High specific surface area carbon aerogel derived from starch for methylene blue adsorption and supercapacitors.

Starch based carbon aerogel has attracted significant attention due to the wide source, environmental friendliness and low price of raw materials. Here, starch based carbon aerogel was fabricated by graft reaction and cross-linking reaction of starch. The network structure of starch hydrogel was optimized through graft and cross-linking reaction. After freeze drying and high temperature carbonization, the obtained carbon aerogel that carbonized at 800 °C showed a specific surface area of 1508 m2·g-1 without activation which is far higher than that of other unactivated carbon aerogels. The starch based carbon aerogel carbonized at 800 °C exhibited superior methylene blue adsorption ability with a maximum adsorption capacity of 963.5 mg·g-1 as a result of its rich surface functional groups, high specific surface area, and reasonable pore size distribution. Furthermore, the carbon aerogel carbonized at 700 °C exhibited excellent electrochemical performance with a specific capacitance of 180.1 F·g-1 at a current density of 1 A·g-1as electrode materials for supercapacitors. Overall, this work provides a new method to prepare high performance starch based carbon aerogel.

Associations of sedentary behaviors with mental health outcomes in a cohort of patients with minor ischemic stroke.

OBJECTIVE: The relationship between sedentary behaviors and functional outcomes of acute ischemic stroke (AIS) has been previously reported. However, it remains unclear whether sedentary behaviors are associated with mental health outcomes in AIS patients. Therefore, the objective of this study was to investigate the mental health outcomes in patients with minor AIS one year after stroke onset. METHODS: This cross-sectional study recruited 1230 patients with minor AIS (NIHSS ≤ 5) from three hospitals in China. One year after discharge, patients were interviewed using face-to-face questionnaires, including the PHQ-9, GAD-7, and ISI, to assess symptoms of depression, anxiety, and insomnia, respectively. Participants were categorized into the long sedentary time group and the short sedentary time group based on the median sedentary time of all participants. The associations between leisure sedentary time and mental health outcomes were investigated. RESULTS: Participants with a long leisure sedentary time had higher PHQ-9, GAD-7, and ISI scores than those with a short sedentary time. Longer sedentary time was associated with an increased risk of experiencing symptoms of major depression (RR, 95% CI: 1.79, 1.47 to 2.18), anxiety (RR, 95% CI: 3.28, 2.08 to 5.18), and insomnia (RR, 95% CI: 2.58, 2.03 to 3.28) one year after a minor AIS. CONCLUSION: Excessive sedentary time is associated with long-term mental health conditions after stroke. Therefore, reducing the sedentary time might be helpful for preventing poststroke depression, anxiety, and insomnia.

Comparison of magnetoimpedance behaviors in meander CoFeNiSiB amorphous ribbon for deformation sensing applications.

In this work, micro-ribbon strips and meanders based on CoFeNiSiB amorphous ribbons were fabricated by using the lithography technique and chemical etching. Flat and curved holders with different radius of curvature were obtained via 3D printing techniques for GMI testing. Longitudinal and transverse GMI (LGMI and TGMI) behaviors of micro-ribbon sensors in different bending directions and degrees were systematically investigated. The results show the LGMI and TGMI effects of micro-ribbon meanders with one turn is most sensitive to bending. It can be used in the development of deformation sensors. In addition, there is a linear range of field in the LGMI and TGMI curves of micro ribbons under different bending conditions, and the sensitivity of micro-ribbon sensors shows no significant change in the range. In particular, the micro-ribbon meanders with three turns are the least sensitive to bending deformation and can be used to develop stable and flexible GMI sensors for wearable electronics devices.

Omics analyses of Rehmannia glutinosa dedifferentiated and cambial meristematic cells reveal mechanisms of catalpol and indole alkaloid biosynthesis.

