O-GlcNAcylation promotes topoisomerase IIα catalytic activity in breast cancer chemoresistance.

DNA topoisomerase IIα (TOP2A) plays a vital role in replication and cell division by catalytically altering DNA topology. It is a prominent target for anticancer drugs, but clinical efficacy is often compromised due to chemoresistance. In this study, we investigate the role of TOP2A O-GlcNAcylation in breast cancer cells and patient tumor tissues. Our results demonstrate that elevated TOP2A, especially its O-GlcNAcylation, promotes breast cancer malignant progression and resistance to adriamycin (Adm). O-GlcNAcylation at Ser1469 enhances TOP2A chromatin DNA binding and catalytic activity, leading to resistance to Adm in breast cancer cells and xenograft models. Mechanistically, O-GlcNAcylation-modulated interactions between TOP2A and cell cycle regulators influence downstream gene expression and contribute to breast cancer drug resistance. These results reveal a previously unrecognized mechanistic role for TOP2A O-GlcNAcylation in breast cancer chemotherapy resistance and provide support for targeting TOP2A O-GlcNAcylation in cancer therapy.

Highly Stable Solid Contact Calcium Ion-Selective Electrodes: Rapid Ion-Electron Transduction Triggered by Lipophilic Anions Participating in Redox Reactions of CunS Nanoflowers.

Solid contact (SC) calcium ion-selective electrodes (Ca2+-ISEs) have been widely applied in the analysis of water quality and body fluids by virtue of the unique advantages of easy operation and rapid response. However, the potential drift during the long-term stability test hinders their further practical applications. Designing novel redox SC layers with large capacitance and high hydrophobicity is a promising approach to stabilize the potential stability, meanwhile, exploring the transduction mechanism is also of great guiding significance for the precise design of SC layer materials. Herein, flower-like copper sulfide (CunS-50) composed of nanosheets is meticulously designed as the redox SC layer by modification with the surfactant (CTAB). The CunS-50-based Ca2+-ISE (CunS-50/Ca2+-ISE) demonstrates a near-Nernstian slope of 28.23 mV/dec for Ca2+ in a wide activity linear range of 10-7 to 10-1 M, with a low detection limit of 3.16 × 10-8 M. CunS-50/Ca2+-ISE possesses an extremely low potential drift of only 1.23 ± 0.13 µV/h in the long-term potential stability test. Notably, X-ray absorption fine-structure (XAFS) spectra and electrochemical experiments are adopted to elucidate the transduction mechanism that the lipophilic anion (TFPB-) participates in the redox reaction of CunS-50 at the solid-solid interface of ion-selective membrane (ISM) and redox inorganic SC layer (CunS-50), thereby promoting the generation of free electrons to accelerate ion-electron transduction. This work provides an in-depth comprehension of the transduction mechanism of the potentiometric response and an effective strategy for designing redox materials of ion-electron transduction triggered by lipophilic anions.

Fe-Based Nanomaterials and Plant Growth Promoting Rhizobacteria Synergistically Degrade Polychlorinated Biphenyls by Producing Extracellular Reactive Oxygen Species.

Plant growth promoting rhizobacteria (PGPR) produce extracellular reactive oxygen species (ROS) to protect plants from external stresses. Fe-based nanomaterials can potentially interact with PGPR and synergistically degrade organic pollutants, yet they have received no study. Here, we studied how the interaction between a typical PGPR (Pseudomonas chlororaphis, JD37) and Fe-based nanomaterials facilitated the degradation of 2,4,4'-trichlorobiphenyl (PCB28), by comparing the zerovalent iron of 20 nm (nZVI20), 100 nm (nZVI100), and 5 µm; iron oxide nanomaterials (α-Fe2O3, γ-Fe2O3, and Fe3O4) of ca. 20 nm; and ferrous and ferric salts. Although all Fe materials (0.1 g L-1) alone could not degrade aqueous PCB28 (0.1 mg L-1) under dark or aerobic conditions, nZVI20, nZVI100, α-Fe2O3, and Fe2+ promoted PCB28 degradation by JD37, with the half-life of PCB28 shortened from 16.5 h by JD37 alone to 8.1 h with nZVI100 cotreatment. Mechanistically, the nanomaterials stimulated JD37 to secrete phenazine-1-carboxylic acid and accelerated the NADH/NAD+ conversion, promoting O2*- generation; JD37 increased Fe(II) dissolution from the nanomaterials, facilitating *OH generation; and the ROS gradually degraded PCB28 into benzoic acid through dihydroxy substitution, oxidation to quinone, and Michael addition. These findings provide a new strategy of nanoenabled biodegradation of organic pollutants by applying Fe-based nanomaterials and PGPR.

