Enhanced O/W emulsifying properties of pea proteins via deamidation: Insights into interfacial behavior.

This study examines the effects of protein glutaminase modification on the interfacial properties and emulsion stability of pea protein isolates (PPI). Emulsions were prepared using native (NPPI) and deamidated PPI (DPPI) at concentrations from 0.5 wt% to 3.6 wt%. The stability of these emulsions was evaluated by examining droplet size distribution, flocculation index, ζ-potential, and CLSM. DPPI demonstrated superior emulsifying ability and stability, requiring only 2.0 wt% to prevent flocculation compared to NPPI's 3.6 wt%. Interfacial properties, such as protein coverage, composition, thickness, tension, and rheology, were characterized. Large Amplitude Oscillatory Dilatation analysis showed minimal differences between NPPI and DPPI-stabilized interfaces at 1 wt%. However, at 3.6 wt%, NPPI interfaces demonstrated abrupt intra-cycle yielding and viscous behavior, whereas DPPI interfaces exhibited gradual softening and a higher maximum linear strain. Additionally, DPPI showed higher interfacial protein coverage and lower interfacial tension. NPPI formed dense, brittle films prone to rupture under dynamic deformation, leading to poor stability. Deamidation of PPI unfolded the protein structure, exposing hydrophobic groups and increasing carboxyl groups, which reduced aggregation. This resulted in a uniform, extensible, and elastic interfacial film resistant to large deformations. Thus, DPPI-stabilized emulsions demonstrated superior stability, showcasing their potential for industrial applications.

Recent advances in the removal of psychoactive substances from aquatic environments: A review.

Psychoactive substances (PS) have become emerging contaminants in aquatic environments, characterized by their wide distribution, high persistence, bioaccumulation and toxicity. They are difficult to be completely removed in sewage treatment plants due to their high stability under different conditions. The incomplete removal of PS poses a threat to the aquatic animals and can also lead to human health problems through accumulation in the food chain. PS has become a huge burden on global health systems. Therefore, finding an effective technology to completely remove PS has become a "hot topic" for researchers. The methods for removal PS include physical techniques, chemical methods and biological approaches. However, there is still a lack of comprehensive and systematic exploration of these methods. This review aims to address this gap by providing a comprehensive overview of traditional strategies, highlighting recent advancements, and emphasizing the potential of natural aquatic plants in removing trace PS from water environments. Additionally, the degradation mechanisms that occur during the treatment process were discussed and an evaluation of the strengths and weaknesses associated with each method was provided. This work would help researchers in gaining a deeper understanding of the methodologies employed and serve as a reference point for future research endeavors and promoting the sustainable and large-scale application of PS elimination.

Chlorinated Anthracenes Induced Pulmonary Immunotoxicity in 3D Coculture Spheroids Simulating the Lung Microenvironment.

Chlorinated anthracenes (Cl-Ants), persistent organic pollutants, are widely detected in the environment, posing potential lung toxicity risks due to frequent respiratory exposure. However, direct evidence and a comprehensive understanding of their toxicity mechanisms are lacking. Building on our prior findings of Cl-Ants' immunotoxic risks, this study developed a three-dimensional coculture spheroid model mimicking the lung's immune microenvironment. The objective is to explore the pulmonary immunotoxicity and comprehend its mechanisms, taking into account the heightened immune reactivity and frequent lung exposure of Cl-Ants. The results demonstrated that Cl-Ants exposure led to reduced spheroid size, increased macrophage migration outward, lowered cell viability, elevated 8-OHdG levels, disturbed anti-infection balance, and altered cytokine production. Specifically, the chlorine substituent number correlates with the extent of disruption of spheroid indicators caused by Cl-Ants, with stronger immunotoxic effects observed in dichlorinated Ant compared to those in monochlorinated Ant. Furthermore, we identified critical regulatory genes associated with cell viability (ALDOC and ALDOA), bacterial response (TLR5 and MAP2K6), and GM-CSF production (CEBPB). Overall, this study offers initial in vitro evidence of low-dose Cl-PAHs' pulmonary immunotoxicity, advancing the understanding of Cl-Ants' structure-related toxicity and improving external toxicity assessment methods for environmental pollutants, which holds significance for future monitoring and evaluation.

