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1.
Biochemistry (Mosc) ; 88(12): 2146-2156, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38462457

RESUMO

Coat proteins (CP) of the potato virus A virions (PVA) contain partially disordered N-terminal domains, which are necessary for performing vital functions of the virus. Comparative analysis of the structures of coat proteins (CPs) in the intact PVA virions and in the virus particles lacking N-terminal 32 amino acids (PVAΔ32) was carried out in this work based on the tritium planigraphy data. Using atomic-resolution structure of the potato virus Y potyvirus (PVY) protein, which is a homolog of the CP PVA, the available CP surfaces in the PVY virion were calculated and the areas of intersubunit/interhelix contacts were determined. For this purpose, the approach of Lee and Richards [Lee, B., and Richards, F. M. (1971) J. Mol. Biol., 55, 379-400] was used. Comparison of incorporation profiles of the tritium label in the intact and trypsin-degraded PVAΔ32 revealed position of the ΔN-peptide shielding the surface domain (a.a. 66-73, 141-146) and the interhelix zone (a.a. 161-175) of the PVA CP. Presence of the channels/cavities was found in the virion, which turned out to be partially permeable to tritium atoms. Upon removal of the ΔN-peptide, decrease in the label incorporation within the virion (a.a. 184-200) was also observed, indicating possible structural transition leading to the virion compactization. Based on the obtained data, we can conclude that part of the surface ΔN-peptide is inserted between the coils of the virion helix thus increasing the helix pitch and providing greater flexibility of the virion, which is important for intercellular transport of the viruses in the plants.


Assuntos
Proteínas do Capsídeo , Potyvirus , Proteínas do Capsídeo/metabolismo , Trítio/análise , Trítio/metabolismo , Proteólise , Simulação por Computador , Potyvirus/metabolismo , Vírion/metabolismo , Peptídeos/metabolismo
2.
Biochemistry (Mosc) ; 88(1): 119-130, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37068873

RESUMO

The amino acid sequences of the coat proteins (CPs) of the potexviruses potato virus X (PVX) and alternanthera mosaic virus (AltMV) share ~40% identity. The N-terminal domains of these proteins differ in the amino acid sequence and the presence of the N-terminal fragment of 28 residues (ΔN peptide) in the PVX CP. Here, we determined the effect of the N-terminal domain on the structure and physicochemical properties of PVX and AltMV virions. The circular dichroism spectra of these viruses differed significantly, and the melting point of PVX virions was 10-12°C higher than that of AltMV virions. Alignment of the existing high-resolution 3D structures of the potexviral CPs showed that the RMSD value between the Cα-atoms was the largest for the N-terminal domains of the two compared models. Based on the computer modeling, the ΔN peptide of the PVX CP is fully disordered. According to the synchrotron small-angle X-ray scattering (SAXS) data, the structure of CPs from the PVX and AltMV virions differ; in particular, the PVX CP has a larger portion of crystalline regions and, therefore, is more ordered. Based on the SAXS data, the diameters of the PVX and AltMV virions and helix parameters in solution were calculated. The influence of the conformation of the PVX CP N-terminal domain and its position relative to the virion surface on the virion structure was investigated. Presumably, an increased thermal stability of PVX virions vs. AltMV is provided by the extended N-terminal domain (ΔN peptide, 28 amino acid residues), which forms additional contacts between the adjacent CP subunits in the PVX virion.


Assuntos
Potexvirus , Potexvirus/química , Potexvirus/metabolismo , Proteínas do Capsídeo/metabolismo , Espalhamento a Baixo Ângulo , Difração de Raios X , Vírion/metabolismo
3.
Biochemistry (Mosc) ; 88(12): 2094-2106, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38462453

