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Santoshi M, Bansia H, Hussain M, Jha AK, Nagaraja V. Identification of a 1-acyl-glycerol-3-phosphate acyltransferase from Mycobacterium tuberculosis, a key enzyme involved in triacylglycerol biosynthesis. Mol Microbiol 2024; 121:1164-1181. [PMID: 38676355 DOI: 10.1111/mmi.15265] [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: 12/30/2023] [Revised: 04/02/2024] [Accepted: 04/04/2024] [Indexed: 04/28/2024]
Abstract
Latent tuberculosis, caused by dormant Mycobacterium tuberculosis (Mtb), poses a threat to global health through the incubation of undiagnosed infections within the community. Dormant Mtb, which is phenotypically tolerant to antibiotics, accumulates triacylglycerol (TAG) utilizing fatty acids obtained from macrophage lipid droplets. TAG is vital to mycobacteria, serving as a cell envelope component and energy reservoir during latency. TAG synthesis occurs by sequential acylation of glycerol-3-phosphate, wherein the second acylation step is catalyzed by acylglycerol-3-phosphate acyltransferase (AGPAT), resulting in the production of phosphatidic acid (PA), a precursor for the synthesis of TAG and various phospholipids. Here, we have characterized a putative acyltransferase of Mtb encoded by Rv3816c. We found that Rv3816c has all four characteristic motifs of AGPAT, exists as a membrane-bound enzyme, and functions as 1-acylglycerol-3-phosphate acyltransferase. The enzyme could transfer the acyl group to acylglycerol-3-phosphate (LPA) from monounsaturated fatty acyl-coenzyme A of chain length 16 or 18 to produce PA. Complementation of Escherichia coli PlsC mutant in vivo by Rv3816c confirmed that it functions as AGPAT. Its active site mutants, H43A and D48A, were incapable of transferring the acyl group to LPA in vitro and were not able to rescue the growth defect of E. coli PlsC mutant in vivo. Identifying Rv3816c as AGPAT and comparing its properties with other AGPAT homologs is not only a step toward understanding the TAG biosynthesis in mycobacteria but has the potential to explore it as a drug target.
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Affiliation(s)
- Meghna Santoshi
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
| | - Harsh Bansia
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
| | - Muzammil Hussain
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
| | - Abodh Kumar Jha
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
| | - Valakunja Nagaraja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
- Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
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Lyu L, Jia H, Liu Q, Ma W, Li Z, Pan L, Zhang X. Individualized lipid profile in urine-derived extracellular vesicles from clinical patients with Mycobacterium tuberculosis infections. Front Microbiol 2024; 15:1409552. [PMID: 38873163 PMCID: PMC11169924 DOI: 10.3389/fmicb.2024.1409552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 05/06/2024] [Indexed: 06/15/2024] Open
Abstract
Background Lipids are a key nutrient source for the growth and reproduction of Mycobacterium tuberculosis (Mtb). Urine-derived extracellular vesicles (EVs), because of its non-invasive sampling, lipid enrichment, and specific sorting character, have been recognized as a promising research target for biomarker discovery and pathogenesis elucidation in tuberculosis (TB). We aim to profile lipidome of Mtb-infected individuals, offer novel lipid signatures for the development of urine-based TB testing, and provide new insights into the lipid metabolism after Mtb infection. Methods Urine-derived extracellular vesicles from 41 participants (including healthy, pulmonary tuberculosis, latent tuberculosis patients, and other lung disease groups) were isolated and individually detected using targeted lipidomics and proteomics technology platforms. Biomarkers were screened by multivariate and univariate statistical analysis and evaluated by SPSS software. Correlation analyses were performed on lipids and proteins using the R Hmisc package. Results Overall, we identified 226 lipids belonging to 14 classes. Of these, 7 potential lipid biomarkers for TB and 6 for latent TB infection (LTBI) were identified, all of which were classified into diacylglycerol (DAG), monoacylglycerol (MAG), free fatty acid (FFA), and cholesteryl ester (CE). Among them, FFA (20:1) was the most promising biomarker target in diagnosing TB/LTBI from other compared groups and also have great diagnostic performance in distinguishing TB from LTBI with AUC of 0.952. In addition, enhanced lipolysis happened as early as individuals got latent Mtb infection, and ratio of raft lipids was gradually elevated along TB progression. Conclusion This study demonstrated individualized lipid profile of urinary EVs in patients with Mtb infection, revealed novel potential lipid biomarkers for TB/LTBI diagnosis, and explored mechanisms by which EV lipid raft-dependent bio-processes might affect pathogenesis. It lays a solid foundation for the subsequent diagnosis and therapeutic intervention of TB.
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Affiliation(s)
- Lingna Lyu
- Department of Gastroenterology and Hepatology, Beijing You’an Hospital Affiliated to Capital Medical University, Beijing, China
- Beijing Key Laboratory for Drug Resistant Tuberculosis Research, Beijing Chest Hospital Affiliated to Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, China
| | - Hongyan Jia
- Beijing Key Laboratory for Drug Resistant Tuberculosis Research, Beijing Chest Hospital Affiliated to Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, China
| | - Qiuyue Liu
- Beijing Key Laboratory for Drug Resistant Tuberculosis Research, Beijing Chest Hospital Affiliated to Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, China
| | - Wenxia Ma
- Department of Gastroenterology and Hepatology, Beijing You’an Hospital Affiliated to Capital Medical University, Beijing, China
| | - Zihui Li
- Beijing Key Laboratory for Drug Resistant Tuberculosis Research, Beijing Chest Hospital Affiliated to Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, China
| | - Liping Pan
- Beijing Key Laboratory for Drug Resistant Tuberculosis Research, Beijing Chest Hospital Affiliated to Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, China
| | - Xiuli Zhang
- The Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China, Beijing, China
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Lu Y, Chen H, Shao Z, Sun L, Li C, Lu Y, You X, Yang X. Deletion of the Mycobacterium tuberculosis cyp138 gene leads to changes in membrane-related lipid composition and antibiotic susceptibility. Front Microbiol 2024; 15:1301204. [PMID: 38591032 PMCID: PMC10999552 DOI: 10.3389/fmicb.2024.1301204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 03/01/2024] [Indexed: 04/10/2024] Open
Abstract
Introduction Mycobacterium tuberculosis (Mtb), the main cause of tuberculosis (TB), has brought a great burden to the world's public health. With the widespread use of Mtb drug-resistant strains, the pressure on anti-TB treatment is increasing. Anti-TB drugs with novel structures and targets are urgently needed. Previous studies have revealed a series of CYPs with important roles in the survival and metabolism of Mtb. However, there is little research on the structure and function of CYP138. Methods In our study, to discover the function and targetability of CYP138, a cyp138-knockout strain was built, and the function of CYP138 was speculated by the comparison between cyp138-knockout and wild-type strains through growth curves, growth status under different carbon sources, infection curves, SEM, MIC tests, quantitative proteomics, and lipidomics. Results and discussion The knockout of cyp138 was proven to affect the Mtb's macrophage infection, antibiotics susceptibility, and the levels of fatty acid metabolism, membrane-related proteins, and lipids such as triacylglycerol. We proposed that CYP138 plays an important role in the synthesis and decomposition of lipids related to the cell membrane structure as a new potential anti-tuberculosis drug target.
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Affiliation(s)
- Yun Lu
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Division for Medicinal Microorganisms-related Strains, CAMS Collection Center of Pathogenic Microorganisms, Beijing, China
| | - Hongtong Chen
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Division for Medicinal Microorganisms-related Strains, CAMS Collection Center of Pathogenic Microorganisms, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Zhiyuan Shao
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Division for Medicinal Microorganisms-related Strains, CAMS Collection Center of Pathogenic Microorganisms, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Lang Sun
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Division for Medicinal Microorganisms-related Strains, CAMS Collection Center of Pathogenic Microorganisms, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Congran Li
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Division for Medicinal Microorganisms-related Strains, CAMS Collection Center of Pathogenic Microorganisms, Beijing, China
| | - Yu Lu
- Beijing Key Laboratory of Drug Resistance Tuberculosis Research, Beijing Tuberculosis and Thoracic Tumor Research Institute, and Beijing Chest Hospital, Capital Medical University, Beijing, China
| | - Xuefu You
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Division for Medicinal Microorganisms-related Strains, CAMS Collection Center of Pathogenic Microorganisms, Beijing, China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xinyi Yang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Division for Medicinal Microorganisms-related Strains, CAMS Collection Center of Pathogenic Microorganisms, Beijing, China
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Sturm A, Sun P, Avila-Pacheco J, Clatworthy AE, Bloom-Ackermann Z, Wuo MG, Gomez JE, Jin S, Clish CB, Kiessling LL, Hung DT. Genetic factors affecting storage and utilization of lipids during dormancy in Mycobacterium tuberculosis. mBio 2024; 15:e0320823. [PMID: 38236034 PMCID: PMC10865790 DOI: 10.1128/mbio.03208-23] [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: 12/05/2023] [Accepted: 12/11/2023] [Indexed: 01/19/2024] Open
Abstract
Mycobacterium tuberculosis (Mtb) can adopt a non-growing dormant state during infection that may be critical to both active and latent tuberculosis. During dormancy, Mtb is widely tolerant toward antibiotics, a significant obstacle in current anti-tubercular drug regimens, and retains the ability to persist in its environment. We aimed to identify novel mechanisms that permit Mtb to survive dormancy in an in vitro carbon starvation model using transposon insertion sequencing and gene expression analysis. We identified a previously uncharacterized component of the lipid transport machinery, omamC, which was upregulated and required for survival during carbon starvation. We show that OmamC plays a role both in increasing fatty acid stores during growth in rich media and enhancing fatty acid utilization during starvation. Besides its involvement in lipid metabolism, OmamC levels affected the expression of the anti-anti-sigma factor rv0516c and other genes to improve Mtb survival during carbon starvation and increase its tolerance toward rifampicin, a first-line drug effective against non-growing Mtb. Importantly, we show that Mtb can be eradicated during carbon starvation, in an OmamC-dependent manner, by inhibiting lipid metabolism with the lipase inhibitor tetrahydrolipstatin. This work casts new light into the survival processes of non-replicating, drug-tolerant Mtb by identifying new proteins involved in lipid metabolism required for the survival of dormant bacteria and exposing a potential vulnerability that could be exploited for antibiotic discovery.IMPORTANCETuberculosis is a global threat, with ~10 million yearly active cases. Many more people, however, live with "latent" infection, where Mycobacterium tuberculosis survives in a non-replicative form. When latent bacteria activate and regrow, they elicit immune responses and result in significant host damage. Replicating and non-growing bacilli can co-exist; however, non-growing bacteria are considerably less sensitive to antibiotics, thus complicating treatment by necessitating long treatment durations. Here, we sought to identify genes important for bacterial survival in this non-growing state using a carbon starvation model. We found that a previously uncharacterized gene, omamC, is involved in storing and utilizing fatty acids as bacteria transition between these two states. Importantly, inhibiting lipid metabolism using a lipase inhibitor eradicates non-growing bacteria. Thus, targeting lipid metabolism may be a viable strategy for treating the non-growing population in strategies to shorten treatment durations of tuberculosis.
