RESUMO
Translational control of gene expression plays a key role in many biological processes. Consequently, the activity of the translation apparatus is under tight homeostatic control. eIF4E, the mRNA 5' cap-binding protein, facilitates cap-dependent translation and is a major target for translational control. eIF4E activity is controlled by a family of repressor proteins, termed 4E-binding proteins (4E-BPs). Here, we describe the surprising finding that despite the importance of eIF4E for translation, a drastic knockdown of eIF4E caused only minor reduction in translation. This conundrum can be explained by the finding that 4E-BP1 is degraded in eIF4E-knockdown cells. Hypophosphorylated 4E-BP1, which binds to eIF4E, is degraded, whereas hyperphosphorylated 4E-BP1 is refractory to degradation. We identified the KLHL25-CUL3 complex as the E3 ubiquitin ligase, which targets hypophosphorylated 4E-BP1. Thus, the activity of eIF4E is under homeostatic control via the regulation of the levels of its repressor protein 4E-BP1 through ubiquitination.
Assuntos
Fator de Iniciação 4E em Eucariotos/genética , Fator de Iniciação 4E em Eucariotos/metabolismo , Proteínas de Ligação ao Cap de RNA/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Proteínas de Ciclo Celular , Células HEK293 , Células HeLa , Homeostase , Humanos , Camundongos , Modelos Biológicos , Dados de Sequência Molecular , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Biossíntese de Proteínas , Proteínas de Ligação ao Cap de RNA/metabolismo , Transfecção , Ubiquitina/metabolismoRESUMO
Aided by Structure Based Drug Discovery (SBDD), we rapidly designed a highly novel and selective series of mTOR inhibitors. This chemotype conveys exquisite kinase selectivity, excellent in vitro and in vivo potencies and ADME safety profiles. These compounds could serve as good tools to explore the potential of TORC inhibition in various human diseases.
Assuntos
Furanos/química , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/metabolismo , Piridinas/química , Pirimidinas/química , Serina-Treonina Quinases TOR/antagonistas & inibidores , Ligação Competitiva , Descoberta de Drogas , Humanos , Modelos Moleculares , Estrutura Molecular , Morfolinas/química , Fosfatidilinositol 3-Quinase/química , Ligação Proteica , Relação Estrutura-AtividadeRESUMO
In this study, we reveal that liver organoid transplantation through the portal vein is a safe and effective method for the treatment of chronic liver damage. The liver organoids significantly reconstituted the hepatocytes; hence, the liver was significantly enlarged in this group, compared to the monolayer cell transplantation group in the retrorsine/partial hepatectomy (RS/PH) model. In the liver organoid transplantation group, the bile ducts were located in the donor area and connected to the recipient bile ducts. Thus, the rate of bile reconstruction in the liver was significantly higher compared to that in the monolayer group. By transplanting liver organoids, we saw a level of 70% replacement of the damaged liver. Consequently, in the transplantation group, diminished ductular reaction and a decrease of placental glutathione S-transferase (GST-p) precancerous lesions were observed. After trans-portal injection, the human induced pluripotent stem cell (hiPSC)-derived liver organoids revealed no translocation outside the liver; in contrast, the monolayer cells had spread to the lungs. The hiPSC-derived liver organoids were attached to the liver in the immunodeficient RS/PH rats. This study clearly demonstrates that liver organoid transplantation through the portal vein is a safe and effective method for the treatment of chronic liver damage in rats.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/terapia , Transplante de Fígado/métodos , Organoides/citologia , Veia Porta/cirurgia , Alcaloides de Pirrolizidina/efeitos adversos , Animais , Células Cultivadas , Feminino , Glutationa Transferase/metabolismo , Hepatectomia , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Regeneração Hepática , Técnicas de Cultura de Órgãos , Ratos , Resultado do TratamentoRESUMO
It has been hypothesized that selective inhibition of phosphodiesterase (PDE) 2A could potentially be a novel approach to treat cognitive impairment in neuropsychiatric and neurodegenerative disorders through augmentation of cyclic nucleotide signaling pathways in brain regions associated with learning and memory. Following our earlier work, this article describes a drug design strategy for a new series of lead compounds structurally distinct from our clinical candidate 2 (TAK-915), and subsequent medicinal chemistry efforts to optimize potency, selectivity over other PDE families, and other preclinical properties including in vitro phototoxicity and in vivo rat plasma clearance. These efforts resulted in the discovery of N-((1S)-2-hydroxy-2-methyl-1-(4-(trifluoromethoxy)phenyl)propyl)-6-methyl-5-(3-methyl-1H-1,2,4-triazol-1-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide (20), which robustly increased 3',5'-cyclic guanosine monophosphate (cGMP) levels in the rat brain following an oral dose, and moreover, attenuated MK-801-induced episodic memory deficits in a passive avoidance task in rats. These data provide further support to the potential therapeutic utility of PDE2A inhibitors in enhancing cognitive performance.
