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Cao Y, Zang T, Qiu T, Xu Z, Chen X, Fan X, Zhang Q, Huang Y, Liu J, Wu N, Shen N, Bai J, Li G, Huang J, Liu Y. Does PM 1 exposure during pregnancy impact the gut microbiota of mothers and neonates? ENVIRONMENTAL RESEARCH 2023; 231:116304. [PMID: 37268213 DOI: 10.1016/j.envres.2023.116304] [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: 12/26/2022] [Revised: 05/12/2023] [Accepted: 05/31/2023] [Indexed: 06/04/2023]
Abstract
BACKGROUND Ambient air pollutant exposure can change the composition of gut microbiota at 6-months of age, but there is no epidemiological evidence on the impacts of exposure to particulate matter with an aerodynamic diameter ≤1 μm (PM1) during pregnancy on gut microbiota in mothers and neonates. We aimed to determine if gestational PM1 exposure is associated with the gut microbiota of mothers and neonates. METHODS Leveraging a mother-infant cohort from the central region of China, we estimated the exposure concentrations of PM1 during pregnancy based on residential address records. The gut microbiota of mothers and neonates was analyzed using 16 S rRNA V3-V4 gene sequences. Functional pathway analyses of 16 S rRNA V3-V4 bacterial communities were conducted using Tax4fun. The impact of PM1 exposure on α-diversity, composition, and function of gut microbiota in mothers and neonates was evaluated using multiple linear regression, controlling for nitrogen dioxide (NO2) and ozone (O3). Permutation multivariate analysis of variance (PERMANOVA) was used to analyze the interpretation degree of PM1 on the sample differences at the OTU level using the Bray-Curtis distance algorithm. RESULTS Gestational PM1 exposure was positively associated with the α-diversity of gut microbiota in neonates and explained 14.8% (adj. P = 0.026) of the differences in community composition among neonatal samples. In contrast, gestational PM1 exposure had no impact on the α- and β-diversity of gut microbiota in mothers. Gestational PM1 exposure was positively associated with phylum Actinobacteria of gut microbiota in mothers, and genera Clostridium_sensu_stricto_1, Streptococcus, Faecalibacterium of gut microbiota in neonates. At Kyoto Encyclopedia of Genes and Genomes pathway level 3, the functional analysis results showed that gestational PM1 exposure significantly down-regulated Nitrogen metabolism in mothers, as well as Two-component system and Pyruvate metabolism in neonates. While Purine metabolism, Aminoacyl-tRNA biosynthesis, Pyrimidine metabolism, and Ribosome in neonates were significantly up-regulated. CONCLUSIONS Our study provides the first evidence that exposure to PM1 has a significant impact on the gut microbiota of mothers and neonates, especially on the diversity, composition, and function of neonatal meconium microbiota, which may have important significance for maternal health management in the future.
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Affiliation(s)
- Yanan Cao
- School of Public Health, Wuhan University, Wuhan, 430071, China
| | - Tianzi Zang
- Center for Women's and Children's Health, Wuhan University School of Nursing, Wuhan University, Wuhan, 430071, China
| | - Tianlai Qiu
- Center for Women's and Children's Health, Wuhan University School of Nursing, Wuhan University, Wuhan, 430071, China
| | - Zhihu Xu
- Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, Beijing, 100191, China
| | - Xiangxu Chen
- Center for Women's and Children's Health, Wuhan University School of Nursing, Wuhan University, Wuhan, 430071, China
| | - Xiaoxiao Fan
- Center for Women's and Children's Health, Wuhan University School of Nursing, Wuhan University, Wuhan, 430071, China
| | - Qianping Zhang
- Center for Women's and Children's Health, Wuhan University School of Nursing, Wuhan University, Wuhan, 430071, China
| | - Yingjuan Huang
- Center for Women's and Children's Health, Wuhan University School of Nursing, Wuhan University, Wuhan, 430071, China
| | - Jun Liu
- Center for Women's and Children's Health, Wuhan University School of Nursing, Wuhan University, Wuhan, 430071, China
| | - Ni Wu
- Center for Women's and Children's Health, Wuhan University School of Nursing, Wuhan University, Wuhan, 430071, China
| | - Natalie Shen
- Emory University Rollins School of Public Health, 1520 Clifton Road, Atlanta, GA, 30322, USA
| | - Jinbing Bai
- Emory University Nell Hodgson Woodruff School of Nursing, 1520 Clifton Road, Atlanta, GA, 30322, USA
| | - Guoxing Li
- Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, Beijing, 100191, China
| | - Jing Huang
- Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, Beijing, 100191, China.
