Polarized focal adhesion kinase activity within a focal adhesion during cell migration.

Focal adhesion kinase (FAK) relays integrin signaling from outside to inside cells and contributes to cell adhesion and motility. However, the spatiotemporal dynamics of FAK activity in single FAs is unclear due to the lack of a robust FAK reporter, which limits our understanding of these essential biological processes. Here we have engineered a genetically encoded FAK activity sensor, dubbed FAK-separation of phases-based activity reporter of kinase (SPARK), which visualizes endogenous FAK activity in living cells and vertebrates. Our work reveals temporal dynamics of FAK activity during FA turnover. Most importantly, our study unveils polarized FAK activity at the distal tip of newly formed single FAs in the leading edge of a migrating cell. By combining FAK-SPARK with DNA tension probes, we show that tensions applied to FAs precede FAK activation and that FAK activity is proportional to the strength of tension. These results suggest tension-induced polarized FAK activity in single FAs, advancing the mechanistic understanding of cell migration.

Genome-wide identification of XTH gene family in Musa acuminata and response analyses of MaXTHs and xyloglucan to low temperature.

Banana (Musa spp.) production is seriously threatened by low temperature (LT) in tropical and subtropical regions. Xyloglucan endotransglycosylase/hydrolases (XTHs) are considered chief enzymes in cell wall remodelling and play a central role in stress responses. However, whether MaXTHs are involved in the low temperature stress tolerance in banana is not clear. Here, the identification and characterization of MaXTHs were carried out, followed by prediction of their cis-acting elements and protein-protein interactions. In addition, candidate MaXTHs involved in banana tolerance to LT were screened through a comparison of their responses to LT between tolerant and sensitive cultivars using RNA-Seq analysis. Moreover, immunofluorescence (IF) labelling was employed to compare changes in the temporal and spatial distribution of different types of xyloglucan components between these two cultivars upon stress. In total, 53 MaXTHs have been identified, and all were predicted to be located in the cell wall, 14 of them also in the cytoplasm. Only 11 MaXTHs have been found to interact with other proteins. Among 16 MaXTHs with LT responsiveness elements, MaXTH26/29/32/35/50 (Group I/II members) and MaXTH7/8 (Group IIIB members) might be involved in banana tolerance to LT stress. IF results suggested that the content of xyloglucan components recognized by CCRC-M87/103/104/106 antibodies might be negatively related to banana chilling tolerance. In conclusion, we have identified the MaXTH gene family and assessed cell wall re-modelling under LT stress. These results will be beneficial for banana breeding against stresses and enrich the cell wall-mediated resistance mechanism in plants to stresses.

Ethacridine inhibits SARS-CoV-2 by inactivating viral particles.

The respiratory disease COVID-19 is caused by the coronavirus SARS-CoV-2. Here we report the discovery of ethacridine as a potent drug against SARS-CoV-2 (EC50 ~ 0.08 µM). Ethacridine was identified via high-throughput screening of an FDA-approved drug library in living cells using a fluorescence assay. Plaque assays, RT-PCR and immunofluorescence imaging at various stages of viral infection demonstrate that the main mode of action of ethacridine is through inactivation of viral particles, preventing their binding to the host cells. Consistently, ethacridine is effective in various cell types, including primary human nasal epithelial cells that are cultured in an air-liquid interface. Taken together, our work identifies a promising, potent, and new use of the old drug via a distinct mode of action for inhibiting SARS-CoV-2.

Research progress in methods for detecting neutralizing antibodies against SARS-CoV-2.

The emergence of SARS-CoV-2 has seriously affected the lives of people worldwide. Clarifying the attenuation rule of SARS-CoV-2 neutralizing antibody (NAb) in vivo is the key to prevent reinfection and recurrence of virus. Currently, the commonly used methods for detecting NAb include virus neutralization tests, pseudovirus neutralization assays, lateral flow immunochromatography and enzyme-linked immunosorbent assays. The detection of NAb not only can be used to evaluate the level of immunity after vaccination or infection but also can provide important theoretical support for virus reinfection, recurrence and vaccine iteration. In this research, the related technologies of SARS-CoV-2 NAb detection were reviewed, aiming to provide better research ideas for SARS-CoV-2 epidemic prevention and control.

