[Characterization of Microplastic Surface Bacterial Community Structure and Prediction of Ecological Risk in Poyang Lake, China].

In recent years, the environmental pollution of microplastics in Poyang Lake has received increasing attention. Baisha Lake of Poyang Lake was selected as the study area, and samples of water and sediments of Baisha Lake and the microplastics therein were collected, and the polymer types of microplastics were identified as polyethylene (PE), polyester (PET), polypropylene (PP), and polystyrene (PS) using Fourier infrared spectroscopy. We also analyzed the structural composition of bacterial communities in water, in sediments, and on microplastic surfaces using 16S high-throughput sequencing. The species richness and diversity of bacteria on the microplastic surfaces were lower than those in the surrounding water and sediments. The results of NMDS analysis showed that the bacterial community structures on the microplastic surfaces differed greatly from those in the surrounding sediments and water. The bacterial community composition in water and sediment differed from that on the microplastic surfaces, and the dominant bacterial phyla on the microplastic surfaces were Proteobacteria and Bacteroidota, and their relative abundance on the microplastic surfaces was higher than that in sediment. The relative abundance of Proteobacteria was higher than that in water. The relative abundances of Bacteroidota and Actinobacteriota were significantly lower than that of water. Massilia and Pseudomonas were the dominant genera on the microplastic surfaces, and their relative abundances were significantly higher than those in the surrounding water and sediments. BugBase phenotype prediction revealed that the relative abundance of contains mobile elements, biofilm formation, potential pathogenicity, and stress tolerance phenotypes of microplastic bacterial communities were significantly higher than those of the surrounding water and sediments. The results revealed that microplastics may have contributed to the spread of harmful bacteria, including pathogenic bacteria, and increased the potential pathogenicity of bacterial communities. Additionally, microplastic surface bacterial communities had higher phenotypes of mobile gene element content. Revealing the potential harm of microplastic pollution to wetland ecology at the micro level may provide a scientific reference for maintaining the ecological stability of wetlands.

Towards an E-nose: Metal-organic frameworks based quartz crystal microbalance array for fruit ripeness indexing.

Ethylene is a hormone for fruit ripening control, and for the purpose of maintaining plant quality, ethylene monitoring is crucial. Due to the simple structure and limited functionality, the technical realization of ethylene detection by an artificial sensor remains a challenge. In this paper, we present a metal-organic frameworks (MOFs) array based electronic nose (e-nose) for rapid and accurate determination of ethylene. Six zirconium-based MOFs with systematically modified pore sizes and π-π binding sites have been prepared and fabricated into a sensor array using quartz crystal microbalance (QCM) technology. By virtue of the synergistic features of six MOF sensors, selectivity detection of ethylene has been achieved. The detection limit reaches to 0.27 ± 0.02 ppm, and high selectivity and stability (98.29 % ± 0.88 %) could also be confirmed. By submitting data to machine learning algorithm, an e-nose system could be established for discriminating ethylene from mixtures with a qualitative accuracy of 90.30 % and quantitative accuracy of 98.89 %. Practical evaluation suggests that the e-nose could index the fruit quality based on the accurate detection of ethylene released during fruit ripeness. This work demonstrates the promising potential of fabricating MOFs based e-nose systems for practical monitoring applications by selectively detecting challengeable target molecules.

Metatranscriptome of human lung microbial communities in a cohort of mechanically ventilated COVID-19 Omicron patients.

The Omicron variant of the severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) infected a substantial proportion of Chinese population, and understanding the factors underlying the severity of the disease and fatality is valuable for future prevention and clinical treatment. We recruited 64 patients with invasive ventilation for COVID-19 and performed metatranscriptomic sequencing to profile host transcriptomic profiles, plus viral, bacterial, and fungal content, as well as virulence factors and examined their relationships to 28-day mortality were examined. In addition, the bronchoalveolar lavage fluid (BALF) samples from invasive ventilated hospital/community-acquired pneumonia patients (HAP/CAP) sampled in 2019 were included for comparison. Genomic analysis revealed that all Omicron strains belong to BA.5 and BF.7 sub-lineages, with no difference in 28-day mortality between them. Compared to HAP/CAP cohort, invasive ventilated COVID-19 patients have distinct host transcriptomic and microbial signatures in the lower respiratory tract; and in the COVID-19 non-survivors, we found significantly lower gene expressions in pathways related viral processes and positive regulation of protein localization to plasma membrane, higher abundance of opportunistic pathogens including bacterial Alloprevotella, Caulobacter, Escherichia-Shigella, Ralstonia and fungal Aspergillus sydowii and Penicillium rubens. Correlational analysis further revealed significant associations between host immune responses and microbial compositions, besides synergy within viral, bacterial, and fungal pathogens. Our study presents the relationships of lower respiratory tract microbiome and transcriptome in invasive ventilated COVID-19 patients, providing the basis for future clinical treatment and reduction of fatality.

