PREX2 contributes to radiation resistance by inhibiting radiotherapy-induced tumor immunogenicity via cGAS/STING/IFNs pathway in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) lacks established biomarkers or molecular targets for predicting or enhancing radiation response. Phosphatidylinositol-3,4,5-triphosphate-dependent Rac exchange factor 2 (PREX2) exhibits intricate implications in tumorigenesis and progression. Nevertheless, the precise role and underlying mechanisms of PREX2 in CRC radioresistance remain unclear. METHODS: RNA-seq was employed to identify differentially expressed genes between radioresistant CRC cell lines and their parental counterparts. PREX2 expression was scrutinized using Western blotting, real-time PCR, and immunohistochemistry. The radioresistant role of PREX2 was assessed through in vitro colony formation assay, apoptosis assay, comet assay, and in vivo xenograft tumor models. The mechanism of PREX2 was elucidated using RNA-seq and Western blotting. Finally, a PREX2 small-molecule inhibitor, designated PREX-in1, was utilized to enhance the efficacy of ionizing radiation (IR) therapy in CRC mouse models. RESULTS: PREX2 emerged as the most significantly upregulated gene in radioresistant CRC cells. It augmented the radioresistant capacity of CRC cells and demonstrated potential as a marker for predicting radioresistance efficacy. Mechanistically, PREX2 facilitated DNA repair by upregulating DNA-PKcs, suppressing radiation-induced immunogenic cell death, and impeding CD8+ T cell infiltration through the cGAS/STING/IFNs pathway. In vivo, the blockade of PREX2 heightened the efficacy of IR therapy. CONCLUSIONS: PREX2 assumes a pivotal role in CRC radiation resistance by inhibiting the cGAS/STING/IFNs pathway, presenting itself as a potential radioresistant biomarker and therapeutic target for effectively overcoming radioresistance in CRC.

The Short-Term Efficacy of Bifidobacterium Quadruple Viable Tablet in Patients With Diarrhea-Predominant Irritable Bowel Syndrome: Potentially Mediated by Metabolism Rather Than Diversity Regulation.

INTRODUCTION: The therapeutic effect of probiotics for irritable bowel syndrome (IBS) was controversial. This study aims to evaluate the short-term efficacy of Bifidobacterium quadruple viable tablet in patients with diarrhea-predominant IBS and explore factors associated with response to probiotics. METHODS: A randomized, double-blind, placebo-controlled, multicenter trial was performed in 15 hospitals. A total of 290 patients who fulfilled the eligibility criteria were assigned to the probiotics or placebo group randomly with a ratio of 1:1 for a 4-week treatment and a 2-week follow-up. The primary outcome was the response rate. It was regarded as the proportion of patients with composite responses of improvement in both abdominal pain and diarrhea simultaneously. RESULTS: After 4-week continuous administration, the response rates of the probiotics and the placebo were 67.59% and 36.55%, respectively ( P < 0.001). In the probiotics, those with higher abdominal pain scores (2.674 [1.139-6.279]) were more likely to respond, but responders in placebo had lower Hamilton Depression Scale score (0.162 [0.060-0.439]), lower Hamilton Anxiety Scale score (0.335 [0.148-0.755]), and higher degree of bloating (2.718 [1.217-6.074]). Although the diversity of the microbiota was not significantly changed by probiotics, the abundance of bacteria producing short-chain fatty acids (SCFAs), including Butyricimonas ( P = 0.048), Pseudobutyrivibrio ( P = 0.005), Barnesiella ( P = 0.020), and Sutterella ( P = 0.020), and the concentration of SCFAs including butyric acid ( P = 0.010), valeric acid ( P = 0.019), and caproic acid ( P = 0.046) in feces increased. DISCUSSION: A Bifidobacterium quadruple viable tablet had a significant short-term efficacy for the treatment of diarrhea-predominant IBS and was more effective in patients with higher abdominal pain scores. This kind of probiotics could improve the abundance of several bacteria producing SCFAs and the concentration of fecal SCFAs compared with placebos.

