Potential Toxic Mechanisms of Neonicotinoid Insecticides in Rice: Inhibiting Auxin-Mediated Signal Transduction

Interaction between polycyclic aromatic hydrocarbons and thymine (T)-base induces double-strand DNA distortion in different species

Polycyclic aromatic hydrocarbons (PAHs) are potent inhibitors of DNA that can induce genetic damage, abnormal gene expression, and metabolic disorders upon interfacing with biological macromolecules. However, the mechanism of their interactions with DNA remains elusive. Therefore, this study selected three representative PAHs, including phenanthrene (Phen), pyrene (Pyre), and benzo[a]pyrene (B[a]P), and explored their binding mechanisms with the double-strand DNA (dsDNA) from different species, including 1J1V (Escherichia coli), 6J5B (Arabidopsis thaliana), and 6Q1V (Homo sapiens). The results revealed that binding between PAHs and dsDNA occurred in the groove via van der Waals forces and π-π stacking, with the carboxyl oxygen atom of the thymine (T)-base within dsDNA being the key binding site. This result was further confirmed by the spectroscopic experiments, where significant changes in the peak of the T-base were observed after PAHs-dsDNA binding. More interestingly, the total binding energies of Pyre with the three dsDNA were -138.800 kJ/mol (Pyre-1J1V), -105.523 kJ/mol (Pyre-6J5B), and -127.567 kJ/mol (Pyre-6Q1V), respectively, all of which were higher than those of Phen and B[a]P. This suggests that that Pyre has the strongest dsDNA binding ability. Additionally, analysis of the thermodynamic parameters indicated that the interactions between the three PAHs and dsDNA were exothermic reactions. In contrast, the Pyre-dsDNA interaction predominantly involved van der Waals forces and hydrogen bonding due to the enthalpy change (∆H) < 0 and entropy change (∆S) < 0, while the Phen-dsDNA and B[a]P-dsDNA interactions predominantly involved hydrophobic forces due to ∆H > 0 and ∆S > 0. Furthermore, Pyre caused local distortion of dsDNA, which was more pronounced under atomic force microscopy (AFM). In summary, this study has unveiled a new phenomenon of binding between PAHs and dsDNA. This sheds light on the carcinogenic potential and environmental impacts of PAHs pollution.

Polybrominated diphenyl ethers and polychlorinated biphenyls induced rice "diabetes" by disturbing the transport and decomposition of soluble sugars

Halogenated flame retardants in farmlands were observed to inhibit the growth of exposed crops. This study aimed to elucidate the mechanism of inhibition on rice by employing four representative polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). The exposure to these contaminants at 200 nM led to a decrease of 0.63-0.95 fold in rice below-ground biomass and 0.49-0.66 fold in yield, and a corresponding 4%-10% increase in soluble sugars in leaves. PBDEs and PCBs were found to significantly disrupt the synthesis, decomposition, and transport of sugars in leaves, the three pivotal determinants of crop growth. Notably, these compounds promoted a 1.41- to 7.60-fold upregulation of the triose phosphate translocator, significantly enhancing soluble sugar synthesis. Conversely, a 0.45-0.97 fold downregulation was observed for sucrose transporters, thus impeding the leaf-to-shoot efflux of soluble sugars. Furthermore, PBDEs and PCBs were favorably bound to fructose-1,6-bisphosphate aldolase (FBA), inducing its substrate-specific dysfunction in fructose-1,6-diphosphate decomposition (3%-14%). Overall, PBDE and PCB exposure promoted a notable intracellular accumulation of soluble sugars in rice leaves, a typical symptom of plant diabetes, since the intensified synthesis of soluble sugars in leaves and the repressed decomposition and transportation of soluble sugars to other storage organs, thus impeding crop growth. This study provided an insightful understanding of the toxic effects and molecular mechanisms of halogenated flame retardants, highlighting their role in abnormal sugar accumulation and growth inhibition in crops and offering vital information for the risk assessment and administration of these compounds to guarantee the safety of agricultural products.