BACKGROUND: Rehmannia glutinosa is a rich source of terpenoids with a high medicinal reputation. The present study compared dedifferentiated cells (DDCs) and cambial meristematic cells (CMCs) cell cultures of R. glutinosa for terpenoid (catalpol) and indole alkaloid (IA) biosynthesis. In this regard, we used widely targeted metabolomics and transcriptome sequencing approaches together with the comparison of cell morphology, cell death (%), and catalpol production at different time points. RESULTS: We were able to identify CMCs based on their morphology and hypersensitivity to zeocin. CMCs showed higher dry weight content and better catalpol production compared to DDCs. The metabolome analysis revealed higher concentrations of IA, terpenoids, and catalpol in CMCs compared to DDCs. The transcriptome sequencing analysis showed that a total of 27,201 genes enriched in 139 pathways were differentially expressed. The higher catalpol concentration in CMCs is related to the expression changes in genes involved in acetyl-CoA and geranyl-PP biosynthesis, which are precursors for monoterpenoid biosynthesis. Moreover, the expressions of the four primary genes involved in monoterpenoid biosynthesis (NMD, CYP76A26, UGT6, and CYP76F14), along with a squalene monooxygenase, exhibit a strong association with the distinct catalpol biosynthesis. Contrarily, expression changes in AADC, STR, and RBG genes were consistent with the IA biosynthesis. Finally, we discussed the phytohormone signaling and transcription factors in relation to observed changes in metabolome. CONCLUSIONS: Overall, our study provides novel data for improving the catalpol and IA biosynthesis in R. glutinosa.

Excessive Sedentary Time Is Associated with Cognitive Decline in Older Patients with Minor Ischemic Stroke.

BACKGROUND: Cognitive impairment is commonly seen after acute ischemic stroke (AIS). Sedentary behaviors increase the risk of dementia among community dwelling population. OBJECTIVE: This study aims to investigate the association of sedentary behaviors with poststroke cognitive impairment among older adults with minor AIS. METHODS: This cohort study recruited 594 older subjects with minor AIS from three hospitals in China during February 1, 2016, and December 31, 2018. Participants were followed up for two years and the sedentary time per day was self-reported at the end of follow-up. Cognitive functions were assessed by Mini-Mental State Examination (MMSE). Participants were categorized into the high and low sedentary time group according to the median sedentary time of the participants. RESULTS: At two years of follow-up, the long sedentary time group had significantly lower MMSE scores than the short sedentary time group [median, (IQR): 21 (18 to 25) versus 22 (18 to 25), p = 0.368]. The long sedentary time group had a higher speed of cognitive decline than the short sedentary time group. Excessive sedentary time was associated with a higher risk of longitudinal cognitive decline (OR: 2.267, 95% CI: 1.594 to 3.225), adjusting for age, sex, education, body mass index, APOE genotype, comorbidities, symptoms of depression, anxiety, and insomnia, baseline MMSE scores and National Institute of Health Stroke Scale scores, cognitive therapy, and TOAST ischemic stroke subtypes. CONCLUSIONS: This study identified a possible link between sedentary behaviors and longitudinal cognitive decline among older patients with minor AIS, suggesting that reducing sedentary time might be helpful for preventing poststroke dementia.

A lytic phage to control multidrug-resistant avian pathogenic Escherichia coli (APEC) infection.

