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Avian influenza viruses crossing the host barrier to infect humans have caused great panic in human society and seriously threatened public health. Herein, we revealed that knockdown of SRSF7 significantly down-regulated influenza virus titers and viral protein expression. We further observed for the first time that human SRSF7, but not avian SRSF7, significantly inhibited polymerase activity (PB2627E). Molecular mapping demonstrated that amino acids 206 to 228 of human SRSF7 play a decisive role in regulating the polymerase activity, which contains the amino acid motif absent in avian SRSF7. Importantly, our results illustrated that the PB2627K-encoding influenza virus induces SRSF7 protein degradation more strongly via the lysosome pathway and not via the proteasome pathway. Functional enrichment analysis of SRSF7-related KEGG pathways indicated that SRSF7 is closely related to cell growth and death. Lastly, our results showed that knocking down SRSF7 interferes with normal polymerase activity. Taken together, our results advance our understanding of interspecies transmission and our findings point out new targets for the development of drugs preventing or treating influenza virus infection.
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Poxviruses gained international attention due to the sharp rise in monkeypox cases in recent years, highlighting the urgent need for the development of a secure and reliable vaccine. This study involved the development of an innovative combined subunit vaccine (CSV) targeting poxviruses, with lumpy skin disease virus (LSDV) serving as the model virus. To this end, the potential sites for poxvirus vaccines were fully evaluated to develop and purify four recombinant proteins. These proteins were then successfully delivered to the dermis in a mouse model by utilizing dissolvable microneedle patches (DMPs). This approach simplified the vaccination procedure and significantly mitigated the associated risk. CSV-loaded DMPs contained four recombinant proteins and a novel adjuvant, CpG, which allowed DMPs to elicit the same intensity of humoral and cellular immunity as subcutaneous injection. Following immunization with SC and DMP, the mice exhibited notable levels of neutralizing antibodies, albeit at a low concentration. It is noteworthy that the CSV loaded into DMPs remained stable for at least 4 months at room temperature, effectively addressing the storage and transportation challenges. Based on the study findings, CSV-loaded DMPs are expected to be utilized worldwide as an innovative technique for poxvirus inoculation, especially in underdeveloped regions. This novel strategy is crucial for the development of future poxvirus vaccines.
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Anticuerpos Neutralizantes , Anticuerpos Antivirales , Infecciones por Poxviridae , Poxviridae , Vacunas de Subunidad , Animales , Vacunas de Subunidad/inmunología , Vacunas de Subunidad/administración & dosificación , Ratones , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Infecciones por Poxviridae/prevención & control , Infecciones por Poxviridae/inmunología , Femenino , Poxviridae/inmunología , Vacunas Virales/inmunología , Vacunas Virales/administración & dosificación , Ratones Endogámicos BALB C , Virus de la Dermatosis Nodular Contagiosa/inmunología , Vacunación , Inmunidad Celular , Inmunidad Humoral , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/administración & dosificación , Adyuvantes de Vacunas/administración & dosificación , Adyuvantes Inmunológicos/administración & dosificaciónRESUMEN
Rotavirus is a major causative agent of diarrhoea in children, infants, and young animals around the world. The associated zoonotic risk necessitates the serious consideration of the complete genetic information of rotavirus. A segmented genome makes rotavirus prone to rearrangement and the formation of a new viral strain. Monitoring the molecular epidemiology of rotavirus is essential for its prevention and control. The quantitative RT-PCR targeting the NSP5 gene was used to detect rotavirus group A (RVA) in pig faecal samples, and two pairs of universal primers and protocols were used for amplifying the G and P genotype. The genotyping and phylogenetic analysis of 11 genes were performed by RT-PCR and a basic bioinformatics method. A unique G4P[6] rotavirus strain, designated S2CF (RVA/Pig-tc/CHN/S2CF/2023/G4P[6]), was identified in one faecal sample from a piglet with severe diarrhoea in Guangdong, China. Whole genome sequencing and analysis suggested that the 11 segments of the S2CF strain showed a unique Wa-like genotype constellation and a typical porcine RVA genomic configuration of G4-P[6]-I1-R1-C1-M1-A8-N1-T1-E1-H1. Notably, 4 of the 11 gene segments (VP4, VP6, VP2, and NSP5) clustered consistently with human-like RVAs, suggesting independent human-to-porcine interspecies transmission. Moreover, a unique 344-nt duplicated sequence was identified for the first time in the untranslated region of NSP5. This study further reveals the genetic diversity and potential inter-species transmission of porcine rotavirus.