| | - Yanqun Liu
- Center for Women's and Children's Health, Wuhan University School of Nursing, Wuhan University, Wuhan, 430071, China.
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2
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Chow EWL, Mei Pang L, Wang Y. Impact of the host microbiota on fungal infections: new possibilities for intervention? Adv Drug Deliv Rev 2023; 198:114896. [PMID: 37211280 DOI: 10.1016/j.addr.2023.114896] [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: 03/10/2023] [Revised: 05/15/2023] [Accepted: 05/16/2023] [Indexed: 05/23/2023]
Abstract
Many human fungal pathogens are opportunistic. They are primarily benign residents of the human body and only become infectious when the host's immunity and microbiome are compromised. Bacteria dominate the human microbiome, playing an essential role in keeping fungi harmless and acting as the first line of defense against fungal infection. The Human Microbiome Project, launched by NIH in 2007, has stimulated extensive investigation and significantly advanced our understanding of the molecular mechanisms governing the interaction between bacteria and fungi, providing valuable insights for developing future antifungal strategies by exploiting the interaction. This review summarizes recent progress in this field and discusses new possibilities and challenges. We must seize the opportunities presented by researching bacterial-fungal interplay in the human microbiome to address the global spread of drug-resistant fungal pathogens and the drying pipelines of effective antifungal drugs.
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Affiliation(s)
- Eve W L Chow
- A*STAR Infectious Diseases Laboratories (ID Labs), Agency for Science and Technology Research (A*STAR), 8A Biomedical Grove, #05-13 Immunos, Singapore 138648
| | - Li Mei Pang
- A*STAR Infectious Diseases Laboratories (ID Labs), Agency for Science and Technology Research (A*STAR), 8A Biomedical Grove, #05-13 Immunos, Singapore 138648
| | - Yue Wang
- A*STAR Infectious Diseases Laboratories (ID Labs), Agency for Science and Technology Research (A*STAR), 8A Biomedical Grove, #05-13 Immunos, Singapore 138648; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore.
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3
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Escobar-Salom M, Barceló IM, Jordana-Lluch E, Torrens G, Oliver A, Juan C. Bacterial virulence regulation through soluble peptidoglycan fragments sensing and response: knowledge gaps and therapeutic potential. FEMS Microbiol Rev 2023; 47:fuad010. [PMID: 36893807 PMCID: PMC10039701 DOI: 10.1093/femsre/fuad010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 02/10/2023] [Accepted: 03/07/2023] [Indexed: 03/11/2023] Open
Abstract
Given the growing clinical-epidemiological threat posed by the phenomenon of antibiotic resistance, new therapeutic options are urgently needed, especially against top nosocomial pathogens such as those within the ESKAPE group. In this scenario, research is pushed to explore therapeutic alternatives and, among these, those oriented toward reducing bacterial pathogenic power could pose encouraging options. However, the first step in developing these antivirulence weapons is to find weak points in the bacterial biology to be attacked with the goal of dampening pathogenesis. In this regard, during the last decades some studies have directly/indirectly suggested that certain soluble peptidoglycan-derived fragments display virulence-regulatory capacities, likely through similar mechanisms to those followed to regulate the production of several β-lactamases: binding to specific transcriptional regulators and/or sensing/activation of two-component systems. These data suggest the existence of intra- and also intercellular peptidoglycan-derived signaling capable of impacting bacterial behavior, and hence likely exploitable from the therapeutic perspective. Using the well-known phenomenon of peptidoglycan metabolism-linked β-lactamase regulation as a starting point, we gather and integrate the studies connecting soluble peptidoglycan sensing with fitness/virulence regulation in Gram-negatives, dissecting the gaps in current knowledge that need filling to enable potential therapeutic strategy development, a topic which is also finally discussed.
