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1.
Georgian Med News ; (294): 103-108, 2019 Sep.
Artigo em Russo | MEDLINE | ID: mdl-31687959

RESUMO

The article overviews some issues of the severe course of tropical malaria. In addition to the analysis of the ongoing situation with malaria in Russia, a general clinical picture of the severe course of tropical malaria is discussed. The main part of the overview includes a detailed analysis of current data on the molecular genetic aspects of the erythrocytes' adhesion in the case of tropical malaria. The main elements involved in the process of binding red blood cells and, as a result, in the process of their adhesion to other cells of the human body were considered in detail. Data were studied and summarized not only on protein interactions between an infected red cell and its cellular environment, but also on the genetic characteristics of the parasite leading to similar molecular-biological processes. In addition to the study of protein PfEMP1 role which is nowadays well-considered in the literature, the most up-to-date but less reported data on erythrocyte adhesion proteins STEVOR and RIFIN were also included. The team of authors hopes that this publication will help to get a deeper insight into the problem of erythrocyte adhesion in the course of complicated malaria infection forms and to summarize some of the available data on this issue.


Assuntos
Antígenos de Protozoários/metabolismo , Membrana Eritrocítica/química , Membrana Eritrocítica/parasitologia , Eritrócitos/parasitologia , Malária Falciparum , Proteínas de Membrana/metabolismo , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/metabolismo , Antígenos de Protozoários/química , Humanos , Malária Falciparum/sangue , Proteínas de Membrana/química , Plasmodium falciparum/fisiologia , Proteínas de Protozoários/química , Federação Russa
2.
Anal Chim Acta ; 1080: 189-195, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31409469

RESUMO

Direct and absolute analysis of microRNAs (miRNAs) in complex media (e.g., human serum) is still a big challenge due to the issues with off-analyte absorption, low sensitivity and specificity. In this work, we have fabricated the erythrocyte membrane-biointerfaced spherical nucleic acids (EMSNAs) for miRNA assay, which not only enables tailor-engineered signal amplification but also exhibits anti-interference property. As a consequence, it is possible to achieve a single-step quantification of miRNAs in complex media without the process of enzymatic amplification, which can vastly simplify the detection procedure. Experimental results reveal that the assay permits ultrasensitive quantification of miR-141, with a limit of detection down to 33.9 aM, and show a high selectivity for discriminating miR-200 family members. More importantly, the assay enables robust miRNA analysis in human serum and can accurately differentiate lung cancer patients and prostate cancer patients from healthy donors. Its performance may satisfy the requirements for direct, rapid, sensitive and specific early diagnosis of cancer, signifying its great potential in clinical diagnostics.


Assuntos
Sondas de DNA/química , Membrana Eritrocítica/química , Corantes Fluorescentes/química , MicroRNAs/sangue , Animais , Carbocianinas/química , Sondas de DNA/genética , Ouro/química , Humanos , Limite de Detecção , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Masculino , Camundongos Endogâmicos BALB C , MicroRNAs/genética , Nanoestruturas/química , Hibridização de Ácido Nucleico , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/genética , Espectrometria de Fluorescência/métodos
3.
Biochim Biophys Acta Proteins Proteom ; 1867(11): 140267, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31470132

RESUMO

Spectrin, the major protein component of the erythrocyte membrane skeleton has chaperone like activity and is known to bind membrane phospholipids and hemoglobin. We have probed the chaperone activity of spectrin in presence of hemoglobin and phospholipid SUVs of different compositions to elucidate the effect of phospholipid/hemoglobin binding on chaperone function. It is seen that spectrin displays a preference for hemoglobin over other substrates leading to a decrease in chaperone activity in presence of hemoglobin. A competition is seen to exist between phospholipid binding and chaperone function of spectrin, in a dose dependent manner with the greatest extent of decrease being seen in case of phospholipid vesicles containing aminophospholipids e.g. PS and PE which may have implications in diseases like hereditary spherocytosis where mutation in spectrin is implicated in its detachment from cell membrane. To gain a clearer understanding of the chaperone like activity of spectrin under in-vivo like conditions we have investigated the effect of macromolecular crowders as well as phosphorylation and glycation states on chaperone activity. It is seen that the presence of non-specific, protein and non-protein macromolecular crowders do not appreciably affect chaperone function. Phosphorylation also does not affect the chaperone function unlike glycation which progressively diminishes chaperone activity. We propose a model where chaperone clients adsorb onto spectrin's surface and processes that bind to and occlude these surfaces decrease chaperone activity.


