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1.
Eur Rev Med Pharmacol Sci ; 24(16): 8585-8591, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32894566

RESUMO

Some surface proteins of the newly identified severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can bind to the hemoglobin molecule of an erythrocyte, which leads to the destruction of the structure of the heme and the release of harmful iron ions to the bloodstream. The degradation of hemoglobin results in the impairment of oxygen-carrying capacity of the blood, and the accumulation of free iron enhances the production of reactive oxygen species. Both events can lead to the development of oxidative stress. In this case, oxidative damage to the lungs leads then to the injuries of all other tissues and organs. The use of uridine, which preserves the structure of pulmonary alveoli and the air-blood barrier of the lungs in the course of experimental severe hypoxia, and dihydroquercetin, an effective free radical scavenger, is promising for the treatment of COVID-19. These drugs can also be used for the recovery of the body after the severe disease.


Assuntos
Infecções por Coronavirus/patologia , Estresse Oxidativo , Pneumonia Viral/patologia , Betacoronavirus , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Citocinas/metabolismo , Eritrócitos/citologia , Eritrócitos/metabolismo , Eritrócitos/virologia , Depuradores de Radicais Livres/farmacologia , Depuradores de Radicais Livres/uso terapêutico , Hemoglobinas/metabolismo , Humanos , Estresse Oxidativo/efeitos dos fármacos , Pandemias , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Alvéolos Pulmonares/efeitos dos fármacos , Alvéolos Pulmonares/fisiologia , Quercetina/análogos & derivados , Quercetina/farmacologia , Quercetina/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Uridina/farmacologia , Uridina/uso terapêutico
2.
Proc Natl Acad Sci U S A ; 117(29): 17041-17048, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32632001

RESUMO

A central task in developmental biology is to learn the sequence of fate decisions that leads to each mature cell type in a tissue or organism. Recently, clonal labeling of cells using DNA barcodes has emerged as a powerful approach for identifying cells that share a common ancestry of fate decisions. Here we explore the idea that stochasticity of cell fate choice during tissue development could be harnessed to read out lineage relationships after a single step of clonal barcoding. By considering a generalized multitype branching process, we determine the conditions under which the final distribution of barcodes over observed cell types encodes their bona fide lineage relationships. We then propose a method for inferring the order of fate decisions. Our theory predicts a set of symmetries of barcode covariance that serves as a consistency check for the validity of the method. We show that broken symmetries may be used to detect multiple paths of differentiation to the same cell types. We provide computational tools for general use. When applied to barcoding data in hematopoiesis, these tools reconstruct the classical hematopoietic hierarchy and detect couplings between monocytes and dendritic cells and between erythrocytes and basophils that suggest multiple pathways of differentiation for these lineages.


Assuntos
Linhagem da Célula , Código de Barras de DNA Taxonômico/métodos , Animais , Linhagem da Célula/genética , Linhagem da Célula/fisiologia , Árvores de Decisões , Células Dendríticas/citologia , Eritrócitos/citologia , Hematopoese/genética , Hematopoese/fisiologia , Leucócitos/citologia , Modelos Biológicos , Biologia de Sistemas
3.
PLoS One ; 15(7): e0235667, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730271

RESUMO

Botswana's Okavango Delta is a World Heritage Site and biodiverse wilderness. In 2016-2018, following arrival of the annual flood of rainwater from Angola's highlands, and using continuous oxygen logging, we documented profound aquatic hypoxia that persisted for 3.5 to 5 months in the river channel. Within these periods, dissolved oxygen rarely exceeded 3 mg/L and dropped below 0.5 mg/L for up to two weeks at a time. Although these dissolved oxygen levels are low enough to qualify parts of the Delta as a dead zone, the region is a biodiversity hotspot, raising the question of how fish survive. In association with the hypoxia, histological samples, collected from native Oreochromis andersonii (threespot tilapia), Coptodon rendalli (redbreast tilapia), and Oreochromis macrochir (greenhead tilapia), exhibited widespread hepatic and splenic inflammation with marked granulocyte infiltration, melanomacrophage aggregates, and ceroid and hemosiderin accumulations. It is likely that direct tissue hypoxia and polycythemia-related iron deposition caused this pathology. We propose that Okavango cichlids respond to extended natural hypoxia by increasing erythrocyte production, but with significant health costs. Our findings highlight seasonal hypoxia as an important recurring stressor, which may limit fishery resilience in the Okavango as concurrent human impacts rise. Moreover, they illustrate how fish might respond to hypoxia elsewhere in the world, where dead zones are becoming more common.


