Biodegradation Characteristics and Mechanism of Aflatoxin B1 by Bacillus amyloliquefaciens from Enzymatic and Multiomics Perspectives.

Aflatoxin B1 (AFB1), a mycotoxin and natural carcinogen, commonly contaminates cereals and animal feeds, posing serious health risks to human and animal. In this study, Bacillus amyloliquefaciens ZG08 isolated from kimchi could effectively remove 80.93% of AFB1 within 72 h at 37 °C and pH 7.0. Metabolome and transcriptome analysis showed that metabolic processes including glycerophospholipid metabolism and amino acid metabolism were most affected in B. amyloliquefaciens ZG08 exposed to AFB1. The adaptation mechanism likely involved activation of the thioredoxin system to restore intracellular redox equilibrium. The key genes, tpx and gldA, overexpressed in Escherichia coli BL21, achieved degradation rates of 60.15% and 47.16% for 100 µg/kg AFB1 under optimal conditions of 37 °C and pH 8.0 and 45 °C and pH 7.0, respectively. The degradation products, identified as AFD1, were less cytotoxic than AFB1 in HepG2 cells. These findings suggest potential strategies for utilizing probiotics and engineered enzymes in AFB1 detoxification.

Joint diffusion: mutual consistency-driven diffusion model for PET-MRI co-reconstruction.

OBJECTIVE: Positron Emission Tomography and Magnetic Resonance Imaging (PET-MRI) systems can obtain functional and anatomical scans. But PET suffers from a low signal-to-noise ratio, while MRI are time-consuming. To address time-consuming, an effective strategy involves reducing k-space data collection, albeit at the cost of lowering image quality. This study aims to leverage the inherent complementarity within PET-MRI data to enhance the image quality of PET-MRI. Apporach: A novel PET-MRI joint reconstruction model, termed MC-Diffusion, is proposed in the Bayesian framework. The joint reconstruction problem is transformed into a joint regularization problem, where data fidelity terms of PET and MRI are expressed independently. The regular term, the derivative of the logarithm of the joint probability distribution of PET and MRI, employs a joint score-based diffusion model for learning. The diffusion model involves the forward diffusion process and the reverse diffusion process. The forward diffusion process adds noise to transform a complex joint data distribution into a known joint prior distribution for PET and MRI simultaneously, resembling a denoiser. The reverse diffusion process removes noise using a denoiser to revert the joint prior distribution to the original joint data distribution, effectively utilizing joint probability distribution to describe the correlations of PET and MRI for improved quality of joint reconstruction. MAIN RESULTS: Qualitative and quantitative improvements are observed with the MC-Diffusion model. Comparative analysis against LPLS and Joint ISAT-net on the ADNI dataset demonstrates superior performance by exploiting complementary information between PET and MRI. The MC-Diffusion model effectively enhances the quality of PET and MRI images. SIGNIFICANCE: This study employs the MC-Diffusion model to enhance the quality of PET-MRI images by integrating the fundamental principles of PET and MRI modalities and their inherent complementarity. The MC-Diffusion model facilitates a more profound comprehension of the priors obtained through deep learning.

Bearing-DETR: A Lightweight Deep Learning Model for Bearing Defect Detection Based on RT-DETR.

Detecting bearing defects accurately and efficiently is critical for industrial safety and efficiency. This paper introduces Bearing-DETR, a deep learning model optimised using the Real-Time Detection Transformer (RT-DETR) architecture. Enhanced with Dysample Dynamic Upsampling, Efficient Model Optimization (EMO) with Meta-Mobile Blocks (MMB), and Deformable Large Kernel Attention (D-LKA), Bearing-DETR offers significant improvements in defect detection while maintaining a lightweight framework suitable for low-resource devices. Validated on a dataset from a chemical plant, Bearing-DETR outperformed the standard RT-DETR, achieving a mean average precision (mAP) of 94.3% at IoU = 0.5 and 57.5% at IoU = 0.5-0.95. It also reduced floating-point operations (FLOPs) to 8.2 G and parameters to 3.2 M, underscoring its enhanced efficiency and reduced computational demands. These results demonstrate the potential of Bearing-DETR to transform maintenance strategies and quality control across manufacturing environments, emphasising adaptability and impact on sustainability and operational costs.

Inflammatory myofibroblastic tumor of the adrenal gland: A case report.