Assuntos
Membrana Eritrocítica/química , Hemoglobinas/química , Chaperonas Moleculares/química , Espectrina/química , Animais , Bovinos , Membrana Eritrocítica/metabolismo , Hemoglobinas/metabolismo , Chaperonas Moleculares/metabolismo , Fosfolipídeos/química , Fosfolipídeos/metabolismo , Ovinos , Espectrina/metabolismo
4.
Food Chem Toxicol ; 131: 110553, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31163221

RESUMO

Ginseng and its active gradient, ginsenoside Rg3 (Rg3), are widely used for a variety of health benefits, but concerns over their misuses are increasing. Previously, it has been reported that Rg3 can cause hemolysis, but its health outcome remains unknown. Here, we demonstrated that Rg3 could promote the procoagulant activity of erythrocytes through the process of hemolysis, ultimately leading to increased thrombosis. In freshly isolated human erythrocytes, Rg3 caused pore formation and fragmentation of the erythrocyte membrane. Confocal microscopy observation and flow cytometric analysis revealed that remnant erythrocyte fragments after the exposure to Rg3 expressed phosphatidylserine (PS), which can promote blood coagulation through providing assembly sites for coagulation complexes. Rat in vivo experiments further confirmed that intravenous administration of Rg3 produced PS-bearing erythrocyte debris and increased thrombosis. Collectively, we demonstrated that Rg3 could induce the procoagulant activity of erythrocytes by generating PS-bearing erythrocyte debris through hemolysis, which might provoke thrombosis.


Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Ginsenosídeos/efeitos adversos , Hemólise/efeitos dos fármacos , Trombose/induzido quimicamente , Animais , Membrana Eritrocítica/química , Membrana Eritrocítica/efeitos dos fármacos , Eritrócitos/metabolismo , Eritrócitos/patologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Masculino , Fosfatidilserinas/química , Ratos Sprague-Dawley
5.
Chem Commun (Camb) ; 55(46): 6523-6526, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31099806

RESUMO

Cu2-xSe nanoparticles (Cu2-xSeNPs) were camouflaged with a red blood cell membrane (RBC) to create nanoparticles with improved biocompatibility, longer blood retention times, excellent absorption properties, superior photothermal conversion efficiency (67.2%) and singlet oxygen production capabilities for the synergistic photothermal and photodynamic therapy of cancer in the second near-infrared (NIR-II) window.


Assuntos
Antineoplásicos/uso terapêutico , Membrana Eritrocítica/química , Nanopartículas/uso terapêutico , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/síntese química , Antineoplásicos/efeitos da radiação , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Cobre/química , Temperatura Alta , Humanos , Hipertermia Induzida/métodos , Raios Infravermelhos , Camundongos , Nanopartículas/química , Nanopartículas/efeitos da radiação , Nanopartículas/toxicidade , Fotoquimioterapia/métodos , Células RAW 264.7 , Selênio/química , Oxigênio Singlete/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Biosens Bioelectron ; 135: 216-223, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31026776

RESUMO

Fibrinogen, which is a glycoprotein that circulates in the blood, plays various important biological roles, e.g., in blood coagulation, fibroblast proliferation, angiogenesis, and wound healing. Abnormal levels of fibrinogen in plasma have been identified as a key biomarker of a variety of disorders from cardiovascular diseases to hemophilia. Therefore, the development of a quantitative assay for fibrinogen in the blood has emerged as an important issue for the prevention and diagnosis of these diseases. Meanwhile, it is well known that erythrocytes can selectively capture fibrinogen because of the fibrinogen receptor expressed on their plasma membrane. Inspired by these biological interactions, herein, we devised an erythrocyte membrane (EM)-blanketed biosensor based on localized surface plasmon resonance (LSPR) for highly sensitive detection of fibrinogen. By placing the EM onto a nanoparticle-on-substrate, we enhanced the LSPR signal, achieving highly sensitive and selective detection of fibrinogen. We demonstrated that fibrinogen detection is possible over a wide concentration range, 0.001-5.000 mg/mL, which can cover normal and pathological blood fibrinogen levels. In addition, it was verified that the biosensor selectively detects fibrinogen in comparison with other human-blood-plasma components. The nanoplasmonic sensor blanketed with the EM opens up new opportunities for the development of a robust fibrinogen-sensing technology.


