Search Results (323)

Lipopolysaccharides (LPS) from Gram-negative bacteria represent a significant challenge across various industries due to their prevalence and pathogenicity and the limitations of existing detection methods. Traditional approaches, such as the rabbit pyrogen test (RPT) and the Limulus Amebocyte Lysate (LAL) assay, have served as gold standards for endotoxin detection. However, these methods are constrained by high costs, lengthy processing times, environmental concerns, and the need for significant reagent volumes, which limit their scalability and application in resource-limited settings. In this study, we introduce an innovative microfluidic platform that integrates the LAL assay within microdroplets, addressing the critical limitations of traditional techniques. By leveraging the precise fluid control and reaction isolation offered by microdroplet technology, the system reduces reagent consumption, enhances sensitivity, and enables high-throughput analysis. Calibration tests were performed to validate the platform’s ability to detect LPS, using colorimetric measurements. Results demonstrated comparable or improved performance relative to traditional systems, achieving lower detection limits and greater accuracy. This work demonstrates a proof-of-concept miniaturisation of the pharmacopoeial LAL assay. The method yielded low intra-assay variability (σ ≈ 0.002 OD; CV ≈ 0.9% over n = 50 droplets per point) and a LOD estimated from calibration statistics after path-length normalisation. Broader adoption will require additional comparative validation and standardisation. This scalable, cost-effective, and environmentally sustainable approach offers a practical solution for endotoxin detection in clinical diagnostics, biopharmaceutical production, and environmental monitoring. The proposed technology paves the way for advanced LPS detection methods that meet stringent safety standards while improving efficiency, affordability, and adaptability for diverse applications. Full article

Foodborne illnesses remain a global challenge, requiring rapid and sensitive detection platforms. We developed a magnetosome-based electrochemical immunosensor for lipopolysaccharide (LPS) antigens from Escherichia coli and Salmonella typhimurium. Magnetosomes isolated from Magnetospirillum sp. RJS1 were characterized by HR-TEM and functionalized with antibodies (2 CFU mL⁻¹), with FTIR confirming successful conjugation. The antibody–magnetosome complexes were immobilized on a chitosan/glutaraldehyde-modified glassy carbon electrode. AFM revealed globular (200–700 nm) and island-like (1–3 µm) features after antigen binding. Electrochemical impedance spectroscopy showed stepwise increases in charge-transfer resistance upon electrode modification and antigen interaction. The sensor exhibited high sensitivity toward E. coli (3–7 CFU mL⁻¹) and Salmonella (3–8 CFU mL⁻¹), achieving an immune sensitivity of 36.24 Ω/CFU mL⁻¹ and a detection limit of 1 CFU mL⁻¹. These results demonstrate the potential of magnetosome-based immunosensors as portable, efficient platforms for the rapid detection of foodborne pathogens in real samples. Full article

Brucellosis, a zoonotic infection caused by the intracellular pathogen Brucella, leads to chronic multi-organ damage. Currently, rapid, accurate, and sensitive diagnostic technologies are crucial for the prevention and control of brucellosis. This study describes the development of a chemiluminescent immunoassay (Bru-CLIA) for sheep and bovine brucellosis antibody detection, utilizing Brucella abortus strain A19 lipopolysaccharide-coated magnetic particles (LPS-MPs) as the serum antigen and acridinium ester-labeled recombinant streptococcal protein G (AE-SPG) for signal generation. After optimizing the assay’s parameters, the Bru-CLIA demonstrated a sensitivity of approximately 1 IU/mL and 2 IU/mL for detecting sheep and bovine brucellosis, respectively. No cross-reactivity was observed with sera from animals immunized with Escherichia coli O157:H7, Mycobacterium tuberculosis, Vibrio cholerae, Legionella, Salmonella, Foot and Mouth Disease virus types O and A, Bovine viral diarrhea virus, Sheep contagious pleuropneumonia, Goat pox virus, or Peste des Petits Ruminants virus, indicating strong specificity. The testing of 81 sheep serum samples and 96 bovine serum samples revealed that Bru-CLIA showed 87.65% and 93.75% concordance with the ID-VET commercial kits for sheep and bovine brucellosis detection, respectively. These results demonstrate that Bru-CLIA offers high specificity, sensitivity, repeatability, and reliability, making it a viable rapid diagnostic tool for the epidemiological surveillance of brucellosis. Full article

