1
|
Stroffolini G, Lupia T, Gaviraghi A, Venuti F, Cinnirella G, Gori A, Spotti M, Blasi F, Codecasa L, Calcagno A, Aliberti S. Prescription habits and drugs accessibility for the treatment of non-tuberculous mycobacteria infections in Italy: a multicentric survey from the IRENE study group. Infection 2025; 53:383-392. [PMID: 39302627 PMCID: PMC11825620 DOI: 10.1007/s15010-024-02390-y] [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: 02/14/2024] [Accepted: 08/31/2024] [Indexed: 09/22/2024]
Abstract
PURPOSE Non-tuberculous mycobacteria (NTM) account for high clinical burden, and treatment can be challenging. Moreover, accessibility of NTM medications varies across centers. These challenges may lead to unplanned therapeutic changes, discontinuations, potentially affecting patient outcomes. Aim of this survey was to evaluate the accessibility of NTM-targeting drugs in Italy (with a particular focus on clofazimine) in centers associated with the IRENE Registry, a collaborative network of healthcare professionals. METHODS A cross-sectional, internet-based, questionnaire-survey on the use and availability of clofazimineand other NTM-targeting drugs was sent to 88 principal investigators of the IRENE network in Italyin 2020. The questionnaires were designed with closed-ended and open-ended questions and distributed using the SurveyMonkey® platform. RESULTS The surveys underscore the more frequent involvement of pulmonologists (42%) and infectious disease specialists (34%) in NTM treating strategies. Respondents were distributed across 18 out of20 Italian regions, with a significant concentration in the north, encompassing university hospitalsand outpatient clinics. Molecular testing is available in 40% of the involved centers, while phenotypic in 30% of the centers. Centers have a multidisciplinary team and an appointed pharmacy service for NTM drugs distribution in 10 and 75% of the cases, respectively. Substantial variability was observed in drug availability and accessibility, drug regimen composition, and drug dosage, particularly for medications like clofazimine. CONCLUSIONS This study shows the high heterogeneity of anti-NTM drug availability in Italy and prompts toward a harmonization in antibiotic prescription and access; it also emphasizes the challenges in determining the optimal therapeutic strategies for treating NTM-infections.
Collapse
Affiliation(s)
- Giacomo Stroffolini
- Department of Infectious-Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Via Don Angelo Sempreboni 5, Negrar, Verona, Italy.
| | - Tommaso Lupia
- Unit of Infectious Diseases, Cardinal Massaia, 14100, Asti, Italy
- Department of Medical Sciences, Infectious Diseases, University of Turin, 10126, Turin, Italy
| | - Alberto Gaviraghi
- Department of Infectious-Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Via Don Angelo Sempreboni 5, Negrar, Verona, Italy
| | - Francesco Venuti
- Department of Medical Sciences, Infectious Diseases, University of Turin, 10126, Turin, Italy
| | | | - Andrea Gori
- Department of Pathophysiology and Transplantation, University of Milan, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Maura Spotti
- Department of Pathophysiology and Transplantation, University of Milan, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Francesco Blasi
- Department of Pathophysiology and Transplantation, University of Milan, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Luigi Codecasa
- Regional TB Reference Centre, Istituto Villa Marelli, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
| | - Andrea Calcagno
- Department of Medical Sciences, Infectious Diseases, University of Turin, 10126, Turin, Italy.
| | - Stefano Aliberti
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072, Milan, Italy
- IRCCS Humanitas Research Hospital, Respiratory Unit, Via Manzoni 56, Rozzano, 20089, Milan, Italy
| |
Collapse
|
2
|
Mmakola K, Balmith M, Steel H, Said M, Potjo M, van der Mescht M, Hlatshwayo N, Meyer P, Tintinger G, Anderson R, Cholo M. Sodium, Potassium-Adenosine Triphosphatase as a Potential Target of the Anti-Tuberculosis Agents, Clofazimine and Bedaquiline. Int J Mol Sci 2024; 25:13022. [PMID: 39684733 DOI: 10.3390/ijms252313022] [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: 09/16/2024] [Revised: 11/26/2024] [Accepted: 11/27/2024] [Indexed: 12/18/2024] Open
Abstract
Multidrug-resistant tuberculosis (MDR-TB) patients are treated with a standardised, short World Health Organization (WHO) regimen which includes clofazimine (CFZ) and bedaquiline (BDQ) antibiotics. These two antibiotics lead to the development of QT prolongation in patients, inhibiting potassium (K+) uptake by targeting the voltage-gated K+ (Kv)11.1 (hERG) channel of the cardiomyocytes (CMs). However, the involvement of these antibiotics to regulate other K+ transporters of the CMs, as potential mechanisms of QT prolongation, has not been explored. This study determined the effects of CFZ and BDQ on sodium, potassium-adenosine triphosphatase (Na+,K+-ATPase) activity of CMs using rat cardiomyocytes (RCMs). These cells were treated with varying concentrations of CFZ and BDQ individually and in combination (1.25-5 mg/L). Thereafter, Na+,K+-ATPase activity was determined, followed by intracellular adenosine triphosphate (ATP) quantification and cellular viability determination. Furthermore, molecular docking of antibiotics with Na+,K+-ATPase was determined. Both antibiotics demonstrated dose-response inhibition of Na+,K+-ATPase activity of the RCMs. The greatest inhibition was demonstrated by combinations of CFZ and BDQ, followed by BDQ alone and, lastly, CFZ. Neither antibiotic, either individually or in combination, demonstrated cytotoxicity. Molecular docking revealed an interaction of both antibiotics with Na+,K+-ATPase, with BDQ showing higher protein-binding affinity than CFZ. The inhibitory effects of CFZ and BDQ, individually and in combination, on the activity of Na+,K+-ATPase pump of the RCMs highlight the existence of additional mechanisms of QT prolongation by these antibiotics.
