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Sharma K, Ahmed F, Sharma T, Grover A, Agarwal M, Grover S. Potential Repurposed Drug Candidates for Tuberculosis Treatment: Progress and Update of Drugs Identified in Over a Decade. ACS OMEGA 2023; 8:17362-17380. [PMID: 37251185 PMCID: PMC10210030 DOI: 10.1021/acsomega.2c05511] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 12/23/2022] [Indexed: 05/31/2023]
Abstract
The devastating impact of Tuberculosis (TB) has been a menace to mankind for decades. The World Health Organization (WHO) End TB Strategy aims to reduce TB mortality up to 95% and 90% of overall TB cases worldwide, by 2035. This incessant urge will be achieved with a breakthrough in either a new TB vaccine or novel drugs with higher efficacy. However, the development of novel drugs is a laborious process involving a timeline of almost 20-30 years with huge expenditure; on the other hand, repurposing previously approved drugs is a viable technique for overcoming current bottlenecks in the identification of new anti-TB agents. The present comprehensive review discusses the progress of almost all the repurposed drugs that have been identified to the present day (∼100) and are in the development or clinical testing phase against TB. We have also emphasized the efficacy of repurposed drugs in combination with already available frontline anti-TB medications along with the scope of future investigations. This study would provide the researchers a detailed overview of nearly all identified anti-TB repurposed drugs and may assist them in selecting the lead compounds for further in vivo/clinical research.
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Affiliation(s)
- Khushbu Sharma
- Department
of Molecular Medicine, Jamia Hamdard, New Delhi, 110062, India
| | - Faraz Ahmed
- Department
of Molecular Medicine, Jamia Hamdard, New Delhi, 110062, India
| | - Tarina Sharma
- New
Jersey Medical School, Rutgers, The State
University of New Jersey, Newark, New Jersey 07103, United States
| | - Abhinav Grover
- School
of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Meetu Agarwal
- Department
of Molecular Medicine, Jamia Hamdard, New Delhi, 110062, India
| | - Sonam Grover
- Department
of Molecular Medicine, Jamia Hamdard, New Delhi, 110062, India
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2
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Gonzalo X, Bielecka MK, Tezera L, Elkington P, Drobniewski F. Anti-Tuberculosis Activity of Three Carbapenems, Clofazimine and Nitazoxanide Using a Novel Ex Vivo Phenotypic Drug Susceptibility Model of Human Tuberculosis. Antibiotics (Basel) 2022; 11:antibiotics11101274. [PMID: 36289932 PMCID: PMC9598577 DOI: 10.3390/antibiotics11101274] [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: 08/19/2022] [Revised: 09/18/2022] [Accepted: 09/19/2022] [Indexed: 11/17/2022] Open
Abstract
We evaluated a novel physiological 3-D bioelectrospray model of the tuberculosis (TB) granuloma to test the activity of a known anti-TB drug, clofazimine; three carbapenems with potential activity, including one currently used in therapy; and nitazoxanide, an anti-parasitic compound with possible TB activity (all chosen as conventional drug susceptibility was problematical). PBMCs collected from healthy donors were isolated and infected with M. tuberculosis H37Rv lux (i.e., luciferase). Microspheres were generated with the infected cells; the anti-microbial compounds were added and bacterial luminescence was monitored for at least 21 days. Clavulanate was added to each carbapenem to inhibit beta-lactamases. M. tuberculosis (MTB) killing efficacy was dose dependent. Clofazimine was the most effective drug inhibiting MTB growth at 2 mg/L with good killing activity at both concentrations tested. It was the only drug that killed bacteria at the lowest concentration tested. Carbapenems showed modest initial activity that was lost at around day 10 of incubation and clavulanate did not increase killing activity. Of the carbapenems tested, tebipenem was the most efficient in killing MTB, albeit at a high concentration. Nitazoxanide was effective only at concentrations not achievable with current dosing (although this might partly have been an artefact related to extensive protein binding).
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Affiliation(s)
- Ximena Gonzalo
- Department of Infectious Diseases, Faculty of Medicine, Imperial College, London W12 0NN, UK
| | - Magdalena K. Bielecka
- NIHR Respiratory Biomedical Research Unit, Clinical and Experimental Sciences Academic Unit, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Liku Tezera
- NIHR Respiratory Biomedical Research Unit, Clinical and Experimental Sciences Academic Unit, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Paul Elkington
- NIHR Respiratory Biomedical Research Unit, Clinical and Experimental Sciences Academic Unit, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Francis Drobniewski
- Department of Infectious Diseases, Faculty of Medicine, Imperial College, London W12 0NN, UK
- Correspondence:
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3
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Overcoming the Prokaryote/Eukaryote Barrier in Tuberculosis Treatment: A Prospect for the Repurposing and Use of Antiparasitic Drugs. Microorganisms 2021; 9:microorganisms9112335. [PMID: 34835459 PMCID: PMC8622410 DOI: 10.3390/microorganisms9112335] [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] [Received: 10/18/2021] [Revised: 11/07/2021] [Accepted: 11/09/2021] [Indexed: 11/17/2022] Open
Abstract
Antimicrobial resistance, the so-called silent pandemic, is pushing industry and academia to find novel antimicrobial agents with new mechanisms of action in order to be active against susceptible and drug-resistant microorganisms. In the case of tuberculosis, the need of novel anti-tuberculosis drugs is specially challenging because of the intricate biology of its causative agent, Mycobacterium tuberculosis. The repurposing of medicines has arisen in recent years as a fast, low-cost, and efficient strategy to identify novel biomedical applications for already approved drugs. This review is focused on anti-parasitic drugs that have additionally demonstrated certain levels of anti-tuberculosis activity; along with this, natural products with a dual activity against parasites and against M. tuberculosis are discussed. A few clinical trials have tested antiparasitic drugs in tuberculosis patients, and have revealed effective dose and toxicity issues, which is consistent with the natural differences between tuberculosis and parasitic infections. However, through medicinal chemistry approaches, derivatives of drugs with anti-parasitic activity have become successful drugs for use in tuberculosis therapy. In summary, even when the repurposing of anti-parasitic drugs for tuberculosis treatment does not seem to be an easy job, it deserves attention as a potential contributor to fuel the anti-tuberculosis drug pipeline.