Assuntos
Membrana Eritrocítica/química , Fibrinogênio/análise , Ressonância de Plasmônio de Superfície/métodos , Desenho de Equipamento , Ouro/química , Humanos , Limite de Detecção , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Ressonância de Plasmônio de Superfície/instrumentação
7.
Colloids Surf B Biointerfaces ; 180: 23-30, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31022554

RESUMO

For miltefosine (MIL), a zwitterionic alkylphospholipid approved for leishmaniasis treatment, the mechanism of action is not well established. Electron paramagnetic resonance (EPR) spectroscopy has indicated that the interaction of MIL with membrane proteins has similarities to that of ionic surfactants. A general concern about leishmanicides is their high hemolytic potential, so we decided to compare the interactions of MIL and three ionic surfactants with the erythrocyte membrane. Measurements with two different spin labels indicated that the surfactants sodium dodecyl sulfate (SDS, anionic), cetyltrimethylammonium chloride (CTAC, cationic) and N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (HPS, zwitterionic) as well as MIL increase the dynamics of erythrocyte membrane proteins in a concentration-dependent manner. SDS produced the smallest increases in protein dynamics and was also the least hemolytic for measurements in PBS and in whole blood. Spin label EPR measurements performed directly in the blood plasma detected increased albumin stiffness caused by 2.5 mM SDS due to electrostatic/hydrophobic interactions. For 10 mM concentrations of the compounds, the EPR spectra showed a fraction of albumin with greater mobility and another with the same as that of the untreated plasma. The zwitterionic compounds MIL and HPS did not present significant differences in this study.


Assuntos
Antiprotozoários/farmacologia , Membrana Eritrocítica/efeitos dos fármacos , Proteínas de Membrana/química , Fosforilcolina/análogos & derivados , Animais , Antiprotozoários/química , Compostos de Bis-Trimetilamônio/química , Compostos de Bis-Trimetilamônio/farmacologia , Bovinos , Relação Dose-Resposta a Droga , Espectroscopia de Ressonância de Spin Eletrônica , Membrana Eritrocítica/química , Hemólise/efeitos dos fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Cinética , Micelas , Fosforilcolina/química , Fosforilcolina/farmacologia , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/farmacologia , Soroalbumina Bovina/química , Dodecilsulfato de Sódio/química , Dodecilsulfato de Sódio/farmacologia , Marcadores de Spin , Eletricidade Estática
8.
Drug Test Anal ; 11(8): 1231-1237, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30950199

RESUMO

The erythrocyte membrane is composed of a phospholipid bilayer, which is known to undergo physicochemical changes during storage at low temperatures. This study was conducted to identify marker phospholipids that indicate alteration during deep-frozen storage and to determine the amount of marker phospholipids. Our research suggested a method to detect phospholipids by profiling analysis of thermally injured red blood cells (RBCs) without protecting agents. Human blood was stored at -80°C for 72 days. The RBC membrane phospholipids were extracted through a modified Bligh and Dyer method. Six selected phospholipids were analyzed and quantified using liquid chromatography-tandem mass spectrometry, and an in vitro model system was developed. The intracellular level of N-nervonoyl-D-erythro-sphingosylphosphorylcholine significantly increased in the thermally injured RBCs, and multiple biomarker candidates were evaluated by profiling analysis and mass spectrometry technology for targeted metabolomics.


Assuntos
Preservação de Sangue/métodos , Criopreservação/métodos , Eritrócitos/química , Fosfolipídeos/análise , Membrana Eritrocítica/química , Eritrócitos/citologia , Humanos , Fosforilcolina/análogos & derivados , Fosforilcolina/análise , Esfingosina/análogos & derivados , Esfingosina/análise
9.
Artif Cells Nanomed Biotechnol ; 47(1): 989-996, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30873877