RESUMO

Neutrophils play a dual role in protecting the body. They are able to penetrate infected tissues and destroy pathogens there by releasing aggressive bactericidal substances. While into the surrounding tissues, the aggressive products secreted by neutrophils initiate development of inflammatory processes. Invasion of neutrophils into tissues is observed during the development of pneumonia in the patients with lung diseases of various etiologies, including acute respiratory distress syndrome caused by coronavirus disease. Synthetic corticosteroid hormone dexamethasone has a therapeutic effect in treatment of lung diseases, including reducing mortality in the patients with severe COVID-19. The acute (short-term) effect of dexamethasone on neutrophil adhesion to fibrinogen and concomitant secretion was studied. Dexamethasone did not affect either attachment of neutrophils to the substrate or their morphology. Production of reactive oxygen species (ROS) and nitric oxide (NO) by neutrophils during adhesion also did not change in the presence of dexamethasone. Dexamethasone stimulated release of metalloproteinases in addition to the proteins secreted by neutrophils during adhesion under control conditions, and selectively stimulated release of free amino acid hydroxylysine, a product of lysyl hydroxylase. Metalloproteinases play a key role and closely interact with lysyl hydroxylase in the processes of modification of the extracellular matrix. Therapeutic effect of dexamethasone could be associated with its ability to reorganize extracellular matrix in the tissues by changing composition of the neutrophil secretions, which could result in the improved gas exchange in the patients with severe lung diseases.


Assuntos
Pneumopatias , Neutrófilos , Humanos , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/metabolismo , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/farmacologia , Dexametasona/farmacologia , Dexametasona/metabolismo , Metaloproteases/metabolismo , Metaloproteases/farmacologia , Pneumopatias/metabolismo
4.
Biochemistry (Mosc) ; 87(4): 356-365, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35527374

RESUMO

2-Oxoacids are involved in a number of important metabolic processes and can be used as biomarkers in some human diseases. A new optimized method for quantification of 2,4-dinitrophenylhydrazine derivatives of 2-oxoacids using high-performance liquid chromatography was developed based on available techniques for quantification of 2-oxoacids in mammalian brain. The use of the 2,4-dinitrophenylhydrazine derivatives of 2-oxoacids was shown to be more advantageous in comparison with the previously used phenylhydrazine derivatives, due to a high chemical stability of the former. Here, we determined the concentrations of pyruvate, glyoxylate, 2-oxoglutarate, 2-oxomalonate, and 4-methylthio-2-oxobutyrate in the methanol/acetic acid extracts of the rat brain using the developed method, as well discussed the procedures for the sample preparation in analysis of mammalian brain extracts. The validation parameters of the method demonstrated that the quantification limits for each of the analyzed of 2-oxoacids was 2 nmol/mg tissue. The developed method facilitates identification of subtle changes in the tissue and cellular content of 2-oxoacids as (patho)physiological biomarkers of metabolism in mammalian tissues.


Assuntos
Cetoácidos , Ácido Pirúvico , Animais , Encéfalo , Cromatografia Líquida de Alta Pressão/métodos , Mamíferos , Ratos
5.
Biochemistry (Mosc) ; 86(2): 230-240, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33832421

RESUMO

Potato virus A (PVA) protein coat contains on its surface partially unstructured N-terminal domain of the viral coat protein (CP), whose structural and functional characteristics are important for understanding the mechanism of plant infection with this virus. In this work, we investigated the properties and the structure of intact PVA and partially trypsinized PVAΔ32 virions using small-angle X-ray scattering (SAXS) and complimentary methods. It was shown that after the removal of 32 N-terminal amino acids of the CP, the virion did not disintegrate and remained compact, but the helical pitch of the CP packing changed. To determine the nature of these changes, we performed ab initio modeling, including the multiphase procedure, with the geometric bodies (helices) and restoration of the PVA structure in solution using available high-resolution structures of the homologous CP from the PVY potyvirus, based on the SAXS data. As a result, for the first time, a low-resolution structure of the filamentous PVA virus, both intact and partially degraded, was elucidated under conditions close to natural. The far-UV circular dichroism spectra of the PVA and PVAΔ32 samples differed significantly in the amplitude and position of the main negative maximum. The extent of thermal denaturation of these samples in the temperature range of 20-55°C was also different. The data of transmission electron microscopy showed that the PVAΔ32 virions were mostly rod-shaped, in contrast to the flexible filamentous particles typical of the intact virus, which correlated well with the SAXS results. In general, structural analysis indicates an importance of the CP N-terminal domain for the vital functions of PVA, which can be used to develop a strategy for combating this plant pathogen.


