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Stagno C, Mancuso F, Ciaglia T, Ostacolo C, Piperno A, Iraci N, Micale N. In Silico Methods for the Discovery of Kv7.2/7.3 Channels Modulators: A Comprehensive Review. Molecules 2024; 29:3234. [PMID: 38999185 PMCID: PMC11243076 DOI: 10.3390/molecules29133234] [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: 06/15/2024] [Revised: 07/03/2024] [Accepted: 07/05/2024] [Indexed: 07/14/2024] Open
Abstract
The growing interest in Kv7.2/7.3 agonists originates from the involvement of these channels in several brain hyperexcitability disorders. In particular, Kv7.2/7.3 mutants have been clearly associated with epileptic encephalopathies (DEEs) as well as with a spectrum of focal epilepsy disorders, often associated with developmental plateauing or regression. Nevertheless, there is a lack of available therapeutic options, considering that retigabine, the only molecule used in clinic as a broad-spectrum Kv7 agonist, has been withdrawn from the market in late 2016. This is why several efforts have been made both by both academia and industry in the search for suitable chemotypes acting as Kv7.2/7.3 agonists. In this context, in silico methods have played a major role, since the precise structures of different Kv7 homotetramers have been only recently disclosed. In the present review, the computational methods used for the design of Kv.7.2/7.3 small molecule agonists and the underlying medicinal chemistry are discussed in the context of their biological and structure-function properties.
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Affiliation(s)
- Claudio Stagno
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences (CHIBIOFARAM), University of Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Francesca Mancuso
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences (CHIBIOFARAM), University of Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Tania Ciaglia
- Department of Pharmacy, University of Salerno, Via G. Paolo II, 84084 Fisciano, Italy
| | - Carmine Ostacolo
- Department of Pharmacy, University of Salerno, Via G. Paolo II, 84084 Fisciano, Italy
| | - Anna Piperno
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences (CHIBIOFARAM), University of Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Nunzio Iraci
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences (CHIBIOFARAM), University of Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Nicola Micale
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences (CHIBIOFARAM), University of Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy
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Ahmed AI, Al-Nuaimi S, Mustafa A, Zeidan A, Agouni A, Djouhri L. K v7 Channel Activators Flupirtine and ML213 Alleviate Neuropathic Pain Behavior in the Streptozotocin Rat Model of Diabetic Neuropathy. J Pain Res 2024; 17:2267-2278. [PMID: 38947132 PMCID: PMC11214752 DOI: 10.2147/jpr.s467535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 06/18/2024] [Indexed: 07/02/2024] Open
Abstract
Background & Objective Chronic peripheral neuropathic pain (PNP) is a debilitating condition that is associated with many types of injury/diseases, including diabetes mellitus. Patients with longstanding diabetes develop diabetic PNP (DPNP), which is resilient to currently available drugs. The underlying molecular mechanisms of DPNP are still illusive, but Kv7 channels that have been implicated in the pathogenesis of various types of chronic pain are likely to be involved. Indeed, using the streptozotocin (STZ) rat model of DPNP, we have previously shown that Kv7 activation with their non-selective activator retigabine attenuated neuropathic pain behavior suggesting that these channels are implicated in DPNP pathogenesis. Here, we evaluated, in the same STZ model, whether the more potent and more selective Kv7 channel openers flupirtine and ML213 attenuate STZ-induced pain hypersensitivity. Methods Male Sprague Dawley rats (250-300 g) were used. The STZ model involved a single injection of STZ (60 mg/kg, i.p.). Behavioral testing for mechanical and heat pain sensitivity was performed using a dynamic plantar aesthesiometer and Hargreaves analgesiometer, respectively. Results STZ rats exhibited behavioral signs of mechanical and heat hypersensitivity as indicated by significant decreases in the mean paw withdrawal threshold (PWT) and mean paw withdrawal latency (PWL), respectively, at 35 days post-STZ treatment. Single injections of flupirtine (10 mg/kg, i.p.) and ML213 (5 mg/kg, i.p.) to STZ rats (35-days after STZ treatment) caused significant increases in the mean PWT, but not PWL, indicating attenuation of mechanical, but not heat hypersensitivity. Both flupirtine and ML213 were as effective as the positive control gabapentin (10/kg, i.p.), and their anti-allodynic effects were prevented by the Kv7 channel-specific blocker XE991 (3 mg/kg, i.p.). Conclusion The findings suggest that Kv7 channels are involved in the mechanisms of mechanical but not heat hypersensitivity associated with DPNP, and that their activation may prove to be effective in alleviating DPNP symptoms.
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Affiliation(s)
- Ashraf Ibrahim Ahmed
- Department of Basic Medical Science, College of Medicine, QU Health, Qatar University, Doha, Qatar
| | - Salma Al-Nuaimi
- Department of Basic Medical Science, College of Medicine, QU Health, Qatar University, Doha, Qatar
| | - Ayman Mustafa
- Department of Basic Medical Science, College of Medicine, QU Health, Qatar University, Doha, Qatar
| | - Asad Zeidan
- Department of Basic Medical Science, College of Medicine, QU Health, Qatar University, Doha, Qatar
| | - Abdelali Agouni
- Department of Pharmaceutical Sciences, College of Pharmacy, QU health, Qatar University, Doha, Qatar
| | - Laiche Djouhri
- Department of Basic Medical Science, College of Medicine, QU Health, Qatar University, Doha, Qatar
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Lattanzi S, Trinka E, Meletti S, Striano P, Matricardi S, Silvestrini M, Brigo F. A profile of azetukalner for the treatment of epilepsy: from pharmacology to potential for therapy. Expert Rev Clin Pharmacol 2024; 17:423-432. [PMID: 38571335 DOI: 10.1080/17512433.2024.2337012] [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: 01/20/2024] [Accepted: 03/27/2024] [Indexed: 04/05/2024]
Abstract
INTRODUCTION Epilepsies are a group of heterogeneous brain disorder, and antiseizure medications (ASMs) are the mainstay of treatment. Despite the availability of more than 30 drugs, at least one third of individuals with epilepsy are drug-resistant. This emphasizes the need for novel compounds that combine efficacy with improved tolerability. AREAS COVERED A literature review on the pharmacology, efficacy, tolerability, and safety of azetukalner (XEN1101), a second-generation opener of neuronal potassium channels currently in Phase 3 development as ASM. EXPERT OPINION Results from the phase 2b clinical trial strongly support the ongoing clinical development of azetukalner as a new ASM. Its pharmacokinetic properties support convenient once-daily dosing, eliminating the need for titration at initiation or tapering at the conclusion of treatment. CYP3A4 is the main enzyme involved in its metabolism and drug-drug interactions can affect the drug exposure. Preliminary analysis of an ongoing open-label study reveals no reported pigmentary abnormalities. The upcoming Phase 3 clinical trials are expected to provide further insight into the efficacy, tolerability, and safety of azetukalner in treating focal-onset and primary generalized tonic-clonic seizures. Structurally distinct from currently marketed ASMs, azetukalner has the potential to be the only-in-class Kv7.2/7.3 opener on the market upon regulatory approval.
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Affiliation(s)
- Simona Lattanzi
- Neurological Clinic, Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
| | - Eugen Trinka
- Department of Neurology, Neurointensive Care, and Neurorehabilitation, Christian Doppler University Hospital, Salzburg, Austria
- Neuroscience Institute, Center for Cognitive Neuroscience, Christian Doppler University Hospital Salzburg, Salzburg, Austria
- Public Health, Health Services Research and HTA, University for Health Sciences, Medical Informatics and Technology, Hall, Austria
| | - Stefano Meletti
- Department of Biomedical, Metabolic and Neural Science, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena, Italy
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, "G. Gaslini" Institute, University of Genoa, Genova, Italy
| | - Sara Matricardi
- Department of Pediatrics, University of Chieti, Chieti, Italy
| | - Mauro Silvestrini
- Neurological Clinic, Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
| | - Francesco Brigo
- Innovation, Research and Teaching Service (SABES-ASDAA), Teaching Hospital of the Paracelsus Medical Private University (PMU), Bolzano, Italy
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Jiang S, Liu B, Lin K, Li L, Li R, Tan S, Zhang X, Jiang L, Ni H, Wang Y, Ding H, Hu J, Qian H, Ge R. Impacted spike frequency adaptation associated with reduction of KCNQ2/3 exacerbates seizure activity in temporal lobe epilepsy. Hippocampus 2024; 34:58-72. [PMID: 38049972 DOI: 10.1002/hipo.23587] [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: 01/09/2022] [Revised: 09/21/2023] [Accepted: 10/28/2023] [Indexed: 12/06/2023]
Abstract
Numerous epilepsy-related genes have been identified in recent decades by unbiased genome-wide screens. However, the available druggable targets for temporal lobe epilepsy (TLE) remain limited. Furthermore, a substantial pool of candidate genes potentially applicable to TLE therapy awaits further validation. In this study, we reveal the significant role of KCNQ2 and KCNQ3, two M-type potassium channel genes, in the onset of seizures in TLE. Our investigation began with a quantitative analysis of two publicly available TLE patient databases to establish a correlation between seizure onset and the downregulated expression of KCNQ2/3. We then replicated these pathological changes in a pilocarpine seizure mouse model and observed a decrease in spike frequency adaptation due to the affected M-currents in dentate gyrus granule neurons. In addition, we performed a small-scale simulation of the dentate gyrus network and confirmed that the impaired spike frequency adaptation of granule cells facilitated epileptiform activity throughout the network. This, in turn, resulted in prolonged seizure duration and reduced interictal intervals. Our findings shed light on an underlying mechanism contributing to ictogenesis in the TLE hippocampus and suggest a promising target for the development of antiepileptic drugs.