Screening of specific binding peptide for β-lactoglobulin using phage display technology

β-lactoglobulin (β-Lg) is a major food allergen, there is an urgent need to develop a rapid method for detecting β-Lg in order to avoid contact or ingestion by allergic patients. Peptide aptamers have high affinity, specificity, and stability, and have broad prospects in the field of rapid detection. Using β-Lg as the target, this study screened 11 peptides (P1-11) from a phage display library. Using molecular docking technology to predict binding energy and binding mode of proteins and peptides. Select the peptides with the best binding ability to β-Lg (P5, P7, P8) through ELISA. Combining them with whey protein, casein, and bovine serum protein, it was found that P7 has the best specificity for β-Lg, with an inhibition rate of 87.99%. Verified by molecular dynamics that P7 binds well with β-Lg. Therefore, this peptide can be used for the recognition of β-Lg, becoming a new recognition element for detecting β-Lg.

Agricultural film-derived microplastics elevate the potential risk of pesticides in soil ecosystem: The inhibited leaching by altering soil pore

The residue of mulch film is a crucial source of microplastics (MPs) in agricultural fields. The effects of mulch film-derived MPs on the environmental behavior of pesticides in agriculture remain unclear. In the present study, the effects of MPs of different sizes (5 mm, 1 mm, 30 µm, and 0.3 µm) at environmentally relevant concentrations on pesticide transport were evaluated, and the mechanism was explored with respect to adsorption and pore structure using fluorescence visualization, the extended Derjaguin-Landau-Verwey-Overbeek model, and microcomputed tomography. MPs were found to be retained in the soil due to size limitation, pore capture, and surface adhesion. The presence of mm-sized MPs (5 and 1 mm) at a concentration of 0.25 % inhibited the leaching behavior of atrazine, metolachlor, and tebuconazole. MPs did not significantly alter the pesticide adsorption ability of the soil. The reduced leaching originated from the impact of MPs on soil pore structure. Specifically, the porosity increased by 16.2-25.0 %, and the connectivity decreased by 34.5 %. These results demonstrate that mm-sized MPs inhibit pesticide leaching by obstructing the pores and altering the transport pathways, thereby potentially elevating environmental risks, particularly to the soil ecosystem.

Integrating genomics, molecular docking, and protein expression to explore new perspectives on polystyrene biodegradation

Faced with the escalating challenge of global plastic pollution, this study specifically addresses the research gap in the biodegradation of polystyrene (PS). A PS-degrading bacterial strain was isolated from the gut of Tenebrio molitor, and genomics, molecular docking, and proteomics were employed to thoroughly investigate the biodegradation mechanisms of Pseudomonas putida H-01 against PS. Using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (ATR-FTIR), and contact angle analysis, significant morphological and structural changes in the PS films under the influence of the H-01 strain were observed. The study revealed several potential degradation genes and ten enzymes that were specifically upregulated in the PS degradation environment. Additionally, a novel protein with laccase-like activity, LacQ1, was purified from this strain for the first time, and its crucial role in the PS degradation process was confirmed. Through molecular docking and molecular dynamics (MD) simulations, the interactions between the enzymes and PS were detailed, elucidating the binding and catalytic mechanisms of the degradative enzymes with the substrate. These findings have deepened our understanding of PS degradation.

Understanding the phytotoxic effects of organic contaminants on rice through predictive modeling with molecular descriptors: A data-driven analysis

The widespread introduction of organic compounds into environments poses significant risks to ecosystems. Assessing the adverse effects of organic contaminants on crops is crucial for ensuring food safety. However, laboratory research is often time-consuming and costly, and machine learning (ML) methods can offer a viable solution to address these challenges. This study aimed at developing a ML model that incorporates chemical descriptors to predict the phytotoxicity of organic contaminants on rice. A dataset was compiled by gathering published experimental data on the phytotoxicity of 60 organic compounds, with a focus on morphological inhibition, photosynthesis perturbation, and oxidative stress. Four ML models (RF, SVM, GBM, ANN) were developed using chemical molecular descriptors (CMD) and the Molecular ACCess System (MACCS) keys. RF-MACCS model demonstrated the highest fitness, achieving an R2 value of 0.79 and an RMSE of 0.14. Feature importance analysis highlighted nAtom, HBA, logKow, and TPSA as the most influential CMDs in our model. Additionally, substructures containing oxygen atoms, carbonyl group and carbon chains with nitrogen and oxygen atoms were identified as significant factors associated with phytotoxicity. This data-driven study could aid in predicting the phytotoxicity of organic contaminants on crops and evaluating the potential risks of emerging contaminants in agroecosystems.