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4
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Smyth R, Sun J. Protein Kinase R in Bacterial Infections: Friend or Foe? Front Immunol 2021; 12:702142. [PMID: 34305942 PMCID: PMC8297547 DOI: 10.3389/fimmu.2021.702142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/28/2021] [Indexed: 12/28/2022] Open
Abstract
The global antimicrobial resistance crisis poses a significant threat to humankind in the coming decades. Challenges associated with the development of novel antibiotics underscore the urgent need to develop alternative treatment strategies to combat bacterial infections. Host-directed therapy is a promising new therapeutic strategy that aims to boost the host immune response to bacteria rather than target the pathogen itself, thereby circumventing the development of antibiotic resistance. However, host-directed therapy depends on the identification of druggable host targets or proteins with key functions in antibacterial defense. Protein Kinase R (PKR) is a well-characterized human kinase with established roles in cancer, metabolic disorders, neurodegeneration, and antiviral defense. However, its role in antibacterial defense has been surprisingly underappreciated. Although the canonical role of PKR is to inhibit protein translation during viral infection, this kinase senses and responds to multiple types of cellular stress by regulating cell-signaling pathways involved in inflammation, cell death, and autophagy – mechanisms that are all critical for a protective host response against bacterial pathogens. Indeed, there is accumulating evidence to demonstrate that PKR contributes significantly to the immune response to a variety of bacterial pathogens. Importantly, there are existing pharmacological modulators of PKR that are well-tolerated in animals, indicating that PKR is a feasible target for host-directed therapy. In this review, we provide an overview of immune cell functions regulated by PKR and summarize the current knowledge on the role and functions of PKR in bacterial infections. We also review the non-canonical activators of PKR and speculate on the potential mechanisms that trigger activation of PKR during bacterial infection. Finally, we provide an overview of existing pharmacological modulators of PKR that could be explored as novel treatment strategies for bacterial infections.
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Affiliation(s)
- Robin Smyth
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Jim Sun
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada.,Centre for Infection, Immunity and Inflammation, University of Ottawa, Ottawa, ON, Canada
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5
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Wipperman MF, Bhattarai SK, Vorkas CK, Maringati VS, Taur Y, Mathurin L, McAulay K, Vilbrun SC, Francois D, Bean J, Walsh KF, Nathan C, Fitzgerald DW, Glickman MS, Bucci V. Gastrointestinal microbiota composition predicts peripheral inflammatory state during treatment of human tuberculosis. Nat Commun 2021; 12:1141. [PMID: 33602926 PMCID: PMC7892575 DOI: 10.1038/s41467-021-21475-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 01/21/2021] [Indexed: 12/15/2022] Open
Abstract
The composition of the gastrointestinal microbiota influences systemic immune responses, but how this affects infectious disease pathogenesis and antibiotic therapy outcome is poorly understood. This question is rarely examined in humans due to the difficulty in dissociating the immunologic effects of antibiotic-induced pathogen clearance and microbiome alteration. Here, we analyze data from two longitudinal studies of tuberculosis (TB) therapy (35 and 20 individuals) and a cross sectional study from 55 healthy controls, in which we collected fecal samples (for microbiome analysis), sputum (for determination of Mycobacterium tuberculosis (Mtb) bacterial load), and peripheral blood (for transcriptomic analysis). We decouple microbiome effects from pathogen sterilization by comparing standard TB therapy with an experimental TB treatment that did not reduce Mtb bacterial load. Random forest regression to the microbiome-transcriptome-sputum data from the two longitudinal datasets reveals that renormalization of the TB inflammatory state is associated with Mtb pathogen clearance, increased abundance of Clusters IV and XIVa Clostridia, and decreased abundance of Bacilli and Proteobacteria. We find similar associations when applying machine learning to peripheral gene expression and microbiota profiling in the independent cohort of healthy individuals. Our findings indicate that antibiotic-induced reduction in pathogen burden and changes in the microbiome are independently associated with treatment-induced changes of the inflammatory response of active TB, and the response to antibiotic therapy may be a combined effect of pathogen killing and microbiome driven immunomodulation. Antibiotic therapy can lead to pathogen clearance, but also to alterations in the gut microbiota and systemic immune responses. Here, the authors analyze data from patients with tuberculosis and healthy subjects to show that pathogen clearance and gut microbiota alterations are independently associated with antibiotic-induced changes of the inflammatory response of active tuberculosis.
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Affiliation(s)
- Matthew F Wipperman
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.,Clinical and Translational Science Center, Weill Cornell Medicine, New York, NY, USA
| | - Shakti K Bhattarai
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA
| | - Charles Kyriakos Vorkas
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.,Division of Infectious Diseases, Weill Cornell Medicine, New York, NY, USA
| | - Venkata Suhas Maringati
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA
| | - Ying Taur
- Division of Infectious Diseases, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Laurent Mathurin
- Haitian Study Group for Kaposi's Sarcoma and Opportunistic Infections (GHESKIO), Port-au-Prince, Haiti
| | | | - Stalz Charles Vilbrun
- Haitian Study Group for Kaposi's Sarcoma and Opportunistic Infections (GHESKIO), Port-au-Prince, Haiti
| | - Daphie Francois
- Haitian Study Group for Kaposi's Sarcoma and Opportunistic Infections (GHESKIO), Port-au-Prince, Haiti
| | - James Bean
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Kathleen F Walsh
- Center for Global Health, Weill Cornell Medicine, New York, NY, USA
| | - Carl Nathan
- Immunology and Microbial Pathogenesis Graduate Program, Weill Cornell Graduate School, New York, NY, USA
| | | | - Michael S Glickman
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA. .,Division of Infectious Diseases, Weill Cornell Medicine, New York, NY, USA. .,Immunology and Microbial Pathogenesis Graduate Program, Weill Cornell Graduate School, New York, NY, USA.
| | - Vanni Bucci
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA. .,Center for Microbiome Research, University of Massachusetts Medical School, Worcester, MA, USA. .,Program in Systems Biology, University of Massachusetts Medical School, Worcester, MA, USA.
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6
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Hasenoehrl EJ, Wiggins TJ, Berney M. Bioenergetic Inhibitors: Antibiotic Efficacy and Mechanisms of Action in Mycobacterium tuberculosis. Front Cell Infect Microbiol 2021; 10:611683. [PMID: 33505923 PMCID: PMC7831573 DOI: 10.3389/fcimb.2020.611683] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/23/2020] [Indexed: 11/23/2022] Open
Abstract
Development of novel anti-tuberculosis combination regimens that increase efficacy and reduce treatment timelines will improve patient compliance, limit side-effects, reduce costs, and enhance cure rates. Such advancements would significantly improve the global TB burden and reduce drug resistance acquisition. Bioenergetics has received considerable attention in recent years as a fertile area for anti-tuberculosis drug discovery. Targeting the electron transport chain (ETC) and oxidative phosphorylation machinery promises not only to kill growing cells but also metabolically dormant bacilli that are inherently more drug tolerant. Over the last two decades, a broad array of drugs targeting various ETC components have been developed. Here, we provide a focused review of the current state of art of bioenergetic inhibitors of Mtb with an in-depth analysis of the metabolic and bioenergetic disruptions caused by specific target inhibition as well as their synergistic and antagonistic interactions with other drugs. This foundation is then used to explore the reigning theories on the mechanisms of antibiotic-induced cell death and we discuss how bioenergetic inhibitors in particular fail to be adequately described by these models. These discussions lead us to develop a clear roadmap for new lines of investigation to better understand the mechanisms of action of these drugs with complex mechanisms as well as how to leverage that knowledge for the development of novel, rationally-designed combination therapies to cure TB.
