Sterol Regulatory Element Binding Protein 1: A Mediator for High-Fat Diet-Induced Hepatic Gluconeogenesis and Glucose Intolerance in Fish.

BACKGROUND: Sterol regulatory element binding protein (SREBP) 1 is considered to be a crucial regulator for lipid synthesis in vertebrates. However, whether SREBP1 could regulate hepatic gluconeogenesis under high-fat diet (HFD) condition is still unknown, and the underlying mechanism is also unclear. OBJECTIVES: This study aimed to determine gluconeogenesis-related gene and protein expressions in response to HFD in large yellow croaker and explore the role and mechanism of SREBP1 in regulating the related transcription and signaling. METHODS: Croakers (mean weight, 15.61 ± 0.10 g) were fed with diets containing 12% crude lipid [control diet (ND)] or 18% crude lipid (HFD) for 10 weeks. The glucose tolerance, insulin tolerance, hepatic gluconeogenesis-related genes, and proteins expressions were determined. To explore the role of SREBP1 in HFD-induced gluconeogenesis, SREBP1 was inhibited by pharmacologic inhibitor (fatostatin) or genetic knockdown in croaker hepatocytes under palmitic acid (PA) condition. To explore the underlying mechanism, luciferase reporter and chromatin immunoprecipitation assays were conducted in HEK293T cells. Data were analyzed using analysis of variance or Student t test. RESULTS: Compared with ND, HFD increased the mRNA expressions of gluconeogenesis genes (2.40-fold to 2.60-fold) (P < 0.05) and reduced protein kinase B (AKT) phosphorylation levels (0.28-fold to 0.34-fold) (P < 0.05) in croakers. However, inhibition of SREBP1 by fatostatin addition or SREBP1 knockdown reduced the mRNA expressions of gluconeogenesis genes (P < 0.05) and increased AKT phosphorylation levels (P < 0.05) in hepatocytes, compared with that by PA treatment. Moreover, fatostatin addition or SREBP1 knockdown also increased the mRNA expressions of irs1 (P < 0.05) and reduced serine phosphorylation of IRS1 (P < 0.05). Furthermore, SREBP1 inhibited IRS1 transcriptions by binding to its promoter and induced IRS1 serine phosphorylation by activating diacylglycerol-protein kinase Cε signaling. CONCLUSIONS: This study reveals the role of SREBP1 in hepatic gluconeogenesis under HFD condition in croakers, which may provide a potential strategy for improving HFD-induced glucose intolerance.

Dietary palm oil enhances Sterol regulatory element-binding protein 2-mediated cholesterol biosynthesis through inducing endoplasmic reticulum stress in muscle of large yellow croaker (Larimichthys crocea).

Sterol regulatory element-binding protein 2 (SREBP2) is considered to be a major regulator to control cholesterol homoeostasis in mammals. However, the role of SREBP2 in teleost remains poorly understand. Here, we explored the molecular characterisation of SREBP2 and identified SREBP2 as a key modulator for 3-hydroxy-3-methylglutaryl-coenzyme A reductase and 7-dehydrocholesterol reductase, which were rate-limiting enzymes of cholesterol biosynthesis. Moreover, dietary palm oil in vivo or palmitic acid (PA) treatment in vitro elevated cholesterol content through triggering SREBP2-mediated cholesterol biosynthesis in large yellow croaker. Furthermore, our results also found that PA-induced activation of SREBP2 was dependent on the stimulating of endoplasmic reticulum stress (ERS) in croaker myocytes and inhibition of ERS by 4-Phenylbutyric acid alleviated PA-induced SREBP2 activation and cholesterol biosynthesis. In summary, our findings reveal a novel insight for understanding the role of SREBP2 in the regulation of cholesterol metabolism in fish and may deepen the link between dietary fatty acid and cholesterol biosynthesis.

Regulation of low-density lipoprotein on lipid metabolism in macrophages of large yellow croaker (Larimichthys crocea).

