1
|
Hashimi A, Tocheva EI. Cell envelope diversity and evolution across the bacterial tree of life. Nat Microbiol 2024:10.1038/s41564-024-01812-9. [PMID: 39294462 DOI: 10.1038/s41564-024-01812-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 08/16/2024] [Indexed: 09/20/2024]
Abstract
The bacterial cell envelope is a complex multilayered structure conserved across all bacterial phyla. It is categorized into two main types based on the number of membranes surrounding the cell. Monoderm bacteria are enclosed by a single membrane, whereas diderm cells are distinguished by the presence of a second, outer membrane (OM). An ancient divide in the bacterial domain has resulted in two major clades: the Gracilicutes, consisting strictly of diderm phyla; and the Terrabacteria, encompassing monoderm and diderm species with diverse cell envelope architectures. Recent structural and phylogenetic advancements have improved our understanding of the diversity and evolution of the OM across the bacterial tree of life. Here we discuss cell envelope variability within major bacterial phyla and focus on conserved features found in diderm lineages. Characterizing the mechanisms of OM biogenesis and the evolutionary gains and losses of the OM provides insights into the primordial cell and the last universal common ancestor from which all living organisms subsequently evolved.
Collapse
Affiliation(s)
- Ameena Hashimi
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Elitza I Tocheva
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada.
| |
Collapse
|
2
|
Beaud Benyahia B, Taib N, Beloin C, Gribaldo S. Terrabacteria: redefining bacterial envelope diversity, biogenesis and evolution. Nat Rev Microbiol 2024:10.1038/s41579-024-01088-0. [PMID: 39198708 DOI: 10.1038/s41579-024-01088-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2024] [Indexed: 09/01/2024]
Abstract
The bacterial envelope is one of the oldest and most essential cellular components and has been traditionally divided into Gram-positive (monoderm) and Gram-negative (diderm). Recent landmark studies have challenged a major paradigm in microbiology by inferring that the last bacterial common ancestor had a diderm envelope and that the outer membrane (OM) was lost repeatedly in evolution to give rise to monoderms. Intriguingly, OM losses appear to have occurred exclusively in the Terrabacteria, one of the two major clades of bacteria. In this Review, we present current knowledge about the Terrabacteria. We describe their diversity and phylogeny and then highlight the vast phenotypic diversity of the Terrabacteria cell envelopes, which display large deviations from the textbook examples of diderms and monoderms, challenging the classical Gram-positive-Gram-negative divide. We highlight the striking differences in the systems involved in OM biogenesis in Terrabacteria with respect to the classical diderm experimental models and how they provide novel insights into the diversity and biogenesis of the bacterial cell envelope. We also discuss the potential evolutionary steps that might have led to the multiple losses of the OM and speculate on how the very first OM might have emerged before the last bacterial common ancestor.
Collapse
Affiliation(s)
- Basile Beaud Benyahia
- Evolutionary Biology of the Microbial Cell Laboratory, Institut Pasteur, Université Paris Cité, Paris, France
| | - Najwa Taib
- Evolutionary Biology of the Microbial Cell Laboratory, Institut Pasteur, Université Paris Cité, Paris, France
- Bioinformatics and Biostatistics Hub, Institut Pasteur, Université Paris Cité, Paris, France
| | - Christophe Beloin
- Genetics of Biofilms Laboratory, Institut Pasteur, Université Paris Cité, Paris, France
| | - Simonetta Gribaldo
- Evolutionary Biology of the Microbial Cell Laboratory, Institut Pasteur, Université Paris Cité, Paris, France.
| |
Collapse
|
3
|
Peng M, Zhao C, Lu F, Zhang X, Wang X, He L, Chen B. Role of Nedd4L in Macrophage Pro-Inflammatory Polarization Induced by Influenza A Virus and Lipopolysaccharide Stimulation. Microorganisms 2024; 12:1291. [PMID: 39065060 PMCID: PMC11279021 DOI: 10.3390/microorganisms12071291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 07/28/2024] Open
Abstract
Influenza A virus (IAV) infection often leads to influenza-associated fatalities, frequently compounded by subsequent bacterial infections, particularly Gram-negative bacterial co-infections. Lipopolysaccharide (LPS), a primary virulence factor in Gram-negative bacteria, plays a crucial role in influenza-bacterial co-infections. However, the precise pathogenic mechanisms underlying the synergistic effects of viral-bacterial co-infections remain elusive, posing significant challenges for disease management. In our study, we administered a combination of IAV and LPS to mice and examined associated parameters, including the lung function, lung index, wet/dry ratio, serum inflammatory cytokines, Nedd4L expression in lung tissue, and mRNA levels of inflammatory cytokines. Co-infection with IAV and LPS exacerbated lung tissue inflammation and amplified M1 macrophage expression in lung tissue. Additionally, we stimulated macrophages with IAV and LPS in vitro, assessing the inflammatory cytokine content in the cell supernatant and cytokine mRNA expression within the cells. This combined stimulation intensified the inflammatory response in macrophages and upregulated Nedd4L protein and mRNA expression. Subsequently, we used siRNA to knockdown Nedd4L in macrophages, revealing that suppression of Nedd4L expression alleviated the inflammatory response triggered by concurrent IAV and LPS stimulation. Collectively, these results highlight the pivotal role of Nedd4L in mediating the exacerbated inflammatory responses observed in IAV and LPS co-infections.
Collapse
Affiliation(s)
- Meihong Peng
- Medical School, Hunan University of Chinese Medicine, Changsha 410208, China; (M.P.); (L.H.); (B.C.)
| | - Cheng Zhao
- School of Integrated Chinese and Western Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (C.Z.); (X.Z.); (X.W.)
| | - Fangguo Lu
- Medical School, Hunan University of Chinese Medicine, Changsha 410208, China; (M.P.); (L.H.); (B.C.)
- School of Integrated Chinese and Western Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (C.Z.); (X.Z.); (X.W.)
| | - Xianggang Zhang
- School of Integrated Chinese and Western Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (C.Z.); (X.Z.); (X.W.)
| | - Xiaoqi Wang
- School of Integrated Chinese and Western Medicine, Hunan University of Chinese Medicine, Changsha 410208, China; (C.Z.); (X.Z.); (X.W.)
| | - Li He
- Medical School, Hunan University of Chinese Medicine, Changsha 410208, China; (M.P.); (L.H.); (B.C.)
| | - Bei Chen
- Medical School, Hunan University of Chinese Medicine, Changsha 410208, China; (M.P.); (L.H.); (B.C.)
| |
Collapse
|
4
|
Padhy I, Dwibedy SK, Mohapatra SS. A molecular overview of the polymyxin-LPS interaction in the context of its mode of action and resistance development. Microbiol Res 2024; 283:127679. [PMID: 38508087 DOI: 10.1016/j.micres.2024.127679] [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: 07/31/2023] [Revised: 03/03/2024] [Accepted: 03/06/2024] [Indexed: 03/22/2024]
Abstract
With the rising incidences of antimicrobial resistance (AMR) and the diminishing options of novel antimicrobial agents, it is paramount to decipher the molecular mechanisms of action and the emergence of resistance to the existing drugs. Polymyxin, a cationic antimicrobial lipopeptide, is used to treat infections by Gram-negative bacterial pathogens as a last option. Though polymyxins were identified almost seventy years back, their use has been restricted owing to toxicity issues in humans. However, their clinical use has been increasing in recent times resulting in the rise of polymyxin resistance. Moreover, the detection of "mobile colistin resistance (mcr)" genes in the environment and their spread across the globe have complicated the scenario. The mechanism of polymyxin action and the development of resistance is not thoroughly understood. Specifically, the polymyxin-bacterial lipopolysaccharide (LPS) interaction is a challenging area of investigation. The use of advanced biophysical techniques and improvement in molecular dynamics simulation approaches have furthered our understanding of this interaction, which will help develop polymyxin analogs with better bactericidal effects and lesser toxicity in the future. In this review, we have delved deeper into the mechanisms of polymyxin-LPS interactions, highlighting several models proposed, and the mechanisms of polymyxin resistance development in some of the most critical Gram-negative pathogens.
Collapse
Affiliation(s)
- Indira Padhy
- Molecular Microbiology Lab, Department of Biotechnology, Berhampur University, Bhanja Bihar, Berhampur 760007, Odisha, India
| | - Sambit K Dwibedy
- Molecular Microbiology Lab, Department of Biotechnology, Berhampur University, Bhanja Bihar, Berhampur 760007, Odisha, India
| | - Saswat S Mohapatra
- Molecular Microbiology Lab, Department of Biotechnology, Berhampur University, Bhanja Bihar, Berhampur 760007, Odisha, India.
| |
Collapse
|
5
|
Chen Z, Wang L, He D, Liu Q, Han Q, Zhang J, Zhang AM, Song Y. Exploration of the Antibacterial and Anti-Inflammatory Activity of a Novel Antimicrobial Peptide Brevinin-1BW. Molecules 2024; 29:1534. [PMID: 38611812 PMCID: PMC11013252 DOI: 10.3390/molecules29071534] [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: 02/20/2024] [Revised: 03/25/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024] Open
Abstract
Antibiotic resistance has emerged as a grave threat to global public health, leading to an increasing number of treatment failures. Antimicrobial peptides (AMPs) are widely regarded as potential substitutes for traditional antibiotics since they are less likely to induce resistance when used. A novel AMP named Brevinin-1BW (FLPLLAGLAASFLPTIFCKISRKC) was obtained by the Research Center of Molecular Medicine of Yunnan Province from the skin of the Pelophylax nigromaculatus. Brevinia-1BW had effective inhibitory effects on Gram-positive bacteria, with a minimum inhibitory concentration (MIC) of 3.125 μg/mL against Enterococcus faecalis (ATCC 29212) and 6.25 μg/mL against both Staphylococcus aureus (ATCC 25923) and multidrug-resistant Staphylococcus aureus (ATCC 29213) but had weaker inhibitory effects on Gram-negative bacteria, with a MIC of ≥100 μg/mL. Studies using scanning electron microscopy (SEM) and flow cytometry have revealed that it exerts its antibacterial activity by disrupting bacterial membranes. Additionally, it possesses strong biofilm inhibitory and eradication activities as well as significant lipopolysaccharide (LPS)-binding activity. Furthermore, Brevinin-1BW has shown a significant anti-inflammatory effect in LPS-treated RAW264.7 cells. In conclusion, Brevinin-1BW is anticipated to be a promising clinical agent with potent anti-Gram-positive bacterial and anti-inflammatory properties.
Collapse
Affiliation(s)
- Zhizhi Chen
- Research Center of Molecular Medicine of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650504, China; (Z.C.); (L.W.); (D.H.); (Q.L.); (Q.H.); (J.Z.); (A.-M.Z.)
| | - Lei Wang
- Research Center of Molecular Medicine of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650504, China; (Z.C.); (L.W.); (D.H.); (Q.L.); (Q.H.); (J.Z.); (A.-M.Z.)
| | - Dongxia He
- Research Center of Molecular Medicine of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650504, China; (Z.C.); (L.W.); (D.H.); (Q.L.); (Q.H.); (J.Z.); (A.-M.Z.)
| | - Qi Liu
- Research Center of Molecular Medicine of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650504, China; (Z.C.); (L.W.); (D.H.); (Q.L.); (Q.H.); (J.Z.); (A.-M.Z.)
| | - Qinqin Han
- Research Center of Molecular Medicine of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650504, China; (Z.C.); (L.W.); (D.H.); (Q.L.); (Q.H.); (J.Z.); (A.-M.Z.)
| | - Jinyang Zhang
- Research Center of Molecular Medicine of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650504, China; (Z.C.); (L.W.); (D.H.); (Q.L.); (Q.H.); (J.Z.); (A.-M.Z.)
| | - A-Mei Zhang
- Research Center of Molecular Medicine of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650504, China; (Z.C.); (L.W.); (D.H.); (Q.L.); (Q.H.); (J.Z.); (A.-M.Z.)
| | - Yuzhu Song
- Research Center of Molecular Medicine of Yunnan Province, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650504, China; (Z.C.); (L.W.); (D.H.); (Q.L.); (Q.H.); (J.Z.); (A.-M.Z.)