Assuntos
Transtornos Cognitivos/tratamento farmacológico , Nucleotídeo Cíclico Fosfodiesterase do Tipo 2/antagonistas & inibidores , Descoberta de Drogas , Inibidores de Fosfodiesterase/farmacologia , Pirazinas/farmacologia , Pirazóis/farmacologia , Piridinas/farmacologia , Pirimidinas/farmacologia , Células 3T3 , Administração Oral , Animais , Células COS , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Transtornos Cognitivos/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 2/metabolismo , Relação Dose-Resposta a Droga , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos ICR , Estrutura Molecular , Inibidores de Fosfodiesterase/administração & dosagem , Inibidores de Fosfodiesterase/química , Difração de Pó , Pirazinas/química , Pirazóis/química , Piridinas/química , Pirimidinas/química , Ratos , Ratos Long-Evans , Solubilidade , Relação Estrutura-Atividade , TermodinâmicaRESUMO
OBJECTIVE: Vitamin B6 deficiency is common in hemodialysis patients and may contribute to anemia and abnormal bone metabolism in this population. DESIGN: 6-month, open-label, randomized controlled parallel-group study in hemodialysis centers. SUBJECTS: Fifty-six maintenance hemodialysis patients with relatively high resistance to erythropoiesis-stimulating agents (ESA). INTERVENTION: Intravenous vitamin B6 (60 mg of intravenous pyridoxal 5'-phosphate after each thrice-weekly hemodialysis session). MAIN OUTCOME MEASURE: The primary and secondary outcomes were changes over time in ESA resistance index and bone turnover markers, respectively. RESULTS: The prevalence of vitamin B6 deficiency was 40% overall. Compared with the control group, the B6 group showed an upward change in ESA resistance index over time (Pinteraction = .038). At week 13 (a priori-defined time point), pyridoxal 5'-phosphate administration was associated with higher ESA resistance index by 0.97 (95% confidence interval, 0.02-1.92) ×10-2 µg â darbepoetin-α/kg per g/dLâ hemoglobin after baseline adjustment, which was not modified by baseline vitamin B6 status. There was a trend toward increase in serum erythropoietin concentrations in the B6 group after adjustment for baseline values, hemoglobin, and weekly ESA dose (Pinteraction = .06). The downward changes of bone-specific alkaline phosphatase and tartrate-resistant acid phosphatase 5b in the B6 group relative to the control group were pronounced in patients without vitamin B6 deficiency (Pinteraction < .001 and .017, respectively), despite nonsignificant between-group difference in 1-84 parathyroid hormone. CONCLUSIONS: Thrice-weekly intravenous vitamin B6 (60 mg pyridoxal 5'-phosphate hydrate) worsens the response to ESA and may blunt the response of bone to parathyroid hormone in hemodialysis patients.
