RESUMO
Contact engineering on monolayer layer (ML) semiconducting transition metal dichalcogenides (TMDs) is considered the most challenging problem toward using these materials as a transistor channel in future advanced technology nodes. The typically observed strong Fermi-level pinning induced in part by the reaction of the source/drain contact metal and the ML TMD frequently results in a large Schottky barrier height, which limits the electrical performance of ML TMD field-effect transistors (FETs). However, at a microscopic level, little is known about how interface defects or reaction sites impact the electrical performance of ML TMD FETs. In this work, we have performed statistically meaningful electrical measurements on at least 120 FETs combined with careful surface analysis to unveil contact resistance dependence on interface chemistry. In particular, we achieved a low contact resistance for ML MoS2 FETs with ultrahigh-vacuum (UHV, 3 × 10-11 mbar) deposited Ni contacts, â¼500 Ω·µm, which is 5 times lower than the contact resistance achieved when deposited under high-vacuum (HV, 3 × 10-6 mbar) conditions. These electrical results strongly correlate with our surface analysis observations. X-ray photoelectron spectroscopy (XPS) revealed significant bonding species between Ni and MoS2 under UHV conditions compared to that under HV. We also studied the Bi/MoS2 interface under UHV and HV deposition conditions. Different from the case of Ni, we do not observe a difference in contact resistance or interface chemistry between contacts deposited under UHV and HV. Finally, this article also explores the thermal stability and reliability of the two contact metals employed here.
RESUMO
Herein, we report the synthesis of a flexible bis-cyclopentadienyl ligand L (the doubly deprotonated form of H2L (1,3-bis(2,4-di-tert-butylcyclopentadienyldimethylsilyl)benzene)), demonstrating its ability to stabilize a series of di-iron hydrido complexes. Notably, this ligand facilitates the isolation of an unprecedented anionic cyclopentadienyl ligand-supported di-iron trihydride complex, LFe2(µ-H)3Li(THF) (2), functioning as a synthon for the [Fe2(µ-H)3]- core and providing access to heterobimetallic complexes 4-6 with coinage metals.
RESUMO
Introduction: The effectiveness of an elemental diet (ED) for preventing adverse events (AEs) during chemotherapy for patients with esophageal cancer (EC) remains unclear. The aim of this meta-analysis was to comprehensively assess the efficacy of ED for preventing AE in EC patients during chemotherapy. Medline (via PubMed), Embase, the Cochrane Library, and Web of Science were searched to retrieve prospective and randomized studies published before April 12, 2023. The odds ratio (OR) of each AE was calculated using Review Manger 5.4.1. The risk of bias was assessed, and a random effect model-based meta-analysis was used to analyze the available data. Four prospective and randomized studies involving 237 patients were identified after a systematic search. Regarding gastrointestinal toxicities, the findings indicated a trend toward a decrease in the risk of mucositis (OM) (OR = 0.54, 95 % CI: 0.25-1.14), constipation (OR = 0.87, 95 % CI: 0.49-1.53), and anorexia (OR = 0.99, 95 % CI: 0.32-3.05), as well as an increasing trend in the risk of diarrhea (OR = 1.48, 95 % CI: 0.79-2.79), among patients treated with ED. However, none of these reached statistical significance. For hematological toxicities, the risk of all-grade neutropenia (OR = 0.28, 95 % CI: 0.14-0.57), grade ≥ 2 leucopenia (OR = 0.43, 95 % CI: 0.22-0.84), grade ≥ 2 neutropenia (OR = 0.34, 95 % CI: 0.17-0.67), and grade ≥ 3 neutropenia (OR = 0.28, 95 % CI: 0.12-0.63) was significantly decreased. There is no firm evidence confirming the preventive effect of an ED against OM or diarrhea. However, an ED may potentially be helpful in preventing neutropenia and leucopenia.
