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Forsell P, Parrado Fernández C, Nilsson B, Sandin J, Nordvall G, Segerdahl M. Positive Allosteric Modulators of Trk Receptors for the Treatment of Alzheimer's Disease. Pharmaceuticals (Basel) 2024; 17:997. [PMID: 39204102 PMCID: PMC11357672 DOI: 10.3390/ph17080997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Revised: 07/19/2024] [Accepted: 07/25/2024] [Indexed: 09/03/2024] Open
Abstract
Neurotrophins are important regulators of neuronal and non-neuronal functions. As such, the neurotrophins and their receptors, the tropomyosin receptor kinase (Trk) family of receptor tyrosine kinases, has attracted intense research interest and their role in multiple diseases including Alzheimer's disease has been described. Attempts to administer neurotrophins to patients have been reported, but the clinical trials have so far have been hampered by side effects or a lack of clear efficacy. Thus, much of the focus during recent years has been on identifying small molecules acting as agonists or positive allosteric modulators (PAMs) of Trk receptors. Two examples of successful discovery and development of PAMs are the TrkA-PAM E2511 and the pan-Trk PAM ACD856. E2511 has been reported to have disease-modifying effects in preclinical models, whereas ACD856 demonstrates both a symptomatic and a disease-modifying effect in preclinical models. Both molecules have reached the stage of clinical development and were reported to be safe and well tolerated in clinical phase 1 studies, albeit with different pharmacokinetic profiles. These two emerging small molecules are interesting examples of possible novel symptomatic and disease-modifying treatments that could complement the existing anti-amyloid monoclonal antibodies for the treatment of Alzheimer's disease. This review aims to present the concept of positive allosteric modulators of the Trk receptors as a novel future treatment option for Alzheimer's disease and other neurodegenerative and cognitive disorders, and the current preclinical and clinical data supporting this new concept. Preclinical data indicate dual mechanisms, not only as cognitive enhancers, but also a tentative neurorestorative function.
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Affiliation(s)
- Pontus Forsell
- AlzeCure Pharma AB, Hälsovägen 7, 141 57 Huddinge, Sweden; (C.P.F.); (B.N.); (J.S.); (G.N.); (M.S.)
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Alfred Nobels allé 23, 141 52 Huddinge, Sweden
| | - Cristina Parrado Fernández
- AlzeCure Pharma AB, Hälsovägen 7, 141 57 Huddinge, Sweden; (C.P.F.); (B.N.); (J.S.); (G.N.); (M.S.)
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Alfred Nobels allé 23, 141 52 Huddinge, Sweden
| | - Boel Nilsson
- AlzeCure Pharma AB, Hälsovägen 7, 141 57 Huddinge, Sweden; (C.P.F.); (B.N.); (J.S.); (G.N.); (M.S.)
| | - Johan Sandin
- AlzeCure Pharma AB, Hälsovägen 7, 141 57 Huddinge, Sweden; (C.P.F.); (B.N.); (J.S.); (G.N.); (M.S.)
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Alfred Nobels allé 23, 141 52 Huddinge, Sweden
| | - Gunnar Nordvall
- AlzeCure Pharma AB, Hälsovägen 7, 141 57 Huddinge, Sweden; (C.P.F.); (B.N.); (J.S.); (G.N.); (M.S.)
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Alfred Nobels allé 23, 141 52 Huddinge, Sweden
| | - Märta Segerdahl
- AlzeCure Pharma AB, Hälsovägen 7, 141 57 Huddinge, Sweden; (C.P.F.); (B.N.); (J.S.); (G.N.); (M.S.)
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Alfred Nobels allé 23, 141 52 Huddinge, Sweden
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Ali NH, Al‐Kuraishy HM, Al‐Gareeb AI, Alexiou A, Papadakis M, AlAseeri AA, Alruwaili M, Saad HM, Batiha GE. BDNF/TrkB activators in Parkinson's disease: A new therapeutic strategy. J Cell Mol Med 2024; 28:e18368. [PMID: 38752280 PMCID: PMC11096816 DOI: 10.1111/jcmm.18368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 03/22/2024] [Accepted: 04/17/2024] [Indexed: 05/18/2024] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder of the brain and is manifested by motor and non-motor symptoms because of degenerative changes in dopaminergic neurons of the substantia nigra. PD neuropathology is associated with mitochondrial dysfunction, oxidative damage and apoptosis. Thus, the modulation of mitochondrial dysfunction, oxidative damage and apoptosis by growth factors could be a novel boulevard in the management of PD. Brain-derived neurotrophic factor (BDNF) and its receptor tropomyosin receptor kinase type B (TrkB) are chiefly involved in PD neuropathology. BDNF promotes the survival of dopaminergic neurons in the substantia nigra and enhances the functional activity of striatal neurons. Deficiency of the TrkB receptor triggers degeneration of dopaminergic neurons and accumulation of α-Syn in the substantia nigra. As well, BDNF/TrkB signalling is reduced in the early phase of PD neuropathology. Targeting of BDNF/TrkB signalling by specific activators may attenuate PD neuropathology. Thus, this review aimed to discuss the potential role of BDNF/TrkB activators against PD. In conclusion, BDNF/TrkB signalling is decreased in PD and linked with disease severity and long-term complications. Activation of BDNF/TrkB by specific activators may attenuate PD neuropathology.
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Affiliation(s)
- Naif H. Ali
- Department of Internal Medicine, Medical CollegeNajran UniversityNajranSaudi Arabia
| | - Hayder M. Al‐Kuraishy
- Department of Clinical Pharmacology and Medicine, College of MedicineMustansiriyah UniversityBaghdadIraq
| | | | - Athanasios Alexiou
- University Centre for Research and Development, Chandigarh UniversityMohaliPunjabIndia
- Department of Research and DevelopmentFunogenAthensGreece
- Department of Research and DevelopmentAFNP MedWienAustria
- Department of Science and EngineeringNovel Global Community Educational FoundationHebershamNew South WalesAustralia
| | - Marios Papadakis
- Department of Surgery IIUniversity Hospital Witten‐Herdecke, University of Witten‐HerdeckeWuppertalGermany
| | - Ali Abdullah AlAseeri
- Department of Internal MedicineCollege of Medicine, Prince Sattam bin Abdulaziz UniversityAl‐KharjSaudi Arabia
| | - Mubarak Alruwaili
- Department of Internal Medicine, College of MedicineJouf UniversitySakakaSaudi Arabia
| | - Hebatallah M. Saad
- Department of Pathology, Faculty of Veterinary MedicineMatrouh UniversityMatrouhEgypt
| | - Gaber El‐Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary MedicineDamanhour UniversityDamanhourEgypt
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Enkavi G, Girych M, Moliner R, Vattulainen I, Castrén E. TrkB transmembrane domain: bridging structural understanding with therapeutic strategy. Trends Biochem Sci 2024; 49:445-456. [PMID: 38433044 DOI: 10.1016/j.tibs.2024.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/19/2024] [Accepted: 02/09/2024] [Indexed: 03/05/2024]
Abstract
TrkB (neuronal receptor tyrosine kinase-2, NTRK2) is the receptor for brain-derived neurotrophic factor (BDNF) and is a critical regulator of activity-dependent neuronal plasticity. The past few years have witnessed an increasing understanding of the structure and function of TrkB, including its transmembrane domain (TMD). TrkB interacts with membrane cholesterol, which bidirectionally regulates TrkB signaling. Additionally, TrkB has recently been recognized as a binding target of antidepressant drugs. A variety of different antidepressants, including typical and rapid-acting antidepressants, as well as psychedelic compounds, act as allosteric potentiators of BDNF signaling through TrkB. This suggests that TrkB is the common target of different antidepressant compounds. Although more research is needed, current knowledge suggests that TrkB is a promising target for further drug development.
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Affiliation(s)
- Giray Enkavi
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Mykhailo Girych
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Rafael Moliner
- Neuroscience Center/HiLIFE, University of Helsinki, Helsinki, Finland
| | - Ilpo Vattulainen
- Department of Physics, University of Helsinki, Helsinki, Finland.
| | - Eero Castrén
- Neuroscience Center/HiLIFE, University of Helsinki, Helsinki, Finland.
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Wang Y, Liang J, Xu B, Yang J, Wu Z, Cheng L. TrkB/BDNF signaling pathway and its small molecular agonists in CNS injury. Life Sci 2024; 336:122282. [PMID: 38008209 DOI: 10.1016/j.lfs.2023.122282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 10/19/2023] [Accepted: 11/18/2023] [Indexed: 11/28/2023]
Abstract
As one of the most prevalent neurotrophic factors in the central nervous system (CNS), brain-derived neurotrophic factor (BDNF) plays a significant role in CNS injury by binding to its specific receptor Tropomyosin-related kinase receptor B (TrkB). The BDNF/TrkB signaling pathway is crucial for neuronal survival, structural changes, and plasticity. BDNF acts as an axonal growth and extension factor, a pro-survival factor, and a synaptic modulator in the CNS. BDNF also plays an important role in the maintenance and plasticity of neuronal circuits. Several studies have demonstrated the importance of BDNF in the treatment and recovery of neurodegenerative and neurotraumatic disorders. By undertaking in-depth study on the mechanism of BDNF/TrkB function, important novel therapeutic strategies for treating neuropsychiatric disorders have been discovered. In this review, we discuss the expression patterns and mechanisms of the TrkB/BDNF signaling pathway in CNS damage and introduce several intriguing small molecule TrkB receptor agonists produced over the previous several decades.
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Affiliation(s)
- Yujin Wang
- Division of Spine, Department of Orthopedics, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China; Key Laboratory of Spine and Spinal cord Injury Repair and Regeneration (Tongji University), Ministry of Education, Shanghai 200072, China; Medical School, Tongji University, Shanghai 200433, China
| | - Jing Liang
- Division of Spine, Department of Orthopedics, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China; Key Laboratory of Spine and Spinal cord Injury Repair and Regeneration (Tongji University), Ministry of Education, Shanghai 200072, China; School of Stomatology, Tongji University, Shanghai 200072, China
| | - Boyu Xu
- Division of Spine, Department of Orthopedics, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China; Key Laboratory of Spine and Spinal cord Injury Repair and Regeneration (Tongji University), Ministry of Education, Shanghai 200072, China; Medical School, Tongji University, Shanghai 200433, China
| | - Jin Yang
- Division of Spine, Department of Orthopedics, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China; Key Laboratory of Spine and Spinal cord Injury Repair and Regeneration (Tongji University), Ministry of Education, Shanghai 200072, China; Medical School, Tongji University, Shanghai 200433, China
| | - Zhourui Wu
- Division of Spine, Department of Orthopedics, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China; Key Laboratory of Spine and Spinal cord Injury Repair and Regeneration (Tongji University), Ministry of Education, Shanghai 200072, China.
| | - Liming Cheng
- Division of Spine, Department of Orthopedics, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China; Key Laboratory of Spine and Spinal cord Injury Repair and Regeneration (Tongji University), Ministry of Education, Shanghai 200072, China.
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Basavarajappa D, Galindo-Romero C, Gupta V, Agudo-Barriuso M, Gupta VB, Graham SL, Chitranshi N. Signalling pathways and cell death mechanisms in glaucoma: Insights into the molecular pathophysiology. Mol Aspects Med 2023; 94:101216. [PMID: 37856930 DOI: 10.1016/j.mam.2023.101216] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 09/25/2023] [Accepted: 10/02/2023] [Indexed: 10/21/2023]
Abstract
Glaucoma is a complex multifactorial eye disease manifesting in retinal ganglion cell (RGC) death and optic nerve degeneration, ultimately causing irreversible vision loss. Research in recent years has significantly enhanced our understanding of RGC degenerative mechanisms in glaucoma. It is evident that high intraocular pressure (IOP) is not the only contributing factor to glaucoma pathogenesis. The equilibrium of pro-survival and pro-death signalling pathways in the retina strongly influences the function and survival of RGCs and optic nerve axons in glaucoma. Molecular evidence from human retinal tissue analysis and a range of experimental models of glaucoma have significantly contributed to unravelling these mechanisms. Accumulating evidence reveals a wide range of molecular signalling pathways that can operate -either alone or via intricate networks - to induce neurodegeneration. The roles of several molecules, including neurotrophins, interplay of intracellular kinases and phosphates, caveolae and adapter proteins, serine proteases and their inhibitors, nuclear receptors, amyloid beta and tau, and how their dysfunction affects retinal neurons are discussed in this review. We further underscore how anatomical alterations in various animal models exhibiting RGC degeneration and susceptibility to glaucoma-related neuronal damage have helped to characterise molecular mechanisms in glaucoma. In addition, we also present different regulated cell death pathways that play a critical role in RGC degeneration in glaucoma.