High-throughput fitness experiments reveal specific vulnerabilities of human-adapted Salmonella during stress and infection.

Salmonella enterica is comprised of genetically distinct 'serovars' that together provide an intriguing model for exploring the genetic basis of pathogen evolution. Although the genomes of numerous Salmonella isolates with broad variations in host range and human disease manifestations have been sequenced, the functional links between genetic and phenotypic differences among these serovars remain poorly understood. Here, we conduct high-throughput functional genomics on both generalist (Typhimurium) and human-restricted (Typhi and Paratyphi A) Salmonella at unprecedented scale in the study of this enteric pathogen. Using a comprehensive systems biology approach, we identify gene networks with serovar-specific fitness effects across 25 host-associated stresses encountered at key stages of human infection. By experimentally perturbing these networks, we characterize previously undescribed pseudogenes in human-adapted Salmonella. Overall, this work highlights specific vulnerabilities encoded within human-restricted Salmonella that are linked to the degradation of their genomes, shedding light into the evolution of this enteric pathogen.

Chlorophyll a acts as a natural photosensitizer to drive nitrate reduction in nonphotosynthetic microorganisms.

With the death and decomposition of widely distributed photosynthetic organisms, free natural pigments are often detected in surface water, sediment and soil. Whether free pigments can act as photosensitizers to drive biophotoelectrochemical metabolism in nonphotosynthetic microorganisms has not been reported. In this work, we provide direct evidence for the photoelectrophic relationship between extracellular chlorophyll a (Chl a) and nonphotosynthetic microorganisms. The results show that 10 µg of Chl a can produce significant photoelectrons (∼0.34 A/cm2) upon irradiation to drive nitrate reduction in Shewanella oneidensis. Chl a undergoes structural changes during the photoelectric process, thus the ability of Chl a to generate a photocurrent decreases gradually with increasing illumination time. These changes are greater in the presence of microorganisms than in the absence of microorganisms. Photoelectron transport from Chl a to S. oneidensis occurs through a direct pathway involving the cytochromes MtrA, MtrB, MtrC and CymA but not through an indirect pathway involving riboflavin. These findings reveal a novel photoelectrotrophic linkage between natural photosynthetic pigments and nonphototrophic microorganisms, which has important implications for the biogeochemical cycle of nitrogen in various natural environments where Chl a is distributed.

CAPN5 attenuates cigarette smoke extract-induced apoptosis and inflammation in BEAS-2B cells.

INTRODUCTION: Apoptosis and chronic inflammation are the main phenotypes in chronic obstructive pulmonary disease (COPD) pathogenesis. Cigarette smoke exposure is the leading risk factor for COPD, which causes aberrant airway epithelial structure and function. As a non-classical calpain, the molecular function of calpain5 (CAPN5) in COPD remains unclear. This study investigated the role of CAPN5 in mediating cigarette smoke extract (CSE)-induced apoptosis and inflammation. METHODS: Immunohistochemistry (IHC) and Western blotting (WB) were performed to detect the location and expression of CAPN5. In vitro, BEAS-2B cells were transfected with CAPN5 siRNA or CAPN5 plasmid, followed by phosphate-buffered saline (PBS) or cigarette smoke extract (CSE) treatment. The protein expression levels of CAPN5, NF-κB p65, p-p65, IκBα, p-IκBα and apoptosis proteins (BCL-2, BAX) were measured by WB. Flow cytometry (FCM) was performed to analyze the cell apoptosis index. RESULTS: CAPN5 was mainly expressed in the airway epithelium and significantly decreased in the COPD-smoker and emphysema-mouse groups. Silencing CAPN5 significantly decreased the protein expression of BCL-2, IκBα, and increased p-p65 and BAX protein expression. Additionally, an increased apoptosis index was detected after silencing CAPN5. Moreover, overexpression of CAPN5 partly inhibited IκBα degradation and p65 activation, and reduced CSE-induced inflammation and apoptosis. CONCLUSIONS: These combined results indicate that CAPN5 could protect against CSE-induced apoptosis and inflammation, which may provide a potential therapeutic target for smoking-related COPD.

