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Rahmat JN, Tham SM, Ong TL, Lim YK, Patwardhan MV, Nee Mani LR, Kamaraj R, Chan YH, Chong TW, Chiong E, Esuvaranathan K, Mahendran R. Glutathione-S-Transferase Theta 2 (GSTT2) Modulates the Response to Bacillus Calmette-Guérin Immunotherapy in Bladder Cancer Patients. Int J Mol Sci 2024; 25:8947. [PMID: 39201633 PMCID: PMC11354831 DOI: 10.3390/ijms25168947] [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: 07/17/2024] [Revised: 08/11/2024] [Accepted: 08/13/2024] [Indexed: 09/02/2024] Open
Abstract
Glutathione-S-transferases (GST) enzymes detoxify xenobiotics and are implicated in response to anticancer therapy. This study evaluated the association of GST theta 1 (GSTT1), GSTT2, and GSTT2B with Mycobacterium bovis Bacillus Calmette-Guérin (BCG) response in non-muscle-invasive bladder cancer treatment. In vitro assessments of GSTT2 knockout (KO) effects were performed using cell lines and dendritic cells (DCs) from GSTT2KO mice. Deletion of GSTT2B, GSTT1, and single-nucleotide polymorphisms in the promoter region of GSTT2 was analysed in patients (n = 205) and healthy controls (n = 150). Silencing GSTT2 expression in MGH cells (GSTT2BFL/FL) resulted in increased BCG survival (p < 0.05) and decreased cellular reactive oxygen species. In our population, there are 24.2% with GSTT2BDel/Del and 24.5% with GSTT2BFL/FL. With ≤ 8 instillations of BCG therapy (n = 51), 12.5% of GSTT2BDel/Del and 53.8% of GSTT2BFL/FL patients had a recurrence (p = 0.041). With ≥9 instillations (n = 153), the disease recurred in 45.5% of GSTT2BDel/Del and 50% of GSTT2BFL/FL. GSTT2FL/FL patients had an increased likelihood of recurrence post-BCG therapy (HR 5.5 [1.87-16.69] p < 0.002). DCs from GSTT2KO mice produced three-fold more IL6 than wild-type DCs, indicating a robust inflammatory response. To summarise, GSTT2BDel/Del patients respond better to less BCG therapy and could be candidates for a reduced surveillance regimen.
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Affiliation(s)
- Juwita N. Rahmat
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore; (J.N.R.); (S.M.T.); (Y.K.L.); (M.V.P.); (L.R.N.M.); (R.K.); (K.E.)
| | - Sin Mun Tham
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore; (J.N.R.); (S.M.T.); (Y.K.L.); (M.V.P.); (L.R.N.M.); (R.K.); (K.E.)
| | - Ting Li Ong
- School of Engineering, Biomedical Engineering, Temasek Polytechnic, Singapore 529757, Singapore
| | - Yew Koon Lim
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore; (J.N.R.); (S.M.T.); (Y.K.L.); (M.V.P.); (L.R.N.M.); (R.K.); (K.E.)
| | - Mugdha Vijay Patwardhan
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore; (J.N.R.); (S.M.T.); (Y.K.L.); (M.V.P.); (L.R.N.M.); (R.K.); (K.E.)
| | - Lata Raman Nee Mani
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore; (J.N.R.); (S.M.T.); (Y.K.L.); (M.V.P.); (L.R.N.M.); (R.K.); (K.E.)
| | - Revathi Kamaraj
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore; (J.N.R.); (S.M.T.); (Y.K.L.); (M.V.P.); (L.R.N.M.); (R.K.); (K.E.)
| | - Yiong Huak Chan
- Biostatistics Unit, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore;
| | - Tsung Wen Chong
- Department of Urology, Singapore General Hospital, Singapore 169608, Singapore;
- Division of Surgery & Surgical Oncology, National Cancer Center Singapore, Singapore 168583, Singapore
| | - Edmund Chiong
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore; (J.N.R.); (S.M.T.); (Y.K.L.); (M.V.P.); (L.R.N.M.); (R.K.); (K.E.)
- Department of Urology, National University Hospital, National University Health System, Singapore 119074, Singapore
| | - Kesavan Esuvaranathan
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore; (J.N.R.); (S.M.T.); (Y.K.L.); (M.V.P.); (L.R.N.M.); (R.K.); (K.E.)
