Origami Morphing Surfaces with Arrayed Quasi-Rigid-Foldable Polyhedrons.

Artificial morphing surfaces, inspired by the high adaptability of biological tissues, have emerged as a significant area of research in recent years. However, the practical applications of these surfaces, constructed from soft materials, are considerably limited due to their low shear stiffness. Rigid-foldable cylinders are anisotropic structures that exhibit high adaptability and shear stiffness. Thus, they have the potential to address this issue. However, changes in shape and area at both ends during folding can lead to collisions or gaps on the morphing surface. Here, a quasi-rigid-foldable (QRF) rate is first introduced to quantify the rigid-foldability of a foldable structure and validate it through experiments. More importantly, a QRF polyhedron is then proposed, which is not only notably anisotropic, similar to a rigid-foldable cylinder, but also exhibits a zero-Poisson's ratio property, making it suitable for arraying as morphing surfaces without any collisions or gaps. Such surfaces have a myriad of applications, including modulating electromagnetic waves, gripping fragile objects, and serving as soles for climbing robots.

Charge Generation Dynamics in Organic Photovoltaic Blends under One-Sun-Equivalent Illumination Detected by Highly Sensitive Terahertz Spectroscopy.

Organic photovoltaic (OPV) devices attain high performance with nonfullerene acceptors by utilizing the synergistic dual channels of charge generation that originate from excitations in both the donor and acceptor materials. However, the specific intermediate states that facilitate both channels are subject to debate. To address this issue, we employ time-resolved terahertz spectroscopy with improved sensitivity (ΔE/E < 10-6), enabling direct probing of charge generation dynamics in a prototypical PM6:Y6 bulk heterojunction system under one-sun-equivalent excitation density. Charge generation arising from donor excitations is characterized with a rise time of ∼9 ps, while that from acceptor excitations shows a rise time of ∼18 ps. Temperature-dependent measurements further reveal notably distinct activation energies for these two charge generation pathways. Additionally, the two channels of charge generation can be substantially manipulated by altering the ratio of bulk to interfaces. These findings strongly suggest the presence of two distinct intermediate states: interfacial and intramoiety excitations. These states are crucial in mediating the transfer of electrons and holes, driving charge generation within OPV devices.

Selective scission of glucose molecule by a Pd-modulated Co-based catalyst for efficient CO2 reduction under mild conditions.

Combining terrestrial biomass as the reductant with submarine-type hydrothermal environments for CO2 reduction represents a possible approach for novel energy production systems that sustainably circulate carbon. However, increasing the reductive power of biomass is the main limitation of this potential method. Herein, we demonstrate that Co-doped with small amounts of Pd enhances the reduction of CO2 by selectively producing an active intermediate from carbohydrates. This catalytic reaction utilized glucose as a reductant to achieve high formate production efficiency (458.6 g kg-1) with nearly 100% selectivity with 7.5 wt% Pd1Co20/γ-Al2O3 at a moderate temperature of 225 °C. The regulation of the electronic structure of the catalytic Co surface by the dopant Pd plays a key role in promoting the C-C bond cleavage of glucose and hydrogen transfer for CO2 reduction. The findings presented here indicate that biomass can serve as the hydrogen source for CO2 reduction and provide insight into the potential utilization of CO2 in sustainable industrial applications.

Fiber Optic LSPR Sensing AFM1 in Milk with Enhanced Sensitivity by the Hot Spot Effect Based on Nanogap Construction.

The detection of the amount of aflatoxin M1 (AFM1) in milk is crucial for food safety. Here, we utilize a fiber optic (FO) localized surface plasmon resonance (LSPR) biosensor by constructing gold nanoparticle (AuNP) multimers, in which the nanogaps amplified the LSPR signal by the hot spot effect, and achieved a highly sensitive detection of f AFM1. Through the optimization of parameter conditions for the fabrication of the sensor and detection system, a high performance result from the FO LSPR biosensor was obtained, and the method for AFM1 detection was established, with a wide detection range of 0.05-100 ng/mL and a low limit of detection (LOD) of 0.04 ng/mL, and it has been successfully validated with the actual sample milk. Therefore, it is a good strategy to fabricate highly sensitive FO LSPR sensors for detecting AFM1 by constructing AuNP multimers, and this approach is suitable for developing other biosensors.

