Exposure to PM2.5 during pregnancy causes lung inflammation in the offspring: Mechanism of action of mogrosides

Selenium maintains intestinal epithelial cells to activate M2 macrophages against deoxynivalenol injury

Selenium (Se) is indispensable in alleviating various types of intestinal injuries. Here, we thoroughly investigated the protective effect of Se on the regulation of the epithelial cell-M2 macrophages pathway in deoxynivalenol (DON)-induced intestinal damage. In the present study, Se has positive impacts on gut health by improving gut barrier function and reducing the levels of serum DON in vivo. Furthermore, our study revealed that Se supplementation increased the abundances of GPX4, p-PI3K, and AKT, decreased the levels of 4-HNE and inhibited ferroptosis. Moreover, when mice were treated with DON and Fer-1(ferroptosis inhibitor), ferroptosis was suppressed and PI3K/AKT pathway was activated. These results indicated that GPX4-PI3K/AKT-ferroptosis was a predominant pathway in DON-induced intestinal inflammation. Interestingly, we discovered that both the number of M2 anti-inflammatory macrophages and the levels of CSF-1 decreased while the pro-inflammatory cytokine IL-6 increased in the intestine and MODE-K cells supernatant. Therefore, Se supplementation activated the CSF-1-M2 macrophages axis, resulting in a decrease in IL-6 expression and an enhancement of the intestinal anti-inflammatory capacity. This study provides novel insights into how intestinal epithelial cells regulate the CSF-1-M2 macrophage pathway, which is essential in maintaining intestinal homeostasis confer to environmental hazardous stimuli.

Siraitia grosvenorii As a Homologue of Food and Medicine: A Review of Biological Activity, Mechanisms of Action, Synthetic Biology, and Applications in Future Food

Siraitia grosvenorii (SG), also known as Luo Han Guo or Monk fruit, boasts a significant history in food and medicine. This review delves into SG's historical role and varied applications in traditional Chinese culture, examining its phytochemical composition and the health benefits of its bioactive compounds. It further explores SG's biological activities, including antioxidant, anti-inflammatory, and antidiabetic properties and elucidates the mechanisms behind these effects. The review also highlights recent synthetic biology advances in enhancing the production of SG's bioactive compounds, presenting new opportunities for broadening their availability. Ultimately, this review emphasizes SG's value in food and medicine, showcasing its historical and cultural importance, phytochemistry, biological functions, action mechanisms, and the role of synthetic biology in its sustainable use.

Maternal exposure to particulate matter from duck houses restricts fetal growth due to inflammatory damage and oxidative stress

The composition of particulate matter (PM) in poultry farms differs significantly from that of atmospheric PM as there is a higher concentration of microbes on farms. To assess the health effects of PM from poultry farms on pregnant animals, we collected PM from duck houses using a particulate sampler, processed it via centrifugation and vacuum concentration, and subsequently exposed the mice to airborne PM at 0.48 mg/m3 (i.e., low concentration group) and 1.92 mg/m3 (i.e., high concentration group) on the fifth day of pregnancy. After exposure until the twentieth day of pregnancy or spontaneous delivery, mice were euthanized for sampling. The effects of PM from duck houses on the pregnancy toxicity of mice were analyzed using histopathological analysis, enzyme-linked immunosorbent assay, and quantitative real-time polymerase chain reaction (qPCR). The results showed that exposure to PM had adverse effects on pregnant mice that reduced their feed intake in both groups. Microscopic lesions were observed in the lungs and placentas of pregnant mice, and the lesions worsened with increased PM concentrations, as shown by alveolar wall thickening, the infiltration of inflammatory cells in pulmonary interstitium, congestion, edema, and cellular degeneration of placenta. In pregnant mice in the high concentration group, exposure to PM significantly increased the expression of inflammatory cytokines in the lungs and placentas, caused oxidative stress, and decreased estrogen level in the blood. Exposure to PM also resulted in the reduced litter sizes of pregnant mice and shorter body and tail lengths in the fetuses delivered. Beyond that, exposure to PM significantly downregulated the levels of antioxidant factor superoxide dismutase and neurotrophic factor Ngf in the brains of fetuses. Collectively, exposure to a high concentration of PM by inhalation among pregnant mice caused significant pregnancy toxicity that led to abnormal fetal development due to inflammatory damage and oxidative stress. These findings established a foundation for future studies on the underlying mechanisms of pregnancy toxicity induced by exposure to PM.

