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Pornnoppadol G, Bond LG, Lucas MJ, Zupancic JM, Kuo YH, Zhang B, Greineder CF, Tessier PM. Bispecific antibody shuttles targeting CD98hc mediate efficient and long-lived brain delivery of IgGs. Cell Chem Biol 2024; 31:361-372.e8. [PMID: 37890480 PMCID: PMC10922565 DOI: 10.1016/j.chembiol.2023.09.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 06/22/2023] [Accepted: 09/18/2023] [Indexed: 10/29/2023]
Abstract
The inability of antibodies to penetrate the blood-brain barrier (BBB) is a key limitation to their use in diverse applications. One promising strategy is to deliver IgGs using a bispecific BBB shuttle, which involves fusing an IgG to a second affinity ligand that engages a cerebrovascular endothelial target and facilitates transport across the BBB. Nearly all prior efforts have focused on shuttles that target transferrin receptor (TfR-1) despite inherent delivery and safety challenges. Here, we report bispecific antibody shuttles that engage CD98hc, the heavy chain of the large neutral amino acid transporter (LAT1), and efficiently transport IgGs into the brain. Notably, CD98hc shuttles lead to much longer-lived brain retention of IgGs than TfR-1 shuttles while enabling more specific targeting due to limited CD98hc engagement in the brain parenchyma, which we demonstrate for IgGs that either agonize a neuronal receptor (TrkB) or target other endogenous cell-surface proteins on neurons and astrocytes.
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Affiliation(s)
- Ghasidit Pornnoppadol
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Layne G Bond
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA; Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Michael J Lucas
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jennifer M Zupancic
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yun-Huai Kuo
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Boya Zhang
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Colin F Greineder
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Emergency Medicine, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Peter M Tessier
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, USA; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA; Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
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Numakawa T, Kajihara R. Involvement of brain-derived neurotrophic factor signaling in the pathogenesis of stress-related brain diseases. Front Mol Neurosci 2023; 16:1247422. [PMID: 37781095 PMCID: PMC10537938 DOI: 10.3389/fnmol.2023.1247422] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 08/31/2023] [Indexed: 10/03/2023] Open
Abstract
Neurotrophins including brain-derived neurotrophic factor, BDNF, have critical roles in neuronal differentiation, cell survival, and synaptic function in the peripheral and central nervous system. It is well known that a variety of intracellular signaling stimulated by TrkB, a high-affinity receptor for BDNF, is involved in the physiological and pathological neuronal aspects via affecting cell viability, synaptic function, neurogenesis, and cognitive function. As expected, an alteration of the BDNF/TrkB system is suspected to be one of the molecular mechanisms underlying cognitive decline in cognitive diseases and mental disorders. Recent evidence has also highlighted a possible link between the alteration of TrkB signaling and chronic stress. Furthermore, it has been demonstrated that downregulation of the BDNF/TrkB system and chronic stress have a role in the pathogenesis of Alzheimer's disease (AD) and mental disorders. In this review, we introduce current evidence showing a close relationship between the BDNF/TrkB system and the development of cognition impairment in stress-related disorders, and the possible contribution of the upregulation of the BDNF/TrkB system in a therapeutic approach against these brain diseases.
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Affiliation(s)
- Tadahiro Numakawa
- Department of Cell Modulation, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Ryutaro Kajihara
- Department of Cell Modulation, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
- Department of Biomedical Laboratory Sciences, Faculty of Life Science, Kumamoto University, Kumamoto, Japan
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3
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Lee JM, Choi YJ, Yoo MC, Yeo SG. Central Facial Nervous System Biomolecules Involved in Peripheral Facial Nerve Injury Responses and Potential Therapeutic Strategies. Antioxidants (Basel) 2023; 12:antiox12051036. [PMID: 37237902 DOI: 10.3390/antiox12051036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/20/2023] [Accepted: 04/29/2023] [Indexed: 05/28/2023] Open
Abstract
Peripheral facial nerve injury leads to changes in the expression of various neuroactive substances that affect nerve cell damage, survival, growth, and regeneration. In the case of peripheral facial nerve damage, the injury directly affects the peripheral nerves and induces changes in the central nervous system (CNS) through various factors, but the substances involved in these changes in the CNS are not well understood. The objective of this review is to investigate the biomolecules involved in peripheral facial nerve damage so as to gain insight into the mechanisms and limitations of targeting the CNS after such damage and identify potential facial nerve treatment strategies. To this end, we searched PubMed using keywords and exclusion criteria and selected 29 eligible experimental studies. Our analysis summarizes basic experimental studies on changes in the CNS following peripheral facial nerve damage, focusing on biomolecules that increase or decrease in the CNS and/or those involved in the damage, and reviews various approaches for treating facial nerve injury. By establishing the biomolecules in the CNS that change after peripheral nerve damage, we can expect to identify factors that play an important role in functional recovery from facial nerve damage. Accordingly, this review could represent a significant step toward developing treatment strategies for peripheral facial palsy.
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Affiliation(s)
- Jae-Min Lee
- Department of Otorhinolaryngology, Head & Neck Surgery, College of Medicine, Kyung Hee University Medical Center, Seoul 02447, Republic of Korea
| | - You Jung Choi
- Department of Otorhinolaryngology, Head & Neck Surgery, College of Medicine, Kyung Hee University Medical Center, Seoul 02447, Republic of Korea
| | - Myung Chul Yoo
- Department of Physical Medicine & Rehabilitation, College of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Seung Geun Yeo
- Department of Otorhinolaryngology, Head & Neck Surgery, College of Medicine, Kyung Hee University Medical Center, Seoul 02447, Republic of Korea
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4
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Pornnoppadol G, Bond LG, Lucas MJ, Zupancic JM, Kuo YH, Zhang B, Greineder CF, Tessier PM. Bispecific antibody shuttles targeting CD98hc mediate efficient and long-lived brain delivery of IgGs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.29.538811. [PMID: 37162883 PMCID: PMC10168297 DOI: 10.1101/2023.04.29.538811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The inability of antibodies and other biologics to penetrate the blood-brain barrier (BBB) is a key limitation to their use in diagnostic, imaging, and therapeutic applications. One promising strategy is to deliver IgGs using a bispecific BBB shuttle, which involves fusing an IgG with a second affinity ligand that engages a cerebrovascular endothelial target and facilitates transport across the BBB. Nearly all prior efforts have focused on the transferrin receptor (TfR-1) as the prototypical endothelial target despite inherent delivery and safety challenges. Here we report bispecific antibody shuttles that engage CD98hc (also known as 4F2 and SLC3A2), the heavy chain of the large neutral amino acid transporter (LAT1), and efficiently transport IgGs into the brain parenchyma. Notably, CD98hc shuttles lead to much longer-lived brain retention of IgGs than TfR-1 shuttles while enabling more specific brain targeting due to limited CD98hc engagement in the brain parenchyma. We demonstrate the broad utility of the CD98hc shuttles by reformatting three existing IgGs as CD98hc bispecific shuttles and delivering them to the mouse brain parenchyma that either agonize a neuronal receptor (TrkB) or target other endogenous antigens on specific types of brain cells (neurons and astrocytes).
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5
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Muscular Swedish mutant APP-to-Brain axis in the development of Alzheimer's disease. Cell Death Dis 2022; 13:952. [PMID: 36357367 PMCID: PMC9649614 DOI: 10.1038/s41419-022-05378-4] [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: 04/12/2022] [Revised: 10/25/2022] [Accepted: 10/26/2022] [Indexed: 11/12/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia. Notably, patients with AD often suffer from severe sarcopenia. However, their direct link and relationship remain poorly understood. Here, we generated a mouse line, TgAPPsweHSA, by crossing LSL (LoxP-STOP-LoxP)-APPswe with HSA-Cre mice, which express APPswe (Swedish mutant APP) selectively in skeletal muscles. Examining phenotypes in TgAPPsweHSA mice showed not only sarcopenia-like deficit, but also AD-relevant hippocampal inflammation, impairments in adult hippocampal neurogenesis and blood brain barrier (BBB), and depression-like behaviors. Further studies suggest that APPswe expression in skeletal muscles induces senescence and expressions of senescence-associated secretory phenotypes (SASPs), which include inflammatory cytokines and chemokines; but decreases growth factors, such as PDGF-BB and BDNF. These changes likely contribute to the systemic and hippocampal inflammation, deficits in neurogenesis and BBB, and depression-like behaviors, revealing a link of sarcopenia with AD, and uncovering an axis of muscular APPswe to brain in AD development.
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Lu Z, Wang H, Gu J, Gao F. Association between abnormal brain oscillations and cognitive performance in patients with bipolar disorder; Molecular mechanisms and clinical evidence. Synapse 2022; 76:e22247. [PMID: 35849784 DOI: 10.1002/syn.22247] [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: 02/20/2022] [Revised: 05/23/2022] [Accepted: 06/20/2022] [Indexed: 11/10/2022]
Abstract
Brain oscillations have gained great attention in neuroscience during recent decades as functional building blocks of cognitive-sensory processes. Research has shown that oscillations in "alpha," "beta," "gamma," "delta," and "theta" frequency windows are highly modified in brain pathology, including in patients with cognitive impairment like bipolar disorder (BD). The study of changes in brain oscillations can provide fundamental knowledge for exploring neurophysiological biomarkers in cognitive impairment. The present article reviews findings from the role and molecular basis of abnormal neural oscillation and synchronization in the symptoms of patients with BD. An overview of the results clearly demonstrates that, in cognitive-sensory processes, resting and evoked/event-related electroencephalogram (EEG) spectra in the delta, theta, alpha, beta, and gamma bands are abnormally changed in patients with BD showing psychotic features. Abnormal oscillations have been found to be associated with several neural dysfunctions and abnormalities contributing to BD, including abnormal GABAergic neurotransmission signaling, hippocampal cell discharge, abnormal hippocampal neurogenesis, impaired cadherin and synaptic contact-based cell adhesion processes, extended lateral ventricles, decreased prefrontal cortical gray matter, and decreased hippocampal volume. Mechanistically, impairment in calcium voltage-gated channel subunit alpha1 I, neurotrophic tyrosine receptor kinase proteins, genes involved in brain neurogenesis and synaptogenesis like WNT3 and ACTG2, genes involved in the cell adhesion process like CDH12 and DISC1, and gamma-aminobutyric acid (GABA) signaling have been reported as the main molecular contributors to the abnormalities in resting-state low-frequency oscillations in BD patients. Findings also showed the association of impaired synaptic connections and disrupted membrane potential with abnormal beta/gamma oscillatory activity in patients with BD. Of note, the synaptic GABA neurotransmitter has been found to be a fundamental requirement for the occurrence of long-distance synchronous gamma oscillations necessary for coordinating the activity of neural networks between various brain regions. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Zhou Lu
- Department of Neurosurgery, The Affiliated People's Hospital of NingBo University, NingBo, 315000, China
| | - Huixiao Wang
- Department of Neurosurgery, The Affiliated People's Hospital of NingBo University, NingBo, 315000, China
| | - Jiajie Gu
- Department of Neurosurgery, The Affiliated People's Hospital of NingBo University, NingBo, 315000, China
| | - Feng Gao
- Department of Neurosurgery, The Affiliated People's Hospital of NingBo University, NingBo, 315000, China
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Schirò G, Iacono S, Ragonese P, Aridon P, Salemi G, Balistreri CR. A Brief Overview on BDNF-Trk Pathway in the Nervous System: A Potential Biomarker or Possible Target in Treatment of Multiple Sclerosis? Front Neurol 2022; 13:917527. [PMID: 35911894 PMCID: PMC9332890 DOI: 10.3389/fneur.2022.917527] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 06/01/2022] [Indexed: 01/09/2023] Open
Abstract
The growing incidence of neurodegenerative disorders in our populations is leading the research to identify potential biomarkers and targets for facilitating their early management and treatments. Biomarkers represent the crucial indicators of both physiological and pathological processes. Specific changes in molecular and cellular mechanisms of physiological processes result in biochemical alterations at systemic level, which can give us comprehensive information regarding the nature of any disease. In addition, any disease biomarker should be specific and reliable, able to consent of distinguishing the physiological condition of a tissue, organ, or system from disease, and be diverse among the various diseases, or subgroups or phenotypes of them. Accordingly, biomarkers can predict chances for diseases, facilitate their early diagnosis, and set guidelines for the development of new therapies for treating diseases and disease-making process. Here, we focus our attention on brain neurotrophic factor (BDNF)–tropomyosin receptor kinase (Trk) pathway, describing its multiple roles in the maintenance of central nervous system (CNS) health, as well as its implication in the pathogenesis of multiple sclerosis (MS). In addition, we also evidence the features of such pathway, which make of it a potential MS biomarker and therapeutic target.
