Structural and Functional Insights into Host Death Domains Inactivation by the Bacterial Arginine GlcNAcyltransferase Effector.

Enteropathogenic E. coli NleB and related type III effectors catalyze arginine GlcNAcylation of death domain (DD) proteins to block host defense, but the underlying mechanism is unknown. Here we solve crystal structures of NleB alone and in complex with FADD-DD, UDP, and Mn2+ as well as NleB-GlcNAcylated DDs of TRADD and RIPK1. NleB adopts a GT-A fold with a unique helix-pair insertion to hold FADD-DD; the interface contacts explain the selectivity of NleB for certain DDs. The acceptor arginine is fixed into a cleft, in which Glu253 serves as a base to activate the guanidinium. Analyses of the enzyme-substrate complex and the product structures reveal an inverting sugar-transfer reaction and a detailed catalytic mechanism. These structural insights are validated by mutagenesis analyses of NleB-mediated GlcNAcylation in vitro and its function in mouse infection. Our study builds a structural framework for understanding of NleB-catalyzed arginine GlcNAcylation of host death domain.

Heteromultivalent DNA Enhances the Assembly Yield of Hybrid Nanoparticles and Facilitates Dynamic Disassembly for Bioanalysis Using ICP-MS.

To obtain enhanced physical and biological properties, various nanoparticles are typically assembled into hybrid nanoparticles through the binding of multiple homologous DNA strands to their complementary counterparts, commonly referred to as homomultivalent assembly. However, the poor binding affinity and limited controllability of homomultivalent disassembly restrict the assembly yield and dynamic functionality of the hybrid nanoparticles. To achieve a higher binding affinity and flexible assembly choice, we utilized the paired heteromultivalency DNA to construct hybrid nanoparticles and demonstrate their excellent assembly characteristics and dynamic applications. Specifically, through heteromultivalency, DNA-functionalized magnetic beads (MBs) and gold nanoparticles (AuNPs) were efficiently assembled. By utilizing ICP-MS, the assembly efficiency of AuNPs on MBs was directly monitored, enabling quantitative analysis and optimization of heteromultivalent binding events. As a result, the enhanced assembly yield is primarily attributed to the fact that heteromultivalency allows for the maximization of effective DNA probes on the surface of nanoparticles, eliminating steric hindrance interference. Subsequently, with external oligonucleotides as triggers, it was revealed that the disassembly mechanism of hybrid nanoparticles was initiated, which was based on an increased local concentration rather than toehold-mediated displacement of paired heteromultivalency DNA probes. Capitalizing on these features, an output platform was then established based on ICP-MS signals that several Boolean operations and analytical applications can be achieved by simply modifying the design sequences. The findings provide new insights into DNA biointerface interaction, with potential applications to complex logic operations and the construction of large DNA nanostructures.

Protein-Controlled Split DNAzyme to Enhance Catalytic Activity: Design and Performance.

In this study, we utilized proteins to control the assembly of split DNAzyme to establish protein-controlled split DNAzymes (Pc SD), with the aim of enhancing its catalytic activity. To achieve this, simultaneous recognition of protein by affinity ligands at both ends of split DNAzyme fragments induced an increased local concentration of each split fragment, leading to reassembly of the split catalytic core with a rigid conformation and higher affinity to its cofactor. As a result, under protein control, Pc SD exhibits unexpected cleavage efficiency compared to free split DNAzyme. To further explore the catalytic features, we then systematically positioned split sites within the catalytic core of three popular DNAzyme-based Pc SDs, thus revealing the important nucleic acids that influence Pc SDs activity. Based on the excellent analytical performance of Pc SD for streptavidin (with a LOD of 0.1 pM in buffer),we equipped Pc SD with antibodies as rapid diagnostic tools for inpatient care (AFP as biomarker) with a minimized workflow (with a LOD of 2 pM in 5% human serum). The results of this study offer fundamental insights into external factors for boosting DNAzyme catalysis and will be promising for applications that utilize split DNAzymes.