Development and evaluation of a risk prediction tool for risk-adapted screening of colorectal cancer in China.

Risk prediction tools for colorectal cancer (CRC) have potential to improve the efficiency of population-based screening by facilitating risk-adapted strategies. However, such an applicable tool has yet to be established in the Chinese population. In this study, a risk score was created using data from the China Kadoorie Biobank (CKB), a nationwide cohort study of 409,854 eligible participants. Diagnostic performance of the risk score was evaluated in an independent CRC screening programme, which included 91,575 participants who accepted colonoscopy at designed hospitals in Zhejiang Province, China. Over a median follow-up of 11.1 years, 3136 CRC cases were documented in the CKB. A risk score was created based on nine questionnaire-derived variables, showing moderate discrimination for 10-year CRC risk (C-statistic = 0.68, 95 % CI: 0.67-0.69). In the CRC screening programme, the detection rates of CRC were 0.25 %, 0.82 %, and 1.93 % in low-risk (score <6), intermediate-risk (score: 6-19), and high-risk (score >19) groups, respectively. The newly developed score exhibited a C-statistic of 0.65 (95 % CI: 0.63-0.66), surpassing the widely adopted tools such as the Asia-Pacific Colorectal Screening (APCS), modified APCS, and Korean Colorectal Screening scores (all C-statistics = 0.60). In conclusion, we developed a novel risk prediction tool that is useful to identify individuals at high risk of CRC. A user-friendly online calculator was also constructed to encourage broader adoption of the tool.

Picosecond Spin Current Generation from Vicinal Metal-Antiferromagnetic Insulator Interfaces.

We report the picosecond spin current generation from the interface between a heavy metal and a vicinal antiferromagnet insulator Cr_{2}O_{3} by laser pulses at room temperature and zero magnetic field. It is converted into a detectable terahertz emission in the heavy metal via the inverse spin Hall effect. The vicinal interfaces are apparently the source of the picosecond spin current, as evidenced by the proportional terahertz signals to the vicinal angle. We attribute the origin of the spin current to the transient magnetic moment generated by an interfacial nonlinear magnetic-dipole difference-frequency generation. We propose a model based on the in-plane inversion symmetry breaking to quantitatively explain the terahertz intensity with respect to the angles of the laser polarization and the film azimuth. Our work opens new opportunities in antiferromagnetic and ultrafast spintronics by considering symmetry breaking.

Prognostic value of tumor deposits and positive lymph node ratio in stage III colorectal cancer: a retrospective cohort study.

BACKGROUND: In colorectal cancer (CRC), tumor deposits (TD) have been used to guide the N staging only in node-negative patients. It remains unknown about the prognostic value of TD in combination with positive lymph node ratio (LNR) in stage III CRC. PATIENTS AND METHODS: The authors analyzed data from 31 139 eligible patients diagnosed with stage III CRC, including 30 230 from the Surveillance, Epidemiology, and End Results (SEER) database as a training set and 909 from two Chinese hospitals as a validation set. The associations of TD and LNR with cancer-specific survival (CSS) and overall survival (OS) were evaluated using the Kaplan-Meier method and Cox regression models. RESULTS: Both TD-positive and high LNR (value ≥0.4) were associated with worse CSS in the training [multivariable hazard ratio (HR), 1.50; 95% CI: 1.43-1.58 and HR, 1.74; 95% CI: 1.62-1.86, respectively] and validation sets (HR, 1.90; 95% CI: 1.41-2.54 and HR, 2.01; 95% CI: 1.29-3.15, respectively). Compared to patients with TD-negative and low LNR (value<0.4), those with TD-positive and high LNR had a 4.09-fold risk of CRC-specific death in the training set (HR, 4.09; 95% CI: 3.54-4.72) and 4.60-fold risk in the validation set (HR, 4.60; 95% CI: 2.88-7.35). Patients with TD-positive/H-LNR CRC on the right side had the worst prognosis ( P <0.001). The combined variable of TD and LNR contributed the most to CSS prediction in the training (24.26%) and validation (32.31%) sets. A nomogram including TD and LNR showed satisfactory discriminative ability, and calibration curves indicated favorable consistency in both the training and validation sets. CONCLUSIONS: TD and LNR represent independent prognostic predictors for stage III CRC. A combination of TD and LNR could be used to identify those at high-risk of CRC deaths.