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Affiliation(s)
- Alexander Sturm
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Penny Sun
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
| | | | - Anne E. Clatworthy
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Zohar Bloom-Ackermann
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Michael G. Wuo
- Department of Chemistry, MIT, Cambridge, Massachusetts, USA
| | - James E. Gomez
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Soomin Jin
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
| | - Clary B. Clish
- Metabolomics Platform, Broad Institute, Cambridge, Massachusetts, USA
| | | | - Deborah T. Hung
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
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5
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Wang Y, Liu Y, Wang Y, Zhang A, Xie W, Zhang H, Weng Q, Xu M. Investigation of seasonal changes in lipid synthesis and metabolism-related genes in the oviduct of Chinese brown frog (<em>Rana dybowskii</em>). Eur J Histochem 2023; 67:3890. [PMID: 38116875 PMCID: PMC10773197 DOI: 10.4081/ejh.2023.3890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 12/09/2023] [Indexed: 12/21/2023] Open
Abstract
A peculiar physiological characteristic of the Chinese brown frog (Rana dybowskii) is that its oviduct dilates during pre-brumation rather than during the breeding season. This research aimed to examine the expression of genes connected with lipid synthesis and metabolism in the oviduct of R. dybowskii during both the breeding season and pre-brumation. We observed significant changes in the weight and size of the oviduct between the breeding season and pre-brumation. Furthermore, compared to the breeding season, pre-brumation exhibited significantly lower triglyceride content and a marked increase in free fatty acid content. Immunohistochemical results revealed the spatial distribution of triglyceride synthase (Dgat1), triglyceride hydrolase (Lpl and Hsl), fatty acid synthase (Fasn), and fatty acid oxidases (Cpt1a, Acadl, and Hadh) in oviductal glandular cells and epithelial cells during both the breeding season and pre-brumation. While the mRNA levels of triglycerides and free fatty acid synthesis genes (dgat1 and fasn) did not show a significant difference between the breeding season and pre-brumation, the mRNA levels of genes involved in triglycerides and free fatty acid metabolism (lpl, cpt1a, acadl, acox and hadh) were considerably higher during pre-brumation. Furthermore, the R. dybowskii oviduct's transcriptomic and metabolomic data confirmed differential expression of genes and metabolites enriched in lipid metabolism signaling pathways during both the breeding season and pre-brumation. Overall, these results suggest that alterations in lipid synthesis and metabolism during pre-brumation may potentially influence the expanding size of the oviduct, contributing to the successful overwintering of R. dybowskii.
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Affiliation(s)
- Yankun Wang
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
| | - Yuning Liu
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
| | - Yawei Wang
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
| | - Ao Zhang
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
| | - Wenqian Xie
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
| | - Haolin Zhang
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
| | - Qiang Weng
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
| | - Meiyu Xu
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
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6
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Remm S, De Vecchis D, Schöppe J, Hutter CAJ, Gonda I, Hohl M, Newstead S, Schäfer LV, Seeger MA. Structural basis for triacylglyceride extraction from mycobacterial inner membrane by MFS transporter Rv1410. Nat Commun 2023; 14:6449. [PMID: 37833269 PMCID: PMC10576003 DOI: 10.1038/s41467-023-42073-0] [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: 12/14/2022] [Accepted: 09/28/2023] [Indexed: 10/15/2023] Open
Abstract
Mycobacterium tuberculosis is protected from antibiotic therapy by a multi-layered hydrophobic cell envelope. Major facilitator superfamily (MFS) transporter Rv1410 and the periplasmic lipoprotein LprG are involved in transport of triacylglycerides (TAGs) that seal the mycomembrane. Here, we report a 2.7 Å structure of a mycobacterial Rv1410 homologue, which adopts an outward-facing conformation and exhibits unusual transmembrane helix 11 and 12 extensions that protrude ~20 Å into the periplasm. A small, very hydrophobic cavity suitable for lipid transport is constricted by a functionally important ion-lock likely involved in proton coupling. Combining mutational analyses and MD simulations, we propose that TAGs are extracted from the core of the inner membrane into the central cavity via lateral clefts present in the inward-facing conformation. The functional role of the periplasmic helix extensions is to channel the extracted TAG into the lipid binding pocket of LprG.
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Affiliation(s)
- Sille Remm
- Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
| | - Dario De Vecchis
- Center for Theoretical Chemistry, Ruhr University Bochum, Bochum, Germany
| | - Jendrik Schöppe
- Institute of Biochemistry, University of Zurich, Zürich, Switzerland
- Global Research Technologies, Novo Nordisk A/S, Måløv, Denmark
| | - Cedric A J Hutter
- Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
- Linkster Therapeutics, Zürich, Switzerland
| | - Imre Gonda
- Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
| | - Michael Hohl
- Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland
- Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Simon Newstead
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, United Kingdom
| | - Lars V Schäfer
- Center for Theoretical Chemistry, Ruhr University Bochum, Bochum, Germany.
| | - Markus A Seeger
- Institute of Medical Microbiology, University of Zurich, Zürich, Switzerland.
- National Center for Mycobacteria, Zurich, Switzerland.
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González-Escalada A, Rebollo MJ, Barrios Payan J, Hernández-Pando R, García MJ. Detection of Mycobacterial DNA in Human Bone Marrow. Microorganisms 2023; 11:1788. [PMID: 37512960 PMCID: PMC10384717 DOI: 10.3390/microorganisms11071788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/04/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023] Open
Abstract
Bone marrow is a cell-rich tissue of the reticuloendothelial system essential in the homeostasis and accurate functioning of hematopoiesis and of the immune system; moreover, it is also rich in lipids because it contains marrow adipocytes. This work aimed to evaluate the detection of mycobacterial DNA in human bone marrow as a tool to understand the complex pathology caused by the main pathogen Mycobacterium tuberculosis (Mtb). Formalin-fixed paraffin-embedded human bone marrow samples were studied using both conventional PCR + hybridization and in situ PCR to figure out the cell distribution of the targeted DNA. Samples were retrospectively collected from HIV+ patients with microbiologically proved mycobacterial infection and from subjects without evidence of infection. Mycobacterium avium (Mav) as well as Mtb DNA was detected in both settings, including tissues with and without granulomas. We detected DNA from both mycobacterial species, using in situ PCR, inside bone marrow macrophages. Other cell types, including adipocytes, showed positive signals only for Mtb DNA. This result suggested, for the first time, that marrow adipocytes could constitute an ideal reservoir for the persistence of Mtb, allowing the bacilli to establish long-lasting latent infection within a suitable lipid environment. This fact might differentiate pathogenic behavior of non-specialized pathogens such as Mav from that of specialized pathogens such as Mtb.
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Affiliation(s)
- Alba González-Escalada
- Facultad de Ciencias de la Salud, Area of Medical Microbiology, Rey Juan Carlos University, 28922 Alcorcon, Spain
| | - María José Rebollo
- Department of Preventive Medicine and Public Health and Microbiology, School of Medicine, Autonoma University of Madrid, 28029 Madrid, Spain
| | - Jorge Barrios Payan
- Experimental Pathology Section, Department of Pathology, National Institute of Medical Sciences and Nutrition Salvador Zubirán, México City 14080, Mexico
| | - Rogelio Hernández-Pando
- Experimental Pathology Section, Department of Pathology, National Institute of Medical Sciences and Nutrition Salvador Zubirán, México City 14080, Mexico
| | - María Jesús García
- Department of Preventive Medicine and Public Health and Microbiology, School of Medicine, Autonoma University of Madrid, 28029 Madrid, Spain
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Mekonnen D, Nibret E, Munshea A, Derbie A, Zenebe Y, Tadese A, Birku T, Tesfa E, Sinishaw MA, Getachew H, Gashaw Y, Yismaw G, Kebede MM, Gelaw B. Comparative serum lipid and immunohematological values among adult pulmonary tuberculosis and tuberculosis lymphadenitis cases and their association with sputum bacilli load and time to culture positivity in Northwestern Ethiopia. Lipids Health Dis 2023; 22:56. [PMID: 37106418 PMCID: PMC10134535 DOI: 10.1186/s12944-023-01821-3] [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: 12/31/2022] [Accepted: 04/21/2023] [Indexed: 04/29/2023] Open
Abstract
BACKGROUND The serum lipid and immunohematological values of tuberculosis lymphadenitis (TBLN) patients is poorly documented relative to pulmonary tuberculosis (PTB) cases. Therefore, the aim of this study was to investigate the serum lipid and immunohematological values of patients with TBLN in comparison with PTB (PTB) patients. METHODS An institution-based comparative cross-sectional study was conducted in Northwest Ethiopia from March to December 2021. The study participants were bacteriologically confirmed PTB (n = 82) and TBLN (n = 94) cases with no known comorbidity and whose ages was greater than 18 years and with no current pregnancy. Independent sample t-test, one-way ANOVA, box plot, and correlation matrix were used to analyze the data. RESULTS The body mass index (BMI), CD4 + T cell count, and high-density lipoprotein-Cholesterol (HDL-C) values were significantly higher among TBLN cases compared with PTB cases. Additionally, the total white blood cell (WBC) count, hemoglobin (Hb), total Cholesterol (CHO) and creatinine (Cr) values were relatively higher among TBLN than PTB (P > 0.05). On the reverse, the platelet count and triacylglycerol (TAG) values were relatively higher among PTB than in TBLN cases. While the mean days of culture positivity were 11.6 days for TBLN, the mean days of culture positivity were 14.0 days for PTB. Anemia and serum lipid values showed no correlation with sputum bacilli load and time to culture positivity. CONCLUSION Tuberculous lymphadenitis patients were well-endowed with serum lipid, immunological and nutritional status compared with PTB cases. Hence, the high incidence rate of TBLN in Ethiopia could not be explained by low peripheral immunohematological values, malnutrition, Anemia, and dyslipidemia. Further study for identifying the predictors for TBLN in Ethiopia is highly desirable.
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Affiliation(s)
- Daniel Mekonnen
- Department of Medical Laboratory Sciences, School of Health Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia.