Assuntos
Oxigênio/química , Tilápia/metabolismo , Animais , Ceroide/metabolismo , Eritrócitos/citologia , Eritrócitos/metabolismo , Feminino , Hemossiderina/metabolismo , Hipóxia , Ferro/metabolismo , Fígado/metabolismo , Fígado/patologia , Masculino , Oxigênio/metabolismo , Rios , Baço/metabolismo , Baço/patologia
4.
Ann Biol Clin (Paris) ; 78(3): 319-322, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32540818

RESUMO

The purpose of this work was to compare the measured red-cell volume (RCV) using sodium pertechnétate [RCV-99mTc] compared to the reference technique using sodium radiochromate [RCV-51Cr] and to assess the influence of technetium-99 elution on the RCV-99mTc value. Ten patients had simultaneous measurements of RCV-99mTc and RCV-51Cr. Elution of Tc-99m from red blood cells was 2.9% and led to an average overestimation of RCV-99mTc of 3.7%. The introduction of individual tracer elution rates in the RCV-99mTc calculation corrects this overestimation.


Assuntos
Radioisótopos de Cromo/farmacologia , Volume de Eritrócitos/efeitos dos fármacos , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Marcação por Isótopo/métodos , Tecnécio/farmacologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Relação Dose-Resposta a Droga , Contagem de Eritrócitos/métodos , Feminino , Hematócrito/métodos , Humanos , Marcação por Isótopo/efeitos adversos , Masculino , Pessoa de Meia-Idade , Técnica de Diluição de Radioisótopos
5.
Ecotoxicol Environ Saf ; 201: 110824, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32544747

RESUMO

The aim of the study was to investigate the effects of sublethal concentrations (0.3, 0.6 and 1.2 mg L-1) of the herbicide Ronstar on the hematology and some immune parameters in Clarias gariepinus juvenile (mean weight and length 58.72 ± 2.46 g and 27.60 ± 1.62 cm, respectively). The hematological and some immune parameters were studied for 21 days in a static renewal bioassay system in which the water and the herbicide were changed daily. The erythrocyte count, hemoglobin concentration (Hb), and packed cell volume (PCV) were significantly (p < 0.05) reduced in the treatment groups. When compared with the control, there were significant (p < 0.05) leucocytosis, lymphocytosis, neutropenia and monocytopenia in the treatment groups. Both the mean corpuscular hemoglobin (MCH) and mean corpuscular volume (MCV) were reduced ((p < 0.05) in the Ronstar-exposed fish. The result showed that the treated fish suffered hypochromic microcytic anemia. The total immunoglobulin and phagocytic indices (phagocytic capacity and phagocytic index) were significantly (p < 0.05) reduced in the treatment groups. while the respiratory burst was significantly (p < 0.05) increased in the treatment groups. The result showed that exposure to Ronstar had adverse effects on the hematology and immunocompetency of the fish.


Assuntos
Peixes-Gato , Herbicidas/toxicidade , Imunoglobulinas/sangue , Oxidiazóis/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Peixes-Gato/sangue , Peixes-Gato/imunologia , Relação Dose-Resposta a Droga , Contagem de Eritrócitos , Índices de Eritrócitos/efeitos dos fármacos , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Hematócrito , Hemoglobinas/análise , Fagócitos/citologia , Fagócitos/efeitos dos fármacos
6.
Transfusion ; 60(5): 922-931, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32358836