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BACKGROUND: Biofilms, such as those from Staphylococcus epidermidis, are generally insensitive to traditional antimicrobial agents, making it difficult to inhibit their formation. Although quercetin has excellent antibiofilm effects, its clinical applications are limited by the lack of sustained and targeted release at the site of S. epidermidis infection. OBJECTIVES: Polyethylene glycol-quercetin nanoparticles (PQ-NPs)-loaded gelatin-N,O-carboxymethyl chitosan (N,O-CMCS) composite nanogels were prepared and assessed for the on-demand release potential for reducing S. epidermidis biofilm formation. METHODS: The formation mechanism, physicochemical characterization, and antibiofilm activity of PQ-nanogels against S. epidermidis were studied. RESULTS: Physicochemical characterization confirmed that PQ-nanogels had been prepared by the electrostatic interactions between gelatin and N,O-CMCS with sodium tripolyphosphate. The PQ-nanogels exhibited obvious pH and gelatinase-responsive to achieve on-demand release in the micro-environment (pH 5.5 and gelatinase) of S. epidermidis. In addition, PQ-nanogels had excellent antibiofilm activity, and the potential antibiofilm mechanism may enhance its antibiofilm activity by reducing its relative biofilm formation, surface hydrophobicity, exopolysaccharides production, and eDNA production. CONCLUSIONS: This study will guide the development of the dual responsiveness (pH and gelatinase) of nanogels to achieve on-demand release for reducing S. epidermidis biofilm formation.
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Quitosano , Nanopartículas , Animales , Staphylococcus epidermidis/genética , Nanogeles , Gelatina/farmacología , Quercetina/farmacología , Biopelículas , Quitosano/farmacología , Quitosano/química , Gelatinasas/farmacología , Antibacterianos/farmacologíaRESUMEN
Tildipirosin has no significant inhibitory effect on intracellular bacteria because of its poor membrane permeability. To this end, tildipirosin-loaded xanthan gum-gelatin composite nanogels were innovatively prepared to improve the cellular uptake efficiency. The formation of the nanogels via interactions between the positively charged gelatin and the negatively charged xanthan gum was confirmed by powder X-ray diffraction and Fourier transform infrared. The results indicate that the optimal tildipirosin composite nanogels possessed a 3D network structure and were shaped like a uniformly dispersed ellipse, and the particle size, PDI, and ζ potential were 229.4 ± 1.5 nm, 0.26 ± 0.04, and -33.2 ± 2.2 mV, respectively. Interestingly, the nanogels exhibited gelatinase-responsive characteristics, robust cellular uptake via clathrin-mediated endocytosis, and excellent sustained release. With those pharmaceutical properties provided by xanthan gum-gelatin composite nanogels, the anti-Staphylococcus aureus activity of tildipirosin was remarkably amplified. Further, tildipirosin composite nanogels demonstrated good biocompatibility and low in vivo and in vitro toxicities. Therefore, we concluded that tildipirosin-loaded xanthan gum-gelatin composite nanogels might be employed as a potentially effective gelatinase-responsive drug delivery for intracellular bacterial infection.
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Gelatina , Gelatinasas , Polisacáridos Bacterianos , Tilosina/análogos & derivados , Nanogeles , Gelatina/químicaRESUMEN
Tumor invasion and metastasis are the main causes of tumor progression and are the leading causes of death among cancer patients. In the present study, we propose a strategy to regulate cellular signaling with a tumor metastasis-relevant cytoskeleton-associated protein 4 (CKAP4) specific aptamer for the achievement of tumor metastasis inhibition. The designed aptamer could specifically bind to CKAP4 in the cell membranes and cytoplasm to block the internalization and recycling of α5ß1 integrin, resulting in the disruption of the fibronectin-dependent cell adhesion and the weakening of the cell traction force. Moreover, the aptamer is able to impede the interaction between CKAP4 and Dickkopf1 (DKK1) to further block the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, which subsequently reduces AKT phosphorylation and inhibits the reorganization of the actin cytoskeleton in cell migration. The synergetic function of the designed aptamer in inhibiting cancer cell adhesion and blocking the PI3K signaling pathway enables efficient tumor cell metastasis suppression. The aptamer with specific targeting ability in regulating cellular signaling paves the way for cancer treatment and further provides a guiding ideology for inhibiting tumor metastasis.
