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Rafiepour P, Sina S, Amoli ZA, Shekarforoush SS, Farajzadeh E, Mortazavi SMJ. A mechanistic simulation of induced DNA damage in a bacterial cell by X- and gamma rays: a parameter study. Phys Eng Sci Med 2024; 47:1015-1035. [PMID: 38652348 DOI: 10.1007/s13246-024-01424-x] [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: 08/27/2023] [Accepted: 04/07/2024] [Indexed: 04/25/2024]
Abstract
Mechanistic Monte Carlo simulations calculating DNA damage caused by ionizing radiation are highly dependent on the simulation parameters. In the present study, using the Geant4-DNA toolkit, the impact of different parameters on DNA damage induced in a bacterial cell by X- and gamma-ray irradiation was investigated. Three geometry configurations, including the simple (without DNA details), the random (a random multiplication of identical DNA segments), and the fractal (a regular replication of DNA segments using fractal Hilbert curves), were simulated. Also, three physics constructors implemented in Geant4-DNA, i.e., G4EmDNAPhysics_option2, G4EmDNAPhysics_option4, and G4EmDNAPhysics_option6, with two energy thresholds of 17.5 eV and 5-37.5 eV were compared for direct DNA damage calculations. Finally, a previously developed mathematical model of cell repair called MEDRAS (Mechanistic DNA Repair and Survival) was employed to compare the impact of physics constructors on the cell survival curve. The simple geometry leads to undesirable results compared to the random and fractal ones, highlighting the importance of simulating complex DNA structures in mechanistic simulation studies. Under the same conditions, the DNA damage calculated in the fractal geometry was more consistent with the experimental data. All physics constructors can be used alternatively with the fractal geometry, provided that an energy threshold of 17.5 eV is considered for recording direct DNA damage. All physics constructors represent a similar behavior in generating cell survival curves, although the slopes of the curves are different. Since the inverse of the slope of a bacterial cell survival curve (i.e., the D10-value) is highly sensitive to the simulation parameters, it is not logical to determine an optimal set of parameters for calculating the D10-value by Monte Carlo simulation.
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Affiliation(s)
- Payman Rafiepour
- Department of Nuclear Engineering, School of Mechanical Engineering, Shiraz University, Shiraz, Iran
| | - Sedigheh Sina
- Department of Nuclear Engineering, School of Mechanical Engineering, Shiraz University, Shiraz, Iran.
- Radiation research center, School of Mechanical Engineering, Shiraz University, Shiraz, Iran.
| | - Zahra Alizadeh Amoli
- Department of Food Hygiene and Public Health, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| | - Seyed Shahram Shekarforoush
- Department of Food Hygiene and Public Health, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| | - Ebrahim Farajzadeh
- Secondary Standard Dosimetry Laboratory (SSDL), Pars Isotope Co, Karaj, Iran
| | - Seyed Mohammad Javad Mortazavi
- Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC), Shiraz University of Medical Sciences, Shiraz, Iran
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2
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Biba DA, Wolf YI, Koonin EV, Rochman ND. Balance between asymmetric allocation and repair of somatic damage in unicellular life forms as an ancient form of r/K selection. Proc Natl Acad Sci U S A 2024; 121:e2400008121. [PMID: 38787879 PMCID: PMC11145259 DOI: 10.1073/pnas.2400008121] [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: 01/01/2024] [Accepted: 04/24/2024] [Indexed: 05/26/2024] Open
Abstract
Over the course of multiple divisions, cells accumulate diverse nongenetic, somatic damage including misfolded and aggregated proteins and cell wall defects. If the rate of damage accumulation exceeds the rate of dilution through cell growth, a dedicated mitigation strategy is required to prevent eventual population collapse. Strategies for somatic damage control can be divided into two categories, asymmetric allocation and repair, which are not, in principle, mutually exclusive. We explore a mathematical model to identify the optimal strategy, maximizing the total cell number, over a wide range of environmental and physiological conditions. The optimal strategy is primarily determined by extrinsic, damage-independent mortality and the physiological model for damage accumulation that can be either independent (linear) or increasing (exponential) with respect to the prior accumulated damage. Under the linear regime, the optimal strategy is either exclusively repair or asymmetric allocation, whereas under the exponential regime, the optimal strategy is a combination of asymmetry and repair. Repair is preferred when extrinsic mortality is low, whereas at high extrinsic mortality, asymmetric damage allocation becomes the strategy of choice. We hypothesize that at an early stage of life evolution, optimization over repair and asymmetric allocation of somatic damage gave rise to r and K selection strategists.
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Affiliation(s)
- Dmitry A. Biba
- National Center for Biotechnology Information, National Library of Medicine, NIH, Bethesda, MD20894
- Oak Ridge Institute for Science and Education, Oak Ridge, TN37830
| | - Yuri I. Wolf
- National Center for Biotechnology Information, National Library of Medicine, NIH, Bethesda, MD20894
| | - Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, NIH, Bethesda, MD20894
| | - Nash D. Rochman
- National Center for Biotechnology Information, National Library of Medicine, NIH, Bethesda, MD20894
- Institute for Implementation Science in Population Health, City University of New York, New York, NY10027
- Department of Epidemiology and Biostatistics, Graduate School of Public Health and Health Policy City, University of New York, New York, NY10027
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3
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Wang X, Cao H, Zhu Y, Zhou T, Teng F, Tao Y. β-cyclocitral induced rapid cell death of Microcystis aeruginosa. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 348:123824. [PMID: 38513945 DOI: 10.1016/j.envpol.2024.123824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 03/07/2024] [Accepted: 03/18/2024] [Indexed: 03/23/2024]
Abstract
β-cyclocitral (BCC) is an odorous compound that can be produced by bloom-forming cyanobacteria, for example, Microcystis aeruginosa. BCC has been proposed to explain the rapid decline of cyanobacterial blooms in natural water bodies due to its lytic effects on cyanobacteria cells. However, few insights have been gained regarding the mechanisms of its lethality on cyanobacteria. In this study, M. aeruginosa was exposed to 0-300 mg/L BCC, and the physiological responses were comprehensively studied at the cellular, molecular, and transcriptomic levels. The result indicated that the lethal effect was concentration-dependent; 100 mg/L BCC only caused recoverable stress, while 150-300 mg/L BCC caused rapid rupture of cyanobacterial cells. Scanning electron microscope images suggested two typical morphological changes exposed to above 150 mg/LBCC: wrinkled/shrank with limited holes on the surface at 150 and 200 mg/L BCC exposure; no apparent shrinkage at the surface but with cell perforation at 250 and 300 mg/L BCC exposure. BCC can rapidly inhibit the photosynthetic activity of M. aeruginosa cells (40%∼100% decreases for 100-300 mg/L BCC) and significantly down-regulate photosynthetic system Ⅰ-related genes. Also, chlorophyll a (by 30%∼90%) and ATP (by ∼80%) contents severely decreased, suggesting overwhelming pressure on the energy metabolism in cells. Glutathione levels increased significantly, and stress response-related genes were upregulated, indicating the perturbation of intracellular redox homeostasis. Two cell death pathways were proposed to explain the lethal effect: apoptosis-like death as revealed by the upregulation of SOS response genes when exposed to 200 mg/L BCC and mazEF-mediated death as revealed by the upregulation of mazEF system genes when exposed to 300 mg/L BCC. Results of the current work not only provide insights into the potential role of BCC in inducing programmed cell death during bloom demise but also indicate the potential of using BCC for harmful algal control.
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Affiliation(s)
- Xuejian Wang
- Groundwater Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, 518055, China; Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, 518055, China
| | - Huansheng Cao
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan, 215316, China
| | - Yinjie Zhu
- Groundwater Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, 518055, China; Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, 518055, China
| | - Tingru Zhou
- Groundwater Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, 518055, China; Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, 518055, China
| | - Fei Teng
- Groundwater Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, 518055, China; Shenzhen Key Laboratory of Ecological Remediation and Carbon Sequestration, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, 518055, China
| | - Yi Tao
- Groundwater Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, 518055, China; Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, 518055, China; Shenzhen Key Laboratory of Ecological Remediation and Carbon Sequestration, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, 518055, China; Tsinghua University-Kunming Joint Research Center for Dianchi Plateau Lake, Tsinghua University, Beijing, 100084, China.
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4
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Jin C, Kang SM, Kim DH, Lee Y, Lee BJ. Discovery of Antimicrobial Agents Based on Structural and Functional Study of the Klebsiella pneumoniae MazEF Toxin-Antitoxin System. Antibiotics (Basel) 2024; 13:398. [PMID: 38786127 PMCID: PMC11117207 DOI: 10.3390/antibiotics13050398] [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: 03/20/2024] [Revised: 04/15/2024] [Accepted: 04/22/2024] [Indexed: 05/25/2024] Open
Abstract
Klebsiella pneumoniae causes severe human diseases, but its resistance to current antibiotics is increasing. Therefore, new antibiotics to eradicate K. pneumoniae are urgently needed. Bacterial toxin-antitoxin (TA) systems are strongly correlated with physiological processes in pathogenic bacteria, such as growth arrest, survival, and apoptosis. By using structural information, we could design the peptides and small-molecule compounds that can disrupt the binding between K. pneumoniae MazE and MazF, which release free MazF toxin. Because the MazEF system is closely implicated in programmed cell death, artificial activation of MazF can promote cell death of K. pneumoniae. The effectiveness of a discovered small-molecule compound in bacterial cell killing was confirmed through flow cytometry analysis. Our findings can contribute to understanding the bacterial MazEF TA system and developing antimicrobial agents for treating drug-resistant K. pneumoniae.
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Affiliation(s)
- Chenglong Jin
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea;
- Mastermeditech Ltd., Gangseo-gu, Seoul 16499, Republic of Korea
| | - Sung-Min Kang
- College of Pharmacy, Duksung Women’s University, Seoul 01369, Republic of Korea;
| | - Do-Hee Kim
- College of Pharmacy, Sookmyung Women’s University, Seoul 04310, Republic of Korea;
| | - Yuno Lee
- Korea Research Institute of Chemical Technology, Korea Chemical Bank Daejeon, Daejeon 34114, Republic of Korea;
| | - Bong-Jin Lee
- Mastermeditech Ltd., Gangseo-gu, Seoul 16499, Republic of Korea
- College of Pharmacy, Ajou University, Yeongtong-gu, Suwon 16499, Republic of Korea
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Wang XR, Cull B, Oliver JD, Kurtti TJ, Munderloh UG. The role of autophagy in tick-endosymbiont interactions: insights from Ixodes scapularis and Rickettsia buchneri. Microbiol Spectr 2024; 12:e0108623. [PMID: 38038450 PMCID: PMC10783069 DOI: 10.1128/spectrum.01086-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 10/27/2023] [Indexed: 12/02/2023] Open
Abstract
IMPORTANCE Ticks are second only to mosquitoes in their importance as vectors of disease agents; however, tick-borne diseases (TBDs) account for the majority of all vector-borne disease cases in the United States (approximately 76.5%), according to Centers for Disease Control and Prevention reports. Newly discovered tick species and their associated disease-causing pathogens, and anthropogenic and demographic factors also contribute to the emergence and re-emergence of TBDs. Thus, incorporating different tick control approaches based on a thorough knowledge of tick biology has great potential to prevent and eliminate TBDs in the future. Here we demonstrate that replication of a transovarially transmitted rickettsial endosymbiont depends on the tick's autophagy machinery but not on apoptosis. Our findings improve our understanding of the role of symbionts in tick biology and the potential to discover tick control approaches to prevent or manage TBDs.