GALNT8 suppresses breast cancer cell metastasis potential by regulating EGFR O-GalNAcylation.

Breast cancer represents the most lethal malignancy that threatens the health of females. Metastasis is the fatal hallmark of breast cancer, and current effective therapeutic targets of metastasis are still lacking. Aberrant O-GalNAcylation, which is attributed to alteration of polypeptide N-acetylgalactosaminyl transferases (GALNTs), has been implicated in cancer metastasis. However, GALNTs that drive metastasis in breast cancer and their underlying mechanisms are largely unclear. In the present study, a negative correlation between GALNT8 and the prognosis of breast cancer patients was observed in multiple groups of Gene Expression Omnibus (GEO) datasets. We then constructed a stable GALNT8 knockdown MCF7 cell line and performed transcriptome analysis using RNA sequencing, which revealed that the expression of multiple migration-related genes was changed. GALNT8 was identified as a regulator of epithelial-mesenchymal transition (EMT) markers, including E-cadherin, N-cadherin, ZO-1 and vimentin. Moreover, loss- and gain-of-function GALNT8 assays demonstrated that this glycosyltransferase inhibited the metastatic potential of breast cancer cells. Interestingly, the O-GalNAcylation of EGFR, which is the key factor related to the metastasis cascade, was impacted by GALNT8. Furthermore, our results suggested that the GALNT8-mediated O-GalNAcylation led to the suppression of the EGFR signaling pathway and metastatic potential in breast cancer cells. These results suggested that GALNT8 acts as a tumor suppressor, represses tumor metastasis and inhibits the EMT process through the EGFR signaling pathway. This finding may provide insight into the mechanism by which aberrant O-glycosylation modulates breast cancer metastasis.

Synergistic Effect of Soil Organic Matter and Nanoscale Zero-Valent Iron on Biodechlorination.

Nanoscale zero-valent iron (nZVI) provides a promising solution for organochlorine (OC)-contaminated soil remediation. However, the interactions among nZVI, soil organic matter (SOM), and indigenous dechlorinating bacteria are intricate, which may result in unascertained effects on the reductive degradation of OCs and merits specific investigation. Herein, we isolated an indigenous dehalogenation bacterium (Burkholderia ambifaria strain L3) from a paddy soil and further investigated the biodechlorination of pentachlorophenol (PCP) with individual and a combination of SOM and nZVI. In comparison with individual-strain L3 treatment, the cotreatment with nZVI or SOM increased the removal efficiency of PCP from 34.4 to 44.3-54.2% after 15 day cultivation. More importantly, a synergistic effect of SOM and nZVI was observed on the PCP removal by strain L3, and the PCP removal efficiency reached up to 75.3-84.5%. Other than the biodegradation through ortho- and meta-substitution under the individual application of SOM or nZVI, PCP was further biodegraded to 2,4,6-trichlorophenol (TCP) through para-substitution by the isolated bacteria with the cotreatment of SOM and nZVI. The main roles of the nZVI-SOM cotreatment in the biodegradation included the SOM-facilitated microbial proliferation, the nZVI-promoted microbial transformation of SOM, and the induced higher electron transport capacity of redox Fe-PCP biocycling. These findings provide a novel insight into the action of nZVI in environmental remediations.

O-GlcNAcylation promotes the migratory ability of hepatocellular carcinoma cells via regulating FOXA2 stability and transcriptional activity.

