Hemorrhagic transformation in patients with large-artery atherosclerotic stroke is associated with the gut microbiota and lipopolysaccharide

Hemorrhagic transformation is a major complication of large-artery atheroscle rotic stroke(a major ischemic stro ke subtype)that wo rsens outcomes and increases mortality.Disruption of the gut microbiota is an important feature of stroke,and some specific bacteria and bacterial metabolites may contribute to hemorrhagic transformation pathogenesis.We aimed to investigate the relationship between the gut microbiota and hemorrhagic transformation in largearte ry atheroscle rotic stro ke.An observational retrospective study was conducted.From May 2020 to September 2021,blood and fecal samples were obtained upon admission from 32 patients with first-ever acute ischemic stroke and not undergoing intravenous thrombolysis or endovascular thrombectomy,as well as 16 healthy controls.Patients with stro ke who developed hemorrhagic transfo rmation(n=15)were compared to those who did not develop hemorrhagic transformation(n=17)and with healthy controls.The gut microbiota was assessed through 16S ribosomal ribonucleic acid sequencing.We also examined key components of the lipopolysaccharide pathway:lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14.We observed that bacterial diversity was decreased in both the hemorrhagic transformation and non-hemorrhagic transfo rmation group compared with the healthy controls.The patients with ischemic stro ke who developed hemorrhagic transfo rmation exhibited altered gut micro biota composition,in particular an increase in the relative abundance and dive rsity of members belonging to the Enterobacteriaceae family.Plasma lipopolysaccharide and lipopolysaccharide-binding protein levels were higher in the hemorrhagic transformation group compared with the non-hemorrhagic transfo rmation group.lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14 concentrations were associated with increased abundance of Enterobacte riaceae.Next,the role of the gut microbiota in hemorrhagic transformation was evaluated using an experimental stroke rat model.In this model,transplantation of the gut microbiota from hemorrhagic transformation rats into the recipient rats triggered higher plasma levels of lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14.Ta ken togethe r,our findings demonstrate a noticeable change in the gut microbiota and lipopolysaccharide-related inflammatory response in stroke patients with hemorrhagic transformation.This suggests that maintaining a balanced gut microbiota may be an important factor in preventing hemorrhagic transfo rmation after stro ke.

Quercetin Alleviates Lipopolysaccharide-Induced Cardiac Inflammation via Inhibiting Autophagy and Programmed Cell Death

Objective The aim of this study is to explore the potential modulatory role of quercetin against Endotoxin or lipopolysaccharide(LPS)induced septic cardiac dysfunction.Methods Specific pathogen-free chicken embryos(n=120)were allocated untreated control,phosphate buffer solution(PBS)vehicle,PBS with ethanol vehicle,LPS(500 ng/egg),LPS with quercetin treatment(10,20,or 40 nmol/egg,respectively),Quercetin groups(10,20,or 40 nmol/egg).Fifteenday-old embryonated eggs were inoculated with abovementioned solutions via the allantoic cavity.At embryonic day 19,the hearts of the embryos were collected for histopathological examination,RNA extraction,real-time polymerase chain reaction,immunohistochemical investigations,and Western blotting.Results They demonstrated that the heart presented inflammatory responses after LPS induction.The LPS-induced higher mRNA expressions of inflammation-related factors(TLR4,TNFα,MYD88,NF-κB1,IFNγ,IL-1β,IL-8,IL-6,IL-10,p38,MMP3,and MMP9)were blocked by quercetin with three dosages.Quercetin significantly decreased immunopositivity to TLR4 and MMP9 in the treatment group when compared with the LPS group.Quercetin significantly decreased protein expressions of TLR4,IFNγ,MMP3,and MMP9 when compared with the LPS group.Quercetin treatment prevented LPS-induced increase in the mRNA expression of Claudin 1 and ZO-1,and significantly decreased protein expression of claudin 1 when compared with the LPS group.Quercetin significantly downregulated autophagyrelated gene expressions(PPARα,SGLT1,APOA4,AMPKα1,AMPKα2,ATG5,ATG7,Beclin-1,and LC3B)and programmed cell death(Fas,Bcl-2,CASP1,CASP12,CASP3,and RIPK1)after LPS induction.Quercetin significantly decreased immunopositivity to APOA4,AMPKα2,and LC3-II/LC3-I in the treatment group when compared with the LPS group.Quercetin significantly decreased protein expressions of AMPKα1,LC3-I,and LC3-II.Quercetin significantly decreased the protein expression to CASP1 and CASP3 by immunohistochemical investigation or Western blotting in treatment group when compared with LPS group.Conclusion Quercetin alleviates cardiac inflammation induced by LPS through modulating autophagy,programmed cell death,and myocardiocytes permeability.