Four New Isocoumarins from the Mangrove Fungus Alternaria Malorum with Antimicrobial Activities.

Four new isocoumarins, alternariethers A-C (1-3) and alternariester (4) were separated from the fermentation of the fungus Alternaria malorum FL39, purified from Myoporum bontioides. Their structures were ascertained using NMR and HR-ESI-MS spectroscopy. For compound 4, the absolute configuration was solved with the help of ECD calculation and the DP4+ method. Compared with the positive control triadimefon, compound 1 showed more potent antifungal effects on Colletotrichum musae. The antifungal effects of compounds 1, 2, and 3 on Fusarium oxysporum and Fusarium graminearum, of compound 4 on F. oxysporum, were equal to those of triadimefon. Except for compound 4 which was inactive against Escherichia coli with O78 serotype, all compounds showed moderate or weak antibacterial activity against Staphylococcus aureus ATCC 6538 and E. coli with O6 or O78 serotype.

Construction and analysis of a network of exercise-induced mitochondria-related non-coding RNA in the regulation of diabetic cardiomyopathy.

Diabetic cardiomyopathy (DCM) is a major factor in the development of heart failure. Mitochondria play a crucial role in regulating insulin resistance, oxidative stress, and inflammation, which affect the progression of DCM. Regular exercise can induce altered non-coding RNA (ncRNA) expression, which subsequently affects gene expression and protein function. The mechanism of exercise-induced mitochondrial-related non-coding RNA network in the regulation of DCM remains unclear. This study seeks to construct an innovative exercise-induced mitochondrial-related ncRNA network. Bioinformatic analysis of RNA sequencing data from an exercise rat model identified 144 differentially expressed long non-coding RNA (lncRNA) with cutoff criteria of p< 0.05 and fold change ≥1.0. GSE6880 and GSE4745 were the differentially expressed mRNAs from the left ventricle of DCM rat that downloaded from the GEO database. Combined with the differentially expressed mRNA and MitoCarta 3.0 dataset, the mitochondrial located gene Pdk4 was identified as a target gene. The miRNA prediction analysis using miRanda and TargetScan confirmed that 5 miRNAs have potential to interact with the 144 lncRNA. The novel lncRNA-miRNA-Pdk4 network was constructed for the first time. According to the functional protein association network, the newly created exercise-induced ncRNA network may serve as a promising diagnostic marker and therapeutic target, providing a fresh perspective to understand the molecular mechanism of different exercise types for the prevention and treatment of diabetic cardiomyopathy.

Pain-free oral delivery of biologic drugs using intestinal peristalsis-actuated microneedle robots.

Biologic drugs hold immense promise for medical treatments, but their oral delivery remains a daunting challenge due to the harsh digestive environment and restricted gastrointestinal absorption. Here, inspired by the porcupinefish's ability to inflate itself and deploy its spines for defense, we proposed an intestinal microneedle robot designed to absorb intestinal fluids for rapid inflation and inject drug-loaded microneedles into the insensate intestinal wall for drug delivery. Upon reaching the equilibrium volume, the microneedle robot leverages rhythmic peristaltic contraction for mucosa penetration. The robot's barbed microneedles can then detach from its body during peristaltic relaxation and retain in the mucosa for drug releasing. Extensive in vivo experiments involving 14 minipigs confirmed the effectiveness of the intestinal peristalsis for microrobot actuation and demonstrated comparable insulin delivery efficacy to subcutaneous injection. The ingestible peristalsis-actuated microneedle robots may transform the oral administration of biologic drugs that primary relies on parenteral injection currently.

Serum apolipoproteins and mortality risk: evidence from observational and Mendelian randomization analyses.