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Affiliation(s)
- Devaraj Basavarajappa
- Macquarie Medical School, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia.
| | - Caridad Galindo-Romero
- Experimental Ophthalmology Group, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca) & Ophthalmology Department, Universidad de Murcia, Murcia, Spain
| | - Vivek Gupta
- Macquarie Medical School, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Marta Agudo-Barriuso
- Experimental Ophthalmology Group, Instituto Murciano de Investigación Biosanitaria Virgen de la Arrixaca (IMIB-Arrixaca) & Ophthalmology Department, Universidad de Murcia, Murcia, Spain
| | - Veer B Gupta
- School of Medicine, Deakin University, Melbourne, VIC, Australia
| | - Stuart L Graham
- Macquarie Medical School, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Nitin Chitranshi
- Macquarie Medical School, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia.
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Vink HA, Ramekers D, Foster AC, Versnel H. The efficacy of a TrkB monoclonal antibody agonist in preserving the auditory nerve in deafened guinea pigs. Hear Res 2023; 439:108895. [PMID: 37837701 DOI: 10.1016/j.heares.2023.108895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 08/31/2023] [Accepted: 10/02/2023] [Indexed: 10/16/2023]
Abstract
The auditory nerve typically degenerates following loss of cochlear hair cells or synapses. In the case of hair cell loss neural degeneration hinders restoration of hearing through a cochlear implant, and in the case of synaptopathy suprathreshold hearing is affected, potentially degrading speech perception in noise. It has been established that neurotrophins such as brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) can mitigate auditory nerve degeneration. Several potential BDNF mimetics have also been investigated for neurotrophic effects in the cochlea. A recent in vitro study showed favorable effects of M3, a TrkB monoclonal antibody agonist, when compared with BDNF. In the present study we set out to examine the effect of M3 on auditory nerve preservation in vivo. Thirty-one guinea pigs were bilaterally deafened, and unilaterally treated with a single 3-µl dose of 7 mg/ml, 0.7 mg/ml M3 or vehicle-only by means of a small gelatin sponge two weeks later. During the experiment and analyses the experimenters were blinded to the three treatment groups. Four weeks after treatment, we assessed the treatment effect (1) histologically, by quantifying survival of SGCs and their peripheral processes (PPs); and (2) electrophysiologically, with two different paradigms of electrically evoked compound action potential (eCAP) recordings shown to be indicative of neural health: single-pulse stimulation with varying inter-phase gap (IPG), and pulse-train stimulation with varying inter-pulse interval. We observed a consistent and significant preservative effect of M3 on SGC survival in the lower basal turn (approximately 40% more survival than in the untreated contralateral cochlea), but also in the upper middle and lower apical turn of the cochlea. This effect was similar for the two treatment groups. Survival of PPs showed a trend similar to that of the SGCs, but was only significantly higher for the highest dose of M3. The protective effect of M3 on SGCs was not reflected in any of the eCAP measures: no statistically significant differences were observed between groups in IPG effect nor between the M3 treatment groups and the control group using the pulse-train stimulation paradigm. In short, while a clear effect of M3 was observed on SGC survival, this was not clearly translated into functional preservation.
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Affiliation(s)
- Henk A Vink
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, the Netherlands; UMC Utrecht Brain Center, Utrecht University, Utrecht, the Netherlands
| | - Dyan Ramekers
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, the Netherlands; UMC Utrecht Brain Center, Utrecht University, Utrecht, the Netherlands
| | | | - Huib Versnel
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, the Netherlands; UMC Utrecht Brain Center, Utrecht University, Utrecht, the Netherlands.
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7
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Mishra K, Rana R, Tripathi S, Siddiqui S, Yadav PK, Yadav PN, Chourasia MK. Recent Advancements in Nanocarrier-assisted Brain Delivery of Phytochemicals Against Neurological Diseases. Neurochem Res 2023; 48:2936-2968. [PMID: 37278860 DOI: 10.1007/s11064-023-03955-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 05/12/2023] [Accepted: 05/18/2023] [Indexed: 06/07/2023]
Abstract
Despite ongoing advancements in research, the inability of therapeutics to cross the blood-brain barrier (BBB) makes the treatment of neurological disorders (NDs) a challenging task, offering only partial symptomatic relief. Various adverse effects associated with existing approaches are another significant barrier that prompts the usage of structurally diverse phytochemicals as preventive/therapeutic lead against NDs in preclinical and clinical settings. Despite numerous beneficial properties, phytochemicals suffer from poor pharmacokinetic profile which limits their pharmacological activity and necessitates the utility of nanotechnology for efficient drug delivery. Nanocarriers have been shown to be proficient carriers that can enhance drug delivery, bioavailability, biocompatibility, and stability of phytochemicals. We, thus, conducted a meticulous literature survey using several electronic databases to gather relevant studies in order to provide a comprehensive summary about the use of nanocarriers in delivering phytochemicals as a treatment approach for NDs. Additionally, the review highlights the mechanisms of drug transport of nanocarriers across the BBB and explores their potential future applications in this emerging field.
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Affiliation(s)
- Keerti Mishra
- Division of Pharmaceutics and Pharmacokinetics, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Rafquat Rana
- Division of Pharmaceutics and Pharmacokinetics, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Shourya Tripathi
- Division of Pharmaceutics and Pharmacokinetics, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Shumaila Siddiqui
- Division of Cancer Biology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Pavan K Yadav
- Division of Pharmaceutics and Pharmacokinetics, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Prem N Yadav
- Division of Neuro Science & Ageing Biology, CSIR-Central Drug Research Institute, Lucknow, 226031, Uttar Pradesh, India
| | - Manish K Chourasia
- Division of Pharmaceutics and Pharmacokinetics, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India.
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Nishijima E, Honda S, Kitamura Y, Namekata K, Kimura A, Guo X, Azuchi Y, Harada C, Murakami A, Matsuda A, Nakano T, Parada LF, Harada T. Vision protection and robust axon regeneration in glaucoma models by membrane-associated Trk receptors. Mol Ther 2023; 31:810-824. [PMID: 36463402 PMCID: PMC10014229 DOI: 10.1016/j.ymthe.2022.11.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/14/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
Activation of neurotrophic factor signaling is a promising therapy for neurodegeneration. However, the transient nature of ligand-dependent activation limits its effectiveness. In this study, we solved this problem by inventing a system that forces membrane localization of the intracellular domain of tropomyosin receptor kinase B (iTrkB), which results in constitutive activation without ligands. Our system overcomes the small size limitation of the genome packaging in adeno-associated virus (AAV) and allows high expression of the transgene. Using AAV-mediated gene therapy in the eyes, we demonstrate that iTrkB expression enhances neuroprotection in mouse models of glaucoma and stimulates robust axon regeneration after optic nerve injury. In addition, iTrkB expression in the retina was also effective in an optic tract transection model, in which the injury site is near the superior colliculus. Regenerating axons successfully formed pathways to their brain targets, resulting in partial recovery of visual behavior. Our system may also be applicable to other trophic factor signaling pathways and lead to a significant advance in the field of gene therapy for neurotrauma and neurodegenerative disorders, including glaucoma.
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Affiliation(s)
- Euido Nishijima
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan; Department of Ophthalmology, The Jikei University School of Medicine, Minato-ku, Tokyo 105-8461, Japan
| | - Sari Honda
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan; Department of Ophthalmology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Yuta Kitamura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan; Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chiba, Chiba 260-8670, Japan
| | - Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan
| | - Atsuko Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan
| | - Xiaoli Guo
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan
| | - Yuriko Azuchi
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan
| | - Chikako Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan
| | - Akira Murakami
- Department of Ophthalmology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Akira Matsuda
- Department of Ophthalmology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Tadashi Nakano
- Department of Ophthalmology, The Jikei University School of Medicine, Minato-ku, Tokyo 105-8461, Japan
| | - Luis F Parada
- Brain Tumor Center and Cancer Biology & Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan.
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Sharma V, Singh TG, Kaur A, Mannan A, Dhiman S. Brain-Derived Neurotrophic Factor: A Novel Dynamically Regulated Therapeutic Modulator in Neurological Disorders. Neurochem Res 2023; 48:317-339. [PMID: 36308619 DOI: 10.1007/s11064-022-03755-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 09/02/2022] [Accepted: 09/03/2022] [Indexed: 02/04/2023]
Abstract
The growth factor brain-derived neurotrophic factor (BDNF), and its receptor tropomyosin-related kinase receptor type B (TrkB) play an active role in numerous areas of the adult brain, where they regulate the neuronal activity, function, and survival. Upregulation and downregulation of BDNF expression are critical for the physiology of neuronal circuits and functioning in the brain. Loss of BDNF function has been reported in the brains of patients with neurodegenerative or psychiatric disorders. This article reviews the BDNF gene structure, transport, secretion, expression and functions in the brain. This article also implicates BDNF in several brain-related disorders, including Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, major depressive disorder, schizophrenia, epilepsy and bipolar disorder.
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Affiliation(s)
- Veerta Sharma
- Chitkara College of Pharmacy, Chitkara University, 140401, Rajpura, Punjab, India
| | - Thakur Gurjeet Singh
- Chitkara College of Pharmacy, Chitkara University, 140401, Rajpura, Punjab, India.
| | - Amarjot Kaur
- Chitkara College of Pharmacy, Chitkara University, 140401, Rajpura, Punjab, India
| | - Ashi Mannan
- Chitkara College of Pharmacy, Chitkara University, 140401, Rajpura, Punjab, India
| | - Sonia Dhiman
- Chitkara College of Pharmacy, Chitkara University, 140401, Rajpura, Punjab, India
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Abstract
The limonoids have attracted significant attention from the synthetic community owing to their striking structural complexity and medicinal potential. Recent efforts notwithstanding, synthetic access to many intact or ring D-seco limonoids still remains elusive. Here, we report the first de novo synthesis of gedunin, a ring D-seco limonoid with HSP90 inhibitory activity, that proceeds in 13 steps. Two enabling features in our strategy are the application of modern catalytic transformations to set the key quaternary centers in the carbocyclic core and the use of biocatalytic oxidation at C3 to establish a chemical handle to access the A-ring enone motif. The strategy presented herein may provide an entry point to a wider range of oxidized limonoids.
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Affiliation(s)
- Jian Li
- Department of Chemistry, BioScience Research Collaborative, Rice University, Houston, Texas 77005, United States
| | - Fang Chen
- Department of Chemistry, BioScience Research Collaborative, Rice University, Houston, Texas 77005, United States
| | - Hans Renata
- Department of Chemistry, BioScience Research Collaborative, Rice University, Houston, Texas 77005, United States
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Nordvall G, Forsell P, Sandin J. Neurotrophin-targeted therapeutics: A gateway to cognition and more? Drug Discov Today 2022; 27:103318. [PMID: 35850433 DOI: 10.1016/j.drudis.2022.07.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/05/2022] [Accepted: 07/12/2022] [Indexed: 02/09/2023]
Abstract
Neurotrophins, such as brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), are small proteins expressed in the brain and peripheral tissues, which regulate several key aspects of neuronal function, including neurogenesis, synaptic plasticity and neuroprotection, but also programmed cell death. This broad range of effects is a result of a complex downstream signaling pathway, with differential spatial and temporal activation patterns further diversifying their physiological effects. Alterations in neurotrophin levels, or known polymorphisms in neurotrophin genes, have been linked to a variety of disorders, including depression and Alzheimer's disease (AD). Historically, their therapeutic potential in these disorders has been hampered by the lack of suitable tool molecules for clinical studies. However, recent advancements have led to the development of new therapeutic candidates, which are now in clinical testing.
