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1.
BMC Pulm Med ; 20(1): 269, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33066765

RESUMO

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) has spread to almost 100 countries, infected over 31 M patients and resulted in 961 K deaths worldwide as of 21st September 2020. The major clinical feature of severe COVID-19 requiring ventilation is acute respiratory distress syndrome (ARDS) with multi-functional failure as a result of a cytokine storm with increased serum levels of cytokines. The pathogenesis of the respiratory failure in COVID-19 is yet unknown, but diffuse alveolar damage with interstitial thickening leading to compromised gas exchange is a plausible mechanism. Hypoxia is seen in the COVID-19 patients, however, patients present with a distinct phenotype. Intracellular levels of nitric oxide (NO) play an important role in the vasodilation of small vessels. To elucidate the intracellular levels of NO inside of RBCs in COVID-19 patients compared with that of healthy control subjects. METHODS: We recruited 14 COVID-19 infected cases who had pulmonary involvement of their disease, 4 non-COVID-19 healthy controls (without pulmonary involvement and were not hypoxic) and 2 hypoxic non-COVID-19 patients subjects who presented at the Masih Daneshvari Hospital of Tehran, Iran between March-May 2020. Whole blood samples were harvested from patients and intracellular NO levels in 1 × 106 red blood cells (RBC) was measured by DAF staining using flow cytometry (FACS Calibour, BD, CA, USA). RESULTS: The Mean florescent of intensity for NO was significantly enhanced in COVID-19 patients compared with healthy control subjects (P ≤ 0.05). As a further control for whether hypoxia induced this higher intracellular NO, we evaluated the levels of NO inside RBC of hypoxic patients. No significant differences in NO levels were seen between the hypoxic and non-hypoxic control group. CONCLUSIONS: This pilot study demonstrates increased levels of intracellular NO in RBCs from COVID-19 patients. Future multi-centre studies should examine whether this is seen in a larger number of COVID-19 patients and whether NO therapy may be of use in these severe COVID-19 patients.


Assuntos
Dióxido de Carbono/metabolismo , Infecções por Coronavirus/metabolismo , Eritrócitos/metabolismo , Hipóxia/metabolismo , Óxido Nítrico/metabolismo , Oxigênio/metabolismo , Pneumonia Viral/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Assintomáticas , Betacoronavirus , Gasometria , Estudos de Casos e Controles , Infecções por Coronavirus/sangue , Infecções por Coronavirus/complicações , Feminino , Citometria de Fluxo , Humanos , Hipóxia/sangue , Hipóxia/etiologia , Masculino , Pessoa de Meia-Idade , Pandemias , Pressão Parcial , Projetos Piloto , Pneumonia Viral/sangue , Pneumonia Viral/complicações , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/metabolismo , Vasodilatação , Adulto Jovem
2.
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
3.
PLoS Pathog ; 16(8): e1008230, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32797076

RESUMO

Neutrophil extracellular traps (NETs) evolved as a unique effector mechanism contributing to resistance against infection that can also promote tissue damage in inflammatory conditions. Malaria infection can trigger NET release, but the mechanisms and consequences of NET formation in this context remain poorly characterized. Here we show that patients suffering from severe malaria had increased amounts of circulating DNA and increased neutrophil elastase (NE) levels in plasma. We used cultured erythrocytes and isolated human neutrophils to show that Plasmodium-infected red blood cells release macrophage migration inhibitory factor (MIF), which in turn caused NET formation by neutrophils in a mechanism dependent on the C-X-C chemokine receptor type 4 (CXCR4). NET production was dependent on histone citrullination by peptidyl arginine deiminase-4 (PAD4) and independent of reactive oxygen species (ROS), myeloperoxidase (MPO) or NE. In vitro, NETs functioned to restrain parasite dissemination in a mechanism dependent on MPO and NE activities. Finally, C57/B6 mice infected with P. berghei ANKA, a well-established model of cerebral malaria, presented high amounts of circulating DNA, while treatment with DNAse increased parasitemia and accelerated mortality, indicating a role for NETs in resistance against Plasmodium infection.


