UHPLC/MS-based metabolomics of asthmatic mice reveals metabolic changes in group 2 innate lymphoid cells.

Helper Th2-type immune responses are essential in allergic airway diseases, including asthma and allergic rhinitis. Recent studies have indicated that group 2 innate lymphoid cells (ILC2s) play a crucial role in the occurrence and development of asthma. However, the metabolic profile of ILC2s and their regulatory mechanisms in asthma remain unclear. Therefore, we established two asthma mouse models: an ovalbumin (OVA)-induced asthma model and an IL-33-induced asthma model. We then used ultra-high-performance liquid chromatography/mass spectrometry (UHPLC/MS) to conduct high-throughput untargeted metabolic analysis of ILC2s in the lung tissues of the asthma models. The identified metabolites primarily consisted of lipids, lipid-like molecules, benzene, organic acids, derivatives, and organic oxidation compounds. Specifically, 34 differentially accumulated metabolites influenced the metabolic profiles of the control and OVA-induced asthma model groups. Moreover, the accumulation of 39 metabolites significantly differed between the Interleukin 33 (IL-33) and control groups. These differentially accumulated metabolites were mainly involved in pathways such as sphingolipid, oxidative phosphorylation, and fatty acid metabolism. This metabolomic study revealed, for the first time, the key metabolites and metabolic pathways of ILC2s, revealing new aspects of cellular metabolism in the context of airway inflammation. These findings not only contribute to unraveling the pathogenesis of asthma but also provide a crucial theoretical foundation for the future development of therapeutic strategies targeting ILC2s.

Classification models for predicting the bioactivity of pan-TRK inhibitors and SAR analysis.

Tropomyosin receptor kinases (TRKs) are important broad-spectrum anticancer targets. The oncogenic rearrangement of the NTRK gene disrupts the extracellular structural domain and epitopes for therapeutic antibodies, making small-molecule inhibitors essential for treating NTRK fusion-driven tumors. In this work, several algorithms were used to construct descriptor-based and nondescriptor-based models, and the models were evaluated by outer 10-fold cross-validation. To find a model with good generalization ability, the dataset was partitioned by random and cluster-splitting methods to construct in- and cross-domain models, respectively. Among the 48 models built, the model with the combination of the deep neural network (DNN) algorithm and extended connectivity fingerprints 4 (ECFP4) descriptors achieved excellent performance in both dataset divisions. The results indicate that the DNN algorithm has a strong generalization prediction ability, and the richness of features plays a vital role in predicting unknown spatial molecules. Additionally, we combined the clustering results and decision tree models of fingerprint descriptors to perform structure-activity relationship analysis. It was found that nitrogen-containing aromatic heterocyclic and benzo heterocyclic structures play a crucial role in enhancing the activity of TRK inhibitors. Workflow for generating predictive models for TRK inhibitors.

Complex interplay of gut microbiota between obesity and asthma in children.

Obesity is an important risk factor and common comorbidity of childhood asthma. Simultaneously, obesity-related asthma, a distinct asthma phenotype, has attracted significant attention owing to its association with more severe clinical manifestations, poorer disease control, and reduced quality of life. The establishment of the gut microbiota during early life is essential for maintaining metabolic balance and fostering the development of the immune system in children. Microbial dysbiosis influences host lipid metabolism, triggers chronic low-grade inflammation, and affects immune responses. It is intimately linked to the susceptibility to childhood obesity and asthma and plays a potentially crucial transitional role in the progression of obesity-related asthma. This review article summarizes the latest research on the interplay between asthma and obesity, with a particular focus on the mediating role of gut microbiota in the pathogenesis of obesity-related asthma. This study aims to provide valuable insight to enhance our understanding of this condition and offer preliminary evidence to support the development of therapeutic interventions.

A normalized differential sequence feature encoding method based on amino acid sequences.