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Affiliation(s)
- Shicheng Jiang
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Bei Liu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Kaiwen Lin
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Lianjun Li
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Rongrong Li
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Shuo Tan
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Xinyu Zhang
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Lei Jiang
- Department of General Surgery, The Second Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, China
| | - Hong Ni
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Yuanyuan Wang
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Haihu Ding
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Bengbu Medical College, Bengbu, Anhui, China
| | - Jing Hu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Hao Qian
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Rongjing Ge
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
- Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Bengbu Medical College, Bengbu, Anhui, China
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Qian X, Zhao X, Yu L, Yin Y, Zhang XD, Wang L, Li JX, Zhu Q, Luo JL. Current status of GABA receptor subtypes in analgesia. Biomed Pharmacother 2023; 168:115800. [PMID: 37935070 DOI: 10.1016/j.biopha.2023.115800] [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: 08/01/2023] [Revised: 10/15/2023] [Accepted: 10/26/2023] [Indexed: 11/09/2023] Open
Abstract
Gamma-aminobutyric acid (GABA), a non-protein-producing amino acid synthesized from the excitatory amino acid glutamate via the enzyme glutamic acid decarboxylase, is extensively found in microorganisms, plants and vertebrates, and is abundantly expressed in the spinal cord and brain. It is the major inhibitory neurotransmitter in the mammalian nervous system. GABA plays crucial roles in the regulation of synaptic transmission, the promotion of neuronal development and relaxation, and the prevention of insomnia and depression. As the major inhibitory neurotransmitter, GABA plays pivotal roles in the regulation of pain sensation, which is initiated by the activation of peripheral nociceptors and transmitted to the spinal cord and brain along nerves. GABA exerts these roles by directly acting on three types of receptors: ionotropic GABAA and GABAC receptors and G protein-coupled GABAB receptor. The chloride-permeable ion channel receptors GABAA and GABAC mediate fast neurotransmission, while the metabotropic GABAB receptor mediates slow effect. Different GABA receptors regulate pain sensation via different signaling pathways. Here we highlight recent updates on the involvement of specific GABA receptors and their subtypes in the process of pain sensation. Further understanding of different GABA receptors and signaling pathways in pain sensation will benefit the development of novel analgesics for pain management by targeting specific GABA receptor subtypes and signaling pathways.
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Affiliation(s)
- Xunjia Qian
- School of Pharmacy, Nantong University, Nantong 226001, Jiangsu, China
| | - Xinyi Zhao
- School of Pharmacy, Nantong University, Nantong 226001, Jiangsu, China
| | - Lulu Yu
- School of Pharmacy, Nantong University, Nantong 226001, Jiangsu, China
| | - Yujian Yin
- School of Pharmacy, Nantong University, Nantong 226001, Jiangsu, China
| | - Xiao-Dan Zhang
- School of Pharmacy, Nantong University, Nantong 226001, Jiangsu, China
| | - Liyun Wang
- School of Pharmacy, Nantong University, Nantong 226001, Jiangsu, China
| | - Jun-Xu Li
- School of Pharmacy, Nantong University, Nantong 226001, Jiangsu, China; Provincial Key Laboratory of Inflammation and Molecular Drug Target, Nantong 226001, Jiangsu, China
| | - Qing Zhu
- School of Pharmacy, Nantong University, Nantong 226001, Jiangsu, China; Provincial Key Laboratory of Inflammation and Molecular Drug Target, Nantong 226001, Jiangsu, China.
| | - Jia-Lie Luo
- School of Pharmacy, Nantong University, Nantong 226001, Jiangsu, China.
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Ma D, Zheng Y, Li X, Zhou X, Yang Z, Zhang Y, Wang L, Zhang W, Fang J, Zhao G, Hou P, Nan F, Yang W, Su N, Gao Z, Guo J. Ligand activation mechanisms of human KCNQ2 channel. Nat Commun 2023; 14:6632. [PMID: 37857637 PMCID: PMC10587151 DOI: 10.1038/s41467-023-42416-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 10/10/2023] [Indexed: 10/21/2023] Open
Abstract
The human voltage-gated potassium channel KCNQ2/KCNQ3 carries the neuronal M-current, which helps to stabilize the membrane potential. KCNQ2 can be activated by analgesics and antiepileptic drugs but their activation mechanisms remain unclear. Here we report cryo-electron microscopy (cryo-EM) structures of human KCNQ2-CaM in complex with three activators, namely the antiepileptic drug cannabidiol (CBD), the lipid phosphatidylinositol 4,5-bisphosphate (PIP2), and HN37 (pynegabine), an antiepileptic drug in the clinical trial, in an either closed or open conformation. The activator-bound structures, along with electrophysiology analyses, reveal the binding modes of two CBD, one PIP2, and two HN37 molecules in each KCNQ2 subunit, and elucidate their activation mechanisms on the KCNQ2 channel. These structures may guide the development of antiepileptic drugs and analgesics that target KCNQ2.
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Affiliation(s)
- Demin Ma
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China
- Nanhu Brain-computer Interface Institute, Hangzhou, 311100, China
| | - Yueming Zheng
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, 100049, China
| | - Xiaoxiao Li
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China
- Nanhu Brain-computer Interface Institute, Hangzhou, 311100, China
| | - Xiaoyu Zhou
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, 100049, China
| | - Zhenni Yang
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China
- Nanhu Brain-computer Interface Institute, Hangzhou, 311100, China
| | - Yan Zhang
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China
- Nanhu Brain-computer Interface Institute, Hangzhou, 311100, China
| | - Long Wang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Wenbo Zhang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Jiajia Fang
- Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, 322000, China
| | - Guohua Zhao
- Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, 322000, China
| | - Panpan Hou
- Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR, China
| | - Fajun Nan
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, 100049, China
| | - Wei Yang
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China
| | - Nannan Su
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China
| | - Zhaobing Gao
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, 100049, China.
- Zhongshan Institute for Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zhongshan, 528437, China.
| | - Jiangtao Guo
- Department of Biophysics and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China.
- Nanhu Brain-computer Interface Institute, Hangzhou, 311100, China.
- Department of Cardiology, Key Laboratory of Cardiovascular Intervention and Regenerative Medicine of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310016, China.
- Liangzhu Laboratory, Zhejiang University Medical Center, 1369 West Wenyi Road, Hangzhou, Zhejiang, 311121, China.
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China.
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
- Cancer Center, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
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Arias ER, Sánchez-Tafolla BM, Terrón C, Martínez LA, Zetina ME, Morales MA, Cifuentes F. Long-term potentiation and its neurotrophin-dependent modulation in the superior cervical ganglion of the rat are influenced by KCNQ channel function. Can J Physiol Pharmacol 2023; 101:539-547. [PMID: 37406358 DOI: 10.1139/cjpp-2022-0552] [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] [Indexed: 07/07/2023]
Abstract
Ganglionic long-term potentiation (gLTP) in the rat superior cervical ganglion (SCG) is differentially modulated by neurotrophic factors (Nts): brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF). KCNQ/M channels, key regulators of neuronal excitability, and firing pattern are modulated by Nts; therefore, they might contribute to gLTP expression and to the Nts-dependent modulation of gLTP. In the SCG of rats, we characterized the presence of the KCNQ2 isoform and the effects of opposite KCNQ/M channel modulators on gLTP in control condition and under Nts modulation. Immunohistochemical and reverse transcriptase polymerase chain reaction analyses showed the expression of the KCNQ2 isoform. We found that 1 µmol/L XE991, a channel inhibitor, significantly reduced gLTP (∼50%), whereas 5 µmol/L flupirtine, a channel activator, significantly increased gLTP (1.3- to 1.7-fold). Both modulators counterbalanced the effects of the Nts on gLTP. Data suggest that KCNQ/M channels are likely involved in gLTP expression and in the modulation exerted by BDNF and NGF.
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Affiliation(s)
- Erwin R Arias
- Departamento de Biología Celular & Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, C.U., Coyoacán 04510, Ciudad de México, México
| | - Berardo M Sánchez-Tafolla
- Departamento de Biología Celular & Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, C.U., Coyoacán 04510, Ciudad de México, México
| | - Carlos Terrón
- Departamento de Biología Celular & Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, C.U., Coyoacán 04510, Ciudad de México, México
| | - Luis A Martínez
- Departamento de Biología Celular & Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, C.U., Coyoacán 04510, Ciudad de México, México
| | - Maria E Zetina
- Departamento de Biología Celular & Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, C.U., Coyoacán 04510, Ciudad de México, México
| | - Miguel A Morales
- Departamento de Biología Celular & Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, C.U., Coyoacán 04510, Ciudad de México, México
| | - Fredy Cifuentes
- Departamento de Biología Celular & Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, C.U., Coyoacán 04510, Ciudad de México, México
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8
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Alam KA, Svalastoga P, Martinez A, Glennon JC, Haavik J. Potassium channels in behavioral brain disorders. Molecular mechanisms and therapeutic potential: A narrative review. Neurosci Biobehav Rev 2023; 152:105301. [PMID: 37414376 DOI: 10.1016/j.neubiorev.2023.105301] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/26/2023] [Accepted: 06/30/2023] [Indexed: 07/08/2023]
Abstract
Potassium channels (K+-channels) selectively control the passive flow of potassium ions across biological membranes and thereby also regulate membrane excitability. Genetic variants affecting many of the human K+-channels are well known causes of Mendelian disorders within cardiology, neurology, and endocrinology. K+-channels are also primary targets of many natural toxins from poisonous organisms and drugs used within cardiology and metabolism. As genetic tools are improving and larger clinical samples are being investigated, the spectrum of clinical phenotypes implicated in K+-channels dysfunction is rapidly expanding, notably within immunology, neurosciences, and metabolism. K+-channels that previously were considered to be expressed in only a few organs and to have discrete physiological functions, have recently been found in multiple tissues and with new, unexpected functions. The pleiotropic functions and patterns of expression of K+-channels may provide additional therapeutic opportunities, along with new emerging challenges from off-target effects. Here we review the functions and therapeutic potential of K+-channels, with an emphasis on the nervous system, roles in neuropsychiatric disorders and their involvement in other organ systems and diseases.
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Affiliation(s)
| | - Pernille Svalastoga
- Mohn Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway; Children and Youth Clinic, Haukeland University Hospital, Bergen, Norway
| | | | - Jeffrey Colm Glennon
- Conway Institute for Biomolecular and Biomedical Research, School of Medicine, University College Dublin, Dublin, Ireland.
| | - Jan Haavik
- Department of Biomedicine, University of Bergen, Norway; Division of Psychiatry, Haukeland University Hospital, Norway.
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Huang CN, Chen YM, Xiao XY, Zhou HL, Zhu J, Qin HM, Jiang X, Li Z, Zhuang T, Zhang GS. Pregabalin can interact synergistically with Kv7 channel openers to exert antinociception in mice. Eur J Pharmacol 2023:175870. [PMID: 37353189 DOI: 10.1016/j.ejphar.2023.175870] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 06/10/2023] [Accepted: 06/20/2023] [Indexed: 06/25/2023]
Abstract
Chronic pain is a common public health problem and remains an unmet medical need. Currently available analgesics usually have limited efficacy for the treatment of chronic pain, including neuropathic pain and persistent inflammatory pain, or they are accompanied by many adverse side effects. The voltage-gated calcium channel blocker (pregabalin) and potassium channel openers (flupirtine and retigabine) have been widely used for the management of chronic pain, but their effectiveness in combination is unclear. In this research, we evaluated the antinociceptive effects of pregabalin in combination with flupirtine or retigabine in carrageenan-induced inflammatory pain and paclitaxel-induced peripheral neuropathy in mice using the von Frey test. Isobolographic analysis indicated that pregabalin exerted synergistic antinociceptive effects when combined with flupirtine or retigabine in neuropathic and inflammatory pain models. Furthermore, the antinociceptive effects of pregabalin, flupirtine/retigabine, and their combinations were significantly attenuated by the Kv7 channel blocker XE991. The favored dose ratio between pregabalin and flupirtine/retigabine in combinations was also investigated. Finally, we evaluated the motor coordination of their combinations using the rotarod test, and the outcomes underpinned their safety. Collectively, our results support the potential use of pregabalin in combination with flupirtine or retigabine to alleviate chronic pain.