Assuntos
Eritrócitos/imunologia , Armadilhas Extracelulares/imunologia , Fatores Inibidores da Migração de Macrófagos/metabolismo , Malária/imunologia , Neutrófilos/imunologia , Plasmodium/imunologia , Receptores CXCR4/metabolismo , Animais , Eritrócitos/metabolismo , Eritrócitos/parasitologia , Armadilhas Extracelulares/metabolismo , Armadilhas Extracelulares/parasitologia , Humanos , Malária/metabolismo , Malária/parasitologia , Malária/patologia , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/metabolismo , Neutrófilos/parasitologia , Parasitemia/imunologia , Parasitemia/metabolismo , Parasitemia/parasitologia , Parasitemia/patologia
4.
Nat Commun ; 11(1): 4015, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32782246

RESUMO

Intracellular pathogens mobilize host signaling pathways of their host cell to promote their own survival. Evidence is emerging that signal transduction elements are activated in a-nucleated erythrocytes in response to infection with malaria parasites, but the extent of this phenomenon remains unknown. Here, we fill this knowledge gap through a comprehensive and dynamic assessment of host erythrocyte signaling during infection with Plasmodium falciparum. We used arrays of 878 antibodies directed against human signaling proteins to interrogate the activation status of host erythrocyte phospho-signaling pathways at three blood stages of parasite asexual development. This analysis reveals a dynamic modulation of many host signalling proteins across parasite development. Here we focus on the hepatocyte growth factor receptor (c-MET) and the MAP kinase pathway component B-Raf, providing a proof of concept that human signaling kinases identified as activated by malaria infection represent attractive targets for antimalarial intervention.


Assuntos
Antimaláricos/farmacologia , Eritrócitos/metabolismo , Plasmodium falciparum/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais , Eritrócitos/parasitologia , Interações Hospedeiro-Parasita , Humanos , Concentração Inibidora 50 , Estágios do Ciclo de Vida/efeitos dos fármacos , Malária Falciparum/metabolismo , Malária Falciparum/parasitologia , Fosforilação/efeitos dos fármacos , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium falciparum/metabolismo , Plasmodium falciparum/fisiologia , Análise Serial de Proteínas , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/metabolismo , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-met/metabolismo , Transdução de Sinais/efeitos dos fármacos
5.
Nat Commun ; 11(1): 3825, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32732874

RESUMO

The malaria parasite interfaces with its host erythrocyte (RBC) using a unique organelle, the parasitophorous vacuole (PV). The mechanism(s) are obscure by which its limiting membrane, the parasitophorous vacuolar membrane (PVM), collaborates with the parasite plasma membrane (PPM) to support the transport of proteins, lipids, nutrients, and metabolites between the cytoplasm of the parasite and the cytoplasm of the RBC. Here, we demonstrate that the PV has structure characterized by micrometer-sized regions of especially close apposition between the PVM and the PPM. To determine if these contact sites are involved in any sort of transport, we localize the PVM nutrient-permeable and protein export channel EXP2, as well as the PPM lipid transporter PfNCR1. We find that EXP2 is excluded from, but PfNCR1 is included within these regions of close apposition. We conclude that the host-parasite interface is structured to segregate those transporters of hydrophilic and hydrophobic substrates.


Assuntos
Lipídeos , Malária Falciparum/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/metabolismo , Transporte Biológico , Membrana Celular/metabolismo , Citoplasma/metabolismo , Citoplasma/parasitologia , Eritrócitos/metabolismo , Eritrócitos/parasitologia , Interações Hospedeiro-Parasita , Humanos , Membranas Intracelulares/metabolismo , Membranas Intracelulares/parasitologia , Malária Falciparum/parasitologia , Plasmodium falciparum/fisiologia , Transporte Proteico , Vacúolos/metabolismo , Vacúolos/parasitologia
6.
Int J Mol Sci ; 21(14)2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-32708334

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), also known as coronavirus disease 2019 (COVID-19)-induced infection, is strongly associated with various coagulopathies that may result in either bleeding and thrombocytopenia or hypercoagulation and thrombosis. Thrombotic and bleeding or thrombotic pathologies are significant accompaniments to acute respiratory syndrome and lung complications in COVID-19. Thrombotic events and bleeding often occur in subjects with weak constitutions, multiple risk factors and comorbidities. Of particular interest are the various circulating inflammatory coagulation biomarkers involved directly in clotting, with specific focus on fibrin(ogen), D-dimer, P-selectin and von Willebrand Factor (VWF). Central to the activity of these biomarkers are their receptors and signalling pathways on endothelial cells, platelets and erythrocytes. In this review, we discuss vascular implications of COVID-19 and relate this to circulating biomarker, endothelial, erythrocyte and platelet dysfunction. During the progression of the disease, these markers may either be within healthy levels, upregulated or eventually depleted. Most significant is that patients need to be treated early in the disease progression, when high levels of VWF, P-selectin and fibrinogen are present, with normal or slightly increased levels of D-dimer (however, D-dimer levels will rapidly increase as the disease progresses). Progression to VWF and fibrinogen depletion with high D-dimer levels and even higher P-selectin levels, followed by the cytokine storm, will be indicative of a poor prognosis. We conclude by looking at point-of-care devices and methodologies in COVID-19 management and suggest that a personalized medicine approach should be considered in the treatment of patients.