Different responses of banana classical AGP genes and cell wall AGP components to low-temperature between chilling sensitive and tolerant cultivars.

KEY MESSAGE: Seventeen classical MaAGPs and 9 MbAGPs were identified and analyzed. MaAGP1/2/6/9/16/17, the antigens of JIM13 and LM2 antibodies are likely to be involved in banana chilling tolerance. Classical arabinogalactan proteins (AGPs) belong to glycosylphosphatidylinositol-anchored proteins, which are proved to be involved in signaling and cell wall metabolism upon stresses. However, rare information is available on the roles of classical AGPs in low temperature (LT) tolerance. Cultivation of banana in tropical and subtropical region is seriously threatened by LT stress. In the present study, 17 classical MaAGPs and nine MbAGPs in banana A and B genome were identified and characterized, respectively. Great diversity was present among different classical MaAGP/MbAGP members while five members (AGP3/6/11/13/14) showed 100% identity between these two gene families. We further investigated different responses of classical AGPs to LT between a chilling sensitive (CS) and tolerant (CT) banana cultivars. In addition, different changes in the temporal and spatial distribution of cell wall AGP components under LTs between these two cultivars were compared using immunofluorescence labeling. Seven classical MbAGPs were upregulated by LT(s) in the CT cultivar. Classical MaAGP4/6 was induced by LT(s) in both cultivars while MaAGP1/2/9/16/17 only in the CT cultivar. Moreover, these genes showed significantly higher transcription abundance in the CT cultivar than the CS one under LT(s) except classical MaAGP4. Similar results were observed with the epitopes of JIM13 and LM2 antibodies. The antigens of these antibodies and classical MaAGP1/2/6/9/16/17 might be related to LT tolerance of banana. These results provide additional information about plant classical AGPs and their involvement in LT tolerance, as well as their potential as candidate genes to be targeted when breeding CT banana.

Contributions of PARP-1 rs1136410 C>T polymorphism to the development of cancer.

Poly(ADP-ribose) polymerase-1 (PARP-1) is a nuclear chromatin-associated enzyme involved in the DNA damage response. SNP rs1136410 C>T, the most studied polymorphism in PARP-1 gene, is highly implicated in the susceptibility of cancer. However, the roles of PARP-1 rs1136410 C>T on cancer risk vary from different studies. We comprehensively screened all qualified publications from several databases, including PubMed, EMBASE, MEDLINE, CNKI and Wanfang. The searching was updated to April 2020. Our meta-analysis included 60 articles with 65 studies, comprised of a total of 23 996 cases with cancer and 33 015 controls. Overall, pooled data showed that the PARP-1 rs1136410 C>T polymorphism was significantly but a border-line associated with an increased risk of overall cancer (CC vs. TT/TC: OR = 1.11, 95% CI = 1.00-1.24; C vs T: OR = 1.07, 95% CI = 1.01-1.14). Subgroup analysis indicated that rs1136410 C allele contributed to high risk among gastric, thyroid, and cervical cancer, but lower risk among brain cancer. Furthermore, increased cancer risk was detected in the subgroups of Asian, controls from population-based design studies, and HWE ≤ 0.05 studies. Sensitivity analysis and Egger's test showed that results of the meta-analysis were fairly stable. The current study indicated that PARP1 rs1136410 C>T polymorphism may have an impact on certain types of cancer susceptibility.

Genome-wide analyses of banana fasciclin-like AGP genes and their differential expression under low-temperature stress in chilling sensitive and tolerant cultivars.