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English AW, Carrasco D, Hoffman D, Isaacson R, Kang SS, Khan S, Liu X, Ye K. Oral Treatments With the TrkB Ligand Prodrug, R13, Promote Enhanced Axon Regeneration Following Peripheral Nerve Injury. Front Cell Neurosci 2022; 16:857664. [PMID: 35496909 PMCID: PMC9051483 DOI: 10.3389/fncel.2022.857664] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/24/2022] [Indexed: 11/16/2022] Open
Abstract
Axon regeneration after peripheral nerve injury is slow and inefficient, leading to generally poor functional recovery. Activity-dependent experimental therapies that increase expression of brain-derived neurotrophic factor (BDNF) and its TrkB receptors enhance regeneration, suggesting that treatments with BDNF might also be effective. However, recombinant human BDNF (rhBDNF), as well as 7,8-dihydroxyflavone (7,8-DHF), a small molecular BDNF mimetic, may have limited treatment applications because of their modest oral bioavailability and pharmacokinetic profile. R13 is a 7,8-DHF prodrug. Upon oral administration, it is converted in the liver to 7,8-DHF. In immunoblots from tissues at the site of nerve injury, a single oral treatment with R13 to mice following sciatic nerve transection and repair produced a rapid and prolonged increase in immunoreactivity to phosphorylated TrkB, prolonged phosphorylation of mitogen activated protein kinase (MAPK/Erk1/2), and a rapid but transient increase in phosphorylated AKT (protein kinase B). Intramuscular injections of fluorescent retrograde tracers into the gastrocnemius and tibialis anterior muscles 4 weeks after nerve injury resulted in significantly greater numbers of labeled motoneurons and dorsal root ganglion neurons in R13-treated mice than in vehicle-treated controls. Direct electromyographic (EMG) responses (M waves) were significantly larger in R13-treated mice 4 weeks after injury than vehicle-treated controls or mice treated with oral 7,8-DHF. Oral treatments with the prodrug, R13, are a potent therapy for stimulating axon regeneration and functional recovery after peripheral nerve injury.
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Affiliation(s)
- Arthur W. English
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, United States
- Rehabilitation Medicine, Emory University School of Medicine, Atlanta, GA, United States
- *Correspondence: Arthur W. English,
| | - Dario Carrasco
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Dustin Hoffman
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Robin Isaacson
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Seong Su Kang
- Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, United States
| | - Samia Khan
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Xia Liu
- Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, United States
| | - Keqiang Ye
- Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, United States
- Faculty of Life and Health Sciences, Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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Do Small Molecules Activate the TrkB Receptor in the Same Manner as BDNF? Limitations of Published TrkB Low Molecular Agonists and Screening for Novel TrkB Orthosteric Agonists. Pharmaceuticals (Basel) 2021; 14:ph14080704. [PMID: 34451801 PMCID: PMC8398766 DOI: 10.3390/ph14080704] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 12/24/2022] Open
Abstract
TrkB is a tyrosine kinase receptor that is activated upon binding to brain-derived neurotrophic factor (BDNF). To date, the search for low-molecular-weight molecules mimicking BDNF’s action has been unsuccessful. Several molecules exerting antidepressive effects in vivo, such as 7,8-DHF, have been suggested to be TrkB agonists. However, more recent publications question this hypothesis. In this study, we developed a set of experimental procedures including the evaluation of direct interactions, dimerization, downstream signaling, and cytoprotection in parallel with physicochemical and ADME methods to verify the pharmacology of 7,8-DHF and other potential reference compounds, and perform screening for novel TrkB agonists. 7,8 DHF bound to TrkB with Kd = 1.3 μM; however, we were not able to observe any other activity against the TrkB receptor in SN56 T48 and differentiated SH-SY5Y cell lines. Moreover, the pharmacokinetic and pharmacodynamic effects of 7,8-DHF at doses of 1 and 50 mg/kg were examined in mice after i.v and oral administration, respectively. The poor pharmacokinetic properties and lack of observed activation of TrkB-dependent signaling in the brain confirmed that 7,8-DHF is not a relevant tool for studying TrkB activation in vivo. The binding profile for 133 molecular targets revealed a significant lack of selectivity of 7,8-DHF, suggesting a distinct functional profile independent of interaction with TrkB. Additionally, a compound library was screened in search of novel low-molecular-weight orthosteric TrkB agonists; however, we were not able to identify reliable drug candidates. Our results suggest that published reference compounds including 7,8-DHF do not activate TrkB, consistent with canonical dogma, which indicates that the reported pharmacological activity of these compounds should be interpreted carefully in a broad functional context.
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Sandhir R, Khurana M, Singhal NK. Potential benefits of phytochemicals from Azadirachta indica against neurological disorders. Neurochem Int 2021; 146:105023. [PMID: 33753160 DOI: 10.1016/j.neuint.2021.105023] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 03/12/2021] [Accepted: 03/14/2021] [Indexed: 12/16/2022]
Abstract
Azadirachta indica or Neem has been extensively used in the Indian traditional medical system because of its broad range of medicinal properties. Neem contains many chemically diverse and structurally complex phytochemicals such as limonoids, flavonoids, phenols, catechins, gallic acid, polyphenols, nimbins. These phytochemicals possess vast array of therapeutic activities that include anti-feedant, anti-viral, anti-malarial, anti-bacterial, anti-cancer properties. In recent years, many phytochemicals from Neem have been shown to be beneficial against various neurological disorders like Alzheimer's and Parkinson's disease, mood disorders, ischemic-reperfusion injury. The neuroprotective effects of the phytochemicals from Neem are primarily mediated by their anti-oxidant, anti-inflammatory and anti-apoptotic activities along with their ability to modulate signaling pathways. However, extensive studies are still required to fully understand the molecular mechanisms involved in neuropotective effects of phytochemicals from Neem. This review is an attempt to cover the neuroprotective properties of various phytochemicals from Neem along with their mechanism of action so that the potential of the compounds could be realized to reduce the burden of neurodegenerative diseases.
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Affiliation(s)
- Rajat Sandhir
- Department of Biochemistry, Basic Medical Science Block-II, Panjab University, Chandigarh, 160014, India.
| | - Mehak Khurana
- Department of Biochemistry, Basic Medical Science Block-II, Panjab University, Chandigarh, 160014, India
| | - Nitin Kumar Singhal
- National Agri-Food Biotechnology Institute (NABI) Sector-81 (Knowledge City), PO Manauli, S.A.S. Nagar, Mohali, 140306, Punjab, India
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15
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Kang YJ, Diep YN, Tran M, Cho H. Therapeutic Targeting Strategies for Early- to Late-Staged Alzheimer's Disease. Int J Mol Sci 2020; 21:E9591. [PMID: 33339351 PMCID: PMC7766709 DOI: 10.3390/ijms21249591] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 11/30/2020] [Accepted: 12/08/2020] [Indexed: 02/08/2023] Open
Abstract
Alzheimer's disease (AD) is the most common cause of dementia, typically showing progressive neurodegeneration in aging brains. The key signatures of the AD progression are the deposition of amyloid-beta (Aβ) peptides, the formation of tau tangles, and the induction of detrimental neuroinflammation leading to neuronal loss. However, conventional pharmacotherapeutic options are merely relying on the alleviation of symptoms that are limited to mild to moderate AD patients. Moreover, some of these medicines discontinued to use due to either the insignificant effectiveness in improving the cognitive impairment or the adverse side effects worsening essential bodily functions. One of the reasons for the failure is the lack of knowledge on the underlying mechanisms that can accurately explain the major causes of the AD progression correlating to the severity of AD. Therefore, there is an urgent need for the better understanding of AD pathogenesis and the development of the disease-modifying treatments, particularly for severe and late-onset AD, which have not been covered thoroughly. Here, we review the underlying mechanisms of AD progression, which have been employed for the currently established therapeutic strategies. We believe this will further spur the discovery of a novel disease-modifying treatment for mild to severe, as well as early- to late-onset, AD.
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Affiliation(s)
- You Jung Kang
- Department of Mechanical Engineering and Engineering Science, Center for Biomedical Engineering and Science, University of North Carolina, Charlotte, NC 28223, USA;
- Department of Biological Sciences, Center for Biomedical Engineering and Science, University of North Carolina, Charlotte, NC 28223, USA
| | - Yen N. Diep
- Institute of Quantum Biophysics, Department of Biophysics, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Korea; (Y.N.D.); (M.T.)
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Korea
| | - Minh Tran
- Institute of Quantum Biophysics, Department of Biophysics, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Korea; (Y.N.D.); (M.T.)
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Korea
| | - Hansang Cho
- Institute of Quantum Biophysics, Department of Biophysics, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Korea; (Y.N.D.); (M.T.)
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Korea
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Al-Yozbaki M, Acha-Sagredo A, George A, Liloglou T, Wilson CM. Balancing neurotrophin pathway and sortilin function: Its role in human disease. Biochim Biophys Acta Rev Cancer 2020; 1874:188429. [DOI: 10.1016/j.bbcan.2020.188429] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/12/2020] [Accepted: 09/02/2020] [Indexed: 01/03/2023]
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BDNF Outperforms TrkB Agonist 7,8,3'-THF in Preserving the Auditory Nerve in Deafened Guinea Pigs. Brain Sci 2020; 10:brainsci10110787. [PMID: 33126525 PMCID: PMC7692073 DOI: 10.3390/brainsci10110787] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/23/2020] [Accepted: 10/27/2020] [Indexed: 02/06/2023] Open
Abstract
In deaf subjects using a cochlear implant (CI) for hearing restoration, the auditory nerve is subject to degeneration, which may negatively impact CI effectiveness. This nerve degeneration can be reduced by neurotrophic treatment. Here, we compare the preservative effects of the naturally occurring tyrosine receptor kinase B (TrkB) agonist brain-derived neurotrophic factor (BDNF) and the small-molecule TrkB agonist 7,8,3′-trihydroxyflavone (THF) on the auditory nerve in deafened guinea pigs. THF may be more effective than BDNF throughout the cochlea because of better pharmacokinetic properties. The neurotrophic compounds were delivered by placement of a gelatin sponge on the perforated round window membrane. To complement the histology of spiral ganglion cells (SGCs), electrically evoked compound action potential (eCAP) recordings were performed four weeks after treatment initiation. We analyzed the eCAP inter-phase gap (IPG) effect and measures derived from pulse-train evoked eCAPs, both indicative of SGC healthiness. BDNF but not THF yielded a significantly higher survival of SGCs in the basal cochlear turn than untreated controls. Regarding IPG effect and pulse-train responses, the BDNF-treated animals exhibited more normal responses than both untreated and THF-treated animals. We have thus confirmed the protective effect of BDNF, but we have not confirmed previously reported protective effects of THF with our clinically applicable delivery method.
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Frick C, Fink S, Schmidbauer D, Rousset F, Eickhoff H, Tropitzsch A, Kramer B, Senn P, Glueckert R, Rask-Andersen H, Wiesmüller KH, Löwenheim H, Müller M. Age-Dependency of Neurite Outgrowth in Postnatal Mouse Cochlear Spiral Ganglion Explants. Brain Sci 2020; 10:E580. [PMID: 32839381 PMCID: PMC7564056 DOI: 10.3390/brainsci10090580] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The spatial gap between cochlear implants (CIs) and the auditory nerve limits frequency selectivity as large populations of spiral ganglion neurons (SGNs) are electrically stimulated synchronously. To improve CI performance, a possible strategy is to promote neurite outgrowth toward the CI, thereby allowing a discrete stimulation of small SGN subpopulations. Brain-derived neurotrophic factor (BDNF) is effective to stimulate neurite outgrowth from SGNs. METHOD TrkB (tropomyosin receptor kinase B) agonists, BDNF, and five known small-molecule BDNF mimetics were tested for their efficacy in stimulating neurite outgrowth in postnatal SGN explants. To modulate Trk receptor-mediated effects, TrkB and TrkC ligands were scavenged by an excess of recombinant receptor proteins. The pan-Trk inhibitor K252a was used to block Trk receptor actions. RESULTS THF (7,8,3'-trihydroxyflavone) partly reproduced the BDNF effect in postnatal day 7 (P7) mouse cochlear spiral ganglion explants (SGEs), but failed to show effectiveness in P4 SGEs. During the same postnatal period, spontaneous and BDNF-stimulated neurite outgrowth increased. The increased neurite outgrowth in P7 SGEs was not caused by the TrkB/TrkC ligands, BDNF and neurotrophin-3 (NT-3). CONCLUSIONS The age-dependency of induction of neurite outgrowth in SGEs was very likely dependent on presently unidentified factors and/or molecular mechanisms which may also be decisive for the age-dependent efficacy of the small-molecule TrkB receptor agonist THF.