Assuntos
Plaquetas/metabolismo , Infecções por Coronavirus/patologia , Células Endoteliais/metabolismo , Eritrócitos/metabolismo , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Selectina-P/metabolismo , Pneumonia Viral/patologia , Fator de von Willebrand/metabolismo , Betacoronavirus , Síndrome da Liberação de Citocina/patologia , Humanos , Pandemias , Sistemas Automatizados de Assistência Junto ao Leito , Medicina de Precisão/métodos , Trombocitopenia/patologia , Trombose/patologia
7.
PLoS One ; 15(7): e0235335, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32628695

RESUMO

Diabetes is associated with a dramatic mortality rate due to its vascular complications. Chronic hyperglycemia in diabetes leads to enhanced glycation of erythrocytes and oxidative stress. Even though erythrocytes play a determining role in vascular complications, very little is known about how erythrocyte structure and functionality can be affected by glycation. Our objective was to decipher the impact of glycation on erythrocyte structure, oxidative stress parameters and capacity to interact with cultured human endothelial cells. In vitro glycated erythrocytes were prepared following incubation in the presence of different concentrations of glucose. To get insight into the in vivo relevance of our results, we compared these data to those obtained using red blood cells purified from diabetics or non-diabetics. We measured erythrocyte deformability, susceptibility to hemolysis, reactive oxygen species production and oxidative damage accumulation. Altered structures, redox status and oxidative modifications were increased in glycated erythrocytes. These modifications were associated with reduced antioxidant defence mediated by enzymatic activity. Enhanced erythrocyte phagocytosis by endothelial cells was observed when cultured with glycated erythrocytes, which was associated with increased levels of phosphatidylserine-likely as a result of an eryptosis phenomenon triggered by the hyperglycemic treatment. Most types of oxidative damage identified in in vitro glycated erythrocytes were also observed in red blood cells isolated from diabetics. These results bring new insights into the impact of glycation on erythrocyte structure, oxidative damage and their capacity to interact with endothelial cells, with a possible relevance to diabetes.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Eritrócitos/patologia , Produtos Finais de Glicação Avançada/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Glicemia/metabolismo , Linhagem Celular , Técnicas de Cocultura , Diabetes Mellitus Tipo 2/patologia , Células Endoteliais , Eriptose , Deformação Eritrocítica , Eritrócitos/metabolismo , Hemoglobina A Glicada/análise , Voluntários Saudáveis , Hemólise , Humanos , Estresse Oxidativo , Cultura Primária de Células
8.
Biomed Environ Sci ; 33(6): 414-420, 2020 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-32641204

RESUMO

Objective: To analyze the rate of erythrocyte iron incorporation and provided guidance for the iron nutrition for prepubertal children. Methods: Fifty-seven prepubertal children of Beijing were involved in this study and each subject was orally administered 3 mg of 57Fe twice daily to obtain a total of 30 mg 57Fe after a 5-d period. The stable isotope ratios in RBCs were determined in 14th day, 28th day, 60th day, and 90th day. The erythrocyte incorporation rate in children was calculated using the stable isotope ratios, blood volume and body iron mass. Results: The percentage of erythrocyte 57Fe incorporation increased starting 14 th day, reached a peak at 60 d (boys: 19.67% ± 0.56%, girls: 21.33% ± 0.59%) and then decreased. The erythrocyte incorporation rates of 57Fe obtained for girls in 60th day was significantly higher than those obtained for boys ( P < 0.0001). Conclusions: The oral administration of 57Fe to children can be used to obtain erythrocyte iron incorporation within 90 d. Prepubertal girls should begin to increase the intake of iron and further studies should pay more attention to the iron status in prepubertal children.


