RESUMO
ISG20L2, a 3' to 5' exoribonuclease previously associated with ribosome biogenesis, is identified here in activated T cells as an enzyme with a preferential affinity for uridylated miRNA substrates. This enzyme is upregulated in T lymphocytes upon TCR and IFN type I stimulation and appears to be involved in regulating T cell function. ISG20L2 silencing leads to an increased basal expression of CD69 and induces greater IL2 secretion. However, ISG20L2 absence impairs CD25 upregulation, CD3 synaptic accumulation and MTOC translocation towards the antigen-presenting cell during immune synapsis. Remarkably, ISG20L2 controls the expression of immunoregulatory molecules, such as AHR, NKG2D, CTLA-4, CD137, TIM-3, PD-L1 or PD-1, which show increased levels in ISG20L2 knockout T cells. The dysregulation observed in these key molecules for T cell responses support a role for this exonuclease as a novel RNA-based regulator of T cell function.
Assuntos
Ativação Linfocitária , MicroRNAs , Células Apresentadoras de Antígenos , Endonucleases , MicroRNAs/genética , HumanosRESUMO
The HD-ZIP III transcription factor REVOLUTA (REV) is involved in early leaf development, as well as in leaf senescence. REV directly binds to the promoters of senescence-associated genes, including the central regulator WRKY53. As this direct regulation appears to be restricted to senescence, we aimed to characterize protein-interaction partners of REV which could mediate this senescence-specificity. The interaction between REV and the TIFY family member TIFY8 was confirmed by yeast two-hybrid assays, as well as by bimolecular fluorescence complementation in planta. This interaction inhibited REV's function as an activator of WRKY53 expression. Mutation or overexpression of TIFY8 accelerated or delayed senescence, respectively, but did not significantly alter early leaf development. Jasmonic acid (JA) had only a limited effect on TIFY8 expression or function; however, REV appears to be under the control of JA signaling. Accordingly, REV also interacted with many other members of the TIFY family, namely the PEAPODs and several JAZ proteins in the yeast system, which could potentially mediate the JA-response. Therefore, REV appears to be under the control of the TIFY family in two different ways: a JA-independent way through TIFY8, which controls REV function in senescence, and a JA-dependent way through PEAPODs and JAZ proteins.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Ciclopentanos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica de Plantas , Oxilipinas/metabolismo , Folhas de Planta/metabolismo , Senescência Vegetal , Fatores de Transcrição/metabolismoRESUMO
Horizontal gene transfer was long thought to be marginal in Mollicutes, but the capacity of some of these wall-less bacteria to exchange large chromosomal regions has been recently documented. Mycoplasma chromosomal transfer (MCT) is an unconventional mechanism that relies on the presence of a functional integrative conjugative element (ICE) in at least one partner and involves the horizontal acquisition of small and large chromosomal fragments from any part of the donor genome, which results in progenies composed of an infinite variety of mosaic genomes. The present study focuses on Mycoplasma bovis, an important pathogen of cattle responsible for major economic losses worldwide. By combining phylogenetic tree reconstructions and detailed comparative genome analyses of 36 isolates collected in Spain (2016 to 2018), we confirmed the mosaic nature of 16 field isolates and mapped chromosomal transfers exchanged between their hypothetical ancestors. This study provides evidence that MCT can take place in the field, most likely during coinfections by multiple strains. Because mobile genetic elements (MGEs) are classical contributors of genome plasticity, the presence of phages, insertion sequences (ISs), and ICEs was also investigated. Data revealed that these elements are widespread within the M. bovis species and evidenced classical horizontal transfer of phages and ICEs in addition to MCT. These events contribute to wide-genome diversity and reorganization within this species and may have a tremendous impact on diagnostic and disease control. IMPORTANCE Mycoplasma bovis is a major pathogen of cattle that has significant detrimental effects on economics and animal welfare in cattle rearing worldwide. Understanding the evolution and the adaptative potential of pathogenic mycoplasma species in the natural host is essential to combating them. In this study, we documented the occurrence of mycoplasma chromosomal transfer, an atypical mechanism of horizontal gene transfer, in field isolates of M. bovis that provide new insights into the evolution of this pathogenic species in their natural host. Although these events are expected to occur at low frequency, their impact is accountable for genome-wide variety and reorganization within M. bovis species, which may compromise both diagnostic and disease control.