RESUMO

Nano-erythrocyte coating has been developed as an interesting biomimetic platform to provide hybrid nano-carriers with innate functions to target liver cancer. This goal was achieved by coating nano-erythrocyte membranes (NEMs) onto 5-fluorouracil (5-FU)-loaded liposomes (LPs) to produce NEM-5-FU-LPs. This framework is used to promote the escape of 5-FU-LPs from degradation during systemic circulation. NEMs were obtained by hypotonic lysis of erythrocytes to produce ghost erythrocytes (GEs) followed by extrusion through polycarbonate membranes. Chimeric NEM-5-FU-LPs were fabricated via the fusion of NEMs and artificial LPs. The resultant chaperoned LPs were characterized based on particle size, morphology, entrapment efficiency (EE %), stability, protein content and phosphatidylserine exposure and their in vitro release profiles and cytotoxic efficacy were also determined. The present results revealed that 5-FU-LPs, NEM-5-FU and NEM-5-FU-LPs exhibited nanosize, spherical shapes and unimodal size distributions <0.3. In addition, the vesicles presented a zeta potential with EE% of 24.6-30.7% and an appropriate stability for 3 weeks. NEM-5-FU-LPs retained the erythrocyte membrane proteins as confirmed by PAGE and displayed a sustained release profile up to 48 h when compared to NEM-5-FU and the 5-FU solution. Moreover, hybrid NEM-5-FU-LPs induced a late cytotoxic effect after 48 h compared to the other formulations. Thus, mantling of 5-FU-LPs by NEMs could enhance vesicle controllability and their targetability to liver cancer cells.


Assuntos
Biomimética/métodos , Carcinoma Hepatocelular/patologia , Sistemas de Liberação de Medicamentos/métodos , Membrana Eritrocítica/química , Fluoruracila/química , Lipossomos/química , Neoplasias Hepáticas/patologia , Animais , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular , Preparações de Ação Retardada , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Fluoruracila/farmacocinética , Humanos , Lipossomos/farmacocinética , Neoplasias Hepáticas/metabolismo , Tamanho da Partícula , Ratos , Propriedades de Superfície
10.
Artif Cells Nanomed Biotechnol ; 47(1): 968-979, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30880468

RESUMO

Conventional anti-tumour chemotherapy is facing the challenges of poor specificity, high toxicity and drug resistance. Tumour microenvironment (TME) plays a critical role in tumour development and drug resistance. To address this problem, we constructed a novel anti-tumour nanoparticle platform RBC@BPQDs-DOX/KIR, black phosphorus nanoparticle quantum dots (BPQDs) with one of the chemotherapeutics (doxorubicin, DOX) and an anti-inflammatory traditional Chinese medicine active component (Kirenol, KIR). Red blood cell membrane (RBCm) vesicles were used as the shell to envelop several nanocores. The combination of DOX and KIR may promote therapeutic efficacy, at which the anti-apoptotic effect of the tumour cells was inhibited (by downregulating Bcl-2 and upregulating Bax) and the tumour progression-related inflammatory factors, such as tumour necrosis factor α (TNF-α) and interleukin-6 (IL-6) were downregulated. Furthermore, TME was remodelled and the anti-tumour effect of DOX was magnified. RBCm imparts high biocompatibility and enhanced permeability and retention (EPR) effects to RBC@BPQDs-DOX/KIR, thus enhancing its tumour passively targetability. Overall, the RBCm-camouflaged drug delivery system RBC@BPQDs-DOX/KIR as a promising therapy for targeted chemotherapeutics and anti-inflammatory therapeutics may provide a specific and highly efficient anti-tumour treatment choice.


Assuntos
Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Membrana Eritrocítica/química , Fósforo/química , Pontos Quânticos/química , Animais , Anti-Inflamatórios/farmacocinética , Antineoplásicos/farmacocinética , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Diterpenos/química , Diterpenos/farmacocinética , Diterpenos/farmacologia , Doxorrubicina/química , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Feminino , Humanos , Teste de Materiais , Camundongos , Distribuição Tecidual , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Biochim Biophys Acta Biomembr ; 1861(4): 768-775, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30659792