O-GlcNAcylation is a posttranslational modification that regulates numerous nuclear and cytoplasmic proteins and is emerging as a key regulator of various biological processes, such as transcription, signal transduction, and cell motility. Although increasing evidence has shown that elevated levels of global O-GlcNAcylation are linked to the metastasis in hepatocellular carcinoma (HCC) cells, the underlying mechanism is still ambiguous. In this study, we demonstrated that forkhead box protein A2 (FOXA2), an essential transcription factor for liver homeostasis and HCC developing, was O-GlcNAcylated by O-GlcNAc transferase (OGT) and regulates HCC cells migration and invasion. Opposite FOXA2 and OGT expression tendency were observed in HCC tissues, and lower FOXA2 levels predicted a poor prognosis in HCC patients. The reduction of FOXA2 in HCC cells was found to be inversely correlated with the cellular O-GlcNAcylation and cell migratory ability. Notably, we found that FOXA2 was modified by O-GlcNAcylation and that O-GlcNAcylation activated the ubiquitination degradation of FOXA2 in highly metastatic HCC cells. Although this modification did not affect FOXA2 nuclear localization capability, O-GlcNAcylation on FOXA2 was key for attenuating FOXA2-mediated transcription. O-GlcNAcylation decreased the transcription of FOXA2 downstream target gene E-cadherin and it ultimately promoted O-GlcNAcylation-mediated HCC cell migration and invasion. The results provide insights into the role of O-GlcNAcylation in regulating FOXA2 activity and suggest its important implications in HCC metastasis.

Effects of yeast culture supplementation and the ratio of non-structural carbohydrate to fat on growth performance, carcass traits and the fatty acid profile of the longissimus dorsi muscle in lambs.

The effects of yeast culture (YC) supplementation and the dietary ratio of non-structural carbohydrate to fat (NSCFR) on growth performance, carcass traits and fatty acid profile of the longissimus dorsi (LD) muscle in lambs were determined in a 2 × 3 full factorial experiment. Thirty-six Small-tailed Han lambs were randomly divided into six groups with six replicates per group. The lambs were fed one of the six pelleted total mixed rations (TMRs) for 60 days after 15 adaption days. The six rations were formed by two NSCFRs (11.37 and 4.57) and three YC supplementation levels (0, 0.8 and 2.3 g/kg dietary dry matter). The average daily gain (ADG), dry matter intake (DMI) and feed conversion ratio (FCR) data of each lamb were recorded and calculated. All the lambs were slaughtered for determining carcass traits and fatty acid profile of the LD muscle. DMI was significantly increased (p < 0.05) in a quadratic fashion with 0.8 g/kg of YC supplementation. Carcass weight (CW) and dressing percentage (DP) were significantly increased (p < 0.05) in a linear fashion with 2.3 g/kg of YC supplementation. Animals fed with high-NSCFR diet had higher (p < 0.05) contents of myristoleic acid (C14:1), pentadecanoic acid (C15:0) and cis-10-heptadecenoic acid (C17:1), and lower (p < 0.05) stearic acid (C18:0) content in LD muscle than those fed with low-NSCFR diet. Moreover, ADG, growth rate (GR), backfat thickness (BFT), percentages of crude fat (CF) and crude protein (CP), SFAs, MUFAs and PUFAs in LD muscle, were significantly affected (p < 0.05) by interaction of dietary NSCFR and supplemental YC level. Overall, YC not only improved the growth performance and carcass traits of the animals but also modified the fatty acid profile of the LD muscle. Furthermore, the effects of YC supplementation may depend on dietary compositions.

Insight into the heterogeneous adsorption of humic acid fluorescent components on multi-walled carbon nanotubes by excitation-emission matrix and parallel factor analysis.

