Concentrations Of Lipopolysaccharide Research Articles

The Effect of Lipopolysaccharides from Salmonella enterica on the Size, Density, and Compressibility of Phospholipid Vesicles

The properties of the large unilamellar vesicles (LUVs) from 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC), modified by lipopolysaccharides (LPS) from Salmonella enterica sv. Enteritidis, which mimics Gram-negative bacteria, were studied by various physical methods. LPS, in the range of 0/20/50 % w/w relative to the lipid, had a regulatory role in the structure of the LUVs toward the lower size, low polydispersity, and over-a-month size stability due to the lower negative zeta potential. The addition of LPS resulted in increased density, which determined the ultrasound velocity and the specific adiabatic compressibility. In a 0.5/1/2 mg/mL concentration range, the total lipid content did not significantly affect the size of LUVs and influenced the density-related attributes similarly to the LPS content. A positive correlation was found between temperature and vesicle size, and a negative correlation was found between temperature and density and compressibility—except for the anomaly behavior at 25 °C, around the melting point of DMPC.

S-amlodipine induces liver inflammation and dysfunction through the alteration of intestinal microbiome in a rat model

ABSTRACT S-amlodipine, a commonly prescribed antihypertensive agent, is widely used in clinical settings to treat hypertension. However, the potential adverse effects of long-term S-amlodipine treatment on the liver remain uncertain, given the cautionary recommendations from clinicians regarding its administration in individuals with impaired liver function. To address this, we conducted a study using an eight-week-old male rat model and administered a daily dose of 0.6 ~ 5 mg/kg of S-amlodipine for 7 weeks. Our findings demonstrated that 1.2 ~ 5 mg/kg of S-amlodipine treatment induced liver inflammation and associated dysfunction in rats, further in vitro experiments revealed that the observed liver inflammation and dysfunction were not attributable to direct effects of S-amlodipine on the liver. Metagenome sequencing analysis revealed that S-amlodipine treatment led to alterations in the gut microbiome of rats, with the bloom of E. coli (4.5 ~ 6.6-fold increase) and a decrease in A. muciniphila (1,613.4 ~ 2,000-fold decrease) and B. uniformis (20.6 ~ 202.7-fold decrease), subsequently causing an increase in the gut bacterial lipopolysaccharide (LPS) content (1.4 ~ 1.5-fold increase in feces). S-amlodipine treatment also induced damage to the intestinal barrier and increased intestinal permeability, as confirmed by elevated levels of fecal albumin; furthermore, the flux of gut bacterial LPS into the bloodstream through the portal vein resulted in an increase in serum LPS content (3.3 ~ 4-fold increase). LPS induces liver inflammation and subsequent dysfunction in rats by activating the TLR4 pathway. This study is the first to show that S-amlodipine induces liver inflammation and dysfunction by perturbing the rat gut microbiome. These results indicate the adverse effects of S-amlodipine on the liver and provide a rich understanding of the safety of long-term S-amlodipine administration.

Akkermansia muciniphila- and Pathogenic Bacteria-Derived Endotoxins Differently Regulate Human Dendritic Cell Generation and γδ T Lymphocyte Activation.

Lipopolysaccharide (LPS) is a potent endotoxin released at high concentrations in acute infections, causing massive host inflammatory response. Accumulating evidence indicates that dysbiosis-associated chronic low levels of circulating LPS can sustain a prolonged sterile low-grade inflammation that increases the risk of several non-communicable diseases. Interventions aimed at increasing the abundance of beneficial/probiotic bacteria, including Akkermansia muciniphila, result in reduced inflammation, favoring metabolic and immune health. Immunosuppression is a common feature in conditions of chronic inflammation, and dendritic cells (DCs) represent key targets given their ability to shift the balance toward immunity or tolerance. In this study, the effects of low concentrations of LPS from pathogenic (Escherichia coli and Salmonella enterica) and probiotic (Akkermansia muciniphila) bacterial species on human DC generation and functions were compared. We report that monocyte precursor priming with Escherichia coli and Salmonella enterica LPS forces the differentiation of PD-L1-expressing DCs, releasing high levels of IL-6 and IL-10, and impairs their capacity to drive full TCR-Vδ2 T cell activation. Conversely, comparable concentrations of Akkermansia muciniphila promoted the generation of DCs with preserved activating potential and immunostimulatory properties. These results shed light on potential mechanisms underlying the impact of low endotoxemia on disease risk and pathogenesis, and increase our understanding of the immunomodulatory effects of Akkermansia muciniphila.