Assuntos
Mycoplasma bovis , Tenericutes , Animais , Bovinos , Transferência Genética Horizontal , Mosaicismo , Mycoplasma bovis/genética , FilogeniaRESUMO
Intercellular communication orchestrates effective immune responses against disease-causing agents. Extracellular vesicles (EVs) are potent mediators of cell-cell communication. EVs carry bioactive molecules, including microRNAs, which modulate gene expression and function in the recipient cell. Here, we show that formation of cognate primary T-B lymphocyte immune contacts promotes transfer of a very restricted set of T-cell EV-microRNAs (mmu-miR20-a-5p, mmu-miR-25-3p, and mmu-miR-155-3p) to the B cell. Transferred EV-microRNAs target key genes that control B-cell function, including pro-apoptotic BIM and the cell cycle regulator PTEN. EV-microRNAs transferred during T-B cognate interactions also promote survival, proliferation, and antibody class switching. Using mouse chimeras with Rab27KO EV-deficient T cells, we demonstrate that the transfer of small EVs is required for germinal center reaction and antibody production in vivo, revealing a mechanism that controls B-cell responses via the transfer of EV-microRNAs of T-cell origin. These findings also provide mechanistic insight into the Griscelli syndrome, associated with a mutation in the Rab27a gene, and might explain antibody defects observed in this pathogenesis and other immune-related and inflammatory disorders.
Assuntos
Vesículas Extracelulares , MicroRNAs , Animais , Formação de Anticorpos , Comunicação Celular , Centro Germinativo , Camundongos , MicroRNAs/genéticaRESUMO
Leaf senescence is an integral part of plant development and is driven by endogenous cues such as leaf or plant age. Developmental senescence aims to maximize the usage of carbon, nitrogen and mineral resources for growth and/or for the sake of the next generation. This requires efficient reallocation of the resources out of the senescing tissue into developing parts of the plant such as new leaves, fruits and seeds. However, premature senescence can be induced by severe and long-lasting biotic or abiotic stress conditions. It serves as an exit strategy to guarantee offspring in an unfavorable environment but is often combined with a trade-off in seed number and quality. In order to coordinate the very complex process of developmental senescence with environmental signals, highly organized networks and regulatory cues have to be in place. Reactive oxygen species, especially hydrogen peroxide (H2O2), are involved in senescence as well as in stress signaling. Here, we want to summarize the role of H2O2 as a signaling molecule in leaf senescence and shed more light on how specificity in signaling might be achieved. Altered hydrogen peroxide contents in specific compartments revealed a differential impact of H2O2 produced in different compartments. Arabidopsis lines with lower H2O2 levels in chloroplasts and cytoplasm point to the possibility that not the actual contents but the ratio between the two different compartments is sensed by the plant cells.
Assuntos
Arabidopsis , Arabidopsis/metabolismo , Senescência Celular , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio , Folhas de Planta , Senescência VegetalRESUMO
MicroRNAs (miRNAs) act as master regulators of gene expression in homeostasis and disease. Despite the rapidly growing body of evidence on the theranostic potential of restoring miRNA levels in pre-clinical models, the translation into clinics remains limited. Here, we review the current knowledge of miRNAs as T-cell targeting immunotherapeutic tools, and we offer an overview of the recent advances in miRNA delivery strategies, clinical trials and future perspectives in RNA interference technologies.
