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Cho HJ, Chung DK, Lee HH. Mefloquine-induced conformational shift in Cx36 N-terminal helix leading to channel closure mediated by lipid bilayer. Nat Commun 2024; 15:9223. [PMID: 39455592 PMCID: PMC11512059 DOI: 10.1038/s41467-024-53587-6] [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: 04/09/2024] [Accepted: 10/15/2024] [Indexed: 10/28/2024] Open
Abstract
Connexin 36 (Cx36) forms interneuronal gap junctions, establishing electrical synapses for rapid synaptic transmission. In disease conditions, inhibiting Cx36 gap junction channels (GJCs) is beneficial, as it prevents abnormal synchronous neuronal firing and apoptotic signal propagation, mitigating seizures and progressive cell death. Here, we present cryo-electron microscopy structures of human Cx36 GJC in complex with known channel inhibitors, such as mefloquine, arachidonic acid, and 1-hexanol. Notably, these inhibitors competitively bind to the binding pocket of the N-terminal helices (NTH), inducing a conformational shift from the pore-lining NTH (PLN) state to the flexible NTH (FN) state. This leads to the obstruction of the channel pore by flat double-layer densities of lipids. These studies elucidate the molecular mechanisms of how Cx36 GJC can be modulated by inhibitors, providing valuable insights into potential therapeutic applications.
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Affiliation(s)
- Hwa-Jin Cho
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, 08826, Korea
| | - Dong Kyu Chung
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, 08826, Korea
| | - Hyung Ho Lee
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, 08826, Korea.
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2
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Autier B, Verger A, Plaisse C, Manuel C, Chollet-Krugler M, Preza M, Lundstroem-Stadelmann B, Amela-Cortes M, Aninat C, Samson M, Brandhonneur N, Dion S. PLGA-PEG-COOH nanoparticles are efficient systems for delivery of mefloquine to Echinococcus multilocularis metacestodes. Exp Parasitol 2024; 265:108811. [PMID: 39111383 DOI: 10.1016/j.exppara.2024.108811] [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: 04/05/2024] [Revised: 06/10/2024] [Accepted: 08/05/2024] [Indexed: 08/11/2024]
Abstract
Alveolar echinococcosis (AE) is a severe disease caused by the infection with the larval stage of Echinococcus multilocularis, the metacestode. As there is no actual curative drug therapy, recommendations to manage AE patients are based on radical surgery and prophylactic administration of albendazole or mebendazole during 2 years to prevent relapses. There is an urgent need for new therapeutic strategies for the management of AE, as the drugs in use are only parasitostatic, and can induce toxicity. This study aimed at developing a drug delivery system for mefloquine, an antiparasitic compound which is highly active against E. multilocularis in vitro and in experimentally infected mice. We formulated mefloquine-loaded PLGA-PEG-COOH (poly-(lactic-co-glycolic acid)) nanoparticles that exhibit stable physical properties and mefloquine content. These nanoparticles crossed the outer acellular laminated layer of metacestodes in vitro and delivered their content to the inner germinal layer within less than 5 min. The in vitro anti-echinococcal activity of mefloquine was not altered during the formulation process. However, toxicity against hepatocytes was not reduced when compared to free mefloquine. Altogether, this study shows that mefloquine-loaded PLGA-PEG-COOH nanoparticles are promising candidates for drug delivery during AE treatment. However, strategies for direct parasite-specific targeting of these particles should be developed.
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Affiliation(s)
- Brice Autier
- IRSET (UMR_S 1085), INSERM (Institut de Recherche en Santé, Environnement et Travail), EHESP, CHU Rennes, University of Rennes, Rennes, France
| | - Alexis Verger
- CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, Univ Rennes, F-35000, Rennes, France
| | - Charleen Plaisse
- IRSET (UMR_S 1085), INSERM (Institut de Recherche en Santé, Environnement et Travail), EHESP, University of Rennes, Rennes, France
| | - Christelle Manuel
- IRSET (UMR_S 1085), INSERM (Institut de Recherche en Santé, Environnement et Travail), EHESP, University of Rennes, Rennes, France
| | - Marylène Chollet-Krugler
- CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, Univ Rennes, F-35000, Rennes, France
| | - Matias Preza
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Britta Lundstroem-Stadelmann
- Institute of Parasitology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland; Multidisciplinary Center of Infectious Diseases, University of Bern, Berne, Switzerland
| | - Marian Amela-Cortes
- CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, Univ Rennes, F-35000, Rennes, France
| | - Caroline Aninat
- INSERM, Université Rennes, INRAE, Institut NuMeCan, Nutrition, Metabolisms and Cancer, F-35000, Rennes, France
| | - Michel Samson
- IRSET (UMR_S 1085), INSERM (Institut de Recherche en Santé, Environnement et Travail), EHESP, University of Rennes, Rennes, France
| | - Nolwenn Brandhonneur
- CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, Univ Rennes, F-35000, Rennes, France
| | - Sarah Dion
- IRSET (UMR_S 1085), INSERM (Institut de Recherche en Santé, Environnement et Travail), EHESP, University of Rennes, Rennes, France.