Low-density lipoprotein (LDL) is the main carrier of cholesterol transport in plasma, which participates in regulating lipid homeostasis. Studies in mammals have shown that high levels of LDL in plasma absorbed by macrophages trigger the formation of lipid-rich foam cells, leading to the development of atherosclerotic plaques. Although lipid-rich atherosclerosis-like lesions have been discovered in the aorta of several fish species, the physiological function of LDL in fish macrophages remains poorly understood. In the present study, LDL was isolated from the plasma of large yellow croaker (Larimichthys crocea), and mass spectrometry analysis identified two truncated forms of apolipoprotein B100 in the LDL protein profile. Transcriptomic analysis of LDL-stimulated macrophages revealed that differentially expressed genes (DEGs) were enriched in various pathways related to lipid metabolism, as confirmed by the fact that LDL increased total cholesterol and cholesteryl esters content. Meanwhile, the gene and protein expression levels of perilipin2 (PLIN2), a DEG enriched in the PPAR signaling pathway, were upregulated in response to LDL stimulation. Importantly, knocking down plin2 significantly attenuates LDL-induced cholesterol accumulation and promotes cholesterol efflux. Furthermore, the transcription factor PPARγ, which is upregulated in response to LDL stimulation, can enhance the promoter activity of plin2. In conclusion, this study suggests that LDL may upregulate plin2 expression through PPARγ, resulting in cholesterol accumulation in fish macrophages. This study will facilitate the investigation of the function of LDL in regulating lipid homeostasis in macrophages and shed light on the evolutionary origin of LDL metabolism in vertebrates.

Phosphatidylethanolamine alleviates OX-LDL-induced macrophage inflammation by upregulating autophagy and inhibiting NLRP1 inflammasome activation.

Oxidized low-density lipoprotein (OX-LDL)-induced inflammation and autophagy dysregulation are important events in the progression of atherosclerosis. Phosphatidylethanolamine (PE), a multifunctional phospholipid that is enriched in cells, has been proven to be directly involved in autophagy which is closely associated with inflammation. However, whether PE can influence OX-LDL-induced autophagy dysregulation and inflammation has not been reported. In the present study, we revealed that OX-LDL significantly induced macrophage inflammation through the CD36-NLRP1-caspase-1 signaling pathway in fish. Meanwhile, cellular PE levels were significantly decreased in response to OX-LDL induction. Based on the relationship between PE and autophagy, we then examined the effect of PE supplementation on OX-LDL-mediated autophagy impairment and inflammation induction in macrophages. As expected, exogenous PE restored impaired autophagy and alleviated inflammation in OX-LDL-stimulated cells. Notably, autophagy inhibitors reversed the inhibitory effect of PE on OX-LDL-induced maturation of IL-1ß, indicating that the regulation of PE on OX-LDL-induced inflammation is dependent on autophagy. Furthermore, the positive effect of PE on OX-LDL-induced inflammation was relatively conserved in mouse and fish macrophages. In conclusion, we elucidated the role of the CD36-NLRP1-caspase-1 signaling pathway in OX-LDL-induced inflammation in fish and revealed for the first time that altering PE abundance in OX-LDL-treated cells could alleviate inflammasome-mediated inflammation by inducing autophagy. Given the relationship between OX-LDL-induced inflammation and atherosclerosis, this study prompts that the use of PE-rich foods promises to be a new strategy for atherosclerosis treatment in vertebrates.

Glycerol monolaurate improved intestinal barrier, antioxidant capacity, inflammatory response and microbiota dysbiosis in large yellow croaker (Larimichthys crocea) fed with high soybean oil diets.