Collapse
Affiliation(s)
- Khomotso Mmakola
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa
| | - Marissa Balmith
- Department of Pharmacology, Faculty of Health Sciences, University of Pretoria, Pretoria 0084, South Africa
| | - Helen Steel
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa
| | - Mohamed Said
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa
- Department of Medical Microbiology, Tshwane Academic Division, National Health Laboratory Services, Pretoria 0001, South Africa
| | - Moliehi Potjo
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa
- Department of Immunology, Tshwane Academic Division, National Health Laboratory Services, Pretoria 0002, South Africa
| | - Mieke van der Mescht
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa
| | - Nomsa Hlatshwayo
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa
- Department of Immunology, Tshwane Academic Division, National Health Laboratory Services, Pretoria 0002, South Africa
| | - Pieter Meyer
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa
- Department of Immunology, Tshwane Academic Division, National Health Laboratory Services, Pretoria 0002, South Africa
| | - Gregory Tintinger
- Department of Internal Medicine, Steve Biko Academic Hospital, Faculty of Health Sciences, University of Pretoria, Pretoria 0002, South Africa
| | - Ronald Anderson
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa
- Clinical and Translational Research Unit of the Rosebank, Oncology Centre, Johannesburg 2196, South Africa
| | - Moloko Cholo
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa
- Basic and Translational Research Unit, Nuclear Medicine Research Infrastructure, Steve Biko Academic Hospital, Pretoria 0001, South Africa
| |
Collapse
|
3
|
Calcagno A, Coppola N, Sarmati L, Tadolini M, Parrella R, Matteelli A, Riccardi N, Trezzi M, Di Biagio A, Pirriatore V, Russo A, Gualano G, Pontali E, Surace L, Falbo E, Mencarini J, Palmieri F, Gori A, Schiuma M, Lapadula G, Goletti D. Drugs for treating infections caused by non-tubercular mycobacteria: a narrative review from the study group on mycobacteria of the Italian Society of Infectious Diseases and Tropical Medicine. Infection 2024; 52:737-765. [PMID: 38329686 PMCID: PMC11142973 DOI: 10.1007/s15010-024-02183-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 01/12/2024] [Indexed: 02/09/2024]
Abstract
BACKGROUND Non-tuberculous mycobacteria (NTM) are generally free-living organism, widely distributed in the environment, with sporadic potential to infect. In recent years, there has been a significant increase in the global incidence of NTM-related disease, spanning across all continents and an increased mortality after the diagnosis has been reported. The decisions on whether to treat or not and which drugs to use are complex and require a multidisciplinary approach as well as patients' involvement in the decision process. METHODS AND RESULTS This review aims at describing the drugs used for treating NTM-associated diseases emphasizing the efficacy, tolerability, optimization strategies as well as possible drugs that might be used in case of intolerance or resistance. We also reviewed data on newer compounds highlighting the lack of randomised clinical trials for many drugs but also encouraging preliminary data for others. We also focused on non-pharmacological interventions that need to be adopted during care of individuals with NTM-associated diseases CONCLUSIONS: Despite insufficient efficacy and poor tolerability this review emphasizes the improvement in patients' care and the needs for future studies in the field of anti-NTM treatments.
Collapse
Affiliation(s)
- A Calcagno
- Unit of Infectious Diseases, Department of Medical Sciences, University of Turin, Turin, Italy.
- Stop TB Italy, Milan, Italy.
| | - N Coppola
- Infectious Diseases Unit, Section of Infectious Diseases, Department of Mental Health and Public Medicine, University of Campania Luigi Vanvitelli, Naples, Italy
| | - L Sarmati
- Department of System Medicine, Tor Vergata University and Infectious Disease Clinic, Policlinico Tor Vergata, Rome, Italy
| | - M Tadolini
- Stop TB Italy, Milan, Italy
- Infectious Diseases Unit, IRCCS Azienda Ospedaliero-Universitaria Di Bologna, Bologna, Italy
- Department of Medical and Surgical Sciences, Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - R Parrella
- Stop TB Italy, Milan, Italy
- Respiratory Infectious Diseases Unit, Cotugno Hospital, A. O. R. N. dei Colli, Naples, Italy
| | - A Matteelli
- Institute of Infectious and Tropical Diseases, WHO Collaborating Centre for TB Prevention, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - N Riccardi
- Stop TB Italy, Milan, Italy
- Infectious Diseases Unit, Department of Clinical and Experimental Medicine, Azienda Ospedaliero Universitaria Pisana, University of Pisa, Pisa, Italy
| | - M Trezzi
- Stop TB Italy, Milan, Italy
- Infectious and Tropical Diseases Unit, Department of Medical Sciences, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
| | - A Di Biagio
- Infectious Diseases Unit, San Martino Policlinico Hospital-IRCCS for Oncology and Neurosciences, Genoa, Italy
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
| | - V Pirriatore
- Stop TB Italy, Milan, Italy
- Unit of Infectious Diseases, "DivisioneA", Ospedale Amedeo di Savoia, ASL CIttà di Torino, Turin, Italy
| | - A Russo
- Infectious Diseases Unit, Section of Infectious Diseases, Department of Mental Health and Public Medicine, University of Campania Luigi Vanvitelli, Naples, Italy
| | - G Gualano
- Stop TB Italy, Milan, Italy
- Respiratory Infectious Diseases Unit, National Institute for Infectious Diseases Lazzaro Spallanzani-IRCCS, Rome, Italy
| | - E Pontali
- Department of Infectious Diseases, Galliera Hospital, Genoa, Italy
| | - L Surace
- Stop TB Italy, Milan, Italy
- Dipartimento Di Prevenzione, Azienda Sanitaria Provinciale di Catanzaro, Centro di Medicina del Viaggiatore e delle Migrazioni, P. O. Giovanni Paolo II, Lamezia Terme, CZ, Italy
| | - E Falbo
- Stop TB Italy, Milan, Italy
- Dipartimento Di Prevenzione, Azienda Sanitaria Provinciale di Catanzaro, Centro di Medicina del Viaggiatore e delle Migrazioni, P. O. Giovanni Paolo II, Lamezia Terme, CZ, Italy
| | - J Mencarini
- Infectious and Tropical Diseases Unit, Careggi University Hospital, Florence, Italy
| | - F Palmieri
- Respiratory Infectious Diseases Unit, National Institute for Infectious Diseases Lazzaro Spallanzani-IRCCS, Rome, Italy
| | - A Gori
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, ASST Fatebenefratelli Sacco-Ospedale Luigi Sacco-Polo Universitario and Università Degli Studi di Milano, Milano, Italy
| | - M Schiuma
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, ASST Fatebenefratelli Sacco-Ospedale Luigi Sacco-Polo Universitario and Università Degli Studi di Milano, Milano, Italy
| | - G Lapadula
- Infectious Diseases Unit, Fondazione IRCCS San Gerardo dei Tintori, University of Milano-Bicocca, Monza, Italy
| | - D Goletti
- Stop TB Italy, Milan, Italy
- Translational Research Unit, Epidemiology Department, National Institute for Infectious Diseases-IRCCS L. Spallanzani, Rome, Italy
| |
Collapse
|
4
|
Huang X, Lowrie DB, Fan XY, Hu Z. Natural products in anti-tuberculosis host-directed therapy. Biomed Pharmacother 2024; 171:116087. [PMID: 38171242 DOI: 10.1016/j.biopha.2023.116087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/17/2023] [Accepted: 12/26/2023] [Indexed: 01/05/2024] Open
Abstract
Given that the disease progression of tuberculosis (TB) is primarily related to the host's immune status, it has been gradually realized that chemotherapy that targets the bacteria may never, on its own, wholly eradicate Mycobacterium tuberculosis, the causative agent of TB. The concept of host-directed therapy (HDT) with immune adjuvants has emerged. HDT could potentially interfere with infection and colonization by the pathogens, enhance the protective immune responses of hosts, suppress the overwhelming inflammatory responses, and help to attain a state of homeostasis that favors treatment efficacy. However, the HDT drugs currently being assessed in combination with anti-TB chemotherapy still face the dilemmas arising from side effects and high costs. Natural products are well suited to compensate for these shortcomings by having gentle modulatory effects on the host immune responses with less immunopathological damage at a lower cost. In this review, we first summarize the profiles of anti-TB immunology and the characteristics of HDT. Then, we focus on the rationale and challenges of developing and implementing natural products-based HDT. A succinct report of the medications currently being evaluated in clinical trials and preclinical studies is provided. This review aims to promote target-based screening and accelerate novel TB drug discovery.