- School of Medicine, Kunming University of Science and Technology, Kunming 650504, China
| |
Collapse
|
6
|
Baijal K, Abramchuk I, Herrera CM, Mah TF, Trent MS, Lavallée-Adam M, Downey M. Polyphosphate kinase regulates LPS structure and polymyxin resistance during starvation in E. coli. PLoS Biol 2024; 22:e3002558. [PMID: 38478588 PMCID: PMC10962826 DOI: 10.1371/journal.pbio.3002558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 03/25/2024] [Accepted: 02/21/2024] [Indexed: 03/26/2024] Open
Abstract
Polyphosphates (polyP) are chains of inorganic phosphates that can reach over 1,000 residues in length. In Escherichia coli, polyP is produced by the polyP kinase (PPK) and is thought to play a protective role during the response to cellular stress. However, the molecular pathways impacted by PPK activity and polyP accumulation remain poorly characterized. In this work, we used label-free mass spectrometry to study the response of bacteria that cannot produce polyP (Δppk) during starvation to identify novel pathways regulated by PPK. In response to starvation, we found 92 proteins significantly differentially expressed between wild-type and Δppk mutant cells. Wild-type cells were enriched for proteins related to amino acid biosynthesis and transport, while Δppk mutants were enriched for proteins related to translation and ribosome biogenesis, suggesting that without PPK, cells remain inappropriately primed for growth even in the absence of the required building blocks. From our data set, we were particularly interested in Arn and EptA proteins, which were down-regulated in Δppk mutants compared to wild-type controls, because they play a role in lipid A modifications linked to polymyxin resistance. Using western blotting, we confirm differential expression of these and related proteins in K-12 strains and a uropathogenic isolate, and provide evidence that this mis-regulation in Δppk cells stems from a failure to induce the BasRS two-component system during starvation. We also show that Δppk mutants unable to up-regulate Arn and EptA expression lack the respective L-Ara4N and pEtN modifications on lipid A. In line with this observation, loss of ppk restores polymyxin sensitivity in resistant strains carrying a constitutively active basR allele. Overall, we show a new role for PPK in lipid A modification during starvation and provide a rationale for targeting PPK to sensitize bacteria towards polymyxin treatment. We further anticipate that our proteomics work will provide an important resource for researchers interested in the diverse pathways impacted by PPK.
Collapse
Affiliation(s)
- Kanchi Baijal
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Cellular & Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Iryna Abramchuk
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Carmen M. Herrera
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
| | - Thien-Fah Mah
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, Ontario, Canada
| | - M. Stephen Trent
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
| | - Mathieu Lavallée-Adam
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Michael Downey
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Cellular & Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| |
Collapse
|
7
|
Gómez Borrego J, Torrent Burgas M. Structural assembly of the bacterial essential interactome. eLife 2024; 13:e94919. [PMID: 38226900 PMCID: PMC10863985 DOI: 10.7554/elife.94919] [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: 11/30/2023] [Accepted: 12/22/2023] [Indexed: 01/17/2024] Open
Abstract
The study of protein interactions in living organisms is fundamental for understanding biological processes and central metabolic pathways. Yet, our knowledge of the bacterial interactome remains limited. Here, we combined gene deletion mutant analysis with deep-learning protein folding using AlphaFold2 to predict the core bacterial essential interactome. We predicted and modeled 1402 interactions between essential proteins in bacteria and generated 146 high-accuracy models. Our analysis reveals previously unknown details about the assembly mechanisms of these complexes, highlighting the importance of specific structural features in their stability and function. Our work provides a framework for predicting the essential interactomes of bacteria and highlight the potential of deep-learning algorithms in advancing our understanding of the complex biology of living organisms. Also, the results presented here offer a promising approach to identify novel antibiotic targets.
Collapse
Affiliation(s)
- Jordi Gómez Borrego
- Systems Biology of Infection Lab, Department of Biochemistry and Molecular Biology, Biosciences Faculty, Universitat Autònoma de BarcelonaCerdanyola del VallèsSpain
| | - Marc Torrent Burgas
- Systems Biology of Infection Lab, Department of Biochemistry and Molecular Biology, Biosciences Faculty, Universitat Autònoma de BarcelonaCerdanyola del VallèsSpain
| |
Collapse
|
8
|
Zhang W, Liu S, Kong L, Wu S, Zhong Z, Yu L, Yang Q, Zhang J, Li J, Zheng G. Lipopolysaccharide-induced persistent inflammation ameliorates fat accumulation by promoting adipose browning in vitro and in vivo. Int J Biol Macromol 2023; 252:126511. [PMID: 37625745 DOI: 10.1016/j.ijbiomac.2023.126511] [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: 04/13/2023] [Revised: 07/16/2023] [Accepted: 08/23/2023] [Indexed: 08/27/2023]
Abstract
This work aimed to explore whether the persistent inflammation induced by lipopolysaccharide (LPS) ameliorates fat accumulation by promoting adipose browning in vitro and in vivo. LPS over 1 ng/mL reduced lipid accumulation while increasing the expressions of specific genes involved in inflammation, mitochondrial biogenesis, and adipose browning in 3T3-L1 adipocytes. Moreover, LPS in intraperitoneal injection decreased white adipose tissue weight and elevated interscapular brown adipose tissue weight in mice. According to RT-PCR and western blot analysis results, the expressions of genes and proteins related to inflammation, mitochondrial biogenesis, lipolysis, and brown or beige markers in different tissues were elevated after LPS intervention. Cumulatively, LPS-induced persistent inflammation may potentially ameliorate fat accumulation by facilitating adipose browning in 3T3-L1 adipocytes and mice. These results offer new perspectives into the effect of persistent inflammation induced by LPS on regulating fat metabolism, thereby reducing fat accumulation by boosting adipose browning procedure.
Collapse
Affiliation(s)
- Wenkai Zhang
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Shanshan Liu
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Li Kong
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Shaofu Wu
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Zhen Zhong
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Longhui Yu
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Qinru Yang
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Jinfeng Zhang
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Jingen Li
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China.
| | - Guodong Zheng
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China.
| |
Collapse
|
9
|
Baijal K, Abramchuk I, Herrera CM, Stephen Trent M, Lavallée-Adam M, Downey M. Proteomics analysis reveals a role for E. coli polyphosphate kinase in membrane structure and polymyxin resistance during starvation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.06.546892. [PMID: 37461725 PMCID: PMC10350021 DOI: 10.1101/2023.07.06.546892] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Polyphosphates (polyP) are chains of inorganic phosphates that can reach over 1000 residues in length. In Escherichia coli, polyP is produced by the polyP kinase (PPK) and is thought to play a protective role during the response to cellular stress. However, the molecular pathways impacted by PPK activity and polyP accumulation remain poorly characterized. In this work we used label-free mass spectrometry to study the response of bacteria that cannot produce polyP (∆ppk) during starvation to identify novel pathways regulated by PPK. In response to starvation, we found 92 proteins significantly differentially expressed between wild-type and ∆ppk mutant cells. Wild-type cells were enriched for proteins related to amino acid biosynthesis and transport, while Δppk mutants were enriched for proteins related to translation and ribosome biogenesis, suggesting that without PPK, cells remain inappropriately primed for growth even in the absence of required building blocks. From our dataset, we were particularly interested in Arn and EptA proteins, which were downregulated in ∆ppk mutants compared to wild-type controls, because they play a role in lipid A modifications linked to polymyxin resistance. Using western blotting, we confirm differential expression of these and related proteins, and provide evidence that this mis-regulation in ∆ppk cells stems from a failure to induce the BasS/BasR two-component system during starvation. We also show that ∆ppk mutants unable to upregulate Arn and EptA expression lack the respective L-Ara4N and pEtN modifications on lipid A. In line with this observation, loss of ppk restores polymyxin sensitivity in resistant strains carrying a constitutively active basR allele. Overall, we show a new role for PPK in lipid A modification during starvation and provide a rationale for targeting PPK to sensitize bacteria towards polymyxin treatment. We further anticipate that our proteomics work will provide an important resource for researchers interested in the diverse pathways impacted by PPK.
Collapse
Affiliation(s)
- Kanchi Baijal
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Cellular & Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Iryna Abramchuk
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Carmen M. Herrera
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - M. Stephen Trent
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Mathieu Lavallée-Adam
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Michael Downey
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Cellular & Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| |
Collapse
|
10
|
He H, Pramanik AS, Swanson SK, Johnson DK, Florens L, Zückert WR. A Borrelia burgdorferi LptD homolog is required for flipping of surface lipoproteins through the spirochetal outer membrane. Mol Microbiol 2023; 119:752-767. [PMID: 37170643 PMCID: PMC10330739 DOI: 10.1111/mmi.15072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/13/2023]
Abstract
Borrelia spirochetes are unique among diderm bacteria in their lack of lipopolysaccharide (LPS) in the outer membrane (OM) and their abundance of surface-exposed lipoproteins with major roles in transmission, virulence, and pathogenesis. Despite their importance, little is known about how surface lipoproteins are translocated through the periplasm and the OM. Here, we characterized Borrelia burgdorferi BB0838, a distant homolog of the OM LPS assembly protein LptD. Using a CRISPR interference approach, we showed that BB0838 is required for cell growth and envelope stability. Upon BB0838 knockdown, surface lipoprotein OspA was retained in the inner leaflet of the OM, as determined by its inaccessibility to in situ proteolysis but its presence in OM vesicles. The topology of the OM porin/adhesin P66 remained unaffected. Quantitative mass spectrometry of the B. burgdorferi membrane-associated proteome confirmed the selective periplasmic retention of surface lipoproteins under BB0838 knockdown conditions. Additional analysis identified a single in situ protease-accessible BB0838 peptide that mapped to a predicted β-barrel surface loop. Alphafold Multimer modeled a B. burgdorferi LptB2 FGCAD complex spanning the periplasm. Together, this suggests that BB0838/LptDBb facilitates the essential terminal step in spirochetal surface lipoprotein secretion, using an orthologous OM component of a pathway that secretes LPS in proteobacteria.
Collapse
Affiliation(s)
- Huan He
- University of Kansas School of Medicine, Department of Microbiology, Molecular Genetics and Immunology, Kansas City, Kansas, USA
| | - Ankita S. Pramanik
- University of Kansas School of Medicine, Department of Microbiology, Molecular Genetics and Immunology, Kansas City, Kansas, USA
| | | | - David K. Johnson
- University of Kansas, Computational Chemical Biology Core, Lawrence, Kansas, USA
| | - Laurence Florens
- Stowers Institute for Medical Research, Kansas City, Missouri, USA
| | - Wolfram R. Zückert
- University of Kansas School of Medicine, Department of Microbiology, Molecular Genetics and Immunology, Kansas City, Kansas, USA
| |
Collapse
|
11
|
Suppressor Mutations in LptF Bypass Essentiality of LptC by Forming a Six-Protein Transenvelope Bridge That Efficiently Transports Lipopolysaccharide. mBio 2023; 14:e0220222. [PMID: 36541759 PMCID: PMC9972910 DOI: 10.1128/mbio.02202-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Lipopolysaccharide (LPS) is an essential component of the outer membrane (OM) of many Gram-negative bacteria, providing a barrier against the entry of toxic molecules. In Escherichia coli, LPS is exported to the cell surface by seven essential proteins (LptA-G) that form a transenvelope complex. At the inner membrane, the ATP-binding cassette (ABC) transporter LptB2FG associates with LptC to power LPS extraction from the membrane and transfer to the periplasmic LptA protein, which is in complex with the OM translocon LptDE. LptC interacts both with LptB2FG and LptADE to mediate the formation of the transenvelope bridge and regulates the ATPase activity of LptB2FG. A genetic screen has previously identified suppressor mutants at a residue (R212) of LptF that are viable in the absence of LptC. Here, we present in vivo evidence that the LptF R212G mutant assembles a six-protein transenvelope complex in which LptA mediates interactions with LptF and LptD in the absence of LptC. Furthermore, we present in vitro evidence that the mutant LptB2FG complexes restore the regulation of ATP hydrolysis as it occurs in the LptB2FGC complex to achieve wild-type efficient coupling of ATP hydrolysis and LPS movement. We also show the suppressor mutations restore the wild-type levels of LPS transport both in vivo and in vitro, but remarkably, without restoring the affinity of the inner membrane complex for LptA. Based on the sensitivity of lptF suppressor mutants to selected stress conditions relative to wild-type cells, we show that there are additional regulatory functions of LptF and LptC that had not been identified. IMPORTANCE The presence of an external LPS layer in the outer membrane makes Gram-negative bacteria intrinsically resistant to many antibiotics. Millions of LPS molecules are transported to the cell surface per generation by the Lpt molecular machine made, in E. coli, by seven essential proteins. LptC is the unconventional regulatory subunit of the LptB2FGC ABC transporter, involved in coordinating energy production and LPS transport. Surprisingly, despite being essential for bacterial growth, LptC can be deleted, provided that a specific residue in the periplasmic domain of LptF is mutated and LptA is overexpressed. Here, we apply biochemical techniques to investigate the suppression mechanism. The data produced in this work disclose an unknown regulatory function of LptF in the transporter that not only expands the knowledge about the Lpt complex but can also be targeted by novel LPS biogenesis inhibitors.
Collapse
|
12
|
Sperandeo P, Martorana AM, Zaccaria M, Polissi A. Targeting the LPS export pathway for the development of novel therapeutics. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119406. [PMID: 36473551 DOI: 10.1016/j.bbamcr.2022.119406] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 10/14/2022] [Accepted: 11/01/2022] [Indexed: 12/12/2022]
Abstract
The rapid rise of multi-resistant bacteria is a global health threat. This is especially serious for Gram-negative bacteria in which the impermeable outer membrane (OM) acts as a shield against antibiotics. The development of new drugs with novel modes of actions to combat multi-drug resistant pathogens requires the selection of suitable processes to be targeted. The LPS export pathway is an excellent under exploited target for drug development. Indeed, LPS is the major determinant of the OM permeability barrier, and its biogenetic pathway is conserved in most Gram-negatives. Here we describe efforts to identify inhibitors of the multiprotein Lpt system that transports LPS to the cell surface. Despite none of these molecules has been approved for clinical use, they may represent valuable compounds for optimization. Finally, the recent discovery of a link between inhibition of LPS biogenesis and changes in peptidoglycan structure uncovers additional targets to develop novel therapeutic strategies.