Assuntos
Eritropoese/efeitos dos fármacos , Hematínicos/uso terapêutico , Diálise Renal , Vitamina B 6/uso terapêutico , Anemia , Osso e Ossos/metabolismo , Humanos , Hormônio Paratireóideo/fisiologiaRESUMO
The genomic RNA of encephalomyocarditis virus (EMCV) encodes a single polyprotein, and the primary scission of the polyprotein occurs between nonstructural proteins 2A and 2B by an unknown mechanism. To gain insight into the mechanism of 2A-2B processing, we first translated the 2A-2B region in vitro with eukaryotic and prokaryotic translation systems. The 2A-2B processing occurred only in the eukaryotic systems, not in the prokaryotic systems, and the unprocessed 2A-2B protein synthesized by a prokaryotic system remained uncleaved when incubated with a eukaryotic cell extract. These results suggest that 2A-2B processing is a eukaryote-specific, co-translational event. To define the translation factors required for 2A-2B processing, we constituted a protein synthesis system with eukaryotic elongation factors 1 and 2, eukaryotic release factors 1 and 3 (eRF1 and eRF3), aminoacyl-tRNA synthetases, tRNAs, ribosome subunits, and a plasmid template that included the hepatitis C virus internal ribosome entry site. We successfully reproduced 2A-2B processing in the reconstituted system even without eRFs. Our results indicate that this unusual event occurs in the elongation phase of translation.
Assuntos
Vírus da Encefalomiocardite/metabolismo , Fator de Iniciação 2 em Eucariotos/metabolismo , Fator 1 de Elongação de Peptídeos/metabolismo , Biossíntese de Proteínas , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/metabolismo , Proteínas Virais/metabolismo , Alanina/genética , Aminoacil-tRNA Sintetases/metabolismo , Sítios de Ligação , Sistema Livre de Células , DNA Complementar/metabolismo , Deleção de Genes , Regulação da Expressão Gênica , Células HeLa , Hepacivirus/metabolismo , Humanos , Mutação , Fases de Leitura Aberta , Plasmídeos/metabolismo , Dobramento de Proteína , Ribossomos/químicaRESUMO
Osteoporosis is one of the major complications of glucocorticoid therapy. Osteoporosis is usually defined by the levels of bone mineral density (BMD) assessed by dual energy X-ray absorptiometry (DEXA); however, glucocorticoids often induce fractures in patients with normal BMD. Thus, novel diagnostic approaches are required. In this study, we examined whether multidetector-row computed tomography (MDCT) is useful to assess the bone status in glucocorticoid-induced osteoporosis (GIO). Because bisphosphonates have been proven to prevent bone fracture in GIO, we tried to detect the therapeutic effects of bisphosphonates in GIO by MDCT. Fifteen Japanese patients with immunoglobulin A nephropathy who had normal renal function were enrolled in this open-label randomized trial. Patients were randomly divided into three groups-calcitriol (VD), menatetrenone (VK), or bisphosphonate (Bis). Bone conditions were analyzed twice by three different methods-bone turnover markers, DEXA, and MDCT-at the start and 6 months after the start of therapy. Both bone markers and DEXA could not detect significant differences among the therapeutic groups; however, MDCT-based analyses detected the preventive effects of bisphosphonates in GIO. Compared to VD, Bis improved structural indices, such as bone volume fraction, trabecular separation, marrow star volume, and structure model index whereas the difference between VD and VK was not significant. Finite element analysis revealed that simulated fracture load in the Bis group was significantly improved. These findings suggested that MDCT-based assessment is superior to bone markers and/or DEXA in assessing the therapeutic effect of bisphosphonates on GIO.
Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Difosfonatos/uso terapêutico , Glucocorticoides/efeitos adversos , Osteoporose/induzido quimicamente , Osteoporose/tratamento farmacológico , Adolescente , Adulto , Biomarcadores/metabolismo , Densidade Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Calcitriol/uso terapêutico , Feminino , Glucocorticoides/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores/métodos , Estudos Prospectivos , Vitamina K 2/análogos & derivados , Vitamina K 2/uso terapêutico , Adulto JovemRESUMO
The serum glycoprotein fetuin-A is an important inhibitor of extraosseous calcification. The importance of fetuin-A has been confirmed in fetuin-A null mice, which develop widespread extraosseous calcification including the kidney. However, the mechanism how fetuin-A protects kidneys from nephrocalcinosis remains uncertain. Here, we demonstrate that intratubular fetuin-A plays a role in the prevention of nephrocalcinosis in the proximal tubules. Although normal rat kidney did not express mRNA for fetuin-A, we found punctate immunohistochemical staining of fetuin-A mainly in the S1 segment of the proximal tubules. The staining pattern suggested that fetuin-A passed through the slit diaphragm, traveled in the proximal tubular lumen, and was introduced into proximal tubular cells by megalin-mediated endocytosis. To test this hypothesis, we inhibited the function of megalin by intravenous injection of histidine-tagged soluble receptor-associated protein (His-sRAP), a megalin inhibitor. His-sRAP injection diminished fetuin-A staining in the proximal tubules and led to urinary excretion of fetuin-A. We further analyzed the role of fetuin-A in nephrocalcinosis. Continuous injection of parathyroid hormone (PTH) 1-34 induced nephrocalcinosis mainly in the proximal tubules in rats. His-sRAP retained fetuin-A in renal tubular lumen and thereby protected the kidneys of PTH-treated rats from calcification. Our findings suggest that tubular luminal fetuin-A works as a natural inhibitor against calcification in the proximal tubules under PTH-loaded condition.
Assuntos
Túbulos Renais Proximais/metabolismo , Nefrocalcinose/metabolismo , Nefrocalcinose/prevenção & controle , alfa-2-Glicoproteína-HS/metabolismo , Animais , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade/antagonistas & inibidores , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Lisossomos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos WistarRESUMO
The eukaryotic cytosolic chaperonin CCT (chaperonin-containing TCP-1) assists folding of newly synthesized polypeptides. The fully functional CCT is built from two identical rings, each composed of single copies of eight distinct subunits. To study the structure and function of the CCT complex and the role of each subunit, a rapid and efficient method for preparing a recombinant CCT complex is needed. In this work, we established an efficient expression and purification method to obtain human recombinant CCT. BHK-21 cells were infected with a vaccinia virus expressing T7 RNA polymerase and transfected with eight plasmids, each encoding any one of the eight CCT subunits in the T7 RNA polymerase promoter/terminator unit. The CCT1 subunit was engineered to carry a hexa-histidine tag or FLAG tag in the internal loop region. Three days later, cells were harvested for purification of the CCT complex through tag-dependent affinity chromatography and gel filtration. The purified recombinant CCT complexes were indistinguishable from the endogenous CCT purified from HeLa cells in terms of morphology and function. In conclusion, the co-expression system established in this study should be a simple and powerful tool for reconstitution of a large multi-subunit complex.
Assuntos
Chaperonina com TCP-1/química , Chaperonina com TCP-1/genética , Subunidades Proteicas/química , Subunidades Proteicas/genética , Sequência de Aminoácidos , Animais , Linhagem Celular , Chaperonina com TCP-1/isolamento & purificação , Expressão Gênica , Humanos , Dados de Sequência Molecular , Plasmídeos/genética , Dobramento de Proteína , Subunidades Proteicas/isolamento & purificação , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Vaccinia virus/genéticaRESUMO
Virus particles are used in vaccination, drug delivery, and material sciences. Here we devised a system where the RNA virus encephalomyocarditis virus (EMCV) is synthesized from DNA templates in vitro. When a plasmid or a PCR product harboring the full-length cDNA of EMCV in the T7 promoter/terminator unit was incubated in a HeLa cell extract supplemented with T7 RNA polymerase, EMCV was produced within 4 h at an efficiency of over 10-fold compared with the system programmed with the EMCV RNA. The EMCV RNA transcribed by the virally encoded RNA-dependent RNA polymerase was predominantly incorporated into the EMCV particle even in the presence of a larger amount of the EMCV RNA transcribed by T7 RNA polymerase from the plasmid.