A126: High-Intensity Interval Training and Medium-Intensity Continuous May Affect Cognitive Function Through the Microbiota-Gut-Brain Axis

Background/Purpose: The gut-brain axis is the communication mechanism between the gut and the central nervous system, and the intestinal flora and lipopolysaccharide (LPS) play a crucial role in this mechanism. Exercise regulates the gut microbiota composition and metabolite (i.e., LPS) production. We aimed to investigate the effects of moderate-intensity continuous training and high-intensity interval training (HIIT) on cognitive function in C57BL/6J mice through gut-brain axis regulation of gut microbiota composition and LPS displacement. Method: C57BL/6J male mice were randomly assigned into a quiet group (WTC), a high-intensity interval training group (WTH) and a moderate-intensity continuous training group (WTE). After 12 weeks of exercise intervention, the cognitive function of the brain and the mRNA levels of related inflammatory factors were detected, and RNA sequencing, Golgi staining, intestinal microbial 16s rDNA sequencing and ELISA Assay were performed. All information was analyzed with IBM SPSS Statistics 26 and GraphPad Prism 9.0. Mean ± standard error of the mean (SEM) was used to represent MWM findings. Standard deviation ± mean (mean ± SD) is used to express other data. With P < 0.05 denoting statistical significance, post hoc multiple comparisons were performed using the least significant difference method and one-way ANOVA tests. Results: The results showed that MICT increased ZO-1 mRNA and Syn mRNA expression (p < 0.05), and increased dendritic spine density in the brain of mice (p < 0.05). However, HIIT increased the LPS content (p < 0.05), the expression of inflammation-related genes (CD86 mRNA, TLR4 mRNA and HK2 mRNA, etc, p < 0.05), and the ratio of Firmicutes/Bacteroidetes at the phylum level and decreased the density of dendritic spines in the blood and brain of C57BL/6J mice (p < 0.05). Conclusion: In conclusion, HIIT and MICT affect brain cognitive function by regulating the composition of gut microbiota and its metabolite LPS through the gut microbiota-gut-brain axis, and HIIT was suspected to have certain risks: It can induce "intestinal leakage" by regulating intestinal permeability related microbiota, resulting in excessive LPS into the blood and brain, and activate M1 microglia in the brain, leading to reduced dendritic spine density and affecting cognitive function.

Exosomal miR-155-5p Facilitates Lipopolysaccharide Transport and Foam Cell Formation: A Novel Link Between Periodontitis and Atherosclerosis.

To investigate the role of lipopolysaccharide (LPS) from Porphyromonas gingivalis and miR-155-5p-enriched exosomes in the formation of foam cells and the occurrence of carotid atherosclerosis (CAS). The CAS tissue samples and plasma from the healthy control group or patients undergoing periodontitis without CAS and with CAS were collected at the Xuanwu Hospital, Capital Medical University. The expression level of miR-155-5p was evaluated by immunofluorescent analysis and qRT-PCR. Oil red O staining and lipid accumulation assays were performed to explore the effects of LPS and miR-155-5p on mouse macrophage Raw264.7 and human monocytes THP-1. The expression levels of lipid-regulated genes were detected by qRT-PCR. Dual-luciferase reporter gene assay and DET1 overexpressed or inhibited Raw264.7 cells were used to verify the target gene of exosomal miR-155-5p. ApoE-/- mice were used to confirm the auxo-action of atherosclerosis from exosomal miR-155-5p invivo, and LAL assay was used to detect the LPS content. miR-155-5p was higher in patients with periodontitis and CAS plasma exosomes than those in patients without CAS. The expression of miR-155-5p was significantly increased in CAS tissues compared with Normal tissues, and the expression level of miR-155-5p was associated with lipid-regulated genes in CAS tissues. MiR-155-5p-enriched exosomes accelerated lipid accumulation in macrophage-like cells and promoted the activity of lipid-accumulation genes by targeting DET1. In ApoE-/- mice, circulating miR-155-5p-enriched exosomes captured LPS, and the LPS-laden exosomes conferred plasma access for LPS, triggering the formation of foam cells and the occurrence of CAS. miR-155-5p enriched exosomes capture and escort LPS to the atherosclerotic sites, licensing the formation of foam cells and thus promoting CAS.

Dietary Bovine Lactoferrin Reduces the Deleterious Effects of Lipopolysaccharide Injection on Mice Intestine.