Protein interactions are the foundation of all metabolic activities of cells, such as apoptosis, the immune response, and metabolic pathways. In order to optimize the performance of protein interaction prediction, a coding method based on normalized difference sequence characteristics (NDSF) of amino acid sequences is proposed. By using the positional relationships between amino acids in the sequences and the correlation characteristics between sequence pairs, NDSF is jointly encoded. Using principal component analysis (PCA) and local linear embedding (LLE) dimensionality reduction methods, the coded 174-dimensional human protein sequence vector is extracted using sequence features. This study compares the classification performance of four ensemble learning methods (AdaBoost, Extra trees, LightGBM, XGBoost) applied to PCA and LLE features. Cross-validation and grid search methods are used to find the best combination of parameters. The results show that the accuracy of NDSF is generally higher than that of the sequence matrix-based coding method (MOS) coding method, and the loss and coding time can be greatly reduced. The bar chart of feature extraction shows that the classification accuracy is significantly higher when using the linear dimensionality reduction method, PCA, compared to the nonlinear dimensionality reduction method, LLE. After classification with XGBoost, the model accuracy reaches 99.2%, which provides the best performance among all models. This study suggests that NDSF combined with PCA and XGBoost may be an effective strategy for classifying different human protein interactions.

Advances in Biosynthesis of Non-Canonical Amino Acids (ncAAs) and the Methods of ncAAs Incorporation into Proteins.

The functional pool of canonical amino acids (cAAs) has been enriched through the emergence of non-canonical amino acids (ncAAs). NcAAs play a crucial role in the production of various pharmaceuticals. The biosynthesis of ncAAs has emerged as an alternative to traditional chemical synthesis due to its environmental friendliness and high efficiency. The breakthrough genetic code expansion (GCE) technique developed in recent years has allowed the incorporation of ncAAs into target proteins, giving them special functions and biological activities. The biosynthesis of ncAAs and their incorporation into target proteins within a single microbe has become an enticing application of such molecules. Based on that, in this study, we first review the biosynthesis methods for ncAAs and analyze the difficulties related to biosynthesis. We then summarize the GCE methods and analyze their advantages and disadvantages. Further, we review the application progress of ncAAs and anticipate the challenges and future development directions of ncAAs.

Electric field simulation of multi-needle water bath electrospinning and the structural properties of SCN/PAN micro/nanofiber composite yarns.

Multi-needle water bath electrospinning is one of the most efficient methods used to prepare micro/nanofiber composite yarns. The nanofiber structure can be targeted and regulated to obtain high-performance composite yarns. To explore the effect of the receiving distance on the structure and properties of micro/nanofiber composite yarns, polyacrylonitrile nanofibers were uniformly coated on silver-coated nylon yarn via a four-needle continuous water bath electrospinning method. The electric field distribution at different receiving distances was simulated by ANSYS finite element analysis software, and the effects of electric field distribution on the structure and properties of the micro/nanofiber composite yarns were studied. The results indicated that the peak electric field intensity appeared at the tip of the needles and decreased with the increase in the receiving distance. The receiving distance was constant, and the field intensity was lower when the direction of the centerline of the needle tip was farther away from the tip; however, the field intensity at the conductive core yarn was higher than that in the surrounding area (small spikes). The average field intensity of the small spikes at 180 mm was only 1/4 of that at 80 mm. When the receiving distance increased within a certain range (100∼140 mm), the nanofibers had a smooth surface and good separation, their diameters decreased continuously and the porosity changed inversely. With a further increase in the receiving distance, the nanofibers gradually bonded, their diameter increased and the porosity showed the opposite trend. The coating rate of the nanofibers showed a decreasing trend, and the mechanical properties of the micro/nano composite yarns were improved. When the receiving distance was 100 mm, the porosity reached 38.94%, and the breaking force, breaking elongation and breaking strength were 13.71 ± 1.36 cN, 22.76 ± 6.62% and 0.15 ± 0.02 cN·dtex-1, respectively. Upon consideration of all the above factors, the receiving distance of 100 mm is appropriate.

The role of gut microbiome in the complex relationship between respiratory tract infection and asthma.

Asthma is one of the common chronic respiratory diseases in children, which poses a serious threat to children's quality of life. Respiratory infection is a risk factor for asthma. Compared with healthy children, children with early respiratory infections have a higher risk of asthma and an increased chance of developing severe asthma. Many clinical studies have confirmed the correlation between respiratory infections and the pathogenesis of asthma, but the underlying mechanism is still unclear. The gut microbiome is an important part of maintaining the body's immune homeostasis. The imbalance of the gut microbiome can affect the lung immune function, and then affect lung health and cause respiratory diseases. A large number of evidence supports that there is a bidirectional regulation between intestinal flora and respiratory tract infection, and both are significantly related to the development of asthma. The changes of intestinal microbial components and their metabolites in respiratory tract infection may affect the occurrence and development of asthma through the immune pathway. By summarizing the latest advancements in research, this review aims to elucidate the intricate connection between respiratory tract infections and the progression of asthma by highlighting its bridging role of the gut microbiome. Furthermore, it offers novel perspectives and ideas for future investigations into the mechanisms that underlie the relationship between respiratory tract infections and asthma.