Assuntos
MicroRNAs , MicroRNAs/genética , MicroRNAs/uso terapêutico , Linfócitos T , Interferência de RNA , Medicina de Precisão , ImunoterapiaRESUMO
A central function of health technology assessment (HTA) agencies is the production of HTA reports to support evidence-informed policy and decision making. HTA agencies are interested in understanding the mechanisms of HTA impact, which can be understood as the influence or impact of HTA report findings on decision making at various levels of the health system. The members of the International Network of Agencies for HTA (INAHTA) meet at their annual Congress where impact story sharing is one important activity. This paper summarizes four stories of HTA impact that were finalists for the David Hailey Award for Best Impact Story.The methods to measure impact include: document review; claims analysis and review of reimbursement status; citation analysis; qualitative evaluation of stakeholders' views; and review of media response. HTA agency staff also observed changes in government activities and priorities based on the HTA. Impact assessment can provide information to improve the HTA process, for example, the value of patient and clinician engagement in the HTA process to better define the assessment question and literature reviews in a more holistic and balanced way.HTA reports produced by publicly funded HTA agencies are valued by health systems around the globe as they support decision making regarding the appropriate use, pricing, reimbursement, and disinvestment of health technologies. HTAs can also have a positive impact on information sharing between different levels of government and across stakeholder groups. These stories show how HTA can have a significant impact, irrespective of the health system and health technology being assessed.
Assuntos
Tomada de Decisões , Avaliação da Tecnologia Biomédica/organização & administração , Distinções e Prêmios , Congressos como Assunto/organização & administração , Desfibriladores Implantáveis , Genômica/organização & administração , Humanos , Participação do Paciente/métodos , Farmacopeias como Assunto/normas , Políticas , Avaliação da Tecnologia Biomédica/normas , Vertebroplastia/economia , Vertebroplastia/métodosRESUMO
Activation of T lymphocytes requires a tight regulation of microRNA (miRNA) expression. Terminal uridyltransferases (TUTases) catalyze 3' nontemplated nucleotide addition (3'NTA) to miRNAs, which may influence miRNA stability and function. Here, we investigated 3'NTA to mature miRNA in CD4 T lymphocytes by deep sequencing. Upon T-cell activation, miRNA sequences bearing terminal uridines are specifically decreased, concomitantly with down-regulation of TUT4 and TUT7 enzymes. Analyzing TUT4-deficient T lymphocytes, we proved that this terminal uridyltransferase is essential for the maintenance of miRNA uridylation in the steady state of T lymphocytes. Analysis of synthetic uridylated miRNAs shows that 3' addition of uridine promotes degradation of these uridylated miRNAs after T-cell activation. Our data underline post-transcriptional uridylation as a mechanism to fine-tune miRNA levels during T-cell activation.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Ativação Linfocitária/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Uridina/metabolismo , Animais , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Humanos , Ativação Linfocitária/imunologia , Camundongos , Camundongos Knockout , MicroRNAs/química , Modelos Biológicos , Estabilidade de RNA , Uridina/químicaRESUMO
Human NK cells are activated by cytokines, immune complexes, and signals transduced via activating ligands on other host cells. After vaccination, or during secondary infection, adaptive immune responses can enhance both cytokine-driven and Ab-dependent NK cell responses. However, induction of NK cells for enhanced function after in vitro exposure to innate inflammatory cytokines has also been reported and may synergize with adaptive signals to potentiate NK cell activity during infection or vaccination. To test this hypothesis, we examined the effect of seasonal influenza vaccination on NK cell function and phenotype in 52 previously unvaccinated individuals. Enhanced, IL-2-dependent, NK cell IFN-γ responses to Influenza A/California/7/2009 virus were detected up to 4 wk postvaccination and higher in human CMV (HCMV)-seronegative (HCMV(-)) individuals than in HCMV-seropositive (HCMV(+)) individuals. By comparison, robust NK cell degranulation responses were observed both before and after vaccination, due to high titers of naturally occurring anti-influenza Abs in human plasma, and did not differ between HCMV(+) and HCMV(-) subjects. In addition to these IL-2-dependent and Ab-dependent responses, NK cell responses to innate cytokines were also enhanced after influenza vaccination; this was associated with proliferation of CD57(-) NK cells and was most evident in HCMV(+) subjects. Similar enhancement of cytokine responsiveness was observed when NK cells were cocultured in vitro with Influenza A/California/7/2009 virus, and this was at least partially dependent upon IFN-αßR2. In summary, our data indicate that attenuated or live viral vaccines promote cytokine-induced memory-like NK cells and that this process is influenced by HCMV infection.