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Affiliation(s)
- Giuseppe Schirò
- Unit of Neurology, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
| | - Salvatore Iacono
- Unit of Neurology, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
| | - Paolo Ragonese
- Unit of Neurology, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
- Paolo Ragonese
| | - Paolo Aridon
- Unit of Neurology, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
| | - Giuseppe Salemi
- Unit of Neurology, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
- Giuseppe Salemi
| | - Carmela Rita Balistreri
- Cellular and Molecular Laboratory, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, Palermo, Italy
- *Correspondence: Carmela Rita Balistreri ; orcid.org/0000-0002-5393-1007
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Xu X, Liang Z, Lin Y, Rao J, Lin F, Yang Z, Wang R, Chen C. Comparing the Efficacy and Safety of Cell Transplantation for Spinal Cord Injury: A Systematic Review and Bayesian Network Meta-Analysis. Front Cell Neurosci 2022; 16:860131. [PMID: 35444516 PMCID: PMC9013778 DOI: 10.3389/fncel.2022.860131] [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] [Received: 01/22/2022] [Accepted: 03/11/2022] [Indexed: 11/13/2022] Open
Abstract
ObjectiveTo compare the safety and effectiveness of transplanted cells from different sources for spinal cord injury (SCI).DesignA systematic review and Bayesian network meta-analysis.Data SourcesMedline, Embase, and the Cochrane Central Register of Controlled Trials.Study SelectionWe included randomized controlled trials, case–control studies, and case series related to cell transplantation for SCI patients, that included at least 1 of the following outcome measures: American Spinal Cord Injury Association (ASIA) Impairment Scale (AIS grade), ASIA motor score, ASIA sensory score, the Functional Independence Measure score (FIM), International Association of Neurorestoratology Spinal Cord Injury Functional Rating Scale (IANR-SCIFRS), or adverse events. Follow-up data were analyzed at 6 and 12 months.ResultsForty-four eligible trials, involving 1,266 patients, investigated 6 treatments: olfactory ensheathing cells (OECs), neural stem cells/ neural progenitor cells (NSCs), mesenchymal stem cells (MSCs), Schwann cells, macrophages, and combinations of cells (MSCs plus Schwann cells). Macrophages improved the AIS grade at 12 months (mean 0.42, 95% credible interval: 0–0.91, low certainty) and FIM score at 12 months (42.83, 36.33–49.18, very low certainty). MSCs improved the AIS grade at 6 months (0.42, 0.15–0.73, moderate certainty), the motor score at 6 months (4.43, 0.91–7.78, moderate certainty), light touch at 6 (10.01, 5.81–13.88, moderate certainty) and 12 months (11.48, 6.31–16.64, moderate certainty), pinprick score at 6 (14.54, 9.76–19.46, moderate certainty) and 12 months (12.48, 7.09–18.12, moderate certainty), and the IANR-SCIFRS at 6 (3.96, 0.62–6.97, moderate certainty) and 12 months (5.54, 2.45–8.42, moderate certainty). OECs improved the FIM score at 6 months (9.35, 1.71–17.00, moderate certainty). No intervention improved the motor score significantly at 12 months. The certainty of other interventions was low or very low. Overall, the number of adverse events associated with transplanted cells was low.ConclusionsPatients with SCI who receive transplantation of macrophages, MSCs, NSCs, or OECs may have improved disease prognosis. MSCs are the primary recommendations. Further exploration of the mechanism of cell transplantation in the treatment of SCI, transplantation time window, transplantation methods, and monitoring of the number of transplanted cells and cell survival is needed.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO/#recordDetails, identifier: CRD 42021282043.
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Sahu K, Langeh U, Singh C, Singh A. Crosstalk between anticancer drugs and mitochondrial functions. CURRENT RESEARCH IN PHARMACOLOGY AND DRUG DISCOVERY 2021; 2:100047. [PMID: 34909674 PMCID: PMC8663961 DOI: 10.1016/j.crphar.2021.100047] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/12/2021] [Accepted: 08/17/2021] [Indexed: 01/12/2023] Open
Abstract
Chemotherapy is an important component of cancer treatment, which has side effects like vomiting, peripheral neuropathy, and numerous organ toxicity but the most significant outcomes of chemotherapy are cognitive impairment, which is mainly referred to as chemobrain or CICI (chemotherapy-induced cognitive impairment). It is characterized by difficulty with language, concentrating, processing speed, learning, and memory, as it affects the hippocampus areas of the brain. Mitochondrial dysfunction and oxidative stress are one of the major mechanisms causing chemobrain. The generation of reactive oxygen species (byproducts of oxidative phosphorylation) mainly occurs in mitochondria that play a prominent role in the induction of oxidative stress. The homeostasis of ROS in the mitochondria is maintained by mitochondrial antioxidant mechanism via enzymes like catalase, glutathione, and superoxide dismutase. Lungs and breast cancer are the two most common types of cancer, which are the most leading cancers in the world with about 4.18 million cases. In this review we exposed the current knowledge regarding chemotherapy-induced oxidative stress and mitochondrial dysfunction to cause cognitive impairment.We especially focused on the antineoplastic agent (ADRIAMYCIN, CYCLOPHOSPHAMIDE), platinum group agent CISPLATIN, antimetabolite agents (METHOTREXATE), and nitrogen mustard agent (CARMUSTINE) which increase oxidative stress and inflammatory markers in the PNS (peripheral nervous system) as well as the central nervous system. We also highlight the behavioural and functional changes in the brain.
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Affiliation(s)
- Kuleshwar Sahu
- Department of Pharmacology, ISF College of Pharmacy, Moga, 142001, Punjab, India
| | - Urvashi Langeh
- Department of Pharmacology, ISF College of Pharmacy, Moga, 142001, Punjab, India
| | - Charan Singh
- Department of Pharmaceutics, ISF College of Pharmacy, Moga, 142001, Punjab, India
| | - Arti Singh
- Department of Pharmacology, ISF College of Pharmacy, Moga, 142001, Punjab, India
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10
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Lau CG, Zhang H, Murthy VN. Deletion of TrkB in parvalbumin interneurons alters cortical neural dynamics. J Cell Physiol 2021; 237:949-964. [PMID: 34491578 PMCID: PMC8810709 DOI: 10.1002/jcp.30571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 08/20/2021] [Accepted: 08/23/2021] [Indexed: 11/25/2022]
Abstract
Signaling by neurotrophins such as the brain‐derived neurotrophic factor (BDNF) is known to modulate development of interneurons, but the circuit effects of this modulation remain unclear. Here, we examined the impact of deleting TrkB, a BDNF receptor, in parvalbumin‐expressing (PV) interneurons on the balance of excitation and inhibition (E‐I) in cortical circuits. In the mouse olfactory cortex, TrkB deletion impairs multiple aspects of PV neuronal function including synaptic excitation, intrinsic excitability, and the innervation pattern of principal neurons. Impaired PV cell function resulted in aberrant spiking patterns in principal neurons in response to stimulation of sensory inputs. Surprisingly, dampened PV neuronal function leads to a paradoxical decrease in overall excitability in cortical circuits. Our study demonstrates that, by modulating PV circuit plasticity and development, TrkB plays a critical role in shaping the evoked pattern of activity in a cortical network.
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Affiliation(s)
- Chunyue Geoffrey Lau
- Department of Neuroscience, City University of Hong Kong, Hong Kong, China.,Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, Massachusetts, USA
| | - Huiqi Zhang
- Department of Neuroscience, City University of Hong Kong, Hong Kong, China
| | - Venkatesh N Murthy
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, Massachusetts, USA
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Pregnolato F, Cova L, Doretti A, Bardelli D, Silani V, Bossolasco P. Exosome microRNAs in Amyotrophic Lateral Sclerosis: A Pilot Study. Biomolecules 2021; 11:biom11081220. [PMID: 34439885 PMCID: PMC8394507 DOI: 10.3390/biom11081220] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/11/2021] [Accepted: 08/13/2021] [Indexed: 12/11/2022] Open
Abstract
The pathogenesis of amyotrophic lateral sclerosis (ALS), a lethal neurodegenerative disease, remains undisclosed. Mutations in ALS related genes have been identified, albeit the majority of cases are unmutated. Clinical pathology of ALS suggests a prion-like cell-to-cell diffusion of the disease possibly mediated by exosomes, small endocytic vesicles involved in the propagation of RNA molecules and proteins. In this pilot study, we focused on exosomal microRNAs (miRNAs), key regulators of many signaling pathways. We analyzed serum-derived exosomes from ALS patients in comparison with healthy donors. Exosomes were obtained by a commercial kit. Purification of miRNAs was performed using spin column chromatography and RNA was reverse transcribed into cDNA. All samples were run on the miRCURY LNATM Universal RT miRNA PCR Serum/Plasma Focus panel. An average of 29 miRNAs were detectable per sample. The supervised analysis did not identify any statistically significant difference among the groups indicating that none of the miRNA of our panel has a strong pathological role in ALS. However, selecting samples with the highest miRNA content, six biological processes shared across miRNAs through the intersection of the GO categories were identified. Our results, combined to those reported in the literature, indicated that further investigation is needed to elucidate the role of exosome-derived miRNA in ALS.
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Affiliation(s)
- Francesca Pregnolato
- Experimental Laboratory of Immunological and Rheumatologic Researches, Istituto Auxologico Italiano, IRCCS, Cusano Milanino, 20095 Milan, Italy;
| | - Lidia Cova
- Department of Neurology-Stroke Unit and Laboratory of Neuroscience, Istituto Auxologico Italiano, IRCCS, 20149 Milan, Italy; (L.C.); (A.D.); (D.B.); (V.S.)
| | - Alberto Doretti
- Department of Neurology-Stroke Unit and Laboratory of Neuroscience, Istituto Auxologico Italiano, IRCCS, 20149 Milan, Italy; (L.C.); (A.D.); (D.B.); (V.S.)
| | - Donatella Bardelli
- Department of Neurology-Stroke Unit and Laboratory of Neuroscience, Istituto Auxologico Italiano, IRCCS, 20149 Milan, Italy; (L.C.); (A.D.); (D.B.); (V.S.)
| | - Vincenzo Silani
- Department of Neurology-Stroke Unit and Laboratory of Neuroscience, Istituto Auxologico Italiano, IRCCS, 20149 Milan, Italy; (L.C.); (A.D.); (D.B.); (V.S.)