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Affiliation(s)
- Xin-Ru Wang
- Department of Entomology, University of Minnesota, St. Paul, Minnesota, USA
- SUNY Center for Vector-Borne Diseases, Upstate Medical University, Syracuse, New York, USA
- Institute for Global Health and Translational Sciences, Upstate Medical University, Syracuse, New York, USA
- Department of Microbiology and Immunology, Upstate Medical University, Syracuse, New York, USA
| | - Benjamin Cull
- Department of Entomology, University of Minnesota, St. Paul, Minnesota, USA
| | - Jonathan D. Oliver
- Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, Minnesota, USA
| | - Timothy J. Kurtti
- Department of Entomology, University of Minnesota, St. Paul, Minnesota, USA
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Rudakova NL, Sabirova AR, Khasanov DI, Danilova IV, Sharipova MR. Regulating Pathways of Bacillus pumilus Adamalysin-like Metalloendopeptidase Expression. Int J Mol Sci 2023; 25:62. [PMID: 38203233 PMCID: PMC10779165 DOI: 10.3390/ijms25010062] [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: 11/11/2023] [Revised: 12/14/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024] Open
Abstract
The minor secreted proteinase of B. pumilus 3-19 MprBp classified as the unique bacillary adamalysin-like enzyme of the metzincin clan. The functional role of this metalloproteinase in the bacilli cells is not clear. Analysis of the regulatory region of the mprBp gene showed the presence of potential binding sites to the transcription regulatory factors Spo0A (sporulation) and DegU (biodegradation). The study of mprBp activity in mutant strains of B. subtilis defective in regulatory proteins of the Spo- and Deg-systems showed that the mprBp gene is partially controlled by the Deg-system of signal transduction and independent from the Spo-system.
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Affiliation(s)
| | | | | | | | - Margarita R. Sharipova
- Institute of Fundamental Medicine, Kazan Federal University, Kremlevskaya St. 18, 420008 Kazan, Russia; (N.L.R.); (D.I.K.); (I.V.D.)
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7
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Aframian N, Eldar A. Abortive infection antiphage defense systems: separating mechanism and phenotype. Trends Microbiol 2023; 31:1003-1012. [PMID: 37268559 DOI: 10.1016/j.tim.2023.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/11/2023] [Accepted: 05/12/2023] [Indexed: 06/04/2023]
Abstract
Bacteria have evolved a wide array of mechanisms that allow them to eliminate phage infection. 'Abortive infection' (abi) systems are an expanding category of such mechanisms, defined as those which induce programmed cell death (or dormancy) upon infection, and thus halt phage propagation within a bacterial population. This definition entails two requirements - a phenotypic observation (cell death upon infection), and a mechanistic determination of its sources (system-induced death). The phenotypic and mechanistic aspects of abi are often implicitly assumed to be tightly linked, and studies regularly tend to establish one and deduce the other. However, recent evidence points to a complicated relationship between the mechanism of defense and the phenotype observed upon infection. We argue that rather than viewing the abi phenotype as an inherent quality of a set of defense systems, it should be more appropriately thought of as an attribute of interactions between specific phages and bacteria under given conditions. Consequently, we also point to potential pitfalls in the prevailing methods for ascertaining the abi phenotype. Overall, we propose an alternative framework for parsing interactions between attacking phages and defending bacteria.
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Affiliation(s)
- Nitzan Aframian
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, 69978, Israel
| | - Avigdor Eldar
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, 69978, Israel.
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8
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Jun JS, Jeong HE, Moon SY, Shin SH, Hong KW. Time-Course Transcriptome Analysis of Bacillus subtilis DB104 during Growth. Microorganisms 2023; 11:1928. [PMID: 37630488 PMCID: PMC10458515 DOI: 10.3390/microorganisms11081928] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/27/2023] Open
Abstract
Bacillus subtilis DB104, an extracellular protease-deficient derivative of B. subtilis 168, is widely used for recombinant protein expression. An understanding of the changes in gene expression during growth is essential for the commercial use of bacterial strains. Transcriptome and proteome analyses are ideal methods to study the genomic response of microorganisms. In this study, transcriptome analysis was performed to monitor changes in the gene expression level of B. subtilis DB104 while growing on a complete medium. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, K-mean cluster analysis, gene ontology (GO) enrichment analysis, and the function of sigma factors were used to divide 2122 differentially expressed genes (DEGs) into 10 clusters and identified gene functions according to expression patterns. The results of KEGG pathway analysis indicated that ABC transporter is down-regulated during exponential growth and metabolic changes occur at the transition point where sporulation starts. At this point, several stress response genes were also turned on. The genes involved in the lipid catabolic process were up-regulated briefly at 15 h as an outcome of the programmed cell death that postpones sporulation. The results suggest that changes in the gene expression of B. subtilis DB104 were dependent on the initiation of sporulation. However, the expression timing of the spore coat gene was only affected by the relevant sigma factor. This study can help to understand gene expression and regulatory mechanisms in B. subtilis species by providing an overall view of transcriptional changes during the growth of B. subtilis DB104.
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Affiliation(s)
| | | | | | | | - Kwang-Won Hong
- Department of Food Science and Biotechnology, College of Life Science and Biotechnology, Dongguk University, Goyang-si 10326, Republic of Korea; (J.-S.J.); (H.-E.J.); (S.-Y.M.); (S.-H.S.)
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9
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Ju J, Liu Y, Liang H, Yang B. The role of pyroptosis in endothelial dysfunction induced by diseases. Front Immunol 2023. [DOI: 10.3389/fimmu.2023.1093985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Most organs in the body rely on blood flow, and vesicular damage is the leading cause of injury in multiple organs. The endothelium, as the barriers of vessels, play a critical role in ensuring vascular homeostasis and angiogenesis. The rapid development of risk factors in endothelial injuries has been seen in the past decade, such as smoking, infectious, and diabetes mellites. Pyroptotic endothelium is an inflammatory mode of governed endothelial cell death that depend on the metabolic disorder and severe infectious such as atherosclerosis, and sepsis-related acute lung injury, respectively. Pyroptotic endothelial cells need GSDMD cleaved into N- and C-terminal by caspase1, and the cytokines are released by a pore constructed by the N-terminal of GSDMD in the membrane of ECs, finally resulting in severe inflammation and pyroptotic cell death. This review will focus on the patho-physiological and pharmacological pathways of pyroptotic endothelial metabolism in diseases. Overall, this review indicates that pyroptosis is a significant risk factor in diseases and a potential drug target in related diseases.
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10
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Ju J, Liu Y, Liang H, Yang B. The role of pyroptosis in endothelial dysfunction induced by diseases. Front Immunol 2023; 13:1093985. [PMID: 36776394 PMCID: PMC9910335 DOI: 10.3389/fimmu.2022.1093985] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 12/19/2022] [Indexed: 01/27/2023] Open
Abstract
Most organs in the body rely on blood flow, and vesicular damage is the leading cause of injury in multiple organs. The endothelium, as the barriers of vessels, play a critical role in ensuring vascular homeostasis and angiogenesis. The rapid development of risk factors in endothelial injuries has been seen in the past decade, such as smoking, infectious, and diabetes mellites. Pyroptotic endothelium is an inflammatory mode of governed endothelial cell death that depend on the metabolic disorder and severe infectious such as atherosclerosis, and sepsis-related acute lung injury, respectively. Pyroptotic endothelial cells need GSDMD cleaved into N- and C-terminal by caspase1, and the cytokines are released by a pore constructed by the N-terminal of GSDMD in the membrane of ECs, finally resulting in severe inflammation and pyroptotic cell death. This review will focus on the patho-physiological and pharmacological pathways of pyroptotic endothelial metabolism in diseases. Overall, this review indicates that pyroptosis is a significant risk factor in diseases and a potential drug target in related diseases.
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Affiliation(s)
- Jin Ju
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, China
| | - Yanyan Liu
- Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and Treatment, Zhuhai People’s Hospital, Zhuhai Hospital Affiliated with Jinan University, Jinan University, Zhuhai, Guangdong, China
| | - Haihai Liang
- Key Laboratory of Cardiovascular Research, State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Ministry of Education, Department of Pharmacology, College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang, China,Research Unit of Noninfectious Chronic Diseases in Frigid Zone (2019RU070), Chinese Academy of Medical Sciences, Harbin, Heilongjiang, China
| | - Baofeng Yang
- Key Laboratory of Cardiovascular Research, State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Ministry of Education, Department of Pharmacology, College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang, China,Research Unit of Noninfectious Chronic Diseases in Frigid Zone (2019RU070), Chinese Academy of Medical Sciences, Harbin, Heilongjiang, China,*Correspondence: Baofeng Yang,
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11
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Aguilera A, Distéfano A, Jauzein C, Correa-Aragunde N, Martinez D, Martin MV, Sueldo DJ. Do photosynthetic cells communicate with each other during cell death? From cyanobacteria to vascular plants. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:7219-7242. [PMID: 36179088 DOI: 10.1093/jxb/erac363] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Abstract
As in metazoans, life in oxygenic photosynthetic organisms relies on the accurate regulation of cell death. During development and in response to the environment, photosynthetic cells activate and execute cell death pathways that culminate in the death of a specific group of cells, a process known as regulated cell death (RCD). RCD control is instrumental, as its misregulation can lead to growth penalties and even the death of the entire organism. Intracellular molecules released during cell demise may act as 'survival' or 'death' signals and control the propagation of cell death to surrounding cells, even in unicellular organisms. This review explores different signals involved in cell-cell communication and systemic signalling in photosynthetic organisms, in particular Ca2+, reactive oxygen species, lipid derivates, nitric oxide, and eATP. We discuss their possible mode-of-action as either 'survival' or 'death' molecules and their potential role in determining cell fate in neighbouring cells. By comparing the knowledge available across the taxonomic spectrum of this coherent phylogenetic group, from cyanobacteria to vascular plants, we aim at contributing to the identification of conserved mechanisms that control cell death propagation in oxygenic photosynthetic organisms.
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Affiliation(s)
- Anabella Aguilera
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, 39231 Kalmar, Sweden
| | - Ayelén Distéfano
- Instituto de Investigaciones Biológicas-CONICET, Universidad Nacional de Mar del Plata, 7600 Mar del Plata, Argentina
| | - Cécile Jauzein
- Ifremer, Centre de Brest, DYNECO-Pelagos, F-29280 Plouzané, France
| | - Natalia Correa-Aragunde
- Instituto de Investigaciones Biológicas-CONICET, Universidad Nacional de Mar del Plata, 7600 Mar del Plata, Argentina
| | - Dana Martinez
- Instituto de Fisiología Vegetal (INFIVE-CONICET), Universidad Nacional de La Plata, 1900 La Plata, Argentina
| | - María Victoria Martin
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), Fundación para Investigaciones Biológicas Aplicadas (FIBA), Universidad Nacional de Mar del Plata,7600 Mar del Plata, Argentina
| | - Daniela J Sueldo
- Norwegian University of Science and Technology, 7491 Trondheim, Norway
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12
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Zhang X, Ma J, Guo Y, Luo Y, Li F, Wang Z. Induced mazEF-mediated programmed cell death contributes to antibiofouling properties of quaternary ammonium compounds modified membranes. WATER RESEARCH 2022; 227:119319. [PMID: 36368087 DOI: 10.1016/j.watres.2022.119319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 10/29/2022] [Accepted: 11/01/2022] [Indexed: 06/16/2023]
Abstract
Functionalized antibiofouling membranes have attracted increasing attention in water and wastewater treatment. Among them, contact-killing antibiofouling membranes deliver a long-lasting effect with no leaching or release, thus providing distinctive advantages. However, the antibiofouling mechanism especially in the vicinity of the membrane surface remains unclear. Herein, we demonstrate that mazEF-mediated programmed cell death (PCD) is critical for the antibiofouling behaviors of quaternary ammonium compounds modified membranes (QM). The viability of wild type Escherichia coli (WT E. coli) upon exposure to QM for 1 h was decreased dramatically (31.5 ± 1.4% of the control). In contrast, the bacterial activity of E. coli with the knockout of mazEF gene (KO E. coli) largely remained (85.8 ± 5.2%). Through addition of quorum sensing factor, i.e., extracellular death factor (EDF), the antibacterial activity was significantly enhanced in a dilute culture, indicating that the density-dependent bacterial communication played an important role in the mazEF-mediated PCD system in biofouling control. Long-term study further showed that QM exhibited a better antibiofouling performance to treat feedwater containing WT E. coli, especially when EDF was dosed. Results of this study suggested that the bacteria on the membrane surface subject to contact killing could modulate the population growth in the vicinity via quorum-sensing mazEF-mediated PCD, paving a way to develop efficient antibiofouling materials based on contact-killing scenarios.