Assuntos
Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Memória Imunológica , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Células Matadoras Naturais/imunologia , Orthomyxoviridae/imunologia , Adulto , Células Cultivadas , Infecções por Citomegalovirus/complicações , Humanos , Influenza Humana/complicações , Interferon gama/metabolismo , Interleucina-2/metabolismo , Ativação Linfocitária , Pessoa de Meia-Idade , Vacinação , Adulto JovemRESUMO
NK cells contribute to postvaccination immune responses after activation by IL-2 from Ag-specific memory T cells or by cross-linking of the low-affinity IgG receptor, CD16, by Ag-Ab immune complexes. Sensitivity of NK cells to these signals from the adaptive immune system is heterogeneous and influenced by their stage of differentiation. CD56(dim)CD57(+) NK cells are less responsive to IL-2 and produce less IFN-γ in response to T cell-mediated activation than do CD56(bright) or CD56(dim)CD57(-) NK cells. Conversely, NK cell cytotoxicity, as measured by degranulation, is maintained across the CD56(dim) subsets. Human CMV (HCMV), a highly prevalent herpes virus causing lifelong, usually latent, infections, drives the expansion of the CD56(dim)CD57(+)NKG2C(+) NK cell population, skewing the NK cell repertoire in favor of cytotoxic responses at the expense of cytokine-driven responses. We hypothesized, therefore, that HCMV seropositivity would be associated with altered NK cell responses to vaccine Ags. In a cross-sectional study of 152 U.K. adults, with HCMV seroprevalence rate of 36%, we find that HCMV seropositivity is associated with lower NK cell IFN-γ production and degranulation after in vitro restimulation with pertussis or H1N1 influenza vaccine Ags. Higher expression of CD57/NKG2C and lower expression of IL-18Rα on NK cells from HCMV seropositive subjects do not fully explain these impaired responses, which are likely the result of multiple receptor-ligand interactions. This study demonstrates for the first time, to our knowledge, that HCMV serostatus influences NK cell contributions to adaptive immunity and raises important questions regarding the impact of HCMV infection on vaccine efficacy.
Assuntos
Infecções por Citomegalovirus/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/imunologia , Células Matadoras Naturais/imunologia , Vacina contra Coqueluche/imunologia , Adulto , Idoso , Estudos Transversais , Citomegalovirus/imunologia , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , Adulto JovemRESUMO
OBJECTIVES: The impact of health technology assessment (HTA) in the judicialization of the right of health has not been deeply studied in Latin American countries. The purpose of this study is to review the process of judicialization of the access to high cost drugs in Uruguay and assess the impact HTAs have had on this process. METHODS: The methodology used for this study included a comprehensive literature search in electronic databases, local journals, internal documents developed in the Ministry of Health, as well as conducting interviews with key informants. RESULTS: Judicialization of the access of high cost drugs has been increasing since 2010. The strategy of the Ministry of Health of Uruguay to decrease this problem included the organization of roundtables with judges and other stakeholders on the basis of HTA, the training of defense lawyers in the use and interpretation of HTA, and the participation of a professional who develops HTA in the preparation of the defense arguments. A year after the implementation of this strategy, 25 percent of writs of protection were won by the Ministry of Health. CONCLUSIONS: Even though the strategy implemented was effective in reducing the loss of litigations, it was not effective in reducing the growing number of writs of protection. It is essential to address this problem in a broad debate and to promote understanding between the parties.
