Exploring the synergistic effects of indole acetic acid (IAA) and compost in the phytostabilization of nickel (Ni) in cauliflower rhizosphere.

Heavy metals (HMs) contamination, owing to their potential links to various chronic diseases, poses a global threat to agriculture, environment, and human health. Nickel (Ni) is an essential element however, at higher concentration, it is highly phytotoxic, and affects major plant functions. Beneficial roles of plant growth regulators (PGRs) and organic amendments in mitigating the adverse impacts of HM on plant growth has gained the attention of scientific community worldwide. Here, we performed a greenhouse study to investigate the effect of indole-3-acetic acid (IAA @ 10- 5 M) and compost (1% w/w) individually and in combination in sustaining cauliflower growth and yield under Ni stress. In our results, combined application proved significantly better than individual applications in alleviating the adverse effects of Ni on cauliflower as it increased various plant attributes such as plant height (49%), root length (76%), curd height and diameter (68 and 134%), leaf area (75%), transpiration rate (36%), stomatal conductance (104%), water use efficiency (143%), flavonoid and phenolic contents (212 and 133%), soluble sugars and protein contents (202 and 199%), SPAD value (78%), chlorophyll 'a and b' (219 and 208%), carotenoid (335%), and NPK uptake (191, 79 and 92%) as compared to the control. Co-application of IAA and compost reduced Ni-induced electrolyte leakage (64%) and improved the antioxidant activities, including APX (55%), CAT (30%), SOD (43%), POD (55%), while reducing MDA and H2O2 contents (77 and 52%) compared to the control. The combined application also reduced Ni uptake in roots, shoots, and curd by 51, 78 and 72% respectively along with an increased relative production index (78%) as compared to the control. Hence, synergistic application of IAA and compost can mitigate Ni induced adverse impacts on cauliflower growth by immobilizing it in the soil.

Engineered Exosomes with Growth Differentiation Factor-15 Overexpression Enhance Cardiac Repair After Myocardial Injury.

Background: Cardiac repair remains a thorny issue for survivors of acute myocardial infarction (AMI), due to the regenerative inertia of myocardial cells. Cell-free therapies, such as exosome transplantation, have become a potential strategy for myocardial injury. The aim of this study was to investigate the role of engineered exosomes in overexpressing Growth Differentiation Factor-15 (GDF-15) (GDF15-EVs) after myocardial injury, and their molecular mechanisms in cardiac repair. Methods: H9C2 cells were transfected with GDF-15 lentivirus or negative control. The exosomes secreted from H9C2 cells were collected and identified. The cellular apoptosis and autophagy of H2O2-injured H9C2 cells were assessed by Western blotting, TUNEL assay, electron microscopy, CCK-8 and caspase 3/7 assay. A rat model of AMI was constructed by ligating the left anterior descending artery. The anti-apoptotic, pro-angiogenic effects of GDF15-EVs treatment, as well as ensuing functional and histological recovery were evaluated. Then, mRNA sequencing was performed to identify the differentially expressed mRNAs after GDF15-EVs treatment. Results: GDF15-EVs inhibited apoptosis and promoted autophagy in H2O2 injured H9C2 cells. GDF15-EVs effectively decreased the infarct area and enhanced the cardiac function in rats with AMI. Moreover, GDF15-EVs hindered inflammatory cell infiltration, inhibited cell apoptosis, and promoted cardiac angiogenesis in rats with AMI. RNA sequence showed that telomerase reverse transcriptase (TERT) mRNA was upregulated in GDF15-EVs-treated H9C2 cells. AMPK signaling was activated after GDF15-EVs. Silencing TERT impaired the protective effects of GDF15-EVs on H2O2-injured H9C2 cells. Conclusion: GDF15-EVs could fulfil their protective effects against myocardial injury by upregulating the expression of TERT and activating the AMPK signaling pathway. GDF15-EVs might be exploited to design new therapies for AMI.

m6A methyltransferase AflIme4 orchestrates mycelial growth, development and aflatoxin B1 biosynthesis in Aspergillus flavus.