Assuntos
Proteínas do Capsídeo/metabolismo , Potyvirus/ultraestrutura , Vírion/ultraestrutura , Proteínas do Capsídeo/ultraestrutura , Dicroísmo Circular , Microscopia Eletrônica de Transmissão , Potyvirus/metabolismo , Espalhamento a Baixo Ângulo , Vírion/metabolismo , Difração de Raios X
6.
Int J Syst Evol Microbiol ; 70(2): 849-856, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31793856

RESUMO

Borrelia species are vector-borne parasitic bacteria with unusual, highly fragmented genomes that include a linear chromosome and linear as well as circular plasmids that differ numerically between and within various species. Strain CA690T, which was cultivated from a questing Ixodes spinipalpis nymph in the San Francisco Bay area, CA, was determined to be genetically distinct from all other described species belonging to the Borrelia burgdorferi sensu lato complex. The genome, including plasmids, was assembled using a hybrid assembly of short Illumina reads and long reads obtained via Oxford Nanopore Technology. We found that strain CA690T has a main linear chromosome containing 902176 bp with a blast identity ≤91 % compared with other Borrelia species chromosomes and five linear and two circular plasmids. A phylogeny based on 37 single-copy genes of the main linear chromosome and rooted with the relapsing fever species Borrelia duttonii strain Ly revealed that strain CA690T had a sister-group relationship with, and occupied a basal position to, species occurring in North America. We propose to name this species Borrelia maritima sp. nov. The type strain, CA690T, has been deposited in two national culture collections, DSMZ (=107169) and ATCC (=TSD-160).


Assuntos
Grupo Borrelia Burgdorferi/classificação , Ixodes/microbiologia , Filogenia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , Grupo Borrelia Burgdorferi/isolamento & purificação , California , Cromossomos Bacterianos , DNA Bacteriano/genética , Plasmídeos , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
7.
Org Biomol Chem ; 18(42): 8702-8708, 2020 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-33084716

RESUMO

Here we report the Friedel-Crafts arylation of chlorofullerenes C60Cl6 and C70Cl8 with thiophene-based methyl esters. While C60Cl6 formed expected Cs-C60R5Cl products, C70Cl8 demonstrated a tendency for both substitution of chlorine atoms and addition of an extra thiophene unit, thus forming Cs-C70R8 and C1-C70R9H compounds. The synthesized water-soluble C60 and C70 fullerene derivatives with thiophene-based addends demonstrated high activity against a broad range of viruses, including human immunodeficiency virus, influenza virus, cytomegalovirus, and herpes simplex virus. The record activity of C70 fullerene derivatives against herpes simplex virus together with low toxicity in mice makes them promising candidates for the development of novel non-nucleoside antiherpetic drugs.


Assuntos
Fulerenos
8.
Int J Mol Sci ; 21(2)2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31963289

RESUMO

Neutrophils can phagocytose microorganisms and destroy them intracellularly using special bactericides located in intracellular granules. Recent evidence suggests that neutrophils can catch and kill pathogens extracellularly using the same bactericidal agents. For this, live neutrophils create a cytoneme network, and dead neutrophils provide chromatin and proteins to form neutrophil extracellular traps (NETs). Cytonemes are filamentous tubulovesicular secretory protrusions of living neutrophils with intact nuclei. Granular bactericides are localized in membrane vesicles and tubules of which cytonemes are composed. NETs are strands of decondensed DNA associated with histones released by died neutrophils. In NETs, bactericidal neutrophilic agents are adsorbed onto DNA strands and are not covered with a membrane. Cytonemes and NETs occupy different places in protecting the body against infections. Cytonemes can develop within a few minutes at the site of infection through the action of nitric oxide or actin-depolymerizing alkaloids of invading microbes. The formation of NET in vitro occurs due to chromatin decondensation resulting from prolonged activation of neutrophils with PMA (phorbol 12-myristate 13-acetate) or other stimuli, or in vivo due to citrullination of histones with peptidylarginine deiminase 4. In addition to antibacterial activity, cytonemes are involved in cell adhesion and communications. NETs play a role in autoimmunity and thrombosis.


