Characteristics of soil nitrogen and phosphorus fractions and microbial traits with increasing stand age in two-layered Cunninghumia lanceolata + Phoebe bournei plantations.

Soil nitrogen and phosphorus are two key elements limiting tree growth in subtropical areas. Understanding the regulation of soil microorganisms on nitrogen and phosphorus nutrition is beneficial to reveal maintenance mechanism of soil fertility in plantations. We analyzed the characteristics of soil nitrogen and phosphorus fractions, soil microbial community composition and function, and their relationship across three stands of two-layered Cunninghumia lanceolata + Phoebe bournei with different ages (4, 7 and 11 a) and the pure C. lanceolata plantation. The results showed that the contents of most soil phosphorus fractions increased with increasing two-layered stand age. The increase in active phosphorus fractions with increasing stand age was dominated by the inorganic phosphorus (9.9%-159.0%), while the stable phosphorus was dominated by the organic phosphorus (7.1%-328.4%). The content of soil inorganic and organic nitrogen also increased with increasing two-layered stand age, with NH4+-N and acid hydrolyzed ammonium N contents showing the strongest enhancement, by 152.9% and 80.2%, respectively. With the increase of stand age, the composition and functional groups of bacterial and fungal communities were significantly different, and the relative abundance of some dominant microbial genera (such as Acidothermus, Saitozyma and Mortierella) increased. The relative abundance of phosphorus solubilization and mineralization function genes, nitrogen nitrification function and aerobic ammonia oxidation function genes tended to increase. The functional taxa of fungi explained 48.9% variation of different phosphorus fractions. The conversion of pure plantations to two-layered mixed plantation affected soil phosphorus fractions transformation via changing the functional groups of saprophytes (litter saprophytes and soil saprophytes). Changes in fungal community composition explained 45.0% variation of different nitrogen fractions. Some key genera (e.g., Saitozyma and Mortierella) play a key role in promoting soil nitrogen transformation and accumulation. Therefore, the conversion of pure C. lanceolata plantation to two-layered C. lanceolata + P. bournei plantation was conducive to improving soil nitrogen and phosphorus availability. Bacteria and fungi played important roles in the transformation process of soil nitrogen and phosphorus forms, with greater contribution of soil fungi.

Effects of community structure of Cunninghamia lanceolata sprouting forests with different densities on ecosystem carbon density at the early stage of succession.

To explore potential responses of ecosystem carbon density to changes of community structure during natural regeneration of woody plants, we analyzed the relationships between ecosystem carbon density and its components, tree species diversity, structural diversity (CVDBH) and spatial structure parameters (mingling, aggregation, dominance, crowding) of Cunninghamia lanceolata forests with different sprouting densities (1154, 847 and 465 individuals·hm-2) at the early stage of succession in Baishanzu National Park. The results showed that tree species diversity (species richness index and Shannon diversity index) increased with the decrease of sprouting density of C. lanceolata. Among the stand structural parameters, CVDBH, stand density, and mingling increased with the decrease of sprouting density of C. lanceolata. The stand distribution pattern of different C. lanceolata densities was uniform, with sub-dominant stand growth status and relatively dense status. The carbon density of tree layer under high, medium, and low sprouting densities of C. lanceolata were 57.56, 56.12 and 46.54 t·hm-2, soil carbon density were 104.35, 122.71 and 142.00 t·hm-2, and the total carbon density of ecosystem were 164.59, 182.41 and 190.13 t·hm-2, respectively. There was little variation in carbon density of understory layer and litter layer among different treatments. The carbon density distribution characteristics of different C. lanceolata densities were following the order of soil layer (63.4%-74.7%) > tree layer (24.5%-35.0%) > understory layer and litter layer (0.8%-2.0%). The results of variance partitioning analysis indicated that the change of tree layer carbon density was mainly influenced by stand structure diversity, soil layer carbon density was influenced by both tree species diversity and stand structure diversity, while ecosystem carbon density was mainly influenced by tree species diversity. Stand spatial structure parameters had a relatively little effect on ecosystem carbon density and its components. The sprouting density of C. lanceolata significantly affected ecosystem carbon accumulation during the conversion from C. lanceolata plantations to natural forests. A lower remaining density of C. lanceolata (about 500 individuals·hm-2) was more conducive to forest carbon sequestration.

Swimming behavior indicates stress and adaptations to exercise.