Integrating concept of pharmacophore with graph neural networks for chemical property prediction and interpretation.

Recently, graph neural networks (GNNs) have revolutionized the field of chemical property prediction and achieved state-of-the-art results on benchmark data sets. Compared with the traditional descriptor- and fingerprint-based QSAR models, GNNs can learn task related representations, which completely gets rid of the rules defined by experts. However, due to the lack of useful prior knowledge, the prediction performance and interpretability of the GNNs may be affected. In this study, we introduced a new GNN model called RG-MPNN for chemical property prediction that integrated pharmacophore information hierarchically into message-passing neural network (MPNN) architecture, specifically, in the way of pharmacophore-based reduced-graph (RG) pooling. RG-MPNN absorbed not only the information of atoms and bonds from the atom-level message-passing phase, but also the information of pharmacophores from the RG-level message-passing phase. Our experimental results on eleven benchmark and ten kinase data sets showed that our model consistently matched or outperformed other existing GNN models. Furthermore, we demonstrated that applying pharmacophore-based RG pooling to MPNN architecture can generally help GNN models improve the predictive power. The cluster analysis of RG-MPNN representations and the importance analysis of pharmacophore nodes will help chemists gain insights for hit discovery and lead optimization.

Online information and support seeking during COVID-19 lockdown in Wuhan: implications for health promotion.

The lockdown that was deployed in Wuhan, China to combat the COVID-19 pandemic curbed the infection but also created great information challenges for people in social isolation. This resulted in surge in online health information seeking (OHIS) behaviors of the patients and their families. While the Internet has been widely used by Chinese public to access and search health information, there is relatively little research in the context of pandemic outbreaks, especially at the onset of a strong lockdown while many people were panicking. From a total of 10 908 '#COVID-19 Patient Seeking Help' posts on Weibo in a period of 20 days when the lockdown policy was first initiated, we identified 1496 unique patients living in or with family in Wuhan, China. Using textual analysis, we explored OHIS behaviors at the onset of the pandemic. Many faced increased difficulties accessing offline healthcare services and such turned to social media for help and information. In particular, the findings highlight the following themes: 'OHIS for medical treatment', 'OHIS to manage self-quarantine', 'OHIS for tangible support' and 'OHIS to navigate information discrepancy'. Overall, our findings provide important insights into health information seeking behaviors and the role of social media during a pandemic. Our findings also highlight the importance of considering people's information need and challenges created due to the lockdown policies in the future pandemic communication and preparedness.

From Offline to Online: Understanding Chinese Single Mothers' Uncertainty Management in Interpersonal and Online Contexts.

Divorced and unwed single motherhood is heavily stigmatized in Chinese cultural context, preventing Chinese single mothers from actively seeking the information and support needed and negatively impacting their wellbeing. Drawing on the theory of motivated information management (TMIM), this study tested how perceived stigma and cultural norms influenced Chinese single mothers' search for information and social support from families, friends as well as from online communities. Using two-wave data collected from 226 single mothers, findings support the utility of the TMIM in explaining information management and support seeking behaviors and contribute to situating the TMIM process within larger socio-cultural contexts. Practical implications regarding how to facilitate more effective uncertainty management and enhance Chinese single mothers' wellbeing in interpersonal vs. online contexts are discussed.

The Biocontrol Functions of Bacillus velezensis Strain Bv-25 Against Meloidogyne incognita.

Meloidogyne incognita is obligate parasitic nematode with a wide variety of hosts that causes huge economic losses every year. In an effort to identify novel bacterial biocontrols against M. incognita, the nematicidal activity of Bacillus velezensis strain Bv-25 obtained from cucumber rhizosphere soil was measured. Strain Bv-25 could inhibit the egg hatching of M. incognita and had strong nematicidal activity, with the mortality rate of second-stage M. incognita juveniles (J2s) at 100% within 12 h of exposure to Bv-25 fermentation broth. The M. incognita genes ord-1, mpk-1, and flp-18 were suppressed by Bv-25 fumigation treatment after 48 h. Strain Bv-25 could colonize cucumber roots, with 5.94 × 107 colony-forming units/g attached within 24 h, effectively reducing the infection rate with J2s by 98.6%. The bacteria up-regulated the expression levels of cucumber defense response genes pr1, pr3, and lox1 and induced resistance to M. incognita in split-root trials. Potted trials showed that Bv-25 reduced cucumber root knots by 73.8%. The field experiment demonstrated that disease index was reduced by 61.6%, cucumber height increased by 14.4%, and yield increased by 36.5% in Bv-25-treated plants compared with control. To summarize, B. velezensis strain Bv-25 strain has good potential to control root-knot nematodes both when colonizing the plant roots and through its volatile compounds.