Collapse
Affiliation(s)
- Paola Sperandeo
- Department of Pharmacological and Biomolecular Sciences, Via Balzaretti 9, 20133 Milano, Italy
| | - Alessandra M Martorana
- Department of Pharmacological and Biomolecular Sciences, Via Balzaretti 9, 20133 Milano, Italy
| | - Marta Zaccaria
- Department of Pharmacological and Biomolecular Sciences, Via Balzaretti 9, 20133 Milano, Italy
| | - Alessandra Polissi
- Department of Pharmacological and Biomolecular Sciences, Via Balzaretti 9, 20133 Milano, Italy.
| |
Collapse
|
13
|
Bowen HG, Kenedy MR, Johnson DK, MacKerell AD, Akins DR. Identification of a novel transport system in Borrelia burgdorferi that links the inner and outer membranes. Pathog Dis 2023; 81:ftad014. [PMID: 37385817 PMCID: PMC10353723 DOI: 10.1093/femspd/ftad014] [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: 04/20/2023] [Revised: 06/19/2023] [Accepted: 06/27/2023] [Indexed: 07/01/2023] Open
Abstract
Borrelia burgdorferi, the spirochete that causes Lyme disease, is a diderm organism that is similar to Gram-negative organisms in that it contains both an inner and outer membrane. Unlike typical Gram-negative organisms, however, B. burgdorferi lacks lipopolysaccharide (LPS). Using computational genome analyses and structural modeling, we identified a transport system containing six proteins in B. burgdorferi that are all orthologs to proteins found in the lipopolysaccharide transport (LPT) system that links the inner and outer membranes of Gram-negative organisms and is responsible for placing LPS on the surface of these organisms. While B. burgdorferi does not contain LPS, it does encode over 100 different surface-exposed lipoproteins and several major glycolipids, which like LPS are also highly amphiphilic molecules, though no system to transport these molecules to the borrelial surface is known. Accordingly, experiments supplemented by molecular modeling were undertaken to determine whether the orthologous LPT system identified in B. burgdorferi could transport lipoproteins and/or glycolipids to the borrelial outer membrane. Our combined observations strongly suggest that the LPT transport system does not transport lipoproteins to the surface. Molecular dynamic modeling, however, suggests that the borrelial LPT system could transport borrelial glycolipids to the outer membrane.
Collapse
Affiliation(s)
- Hannah G Bowen
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young Blvd., BMSB 1053 Oklahoma City, OK 73104, United States
| | - Melisha R Kenedy
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young Blvd., BMSB 1053 Oklahoma City, OK 73104, United States
| | - David K Johnson
- Shenkel Structural Biology Center, Molecular Graphics and Modeling Laboratory and the Computational Biology Core, University of Kansas, 2034 Becker Drive Lawrence, Kansas 66047, United States
| | - Alexander D MacKerell
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore 20 North Pine Street Baltimore, Maryland 21201, United States
| | - Darrin R Akins
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young Blvd., BMSB 1053 Oklahoma City, OK 73104, United States
| |
Collapse
|
14
|
Dai X, Yuan M, Lu Y, Zhu X, Liu C, Zheng Y, Si S, Yuan L, Zhang J, Li Y. Identification of a Small Molecule That Inhibits the Interaction of LPS Transporters LptA and LptC. Antibiotics (Basel) 2022; 11:1385. [PMID: 36290043 PMCID: PMC9598311 DOI: 10.3390/antibiotics11101385] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/30/2022] [Accepted: 09/30/2022] [Indexed: 10/15/2023] Open
Abstract
The need for novel antibiotics has become imperative with the increasing prevalence of antibiotic resistance in Gram-negative bacteria in clinics. Acting as a permeability barrier, lipopolysaccharide (LPS) protects Gram-negative bacteria against drugs. LPS is synthesized in cells and transported to the outer membrane (OM) via seven lipopolysaccharide transport (Lpt) proteins (LptA-LptG). Of these seven Lpt proteins, LptC interacts with LptA to transfer LPS from the inner membrane (IM) to the OM, and assembly is aided by LptD/LptE. This interaction among the Lpt proteins is important for the biosynthesis of LPS; therefore, the Lpt proteins, which are significant in the assembly process of LPS, can be a potential target for new antibiotics. In this study, a yeast two-hybrid (Y2H) system was used to screen compounds that could block LPS transport by inhibiting LptA/LptC interaction, which finally disrupts the biosynthesis of the OM. We selected the compound IMB-0042 for this study. Our results suggest that IMB-0042 disrupts LptA/LptC interaction by binding to both LptA and LptC. Escherichia coli cells, when treated with IMB-0042, showed filament morphology, impaired OM integrity, and an accumulation of LPS in the periplasm. IMB-0042 inhibited the growth of Gram-negative bacteria and showed synergistic sensitization to other antibiotics, with low cytotoxicity. Thus, we successfully identified a potential antibacterial agent by using a Y2H system, which blocks the transport of LPS by targeting LptA/LptC interaction in Escherichia coli.
Collapse
Affiliation(s)
- Xiaowei Dai
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
- Hebei Key Laboratory for Chronic Diseases, Tangshan Key Laboratory for Preclinical and Basic Research on Chronic Diseases, School of Basic Medical Sciences, North China University of Science and Technology, Tangshan 063210, China
| | - Min Yuan
- State Key Laboratory for Infectious Diseases Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Yu Lu
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
- Hebei Key Laboratory for Chronic Diseases, Tangshan Key Laboratory for Preclinical and Basic Research on Chronic Diseases, School of Basic Medical Sciences, North China University of Science and Technology, Tangshan 063210, China
| | - Xiaohong Zhu
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Chao Liu
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Yifan Zheng
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Shuyi Si
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Lijie Yuan
- Hebei Key Laboratory for Chronic Diseases, Tangshan Key Laboratory for Preclinical and Basic Research on Chronic Diseases, School of Basic Medical Sciences, North China University of Science and Technology, Tangshan 063210, China
| | - Jing Zhang
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Yan Li
- Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| |
Collapse
|
15
|
Luo M, Chen X, Gao H, Yang F, Chen J, Qiao Y. Bacteria-mediated cancer therapy: A versatile bio-sapper with translational potential. Front Oncol 2022; 12:980111. [PMID: 36276157 PMCID: PMC9585267 DOI: 10.3389/fonc.2022.980111] [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: 06/28/2022] [Accepted: 09/23/2022] [Indexed: 11/13/2022] Open
Abstract
Bacteria are important symbionts for humans, which sustain substantial influences on our health. Interestingly, some bastrains have been identified to have therapeutic applications, notably for antitumor activity. Thereby, oncologists have developed various therapeutic models and investigated the potential antitumor mechanisms for bacteria-mediated cancer therapy (BCT). Even though BCT has a long history and exhibits remarkable therapeutic efficacy in pre-clinical animal models, its clinical translation still lags and requires further breakthroughs. This review aims to focus on the established strains of therapeutic bacteria and their antitumor mechanisms, including the stimulation of host immune responses, direct cytotoxicity, the interference on cellular signal transduction, extracellular matrix remodeling, neoangiogenesis, and metabolism, as well as vehicles for drug delivery and gene therapy. Moreover, a brief discussion is proposed regarding the important future directions for this fantastic research field of BCT at the end of this review.
Collapse
Affiliation(s)
- Miao Luo
- School of Pharmacy, Institute of Hepatology and Metabolic Diseases, Department of Hepatology, the Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou, China
| | - Xiaoyu Chen
- School of Pharmacy, Institute of Hepatology and Metabolic Diseases, Department of Hepatology, the Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou, China
| | - Haojin Gao
- School of Pharmacy, Institute of Hepatology and Metabolic Diseases, Department of Hepatology, the Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou, China
| | - Fan Yang
- School of Pharmacy, Institute of Hepatology and Metabolic Diseases, Department of Hepatology, the Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou, China
| | - Jianxiang Chen
- School of Pharmacy, Institute of Hepatology and Metabolic Diseases, Department of Hepatology, the Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou, China
- *Correspondence: Yiting Qiao, ; Jianxiang Chen,
| | - Yiting Qiao
- School of Pharmacy, Institute of Hepatology and Metabolic Diseases, Department of Hepatology, the Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou, China
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, China
- The First Affiliated Hospital, Key Laboratory of Combined Multi-Organ Transplantation, Ministry of Public Health, Key Laboratory of Organ Transplantation of Zhejiang Province, School of Medicine, Zhejiang University, Hangzhou, China
- *Correspondence: Yiting Qiao, ; Jianxiang Chen,
| |
Collapse
|
16
|
Jia Z, Wang P, Xu Y, Feng G, Wang Q, He X, Song Y, Liu P, Chen J. Trypsin inhibitor LH011 inhibited DSS-induced mice colitis via alleviating inflammation and oxidative stress. Front Pharmacol 2022; 13:986510. [PMID: 36238566 PMCID: PMC9551103 DOI: 10.3389/fphar.2022.986510] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 09/05/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Ulcerative colitis (UC) is one type of inflammatory bowel disease, characterized by inflammation with infiltration and activation of macrophages in colonic tissue. LH011 is a trypsin inhibitor with potential anti-inflammatory effect. Purpose: Here, we aim to assay the effects of LH011 on UC and further investigate the potential mechanisms in vitro and in vivo. Methods: Dextran sulfate sodium (DSS, 3.5%, w/v) was used to induce UC, and lipopolysaccharide (LPS) was used to induce inflammation in RAW 264.7 cells. LH011 was administrated to mice in vivo or to RAW 264.7 cells in vitro at different concentrations. The cytokines (IL-1β, IL-6, and TNF-α) and the changes of NF-κB and Nrf2 pathways were detected. Results: The results showed that LH011 improved DSS-induced mice colitis, including loss of weight, disease activity index (DAI), and colonic pathological damage. In addition, LH011 inhibited the expressions of IL-1β, IL-6, and TNF-α and strengthened the anti-oxidative capacity. Mechanically, LH011 downregulated the nuclear localization of NF-κB p65 and upregulated the protein expression of Nrf2. Conclusion: These results demonstrated that LH011 alleviated inflammation and oxidative stress during UC by inhibiting TLR4/NF-κB and activating Nrf2/Keap1/HO-1 signaling pathways.
Collapse
Affiliation(s)
- Zhenmao Jia
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Panxia Wang
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
- School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou, China
| | | | - Guodong Feng
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Quan Wang
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Xiangjun He
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yan Song
- Guangzhou Link Health Group, Guangzhou, China
- *Correspondence: Yan Song, ; Peiqing Liu, ; Jianwen Chen,
| | - Peiqing Liu
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
- Department of National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
- *Correspondence: Yan Song, ; Peiqing Liu, ; Jianwen Chen,
| | - Jianwen Chen
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
- Department of National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangzhou, China
- *Correspondence: Yan Song, ; Peiqing Liu, ; Jianwen Chen,
| |
Collapse
|
17
|
Yue B, Zong G, Tao R, Wei Z, Lu Y. Crosstalk between traditional Chinese medicine-derived polysaccharides and the gut microbiota: A new perspective to understand traditional Chinese medicine. Phytother Res 2022; 36:4125-4138. [PMID: 36100366 DOI: 10.1002/ptr.7607] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 08/04/2022] [Accepted: 08/20/2022] [Indexed: 11/09/2022]
Abstract
Polysaccharide is a kind of macromolecule polymer composed of monosaccharides connected by glycosidic bonds. Traditional Chinese medicine (TCM), composed of various bioactive ingredients, is usually rich in polysaccharides. In recent years, extensive research on TCM polysaccharides has demonstrated their pharmacological effects. Polysaccharides can hardly be catabolized by enzymes encoded by the human genome but can be degraded to absorbable metabolites by bacteria inhabiting the colon. Hence, the gut microbiota plays a vital role in degrading TCM polysaccharides into short-chain fatty acids (SCFAs) which exert physiological functions locally and systemically. Besides, TCM polysaccharides can also modulate the composition and activities of the gut microbiota by promoting the growth of beneficial bacteria and inhibiting the colonization of pathogenic bacteria, ultimately restoring gut homeostasis and improving human health. In this review, we discuss the extraction and pharmacological effects of TCM polysaccharides, various functions of the gut microbiota, and the interactions between TCM polysaccharides and the gut microbiota, illuminating the mechanisms of TCM polysaccharides modulating host physiology via the gut microbiota. To firmly establish the clinical efficacy of TCM polysaccharides, further high-quality studies especially clinical trials are needed. Generally, discussion on the interplay between TCM polysaccharides and the gut microbiota is expected to elucidate their application prospects and inspire new thoughts in the development of TCM.