- Health Biotechnology Division, Institute of Biotechnology, Bahir Dar University, Bahir Dar, Ethiopia.
| | - Endalkachew Nibret
- Health Biotechnology Division, Institute of Biotechnology, Bahir Dar University, Bahir Dar, Ethiopia
- Department of Biology, Bahir Dar University, Bahir Dar, Ethiopia
| | - Abaineh Munshea
- Health Biotechnology Division, Institute of Biotechnology, Bahir Dar University, Bahir Dar, Ethiopia
- Department of Biology, Bahir Dar University, Bahir Dar, Ethiopia
| | - Awoke Derbie
- Department of Medical Laboratory Sciences, School of Health Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
- Health Biotechnology Division, Institute of Biotechnology, Bahir Dar University, Bahir Dar, Ethiopia
- The Centre for Innovative Drug Development and Therapeutic Trials for Africa (CDT-Africa), Addis Ababa University, Addis Ababa, Ethiopia
| | - Yohannes Zenebe
- Department of Medical Laboratory Sciences, School of Health Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
- Health Biotechnology Division, Institute of Biotechnology, Bahir Dar University, Bahir Dar, Ethiopia
| | - Aimro Tadese
- Amhara Public Health Institute, Bahir Dar, Ethiopia
| | - Tigist Birku
- Amhara Public Health Institute, Bahir Dar, Ethiopia
| | - Endalamaw Tesfa
- Health Biotechnology Division, Institute of Biotechnology, Bahir Dar University, Bahir Dar, Ethiopia
- Department of Medical Biochemistry, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
| | - Mulusew Alemneh Sinishaw
- Department of Medical Laboratory Sciences, School of Health Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
| | | | - Yosef Gashaw
- Amhara Public Health Institute, Bahir Dar, Ethiopia
| | | | - Mihiretu M Kebede
- German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Baye Gelaw
- Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
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9
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Chen TT, Lin Y, Zhang S, Liu S, Song L, Zhong W, Luo ZQ, Han A. Atypical Legionella GTPase effector hijacks host vesicular transport factor p115 to regulate host lipid droplet. SCIENCE ADVANCES 2022; 8:eadd7945. [PMID: 36525490 PMCID: PMC9757750 DOI: 10.1126/sciadv.add7945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
The intracellular bacterial pathogen Legionella pneumophila uses hundreds of effector proteins to manipulate multiple processes of the host cells to establish a replicative niche known as Legionella-containing vacuole (LCV). Biogenesis of the LCV has been known to depend on host small guanosine triphosphatases (GTPases), but whether bacterial effector GTPases are also involved remains unknown. Here, we show that an ankyrin repeat containing effector LegA15 localizes directly in host lipid droplets (LDs), leading to Golgi apparatus fragmentation of the host cells by hijacking the host vesicular transport factor p115. LegA15 is a GTPase with a unique catalytic mechanism, unlike any eukaryotic small GTPases. Moreover, the effector LegA15 co-opts p115 to modulate homeostasis of the host LDs in its GTPase-dependent manner. Together, our data reveal that an atypical GTPase effector regulates the host LDs through impeding the vesicle secretion system of the host cells for intracellular life cycle of Legionella.
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Affiliation(s)
- Tao-Tao Chen
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences and Faculty of Medicine, Xiamen University, Xiamen, Fujian 361102, China
- The Key Laboratory of Innate Immune Biology of Fujian Province, Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Biomedical Research Center of South China, Key Laboratory of OptoElectronic Science and Technology for Medicine of the Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Yanling Lin
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences and Faculty of Medicine, Xiamen University, Xiamen, Fujian 361102, China
| | - Shijun Zhang
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences and Faculty of Medicine, Xiamen University, Xiamen, Fujian 361102, China
| | - Shuxin Liu
- Department of Respiratory Medicine and Center of Pathogen Biology and Infectious Diseases, Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, State Key Laboratory of Zoonotic Diseases, The First Hospital, Jilin University, Changchun, China
| | - Lei Song
- Department of Respiratory Medicine and Center of Pathogen Biology and Infectious Diseases, Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, State Key Laboratory of Zoonotic Diseases, The First Hospital, Jilin University, Changchun, China
| | - Wenhong Zhong
- The Key Laboratory of Innate Immune Biology of Fujian Province, Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Biomedical Research Center of South China, Key Laboratory of OptoElectronic Science and Technology for Medicine of the Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Zhao-Qing Luo
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Aidong Han
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences and Faculty of Medicine, Xiamen University, Xiamen, Fujian 361102, China
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10
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Parbhoo T, Schurz H, Mouton JM, Sampson SL. Persistence of Mycobacterium tuberculosis in response to infection burden and host-induced stressors. Front Cell Infect Microbiol 2022; 12:981827. [PMID: 36530432 PMCID: PMC9755487 DOI: 10.3389/fcimb.2022.981827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 11/17/2022] [Indexed: 12/05/2022] Open
Abstract
Introduction As infection with Mycobacterium tuberculosis progresses, the bacilli experience various degrees of host stressors in the macrophage phagosome such as low pH, nutrient deprivation, or exposure to toxic agents, which promotes cell-to-cell phenotypic variation. This includes a physiologically viable but non- or slowly replicating persister subpopulation, which is characterised by a loss of growth on solid media, while remaining metabolically active. Persisters additionally evade the host immune response and macrophage antimicrobial processes by adapting their metabolic pathways to maintain survival and persistence in the host. Methods A flow cytometry-based dual-fluorescent replication reporter assay, termed fluorescence dilution, provided a culture-independent method to characterize the single-cell replication dynamics of M. tuberculosis persisters following macrophage infection. Fluorescence dilution in combination with reference counting beads and a metabolic esterase reactive probe, calcein violet AM, provided an effective approach to enumerate and characterize the phenotypic heterogeneity within M. tuberculosis following macrophage infection. Results Persister formation appeared dependent on the initial infection burden and intracellular bacterial burden. However, inhibition of phagocytosis by cytochalasin D treatment resulted in a significantly higher median percentage of persisters compared to inhibition of phagosome acidification by bafilomycin A1 treatment. Discussion Our results suggest that different host factors differentially impact the intracellular bacterial burden, adaptive mechanisms and entry into persistence in macrophages.
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11
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The High Plasticity of Nonpathogenic Mycobacterium brumae Induces Rapid Changes in Its Lipid Profile during Pellicle Maturation: The Potential of This Bacterium as a Versatile Cell Factory for Lipid Compounds of Therapeutic Interest. Int J Mol Sci 2022; 23:ijms232113609. [DOI: 10.3390/ijms232113609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/28/2022] [Accepted: 11/03/2022] [Indexed: 11/10/2022] Open
Abstract
The immunomodulatory potential of mycobacteria to be used for therapeutic purposes varies by species and culture conditions and is closely related to mycobacterial lipid composition. Although the lipids present in the mycobacterial cell wall are relevant, lipids are mainly stored in intracellular lipid inclusions (ILIs), which have emerged as a crucial structure in understanding mycobacteria-host interaction. Little is known about ILI ultrastructure, production, and composition in nonpathogenic species. In this study, we compared the lipid profiles of the nonpathogenic immunomodulatory agent Mycobacterium brumae during pellicle maturation under different culture conditions with qualitative and quantitative approaches by using high-resolution imaging and biochemical and composition analyses to understand ILI dynamics. The results showed wax esters, mainly in early stages of development, and acylglycerols in mature ILI composition, revealing changes in dynamics, amount, and morphometry, depending on pellicle maturation and the culture media used. Low-glycerol cultures induced ILIs with lower molecular weights which were smaller in size in comparison with the ILIs produced in glycerol-enriched media. The data also indicate the simple metabolic plasticity of lipid synthesis in M. brumae, as well as its high versatility in generating different lipid profiles. These findings provide an interesting way to enhance the production of key lipid structures via the simple modulation of cell culture conditions.
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12
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Parbhoo T, Mouton JM, Sampson SL. Phenotypic adaptation of Mycobacterium tuberculosis to host-associated stressors that induce persister formation. Front Cell Infect Microbiol 2022; 12:956607. [PMID: 36237425 PMCID: PMC9551238 DOI: 10.3389/fcimb.2022.956607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/24/2022] [Indexed: 11/29/2022] Open
Abstract
Mycobacterium tuberculosis exhibits a remarkable ability to interfere with the host antimicrobial response. The pathogen exploits elaborate strategies to cope with diverse host-induced stressors by modulating its metabolism and physiological state to prolong survival and promote persistence in host tissues. Elucidating the adaptive strategies that M. tuberculosis employs during infection to enhance persistence is crucial to understanding how varying physiological states may differentially drive disease progression for effective management of these populations. To improve our understanding of the phenotypic adaptation of M. tuberculosis, we review the adaptive strategies employed by M. tuberculosis to sense and coordinate a physiological response following exposure to various host-associated stressors. We further highlight the use of animal models that can be exploited to replicate and investigate different aspects of the human response to infection, to elucidate the impact of the host environment and bacterial adaptive strategies contributing to the recalcitrance of infection.
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13
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Chen G, Harwood JL, Lemieux MJ, Stone SJ, Weselake RJ. Acyl-CoA:diacylglycerol acyltransferase: Properties, physiological roles, metabolic engineering and intentional control. Prog Lipid Res 2022; 88:101181. [PMID: 35820474 DOI: 10.1016/j.plipres.2022.101181] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 12/15/2022]
Abstract
Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the last reaction in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG). DGAT activity resides mainly in membrane-bound DGAT1 and DGAT2 in eukaryotes and bifunctional wax ester synthase-diacylglycerol acyltransferase (WSD) in bacteria, which are all membrane-bound proteins but exhibit no sequence homology to each other. Recent studies also identified other DGAT enzymes such as the soluble DGAT3 and diacylglycerol acetyltransferase (EaDAcT), as well as enzymes with DGAT activities including defective in cuticular ridges (DCR) and steryl and phytyl ester synthases (PESs). This review comprehensively discusses research advances on DGATs in prokaryotes and eukaryotes with a focus on their biochemical properties, physiological roles, and biotechnological and therapeutic applications. The review begins with a discussion of DGAT assay methods, followed by a systematic discussion of TAG biosynthesis and the properties and physiological role of DGATs. Thereafter, the review discusses the three-dimensional structure and insights into mechanism of action of human DGAT1, and the modeled DGAT1 from Brassica napus. The review then examines metabolic engineering strategies involving manipulation of DGAT, followed by a discussion of its therapeutic applications. DGAT in relation to improvement of livestock traits is also discussed along with DGATs in various other eukaryotic organisms.
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Affiliation(s)
- Guanqun Chen
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Membrane Protein Disease Research Group, Edmonton T6G 2H7, Canada
| | - Scot J Stone
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
| | - Randall J Weselake
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada
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Li H, Yuan J, Duan S, Pang Y. Resistance and tolerance of Mycobacterium tuberculosis to antimicrobial agents-How M. tuberculosis can escape antibiotics. WIREs Mech Dis 2022; 14:e1573. [PMID: 35753313 DOI: 10.1002/wsbm.1573] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/22/2022] [Accepted: 05/30/2022] [Indexed: 12/13/2022]
Abstract
Tuberculosis (TB) poses a serious threat to public health worldwide since it was discovered. Until now, TB has been one of the top 10 causes of death from a single infectious disease globally. The treatment of active TB cases majorly relies on various anti-tuberculosis drugs. However, under the selection pressure by drugs, the continuous evolution of Mycobacterium tuberculosis (Mtb) facilitates the emergence of drug-resistant strains, further resulting in the accumulation of tubercle bacilli with multiple drug resistance, especially deadly multidrug-resistant TB and extensively drug-resistant TB. Researches on the mechanism of drug action and drug resistance of Mtb provide a new scheme for clinical management of TB patients, and prevention of drug resistance. In this review, we summarized the molecular mechanisms of drug resistance of existing anti-TB drugs to better understand the evolution of drug resistance of Mtb, which will provide more effective strategies against drug-resistant TB, and accelerate the achievement of the EndTB Strategy by 2035. This article is categorized under: Infectious Diseases > Molecular and Cellular Physiology.
