keyword
MENU ▼
Read by QxMD icon Read
search

Outer membrane vesicles

keyword
https://www.readbyqxmd.com/read/28327712/structural-transformation-of-vesicles-formed-by-a-polystyrene-b-poly-acrylic-acid-polystyrene-b-poly-4-vinyl-pyridine-mixture-from-symmetric-to-asymmetric-membranes
#1
Zhen Geng, Yuanyuan Han, Wei Jiang
Asymmetric vesicles with different inner and outer corona compositions are applicable in microreactors, drug delivery, and biomimics because of their unique functions in membrane permeability and protein localization. In this study, we develop a novel approach to construct asymmetric vesicles and demonstrate the first structural transformation of polymeric vesicles from symmetric to asymmetric membranes. Experimental results and Monte Carlo simulation results clearly reveal that increased intercorona repulsion and enhanced hydrophobic chain mobility are essential to realize this transformation...
March 22, 2017: Soft Matter
https://www.readbyqxmd.com/read/28320881/lpto-pg0027-is-required-for-lipid-a-1-phosphatase-activity-in-porphyromonas-gingivalis-w50
#2
Minnie Rangarajan, Joseph Aduse-Opoku, Ahmed Hashim, Graham McPhail, Zofia Luklinska, M Florencia Haurat, Mario F Feldman, Michael A Curtis
Porphyromonas gingivalis produces outer-membrane vesicles (OMVs) rich in virulence factors including cysteine-proteases and A-LPS, one of the two lipopolysaccharides (LPS) produced by this organism. Previous studies had suggested that A-LPS together with PG0027, an outer-membrane (OM) protein, may be involved in OMV-formation. Their roles in this process were examined using parent W50 and mutant ΔPG0027 strains. Inactivation of PG0027 caused a reduction in yield of OMVs. Lipid A from cells and OMVs of P. gingivalis W50 and ΔPG0027 strains were analysed by matrix-assisted laser-desorption-ionisation-time of flight mass spectrometry (MALDI-TOF- MS)...
March 20, 2017: Journal of Bacteriology
https://www.readbyqxmd.com/read/28287548/legionella-pneumophila-outer-membrane-vesicles-isolation-and-analysis-of-their-pro-inflammatory-potential-on-macrophages
#3
Anna Lena Jung, Kerstin Hoffmann, Christina E Herkt, Christine Schulz, Wilhelm Bertrams, Bernd Schmeck
Bacteria are able to secrete a variety of molecules via various secretory systems. Besides the secretion of molecules into the extracellular space or directly into another cell, Gram-negative bacteria can also form outer membrane vesicles (OMVs). These membrane vesicles can deliver their cargo over long distances, and the cargo is protected from degradation by proteases and nucleases. Legionella pneumophila (L. pneumophila) is an intracellular, Gram-negative pathogen that causes a severe form of pneumonia. In humans, it infects alveolar macrophages, where it blocks lysosomal degradation and forms a specialized replication vacuole...
February 22, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28276012/isolation-of-contact-sites-between-inner-and-outer-mitochondrial-membranes
#4
Max Harner
Mitochondria are essential organelles of all eukaryotic cells. They perform a plethora of important metabolic functions and have a highly complex architecture that differs drastically between different cells and tissues. Mitochondria are delimited from the cytosol by the mitochondrial envelope that consists of the outer membrane and the inner membrane. The inner membrane is subdivided into the inner boundary membrane that runs parallel to the outer membrane and the crista membrane. Both sections of the inner membrane are linked by crista junctions...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28274844/phosphatidylserine-lipids-and-membrane-order-precisely-regulate-the-activity-of-polybia-mp1-peptide
#5
Dayane S Alvares, João Ruggiero Neto, Ernesto E Ambroggio
Polybia-MP1 (IDWKKLLDAAKQIL-NH2) is a lytic peptide from the Brazilian wasp venom with known anti-cancer properties. Previous evidence indicates that phosphatidylserine (PS) lipids are relevant for the lytic activity of MP1. In agreement with this requirement, phosphatidylserine lipids are translocated to the outer leaflet of cells, and are available for MP1 binding, depending on the presence of liquid-ordered domains. Here, we investigated the effect of PS on MP1 activity when this lipid is reconstituted in membranes of giant or large liposomes with different lipid-phase states...