The heterogeneous adsorption behavior of commercial humic acid (HA) on pristine and functionalized multi-walled carbon nanotubes (MWCNTs) was investigated by fluorescence excitation-emission matrix and parallel factor (EEM- PARAFAC) analysis. The kinetics, isotherms, thermodynamics and mechanisms of adsorption of HA fluorescent components onto MWCNTs were the focus of the present study. Three humic-like fluorescent components were distinguished, including one carboxylic-like fluorophore C1 (λex/λem= (250, 310) nm/428nm), and two phenolic-like fluorophores, C2 (λex/λem= (300, 460) nm/552nm) and C3 (λex/λem= (270, 375) nm/520nm). The Lagergren pseudo-second-order model can be used to describe the adsorption kinetics of the HA fluorescent components. In addition, both the Freundlich and Langmuir models can be suitably employed to describe the adsorption of the HA fluorescent components onto MWCNTs with significantly high correlation coefficients (R2> 0.94, P< 0.05). The dissimilarity in the adsorption affinity (Kd) and nonlinear adsorption degree from the HA fluorescent components to MWCNTs was clearly observed. The adsorption mechanism suggested that the π-π electron donor-acceptor (EDA) interaction played an important role in the interaction between HA fluorescent components and the three MWCNTs. Furthermore, the values of the thermodynamic parameters, including the Gibbs free energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°), showed that the adsorption of the HA fluorescent components on MWCNTs was spontaneous and exothermic.

In Situ Investigating of the Interaction of Phenanthrene and Alkyl Phenanthrene with Humic Acid with Laser Induced Nanoseconds Time Resolved Fluorescence Quenching Method.

Investigations both on the binding properties and mechanisms of parent polycyclic aromatic hydrocarbons (PAHs) and alkyl PAHs with humic acid (HA) are crucial to understand the environment behavior and bioavailability of PAHs in aquatic ecosystems. Thus, a novel approach for in situ investigation of the interactions between parent PAHs and alkyl PAHs, exemplified by Phenanthrene (Phe), 9-Ethylphenanthrene (9-EP) and Retene (Ret), and HA was established by using fluorescence quenching method with laser-induced nanosecond time-resolved fluorescence (LITRF). By changing the delay time of 50 ns, the fluorescent interference of HA can be eliminated effectively and the concentrations of free Phe, 9-EP and Ret can be determined directly. The binding characteristics of the dissolved HA and Phe, 9-EP and Ret were described by Freundlich nonlinear isothermal model. The results of the model parameters and the single point binding coefficients KOC of Phe, 9-EP and Ret with HA by LITRF quenching method were consistent with those of the conventional fluorescence quenching method. Nonlinear bindings of Phe, 9-EP and Ret to HA were also observed because of the parameter n values below 1, and the degree of nonlinearity of Phe was lower than 9-EP and Ret duo to the n value of Phe larger than 9-EP and Ret. At a same given equilibrium concentration, the KOC of Phe was lower than 9-EP and Ret, and that of 9-EP was near to Ret. The binding affinity of the three PAHs increased with decreasing the equilibrium concentration. The binding characteristics of PAHs with HA largely depends on their hydrophobicity, substituent groups and its ability to fit into hydrophobic cavities in HA. The fluorescence lifetimes of Phe, 9-EP and Ret in presence of HA were 36.90, 35.34 and 35.13 ns, meanwhile the fluorescence lifetimes of Phe, 9-EP and Ret in absence of HA were 36.36, 35.34 and 35.84 ns. There was no significant difference of three PAHs fluorescence lifetime with or without HA, indicating the quenching mechanism for Phe, 9-EP and Ret with HA were primarily static quenching. The LITRF quenching method could be used to in situ explore the interactions between PAHs and HA, which could be contribute to realize the PAHs risk assessment in real time.

Research Progress on the Mechanism and Function of Histone Acetylation Regulating the Interaction between Pathogenic Fungi and Plant Hosts.

Histone acetylation is a crucial epigenetic modification, one that holds the key to regulating gene expression by meticulously modulating the conformation of chromatin. Most histone acetylation enzymes (HATs) and deacetylation enzymes (HDACs) in fungi were originally discovered in yeast. The functions and mechanisms of HATs and HDACs in yeast that have been documented offer us an excellent entry point for gaining insights into these two types of enzymes. In the interaction between plants and pathogenic fungi, histone acetylation assumes a critical role, governing fungal pathogenicity and plant immunity. This review paper delves deep into the recent advancements in understanding how histone acetylation shapes the interaction between plants and fungi. It explores how this epigenetic modification influences the intricate balance of power between these two kingdoms of life, highlighting the intricate network of interactions and the subtle shifts in these interactions that can lead to either mutual coexistence or hostile confrontation.