RESUMO

BACKGROUND: There have been no prior investigations of the cost effectiveness of transfusion strategies for trauma resuscitation. The Pragmatic, Randomized, Optimal Platelet and Plasma Ratios (PROPPR) study was a Phase III multisite, randomized trial in 680 subjects comparing the efficacy of 1:1:1 transfusion ratios of plasma and platelets to red blood cells with the 1:1:2 ratio. We hypothesized that 1:1:1 transfusion results in an acceptable incremental cost-effectiveness ratio, when estimated using patients' age-specific life expectancy and cost of care during the 30-day PROPPR trial period. STUDY DESIGN AND METHODS: International Classification of Diseases, Ninth Revision codes were prospectively collected, and subjects were matched 1:2 to subjects in the Healthcare Utilization Program State Inpatient Data to estimate cost weights. We used a decision tree analysis, combined with standard costs and estimated years of expected survival to determine the cost effectiveness of the two treatments. RESULTS: The 1:1:1 group had higher overall costs for the blood products but were more likely to achieve hemostasis and decreased hemorrhagic death by 24 hours (p = 0.006). For every 100 patients treated in the 1:1:1 group, eight more achieved hemostasis than in the 1:1:2 group. At 30 days, the total hospital cost per 100 patients was $5.6 million in the 1:1:1 group compared with $5.0 million in the 1:1:2 group. For each 100 patients, the 1:1:1 group had 218.5 more years of life expectancy. This was at a cost of $2994 per year gained. CONCLUSION: The 1:1:1 transfusion ratio in severely injured hemorrhaging trauma patients is a very cost-effective strategy for increasing hemostasis and decreasing trauma deaths.


Assuntos
Transfusão de Sangue/economia , Transfusão de Sangue/métodos , Adolescente , Adulto , Contagem de Células Sanguíneas/economia , Plaquetas/citologia , Transfusão de Sangue/mortalidade , Transfusão de Sangue/estatística & dados numéricos , Análise Custo-Benefício , Contagem de Eritrócitos , Transfusão de Eritrócitos/economia , Transfusão de Eritrócitos/métodos , Transfusão de Eritrócitos/mortalidade , Transfusão de Eritrócitos/estatística & dados numéricos , Eritrócitos/citologia , Feminino , Hemorragia/sangue , Hemorragia/mortalidade , Hemorragia/terapia , Mortalidade Hospitalar , Humanos , Tempo de Internação/economia , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Plasma/citologia , Transfusão de Plaquetas/economia , Transfusão de Plaquetas/métodos , Transfusão de Plaquetas/mortalidade , Transfusão de Plaquetas/estatística & dados numéricos , Ressuscitação/mortalidade , Ressuscitação/estatística & dados numéricos , Adulto Jovem
7.
Nat Methods ; 17(6): 595-599, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32451476

RESUMO

Although label-free cell sorting is desirable for providing pristine cells for further analysis or use, current approaches lack molecular specificity and speed. Here, we combine real-time fluorescence and deformability cytometry with sorting based on standing surface acoustic waves and transfer molecular specificity to image-based sorting using an efficient deep neural network. In addition to general performance, we demonstrate the utility of this method by sorting neutrophils from whole blood without labels.


Assuntos
Citometria de Fluxo/métodos , Microfluídica/métodos , Redes Neurais de Computação , Animais , Técnicas de Cultura de Células , Linhagem Celular , Proliferação de Células , Tamanho Celular , Sobrevivência Celular , Drosophila/citologia , Deformação Eritrocítica , Eritrócitos/citologia , Células HL-60 , Humanos , Células Mieloides/citologia , Neutrófilos/citologia , Som
8.
PLoS Comput Biol ; 16(5): e1007890, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32453720

RESUMO

The biconcave disk shape of the mammalian red blood cell (RBC) is unique to the RBC and is vital for its circulatory function. Due to the absence of a transcellular cytoskeleton, RBC shape is determined by the membrane skeleton, a network of actin filaments cross-linked by spectrin and attached to membrane proteins. While the physical properties of a uniformly distributed actin network interacting with the lipid bilayer membrane have been assumed to control RBC shape, recent experiments reveal that RBC biconcave shape also depends on the contractile activity of nonmuscle myosin IIA (NMIIA) motor proteins. Here, we use the classical Helfrich-Canham model for the RBC membrane to test the role of heterogeneous force distributions along the membrane and mimic the contractile activity of sparsely distributed NMIIA filaments. By incorporating this additional contribution to the Helfrich-Canham energy, we find that the RBC biconcave shape depends on the ratio of forces per unit volume in the dimple and rim regions of the RBC. Experimental measurements of NMIIA densities at the dimple and rim validate our prediction that (a) membrane forces must be non-uniform along the RBC membrane and (b) the force density must be larger in the dimple than the rim to produce the observed membrane curvatures. Furthermore, we predict that RBC membrane tension and the orientation of the applied forces play important roles in regulating this force-shape landscape. Our findings of heterogeneous force distributions on the plasma membrane for RBC shape maintenance may also have implications for shape maintenance in different cell types.