Introducción: La efectividad de una dieta elemental (DE) para prevenir eventos adversos (EA) durante la quimioterapia en pacientes con cáncer de esófago (CE) sigue sin estar clara. Este metaanálisis evalúa la eficacia de DE para prevenir EA en pacientes con CE durante quimioterapia. Se realizaron búsquedas en Medline (con PubMed), Embase, Biblioteca Cochrane y Web of Science para recuperar estudios prospectivos y aleatorios publicados antes del 12/04/2023. La razón de probabilidad (RP) de cada EA se calculó usando Review Manger 5.4.1. Se evaluó el riesgo de sesgo y se utilizó un metaanálisis basado en modelo de efectos aleatorios para analizar los datos disponibles. Después de una búsqueda sistemática, se identificaron cuatro estudios prospectivos y aleatorios con 237 pacientes. En cuanto a las toxicidades gastrointestinales, los hallazgos indicaron una tendencia hacia una disminución en el riesgo de mucositis (OM) (OR = 0,54, IC 95 %: 0,25-1,14), estreñimiento (OR = 0,87, IC 95 %: 0,49-1,53) y anorexia (OR = 0,99, IC 95 %: 0,32-3,05) y una tendencia creciente en el riesgo de diarrea (OR = 1,48, IC 95 %: 0,79-2,79) entre los pacientes tratados con DE. Sin embargo, no hubo muestras estadísticas significativas. Para toxicidades hematológicas, el riesgo de neutropenia de todos los grados (RP = 0,28; IC del 95 %: 0,14-0,57), leucopenia grado ≥ 2 (RP = 0,43; IC del 95 %: 0,22-0,84), neutropenia grado ≥ 2 (RP = 0,34; IC del 95 %: 0,17-0,67) y neutropenia grado ≥ 3 (RP = 0,28; IC del 95 %: 0,12-0,63) disminuyó significativamente. Ninguna evidencia firme confirmó el efecto preventivo de DE frente a OM o la diarrea. Una DE sería útil previniendo neutropenia y leucopenia.
Assuntos
Antineoplásicos , Neoplasias Esofágicas , Alimentos Formulados , Humanos , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
SIRT6, a key member of the sirtuin family, plays a pivotal role in regulating a number of vital biological processes, including energy metabolism, oxidative stress, and immune system modulation. Nevertheless, the function of SIRT6 in bony fish, particularly in the context of antiviral immune response, remains largely unexplored. In this study, a sirt6 was cloned and characterized in a commercial fish, the Chinese perch (Siniperca chuatsi). The SIRT6 possesses conserved SIR2 domain with catalytic core region when compared with other vertebrates. Tissue distribution analysis indicated that sirt6 was expressed in all detected tissues, and the sirt6 was significantly induced following infection of infectious haemorrhagic syndrome virus (IHSV). The overexpression of SIRT6 resulted in significant upregulation of interferon-stimulated genes (ISGs), such as viperin, mx, isg15, irf3 and ifp35, and inhibited viral replication. It was further found that SIRT6 was located in nucleus and could enhance the expression of ISGs induced by type I and II IFNs. These findings may provide new information in relation with the function of SIRT6 in vertebrates, and with viral prevention strategy development in aquaculture.
Assuntos
Sequência de Aminoácidos , Doenças dos Peixes , Proteínas de Peixes , Regulação da Expressão Gênica , Imunidade Inata , Percas , Filogenia , Infecções por Rhabdoviridae , Sirtuínas , Animais , Sirtuínas/genética , Sirtuínas/imunologia , Sirtuínas/metabolismo , Doenças dos Peixes/imunologia , Doenças dos Peixes/virologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Proteínas de Peixes/química , Imunidade Inata/genética , Infecções por Rhabdoviridae/imunologia , Infecções por Rhabdoviridae/veterinária , Regulação da Expressão Gênica/imunologia , Percas/imunologia , Alinhamento de Sequência/veterinária , Perfilação da Expressão Gênica/veterináriaRESUMO
NOD1 and NOD2 as two representative members of nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family play important roles in antimicrobial immunity. However, transcription mechanism of nod1 and nod2 and their signal circle are less understood in teleost fish. In this study, with the cloning of card9 and ripk2 in Chinese perch, the interaction between NOD1, NOD2, and CARD9 and RIPK2 were revealed through coimmunoprecipitation and immunofluorescence assays. The overexpression of NOD1, NOD2, RIPK2 and CARD9 induced significantly the promoter activity of NF-κB, IFNh and IFNc. Furthermore, it was found that nod1 and nod2 were induced by poly(I:C), type I IFNs, RLR and even NOD1/NOD2 themselves through the ISRE site of their proximal promoters. It is thus indicated that nod1 and nod2 can be classified also as ISGs due to the presence of ISRE in their proximal promoter, and their expression can be mechanistically controlled through PRR pathway as well as through IFN signaling in antiviral immune response.