Sepsis causes profound microcirculatory dysfunction, where heterogeneous capillary perfusion and abnormal vasomotion contribute to tissue hypoxia and organ failure. Sublingual videomicroscopy is established in large animals and humans to monitor these alterations, but this approach has not been applied in murine models. We developed a method to assess sublingual perfusion and vasomotion in mice using sidestream dark field (SDF) videomicroscopy. Male C57BL/6 mice were anesthetized, and sublingual vessels were imaged for 90 min. Perfusion and vasomotion parameters were assessed, and a Fast Fourier Transform was performed on vasomotion data to characterize the frequency components of rhythmic microvessel diameter changes. Another group of animals was administered lipopolysaccharide (LPS) intraperitoneally as a model of systemic inflammation in sepsis. LPS-treated mice exhibited a significant decline in the proportion of perfused vessels at 90 min and in the microvascular flow index. Very low-frequency vasomotion (0.005–0.15 Hz) declined in controls but was preserved during endotoxemia, suggesting an active microvascular tone response to inflammatory stress. This study establishes the first murine protocol for sublingual SDF imaging, allowing early detection of perfusion deficits and vasomotor changes in experimental sepsis. The minimal-invasive approach offers a translational platform for mechanistic and therapeutic studies in sepsis. Full article

Nanoporous gold nanoparticles (np-AuNPs) combine inertness, a nanoscale structure, and a porous framework with high surface area, conductivity, and biocompatibility, making them ideal for biosensing, catalysis, fuel cells, and drug delivery. Their open pore structure and low-coordinated atoms enhance biomolecule capture and mass transfer, while their tunable size, pore volume, and ease of surface modification make them promising biosensor transducers. However, synthesizing colloidal np-AuNPs in a simple way with controllable size and scalability remains challenging. The existing approaches mostly rely on specialized equipment, complex setups, and expert knowledge, while still facing challenges in terms of scalability. In this study, we present a simple, seedless, wet-chemical synthesis of colloidal np-AuNPs via the co-reduction of Au/Ag alloys followed by dealloying. By adjusting the Au:Ag ratio, we produced np-AuNPs sized ~120–530 nm, which were immobilized on electrodes for detecting lipopolysaccharide (LPS), a toxic component of Gram-negative bacterial membranes. The LPS biosensor exhibited excellent sensitivity towards detecting wild-type LPS, with a low limit of detection (LOD) of 0.1244 ng/L. This work demonstrates the effective synthesis and application of np-AuNPs in LPS biosensing. Full article

Propolis contains abundant flavonoid and phenolic compounds, whose composition and concentration vary significantly in different geographical origins, thereby affecting its bioactive properties including anti-inflammatory, antioxidant, and antimicrobial activities. In this study, the flavonoid and phenolic content in the ethanol extract of propolis (EEP) from Henan (HN) and Shandong (SD) provinces was quantitatively analyzed, and the results showed that concentrations of both bioactive components in HN were slightly higher than those in SD. The non-targeted metabolomics technology was further employed to analyze the components of EEP, and a total of 10683 metabolites were detected. In the comparison between the samples of HN and SD, there were a total of 1436 differential metabolites, with 553 decreased and 883 increased in the HN sample. Among them, there were 205 differential metabolites related to flavonoids and phenols, with 108 decreased and 97 increased in the HN sample. However, a greater number of carboxylic acids and derivatives, fatty derivatives and organooxygen metabolites were found at higher relative levels in the HN sample. As a result, the EEP of the HN sample was selected to investigate its inhibitory effect on inflammation in lipopolysaccharide (LPS)-induced BV2 microglia cells. The results showed that LPS promoted the M1 polarization of BV2 microglia. However, treatment with EEP at concentrations of 10 µg/mL, 5 µg/mL, and 2.5 µg/mL could partially restore the cell morphology to its non-activated state. Meanwhile, LPS stimulation increased the protein levels of IL-1β, IL-6 and TNF-α significantly, as well as the relative gene expression levels of IL-1β, IL-6, TNF-α, COX-2, iNOS and TLR4. After treatment with the EEP, the expression levels of these three proteins and six genes were significantly decreased. These findings revealed that EEP effectively inhibited the M1 polarization of LPS-induced BV2 cells and decreased the expression of inflammatory factors, indicating its potential as a therapeutic agent for neuroinflammation. Full article