Collapse
Affiliation(s)
- Bingjie Yue
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Gangfan Zong
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Ruizhi Tao
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Zhonghong Wei
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China.,Jiangsu Joint International Research Laboratory of Chinese Medicine and Regenerative Medicine, Nanjing, China
| | - Yin Lu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China.,Jiangsu Joint International Research Laboratory of Chinese Medicine and Regenerative Medicine, Nanjing, China.,Jiangsu Collaborative Innovation Center of Traditional Chinese Medicine (TCM) Prevention and Treatment of Tumor, Nanjing University of Chinese Medicine, Nanjing, China
| |
Collapse
|
18
|
Chen L, Liu Q, Zhao X, Zhang H, Pang X, Yang H. Inactivation efficacies of lactic acid and mild heat treatments against Escherichia coli strains in organic broccoli sprouts. Food Control 2022. [DOI: 10.1016/j.foodcont.2021.108577] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
19
|
Monjarás Feria J, Valvano MA. Exploring the Topology of Cytoplasmic Membrane Proteins Involved in Lipopolysaccharide Biosynthesis by in Silico and Biochemical Analyses. Methods Mol Biol 2022; 2548:71-82. [PMID: 36151492 DOI: 10.1007/978-1-0716-2581-1_5] [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] [Indexed: 06/16/2023]
Abstract
In the absence of a tri-dimensional structure, revealing the topology of a membrane protein provides relevant information to identify the number and orientation of transmembrane helices and the localization of critical amino acid residues, contributing to a better understanding of function and intermolecular associations. Topology can be predicted in silico by bioinformatic analysis or solved by biochemical methods. In this chapter, we describe a pipeline employing bioinformatic approaches for the prediction of membrane protein topology, followed by experimental validation through the substituted-cysteine accessibility method and the analysis of the protein's oligomerization state.
Collapse
Affiliation(s)
- Julia Monjarás Feria
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Miguel A Valvano
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK.
| |
Collapse
|
20
|
ElyC and Cyclic Enterobacterial Common Antigen Regulate Synthesis of Phosphoglyceride-Linked Enterobacterial Common Antigen. mBio 2021; 12:e0284621. [PMID: 34809459 PMCID: PMC8609368 DOI: 10.1128/mbio.02846-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The Gram-negative cell envelope is a complex structure delineating the cell from its environment. Recently, we found that enterobacterial common antigen (ECA) plays a role maintaining the outer membrane (OM) permeability barrier, which excludes toxic molecules including many antibiotics. ECA is a conserved carbohydrate found throughout Enterobacterales (e.g., Salmonella, Klebsiella, and Yersinia). There are two OM forms of ECA (phosphoglyceride-linked ECAPG and lipopolysaccharide-linked ECALPS) and one periplasmic form of ECA (cyclic ECACYC). ECAPG, found in the outer leaflet of the OM, consists of a linear ECA oligomer attached to phosphoglyceride through a phosphodiester linkage. The process through which ECAPG is produced from polymerized ECA is unknown. Therefore, we set out to identify genes interacting genetically with ECAPG biosynthesis in Escherichia coli K-12 using the competition between ECA and peptidoglycan biosynthesis. Through transposon-directed insertion sequencing, we identified an interaction between elyC and ECAPG biosynthesis. ElyC is an inner membrane protein previously shown to alter peptidoglycan biosynthesis rates. We found ΔelyC was lethal specifically in strains producing ECAPG without other ECA forms, suggesting ECAPG biosynthesis impairment or dysregulation. Further characterization suggested ElyC inhibits ECAPG synthesis in a posttranscriptional manner. Moreover, the full impact of ElyC on ECA levels requires the presence of ECACYC. Our data demonstrate ECACYC can regulate ECAPG synthesis in strains wild type for elyC. Overall, our data demonstrate ElyC and ECACYC act in a novel pathway that regulates the production of ECAPG, supporting a model in which ElyC provides feedback regulation of ECAPG production based on the periplasmic levels of ECACYC.
Collapse
|
21
|
Pérez-Ortega J, Van Harten RM, Van Boxtel R, Plisnier M, Louckx M, Ingels D, Haagsman HP, Tommassen J. Reduction of endotoxicity in Bordetella bronchiseptica by lipid A engineering: Characterization of lpxL1 and pagP mutants. Virulence 2021; 12:1452-1468. [PMID: 34053396 PMCID: PMC8168481 DOI: 10.1080/21505594.2021.1929037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 02/28/2021] [Accepted: 05/07/2021] [Indexed: 11/22/2022] Open
Abstract
Whole-cell vaccines against Gram-negative bacteria commonly display high reactogenicity caused by the endotoxic activity of lipopolysaccharide (LPS), one of the major components of the bacterial outer membrane. Underacylation of the lipid A moiety of LPS has been related with reduced endotoxicity in several Gram-negative species. Here, we evaluated whether the inactivation of two genes encoding lipid A acylases of Bordetella bronchiseptica, i.e. pagP and lpxL1, could be used for the development of less reactogenic vaccines against this pathogen for livestock and companion animals. Inactivation of pagP resulted in the loss of the secondary palmitate chain at position 3' of lipid A, but hardly affected the potency of the LPS to activate the Toll-like receptor 4 (TLR4). Inactivation of lpxL1 resulted in the loss of the secondary 2-hydroxy laurate group present at position 2 of lipid A and, unexpectedly, in the additional loss of the glucosamines that decorate the phosphate groups at positions 1 and 4' and in an increase in LPS molecules carrying O-antigen. The resulting LPS showed greatly reduced potency to activate TLR4 in HEK-Blue reporter cells expressing human or mouse TLR4 as well as in porcine macrophages. Characterization of the lpxL1 mutant revealed many pleiotropic phenotypes, including increased resistance to SDS and rifampicin, increased susceptibility to cationic antimicrobial peptides, decreased auto-aggregation and biofilm formation, and a tendency to decreased infectivity of macrophages, which are all related to the altered LPS structure. We suggest that the lpxL1 mutant will be useful for the generation of safer vaccines.
Collapse
Affiliation(s)
- Jesús Pérez-Ortega
- Section Molecular Microbiology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
- Institute of Biomembranes, Utrecht University, Utrecht, Netherlands
| | - Roel M. Van Harten
- Section of Molecular Host Defense, Division of Infectious Diseases and Immunology, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Ria Van Boxtel
- Section Molecular Microbiology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | | | | | | | - Henk P. Haagsman
- Section of Molecular Host Defense, Division of Infectious Diseases and Immunology, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Jan Tommassen
- Section Molecular Microbiology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
- Institute of Biomembranes, Utrecht University, Utrecht, Netherlands
| |
Collapse
|
22
|
Lin Y, Lin T, Cheng N, Wu S, Huang J, Chen X, Chen T, Zhou M, Wang L, Shaw C. Evaluation of antimicrobial and anticancer activities of three peptides identified from the skin secretion of Hylarana latouchii. Acta Biochim Biophys Sin (Shanghai) 2021; 53:1469-1483. [PMID: 34508563 DOI: 10.1093/abbs/gmab126] [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: 02/23/2021] [Indexed: 12/22/2022] Open
Abstract
The skins of frogs of the family Ranidae are particularly rich sources of biologically active peptides, among which antimicrobial peptides (AMPs) constitute the major portion. Some of these have attracted the interest of researchers because they possess both antimicrobial and anticancer activities. In this study, with 'shotgun' cloning and MS/MS fragmentation, three AMPs, homologues of family brevinin-1 (brevinin-1HL), and temporin (temporin-HLa and temporin-HLb), were discovered from the skin secretion of the broad-folded frog, Hylarana latouchii. They exhibited various degrees of antimicrobial and antibiofilm activities against test microorganisms and hemolysis on horse erythrocytes. It was found that they could induce bacteria death through disrupting cell membranes and binding to bacterial DNA. In addition, they also showed different potencies towards human cancer cell lines. The secondary structure and physicochemical properties of each peptide were investigated to preliminarily reveal their structure-activity relationships. Circular dichroism spectrometry showed that they all adopted a canonical α-helical conformation in membrane-mimetic solvents. Notably, the prepropeptide of brevinin-1HL from H. latouchii was highly identical to that of brevinin-1GHd from Hylarana guentheri, indicating a close relationship between these two species. Accordingly, this study provides candidates for the design of novel anti-infective and antineoplastic agents to fight multidrug-resistant bacteria and malignant tumors and also offers additional clues for the taxonomy of ranid frogs.
Collapse
Affiliation(s)
- Yan Lin
- College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Natural Drug Discovery Group, School of Pharmacy, Queen’s University, Belfast BT9 7BL, UK
| | - Tianxing Lin
- College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Ningna Cheng
- College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shuting Wu
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Jiancai Huang
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Xiaoling Chen
- Natural Drug Discovery Group, School of Pharmacy, Queen’s University, Belfast BT9 7BL, UK
| | - Tianbao Chen
- Natural Drug Discovery Group, School of Pharmacy, Queen’s University, Belfast BT9 7BL, UK
| | - Mei Zhou
- Natural Drug Discovery Group, School of Pharmacy, Queen’s University, Belfast BT9 7BL, UK
| | - Lei Wang
- Natural Drug Discovery Group, School of Pharmacy, Queen’s University, Belfast BT9 7BL, UK
| | - Chris Shaw
- Natural Drug Discovery Group, School of Pharmacy, Queen’s University, Belfast BT9 7BL, UK
| |
Collapse
|
23
|
Zheng M, Zheng M, Epstein S, Harnagel AP, Kim H, Lupoli TJ. Chemical Biology Tools for Modulating and Visualizing Gram-Negative Bacterial Surface Polysaccharides. ACS Chem Biol 2021; 16:1841-1865. [PMID: 34569792 DOI: 10.1021/acschembio.1c00341] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bacterial cells present a wide diversity of saccharides that decorate the cell surface and help mediate interactions with the environment. Many Gram-negative cells express O-antigens, which are long sugar polymers that makeup the distal portion of lipopolysaccharide (LPS) that constitutes the surface of the outer membrane. This review highlights chemical biology tools that have been developed in recent years to facilitate the modulation of O-antigen synthesis and composition, as well as related bacterial polysaccharide pathways, and the detection of unique glycan sequences. Advances in the biochemistry and structural biology of O-antigen biosynthetic machinery are also described, which provide guidance for the design of novel chemical and biomolecular probes. Many of the tools noted here have not yet been utilized in biological systems and offer researchers the opportunity to investigate the complex sugar architecture of Gram-negative cells.
Collapse
Affiliation(s)
- Meng Zheng
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Maggie Zheng
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Samuel Epstein
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Alexa P. Harnagel
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Hanee Kim
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Tania J. Lupoli
- Department of Chemistry, New York University, New York, 10003 New York, United States
| |
Collapse
|
24
|
Di Lorenzo F, Duda KA, Lanzetta R, Silipo A, De Castro C, Molinaro A. A Journey from Structure to Function of Bacterial Lipopolysaccharides. Chem Rev 2021; 122:15767-15821. [PMID: 34286971 DOI: 10.1021/acs.chemrev.0c01321] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Lipopolysaccharide (LPS) is a crucial constituent of the outer membrane of most Gram-negative bacteria, playing a fundamental role in the protection of bacteria from environmental stress factors, in drug resistance, in pathogenesis, and in symbiosis. During the last decades, LPS has been thoroughly dissected, and massive information on this fascinating biomolecule is now available. In this Review, we will give the reader a third millennium update of the current knowledge of LPS with key information on the inherent peculiar carbohydrate chemistry due to often puzzling sugar residues that are uniquely found on it. Then, we will drive the reader through the complex and multifarious immunological outcomes that any given LPS can raise, which is strictly dependent on its chemical structure. Further, we will argue about issues that still remain unresolved and that would represent the immediate future of LPS research. It is critical to address these points to complete our notions on LPS chemistry, functions, and roles, in turn leading to innovative ways to manipulate the processes involving such a still controversial and intriguing biomolecule.