Assuntos
Proteínas de Peixes , Proteína Adaptadora de Sinalização NOD1 , Proteína Adaptadora de Sinalização NOD2 , Proteína Serina-Treonina Quinase 2 de Interação com Receptor , Transdução de Sinais , Animais , Proteína Adaptadora de Sinalização NOD1/genética , Proteína Adaptadora de Sinalização NOD1/metabolismo , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/metabolismo , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/genética , Proteína Adaptadora de Sinalização NOD2/genética , Proteína Adaptadora de Sinalização NOD2/metabolismo , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Proteínas de Peixes/imunologia , Percas/genética , Percas/imunologia , Percas/metabolismo , Interferons/metabolismo , Interferons/genética , Regiões Promotoras Genéticas , Transcrição Gênica , Imunidade Inata/genética , Ligação ProteicaRESUMO
Type IV interferon (IFN) has been shown to be a cytokine with antiviral activity in fish and amphibian. But, it has not been cloned and characterized functionally in avian species. In this study, type IV IFN, IFN-υ, and its 2 possible receptors, IFN-υR1 and IL10RB, were identified from an avian species, the mallard (Anas platyrhynchos). Mallard IFN-υ has a 531 bp open reading frame (ORF), encoding 176 amino acids (aa), and has highly conserved features as reported in different species, with an N-terminal signal peptide and a predicted multi-helix structure. The IFN-υR1 and IL10RB contain 528 and 343 aa, respectively, with IFN-υR1 protein containing JAK1 and STAT binding sites, and IL10RB containing TYK2 binding site. These 2 receptor subunits also possess 3 domains, the N-terminal extracellular domain, the transmembrane domain, and the C-terminal intracellular domain. Expression analysis indicated that IFN-υ, IFN-υR1 and IL10RB were widely expressed in examined organs/tissues, with the highest level observed in pancreas, blood, and kidney, respectively. The expression of IFN-υ, IFN-υR1 and IL10RB in liver, spleen or kidney was significantly upregulated after stimulation with polyI:C. Furthermore, recombinant IFN-υ protein induced the expression of ISGs, and the receptor of IFN-υ was verified as IFN-υR1 and IL10RB using a chimeric receptor approach in HEK293 cells. Taken together, these results indicate that IFN-υ is involved in the host innate immune response in mallard.
Assuntos
Proteínas Aviárias , Patos , Subunidade beta de Receptor de Interleucina-10 , Animais , Patos/genética , Subunidade beta de Receptor de Interleucina-10/genética , Subunidade beta de Receptor de Interleucina-10/química , Subunidade beta de Receptor de Interleucina-10/metabolismo , Proteínas Aviárias/genética , Proteínas Aviárias/química , Proteínas Aviárias/metabolismo , Sequência de Aminoácidos , Filogenia , Receptores de Interferon/genética , Receptores de Interferon/metabolismo , Receptores de Interferon/química , Alinhamento de Sequência/veterinária , Imunidade Inata , Interferons/genética , Interferons/metabolismo , Perfilação da Expressão Gênica/veterináriaRESUMO
Durability is one of the technical bottlenecks restricting fuel cell electric vehicle development. As a result, significant time and resources have been invested in research related to this area worldwide. Current durability research mainly focuses on the single cell and stack levels, which is quite different from the usage scenarios of actual vehicles. There is almost no research on developing durability test cycles on the fuel cell system level. This paper proposes a universal model for developing a durability test cycle for fuel cell system based on the China automotive test cycle. Large-scale comparison tests of the fuel cell systems are conducted. After 1000 h test, the output performance degradation of three mass-produced fuel cell system is 14.49%, 9.59%, and 4.21%, respectively. The test results show that the durability test cycle proposed in this paper can effectively accelerate the durability test of the fuel cell system and evaluate the durability performance of the fuel cell system. Moreover, the methodology proposed in this paper could be used in any other test cycles such as NEDC (New European Driving Cycle), WLTC (Worldwide Harmonized Light Vehicles Test Procedure), etc. And it has comprehensive application value and are significant for reducing the cost of durability testing of fuel cell systems and promoting the industrialization of fuel cell electric vehicles.