Clinical and metagenomic characteristics of lymphadenopathy related to fever of unknown origin in children.

BACKGROUND: Diagnosis of fever of unknown origin remains challenge for pediatricians. Lymphadenopathy is a separate entity that mainly originates from infection or malignancy. METHODS: 168 patients with FUO accompanied by lymphadenectasis were reviewed. 33 lymph node tissue samples were examined by mNGS. Differences in clinical characteristics were compared among different disease groups. The value of mNGS in diagnosing and improving the clinical situation was assessed. RESULTS: Multivariate analysis revealed that hepatosplenomegaly and LDH levels were associated with infectious diseases. Arthralgia was correlated with non-infectious inflammatory diseases. Weight loss and a node located in supraclavicular region may indicate neoplastic diseases. mNGS-positive rate was 60.60%, higher than that obtained with traditional methods. Treatment for 3/4 patients was adjusted according to the pathogen detected by mNGS, and antibiotics uses was discontinued or degraded in over 1/2 of the patients according to mNGS results. CONCLUSIONS: Clinical characteristics of children with lymphadenopathy related to FUO have limited diagnostic value for distinguishing different kinds of diseases, while mNGS of lymph node tissue serves as a useful tool for identifying infectious diseases, especially those caused by rare pathogens. mNGS results can lead to not only adjustments in targeted treatment but also further confirmation of underlying diseases. IMPACT STATEMENT: 1. The clinical features of children with FUO and lymphadenopathy differ according to disease group,although multivariate analysis indicated little diagnostic value for these features. 2. mNGS on lymph node tissue from children with FUO may serve as a efficient tool for distinguishing infectious diseases from other diseases. This is especially useful when a diagnosis cannot be determined with traditional methods. 3. mNGS targeted treatment can be administered in a timely manner and some underlying diseases can be indicated.

TET2 stabilized by deubiquitinase USP21 ameliorates cigarette smoke-induced apoptosis in airway epithelial cells.

DNA demethylase TET2 was related with lung function. However, the precise role of TET2 in cigarette smoke (CS)-induced apoptosis of airway epithelium cells, and the mechanisms involved, have yet to be elucidated. Here, we showed that CS decreased TET2 protein levels but had no significant effect on its mRNA levels in lung tissues of chronic obstructive pulmonary disease (COPD) patients and CS-induced COPD mice model and even in airway epithelial cell lines. TET2 could inhibit CS-induced apoptosis of airway epithelial cell in vivo and in vitro. Moreover, we identified ubiquitin-specific protease 21 (USP21) as a deubiquitinase of TET2 in airway epithelial cells. USP21 interacted with TET2 and inhibited CSE-induced TET2 degradation. USP21 downregulated decreased TET2 abundance and further reduced the anti-apoptosis effect of TET2. Thus, we draw a conclusion that the USP21/TET2 axis is involved in CS-induced apoptosis of airway epithelial cells.

Transcriptomic and Physiological Analysis of the Effects of Exogenous Phloretin and Pterostilbene on Resistance Responses of Stylosanthes against Anthracnose.