Inflammatory Myofibroblastic Tumor (IMT) occurring in the adrenal gland is extremely rare, and pathologic examination is the gold standard for confirming the diagnosis. We report a case of IMT of adrenal origin in a patient whose diagnosis was confirmed by pathological examination after surgical resection of the tumor. Although previous studies have reported an overall favorable prognosis for IMT, regular and long-term follow-up is necessary.

Constructing a Microdiffusion-Seepage-Stress Multifield Coupling Model for Nanopore Gas.

Existing research is difficult to fully capture the correlation between gas molecules and pore wall interactions, multiphase flow, and stress distribution in nanopores. Taking gas as an example, a microscopic model was constructed. At the same time, diffusion, seepage, and stress were considered to accurately predict and manage gas transport in nanopores. First, molecular dynamics (MD) simulation methods were adopted to simulate the motion trajectories and interactions of gas molecules in nanopores. Second, a multiscale model was established based on continuum mechanics to consider the interaction between pore walls and gas molecules, and a diffusion equation was established to describe the diffusion process of gas molecules in pores. Then, finite element analysis and porous media models were used to simulate the seepage behavior of gas in the nanopores. Finally, the stress distribution in the pores was analyzed, and the influence of the interaction between the pore wall and gas molecules on stress was considered. The multifield coupling model was experimentally evaluated from three aspects: diffusion coefficient, seepage behavior, and stress distribution. The root-mean-square error (RMSE) and mean absolute error (MAE) of the model in different testing directions were calculated using different simulation tools, such as COMSOL, ANSYS, OpenFOAM, and CFX. The mean values of RMSE and MAE were lower than 0.20 and 0.17, respectively. The constructed model can comprehensively describe gas transmission within nanopores, improving the management accuracy and efficiency.

CRISPR-array-mediated imaging of non-repetitive and multiplex genomic loci in living cells.

Dynamic imaging of genomic loci is key for understanding gene regulation, but methods for imaging genomes, in particular non-repetitive DNAs, are limited. We developed CRISPRdelight, a DNA-labeling system based on endonuclease-deficient CRISPR-Cas12a (dCas12a), with an engineered CRISPR array to track DNA location and motion. CRISPRdelight enables robust imaging of all examined 12 non-repetitive genomic loci in different cell lines. We revealed the confined movement of the CCAT1 locus (chr8q24) at the nuclear periphery for repressed expression and active motion in the interior nucleus for transcription. We uncovered the selective repositioning of HSP gene loci to nuclear speckles, including a remarkable relocation of HSPH1 (chr13q12) for elevated transcription during stresses. Combining CRISPR-dCas12a and RNA aptamers allowed multiplex imaging of four types of satellite DNA loci with a single array, revealing their spatial proximity to the nucleolus-associated domain. CRISPRdelight is a user-friendly and robust system for imaging and tracking genomic dynamics and regulation.

2D arrays of hollow carbon nanoboxes: outward contraction-induced hollowing mechanism in Fe-N-C catalysts.

Maximizing the utilization efficiency of monatomic Fe sites in Fe-N-C catalysts poses a significant challenge for their commercial applications. Herein, a structural and electronic dual-modulation is achieved on a Fe-N-C catalyst to substantially enhance its catalytic performance. We develop a facile multi-component ice-templating co-assembly (MIC) strategy to construct two-dimensional (2D) arrays of monatomic Fe-anchored hollow carbon nanoboxes (Fe-HCBA) via a novel dual-outward interfacial contraction hollowing mechanism. The pore engineering not only enlarges the physical surface area and pore volume but also doubles the electrochemically active specific surface area. Additionally, the unique 2D carbon array structure reduces interfacial resistance and promotes electron/mass transfer. Consequently, the Fe-HCBA catalysts exhibit superior oxygen reduction performance with a six-fold enhancement in both mass activity (1.84 A cm-2) and turnover frequency (0.048 e- site-1 s-1), compared to microporous Fe-N-C catalysts. Moreover, the incorporation of phosphorus further enhances the total electrocatalytic performance by three times by regulating the electron structure of Fe-N4 sites. Benefitting from these outstanding characteristics, the optimal 2D P/Fe-HCBA catalyst exhibits great applicability in rechargeable liquid- and solid-state zinc-air batteries with peak power densities of 186 and 44.5 mW cm-2, respectively.

Genomic Selection for Weaning Weight in Alpine Merino Sheep Based on GWAS Prior Marker Information.