RESUMO
Moth insects rely on sex pheromones for long distance attraction and searching for sex partners. The biosynthesis of moth sex pheromones involves the catalytic action of multiple enzymes, with desaturases playing a crucial role in the process of carbon chain desaturation. However, the specific desaturases involved in sex pheromone biosynthesis in fall armyworm (FAW), Spodoptera frugiperda, have not been clarified. In this study, a Δ11 desaturase (SfruDES1) gene in FAW was knocked out using the CRISPR/Cas9 genome editing system. A homozygous mutant of SfruDES1 was obtained through genetic crosses. The gas chromatography-mass spectrometry (GC-MS) analysis results showed that the three main sex pheromone components (Z7-12:Ac, Z9-14:Ac, and Z11-16:Ac) and the three minor components (Z9-14:Ald, E11-14:Ac and Z11-14:Ac) of FAW were not detected in homozygous mutant females compared to the wild type. Furthermore, behavioral assay demonstrated that the loss of SfruDES1 resulted in a significant reduction in the attractiveness of females to males, along with disruptions in mating behavior and oviposition. Additionally, in a heterologous expression system, recombinant SfruDES1 could introduce a cis double bond at the Δ11 position in palmitic acid, which resulted in the changes in components of the synthesized products. These findings suggest desaturase plays a key role in the biosynthesis of sex pheromones, and knockout of the SfruDES1 disrupts sex pheromone biosynthesis and mating behavior in FAW. The SfruDES1 could serve as tool to develop a control method for S. frugiperda.
Assuntos
Mariposas , Atrativos Sexuais , Animais , Feminino , Masculino , Spodoptera/genética , Spodoptera/metabolismo , Atrativos Sexuais/metabolismo , Oviposição , Mariposas/genética , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/química , Ácidos Graxos Dessaturases/metabolismoRESUMO
Uranium-containing silica gel (UCSG) is a secondary waste generated during the advanced treatment of nuclear wastewater. In order to reduce the growing storage pressure for UCSG, from the perspective of building a borosilicate glass network, UCSG was used to replace SiO2 in the glass-cured formula to directly achieve the immobilization of UCSG. SEM-EDS results showed that uranium was uniformly distributed in the matrix, and the maximum solid solubility of UCSG (two components: silica gel and uranyl ions) in the formula was as high as 55 wt %. At the same time, TG-MS proved that silica gel lost OH groups (down about 4.61 wt %) and formed Si-O-Si bond by condensation. FT-IR and XPS proved a change in the number of Si-O-Si bond, and new Si-O-B and Si-O-Al bond appeared on the spectrum. This was evidence that silica gel could self-involved participate in the construction of glass networks. EPR analysis obtained the changes in the coordination environment of U atom, the U atom decreased spin electrons number in the glass than in uranyl crystals. The glass also has good physical properties (hardness: 6.51 ± 0.23 GPa; density: 2.3977 ± 0.0056 g/cm3) and chemical durability (normalized leaching rate: LRU = 2.34 × 10-4 ± 2.05 × 10-6 g·m2·days-1 after 42 days), this research provided tactics for simple treatment of uranium-containing silica gel in one step.
RESUMO
Type II interferons (IFNs) are a key class of molecules regulating innate and adaptive immunity in vertebrates. In the present study, two members of the type II IFNs, IFN-γ and IFNγ-rel, were identified in the blunt snout bream (Megalobrama amblycephala). The open reading frame (ORF) of IFN-γ and IFNγ-rel was found to have 564 bp and 492 bp, encoding 187 and 163 amino acids, with the first 26 and 24 amino acids being the signal peptide, respectively. IFN-γ and IFNγ-rel genes showed a high degree of similarity to their zebrafish homologues, being 76.9 % and 58.9 %, respectively. In the phylogenetic tree, IFN-γ and IFNγ-rel were clustered with homologous genes in cyprinids. In blunt snout bream, IFN-γ and IFNγ-rel were constitutively expressed in trunk kidney, head kidney, spleen, liver, heart, muscle, gill, intestine and brain and were significantly up-regulated by poly (I:C) induction in head kidney, spleen, liver, gill and intestine. Using recombinant proteins of IFN-γ and IFNγ-rel, the surface plasmon resonance (SPR) results showed that IFN-γ was bound to CRFB6, CRFB13 and CRFB17, but mainly to CRFB6 and CRFB13, whereas IFN-γrel bound mainly to CRFB17 and had no affinity with CRFB6. These results contribute to a better understanding on type II IFNs and their receptor usage in teleost fish.
