Publications by authors named "Peipei Zhang"

310 Publications

Biofilm-forming capacity of isolated from cattle and beef packing plants: relation to virulence attributes, stage of processing, antimicrobial interventions, and heat tolerance.

Appl Environ Microbiol 2021 Sep 22:AEM0112621. Epub 2021 Sep 22.

Agriculture and Agri-Food Canada, 6000 C&E Trail, Lacombe, Alberta T4L 1W1, Canada.

Despite the importance of biofilm formation in contamination of meat by pathogenic at slaughter plants, drivers for biofilm remain unclear. To identify selection pressures for biofilm, we evaluated 745 isolates from cattle and 700 generic from two beef slaughter plants for motility, expression of curli and cellulose, and biofilm-forming potential. Cattle isolates were also screened for serogroup, , , and Generic were compared by source (hide of carcass, hide-off carcass, processing equipment) before and after implementation of antimicrobial hurdles. The proportion of capable of forming biofilms was lowest (7.1%; < 0.05) for cattle isolates and highest (87.3%; < 0.05) from equipment. Only one enterohemorrhagic (EHEC) was an extremely-strong biofilm-former, in contrast to 73.4% of from equipment. Isolates from equipment after sanitation had a greater biofilm-forming capacity ( < 0.001) than those before sanitation. Most cattle isolates were motile and expressed curli, although these traits along with expression of cellulose and detection of were not necessary for biofilm formation. In contrast, isolates capable of forming biofilms on equipment were almost exclusively motile and able to express curli. Results of the present study indicate that cattle would rarely carry EHEC capable of making strong biofilms to slaughter plants. However, if biofilm-forming EHEC contaminated equipment, current sanitation procedures may not eliminate the most robust biofilm-forming strains. Accordingly, new and effective anti-biofilm hurdles are required for meat-processing equipment to reduce future instances of food-borne disease. As the majority of enterohemorrhagic (EHEC) are not capable of forming biofilms, sources were undetermined of the biofilm-forming EHEC isolated from 'high-event periods' in beef slaughter plants. This study demonstrated that sanitation procedures used on beef-processing equipment may inadvertently lead to survival of robust biofilm-forming strains of . Cattle only rarely carry EHEC capable of forming strong biofilms (1/745 isolates evaluated), but isolates with greater biofilm-forming capacity were more likely ( < 0.001) to survive equipment sanitation. In contrast, chilling carcasses for 3 days at 0°C reduced ( < 0.05) the proportion of biofilm-forming . Consequently, an additional anti-biofilm hurdle for meat-processing equipment, perhaps involving cold exposure, is necessary to further reduce the risk of food-borne disease.
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http://dx.doi.org/10.1128/AEM.01126-21DOI Listing
September 2021

Genomic and phenotypic analysis of heat and sanitizer resistance in from beef in relation to the locus of heat resistance.

Appl Environ Microbiol 2021 Sep 22:AEM0157421. Epub 2021 Sep 22.

Agriculture and Agri-Food Canada, 6000 C&E Trail, Lacombe, Alberta, Canada T4L 1W1.

The locus of heat resistance (LHR) can confer heat resistance to to various extents. This study investigated the phylogenetic relationships, and genomic and phenotypic characteristics of with or without LHR recovered from beef by direct plating or from enrichment broth at 42°C. LHR-positive isolates (n=24) were whole genome-sequenced by short- and long-reads. LHR-negative isolates (n=18) from equivalent sources as LHR-positive isolates were short-read sequenced. All isolates were assessed for decimal reduction time at 60°C () and susceptibility to E-SAN and Perox-E. Selected isolates were evaluated for growth at 42°C. The LHR-positive and negative isolates were well separated on the core genome tree, with 22/24 of the positive isolates clustering into three clades. Isolates within clade 1 and 2, despite their different values, were clonal, as determined by subtyping (MLST, core genome MLST, and serotyping). Isolates within each clade are of one serotype. The LHR-negative isolates were genetically diverse. The LHR-positive isolates had a larger (p<0.001) median genome size by 0.3 Mbp (5.0 vs 4.7 Mbp), and overrepresentation of genes in plasmid maintenance, stress response and cryptic prophages, but underrepresentation of genes involved in epithelial attachment and virulence. All LHR-positive isolates harbored a chromosomal copy of LHR, and all clade 2 isolates had an additional partial copy of LHR on conjugative plasmids. The growth rates at 42°C were 0.71±0.02 and 0.65±0.02 logOD h for LHR-positive and negative isolates. No meaningful difference in sanitizer susceptibility was noted between LHR-positive and negative isolates. Resistant bacteria are serious food safety and public health concerns. Heat resistance conferred by the LHR varies largely among different strains. The findings in this study show that genomic background and composition of LHR, in addition to the presence of LHR, play an important role in the degree of heat resistance in , and that strains with certain genetic background are more likely to acquire and maintain the LHR. Also, caution should be exercised when recovering at elevated temperatures as the presence of LHR may confer growth advantages to some strains. Interestingly, the LHR harboring strains seem to have evolved further from their primary animal host to adapt to their secondary habitat, as reflected by fewer genes in virulence and epithelial attachment. The phylogenetic relationships among the isolates point towards multiple mechanisms for acquiring LHR, likely prior to their deposition on meat.
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http://dx.doi.org/10.1128/AEM.01574-21DOI Listing
September 2021

The role of interferon regulatory factor 8 for retinal tissue homeostasis and development of choroidal neovascularisation.