RESUMO

For its fundamental relevance, transport of water and glycerol across the erythrocyte membrane has long been investigated before and after the discovery of aquaporins (AQPs), the membrane proteins responsible for water and glycerol transport. AQP1 is abundantly expressed in the human erythrocyte for maintaining its hydrohomeostasis where AQP3 is also expressed (at a level ~30-folds lower than AQP1) facilitating glycerol transport. This research is focused on two of the remaining questions: How permeable is AQP3 to water? What is the glycerol-AQP3 affinity under near-physiological conditions? Through atomistic modelling and large-scale simulations, we found that AQP3 is two to three times more permeable to water than AQP1 and that the glycerol-AQP3 affinity is approximately 500/M. Using these computed values along with the data from the latest literature on AQP1 and on erythrocyte proteomics, we estimated the water and glycerol transport rates across the membrane of an entire erythrocyte. We used these rates to predict the time courses of erythrocyte swelling-shrinking in response to inward and outward osmotic gradients. Experimentally, we monitored the time course of human erythrocytes when subject to an osmotic or glycerol gradient with light scattering in a stopped-flow spectrometer. We observed close agreement between the experimentally measured and the computationally predicted time courses of erythrocytes, which corroborated our computational conclusions on the AQP3 water-permeability and the glycerol-AQP3 affinity.


Assuntos
Aquaporina 3/química , Membrana Eritrocítica/química , Glicerol/química , Aquaporina 3/metabolismo , Permeabilidade da Membrana Celular , Membrana Eritrocítica/metabolismo , Glicerol/metabolismo , Humanos
12.
Nanomedicine ; 16: 79-87, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30529792

RESUMO

The rationale for the design of drug delivery nanoparticles is traditionally based on co-solvent self-assembly following bottom-up approaches or in combination with top-down approaches leading to tailored physiochemical properties to regulate biological responses. However, the optimal design and control of material properties to achieve specific biological responses remain the central challenge in drug delivery research. Considering this goal, we herein designed discoidal polymeric particles (DPPs) whose surfaces are re-engineered with isolated red blood cell (RBC) membranes to tailor their pharmacokinetics. The RBC membrane-coated DPPs (RBC-DPPs) were found to be biocompatible in cell-based in vitro experiments and exhibited extended blood circulation half-life. They also demonstrated unique kinetics at later time points in a mouse model compared to that of bare DPPs. Our results suggested that the incorporation of biomimicry would enable the biomimetic particles to cooperate with systems in the body such as cells and biomolecules to achieve specific biomedical goals.


Assuntos
Biomimética/métodos , Polímeros/química , Animais , Sistemas de Liberação de Medicamentos/métodos , Membrana Eritrocítica/química , Eritrócitos , Feminino , Macrófagos , Camundongos , Camundongos Nus
13.
Colloids Surf B Biointerfaces ; 173: 742-750, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30384271

RESUMO

The interactions and the protective effect of epigallocatechin gallate (EGCG) on human erythrocytes (RBC) and molecular models of its membrane were investigated. The latter consisted of bilayers built- up of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representative of phospholipid classes located in the outer and inner monolayers of the human erythrocyte membrane, respectively. X-ray diffraction and differential scanning calorimetry experiments showed that EGCG induced significant structural and thermotropic perturbations in multilayers and vesicles of DMPC; however, these effects were not observed in DMPE. Fluorescence spectroscopy results revealed that EGCG produced alterations of the molecular dynamics at the level of the hydrophobic-hydrophilic interface in DMPC vesicles, and in isolated unsealed human erythrocyte membranes (IUM). EGCG also induced morphological alterations in RBC from their normal discoid form to echinocytes. These outcomes indicate that EGCG molecules were located in the outer monolayer of the erythrocyte membrane. The assessment of EGCG protective effect demonstrated that it inhibits the morphological alterations and lysis induced by HClO to human erythrocytes. The results obtained from this study suggest that the insertion of EGCG into the outer monolayer of the erythrocyte membrane might prevent the access and deleterious effects of oxidant molecules such as HClO and free radicals into the red cells, protecting them from oxidative damage.


Assuntos
Antioxidantes/farmacologia , Catequina/análogos & derivados , Membrana Eritrocítica/efeitos dos fármacos , Ácido Hipocloroso/antagonistas & inibidores , Oxidantes/antagonistas & inibidores , Antioxidantes/química , Catequina/química , Catequina/farmacologia , Dimiristoilfosfatidilcolina/química , Membrana Eritrocítica/química , Hemólise/efeitos dos fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Ácido Hipocloroso/farmacologia , Cinética , Bicamadas Lipídicas/química , Oxidantes/farmacologia , Fosfatidiletanolaminas/química , Espectrometria de Fluorescência , Termodinâmica
14.
Biochimie ; 156: 206-223, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30036605

