A deuterohemin peptide protects cerebral ischemia-reperfusion injury by preventing oxidative stress in vitro and in vivo.

Cerebral ischemia-reperfusion injury (CIRI) is a brain injury that usually occurs during thrombolytic therapy for acute ischemic stroke and impacts human health. Oxidative stress is one of the major causative factors of CIRI. DhHP-3 is a novel peroxidase-mimicking enzyme that exhibits robust reactive oxygen species (ROS) scavenging ability in vitro. Here, we established in vitro and in vivo models of cerebral ischemia-reperfusion to mechanistically investigate whether DhHP-3 can alleviate CIRI. DhHP-3 could reduce ROS, down-regulate apoptotic proteins, suppress p53 phosphorylation, attenuate the DNA damage response (DDR), and inhibit apoptosis in SH-SY5Y cells subjected to oxygen-glucose deprivation/re-oxygenation (OGD/R) and in the brain of Sprague Dawley rats subjected to transient middle cerebral artery occlusion. In conclusion, DhHP-3 has bioactivity of CIRI inhibition through suppression of the ROS-induced apoptosis.

Van der Waals heterostructure gas sensors based on narrow-wide bandgap semiconductors for superior sensitivity.

Achieving high sensitivity in gas sensors is crucial for the precise detection of toxic agents. However, this can be challenging as it requires gas sensors to possess both a high response signal and low electrical noise simultaneously, which seems controversial as it necessitates adopting semiconductors with different bandgaps. Herein, we demonstrate the superior sensitivity of 2D molybdenum disulfide (MoS2)/tellurium (Te) van der Waals heterostructure (vdWH) gas sensors fabricated by combining narrow-bandgap (Te) and wide-bandgap (MoS2) semiconductors. The as-fabricated MoS2/Te vdWH gas sensors exhibit excellent sensitivity that is unavailable for sensors based on its individual counterparts. The response toward 50 ppm NH3is improved by two and six times compared to the individual MoS2and Te gas sensors, respectively. In addition, a high signal-to-noise ratio of ∼350 and an ultralow limit of detection of ∼2 ppb are achieved. These results outperform most previously reported gas sensors due to the efficient modulation of the barrier height of the MoS2/Te p-n junction as well as the synergistic effect benefiting from the low electric noise of the narrow-bandgap Te and high response signal of the wide-bandgap MoS2. Our work provides an insight into utilizing vdWHs based on narrow-wide bandgap semiconductors for developing highly sensitive gas sensors.

Transposon-aided capture (TRACA) of plasmids from the human gut.

The gut microbiota consists of a vast and diverse assemblage of microorganisms that play a pivotal role in maintaining host health. Nevertheless, a significant portion of the human gut microbiota remains uncultivated. Plasmids, a type of MGE, assume a critical function in the biological evolution and adaptation of bacteria to varying environments. To investigate the plasmids present within the gut microbiota community, we used the transposon-aided capture method (TRACA) to explore plasmids derived from the gut microbiota. In this study, fecal samples were collected from two healthy human volunteers and subsequently subjected to the TRACA method for plasmid isolation. Then, the complete sequence of the plasmids was obtained using the genome walking method, and sequence identity was also analyzed. A total of 15 plasmids were isolated. At last, 13 plasmids were successfully sequenced, of which 12 plasmids were highly identical to the plasmids in the National Center for Biotechnology Information (NCBI) database and were all small plasmids. Furthermore, a putative novel plasmid, named pMRPHD, was isolated, which had mobilized elements (oriT and oriV) and a potential type II restriction-modification (R-M) system encoded by DNA cytosine methyltransferase and type II restriction enzyme (Ban I), whose specific functions and applications warrant further exploration.

Selenium nanoparticles: Enhanced nutrition and beyond.

