RESUMO
Plants activate immunity upon recognition of pathogen-associated molecular patterns. Although phytopathogens have evolved a set of effector proteins to counteract plant immunity, some effectors are perceived by hosts and induce immune responses. Here, we show that two secreted ribonuclease effectors, SRN1 and SRN2, encoded in a phytopathogenic fungus, Colletotrichum orbiculare, induce cell death in a signal peptide- and catalytic residue-dependent manner, when transiently expressed in Nicotiana benthamiana. The pervasive presence of SRN genes across Colletotrichum species suggested the conserved roles. Using a transient gene expression system in cucumber (Cucumis sativus), an original host of C. orbiculare, we show that SRN1 and SRN2 potentiate host pattern-triggered immunity responses. Consistent with this, C. orbiculare SRN1 and SRN2 deletion mutants exhibited increased virulence on the host. In vitro analysis revealed that SRN1 specifically cleaves single-stranded RNAs at guanosine, leaving a 3'-end phosphate. Importantly, the potentiation of C. sativus responses by SRN1 and SRN2, present in the apoplast, depends on ribonuclease catalytic residues. We propose that the pathogen-derived apoplastic guanosine-specific single-stranded endoribonucleases lead to immunity potentiation in plants.
Assuntos
Cucumis sativus , Ribonucleases , Cucumis sativus/microbiologia , Fungos , Plantas , Imunidade , Doenças das Plantas/microbiologia , Imunidade VegetalRESUMO
In plants, the effective mobilization of seed nutrient reserves is crucial during germination and for seedling establishment. The Arabidopsis H+-PPase-loss-of-function fugu5 mutants exhibit a reduced number of cells in the cotyledons. This leads to enhanced post-mitotic cell expansion, also known as compensated cell enlargement (CCE). While decreased cell numbers have been ascribed to reduced gluconeogenesis from triacylglycerol, the molecular mechanisms underlying CCE remain ill-known. Given the role of indole 3-butyric acid (IBA) in cotyledon development, and because CCE in fugu5 is specifically and completely cancelled by ech2, which shows defective IBA-to-indoleacetic acid (IAA) conversion, IBA has emerged as a potential regulator of CCE. Here, to further illuminate the regulatory role of IBA in CCE, we used a series of high-order mutants that harbored a specific defect in IBA-to-IAA conversion, IBA efflux, IAA signaling, or vacuolar type H+-ATPase (V-ATPase) activity and analyzed the genetic interaction with fugu5-1. We found that while CCE in fugu5 was promoted by IBA, defects in IBA-to-IAA conversion, IAA response, or the V-ATPase activity alone cancelled CCE. Consistently, endogenous IAA in fugu5 reached a level 2.2-fold higher than the WT in 1-week-old seedlings. Finally, the above findings were validated in icl-2, mls-2, pck1-2 and ibr10 mutants, in which CCE was triggered by low sugar contents. This provides a scenario in which following seed germination, the low-sugar-state triggers IAA synthesis, leading to CCE through the activation of the V-ATPase. These findings illustrate how fine-tuning cell and organ size regulation depend on interplays between metabolism and IAA levels in plants.