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Affiliation(s)
- Haoran Li
- Department of Bacteriology and Immunology, Beijing Chest Hospital, Capital Medical University/Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, China
| | - Jinfeng Yuan
- Department of Bacteriology and Immunology, Beijing Chest Hospital, Capital Medical University/Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, China
| | - Shujuan Duan
- School of Medical Technology, Guangdong Medical University, Dongguan, China
| | - Yu Pang
- Department of Bacteriology and Immunology, Beijing Chest Hospital, Capital Medical University/Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, China
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15
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Sharma A, Vashistt J, Shrivastava R. Mycobacterium fortuitum fabG4 knockdown studies: Implication as pellicle and biofilm specific drug target. J Basic Microbiol 2022; 62:1504-1513. [PMID: 35736669 DOI: 10.1002/jobm.202200230] [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: 04/20/2022] [Revised: 05/25/2022] [Accepted: 06/11/2022] [Indexed: 11/08/2022]
Abstract
The fatty acid biosynthesis pathway is crucial for the formation of the mycobacterial cell envelope. The fatty acid synthase type-II (FAS-II) components are attractive targets for designing anti-biofilm inhibitors. Literature review, bioinformatics analysis, cloning, and sequencing led to the identification of a novel Mycobacterium fortuitum FAS-II gene MFfabG4 which interacts with mycobacterial proteins involved in biofilm formation. A manually curated M. fortuitum fatty acid biosynthesis pathway has been proposed exploiting functional studies from the Kyoto Encyclopedia of Genes and Genomes and Mycobrowser databases for MFFabG4. M. fortuitum MFfabG4 knockdown strain (FA) was constructed and validated by quantitative polymerase chain reaction. The FA strain displayed unstructured smooth colony architecture, correlating with decreased pathogenicity and virulence. MFfabG4 knockdown resulted in diminished pellicle and attenuated biofilm formation, along with impaired sliding motility, and reduced cell sedimentation. The FA strain showed lowered cell surface hydrophobicity, indicating attenuation in M. fortuitum intracellular infection-causing ability. Stress survival studies showed the requirement of MFfabG4 for survival in a nutrient-starved environment. The results indicate that MFfabG4 maintains the physiology of the cell envelope and is required for the formation of M. fortuitum pellicle and biofilm. The study corroborates the role of MFfabG4 as a pellicle- and biofilm-specific drug target and a potential diagnostic marker for M. fortuitum and related pathogenic mycobacteria.
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Affiliation(s)
- Ayushi Sharma
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, Himachal Pradesh, India
| | - Jitendraa Vashistt
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, Himachal Pradesh, India
| | - Rahul Shrivastava
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, Himachal Pradesh, India
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Guallar-Garrido S, Campo-Pérez V, Pérez-Trujillo M, Cabrera C, Senserrich J, Sánchez-Chardi A, Rabanal RM, Gómez-Mora E, Noguera-Ortega E, Luquin M, Julián E. Mycobacterial surface characters remodeled by growth conditions drive different tumor-infiltrating cells and systemic IFN-γ/IL-17 release in bladder cancer treatment. Oncoimmunology 2022; 11:2051845. [PMID: 35355681 PMCID: PMC8959508 DOI: 10.1080/2162402x.2022.2051845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Affiliation(s)
- Sandra Guallar-Garrido
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - Víctor Campo-Pérez
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
- Bacterial Infections and Antimicrobial Therapies group, Institute for Bioengineering of Catalonia (IBEC), Barcelona 08028, Spain
| | - Míriam Pérez-Trujillo
- Servei de Ressonància Magnètica Nuclear i Departament de Química, Facultat de Ciències i Biociències, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - Cecilia Cabrera
- AIDS Research Institute IrsiCaixa, Institut de Recerca en Ciències de la Salut Germans Trias i Universitat Autònoma de Barcelona, Badalona, 08916, Spain
| | - Jordi Senserrich
- AIDS Research Institute IrsiCaixa, Institut de Recerca en Ciències de la Salut Germans Trias i Universitat Autònoma de Barcelona, Badalona, 08916, Spain
| | - Alejandro Sánchez-Chardi
- Servei de Microscòpia, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
- Departament de Biologia Evolutiva, Ecologia i Universitat de Barcelona, Barcelona 08028, Spain
| | - Rosa Maria Rabanal
- Unitat de Patologia Murina i Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - Elisabet Gómez-Mora
- AIDS Research Institute IrsiCaixa, Institut de Recerca en Ciències de la Salut Germans Trias i Universitat Autònoma de Barcelona, Badalona, 08916, Spain
| | - Estela Noguera-Ortega
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - Marina Luquin
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - Esther Julián
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
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Transcriptomic Analysis of the Dual Response of Rhodococcus aetherivorans BCP1 to Inorganic Arsenic Oxyanions. Appl Environ Microbiol 2022; 88:e0220921. [PMID: 35311511 DOI: 10.1128/aem.02209-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial strains belonging to the genus Rhodococcus are able to degrade various toxic organic compounds and tolerate high concentrations of metal(loid)s. We have previously shown that Rhodococcus aetherivorans BCP1 is resistant to various levels of the two arsenic inorganic species, arsenite [As(III)] and arsenate [As(V)]. However, while arsenite showed toxic effects at concentrations as low as 5 mM, arsenate at 30 mM boosted the growth rate of BCP1 cells and was toxic only at concentrations of >100 mM. Since such behavior could be linked to peculiar aspects of its metabolism, the transcriptomic analysis of BCP1 cells exposed to 5 mM As(III) and 30 mM As(V) was performed in this work. The aim was to clarify the mechanisms underlying the arsenic stress response of the two growth phenotypes in the presence of the two different oxyanions. The results revealed that As(III) induced higher activity of reactive oxygen species (ROS)-scavenging enzymes than As(V) in relation to the expression of enzymes involved in cellular damage recovery and redox buffers/cofactors (ergothioneine, mycofactocin, and mycothiol). Further, As(III) downregulated pathways related to cell division, while both oxyanions downregulated genes involved in glycolysis. Notably, As(V) induced the expression of enzymes participating in the synthesis of metallophores and rearranged the central and energetic metabolism, also inducing alternative pathways for ATP synthesis and glucose consumption. This study, in providing transcriptomic data on R. aetherivorans exposed to arsenic oxyanions, sheds some light on the plasticity of the rhodococcal response to arsenic stress, which may be important for the improvement of biotechnological applications. IMPORTANCE Members of the genus Rhodococcus show high metabolic versatility and the ability to tolerate/resist numerous stress conditions, including toxic metals. R. aetherivorans BCP1 is able to tolerate high concentrations of the two inorganic arsenic oxyanions, arsenite [As(III)] and arsenate [As(V)]. Despite the fact that BCP1 intracellularly converts As(V) into As(III), this strain responds very differently to the presence of these two oxyanions in terms of cell growth and toxic effects. Indeed, while As(III) is highly toxic, exposure to specific concentrations of As(V) seems to boost cell growth. In this work, we investigated the transcriptomic response, ATP synthesis, glucose consumption, and H2O2 degradation in BCP1 cells exposed to As(III) and As(V), inducing two different growth phenotypes. Our results give an overview of the transcriptional rearrangements associated with the dual response of BCP1 to the two oxyanions and provide novel insights into the energetic metabolism of Rhodococcus under arsenic stress.
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18
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Bosch M, Pol A. Eukaryotic lipid droplets: metabolic hubs, and immune first responders. Trends Endocrinol Metab 2022; 33:218-229. [PMID: 35065875 DOI: 10.1016/j.tem.2021.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/23/2021] [Accepted: 12/23/2021] [Indexed: 12/18/2022]
Abstract
As major eukaryotic lipid storage organelles, lipid droplets (LDs) are metabolic hubs coordinating energy flux and building block distribution. Infectious pathogens often promote accumulation and physically interact with LDs. The most accepted view is that host LDs are hijacked by invaders to draw on nutrients for host colonisation. However, unique traits such as biogenesis plasticity, dynamic proteome, signalling capacity, and ability to interact with other organelles endow LDs with competencies to face complex biological challenges. Here, we focus on published data suggesting that LDs are not usurped organelles but innate immunity first responders. By comparison with analogous mechanisms activated on LDs in nutrient-poor environments, our review supports the hypothesis that host LDs actively participate in immunometabolism, immune signalling, and microbial killing.
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Affiliation(s)
- Marta Bosch
- Lipid Trafficking and Disease Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; Department of Biomedical Sciences, Faculty of Medicine, Universitat de Barcelona, 08036 Barcelona, Spain.
| | - Albert Pol
- Lipid Trafficking and Disease Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; Department of Biomedical Sciences, Faculty of Medicine, Universitat de Barcelona, 08036 Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010, Barcelona
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19
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Shivakoti R, Newman JW, Hanna LE, Queiroz ATL, Borkowski K, Gupte AN, Paradkar M, Satyamurthi P, Kulkarni V, Selva M, Pradhan N, Shivakumar SVBY, Natarajan S, Karunaianantham R, Gupte N, Thiruvengadam K, Fiehn O, Bharadwaj R, Kagal A, Gaikwad S, Sangle S, Golub JE, Andrade BB, Mave V, Gupta A, Padmapriyadarsini C. Host lipidome and tuberculosis treatment failure. Eur Respir J 2022; 59:2004532. [PMID: 34375300 PMCID: PMC9625841 DOI: 10.1183/13993003.04532-2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 05/24/2021] [Indexed: 01/09/2023]
Abstract
INTRODUCTION Host lipids play important roles in tuberculosis (TB) pathogenesis. Whether host lipids at TB treatment initiation (baseline) affect subsequent treatment outcomes has not been well characterised. We used unbiased lipidomics to study the prospective association of host lipids with TB treatment failure. METHODS A case-control study (n=192), nested within a prospective cohort study, was used to investigate the association of baseline plasma lipids with TB treatment failure among adults with pulmonary TB. Cases (n=46) were defined as TB treatment failure, while controls (n=146) were those without failure. Complex lipids and inflammatory lipid mediators were measured using liquid chromatography mass spectrometry techniques. Adjusted least-square regression was used to assess differences in groups. In addition, machine learning identified lipids with highest area under the curve (AUC) to classify cases and controls. RESULTS Baseline levels of 32 lipids differed between controls and those with treatment failure after false discovery rate adjustment. Treatment failure was associated with lower baseline levels of cholesteryl esters and oxylipin, and higher baseline levels of ceramides and triglycerides compared to controls. Two cholesteryl ester lipids combined in a unique classifier model provided an AUC of 0.79 (95% CI 0.65-0.93) in the test dataset for prediction of TB treatment failure. CONCLUSIONS We identified lipids, some with known roles in TB pathogenesis, associated with TB treatment failure. In addition, a lipid signature with prognostic accuracy for TB treatment failure was identified. These lipids could be potential targets for risk-stratification, adjunct therapy and treatment monitoring.