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Affiliation(s)
- Xingran Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; College of Environmental Science and Engineering, Textile pollution controlling Engineering Centre of Ministry of Ecology and Environment, Donghua University, Shanghai 201620, China
| | - Jinxing Ma
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou, 510006, China
| | - Yu Guo
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Yi Luo
- College of Environmental Science and Engineering, Textile pollution controlling Engineering Centre of Ministry of Ecology and Environment, Donghua University, Shanghai 201620, China
| | - Fang Li
- College of Environmental Science and Engineering, Textile pollution controlling Engineering Centre of Ministry of Ecology and Environment, Donghua University, Shanghai 201620, China
| | - Zhiwei Wang
- State Key Laboratory of Pollution Control and Resource Reuse, Shanghai Institute of Pollution Control and Ecological Security, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
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13
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Affiliation(s)
- Alex G. Johnson
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Philip J. Kranzusch
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Parker Institute for Cancer Immunotherapy, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
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14
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Structural and mutational analysis of MazE6-operator DNA complex provide insights into autoregulation of toxin-antitoxin systems. Commun Biol 2022; 5:963. [PMID: 36109664 PMCID: PMC9477884 DOI: 10.1038/s42003-022-03933-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 08/30/2022] [Indexed: 11/29/2022] Open
Abstract
Of the 10 paralogs of MazEF Toxin-Antitoxin system in Mycobacterium tuberculosis, MazEF6 plays an important role in multidrug tolerance, virulence, stress adaptation and Non Replicative Persistant (NRP) state establishment. The solution structures of the DNA binding domain of MazE6 and of its complex with the cognate operator DNA show that transcriptional regulation occurs by binding of MazE6 to an 18 bp operator sequence bearing the TANNNT motif (-10 region). Kinetics and thermodynamics of association, as determined by NMR and ITC, indicate that the nMazE6-DNA complex is of high affinity. Residues in N-terminal region of MazE6 that are key for its homodimerization, DNA binding specificity, and the base pairs in the operator DNA essential for the protein-DNA interaction, have been identified. It provides a basis for design of chemotherapeutic agents that will act via disruption of TA autoregulation, leading to cell death. The dimeric MazE6 antitoxin binds to a specific sequence in its cognate operator DNA for autoregulation, and the key residues for dimerization and DNA binding are identified.
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15
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Jain S, Bhowmick A, Jeong B, Bae T, Ghosh A. Unravelling the physiological roles of mazEF toxin-antitoxin system on clinical MRSA strain by CRISPR RNA-guided cytidine deaminase. J Biomed Sci 2022; 29:28. [PMID: 35524246 PMCID: PMC9077811 DOI: 10.1186/s12929-022-00810-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 04/22/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Curiosity on toxin-antitoxin modules has increased intensely over recent years as it is ubiquitously present in many bacterial genomes, including pathogens like Methicillin-resistant Staphylococcus aureus (MRSA). Several cellular functions of TA systems have been proposed however, their exact role in cellular physiology remains unresolved. METHODS This study aims to find out the impact of the mazEF toxin-antitoxin module on biofilm formation, pathogenesis, and antibiotic resistance in an isolated clinical ST239 MRSA strain, by constructing mazE and mazF mutants using CRISPR-cas9 base-editing plasmid (pnCasSA-BEC). Transcriptome analysis (RNA-seq) was performed for the mazE antitoxin mutant in order to identify the differentially regulated genes. The biofilm formation was also assessed for the mutant strains. Antibiogram profiling was carried out for both the generated mutants followed by murine experiment to determine the pathogenicity of the constructed strains. RESULTS For the first time our work showed, that MazF promotes cidA mediated cell death and lysis for biofilm formation without playing any significant role in host virulence as suggested by the murine experiment. Interestingly, the susceptibility to oxacillin, daptomycin and vancomycin was reduced significantly by the activated MazF toxin in the mazE mutant strain. CONCLUSIONS Our study reveals that activated MazF toxin leads to resistance to antibiotics like oxacillin, daptomycin and vancomycin. Therefore, in the future, any potential antibacterial drug can be designed to target MazF toxin against the problematic multi-drug resistant bug.
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Affiliation(s)
- Sonia Jain
- Infectious Disease and Immunology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, 700032, India.
| | - Arghya Bhowmick
- Department of Biochemistry, Bose Institute, EN Block, Sector-V, Kolkata, 700091, India
| | - Bohyun Jeong
- Department of Microbiology, Kosin University College of Medicine, Busan, 49267, South Korea
| | - Taeok Bae
- Department of Microbiology and Immunology, Indiana University, School of Medicine-Northwest, Gary, IN, 46408-1197, USA
| | - Abhrajyoti Ghosh
- Department of Biochemistry, Bose Institute, EN Block, Sector-V, Kolkata, 700091, India.
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16
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Yadav M, Pundir S, Kumari R, Kumar A, Venugopal SJ, Panigrahy R, Tak V, Chunchanur SK, Gautam H, Kapil A, Das B, Sood S, Salve HR, Malhotra S, Kant S, Hari P, Chaudhuri S, Mohapatra S. Virulence gene mutations as a differentiator of clinical phenotypes: insights from community-acquired uropathogenic Escherichia coli. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35380532 DOI: 10.1099/mic.0.001161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Uropathogenic Escherichia coli (UPEC) remains an important cause of urinary tract infection during pregnancy. Multiple molecular virulence determinants and antibiotic resistant genes facilitate its pathogenesis and virulence phenotype. Hence it is hypothesized that there will be considerable variation in genes among the isolates from symptomatic as well as asymptomatic bacteriuria (ABU) during pregnancy. The aim of this study was to decipher the genetic variation among the two phenotypes. Six different UPEC isolates collected from urine specimens of consecutive pregnant females (five, symptomatic bacteriuria and one, ABU) were tested for their growth kinetics, and biofilm formation. A total of 87 virulence determinants and 56 antibiotic resistance genes were investigated using whole-genome sequencing, to identify putative drives of virulence phenotype. In this analysis, we identified eight different types of fully functional toxin antitoxin (TA) systems [HipAB, YefM-YoeB, YeeU-YeeV (CbtA), YhaV-PrlF, ChpBS, HigAB, YgiUT and HicAB] in the isolates from symptomatic bacteriuria; whereas partially functional TA system with mutations were observed in the asymptomatic one. Isolates of both the groups showed equivalent growth characteristics and biofilm-formation ability. Genes for an iron transport system (Efe UOB system, Fhu system except FhuA) were observed functional among all symptomatic and asymptomatic isolates, however functional mutations were observed in the latter group. Gene YidE was observed predominantly associated with the biofilm formation along with few other genes (BssR, BssS, YjgK, etc.). This study outlines putative critical relevance of specific variations in the genes for the TA system, biofilm formation, cell adhesion and colonization among UPEC isolates from symptomatic and asymptomatic bacteriuria among pregnant women. Further functional genomic study in the same cohort is warranted to establish the pathogenic role of these genes.
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Affiliation(s)
- Manisha Yadav
- Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Swati Pundir
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - Rajesh Kumari
- Department of Obstetrics and Gynaecology, All India Institute of Medical Science, New Delhi, India
| | - Arvind Kumar
- Department of Medicine, All India Institute of Medical Science, New Delhi, India
| | - Shwetha J Venugopal
- Department of Microbiology, Bangalore Medical College and Research Institute, Bangalore, India
| | - Rajashree Panigrahy
- Department of Microbiology, Institute of Medical Sciences and SUM Hospital, Bhubaneswar, India
| | - Vibhor Tak
- Department of Microbiology, All India Institute of Medical Science, Jodhpur, India
| | - Sneha K Chunchanur
- Department of Microbiology, Bangalore Medical College and Research Institute, Bangalore, India
| | - Hitender Gautam
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - Arti Kapil
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - Bimal Das
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - Seema Sood
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - Harshal Ramesh Salve
- Centre for Community Medicine, All India Institute of Medical Science, New Delhi, India
| | - Sumit Malhotra
- Centre for Community Medicine, All India Institute of Medical Science, New Delhi, India
| | - Shashi Kant
- Centre for Community Medicine, All India Institute of Medical Science, New Delhi, India
| | - Pankaj Hari
- Department of Pediatrics, All India Institute of Medical Science, New Delhi, India
| | - Susmita Chaudhuri
- Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Sarita Mohapatra
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
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17
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Vasilchenko NG, Prazdnova EV, Lewitin E. Epigenetic Mechanisms of Gene Expression Regulation in Bacteria of the Genus Bacillus. RUSS J GENET+ 2022. [DOI: 10.1134/s1022795422010124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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18
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Pareek V, Gupta R, Devineau S, Sivasankaran SK, Bhargava A, Khan MA, Srikumar S, Fanning S, Panwar J. Does Silver in Different Forms Affect Bacterial Susceptibility and Resistance? A Mechanistic Perspective. ACS APPLIED BIO MATERIALS 2022; 5:801-817. [PMID: 35073697 DOI: 10.1021/acsabm.1c01179] [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: 01/13/2023]
Abstract
The exceptional increase in antibiotic resistance in past decades motivated the scientific community to use silver as a potential antibacterial agent. However, due to its unknown antibacterial mechanism and the pattern of bacterial resistance to silver species, it has not been revolutionized in the health sector. This study deciphers mechanistic aspects of silver species, i.e., ions and lysozyme-coated silver nanoparticles (L-Ag NPs), against E. coli K12 through RNA sequencing analysis. The obtained results support the reservoir nature of nanoparticles for the controlled release of silver ions into bacteria. This study differentiates between the antibacterial mechanism of silver species by discussing the pathway of their entry in bacteria, sequence of events inside cells, and response of bacteria to overcome silver stress. Controlled release of ions from L-Ag NPs not only reduces bacterial growth but also reduces the likelihood of resistance development. Conversely, direct exposure of silver ions, leads to rapid activation of the bacterial defense system leading to development of resistance against silver ions, like the well-known antibiotic resistance problem. These findings provide valuable insight on the mechanism of silver resistance and antibacterial strategies deployed by E. coli K12, which could be a potential target for the generation of aim-based and effective nanoantibiotics.