Autoinducer-2-mediated quorum-sensing system resists T4 phage infection in Escherichia coli.

In response to the restriction of nutrients and predation by natural enemies, bacteria have evolved complex coping strategies to ensure the reproduction and survival of individual species. Quorum sensing (QS) is involved in the bacterial response to phage predation and regulation of cellular metabolism. However, to date, no clear evidence exists regarding the involvement of autoinducer-2 (AI-2)-mediated QS systems in Escherichia coli in response to the challenges of nutrient restriction and phage infection. In this study, the role of the AI-2-mediated QS system in resisting T4 phage infection and regulating cell mechanisms in E. coli was revealed for the first time. This effect of the AI-2-mediated QS was achieved by simultaneously downregulating the T4 absorption site and carbon and glucose metabolism. Additionally, we found that lsrB, a metabolic brake, participates in AI-2-mediated regulation and maintenance of the normal metabolic balance of cells. The novel phage defense strategy and regulation and maintenance of cellular metabolism effectively limited the expansion of the phage population.

Gendered social practices in reproductive health: A qualitative study exploring lived experiences of unwed single mothers in China.

China's family planning policy has historically silenced the voices of women, especially unwed single mothers at the expense of their reproductive health and overall wellbeing. Further, reproductive decisions in China are closely intertwined with marriage decisions and intergenerational dynamics, highlighting the relevance of gender in women's reproductive health experiences. Chinese unwed single mothers are in particular penalized for violating the gendered social norms supported by the national reproductive policies. Drawing on previous work that calls on the need to explore gender system and its influence on health, this manuscript explores the ways in which gender norms are played out for the unwed single mothers within romantic and intergenerational relations, with impacts on their reproductive health and decision-making. The findings show that reproductive decisions are interwoven with the fulfilment of other gendered identities, such as daughter, daughter-in-law and wife. Although the decision to go through unwed motherhood is reflective of their agency, the tie between childbirth and marriage does not allow the women to entirely break free from the social system. The findings also highlight the importance of considering the role of gender system that is played out within social relations, which in turn impacts the health of the women.

Lived Experiences of Unwed Single Mothers: Exploring the Relationship between Structural Violence and Agency in the Context of Chinese Reproductive Health Discourse.

China's family planning policy prioritizes the state and has historically silenced the voices of women in their own reproductive discourse. Unwed single Chinese mothers are in particular penalized and remain invisible in the national reproductive health discourse that promotes childbirth only within the institution of marriage. Drawing on Giddens' theoretical framework of structure-agency, thirty in-depth interviews were conducted to understand the lived experiences of Chinese unwed single mothers. Specifically, this study explored the ways in which structural violence is communicatively enacted in the interactions within institutions such as police station, family planning office and health care system; and interpersonal relationships such as family and neighbors that silence the voices of the unwed single mothers. Further the study also explored the ways in which the women enact their agency to navigate these macro and micro level constrains and limitations. The findings revealed that the women's experience of structural violence is often a manifestation of the state-controlled sexuality discourse in the social institutions and interpersonal relationships, and highlighted the women's agency enactment through employing various communicative behaviors to manage these day-to-day struggles.

Online Health Information Seeking Using "#COVID-19 Patient Seeking Help" on Weibo in Wuhan, China: Descriptive Study.