Injection of lipopolysaccharides (LPS) in experimental models induces a systemic inflammatory response that is associated with deleterious effects on intestinal morphology and physiology. In this study, we have studied in female mice the effects of dietary supplementation with bovine lactoferrin (bLF) given before intraperitoneal injection of LPS on jejunum and colon. The first study evaluated the efficiency of different bLF and LPS concentrations to determine the optimal experimental conditions. For the second study mice were fed with 1% bLF before the LPS challenge (3 mg/kg body weight). Plasmatic markers of inflammation, intestinal morphology, permeability, and expression of genes related to epithelial differentiation, epithelial barrier function and intestinal inflammation in both small intestine and colon were evaluated. bLF ingestion before the LPS challenge reduced the TNF-α circulating concentration, compared to control animals. This decrease in plasma TNF-α was correlated with improved intestinal permeability. The morphology of jejunal epithelium, which was affected by LPS challenge, was partly maintained by bLF. Measurement of the expression of genes encoding proteins involved in epithelial differentiation, intestinal inflammation, and epithelial barrier function suggests an overall protective effect of bLF against the adverse effects of LPS in the jejunum. In the colon, the effects of bLF ingestion on the subsequent LPS challenge, although protective, remain different when compared with those observed on jejunum. Taken together, our data indicate that bLF dietary supplementation does have a protective effect on the deleterious intestinal alterations induced by LPS systemic inflammation.

The Synergic Immunomodulatory Effect of Vitamin D and Chickpea Protein Hydrolysate in THP-1 Cells: An In Vitro Approach.

Vitamin D (VD), a crucial micronutrient, regulates bone health and immune responses. Recent studies suggest that VD may confer protective effects against chronic inflammatory diseases. Additionally, plant-based peptides can show biological activities. Furthermore, the supplementation of protein hydrolysates with VD could potentially enhance the bioactivity of peptides, leading to synergistic effects. In this study, THP-1 cells were exposed to low concentrations of Lipopolysaccharide (LPS) to induce inflammation, followed by treatment with vitamin D at different concentrations (10, 25, or 50 nM) or a chickpea protein hydrolysate ("H30BIO") supplemented with VD. The cytotoxicity of VD was evaluated using viability assay to confirm its safety. The cytokine secretion of TNF-α, IL-1β, and IL6 was assessed in the cell supernatant, and the gene expression of TNF-α, IL-1β, IL6, IL8, CASP-1, COX2, NRF2, NF-ĸB, NLRP3, CCL2, CCR2, IP10, IL10, and RANTES was quantified by qRT-PCR. Treatment with VD alone significantly decreased the expression of the pro-inflammatory genes TNF-α and IL6, as well as their corresponding cytokine levels in the supernatants. While IL-1β gene expression remained unchanged, a reduction in its cytokine release was observed upon VD treatment. No dose-dependent effects were observed. Interestingly, the combination of VD with H30BIO led to an increase in TNF-α expression and secretion in contrast with the LPS control, coupled with a decrease in IL-1β levels. Additionally, genes such as IP10, NF-κB, CCL2, COX2, NRF2, and CASP-1 exhibited notable modulation, suggesting that the combination treatment primarily downregulates NF-κB-related gene activity. This study demonstrates a synergistic interaction between VD and H30BIO, suggesting that this combination may enhance pathways involving TNF-α, potentially aiding in the resolution and modulation of inflammation through adaptive processes. These findings open new avenues for research into the therapeutic applications of enriched protein hydrolysates with VD to manage low-grade inflammatory-related conditions.

Co-exposure of ferruginous components of subway particles with lipopolysaccharide impairs vascular function: A comparative study with ambient particulate matter

Several empirical studies have linked subway and ambient particle exposure to toxicity, pro-inflammatory responses, and vascular dysfunction. However, the health effects of pollutants generated from varying sources, particularly when combined with lipopolysaccharide (LPS), are still unexplored. Therefore, the aim of this study was to investigate the characteristic health effects of iron oxide particles (the main components of subway particles) in comparison with urban aerosols (UA) and vehicle exhaust particles (VEP), alone and in combination with LPS. This study revealed that iron oxides caused a more significant reduction in human umbilical vein endothelial cell viability, increased lactate dehydrogenase release, and decreased the production of plasminogen activator inhibitor-1, a fibrinolytic modulator, and endothelin-1, a vasoconstrictor, compared to those by VEP and UA at marginally toxic and toxic concentrations. While VEP and UA induced an increase in interleukin (IL)-6 production, iron oxides, particularly Fe3O4, increased IL-8 production at slightly toxic and non-cytotoxic concentrations. In addition, co-exposure of all particles and LPS at non-cytotoxic concentrations promoted pro-inflammatory cytokine (IL-6 and IL-8) production relative to exposure to the particles alone. Interestingly, the tendency towards either coagulation or fibrinolytic conditions was dependent on the concentration of exposed particles at the same LPS concentration. Furthermore, increases in inflammation, neutrophil and lymphocyte recruitment around blood vessels, and edema were observed in murine lungs exposed to a combination of iron oxides and LPS compared to those in mice exposed to iron oxide alone. Thus, iron oxide-rich subway particulate poses more health risks than outdoor ambient particles since they can significantly impair endothelial function, particularly through gross cellular and vascular homeostatic protein damage, and induce exacerbated inflammatory responses during co-exposure. These findings provide novel empirical evidence for epidemiological studies seeking mechanisms responsible for the observed health impact of transport- and occupational-related exposures on vascular dysfunction.