This study aims to compare the accuracy of genomic estimated breeding values (GEBV) estimated using a genomic best linear unbiased prediction (GBLUP) method and GEBV estimates incorporating prior marker information from a genome-wide association study (GWAS) for the weaning weight trait in highland Merino sheep. The objective is to provide theoretical and technical support for improving the accuracy of genomic selection. The study used a population of 1007 highland Merino ewes, with the weaning weight at 3 months as the target trait. The population was randomly divided into two groups. The first group was used for GWAS analysis to identify significant markers, and the top 5%, top 10%, top 15%, and top 20% markers were selected as prior marker information. The second group was used to estimate genetic parameters and compare the accuracy of GEBV predictions using different prior marker information. The accuracy was obtained using a five-fold cross-validation. Finally, both groups were subjected to cross-validation. The study's findings revealed that the heritability of the weaning weight trait, as calculated using the GBLUP model, ranged from 0.122 to 0.394, with corresponding prediction accuracies falling between 0.075 and 0.228. By incorporating prior marker information from GWAS, the heritability was enhanced to a range of 0.125 to 0.407. The inclusion of the top 5% to top 20% significant SNPs from GWAS results as prior information into GS showed potential for improving the accuracy of predicting genomic breeding value.

Nano-Bacillus Calmette-Guérin immunotherapies for improved bladder cancer treatment. / çº³ç±³å¡ä»‹è‹—æ”¹å–„è†€èƒ±ç™Œçš„å ç–«æ²»ç–—æ•ˆæžœ.

Cancer immunotherapy has rapidly become the fourth mainstream treatment alternative after surgery, radiotherapy, and chemotherapy, with some promising results. It aims to kill tumor cells by mobilizing or stimulating cytotoxic immune cells. However, the clinical applications of tumor immunotherapies are limited owing to a lack of adequate delivery pathways and high toxicity. Recently, nanomaterials and genetic engineering have shown great potential in overcoming these limitations by protecting the delivery of antigens, activating targeted T cells, modulating the immunosuppressive tumor microenvironment, and improving the treatment efficacy. Bacillus Calmette-Guérin (BCG) is a live attenuated Mycobacterium bovis vaccine used to prevent tuberculosis, which was first reported to have antitumor activity in 1927. BCG therapy can activate the immune system by inducing various cytokines and chemokines, and its specific immune and inflammatory responses exert antitumor effects. BCG was first used during the 1970s as an intravesical treatment agent for bladder cancer, which effectively improved immune antitumor activity and prevented tumor recurrence. More recently, nano-BCG and genetically engineered BCG have been proposed as treatment alternatives for bladder cancer due to their ability to induce stronger and more stable immune responses. In this study, we outline the development of nano-BCG and genetically engineered BCG for bladder cancer immunotherapy and review their potential and associated challenges.

Synthesizing PET images from high-field and ultra-high-field MR images using joint diffusion attention model.

BACKGROUND: Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET) stand as pivotal diagnostic tools for brain disorders, offering the potential for mutually enriching disease diagnostic perspectives. However, the costs associated with PET scans and the inherent radioactivity have limited the widespread application of PET. Furthermore, it is noteworthy to highlight the promising potential of high-field and ultra-high-field neuroimaging in cognitive neuroscience research and clinical practice. With the enhancement of MRI resolution, a related question arises: can high-resolution MRI improve the quality of PET images? PURPOSE: This study aims to enhance the quality of synthesized PET images by leveraging the superior resolution capabilities provided by high-field and ultra-high-field MRI. METHODS: From a statistical perspective, the joint probability distribution is considered the most direct and fundamental approach for representing the correlation between PET and MRI. In this study, we proposed a novel model, the joint diffusion attention model, namely, the joint diffusion attention model (JDAM), which primarily focuses on learning information about the joint probability distribution. JDAM consists of two primary processes: the diffusion process and the sampling process. During the diffusion process, PET gradually transforms into a Gaussian noise distribution by adding Gaussian noise, while MRI remains fixed. The central objective of the diffusion process is to learn the gradient of the logarithm of the joint probability distribution between MRI and noise PET. The sampling process operates as a predictor-corrector. The predictor initiates a reverse diffusion process, and the corrector applies Langevin dynamics. RESULTS: Experimental results from the publicly available Alzheimer's Disease Neuroimaging Initiative dataset highlight the effectiveness of the proposed model compared to state-of-the-art (SOTA) models such as Pix2pix and CycleGAN. Significantly, synthetic PET images guided by ultra-high-field MRI exhibit marked improvements in signal-to-noise characteristics when contrasted with those generated from high-field MRI data. These results have been endorsed by medical experts, who consider the PET images synthesized through JDAM to possess scientific merit. This endorsement is based on their symmetrical features and precise representation of regions displaying hypometabolism, a hallmark of Alzheimer's disease. CONCLUSIONS: This study establishes the feasibility of generating PET images from MRI. Synthesis of PET by JDAM significantly enhances image quality compared to SOTA models.