Assuntos
Cyprinidae , Peixe-Zebra , Animais , Peixe-Zebra/metabolismo , Filogenia , Interferon gama/genética , Interferon gama/metabolismo , Sequência de Aminoácidos , Proteínas de Peixes/química , Proteínas Recombinantes/genética , Aminoácidos/genéticaRESUMO
Crystalline-amorphous hybrid materials (CA-HMs) possess the merits of both pure crystalline and amorphous phases. Abundant dangling bonds, unsaturated coordination atoms, and isotropic structural features in the amorphous phase, as well as relatively high electronic conductivity and thermodynamic structural stability of the crystalline phase simultaneously take effect in CA-HMs. Furthermore, the atomic and bandgap mismatch at the CA-HM interface can introduce more defects as extra active sites, reservoirs for promoted catalytic and electrochemical performance, and induce built-in electric field for facile charge carrier transport. Motivated by these intriguing features, herein, we provide a comprehensive overview of CA-HMs on various aspects-from synthetic methods to multiple applications. Typical characteristics of CA-HMs are discussed at the beginning, followed by representative synthetic strategies of CA-HMs, including hydrothermal/solvothermal methods, deposition techniques, thermal adjustment, and templating methods. Diverse applications of CA-HMs, such as electrocatalysis, batteries, supercapacitors, mechanics, optoelectronics, and thermoelectrics along with underlying structure-property mechanisms are carefully elucidated. Finally, challenges and perspectives of CA-HMs are proposed with an aim to provide insights into the future development of CA-HMs.
RESUMO
Graphite (Gr) has been considered as the most promising anode material for potassium-ion batteries (PIBs) commercialization due to its high theoretical specific capacity and low cost. However, Gr-based PIBs remain unfeasible at low temperature (LT), suffering from either poor kinetics based on conventional carbonate electrolytes or K+ -solvent co-intercalation issue based on typical ether electrolytes. Herein, a high-performance Gr-based LT rechargeable PIB is realized for the first time by electrolyte chemistry. Applying unidentate-ether-based molecule as the solvent dramatically weakens the K+ -solvent interactions and lowers corresponding K+ de-solvation kinetic barrier. Meanwhile, introduction of steric hindrance suppresses co-intercalation of K+ -solvent into Gr, greatly elevating operating voltage and cyclability of the full battery. Consequently, the as-prepared Gr||prepotassiated 3,4,9,10-perylene-tetracarboxylicacid-dianhydride (KPTCDA) full PIB can reversibly charge/discharge between -30 and 45 °C with a considerable energy density up to 197â Wh kgcathode -1 at -20 °C, hopefully facilitating the development of LT PIBs.
RESUMO
Two-dimensional (2D) materials hold great promise for future complementary metal-oxide semiconductor (CMOS) technology. However, the lack of effective methods to tune the Schottky barrier poses a challenge in constructing high-performance complementary circuits from the same material. Here, we reveal that the polarity of pristine MoTe2 field-effect transistors (FETs) with minimized air exposure is n-type, irrespective of the metal contact type. The fabricated n-FETs with palladium contact can reach electron currents up to 275 µA/µm at VDS = 2 V. For p-FETs, we introduce a novel nitric oxide doping strategy, allowing a controlled transition of MoTe2 FETs from n-type to unipolar p-type. By doping only in the contact region, we demonstrate hole currents up to 170 µA/µm at VDS= -2 V with preserved Ion/Ioff ratios of 105. Finally, we present a complementary inverter circuit comprising the high-performance n- and p-type FETs based on MoTe2, promoting the application of 2D materials in future electronic systems.