Introduction: Behaviors of swimming rodents are not uniform, exhibiting large variations, which may underlie the individual differences in swimming exercise-induced benefits. The study aimed to monitor individualized swimming behavior and evaluate its biological significance. Methods: A swimming tank which can monitor individualized rodent swimming behavior during exercise was established. A total of 45 mice were subjected to swimming training for 1 month (1 h per day) and the swimming behaviors of each mouse were recorded. Results: The swimming behaviors of mice displayed considerable variations in aspects of distance, velocity, and area preference. For example, nearly one-third of mice preferred to swim in central area and most of the mice exhibited an even area distribution. Long-term exercise training improved cardiac systolic function and decreased blood pressure in mice, but hardly changed swimming behaviors. Analyses of the relationship between swimming behavior and cardiovascular adaptations to exercise training revealed that swimming behavior indicated the biological effects of swimming training. Specifically, mice which preferred swimming at the central zone or were trainable in behavior during 1-month training exhibited better outcomes in cardiac function and blood pressure post long-term exercise. Mechanistically, a centralized swimming behavior indicated a smaller stress during exercise, as evidenced by a milder activation of hypothalamic-pituitary-adrenal axis. Discussion: These results suggest that swimming behavior during training indicates individualized adaptations to long-term exercise, and highlight a biological significance of swimming behavior monitoring in animal studies.

Daxx knockdown promoted rDNA transcription without impairing H3.3 expression in mouse preimplantation embryos.

During fertilization, DAXX (death domain-associated protein) mediates histone variant H3.3 incorporation into heterochromatin, which plays an important role in the maintenance of genomic integrity. rDNA, the ribosomal gene, is included in the first wave of gene activation after fertilization. Our and other studies indicated that loss of Daxx disturbs rDNA heterochromatinization and promotes rDNA transcription without change in protein expression of H3.3. However, maternal and zygotic deletion of Daxx impairs blastocyst development. Whether Daxx knockdown affects H3.3 expression and improves the rDNA transcription in preimplantation development has not been reported. In the present study, we injected HA-labelled H3.3 (H3.3-HA) into oocytes during ICSI procedure, and detected H3.3 and DAXX by immunofluorescent staining. Then, we knockdowned Daxx and detected the gene expression levels of Daxx, H3.3, 18s and 47s rRNA. We also performed immunofluorescent staining of B23, γH2A and EdU incorporation to demonstrate nuclear structure, DNA damage and replication. We found injection of H3.3-HA did not impair preimplantation development. Daxx siRNA did not change expression of H3.3 mRNA, and the development of two-cell embryos and blastocysts, but the overall replication and expression levels of rRNA were increased compared with that in the control group. Finally, knockdown of DAXX did not aggravate the DNA damage but loosened the nucleolus. We concluded that Daxx knockdown promoted DNA replication and rDNA transcription, but did not affect H3.3 expression and subsequent preimplantation development.

Surface Treat Method to Improve the Adhesion between Stainless Steel and Resin: A Review.

Combining metal and polymer into hybrid composite materials is finding increasing interest in many industries. Special attention is being paid to increase the adhesion between the metal and polymer interface. In this paper, the current research progress of surface treatment methods for improving the interfacial adhesion of stainless steel and resin is reviewed. It involves the stainless steel surface treatment method, resin surface treatment method, and adhesion test methods of stainless steel and resin. The methods of improving the interfacial adhesion of stainless steel and resin are summarized and prospected according to the research status.

Dietary Methionine Restriction Improves Gastrocnemius Muscle Glucose Metabolism through Improved Insulin Secretion and H19/IRS-1/Akt Pathway in Middle-Aged Mice.