Assuntos
Arabidopsis/fisiologia , Ácidos Indolacéticos/metabolismo , Indóis/farmacologia , Pirofosfatase Inorgânica/genética , ATPases Vacuolares Próton-Translocadoras/genética , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/genética , Crescimento Celular/efeitos dos fármacos , Cotilédone/efeitos dos fármacos , Cotilédone/genética , Cotilédone/fisiologia , Enoil-CoA Hidratase/genética , Germinação , Mutação com Perda de Função , Tamanho do Órgão , Transdução de Sinais/efeitos dos fármacos , Açúcares/metabolismoRESUMO
Multimeric abnormalities in plasma von Willebrand factor (VWF) cause bleeding or clotting disorders. Electrophoretic analysis of multimers is used to detect such abnormalities but is qualitative, slow, and difficult to standardize. Fluorescence correlation spectroscopy (FCS) is a good alternative but is affected by low selectivity and concentration bias. Here, we report the development of a homogeneous immunoassay based on dual-color fluorescence cross-correlation spectroscopy (FCCS) that overcomes these challenges. By performing a mild denaturation treatment followed by reacting with polyclonal antibodies, the concentration bias was drastically reduced. The use of a dual antibody assay improved selectivity. Diffusion times of immunolabeled VWF were measured with FCCS and standardized relative to calibrator measurements. The assay measures size changes in VWF using 1 µL of plasma and less than 10 ng of antibody per measurement and was validated over a 16-fold range of VWF antigen concentration (VWF:Ag), with a sensitivity of VWF:Ag 0.8%. Concentration bias and imprecision were less than 10%. Measurements were unaffected by hemolytic, icteric, or lipemic interference. Strong correlations were obtained with reference densitometric readouts (0.97 for calibrators, 0.85 for clinical samples), and significant differences were found between normal (n = 10), type 2A (n = 5), and type 2B (n = 5) von Willebrand's disease and acquired thrombotic thrombocytopenic purpura (n = 10) samples (p < 0.01). This FCCS based immunoassay accurately and selectively determines changes in the multimeric status of plasma VWF and may be used as a simpler, faster, and a standardizable alternative for multimer analysis, following further clinical validation in larger cohorts.
Assuntos
Doenças de von Willebrand , Fator de von Willebrand , Humanos , Fator de von Willebrand/análise , Fator de von Willebrand/química , Fator de von Willebrand/metabolismo , Doenças de von Willebrand/diagnóstico , Doenças de von Willebrand/tratamento farmacológico , Plasma/química , Imunoensaio , Análise EspectralRESUMO
Active membrane transport of plant hormones and their related compounds is an essential process that determines the distribution of the compounds within plant tissues and, hence, regulates various physiological events. Here, we report that the Arabidopsis NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER FAMILY 7.3 (NPF7.3) protein functions as a transporter of indole-3-butyric acid (IBA), a precursor of the major endogenous auxin indole-3-acetic acid (IAA). When expressed in yeast, NPF7.3 mediated cellular IBA uptake. Loss-of-function npf7.3 mutants showed defective root gravitropism with reduced IBA levels and auxin responses. Nevertheless, the phenotype was restored by exogenous application of IAA but not by IBA treatment. NPF7.3 was expressed in pericycle cells and the root tip region including root cap cells of primary roots where the IBA-to-IAA conversion occurs. Our findings indicate that NPF7.3-mediated IBA uptake into specific cells is required for the generation of appropriate auxin gradients within root tissues.
Assuntos
Proteínas de Transporte de Ânions/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Gravitropismo , Indóis/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Teste de Complementação Genética , Gravitropismo/efeitos dos fármacos , Ácidos Indolacéticos/química , Ácidos Indolacéticos/metabolismo , Ácidos Indolacéticos/farmacologia , Indóis/química , Indóis/farmacologia , Mutação/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genéticaRESUMO
BACKGROUND: We previously reported that polyphyllin D, the main component of the traditional herbal medicinal Paris polyphylla, exhibited anticancer effects in vitro against human neuroblastoma cells. The aim of this investigation was to examine in vivo antitumor effects of polyphyllin D. METHODS: Subcutaneous tumors were established in immune-deficient BALB/c nude mice using human neuroblastoma cell lines IMR-32 and LA-N-2. To evaluate the polyphyllin D activity, we used a mouse model of IMR-32 or LA-N-2 cell lines and analyzed subcutaneous tumors. RESULTS: Subcutaneous tumor models were successfully established in mice using two human neuroblastoma cell lines. In the subcutaneous tumor model, porphyrin D was found to suppress tumor volume. We found that polyphyllin D suppressed the number of foci by Ki-67 staining (IMR-32 and LA-N-2; p < 0.01, 0.02, respectively). We found that polyphyllin D induces the RIPK3 expression, while polyphyllin D phosphorylates Ser358 in IMR-32 and Ser358 and Tyr376 in LA-N-2. CONCLUSION: We developed a mouse model of subcutaneous tumors of neuroblastoma and demonstrated for the first time that polyphyllin D has an antitumor effect on neuroblastoma. Polyphyllin D can cause necroptosis depending on the cell type. The new drug can be expected by investigating a method to selectively induce cell death through the analysis of necroptosis.