Foeniculum vulgare Mill.inhibits lipopolysaccharide-induced microglia activation and ameliorates neuroinflammation-mediated behavioral deficits in mice

Objective:To investigate the effect of Foeniculum vulgare extract against lipopolysaccharide(LPS)-induced microglial activation in vitro as well as cognitive behavioral deficits in mice.Methods:LPS-activated BV-2 cell viability was measured using MTT assay and reactive oxygen species(ROS)was studied using DCF-DA assay.The antioxidative enzymes and pro-inflammatory mediators were analyzed using respective ELISA kits and Western blotting.For in vivo testing,LPS(1 mg/kg,i.p.)was given daily for five days in male Swiss albino mice to produce chronic neuroinflammation.Cognitive and behavioral tests were performed using open-field,passive avoidance,and rotarod experiments in LPS-induced mice.Results:Foeniculum vulgare extract(25,50 and 100μg/mL)significantly attenuated the LPS-activated increase in nitric oxide(NO),ROS,cyclooxygenase-2,inducible NO synthase,IL-6,and TNF-alpha(P<0.05).Moreover,LPS-induced oxidative stress and reduced antioxidative enzyme levels were significantly improved by Foeniculum vulgare extract(P<0.05).The extract also regulated the NF-κB/MAPK signaling in BV-2 cells.In an in vivo study,Foeniculum vulgare extract(50,100,and 200 mg/kg)markedly mitigated the LPS-induced cognitive and locomotor impairments in mice.The fingerprinting analysis showed distinctive peaks with rutin,kaempferol-3-O-glucoside,and anethole as identifiable compounds.Conclusions:Foeniculum vulgare extract can ameliorate LPS-stimulated neuroinflammatory responses in BV-2 microglial cells and improve cognitive and locomotor performance in LPS-administered mice.

Natural Products Improve Organ Microcirculation Dysfunction Following Ischemia/Reperfusion-and Lipopolysaccharide-Induced Disturbances:Mechanistic and Therapeutic Views

Microcirculatory disturbances are complex processes caused by many factors,including abnormal vasomotor responses,decreased blood flow velocity,vascular endothelial cell injury,altered leukocyte and endothelial cell interactions,plasma albumin leakage,microvascular hemorrhage,and thrombosis.These disturbances involve multiple mechanisms and interactions among mechanisms that can include energy metabolism,the mitochondrial respiratory chain,oxidative stress,inflammatory factors,adhesion molecules,the cytoskeleton,vascular endothelial cells,caveolae,cell junctions,the vascular basement membrane,neutrophils,monocytes,and platelets.In clinical practice,aside from drugs that target abnormal vasomotor responses and platelet adhesion,there continues to be a lack of multi-target drugs that can regulate the complex mechanistic links and interactions underlying microcirculatory disturbances.Natural products have demonstrated obvious positive therapeutic effects in treating ischemia/reperfusion(I/R)-and lipopolysaccharide(LPS)-induced microcirculatory disturbances.In recent years,numerous research papers on the improvement of microcirculatory function by natural products have been published in international journals.In 2008 and 2017,the first listed author of this review was invited to publish reviews in the journal of Pharmacology&Therapeutics on the improvement of microcirculatory disturbances and organ injury induced by I/R using Salvia miltiorrhiza ingredients and other natural components of compounded Chinese medicine,respectively.This review systematically summarizes the effects,targets of action,and mechanisms of natural products regarding improving I/R-and LPSinduced microcirculatory disturbances and tissue injury.Based on this summary,scientific proposals are suggested for the discovery of new drugs to improve microcirculatory disturbances in disease.

Antidepressant effects of Peiyuan Jieyu formula in a mouse model of chronic stress in conjunction with lipopolysaccharide-induced depression

Objective:To explore the mechanism of the Peiyuan Jieyu formula in treating depression by assessing its impact on a lipopolysaccharide-induced(LPS-induced)depression mouse model.Methods:We created a mouse model of depression by exposing mice that had previously received chronic stress to intraperitoneal LPS injections.The mice were divided into the following groups:control,model,fluoxetine,Tiansi Yin,Sini powder,and low-,medium-,and high-dose Peiyuan Jieyu formula groups.Forced swim and tail suspension tests were used to assess the efficacy of the depression(despair)model,and weight gain rates were also measured.Furthermore,serum levels of various depression and inflammation-associated molecules,including tumor necrosis factor-a(TNF-a),interferon-γ(IFN-γ),tryptophan,5-hydroxytryptamine,kynurenine(KYN),and kynurenic acid(KA)were assessed.Furthermore,the expression levels of ionic calcium-binding adaptor molecule-1(IBA-1)and indoleamine 2,3-dioxygenase(IDO)mRNA in hippocampal microglia were measured.Results:The model group displayed greater despair-associated immobility,which was shortened in response to various doses of Peiyuan Jieyu formula.Furthermore,formula administration significantly reduced serum TNF-a levels and hippocampal IDO mRNA expression.The high formula dose also reduced IFN-γand IBA-1 levels,the latter was also decreased in response to the medium formula dose.However,the low formula dose reduced serum KYN level and KYN/tryptophan(TRP)and KYN/KA ratios.Conclusion:The Peiyuan Jieyu formula holds immense potential in treating depression in a mouse model,potentially inhibiting inflammation and improving TRP-KYN metabolic disorders.