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Affiliation(s)
- Chao-Nan Huang
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, School of Pharmacy, Jiangsu Ocean University, Lianyungang, 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Yan-Ming Chen
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, School of Pharmacy, Jiangsu Ocean University, Lianyungang, 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Xin-Yi Xiao
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, School of Pharmacy, Jiangsu Ocean University, Lianyungang, 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Hui-Ling Zhou
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, School of Pharmacy, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Jin Zhu
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, School of Pharmacy, Jiangsu Ocean University, Lianyungang, 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Hui-Min Qin
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, School of Pharmacy, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Xue Jiang
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, School of Pharmacy, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Zongzheng Li
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, School of Pharmacy, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Tao Zhuang
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, School of Pharmacy, Jiangsu Ocean University, Lianyungang, 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China.
| | - Gui-Sen Zhang
- Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, School of Pharmacy, Jiangsu Ocean University, Lianyungang, 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China.
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10
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Bian WJ, Brewer CL, Kauer JA, de Lecea L. Adolescent sleep shapes social novelty preference in mice. Nat Neurosci 2022; 25:912-923. [PMID: 35618950 PMCID: PMC9283223 DOI: 10.1038/s41593-022-01076-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 04/14/2022] [Indexed: 12/17/2022]
Abstract
Sleep disturbances frequently occur in neurodevelopmental disorders such as autism, but the developmental role of sleep is largely unexplored, and a causal relationship between developmental sleep defects and behavioral consequences in adulthood remains elusive. Here, we show that in mice, sleep disruption (SD) in adolescence, but not in adulthood, causes long-lasting impairment in social novelty preference. Furthermore, adolescent SD alters the activation and release patterns of dopaminergic neurons in the ventral tegmental area (VTA) in response to social novelty. This developmental sleep function is mediated by balanced VTA activity during adolescence; chemogenetic excitation mimics, whereas silencing rescues, the social deficits of adolescent SD. Finally, we show that in Shank3-mutant mice, improving sleep or rectifying VTA activity during adolescence ameliorates adult social deficits. Together, our results identify a critical role of sleep and dopaminergic activity in the development of social interaction behavior.
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Affiliation(s)
- Wen-Jie Bian
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA.
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA.
| | - Chelsie L Brewer
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA
| | - Julie A Kauer
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA.
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA.
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11
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Borgini M, Mondal P, Liu R, Wipf P. Chemical modulation of Kv7 potassium channels. RSC Med Chem 2021; 12:483-537. [PMID: 34046626 PMCID: PMC8128042 DOI: 10.1039/d0md00328j] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/01/2020] [Indexed: 01/10/2023] Open
Abstract
The rising interest in Kv7 modulators originates from their ability to evoke fundamental electrophysiological perturbations in a tissue-specific manner. A large number of therapeutic applications are, in part, based on the clinical experience with two broad-spectrum Kv7 agonists, flupirtine and retigabine. Since precise molecular structures of human Kv7 channel subtypes in closed and open states have only very recently started to emerge, computational studies have traditionally been used to analyze binding modes and direct the development of more potent and selective Kv7 modulators with improved safety profiles. Herein, the synthetic and medicinal chemistry of small molecule modulators and the representative biological properties are summarized. Furthermore, new therapeutic applications supported by in vitro and in vivo assay data are suggested.
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Affiliation(s)
- Matteo Borgini
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
| | - Pravat Mondal
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
| | - Ruiting Liu
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
| | - Peter Wipf
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
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12
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Lawson K, Singh A, Kantsedikas I, Jenner CA, Austen DK. Flupirtine as a Potential Treatment for Fibromyalgia. JOURNAL OF EXPLORATORY RESEARCH IN PHARMACOLOGY 2021; 000:000-000. [DOI: 10.14218/jerp.2020.00043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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13
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Löscher W, Sills GJ, White HS. The ups and downs of alkyl-carbamates in epilepsy therapy: How does cenobamate differ? Epilepsia 2021; 62:596-614. [PMID: 33580520 DOI: 10.1111/epi.16832] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/11/2021] [Accepted: 01/13/2021] [Indexed: 12/13/2022]
Abstract
Since 1955, several alkyl-carbamates have been developed for the treatment of anxiety and epilepsy, including meprobamate, flupirtine, felbamate, retigabine, carisbamate, and cenobamate. They have each enjoyed varying levels of success as antiseizure drugs; however, they have all been plagued by the emergence of serious and sometimes life-threatening adverse events. In this review, we compare and contrast their predominant molecular mechanisms of action, their antiseizure profile, and where possible, their clinical efficacy. The preclinical, clinical, and mechanistic profile of the prototypical γ-aminobutyric acidergic (GABAergic) modulator phenobarbital is included for comparison. Like phenobarbital, all of the clinically approved alkyl-carbamates share an ability to enhance inhibitory neurotransmission through modulation of the GABAA receptor, although the specific mechanism of interaction differs among the different drugs discussed. In addition, several alkyl-carbamates have been shown to interact with voltage-gated ion channels. Flupirtine and retigabine share an ability to activate K+ currents mediated by KCNQ (Kv7) K+ channels, and felbamate, carisbamate, and cenobamate have been shown to block Na+ channels. In contrast to other alkyl-carbamates, cenobamate seems to be unique in its ability to preferentially attenuate the persistent rather than transient Na+ current. Results from recent randomized controlled clinical trials with cenobamate suggest that this newest antiseizure alkyl-carbamate possesses a degree of efficacy not witnessed since felbamate was approved in 1993. Given that ceno-bamate's mechanistic profile is unique among the alkyl-carbamates, it is not clear whether this impressive efficacy reflects an as yet undescribed mechanism of action or whether it possesses a unique synergy between its actions at the GABAA receptor and on persistent Na+ currents. The high efficacy of cenobamate is, however, tempered by the risk of serious rash and low tolerability at higher doses, meaning that further safety studies and clinical experience are needed to determine the true clinical value of cenobamate.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience Hannover, Hannover, Germany
| | - Graeme J Sills
- School of Life Sciences, University of Glasgow, Glasgow, UK
| | - H Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, USA
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14
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Wang J, Liu Y, Hu F, Yang J, Guo X, Hou X, Ju C, Wang K. Activation of Neuronal Voltage-Gated Potassium Kv7/KCNQ/M-Current by a Novel Channel Opener SCR2682 for Alleviation of Chronic Pain. J Pharmacol Exp Ther 2021; 377:20-28. [DOI: 10.1124/jpet.120.000357] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 01/06/2021] [Indexed: 12/20/2022] Open
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15
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Li X, Zhang Q, Guo P, Fu J, Mei L, Lv D, Wang J, Lai D, Ye S, Yang H, Guo J. Molecular basis for ligand activation of the human KCNQ2 channel. Cell Res 2021; 31:52-61. [PMID: 32884139 PMCID: PMC7852908 DOI: 10.1038/s41422-020-00410-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/14/2020] [Indexed: 01/10/2023] Open
Abstract
The voltage-gated potassium channel KCNQ2 is responsible for M-current in neurons and is an important drug target to treat epilepsy, pain and several other diseases related to neuronal hyper-excitability. A list of synthetic compounds have been developed to directly activate KCNQ2, yet our knowledge of their activation mechanism is limited, due to lack of high-resolution structures. Here, we report cryo-electron microscopy (cryo-EM) structures of the human KCNQ2 determined in apo state and in complex with two activators, ztz240 or retigabine, which activate KCNQ2 through different mechanisms. The activator-bound structures, along with electrophysiology analysis, reveal that ztz240 binds at the voltage-sensing domain and directly stabilizes it at the activated state, whereas retigabine binds at the pore domain and activates the channel by an allosteric modulation. By accurately defining ligand-binding sites, these KCNQ2 structures not only reveal different ligand recognition and activation mechanisms, but also provide a structural basis for drug optimization and design.
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Affiliation(s)
- Xiaoxiao Li
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China
| | - Qiansen Zhang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China
| | - Peipei Guo
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China
| | - Jie Fu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China
| | - Lianghe Mei
- Suzhou Institute of Drug Innovation, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 108 Yuxin Road, Suzhou, Jiangsu, 215123, China
| | - Dashuai Lv
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Jiangqin Wang
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China
| | - Dongwu Lai
- Department of Cardiology, Key Laboratory of Cardiovascular Intervention and Regenerative Medicine of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310016, China
| | - Sheng Ye
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, 310058, China
- School of Life Sciences, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, China
| | - Huaiyu Yang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China.
| | - Jiangtao Guo
- Department of Biophysics, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China.
- Department of Cardiology, Key Laboratory of Cardiovascular Intervention and Regenerative Medicine of Zhejiang Province, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310016, China.
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16
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Vilela M, Fernandes D, Salazar T, Duarte A. Hulk-Like Urine: A Case of Green Urine Caused by Flupirtine Intoxication. Cureus 2020; 12:e12333. [PMID: 33520530 PMCID: PMC7839280 DOI: 10.7759/cureus.12333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/28/2020] [Indexed: 12/01/2022] Open
Abstract
Acute intoxications are common causes of admission to the Emergency Department (ED). Flupirtine is a non-opioid analgesic, originally used for acute and chronic pain. Because of several reports of severe liver toxicity, its use was limited to acute pain in 2013 by the European Medicines Agency. Although withdrawn from the European market in March 2018, there are still flupirtine tablets in many households, and most people are unaware of the hazards they might be facing. A 58-year-old man was admitted to the ED after a suicide attempt with 1 g of flupirtine. He was lethargic and confused but presented no focal neurological deficits or other symptoms, and the rest of his clinical examination was unremarkable. His cerebral CAT and blood chemistry showed no alterations. The only remarkable feature was that he had green urine. After a careful literature search, a similar case was found caused by flupirtine intoxication. After 24 hours of vigilance in the ED, he improved his neurological status and his urine lost part of its greenish color. He was then transferred to the Psychiatric Department, where he presented a complete remission of the clinical alterations. A follow-up check-up showed no permanent deficits.