Anthracnose caused by Colletotrichum gloeosporioides is a destructive disease of Stylosanthes (stylo). Combination treatment of phloretin and pterostilbene (PP) has been previously shown to effectively inhibit the conidial germination and mycelial growth of C. gloeosporioides in vitro. In this study, the effects of PP treatment on the growth of C. gloeosporioides in vivo and the biocontrol mechanisms were investigated. We found that exogenous PP treatment could limit the growth of C. gloeosporioides and alleviate the damage of anthracnose in stylo. Comparative transcriptome analysis revealed that 565 genes were up-regulated and 239 genes were down-regulated upon PP treatment during the infection by C. gloeosporioides. The differentially expressed genes were mainly related to oxidative stress and chloroplast organization. Further physiological analysis revealed that application of PP after C. gloeosporioides inoculation significantly reduced the accumulation of O2•- level and increased the accumulation of antioxidants (glutathione, ascorbic acid and flavonoids) as well as the enzyme activity of total antioxidant capacity, superoxide dismutase, catalase, glutathione reductase, peroxidase and ascorbate peroxidase. PP also reduced the decline of chlorophyll a + b and increased the content of carotenoid in response to C. gloeosporioides infection. These results suggest that PP treatment alleviates anthracnose by improving antioxidant capacity and reducing the damage of chloroplasts, providing insights into the biocontrol mechanisms of PP on the stylo against anthracnose.

Enhancing 3D DNA Walker-Induced CRISPR/Cas12a Technology for Highly Sensitive Detection of ExomicroRNA Associated with Osteoporosis.

Exosomal microRNAs (exomiRNAs) have emerged as promising biomarkers for the early clinical diagnosis of osteoporosis. However, their limited abundance and short length in peripheral blood present significant challenges for the accurate detection of exomiRNAs. Herein, we have designed and implemented an efficacious fluorescence-based biosensor for the highly sensitive detection of exomiRNA associated with osteoporosis, leveraging the enhancing 3D DNA walker-induced CRISPR/Cas12a technology. The engineered DNA walker is capable of efficiently transforming target exomiRNA into amplifying DNA strands, thereby enhancing the sensitivity of the developed biosensor. Concurrently, the liberated DNA strands serve as activators to trigger Cas12a trans-cleavage activity, culminating in a significantly amplified fluorescent signal for the highly sensitive detection of exomiRNA-214. Under optimal conditions, the devised technology demonstrated the capacity to detect target exomiRNA-214 at concentrations as low as 20.42 fM, encompassing a wide linear range extending from 50.0 fM to 10.0 nM. Moreover, the fluorescence-based biosensor could accurately differentiate between healthy individuals and osteoporosis patients via the detection of exomiRNA-214, which was in agreement with RT-qPCR results. As such, this biosensing technology offers promise as a valuable tool for the early diagnosis of osteoporosis.

Securinine inhibits the tumor growth of human bladder cancer cells by suppressing Wnt/ß-catenin signaling pathway and activating p38 and JNK signaling pathways.

Bladder cancer (BC) is the most common malignant tumor in urinary system. Although chemotherapy is one of the most important adjuvant treatments for BC, drug resistance, non-specific toxicity and severe side effects are the major obstacles to BC chemotherapy. Natural products have always been a leading resource of antitumor drug discovery, with the advantages of excellent effectiveness, low toxicity, multi-targeting potency and easy availability. In this study, we evaluated the potential anti-tumor effect of securinine (SEC), a natural alkaloid from Securinega suffruticosa, on BC cells in vitro and in vivo, and delineated the underlying mechanism. We found that SEC inhibited the proliferation, migration and invasion, induced the apoptosis of BC cells in vitro, and retarded the xenograft tumor growth of BC cell in vivo. Notably, SEC had a promising safety profile because it presented no or low toxicity on normal cells and mice. Mechanistically, SEC inactivated Wnt/ß-catenin signaling pathway while activated p38 and JNK signaling pathway. Moreover, ß-catenin overexpression, the p38 inhibitor SB203580 and the JNK inhibitor SP600125 both mitigated the inhibitory effect of SEC on BC cells. Furthermore, we demonstrated a synergistic inhibitory effect of SEC and gemcitabine (GEM) on BC cells in vitro and in vivo. Taken together, our findings suggest that SEC may exert anti-BC cell effect at least through the activation of p38 and JNK signaling pathways, and the inhibition of Wnt/ß-catenin signaling pathway. More meaningfully, the findings indicate that GEM-induced BC cell killing can be enhanced by combining with SEC.