Due to their evolutionary divergence from mammals, zebrafish (Zf, Danio rerio), which are frequently employed in biomedical research, provide a distinctive viewpoint on innate immune systems. The Toll-like receptor 4/myeloid differentiation factor 2/cluster of differentiation 14 (TLR4/MD-2/CD14) complex in mammals detects lipopolysaccharide (LPS), a crucial component of Gram-negative bacteria, and it causes potent inflammatory reactions through a Toll/interleukin-1 receptor domain-containing adapter-inducing interferon-β (TRIF)-dependent and myeloid differentiation primary response 88 (MyD88)-dependent pathways. However, key components of this system, such as a responsive TLR4 axis and a functional CD14 ortholog, are absent in Zf. The Zf species nevertheless reacts to LPS, which leads to research into other recognition systems. This review looks at a number of TLR4-independent processes in Zf, such as scavenger receptors (SRs) including scavenger receptor class B type 1 (SR-BI) and cluster of differentiation 36 (CD36), nucleotide-binding oligomerization domain-containing protein 1 (NOD1)-dependent cytosolic sensing, peptidoglycan recognition proteins (PGRPs), Complement Component 3 (C3), and caspase-1-like protein 2 (Caspy2)-mediated inflammasome activation. An alternative and flexible immune system that makes up for the lack of canonical TLR4 signaling is revealed by these mechanisms. Additionally, the discovery of lymphocyte antigen 96 (ly96), an ortholog of MD-2 found in Zf, suggests evolutionary similarity; however, as it is only functional in artificial systems, it demonstrates minimal overlap with mammalian MD-2 activity. Knowing these pathways provides important information for studying inflammation, infection, and immunological modulation in vertebrates using Zf as a model. It also clarifies the evolutionary flexibility of innate immune recognition. Full article

The aim of this study was to refine the lipopolysaccharide (LPS)-induced synovitis model in normal carpal joints of Thoroughbred horses by comparing two low LPS doses. A further aim was to investigate the relationship between the induced synovitis and lameness. The study design consisted of two phases using nine horses with a unilateral crossover design and a within-animal saline control. Synoviocentesis was performed at post-injection hour (PIH) 0, 8, 24, 72 and 168, allowing for synovial fluid cytology and biomarker analysis. Objective gait and thermographic analysis were used to objectively measure clinical effects. The results demonstrate that injection of either a 0.125 ng or 0.25 ng dose of LPS induces a comparable degree of synovitis in terms of TP, WBC, PGE₂ and MMP activity at peak values. Statistically significant changes in baseline lameness values were not detected with the 0.125 ng dose, a novel and valuable finding suggesting a comparable degree of synovitis is achieved without significant lameness. All measured parameters had returned to baseline by PIH 168. In conclusion, the findings of this study confirm that this LPS model produces a consistent and reliable synovitis at 0.25 ng and 0.125 ng doses. The reduction in lameness evident at the 0.125 ng dose offers enhanced animal welfare while delivering measurable synovitis. The authors believe that a further reduction in the LPS dose is possible with continued development of a repeated low-dose/slow-release model to better mimic clinical disease. Full article