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Shao M, Yu H, Santhakumar V, Yu J. Antiepileptogenic and neuroprotective effect of mefloquine after experimental status epilepticus. Epilepsy Res 2023; 198:107257. [PMID: 37989006 DOI: 10.1016/j.eplepsyres.2023.107257] [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: 08/04/2023] [Revised: 10/30/2023] [Accepted: 11/06/2023] [Indexed: 11/23/2023]
Abstract
Acquired temporal lobe epilepsy (TLE) characterized by spontaneous recurrent seizures (SRS) and hippocampal inhibitory neuron dysfunction is often refractory to current therapies. Gap junctional or electrical coupling between inhibitory neurons has been proposed to facilitate network synchrony and intercellular molecular exchange suggesting a role in both seizures and neurodegeneration. While gap junction blockers can limit acute seizures, whether blocking neuronal gap junctions can modify development of chronic epilepsy has not been examined. This study examined whether mefloquine, a selective blocker of Connexin 36 gap junctions which are well characterized in inhibitory neurons, can limit epileptogenesis and related cellular and behavioral pathology in a model of acquired TLE. A single, systemic dose of mefloquine administered early after pilocarpine-induced status epilepticus (SE) in rat reduced both development of SRS and behavioral co-morbidities. Immunostaining for interneuron subtypes identified that mefloquine treatment likely reduced delayed inhibitory neuronal loss after SE. Uniquely, parvalbumin expressing neurons in the hippocampal dentate gyrus appeared relatively resistant to early cell loss after SE. Functionally, whole cell patch clamp recordings revealed that mefloquine treatment preserved inhibitory synaptic drive to projection neurons one week and one month after SE. These results demonstrate that mefloquine, a drug already approved for malaria prophylaxis, is potentially antiepileptogenic and can protect against progressive interneuron loss and behavioral co-morbidities of epilepsy.
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Affiliation(s)
- Mingting Shao
- Department of Neurosurgery, the First Affiliated Hospital of Bengbu Medical College, Bengbu, China; Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Hang Yu
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Vijayalakshmi Santhakumar
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Jiandong Yu
- Department of Neurosurgery, the First Affiliated Hospital of Bengbu Medical College, Bengbu, China.
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Weiland AS. Recent Advances in Imported Malaria Pathogenesis, Diagnosis, and Management. CURRENT EMERGENCY AND HOSPITAL MEDICINE REPORTS 2023; 11:49-57. [PMID: 37213266 PMCID: PMC10091340 DOI: 10.1007/s40138-023-00264-5] [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] [Accepted: 03/28/2023] [Indexed: 05/23/2023]
Abstract
Purpose of Review Malaria is an important human parasitic disease affecting the population of tropical, subtropical regions as well as travelers to these areas.The purpose of this article is to provide clinicians practicing in non-endemic areas with a comprehensive overview of the recent data on microbiologic and pathophysiologic features of five Plasmodium parasites, clinical presentation of uncomplicated and severe cases, modern diagnostic methods, and treatment of malaria. Recent Findings Employment of robust surveillance programs, rapid diagnostic tests, highly active artemisinin-based therapy, and the first malaria vaccine have led to decline in malaria incidence; however, emerging drug resistance, disruptions due to the COVID-19 pandemic, and other socio-economic factors have stalled the progress. Summary Clinicians practicing in non-endemic areas such as the United States should consider a diagnosis of malaria in returning travelers presenting with fever, utilize rapid diagnostic tests if available at their practice locations in addition to microscopy, and timely initiate guideline-directed management as delays in treatment can lead to poor clinical outcomes.