Methionine restriction (MR) improves glucose metabolism. In skeletal muscle, H19 is a key regulator of insulin sensitivity and glucose metabolism. Therefore, this study aims to reveal the underlying mechanism of H19 upon MR on glucose metabolism in skeletal muscle. Middle-aged mice were fed MR diet for 25 weeks. Mouse islets ß cell line ß-TC6 cells and mouse myoblast cell line C2C12 cells were used to establish the apoptosis or insulin resistance model. Our findings showed that MR increased B-cell lymphoma-2 (Bcl-2) expression, deceased Bcl-2 associated X protein (Bax), cleaved cysteinyl aspartate-specific proteinase-3 (Caspase-3) expression in pancreas, and promoted insulin secretion of ß-TC6 cells. Meanwhile, MR increased H19 expression, insulin Receptor Substrate-1/insulin Receptor Substrate-2 (IRS-1/IRS-2) value, protein Kinase B (Akt) phosphorylation, glycogen synthase kinase-3ß (GSK3ß) phosphorylation, and hexokinase 2 (HK2) expression in gastrocnemius muscle and promoted glucose uptake in C2C12 cells. But these results were reversed after H19 knockdown in C2C12 cells. In conclusion, MR alleviates pancreatic apoptosis and promotes insulin secretion. And MR enhances gastrocnemius muscle insulin-dependent glucose uptake and utilization via the H19/IRS-1/Akt pathway, thereby ameliorating blood glucose disorders and insulin resistance in high-fat-diet (HFD) middle-aged mice.

Fungal diversity dominates the response of multifunctionality to the conversion of pure plantations into two-aged mixed plantations.

Plantation forests are essential in driving global biogeochemical cycling and mitigating climate change. Biodiversity and environmental factors can shape multiple forest ecosystem functions simultaneously (i.e., multifunctionality). However, their effect on multifunctionality when pure plantations are converted into two-aged plantations remains underexplored. Therefore, we assessed above- and below-ground biodiversity and environmental factors and 11 ecosystem functions in different plantation types in subtropical China. The two-aged mixed plantations exhibited higher multifunctionality than did a pure plantation, primarily due to soil fungal diversity and secondarily due to tree diversity, based on the coefficient of variation for tree diameter at breast height (CVD) and community-weighted specific leaf area (CWMSLA). Further analysis revealed saprotrophy as the key soil fungal trophic mode in maintaining multifunctionality. Moreover, structural equation modeling confirmed that soil environmental factors, namely the soil water content and pH, had no direct association with multifunctionality, but were indirectly related to multifunctionality via elevated CVD and CWMSLA, respectively. Our results indicate that the tree and soil fungal diversity, as well as soil environmental factors, resulting from the conversion of pure plantations to two-aged mixed plantations, can enhance multifunctionality, and provide a better comprehensive understanding of the driving mechanisms of multifunctionality, leading to the sustainable management of subtropical plantation forest ecosystems.

Methionine-Restricted Diet: A Feasible Strategy Against Chronic or Aging-Related Diseases.

Dietary methionine restriction (MR) has been associated with multifaceted health-promoting effects. MR is conducive to prevention of several chronic diseases and cancer, and extension of lifespan. A growing number of studies on new phenotypes and mechanisms of MR have become available in the past five years, especially in angiogenesis, neurodegenerative diseases, intestinal microbiota, and intestinal barrier function. In this review, we summarize the characteristics and advantages of MR, and current knowledge on the physiological responses and effects of MR on chronic diseases and aging-associated pathologies. Potential mechanisms, in which hydrogen sulfide, fibroblast growth factor 21, gut microbiota, short-chain fatty acids, and so on are involved, are discussed. Moreover, directions for epigenetics and gut microbiota in an MR diet are presented in future perspectives. This review comprehensively summarizes the novel roles and interpretations of the mechanisms underlying MR in the prevention of chronic diseases and aging.

Electrophilic components from Xiaoheiyao (rhizomes of Inula nervosa Wall.) alleviate the production of heterocyclic aromatic amines via creatinine inhibition.

Xiaoheiyao is the rhizome of Inula nervosa Wall., a traditional spice and medicinal herb in China. In this study, the creatinine inhibitor from Xiaoheiyao extract and also the effects and mechanism on the production of heterocyclic aromatic amines (HAAs) were investigated. Xiaoheiyao extract inhibited the total contents of seven detected HAAs in grilled beef patties, particularly aminoimidazole-azaarenes (AIAs) in a dose-dependent manner, reaching a maximum inhibition rate of 62% for total HAAs and 73% for AIAs. The most effective subfraction of Xiaoheiyao extract (IER80) contained abundant potential creatinine inhibitors, as revealed by immobilized creatinine probe, HPLC and UPLC-MS/MS analyses. Moreover, electrophilic p-coumaric acid derivatives were discovered from IER80 by feature based molecular networking. p-Coumaric acid was demonstrated to inhibit the contents of total HAAs and AIAs in grilled beef patties and model system. Quantitative analyses of the precursor and intermediates of AIAs in model system revealed that p-coumaric acid mainly affected the generation of AIAs by inhibiting creatinine.