Sex- and reproductive status-specific relationships between body composition and non-alcoholic fatty liver disease.

BACKGROUND: Sex and reproductive status differences exist in both non-alcoholic fatty liver disease (NAFLD) and body composition. Our purpose was to investigate the relationship between body composition and the severity of liver steatosis and fibrosis in NAFLD in different sex and reproductive status populations. METHODS: This cross-sectional study included 880 patients (355 men, 417 pre-menopausal women, 108 post-menopausal women). Liver steatosis and fibrosis and body composition data were measured using FibroScan and a bioelectrical impedance body composition analyzer (BIA), respectively, and the following parameters were obtained: liver stiffness measurement (LSM), controlled attenuation parameter (CAP), waist circumference (WC), body mass index (BMI), percent body fat (PBF), visceral fat area (VFA), appendicular skeletal muscle mass (ASM), appendicular skeletal muscle mass index (ASMI), fat mass (FM), fat free mass (FFM), and FFM to FM ratio (FFM/FM). Multiple ordinal logistic regression (MOLR) was used to analyze the independent correlation between body composition indicators and liver steatosis grade and fibrosis stage in different sex and menopausal status populations. RESULTS: Men had higher WC, ASM, ASMI, FFM, and FFM/FM than pre- or post-menopausal women, while pre-menopausal women had higher PBF, VFA, and FM than the other two groups (p < 0.001). Besides, men had greater CAP and LSM values (p < 0.001). For MOLR, after adjusting for confounding factors, WC (OR, 1.07; 95% CI, 1.02-1.12; P = 0.011) and FFM/FM (OR, 0.52; 95% CI, 0.31-0.89; P = 0.017) in men and visceral obesity (OR, 4.16; 95% CI, 1.09-15.90; P = 0.037) in post-menopausal women were independently associated with liver steatosis grade. WC and visceral obesity were independently associated with liver fibrosis stage in men (OR, 1.05; 95% CI, 1.01-1.09, P = 0.013; OR, 3.92; 95% CI, 1.97-7.81; P < 0.001, respectively). CONCLUSIONS: Increased WC and low FFM/FM in men and visceral obesity in post-menopausal women were independent correlates of more severe liver steatosis. In addition, increased WC and visceral obesity were independent correlates of worse liver fibrosis in men. These data support the sex- and reproductive status-specific management of NAFLD.

Creation of Environmentally Friendly Super "Dinitrotoluene Scavenger" Plants.

Pervasive environmental contamination due to the uncontrolled dispersal of 2,4-dinitrotoluene (2,4-DNT) represents a substantial global health risk, demanding urgent intervention for the removal of this detrimental compound from affected sites and the promotion of ecological restoration. Conventional methodologies, however, are energy-intensive, susceptible to secondary pollution, and may inadvertently increase carbon emissions. In this study, a 2,4-DNT degradation module is designed, assembled, and validated in rice plants. Consequently, the modified rice plants acquire the ability to counteract the phytotoxicity of 2,4-DNT. The most significant finding of this study is that these modified rice plants can completely degrade 2,4-DNT into innocuous substances and subsequently introduce them into the tricarboxylic acid cycle. Further, research reveals that the modified rice plants enable the rapid phytoremediation of 2,4-DNT-contaminated soil. This innovative, eco-friendly phytoremediation approach for dinitrotoluene-contaminated soil and water demonstrates significant potential across diverse regions, substantially contributing to carbon neutrality and sustainable development objectives by repurposing carbon and energy from organic contaminants.

Bacterial community structure of water, sediment and microplastics in Poyang Lake wetland.