Aflatoxin B1 (AFB1), a highly toxic secondary metabolite produced by Aspergillus flavus, poses a severe threat to agricultural production, food safety and human health. The methylation of mRNA m6A has been identified as a regulator of both the growth and AFB1 production of A. flavus. However, its intracellular occurrence and function needs to be elucidated. Here, we identified and characterized a m6A methyltransferase, AflIme4, in A. flavus. The enzyme was localized in the cytoplasm, and knockout of AflIme4 significantly reduced the methylation modification level of mRNA. Compared with the control strains, ΔAflIme4 exhibited diminished growth, conidial formation, mycelial hydrophobicity, sclerotium yield, pathogenicity and increased sensitivity to CR, SDS, NaCl and H2O2. Notably, AFB1 production was markedly inhibited in the A. flavus ΔAflIme4 strain. RNA-Seq coupled with RT-qPCR validation showed that the transcriptional levels of genes involved in the AFB1 biosynthesis pathway including aflA, aflG, aflH, aflK, aflL, aflO, aflS, aflV and aflY were significantly upregulated. Methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) analysis demonstrated a significant increase in m6A methylation modification levels of these pathway-specific genes, concomitant with a decrease in mRNA stability. These results suggest that AflIme4 attenuates the mRNA stability of genes in AFB1 biosynthesis by enhancing their mRNA m6A methylation modification, leading to impaired AFB1 biosynthesis. Our study identifies a novel m6A methyltransferase AflIme4 and highlights it as a potential target to control A. flavus growth, development and aflatoxin pollution.

Transcriptomics aids in uncovering the metabolic shifts and molecular machinery of Schizochytrium limacinum during biotransformation of hydrophobic substrates to docosahexaenoic acid.

BACKGROUND: Biotransformation of waste oil into value-added nutraceuticals provides a sustainable strategy. Thraustochytrids are heterotrophic marine protists and promising producers of omega (ω) fatty acids. Although the metabolic routes for the assimilation of hydrophilic carbon substrates such as glucose are known for these microbes, the mechanisms employed for the conversion of hydrophobic substrates are not well established. Here, thraustochytrid Schizochytrium limacinum SR21 was investigated for its ability to convert oils (commercial oils with varying fatty acid composition and waste cooking oil) into ω-3 fatty acid; docosahexaenoic acid (DHA). RESULTS: Within 72 h SR21 consumed ~ 90% of the oils resulting in enhanced biomass (7.5 g L- 1) which was 2-fold higher as compared to glucose. Statistical analysis highlights C16 fatty acids as important precursors of DHA biosynthesis. Transcriptomic data indicated the upregulation of multiple lipases, predicted to possess signal peptides for secretory, membrane-anchored and cytoplasmic localization. Additionally, transcripts encoding for mitochondrial and peroxisomal ß-oxidation along with acyl-carnitine transporters were abundant for oil substrates that allowed complete degradation of fatty acids to acetyl CoA. Further, low levels of oxidative biomarkers (H2O2, malondialdehyde) and antioxidants were determined for hydrophobic substrates, suggesting that SR21 efficiently mitigates the metabolic load and diverts the acetyl CoA towards energy generation and DHA accumulation. CONCLUSIONS: The findings of this study contribute to uncovering the route of assimilation of oil substrates by SR21. The thraustochytrid employs an intricate crosstalk among the extracellular and intracellular molecular machinery favoring energy generation. The conversion of hydrophobic substrates to DHA can be further improved using synthetic biology tools, thereby providing a unique platform for the sustainable recycling of waste oil substrates.

AflaILVB/G/I and AflaILVD are involved in mycelial production, aflatoxin biosynthesis, and fungal virulence in Aspergillus flavus.