RESUMO

Actinoporins constitute a unique class of pore-forming toxins found in sea anemones that being secreted as soluble monomers are able to bind and permeabilize membranes leading to cell death. The interest in these proteins has risen due to their high cytotoxicity that can be properly used to design immunotoxins against tumor cells and antigen-releasing systems to cell cytosol. In this work we describe a novel actinoporin produced by Anthopleura nigrescens, an anemone found in the Central American Pacific Ocean. Here we report the amino acid sequence of an actinoporin as deduced from cDNA obtained from total body RNA. The synthetic DNA sequence encoding for one cytolysin variant was expressed in BL21 Star (DE3) Escherichia coli and the protein purified by chromatography on CM Sephadex C-25 with more than 97% homogeneity as verified by MS-MS and HPLC analyses. This actinoporin comprises 179 amino acid residues, consistent with its observed isotope-averaged molecular mass of 19 661 Da. The toxin lacks Cys and readily permeabilizes erythrocytes, as well as L1210 cells. CD spectroscopy revealed that its secondary structure is dominated by beta structure (58.5%) with 5.5% of α-helix, and 35% of random structure. Moreover, binding experiments to lipidic monolayers and to liposomes, as well as permeabilization studies in vesicles, revealed that the affinity of this toxin for sphingomyelin-containing membranes is quite similar to sticholysin II (StII). Comparison by spectroscopic techniques and modeling the three-dimensional structure of nigrelysin (Ng) showed a high homology with StII but several differences were also detectable. Taken together, these results reinforce the notion that Ng is a novel member of the actinoporin pore-forming toxin (PFT) family with a HA as high as that of StII, the most potent actinoporin so far described, but with peculiar structural characteristics contributing to expand the understanding of the structure-function relationship in this protein family.


Assuntos
Permeabilidade da Membrana Celular/efeitos dos fármacos , Venenos de Cnidários , Membrana Eritrocítica , Membranas Artificiais , Anemone/química , Anemone/genética , Clonagem Molecular , Venenos de Cnidários/biossíntese , Venenos de Cnidários/química , Venenos de Cnidários/genética , Venenos de Cnidários/farmacologia , Membrana Eritrocítica/química , Membrana Eritrocítica/metabolismo , Humanos , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia
15.
Scanning ; 2018: 1810585, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30581527

RESUMO

The ability of membranes of native human red blood cells (RBCs) to bend into the cell to a depth comparable in size with physiological deformations was evaluated. For this, the methods of atomic force microscopy and atomic force spectroscopy were used. Nonlinear patterns of deep deformation (up to 600 nm) of RBC membranes were studied in normal state and under the action of modifiers: fixator (glutaraldehyde), natural oxidant (hemin), and exogenous intoxicator (zinc ions), in vitro. The experimental dependences of membrane bending for control RBC (normal) were approximated by the Hertz model to a depth up to 600 nm. The glutaraldehyde fixator and modifiers increased the absolute value of Young's modulus of membranes and changed the experimental dependences of probe indentation into the cells. Up to some depth h Hz, the force curves were approximated by the Hertz model, and for deeper indentations h > h Hz, the degree of the polynomial function was changed, the membrane stiffness increased, and the pattern of indentation became another and did not obey the Hertz model. Quantitative characteristics of nonlinear experimental dependences were calculated for deep bending of RBC membranes by approximating them by the degree polynomial function.


Assuntos
Membrana Eritrocítica/efeitos dos fármacos , Glutaral/farmacologia , Hemina/farmacologia , Zinco/farmacologia , Fenômenos Biomecânicos , Tampões (Química) , Cátions Bivalentes , Módulo de Elasticidade , Membrana Eritrocítica/química , Membrana Eritrocítica/ultraestrutura , Humanos , Microscopia de Força Atômica , Propriedades de Superfície
16.
Cell Physiol Biochem ; 51(4): 1544-1565, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30497064