The links between neuroinflammation, brain structure and depressive disorder: A cross-sectional study protocol.

It is known that symptoms of major depressive disorder (MDD) are associated with neurodegeneration, that lipopolysaccharide (LPS) can induce symptoms of MDD, and that blood LPS levels are elevated in neurodegeneration. However, it is not known whether blood LPS and cytokine levels correlate with MDD, cognition and brain structure, and this is tested in this study. This cross-sectional study includes individuals with MDD (n = 100) and a control group of individuals with no one-year history of a mental disorder (n = 50). A comprehensive evaluation is performed, including the collection of basic sociodemographic information, data on smoking status, body mass index, course of MDD, past treatment, comorbid diseases, and current use of medications. Diagnosis of MDD is performed according to the WHO's [2019] International Classification of Diseases and related health problems by psychiatrist and severity of MDD is evaluated using the Montgomery-Åsberg Depression Scale. The Cambridge Neuropsychological Test Automated Battery is used to evaluate cognitive functioning. Venous blood samples are taken to measure genetic and inflammatory markers, and multiparametric brain magnetic resonance imaging is performed to evaluate for blood-brain barrier permeability, structural and neurometabolic brain changes. Descriptive and inferential statistics, including linear and logistic regression, will be used to analyse relationships between blood plasma LPS and inflammatory cytokine concentrations in MDD patients and controls. The proposed sample sizes are suitable for identifying significant differences between the groups, according to a power analysis. Trial registration: Clinicaltrials.gov NCT06203015.

Oxidative stress model of lipopolysaccharide combined with thrombin inducing in broiler chicks.

Lipopolysaccharides (LPS) are commonly used to construct inflammation models. However, poultry have a certain degree of tolerance to LPS due to the lack of thrombin XI and XII in their bodies. Thrombin activation produces clotting factors that can cleave prothrombin to form thrombin. The purpose of this study was to construct a chick oxidative stress model used different concentrations of LPS combined with thrombin in order to screen for the optimal concentration for constructing the oxidative stress model, and to explore the effects of this stimulus on various indicators of chicks. Eighty-one young chicks (4-days-old) were randomly divided into three groups with 27 chicks per group where each group contained 3 replicates with 9 birds each: a control group (physiological saline), a low-dose group (LPS 5 mg/kg thrombin 150 U/kg), and a high-dose group (LPS 10 mg/kg thrombin 300 U/kg). The results indicated that compared with the control group, the low-dose group and the high-dose group significantly increased the content of Malondialdehyde (MDA) in serum and reduced the content of T-AOC, GSH-PX and SOD, respectively. Meanwhile, the levels of NO and inflammatory factors IL-1β, IL-6 and TNF-α TNF-α in the liver were significantly increased in the low-dose and high-dose groups compared with the control group, respectively. Liver and thymus tissue sections from the low- and high-dose groups showed hemorrhage, hemolysis, and a small amount of exudation. In terms of inflammatory effect, the serum MDA content and the levels of NO, IL-1β, IL-6 and TNF-α factors in the liver were significantly increased in the low-dose group compared with the high-dose group. On histopathological observation, tissue damage was more pronounced in the low-dose group than in the high-dose group. In conclusion, LPS combined with thrombin could induce oxidative stress in chicks and the pathological changes of the low-dose effect are more pronounced.

Influence of neodymium-doped yttrium aluminum garnet laser exposure time on cytokine secretion in lipopolysaccharide-challenged rat peripheral blood mononuclear cells

Multiple investigators have suggested that infrared laser energy facilitates hard and soft tissue wound healing through various mechanisms, including the suppression of inflammation. This study investigated the influence of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser exposure time on pro-inflammatory cytokine/chemokine concentrations in lipopolysaccharide (LPS)-stimulated rat peripheral blood mononuclear cells (PBMCs). Cultured rat PBMCs were stimulated with various LPS concentrations (0, 10, 100, or 1000 ng/mL) and treated with Nd:YAG laser irradiation for 0 (control), 30, 45, or 60 s. For these experiments, the average power, pulse duration, and repetition rate remained constant at 5 W, 100 μs, and 20 Hz, respectively. Luminex magnetic microsphere immunoassays were used to compare the secretion of 27 inflammatory mediators from LPS-stimulated PBMCs in laser-irradiated versus control groups. Two-way analysis of variance was used to compare the main effects of laser exposure time and LPS concentration on cytokine/chemokine concentrations and evaluate the potential interaction between these factors. Four pro-inflammatory cytokines – tumor necrosis factor-α, macrophage inflammatory protein (MIP)-1α, MIP-2, and interferon gamma-induced protein-10 – exhibited a trend of reduced secretion in laser-irradiated cultures. The effect appeared more pronounced at longer exposure times (45 and 60 s). However, none of the 27 inflammatory mediators exhibited statistically significant reductions in concentrations in laser-irradiated cultures versus control cultures. These observations do not support a robust anti-inflammatory effect of Nd:YAG laser irradiation. Further studies should explore the potential impact of Nd:YAG laser irradiation on cytotoxicity and cellular growth kinetics and extend across a range of irradiation parameters and cell types.