Glycerol monolaurate (GML) is a potential candidate for regulating metabolic syndrome and inflammatory response. However, the role of GML in modulating intestinal health in fish has not been well determined. In this study, a 70-d feeding trial was conducted to evaluate the effect of GML on intestinal barrier, antioxidant capacity, inflammatory response and microbiota community of large yellow croaker (13.05 ± 0.09 g) fed with high level soybean oil (SO) diets. Two basic diets with fish oil (FO) or SO were formulated. Based on the SO group diet, three different levels of GML 0.02% (SO0.02), 0.04% (SO0.04) and 0.08% (SO0.08) were supplemented respectively. Results showed that intestinal villus height and perimeter ratio were increased in SO0.04 treatment compared with the SO group. The mRNA expressions of intestinal physical barrier-related gene odc and claudin-11 were significantly up-regulated in different addition of GML treatments compared with the SO group. Fish fed SO diet with 0.04% GML addition showed higher activities of acid phosphatase and lysozyme compared with the SO group. The content of malonaldehyde was significantly decreased and activities of catalase and superoxide dismutase were significantly increased in 0.02% and 0.04% GML groups compared with those in the SO group. The mRNA transcriptional levels of inflammatory response-related genes (il-1ß, il-6, tnf-α and cox-2) in 0.04% GML treatment were notably lower than those in the SO group. Meanwhile, sequencing analysis of bacterial 16S rRNA V4-V5 region showed that GML addition changed gut microbiota structure and increased alpha diversity of large yellow croaker fed diets with a high level of SO. The correlation analysis results indicated that the change of intestinal microbiota relative abundance strongly correlated with intestinal health indexes. In conclusion, these results demonstrated that 0.02%-0.04% GML addition could improve intestinal morphology, physical barrier, antioxidant capacity, inflammatory response and microbiota dysbiosis of large yellow croaker fed diets with a high percentage of SO.

Ab Initio Molecular Dynamics Study of H2 Dissociation Mechanisms on Cu13 and Defective Graphene-supported Cu13 Clusters: Active Sites, Energy Barriers and Adsorption States.

Ab initio molecular dynamics calculations were performed to study H2 dissociation mechanisms on Cu13 and defective graphene-supported Cu13 clusters. The study reveals that seven types of corresponding dissociation processes are found on the two clusters. The average dissociation energy barriers are 0.51 eV on the Cu13 cluster and 0.12 eV on the defective graphene-supported Cu13 cluster, which are lowered by ~19 % and ~81 % compared with the pristine Cu(111) surface, respectively. Furthermore, compared with the pure Cu13 cluster, the average dissociation energy barrier on the defective graphene-supported Cu13 cluster is substantially reduced by about 76 %. The preferred dissociation mechanisms on the two clusters are H2 located at a top-bridge site with the barrier heights of 0.30 eV on the Cu13 cluster and -0.31 eV on the defective graphene-supported Cu13 cluster. Analysis of the H-Cu bond interactions in the transition states shows that the antibonding-orbital center shifts upward on the defective graphene-supported Cu13 cluster compared with the one on the Cu13 cluster, which explains the reduction of the dissociation energy barrier. The average adsorption energy of dissociated H atoms is also greatly enhanced on the defective graphene-supported Cu13 cluster, about twice that on the Cu13 cluster.

Effects of supplemental octanoate on hepatic lipid metabolism, serum biochemical indexes, antioxidant capacity and inflammation-related genes expression of large yellow croaker (Larimichthys crocea) fed with high soybean oil diet.