Assuntos
Vírus da Encefalomiocardite/genética , RNA Viral/biossíntese , Proteínas Virais/biossíntese , Montagem de Vírus , Biotecnologia/métodos , Extratos Celulares , Sistema Livre de Células , Células HeLa , Humanos , Plasmídeos , Virologia/métodosRESUMO
Inhibition of glucosylceramide synthase (GCS) is a major therapeutic strategy for Gaucher's disease and has been suggested as a potential target for treating Parkinson's disease. Herein, we report the discovery of novel brain-penetrant GCS inhibitors. Assessment of the structure-activity relationship revealed a unique pharmacophore in this series. The lipophilic ortho-substituent of aromatic ring A and the appropriate directionality of aromatic ring B were key for potency. Optimization of the absorption, distribution, metabolism, elimination, toxicity (ADMETox) profile resulted in the discovery of T-036, a potent GCS inhibitor in vivo. Pharmacophore-based scaffold hopping was performed to mitigate safety concerns associated with T-036. The ring opening of T-036 resulted in another potent GCS inhibitor with a lower toxicological risk, T-690, which reduced glucosylceramide in a dose-dependent manner in the plasma and cortex of mice. Finally, we discuss the structural aspects of the compounds that impart a unique inhibition mode and lower the cardiovascular risk.
Assuntos
Doença de Gaucher , Glucosiltransferases , Animais , Encéfalo/metabolismo , Doença de Gaucher/tratamento farmacológico , Doença de Gaucher/metabolismo , Glucosilceramidas/metabolismo , Glucosilceramidas/uso terapêutico , Glucosiltransferases/metabolismo , Glucosiltransferases/uso terapêutico , CamundongosRESUMO
Fetuin-A is an important inhibitor of extraosseous calcification, but some of the studies that used ELISAs did not identify a significant relationship between serum fetuin-A levels and vascular calcification in patients with chronic kidney disease (CKD). Here, we used centrifugation to separate a fetuin-mineral complex (FMC) composed of fetuin-A, fibrinogen, fibronectin-1, and calcium from the serum of hemodialysis patients. In addition, we analyzed serum fetuin-A levels of 73 patients with diabetes and CKD (predialysis) after centrifugation. Fetuin-A concentrations were significantly lower in supernatants than in serum from patients at any stage of CKD, indicating systemic circulation of FMC in these patients. With greater severity of CKD, the contribution of FMC to total fetuin-A increased. Despite the absence of a correlation between serum fetuin-A and coronary artery calcification scores (CACS), supernatant fetuin-A negatively correlated with CACS and the extent to which centrifugation reduced fetuin-A (reduction ratio [RR]) positively correlated with CACS. In a longitudinal study of 12 hemodialysis patients with secondary hyperparathyroidism, parathyroidectomy and cinacalcet therapy each significantly reduced the RR without changing supernatant fetuin-A levels after 1 month, suggesting a reduction in FMC. Moreover, the magnitude of cinacalcet-induced reduction in parathyroid hormone correlated with the decrease in RR but not with changes in serum or supernatant fetuin-A. These data suggest that a quantitative measure of FMC, not supernatant or serum fetuin-A as measured in previous studies, reflects extraosseous calcification stress.
Assuntos
Proteínas Sanguíneas/metabolismo , Calcinose/metabolismo , Cálcio/metabolismo , Fibrinogênio/metabolismo , Fibronectinas/metabolismo , Nefropatias/metabolismo , Idoso , Biomarcadores/metabolismo , Estudos de Casos e Controles , Doença Crônica , Cinacalcete , Doença da Artéria Coronariana/metabolismo , Feminino , Humanos , Hiperparatireoidismo Secundário/tratamento farmacológico , Hiperparatireoidismo Secundário/metabolismo , Nefropatias/complicações , Nefropatias/terapia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Naftalenos/uso terapêutico , Diálise Renal , Índice de Gravidade de Doença , alfa-2-Glicoproteína-HSRESUMO
ABSTRACT: According to the implementing arrangement between the Japan Atomic Energy Agency (JAEA) and the Korea Atomic Energy Research Institute (KAERI) in the field of radiation protection and environmental radiation monitoring, a joint survey program was performed to assess ground deposition of radioactive cesium in areas surrounding the Fukushima Daiichi Nuclear Power Plants. The purpose of this joint survey was to evaluate the field applications of the developed survey systems and methodologies. Understanding the performance of each system within a cesium-deposited contaminated zone is important for ensuring an appropriate response following a nuclear accident. The results of the measured ambient dose rates determined using each survey method were compared. Two kinds of survey system were used in the mobile gamma-ray spectrometry, which were MARK-M1 (Monitoring of Ambient Radiation of KAERI-the 1st Multipurpose system) based on two LaBr3(Ce) detectors of KAERI and KURAMA-II (Kyoto University Radiation Mapping - II) system with one CsI(Tl) detector of JAEA. First, mobile gamma-ray spectrometry using a backpack survey platform was conducted to assess the distribution of dose rates around specific survey sites, which were expected to be slightly contaminated by radioactive cesium in Minamisoma and Tomioka. A carborne survey using two gamma-ray spectrometers loaded inside a vehicle was successfully conducted to compare the measured dose rates in routes from site to site and verify evaluation methods, including attenuation correction.