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Affiliation(s)
- Anastasia S. Weiland
- Department of Medicine, Case Western Reserve University/University Hospitals Cleveland Medical Center, Cleveland, OH USA
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Yue Z, Hu B, Chen Z, Zheng G, Wang Y, Yang C, Cao P, Wu X, Liang L, Zang F, Wang J, Li J, Zhang T, Wu J, Chen H. Continuous release of mefloquine featured in electrospun fiber membranes alleviates epidural fibrosis and aids in sensory neurological function after lumbar laminectomy. Mater Today Bio 2022; 17:100469. [PMID: 36340590 PMCID: PMC9633751 DOI: 10.1016/j.mtbio.2022.100469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/11/2022] [Accepted: 10/18/2022] [Indexed: 11/05/2022] Open
Abstract
Recurrent low back pain after spinal surgeries, such as lumbar laminectomy, is a major complication of excessive epidural fibrosis. Although multiple preclinical and clinical methods have been aimed at ameliorating epidural fibrosis, their safety and efficacy remain largely unclear. Single implanted electrospun fibrous membranes provide physical barriers that can decrease tissue fibrosis after surgery; however, they also trigger local inflammation due to the implantation of a foreign body, thus subsequently attenuating their anti-fibrosis properties. Here, we designed a strategy that permits easy incorporation of mefloquine into polylactic acid membranes, and stable long-term mefloquine release, to potentially improve anti-fibrosis effects and relieve or prevent low back pain. The electrospun fibrous membranes grafted with mefloquine showed a well-controlled early temporary peak release, and secondary drug release occurred smoothly over several weeks. Histopathological and histomorphometric results indicated that the drug-loaded membranes had excellent anti-fibrosis effects after laminectomy in rats. Inflammation and neovascularization at the surgical site indicated that the mefloquine-grafted electrospun fibrous membranes provided sustained anti-inflammatory outcomes while effectively alleviating associated neuropathic pain hypersensitivity. In summary, our study indicated that polylactic acid-mefloquine grafted electrospun fibrous membranes may be a potential local agent to mitigate epidural fibrosis and support sensory neurological function after laminectomy, thereby potentially improving patients' postoperative outcomes.
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Affiliation(s)
- Zhihao Yue
- Spine Center, Department of Orthopedics, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Bo Hu
- Spine Center, Department of Orthopedics, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Zhe Chen
- Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, College of Biological Science and Medical Engineering, Donghua University, Shanghai, China
| | - Genjiang Zheng
- Spine Center, Department of Orthopedics, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Yunhao Wang
- Spine Center, Department of Orthopedics, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Chen Yang
- Spine Center, Department of Orthopedics, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Peng Cao
- Spine Center, Department of Orthopedics, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Xiaodong Wu
- Spine Center, Department of Orthopedics, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Lei Liang
- Spine Center, Department of Orthopedics, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Fazhi Zang
- Spine Center, Department of Orthopedics, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Jianxi Wang
- Spine Center, Department of Orthopedics, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Jing Li
- Spine Center, Department of Orthopedics, Changzheng Hospital, Naval Medical University, Shanghai, China
- Department of Bioinformatics, Center for Translational Medicine, Naval Medical University, Shanghai, 200433, China
| | - Tao Zhang
- Department of Orthopedic Surgery, Shanghai Sixth People's Hospital, 200030, Shanghai, China
| | - Jinglei Wu
- Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, College of Biological Science and Medical Engineering, Donghua University, Shanghai, China
| | - Huajiang Chen
- Spine Center, Department of Orthopedics, Changzheng Hospital, Naval Medical University, Shanghai, China
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Jandova J, Park SL, Corenblum MJ, Madhavan L, Snell JA, Rounds L, Wondrak GT. Mefloquine induces ER stress and apoptosis in BRAFi-resistant A375-BRAF V600E /NRAS Q61K malignant melanoma cells targeting intracranial tumors in a bioluminescent murine model. Mol Carcinog 2022; 61:603-614. [PMID: 35417045 PMCID: PMC9133119 DOI: 10.1002/mc.23407] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 03/15/2022] [Accepted: 03/27/2022] [Indexed: 02/03/2023]
Abstract