As a new type of pollutant, microplastics accumulate continuously in the environment. The environmental problems caused by microplastics have attracted wide attention. In this study, we collected water, sediment and four types of microplastics (film, foam, fiber and fragment) from wetland in East Lake area of Poyang Lake. We used high-throughput sequencing technology to analyze the bacterial diversity and community structure of water, sediment, and microplastics surface. The results showed that the bacterial richness and diversity of water and sediment were significantly higher than that on microplastics, and the bacterial richness of foaming microplastics was significantly lower than that of the other three types of microplastics. There were significant differences of bacterial communities between water, sediment, and microplastics. There were significant differences cross different types of microplastics. Proteobacteria, Bacteroidetes, and Actinobacteria were the main bacterial communities of water, sediment, and microplastics. The relative abundance of Bacteroidetes and Actinobacteria in water was higher than that in sediments and microplastics, while the relative abundance of Bacteroidetes and Actinobacteria in foaming microplastics was higher than that in other three types. At the genus level, the dominant ones included Massilia, Flavobacteria, and Pseudomonas. The relative abundance of Massilia and Pseudomonas in water and sediments was lower than that on microplastics, and the relative abundance of Flavobacteria was not different among water, sediment and microplastics. The relative abundance of Massilia in microplastics followed an order of fragment>fiber>film>foam, and that of Pseudomonas was film>fiber>foam>fragment. The results of metabolic pathway prediction analysis showed that except for foaming microplastics, the bacterial metabolic pathways on the surface of the other three types of microplastics were significantly different from those in water and sediment. The cellular processes, organismal systems, environmental information processing, and human diseases in bacterial metabolic pathways on microplastics surface were significantly higher than those in water and sediment. Our results suggested that microbial community structure on the surface of microplastics was significantly different from that in water and sediment, and that the morphology type of microplastics affected microbial community structure on the surface.

Functional screening and rational design of compounds targeting GPR132 to treat diabetes.

Chronic inflammation due to islet-residing macrophages plays key roles in the development of type 2 diabetes mellitus. By systematically profiling intra-islet lipid-transmembrane receptor signalling in islet-resident macrophages, we identified endogenous 9(S)-hydroxy-10,12-octadecadienoic acid-G-protein-coupled receptor 132 (GPR132)-Gi signalling as a significant contributor to islet macrophage reprogramming and found that GPR132 deficiency in macrophages reversed metabolic disorders in mice fed a high-fat diet. The cryo-electron microscopy structures of GPR132 bound with two endogenous agonists, N-palmitoylglycine and 9(S)-hydroxy-10,12-octadecadienoic acid, enabled us to rationally design both GPR132 agonists and antagonists with high potency and selectivity through stepwise translational approaches. We ultimately identified a selective GPR132 antagonist, NOX-6-18, that modulates macrophage reprogramming within pancreatic islets, decreases weight gain and enhances glucose metabolism in mice fed a high-fat diet. Our study not only illustrates that intra-islet lipid signalling contributes to islet macrophage reprogramming but also provides a broadly applicable strategy for the identification of important G-protein-coupled receptor targets in pathophysiological processes, followed by the rational design of therapeutic leads for refractory diseases such as diabetes.

Metabolic engineering of Escherichia coli for 2,4-dinitrotoluene degradation.

2,4-Dinitrotoluene (2,4-DNT) as a common industrial waste has been massively discharged into the environment with industrial wastewater. Due to its refractory degradation, high toxicity, and bioaccumulation, 2,4-DNT pollution has become increasingly serious. Compared with the currently available physical and chemical methods, in situ bioremediation is considered as an economical and environmentally friendly approach to remove toxic compounds from contaminated environment. In this study, we relocated a complete degradation pathway of 2,4-DNT into Escherichia coli to degrade 2,4-DNT completely. Eight genes from Burkholderia sp. strain were re-synthesized by PCR-based two-step DNA synthesis method and introduced into E. coli. Degradation experiments revealed that the transformant was able to degrade 2,4-DNT completely in 12 h when the 2,4-DNT concentration reached 3 mM. The organic acids in the tricarboxylic acid cycle were detected to prove the degradation of 2,4-DNT through the artificial degradation pathway. The results proved that 2,4-DNT could be completely degraded by the engineered bacteria. In this study, the complete degradation pathway of 2,4-DNT was constructed in E. coli for the first time using synthetic biology techniques. This research provides theoretical and experimental bases for the actual treatment of 2,4-DNT, and lays a technical foundation for the bioremediation of organic pollutants.