Assuntos
Necroptose , Neuroblastoma , Animais , Camundongos , Humanos , Camundongos Nus , Morte Celular , Modelos Animais de Doenças , Neuroblastoma/tratamento farmacológicoRESUMO
Luminescent lanthanide coordination polymer crystals (LCPCs) represent an area of growing interest in materials chemistry owing to their unique and tailorable functional properties. The LCPCs provide a high level of structural tunability, including size- and morphology-dependent properties; therefore, they are promising materials for next-generation phosphors in a wide range of applications such as light emitting diodes. Here, by controlling the morphology of thermostable europium coordination polymer crystals, [Eu(hfa)3(dpbp)]n, hfa: hexafluoroacetylacetonate and dpbp:4,4'-bis(diphenylãphosphoryl) biphenyl), we realized a novel red phosphor with narrow linewidth emission (FWHM = 7.8 nm). The obtained luminescent LCPCs with unique structures were characterized by X-ray diffraction (XRD), scanning transmission electron microscopy (STEM), dynamic light scattering (DLS) and thermogravimetric analysis. Among, them, size tunable crystalline polymer spheres were found to have high internal quantum efficiency (ex., IQE = 79%) and highly thermostability (>300°C), and to exhibit dispersibility in PMMA media. The obtained results on the structural tunability of these materials can be used for the development of synthesis techniques for nanoscale materials based on crystalline lanthanide-based coordination phosphors.
RESUMO
A 77-year-old male patient was referred to our hospital because of jaundice. He was diagnosed with alcoholic liver cirrhosis and was admitted to our hospital because of liver failure. After admission, we observed conservative liver disease, but the liver damage did not improve and gradually worsened. Renal function deteriorated during liver failure. Hyperkalemia presented due to renal dysfunction. Hence, calcium polystyrene sulfonate (CPS) was initiated. He died because of liver failure although hyperkalemia improved. An autopsy revealed ulcer perforation with CPS crystals in the duodenum. A basic substance considered a crystal of CPS was found by hematoxylin and eosin staining from the ulcer adjacent to the perforation and the exudate attached to the peritoneum. Furthermore, a large amount of CPS crystals were found in the ascites. A final diagnosis of gastrointestinal perforation peritonitis due to CPS was made. Gastrointestinal perforation due to CPS is presumed as a direct mucosal injury due to the drug, most of which is the sigmoid colon of elderly patients. Upper gastrointestinal tract perforation is extremely rare. We experienced a case of autopsy in which duodenal perforation due to CPS was pathologically confirmed. CPS is a widely used drug for renal disorders, but it has a risk of gastrointestinal injury. Therefore, a potential gastrointestinal mucosal injury should be considered when using CPS.
Assuntos
Úlcera Duodenal , Hiperpotassemia , Falência Hepática , Masculino , Humanos , Idoso , Úlcera , Autopsia , Hiperpotassemia/etiologia , Úlcera Duodenal/complicaçõesRESUMO
Water scarcity is a serious agricultural problem causing significant losses to crop yield and product quality. The development of technologies to mitigate the damage caused by drought stress is essential for ensuring a sustainable food supply for the increasing global population. We herein report that the exogenous application of ethanol, an inexpensive and environmentally friendly chemical, significantly enhances drought tolerance in Arabidopsis thaliana, rice and wheat. The transcriptomic analyses of ethanol-treated plants revealed the upregulation of genes related to sucrose and starch metabolism, phenylpropanoids and glucosinolate biosynthesis, while metabolomic analysis showed an increased accumulation of sugars, glucosinolates and drought-tolerance-related amino acids. The phenotyping analysis indicated that drought-induced water loss was delayed in the ethanol-treated plants. Furthermore, ethanol treatment induced stomatal closure, resulting in decreased transpiration rate and increased leaf water contents under drought stress conditions. The ethanol treatment did not enhance drought tolerance in the mutant of ABI1, a negative regulator of abscisic acid (ABA) signaling in Arabidopsis, indicating that ABA signaling contributes to ethanol-mediated drought tolerance. The nuclear magnetic resonance analysis using 13C-labeled ethanol indicated that gluconeogenesis is involved in the accumulation of sugars. The ethanol treatment did not enhance the drought tolerance in the aldehyde dehydrogenase (aldh) triple mutant (aldh2b4/aldh2b7/aldh2c4). These results show that ABA signaling and acetic acid biosynthesis are involved in ethanol-mediated drought tolerance and that chemical priming through ethanol application regulates sugar accumulation and gluconeogenesis, leading to enhanced drought tolerance and sustained plant growth. These findings highlight a new survival strategy for increasing crop production under water-limited conditions.