Selenium is a trace nutrient that has both nutritional and nutraceutical functions, whereas narrow nutritional range of selenium intake limits its use. Selenium nanoparticles (SeNPs) are less toxic and more bioavailable than traditional forms of selenium, suggesting that SeNPs have the potential to replace traditional selenium in food industries and/or biomedical fields. From the perspective of how SeNPs can be applied in health area, this review comprehensively discusses SeNPs in terms of its preparation, nutritional aspect, detoxification effect of heavy metals, nutraceutical functions and anti-pathogenic microorganism effects. By physical, chemical, or biological methods, inorganic selenium can be transformed into SeNPs which have increased stability and bioavailability as well as low toxicity. SeNPs are more effective than traditional selenium form in synthesizing selenoproteins like glutathione peroxidases. SeNPs can reshape the digestive system to facilitate digestion and absorption of nutrients. SeNPs have shown excellent potential to adjunctively treat cancer patients, enhance immune system, control diabetes, and prevent rheumatoid arthritis. Additionally, SeNPs have good microbial anti-pathogenic effects and can be used with other antimicrobial agents to fight against pathogenic bacteria, fungi, or viruses. Development of novel SeNPs with enhanced functions can greatly benefit the food-, nutraceutical-, and biomedical industries.

Gynostemma pentaphyllum and Gypenoside-IV Ameliorate Metabolic Disorder and Gut Microbiota in Diet-Induced-Obese Mice.

Gynostemma pentaphyllum (G. pentaphyllum) is a perennial liana herb of the Cucurbitaceae family which has both nutraceutical and pharmacological functions. The objective of the current study was to investigate the preventative effects of G. pentaphyllum and Gypenoside-IV (GP-IV, a saponin monomer in G. pentaphyllum) on metabolic symptoms in high fat diet induced obese (DIO) mice with gut microbiota dysbiosis. G. pentaphyllum water extract (GPWE, 150 mg/kg•d- 1) and GP-IV (50 mg/kg•d- 1) were orally administered to DIO mice by gavage for 10 weeks. The results showed that both GPWE and GP-IV prevented obesity development by decreasing body weight gain, reducing fat mass/body weight ratio and inhibiting adipocyte hypertrophy. GPWE and GP-IV also improved lipid profile and glucose tolerance effectively. Moreover, GPWE and GP-IV treatments partly restored gut microbiota in DIO mice. Typically, GPWE and GP-IV reduced Firmicutes to Bacteroidetes ratio, increased the abundance of certain health-promoting bacteria and reduced the abundance of microbiota that were associated with metabolic disorders. We conclude that GPWE and GP-IV can ameliorate metabolic symptoms possibly via modulating gut microbiota in DIO mice.

Chlorogenic acid ameliorates obesity by preventing energy balance shift in high-fat diet induced obese mice.

BACKGROUND: Chlorogenic acid is a type of phenolic acid found in many plants. Chlorogenic acid has an anti-obesity effect with an unclear mechanism. The present study aimed to investigate the regulatory effect of chlorogenic acid on energy balance in high-fat diet (HFD) induced obese C57BL/6J mice administrated 100 mg kg-1 chlorogenic acid for 13 weeks. RESULTS: The consumption of chlorogenic acid ameliorated HFD induced obesity. Chlorogenic acid did not change the physical activity but significantly decreased food intake and increased body temperature, thermal dissipation and brown adipose tissue activity. Moreover, chlorogenic acid improved glucose tolerance but had a moderate impact on other blood indices. Additionally, chlorogenic acid failed to restore the microbiota change associated with HFD induced obesity, but modified the gut bacterial composition in a unique way. CONCLUSION: Supplementation with chlorogenic acid can improve HFD induced obesity and associated glucose intolerance mainly via regulating food intake and energy expenditure. © 2020 Society of Chemical Industry.

Literature-Based Phenotype Survey and In Silico Genotype Investigation of Antibiotic Resistance in the Genus Bifidobacterium.

Bifidobacteria are typical commensals inhabiting the human intestine and are beneficial to the host because of their probiotic properties. One of the risks concerning probiotics is the potential of introducing antibiotic resistance genes (ARGs) to the host gut pathogens. This study was aimed to depict the general antibiotic resistance characteristics of the genus Bifidobacterium by combining the reported phenotype dataset and in silico genotype prediction. Bifidobacteria were mostly reported to be sensitive to beta-lactams, glycopeptides, chloramphenicol, and rifampicin, but resistant to aminoglycosides, polypeptides, quinolones, and mupirocin. Generally, the resistance phenotypes to erythromycin, tetracycline, fusidic acid, metronidazole, clindamycin, and trimethoprim were variable. Besides cmX and tetQ, characterized in bifidobacterial resident plasmids, 3520 putative ARGs were identified from 831 bifidobacterial genomes through BLASTP search. The identified ARGs matched thirty-eight reference ARGs, four of which seemed to be mutant housekeeping genes. The two high-abundant ARGs, tetW and ermX, were found to have different distribution traits. The predicted ARGs reasonably explained most of the corresponding resistant phenotypes in the published literature.