Occurrence, sources, and risk assessment of pyrethroid insecticides in surface water and tap water from Taihu Lake, China.

Pyrethroid insecticides are one of the most widely used insecticides globally, posing a severe threat to human health and the environment. In this study, we applied high-throughput organic analysis testing combined with high-volume solid-phase extraction (Hi-throat/Hi-volume SPE) to elucidate the occurrence of 11 pyrethroid insecticides in lake water (n = 37), tributary river water (n = 15), and tap water (n = 6) in the Taihu Lake Basin. Permethrin was found to be the major contributing pyrethroid insecticide (detection rate = 100%). The concentrations of pyrethroid insecticides from different lake regions were revealed in the following descending order: southern > eastern > western > northern. The principal component analysis and multiple linear regression demonstrated that landscape maintenance, agricultural cultivation, and livestock breeding were the main sources of pyrethroid insecticides in the Taihu Lake surface water. Moreover, runoff input plays an important role in their accumulation, while the surrounding rivers contribute 2292 kg of pyrethroid insecticides to Taihu Lake annually. The risk assessment analysis demonstrated that pyrethroid insecticides pose a high risk to both the ecological environment and the surrounding human populations, thereby necessitating effective countermeasures. Furthermore, the pyrethroid insecticides in the Yangtze River Delta region have to be controlled. Overall, this is the first study focused on China that revealed the residue levels in water sources and tap water.

Primary Ovarian Small Cell Carcinoma of Pulmonary Type: Analysis of 6 Cases and Review of 31 Cases in the Literatures.

Objective Primary ovarian small cell carcinoma of pulmonary type (SCCOPT) is a rare ovarian tumor with a poor prognosis. The platinum-based chemotherapy is the standard treatment. However, there is little research on the clinical characteristics of SCCOPT and the potential benefits of other treatments due to its low incidence. The study aims to investigate clinicopathological characteristics and treatment of SCCOPT.Methods We summarized the clinical, imaging, laboratorical and pathological characteristics of 37 SCCOPT cases, in which 6 cases were admitted to the Gansu Provincial Hospital from the year of 2008 to 2022 and 31 cases reported in 17 English and 3 Chinese literatures.Results The median age of the studied SCCOPT cases (n=37) was 56.00 (range, 22-80) years. Almost 80% of them had a stage Ⅲ or Ⅳ tumor. All patients underwent an operation and postoperative chemotherapy. Nevertheless, all cases had a poor prognosis, with a median overall survival time of 12 months. Immunohistochemically, the SCCOPT of all patients showed positive expressions of epithelial markers, such as CD56 and sex-determining region of Y chromosome-related high-mobility-group box 2 (SOX-2), and negative expressions of estrogen receptor, progesterone receptor, vimentin, Leu-7, and somatostatin receptor 2. The tumor of above 80% cases expressed synaptophysin. Only a few cases expressed neuron-specific enolase, chromogranin A, and thyroid transcription factor-1. Conclusions SCCOPT had a poor prognosis. SOX-2 could be a biomarker to be used to diagnose SCCOPT.

Comprehensive Exposure Studies of Per- and Polyfluoroalkyl Substances in the General Population: Target, Nontarget Screening, and Toxicity Prediction.

Novel per- and polyfluoroalkyl substances (PFASs) in the environment and populations have received extensive attention; however, their distribution and potential toxic effects in the general population remain unclear. Here, a comprehensive study on PFAS screening was carried out in serum samples of 202 individuals from the general population in four cities in China. A total of 165 suspected PFASs were identified using target and nontarget analysis, including seven identified PFAS homolog series, of which 16 PFASs were validated against standards, and seven PFASs [4:2 chlorinated polyfluorinated ether sulfonate (4:2 Cl-PFESA), 7:2 chlorinated polyfluorinated ether sulfonate (7:2 Cl-PFESA), hydrosubstituted perfluoroheptanoate (H-PFHpA), chlorine-substituted perfluorooctanoate (Cl-PFOA), chlorine-substituted perfluorononanate (Cl-PFNA), chlorine-substituted perfluorodecanoate (Cl-PFDA), and perfluorodecanedioic acid (PFLDCA n = 8)] were reported for the first time in human serum. The Tox21-GCN model (a graph convolutional neural network model based on the Tox21 database) was established to predict the toxicity of the discovered PFASs, revealing that PFASs containing sulfonic acid groups exhibited multiple potential toxic effects, such as estrogenic effects and stress responses. Our study indicated that the general population was exposed to various PFASs, and the toxicity prediction results of individual PFASs suggested potential health risks that could not be ignored.