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Affiliation(s)
- Erik J Hasenoehrl
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Thomas J Wiggins
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Michael Berney
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, United States
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7
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Tetali SR, Kunapaeddi E, Mailavaram RP, Singh V, Borah P, Deb PK, Venugopala KN, Hourani W, Tekade RK. Current advances in the clinical development of anti-tubercular agents. Tuberculosis (Edinb) 2020; 125:101989. [PMID: 32957054 DOI: 10.1016/j.tube.2020.101989] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/27/2020] [Accepted: 08/31/2020] [Indexed: 12/20/2022]
Abstract
Tuberculosis (TB) is a communicable airborne infectious disease caused by the Mycobacterium tuberculosis (MTB) that primarily affects the lungs, and can disseminate to other parts of the body. MTB is one of the most dangerous pathogens, killing about 1.4 million people annually worldwide. Although the standard treatment of TB is comprised of four anti-TB drugs, the emergence of multidrug-resistant (MDR) and extensive drug-resistant (XDR) strains in the recent past and associated side effects have affected the tailor-made regimens. Notably, existing therapies approved by the World Health Organisation (WHO) can only treat less than 50% of drug-resistant TB. Therefore, an expeditious pace in the TB research is highly needed in search of effective, affordable, least toxic novel drugs with shorter regimens to reach the goals viz. 2020 milestones End TB strategy set by the WHO. Currently, twenty-three drug-like molecules are under investigation in different stages of clinical trials. These newer agents are expected to be effective against the resistant strains. This article summarizes the properties, merits, demerits, and the probability of their success as novel potential therapeutic agents.
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Affiliation(s)
- Samanvai Reddy Tetali
- Department of Pharmaceutical Chemistry, Shri Vishnu College of Pharmacy, Vishnupur, Bhimavaram, 534 202, West Godavari Dist., Andhra Pradesh, India
| | - Eswar Kunapaeddi
- Department of Pharmaceutical Chemistry, Shri Vishnu College of Pharmacy, Vishnupur, Bhimavaram, 534 202, West Godavari Dist., Andhra Pradesh, India
| | - Raghu Prasad Mailavaram
- Department of Pharmaceutical Chemistry, Shri Vishnu College of Pharmacy, Vishnupur, Bhimavaram, 534 202, West Godavari Dist., Andhra Pradesh, India.
| | - Vinayak Singh
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch, 7701, South Africa; South African Medical Research Council Drug Discovery and Development Research Unit, Department of Chemistry and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch, 7701, South Africa
| | - Pobitra Borah
- Pratiksha Institute of Pharmaceutical Sciences, Chandrapur Road, Panikhaiti, Guwahati, 781026, Assam, India
| | - Pran Kishore Deb
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, Philadelphia University, PO Box 1, Amman, 19392, Jordan.
| | - Katharigatta N Venugopala
- Department of Pharmaceutical Sciences, College of Clinical Pharmacy, King Faisal University, Al-Ahsa, 31982, Saudi Arabia; Department of Biotechnology and Food Technology, Durban University of Technology, Durban, 4001, South Africa
| | - Wafa Hourani
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, Philadelphia University, PO Box 1, Amman, 19392, Jordan
| | - Rakesh Kumar Tekade
- National Institute of Pharmaceutical Education and Research-Ahmedabad (NIPER-A), Opposite Air Force Station Palaj, Gandhinagar, 382355, Gujarat, India
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8
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Early Bactericidal Activity Trial of Nitazoxanide for Pulmonary Tuberculosis. Antimicrob Agents Chemother 2020; 64:AAC.01956-19. [PMID: 32071052 DOI: 10.1128/aac.01956-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 02/06/2020] [Indexed: 01/24/2023] Open
Abstract
This study was conducted in treatment-naive adults with drug-susceptible pulmonary tuberculosis in Port-au-Prince, Haiti, to assess the safety, bactericidal activity, and pharmacokinetics of nitazoxanide (NTZ). This was a prospective phase II clinical trial in 30 adults with pulmonary tuberculosis. Twenty participants received 1 g of NTZ orally twice daily for 14 days. A control group of 10 participants received standard therapy over 14 days. The primary outcome was the change in time to culture positivity (TTP) in an automated liquid culture system. The most common adverse events seen in the NTZ group were gastrointestinal complaints and headache. The mean change in TTP in sputum over 14 days in the NTZ group was 3.2 h ± 22.6 h and was not statistically significant (P = 0.56). The mean change in TTP in the standard therapy group was significantly increased, at 134 h ± 45.2 h (P < 0.0001). The mean NTZ MIC for Mycobacterium tuberculosis isolates was 12.3 μg/ml; the mean NTZ maximum concentration (C max) in plasma was 10.2 μg/ml. Negligible NTZ levels were measured in sputum. At the doses used, NTZ did not show bactericidal activity against M. tuberculosis Plasma concentrations of NTZ were below the MIC, and its negligible accumulation in pulmonary sites may explain the lack of bactericidal activity. (This study has been registered at ClinicalTrials.gov under identifier NCT02684240.).