Assuntos
Eritrócitos/metabolismo , Isótopos de Ferro/análise , Ferro/metabolismo , Espectrometria de Massas/métodos , Pequim , Criança , Feminino , Humanos , Masculino
9.
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
10.
PLoS Comput Biol ; 16(7): e1008069, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32716940

RESUMO

Nitric oxide (NO) is a gaseous signaling molecule that plays an important role in neurovascular coupling. NO produced by neurons diffuses into the smooth muscle surrounding cerebral arterioles, driving vasodilation. However, the rate of NO degradation in hemoglobin is orders of magnitude higher than in brain tissue, though how this might impact NO signaling dynamics is not completely understood. We used simulations to investigate how the spatial and temporal patterns of NO generation and degradation impacted dilation of a penetrating arteriole in cortex. We found that the spatial location of NO production and the size of the vessel both played an important role in determining its responsiveness to NO. The much higher rate of NO degradation and scavenging of NO in the blood relative to the tissue drove emergent vascular dynamics. Large vasodilation events could be followed by post-stimulus constrictions driven by the increased degradation of NO by the blood, and vasomotion-like 0.1-0.3 Hz oscillations could also be generated. We found that these dynamics could be enhanced by elevation of free hemoglobin in the plasma, which occurs in diseases such as malaria and sickle cell anemia, or following blood transfusions. Finally, we show that changes in blood flow during hypoxia or hyperoxia could be explained by altered NO degradation in the parenchyma. Our simulations suggest that many common vascular dynamics may be emergent phenomena generated by NO degradation by the blood or parenchyma.


Assuntos
Encéfalo/fisiologia , Circulação Cerebrovascular , Óxido Nítrico/metabolismo , Anemia Falciforme/fisiopatologia , Arteríolas , Transfusão de Sangue , Sistema Livre de Células , Simulação por Computador , Difusão , Células Endoteliais/metabolismo , Eritrócitos/metabolismo , Hemodinâmica , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Malária/fisiopatologia , Mitocôndrias/metabolismo , Músculo Liso/metabolismo , Oscilometria , Distribuição de Poisson , Transdução de Sinais , Vasodilatação
11.
J Stroke Cerebrovasc Dis ; 29(8): 104956, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32689646

RESUMO

BACKGROUND AND PURPOSE: Brainstem hemorrhage (BSH) is the most devastating subtype of intracerebral hemorrhage (ICH) with the highest mortality ranging from 56 % to 61.2 %. However, there is no effective medical or surgical therapy to improve its outcomes in clinic to date due to lack of understanding of its injury mechanisms. Herein, we explored the brainstem iron overload and injury in a rat model of BSH. METHODS: Neurological scores were examined on day 1, 3, and 7 after modeling, and mortality of the rats was recorded to draft a survival curve. Rats were monitored by MRI using T2 and susceptibility weighted imaging (SWI) before sacrifice for examination of histology and immunofluorescence on day 1, 3, and 7. RESULTS: BSH rats had a high mortality of 56 % and demonstrated the severe neurological deficits mimicking the clinical conditions. SWI showed that the same increasing tendency in change of hypointense area with that in iron deposition by Perls staining from day 1 to 7. Expression of heme oxygenase 1 (HO-1) and generation of reactive oxygen species (ROS) had similar tendency and both peaked on day 3. Neuronal degeneration occurred and stayed elevated from day 1 to 7, while myelin sheath injury was initially observed on day 1 but without significant difference within 7 days. CONCLUSIONS: The time courses of erythrocyte lysis, HO-1 expression, iron deposition and ROS generation are related to each other after BSH. Besides, brainstem injury including neuronal degeneration and myelin damage were observed and discussed.


Assuntos
Tronco Encefálico/irrigação sanguínea , Tronco Encefálico/metabolismo , Hemorragia Cerebral/metabolismo , Sobrecarga de Ferro/metabolismo , Ferro/metabolismo , Animais , Tronco Encefálico/patologia , Tronco Encefálico/fisiopatologia , Hemorragia Cerebral/patologia , Hemorragia Cerebral/fisiopatologia , Modelos Animais de Doenças , Eritrócitos/metabolismo , Heme Oxigenase (Desciclizante)/metabolismo , Hemólise , Sobrecarga de Ferro/patologia , Sobrecarga de Ferro/fisiopatologia , Masculino , Bainha de Mielina/metabolismo , Bainha de Mielina/patologia , Degeneração Neural , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Fatores de Tempo
12.
PLoS One ; 15(7): e0235752, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32667954