Efficacy of keverprazan for duodenal ulcer: A phase II randomized, double-blind, parallel-controlled trial.

BACKGROUND AND AIM: Considering the limitation of varying acid suppression of proton pump inhibitors, this study was aimed to assess the efficacy, safety, and dose-effect relationship of keverprazan, a novel potassium-competitive acid blocker, in the treatment of duodenal ulcer (DU) compared with lansoprazole. METHODS: A randomized, double-blind, double-dummy, multicenter, low-dose, high-dose, and positive-drug parallel-controlled study was conducted to verify the non-inferiority of keverprazan (20 or 30 mg) to lansoprazole of 30 mg once daily for 4 to 6 weeks and dose-effect relationship of keverprazan in the treatment of patients with active DU confirmed by endoscopy. RESULTS: Of the 180 subjects randomized, including 55 cases in the keverprazan_20 mg group, 61 cases in the keverprazan_30 mg group, and 64 cases in the lansoprazole_30 mg group, 168 subjects (93.33%) completed the study. The proportions of healed DU subjects in the keverprazan_20 mg, keverprazan_30 mg, and lansoprazole_30 mg groups were respectively 87.27%, 90.16%, and 79.69% at week 4 (P = 0.4595) and were respectively 96.36%, 98.36%, and 92.19% at week 6 (P = 0.2577). The incidence of adverse events in the keverprazan_20 mg group was lower than that in the lansoprazole_30 mg (P = 0.0285) and keverprazan_30 mg groups (P = 0.0398). CONCLUSIONS: Keverprazan was effective and non-inferior to lansoprazole in healing DU. Based on the comparable efficacy and safety data, keverprazan of 20 mg once daily is recommended for the follow-up study of acid-related disorders. (Trial registration number: ChiCTR2100043455.).

The surface reconstruction induced enhancement of the oxygen evolution reaction on α-SnWO4 (010) based on a density functional theory study.

The coordination environment of photocatalytic active sites is determined by the type of surface termination on an α-SnWO4 semiconductor. However, the stability of these surface terminations has not been thoroughly explored. In this work, the stability of the α-SnWO4(010) surface termination was studied using a thermodynamic analysis based on density functional theory (DFT). Under appropriate thermodynamic equilibrium conditions, it is possible to stabilize the O-W, O-Sn, R-OOSn and ST3 terminations of the α-SnWO4(010) surface. The electronic structures of these three potential stable surface terminations are also calculated using a Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional to determine the conceivable bandgap values. It is found that there are numerous surface states in the bandgap of these terminations. This is due to the evident reconstruction of these terminations after geometry optimization. In addition, work functions are substantially different for possible surface terminations. The results suggest that Z-scheme heterostructures based on SnWO4 can be regulated by securing the thermodynamically favorable surface terminations under suitable physical/chemical conditions. At last, O-Sn termination exhibits a low overpotential value of 0.51 V, showing remarkable oxygen evolution reaction (OER) performance among all stable surface terminations considered in this work. Our study may help explore the intrinsic surface properties of SnWO4, which will be a viable strategy for developing SnWO4-based photocatalysts.

Application of Hi-throat/Hi-volume SPE technique in assessing organophosphorus pesticides and their degradation products in surface water from Tai Lake, east China.