The Prebiotic Activity of Simulated Gastric and Intestinal Digesta of Polysaccharides from the Hericium erinaceus.

Hericium erinaceus (HE) is a well-known edible and medicinal fungus widely grown in Asian countries. Polysaccharides from the Hericium erinaceus (HEP) are major biological macromolecules. It has been reported that HEP has multiple biological activities, such as antioxidant activity, immunomodulatory effects, anti-inflammatory effect, anti-chronic gastritis activity, and so on. In the current study, we investigated the biological property of HEP during gastrointestinal digestion. The results indicated that both simulated gastric and small intestinal digesta of HEP has better stimulation of probiotics growth than HEP alone, especially for Lactobacillus plantarum BG112. The prebiotic activity was the strongest when HEP was treated by simulated gastric juice for 2 h and by simulated small intestinal juice for 4 h. The molecular weight (Mw) of HEP decreased from 1.68 × 106 Da and 2.32 × 104 Da to 529.3 ± 7.2 Da, as digestion time increased. Meanwhile, the reducing sugar content was significantly increased from 0.610 ± 0.007 to 22.698 ± 0.752 mg/ml, suggesting that the decrease of Mw was likely due to the breakdown of glycosidic bonds. Considerable mannose and galactopyranose were released throughout the gastrointestinal digestion period, indicating that the gastrointestinal digestion resulted in production of free monosaccharides. After fermentation of L. plantarum BG112, the Mw of HEP was decreased and short chain fatty acids (SCFAs) including acetic acid, isovaleric acid, lactic acid, and butyric acid were produced. We speculated that the release of free monosaccharides during gastrointestinal digestion and utilization of HEP, by the probiotics, contributed to the prebiotic activity of HEP's gastric and intestinal digesta. These results unveiled some mechanisms on the close relationship between the structure and bioactivity of polysaccharides, during digestion.

Lipid Rafts Disruption Increases Ochratoxin A Cytotoxicity to Hepatocytes.

Lipid rafts are microdomains in plasma membrane and can mediate cytotoxicity. In this study, the role of lipid rafts in ochratoxin A-induced toxicity was investigated using Hepatoblastoma Cell Line HepG-2 cells. Disruption of cholesterol-containing lipid rafts enhanced Ochratoxin A (OTA) toxicity, as shown by increased lactate dehydrogenase leakage, increased reactive oxygen species level and reduction of superoxide dismutase activity in a time-dependent manner. Isobaric tags for relative and absolute quantitation-based proteomics of the cell membranes showed that nearly 85.5% proteins were downregulated by OTA, indicating that OTA inhibited the membrane protein synthesis. Most of altered proteins were involved in Gene Ontology "transport", "cell adhesion" and "vesicle-mediated transport". In conclusion, lipid rafts play a key role in OTA-induced cytotoxicity. This study provides insight into how OTA toxicity is regulated by the plasma membrane, especially the lipid rafts.

A subchronic feeding study of dicamba-tolerant soybean with the dmo gene in Sprague-Dawley rats.

The dicamba-tolerant soybean MON87708 expresses the dicamba mono-oxygenase (DMO) enzyme that is encoded by the dmo gene. In order to evaluate the safety of this soybean, a 90-day subchronic feeding toxicity study (13 weeks) was conducted on Sprague-Dawley rats. A total of 140 rats were divided into 7 groups (10/sex/group), including a standard commercial diet control group. The genetically modified (GM) soybean MON87708 and the near isogenic non-GM soybean A3525 were respectively processed to unhulled, full-fat, and heat-treated powder, then mixed into the diet at levels of 7.5%, 15%, and 30% (wt/wt) with the main nutrients of the various diets balanced and then fed to 6 groups. The remaining group of rats fed with a commercial rat diet served as blank control. Some isolated parameters indicated statistically significant differences in body weight, feed consumption/utilization, hematology, serum biochemistry, and relative organ weights. These differences were not consistent across gender or test-diet dose, which were attributed to incidental and biological variability. In conclusion, the results demonstrated that the transgenic soybean MON87708 containing DMO was as safe as non-transgenic isogenic counterpart with historical safe use.