RESUMO

We have limited knowledge of the patterns, causes, and prevalence of elevational migration despite observations of seasonal movements of animals along elevational gradients in montane systems worldwide. While a third of extant Hawaiian landbird species are estimated to be elevational migrants this assumption is based primarily on early naturalist's observations with limited empirical evidence. In this study, we compared stable hydrogen isotopes (δ2H) of metabolically inert (feathers) and active (blood plasma, red blood cells) tissues collected from the same individual to determine if present day populations of Hawaiian honeycreepers undergo elevational movements to track areas of seasonally high flower bloom that constitute significant food resources. We also measured stable carbon isotopes (δ13C) and stable nitrogen isotopes (δ15N) to examine potential changes in diet between time periods. We found that the majority of 'apapane (Himatione sanguinea) and Hawai'i 'amakihi (Chlorodrepanis virens) captured at high elevation, high bloom flowering sites in the fall were not year-round residents at the capture locations, but had molted their feathers at lower elevations presumably in the summer after breeding. δ2H values of feathers for all individuals sampled were higher than blood plasma isotope values after accounting for differences in tissue-specific discrimination. We did not find a difference in the propensity of elevational movement between 'apapane and Hawai'i 'amakihi, even though the 'amakihi is considered more sedentary. However, consistent with a more generalist diet, δ15N values indicated that Hawai'i 'amakihi had a more diverse diet across trophic levels than 'apapane, and a greater reliance on nectar in the fall. We demonstrate that collecting multiple tissue samples, which grow at different rates or time periods, from a single individual can provide insights into elevational movements of Hawaiian honeycreepers over an extended time period.


Assuntos
Migração Animal/fisiologia , Radioisótopos de Carbono/análise , Eritrócitos/metabolismo , Plumas/metabolismo , Marcação por Isótopo/métodos , Radioisótopos de Nitrogênio/análise , Passeriformes/fisiologia , Animais , Hawaii , Dinâmica Populacional
13.
Neurology ; 95(8): e995-e1007, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32669395

RESUMO

OBJECTIVE: To examine whether long-chain omega-3 polyunsaturated fatty acid (LCn3PUFA) levels modify the potential neurotoxic effects of particle matter with diameters <2.5 µm (PM2.5) exposure on normal-appearing brain volumes among dementia-free elderly women. METHODS: A total of 1,315 women (age 65-80 years) free of dementia were enrolled in an observational study between 1996 and 1999 and underwent structural brain MRI in 2005 to 2006. According to prospectively collected and geocoded participant addresses, we used a spatiotemporal model to estimate the 3-year average PM2.5 exposure before the MRI. We examined the joint associations of baseline LCn3PUFAs in red blood cells (RBCs) and PM2.5 exposure with brain volumes in generalized linear models. RESULTS: After adjustment for potential confounders, participants with higher levels of RBC LCn3PUFA had significantly greater volumes of white matter and hippocampus. For each interquartile increment (2.02%) in omega-3 index, the average volume was 5.03 cm3 (p < 0.01) greater in the white matter and 0.08 cm3 (p = 0.03) greater in the hippocampus. The associations with RBC docosahexaenoic acid and eicosapentaenoic acid levels were similar. Higher LCn3PUFA attenuated the inverse associations between PM2.5 exposure and white matter volumes in the total brain and multimodal association areas (frontal, parietal, and temporal; all p for interaction <0.05), while the associations with other brain regions were not modified. Consistent results were found for dietary intakes of LCn3PUFAs and nonfried fish. CONCLUSIONS: Findings from this prospective cohort study among elderly women suggest that the benefits of LCn3PUFAs on brain aging may include the protection against potential adverse effects of air pollution on white matter volumes.


Assuntos
Encéfalo/patologia , Ácidos Graxos Ômega-3/sangue , Envelhecimento Saudável/sangue , Material Particulado/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Exposição Ambiental/efeitos adversos , Eritrócitos/metabolismo , Feminino , Humanos , Imagem por Ressonância Magnética , Estudos Prospectivos
14.
PLoS Pathog ; 16(6): e1008485, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32589689