Aflatoxins (AFs) are produced by fungi such as Aspergillus flavus and A. parasiticus and are one of the most toxic mycotoxins found in agricultural products and food. Aflatoxin contamination, which requires the control of A. flavus, remains problematic because of the lack of effective strategies and the exploration of new compounds that can inhibit A. flavus growth and mycotoxin production is urgently required to alleviate potential deleterious effects. Acetohydroxy acid synthase (AHAS) and dihydroxy acid dehydratase are important enzymes in the biosynthetic pathways of branched-chain amino acids (BCAAs), including isoleucine, leucine, and valine. Enzymes involved in BCAA biosynthesis are present in bacteria, plants, and fungi, but not in mammals, and are therefore, attractive targets for antimicrobial and herbicide development. In this study, we characterized AflaILVB/G/I and AflaILVD, which encode the catalytic and regulatory subunits of AHAS and dihydroxy acid dehydratase, from the pathogenic fungus Aspergillus flavus. The AflaILVB/G/I and AflaILVD deletion mutant grew slower and produced smaller colonies than the wild-type strain when grown on glucose minimal medium, potato dextrose agar, and yeast extract medium for three days at 28°C, and disruption of AflaILVB/G/I caused a significant reduction in conidia production when grown on all kinds of media. Cellular stress assays determined that all strains were sensitive to H2O2. Importantly, the pathogenicity and aflatoxin production were affected when AflaILVB/G/I and AflaILVD were knocked out, particularly AflaILVB/G/I. A series of genes that encoded enzymes involved in aflatoxin synthesis were downregulated, meaning that the knockout of AflaILVB/G/I influenced aflatoxin synthesis in A. flavus strain WT. Collectively, our results demonstrate the potential value of antifungals targeting AflaILVB/G/I in A. flavus.

Comparison of the Backbone Dynamics of Dehaloperoxidase-Hemoglobin Isoenzymes.

Dehaloperoxidase (DHP) is a multifunctional hemeprotein with a functional switch generally regulated by the chemical class of the substrate. Its two isoforms, DHP-A and DHP-B, differ by only five amino acids and have an almost identical protein fold. However, the catalytic efficiency of DHP-B for oxidation by a peroxidase mechanism ranges from 2- to 6-fold greater than that of DHP-A depending on the conditions. X-ray crystallography has shown that many substrates and ligands have nearly identical binding in the two isoenzymes, suggesting that the difference in catalytic efficiency could be due to differences in the conformational dynamics. We compared the backbone dynamics of the DHP isoenzymes at pH 7 through heteronuclear relaxation dynamics at 11.75, 16.45, and 19.97 T in combination with four 300 ns MD simulations. While the overall dynamics of the isoenzymes are similar, there are specific local differences in functional regions of each protein. In DHP-A, Phe35 undergoes a slow chemical exchange between two conformational states likely coupled to a swinging motion of Tyr34. Moreover, Asn37 undergoes fast chemical exchange in DHP-A. Given that Phe35 and Asn37 are adjacent to Tyr34 and Tyr38, it is possible that their dynamics modulate the formation and migration of the active tyrosyl radicals in DHP-A at pH 7. Another significant difference is that both distal and proximal histidines have a 15-18% smaller S2 value in DHP-B, thus their greater flexibility could account for the higher catalytic activity. The distal histidine grants substrate access to the distal pocket. The greater flexibility of the proximal histidine could also accelerate H2O2 activation at the heme Fe by increased coupling of an amino acid charge relay to stabilize the ferryl Fe(IV) oxidation state in a Poulos-Kraut "push-pull"-type peroxidase mechanism.

Cold-stress induced metabolomic and transcriptomic changes in leaves of three mango varieties with different cold tolerance.

