
| | - Ana Saavedra
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Spain
| | - Angus C Nairn
- Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jonathan A Ellman
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
| | - Esther Pérez-Navarro
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Spain
| | - Paul J Lombroso
- Yale University School of Medicine, New Haven, Connecticut, USA
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46
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Exploring the Molecular Interactions of 7,8-Dihydroxyflavone and Its Derivatives with TrkB and VEGFR2 Proteins. Int J Mol Sci 2015; 16:21087-108. [PMID: 26404256 PMCID: PMC4613243 DOI: 10.3390/ijms160921087] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 08/21/2015] [Accepted: 08/26/2015] [Indexed: 11/16/2022] Open
Abstract
7,8-dihydroxyflavone (7,8-DHF) is a TrkB receptor agonist, and treatment with this flavonoid derivative brings about an enhanced TrkB phosphorylation and promotes downstream cellular signalling. Flavonoids are also known to exert an inhibitory effect on the vascular endothelial growth factor receptor (VEGFR) family of tyrosine kinase receptors. VEGFR2 is one of the important receptors involved in the regulation of vasculogenesis and angiogenesis and has also been implicated to exhibit various neuroprotective roles. Its upregulation and uncontrolled activity is associated with a range of pathological conditions such as age-related macular degeneration and various proliferative disorders. In this study, we investigated molecular interactions of 7,8-DHF and its derivatives with both the TrkB receptor as well as VEGFR2. Using a combination of molecular docking and computational mapping tools involving molecular dynamics approaches we have elucidated additional residues and binding energies involved in 7,8-DHF interactions with the TrkB Ig2 domain and VEGFR2. Our investigations have revealed for the first time that 7,8-DHF has dual biochemical action and its treatment may have divergent effects on the TrkB via its extracellular Ig2 domain and on the VEGFR2 receptor through the intracellular kinase domain. Contrary to its agonistic effects on the TrkB receptor, 7,8-DHF was found to downregulate VEGFR2 phosphorylation both in 661W photoreceptor cells and in retinal tissue.
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47
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The mechanisms of action of flavonoids in the brain: Direct versus indirect effects. Neurochem Int 2015; 89:126-39. [PMID: 26260546 DOI: 10.1016/j.neuint.2015.08.002] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 08/04/2015] [Accepted: 08/05/2015] [Indexed: 02/01/2023]
Abstract
The projected increase in the incidence of dementia in the population highlights the urgent need for a more comprehensive understanding of how different aspects of lifestyle, in particular exercise and diet, may affect neural function and consequent cognitive performance throughout the life course. In this regard, flavonoids, found in a variety of fruits, vegetables and derived beverages, have been identified as a group of promising bioactive compounds capable of influencing different aspects of brain function, including cerebrovascular blood flow and synaptic plasticity, both resulting in improvements in learning and memory in mammalian species. However, the precise mechanisms by which flavonoids exert these actions are yet to be fully established, although accumulating data indicate an ability to interact with neuronal receptors and kinase signaling pathways which are key to neuronal activation and communication and synaptic strengthening. Alternatively or concurrently, there is also compelling evidence derived from human clinical studies suggesting that flavonoids can positively affect peripheral and cerebrovascular blood flow, which may be an indirect effective mechanism by which dietary flavonoids can impact on brain health and cognition. The current review examines the beneficial effects of flavonoids on both human and animal brain function and attempts to address and link direct and indirect actions of flavonoids and their derivatives within the central nervous system (CNS).
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Yang YJ, Chen HB, Wei B, Wang W, Zhou PL, Zhan JQ, Hu MR, Yan K, Hu B, Yu B. Cognitive decline is associated with reduced surface GluR1 expression in the hippocampus of aged rats. Neurosci Lett 2015; 591:176-181. [DOI: 10.1016/j.neulet.2015.02.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 01/27/2015] [Accepted: 02/13/2015] [Indexed: 10/24/2022]
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Petzold A, Psotta L, Brigadski T, Endres T, Lessmann V. Chronic BDNF deficiency leads to an age-dependent impairment in spatial learning. Neurobiol Learn Mem 2015; 120:52-60. [PMID: 25724412 DOI: 10.1016/j.nlm.2015.02.009] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 02/07/2015] [Accepted: 02/17/2015] [Indexed: 10/23/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is a crucial mediator of neural plasticity and, consequently, of memory formation. In hippocampus-dependent learning tasks BDNF also seems to play an essential role. However, there are conflicting results concerning the spatial learning ability of aging BDNF(+/-) mice in the Morris water maze paradigm. To evaluate the effect of chronic BDNF deficiency in the hippocampus on spatial learning throughout life, we conducted a comprehensive study to test differently aged BDNF(+/-) mice and their wild type littermates in the Morris water maze and to subsequently quantify their hippocampal BDNF protein levels as well as expression levels of TrkB receptors. We observed an age-dependent learning deficit in BDNF(+/-) animals, starting at seven months of age, despite stable hippocampal BDNF protein expression and continual decline of TrkB receptor expression throughout aging. Furthermore, we detected a positive correlation between hippocampal BDNF protein levels and learning performance during the probe trial in animals that showed a good learning performance during the long-term memory test.
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Affiliation(s)
- Anne Petzold
- Institute for Physiology, Medical Faculty, Otto-von-Guericke University, Leipziger Str. 44, 39120 Magdeburg, Germany
| | - Laura Psotta
- Institute for Physiology, Medical Faculty, Otto-von-Guericke University, Leipziger Str. 44, 39120 Magdeburg, Germany
| | - Tanja Brigadski
- Institute for Physiology, Medical Faculty, Otto-von-Guericke University, Leipziger Str. 44, 39120 Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Thomas Endres
- Institute for Physiology, Medical Faculty, Otto-von-Guericke University, Leipziger Str. 44, 39120 Magdeburg, Germany.
| | - Volkmar Lessmann
- Institute for Physiology, Medical Faculty, Otto-von-Guericke University, Leipziger Str. 44, 39120 Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany
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Tian M, Zeng Y, Hu Y, Yuan X, Liu S, Li J, Lu P, Sun Y, Gao L, Fu D, Li Y, Wang S, McClintock SM. 7, 8-Dihydroxyflavone induces synapse expression of AMPA GluA1 and ameliorates cognitive and spine abnormalities in a mouse model of fragile X syndrome. Neuropharmacology 2015; 89:43-53. [DOI: 10.1016/j.neuropharm.2014.09.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Revised: 08/28/2014] [Accepted: 09/04/2014] [Indexed: 01/20/2023]
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