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Neoplasias , Proteínas Proto-Oncogénicas c-akt , Humanos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Línea Celular Tumoral , Fosfatidilinositol 3-Quinasas/metabolismo , Transducción de Señal , Membrana Celular/metabolismo , Movimiento Celular , Neoplasias/metabolismoRESUMEN
Immunotherapy including immune checkpoint inhibition has reinvigorated the current cancer treatment field. The development of efficient cancer immunotherapies depends on a thorough understanding of the status of immune checkpoints and how they interact. However, the distribution and spatial organization changes of immune checkpoints during their interactions at the single-molecule level remain difficult to directly visualize due to the lack of in situ imaging techniques with appropriate spatial and stoichiometric resolution. Herein, we report the direct visualization and quantification of the spatial distribution and organization of CD47 on the bladder tumor cell membrane and SIRPα on the macrophage membrane by using a single-molecule localization imaging technique called quantitative direct stochastic optical reconstruction microscopy (QdSTORM). Results showed that a portion of CD47 and SIRPα was present on cell membranes as heterogeneous clusters of varying sizes and densities prior to activation. Quantitative analyses of the reconstructed super-resolution images and theoretical simulation revealed that CD47 and SIRPα were reorganized into larger clusters upon binding to each other. Furthermore, we found that blocking the immune checkpoint interaction with small-molecule inhibitors or antibodies significantly impacted the spatial clustering behavior of CD47 on bladder tumor cells, demonstrating the promise of our QdSTORM strategy in elucidating the molecular mechanisms underlying immunotherapy. This work offers a promising strategy to advance our understanding of immune checkpoint state and interactions while also contributing to the fields including signal regulation and cancer therapy.
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Neoplasias , Neoplasias de la Vejiga Urinaria , Humanos , Fagocitosis , Antígeno CD47/metabolismo , Microscopía , Neoplasias/terapia , Inmunoterapia/métodos , Membrana Celular/metabolismoRESUMEN
Northern pintail (Anas acuta) is a migratory waterfowl that can transmit various viruses. The genome sequence of a Sobemovirus was determined using metagenomic sequencing from the feces of northern pintail (Anas acuta) in Xinjiang, northwest China. The virus possesses a linear RNA molecule of 4177 bp and is most closely related to isolates SoMV-WA (GenBank accession no. HM163159.1) and ATCC PV-109 (GenBank accession no. GQ845002.2), with a nucleotide identity of 86.7%. The virus encodes four open reading frames (ORF) coding for four proteins, and phylogenetic analysis of capsid protein and RNA-dependent RNA polymerase (RdRp) showed that the strain was clustered into the species Sowbane Mosaic Virus (SoMV). The amino acid sequence identity of capsid protein was 89.6-90.9% to other isolates of SoMV, but 17.6-31.4% similar to other strains in the genus Sobemovirus, indicating a strain of Sowbane Mosaic Virus. This is the first report of SoMV in the feces of wild birds and in China, and it suggested that northern pintail likely plays an alternative role in the transmission of SoMV.
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Proteínas de la Cápside , Virus ARN , Animales , Proteínas de la Cápside/genética , Filogenia , Patos , Virus ARN/genética , Heces , Genoma Viral/genética , Sistemas de Lectura AbiertaRESUMEN
Visna/Maedi virus (VMV) is a neglected pathogen that damages sheep and goats' nervous and respiratory systems. The virus was discovered 80 years ago and has been endemic in China for nearly four decades; nevertheless, there is little information regarding Chinese isolates' genotypes and genomic characteristics. In this study, the proviral DNA of strains isolated in 1985 and 1994 were extracted, and the proviral DNA was subjected to Illumina sequencing combined with Sanger sequencing of poor coverage regions. The results showed that the two isolates were clustered with genotype A2 and shared 78.3%-89.1% similarity to reference VMV genome sequences, with the highest similarity (88.7%-89.1%) to the USA strain USMARC-200212120-r (accession no. MT993908.1) and lowest similarity (78.3%-78.5%) to the Italian strain SRLV009 (accession no. MG554409.1). A maximum-likelihood tree showed that the Chinese VMV strains and the USA strain 1150 (accession no. MH916859.1) comprise a monophyletic group with a short tree branch. Our data filled the gap in genomic analysis and viral evolution in Chinese VMV strains, and would be benefit China's source-tracing and eradication program development in China.