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Affiliation(s)
- Claudia Frick
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen Medical Center, 72076 Tübingen, Germany; (C.F.); (A.T.); (B.K.); (H.L.); (M.M.)
- Department of Microbiome Science, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Stefan Fink
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen Medical Center, 72076 Tübingen, Germany; (C.F.); (A.T.); (B.K.); (H.L.); (M.M.)
| | - Dominik Schmidbauer
- Inner Ear Laboratory Innsbruck, Medical University Innsbruck, 6020 Innsbruck, Austria; (D.S.); (R.G.)
| | - Francis Rousset
- The Inner Ear & Olfaction Lab, Department of Clinical Neurosciences, Faculty of Medicine, University of Geneva, 1206 Geneva, Switzerland; (F.R.); (P.S.)
| | - Holger Eickhoff
- EMC Microcollections GmbH, 72070 Tübingen, Germany; (H.E.); (K.-H.W.)
| | - Anke Tropitzsch
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen Medical Center, 72076 Tübingen, Germany; (C.F.); (A.T.); (B.K.); (H.L.); (M.M.)
| | - Benedikt Kramer
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen Medical Center, 72076 Tübingen, Germany; (C.F.); (A.T.); (B.K.); (H.L.); (M.M.)
- Department of Otolaryngology, Head and Neck Surgery, University Hospital Mannheim, 68167 Mannheim, Germany
| | - Pascal Senn
- The Inner Ear & Olfaction Lab, Department of Clinical Neurosciences, Faculty of Medicine, University of Geneva, 1206 Geneva, Switzerland; (F.R.); (P.S.)
| | - Rudolf Glueckert
- Inner Ear Laboratory Innsbruck, Medical University Innsbruck, 6020 Innsbruck, Austria; (D.S.); (R.G.)
- Tirol Kliniken Innsbruck, University Clinic of Otolaryngology, 6020 Innsbruck, Austria
| | - Helge Rask-Andersen
- Department of Surgical Sciences, Otorhinolaryngology and Head and Neck Surgery, University of Uppsala, 751 85 Uppsala, Sweden;
| | | | - Hubert Löwenheim
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen Medical Center, 72076 Tübingen, Germany; (C.F.); (A.T.); (B.K.); (H.L.); (M.M.)
| | - Marcus Müller
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen Medical Center, 72076 Tübingen, Germany; (C.F.); (A.T.); (B.K.); (H.L.); (M.M.)
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Kipnis PA, Sullivan BJ, Carter BM, Kadam SD. TrkB agonists prevent postischemic emergence of refractory neonatal seizures in mice. JCI Insight 2020; 5:136007. [PMID: 32427585 DOI: 10.1172/jci.insight.136007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 05/14/2020] [Indexed: 12/19/2022] Open
Abstract
Refractory neonatal seizures do not respond to first-line antiseizure medications like phenobarbital (PB), a positive allosteric modulator for GABAA receptors. GABAA receptor-mediated inhibition is dependent upon electroneutral cation-chloride transporter KCC2, which mediates neuronal chloride extrusion and its age-dependent increase and postnatally shifts GABAergic signaling from depolarizing to hyperpolarizing. Brain-derived neurotropic factor-tyrosine receptor kinase B activation (BDNF-TrkB activation) after excitotoxic injury recruits downstream targets like PLCγ1, leading to KCC2 hypofunction. Here, the antiseizure efficacy of TrkB agonists LM22A-4, HIOC, and deoxygedunin (DG) on PB-refractory seizures and postischemic TrkB pathway activation was investigated in a mouse model (CD-1, P7) of refractory neonatal seizures. LM, a BDNF loop II mimetic, rescued PB-refractory seizures in a sexually dimorphic manner. Efficacy was associated with a substantial reduction in the postischemic phosphorylation of TrkB at Y816, a site known to mediate postischemic KCC2 hypofunction via PLCγ1 activation. LM rescued ischemia-induced phospho-KCC2-S940 dephosphorylation, preserving its membrane stability. Full TrkB agonists HIOC and DG similarly rescued PB refractoriness. Chemogenetic inactivation of TrkB substantially reduced postischemic neonatal seizure burdens at P7. Sex differences identified in developmental expression profiles of TrkB and KCC2 may underlie the sexually dimorphic efficacy of LM. These results support a potentially novel role for the TrkB receptor in the emergence of age-dependent refractory neonatal seizures.
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Affiliation(s)
- Pavel A Kipnis
- Neuroscience Laboratory, Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Brennan J Sullivan
- Neuroscience Laboratory, Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Brandon M Carter
- Neuroscience Laboratory, Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Shilpa D Kadam
- Neuroscience Laboratory, Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland, USA.,Department of Neurology and Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Wang S, Yao H, Xu Y, Hao R, Zhang W, Liu H, Huang Y, Guo W, Lu B. Therapeutic potential of a TrkB agonistic antibody for Alzheimer's disease. Theranostics 2020; 10:6854-6874. [PMID: 32550908 PMCID: PMC7295064 DOI: 10.7150/thno.44165] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 05/11/2020] [Indexed: 12/26/2022] Open
Abstract
Repeated failures of "Aβ-lowering" therapies call for new targets and therapeutic approaches for Alzheimer's disease (AD). We propose to treat AD by halting neuronal death and repairing synapses using a BDNF-based therapy. To overcome the poor druggability of BDNF, we have developed an agonistic antibody AS86 to mimic the function of BDNF, and evaluate its therapeutic potential for AD. Method: Biochemical, electrophysiological and behavioral techniques were used to investigate the effects of AS86 in vitro and in vivo. Results: AS86 specifically activated the BDNF receptor TrkB and its downstream signaling, without affecting its other receptor p75NTR. It promoted neurite outgrowth, enhanced spine growth and prevented Aβ-induced cell death in cultured neurons, and facilitated Long-Term Potentiation (LTP) in hippocampal slices. A single-dose tail-vein injection of AS86 activated TrkB signaling in the brain, with a half-life of 6 days in the blood and brain. Bi-weekly peripheral administration of AS86 rescued the deficits in object-recognition memory in the APP/PS1 mouse model. AS86 also reversed spatial memory deficits in the 11-month, but not 14-month old AD mouse model. Conclusion: These results demonstrate the potential of AS86 in AD therapy, suggesting that neuronal and/or synaptic repair as an alternative therapeutic strategy for AD.
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Affiliation(s)
- Shudan Wang
- School of Pharmaceutical Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China, 100084
- Beijing Tiantan Hospital, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China, 100070
- R&D Center for the Diagnosis and Treatment of Major Brain Diseases, Research Institute of Tsinghua University in Shenzhen, Shenzhen, Guangdong, China, 518057
| | - Hongyang Yao
- School of Pharmaceutical Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China, 100084
| | - Yihua Xu
- School of Pharmaceutical Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China, 100084
- R&D Center for the Diagnosis and Treatment of Major Brain Diseases, Research Institute of Tsinghua University in Shenzhen, Shenzhen, Guangdong, China, 518057
| | - Rui Hao
- Center of Translational Medicine, Tongji Hospital, Tongji University School of Medicine, Shanghai, China, 200065
| | - Wen Zhang
- School of Pharmaceutical Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China, 100084
| | - Hang Liu
- School of Pharmaceutical Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China, 100084
- R&D Center for the Diagnosis and Treatment of Major Brain Diseases, Research Institute of Tsinghua University in Shenzhen, Shenzhen, Guangdong, China, 518057
| | - Ying Huang
- Center of Translational Medicine, Tongji Hospital, Tongji University School of Medicine, Shanghai, China, 200065
| | - Wei Guo
- School of Pharmaceutical Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China, 100084
- Beijing Tiantan Hospital, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China, 100070
- R&D Center for the Diagnosis and Treatment of Major Brain Diseases, Research Institute of Tsinghua University in Shenzhen, Shenzhen, Guangdong, China, 518057
| | - Bai Lu
- School of Pharmaceutical Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China, 100084
- Beijing Tiantan Hospital, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China, 100070
- R&D Center for the Diagnosis and Treatment of Major Brain Diseases, Research Institute of Tsinghua University in Shenzhen, Shenzhen, Guangdong, China, 518057
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3β, 6β-dichloro-5-hydroxy-5α-cholestane facilitates neuronal development through modulating TrkA signaling regulated proteins in primary hippocampal neuron. Sci Rep 2019; 9:18919. [PMID: 31831796 PMCID: PMC6908615 DOI: 10.1038/s41598-019-55364-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 11/27/2019] [Indexed: 12/11/2022] Open
Abstract
Potentiating neuritogenesis through pharmacological intervention might hold therapeutic promise in neurodegenerative disorders and acute brain injury. Here, we investigated the novel neuritogenic potentials of a steroidal chlorohydrin, 3β, 6β-dichloro-5-hydroxy-5α-cholestane (hereafter, SCH) and the change in cellular proteome to gain insight into the underlying mechanism of its neurotrophic activity in hippocampal neurons. Morphometric analysis showed that SCH promoted early neuronal differentiation, dendritic arborization and axonal maturation. Proteomic and bioinformatic analysis revealed that SCH induced upregulation of several proteins, including those associated with neuronal differentiation and development. Immunocytochemical data further indicates that SCH-treated neurons showed upregulation of Hnrnpa2b1 and Map1b, validating their proteomic profiles. In addition, a protein-protein interaction network analysis identified TrkA as a potential target connecting most of the upregulated proteins. The neurite outgrowth effect of SCH was suppressed by TrkA inhibitor, GW441756, verifying TrkA-dependent activity of SCH, which further supports the connection of TrkA with the upregulated proteins. Also, the computational analysis revealed that SCH interacts with the NGF-binding domain of TrkA through Phe327 and Asn355. Collectively, our findings provide evidence that SCH promotes neuronal development via upregulating TrkA-signaling proteins and suggest that SCH could be a promising therapeutic agent in the prevention and treatment of neurodegenerative disorders.
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Han F, Guan X, Guo W, Lu B. Therapeutic potential of a TrkB agonistic antibody for ischemic brain injury. Neurobiol Dis 2019; 127:570-581. [DOI: 10.1016/j.nbd.2019.04.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/04/2019] [Accepted: 04/10/2019] [Indexed: 12/20/2022] Open
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23
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Diamantopoulou E, Baxendale S, de la Vega de León A, Asad A, Holdsworth CJ, Abbas L, Gillet VJ, Wiggin GR, Whitfield TT. Identification of compounds that rescue otic and myelination defects in the zebrafish adgrg6 ( gpr126) mutant. eLife 2019; 8:44889. [PMID: 31180326 PMCID: PMC6598766 DOI: 10.7554/elife.44889] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 06/08/2019] [Indexed: 12/18/2022] Open
Abstract
Adgrg6 (Gpr126) is an adhesion class G protein-coupled receptor with a conserved role in myelination of the peripheral nervous system. In the zebrafish, mutation of adgrg6 also results in defects in the inner ear: otic tissue fails to down-regulate versican gene expression and morphogenesis is disrupted. We have designed a whole-animal screen that tests for rescue of both up- and down-regulated gene expression in mutant embryos, together with analysis of weak and strong alleles. From a screen of 3120 structurally diverse compounds, we have identified 68 that reduce versican b expression in the adgrg6 mutant ear, 41 of which also restore myelin basic protein gene expression in Schwann cells of mutant embryos. Nineteen compounds unable to rescue a strong adgrg6 allele provide candidates for molecules that may interact directly with the Adgrg6 receptor. Our pipeline provides a powerful approach for identifying compounds that modulate GPCR activity, with potential impact for future drug design.