Predictive effect of lipopolysaccharide-stimulated inflammatory cytokines on symptoms of generalized anxiety disorder

BACKGROUND Generalized anxiety disorder(GAD)is a relatively common mental disorder.Recently,inflammation,an important factor for the development of depression,has attracted increasing attention.Several studies have shown that inflammatory cytokines can affect the pathophysiological processes of several nervous system diseases.We hypothesized that there is a correlation between the levels of lipopolysaccharide(LPS)-stimulated inflammatory cytokines and the clinical symptoms of GAD.AIM To investigate the predictive effect of LPS-stimulated inflammatory cytokines on symptoms of GAD.METHODS This was a cross-sectional study in which 89 patients with GAD diagnosed at The First Hospital of Hebei Medical University from January 2022 to December 2022 and 70 individuals without anxiety and depression(controls)during the same period were included.Fasting venous blood was collected from all the subjects in heparin tubes,and another 3 ml of blood was supplemented with LPS(10 ng/ml).The plasma levels of 12 cytokines[Interleukin(IL)-1β,IL-2,IL-4,IL-5,IL-6,IL-8,IL-10,tumor necrosis factor(TNF)-α,interferon(IFN)-γ,IL-17A,IL-12p70,and IFN-α]were detected.RESULTS Post-LPS stimulation,the levels of IL-1β,IL-6,IL-8,IL-10,and TNF-αin both the control and GAD groups were significantly elevated above those in the nonstimulated groups,with IL-6 and IL-8 showing marked increases.Increases in IL-8 and TNF-αwere statistically significant in the GAD group(P<0.05).IL-1β,IL-6,IL-8,IL-10,and TNF-αwere found to be significantly correlated with Hamilton Anxiety Rating Scale(HAMA)scores(P<0.05).A negative correlation was observed between IL-10 levels and HAMA scores.Further analysis revealed that TNF-αwas associated with mental anxiety,whereas IL-1β,IL-8,and IL-10 were associated with physical anxiety symptoms,with IL-10 showing a negative correlation with physical anxiety.IL-6 was associated with both mental and physical aspects of anxiety.CONCLUSION The physical symptoms of GAD are related to inflammatory factors.IL-1β,IL-8,IL-10,and TNF-a can be used as predictors of physical or mental anxiety in patients with GAD.

Yeast hydrolysate attenuates lipopolysaccharide-induced inflammatory responses and intestinal barrier damage in weaned piglets

Background Intestinal inflammation is the main risk factor causing intestinal barrier dysfunction and lipopolysaccharide(LPS)can trigger inflammatory responses in various eukaryotic species.Yeast hydrolysate(YH)possesses multibiological effects and is received remarkable attention as a functional ingredient for improving growth performance and promoting health in animals.However,there is still inconclusive on the protective effects of dietary YH supplementation on intestinal barrier of piglets.This study was conducted to investigate the attenuate effects of YH supplementation on inflammatory responses and intestinal barrier injury in piglets challenged with LPS.Methods Twenty-four piglets(with an average body weight of 7.42±0.34 kg)weaned at 21 days of age were randomly assigned to one of two dietary treatments(12 replications with one pig per pen):a basal diet or a basal diet containing YH(5 g/kg).On the 22nd d,6 piglets in each treatment were intraperitoneally injected with LPS at 150μg/kg BW,and the others were injected with the same amount of sterile normal saline.Four hours later,blood samples of each piglet were collected and then piglets were euthanized.Results Dietary YH supplementation increased average daily feed intake and average daily gain(P<0.01),decreased the ratio of feed intake to gain of piglets(P sponse,evidenced by the increase o=0.048).Lipopolysaccharide(LPS)injection induced systemic inflammatory ref serum concentrations of haptoglobin(HP),adrenocorticotropic hormone(ACTH),cortisol,and interleukin-1β(IL-1β).Furthermore,LPS challenge resulted in inflammatory intestinal damage,by up-regulation of the protein or mRNA abundances of tumor necrosis factor-α(TNF-α),IL-1β,toll-like receptors 4(TLR4)and phosphor-nuclear factor-κB-p65(p-NFκB-p65)(P<0.01),and down-regulation of the jejunal villus height,the protein and mRNA abundances of zonula occludens-1(ZO-1)and occludin(OCC;P<0.05)in jejunal mucosa.Dietary YH supplementation decreased the impaired effects of ACTH,cortisol,HP,IL-1βand diamine oxidase in serum(P<0.05).Moreover,YH supplementation also up-regulated the jejunal villus height,protein and mRNA abundances of ZO-1 and OCC(P<0.05),down-regulated the mRNA expressions of TNF-αand IL-1βand the protein abundances of TNF-α,IL-1β,TLR4 and p-NFκB-p65 in jejunal mucosa in LPS-challenged pigs(P<0.01).Conclusion Yeast hydrolysate could attenuate inflammatory response and intestinal barrier injury in weaned piglets challenged with LPS,which was associated with the inhibition of TLR4/NF-κB signaling pathway activation.