The chelation mechanism of neonicotinoid insecticides influencing cadmium transport and accumulation in rice at different growth stage

The combined exposure of heavy metals and organic contaminates can influence the transport and accumulation of heavy metals within the soil-rice system. However, the underlying mechanisms of this process remain largely unknown. Herein, this study investigated the influence of three neonicotinoid insecticides (NIs), including imidacloprid (IMI), clothianidin (CLO), and thiamethoxam (THI), on the Cd transport and accumulation in rice (Oryza sativa) at different growth stages. Particular focus lied on their complex interaction and key genes expression involved in Cd transport. Results showed that the interaction between Cd and NIs was the dominant factor affecting Cd transport and accumulation in rice exposed to NIs. All three NIs chelated with Cd with nitrogen (N) on the IMI and THI nitro groups, and the N on the CLO nitro guanidine group. Interestingly, this chelation behavior varied between the tillering stage and the filling/ripening stages, resulting in diverse patterns of Cd accumulation in rice tissues. During the tillering stage, all three NIs considerably inhibited Cd bioavailability and transport to the above-ground part, lowering Cd content in the stem and leaf. The inhibition was increased with stronger chelation ability in the order of IMI (-0.46 eV) > CLO (-0.41 eV) > THI (-0.11 eV), with IMI exhibiting the highest binding energy for Cd and reducing Cd transfers from root to stem by an impressive 94.49 % during the tillering stage. Conversely, during the filling/ripening stages, NIs facilitated Cd accumulation in rice roots, stems, leaves, and grains. This was mainly attributed to the generation of nitrate ions and the release of Cd2+ during the chelation between Cd and NIs under drainage condition. These findings provide theoretical basis for the treatment of combined contamination in field and deep insights into understanding the interaction of organic contaminants with heavy metals in rice culture process.

Polybrominated diphenyl ethers (PBDEs) decreased the protein quality of rice grains by disturbing amino acid metabolism

Polybrominated diphenyl ethers (PBDEs) in soils posed potential risks to crop growth and food safety due to their prevalence and persistence. PBDEs were capable of being absorbed and accumulated into crops, impacting their growth, whereas the interference on metabolic components and nutritional composition deserves further elucidation. This study integrated a combined non-targeted and targeted metabolomics method to explore the influences of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) and decabromodiphenyl ether (BDE-209) on the metabolic responses of rice (Oryza sativa). Metabolic pathways, which were associated with sugars, organic acids, and amino acids, were significantly disturbed under PBDE stresses. Particularly, 75% of the marked altered pathways belonged to amino acid metabolism, with alanine/aspartate/glutamate metabolism being commonly enhanced. The degradation of aspartic acid promoted the formation of downstream amino acids, among which the levels of lysine, methionine, isoleucine, and asparagine were increased by 1.31-3.15 folds compared to the control. Thus, the antioxidant capacity in rice plants was enhanced, particularly through the significant promotion of ascorbic acid-glutathione (AsA-GSH) cycle in rice leaves. The amino acids were promoted to resist reactive oxygen species (ROS) efficiently, thus were deficient for nutrient storage. When exposed to 4 μmol/kg PBDEs, the contents of amino acids and proteins in grains decreased by 9.1-32.1% and 8.6-34.8%, respectively. In particular, glutelin level was decreased by 5.6-41.2%, resulting in a decline in nutritional quality. This study demonstrated that PBDEs deteriorated the protein nutrition in rice grains by affecting amino acid metabolism, providing a new perspective for evaluating the ecological risks of PBDEs and securing agricultural products.