Metabonomics and pharmacodynamics studies of Gentiana radix and wine-processed Gentiana radix in damp-heat jaundice syndrome rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Gentiana radix (GR) and wine-processed Gentiana radix (WGR) have been commonly used in folk medicine for the treatment of bile or liver disorders, including jaundice, hepatitis, swelling and inflammation for thousands of years. However, the therapeutic effects of gentian root (GR) and wine-made gentian root (WGR) treatment on damp-heat jaundice syndrome (DHJS) have not been studied in animal experiments. AIM OF THE STUDY: This study aimed to investigate the protective effects and mechanisms of GR and WGR on DHJS in rats. MATERIALS AND METHODS: In a high-fat and high-sugar diet in a humidified hot environment, hepatic injury induced by giving alpha-naphthalene isothiocyanate (ANIT) in rats were used as a DHJS model. Histological analysis, enzyme-linked immunosorbent assay (ELISA), PCR analysis, and metabolomics were used to elucidate the mechanism of GR and WGR for DHJS. RESULTS: The results indicated that GR and WGR affected DHJS by inhibiting the release of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), direct bilirubin (D-BIL), total bilirubin (TBIL), total bile acid (TBA), malondialdehyde (MDA), glutathione S-transferase (GST) (P < 0.05). In addition, they significantly reduced the gene expression levels of Na+/taurocholate cotransporting polypeptide (NTCP), bile salt export pump (BESP), multidrug resistance-associated protein 2 (MRP2) and multidrug resistance-associated protein 3 (MRP3) (P < 0.05). The WGR group improved the above function indicators better than the GR group. GR and WGR could restore 11 potential biomarkers in rats with DHJS tended to return to normal levels, these biomarkers were involved in arachidonic acid metabolism, steroid hormone biosynthesis, biosynthesis of unsaturated fatty acids, porphyrin and chlorophyll metabolism, retinol metabolism, arginine biosynthesis. The results of the metabolic pathway showed that WGR was significantly better than GR in the improvement of porphyrin and chlorophyll metabolism. CONCLUSIONS: These findings suggest that treatment with GR and WGR has a beneficial effect on DHJS in rats, the major mechanisms may be involved in improving functional indicators of the body and endogenous metabolism, and WGR is more effective than GR. It provides important evidence for the clinical application of GR and WGR in the treatment of DHJS.

Transforming crystal structures of cobalt molybdate to generate electron-rich sites for electrochemical detection of Pb(II).

BACKGROUND: Most of the investigations on distinct crystal structures of catalysts are individually focused on the difference of surface functional groups or adsorption properties, but rarely explore the changes of active sites to affect the electrocatalytic performance. Catalysts with diverse crystal structures had been applied to modified electrodes in different electrocatalytic reactions. However, there is currently a lack of an essential understanding for the role of real active sites in catalysts with crystalline structures in electroanalysis, which is crucial for designing highly sensitive sensing interfaces. RESULTS: Herein, cobalt molybdate with divergent crystal structures (α-CoMoO4 and ß-CoMoO4) were synthesized by adjusting the calcination temperature, indicating that α-CoMoO4 (800 °C) (60.00 µA µM-1) had the highest catalytic ability than ß-CoMoO4 (700 °C) (38.68 µA µM-1) and α-CoMoO4 (900 °C) (29.55 µA µM-1) for the catalysis of Pb(II). It was proved that the proportion of Co(II) and Mo(IV) as electron-rich sites in α-CoMoO4 (800 °C) were higher than ß-CoMoO4 (700 °C) and α-CoMoO4 (900 °C), possessing more electrons to participate in the valence cycles of Co(II)/Co(III) and Mo(IV)/Mo(VI) to boost the catalytic reduction of Pb(II). Specifically, Co(II) transferred a part of electrons to Mo(VI), promoting the formation of Mo(IV). Co(II) and Mo(IV), as the electron-rich sites, providing electrons to Pb(II), further accelerating the conversion of Pb(II) into Pb(0). SIGNIFICANCE: In the process of detecting Pb(II), the CoMoO4 structures under different temperatures have distinct content of electron-rich sites Co(II) and Mo(IV). α-CoMoO4 (800 °C), with the highest content are benefited to detect Pb(II). This work is conducive to understanding the effect of the changes of active sites resulting from crystal transformation on the electrocatalytic performance, and provides a way to construct sensitive electrochemical interfaces of distinct active sites.