The inappropriate use of antibiotics has led to the emergence of multidrug-resistant strains. Bacteriophages (phages) have gained renewed attention as promising alternatives or supplements to antibiotics. In this study, a lytic avian pathogenic Escherichia coli (APEC) phage designated as PEC9 was isolated and purified from chicken farm feces samples. The morphology, genomic information, optimal multiplicity of infection (MOI), one-step growth curve, thermal stability, pH stability, in vitro antibacterial ability and biofilm formation inhibition ability of the phage were determined. Subsequently, the therapeutic effects of the phages were investigated in the mice model. The results showed that PEC9 was a member of the siphovirus-like by electron microscopy observation. Biological characterization revealed that it could lyse two serotypes of E. coli, including O1 (9/20) and O2 (6/20). The optimal multiplicity of infection (MOI) of phage PEC9 was 0.1. Phage PEC9 had a latent period of 20 min and a burst period of 40 min, with an average burst size of 68 plaque-forming units (PFUs)/cell. It maintained good lytic activity at pH 3-11 and 4-50°C and could efficiently inhibit the bacterial planktonic cell growth and biofilm formation, and reduce bacterial counts within the biofilm, when the MOI was 0.01, 0.1, and 1, respectively. Whole-genome sequencing showed that PEC9 was a dsDNA virus with a genome of 44379 bp and GC content of 54.39%. The genome contains 56 putative ORFs and no toxin, virulence, or resistance-related genes were detected. Phylogenetic tree analysis showed that PEC9 is closely related to E. coli phages vB_EcoS_Zar3M, vB_EcoS_PTXU06, SECphi18, ZCEC10, and ZCEC11, but most of these phages exhibit different gene arrangement. The phage PEC9 could successfully protect mice against APEC infection, including improved survival rate, reduced bacterial loads, and organ lesions. To conclude, our results suggest that phage PEC9 may be a promising candidate that can be used as an alternative to antibiotics in the control of APEC infection.

Experimental Study on the Influence of Transverse Crack on Chloride Ingress in Concrete Slab Track of High-Speed Railway.

The concrete track slab and the base slab of the high-speed railway CRTS II track structure are prone to transverse cracks in the initial service period, which are subjected to environmental action and train load. In order to investigate the influence of transverse cracks on chloride ingress of concrete track slab and base slab in a coastal environment, drying-wetting cycle chloride erosion tests were carried out on reinforced concrete track slab and base slab specimens with cracks ranging from 0 mm to 0.6 mm, subjected to continuous bending moment. The chloride ion concentration of concrete along the depth direction was collected during the test process. The experimental results show that the chloride ion concentration of concrete at the crack section is much higher than that at the intact section, and it increases with the increase of crack width in the range of 0.2 mm to 0.6 mm. A chloride diffusion coefficient model of cracked concrete is proposed for slab track based on the experimental results, which can comprehensively consider the effects of surface chloride ion concentration, chloride binding effect, time-varying effect, temperature, relative humidity, and transverse crack width.

The reason and mechanism of propylene glycol alginate sodium sulfate (PSS) mediated allergic side effect.

Propylene glycol alginate sodium sulfate (PSS) is a heparinoid polysaccharide drug used in clinic for >30 years in China. But its allergy events happened from time to time and should not be ignored. Here, ammonium salt in PSS (PSS-NH4+), PSS fractions with high Mw (PSS-H-Mw) and low mannuronic acid (M) to guluronic acid (G) ratio (PSS-L-M/G) were found to induce allergic response by the structure-activity and impurity-activity relationships in vitro. Furthermore, we confirmed the reason and elucidated the mechanism accounted for allergic side effect of PSS in vivo. It was found that high IgE levels in PSS-NH4+ and PSS-H-Mw groups upregulate the cascade expression of Lyn-Syk-Akt or Erk and second messenger Ca2+, which accelerated mast cells (MCs) degranulation to release histamine, LTB4, TPS, and finally induced lung tissue injury. PSS-L-M/G caused a mild allergic symptom because it only enhanced the expression of p-Lyn and histamine release. In brief, PSS-NH4+ and PSS-H-Mw were main reasons to result in allergic response. Our results suggested that it is very necessary to control the range of Mw and the content of impurities (< 1 % ammonium salt) of PSS to guarantee its safety and effectiveness in clinical treatment.

Inhibitory Effects of 3-Cyclopropylmethoxy-4-(difluoromethoxy) Benzoic Acid on TGF-ß1-Induced Epithelial-Mesenchymal Transformation of In Vitro and Bleomycin-Induced Pulmonary Fibrosis In Vivo.