Dysregulated inflammatory processes contribute to depression, and gene–environment interactions may influence an individual’s risk and resilience. Reduced brain-derived neurotrophic factor (BDNF) expression increases susceptibility for developing depressive symptoms, and the Val66Met (rs6265) single-nucleotide polymorphism (SNP) on the BDNF gene is linked to mood disorders. However, whether Val66Met confers increased vulnerability to inflammation-induced depressive tendencies is unknown. Here, we tested the hypothesis that the Val66Met SNP increases vulnerability to inflammation-induced depressive symptoms in a mouse model of lipopolysaccharide (LPS)-induced depression-like behavior. Behavior and neuroinflammation, following a 24 h LPS challenge, were measured in mice expressing the human BDNF Val66Met gene variant or Val66Val littermates (control). The Val66Met genotype did not affect the peripheral inflammatory response, acute neuroinflammation, or the acute sickness behavior response. Val66Met mice exhibited anhedonia-like behavioral responses following LPS challenge, and we found increased mRNA expression of IL-1β and TNFα in the cerebrum compared to controls. The mRNA expression of IL-1β and TNFα in the hippocampus and the nucleus accumbens of Val66Met mice was increased following LPS, and a significant genotype × LPS interaction was detected for CD68 expression in the nucleus accumbens. In summary, these data suggest that immune activation in Val66Met mice increased susceptibility to anhedonic behavior and dysregulated negative regulation of inflammation. Full article

Introduction: Sepsis-associated encephalopathy (SAE) is an acute brain dysfunction secondary to systemic infection, occurring without direct central nervous system involvement. Despite its clinical relevance, reliable biomarkers for diagnosing SAE and assessing its severity remain limited. This study aimed to evaluate the feasibility of amide proton transfer-weighted (APTw) chemical exchange saturation transfer (CEST) MRI as a non-invasive molecular imaging technique for detecting metabolic alterations related to neuroinflammation in SAE. Using a lipopolysaccharide (LPS)-induced rat model, we focused on hippocampal changes associated with neuronal inflammation. Materials and Methods: Twenty-one Sprague–Dawley rats (8 weeks old, male) were divided into three groups: control (CTRL, n = 7), LPS-induced sepsis at 5 mg/kg (LPS05, n = 7), and 10 mg/kg (LPS10, n = 7). Sepsis was induced via a single intraperitoneal injection of LPS. APTw imaging was performed using a 7 T preclinical MRI system, and signal quantification in the hippocampus was conducted using the magnetization transfer ratio asymmetry analysis. Results and Discussion: APTw imaging at 7 T demonstrated significantly elevated hippocampal APTw signals in SAE model rats (LPS05 and LPS10) compared to the control (CTRL) group: CTRL (−1.940 ± 0.207%) vs. LPS05 (−0.472 ± 0.485%) (p < 0.001) and CTRL vs. LPS10 (−0.491 ± 0.279%) (p < 0.001). However, no statistically significant difference was observed between the LPS05 and LPS10 groups (p = 0.994). These results suggest that APTw imaging can effectively detect neuroinflammation-related metabolic alterations in the hippocampus. Conclusion: Our findings support the feasibility of APTw CEST imaging as a non-invasive molecular MRI technique for SAE, with potential applications in diagnosis, disease monitoring, and therapeutic evaluation. Full article