Assuntos
Custos de Medicamentos , Acessibilidade aos Serviços de Saúde/organização & administração , Programas Nacionais de Saúde/organização & administração , Avaliação da Tecnologia Biomédica/organização & administração , Controle de Custos , Análise Custo-Benefício , Acessibilidade aos Serviços de Saúde/legislação & jurisprudência , Humanos , Programas Nacionais de Saúde/legislação & jurisprudência , UruguaiRESUMO
Ischemic stroke is an acute vascular event that compromises neuronal viability, and identification of the pathophysiological mechanisms is critical for its correct management. Ischemia produces increased nitric oxide synthesis to recover blood flow but also induces a free radical burst. Nitric oxide and superoxide anion react to generate peroxynitrite that nitrates tyrosines. We found that fibrinogen nitrotyrosination was detected in plasma after the initiation of ischemic stroke in human patients. Electron microscopy and protein intrinsic fluorescence showed that in vitro nitrotyrosination of fibrinogen affected its structure. Thromboelastography showed that initially fibrinogen nitrotyrosination retarded clot formation but later made the clot more resistant to fibrinolysis. This result was independent of any effect on thrombin production. Immunofluorescence analysis of affected human brain areas also showed that both fibrinogen and nitrotyrosinated fibrinogen spread into the brain parenchyma after ischemic stroke. Therefore, we assayed the toxicity of fibrinogen and nitrotyrosinated fibrinogen in a human neuroblastoma cell line. For that purpose we measured the activity of caspase-3, a key enzyme in the apoptotic pathway, and cell survival. We found that nitrotyrosinated fibrinogen induced higher activation of caspase 3. Accordingly, cell survival assays showed a more neurotoxic effect of nitrotyrosinated fibrinogen at all concentrations tested. In summary, nitrotyrosinated fibrinogen would be of pathophysiological interest in ischemic stroke due to both its impact on hemostasis - it impairs thrombolysis, the main target in stroke treatments - and its neurotoxicity that would contribute to the death of the brain tissue surrounding the infarcted area.
Assuntos
Apoptose , Isquemia Encefálica/metabolismo , Encéfalo/metabolismo , Fibrinogênio/metabolismo , Fibrinólise , Neurônios/metabolismo , Acidente Vascular Cerebral/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Encéfalo/patologia , Isquemia Encefálica/patologia , Caspase 3/metabolismo , Linhagem Celular Tumoral , Ativação Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neurônios/patologia , Ratos , Ratos Sprague-Dawley , Acidente Vascular Cerebral/patologia , Tirosina/análogos & derivados , Tirosina/metabolismoRESUMO
Platelets are important in hemostasis, but also detect particles and pathogens in the circulation. Phagocytic and endocytic activities of platelets are widely recognized; however, receptors and mechanisms involved remain poorly understood. We previously demonstrated that platelets internalize and store phospholipid microvesicles enriched in human tissue factor (TF+MVs) and that platelet-associated TF enhances thrombus formation at sites of vascular damage. Here, we investigate the mechanisms implied in the interactions of TF+MVs with platelets and the effects of specific inhibitory strategies. Aggregometry and electron microscopy were used to assess platelet activation and TF+MVs uptake. Cytoskeletal assembly and activation of phosphoinositide 3-kinase (PI3K) and RhoA were analyzed by western blot and ELISA. Exposure of platelets to TF+MVs caused reversible platelet aggregation, actin polymerization and association of contractile proteins to the cytoskeleton being maximal at 1 min. The same kinetics were observed for activation of PI3K and translocation of RhoA to the cytoskeleton. Inhibitory strategies to block glycoprotein IIb-IIIa (GPIIb-IIIa), scavenger receptor CD36, serotonin transporter (SERT) and PI3K, fully prevented platelet aggregation by TF+MVs. Ultrastructural techniques revealed that uptake of TF+MVs was efficiently prevented by anti-CD36 and SERT inhibitor, but only moderately interfered by GPIIb-IIIa blockade. We conclude that internalization of TF+MVs by platelets occurs independently of receptors related to their main hemostatic function (GPIIb-IIIa), involves the scavenger receptor CD36, SERT and engages PI3-Kinase activation and cytoskeletal assembly. CD36 and SERT appear as potential therapeutic targets to interfere with the association of TF+MVs with platelets and possibly downregulate their prothrombotic phenotype.