Prevalence and risk factors for colonisation and infection with carbapenem-resistant Enterobacterales in intensive care units: A prospective multicentre study.

OBJECTIVES: This study aimed to investigate the prevalence and risk factors for carbapenem-resistant Enterobacterales colonisation/infection at admission and acquisition among patients admitted to the intensive care unit. RESEARCH METHODOLOGY/DESIGN: A prospective and multicentre study. SETTING: This study was conducted in 24 intensive care units in Anhui, China. MAIN OUTCOME MEASURES: Demographic and clinical data were collected, and rectal carbapenem-resistant Enterobacterales colonisation was detected by active screening. Multivariate logistic regression models were used to analyse factors associated with colonisation/infection with carbapenem-resistant Enterobacterales at admission and acquisition during the intensive care unit stay. RESULTS: There were 1133 intensive care unit patients included in this study. In total, 5.9% of patients with carbapenem-resistant Enterobacterales colonisation/infection at admission, and of which 56.7% were colonisations. Besides, 8.5% of patients acquired carbapenem-resistant Enterobacterales colonisation/infection during the intensive care stay, and of which 67.6% were colonisations. At admission, transfer from another hospital, admission to an intensive care unit within one year, colonisation/infection/epidemiological link with carbapenem-resistant Enterobacterales within one year, and exposure to any antibiotics within three months were risk factors for colonisation/infection with carbapenem-resistant Enterobacterales. During the intensive care stay, renal disease, an epidemiological link with carbapenem-resistant Enterobacterales, exposure to carbapenems and beta-lactams/beta-lactamase inhibitors, and intensive care stay of three weeks or longer were associated with acquisition. CONCLUSION: The prevalence of colonisation/infection with carbapenem-resistant Enterobacterales in intensive care units is of great concern and should be monitored systematically. Particularly for the 8.5% prevalence of carbapenem-resistant Enterobacterales acquisition during the intensive care stay needs enhanced infection prevention and control measures in these setting. Surveillance of colonisation/infection with carbapenem-resistant Enterobacterales at admission and during the patient's stay represents an early identification tool to prevent further transmission of carbapenem-resistant Enterobacterales. IMPLICATIONS FOR CLINICAL PRACTICE: Carbapenem-resistant Enterobacterales colonization screening at admission and during the patient's stay is an important tool to control carbapenem-resistant Enterobacterales spread in intensive care units.

Establishment of a chronic insomnia rat model of sleep fragmentation using unstable platforms surrounded by water.

Chronic fragmented sleep is a very common type of insomnia that affects the daily lives of numerous people around the world. However, its pathogenesis is not very clear and a corresponding rat model has not been reported for this purpose at present. The present study aimed to establish a rat model of chronic insomnia with sleep fragmentation using self-made multiple strings of unstable platforms surrounded by shallow water. During the establishment of the models, changes in body weight and differences in food and water intake in the daytime and at night were acquired. The rat models were assessed using several tests, including the Morris water maze test, pentobarbital sodium-induced sleep, infrared monitoring and electroencephalogram/electromyography during sleep. The expression levels of certain inflammatory factors and orexin A were detected in the serum and brain tissues using ELISAs, immunohistochemistry and immunofluorescence. The expression levels of orexin 1 receptor (orexin 1r) were also detected in the brain. Polysomnography indicated that the model rats were successfully prepared with reduced non-rapid eye movement (non-REM) sleep in the daytime, which was increased at night, and considerably lower REM duration during the day and night. The number of instances of sleep arousals were also increased in the day and at night, and the average duration of each sleep bout was decreased in the daytime. The body weights of the model rats increased at a normal rate. However, the reduction of body weight in the daytime and increased in body weight at night were significantly less than those of the control rats. The daytime food and water consumption of the model rats increased significantly compared with that of the control rats, but was similar to that of the control group at night. The Morris water maze test indicated that the model rats were slow to learn to escape the platforms and performed a lower number of target crossings. The pentobarbital-induced sleep experiment confirmed that the model rats exhibited a longer sleep latency and shorter sleep time. The serum IL-1ß, IL-6, TNF-α and orexin A levels of the model rats were significantly increased, whereas their serum IL-10 levels were significantly decreased compared with those of the control rats. The expression levels of IL-1ß, IL-6, orexin A and orexin 1r in the brain tissues of the model rats were also significantly increased. In conclusion, these data indicate that learning and memory function, sleep time, arousal times, diurnal and nocturnal body weight changes, food and water intake, and expression levels of the specific inflammatory factors orexin A and orexin 1r were altered in the model rats. This suggests the chronic insomnia rat model with sleep fragmentation was successfully established using multiple strings of unstable platforms surrounded by water.