- “Dino Ferrari” Center, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20122 Milan, Italy
- “Aldo Ravelli” Center for Neurotechnology and Experimental Brain Therapeutics, Università degli Studi di Milano, 20122 Milan, Italy
| | - Patrizia Bossolasco
- Department of Neurology-Stroke Unit and Laboratory of Neuroscience, Istituto Auxologico Italiano, IRCCS, 20149 Milan, Italy; (L.C.); (A.D.); (D.B.); (V.S.)
- Correspondence:
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Sims SKKC, Rizzo A, Howard K, Farrand A, Boger H, Adkins DL. Comparative Enhancement of Motor Function and BDNF Expression Following Different Brain Stimulation Approaches in an Animal Model of Ischemic Stroke. Neurorehabil Neural Repair 2020; 34:925-935. [PMID: 32909525 PMCID: PMC7572816 DOI: 10.1177/1545968320952798] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Combinatory intervention such as high-frequency (50-100 Hz) excitatory cortical stimulation (ECS) given concurrently with motor rehabilitative training (RT) improves forelimb function, except in severely impaired animals after stroke. Clinical studies suggest that low-frequency (≤1 Hz) inhibitory cortical stimulation (ICS) may provide an alternative approach to enhance recovery. Currently, the molecular mediators of CS-induced behavioral effects are unknown. Brain-derived neurotrophic factor (BDNF) has been associated with improved recovery and neural remodeling after stroke and thus may be involved in CS-induced behavioral recovery. OBJECTIVE To investigate whether inhibitory stimulation during RT improves functional recovery of severely impaired rats, following focal cortical ischemia and if this recovery alters BDNF expression (study 1) and depends on BDNF binding to TrkB receptors (study 2). METHODS Rats underwent ECS + RT, ICS + RT, or noCS + RT treatment daily for 3 weeks following a unilateral ischemic lesion to the motor cortex. Electrode placement for stimulation was either placed ipsilateral (ECS) or contralateral (ICS) to the lesion. After treatment, BDNF expression was measured in cortical tissue samples (study 1). In study 2, the TrkB inhibitor, ANA-12, was injected prior to treatment daily for 21 days. RESULTS ICS + RT treatment significantly improved impaired forelimb recovery compared with ECS + RT and noCS + RT treatment. CONCLUSION ICS given concurrently with rehabilitation improves motor recovery in severely impaired animals, and alters cortical BDNF expression; nevertheless, ICS-mediated improvements are not dependent on BDNF binding to TrkB. Conversely, inhibition of TrkB receptors does disrupt motor recovery in ECS + RT treated animals.
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Affiliation(s)
| | | | | | - Ariana Farrand
- Medical University of South Carolina, Charleston, SC, USA
| | - Heather Boger
- Medical University of South Carolina, Charleston, SC, USA
| | - DeAnna L Adkins
- National Institute of Neurological Diseases and Stroke, Rockville, MD, USA
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Li Z, Meng X, Ren M, Shao M. Combination of Scalp Acupuncture with Exercise Therapy Effectively Counteracts Ischemic Brain Injury in Rats. J Stroke Cerebrovasc Dis 2020; 29:105286. [PMID: 33066914 DOI: 10.1016/j.jstrokecerebrovasdis.2020.105286] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/14/2020] [Accepted: 08/23/2020] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Stroke is one of the leading causes of death and disability worldwide. Scalp acupuncture and exercise therapy have been proven as two effective methods for the treatment of stroke. However, their combined action and mechanisms have not been fully elucidated. The present study aimed to investigate the protective effect of scalp acupuncture combined with exercise therapy on neurons in rats with ischemic brain injury. METHODS 100 rats were randomly divided into 5 groups including sham group, model group, acupuncture group, rehabilitation group, and experimental group (scalp acupuncture combined with exercise therapy). Middle cerebral artery occlusion (MCAO) model in rats was established according to Longa modified suture method to mimic ischemic stroke. The modified Bedexer's neurological function score was used to evaluate the neurological deficits of rats and the brain infarct volume was measured using 2, 3, 5-triphenyl tetrazolium chloride monohydrate (TTC) staining. Moreover, the apoptosis in the hippocampus was detected by western blotting and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The pro-inflammatory cytokines such as interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α), reactive oxygen species (ROS) and superoxide dismutase (SOD) were determined by corresponding kits. Immunohistochemistry or immunofluorescence was performed to detect the expression of brain-derived neurotrophic factor (BDNF), S100β and glial fibrillary acidic protein (GFAP) in the hippocampi of rats. RESULTS The neurological deficit score, the expression levels of apoptotic factors such as cleaved caspase-3 and Bax, and the TUNEL-positive cell rate of the experimental group were significantly lower than those of the acupuncture group and the rehabilitation group. However, apoptosis inhibitor Bcl-2 showed downregulated expression in the MCAO model rats but this trend was reverted by single and combinatorial treatments. In addition, the contents of TNF-α, IL-1β and ROS in the acupuncture group and the rehabilitation group were significantly lower than those in the model group, but higher than the experimental group. While the opposite results were obtained in SOD activity. Furthermore, compared with the model group, the ratios of BDNF, S100β, and GFAP-positive cells in the acupuncture, rehabilitation and experimental groups were significantly increased, and the highest ratios were recorded in the experimental group. CONCLUSIONS This study demonstrated that scalp acupuncture combined with exercise therapy effectively counteracts ischemic brain injury via the downregulation of pro-inflammatory mediators and ROS, the increased production of the antioxidant enzyme SOD, neurotrophic factor BDNF and astrocyte activities.
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Affiliation(s)
- Zhenjing Li
- Department of Rehabilitation, Pudong New Area People's Hospital affiliated to Shanghai University of Medicine & Health Sciences, Shanghai 201299, P. R. China
| | - Xianzhong Meng
- Department of Rehabilitation, Pudong New Area People's Hospital affiliated to Shanghai University of Medicine & Health Sciences, Shanghai 201299, P. R. China.
| | - Min Ren
- Department of Rehabilitation, Pudong New Area People's Hospital affiliated to Shanghai University of Medicine & Health Sciences, Shanghai 201299, P. R. China
| | - Minglu Shao
- Department of Rehabilitation, Pudong New Area People's Hospital affiliated to Shanghai University of Medicine & Health Sciences, Shanghai 201299, P. R. China
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Cao T, Matyas JJ, Renn CL, Faden AI, Dorsey SG, Wu J. Function and Mechanisms of Truncated BDNF Receptor TrkB.T1 in Neuropathic Pain. Cells 2020; 9:cells9051194. [PMID: 32403409 PMCID: PMC7290366 DOI: 10.3390/cells9051194] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/08/2020] [Accepted: 05/08/2020] [Indexed: 12/11/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF), a major focus for regenerative therapeutics, has been lauded for its pro-survival characteristics and involvement in both development and recovery of function within the central nervous system (CNS). However, studies of tyrosine receptor kinase B (TrkB), a major receptor for BDNF, indicate that certain effects of the TrkB receptor in response to disease or injury may be maladaptive. More specifically, imbalance among TrkB receptor isoforms appears to contribute to aberrant signaling and hyperpathic pain. A truncated isoform of the receptor, TrkB.T1, lacks the intracellular kinase domain of the full length receptor and is up-regulated in multiple CNS injury models. Such up-regulation is associated with hyperpathic pain, and TrkB.T1 inhibition reduces neuropathic pain in various experimental paradigms. Deletion of TrkB.T1 also limits astrocyte changes in vitro, including proliferation, migration, and activation. Mechanistically, TrkB.T1 is believed to act through release of intracellular calcium in astrocytes, as well as through interactions with neurotrophins, leading to cell cycle activation. Together, these studies support a potential role for astrocytic TrkB.T1 in hyperpathic pain and suggest that targeted strategies directed at this receptor may have therapeutic potential.
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Affiliation(s)
- Tuoxin Cao
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (T.C.); (J.J.M.); (A.I.F.)
| | - Jessica J. Matyas
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (T.C.); (J.J.M.); (A.I.F.)
| | - Cynthia L. Renn
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD 21201, USA; (C.L.R.); (S.G.D.)
- Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD 21201, USA
| | - Alan I. Faden
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (T.C.); (J.J.M.); (A.I.F.)
- Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD 21201, USA
| | - Susan G. Dorsey
- Department of Pain and Translational Symptom Science, University of Maryland School of Nursing, Baltimore, MD 21201, USA; (C.L.R.); (S.G.D.)
- Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD 21201, USA
| | - Junfang Wu
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (T.C.); (J.J.M.); (A.I.F.)
- Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD 21201, USA
- Correspondence: ; Tel.: +1-410-706-5189
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15
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Neurotrophic effects of G M1 ganglioside, NGF, and FGF2 on canine dorsal root ganglia neurons in vitro. Sci Rep 2020; 10:5380. [PMID: 32214122 PMCID: PMC7096396 DOI: 10.1038/s41598-020-61852-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 03/04/2020] [Indexed: 01/26/2023] Open
Abstract
Dogs share many chronic morbidities with humans and thus represent a powerful model for translational research. In comparison to rodents, the canine ganglioside metabolism more closely resembles the human one. Gangliosides are components of the cell plasma membrane playing a role in neuronal development, intercellular communication and cellular differentiation. The present in vitro study aimed to characterize structural and functional changes induced by GM1 ganglioside (GM1) in canine dorsal root ganglia (DRG) neurons and interactions of GM1 with nerve growth factor (NGF) and fibroblast growth factor (FGF2) using immunofluorescence for several cellular proteins including neurofilaments, synaptophysin, and cleaved caspase 3, transmission electron microscopy, and electrophysiology. GM1 supplementation resulted in increased neurite outgrowth and neuronal survival. This was also observed in DRG neurons challenged with hypoxia mimicking neurodegenerative conditions due to disruptions of energy homeostasis. Immunofluorescence indicated an impact of GM1 on neurofilament phosphorylation, axonal transport, and synaptogenesis. An increased number of multivesicular bodies in GM1 treated neurons suggested metabolic changes. Electrophysiological changes induced by GM1 indicated an increased neuronal excitability. Summarized, GM1 has neurotrophic and neuroprotective effects on canine DRG neurons and induces functional changes. However, further studies are needed to clarify the therapeutic value of gangliosides in neurodegenerative diseases.
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16
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Xenos D, Kamceva M, Tomasi S, Cardin JA, Schwartz ML, Vaccarino FM. Loss of TrkB Signaling in Parvalbumin-Expressing Basket Cells Results in Network Activity Disruption and Abnormal Behavior. Cereb Cortex 2019; 28:3399-3413. [PMID: 28968898 DOI: 10.1093/cercor/bhx173] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Indexed: 12/11/2022] Open
Abstract
The GABAergic system is regulated by the brain-derived neurotrophic factor (BDNF)/Tropomyosin-related kinase B (TrkB) pathway, but the cell-intrinsic role of TrkB signaling in parvalbumin cortical interneuron development and function is unclear. We performed conditional ablation of the TrkB receptor in parvalbumin-expressing (PV) interneurons to study whether postnatal loss of TrkB in parvalbumin cells affects their survival, connectivity, spontaneous and evoked neuronal activity and behavior. Using in vivo recordings of local field potentials, we found reduced gamma oscillations in the sensory cortex of PVcre+; TrkBF/F conditional knockout mice (TrkB cKO), along with increased firing of putative excitatory neurons. There was a significant downregulation in parvalbumin neuron number in cerebral and cerebellar cortices of TrkB cKO mice. In addition, inhibitory synaptic connections between basket cells and pyramidal neurons were profoundly reduced in the neocortex of TrkB cKO mice and there was a loss of cortical volume. TrkB cKO mice also showed profound hyperactivity, stereotypies, motor deficits and learning/memory defects. Our findings demonstrate that the targeting and/or synapse formation of PV-expressing basket cells with principal excitatory neurons require TrkB signaling in parvalbumin cells. Disruption of this signaling has major consequences for parvalbumin interneuron connectivity, network dynamics, cognitive and motor behavior.