Collapse
Affiliation(s)
- Flaviana Di Lorenzo
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy.,Task Force on Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy
| | - Katarzyna A Duda
- Research Center Borstel Leibniz Lung Center, Parkallee 4a, 23845 Borstel, Germany
| | - Rosa Lanzetta
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy
| | - Alba Silipo
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy.,Task Force on Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy
| | - Cristina De Castro
- Task Force on Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy.,Department of Agricultural Sciences, University of Naples Federico II, Via Università 96, 80055 Portici, Naples, Italy
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy.,Task Force on Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy.,Department of Chemistry, School of Science, Osaka University, 1-1 Osaka University Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| |
Collapse
|
25
|
Evidence for the Mycobacterial Mce4 Transporter Being a Multiprotein Complex. J Bacteriol 2021; 203:JB.00685-20. [PMID: 33649150 DOI: 10.1128/jb.00685-20] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/24/2021] [Indexed: 01/01/2023] Open
Abstract
Mycobacteria possess Mce transporters that import lipids and are thought to function analogously to ATP-binding cassette (ABC) transporters. However, whereas ABC transporters import substrates using a single solute-binding protein (SBP) to deliver a substrate to permease proteins in the membrane, mycobacterial Mce transporters have a potential for six SBPs (MceA to MceF) working with a pair of permeases (YrbEA and YrbEB), a cytoplasmic ATPase (MceG), and multiple Mce-associated membrane (Mam) and orphaned Mam (Omam) proteins to transport lipids. In this study, we used the model mycobacterium Mycobacterium smegmatis to study the requirement for individual Mce, Mam, and Omam proteins in Mce4 transport of cholesterol. All of the Mce4 and Mam4 proteins we investigated were required for cholesterol uptake. However, not all Omam proteins, which are encoded by genes outside mce loci, proved to contribute to cholesterol import. OmamA and OmamB were required for cholesterol import, while OmamC, OmamD, OmamE, and OmamF were not. In the absence of any single Mce4, Mam4, or Omam protein that we tested, the abundance of Mce4A and Mce4E declined. This relationship between the levels of Mce4A and Mce4E and these additional proteins suggests a network of interactions that assemble and/or stabilize a multiprotein Mce4 transporter complex. Further support for Mce transporters being multiprotein complexes was obtained by immunoprecipitation-mass spectrometry, in which we identified every single Mce, YrbE, MceG, Mam, and Omam protein with a role in cholesterol transport as associating with Mce4A. This study represents the first time any of these Mce4 transporter proteins has been shown to associate.IMPORTANCE How lipids travel between membranes of diderm bacteria is a challenging mechanistic question because lipids, which are hydrophobic molecules, must traverse a hydrophilic periplasm. This question is even more complex for mycobacteria, which have a unique cell envelope that is highly impermeable to molecules. A growing body of knowledge identifies Mce transporters as lipid importers for mycobacteria. Here, using protein stability experiments and immunoprecipitation-mass spectrometry, we provide evidence for mycobacterial Mce transporters existing as multiprotein complexes.
Collapse
|
26
|
Zlatkov N, Nadeem A, Uhlin BE, Wai SN. Eco-evolutionary feedbacks mediated by bacterial membrane vesicles. FEMS Microbiol Rev 2021; 45:fuaa047. [PMID: 32926132 PMCID: PMC7968517 DOI: 10.1093/femsre/fuaa047] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 09/11/2020] [Indexed: 12/27/2022] Open
Abstract
Bacterial membrane vesicles (BMVs) are spherical extracellular organelles whose cargo is enclosed by a biological membrane. The cargo can be delivered to distant parts of a given habitat in a protected and concentrated manner. This review presents current knowledge about BMVs in the context of bacterial eco-evolutionary dynamics among different environments and hosts. BMVs may play an important role in establishing and stabilizing bacterial communities in such environments; for example, bacterial populations may benefit from BMVs to delay the negative effect of certain evolutionary trade-offs that can result in deleterious phenotypes. BMVs can also perform ecosystem engineering by serving as detergents, mediators in biochemical cycles, components of different biofilms, substrates for cross-feeding, defense systems against different dangers and enzyme-delivery mechanisms that can change substrate availability. BMVs further contribute to bacteria as mediators in different interactions, with either other bacterial species or their hosts. In short, BMVs extend and deliver phenotypic traits that can have ecological and evolutionary value to both their producers and the ecosystem as a whole.
Collapse
Affiliation(s)
- Nikola Zlatkov
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187 Umeå, Sweden
| | - Aftab Nadeem
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187 Umeå, Sweden
| | - Bernt Eric Uhlin
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187 Umeå, Sweden
| | - Sun Nyunt Wai
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, SE-90187 Umeå, Sweden
| |
Collapse
|
27
|
Gupta I, Chakraborty J, Roy S, Farinas ET, Mitra S. Nanocarbon immobilized membranes for generating bacteria and endotoxin free water via membrane distillation. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2020.118133] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
28
|
Bibi M, Murphy S, Benhamou RI, Rosenberg A, Ulman A, Bicanic T, Fridman M, Berman J. Combining Colistin and Fluconazole Synergistically Increases Fungal Membrane Permeability and Antifungal Cidality. ACS Infect Dis 2021; 7:377-389. [PMID: 33471513 PMCID: PMC7887753 DOI: 10.1021/acsinfecdis.0c00721] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Indexed: 12/17/2022]
Abstract
The increasing emergence of drug-resistant fungal pathogens, together with the limited number of available antifungal drugs, presents serious clinical challenges to treating systemic, life-threatening infections. Repurposing existing drugs to augment the antifungal activity of well-tolerated antifungals is a promising antifungal strategy with the potential to be implemented rapidly. Here, we explored the mechanism by which colistin, a positively charged lipopeptide antibiotic, enhances the antifungal activity of fluconazole, the most widely used orally available antifungal. In a range of susceptible and drug-resistant isolates and species, colistin was primarily effective at reducing fluconazole tolerance, a property of subpopulations of cells that grow slowly in the presence of a drug and may promote the emergence of persistent infections and resistance. Clinically relevant concentrations of colistin synergized with fluconazole, reducing fluconazole minimum inhibitory concentration 4-fold. Combining fluconazole and colistin also increased survival in a C. albicans Galleria mellonella infection, especially for a highly fluconazole-tolerant isolate. Mechanistically, colistin increased permeability to fluorescent antifungal azole probes and to intracellular dyes, accompanied by an increase in cell death that was dependent upon pharmacological or genetic inhibition of the ergosterol biosynthesis pathway. The positive charge of colistin is critical to its antifungal, and antibacterial, activity: colistin directly binds to several eukaryotic membrane lipids (i.e., l-α-phosphatidylinositol, l-α-phosphatidyl-l-serine, and l-α-phosphatidylethanolamine) that are enriched in the membranes of ergosterol-depleted cells. These results support the idea that colistin binds to fungal membrane lipids and permeabilizes fungal cells in a manner that depends upon the degree of ergosterol depletion.
Collapse
Affiliation(s)
- Maayan Bibi
- Shmunis
School of Biomedical and Cancer Research, George S. Wise Faculty of
Life Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
| | - Sarah Murphy
- Institute
for Infection and Immunity, St George’s
University, Cranmer Terrace, London SW17 0RE, United Kingdom
| | - Raphael I. Benhamou
- School
of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
| | - Alex Rosenberg
- Shmunis
School of Biomedical and Cancer Research, George S. Wise Faculty of
Life Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
| | - Adi Ulman
- Shmunis
School of Biomedical and Cancer Research, George S. Wise Faculty of
Life Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
| | - Tihana Bicanic
- Institute
for Infection and Immunity, St George’s
University, Cranmer Terrace, London SW17 0RE, United Kingdom
- Clinical
Academic Group in Infection, St George’s
Hospital NHS Trust, London SW17 0QT, United Kingdom
| | - Micha Fridman
- School
of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
| | - Judith Berman
- Shmunis
School of Biomedical and Cancer Research, George S. Wise Faculty of
Life Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
| |
Collapse
|
29
|
Dezanet C, Kempf J, Mingeot-Leclercq MP, Décout JL. Amphiphilic Aminoglycosides as Medicinal Agents. Int J Mol Sci 2020; 21:E7411. [PMID: 33049963 PMCID: PMC7583001 DOI: 10.3390/ijms21197411] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 09/27/2020] [Accepted: 10/02/2020] [Indexed: 12/25/2022] Open
Abstract
The conjugation of hydrophobic group(s) to the polycationic hydrophilic core of the antibiotic drugs aminoglycosides (AGs), targeting ribosomal RNA, has led to the development of amphiphilic aminoglycosides (AAGs). These drugs exhibit numerous biological effects, including good antibacterial effects against susceptible and multidrug-resistant bacteria due to the targeting of bacterial membranes. In the first part of this review, we summarize our work in identifying and developing broad-spectrum antibacterial AAGs that constitute a new class of antibiotic agents acting on bacterial membranes. The target-shift strongly improves antibiotic activity against bacterial strains that are resistant to the parent AG drugs and to antibiotic drugs of other classes, and renders the emergence of resistant Pseudomonas aeruginosa strains highly difficult. Structure-activity and structure-eukaryotic cytotoxicity relationships, specificity and barriers that need to be crossed in their development as antibacterial agents are delineated, with a focus on their targets in membranes, lipopolysaccharides (LPS) and cardiolipin (CL), and the corresponding mode of action against Gram-negative bacteria. At the end of the first part, we summarize the other recent advances in the field of antibacterial AAGs, mainly published since 2016, with an emphasis on the emerging AAGs which are made of an AG core conjugated to an adjuvant or an antibiotic drug of another class (antibiotic hybrids). In the second part, we briefly illustrate other biological and biochemical effects of AAGs, i.e., their antifungal activity, their use as delivery vehicles of nucleic acids, of short peptide (polyamide) nucleic acids (PNAs) and of drugs, as well as their ability to cleave DNA at abasic sites and to inhibit the functioning of connexin hemichannels. Finally, we discuss some aspects of structure-activity relationships in order to explain and improve the target selectivity of AAGs.
Collapse
Affiliation(s)
- Clément Dezanet
- Molecular Pharmacochemistry Department, University Grenoble Alpes, CNRS, 470 Rue de la Chimie, F-38000 Grenoble, France; (C.D.); (J.K.)
| | - Julie Kempf
- Molecular Pharmacochemistry Department, University Grenoble Alpes, CNRS, 470 Rue de la Chimie, F-38000 Grenoble, France; (C.D.); (J.K.)
| | - Marie-Paule Mingeot-Leclercq
- Cellular and Molecular Pharmacology Unit, Louvain Drug Research Institute, Catholic University of Louvain, Avenue E. Mounier 73, UCL B1.73.05, 1200 Brussels, Belgium
| | - Jean-Luc Décout
- Molecular Pharmacochemistry Department, University Grenoble Alpes, CNRS, 470 Rue de la Chimie, F-38000 Grenoble, France; (C.D.); (J.K.)
| |
Collapse
|
30
|
Chang Y, Liu QY, Zhang Q, Rong YM, Lu CZ, Li H. Role of nutritional status and nutritional support in outcome of hepatitis B virus-associated acute-on-chronic liver failure. World J Gastroenterol 2020; 26:4288-4301. [PMID: 32848334 PMCID: PMC7422541 DOI: 10.3748/wjg.v26.i29.4288] [Citation(s) in RCA: 6] [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: 04/11/2020] [Revised: 07/04/2020] [Accepted: 07/14/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Hepatitis B virus-associated acute-on-chronic liver failure (HBV-ACLF) is an important type of liver failure in Asia. There is a direct relationship between HBV-ACLF and gastrointestinal barrier function. However, the nutritional status of HBV-ACLF patients has been poorly studied.
AIM To investigate the nutritional risk and nutritional status of HBV-ACLF patients and evaluated the impact of nutritional support on the gastrointestinal barrier and 28-d mortality.
METHODS Nutritional risk screening assessment and gastrointestinal barrier biomarkers of patients with HBV-ACLF (n = 234) and patients in the compensatory period of liver cirrhosis (the control group) (n = 234) were compared during the period between 2016 and 2018. Changes were analyzed after nutritional support in HBV-ACLF patients. Valuable biomarkers have been explored to predict 28-d death. The 28-d survival between HBV-ACLF patients with nutritional support (n = 234) or no nutritional support (2014-2016) (n = 207) was compared.
RESULTS The nutritional risk of the HBV-ACLF patients was significantly higher than that of the control group. The nutritional intake of the patients with HBV-ACLF was lower than that of the control group. The decrease in skeletal muscle and fat content and the deficiency of fat intake were more obvious (P < 0.001). The coccus-bacillus ratio, secretory immunoglobulin A, and serum D-lactate were significantly increased in HBV-ACLF patients. The survival group had a lower nutritional risk, lower D-lactate, and cytokine levels (endotoxin, tumor necrosis factor alpha, interleukin-10, and interleukin-1). Interleukin-10 may be a potential predictor of death in HBV-ACLF patients. The 28-d survival of the nutritional support group was better than that of the non-nutritional support group (P = 0.016).
CONCLUSION Patients with HBV-ACLF have insufficient nutritional intake and high nutritional risk, and their intestinal barrier function is impaired. Individualized and dynamic nutritional support is associated with a better prognosis of 28-d mortality in HBV-ACLF patients.