Involvement of B-aat1 and Cbs in regulating mantle pigmentation in the Pacific oyster (Crassostrea gigas).

BACKGROUND: Shell color formation is an important physiological process in bivalves, the molecular genetic basis has potential application in bivalve aquaculture, but there is still remaining unclear about this issue. The cystine/glutamate transporter (Slc7a11) and cystathionine beta-synthase (Cbs) are integral genes in pheomelanin synthesis pathway, which is vital to skin pigmentation. METHODS AND RESULTS: Here, the sequences of b (0, +) -type amino acid transporter 1 (B-aat1) and Cbs in Pacific oyster (Crassostrea gigas) (CgB-aat1, CgCbs) were characterized. Phylogenetically, the deduced amino acid sequences of CgB-aat1 and CgCbs both possessed conserved features. Genes were both ubiquitously expressed in six tested tissues with more abundant expression level in central mantle. Besides, the polyclonal antibodies of CgB-aat1, CgCbs, CgTyr, and CgTyrp2 were successfully prepared. Immunofluorescence analysis revealed that CgB-aat1 and CgCbs proteins were both expressed in gill rudiments of eyed-larvae and concentrated mainly in cytoplasm of epithelial cell and nerve axons in mantle. Additionally, after CgB-aat1 or CgCbs silencing, expressions at mRNA and protein levels of CgB-aat1 and CgCbs involved in pheomelanin synthesis were significantly suppressed, and CgTyr, CgTyrp1 and CgTyrp2 related to eumelanin synthesis were also down-regulated but no apparent differences, respectively. Moreover, micrographic examination found less brown-granules at mantle edge in CgB-aat1 interference group. CONCLUSION: These results implied that pheomelanin synthesis was possible induced by CgB-aat1-CgTyr-CgCbs axis, and it played an essential role on mantle pigmentation in the oysters. These findings provide the useful genetic knowledge and enrich the physiological information for the shell color formation in bivalve aquaculture.

Lanthanide Encoded Logically Gated Micromachine for Simultaneous Detection of Nucleic Acids and Proteins by Elemental Mass Spectrometry.

DNA-based logic computing potentially for analysis of biomarker inputs and generation of oligonucleotide signal outputs is of great interest to scientists in diverse areas. However, its practical use for sensing of multiple biomarkers is limited by the universality and robustness. Based on a proximity assay, a lanthanide encoded logically gated micromachine (LGM-Ln) was constructed in this work, which is capable of responding to multiplex inputs in biological matrices. Under the logic function controls triggered by inputs and a Boolean "AND" algorithm, it is followed by an amplified "ON" signal to indicate the analytes (inputs). In this logically gated sensing system, the whole computational process does not involve strand displacement in an intermolecular reaction, and a threshold-free design is employed to generate the 0 and 1 computation via intraparticle cleavage, which facilitates the computation units and makes the "computed values" more reliable. By simply altering the affinity ligands for inputs' biorecognition, LGM-Ln can also be extended to multi-inputs mode and produce the robust lanthanide encoded outputs in the whole human serum for sensing nucleic acids (with the detection limit of 10 pM) and proteins (with the detection limit of 20 pM). Compared with a logically gated micromachine encoded with fluorophores, the LGM-Ln has higher resolution and no spectral overlaps for multiple inputs, thus holding great promise in multiplex analyses and clinical diagnosis.

Differential distribution and genetic determination of eccrine sweat glands and hair follicles in the volar skin of C57BL/6 mice and SD rats.