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Affiliation(s)
- Vikram Pareek
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani 333031, India.,School of Public Health, Physiotherapy and Sports Science, Centre for Food Safety, Science Centre South, University College Dublin, Dublin 4, Ireland
| | - Rinki Gupta
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani 333031, India
| | | | | | - Arpit Bhargava
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani 333031, India
| | - Mohd Azeem Khan
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani 333031, India
| | - Shabrinath Srikumar
- Department of Food, Nutrition and Health, College of Food and Agriculture, UAE University, Al Ain 15551, UAE
| | - Séamus Fanning
- School of Public Health, Physiotherapy and Sports Science, Centre for Food Safety, Science Centre South, University College Dublin, Dublin 4, Ireland.,Institute for Global Food Security, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - Jitendra Panwar
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani 333031, India
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19
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Abstract
Toxin-antitoxin systems are widespread in bacterial genomes. They are usually composed of two elements: a toxin that inhibits an essential cellular process and an antitoxin that counteracts its cognate toxin. In the past decade, a number of new toxin-antitoxin systems have been described, bringing new growth inhibition mechanisms to light as well as novel modes of antitoxicity. However, recent advances in the field profoundly questioned the role of these systems in bacterial physiology, stress response and antimicrobial persistence. This shifted the paradigm of the functions of toxin-antitoxin systems to roles related to interactions between hosts and their mobile genetic elements, such as viral defence or plasmid stability. In this Review, we summarize the recent progress in understanding the biology and evolution of these small genetic elements, and discuss how genomic conflicts could shape the diversification of toxin-antitoxin systems.
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20
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Kim DH, Kang SM, Baek SM, Yoon HJ, Jang DM, Kim H, Lee S, Lee BJ. OUP accepted manuscript. Nucleic Acids Res 2022; 50:2319-2333. [PMID: 35141752 PMCID: PMC8887465 DOI: 10.1093/nar/gkab1288] [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: 06/09/2021] [Revised: 12/15/2021] [Accepted: 12/17/2021] [Indexed: 11/24/2022] Open
Abstract
Staphylococcus aureus is a notorious and globally distributed pathogenic bacterium. New strategies to develop novel antibiotics based on intrinsic bacterial toxin–antitoxin (TA) systems have been recently reported. Because TA systems are present only in bacteria and not in humans, these distinctive systems are attractive targets for developing antibiotics with new modes of action. S. aureus PemIK is a type II TA system, comprising the toxin protein PemK and the labile antitoxin protein PemI. Here, we determined the crystal structures of both PemK and the PemIK complex, in which PemK is neutralized by PemI. Our biochemical approaches, including fluorescence quenching and polarization assays, identified Glu20, Arg25, Thr48, Thr49, and Arg84 of PemK as being important for RNase function. Our study indicates that the active site and RNA-binding residues of PemK are covered by PemI, leading to unique conformational changes in PemK accompanied by repositioning of the loop between β1 and β2. These changes can interfere with RNA binding by PemK. Overall, PemK adopts particular open and closed forms for precise neutralization by PemI. This structural and functional information on PemIK will contribute to the discovery and development of novel antibiotics in the form of peptides or small molecules inhibiting direct binding between PemI and PemK.
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Affiliation(s)
| | | | - Sung-Min Baek
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Hye-Jin Yoon
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Dong Man Jang
- Research Institute, National Cancer Center, Goyang, Gyeonggi 10408, Republic of Korea
| | - Hyoun Sook Kim
- Research Institute, National Cancer Center, Goyang, Gyeonggi 10408, Republic of Korea
| | - Sang Jae Lee
- Correspondence may also be addressed to Sang Jae Lee. Tel: +82 54 279 1490;
| | - Bong-Jin Lee
- To whom correspondence should be addressed. Tel: +82 2 880 7869;
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21
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Bright R, Fernandes D, Wood J, Palms D, Burzava A, Ninan N, Brown T, Barker D, Vasilev K. Long-term antibacterial properties of a nanostructured titanium alloy surface: An in vitro study. Mater Today Bio 2021; 13:100176. [PMID: 34938990 DOI: 10.1016/j.mtbio.2021.100176] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/18/2021] [Accepted: 12/01/2021] [Indexed: 12/31/2022] Open
Abstract
The demand for joint replacement and other orthopedic surgeries involving titanium implants is continuously increasing; however, 1%-2% of surgeries result in costly and devastating implant associated infections (IAIs). Pseudomonas aeruginosa and Staphylococcus aureus are two common pathogens known to colonise implants, leading to serious complications. Bioinspired surfaces with spike-like nanotopography have previously been shown to kill bacteria upon contact; however, the longer-term potential of such surfaces to prevent or delay biofilm formation is unclear. Hence, we monitored biofilm formation on control and nanostructured titanium disc surfaces over 21 days following inoculation with Pseudomonas aeruginosa and Staphylococcus aureus. We found a consistent 2-log or higher reduction in live bacteria throughout the time course for both bacteria. The biovolume on nanostructured discs was also significantly lower than control discs at all time points for both bacteria. Analysis of the biovolume revealed that for the nanostructured surface, bacteria was killed not just on the surface, but at locations above the surface. Interestingly, pockets of bacterial regrowth on top of the biomass occurred in both bacterial species, however this was more pronounced for S. aureus cultures after 21 days. We found that the nanostructured surface showed antibacterial properties throughout this longitudinal study. To our knowledge this is the first in vitro study to show reduction in the viability of bacterial colonisation on a nanostructured surface over a clinically relevant time frame, providing potential to reduce the likelihood of implant associated infections.
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Affiliation(s)
- Richard Bright
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide, 5095, South Australia, Australia
| | - Daniel Fernandes
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide, 5095, South Australia, Australia
| | - Jonathan Wood
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide, 5095, South Australia, Australia
| | - Dennis Palms
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide, 5095, South Australia, Australia
| | - Anouck Burzava
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide, 5095, South Australia, Australia
| | - Neethu Ninan
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide, 5095, South Australia, Australia
| | - Toby Brown
- Corin Australia, Pymble, NSW 2073, Australia
| | - Dan Barker
- Corin Australia, Pymble, NSW 2073, Australia
| | - Krasimir Vasilev
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide, 5095, South Australia, Australia
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22
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Rodrigues AMM, Gardner A. Reproductive value and the evolution of altruism. Trends Ecol Evol 2021; 37:346-358. [PMID: 34949484 DOI: 10.1016/j.tree.2021.11.007] [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: 09/01/2021] [Revised: 11/05/2021] [Accepted: 11/09/2021] [Indexed: 11/26/2022]
Abstract
Altruism is favored by natural selection provided that it delivers sufficient benefits to relatives. An altruist's valuation of her relatives depends upon the extent to which they carry copies of her genes - relatedness - and also on the extent to which they are able to transmit their own genes to future generations - reproductive value. However, although relatedness has received a great deal of attention with regard to altruism, reproductive value has been surprisingly neglected. We review how reproductive value modulates patterns of altruism in relation to individual differences in age, sex, and general condition, and discuss how social partners may manipulate each other's reproductive value to incentivize altruism. This topic presents opportunities for tight interplay between theoretical and empirical research.
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Affiliation(s)
- António M M Rodrigues
- Department of Ecology and Evolutionary Biology, Yale University, 165 Prospect Street, New Haven, CT 06511, USA.
| | - Andy Gardner
- School of Biology, University of St Andrews, Greenside Place, St Andrews KY16 9TH, UK
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23
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Heffern EFW, Huelskamp H, Bahar S, Inglis RF. Phase transitions in biology: from bird flocks to population dynamics. Proc Biol Sci 2021; 288:20211111. [PMID: 34666526 PMCID: PMC8527202 DOI: 10.1098/rspb.2021.1111] [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: 05/13/2021] [Accepted: 09/27/2021] [Indexed: 11/12/2022] Open
Abstract
Phase transitions are an important and extensively studied concept in physics. The insights derived from understanding phase transitions in physics have recently and successfully been applied to a number of different phenomena in biological systems. Here, we provide a brief review of phase transitions and their role in explaining biological processes ranging from collective behaviour in animal flocks to neuronal firing. We also highlight a new and exciting area where phase transition theory is particularly applicable: population collapse and extinction. We discuss how phase transition theory can give insight into a range of extinction events such as population decline due to climate change or microbial responses to stressors such as antibiotic treatment.
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Affiliation(s)
| | - Holly Huelskamp
- Department of Biology, University of Missouri at St Louis, St Louis, MO, USA
| | - Sonya Bahar
- Department of Physics and Astronomy, University of Missouri at St Louis, St Louis, MO, USA
| | - R. Fredrik Inglis
- Department of Biology, University of Missouri at St Louis, St Louis, MO, USA
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24
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Kim H, Lee DG. Contribution of SOS genes to H 2O 2-induced apoptosis-like death in Escherichia coli. Curr Genet 2021; 67:969-980. [PMID: 34435216 DOI: 10.1007/s00294-021-01204-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/14/2021] [Accepted: 07/16/2021] [Indexed: 01/07/2023]
Abstract
Hydrogen peroxide (H2O2) is a debriding agent that damages the microbial structure and function by generating various reactive oxygen species (ROS). H2O2-produced hydroxyl radical (OH∙) also exerts oxidative stress on microorganisms. The spread of antibiotic-resistance in bacteria is a serious issue worldwide, and greater efforts are needed to identify and characterize novel antibacterial mechanisms to develop new treatment strategies. Therefore, this study aimed to clarify the relationship between H2O2 and Escherichia coli and to elucidate a novel antibacterial mechanism(s) of H2O2. Following H2O2 exposure, increased levels of 8-hydroxydeoxyguanosine and malondialdehyde indicated that H2O2 accelerates oxidation of bacterial DNA and lipids in E. coli. As oxidative damage worsened, the SOS response was triggered. Cell division arrest and resulting filamentous cells were identified in cells, indicating that LexA was involved in DNA replication. It was also verified that RecA, a representative SOS gene, helps self-cleavage of LexA and acts as a bacterial caspase-like protein. Our findings also showed that dinF is essential to preserve E. coli from H2O2-induced ROS, and furthermore, demonstrated that H2O2-induced SOS response and SOS genes participate differently in guarding E. coli from oxidative stress. As an extreme SOS response is considered apoptosis-like death (ALD) in bacteria, additional experiments were performed to examine the characteristics of ALD. DNA fragmentation and membrane depolarization appeared in H2O2-treated cells, suggesting that H2O2 causes ALD in E. coli. In conclusion, our investigations revealed that ALD is a novel antibacterial mode of action(s) of H2O2 with important contributions from SOS genes.
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Affiliation(s)
- Heesu Kim
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Korea
| | - Dong Gun Lee
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Korea.
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25
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Jin C, Kang SM, Kim DH, Lee BJ. Structural and functional analysis of the Klebsiella pneumoniae MazEF toxin-antitoxin system. IUCRJ 2021; 8:362-371. [PMID: 33953923 PMCID: PMC8086154 DOI: 10.1107/s2052252521000452] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 01/13/2021] [Indexed: 06/12/2023]
Abstract
Bacterial toxin-antitoxin (TA) systems correlate strongly with physiological processes in bacteria, such as growth arrest, survival and apoptosis. Here, the first crystal structure of a type II TA complex structure of Klebsiella pneumoniae at 2.3 Å resolution is presented. The K. pneumoniae MazEF complex consists of two MazEs and four MazFs in a heterohexameric assembly. It was estimated that MazEF forms a dodecamer with two heterohexameric MazEF complexes in solution, and a truncated complex exists in heterohexameric form. The MazE antitoxin interacts with the MazF toxin via two binding modes, namely, hydro-phobic and hydro-philic interactions. Compared with structural homologs, K. pneumoniae MazF shows distinct features in loops β1-β2, β3-β4 and β4-β5. It can be inferred that these three loops have the potential to represent the unique characteristics of MazF, especially various substrate recognition sites. In addition, K. pneumoniae MazF shows ribonuclease activity and the catalytic core of MazF lies in an RNA-binding pocket. Mutation experiments and cell-growth assays confirm Arg28 and Thr51 as critical residues for MazF ribonuclease activity. The findings shown here may contribute to the understanding of the bacterial MazEF TA system and the exploration of antimicrobial candidates to treat drug-resistant K. pneumoniae.