Prevention and Treatment of Alzheimer's Disease Via the Regulation of the Gut Microbiota With Traditional Chinese Medicine.

Alzheimer's disease (AD) is caused by a variety of factors, and one of the most important factors is gut microbiota dysbiosis. An imbalance in the gut mincrobiota have been shown to change the concentrations of lipopolysaccharide and short-chain fatty acids. These microorganisms synthesize substances that can influence the levels of a variety of metabolites and cause multiple diseases through the immune response, fatty acid metabolism, and amino acid metabolism pathways. Furthermore, these metabolic changes promote the formation of β-amyloid plaques and neurofibrillary tangles. Thus, the microbiota-gut-brain axis plays an important role in AD development. In addition to traditional therapeutic drugs such as donepezil and memantine, traditional Chinese medicines (TCMs) have also showed to significantly decrease the severity of AD symptoms and suppress the underlying related mechanisms. We searched for studies on the effects of different herbal monomers, single herbs, and polyherbal formulas on the gut microbiota of AD patients and identified the relevant pathways through which the gut microbiota affected AD. We conclude that improvements in the gut microbiota not only decrease the occurrence of inflammatory reactions but also reduce the deposition of central pathological products. Herbal monomers have a stronger effect on improving of central pathology. Polyherbal formulas have the most extensive effect on the gut microbiota in patients with AD. Among the effects of formulas, the anti-inflammatory effect is the most essential and is also the main concern regarding the use of TCMs in treating AD from the viewpoint of the gut microbiota. We hope that this review will be helpful for providing new ideas for the clinical application of TCMs in the treatment of AD.

The Novel Lipid Emulsion Vegaven Is Well Tolerated and Elicits Distinct Biological Actions Compared With a Mixed-Oil Lipid Emulsion Containing Fish Oil: A Parenteral Nutrition Trial in Piglets

BackgroundVegaven is a novel lipid emulsion for parenteral nutrition (PN) based on 18-carbon n–3 (ω-3) fatty acids, which elicits liver protection via interleukin (IL) 10 in the murine model of PN. ObjectivesIn a preclinical model of PN in neonatal piglets, Vegaven was tested for efficacy and safety and compared with a mixed-oil lipid emulsion containing fish oil (SMOFlipid). MethodsMale piglets 4–5 d old were randomly allocated to isocaloric isonitrogenous PN for 14 d, which varied only by the type of lipid emulsion (Vegaven, n = 8; SMOFlipid, n = 8). Hepatic IL-10 tissue concentration served as primary outcome. Secondary outcomes were organ weights, bile flow, blood analyses, plasma insulin and glucagon concentrations, insulin signaling, proinflammatory cytokines, tissue lipopolysaccharide concentrations, and fatty acid composition of phospholipid fractions in plasma, liver, and brain. ResultsTotal weight gain on trial, organ weights, and bile flow were similar between the Vegaven and the SMOFlipid group. Vegaven elicited higher hepatic IL10 (Δ = 148 pg/mg protein; P < 0.001) and insulin receptor substrate-2 amounts (Δ = 0.08 OD; P = 0.012). Plasma insulin concentrations (Δ = 1.46 mU/L; P = 0.003) and fructosamine (glycated albumin, Δ = 12.4 μmol/g protein; P = 0.003) were increased in SMOFlipid as compared with those of Vegaven group, indicating insulin resistance. Higher hepatic injury markers were observed more frequently in the SMOFlipid group than those in the Vegaven group. Lipopolysaccharide, tumor necrosis factor-α, and IL-6 concentrations increased in pancreatic and brain tissues of SMOFlipid-treated compared with those in the Vegaven-treated piglets. Insulin signaling reduced in the brains of SMOFlipid-treated piglets. Vegaven and SMOFlipid elicited distinct fatty acid profiles in the phospholipid fractions of the rapidly growing brains but showed similar accretion of docosahexaenoic acid and arachidonic acid after 2 wk of PN. ConclusionsVegaven is well tolerated in this piglet model of PN, demonstrating distinct biological actions compared with SMOFlipid, namely lower liver, pancreas, and brain inflammation, enhanced insulin signaling, and improved whole body glucose control.