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Affiliation(s)
- Rupak Shivakoti
- Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Dept of Epidemiology, Columbia University Mailman School of Public Health, New York, NY, USA
| | - John W Newman
- Obesity and Metabolism Research Unit, Western Human Nutrition Research Center, Agricultural Research Service, United States Department of Agriculture, Davis, CA, USA
- Dept of Nutrition, University of California, Davis, CA, USA
- West Coast Metabolomics Center, University of California, Davis, CA, USA
| | | | - Artur T L Queiroz
- Instituto Goncalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
- Multinational Organization Network Sponsoring Translational and Epidemiological Research, Salvador, Brazil
| | - Kamil Borkowski
- West Coast Metabolomics Center, University of California, Davis, CA, USA
| | - Akshay N Gupte
- Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mandar Paradkar
- Byramjee-Jeejeebhoy Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | | | - Vandana Kulkarni
- Byramjee-Jeejeebhoy Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | - Murugesh Selva
- National Institute for Research in Tuberculosis, Chennai, India
| | - Neeta Pradhan
- Byramjee-Jeejeebhoy Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | | | | | | | - Nikhil Gupte
- Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Byramjee-Jeejeebhoy Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | | | - Oliver Fiehn
- West Coast Metabolomics Center, University of California, Davis, CA, USA
| | - Renu Bharadwaj
- Byramjee-Jeejeebhoy Government Medical College, Pune, India
| | - Anju Kagal
- Byramjee-Jeejeebhoy Government Medical College, Pune, India
| | - Sanjay Gaikwad
- Byramjee-Jeejeebhoy Government Medical College, Pune, India
| | | | - Jonathan E Golub
- Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Bruno B Andrade
- Instituto Goncalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
- Multinational Organization Network Sponsoring Translational and Epidemiological Research, Salvador, Brazil
- Faculdade de Medicina, Universidade Federal da Bahia, Salvador, Brazil
- Curso de Medicina, Faculdade de Tecnologia e Ciências, Salvador, Brazil
- Curso de Medicina, Universidade Salvador (UNIFACS), Laureate International Universities, Salvador, Brazil
- Escola Bahiana de Medicina e Saúde Pública (EBMSP), Salvador, Brazil
| | - Vidya Mave
- Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Byramjee-Jeejeebhoy Medical College-Johns Hopkins University Clinical Research Site, Pune, India
| | - Amita Gupta
- Dept of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Byramjee-Jeejeebhoy Medical College-Johns Hopkins University Clinical Research Site, Pune, India
- Equal contribution
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20
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Vilchèze C, Yan B, Casey R, Hingley-Wilson S, Ettwiller L, Jacobs WR. Commonalities of Mycobacterium tuberculosis Transcriptomes in Response to Defined Persisting Macrophage Stresses. Front Immunol 2022; 13:909904. [PMID: 35844560 PMCID: PMC9283954 DOI: 10.3389/fimmu.2022.909904] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 06/06/2022] [Indexed: 12/03/2022] Open
Abstract
As the goal of a bacterium is to become bacteria, evolution has imposed continued selections for gene expression. The intracellular pathogen Mycobacterium tuberculosis, the causative agent of tuberculosis, has adopted a fine-tuned response to survive its host's methods to aggressively eradicate invaders. The development of microarrays and later RNA sequencing has led to a better understanding of biological processes controlling the relationship between host and pathogens. In this study, RNA-seq was performed to detail the transcriptomes of M. tuberculosis grown in various conditions related to stresses endured by M. tuberculosis during host infection and to delineate a general stress response incurring during persisting macrophage stresses. M. tuberculosis was subjected to long-term growth, nutrient starvation, hypoxic and acidic environments. The commonalities between these stresses point to M. tuberculosis maneuvering to exploit propionate metabolism for lipid synthesis or to withstand propionate toxicity whilst in the intracellular environment. While nearly all stresses led to a general shutdown of most biological processes, up-regulation of pathways involved in the synthesis of amino acids, cofactors, and lipids were observed only in hypoxic M. tuberculosis. This data reveals genes and gene cohorts that are specifically or exclusively induced during all of these persisting stresses. Such knowledge could be used to design novel drug targets or to define possible M. tuberculosis vulnerabilities for vaccine development. Furthermore, the disruption of specific functions from this gene set will enhance our understanding of the evolutionary forces that have caused the tubercle bacillus to be a highly successful pathogen.
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Affiliation(s)
- Catherine Vilchèze
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Bo Yan
- Research Department, Genome Biology Division, New England Biolabs Inc., Ipswich, MA, United States
| | - Rosalyn Casey
- Department of Microbial Sciences, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Suzie Hingley-Wilson
- Department of Microbial Sciences, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Laurence Ettwiller
- Research Department, Genome Biology Division, New England Biolabs Inc., Ipswich, MA, United States
| | - William R. Jacobs
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, United States
- *Correspondence: William R. Jacobs Jr,
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Vaughn B, Abu Kwaik Y. Idiosyncratic Biogenesis of Intracellular Pathogens-Containing Vacuoles. Front Cell Infect Microbiol 2021; 11:722433. [PMID: 34858868 PMCID: PMC8632064 DOI: 10.3389/fcimb.2021.722433] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 10/25/2021] [Indexed: 12/12/2022] Open
Abstract
While most bacterial species taken up by macrophages are degraded through processing of the bacteria-containing vacuole through the endosomal-lysosomal degradation pathway, intravacuolar pathogens have evolved to evade degradation through the endosomal-lysosomal pathway. All intra-vacuolar pathogens possess specialized secretion systems (T3SS-T7SS) that inject effector proteins into the host cell cytosol to modulate myriad of host cell processes and remodel their vacuoles into proliferative niches. Although intravacuolar pathogens utilize similar secretion systems to interfere with their vacuole biogenesis, each pathogen has evolved a unique toolbox of protein effectors injected into the host cell to interact with, and modulate, distinct host cell targets. Thus, intravacuolar pathogens have evolved clear idiosyncrasies in their interference with their vacuole biogenesis to generate a unique intravacuolar niche suitable for their own proliferation. While there has been a quantum leap in our knowledge of modulation of phagosome biogenesis by intravacuolar pathogens, the detailed biochemical and cellular processes affected remain to be deciphered. Here we discuss how the intravacuolar bacterial pathogens Salmonella, Chlamydia, Mycobacteria, Legionella, Brucella, Coxiella, and Anaplasma utilize their unique set of effectors injected into the host cell to interfere with endocytic, exocytic, and ER-to-Golgi vesicle traffic. However, Coxiella is the main exception for a bacterial pathogen that proliferates within the hydrolytic lysosomal compartment, but its T4SS is essential for adaptation and proliferation within the lysosomal-like vacuole.
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Affiliation(s)
- Bethany Vaughn
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY, United States
| | - Yousef Abu Kwaik
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY, United States.,Center for Predictive Medicine, College of Medicine, University of Louisville, Louisville, KY, United States
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RNA-sequencing elucidates drug-specific mechanisms of antibiotic tolerance and resistance in M. abscessus. Antimicrob Agents Chemother 2021; 66:e0150921. [PMID: 34633851 PMCID: PMC8765290 DOI: 10.1128/aac.01509-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Mycobacterium abscessus is an opportunistic pathogen notorious for its resistance to most classes of antibiotics and low cure rates. M. abscessus carries an array of mostly unexplored defense mechanisms. A deeper understanding of antibiotic resistance and tolerance mechanisms is pivotal in development of targeted therapeutic regimens. We provide the first description of all major transcriptional mechanisms of tolerance to all antibiotics recommended in current guidelines, using RNA sequencing-guided experiments. M. abscessus ATCC 19977 bacteria were subjected to subinhibitory concentrations of clarithromycin (CLR), amikacin (AMK), tigecycline (TIG), cefoxitin (FOX), and clofazimine (CFZ) for 4 and 24 h, followed by RNA sequencing. To confirm key mechanisms of tolerance suggested by transcriptomic responses, we performed time-kill kinetic analysis using bacteria after preexposure to CLR, AMK, or TIG for 24 h and constructed isogenic knockout and knockdown strains. To assess strain specificity, pan-genome analysis of 35 strains from all three subspecies was performed. Mycobacterium abscessus shows both drug-specific and common transcriptomic responses to antibiotic exposure. Ribosome-targeting antibiotics CLR, AMK, and TIG elicit a common response characterized by upregulation of ribosome structural genes, the WhiB7 regulon and transferases, accompanied by downregulation of respiration through NuoA-N. Exposure to any of these drugs decreases susceptibility to ribosome-targeting drugs from multiple classes. The cytochrome bd-type quinol oxidase contributes to CFZ tolerance in M. abscessus, and the sigma factor sigH but not antisigma factor MAB_3542c is involved in TIG resistance. The observed transcriptomic responses are not strain-specific, as all genes involved in tolerance, except erm(41), are found in all included strains.
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Mekonnen D, Derbie A, Mihret A, Yimer SA, Tønjum T, Gelaw B, Nibret E, Munshae A, Waddell SJ, Aseffa A. Lipid droplets and the transcriptome of Mycobacterium tuberculosis from direct sputa: a literature review. Lipids Health Dis 2021; 20:129. [PMID: 34602073 PMCID: PMC8487580 DOI: 10.1186/s12944-021-01550-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 09/09/2021] [Indexed: 11/21/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb), the main etiology of tuberculosis (TB), is predominantly an intracellular pathogen that has caused infection, disease and death in humans for centuries. Lipid droplets (LDs) are dynamic intracellular organelles that are found across the evolutionary tree of life. This review is an evaluation of the current state of knowledge regarding Mtb-LD formation and associated Mtb transcriptome directly from sputa.Based on the LD content, Mtb in sputum may be classified into three groups: LD positive, LD negative and LD borderline. However, the clinical and evolutionary importance of each state is not well elaborated. Mounting evidence supports the view that the presence of LD positive Mtb bacilli in sputum is a biomarker of slow growth, low energy state, towards lipid degradation, and drug tolerance. In Mtb, LD may serve as a source of chemical energy, scavenger of toxic compounds, prevent destruction of Mtb through autophagy, delay trafficking of lysosomes towards the phagosome, and contribute to Mtb persistence. It is suggest that LD is a key player in the induction of a spectrum of phenotypic and metabolic states of Mtb in the macrophage, granuloma and extracellular sputum microenvironment. Tuberculosis patients with high proportion of LD positive Mtb in pretreatment sputum was associated with higher rate of poor treatment outcome, indicating that LD may have a clinical application in predicting treatment outcome.The propensity for LD formation among Mtb lineages is largely unknown. The role of LD on Mtb transmission and disease phenotype (pulmonary TB vs extra-pulmonary TB) is not well understood. Thus, further studies are needed to understand the relationships between LD positivity and Mtb lineage, Mtb transmission and clinical types.
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Affiliation(s)
- Daniel Mekonnen
- Department of Medical Microbiology, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia.