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Pathogenic biofilms are up to 1000-fold more drug-resistant than planktonic pathogens and cause about 80% of all chronic infections worldwide. The lack of prompt and reliable biofilm identification methods seriously prohibits the diagnosis and treatment of biofilm infections. Here, we developed a machine-learning-aided cocktail assay for prompt and reliable biofilm detection. Lanthanide nanoparticles with different emissions, surface charges, and hydrophilicity are formulated into the cocktail kits. The lanthanide nanoparticles in the cocktail kits can offer competitive interactions with the biofilm and further maximize the charge and hydrophilicity differences between biofilms. The physicochemical heterogeneities of biofilms were transformed into luminescence intensity at different wavelengths by the cocktail kits. The luminescence signals were used as learning data to train the random forest algorithm, and the algorithm could identify the unknown biofilms within minutes after training. Electrostatic attractions and hydrophobic-hydrophobic interactions were demonstrated to dominate the binding of the cocktail kits to the biofilms. By rationally designing the charge and hydrophilicity of the cocktail kit, unknown biofilms of pathogenic clinical isolates were identified with an overall accuracy of over 80% based on the random forest algorithm. Moreover, the antibiotic-loaded cocktail nanoprobes efficiently eradicated biofilms since the nanoprobes could penetrate deep into the biofilms. This work can serve as a reliable technique for the diagnosis of biofilm infections and it can also provide instructions for the design of multiplex assays for detecting biochemical compounds beyond biofilms.
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Infecciones Bacterianas , Elementos de la Serie de los Lantanoides , Nanopartículas del Metal , Antibacterianos/química , Biopelículas , Humanos , Aprendizaje Automático , Pruebas de Sensibilidad MicrobianaRESUMEN
Lumpy skin disease caused by Lumpy skin disease virus (LSDV) is a severe systemic disease affecting cattle and other ruminants. Lumpy skin disease was first reported in northwest China in August 2019 and has severely threatened the cattle breeding industry in China. However, there have been limited genomic studies of LSDV from the first outbreak and its subsequent epidemics. This study aims to characterize the comparative genomic evolution of the LSDV strain from the first outbreak in China. The etiological agent was isolated in a Madin-Darby bovine kidney cell culture and subsequently identified by PCR and Sanger sequencing of six selected genes. The genome sequence was determined using Illumina sequencing and analyzed through genome alignment and phylogenetic tree. The results showed that all six genes were successfully amplified and genetically clustered into LSDV. The virus presented the highest homology to strain China/GD01/2020, which shared 100% identities among 150 open reading frames (ORFs), and 97.1-99.7% identities among additional 6 ORFs. Bayesian inference tree analysis revealed that the virus shared a common ancestor with LSDV strains from China and Vietnam. The study provides an additional genomic data for LSDV tracking and control in China and neighboring countries.
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Hepatitis E virus (HEV) causes infections in humans and a wide range of animal hosts. Wild boar is an important natural reservoir of HEV genotypes 3−6 (HEV-3−HEV-6), but comparative analysis of HEV infections in both feral and farmed wild boars remains limited. In this study, samples from 599 wild boars were collected during 2017−2020, including 121 feral wild boars (collected 121 fecal, 121 serum, and 89 liver samples) and 478 farmed wild boars (collected 478 fecal and 478 serum samples). The presence of anti-HEV IgG antibodies were detected by the HEV-IgG enzyme-linked immunosorbent assay (ELISA) kit. HEV RNA was detected by reverse transcription polymerase chain reaction (RT-PCR), targeting the partial ORF1 genes from fecal and liver samples, and the obtained genes were further genotyped by phylogenetic analysis. The results showed that 76.2% (95% CI 72.1−79.9) of farmed wild boars tested anti-HEV IgG seropositive, higher than that in feral wild boars (42.1%, 95% CI 33.2−51.5, p < 0.001). HEV seropositivity increased with age. Wild boar HEV infection presented a significant geographical difference (p < 0.001), but not between sex (p = 0.656) and age (p = 0.347). HEV RNA in fecal samples was detected in 13 (2.2%, 95% CI 1.2−3.7) out of 599 wild boars: 0.8% (95% CI 0.0−4.5, 1/121) of feral wild boars and 2.5% (95% CI 1.3−4.3, 12/478) of farmed wild boars. Phylogenetic analysis showed that all these viruses belonged to genotype HEV-4, and further grouped into sub-genotypes HEV-4a, HEV-4d, and HEV-4h, of which HEV-4a was first discovered in the wild boar populations in China. Our results suggested that farms could be a setting for amplification of HEV. The risk of HEV zoonotic transmission via rearing and consumption of farmed wild boars should be further assessed.