Assuntos
Deformação Eritrocítica , Membrana Eritrocítica/fisiologia , Eritrócitos/citologia , Miosinas/química , Citoesqueleto de Actina/química , Reagentes para Ligações Cruzadas/química , Glicoforinas/química , Humanos , Bicamadas Lipídicas/química , Proteínas de Membrana/química , Microscopia de Fluorescência , Cadeias Pesadas de Miosina/química , Faloidina/química , Rodaminas/química , Estresse Mecânico
9.
Life Sci ; 255: 117838, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32450168

RESUMO

AIMS: Dysregulation of iron homeostasis in the body causes a variety of diseases. Iron deficiency leads to anemia, whereas iron overload aggravates cellular oxidative stress. Nuclear factor erythroid-2-related factor 2 (Nrf2) is a protein that is activated in the nucleus and turns on the production of antioxidant enzymes, protecting cell against oxidative damage. This study aimed to investigate whether Nrf2 gene knockout influences iron homeostasis in aging mice. MATERIALS AND METHODS: Iron content and iron metabolism-related proteins were assessed in different organs and blood serum of the 18 month-old Nrf2 knockout (Nrf2-/-) mice in comparison with the wild-type (WT) mice. KEY FINDINGS: Results showed that the iron contents in spleen and liver all increased, and expression levels of iron transporters were altered in Nrf2-/- mice. In particularly, we found that the expression of iron export protein ferroportin 1 (Fpn1) in liver, spleen and small intestine all decreased in Nrf2-/- mice, which might account for the deposition of iron in different organs and the increased ROS. Surprisingly, we found that the serum iron level of Nrf2-/- mice did not decrease, but increased significantly even when the iron absorption at small intestine decreased. Our further investigation revealed that the increase of serum iron was due to the release of iron from the hemolysis of erythrocytes, which caused by the increased ROS level in red blood cells of the Nrf2-/- mice. SIGNIFICANCE: These findings provide a more comprehensive understanding of the important role of Nrf2 in the regulation of systemic iron metabolism.


Assuntos
Hemólise/fisiologia , Ferro/metabolismo , Fator 2 Relacionado a NF-E2/genética , Espécies Reativas de Oxigênio/metabolismo , Envelhecimento/fisiologia , Animais , Eritrócitos/citologia , Homeostase/fisiologia , Intestino Delgado/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Baço/metabolismo
10.
Transfusion ; 60(5): 1032-1041, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32237236

RESUMO

BACKGROUND: Great deformability allows red blood cells (RBCs) to flow through narrow capillaries in tissues. A number of microfluidic devices with capillary-like microchannels have been developed to monitor storage-related impairment of RBC deformability during blood banking operations. This proof-of-concept study describes a new method to standardize and improve reproducibility of the RBC deformability measurements using one of these devices. STUDY DESIGN AND METHODS: The rate of RBC flow through the microfluidic capillary network of the microvascular analyzer (MVA) device made of polydimethylsiloxane was measured to assess RBC deformability. A suspension of microbeads in a solution of glycerol in phosphate-buffered saline was developed to be used as an internal flow rate reference alongside RBC samples in the same device. RBC deformability and other in vitro quality markers were assessed weekly in six leukoreduced RBC concentrates (RCCs) dispersed in saline-adenine-glucose-mannitol additive solution and stored over 42 days at 4°C. RESULTS: The use of flow reference reduced device-to-device measurement variability from 10% to 2%. Repeated-measure analysis using the generalized estimating equation (GEE) method showed a significant monotonic decrease in relative RBC flow rate with storage from Week 0. By the end of storage, relative RBC flow rate decreased by 22 ± 6% on average. CONCLUSIONS: The suspension of microbeads was successfully used as a flow reference to increase reproducibility of RBC deformability measurements using the MVA. Deformability results suggest an early and late aging phase for stored RCCs, with significant decreases between successive weeks suggesting a highly sensitive measurement method.