BACKGROUND: Apolipoproteins (APOs) have emerged as significant players in lipid metabolism that affects the risk of chronic disease. However, the impact of circulating APO concentrations on premature death remains undetermined. OBJECTIVES: This study aimed to investigate the associations of serum APOs with all-cause, cardiovascular disease (CVD)-related, and cancer-related mortality. METHODS: We included 340,737 participants who had serum APO measurements from the UK Biobank. Restricted cubic splines and multivariable Cox regression models were used to assess the associations between APOs and all-cause and cause-specific mortality by computing hazard ratios (HRs) and 95% confidence intervals (CIs). Based on 1-sample Mendelian randomization (MR) design, including 398,457 participants of White ancestry who had genotyping data from the UK Biobank, we performed instrumental variable analysis with 2-stage least squares regression to assess the association between genetically predicted APOs and mortality. RESULTS: After adjusting for potential confounders including high-density and low-density lipoprotein particles, we observed nonlinear inverse relationships of APOA1 with all-cause, CVD-related, and cancer-related mortality (P-nonlinear < 0.001). By contrast, positive relationships were observed for APOB and all-cause (P-nonlinear < 0.001), CVD-related (P-linear < 0.001), and cancer-related (P-linear = 0.03) mortality. MR analysis showed consistent results, except that the association between APOB and cancer mortality was null. Furthermore, both observational and MR analyses found an inverse association between APOA1 and lung cancer-related mortality (HR comparing extreme deciles: 0.46; 95% CI: 0.26, 0.80; and HR: 0.78; 95% CI: 0.63, 0.97, respectively). CONCLUSIONS: Our findings indicate that circulating APOA1 has potential beneficial effects on all-cause, CVD-related, and lung cancer-related death risk, whereas APOB may confer detrimental effects on all-cause and CVD-related death risk.

Microplastics induced apoptosis in macrophages by promoting ROS generation and altering metabolic profiles.

The ubiquitous presence of Microplastics (MPs) in various environments documented in recent years has recently raised significant concerns about their toxic effects. While macrophages serve as the first line of defense against toxic substances and pathogens, the impact and mechanisms of microplastics on these immune cells remain unclear. This study aims to explore whether MPs induce macrophage apoptosis through the promotion of reactive oxygen species (ROS) generation and alterations in metabolic profiles. The viability of RAW264.7 cells decreased as the concentration of 0.5 µm or 5 µm MPs ranged from 0.2 to 1.5 mg/mL, with a more pronounced effect observed in the 0.5 µm MPs group. Zebrafish exposed to 0.5 µm or 5 µm MPs at a concentration of 0.5 mg/mL exhibited decreased macrophage abundance and increased apoptosis, accompanied by alterations in the expression of inflammatory and apoptosis-related genes. While 0.5 µm MPs were observed to enter macrophages, 5 µm MPs only adhered to the cell membrane surface. Both particle sizes induced ROS generation and disrupted cellular metabolism in RAW264.7 cells. Notably, macrophages exhibited a more pronounced response to 0.5 µm MPs, characterized by heightened ROS generation, increased secretion of pro-inflammatory mediators, and a significant decrease in sphingolipid metabolism. These findings suggest that the adverse effects on macrophages are greater with 0.5 µm MPs compared to 5 µm MPs, possibly attributed to particle size effects. This study contributes additional evidence on the impact of MPs on human immune cells.

Improved cardioprotective effect of 3-nitro-N-methyl salicylamide solution after a prolonged preservation time of rat heart.

Ischemic reperfusion injury, caused by oxidative stress during reperfusion, is an inevitable outcome of organ transplantation, especially when the organ preservation time is prolonged. Prolonged ischaemic preservation is a valuable technique for improving the success of organ transplantation, but numerous challenges remain. 3-nitro-N-methyl salicylamide (3-NNMS), an inhibitor of mitochondrial electron transport chain complex III, can be used to reduce reactive oxygen species production during blood reperfusion by slowing the electron flow rate of the respiratory chain. Based on this property, a novel preservation solution was developed for the preservation of isolated rat heart and its cardioprotective effect was investigated during an 8-h cold ischaemia preservation time for the first time. For comparison, 3-NNMS was also included in the histidine-tryptophan-ketoglutarate (HTK) solution. Compared to HTK, HTK supplemented with 3-NNMS significantly improved the heart rate of isolated rat hearts after 8 h of cold storage. Both 3-NNMS solution and HTK supplemented with 3-NNMS solution decreased cardiac troponin T and lactate dehydrogenase levels in perfusion fluid and reduced reactive oxygen species and malondialdehyde levels in the myocardium. The 3-NNMS also maintained the membrane potential of myocardial mitochondria and significantly increased superoxide dismutase levels. These results showed that the new 3-NNMS solution can protect mitochondrial and cardiomyocyte function by increasing antioxidant capacity and reducing oxidative stress in cryopreserved rat hearts during a prolonged preservation time, resulting in less myocardial injury and better heart rate.