Assuntos
Poluentes Radioativos do Ar , Acidente Nuclear de Fukushima , Energia Nuclear , Monitoramento de Radiação , Cinza Radioativa , Academias e Institutos , Poluentes Radioativos do Ar/análise , Radioisótopos de Césio/análise , Humanos , Japão , Centrais Nucleares , Cinza Radioativa/análise , República da Coreia , Espectrometria gama , Inquéritos e QuestionáriosRESUMO
Hepatocellular carcinoma (HCC) is the most common form of liver cancer. This study aims to develop a new method to generate an HCC mouse model with a human tumor, and imitates the tumor microenvironment (TME) of clinical patients. Here, we have generated functional, three-dimensional sheet-like human HCC organoids in vitro, using luciferase-expressing Huh7 cells, human iPSC-derived endothelial cells (iPSC-EC), and human iPSC-derived mesenchymal cells (iPSC-MC). The HCC organoid, capped by ultra-purified alginate gel, was implanted into the disrupted liver using an ultrasonic homogenizer in the immune-deficient mouse, which improved the survival and engraftment rate. We successfully introduced different types of controllable TME into the model and studied the roles of TME in HCC tumor growth. The results showed the role of the iPSC-EC and iPSC-MC combination, especially the iPSC-MC, in promoting HCC growth. We also demonstrated that liver fibrosis could promote HCC tumor growth. However, it is not affected by non-alcoholic fatty liver disease. Furthermore, the implantation of HCC organoids to humanized mice demonstrated that the immune response is important in slowing down tumor growth at an early stage. In conclusion, we have created an HCC model that is useful for studying HCC development and developing new treatment options in the future.
RESUMO
Human cell-derived in vitro protein synthesis systems are useful for the production of recombinant proteins. Productivity can be increased by supplementation with GADD34, a protein that is difficult to express in and purify from E. coli. Deletion of the N-terminal 120 or 240 amino acids of GADD34 improves recovery of this protein from E. coli without compromising its ability to boost protein synthesis in an in vitro protein synthesis system. The use of N-terminally truncated GADD34 proteins in place of full-length GADD34 should improve the utility of human cell-based cell-free protein synthesis systems.
Assuntos
Antígenos de Diferenciação/genética , Antígenos de Diferenciação/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Biossíntese de Proteínas , Proteínas/metabolismo , Antígenos de Diferenciação/isolamento & purificação , Proteínas de Ciclo Celular/isolamento & purificação , Extratos Celulares , Escherichia coli/genética , Expressão Gênica , Humanos , Proteína Fosfatase 1 , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Deleção de SequênciaRESUMO
Radiation air dose rates near the Fukushima Daiichi Nuclear Power Plant (FDNPP) have been steadily decreasing over the past eight years since the release of radioactive elements in March 2011. Currently, the radiation monitoring program is expected to transition to long-term monitoring after most of the remediation activities are completed. The main long-term monitoring objectives are to (1) confirm the continuing reduction of contaminant and hazard levels, (2) provide assurance for the public, (3) accumulate the basic datasets for scientific knowledge and future preparation, and (4) detect changes or anomalies in contaminant mobility (if they occur), or any unexpected processes or events. In this work, we have developed a methodology for optimizing the monitoring locations of radiation air dose-rate monitoring. Our approach consists of three steps in order to determine monitoring locations in a systematic manner: (1) prioritizing the critical locations, such as schools or regulatory requirement locations, (2) diversifying locations that cover the key environmental controls that are known to influence contaminant mobility and distributions, and (3) capturing the heterogeneity of radiation air-dose rates across the domain. For the second step, we use a Gaussian mixture model to identify the representative locations among multiple environmental variables, such as elevation and land-cover types. For the third step, we use a Gaussian process model to capture and estimate the heterogeneity of air-dose rates across the domain. Employing an integrated dose-rate map derived from Bayesian geostatistical methods as a reference map, we distribute the monitoring locations in such a way as to capture the heterogeneity of the reference map. Our results have shown that this approach allows us to select monitoring locations in a systematic manner such that the heterogeneity of air dose rates is captured by the minimal number of monitoring locations.