RESUMO

Ozonide antimalarials, OZ277 (arterolane) and OZ439 (artefenomel), are synthetic peroxide-based antimalarials with potent activity against the deadliest malaria parasite, Plasmodium falciparum. Here we used a "multi-omics" workflow, in combination with activity-based protein profiling (ABPP), to demonstrate that peroxide antimalarials initially target the haemoglobin (Hb) digestion pathway to kill malaria parasites. Time-dependent metabolomic profiling of ozonide-treated P. falciparum infected red blood cells revealed a rapid depletion of short Hb-derived peptides followed by subsequent alterations in lipid and nucleotide metabolism, while untargeted peptidomics showed accumulation of longer Hb-derived peptides. Quantitative proteomics and ABPP assays demonstrated that Hb-digesting proteases were increased in abundance and activity following treatment, respectively. Ozonide-induced depletion of short Hb-derived peptides was less extensive in a drug-treated K13-mutant artemisinin resistant parasite line (Cam3.IIR539T) than in the drug-treated isogenic sensitive strain (Cam3.IIrev), further confirming the association between ozonide activity and Hb catabolism. To demonstrate that compromised Hb catabolism may be a primary mechanism involved in ozonide antimalarial activity, we showed that parasites forced to rely solely on Hb digestion for amino acids became hypersensitive to short ozonide exposures. Quantitative proteomics analysis also revealed parasite proteins involved in translation and the ubiquitin-proteasome system were enriched following drug treatment, suggestive of the parasite engaging a stress response to mitigate ozonide-induced damage. Taken together, these data point to a mechanism of action involving initial impairment of Hb catabolism, and indicate that the parasite regulates protein turnover to manage ozonide-induced damage.


Assuntos
Adamantano/análogos & derivados , Antimaláricos/farmacologia , Eritrócitos , Hemoglobinas/metabolismo , Compostos Heterocíclicos com 1 Anel/farmacologia , Peróxidos/farmacologia , Plasmodium falciparum/metabolismo , Compostos de Espiro/farmacologia , Adamantano/farmacologia , Eritrócitos/metabolismo , Eritrócitos/parasitologia , Hemoglobinas/genética , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Humanos , Plasmodium falciparum/genética , Proteômica
15.
Nat Commun ; 11(1): 2951, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32528158

RESUMO

Biomembranes are two-dimensional assemblies of phospholipids that are only a few nanometres thick, but form micrometre-sized structures vital to cellular function. Explicit molecular modelling of biologically relevant membrane systems is computationally expensive due to the large number of solvent particles and slow membrane kinetics. Coarse-grained solvent-free membrane models offer efficient sampling but sacrifice realistic kinetics, thereby limiting the ability to predict pathways and mechanisms of membrane processes. Here, we present a framework for integrating coarse-grained membrane models with continuum-based hydrodynamics. This framework facilitates efficient simulation of large biomembrane systems with large timesteps, while achieving realistic equilibrium and non-equilibrium kinetics. It helps to bridge between the nanometer/nanosecond spatiotemporal resolutions of coarse-grained models and biologically relevant time- and lengthscales. As a demonstration, we investigate fluctuations of red blood cells, with varying cytoplasmic viscosities, in 150-milliseconds-long trajectories, and compare kinetic properties against single-cell experimental observations.


Assuntos
Membrana Celular/química , Membrana Celular/metabolismo , Simulação por Computador , Eritrócitos/metabolismo , Humanos , Hidrodinâmica , Cinética , Modelos Moleculares , Simulação de Dinâmica Molecular , Fosfolipídeos/química
16.
Int J Nanomedicine ; 15: 3433-3445, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32523342