Organophosphorus pesticides (OPPs) are among the most commonly used pesticides worldwide. However, these compounds pose a serious threat to aquatic environments. Here, thirty-seven pesticides and eight degradation products were determined in surface water samples from Tai Lake, East China, using a high-volume solid phase extraction technique (Hi-throat/Hi-volume SPE). Surface water was pumped in-situ through a portable sampler, and OPPs in the water retained on the Hi-volume SPE adsorption column, finally extracted for analysis. This technique efficiently reduced the detection limits to below 0.3 ng/L. In total, 40 out of 45 OPP congeners were detected, which far exceeded the amount of OPPs in previous studies. The total concentration of OPPs ranged between 101.4 and 1530 ng/L (median: 378.9 ng/L). Parathion exhibited the highest concentration (median: 112.0 ng/L), followed by paraoxon-methyl (median: 90.3 ng/L), as well as carbophenothion, fenthion, and mevinphos. Agricultural areas were more polluted than residential and industrial regions. However, degradation products persisted in residential and industrial waters. The ecological risks of OPPs in these areas were estimated based on the risk quotient index (RQ). Parathion, fenthion, carbophenothion, and tolclofos-methyl occurred at high-risk levels, and the levels of degradation products were also non-trivial. Our findings thus indicated that OPP degradation products pose a potential threat to natural environments and should therefore be closely monitored.

Dual Role of Wnt5a in the Progression of Inflammatory Diseases.

Wnt5a is a secreted Wnt ligand that plays a critical role in cellular pathways and inflammatory diseases. The WNT5A gene encodes two protein isoforms, Wnt5a-long and Wnt5a-short, which differ based on different promoter methylation and have distinct functions. However, the mechanisms of the promoter methylation are unclear. Depending on the extent of promoter methylation, Wnt5a exerts both anti-inflammatory and pro-inflammatory effects in inflammatory diseases, which may be involved in different Wnt5a isoforms. Therefore, the Wnt5a isoforms may be potential diagnostic markers for inflammatory diseases and the mechanisms of the WNT5A gene promoter methylation need to be further investigated.

Application of surfactants in papermaking industry and future development trend of green surfactants.

In this work, the application of chemical surfactants, including cooking aids, detergents, surface sizing agents, and deinking agents as core components, is introduced in the wet end of pulping and papermaking. This method for the combined application of enzymes and surfactants has expanded, promoting technological updates and improving the effect of surfactants in practical applications. Finally, the potential substitution of green surfactants for chemical surfactants is discussed. The source, classification, and natural functions of green surfactants are introduced, including plant extracts, biobased surfactants, fermentation products, and woody biomass. These green surfactants have advantages over their chemically synthesized counterparts, such as their low toxicity and biodegradability. This article reviews the latest developments in the application of surfactants in different paper industry processes and extends the methods of use. Additionally, the application potential of green surfactants in the field of papermaking is discussed. KEY POINTS: • Surfactants as important chemical additives in papermaking process are reviewed. • Deinking technologies by combined of surfactants and enzymes are reviewed. • Applications of green surfactant in papermaking industry are prospected.

Research progress and the biotechnological applications of multienzyme complex.

The multienzyme complex system has become a research focus in synthetic biology due to its highly efficient overall catalytic ability and has been applied to various fields. Multienzyme complexes are formed by cascading complexes, which are multiple functionally related enzymes that continuously and efficiently catalyze the production of substrates. Compared with current mainstream microbial cell catalytic systems, in vitro multienzyme molecular machines have many advantages, such as fewer side reactions, a high product yield, a fast reaction speed, easy product separation, a tolerable toxic environment, and robust system operability, showing increasing competitiveness in the field of biomanufacturing. In this review, the research progress of multienzyme complexes in nature and multienzyme cascades in vivo or in vitro will be introduced, and the discovered enzyme cascades concerning scaffolding proteins will also be discussed. This review is expected to provide a more theoretical basis for the modification of multienzyme complexes and broaden their application in the field of synthetic biology. KEY POINTS: • The cascade reactions of some natural multienzyme complexes are reviewed. • The main approaches of constructing artificial multienzyme complexes are summarized. • The structure and application of cellulosomes are discussed and prospected.

Effects of a psychological nursing intervention on prevention of anxiety and depression in the postpartum period: a randomized controlled trial.