Dietary high soybean oil (SO) levels might cause hepatic lipid deposition, induce oxidative stress and inflammatory response in aquatic animals, while octanoate (OCT) is beneficial to metabolism and health in mammals. However, the effect of OCT has been studied rarely in aquatic animals. In this study, a 10-week feeding trial was conducted to investigate the effect of supplemental OCT on hepatic lipid metabolism, serum biochemical indexes, antioxidant capacity and inflammatory response of large yellow croaker (Larimichthys crocea) fed with high SO levels diet. The negative control diet contained 7% fish oil (FO), while the positive control diet contained 7% SO. The other four experimental diets were supplemented with 0.7, 2.1, 6.3 and 18.9 g/kg sodium octanoate (OCT) based on the positive control diet. Results showed that OCT supplementation effectively reduced the hepatic crude lipid, triglyceride (TG), total cholesterol (TC) and non-esterified free fatty acids contents, and alleviated lipid accumulation caused by the SO diet. Meanwhile, OCT supplementation decreased the serum TG, TC, alanine transaminase, aspartate transaminase and low-density lipoprotein cholesterol levels, increased the serum high-density lipoprotein cholesterol level, improved the serum lipid profiles and alleviated hepatic injury. Furthermore, with the supplementation of OCT, the mRNA expression of genes related to lipogenesis (acc1, scd1, fas, srebp1, dgat1 and cebpα) and fatty acid (FA) transport (fabp3, fatp and cd36) were down-regulated, while the mRNA expression of genes related to lipolysis (atgl, hsl and lpl) and FA ß-oxidation (cpt1 and mcad) were up-regulated. Besides that, dietary OCT increased the total antioxidant capacity, activities of peroxidase, catalase and superoxide dismutase and the content of reduced glutathione, decreased the content of 8-hydroxy-deoxyguanosine and malondialdehyde and relieved hepatic oxidative stress. Supplementation of 0.7 and 2.1 g/kg OCT down-regulated the mRNA expression of genes related to pro-inflammatory cytokines (tnfα, il1ß and ifnγ), and suppressed hepatic inflammatory response. In conclusion, supplementation with 0.7-2.1 g/kg OCT could reduce hepatic lipid accumulation, relieve oxidative stress and regulate inflammatory response in large yellow croaker fed the diet with high SO levels, providing a new way to alleviate the hepatic fat deposition in aquatic animals.

VEGF Induces Expression of Genes That Either Promote or Limit Relaxation of the Retinal Endothelial Barrier.

The purpose of this study was to identify genes that mediate VEGF-induced permeability. We performed RNA-Seq analysis on primary human retinal endothelial cells (HRECs) cultured in normal (5 mM) and high glucose (30 mM) conditions that were treated with vehicle, VEGF, or VEGF then anti-VEGF. We filtered our RNA-Seq dataset to identify genes with the following four characteristics: (1) regulated by VEGF, (2) VEGF regulation reversed by anti-VEGF, (3) regulated by VEGF in both normal and high glucose conditions, and (4) known contribution to vascular homeostasis. Of the resultant 18 genes, members of the Notch signaling pathway and ANGPT2 (Ang2) were selected for further study. Permeability assays revealed that while the Notch pathway was dispensable for relaxing the barrier, it contributed to maintaining an open barrier. In contrast, Ang2 limited the extent of barrier relaxation in response to VEGF. These findings indicate that VEGF engages distinct sets of genes to induce and sustain barrier relaxation. Furthermore, VEGF induces expression of genes that limit the extent of barrier relaxation. Together, these observations begin to elucidate the elegance of VEGF-mediated transcriptional regulation of permeability.

Transcription factor EB (TFEB) participates in antiviral immune responses independent of mTORC1 in macrophage of large yellow croaker (Larimichthys crocea).

Transcription factor EB (TFEB) plays an integral role in the production of proinflammatory cytokines and chemokines in response to pathogen stimulation in mammals. However, the role of TFEB in antiviral immune responses and the potential regulatory mechanisms in fish remain poorly understood. Here, we cloned and characterized Larimichthys crocea TFEB (LcTFEB) with 524 amino acids and a typical basic helix-loop-helix-leucine zipper domain. LcTFEB could translocate into the nucleus upon starvation and had a comparatively high expression in immune tissues. Similar to the expression of antiviral immune genes, the transcriptional expression and activity of LcTFEB showed a trend of increasing and then decreasing with the prolongation of stimulation. Inhibition of LcTFEB using siRNA dramatically increased the polyinosinic-polycytidylic acid (poly (I:C))-induced interferon response and pro-inflammatory cytokines mRNA expression levels, whereas pharmacological activation and overexpression of LcTFEB exhibited the reverse effects. Mechanically, LcTFEB might promote the expression of IFNh as negative feedback to limit the virus-induced inflammatory responses. Notably, although inhibition of mTORC1 exacerbated poly (I:C)-triggered inflammatory responses, the effects of LcTFEB were independent of mTORC1. Overall, this study revealed an unidentified critical role of LcTFEB in the regulation of antiviral immune responses and promoted the understanding of TFEB in the antiviral immunity of fish macrophages.