Molecular mechanism of dissolvable metal nanoparticles-enhanced CO2 fixation by algae: Metal-chlorophyll synthesis

Algae-driven photosynthetic CO2 fixation is a promising strategy to mitigate global climate changes and energy crises. Yet, the presence of metal nanoparticles (NPs), particularly dissolvable NPs, in aquatic ecosystems introduces new complexities due to their tendency to release metal ions that may perturb metabolic processes related to algal CO2 fixation. This study selected six representative metal NPs (Fe3O4, ZnO, CuO, NiO, MgO, and Ag) to investigate their impacts on CO2 fixation by algae (Chlorella vulgaris). We discovered an intriguing phenomenon that bivalent metal ions released from the metal NPs, especially from ZnO NPs, substituted Mg2+ within the porphyrin ring. This interaction led to 81.8% and 76.1% increases in Zinc-chlorophyll and Magnesium-chlorophyll contents within algal cells at 0.01 mM ZnO NPs, respectively. Integrating metabolomics and transcriptomics analyses revealed that ZnO NPs mainly promoted the photosynthesis-antenna protein pathway, porphyrin and chlorophyll metabolism, and carbon fixation pathway, thereby mitigating the adverse effects of Zn2+ substitution in light harvesting and energy transfer for CO2 fixation. Ultimately, the genes encoding Rubisco large subunit (rbcL) responsible for CO2 fixation were upregulated to 2.60-fold, resulting in a 76.3% increase in carbon fixation capacity. Similar upregulations of rbcL expression (1.13-fold) and carbon fixation capacity (76.1%) were observed in algal cells even at 0.001 mM ZnO NPs, accompanied by valuable lipid accumulation. This study offers novel insights into the molecular mechanism underlying NPs on CO2 fixation by algae and potentially introduces strategies for global carbon sequestration.

Transcriptomic and metabolomic analysis provides insight into imazethapyr toxicity to non-target plants

Imazethapyr is a widely used imidazolinone herbicide worldwide, and its potential adverse effects on non-target plants have raised concerns. Understanding the mechanisms of imazethapyr phytotoxicity is crucial for its agro-ecological risk assessment. Here, the comprehensive molecular responses and metabolic alterations of Arabidopsis in response to imazethapyr were investigated. Our results showed that root exposure to imazethapyr inhibited shoot growth, reduced chlorophyll contents, induced photoinhibition and decreased photosynthetic activity. By non-target metabolomic analysis, we identified 75 metabolites that were significantly changed after imazethapyr exposure, and they are mainly enriched in carbohydrate, lipid and amino acid metabolism. Transcriptomic analysis confirmed that imazethapyr significantly downregulated the genes involved in photosynthetic electron transport and the carbon cycle. In detail, 48 genes in the photosynthetic lightreaction and 11 genes in Calvin cycle were downregulated. Additionally, the downregulation of genes related to electron transport in mitochondria provides strong evidence for imazethapyr inhibiting photosynthetic carbon fixation and cellular energy metabolism as one of mechanisms of toxicity. These results revealed the molecular and metabolic basis of imazethapyr toxicity on non-target plants, contributing to environmental risk assessment and mitigate negative impact of imazethapyr residues in agricultural soils.

Imidacloprid triggered changes in strawberry fruits on edible quality and phenolic profiles by applied at two growth stages

Increasing evidence showed that imidacloprid affects plants' abiotic or biotic stress tolerance. However, the effects of imidacloprid on the quality of fruits remain elusive. This work aimed to study the effects of imidacloprid applied at different growth stages on the edible quality and phenolic profile of strawberry fruit in the field experiment. For the first time, lower fruit quality was observed in the mature strawberry fruits after imidacloprid treatment at the fruit-bearing completion stage (five days after pollination). Compared to the control group, the mature strawberry fruit wights and the SCC/TA ratio declined about 18.2-30.0 % and 10.3-16.8 %, respectively. However, those attributes did not occur in the mature strawberry fruits by imidacloprid treatment at the fruit maturation stage (30 days after pollination). Among the 30 phenolic compounds, nine presented significant up-regulation or down-regulation after imidacloprid application at two different growth stages, suggesting that the application period played an essential role in evaluating the effects of imidacloprid on the quality of fruits. A significant effect on fruit quality was presented at the strawberry early growth stage treated by imidacloprid. This study provided a new insight into how and when imidacloprid affects the quality of strawberry fruits, contributing to the future's more scientific application of imidacloprid on strawberries.