Assuntos
Deformação Eritrocítica/fisiologia , Eritrócitos/citologia , Eritrócitos/fisiologia , Dispositivos Lab-On-A-Chip/normas , Técnicas Analíticas Microfluídicas , Bancos de Sangue/métodos , Bancos de Sangue/normas , Velocidade do Fluxo Sanguíneo/fisiologia , Preservação de Sangue/efeitos adversos , Preservação de Sangue/métodos , Preservação de Sangue/normas , Criopreservação , Contagem de Eritrócitos/instrumentação , Contagem de Eritrócitos/métodos , Contagem de Eritrócitos/normas , Citometria de Fluxo/instrumentação , Citometria de Fluxo/métodos , Citometria de Fluxo/normas , Hemólise , Humanos , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Técnicas Analíticas Microfluídicas/normas , Estudo de Prova de Conceito , Reprodutibilidade dos Testes , Fatores de Tempo
11.
Zhonghua Gan Zang Bing Za Zhi ; 28(3): 254-258, 2020 Mar 20.
Artigo em Chinês | MEDLINE | ID: mdl-32306659

RESUMO

Objective: To investigate the feasibility of cationic antimicrobial peptide cathelicidin-PY(PY) therapy through a mouse model of acute liver failure. Methods: The ability of different concentrations of antimicrobial peptide PY to neutralize endotoxin / lipopolysaccharide (LPS) in vitro was detected by Limulus Amebocyte Lysate (LAL) assay. Cell counting kit-8 (CCK-8) was used to detect the toxic effect of different concentrations of antimicrobial peptide PY on mouse monocyte macrophages (RAW264.7). An in vitro hemolysis experiment was used to evaluate the activity of antimicrobial peptide PY on healthy human erythrocytes. D-galactosamine combined with LPS- induced mouse model of acute liver failure was constructed. The antimicrobial peptide PY effect on survival rate of mouse model was observed. HE staining was used to observe the pathological changes of liver tissue. Immunohistochemistry and Western blotting were used to detect the expression of apoptosis-associated protein caspase-3. Intra-group comparisons were performed using t-test and analysis of variance. χ (2) test was used for the comparison of rates. Results: An in vitro experiment showed that the endotoxin neutralization rate was higher at very low dose (0.01 µmol/L), and exceeded 70% at medium-dose (10-40 µmol/L), and the difference between groups with different concentration was statistically significant (F = 569.22, P < 0.05). Medium-dose antimicrobial peptide PY had strong endotoxin neutralizing effect, low cytotoxicity and hemolytic activity. Moreover, in vivo experiments showed that the degree of liver injury and survival rate of mouse model was significantly improved with the medium-dose of antimicrobial peptide PY. Immunohistochemistry results showed that the expression of caspase-3 in the liver tissue was significantly depleted in the medium-dose group than that of the liver failure group, and the results were consistent with protein immunoblotting testing. Conclusion: Antimicrobial peptide PY possesses a strong ability to neutralize endotoxin and few toxic side effects. A specific dose of antimicrobial peptide PY can attenuate hepatocyte apoptosis and significantly improve the survival rate of animal model, and thus provides a new idea for the liver failure treatment.


Assuntos
Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Falência Hepática Aguda/tratamento farmacológico , Neuropeptídeo Y/uso terapêutico , Animais , Apoptose , Células Cultivadas , Eritrócitos/citologia , Hepatócitos/citologia , Humanos , Lipopolissacarídeos , Camundongos , Células RAW 264.7
12.
DNA Cell Biol ; 39(4): 548-554, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32155344

RESUMO

The Qing-Tibet Plateau is characterized by low oxygen pressure, which is an important biomedical and ecological stressor. However, the variation in gene expression during periods of stay on the plateau has not been well studied. We recruited eight volunteers to stay on the plateau for 3, 7, and 30 days. Human Clariom D arrays were used to measure transcriptome changes in the mRNA expression profiles in these volunteers' blood. Analysis of variance (ANOVA) indicated that 699 genes were significantly differentially expressed in response to entering the plateau during hypoxic exposure. The genes with changes in transcript abundance were involved in the terms phosphoprotein, acetylation, protein binding, and protein transport. Furthermore, numerous genes involved in hematopoietic functions, including erythropoiesis and immunoregulation, were differentially expressed in response to hypoxia. This phenomenon may be one of reasons why the majority of people entering the plateau do not have excessive erythrocyte proliferation and are susceptible to infection.