Amuc_1100 pretreatment alleviates acute pancreatitis in a mouse model through regulating gut microbiota and inhibiting inflammatory infiltration.

Amuc_1100 is a membrane protein from Akkermansia muciniphila, which has been found to play a role in host immunological homeostasis in the gastrointestinal tract by activating TLR2 and TLR4. In this study we investigated the effects and underlying mechanisms of Amuc_1100 on acute pancreatitis (AP) induced in mice by intraperitoneal injection of caerulein and lipopolysaccharide (LPS). The mice were treated with the protein Amuc_1100 (3 µg, i.g.) for 20 days before caerulein injection. Cecal contents of the mice were collected for 16S rRNA sequencing. We found that pretreatment with Amuc_1100 significantly alleviated AP-associated pancreatic injury, reduced serum amylase and lipase. Amuc_1100 pretreatment significantly inhibited the expression of proinflammatory cytokines (TNF-α, IL-1ß, IFN-γ and IL-6) in spleen and pancreas through inhibiting NF-κB signaling pathway. Moreover, Amuc_1100 pretreatment significantly decreased the inflammatory infiltration, accompanied by the reduction of Ly6C+ macrophages and neutrophils in the spleen of AP mice. Gut microbiome analysis showed that the abundance of Bacteroidetes, Proteobacteria, Desulfobacterota and Campilobacterota was decreased, while the proportion of Firmicutes and Actinobacteriota was increased in AP mice pretreated with Amuc_1100. We further demonstrated that Amuc_1100 pretreatment restored the enrichment of tryptophan metabolism, which was mediated by intestinal flora. These results provide new evidence that Amuc_1100 lessens the severity of AP through its anti-inflammatory properties with a reduction of macrophages and neutrophil infiltration, as well as its regulation of the composition of intestinal flora and tryptophan metabolism.

Identification of a Potential Antimycobacterial Drug Sensitizer Targeting a Flavin-Independent Methylenetetrahydrofolate Reductase.

The increasing antibiotic resistance of Mycobacterium tuberculosis and pathogenic nontuberculosis mycobacteria highlights the urgent need for new prevention and treatment strategies. Recently, the cocrystal structure of a Mycobacterium smegmatis flavin-independent 5,10-methylenetetrahydrofolate reductase (MsmMTHFR) that binds with a reduced nicotinamide adenine dinucleotide (NADH) has been well-determined, providing a structural basis for the screening of antimycobacterial leads targeting MsmMTHFR, a new enzyme involved in tetrahydrofolic acid (THF) biosynthesis. In this study, we identified compound AB131 as a promising candidate that fits well into the NADH binding pocket of MsmMTHFR through virtual screening. We discovered that AB131 and its derivatives (13 and 14) can sensitize the antimycobacterial activity of the antitubercular drug para-aminosalicyclic acid (PAS) by 2-5-fold against various species of mycobacteria. Although the compounds themselves do not exhibit any antimycobacterial activity, the high binding affinity of AB131 with MsmMTHFR or Rv2172c was evaluated by microscale thermophoresis analysis. Additionally, we predicted and validated the key residues (V115, V117, P118, and R163) of MsmMTHFR that are involved in the interaction with AB131 by using molecular docking and mutagenesis analysis. These findings offer a potential exploitable target for developing potent and specific antimycobacterial drug sensitizers.

Structural and functional characterization of a mycobacterial methylenetetrahydrofolate reductase utilizing NADH as the exclusive cofactor.