Dietary ω-3 Fatty Acids Mitigate Intestinal Barrier Integrity Alterations in Mice Fed a High-Fat Diet: Implications for Pancreatic Carcinogenesis

BackgroundAlthough body fatness is a recognized risk factor for pancreatic ductal adenocarcinoma (PDAC), the underlying mechanisms of how fat composition affects pancreatic carcinogenesis are poorly understood. High-fat diets (HFDs) can disrupt intestinal barrier function, potentially accelerating carcinogenesis. Omega-3 (ω-3) polyunsaturated fatty acids (FAs) have anti-inflammatory properties and help preserve intestinal integrity. ObjectiveThe objective of this study was to evaluate how ω-3 FAs affect the colonic barrier in the context of HFD-induced changes, in a mouse model of PDAC [p48-Cre; LSL-KrasG12D (KC)]. MethodsMale and female KC mice were randomly assigned into 1 of the following 4 groups: 1) a control diet containing ∼11% total calories from fat with an ω-6:ω-3 FA ratio of 10:1 (C), 2) the control diet with high concentrations of ω-3 FA with an ω-6:ω-3 FA ratio of 1:1 (Cω3), 3) an HFD containing 60% total calories from fat with an ω-6:ω-3 FA ratio of approximately 10:1 (HF), and 4) an HFD with high concentrations of ω-3 FA with an ω-6:ω-3 FA ratio of 1:1 (HFω3). ResultsConsumption of an HFD for 8 wk caused: 1) disruption of tight junction structure and function; 2) decreased goblet cell number; 3) higher colonic Toll-like receptor 4 (TLR4) and NADPH oxidase 1 expression; 4) activation of TLR4-triggered pathways, that is, NF-κB, c-Jun N-terminal kinase; 5) elevated plasma lipopolysaccharide concentrations; and 6) higher pancreatic TLR4 expression, and 7) accelerated acinar-to-ductal metaplasia. All of these events were mitigated in mice fed the HFω3. ConclusionsOur findings support the concept that, in the context of obesity, ω-3 FAs have protective effects during early-stage pancreatic carcinogenesis through the regulation of intestinal permeability and endotoxemia.

Short-chain fatty acids enhance muscle mass and function through the activation of mTOR signalling pathways in sarcopenic mice.

Sarcopenia is a prevalent muscle disorder in old people leading to higher fracture rate, mortality, and other adverse clinical outcomes. Evidence indicates that short-chain fatty acids (SCFAs), which are beneficial gut microbial metabolites, were reduced in old people with sarcopenia. This study aimed to determine whether the use of SCFAs as a supplement can be a therapeutic strategy of sarcopenia in a pre-clinical model. Seven-month-old pre-sarcopenic senescent accelerated mouse prone 8 (SAMP8) mice received daily SCFAs cocktail (acetate, butyrate, and propionate) for 3months. Age-matched senescence accelerated mouse resistant 1 (SAMR1) and SAMP8 mice receiving sodium-matched drinking water were control groups. The gut microbiota composition analysis of aged mice with or without sarcopenia was conducted by 16S rDNA sequencing. Gut barrier-related proteins and lipopolysaccharide (LPS) concentration were biomarkers of gut permeability. Colon inflammation levels, circulatory SCFAs concentration, muscle quality, function, and underlying pathways were detected by cell number counting, RT-qPCR, gas chromatography-mass spectrometry, measurements of muscle wet weight and grip strength, ex vivo functional test, treadmill endurance test, transcriptomic sequencing, morphological and immunofluorescent staining, as well as western blot. To investigate the role of mTOR signalling pathways in SCFAs treatment, C2C12 myotubes were treated with rapamycin. Aged SAMP8 mice had different microbiota composition, and lower serum butyric acid compared with SAMR1 mice (P<0.05). SCFAs treatment reversed the increment of colon inflammation (2.8-fold lower of il-1β) and gut barrier permeability (1.7-fold lower of LPS) in SAMP8 mice. Increased muscle mass, myofibre cross-sectional area, grip strength, twitch and tetanic force were found in SCFAs-treated mice compared with control SAMP8 mice (P<0.05). Anti-fatigue capacity (1.6-fold) and muscle glycogen (2-fold) also improved after SCFAs treatment (P<0.05). Transcriptomic analysis showed that AMPK, insulin, and mTOR pathways were involved in SCFAs treatment (P<0.05). Regulation of AKT/mTOR/S6K1 and AMPK/PGC1α pathways were found. SCFAs attenuated fat infiltration and improved mitochondria biogenesis of atrophic muscle. In vitro studies indicated that SCFAs inhibited FoxO3a/Atrogin1 and activated mTOR pathways to improve myotube growth (P<0.05), and rapamycin attenuated the effect of SCFAs through the inhibition of mTOR pathways. This study demonstrated that bacterial metabolites SCFAs could attenuate age-related muscle loss and dysfunction, and protein synthesis-related mTOR signalling pathways were involved both in vivo and in vitro.