The Alleviation of Dextran Sulfate Sodium (DSS)-Induced Colitis Correlate with the logP Values of Food-Derived Electrophilic Compounds.

Food-derived electrophilic compounds (FECs) are small molecules with electrophilic groups with potential cytoprotective effects. This study investigated the differential effects of six prevalent FECs on colitis in dextran sodium sulfate (DSS)-induced mice and the underlying relationship with molecular characteristics. Fumaric acid (FMA), isoliquiritigenin (ISO), cinnamaldehyde (CA), ferulic acid (FA), sulforaphane (SFN), and chlorogenic acid (CGA) exhibited varying improvements in colitis on clinical signs, colonic histopathology, inflammatory and oxidative indicators, and Nrf2 pathway in a sequence of SFN, ISO > FA, CA > FMA, CGA. Representative molecular characteristics of the "penetration-affinity−covalent binding" procedure, logP value, Keap1 affinity energy, and electrophilic index of FECs were theoretically calculated, among which logP value revealed a strong correlation with colitis improvements, which was related to the expression of Nrf2 and its downstream proteins. Above all, SFN and ISO possessed high logP values and effectively improving DSS-induced colitis by activating the Keap1−Nrf2 pathway to alleviate oxidative stress and inflammatory responses.

Identification of the Fungal Community in Otomycosis by Internal Transcribed Spacer Sequencing.

We used internal transcribed spacer (ITS) sequencing to identify the fungal community in otomycosis patients and to evaluate the treatment effects of bifonazole. Ten patients who visited the Department of Otolaryngology of Jiangsu Provincial Hospital on Integration of Chinese and Western Medicine from May 2020 to April 2021 were recruited. Otomycosis patients were treated with bifonazole solution once a day for 14 days. Samples collected from the external auditory canal before and after treatment (Pre-treatment, n = 14 ears; Post-treatment, n = 14 ears) were used for microscopic examination, fungal culture, and ITS sequencing. Samples collected from 10 volunteers (Control, n = 20 ears) were used as controls. The symptoms, including ear itching, aural fullness, otalgia, hearing loss, and physical signs were recorded before treatment as well as on the 7th and 14th days after treatment. Aspergillus was identified as a main pathogenic fungus by microscopic examination, fungal culture, and ITS sequencing. At the genus level, Aspergillus was more abundant in the pre-treatment group than the control and post-treatment groups, and Malassezia was more abundant in the control and post-treatment groups than the pre-treatment group. The fungal species richness and diversity reduced significantly in the pre-treatment group compared with the control and post-treatment groups. The effective rate of bifonazole was 64.29% and 100% on the 7th and 14th days after treatment, respectively. In conclusion, the results obtained from morphologic studies and ITS sequencing indicate that Aspergillus is the main pathogenic fungus of otomycosis patients in Nanjing, Jiangsu Province, China. Malassezia is the dominant resident fungi in healthy individuals. ITS sequencing provides comprehensive information about fungal community in otomycosis and is helpful in evaluating the efficacy of antifungal agents.

Effects of Ejiao peptide-iron chelates on intestinal inflammation and gut microbiota in iron deficiency anemic mice.

Iron deficiency is a global nutritional problem that adversely affects the functional regulation of the immune system. In the process of treatment through iron supplementation, the problem of excessive iron intake often occurs, which increases the level of inflammation in the body. Excessive iron can also lead to an increase in intestinal iron-requiring pathogenic bacteria and an imbalance of intestinal flora. In this study, we aim to explore the effect of Ejiao peptide-iron (EPI) chelates on the intestinal flora and inflammation of ICR mice having iron-deficiency anemia (IDA). The mice were given low, medium, and high doses of EPI and FeSO4 (1.0, 2.0 and 3.0 mg Fe per kg weight, respectively) daily for 4 weeks by intragastric administration. IDA mice showed increased inflammation levels and decreased sIgA secretion, which were restored after intervention with EPI at different doses. Intestinal mucosal ulcers, inflammatory cell infiltration, and oxidative stress in the colon tissue were reduced, and intestinal permeability was improved. Furthermore, 16S rDNA gene sequencing revealed that EPI increased microbial diversity and richness, changing the community structure, therefore, alleviating microbiota dysbiosis caused by IDA (e.g. the proportion of Firmicutes/Bacteroides). Different from the traditional iron supplement FeSO4, when the pathogenic bacteria (e.g. Helicobacter and Erysipelatoclostridium) increase and the beneficial bacteria (e.g. Bifidobacterium and Blautia) decrease at high doses, EPI shows higher safety at a high dose, thereby maintaining a healthier intestinal homeostasis.