BACKGROUND: First detected in Wuhan, China in December 2019, the COVID-19 pandemic stretched the medical system in Wuhan and posed a challenge to the state's risk communication efforts. Timely access to quality health care information during outbreaks of infectious diseases can be effective to curtail the spread of disease and feelings of anxiety. Although existing studies have extended our knowledge about online health information-seeking behavior, processes, and motivations, rarely have the findings been applied to an outbreak. Moreover, there is relatively little recent research on how people in China are using the internet for seeking health information during a pandemic. OBJECTIVE: The aim of this study is to explore how people in China are using the internet for seeking health information during a pandemic. Drawing on previous research of online health information seeking, this study asks the following research questions: how was the "#COVID-19 Patient Seeking Help" hashtag being used by patients in Wuhan seeking health information on Weibo at the peak of the outbreak? and what kinds of health information were patients in Wuhan seeking on Weibo at the peak of the outbreak? METHODS: Using entity identification and textual analysis on 10,908 posts on Weibo, we identified 1496 patients with COVID-19 using "#COVID-19 Patient Seeking Help" and explored their online health information-seeking behavior. RESULTS: The curve of the hashtag posting provided a dynamic picture of public attention to the COVID-19 pandemic. Many patients faced difficulties accessing offline health care services. In general, our findings confirmed that the internet is used by the Chinese public as an important source of health information. The lockdown policy was found to cut off the patients' social support network, preventing them from seeking help from family members. The ability to seek information and help online, especially for those with young children or older adult members during the pandemic. A high proportion of female users were seeking health information and help for their parents or for older adults at home. The most searched information included accessing medical treatment, managing self-quarantine, and offline to online support. CONCLUSIONS: Overall, the findings contribute to our understanding of health information-seeking behaviors during an outbreak and highlight the importance of paying attention to the information needs of vulnerable groups and the role social media may play.

Non-targeted metabolomics analysis reveals dynamic changes of volatile and non-volatile metabolites during oolong tea manufacture.

Oolong tea is a partially fermented tea with distinct tastes and aromas. However, the dynamic biochemical changes during oolong tea processing are not well understood. In this study, we performed metabolomics-based profiling of non-volatile and volatile constituents of oolong tea during its entire processing procedures by UPLC-QTOF MS and GC-TOF MS. A step-wise change of tea metabolome was observed, where catechins and oxidized products, flavonol glycosides and amino acids were identified as key discriminate metabolites. The ZuoQing process comprising alternating YaoQing and TanQing steps was deemed most critical for key metabolic transformation. Extensive YaoQing facilitated the oxidative polymerizations of catechins into theaflavins and proanthocyanidins, lowering the astringency in raw tea. Two direct terpene precursors farnesyl pyrophosphate and geranyl pyrophosphate accumulated to high levels during ZuoQing, which provided more substrates for the synthesis of downstream volatile terpenes. Moreover, both YaoQing and prolonged TanQing facilitated the formation of terpenes as well as fatty acid and benzenoid-derived volatiles, which contributed to the fruity and floral fragrances in oolong tea. The fixation step not only converted amino acids into aromatic compounds, but also lowered the amounts of flavonol glycosides, potentially improving the flavor quality of the final tea product. This study provides a comprehensive profile of flavor-related metabolic changes during oolong tea processing and will contribute to better quality control and flavor improvement of oolong tea.

Magnetic recyclable CoFe2O4@PPy prepared by in situ Fenton oxidization polymerization with advanced photo-Fenton performance.

Here we present a magnetic recyclable photo-Fenton catalyst CoFe2O4@PPy with uniform morphology and excellent dispersibility prepared via simple in situ Fenton oxidization polymerization. The CoFe2O4 core provides good magnetic recyclability for the catalysts as well as the ion source for catalyzed decomposition of H2O2 in PPy coating. The optimal catalytic effect can be obtained by adjusting the ratio of CoFe2O4 and PPy. Methylene blue, Methyl orange and Rhodamine B (RhB) employed as model pollutants certificated that the catalyst exhibits a wide range of photodegradability. The decoloration rates reach nearly 100% in the photodegradation of 10 mg L-1 RhB after 2 h visible-light irradiation and only low toxicity small molecules are detected by LC-MS. Moreover, the catalytic activity remains after 5 cycles with decoloration rates up to 90%. The degradation measurement in the presence of scavengers of reactive species reveals that the positive holes (h+) and hydroxyl radical (·OH) are the main reactive oxygen species in the CoFe2O4@PPy system. The performance enhancement may be attributed to the combination of improved Fenton activity by coordinated Fe2+ and PPy redox pairs and photo-catalytic activity by broaden adsorption and photo-generated charge separation.

Strategies for the synthesis of fluorinated polyesters.