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Affiliation(s)
- Elvira Diamantopoulou
- Bateson Centre and Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Sarah Baxendale
- Bateson Centre and Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | | | - Anzar Asad
- Bateson Centre and Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Celia J Holdsworth
- Bateson Centre and Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Leila Abbas
- Bateson Centre and Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Valerie J Gillet
- Information School, University of Sheffield, Sheffield, United Kingdom
| | | | - Tanya T Whitfield
- Bateson Centre and Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
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7,8-Dihydroxyflavone Protects Nigrostriatal Dopaminergic Neurons from Rotenone-Induced Neurotoxicity in Rodents. PARKINSONS DISEASE 2019; 2019:9193534. [PMID: 30944722 PMCID: PMC6421741 DOI: 10.1155/2019/9193534] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/11/2018] [Accepted: 01/23/2019] [Indexed: 12/13/2022]
Abstract
7,8-Dihydroxyflavone (7,8-DHF) is thought to be a promising therapeutic agent for various neurodegenerative diseases. The major purpose of this study was to investigate the neuroprotective effects of 7,8-DHF on the rotenone-induced motor deficit of Parkinson's disease. Nine-month-old rats were treated with rotenone (2 mg/kg/day, i.h.) for 5 weeks to establish the animal model of Parkinson's disease (PD), and 7,8-DHF (5 mg/kg, i.p.) was administrated daily throughout the whole period of rotenone injection. Five weeks later, an open field test was used to assess the motor ability of the animals. TH immunostaining was performed to evaluate rotenone-induced neurotoxicity on substantia nigra (SN) dopaminergic neurons and the DA terminals in the striatum. Western blot analyses were used to examine the expressions of TH, BDNF/TrkB signaling cascades, phospho-α-synuclein (Ser129), α-synuclein, and phospho-tau (Ser396) in SN. The results revealed that treatment with 7,8-DHF improved PD model's behavioral performance and reduced dopaminergic neuron loss in the SN and striatum, associated with the activation of TrkB receptors and its signaling cascades, and reduced p-MAPK, p-α-synuclein, and p-tau. Collectively, these results indicated that 7,8-DHF displayed prominent neuroprotective properties, providing a promising therapeutic strategy for PD treatment.
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25
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Naoi M, Shamoto-Nagai M, Maruyama W. Neuroprotection of multifunctional phytochemicals as novel therapeutic strategy for neurodegenerative disorders: antiapoptotic and antiamyloidogenic activities by modulation of cellular signal pathways. FUTURE NEUROLOGY 2019. [DOI: 10.2217/fnl-2018-0028] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In neurodegenerative disorders, including Alzheimer's and Parkinson's disease, neuroprotection by diet and natural bioactive compounds has been proposed to prevent the onset and progress of neurodegeneration by modification of pathogenic factors. Plant food-derived phytochemicals protect neurons via targeting oxidative stress, mitochondrial dysfunction, neurotrophic factor deficit, apoptosis and abnormal protein accumulation. This review presents the molecular mechanism of neuroprotection by phytochemicals: direct regulation of mitochondrial apoptotic machinery, modification of cellular signal pathways, induction of antiapoptotic Bcl-2 protein family and prosurvival neurotrophic factors, such as brain- and glial cell line-derived neurotrophic factor, and prevention of protein aggregation. Multitargeted neuroprotective agents are under development based on the structure of blood–brain barrier-permeable phytochemicals to ameliorate brain dysfunction and prevent neurodegeneration.
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Affiliation(s)
- Makoto Naoi
- Department of Health & Nutrition, Faculty of Psychological & Physical Science, Aichi Gakuin University, Nisshin, Aichi, Japan
| | - Masayo Shamoto-Nagai
- Department of Health & Nutrition, Faculty of Psychological & Physical Science, Aichi Gakuin University, Nisshin, Aichi, Japan
| | - Wakako Maruyama
- Department of Health & Nutrition, Faculty of Psychological & Physical Science, Aichi Gakuin University, Nisshin, Aichi, Japan
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26
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Levy MJF, Boulle F, Steinbusch HW, van den Hove DLA, Kenis G, Lanfumey L. Neurotrophic factors and neuroplasticity pathways in the pathophysiology and treatment of depression. Psychopharmacology (Berl) 2018; 235:2195-2220. [PMID: 29961124 PMCID: PMC6061771 DOI: 10.1007/s00213-018-4950-4] [Citation(s) in RCA: 163] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 06/18/2018] [Indexed: 02/06/2023]
Abstract
Depression is a major health problem with a high prevalence and a heavy socioeconomic burden in western societies. It is associated with atrophy and impaired functioning of cortico-limbic regions involved in mood and emotion regulation. It has been suggested that alterations in neurotrophins underlie impaired neuroplasticity, which may be causally related to the development and course of depression. Accordingly, mounting evidence suggests that antidepressant treatment may exert its beneficial effects by enhancing trophic signaling on neuronal and synaptic plasticity. However, current antidepressants still show a delayed onset of action, as well as lack of efficacy. Hence, a deeper understanding of the molecular and cellular mechanisms involved in the pathophysiology of depression, as well as in the action of antidepressants, might provide further insight to drive the development of novel fast-acting and more effective therapies. Here, we summarize the current literature on the involvement of neurotrophic factors in the pathophysiology and treatment of depression. Further, we advocate that future development of antidepressants should be based on the neurotrophin theory.
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Affiliation(s)
- Marion J F Levy
- Centre de Psychiatrie et Neurosciences (Inserm U894), Université Paris Descartes, 102-108 rue de la santé, 75014, Paris, France
- Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, The Netherlands
- EURON-European Graduate School of Neuroscience, Maastricht, The Netherlands
| | - Fabien Boulle
- Centre de Psychiatrie et Neurosciences (Inserm U894), Université Paris Descartes, 102-108 rue de la santé, 75014, Paris, France
- Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, The Netherlands
- EURON-European Graduate School of Neuroscience, Maastricht, The Netherlands
| | - Harry W Steinbusch
- Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, The Netherlands
- EURON-European Graduate School of Neuroscience, Maastricht, The Netherlands
| | - Daniël L A van den Hove
- Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, The Netherlands
- EURON-European Graduate School of Neuroscience, Maastricht, The Netherlands
- Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Wuerzburg, Germany
| | - Gunter Kenis
- Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, The Netherlands
- EURON-European Graduate School of Neuroscience, Maastricht, The Netherlands
| | - Laurence Lanfumey
- Centre de Psychiatrie et Neurosciences (Inserm U894), Université Paris Descartes, 102-108 rue de la santé, 75014, Paris, France.
- EURON-European Graduate School of Neuroscience, Maastricht, The Netherlands.
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27
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Simmons DA. Modulating Neurotrophin Receptor Signaling as a Therapeutic Strategy for Huntington's Disease. J Huntingtons Dis 2018; 6:303-325. [PMID: 29254102 PMCID: PMC5757655 DOI: 10.3233/jhd-170275] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Huntington’s disease (HD) is an autosomal dominant neurodegenerative disorder caused by CAG repeat expansions in the IT15 gene which encodes the huntingtin (HTT) protein. Currently, no treatments capable of preventing or slowing disease progression exist. Disease modifying therapeutics for HD would be expected to target a comprehensive set of degenerative processes given the diverse mechanisms contributing to HD pathogenesis including neuroinflammation, excitotoxicity, and transcription dysregulation. A major contributor to HD-related degeneration is mutant HTT-induced loss of neurotrophic support. Thus, neurotrophin (NT) receptors have emerged as therapeutic targets in HD. The considerable overlap between NT signaling networks and those dysregulated by mutant HTT provides strong theoretical support for this approach. This review will focus on the contributions of disrupted NT signaling in HD-related neurodegeneration and how targeting NT receptors to augment pro-survival signaling and/or to inhibit degenerative signaling may combat HD pathologies. Therapeutic strategies involving NT delivery, peptidomimetics, and the targeting of specific NT receptors (e.g., Trks or p75NTR), particularly with small molecule ligands, are discussed.
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Affiliation(s)
- Danielle A Simmons
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
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28
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Pluskal T, Weng JK. Natural product modulators of human sensations and mood: molecular mechanisms and therapeutic potential. Chem Soc Rev 2018; 47:1592-1637. [PMID: 28933478 DOI: 10.1039/c7cs00411g] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Humans perceive physical information about the surrounding environment through their senses. This physical information is registered by a collection of highly evolved and finely tuned molecular sensory receptors. A multitude of bioactive, structurally diverse ligands have evolved in nature that bind these molecular receptors. The complex, dynamic interactions between the ligands and the receptors lead to changes in our sensory perception or mood. Here, we review our current knowledge of natural products and their derived analogues that interact specifically with human G protein-coupled receptors, ion channels, and nuclear hormone receptors to modulate the sensations of taste, smell, temperature, pain, and itch, as well as mood and its associated behaviour. We discuss the molecular and structural mechanisms underlying such interactions and highlight cases where subtle differences in natural product chemistry produce drastic changes in functional outcome. We also discuss cases where a single compound triggers complex sensory or behavioural changes in humans through multiple mechanistic targets. Finally, we comment on the therapeutic potential of the reviewed area of research and draw attention to recent technological developments in genomics, metabolomics, and metabolic engineering that allow us to tap the medicinal properties of natural product chemistry without taxing nature.
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Affiliation(s)
- Tomáš Pluskal
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA.
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29
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Chitranshi N, Dheer Y, Abbasi M, You Y, Graham SL, Gupta V. Glaucoma Pathogenesis and Neurotrophins: Focus on the Molecular and Genetic Basis for Therapeutic Prospects. Curr Neuropharmacol 2018; 16:1018-1035. [PMID: 29676228 PMCID: PMC6120108 DOI: 10.2174/1570159x16666180419121247] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 04/10/2018] [Accepted: 04/18/2018] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Retinal ganglion cell (RGC) degeneration is a major feature of glaucoma pathology. Neuroprotective approaches that delay or halt the progression of RGC loss are needed to prevent vision loss which can occur even after conventional medical or surgical treatments to lower intraocular pressure. OBJECTIVE The aim of this review was to examine the progress in genetics and cellular mechanisms associated with endoplasmic reticulum (ER) stress, RGC dysfunction and cell death pathways in glaucoma. MATERIALS AND METHODS Here, we review the involvement of neurotrophins like brain derived neurotrophic factor (BDNF) and its high affinity receptor tropomyosin receptor kinase (TrkB) in glaucoma. The role of ER stress markers in human and animal retinas in health and disease conditions is also discussed. Further, we analysed the literature highlighting genetic linkage in the context of primary open angle glaucoma and suggested mechanistic insights into potential therapeutic options relevant to glaucoma management. RESULTS The literature review of the neurobiology underlying neurotrophin pathways, ER stress and gene associations provide critical insights into association of RGCs death in glaucoma. Alteration in signalling pathway is associated with increased risk of misfolded protein aggregation in ER promoting RGC apoptosis. Several genes that are linked with neurotrophin signalling pathways have been reported to be associated with glaucoma pathology. CONCLUSION Understanding genetic heterogeneity and involvement of neurotrophin biology in glaucoma could help to understand the complex pathophysiology of glaucoma. Identification of novel molecular targets will be critical for drug development and provide neuroprotection to the RGCs and optic nerve.