RESUMO

BACKGROUND/AIMS: Red blood cells (RBC) have been shown to exhibit stable submicrometric lipid domains enriched in cholesterol (chol), sphingomyelin (SM), phosphatidylcholine (PC) or ganglioside GM1, which represent the four main lipid classes of their outer plasma membrane leaflet. However, whether those lipid domains co-exist at the RBC surface or are spatially related and whether and how they are subjected to reorganization upon RBC deformation are not known. METHODS: Using fluorescence and/or confocal microscopy and well-validated probes, we compared these four lipid-enriched domains for their abundance, curvature association, lipid order, temperature dependence, spatial dissociation and sensitivity to RBC mechanical stimulation. RESULTS: Our data suggest that three populations of lipid domains with decreasing abundance coexist at the RBC surface: (i) chol-enriched ones, associated with RBC high curvature areas; (ii) GM1/PC/chol-enriched ones, present in low curvature areas; and (iii) SM/PC/chol-enriched ones, also found in low curvature areas. Whereas chol-enriched domains gather in increased curvature areas upon RBC deformation, low curvature-associated lipid domains increase in abundance either upon calcium influx during RBC deformation (GM1/PC/chol-enriched domains) or upon secondary calcium efflux during RBC shape restoration (SM/PC/chol-enriched domains). Hence, abrogation of these two domain populations is accompanied by a strong impairment of the intracellular calcium balance. CONCLUSION: Lipid domains could contribute to calcium influx and efflux by controlling the membrane distribution and/or the activity of the mechano-activated ion channel Piezo1 and the calcium pump PMCA. Whether this results from lipid domain biophysical properties, the strength of their anchorage to the underlying cytoskeleton and/or their correspondence with inner plasma membrane leaflet lipids remains to be demonstrated.


Assuntos
Colesterol/análise , Membrana Eritrocítica/metabolismo , Eritrócitos/citologia , Gangliosídeo G(M1)/análise , Microdomínios da Membrana/metabolismo , Fosfatidilcolinas/análise , Fenômenos Biomecânicos , Forma Celular , Colesterol/metabolismo , Membrana Eritrocítica/química , Membrana Eritrocítica/ultraestrutura , Eritrócitos/química , Eritrócitos/metabolismo , Eritrócitos/ultraestrutura , Gangliosídeo G(M1)/metabolismo , Humanos , Canais Iônicos/metabolismo , Microdomínios da Membrana/química , Microdomínios da Membrana/ultraestrutura , Fosfatidilcolinas/metabolismo , ATPases Transportadoras de Cálcio da Membrana Plasmática/metabolismo
17.
Nutrients ; 10(11)2018 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-30453550

RESUMO

The fatty acid compositions of plasma lipids and cell membranes of certain tissues are modified by dietary fatty acid composition. Furthermore, many other factors (age, sex, ethnicity, health status, genes, and gene × diet interactions) affect the fatty acid composition of cell membranes or plasma lipid compartments. Therefore, it is of great importance to understand the complexity of mechanisms that may modify fatty acid compositions of plasma or tissues. We carried out an extensive literature survey of gene × diet interaction in the regulation of fatty acid compositions. Most of the related studies have been observational studies, but there are also a few intervention trials that tend to confirm that true interactions exist. Most of the studies deal with the desaturase enzyme cluster (FADS1, FADS2) in chromosome 11 and elongase enzymes. We expect that new genetic variants are being found that are linked with the genetic regulation of plasma or tissue fatty acid composition. This information is of great help to understanding the contribution of dietary fatty acids and their endogenic metabolism to the development of some chronic diseases.


Assuntos
Gorduras na Dieta/administração & dosagem , Membrana Eritrocítica/química , Ácidos Graxos/administração & dosagem , Biomarcadores/sangue , Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 11/metabolismo , Dieta , Membrana Eritrocítica/metabolismo , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos/sangue , Regulação da Expressão Gênica , Variação Genética , Humanos , Família Multigênica , Estudos Observacionais como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto
18.
Nat Commun ; 9(1): 4960, 2018 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-30470753

RESUMO

Extracellular vesicles (EVs) are widely studied regarding their role in cell-to-cell communication and disease, as well as for applications as biomarkers or drug delivery vehicles. EVs contain membrane and intraluminal proteins, affecting their structure and thereby likely their functioning. Here, we use atomic force microscopy for mechanical characterization of erythrocyte, or red blood cell (RBC), EVs from healthy individuals and from patients with hereditary spherocytosis (HS) due to ankyrin deficiency. While these EVs are packed with proteins, their response to indentation resembles that of fluid liposomes lacking proteins. The bending modulus of RBC EVs of healthy donors is ~15 kbT, similar to the RBC membrane. Surprisingly, whereas RBCs become more rigid in HS, patient EVs have a significantly (~40%) lower bending modulus than donor EVs. These results shed light on the mechanism and effects of EV budding and might explain the reported increase in vesiculation of RBCs in HS patients.