KEY MESSAGES: Thirty MaFLAs vary in their molecular features. MaFLA14/18/27/29 are likely to be involved in banana chilling tolerance by facilitating the cold signaling pathway and enhancing the cell wall biosynthesis. Although several studies have identified the molecular functions of individual fasciclin-like arabinogalactan protein (FLA) genes in plant growth and development, little information is available on their involvement in plant tolerance to low-temperature (LT) stress, and the related underlying mechanism is far from clear. In this study, the different expression of FLAs of banana (Musa acuminata) (MaFLAs) in the chilling-sensitive (CS) and chilling-tolerant (CT) banana cultivars under natural LT was investigated. Based on the latest banana genome database, a genome-wide identification of this gene family was done and the molecular features were analyzed. Thirty MaFLAs were distributed in 10 out of 11 chromosomes and these clustered into four major phylogenetic groups based on shared gene structure. Twenty-four MaFLAs contained N-terminal signal, 19 possessed predicted glycosylphosphatidylinositol (GPI), while 16 had both. Most MaFLAs were downregulated by LT stress. However, MaFLA14/18/29 were upregulated by LT in both cultivars with higher expression level recorded in the CT cultivar. Interestingly, MaFLA27 was significantly upregulated in the CT cultivar, but the opposite occurred for the CS cultivar. MaFLA27 possessed only N-terminal signal, MaFLA18 contained only GPI anchor, MaFLA29 possessed both, while MaFLA14 had neither. Thus, it was suggested that the accumulation of these FLAs in banana under LT could improve banana chilling tolerance through facilitating cold signal pathway and thereafter enhancing biosynthesis of plant cell wall components. The results provide background information of MaFLAs, suggest their involvement in plant chilling tolerance and their potential as candidate genes to be targeted when breeding CT banana.

MicroRNA-146b-5p protects oligodendrocyte precursor cells from oxygen/glucose deprivation-induced injury through regulating Keap1/Nrf2 signaling via targeting bromodomain-containing protein 4.

The injury of oligodendrocyte precursor cells (OPCs) contributes to the pathology of hypoxic-ischemic encephalopathy in newborns. MicroRNAs (miRNAs) have emerge as critical regulators of hypoxic-ischemic encephalopathy; however, the role of miRNAs in regulating OPC injury remains largely unknown. MiRNA-146b-5p (miR-146b-5p) has been reported to exert a cytoprotective function under various pathological conditions. In this study, we aimed to investigate the potential function of miR-146b-45p in regulating oxygen/glucose deprivation (OGD)-induced injury of OPCs and explore the underlying mechanism. Herein, we found that miR-146b-5p expression was reduced in OPCs exposed to OGD. Functional experiments showed that miR-146b-5p overexpression promoted cell growth and viability, and reduced the apoptosis and oxidative stress in OGD-injured OPCs, while miR-146b-5p inhibition showed an opposite effect. Interestingly, bromodomain-containing protein 4 (Brd4) was identified as a target gene of miR-146b-5p. Brd4 expression was negatively modulated by miR-146b-5p in OPCs. Moreover, the inhibition of Brd4 showed a protective effect in OGD-injured OPCs. Notably, miR-146b-5p overexpression or Brd4 inhibition down-regulated kelch-like ECH-associated protein 1 (Keap1) expression, but promoted nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear expression and enhanced the transcriptional activity of the antioxidant response element (ARE). However, the overexpression of Brd4 significantly abrogated miR-146b-5p mediated protection effect in OGD exposed OPCs. Taken together, these results demonstrate that the overexpression of miR-146b-5p attenuates OGD-induced injury in OPCs through targeting Brd4 and regulating Keap1/Nrf2/ARE antioxidant signaling, suggesting a potential role of miR-146b-5p/Brd4 in the pathophysiology of neonatal hypoxic-ischemic brain injury.