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Affiliation(s)
| | | | | | - Jessica A Cardin
- Department of Neuroscience.,Kavli Institute for Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | | | - Flora M Vaccarino
- Child Study Center.,Department of Neuroscience.,Kavli Institute for Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
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17
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Pradhan J, Noakes PG, Bellingham MC. The Role of Altered BDNF/TrkB Signaling in Amyotrophic Lateral Sclerosis. Front Cell Neurosci 2019; 13:368. [PMID: 31456666 PMCID: PMC6700252 DOI: 10.3389/fncel.2019.00368] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 07/29/2019] [Indexed: 12/11/2022] Open
Abstract
Brain derived neurotrophic factor (BDNF) is well recognized for its neuroprotective functions, via activation of its high affinity receptor, tropomysin related kinase B (TrkB). In addition, BDNF/TrkB neuroprotective functions can also be elicited indirectly via activation of adenosine 2A receptors (A2aRs), which in turn transactivates TrkB. Evidence suggests that alterations in BDNF/TrkB, including TrkB transactivation by A2aRs, can occur in several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). Although enhancing BDNF has been a major goal for protection of dying motor neurons (MNs), this has not been successful. Indeed, there is emerging in vitro and in vivo evidence suggesting that an upregulation of BDNF/TrkB can cause detrimental effects on MNs, making them more vulnerable to pathophysiological insults. For example, in ALS, early synaptic hyper-excitability of MNs is thought to enhance BDNF-mediated signaling, thereby causing glutamate excitotoxicity, and ultimately MN death. Moreover, direct inhibition of TrkB and A2aRs has been shown to protect MNs from these pathophysiological insults, suggesting that modulation of BDNF/TrkB and/or A2aRs receptors may be important in early disease pathogenesis in ALS. This review highlights the relevance of pathophysiological actions of BDNF/TrkB under certain circumstances, so that manipulation of BDNF/TrkB and A2aRs may give rise to alternate neuroprotective therapeutic strategies in the treatment of neural diseases such as ALS.
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Affiliation(s)
- Jonu Pradhan
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Peter G Noakes
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Mark C Bellingham
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
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18
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Targeting BDNF/TrkB pathways for preventing or suppressing epilepsy. Neuropharmacology 2019; 167:107734. [PMID: 31377199 DOI: 10.1016/j.neuropharm.2019.107734] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/25/2019] [Accepted: 08/01/2019] [Indexed: 12/15/2022]
Abstract
Traumatic brain injury (TBI) and status epilepticus (SE) have both been linked to development of human epilepsy. Although distinct etiologies, current research has suggested the convergence of molecular mechanisms underlying epileptogenesis following these insults. One such mechanism involves the neurotrophin brain-derived neurotrophic factor (BDNF) and its high-affinity receptor, tropomyosin related kinase B (TrkB). In this review, we focus on currently available data regarding the pathophysiologic role of BDNF/TrkB signaling in epilepsy development. We specifically examine the axonal injury and SE epilepsy models, two animal models that recapitulate many aspects of TBI- and SE-induced epilepsy in humans respectively. Thereafter, we discuss aspiring strategies for targeting BDNF/TrkB signaling so as to prevent epilepsy following an insult or suppress its expression once developed. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.
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19
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Kowiański P, Lietzau G, Czuba E, Waśkow M, Steliga A, Moryś J. BDNF: A Key Factor with Multipotent Impact on Brain Signaling and Synaptic Plasticity. Cell Mol Neurobiol 2018; 38:579-593. [PMID: 28623429 PMCID: PMC5835061 DOI: 10.1007/s10571-017-0510-4] [Citation(s) in RCA: 748] [Impact Index Per Article: 124.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 06/08/2017] [Indexed: 12/15/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is one of the most widely distributed and extensively studied neurotrophins in the mammalian brain. Among its prominent functions, one can mention control of neuronal and glial development, neuroprotection, and modulation of both short- and long-lasting synaptic interactions, which are critical for cognition and memory. A wide spectrum of processes are controlled by BDNF, and the sometimes contradictory effects of its action can be explained based on its specific pattern of synthesis, comprising several intermediate biologically active isoforms that bind to different types of receptor, triggering several signaling pathways. The functions of BDNF must be discussed in close relation to the stage of brain development, the different cellular components of nervous tissue, as well as the molecular mechanisms of signal transduction activated under physiological and pathological conditions. In this review, we briefly summarize the current state of knowledge regarding the impact of BDNF on regulation of neurophysiological processes. The importance of BDNF for future studies aimed at disclosing mechanisms of activation of signaling pathways, neuro- and gliogenesis, as well as synaptic plasticity is highlighted.
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Affiliation(s)
- Przemysław Kowiański
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Street, 80-211, Gdańsk, Poland.
- Department of Health Sciences, Pomeranian University of Slupsk, 64 Bohaterów Westerplatte Str., 76-200, Słupsk, Poland.
| | - Grażyna Lietzau
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Street, 80-211, Gdańsk, Poland
| | - Ewelina Czuba
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Street, 80-211, Gdańsk, Poland
| | - Monika Waśkow
- Department of Health Sciences, Pomeranian University of Slupsk, 64 Bohaterów Westerplatte Str., 76-200, Słupsk, Poland
| | - Aleksandra Steliga
- Department of Health Sciences, Pomeranian University of Slupsk, 64 Bohaterów Westerplatte Str., 76-200, Słupsk, Poland
| | - Janusz Moryś
- Department of Anatomy and Neurobiology, Medical University of Gdansk, 1 Debinki Street, 80-211, Gdańsk, Poland
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20
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Two New Cyathane Diterpenoids from Mycelial Cultures of the Medicinal Mushroom Hericium erinaceus and the Rare Species, Hericium flagellum. Int J Mol Sci 2018; 19:ijms19030740. [PMID: 29509661 PMCID: PMC5877601 DOI: 10.3390/ijms19030740] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 02/23/2018] [Accepted: 03/02/2018] [Indexed: 12/19/2022] Open
Abstract
Basidiomycetes of the genus Hericium are among the most praised medicinal and edible mushrooms, which are known to produce secondary metabolites with the potential to treat neurodegenerative diseases. This activity has been attributed to the discovery of various terpenoids that can stimulate the production of nerve growth factor (NGF) or (as established more recently) brain-derived neurotrophic factor (BDNF) in cell-based bioassays. The present study reports on the metabolite profiles of a Lion’s Mane mushroom (Hericium erinaceus) strain and a strain of the rare species, Hericium flagellum (synonym H. alpestre). While we observed highly similar metabolite profiles between the two strains that were examined, we isolated two previously undescribed metabolites, given the trivial names erinacines Z1 and Z2. Their chemical structures were elucidated by means of nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry. Along with six further, previously identified cyathane diterpenes, the novel erinacines were tested for neurotrophin inducing effects. We found that erinacines act on BDNF, which is a neurotrophic factor that has been reported recently by us to be induced by the corallocins, but as well on NGF expression, which is consistent with the literature.
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21
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Machaalani R, Chen H. Brain derived neurotrophic factor (BDNF), its tyrosine kinase receptor B (TrkB) and nicotine. Neurotoxicology 2018; 65:186-195. [DOI: 10.1016/j.neuro.2018.02.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/21/2018] [Accepted: 02/25/2018] [Indexed: 02/07/2023]
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22
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BDNF effects on dendritic spine morphology and hippocampal function. Cell Tissue Res 2018; 373:729-741. [DOI: 10.1007/s00441-017-2782-x] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 12/22/2017] [Indexed: 12/22/2022]
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23
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Choe S, Cai M, Jerng UM, Lee JH. The Efficacy and Underlying Mechanism of Moxibustion in Preventing Cognitive Impairment: A Systematic Review of Animal Studies. Exp Neurobiol 2018. [PMID: 29535565 PMCID: PMC5840457 DOI: 10.5607/en.2018.27.1.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cognitive impairment is age-related and manageable only with early diagnosis and prevention. Moxibustion is widely accepted in East Asia as useful for preventing cognitive impairment. This systematic review of animal studies was conducted to verify the efficacy of moxibustion in preventing cognitive impairment and to elucidate the underlying mechanism. Randomized controlled animal trials that established the efficacy of moxibustion in preventing cognitive impairment were included in the analysis. Results of behavioral tests and the signaling pathways elucidated were extracted and a meta-analysis was conducted with the behavioral test results. The risk of bias was evaluated using 9 items, and reporting quality was evaluated using the ARRIVE (Animal Research: Reporting In Vivo Experiments) Guidelines Checklist. Ten trials involving 410 animals met the inclusion criteria. All studies reported the benefit of moxibustion in preventing cognitive deficits caused by Alzheimer's disease (AD). Among five studies using the Morris water maze test, a significant effect of moxibustion in decreasing the escape time was reported in three studies, increasing the crossing times in four studies, and prolonging the dwelling time in two studies. The effects of moxibustion were demonstrated to be mediated by an increase in the activity of neurotrophins and heat shock protein, modulation of the cell cycle, and suppression of apoptosis and inflammation. However, considering the small number of included studies, the lack of studies investigating entire signaling pathways, and a high risk of bias and low reporting quality, our results need to be confirmed through more detailed studies.
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Affiliation(s)
- Seon Choe
- Clinical Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.,Korean Medicine Life Science, University of Science & Technology (UST), Campus of Korea Institute of Oriental Medicine, Daejeon 34054, Korea
| | - Mudan Cai
- Clinical Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea
| | - Ui Min Jerng
- Clinical Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.,Department of Internal Medicine, College of Korean Medicine, Sangji University, Wonju 26339, Korea
| | - Jun-Hwan Lee
- Clinical Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.,Korean Medicine Life Science, University of Science & Technology (UST), Campus of Korea Institute of Oriental Medicine, Daejeon 34054, Korea
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24
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Azogu I, Plamondon H. Blockade of TrkB receptors in the nucleus accumbens prior to heterotypic stress alters corticotropin-releasing hormone (CRH), vesicular glutamate transporter 2 (vGluT2) and glucocorticoid receptor (GR) within the mesolimbic pathway. Horm Behav 2017; 90:98-112. [PMID: 28257759 DOI: 10.1016/j.yhbeh.2017.02.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 11/22/2016] [Accepted: 02/22/2017] [Indexed: 12/27/2022]
Abstract
Inhibition of stress-induced elevations in brain-derived neurotrophic factor (BDNF) or its primary receptor tyrosine-related kinase B (TrkB) within the reward pathway may modulate vulnerability to anxiety and mood disorders. The current study examined the role of BDNF/TrkB signaling on biochemistry and behavior under basal conditions and following exposure to a 10-day heterotypic stress paradigm in male rats. Effects of intra-accumbal administration of TrkB antagonist ANA-12 (0.25μg/0.5μl/min) on anxiety, and expression of Trk-B, corticotropin-releasing hormone (CRH), vesicular glutamate transporter 2 (vGluT2) and glucocorticoid receptor (GR) within the mesolimbic pathway were determined. Notably, ANA-12 attenuated anxiety-like behavior in stress rats while increasing anxiety in the non-stress group in the elevated plus maze (EPM). At the neurochemical level, ANA-12 blocked the increased vGluT2 and CRH expressions in the hypothalamic PVN and basolateral amygdala in stress rats, while it enhanced vGluT2 and CRH expressions in non-stress rats. ANA-12 also showed state-dependent effects at the NAc core, attenuating TrkB-ir in non-stress rats while reversing reduced expression in stressed rats. At the cingulate cortex, ANA-12 normalized stress-induced increase in TrkB expression. Notably, ANA-12 showed region-specific effects on GR-ir at the NAc core and shell, with increased GR-ir in non-stress rats, although the drug attenuated stress-induced GR-ir expression only in the core portion of the NAc, while having no impact at the cingulate cortex. Elevated blood CORT levels post-stress was not influenced by ANA-12 treatment. Together, these findings suggest that BDNF-mediated TrkB activation exerts differential impact in regulating emotional response under basal and stress conditions.