Hydrogen alleviates non-alcoholic fatty liver disease in mice by regulating intestinal flora

Despite being the most common form of chronic liver disease, there are still no approved drugs for thetreatment of non-alcoholic fatty liver disease (NAFLD). The aim of this study was to elucidate the therapeutic effects and possible mechanisms of hydrogen (H2) inhalation in mice with NAFLD. Male C57BL/6 mice (6 weeks old) were fed either a 60% fat diet (high-fat diet [HFD]) or a 10% fat diet (normal diet) for 11 weeks. Then, H2 was administered to random HFD-fed mice for another 11 weeks before they were euthanized. Biochemical analysis of serum samples, histological analysis of liver and ileum samples, 16S rRNA sequencing analysis of stool samples, and analysis of the expression levels of related factors by enzyme-linked immunosorbent assay were conducted to determine the effect of H2 intervention on NAFLD. H2 inhalation alleviated hyperglycemia and impaired glucose tolerance; decreased the serum concentrations of triglycerides, cholesterol, alanine aminotransferase, aspartate aminotransferase, lipopolysaccharide, and tumor necrosis factor-alpha; and ameliorated liver injury by a HFD, although no weight loss was observed. Interestingly, H2 inhalation increased the relative abundance of Akkermansia muciniphila and decreased the Firmicutes-to-Bacteroidia ratio in the intestinal tract of NAFLD mice. These data indicate that H2 alleviated the symptoms of NAFLD by increasing the abundance of A. muciniphila in the intestine. Thus, H2 may be a new potential treatment strategy for patients with NAFLD.

Lipopolysaccharide from Proteus mirabilis Slows Platelet Plug Formation in Human Whole Blood

Platelets are well known for their role in hemostasis. Additionally, platelets play a crucial role in immune and inflammatory responses. Toll-like receptors (TLRs) can mediate bacterial interactions during infection, triggering platelets to initiate an inflammatory response. TLR-4 receptors enable direct interactions between platelets and the bacterial lipopolysaccharide (LPS) endotoxin. The aim of this study was to assess platelet plug formation in response to LPS from Proteus mirabilis. Human whole blood was treated with varying concentrations of LPS over a range of incubation times. Then, platelet plug formation time was measured, under high shear conditions using the platelet function analyzer PFA-100, as aperture closure time (CT). The addition of either 2 or 10 µg/mL of LPS to 80% whole blood significantly prolonged the CTs even in the absence of preincubation (p = 0.028 or p = 0.049, respectively). With added preincubation of LPS with whole blood, the measured CTs were further prolonged. If the preincubation time was set to 35 min, then even the addition of 0.2 µg/mL of LPS resulted in significant CT prolongation (p &lt; 0.001). Taken together, the platelet plug formation in the presence of collagen/ADP is significantly prolonged by the presence of LPS in a concentration and preincubation time-dependent manner. Exposure to P. mirabilis LPS reduces the platelet aggregation response in human whole blood.

Parameters Optimization for Improving Bioluminescence Inhibition Assay Using Vibrio fischeri Bacteria to Detect Lipopolysaccharide Toxicity in Aquatic Environments.

Bioluminescence inhibition of Vibrio fischeri is a widely used method for toxicity testing in aquatic environments. Certain complex biological contaminants, such as lipopolysaccharide (LPS), can interfere with metabolic pathways during toxicity assays. The standard 15-minute Vibrio fischeri bioluminescence assay has limitations when evaluating and screening water toxicity against complex and emerging chemicals like LPS. To accurately determine the effects of such substances, it is crucial to use a bioassay that encompasses a sufficient cell cycle period. This study tested LPS at varying incubation times (ranging from 60s to 60min) and concentrations (1-1*10- 12 mg/ml) to identify the appropriate incubation time for bioluminescence inhibition and toxicity testing. The results indicated that bioluminescence inhibition begins within 60s and reaches maximum inhibition at 60min. However, at 30 and 45min, the bacterial response to different concentrations of LPS varied, with some concentrations causing increased bioluminescence. The EC50 values at different times (60s, 15, 30, 45, and 60min) were found to be 0.0012, 0.0063, 4.07e + 54, 3.85e-8, and 3.34e-9mg/ml respectively. This study highlights the importance of considering incubation time when using bioluminescence inhibition to detect acute toxicity in aquatic ecosystems. A longer incubation time may enhance the method's sensitivity and improve its ability to detect low levels of toxins, such as LPS, in water resources.