Prion diseases are classically attributed to the accumulation of protease-resistant prion protein (PrP^Sc); however, recent evidence suggests that alternative misfolded prion conformers and systemic inflammatory factors may also contribute to neurodegeneration. This study investigated whether recombinant moPrP^Res, generated by incubating wild-type mouse PrP^C with bacterial lipopolysaccharide (LPS), can induce prion-like disease in FVB/N female mice, whether LPS alone causes neurodegeneration, and how LPS modulates disease progression in mice inoculated with the Rocky Mountain Laboratory (RML) strain of prions. Wild-type female FVB/N mice were randomized into six subcutaneous treatment groups: saline, LPS, moPrP^Res, moPrP^Res + LPS, RML, and RML + LPS. Animals were monitored longitudinally for survival, body weight, and clinical signs. Brain tissues were analyzed histologically and immunohistochemically for vacuolar degeneration, PrP^Sc accumulation, reactive astrogliosis, and amyloid-β plaque deposition. Recombinant moPrP^Res induced a progressive spongiform encephalopathy characterized by widespread vacuolation and astrogliosis, yet with no detectable PrP^Sc by Western blot or immunohistochemistry. LPS alone triggered a distinct neurodegenerative phenotype, including cerebellar amyloid-β plaque accumulation and terminal-stage spongiosis, with approximately 40% mortality by the end of the study. Co-administration of moPrP^Res and LPS resulted in variable regional pathology and intermediate survival (50% at 750 days post-inoculation). Interestingly, RML + LPS co-treatment led to earlier clinical onset and mortality compared to RML alone; however, vacuolation levels were not significantly elevated and, in some brain regions, were reduced. These results demonstrate that chronic endotoxemia and non-infectious misfolded PrP conformers can independently or synergistically induce key neuropathological hallmarks of prion disease, even in the absence of classical PrP^Sc. Targeting inflammatory signaling and toxic prion intermediates may offer novel therapeutic strategies for prion and prion-like disorders. Full article

Background/Objectives: Acute lung injury (ALI) is an inflammatory condition characterized by tissue barrier damage, which leads to vascular leakage, pulmonary edema, and compromised gas exchange. Lipopolysaccharides (LPS) are a component of Gram-negative bacteria, which trigger inflammation by Toll-like receptor 4 (TLR4) activation. Herein, we investigated the possibility that Pasireotide (PAS) exerts protective effects in an experimental model of ALI. Methods: C57BL/6 male mice received an intratracheal injection of saline or LPS, followed by PAS or vehicle treatment. Bronchoalveolar lavage fluid (BALF) was collected via tracheal catheterization, and Western blot analysis was used to detect protein expression variations. Results: Our results suggest that PAS treatment alleviates LPS-induced mouse lung injury and inflammation. JAK/STAT and MAPK activation levels in the inflamed lungs were suppressed due to PAS treatment, as well as BALF protein concentration. Additionally, PAS counteracted LPS-induced Grp94 protein reduction, suggesting the involvement of ATF6 in PAS-triggered barrier-protective effects. Grp94 is a downstream ATF6 target. Conclusions: Our data demonstrate that PAS protects mouse lungs against LPS in an experimental model of ALI. Full article

Background/Objectives: In preclinical research of airway inflammation, the endotoxin (lipopolysaccharide: LPS)–induced acute interstitial pneumonitis is the most commonly used mechanism model. However, studies apply different LPS serotypes, doses, administration routes, and reference compounds, making result interpretation challenging and drawing conclusions difficult. Therefore, here we aimed to optimize, characterize, and validate this model with dexamethasone in mice. Methods: Pneumonitis was induced by intratracheal LPS (0.25, 1, 2.5, 5 mg/kg; E. coli O111:B4) in C57BL/6J and NMRI mice; controls received phosphate-buffered saline (PBS). Dexamethasone (5 mg/kg i.p.) was used as a positive control. Respiratory functions were measured by restrained plethysmography 24 h after induction, and core body temperature was monitored. Lungs were excised and weighed, and then myeloperoxidase (MPO) activity and histopathological analysis were performed to assess pulmonary inflammation. Results: LPS-induced significant body weight loss, perivascular pulmonary edema, MPO activity increase, neutrophil infiltration, and respiratory function impairment in a dose-independent manner. However, LPS-induced hypothermia dynamics and duration were dose-dependent. The inhibitory effects of the reference compound dexamethasone were only detectable in the case of the 0.25 mg/kg LPS dose on most inflammatory parameters. These results did not differ substantially between C57BL/6J and NMRI mouse strains. Conclusions: Very low doses of LPS induce characteristic functional and morphological inflammatory alterations in the lung, which do not worsen in response to even 20 times higher doses. Since the effect of pharmacological interventions is likely to be detectable in the case of the 0.25 mg/kg LPS dose, we suggest this protocol for testing novel anti-inflammatory agents. Full article