[Geographical variation of growth traits among different Quercus acutissima provenances]. / ä¸åŒç§æºéº»æ Žç”Ÿé•¿æ€§çŠ¶çš„åœ°ç†å˜å¼‚.

The variations in plant growth of 32 Quercus acutissima provenances in three sites (Yongfeng, Jiangxi; Kaihua, Zhejiang and Chuzhou, Anhui) were studied. The AMMI model was used to analyze the stability of growth traits and to select the best provenances. The results showed that tree height, diameter at breast (ground) height, and aboveground biomass (AGB) per individual of the provenances were significantly different in the three sites. The AGB per individual was significantly affected by site, provenance, and the interaction of provenance × site. Site had the greatest impact on the variation of tree growth, followed by provenance and provenance × site. The growth performance of these superior provenances in different sites varied greatly in the seedling stage (1-3 years old) and young forest stage (4-11 years old). Based on the AGB per individual in the 11st year, the best provenances were selected in each site. Seven superior provenances of Yongfeng, Jiangxi were selected, with the average AGB per individual increased by 15.6%-57.8% compared with the ave-rage value. Seven superior provenances of Kaihua, Zhejiang were selected, with the average AGB per individual increased by 19.2%-45.2%. Eight superior provenances of Chuzhou, Anhui were selected,with the average AGB per individual increased by 24.9%-63.3%. According to the growth performance and stability, four superior provenances were selected to develop short-rotation charcoal forest cultivation across three sites, with an average AGB per individual of 36.55 kg and an average stability parameter of 0.97.

Epigenetic Mechanism of Enrichment of A549 Lung Cancer Stem Cells with 5-Fu.

BACKGROUND: The influence of 5-fluorouracil (5-Fu) and cisplatin (CDDP) on the A549 and NCI-H226 cells was studied, and the epigenetic mechanism of enrichment of A549 lung cancer stem cells with 5-Fu was explored. MATERIALS AND METHODS: The cell proliferation of both A549 and NCI-H226 was detected by BrdU assay, and apoptosis condition was measured by flow cytometric analysis. The expressions of OCT3/4 and Nanog in cells treated with 5-Fu or CDDP were measured by immunofluorescence, Western blot and qPCR. qPCR was also performed to determine the relative expression of methyltransferase genes and miRNA. Sequencing after bisulfite treatment (BSP) was employed to detect the methylation of OCT3/4 promoter in A549 cells. And ChIP was conducted to detect the expression of H3K9Me3 and H3K9Ace. RESULTS: Both 5-Fu and CDDP result in the apoptosis of A549 and NCI-H226 cells and improve the expressions of has-miR-134 and has-miR-296. However, 5-Fu enhances the expression of OCT3/4 in A549 cells, and the change of methyltransferase genes and BSP results suggested some genetic differences between CDDP and 5-Fu treatment in A549 cells. ChIP assay showed that the expression of H3K9Me3 significantly decreased and H3K9Ace significantly increased in A549 cells. CONCLUSION: The enrichment effect of CDDP on A549 and NCI-H226 carcinoma stem cells is inconsistent with the enrichment effect of 5-Fu. The enrichment of A549 lung cancer stem cells with 5-Fu might be related to the methylation of OCT3/4 promoter and the expression of H3K9Me3 and H3K9Ace.

Chemical Space Charting of Different Parts of Inula nervosa Wall.: Upregulation of Expression of Nrf2 and Correlated Antioxidants Enzymes.