Molecularly targeted therapeutics have revolutionized the treatment of BRAFV600E -driven malignant melanoma, but the rapid development of resistance to BRAF kinase inhibitors (BRAFi) presents a significant obstacle. The use of clinical antimalarials for the investigational treatment of malignant melanoma has shown only moderate promise, attributed mostly to inhibition of lysosomal-autophagic adaptations of cancer cells, but identification of specific antimalarials displaying single-agent antimelanoma activity has remained elusive. Here, we have screened a focused library of clinically used artemisinin-combination therapeutic (ACT) antimalarials for the apoptotic elimination of cultured malignant melanoma cell lines, also examining feasibility of overcoming BRAFi-resistance comparing isogenic melanoma cells that differ only by NRAS mutational status (BRAFi-sensitive A375-BRAFV600E /NRASQ61 vs. BRAFi-resistant A375-BRAFV600E /NRASQ61K ). Among ACT antimalarials tested, mefloquine (MQ) was the only apoptogenic agent causing melanoma cell death at low micromolar concentrations. Comparative gene expression-array analysis (A375-BRAFV600E /NRASQ61 vs. A375-BRAFV600E /NRASQ61K ) revealed that MQ is a dual inducer of endoplasmic reticulum (ER) and redox stress responses that precede MQ-induced loss of viability. ER-trackerTM DPX fluorescence imaging and electron microscopy indicated ER swelling, accompanied by rapid induction of ER stress signaling (phospho-eIF2α, XBP-1s, ATF4). Fluo-4 AM-fluorescence indicated the occurrence of cytosolic calcium overload observable within seconds of MQ exposure. In a bioluminescent murine model employing intracranial injection of A375-Luc2 (BRAFV600E /NRASQ61K ) cells, an oral MQ regimen efficiently antagonized brain tumor growth. Taken together, these data suggest that the clinical antimalarial MQ may be a valid candidate for drug repurposing aiming at chemotherapeutic elimination of malignant melanoma cells, even if metastasized to the brain and BRAFi-resistant.
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Affiliation(s)
- Jana Jandova
- Department of Pharmacology and Toxicology, RK Coit College of Pharmacy & UA Cancer Center, University of Arizona, Tucson, Arizona, USA
| | - Sophia L. Park
- Department of Pharmacology and Toxicology, RK Coit College of Pharmacy & UA Cancer Center, University of Arizona, Tucson, Arizona, USA
| | - Mandi J. Corenblum
- Department of Neurology, Evelyn F McKnight Brain Institute and BIO5 Institute, University of Arizona, Tucson, Arizona, USA
| | - Lalitha Madhavan
- Department of Neurology, Evelyn F McKnight Brain Institute and BIO5 Institute, University of Arizona, Tucson, Arizona, USA
| | - Jeremy A. Snell
- Department of Pharmacology and Toxicology, RK Coit College of Pharmacy & UA Cancer Center, University of Arizona, Tucson, Arizona, USA
| | - Liliana Rounds
- Department of Pharmacology and Toxicology, RK Coit College of Pharmacy & UA Cancer Center, University of Arizona, Tucson, Arizona, USA
| | - Georg T. Wondrak
- Department of Pharmacology and Toxicology, RK Coit College of Pharmacy & UA Cancer Center, University of Arizona, Tucson, Arizona, USA
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Ahmad SS, Rahi M, Ranjan V, Sharma A. Mefloquine as a prophylaxis for malaria needs to be revisited. Int J Parasitol Drugs Drug Resist 2021; 17:23-26. [PMID: 34339933 PMCID: PMC8342532 DOI: 10.1016/j.ijpddr.2021.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/17/2021] [Accepted: 06/21/2021] [Indexed: 10/26/2022]
Abstract
According to WHO, 2019 witnessed 229 million cases of malaria globally, of which Africa accounted for 94% of cases. Early diagnosis and treatment are the basis of malaria management, and the need for good chemoprophylaxis especially for people travelling to endemic areas is vital. There are a number of drug options available for the prophylaxis of malaria, mefloquine being one of the drugs used. Mefloquine has been around from the 1970s, and was developed in the United States keeping in mind the soldiers that were being deployed to areas where chloroquine resistant strains of Plasmodium were discovered. Mefloquine was preferred for its once a week dosage. Within a decade of its introduction, reports of the side effects associated with its long-term use surfaced. Mefloquine is now reported to cause a myriad of neuropsychiatric side effects including anxiety, sleep disturbance, depression, dizziness and frank psychosis, especially in patients with pre-existing psychiatric disorders. Many countries like the United States and the United Kingdom have updated their drug boxes to include the warning of these potential neuropsychiatric effects. This paper reviews the side effects of mefloquine and why there is a need to revisit its use in Indian drug policy.
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Affiliation(s)
| | - Manju Rahi
- Indian Council of Medical Research, New Delhi, India
| | - Vikash Ranjan
- ICMR-National Institute of Malaria Research, New Delhi, India
| | - Amit Sharma
- ICMR-National Institute of Malaria Research, New Delhi, India; International Centre of Genetic Engineering and Biotechnology, New Delhi, India.
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