The development of prognostic gene markers associated with disulfidptosis in gastric cancer and their application in predicting drug response

Background

Gastric cancer (GC) is a malignancy known for its high fatality rate. Disulfidptosis, a potentially innovative therapeutic strategy for cancer treatment, has been proposed. Nevertheless, the specific involvement of disulfidptosis in the context of GC remains uncertain.

Methods

The mRNA expression profiles were obtained from the TCGA and GEO databases. Univariate and LASSO Cox regression analyses were employed to identify differentially expressed genes and develop a risk model for disulfidptosis-related genes. The performance of the model was evaluated using Kaplan-Meier curve, ROC curve, and nomogram. Univariate and multivariate Cox regression analyses were conducted to determine if the risk model could serve as an independent prognostic factor. The biological function of the identified genes was assessed through GO, KEGG, and GSEA analyses. The prediction of drug response was conducted employing the package "pRRophetic". Furthermore, gene expression was determined using qRT-PCR.

Results

An eight-gene signature were identified and utilized to categorize patients into low- and high-risk groups. Survival, receiver operating characteristic (ROC) curve, and Cox analyses provided clarification that these eight hub genes served as a favorable independent prognostic factor for patients with GC. A nomogram was constructed by integrating clinical parameters with the risk signatures, demonstrating high precision in predicting 1-, 3-, and 5-year survival rates. Additionally, drug sensitivity was different in the high-risk and low-risk groups, and the expression of three genes was verified by qRT-PCR.

Conclusion

The prognostic risk model developed in this study demonstrates the potential to accurately forecast the prognosis of patients with GC.

Tolerance mechanism of rice (Oryza sativa L.) seedings towards polycyclic aromatic hydrocarbons toxicity: The activation of SPX-mediated signal transduction to maintain P homeostasis

Plant tolerance to abiotic stress depends on fast molecular cascades involving stress perception, signal transduction, gene expression alterations, and metabolic rearrangement. This study sheds light on the tolerance mechanism of rice (Oryza sativa L.) towards the toxicity of the polycyclic aromatic hydrocarbons (PAHs), including phenanthrene (Phe), pyrene (Pyr), and benzo[a]pyrene (BaP). Results showed that three PAHs significantly activated the phosphoinositide signaling system involving the phosphorus (P) metabolism and homeostasis in rice roots. This activation increased phytic acid (IP6) levels to over 54.12% of the control (p < 0.05). Molecular docking verified that three PAHs occupied the IP6 binding site in SPX3, a negative regulatory factor of P homeostasis, where ARG229 interacted with PAHs via the van der Waals force. Moreover, the expression of gene encoding SPX3 was significantly downregulated 2.81-, 2.83-, and 2.18-fold under Phe, Pyr, and BaP stress, respectively, relative to the control. Conversely, the expression levels of the gene coding SDEL2 was significantly increased, promoting the degradation of SPX3. Ultimately, P absorption and nucleic acid synthesis were enhanced, alleviating the inhibition effect of PAHs on rice growth. Notably, Pyr demonstrated the strongest binding affinity for SPX3, confirming its critical interference with P homeostasis. These findings provide insight into the molecular mechanisms regulating plant responses to PAHs, and offer guidance for improving crop resistance against organic pollutants and protecting food security.

Internalization, physiological responses and molecular mechanisms of lettuce to polystyrene microplastics of different sizes: Validation of simulated soilless culture

Microplastics (MPs) exists widely in the environment, and the resulting pollution of MPs has become a global environmental problem. Plants can absorb MPs through their roots. However, studies on the mechanism of the effect of root exposure to different size MPs on vegetables are limited. Here, we use Polystyrene (PS) MPs with different particle sizes to investigate the internalization, physiological response and molecular mechanism of lettuce to MPs. MPs may accumulate in large amounts in lettuce roots and migrate to the aboveground part through the vascular bundle, while small particle size MPs (SMPs, 100 nm) have stronger translocation ability than large particle size MPs (LMPs, 500 nm). MPs can cause physiological and biochemical responses and transcriptome changes in lettuce. SMPs and LMPs resulted in reduced biomass (38.27 % and 48.22 % reduction in fresh weight); caused oxidative stress (59.33 % and 47.74 % upregulation of SOD activity in roots) and differential gene expression (605 and 907 DEGs). Signal transduction, membrane transport and alteration of synthetic and metabolic pathways may be the main causes of physiological toxicity of lettuce. Our study provides important information for understanding the behavior and fate of MPs in edible vegetables, especially the physiological toxicity of MPs to edible vegetables, in order to assess the potential threat of MPs to food safety and agricultural sustainable development.