- Department of Urology, National University Hospital, National University Health System, Singapore 119074, Singapore
| | - Ratha Mahendran
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore; (J.N.R.); (S.M.T.); (Y.K.L.); (M.V.P.); (L.R.N.M.); (R.K.); (K.E.)
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Pal R, Talwar S, Pandey M, Nain VK, Sharma T, Tyagi S, Barik V, Chaudhary S, Gupta SK, Kumar Y, Nanda R, Singhal A, Pandey AK. Rv0495c regulates redox homeostasis in Mycobacterium tuberculosis. Tuberculosis (Edinb) 2024; 145:102477. [PMID: 38211498 DOI: 10.1016/j.tube.2024.102477] [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: 09/25/2023] [Revised: 12/18/2023] [Accepted: 01/05/2024] [Indexed: 01/13/2024]
Abstract
Mycobacterium tuberculosis (Mtb) has evolved sophisticated surveillance mechanisms to neutralize the ROS-induces toxicity which otherwise would degrade a variety of biological molecules including proteins, nucleic acids and lipids. In the present study, we find that Mtb lacking the Rv0495c gene (ΔRv0495c) is presented with a highly oxidized cytosolic environment. The superoxide-induced lipid peroxidation resulted in altered colony morphology and loss of membrane integrity in ΔRv0495c. As a consequence, ΔRv0495c demonstrated enhanced susceptibility when exposed to various host-induced stress conditions. Further, as expected, we observed a mutant-specific increase in the abundance of transcripts that encode proteins involved in antioxidant defence. Surprisingly, despite showing a growth defect phenotype in macrophages, the absence of the Rv0495c enhanced the pathogenicity and augmented the ability of the Mtb to grow inside the host. Additionally, our study revealed that Rv0495c-mediated immunomodulation by the pathogen helps create a favorable niche for long-term survival of Mtb inside the host. In summary, the current study underscores the fact that the truce in the war between the host and the pathogen favours long-term disease persistence in tuberculosis. We believe targeting Rv0495c could potentially be explored as a strategy to potentiate the current anti-TB regimen.
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Affiliation(s)
- Rahul Pal
- Mycobacterial Pathogenesis Laboratory, Centre for Tuberculosis Research, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Sakshi Talwar
- Mycobacterial Pathogenesis Laboratory, Centre for Tuberculosis Research, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Manitosh Pandey
- Mycobacterial Pathogenesis Laboratory, Centre for Tuberculosis Research, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Vaibhav Kumar Nain
- Mycobacterial Pathogenesis Laboratory, Centre for Tuberculosis Research, Translational Health Science and Technology Institute, Faridabad, Haryana, India; Jawaharlal Nehru University, New Delhi, India
| | - Taruna Sharma
- Mycobacterial Pathogenesis Laboratory, Centre for Tuberculosis Research, Translational Health Science and Technology Institute, Faridabad, Haryana, India; Jawaharlal Nehru University, New Delhi, India
| | - Shaifali Tyagi
- Mycobacterial Pathogenesis Laboratory, Centre for Tuberculosis Research, Translational Health Science and Technology Institute, Faridabad, Haryana, India; Jawaharlal Nehru University, New Delhi, India
| | - Vishawjeet Barik
- Mycobacterial Pathogenesis Laboratory, Centre for Tuberculosis Research, Translational Health Science and Technology Institute, Faridabad, Haryana, India; Jawaharlal Nehru University, New Delhi, India
| | - Shweta Chaudhary
- Translational Health Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Sonu Kumar Gupta
- Non-communicable Disease Centre, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Yashwant Kumar
- Non-communicable Disease Centre, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Ranjan Nanda
- Translational Health Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Amit Singhal
- Infectious Diseases Labs (ID Labs), Agency for Science Technology and Research (A*STAR), Singapore, 138648, Republic of Singapore; Singapore Immunology Network (SIgN), A*STAR, Singapore, 138648, Republic of Singapore
| | - Amit Kumar Pandey
- Mycobacterial Pathogenesis Laboratory, Centre for Tuberculosis Research, Translational Health Science and Technology Institute, Faridabad, Haryana, India.