Ion-Electron Transduction Layer of the SnS2-MoS2 Heterojunction to Elevate Superior Interface Stability for All-Solid Sodium-Ion Selective Electrode.

The high selectivity and fast ion response of all-solid sodium ion selective electrodes were widely applied in human sweat analysis. However, the potential drift due to insufficient interfacial capacitance leads to the deterioration of its stability and ultimately affects the potential accuracy of ion analysis. Designing a novel ion-electron transduction layer between the electrode and the ion selective membrane is an effective method to stabilize the interfacial potential. Herein, the SnS2-MoS2 heterojunction material was constructed by doping Sn in MoS2 nanosheets and used as the ion electron transduction layers of an all-solid sodium ion selective electrode for the first time, achieving the stable and efficient detection of Na+ ions. The proposed electrode exhibited a Nernst slope of 57.86 mV/dec for the detection of Na+ ions with a detection limit of 10-5.7 M in the activity range of 10-6-10-1 M. Via the electronic interaction at the heterojunction interfaces between SnS2 and MoS2 materials, the micro-nanostructure of the SnS2-MoS2 heterojunction was changed and SnS2-MoS2 as the ion-electron transduction layer acquired excellent capacitance (699 µF) and hydrophobicity (132°), resulting in a long-term potential stability of 1.37 µV/h. It was further proved that the large capacitance and high hydrophobicity of the ion-electron transduction layer are primary reasons for the excellent stability of the all-solid sodium ion selective electrode toward Na+ ions.

Characterization of dissolved organic matter in biochar derived from various macroalgae (Phaeophyta, Rhodophyta, and Chlorophyta): Effects of pyrolysis temperature and extraction solution pH.

Characterization of biochar-derived dissolved organic matter (DOM) can provide deep insight into potential applications of biochar. Herein, biochar from six macroalgae (Phaeophyta-Sargassum fusiforme, Sargassum thunbergii, and Sargassum vachellianum; Rhodophyta-Grateloupia turuturu and Chondria crassicaulis; and Chlorophyta-Ulva pertusa) were subjected to pyrolysis at different temperatures (200 °C-500 °C). The effects of pyrolysis temperature and extraction solution pH on the characteristics of the macroalgal biochar-derived DOM (MBDOM) were investigated via fluorescence excitation-emission matrix spectroscopy with parallel factor (PARAFAC) analysis. Five humic-like substances and one protein-like substance were identified. The distributions of the six PARAFAC components depended on the macroalgae species, pyrolysis temperature, and extraction solution pH. The proportion of the protein-like substance (0 %-46.77 %) was less than that of the humic-like substances (100 %-53.23 %) in a given MBDOM regardless of the extraction solution pH values. Fluorescence spectral indicators show that DOM from macroalgal biochar is more autochthonous and humified than that from the corresponding biomass. Hierarchical cluster analysis and redundancy analysis results further show that the macroalgae species, pyrolysis temperature, and extraction solution pH jointly affect DOM characteristics with varying contribution levels.

Biodegradation of sulfametoxydiazine by Alcaligenes aquatillis FA: Performance, degradation pathways, and mechanisms.

This study reports the isolation and characterization of a novel bacterial strain Alcaligenes aquatillis FA with the ability to degrade sulfametoxydiazine (SMD), a commonly used sulfonamide antibiotic (SA) in livestock and poultry production. The biodegradation kinetics, pathways, and genomic background of SMD by FA were investigated. The results showed that strain FA had high specificity to degrade SMD, and was unable to effectively degrade its isomer, sulfamonomethoxine. The SMD biodegradation followed a first-order kinetic model with a rate constant of 27.39 mg·L-1·day-1 and a half-life of 5.98 days. The biodegradation pathways and detoxification processes of SMD were proposed based on the identification of its biodegradation byproducts and the biotoxicity assessment using both the ecological structure-activity relationship (ECOSAR) model and biological indicator. The involvement of novel degrading enzymes, such as dimethyllsulfone monooxygenase, 4-carboxymuconolactone decarboxylase, and 1,4-benzoquinone reductase, was inferred in the SMD biodegradation process. The presence of sul2 and dfrA genes in strain FA, which were constitutively expressed in its cells, suggests that multiple mechanisms were employed by the strain to resist SMD. This study provides new insights into the biodegradation of sulfonamide antibiotics (SAs) as it is the first to describe an SMD-degrading bacterium and its genetic information.