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Affiliation(s)
- María Escobar-Salom
- Research Unit and Microbiology Department, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Crtra. Valldemossa 79, 07010 Palma, Spain
- Centro de Investigación Biomédica en Red, Enfermedades Infecciosas (CIBERINFEC). Av. Monforte de Lemos 3-5, 28029, Madrid, Spain
| | - Isabel María Barceló
- Research Unit and Microbiology Department, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Crtra. Valldemossa 79, 07010 Palma, Spain
- Centro de Investigación Biomédica en Red, Enfermedades Infecciosas (CIBERINFEC). Av. Monforte de Lemos 3-5, 28029, Madrid, Spain
| | - Elena Jordana-Lluch
- Research Unit and Microbiology Department, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Crtra. Valldemossa 79, 07010 Palma, Spain
| | - Gabriel Torrens
- Research Unit and Microbiology Department, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Crtra. Valldemossa 79, 07010 Palma, Spain
- Centro de Investigación Biomédica en Red, Enfermedades Infecciosas (CIBERINFEC). Av. Monforte de Lemos 3-5, 28029, Madrid, Spain
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University. Försörjningsvägen 2A, SE-901 87 Umeå, Sweden
| | - Antonio Oliver
- Research Unit and Microbiology Department, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Crtra. Valldemossa 79, 07010 Palma, Spain
- Centro de Investigación Biomédica en Red, Enfermedades Infecciosas (CIBERINFEC). Av. Monforte de Lemos 3-5, 28029, Madrid, Spain
| | - Carlos Juan
- Research Unit and Microbiology Department, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Crtra. Valldemossa 79, 07010 Palma, Spain
- Centro de Investigación Biomédica en Red, Enfermedades Infecciosas (CIBERINFEC). Av. Monforte de Lemos 3-5, 28029, Madrid, Spain
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4
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Crump GM, Rozovosky S, Grimes CL. Purification and Characterization of a Stable, Membrane-Associated Peptidoglycan Responsive Adenylate Cyclase LRR Domain from Human Commensal Candida albicans. Biochemistry 2022; 61:2856-2860. [PMID: 35816699 PMCID: PMC9771868 DOI: 10.1021/acs.biochem.2c00305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The evolutionarily conserved leucine rich repeat (LRR) protein domain is a unique structural motif found in many viral, bacterial, archaeal, and eukaryotic proteins. The LRR domain serves many roles, including being a signaling domain and a pathogen recognition receptor. In the human innate immune system, it serves an essential role by recognizing fragments of bacterial cell walls. Interestingly, the human fungal pathogen Candida albicans also uses an LRR domain-containing protein, Cyrp1, to sense bacterial cell wall fragments. However, the dynamics of signaling and detection of bacterial peptidoglycan fragments by the LRR of Cyr1p remains poorly characterized. Here we develop optimal recombinant expression workflows and provide characterization of the entire region of the LRR domain of Cyr1p as a peripheral membrane protein. Using a newly designed peptidoglycan enrichment bead assay, we demonstrate that this domain can bind bacterial peptidoglycan fragments under native conditions. The new membrane-associated Cyr1p-LRR construct sets the stage for the development of antifungal agents via high-throughput campaigns to inhibit cell wall-Cyr1p interactions.
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Affiliation(s)
- Geneva Maddison Crump
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Sharon Rozovosky
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Catherine L. Grimes
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
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5
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Kang SJ, Yang J, Lee NY, Lee CH, Park IB, Park SW, Lee HJ, Park HW, Yun HS, Chun T. Monitoring Cellular Immune Responses after Consumption of Selected
Probiotics in Immunocompromised Mice. Food Sci Anim Resour 2022; 42:903-914. [PMID: 36133633 PMCID: PMC9478974 DOI: 10.5851/kosfa.2022.e44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/02/2022] [Accepted: 08/11/2022] [Indexed: 11/25/2022] Open
Abstract
Probiotics are currently considered as one of tools to modulate immune responses
under specific clinical conditions. The purpose of this study was to evaluate
whether oral administration of three different probiotics
(Lactiplantibacillus plantarum CJLP243, CJW55-10, and
CJLP475) could evoke a cell-mediated immunity in immunodeficient mice. Before
conducting in vivo experiments, we examined the in
vitro potency of these probiotics for macrophage activation. After
co-culture with these probiotics, bone marrow derived macrophages (BMDMs)
produced significant amounts of proinflammatory cytokines including
interleukin-6 (IL-6), IL-12, and tumor necrosis factor-α (TNF-α).