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Affiliation(s)
- Maria Vilela
- Internal Medicine, Centro Hospitalar do Médio Ave, Vila Nova de Famalicão, PRT
| | - Diana Fernandes
- Internal Medicine, Centro Hospitalar Do Médio Ave, Vila Nova de Famalicão, PRT
| | - Tatiana Salazar
- Internal Medicine, Centro Hospitalar Do Médio Ave, Vila Nova de Famalicão, PRT
| | - Augusto Duarte
- Internal Medicine, Centro Hospitalar do Médio Ave, Vila Nova de Famalicão, PRT
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17
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Matsumoto Y, Fujino Y, Furue H. Anti-nociceptive and anxiolytic effects of systemic flupirtine and its direct inhibitory actions on in vivo neuronal mechanical sensory responses in the adult rat anterior cingulate cortex. Biochem Biophys Res Commun 2020; 531:528-534. [DOI: 10.1016/j.bbrc.2020.07.129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 07/28/2020] [Indexed: 11/26/2022]
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18
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Vicente-Baz J, Rivera-Arconada I. Spinal Actions of the NSAID Diclofenac on Nociceptive Transmission in Comparison to the K v7 Channel Opener Flupirtine. Neuroscience 2020; 440:186-195. [PMID: 32505744 DOI: 10.1016/j.neuroscience.2020.05.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/27/2020] [Accepted: 05/28/2020] [Indexed: 10/24/2022]
Abstract
NSAIDs are the drugs most commonly used to alleviate pain. Despite being a heterogeneous group of compounds, all of them share a mechanism of action based on blockade of COXs enzymes, which confers them anti-inflammatory and analgesic properties. Diclofenac is a NSAID with preferred activity on COX-2 isozymes, but additionally, other targets may be implicated in its analgesic activity. Among them, diclofenac may facilitate the activity of Kv7 channels, that have been previously recognized as potential therapeutic targets in analgesia. In this study, the antinociceptive actions of diclofenac acting at the spinal level and the role of Kv7 channels in its effects were evaluated. Electrophysiological recordings of spinal reflexes and responses of dorsal horn neurons were obtained using in vitro spinal cord preparations from neonatal mice. Diclofenac, applied at clinically relevant concentrations to the entire preparation, depressed wind-up of spinal reflexes with a pattern similar to that of flupirtine, an analgesic with activity as Kv7 channel opener. Depressant actions of both compounds were strongly reduced after Kv7 channel blockade with XE-991, indicating the implication of these channels in the observed effects. Flupirtine, but not diclofenac, also reduced action potential firing of dorsal horn neurons in response to electrical activation of nociceptive afferents, suggesting differences in the actions of both compounds on Kv7 channel configurations present in sensory areas of the cord. Results demonstrate previously unknown central actions of diclofenac on Kv7 channels located in spinal circuits, expanding the knowledge about its pharmacological actions.
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Affiliation(s)
- Jorge Vicente-Baz
- Department of Systems Biology (Physiology), Universidad de Alcala, Alcala de Henares, Madrid, Spain
| | - Ivan Rivera-Arconada
- Department of Systems Biology (Physiology), Universidad de Alcala, Alcala de Henares, Madrid, Spain.
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19
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Wang J, Bwayi M, Florke Gee RR, Chen T. PXR-mediated idiosyncratic drug-induced liver injury: mechanistic insights and targeting approaches. Expert Opin Drug Metab Toxicol 2020; 16:711-722. [PMID: 32500752 PMCID: PMC7429329 DOI: 10.1080/17425255.2020.1779701] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 06/04/2020] [Indexed: 01/03/2023]
Abstract
INTRODUCTION The human liver is the center for drug metabolism and detoxification and is, therefore, constantly exposed to toxic chemicals. The loss of liver function as a result of this exposure is referred to as drug-induced liver injury (DILI). The pregnane X receptor (PXR) is the primary regulator of the hepatic drug-clearance system, which plays a critical role in mediating idiosyncratic DILI. AREAS COVERED This review is focused on common mechanisms of PXR-mediated DILI and on in vitro and in vivo models developed to predict and assess DILI. It also provides an update on the development of PXR antagonists that may manage PXR-mediated DILI. EXPERT OPINION DILI can be caused by many factors, and PXR is clearly linked to DILI. Although emerging data illustrate how PXR mediates DILI and how PXR activity can be modulated, many questions concerning the development of effective PXR modulators remain. Future research should be focused on determining the mechanisms regulating PXR functions in different cellular contexts.
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Affiliation(s)
- Jingheng Wang
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Monicah Bwayi
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Rebecca R. Florke Gee
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
- Graduate School of Biomedical Sciences, St. Jude Children’s Research Hospital, Memphis, TN, 38105, USA
| | - Taosheng Chen
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
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20
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Vigil FA, Carver CM, Shapiro MS. Pharmacological Manipulation of K v 7 Channels as a New Therapeutic Tool for Multiple Brain Disorders. Front Physiol 2020; 11:688. [PMID: 32636759 PMCID: PMC7317068 DOI: 10.3389/fphys.2020.00688] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 05/27/2020] [Indexed: 12/12/2022] Open
Abstract
K v 7 ("M-type," KCNQ) K+ currents, play dominant roles in controlling neuronal excitability. They act as a "brake" against hyperexcitable states in the central and peripheral nervous systems. Pharmacological augmentation of M current has been developed for controlling epileptic seizures, although current pharmacological tools are uneven in practical usefulness. Lately, however, M-current "opener" compounds have been suggested to be efficacious in preventing brain damage after multiple types of insults/diseases, such as stroke, traumatic brain injury, drug addiction and mood disorders. In this review, we will discuss what is known to date on these efforts and identify gaps in our knowledge regarding the link between M current and therapeutic potential for these disorders. We will outline the preclinical experiments that are yet to be performed to demonstrate the likelihood of success of this approach in human trials. Finally, we also address multiple pharmacological tools available to manipulate different K v 7 subunits and the relevant evidence for translational application in the clinical use for disorders of the central nervous system and multiple types of brain insults. We feel there to be great potential for manipulation of K v 7 channels as a novel therapeutic mode of intervention in the clinic, and that the paucity of existing therapies obligates us to perform further research, so that patients can soon benefit from such therapeutic approaches.
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Affiliation(s)
- Fabio A Vigil
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Chase M Carver
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Mark S Shapiro
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, United States
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21
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Abd-Elsayed A, Jackson M, Gu SL, Fiala K, Gu J. Neuropathic pain and Kv7 voltage-gated potassium channels: The potential role of Kv7 activators in the treatment of neuropathic pain. Mol Pain 2020; 15:1744806919864256. [PMID: 31342847 PMCID: PMC6659175 DOI: 10.1177/1744806919864256] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Neuropathic pain conditions severely and chronically affect the quality of life
in a large human population, but the pain conditions are not adequately managed
due to poor understanding of their underlying mechanisms. There is a pressing
need for further research into this field to help develop effective and
nonaddictive medications to treat neuropathic pain. This article first describes
general clinical classification of pain, types and symptoms of neuropathic pain,
and current practices of clinical management for neuropathic pain. This is
followed by a discussion of various cellular and molecular mechanisms
responsible for the development and maintenance of neuropathic pain. In this
review, we highlight the loss of function of Kv7 voltage-gated potassium as a
mechanism of neuropathic pain and the potential use of Kv7 channel activator as
subsequent treatment.
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Affiliation(s)
- Alaa Abd-Elsayed
- 1 Department of Anesthesiology, University of Cincinnati, Cincinnati, OH, USA.,2 Department of Anesthesiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Markus Jackson
- 1 Department of Anesthesiology, University of Cincinnati, Cincinnati, OH, USA
| | - Steven L Gu
- 3 Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Kenneth Fiala
- 2 Department of Anesthesiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Jianguo Gu
- 1 Department of Anesthesiology, University of Cincinnati, Cincinnati, OH, USA.,3 Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
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22
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Hong J, Qiu J, Wang X, Zhang G. Characteristics of voltage-gated potassium currents in monosodium urate induced gouty arthritis in mice. Inflamm Res 2020; 69:589-598. [PMID: 32306120 DOI: 10.1007/s00011-020-01343-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 01/15/2020] [Accepted: 03/26/2020] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE To evaluate the role of K+ channels in pain following gouty arthritis. METHODS The model of acute gouty arthritis was induced by monosodium urate (MSU) in mice. The swelling degree was determined by measuring the circumference of the ankle joint. Mechanical hyperalgesia was detected by von Frey filaments. Two types of K+ currents, A-type currents (IA) and delayed rectifier currents (IK), were recorded in dorsal root ganglion (DRG) neurons using patch-clamp techniques. RESULTS The swelling degree reached its maximum at 10 h and the minimum pain threshold was maintained between 8 and 48 h after MSU treatment in mice. The amplitudes of IA and IK in DRG neurons were moderately increased on day 1 after MSU treatment, and then, they were gradually decreased with times and reached their minimums on day 4 (for IA) or 5 (for IK). Compared with control group, the activation curve of IA was significantly shifted to more positive potential and the recovery time of IA from inactivation was markedly prolonged, but inactivation and frequency dependence of IA appeared unaffected in MSU-treated group. Additionally, no change was observed in the activation curve of IK after MSU treatment. The excitability was significantly higher in the MSU group than in the control group. CONCLUSIONS MSU-induced gout pain may be related to the hyperexcitability of DRG neurons elicited by decreasing K+ currents.
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Affiliation(s)
- Jiangru Hong
- Department of Clinical Pharmacy, China Pharmaceutical University, Nanjing, 210009, China
| | - Jie Qiu
- Department of Clinical Pharmacy, China Pharmaceutical University, Nanjing, 210009, China
| | - Xiniao Wang
- Department of Clinical Pharmacy, China Pharmaceutical University, Nanjing, 210009, China
| | - Guangqin Zhang
- Department of Clinical Pharmacy, China Pharmaceutical University, Nanjing, 210009, China.