Background: Autism spectrum disorder (ASD) is increasingly linked to systemic metabolic dysfunction, potentially influenced by gut–brain axis dysregulation, but the underlying mechanisms remain unclear. Methods: We developed Personalized Metabolic Margin Mapping (PM³), a computational systems biology framework, to analyze RNA-seq data from 12 ASD and 12 control postmortem brain samples. The model focused on 158 curated metabolic genes selected for their roles in redox balance, mitochondrial function, neurodevelopment, and gut–brain interactions. Results: Using unsupervised machine learning (Isolation Forest) to detect outlier expression patterns, Euclidean distance, and percent expression difference metrics, PM³ revealed a consistent downregulation of glycolysis (e.g., −5.4% in PFKM) and mitochondrial enzymes (e.g., −12% in SUCLA2). By incorporating cofactor dependency and subcellular localization, PM³ identified a coordinated suppression of multivitamin transporters (e.g., −4.5% in SLC5A6, −3.5% in SLC19A2), potentially limiting cofactor availability and compounding energy deficits in ASD brains. Conclusions: These findings suggest a convergent metabolic dysregulation signature in ASD; wherein the subtle suppression of cofactor-dependent pathways may impair energy metabolism and neurodevelopment. We propose that chronic microbial lipopolysaccharide (LPS) exposure in ASD suppresses vitamin transporter function, initiating mitochondrial dysfunction and transcriptomic reprogramming. Validation in LPS-exposed systems using integrated transcriptomic–metabolomic analysis is warranted. Full article

Although sepsis-induced acute kidney injury (AKI) is associated with significant morbidity and mortality, its treatment remains unresolved. Oxidative stress and inflammation are key elements in the pathomechanism of AKI. Therefore, in the present study, we investigated the role of DJ-1 protein, known for its antioxidant and anti-inflammatory properties in an animal model of lipopolysaccharide (LPS)-induced AKI. The presence of DJ-1 was detected by immunofluorescence staining in mice kidney samples, human embryonic kidney cells (HEK-293), and peripheral blood mononuclear cells (PBMCs). To investigate DJ-1 functions, Compound-23, a specific DJ-1-binding and preserving compound (CAS: 724737-74-0), was used in vitro and in vivo. Compound-23 reduced the H₂O₂-induced reactive oxygen species (ROS) production of the HEK-293 cells, and their LPS- or H₂O₂-induced death, as well. In accordance, Compound-23 decreased the mRNA expression of the oxidative stress markers NAD(P)H quinone dehydrogenase 1 (NQO1) and glutamate-cysteine ligase (GCLC) in the LPS-treated, and NQO1 in the H₂O₂-treated cells. Moreover, Compound-23 reduced the H₂O₂- and LPS-induced mRNA expression of inflammatory cytokine interleukin 6 (IL6) in both HEK-293 and PBMCs. Using the mice model of LPS-induced AKI, we demonstrated that Compound-23 treatment improved the renal functions of the mice. In addition, Compound-23 decreased the renal mRNA expression of kidney injury molecule 1 (Kim1), neutrophil gelatinase-associated lipocalin (Ngal), Nqo1, Gclc, and Il6 in the LPS-treated mice. Our study revealed that compounds protecting DJ-1 functions may protect the kidney from LPS-induced damage, suggesting that DJ-1 could be a potential drug target for sepsis-induced AKI therapy. Full article