March 6, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28272393/experimental-vaccine-induces-th1-driven-immune-responses-and-resistance-to-neisseria-gonorrhoeae-infection-in-a-murine-model
#6
Y Liu, L A Hammer, W Liu, M M Hobbs, R A Zielke, A E Sikora, A E Jerse, N K Egilmez, M W Russell
Female mice were immunized intravaginally with gonococcal outer membrane vesicles (OMVs) plus microencapsulated interleukin-12 (IL-12), and challenged using an established model of genital infection with Neisseria gonorrhoeae. Whereas sham-immunized and control animals cleared the infection in 10-13 days, those immunized with OMV plus IL-12 cleared infection with homologous gonococcal strains in 6-9 days. Significant protection was also seen after challenge with antigenically distinct strains of N. gonorrhoeae, and protective anamnestic immunity persisted for at least 6 months after immunization...
March 8, 2017: Mucosal Immunology
https://www.readbyqxmd.com/read/28255538/porphyromonas-gingivalis-derived-outer-membrane-vesicles-promote-calcification-of-vascular-smooth-muscle-cells-through-erk1-2-runx2
#7
Wen Wei Yang, Bin Guo, Wen Yuan Jia, Yue Jia
The outer membrane vesicle (OMV) derived from Porphyromonas gingivalis plays an essential role in causing inflammation which, in turn, plays an important part in the pathogenesis of cardiovascular diseases such as atherosclerosis and thromboembolism. However, the contribution of oral bacteria to vascular calcification is yet to be determined. Here, we evaluated the effect of OMV on vascular smooth muscle cell (VSMC) calcification both in vitro and ex vivo. We established a reproducible P. gingivalis OMV-induced differentiation and calcification model of VSMCs in vitro...
December 2016: FEBS Open Bio
https://www.readbyqxmd.com/read/28246335/dynamic-regulation-of-extracellular-atp-in-escherichia-coli
#8
Cora Lilia Alvarez, Gerardo Corradi, Natalia Lauri, Irene Marginedas-Freixa, María Florencia Leal Denis, Nicolás Enrique, Sabina María Mate, Verónica Milesi, Mariano Anibal Ostuni, Vanesa Herlax, Pablo J Schwarzbaum
We studied the kinetics of extracellular ATP (ATPe) in Escherichia coli , and their outer membrane vesicles (OMVs) stimulated with amphipatic peptides melittin (MEL) and mastoparan 7 (MST7). Real time luminometry was used to measure ATPe kinetics, ATP release and ATPase activity. The latter was also determined by following [(32)P]Pi released from [γ-(32)P]ATP. E. coli was studied alone, coincubated with Caco-2 cells or in rat jejunum segments. In E. coli , addition of [γ-(32)P]ATP led to uptake and subsequent hydrolysis of ATPe...
February 28, 2017: Biochemical Journal
https://www.readbyqxmd.com/read/28244215/investigation-of-horseradish-peroxidase-kinetics-in-an-organelle-like-environment
#9
Patric Baumann, Mariana Spulber, Ozana Fischer, Anja Car, Wolfgang Meier
In order to mimic cell organelles, artificial nanoreactors have been investigated based on polymeric vesicles with reconstituted channel proteins (outer membrane protein F) and coencapsulated enzymes horseradish peroxidase (HRP) along with a crowding agent (Ficoll or polyethylene glycol) inside the cavity. Importantly, the presence of macromolecules has a strong impact on the enzyme kinetics, but no influence on the integrity of vesicles up to certain concentrations. This particular design allows for the first time the determination of HRP kinetics inside nonreactors with crowded milieu...
February 28, 2017: Small
https://www.readbyqxmd.com/read/28243609/meta-analysis-of-pulmonary-transcriptomes-from-differently-primed-mice-identifies-molecular-signatures-to-differentiate-immune-responses-following-bordetella-pertussis-challenge
#10
René H M Raeven, Jeroen L A Pennings, Elly van Riet, Gideon F A Kersten, Bernard Metz
Respiratory infection with Bordetella pertussis leads to severe effects in the lungs. The resulting immunity and also immunization with pertussis vaccines protect against disease, but the induced type of immunity and longevity of the response are distinct. In this study the effects of priming, by either vaccination or infection, on a subsequent pathogen encounter were studied. To that end, three postchallenge transcriptome datasets of previously primed mice were combined and compared to the responses in unprimed control mice...