Effect of dual targeting procyanidins nanoparticles on metabolomics of lipopolysaccharide-stimulated inflammatory macrophages

Inflammation plays an important role in the occurrence and development of many inflammatory diseases.The purpose of this study was to evaluate the anti-inflammatory effect and metabolic behavior of the dual targeting procyanidins(PC)nanoparticles on lipopolysaccharide(LPS)-stimulated inflammatory macrophages by metabolomics method.The double-targeting PC nanoparticles could specifi cally target both the CD44 receptor and mitochondria,while the single targeting PC-loaded nanoparticles that could target the CD44 receptor on the surface of macrophages.The double-targeting PC nanoparticles had better inhibitory effect than single-targeting PC nanoparticles on the leakage of lactate dehydrogenase and reactive oxygen species overexpression induced by LPS.Amino acid metabolism,energy metabolism and purine metabolism were disordered in LPS-treated group,and metabolic pathway analysis indicated that the double-targeting PC nanoparticles reversed some of LPS impacts.The changes of these potential biomarkers and their corresponding pathways are helpful to further understand the mechanism of PC nanoparticles in alleviating inflammation,and promote their application in nutrition intervention.

Lipopolysaccharide-induced Trigeminal Ganglion Nerve Fiber Damage is Associated with Autophagy Inhibition

Objective This study aimed to determine whether lipopolysaccharide(LPS)induces the loss of corneal nerve fibers in cultured trigeminal ganglion(TG)cells,and the underlying mechanism of LPS-induced TG neurite damage.Methods TG neurons were isolated from C57BL/6 mice,and the cell viability and purity were maintained for up to 7 days.Then,they were treated with LPS(1µg/mL)or the autophagy regulator(autophibib and rapamycin)alone or in combination for 48 h,and the length of neurites in TG cells was examined by the immunofluorescence staining of the neuron-specific proteinβ3-tubulin.Afterwards,the molecular mechanisms by which LPS induces TG neuron damage were explored.Results The immunofluorescence staining revealed that the average length of neurites in TG cells significantly decreased after LPS treatment.Importantly,LPS induced the impairment of autophagic flux in TG cells,which was evidenced by the increase in the accumulation of LC3 and p62 proteins.The pharmacological inhibition of autophagy by autophinib dramatically reduced the length of TG neurites.However,the rapamycin-induced activation of autophagy significantly lessened the effect of LPS on the degeneration of TG neurites.Conclusion LPS-induced autophagy inhibition contributes to the loss of TG neurites.

Uptake of bacterial lipopolysaccharide and expression of tumor necrosis factor α mRNA in isolated rat intrahepatic bile duct epithelial cells *

AIM To study the uptake of bacterial lipopolysaccharides (LPS) and expression of tumor necrosis factor α mRNA (TNF α mRNA) with cultured rat intrahepatic bile duct epithelial cells.

Lipopolysaccharide preconditioning induces protection against lipopolysac-charide -induced neurotoxicity in organotypic midbrain slice culture