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Affiliation(s)
- Nitin Chitranshi
- Address correspondence to this author at the Faculty of Medicine and Health Sciences, 75, Talavera Road, Macquarie University, Sydney, NSW 2109, Australia; Tel: +61-298502760; E-mail:
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30
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Alshammari GM, Balakrishnan A, Chinnasamy T. Nimbolide attenuate the lipid accumulation, oxidative stress and antioxidant in primary hepatocytes. Mol Biol Rep 2017; 44:463-474. [PMID: 29185131 DOI: 10.1007/s11033-017-4132-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 11/17/2017] [Indexed: 02/07/2023]
Abstract
Nimbolide is a bioactive compound found in Azadirachta indica. This work was devised to investigate the potential effects of nimbolide on intracellular lipid deposition and its associated redox modulation in primary hepatocytes (Heps). Lipid accumulation was induced in Heps by supplementing 1 mM oleic acid for 24 h which was marked by significant accumulation of lipids. The results demonstrated that nimbolide can decrease intracellular cholesterol, free fatty acids and triglycerides. Nimbolide may also improve hepatocytes function through its antioxidant effects by inhibiting oxidative DNA damage and lipid peroxidation by curtailing the reactive oxygen species levels. Further it also restore the mitochondrial potential, improving the endogenous antioxidant levels such as GSH and antioxidant enzyme activities. Nimbolide increased (P < 0.05) liver X receptor-α (LXRα), peroxisome proliferator-activated receptor-γ (PPARγ) and sterol regulatory element-binding protein-1c (SREBP1c) gene expression in Heps. The biological significance of nimbolide may involve hypolipidemic effect, lipid peroxidation inhibition, DNA damage inhibition, ROS inhibition, restoring mitochondrial function, increases in GSH and SOD & CAT activities, and direct regulation of LXRα, PPARγ and SREBP1c gene expression. Nimbolide may be used as effective lipid lowering compound and lipid deposition-induced Heps changes.
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Affiliation(s)
- Ghedeir M Alshammari
- Department of Food Science and Nutrition, College of Food and Agricultural Science, King Saud University, P.O. Box 2460, Riyadh, 11451, Saudi Arabia.
| | - Aristatile Balakrishnan
- Department of Food Science and Nutrition, College of Food and Agricultural Science, King Saud University, P.O. Box 2460, Riyadh, 11451, Saudi Arabia
| | - Thirunavukkarasu Chinnasamy
- Department of Food Science and Nutrition, College of Food and Agricultural Science, King Saud University, P.O. Box 2460, Riyadh, 11451, Saudi Arabia.
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31
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Boltaev U, Meyer Y, Tolibzoda F, Jacques T, Gassaway M, Xu Q, Wagner F, Zhang YL, Palmer M, Holson E, Sames D. Multiplex quantitative assays indicate a need for reevaluating reported small-molecule TrkB agonists. Sci Signal 2017; 10:10/493/eaal1670. [PMID: 28831019 DOI: 10.1126/scisignal.aal1670] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin-related kinase B (TrkB), have emerged as key regulators of brain plasticity and represent disease-modifying targets for several brain disorders, including Alzheimer's disease and major depressive disorder. Because of poor pharmacokinetic properties of BDNF, the interest in small-molecule TrkB agonists and modulators is high. Several compounds have been reported to act as TrkB agonists, and their increasing use in various nervous system disorder models creates the perception that these are reliable probes. To examine key pharmacological parameters of these compounds in detail, we have developed and optimized a series of complementary quantitative assays that measure TrkB receptor activation, TrkB-dependent downstream signaling, and gene expression in different cellular contexts. Although BDNF and other neurotrophic factors elicited robust and dose-dependent receptor activation and downstream signaling, we were unable to reproduce these activities using the reported small-molecule TrkB agonists. Our findings indicate that experimental results obtained with these compounds must be carefully interpreted and highlight the challenge of developing reliable pharmacological activators of this key molecular target.
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Affiliation(s)
- Umed Boltaev
- Department of Chemistry, Columbia University, New York, NY 10027, USA.,NeuroTechnology Center at Columbia University, New York, NY 10027, USA
| | - Yves Meyer
- Department of Chemistry, Columbia University, New York, NY 10027, USA
| | - Farangis Tolibzoda
- Department of Chemistry, Columbia University, New York, NY 10027, USA.,NeuroTechnology Center at Columbia University, New York, NY 10027, USA
| | - Teresa Jacques
- Department of Chemistry, Columbia University, New York, NY 10027, USA
| | - Madalee Gassaway
- Department of Chemistry, Columbia University, New York, NY 10027, USA.,NeuroTechnology Center at Columbia University, New York, NY 10027, USA
| | - Qihong Xu
- Stanley Center for Psychiatric Research, Broad Institute of Massachusetts Institute of Technology and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA
| | - Florence Wagner
- Stanley Center for Psychiatric Research, Broad Institute of Massachusetts Institute of Technology and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA
| | - Yan-Ling Zhang
- Stanley Center for Psychiatric Research, Broad Institute of Massachusetts Institute of Technology and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA
| | - Michelle Palmer
- Stanley Center for Psychiatric Research, Broad Institute of Massachusetts Institute of Technology and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA
| | - Edward Holson
- Stanley Center for Psychiatric Research, Broad Institute of Massachusetts Institute of Technology and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA
| | - Dalibor Sames
- Department of Chemistry, Columbia University, New York, NY 10027, USA. .,NeuroTechnology Center at Columbia University, New York, NY 10027, USA
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32
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Kramer B, Tropitzsch A, Müller M, Löwenheim H. Myelin-induced inhibition in a spiral ganglion organ culture - Approaching a natural environment in vitro. Neuroscience 2017; 357:75-83. [PMID: 28596120 DOI: 10.1016/j.neuroscience.2017.05.053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 05/12/2017] [Accepted: 05/30/2017] [Indexed: 12/23/2022]
Abstract
The performance of a cochlear implant depends on the defined interaction between afferent neurons of the spiral ganglion and the inserted electrode. Neurite outgrowth can be induced by neurotrophins such as brain-derived neurotrophic factor (BDNF) via tropomyosin kinase receptor B (TrkB). However, neurotrophin signaling through the p75 neurotrophin receptor (p75) inhibits neurite outgrowth in the presence of myelin. Organotypic cultures derived from postnatal (P3-5) mice were used to study myelin-induced inhibition in the cochlear spiral ganglion. Neurite outgrowth was analyzed and quantified utilizing an adapted Sholl analysis. Stimulation of neurite outgrowth was quantified after application of BDNF, the selective TrkB agonist 7,8-dihydroxyflavone (7,8-DHF) and a selective inhibitor of the Rho-associated kinase (Y27632), which inhibits the p75 pathway. Myelin-induced inhibition was assessed by application of myelin-associated glycoprotein (MAG-Fc) to stimulate the inhibitory p75 pathway. Inhibition of neurite outgrowth was achieved by the selective TrkB inhibitor K252a. Stimulation of neurite outgrowth was observed after treatment with BDNF, 7,8 DHF and a combination of BDNF and Y27632. The 7,8-DHF-induced growth effects could be inhibited by K252a. Furthermore, inhibition of neurite outgrowth was observed after supplementation with MAG-Fc. Myelin-induced inhibition could be overcome by 7,8-DHF and the combination of BDNF and Y27632. In this study, myelin-induced inhibition of neurite outgrowth was established in a spiral ganglion model. We reveal that 7,8-DHF is a viable novel compound for the stimulation of neurite outgrowth in a myelin-induced inhibitory environment. The combination of TrkB stimulation and ROCK inhibition can be used to overcome myelin inhibition.
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Affiliation(s)
- Benedikt Kramer
- Department of Otorhinolaryngology - Head and Neck Surgery, Hearing Research Centre Tübingen (THRC), University Tübingen, Germany
| | - Anke Tropitzsch
- Department of Otorhinolaryngology - Head and Neck Surgery, Hearing Research Centre Tübingen (THRC), University Tübingen, Germany
| | - Marcus Müller
- Department of Otorhinolaryngology - Head and Neck Surgery, Hearing Research Centre Tübingen (THRC), University Tübingen, Germany.
| | - Hubert Löwenheim
- Department of Otorhinolaryngology - Head and Neck Surgery, Hearing Research Centre Tübingen (THRC), University Tübingen, Germany
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33
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Zhao H, Alam A, San CY, Eguchi S, Chen Q, Lian Q, Ma D. Molecular mechanisms of brain-derived neurotrophic factor in neuro-protection: Recent developments. Brain Res 2017; 1665:1-21. [PMID: 28396009 DOI: 10.1016/j.brainres.2017.03.029] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 03/02/2017] [Accepted: 03/28/2017] [Indexed: 12/13/2022]
Abstract
Neuronal cell injury, as a consequence of acute or chronic neurological trauma, is a significant cause of mortality around the world. On a molecular level, the condition is characterized by widespread cell death and poor regeneration, which can result in severe morbidity in survivors. Potential therapeutics are of major interest, with a promising candidate being brain-derived neurotrophic factor (BDNF), a ubiquitous agent in the brain which has been associated with neural development and may facilitate protective and regenerative effects following injury. This review summarizes the available information on the potential benefits of BDNF and the molecular mechanisms involved in several pathological conditions, including hypoxic brain injury, stroke, Alzheimer's disease and Parkinson's disease. It further explores the methods in which BDNF can be applied in clinical and therapeutic settings, and the potential challenges to overcome.
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Affiliation(s)
- Hailin Zhao
- Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK
| | - Azeem Alam
- Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK
| | - Chun-Yin San
- Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK
| | - Shiori Eguchi
- Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK
| | - Qian Chen
- Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK; Department of Anaesthesiology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Qingquan Lian
- Department of Anesthesiology, Second Affiliated Hospital, Wenzhou Medical University, Wenzhou, China.
| | - Daqing Ma
- Anaesthetics, Pain Medicine and Intensive Care, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Chelsea & Westminster Hospital, London, UK.
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Schuppe AW, Newhouse TR. Assembly of the Limonoid Architecture by a Divergent Approach: Total Synthesis of (±)-Andirolide N via (±)-8α-Hydroxycarapin. J Am Chem Soc 2017; 139:631-634. [PMID: 28001380 PMCID: PMC5928519 DOI: 10.1021/jacs.6b12268] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We report the first total synthesis of the limonoid andirolide N using a 12-step sequence from commercially available materials. The final step of this route demonstrates the chemical feasibility of our biosynthetic proposal that andirolide N arises from 8α-hydroxycarapin. The strategic use of a degraded limonoid as a platform for the synthesis of more structurally complex congeners may be a general approach to obtain limonoids with diverse functional properties.
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Affiliation(s)
- Alexander W. Schuppe
- Department of Chemistry, Yale University, 275 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Timothy R. Newhouse
- Department of Chemistry, Yale University, 275 Prospect Street, New Haven, Connecticut 06520-8107, United States
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35
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Janssens J, Lu D, Ni B, Chadwick W, Siddiqui S, Azmi A, Etienne H, Jushaj A, van Gastel J, Martin B, Maudsley S. Development of Precision Small-Molecule Proneurotrophic Therapies for Neurodegenerative Diseases. VITAMINS AND HORMONES 2016; 104:263-311. [PMID: 28215298 DOI: 10.1016/bs.vh.2016.10.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Age-related neurodegenerative diseases, such as Alzheimer's disease, will represent one of the largest future burdens on worldwide healthcare systems due to the increasing proportion of elderly in our society. As deficiencies in neurotrophins are implicated in the pathogenesis of many age-related neurodegenerative disorders, it is reasonable to consider that global neurotrophin resistance may also become a major healthcare threat. Central nervous system networks are effectively maintained through aging by neuroprotective and neuroplasticity signaling mechanisms which are predominantly controlled by neurotrophin receptor signaling. Neurotrophin receptors are single pass receptor tyrosine kinases that form dimeric structures upon ligand binding to initiate cellular signaling events that control many protective and plasticity-related pathways. Declining functionality of the neurotrophin ligand-receptor system is considered one of the hallmarks of neuropathological aging. Therefore, it is imperative to develop effective therapeutic strategies to contend with this significant issue. While the therapeutic applications of cognate ligands for neurotrophin receptors are limited, the development of nonpeptidergic, small-molecule ligands can overcome these limitations, and productively regulate this important receptor system with beneficial effects. Using our advanced knowledge of the high-dimensionality complexity of receptor systems, the future generation of precision medicines targeting these systems will be an attainable goal.