Collapse
Affiliation(s)
- Yue Chang
- Division of Gastroenterology and Hepatology, Tianjin Xiqing Hospital, Tianjin 300380, China
- Tianjin Key Laboratory of Hepatopancreatic Fibrosis and Molecular Diagnosis and Treatment, Tianjin 300162, China
- Department of Hepatopancreatobiliary and Splenic Medicine, Characteristic Medical Center of People's Armed Police Force, Tianjin 300162, China
| | - Qin-Yu Liu
- Tianjin Key Laboratory of Hepatopancreatic Fibrosis and Molecular Diagnosis and Treatment, Tianjin 300162, China
- Department of Hepatopancreatobiliary and Splenic Medicine, Characteristic Medical Center of People's Armed Police Force, Tianjin 300162, China
| | - Qing Zhang
- Division of Gastroenterology and Hepatology, Tianjin Xiqing Hospital, Tianjin 300380, China
- Tianjin Key Laboratory of Hepatopancreatic Fibrosis and Molecular Diagnosis and Treatment, Tianjin 300162, China
| | - Ya-Mei Rong
- Tianjin Key Laboratory of Hepatopancreatic Fibrosis and Molecular Diagnosis and Treatment, Tianjin 300162, China
- Department of Hepatopancreatobiliary and Splenic Medicine, Characteristic Medical Center of People's Armed Police Force, Tianjin 300162, China
| | - Cheng-Zhen Lu
- Department of Infectious Diseases, Tianjin Second People's Hospital, Tianjin 300192, China
| | - Hai Li
- Division of Gastroenterology and Hepatology, Tianjin Xiqing Hospital, Tianjin 300380, China
- Tianjin Key Laboratory of Hepatopancreatic Fibrosis and Molecular Diagnosis and Treatment, Tianjin 300162, China
- Department of Hepatopancreatobiliary and Splenic Medicine, Characteristic Medical Center of People's Armed Police Force, Tianjin 300162, China
| |
Collapse
|
31
|
Cania B, Vestergaard G, Kublik S, Köhne JM, Fischer T, Albert A, Winkler B, Schloter M, Schulz S. Biological Soil Crusts from Different Soil Substrates Harbor Distinct Bacterial Groups with the Potential to Produce Exopolysaccharides and Lipopolysaccharides. MICROBIAL ECOLOGY 2020; 79:326-341. [PMID: 31372685 DOI: 10.1007/s00248-019-01415-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 07/16/2019] [Indexed: 06/10/2023]
Abstract
Biological soil crusts (biocrusts) play an important role in improving soil stability and resistance to erosion by promoting aggregation of soil particles. During initial development, biocrusts are dominated by bacteria. Some bacterial members of the biocrusts can contribute to the formation of soil aggregates by producing exopolysaccharides and lipopolysaccharides that act as "glue" for soil particles. However, little is known about the dynamics of "soil glue" producers during the initial development of biocrusts. We hypothesized that different types of initial biocrusts harbor distinct producers of adhesive polysaccharides. To investigate this, we performed a microcosm experiment, cultivating biocrusts on two soil substrates. High-throughput shotgun sequencing was used to obtain metagenomic information on microbiomes of bulk soils from the beginning of the experiment, and biocrusts sampled after 4 and 10 months of incubation. We discovered that the relative abundance of genes involved in the biosynthesis of exopolysaccharides and lipopolysaccharides increased in biocrusts compared with bulk soils. At the same time, communities of potential "soil glue" producers that were highly similar in bulk soils underwent differentiation once biocrusts started to develop. In the bulk soils, the investigated genes were harbored mainly by Betaproteobacteria, whereas in the biocrusts, the major potential producers of adhesive polysaccharides were, aside from Alphaproteobacteria, either Cyanobacteria or Chloroflexi and Acidobacteria. Overall, our results indicate that the potential to form exopolysaccharides and lipopolysaccharides is an important bacterial trait for initial biocrusts and is maintained despite the shifts in bacterial community composition during biocrust development.
Collapse
Affiliation(s)
- Barbara Cania
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Gisle Vestergaard
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
- Section for Bioinformatics, Department of Health Technology, Technical University of Denmark, 2800, Lyngby, Denmark
| | - Susanne Kublik
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - John Maximilian Köhne
- Department of Soil System Science, Helmholtz Centre for Environmental Research (UFZ), Theodor-Lieser-Straße 4, 06120, Halle, Germany
| | - Thomas Fischer
- Central Analytical Laboratory, Brandenburg Technical University, Konrad-Wachsmann-Allee 6, 03046, Cottbus, Germany
| | - Andreas Albert
- Research Unit Environmental Simulation, Helmholtz Zentrum München Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Barbro Winkler
- Research Unit Environmental Simulation, Helmholtz Zentrum München Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Michael Schloter
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
- Chair for Soil Science, Technical University of Munich, Emil-Ramann-Straße 2, 85354, Freising, Germany
| | - Stefanie Schulz
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany.
| |
Collapse
|
32
|
Shou J, Kong X, Wang X, Tang Y, Wang C, Wang M, Zhang L, Liu Y, Fei C, Xue F, Li J, Zhang K. Tizoxanide Inhibits Inflammation in LPS-Activated RAW264.7 Macrophages via the Suppression of NF-κB and MAPK Activation. Inflammation 2020; 42:1336-1349. [PMID: 30937840 DOI: 10.1007/s10753-019-00994-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Tizoxanide is the main active metabolite of nitazoxanide. Nitazoxanide and tizoxanide have a broad-spectrum anti-infective effect, including parasites, bacteria, and virus. In the present study, we investigated the anti-inflammatory effect of tizoxanide on lipopolysaccharide (LPS)-stimulated RAW264.7 cells and revealed underlying molecular mechanisms. The results showed that tizoxanide significantly suppressed production of NO as well as pro-inflammatory cytokines, such as IL-1β, IL-6, and TNF-α in dose-dependent manner. Meanwhile, the levels of gene expression of these cytokines were inhibited significantly by tizoxanide that was discovered using RT-PCR. The increased protein levels of inducible nitric oxide synthase, heme oxygenase-1, and cyclooxygenase-2 by LPS in the cells were also reduced by tizoxanide. Moreover, we found that tizoxanide inhibited the phosphorylation of IKK-α and degradation of IκB by LPS in macrophage cells. The increased protein levels of p65 induced by LPS in the cytoplasm and nucleus were both decreased by tizoxanide, and the nuclear translocation of p65 was also restrained in cell imaging. In addition, tizoxanide considerably also inhibited LPS-activated JNK, p38, and ERK phosphorylation in RAW264.7 cells. Taken together, our results suggested that tizoxanide exerts anti-inflammatory effects, by inhibiting the production of pro-inflammatory cytokines and suppressing of the activation of the NF-κB and the MAPK signaling pathways in LPS-treated macrophage cells.
Collapse
Affiliation(s)
- Jiaoqin Shou
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 518 Ziyue RD, Minhang District, Shanghai, 200241, China.,College of Chemistry, Xiangtan University, Yuhu District, Xiangtan, 411105, Hunan, China
| | - Xiangzhen Kong
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 518 Ziyue RD, Minhang District, Shanghai, 200241, China
| | - Xiaoyang Wang
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 518 Ziyue RD, Minhang District, Shanghai, 200241, China
| | - Ying Tang
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 518 Ziyue RD, Minhang District, Shanghai, 200241, China
| | - Chunmei Wang
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 518 Ziyue RD, Minhang District, Shanghai, 200241, China
| | - Mi Wang
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 518 Ziyue RD, Minhang District, Shanghai, 200241, China
| | - Lifang Zhang
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 518 Ziyue RD, Minhang District, Shanghai, 200241, China
| | - Yingchun Liu
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 518 Ziyue RD, Minhang District, Shanghai, 200241, China
| | - Chenzhong Fei
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 518 Ziyue RD, Minhang District, Shanghai, 200241, China
| | - Feiqun Xue
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 518 Ziyue RD, Minhang District, Shanghai, 200241, China
| | - Juan Li
- College of Chemistry, Xiangtan University, Yuhu District, Xiangtan, 411105, Hunan, China
| | - Keyu Zhang
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 518 Ziyue RD, Minhang District, Shanghai, 200241, China.
| |
Collapse
|
33
|
Zi SF, Li JH, Liu L, Deng C, Ao X, Chen DD, Wu SZ. Dexmedetomidine-mediated protection against septic liver injury depends on TLR4/MyD88/NF-κB signaling downregulation partly via cholinergic anti-inflammatory mechanisms. Int Immunopharmacol 2019; 76:105898. [PMID: 31520992 DOI: 10.1016/j.intimp.2019.105898] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/06/2019] [Accepted: 09/06/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Uncontrolled inflammatory responses exacerbate the pathogenesis of septic acute liver injury (ALI), posing a lethal threat to the host. Dexmedetomidine (DEX) has been reported to possess protective properties in inflammatory conditions. This study aimed to investigate whether DEX pretreatment exhibits hepatoprotection against ALI induced by lipopolysaccharide (LPS) in rats and determine its possible molecular mechanism. METHODS Septic ALI was induced by intravenous injection of LPS. The rats received DEX intraperitoneally 30 min before LPS administration. α-Bungarotoxin (α-BGT), a specific α7 nicotinic acetylcholine receptor (α7nAChR) antagonist, was administered intraperitoneally 1 h before LPS exposure. The role of the vagus nerve was verified by performing unilateral cervical vagotomy or sham surgery before sepsis. RESULTS The expression of α7nAChR, toll-like receptor 4 (TLR4), high mobility group box 1 (HMGB1), and cleaved caspase-3 increased, peaking 24 h during sepsis. DEX enhanced α7nAChR activation and reduced TLR4 expression upon challenge with LPS. DEX significantly prevented LPS-induced ALI, which was associated with increased survival, the mitigation of pathological changes, the attenuation of inflammatory cytokine expression and apoptosis, and the downregulation of TLR4/MyD88/NF-κB pathway. Moreover, the hepatoprotective effect of DEX was abolished by α-BGT. Further investigation established that vagotomy, compared to sham surgery, triggered more severe pathogenic manifestations and higher proinflammatory cytokine levels. The inhibitory effects of DEX were shown in sham-operated rats but not in vagotomized rats. CONCLUSIONS Our data highlight the pivotal function of α7nAChR and intact vagus nerves in protecting against LPS-induced ALI through inhibiting the TLR4/MyD88/NF-κB signaling pathway upon pretreatment with DEX.
Collapse
Affiliation(s)
- Shuang-Feng Zi
- Department of Critical Care Medicine, Affiliated Haikou Hospital, Xiangya School of Medicine, Central South University, Haikou 570208, China
| | - Jing-Hui Li
- Department of Critical Care Medicine, Affiliated Haikou Hospital, Xiangya School of Medicine, Central South University, Haikou 570208, China.
| | - Lei Liu
- Department of Critical Care Medicine, Affiliated Haikou Hospital, Xiangya School of Medicine, Central South University, Haikou 570208, China
| | - Chao Deng
- Department of Critical Care Medicine, Affiliated Haikou Hospital, Xiangya School of Medicine, Central South University, Haikou 570208, China
| | - Xue Ao
- Department of Critical Care Medicine, Affiliated Haikou Hospital, Xiangya School of Medicine, Central South University, Haikou 570208, China
| | - Dan-Dan Chen
- Department of Critical Care Medicine, Affiliated Haikou Hospital, Xiangya School of Medicine, Central South University, Haikou 570208, China
| | - Sheng-Zan Wu
- Department of Critical Care Medicine, Affiliated Haikou Hospital, Xiangya School of Medicine, Central South University, Haikou 570208, China
| |
Collapse
|
34
|
Mir DA, Balamurugan K. In vitro and in vivo efficacy of Caenorhabditis elegans recombinant antimicrobial protein against Gram-negative bacteria. BIOFOULING 2019; 35:900-921. [PMID: 31617758 DOI: 10.1080/08927014.2019.1675048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 09/26/2019] [Accepted: 09/27/2019] [Indexed: 06/10/2023]
Abstract
Antimicrobial peptides (AMPs) are short, positively charged host defense peptides, found in various life forms from microorganisms to humans. AMPs are gaining more attention as substitutes for antibiotics in order to combat the risk posed by multi-drug- resistant pathogens. The nematode Caenorhabditis elegans relies solely on its innate immune defense to cope with its challenging life-style. Bacterial infection in C. elegans leads to induction of antimicrobial proteins, defensins, nemapores, cecropins, and neuropeptide-like proteins, which act to limit bacterial proliferation. This study reports how the C. elegans recombinant antibacterial factor (ABF-1) rapidly inhibited bacterial growth (Salmonella Typhi, Klebsiella pneumonia, Shigella sonnei and Vibrio alginolyticus). The ABF-1 exposure on S. Typhi, showed differential regulation in cell-cycle, DNA repair mechanism, membrane stability, and stress related proteins. The exogenous supply of ABF-1 protein has extended C. elegans survival by reducing the bacterial colony forming units on the nematode intestine. Together, these findings indicate the valuable and potential therapeutic applications of ABF-1 protein as antimicrobial agents against intracellular pathogens.
Collapse
|
35
|
The Lpt ABC transporter for lipopolysaccharide export to the cell surface. Res Microbiol 2019; 170:366-373. [PMID: 31376484 DOI: 10.1016/j.resmic.2019.07.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/11/2019] [Accepted: 07/13/2019] [Indexed: 10/26/2022]
Abstract
The surface of the outer membrane of Gram-negative bacteria is covered by a tightly packed layer of lipopolysaccharide molecules which provide a barrier against many toxic compounds and antibiotics. Lipopolysaccharide, synthesized in the cytoplasm, is assembled in the periplasmic leaflet of the inner membrane where the intermembrane Lpt system mediates its transport to the cell surface. The first step of lipopolysaccharide transport is its extraction from the outer leaflet of inner membrane powered by the atypical LptB2FGC ABC transporter. Here we review latest advances leading to understanding at molecular level how lipopolysaccharide is transported irreversibly to the outer membrane.