BACKGROUND: Eccrine sweat glands (ESGs) and hair follicles (HFs) are the prominent skin appendages regulating human body temperature. C57BL/6 mice and Sprague-Dawley (SD) rats are the most commonly used model animals for studying ESGs and HFs. Previous studies have shown the distribution of ESGs and HFs in volar hindfeet of C57BL/6 mice, but there are few or no reports on the distribution of ESGs and HFs in volar forefeet of C57BL/6 mice and volar feet of SD rats. Here, we investigated the differential distribution and genetic determination of ESGs and HFs in the volar skin of C57BL/6 mice and SD rats through gross observation, iodine-starch sweat test, double staining with Nile Blue A and Oil Red O, hematoxylin and eosin (HE) staining, double immunofluorescence staining of LIM Homeobox 2 (LHX2)/Na+-K+-ATPase α1(NKA) or LHX2/Na+-K+-2Cl－ cotransporter 1 (NKCC1), and qRT-PCR detection of ESG-related gene Engrailed 1 (En1) and HF-related gene LHX2. RESULTS: The results showed ESGs but no HFs in the footpads of C57BL/6 mice and SD rats, both ESGs and HFs in the inter-footpads (IFPs) of C57BL/6 mice, and neither ESGs nor HFs in the IFPs of SD rats. The relative quantitative change in En1 was consistent with the differential distribution of ESGs, and the relative quantitative change of LHX2 was consistent with the differential distribution of HFs. CONCLUSION: C57BL/6 mice and SD rats had their own characteristics in the distribution of ESGs and HFs in the volar skin, and researchers should choose mice or rats, and even forefeet or hindfeet as their research object according to different purposes. The study provides a basis for selection of optimal animal models to study development, wound healing and regeneration of skin appendages.

A signal conversion system using binding-induced strand displacement for disease biomarker assay.

Using the principle of binding-induced DNA strand displacement (BINSD), a DNAzyme-powered nanomachine biosensor for multiple biomarkers via magnetic beads-based signal conversion was designed. This sensor can convert multiple biomarker recognition into release of predesigned output nucleic acids tagged with streptavidin proteins (SA-DNA) for activation of DNA nanomachines. In general, we adopted complementary base pairing rules and affinity ligand specific recognition, and three types of signal conversion systems were constructed that realized universal, sensitive, accurate, and specific detection of multiple biomarkers. Taking the advantage of the strong anti-interference capability of magnetic separation, this strategy could be used for detection of various biomarkers in clinical practice.

Serological survey of canine H3N2, pandemic H1N1/09, and human seasonal H3N2 influenza viruses in cats in northern China, 2010-2014.

BACKGROUND: The close contact between cats and humans poses a threat to public health because of the potential zoonotic transmission of influenza viruses to humans. Therefore, we examined the seroprevalence of pandemic H1N1/09, canine H3N2, and human H3N2 viruses in pet cats in northern China from 2010 to 2014. FINDING: Of 1794 serum samples, the seropositivity rates for H1N1/09, canine H3N2, and human H3N2 were 5.7%, 0.7%, and 0.4%, respectively. The seropositivity rate for H1N1/09 in cats was highest in 2010 (8.3%), and then declined continuously thereafter. Cats older than 10 years were most commonly seropositive for the H1N1/09 virus. CONCLUSIONS: Our findings emphasize the need for continuous surveillance of influenza viruses in cats in China.

Research on prevention and control technology of classified rockburst in TBM construction of deeply buried tunnels.

Rock blasting and other geological disasters occur frequently in the TBM construction of deeply buried tunnels and seriously threaten construction safety and progress. Therefore, it is extremely important to conduct scientific research for effective prevention and control of rockbursts in construction. Based on a large number of field rockburst data, this study analyses the influence of rockburst on construction safety and efficiency by using statistical theory and summarizes the temporal and spatial characteristics of rockburst time, location and influence range. Using these results, combined with the characteristics of the TBM structure and construction method, classification prevention and control objectives, theoretical criteria and prevention and control technology of rock bursts are proposed. A theoretical system of classified prevention and control of rockburst is constructed, which is cooperatively controlled by microseismic monitoring, TBM equipment, TBM excavation and support measures. The system is verified to provide practical protection, demonstrating that this report provides an important reference for the prevention and control of rock bursts in ultradeep tunnels.

Vibration prediction and analysis of the main beam of the TBM based on a multiple linear regression model.