Comparative Digital Gene Expression Analysis of Tissue-Cultured Plantlets of Highly Resistant and Susceptible Banana Cultivarsin Response to Fusarium oxysporum.

Banana Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (Foc) is one of the most destructive soil-borne diseases. In this study, young tissue-cultured plantlets of banana (Musa spp. AAA) cultivars differing in Foc susceptibility were used to reveal their differential responses to this pathogen using digital gene expression (DGE). Data were evaluated by various bioinformatic tools (Venn diagrams, gene ontology (GO) annotation and Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses) and immunofluorescence labelling method to support the identification of gene candidates determining the resistance of banana against Foc. Interestingly, we have identified MaWRKY50 as an important gene involved in both constitutive and induced resistance. We also identified new genes involved in the resistance of banana to Foc, including several other transcription factors (TFs), pathogenesis-related (PR) genes and some genes related to the plant cell wall biosynthesis or degradation (e.g., pectinesterases, ß-glucosidases, xyloglucan endotransglucosylase/hydrolase and endoglucanase). The resistant banana cultivar shows activation of PR-3 and PR-4 genes as well as formation of different constitutive cell barriers to restrict spreading of the pathogen. These data suggest new mechanisms of banana resistance to Foc.

Genome-wide transcriptome profiling provides overwintering mechanism of Agropyron mongolicum.

BACKGROUND: The mechanism of winter survival for perennials involves multiple levels of gene regulation, especially cold resistance. Agropyron mongolicum is one important perennial grass species, but there is little information regarding its overwintering mechanism. We performed a comprehensive transcriptomics study to evaluate global gene expression profiles regarding the winter survival of Agropyron mongolicum. A genome-wide gene expression analysis involving four different periods was identified. Twenty-eight coexpression modules with distinct patterns were performed for transcriptome profiling. Furthermore, differentially expressed genes (DEGs) and their functional characterization were defined using a genome database such as NT, NR, COG, and KEGG. RESULT: A total of 79.6% of the unigenes were characterized to be involved in 136 metabolic pathways. In addition, the expression level of ABA receptor genes, regulation of transcription factors, and a coexpression network analysis were conducted using transcriptome data. We found that ABA receptors regulated downstream gene expression by activating bZIP and NAC transcription factors to improve cold resistance and winter survival. CONCLUSION: This study provides comprehensive transcriptome data for the characterization of overwintering-related gene expression profiles in A. mongolicum. Genomics resources can help provide a better understanding of the overwintering mechanism for perennial gramineae species. By analyzing genome-wide expression patterns for the four key stages of tiller bud development, the functional characteristics of the DEGs were identified that participated in various metabolic pathways and have been shown to be strongly associated with cold tolerance. These results can be further exploited to determine the mechanism of overwintering in perennial gramineae species.

Amperometric Monitoring of Sensory-Evoked Dopamine Release in Awake Larval Zebrafish.

Dopamine plays crucial roles in a broad spectrum of brain functions, and neural circuit mechanisms underlying dopaminergic regulation have been intensively studied in the past decade. As larval zebrafish have relatively simple and highly conserved dopaminergic systems, it can serve as an ideal vertebrate animal model to tackle this issue at a whole-brain scale. For this purpose, it is important to develop methods for monitoring endogenous dopamine release in intact larval zebrafish. Here, we developed a real-time method to monitor dopamine release at high spatiotemporal resolution in the brain of awake larval zebrafish using carbon fiber microelectrodes. As an example for application, we combined this method with genetic tools and in vivo calcium imaging and found that food extract can activate pretectal dopaminergic neurons, which in turn release dopamine at the visual center through their projection, providing a dopaminergic circuit mechanism for olfactory modulation of visual functions. Thus, our study demonstrates, for the first time, the utility of carbon fiber microelectrodes for monitoring sensory-evoked dopamine release in the brain of an awake small organism. SIGNIFICANCE STATEMENT: With carbon fiber microelectrodes, we have succeeded in monitoring sensory-evoked dopamine release in the brain of an awake small organism for the first time. By elucidating the circuitry origin of the dopamine release, we illustrated the potential application of this method in dissection of the neural circuitry mechanisms underlying dopaminergic neuromodulation.

