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Körner J, Albani S, Sudha Bhagavath Eswaran V, Roehl AB, Rossetti G, Lampert A. Sodium Channels and Local Anesthetics-Old Friends With New Perspectives. Front Pharmacol 2022; 13:837088. [PMID: 35418860 PMCID: PMC8996304 DOI: 10.3389/fphar.2022.837088] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 02/16/2022] [Indexed: 12/11/2022] Open
Abstract
The long history of local anesthetics (LAs) starts out in the late 19th century when the content of coca plant leaves was discovered to alleviate pain. Soon after, cocaine was established and headed off to an infamous career as a substance causing addiction. Today, LAs and related substances-in modified form-are indispensable in our clinical everyday life for pain relief during and after minor and major surgery, and dental practices. In this review, we elucidate on the interaction of modern LAs with their main target, the voltage-gated sodium channel (Navs), in the light of the recently published channel structures. Knowledge of the 3D interaction sites of the drug with the protein will allow to mechanistically substantiate the comprehensive data available on LA gating modification. In the 1970s it was suggested that LAs can enter the channel pore from the lipid phase, which was quite prospective at that time. Today we know from cryo-electron microscopy structures and mutagenesis experiments, that indeed Navs have side fenestrations facing the membrane, which are likely the entrance for LAs to induce tonic block. In this review, we will focus on the effects of LA binding on fast inactivation and use-dependent inhibition in the light of the proposed new allosteric mechanism of fast inactivation. We will elaborate on subtype and species specificity and provide insights into modelling approaches that will help identify the exact molecular binding orientation, access pathways and pharmacokinetics. With this comprehensive overview, we will provide new perspectives in the use of the drug, both clinically and as a tool for basic ion channel research.
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Affiliation(s)
- Jannis Körner
- Institute of Physiology, Aachen, Germany.,Clinic of Anesthesiology, Medical Faculty, Uniklinik RWTH Aachen, Aachen, Germany
| | - Simone Albani
- Institute for Neuroscience and Medicine (INM-9/IAS-5), Forschungszentrum Jülich, Jülich, Germany.,Faculty of Mathematics, Computer Science and Natural Sciences, RWTH Aachen, Aachen, Germany
| | | | - Anna B Roehl
- Clinic of Anesthesiology, Medical Faculty, Uniklinik RWTH Aachen, Aachen, Germany
| | - Giulia Rossetti
- Institute for Neuroscience and Medicine (INM-9/IAS-5), Forschungszentrum Jülich, Jülich, Germany.,Jülich Supercomputing Center (JSC), Forschungszentrum Jülich, Aachen, Germany.,Department of Neurology, University Hospital Aachen, RWTH Aachen University, Aachen, Germany
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Le Cann K, Meents JE, Sudha Bhagavath Eswaran V, Dohrn MF, Bott R, Maier A, Bialer M, Hautvast P, Erickson A, Rolke R, Rothermel M, Körner J, Kurth I, Lampert A. Assessing the impact of pain-linked Nav1.7 variants: An example of two variants with no biophysical effect. Channels (Austin) 2021; 15:208-228. [PMID: 33487118 PMCID: PMC7833769 DOI: 10.1080/19336950.2020.1870087] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Mutations in the voltage-gated sodium channel Nav1.7 are linked to human pain. The Nav1.7/N1245S variant was described before in several patients suffering from primary erythromelalgia and/or olfactory hypersensitivity. We have identified this variant in a pain patient and a patient suffering from severe and life-threatening orthostatic hypotension. In addition, we report a female patient suffering from muscle pain and carrying the Nav1.7/E1139K variant. We tested both Nav1.7 variants by whole-cell voltage-clamp recordings in HEK293 cells, revealing a slightly enhanced current density for the N1245S variant when co-expressed with the β1 subunit. This effect was counteracted by an enhanced slow inactivation. Both variants showed similar voltage dependence of activation and steady-state fast inactivation, as well as kinetics of fast inactivation, deactivation, and use-dependency compared to WT Nav1.7. Finally, homology modeling revealed that the N1245S substitution results in different intramolecular interaction partners. Taken together, these experiments do not point to a clear pathogenic effect of either the N1245S or E1139K variant and suggest they may not be solely responsible for the patients’ pain symptoms. As discussed previously for other variants, investigations in heterologous expression systems may not sufficiently mimic the pathophysiological situation in pain patients, and single nucleotide variants in other genes or modulatory proteins are necessary for these specific variants to show their effect. Our findings stress that biophysical investigations of ion channel mutations need to be evaluated with care and should preferably be supplemented with studies investigating the mutations in their context, ideally in human sensory neurons.
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Affiliation(s)
- Kim Le Cann
- Institute of Physiology, RWTH Aachen University Hospital , Aachen, Germany
| | - Jannis E Meents
- Institute of Physiology, RWTH Aachen University Hospital , Aachen, Germany
| | | | - Maike F Dohrn
- Department of Neurology, Medical Faculty, RWTH Aachen University Hospital , Aachen, Germany
| | - Raya Bott
- Institute of Physiology, RWTH Aachen University Hospital , Aachen, Germany
| | - Andrea Maier
- Department of Neurology, Medical Faculty, RWTH Aachen University Hospital , Aachen, Germany
| | - Martin Bialer
- Division of Clinical Metabolism of Medical Genetics and Human Genomics at Northwell Health System , New-York, United States
| | - Petra Hautvast
- Institute of Physiology, RWTH Aachen University Hospital , Aachen, Germany
| | - Andelain Erickson
- Institute of Physiology, RWTH Aachen University Hospital , Aachen, Germany
| | - Roman Rolke
- Department for Palliative Care, Medical Faculty, RWTH Aachen University , Aachen, Germany
| | - Markus Rothermel
- Department of Chemosensation, AG Neuromodulation, Institute for Biology II, RWTH Aachen University , Aachen, 52074, Germany
| | - Jannis Körner
- Institute of Physiology, RWTH Aachen University Hospital , Aachen, Germany.,Department of Anaesthesiology, Medical Faculty, RWTH Aachen University , Aachen, Germany
| | - Ingo Kurth
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University Hospital , Aachen, Germany
| | - Angelika Lampert
- Institute of Physiology, RWTH Aachen University Hospital , Aachen, Germany
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