The vibration of tunnel boring machine (TBM) is very difficult to monitor on sites, and related research on prediction methods is rare. Based on the field tunnelling test of a TBM in the Xinjiang Ehe project, the vibration information of the main beam of the TBM under different surrounding rock conditions is collected. The relationships among the tunnelling parameters, surrounding rock parameters and vibration parameters were studied. The results show that the penetration, cutter head speed, torque and thrust are important parameters affecting TBM vibration. In addition, the field penetration index and cutter head driving power index are significantly related to the root mean square of acceleration. Based on this, a multiple regression prediction model of TBM vibration is established. The model was verified and analysed via field projects, and the relative prediction error was less than 12%. This method can be used to predict the vibration of a TBM in real time through characteristic parameters without the use of a traditional monitoring system. This approach is highly important for determining the status of TBM equipment in real time.

An E3 ligase TRIM1 promotes colorectal cancer progression via K63-linked ubiquitination and activation of HIF1α.

Accumulating studies have shown that E3 ligases play crucial roles in regulating cellular biological processes and signaling pathways during carcinogenesis via ubiquitination. Tripartite-motif (TRIM) ubiquitin E3 ligases consist of over 70 members. However, the clinical significance and their contributions to tumorigenesis remain largely unknown. In this study, we analyzed the RNA-sequencing expression of TRIM E3 ligases in colorectal cancer (CRC) and identified 10 differentially expressed genes, among which TRIM1 expression predicted poor prognosis of CRC patients. We demonstrated that TRIM1 expression is positively associated with CRC pathological stages, and higher expression is positively correlated with infiltrating levels of immune cells and immunotherapy biomarkers. TRIM1 expression promotes the proliferation and migration of colorectal cancer cells in vitro and in vivo. Transcriptional analysis showed that TRIM1 is responsible for metabolism promotion and immune suppression. Mechanistically, we found that TRIM1 binds HIF1α and mediates its K63-linked ubiquitination, which is required for HIF1α nuclear translocation and subsequent activation. Ubiquitination occurs at Lys214 in the loop between the two PAS domains of HIF1α, and mutation of Lys214 severely disturbs the function of HIF1α. Besides, HIF1α ubiquitination enhances its binding with proteins involved in cellular trafficking and nucleocytoplasmic transport pathway. Collectively, our results indicate TRIM1's role in predicting prognosis and reveal how TRIM1 functions to upregulate HIF1α expression and promote tumor cell proliferation.

The impact of COVID-19 on small- and medium-sized enterprises (SMEs): empirical evidence for green economic implications.

Small- and medium-sized enterprises (SMEs) in China have been hit hard by the coronavirus (COVID-19) outbreak, which has jeopardized their going out of business altogether. As a result, this research will shed light on the long-term impacts of COVID-19 lockdown on small businesses worldwide. The information was gathered through a survey questionnaire that 313 people completed. Analyzing the model was accomplished through the use of SEM in this investigation. Management and staff at SMEs worldwide provided the study's data sources. Research shows that COVID-19 has a significantly bad influence on profitability, operational, economic, and access to finance. In the study's findings, outside funding aids have played an important role in SMEs' skill to persist and succeed through technological novelty than in their real output. SME businesses, administrations, and policymakers need to understand the implications of this study's results.

Assessing the impact of green finance and urbanization on the tourism industry-an empirical study in China.

There is a dearth of empirical studies looking at the link between green economic development and tourism in quantifiable terms. Using panel data from China's 30 provinces from 2005 to 2018, this study investigates the impact of green finance on China's tourism industry. Using renewable energy, income per capita, carbon emissions, and urbanizations as explanatory factors is also utilized. According to estimation, the findings reveal that green finance substantially impacts the tourism business. This positive effect is more pronounced in provinces where economic and social conditions are better, thus boosting the region's tourism industry. The same holds for income per capita, renewable energy, and environmental factors. In addition, urbanization has a negligible effect on the variable being studied. A further way to boost the growth of tourism is through the use of green finance. The empirical findings can benefit China's green financial planning and environmental sustainability.