Assuntos
Arabidopsis , Secas , Ácido Abscísico/metabolismo , Arabidopsis/metabolismo , Etanol/metabolismo , Regulação da Expressão Gênica de Plantas , Estômatos de Plantas/fisiologia , Plantas Geneticamente Modificadas/metabolismo , Estresse Fisiológico/genética , Açúcares/metabolismo , Água/metabolismoRESUMO
High-order Gaussian beams with multiple propagation modes have been studied for free-space optical communications. Fast classification of beams using a diffractive deep neural network (D2NN) has been proposed. D2NN optimization is important because it has numerous hyperparameters, such as interlayer distances and mode combinations. In this study, we classify Hermite-Gaussian beams, which are high-order Gaussian beams, using a D2NN, and automatically tune one of its hyperparameters known as the interlayer distance. We used the tree-structured Parzen estimator, a hyperparameter auto-tuning algorithm, to search for the best model. As a result, the proposed method improved the classification accuracy in a 16 mode classification from 98.3% in the case of equal spacing of layers to 98.8%. In a 36 mode classification, the proposed method significantly improved the classification accuracy from 84.9% to 94.9%. In addition, we confirmed that accuracy by auto-tuning improves as the number of classification modes increases.
RESUMO
PURPOSE: We previously reported that polyphyllin D, a main component of the traditional Chinese medicinal herb Paris polyphylla, exhibited anticancer effects in vitro against human neuroblastoma cells. The aims of this investigation was to examine the presence or absence of in vivo anti-metastasis effects of polyphyllin D were to establish a liver metastasis model of neuroblastoma and to evaluate the anti-metastasis effects of polyphyllin D. METHODS: Subcutaneous and intraperitoneal tumors, and metastasis models were established in immune-deficient BALB/c nude and BALB/c Rag-2/Jak3 double-deficient (BRJ) mice using the human neuroblastoma cell lines IMR-32, LA-N-2, or NB-69. For evaluating polyphyllin D activity, we used a mouse model of liver metastasis with the IMR-32 cells line injected through the tail vein. We analyzed the livers number and area of liver tumors in of the phosphate buffer solution- and polyphyllin D-treated groups. RESULTS: Liver metastasis and intraperitoneal dissemination models were successfully established in immune-deficient BRJ mice using the three human neuroblastoma cell lines. In the liver metastasis, the model of IMR-32 cells, we found that polyphyllin D suppressed both the number and total area of metastatic foci the average number of metastatic foci, average focus areas, and number of cleaved caspase-3-positive cells were significantly lower in the polyphyllin D group (p = 0.016, 0.020, 0.043, respectively). CONCLUSIONS: We developed a mouse models of neuroblastoma metastasis and demonstrated for the first time that polyphyllin D has an antitumor effect on neuroblastoma liver metastases.