Assuntos
Membrana Eritrocítica/química , Eritrócitos/química , Vesículas Extracelulares/química , Esferocitose Hereditária/metabolismo , Membrana Eritrocítica/metabolismo , Eritrócitos/metabolismo , Vesículas Extracelulares/metabolismo , Humanos , Fluidez de Membrana , Microscopia de Força Atômica , Proteínas/metabolismo
19.
Ann Nutr Metab ; 73(4): 335-343, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30428475

RESUMO

BACKGROUND: Term infants can be categorized into 3 sub-groups: early term (37w0d to 38w6d), full term (39w0d to 40w6d), and late term (41w0d and beyond). However, the fatty acid composition among the 3 groups of term infants has not been investigated. The association between fatty acid composition and gestational period of term infants in Japan is unclear. METHODS: We assessed the fatty acid composition of maternal erythrocyte membranes in the third trimester and of cord erythrocyte membranes at birth in 212 healthy term Japanese infants using data from a prospective hospital-based cohort study. RESULTS: In maternal erythrocyte membranes, docosahexaenoic acid (DHA) levels and omega-3 index were significantly higher in the late-term group than in the early-term group. In cord erythrocyte membranes, DHA levels were not significantly different between the 3 groups; late-term infants showed significantly higher DHA/arachidonic acid (ARA) and lower 20: 3n-6 and ARA levels compared to early-term infants. Gestational period positively correlated with the DHA status in maternal and cord erythrocyte membranes. CONCLUSIONS: Fatty acid composition in maternal and cord erythrocyte membranes varies between early-, full-, and late-term infants, and the greater gestational period may contribute to the relatively high n-3 polyunsaturated fatty acids status in term infants. Furthermore, maternal DHA status in the third semester directly correlates with gestational period in pregnant Japanese women.


Assuntos
Membrana Eritrocítica/química , Ácidos Graxos/análise , Idade Gestacional , Adulto , Ácido Araquidônico/sangue , Estudos de Coortes , Dieta , Ácidos Docosa-Hexaenoicos/sangue , Ácidos Graxos/administração & dosagem , Ácidos Graxos Ômega-3/sangue , Feminino , Sangue Fetal , Humanos , Recém-Nascido , Recém-Nascido Prematuro/sangue , Japão , Gravidez , Terceiro Trimestre da Gravidez/sangue , Estudos Prospectivos
20.
J Helminthol ; 94: e17, 2018 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-30486910

RESUMO

The complex life cycle of Trichinella spiralis includes the migration of newborn larvae through the bloodstream to their encystment in muscle. The parasite establishes an intimate contact with the erythrocytes of the host both during the migration of the newborn larvae and when encysting, as this parasite causes intense vascularization in the muscle cell. The goal of this work was to study the effects of various concentrations of T. spiralis muscle larvae (ML) on erythrocyte membranes. The treatment was performed by incubating human erythrocytes with equal volume of different concentrations of ML for 30 minutes, with controlled agitation (37°C). The control erythrocytes (with no contact with the larvae) were incubated in the same way with an equal volume of physiological solution. To evaluate the alterations to the erythrocytes by the action of the larvae and in the respective controls, an Erythrocyte Rheometer and a Digital Image Analysis technique were used. The results indicated that when the larval concentration was higher, the aggregation and erythrocyte membrane alterations were also higher. Also, the erythrocyte deformability index and the erythrocyte elasticity increased. The values of isolated cell coefficient varied from 0.51 in the treatment with 100 larvae/ml to 0.91 in the incubation with 1000 larvae/ml. This experiment shows that T. spiralis muscle larvae affect significantly the red blood cell aggregation and the erythrocyte viscoelastic properties.


Assuntos
Membrana Eritrocítica/parasitologia , Músculos/parasitologia , Trichinella spiralis/fisiologia , Triquinelose/parasitologia , Animais , Membrana Eritrocítica/química , Feminino , Humanos , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Camundongos , Trichinella spiralis/crescimento & desenvolvimento , Triquinelose/sangue
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