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Virus de la Hepatitis E , Hepatitis E , Enfermedades de los Porcinos , Porcinos , Animales , Humanos , Sus scrofa , Prevalencia , Filogenia , Granjas , ARN Viral/genética , ARN Viral/análisis , Enfermedades de los Porcinos/epidemiología , Hepatitis E/epidemiología , Hepatitis E/veterinaria , Anticuerpos Antihepatitis , China/epidemiologíaRESUMEN
Bovine ephemeral fever (BEF), caused by the bovine ephemeral fever virus (BEFV), is associated with an acute febrile infection in cattle and widespread in tropical and subtropical areas, leading to great economic losses to cattle and milk industry. However, no efficacious BEF vaccine is currently available in China. Herein, we generated a recombinant rabies virus (RABV) expressing BEFV glycoprotein (LBNSE-BG), utilizing a reverse genetics system based on the recombinant rabies virus strain LBNSE. It was found that mice immunized with LBNSE-BG produced robust neutralizing antibodies against both BEFV and RABV, and developed complete protection from lethal RABV challenge. Further studies showed that LBNSE-BG activated more dendritic cells (DCs), B cells and T cells in immunized mice than the parent virus LBNSE. Collectively, these findings demonstrate that the recombinant LBNSE-BG described here has the potential to be developed as a cost-effective and efficacious bivalent vaccine for cattle use in endemic areas of BEF and rabies.
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Virus de la Fiebre Efímera Bovina/inmunología , Fiebre Efímera/prevención & control , Virus de la Rabia/inmunología , Vacunas Virales/inmunología , Animales , Bovinos , Enfermedades de los Bovinos/inmunología , Enfermedades de los Bovinos/prevención & control , Enfermedades de los Bovinos/virología , Fiebre Efímera/inmunología , Fiebre Efímera/virología , Femenino , Ratones , Ratones Endogámicos BALB C , Microorganismos Modificados Genéticamente/inmunologíaRESUMEN
Wild ruminants are at risk for zoonotic pathogen infection as a result of interactions with domestic animals and humans. One way to assess the level of a wild ruminant disease in a population is to determine the seroprevalence of the pathogen of interest. The objective of this study was to determine the seroprevalence of five zoonotic pathogens in wild ruminants in Xinjiang, Northwest China. In 2009 and 2011-2015, 258 wild ruminant sera samples were collected from various species. Samples were obtained from 30 Siberian ibexes, 94 goitered gazelles, 6 Tibetan antelopes, 32 argali sheep, 16 roe deer, 20 blue sheep, 56 red deer, and 4 wild yaks, in 10 regions of Xinjiang. Samples were tested using antibodies against Brucella spp., Chlamydophila abortus, Coxiella burnetii, Toxoplasma gondii, and West Nile virus. Seropositivity was detected for all five pathogens, with detection rates of Brucella spp., C. abortus, C. burnetii, T. gondii, and West Nile virus of 2.3% (95% confidence interval [CI], 0.5-4.2%), 6.2% (95% CI, 3.3-9.1%), 7.8% (95% CI, 4.5-11.0%), 2.3% (95% CI, 0.5-4.2%), and 0.8% (95% CI, 0-1.8%), respectively. The level of pathogens differed for different species and different regions. The results indicate that seropositivity to zoonotic pathogens is common among wild ruminants in Xinjiang, Northwest China, with C. burnetii and C. abortus detected at the highest levels. This study provides a baseline for future assessment of spillover events.