Objective To identify the protective effect of lipopolysaccharide （LPS） preconditioning against LPS-induced inflammatory damage in dopaminergic neurons of midbrain slice culture and the possible mechanisms. Methods After cultured in vitro for 14 d, the rat organotypic midbrain slices were pretreated with different concentrations （0, 1, 3, 6 or 10 ng/mL） of LPS for 24 h followed by treatment with 100 ng/mL LPS for 72 h. The whole slice viability was detelmined by measurement of the activity of lactic acid dehydrogenase （LDH）. Tyrosine hydroxylase-immunoreactive （TH-IR） neurons and CD 1 1 b/c equivalent-immunoreactive （OX-42-IR） microglia in the slices were observed by immunohistochemical method, and tumor necrosis factor-α （TNF-α levels in the culture media were detected by enzymelinked immunosorbent assays （ELISA）. Results In the slices treated with 100 ng/mL LPS for 72 h, the number of TH-IR neurons reduced from 191± 12 in the control slices to 46±4, and the LDH activity elevated obviously （P 〈 0.01）, along with remarkably increased number of OX-42-IR cells and production of TNF-α （P 〈 0.01）. Preconditioning with 3 or 6 ng/mL LPS attenuated neuron loss （the number of TH-IR neurons increased to 126± 12 and 180± 13, respectively） and markedly reduced LDH levels （P 〈 0.05）, accompanied by significant decreases of OX-42-IR microglia activation and TNF-α production （P 〈 0.05）. Conclusion Low-dose LPS preconditioning could protect dopaminergic neurons against inflammatory damage in rat midbrain slice culture, and inhibition of microglial activation and reduction of the proinflammatory factor TNF-α production may contribute to this protective effect. Further understanding the underlying mechanism of LPS preconditioning may open a new window for treatment of Parkinson＇s disease.

Ginsenoside Rb1 protects dopaminergic neurons from inflammatory injury induced by intranigral lipopolysaccharide injection

Accumulating studies suggest that neuroinflammation characterized by microglial overactivation plays a pivotal role in the pathogenesis of Parkinson’s disease.As such,inhibition of microglial overactivation might be a promising treatment strategy to delay the onset or slow the progression of Parkinson’s disease.Ginsenoside Rbl,the most active ingredient of ginseng,reportedly exerts neuroprotective effects by suppressing inflammation in vitro.The present study aimed to evaluate the neuroprotective and anti-inflammatory effects of ginsenoside Rbl in a lipopolysaccharide-induced rat Parkinson’s disease model.Rats were divided into four groups.In the control group,sham-operated rats were intraperitoneally administered normal saline for 14 consecutive days.In the ginsenoside Rbl group,ginsenoside Rb1(20 mg/kg)was intraperitoneally injected for 14 consecutive days after sham surgery.In the lipopolysaccharide group,a single dose of lipopolysaccharide was unilaterally microinjected into the rat substantial nigra to establish the Parkinson’s disease model.Lipopolysaccharide-injected rats were treated with normal saline for 14 consecutive days.In the ginsenoside Rbl +lipopolysaccharide group,lipopolysaccharide was unilaterally microinjected into the rat substantial nigra.Subsequently,ginsenoside Rbl was intraperitoneally injected for 14 consecutive days.To investigate the therapeutic effects of ginsenoside Rbl,behavioral tests were performed on day 15 after lipopolysaccharide injection.We found that ginsenoside Rbl treatment remarkably reduced apomorphine-induced rotations in lipopolysaccharide-treated rats compared with the lipopolysaccharide group.To investigate the neurotoxicity of lipopolysaccharide and potential protective effect of ginsenoside Rbl,contents of dopamine and its metabolites in the striatum were measured by high-performance liquid chromatography.Compared with the lipopolysaccharide group,ginsenoside Rbl obviously attenuated the lipopolysaccharide-induced depletion of dopamine and its metabolites in the striatum.To further explore the neuroprotective effect of ginsenoside Rbl against lipopolysaccharide-induced neurotoxicity,immunohistochemistry and western blot assay of tyrosine hydroxylase were performed to evaluate dopaminergic neuron degeneration in the substantial nigra par compacta.The results showed that lipopolysaccharide injection caused a large loss of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra and a significant decrease in overall tyrosine hydroxylase expression.However,ginsenoside Rb1 noticeably reversed these changes.To investigate whether the neuroprotective effect of ginsenoside Rbl was associated with inhibition of lipopolysaccharide-induced microglial activation,we examined expression of the microglia marker Iba-1.Our results confirmed that lipopolysaccharide injection induced a significant increase in Iba-1 expression in the substantia nigra;however,ginsenoside Rbl effectively suppressed lipopolysaccharide-induced microglial overactivation.To elucidate the inhibitory mechanism of ginsenoside Rb1,we examined expression levels of inflammatory mediators(tumor necrosis factor-a,interleukin-1β,inducible nitric oxide synthase,and cyclooxygenase 2)and phosphorylation of nuclear factor kappa B signaling-related proteins(IκB,IKK)in the substantia nigra with enzyme-linked immunosorbent and western blot assays.Our results revealed that compared with the control group,phosphorylation and expression of inflammatory mediators IκB and IKK in the substantia nigra of lipopolysaccharide group rats were significantly increased;whereas,ginsenoside Rbl obviously reduced lipopolysaccharide-induced changes on the lesioned side of the substantial nigra par compacta.These findings confirm that ginsenoside Rbl can inhibit inflammation induced by lipopolysaccharide injection into the substantia nigra and protect dopaminergic neurons,which may be related to its inhibition of the nuclear factor kappa B signaling pathway.This study was approved by the Experimental Animal Ethics Committee of Shandong University of China in April 2016(approval No.KYLL-2016-0148).