Pseudoalteromonas xiamenensis sp. nov., a marine bacterium isolated from coastal surface seawater.

A Gram-negative, oxidase- and catalase-positive, rod-shaped, non-spore-forming, motile, aerobic bacterium, designated Y2(T), was isolated from surface seawater of Yundang Lake, Xiamen, China. The strain was able to grow in the presence of 0.5-6.0% NaCl (optimum 1.0-1.5%), at pH 5-10 (optimum pH 8) and at 10-40 °C (optimum 25 °C). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Y2(T) belongs to the genus Pseudoalteromonas, with the highest sequence similarity of 94.9% to Pseudoalteromonas tunicata D2(T); within the genus Pseudoalteromonas, it showed the lowest similarity of 92.8% to Pseudoalteromonas denitrificans ATCC 43337(T). The G+C content of the chromosomal DNA of strain Y2(T) was 45.1 mol%. The predominant fatty acids were summed feature 3 (C(16 : 1)ω6c and/or C(16 : 1)ω7c), C(16 : 0), C(12 : 0) 3-OH and summed feature 8 (C(18 : 1)ω6c and/or C(18 : 1)ω7c). The only respiratory quinone detected was Q-8. Based on the phylogenetic and phenotypic characteristics, strain Y2(T) represents a novel species of the genus Pseudoalteromonas, for which the name Pseudoalteromonas xiamenensis sp. nov. is proposed; the type strain is Y2(T) ( = CGMCC 1.12157(T) = JCM 18779(T)).

Synthesis of porous Co3O4 nanonetworks to detect toluene at low concentration.

Porous Co3O4 nanonetworks (NNWs), converted from precursor CoOOH nanosheets, have been synthesized via a controllable chemical reaction route followed by calcination at 400 °C in air. The morphologies and microstructures of the precursor nanosheets and the final products were characterized by high-resolution transmission electron microscopy and X-ray diffraction, respectively. The growth mechanism of CoOOH nanosheets and the structural transformation processes of NNWs were investigated in detail. Significantly, the porous Co3O4 NNW based sensor showed an enhanced response to toluene gas at low concentration, which was mainly due to its porous neck-connected networks.

Milk: A Natural Guardian for the Gut Barrier.

The gut barrier plays an important role in health maintenance by preventing the invasion of dietary pathogens and toxins. Disruption of the gut barrier can cause severe intestinal inflammation. As a natural source, milk is enriched with many active constituents that contribute to numerous beneficial functions, including immune regulation. These components collectively serve as a shield for the gut barrier, protecting against various threats such as biological, chemical, mechanical, and immunological threats. This comprehensive review delves into the active ingredients in milk, encompassing casein, α-lactalbumin, ß-lactoglobulin, lactoferrin, the milk fat globular membrane, lactose, transforming growth factor, and glycopeptides. The primary focus is to elucidate their impact on the integrity and function of the gut barrier. Furthermore, the implications of different processing methods of dairy products on the gut barrier protection are discussed. In conclusion, this study aimed to underscore the vital role of milk and dairy products in sustaining gut barrier health, potentially contributing to broader perspectives in nutritional sciences and public health.

Target volumes comparison between postoperative simulation magnetic resonance imaging and preoperative diagnostic magnetic resonance imaging for prone breast radiotherapy after breast-conserving surgery.