Assuntos
Armadilhas Extracelulares/metabolismo , Animais , Humanos , Neutrófilos/metabolismo , Óxido Nítrico/metabolismo , Proteína-Arginina Desiminase do Tipo 4/metabolismo
10.
Mediators Inflamm ; 2018: 1574928, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29670459

RESUMO

In patients with reperfusion after ischemia and early development of diabetes, neutrophils can attach to blood vessel walls and release their aggressive bactericide agents, which damage the vascular walls. Insulin and 17ß-estradiol (E2) relieve the vascular complications observed in metabolic disorders. In contrast, glucagon plays an essential role in the pathophysiology of diabetes. We studied the effect of hormones on neutrophil secretion during adhesion to fibronectin. Amino acid analysis revealed that proteins secreted by neutrophils are characterized by a stable amino acid profile enriched with glutamate, leucine, lysine, and arginine. The total amount of secreted proteins defined as the sum of detected amino acids was increased in the presence of insulin and reduced in the presence of glucagon. E2 did not affect the amount of protein secretion. Proteome analysis showed that in the presence of insulin and E2, neutrophils secreted metalloproteinases MMP-9 and MMP-8 playing a key role in modulation of the extracellular matrix. In contrast, glucagon induced the secretion of cathepsin G, a key bactericide protease of neutrophils. Cathepsin G can promote the development of vascular complications because of its proinflammatory activity and ability to stimulate neutrophil adhesion via the proteolysis of surface receptors.


Assuntos
Catepsina G/metabolismo , Glucagon/farmacologia , Insulina/farmacologia , Metaloproteases/metabolismo , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Células Cultivadas , Fibronectinas/metabolismo , Humanos , Espectrometria de Massas , Microscopia Eletrônica de Varredura
11.
Int J Syst Evol Microbiol ; 67(10): 3872-3876, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28884668

RESUMO

The diversity of Borrelia species discovered in California appears to be particularly high. A divergent group of Borrelia strains collected from Ixodes ticks in California was described by Postic and co-workers and designated 'genomospecies 2' (Postic D, Garnier M, Baranton G. Int J Med Microbiol 2007;297:263-271; Postic D, Ras NM, Lane RS, Hendson M, Baranton G. J Clin Microbiol 1998;36:3497-3504). We performed multilocus sequence analysis (MLSA) using eight housekeeping loci (clpA, clpX, nifS, pepX, pyrG, recG, rplB and uvrA) on 12 strains of this Borreliagenospecies to confirm that these strains form a distinct group within the Borreliaburgdorferi s. l. complex (Margos G, Hojgaard A, Lane RS, Cornet M, Fingerle V et al.Ticks Tick Borne Dis 2010;1:151-158). Phylogenetic and genetic distance analyses based on sequences of the MLSA housekeeping genes corroborated the distinctness of this group; genetic distances to all other members of the B. burgdorferi s.l. complex were 96 % or lower. We propose the name Borrelia lanei sp. nov. for this genospecies in honor of Professor Robert S. Lane, University of California Berkeley, for his contributions to Borrelia and tick research. The type strain for Borrelia lanei sp. nov., strain CA28-91T, has been deposited to two culture collections (=DSM 17992T=CIP 109135T).


Assuntos
Grupo Borrelia Burgdorferi/classificação , Ixodes/microbiologia , Filogenia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , Grupo Borrelia Burgdorferi/genética , Grupo Borrelia Burgdorferi/isolamento & purificação , California , DNA Bacteriano/genética , Genes Bacterianos , Tipagem de Sequências Multilocus , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
12.
Biol Lett ; 13(3)2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28275166

RESUMO

Group size predicts brain size in primates and some other mammal groups, but no such relationship has been found in birds. Instead, stable pair-bonding and bi-parental care have been identified as correlates of larger brains in birds. We investigated the relationship between brain size and social system within the family Picidae, using phylogenetically controlled regression analysis. We found no specific effect of duration or strength of pair-bonds, but brain sizes were systematically smaller in species living in long-lasting social groups of larger sizes. Group-living may only present a cognitive challenge in groups in which members have individually competitive relationships; we therefore propose that groups functioning for cooperative benefit may allow disinvestment in expensive brain tissue.


Assuntos
Aves/anatomia & histologia , Aves/fisiologia , Encéfalo/anatomia & histologia , Comportamento Social , Animais , Tamanho do Órgão , Ligação do Par , Filogenia
13.
Mediators Inflamm ; 2017: 4308684, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28740333