Assuntos
Plaquetas/fisiologia , Antígenos CD36/metabolismo , Micropartículas Derivadas de Células/metabolismo , Citoesqueleto/metabolismo , Fragmentos de Peptídeos/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Tromboplastina/metabolismo , Células Cultivadas , Ativação Enzimática , Humanos , Integrina beta3/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Agregação Plaquetária , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Transporte Proteico , Transdução de Sinais , Proteína rhoA de Ligação ao GTP/metabolismoRESUMO
BACKGROUND: Cryopreserved platelet (CPP) concentrates exhibit a variety of morphologic and functional alterations that may affect the action of CPP with accelerated platelet (PLT) response and clotting. The objective of this study was to compare the in vitro hemostatic effect of CPP with fresh whole blood (WB) and standard 5-day PLT concentrates (PCs). STUDY DESIGN AND METHODS: WB collected from eight healthy donors was used to prepare fresh WB, PLT-depleted WB (TPN), and PLT-restored TPN using CPP (TPN-CPP) or PC (TPN-PC). Clot properties were evaluated with thromboelastometry (ROTEM); adhesion and aggregate formation under high shear (Impact-R); and PLT adhesion, aggregate formation, fibrin formation, and prothrombin activation under medium shear in a perfusion system. RESULTS: TPN-CPP had faster clot initiation (ROTEM clot time--TPN-CPP 115 sec, WB 194 sec, TPN-PC 161 sec), and CPP contributes to a strong clot with PLT involvement (maximum clot firmness--TPN-CPP 32 mm, WB 62 mm, TPN-PC 59 mm). The Impact-R PLT-covered area with TPN-CPP was less than those of WB and PCs, but aggregate size was the same as WB. PLT coverage in perfusion studies was observed with TPN-CPP, although generally less than both WB and PC. Fibrin was deposited with CPP-restored samples, but did not exceed the level of WB. CONCLUSION: CPPs present a phenotype supporting a moderate increase in the rate of clot formation, form stable PLT clots, and do not present a hypercoagulable phenotype during in vitro functional tests.
Assuntos
Plaquetas/citologia , Preservação de Sangue/efeitos adversos , Criopreservação , Coagulação Sanguínea/fisiologia , Testes de Coagulação Sanguínea , Hemostasia/fisiologia , Hemostáticos , Humanos , Leucócitos/citologia , Adesividade Plaquetária/fisiologia , Agregação Plaquetária/fisiologiaRESUMO
OBJECTIVES: The aim of this study was to obtain information on methods used to measure health technology assessment (HTA) influence, decisions that were influenced, and outcomes linked to HTA. METHODS: Electronic databases were used to locate studies in which HTA influence had been demonstrated. Inclusion criteria were studies that reliably reported consideration by decision makers of HTA findings; comparative studies of technology use before and after HTA; and details of changes in policy, health outcomes, or research that could be credibly linked to an HTA. RESULTS: Fifty-one studies were selected for review. Settings were national (24), regional (12), both national and regional (3) hospitals (9), and multinational (3). The most common approach to appraisal of influence was review of policy or administrative decisions following HTA recommendations (51 percent). Eighteen studies (35 percent) reported interview or survey findings, thirteen (26 percent) reviewed administrative data, and six considered the influence of primary studies. Of 142 decisions informed by HTA, the most common types were on routine clinical practice (67 percent of studies), coverage (63 percent), and program operation (37 percent). The most frequent indications of HTA influence were on decisions related to resource allocation (59 percent), change in practice pattern (31 percent), and incorporation of HTA details in reference material (18 percent). Few publications assessed the contribution of HTA to changing patient outcomes. CONCLUSIONS: The literature on HTA influence remains limited, with little on longer term effects on practice and outcomes. The reviewed publications indicated how HTA is being used in different settings and approaches to measuring its influence that might be more widely applied, such as surveys and monitoring administrative data.