Effect of Live Poultry Market Closure on Avian Influenza A(H7N9) Virus Activity in Guangzhou, China, 2014.

We assessed the effect of closing live poultry markets in China on influenza A(H7N9) virus detection and viability. Intensive sampling was carried out before, during, and after a 2-week citywide market closure; the markets were cleaned and disinfected at the beginning of the closure period. Swab samples were collected at different sites within the markets and tested for H7N9 by real-time reverse transcription PCR and culture. During the closure, H7N9 viral RNA detection and isolation rates in retail markets decreased by 79% (95% CI 64%-88%) and 92% (95% CI 58%-98%), respectively. However, viable H7N9 virus could be cultured from wastewater samples collected up to 2 days after the market closure began. Our findings indicates that poultry workers and the general population are constantly exposed to H7N9 virus at these markets and that market closure and disinfection rapidly reduces the amount of viable virus.

Circulation of Coxsackievirus A6 in hand-foot-mouth disease in Guangzhou, 2010-2012.

BACKGROUND: Hand, foot and mouth disease (HFMD) is usually caused by Enterovirus 71(EV71), and Coxsackievirus A16 (CV-A16) in Guangzhou, the biggest city of South China. However, Coxsackievirus A6 (CV-A6) were observed increased dramatically from 2010-2012. METHODS: In order to understand and to describe the epidemiologic and genetic characteristics of CV-A6, specimens of 5482 suspected HFMD cases were collected and examined by real-time fluorescence PCR. All samples positive for enteroviruses were analyzed by descriptive statistics. Phylogenetic analysis of CV-A6 based on the VP1 sequences was performed to investigate molecular and evolutionary characteristics. RESULTS: Coxsackievirus A6 increased dramatically from 9.04% in 2010 to 23.21% in 2012 and became one of the main causative agents of HFMD in Guangzhou. CV-A6 attack rates were highest in one to two year olds (33.14%). Typical clinic symptoms of CV-A6 HFMD include fever (589/720, 81.81%), maculopopular rash and vesicular exanthema around the perioral area (408/720, 56.66%), intraoral (545/720, 75.69%), the buttock (395/720, 54.86%), the trunk (244/720, 33.89%), the knee (188/720, 26.11%), and the dorsal aspects of hands (437/720, 60.69%). Phylogenetic analysis showed the CV-A6 isolates in this study belonged to Cluster A1 and were similar to those found in Shanghai in 2011 and 2012 (JX495148, KC414735), Shenzhen in 2011 (JX473394), Japan in 2011 (AB649243, AB649246), France in 2010(HE572928), Thailand in 2012(JX556564) and Israel in 2012 and 2013(.KF991010, KF991012).

Short-term effects of meteorological factors on children hand, foot and mouth disease in Guangzhou, China.

Hand, foot and mouth disease (HFMD) is a contagious viral illness that commonly affects infants and children. The underlying risk factors have not yet been systematically examined. This study analyzed the short-term effects of meteorological factors on children HFMD in Guangzhou, China. Daily count of HFMD among children younger than 15 years and meteorological variables from 2009 to 2011 were collected to construct the time series. A generalized additive model was applied to estimate the effects of meteorological factors on HFMD occurrence, after adjusting for long-term trend, seasonal trend, day of week, and public holidays. A negative association between temperature and children HFMD occurrence was observed at lag days 1-3, with the relative risk (RR) for a 1 °C increase on lag day 2 being 0.983 (95% confidence intervals (CI) 0.977 to 0.989); positive effect was found for temperature at lag days 5-9, with the highest effect at lag day 6 (RR = 1.014, 95% CI 1.006 to 1.023). Higher humidity was associated with increased HFMD at lag days 3-10, with the highest effect at lag day 8 (RR = 1.009 for 1% increase in relative humidity, 95% CI 1.007 to 1.010). And we also observed significant positive effect for rainfall at lag days 4 and 8 (RR = 1.001, 95% CI 1.000 to 1.002) for 1-mm increase. Subgroup analyses showed that the positive effects of temperature were more pronounced among younger children. This study suggests that meteorological factors might be important predictors of children HFMD occurrence in Guangzhou.