J Neuroinflammation 2021 Sep 20;18(1):215. Epub 2021 Sep 20.

Medical Faculty, Eye Center, University Hospital, University of Freiburg, Freiburg im Breisgau, Germany.

Background: Microglia cells represent the resident innate immune cells of the retina and are important for retinal development and tissue homeostasis. However, dysfunctional microglia can have a negative impact on the structural and functional integrity of the retina under native and pathological conditions.

Methods: In this study, we examined interferon-regulatory factor 8 (Irf8)-deficient mice to determine the transcriptional profile, morphology, and temporospatial distribution of microglia lacking Irf8 and to explore the effects on retinal development, tissue homeostasis, and formation of choroidal neovascularisation (CNV).

Results: Our study shows that Irf8-deficient MG exhibit a considerable loss of microglial signature genes accompanied by a severely altered MG morphology. An in-depth characterisation by fundus photography, fluorescein angiography, optical coherence tomography and electroretinography revealed no major retinal abnormalities during steady state. However, in the laser-induced CNV model, Irf8-deficient microglia showed an increased activity of biological processes critical for inflammation and cell adhesion and a reduced MG cell density near the lesions, which was associated with significantly increased CNV lesion size.

Conclusions: Our results suggest that loss of Irf8 in microglia has negligible effects on retinal homeostasis in the steady state. However, under pathological conditions, Irf8 is crucial for the transformation of resident microglia into a reactive phenotype and thus for the suppression of retinal inflammation and CNV formation.
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http://dx.doi.org/10.1186/s12974-021-02230-yDOI Listing
September 2021

TPM3 mediates epithelial-mesenchymal transition in esophageal cancer via MMP2/MMP9.

Ann Transl Med 2021 Aug;9(16):1338

Department of Thoracic Surgery, Fujian Medical University Union Hospital, Fuzhou, China.

Background: Esophageal cancer (EC) is a malignant tumor with high mortality. Correlations have been found between the expression level of tropomyosin 3 (TPM3) and the depth of tumor invasion, lymph node metastasis, and the 5-year survival rate. However, the specific mechanisms underlying EC remain unclear.

Methods: Stably transfected TPM3-overexpresing and TPM3-knockdown esophageal squamous cell carcinoma (ESCC) cell lines (ECa109 and EC9706) were constructed, and the association between TPM3 and the proliferation, invasion, and migration of ESCC was investigated using molecular biology methods. The associations between TPM3 and matrix metalloproteinase (MMP)2/9 or epithelial-mesenchymal transition (EMT)-related proteins were verified, and the potential tumor-promoting mechanism was explored by Gelatin Zymography Experiment.

Results: TPM3 was found to promote the proliferation, migration, and metastatic potential of ESCC and in vitro, and stimulate the expression of MMP2/9 and certain EMT markers other than E-cadherin. The replenishment of MMP2/9 restored the malignant behavior of ESCC caused by TPM3. A gelatinase assay showed that the expression of TPM3 was related to the activity of MMP9.

Conclusions: TPM3 promoted proliferation, migration, and metastatic potential in EC cells. Additionally, TPM3 promoted the EMT process. This function may be achieved via the regulation the expression of MMP2/9.
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http://dx.doi.org/10.21037/atm-21-4043DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8422148PMC
August 2021

A Case of a 49-Year-Old Man with Nonclassical Fabry Disease Diagnosed by Renal Biopsy.

Nephron 2021 Sep 14:1-4. Epub 2021 Sep 14.

Department of Nephrology, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Traditional Chinese Medicine), Hangzhou, China.

Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by mutations in the galactosidase A (GLA) gene that result in deficiency of α-GLA activity, leading to major organ failure and premature mortality. According to different disease courses, FD can be divided into classical and nonclassical phenotypes. The nonclassical FD phenotype is always absent of characteristic symptoms, which makes identifying it challenging. This article presents a 49-year-old man with a 10-year history of proteinuria and decreased glomerular filtration rate. An electrocardiogram showed a complete right bundle branch block and abnormal Q waves in high lateral, accompanied by dramatically elevated ST segment. Consequently, a renal biopsy was performed. Vacuolation was found in many podocytes in light microscopic examinations. Similarly, a myelin-like structure was detected by electron microscopy. Pathological findings were most consistent with FD. Consequently, genetic analysis, p.R301Q (c.902G>A [p.Arg301Gln]), confirmed the FD diagnosis. Angiotensin receptor blocker and traditional Chinese medicine, but not enzyme replacement therapy, were prescribed due to financial constraints. The patient had stabilization of kidney disease 6 months later. The case showed that renal biopsy should be performed in patients with cardiac and renal symptoms, which could contribute toward the correct diagnosis for nonclassical FD type.
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http://dx.doi.org/10.1159/000516924DOI Listing
September 2021

Cell Coding Arrays Based on Fluorescent Glycan Nanoparticles for Cell Line Identification and Cell Contamination Evaluation.

ACS Appl Mater Interfaces 2021 Sep 9;13(37):44054-44064. Epub 2021 Sep 9.

State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.