Assuntos
Aclimatação/genética , Doença da Altitude/genética , Doença da Altitude/fisiopatologia , Hipóxia/fisiopatologia , Leucócitos/fisiologia , Altitude , Eritrócitos/citologia , Eritropoese/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/genética , Humanos , Leucopoese/genética , Masculino , Oxigênio , Tibet
13.
J Med Microbiol ; 69(4): 605-616, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32125268

RESUMO

Introduction. Against the backdrop of increasing resistance to conventional antibiotics, bacteriocins represent an attractive alternative, given their potent activity, novel modes of action and perceived lack of issues with resistance.Aim. In this study, the nature of the antibacterial activity of a clinical isolate of Streptococcus gallolyticus was investigated.Methods. Optimization of the production of an inhibitor from strain AB39 was performed using different broth media and supplements. Purification was carried out using size exclusion, ion exchange and HPLC. Gel diffusion agar overlay, MS/MS, de novo peptide sequencing and genome mining were used in a proteogenomics approach to facilitate identification of the genetic basis for production of the inhibitor.Results. Strain AB39 was identified as representing Streptococcus gallolyticus subsp. pasteurianus and the successful production and purification of the AB39 peptide, named nisin P, with a mass of 3133.78 Da, was achieved using BHI broth with 10 % serum. Nisin P showed antibacterial activity towards clinical isolates of drug-resistant bacteria, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus and penicillin-resistant Streptococcus pneumoniae. In addition, the peptide exhibited significant stability towards high temperature, wide pH and certain proteolytic enzymes and displayed very low toxicity towards sheep red blood cells and Vero cells.Conclusion. To the best of our knowledge, this study represents the first production, purification and characterization of nisin P. Further study of nisin P may reveal its potential for treating or preventing infections caused by antibiotic-resistant Gram-positive bacteria, or those evading vaccination regimens.


Assuntos
Nisina/isolamento & purificação , Nisina/farmacologia , Streptococcus gallolyticus/metabolismo , Sequência de Aminoácidos , Animais , Cromatografia , Cromatografia Líquida de Alta Pressão , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Estrutura Molecular , Nisina/química , Nisina/metabolismo , Ovinos , Streptococcus gallolyticus/química , Streptococcus gallolyticus/classificação , Streptococcus gallolyticus/genética , Espectrometria de Massas em Tandem
14.
Biochim Biophys Acta Biomembr ; 1862(6): 183231, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32119860

RESUMO

Aging of red blood cells (RBCs) is associated with alteration in a wide range of RBC features, occurring each on its own timescale. A number of these changes are interrelated and initiate a cascade of biochemical and structural transformations, including band-3 clustering and phosphatidylserine (PS) externalization. Using specific band-3 clustering agents (acridine orange (AO) and ZnCl2), we examined whether treatment of RBCs with these agents may affects PS externalization and whether this process is Ca2+-dependent. RBCs were isolated from the blood of eight healthy donors upon obtaining their informed consent. The suspension was supplemented with increasing concentrations of AO or ZnCl2 (from 0.5 to 2.0 mM) and incubated at 25 °C for 60 min. To detect PS at the RBC surface, we used allophycocyanin-conjugated recombinant human Annexin V. We demonstrated, that treatment of RBCs with both clustering agents caused an elevation in the percent of cells positively labeled by Annexin-V (RBCPS), and that this value was not dependent on the presence of calcium in the buffer: RBCs treated with AO in the presence of either EDTA, EGTA or calcium exhibited similar percentage of RBCPS. Moreover, the active influx of Zn2+ into RBCs induced by their co-incubation with both ZnCl2 and A23187 did not increase the percent of RBCPS as compared to RBCs incubated with ZnCl2 alone. Taken together, these results demonstrate that the band-3 clustering agents (AO or ZnCl2) induce PS externalization in a Ca2+ independent manner, and we hereby suggest a possible scenario for this phenomenon.