Regulation and role of extracellular polymeric substances in the defensive responses of Dictyosphaerium sp. to enrofloxacin stress.

Algae are susceptible to enrofloxacin (ENR), an antibiotic frequently detected in aquatic environments. However, algal responses, especially the secretion and roles of extracellular polymeric substances (EPS), under ENR exposure remain unknown. This study is the first to elucidate the variation in algal EPS triggered by ENR at both the physiological and molecular levels. The results showed that EPS were significantly (P < 0.05) overproduced along with increased polysaccharide and protein contents in algae exposed to 0.05, 0.5, and 5 mg/L ENR. Secretion of aromatic proteins, especially tryptophan-like substances with more functional groups or aromatic rings, was specifically stimulated. Furthermore, the genes with upregulated expression related to carbon fixation, aromatic protein biosynthesis, and carbohydrate metabolism are direct causes of enhanced EPS secretion. Improved EPS levels increased the cell surface hydrophobicity and provided more adsorption sites for ENR, which strengthened the van der Waals interaction and reduced ENR internalization. The hormesis effects of ENR were alleviated, as illustrated by the less affected cell density, chlorophyll a/b, and carotenoids biosynthesis in algae with EPS. These findings demonstrate the involvement of EPS in algal ENR resistance and promote a deeper understanding of the ecological effects of ENR in aquatic environments.

Bimodal interferences of Pb(II) induced by parallel deposition in Pb(II)-Cu(II) electrochemical detections: Voltammetric signals analysis combined with numerical simulations on transient interfacial phenomena.

The perplexity of double peaks in Pb(II) detections has been a threat to the reliability of Pb(II) electroanalysis results for a long term. For the complexity of electrode interfaces, rare studies were taken on mechanisms of Pb(II) double peaks through interfacial kinetics. In this work, analyses on experimental signals and interfacial simulations were working together to reveal that the generation of Pb(II) double peaks in Pb(II)-Cu(II) systems is the deposition of Pb(II) on Cu deposits occurring in parallel. By applying anode stripping voltammetry and cyclic voltammetry, a parallel deposition reaction was found to influence the shape of Pb(II) peaks, and the existence of the second peak was controlled through the adjustment of experimental conditions. A kinetic model was built to reveal the interference of electroanalysis signals caused by a parallel deposition reaction and simulations based on the model were combined with experiments to illustrate that double peaks of Pb(II) were caused by the parallel deposition on Cu(II) deposits. This work proposes another insight of Pb(II) double peaks from macroscale kinetics and pays more attention on the dynamic procedure of electroanalysis interfaces, which makes the study on environmental electroanalysis interface phenomena more clear and is enlightening to develop efficient electrical methods for pollutant monitoring.

Fe-based nanomaterial transformation to amorphous Fe: Enhanced alfalfa rhizoremediation of PCBs-contaminated soil.