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Affiliation(s)
- Idu Azogu
- Behavioural Neuroscience Group, School of Psychology, University of Ottawa, 136 Jean-Jacques Lussier, Ottawa, ON, Canada
| | - Helene Plamondon
- Behavioural Neuroscience Group, School of Psychology, University of Ottawa, 136 Jean-Jacques Lussier, Ottawa, ON, Canada.
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25
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Wright DJ, Renoir T, Gray LJ, Hannan AJ. Huntington’s Disease: Pathogenic Mechanisms and Therapeutic Targets. ADVANCES IN NEUROBIOLOGY 2017; 15:93-128. [DOI: 10.1007/978-3-319-57193-5_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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26
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Kobayashi K, Sano H, Kato S, Kuroda K, Nakamuta S, Isa T, Nambu A, Kaibuchi K, Kobayashi K. Survival of corticostriatal neurons by Rho/Rho-kinase signaling pathway. Neurosci Lett 2016; 630:45-52. [PMID: 27424794 DOI: 10.1016/j.neulet.2016.07.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 07/07/2016] [Accepted: 07/13/2016] [Indexed: 01/10/2023]
Abstract
Developing cortical neurons undergo a number of sequential developmental events including neuronal survival/apoptosis, and the molecular mechanism underlying each characteristic process has been studied in detail. However, the survival pathway of cortical neurons at mature stages remains largely uninvestigated. We herein focused on mature corticostriatal neurons because of their important roles in various higher brain functions and the spectrum of neurological and neuropsychiatric disorders. The small GTPase Rho is known to control diverse and essential cellular functions through some effector molecules, including Rho-kinase, during neural development. In the present study, we investigated the role of Rho signaling through Rho-kinase in the survival of corticostriatal neurons. We performed the conditional expression of Clostridium botulinum C3 ADP-ribosyltransferase (C3 transferase) or dominant-negative form for Rho-kinase (Rho-K DN), a well-known inhibitor of Rho or Rho-kinase, respectively, in corticostriatal neurons using a dual viral vector approach combining a neuron-specific retrograde gene transfer lentiviral vector and an adeno-associated virus vector. C3 transferase markedly decreased the number of corticostriatal neurons, which was attributed to caspase-3-dependent enhanced apoptosis. In addition, Rho-K DN produced phenotypic defects similar to those caused by C3 transferase. These results indicate that the Rho/Rho-kinase signaling pathway plays a crucial role in the survival of corticostriatal neurons.
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Affiliation(s)
- Kenta Kobayashi
- Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan; SOKENDAI (The Graduate University for Advanced Studies), Hayama 240-0193, Japan.
| | - Hiromi Sano
- SOKENDAI (The Graduate University for Advanced Studies), Hayama 240-0193, Japan; Division of System Neurophysiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Shigeki Kato
- Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima 960-1295, Japan
| | - Keisuke Kuroda
- Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Shinichi Nakamuta
- Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Tadashi Isa
- Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan; SOKENDAI (The Graduate University for Advanced Studies), Hayama 240-0193, Japan; Department of Developmental Physiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Atsushi Nambu
- Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan; SOKENDAI (The Graduate University for Advanced Studies), Hayama 240-0193, Japan; Division of System Neurophysiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Kozo Kaibuchi
- Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Kazuto Kobayashi
- Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima 960-1295, Japan
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Kärkkäinen E, Lahtinen HM, Närväinen J, Gröhn O, Tanila H. Brain Amyloidosis and BDNF Deficiency Have Opposite Effects on Brain Volumes in AβPP/PS1 Mice Both in vivo and ex vivo. J Alzheimers Dis 2016; 46:929-46. [PMID: 26402627 DOI: 10.3233/jad-150059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Magnetic resonance imaging (MRI) volumetry is widely used in Alzheimer's disease (AD) research and diagnostics alongside clinical assessment. Yet few MRI volumetry studies have been conducted in AD model mice with mixed results. We performed in vivo and ex vivo MRI and extensive postmortem histological analysis in transgenic mice derived from crossing amyloid plaque producing AβPP/PS1 mice with brain-derived neurotrophic factor (BDNF) +/- mice. This allowed us to compare developmental volumetric changes due to BDNF deficiency with progressive changes due to amyloid accumulation. We found decreased whole brain volume at 3 months and decreased cortical volume at both 3 and 8 months in vivo in BDNF +/- Tg mice but increased whole brain and cortical volumes at 8 months in AβPP/PS1 mice. Consistent with this, the postmortem histological analysis showed decreased brain parenchymal area in BDNF +/- mice but an increase in AβPP/PS1 mice. BDNF gene deficiency did not affect brain amyloid load or astrogliosis, but led to decreased dentate gyrus length, whereas AβPP/PS1 mice had significantly increased amyloid load, astrogliosis, and decreased neurogenesis. Distinct and layer-specific effects were found in the hippocampus of AβPP/PS1 and BDNF +/- mice. In contrast to human AD patients, brain atrophy in amyloid producing mice appears to be masked by volume increase due to amyloid accumulation and especially accompanying astrogliosis. Our results indicate that cortical MRI volumetry can be used to some extent as a proxy to progressive brain amyloidosis in preclinical studies.
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Affiliation(s)
- Elisa Kärkkäinen
- A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | | | - Johanna Närväinen
- A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Olli Gröhn
- A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Heikki Tanila
- A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland.,Department of Neurology, Kuopio University Hospital, Kuopio, Finland
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Proenca CC, Song M, Lee FS. Differential effects of BDNF and neurotrophin 4 (NT4) on endocytic sorting of TrkB receptors. J Neurochem 2016; 138:397-406. [PMID: 27216821 DOI: 10.1111/jnc.13676] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 05/03/2016] [Accepted: 05/19/2016] [Indexed: 01/31/2023]
Abstract
Neurotrophins are a family of growth factors playing key roles in the survival, development, and function of neurons. The neurotrophins brain-derived neurotrophic factor (BDNF) and NT4 both bind to and activate TrkB receptors, however, they mediate distinct neuronal functions. The molecular mechanism of how TrkB activation by BDNF and NT4 leads to diverse outcomes is unknown. Here, we report that BDNF and NT4 lead to differential endocytic sorting of TrkB receptors resulting in diverse biological functions in cultured cortical neurons. Fluorescent microscopy and surface biotinylation experiments showed that both neurotrophins stimulate internalization of TrkB with similar kinetics. Exposure to BDNF for 2-3 h reduced the surface pool of TrkB receptors to half, whereas a longer treatment (4-5 h) with NT4 was necessary to achieve a similar level of down-regulation. Although BDNF and NT4 induced TrkB phosphorylation with similar intensities, BDNF induced more rapid ubiquitination and degradation of TrkB than NT4. Interestingly, TrkB receptor ubiquitination by these ligands have substantially different pH sensitivities, resulting in varying degrees of receptor ubiquitination at lower pH levels. Consequently, NT4 was capable of maintaining longer sustained downstream signaling activation that correlated with reduced TrkB ubiquitination at endosomal pH. Thus, by leading to altered endocytic trafficking itineraries for TrkB receptors, BDNF and NT4 elicit differential TrkB signaling in terms of duration, intensity, and specificity, which may contribute to their functional differences in vivo. The neurotrophins, brain-derived neurotrophic factor (BDNF) and neurotrophin-4 (NT4), both bind to and activate TrkB receptors, however, they mediate distinct neuronal functions. Here, we propose that BDNF and NT4 lead to differential endocytic sorting of TrkB receptors resulting in diverse biological functions. BDNF induces more rapid ubiquitination and degradation of TrkB than NT4. Consequently, NT4 is capable of maintaining more sustained signaling downstream of TrkB receptors.
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Affiliation(s)
- Catia C Proenca
- Developmental and Molecular Pathways, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Minseok Song
- Synaptic Circuit Plasticity Laboratory, Department of Structure & Function of Neural Network, Korea Brain Research Institute, 61 Cheomdan-ro, Dong-gu, Daegu, Korea
| | - Francis S Lee
- Department of Psychiatry, Weill Medical College of Cornell University, New York City, New York, USA.,Department of Pharmacology, Weill Medical College of Cornell University, New York City, New York, USA
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Nguyen KQ, Rymar VV, Sadikot AF. Impaired TrkB Signaling Underlies Reduced BDNF-Mediated Trophic Support of Striatal Neurons in the R6/2 Mouse Model of Huntington's Disease. Front Cell Neurosci 2016; 10:37. [PMID: 27013968 PMCID: PMC4783409 DOI: 10.3389/fncel.2016.00037] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 02/01/2016] [Indexed: 11/13/2022] Open
Abstract
The principal projection neurons of the striatum are critically dependent on an afferent supply of brain derived neurotrophic factor (BDNF) for neurotrophic support. These neurons express TrkB, the cognate receptor for BDNF, which activates signaling pathways associated with neuronal survival and phenotypic maintenance. Impairment of the BDNF-TrkB pathway is suspected to underlie the early dysfunction and prominent degeneration of striatal neurons in Huntington disease (HD). Some studies in HD models indicate that BDNF supply is reduced, while others suggest that TrkB signaling is impaired earlier in disease progression. It remains important to determine whether a primary defect in TrkB signaling underlies reduced neurotrophic support and the early vulnerability of striatal neurons in HD. Using the transgenic R6/2 mouse model of HD we found that prior to striatal degeneration there are early deficits in striatal protein levels of activated phospho-TrkB and the downstream-regulated protein DARPP-32. In contrast, total-TrkB and BDNF protein levels remained normal. Primary neurons cultured from R6/2 striatum exhibited reduced survival in response to exogenous BDNF applications. Moreover, BDNF activation of phospho-TrkB and downstream signal transduction was attenuated in R6/2 striatal cultures. These results suggest that neurotrophic support of striatal neurons is attenuated early in disease progression due to defects in TrkB signal transduction in the R6/2 model of HD.