[Stable Expression of Coagulation Factors by RPS6 Promoter].

OBJECTIVE: To screen better promoters and provide more powerful tools for basic research and gene therapy of hemophilia. METHODS: Bioinformatics methods were used to analyze the promoters expressing housekeeping genes with high abundance, so as to select potential candidate promoters. The GFP reporter gene vector was constructed, and the packaging efficiency of the novel promoter was investigated with EF1 α promoter as control, and the transcription and activities of the reporter gene were investigated too. The activity of the candidate promoter was investigated by loading F9 gene. RESULTS: The most potential RPS6 promoter was obtained by screening. There was no difference in lentiviral packaging between EF1 α-LV and RPS6-LV, and their virus titer were consistent. In 293T cells, the transduction efficiency and mean fluorescence intensity of RPS6pro-LV and EF1 αpro-LV were proportional to the lentiviral dose. The transfection efficiency of both promoters in different types of cells was in the following order: 293T>HEL>MSC; Compared with EF1 αpro-LV, RPS6pro-LV could obtain a higher fluorescence intensity in MSC cells, and RPS6pro-LV was more stable in long-term cultured HEL cells infected with two lentiviruses respectively. The results of RT-qPCR, Western blot and FIX activity (FIX∶C) detection of K562 cell culture supernatant showed that FIX expression in the EF1 α-F9 and RPS6-F9 groups was higher than that in the unloaded control group, and there was no significant difference in FIX expression between the EF1 α-F9 and RPS6-F9 groups. CONCLUSION: After screening and optimization, a promoter was obtained, which can be widely used for exogenous gene expression. The high stability and viability of the promoter were confirmed by long-term culture and active gene expression, which providing a powerful tool for basic research and clinical gene therapy of hemophilia.

Fischer's base-triggered formal (3+2) cycloadditions with 3-isothiocyanato oxindoles as acceptor-donor synthons.

Herein, previously unreported Fischer's base reactants serving as useful 2C building blocks in (3+2) cycloaddition reactions to build a library of bispiro[Fischer's base-oxindole] hybrids are described. These structurally intriguing products containing three adjacent quaternary stereocentres were smoothly afforded in up to 82% yield and >20 : 1 dr under catalyst-free conditions. Notably, the present protocol firstly employs 3-isothiocyanato oxindole serving as an acceptor and then as a donor in the formal (3+2) cycloadditions, allowing practical, straightforward access to structurally diverse cycloadducts. This work expands the applicability scope of 3-isothiocyanato oxindoles, which have been limited to behaving as donor/acceptor-based synthons in cycloadditions in previous work.

Corrigendum: Platelet abnormalities in autoimmune thyroid diseases: A systematic review and meta-analysis.

[This corrects the article DOI: 10.3389/fimmu.2022.1089469.].

Complete biodegradation of the oldest organic herbicide 2,4-Dichlorophenoxyacetic acid by engineering Escherichia coli.

After nearly 80 years of extensive application, the oldest organic herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has caused many problems of environmental pollution and ecological deterioration. Bioremediation is an ideal method for pollutant treatment. However, difficult screening and preparation of efficient degradation bacteria have largely hindered its application in 2,4-D remediation. We have created a novel engineering Escherichia coli with a reconstructed complete degradation pathway of 2,4-D to solve the problem of screening highly efficient degradation bacteria in this study. The results of fluorescence quantitative PCR demonstrated that all nine genes in the degradation pathway were successfully expressed in the engineered strain. The engineered strains can quickly and completely degrade 0.5 mM 2, 4-D within 6 h. Inspiring, the engineered strains grew with 2,4-D as the sole carbon source. By using the isotope tracing method, the metabolites of 2,4-D were found incorporated into the tricarboxylic acid cycle in the engineering strain. Scanning electron microscopy showed that 2,4-D had less damage on the engineered bacteria than the wild-type strain. Engineered strain can also rapidly and completely remedy 2,4-D pollution in natural water and soil. Assembling the metabolic pathways of pollutants through synthetic biology was an effective method to create pollutant-degrading bacteria for bioremediation.