Assuntos
Proteína 1 de Troca de Ânion do Eritrócito/metabolismo , Análise por Conglomerados , Eritrócitos/citologia , Fosfatidilserinas/metabolismo , Laranja de Acridina/farmacologia , Anexina A5/metabolismo , Cálcio/farmacologia , Senescência Celular , Cloretos/farmacologia , Humanos , Compostos de Zinco/farmacologia
16.
PLoS Comput Biol ; 16(3): e1007716, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32163405

RESUMO

The influence of red blood cell (RBC) deformability in whole blood on platelet margination is investigated using confocal microscopy measurements of flowing human blood and cell resolved blood flow simulations. Fluorescent platelet concentrations at the wall of a glass chamber are measured using confocal microscopy with flowing human blood containing varying healthy-to-stiff RBC fractions. A decrease is observed in the fluorescent platelet signal at the wall due to the increase of stiffened RBCs in flow, suggesting a decrease of platelet margination due to an increased fraction of stiffened RBCs present in the flow. In order to resolve the influence of stiffened RBCs on platelet concentration at the channel wall, cell-pair and bulk flow simulations are performed. For homogeneous collisions between RBC pairs, a decrease in final displacement after a collision with increasing membrane stiffness is observed. In heterogeneous collisions between healthy and stiff RBC pairs, it is found that the stiffened RBC is displaced most. The influence of RBC deformability on collisions between RBCs and platelets was found to be negligible due to their size and mass difference. For a straight vessel geometry with varying healthy-to-stiff RBC ratios, a decrease was observed in the red blood cell-free layer and platelet margination due to an increase in stiffened RBCs present in flow.


Assuntos
Plaquetas/citologia , Deformação Eritrocítica , Eritrócitos/citologia , Hematócrito , Modelos Biológicos , Técnicas Citológicas , Hemoglobinas/química , Humanos , Microscopia Confocal
17.
PLoS One ; 15(2): e0229105, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32084188

RESUMO

Brain artery velocities (Time-Averaged Maximum Mean Velocity, TAMMV) by Transcranial Doppler (TCD), hematocrit, hemoglobin, Red blood cell (RBC) Distribution Width (RDW) and RBC rigidity index (Ri), when reported together with their correlations, provide a accurate and useful diagnostic picture than blood viscosity measurements alone. Additionally, our study included a sixth parameter provided by TCD, the Gosling Pulsatility Index PI, which is an indicator of CBF (Cerebral Blood Flow) resistance. All these parameters are routine in Hematology except for values of Ri. The rigidity (Ri) of the RBC is the main rheological characteristic of the blood of Sickle Cell Anemia (SCA) patients and several pathologies. However, its quantification depends on many commercial and experimental techniques, none disseminated and predominant around the World. The difference in absorbance values of the blood, during the process of sedimentation in a microwell of a Microplate Reader, is a straightforward way of semi-quantifying the RBC rigidity Ri, since the fraction of irreversibly sickled red blood cells does not form rouleaux. Erythrocyte Rigidity Index (Ri) was calculated using initial absorbance Ainitial (6 s) and final Afinal (540 s), Ri = 1 / (Ai-Af). The Ri of 119 patients (2-17 y / o, M & F) SCA, SCC (Sickle Cell/hemoglobin C), SCD (Sickle Cell/hemoglobin D), Sß0thal (Sickle Cell/hemoglobin Beta Zero Thalassemia) and 71 blood donors (20-65 y / o, M & F) were measured in our laboratory while the five parameters (TAMMV and PI by TCD, Hct, Hb and RDW) were obtained from medical records. The in vitro addition of hydroxyurea (HU, 50mg /dl, n = 51 patients, and n = 8 healthy donors) in the samples decreased the rouleaux adhesion strength of both donor and patients' blood samples, leading to extraordinarily high Ri values. The correlation between the studied parameters was especially significant for the direct relationships between Ri, TAMMV, and PI.