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Reynaert ML, Dupoiron D, Yeramian E, Marsollier L, Brodin P. Could Mycolactone Inspire New Potent Analgesics? Perspectives and Pitfalls. Toxins (Basel) 2019; 11:toxins11090516. [PMID: 31487908 PMCID: PMC6783859 DOI: 10.3390/toxins11090516] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 08/26/2019] [Accepted: 09/03/2019] [Indexed: 12/20/2022] Open
Abstract
Pain currently represents the most common symptom for which medical attention is sought by patients. The available treatments have limited effectiveness and significant side-effects. In addition, most often, the duration of analgesia is short. Today, the handling of pain remains a major challenge. One promising alternative for the discovery of novel potent analgesics is to take inspiration from Mother Nature; in this context, the detailed investigation of the intriguing analgesia implemented in Buruli ulcer, an infectious disease caused by the bacterium Mycobacterium ulcerans and characterized by painless ulcerative lesions, seems particularly promising. More precisely, in this disease, the painless skin ulcers are caused by mycolactone, a polyketide lactone exotoxin. In fact, mycolactone exerts a wide range of effects on the host, besides being responsible for analgesia, as it has been shown notably to modulate the immune response or to provoke apoptosis. Several cellular mechanisms and different targets have been proposed to account for the analgesic effect of the toxin, such as nerve degeneration, the inhibition of inflammatory mediators and the activation of angiotensin II receptor 2. In this review, we discuss the current knowledge in the field, highlighting possible controversies. We first discuss the different pain-mimicking experimental models that were used to study the effect of mycolactone. We then detail the different variants of mycolactone that were used in such models. Overall, based on the results and the discussions, we conclude that the development of mycolactone-derived molecules can represent very promising perspectives for new analgesic drugs, which could be effective for specific pain indications.
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Affiliation(s)
- Marie-Line Reynaert
- France Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR8204-CIIL-Center for Infection and Immunity of Lille, F-59000 Lille, France
| | - Denis Dupoiron
- Institut de Cancérologie de l'Ouest Paul Papin, 15 rue André Boquel-49055 Angers, France
| | - Edouard Yeramian
- Unité de Microbiologie Structurale, Institut Pasteur, CNRS, Univ. Paris, F-75015 Paris, France
| | - Laurent Marsollier
- Equipe ATIP AVENIR, CRCINA, INSERM, Univ. Nantes, Univ. Angers, 4 rue Larrey, F-49933 Angers, France.
| | - Priscille Brodin
- France Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR8204-CIIL-Center for Infection and Immunity of Lille, F-59000 Lille, France.
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Zhang F, Liu Y, Tang F, Liang B, Chen H, Zhang H, Wang K. Electrophysiological and pharmacological characterization of a novel and potent neuronal Kv7 channel opener SCR2682 for antiepilepsy. FASEB J 2019; 33:9154-9166. [DOI: 10.1096/fj.201802848rr] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Fan Zhang
- The Key Laboratory of Neural and Vascular Biology Ministry of Education The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Province Department of Pharmacology Hebei Medical University Shijiazhuang China
| | - Yani Liu
- Department of Pharmacology Qingdao University Qingdao China
| | - Feng Tang
- Medicinal Chemistry, Simcere Pharmaceutical Nanjing China
| | - Bo Liang
- Medicinal Chemistry Shanghai Zhimeng BioPharma Shanghai China
| | - Huanming Chen
- Medicinal Chemistry Shanghai Zhimeng BioPharma Shanghai China
| | - Hailin Zhang
- The Key Laboratory of Neural and Vascular Biology Ministry of Education The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Province Department of Pharmacology Hebei Medical University Shijiazhuang China
| | - Kewei Wang
- Department of Pharmacology Qingdao University Qingdao China
- Institute of Innovative Drugs School of Pharmacy Qingdao University Qingdao China
- Center for Brain Science and Brain‐Inspired Intelligence Guangzhou China
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Abstract
The highly structurally similar drugs flupirtine and retigabine have been regarded as safe and effective for many years but lately they turned out to exert intolerable side effects. While the twin molecules share the mode of action, both stabilize the open state of voltage-gated potassium channels, the form and severity of adverse effects is different. The analgesic flupirtine caused drug-induced liver injury in rare but fatal cases, whereas prolonged use of the antiepileptic retigabine led to blue tissue discoloration. Because the adverse effects seem unrelated to the mode of action, it is likely, that both drugs that occupied important therapeutic niches, could be replaced. Reasons for the clinically relevant toxicity will be clarified and future substitutes for these drugs presented in this review.
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Lawson K. Pharmacology and clinical applications of flupirtine: Current and future options. World J Pharmacol 2019; 8:1-13. [DOI: 10.5497/wjp.v8.i1.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 11/17/2018] [Accepted: 01/05/2019] [Indexed: 02/06/2023] Open
Abstract
Flupirtine is the first representative in a class of triaminopyridines that exhibits pharmacological properties leading to the suppression of over-excitability of neuronal and non-neuronal cells. Consequently, this drug has been used as a centrally acting analgesic in patients with a range of acute and persistent pain conditions without the adverse effects characteristic of opioids and non-steroidal anti-inflammatory drug and is well tolerated. The pharmacological profile exhibited involves actions on several cellular targets, including Kv7 channels, G-protein-regulated inwardly rectifying K channels and γ-aminobutyric acid type A receptors, but also there is evidence of additional as yet unidentified mechanisms of action involved in the effects of flupirtine. Flupirtine has exhibited effects in a range of cells and tissues related to the locations of these targets. In additional to analgesia, flupirtine has demonstrated pharmacological properties consistent with use as an anticonvulsant, a neuroprotectant, skeletal and smooth muscle relaxant, in treatment of auditory and visual disorders, and treatment of memory and cognitive impairment. Flupirtine is providing important information and clues regarding novel mechanistic approaches to the treatment of a range of clinical conditions involving hyper-excitability of cells. Identification of molecules exhibiting specificity for the pharmacological targets (e.g., Kv7 isoforms) involved in the actions of flupirtine will provide further insight into clinical applications. Whether the broad-spectrum pharmacology of flupirtine or target-specific actions is preferential to gain benefit, especially in complex clinical conditions, requires further investigation. This review will consider recent advancement in understanding of the pharmacological profile and related clinical applications of flupirtine.
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Affiliation(s)
- Kim Lawson
- Department of Biosciences and Chemistry, Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield S1 1WB, United Kingdom
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Patil MA, Matter BA, Raol YH, Bourne DWA, Kelley RA, Kompella UB. Brain Distribution and Metabolism of Flupirtine, a Nonopioid Analgesic Drug with Antiseizure Effects, in Neonatal Rats. Pharmaceutics 2018; 10:E281. [PMID: 30558371 PMCID: PMC6320943 DOI: 10.3390/pharmaceutics10040281] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/13/2018] [Accepted: 12/14/2018] [Indexed: 02/07/2023] Open
Abstract
Flupirtine, a nonopioid analgesic drug, is effective in treating neonatal seizures. However, its brain delivery and pharmacokinetics are unknown in neonatal mammals. The purpose of this study was to determine the pharmacokinetics of flupirtine and the formation of its active metabolite D-13223 in various tissues such as brain in neonate animals. On postnatal day 7, rat pups received 25 mg/kg of flupirtine intraperitoneally. Liver; heart; kidney; lung; spleen; retina; serum; and brain regions hippocampus, cortex, and the remaining brain (devoid of cerebellum) were harvested up to 24-h postdosing. An LC-MS/MS assay was developed to quantify flupirtine and D-13223. Flupirtine was delivered to all tissues assessed, with the highest area under the concentration vs. time curve (AUC0⁻24h) in liver (488 µg·h/g tissue) and the lowest in spleen (82 µg·h/g tissue). Flupirtine reached the brain, including the hippocampus and cortex, within 1 h of dosing and persisted at 24 h. Flupirtine AUC in various brain regions was approximately 195 µg·h/g tissue. The half-life of flupirtine in various tissues ranged from 3.1 to 5.2 h. D-13223 was formed in vivo and detected in all tissues assessed, with the concentrations being the highest in the liver. Incubation of isolated neonatal rat liver, heart, kidney, lung, spleen, whole eye, serum, or whole brain with flupirtine for 3 h at 37 °C formed D-13223 in all tissues, except serum. D-13223 formation was the highest in isolated liver tissue. Tissue partition coefficients based on isolated tissue uptake correlated well with in vivo tissue:serum drug exposure ratios. Thus, flupirtine reaches the target brain tissues from the systemic route in neonatal rats, and brain tissue forms the active metabolite D-13223.
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Affiliation(s)
- Madhoosudan A Patil
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
| | - Brock A Matter
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
| | - Yogendra H Raol
- Department of Pediatrics, Division of Neurology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.
| | - David W A Bourne
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
| | - Ryan A Kelley
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
| | - Uday B Kompella
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
- Colorado Center for Nanomedicine and Nanosafety, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
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Lawson K. Kv7 channels a potential therapeutic target in fibromyalgia: A hypothesis. World J Pharmacol 2018; 7:1-9. [DOI: 10.5497/wjp.v7.i1.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/05/2018] [Accepted: 10/13/2018] [Indexed: 02/06/2023] Open
Abstract
Fibromyalgia is characterized by the primary symptoms of persistent diffuse pain, fatigue, sleep disturbance and cognitive dysfunction. Persistent pain conditions, such as fibromyalgia, are often refractory to current available therapies. An involvement of K+ channels in the pathophysiology of fibromyalgia is emerging and supported by drug treatments for this condition exhibiting action at these molecular processes. K+ channels constitute potential novel target candidates for pain therapy offering peripheral and/or central actions. The Kv7 channel activators, flupirtine and retigabine, have exhibited pharmacological profiles compatible to the requirements needed for use as a therapeutic approach to fibromyalgia. Clinical trials to address the multidimensional challenges of fibromyalgia with flupirtine and retigabine will provide important insight to the role of K+ channels in this condition.
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Affiliation(s)
- Kim Lawson
- Department of Biosciences and Chemistry, Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield S1 1WB, United Kingdom
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Bonham LW, Evans DS, Liu Y, Cummings SR, Yaffe K, Yokoyama JS. Neurotransmitter Pathway Genes in Cognitive Decline During Aging: Evidence for GNG4 and KCNQ2 Genes. Am J Alzheimers Dis Other Demen 2018; 33:153-165. [PMID: 29338302 PMCID: PMC6209098 DOI: 10.1177/1533317517739384] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND/RATIONALE Experimental studies support the role of neurotransmitter genes in dementia risk, but human studies utilizing single variants in candidate genes have had limited success. METHODS We used the gene-based testing program Versatile Gene-based Association Study to assess whether aggregate variation across 6 neurotransmitter pathways influences risk of cognitive decline in 8159 cognitively normal elderly (≥65 years old) adults from 3 community-based cohorts. RESULTS Common genetic variation in GNG4 and KCNQ2 was associated with cognitive decline. In human brain tissue data sets, both GNG4 and KCNQ2 show higher expression in hippocampus relative to other brain regions; GNG4 expression decreases with advancing age. Both GNG4 and KCNQ2 show highest expression in fetal astrocytes. CONCLUSION Genetic variation analyses and gene expression data suggest that GNG4 and KCNQ2 may be associated with cognitive decline in normal aging. Gene-based testing of neurotransmitter pathways may confirm and reveal novel risk genes in future studies of healthy cognitive aging.