Prognostic implication of early posttransplant hypercholesterolemia in liver transplantation for patients with hepatocellular carcinoma.

BACKGROUND: Hyperlipidemia is a common complication after liver transplantation (LT) and develops mostly in the early posttransplant period. Recently, some studies have reported a positive correlation between hyperlipidemia and favorable prognosis in patients with hepatocellular carcinoma (HCC) undergoing hepatectomy. This study aimed to evaluate the possibility of predicting prognosis in HCC patients receiving LT by early posttransplant dyslipidemia. METHODS: From January 2015 to December 2017, a total of 806 HCC patients from China Liver Transplant Registry database were retrospectively enrolled. The prognostic relevance of early posttransplant hypertriglyceridemia or hypercholesterolemia was examined using survival analysis, and subgroup analysis was implemented based on LT criteria. RESULTS: Early posttransplant hypercholesterolemia (EPHC) was independently inversely associated with the risk of recurrence [hazard ratio (HR) = 0.630; P = 0.022], but was not significantly correlated with the mortality. However, early posttransplant hypertriglyceridemia was not related to prognosis. Intriguingly, with further classification, we found that borderline EPHC (B-EPHC), instead of significant EPHC, was a predictor of lower risk for both recurrence (HR = 0.504; P = 0.006) and mortality (HR = 0.511; P = 0.023). Compared with non-EPHC patients, B-EPHC patients achieved significantly superior 1-year and 3-year tumor-free survival (89.6% and 83.7% vs. 83.8% and 72.7% respectively; P = 0.023), and 1-year and 3-year overall survival (95.8% and 84.8% vs. 94.6% and 77.6% respectively; P = 0.039). In the subgroup analysis, B-EPHC remained an independent predictor of better prognosis in patients beyond Milan criteria and those within Hangzhou criteria; whereas there was no significant relationship between B-EPHC and prognosis in patients within Milan criteria and those beyond Hangzhou criteria. More interestingly, patients beyond Milan criteria but within Hangzhou criteria were identified as the crucial subpopulation who benefited from B-EPHC (recurrence HR = 0.306, P = 0.011; mortality HR = 0.325, P = 0.031). CONCLUSIONS: B-EPHC could assist transplant teams in dynamically evaluating prognosis after LT for HCC as a postoperative non-oncological biomarker, especially in patients beyond Milan criteria but within Hangzhou criteria.

Enantioselective Synthesis of Bispiro[indanedione-oxindole-cyclopropane]s through Organocatalytic [2+1] Cycloaddition.

A series of compounds featuring a novel bispiro[indanedione-oxindole-cyclopropane] moiety have been synthesized through a squaramide-catalyzed [2+1] cycloaddition reaction. The tandem Michael-alkylation reaction of 2-arylidene-1,3-indanediones with 3-bromooxindoles furnished the cycloadducts in high yields with excellent diastereo- and enantioselectivities. The ammonium ylide in the catalytic process, as a key intermediate, was revealed by the high-resolution mass spectrometry study.

Kidney Mesenchymal stem cells alleviate cisplatin-induced kidney injury and apoptosis in rats.

OBJECTIVE: This experiment was designed to demonstrate Mesenchymal stem cells (MSCs) derived from kidney can alleviate cisplatin-induced kidney injury and renal cell apoptosis through paracrine pathway. METHODS: Firstly, MSCs were isolated from kidney of young rats, and their surface-specific markers were identified by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and immunofluorescence staining. Self-renewal ability of Kidney Mesenchymal Stem Cells (KMSCs) was observed by cell counting and 5-Bromo-2'-deoxyuridine (BrdU) fluorescence staining. KMSCs at logarithmic growth stage were traced and injected into rat through tail vein. RESULTS: The results showed that KMSCs homed in the kidney tissues, decreased the secretion of inflammatory factors (CRP, TNFα, IL-1ß, IL-6), and alleviated renal function. Hematoxylin and Eosin (H＆E), Masson and Periodic Acid-silver Methenamine (PASM) staining showed that KMSCs could alleviate pathological damage in rats. Terminal Deoxynucleotidyl Transferase mediated dUTP Nick-End Labeling (TUNEL) assay showed that KMSCs could reduce the apoptosis of rat kidney cells induced by cisplatin. Finally, Immunohistochemistry (IHC) results showed that cisplatin could induce higher expression of the pro-apoptotic protein Bax and lower expression of anti-apoptotic Bcl-2 in kidney tissues. However, KMSCs could reverse the pro-apoptotic effect of cisplatin on kidney cells and improve the survival rate of rats. CONCLUSIONS: In conclusion, KMSCs were successfully isolated from kidney tissues, and KMSCs have therapeutic effects on rat kidney injury induced by cisplatin.