Metabolomic discoveries for early diagnosis and traditional Chinese medicine efficacy in ischemic stroke.

Ischemic stroke (IS), a devastating cerebrovascular accident, presents with high mortality and morbidity. Following IS onset, a cascade of pathological changes, including excitotoxicity, inflammatory damage, and blood-brain barrier disruption, significantly impacts prognosis. However, current clinical practices struggle with early diagnosis and identifying these alterations. Metabolomics, a powerful tool in systems biology, offers a promising avenue for uncovering early diagnostic biomarkers for IS. By analyzing dynamic metabolic profiles, metabolomics can not only aid in identifying early IS biomarkers but also evaluate Traditional Chinese Medicine (TCM) efficacy and explore its mechanisms of action in IS treatment. Animal studies demonstrate that TCM interventions modulate specific metabolite levels, potentially reflecting their therapeutic effects. Identifying relevant metabolites in cerebral ischemia patients holds immense potential for early diagnosis and improved outcomes. This review focuses on recent metabolomic discoveries of potential early diagnostic biomarkers for IS. We explore variations in metabolites observed across different ages, genders, disease severity, and stages. Additionally, the review examines how specific TCM extracts influence IS development through metabolic changes, potentially revealing their mechanisms of action. Finally, we emphasize the importance of integrating metabolomics with other omics approaches for a comprehensive understanding of IS pathophysiology and TCM efficacy, paving the way for precision medicine in IS management.

The supraclavicular approach in the management of cervicothoracic-junction benign neurogenic tumors: A real-world analysis.

Objectives: The study objectives were to evaluate the safety, feasibility, and risk of neurologic complications with the supraclavicular approach in the operative management of cervicothoracic-junction benign neurogenic tumors. Methods: Between January 2012 and April 2023, 115 patients who underwent surgical resection for cervicothoracic-junction benign neurogenic tumors were retrospectively enrolled. Patients were divided into 3 groups based on the surgical approach: supraclavicular alone (Supraclav-Alone), n = 16; Transthoracic-Alone (video-assisted thoracoscopic surgery/Open), n = 87; and supraclavicular combined with transthoracic (Supraclav + video-assisted thoracoscopic surgery/open), n = 12. Clinicopathologic variables and postoperative morbidity including neurologic complications were summarized among the groups. Logistic regression analysis was performed to identify predictors for long-term (>6 months) brachial plexus injuries. Results: The cohort comprised 28 patients (24.3%) who underwent surgical resection using a supraclavicular approach. The Supraclav-Alone group portended the most cephalad location of tumor, the smallest pathologic tumor size, the shortest operative time, the least blood loss, and the least postoperative pain. The incidence of surgical complications, phrenic nerve neuropraxia, recurrent laryngeal nerve neuropraxia, or Horner's syndrome was similar among the groups postoperatively. However, use of the supraclavicular-alone approach (adjusted odds ratio, 0.165; 95% CI, 0.017-0.775) was a predictor for long-term brachial plexus injury complications. Among patients who experienced brachial plexus injury complications, the proportion of patients achieving complete resolution was higher among those undergoing a supraclavicular approach group (Supraclav-Alone: 80.0% vs Supraclav + video-assisted thoracoscopic surgery/Open: 60.0% vs video-assisted thoracoscopic surgery/Open: 25.8%). Conclusions: The supraclavicular approach may be a safe and feasible strategy in the management of cervicothoracic-junction benign neurogenic tumors that does not increase surgical complications and minimizes the severity of brachial plexus injury.

Sexually Dimorphic Response to Hepatic Injury in Newborn Suffering from Intrauterine Growth Restriction.