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Affiliation(s)
- Luke W. Bonham
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
| | - Daniel S. Evans
- California Pacific Medical Center Research Institute, San Francisco, CA, USA
| | - Yongmei Liu
- Department of Epidemiology and Prevention, Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Steven R. Cummings
- California Pacific Medical Center Research Institute, San Francisco, CA, USA
| | - Kristine Yaffe
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA
- Department of Veterans Affairs, San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA
- Department of Psychiatry, University of California, San Francisco, CA, USA
| | - Jennifer S. Yokoyama
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
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30
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Krasnykh LM, Rodina TA, Mel’nikov ES, Vasilenko GF, Smirnov VV, Sokolov AV, Arkhipov VV. Flupirtine Determination in Human Blood Plasma by HPLC with Mass-Spectrometric Detection and its Application to Pharmacokinetic Studies. Pharm Chem J 2018. [DOI: 10.1007/s11094-018-1752-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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31
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Kinarivala N, Patel R, Boustany RM, Al-Ahmad A, Trippier PC. Discovery of Aromatic Carbamates that Confer Neuroprotective Activity by Enhancing Autophagy and Inducing the Anti-Apoptotic Protein B-Cell Lymphoma 2 (Bcl-2). J Med Chem 2017; 60:9739-9756. [PMID: 29110485 DOI: 10.1021/acs.jmedchem.7b01199] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Neurodegenerative diseases share certain pathophysiological hallmarks that represent common targets for drug discovery. In particular, dysfunction of proteostasis and the resultant apoptotic death of neurons represent common pathways for pharmacological intervention. A library of aromatic carbamate derivatives based on the clinically available drug flupirtine was synthesized to determine a structure-activity relationship for neuroprotective activity. Several derivatives were identified that possess greater protective effect in human induced pluripotent stem cell-derived neurons, protecting up to 80% of neurons against etoposide-induced apoptosis at concentrations as low as 100 nM. The developed aromatic carbamates possess physicochemical properties desirable for CNS therapeutics. The primary known mechanisms of action of the parent scaffold are not responsible for the observed neuroprotective activity. Herein, we demonstrate that neuroprotective aromatic carbamates function to increase the Bcl-2/Bax ratio to an antiapoptotic state and activate autophagy through induction of beclin 1.
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Affiliation(s)
- Nihar Kinarivala
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center , Amarillo, Texas 79106, United States
| | - Ronak Patel
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center , Amarillo, Texas 79106, United States
| | - Rose-Mary Boustany
- Department of Biochemistry and Molecular Genetics, American University of Beirut Medical Center , Beirut 1107 2020, Lebanon
| | - Abraham Al-Ahmad
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center , Amarillo, Texas 79106, United States
| | - Paul C Trippier
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center , Amarillo, Texas 79106, United States.,Center for Chemical Biology, Department of Chemistry and Biochemistry, Texas Tech University , Lubbock, Texas 79409, United States
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Chinnaiyan S, Sarala N, Arun HS. A comparative study of efficacy and safety of flupirtine versus piroxicam in postoperative pain in patients undergoing lower limb surgery. J Pain Res 2017; 10:2471-2477. [PMID: 29081669 PMCID: PMC5652919 DOI: 10.2147/jpr.s144647] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Background Effective control of pain postoperatively is essential in providing enhanced patient care and a cost-effective hospital stay. Though many treatment modalities exist for postoperative pain management in orthopedic surgeries they are often accompanied by adverse effects. This study was carried out to assess the efficacy of flupirtine and piroxicam in postoperative pain reduction using visual analog scale (VAS) score. Materials and methods An open-label, parallel group, comparative study was conducted on patients undergoing lower limb orthopedic surgery, randomized into two groups of 38 patients each. They received either flupirtine 100 mg or piroxicam 20 mg 6 hours after surgery and then twice daily orally for 5 days. Pain was measured using VAS score, total pain relief score (TOTPAR24), and patient satisfaction score (PSS); the other scales used were behavioral pain assessment scale (BPAS) and functional activity score (FAS). Rescue medication used was tramadol 100 mg intravenously. WHO causality scale was used for assessing adverse effects. Descriptive and inferential statistics were used for assessment of various parameters. Results A total of 76 patients with mean ± standard deviation age of 35.08±10.3 years were recruited; 34 in the flupirtine and 37 in the piroxicam groups completed the study. Patients in both groups were comparable in baseline characteristics. Flupirtine and piroxicam reduced VAS score 48 hours postoperatively compared to baseline (p=0.006 and 0.001) and piroxicam produced significant reduction in pain at 8, 12, and 120 hours compared to flupirtine (p=0.028, 0.032, 0.021). TOTPAR24 and PSS at 24 hours were comparable between the treatments. BPAS scores at 24 hours were reduced significantly in patients receiving either drug (p=0.001). FAS improved at 72 hours in patients receiving piroxicam. Adverse effects were similar with both the medications. Conclusion Flupirtine and piroxicam reduced pain effectively but the onset of pain relief was earlier with piroxicam.
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Affiliation(s)
| | | | - Heddur Shanthappa Arun
- Department of Orthopaedics, Sri Devaraj Urs Medical College, Sri Devaraj Urs Academy of Higher Education and Research, Kolar, Karnataka, India
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Yan YY, Li CY, Zhou L, Ao LY, Fang WR, Li YM. Research progress of mechanisms and drug therapy for neuropathic pain. Life Sci 2017; 190:68-77. [PMID: 28964813 DOI: 10.1016/j.lfs.2017.09.033] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 09/09/2017] [Accepted: 09/25/2017] [Indexed: 12/13/2022]
Abstract
Neuropathic pain is maladaptive pain caused by injury or dysfunction in peripheral and central nervous system, and remains a worldwide thorny problem leading to decreases in physical and mental quality of people's life. Currently, drug therapy is the main treatment regimen for resolving pain, while effective drugs are still unmet in medical need, and commonly used drugs such as anticonvulsants and antidepressants often make patients experience adverse drug reactions like dizziness, somnolence, severe headache, and high blood pressure. Thus, in this review we overview the anatomical physiology, underlying mechanisms of neuropathic pain to provide a better understanding in the initiation, development, maintenance, and modulation of this pervasive disease, and inspire research in the unclear mechanisms as well as potential targets. Furthermore, we summarized the existing drug therapies and new compounds that have shown antalgic effects in laboratory studies to be helpful for rational regimens in clinical treatment and promotion in novel drug discovery.
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Affiliation(s)
- Yun-Yi Yan
- State Key Laboratory of Natural Medicines, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, PR China
| | - Cheng-Yuan Li
- State Key Laboratory of Natural Medicines, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, PR China
| | - Lin Zhou
- State Key Laboratory of Natural Medicines, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, PR China
| | - Lu-Yao Ao
- State Key Laboratory of Natural Medicines, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, PR China
| | - Wei-Rong Fang
- State Key Laboratory of Natural Medicines, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, PR China.
| | - Yun-Man Li
- State Key Laboratory of Natural Medicines, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, PR China.
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Sampath D, Valdez R, White AM, Raol YH. Anticonvulsant effect of flupirtine in an animal model of neonatal hypoxic-ischemic encephalopathy. Neuropharmacology 2017; 123:126-135. [PMID: 28587899 DOI: 10.1016/j.neuropharm.2017.06.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 05/07/2017] [Accepted: 06/02/2017] [Indexed: 12/20/2022]
Abstract
Research studies suggest that neonatal seizures, which are most commonly associated with hypoxic-ischemic injury, may contribute to brain injury and adverse neurologic outcome. Unfortunately, neonatal seizures are often resistant to treatment with current anticonvulsants. In the present study, we evaluated the efficacy of flupirtine, administered at clinically relevant time-points, for the treatment of neonatal seizures in an animal model of hypoxic-ischemic injury that closely replicates features of the human syndrome. We also compared the efficacy of flupirtine to that of phenobarbital, the current first-line drug for neonatal seizures. Flupirtine is a KCNQ potassium channel opener. KCNQ channels play an important role in controlling brain excitability during early development. In this study, hypoxic-ischemic injury was induced in neonatal rats, and synchronized video-EEG records were acquired at various time-points during the experiment to identify seizures. The results revealed that flupirtine, administered either 5 min after the first electroclinical seizure, or following completion of 2 h of hypoxia, i.e., during the immediate reperfusion period, reduced the number of rats with electroclinical seizures, and also the frequency and total duration of electroclinical seizures. Further, daily dosing of flupirtine decreased the seizure burden over 3 days following HI-induction, and modified the natural evolution of acute seizures. Moreover, compared to a therapeutic dose of phenobarbital, which was modestly effective against electroclinical seizures, flupirtine showed greater efficacy. Our results indicate that flupirtine is an extremely effective treatment for neonatal seizures in rats and provide evidence for a trial of this medication in newborn humans.
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Affiliation(s)
- Dayalan Sampath
- Department of Pediatrics, Division of Neurology, School of Medicine, Translational Epilepsy Research Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Robert Valdez
- Department of Pediatrics, Division of Neurology, School of Medicine, Translational Epilepsy Research Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Andrew M White
- Department of Pediatrics, Division of Neurology, School of Medicine, Translational Epilepsy Research Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Yogendra H Raol
- Department of Pediatrics, Division of Neurology, School of Medicine, Translational Epilepsy Research Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.
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35
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Lawson K. Emerging pharmacological strategies for the treatment of fibromyalgia. World J Pharmacol 2017; 6:1-10. [DOI: 10.5497/wjp.v6.i1.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Revised: 01/06/2017] [Accepted: 02/13/2017] [Indexed: 02/06/2023] Open
Abstract
Fibromyalgia (FM) has been described as a chronic clinical condition related to multisensory hypersensitivity presenting with a complex of symptoms dominated by chronic widespread pain associated with the existence of a range of co-morbidities, such as fatigue, sleep disturbance, cognitive impairment, anxiety and depression. Current treatments include drugs that target serotonin and noradrenaline levels within the central nervous system, e.g., tricyclic antidepressants, serotonin noradrenaline reuptake inhibitors, and voltage-gated calcium channel subunit ligands, e.g., gabapentin and pregabalin. Investigation of a range of novel targets, such as melatoninergic, cannabinoid, dopamine, NMDA, angiotensin, orexin and opioid receptors, and ion channels, in addition revisiting bioamine modulation and subunits has provided efficacy outcomes that improve the health status of patients with FM. Nevertheless, modest and limited efficacy is often observed reflecting the heterogeneity of FM with existence of subpopulations of patients, the contribution of peripheral and central components to the pathophysiology, and the extensive range of accompanying co-morbidities. The complexity and multidimensional nature of FM is emphasized by the diversity of pharmacological targets gaining interest. Clues to underlying mechanisms which offer themselves as novel and potential targets for new medications are being provided by advances in the understanding of the pathophysiology of FM.