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Sao Emani C, Reiling N. Spermine enhances the activity of anti-tuberculosis drugs. Microbiol Spectr 2024; 12:e0356823. [PMID: 38095461 PMCID: PMC10782994 DOI: 10.1128/spectrum.03568-23] [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: 10/04/2023] [Accepted: 11/11/2023] [Indexed: 12/21/2023] Open
Abstract
IMPORTANCE This is the first study that attempted to demonstrate the mechanisms of reactive oxygen species (ROS) generation by spermine (Spm) in Mycobacterium tuberculosis (M.tb). Furthermore, this is the first study to demonstrate that it is able to enhance the activity of currently available and World Health Organization (WHO)-approved tuberculosis (TB) drugs. Spermine can easily be obtained since it is already found in our diet. Moreover, as opposed to conventional antibiotics, it is less toxic to humans since it is found in millimolar concentrations in the body. Finally, with the difficulty of curing TB with conventional antibiotics, this study suggests that less toxic molecules, such as Spm, could in a long-term perspective be incorporated in a TB regimen to boost the treatment.
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Affiliation(s)
- Carine Sao Emani
- Microbial Interface Biology, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Norbert Reiling
- Microbial Interface Biology, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Borstel, Germany
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Lee JM, Kim LH, Kim SY, Jhun BW, Lee W, Shin SJ. Intracellular and in vivo activities of oxazolidinone drugs against Mycobacterium avium complex infection. Sci Rep 2023; 13:20631. [PMID: 37996500 PMCID: PMC10667338 DOI: 10.1038/s41598-023-48001-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: 07/11/2023] [Accepted: 11/21/2023] [Indexed: 11/25/2023] Open
Abstract
The prevalence of Mycobacterium avium complex-pulmonary disease (MAC-PD) has become a growing concern worldwide, and current treatments involving macrolides (clarithromycin [CLR] or azithromycin), ethambutol, and rifampicin have limited success, highlighting the need for better therapeutic strategies. Recently, oxazolidinone drugs have been identified as novel anti-tuberculosis drugs effective against drug-resistant M. tuberculosis. However, the effects of these drugs against MAC are still controversial due to limited data. Here, we first evaluated the intracellular anti-MAC activities of two oxazolidinone drugs, linezolid (LZD) and delpazolid (DZD), against 10 macrolide-susceptible MAC strains and one macrolide-resistant M. avium strain in murine bone marrow-derived macrophages (BMDMs) and found that both drugs demonstrated similar potential. The synergistic efficacies with CLR were then determined in a chronic progressive MAC-PD murine model by initiating a 4-week treatment at 8 weeks post-infection. Upon assessment of bacterial burdens and inflamed lesions, oxazolidinone drugs exhibited no anti-MAC effect, and there was no significant difference in the synergistic effect of CLR between LZD and DZD. These findings suggest that oxazolidinone drugs inhibit intracellular bacterial growth, even against macrolide-resistant MAC, but their clinical application requires further consideration.
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Affiliation(s)
- Ju Mi Lee
- Department of Microbiology, Institute for Immunology and Immunological Disease, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, South Korea
| | - Lee-Han Kim
- Department of Microbiology, Institute for Immunology and Immunological Disease, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, South Korea
| | - Su-Young Kim
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Byung Woo Jhun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Wonsik Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
| | - Sung Jae Shin
- Department of Microbiology, Institute for Immunology and Immunological Disease, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, South Korea.
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Cebrián-Sastre E, Chiner-Oms A, Torres-Pérez R, Comas I, Oliveros JC, Blázquez J, Castañeda-García A. Selective Pressure by Rifampicin Modulates Mutation Rates and Evolutionary Trajectories of Mycobacterial Genomes. Microbiol Spectr 2023; 11:e0101723. [PMID: 37436169 PMCID: PMC10433840 DOI: 10.1128/spectrum.01017-23] [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: 03/09/2023] [Accepted: 06/16/2023] [Indexed: 07/13/2023] Open
Abstract
Resistance to the frontline antibiotic rifampicin constitutes a challenge to the treatment and control of tuberculosis. Here, we analyzed the mutational landscape of Mycobacterium smegmatis during long-term evolution with increasing concentrations of rifampicin, using a mutation accumulation assay combined with whole-genome sequencing. Antibiotic treatment enhanced the acquisition of mutations, doubling the genome-wide mutation rate of the wild-type cells. While antibiotic exposure led to extinction of almost all wild-type lines, the hypermutable phenotype of the ΔnucS mutant strain (noncanonical mismatch repair deficient) provided an efficient response to the antibiotic, leading to high rates of survival. This adaptative advantage resulted in the emergence of higher levels of rifampicin resistance, an accelerated acquisition of drug resistance mutations in rpoB (β RNA polymerase), and a wider diversity of evolutionary pathways that led to drug resistance. Finally, this approach revealed a subset of adaptive genes under positive selection with rifampicin that could be associated with the development of antibiotic resistance. IMPORTANCE Rifampicin is the most important first-line antibiotic against mycobacterial infections, including tuberculosis, one of the top causes of death worldwide. Acquisition of rifampicin resistance constitutes a major global public health problem that makes the control of the disease challenging. Here, we performed an experimental evolution assay under antibiotic selection to analyze the response and adaptation of mycobacteria, leading to the acquisition of rifampicin resistance. This approach explored the total number of mutations that arose in the mycobacterial genomes under long-term rifampicin exposure, using whole-genome sequencing. Our results revealed the effect of rifampicin at a genomic level, identifying different mechanisms and multiple pathways leading to rifampicin resistance in mycobacteria. Moreover, this study detected that an increase in the rate of mutations led to enhanced levels of drug resistance and survival. In summary, all of these results could be useful to understand and prevent the emergence of drug-resistant isolates in mycobacterial infections.