Cell lines are applied on a large scale in the field of biomedicine, but they are susceptible to issues such as misidentification and cross-contamination. This situation is becoming worse over time due to the rapid growth of the biomedical field, and thus there is an urgent need for a more effective strategy to address the problem. As described herein, a cell coding method is established based on two types of uniform and stable glycan nanoparticles that are synthesized using the graft-copolymerization-induced self-assembly (GISA) method, which further exhibit distinct fluorescent properties due to elaborate modification with fluorescent labeling molecules. The different affinity between each nanoparticle and various cell lines results in clearly distinguishable differences in their endocytosis degrees, thus resulting in distinct characteristic fluorescence intensities. Through flow cytometry measurements, the specific signals of each cell sample can be recorded and turned into a map divided into different regions by statistical processing. Using this sensing array strategy, we have successfully identified six human cell lines, including one normal type and five tumor types. Moreover, cell contamination evaluation of different cell lines with HeLa cells as the contaminant in a semiquantitative analysis has also been successfully achieved. Notably, the whole process of nanoparticle fabrication and fluorescent testing is facile and the results are highly reliable.
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http://dx.doi.org/10.1021/acsami.1c12674DOI Listing
September 2021

Stability of tropical forest tree carbon-water relations in a rainfall exclusion treatment through shifts in effective water uptake depth.

Glob Chang Biol 2021 Sep 1. Epub 2021 Sep 1.

Climate Sciences Department, Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA.

Increasing severity and frequency of drought is predicted for large portions of the terrestrial biosphere, with major impacts already documented in wet tropical forests. Using a 4-year rainfall exclusion experiment in the Daintree Rainforest in northeast Australia, we examined canopy tree responses to reduced precipitation and soil water availability by quantifying seasonal changes in plant hydraulic and carbon traits for 11 tree species between control and drought treatments. Even with reduced soil volumetric water content in the upper 1 m of soil in the drought treatment, we found no significant difference between treatments for predawn and midday leaf water potential, photosynthesis, stomatal conductance, foliar stable carbon isotope composition, leaf mass per area, turgor loss point, xylem vessel anatomy, or leaf and stem nonstructural carbohydrates. While empirical measurements of aboveground traits revealed homeostatic maintenance of plant water status and traits in response to reduced soil moisture, modeled belowground dynamics revealed that trees in the drought treatment shifted the depth from which water was acquired to deeper soil layers. These findings reveal that belowground acclimation of tree water uptake depth may buffer tropical rainforests from more severe droughts that may arise in future with climate change.
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http://dx.doi.org/10.1111/gcb.15869DOI Listing
September 2021

Identification of Key Genes and Pathways Associated With Paclitaxel Resistance in Esophageal Squamous Cell Carcinoma Based on Bioinformatics Analysis.

Front Genet 2021 11;12:671639. Epub 2021 Aug 11.

Department of Thoracic Surgery, Fujian Medical University Union Hospital, Fuzhou, China.

Esophageal squamous cell carcinoma (ESCC) ranks as the fourth leading cause of cancer-related death in China. Although paclitaxel has been shown to be effective in treating ESCC, the prolonged use of this chemical will lead to paclitaxel resistance. In order to uncover genes and pathways driving paclitaxel resistance in the progression of ESCC, bioinformatics analyses were performed based on The Cancer Genome Atlas (TCGA) database and the Gene Expression Omnibus (GEO) database including GSE86099 and GSE161533. Differential expression analysis was performed in TCGA data and two GEO datasets to obtain differentially expressed genes (DEGs). Based on GSE161533, weighted gene co-expression network analysis (WGCNA) was conducted to identify the key modules associated with ESCC tumor status. The DEGs common to the two GEO datasets and the genes in the key modules were intersected to obtain the paclitaxel resistance-specific or non-paclitaxel resistance-specific genes, which were subjected to subsequent least absolute shrinkage and selection operator (LASSO) feature selection, whereby paclitaxel resistance-specific or non-paclitaxel resistance-specific key genes were selected. Ten machine learning models were used to validate the biological significance of these key genes; the potential therapeutic drugs for paclitaxel resistance-specific genes were also predicted. As a result, we identified 24 paclitaxel resistance-specific genes and 18 non-paclitaxel resistance-specific genes. The ESCC machine classifiers based on the key genes achieved a relatively high AUC value in the cross-validation and in an independent test set, GSE164158. A total of 207 drugs (such as bevacizumab) were predicted to be alternative therapeutics for ESCC patients with paclitaxel resistance. These results might shed light on the in-depth research of paclitaxel resistance in the context of ESCC progression.
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http://dx.doi.org/10.3389/fgene.2021.671639DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8386171PMC
August 2021

Emerging cardioprotective mechanisms of vitamin B6: a narrative review.

Eur J Nutr 2021 Aug 26. Epub 2021 Aug 26.

Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-8528, Japan.