Levels of inducible nitric oxide synthase (inos) and
co-stimulatory molecules (CD80 and CD86) were also upregulated in BMDMs after
treatment with some of these probiotics. To establish an immunocompromised
animal model, we intraperitoneally injected mice with cyclophosphamide on day 0
and again on day 2. Starting day 3, we orally administered probiotics every day
for the last 15 d. After sacrificing experimental mice on day 18, splenocytes
were isolated and co-cultured with these probiotics for 3 d to measure levels of
several cytokines and immune cell proliferation. Results clearly indicated that
the consumption of all three probiotic strains promoted secretion of
interferon-γ (IFN-γ), IL-1β, IL-6, IL-12, and TNF-α.
NK cell cytotoxicity and proliferation of immune cells were also increased.
Taken together, our data strongly suggest that consumption of some probiotics
might induce cell-mediated immune responses in immunocompromised mice.
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Affiliation(s)
- Seok-Jin Kang
- Department of Biotechnology, College of
Life Sciences and Biotechnology, Korea University, Seoul
02841, Korea
- Institute of Animal Molecular
Biotechnology, Korea University, Seoul 02841, Korea
| | - Jun Yang
- Department of Biotechnology, College of
Life Sciences and Biotechnology, Korea University, Seoul
02841, Korea
| | - Na-Young Lee
- Department of Biotechnology, College of
Life Sciences and Biotechnology, Korea University, Seoul
02841, Korea
| | - Chang-Hee Lee
- Department of Biotechnology, College of
Life Sciences and Biotechnology, Korea University, Seoul
02841, Korea
- Institute of Animal Molecular
Biotechnology, Korea University, Seoul 02841, Korea
| | - In-Byung Park
- Department of Biotechnology, College of
Life Sciences and Biotechnology, Korea University, Seoul
02841, Korea
- Institute of Animal Molecular
Biotechnology, Korea University, Seoul 02841, Korea
| | - Si-Won Park
- Department of Biotechnology, College of
Life Sciences and Biotechnology, Korea University, Seoul
02841, Korea
| | - Hyeon Jeong Lee
- Department of Biotechnology, College of
Life Sciences and Biotechnology, Korea University, Seoul
02841, Korea
| | - Hae-Won Park
- Department of Biotechnology, College of
Life Sciences and Biotechnology, Korea University, Seoul
02841, Korea
| | | | - Taehoon Chun
- Department of Biotechnology, College of
Life Sciences and Biotechnology, Korea University, Seoul
02841, Korea
- Corresponding author: Taehoon
Chun, Department of Biotechnology, College of Life Sciences and Biotechnology,
Korea University, Seoul 02841, Korea, Tel: +82-2-3290-3069, E-mail:
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6
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Jiang QL, Lu Y, Zhang MJ, Cui ZY, Pei ZM, Li WH, Lu LG, Wang JJ, Lu YY. Mucosal bacterial dysbiosis in patients with nodular lymphoid hyperplasia in the terminal ileum. World J Gastroenterol 2022; 28:811-824. [PMID: 35317097 PMCID: PMC8900573 DOI: 10.3748/wjg.v28.i8.811] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/19/2021] [Accepted: 01/14/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Nodular lymphoid hyperplasia (NLH) in the small intestine is a rare benign lesion characterized by multiple small nodules on the intestinal surface. Patients with terminal ileal NLH may experience long-term abdominal pain, diarrhea, and abdominal distension, among other symptoms. Supplementation with probiotics could mitigate these symptoms. NLH is linked to the immune system, and it may result from accumulation of plasma-cell precursors due to a maturational defect during the development of B lymphocytes. The intestinal microbiome plays an essential role in the immune system. Thus, we speculate that the gut flora plays a key role in terminal ileal NLH.