Raising on Water Stocking Density Reduces Geese Reproductive Performances via Water Bacteria and Lipopolysaccharide Contaminations in “Geese-Fish” Production System

This study was carried out to unravel the mechanism of reductions in production performances in high stocking density geese flocks during summer months in ＂geese-fish＂ production system. Experiment 1 observed the water bacterial growth, lipopolysaccharde concentrations in water and geese blood, and geese reproductive performances from summer to winter, in two flocks with varying on water stocking densities. Results showed that counts of total bacteria, Escherichia coli and Salmonella in water, as well as water and geese plasma LPS concentrations, exhibited a tendency decreasing from the highest levels in summer, to intermediate levels in autumn, and to the lowest values in winter. Such seasonal decreases in bacteria and LPS concentrations were associated with similar seasonal decreases in embryo mortality during incubation. In addition, embryos dead or showing development retardation by day 25 of incubation contained copious LPS in allantoic fluid, in contrast to the negligible amount in normal developing embryos. Raising on water stocking density elevated bacteria counts, LPS concentrations in water and geese plasma, and decreased egg fertility but increased embryo mortality during incubation. In experiment 2, exogenous LPS treatment to the geese depressed egg laying, reduced egg hatchability, caused sickness behavior in the goslings hatched. In experiment 3, exogenous LPS directly administered to day 8 and 18 embryos during incubation dose dependently increased mortality and decreased hatchability, and caused sickness behavior in the goslings hatched. It is concluded that the raising on water geese stocking density stimulates pathogenic bacteria growth in water, which via LPS contamination impaires embryo development in incubation and therefore reduces geese reproductive performance and gosling quality during the hot summer months.

Structural modifications of Helicobacter pylori lipopolysaccharide:An idea for how to live in peace

In this review, we discuss the findings and concepts underlying the &#x0201c;persistence mechanisms&#x0201d; of Helicobacter pylori (H. pylori), a spiral-shaped, Gram-negative rod bacterium that was discovered as a gastric pathogen by Marshall and Warren in 1984. H. pylori colonizes the gastric mucosa of nearly half of the human population. Infections appear in early childhood and, if not treated, persist for life. The presence or absence of symptoms and their severity depend on multiple bacterial components, host susceptibility and environmental factors, which allow H. pylori to switch between pathogenicity and commensalism. Many studies have shown that H. pylori components may facilitate the colonization process and the immune response of the host during the course of H. pylori infection. These H. pylori-driven interactions might result from positive or negative modulation. Among the negative immunomodulators, a prominent position is occupied by a vacuolating toxin A (VacA) and cytotoxin-associated gene A (CagA) protein. However, in light of the recent studies that are presented in this review, it is necessary to enrich this panel with H. pylori lipopolysaccharide (LPS). Together with CagA and VacA, LPS suppresses the elimination of H. pylori bacteria from the gastric mucosa by interfering with the activity of innate and adaptive immune cells, diminishing the inflammatory response, and affecting the adaptive T lymphocyte response, thus facilitating the development of chronic infections. The complex strategy of H. pylori bacteria for survival in the gastric mucosa of the host involves both structural modifications of LPS lipid A to diminish its endotoxic properties and the expression and variation of Lewis determinants, arranged in O-specific chains of H. pylori LPS. By mimicking host components, this phenomenon leaves these bacteria &#x0201c;invisible&#x0201d; to immune cells. Together, these mechanisms allow H. pylori to survive and live for many years within their hosts.

Sanguinarine Attenuates Lipopolysaccharide-induced Inflammation and Apoptosis by Inhibiting the TLR4/NF-KB Pathway in H9c2 Cardiomyocytes