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9
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New drugs to treat difficult tuberculous and nontuberculous mycobacterial pulmonary disease. Curr Opin Pulm Med 2020; 25:271-280. [PMID: 30865034 DOI: 10.1097/mcp.0000000000000570] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
PURPOSE OF REVIEW Treatment of drug-sensitive tuberculosis (TB) is effective, whereas that of multidrug-resistant and extensively drug-resistant TB as well as nontuberculous mycobacterial (NTM) disease are less so. Therapy in general requires good adherence to potentially toxic drug regimens over prolonged periods. Poor adherence is associated with resistance development and poor outcome. This review will present promising new treatments, both new drugs and regimens, for difficult mycobacterial pulmonary infections. RECENT FINDINGS A number of new and repurposed drugs including bedaquiline, delamanid, pretomanid, linezolid and clofazimine, and drug regimens, such as the The Evaluation of a Standard Treatment Regimen of Anti-tuberculosis Drugs for Patients With MDR-TB (STREAM) trial regimens, are currently progressing from basic research through clinical trials. SUMMARY
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Ranjbar S, Haridas V, Nambu A, Jasenosky LD, Sadhukhan S, Ebert TS, Hornung V, Cassell GH, Falvo JV, Goldfeld AE. Cytoplasmic RNA Sensor Pathways and Nitazoxanide Broadly Inhibit Intracellular Mycobacterium tuberculosis Growth. iScience 2019; 22:299-313. [PMID: 31805434 PMCID: PMC6909047 DOI: 10.1016/j.isci.2019.11.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 10/02/2019] [Accepted: 10/30/2019] [Indexed: 02/06/2023] Open
Abstract
To establish stable infection, Mycobacterium tuberculosis (MTb) must overcome host innate immune mechanisms, including those that sense pathogen-derived nucleic acids. Here, we show that the host cytosolic RNA sensing molecules RIG-I-like receptor (RLR) signaling proteins RIG-I and MDA5, their common adaptor protein MAVS, and the RNA-dependent kinase PKR each independently inhibit MTb growth in human cells. Furthermore, we show that MTb broadly stimulates RIG-I, MDA5, MAVS, and PKR gene expression and their biological activities. We also show that the oral FDA-approved drug nitazoxanide (NTZ) significantly inhibits intracellular MTb growth and amplifies MTb-stimulated RNA sensor gene expression and activity. This study establishes prototypic cytoplasmic RNA sensors as innate restriction factors for MTb growth in human cells and it shows that targeting this pathway is a potential host-directed approach to treat tuberculosis disease. MTb infection induces RNA sensor (RIG-I, MDA5, PKR) mRNA levels and activities RIG-I, MDA5, MAVS, and PKR restrict intracellular MTb growth in human cells NTZ enhances MTb-driven RNA sensor mRNA levels and RLR activities NTZ and NTZ derivatives inhibit intracellular MTb growth in primary human cells
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Affiliation(s)
- Shahin Ranjbar
- Program in Cellular and Molecular Medicine, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA
| | - Viraga Haridas
- Program in Cellular and Molecular Medicine, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA
| | - Aya Nambu
- Program in Cellular and Molecular Medicine, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA
| | - Luke D Jasenosky
- Program in Cellular and Molecular Medicine, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA
| | - Supriya Sadhukhan
- Program in Cellular and Molecular Medicine, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA
| | - Thomas S Ebert
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Veit Hornung
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Gail H Cassell
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - James V Falvo
- Program in Cellular and Molecular Medicine, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA
| | - Anne E Goldfeld
- Program in Cellular and Molecular Medicine, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA.
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11
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J Libardo MD, Boshoff HI, Barry CE. The present state of the tuberculosis drug development pipeline. Curr Opin Pharmacol 2018; 42:81-94. [PMID: 30144650 DOI: 10.1016/j.coph.2018.08.001] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/27/2018] [Accepted: 08/01/2018] [Indexed: 10/28/2022]
Abstract
Tuberculosis now ranks as the leading cause of death in the world due to a single infectious agent. Current standard of care treatment can achieve very high cure rates for drug-sensitive disease but requires a 6-month duration of chemotherapy. Drug-resistant disease requires significantly longer treatment durations with drugs associated with a higher risk of adverse events. Thus, there is a pressing need for a drug regimen that is safer, shorter in duration and superior to current front-line chemotherapy in terms of efficacy. The TB drug pipeline contains several candidates that address one or more of the required attributes of chemotherapeutic regimens that may redefine the standard of care of this disease. Several new drugs have been reported and novel targets have been identified allowing regimens containing new compounds to trickle into clinical studies. Furthermore, a recent paradigm-shift in understanding the pharmacokinetics of anti-tubercular drugs is revolutionizing the way we select compounds for clinical progression.
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Affiliation(s)
- M Daben J Libardo
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, United States
| | - Helena Im Boshoff
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, United States
| | - Clifton E Barry
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, United States.
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12
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Machado D, Girardini M, Viveiros M, Pieroni M. Challenging the Drug-Likeness Dogma for New Drug Discovery in Tuberculosis. Front Microbiol 2018; 9:1367. [PMID: 30018597 PMCID: PMC6037898 DOI: 10.3389/fmicb.2018.01367] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 06/06/2018] [Indexed: 01/28/2023] Open
Abstract
The emergence of multi- and extensively drug resistant tuberculosis worldwide poses a great threat to human health and highlight the need to discover and develop new, effective and inexpensive antituberculosis agents. High-throughput screening assays against well-validated drug targets and structure based drug design have been employed to discover new lead compounds. However, the great majority fail to demonstrate any antimycobacterial activity when tested against Mycobacterium tuberculosis in whole-cell screening assays. This is mainly due to some of the intrinsic properties of the bacilli, such as the extremely low permeability of its cell wall, slow growth, drug resistance, drug tolerance, and persistence. In this sense, understanding the pathways involved in M. tuberculosis drug tolerance, persistence, and pathogenesis, may reveal new approaches for drug development. Moreover, the need for compounds presenting a novel mode of action is of utmost importance due to the emergence of resistance not only to the currently used antituberculosis agents, but also to those in the pipeline. Cheminformatics studies have shown that drugs endowed with antituberculosis activity have the peculiarity of being more lipophilic than many other antibacterials, likely because this leads to improved cell penetration through the extremely waxy mycobacterial cell wall. Moreover, the interaction of the lipophilic moiety with the membrane alters its stability and functional integrity due to the disruption of the proton motive force, resulting in cell death. When a ligand-based medicinal chemistry campaign is ongoing, it is always difficult to predict whether a chemical modification or a functional group would be suitable for improving the activity. Nevertheless, in the “instruction manual” of medicinal chemists, certain functional groups or certain physicochemical characteristics (i.e., high lipophilicity) are considered red flags to look out for in order to safeguard drug-likeness and avoid attritions in the drug discovery process. In this review, we describe how antituberculosis compounds challenge established rules such as the Lipinski's “rule of five” and how medicinal chemistry for antituberculosis compounds must be thought beyond such dogmatic schemes.