Collapse
Affiliation(s)
- Xuejiao Huang
- Shanghai Public Health Clinical Center & Shanghai Institute of Infectious Diseases and Biosecurity, Fudan University, Shanghai 201508, China
| | - Douglas B Lowrie
- Shanghai Public Health Clinical Center & Shanghai Institute of Infectious Diseases and Biosecurity, Fudan University, Shanghai 201508, China
| | - Xiao-Yong Fan
- Shanghai Public Health Clinical Center & Shanghai Institute of Infectious Diseases and Biosecurity, Fudan University, Shanghai 201508, China.
| | - Zhidong Hu
- Shanghai Public Health Clinical Center & Shanghai Institute of Infectious Diseases and Biosecurity, Fudan University, Shanghai 201508, China.
| |
Collapse
|
5
|
Chen X, Feng Y, Quinn RJ, Pountney DL, Richardson DR, Mellick GD, Ma L. Potassium Channels in Parkinson's Disease: Potential Roles in Its Pathogenesis and Innovative Molecular Targets for Treatment. Pharmacol Rev 2023; 75:758-788. [PMID: 36918260 DOI: 10.1124/pharmrev.122.000743] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 01/05/2023] [Accepted: 03/07/2023] [Indexed: 03/16/2023] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder characterized by selective loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) region of the midbrain. The loss of neurons results in a subsequent reduction of dopamine in the striatum, which underlies the core motor symptoms of PD. To date, there are no effective treatments to stop, slow, or reverse the pathologic progression of dopaminergic neurodegeneration. This unfortunate predicament is because of the current early stages in understanding the biologic targets and pathways involved in PD pathogenesis. Ion channels have become emerging targets for new therapeutic development for PD due to their essential roles in neuronal function and neuroinflammation. Potassium channels are the most prominent ion channel family and have been shown to be critically important in PD pathology because of their roles in modulating neuronal excitability, neurotransmitter release, synaptic transmission, and neuroinflammation. In this review, members of the subfamilies of voltage-gated K+ channels, inward rectifying K+ channels, and Ca2+-activated K+ channels are described. Evidence of the role of these channels in PD etiology is discussed together with the latest views on related pathologic mechanisms and their potential as biologic targets for developing neuroprotective drugs for PD. SIGNIFICANCE STATEMENT: Parkinson's disease (PD) is the second most common neurodegenerative disorder, featuring progressive degeneration of dopaminergic neurons in the midbrain. It is a multifactorial disease involving multiple risk factors and complex pathobiological mechanisms. Mounting evidence suggests that ion channels play vital roles in the pathogenesis and progression of PD by regulating neuronal excitability and immune cell function. Therefore, they have become "hot" biological targets for PD, as demonstrated by multiple clinical trials of drug candidates targeting ion channels for PD therapy.
Collapse
Affiliation(s)
- Xiaoyi Chen
- School of Environment and Science (Y.F., D.R.R., G.D.M., L.M.) and Centre for Cancer Cell Biology and Drug Discovery (D.R.R.), Griffith Institute for Drug Discovery (X.C., Y.F., R.J.Q., D.R.R., G.D.M., L.M.), Griffith University, Nathan, Brisbane, Queensland, Australia; and School of Pharmacy and Medical Science, Griffith University, Gold Coast, Queenslandstate, Australia (D.L.P.)
| | - Yunjiang Feng
- School of Environment and Science (Y.F., D.R.R., G.D.M., L.M.) and Centre for Cancer Cell Biology and Drug Discovery (D.R.R.), Griffith Institute for Drug Discovery (X.C., Y.F., R.J.Q., D.R.R., G.D.M., L.M.), Griffith University, Nathan, Brisbane, Queensland, Australia; and School of Pharmacy and Medical Science, Griffith University, Gold Coast, Queenslandstate, Australia (D.L.P.)
| | - Ronald J Quinn
- School of Environment and Science (Y.F., D.R.R., G.D.M., L.M.) and Centre for Cancer Cell Biology and Drug Discovery (D.R.R.), Griffith Institute for Drug Discovery (X.C., Y.F., R.J.Q., D.R.R., G.D.M., L.M.), Griffith University, Nathan, Brisbane, Queensland, Australia; and School of Pharmacy and Medical Science, Griffith University, Gold Coast, Queenslandstate, Australia (D.L.P.)
| | - Dean L Pountney
- School of Environment and Science (Y.F., D.R.R., G.D.M., L.M.) and Centre for Cancer Cell Biology and Drug Discovery (D.R.R.), Griffith Institute for Drug Discovery (X.C., Y.F., R.J.Q., D.R.R., G.D.M., L.M.), Griffith University, Nathan, Brisbane, Queensland, Australia; and School of Pharmacy and Medical Science, Griffith University, Gold Coast, Queenslandstate, Australia (D.L.P.)
| | - Des R Richardson
- School of Environment and Science (Y.F., D.R.R., G.D.M., L.M.) and Centre for Cancer Cell Biology and Drug Discovery (D.R.R.), Griffith Institute for Drug Discovery (X.C., Y.F., R.J.Q., D.R.R., G.D.M., L.M.), Griffith University, Nathan, Brisbane, Queensland, Australia; and School of Pharmacy and Medical Science, Griffith University, Gold Coast, Queenslandstate, Australia (D.L.P.)
| | - George D Mellick
- School of Environment and Science (Y.F., D.R.R., G.D.M., L.M.) and Centre for Cancer Cell Biology and Drug Discovery (D.R.R.), Griffith Institute for Drug Discovery (X.C., Y.F., R.J.Q., D.R.R., G.D.M., L.M.), Griffith University, Nathan, Brisbane, Queensland, Australia; and School of Pharmacy and Medical Science, Griffith University, Gold Coast, Queenslandstate, Australia (D.L.P.)