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Affiliation(s)
- Chenglong Jin
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Sung-Min Kang
- College of Pharmacy, Duksung Women’s University, Seoul, 01369, Republic of Korea
| | - Do-Hee Kim
- College of Pharmacy, Jeju National University, Jeju, 63243, Republic of Korea
- Interdisciplinary Graduate Program in Advanced Convergence Technology & Science, Jeju National University, Jeju, 63243, Republic of Korea
| | - Bong-Jin Lee
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul, 08826, Republic of Korea
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26
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Lema A S, Klemenčič M, Völlmy F, Altelaar M, Funk C. The Role of Pseudo-Orthocaspase (SyOC) of Synechocystis sp. PCC 6803 in Attenuating the Effect of Oxidative Stress. Front Microbiol 2021; 12:634366. [PMID: 33613507 PMCID: PMC7889975 DOI: 10.3389/fmicb.2021.634366] [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: 11/27/2020] [Accepted: 01/11/2021] [Indexed: 11/13/2022] Open
Abstract
Caspases are proteases, best known for their involvement in the execution of apoptosis-a subtype of programmed cell death, which occurs only in animals. These proteases are composed of two structural building blocks: a proteolytically active p20 domain and a regulatory p10 domain. Although structural homologs appear in representatives of all other organisms, their functional homology, i.e., cell death depending on their proteolytical activity, is still much disputed. Additionally, pseudo-caspases and pseudo-metacaspases, in which the catalytic histidine-cysteine dyad is substituted with non-proteolytic amino acid residues, were shown to be involved in cell death programs. Here, we present the involvement of a pseudo-orthocaspase (SyOC), a prokaryotic caspase-homolog lacking the p10 domain, in oxidative stress in the model cyanobacterium Synechocystis sp. PCC 6803. To study the in vivo impact of this pseudo-protease during oxidative stress its gene expression during exposure to H2O2 was monitored by RT-qPCR. Furthermore, a knock-out mutant lacking the pseudo-orthocaspase gene was designed, and its survival and growth rates were compared to wild type cells as well as its proteome. Deletion of SyOC led to cells with a higher tolerance toward oxidative stress, suggesting that this protein may be involved in a pro-death pathway.
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Affiliation(s)
- Saul Lema A
- Department of Chemistry, Umeå University, Umeå, Sweden
| | | | - Franziska Völlmy
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, Netherlands.,Netherlands Proteomics Centre, Utrecht, Netherlands
| | - Maarten Altelaar
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, Netherlands.,Netherlands Proteomics Centre, Utrecht, Netherlands
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Dai J, Chen Z, Hou J, Wang Y, Guo M, Cao J, Wang L, Xu H, Tian B, Zhao Y. MazEF Toxin-Antitoxin System-Mediated DNA Damage Stress Response in Deinococcus radiodurans. Front Genet 2021; 12:632423. [PMID: 33679894 PMCID: PMC7933679 DOI: 10.3389/fgene.2021.632423] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 01/12/2021] [Indexed: 01/01/2023] Open
Abstract
Deinococcus radiodurans shows marked resistance to various types of DNA-damaging agents, including mitomycin C (MMC). A type II toxin-antitoxin (TA) system that responds to DNA damage stress was identified in D. radiodurans, comprising the toxin MazF-dr and the antitoxin MazE-dr. The cleavage specificity of MazF-dr, an endoribonuclease, was previously characterized. Here, we further investigated the regulatory role of the MazEF system in the response to DNA damage stress in D. radiodurans. The crystal structure of D. radiodurans MazF (MazF-dr) was determined at a resolution of 1.3 Å and is the first structure of the toxin of the TA system of D. radiodurans. MazF-dr forms a dimer mediated by the presence of interlocked loops. Transcriptional analysis revealed 650 downregulated genes in the wild-type (WT) strain, but not in the mazEF mutant strain, which are potentially regulated by MazEF-dr in response to MMC treatment. Some of these genes are involved in membrane trafficking and metal ion transportation. Subsequently, compared with the WT strain, the mazEF mutant strain exhibited much lower MMC-induced intracellular iron concentrations, reactive oxygen species (ROS), and protein carbonylation levels. These results provide evidence that MazEF-mediated cell death in D. radiodurans might be caused by an increase in ROS accumulation upon DNA damage stress.
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Affiliation(s)
- Jingli Dai
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Zijing Chen
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Jinfeng Hou
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Yudong Wang
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Miao Guo
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Jiajia Cao
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Liangyan Wang
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Hong Xu
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Bing Tian
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
| | - Ye Zhao
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.,MOE Key Laboratory of Biosystems Homeostasis and Protection, Zhejiang University, Hangzhou, China
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Biofilms as Promoters of Bacterial Antibiotic Resistance and Tolerance. Antibiotics (Basel) 2020; 10:antibiotics10010003. [PMID: 33374551 PMCID: PMC7822488 DOI: 10.3390/antibiotics10010003] [Citation(s) in RCA: 184] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/15/2020] [Accepted: 12/19/2020] [Indexed: 12/12/2022] Open
Abstract
Multidrug resistant bacteria are a global threat for human and animal health. However, they are only part of the problem of antibiotic failure. Another bacterial strategy that contributes to their capacity to withstand antimicrobials is the formation of biofilms. Biofilms are associations of microorganisms embedded a self-produced extracellular matrix. They create particular environments that confer bacterial tolerance and resistance to antibiotics by different mechanisms that depend upon factors such as biofilm composition, architecture, the stage of biofilm development, and growth conditions. The biofilm structure hinders the penetration of antibiotics and may prevent the accumulation of bactericidal concentrations throughout the entire biofilm. In addition, gradients of dispersion of nutrients and oxygen within the biofilm generate different metabolic states of individual cells and favor the development of antibiotic tolerance and bacterial persistence. Furthermore, antimicrobial resistance may develop within biofilms through a variety of mechanisms. The expression of efflux pumps may be induced in various parts of the biofilm and the mutation frequency is induced, while the presence of extracellular DNA and the close contact between cells favor horizontal gene transfer. A deep understanding of the mechanisms by which biofilms cause tolerance/resistance to antibiotics helps to develop novel strategies to fight these infections.
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Drlica K, Zhao X. Bacterial death from treatment with fluoroquinolones and other lethal stressors. Expert Rev Anti Infect Ther 2020; 19:601-618. [PMID: 33081547 DOI: 10.1080/14787210.2021.1840353] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Lethal stressors, including antimicrobials, kill bacteria in part through a metabolic response proposed to involve reactive oxygen species (ROS). The quinolone anti-bacterials have served as key experimental tools in developing this idea. AREAS COVERED Bacteriostatic and bactericidal action of quinolones are distinguished, with emphasis on the contribution of chromosome fragmentation and ROS accumulation to bacterial death. Action of non-quinolone antibacterials and non-antimicrobial stressors is described to provide a general framework for understanding stress-mediated, bacterial death. EXPERT OPINION Quinolones trap topoisomerases on DNA in reversible complexes that block DNA replication and bacterial growth. At elevated drug concentrations, DNA ends are released from topoisomerase-mediated constraint, leading to the idea that death arises from chromosome fragmentation. However, DNA ends also stimulate repair, which is energetically expensive. An incompletely understood metabolic shift occurs, and ROS accumulate. Even after quinolone removal, ROS continue to amplify, generating secondary and tertiary damage that overwhelms repair and causes death. Repair may also contribute to death directly via DNA breaks arising from incomplete base-excision repair of ROS-oxidized nucleotides. Remarkably, perturbations that interfere with ROS accumulation confer tolerance to many diverse lethal agents.
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Affiliation(s)
| | - Xilin Zhao
- Rutgers University, Newark, NJ, USA.,State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, South Xiang-An Road, Xiang-An District, Xiamen, Fujian Province, China
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30
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de Jong SI, van den Broek MA, Merkel AY, de la Torre Cortes P, Kalamorz F, Cook GM, van Loosdrecht MCM, McMillan DGG. Genomic analysis of Caldalkalibacillus thermarum TA2.A1 reveals aerobic alkaliphilic metabolism and evolutionary hallmarks linking alkaliphilic bacteria and plant life. Extremophiles 2020; 24:923-935. [PMID: 33030592 PMCID: PMC7561548 DOI: 10.1007/s00792-020-01205-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 09/23/2020] [Indexed: 12/28/2022]
Abstract
The aerobic thermoalkaliphile Caldalkalibacillus thermarum strain TA2.A1 is a member of a separate order of alkaliphilic bacteria closely related to the Bacillales order. Efforts to relate the genomic information of this evolutionary ancient organism to environmental adaptation have been thwarted by the inability to construct a complete genome. The existing draft genome is highly fragmented due to repetitive regions, and gaps between and over repetitive regions were unbridgeable. To address this, Oxford Nanopore Technology's MinION allowed us to span these repeats through long reads, with over 6000-fold coverage. This resulted in a single 3.34 Mb circular chromosome. The profile of transporters and central metabolism gives insight into why the organism prefers glutamate over sucrose as carbon source. We propose that the deamination of glutamate allows alkalization of the immediate environment, an excellent example of how an extremophile modulates environmental conditions to suit its own requirements. Curiously, plant-like hallmark electron transfer enzymes and transporters are found throughout the genome, such as a cytochrome b6c1 complex and a CO2-concentrating transporter. In addition, multiple self-splicing group II intron-encoded proteins closely aligning to those of a telomerase reverse transcriptase in Arabidopsis thaliana were revealed. Collectively, these features suggest an evolutionary relationship to plant life.
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Affiliation(s)
- Samuel I de Jong
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | | | - Alexander Y Merkel
- Winogradsky Institute of Microbiology, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | | | - Falk Kalamorz
- The New Zealand Institute for Plant and Food Research, Lincoln, New Zealand
| | - Gregory M Cook
- Department of Microbiology and Immunology, The University of Otago, Dunedin, New Zealand
| | | | - Duncan G G McMillan
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.
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MazEF-rifampicin interaction suggests a mechanism for rifampicin induced inhibition of persisters. BMC Mol Cell Biol 2020; 21:73. [PMID: 33109090 PMCID: PMC7590665 DOI: 10.1186/s12860-020-00316-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/11/2020] [Indexed: 12/15/2022] Open
Abstract
Background Persistence is a natural phenomenon whereby a subset of a population of isogenic bacteria either grow slow or become dormant conferring them with the ability to withstand various stresses including antibiotics. In a clinical setting bacterial persistence often leads to the recalcitrance of various infections increasing the treatment time and cost. Additionally, some studies also indicate that persistence can also pave way for the emergence of resistant strains. In a laboratory setting this persistent phenotype is enriched in nutritionally deprived environments. Consequently, in a batch culture the late stationary phase is enriched with persistent bacteria. The mechanism of persister cell formation and its regulation is not well understood. Toxin-antitoxin (TA) systems have been implicated to be responsible for bacterial persistence and rifampicin is used to treat highly persistent bacterial strains. The current study tries to explore a possible interaction between rifampicin and the MazEF TA system that furthers the former’s success rate in treating persistent bacteria. Results In the current study we found that the population of bacteria in the death phase of a batch culture consists of metabolically inactive live cells resembling persisters, which showed higher membrane depolarization as compared to the log phase bacteria. We also observed an increase in the expression of the MazEF TA modules in this phase. Since rifampicin is used to kill the persisters, we assessed the interaction of rifampicin with MazEF complex. We showed that rifampicin moderately interacts with MazEF complex with 1:1 stoichiometry. Conclusion Our study suggests that the interaction of rifampicin with MazEF complex might play an important role in inhibition of persisters. Supplementary information The online version contains supplementary material available at 10.1186/s12860-020-00316-8.