PU.1 alleviates the inhibitory effects of cigarette smoke on endothelial progenitor cell function and lung-homing through Wnt/ß-catenin and CXCL12/CXCR4 pathways.

INTRODUCTION: Endothelial progenitor cells (EPCs) dysfunction is involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). The transcription factor PU.1 is essential for the maintenance of stem/progenitor cell homeostasis. However, the role of PU.1 in COPD and its effects on EPC function and lung-homing, remain unclear. This study aimed to explore the protective activity of PU.1 and the underlying mechanisms in a cigarette smoke extract (CSE)-induced emphysema mouse model. METHODS: C57BL/6 mice were treated with CSE to establish a murine emphysema model and injected with overexpressed PU.1 or negative control adeno-associated virus. Morphometry of lung slides, lung function, and apoptosis of lung tissues were evaluated. Immunofluorescence co-localization was used to analyze EPCs homing into the lung. Flow cytometry was performed to detect EPC count in lung tissues and bone marrow (BM). The angiogenic ability of BM-derived EPCs cultured in vitro was examined by tube formation assay. We determined the expression levels of PU.1, ß-catenin, C-X-C motif ligand 12 (CXCL12), C-X-C motif receptor 4 (CXCR4), stem cell antigen-1 (Sca-1), and stemness genes. RESULTS: CSE exposure significantly reduced the expression of PU.1 in mouse lung tissues, BM, and BM-derived EPCs. PU.1 overexpression attenuated CSE-induced emphysematous changes, lung function decline, and apoptosis. In emphysematous mice, PU.1 overexpression markedly reversed the decreased proportion of EPCs in BM and promoted the lung-homing of EPCs. The impaired angiogenic ability of BM-derived EPCs induced by CSE could be restored by the overexpression of PU.1. In addition, PU.1 upregulation evidently reversed the decreased expression of ß-catenin, CXCL12, CXCR4, Scal-1, and stemness genes in mouse lung tissues, BM, and BM-derived EPCs after CSE exposure. CONCLUSIONS: PU.1 alleviates the inhibitory effects of CSE on EPC function and lung-homing via activating the canonical Wnt/ß-catenin pathway and CXCL12/CXCR4 axis. While further research is needed, our research may indicate a potential therapeutic target for COPD patients.

The potential beneficial effects of Lactobacillus plantarum GM11 on rats with chronic unpredictable mild stress- induced depression.

OBJECTIVE: The main purpose of the present study was to assess the beneficial effect of Lactobacillus plantarum GM11 (LacP GM11), screened from Sichuan traditional fermented food, in depressive rats induced by chronic unpredictable mild stress (CUMS). METHODS: Male SPF SD rats were randomly assigned to 3 groups: the control group, CUMS group and CUMS + LacP GM11 group (n = 10). The rats in the CUMS and LacP GM11 groups received CUMS stimulation for 42 d. The behavioral tests and levels of monoamine neurotransmitter, glucocorticoid hormone and brain-derived neurotrophic factor (BDNF) in the serum and hippocampus were measured. The effects of LacP GM11 on the mRNA and protein expression of BDNF and cAMP response element binding protein (CREB) in the hippocampus were also investigated. RESULTS: After supplementation for 21 d, LacP GM11 was associated with alleviation of depressive-like behavior, not anxiety-like behavior, in depressive rats. LacP GM11 increased the levels of 5-hydroxytryptamine (5-HT) and BDNF and decreased the level of cortisol (CORT) in the serum and hippocampus in depressed rats. In addition, treatment with LacP GM11 also increased the mRNA and protein expression of BDNF and CREB in the hippocampus. CONCLUSIONS: This work has revealed that LacP GM11 has potential beneficial effects on depression. This effect might be related to alleviating monoamine neurotransmitter deficiency, HPA axis hyperfunction and CREB-BDNF signaling pathway downregulation. This study demonstrates that LacP GM11 could be a potential therapeutic approach to treat depression and other mental health problems.

The relationship between late (≥ 7 days) systemic dexamethasone and functional network connectivity in very preterm infants.