The inflammatory response is involved in the pathogenesis of the most common types of heart disease. Sanguinarine （SAN） has various pharmacological properties such as anti-inflammatory, antioxidant, antibacterial, antitumor, and immune-enhancing properties. However, few studies have investigated the effects of SAN on lipopolysaceharide （LPS）-induced inflammatory and apoptotic responses in H9c2 cardiomyocytes. Therefore, in this study, H9c2 cells were co-treated with SAN and LPS, and the mRNA levels of pro-inflammation markers and the apoptosis rate were measured to clarify the effect of SAN on cardiac inflammation. The underlying mechanism was further investigated by detecting the activation of Toll-like receptor （TLR）4/nuclear faetor-κB （NF-κB） signaling pathways. As a result, increased mRNA expression of interleukin （IL）-1β, IL-6, and TNFα induced by LPS was attenuated after SAN treatment; LPS-induced apoptosis ofHge2 cardiomyocytes and cleaved-caspase 8, 9, 3 were all significantly reduced by SAN. Further experiments showed that the beneficial effect of SAN on blocking the inflammation and apoptosis of H9c2 cardiomyocytes induced by LPS was associated with suppression of the TLR4/NF-κB signaling pathway. It was suggested that SAN suppressed the LPS-induced inflammation and apoptosis of H9c2 cardiomyocytes, which may be mediated by inhibition of the TLR4/NF-κB signaling pathway. Thus, SAN may be a feasible therapy to treat sepsis patients with cardiac dysfunction.

The anti-inflammatory effects of asiatic acid in lipopolysaccharide-stimulated human corneal epithelial cells

AIM： To investigate the anti-inflammatory effects of asiatic acid（AA） on lipopolysaccharide（LPS）-induced inflammatory response in human corneal epithelial cells（HCECs）.METHODS： Cell viability was measured using a cell counting kit-8（CCK-8） assay.Quantitative real-time polymerase chain reaction（qR T-PCR） was used to determine the mR NA expression of interleukin-8（IL-8）,interleukin-6（IL-6）,interleukin-1β（IL-1β）,tumor necrosis factor-alpha（TNF-α）,and transforming growth factor-β（TGF-β） in HCECs.Intracellular reactive oxygen species（ROS） was measured using the ROS assay kit.Glutathione（GSH） concentration was measured using the total GSH assay kit.Akt1 and Akt phosphorylation（p-Akt1） levels were measured by Western blotting and immunofluorescence.RESULTS： AA induced toxicity at high concentrations and significantly stimulated the proliferation of HCECs at concentrations of 20 μmol/L for 1h.LPS at concentrations of 300 ng/mL for 1h significantly stimulated the mR NA expression of IL-8,IL-6,IL-1β,TNF-α,and TGF-β in HCECs,while the stimulation effects were significantly inhibited by AA（20 μmol/L）.In addition,AA was found to decrease the content of ROS,increase GSH generation,and also inhibit LPS-induced p-Akt in HCECs.CONCLUSION： AA decreases the generation of inflammatory factors IL-8,IL-6,IL-1β,TNF-α,and TGF-β in LPSstimulated HCECs.AA significantly inhibites the intracellular concentrations of ROS and increases GSH generation.AA also inhibites LPS-induced p-Akt in HCECs.These findings reveal that AA has anti-inflammation effects in LPS-stimulated HCECs.

β-arrestin 2 attenuates lipopolysaccharide-induced liver injury via inhibition of TLR4/NF-κB signaling pathwaymediated inflammation in mice

AIM To study the role and the possible mechanism of β-arrestin 2 in lipopolysaccharide(LPS)-induced liver injury in vivo and in vitro.METHODS Male β-arrestin 2^(+/+) and β-arrestin 2^(-/-)C57 BL/6 J mice were used for in vivo experiments, and the mouse macrophage cell line RAW264.7 was used for in vitro experiments. The animal model was established via intraperitoneal injection of LPS or physiological sodium chloride solution. Blood samples and liver tissues were collected to analyze liver injury and levels of pro-inflammatory cytokines. Cultured cell extracts were collected to analyze the production of pro-inflammatory cytokines and expression of key molecules involved in the TLR4/NF-κB signaling pathway.RESULTS Compared with wild-type mice, the β-arrestin 2 knockout mice displayed more severe LPS-induced liver injury and significantly higher levels of proinflammatory cytokines, including interleukin(IL)-1β, IL-6, tumor necrosis factor(TNF)-α, and IL-10. Compared with the control group, pro-inflammatory cytokines(including IL-1β, IL-6, TNF-α, and IL-10) produced by RAW264.7 cells in the β-arrestin 2 si RNA group were significantly increased at 6 h after treatment with LPS. Further, key molecules involved in the TLR4/NF-κB signaling pathway, including phosphoIκBα and phosho-p65, were upregulated.CONCLUSION β-arrestin 2 can protect liver tissue from LPS-induced injury via inhibition of TLR4/NF-κB signaling pathwaymediated inflammation.