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Pinto L, Torres C, Gil C, Santos HM, Capelo JL, Borges V, Gomes JP, Silva C, Vieira L, Poeta P, Igrejas G. Multiomics Substrates of Resistance to Emerging Pathogens? Transcriptome and Proteome Profile of a Vancomycin-Resistant Enterococcus faecalis Clinical Strain. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2020; 24:81-95. [PMID: 32073998 DOI: 10.1089/omi.2019.0164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Antibiotic resistance and hospital acquired infections are on the rise worldwide. Vancomycin-resistant enterococci have been reported in clinical settings in recent decades. In this multiomics study, we provide comprehensive proteomic and transcriptomic analyses of a vancomycin-resistant Enterococcus faecalis clinical isolate from a patient with a urinary tract infection. The previous genotypic profile of the strain C2620 indicated the presence of antibiotic resistance genes characteristic of the vanB cluster. To further investigate the transcriptome of this pathogenic strain, we used whole genome sequencing and RNA-sequencing to detect and quantify the genes expressed. In parallel, we used two-dimensional gel electrophoresis followed by MALDI-TOF/MS (Matrix-assisted laser desorption/ionization-Time-of-flight/Mass spectrometry) to identify the proteins in the proteome. We studied the membrane and cytoplasm subproteomes separately. From a total of 207 analysis spots, we identified 118 proteins. The protein list was compared to the results obtained from the full transcriptome assay. Several genes and proteins related to stress and cellular response were identified, as well as some linked to antibiotic and drug responses, which is consistent with the known state of multiresistance. Even though the correlation between transcriptome and proteome data is not yet fully understood, the use of multiomics approaches has proven to be increasingly relevant to achieve deeper insights into the survival ability of pathogenic bacteria found in health care facilities.
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Affiliation(s)
- Luís Pinto
- Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.,Functional Genomics and Proteomics Unit, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.,Veterinary Science Department, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
| | - Carmen Torres
- Área de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain
| | - Concha Gil
- Departamento de Microbiologia II, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Hugo M Santos
- LAQV-REQUIMTE, Faculty of Science and Technology, Nova University of Lisbon, Lisbon, Portugal
| | - José Luís Capelo
- LAQV-REQUIMTE, Faculty of Science and Technology, Nova University of Lisbon, Lisbon, Portugal
| | - Vítor Borges
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - João Paulo Gomes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - Catarina Silva
- Innovation and Technology Unit, Department of Human Genetics, National Institute of Health, Lisbon, Portugal
| | - Luís Vieira
- Innovation and Technology Unit, Department of Human Genetics, National Institute of Health, Lisbon, Portugal
| | - Patrícia Poeta
- Veterinary Science Department, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.,LAQV-REQUIMTE, Faculty of Science and Technology, Nova University of Lisbon, Lisbon, Portugal
| | - Gilberto Igrejas
- Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.,Functional Genomics and Proteomics Unit, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.,LAQV-REQUIMTE, Faculty of Science and Technology, Nova University of Lisbon, Lisbon, Portugal
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33
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Regulated Cell Death in Pulpitis. J Endod 2020; 46:1403-1413. [DOI: 10.1016/j.joen.2020.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 06/25/2020] [Accepted: 07/04/2020] [Indexed: 12/27/2022]
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Chen G, Gao C, Yan Y, Wang T, Luo C, Zhang M, Chen X, Tao L. Inhibiting ER Stress Weakens Neuronal Pyroptosis in a Mouse Acute Hemorrhagic Stroke Model. Mol Neurobiol 2020; 57:5324-5335. [PMID: 32880859 DOI: 10.1007/s12035-020-02097-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 08/25/2020] [Indexed: 01/17/2023]
Abstract
Intracerebral hemorrhage (ICH) is a form of stroke, characterized by high morbidity and mortality and currently lacks specific therapy. ICH leads to endoplasmic reticulum (ER) stress, which can induce neurological impairment through crosstalk with programmed cell death (PCD). Pyroptosis, a newly discovered form of PCD, has received attention because of its close relationship with some certain diseases, such as traumatic brain injury and ischemic and hemorrhagic stroke. However, the relationship between ER stress and pyroptosis in ICH remains unclear. In this study, we investigated the role of ER stress in evoking neuronal pyroptosis and related mechanisms in a mouse ICH model. We used tauroursodeoxycholic acid (TUDCA) to inhibit ER stress and observed that TUDCA reduces neuronal pyroptosis and has a neuroprotective role. We explored the potential mechanisms underlying the regulation of neuronal pyroptosis by ER stress through testing the expression of interleukin-13 (IL-13). We found that ER stress inhibition alleviates neuronal pyroptosis through decreasing the expression of IL-13 after ICH. In summary, this study revealed that IL-13 is involved in ER stress-induced neuronal pyroptosis after ICH, pointing to IL-13 as a novel therapeutic target for ICH treatment.
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Affiliation(s)
- Guang Chen
- Department of Forensic Medicine, Medical School of Soochow University, 178 East Ganjiang Road, Suzhou, 215213, China
| | - Cheng Gao
- Department of Forensic Medicine, Medical School of Soochow University, 178 East Ganjiang Road, Suzhou, 215213, China
| | - Ya'nan Yan
- Department of Forensic Medicine, Medical School of Soochow University, 178 East Ganjiang Road, Suzhou, 215213, China
| | - Tao Wang
- Department of Forensic Medicine, Medical School of Soochow University, 178 East Ganjiang Road, Suzhou, 215213, China
| | - Chengliang Luo
- Department of Forensic Medicine, Medical School of Soochow University, 178 East Ganjiang Road, Suzhou, 215213, China
| | - Mingyang Zhang
- Department of Forensic Medicine, Medical School of Soochow University, 178 East Ganjiang Road, Suzhou, 215213, China
| | - Xiping Chen
- Department of Forensic Medicine, Medical School of Soochow University, 178 East Ganjiang Road, Suzhou, 215213, China.
| | - Luyang Tao
- Department of Forensic Medicine, Medical School of Soochow University, 178 East Ganjiang Road, Suzhou, 215213, China.
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Bhattacharjee S, Mishra AK. The tale of caspase homologues and their evolutionary outlook: deciphering programmed cell death in cyanobacteria. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:4639-4657. [PMID: 32369588 PMCID: PMC7475262 DOI: 10.1093/jxb/eraa213] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 04/28/2020] [Indexed: 06/11/2023]
Abstract
Programmed cell death (PCD), a genetically orchestrated mechanism of cellular demise, is paradoxically required to support life. As in lower eukaryotes and bacteria, PCD in cyanobacteria is poorly appreciated, despite recent biochemical and molecular evidence that supports its existence. Cyanobacterial PCD is an altruistic reaction to stressful conditions that significantly enhances genetic diversity and inclusive fitness of the population. Recent bioinformatic analysis has revealed an abundance of death-related proteases, i.e. orthocaspases (OCAs) and their mutated variants, in cyanobacteria, with the larger genomes of morphologically complex strains harbouring most of them. Sequence analysis has depicted crucial accessory domains along with the proteolytic p20-like sub-domain in OCAs, predicting their functional versatility. However, the cascades involved in sensing death signals, their transduction, and the downstream expression and activation of OCAs remain to be elucidated. Here, we provide a comprehensive description of the attempts to identify mechanisms of PCD and the existence and importance of OCAs based on in silico approaches. We also review the evolutionary and ecological significance of PCD in cyanobacteria. In the future, the analysis of cyanobacterial PCD will identify novel proteins that have varied functional roles in signalling cascades and also help in understanding the incipient mechanism of PCD morphotype(s) from where eukaryotic PCD might have originated.
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Affiliation(s)
- Samujjal Bhattacharjee
- Laboratory of Microbial Genetics, Department of Botany, Banaras Hindu University, Varanasi, India
| | - Arun Kumar Mishra
- Laboratory of Microbial Genetics, Department of Botany, Banaras Hindu University, Varanasi, India
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36
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Ramisetty BCM, Sudhakari PA. 'Bacterial Programmed Cell Death': cellular altruism or genetic selfism? FEMS Microbiol Lett 2020; 367:5895326. [PMID: 32821912 DOI: 10.1093/femsle/fnaa141] [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: 01/16/2020] [Accepted: 08/18/2020] [Indexed: 01/01/2023] Open
Abstract
Cell-dependent propagation of the 'self' is the driver of all species, organisms and even genes. Conceivably, elimination of these entities is caused by cellular death. Then, how can genes that cause the death of the same cell evolve? Programmed cell death (PCD) is the gene-dependent self-inflicted death. In multicellular organisms, PCD of a cell confers fitness to the surviving rest of the organism, which thereby allows the selection of genes responsible for PCD. However, PCD in free-living bacteria is intriguing; the death of the cell is the death of the organism. How can such PCD genes be selected in unicellular organisms? The bacterial PCD in a population is proposed to confer fitness to the surviving kin in the form of sporulation, nutrition, infection-containment and matrix materials. While the cell-centred view leading to propositions of 'altruism' is enticing, the gene-centred view of 'selfism' is neglected. In this opinion piece, we reconceptualize the PCD propositions as genetic selfism (death due to loss/mutation of selfish genes) rather than cellular altruism (death for the conferment of fitness to kin). Within the scope and the available evidence, we opine that some of the PCD-like observations in bacteria seem to be the manifestation of genetic selfism by Restriction-Modification systems and Toxin-Antitoxin systems.