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Affiliation(s)
- E. Cebrián-Sastre
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB), CSIC, Madrid, Spain
| | - A. Chiner-Oms
- Instituto de Biomedicina de Valencia (IBV), CSIC, Valencia, Spain
| | - R. Torres-Pérez
- Servicio de Bioinformática para Genómica y Proteómica. Centro Nacional de Biotecnología (CNB), CSIC, Madrid, Spain
| | - I. Comas
- Instituto de Biomedicina de Valencia (IBV), CSIC, Valencia, Spain
| | - J. C. Oliveros
- Servicio de Bioinformática para Genómica y Proteómica. Centro Nacional de Biotecnología (CNB), CSIC, Madrid, Spain
| | - J. Blázquez
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB), CSIC, Madrid, Spain
| | - A. Castañeda-García
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología (CNB), CSIC, Madrid, Spain
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (CNM-ISCIII), Majadahonda (Madrid), Spain
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Sao Emani C, Richter A, Singh A, Bhatt A, Av-Gay Y. The ΔCysK 2 mutant of Mycobacterium tuberculosis is sensitive to vancomycin associated with changes in cell wall phospholipid profile. Biochem Biophys Res Commun 2022; 624:120-126. [PMID: 35940124 DOI: 10.1016/j.bbrc.2022.07.096] [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: 07/05/2022] [Revised: 07/11/2022] [Accepted: 07/25/2022] [Indexed: 11/26/2022]
Abstract
Cysteine plays a versatile role in cellular physiology and has previously been shown to be instrumental to Mycobacterium tuberculosis (M.tb) pathophysiology. In this study, we have generated mutants deficient in CysK2 and CysH, the key Cysteine, biosynthetic enzymes. In contrast to the ΔcysH mutant, the ΔcysK2 mutant is not an auxotroph and as such not essential for cysteine biosynthesis. Interestingly, the ΔcysK2 mutant shows increased sensitivity to cumene hydroperoxide, vitamin C, diamide, rifampicin and Vancomycin and shows alterations in phospholipid profile of Mtb cell wall. Our findings suggest that alteration in phospholipids content of M.tb cell wall by CysK2 may form a mode of defence against selected antibiotics and oxidative stress.
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Affiliation(s)
- Carine Sao Emani
- Division of Infectious Diseases, Department of Medicine/Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada.
| | - Adrian Richter
- Martin-Luther-University of Halle-Wittenberg, Kurt-Mothes-Straße 3, 06120, Halle, Germany
| | - Albel Singh
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Birmingham, B15 2TT, UK
| | - Apoorva Bhatt
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Birmingham, B15 2TT, UK
| | - Yossef Av-Gay
- Division of Infectious Diseases, Department of Medicine/Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada.