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Affiliation(s)
- Diana Machado
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Lisbon, Portugal
| | - Miriam Girardini
- P4T Group, Department of Food and Drug, University of Parma, Parma, Italy
| | - Miguel Viveiros
- Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Lisbon, Portugal
| | - Marco Pieroni
- P4T Group, Department of Food and Drug, University of Parma, Parma, Italy
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13
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Abstract
There
is a large, global unmet need for the development of countermeasures
to combat intracellular pathogens. The development of novel antimicrobials
is expensive and slow and typically focuses on selective inhibition
of proteins encoded by a single pathogen, thereby providing a narrow
spectrum of coverage. The repurposing of approved drugs targeting
host functions required for microbial infections represents a promising
alternative. This review summarizes progress and challenges in the
repurposing of approved drugs as host-targeted broad-spectrum agents
for the treatment of intracellular pathogens. These strategies include
targeting both cellular factors required for infection by various
viruses, intracellular bacteria, and/or protozoa as well as factors
that modulate the host immune response to these microbial infections.
The repurposed approach offers complementary means to develop therapeutics
against existing and emerging intracellular microbial threats.
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Affiliation(s)
- Stanford Schor
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, and Department of Microbiology and Immunology, School of Medicine, Stanford University, 300 Pasteur Drive, Lane Building Rm L127, Stanford, California 94305, United States
| | - Shirit Einav
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, and Department of Microbiology and Immunology, School of Medicine, Stanford University, 300 Pasteur Drive, Lane Building Rm L127, Stanford, California 94305, United States
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14
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Cavanaugh JS, Jou R, Wu MH, Dalton T, Kurbatova E, Ershova J, Cegielski JP. Susceptibilities of MDR Mycobacterium tuberculosis isolates to unconventional drugs compared with their reported pharmacokinetic/pharmacodynamic parameters. J Antimicrob Chemother 2017; 72:1678-1687. [PMID: 28333192 DOI: 10.1093/jac/dkx022] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 01/12/2017] [Indexed: 12/21/2022] Open
Abstract
Background The second-line drugs recommended to treat drug-resistant TB are toxic, expensive and difficult to procure. Given increasing resistance, the need for additional anti-TB drugs has become more urgent. But new drugs take time to develop and are expensive. Some commercially available drugs have reported anti-mycobacterial activity but are not routinely used because supporting laboratory and clinical evidence is sparse. Methods We analysed 217 MDR M. tuberculosis isolates including 153 initial isolates from unique patients and 64 isolates from follow-up specimens during the course of treatment. The resazurin microdilution assay was performed to determine MICs of trimethoprim/sulfamethoxazole, mefloquine, thioridazine, clofazimine, amoxicillin/clavulanate, meropenem/clavulanate, nitazoxanide, linezolid and oxyphenbutazone. Isoniazid was used for validation. We calculated the MIC 50 and MIC 90 as the MICs at which growth of 50% and 90% of isolates was inhibited, respectively. Results The MIC 50 s, in mg/L, for initial isolates were as follows: trimethoprim/sulfamethoxazole, 0.2/4; mefloquine, 8; thioridazine, 4; clofazimine, 0.25; amoxicillin/clavulanate, 16/8; meropenem/clavulanate, 1/2.5; nitazoxanide, 16; linezolid, 0.25; and oxyphenbutazone, 40. The MIC 90 s, in mg/L, for initial isolates were as follows: trimethoprim/sulfamethoxazole, 0.4/8; mefloquine, 8; thioridazine, 8; clofazimine, 0.5; amoxicillin/clavulanate, 32/16; meropenem/clavulanate, 8/2.5; nitazoxanide, 16; linezolid, 0.25; and oxyphenbutazone, 60. By comparison, the MIC 90 of isoniazid was >4 mg/L, as expected. There was no evidence that previous treatment affected susceptibility to any drug. Conclusions Most drugs demonstrated efficacy against M. tuberculosis . When these MICs are compared with the published pharmacokinetic/pharmacodynamic profiles of the respective drugs in humans, trimethoprim/sulfamethoxazole, meropenem/clavulanate, linezolid, clofazimine and nitazoxanide appear promising and warrant further clinical investigation.
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Affiliation(s)
- Joseph S Cavanaugh
- United States Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Ruwen Jou
- Taiwan Centers for Disease Control, Taipei, Taiwan, Republic of China
| | - Mei-Hua Wu
- Taiwan Centers for Disease Control, Taipei, Taiwan, Republic of China
| | - Tracy Dalton
- United States Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Julia Ershova
- United States Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - J Peter Cegielski
- United States Centers for Disease Control and Prevention, Atlanta, GA, USA
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15
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Abstract
Nitazoxanide (NTZ) is an anti-parasitic drug that also has activity against bacteria, including Mycobacterium tuberculosis. Our data using both radiorespirometry and live-dead staining in vitro demonstrate that NTZ similarly has bactericidal against M. leprae. Further, gavage of M. leprae-infected mice with NTZ at 25mg/kg provided anti-mycobacterial activity equivalent to rifampicin (RIF) at 10 mg/kg. This suggests that NTZ could be considered for leprosy treatment.
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16
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Rifamycin action on RNA polymerase in antibiotic-tolerant Mycobacterium tuberculosis results in differentially detectable populations. Proc Natl Acad Sci U S A 2017; 114:E4832-E4840. [PMID: 28559332 DOI: 10.1073/pnas.1705385114] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) encounters stresses during the pathogenesis and treatment of tuberculosis (TB) that can suppress replication of the bacteria and render them phenotypically tolerant to most available drugs. Where studied, the majority of Mtb in the sputum of most untreated subjects with active TB have been found to be nonreplicating by the criterion that they do not grow as colony-forming units (cfus) when plated on agar. However, these cells are viable because they grow when diluted in liquid media. A method for generating such "differentially detectable" (DD) Mtb in vitro would aid studies of the biology and drug susceptibility of this population, but lack of independent confirmation of reported methods has contributed to skepticism about their existence. Here, we identified confounding artifacts that, when avoided, allowed development of a reliable method of producing cultures of ≥90% DD Mtb in starved cells. We then characterized several drugs according to whether they contribute to the generation of DD Mtb or kill them. Of the agents tested, rifamycins led to DD Mtb generation, an effect lacking in a rifampin-resistant strain with a mutation in rpoB, which encodes the canonical rifampin target, the β subunit of RNA polymerase. In contrast, thioridazine did not generate DD Mtb from starved cells but killed those generated by rifampin.