Assuntos
Eritrócitos/citologia , Eritrócitos/metabolismo , Adolescente , Adulto , Idoso , Anemia Falciforme/metabolismo , Velocidade do Fluxo Sanguíneo/fisiologia , Criança , Pré-Escolar , Índices de Eritrócitos , Feminino , Hematócrito , Hemoglobinas/metabolismo , Humanos , Hidroxiureia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
18.
Transfusion ; 60(3): 561-574, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32086956

RESUMO

BACKGROUND: To date, several cases of transfusion-transmitted ZIKV infections have been confirmed. Multiple studies detected prolonged occurrence of ZIKV viral RNA in whole blood as compared to plasma samples indicating potential ZIKV interaction with hematopoietic cells. Also, infection of cells from the granulocyte/macrophage lineage has been demonstrated. Patients may develop severe thrombocytopenia, microcytic anemia, and a fatal course of disease occurred in a patient with sickle cell anemia suggesting additional interference of ZIKV with erythroid and megakaryocytic cells. Therefore, we analyzed whether ZIKV propagates in or compartmentalizes with hematopoietic progenitor, erythroid, and megakaryocytic cells. METHODS: ZIKV RNA replication, protein translation and infectious particle formation in hematopoietic cell lines as well as primary CD34+ HSPCs and ex vivo differentiated erythroid and megakaryocytic cells was monitored using qRT-PCR, FACS, immunofluorescence analysis and infectivity assays. Distribution of ZIKV RNA and infectious particles in spiked red blood cell (RBC) units or platelet concentrates (PCs) was evaluated. RESULTS: While subsets of K562 and KU812Ep6EPO cells supported ZIKV propagation, primary CD34+ HSPCs, MEP cells, RBCs, and platelets were non-permissive for ZIKV infection. In spiking studies, ZIKV RNA was detectable for 7 days in all fractions of RBC units and PCs, however, ZIKV infectious particles were not associated with erythrocytes or platelets. CONCLUSION: Viral particles from plasma or contaminating leukocytes, rather than purified CD34+ HSPCs or the cellular component of RBC units or PCs, present the greatest risk for transfusion-transmitted ZIKV infections.


Assuntos
Antígenos CD34/metabolismo , Plaquetas/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Células Progenitoras de Megacariócitos e Eritrócitos/metabolismo , Infecção por Zika virus/metabolismo , Zika virus/patogenicidade , Diferenciação Celular/fisiologia , Linhagem Celular , Eritrócitos/citologia , Humanos , RNA Viral/genética
20.
Biochemistry (Mosc) ; 85(1): 119-129, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32079523

RESUMO

Suicidal erythrocyte death, or eryptosis, is the key event in eliciting anemia in numerous pathological conditions, including diabetes, chronic kidney disease, cancer, sepsis, etc. Oxidative stress is an important trigger in the acceleration of erythrocyte loss via eryptosis and an underlying mechanism of anemia emergence in the above pathologies. Therefore, there is an increasing demand for identification of antioxidants and anti-eryptotic agents for the management of stress-related ailments. Here, we demonstrated the antioxidant and anti-eryptotic properties of the tamarind seed coat ethanol extract (TSCEE) against 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative stress and eryptosis. The presence of probable secondary metabolites in the TSCEE extract was investigated by RP-HPLC. Active groups present in the TSCEE were studied by the Fourier-transform infrared spectroscopy. Cyclic voltammetric studies confirmed the antioxidant potential of TSCEE. The protective effect of TSCEE on red blood cells was confirmed by assessing various eryptotic markers, such as reactive oxygen species generation, intracellular calcium levels, and phosphatidylserine exposure. TSCEE reduced lipid peroxidation and protein carbonyl content and restored the levels of glutathione, antioxidant enzymes, and enzymes involved in glutathione replenishment. In conclusion, TSCEE was found to exhibit multiple therapeutic properties, which makes it a promising agent for treating oxidative stress-induced eryptosis and subsequent anemia in various pathologies.


Assuntos
Antioxidantes/farmacologia , Eriptose/efeitos dos fármacos , Eritrócitos , Extratos Vegetais/farmacologia , Tamarindus/metabolismo , Biomarcadores/metabolismo , Cálcio/metabolismo , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Glutationa/metabolismo , Humanos , Peroxidação de Lipídeos , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Sementes/metabolismo
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