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TAMH: A Useful In Vitro Model for Assessing Hepatotoxic Mechanisms. BIOMED RESEARCH INTERNATIONAL 2016; 2016:4780872. [PMID: 28074186 PMCID: PMC5198153 DOI: 10.1155/2016/4780872] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/10/2016] [Accepted: 11/24/2016] [Indexed: 02/07/2023]
Abstract
In vitro models for hepatotoxicity can be useful tools to predict in vivo responses. In this review, we discuss the use of the transforming growth factor-α transgenic mouse hepatocyte (TAMH) cell line, which is an attractive model to study drug-induced liver injury due to its ability to retain a stable phenotype and express drug-metabolizing enzymes. Hepatotoxicity involves damage to the liver and is often associated with chemical exposure. Since the liver is a major site for drug metabolism, drug-induced liver injury is a serious health concern for certain agents. At the molecular level, various mechanisms may protect or harm the liver during drug-induced hepatocellular injury including signaling pathways and endogenous factors (e.g., Bcl-2, GSH, Nrf2, or MAPK). The interplay between these and other pathways in the hepatocyte can change upon drug or drug metabolite exposure leading to intracellular stress and eventually cell death and liver injury. This review focuses on mechanistic studies investigating drug-induced toxicity in the TAMH line and how alterations to hepatotoxic mechanisms in this model relate to the in vivo situation. The agents discussed herein include acetaminophen (APAP), tetrafluoroethylcysteine (TFEC), flutamide, PD0325901, lapatinib, and flupirtine.
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Pilania M, Velladurai A, Tantak MP, Kumar D. Cu-Catalyzed Expeditious Synthesis of N-Benzylaminoheter-ocycles Using N-Tosylhydrazones and Aminoheteroarenes. ChemistrySelect 2016. [DOI: 10.1002/slct.201601734] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Meenakshi Pilania
- Department of Chemistry; Birla Institute of Technology and Science; Pilani-333031 Rajasthan India
| | - Arun Velladurai
- Department of Chemistry; Birla Institute of Technology and Science; Pilani-333031 Rajasthan India
| | - Mukund P. Tantak
- Department of Chemistry; Birla Institute of Technology and Science; Pilani-333031 Rajasthan India
| | - Dalip Kumar
- Department of Chemistry; Birla Institute of Technology and Science; Pilani-333031 Rajasthan India
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Effects of novel subtype selective M-current activators on spinal reflexes in vitro: Comparison with retigabine. Neuropharmacology 2016; 109:131-138. [DOI: 10.1016/j.neuropharm.2016.05.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 04/28/2016] [Accepted: 05/31/2016] [Indexed: 01/13/2023]
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Malik R, Mehta P, Srivastava S, Choudhary BS, Sharma M. Pharmacophore modeling, 3D-QSAR, and in silico ADME prediction of N-pyridyl and pyrimidine benzamides as potent antiepileptic agents. J Recept Signal Transduct Res 2016; 37:259-266. [PMID: 27607834 DOI: 10.1080/10799893.2016.1217883] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Biological mechanism attributing mutations in KCNQ2/Q3 results in benign familial neonatal epilepsy (BFNE), a rare form of epilepsy and thus neglected. It offers a potential target for antiepileptic drug discovery. In the present work, a pharmacophore-based 3D-QSAR model was generated for a series of N-pyridyl and pyrimidine benzamides possessing KCNQ2/Q3 opening activity. The pharmacophore model generated contains one hydrogen bond donor (D), one hydrophobic (H), and two aromatic rings (R). They are the crucial molecular write-up detailing predicted binding efficacy of high affinity and low affinity ligands for KCNQ2/Q3 opening activity. Furthermore, it has been validated by using a biological correlation between pharmacophore hypothesis-based 3D-QSAR variables and functional fingerprints of openers responsible for the receptor binding and also by docking of these benzamides into the validated homology model. Excellent statistical computational tools of QSAR model such as good correlation coefficient (R2 > 0.80), higher F value (F > 39), and excellent predictive power (Q2 > 0.7) with low standard deviation (SD <0.3) strongly suggest that the developed model could be used for prediction of antiepileptic activity of newer analogs. A preliminary pharmacokinetic profile of these derivatives was also performed on the basis of QikProp predictions.
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Affiliation(s)
- Ruchi Malik
- a Department of Pharmacy, School of Chemical Sciences and Pharmacy , Central University of Rajasthan , Kishangarh, Ajmer , Rajasthan , India
| | - Pakhuri Mehta
- a Department of Pharmacy, School of Chemical Sciences and Pharmacy , Central University of Rajasthan , Kishangarh, Ajmer , Rajasthan , India
| | - Shubham Srivastava
- a Department of Pharmacy, School of Chemical Sciences and Pharmacy , Central University of Rajasthan , Kishangarh, Ajmer , Rajasthan , India
| | - Bhanwar Singh Choudhary
- a Department of Pharmacy, School of Chemical Sciences and Pharmacy , Central University of Rajasthan , Kishangarh, Ajmer , Rajasthan , India
| | - Manish Sharma
- b School of Pharmacy , Maharishi Markandeshwar University , Sadopur, Ambala , Haryana , India
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Abstract
Supplemental Digital Content is Available in the Text. Combining electrophysiology and in vivo pain models, the concept that activation of peripheral KCNQ channels relieves the gout pain is demonstrated. Intense inflammatory pain caused by urate crystals in joints and other tissues is a major symptom of gout. Among therapy drugs that lower urate, benzbromarone (BBR), an inhibitor of urate transporters, is widely used because it is well tolerated and highly effective. We demonstrate that BBR is also an activator of voltage-gated KCNQ potassium channels. In cultured recombinant cells, BBR exhibited significant potentiation effects on KCNQ channels comparable to previously reported classical activators. In native dorsal root ganglion neurons, BBR effectively overcame the suppression of KCNQ currents, and the resultant neuronal hyperexcitability caused by inflammatory mediators, such as bradykinin (BK). Benzbromarone consistently attenuates BK-, formalin-, or monosodium urate–induced inflammatory pain in rat and mouse models. Notably, the analgesic effects of BBR are largely mediated through peripheral and not through central KCNQ channels, an observation supported both by pharmacokinetic studies and in vivo experiments. Moreover, multiple residues in the superficial part of the voltage sensing domain of KCNQ channels were identified critical for the potentiation activity of BBR by a molecular determinant investigation. Our data indicate that activation of peripheral KCNQ channels mediates the pain relief effects of BBR, potentially providing a new strategy for the development of more effective therapies for gout.
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Abstract
PURPOSE OF REVIEW Poor management of chronic pain remains a significant cause of misery with huge socioeconomic costs. Accumulating research in potassium (K+) channel physiology has uncovered several promising leads for the development of novel analgesics. RECENT FINDINGS We now recognize that certain K+ channel subunits are directly gated to pain-relevant stimuli (Kv1.1, K2P) whereas others are specifically modulated by inflammatory processes (Kv7, BKCA, K2P). Genetic analyses illustrate that K+ channel gene variation can predict pain sensitivity (KCNS1, GIRKs), risk for persistent pain (KCNS1, GIRKs, TRESK) and analgesic effectiveness (GIRK2). Importantly, preclinical studies confirm that K+ channel dysfunction can be a pain trigger in traumatic neuropathies (Kv9.1/Kv2.1, Kv7, Kv1.2) and migraine (TRESK). Finally, emerging data suggest that even pain in diabetes, bone cancer and autoimmune neuropathies may have K+ channel dysfunction constituents. SUMMARY There is a long-sought need for superior pharmacotherapy of pain syndromes. Although universal enhancement of K+ channel function in the periphery can decrease nociceptive excitability irrespective of the underlying cause, a more refined targeting of subunits with dominant nociceptive roles could yield highly efficacious treatments with fewer side-effects. The ongoing characterization of molecular interactions linking K+ channel dysfunction to pain is instrumental for identifying candidates with the most therapeutic potential.
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Currò D. The Modulation of Potassium Channels in the Smooth Muscle as a Therapeutic Strategy for Disorders of the Gastrointestinal Tract. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2016; 104:263-305. [PMID: 27038377 DOI: 10.1016/bs.apcsb.2015.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Alterations of smooth muscle contractility contribute to the pathophysiology of important functional gastrointestinal disorders (FGIDs) such as functional dyspepsia and irritable bowel syndrome. Consequently, drugs that decrease smooth muscle contractility are effective treatments for these diseases. Smooth muscle contraction is mainly triggered by Ca(2+) influx through voltage-dependent channels located in the plasma membrane. Thus, the modulation of the membrane potential results in the regulation of Ca(2+) influx and cytosolic levels. K(+) channels play fundamental roles in these processes. The open probability of K(+) channels increases in response to various stimuli, including membrane depolarization (voltage-gated K(+) [K(V)] channels) and the increase in cytosolic Ca(2+) levels (Ca(2+)-dependent K(+) [K(Ca)] channels). K(+) channel activation is mostly associated with outward K(+) currents that hyperpolarize the membrane and reduce cell excitability and contractility. In addition, some K(+) channels are open at the resting membrane potential values of the smooth muscle cells in some gut segments and contribute to set the resting membrane potential itself. The closure of these channels induces membrane depolarization and smooth muscle contraction. K(V)1.2, 1.5, 2.2, 4.3, 7.4 and 11.1, K(Ca)1.1 and 2.3, and inwardly rectifying type 6K(+) (K(ir)6) channels play the most important functional roles in the gastrointestinal smooth muscle. Activators of all these channels may theoretically relax the gastrointestinal smooth muscle and could therefore be promising new therapeutic options for FGID. The challenge of future drug research and development in this area will be to synthesize molecules selective for the channel assemblies expressed in the gastrointestinal smooth muscle.
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Affiliation(s)
- Diego Currò
- Institute of Pharmacology, School of Medicine, Catholic University of the Sacred Heart, Rome, Italy.