- Institute of Biotechnology, Bahir Dar University, Bahir Dar, Ethiopia.
| | - Awoke Derbie
- Department of Medical Microbiology, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
- Institute of Biotechnology, Bahir Dar University, Bahir Dar, Ethiopia
- The Centre for Innovative Drug Development and Therapeutic Trials for Africa (CDT-Africa), Addis Ababa University, Addis Ababa, Ethiopia
| | - Adane Mihret
- Armauer Hansen Research Institute, Jimma Road, ALERT Compound, PO Box 1005, Addis Ababa, Ethiopia
- Department of Medical Microbiology, Immunology and Parasitology, College of Medicine and Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Solomon Abebe Yimer
- Department of Microbiology, University of Oslo, PO Box 1071, Blindern, NO-0316, Oslo, Norway
- Coalition for Epidemic Preparedness Innovations, CEPI, P.O. Box 123, Torshov, 0412, Oslo, Norway
| | - Tone Tønjum
- Department of Microbiology, University of Oslo, PO Box 1071, Blindern, NO-0316, Oslo, Norway
- Department of Microbiology, Oslo University Hospital, PO Box 4950, Nydalen, NO-0424, Oslo, Norway
| | - Baye Gelaw
- Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Endalkachew Nibret
- Institute of Biotechnology, Bahir Dar University, Bahir Dar, Ethiopia
- Department of Biology, Bahir Dar University, Bahir Dar, Ethiopia
| | - Abaineh Munshae
- Institute of Biotechnology, Bahir Dar University, Bahir Dar, Ethiopia
- Department of Biology, Bahir Dar University, Bahir Dar, Ethiopia
| | - Simon J Waddell
- Department of Global Health and Infection, Brighton and Sussex Medical School, University of Sussex, Brighton, BN1 9PX, UK
| | - Abraham Aseffa
- Armauer Hansen Research Institute, Jimma Road, ALERT Compound, PO Box 1005, Addis Ababa, Ethiopia
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Mycobacterium tuberculosis VapC4 toxin engages small ORFs to initiate an integrated oxidative and copper stress response. Proc Natl Acad Sci U S A 2021; 118:2022136118. [PMID: 34362841 DOI: 10.1073/pnas.2022136118] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The Mycobacterium tuberculosis (Mtb) VapBC4 toxin-antitoxin system is essential for the establishment of Mtb infection. Using a multitier, systems-level approach, we uncovered the sequential molecular events triggered by the VapC4 toxin that activate a circumscribed set of critical stress survival pathways which undoubtedly underlie Mtb virulence. VapC4 exclusively inactivated the sole transfer RNACys (tRNACys) through cleavage at a single site within the anticodon sequence. Depletion of the pool of tRNACys led to ribosome stalling at Cys codons within actively translating messenger RNAs. Genome mapping of these Cys-stalled ribosomes unexpectedly uncovered several unannotated Cys-containing open reading frames (ORFs). Four of these are small ORFs (sORFs) encoding Cys-rich proteins of fewer than 50 amino acids that function as Cys-responsive attenuators that engage ribosome stalling at tracts of Cys codons to control translation of downstream genes. Thus, VapC4 mimics a state of Cys starvation, which then activates Cys attenuation at sORFs to globally redirect metabolism toward the synthesis of free Cys. The resulting newly enriched pool of Cys feeds into the synthesis of mycothiol, the glutathione counterpart in this pathogen that is responsible for maintaining cellular redox homeostasis during oxidative stress, as well as into a circumscribed subset of cellular pathways that enable cells to defend against oxidative and copper stresses characteristically endured by Mtb within macrophages. Our ability to pinpoint activation or down-regulation of pathways that collectively align with Mtb virulence-associated stress responses and the nonreplicating persistent state brings to light a direct and vital role for the VapC4 toxin in mediating these critical pathways.
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Surface-Shaving Proteomics of Mycobacterium marinum Identifies Biofilm Subtype-Specific Changes Affecting Virulence, Tolerance, and Persistence. mSystems 2021; 6:e0050021. [PMID: 34156290 PMCID: PMC8269238 DOI: 10.1128/msystems.00500-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The complex cell wall and biofilm matrix (ECM) act as key barriers to antibiotics in mycobacteria. Here, the ECM and envelope proteins of Mycobacterium marinum ATCC 927, a nontuberculous mycobacterial model, were monitored over 3 months by label-free proteomics and compared with cell surface proteins on planktonic cells to uncover pathways leading to virulence, tolerance, and persistence. We show that ATCC 927 forms pellicle-type and submerged-type biofilms (PBFs and SBFs, respectively) after 2 weeks and 2 days of growth, respectively, and that the increased CelA1 synthesis in this strain prevents biofilm formation and leads to reduced rifampicin tolerance. The proteomic data suggest that specific changes in mycolic acid synthesis (cord factor), Esx1 secretion, and cell wall adhesins explain the appearance of PBFs as ribbon-like cords and SBFs as lichen-like structures. A subpopulation of cells resisting 64× MIC rifampicin (persisters) was detected in both biofilm subtypes and already in 1-week-old SBFs. The key forces boosting their development could include subtype-dependent changes in asymmetric cell division, cell wall biogenesis, tricarboxylic acid/glyoxylate cycle activities, and energy/redox/iron metabolisms. The effect of various ambient oxygen tensions on each cell type and nonclassical protein secretion are likely factors explaining the majority of the subtype-specific changes. The proteomic findings also imply that Esx1-type protein secretion is more efficient in planktonic (PL) and PBF cells, while SBF may prefer both the Esx5 and nonclassical pathways to control virulence and prolonged viability/persistence. In conclusion, this study reports the first proteomic insight into aging mycobacterial biofilm ECMs and indicates biofilm subtype-dependent mechanisms conferring increased adaptive potential and virulence of nontuberculous mycobacteria. IMPORTANCE Mycobacteria are naturally resilient, and mycobacterial infections are notoriously difficult to treat with antibiotics, with biofilm formation being the main factor complicating the successful treatment of tuberculosis (TB). The present study shows that nontuberculous Mycobacterium marinum ATCC 927 forms submerged- and pellicle-type biofilms with lichen- and ribbon-like structures, respectively, as well as persister cells under the same conditions. We show that both biofilm subtypes differ in terms of virulence-, tolerance-, and persistence-conferring activities, highlighting the fact that both subtypes should be targeted to maximize the power of antimycobacterial treatment therapies.
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Usnic Acid Treatment Changes the Composition of Mycobacterium tuberculosis Cell Envelope and Alters Bacterial Redox Status. mSystems 2021; 6:6/3/e00097-21. [PMID: 33947802 PMCID: PMC8269206 DOI: 10.1128/msystems.00097-21] [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] [Indexed: 12/29/2022] Open
Abstract
Mycobacterium tuberculosis developed efficient adaptation mechanisms in response to different environmental conditions. This resulted in the ability to survive in human macrophages and in resistance to numerous antibiotics. To get insight into bacterial responses to potent antimycobacterial natural compounds, we tested how usnic acid, a lichen-derived secondary metabolite, would influence mycobacteria at transcriptomic and metabolomic levels. The analysis of expression of sigma factors revealed a profound impact of usnic acid on one of the primary genetic regulatory systems of M. tuberculosis Combined liquid chromatography-mass spectrometry and nuclear magnetic resonance analyses allowed us to observe the perturbations in metabolic pathways, as well as in lipid composition, which took place within 24 h of exposure. Early bacterial response was related to redox homeostasis, lipid synthesis, and nucleic acid repair. Usnic acid treatment provoked disturbances of redox state in mycobacterial cells and increased production of structural elements of the cell wall and cell membrane. In addition, to increase the number of molecules related to restoration of redox balance, the rearrangements of the cell envelope were the first defense mechanisms observed under usnic acid treatment.IMPORTANCE The evaluation of mechanisms of mycobacterial response to natural products has been barely studied. However, it might be helpful to reveal bacterial adaptation strategies, which are eventually crucial for the discovery of new drug targets and, hence, understanding the resistance mechanisms. This study showed that the first-line mycobacterial defense against usnic acid, a potent antimicrobial agent, is the remodeling of the cell envelope and restoring redox homeostasis. Transcriptomic data correlated with metabolomics analysis. The observed metabolic changes appeared similar to those exerted by antibiotics.
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Dong W, Nie X, Zhu H, Liu Q, Shi K, You L, Zhang Y, Fan H, Yan B, Niu C, Lyu LD, Zhao GP, Yang C. Mycobacterial fatty acid catabolism is repressed by FdmR to sustain lipogenesis and virulence. Proc Natl Acad Sci U S A 2021; 118:e2019305118. [PMID: 33853942 PMCID: PMC8072231 DOI: 10.1073/pnas.2019305118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Host-derived fatty acids are an important carbon source for pathogenic mycobacteria during infection. How mycobacterial cells regulate the catabolism of fatty acids to serve the pathogenicity, however, remains unknown. Here, we identified a TetR-family transcriptional factor, FdmR, as the key regulator of fatty acid catabolism in the pathogen Mycobacterium marinum by combining use of transcriptomics, chromatin immunoprecipitation followed by sequencing, dynamic 13C-based flux analysis, metabolomics, and lipidomics. An M. marinum mutant deficient in FdmR was severely attenuated in zebrafish larvae and adult zebrafish. The mutant showed defective growth but high substrate consumption on fatty acids. FdmR was identified as a long-chain acyl-coenzyme A (acyl-CoA)-responsive repressor of genes involved in fatty acid degradation and modification. We demonstrated that FdmR functions as a valve to direct the flux of exogenously derived fatty acids away from β-oxidation toward lipid biosynthesis, thereby avoiding the overactive catabolism and accumulation of biologically toxic intermediates. Moreover, we found that FdmR suppresses degradation of long-chain acyl-CoAs endogenously synthesized through the type I fatty acid synthase. By modulating the supply of long-chain acyl-CoAs for lipogenesis, FdmR controls the abundance and chain length of virulence-associated lipids and mycolates and plays an important role in the impermeability of the cell envelope. These results reveal that despite the fact that host-derived fatty acids are used as an important carbon source, overactive catabolism of fatty acids is detrimental to mycobacterial cell growth and pathogenicity. This study thus presents FdmR as a potentially attractive target for chemotherapy.
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Affiliation(s)
- Wenyue Dong
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoqun Nie
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China
| | - Hong Zhu
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China
| | - Qingyun Liu
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115
| | - Kunxiong Shi
- Key Laboratory of Medical Molecular Virology of the Ministry of Education/National Health Commission/Chinese Academy of Medical Sciences (MOE/NHC/CAMS), School of Basic Medical Sciences, Department of Microbiology, School of Life Sciences, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200000, China
| | - Linlin You
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Zhang
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China
| | - Hongyan Fan
- Key Laboratory of Medical Molecular Virology of the Ministry of Education/National Health Commission/Chinese Academy of Medical Sciences (MOE/NHC/CAMS), School of Basic Medical Sciences, Department of Microbiology, School of Life Sciences, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200000, China
| | - Bo Yan
- Key Laboratory of Medical Molecular Virology of the Ministry of Education/National Health Commission/Chinese Academy of Medical Sciences (MOE/NHC/CAMS), School of Basic Medical Sciences, Department of Microbiology, School of Life Sciences, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200000, China
| | - Chen Niu
- Key Laboratory of Medical Molecular Virology of the Ministry of Education/National Health Commission/Chinese Academy of Medical Sciences (MOE/NHC/CAMS), School of Basic Medical Sciences, Department of Microbiology, School of Life Sciences, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200000, China;
| | - Liang-Dong Lyu
- Key Laboratory of Medical Molecular Virology of the Ministry of Education/National Health Commission/Chinese Academy of Medical Sciences (MOE/NHC/CAMS), School of Basic Medical Sciences, Department of Microbiology, School of Life Sciences, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200000, China;
| | - Guo-Ping Zhao
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China
- Key Laboratory of Medical Molecular Virology of the Ministry of Education/National Health Commission/Chinese Academy of Medical Sciences (MOE/NHC/CAMS), School of Basic Medical Sciences, Department of Microbiology, School of Life Sciences, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200000, China
- Bio-Med Big Data Center, CAS Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai 200032, China
| | - Chen Yang
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China;
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Abstract
Endospore formation is used by members of the phylum Firmicutes to withstand extreme environmental conditions. Several recent studies have proposed endospore formation in species outside of Firmicutes, particularly in Rhodobacter johrii and Serratia marcescens, members of the phylum Proteobacteria. Here, we aimed to investigate endospore formation in these two species by using advanced imaging and analytical approaches. Examination of the phase-bright structures observed in R. johrii and S. marcescens using cryo-electron tomography failed to identify endospores or stages of endospore formation. We determined that the phase-bright objects in R. johrii cells were triacylglycerol storage granules and those in S. marcescens were aggregates of cellular debris. In addition, R. johrii and S. marcescens containing phase-bright objects do not possess phenotypic and genetic features of endospores, including enhanced resistance to heat, presence of dipicolinic acid, or the presence of many of the genes associated with endospore formation. Our results support the hypothesis that endospore formation is restricted to the phylum Firmicutes.Importance: Bacterial endospore formation is an important process that allows the formation of dormant life forms called spores. As such, organisms able to sporulate can survive harsh environmental conditions for hundreds of years. Here, we follow up on previous claims that two members of Proteobacteria, Serratia marcescens and Rhodobacter johrii, are able to form spores. We conclude that those claims were incorrect and show that the putative spores in R. johrii and S. marcescens are storage granules and cellular debris, respectively. This study concludes that endospore formation is still unique to the phylum Firmicutes.