Neuroprotective Effect of Stearidonic Acid on Amyloid ß-Induced Neurotoxicity in Rat Hippocampal Cells.

Dietary intake of omega-3 fatty acids found in fish has been reported to reduce the risk of Alzheimer's Disease (AD). Stearidonic acid (SDA), a plant-based omega-3 fatty acid, has been targeted as a potential surrogate for fish-based fatty acids. However, its role in neuronal degeneration is unknown. This study was designed to evaluate effects of SDA on Amyloid-ß(A-ß)-induced neurotoxicity in rat hippocampal cells. Results showed that SDA effectively converted to eicosapentaenoic acid (EPA) in hippocampal cells. Aß-induced apoptosis in H19-7 cells was protected by SDA pretreatment as evidenced by its regulation on the expression of relevant pro- and anti-apoptotic genes, as well as the inhibition on caspase activation. SDA also protected H19-7 cells from Aß-induced oxidative stress by regulating the expression of relevant pro- and anti-oxidative genes, as well as the improvement in activity of catalase. As for Aß/LPS-induced neuronal inflammation, SDA pretreatment reduced the release of IL-1ß and TNFα. Further, we found that the anti-Aß effect of SDA involves its inhibition on the expression of amyloid precursor protein and the regulation on MAPK signaling. These results demonstrated that SDAs have neuroprotective effect in Aß-induced H19-7 hippocampal cells. This beneficial effect of SDA was attributed to its antiapoptotic, antioxidant, and anti-inflammatory properties.

Determination of Cyclaniliprole in Fruits and Vegetables Using Disposable Pipette Extraction Cleanup and Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry.

Despite an outstanding agent for control of Lepidoptera, the diamide insecticide cyclaniliprole (CYCP) is a suspected carcinogen. In the present study, an analytical method was developed for the determination of CYCP in six fruits and vegetables (apple, grape, peach, bell pepper, lettuce, and tomato) using ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry. Sample preparation was carried out by the acetonitrile-salting-out extraction followed by simple and fast cleanup of disposable pipette extraction tip containing styrene divinyl benzene and/or graphitized carbon black. Satisfactory linearity (r > 0.99) was obtained in the calibration range of 0.001−1 µg mL−1. Matrix effects decreased from −9.9−−17.9% to −1.0−−7.6% after the cleanup. The recoveries of CYCP at three spike levels (0.01, 0.1, and 1 mg kg−1) from different matrices were between 75.7% and 111.5%, with the intra-day (n = 5) and inter-day (n = 15) relative standard deviations lower than 12.1%. The limit of quantification was 0.01 mg kg−1. The developed method provides a good reference for routine monitoring of CYCP in these fruits and vegetables.

Hyperglycemia Promotes Mitophagy and Thereby Mitigates Hyperglycemia-Induced Damage.