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Affiliation(s)
- Khanh Q Nguyen
- Cone Laboratory, Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University Montreal, QC, Canada
| | - Vladimir V Rymar
- Cone Laboratory, Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University Montreal, QC, Canada
| | - Abbas F Sadikot
- Cone Laboratory, Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University Montreal, QC, Canada
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Gu B, Huang YZ, He XP, Joshi RB, Jang W, McNamara JO. A Peptide Uncoupling BDNF Receptor TrkB from Phospholipase Cγ1 Prevents Epilepsy Induced by Status Epilepticus. Neuron 2015; 88:484-91. [PMID: 26481038 DOI: 10.1016/j.neuron.2015.09.032] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 05/26/2015] [Accepted: 08/26/2015] [Indexed: 12/26/2022]
Abstract
The BDNF receptor tyrosine kinase, TrkB, underlies nervous system function in both health and disease. Excessive activation of TrkB caused by status epilepticus promotes development of temporal lobe epilepsy (TLE), revealing TrkB as a therapeutic target for prevention of TLE. To circumvent undesirable consequences of global inhibition of TrkB signaling, we implemented a novel strategy aimed at selective inhibition of the TrkB-activated signaling pathway responsible for TLE. Our studies of a mouse model reveal that phospholipase Cγ1 (PLCγ1) is the dominant signaling effector by which excessive activation of TrkB promotes epilepsy. We designed a novel peptide (pY816) that uncouples TrkB from PLCγ1. Treatment with pY816 following status epilepticus inhibited TLE and prevented anxiety-like disorder yet preserved neuroprotective effects of endogenous TrkB signaling. We provide proof-of-concept evidence for a novel strategy targeting receptor tyrosine signaling and identify a therapeutic with promise for prevention of TLE caused by status epilepticus in humans.
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Affiliation(s)
- Bin Gu
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Yang Zhong Huang
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Xiao-Ping He
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Rasesh B Joshi
- Department of Electrical and Computer Engineering, Duke University, Durham, NC 27710, USA
| | - Wonjo Jang
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - James O McNamara
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA.
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31
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Multivariate genetic determinants of EEG oscillations in schizophrenia and psychotic bipolar disorder from the BSNIP study. Transl Psychiatry 2015; 5:e588. [PMID: 26101851 PMCID: PMC4490286 DOI: 10.1038/tp.2015.76] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 04/27/2015] [Accepted: 05/04/2015] [Indexed: 01/18/2023] Open
Abstract
Schizophrenia (SZ) and psychotic bipolar disorder (PBP) are disabling psychiatric illnesses with complex and unclear etiologies. Electroencephalogram (EEG) oscillatory abnormalities in SZ and PBP probands are heritable and expressed in their relatives, but the neurobiology and genetic factors mediating these abnormalities in the psychosis dimension of either disorder are less explored. We examined the polygenic architecture of eyes-open resting state EEG frequency activity (intrinsic frequency) from 64 channels in 105 SZ, 145 PBP probands and 56 healthy controls (HCs) from the multisite BSNIP (Bipolar-Schizophrenia Network on Intermediate Phenotypes) study. One million single-nucleotide polymorphisms (SNPs) were derived from DNA. We assessed eight data-driven EEG frequency activity derived from group-independent component analysis (ICA) in conjunction with a reduced subset of 10,422 SNPs through novel multivariate association using parallel ICA (para-ICA). Genes contributing to the association were examined collectively using pathway analysis tools. Para-ICA extracted five frequency and nine SNP components, of which theta and delta activities were significantly correlated with two different gene components, comprising genes participating extensively in brain development, neurogenesis and synaptogenesis. Delta and theta abnormality was present in both SZ and PBP, while theta differed between the two disorders. Theta abnormalities were also mediated by gene clusters involved in glutamic acid pathways, cadherin and synaptic contact-based cell adhesion processes. Our data suggest plausible multifactorial genetic networks, including novel and several previously identified (DISC1) candidate risk genes, mediating low frequency delta and theta abnormalities in psychoses. The gene clusters were enriched for biological properties affecting neural circuitry and involved in brain function and/or development.
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32
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Deng YP, Wong T, Wan JY, Reiner A. Differential loss of thalamostriatal and corticostriatal input to striatal projection neuron types prior to overt motor symptoms in the Q140 knock-in mouse model of Huntington's disease. Front Syst Neurosci 2014; 8:198. [PMID: 25360089 PMCID: PMC4197654 DOI: 10.3389/fnsys.2014.00198] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/23/2014] [Indexed: 11/13/2022] Open
Abstract
Motor slowing and forebrain white matter loss have been reported in premanifest Huntington's disease (HD) prior to substantial striatal neuron loss. These findings raise the possibility that early motor defects in HD may be related to loss of excitatory input to striatum. In a prior study, we showed that in the heterozygous Q140 knock-in mouse model of HD that loss of thalamostriatal axospinous terminals is evident by 4 months, and loss of corticostriatal axospinous terminals is evident at 12 months, before striatal projection neuron pathology. In the present study, we specifically characterized the loss of thalamostriatal and corticostriatal terminals on direct (dSPN) and indirect (iSPN) pathway striatal projection neurons, using immunolabeling to identify thalamostriatal (VGLUT2+) and corticostriatal (VGLUT1+) axospinous terminals, and D1 receptor immunolabeling to distinguish dSPN (D1+) and iSPN (D1-) synaptic targets. We found that the loss of corticostriatal terminals at 12 months of age was preferential for D1+ spines, and especially involved smaller terminals, presumptively of the intratelencephalically projecting (IT) type. By contrast, indirect pathway D1- spines showed little loss of axospinous terminals at the same age. Thalamostriatal terminal loss was comparable for D1+ and D1- spines at both 4 and 12 months. Regression analysis showed that the loss of VGLUT1+ terminals on D1+ spines was correlated with a slight decline in open field motor parameters at 12 months. Our overall results raise the possibility that differential thalamic and cortical input loss to SPNs is an early event in human HD, with cortical loss to dSPNs in particular contributing to premanifest motor slowing.
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Affiliation(s)
- Yun-Ping Deng
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center Memphis, TN, USA
| | - Ting Wong
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center Memphis, TN, USA
| | - Jim Y Wan
- Department of Preventive Medicine, The University of Tennessee Health Science Center Memphis, TN, USA
| | - Anton Reiner
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center Memphis, TN, USA
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Baydyuk M, Xu B. BDNF signaling and survival of striatal neurons. Front Cell Neurosci 2014; 8:254. [PMID: 25221473 PMCID: PMC4147651 DOI: 10.3389/fncel.2014.00254] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 08/11/2014] [Indexed: 01/22/2023] Open
Abstract
The striatum, a major component of the basal ganglia, performs multiple functions including control of movement, reward, and addiction. Dysfunction and death of striatal neurons are the main causes for the motor disorders associated with Huntington’s disease (HD). Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, is among factors that promote survival and proper function of this neuronal population. Here, we review recent studies showing that BDNF determines the size of the striatum by supporting survival of the immature striatal neurons at their origin, promotes maturation of striatal neurons, and facilitates establishment of striatal connections during brain development. We also examine the role of BDNF in maintaining proper function of the striatum during adulthood, summarize the mechanisms that lead to a deficiency in BDNF signaling and subsequently striatal degeneration in HD, and highlight a potential role of BDNF as a therapeutic target for HD treatment.
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Affiliation(s)
- Maryna Baydyuk
- National Institute of Neurological Diseases and Stroke, National Institutes of Health Bethesda, MD, USA
| | - Baoji Xu
- Department of Neuroscience, The Scripps Research Institute Florida Jupiter, FL, USA
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34
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BRCA1-IRIS inactivation sensitizes ovarian tumors to cisplatin. Oncogene 2014; 34:3036-52. [PMID: 25132263 DOI: 10.1038/onc.2014.237] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 06/25/2014] [Accepted: 06/26/2014] [Indexed: 12/27/2022]
Abstract
Ovarian cancer is the first in mortalities among gynecologic cancers in the United States, often due to late diagnosis and/or acquired platinum-resistant recurrences. This study investigates whether BRCA1-IRIS is a novel treatment target for ovarian cancers and in platinum-resistant recurrences. Here we show that more than half of the ovarian cancer samples analyzed showed BRCA1-IRIS and survivin overexpression and lacked nuclear FOXO3a expression. Normal ovarian epithelial cells overexpressing BRCA1-IRIS formed metastasis in mice when injected in the peritoneal cavity, whereas aggressive ovarian cancer cell lines failed to form tumors or metastases in mice when BRCA1-IRIS was silenced in them. We show that BRCA1-IRIS activates two autocrine signaling loops, brain-derived neurotrophic factor/tyrosine kinase B receptor (BDNF/TrkB) and neuregulin 1 (NRG1)/ErbB2. These loops are involved in anoikis resistance and metastasis promotion. These loops operate in several ovarian cancer cell lines, and BRCA1-IRIS silencing or inactivation using a novel inhibitory peptide renders both non-functional and promoted cell death. In a mouse xenograft model, BRCA1-IRIS inactivation using this novel inhibitory peptide resulted in significant reduction in ovarian tumor growth. More importantly, this treatment sensitized ovarian tumors to low cisplatin concentrations. Taken together, these data strongly suggest that BRCA1-IRIS and/or BDNF/TrkB and NRG1/ErbB2 could serve as rational therapeutic targets for advanced ovarian cancers.
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Klaric TS, Thomas PQ, Dottori M, Leong WK, Koblar SA, Lewis MD. A reduction in Npas4 expression results in delayed neural differentiation of mouse embryonic stem cells. Stem Cell Res Ther 2014; 5:64. [PMID: 24887558 PMCID: PMC4076635 DOI: 10.1186/scrt453] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 04/11/2014] [Indexed: 01/19/2023] Open
Abstract
INTRODUCTION Npas4 is a calcium-dependent transcription factor expressed within neurons of the brain where it regulates the expression of several genes that are important for neuronal survival and synaptic plasticity. It is known that in the adult brain Npas4 plays an important role in several key aspects of neurobiology including inhibitory synapse formation, neuroprotection and memory, yet very little is known about the role of Npas4 during neurodevelopment. The aim of this study was to examine the expression and function of Npas4 during nervous system development by using a combination of in vivo experiments in the developing mouse embryo and neural differentiation of embryonic stem cells (ESCs) as an in vitro model of the early stages of embryogenesis. METHODS Two different neural differentiation paradigms were used to investigate Npas4 expression during neurodevelopment in vitro; adherent monolayer differentiation of mouse ESCs in N2B27 medium and Noggin-induced differentiation of human ESCs. This work was complemented by direct analysis of Npas4 expression in the mouse embryo. The function of Npas4 in the context of neurodevelopment was investigated using loss-of-function experiments in vitro. We created several mouse ESC lines in which Npas4 expression was reduced during neural differentiation through RNA interference and we then analyzed the ability of these Npas4 knockdown mouse ESCs lines to undergo neural differentiation. RESULTS We found that while Npas4 is not expressed in undifferentiated ESCs, it becomes transiently up-regulated during neural differentiation of both mouse and human ESCs at a stage of differentiation that is characterized by proliferation of neural progenitor cells. This was corroborated by analysis of Npas4 expression in the mouse embryo where the Npas4 transcript was detected specifically in the developing forebrain beginning at embryonic day 9.5. Finally, knockdown of Npas4 expression in mouse ESCs undergoing neural differentiation affected their ability to differentiate appropriately, resulting in delayed neural differentiation. CONCLUSIONS Here we provide the first evidence that Npas4 is expressed during embryonic development and that it may have a developmental role that is unrelated to its function in the adult brain.
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Ceni C, Unsain N, Zeinieh MP, Barker PA. Neurotrophins in the regulation of cellular survival and death. Handb Exp Pharmacol 2014; 220:193-221. [PMID: 24668474 DOI: 10.1007/978-3-642-45106-5_8] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The neurotrophins play crucial roles regulating survival and apoptosis in the developing and injured nervous system. The four neurotrophins exert profound and crucial survival effects on developing peripheral neurons, and their expression and action is intimately tied to successful innervation of peripheral targets. In the central nervous system, they are dispensable for neuronal survival during development but support neuronal survival after lesion or other forms of injury. Neurotrophins also regulate apoptosis of both peripheral and central neurons, and we now recognize that there are regulatory advantages to having the same molecules regulate life and death decisions. This chapter examines the biological contexts in which these events take place and highlights the specific ligands, receptors, and signaling mechanisms that allow them to occur.