AIM To explore the correlation between intestinal flora and terminal ileal NLH.
METHODS We collected mucosal biopsy samples that were obtained via colonoscopy from 15 patients with terminal ileal NLH (the test group) and 15 normal subjects (the control group). We subsequently performed 16S-rRNA gene amplicon sequencing of these samples, and the results were evaluated using alpha diversity, beta diversity and microbial composition analyses. The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States was used to predict the metabolic pathways and orthologous groups according to the Kyoto Encyclopedia of Genes and Genomes database.
RESULTS Compared with the control group, the terminal ileal NLH group showed an increased alpha diversity (P < 0.05). The overall intestinal microbiota in the NLH group was significantly different from that of the control group (P < 0.05), implying that there was the dysbiosis in the terminal ileal NLH patients. The relative abundance of phylum Bacteroidetes was significantly lower in the NLH group, while that of Patescibacteria and Campilobacterota was significantly higher. The genus Bacteroides was the dominant gut microbiota in both groups, but its abundance was significantly lower in the test group than it was in the control group. Conversely, the relative abundances of Haemophilus, Streptococcus, Pseudomonas, Actinomyces, TM7X, Fusobacterium nucleatum, Parvimonas, Granulicatella, Helicobacter, and the [Eubacterium] nodatum group were significantly higher in the test group than they were in the control group. In addition, several altered metabolic pathways, orthologous groups, and modules were found. For example, the Peptidoglycan biosynthesis and Aminoacyl tRNA biosynthesis were both increased in the test group.
CONCLUSION Maintaining the microbial balance and supplementing targeted protective bacteria could improve symptoms and potentially reduce the risk of lymphoma transformation in patients with terminal ileal NLH.
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Affiliation(s)
- Qiao-Li Jiang
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201803, China
| | - You Lu
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201803, China
| | - Meng-Jie Zhang
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201803, China
| | - Zhen-Yu Cui
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201803, China
| | - Zhong-Mei Pei
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201803, China
| | - Wen-Hua Li
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201803, China
| | - Lun-Gen Lu
- Department of Gastroenterology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China
| | - Jing-Jing Wang
- Shanghai Key Laboratory of Pancreatic Diseases, Institute of Translational Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China
| | - Ying-Ying Lu
- Department of Gastroenterology, Jiading Branch of Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201803, China
- Department of Gastroenterology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China
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7
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Brown AR, Wodzanowski KA, Santiago CC, Hyland SN, Follmar JL, Asare-Okai P, Grimes CL. Protected N-Acetyl Muramic Acid Probes Improve Bacterial Peptidoglycan Incorporation via Metabolic Labeling. ACS Chem Biol 2021; 16:1908-1916. [PMID: 34506714 DOI: 10.1021/acschembio.1c00268] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Metabolic glycan probes have emerged as an excellent tool to investigate vital questions in biology. Recently, methodology to incorporate metabolic bacterial glycan probes into the cell wall of a variety of bacterial species has been developed. In order to improve this method, a scalable synthesis of the peptidoglycan precursors is developed here, allowing for access to essential peptidoglycan immunological fragments and cell wall building blocks. The question was asked if masking polar groups of the glycan probe would increase overall incorporation, a common strategy exploited in mammalian glycobiology. Here, we show, through cellular assays, that E. coli do not utilize peracetylated peptidoglycan substrates but do employ methyl esters. The 10-fold improvement of probe utilization indicates that (i) masking the carboxylic acid is favorable for transport and (ii) bacterial esterases are capable of removing the methyl ester for use in peptidoglycan biosynthesis. This investigation advances bacterial cell wall biology, offering a prescription on how to best deliver and utilize bacterial metabolic glycan probes.