Genetic engineering of complex feed enzymes into barley seed for direct utilization in animal feedstuff.

Currently, feed enzymes are primarily obtained through fermentation of fungi, bacteria, and other microorganisms. Although the manufacturing technology for feed enzymes has evolved rapidly, the activities of these enzymes decline during the granulating process and the cost of application has increased over time. An alternative approach is the use of genetically modified plants containing complex feed enzymes for direct utilization in animal feedstuff. We co-expressed three commonly used feed enzymes (phytase, ß-glucanase, and xylanase) in barley seeds using the Agrobacterium-mediated transformation method and generated a new barley germplasm. The results showed that these enzymes were stable and had no effect on the development of the seeds. Supplementation of the basal diet of laying hens with only 8% of enzyme-containing seeds decreased the quantities of indigestible carbohydrates, improved the availability of phosphorus, and reduced the impact of animal production on the environment to an extent similar to directly adding exogenous enzymes to the feed. Feeding enzyme-containing seeds to layers significantly increased the strength of the eggshell and the weight of the eggs by 10.0%-11.3% and 5.6%-7.7% respectively. The intestinal microbiota obtained from layers fed with enzyme-containing seeds was altered compared to controls and was dominated by Alispes and Rikenella. Therefore, the transgenic barley seeds produced in this study can be used as an ideal feedstuff for use in animal feed.

Metabolic engineering of Escherichia coli for direct production of vitamin C from D-glucose.

BACKGROUND: Production of vitamin C has been traditionally based on the Reichstein process and the two-step process. However, the two processes share a common disadvantage: vitamin C cannot be directly synthesized from D-glucose. Therefore, significant effort has been made to develop a one-step vitamin C fermentation process. While, 2-KLG, not vitamin C, is synthesized from nearly all current one-step fermentation processes. Vitamin C is naturally synthesized from glucose in Arabidopsis thaliana via a ten-step reaction pathway that is encoded by ten genes. The main objective of this study was to directly produce vitamin C from D-glucose in Escherichia coli by expression of the genes from the A. thaliana vitamin C biosynthetic pathway. RESULTS: Therefore, the ten genes of whole vitamin C synthesis pathway of A. thaliana were chemically synthesized, and an engineered strain harboring these genes was constructed in this study. The direct production of vitamin C from D-glucose based on one-step fermentation was achieved using this engineered strain and at least 1.53 mg/L vitamin C was produced in shaking flasks. CONCLUSIONS: The study demonstrates the feasibility of one-step fermentation for the production of vitamin C from D-glucose. Importantly, the one-step process has significant advantages compared with the currently used fermentation process: it can save multiple physical and chemical steps needed to convert D-glucose to D-sorbitol; it also does not involve the associated down-streaming steps required to convert 2-KLG into vitamin C.

Construction of complete degradation pathway for nitrobenzene in Escherichia coli.

Nitrobenzene is widely present in industrial wastewater and soil. Biodegradation has become an ideal method to remediate organic pollutants due to its low cost, high efficiency, and absence of secondary pollution. In the present study, 10 exogenous genes that can completely degrade nitrobenzene were introduced into Escherichia coli, and their successful expression in the strain was verified by fluorescence quantitative polymerase chain reaction and proteomic analysis. The results of the degradation experiment showed that the engineered strain could completely degrade 4 mM nitrobenzene within 8 h. The formation of intermediate metabolites was detected, and the final metabolites entered the E. coli tricarboxylic acid cycle smoothly. This process was discovered by isotope tracing method. Results indicated the integrality of the degradation pathway and the complete degradation of nitrobenzene. Finally, further experiments were conducted in soil to verify its degradation ability and showed that the engineered strain could also degrade 1 mM nitrobenzene within 10 h. In this study, engineered bacteria that can completely degrade nitrobenzene have been constructed successfully. The construction of remediation-engineered bacteria by synthetic biology laid the foundation for the industrial application of biological degradation of organic pollutants.