5,10-Methylenetetraydrofolate reductase (MTHFR) is a key enzyme in folate metabolism. MSMEG_6649, a non-canonical MTHFR from Mycobacterium smegmatis, was previously reported as a monomeric protein lacking the flavin coenzyme. However, the structural basis for its unique flavin-independent catalytic mechanism remains poorly understood. Here, we determined the crystal structures of apo MTHFR MSMEG_6649 and its complex with NADH from M. smegmatis. Structural analysis revealed that the groove formed by the loops 4 and 5 of non-canonical MSMEG_6649 interacting with FAD was significantly larger than that of canonical MTHFR. Meanwhile, the NADH-binding site in MSMEG_6649 is highly similar to the FAD binding site in canonical MTHFR, suggesting that NADH plays the same role (immediate hydride donor for methylenetetraydrofolate) as FAD in the catalytic reaction. Using biochemical analysis, molecular modeling, and site-directed mutagenesis, the critical residues participating in the binding of NADH and the substrate 5,10-methylenetetrahydrofolate as well as the product 5-methyltetrahydrofolate were identified and validated. Taken together, this work not only provides a good starting point for understanding the potential catalytic mechanism for MSMEG_6649, but also identifies an exploitable target for the development of anti-mycobacterial drugs.

Development and validation of a blood biomarker score for predicting mortality risk in the general population.

BACKGROUND: Blood biomarkers for multiple pathways, such as inflammatory response, lipid metabolism, and hormonal regulation, have been suggested to influence the risk of mortality. However, few studies have systematically evaluated the combined predictive ability of blood biomarkers for mortality risk. METHODS: We included 267,239 participants from the UK Biobank who had measurements of 28 blood biomarkers and were free of cardiovascular disease (CVD) and cancer at baseline (2006-2010). We developed sex-specific blood biomarker scores for predicting all-cause mortality risk in a training set of 247,503 participants from England and Wales, and validated the results in 19,736 participants from Scotland. Cox and LASSO regression analyses were performed to identify independent predictors for men and women separately. Discrimination and calibration were evaluated by C-index and calibration plots, respectively. We also assessed mediating effects of the biomarkers on the association between traditional risk factors (current smoking, obesity, physical inactivity, hypertension, diabetes) and mortality. RESULTS: A total of 13 independent predictive biomarkers for men and 17 for women were identified and included in the score development. Compared to the lowest tertile of the score, the highest tertile showed a hazard ratio of 5.36 (95% confidence interval [CI] 5.04-5.71) in men and 4.23 (95% CI 3.87-4.62) in women for all-cause mortality. In the validation set, the score yielded a C-index of 0.73 (95% CI 0.72-0.75) in men and 0.70 (95% CI 0.68-0.73) in women for all-cause mortality; it was also predictive of CVD (C-index of 0.76 in men and 0.79 in women) and cancer (C-index of 0.70 in men and 0.67 in women) mortality. Moreover, the association between traditional risk factors and all-cause mortality was largely mediated by cystatin C, C-reactive protein, 25-hydroxyvitamin D, and hemoglobin A1c. CONCLUSIONS: We established sex-specific blood biomarker scores for predicting all-cause and cause-specific mortality in the general population, which hold the potential to identify high-risk individuals and improve targeted prevention of premature death.

Discrimination of wheat flour grade based on PSO-SVM of hyperspectral technique.

Rapid detection of wheat flour grade played an important role in the food industry. In this work, hyperspectral technology was used to detect five types of wheat flour. An analysis model was established based on the reflectance of samples at 968 ∼ 2576 nm. Moreover, multivariate scattering correction (MSC), standard normalized variate (SNV), and Savitzky-Golay (S-G) convolution smoothing were used for preprocessing, which was employed to reduce the influence of noise in the original spectrum. In order to simplify the model, competing adaptive reweighted sampling (CARS), successive projection algorithm (SPA), uninformative variable elimination (UVE) and the UVE-CARS algorithm were applied to extract feature wavelengths. Both partial least squares discriminant analysis (PLS-DA) model and support vector machine (SVM) model were established according to feature wavelengths. Furthermore, particle swarm optimization (PSO) algorithm was adopted to optimize the search of SVM model parameters, such as the penalty coefficient c and the regularization coefficient g. Experimental results suggested that the non-linear discriminant model for wheat flour grades was better than the linear discriminant model. It was considered that the MSC-UVE-CARS-PSO-SVM model achieved the best forecasting results for wheat flour grade discrimination, with 100% accuracy both in the calibration set and the validation set. It further shows that the classification of wheat flour grade can be effectively realized by using the hyperspectral and SVM discriminant analysis model, which proves the potential of hyperspectral reflectance technology in the qualitative analysis of wheat flour grade.