Assuntos
Acidente Nuclear de Fukushima , Monitoramento de Radiação , Poluentes Radioativos do Ar , Teorema de Bayes , Radioisótopos de Césio , Japão , Centrais NuclearesRESUMO
Transplantation of liver organoids has been investigated as a treatment alternative to liver transplantation for chronic liver disease. Transportal approach can be considered as a method of delivering organoids to the liver. It is important to set the allowable organoid amount and verify translocation by intraportal transplantation. We first examined the transplantation tolerance and translocation of porcine fetal liver-derived allogeneic organoids using piglets. Fetal liver-derived organoids generated from the Kusabira Orange-transduced pig were transplanted to the 10-day-old piglet liver through the left branch of the portal vein. All recipients survived without any observable adverse events. In contrast, both local and main portal pressures increased transiently during transplantation. In necropsy samples, Kusabira Orange-positive donor cells were detected primarily in the target lobe of the liver and partly in other areas, including the lungs and brain. As we confirmed the transplantation allowance by porcine fetal liver-derived organoids, we performed intraportal transplantation of human-induced pluripotent stem cell (iPSC)-derived liver organoid, which we plan to use in clinical trials, and portal pressure and translocation were investigated. Human iPSC-derived liver organoids were transplanted into the same 10-day-old piglet. Portal hypertension and translocation of human iPSC-derived liver organoids to the lungs were observed in one of two transplanted animals. Translocation occurred in the piglet in which patent ductus venosus (PDV) was observed. Therefore, a 28-day-old piglet capable of surgically ligating PDV was used, and after the PDV was ligated, human iPSC-derived liver organoids with the amount of which is scheduled in clinical trials were transplanted. This procedure inhibited the translocation of human iPSC-derived liver organoids to extrahepatic sites without no portal hypertension. In conclusion, human iPSC-derived liver organoids can be safely transplanted through the portal vein. Ligation of the ductus venosus prior to transplantation was effective in inhibiting extrahepatic translocation in newborns and infants.
Assuntos
Células-Tronco Pluripotentes Induzidas/citologia , Organoides/citologia , Animais , Veia Porta/metabolismo , Transplante de Células-Tronco/métodos , SuínosRESUMO
In this multicentre double-blind randomized clinical trial, we investigated the effects of oral cholecalciferol supplementation on serum hepcidin and parameters related to anaemia and CKD-MBD among haemodialysis patients. Participants were assigned in a 2:2:1:1 ratio to either (1) thrice-weekly 3,000-IU cholecalciferol, (2) once-monthly cholecalciferol (equivalent to 9,000 IU/week), (3) thrice-weekly placebo, or (4) once-monthly placebo. We also examined the effect modifications by selected single nucleotide polymorphisms in vitamin D-related genes. Out of 96 participants, 94 were available at Month 3, and 88 completed the 6-month study. After adjustment for baseline values, serum hepcidin levels were higher at Day 3 in the combined cholecalciferol (vs. placebo) group, but were lower at Month 6 with increased erythropoietin resistance. Cholecalciferol increased serum 1,25(OH)2D levels, resulting in a greater proportion of patients who reduced the dose of active vitamin D at Month 6 (31% vs. 10% in the placebo group). Cholecalciferol also suppressed intact PTH only among patients with severe vitamin D deficiency. In conclusion, cholecalciferol supplementation increases serum hepcidin-25 levels in the short term and may increase erythropoietin resistance in the long term among haemodialysis patients. Both thrice-weekly and once-monthly supplementation effectively increases serum 1,25(OH)2D levels, and hence, reduces active vitamin D drugs.Clinical Trial Registry: This study was registered at ClinicalTrials.gov and University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) as NCT02214563 (registration date: 12/08/2014) and UMIN000011786 (registration date: 15/08/2014), respectively (please refer to the links below). ClinicalTrials.gov: https://clinicaltrials.gov/ct2/show/record/NCT02214563 . UMIN-CTR: https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&type=summary&recptno=R000017152&language=E .