Background: Current evidence shows that systemic dexamethasone administration starting after the first week of age reduces bronchopulmonary dysplasia for very preterm (VPT) infants, but its neurological effects remain obscure. Using resting-state functional magnetic resonance imaging (rs-fMRI), we assessed the changes in functional network connectivity (FNC) in very preterm infants treated with late systemic dexamethasone (≥7 days of age). Methods: VPT infants (GA ≤ 32 weeks) who needed to rely on mechanical ventilation for more than 7 days but fewer than 14 days to maintain vital signs were included in the study. The cohort was divided into two groups according to whether they were given systemic dexamethasone. In addition, 26 healthy term infants were recruited as controls. At term-equivalent age (TEA), rs-fMRI and 3D-T1 data from eligible infants were acquired with a 3.0-T MRI scanner. After the MRI data were preprocessed, group-level independent component analysis (ICA), a technique used for blind source separation, was used to identify the components of resting-state networks (RSNs). Then, the functional connectivity between components and RSNs was compared among different groups. Upon follow-up at 3 months of corrected age, the neurodevelopmental outcomes of enrolled infants were assessed with the Bayley Scales of Infant Development-Chinese Revision (BSID-CR), and the Motor Development Index (MDI) and Psychomotor Development Index (PDI) were measured. Finally, the correlations between resting-state FNC and BSID scores were analysed. Results: Ultimately, 59 infants were included in the final analysis, including 19 preterm infants who received dexamethasone, 20 who did not, and 20 healthy term infants as controls. Based on their data, 11 components were identified, belonging to 5 RSNs: the visual network (VN), the dorsal attention network (DAN), the auditory network (AN), the primary sensorimotor network (SMN), and the default-mode network (DMN). Compared with the term infants, the preterm infants showed significantly weakened functional connectivity between the DAN and VN, as well as the VN and AN (P < 0.05). Among preterm infants, those who were given dexamethasone showed significantly stronger functional connectivity between the DAN and VN, as well as the DMN and AN (P < 0.05), than those who were not. The correlation analysis demonstrated that the connectivity values between the DAN and VN and between the VN and AN were positively correlated with the MDI (r = 0.432, P＜0.001, and r = 0.479, P＜0.001, respectively) and the PDI (r = 0.436, P＜0.001 and r = 0.516, P＜0.001, respectively). Conclusions: Our investigation uncovers a noteworthy link between the administration of late systemic dexamethasone (≥7 days of age) in VPT infants and distinct improvements in FNC. Furthermore, the observed positive correlation between inter-network connectivity and scores on the BSID-CR implies a plausible neuroprotective aspect of this therapeutic approach in this specific group of children.

Removal of estrogens from primary settled sewage by repeated culture of Selenastrum capricornutum.

Biotransformation and biodegradation of estrogenic compounds by bacteria and even fungi have been reported widely, but the role of microalgae in the elimination of estrogens from municipal wastewater treatment plants and their interaction with other microorganisms in wastewater are not clear. This study reported the feasibility of repeatedly removing a mixture of 17ß-estradiol (E2) and 17α-ethinylestradiol (EE2), each was 100 µg L-1, from primary settled municipal sewage by Selenastrum capricornutum (SC), a ubiquitous microalga, in four exposure cycles, each lasted 7 days, and how they interacted with the microbial consortium in sewage. Mixed estrogen in sewage stimulated the growth of SC, and the indigenous microorganisms in sewage also affected the microalgal growth. The indigenous microorganisms, particularly bacteria, could easily remove E2 (with 99.5% removal), so the role of SC was insignificant. On the contrary, EE2 was difficult to remove by indigenous microorganisms but the removal was significantly enhanced by SC, with almost all spiked EE2 being removed, even at the end of the fourth cycle (with 99.0% removal). These results indicated that SC, together with the indigenous microorganisms in wastewater, could be repeatedly used for simultaneous removal of E2 and EE2 from municipal sewage.

[Characteristics and Ecological Risk Assessment of Pharmaceutical Active Compounds in Guangdong Province].