The observation that diabetic retinopathy (DR) typically takes decades to develop suggests the existence of an endogenous system that protects from diabetes-induced damage. To investigate the existance of such a system, primary human retinal endothelial cells were cultured in either normal glucose (5 mmol/L) or high glucose (30 mmol/L; HG). Prolonged exposure to HG was beneficial instead of detrimental. Although tumor necrosis factor-α-induced expression of vascular cell adhesion molecule 1 and intercellular adhesion molecule 1 was unaffected after 1 day of HG, it waned as the exposure to HG was extended. Similarly, oxidative stress-induced death decreased with prolonged exposure to HG. Furthermore, mitochondrial functionality, which was compromised by 1 day of HG, was improved by 10 days of HG, and this change required increased clearance of damaged mitochondria (mitophagy). Finally, antagonizing mitochondrial dynamics compromised the cells' ability to endure HG: susceptibility to cell death increased, and basal barrier function and responsiveness to vascular endothelial growth factor deteriorated. These observations indicate the existence of an endogenous system that protects human retinal endothelial cells from the deleterious effects of HG. Hyperglycemia-induced mitochondrial adaptation is a plausible contributor to the mechanism responsible for the delayed onset of DR; loss of hyperglycemia-induced mitochondrial adaptation may set the stage for the development of DR.

Zn-Enriched Bacillus cereus Alleviates Cd Toxicity in Mirror Carp (Cyprinus carpio): Intestinal Microbiota, Bioaccumulation, and Oxidative Stress.

Cadmium (Cd) poisoning in humans and fish represents a significant global problem. Bacillus cereus (B. cereus) is a widely used probiotic in aquaculture. The objective of this study was to evaluate the potential of B. cereus in ameliorating Cd-induced toxicity in mirror carp. The biosorption rate of Zn for the B. cereus in 85.99% was significantly more than five strains. All fishes were exposed for 30 days to dietary ZnCl2 (30mg/kg), waterborne Cd (1 mg/L), and/or dietary Zn-enriched B. cereus (Zn 30mg/kg and 107cfu/g B. cereus). At 15 and 30 days, the fishes were sampled, and bioaccumulation, antioxidant activity, and intestinal microbiota were measured. Waterborne Cd exposure caused marked alterations in the composition of the microbiota. Dietary supplementation with Zn-enriched B. cereus can reduce the changes in the composition of intestinal microbiota in Cd exposure and decrease the pathogenic bacteria of Flavobacterium and Pseudomonas in Zn-enriched B. cereus groups. The results obtained indicate that Zn-enriched B. cereus can provide a significant protective effect on the toxicity of cadmium by inhibiting alterations in the levels of bioaccumulation and antioxidant enzyme including superoxide dismutase (SOD), catalase (CAT), total antioxidant (T-AOC), and malonaldehyde (MDA). Our results suggest that administration of Zn-enriched B. cereus has the potential to combat Cd toxicity in mirror carp.

Tissue distribution and seasonal accumulation of carotenoids in Yesso scallop (Mizuhopecten yessoensis) with orange adductor muscle.

Carotenoids are colored compounds with important physiological functions. The Haida golden scallop, which has an orange adductor muscle, is a carotenoid-enriched variety of scallop Mizuhopecten yessoensis, an important aquaculture shellfish. In this study, we investigated the tissue distribution of the carotenoids, pectenolone and pectenoxanthin, in both Haida golden scallop and normal Yesso scallop. Both carotenoids were detected in all the sampled tissues of the two scallops, except in the adductor muscle of normal scallop. There were significantly more carotenoids in Haida golden scallop than in normal scallop, in the tissues of the mantle, female gonad, kidney, and adductor muscle. Increased carotenoid concentrations were detected in Haida golden scallop adductor muscle during the spring spawning season, indicating the effects of reproduction on muscle carotenoids accumulation. This study was the first systematic investigation of carotenoid distribution in Yesso scallop tissues and will benefit future research on carotenoid accumulation and function in scallops.

The Role of the Wnt Pathway in VEGF/Anti-VEGF-Dependent Control of the Endothelial Cell Barrier.