RESUMO

Neutrophils play an essential role in innate immunity due to their ability to migrate into infected tissues and kill microbes with bactericides located in their secretory granules. Neutrophil transmigration and degranulation are tightly regulated by actin cytoskeleton. Invading pathogens produce alkaloids that cause the depolymerization of actin, such as the mold alkaloid cytochalasin D. We studied the effect of cytochalasin D on the morphology and secretion of fMLP-, LPS-, or PMA-stimulated human neutrophils upon adhesion to fibronectin. Electron microscopy showed that the morphology of the neutrophils adherent to fibronectin in the presence of various stimuli differed. But in the presence of cytochalasin D, all stimulated neutrophils exhibited a uniform nonspread shape and developed thread-like membrane tubulovesicular extensions (cytonemes) measuring 200 nm in diameter. Simultaneous detection of neutrophil secretory products by mass spectrometry showed that all tested stimuli caused the secretion of MMP-9, a key enzyme in the neutrophil migration. Cytochalasin D impaired the MMP-9 secretion but initiated the release of cathepsin G and other granular bactericides, proinflammatory agents. The release of bactericides apparently occurs through the formation, shedding, and lysis of cytonemes. The production of alkaloids which modify neutrophil responses to stimulation via actin depolymerization may be part of the strategy of pathogen invasion.


Assuntos
Citocalasina D/farmacologia , Fibronectinas/metabolismo , Lipopolissacarídeos/farmacologia , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Acetato de Tetradecanoilforbol/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Catepsina G/metabolismo , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Metaloproteinase 9 da Matriz/metabolismo , Neutrófilos/metabolismo , Tiazolidinas/farmacologia
14.
Int J Syst Evol Microbiol ; 66(3): 1447-1452, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26813420

RESUMO

Two species of the genus Borrelia, Borrelia bissettiae sp. nov. and Borrelia californiensis sp. nov., were first described by Postic and co-workers on the basis of genetic analyses of several loci. Multilocus sequence analysis of eight housekeeping loci confirmed that these two Borrelia genomospecies are distinct members of the Borrelia burgdorferi sensu lato complex. B. bissettiae sp. nov. was initially described in transmission cycles involving Neotoma fuscipes wood rats and Ixodes pacificus ticks in California, and Neotoma mexicana and Ixodes spinipalpis in Colorado. The preferred host of B. californiensis sp. nov. appears to be the California kangaroo rat, Dipodomys californicus; Ixodes jellisoni, I. spinipalipis and I. pacificus ticks are naturally infected with it. Thus, the ecological associations of the two genomospecies and their genetic distance from all other known Borrelia genomospecies species justify their description as separate genomospecies: B. bissettiae sp. nov. (type strain DN127T = DSM 17990T = CIP 109136T) and B. californiensis (type strain CA446T = DSM 17989T = ATCC BAA-2689T).

15.
Biol Cell ; 107(5): 144-58, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25655190

RESUMO

BACKGROUND INFORMATION: In a previous study, we demonstrated that human neutrophils can develop membrane tubulovesicular extensions (TVEs) that are 160-250 nm in width and several micrometres long. These extensions, or cytonemes, are capable of establishing long-range contacts with other cells or bacteria. Cytonemes consist of membrane tubules and vesicles of a uniform diameter aligned in a row. The mechanism of membrane tubulation/vesiculation to form cytonemes remains unknown. Upon endocytosis, the GTPase dynamin and an intact actin cytoskeleton are required for endocytic vesicles scission from the plasma membrane. RESULTS: We examined the effects of dynasore (a dynamin specific inhibitor), and of cytochalasin D and latrunculin A (actin cytoskeleton disruption agents), on cytoneme formation in neutrophils. Scanning and transmission electron microscopy were used to observe cytoneme formation. High-performance chromatography and mass spectrometry were used to estimate the protein composition of the cytonemes. In neutrophils, dynasore and cytochalasin D or latrunculin A initiated the formation of tubular cytonemes that were similar in diameter and composition. The formation of cytonemes in cells treated with cytochalasin D was accompanied by the appearance of tubular invaginations of the same diameter on the plasma membrane of neutrophils. The formation of dynasore- or cytochalasin D-induced cytonemes, however, was blocked by the nitric oxide (NO) synthases inhibitor l-NAME, indicating that NO is involved in cytoneme development. Proteome analysis indicated that dynasore- or cytochalasin D-induced cytonemes are secretory protrusions that contain neutrophil bactericides along with cytoplasmic proteins, such as glycolytic enzymes and actin cytoskeleton components. CONCLUSIONS: Inhibition of dynamin with dynasore or actin depolymerisation with cytochalasin D or latrunculin A might impair the membrane fusion/fission events that are required for the separation of secretory vesicles from the plasma membrane and from each other. As a result, the secretory process extends from the cells as membrane TVEs or cytonemes. Modification of secretion gives neutrophils the possibility to communicate with other cells over distance via highly adhesive cellular secretory protrusions (cytonemes). Cytonemes deliver their membrane-packed content exactly to the destination without dilution and without harm to the surrounding tissues.