Natural and experimental infection of dogs with pandemic H1N1/2009 influenza virus.

Evidence of H1N1/2009 influenza virus infection was identified in two domestic dogs in China in November 2009. Virus isolation and sequence analysis of all eight genes of the two isolates showed that they were related closely to the H1N1/2009 influenza virus circulating in humans, indicating that they were probably acquired from humans. To determine the pathogenicity and transmissibility of H1N1/2009 influenza virus in dogs, experimental infection and transmission were performed. Inoculated dogs were able to shed virus in nasal secretions, but symptoms were very mild. Uninoculated dogs were co-mingled to determine the transmissibility of the isolate, and one of three exposed dogs was shown to develop infection. The present findings indicate that human H1N1/2009 can infect dogs, but is transmitted inefficiently between dogs.

[Influence of soysaponins on blood lipid and grume of rats].

OBJECTIVE: To study the influence of soysaponins on blood lipid and grume of the rats. METHODS: According to their levels of cholesterol in serum and weight, 48 SD healthy male rats were randomly divided into groups, normal control, high fat control, high fat with 10 mg/kg aspirin, high fat with soyasaponins (20, 40 and 80 mg/kg). 10 weeks after gastric lavage, determined total cholesterol (TC), triglyceride (TG), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C) and grume indices. RESULTS: As compared to high fat control, soyasaponins significantly reduced the serum TC (high fat control 2.19, soyasaponins group 1.86, 1.85 and 1.72 mmol/L), TG and LDL-C concentrations, increased the HDL-C levels distinctly. Compared with model group, aspirin group, soyasaponins group of activated partial thromboplastin time (high fat control 60.50s, aspirin group 68.10s, soyasaponins group 66.75s, 67.33s and 67.67s), prothrombin time (high fat control 13.15s, aspirin group 18.00s, soyasaponins group 17.00, 17.43 and 18.43s) higher than the model group, plasma fibrinogen decreased (high fat control 2.51 g/L, aspirin group 2.18g/L, soyasaponins group 2.29, 2.25 and 2.10 g/L). CONCLUSION: It demonstrated that the soysaponins could adjust blood fat, reduce whole blood viscosity and improve blood viscosity. It is favorable to prevent cardiovascular and cerebrovascular diseases.

Assessing the Role of Green Finance and Education as New Determinants to Mitigate Energy Poverty.

Energy poverty (EP) is a problem that affects developed and developing economies, and its mitigation is of great significance to social welfare. EP affects Latin American countries, and policymakers have recently attempted to address this issue, particularly in the aftermath of the recent economic crisis. It is essential to measure and evaluate EP to implement strategies and policies effectively. Using a panel quantile regression approach, we investigate the heterogeneous impact of green finance, renewable energy (RE), and energy efficiency (EE) on EP for 33 Latin American countries from 2000 to 2018. Furthermore, certain associated control variables are incorporated into our model to avoid an omitted variable bias. According to empirical results, the impact of independent variables on EP is heterogeneous. Specifically, green finance is an essential source of alleviating EP, and it has a significant positive effect across all quantiles, but it is especially strong in the middle quantiles. RE and EE significantly mitigate EP, with the strongest effects occurring at higher quantiles. By including green finance, RE, and EE as the main explanatory determinants of EP, the findings urge policymakers in Latin American countries to design a comprehensive energy conservation policy to minimize the effects of massive EP.

Monitoring nucleic acid amplification process using a UiO-66-NH2-based fluorescent sensor.

Herein, we developed a nucleic acid amplification process monitoring scheme by the use of UiO-66-NH2, in which pyrophosphate ion (PPi) released from the amplification can competitively coordinate with Zr to weaken the ligand-to-metal charge transfer and cause fluorescence recovery, thus reflecting the amplification process. This is the first attempt at using a MOF for monitoring the nucleic acid amplification process.