Although overt vitamin B6 deficiency is rare, marginal vitamin B6 deficiency is frequent and occurs in a consistent proportion of the population. The marginal vitamin B6 deficiency appears to relate to an increased risk of inflammation-related diseases, such as cardiovascular diseases and cancers. Of all the cardiovascular diseases, heart failure is a complex clinical syndrome associated with a high mortality rate. So far, information regarding the cardioprotective mechanisms of vitamin B6 has been limited. Meanwhile, recent studies have revealed that vitamin B6 treatment increases cardiac levels of imidazole dipeptides (e.g., carnosine, anserine, and homocarnosine), histamine, and γ-aminobutyric acid (GABA) and suppresses P2X7 receptor-mediated NLRP3 inflammasome. These modulations may imply potential cardioprotective mechanisms of vitamin B6. These modulations may also be involved in the underlying mechanisms through which vitamin B6 suppresses oxidative stress and inflammation. This review provides an up-to-date evaluation of our current understanding of the cardioprotective mechanisms of vitamin B6.
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http://dx.doi.org/10.1007/s00394-021-02665-2DOI Listing
August 2021

Genome Sequences of Bacteriophages cd2, cd3, and cd4, which Specifically Target Carnobacterium divergens.

Microbiol Resour Announc 2021 Aug 26;10(34):e0063621. Epub 2021 Aug 26.

Department of Chemistry, The King's University, Edmonton, Alberta, Canada.

Carnobacteria have been implicated in food spoilage, but also in protection against pathogenic bacteria. We report the isolation and complete genome sequences of three bacteriophages (phages cd2, cd3, and cd4) that specifically target Carnobacterium divergens. The genome sizes are approximately 57 kbp and have limited homology to known enterococcal and streptococcal phages.
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http://dx.doi.org/10.1128/MRA.00636-21DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8388549PMC
August 2021

Pyroptosis of syncytia formed by fusion of SARS-CoV-2 spike and ACE2-expressing cells.

Cell Discov 2021 Aug 24;7(1):73. Epub 2021 Aug 24.

State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China.

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http://dx.doi.org/10.1038/s41421-021-00310-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8384103PMC
August 2021

Enhanced SA and Ca signaling results in PCD-mediated spontaneous leaf necrosis in wheat mutant wsl.

Mol Genet Genomics 2021 Aug 23. Epub 2021 Aug 23.

National Centre of Engineering and Technological Research for Wheat / National Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, 450046, China.

Leaf is the major photosynthesis organ and the key source of wheat (Triticum aestivum L.) grain. Spotted leaf (spl) mutant is a kind of leaf lesion mimic mutants (LMMs) in plants, which is an ideal material for studying the mechanisms of leaf development. In this study, we report the leaf abnormal development molecular mechanism of a spl mutant named white stripe leaf (wsl) derived from wheat cultivar Guomai 301 (WT). Histochemical observation indicated that the leaf mesophyll cells of the wsl were destroyed in the necrosis regions. To explore the molecular regulatory network of the leaf development in mutant wsl, we employed transcriptome analysis, histochemistry, quantitative real-time PCR (qRT-PCR), and observations of the key metabolites and photosynthesis parameters. Compared to WT, the expressions of the chlorophyll synthesis and photosynthesis-related homeotic genes were repressed; many genes in the WRKY transcription factor (TF) families were highly expressed; the salicylic acid (SA) and Ca signal transductions were enhanced in wsl. Both the chlorophyll contents and the photosynthesis rate were lower in wsl. The contents of SA and reactive oxygen species (ROS) were significantly higher, and the leaf rust resistance was enhanced in wsl. Based on the experimental data, a primary molecular regulatory model for leaf development in wsl was established. The results indicated that the SA accumulation and enhanced Ca signaling led to programmed cell death (PCD), and ultimately resulted in spontaneous leaf necrosis of wsl. These results laid a solid foundation for further research on the molecular mechanism of leaf development in wheat.
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http://dx.doi.org/10.1007/s00438-021-01811-zDOI Listing
August 2021

Occupational class differences in outcomes after ischemic stroke: a prospective observational study.

BMC Public Health 2021 08 19;21(1):1571. Epub 2021 Aug 19.

Department of Epidemiology, School of Public Health and Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, 199 Renai Road, Industrial Park District, Suzhou, Jiangsu Province, 215123, People's Republic of China.

Background: Occupational class is an integral part of socioeconomic status. The studies focused on the occupational difference in ischemic stroke outcome in a Chinese population are limited. We aimed to investigate the associations between occupational class and the prognosis of patients with ischemic stroke in China.

Methods: We included 1484 ischemic stroke participants (mean age: 63.42 ± 11.26 years) from the prospective cohort study: Infectious Factors, Inflammatory Markers and Prognosis of Acute Ischemic Stroke (IIPAIS). Occupational class was categorized into white-collar workers, blue-collar workers and farmers in our study. Study outcomes were cardiovascular events and all-cause mortality within 12 months after ischemic stroke onset. We applied Cox proportional hazard model to evaluate the associations between the occupational class and study outcomes after ischemic stroke.

Results: Within 12 months after ischemic stroke, there were 106 (7.5%) cardiovascular events and 69 (4.9%) all-cause deaths. The Kaplan-Meier plots showed that white-collar workers had highest risk of cardiovascular events after 12-month follow-up (Log-rank P = 0.02). Multivariate adjusted hazard ratio and 95% confidence intervals (CIs) of farmers versus white-collar workers was 0.43(0.20-0.91) for cardiovascular events. No significant difference showed in blue-collar workers versus white-collar workers, with fully adjusted hazard ratio 0.62(95% CIs, 0.23-1.67).

Conclusions: Compared with white-collar workers, farmers are associated with less risk of cardiovascular events at 12 months after ischemic stroke, while there are no significant differences in blue-collar workers.
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http://dx.doi.org/10.1186/s12889-021-11624-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8377846PMC
August 2021

Kazak faecal microbiota transplantation induces short-chain fatty acids that promote glucagon-like peptide-1 secretion by regulating gut microbiota in mice.