Assuntos
Anemia/prevenção & controle , Colecalciferol/uso terapêutico , Distúrbio Mineral e Ósseo na Doença Renal Crônica/prevenção & controle , Hepcidinas/sangue , Diálise Renal/efeitos adversos , Idoso , Anemia/terapia , Colecalciferol/administração & dosagem , Distúrbio Mineral e Ósseo na Doença Renal Crônica/terapia , Método Duplo-Cego , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , Diálise Renal/métodos , Vitamina D/metabolismoRESUMO
The serum glycoprotein fetuin-A is an important inhibitor of extra-osseous calcification, but correlations between serum fetuin-A levels and the extent of vascular calcification are controversial. In this study, we used a rat model of adenine-induced renal failure with secondary hyperparathyroidism that exhibits all characteristic features of patients with chronic kidney disease. These rats had medial vascular calcification along with reduced levels of both serum and hepatic fetuin-A. Treatment with an inhibitor of ectopic calcification, alendronate, decreased bone turnover and eliminated completely the vascular calcification in this rat model, but there was no change in the levels of hepatic and serum fetuin-A. Centrifugation of the serum of untreated rats with renal failure gave a small precipitate composed of fetuin-A, calcium, magnesium, and phosphate; this complex, absent from normal rat serum, was not found in the serum of alendronate-treated rats with renal failure. Rat serum contained three types of phosphorylated fetuin-A, as well as unphosphorylated forms, but only the fully phosphorylated fetuin-A was present in the mineral complex. The amount of this complex reflected the risk of mineral precipitation. Our results suggest that the measurement of serum fetuin-mineral complex rather than fetuin-A alone might provide a better indication of extra-osseous calcification propensity.
Assuntos
Calcinose/etiologia , Minerais/metabolismo , Insuficiência Renal/sangue , alfa-Fetoproteínas/metabolismo , Adenina/efeitos adversos , Alendronato/farmacologia , Animais , Calcinose/tratamento farmacológico , Precipitação Química , Fígado/metabolismo , Masculino , Minerais/sangue , Fosforilação , Ratos , Ratos Wistar , Insuficiência Renal/induzido quimicamente , Insuficiência Renal/metabolismoRESUMO
In this study, we quantify the temporal changes of air dose rates in the regional scale around the Fukushima Dai-ichi Nuclear Power Plant in Japan, and predict the spatial distribution of air dose rates in the future. We first apply the Bayesian geostatistical method developed by Wainwright et al. (2017) to integrate multiscale datasets including ground-based walk and car surveys, and airborne surveys, all of which have different scales, resolutions, spatial coverage, and accuracy. This method is based on geostatistics to represent spatial heterogeneous structures, and also on Bayesian hierarchical models to integrate multiscale, multi-type datasets in a consistent manner. We apply this method to the datasets from three years: 2014 to 2016. The temporal changes among the three integrated maps enables us to characterize the spatiotemporal dynamics of radiation air dose rates. The data-driven ecological decay model is then coupled with the integrated map to predict future dose rates. Results show that the air dose rates are decreasing consistently across the region. While slower in the forested region, the decrease is particularly significant in the town area. The decontamination has contributed to significant reduction of air dose rates. By 2026, the air dose rates will continue to decrease, and the area above 3.8 µSv/h will be almost fully contained within the non-residential forested zone.