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Affiliation(s)
- J Janssens
- Translational Neurobiology Group, University of Antwerp, Antwerpen, Belgium
| | - D Lu
- Receptor Pharmacology Unit, National Institute on Aging, National Institutes of Health, Baltimore MD United States
| | - B Ni
- Receptor Pharmacology Unit, National Institute on Aging, National Institutes of Health, Baltimore MD United States
| | - W Chadwick
- Receptor Pharmacology Unit, National Institute on Aging, National Institutes of Health, Baltimore MD United States
| | - S Siddiqui
- Receptor Pharmacology Unit, National Institute on Aging, National Institutes of Health, Baltimore MD United States
| | - A Azmi
- Translational Neurobiology Group, University of Antwerp, Antwerpen, Belgium
| | - H Etienne
- Translational Neurobiology Group, University of Antwerp, Antwerpen, Belgium
| | - A Jushaj
- Translational Neurobiology Group, University of Antwerp, Antwerpen, Belgium
| | - J van Gastel
- Translational Neurobiology Group, University of Antwerp, Antwerpen, Belgium
| | - B Martin
- Metabolism Unit, National Institute on Aging, National Institutes of Health, Baltimore MD United States
| | - S Maudsley
- Translational Neurobiology Group, University of Antwerp, Antwerpen, Belgium; Receptor Pharmacology Unit, National Institute on Aging, National Institutes of Health, Baltimore MD United States.
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36
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Neuroprotective Effects of 7, 8-dihydroxyflavone on Midbrain Dopaminergic Neurons in MPP +-treated Monkeys. Sci Rep 2016; 6:34339. [PMID: 27731318 PMCID: PMC5059638 DOI: 10.1038/srep34339] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/25/2016] [Indexed: 12/12/2022] Open
Abstract
Parkinson’s disease (PD) is one common neurodegenerative disease caused by a significant loss of midbrain dopaminergic neurons. Previous reports showed that 7, 8- dihydroxyflavone (7, 8-DHF) as a potent TrkB agonist can mimic BDNF and play neuroprotective roles for mouse dopaminergic neurons. Nonetheless, the safety and neuroprotective effects are unclear in monkey models of PD. Here, we find that 7, 8-DHF could be absorbed and metabolized into 7-hydroxy-8-methoxyflavone through oral administration in monkeys. The half-life time of 7, 8-DHF in monkey plasma is about 4–8 hrs. Furthermore, these monkeys maintain health state throughout the course of seven-month treatments of 7, 8-DHF (30 mg/kg/day). Importantly, 7, 8-DHF treatments can prevent the progressive degeneration of midbrain dopaminergic neurons by attenuating neurotoxic effects of MPP+ and display strong neuroprotective effects in monkeys. Our study demonstrates that this promising small molecule may be transited into a clinical useful pharmacological agent.
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37
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Josephy-Hernandez S, Jmaeff S, Pirvulescu I, Aboulkassim T, Saragovi HU. Neurotrophin receptor agonists and antagonists as therapeutic agents: An evolving paradigm. Neurobiol Dis 2016; 97:139-155. [PMID: 27546056 DOI: 10.1016/j.nbd.2016.08.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 08/10/2016] [Accepted: 08/16/2016] [Indexed: 12/12/2022] Open
Abstract
Neurodegenerative disorders are prevalent, complex and devastating conditions, with very limited treatment options currently available. While they manifest in many forms, there are commonalities that link them together. In this review, we will focus on neurotrophins - a family of related factors involved in neuronal development and maintenance. Neurodegenerative diseases often present with a neurotrophin imbalance, in which there may be decreases in trophic signaling through Trk receptors for example, and/or increases in pro-apoptotic activity through p75. Clinical trials with neurotrophins have continuously failed due to their poor pharmacological properties as well as the unavoidable activation of p75. Thus, there is a need for drugs without such setbacks. Small molecule neurotrophin mimetics are favorable options since they can selectively activate Trks or inactivate p75. In this review, we will initially present a brief outline of how these molecules are synthesized and their mechanisms of action; followed by an update in the current state of neurotrophins and small molecules in major neurodegenerative diseases. Although there has been significant progress in the development of potential therapeutics, more studies are needed to establish clear mechanisms of action and target specificity in order to transition from animal models to the assessment of safety and use in humans.
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Affiliation(s)
- Sylvia Josephy-Hernandez
- Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec, Canada; Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
| | - Sean Jmaeff
- Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec, Canada; Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Iulia Pirvulescu
- Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec, Canada; Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Tahar Aboulkassim
- Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec, Canada
| | - H Uri Saragovi
- Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec, Canada; Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada; Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada.
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Kazim SF, Iqbal K. Neurotrophic factor small-molecule mimetics mediated neuroregeneration and synaptic repair: emerging therapeutic modality for Alzheimer's disease. Mol Neurodegener 2016; 11:50. [PMID: 27400746 PMCID: PMC4940708 DOI: 10.1186/s13024-016-0119-y] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Accepted: 07/02/2016] [Indexed: 11/10/2022] Open
Abstract
Alzheimer's disease (AD) is an incurable and debilitating chronic progressive neurodegenerative disorder which is the leading cause of dementia worldwide. AD is a heterogeneous and multifactorial disorder, histopathologically characterized by the presence of amyloid β (Aβ) plaques and neurofibrillary tangles composed of Aβ peptides and abnormally hyperphosphorylated tau protein, respectively. Independent of the various etiopathogenic mechanisms, neurodegeneration is a final common outcome of AD neuropathology. Synaptic loss is a better correlate of cognitive impairment in AD than Aβ or tau pathologies. Thus a highly promising therapeutic strategy for AD is to shift the balance from neurodegeneration to neuroregeneration and synaptic repair. Neurotrophic factors, by virtue of their neurogenic and neurotrophic activities, have potential for the treatment of AD. However, the clinical therapeutic usage of recombinant neurotrophic factors is limited because of the insurmountable hurdles of unfavorable pharmacokinetic properties, poor blood-brain barrier (BBB) permeability, and severe adverse effects. Neurotrophic factor small-molecule mimetics, in this context, represent a potential strategy to overcome these short comings, and have shown promise in preclinical studies. Neurotrophic factor small-molecule mimetics have been the focus of intense research in recent years for AD drug development. Here, we review the relevant literature regarding the therapeutic beneficial effect of neurotrophic factors in AD, and then discuss the recent status of research regarding the neurotrophic factor small-molecule mimetics as therapeutic candidates for AD. Lastly, we summarize the preclinical studies with a ciliary neurotrophic factor (CNTF) small-molecule peptide mimetic, Peptide 021 (P021). P021 is a neurogenic and neurotrophic compound which enhances dentate gyrus neurogenesis and memory processes via inhibiting leukemia inhibitory factor (LIF) signaling pathway and increasing brain-derived neurotrophic factor (BDNF) expression. It robustly inhibits tau abnormal hyperphosphorylation via increased BDNF mediated decrease in glycogen synthase kinase-3β (GSK-3β, major tau kinase) activity. P021 is a small molecular weight, BBB permeable compound with suitable pharmacokinetics for oral administration, and without adverse effects associated with native CNTF or BDNF molecule. P021 has shown beneficial therapeutic effect in several preclinical studies and has emerged as a highly promising compound for AD drug development.
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Affiliation(s)
- Syed Faraz Kazim
- />Department of Neurochemistry, and SUNY Downstate/NYSIBR Program in Developmental Neuroscience, New York State Institute for Basic Research (NYSIBR), 1050 Forest Hill Road, Staten Island, NY 10314 USA
- />Graduate Program in Neural and Behavioral Science, and Department of Physiology and Pharmacology, State University of New York (SUNY) Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203 USA
| | - Khalid Iqbal
- />Department of Neurochemistry, and SUNY Downstate/NYSIBR Program in Developmental Neuroscience, New York State Institute for Basic Research (NYSIBR), 1050 Forest Hill Road, Staten Island, NY 10314 USA
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Fukuda M, Takatori A, Nakamura Y, Suganami A, Hoshino T, Tamura Y, Nakagawara A. Effects of novel small compounds targeting TrkB on neuronal cell survival and depression-like behavior. Neurochem Int 2016; 97:42-8. [DOI: 10.1016/j.neuint.2016.04.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 04/14/2016] [Accepted: 04/28/2016] [Indexed: 11/25/2022]
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40
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Yang T, Massa SM, Tran KC, Simmons DA, Rajadas J, Zeng AY, Jang T, Carsanaro S, Longo FM. A small molecule TrkB/TrkC neurotrophin receptor co-activator with distinctive effects on neuronal survival and process outgrowth. Neuropharmacology 2016; 110:343-361. [PMID: 27334657 DOI: 10.1016/j.neuropharm.2016.06.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 05/28/2016] [Accepted: 06/16/2016] [Indexed: 01/16/2023]
Abstract
Neurotrophin (NT) receptors are coupled to numerous signaling networks that play critical roles in neuronal survival and plasticity. Several non-peptide small molecule ligands have recently been reported that bind to and activate specific tropomyosin-receptor kinase (Trk) NT receptors, stimulate their downstream signaling, and cause biologic effects similar to, though not completely overlapping, those of the native NT ligands. Here, in silico screening, coupled with low-throughput neuronal survival screening, identified a compound, LM22B-10, that, unlike prior small molecule Trk ligands, binds to and activates TrkB as well as TrkC. LM22B-10 increased cell survival and strongly accelerated neurite outgrowth, superseding the effects of brain-derived neurotrophic factor (BDNF), NT-3 or the two combined. Additionally, unlike the NTs, LM22B-10 supported substantial early neurite outgrowth in the presence of inhibiting glycoproteins. Examination of the mechanisms of these actions suggested contributions of the activation of both Trks and differential interactions with p75(NTR), as well as a requirement for involvement of the Trk extracellular domain. In aged mice, LM22B-10 activated hippocampal and striatal TrkB and TrkC, and their downstream signaling, and increased hippocampal dendritic spine density. Thus, LM22B-10 may constitute a new tool for the study of TrkB and TrkC signaling and their interactions with p75(NTR), and provides groundwork for the development of ligands that stimulate unique combinations of Trk receptors and activity patterns for application to selected neuronal populations and deficits present in various disease states.
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Affiliation(s)
- Tao Yang
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Stephen M Massa
- Department of Neurology and Laboratory for Computational Neurochemistry and Drug Discovery, San Francisco Veterans Affairs Medical Center, and Dept. of Neurology, University of California, San Francisco, CA 94121, USA.
| | - Kevin C Tran
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Danielle A Simmons
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jayakumar Rajadas
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Anne Y Zeng
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Taichang Jang
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sara Carsanaro
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Frank M Longo
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.
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Novel chemical library screen identifies naturally occurring plant products that specifically disrupt glioblastoma-endothelial cell interactions. Oncotarget 2016; 6:18282-92. [PMID: 26286961 PMCID: PMC4621891 DOI: 10.18632/oncotarget.4957] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 07/09/2015] [Indexed: 12/23/2022] Open
Abstract
Tumor growth is not solely a consequence of autonomous tumor cell properties. Rather, tumor cells act upon and are acted upon by their microenvironment. It is tumor tissue biology that ultimately determines tumor growth. Thus, we developed a compound library screen for agents that could block essential tumor-promoting effects of the glioblastoma (GBM) perivascular stem cell niche (PVN). We modeled the PVN with three-dimensional primary cultures of human brain microvascular endothelial cells in Matrigel. We previously demonstrated stimulated growth of GBM cells in this PVN model and used this to assay PVN function. We screened the Microsource Spectrum Collection library for drugs that specifically blocked PVN function, without any direct effect on GBM cells themselves. Three candidate PVN-disrupting agents, Iridin, Tigogenin and Triacetylresveratrol (TAR), were identified and evaluated in secondary in vitro screens against a panel of primary GBM isolates as well as in two different in vivo intracranial models. Iridin and TAR significantly inhibited intracranial tumor growth and prolonged survival in these mouse models. Together these data identify Iridin and TAR as drugs with novel GBM tissue disrupting effects and validate the importance of preclinical screens designed to address tumor tissue function rather than the mechanisms of autonomous tumor cell growth.
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Hayashi H, Takagi N. Endogenous Neuroprotective Molecules and Their Mechanisms in the Central Nervous System. Biol Pharm Bull 2016; 38:1104-8. [PMID: 26235573 DOI: 10.1248/bpb.b15-00361] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Functions of the central nervous system (CNS) are based on a complex neural network. It is believed that the CNS has several neuroprotective mechanisms operated by neurons, glia and other types of cells against various types of neuronal damage. Since mature, differentiated neurons are not able to divide, it is important to protect neurons from damage prior to death. The neuroprotective effects of a number of pharmaceutical agents and natural products against necrosis and apoptosis of the CNS neurons have been reported, thus this review will mainly discuss several endogenous neuroprotectants and their mechanisms.