Root extract of Hemsleya amabilis Diels suppresses renal cell carcinoma cell growth through inducing apoptosis and G2/M phase arrest via PI3K/AKT signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Hemsleya amabilis Diels, belongs to cucurbitaceae, was traditional Chinese medicine (TCM). It is widely used to treat various diseases. However, these diseases may contribute to the development of RCC.

AIM OF THE STUDY

investigated the anticancer activities of root extract of Hemsleya amabilis Diels (HRE), and elucidated the underlying molecular mechanism in vivo and in vitro.

MATERIALS AND METHODS

Dried Hemsleya amabilis Diels roots were extracted by ethyl acetate and used to treat RCC4, OS-RC-2 and ACHN cells. UHPLC-MS was used to analyze the chemical composition of the extract. CCK-8 and colony formation assay were used to investigate proliferation. PI staining was used to detect cell cycle. Annexin-V-FITC, AO/EB and TEM were used to evaluate apoptosis. Transwell and wound healing assays were used to evaluate migration and invasion. RNA-seq, Network pharmacology, autodocking for virtual screening and molecular dynamics simulation were used to analyze potential molecular mechanisms and active components of HRE inhibiting proliferation of RCC. LY294002 and UC2288 were used to inhibit PI3K and P21 expression, respectively. IGF-1 was used to activate PI3K. Xenograft tumor model was established to evaluate its anti-tumor potential in vivo. Immunohistochemistry and Western blot were used to test protein expression levels. H&E staining was used to explore the side effects of HRE in vivo. Applying bioinformatics to analyze the effect of P21 on RCC.

RESULTS

HRE consists of 739 compounds. CCK-8 and colony formation assay showed that HRE significantly inhibited RCC cells proliferation. PI staining indicated that HRE caused G2/M phase arrest. Annexin-V-FITC, AO/EB and TEM experiments revealed that HRE significantly promoted apoptosis of RCC cells. Transwell and wound healing assays showed that HRE can inhibit the migration and invasion of RCC cells. RNA-seq showed that HRE induced 230 gene changes. Network pharmacology analysis found the relationship between HRE-component-target-RCC. Auto-docking found that Epitulipinolide diepoxide in HRE can stably bind to PIK3CA (-7.22 kJ/mol), and molecular dynamics simulation verified the combination between Epitulipinolide diepoxide of PIK3CA. In RCC4 cells, pretreatment with IGF-1, attenuated HRE-induced apoptosis and G2/M arrest. When pretreated with PIK3 inhibitor LY294002, the opposite result appears. Pretreatment with CDKN1A (P21) inhibitor UC2288 attenuated HRE-induced G2/M arrest. Xenograft tumor model showed that HRE inhibited tumor growth. Western blot analysis indicated that HRE can regulating Bax, Bcl-2, PARP, cleared-PARP, Caspase-9, Caspase-8, Caspase-3, Survivin, Cyclin-B1, CDK1, N-cadherin, snail, slug, E-cadherin, MMP-9. Immunohistochemical staining showed that in the treated group, expression of E-cadherin, Bax, P21 was up-regulated, while N-cadherin, PI3K, AKT and Bcl-2 were down-regulated. H&E staining showed that compared to control groups, the main organs in the HRE-treated groups showed no histological abnormalities. The overall survival rate of RCC patients in the high-expression group of P21 was higher than in the low-expression group of P21 on bioinformatics analysis.

CONCLUSIONS

HRE inhibited RCC migration and invasion through EMT, and inhibited proliferation in vivo and in vitro. In addition, HRE inhibited proliferation through promoting apoptosis and P21-induced G2/M phase arrest via PI3K/AKT signaling pathway. Overall, these results suggest that HRE may be a promising chemotherapy agent for RCC.