Assuntos
Tomada de Decisões , Projetos de Pesquisa , Avaliação da Tecnologia Biomédica/métodos , Humanos , Disseminação de InformaçãoRESUMO
BACKGROUND: Despite the good safety of rivaroxaban, there is limited information on strategies for urgent reversal of its antihemostatic effects. METHODS AND RESULTS: Alterations of hemostasis induced by rivaroxaban (230 ng/ml) were assessed by using several tests applied to steady and circulating human blood. Effects on thrombin generation (TG) and thromboelastometry (TEM) parameters were measured. Modifications in platelet adhesive, aggregating and procoagulant activities were evaluated in studies with circulating blood. The potential reversal of prothrombin complex concentrates (PCCs; 50 IU/kg), activated PCCs (aPCCs; 75 IU/kg), or recombinant factor VIIa (rFVIIa; 270 µg/kg) was evaluated. Impairment of TG parameters induced by rivaroxaban were corrected by the different concentrates (aPCC≥PCC>rFVIIa). Prolonged clotting times and reduced clot firmness caused by rivaroxaban on TEM tests were improved by different concentrates (rFVIIa≥aPCC>PCC). Rivaroxaban significantly reduced platelets and fibrin interactions with damaged vascular surfaces in perfusion studies. While alterations of platelet interactions were favourably counteracted by rFVIIa or aPCCs, reductions in fibrin formation were only partially restored by the different factor concentrates (rFVIIa>aPCC≥PCC). CONCLUSIONS: Rivaroxaban-induced alterations on coagulation parameters measured through assays performed under static conditions were easily reversed by the different concentrates. Studies under flow conditions revealed that these concentrates normalized the action of rivaroxaban on platelets, and significantly improved fibrin formation; although in the later case, levels were not restored to the pre-treatment value.
Assuntos
Fatores de Coagulação Sanguínea/farmacologia , Fator VIII/farmacologia , Fator VIIIa/farmacologia , Hemostasia/efeitos dos fármacos , Rivaroxabana/farmacologia , HumanosRESUMO
BACKGROUND: The Atreus system (Terumo BCT) automates the preparation of blood components from whole blood donations. Intermediate platelet (PLT) products can be pooled manually or with the OrbiSac (Terumo BCT) and suspended in different PLT additive solutions (PASs) to obtain PLT concentrates (PCs). The aim of our study was to compare the in vitro PLT quality of PCs obtained with either the Atreus 2C+ and the OrbiSac or the Atreus 3C and suspended in PAS-II or PAS-IIIM during storage for up to 7 days. STUDY DESIGN AND METHODS: We prepared eight PCs from buffy coats obtained with Atreus 2C+, pooled with the OrbiSac, and suspended in PAS-II and eight PCs from interim PLT units obtained with the Atreus 3C and suspended either in PAS-II or in PAS-IIIM. We measured volume, PLT content, and mean PLT component and performed metabolic assays (pH, glucose, lactate, pO2, and pCO2) and flow cytometry analyses (GPIb, GPIIbIIIa, GPIV, CD62P, CD63, von Willebrand factor [vWF], fibrinogen, Factor V, and annexin V). RESULTS: PCs prepared with the Atreus 3C showed lower volume and higher PLT concentration when compared with PCs prepared with the Atreus 2C+ and the OrbiSac (p < 0.05). Glucose consumption rate and the expression of CD62P, CD63, and vWF were lower in PCs suspended in PAS-IIIM when compared with PCs suspended in PAS-II (p < 0.05). CONCLUSION: PCs prepared with the Atreus 3C and suspended in PAS-IIIM preserve satisfactorily the in vitro PLT quality during 7-day storage. PLT activation during a 7-day storage period was lower when the storage solution was PAS-IIIM in comparison with PAS-II.