| | - Linlin Ma
- School of Environment and Science (Y.F., D.R.R., G.D.M., L.M.) and Centre for Cancer Cell Biology and Drug Discovery (D.R.R.), Griffith Institute for Drug Discovery (X.C., Y.F., R.J.Q., D.R.R., G.D.M., L.M.), Griffith University, Nathan, Brisbane, Queensland, Australia; and School of Pharmacy and Medical Science, Griffith University, Gold Coast, Queenslandstate, Australia (D.L.P.)
| |
Collapse
|
6
|
Ong ST, Tyagi A, Chandy KG, Bhushan S. Mechanisms Underlying C-type Inactivation in Kv Channels: Lessons From Structures of Human Kv1.3 and Fly Shaker-IR Channels. Front Pharmacol 2022; 13:924289. [PMID: 35833027 PMCID: PMC9271579 DOI: 10.3389/fphar.2022.924289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 06/06/2022] [Indexed: 11/13/2022] Open
Abstract
Voltage-gated potassium (Kv) channels modulate the function of electrically-excitable and non-excitable cells by using several types of “gates” to regulate ion flow through the channels. An important gating mechanism, C-type inactivation, limits ion flow by transitioning Kv channels into a non-conducting inactivated state. Here, we highlight two recent papers, one on the human Kv1.3 channel and the second on the Drosophila Shaker Kv channel, that combined cryogenic electron microscopy and molecular dynamics simulation to define mechanisms underlying C-type inactivation. In both channels, the transition to the non-conducting inactivated conformation begins with the rupture of an intra-subunit hydrogen bond that fastens the selectivity filter to the pore helix. The freed filter swings outwards and gets tethered to an external residue. As a result, the extracellular end of the selectivity filter dilates and K+ permeation through the pore is impaired. Recovery from inactivation may entail a reversal of this process. Such a reversal, at least partially, is induced by the peptide dalazatide. Binding of dalazatide to external residues in Kv1.3 frees the filter to swing inwards. The extracellular end of the selectivity filter narrows allowing K+ to move in single file through the pore typical of conventional knock-on conduction. Inter-subunit hydrogen bonds that stabilize the outer pore in the dalazatide-bound structure are equivalent to those in open-conducting conformations of Kv channels. However, the intra-subunit bond that fastens the filter to the pore-helix is absent, suggesting an incomplete reversal of the process. These mechanisms define how Kv channels self-regulate the flow of K+ by changing the conformation of the selectivity filter.
Collapse
Affiliation(s)
- Seow Theng Ong
- LKCMedicine-ICESing Ion Channel Platform, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Anu Tyagi
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- Singapore and Nanyang Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore
| | - K. George Chandy
- LKCMedicine-ICESing Ion Channel Platform, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- *Correspondence: K. George Chandy, ; Shashi Bhushan,
| | - Shashi Bhushan
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- Singapore and Nanyang Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore
- *Correspondence: K. George Chandy, ; Shashi Bhushan,
| |
Collapse
|
7
|
Wrzosek A, Gałecka S, Żochowska M, Olszewska A, Kulawiak B. Alternative Targets for Modulators of Mitochondrial Potassium Channels. Molecules 2022; 27:299. [PMID: 35011530 PMCID: PMC8746388 DOI: 10.3390/molecules27010299] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial potassium channels control potassium influx into the mitochondrial matrix and thus regulate mitochondrial membrane potential, volume, respiration, and synthesis of reactive oxygen species (ROS). It has been found that pharmacological activation of mitochondrial potassium channels during ischemia/reperfusion (I/R) injury activates cytoprotective mechanisms resulting in increased cell survival. In cancer cells, the inhibition of these channels leads to increased cell death. Therefore, mitochondrial potassium channels are intriguing targets for the development of new pharmacological strategies. In most cases, however, the substances that modulate the mitochondrial potassium channels have a few alternative targets in the cell. This may result in unexpected or unwanted effects induced by these compounds. In our review, we briefly present the various classes of mitochondrial potassium (mitoK) channels and describe the chemical compounds that modulate their activity. We also describe examples of the multidirectional activity of the activators and inhibitors of mitochondrial potassium channels.
Collapse
Affiliation(s)
- Antoni Wrzosek
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Shur Gałecka
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Monika Żochowska
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Anna Olszewska
- Department of Histology, Medical University of Gdansk, 1a Debinki, 80-211 Gdansk, Poland;
| | - Bogusz Kulawiak
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| |
Collapse
|
8
|
Hwang S, Kim JH, Jo SH. Inhibitory effect of the selective serotonin reuptake inhibitor paroxetine on human Kv1.3 channels. Eur J Pharmacol 2021; 912:174567. [PMID: 34662565 DOI: 10.1016/j.ejphar.2021.174567] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 09/30/2021] [Accepted: 10/11/2021] [Indexed: 01/12/2023]
Abstract
Paroxetine is one of the most effective selective serotonin reuptake inhibitors used to treat depressive and panic disorders that reduce the viability of human T lymphocytes, in which Kv1.3 channels are highly expressed. We examined whether paroxetine could modulate human Kv1.3 channels acutely and directly with the aim of understanding the biophysical effects and the underlying mechanisms of the drug. Kv1.3 channel proteins were expressed in Xenopus oocytes. Paroxetine rapidly inhibited the steady-state current and peak current of these channels within 6 min in a concentration-dependent manner; IC50s were 26.3 μM and 53.9 μM, respectively, and these effects were partially reversed by washout, which excluded the possibility of genomic regulation. At the same test voltage, paroxetine blockade of the steady-state currents was higher than that of the peak currents, and the inhibition of the steady-state current increased relative to the degree of depolarization. Paroxetine decreased the inactivation time constant in a concentration-dependent manner, but it did not affect the activation time constant, which resulted in the acceleration of intrinsic inactivation without changing ultrarapid activation. Blockade of Kv1.3 channels by paroxetine exhibited more rapid inhibition at higher activation frequencies showing the use-dependency of the blockade. Overall, these results show that paroxetine directly suppresses human Kv1.3 channels in an open state and accelerates the process of steady-state inactivation; thus, we have revealed a biophysical mechanism for possible acute immunosuppressive effects of paroxetine.