Nano-enabled phytoremediation is an emerging remediation strategy for soils that are moderately contaminated with persistent organic contaminants, and there is a significant need for increased mechanistic understanding and for case studies. Herein, we evaluated the remediation of PCB28-contaminated soil using combined alfalfa and Fe-based materials, including zero-valent iron at 20 nm, 100 nm, and 5 µm, and also iron oxide nanomaterials including α-Fe2O3, γ-Fe2O3, and Fe3O4 around 20-30 nm. Compared with alfalfa remediation alone (63.2%), Fe-based nanomaterials increased PCB28 removal values to 72.4-93.5% in planted soil, with α-Fe2O3 treatment promoting the most effective pollutant removal. Mechanistically, the crystalline Fe-based nanoparticles were transformed into amorphous forms in the plant rhizosphere, resulting in greater availability and enhanced iron nutrition. This nutritional shift induced root metabolic reprogramming of amino acid and carbohydrate cycling, and related functional bacterial enrichment of Ramlibacter, Dyella, Bacillus, and Paraburkholderia in rhizosphere. A significant positive correlation between amorphous iron and root metabolites-associated microbes with PCB28 removal was evident, implying that iron supplementation selected for rhizospheric microorganisms favored PCBs degradation. Overall, this rhizoremediation promotion strategy of Fe species-metabolites-microbes highlights the potential for the hybrid application of nano-enabled phytotechnology in the remediation of soils contaminated with persistent organic xenobiotics.

Expression of GALNT8 and O-glycosylation of BMP receptor 1A suppress breast cancer cell proliferation by upregulating ERα levels.

BACKGROUND: Mucin-type O-glycosylation is one of the most abundant types of O-glycosylation and plays important roles in various human carcinomas, including breast cancer. A large family of polypeptide N-acetyl-α-galactosaminyltransferases (GALNTs) initiate and define sites of mucin-type O-glycosylation. However, the specific mechanisms underlying GALNT8 expression and its roles in tumorigenesis remain poorly characterized. METHODS: GALNT8 expression was assessed in 140 breast cancer patients. Immunofluorescence, immunoprecipitation, lectin blot and quantitative real-time PCR were used to investigate the expression of GALNT8 and its role in regulating estrogen receptor α (ERα) via bone morphogenetic protein (BMP) signaling. RESULTS: The expression of GALNT8 was associated with breast cancer patient survival. GALNT8 downregulation was associated with a reduction in ERα levels, while GALNT8 overexpression elevated the transcription and protein levels of ERα and suppressed colony formation, suggesting an important role of GALNT8 in cancer cell proliferation. Conversely, GALNT8 knockdown led to the inhibition of BMP/SMAD/RUNX2 axis, which decreased ERα transcription. Further analysis suggested that BMP receptor 1A (BMPR1A) was O-GalNAcylated. Sites mutation of BMPR1A indicated that Thr137 and Ser37/Ser39/Ser44/Thr49 of BMPR1A were the main O-glycosylation sites. Although we cannot exclude the indirect effect of GALNT8, our results demonstrated that the expression of GALNT8 and O-glycosylation of BMPR1A play key roles in regulating the activity of BMP/SMAD/RUNX2 signaling and ERα expression. CONCLUSION: These findings suggest that GALNT8 expression and abnormal O-GalNAcylation of BMPR1A increase ERα expression and suppress breast cancer cell proliferation by modulating the BMP signaling pathway. GENERAL SIGNIFICANCE: Our results identify the involvement of GALNT8 in regulating ERα expression.

Transformation and implication of nanoparticulate zero valent iron in soils.

Knowledge of nanoparticulate zero-valent iron (nZVI) transformation in soils and its relationship with the potential impacts on soil properties are crucial to evaluate the environmental implication and application of nZVI. This study investigated nZVI transformation and the effects on soil properties in eight soils with various ageing time and soil moisture content (SMC). Spherical nZVI was gradually oxidized, collapsed, and adhered to clay minerals, and crystalline maghemite and magnetite were the primary oxidation products. Compared with the flooded condition, nZVI oxidation was accelerated under 70% SMC but was limited under 30% SMC. Acidic soil with lower content of dissolved aromatic carbon was advantage to nZVI oxidation under the flooded condition, while carboxymethylcellulose coating and iron oxides on nZVI surface limited nZVI oxidation. The aged nZVI existed mainly in the form of association with soil mineral or organic matter rather than in ion-exchangeable or carbonate form. nZVI treatment promoted soil aromatic carbon sequestration and decreased soil redox potential, and the impacts of nZVI on soil pH, electrical conductivity, ζ-potential, dissolved organic carbon, and catalase and urease activities were dependent on soil type and SMC. The findings are of significance for the evaluation of the environmental risk and proper application of nZVI.