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease characterized by lung inflammation and excessive deposition of extracellular matrix components. Transforming growth factor-ß1 (TGF-ß1) induced epithelial-mesenchymal transformation of type 2 lung epithelial cells leads to excessive extracellular matrix deposition, which plays an important role in fibrosis. Our objective was to evaluate the effects of 3-cyclopropylmethoxy-4-(difluoromethoxy) benzoic acid (DGM) on pulmonary fibrosis and aimed to determine whether EMT plays a key role in the pathogenesis of pulmonary fibrosis and whether EMT can be used as a therapeutic target for DGM therapy to reduce IPF. Firstly, stimulation of in vitro cultured A549 cells to construct EMTs with TGF-ß1. DGM treatment inhibited the expression of proteins such as α-SMA, vimentin, and collagen Ⅰ and increased the expression of E-cadherin. Accordingly, Smad2/3 phosphorylation levels were significantly reduced by DGM treatment. Secondly, models of tracheal instillation of bleomycin and DGM were used to treat rats to demonstrate their therapeutic effects, such as improving lung function, reducing lung inflammation and fibrosis, reducing collagen deposition, and reducing the expression of E-cadherin. In conclusion, DGM attenuates TGF-ß1-induced EMT in A549 cells and bleomycin-induced pulmonary fibrosis in rats.

The investigation on the hypercoagulability of hepatocellular carcinoma-related cerebral infarction with thromboelastography.

AIM: To investigate the hypercoagulability of hepatocellular carcinoma (HCC)-related cerebral infarction (HCRCI) with thromboelastography (TEG). METHODS: A multicenter prospective study was conducted in HCRCI patients, HCC patients without cerebral infarction, and acute cerebral infarction (ACI) patients without HCC between January 2016 and December 2019. TEG parameters and laboratory and clinical data were collected and compared among the three groups. To confirm the independent risk factors of HCRCI, multivariate analyses were conducted. Receiver operating characteristic (ROC) curves were utilized to evaluate the area under the curve (AUC) plotted by each independent risk factor. RESULTS: There were 38 patients recruited in the HCRCI group, and 152 patients were recruited to the HCC group and the ACI group. The levels of plasma neutrophil count, D-dimer, α-fetoprotein (AFP), carcinoembryonic antigen, and maximum amplitude (MA)-a parameter of TEG-were significantly higher in the HCRCI group than HCC and ACI groups. Multivariate logistic regression analysis showed that increased neutrophile count, D-dimer, AFP, and MA were independently associated with HCRCI. ROC curve analysis showed first that AUC of MA for HCRCI was .875, which was larger than the other risk factors, and second that the optimal cutoff value for MA was 61.35, with a sensitivity of 89.50% and specificity of 66.40%. CONCLUSION: It was suggested that TEG disclosed that the pathogenesis of HCRIC is exactly related to the hypercoagulability. And with a cutoff value of MA equaling to 61.35, TEG facilitates clinicians to identify HCC patients at high risk of HCRIC.

Leonurine attenuates OVA-induced asthma via p38 MAPK/NF-κB signaling pathway.

Leonurine (Leo) is a natural alkaloid extracted from Herba leonuri, which has many biological activities. However, whether leonurine has a protective effect on asthma remains unknown. The purpose of this study was to investigate the protective effect of leonurine on asthma. We evaluated its therapeutic effect and related signal transduction in LPS-induced RAW264.7 cells and OVA-induced asthmatic mice. In addition, we used network pharmacology, molecular docking and molecular dynamics simulation to verify the experimental results. In LPS-induced RAW 264.7 cells, leonurine significantly reduced the production of TNF-α and IL-6, andinhibited the activation of p38 MAPK/NF-κB signaling pathway. In OVA-induced asthmatic mice, leonurine decreased the number of inflammatory cells in the bronchoalveolar lavage fluid (BALF), particularly neutrophils and eosinophils. Leonurine also reduced the contents of IL-4, IL-5, IL-13 in the BALF and OVA-IgE in the serum. Leonurine remarkly improved OVA-induced inflammatory cell infiltration and significantly inhibited mucus overproduction. In addition, leonurine inhibited the activation of p38 MAPK/NF-κB signaling pathway in the lung tissues of asthmatic mice. Network pharmacology suggested that p38 MAPKα was a potential target of leonurine in the treatment of asthma. Molecular docking and molecular dynamics simulations indicated that leonurine could stably bind to p38 MAPKα protein. In summary, leonurine attenuated asthma by regulating p38 MAPK/NF-κB signaling pathway.