Assuntos
Actinas/metabolismo , Membrana Celular/metabolismo , Dinaminas/metabolismo , Neutrófilos/metabolismo , Neutrófilos/ultraestrutura , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/ultraestrutura , Actinas/ultraestrutura , Animais , Adesão Celular/fisiologia , Membrana Celular/ultraestrutura , Extensões da Superfície Celular/metabolismo , Extensões da Superfície Celular/ultraestrutura , Dinaminas/ultraestrutura , Endocitose/fisiologia , Humanos , Microscopia Eletrônica de Transmissão/métodos
16.
Diagn Microbiol Infect Dis ; 108(2): 116102, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37984108

RESUMO

Nonfermenting gram-negative (NFGN) bacteria were isolated from cystic fibrosis (CF) patients and subjected to susceptibility testing and whole-genome sequencing. Among 170 enrolled CF patients, 112 (65.9%) were colonized with at least 1 key NFGN species. The species-specific infection rate was highest for Pseudomonas aeruginosa (40.6%) followed by Stenotrophomonas maltophilia (14.1%), Achromobacter spp. (9.4%), and Burkholderia cepacia complex (Bcc, 8.2%) demonstrating a significant age-dependent increase for P. aeruginosa and Achromobacter spp., but not for S. maltophilia or Bcc. P. aeruginosa sequence types (STs) related to high-risk epidemic and global CF clones were carried by 12 (7.1%) and 13 (7.6%) patients, respectively. In total, 47% NFGN isolates, predominantly P. aeruginosa, harbored at least 1 plasmid-borne resistance gene; 5 ST235 isolates carried blaVIM2. Pathogenicity island-borne virulence genes were harbored by 9% NFGN isolates. These findings in conjunction with frequent early colonization by Bcc raised serious concerns regarding infection control in Russian CF centers.


Assuntos
Fibrose Cística , Stenotrophomonas maltophilia , Humanos , Antibacterianos/farmacologia , Fibrose Cística/complicações , Fibrose Cística/microbiologia , Farmacorresistência Bacteriana , Bactérias Gram-Negativas , Stenotrophomonas maltophilia/genética , Pseudomonas aeruginosa/genética
17.
Biochim Biophys Acta ; 1820(11): 1705-14, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22766193

RESUMO

BACKGROUND: Following adhesion to fibronectin neutrophils can develop membrane tubulovesicular extensions (TVEs) that can be 200nm wide and several cell diameters long. TVEs attach neutrophils to the other cells, substrata or bacteria over distance. To understand the physiological significance of TVEs we performed proteome analysis of TVE content in neutrophils plated to fibronectin in the presence of compounds known to induce TVE formation (nitric oxide donor diethylamine NONOate, 4-bromophenacyl bromide, cytochalasin D). METHODS: Development of TVEs was confirmed by scanning electron microscopy. TVEs were disrupted following removal of inductors and biochemical, high-performance liquid chromatography and mass spectrometry investigations were employed to characterize the proteins within the incubation media. RESULTS: TVE disruption released (a) the granular bactericides lactoferrin, lipocalin, myeloperoxidase, cathepsin G and defensins; (b) energy metabolism enzymes; (c) actin cytoskeleton proteins; (d) S100 proteins; and (e) annexin 1. CONCLUSIONS: The data confirm that TVEs represent a means of secretory bactericide trafficking, where the protrusions fuse with the plasma membrane upon neutrophil adhesion or extend from the cell surface when fusion is impaired. It is proposed that proteins abundantly presented in TVE (energy metabolism enzymes, actin cytoskeleton and S100 proteins, annexin 1) play an important role in fusion of TVE with the plasma membrane. GENERAL SIGNIFICANCE: Our study confirms TVEs as neutrophil secretory protrusions that make direct contacts with cells and bacteria over distance. The membrane-packed content and outstanding length of TVEs might allow targeted neutrophil secretion of aggressive bactericides over a long distance without dilution or injury to surrounding tissues.