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Affiliation(s)
- Claire Ceni
- Centre for Neuronal Survival, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, QC, Canada, H3A 2B4
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37
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Expression of full-length and truncated trkB in human striatum and substantia nigra neurons: implications for Parkinson's disease. J Mol Histol 2013; 45:349-61. [PMID: 24374887 DOI: 10.1007/s10735-013-9562-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 12/17/2013] [Indexed: 12/20/2022]
Abstract
Brain derived neurotrophic factor (BDNF) is a potent mediator of cell survival and differentiation and can reverse neuronal injury associated with Parkinson's disease (PD). Tropomyosin receptor kinase B (trkB) is the high affinity receptor for BDNF. There are two major trkB isoforms, the full-length receptor (trkB.tk(+)) and the truncated receptor (trkB.t1), that mediate the diverse, region specific functions of BDNF. Both trkB isoforms are widely distributed throughout the brain, but the isoform specific distribution of trkB.t1 and trkB.tk(+) to human neurons is not well characterized. Therefore, we report the regional and neuronal distribution of trkB.tk(+) and trkB.t1 in the striatum and substantia nigra pars compacta (SNpc) of human autopsy tissues from control and PD cases. In both PD and control tissues, we found abundant, punctate distribution of trkB.tk(+) and trkB.t1 proteins in striatum and SNpc neurons. In PD, trkB.tk(+) is decreased in striatal neurites, increased in striatal somata, decreased in SNpc somata and dendrites, and increased in SNpc axons. TrkB.t1 is increased in striatal somata, decreased in striatal axons, and increased in SNpc distal dendrites. We believe changes in trkB isoform distribution and expression levels may be markers of pathology and affect the neuronal response to BDNF.
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38
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Olsen D, Kaas M, Schwartz O, Nykjaer A, Glerup S. Loss of BDNF or its receptors in three mouse models has unpredictable consequences for anxiety and fear acquisition. Learn Mem 2013; 20:499-504. [PMID: 23959707 DOI: 10.1101/lm.032045.113] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BDNF-induced signaling is essential for the development of the central nervous system and critical for plasticity in adults. Mature BDNF signals through TrkB, while its precursor proBDNF employs p75(NTR), resulting in activation of signaling cascades with opposite effects on neuronal survival, growth cone decisions, and synaptic plasticity. Accordingly, variations in the genes encoding BDNF and its receptors sometimes have opposing influences in psychiatric disorders, and despite the vast literature, consensus is lacking about the behavioral consequences of disrupting the activity of the BDNF system in mice. To dissect the behavioral traits affected by dysfunctional BDNF/TrkB vs. proBDNF/p75(NTR) activity, we studied Bdnf(+/-), Ntrk2(+/-), and Ngfr(-/-) mice in parallel with respect to exploratory behavior, anxiety, startle, and fear acquisition. Our data reveal that the effect of proBDNF/BDNF and its receptors on behavior is more complex than expected. Strikingly, receptor-deficient mice displayed increased risk-taking behavior in the open field and elevated plus maze, whereas lack of proBDNF/BDNF had the opposite effect on mouse behavior. On the other hand, although TrkB signaling is instrumental for acquisition of fear memory in an inhibitory avoidance experiment, lack of p75(NTR) or proBDNF/BDNF conferred increased memory in this task. Importantly, none of the genotypes displayed any deficits in startle reflex, indicating unimpaired response to shock. The combined data illustrate an apparent paradox in the role of the BDNF system in controlling complex behavior and suggest that the individual components may also engage independently in separate signaling pathways.
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Affiliation(s)
- Ditte Olsen
- The Lundbeck Foundation Research Centre, MIND, Danish Research Institute of Translational Neuroscience DANDRITE, Nordic EMBL Partnership, Department of Biomedicine, Aarhus University, DK-8000C Aarhus, Denmark
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Murase S. A new model for developmental neuronal death and excitatory/inhibitory balance in hippocampus. Mol Neurobiol 2013; 49:316-25. [PMID: 23943504 DOI: 10.1007/s12035-013-8521-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 07/22/2013] [Indexed: 11/24/2022]
Abstract
The nervous system develops through a program that produces neurons in excess and then eliminates approximately half during a period of naturally occurring death. Neuronal activity has been shown to promote the survival of neurons during this period by stimulating the production and release of neurotrophins. In the peripheral nervous system (PNS), neurons depends on neurotrophins that activate survival pathways, which explains how the size of target cells influences number of neurons that innervate them (neurotrophin hypothesis). However, in the central nervous system (CNS), the role of neurotrophins has not been clear. Contrary to the neurotrophin hypothesis, a recent study shows that, in neonatal hippocampus, neurotrophins cannot promote survival without spontaneous network activity: Neurotrophins recruit neurons into spontaneously active networks, and this activity determines which neurons survive. By placing neurotrophin upstream of activity in the survival signaling pathway, these new results change our understanding of how neurotrophins promote survival. Spontaneous, synchronized network activity begins to spread through both principle neurons and interneurons in the hippocampus as they enter the death period. At this stage, neurotransmission mediated by γ-aminobutyric acid (GABA) is excitatory and drives the spontaneous activity. An important recent observation is that neurotrophins preferentially recruit GABAergic neurons into spontaneously active networks; thus, neurotrophins select for survival only those neurons joined to active networks with strong GABAergic inputs, which would later become inhibitory. A proper excitatory/inhibitory (E/I) balance is critical for normal adult brain function. This balance may be especially important in the hippocampus where impairments in E/I balance are associated with pathologies including epilepsy. Here, I discuss the molecular mechanisms for survival in neonatal neurons, how these mechanisms change during development, and how they may be linked to degenerative diseases.
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Affiliation(s)
- Sachiko Murase
- Laboratory of Molecular Biology, National Institute of Neurological Disorder and Stroke, National Institutes of Health, 35 Lincoln Dr., Bethesda, MD, 20892, USA,
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40
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SOX2 co-occupies distal enhancer elements with distinct POU factors in ESCs and NPCs to specify cell state. PLoS Genet 2013; 9:e1003288. [PMID: 23437007 PMCID: PMC3578749 DOI: 10.1371/journal.pgen.1003288] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 12/15/2012] [Indexed: 01/26/2023] Open
Abstract
SOX2 is a master regulator of both pluripotent embryonic stem cells (ESCs) and multipotent neural progenitor cells (NPCs); however, we currently lack a detailed understanding of how SOX2 controls these distinct stem cell populations. Here we show by genome-wide analysis that, while SOX2 bound to a distinct set of gene promoters in ESCs and NPCs, the majority of regions coincided with unique distal enhancer elements, important cis-acting regulators of tissue-specific gene expression programs. Notably, SOX2 bound the same consensus DNA motif in both cell types, suggesting that additional factors contribute to target specificity. We found that, similar to its association with OCT4 (Pou5f1) in ESCs, the related POU family member BRN2 (Pou3f2) co-occupied a large set of putative distal enhancers with SOX2 in NPCs. Forced expression of BRN2 in ESCs led to functional recruitment of SOX2 to a subset of NPC-specific targets and to precocious differentiation toward a neural-like state. Further analysis of the bound sequences revealed differences in the distances of SOX and POU peaks in the two cell types and identified motifs for additional transcription factors. Together, these data suggest that SOX2 controls a larger network of genes than previously anticipated through binding of distal enhancers and that transitions in POU partner factors may control tissue-specific transcriptional programs. Our findings have important implications for understanding lineage specification and somatic cell reprogramming, where SOX2, OCT4, and BRN2 have been shown to be key factors. In mammals, a few thousand transcription factors regulate the differential expression of more than 20,000 genes to specify ∼200 functionally distinct cell types during development. How this is accomplished has been a major focus of biology. Transcription factors bind non-coding DNA regulatory elements, including proximal promoters and distal enhancers, to control gene expression. Emerging evidence indicates that transcription factor binding at distal enhancers plays an important role in the establishment of tissue-specific gene expression programs during development. Further, combinatorial binding among groups of transcription factors can further increase the diversity and specificity of regulatory modules. Here, we report the genome-wide binding profile of the HMG-box containing transcription factor SOX2 in mouse embryonic stem cells (ESCs) and neural progenitor cells (NPCs), and we show that SOX2 occupied a distinct set of binding sites with POU homeodomain family members, OCT4 in ESCs and BRN2 in NPCs. Thus, transitions in SOX2-POU partners may control tissue-specific gene networks. Ultimately, a global analysis detailing the combinatorial binding of transcription factors across all tissues is critical to understand cell fate specification in the context of the complex mammalian genome.
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Reiner A, Wang HB, Del Mar N, Sakata K, Yoo W, Deng YP. BDNF may play a differential role in the protective effect of the mGluR2/3 agonist LY379268 on striatal projection neurons in R6/2 Huntington's disease mice. Brain Res 2012; 1473:161-72. [PMID: 22820300 DOI: 10.1016/j.brainres.2012.07.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 07/04/2012] [Accepted: 07/12/2012] [Indexed: 10/28/2022]
Abstract
We have found that daily subcutaneous injection with a maximum tolerated dose (MTD) of the mGluR2/3 agonist LY379268 (20mg/kg) beginning at 4 weeks dramatically improves the phenotype in R6/2 mice. For example, we observed normalization of motor function in distance traveled, speed, the infrequency of pauses, and the ability to locomote in a straight line, and a rescue of a 15-20% striatal neuron loss at 10 weeks. As acute LY379268 treatment is known to increase cortical BDNF production, and BDNF is known to be beneficial for striatal neurons, we investigated if the benefit of daily LY379268 in R6/2 mice for striatal projection neurons was associated with increases in corticostriatal BDNF, with assessments done at 10 weeks of age after daily MTD treatment since the fourth week of life. We found that LY379268 increased BDNF expression in layer 5 neurons in motor cortex, which project to striatum, partly rescued a preferential loss of enkephalinergic striatal neurons, and enhanced substance P (SP) expression by SP striatal projection neurons. The enhanced survival of enkephalinergic striatal neurons was correlated with the cortical BDNF increase, but the enhanced SP expression by SP striatal neurons was not. Thus, LY379268 may protect the two main striatal projection neuron types by different mechanisms, enkephalinergic neurons by the trophic benefit of BDNF, and SP neurons by a mechanism not involving BDNF. The SP neuron benefit may perhaps instead involve the anti-excitotoxic action of mGluR2/3 receptor agonists.
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Affiliation(s)
- A Reiner
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, 855 Monroe Ave, Memphis, TN 38163, USA.