The edible and medicinal part of Inula nervosa Wall. (Xiaoheiyao) is confined to its root without sufficient phytochemical and biological investigation. In this study, the secondary metabolites of root, stem, leaf, and flower of I. nervosa Wall. were visualized using Global Natural Products Social Molecular Networking (GNPS), MolNetEnhancer, XCMS(xcmsonline.scripps.edu) analysis, and `ili mapping based on high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) data to reveal their chemical differences. Among the 11 kinds of chemical repertoires annotated by MolNetEnhancer and 16 hits against the GNPS library, 10-isobutyryloxy-8,9-epoxythymol isobutyrate (1) was revealed as the most dominant and responsible marker between the roots and the other parts. Moreover, a battery of unique MS features as well as differential markers were discovered from different parts of the plant. The chemical differences contribute to the bioactivity differences, which presented in the 2,2-diphenyl-1-picryl-hydrazyl (DPPH)assay and H2O2-insulted HepG2 cells and were in significant correlations with the contents of 1. real-time reverse transcription polymerase chain reaction (RT-PCR)results demonstrated that I. nervosa Wall. extracts upregulated the mRNA expression of nuclear factor E2-related factor 2(Nrf2), heme oxygenase 1(HO-1), NAD(P)H quinone dehydrogenase 1 (NQO1), manganese superoxide dismutase (MnSOD), and glutamate-cysteine ligase catalytic subunit (GCLC) actors involved in antioxidative response in H2O2-challenged HepG2 cells. These findings support the roots of I. nervosa Wall. as active parts of Xiaoheiyao, and also indicate the potential antioxidant activities of other parts.

Flavor Components Comparison between the Neck Meat of Donkey, Swine, Bovine, and Sheep.

Donkey in China is well known for its draft purpose and transportation; however, donkey meat has attracted more and more consumers in recent years, yet it lacks sufficient information on its flavor components compared to other main meats. Therefore, in this study, volatile flavor compounds in neck meat of donkey, swine, bovine, and sheep were classified by electronic nose, then confirmed and quantified by gas chromatography-mass spectrometry. High-performance liquid chromatography (HPLC) and gas chromatography were used to quantify free fatty acid, amino acid, and flavor nucleotide. A total of 73 volatile compounds were identified, and aldehydes were identified as the characteristic flavor compounds in neck meat of donkey, bovine, swine and sheep in proportion of 76.39%, 46.62%, 31.64%, and 35.83%, respectively. Particularly, hexanal was the most abundant volatile flavor. Compared with other neck meat, much higher unsaturated free fatty acids were present in donkeys. Furthermore, neck meat of donkeys showed essential amino acid with highest content. Thus, special flavor and nutrition in donkey neck meat make it probably a candidate for consumers in other regions besides Asia.

Dietary Methionine Restriction Ameliorated Fat Accumulation, Systemic Inflammation, and Increased Energy Metabolism by Altering Gut Microbiota in Middle-Aged Mice Administered Different Fat Diets.

Diet greatly influences gut microbiota. Dietary methionine restriction (MR) prevents and ameliorates age-related or high-fat-induced diseases and prolongs life span. This study aimed to reveal the impact of MR on gut microbiota in middle-aged mice with low-, medium-, high-fat diets. C57BL/6J mice were randomly divided into six groups with different MR and fat-content diets. Multiple indicators of intestinal function, fat accumulation, energy consumption, and inflammation were measured. 16S rRNA gene sequencing was used to analyze cecal microbiota. Our results indicated that MR considerably reduced the concentrations of lipopolysaccharide (LPS) and increased short-chain fatty acids (SCFAs) by upregulating the abundance of Corynebacterium and SCFA-producing bacteria Bacteroides, Faecalibaculum, and Roseburia and downregulating the LPS-producing or proinflammatory bacteria Desulfovibrio and Escherichia-Shigella. The effect of MR on LPS and SCFAs further reduced fat accumulation and systemic inflammation, enhanced heat production, and mediated the LPS/LBP/CD14/ TLR4 pathway to strength the intestinal mucosal immunity barrier in middle-aged mice.

Structural characterization of an active polysaccharide of longan and evaluation of immunological activity.

An active polysaccharide (LPD2) was isolated from longan pulp by comparing the effects of polysaccharides on the phagocytosis of macrophages. LPD2 was composed of arabinose, mannose, glucose, and galactose in a molar ratio of 0.25:0.49:1:0.5 with average molecular weight of 9.64 × 106 Da. The main linkages of the sugar residues of LPD2 were (1→4)-ß-Glc and (1→6)-ß-Man. LPD2 significantly enhanced the lymphocytes proliferation, phagocytosis and NO and IL-6 secretion by macrophage. The anti-TLR2 and anti-TLR4 mAbs markedly suppressed LPD2-mediated NO and IL-6 production. Furthermore, anti-TLR4 or anti-TLR2 plus anti-TLR4 treatment significantly decreased LPD2-induced increase of MyD88, IRAK4, TRAF6 and INOS mRNA expression. Moreover, western blotting analysis showed that LPD2 enhanced the expression of target proteins in MyD88/IRAK4-TRAF6- INOS pathways. These results suggested that LPD2 induced macrophage activation partly via the TLR2- and TLR4-mediated MyD88/IRAK4-TRAF6 signaling pathways. Knowing the structural features and activities of active polysaccharide of longan gives the insights into longan polysaccharide application as an immunomodulatory agent.