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Abstract
Intracellular proliferation of Legionella pneumophila within a vacuole in human alveolar macrophages is essential for manifestation of Legionnaires’ pneumonia. Intravacuolar growth of the pathogen is totally dependent on remodeling the L. pneumophila-containing vacuole (LCV) by the ER and on its evasion of the endosomal-lysosomal degradation pathway. Diversion of the Legionella pneumophila-containing vacuole (LCV) from the host endosomal-lysosomal degradation pathway is one of the main virulence features essential for manifestation of Legionnaires’ pneumonia. Many of the ∼350 Dot/Icm-injected effectors identified in L. pneumophila have been shown to interfere with various host pathways and processes, but no L. pneumophila effector has ever been identified to be indispensable for lysosomal evasion. While most single effector mutants of L. pneumophila do not exhibit a defective phenotype within macrophages, we show that the MavE effector is essential for intracellular growth of L. pneumophila in human monocyte-derived macrophages (hMDMs) and amoebae and for intrapulmonary proliferation in mice. The mavE null mutant fails to remodel the LCV with endoplasmic reticulum (ER)-derived vesicles and is trafficked to the lysosomes where it is degraded, similar to formalin-killed bacteria. During infection of hMDMs, the MavE effector localizes to the poles of the LCV membrane. The crystal structure of MavE, resolved to 1.8 Å, reveals a C-terminal transmembrane helix, three copies of tyrosine-based sorting motifs, and an NPxY eukaryotic motif, which binds phosphotyrosine-binding domains present on signaling and adaptor eukaryotic proteins. Two point mutations within the NPxY motif result in attenuation of L. pneumophila in both hMDMs and amoeba. The substitution defects of P78 and D64 are associated with failure of vacuoles harboring the mutant to be remodeled by the ER and results in fusion of the vacuole to the lysosomes leading to bacterial degradation. Therefore, the MavE effector of L. pneumophila is indispensable for phagosome biogenesis and lysosomal evasion.
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Price CT, Abu Kwaik Y. Evolution and Adaptation of Legionella pneumophila to Manipulate the Ubiquitination Machinery of Its Amoebae and Mammalian Hosts. Biomolecules 2021; 11:biom11010112. [PMID: 33467718 PMCID: PMC7830128 DOI: 10.3390/biom11010112] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 02/07/2023] Open
Abstract
The ubiquitin pathway is highly conserved across the eukaryotic domain of life and plays an essential role in a plethora of cellular processes. It is not surprising that many intracellular bacterial pathogens often target the essential host ubiquitin pathway. The intracellular bacterial pathogen Legionella pneumophila injects into the host cell cytosol multiple classes of classical and novel ubiquitin-modifying enzymes that modulate diverse ubiquitin-related processes in the host cell. Most of these pathogen-injected proteins, designated as effectors, mimic known E3-ubiquitin ligases through harboring F-box or U-box domains. The classical F-box effector, AnkB targets host proteins for K48-linked polyubiquitination, which leads to excessive proteasomal degradation that is required to generate adequate supplies of amino acids for metabolism of the pathogen. In contrast, the SidC and SdcA effectors share no structural similarity to known eukaryotic ligases despite having E3-ubiquitin ligase activity, suggesting that the number of E3-ligases in eukaryotes is under-represented. L. pneumophila also injects into the host many novel ubiquitin-modifying enzymes, which are the SidE family of effectors that catalyze phosphoribosyl-ubiquitination of serine residue of target proteins, independently of the canonical E1-2-3 enzymatic cascade. Interestingly, the environmental bacterium, L. pneumophila, has evolved within a diverse range of amoebal species, which serve as the natural hosts, while accidental transmission through contaminated aerosols can cause pneumonia in humans. Therefore, it is likely that the novel ubiquitin-modifying enzymes of L. pneumophila were acquired by the pathogen through interkingdom gene transfer from the diverse natural amoebal hosts. Furthermore, conservation of the ubiquitin pathway across eukaryotes has enabled these novel ubiquitin-modifying enzymes to function similarly in mammalian cells. Studies on the biological functions of these effectors are likely to reveal further novel ubiquitin biology and shed further lights on the evolution of ubiquitin.
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Affiliation(s)
- Christopher T.D. Price
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202, USA;
| | - Yousef Abu Kwaik
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202, USA;
- Center for Predictive Medicine, College of Medicine, University of Louisville, Louisville, KY 40202, USA
- Correspondence:
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Eisenreich W, Rudel T, Heesemann J, Goebel W. Persistence of Intracellular Bacterial Pathogens-With a Focus on the Metabolic Perspective. Front Cell Infect Microbiol 2021; 10:615450. [PMID: 33520740 PMCID: PMC7841308 DOI: 10.3389/fcimb.2020.615450] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 11/30/2020] [Indexed: 12/19/2022] Open
Abstract
Persistence has evolved as a potent survival strategy to overcome adverse environmental conditions. This capability is common to almost all bacteria, including all human bacterial pathogens and likely connected to chronic infections caused by some of these pathogens. Although the majority of a bacterial cell population will be killed by the particular stressors, like antibiotics, oxygen and nitrogen radicals, nutrient starvation and others, a varying subpopulation (termed persisters) will withstand the stress situation and will be able to revive once the stress is removed. Several factors and pathways have been identified in the past that apparently favor the formation of persistence, such as various toxin/antitoxin modules or stringent response together with the alarmone (p)ppGpp. However, persistence can occur stochastically in few cells even of stress-free bacterial populations. Growth of these cells could then be induced by the stress conditions. In this review, we focus on the persister formation of human intracellular bacterial pathogens, some of which belong to the most successful persister producers but lack some or even all of the assumed persistence-triggering factors and pathways. We propose a mechanism for the persister formation of these bacterial pathogens which is based on their specific intracellular bipartite metabolism. We postulate that this mode of metabolism ultimately leads, under certain starvation conditions, to the stalling of DNA replication initiation which may be causative for the persister state.
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Affiliation(s)
- Wolfgang Eisenreich
- Department of Chemistry, Chair of Biochemistry, Technische Universität München, Garching, Germany
| | - Thomas Rudel
- Chair of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Jürgen Heesemann
- Max von Pettenkofer-Institute, Ludwig Maximilian University of Munich, München, Germany
| | - Werner Goebel
- Max von Pettenkofer-Institute, Ludwig Maximilian University of Munich, München, Germany
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Fannin S, Rangel J, Bodurin AP, Yu T, Mistretta B, Mali S, Gunaratne P, Bark SJ, Ebalunode JO, Khan A, Widger WR, Sen M. Functional and structural characterization of Hyp730, a highly conserved and dormancy-specific hypothetical membrane protein. Microbiologyopen 2021; 10:e1154. [PMID: 33650800 PMCID: PMC7856521 DOI: 10.1002/mbo3.1154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 12/08/2020] [Accepted: 12/15/2020] [Indexed: 11/27/2022] Open
Abstract
Membrane proteins represent major drug targets, and the ability to determine their functions, structures, and conformational changes will significantly advance mechanistic approaches to both biotechnology and bioremediation, as well as the fight against pathogenic bacteria. A pertinent example is Mycobacterium tuberculosis (H37Rv), which contains ~4000 protein-coding genes, with almost a thousand having been categorized as 'membrane protein', and a few of which (~1%) have been functionally characterized and structurally modeled. However, the functions and structures of most membrane proteins that are sparsely, or only transiently, expressed, but essential in small phenotypic subpopulations or under stress conditions such as persistence or dormancy, remain unknown. Our deep quantitative proteomics profiles revealed that the hypothetical membrane protein 730 (Hyp730) WP_010079730 (protein ID Mlut_RS11895) from M. luteus is upregulated in dormancy despite a ~5-fold reduction in overall protein diversity. Its H37Rv paralog, Rv1234, showed a similar proteomic signature, but the function of Hyp730-like proteins has never been characterized. Here, we present an extensive proteomic and transcriptomic analysis of Hyp730 and have also characterized its in vitro recombinant expression, purification, refolding, and essentiality as well as its tertiary fold. Our biophysical studies, circular dichroism, and tryptophan fluorescence are in immediate agreement with in-depth in silico 3D-structure prediction, suggesting that Hyp730 is a double-pass membrane-spanning protein. Ablation of Hyp730-expression did not alter M. luteus growth, indicating that Hyp730 is not essential. Structural homology comparisons showed that Hyp730 is highly conserved and non-redundant in G+C rich Actinobacteria and might be involved, under stress conditions, in an energy-saving role in respiration during dormancy.
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Affiliation(s)
- Stewart Fannin
- Department of Biology and BiochemistryUniversity of HoustonHoustonTXUSA
| | - Jonathan Rangel
- Department of Biology and BiochemistryUniversity of HoustonHoustonTXUSA
| | | | - Tannon Yu
- Department of MathematicsUniversity of HoustonHoustonTXUSA
- Present address:
Division of Operational InsightTexas Workforce CommissionAustinTXUSA
| | - Brandon Mistretta
- Department of Biology and BiochemistryUniversity of HoustonHoustonTXUSA
| | - Sujina Mali
- Department of Biology and BiochemistryUniversity of HoustonHoustonTXUSA
| | - Preethi Gunaratne
- Department of Biology and BiochemistryUniversity of HoustonHoustonTXUSA
| | - Steven J. Bark
- Department of Biology and BiochemistryUniversity of HoustonHoustonTXUSA
| | - Jerry O. Ebalunode
- Hewlett Packard Enterprise Data Science InstituteUniversity of HoustonHoustonTXUSA
| | - Arshad Khan
- Department of Pathology & Genomic MedicineCenter for Infectious Disease Houston Methodist Research InstituteHoustonTXUSA
| | - William R. Widger
- Department of Biology and BiochemistryUniversity of HoustonHoustonTXUSA
| | - Mehmet Sen
- Department of Biology and BiochemistryUniversity of HoustonHoustonTXUSA
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Hanford HE, Von Dwingelo J, Abu Kwaik Y. Bacterial nucleomodulins: A coevolutionary adaptation to the eukaryotic command center. PLoS Pathog 2021; 17:e1009184. [PMID: 33476322 PMCID: PMC7819608 DOI: 10.1371/journal.ppat.1009184] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Through long-term interactions with their hosts, bacterial pathogens have evolved unique arsenals of effector proteins that interact with specific host targets and reprogram the host cell into a permissive niche for pathogen proliferation. The targeting of effector proteins into the host cell nucleus for modulation of nuclear processes is an emerging theme among bacterial pathogens. These unique pathogen effector proteins have been termed in recent years as "nucleomodulins." The first nucleomodulins were discovered in the phytopathogens Agrobacterium and Xanthomonas, where their nucleomodulins functioned as eukaryotic transcription factors or integrated themselves into host cell DNA to promote tumor induction, respectively. Numerous nucleomodulins were recently identified in mammalian pathogens. Bacterial nucleomodulins are an emerging family of pathogen effector proteins that evolved to target specific components of the host cell command center through various mechanisms. These mechanisms include: chromatin dynamics, histone modification, DNA methylation, RNA splicing, DNA replication, cell cycle, and cell signaling pathways. Nucleomodulins may induce short- or long-term epigenetic modifications of the host cell. In this extensive review, we discuss the current knowledge of nucleomodulins from plant and mammalian pathogens. While many nucleomodulins are already identified, continued research is instrumental in understanding their mechanisms of action and the role they play during the progression of pathogenesis. The continued study of nucleomodulins will enhance our knowledge of their effects on nuclear chromatin dynamics, protein homeostasis, transcriptional landscapes, and the overall host cell epigenome.