Development and validation of four ferroptosis-related gene signatures and their correlations with immune implication in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. This tumor presents with an insidious onset, rapid progression, and frequent recurrence. Ferroptosis is a newly discovered mode of programmed cell death that may play a key role in the progression of HCC. This study aimed to investigate the prognostic value of ferroptosis-related genes (FRGs) in HCC and their impact on tumor immune function, thereby providing new insights into targeted therapy for HCC. First, 43 differentially expressed FRGs were identified using the TCGA database, and four prognostically relevant methylation-driven FRGs (G6PD, HELLS, RRM2, and STMN1) were screened via survival and methylation analyses. Gene co-expression, mutation, and clinicopathological characterization indicated that these four pivotal FRGs play essential roles in tumor progression. We also validated these four genes using transcriptomic and proteomic data as well as cohort samples from our patients. Moreover, receiver operator characteristic (ROC) curves confirmed that the signatures of the four FRGs were independent prognostic factors in HCC. Gene set enrichment analysis of the four FRGs showed statistically significant associations with pathways related to HCC proliferation. Finally, the TIMER and TISIDB databases indicated that the four FRGs were statistically significantly correlated with tumor-infiltrating immune cells and immune checkpoint expression. Taken together, this study provides information guiding a novel therapeutic strategy targeting FRGs for HCC treatment.

Plasma Calprotectin Is Predictive for Short-Term Functional Outcomes of Acute Ischemic Stroke.

Background: Blood-based prognostic biomarkers of acute ischemic stroke (AIS) are limiting. Calprotectin is suggested to be involved in directing post-stroke inflammatory conditions. However, the pathological alteration of circulating calprotectin in AIS is yet to be thoroughly elucidated. Therefore, this study aimed to investigate the levels and clinical relevance of calprotectin in AIS. Methods: This study recruited 271 patients with AIS within 24 h since symptom onset and 145 non-stroke healthy controls (HC) from February 1, 2018, to Dec 31, 2020. Patients were followed up for 2 weeks for observation of functional outcomes, as determined by the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS). Plasma calprotectin concentrations were determined by ELISA. Results: Plasma calprotectin concentrations were significantly higher in patients with AIS compared with controls [patients vs. control: median (IQR) 54.2 (39.01-99.04) vs. 50.04 (35.42-61.22), p < 0.001]. Besides, patients with poor prognosis, as defined by mRS ≥ 3, had significantly higher calprotectin levels than patients with good prognosis [poor prognosis patients vs. good prognosis patients: median (IQR) 61.99 (47.52-108) vs. 43.36 (33.39-60.2), p < 0.001]. Plasma calprotectin levels were positively associated with the disease severity of AIS, as reflected by infarction volume and NIHSS score at baseline. Furthermore, baseline calprotectin was found to be independently associated with poor prognosis [odds ratio (OR): 1.02, 95% CI: 1.01-1.03] and disease progression (OR: 1.03, 95% CI: 1.02-1.04) of AIS during a 2-week follow-up, with adjustment of possible confounding factors. Conclusion: Plasma calprotectin is associated with short-term functional outcomes of AIS.

Stimulating the Hematopoietic Effect of Simulated Digestive Product of Fucoidan from Sargassum fusiforme on Cyclophosphamide-Induced Hematopoietic Damage in Mice and Its Protective Mechanisms Based on Serum Lipidomics.