BACKGROUND: Mango (Mangifera indica L.) is grown in Hainan, Guangdong, Yunnan, Sichuan, and Fujian provinces and Guanxi autonomous region of China. However, trees growing in these areas suffer severe cold stress during winter, which affects the yield. To this regard, data on global metabolome and transcriptome profiles of leaves are limited. Here, we used combined metabolome and transcriptome analyses of leaves of three mango cultivars with different cold stress tolerance, i.e. Jinhuang (J)-tolerant, Tainung (T) and Guiremang No. 82 (G)-susceptible, after 24 (LF), 48 (MF) and 72 (HF) hours of cold. RESULTS: A total of 1,323 metabolites belonging to 12 compound classes were detected. Of these, amino acids and derivatives, nucleotides and derivatives, and lipids accumulated in higher quantities after cold stress exposure in the three cultivars. Notably, Jinhuang leaves showed increasing accumulation trends of flavonoids, terpenoids, lignans and coumarins, and alkaloids with exposure time. Among the phytohormones, jasmonic acid and abscisic acid levels decreased, while N6-isopentenyladenine increased with cold stress time. Transcriptome analysis led to the identification of 22,526 differentially expressed genes. Many genes enriched in photosynthesis, antenna proteins, flavonoid, terpenoid (di- and sesquiterpenoids) and alkaloid biosynthesis pathways were upregulated in Jihuang leaves. Moreover, expression changes related to phytohormones, MAPK (including calcium and H2O2), and the ICE-CBF-COR signalling cascade indicate involvement of these pathways in cold stress responses. CONCLUSION: Cold stress tolerance in mango leaves is associated with regulation of primary and secondary metabolite biosynthesis pathways. Jasmonic acid, abscisic acid, and cytokinins are potential regulators of cold stress responses in mango leaves.

Vesicle formation-related protein CaSec16 and its ankyrin protein partner CaANK2B jointly enhance salt tolerance in pepper.

Vesicle transport plays important roles in plant tolerance against abiotic stresses. However, the contribution of a vesicle formation related protein CaSec16 (COPII coat assembly protein Sec16-like) in pepper tolerance to salt stress remains unclear. In this study, we report that the expression of CaSec16 was upregulated by salt stress. Compared to the control, the salt tolerance of pepper with CaSec16-silenced was compromised, which was shown by the corresponding phenotypes and physiological indexes, such as the death of growing point, the aggravated leaf wilting, the higher increment of relative electric leakage (REL), the lower content of total chlorophyll, the higher accumulation of dead cells, H2O2, malonaldehyde (MDA), and proline (Pro), and the inhibited induction of marker genes for salt-tolerance and vesicle transport. In contrast, the salt tolerance of pepper was enhanced by the transient overexpression of CaSec16. In addition, heterogeneously induced CaSec16 protein did not enhance the salt tolerance of Escherichia coli, an organism lacking the vesicle transport system. By yeast two-hybrid method, an ankyrin protein, CaANK2B, was identified as the interacting protein of CaSec16. The expression of CaANK2B showed a downward trend during the process of salt stress. Compared with the control, pepper plants with transient-overexpression of CaANK2B displayed increased salt tolerance, whereas those with CaANK2B-silenced exhibited reduced salt tolerance. Taken together, both the vesicle formation related protein CaSec16 and its interaction partner CaANK2B can improve the pepper tolerance to salt stress.

Implications of ZNF334 gene in lymph node metastasis of lung SCC: potential bypassing of cellular senescence.

BACKGROUND: The primary goal of this work is to identify biomarkers associated with lung squamous cell carcinoma and assess their potential for early detection of lymph node metastasis. METHODS: This study investigated gene expression in lymph node metastasis of lung squamous cell carcinoma using data from the Cancer Genome Atlas and R software. Protein-protein interaction networks, hub genes, and enriched pathways were analyzed. ZNF334 and TINAGL1, two less explored genes, were further examined through in vitro, ex vivo, and in vivo experiments to validate the findings from bioinformatics analyses. The role of ZNF334 and TINAGL1 in senescence induction was assessed after H2O2 and UV induced senescence phenotype determined using ß-galactosidase activity and cell cycle status assay. RESULTS: We identified a total of 611 up- and 339 down-regulated lung squamous cell carcinoma lymph node metastasis-associated genes (FDR < 0.05). Pathway enrichment analysis highlighted the central respiratory pathway within mitochondria for the subnet genes and the nuclear DNA-directed RNA polymerases for the hub genes. Significantly down regulation of ZNF334 gene was associated with malignancy lymph node progression and senescence induction has significantly altered ZNF334 expression (with consistency in bioinformatics, in vitro, ex vivo, and in vivo results). Deregulation of TINAGL1 expression with inconsistency in bioinformatics, in vitro (different types of lung squamous cancer cell lines), ex vivo, and in vivo results, was also associated with malignancy lymph node progression and altered in senescence phenotype. CONCLUSIONS: ZNF334 is a highly generalizable gene to lymph node metastasis of lung squamous cell carcinoma and its expression alter certainly under senescence conditions.