Assuntos
Diosgenina , Neoplasias Hepáticas , Neuroblastoma , Animais , Apoptose , Linhagem Celular Tumoral , Diosgenina/análogos & derivados , Diosgenina/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Camundongos , Neuroblastoma/tratamento farmacológico , Neuroblastoma/patologia , SaponinasRESUMO
Bundle Sheath Defective 2, BSD2, is a stroma-targeted protein initially identified as a factor required for the biogenesis of ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO) in maize. Plants and algae universally have a homologous gene for BSD2 and its deficiency causes a RuBisCO-less phenotype. As RuBisCO can be the rate-limiting step in CO2 assimilation, the overexpression of BSD2 might improve photosynthesis and productivity through the accumulation of RuBisCO. To examine this hypothesis, we produced BSD2 overexpression lines in Arabidopsis. Compared with wild type, the BSD2 overexpression lines BSD2ox-2 and BSD2ox-3 expressed 4.8-fold and 8.8-fold higher BSD2 mRNA, respectively, whereas the empty-vector (EV) harbouring plants had a comparable expression level. The overexpression lines showed a significantly higher CO2 assimilation rate per available CO2 and productivity than EV plants. The maximum carboxylation rate per total catalytic site was accelerated in the overexpression lines, while the number of total catalytic sites and RuBisCO content were unaffected. We then isolated recombinant BSD2 (rBSD2) from E. coli and found that rBSD2 reduces disulfide bonds using reductants present in vivo, for example glutathione, and that rBSD2 has the ability to reactivate RuBisCO that has been inactivated by oxidants. Furthermore, 15% of RuBisCO freshly isolated from leaves of EV was oxidatively inactivated, as compared with 0% in BSD2-overexpression lines, suggesting that the overexpression of BSD2 maintains RuBisCO to be in the reduced active form in vivo. Our results demonstrated that the overexpression of BSD2 improves photosynthetic efficiency in Arabidopsis and we conclude that it is involved in mediating RuBisCO activation.
Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Fotossíntese/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/fisiologia , Escherichia coli , Regulação da Expressão Gênica de Plantas , Proteínas Recombinantes , Ribulose-Bifosfato Carboxilase/metabolismoRESUMO
Blood based ß-amyloid (Aß) assays that can predict amyloid positivity in the brain are in high demand. Current studies that utilize immunoprecipitation mass spectrometry assay (IP-MS), which has high specificity for measuring analytes, have revealed that precise plasma Aß assays have the potential to detect amyloid positivity in the brain. In this study, we developed plasma Aß40 and Aß42 immunoassays using a fully automated immunoassay platform that is used in routine clinical practice. Our assays showed high sensitivity (limit of quantification: 2.46 pg/mL [Aß40] and 0.16 pg/mL [Aß42]) and high reproducibility within-run (coefficients of variation [CVs]: <3.7% [Aß40] and <2.0% [Aß42]) and within-laboratory (CVs: <4.6% [Aß40] and <5.3% [Aß42]). The interference from plasma components was less than 10%, and the cross-reactivity with various lengths of Aß peptides was less than 0.5%. In addition, we found a significant correlation between the IP-MS method and our immunoassay (correlation coefficients of Pearson's r: 0.91 [Aß40] and 0.82 [Aß42]). Our new method to quantify plasma Aß40 and Aß42 provides clinicians and patients with a way to continuously monitor disease progression.
Assuntos
Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/sangue , Técnicas Imunoenzimáticas/métodos , Imunoprecipitação/métodos , Espectrometria de Massas/métodos , Fragmentos de Peptídeos/sangue , Plasma/metabolismo , Doença de Alzheimer/sangue , Biomarcadores/sangue , Humanos , Luminescência , Reprodutibilidade dos TestesRESUMO
We investigated the recent epidemiology and characteristics of influenza-related hospitalization in Japanese children. This study included 3741 children with influenza. Children hospitalized for febrile seizures (FS) induced by etiologies other than influenza also served as a disease control. Most outpatients (92.8%) visited our hospital with complaints of respiratory symptoms, whereas FS were the most predominant symptoms of inpatients (58/154, 37.7%). Children with influenza-induced FS were significantly older than those with FS induced by other etiologies (P <0.001). Although the characteristics of severe influenza may vary throughout the world, the analysis of influenza-induced neurological disorders is important for understanding its epidemiology.