Intrauterine growth restriction (IUGR), when a fetus does not grow as expected, is associated with a reduction in hepatic functionality and a higher risk for chronic liver disease in adulthood. Utilizing early developmental plasticity to reverse the outcome of poor fetal programming remains an unexplored area. Focusing on the biochemical profiles of neonates and previous transcriptome findings, piglets from the same fetus are selected as models for studying IUGR. The cellular landscape of the liver is created by scRNA-seq to reveal sex-dependent patterns in IUGR-induced hepatic injury. One week after birth, IUGR piglets experience hypoxic stress. IUGR females exhibit fibroblast-driven T cell conversion into an immune-adapted phenotype, which effectively alleviates inflammation and fosters hepatic regeneration. In contrast, males experience even more severe hepatic injury. Prolonged inflammation due to disrupted lipid metabolism hinders intercellular communication among non-immune cells, which ultimately impairs liver regeneration even into adulthood. Additionally, Apolipoprotein A4 (APOA4) is explored as a novel biomarker by reducing hepatic triglyceride deposition as a protective response against hypoxia in IUGR males. PPARα activation can mitigate hepatic damage and meanwhile restore over-expressed APOA4 to normal in IUGR males. The pioneering study offers valuable insights into the sexually dimorphic responses to hepatic injury during IUGR.

Glycyrrhizin alleviates BoAHV-1-induced lung injury in guinea pigs by inhibiting the NF-κB/NLRP3 Signaling pathway and activating the Nrf2/HO-1 Signaling pathway.

Varicellovirus bovinealpha 1 (BoAHV-1) is a significant pathogen responsible for respiratory disease in cattle, capable of inducing lung damage independently or co-infection with bacteria. The widespread spread of BoAHV-1 in cattle herds has caused substantial economic losses to the cattle industry. The pathogenic mechanisms of BoAHV-1 are often relevant to robust inflammatory responses, increased oxidative burden, and the initiation of apoptosis. Glycyrrhizin (GLY) is a small-molecule triterpenoid saponin compound obtained from the herb liquorice, which has a broad spectrum of pharmacological properties such as antiviral, anti-inflammatory, and antioxidant effects. Furthermore, GLY regulates lung physiology by modulating oxidative stress, inflammatory response, and cell apoptosis through interference with the NF-κB/NLRP3 and Nrf2/HO-1 Signaling pathways. However, the potential of GLY to mitigate lung injury induced by BoAHV-1 and its underlying mechanism remains unclear. Therefore, in this study, we investigated the protective effect of GLY against pulmonary injury induced by BoAHV-1 in a guinea pig model by reducing viral load and suppressing the inflammatory response, oxidative stress, and apoptosis. The results of this study demonstrated that GLY exerted a protective effect against BoAHV-1-induced lung injury in guinea pigs. Specifically, GLY reduced the levels of pro-inflammatory cytokines interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, and interleukin (IL)-8 in guinea pig tissues while suppressing the expression of Caspase-1. Additionally, GLY reduced BoAHV-1 load and the number of TUNEL-positive lung cells in guinea pig lungs while inhibiting Caspase 3 protein expression. Furthermore, GLY significantly enhanced lung antioxidant capacity by increasing superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activity while simultaneously reducing malondialdehyde (MDA) levels. Lung histological observation and score further validated the protective effect of GLY on BoAHV-1-induced lung injury. Furthermore, we observed that the expression of phosphorylated NF-κB p65 (p-NF-κB p65) and NLRP3 proteins in the lung tissue of BoAHV-1-infected guinea pigs decreased after GLY treatment while the expression of Nrf2 and HO-1 proteins increased. These results indicated that GLY inhibited the NF-κB/NLRP3 Signaling pathway and activated the Nrf2/HO-1 Signaling pathway during BoAHV-1 infection. Ultimately, our findings demonstrated that GLY alleviates BoAHV-1-induced inflammation response, oxidative stress, and cell apoptosis by inhibiting the NF-κB/NLRP3 Signaling pathway and activating the Nrf2/HO-1 Signaling pathway to protect guinea pigs from lung injury caused by BoAHV-1. Ultimately, our findings demonstrated that GLY alleviates BoAHV-1-induced inflammation response, oxidative stress, and cell apoptosis by inhibiting the NF-κB/NLRP3 Signaling pathway and activating the Nrf2/HO-1 Signaling pathway to protect guinea pigs from lung injury caused by BoAHV-1. Importantly, this study provides a compelling argument for the GLY in combating respiratory disease in cattle caused by BoAHV-1.

A Visible Light-Responsive TiO2 Photocathode Achieved by a Rh Dopant.