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Affiliation(s)
- Hideki Hayashi
- Department of Applied Biochemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
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43
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Nie S, Xu Y, Chen G, Ma K, Han C, Guo Z, Zhang Z, Ye K, Cao X. Small molecule TrkB agonist deoxygedunin protects nigrostriatal dopaminergic neurons from 6-OHDA and MPTP induced neurotoxicity in rodents. Neuropharmacology 2015; 99:448-58. [DOI: 10.1016/j.neuropharm.2015.08.016] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 08/10/2015] [Accepted: 08/11/2015] [Indexed: 11/17/2022]
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Tyagi P, Kashyap M, Hensley H, Yoshimura N. Advances in intravesical therapy for urinary tract disorders. Expert Opin Drug Deliv 2015; 13:71-84. [PMID: 26479968 DOI: 10.1517/17425247.2016.1100166] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Intravesical therapy is a valuable option in the clinical management of urinary tract disorders such as interstitial cystitis/ painful bladder syndrome (IC/PBS) and refractory overactive bladder. This review will cover the latest advances in this field using polymer and liposomes as delivery platform for drugs, protein and nucleic acids. AREAS COVERED This review summarizes the significance of intravesical therapy for lower urinary tract disorders. The recent advancement of liposomes as a drug delivery platform for botulinum toxin, tacrolimus and small interfering RNA is discussed. The importance of polymers forming indwelling devices and hydrogels are also discussed, where all preparations improved efficacy parameters in rodent models. Clinical experience of treating IC/PBS with indwelling devices and liposomes are summarized and preclinical evidence about the downregulation of target gene expression in rodent bladder with liposomes complexed with siRNA is also reviewed. EXPERT OPINION There have been several advances in the field of intravesical therapy for improving clinical outcomes. One of the most promising research avenues is the repurposing of drugs, given previously by other routes of administration, such as tacrolimus. Intravesical therapy also opens up novel therapeutic targets with improved efficacy and safety for underactive bladder.
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Affiliation(s)
- Pradeep Tyagi
- a Department of Urology , University of Pittsburgh , Pittsburgh , PA 15213 , USA
| | - Mahendra Kashyap
- a Department of Urology , University of Pittsburgh , Pittsburgh , PA 15213 , USA
| | - Harvey Hensley
- b Small animal Imaging Facility , Fox chase cancer center , Philadelphia , PA 19111 , USA
| | - Naoki Yoshimura
- a Department of Urology , University of Pittsburgh , Pittsburgh , PA 15213 , USA
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Chapleau CA, Lane J, Pozzo-Miller L, Percy AK. Evaluation of current pharmacological treatment options in the management of Rett syndrome: from the present to future therapeutic alternatives. ACTA ACUST UNITED AC 2014; 8:358-69. [PMID: 24050745 DOI: 10.2174/15748847113086660069] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 02/14/2013] [Accepted: 02/21/2013] [Indexed: 11/22/2022]
Abstract
Neurodevelopmental disorders are a large family of conditions of genetic or environmental origin that are characterized by deficiencies in cognitive and behavioral functions. The therapeutic management of individuals with these disorders is typically complex and is limited to the treatment of specific symptoms that characterize each disorder. The neurodevelopmental disorder Rett syndrome (RTT) is the leading cause of severe intellectual disability in females. Mutations in the gene encoding the transcriptional regulator methyl-CpG-binding protein 2 (MECP2), located on the X chromosome, have been confirmed in more than 95% of individuals meeting diagnostic criteria for classical RTT. RTT is characterized by an uneventful early infancy followed by stagnation and regression of growth, motor, language, and social skills later in development. This review will discuss the genetics, pathology, and symptoms that distinguish RTT from other neurodevelopmental disorders associated with intellectual disability. Because great progress has been made in the basic and clinical science of RTT, the goal of this review is to provide a thorough assessment of current pharmacotherapeutic options to treat the symptoms associated with this disorder. Furthermore, we will highlight recent discoveries made with novel pharmacological interventions in experimental preclinical phases, and which have reversed pathological phenotypes in mouse and cell culture models of RTT and may result in clinical trials.
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Affiliation(s)
- Christopher A Chapleau
- Department of Pediatrics, CIRC-320, The University of Alabama at Birmingham, 1530 3rd Avenue South, Birmingham, AL 35294-0021, USA.
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46
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Burch P, Schmid F, Gademann K. Neuritogenic surfaces using natural product analogs. Adv Healthc Mater 2014; 3:1415-9. [PMID: 24596342 DOI: 10.1002/adhm.201300671] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 02/10/2014] [Indexed: 01/08/2023]
Abstract
Neuritogenic surfaces are generated by a simple dip-coating procedure, as glass slides are coated with a neurotrophin-like small organic molecule in the presence of a collagen matrix. The surfaces retain their biological activity for multiple cycles and the protocol is suitable for various substrates and coating conditions.
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Affiliation(s)
- Patrick Burch
- Department of Chemistry; University of Basel; St. Johanns-Ring 19 CH-4056 Basel Switzerland
| | - Fabian Schmid
- Department of Chemistry; University of Basel; St. Johanns-Ring 19 CH-4056 Basel Switzerland
| | - Karl Gademann
- Department of Chemistry; University of Basel; St. Johanns-Ring 19 CH-4056 Basel Switzerland
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47
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Liu X, Obianyo O, Chan CB, Huang J, Xue S, Yang JJ, Zeng F, Goodman M, Ye K. Biochemical and biophysical investigation of the brain-derived neurotrophic factor mimetic 7,8-dihydroxyflavone in the binding and activation of the TrkB receptor. J Biol Chem 2014; 289:27571-84. [PMID: 25143381 DOI: 10.1074/jbc.m114.562561] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
7,8-dihydroxyflavone (7,8-DHF), a newly identified small molecular TrkB receptor agonist, rapidly activates TrkB in both primary neurons and the rodent brain and mimics the physiological functions of the cognate ligand BDNF. Accumulating evidence supports that 7,8-DHF exerts neurotrophic effects in a TrkB-dependent manner. Nonetheless, the differences between 7,8-DHF and BDNF in activating TrkB remain incompletely understood. Here we show that 7,8-DHF and BDNF exhibit different TrkB activation kinetics in which TrkB maturation may be implicated. Employing two independent biophysical approaches, we confirm that 7,8-DHF interacts robustly with the TrkB extracellular domain, with a Kd of ∼10 nm. Although BDNF transiently activates TrkB, leading to receptor internalization and ubiquitination/degradation, in contrast, 7,8-DHF-triggered TrkB phosphorylation lasts for hours, and the internalized receptors are not degraded. Notably, primary neuronal maturation may be required for 7,8-DHF but not for BDNF to elicit the full spectrum of TrkB signaling cascades. Hence, 7,8-DHF interacts robustly with the TrkB receptor, and its agonistic effect may be mediated by neuronal development and maturation.
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Affiliation(s)
- Xia Liu
- From the Departments of Pathology and Laboratory Medicine and
| | | | - Chi Bun Chan
- From the Departments of Pathology and Laboratory Medicine and
| | - Junjian Huang
- From the Departments of Pathology and Laboratory Medicine and
| | - Shenghui Xue
- the Departments of Chemistry and Biology, Center for Diagnostics and Therapeutics (CDT), Georgia State University, Atlanta, Georgia 30303
| | - Jenny J Yang
- the Departments of Chemistry and Biology, Center for Diagnostics and Therapeutics (CDT), Georgia State University, Atlanta, Georgia 30303
| | - Fanxing Zeng
- Radiology and Imaging Sciences, Psychiatry, and Hematology and Oncology, Center for Systems Imaging, Wesley Woods Health Centers, Emory University School of Medicine, Atlanta, Georgia 30322 and
| | - Mark Goodman
- Radiology and Imaging Sciences, Psychiatry, and Hematology and Oncology, Center for Systems Imaging, Wesley Woods Health Centers, Emory University School of Medicine, Atlanta, Georgia 30322 and
| | - Keqiang Ye
- From the Departments of Pathology and Laboratory Medicine and
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48
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BDNF-TrkB receptor regulation of distributed adult neural plasticity, memory formation, and psychiatric disorders. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 122:169-92. [PMID: 24484701 DOI: 10.1016/b978-0-12-420170-5.00006-4] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) and its single transmembrane receptor, tropomysin-related kinase B (TrkB), are essential for adult synaptic plasticity and the formation of memories. However, there are regional and task-dependent differences underlying differential mechanisms of BDNF-TrkB function in the formation of these memories. Additionally, the BDNF pathway has been implicated in several psychiatric disorders including posttraumatic stress disorder, phobia, and panic disorder. Gaining a better understanding of this pathway and the neurobiology of memory through fundamental research may be helpful to identify effective prevention and treatment approaches both for diseases of memory deficit as well as in cases of enhanced aversive memory, such as in anxiety disorders.
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49
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Pimenta AC, Dourado DFAR, Martins JM, Melo A, Dias Soeiro Cordeiro MN, Almeida RD, Morra G, Moreira IS. Dynamic Structure of NGF and proNGF Complexed with p75NTR: Pro-Peptide Effect. J Chem Inf Model 2014; 54:2051-67. [DOI: 10.1021/ci500101n] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- A. C. Pimenta
- REQUIMTE
Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - D. F. A. R. Dourado
- Department
of Cell and Molecular Biology, Computational and Systems Biology, Uppsala Biomedicinska Centrum BMC, Box 596 751 24, Uppsala, Sweden
| | - J. M. Martins
- REQUIMTE
Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - A. Melo
- REQUIMTE
Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - M. N. Dias Soeiro Cordeiro
- REQUIMTE
Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - R. D. Almeida
- CNC-Center
for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - G. Morra
- Istituto di Chimica
del Riconoscimento Molecolare, CNR, 20131 Milano, Milano, Italy
| | - I. S. Moreira
- REQUIMTE
Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
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50
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Richner M, Ulrichsen M, Elmegaard SL, Dieu R, Pallesen LT, Vaegter CB. Peripheral nerve injury modulates neurotrophin signaling in the peripheral and central nervous system. Mol Neurobiol 2014; 50:945-70. [PMID: 24752592 DOI: 10.1007/s12035-014-8706-9] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 04/01/2014] [Indexed: 12/21/2022]
Abstract
Peripheral nerve injury disrupts the normal functions of sensory and motor neurons by damaging the integrity of axons and Schwann cells. In contrast to the central nervous system, the peripheral nervous system possesses a considerable capacity for regrowth, but regeneration is far from complete and functional recovery rarely returns to pre-injury levels. During development, the peripheral nervous system strongly depends upon trophic stimulation for neuronal differentiation, growth and maturation. The perhaps most important group of trophic substances in this context is the neurotrophins (NGF, BDNF, NT-3 and NT-4/5), which signal in a complex spatial and timely manner via the two structurally unrelated p75(NTR) and tropomyosin receptor kinase (TrkA, Trk-B and Trk-C) receptors. Damage to the adult peripheral nerves induces cellular mechanisms resembling those active during development, resulting in a rapid and robust increase in the synthesis of neurotrophins in neurons and Schwann cells, guiding and supporting regeneration. Furthermore, the injury induces neurotrophin-mediated changes in the dorsal root ganglia and in the spinal cord, which affect the modulation of afferent sensory signaling and eventually may contribute to the development of neuropathic pain. The focus of this review is on the expression patterns of neurotrophins and their receptors in neurons and glial cells of the peripheral nervous system and the spinal cord. Furthermore, injury-induced changes of expression patterns and the functional consequences in relation to axonal growth and remyelination as well as to neuropathic pain development will be reviewed.
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Affiliation(s)
- Mette Richner
- Danish Research Institute of Translational Neuroscience DANDRITE, Nordic EMBL Partnership, and Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Ole Worms Allé 3, 8000, Aarhus C, Denmark
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