Assuntos
Atividade Bactericida do Sangue , Membrana Celular/ultraestrutura , Neutrófilos/ultraestrutura , Proteoma/química , Vesículas Secretórias/química , Transporte Biológico , Adesão Celular , Humanos , Microscopia Eletrônica de Varredura , Neutrófilos/química
18.
Appl Environ Microbiol ; 79(5): 1444-53, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23263953

RESUMO

Comparative analysis of ospC genes from 127 Borrelia burgdorferi sensu stricto strains collected in European and North American regions where Lyme disease is endemic and where it is not endemic revealed a close relatedness of geographically distinct populations. ospC alleles A, B, and L were detected on both continents in vectors and hosts, including humans. Six ospC alleles, A, B, L, Q, R, and V, were prevalent in Europe; 4 of them were detected in samples of human origin. Ten ospC alleles, A, B, D, E3, F, G, H, H3, I3, and M, were identified in the far-western United States. Four ospC alleles, B, G, H, and L, were abundant in the southeastern United States. Here we present the first expanded analysis of ospC alleles of B. burgdorferi strains from the southeastern United States with respect to their relatedness to strains from other North American and European localities. We demonstrate that ospC genotypes commonly associated with human Lyme disease in European and North American regions where the disease is endemic were detected in B. burgdorferi strains isolated from the non-human-biting tick Ixodes affinis and rodent hosts in the southeastern United States. We discovered that some ospC alleles previously known only from Europe are widely distributed in the southeastern United States, a finding that confirms the hypothesis of transoceanic migration of Borrelia species.


Assuntos
Alelos , Antígenos de Bactérias/genética , Proteínas da Membrana Bacteriana Externa/genética , Borrelia burgdorferi/genética , Ixodes/microbiologia , Roedores/microbiologia , Animais , Borrelia burgdorferi/isolamento & purificação , DNA Bacteriano/química , DNA Bacteriano/genética , Europa (Continente) , Variação Genética , Genótipo , Humanos , Dados de Sequência Molecular , América do Norte , Análise de Sequência de DNA
19.
Membranes (Basel) ; 13(1)2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36676883

RESUMO

Topological rearrangements of biological membranes, such as fusion and fission, often require a sophisticated interplay between different proteins and cellular membranes. However, in the case of fusion proteins of enveloped viruses, even one molecule can execute membrane restructurings. Growing evidence indicates that matrix proteins of enveloped viruses can solely trigger the membrane bending required for another crucial step in virogenesis, the budding of progeny virions. For the case of the influenza A virus matrix protein M1, different studies report both in favor and against M1 being able to produce virus-like particles without other viral proteins. Here, we investigated the physicochemical mechanisms of M1 membrane activity on giant unilamellar vesicles of different lipid compositions using fluorescent confocal microscopy. We confirmed that M1 predominantly interacts electrostatically with the membrane, and its ability to deform the lipid bilayer is non-specific and typical for membrane-binding proteins and polypeptides. However, in the case of phase-separating membranes, M1 demonstrates a unique ability to induce macro-phase separation, probably due to the high affinity of M1's amphipathic helices to the raft boundary. Thus, we suggest that M1 is tailored to deform charged membranes with a specific activity in the case of phase-separating membranes.

20.
Evol Hum Sci ; 4: e39, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37588941

RESUMO

Mobility is a major mechanism of human adaptation, both in the deep past and in the present. Decades of research in the human evolutionary sciences have elucidated how much, how and when individuals and groups move in response to their ecology. Prior research has focused on small-scale subsistence societies, often in marginal environments and yielding small samples. Yet adaptive movement is commonplace across human societies, providing an opportunity to study human mobility more broadly. We provide a detailed, life-course structured demonstration, describing the residential mobility system of a historical population living between 1850 and 1950 in the industrialising Netherlands. We focus on how moves are patterned over the lifespan, attending to individual variation and stratifying our analyses by gender. We conclude that this population was not stationary: the median total moves in a lifetime were 10, with a wide range of variation and an uneven distribution over the life course. Mobility peaks in early adulthood (age 20-30) in this population, and this peak is consistent in all the studied cohorts, and both genders. Mobile populations in sedentary settlements provide a productive avenue for research on adaptive mobility and its relationship to human life history, and historical databases are useful for addressing evolutionarily motivated questions.

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