Mechanism of simulated lunar dust-induced lung injury in rats based on transcriptomics

Lunar dust particles are an environmental threat to lunar astronauts, and inhalation of lunar dust can cause lung damage. The current study explored the mechanism of lunar dust simulant (CLDS-i) inducing inflammatory pulmonary injury. Wistar rats were exposed to CLDS-i for 4 h/d and 7d/week for 4 weeks. Pathological results showed that a large number of inflammatory cells gathered and infiltrated in the lung tissues of the simulated lunar dust group, and the alveolar structures were destroyed. Transcriptome analysis confirmed that CLDS-i was mainly involved in the regulation of activation and differentiation of immune inflammatory cells, activated signaling pathways related to inflammatory diseases, and promoted the occurrence and development of inflammatory injury in the lung. Combined with metabolomics analysis, the results of joint analysis of omics were found that the genes Kmo, Kynu, Nos3, Arg1 and Adh7 were involved in the regulation of amino acid metabolism in rat lung tissues, and these genes might be the key targets for the treatment of amino acid metabolic diseases. In addition, the imbalance of amino acid metabolism might be related to the activation of nuclear factor kappaB (NF-κB) signaling pathway. The results of quantitative real-time polymerase chain reaction and Western blot further confirmed that CLDS-i may promote the occurrence and development of lung inflammation and lead to abnormal amino acid metabolism by activating the B cell activation factor (BAFF)/ B cell activation factor receptor (BAFFR)-mediated NF-κB signaling pathway.

Exploring the mechanism of lung injury induced by lunar dust simulant in rats based on metabolomic analysis

Inflammatory response and oxidative stress are considered to be important mechanisms of lung injury induced by lunar dust. However, the pulmonary toxicological mechanism remains unclear. In the present study, Wistar rats were exposed to CLDS-i 7 days/week, 4 h/day, for 4 weeks in the mouth and nose. Lung tissue samples were collected for histopathological analysis and ultra-performance liquid chromatography-mass spectrometry analysis. Enzyme activities and expression levels of key metabolic enzymes were detected by biochemical analysis and real-time PCR. The pathological features of lung tissue showed that CLDS-i caused congestion and inflammation in the lungs, and the lung structure was severely damaged. Metabolomics analysis showed that 141 metabolites were significantly changed in the lung tissue of the CLDS-i group compared with the control group. Combined with Kegg pathway analysis, it was found that the changes of amino acid metabolites were involved in these pathways, indicating that the simulated lunar dust exposure had the most obvious effect on amino acid metabolism in the lung tissue of rats. Real-time PCR analysis showed that the mRNA expression of six key enzymes related to amino acid metabolism was changed, and the enzyme activities of these key enzymes were also changed, which were consistent with the results of qPCR. These results suggest that changes in amino acid metabolism may be closely related to the pathogenesis of lung injury induced by lunar dust, and amino acid metabolism may be a potential biomarker of lung diseases related to lunar dust exposure.

Identification and immunological characterization of PLA2G2A and cell death-associated molecular clusters in idiopathic pulmonary fibrosis

AIMS

Idiopathic pulmonary fibrosis (IPF) is a severe pulmonary interstitial pneumonia. Our study focuses on the role of PLA2 enzyme in the IPF to explore a more effective diagnosis and treatment mechanism of IPF.

MAIN METHODS

Transcriptome data of IPF from GEO database and bleomycin-induced pulmonary fibrosis mice were analyzed to identify PLA2 enzyme and their metabolite, lysophosphatidylcholines 18:0, in IPF. Based on PLA2G2A and PLA2G2D / PLA2G2A-associated cell death genes (PCDs), the consensus clustering analysis was used to identify the subtypes of IPF and the correlation between PLA2G2A and prognosis was analyzed. The machine learning (ML) models and artificial neural network (ANN) model was used to validate the diagnostic accuracy of PLA2s and PCDs in diagnosing IPF. The gene and protein expression of NLRP3, GSDMD, and CASP-1 was estimated in recombinant PLA2G2A protein induced MLE-12 cells.