Exploring an Efficient and Eco-Friendly Signaling Molecule and Its Quorum Quenching Ability for Controlling Microcystis Blooms

Globally, cyanobacterial blooms have become serious problems in eutrophic water. Most previous studies have focused on environmental factors but have neglected the role of quorum sensing (QS) in bloom development and control. This study explored a key quorum sensing molecule (QSM) that promotes cell growth and then proposed a targeted quorum quencher to control blooms. A new QSM 3-OH-C4-HSL was identified with high-resolution mass spectrometry. It was found to regulate cellular carbon metabolism and energy metabolism as a means to promote Microcystis aeruginosa growth. To quench the QS induced by 3-OH-C4-HSL, three furanone-like inhibitors were proposed based on molecular structure, of which dihydro-3-amino-2-(3H)-furanone (FN) at a concentration of 20 μM exhibited excellent inhibition of M. aeruginosa growth (by 67%). Molecular docking analysis revealed that the inhibitor strongly occupied the QSM receptor protein LuxR by binding with Asn164(A) and His167(A) via two hydrogen bonds (the bond lengths were 3.04 and 4.04 Å) and the binding energy was -5.9 kcal/mol. The inhibitor blocked signaling regulation and induced programmed cell death in Microcystis. Importantly, FN presented little aquatic biotoxicity and negligibly affected aquatic microbial function. This study provides a promising new and eco-friendly strategy for controlling cyanobacterial blooms.

α-Galactosidase interacts with persistent organic pollutants to induce oxidative stresses in rice (Oryza sativa L.)

Persistent organic pollutants (POPs) in agricultural soil often triggered metabolic alterations and phytotoxicity in plants, ultimately threatening crop quality. Unraveling the phytotoxic mechanisms of POPs in crops is critical for evaluating their environmental risks. Herein, the molecular mechanism of POP-induced phytotoxicity in rice (Oryza sativa L.) was analyzed using metabolic profile, enzyme activity, and gene expression as linkages, including polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers, polychlorinated biphenyls, and phthalate esters. Despite no observable changes in phenotypic traits (e.g., biomass and length of aboveground), the levels of reactive oxygen species (ROS) were promoted under stresses of the tested POPs, particularly 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP). Metabolomics analysis revealed that ROS contents positively correlated with metabolic perturbation levels (r = 0.83), among which the galactose metabolism was significantly inhibited when exposed to DBP, DEHP, or BDE-47. The α-Galactosidase (α-Gal) involved in galactose metabolism was targeted as the key enzyme for the phytotoxicity of DBP, DEHP, and BDE-47, which was revealed by the inhibition of saccharide levels (45.5-82.1%), the catalytic activity of α-Gal (18.5-24.3%), and the gene expression (28.5-34.5%). Molecular docking simulation suggested that the three POPs occupied the active sites of α-Gal and formed a stable protein-ligand complex, thus inhibiting the catalytic activity of α-Gal. Partial least-squares regression analysis indicated that α-Gal activity was negatively associated with hydrogen bond acceptor, rotatable bond, and topological polar surface area of POPs. The results offered novel insights into the molecular mechanisms of phytotoxicity of POPs and provided important information for evaluating the environmental risk of POPs.

Will EGFRvIII and neuronal-derived EGFR be targets for imipramine?

Tricyclic antidepressant is an old and well-established therapeutic agent with a good safety profile, making them an excellent candidate for repurposing. In light of the growing understanding of the importance of nerves in the development and progression of cancer, attention is now being turned to using nerve-targeting drugs for the treatment of cancer, particularly TCAs. However, the specific mechanism by which antidepressants affect the tumor microenvironment of glioblastoma (GBM) is still unclear. Here, we combined bulk RNA sequencing, network pharmacology, single-cell sequencing, molecular docking and molecular dynamics simulation to explore the potential molecular mechanism of imipramine in the treatment of GBM. We first revealed that the imipramine treatment is presumed to target EGFRvIII and neuronal-derived EGFR, which may play a pivotal role in treating GBM by reducing the GABAergic synapse and vesicle-mediated release and other processes thereby modulating immune function. The novel pharmacological mechanisms might provide further research directions.