BACKGROUND: Anxiety and postpartum depression are the most common psychological problems in women after delivery. Cognitive behavior intervention has been reported to have an effect in the therapy of postpartum depression. This research aimed to investigate whether cognitive behavior intervention could prevent the pathogenesis of postpartum depression in primiparous women. METHODS: In this randomized controlled trial, primiparous women who were prone to postpartum depression were recruited. Participates in the control group received routine postpartum care and those in the intervention group received both routine postpartum care and cognitive behavior intervention. Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), Edinburgh Postpartum Depression Scale (EPDS) and Pittsburgh Sleep Quality Index (PSQI) were evaluated before and after the intervention. RESULTS: In the intervention group, the post-intervention scores of HAMA, HAMD, EPDS and PSQI were all significantly lower than the baseline scores (p = 0.034, p = 0.038, p = 0.004, p = 0.014, respectively). The proportion of participants with postpartum depression in the intervention group (11.5%) was significantly lower than the control group (24.3%) after the 6-week intervention. Participants in the intervention group were significantly more satisfied with the care than those in the control group (p = 0.032). CONCLUSION: This research provided evidence that cognitive behavioral intervention in postpartum period could alleviate anxiety and depression in primiparous women, and inhibit the pathogenesis of postpartum depression. Trial registry This clinical trial was registered in the Chinese Clinical Trial Registry (ChiCTR2000040076).

Biocatalytic production of 2,5-furandicarboxylic acid: recent advances and future perspectives.

2,5-Furandicarboxylic acid (FDCA) is attracting increasing attention because of its potential applications as a sustainable substitute to petroleum-derived terephthalic acid for the production of bio-based polymers, such as poly(ethylene 2,5-furandicarboxylate) (PEF). Many catalytic methods have been developed for the synthesis of FDCA, including chemocatalysis, biocatalysis, photocatalysis, and electrocatalysis. Biocatalysis is a promising approach with advantages that include mild reaction condition, lower cost, higher selectivity, and environment amity. However, the biocatalytic production of FDCA has hardly been reviewed. To fully understand the current research developments, this review comprehensively considers the research progress on toxic effects and biodegradation of furan aldehydes, and then summarizes the latest achievements concerning the synthesis of FDCA from 5-hydroxymethylfurfural and other chemicals, such as 2-furoic acid and 5-methoxymethylfurfural. Our primary focus is on biocatalytic methods, including enzymatic catalysis (in vitro) and whole-cell catalysis (in vivo). Furthermore, future research directions and general developmental trends for more efficient biocatalytic production of FDCA are also proposed.

Progress in research and application development of surface display technology using Bacillus subtilis spores.

Bacillus subtilis is a widely distributed aerobic Gram-positive species of bacteria. As a tool in the lab, it has the advantages of nonpathogenicity and limited likelihood of becoming drug resistant. It is a probiotic strain that can be directly used in humans and animals. It can be induced to produce spores under nutrient deficiency or other adverse conditions. B. subtilis spores have unique physical, chemical, and biochemical characteristics. Expression of heterologous antigens or proteins on the surface of B. subtilis spores has been successfully performed for over a decade. As an update and supplement to previously published research, this paper reviews the latest research on spore surface display technology using B. subtilis. We have mainly focused on the regulation of spore coat protein expression, display and application of exogenous proteins, and identification of developing research areas of spore surface display technology.

Clinical Characteristics and Risk Factors in Coronavirus Disease 2019 Patients with Liver Injury.

BACKGROUND Emerging studies noted that liver injury in coronavirus disease 2019 (COVID-19) patients may be induced by virus-mediated inflammation, which was confirmed by liver pathology. The aim of this study was to observe clinical characteristics and explore risk factors in COVID-19 patients with liver injury. MATERIAL AND METHODS In this retrospective study, 40 confirmed COVID-19 patients with normal alanine transaminase (ALT) on admission were divided into a group of normal ALT patients whose ALT was always less than 40 U/l during hospitalization and a group of elevated ALT patients whose ALT was at least once more than 40 U/l after admission. Clinical data, especially virus-induced inflammatory parameters, were analyzed for risk factors and predictive value. The Mann-Whitney U test and t test for comparing means and logistic regression were performed for analysis of risk factors. Area under the ROC curve was used for predictive values. RESULTS Sixteen of 40 (40.0%) patients developed elevated ALT, many of them with more severe COVID-19. The highest ALT level was 101 U/l. The risk factors for liver injury were C-reactive protein (CRP), interleukin 6 (IL6), erythrocyte sedimentation rate (ESR), CD8+T cell count, and severity of disease, and CRP (OR 1.13, 95% CI 1.045-1.222, p=0.002) was the independent risk factor. CONCLUSIONS Liver injury in COVID-19 patients was mild and associated with inflammatory markers, especially CRP, which suggests that liver injury may be induced by virus-mediated inflammation in COVID-19 patients.