Network pharmacology combined with experimental validation to investigate the effect of Rongjin Niantong Fang on chondrocyte apoptosis in knee osteoarthritis.

Knee osteoarthritis (KOA) is a chronic degenerative disease that affects the quality of life of middle­aged and elderly individuals, and is one of the major factors leading to disability. Rongjin Niantong Fang (RJNTF) can alleviate the clinical symptoms of patients with KOA, but the molecular mechanism underlying its beneficial effects on KOA remains unknown. Using pharmacological analysis and in vitro experiments, the active components of RJNTF were analyzed to explore their potential therapeutic targets and mechanisms in KOA. The potential targets and core signaling pathways by which RJNTF exerts its effects on KOA were obtained from databases such as Gene Expression Omnibus, Traditional Chinese Medicine Systems Pharmacology and Analysis Platform. Subsequently, chondrocyte apoptosis was modeled using hydrogen peroxide (H2O2). Cell Counting Kit­8 assay involving a poly [ADP­ribose] polymerase­1 (PARP1) inhibitor, DAPI staining, reverse transcription­quantitative PCR, Annexin V­FITC/PI staining and flow cytometry, western blotting and co­immunoprecipitation analysis were used to determine the therapeutic efficacy of RJNTF on KOA and to uncover the molecular mechanism. It was found that PARP1­knockdown lentivirus, incubation with PARP1 inhibitor PJ34, medium and high doses of RJNTF significantly reduced H2O2­induced chondrocyte apoptosis. Medium and high doses of RJNTF downregulated the expression of cleaved caspase­3, cleaved PARP1 and PAR total proteins, as well as nucleus proteins of apoptosis­inducing factor (AIF) and migration inhibitory factor (MIF), and upregulated the expression of caspase­3, PARP1 total protein, as well as the cytoplasmic expression of AIF and MIF, suggesting that RJNTF may inhibit chondrocyte apoptosis through the PARP1/AIF signaling pathway.

Photocatalytic manipulation of Ca2+ signaling for regulating cellular and animal behaviors via MOF-enabled H2O2 generation.

The in situ generation of H2O2 in cells in response to external stimulation has exceptional advantages in modulating intracellular Ca2+ dynamics, including high controllability and biological safety, but has been rarely explored. Here, we develop photocatalyst-based metal-organic frameworks (DCSA-MOFs) to modulate Ca2+ responses in cells, multicellular spheroids, and organs. By virtue of the efficient photocatalytic oxygen reduction to H2O2 without sacrificial agents, photoexcited DCSA-MOFs can rapidly trigger Ca2+ outflow from the endoplasmic reticulum with single-cell precision in a repeatable and controllable manner, enabling the propagation of intercellular Ca2+ waves (ICW) over long distances in two-dimensional and three-dimensional cell cultures. After photoexcitation, ICWs induced by DCSA-MOFs can activate neural activities in the optical tectum of tadpoles and thighs of spinal frogs, eliciting the corresponding motor behaviors. Our study offers a versatile optical nongenetic modulation technique that enables remote, repeatable, and controlled manipulation of cellular and animal behaviors.

Ultrasonographic Contrast and Therapeutic Effects of Hydrogen Peroxide-Responsive Nanoparticles in a Rat Model with Sciatic Neuritis.