Biomolecule-guided co-localization of intermolecular G-rich strands for the construction of a tetramolecular G-quadruplex sensing strategy.

We herein introduce the principle of proximity assay into tetramolecular G-quadruplexes guided by various biomolecules for the construction of a sensing strategy. Our strategy is based on the co-localization of intermolecular G-rich strands guided by a recognition event of a specific biomolecule to its corresponding affinity ligand. In such case, the local concentration among intermolecular strands is significantly increased to trigger the following self-assembly that served as the peroxidase-mimicking activity. This strategy is versatile, homogenous and adaptable to different types of biomolecules.

Electroshock synthesis of a bifunctional nonprecious multi-element alloy for alkaline hydrogen oxidation and evolution.

The design and production of active, durable, and nonprecious electrocatalysts toward alkaline hydrogen oxidation and evolution reactions (HOR/HER) are extremely appealing for the implementation of hydrogen economy, but remain challenging. Here, we report a facile electric shock synthesis of an efficient, stable, and inexpensive NiCoCuMoW multi-element alloy on Ni foam (NiCoCuMoW) as a bifunctional electrocatalyst for both HOR and HER. For the HOR, the current density of NiCoCuMoW could reach ∼11.2 mA cm-2 when the overpotential is 100 mV, higher than that for commercial Pt/C (∼7.2 mA cm-2) and control alloy samples with less elements, along with superior CO tolerance. Moreover, for the HER, the overpotential at 10 mA cm-2 for NiCoCuMoW is only 21 mV, along with a Tafel slope of low to 63.7 mV dec-1, rivaling the commercial Pt/C as well (35 mV and 109.7 mV dec-1). Density functional theory calculations indicate that alloying Ni, Co, Cu, Mo, and W can tune the electronic structure of individual metals and provide multiple active sites to optimize the hydrogen and hydroxyl intermediates adsorption, collaboratively resulting in enhanced electrocatalytic activity.

Autophagy, not apoptosis, plays a role in lumen formation of eccrine gland organoids.

BACKGROUND: Sweat secreted by eccrine sweat glands is transported to the skin surface through the lumen. The eccrine sweat gland develops from the initial solid bud to the final gland structure with a lumen, but how the lumen is formed and the mechanism of lumen formation have not yet been fully elucidated. This study aimed to investigate the mechanism of lumen formation of eccrine gland organoids (EGOs). METHODS: Human eccrine sweat glands were isolated from the skin for tissue culture, and the primary cultured cells were collected and cultured in Matrigel for 14 days in vitro. EGOs at different development days were collected for hematoxylin and eosin (H&E) staining to observe morphological changes and for immunofluorescence staining of proliferation marker Ki67, cellular motility marker filamentous actin (F-actin), and autophagy marker LC3B. Western blotting was used to detect the expression of Ki67, F-actin, and LC3B. Moreover, apoptosis was detected using a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis assay kit, and the expression of poly (ADP-ribose) polymerase and Caspase-3 was detected by Western blot. In addition, 3-methyladenine (3MA) was used as an autophagy inhibitor to detect whether the formation of sweat glands can be effectively inhibited. RESULTS: The results showed that a single gland cell proliferated rapidly and formed EGOs on day 4. The earliest lumen formation was observed on day 6. From day 8 to day 14, the rate of lumen formation in EGOs increased significantly. The immunofluorescence and Western blot analyses showed that the expression of Ki67 gradually decreased with the increase in days, while the F-actin expression level did not change. Notably, the expression of autophagy marker LC3B was detected in the interior cells of EGOs as the apoptosis signal of EGOs was negative. Compared with the control group, the autophagy inhibitor 3MA can effectively limit the formation rate of the lumen and reduce the inner diameter of EGOs. CONCLUSION: Using our model of eccrine gland 3D-reconstruction in Matrigel, we determined that autophagy rather than apoptosis plays a role in the lumen formation of EGOs.