Pharmaceutically active compounds(PhACs) have become a class of new pollutants in the environment after extensive production and use of PhACs in China. To investigate the pollution characteristics of PhACs in Guangdong Province, raw sewage was collected from 186 sewage treatment plants in 21 cities, including 178 townships and administrative districts in Guangdong Province. The pollution levels of ten typical PhACs in influent water of sewage treatment plants were analyzed using automatic solid phase extraction and high performance liquid chromatography-triple quadrupole mass spectrometry. The spatial distribution characteristics of PhACs in Guangdong Province were fully revealed, and the potential ecological risks of PhACs were evaluated. The results showed that PhACs were detected in all wastewater plants, and the mass concentration of PhACs ranged from 21.00 to 9558.25 ng·L-1. Metoprolo, acetaminophen, bezafibrate, and caffeine were the main pollutants. In terms of spatial distribution, the average mass concentration of ΣPhACs in various regions of Guangdong Province was in the following order:Pearl River Delta>North Guangdong>East Guangdong≈West Guangdong. When the mass concentration of ΣPhACs was over 2500 ng·L-1 in the influent water of sewage treatment plants, the concentration of PhACs in effluent was estimated according to the sewage disposal technology. The ecological risk of PhACs was carried out based on the effluent. The results revealed that the ecological risk of PhACs was low in Guangdong Province, and the risk of bezafibrate was moderate in the cities of Shaoguan, Jiangmen, and Shenzhen. The highest ecological risk of ΣPhACs was located in Shaoguan.

Enhancing Solubility and Reducing Thermal Aggregation in Pea Proteins through Protein Glutaminase-Mediated Deamidation.

The limited solubility and stability of pea proteins hinder their utilization in liquid formulations. In this study, protein glutaminase (PG) was employed to modify pea protein isolates (PPIs) and obtain deamidated PPI with varying degrees of deamidation (DD, 10-25%). The solubility and thermal stability of these deamidated PPI samples were assessed, and a comprehensive analysis, including SDS-PAGE, zeta potential, FTIR, surface hydrophobicity, and intrinsic fluorescence, was conducted to elucidate the mechanism behind the improvement in their functional properties. The results reveal that PG modification greatly enhances the solubility and heat stability of PPI, with the most notable improvements observed at higher DD (>20%). PG modification increases the net charge of PPI, leading to the unfolding and extension of the protein structures, thus exposing more hydrophobic groups. These structural changes are particularly pronounced when DD exceeds 20%. This increased electrostatic repulsion between carboxyl groups would promote protein unfolding, enhancing interactions with water and hindering the aggregation of unfolded protein in the presence of salts at elevated temperatures (supported by high-performance size exclusion chromatography and transmission electron microscopy). Accordingly, PG-mediated deamidation shows promise in enhancing the functional properties of PPI.

Nanospray Laser-Induced Plasma Ionization Mass Spectrometry for Rapid and Sensitive Analysis of Polycyclic Aromatic Hydrocarbons and Halogenated Derivatives.

Polycyclic aromatic hydrocarbons (PAHs) and halogenated derivatives are a series of environmental pollutants with potential toxicity and health risks on biosystems and the ecosystem. Rapid and sensitive analysis of trace PAHs and halogenated PAHs in complex environmental samples is a challenging topic for analytical science. Here we report the development of a nanospray laser-induced plasma ionization MS method for rapid and sensitive analysis of trace PAHs and halogenated PAHs under ambient and open-air conditions. A nanospray tip was applied for loading samples and placed pointing to the MS inlet, being a nanospray emitter with the application of a high voltage. A beam of laser was focused to induce energetic plasma between the nanospray emitter and the MS inlet for ionization of PAHs and halogenated PAHs for mass spectrometric analysis. Meanwhile, an inner-wall naphthyl-coated nanospray emitter was developed and applied as a solid-phase microextraction (SPME) probe for highly selective enrichment of trace PAHs and halogenated PAHs in complex environmental samples, and some organic solvent was applied to desorb the analytes for nanospray laser-induced plasma ionization MS analysis. Satisfactory linearity for each target PAH and halogenated PAH was obtained, with correlation coefficient values (r) no less than 0.9917. The method showed extremely high sensitivity for analysis of trace PAHs and halogenated PAHs in water, with limits of detection (LODs) and quantification (LOQs) of 0.0001-0.02 and 0.0003-0.08 µg/L, respectively. By using the inner-wall naphthyl-coated nanospray laser-induced plasma ionization MS method, sensitive detection of trace PAHs and halogenated PAHs in real sewage and wastewater samples was successfully achieved.