Collapse
|
36
|
Huang L, Wang M, Mo T, Liu M, Biville F, Zhu D, Jia R, Chen S, Zhao X, Yang Q, Wu Y, Zhang S, Huang J, Tian B, Liu Y, Zhang L, Yu Y, Pan L, Rehman MU, Chen X, Cheng A. Role of LptD in Resistance to Glutaraldehyde and Pathogenicity in Riemerella anatipestifer. Front Microbiol 2019; 10:1443. [PMID: 31281307 PMCID: PMC6598057 DOI: 10.3389/fmicb.2019.01443] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Accepted: 06/07/2019] [Indexed: 11/25/2022] Open
Abstract
Riemerella anatipestifer is a gram-negative bacterium that causes disease in ducks and other birds. Despite being an important pathogen in poultry, the pathogenesis and drug resistance mechanisms of this bacterium are poorly understood. An analysis of our unpublished RNA-Seq data showed that lptD, a gene encoding one of the lipopolysaccharide transport components, is transcribed at higher levels in strain CH-1 than in strain ATCC11845. In addition, strain CH-1 has been shown to display broader drug resistance than strain ATCC11845. Since LptD is involved in LPS biogenesis and drug resistance, we wondered if lptD is associated with increased R. anatipestifer resistance to glutaraldehyde, a disinfectant used in the production industry. In this study, the minimal inhibitory concentration (MIC) of glutaraldehyde for strain CH-1 was determined to be 0.125% (vol/vol), whereas an MIC of 0.05% (vol/vol) was observed for strain ATCC11845. Furthermore, the level of lptD transcription in strain CH-1 was consistently 2-fold higher than that observed in strain ATCC11845. Moreover, lptD transcription was upregulated in both strains at a subinhibitory concentration of glutaraldehyde. The role of lptD in R. anatipestifer was further assessed by constructing an ATCC11845 mutant strain with low lptD expression, R. anatipestifer ATCC11845 lptD−. The growth of R. anatipestifer ATCC11845 lptD− was severely impaired, and this strain was more susceptible than the wild-type strain to glutaraldehyde. Moreover, compared to the wild-type strain, R. anatipestifer ATCC11845 lptD− exhibited decreased biofilm formation and was more sensitive to duck serum. Finally, low lptD expression led to decreased colonization in ducklings. These results suggest that LptD is involved in R. anatipestifer glutaraldehyde resistance and pathogenicity.
Collapse
Affiliation(s)
- Li Huang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Ting Mo
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | | | - Dekang Zhu
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Xinxin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Juan Huang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Bin Tian
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Yunya Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Ling Zhang
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Yanling Yu
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Leichang Pan
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Mujeeb Ur Rehman
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Xiaoyue Chen
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, China
| |
Collapse
|
37
|
SAA1 increases NOX4/ROS production to promote LPS-induced inflammation in vascular smooth muscle cells through activating p38MAPK/NF-κB pathway. BMC Mol Cell Biol 2019; 20:15. [PMID: 31216990 PMCID: PMC6582534 DOI: 10.1186/s12860-019-0197-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 05/17/2019] [Indexed: 01/01/2023] Open
Abstract
Background To investigate the effects of serum amyloid A1 (SAA1) on lipopolysaccharide (LPS) -induced inflammation in vascular smooth muscle cells (VSMCs). SAA1 expression was detected in LPS induced VSMCs at different concentrations for different time by using Western blotting. After pre-incubation with recombinant SAA1 protein, VSMCs were treated with 1 μg/ml LPS for 24 h. The VSMCs were then divided into Control, SAA1 siRNA, Nox4 siRNA, LPS, LPS + SAA1 siRNA, LPS + Nox4 siRNA and LPS + SAA1 siRNA + Nox4 groups. MTT was performed to observe the toxicity of VSMCs. Lucigenin-enhanced chemiluminescence method was used to detect superoxide anion (O2−) production and NADPH oxidase activity. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine expressions of inflammatory factors. Western blotting was used to determine expressions of NOX-4 and p38MAPK/NF-κB pathway related proteins. Results LPS promoted SAA1 protein expression in a concentration−/time-dependent manner. Recombinant SAA1 protein could increase NOX4/ROS production and promote the release of inflammatory factors (IL-1β, IL-6, IL-8, IL-17, TNF-α and MCP-1) in LPS (1 μg/ml) - induced VSMCs. Besides, both SAA1 siRNA and NOX-4 siRNA could not only enhance the O2− production and NADPH oxidase activity, but also up-regulate the protein expression of NOX4, the release of inflammatory factors, and the levels of p-p38 and p-NF-κB p65 in LPS-induced VSMCs. However, no significant differences in each index were observed between LPS group and LPS + SAA1 siRNA + Nox4 group. Conclusion SAA1-mediated NOX4/ROS pathway could activate p38MAPK/NF-κB pathway, thereby contributing to the release of inflammatory factors in LPS-induced VSMCs.
Collapse
|
38
|
Kesireddy A, Pothula KR, Lee J, Patel DS, Pathania M, van den Berg B, Im W, Kleinekathöfer U. Modeling of Specific Lipopolysaccharide Binding Sites on a Gram-Negative Porin. J Phys Chem B 2019; 123:5700-5708. [DOI: 10.1021/acs.jpcb.9b03669] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Anusha Kesireddy
- Department of Physics and Earth Sciences, Jacobs University Bremen, 28759 Bremen, Germany
| | - Karunakar R. Pothula
- Department of Physics and Earth Sciences, Jacobs University Bremen, 28759 Bremen, Germany
| | - Jumin Lee
- Departments of Biological Sciences and Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Dhilon S. Patel
- Departments of Biological Sciences and Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Monisha Pathania
- Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Bert van den Berg
- Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Wonpil Im
- Departments of Biological Sciences and Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Ulrich Kleinekathöfer
- Department of Physics and Earth Sciences, Jacobs University Bremen, 28759 Bremen, Germany
| |
Collapse
|
39
|
Lo Sciuto A, Martorana AM, Fernández-Piñar R, Mancone C, Polissi A, Imperi F. Pseudomonas aeruginosa LptE is crucial for LptD assembly, cell envelope integrity, antibiotic resistance and virulence. Virulence 2019; 9:1718-1733. [PMID: 30354941 PMCID: PMC7204523 DOI: 10.1080/21505594.2018.1537730] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Lipopolysaccharide (LPS) is an essential structural component of the outer membrane (OM) of most Gram-negative bacteria. In the model organism Escherichia coli, LPS transport to the OM requires seven essential proteins (LptABCDEFG) that form a continuous bridge across the cell envelope. In Pseudomonas aeruginosa the recently-demonstrated essentiality of LptD and LptH, the P. aeruginosa LptA homologue, confirmed the crucial role of the Lpt system and, thus, of LPS in OM biogenesis in this species. Surprisingly, independent high-throughput transposon mutagenesis studies identified viable P. aeruginosa insertion mutants in the lptE gene, suggesting that it might be dispensable for bacterial growth. To test this hypothesis, we generated an lptE conditional mutant in P. aeruginosa PAO1. LptE depletion only slightly impairs P. aeruginosa growth in vitro. Conversely, LptE is important for cell envelope stability, antibiotic resistance and virulence in an insect model. Interestingly, the maturation and OM localization of LPS is only marginally affected in LptE-depleted cells, while the levels of the OM component LptD are strongly reduced. This suggests that P. aeruginosa LptE might not be directly involved in LPS transport, although it is clearly essential for the maturation and/or stability of LptD. While poor functionality of LptD caused by LptE depletion is somehow tolerated by P. aeruginosa, this has a high cost in terms of cell integrity, drug resistance and virulence, highlighting LptE function(s) as an interesting target to weaken P. aeruginosa defenses and reduce its infectivity.
Collapse
Affiliation(s)
- Alessandra Lo Sciuto
- a Department of Biology and Biotechnology Charles Darwin , Sapienza University of Rome, Laboratory affiliated to Istituto Pasteur Italia - Fondazione Cenci Bolognetti , Rome , Italy
| | - Alessandra M Martorana
- b Department of Pharmacological and Biomolecular Sciences , University of Milan , Milan , Italy
| | - Regina Fernández-Piñar
- a Department of Biology and Biotechnology Charles Darwin , Sapienza University of Rome, Laboratory affiliated to Istituto Pasteur Italia - Fondazione Cenci Bolognetti , Rome , Italy
| | - Carmine Mancone
- c Department of Cellular Biotechnologies and Haematology , Sapienza University of Rome , Rome , Italy
| | - Alessandra Polissi
- b Department of Pharmacological and Biomolecular Sciences , University of Milan , Milan , Italy
| | - Francesco Imperi
- a Department of Biology and Biotechnology Charles Darwin , Sapienza University of Rome, Laboratory affiliated to Istituto Pasteur Italia - Fondazione Cenci Bolognetti , Rome , Italy
| |
Collapse
|
40
|
Pankov G, Dawson A, Hunter WN. The structure of lipopolysaccharide transport protein B (LptB) from Burkholderia pseudomallei. Acta Crystallogr F Struct Biol Commun 2019; 75:227-232. [PMID: 30950822 PMCID: PMC6450526 DOI: 10.1107/s2053230x19001778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 01/30/2019] [Indexed: 11/10/2022] Open
Abstract
The thick outer membrane (OM) of Gram-negative bacteria performs an important protective role against hostile environments, supports cell integrity, and contributes to surface adhesion and in some cases also to virulence. A major component of the OM is lipopolysaccharide (LPS), a complex glycolipid attached to a core containing fatty-acyl chains. The assembly and transport of lipid A, the membrane anchor for LPS, to the OM begins when a heteromeric LptB2FG protein complex extracts lipid A from the outer leaflet of the inner membrane. This process requires energy, and upon hydrolysis of ATP one component of the heteromeric assembly, LptB, triggers a conformational change in LptFG in support of lipid A transport. A structure of LptB from the intracellular pathogen Burkholderia pseudomallei is reported here. LptB forms a dimer that displays a relatively fixed structure irrespective of whether it is in complex with LptFG or in isolation. Highly conserved sequence and structural features are discussed that allow LptB to fuel the transport of lipid A.
Collapse
Affiliation(s)
- Genady Pankov
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland
| | - Alice Dawson
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland
| | - William N. Hunter
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland
| |
Collapse
|
41
|
Identification of a lytic Pseudomonas aeruginosa phage depolymerase and its anti-biofilm effect and bactericidal contribution to serum. Virus Genes 2019; 55:394-405. [PMID: 30937696 DOI: 10.1007/s11262-019-01660-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 03/26/2019] [Indexed: 10/27/2022]
Abstract
Pseudomonas aeruginosa (P. aeruginosa) infection has imposed a great threat to patients with cystic fibrosis. With the emergence of multidrug-resistant P. aeruginosa, developing an alternative anti-microbial strategy is indispensable and more urgent than ever. In this study, a lytic P. aeruginosa phage was isolated from the sewage of a hospital, and one protein was predicted as the depolymerase-like protein by genomic sequence analysis, it includes two catalytic regions, the Pectate lyase_3 super family and Glycosyl hydrolase_28 super family. Further analysis demonstrated that recombinant depolymerase-like protein degraded P. aeruginosa exopolysaccharide and enhanced bactericidal activity mediated by serum in vitro. Additionally, this protein disrupted host bacterial biofilms. All of these results showed that the phage-derived depolymerase-like protein has the potential to be developed into an anti-microbial agent that targets P. aeruginosa.
Collapse
|
42
|
Abstract
The cell envelope is the first line of defense between a bacterium and the world-at-large. Often, the initial steps that determine the outcome of chemical warfare, bacteriophage infections, and battles with other bacteria or the immune system greatly depend on the structure and composition of the bacterial cell surface. One of the most studied bacterial surface molecules is the glycolipid known as lipopolysaccharide (LPS), which is produced by most Gram-negative bacteria. Much of the initial attention LPS received in the early 1900s was owed to its ability to stimulate the immune system, for which the glycolipid was commonly known as endotoxin. It was later discovered that LPS also creates a permeability barrier at the cell surface and is a main contributor to the innate resistance that Gram-negative bacteria display against many antimicrobials. Not surprisingly, these important properties of LPS have driven a vast and still prolific body of literature for more than a hundred years. LPS research has also led to pioneering studies in bacterial envelope biogenesis and physiology, mostly using Escherichia coli and Salmonella as model systems. In this review, we will focus on the fundamental knowledge we have gained from studies of the complex structure of the LPS molecule and the biochemical pathways for its synthesis, as well as the transport of LPS across the bacterial envelope and its assembly at the cell surface.