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Animales Salvajes/microbiología , Animales Salvajes/parasitología , Rumiantes/microbiología , Rumiantes/parasitología , Zoonosis/epidemiología , Animales , Bacterias/clasificación , Bacterias/aislamiento & purificación , Infecciones Bacterianas/epidemiología , Infecciones Bacterianas/veterinaria , China/epidemiología , Rumiantes/virología , Estudios Seroepidemiológicos , Toxoplasma/aislamiento & purificación , Toxoplasmosis Animal/epidemiología , Fiebre del Nilo Occidental/epidemiología , Fiebre del Nilo Occidental/veterinaria , Fiebre del Nilo Occidental/virología , Virus del Nilo Occidental/aislamiento & purificaciónRESUMEN
Both severe fever with thrombocytopenia syndrome (SFTS) and rabies are severe zoonotic diseases. As co-hosts of rabies virus (RABV) and SFTS virus (SFTSV), dogs and cats could not only be infected but also transmit the virus to human. Hence, developing a bivalent vaccine against both SFTS and rabies is urgently needed. In this study, we generated a recombinant replication-deficient human adenovirus type 5 (Ad5) co-expressing RABV G and SFTSV Gn (Ad5-G-Gn) and evaluated its immunogenicity and efficacy in mice. Ad5-G-Gn immunization activated more dendritic cells (DCs) and B cells in lymph nodes (LNs) and induced Th1-/Th2-mediated responses in splenocytes, leading to robust production of neutralizing antibodies against SFTSV and RABV. In addition, single dose of Ad5-G-Gn conferred mice complete protection against lethal RABV challenge and significantly reduced splenic SFTS viral load. Therefore, our data support further development of Ad5-G-Gn as a potential bivalent vaccine candidate against SFTS and rabies for dog and cat use.
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Detection of biomarkers in complex samples is a significant health plan strategy for medical diagnosis, therapy monitoring, and health management. However, high background noise resulting from impurities and other analytes in complex samples has hampered the improvement of detection sensitivity and accuracy. Herein, an ultralow background biochip based on time-gated luminescent probes supported by photonic crystals (PCs) was successfully developed for detection of bladder cancer (BC)-related miRNA biomarkers with high sensitivity and specificity in urine samples. Coupled with the time-gated luminescence of long-lifetime luminescence probes and the luminescence-enhanced capability of PCs, the short-lived autofluorescence can be efficiently removed; thus, the detection sensitivity will be significantly improved. Benefiting from these merits, a detection limit of 26.3 fM is achieved. Furthermore, the biochip exhibits excellent performance in urinary miRNA detection, and good recoveries are also obtained. The developed biochip possesses unique properties of ultralow background and luminescence enhancement, thus offering a suitable tool for the detection of BC-related miRNA in urine. With rational design of probe sequences, the biochip holds great potential for many other biomarkers in real patient samples, making it valuable in areas such as medical diagnosis and disease evaluation.
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Biomarcadores de Tumor/orina , Técnicas Biosensibles , Sustancias Luminiscentes/química , Mediciones Luminiscentes , MicroARNs/orina , Neoplasias de la Vejiga Urinaria/química , Humanos , Microscopía Electrónica de Transmisión , Tamaño de la Partícula , Propiedades de Superficie , Factores de Tiempo , Neoplasias de la Vejiga Urinaria/orinaRESUMEN
Global warming is widely believed to extend the length of plant growing season (LOS) through advancing the start (SOS) and delaying the end (EOS) of plant growing season. However, divergent directions of phenological changes under current climate warming have been frequently reported but poorly understood. Here we collate the long-term filed phenological and climatic records at 8 sites in Inner Mongolian grassland to assess how climate changes regulate the phenological variations with divergent directions and magnitudes in this region. We found that the spring climatic changes (e.g., changes in air temperature and precipitation during March and April) correlate well with variations in SOS. However, our in situ observations show divergent changes in SOS across space, which can be attributed to the generally insignificant changes of climates during the preseasons of SOS. The climate warming prior to the end of plant growing season (EOS) was generally significant at most sites. Nevertheless, the effects of such warming on changes in EOS were possibly overshadowed by the impacts of precipitation in this arid/semi-arid region. As a result, the temporal variations in EOS distribute divergent directions and magnitudes across space and species. Using climate attributes during the preseason of EOS alone can hardly explain changes in EOS. Alternatively, by introducing changes in SOS as an additional driving factor, variations in EOS can be well represented. We therefore infer that plant phenologies can divergently response to current global warming (depending on the seasonal patterns of warming). Moreover, other influential factors such as precipitation and the interactions between the timings of different phenological stages are also needed in predicting the phenological dynamics.