Developing an efficient and stable photocathode material for photoelectrochemical solar water splitting remains challenging. Herein, we demonstrate the potential of rutile TiO2 as a photocathode by Rh doping with visible light absorption up to 640 nm and an onset potential of 0.9 V versus the reversible hydrogen electrode. The dopant transforms the rutile host from an n-type semiconductor to a p-type one, as confirmed by the Mott-Schottky curve and kelvin probe force microscopy. Physical and photoelectrochemical analyses further suggest that the doping mechanism is dependent on concentration. Lower levels of dopants generate localized Rh3+, while higher levels favor Rh4+ that interacts more strongly with the O 2p orbitals. The latter is found not only to extend the visible light absorption range but also to facilitate charge transport. This work elucidates the role of the Rh dopant in adjusting the photoelectrochemical behavior of TiO2, and it provides a promising photocathode material for solar energy conversion.

Conformal and conductive biofilm-bridged artificial Z-scheme system for visible light-driven overall water splitting.

Semi-artificial Z-scheme systems offer promising potential toward efficient solar-to-chemical conversion, yet sustainable and stable designs are currently lacking. Here, we developed a sustainable hybrid Z-scheme system capable for visible light-driven overall water splitting by integrating the durability of inorganic photocatalysts with the interfacial adhesion and regenerative property of bacterial biofilms. The Z-scheme configuration is fabricated by drop casting a mixture of photocatalysts onto a glass plate, followed by the growth of biofilms for conformal conductive paste through oxidative polymerization of pyrrole molecules. Notably, the system exhibited scalability indicated by consistent catalytic efficiency across various sheet areas, resistance observed by remarkable maintaining of photocatalytic efficiency across a range of background pressures, and high stability as evidenced by minimal decay of photocatalytic efficiency after 100-hour reaction. Our work thus provides a promising avenue toward sustainable and high-efficiency artificial photosynthesis, contributing to the broader goal of sustainable energy solutions.

Progress of nanoparticle drug delivery system for the treatment of glioma.

Gliomas are typical malignant brain tumours affecting a wide population worldwide. Operation, as the common treatment for gliomas, is always accompanied by postoperative drug chemotherapy, but cannot cure patients. The main challenges are chemotherapeutic drugs have low blood-brain barrier passage rate and a lot of serious adverse effects, meanwhile, they have difficulty targeting glioma issues. Nowadays, the emergence of nanoparticles (NPs) drug delivery systems (NDDS) has provided a new promising approach for the treatment of gliomas owing to their excellent biodegradability, high stability, good biocompatibility, low toxicity, and minimal adverse effects. Herein, we reviewed the types and delivery mechanisms of NPs currently used in gliomas, including passive and active brain targeting drug delivery. In particular, we primarily focused on various hopeful types of NPs (such as liposome, chitosan, ferritin, graphene oxide, silica nanoparticle, nanogel, neutrophil, and adeno-associated virus), and discussed their advantages, disadvantages, and progress in preclinical trials. Moreover, we outlined the clinical trials of NPs applied in gliomas. According to this review, we provide an outlook of the prospects of NDDS for treating gliomas and summarise some methods that can enhance the targeting specificity and safety of NPs, like surface modification and conjugating ligands and peptides. Although there are still some limitations of these NPs, NDDS will offer the potential for curing glioma patients.

Screening of bacterial endophytes of larch against Neofusicoccum laricinum and validation of their safety.

In order to provide a highly feasible research pathway for the control of larch shoot blight, healthy larch branches and leaves were collected from 13 sampling sites in 8 provinces in China. The antagonistic endophytic bacteria obtained from the screening were used to carry out disease control experiments in potted seedlings. The safety evaluation test was conducted on the antagonistic bacteria. Subsequently, the strains with better preventive effect and high safety were identified by morphological and molecular methods. A total of 391 strains of endophytic bacteria were isolated from healthy larch branches and leaves. Seventy-eight strains of larch endophytic bacteria with antagonistic effect were obtained by primary sieving. Ten strains of endophytic bacteria with obvious antagonism were further obtained by secondary sieving, and all of them had an inhibition rate of more than 57%. Among them, strains YN 2, JL 6, NMG 23, and JL 54 showed the highest inhibition rate of 63.16%-65.08%, which was significantly different from the other treatments. The results of the pot test showed that 14 days after inoculation with the pathogen, strains YN 2 and JL 54 were more effective in the control of larch shoot blight, with the preventive effects reaching 57.7% and 50.0%, respectively. Strains JL 6 and JL 54 were biologically safe in the safety evaluation test. Therefore, strain JL 54 was selected for identification. It was identified as Bacillus amyloliquefaciens through morphological observation, 16S rDNA sequence, gyrB gene sequence and 16S rDNA-gyrB tandem feature sequence analysis. IMPORTANCE: Larch shoot blight is a widely distributed, damaging, and rapidly spreading fungal disease of forest trees that poses a serious threat to larch plantations. Endophytic bacteria have biological effects on host plants against pests and diseases, and they have a growth-promoting effect on plants. In this paper, we investigated for the first time the biocontrol effect of endophytic bacteria on larch shoot blight by screening endophytic bacteria with the function of antagonizing dieback fungi. Bacillus amyloliquefaciens JL 54 has a better prospect of biocontrol against larch shoot blight, which lays the foundation for the application of this bacterium in the future.