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Affiliation(s)
- Bhaskar Chandra Mohan Ramisetty
- Laboratory of Molecular Biology and Evolution, 312@ASK1, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, Tamil Nadu, India 613401
| | - Pavithra Anantharaman Sudhakari
- Laboratory of Molecular Biology and Evolution, 312@ASK1, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, Tamil Nadu, India 613401
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Wang PY, Xiang M, Luo M, Liu HW, Zhou X, Wu ZB, Liu LW, Li Z, Yang S. Novel piperazine-tailored ursolic acid hybrids as significant antibacterial agents targeting phytopathogens Xanthomonas oryzae pv. oryzae and X. axonopodis pv. citri probably directed by activation of apoptosis. PEST MANAGEMENT SCIENCE 2020; 76:2746-2754. [PMID: 32187443 DOI: 10.1002/ps.5822] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 03/11/2020] [Accepted: 03/18/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND Induced apoptosis is an effective technique that can reprogram cellular physiological and pathological processes to eradicate undesirable cells using their innate systems. Inspired by this, numerous apoptosis inducers have been developed to treat animal diseases, especially in the anticancer field. However, few studies have reported on the development of inductive agents that attack plant pathogens by activation of apoptosis. With the aim of exploring and discovering apoptosis inducers that target phytopathogens, a cluster of piperazine-tailored ursolic acid (UA) hybrids was systematically fabricated. RESULTS In vitro testing showed that the title molecules could inhibit the growth of two intractable bacterial strains, defined as Xanthomonas oryzae pv. oryzae and X. axonopodis pv. citri. The corresponding lowest EC50 values were 0.37 and 1.08 μg mL-1 , which exceed those of UA (>400 μg mL-1 ) and positive controls. Moreover, compounds 5u and 5v could manage bacterial blight in vivo using pot experiments. Flow cytometer analysis indicted that the title compounds could induce distinct apoptotic behaviors on tested bacteria. In-depth study revealed that the introduction of designed compounds could reduce the enzyme activities of catalase and superoxide dismutase, subsequently leading to the accumulation of reactive oxygen species. CONCLUSION This study promoted the development of apoptosis initiators for managing bacterial infections in agriculture by an innovative mode of action. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Pei-Yi Wang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Meng Xiang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Min Luo
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Hong-Wu Liu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Xiang Zhou
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Zhi-Bing Wu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Li-Wei Liu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
| | - Zhong Li
- College of Pharmacy, East China University of Science & Technology, Shanghai, China
| | - Song Yang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, China
- College of Pharmacy, East China University of Science & Technology, Shanghai, China
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Selection for Reducing Energy Cost of Protein Production Drives the GC Content and Amino Acid Composition Bias in Gene Transfer Agents. mBio 2020; 11:mBio.01206-20. [PMID: 32665274 PMCID: PMC7360931 DOI: 10.1128/mbio.01206-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Kin selection and group selection remain controversial topics in evolutionary biology. We argue that these types of selection are likely to operate in bacterial populations by showing that bacterial gene transfer agents (GTAs), but not related viruses, evolve under conditions of positive selection for the reduction of the energy cost of GTA particle production. We hypothesize that GTAs are dedicated devices mediating the survival of bacteria under conditions of nutrient limitation. The benefits conferred by GTAs under nutritional stress conditions appear to include horizontal dissemination of genes that could provide bacteria with enhanced capabilities for nutrient utilization and increases of nutrient availability occurring through the lysis of GTA-producing bacteria. Gene transfer agents (GTAs) are virus-like elements integrated into bacterial genomes, particularly, those of Alphaproteobacteria. The GTAs can be induced under conditions of nutritional stress, incorporate random fragments of bacterial DNA into miniphage particles, lyse the host cells, and infect neighboring bacteria, thus enhancing horizontal gene transfer. We show that GTA genes evolve under conditions of pronounced positive selection for the reduction of the energy cost of protein production as shown by comparison of the amino acid compositions with those of both homologous viral genes and host genes. The energy saving in GTA genes is comparable to or even more pronounced than that in the genes encoding the most abundant, essential bacterial proteins. In cases in which viruses acquire genes from GTAs, the bias in amino acid composition disappears in the course of evolution, showing that reduction of the energy cost of protein production is an important factor of evolution of GTAs but not bacterial viruses. These findings strongly suggest that GTAs represent bacterial adaptations rather than selfish, virus-like elements. Because GTA production kills the host cell and does not propagate the GTA genome, it appears likely that the GTAs are retained in the course of evolution via kin or group selection. Therefore, we hypothesize that GTAs facilitate the survival of bacterial populations under energy-limiting conditions through the spread of metabolic and transport capabilities via horizontal gene transfer and increases in nutrient availability resulting from the altruistic suicide of GTA-producing cells.
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39
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Genomic and Proteomic Characterization of the Extended-Spectrum β-Lactamase (ESBL)-Producing Escherichia coli Strain CCUG 73778: A Virulent, Nosocomial Outbreak Strain. Microorganisms 2020; 8:microorganisms8060893. [PMID: 32545759 PMCID: PMC7355845 DOI: 10.3390/microorganisms8060893] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/10/2020] [Accepted: 06/11/2020] [Indexed: 01/23/2023] Open
Abstract
Escherichia coli strain CCUG 78773 is a virulent extended-spectrum β-lactamase (ESBL)-producing ST131-O25b type strain isolated during an outbreak at a regional university hospital. The complete and closed genome sequence, comprising one chromosome (5,076,638 bp) and six plasmids (1718–161,372 bp), is presented. Characterization of the genomic features detected the presence of 59 potential antibiotic resistance factors, including three prevalent β-lactamases. Several virulence associated elements were determined, mainly related with adherence, invasion, biofilm formation and antiphagocytosis. Twenty-eight putative type II toxin-antitoxin systems were found. The plasmids were characterized, through in silico analyses, confirming the two β-lactamase-encoding plasmids to be conjugative, while the remaining plasmids were mobilizable. BLAST analysis of the plasmid sequences showed high similarity with plasmids in E. coli from around the world. Expression of many of the described virulence and AMR factors was confirmed by proteomic analyses, using bottom-up, liquid chromatography-tandem mass spectrometry (LC-MS/MS). The detailed characterization of E. coli strain CCUG 78773 provides a reference for the relevance of genetic elements, as well as the characterization of antibiotic resistance and the spread of bacteria harboring ESBL genes in the hospital environment.
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Lugongolo MY, Manoto SL, Ombinda-Lemboumba S, Maaza M, Mthunzi-Kufa P. The combination of low level laser therapy and efavirenz drastically reduces HIV infection in TZM-bl cells. Biomed J 2020; 44:S37-S47. [PMID: 35735083 PMCID: PMC9039092 DOI: 10.1016/j.bj.2020.05.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 05/06/2020] [Accepted: 05/26/2020] [Indexed: 11/24/2022] Open
Abstract
Background Human immunodeficiency virus (HIV) infection remains a global health challenge despite the use of antiretroviral therapy, which has led to a significant decline in the mortality rates. Owing to the unavailability of an effective treatment to completely eradicate the virus, researchers continue to explore new methods. Low level laser therapy (LLLT) has been widely used to treat different medical conditions and involves the exposure of cells or tissues to low levels of red and near infrared light. The study aimed to determine the effect of combining two unrelated therapies on HIV infection in TZM-bl cells. Methods In the current study, LLLT was combined with efavirenz, an HIV reverse transcriptase inhibitor to establish their impact on HIV infection in TZM-bl cells. Both the HIV infected and uninfected cells were laser irradiated using a wavelength of 640 nm with fluencies of 2–10 J/cm2. Results The impact of HIV, efavirenz and irradiation were determined 24 h post irradiation using biological assays. Luciferase assay results showed that the combination of LLLT and efavirenz significantly reduced HIV infection in cells, despite the undesirable effects observed in the cells as demonstrated by cell morphology, proliferation and cell integrity assay. Flow cytometry results demonstrated that cell death was mainly through necrosis while fluorescence microscopy showed the production of reactive oxygen species in HIV infected cells. Conclusion Efavirenz and LLLT significantly reduced HIV infection in TZM-bl cells. Furthermore, the death of HIV infected cells was due to necrosis.
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Ramisetty BCM. Regulation of Type II Toxin-Antitoxin Systems: The Translation-Responsive Model. Front Microbiol 2020; 11:895. [PMID: 32431690 PMCID: PMC7214741 DOI: 10.3389/fmicb.2020.00895] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 04/16/2020] [Indexed: 12/19/2022] Open
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Nitrogen starvation reveals the mitotic potential of mutants in the S/MAPK pathways. Nat Commun 2020; 11:1973. [PMID: 32332728 PMCID: PMC7181643 DOI: 10.1038/s41467-020-15880-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 03/24/2020] [Indexed: 02/08/2023] Open
Abstract
The genetics of quiescence is an emerging field compared to that of growth, yet both states generate spontaneous mutations and genetic diversity fueling evolution. Reconciling mutation rates in dividing conditions and mutation accumulation as a function of time in non-dividing situations remains a challenge. Nitrogen-starved fission yeast cells reversibly arrest proliferation, are metabolically active and highly resistant to a variety of stresses. Here, we show that mutations in stress- and mitogen-activated protein kinase (S/MAPK) signaling pathways are enriched in aging cultures. Targeted resequencing and competition experiments indicate that these mutants arise in the first month of quiescence and expand clonally during the second month at the expense of the parental population. Reconstitution experiments show that S/MAPK modules mediate the sacrifice of many cells for the benefit of some mutants. These findings suggest that non-dividing conditions promote genetic diversity to generate a social cellular environment prone to kin selection. Nitrogen-starved fission yeast cells survive for weeks without dividing. Here, the authors show that some of these surviving cells accumulate mutations in the stress- and mitogen-activated protein kinase pathways and outcompete their parental cells, which provide nutrients for the mutant cells.
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Abstract
Type II toxin-antitoxin (TA) systems are small genetic elements composed of a toxic protein and its cognate antitoxin protein, the latter counteracting the toxicity of the former. While TA systems were initially discovered on plasmids, functioning as addiction modules through a phenomenon called postsegregational killing, they were later shown to be massively present in bacterial chromosomes, often in association with mobile genetic elements. Extensive research has been conducted in recent decades to better understand the physiological roles of these chromosomally encoded modules and to characterize the conditions leading to their activation. Type II toxin-antitoxin (TA) systems are small genetic elements composed of a toxic protein and its cognate antitoxin protein, the latter counteracting the toxicity of the former. While TA systems were initially discovered on plasmids, functioning as addiction modules through a phenomenon called postsegregational killing, they were later shown to be massively present in bacterial chromosomes, often in association with mobile genetic elements. Extensive research has been conducted in recent decades to better understand the physiological roles of these chromosomally encoded modules and to characterize the conditions leading to their activation. The diversity of their proposed roles, ranging from genomic stabilization and abortive phage infection to stress modulation and antibiotic persistence, in conjunction with the poor understanding of TA system regulation, resulted in the generation of simplistic models, often refuted by contradictory results. This review provides an epistemological and critical retrospective on TA modules and highlights fundamental questions concerning their roles and regulations that still remain unanswered.
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Smith RP, Barraza I, Quinn RJ, Fortoul MC. The mechanisms and cell signaling pathways of programmed cell death in the bacterial world. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 352:1-53. [PMID: 32334813 DOI: 10.1016/bs.ircmb.2019.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
While programmed cell death was once thought to be exclusive to eukaryotic cells, there are now abundant examples of well regulated cell death mechanisms in bacteria. The mechanisms by which bacteria undergo programmed cell death are diverse, and range from the use of toxin-antitoxin systems, to prophage-driven cell lysis. Moreover, some bacteria have learned how to coopt programmed cell death systems in competing bacteria. Interestingly, many of the potential reasons as to why bacteria undergo programmed cell death may parallel those observed in eukaryotic cells, and may be altruistic in nature. These include protection against infection, recycling of nutrients, to ensure correct morphological development, and in response to stressors. In the following chapter, we discuss the molecular and signaling mechanisms by which bacteria undergo programmed cell death. We conclude by discussing the current open questions in this expanding field.