High-concentrate diet supplemented with hydrolysable tannin improves the slaughter performance, intestinal antioxidant ability and barrier function of fattening lambs.

The objective of current experiment was to study the potential influence of hydrolysable tannin supplementation on slaughter performance, meat quality, intestinal digestive enzyme activity, antioxidant ability and barrier function in fattening lambs. In total, 36 male Hu sheep lambs with similar body weight (15.83 ± 0.48 kg) and days in age (55 ± 2 d) were randomly assigned to one of three groups of 12 animals each: control without tannin (CON) and tannin supplementation groups (TA1, 3 g/d per lamb; TA2, 6 g/d per lamb). All the lambs were reared in individual hutches, and the experiment lasted for 60 d. On d 61, 8 lambs from each group were randomly selected to slaughter. Results showed that the serum diamine oxidase and lipopolysaccharide contents of TA2 group were higher (p < 0.05) than those of CON group. Compared with CON group, the carcass weight and intramuscular fat content of lambs in TA1 group were increased (p < 0.05) and the meat shear force was decreased (p < 0.05). The trypsin activity in the jejunum and ileum of TA1 group was higher (p < 0.05) than that of CON and TA2 groups. Also, tannin supplementation significantly increased (p < 0.05) the level of jejunal and ileal total antioxidant capacity and reduced (p < 0.05) the jejunal malondialdehyde concentration in lambs. The jejunum and ileum of TA1 lambs showed reduced (p < 0.05) tumor necrosis factor-alpha and increased (p < 0.05) interleukin-10 mRNA levels compared with CON lambs. In the jejunum, the secretory immunoglobulin A content of TA1 group was higher (p < 0.05) than that of CON and TA2 groups. Lambs supplemented with tannin at the level of 3 g/d increased (p < 0.05) the gene expressions of claudin-1, claudin-4 and zonula occludens-1 in the jejunum when compared to those of CON and TA2 groups. In summary, tannin supplementation at the level of 3 g/d per animal can improve the production performance and intestinal function of fattening lambs fed a high-concentrate diet.

Pyometra alters uterine aquaporins related with lipopolysaccharide concentrations and antioxidant enzyme activities in bitches

Pyometra is a common life-threatening inflammatory disease with a complex etiopathogenesis that develops during the diestrus stage and can be observed in elderly intact bitches. The present study evaluated five aquaporin (AQP1, AQP2, AQP3, AQP5, and AQP9) transcript abundances and immunolocalization in the uterine tissue, and investigated their relationship with uterine tissue and blood lipopolysaccharide (LPS) concentration, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activity, and nitric oxide (NO) production in dogs suffering from pyometra. The study sampled 36 client-owned intact bitches from different breeds, of which 24 cases were diagnosed with pyometra. Twelve of these bitches in the diestrus stage that presented for elective ovariohysterectomy were used as the control group. Blood samples were collected into tubes without anticoagulant for serum progesterone, LPS concentration, and antioxidant activities at the time of diagnosis. Bacteriological and tissue samples from the uteri were collected after the ovariohysterectomy. The tissue samples were used to determine antioxidant activity, and hormone and toxin concentrations. Transcript abundance of uterine AQPs were determined by qPCR, and their presence and localization were determined by by immunohistochemistry. For all pyometra samples, the bacteria isolated from the uterine swabs were Escherichia coli. Compared to the control group, AQP1, AQP2, and AQP5 were downregulated more than 2-fold, whereas AQP9 was upregulated nearly 3-fold and AQP3 was upregulated more than 4-fold in the pyometra affected uteri (P<0.05). Uterine AQP1 was moderately negatively correlated with serum LPS concentration (r=-0.568, P<0.01) and tissue NO production (r=-0.407, P<0.05). AQP5 was positively correlated with serum SOD activity (r=0.485, P<0.05) and negatively correlated with serum LPS concentration (r=-0.512, P<0.05). AQP9 was negatively correlated with tissue SOD and serum GPx activity. This is the first study to identify AQP9 transcript abundance and immunolocalization in canine uterine tissue. Uterine AQP1, AQP2, AQP3, AQP5, and AQP9 transcript abundances were altered in spontaneously developed canine pyometra while AQP transcript abundance was negatively related to serum toxin concentration, NO production, and antioxidant enzyme activity. Further studies should be conducted to determine the role of altered abundances of AQPs transcripts in pyometra pathogenesis.