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A Major Facilitator Superfamily (MFS) Efflux Pump, SCO4121, from Streptomyces coelicolor with Roles in Multidrug Resistance and Oxidative Stress Tolerance and Its Regulation by a MarR Regulator. Appl Environ Microbiol 2021; 87:AEM.02238-20. [PMID: 33483304 DOI: 10.1128/aem.02238-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 01/12/2021] [Indexed: 12/12/2022] Open
Abstract
Overexpression of efflux pumps is one of the major determinants of resistance in bacteria. Streptomyces species harbor a large array of efflux pumps that are transcriptionally silenced under laboratory conditions. However, their dissemination results in multidrug resistance in different clinical pathogens. In this study, we have identified an efflux pump from Streptomyces coelicolor, SCO4121, belonging to the major facilitator superfamily (MFS) family of transporters and characterized its role in antibiotic resistance. SCO4121 provided resistance to multiple dissimilar drugs upon overexpression in both native and heterologous hosts. Further, deletion of SCO4121 resulted in increased sensitivity toward ciprofloxacin and chloramphenicol, suggesting the pump to be a major transporter of these substrates. Apart from providing multidrug resistance, SCO4121 imparted increased tolerance against the strong oxidant HOCl. In wild-type Streptomyces coelicolor cells, these drugs were found to transcriptionally regulate the pump in a concentration-dependent manner. Additionally, we identified SCO4122, a MarR regulator that positively regulates SCO4121 in response to various drugs and the oxidant HOCl. Thus, through these studies we present the multiple roles of SCO4121 in S. coelicolor and highlight the intricate mechanisms via which it is regulated in response to antibiotics and oxidative stress.IMPORTANCE One of the key mechanisms of drug resistance in bacteria is overexpression of efflux pumps. Streptomyces species are a reservoir of a large number of efflux pumps, potentially to provide resistance to both endogenous and nonendogenous antibiotics. While many of these pumps are not expressed under standard laboratory conditions, they result in resistance to multiple drugs when spread to other bacterial pathogens through horizontal gene transfer. In this study, we have identified a widely conserved efflux pump SCO4121 from Streptomyces coelicolor with roles in both multidrug resistance and oxidative stress tolerance. We also report the presence of an adjacent MarR regulator, SCO4122, which positively regulates SCO4121 in the presence of diverse substrates in a redox-responsive manner. This study highlights that soil bacteria such as Streptomyces can reveal novel mechanisms of antibiotic resistance that may potentially emerge in clinically important bacteria.
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Ethanol in Combination with Oxidative Stress Significantly Impacts Mycobacterial Physiology. J Bacteriol 2020; 202:JB.00222-20. [PMID: 32928928 DOI: 10.1128/jb.00222-20] [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: 04/24/2020] [Accepted: 09/02/2020] [Indexed: 11/20/2022] Open
Abstract
Here, we investigate the mycobacterial response to the combined stress of an organic oxidant (cumene hydroperoxide [CHP]) and a solvent (ethanol). To understand the interaction between the two stressors, we treated Mycobacterium smegmatis cells to a range of ethanol concentrations (2.5% to 10% [vol/vol]) in combination with a subinhibitory concentration of 1 mM CHP. It was observed that the presence of CHP increases the efficacy of ethanol in inducing rapid cell death. The data further suggest that ethanol reacts with the alkoxy radicals to produce ethanol-derived peroxides. These radicals induce significant membrane damage and lead to cell lysis. The ethanol-derived radicals were primarily recognized by the cells as organic radicals, as was evident by the differential upregulation of the ohr-ohrR genes that function in cells treated with the combination of ethanol and CHP. The role of organic peroxide reductase, Ohr, was further confirmed by the significantly higher sensitivity of the deletion mutant to CHP and the combined stress treatment of CHP and ethanol. Moreover, we also observed the sigma factor σB to be important for the cells treated with ethanol alone as well as the aforementioned combination. A ΔsigB mutant strain had significantly higher susceptibility to the stress conditions. This finding was correlated with the σB-dependent transcriptional regulation of ohr and ohrR In summary, our data indicate that the combination of low levels of ethanol and organic peroxides induce ethanol-derived organic radicals that lead to significant oxidative stress on the cells in a concentration-dependent manner.IMPORTANCE Bacterial response to a combination of stresses can be unexpected and very different compared with that of an individual stress treatment. This study explores the physiological and transcriptional response of mycobacteria in response to the combinatorial treatment of an oxidant with the commonly used solvent ethanol. The presence of a subinhibitory concentration of organic peroxide increases the effectiveness of ethanol by inducing reactive peroxides that destroy the membrane integrity of cells in a significantly short time span. Our work elucidates a mechanism of targeting the complex mycobacterial membrane, which is its primary source of intrinsic resistance. Furthermore, it also demonstrates the importance of exploring the effect of various stress conditions on inducing bacterial clearance.