RESUMO

Background: Reconstituted lipoproteins (rLips) based on endogenous lipid nanostructures has been increasingly regarded as an excellent and promising antitumor drug delivery. However, some problems relating to the main component, apolipoprotein, for instance, rare source, unaffordable price, and low specificity of relevant receptor expression, become chief obstacles to its broad development and application. Purpose: The primary aim of this study is to develop biomimetic rLips by utilizing folic acid (FA)-modified bovine serum albumin (BSA) as a replacement for apolipoprotein and demonstrate its tumor targeting and antitumor efficacy. Methods: The amino groups of BSA were covalently conjugated with FA through the amide reaction. PTX-loaded nanostructured lipid carrier (termed as P-NLC) consisting of phospholipid, cholesteryl ester, triglyceride and cholesterol was prepared by the emulsification-evaporation method and utilized as the lipid core. FA-modified BSA (FA-BSA) was characterized for the protein substitute degree and attached with NLC by incubation-insert method to form the lipoprotein-mimic nanocomplex (termed as PFB-rLips). The morphology of nanoparticles was observed under transmission electron microscopy (TEM), and the particle size and zeta potential were determined using dynamic light scattering. In vitro release behavior of PTX from PFB-rLips was investigated with the dialysis method. Hemolysis tests were conducted to evaluate the biosecurity of PFB-rLips. Cell uptake and cytotoxicity assays were performed on human hepatocytes (LO2) and human hepatoma cells (HepG2). Tumor targeting was assessed using in vivo imaging system in H22 tumor-bearing mice model. Antitumor efficacy in vivo was investigated and compared between Taxol® (paclitaxel) formulation and PTX-incorporated nanoparticles in the same tumor model. Results: A fixed molar ratio 50:1 of FA to BSA was chosen as the optimal input ratio based on the balance between appropriate degree of protein substitution and amphiphilicity of FA-BSA. The morphology of FB-rLips exhibited as a homogeneous spherical structure featured by lipid cores surrounded with a cloudy protein shell observed under TEM. The particle size, zeta potential and encapsulation efficiency were 174.6±3.2 nm, -17.26±0.9 mV and 82.2±2.4%, respectively. In vitro release behavior of PTX from PFB-rLips was slow and sustained. The uptake of FB-rLips was much higher in HepG2 cells than in LO2 cells. Furthermore, the uptake of FB-rLips was significantly higher than that of rLips without FA involved (termed as B-rLips) and NLC in HepG2 cells. Hemolysis and cytotoxicity assays showed good biocompatibility of FB-rLips. The internalization mechanism of FB-rLips mainly depended on clathrin-mediated and caveolin-mediated endocytosis coupling with energy consumption, and FA receptors expressed on tumor cells played a critical role in cellular uptake process. CCK-8 studies demonstrated that PFB-rLips exhibited significantly better tumor killing ability than Taxol® (paclitaxel) formulation in vitro. Moreover, FB-rLips produced more excellent tumor-targeting properties than NLC through in vivo imaging assays. On the basis of this, PTX-loaded FB-rLips also performed more remarkable anticancer activity than other therapy groups in H22 tumor-bearing mice. Conclusion: FB-rLips would serve as a potential nanocarrier for improving tumor-targeting and therapeutic efficacy while reducing the side effects on normal tissues and organs.


Assuntos
Portadores de Fármacos/química , Ácido Fólico/uso terapêutico , Lipoproteínas/química , Nanopartículas/química , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Liberação Controlada de Fármacos , Endocitose/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Ácido Fólico/síntese química , Ácido Fólico/química , Hemólise/efeitos dos fármacos , Humanos , Camundongos , Nanopartículas/ultraestrutura , Neoplasias/patologia , Paclitaxel/química , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Tamanho da Partícula , Coelhos , Soroalbumina Bovina/química , Eletricidade Estática
17.
Proc Natl Acad Sci U S A ; 117(26): 15018-15027, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32527859

RESUMO

The pathology of sickle cell disease is caused by polymerization of the abnormal hemoglobin S upon deoxygenation in the tissues to form fibers in red cells, causing them to deform and occlude the circulation. Drugs that allosterically shift the quaternary equilibrium from the polymerizing T quaternary structure to the nonpolymerizing R quaternary structure are now being developed. Here we update our understanding on the allosteric control of fiber formation at equilibrium by showing how the simplest extension of the classic quaternary two-state allosteric model of Monod, Wyman, and Changeux to include tertiary conformational changes provides a better quantitative description. We also show that if fiber formation is at equilibrium in vivo, the vast majority of cells in most tissues would contain fibers, indicating that it is unlikely that the disease would be survivable once the nonpolymerizing fetal hemoglobin has been replaced by adult hemoglobin S at about 1 y after birth. Calculations of sickling times, based on a recently discovered universal relation between the delay time prior to fiber formation and supersaturation, show that in vivo fiber formation is very far from equilibrium. Our analysis indicates that patients survive because the delay period allows the majority of cells to escape the small vessels of the tissues before fibers form. The enormous sensitivity of the duration of the delay period to intracellular hemoglobin composition also explains why sickle trait, the heterozygous condition, and the compound heterozygous condition of hemoglobin S with pancellular hereditary persistence of fetal hemoglobin are both relatively benign conditions.