2017: Journal of Immunology Research
https://www.readbyqxmd.com/read/28221789/raman-spectroscopy-reveals-selective-interactions-of-cytochrome-c-with-cardiolipin-that-correlate-with-membrane-permeability
#11
Jay P Kitt, David A Bryce, Shelley D Minteer, Joel M Harris
Permeabilization of the outer mitochondrial membrane is an integral step in apoptosis. The resulting release of pro-apoptotic signaling proteins leads to cell destruction through activation of the cysteine-aspartic protease (caspase) cascade. However, the mechanism of outer mitochondrial membrane (OMM) permeabilization remains unclear. It was recently shown that cytochrome c can induce pore formation in cardiolipin-containing phospholipid membranes, leading to large dextran and protein permeability. In this work, the interaction of cytochrome c with cardiolipin-containing phospholipid vesicles, serving as models of the OMM, is investigated to probe cytochrome c-induced permeability...
March 7, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28216293/the-secrets-of-acinetobacter-secretion
#12
REVIEW
Brent S Weber, Rachel L Kinsella, Christian M Harding, Mario F Feldman
Infections caused by the bacterial pathogen Acinetobacter baumannii are a mounting concern for healthcare practitioners as widespread antibiotic resistance continues to limit therapeutic treatment options. The biological processes used by A. baumannii to cause disease are not well defined, but recent research has indicated that secreted proteins may play a major role. A variety of mechanisms have now been shown to contribute to protein secretion by A. baumannii and other pathogenic species of Acinetobacter, including a type II secretion system (T2SS), a type VI secretion system (T6SS), autotransporter, and outer membrane vesicles (OMVs)...
February 16, 2017: Trends in Microbiology
https://www.readbyqxmd.com/read/28215994/safe-recombinant-outer-membrane-vesicles-that-display-m2e-elicit-heterologous-influenza-protection
#13
Hannah C Watkins, C Garrett Rappazzo, Jaclyn S Higgins, Xiangjie Sun, Nicole Brock, Annie Chau, Aditya Misra, Joseph P B Cannizzo, Michael R King, Taronna R Maines, Cynthia A Leifer, Gary R Whittaker, Matthew P DeLisa, David Putnam
Recombinant, Escherichia coli-derived outer membrane vesicles (rOMVs), which display heterologous protein subunits, have potential as a vaccine adjuvant platform. One drawback to rOMVs is their lipopolysaccharide (LPS) content, limiting their translatability to the clinic due to potential adverse effects. Here, we explore a unique rOMV construct with structurally remodeled lipids containing only the lipid IVa portion of LPS, which does not stimulate human TLR4. The rOMVs are derived from a genetically engineered B strain of E...
February 16, 2017: Molecular Therapy: the Journal of the American Society of Gene Therapy
https://www.readbyqxmd.com/read/28202367/exosomes-therapy-delivery-tools-and-biomarkers-of-diseases
#14
REVIEW
Lucio Barile, Giuseppe Vassalli
Virtually all cells in the organism secrete extracellular vesicles (EVs), a heterogeneous population of lipid bilayer membrane-enclosed vesicles that transport and deliver payloads of proteins and nucleic acids to recipient cells, thus playing central roles in cell-cell communications. Exosomes, nanosized EVs of endosomal origin, regulate many pathophysiological processes including immune responses and inflammation, tumour growth, and infection. Healthy subjects and patients with different diseases release exosomes with different RNA and protein contents into the circulation, which can be measured as biomarkers...
February 12, 2017: Pharmacology & Therapeutics
https://www.readbyqxmd.com/read/28195220/induction-of-invertebrate-larval-settlement-different-bacteria-different-mechanisms
#15
Marnie L Freckelton, Brian T Nedved, Michael G Hadfield
Recruitment via settlement of pelagic larvae is critical for the persistence of benthic marine populations. For many benthic invertebrates, larval settlement occurs in response to surface microbial films. Larvae of the serpulid polychaete Hydroides elegans can be induced to settle by single bacterial species. Until now, only Pseudoalteromonas luteoviolacea had been subjected to detailed genetic and mechanistic studies. To determine if the complex structures, termed tailocins, derived from phage-tail gene assemblies and hypothesized to be the settlement cue in P...
February 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28170214/determinants-of-bh3-sequence-specificity-for-the-disruption-of-bcl-xl-cbid-complexes-in-membranes
#16
Kushal Kumar Das, Raed Shalaby, Ana J García-Sáez
The prosurvival Bcl-2 proteins exhibit a specific pattern of interactions with BH3-only proteins that determines the cellular dependence to apoptotic stress. This specificity is crucial for the development of BH3 mimetics, a class of anti-cancer molecules based on the BH3 domain with promising activity in clinical trials. Although complex formation mainly takes place in the mitochondrial outer membrane, most studies so far addressed the interaction between BH3 peptides and truncated Bcl-2 proteins in solution...