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Affiliation(s)
- Hannah E. Hanford
- Department of Microbiology and Immunology, University of Louisville, Kentucky, United States of America
| | - Juanita Von Dwingelo
- Department of Microbiology and Immunology, University of Louisville, Kentucky, United States of America
| | - Yousef Abu Kwaik
- Department of Microbiology and Immunology, University of Louisville, Kentucky, United States of America
- Center for Predicative Medicine, College of Medicine, University of Louisville, Kentucky, United States of America
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Zebrafish Embryo Model for Assessment of Drug Efficacy on Mycobacterial Persisters. Antimicrob Agents Chemother 2020; 64:AAC.00801-20. [PMID: 32778551 DOI: 10.1128/aac.00801-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 08/03/2020] [Indexed: 01/21/2023] Open
Abstract
Tuberculosis continues to kill millions of people each year. The main difficulty in eradication of the disease is the prolonged duration of treatment, which takes at least 6 months. Persister cells have long been associated with failed treatment and disease relapse because of their phenotypical, though transient, tolerance to drugs. By targeting these persisters, the duration of treatment could be shortened, leading to improved tuberculosis treatment and a reduction in transmission. The unique in vivo environment drives the generation of persisters; however, appropriate in vivo mycobacterial persister models enabling optimized drug screening are lacking. To set up a persister infection model that is suitable for this, we infected zebrafish embryos with in vitro-starved Mycobacterium marinum In vitro starvation resulted in a persister-like phenotype with the accumulation of stored neutral lipids and concomitant increased tolerance to ethambutol. However, these starved wild-type M. marinum organisms rapidly lost their persister phenotype in vivo To prolong the persister phenotype in vivo, we subsequently generated and analyzed mutants lacking functional resuscitation-promoting factors (Rpfs). Interestingly, the ΔrpfAB mutant, lacking two Rpfs, established an infection in vivo, whereas a nutrient-starved ΔrpfAB mutant did maintain its persister phenotype in vivo This mutant was, after nutrient starvation, also tolerant to ethambutol treatment in vivo, as would be expected for persisters. We propose that this zebrafish embryo model with ΔrpfAB mutant bacteria is a valuable addition for drug screening purposes and specifically screens to target mycobacterial persisters.
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Boldrin F, Provvedi R, Cioetto Mazzabò L, Segafreddo G, Manganelli R. Tolerance and Persistence to Drugs: A Main Challenge in the Fight Against Mycobacterium tuberculosis. Front Microbiol 2020; 11:1924. [PMID: 32983003 PMCID: PMC7479264 DOI: 10.3389/fmicb.2020.01924] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/21/2020] [Indexed: 12/18/2022] Open
Abstract
The treatment of tuberculosis is extremely long. One of the reasons why Mycobacterium tuberculosis elimination from the organism takes so long is that in particular environmental conditions it can become tolerant to drugs and/or develop persisters able to survive killing even from very high drug concentrations. Tolerance develops in response to a harsh environment exposure encountered by bacteria during infection, mainly due to the action of the immune system, whereas persistence results from the presence of heterogeneous bacterial populations with different degrees of drug sensitivity, and can be induced by exposure to stress conditions. Here, we review the actual knowledge on the stress response mechanisms enacted by M. tuberculosis during infection, which leads to increased drug tolerance or development of a highly drug-resistant subpopulation.
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Affiliation(s)
- Francesca Boldrin
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | | | | | - Greta Segafreddo
- Department of Molecular Medicine, University of Padova, Padova, Italy
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Coskun FS, Srivastava S, Raj P, Dozmorov I, Belkaya S, Mehra S, Golden NA, Bucsan AN, Chapagain ML, Wakeland EK, Kaushal D, Gumbo T, van Oers NSC. sncRNA-1 Is a Small Noncoding RNA Produced by Mycobacterium tuberculosis in Infected Cells That Positively Regulates Genes Coupled to Oleic Acid Biosynthesis. Front Microbiol 2020; 11:1631. [PMID: 32849337 PMCID: PMC7399025 DOI: 10.3389/fmicb.2020.01631] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/23/2020] [Indexed: 12/21/2022] Open
Abstract
Nearly one third of the world’s population is infected with Mycobacterium tuberculosis (Mtb). While much work has focused on the role of different Mtb encoded proteins in pathogenesis, recent studies have revealed that Mtb also transcribes many noncoding RNAs whose functions remain poorly characterized. We performed RNA sequencing and identified a subset of Mtb H37Rv-encoded small RNAs (<30 nts in length) that were produced in infected macrophages. Designated as smaller noncoding RNAs (sncRNAs), three of these predominated the read counts. Each of the three, sncRNA-1, sncRNA-6, and sncRNA-8 had surrounding sequences with predicted stable secondary RNA stem loops. Site-directed mutagenesis of the precursor sequences suggest the existence of a hairpin loop dependent RNA processing mechanism. A functional assessment of sncRNA-1 suggested that it positively regulated two mycobacterial transcripts involved in oleic acid biosynthesis. Complementary loss- and gain- of-function approaches revealed that sncRNA-1 positively supports Mtb growth and survival in nutrient-depleted cultures as well as in infected macrophages. Overall, the findings reveal that Mtb produces sncRNAs in infected cells, with sncRNA-1 modulating mycobacterial gene expression including genes coupled to oleic acid biogenesis.
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Affiliation(s)
- Fatma S Coskun
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Shashikant Srivastava
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, TX, United States
| | - Prithvi Raj
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Igor Dozmorov
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Serkan Belkaya
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Smriti Mehra
- Tulane National Primate Research Center, School of Medicine, Tulane University, Covington, LA, United States
| | - Nadia A Golden
- Tulane National Primate Research Center, School of Medicine, Tulane University, Covington, LA, United States
| | - Allison N Bucsan
- Tulane National Primate Research Center, School of Medicine, Tulane University, Covington, LA, United States
| | - Moti L Chapagain
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, TX, United States
| | - Edward K Wakeland
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Deepak Kaushal
- Tulane National Primate Research Center, School of Medicine, Tulane University, Covington, LA, United States.,Texas Biomedical Research Institute, San Antonio, TX, United States
| | - Tawanda Gumbo
- Center for Infectious Diseases Research and Experimental Therapeutics, Baylor Research Institute, Baylor University Medical Center, Dallas, TX, United States
| | - Nicolai S C van Oers
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States
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37
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Sarathy JP, Dartois V. Caseum: a Niche for Mycobacterium tuberculosis Drug-Tolerant Persisters. Clin Microbiol Rev 2020; 33:e00159-19. [PMID: 32238365 PMCID: PMC7117546 DOI: 10.1128/cmr.00159-19] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Caseum, the central necrotic material of tuberculous lesions, is a reservoir of drug-recalcitrant persisting mycobacteria. Caseum is found in closed nodules and in open cavities connecting with an airway. Several commonly accepted characteristics of caseum were established during the preantibiotic era, when autopsies of deceased tuberculosis (TB) patients were common but methodologies were limited. These pioneering studies generated concepts such as acidic pH, low oxygen tension, and paucity of nutrients being the drivers of nonreplication and persistence in caseum. Here we review widely accepted beliefs about the caseum-specific stress factors thought to trigger the shift of Mycobacterium tuberculosis to drug tolerance. Our current state of knowledge reveals that M. tuberculosis is faced with a lipid-rich diet rather than nutrient deprivation in caseum. Variable caseum pH is seen across lesions, possibly transiently acidic in young lesions but overall near neutral in most mature lesions. Oxygen tension is low in the avascular caseum of closed nodules and high at the cavity surface, and a gradient of decreasing oxygen tension likely forms toward the cavity wall. Since caseum is largely made of infected and necrotized macrophages filled with lipid droplets, the microenvironmental conditions encountered by M. tuberculosis in foamy macrophages and in caseum bear many similarities. While there remain a few knowledge gaps, these findings constitute a solid starting point to develop high-throughput drug discovery assays that combine the right balance of oxygen tension, pH, lipid abundance, and lipid species to model the profound drug tolerance of M. tuberculosis in caseum.
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Affiliation(s)
- Jansy P Sarathy
- Center for Discovery and Innovation, Hackensack Meridian School of Medicine at Seton Hall University, Nutley, New Jersey, USA
| | - Véronique Dartois
- Center for Discovery and Innovation, Hackensack Meridian School of Medicine at Seton Hall University, Nutley, New Jersey, USA
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38
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McClean CM, Tobin DM. Early cell-autonomous accumulation of neutral lipids during infection promotes mycobacterial growth. PLoS One 2020; 15:e0232251. [PMID: 32407412 PMCID: PMC7224534 DOI: 10.1371/journal.pone.0232251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 04/12/2020] [Indexed: 11/19/2022] Open
Abstract
Lipids represent an important source of nutrition for infecting mycobacteria, accumulating within the necrotic core of granulomas and present in foamy macrophages associated with mycobacterial infection. In order to better understand the timing, process and importance of lipid accumulation, we developed methods for direct in vivo visualization and quantification of this process using the zebrafish-M. marinum larval model of infection. We find that neutral lipids accumulate cell-autonomously in mycobacterium-infected macrophages in vivo during early infection, with detectable levels of accumulation by two days post-infection. Treatment with ezetimibe, an FDA-approved drug, resulted in decreased levels of free cholesterol and neutral lipids, and a reduction of bacterial growth in vivo. The effect of ezetimibe in reducing bacterial growth was dependent on the mce4 operon, a key bacterial determinant of lipid utilization. Thus, in vivo, lipid accumulation can occur cell-autonomously at early timepoints of mycobacterial infection, and limitation of this process results in decreased bacterial burden.
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Affiliation(s)
- Colleen M. McClean
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, United States of America
- Department of Immunology, Duke University School of Medicine, Durham, North Carolina, United States of America
- Medical Scientist Training Program, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - David M. Tobin
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, United States of America
- Department of Immunology, Duke University School of Medicine, Durham, North Carolina, United States of America
- * E-mail:
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