Effects of Certain cis-Regulatory Elements on Stage-Specific vitellogenin Expression in the Bombyx mori (Lepidoptera: Bombycidae).

Bombyx mori vitellogenin (BmVg) is highly upregulated during pupation, and the 20-hydroxyecdysone and amino acids may regulate stage-specific BmVg expression. However, previous studies showed that other factors may also affect stage-specific BmVg expression. Here, we characterized effective BmVg transcription factors by identifying the corresponding cis-regulatory elements (CREs). We prepared transgenic B. mori, in which DsRed was driven by various lengths of BmVg promoter. qRT-PCR analysis showed that DsRed expression driven by a 1.0-kb BmVg promoter (VgP1.0K) was consistent with endogenous BmVg. VgP1.0K specificity was closer to the endogenous BmVg promoter than that of VgP0.8K. These results suggest that CREs affecting stage-specific BmVg expression were localized to the 1.0-kb BmVg promoter. We investigated the effects of certain CREs that could influence the stage specificity of BmVg promoter on BmVg expression in transgenic B. mori. The relative DsRed expression was significantly reduced in transgenic female B. mori and the peak in DsRed expression was delayed after E-box CRE mutation. These results demonstrate that the E-box element enhanced BmVg expression and also affected stage-specific BmVg expression. Moreover, the relative DsRed expression was significantly increased in transgenic female of B. mori after 3×BD CRE mutation in BmVg promoter. However, the stage specificity of the mutated promoter was consistent with that of the endogenous BmVg promoter. The 3×BD element downregulated BmVg but had no effect on stage-specific BmVg expression. The present study promoted the process of elucidating the regulatory network for stage-specific BmVg expression and furnished a theoretical basis for the application of BmVg promoter.

Genome-Wide Identification of CsATGs in Tea Plant and the Involvement of CsATG8e in Nitrogen Utilization.

Nitrogen (N) is a macroelement with an indispensable role in the growth and development of plants, and tea plant (Camellia sinensis) is an evergreen perennial woody species with young shoots for harvest. During senescence or upon N stress, autophagy has been shown to be induced in leaves, involving a variety of autophagy-related genes (ATGs), which have not been characterized in tea plant yet. In this study, a genome-wide survey in tea plant genome identified a total of 80 Camellia Sinensis autophagy-related genes, CsATGs. The expression of CsATG8s in the tea plant showed an obvious increase from S1 (stage 1) to S4 (stage 4), especially for CsATG8e. The expression levels of AtATGs (Arabidopsis thaliana) and genes involved in N transport and assimilation were greatly improved in CsATG8e-overexpressed Arabidopsis. Compared with wild type, the overexpression plants showed earlier bolting, an increase in amino N content, as well as a decrease in biomass and the levels of N, phosphorus and potassium. However, the N level was found significantly higher in APER (aerial part excluding rosette) in the overexpression plants relative to wild type. All these results demonstrated a convincing function of CsATG8e in N remobilization and plant development, indicating CsATG8e as a potential gene for modifying plant nutrient utilization.

Biomineralization of dentin.