In this work we synthetized three fluorinated polyesters from dimethyl tetrafluorosuccinate (DMTFS), dimethyl hexafluoroglutarate (DMHFG), and dimethyl octafluoroadipate (DMOFA) and ethylene glycol. The influence of parameters like monomer's size, temperature, vacuum, ultrasound and catalyst, on the polyesters synthesis was evaluated. The conversion rates were assessed considering 1H NMR data and the results disclose the role of ultrasound (US) as crucial to attain high reaction conversion rates (≈20% of increase relatively to the reactions performed in absence of US). The effect of US was more relevant for the higher molecular weight monomers (DMHFG and DMOFA). The use of Candida antarctica lipase (immobilized CALB) marginally favors the synthesis reactions when fixing the other conditions. The size of the starting monomers influenced greatly the reaction conversion rates, as shorter monomers gave rise to high amount of product recovering. All the produced polyesters were isolated and fully characterized by NMR (1H and 19F), FTIR, TGA and MALDI-TOF.

Defensive Responses of Tea Plants (Camellia sinensis) Against Tea Green Leafhopper Attack: A Multi-Omics Study.

Tea green leafhopper [Empoasca (Matsumurasca) onukii Matsuda] is one of the most devastating pests of tea plants (Camellia sinensis), greatly impacting tea yield and quality. A thorough understanding of the interactions between the tea green leafhopper and the tea plant would facilitate a better pest management. To gain more insights into the molecular and biochemical mechanisms behind their interactions, a combined analysis of the global transcriptome and metabolome reconfiguration of the tea plant challenged with tea green leafhoppers was performed for the first time, complemented with phytohormone analysis. Non-targeted metabolomics analysis by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF MS), together with quantifications by ultra-performance liquid chromatography triple quadrupole mass spectrometry (UPLC-QqQ MS), revealed a marked accumulation of various flavonoid compounds and glycosidically bound volatiles but a great reduction in the level of amino acids and glutathione upon leaf herbivory. RNA-Seq data analysis showed a clear modulation of processes related to plant defense. Genes pertaining to the biosynthesis of phenylpropanoids and flavonoids, plant-pathogen interactions, and the biosynthesis of cuticle wax were significantly up-regulated. In particular, the transcript level for a CER1 homolog involved in cuticular wax alkane formation was most drastically elevated and an increase in C29 alkane levels in tea leaf waxes was observed. The tea green leafhopper attack triggered a significant increase in salicylic acid (SA) and a minor increase in jasmonic acid (JA) in infested tea leaves. Moreover, transcription factors (TFs) constitute a large portion of differentially expressed genes, with several TFs families likely involved in SA and JA signaling being significantly induced by tea green leafhopper feeding. This study presents a valuable resource for uncovering insect-induced genes and metabolites, which can potentially be used to enhance insect resistance in tea plants.

Growth, antioxidant capacity, intestinal morphology, and metabolomic responses of juvenile Oriental river prawn (Macrobrachium nipponense) to chronic lead exposure.

Understanding the mechanisms of metal toxicity to organisms farmed for food may suggest mitigation strategies. We determined the 24-, 48-, 72-, and 96-h median lethal concentrations of lead in juvenile oriental river prawn (Macrobrachium nipponense). The prawns were then exposed to sub-lethal concentrations (13.13 and 26.26 µg/L) of lead for 60 days and growth, antioxidant enzyme activity, intestinal morphology, and metabolite profiles were assessed. Prawns exposed to 26.26 µg/L but not to 13.13 µg/L lead exhibited lower weight gain than controls. The lead burden in muscle was 0.067 and 0.25 µg/g of dry weight exposed to 13.13 and 26.26 µg/L, respectively. Levels of glutamic oxaloacetic transaminase and glutamic-pyruvic transaminase were not altered following exposure. Exposure increased malondialdehyde activity in the hepatopancreas and decreased superoxide dismutase and glutathione peroxidase activities. Catalase activity first increased and then decreased as lead concentrations increased. Some intestinal epithelial cells disassociated from the basement membrane in prawns exposed to 13.13 µg/L lead. Intestinal epithelial cells in prawns exposed to 26.26 µg/L lead separated completely from the basement membrane. Gas chromatography-mass spectrometry metabolomics assays showed the 13.13-µg/L exposure did not elicit significant metabolic alterations. Exposure to 26.26 µg/L lead differentially up-regulated 58 metabolites and down-regulated 21 metabolites. The metabolites identified were involved in galactose, purine, glutathione, and carbon metabolism, biosynthesis of amino acids and steroids, and neuroactive ligand-receptor interaction. These data indicate that chronic lead exposure can adversely affect growth, increase accumulation in muscle, impair intestinal morphology, and induce oxidant stress or neurotoxicity-related effects in M. nipponense.