Collapse
|
43
|
Nishino K, Tsuchikado R, Nishida H. Sugar enhances outer membrane fusion in Deinococcus grandis spheroplasts to generate calcium ion-dependent extra-huge cells. FEMS Microbiol Lett 2019; 366:5479244. [PMID: 31089699 DOI: 10.1093/femsle/fnz087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 04/24/2019] [Indexed: 01/24/2023] Open
Abstract
In our previous study, we showed that cell fusion occurred in spheroplasts of Deinococcus grandis at 200 mM calcium chloride in the incubation medium. Extra-huge cells (> 0.1 mm in diameter) were observed at this concentration with a low frequency of appearance. In this study, we showed that cell fusion occurred consecutively in D. grandis spheroplasts following an incubation for spheroplast enlargement using medium containing 16.2 mM calcium chloride and 333 mM sucrose. As a result, more extra-huge cells were generated, where cells had maximum diameter of > 1 mm. They can be observed with naked eyes in the incubation medium. The giant cells contained multiple cytoplasms covered by the plasma membrane, indicating that the cell fusion occurred only among the outer membranes. Thus, only the outer membrane and the periplasmic space are shared but not the cytoplasm, indicating that genome of each cell remains in its cytoplasm. Our findings indicate that sugar enhances outer membrane fusion in D. grandis spheroplasts to generate calcium ion-dependent extra-huge cells.
Collapse
Affiliation(s)
- Koki Nishino
- Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Rintaro Tsuchikado
- Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Hiromi Nishida
- Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| |
Collapse
|
44
|
Cania B, Vestergaard G, Krauss M, Fliessbach A, Schloter M, Schulz S. A long-term field experiment demonstrates the influence of tillage on the bacterial potential to produce soil structure-stabilizing agents such as exopolysaccharides and lipopolysaccharides. ENVIRONMENTAL MICROBIOME 2019; 14:1. [PMID: 33902712 PMCID: PMC7989815 DOI: 10.1186/s40793-019-0341-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 03/07/2019] [Indexed: 05/16/2023]
Abstract
BACKGROUND Stable soil aggregates are essential for optimal crop growth and preventing soil erosion. However, tillage is often used in agriculture to loosen the soil, which disrupts the integrity of these aggregates. Soil aggregation can be enhanced by bacteria through their ability to produce exopolysaccharides and lipopolysaccharides. These compounds stabilize soil aggregates by "gluing" soil particles together. However, it has yet to be shown how tillage influences the bacterial potential to produce aggregate-stabilizing agents. Therefore, we sampled conventional and reduced tillage treatments at 0-10 cm, 10-20 cm and 20-50 cm from a long-term field trial in Frick, Switzerland. We compared the stable aggregate fraction of the soil and the bacterial potential to produce exopolysaccharides (EPS) and lipopolysaccharides (LPS) under different tillage regimes by employing a shotgun metagenomic approach. We established a method which combines hidden Markov model searches with blasts against sequences derived from the Kyoto Encyclopedia of Genes and Genomes database to analyze genes specific for the biosynthesis of these compounds. RESULTS Our data revealed that the stable aggregate fraction as well as the bacterial potential to produce EPS and LPS were comparable under both tillage regimes. The highest potential to produce these compounds was found in the upper soil layer, which was disturbed by tillage, but had higher content of organic carbon compared to the layer below the tillage horizon. Additionally, key players of EPS and LPS production differed at different sampling depths. Some families with high potential to produce EPS and LPS, such as Chitinophagaceae and Bradyrhizobiaceae, were more abundant in the upper soil layers, while others, e.g. Nitrospiraceae and Planctomycetaceae, preferred the lowest sampled soil depth. Each family had the potential to form a limited number of different aggregate-stabilizing agents. CONCLUSIONS Our results indicate that conventional tillage and reduced tillage equally promote the bacterial potential to produce EPS and LPS in the tillage horizon. However, as major bacterial groups triggering EPS and LPS formation were not the same, it is likely that gene expression pattern differ in the different treatments due to various pathways of gene induction and transcription in different bacterial species.
Collapse
Affiliation(s)
- Barbara Cania
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Gisle Vestergaard
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
- Section for Bioinformatics, Department of Health Technology, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Maike Krauss
- Department of Soil Sciences, Research Institute of Organic Agriculture (FiBL), Ackerstrasse 113, 5070 Frick, Switzerland
| | - Andreas Fliessbach
- Department of Soil Sciences, Research Institute of Organic Agriculture (FiBL), Ackerstrasse 113, 5070 Frick, Switzerland
| | - Michael Schloter
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
- Soil Science, Technical University of Munich, Emil-Ramann-Straße 2, 85354 Freising, Germany
| | - Stefanie Schulz
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| |
Collapse
|
45
|
Bolla JR, Agasid MT, Mehmood S, Robinson CV. Membrane Protein-Lipid Interactions Probed Using Mass Spectrometry. Annu Rev Biochem 2019; 88:85-111. [PMID: 30901263 DOI: 10.1146/annurev-biochem-013118-111508] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Membrane proteins that exist in lipid bilayers are not isolated molecular entities. The lipid molecules that surround them play crucial roles in maintaining their full structural and functional integrity. Research directed at investigating these critical lipid-protein interactions is developing rapidly. Advancements in both instrumentation and software, as well as in key biophysical and biochemical techniques, are accelerating the field. In this review, we provide a brief outline of structural techniques used to probe protein-lipid interactions and focus on the molecular aspects of these interactions obtained from native mass spectrometry (native MS). We highlight examples in which lipids have been shown to modulate membrane protein structure and show how native MS has emerged as a complementary technique to X-ray crystallography and cryo-electron microscopy. We conclude with a short perspective on future developments that aim to better understand protein-lipid interactions in the native environment.
Collapse
Affiliation(s)
- Jani Reddy Bolla
- Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom;
| | - Mark T Agasid
- Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom;
| | - Shahid Mehmood
- Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom;
| | - Carol V Robinson
- Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom;
| |
Collapse
|
46
|
Owens TW, Taylor RJ, Pahil KS, Bertani BR, Ruiz N, Kruse AC, Kahne D. Structural basis of unidirectional export of lipopolysaccharide to the cell surface. Nature 2019; 567:550-553. [PMID: 30894747 PMCID: PMC6629255 DOI: 10.1038/s41586-019-1039-0] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 02/26/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Tristan W Owens
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Rebecca J Taylor
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Karanbir S Pahil
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Blake R Bertani
- Department of Microbiology, The Ohio State University, Columbus, OH, USA
| | - Natividad Ruiz
- Department of Microbiology, The Ohio State University, Columbus, OH, USA.
| | - Andrew C Kruse
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
| | - Daniel Kahne
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA. .,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
47
|
Sha J, Zhang H, Zhao Y, Feng X, Hu X, Wang C, Song M, Fan H. Dexmedetomidine attenuates lipopolysaccharide-induced liver oxidative stress and cell apoptosis in rats by increasing GSK-3β/MKP-1/Nrf2 pathway activity via the α2 adrenergic receptor. Toxicol Appl Pharmacol 2019; 364:144-152. [DOI: 10.1016/j.taap.2018.12.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/19/2018] [Accepted: 12/24/2018] [Indexed: 12/28/2022]
|
48
|
Chen Q, Cheng P, Ma C, Xi X, Wang L, Zhou M, Bian H, Chen T. Evaluating the Bioactivity of a Novel Broad-Spectrum Antimicrobial Peptide Brevinin-1GHa from the Frog Skin Secretion of Hylarana guentheri and Its Analogues. Toxins (Basel) 2018; 10:toxins10100413. [PMID: 30322120 PMCID: PMC6215227 DOI: 10.3390/toxins10100413] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 10/10/2018] [Accepted: 10/11/2018] [Indexed: 12/26/2022] Open
Abstract
Many antimicrobial peptides (AMPs) have been identified from the skin secretion of the frog Hylarana guentheri (H.guentheri), including Temporin, Brevinin-1, and Brevinin-2. In this study, an antimicrobial peptide named Brevinin-1GHa was identified for the first time by using ‘shotgun’ cloning. The primary structure was also confirmed through mass spectral analysis of the skin secretion purified by reversed-phase high-performance liquid chromatography (RP-HPLC). There was a Rana-box (CKISKKC) in the C-terminal of Brevinin-1GHa, which formed an intra-disulfide bridge. To detect the significance of Rana-box and reduce the hemolytic activity, we chemically synthesized Brevinin-1GHb (without Rana-box) and Brevinin-1GHc (Rana-box in central position). Brevinin-1GHa exhibited a strong and broad-spectrum antimicrobial activity against seven microorganisms, while Brevinin-1GHb only inhibited the growth of Staphylococcus aureus (S. aureus), which indicates Rana-box was necessary for the antimicrobial activity of Brevinin-1GHa. The results of Brevinin-1GHc suggested transferring Rana-box to the central position could reduce the hemolytic activity, but the antimicrobial activity also declined. Additionally, Brevinin-1GHa demonstrated the capability of permeating cell membrane and eliminating biofilm of S. aureus, Escherichia coli (E. coli), and Candida albicans (C. albicans). The discovery of this research may provide some novel insights into natural antimicrobial drug design.
Collapse
Affiliation(s)
- Qi Chen
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210000, China.
- Natural Drug Discovery Group, School of Pharmacy, Queen's University, Belfast BT9 7BL, Northern Ireland, UK.
| | - Peng Cheng
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210000, China.
| | - Chengbang Ma
- Natural Drug Discovery Group, School of Pharmacy, Queen's University, Belfast BT9 7BL, Northern Ireland, UK.
| | - Xinping Xi
- Natural Drug Discovery Group, School of Pharmacy, Queen's University, Belfast BT9 7BL, Northern Ireland, UK.
| | - Lei Wang
- Natural Drug Discovery Group, School of Pharmacy, Queen's University, Belfast BT9 7BL, Northern Ireland, UK.
| | - Mei Zhou
- Natural Drug Discovery Group, School of Pharmacy, Queen's University, Belfast BT9 7BL, Northern Ireland, UK.
| | - Huimin Bian
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210000, China.
| | - Tianbao Chen
- Natural Drug Discovery Group, School of Pharmacy, Queen's University, Belfast BT9 7BL, Northern Ireland, UK.
| |
Collapse
|
49
|
Identification and biochemical characterization of WbwB, a novel UDP-Gal: Neu5Ac-R α1,4-galactosyltransferase from the intestinal pathogen Escherichia coli serotype O104. Glycoconj J 2017; 35:65-76. [PMID: 29063990 DOI: 10.1007/s10719-017-9799-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 09/11/2017] [Accepted: 09/13/2017] [Indexed: 02/08/2023]
Abstract
The intestinal pathogen Escherichia coli serotype O104:H4 (ECO104) can cause bloody diarrhea and haemolytic uremic syndrome. The ECO104 O antigen has the unique repeating unit structure [4Galα1-4Neu5,7,9Ac3α2-3Galβ1-3GalNAcβ1-], which includes the mammalian sialyl-T antigen as an internal structure. Previously, we identified WbwC from ECO104 as the β3Gal-transferase that synthesizes the T antigen, and showed that α3-sialyl-transferase WbwA transfers sialic acid to the T antigen. Here we identify the wbwB gene product as a unique α1,4-Gal-transferase WbwB that transfers Gal from UDP-Gal to the terminal sialic acid residue of Neu5Acα2-3Galβ1-3GalNAcα-diphosphate-lipid acceptor. NMR analysis of the WbwB enzyme reaction product indicated that Galα1-4Neu5Acα2-3Galβ1-3GalNAcα-diphosphate-lipid was synthesized. WbwB from ECO104 has a unique acceptor specificity for terminal sialic acid as well as the diphosphate group in the acceptor. The characterization studies showed that WbwB does not require divalent metal ion as a cofactor. Mutagenesis identified Lys243 within an RKR motif and both Glu315 and Glu323 of the fourth EX7E motif as essential for the activity. WbwB is the final glycosyltransferase in the biosynthesis pathway of the ECO104 antigen repeating unit. This work contributes to knowledge of the biosynthesis of bacterial virulence factors.
Collapse
|
50
|
Sperandeo P, Martorana AM, Polissi A. The lipopolysaccharide transport (Lpt) machinery: A nonconventional transporter for lipopolysaccharide assembly at the outer membrane of Gram-negative bacteria. J Biol Chem 2017; 292:17981-17990. [PMID: 28878019 DOI: 10.1074/jbc.r117.802512] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The outer membrane (OM) of Gram-negative is a unique lipid bilayer containing LPS in its outer leaflet. Because of the presence of amphipathic LPS molecules, the OM behaves as an effective permeability barrier that makes Gram-negative bacteria inherently resistant to many antibiotics. This review focuses on LPS biogenesis and discusses recent advances that have contributed to our understanding of how this complex molecule is transported across the cellular envelope and is assembled at the OM outer leaflet. Clearly, this knowledge represents an important platform for the development of novel therapeutic options to manage Gram-negative infections.
Collapse
Affiliation(s)
- Paola Sperandeo
- From the Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133 Milan and
| | - Alessandra M Martorana
- the Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, 20126 Milan, Italy
| | - Alessandra Polissi
- From the Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133 Milan and
| |
Collapse
|