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Cambio Climático , Pradera , Desarrollo de la Planta , China , Calentamiento Global , Estaciones del Año , TemperaturaRESUMEN
We conducted a serological survey to detect antibodies against avian influenza virus (AIV) in Gazella subgutturosa, Canis lupus, Capreolus pygargus, Sus scrofa, Cervus elaphus, Capra ibex, Ovis ammon, Bos grunniens and Pseudois nayaur in Xinjiang, China. Two hundred forty-six sera collected from 2009 to 2013 were assayed for antibodies against H5, H7 and H9 AIVs using hemagglutination inhibition (HI) tests and a pan-influenza competitive ELISA. Across all tested wildlife species, 4.47 % harbored anti-AIV antibodies that were detected by the HI assay. The seroprevalence for each AIV subtype across all species evaluated was 0 % for H5 AIV, 0.81 % for H7 AIV, and 3.66 % for H9 AIV. H7-reactive antibodies were found in Canis lupus (9.09 %) and Ovis ammon (4.55 %). H9-reactive antibodies were found in Gazella subgutturosa (4.55 %), Canis lupus (27.27 %), Pseudois nayaur (23.08 %), and Ovis ammon (4.55 %). The pan-influenza competitive ELISA results closely corresponded to the cumulative prevalence of AIV exposure as measured by subtype-specific HI assays, suggesting that H7 and H9 AIV subtypes predominate in the wildlife species evaluated. These data provide evidence of prior infection with H7 and H9 AIVs in non-avian wildlife in Xinjiang, China.
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Animales Salvajes , Virus de la Influenza A/aislamiento & purificación , Infecciones por Orthomyxoviridae/veterinaria , Animales , China/epidemiología , Ensayo de Inmunoadsorción Enzimática/veterinaria , Virus de la Influenza A/clasificación , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/virología , Estudios SeroepidemiológicosRESUMEN
Regulation of protein activity is vital for understanding the molecular mechanism of biological activities. In this work, protein activity is suppressed by proximity-dependent surface hybridization and subsequently restored by near-infrared (NIR) light stimulation. Specifically, by constructing closed-loop structures with two aptamer-based affinity ligands, significantly enhanced inhibition of thrombin activity is achieved compared to traditional single affinity ligand based inhibitors. Furthermore, the activity of inhibited thrombin is efficiently recovered under NIR light stimulation by using gold nanorods (AuNRs) as photothermal agents to disrupt the closed-loop structures. Real-time and in situ monitoring of the conversion of fibrinogen into fibrin catalyzed by both inhibited and recovered thrombin was performed with light scattering spectroscopy and laser scanning confocal microscopy (LSCM). Thrombin trapped in the closed-loop structures shows slow reaction kinetics, while the photothermally liberated thrombin displays largely recovered catalytic activity. Human plasma was further employed to demonstrate that both the inhibited and restored thrombin can be applied to clotting reaction in reality. This strategy provides protein activity regulation for studying the molecular basis of biological activities and can be further applied to potential areas such as metabolic pathway regulation and the development of protein-inhibitor pharmaceuticals.
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Aptámeros de Nucleótidos/química , Aptámeros de Nucleótidos/metabolismo , Rayos Infrarrojos , Trombina/antagonistas & inhibidores , Trombina/metabolismo , Aptámeros de Nucleótidos/genética , Secuencia de Bases , Oro/química , Humanos , Ligandos , Modelos Moleculares , Nanotubos/química , Hibridación de Ácido Nucleico , Conformación Proteica , Resonancia por Plasmón de Superficie , Trombina/químicaRESUMEN
Foot-and-mouth disease (FMD) is a highly contagious disease of domestic and wild ruminants that is caused by FMD virus (FMDV). FMD outbreaks have occurred in livestock-containing regions worldwide. Apigenin, which is a flavonoid naturally existing in plant, possesses various pharmacological effects, including anti-inflammatory, anticancer, antioxidant and antiviral activities. Results show that apigenin can inhibit FMDV-mediated cytopathogenic effect and FMDV replication in vitro. Further studies demonstrate the following: (i) apigenin inhibits FMDV infection at the viral post-entry stage; (ii) apigenin does not exhibit direct extracellular virucidal activity; and (iii) apigenin interferes with the translational activity of FMDV driven by internal ribosome entry site. Studies on applying apigein in vivo are required for drug development and further identification of potential drug targets against FDMV infection.