Pharm Biol 2021 Dec;59(1):1077-1087

Department of Pharmacology, Xinjiang Medical University, Urumqi, China.

Context: Faecal microbiota transplantation (FMT) from Kazak individuals with normal glucose tolerance (KNGT) significantly reduces plasma glycolipid levels in type 2 diabetes mellitus mice. However, the mechanism behind this effect has not been reported.

Objective: To study the mechanism of improved glycolipid disorders in mice by FMT from a KNGT donor.

Materials And Methods: The normal diet group consisted of mice orally administered 0.2 mL phosphate buffer saline (PBS) (). For the (Vehicle) and (FMT intervention group) groups, mice received oral 0.2 mL PBS or faecal microorganisms from a KNGT donor, respectively. All mice were treated daily for 0, 6 or 10 weeks. Faecal DNA samples were sequenced and quantified using 16S rRNA gene sequencing and RT-qPCR, respectively. Short-chain fatty acid (SCFA) levels in the mouse faeces were determined by gas chromatography. G protein-coupled receptor 43 (GPR43) and glucagon-like peptide-1 (GLP-1) expression levels were determined.

Results: FMT intervention significantly increased the relative abundance of (0.038%,  < 0.05). levels (LogSQ) were increased ( < 0.01), while levels (LogSQ) were decreased ( < 0.01). Acetate and butyrate levels in the faeces were significantly increased (acetate; butyrate: 22.68 ± 1.82 mmol/L; 4.13 ± 1.09 mmol/L,  < 0.05). GPR43 mRNA expression and GLP-1 protein expression increased in colon tissue ( < 0.05).

Discussion And Conclusions: Mechanistically, FMT-KNGT could improve glycolipid disorders by changing the bacterial composition responsible for producing SCFAs and activating the GPR43/GLP-1 pathway.
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http://dx.doi.org/10.1080/13880209.2021.1954667DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8366640PMC
December 2021

Impact of MtrA on phosphate metabolism genes and the response to altered phosphate conditions in Streptomyces.

Environ Microbiol 2021 Aug 14. Epub 2021 Aug 14.

The State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.

Phosphate metabolism is known to be regulated by the PhoPR regulatory system in Streptomyces and some other bacteria. In this study, we report that MtrA also regulates phosphate metabolism in Streptomyces. Our data showed that, in Streptomyces coelicolor, MtrA regulates not only phosphate metabolism genes such as phoA but also phoP under different phosphate conditions, including growth on rich complex media without added inorganic phosphate and on defined media with low or high concentrations of inorganic phosphate. Cross-regulation was also observed among mtrA, phoP and glnR under these conditions. We demonstrated both in vitro and in vivo binding of MtrA to the promoter regions of genes associated with phosphate metabolism and to the intergenic region between phoR and phoU, indicating that these phosphate metabolism genes are targets of MtrA. We further showed that MtrA in S. lividans and S. venezuelae has detectable regulatory effects on expression of phosphate metabolism genes. Additionally, the MtrA homologue from Corynebacterium glutamicum bound predicted MtrA sites of multiple phosphate metabolism genes, implying its potential for regulating phosphate metabolism in this species. Overall, our findings support MtrA as a major regulator for phosphate metabolism in Streptomyces and also potentially in other actinobacteria.
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http://dx.doi.org/10.1111/1462-2920.15719DOI Listing
August 2021

SNARE proteins VAMP721 and VAMP722 mediate the post-Golgi trafficking required for auxin-mediated development in Arabidopsis.

Plant J 2021 Aug 3. Epub 2021 Aug 3.

Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.

The plant hormone auxin controls many aspects of plant development. Membrane trafficking processes, such as secretion, endocytosis and recycling, regulate the polar localization of auxin transporters in order to establish an auxin concentration gradient. Here, we investigate the function of the Arabidopsis thaliana R-SNAREs VESICLE-ASSOCIATED MEMBRANE PROTEIN 721 (VAMP721) and VAMP722 in the post-Golgi trafficking required for proper auxin distribution and seedling growth. We show that multiple growth phenotypes, such as cotyledon development, vein patterning and lateral root growth, were defective in the double homozygous vamp721 vamp722 mutant. Abnormal auxin distribution and root patterning were also observed in the mutant seedlings. Fluorescence imaging revealed that three auxin transporters, PIN-FORMED 1 (PIN1), PIN2 and AUXIN RESISTANT 1 (AUX1), aberrantly accumulate within the cytoplasm of the double mutant, impairing the polar localization at the plasma membrane (PM). Analysis of intracellular trafficking demonstrated the involvement of VAMP721 and VAMP722 in the endocytosis of FM4-64 and the secretion and recycling of the PIN2 transporter protein to the PM, but not its trafficking to the vacuole. Furthermore, vamp721 vamp722 mutant roots display enlarged trans-Golgi network (TGN) structures, as indicated by the subcellular localization of a variety of marker proteins and the ultrastructure observed using transmission electron microscopy. Thus, our results suggest that the R-SNAREs VAMP721 and VAMP722 mediate the post-Golgi trafficking of auxin transporters to the PM from the TGN subdomains, substantially contributing to plant growth.
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http://dx.doi.org/10.1111/tpj.15450DOI Listing
August 2021

Worker health risk of heavy metals in pellets of recycled plastic: a skin exposure model.