Hematopoietic damage is a serious side effect of cytotoxic drugs, and agents promoting hematopoiesis are quite important for decreasing the death rate in cancer patients. In our previous work, we prepared the simulated digestive product of fucoidan from Sargassum fusiforme, DSFF, and found that DSFF could activate macrophages. However, more investigations are needed to further evaluate whether DSFF could promote hematopoiesis in the chemotherapy process. In this study, the protective effect of DSFF (1.8-7.2 mg/kg, i.p.) on cyclophosphamide-induced hematopoietic damage in mice and the underlying mechanisms were investigated. Our results show that DSFF could restore the numbers of white blood cells, neutrophils, and platelets in the peripheral blood, and could also retard bone marrow cell decrease in mice with cyclophosphamide-induced hematopoietic damage. UPLC/Q-Extraction Orbitrap/MS/MS-based lipidomics results reveal 16 potential lipid biomarkers in a serum that responded to hematopoietic damage in mice. Among them, PC (20:1/14:0) and SM (18:0/22:0) were the key lipid molecules through which DSFF exerted protective actions. In a validation experiment, DSFF (6.25-100 µg/mL) could also promote K562 cell proliferation and differentiation in vitro. The current findings indicated that DSFF could affect the blood cells and bone marrow cells in vivo and thus showed good potential and application value in alleviating the hematopoietic damage caused by cyclophosphamide.

The Index of Esophageal Cancer Related Ischemic Stroke: A Retrospective Patient Control Study.

Purpose: To investigate independent risk factors for esophageal cancer-related ischemic stroke (ECIS) and to use them to develop an index of ECIS to help clinicians identify patients at high risk for ECIS or to identify ECIS from other types of ischemic stroke. Methods: We retrospectively enrolled active esophageal cancer (EC) patients with acute ischemic stroke (ECIS group) and patients with active EC without ischemic stroke (EC group), age- and sex-matched with ECIS patients, at seven centers from January 2011 to December 2020. Clinical data and laboratory and imaging findings were collected. Univariate and multivariate analyses were performed to analyze the independent risk factors for ECIS. Optimal cutoffs for sensitivities and specificities were obtained by Youden's J statistic following a receiver operator characteristic (ROC) analysis of each risk factor and the product of the risk factors. Results: A total of 91 ECIS patients and 91 EC patients were included. Elevated levels of carcinoembryonic antigen (CEA) [odds ratio (OR) = 0.105, 95% confidence interval (CI): 1.051-1.174, P < 0.001], D-dimer (DD) (OR = 0.003, 95% CI: 1.002-1.004, P < 0.001), and neutrophil count (OR = 0.857, 95% CI: 1.628-3.407, P < 0.001) were independent risk factors for ECIS. The area under the curve (AUC) of each independent risk factor and the product of the three independent risk factors were calculated by a receiver operator characteristic (ROC) curve, and the cutoff value from the largest AUC was called the ECIS index. Conclusion: It was suggested that elevated plasma DD and CEA levels and increased neutrophils in EC patients may altogether contribute to the development of ECIS. The index of ECIS may facilitate clinicians to identify patients at high risk for ECIS or to identify ECIS from other etiologic types of ischemic stroke.

Eupatilin Suppresses OVA-Induced Asthma by Inhibiting NF-κB and MAPK and Activating Nrf2 Signaling Pathways in Mice.