February 7, 2017: ACS Chemical Biology
https://www.readbyqxmd.com/read/28158302/host-cell-interactions-of-outer-membrane-vesicle-associated-virulence-factors-of-enterohemorrhagic-escherichia-coli-o157-intracellular-delivery-trafficking-and-mechanisms-of-cell-injury
#17
Martina Bielaszewska, Christian Rüter, Andreas Bauwens, Lilo Greune, Kevin-André Jarosch, Daniel Steil, Wenlan Zhang, Xiaohua He, Roland Lloubes, Angelika Fruth, Kwang Sik Kim, M Alexander Schmidt, Ulrich Dobrindt, Alexander Mellmann, Helge Karch
Outer membrane vesicles (OMVs) are important tools in bacterial virulence but their role in the pathogenesis of infections caused by enterohemorrhagic Escherichia coli (EHEC) O157, the leading cause of life-threatening hemolytic uremic syndrome, is poorly understood. Using proteomics, electron and confocal laser scanning microscopy, immunoblotting, and bioassays, we investigated OMVs secreted by EHEC O157 clinical isolates for virulence factors cargoes, interactions with pathogenetically relevant human cells, and mechanisms of cell injury...
February 2017: PLoS Pathogens
https://www.readbyqxmd.com/read/28144586/interaction-of-bacteroides-fragilis-toxin-with-outer-membrane-vesicles-reveals-new-mechanism-of-its-secretion-and-delivery
#18
Natalya B Zakharzhevskaya, Vladimir B Tsvetkov, Anna A Vanyushkina, Anna M Varizhuk, Daria V Rakitina, Victor V Podgorsky, Innokentii E Vishnyakov, Daria D Kharlampieva, Valentin A Manuvera, Fedor V Lisitsyn, Elena A Gushina, Vassili N Lazarev, Vadim M Govorun
The only recognized virulence factor of enterotoxigenic Bacteroides fragilis (ETBF) that accompanies bloodstream infections is the zinc-dependent non-lethal metalloprotease B. fragilis toxin (BFT). The isolated toxin stimulates intestinal secretion, resulting in epithelial damage and necrosis. Numerous publications have focused on the interrelation of BFT with intestinal inflammation and colorectal neoplasia, but nothing is known about the mechanism of its secretion and delivery to host cells. However, recent studies of gram-negative bacteria have shown that outer membrane vesicles (OMVs) could be an essential mechanism for the spread of a large number of virulence factors...
2017: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/28138018/cellular-uptake-of-clostridium-botulinum-c2-toxin-requires-acid-sphingomyelinase-activity
#19
Masahiro Nagahama, Masaya Takehara, Teruhisa Takagishi, Soshi Seike, Kazuaki Miyamoto, Keiko Kobayashi
Clostridium botulinum C2 toxin consists of an enzyme component (C2I) and a binding component (C2II). Activated C2II (C2IIa) binds to a cell receptor, giving rise to lipid raft-dependent oligomerization, and then it assembles with C2I. The whole toxin complex is then endocytosed into the cytosol, resulting in destruction of the actin cytoskeleton and cell rounding. Here, we showed that C2 toxin requires acid sphingomyelinase (ASMase) activity during internalization. In this study, inhibitors of ASMase and lysosomal exocytosis blocked C2 toxin-induced cell rounding...
January 30, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28119513/native-and-foreign-proteins-secreted-by-the-cupriavidus-metallidurans-type-ii-system-and-an-alternative-mechanism
#20
Houjuan Xu, Timothy P Denny
The type II secretion system (T2SS), which transports selected periplasmic proteins across the outer membrane, has rarely been studied in nonpathogens or in organisms classified as betaproteobacteria. Therefore, we studied Cupriavidus metallidurans (Cme), a facultative chemilithoautotroph. Gel analysis of extracellular proteins revealed no remarkable differences between wild type and T2SS mutants. However, enzyme assays revealed that native extracellular alkaline phosphatase is a T2SS substrate, because activity was 10-fold greater for wild-type than a T2SS mutant...
January 24, 2017: Journal of Microbiology and Biotechnology
keyword
keyword
99111
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"