KEY FINDINGS

The expression of PLA2G2D, PLA2G2A, and LPC18 significantly changed in IPF. Furtherly, PLA2G2A has a significant correlation with poor patient prognosis, which could predict the 2 or 3-years mortality rates of IPF. Two subtypes of IPF patients, identified based on PCDs, showed significant different immunoinfiltration. Recombinant PLA2G2A protein could induce the pyrotosis in the MLE-12 cell. The generalized linear model and ANN model of PLA2s or PCDs accurate diagnosis IPF.

SIGNIFICANCE

PLA2G2A is the most robustly associated gene with IPF among the PLA2s, which demonstrates a potential in diagnosing and prognostic value in IPF, and provides a foundation for further understanding and breakthroughs in IPF diagnosis and treatment.

Advances in respiratory physiology in mouse models of experimental asthma

Recent advances in mouse models of experimental asthma coupled with vast improvements in systems that assess respiratory physiology have considerably increased the accuracy and human relevance of the outputs from these studies. In fact, these models have become important pre-clinical testing platforms with proven value and their capacity to be rapidly adapted to interrogate emerging clinical concepts, including the recent discovery of different asthma phenotypes and endotypes, has accelerated the discovery of disease-causing mechanisms and increased our understanding of asthma pathogenesis and the associated effects on lung physiology. In this review, we discuss key distinctions in respiratory physiology between asthma and severe asthma, including the magnitude of airway hyperresponsiveness and recently discovered disease drivers that underpin this phenomenon such as structural changes, airway remodeling, airway smooth muscle hypertrophy, altered airway smooth muscle calcium signaling, and inflammation. We also explore state-of-the-art mouse lung function measurement techniques that accurately recapitulate the human scenario as well as recent advances in precision cut lung slices and cell culture systems. Furthermore, we consider how these techniques have been applied to recently developed mouse models of asthma, severe asthma, and asthma-chronic obstructive pulmonary disease overlap, to examine the effects of clinically relevant exposures (including ovalbumin, house dust mite antigen in the absence or presence of cigarette smoke, cockroach allergen, pollen, and respiratory microbes) and to increase our understanding of lung physiology in these diseases and identify new therapeutic targets. Lastly, we focus on recent studies that examine the effects of diet on asthma outcomes, including high fat diet and asthma, low iron diet during pregnancy and predisposition to asthma development in offspring, and environmental exposures on asthma outcomes. We conclude our review with a discussion of new clinical concepts in asthma and severe asthma that warrant investigation and how we could utilize mouse models and advanced lung physiology measurement systems to identify factors and mechanisms with potential for therapeutic targeting.

Investigation of pulmonary toxicity evaluation on mice exposed to polystyrene nanoplastics: The potential protective role of the antioxidant N-acetylcysteine

Accumulating evidences show that the hazardous substance atmospheric nanoplastics increase the respiratory risk of individuals, but the inside toxicity mechanisms to lung tissue remain unclear. This study aims at investigating the potential mechanisms of inhaled cationic polystyrene nanoplastics (amine-polystyrene nanoplastics, APS-NPs)-induced pulmonary toxicity on mice. In vivo, the mice intratracheal administrated with APS-NPs suspension (5 mg/kg) were found inflammatory infiltrates in lung tissues through histopathology analysis. Furthermore, transcriptome analysis demonstrated that 1821 differentially expressed mRNA between APS group and control group were dominantly associated with 288 known KEGG pathways, indicating that APS-NPs might cause early inflammatory responses in lung tissue by activating the NLRP3/capase-1/IL-1β signaling pathway. Moreover, in vitro results also showed that NLRP3 inflammasome could be activated to induce pyroptosis in MLE-12 cells after exposure to APS-NPs. And, MH-S cells after exposure to APS-NPs exhibited increased Irg1 proteins, leading to the increasing generation of ROS and inflammatory factors (e.g., tnf-α, il-6, il-1β). In conclusion, these results revealed that Irg1/NF-κB/NLRP3/Caspase-1 signaling pathway was activated significantly after exposing to APS-NPs, leading to pulmonary toxicity on mice. Intriguingly, prior administration of the clinical antioxidant N-acetylcysteine (NAC) could serve as a possible candidate for the prevention and treatment of pulmonary toxicity induced by APS-NPs. The study contributes to a better understanding of the potential risks of environmental nanoplastics to humans and its improvement measure.