To investigate the effect of eupatilin in asthma treatment, we evaluated its therapeutic effect and related signal transduction in OVA-induced asthmatic mice and LPS-stimulated RAW264.7 cells. The BALF was tested for changes in lung inflammatory cells. Th2 cytokines in the BALF and OVA-IgE in the serum were measured by ELISA. H&E and PAS staining were used to evaluate histopathological changes in mouse lungs. The key proteins NF-κB, MAPK, and Nrf2 in lung tissues were quantitatively analyzed by Western blotting. Finally, we evaluated the effect of eupatilin on cytokines and related protein expression in LPS-stimulated RAW 264.7 cells in vitro. In OVA-induced asthmatic mice, eupatilin reduced the numbers of inflammatory cells, especially neutrophils and eosinophils. Eupatilin also decreased the levels of IL-5, IL-13 in the BALF and OVA-IgE in the serum. Furthermore, eupatilin inhibited the activation of NF-κB and MAPK pathways and increased the expression of Nrf2 in OVA-induced asthmatic mice. In vitro, eupatilin significantly reduced LPS-stimulated NO, IL-6, and ROS production. Additionally, the NF-κB, MAPK, and Nrf2 protein expression in LPS-stimulated RAW264.7 cells was consistent with that in OVA-induced asthmatic lung tissues. In summary, eupatilin attenuated OVA-induced asthma by regulating NF-κB, MAPK, and Nrf2 signaling pathways. These results suggest the utility of eupatilin as an anti-inflammatory drug for asthma treatment.

Clostridium butyricum Alleviates Enterotoxigenic Escherichia coli K88-Induced Oxidative Damage Through Regulating the p62-Keap1-Nrf2 Signaling Pathway and Remodeling the Cecal Microbial Community.

Clostridium butyricum (CB) can enhance antioxidant capacity and alleviate oxidative damage, but the molecular mechanism by which this occurs remains unclear. This study used enterotoxigenic Escherichia coli (ETEC) K88 as a pathogenic model, and the p62-Keap1-Nrf2 signaling pathway and intestinal microbiota as the starting point to explore the mechanism through which CB alleviates oxidative damage. After pretreatment with CB for 15 d, mice were challenged with ETEC K88 for 24 h. The results suggest that CB pretreatment can dramatically reduce crypt depth (CD) and significantly increase villus height (VH) and VH/CD in the jejunum of ETEC K88-infected mice and relieve morphological lesions of the liver and jejunum. Additionally, compared with ETEC-infected group, pretreatment with 4.4×106 CFU/mL CB can significantly reduce malondialdehyde (MDA) level and dramatically increase superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels in the serum. This pretreatment can also greatly increase the mRNA expression levels of tight junction proteins and genes related to the p62-Keap1-Nrf2 signaling pathway in the liver and jejunum in ETEC K88-infected mice. Meanwhile, 16S rDNA amplicon sequencing revealed that Clostridium disporicum was significantly enriched after ETEC K88 challenge relative to the control group, while Lactobacillus was significantly enriched after 4.4×106 CFU/mL CB treatment. Furthermore, 4.4×106 CFU/mL CB pretreatment increased the short-chain fatty acid (SCFA) contents in the cecum of ETEC K88-infected mice. Moreover, we found that Lachnoclostridium, Roseburia, Lactobacillus, Terrisporobacter, Akkermansia, and Bacteroides are closely related to SCFA contents and oxidative indicators. Taken together, 4.4×106 CFU/mL CB pretreatment can alleviate ETEC K88-induced oxidative damage through activating the p62-Keap1-Nrf2 signaling pathway and remodeling the cecal microbiota community in mice.

Clostridium butyricum Protects IPEC-J2 Cells from ETEC K88-Induced Oxidative Damage by Activating the Nrf2/ARE Signaling Pathway.