Collapse
Affiliation(s)
- Soobeen Hwang
- Department of Physiology, Institute of Bioscience and Biotechnology, Interdisciplinary Graduate Program in BIT Medical Convergence, Kangwon National University School of Medicine, Chuncheon, 24341, South Korea
| | - Jong-Hui Kim
- Department of Physiology, Institute of Bioscience and Biotechnology, Interdisciplinary Graduate Program in BIT Medical Convergence, Kangwon National University School of Medicine, Chuncheon, 24341, South Korea
| | - Su-Hyun Jo
- Department of Physiology, Institute of Bioscience and Biotechnology, Interdisciplinary Graduate Program in BIT Medical Convergence, Kangwon National University School of Medicine, Chuncheon, 24341, South Korea.
| |
Collapse
|
9
|
Gubič Š, Hendrickx LA, Toplak Ž, Sterle M, Peigneur S, Tomašič T, Pardo LA, Tytgat J, Zega A, Mašič LP. Discovery of K V 1.3 ion channel inhibitors: Medicinal chemistry approaches and challenges. Med Res Rev 2021; 41:2423-2473. [PMID: 33932253 PMCID: PMC8252768 DOI: 10.1002/med.21800] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 03/03/2021] [Accepted: 03/19/2021] [Indexed: 12/12/2022]
Abstract
The KV 1.3 voltage-gated potassium ion channel is involved in many physiological processes both at the plasma membrane and in the mitochondria, chiefly in the immune and nervous systems. Therapeutic targeting KV 1.3 with specific peptides and small molecule inhibitors shows great potential for treating cancers and autoimmune diseases, such as multiple sclerosis, type I diabetes mellitus, psoriasis, contact dermatitis, rheumatoid arthritis, and myasthenia gravis. However, no KV 1.3-targeted compounds have been approved for therapeutic use to date. This review focuses on the presentation of approaches for discovering new KV 1.3 peptide and small-molecule inhibitors, and strategies to improve the selectivity of active compounds toward KV 1.3. Selectivity of dalatazide (ShK-186), a synthetic derivate of the sea anemone toxin ShK, was achieved by chemical modification and has successfully reached clinical trials as a potential therapeutic for treating autoimmune diseases. Other peptides and small-molecule inhibitors are critically evaluated for their lead-like characteristics and potential for progression into clinical development. Some small-molecule inhibitors with well-defined structure-activity relationships have been optimized for selective delivery to mitochondria, and these offer therapeutic potential for the treatment of cancers. This overview of KV 1.3 inhibitors and methodologies is designed to provide a good starting point for drug discovery to identify novel effective KV 1.3 modulators against this target in the future.
Collapse
Affiliation(s)
- Špela Gubič
- Faculty of PharmacyUniversity of LjubljanaLjubljanaSlovenia
| | - Louise A. Hendrickx
- Toxicology and PharmacologyUniversity of Leuven, Campus GasthuisbergLeuvenBelgium
| | - Žan Toplak
- Faculty of PharmacyUniversity of LjubljanaLjubljanaSlovenia
| | - Maša Sterle
- Faculty of PharmacyUniversity of LjubljanaLjubljanaSlovenia
| | - Steve Peigneur
- Faculty of PharmacyUniversity of LjubljanaLjubljanaSlovenia
| | | | - Luis A. Pardo
- AG OncophysiologyMax‐Planck Institute for Experimental MedicineGöttingenGermany
| | - Jan Tytgat
- Toxicology and PharmacologyUniversity of Leuven, Campus GasthuisbergLeuvenBelgium
| | - Anamarija Zega
- Faculty of PharmacyUniversity of LjubljanaLjubljanaSlovenia
| | | |
Collapse
|
10
|
Li M, Yu H. Identification of WP1066, an inhibitor of JAK2 and STAT3, as a K V 1.3 potassium channel blocker. Br J Pharmacol 2021; 178:2617-2631. [PMID: 33689167 DOI: 10.1111/bph.15441] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 01/15/2021] [Accepted: 02/09/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND AND PURPOSE KV 1.3 potassium channels play a predominant role in regulating calcium signalling that is essential for the activation and proliferation of effector memory T (TEM ) cells. This ion channel has been recognized as a promising therapeutic target against various autoimmune diseases. EXPERIMENTAL APPROACH In a high-throughput screening programme, WP1066 was identified as a KV 1.3 channel inhibitor. Using molecular biology and electrophysiological methods, the mechanism(s) underlying WP1066 blockade of Kv1.3 channels was investigated. Using TEM cell proliferation assay and mouse delayed-type hypersensitivity (DTH) model, the effects of WP1066 were examined. KEY RESULTS WP1066 blocked KV 1.3 channels in a dose-dependent manner with an IC50 of 3.2 μM and induced a hyperpolarizing shift of the steady-state inactivation curve. This blockade was use-dependent, as WP1066 interacted preferentially with channels in their open state, rather than the closed state or inactivated state. When the residues located in the S6 domain scaffolding the inner vestibule, were sequentially mutated, the potency of WP1066 was significantly impaired, especially by mutations A413C and I420C, indicating a higher affinity of interacting sites for WP1066. Moreover, WP1066 effectively suppressed mouse TEM cell proliferation in vitro and mouse DTH reaction in vivo. CONCLUSIONS AND IMPLICATIONS The results presented here have identified WP1066 as a KV 1.3 channel blocker with an open-state-dependent property, providing fundamental evidence for the application of WP1066 in further immunomodulatory studies targeting KV 1.3 channels.
Collapse
Affiliation(s)
- Min Li
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Haibo Yu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| |
Collapse
|
11
|
Wu J, Cao S, Lei S, Liu Q, Li Y, Yu Y, Xie H, Li Q, Zhao X, Chen R, Huang W, Xiao X, Yu Y, Song D, Li Y, Wang Y. Clofazimine: A Promising Inhibitor of Rabies Virus. Front Pharmacol 2021; 12:598241. [PMID: 33815101 PMCID: PMC8012719 DOI: 10.3389/fphar.2021.598241] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 02/09/2021] [Indexed: 12/25/2022] Open
Abstract
With an almost 100% mortality rate, rabies virus (RABV) infection is a global concern. Limited post-exposure prophylaxis and lack of an effective treatment necessitate novel antiviral therapies against RABV. Here, using a high-throughput screening (HTS) method developed in our lab, 11 candidates with anti-RABV activity were identified from a library of 767 clinical drugs. Clofazimine (CFZ), an anti-leprosy drug, displayed an EC50 of 2.28 μM, and SI over 967 against RABV. Investigations into the underlying mechanisms revealed that CFZ targeted viral membrane fusion at the early stages of virus replication. Moreover, CFZ and Clofazimine salicylates (CFZS) exhibited elevated survival rates in vivo, compared with the positive control T-705. Thus, this study revealed CFZ as a promising drug against RABV infection.