RESUMO
Vascular stenosis is a late radiation complication that develops in long-term survivors of nasopharyngeal carcinoma. Vertebral arteries (VAs) are major vessels responsible for posterior circulation. In this study, we evaluated the feasibility of VA-sparing volumetric modulated arc therapy (VMAT) techniques. A total of 20 patients with nasopharyngeal carcinoma treated by a TrueBeam linear accelerator were enrolled in this study. The original VMAT plan was designed without the contouring of VAs as organs at risk (OARs). The same image set of the original VMAT plan was used to contour the VAs for each patient. A new VA-sparing VMAT plan was developed by avoiding VAs as OARs. Finally, a paired t-test was used to compare the dosimetric differences. The VA-sparing VMAT plan had similar target coverage and dose to those of other OARs. The VA-sparing plan yielded a significantly low VA dose from 53 to 40 Gy, with V35Gy changing from 97% to 56%, V50Gy changing from 67% to 35%, and V63Gy changing from 15% to approximately 7%-10% (p < 0.001 for all comparisons). VAs should be correctly identified as OARs. Photon VMAT with VA sparing can help substantially decrease the VA dose.
Assuntos
Carcinoma , Neoplasias Nasofaríngeas , Radioterapia de Intensidade Modulada , Humanos , Carcinoma Nasofaríngeo/radioterapia , Carcinoma/radioterapia , Artéria Vertebral/patologia , Radioterapia de Intensidade Modulada/métodos , Neoplasias Nasofaríngeas/radioterapia , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Órgãos em RiscoRESUMO
Drought is a destructive natural disaster in the Western Sichuan Plateau. Understanding its spatiotemporal variations has important practical significance for drought prevention, ensuring agricultural production safety, and maintaining ecosystem health in the region. Based on the daily meteorological data from 48 meteorological stations in the Western Sichuan Plateau from 1980 to 2020, we used the Penman-Monteith model to calculate potential evapotranspiration and standardized precipitation evapotranspiration index (SPEI). The temporal and spatial variations of drought in the Western Sichuan Plateau were analyzed using linear trend analysis and drought characteristics analysis methods. The results showed that the annual and spring SPEI of the Western Sichuan Plateau showed a weak wetting trend from 1980 to 2020, while summer, autumn, and winter showed a drought trend. The southwest mountains and northeast grasslands in the study region were prone to drought. The range of interannual drought impact in the study area was weakly increasing, with a decreasing trend in spring and an increasing trend in summer, autumn, and winter. The overall drought frequency in the whole region was relatively high. The areas drought of low-frequency were mainly located in parts of west and northeast of the Western Sichuan Plateau, while the rest were high frequency areas.
Assuntos
Secas , Ecossistema , Agricultura , Meteorologia , Estações do AnoRESUMO
We report the first NMR and X-ray diffraction (XRD) structures of an unusual 13/11-helix (alternating i, i+1 {NH-O=C} and i, i+3 {C=O-H-N} H-bonds) formed by a heteromeric 1 : 1 sequence of α- and δ-amino acids, and demonstrate the application of this framework towards catalysis. Whilst intramolecular hydrogen bonds (IMHBs) are the clear driver of helix formation in this system, we also observe an apolar interaction between the ethyl residue of one δ-amino acid and the cyclohexyl group of the next δ-residue in the sequence that seems to stabilize one type of helix over another. To the best of our knowledge this type of additional stabilization leading to a specific helical preference has not been observed before. Critically, the helix type realized places the α-residue functionalities in positions proximal enough to engage in bifunctional catalysis as demonstrated in the application of our system as a minimalist aldolase mimic.
Assuntos
Frutose-Bifosfato Aldolase , Peptídeos , Modelos Moleculares , Peptídeos/química , Aminoácidos/química , Aldeído Liases , Ligação de HidrogênioRESUMO
The class II cytokine receptor family members are receptors of class 2 helical cytokines in mammals, and are named cytokine receptor family B (CRFB) in fish. In zebrafish, sixteen members, including CRFB1, CRFB2 and CRFB4-17 were reported. With the availability of genome sequence, a total of nineteen CRFBs was identified in the blunt snout bream (Megalobrama amblycephala), including CRFB1, CRFB2, CRFB4-17 with the presence of three CRFB9 isoforms, and two CRFB14 isoforms. These CRFB molecules contain well conserved features, such as fibronectin type III (FNIII) domain, transmembrane and intracellular domains as other class II cytokine receptors, and are phylogenetically grouped into thirteen clades with their homologues from other species of fish. The CRFB genes were constitutively expressed in organs/tissues examined in the fish. The finding of more CRFB members in the bream may provide clues to understand possible receptor-ligand interaction and their diversity from an evolutionary point of view.