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17
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Gupta A, Tulsankar SL, Bhatta RS, Misra A. Pharmacokinetics, Metabolism, and Partial Biodistribution of “Pincer Therapeutic” Nitazoxanide in Mice following Pulmonary Delivery of Inhalable Particles. Mol Pharm 2017; 14:1204-1211. [DOI: 10.1021/acs.molpharmaceut.6b01089] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Anuradha Gupta
- CSIR-Central Drug Research Institute, Sector 10A, Janakipuram Extension, Mohiuddinpur, Lucknow 226031, India
| | - Sachin L. Tulsankar
- CSIR-Central Drug Research Institute, Sector 10A, Janakipuram Extension, Mohiuddinpur, Lucknow 226031, India
| | - Rabi S. Bhatta
- CSIR-Central Drug Research Institute, Sector 10A, Janakipuram Extension, Mohiuddinpur, Lucknow 226031, India
| | - Amit Misra
- CSIR-Central Drug Research Institute, Sector 10A, Janakipuram Extension, Mohiuddinpur, Lucknow 226031, India
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18
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Gupta A, Meena J, Sharma D, Gupta P, Gupta UD, Kumar S, Sharma S, Panda AK, Misra A. Inhalable Particles for "Pincer Therapeutics" Targeting Nitazoxanide as Bactericidal and Host-Directed Agent to Macrophages in a Mouse Model of Tuberculosis. Mol Pharm 2016; 13:3247-55. [PMID: 27463245 DOI: 10.1021/acs.molpharmaceut.6b00459] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Nitazoxanide (NTZ) has moderate mycobactericidal activity and is also an inducer of autophagy in mammalian cells. High-payload (40-50% w/w) inhalable particles containing NTZ alone or in combination with antituberculosis (TB) agents isoniazid (INH) and rifabutin (RFB) were prepared with high incorporation efficiency of 92%. In vitro drug release was corrected for drug degradation during the course of study and revealed first-order controlled release. Particles were efficiently taken up in vitro by macrophages and maintained intracellular drug concentrations at one order of magnitude higher than NTZ in solution for 6 h. Dose-dependent killing of Mtb and restoration of lung and spleen architecture were observed in experimentally infected mice treated with inhalations containing NTZ. Adjunct NTZ with INH and RFB cleared culturable bacteria from the lung and spleen and markedly healed tissue architecture. NTZ can be used in combination with INH-RFB to kill the pathogen and heal the host.
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Affiliation(s)
- Anuradha Gupta
- CSIR-Central Drug Research Institute , Lucknow 226031, India
| | - Jairam Meena
- National Institute of Immunology , New Delhi 110067, India
| | - Deepak Sharma
- CSIR-Central Drug Research Institute , Lucknow 226031, India
| | - Pushpa Gupta
- National JALMA Institute for Leprosy and Other Mycobacterial Diseases (ICMR) , Agra 282001, India
| | - Umesh Dutta Gupta
- National JALMA Institute for Leprosy and Other Mycobacterial Diseases (ICMR) , Agra 282001, India
| | - Sadan Kumar
- CSIR-Central Drug Research Institute , Lucknow 226031, India
| | - Sharad Sharma
- CSIR-Central Drug Research Institute , Lucknow 226031, India
| | - Amulya K Panda
- National Institute of Immunology , New Delhi 110067, India
| | - Amit Misra
- CSIR-Central Drug Research Institute , Lucknow 226031, India
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19
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Harausz EP, Chervenak KA, Good CE, Jacobs MR, Wallis RS, Sanchez-Felix M, Boom WH. Activity of nitazoxanide and tizoxanide against Mycobacterium tuberculosis in vitro and in whole blood culture. Tuberculosis (Edinb) 2016; 98:92-6. [PMID: 27156623 DOI: 10.1016/j.tube.2016.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 03/08/2016] [Accepted: 03/15/2016] [Indexed: 11/18/2022]
Abstract
Nitazoxanide (NTZ) and its metabolite tizoxanide (TIZ) were studied as antimycobacterial agents in vitro (in mycobacterial growth indicator tube [MGIT] cultures) and in a whole blood bactericidal assay. Both NTZ and TIZ show high protein binding. In MGIT cultures (albumin concentration = 78 μM), inhibition of Mycobacterium tuberculosis growth occurred at total drug concentrations of ≥16 μg/ml, whereas in whole blood cultures (albumin concentration = 350 μM), ≥128 μg/ml was required. Free drug fractions at these two conditions were estimated to be 69% and 2%, respectively. Co-incubation of NTZ and TIZ in human plasma for 72 h nearly completely eliminated their ability to inhibit mycobacterial growth in MGIT. Interactions with plasma proteins may limit the potential of NTZ and TIZ as drugs for human tuberculosis.
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Affiliation(s)
- Elizabeth P Harausz
- Department of Medicine, Case Western Reserve University, University Hospitals Case Medical Center, 10900 Euclid Ave, Cleveland, OH 44106, USA.
| | - Keith A Chervenak
- Department of Medicine, Case Western Reserve University, University Hospitals Case Medical Center, 10900 Euclid Ave, Cleveland, OH 44106, USA.
| | - Caryn E Good
- Department of Pathology, Case Western Reserve University, University Hospitals Case Medical Center, 10900 Euclid Ave, Cleveland, OH 44106, USA.
| | - Michael R Jacobs
- Department of Pathology, Case Western Reserve University, University Hospitals Case Medical Center, 10900 Euclid Ave, Cleveland, OH 44106, USA.
| | - Robert S Wallis
- Aurum Institute, 29 Queens Rd, Parktown, Johannesburg, South Africa.
| | | | - W Henry Boom
- Department of Medicine, Case Western Reserve University, University Hospitals Case Medical Center, 10900 Euclid Ave, Cleveland, OH 44106, USA.
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20
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Maitra A, Bates S, Kolvekar T, Devarajan PV, Guzman JD, Bhakta S. Repurposing-a ray of hope in tackling extensively drug resistance in tuberculosis. Int J Infect Dis 2016; 32:50-5. [PMID: 25809756 DOI: 10.1016/j.ijid.2014.12.031] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Revised: 12/11/2014] [Accepted: 12/16/2014] [Indexed: 12/23/2022] Open
Abstract
Tuberculosis (TB) remains a serious concern more than two decades on from when the World Health Organization declared it a global health emergency. The alarming rise of antibiotic resistance in Mycobacterium tuberculosis, the etiological agent of TB, has made it exceedingly difficult to control the disease with the existing portfolio of anti-TB chemotherapy. The development of effective drugs with novel mechanism(s) of action is thus of paramount importance to tackle drug resistance. The development of novel chemical entities requires more than 10 years of research, requiring high-risk investment to become commercially available. Repurposing pre-existing drugs offers a solution to circumvent this mammoth investment in time and funds. In this context, several drugs with known safety and toxicity profiles have been evaluated against the TB pathogen and found to be efficacious against its different physiological states. As the endogenous targets of these drugs in the TB bacillus are most likely to be novel, there is minimal chance of cross-resistance with front-line anti-TB drugs. Also, reports that some of these drugs may potentially have multiple targets means that the possibility of the development of resistance against them is minimal. Thus repurposing existing molecules offers immense promise to tackle extensively drug-resistant TB infections.