Zinc-doped bioactive glass-functionalized polyetheretherketone to enhance the biological response in bone regeneration.

Polyether ether ketone (PEEK) is gaining recognition as a highly promising polymer for orthopedic implants, attributed to its exceptional biocompatibility, ease of processing, and radiation resistance. However, its long-term in vivo application faces challenges, primarily due to suboptimal osseointegration from postimplantation inflammation and immune reactions. Consequently, biofunctionalization of PEEK implant surfaces emerges as a strategic approach to enhance osseointegration and increase the overall success rates of these implants. In our research, we engineered a multifaceted PEEK implant through the in situ integration of chitosan-coated zinc-doped bioactive glass nanoparticles (Zn-BGNs). This novel fabrication imbues the implant with immunomodulatory capabilities while bolstering its osseointegration potential. The biofunctionalized PEEK composite elicited several advantageous responses; it facilitated M2 macrophage polarization, curtailed the production of inflammatory mediators, and augmented the osteogenic differentiation of bone marrow mesenchymal stem cells. The experimental findings underscore the vital and intricate role of biofunctionalized PEEK implants in preserving normal bone immunity and metabolism. This study posits that utilizing chitosan-BGNs represents a direct and effective method for creating multifunctional implants. These implants are designed to facilitate biomineralization and immunomodulation, making them especially apt for orthopedic applications.

Grhl2 deficiency impairs otic development and hearing ability in a zebrafish model of the progressive dominant hearing loss DFNA28.

Congenital and progressive hearing impairment is a common distressing disease. The progressive dominant hearing loss DFNA28 in human is associated with a frameshift mutation of Grainyhead-like 2 (GRHL2) but its etiology and mechanism remain unknown. Here we report a zebrafish grhl2b(T086) mutant line in which grhl2b expression is interrupted by an insertion of a Tol2 transposon element. The mutants exhibit enlarged otocysts, smaller or eliminated otoliths, malformed semicircular canals, insensitiveness to sound stimulation and imbalanced swimming motion. Since grainyhead-like family members can regulate epithelial adhesion, we examined the expression of some genes encoding junction proteins in mutants. We show that the expression of claudin b (cldnb) and epcam is abolished or dramatically reduced and apical junctional complexes are abnormal in otic epithelial cells of mutant embryos. Co-injection of cldnb and epcam mRNA could largely rescue the mutant phenotype. Injection of human wild-type GRHL2 mRNA but not the mutant GRHL2 mRNA derived from DFNA28 patients into grhl2b(T086) mutant embryos could rescue the inner-ear defects. Furthermore, we demonstrate that Grhl2b directly binds to the enhancers and promotes the expression of cldnb and epcam. Thus, this work reveals an evolutionarily conserved function of Grhl2 in otic development and provides a fish model for further studying mechanisms of Grhl2-related hearing loss.

Dengue virus envelope domain III immunization elicits predominantly cross-reactive, poorly neutralizing antibodies localized to the AB loop: implications for dengue vaccine design.