Collapse
Affiliation(s)
- Jiajing Wu
- Department of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China
- Wuhan Institute of Biological Products, Hubei, China
| | - Shouchun Cao
- Department of Arboviral Vaccine, National Institutes for Food and Drug Control, Beijing, China
| | - Shan Lei
- Department of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China
| | - Qiang Liu
- Department of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China
| | - Yinghong Li
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Yueyang Yu
- Department of Arboviral Vaccine, National Institutes for Food and Drug Control, Beijing, China
| | - Hui Xie
- Department of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China
| | - Qianqian Li
- Department of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China
| | - Xiaoqiang Zhao
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Ruifeng Chen
- Department of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China
| | - Weijin Huang
- Department of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China
| | - Xinyue Xiao
- Institute for Reference Standards and Standardization, National Institutes for Food and Drug Control, Beijing, China
| | - Yongxin Yu
- Department of Arboviral Vaccine, National Institutes for Food and Drug Control, Beijing, China
| | - Danqing Song
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Yuhua Li
- Department of Arboviral Vaccine, National Institutes for Food and Drug Control, Beijing, China
| | - Youchun Wang
- Department of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China
| |
Collapse
|
12
|
Cidad P, Alonso E, Arévalo-Martínez M, Calvo E, de la Fuente MA, Pérez-García MT, López-López JR. Voltage-dependent conformational changes of Kv1.3 channels activate cell proliferation. J Cell Physiol 2020; 236:4330-4347. [PMID: 33230847 DOI: 10.1002/jcp.30170] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 09/30/2020] [Accepted: 10/15/2020] [Indexed: 01/09/2023]
Abstract
The voltage-dependent potassium channel Kv1.3 has been implicated in proliferation in many cell types, based on the observation that Kv1.3 blockers inhibited proliferation. By modulating membrane potential, cell volume, and/or Ca2+ influx, K+ channels can influence cell cycle progression. Also, noncanonical channel functions could contribute to modulate cell proliferation independent of K+ efflux. The specificity of the requirement of Kv1.3 channels for proliferation suggests the involvement of molecule-specific interactions, but the underlying mechanisms are poorly identified. Heterologous expression of Kv1.3 channels in HEK cells has been shown to increase proliferation independently of K+ fluxes. Likewise, some of the molecular determinants of Kv1.3-induced proliferation have been located in the C-terminus region, where individual point mutations of putative phosphorylation sites (Y447A and S459A) abolished Kv1.3-induced proliferation. Here, we investigated the mechanisms linking Kv1.3 channels to proliferation exploring the correlation between Kv1.3 voltage-dependent molecular dynamics and cell cycle progression. Using transfected HEK cells, we analyzed both the effect of changes in resting membrane potential on Kv1.3-induced proliferation and the effect of mutated Kv1.3 channels with altered voltage dependence of gating. We conclude that voltage-dependent transitions of Kv1.3 channels enable the activation of proliferative pathways. We also found that Kv1.3 associated with IQGAP3, a scaffold protein involved in proliferation, and that membrane depolarization facilitates their interaction. The functional contribution of Kv1.3-IQGAP3 interplay to cell proliferation was demonstrated both in HEK cells and in vascular smooth muscle cells. Our data indicate that voltage-dependent conformational changes of Kv1.3 are an essential element in Kv1.3-induced proliferation.
Collapse
Affiliation(s)
- Pilar Cidad
- Departamento de Bioquímica y Biología Molecular y Fisiología, Universidad de Valladolid, Valladolid, Spain.,Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y CSIC, Valladolid, Spain
| | - Esperanza Alonso
- Departamento de Bioquímica y Biología Molecular y Fisiología, Universidad de Valladolid, Valladolid, Spain.,Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y CSIC, Valladolid, Spain
| | - Marycarmen Arévalo-Martínez
- Departamento de Bioquímica y Biología Molecular y Fisiología, Universidad de Valladolid, Valladolid, Spain.,Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y CSIC, Valladolid, Spain
| | - Enrique Calvo
- Centro Nacional de Investigaciones Cardiovasculares, Unidad de Proteómica, CNIC, Madrid, Spain
| | - Miguel A de la Fuente
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y CSIC, Valladolid, Spain.,Departamento de Biología Celular, Universidad de Valladolid, Valladolid, Spain
| | - M Teresa Pérez-García
- Departamento de Bioquímica y Biología Molecular y Fisiología, Universidad de Valladolid, Valladolid, Spain.,Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y CSIC, Valladolid, Spain
| | - José R López-López
- Departamento de Bioquímica y Biología Molecular y Fisiología, Universidad de Valladolid, Valladolid, Spain.,Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y CSIC, Valladolid, Spain
| |
Collapse
|
13
|
Griffin M, Khan R, Basu S, Smith S. Ion Channels as Therapeutic Targets in High Grade Gliomas. Cancers (Basel) 2020; 12:cancers12103068. [PMID: 33096667 PMCID: PMC7589494 DOI: 10.3390/cancers12103068] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/16/2020] [Accepted: 10/19/2020] [Indexed: 12/12/2022] Open
Abstract
Simple Summary Glioblastoma multiforme is an aggressive grade IV lethal brain tumour with a median survival of 14 months. Despite surgery to remove the tumour, and subsequent concurrent chemotherapy and radiotherapy, there is little in terms of effective treatment options. Because of this, exploring new treatment avenues is vital. Brain tumours are intrinsically electrically active; expressing unique patterns of ion channels, and this is a characteristic we can exploit. Ion channels are specialised proteins in the cell’s membrane that allow for the passage of positive and negatively charged ions in and out of the cell, controlling membrane potential. Membrane potential is a crucial biophysical signal in normal and cancerous cells. Research has identified that specific classes of ion channels not only move the cell through its cell cycle, thus encouraging growth and proliferation, but may also be essential in the development of brain tumours. Inhibition of sodium, potassium, calcium, and chloride channels has been shown to reduce the capacity of glioblastoma cells to grow and invade. Therefore, we propose that targeting ion channels and repurposing commercially available ion channel inhibitors may hold the key to new therapeutic avenues in high grade gliomas. Abstract Glioblastoma multiforme (GBM) is a lethal brain cancer with an average survival of 14–15 months even with exhaustive treatment. High grade gliomas (HGG) represent the leading cause of CNS cancer-related death in children and adults due to the aggressive nature of the tumour and limited treatment options. The scarcity of treatment available for GBM has opened the field to new modalities such as electrotherapy. Previous studies have identified the clinical benefit of electrotherapy in combination with chemotherapeutics, however the mechanistic action is unclear. Increasing evidence indicates that not only are ion channels key in regulating electrical signaling and membrane potential of excitable cells, they perform a crucial role in the development and neoplastic progression of brain tumours. Unlike other tissue types, neural tissue is intrinsically electrically active and reliant on ion channels and their function. Ion channels are essential in cell cycle control, invasion and migration of cancer cells and therefore present as valuable therapeutic targets. This review aims to discuss the role that ion channels hold in gliomagenesis and whether we can target and exploit these channels to provide new therapeutic targets and whether ion channels hold the mechanistic key to the newfound success of electrotherapies.