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Affiliation(s)
- Ashley R. Brown
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Kimberly A. Wodzanowski
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Cintia C. Santiago
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Stephen N. Hyland
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Julianna L. Follmar
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - PapaNii Asare-Okai
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Catherine Leimkuhler Grimes
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
- Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, United States
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8
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Planas A. Peptidoglycan Deacetylases in Bacterial Cell Wall Remodeling and Pathogenesis. Curr Med Chem 2021; 29:1293-1312. [PMID: 34525907 DOI: 10.2174/0929867328666210915113723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 07/24/2021] [Accepted: 07/26/2021] [Indexed: 11/22/2022]
Abstract
The bacterial cell wall peptidoglycan (PG) is a dynamic structure that is constantly synthesized, re-modeled and degraded during bacterial division and growth. Post-synthetic modifications modulate the action of endogenous autolysis during PG lysis and remodeling for growth and sporulation, but also they are a mechanism used by pathogenic bacteria to evade the host innate immune system. Modifica-tions of the glycan backbone are limited to the C-2 amine and the C-6 hydroxyl moieties of either Glc-NAc or MurNAc residues. This paper reviews the functional roles and properties of peptidoglycan de-N-acetylases (distinct PG GlcNAc and MurNAc deacetylases) and recent progress through genetic stud-ies and biochemical characterization to elucidate their mechanism of action, 3D structures, substrate specificities and biological functions. Since they are virulence factors in pathogenic bacteria, peptidogly-can deacetylases are potential targets for the design of novel antimicrobial agents.
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Affiliation(s)
- Antoni Planas
- Laboratory of Biochemistry, Institut Químic de Sarrià. University Ramon Llull, 08017 Barcelona. Spain
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9
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MexAB-OprM Efflux Pump Interaction with the Peptidoglycan of Escherichia coli and Pseudomonas aeruginosa. Int J Mol Sci 2021; 22:ijms22105328. [PMID: 34070225 PMCID: PMC8158685 DOI: 10.3390/ijms22105328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 11/17/2022] Open
Abstract
One of the major families of membrane proteins found in prokaryote genome corresponds to the transporters. Among them, the resistance-nodulation-cell division (RND) transporters are highly studied, as being responsible for one of the most problematic mechanisms used by bacteria to resist to antibiotics, i.e., the active efflux of drugs. In Gram-negative bacteria, these proteins are inserted in the inner membrane and form a tripartite assembly with an outer membrane factor and a periplasmic linker in order to cross the two membranes to expulse molecules outside of the cell. A lot of information has been collected to understand the functional mechanism of these pumps, especially with AcrAB-TolC from Escherichia coli, but one missing piece from all the suggested models is the role of peptidoglycan in the assembly. Here, by pull-down experiments with purified peptidoglycans, we precise the MexAB-OprM interaction with the peptidoglycan from Escherichia coli and Pseudomonas aeruginosa, highlighting a role of the peptidoglycan in stabilizing the MexA-OprM complex and also differences between the two Gram-negative bacteria peptidoglycans.
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10
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A synthetic 5,3-cross-link in the cell wall of rod-shaped Gram-positive bacteria. Proc Natl Acad Sci U S A 2021; 118:2100137118. [PMID: 33836615 DOI: 10.1073/pnas.2100137118] [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] [Indexed: 12/25/2022] Open
Abstract
Gram-positive bacteria assemble a multilayered cell wall that provides tensile strength to the cell. The cell wall is composed of glycan strands cross-linked by nonribosomally synthesized peptide stems. Herein, we modify the peptide stems of the Gram-positive bacterium Bacillus subtilis with noncanonical electrophilic d-amino acids, which when in proximity to adjacent stem peptides form novel covalent 5,3-cross-links. Approximately 20% of canonical cell-wall cross-links can be replaced with synthetic cross-links. While a low level of synthetic cross-link formation does not affect B. subtilis growth and phenotype, at higher levels cell growth is perturbed and bacteria elongate. A comparison of the accumulation of synthetic cross-links over time in Gram-negative and Gram-positive bacteria highlights key differences between them. The ability to perturb cell-wall architecture with synthetic building blocks provides a novel approach to studying the adaptability, elasticity, and porosity of bacterial cell walls.
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