Int Arch Occup Environ Health 2021 Oct 20;94(7):1581-1589. Epub 2021 Jul 20.

School of Civil and Resource Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian, Beijing, 100083, China.

Objective: According to epidemiological studies, heavy metals such as arsenic, cadmium, chromium, and lead are "known" carcinogenic substances. After recycling, these metals remain in processed plastics. The purpose of this study was to assess the health risks of heavy metal skin exposure to workers in facilities that recycle plastics.

Methods: We used inductively coupled plasma-mass spectrometry to measure the dissolution concentrations of heavy metals in artificial sweat. Twenty-five samples of pellets of recycled plastic were examined, which were composed variously of polypropylene, high-density polyethylene, acrylonitrile-butadiene-styrene copolymer, high impact polystyrene, and polyamide. In addition, we used a "two-step assessment model," divided into exposure and risk characterization, to evaluate the health risks of heavy metal exposure in a simulated exposure environment of pellets of a recycled plastic processing workshop.

Results: Except for chromium (92%), the detection of lead, cadmium and arsenic was 100% in 25 samples of pellets of recycled plastic. The possible carcinogenic risk levels of As and Cr were, respectively, 2 and 38 times greater than the unacceptable risk level of 10 proposed by the US EPA. In addition, arsenic had the highest noncarcinogenic risk of 1.381 × 10, which was in the potential risk range of 10-10 proposed by the US EPA.

Conclusion: We found clear exposure-risk associations between heavy metals (lead, cadmium, chromium, arsenic) and worker health. Particularly, we found workers exposed to As and Cr were more likely to incur cancer.
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http://dx.doi.org/10.1007/s00420-021-01727-6DOI Listing
October 2021

A Comparison of Transvaginal Removal and Repair of Uterine Defect for Type II Cesarean Scar Pregnancy and Uterine Artery Embolization Combined With Curettage.

Front Med (Lausanne) 2021 22;8:654956. Epub 2021 Jun 22.

Department of Gynecology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China.

There is no consensus on a standardized therapy for type II cesarean scar pregnancy (CSP II). The objective of the present study was to evaluate the efficacy and safety and compare costs associated with transvaginal removal and repair (TRR) of uterine defect for CSP II to those of uterine artery embolization (UAE) and curettage. We conducted a retrospective study that included 87 patients diagnosed with CSP II and treated by performing UAE in combination with curettage and hysteroscopy ( = 53), or TRR ( = 34). Clinical data and outcomes were analyzed. UAE and TRR groups exhibited similar success rates. The TRR group had significantly lower complication rates (30.19 vs. 8.82%, < 0.05) and lower total costs (13,765.89 ± 2,029.12 vs. 9,063.82 ± 954.67, < 0.05) than the UAE group. The anterior myometrium of the lower uterine segment was relatively thicker after performing TRR, and no patient suffered from recurrent CSP II. The proportion of patients in the TRR group who had full-term delivery without uterine rupture was 88.24% (30/34), while four patients failed to pregnancy. TRR is a safe and effective treatment method for patients with CSP II and presents a highly cost-effective outcome, especially for patients with future fertility desire.
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http://dx.doi.org/10.3389/fmed.2021.654956DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8258109PMC
June 2021

Genomic analysis of Shiga toxin-producing Escherichia coli O157:H7 from cattle and pork-production related environments.

NPJ Sci Food 2021 Jul 1;5(1):15. Epub 2021 Jul 1.

Agriculture and Agri-Food Canada, Lacombe, Alberta, Canada.

Three E. coli O157:H7 outbreaks have been attributed to contaminated pork in Alberta, Canada, recently. This study investigates the phylogenetic relatedness of E. coli O157:H7 from pigs, cattle, and pork-production environments for source attribution. Limited strain diversity was observed using five conventional subtyping methods, with most or all strains being in one subgroup. Whole-genome single nucleotide polymorphism analysis confirmed the recent ancestry of the isolates from all three sources. Most environmental isolates clustered closer with pig isolates than cattle isolates. Also, a direct link was observed between 2018-outbreak environmental isolates and isolates collected from a pig farm in 2018. The majority of pig isolates harbor only one Shiga toxin gene, stx, while 70% (35/50) of the cattle isolates have both stx and stx. The results show some E. coli O157:H7 strains could establish persistence on pig farms and as such, pigs can be a significant source of the organism.
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http://dx.doi.org/10.1038/s41538-021-00097-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8249597PMC
July 2021

Boosting the synthesis of value-added aromatics directly from syngas a CrO and Ga doped zeolite capsule catalyst.

Chem Sci 2021 Apr 26;12(22):7786-7792. Epub 2021 Apr 26.