Dietary methionine restriction reduces hepatic steatosis and oxidative stress in high-fat-fed mice by promoting H2S production.

Methionine is an essential amino acid that plays important roles in mammalian metabolism. Interestingly, previous studies have consistently shown that a methionine-restricted diet (MRD) reduces hepatic lipid levels, reactive oxygen species production, and oxidative stress damage. However, the mechanisms responsible for these beneficial effects are unknown. Therefore, our study was aimed at investigating the hepatic systemic metabolic responses to MRD in high-fat-diet (HFD) mice and to clarify the possible mechanisms of such responses. C57BL/6J mice were fed a control diet (0.86% methionine + 4% fat), HFD (0.86% methionine + 20% fat), or MRD (0.17% methionine + 20% fat) for 22 consecutive weeks, and euthanized at week 11 or week 22. Our results showed that HFD inhibited hepatic energy expenditure, induced steatosis and oxidative stress, and decreased hydrogen sulfide (H2S) production in the mouse liver. MRD reduced the body weight, liver fat percentage, and plasma and hepatic lipid profiles. Moreover, MRD decreased lipid synthesis, increased energy metabolism (e.g. lipid catabolism and fatty acid oxidation, glycolysis and tricarboxylic acid cycle metabolism, and amino acid catabolism), enhanced the activity of antioxidant enzymes, and reduced the levels of oxidative damage products and purine metabolism in the liver. Furthermore, MRD up-regulated the hepatic gene and protein expression of cystathionine-γ-lyase (CSE), elevated the hepatic CSE activity, and promoted hepatic H2S production. These findings suggest that MRD can ameliorate the hepatic metabolic disorders induced by HFD and especially reduce hepatic steatosis and oxidative stress likely through increasing hepatic H2S production.

[Dityrosine administration induces myocardium injury and inflammatory response in mice].

OBJECTIVE: To study the effects of oxidized tyrosine products and dityrosine on the myocardial injury and inflammatory response in 10-week-gavaged mice. METHODS: A total of 30 female Kunming mice were assigned to three groups: gavagedwith saline( Con), oxidized tyrosine products( O-Tyr) and dityrosine( Dityr) for 320µg/kg BW for 10 weeks. Levels of oxidized protein products( DT, AOPPs, 3-NT) and lipid peroxidation products( MDA), oxidative stress( T-AOC and GSH/GSSG), markers of myocardium injury( CK, CK-MB, cTnI and Ca~(2+)-ATPase), markers of inflammatory factor( CRP and TNF-α) were investigated and the genes related to inflammatory response were detected by Real-time quantitative( PCR). RESULTS: 10 weeks of gavage experiments enhanced the levels of dityrosine( DT), advanced oxidation protein products( AOPPs), 3-nitrotyrosine( 3-NT), and malondialdehyde( MDA), and decreased total antioxidant capacity( T-AOC) and the ratio of reduced glutathione to oxidized glutathione( GSH/GSSG) in mice plasma and myocardium. Besides, O-Tyr and Dityr increased the levels of creatine kinase( CK), creatine kinase isoenzymes( CK-MB), cardiac troponin I( cTnI) in plasma anddecreased the activities of Ca~(2+)-ATPase in myocardium. O-Tyr and Dityr increased the levels of C-reactive protein( CRP) and tumour necrosis factor α( TNF-α) in plasma. The gene expression of inflammatory response were up-regulated. CONCLUSION: O-Tyr and Dityr increase the accumulation of myocardial protein oxidation and lipid peroxidation products and induce oxidative damage to myocardium. O-Tyr and Dityr may cause myocardial tissue injury and inflammatory response. Dityrosine, as the main component of tyrosine oxidative products, may play a major role in the process of oxidized tyrosine products causing myocardial injury in mice.