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Sustained expression of brain-derived neurotrophic factor is required for maintenance of dendritic spines and normal behavior. Neuroscience 2012; 212:1-18. [PMID: 22542678 DOI: 10.1016/j.neuroscience.2012.03.031] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 03/23/2012] [Accepted: 03/26/2012] [Indexed: 10/28/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) plays important roles in the development, maintenance, and plasticity of the mammalian forebrain. These functions include regulation of neuronal maturation and survival, axonal and dendritic arborization, synaptic efficacy, and modulation of complex behaviors including depression and spatial learning. Although analysis of mutant mice has helped establish essential developmental functions for BDNF, its requirement in the adult is less well documented. We have studied late-onset forebrain-specific BDNF knockout (CaMK-BDNF(KO)) mice, in which BDNF is lost primarily from the cortex and hippocampus in early adulthood, well after BDNF expression has begun in these structures. We found that although CaMK-BDNF(KO) mice grew at a normal rate and can survive more than a year, they had smaller brains than wild-type siblings. The CaMK-BDNF(KO) mice had generally normal behavior in tests for ataxia and anxiety, but displayed reduced spatial learning ability in the Morris water task and increased depression in the Porsolt swim test. These behavioral deficits were very similar to those we previously described in an early-onset forebrain-specific BDNF knockout. To identify an anatomical correlate of the abnormal behavior, we quantified dendritic spines in cortical neurons. The spine density of CaMK-BDNF(KO) mice was normal at P35, but by P84, there was a 30% reduction in spine density. The strong similarities we find between early- and late-onset BDNF knockouts suggest that BDNF signaling is required continuously in the CNS for the maintenance of some forebrain circuitry also affected by developmental BDNF depletion.
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Divergent roles of p75NTR and Trk receptors in BDNF's effects on dendritic spine density and morphology. Neural Plast 2012; 2012:578057. [PMID: 22548193 PMCID: PMC3323862 DOI: 10.1155/2012/578057] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 01/13/2012] [Accepted: 01/13/2012] [Indexed: 01/19/2023] Open
Abstract
Activation of TrkB receptors by brain-derived neurotrophic factor (BDNF) followed by MAPK/ERK signaling increases dendritic spine density and the proportion of mature spines in hippocampal CA1 pyramidal neurons. Considering the opposing actions of p75(NTR) and Trk receptors in several BDNF actions on CNS neurons, we tested whether these receptors also have divergent actions on dendritic spine density and morphology. A function-blocking anti-p75(NTR) antibody (REX) did not affect spine density by itself but it prevented BDNF's effect on spine density. Intriguingly, REX by itself increased the proportion of immature spines and prevented BDNF's effect on spine morphology. In contrast, the Trk receptor inhibitor k-252a increased spine density by itself, and prevented BDNF from further increasing spine density. However, most of the spines in k-252a-treated slices were of the immature type. These effects of k-252a on spine density and morphology required neuronal activity because they were prevented by TTX. These divergent BDNF actions on spine density and morphology are reminiscent of opposing functional signaling by p75(NTR) and Trk receptors and reveal an unexpected level of complexity in the consequences of BDNF signaling on dendritic morphology.
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Fenner BM. Truncated TrkB: beyond a dominant negative receptor. Cytokine Growth Factor Rev 2012; 23:15-24. [PMID: 22341689 DOI: 10.1016/j.cytogfr.2012.01.002] [Citation(s) in RCA: 150] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 01/13/2012] [Indexed: 12/14/2022]
Abstract
BDNF activates trkB receptors to regulate neuronal survival, differentiation, and proliferation. Mutations in the BDNF gene, altered BDNF expression, and altered trkB expression are associated with degenerative and psychiatric disorders. The full-length trkB receptor (trkB.tk(+)) undergoes autophosphorylation to activate intracellular signaling pathways. The truncated trkB receptor (trkB.t1) is abundantly expressed in the brain but lacks the catalytic tyrosine kinase domain. TrkB.t1 is a dominant-negative receptor that inhibits trkB.tk(+) signaling. While this is an important function of trkB.t1, it is only one of its many functions. TrkB.t1 sequesters and translocate BDNF, induces filopodia and neurite outgrowth, stimulates intracellular signaling cascades, regulates Rho GTPase signaling, and modifies cytoskeletal structures. TrkB.t1 is an active signaling molecule with regulatory effects on neurons and astrocytes.
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Jablonka S, Holtmann B, Sendtner M, Metzger F. Therapeutic effects of PEGylated insulin-like growth factor I in the pmn mouse model of motoneuron disease. Exp Neurol 2011; 232:261-9. [DOI: 10.1016/j.expneurol.2011.09.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 08/31/2011] [Accepted: 09/09/2011] [Indexed: 02/08/2023]
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Cesca F, Yabe A, Spencer-Dene B, Scholz-Starke J, Medrihan L, Maden CH, Gerhardt H, Orriss IR, Baldelli P, Al-Qatari M, Koltzenburg M, Adams RH, Benfenati F, Schiavo G. Kidins220/ARMS mediates the integration of the neurotrophin and VEGF pathways in the vascular and nervous systems. Cell Death Differ 2011; 19:194-208. [PMID: 22048155 DOI: 10.1038/cdd.2011.141] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Signaling downstream of receptor tyrosine kinases controls cell differentiation and survival. How signals from different receptors are integrated is, however, still poorly understood. In this work, we have identified Kidins220 (Kinase D interacting substrate of 220 kDa)/ARMS (Ankyrin repeat-rich membrane spanning) as a main player in the modulation of neurotrophin and vascular endothelial growth factor (VEGF) signaling in vivo, and a primary determinant for neuronal and cardiovascular development. Kidins220(-/-) embryos die at late stages of gestation, and show extensive cell death in the central and peripheral nervous systems. Primary neurons from Kidins220(-/-) mice exhibit reduced responsiveness to brain-derived neurotrophic factor, in terms of activation of mitogen-activated protein kinase signaling, neurite outgrowth and potentiation of excitatory postsynaptic currents. In addition, mice lacking Kidins220 display striking cardiovascular abnormalities, possibly due to impaired VEGF signaling. In support of this hypothesis, we demonstrate that Kidins220 constitutively interacts with VEGFR2. These findings, together with the data presented in the accompanying paper, indicate that Kidins220 mediates the integration of several growth factor receptor pathways during development, and mediates the activation of distinct downstream cascades according to the location and timing of stimulation.
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Affiliation(s)
- F Cesca
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, via Morego 30, 16163 Genoa, Italy.
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Gould TW, Oppenheim RW. Motor neuron trophic factors: therapeutic use in ALS? BRAIN RESEARCH REVIEWS 2011; 67:1-39. [PMID: 20971133 PMCID: PMC3109102 DOI: 10.1016/j.brainresrev.2010.10.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2010] [Revised: 10/12/2010] [Accepted: 10/18/2010] [Indexed: 12/12/2022]
Abstract
The modest effects of neurotrophic factor (NTF) treatment on lifespan in both animal models and clinical studies of Amyotropic Lateral Sclerosis (ALS) may result from any one or combination of the four following explanations: 1.) NTFs block cell death in some physiological contexts but not in ALS; 2.) NTFs do not rescue motoneurons (MNs) from death in any physiological context; 3.) NTFs block cell death in ALS but to no avail; and 4.) NTFs are physiologically effective but limited by pharmacokinetic constraints. The object of this review is to critically evaluate the role of both NTFs and the intracellular cell death pathway itself in regulating the survival of spinal and cranial (lower) MNs during development, after injury and in response to disease. Because the role of molecules mediating MN survival has been most clearly resolved by the in vivo analysis of genetically engineered mice, this review will focus on studies of such mice expressing reporter, null or other mutant alleles of NTFs, NTF receptors, cell death or ALS-associated genes.
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Affiliation(s)
- Thomas W Gould
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1010, USA.
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TrkB receptor controls striatal formation by regulating the number of newborn striatal neurons. Proc Natl Acad Sci U S A 2011; 108:1669-74. [PMID: 21205893 DOI: 10.1073/pnas.1004744108] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In the peripheral nervous system, target tissues control the final size of innervating neuronal populations by producing limited amounts of survival-promoting neurotrophic factors during development. However, it remains largely unknown if the same principle works to regulate the size of neuronal populations in the developing brain. Here we show that neurotrophin signaling mediated by the TrkB receptor controls striatal size by promoting the survival of developing medium-sized spiny neurons (MSNs). Selective deletion of the gene for the TrkB receptor in striatal progenitors, using the Dlx5/6-Cre transgene, led to a hindpaw-clasping phenotype and a 50% loss of MSNs without affecting striatal interneurons. This loss resulted mainly from increased apoptosis of newborn MSNs within their birthplace, the lateral ganglionic eminence. Among MSNs, those expressing the dopamine receptor D2 (DRD2) were most affected, as indicated by a drastic loss of these neurons and specific down-regulation of the DRD2 and enkephalin. This specific phenotype of mutant animals is likely due to preferential TrkB expression in DRD2 MSNs. These findings suggest that neurotrophins can control the size of neuronal populations in the brain by promoting the survival of newborn neurons before they migrate to their final destinations.
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Schulte J, Littleton JT. The biological function of the Huntingtin protein and its relevance to Huntington's Disease pathology. CURRENT TRENDS IN NEUROLOGY 2011; 5:65-78. [PMID: 22180703 PMCID: PMC3237673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Huntington's Disease is an adult-onset dominant heritable disorder characterized by progressive psychiatric disruption, cognitive deficits, and loss of motor coordination. It is caused by expansion of a polyglutamine tract within the N-terminal domain of the Huntingtin protein. The mutation confers a toxic gain-of-function phenotype, resulting in neurodegeneration that is most severe in the striatum. Increasing experimental evidence from genetic model systems such as mice, zebrafish, and Drosophila suggest that polyglutamine expansion within the Huntingtin protein also disrupts its normal biological function. Huntingtin is widely expressed during development and has a complex and dynamic distribution within cells. It is predicted to be a protein of pleiotropic function, interacting with a large number of effector proteins to mediate a host of physiological processes. In this review, we highlight the wildtype function of Huntingtin, focusing on its postdevelopmental roles in axonal trafficking, regulation of gene transcription, and cell survival. We then discuss how potential loss-of-function phenotypes resulting in polyglutamine expansion within Huntingtin may have direct relevance to the underlying pathophysiology of Huntington's Disease.
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Affiliation(s)
- Joost Schulte
- The Picower Institute for Learning and Memory, Departments of Biology and Brain and Cognitive Sciences, Massachusetts Institute of Technology, 43 Vassar St., 46-3251, Cambridge, MA 02139, USA
| | - J. Troy Littleton
- The Picower Institute for Learning and Memory, Departments of Biology and Brain and Cognitive Sciences, Massachusetts Institute of Technology, 43 Vassar St., 46-3251, Cambridge, MA 02139, USA
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Abstract
The structure of the brain is constantly changing from birth throughout the lifetime, meaning that normal aging, free from dementia, is associated with structural brain changes. This paper reviews recent evidence from magnetic resonance imaging (MRI) studies about age-related changes in the brain. The main conclusions are that (1) the brain shrinks in volume and the ventricular system expands in healthy aging. However, the pattern of changes is highly heterogeneous, with the largest changes seen in the frontal and temporal cortex, and in the putamen, thalamus, and accumbens. With modern approaches to analysis of MRI data, changes in cortical thickness and subcortical volume can be tracked over periods as short as one year, with annual reductions of between 0.5% and 1.0% in most brain areas. (2) The volumetric brain reductions in healthy aging are likely only to a minor extent related to neuronal loss. Rather, shrinkage of neurons, reductions of synaptic spines, and lower numbers of synapses probably account for the reductions in grey matter. In addition, the length of myelinated axons is greatly reduced, up to almost 50%. (3) Reductions in specific cognitive abilities--for instance processing speed, executive functions, and episodic memory--are seen in healthy aging. Such reductions are to a substantial degree mediated by neuroanatomical changes, meaning that between 25% and 100% of the differences between young and old participants in selected cognitive functions can be explained by group differences in structural brain characteristics.
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Affiliation(s)
- Anders M Fjell
- Center for the Study of Human Cognition, Department of Psychology, University of Oslo, Norway.
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