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Affiliation(s)
- Arundhati Maitra
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, London, UK
| | - Sadé Bates
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, London, UK
| | - Trupti Kolvekar
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, London, UK
| | - Padma V Devarajan
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, N. P. Marg, Matunga, Mumbai, India
| | - Juan D Guzman
- Departamento de Química y Biología, División de Ciencias Básicas, Universidad del Norte, Barranquilla, Colombia
| | - Sanjib Bhakta
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, London, UK.
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21
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Landge S, Ramachandran V, Kumar A, Neres J, Murugan K, Sadler C, Fellows MD, Humnabadkar V, Vachaspati P, Raichurkar A, Sharma S, Ravishankar S, Guptha S, Sambandamurthy VK, Balganesh TS, Ugarkar BG, Balasubramanian V, Bandodkar BS, Panda M. Nitroarenes as Antitubercular Agents: Stereoelectronic Modulation to Mitigate Mutagenicity. ChemMedChem 2016; 11:331-9. [PMID: 26751718 DOI: 10.1002/cmdc.201500462] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Indexed: 12/23/2022]
Abstract
Nitroarenes are less preferred in drug discovery due to their potential to be mutagenic. However, several nitroarenes were shown to be promising antitubercular agents with specific modes of action, namely, nitroimidazoles and benzothiazinones. The nitro group in these compounds is activated through different mechanisms, both enzymatic and non-enzymatic, in mycobacteria prior to binding to the target of interest. From a whole-cell screening program, we identified a novel lead nitrobenzothiazole (BT) series that acts by inhibition of decaprenylphosphoryl-β-d-ribose 2'-epimerase (DprE1) of Mycobacterium tuberculosis (Mtb). The lead was found to be mutagenic to start with. Our efforts to mitigate mutagenicity resulted in the identification of 6-methyl-7-nitro-5-(trifluoromethyl)-1,3-benzothiazoles (cBTs), a novel class of antitubercular agents that are non-mutagenic and exhibit an improved safety profile. The methyl group ortho to the nitro group decreases the electron affinity of the series, and is hence responsible for the non-mutagenic nature of these compounds. Additionally, the co-crystal structure of cBT in complex with Mtb DprE1 established the mode of binding. This investigation led to a new non-mutagenic antitubercular agent and demonstrates that the mutagenic nature of nitroarenes can be solved by modulation of stereoelectronic properties.
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Affiliation(s)
- Sudhir Landge
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India
| | - Vasanthi Ramachandran
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India
| | - Anupriya Kumar
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India
| | - João Neres
- Global Health Institute, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Kannan Murugan
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India
| | - Claire Sadler
- iMED Safety Assessment, AstraZeneca, Alderley Park, Macclesfield, SK10 4TF, UK
| | - Mick D Fellows
- iMED Safety Assessment, AstraZeneca, Alderley Park, Macclesfield, SK10 4TF, UK
| | - Vaishali Humnabadkar
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India
| | - Prakash Vachaspati
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India
| | - Anandkumar Raichurkar
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India
| | - Sreevalli Sharma
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India
| | - Sudha Ravishankar
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India
| | - Supreeth Guptha
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India
| | - Vasan K Sambandamurthy
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India
| | - Tanjore S Balganesh
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India
| | - Bheemarao G Ugarkar
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India
| | - V Balasubramanian
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India
| | | | - Manoranjan Panda
- iMED Infection, AstraZeneca India Pvt. Ltd., Bellary Road, Hebbal, Bangalore, 560024, India. .,Biocon Bristol-Myers Squibb Research Center, Biocon Park, Jigani Link Road, Bangalore, 560099, India.
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22
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Feng X, Zhu W, Schurig-Briccio LA, Lindert S, Shoen C, Hitchings R, Li J, Wang Y, Baig N, Zhou T, Kim BK, Crick DC, Cynamon M, McCammon JA, Gennis RB, Oldfield E. Antiinfectives targeting enzymes and the proton motive force. Proc Natl Acad Sci U S A 2015; 112:E7073-82. [PMID: 26644565 PMCID: PMC4697371 DOI: 10.1073/pnas.1521988112] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
There is a growing need for new antibiotics. Compounds that target the proton motive force (PMF), uncouplers, represent one possible class of compounds that might be developed because they are already used to treat parasitic infections, and there is interest in their use for the treatment of other diseases, such as diabetes. Here, we tested a series of compounds, most with known antiinfective activity, for uncoupler activity. Many cationic amphiphiles tested positive, and some targeted isoprenoid biosynthesis or affected lipid bilayer structure. As an example, we found that clomiphene, a recently discovered undecaprenyl diphosphate synthase inhibitor active against Staphylococcus aureus, is an uncoupler. Using in silico screening, we then found that the anti-glioblastoma multiforme drug lead vacquinol is an inhibitor of Mycobacterium tuberculosis tuberculosinyl adenosine synthase, as well as being an uncoupler. Because vacquinol is also an inhibitor of M. tuberculosis cell growth, we used similarity searches based on the vacquinol structure, finding analogs with potent (∼0.5-2 μg/mL) activity against M. tuberculosis and S. aureus. Our results give a logical explanation of the observation that most new tuberculosis drug leads discovered by phenotypic screens and genome sequencing are highly lipophilic (logP ∼5.7) bases with membrane targets because such species are expected to partition into hydrophobic membranes, inhibiting membrane proteins, in addition to collapsing the PMF. This multiple targeting is expected to be of importance in overcoming the development of drug resistance because targeting membrane physical properties is expected to be less susceptible to the development of resistance.