Assuntos
Hospitalização/estatística & dados numéricos , Influenza Humana/complicações , Infecções Respiratórias/epidemiologia , Convulsões Febris/epidemiologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Vírus da Influenza A/genética , Vírus da Influenza A/patogenicidade , Influenza Humana/epidemiologia , Japão , Masculino , Infecções Respiratórias/virologia , Estudos Retrospectivos , Convulsões Febris/etiologiaRESUMO
BACKGROUND: Endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/B) is a standard method for pathological diagnosis of pancreatic solid lesions. The EchoTip ProCore 20G® (PC20), a 20-gauge biopsy needle with a forward-bevel core trap, has been available in Japan since 2015. METHODS: We compared the efficacy of the PC20 with that of the EchoTip ProCore 22G® (PC22) and Acquire 22G® (AC22) in EUS-FNA/B for diagnosing pancreatic cancer. This retrospective study included 191 patients with pancreatic cancer who underwent EUS-FNA/B using the PC20, PC22, or AC22 at our facility from April 2013 to October 2019. We investigated the patients' clinical characteristics and the diagnostic accuracy and safety of each needle. RESULTS: A sufficient stroke length of puncture was secured in all patients. The maximum length under EUS was shorter with the AC22 (22.1 ± 2.2 mm) than PC20 (30.6 ± 0.7 mm, p < 0.01) and PC22 (30.3 ± 0.8 mm, p < 0.01). The histological accuracy was 96.4% with the PC20 but only 58.8% with the PC22 (adjusted p (p-adj) < 0.0001) and 75.0% with the AC22 (p-adj = 0.06). The diagnostic accuracy of the combination of histology and cytology was 96.4% with the PC20, while it was 72.1% with the PC22 (p-adj < 0.0001) and 91.7% with the AC22 (p-adj > 0.99). One patient (0.9%) in the PC20 group developed mild pancreatitis, but no adverse events occurred with the other needles. CONCLUSIONS: The PC20 showed better diagnostic capability than the PC22. The diagnostic efficacy was similar between the PC20 and AC22. The high histological accuracy of the PC20 could be advantageous for lesions in which histological assessment is critical.
Assuntos
Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico , Neoplasias Pancreáticas , Humanos , Japão , Agulhas , Pâncreas/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Estudos Prospectivos , Estudos RetrospectivosRESUMO
BACKGROUND: Large numbers of patients with diseases preventable by voluntary vaccines have been reported in Japan. However, it is difficult to analyze the impact of voluntary vaccination on disease prevention, as governments do not aggregate the number of recipients of vaccines that are not included in the national immunization program. This study investigated the association between the coverage rates of two voluntary vaccines (rotavirus and mumps vaccines) and the incidence of the diseases preventable by these vaccines. METHODS: We performed a prospective questionnaire-based observational study to investigate the presumptive coverage rates of the rotavirus vaccine in infancy and the mumps vaccine at 1 year of age in Kitakyushu City from 2015 to 2018. The number of children admitted to a secondary medical institution for rotavirus-associated gastroenteritis and the incidence of mumps infection in sentinel medical institutions were also analyzed during the investigation period. RESULTS: The rotavirus and mumps vaccine coverage rates since 2016 were 61-63% and late 28-30%, respectively (52.6% and 20.3% in 2015, respectively). The yearly number of children hospitalized for rotavirus-associated gastroenteritis from 2015 to 2018 declined by 41.4% compared with that during the pre-vaccination period (2009-2011). The incidence of mumps infection remained unchanged during the investigation period. CONCLUSION: The coverage rates of two voluntary vaccines were not high enough to control the infections. The incorporation of voluntary vaccines into the routine immunization program should be considered as the one of the effective ways to increase vaccination coverage.
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Gastroenterite , Infecções por Rotavirus , Vacinas contra Rotavirus , Criança , Humanos , Lactente , Japão/epidemiologia , Estudos Prospectivos , Vacinação , Cobertura VacinalRESUMO
The phytohormone abscisic acid (ABA) is produced via a multistep de novo biosynthesis pathway or via single-step hydrolysis of inactive ABA-glucose ester (ABA-GE). The hydrolysis reaction is catalyzed by ß-glucosidase (BG, or BGLU) isoforms localized to various organelles, where they become activated upon stress, but the mechanisms underlying this organelle-specific activation remain unclear. We investigated the relationship between the subcellular distribution and stress-induced activation of BGLU18 (BG1), an endoplasmic reticulum enzyme critical for abiotic stress responses, in Arabidopsis thaliana leaves. High BGLU18 levels were present in leaf petioles, primarily in endoplasmic reticulum bodies. These Brassicaceae-specific endoplasmic reticulum-derived organelles responded dynamically to abiotic stress, particularly drought-induced dehydration, by changing in number and size. Under stress, BGLU18 distribution shifted toward microsomes, which was accompanied by increasing BGLU18-mediated ABA-GE hydrolytic activity and ABA levels in leaf petioles. Under non-stress conditions, impaired endoplasmic reticulum body formation caused a microsomal shift of BGLU18 and increased its enzyme activity; however, ABA levels increased only under stress, probably because ABA-GE is supplied to the endoplasmic reticulum only under these conditions. Loss of BGLU18 delayed dehydration-induced ABA accumulation, suggesting that ABA-GE hydrolysis precedes the biosynthesis. We propose that dynamics of the endoplasmic reticulum modulate ABA homeostasis and abiotic stress responses by activating BGLU18-mediated ABA-GE hydrolysis.