Assuntos
Armazenamento de Sangue/métodos , Plaquetas/citologia , Preservação de Sangue/instrumentação , Preservação de Sangue/métodos , Transfusão de Plaquetas , Soluções/farmacologia , Plaquetas/metabolismo , Citometria de Fluxo , Humanos , Ativação Plaquetária , Contagem de Plaquetas , Fatores de TempoRESUMO
The transcription factor WRKY53 of the model plant Arabidopsis thaliana is an important regulator of leaf senescence. Its expression, activity and degradation are tightly controlled by various mechanisms and feedback loops. Hydrogen peroxide is one of the inducing agents for WRKY53 expression, and a long-lasting intracellular increase in H2O2 content accompanies the upregulation of WRKY53 at the onset of leaf senescence. We have identified different antioxidative enzymes, including catalases (CATs), superoxide dismutases (SODs) and ascorbate peroxidases (APXs), as protein interaction partners of WRKY53 in a WRKY53-pulldown experiment at different developmental stages. The interaction of WRKY53 with these enzymes was confirmed in vivo by bimolecular fluorescence complementation assays (BiFC) in Arabidopsis protoplasts and transiently transformed tobacco leaves. The interaction with WRKY53 inhibited the activity of the enzyme isoforms CAT2, CAT3, APX1, Cu/ZuSOD1 and FeSOD1 (and vice versa), while the function of WRKY53 as a transcription factor was also inhibited by these complex formations. Other WRKY factors like WRKY18 or WRKY25 had no or only mild inhibitory effects on the enzyme activities, indicating that WRKY53 has a central position in this crosstalk. Taken together, we identified a new additional and unexpected feedback regulation between H2O2, the antioxidative enzymes and the transcription factor WRKY53.
RESUMO
Q fever is a worldwide zoonotic disease which domestic ruminants are the main source of infection for humans. This scoping review summarizes the control measures currently available to reduce Coxiella burnetii (Cb) infection in naturally infected sheep, goat and cattle herds. A total of 28 articles were included in the review. A lack of methodological standardization was noted in the articles analyzed. The results indicated that long-term vaccination in cows reduces bacterial excretion in milk and environmental contamination. In small ruminants, the results of vaccination in terms of efficacy are variable. In goats, there is a reduction in bacterial excretion, unlike in sheep, where a long-term vaccination program is necessary to reduce bacterial excretion. Moreover, the high persistence of viable Cb in the environment means that control measures for sheep are needed for several years. The use of antibiotics as a control measure in cows and sheep was not found to reduce excretion. However, the combination of vaccination with antibiotic therapy appears to have positive effects in small ruminants in terms of controlling outbreaks of Q fever. Hygiene and biosecurity measures are the basic means for controlling Cb infection on ruminant farms and ensuring public health.
RESUMO
BACKGROUND: There were no previous studies about the quality of cryoprecipitate prepared from fresh-frozen plasma (FFP) inactivated with amotosalen and ultraviolet A (UVA) light. The aim of this study was to analyze the quantity and quality of coagulation factors in cryoprecipitate prepared from FFP treated with amotosalen and UVA light. STUDY DESIGN AND METHODS: FFP was obtained from whole blood donations and inactivated with amotosalen and UVA light according to the manufacturer's instructions. Fibrinogen, factor VIII (FVIII), von Willebrand factor antigen (VWF:Ag) and activity (VWF:RCo), the von Willebrand factor cleavage protease activity (ADAMTS-13), and the multimeric structure of VWF were analyzed. RESULTS: The content of fibrinogen, FVIII, and ADAMTS-13 was lower in cryoprecipitates prepared from amotosalen-treated plasma when compared with cryoprecipitates prepared from nontreated plasma (35, 40, and 18% loss, respectively). The quantity and quality of VWF as well as VWF multimer patterns were not affected by the inactivation method. CONCLUSION: Cryoprecipitates prepared from amotosalen-treated FFP contained significantly reduced levels of fibrinogen, FVIII, and ADAMTS-13. However, the VWF quantity and quality was well preserved.