Assuntos
Cyprinidae , Peixe-Zebra , Animais , Cyprinidae/genética , Proteínas de Peixes/genética , Isoformas de Proteínas , Receptores de Citocinas , Peixe-Zebra/genéticaRESUMO
The type IV IFN (IFN-υ) is reported in vertebrates from fish to primary mammals with IFN-υR1 and IL-10R2 as receptor subunits. In this study, the proximal promoter of IFN-υ was identified in the amphibian model, Xenopus laevis, with functional IFN-sensitive responsive element and NF-κB sites, which can be transcriptionally activated by transcription factors, such as IFN regulatory factor (IRF)1, IRF3, IRF7, and p65. It was further found that IFN-υ signals through the classical IFN-stimulated gene (ISG) factor 3 (ISGF3) to induce the expression of ISGs. It seems likely that the promoter elements of the IFN-υ gene in amphibians is similar to type III IFN genes, and that the mechanism involved in IFN-υ induction is very much similar to type I and III IFNs. Using recombinant IFN-υ protein and the X. laevis A6 cell line, >400 ISGs were identified in the transcriptome, including ISGs homologous to humans. However, as many as 268 genes were unrelated to human or zebrafish ISGs, and some of these ISGs were expanded families such as the amphibian novel TRIM protein (AMNTR) family. AMNTR50, a member in the family, was found to be induced by type I, III, and IV IFNs through IFN-sensitive responsive element sites of the proximal promoter, and this molecule has a negative role in regulating the expression of type I, III, and IV IFNs. It is considered that the current study contributes to the understanding of transcription, signaling, and functional aspects of type IV IFN at least in amphibians.
Assuntos
Interferon Tipo I , Interferons , Animais , Humanos , Xenopus laevis , Interferons/genética , Interferons/metabolismo , Peixe-Zebra/metabolismo , Regulação da Expressão Gênica , Transdução de Sinais , Interferon Tipo I/metabolismo , Mamíferos/metabolismoRESUMO
Polymeric immunoglobulin receptor (pIgR) can bind and transport immunoglobulins (Igs), thus playing a role in mucosal immunity. In this study, pIgR gene was cloned in mandarin fish, Siniperca chuatsi, with the open reading frame (ORF) of 1011 bp, encoding 336 amino acids. The pIgR protein consists of a signal peptide, an extracellular domain, a transmembrane domain and an intracellular region, with the presence of two Ig-like domains (ILDs) in the extracellular domain, as reported in other species of fish. The pIgR gene was expressed in all organs/tissues of healthy mandarin fish, with higher level observed in liver and spleen. Following the immersion infection of Flavobacterium columnare, pIgR transcripts were detected in immune related, especially mucosal tissues, with significantly increased transcription during the first two days of infection. Through transfection of plasmids expressing pIgR, IgT and IgM, pIgR was found to be interacted with IgT and IgM as revealed by co-immunoprecipitation and immunofluorescence.
Assuntos
Doenças dos Peixes , Perciformes , Receptores de Imunoglobulina Polimérica , Animais , Sequência de Aminoácidos , Alinhamento de Sequência , Receptores de Imunoglobulina Polimérica/genética , Peixes , Clonagem Molecular , Imunoglobulina M/genética , Proteínas de PeixesRESUMO
IFN-stimulated genes (ISGs) can act as effector molecules against viral infection and can also regulate pathogenic infection and host immune response. N-Myc and STAT interactor (Nmi) is reported as an ISG in mammals and in fish. In this study, the expression of Nmi was found to be induced significantly by the infection of Siniperca chuatsi rhabdovirus (SCRV), and the induced expression of type I IFNs after SCRV infection was reduced following Nmi overexpression. It is observed that Nmi can interact with IRF3 and IRF7 and promote the autophagy-mediated degradation of these two transcription factors. Furthermore, Nmi was found to be interactive with IFP35 through the CC region to inhibit IFP35 protein degradation, thereby enhancing the negative role in type I IFN expression after viral infection. In turn, IFP35 is also capable of protecting Nmi protein from degradation through its N-terminal domain. It is considered that Nmi and IFP35 in fish can also interact with each other in regulating negatively the expression of type I IFNs, but thus in enhancing the replication of SCRV.