BACKGROUND: This study investigated the differences in target volumes between preoperative magnetic resonance imaging (MRIpre) and postoperative MRI (MRIpost) for breast radiotherapy after breast-conserving surgery (BCS) using deformable image registration (DIR). METHODS AND MATERIALS: Seventeen eligible patients who underwent whole-breast irradiation in the prone position after BCS were enrolled. On MRIpre, the gross tumor volume (GTV) was delineated as GTVpre, which was then expanded by 10 mm to represent the preoperative lumpectomy cavity (LC), denoted as LCpre. The LC was expanded to the clinical target volume (CTV) and planning target volume (PTV) on the MRIpre and MRIpost, denoted as CTVpre, CTVpost, PTVpre, and PTVpost, respectively. The MIM software system was used to register the MRIpre and MRIpost using DIR. Differences were evaluated regarding target volume, distance between the centers of mass (dCOM), conformity index (CI), and degree of inclusion (DI). The relationship between CILC /CIPTV and the clinical factors was also assessed. RESULTS: Significant differences were observed in LC and PTV volumes between MRIpre and MRIpost (p < 0.0001). LCpre was 0.85 cm3 larger than LCpost, while PTVpre was 29.38 cm3 smaller than PTVpost. The dCOM between LCpre and LCpost was 1.371 cm, while that between PTVpre and PTVpost reduced to 1.348 cm. There were statistically significant increases in CI and DI for LCpost-LCpre and PTVpost-PTVpre (CI = 0.221, 0.470; DI = 0.472, 0.635). No obvious linear correlations (p > 0.05) were found between CI and GTV, primary tumor volume-to-breast volume ratio, distance from the primary tumor to the nipple and chest wall, and body mass index. CONCLUSIONS: Despite using DIR technology, the spatial correspondence of target volumes between MRIpre and MRIpost was suboptimal. Therefore, relying solely on preoperative diagnostic MRI with DIR for postoperative LC delineation is not recommended.

[Application and practice of multidimensional teaching method in "Cell Engineering"].

In order to improve the teaching quality of engineering courses, we introduced a multi-dimensional teaching method into the teaching reform of biology majors in colleges based on the portfolio assessment in the curriculum of Cell Engineering. We reformed the knowledge system, teaching form and implementation scheme of this course. By combining the reform of online teaching, interactive teaching, case teaching and other teaching modes, the students mastered the relevant professional knowledge and the scientific and technological frontier of Cell Engineering. Moreover, their learning interest and enthusiasm, ability of analyzing and solving professional problems related to Cell Engineering also improved. The implementation of teaching reform of this course provides a reference for other similar professional courses in colleges.

Safety evaluation of Balanced Health Care Dan-A medicinal formulation containing traditional edible ingredients in lung tumor-loaded mice.

Chinese formulation-based medicinal food has been widely used in clinical trials, but its safety is not well studied. In this research, the edible safety assessment of Balanced Health Care Dan-a formulation containing traditional edible ingredients that were initially formulated to reduce side effects for lung cancer patients-was studied in mice based on biochemical and gut microbial analyses. The experimental mice were subcutaneously loaded with lung tumor A549 cells and then administrated with Balanced Health Care Dan (200 mg/kg or 400 mg/kg b.w. in gavage feeding) for 4 weeks. The body weight, blood parameters, and pathogenic phenotype in tissues were examined. No toxicological symptom was found in experimental mice compared with the normal control. Comprehensive analyses were also conducted to evaluate intestinal microbiota that are associated with many diseases. Balanced Health Care Dan modified the gut microbiota structure in a positive way. In conclusion, the Chinese formulation-based medicinal food has shown no toxicological effect in mice within 4 weeks of feeding experiment and has the potential to be used in clinical trials.

Characterization and the cholesterol-lowering effect of dietary fiber from fermented black rice (Oryza sativa L.).

Black rice was fermented with Neurospora crassa, after which the dietary fiber (DF) extracted from it was characterized and evaluated for its cholesterol-lowering effect in mice. The findings demonstrated that fermentation increased the level of soluble DF from 17.27% ± 0.12 to 29.69% ± 0.26 and increased the adsorption capacity of DF for water, oil, cholesterol, glucose and sodium cholate. The fermented DF had a more loose and porous structure than that extracted from unfermented rice. Additionally, feeding with DF from the fermented black rice significantly reduced body weight, lowered total cholesterol levels and improved the lipid profile in mice gavaged with a high dose (5 g per kg bw) or a low dose (2.5 g per kg·bw). ELISA showed that the hepatic expression of typical proteins and enzymes that are involved in cholesterol metabolism was regulated by the fermented rice DF, leading to reduced cholesterol production and increased cholesterol clearance. The fermented DF also modified the gut microbiota composition (e.g. Firmicutes reduced and Akkermansia increased), which promoted the production of short-chain fatty acids. In conclusion, fermentation can modify the structure and function of DF in black rice and the fermented dietary fiber has excellent cholesterol lowering effects possibly by cholesterol adsorption, cholesterol metabolism modulation, and intestinal microflora regulation.