Clostridium butyricum (CB) is a naturally occurring probiotic compound that can alleviate the oxidative damage induced by enterotoxigenic Escherichia coli K88 (ETEC K88) in porcine intestinal epithelial (IPEC-J2) cells. In this study, we investigate the molecular mechanism underlying this effect. Based on cell viability, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPX) assessments, the optimal concentration of ETEC K88 was determined to be 1 × 103 cfu/mL. Viable bacteria counts in cells pretreated with CB and then infected with ETEC K88 show that CB can adhere to IPEC-J2 cells and that optimal adhesion is achieved at the multiple infection index (MOI) of 50 at 3 h of pretreatment. The results of qPCR indicate that although ETEC significantly decreases the expression levels of antioxidant enzymes regulated by NF-E2-related factor 2 (Nrf2) compared to the control group, CB reverses this effect. To confirm that Nrf2 is directly involved in the mechanism by which CB alleviates oxidative stress, siRNA was used to silence the expression of Nrf2 gene in IPEC-J2 cells. Compared to the NC+ETEC and siRNA+ETEC groups, the expressions of SOD1, SOD2, GPX1, and GPX2 in the NC+CB+ETEC and siRNA+CB+ETEC groups are significantly increased at 12 h and 24 h. This shows that CB can reduce ETEC K88-induced oxidative damage in IPEC-J2 cells by activating the expression of antioxidant enzymes implicated in the Kelch-like ECH-associated protein-1- (Keap1-) Nrf2/antioxidant response element (ARE) signaling pathway.

Effects of simulated digestion in vitro on the structure and macrophages activation of fucoidan from Sargassum fusiforme.

Molecular size and spatial structure affect the bioactivities of polysaccharides. SFF is a fucoidan extracted from Sargassum fusiforme. The possible changes of SFF affected by gastrointestinal tract and subsequently changes of its physicochemical property or its bioactivity have yet to be systematically investigated. Our results showed that DSFF, the gastrointestinal digestion product of SFF, has increased reducing sugar content, increased proportion of low molecular weight components, and a more clustered island-like morphology. Both SFF and DSFF activate RAW 264.7 macrophages evidenced by the increasing level of NO, intracellular ROS, and macrophages cytokines. Further investigation showed that DSFF induced M1 phenotype polarization in RAW 264.7 cells. DSFF also showed stronger macrophage activation and phenotype polarization than SFF. Our present work showed that SFF could be digested by simulated gastrointestinal environment in vitro and the digested product DSFF showed higher efficiency in macrophages activation and phenotype polarization.

Clostridium butyricum Helps to Alleviate Inflammation in Weaned Piglets Challenged With Enterotoxigenic Escherichia coli K88.

Background: Whether the probiotic Clostridium butyricum (CB) alleviates enterotoxigenic Escherichia coli (ETEC) K88-induced inflammation by regulating the activation of the toll-like receptor (TLR) signaling pathway is not clear, thus, we carried out this study. A total of 72 piglets (average body weight 7.09 ± 0.2 kg) were randomly divided into three groups of 24 piglets per group. Pigs were either fed a daily diet (NC, negative control), a diet tested every day by 1 × 109 CFU/mL ETEC K88 (PC, positive control), or a basal diet supplemented with 5 × 105 CFU/g CB and challenged with ETEC K88 (PC + CB group). Results: Our results showed that CB pretreatment attenuated the effect of ETEC K88 by decreasing C-reactive protein (CRP), which resulted in tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) production. Histological examination revealed that CB pretreatment alleviated intestinal villi injury caused by ETEC K88 challenge. Furthermore, CB pretreatment promoted mRNA expression of the negative regulators of TLR signaling, including myeloid differentiation factor (MyD88), toll-interacting protein (Tollip), and B cell CLL/lymphoma 3 (Bcl-3), in the intestines of ETEC K88-challenged piglets. ETEC K88-induced activation of nuclear factor kappa B (NF-κB) and nuclear factor of kappa light polypeptide gene enhancer in B cells inhibitor alpha (IκBα) was attenuated by CB pretreatment. Conclusion: These findings indicate that CB helps to maintain and strengthen the shape of intestinal villi and limits detrimental inflammatory responses, partly by inhibiting toll-like receptor 2 (TLR-2), toll-like receptor 4 (TLR-4), and toll-like receptor 5 (TLR-5) expression and inhibiting NF-κB p65, and promoting IκBα activation and synergism among its negative regulators.