Purpose: Peripheral nerve damage lacks an appropriate diagnosis consistent with the patient's symptoms, despite expensive magnetic resonance imaging or electrodiagnostic assessments, which cause discomfort. Ultrasonography is valuable for diagnosing and treating nerve lesions; however, it is unsuitable for detecting small lesions. Poly(vanillin-oxalate) (PVO) nanoparticles are prepared from vanillin, a phytochemical with antioxidant and anti-inflammatory properties. Previously, PVO nanoparticles were cleaved by H2O2 to release vanillin, exert therapeutic efficacy, and generate CO2 to increase ultrasound contrast. However, the role of PVO nanoparticles in peripheral nerve lesion models is still unknown. Herein, we aimed to determine whether PVO nanoparticles can function as contrast and therapeutic agents for nerve lesions. Methods: To induce sciatic neuritis, rats were administered a perineural injection of carrageenan using a nerve stimulator under ultrasonographic guidance, and PVO nanoparticles were injected perineurally to evaluate ultrasonographic contrast and therapeutic effects. Reverse transcription-quantitative PCR was performed to detect mRNA levels of pro-inflammatory cytokines, ie, tumor necrosis factor-α, interleukin-6, and cyclooxygenase-2. Results: In the rat model of sciatic neuritis, PVO nanoparticles generated CO2 bubbles to increase ultrasonographic contrast, and a single perineural injection of PVO nanoparticles suppressed the expression of tumor necrosis factor-α, interleukin-6, and cyclooxygenase-2, reduced the expression of F4/80, and increased the expression of GAP43. Conclusion: The results of the current study suggest that PVO nanoparticles could be developed as ultrasonographic contrast agents and therapeutic agents for nerve lesions.

Elucidating the modulatory effect of melatonin on enzyme activity and oxidative stress in wheat: a global meta-analysis.

In our comprehensive meta-analysis, we initially collected 177 publications focusing on the impact of melatonin on wheat. After meticulous screening, 40 published studies were selected, encompassing 558 observations for antioxidant enzymes, 312 for reactive oxygen species (ROS), and 92 for soluble biomolecules (soluble sugar and protein). This analysis revealed significant heterogeneity across studies (I2 > 99% for enzymes, ROS, and soluble biomolecules) and notable publication bias, indicating the complexity and variability in the research field. Melatonin application generally increased antioxidant enzyme activities [superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX)] in wheat, particularly under stress conditions, such as high temperature and heavy-metal exposure. Compared to control, melatonin application increased SOD, POD, CAT, and APX activities by 29.5, 16.96, 35.98, and 171.64%, respectively. Moreover, oxidative stress markers like hydrogen peroxide (H2O2), superoxide anion (O2), and malondialdehyde (MDA) decreased with melatonin by 23.73, 13.64, and 21.91%, respectively, suggesting a reduction in oxidative stress. The analysis also highlighted melatonin's role in improving carbohydrate metabolism and antioxidant defenses. Melatonin showed an overall increase of 12.77% in soluble sugar content, and 22.76% in glutathione peroxidase (GPX) activity compared to the control. However, the effects varied across different wheat varieties, environmental conditions, and application methods. Our study also uncovered complex relationships between antioxidant enzyme activities and H2O2 levels, indicating a nuanced regulatory role of melatonin in oxidative stress responses. Our meta-analysis demonstrates the significant role of melatonin in increasing wheat resilience to abiotic stressors, potentially through its regulatory impact on antioxidant defense systems and stress response.

Protective effect and pharmacokinetics of dihydromyricetin nanoparticles on oxidative damage of myocardium.

PURPOSE: This study aims to investigate the protective mechanism of dihydromyricetin PLGA nanoparticles (DMY-PLGA NPs) against myocardial ischemia-reperfusion injury (MIRI) in vitro and the improvement of oral bioavailability in vivo. METHODS: DMY-PLGA NPs was prepared and characterized by emulsifying solvent volatilization, and the oxidative stress model of rat H9c2 cardiomyocyte induced by H2O2 was established. After administration, cell survival rate, lactate dehydrogenase (LDH), malondialdehyde (MDA) and superoxide dismutase (SOD) were detected, and the expressions of PGC1α and PPARα were detected by western blot (WB). At the same time, the pharmacokinetics in rats were studied to explore the improvement of bioavailability. RESULTS: DMY-PLGA NPs can significantly increase cell survival rate, decrease LDH and MDA content, increase SOD content and PGC1α、PPARα protein expression. Compared with DMY, the peak time of DMY-PLGA NPs was extended (P<0.1), and the bioavailability was increased by 2.04 times. CONCLUSION: DMY-PLGA NPs has a significant protective effect on H9c2 cardiomyocytes, which promotes the absorption of DMY and effectively improves bioavailability.