Department of Applied Chemistry, Graduate School of Engineering, University of Toyama Gofuku 3190 Toyama 930-8555 Japan

Even though the transformation of syngas into aromatics has been realized a methanol-mediated tandem process, the low product yield is still the bottleneck, limiting the industrial application of this technology. Herein, a tailor-made zeolite capsule catalyst with Ga doping and SiO coating was combined with the methanol synthesis catalyst CrO to boost the synthesis of value-added aromatics, especially -xylene, from syngas. Multiple characterization studies, control experiments, and density functional theory (DFT) calculation results clarified that Ga doped zeolites with strong CO adsorption capability facilitated the transformation of the reaction intermediate methanol by optimizing the first C-C coupling step under a high-pressure CO atmosphere, thereby driving the reaction forward for aromatics synthesis. This work not only reveals the synergistic catalytic network in the tandem process but also sheds new light on principles for the rational design of a catalyst in terms of oriented conversion of syngas.
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http://dx.doi.org/10.1039/d1sc01859kDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8188606PMC
April 2021

A Bacteriophage DNA Mimic Protein Employs a Non-specific Strategy to Inhibit the Bacterial RNA Polymerase.

Front Microbiol 2021 2;12:692512. Epub 2021 Jun 2.

BioBank, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.

DNA mimicry by proteins is a strategy that employed by some proteins to occupy the binding sites of the DNA-binding proteins and deny further access to these sites by DNA. Such proteins have been found in bacteriophage, eukaryotic virus, prokaryotic, and eukaryotic cells to imitate non-coding functions of DNA. Here, we report another phage protein Gp44 from bacteriophage SPO1 of , employing mimicry as part of unusual strategy to inhibit host RNA polymerase. Consisting of three simple domains, Gp44 contains a DNA binding motif, a flexible DNA mimic domain and a random-coiled domain. Gp44 is able to anchor to host genome and interact bacterial RNA polymerase the β and β' subunit, resulting in bacterial growth inhibition. Our findings represent a non-specific strategy that SPO1 phage uses to target different bacterial transcription machinery regardless of the structural variations of RNA polymerases. This feature may have potential applications like generation of genetic engineered phages with Gp44 gene incorporated used in phage therapy to target a range of bacterial hosts.
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http://dx.doi.org/10.3389/fmicb.2021.692512DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8208478PMC
June 2021

Probiotics alleviate adipose inflammation in high-fat diet-induced obesity by restoring adipose invariant natural killer T cells.

Nutrition 2021 09 25;89:111285. Epub 2021 Apr 25.

Department of Endocrinology and Metabolism, First Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, Xinjiang, China.

Objective: Invariant natural killer T (iNKT) cells, which are depleted in obese individuals, play important roles in preventing diet-induced obesity and associated disorders. Probiotic supplementation can alter the gut microbiota and immunomodulation in obesity. However, it remains unclear whether probiotics can affect visceral adipose iNKT cells. The aim of this study was to analyze the effects of probiotics on adipose iNKT cells in mice with high-fat diet (HFD)-induced obesity and to assess the immunomodulatory function of probiotics and their role in obesity, glucose tolerance, lipid metabolism, insulin resistance, and adipose inflammation.

Methods: Wildtype (WT) male C57BL/6 mice and CD1d knockout mice were fed an HFD or a normal-fat diet. Some mice received active or heat-sacrificed VSL#3 probiotics. Preventative VSL#3 therapy was also administered to HFD mice. Body weight, metabolic parameters, expression of genes encoding adipose inflammatory factors (interleukin [IL]-4, IL-10, tumor necrosis factor-α, interferon-γ, and IL-6), adipose iNKT cell frequency, and subphenotype were evaluated.

Results: HFD induced more severe obesity in CD1dKO mice than in WT mice. VSL#3 intervention significantly improved HFD-induced weight gain, adipose iNKT cell depletion, and metabolic and adipose inflammatory profiles in WT mice, but not in CD1dKO mice. Preventative VSL#3 treatment improved HFD-induced obesity and metabolic parameters, and elevated total adipose iNKT and IL-4 iNKT cell frequencies.

Conclusions: Probiotic intervention alleviated weight gain, improved metabolic parameters, and reduced adipose inflammation in HFD-induced obesity. These effects seem to depend on the restoration of visceral adipose iNKT cells. These findings have potential implications for the management of obesity-related diseases.
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http://dx.doi.org/10.1016/j.nut.2021.111285DOI Listing
September 2021

Integrating longitudinal clinical laboratory tests with targeted proteomic and transcriptomic analyses reveal the landscape of host responses in COVID-19.

Cell Discov 2021 Jun 8;7(1):42. Epub 2021 Jun 8.

Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.

The pathophysiology of coronavirus disease 19 (COVID-19) involves a multitude of host responses, yet how they unfold during the course of disease progression remains unclear. Here, through integrative analysis of clinical laboratory tests, targeted proteomes, and transcriptomes of 963 patients in Shanghai, we delineate the dynamics of multiple circulatory factors within the first 30 days post-illness onset and during convalescence. We show that hypercortisolemia represents one of the probable causes of acute lymphocytopenia at the onset of severe/critical conditions. Comparison of the transcriptomes of the bronchoalveolar microenvironment and peripheral blood indicates alveolar macrophages, alveolar epithelial cells, and monocytes in lungs as the potential main sources of elevated cytokines mediating systemic immune responses and organ damages. In addition, the transcriptomes of patient blood cells are characterized by distinct gene regulatory networks and alternative splicing events. Our study provides a panorama of the host responses in COVID-19, which may serve as the basis for developing further diagnostics and therapy.
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http://dx.doi.org/10.1038/s41421-021-00274-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8185699PMC
June 2021

Loss of immobilized water and intense protein aggregation responsible for quality deterioration of ready to eat firm tofu.

J Texture Stud 2021 08 18;52(4):492-500. Epub 2021 Jun 18.

