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Eckl R, Fischer S, Sonnleitner CM, Schmidhuber D, Rehbein J, Reiser O. Stereoselective Synthesis of Biologically Relevant Tetrahydropyridines and Dihydro-2 H-pyrans via Ring-Expansion of Monocyclopropanated Heterocycles. ACS ORGANIC & INORGANIC AU 2021; 2:169-174. [PMID: 36855453 PMCID: PMC9954292 DOI: 10.1021/acsorginorgau.1c00042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A stereoselective, scalable, and metal-free ring-expansion of monocyclopropanated pyrroles and furans has been developed, leading to value-added highly functionalized tetrahydropyridine and dihydro-2H-pyran derivatives. Featuring a cyclopropylcarbinyl cation rearrangement as the key step, the selective cleavage of the unactivated endocyclic cyclopropane C-C bond is achieved. Targeted transformations of the thus obtained six-membered heterocycles give access to versatile building blocks with relevance for drug synthesis.
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Dhakal S, He L, Lyuboslavsky P, Sidhu C, Chrenek MA, Sellers JT, Boatright JH, Geisert EE, Setterholm NA, McDonald FE, Iuvone PM. A Tropomycin-Related Kinase B Receptor Activator for the Management of Ocular Blast-Induced Vision Loss. J Neurotrauma 2021; 38:2896-2906. [PMID: 34353120 PMCID: PMC8820286 DOI: 10.1089/neu.2020.7392] [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] [Indexed: 11/12/2022] Open
Abstract
Pressure waves from explosions or other traumatic events can damage the neurons of the eye and visual centers of the brain, leading to functional loss of vision. There are currently few treatments for such injuries that can be deployed rapidly to mitigate damage. Brain-derived neurotrophic factor (BDNF) and activation of its receptor tropomycin-related kinase B (TrkB) have neuroprotective effects in a number of degeneration models. Small molecule activators of TrkB, such as N-[2-(5-hydroxy-1H-indol-3-yl)ethyl]-2-oxopiperidine-3-carboxamide (HIOC), cross the blood-brain and blood-retina barriers after systemic administration. We characterize the effects of blast-induced ocular trauma on retinal and visual function. We show that systemic administration of HIOC, a potent small molecule activator of the BDNF/TrkB receptor, preserves visual function in mice exposed to ocular blast injury. The HIOC treatment for one week preserves visual function for at least four months. The HIOC treatment effectively protected vision when the initial dose was administered up to 3 h after blast, but not if the initial treatment was delayed for 24 h. We provide evidence that the therapeutic effect of HIOC is mediated by activation of BDNF/TrkB receptors. The results indicate that HIOC may be useful for managing ocular blast injury and other forms of traumatic optic neuropathy.
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Affiliation(s)
- Susov Dhakal
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | - Li He
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | | | - Curran Sidhu
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | - Micah A. Chrenek
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | - Jana T. Sellers
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | | | - Eldon E. Geisert
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | | | | | - P. Michael Iuvone
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, Georgia, USA
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Wurzer N, Klimczak U, Babl T, Fischer S, Angnes RA, Kreutzer D, Pattanaik A, Rehbein J, Reiser O. Heck-Type Coupling of Fused Bicyclic Vinylcyclopropanes: Synthesis of 1,2-Dihydropyridines, 2,3-Dihydro-1 H-azepines, 1,4-Cyclohexadienes, and 2 H-Pyrans. ACS Catal 2021. [DOI: 10.1021/acscatal.1c02564] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Nikolai Wurzer
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Urszula Klimczak
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Tobias Babl
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Sebastian Fischer
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Ricardo A. Angnes
- Institute of Chemistry, University of Campinas, Rua Carlos Gomes, 241, Cidade Universitária, Campinas, 13083-970 São Paulo, Brazil
| | - Dominik Kreutzer
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Aryaman Pattanaik
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Julia Rehbein
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Oliver Reiser
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
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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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