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Ácido Abscísico , Proteínas de Arabidopsis , Proteínas de Arabidopsis/metabolismo , Retículo Endoplasmático/metabolismo , Ésteres , Regulação da Expressão Gênica de Plantas , Folhas de Planta/metabolismo , Estresse Fisiológico , beta-Glucosidase/genéticaRESUMO
BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is still performed using two-dimensional (2D) X-ray images. The success rate and risk of complications are considered operator-dependent. We explored performing an ERCP-related procedure with 3D-computed tomography (CT) biliary imaging for preoperative simulation and intraoperative reference in a patient with malignant biliary obstruction. CASE PRESENTATION: The patient was a 66-year-old man who underwent rectal resection and postoperative chemotherapy for rectal cancer. A liver metastasis caused obstructive jaundice and acute cholangitis, necessitating emergency hospitalization. A 3.5 cm mass in the hilar region of the biliary tree caused type IV biliary obstruction according to the Bismuth-Corlette classification of hilar cholangiocarcinoma. ERCP and biliary drainage were performed repeatedly, but had no effect. Given that selective bile duct drainage had proven extremely difficult with the conventional procedures, three-dimensional (3D) images were created from preoperative CT image data using a 3D image reconstruction system (SYNAPSE VINCENT version 5, FUJIFILM Corporation, Tokyo, Japan). Using the 3D images for preoperative planning and intraoperative reference, biliary drainage and stent placement were successfully performed without complications. Postoperatively, the patient had no further cholangitis or need for stent replacement up to his death. CONCLUSIONS: We report the first case of an ERCP-related procedure with 3D biliary imaging for preoperative simulation and intraoperative reference in a patient with malignant biliary obstruction. The 3D image reconstruction is useful for preoperative planning and could contribute to an increased success rate, decreased complications, a shorter operation time, and reduced radiation exposure to the operator.
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Neoplasias dos Ductos Biliares/diagnóstico por imagem , Colangiopancreatografia Retrógrada Endoscópica/métodos , Imageamento Tridimensional/métodos , Tumor de Klatskin/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Idoso , Ductos Biliares Intra-Hepáticos/diagnóstico por imagem , Humanos , MasculinoRESUMO
The most important factors determining the prognosis of patients with acute cholangitis (AC) are prompt biliary drainage and appropriate choice of antibiotics. This study was performed to evaluate whether dividing the number of doses based on the PK-PD theory contributes to better clinical outcome in the management of acute cholangitis. We measured ceftriaxone levels in blood and bile in 21 cases diagnosed with moderate-to-severe AC. Eleven cases were administered 2 g of ceftriaxone once-daily (group A) and 10 cases were given 1 g of ceftriaxone twice-daily (group B). The theoretical effect of ceftriaxone was evaluated by pharmacokinetic-pharmacodynamic (PK-PD) parameters. Clinical efficacy was evaluated by body temperature, white blood cell count and serum levels of C-reactive protein. Minimum level of ceftriaxone in serum (in mg/L) in groups A and B at 24 h after the first dose was 9.1 and 9.2, whereas that in bile was 2.9 and 2.5, respectively. The minimum inhibitory concentration (MIC) of ceftriaxone for all isolated bacteria was below the minimum serum and biliary concentration of ceftriaxone 24 h after the first administration (except for Enterococcus species). The MIC for isolated bacterial strains was <16 mg/L, which is the PK-PD breakpoint for ceftriaxone at 2 g/day. Both regimens showed clinical efficacy and did not contradict the effect predicted based on PK-PD.