Overexpression of soybean GmDHN9 gene enhances drought resistance of transgenic Arabidopsis.

Soybean is one of the important oil crops and a major source of protein and lipids. Drought can cause severe soybean yields. Dehydrin protein (DHN) is a subfamily of LEA proteins that play an important role in plant responses to abiotic stresses. In this study, the soybean GmDHN9 gene was cloned and induced under a variety of abiotic stresses. Results showed that the GmDHN9 gene response was more pronounced under drought induction. Subcellular localization results indicated that the protein was localized in the cytoplasm. The role of transgenic Arabidopsis plants in drought stress response was further studied. Under drought stress, the germination rate, root length, chlorophyll, proline, relative water content, and antioxidant enzyme content of transgenic Arabidopsis thaliana transgenic genes were higher than those of wild-type plants, and transgenic plants contained less O2-, H2O2 and MDA contents. In short, the GmDHN9 gene can regulate the homeostasis of ROS and enhance the drought resistance of plants.

Resveratrol prevents the release of neutrophil extracellular traps (NETs) by controlling hydrogen peroxide levels and nuclear elastase migration.

Neutrophil extracellular traps (NETs) are defense mechanisms that trap and kill microorganisms and degrade cytokines. However, excessive production, dysregulation of suppression mechanisms, or inefficient removal of NETs can contribute to increased inflammatory response and the development of pathological conditions. Therefore, research has focused on identifying drugs that inhibit or delay the NET release process. Since reactive oxygen species (ROS) play a significant role in NET release, we aimed to investigate whether resveratrol (RSV), with a wide range of biological and pharmacological properties, could modulate NET release in response to different stimuli. Thus, human neutrophils were pretreated with RSV and subsequently stimulated with PMA, LPS, IL-8, or Leishmania. Our findings revealed that RSV reduced the release of NETs in response to all tested stimuli. RSV decreased hydrogen peroxide levels in PMA- and LPS-stimulated neutrophils, inhibited myeloperoxidase activity, and altered the localization of neutrophil elastase. RSV inhibition of NET generation was not mediated through A2A or A2B adenosine receptors or PKA. Based on the observed effectiveness of RSV in inhibiting NET release, our study suggests that this flavonoid holds potential as a candidate for treating NETs involving pathologies.

Physiological and oxidative stress response of carrot (Daucus carota L.) to jumping plant-louse Bactericera trigonica Hodkinson (Hemiptera: Psylloidea) infestation.

BACKGROUND: Carrot is an important vegetable crop grown worldwide. The major economic problem in carrot cultivation is yellow disease caused by Bactericera trigonica, which induces biotic stress and has the greatest impact on crop productivity. Comprehensive studies on the mechanism of carrot defense response to biotic stress caused by B. trigonica infestation have yet to be conducted. METHODS: The changes in photosynthetic pigments, proline, TPC, H2O2 and MDA content, DPPH radical scavenging ability, and antioxidant enzyme activity of SOD, CAT, and POX in carrot leaves in response to insect sex (female and male), rapid response (during the first six hours), and long-term response to B. trigonica infestation were evaluated. RESULTS: The results of our study strongly suggest that B. trigonica infestation causes significant changes in primary and secondary metabolism and oxidative status of carrot leaves. Photosynthetic pigment content, TPC, and DPPH and CAT activities were significantly reduced in carrot leaves in response to insect infestation. On the other hand, proline, H2O2 content, and the activity of the antioxidant enzymes superoxide dismutase and peroxidase were increased in carrot leaves after B. trigonica infestation. The results indicate that B. trigonica attenuates and delays the oxidative stress responses of carrot, allowing long-term feeding without visible changes in the plant. Carrot responded to long-term B. trigonica infestation with an increase in SOD and POX activity, suggesting that these enzymes may play a key role in plant defense mechanisms. CONCLUSIONS: This is the first comprehensive study strongly suggesting that B. trigonica infestation causes significant changes in primary and secondary metabolism and an attenuated ROS defense response in carrot leaves that enables long-term insect feeding. The information provides new insights into the mechanisms of carrot protection against B. trigonica infestation.