A single biomineralization of demineralized dentin is significant to restore the demineralized dentin due to dental caries or erosion. In recent years, meaningful progress has been made regarding the mechanisms involved in the biomineralization of dentin collagen. Concepts changing from the classical ion-based crystallization to non-classical particle-based crystallization, inspired a different strategy to infiltrate the demineralized dentin collagen. The remarkable discovery was the report of liquid-like amorphous calcium phosphate as nanoprecursor particles to carbonated hydroxyapatite. The non-collagenous proteins and their analogues are widely investigated, for their key role in controlling mineralization during the process of crystal nucleation and growth. The in-depth studies of the gap zone provided significant improvements in our understanding of the structure of collagen and of the intrafibrillar remineralization of collagen fibrils. The collagen is not a passive substrate as previously supposed, and the active role of guiding nanoprecursor infiltration and mediating its nucleation has been demonstrated. Furthermore, recovery of mechanical properties has been evaluated to determine the effectiveness of dentin remineralization. Finally, the problems regarding the origin formation of the calcium phosphate that is deposited in the collagen, and the exact interactions between the non-collagenous proteins, amorphous calcium phosphate and collagen are still unclear. We reviewed the importance of these findings in enriching our understanding of dentin biomineralization, while addressing certain limitations that are inherent to in vitro studies.

Production of trehalose with trehalose synthase expressed and displayed on the surface of Bacillus subtilis spores.

BACKGROUND: Bacillus subtilis spores have been commonly used for the surface display of various food-related or human antigens or enzymes. For successful display, the target protein needs to be fused with an anchor protein. The preferred anchored proteins are the outer-coat proteins of spores; outer-coat proteins G (CotG) and C (CotC) are commonly used. In this study, mutant trehalose synthase (V407M/K490L/R680E TreS) was displayed on the surface of B. subtilis WB800n spores using CotG and CotC individually or in combination as an anchoring protein. RESULTS: Western blotting, immunofluorescence, dot blot, and enzymatic-activity assays detected TreS on the spore surface. The TreS activity with CotC and CotG together as the anchor protein was greater than the sum of the enzymatic activities with CotC or CotG alone. The TreS displayed on the spore surface with CotC and CotG together as the anchoring protein showed elevated and stable specific activity. To ensure spore stability and prevent spore germination in the trehalose preparation system, two germination-specific lytic genes, sleB and cwlJ, were deleted from the B. subtilis WB800n genome. It was demonstrated that this deletion did not affect the growth and spore formation of B. subtilis WB800n but strongly inhibited germination of the spores during transformation. The conversion rate of trehalose from 300 g/L maltose by B. subtilis strain WB800n(ΔsleB, ΔcwlJ)/cotC-treS-cotG-treS was 74.1% at 12 h (350 U/[g maltose]), and its enzymatic activity was largely retained, with a conversion rate of 73% after four cycles. CONCLUSIONS: The spore surface display system based on food-grade B. subtilis with CotC and CotG as a combined carrier appears to be a powerful technology for TreS expression, which may be used for the biotransformation of D-maltose into D-trehalose.

Triclosan Affects Ca2+ Regulatory Module and Musculature Development in Skeletal Myocyte during Early Life Stages of Zebrafish (Danio rerio).

Advanced technologies for toxicity tests are designed to identify biomarkers with superior predictive power or end points of the complex web of biological pathways. However, the data obtained need to be fully characterized for dose-response, physiological systems, and relevance to a system or (sub) population before biological interpretation and decision making. In this study, the toxicity of triclosan (TCS) on zebrafish was selected as a case study to correlate the observed morphological effects with existing data and identify the critical events by receptor activity sensitivity analysis. Triclosan exhibited weak acute toxicity against zebrafish and significantly affected the development of trunk muscles at 0.52, 1.04, and 1.73 µM. Through receptor-mediated screening, we found that the adverse effects of TCS induce Ryanodine receptor 1 (RyR1) activity and distort Ca2+ signaling. The trunk skeletal muscle abnormalities occurred only when the dihydropyridine receptor (DHPR) was blocked, demonstrating that TCS mainly influenced the Ca2+ regulatory module associated with signaling between DHPRs and RyR1; DHPRs mainly regulated the orthograde and retrograde signaling in skeletal muscles. This unexpected result could integrate the mode of action of TCS and provide insight for high-throughput screening and toxicity prediction using zebrafish.