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Affiliation(s)
- Robert P Smith
- Department of Biological Sciences, Nova Southeastern University, Fort Lauderdale, FL, United States.
| | - Ivana Barraza
- Department of Biological Sciences, Nova Southeastern University, Fort Lauderdale, FL, United States
| | - Rebecca J Quinn
- Department of Biological Sciences, Nova Southeastern University, Fort Lauderdale, FL, United States
| | - Marla C Fortoul
- Department of Biological Sciences, Nova Southeastern University, Fort Lauderdale, FL, United States
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Sanchez I, Hernandez-Guerrero R, Mendez-Monroy PE, Martinez-Nuñez MA, Ibarra JA, Pérez-Rueda E. Evaluation of the Abundance of DNA-Binding Transcription Factors in Prokaryotes. Genes (Basel) 2020; 11:genes11010052. [PMID: 31947717 PMCID: PMC7017128 DOI: 10.3390/genes11010052] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/13/2019] [Accepted: 12/25/2019] [Indexed: 02/03/2023] Open
Abstract
The ability of bacteria and archaea to modulate metabolic process, defensive response, and pathogenic capabilities depend on their repertoire of genes and capacity to regulate the expression of them. Transcription factors (TFs) have fundamental roles in controlling these processes. TFs are proteins dedicated to favor and/or impede the activity of the RNA polymerase. In prokaryotes these proteins have been grouped into families that can be found in most of the different taxonomic divisions. In this work, the association between the expansion patterns of 111 protein regulatory families was systematically evaluated in 1351 non-redundant prokaryotic genomes. This analysis provides insights into the functional and evolutionary constraints imposed on different classes of regulatory factors in bacterial and archaeal organisms. Based on their distribution, we found a relationship between the contents of some TF families and genome size. For example, nine TF families that represent 43.7% of the complete collection of TFs are closely associated with genome size; i.e., in large genomes, members of these families are also abundant, but when a genome is small, such TF family sizes are decreased. In contrast, almost 102 families (56.3% of the collection) do not exhibit or show only a low correlation with the genome size, suggesting that a large proportion of duplication or gene loss events occur independently of the genome size and that various yet-unexplored questions about the evolution of these TF families remain. In addition, we identified a group of families that have a similar distribution pattern across Bacteria and Archaea, suggesting common functional and probable coevolution processes, and a group of families universally distributed among all the genomes. Finally, a specific association between the TF families and their additional domains was identified, suggesting that the families sense specific signals or make specific protein-protein contacts to achieve the regulatory roles.
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Affiliation(s)
- Israel Sanchez
- Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, Unidad Académica Yucatán, Mérida.C.P. 97302, Yucatán, Mexico; (I.S.); (R.H.-G.); (P.E.M.-M.)
| | - Rafael Hernandez-Guerrero
- Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, Unidad Académica Yucatán, Mérida.C.P. 97302, Yucatán, Mexico; (I.S.); (R.H.-G.); (P.E.M.-M.)
| | - Paul Erick Mendez-Monroy
- Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, Unidad Académica Yucatán, Mérida.C.P. 97302, Yucatán, Mexico; (I.S.); (R.H.-G.); (P.E.M.-M.)
| | - Mario Alberto Martinez-Nuñez
- Unidad Académica de Ciencias y Tecnología de Yucatán, UMDI-Sisal. Facultad de Ciencias, UNAM, Mérida C.P. 97302, Yucatán, Mexico;
| | - Jose Antonio Ibarra
- Laboratorio de Genética Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México C.P. 11340, Mexico;
| | - Ernesto Pérez-Rueda
- Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, Unidad Académica Yucatán, Mérida.C.P. 97302, Yucatán, Mexico; (I.S.); (R.H.-G.); (P.E.M.-M.)
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago C.P. 7500000, Chile
- Correspondence: ; Tel.: +52-9994060003 (ext. 7610)
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Durand PM, Barreto Filho MM, Michod RE. Cell Death in Evolutionary Transitions in Individuality. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2019; 92:651-662. [PMID: 31866780 PMCID: PMC6913816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Programmed cell death (PCD) in cell groups and microbial communities affects population structures, nutrient recycling, and sociobiological interactions. A less explored area is the role played by PCD in the emergence of higher-level individuals. Here, we examine how cell death impacted evolutionary transitions in individuality (ETIs). The focus is on three specific ETIs - the emergence of the eukaryote cell, multicellularity, and social insects - and we review the theoretical and empirical evidence for the role of PCD in these three transitions. We find that PCD likely contributed to many of the processes involved in eukaryogenesis and the transition to multicellularity. PCD is important for the formation of cooperative groups and is a mechanism by which mutual dependencies between individuals evolve. PCD is also a conflict mediator and involved in division of labor in social groups and in the origin of new cell types. In multicellularity, PCD facilitates the transfer of fitness to the higher-level individual. In eusocial insects, PCD of the gonadal cells in workers is the basis for conflict mediation and the division of labor in the colony. In the three ETIs discussed here, PCD likely played an essential role, without which alternate mechanisms would have been necessary for these increases in complexity to occur.
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Affiliation(s)
- Pierre M. Durand
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa,To whom all correspondence should be addressed: Pierre M. Durand, Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, 2000, South Africa; ; ORCID number 0000-0002-9614-1371
| | - Marcelo M. Barreto Filho
- Post-Graduate Program in Ecology and Natural Resources, Department of Botany, Phycology Laboratory, Federal University of São Carlos, São Carlos, Brazil
| | - Richard E. Michod
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ
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Li T, Jung B, Park SY, Lee J. Survival Factor Gene FgSvf1 Is Required for Normal Growth and Stress Resistance in Fusarium graminearum. THE PLANT PATHOLOGY JOURNAL 2019; 35:393-405. [PMID: 31632215 PMCID: PMC6788415 DOI: 10.5423/ppj.oa.03.2019.0070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 05/29/2019] [Accepted: 05/30/2019] [Indexed: 06/10/2023]
Abstract
Survival factor 1 (Svf1) is a protein involved in cell survival pathways. In Saccharomyces cerevisiae, Svf1 is required for the diauxic growth shift and survival under stress conditions. In this study, we characterized the role of FgSvf1, the Svf1 homolog in the homothallic ascomycete fungus Fusarium graminearum. In the FgSvf1 deletion mutant, conidial germination was delayed, vegetative growth was reduced, and pathogenicity was completely abolished. Although the FgSvf1 deletion mutant produced perithecia, the normal maturation of ascospore was dismissed in deletion mutant. The FgSvf1 deletion mutant also showed reduced resistance to osmotic, fungicide, and cold stress and reduced sensitivity to oxidative stress when compared to the wild-type strain. In addition, we showed that FgSvf1 affects glycolysis, which results in the abnormal vegetative growth in the FgSvf1 deletion mutant. Further, intracellular reactive oxygen species (ROS) accumulated in the FgSvf1 deletion mutant, and this accumulated ROS might be related to the reduced sensitivity to oxidative stress and the reduced resistance to cold stress and fungicide stress. Overall, understanding the role of FgSvf1 in F. graminearum provides a new target to control F. graminearum infections in fields.
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Affiliation(s)
- Taiying Li
- Department of Applied Biology, Dong-A University, Busan 49315,
Korea
| | - Boknam Jung
- Department of Applied Biology, Dong-A University, Busan 49315,
Korea
| | - Sook-Young Park
- Department of Plant Medicine, Sunchon National University, Suncheon 57922,
Korea
| | - Jungkwan Lee
- Department of Applied Biology, Dong-A University, Busan 49315,
Korea
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Yee R, Feng J, Wang J, Chen J, Zhang Y. Identification of Genes Regulating Cell Death in Staphylococcus aureus. Front Microbiol 2019; 10:2199. [PMID: 31632363 PMCID: PMC6779855 DOI: 10.3389/fmicb.2019.02199] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/09/2019] [Indexed: 12/20/2022] Open
Abstract
Staphylococcus aureus is an opportunistic pathogen that causes acute and chronic infections. Due to S. aureus's highly resistant and persistent nature, it is paramount to identify better drug targets in order to eradicate S. aureus infections. Despite the efforts in understanding bacterial cell death, the genes, and pathways of S. aureus cell death remain elusive. Here, we performed a genome-wide screen using a transposon mutant library to study the genetic mechanisms involved in S. aureus cell death. Using a precisely controlled heat-ramp and acetic acid exposure assays, mutations in 27 core genes (hsdR1, hslO, nsaS, sspA, folD, mfd, vraF, kdpB, USA300HOU_2684, 0868, 0369, 0420, 1154, 0142, 0930, 2590, 0997, 2559, 0044, 2004, 1209, 0152, 2455, 0154, 2386, 0232, 0350 involved in transporters, transcription, metabolism, peptidases, kinases, transferases, SOS response, nucleic acid, and protein synthesis) caused the bacteria to be more death-resistant. In addition, we identified mutations in 10 core genes (capA, gltT, mnhG1, USA300HOU_1780, 2496, 0200, 2029, 0336, 0329, 2386, involved in transporters, metabolism, transcription, and cell wall synthesis) from heat-ramp and acetic acid that caused the bacteria to be more death-sensitive or with defect in persistence. Interestingly, death-resistant mutants were more virulent than the parental strain USA300 and caused increased mortality in a Caenorhabditis elegans infection model. Conversely, death-sensitive mutants were less persistent and formed fewer persister cells upon exposure to different classes of antibiotics. These findings provide new insights into the mechanisms of S. aureus cell death and offer new therapeutic targets for developing more effective treatments for infections caused by S. aureus.
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Affiliation(s)
- Rebecca Yee
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States
| | - Jie Feng
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States
| | - Jiou Wang
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States
| | - Jiazhen Chen
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Ying Zhang
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States
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Abstract
Longevity reflects the ability to maintain homeostatic conditions necessary for life as an organism ages. A long-lived organism must contend not only with environmental hazards but also with internal entropy and macromolecular damage that result in the loss of fitness during ageing, a phenomenon known as senescence. Although central to many of the core concepts in biology, ageing and longevity have primarily been investigated in sexually reproducing, multicellular organisms. However, growing evidence suggests that microorganisms undergo senescence, and can also exhibit extreme longevity. In this Review, we integrate theoretical and empirical insights to establish a unified perspective on senescence and longevity. We discuss the evolutionary origins, genetic mechanisms and functional consequences of microbial ageing. In addition to having biomedical implications, insights into microbial ageing shed light on the role of ageing in the origin of life and the upper limits to longevity.
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Popp PF, Mascher T. Coordinated Cell Death in Isogenic Bacterial Populations: Sacrificing Some for the Benefit of Many? J Mol Biol 2019; 431:4656-4669. [PMID: 31029705 DOI: 10.1016/j.jmb.2019.04.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 04/11/2019] [Accepted: 04/14/2019] [Indexed: 01/22/2023]
Abstract
Antibiotics are classically perceived as biological weapons that bacteria produce to hold their ground against competing species in their natural habitat. But in the context of multicellular differentiation processes, antimicrobial compounds sometimes also play a role in intraspecies competition, resulting in the death of a sub-population of genetically identical siblings for the benefit of the population. Such a strategy is based on the diversification and hence phenotypic heterogeneity of an isogenic bacterial population. This review article will address three such phenomena. In Bacillus subtilis, cannibalism is a differentiation strategy that enhances biofilm formation, prolongs or potentially even prevents full commitment to endospore formation under starvation conditions, and protects cells within the biofilm against competing species. The nutrients released by lysed cells can be used by the toxin producers, thereby delaying the full activation of the master regulator of sporulation. A related strategy is associated with the initiation of competence development under nutrient excess in Streptococcus pneumoniae. This process, termed fratricide, causes allolysis in a sub-population and is thought to enhance genetic diversity within the species. In Myxococcus xanthus, a large fraction of the population undergoes programmed cell death during the formation of fruiting bodies. This sacrifice ensures the survival of the sporulating sub-population by providing nutrients and hence energy to complete this differentiation process. The biological relevance and underlying regulatory mechanisms of these three processes will be discussed in order to extract common features of such strategies. Moreover, open questions and future challenges will be addressed.
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Affiliation(s)
- Philipp F Popp
- Institute of Microbiology, Technische Universität (TU) Dresden, 01062 Dresden, Germany
| | - Thorsten Mascher
- Institute of Microbiology, Technische Universität (TU) Dresden, 01062 Dresden, Germany.
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