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Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/terapia , Ceftriaxona/farmacologia , Colangite/terapia , Doença Aguda/terapia , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Bactérias/isolamento & purificação , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/microbiologia , Proteína C-Reativa/análise , Ceftriaxona/uso terapêutico , Colangite/diagnóstico , Colangite/microbiologia , Relação Dose-Resposta a Droga , Drenagem/métodos , Esquema de Medicação , Endoscopia do Sistema Digestório , Feminino , Humanos , Contagem de Leucócitos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do TratamentoRESUMO
PURPOSE: Arctigenin has been shown to have anti-tumor effects in various types of cancers. This study was conducted to verify these effects in the human-derived hepatoblastoma cell line, HUH-6 clone 5 (hereinafter, HUH-6). METHODS: Arctigenin was added to cultured HUH-6 cells, and cellular activity was evaluated by MTS assay. To determine the relationship between reduced cellular activity and apoptosis, we measured the activities of caspase 3/7, 8, and 9 and conducted flow cytometry with Annexin V/PI staining. RESULTS: The MTS assay revealed that cellular activity decreased after arctigenin treatment in a concentration-dependent manner (IC50 = 4 µM). To investigate apoptosis induction, activity assays of caspase 3/7, 8, and 9 were performed. While caspase 3/7 and 8 exhibited high activity, caspase 9 showed no activity. Thus, apoptosis induction may have involved the action of tumor necrosis factor receptor 1 (TNFR1). Flow cytometry conducted with Annexin V/PI staining revealed the occurrence of early apoptosis. CONCLUSION: We found that arctigenin has anti-tumor effects in HUH-6 cells in a concentration-dependent manner. Arctigenin may have exerted its anti-tumor effect by inducing apoptosis via TNFR1, which recruits Complex IIa to activate caspase 8 and 3/7. These results may be useful for developing therapeutic agents for hepatoblastoma.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Furanos/farmacologia , Hepatoblastoma/patologia , Lignanas/farmacologia , Neoplasias Hepáticas/patologia , Linhagem Celular Tumoral , Células Cultivadas , HumanosRESUMO
BACKGROUND: The ureides allantoin and allantoate are major metabolic intermediates of purine catabolism with high nitrogen-to-carbon ratios. Ureides play a key role in nitrogen utilization in ureide-type legumes, but their effects on growth and development in non-legume plants are poorly understood. Here, we examined the effects of knocking out genes encoding ureide-degrading enzymes, allantoinase (ALN) and allantoate amidohydrolase (AAH), on the vegetative-to-reproductive transition and subsequent growth of Arabidopsis plants. RESULTS: The ureide-degradation mutants (aln and aah) showed symptoms similar to those of nitrogen deficiency: early flowering, reduced size at maturity, and decreased fertility. Consistent with these phenotypes, carbon-to-nitrogen ratios and nitrogen-use efficiencies were significantly decreased in ureide-degradation mutants; however, adding nitrogen to irrigation water did not alleviate the reduced growth of these mutants. In addition to nitrogen status, levels of indole-3-acetic acid and gibberellin in five-week-old plants were also affected by the aln mutations. To test the possibility that ureides are remobilized from source to sink organs, we measured ureide levels in various organs. In wild-type plants, allantoate accumulated predominantly in inflorescence stems and siliques; this accumulation was augmented by disruption of its catabolism. Mutants lacking ureide transporters, ureide permeases 1 and 2 (UPS1 and UPS2), exhibited phenotypes similar to those of the ureide-degradation mutants, but had decreased allantoate levels in the reproductive organs. Transcript analysis in wild-type plants suggested that genes involved in allantoate synthesis and ureide transport were coordinately upregulated in senescing leaves. CONCLUSIONS: This study demonstrates that ureide degradation plays an important role in supporting healthy growth and development in non-legume Arabidopsis during and after transition from vegetative to reproductive stages.