The Influence of Homologous Arm Length on Homologous Recombination Gene Editing Efficiency Mediated by SSB/CRISPR-Cas9 in Escherichia coli.

The precise editing of genes mediated by CRISPR-Cas9 necessitates the application of donor DNA with appropriate lengths of homologous arms and fragment sizes. Our previous development, SSB/CRISPR-Cas9, has demonstrated high efficiency in homologous recombination and non-homologous end joining gene editing within bacteria. In this study, we optimized the lengths and sizes of homologous arms of the donor DNA within this system. Two sets of donor DNA constructs were generated: one set comprised donors with only 10-100 bp homologous arms, while the other set included donors with homologous arms ranging from 10-100 bp, between which was a tetracycline resistance expression cassette (1439 bp). These donor constructs were transformed into Escherichia coli MG1655 cells alongside pCas-SSB/pTargetF-lacZ. Notably, when the homologous arms ranged from 10 to 70 bp, the transformation efficiency of non-selectable donors was significantly higher than that of selectable donors. However, within the range of 10-100 bp homologous arm lengths, the homologous recombination rate of selectable donors was significantly higher than that of non-selectable donors, with the gap narrowing as the homologous arm length increased. For selectable donor DNA with homologous arm lengths of 10-60 bp, the homologous recombination rate increased linearly, reaching a plateau when the homologous arm length was between 60-100 bp. Conversely, for non-selectable donor DNA, the homologous recombination rate increased linearly with homologous arm lengths of 10-90 bp, plateauing at 90-100 bp. Editing two loci simultaneously with 100 bp homologous arms, whether selectable or non-selectable, showed no difference in transformation or homologous recombination rates. Editing three loci simultaneously with 100 bp non-selectable homologous arms resulted in a 45% homologous recombination rate. These results suggest that efficient homologous recombination gene editing mediated by SSB/CRISPR-Cas9 can be achieved using donor DNA with 90-100 bp non-selectable homologous arms or 60-100 bp selectable homologous arms.

Stabilization of EREG via STT3B-mediated N-glycosylation is critical for PDL1 upregulation and immune evasion in head and neck squamous cell carcinoma.

Dysregulated Epiregulin (EREG) can activate epidermal growth factor receptor (EGFR) and promote tumor progression in head and neck squamous cell carcinoma (HNSCC). However, the mechanisms underlying EREG dysregulation remain largely unknown. Here, we showed that dysregulated EREG was highly associated with enhanced PDL1 in HNSCC tissues. Treatment of HNSCC cells with EREG resulted in upregulated PDL1 via the c-myc pathway. Of note, we found that N-glycosylation of EREG was essential for its stability, membrane location, biological function, and upregulation of its downstream target PDL1 in HNSCC. EREG was glycosylated at N47 via STT3B glycosyltransferases, whereas mutations at N47 site abrogated N-glycosylation and destabilized EREG. Consistently, knockdown of STT3B suppressed glycosylated EREG and inhibited PDL1 in HNSCC cells. Moreover, treatment of HNSCC cells with NGI-1, an inhibitor of STT3B, blocked STT3B-mediated glycosylation of EREG, leading to its degradation and suppression of PDL1. Finally, combination of NGI-1 treatment with anti-PDLl therapy synergistically enhanced the efficacy of immunotherapy of HNSCC in vivo. Taken together, STT3B-mediated N-glycosylation is essential for stabilization of EREG, which mediates PDL1 upregulation and immune evasion in HNSCC.