School of Food and Biological Engineering, Hefei University of Technology, Hefei, China.

The influence of high-temperature treatment (100-120°C, 15 min) on the texture, color, and water-holding capacity of tofu gels was investigated. As the temperature increasing, the hardness and chewiness as well as the values of redness a and yellowness b increased gradually, while the water content and the lightness L value reduced progressively, and these variations were more pronounced at 115 or 120°C. Low field nuclear magnetic resonance showed that the loss of T water led to the decrease of the water content. Scanning electron microscope revealed that the micropore in gels decreased after heating, and almost entirely disappeared at 120°C. Further analysis by SDS-PAGE indicated the soy protein aggregation formed via disulfide linkage was observed in the thermal treated tofu gels, and nondisulfide linkage might also be occurred as temperature reached 110°C or higher. The quality deterioration may be attributed to immobilized water loss combined with the protein aggregation.
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http://dx.doi.org/10.1111/jtxs.12614DOI Listing
August 2021

The feasibility of phage therapy for periodontitis.

Future Microbiol 2021 06 8;16:649-656. Epub 2021 Jun 8.

Department of Periodontics, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou Key laboratory of Basic & Applied Research of Oral Regenerative Medicine, Guangzhou, Guangdong, 510182, China.

Periodontitis, a chronic progressive inflammation caused by plaque biofilm, is the main cause of tooth loss in adults. For certain refractory periodontitis cases, it is difficult to achieve a good curative effect using the existing periodontal treatment approaches, which may be due to periodontal pathogenic mechanism in the affected periodontal tissue that the host cannot resist and eliminate. Various pieces of evidence collectively revealed that most studies are focusing on phages in periodontal disease. Several studies have reported periodontitis treatment using phage therapy, highlighting its features including specificity, rapid propagation, and effectiveness on bacteriophage biofilms. In this study, we focus on these reports, aiming to lay the foundation for improved periodontal treatment approaches.
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http://dx.doi.org/10.2217/fmb-2020-0161DOI Listing
June 2021

Profiling of Brevetoxin Metabolites Produced by 165 Based on Liquid Chromatography-Mass Spectrometry.

Toxins (Basel) 2021 05 14;13(5). Epub 2021 May 14.

CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.

In this study, 165 ( 165), a Chinese strain, was used to research brevetoxin (BTX) metabolites. The sample pretreatment method for the enrichment of BTX metabolites in an algal culture medium was improved here. The method for screening and identifying intracellular and extracellular BTX metabolites was established based on liquid chromatography-time-of-flight mass spectrometry (LC-ToF-MS) and liquid chromatography triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS). The results show that the recovery rates for BTX toxins enriched by a hydrophilic-lipophilic balance (HLB) extraction column were higher than those with a C18 extraction column. This method was used to analyze the profiles of extracellular and intracellular BTX metabolites at different growth stages of 165. This is the first time a Chinese strain of has been reported that can produce toxic BTX metabolites. Five and eight kinds of BTX toxin metabolites were detected in the cell and culture media of 165, respectively. Brevenal, a toxic BTX metabolite antagonist, was found for the first time in the culture media. The toxic BTX metabolites and brevenal in the 165 cell and culture media were found to be fully proven in terms of the necessity of establishing a method for screening and identifying toxic BTX metabolites. The results found by qualitatively and quantitatively analyzing BTX metabolites produced by 165 at different growth stages show that the total toxic BTX metabolite contents in single cells ranged between 6.78 and 21.53 pg/cell, and the total toxin concentration in culture media ranged between 10.27 and 449.11 μg/L. There were significant differences in the types and contents of toxic BTX metabolites with varying growth stages. Therefore, when harmful algal blooms occur, the accurate determination of BTX metabolite types and concentrations will be helpful to assess the ecological disaster risk in order to avoid hazards and provide appropriate disaster warnings.
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http://dx.doi.org/10.3390/toxins13050354DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8156667PMC
May 2021

Changes in carbon and nitrogen metabolism during seawater-induced mortality of Picea sitchensis trees.

Tree Physiol 2021 May 20. Epub 2021 May 20.

Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, Washington.

Increasing seawater exposure is causing mortality of coastal forests, yet the physiological response associated with seawater-induced tree mortality, particularly in non-halophytes, is poorly understood. We investigated the shifts in carbon and nitrogen metabolism of mature Sitka-spruce trees that were dying after an ecosystem-scale manipulation of tidal seawater exposure. Soil porewater salinity and foliar ion concentrations increased after seawater exposure and were strongly correlated with the percentage of live foliated crown (PLFC; e.g., crown 'greenness', a measure of progression to death). Co-occurring with decreasing PLFC was decreasing photosynthetic capacity, N-investment into photosynthesis, N-resorption efficiency, and non-structural carbohydrate (NSC, soluble sugars and starch) concentrations, with the starch reserves depleted to near zero when PLFC dropped below 5%. Combined with declining PLFC, these changes subsequently decreased total carbon gain and thus exacerbated the carbon starvation process. This study suggests that an impairment in carbon and N metabolism during the mortality process after seawater exposure is associated with the process of carbon starvation, and provides critical knowledge necessary to predict sea-level rise impacts on coastal forests.
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http://dx.doi.org/10.1093/treephys/tpab073DOI Listing
May 2021
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