Purpose: Investigate the contribution of the Wnt pathway to vascular endothelial growth factor (VEGF)/anti-VEGF-mediated control of endothelial cell permeability. Methods: High glucose-treated primary human retinal endothelial cells (HRECs) were exposed to either VEGF, or VEGF and then anti-VEGF. Changes in gene expression were assayed by RNAseq and qRT-PCR. Permeability was monitored by electrical cell-substrate impedance sensing (ECIS). Approaches to activate the Wnt pathway included treatment with LiCl and overexpression of constitutively activated ß-catenin. ß-catenin-dependent transcriptional activity was monitored in HRECs stably expressing a TCF/LEF-driven reporter. Results: VEGF/anti-VEGF altered expression of genes encoding many members of the Wnt pathway. A subset of these genes was regulated in a way that is likely to contribute to control of the endothelial cell barrier. Namely, the VEGF-induced alteration of expression of such genes was reversed by anti-VEGF, and such adjustments occurred at times corresponding to changes in barrier function. While pharmacological and molecular approaches to activate the Wnt pathway had no effect on basal permeability, they suppressed VEGF-induced relaxation. Furthermore, anti-VEGF-mediated restoration of barrier function was unaffected by activation of the Wnt pathway. Conclusions: VEGF/anti-VEGF engages multiple members of the Wnt pathway, and activating this pathway enforces the endothelial barrier by attenuating VEGF-induced relaxation. These data suggest that FDA-approved agents such as LiCl may be an adjuvant to anti-VEGF therapy for patients afflicted with blinding conditions including diabetic retinopathy.

Rapid Determination of 21 Chinese Domestically Registered Pesticides in Ginseng Using Cleanup Based on Zirconium-Oxide-Modified Silica and Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry.

In this study, an analytical method was developed for the rapid determination of 21 pesticides used in ginseng cultivation. All pesticides covered by this method have been registered by 2020 in China for use on ginseng. The extracts were cleaned up using zirconium-oxide-modified silica (Z-Sep) and primary secondary amine (PSA). The combination of Z-Sep and PSA provided good recovery for all analytes and the cleanest matrix background out of a number of PSA-based sorbent combinations, as indicated by high-performance liquid chromatography (HPLC) and gas chromatography (GC). Instrumental analysis was completed in 5 min using the ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The linearity (r > 0.99) for all analytes was satisfactory over the calibration range of 0.002-0.1 µg mL-1. Intraday recoveries (n = 5) at ginseng-spiked levels of 0.02, 0.05, 0.1, and 1 mg kg-1 ranged between 72% and 119%, with the corresponding relative standard deviations (RSDs), were less than 19%, while the interday recoveries (n = 15) ranged between 77% and 103%, and RSDs were less than 22%. Limits of quantitation (LOQs) ranged between 0.02 and 0.05 mg kg-1 for all 21 pesticides. This is a seminal study using Z-Sep for the efficient cleanup of ginseng samples, and it could present a practical method for future monitoring of pesticide residues in ginseng produced in China.

Effects of microencapsulated abamectin on the mechanical, cross-linking, and release properties of PBS.

Herein, nanocomposite microencapsulated abamectin (A-G-G) have been prepared by composite coacervation method with gelatin and gum arabic as the wall materials and abamectin (A-W) as core material. The formation mechanism of A-G-G was determined by fourier-transform infrared spectroscopy, scanning electron microscopy, and other characterization methods. Then, polybutylene succinate (PBS)/A-G-G composite films with different contents of A-G-G microcapsules were prepared. The effects of adding A-G-G microcapsules on the mechanical and sustained-release properties of the composite films were studied. Results show that there is a strong interaction between the CO groups in PBS and free OH of the A-G-G microcapsules. With an increase in the A-G-G microcapsule content, the elongation at the break of composite films increases significantly. When the A-G-G content is 15 %, the elongation at break of the composite films reaches 178.6 ±â€¯6.26 %. The maximum water absorption is 329 ±â€¯5.84 %. Overall, the PBS/A-G-G composite films exhibit good slow-release performance.

The Intruding Wolbachia Strain from the Moth Fails to Establish Itself in the Fruit Fly Due to Immune and Exclusion Reactions.