DNA dioxygenases TET2 deficiency promotes cigarette smoke induced chronic obstructive pulmonary disease by inducing ferroptosis of lung epithelial cell.

Chronic obstructive pulmonary disease (COPD) is a significant global cause of morbidity and mortality currently. Long-term exposure of cigarette smoke (CS) inducing persistent inflammation, small airway remodeling and emphysematous lung are the distinguishing features of COPD. Ferroptosis, occurred in lung epithelial cells has recently been reported to be associated with COPD pathogenesis. DNA dioxygenase ten-eleven translocation 2 (TET2) is an important demethylase and its genetic mutation is associated with low forced expiratory volume in 1 s (FEV1) of lung function. However, its role in COPD remains elusive. Here, we found that TET2 regulates CS induced lipid peroxidation through demethylating glutathione peroxidase 4 (GPx4), thus alleviating airway epithelial cell ferroptosis in COPD. TET2 protein levels were mainly reduced in the airway epithelia of COPD patients, mouse models, and CS extract-treated bronchial epithelial cells. The deletion of TET2 triggered ferroptosis and further exaggerated CS-induced airway remodeling, inflammation, and emphysema in vivo. Moreover, we demonstrated that TET2 silencing intensified ferroptosis, while TET2 overexpression inhibited ferroptosis in airway epithelial cell treated with CSE. Mechanically, TET2 protected airway epithelial cells from CS-induced lipid peroxidation and ferroptosis through demethylating the promoter of glutathione peroxidase 4 (GPx4). Finally, co-administration of methylation inhibitor 5'-aza-2'-deoxycytidine (5-AZA) and the antioxidant N-acetyl-cysteine (NAC) have more protective effects on CS-induced COPD than either administration alone. Overall, our study reveals that TET2 is an essential modulator in the lipid peroxidation and ferroptosis of airway epithelial cell, and could act as a potential therapeutic target for CS-induced COPD.

CSE reduces OTUD4 triggering lung epithelial cell apoptosis via PAI-1 degradation.

Ovarian tumor family deubiquitinase 4 (OTUD4), a member of the OTU deubiquitinating enzyme, is implicated to decrease in cancer to regulate cell apoptosis. However, the role of OTUD4 in cigarette smoke induced epithelial cell apoptosis and its mechanism have not been elucidated. In this study, we showed that OTUD4 protein reduced in CSE treated mice and airway epithelial cells. OTUD4 silence aggravated cell apoptosis and emphysematous change in the lung tissue of cigarette smoke extract (CSE) treated mice. Additionally, restoration of OTUD4 in the lung of mice alleviated CSE induced apoptosis and emphysematous morphology change. The effect of OTUD4 on cell apoptosis was also confirmed in vitro. Through protein profile screening, we identified that OTUD4 may interact with plasminogen activator inhibitor 1(PAI-1). We further confirmed that OTUD4 interacted with PAI-1 for de-ubiquitination and inhibiting CSE induced PAI-1 degradation. Furthermore, the protective role of OTUD4 in airway epithelial cells apoptosis was blocked by PAI-1 deactivation. Taken together, our data suggest that OTUD4 regulates cigarette smoke (CS)-triggered airway epithelial cell apoptosis via modulating PAI-1 degradation. Targeting OUTD4/PAI-1 signaling might potentially provide a therapeutic target against the lung cell apoptosis in cigarette smoke (CS)-induced emphysema.