Insights into the Mechanisms of Reuterin against Staphylococcus aureus Based on Membrane Damage and Untargeted Metabolomics.

Reuterin is a dynamic small-molecule complex produced through glycerol fermentation by Limosilactobacillus reuteri and has potential as a food biopreservative. Despite its broad-spectrum antimicrobial activity, the underlying mechanism of action of reuterin is still elusive. The present paper aimed to explore the antibacterial mechanism of reuterin and its effects on membrane damage and the intracellular metabolome of S. aureus. Our results showed that reuterin has a minimum inhibitory concentration of 18.25 mM against S. aureus, based on the 3-hydroxypropionaldehyde level. Key indicators such as extracellular electrical conductivity, membrane potential and permeability were significantly increased, while intracellular pH, ATP and DNA were markedly decreased, implying that reuterin causes a disruption to the structure of the cell membrane. The morphological damage to the cells was confirmed by scanning electron microscopy. Subsequent metabolomic analysis identified significant alterations in metabolites primarily involved in lipid, amino acid, carbohydrate metabolism and phosphotransferase system, which is crucial for cell membrane regulation and energy supply. Consequently, these findings indicated that the antibacterial mechanism of reuterin initially targets lipid and amino acid metabolism, leading to cell membrane damage, which subsequently results in energy metabolism disorder and, ultimately, cell death. This paper offers innovative perspectives on the antibacterial mechanism of reuterin, contributing to its potential application as a food preservative.

Apomictic Malus plants exhibit abnormal pollen development.

Apomixis is the asexual reproduction through seeds that leads to the production of genetically uniform progeny. It has become an important tool in plant breeding because it facilitates the retention of genotypes with desirable traits and allows seeds to be obtained directly from mother plants. Apomixis is rare in most economically important crops, but it occurs in some Malus species. Here, the apomictic characteristics of Malus were examined using four apomictic and two sexually reproducing Malus plants. Results from transcriptome analysis showed that plant hormone signal transduction was the main factor affecting apomictic reproductive development. Four of the apomictic Malus plants examined were triploid, and pollen was either absent or present in very low densities in the stamen. Variation in the presence of pollen was associated with variation in the apomictic percentage; specifically, pollen was absent in the stamens of tea crabapple plants with the highest apomictic percentage. Furthermore, pollen mother cells failed to progress normally into meiosis and pollen mitosis, a trait mostly observed in apomictic Malus plants. The expression levels of meiosis-related genes were upregulated in apomictic plants. Our findings indicate that our simple method of detecting pollen abortion could be used to identify apple plants that are capable of apomictic reproduction.

Histidine modulates amyloid-like assembly of peptide nanomaterials and confers enzyme-like activity.

Amyloid-like assembly is not only associated with pathological events, but also leads to the development of novel nanomaterials with unique properties. Herein, using Fmoc diphenylalanine peptide (Fmoc-F-F) as a minimalistic model, we found that histidine can modulate the assembly behavior of Fmoc-F-F and induce enzyme-like catalysis. Specifically, the presence of histidine rearranges the ß structure of Fmoc-F-F to assemble nanofilaments, resulting in the formation of active site to mimic peroxidase-like activity that catalyzes ROS generation. A similar catalytic property is also observed in Aß assembled filaments, which is correlated with the spatial proximity between intermolecular histidine and F-F. Notably, the assembled Aß filaments are able to induce cellular ROS elevation and damage neuron cells, providing an insight into the pathological relationship between Aß aggregation and Alzheimer's disease. These findings highlight the potential of histidine as a modulator in amyloid-like assembly of peptide nanomaterials exerting enzyme-like catalysis.