Protectin conjugates in tissue regeneration 1 alleviates sepsis-induced acute lung injury by inhibiting ferroptosis.

BACKGROUND: Acute lung injury (ALI) is a common and serious complication of sepsis with high mortality. Ferroptosis, categorized as programmed cell death, contributes to the development of lung injury. Protectin conjugates in tissue regeneration 1 (PCTR1) is an endogenous lipid mediator that exerts protective effects against multiorgan injury. However, the role of PCTR1 in the ferroptosis of sepsis-related ALI remains unknown. METHODS: A pulmonary epithelial cell line and a mouse model of ALI stimulated with lipopolysaccharide (LPS) were established in vitro and in vivo. Ferroptosis biomarkers, including ferrous (Fe2+), glutathione (GSH), malondialdehyde (MDA) and 4-Hydroxynonenal (4-HNE), were assessed by relevant assay kits. Glutathione peroxidase 4 (GPX4) and prostaglandin-endoperoxide synthase 2 (PTGS2) protein levels were determined by western blotting. Lipid peroxides were examined by fluorescence microscopy and flow cytometry. Cell viability was determined by a CCK-8 assay kit. The ultrastructure of mitochondria was observed with transmission electron microscopy. Morphology and inflammatory cytokine levels predicted the severity of lung injury. Afterward, related inhibitors were used to explore the potential mechanism by which PCTR1 regulates ferroptosis. RESULTS: PCTR1 treatment protected mice from LPS-induced lung injury, which was consistent with the effect of the ferroptosis inhibitor ferrostatin-1. PCTR1 treatment decreased Fe2+, PTGS2 and lipid reactive oxygen species (ROS) contents, increased GSH and GPX4 levels and ameliorated mitochondrial ultrastructural injury. Administration of LPS or the ferroptosis agonist RSL3 resulted in reduced cell viability, which was rescued by PCTR1. Mechanistically, inhibition of the PCTR1 receptor lipoxin A4 (ALX), protein kinase A (PKA) and transcription factor cAMP-response element binding protein (CREB) partly decreased PCTR1 upregulated GPX4 expression and a CREB inhibitor blocked the effects ofPCTR1 on ferroptosis inhibition and lung protection. CONCLUSION: This study suggests that PCTR1 suppresses LPS-induced ferroptosis via the ALX/PKA/CREB signaling pathway, which may offer promising therapeutic prospects in sepsis-related ALI.

Investigations into the antibacterial effects and potential mechanism of gambogic acid and neogambogic acid.

The growing threat of antibiotic-resistant bacterial infections to public health necessitates the development of novel antibacterial agents. Inhibiting bacterial cell wall synthesis has remained a key focus for antibiotic development. Our search for inhibitors of undecaprenyl diphosphate synthase (UPPS), an essential enzyme required for bacterial cell wall formation, revealed that two primary components of gamboge, gambogic acid (GA) and neogambogic acid (NGA), significantly inhibited the activity of Enterococcus faecalis UPPS (EfaUPPS) with the half maximal inhibitory concentrations (IC50) of 3.08 µM and 3.07 µM, respectively. In the in vitro antibacterial assay, both GA and NGA also exhibited inhibitory activities against E. faecalis with the minimal inhibitory concentrations (MICs) of 2 µg/mL. Using microscale thermophoresis, molecular docking, and enzymatic assays, we further confirmed that GA and NGA occupy the substrate binding pocket of EfaUPPS with micro-molar binding affinity, preventing the natural substrates farnesyl diphosphate (FPP) from entering. Mutagenesis analysis revealed that L91 and L146 are two key residues in the binding between GA/NGA and UPPS. Furthermore, we also demonstrated that GA and NGA can improve E. faecalis-induced undesirable inflammation in a mouse infection model. Taken together, our findings provide a basis for structural optimization of GA/NGA to develop improved antibiotic leads and enhance treatment success rates in clinical practice.