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Inhibitory activity of traditional plants against Mycobacterium smegmatis and their action on Filamenting temperature sensitive mutant Z (FtsZ)-A cell division protein. PLoS One 2020; 15:e0232482. [PMID: 32357366 PMCID: PMC7195194 DOI: 10.1371/journal.pone.0232482] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 04/15/2020] [Indexed: 11/19/2022] Open
Abstract
The study was designed to assess whether plant extracts / phytochemical (D-Pinitol) synergistically combine with antituberculosis drugs and act on Mycobacterium smegmatis (M. smegmatis) as well as assess their mode of action on Mycobacterium tuberculosis (M.tb) Filamenting temperature sensitive mutant Z (FtsZ) protein. Resazurin microtitre plate assay (Checker board) was performed to analyze the activity of plant extracts against M. smegmatis. Synergistic behaviour of plant extracts / D-Pinitol with Isoniazid (INH) and Rifampicin (RIF) were determined by time–kill and checker board assays. Elongation of M. smegmatis cells due to this treatment was determined by light microscopy. The effect of Hexane methanol extract (HXM) plant extracts on cell viability was determined using PI/SYTO9 dual dye reporter Live/Dead assay. Action of HXM plant extracts / D-Pinitol on inhibition of FtsZ protein was done using Guanosine triphosphatase (GTPase) light scattering assay and quantitative Polymerase Chain Reaction (qPCR). The Hexane-methanolic plant extract of Acacia nilotica, Aegle marmelos and Glycyrrhiza glabra showed antimycobacterial activity at 1.56 ± 0.03, 1.32 ± 0.02 and 1.25 ± 0.03 mg/mL respectively and that of INH and RIF were 4.00 ± 0.06 μg/mL and 2.00 ± 0.04 μg/mL respectively. These plant extracts and major phytochemical exudate D-Pinitol was found to act synergistically with antimycobacterial drugs INH and RIF with an FIC index ~ 0.20. Time-Kill kinetics studies indicate that, these plant extracts were bacteriostatic in nature. D-Pinitol in conjunction with INH and RIF exhibited a 2 Log reduction in the growth of viable cells compared to untreated. Attempt to elucidate their mode of action through phenotypic analysis indicated that these plant extracts and D-Pinitol was found to interfere in cell division there by leading to an abnormal elongated cellular morphology. HXM extracts and D-Pinitol synergistically combined with the first line tuberculosis drugs, INH and RIF, to act on M. smegmatis. The increase in the length of M. smegmatis cells on treatment with D-Pinitol and HXM extract of the plants indicated that they hinder the cell division mechanism thereby leading to a filamentous phenotype, and finally leading to cell death. In addition, the integrity of the bacterial cell membrane is also altered causing cell death. Further gene expression analysis showed that these plant extracts and D-Pinitol hampers with function of FtsZ protein which was confirmed through in vitro inhibition of FtsZ–GTPase enzymatic activity.
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Patel YS, Mistry N, Mehra S. Repurposing artemisinin as an anti-mycobacterial agent in synergy with rifampicin. Tuberculosis (Edinb) 2019; 115:146-153. [DOI: 10.1016/j.tube.2019.03.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 03/04/2019] [Accepted: 03/12/2019] [Indexed: 01/25/2023]
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Ngwane AH, Petersen RD, Baker B, Wiid I, Wong HN, Haynes RK. The evaluation of the anti-cancer drug elesclomol that forms a redox-active copper chelate as a potential anti-tubercular drug. IUBMB Life 2019; 71:532-538. [PMID: 30698324 DOI: 10.1002/iub.2002] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 11/29/2018] [Accepted: 12/10/2018] [Indexed: 01/11/2023]
Abstract
The observations that the innate immune system employs copper to eliminate bacterial infection and that resistance to copper enhances virulence of Mycobacterium tuberculosis (Mtb) prompted us to examine the effects the anti-cancer agent elesclomol on Mtb. As a bis-thionohydrazide, elesclomol chelates with copper to form a copper complex in situ that via redox cycling of the metal ion greatly enhances oxidative stress in tumour cells. Here, we demonstrate that elesclomol is relatively potent against Mtb H37Rv with minimum inhibitory concentration of 10 μM (4 mg/L) and against multidrug resistant clinical isolates of Mtb, displays additive interactions with known tuberculosis drugs such as isoniazid and ethambutol, and a synergistic interaction with rifampicin. Controlled supplementation of elesclomol with copper in culture medium increased Mtb sensitivity by >65 fold. Overall, the activities of elesclomol in principle indicate the possibility of repurposing elesclomol or designing new thionohydrazides as potential drugs for use against Mtb. © 2019 IUBMB Life, 71(5):532-538, 2019.