CncC-Keap1-P450s pathway is involved in the detoxification of emamectin benzoate in the spongy moth Lymantria dispar.

The detoxification of insecticides in insects is dependent on the expression and activity of multiple detoxification enzymes. As an important modulator of detoxification enzymes, the CncC-Keap1 pathway was involved in the detoxification of various pesticides. However, whether the CncC-Keap1 pathway is involved in the detoxification of emamectin benzoate (EMB) is unclear. In this study, we cloned the LdCncC and LdKeap1 from spongy moths (Lymantria dispar). Our results showed that EMB exposure induced oxidative stress, and activated the CncC-Keap1 pathway at mRNA and protein levels. Removing ROS by N-acetylcysteine remarkably decreased H2O2 levels and restored the expression of LdCncC and LdKeap1. The silencing LdCncC, not LdKeap1, by dsRNA significantly decreased the cytochrome P450 activities, and increased the sensitivity of larvae to EMB. Besides, the expression of CYP6B7v1, CYP321A7 and CYP4S4v1 were significantly decreased after silencing LdCncC. Notably, the knockdown of CYP6B7v1, CYP321A7 or CYP4S4v1 significantly increased the mortality induced by EMB exposure. Therefore, we proposed that activation of CncC-Keap1 pathway induced by ROS increased the detoxification of EMB in spongy moths by regulating the expression of CYP6B7v1, CYP321A7 and CYP4S4v1. Our study strengthened the understanding of the detoxification of EMB from the perspective of CncC-Keap1-P450s pathway.

Ginseng Oligopeptides Improve the Intestinal Physiology and Promote the Antioxidant Capacity of the Gut-on-a-Chip Model.

During ageing, the permeability of the intestinal barrier increases, the integrity of the intestinal barrier decreases, and the physiology of intestinal cells changes. Furthermore, intestinal inflammation and excessive oxidative stress are both likely to cause systemic diseases. Ginseng oligopeptides have a positive significant effect in terms of improving human health and delaying ageing, but their role in the ageing of the intestine has not been studied much. In our experiment, we constructed a gut-on-a-chip model and induced senescence of the chip with H2O2 so as to explore the effects of ginseng oligopeptides on the senescent intestine. The experimental results showed that ginseng oligopeptides had no obvious effects on the integrity of the intestine, including the TEER value and the expression of tight junction proteins. However, ginseng oligopeptides might have other positive effects, such as inhibiting excessive cell proliferation, promoting mucin secretion, and increasing the antioxidant capacity of the intestine, to improve intestinal health.

Glutathione Supplementation Prevents Neonatal Parenteral Nutrition-Induced Short- and Long-Term Epigenetic and Transcriptional Disruptions of Hepatic H2O2 Metabolism in Guinea Pigs.

The parenteral nutrition (PN) received by premature newborns is contaminated with peroxides that induce global DNA hypermethylation via oxidative stress. Exposure to peroxides could be an important factor in the induction of chronic diseases such as those observed in adults who were born preterm. As endogenous H2O2 is a major regulator of glucose-lipid metabolism, our hypothesis was that early exposure to PN induces permanent epigenetic changes in H2O2 metabolism. Three-day-old guinea pigs were fed orally (ON), PN or glutathione-enriched PN (PN+GSSG). GSSG promotes endogenous peroxide detoxification. After 4 days, half the animals were sacrificed, and the other half were fed ON until 16 weeks of age. The liver was harvested. DNA methylation and mRNA levels were determined for the SOD2, GPx1, GCLC, GSase, Nrf2 and Keap1 genes. PN induced GPx1 hypermethylation and decreased GPx1, GCLC and GSase mRNA. These findings were not observed in PN+GSSG. PN+GSSG induced Nrf2 hypomethylation and increased Nrf2 and SOD2 mRNA. These observations were independent of age. In conclusion, in neonatal guinea pigs, PN induces epigenetic changes, affecting the expression of H2O2 metabolism genes. These changes persist for at least 15 weeks after PN. This disruption may signify a permanent reduction in the capacity to detoxify peroxides.