Dengue virus (DENV) is a mosquito-borne virus that causes severe health problems. An effective tetravalent dengue vaccine candidate that can provide life-long protection simultaneously against all four DENV serotypes is highly anticipated. A better understanding of the antibody response to DENV envelope protein domain III (EDIII) may offer insights into vaccine development. Here, we identified 25 DENV cross-reactive mAbs from immunization with Pichia pastoris-expressed EDIII of a single or all four serotype(s) using a prime-boost protocol, and through pepscan analysis found that 60 % of them (15/25) specifically recognized the same highly conserved linear epitope aa 309-320 of EDIII. All 15 complex-reactive mAbs exhibited significant cross-reactivity with recombinant EDIII from all DENV serotypes and also with C6/36 cells infected with DENV-1, -2, -3 and -4. However, neutralization assays indicated that the majority of these 15 mAbs were either moderately or weakly neutralizing. Through further epitope mapping by yeast surface display, two residues in the AB loop, Q316 and H317, were discovered to be critical. Three-dimensional modelling analysis suggests that this epitope is surface exposed on EDIII but less accessible on the surface of the E protein dimer and trimer, especially on the surface of the mature virion. It is concluded that EDIII as an immunogen may elicit cross-reactive mAbs toward an epitope that is not exposed on the virion surface, therefore contributing inefficiently to the mAbs neutralization potency. Therefore, the prime-boost strategy of EDIII from a single serotype or four serotypes mainly elicited a poorly neutralizing, cross-reactive antibody response to the conserved AB loop of EDIII.

Molecular epidemiology of PRRSV from China's Guangxi Province between 2007 and 2009.

Porcine reproductive and respiratory syndrome (PRRS) is considered to be one of the most important infectious diseases affecting livestock. This study used gene sequence analysis of ORF5 and Nsp2 to determine the molecular epidemiology of PRRSV in different parts of the Guangxi province of China. These genes were selected due to their extensive variation within the genome. Out of 189 samples from animals suspected to have PRRS, 145 were PRRSV RNA positive. ORF5 and Nsp2 gene sequence analysis of 31 of these samples showed that all of the Guangxi isolates were of type 2. A phylogenetic tree analysis based on ORF5 showed that the Guangxi isolates were divided into two groups. Most of these were closely related to highly pathogenic strains, showing a 30 amino acid deletion at positions 481 and 533-561 of Nsp2, but an additional unique isolate (GXNN06) possessed a further four amino acid deletion at positions 485-488 of Nsp2.

Evaluation and analysis of dengue virus enhancing and neutralizing activities using simple high-throughput assays.

The risk of antibody-dependent enhancement (ADE) of dengue virus (DENV) infection is a major obstacle for the development of dengue vaccine candidates. Here, we described a novel approach for assessment of ADE by measuring DENV nonstructural protein 1 (NS1) production in culture supernatants with Fcγ receptor-expressing K562 cells in ELISA format (ELISA-ADE). Enhancing activities quantified by measurement of kinetics of NS1 production were in a good agreement with the results of the virus titration assay. In conjunction with the previously established enzyme-linked immunospot-based micro-neutralization test (ELISPOT-MNT) in 96-well format, the observable dose-response profiles of enhancing and neutralizing activities against all four DENV serotypes were produced with two flaviviral envelope cross-reactive monoclonal antibodies and four primary DENV-1-infected human sera. The simple high-throughput ELISA-ADE assay offers advantages for quantitative measurement of infection enhancement that can potentially be applied to large-scale seroepidemiological studies of DENV infection and vaccination.

[Visual system and prey capture behavior of larval zebrafish].

Studying neural circuits is a crucial step for understanding neural mechanisms underlying animal behaviors. Larval zebrafish is a low vertebrate animal model with incomparable advantages in neural circuit study. In this review, we describe the zebrafish visual system and its downstream targets, with special emphasis on their possible roles in prey capture behavior. Prey capture is executed mainly through the visual system and its downstream circuits, including reticulospinal commanding neurons, motor-controlling circuits within the spinal cord, and other un-identified functional units. With the development of approaches in monitoring and manipulating neuronal activity and behavioral assays, we will get deep insights about neural basis for prey capture in near future, which will shed light on elucidating neural circuit mechanisms of behavior.