Wolbachia is capable of regulating host reproduction, and thus of great significance in preventing the spread of insect-borne diseases and controlling pest insects. The fruit fly Drosophila melanogaster is an excellent model insect for understanding Wolbachia-host interactions. Here we artificially transferred the wCcep strain from the rice moth Corcyra cephalonica into D. melanogaster by microinjection. Crossing experiments indicated that wCcep could induce a high level of CI in the phylogenetically distant host D. melanogaster and imposed no negative fitness costs on host development and fecundity. Based on quantitative analysis, the titres of wCcep and the native wMel strain were negatively correlated, and wCcep could only be transmitted in the novel host for several generations (G0 to G4) after transinfection. Transcriptome sequencing indicated that the invading wCcep strain induced a significant immune- and stress-related response from the host. An association analysis between the expression of immune genes attacin-D/edin and the titre of Wolbachia by linear regression displayed a negative correlation between them. Our study suggest that the intrusion of wCcep elicited a robust immune response from the host and incurred a competitive exclusion from the native Wolbachia strain, which resulted in the failure of its establishment in D. melanogaster.

The Renin-Angiotensin-Aldosterone System (RAAS) Is One of the Effectors by Which Vascular Endothelial Growth Factor (VEGF)/Anti-VEGF Controls the Endothelial Cell Barrier.

Leakage of retinal blood vessels, which is an essential element of diabetic retinopathy, is driven by chronic elevation of vascular endothelial growth factor (VEGF). VEGF quickly relaxes the endothelial cell barrier by triggering signaling events that post-translationally modify pre-existing components of intercellular junctions. VEGF also changes expression of genes that are known to regulate barrier function. Our goal was to identify effectors by which VEGF and anti-VEGF control the endothelial cell barrier in cells that were chronically exposed to VEGF (hours instead of minutes). The duration of VEGF exposure influenced both barrier relaxation and anti-VEGF-mediated closure. Most VEGF-induced changes in gene expression were not reversed by anti-VEGF. Those that were constitute VEGF effectors that are targets of anti-VEGF. Pursuit of such candidates revealed that VEGF used multiple, nonredundant effectors to relax the barrier in cells that were chronically exposed to VEGF. One such effector was angiotensin-converting enzyme, which is a member of the renin-angiotensin-aldosterone system (RAAS). Pharmacologically antagonizing either the angiotensin-converting enzyme or the receptor for angiotensin II attenuated VEGF-mediated relaxation of the barrier. Finally, activating the RAAS reduced the efficacy of anti-VEGF. These discoveries provide a plausible mechanistic explanation for the long-standing appreciation that RAAS inhibitors are beneficial for patients with diabetic retinopathy and suggest that antagonizing the RAAS improves patients' responsiveness to anti-VEGF.

Residue analysis of fungicides fenpicoxamid, isofetamid, and mandestrobin in cereals using zirconium oxide disposable pipette extraction clean-up and ultrahigh-performance liquid chromatography-tandem mass spectrometry.

In the present study, a fast multiresidue method determining three novel fungicides fenpicoxamid, isofetamid, and mandestrobin in cereals was developed and validated for the first time using ultrahigh-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Samples were extracted by QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) methodology, and cleaned up using the disposable pipette extraction (DPX) tips containing primary secondary amine (PSA) and silica gel modified with zirconium oxide (Z-Sep) in less than 1 min. Linearity (r > 0.99) of three fungicides in the calibration range of 0.001-0.1 µg mL-1 was satisfactory. Mean recoveries (n = 15) from all matrices were between 84.8% and 100.3% as the corresponding intra-day and inter-day relative standard deviations (RSDs) were less than 10.6%. Limits of quantitation (LOQs) of all analytes in different matrices were defined at 0.01 mg kg-1. The results indicate this method can serve as a sensitive and rapid approach to monitoring contents of fenpicoxamid, isofetamid, and mandestrobin in cereals.