Collapse
Affiliation(s)
- Michaela Griffin
- Children’s Brain Tumour Research Centre, Biodiscovery Institute, University of Nottingham, Nottingham NG7 2RD, UK;
| | - Raheela Khan
- Division of Medical Sciences and Graduate Entry Medicine, Royal Derby Hospital, University of Nottingham, Nottingham NG7 2RD, UK;
| | - Surajit Basu
- Department of Neurosurgery, Queen’s Medical Centre, Nottingham University Hospitals, Nottingham NG7 2RD, UK;
| | - Stuart Smith
- Children’s Brain Tumour Research Centre, Biodiscovery Institute, University of Nottingham, Nottingham NG7 2RD, UK;
- Correspondence:
| |
Collapse
|
14
|
George J. Metabolism and interactions of antileprosy drugs. Biochem Pharmacol 2020; 177:113993. [PMID: 32339493 DOI: 10.1016/j.bcp.2020.113993] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 04/21/2020] [Indexed: 01/29/2023]
Abstract
Leprosy is a chronic infectious disease caused my Mycobacterium leprae that primarily affects peripheral nervous system and extremities and is prevalent in tropical countries. Treatment for leprosy with multidrug regimens is very effective compared to monotherapy especially in multibacillary cases. The three major antileprosy drugs currently in use are 4, 4'-diaminodiphenyl sulfone (DDS, dapsone), rifampicin, and clofazimine. During multidrug therapy, the potent antibiotic rifampicin induces the metabolism of dapsone, which results in decreased plasma half-life of dapsone and its metabolites. Furthermore, rifampicin induces its own metabolism and decreases its half-life during monotherapy. Rifampicin upregulates several hepatic microsomal drug-metabolizing enzymes, especially cytochrome P450 (CYP) family that in turn induce the metabolism of dapsone. Clofazimine lacks significant induction of any drug-metabolizing enzyme including CYP family and does not interact with dapsone metabolism. Rifampicin does not induce clofazimine metabolism during combination treatment. Administration of dapsone in the acetylated form (acedapsone) can release the drug slowly into circulation up to 75 days and could be useful for the effective treatment of paucibacillary cases along with rifampicin. This review summarizes the major aspects of antileprosy drug metabolism and drug interactions and the role of cytochrome P450 family of drug metabolizing enzymes, especially CYP3A4 during multidrug regimens for the treatment of leprosy.
Collapse
Affiliation(s)
- Joseph George
- Department of Biochemistry, Central Leprosy Teaching and Research Institute, Chengalpattu 603001, Tamil Nadu, India.
| |
Collapse
|
15
|
Prosdocimi E, Checchetto V, Leanza L. Targeting the Mitochondrial Potassium Channel Kv1.3 to Kill Cancer Cells: Drugs, Strategies, and New Perspectives. SLAS DISCOVERY 2019; 24:882-892. [PMID: 31373829 DOI: 10.1177/2472555219864894] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cancer is the consequence of aberrations in cell growth or cell death. In this scenario, mitochondria and ion channels play a critical role in regard to cell proliferation, malignant angiogenesis, migration, and metastasis. In this review, we focus on Kv1.3 and specifically on mitoKv1.3, which showed an aberrant expression in cancer cells compared with healthy tissues and which is involved in the apoptotic pathway. In recent years, mitoKv1.3 has become an oncological target since its pharmacological modulation has been demonstrated to reduce tumor growth and progression both in vitro and in vivo using preclinical mouse models of different types of tumors.
Collapse
Affiliation(s)
| | | | - Luigi Leanza
- Department of Biology, University of Padova, Padova, Italy
| |
Collapse
|
16
|
Yang JF, Cheng N, Ren S, Liu XM, Li XT. Characterization and molecular basis for the block of Kv1.3 channels induced by carvedilol in HEK293 cells. Eur J Pharmacol 2018; 834:206-212. [PMID: 30016664 DOI: 10.1016/j.ejphar.2018.07.025] [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: 05/25/2018] [Revised: 07/04/2018] [Accepted: 07/13/2018] [Indexed: 10/28/2022]
Abstract
Carvedilol is a non-selective β-adrenoreceptor antagonist and exhibits a wide range of biological activities. The voltage-gated K+ (Kv) channel is one of the target ion channels of this compound. The rapidly activating Kv1.3 channel is expressed in several different tissues and plays an important role in the regulation of physiological functions, including cell proliferation and apoptosis. However, little is known about the possible action of carvedilol on Kv1.3 currents. Using the whole-cell configuration of the patch-clamp technique, we have revealed that exposure to carvedilol produced a concentration-dependent blocking of Kv1.3 channels heterologously expressed in HEK293 cells, with an IC50 value of 9.7 μM. This chemical decelerated the deactivation tail current of Kv1.3 currents, resulting in a tail crossover phenomenon. In addition, carvedilol generated a markedly hyperpolarizing shift (20 mV) of the inactivation curve, but failed to affect the activation curve. Mutagenesis experiments of Kv1.3 channels identified G427 and H451, two related sites of TEA block, as important residues for carvedilol-mediated blocking. The present results suggest that carvedilol acts directly on Kv1.3 currents by inducing closed- and open-channel block and helps to elucidate the mechanisms of action of this compound on Kv channels.
Collapse
Affiliation(s)
- Jin-Feng Yang
- College of Life Science, South-Central University for Nationalities, Wuhan 430074, China
| | - Neng Cheng
- College of Life Science, South-Central University for Nationalities, Wuhan 430074, China
| | - Sheng Ren
- College of Life Science, South-Central University for Nationalities, Wuhan 430074, China
| | - Xiang-Ming Liu
- GongQing Institute of Science and Technology, Gongqing City 332020, China
| | - Xian-Tao Li
- College of Life Science, South-Central University for Nationalities, Wuhan 430074, China.