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Affiliation(s)
- Andile H Ngwane
- DST-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Ray-Dean Petersen
- DST-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Bienyameen Baker
- DST-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Ian Wiid
- DST-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Ho Ning Wong
- Centre of Excellence for Pharmaceutical Sciences, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
| | - Richard K Haynes
- Centre of Excellence for Pharmaceutical Sciences, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
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Libardo MDJ, de la Fuente-Nuñez C, Anand K, Krishnamoorthy G, Kaiser P, Pringle SC, Dietz C, Pierce S, Smith MB, Barczak A, Kaufmann SHE, Singh A, Angeles-Boza AM. Phagosomal Copper-Promoted Oxidative Attack on Intracellular Mycobacterium tuberculosis. ACS Infect Dis 2018; 4:1623-1634. [PMID: 30141623 DOI: 10.1021/acsinfecdis.8b00171] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Copper (Cu) ions are critical in controlling bacterial infections, and successful pathogens like Mycobacterium tuberculosis (Mtb) possess multiple Cu resistance mechanisms. We report, as proof of concept, that a novel Cu hypersensitivity phenotype can be generated in mycobacteria, including Mtb, through a peptide, DAB-10, that is able to form reactive oxygen species (ROS) following Cu-binding. DAB-10 induces intramycobacterial oxidative stress in a Cu-dependent manner in vitro and during infection. DAB-10 penetrates murine macrophages and encounters intracellular mycobacteria. Significant intracellular Cu-dependent protection was observed when Mtb-infected macrophages were treated with DAB-10 alongside a cell-permeable Cu chelator. Treatment with the Cu chelator reversed the intramycobacterial oxidative shift induced by DAB-10. We conclude that DAB-10 utilizes the pool of phagosomal Cu ions in the host-Mtb interface to augment the mycobactericidal activity of macrophages while simultaneously exploiting the susceptibility of Mtb to ROS. DAB-10 serves as a model with which to develop next-generation, multifunctional antimicrobials.
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Affiliation(s)
- M. Daben J. Libardo
- Department of Chemistry, University of Connecticut, 55 N. Eagleville Road, Storrs, Connecticut 06269, United States
| | - Cesar de la Fuente-Nuñez
- Synthetic Biology Group, MIT Synthetic Biology Center, Department of Biological Engineering, and Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 21 Ames Street, Cambridge, Massachusetts 02139, United States
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 50 Vassar Street, Cambridge, Massachusetts 02139, United States
- The Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, Massachusetts 02139, United States
| | - Kushi Anand
- Department of Microbiology and Cell Biology, Center for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Gopinath Krishnamoorthy
- Department of Immunology, Max Planck Institute for Infection Biology, Virchowweg 12, Berlin 10117, Germany
| | - Peggy Kaiser
- Department of Immunology, Max Planck Institute for Infection Biology, Virchowweg 12, Berlin 10117, Germany
| | - Stephanie C. Pringle
- The Ragon Institute of Harvard, MIT, and Massachusetts General Hospital, 400 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Christopher Dietz
- Department of Chemistry, University of Connecticut, 55 N. Eagleville Road, Storrs, Connecticut 06269, United States
| | - Scott Pierce
- Department of Chemistry, University of Connecticut, 55 N. Eagleville Road, Storrs, Connecticut 06269, United States
| | - Michael B. Smith
- Department of Chemistry, University of Connecticut, 55 N. Eagleville Road, Storrs, Connecticut 06269, United States
| | - Amy Barczak
- The Ragon Institute of Harvard, MIT, and Massachusetts General Hospital, 400 Technology Square, Cambridge, Massachusetts 02139, United States
- Division of Infectious Disease, Massachusetts General Hospital, 55 Fruit Street, Boston, Massachusetts 02114, United States
- Department of Medicine, Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, United States
| | - Stefan H. E. Kaufmann
- Department of Immunology, Max Planck Institute for Infection Biology, Virchowweg 12, Berlin 10117, Germany
| | - Amit Singh
- Department of Microbiology and Cell Biology, Center for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Alfredo M. Angeles-Boza
- Department of Chemistry, University of Connecticut, 55 N. Eagleville Road, Storrs, Connecticut 06269, United States
- Institute of Materials Science, University of Connecticut, 97 N. Eagleville Road, Storrs, Connecticut 06269, United States
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