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De Vito V, Lebkowska-Wieruszewska B, Shaban A, Lisowski A, Kowaski CJ, Giorgi M. Pharmacokinetic profiles of the analgesic flupirtine in dogs after the administration of four pharmaceutical formulations. Vet Anaesth Analg 2015; 42:629-37. [DOI: 10.1111/vaa.12235] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 07/25/2014] [Indexed: 02/06/2023]
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Klinger F, Bajric M, Salzer I, Dorostkar MM, Khan D, Pollak DD, Kubista H, Boehm S, Koenig X. δ Subunit-containing GABAA receptors are preferred targets for the centrally acting analgesic flupirtine. Br J Pharmacol 2015. [PMID: 26211808 PMCID: PMC4621994 DOI: 10.1111/bph.13262] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Background and Purpose The Kv7 channel activator flupirtine is a clinical analgesic characterized as ‘selective neuronal potassium channel opener’. Flupirtine was found to exert comparable actions at GABAA receptors and Kv7 channels in neurons of pain pathways, but not in hippocampus. Experimental Approach Expression patterns of GABAA receptors were explored in immunoblots of rat dorsal root ganglia, dorsal horns and hippocampi using antibodies for 10 different subunits. Effects of flupirtine on recombinant and native GABAA receptors were investigated in patch clamp experiments and compared with the actions on Kv7 channels. Key Results Immunoblots pointed towards α2, α3, β3 and γ2 subunits as targets, but in all γ2‐containing receptors the effects of flupirtine were alike: leftward shift of GABA concentration‐response curves and diminished maximal amplitudes. After replacement of γ2S by δ, flupirtine increased maximal amplitudes. Currents through α1β2δ receptors were more enhanced than those through Kv7 channels. In hippocampal neurons, flupirtine prolonged inhibitory postsynaptic currents, left miniature inhibitory postsynaptic currents (mIPSCs) unaltered and increased bicuculline‐sensitive tonic currents; penicillin abolished mIPSCs, but not tonic currents; concentration‐response curves for GABA‐induced currents were shifted to the left by flupirtine without changes in maximal amplitudes; in the presence of penicillin, maximal amplitudes were increased; GABA‐induced currents in the presence of penicillin were more sensitive towards flupirtine than K+ currents. In dorsal horn neurons, currents evoked by the δ‐preferring agonist THIP (gaboxadol) were more sensitive towards flupirtine than K+ currents. Conclusions and Implications Flupirtine prefers δ‐containing GABAA receptors over γ‐containing ones and over Kv7 channels.
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Affiliation(s)
- Felicia Klinger
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Mirnes Bajric
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Isabella Salzer
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Mario M Dorostkar
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Deeba Khan
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Daniela D Pollak
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Helmut Kubista
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Stefan Boehm
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Xaver Koenig
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
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Janke E, Skripuletz T, Hillemacher T, Heberlein A. Flupirtine dependence and withdrawal syndrome. JOURNAL OF SUBSTANCE USE 2015. [DOI: 10.3109/14659891.2015.1029025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Barrett JM, Degenaar P, Sernagor E. Blockade of pathological retinal ganglion cell hyperactivity improves optogenetically evoked light responses in rd1 mice. Front Cell Neurosci 2015; 9:330. [PMID: 26379501 PMCID: PMC4548307 DOI: 10.3389/fncel.2015.00330] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/10/2015] [Indexed: 12/17/2022] Open
Abstract
Retinitis pigmentosa (RP) is a progressive retinal dystrophy that causes visual impairment and eventual blindness. Retinal prostheses are the best currently available vision-restoring treatment for RP, but only restore crude vision. One possible contributing factor to the poor quality of vision achieved with prosthetic devices is the pathological retinal ganglion cell (RGC) hyperactivity that occurs in photoreceptor dystrophic disorders. Gap junction blockade with meclofenamic acid (MFA) was recently shown to diminish RGC hyperactivity and improve the signal-to-noise ratio (SNR) of RGC responses to light flashes and electrical stimulation in the rd10 mouse model of RP. We sought to extend these results to spatiotemporally patterned optogenetic stimulation in the faster-degenerating rd1 model and compare the effectiveness of a number of drugs known to disrupt rd1 hyperactivity. We crossed rd1 mice with a transgenic mouse line expressing the light-sensitive cation channel channelrhodopsin2 (ChR2) in RGCs, allowing them to be stimulated directly using high-intensity blue light. We used 60-channel ITO multielectrode arrays to record ChR2-mediated RGC responses from wholemount, ex-vivo retinas to full-field and patterned stimuli before and after application of MFA, 18-β-glycyrrhetinic acid (18BGA, another gap junction blocker) or flupirtine (Flu, a Kv7 potassium channel opener). All three drugs decreased spontaneous RGC firing, but 18BGA and Flu also decreased the sensitivity of RGCs to optogenetic stimulation. Nevertheless, all three drugs improved the SNR of ChR2-mediated responses. MFA also made it easier to discern motion direction of a moving bar from RGC population responses. Our results support the hypothesis that reduction of pathological RGC spontaneous activity characteristic in retinal degenerative disorders may improve the quality of visual responses in retinal prostheses and they provide insights into how best to achieve this for optogenetic prostheses.
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Affiliation(s)
- John M Barrett
- Faculty of Medical Sciences, Institute of Neuroscience, Newcastle University Newcastle-upon-Tyne, UK
| | - Patrick Degenaar
- Faculty of Science, Agriculture and Engineering, School of Electrical and Electronic Engineering, Newcastle University Newcastle-upon-Tyne, UK
| | - Evelyne Sernagor
- Faculty of Medical Sciences, Institute of Neuroscience, Newcastle University Newcastle-upon-Tyne, UK
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Giorgi M, De Vito V, Poapolathep A, Rychshanova R, Sgorbini M, Owen H. Pharmacokinetics and disposition of flupirtine in the horse. Vet J 2015; 208:76-80. [PMID: 26681139 DOI: 10.1016/j.tvjl.2015.08.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Revised: 05/26/2015] [Accepted: 08/15/2015] [Indexed: 01/15/2023]
Abstract
Flupirtine (FLU) is a non-opioid analgesic drug, with no antipyretic or anti-inflammatory effects, used in the treatment of a wide range of pain states in human beings. It does not induce the side effects associated with the classical drugs used as pain relievers. The aim of this study was to evaluate the pharmacokinetic profiles of FLU after IV and PO administration in healthy horses. Six mixed breed adult mares were randomly assigned to two treatment groups using an open, single-dose, two-treatment, two-phase, paired, cross-over design (2 × 2 Latin-square). Group 1 (n = 3) received a single dose of 1 mg/kg of FLU injected IV into the jugular vein. Group 2 (n = 3) received FLU (5 mg/kg) via nasogastric tube. The animals then swapped groups after a 1-week wash-out period and the doses were repeated. Blood samples (5 mL) were collected at 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10, 24, 36 and 48 h and plasma was then analysed by a validated HPLC method. Some mild and transient adverse effects (that spontaneously resolved within 5 min) were observed in 2/6 animals after IV administration. No adverse effects were noticed in the PO administration group. After IV and PO administrations, FLU was detectable in plasma for up to 36 h. The mean elimination half-life was longer after PO (10.27 h) than after IV (3.02 h) administration. The oral bioavailability was 71.4 ± 33.1%. After compartmental simulation/modelling, an oral dose of 2.6 mg/kg was calculated to give Cmax and AUC values in horses similar to those reported in humans after a clinical dose administration with a theoretical FLU effective plasma concentration of 187 ng/mL. These findings may form the basis for further studies concerning this active ingredient in equine medicine.
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Affiliation(s)
- M Giorgi
- Department of Veterinary Sciences, University of Pisa, Via Livornese (lato monte), San Piero a Grado, Italy.
| | - V De Vito
- Department of Veterinary Sciences, University of Pisa, Via Livornese (lato monte), San Piero a Grado, Italy
| | - A Poapolathep
- Department of Veterinary Pharmacology, Faculty of Veterinary Medicine, University of Kasetsart, Bangkok, Thailand
| | - R Rychshanova
- Veterinary School, Kostanay State A. Baitursynov University, Kostanay, Kazakhstan
| | - M Sgorbini
- Department of Veterinary Sciences, University of Pisa, Via Livornese (lato monte), San Piero a Grado, Italy
| | - H Owen
- School of Veterinary Science, The University of Queensland, Gatton Campus, Gatton, Queensland 4343, Australia
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Lemmerhirt CJ, Rombach M, Bodtke A, Bednarski PJ, Link A. Oxidation potentials of N-modified derivatives of the analgesic flupirtine linked to potassium KV 7 channel opening activity but not hepatocyte toxicity. ChemMedChem 2014; 10:368-79. [PMID: 25392984 DOI: 10.1002/cmdc.201402442] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Indexed: 12/30/2022]
Abstract
Openers of neuronal voltage-gated potassium channels (KV ) are of interest as therapeutic agents for treating pain (flupirtine) and epilepsy (retigabine). In an effort to better understand the mechanisms of action and toxicity of flupirtine, we synthesized nine novel analogues with varying redox behavior. Flupirtine can be oxidatively metabolized into azaquinone diimines; thus, the oxidation potentials of flupirtine and its analogues were measured by cyclic voltammetry. KV 7.2/3 (KCNQ2/3) opening activity was determined by an established assay with HEK293 cells overexpressing these channels. A link was found between the oxidation potentials of the compounds and their EC50 values for potassium channel opening activity. On the other hand, no correlation was observed between oxidation potentials and cytotoxicity in cultures of transgenic mouse hepatocytes (TAMH). These results support the idea that oxidative metabolites of flupirtine contribute to the mechanism of action, similar to what was recently proposed for acetaminophen (paracetamol), but not to hepatotoxicity.
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Affiliation(s)
- Christian J Lemmerhirt
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Ernst Moritz Arndt University, Friedrich-Ludwig-Jahn-Str. 17, 17487 Greifswald (Germany)
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Mycobacterial toxin induces analgesia in buruli ulcer by targeting the angiotensin pathways. Cell 2014; 157:1565-76. [PMID: 24949969 DOI: 10.1016/j.cell.2014.04.040] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 04/01/2014] [Accepted: 04/24/2014] [Indexed: 01/09/2023]
Abstract
Mycobacterium ulcerans, the etiological agent of Buruli ulcer, causes extensive skin lesions, which despite their severity are not accompanied by pain. It was previously thought that this remarkable analgesia is ensured by direct nerve cell destruction. We demonstrate here that M. ulcerans-induced hypoesthesia is instead achieved through a specific neurological pathway triggered by the secreted mycobacterial polyketide mycolactone. We decipher this pathway at the molecular level, showing that mycolactone elicits signaling through type 2 angiotensin II receptors (AT2Rs), leading to potassium-dependent hyperpolarization of neurons. We further validate the physiological relevance of this mechanism with in vivo studies of pain sensitivity in mice infected with M. ulcerans, following the disruption of the identified pathway. Our findings shed new light on molecular mechanisms evolved by natural systems for the induction of very effective analgesia, opening up the prospect of new families of analgesics derived from such systems.
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