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Affiliation(s)
- Xinxin Feng
- Department of Chemistry, University of Illinois, Urbana, IL 61801
| | - Wei Zhu
- Department of Chemistry, University of Illinois, Urbana, IL 61801
| | | | - Steffen Lindert
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH 43210
| | - Carolyn Shoen
- Central New York Research Corporation, Veterans Affairs Medical Center, Syracuse, NY 13210
| | - Reese Hitchings
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523
| | - Jikun Li
- Department of Chemistry, University of Illinois, Urbana, IL 61801
| | - Yang Wang
- Department of Chemistry, University of Illinois, Urbana, IL 61801
| | - Noman Baig
- Department of Chemistry, University of Illinois, Urbana, IL 61801
| | - Tianhui Zhou
- Department of Chemistry, University of Illinois, Urbana, IL 61801
| | - Boo Kyung Kim
- Department of Chemistry, University of Illinois, Urbana, IL 61801
| | - Dean C Crick
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523
| | - Michael Cynamon
- Central New York Research Corporation, Veterans Affairs Medical Center, Syracuse, NY 13210
| | - J Andrew McCammon
- Department of Pharmacology and Department of Chemistry & Biochemistry, University of California San Diego, La Jolla, CA 92093; Howard Hughes Medical Institute, University of California San Diego, La Jolla, CA 92093; National Biomedical Computation Resource, University of California San Diego, La Jolla, CA 92093;
| | - Robert B Gennis
- Department of Chemistry, University of Illinois, Urbana, IL 61801; Department of Biochemistry, University of Illinois, Urbana, IL 61801; Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Eric Oldfield
- Department of Chemistry, University of Illinois, Urbana, IL 61801; Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
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23
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Hawn TR, Shah JA, Kalman D. New tricks for old dogs: countering antibiotic resistance in tuberculosis with host-directed therapeutics. Immunol Rev 2015; 264:344-62. [PMID: 25703571 DOI: 10.1111/imr.12255] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Despite the availability of Mycobacterium tuberculosis (Mtb) drugs for over 50 years, tuberculosis (TB) remains at pandemic levels. New drugs are urgently needed for resistant strains, shortening duration of treatment, and targeting different stages of the disease, especially for treatment during human immunodeficiency virus co-infection. One solution to the conundrum that antibiotics kill the bacillus yet select for resistance is to target the host rather than the pathogen. Here, we discuss recent progress in so-called 'host-directed therapeutics' (HDTs), focusing on two general mechanistic strategies: (i) HDTs that disrupt Mtb pathogenesis in macrophages and (ii) immunomodulatory HDTs that facilitate protective immune responses that kill Mtb or reduce deleterious responses that exacerbate disease. HDTs hold significant promise as adjunctive therapies in that they are less likely to engender resistance, will likely have efficacy against antibiotic-resistant strains, and may have activity against non-replicating Mtb. However, TB is a complex and variegated disease, and human populations exhibit significant diversity in their immune responses to it, which presents a complicated landscape for HDTs to navigate. Nevertheless, we suggest that a detailed mechanistic understanding of drug action, together with careful selection of disease stage targets and dosing strategies may overcome such limitations and allow the development of HDTs as effective adjunctive treatment options for TB.
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Affiliation(s)
- Thomas R Hawn
- Department of Medicine, University of Washington, Seattle, WA, USA
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24
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Rapid, Semiquantitative Assay To Discriminate among Compounds with Activity against Replicating or Nonreplicating Mycobacterium tuberculosis. Antimicrob Agents Chemother 2015; 59:6521-38. [PMID: 26239979 PMCID: PMC4576094 DOI: 10.1128/aac.00803-15] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 07/31/2015] [Indexed: 01/31/2023] Open
Abstract
The search for drugs that can kill replicating and nonreplicating Mycobacterium tuberculosis faces practical bottlenecks. Measurement of CFU and discrimination of bacteriostatic from bactericidal activity are costly in compounds, supplies, labor, and time. Testing compounds against M. tuberculosis under conditions that prevent the replication of M. tuberculosis often involves a second phase of the test in which conditions are altered to permit the replication of bacteria that survived the first phase. False-positive determinations of activity against nonreplicating M. tuberculosis may arise from carryover of compounds from the nonreplicating stage of the assay that act in the replicating stage. We mitigate these problems by carrying out a 96-well microplate liquid MIC assay and then transferring an aliquot of each well to a second set of plates in which each well contains agar supplemented with activated charcoal. After 7 to 10 days—about 2 weeks sooner than required to count CFU—fluorometry reveals whether M. tuberculosis bacilli in each well have replicated extensively enough to reduce a resazurin dye added for the final hour. This charcoal agar resazurin assay (CARA) distinguishes between bacterial biomasses in any two wells that differ by 2 to 3 log10 CFU. The CARA thus serves as a pretest and semiquantitative surrogate for longer, more laborious, and expensive CFU-based assays, helps distinguish bactericidal from bacteriostatic activity, and identifies compounds that are active under replicating conditions, nonreplicating conditions, or both. Results for 14 antimycobacterial compounds, including tuberculosis (TB) drugs, revealed that PA-824 (pretomanid) and TMC207 (bedaquiline) are largely bacteriostatic.
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25
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Preclinical studies of amixicile, a systemic therapeutic developed for treatment of Clostridium difficile infections that also shows efficacy against Helicobacter pylori. Antimicrob Agents Chemother 2014; 58:4703-12. [PMID: 24890599 DOI: 10.1128/aac.03112-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Amixicile shows efficacy in the treatment of Clostridium difficile infections (CDI) in a mouse model, with no recurrence of CDI. Since amixicile selectively inhibits the action of a B vitamin (thiamine pyrophosphate) cofactor of pyruvate:ferredoxin oxidoreductase (PFOR), it may both escape mutation-based drug resistance and spare beneficial probiotic gut bacteria that do not express this enzyme. Amixicile is a water-soluble derivative of nitazoxanide (NTZ), an antiparasitic therapeutic that also shows efficacy against CDI in humans. In comparative studies, amixicile showed no toxicity to hepatocytes at 200 μM (NTZ was toxic above 10 μM); was not metabolized by human, dog, or rat liver microsomes; showed equivalence or superiority to NTZ in cytochrome P450 assays; and did not activate efflux pumps (breast cancer resistance protein, P glycoprotein). A maximum dose (300 mg/kg) of amixicile given by the oral or intraperitoneal route was well tolerated by mice and rats. Plasma exposure (rats) based on the area under the plasma concentration-time curve was 79.3 h · μg/ml (30 mg/kg dose) to 328 h · μg/ml (100 mg/kg dose), the maximum concentration of the drug in serum was 20 μg/ml, the time to the maximum concentration of the drug in serum was 0.5 to 1 h, and the half-life was 5.6 h. Amixicile did not concentrate in mouse feces or adversely affect gut populations of Bacteroides species, Firmicutes, segmented filamentous bacteria, or Lactobacillus species. Systemic bioavailability was demonstrated through eradication of Helicobacter pylori in a mouse infection model. In summary, the efficacy of amixicile in treating CDI and other infections, together with low toxicity, an absence of mutation-based drug resistance, and excellent drug metabolism and pharmacokinetic metrics, suggests a potential for broad application in the treatment of infections caused by PFOR-expressing microbial pathogens in addition to CDI.
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