| |
Collapse
|
17
|
Love MS, Beasley FC, Jumani RS, Wright TM, Chatterjee AK, Huston CD, Schultz PG, McNamara CW. A high-throughput phenotypic screen identifies clofazimine as a potential treatment for cryptosporidiosis. PLoS Negl Trop Dis 2017; 11:e0005373. [PMID: 28158186 PMCID: PMC5310922 DOI: 10.1371/journal.pntd.0005373] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 02/15/2017] [Accepted: 01/30/2017] [Indexed: 11/19/2022] Open
Abstract
Cryptosporidiosis has emerged as a leading cause of non-viral diarrhea in children under five years of age in the developing world, yet the current standard of care to treat Cryptosporidium infections, nitazoxanide, demonstrates limited and immune-dependent efficacy. Given the lack of treatments with universal efficacy, drug discovery efforts against cryptosporidiosis are necessary to find therapeutics more efficacious than the standard of care. To date, cryptosporidiosis drug discovery efforts have been limited to a few targeted mechanisms in the parasite and whole cell phenotypic screens against small, focused collections of compounds. Using a previous screen as a basis, we initiated the largest known drug discovery effort to identify novel anticryptosporidial agents. A high-content imaging assay for inhibitors of Cryptosporidium parvum proliferation within a human intestinal epithelial cell line was miniaturized and automated to enable high-throughput phenotypic screening against a large, diverse library of small molecules. A screen of 78,942 compounds identified 12 anticryptosporidial hits with sub-micromolar activity, including clofazimine, an FDA-approved drug for the treatment of leprosy, which demonstrated potent and selective in vitro activity (EC50 = 15 nM) against C. parvum. Clofazimine also displayed activity against C. hominis-the other most clinically-relevant species of Cryptosporidium. Importantly, clofazimine is known to accumulate within epithelial cells of the small intestine, the primary site of Cryptosporidium infection. In a mouse model of acute cryptosporidiosis, a once daily dosage regimen for three consecutive days or a single high dose resulted in reduction of oocyst shedding below the limit detectable by flow cytometry. Recently, a target product profile (TPP) for an anticryptosporidial compound was proposed by Huston et al. and highlights the need for a short dosing regimen (< 7 days) and formulations for children < 2 years. Clofazimine has a long history of use and has demonstrated a good safety profile for a disease that requires chronic dosing for a period of time ranging 3-36 months. These results, taken with clofazimine's status as an FDA-approved drug with over four decades of use for the treatment of leprosy, support the continued investigation of clofazimine both as a new chemical tool for understanding cryptosporidium biology and a potential new treatment of cryptosporidiosis.
Collapse
Affiliation(s)
- Melissa S. Love
- California Institute for Biomedical Research, La Jolla, California, United States of America
| | - Federico C. Beasley
- California Institute for Biomedical Research, La Jolla, California, United States of America
| | - Rajiv S. Jumani
- Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont, United States of America
| | - Timothy M. Wright
- California Institute for Biomedical Research, La Jolla, California, United States of America
| | - Arnab K. Chatterjee
- California Institute for Biomedical Research, La Jolla, California, United States of America
| | - Christopher D. Huston
- Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont, United States of America
| | - Peter G. Schultz
- California Institute for Biomedical Research, La Jolla, California, United States of America
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Case W. McNamara
- California Institute for Biomedical Research, La Jolla, California, United States of America
- * E-mail:
| |
Collapse
|
18
|
Cholo MC, Mothiba MT, Fourie B, Anderson R. Mechanisms of action and therapeutic efficacies of the lipophilic antimycobacterial agents clofazimine and bedaquiline. J Antimicrob Chemother 2016; 72:338-353. [PMID: 27798208 DOI: 10.1093/jac/dkw426] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Drug-resistant (DR)-TB is the major challenge confronting the global TB control programme, necessitating treatment with second-line anti-TB drugs, often with limited therapeutic efficacy. This scenario has resulted in the inclusion of Group 5 antibiotics in various therapeutic regimens, two of which promise to impact significantly on the outcome of the therapy of DR-TB. These are the 're-purposed' riminophenazine, clofazimine, and the recently approved diarylquinoline, bedaquiline. Although they differ structurally, both of these lipophilic agents possess cationic amphiphilic properties that enable them to target and inactivate essential ion transporters in the outer membrane of Mycobacterium tuberculosis. In the case of bedaquiline, the primary target is the key respiratory chain enzyme F1/F0-ATPase, whereas clofazimine is less selective, apparently inhibiting several targets, which may underpin the extremely low level of resistance to this agent. This review is focused on similarities and differences between clofazimine and bedaquiline, specifically in respect of molecular mechanisms of antimycobacterial action, targeting of quiescent and metabolically active organisms, therapeutic efficacy in the clinical setting of DR-TB, resistance mechanisms, pharmacodynamics, pharmacokinetics and adverse events.
Collapse
Affiliation(s)
- Moloko C Cholo
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa
| | - Maborwa T Mothiba
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa
| | - Bernard Fourie
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa
| | - Ronald Anderson
- Institute for Cellular and Molecular Medicine, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa
| |
Collapse
|
19
|
Faouzi M, Starkus J, Penner R. State-dependent blocking mechanism of Kv 1.3 channels by the antimycobacterial drug clofazimine. Br J Pharmacol 2015; 172:5161-73. [PMID: 26276903 DOI: 10.1111/bph.13283] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 07/15/2015] [Accepted: 08/10/2015] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND AND PURPOSE Kv 1.3 potassium channels are promising pharmaceutical targets for treating immune diseases as they modulate Ca(2+) signalling in T cells by regulating the membrane potential and with it the driving force for Ca(2+) influx. The antimycobacterial drug clofazimine has been demonstrated to attenuate antigen-induced Ca(2+) oscillations, suppress cytokine release and prevent skin graft rejection by inhibiting Kv 1.3 channels with high potency and selectivity. EXPERIMENTAL APPROACH We used patch-clamp methodology to investigate clofazimine's mechanism of action in Kv 1.3 channels expressed in HEK293 cells. KEY RESULTS Clofazimine blocked Kv 1.3 channels by involving two discrete mechanisms, both of which contribute to effective suppression of channels: (i) a use-dependent open-channel block during long depolarizations, resulting in accelerated K(+) current inactivation and (ii) a block of closed deactivated channels after channels were opened by brief depolarizations. Both modes of block were use-dependent and state-dependent in that they clearly required prior channel opening. The clofazimine-sensitive closed-deactivated state of the channel was distinct from the resting closed state because channels at hyperpolarized voltages were not inhibited by clofazimine. Neither were channels in the C-type inactivated state significantly affected. Kv 1.3 channels carrying the H399T mutation and lacking C-type inactivation were insensitive to clofazimine block of the closed-deactivated state, but retained their susceptibility to open-channel block. CONCLUSIONS AND IMPLICATIONS Given the prominent role of Kv 1.3 in shaping Ca(2+) oscillations, the use-dependent and state-dependent block of Kv 1.3 channels by clofazimine offers therapeutic potential for selective immunosuppression in the context of autoimmune diseases in which Kv 1.3-expressing T cells play a significant role.
Collapse
Affiliation(s)
- Malika Faouzi
- Laboratory of Cell and Molecular Signaling, Center for Biomedical Research, The Queen's Medical Center, Honolulu, HI, 96813, USA.,John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, 96813, USA
| | - John Starkus
- Laboratory of Cell and Molecular Signaling, Center for Biomedical Research, The Queen's Medical Center, Honolulu, HI, 96813, USA.,John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, 96813, USA
| | - Reinhold Penner
- Laboratory of Cell and Molecular Signaling, Center for Biomedical Research, The Queen's Medical Center, Honolulu, HI, 96813, USA.,John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, 96813, USA
| |
Collapse
|