Assuntos
Anemia Falciforme/metabolismo , Hemoglobina Falciforme/química , Oxigênio/metabolismo , Regulação Alostérica , Eritrócitos/química , Eritrócitos/metabolismo , Hemoglobina Fetal/química , Hemoglobina Fetal/metabolismo , Hemoglobina Falciforme/metabolismo , Humanos , Cinética , Oxigênio/química
18.
Nature ; 583(7814): 96-102, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32581362

RESUMO

Most patients with rare diseases do not receive a molecular diagnosis and the aetiological variants and causative genes for more than half such disorders remain to be discovered1. Here we used whole-genome sequencing (WGS) in a national health system to streamline diagnosis and to discover unknown aetiological variants in the coding and non-coding regions of the genome. We generated WGS data for 13,037 participants, of whom 9,802 had a rare disease, and provided a genetic diagnosis to 1,138 of the 7,065 extensively phenotyped participants. We identified 95 Mendelian associations between genes and rare diseases, of which 11 have been discovered since 2015 and at least 79 are confirmed to be aetiological. By generating WGS data of UK Biobank participants2, we found that rare alleles can explain the presence of some individuals in the tails of a quantitative trait for red blood cells. Finally, we identified four novel non-coding variants that cause disease through the disruption of transcription of ARPC1B, GATA1, LRBA and MPL. Our study demonstrates a synergy by using WGS for diagnosis and aetiological discovery in routine healthcare.


Assuntos
Internacionalidade , Programas Nacionais de Saúde , Doenças Raras/diagnóstico , Doenças Raras/genética , Sequenciamento Completo do Genoma , Complexo 2-3 de Proteínas Relacionadas à Actina/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Alelos , Bases de Dados Factuais , Eritrócitos/metabolismo , Fator de Transcrição GATA1/genética , Humanos , Fenótipo , Locos de Características Quantitativas , Receptores de Trombopoetina/genética , Medicina Estatal , Reino Unido
19.
J Vis Exp ; (159)2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32510517

RESUMO

CR1 (CD35, Complement Receptor type 1 for C3b/C4b) is a high molecular weight membrane glycoprotein of about 200 kDa that controls complement activation, transports immune complexes, and participates in humoral and cellular immune responses. CR1 is present on the surface of many cell types, including erythrocytes, and exhibits polymorphisms in length, structure (Knops, or KN, blood group), and density. The average density of CR1 per erythrocyte (CR1/E) is 500 molecules per erythrocyte. This density varies from one individual to another (100-1,200 CR1/E) and from one erythrocyte to another in the same individual. We present here a robust flow cytometry method to measure the density of CR1/E, including in subjects expressing a low density, with the help of an amplifying immunostaining system. This method has enabled us to show the lowering of CR1 erythrocyte expression in diseases such as Alzheimer's disease (AD), systemic lupus erythematosus (SLE), AIDS, or malaria.


Assuntos
Eritrócitos/metabolismo , Citometria de Fluxo/métodos , Receptores de Complemento/sangue , Calibragem , Contagem de Células , Humanos , Análise de Regressão
20.
Am J Physiol Cell Physiol ; 319(2): C250-C257, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32579474

RESUMO

The classic view of the red blood cell (RBC) presents a biologically inert cell that upon maturation has limited capacity to alter its physical properties. This view developed largely because of the absence of translational machinery and inability to synthesize or repair proteins in circulating RBC. Recent developments have challenged this perspective, in light of observations supporting the importance of posttranslational modifications and greater understanding of ion movement in these cells, that each regulate a myriad of cellular properties. There is thus now sufficient evidence to induce a step change in understanding of RBC: rather than passively responding to the surrounding environment, these cells have the capacity to actively regulate their physical properties and thus alter flow behavior of blood. Specific evidence supports that the physical and rheological properties of RBC are subject to active modulation, primarily by the second-messenger molecules nitric oxide (NO) and calcium-ions (Ca2+). Furthermore, an isoform of nitric oxide synthase is expressed in RBC (RBC-NOS), which has been recently demonstrated to have an active role in regulating the physical properties of RBC. Mechanical stimulation of the cell membrane activates RBC-NOS, leading to NO generation, which has several intracellular effects, including the S-nitrosylation of integral membrane components. Intracellular concentration of Ca2+ is increased upon mechanical stimulation via the recently identified mechanosensitive cation channel piezo1. Increased intracellular Ca2+ modifies the physical properties of RBC by regulating cell volume and potentially altering several important intracellular proteins. A synthesis of recent advances in understanding of molecular processes within RBC thus challenges the classic view of these cells and rather indicates a highly active cell with self-regulated mechanical properties.


Assuntos
Eritrócitos/metabolismo , Canais Iônicos/genética , Mecanotransdução Celular/genética , Óxido Nítrico Sintase/genética , Cálcio/metabolismo , Membrana Celular/enzimologia , Membrana Celular/genética , Ativação Enzimática/genética , Eritrócitos/enzimologia , Regulação Enzimológica da Expressão Gênica/genética , Humanos , Canais Iônicos/sangue , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/metabolismo
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