Effect of Lianshu preparation on lipopolysaccharide-induced diarrhea in rats

AIM： To investigate the effect of Lianshu preparation on lipopolysaccharide （LPS）-induced diarrhea in rats. METHODS： A diarrhea model was established in Sprague Dawley rats via injection of 1 mL of 30 mg/kg LPS. A total of 40 rats were randomly divided into normal group, LPS group, LPS ＋ Lianshu group, LPS ＋ berberine group （n = 10 in each group）. Their intestinal mucosal barrier and frequency of diarrhea were observed. Levels of glucose, serum Na^＋, K^＋, Cl and hematocrit, plasma nitrogen monoxide （NO）, diamine oxidase （DAO）, and D （-）-lactate were measured. The number of IgA＋ plasma cells in small intestine was detected and SIgA levels in the intestinal fluid were measured. The antipyretic activity of Lianshu preparation in rats was evaluated using Brewer＇s yeast-induced pyrexia （10 mL/kg of 20% aqueous suspension）. Acetaminophen （250 mg/kg, intragastric administration, bid） was comparison. Temperature used as a standard drug for was recorded 1 h before and 6 h after Brewer＇s yeast injection. Finally, small intestina transmission in mice treated with Lianshu was detected after intraperitoneal injection of methyl prostigmin （2 mg/kg）. Atropine （10 g/kg） was used as a control. The ink content in intestine was determined and the total length of intestine was measured. RESULTS： The frequency of diarrhea was higher in LPS group than in LPS ＋ Lianshu group and LPS ＋ berberine group （36.70± 5.23 vs 28.50 ±4.06 and 32.70±9.30 respectively, P 〈 0.01）, and lower in LP5 ＋ Lianshu group than in LPS ＋ berberine group （P = 0.03）. The levels of Na＋, glucose, Cl, K^＋ were significantly lower in LPS ＋ Lianshu group than in LPS ＋ berberine group （140.35±3.19 mmol/L vs 131.99±4.86 mmol/L, 8.49 ±1.84 mmol/L vs 6.54±2.30 mmol/L, 106.29± 4.41 mmol/L vs 102.5±1.39 mmol/L, 5.08±0.66 mmol/L vs 4.32 ± 0.62 mmol/L respectively, P 〈 0.05）. The level of hematocrit was lower in LPS ＋ Lianshu group than in LPS ＋ berberine group （0.50% ±0.07% vs 0.59%± 0.10% respectively, P 〈 0.05）. The plasma levels of NO, DAO and D （-）-lactate were higher in LPS group than in normal group （79.74 ± 7.39μmol/L vs 24.94 ± 3.38μmol/L, 2.48 ±0.42μ/mL vs 0.82 ±0.33 p/mL, 5.63± 0.85μg/mL vs 2.01 ±0.32 μg/mL respectively, P 〈 0.01）, and lower in LPS ＋ Lianshu group than in LP5 ＋ berberine group （48.59±4.70μmol/L vs 51.56 ±8.38 μmol/L, 1.43± 0.53μmol/mL vs 1.81 ±0.42 μmol/mL, 4.00± 0.54 μg/mL vs 4.88 ± 0.77 pg/mL respectively, P 〈 0.05）. The morphology of the intestinal mucosa showed destroyed villi in LPS group and atrophied intestinal mucosa in other groups. The pathological intestinal mucosal changes were less in LPS ＋ Lianshu group than in LPS group. The number of IgA＋ plasma cells and amount of SIgA were higher in LPS ＋ Lianshu group than in LPS group （1.16±0.19/μm^2 vs 1.09±0.28/μm^2, P = 0.026; 0.59 ±0.12 mg/L vs 0.15± 0.19 mg/L respectively, P = 0.000）. Lianshu had counteractive effects on yeast-induced pyrexia and enterokinesia in rats. CONCLUSION： Lianshu preparation has therapeutic effects on LPS-induced diarrhea and enterokinesia in rats.

Hyperoside Suppresses Lipopolysaccharide-induced Inflammation and Apoptosis in Human Umbilical Vein Endothelial Cells

Finding the novel drug from the effective components of traditional Chinese herbal medicine is a hotspot of the modem pharmacological research. Hyperoside （HYP） belongs to flavonoid glycosides, and it has various properties, such as anti-inflammation, anti-spasm, anti-diuretic, antitussive, lowering blood pressure, and lowering cholesterol effects as well as protective effects for the cardiac and cerebral blood vessels. The purpose of this study was to investigate the effects of HYP on inflammatory and apoptotic responses in vascular endothelial cells stimulated by lipopolysaccharide （LPS） and further to identify the possible mechanisms underlying these effects. In our study, human umbilical vein endothelial cells （HUVECs） were stimulated with 1 Bg/mL LPS in the presence or absence of HYP （10, 20 and 50 μmol/L）. Our results indicated that HYP alone exerted no cytotoxicity on HUVECs, while it had an upregulatory effect on the viability of HUVECs induced by LPS in a dose-dependent manner; increased mRNA expression of IL-1β, IL-6, TNFα and iNOS induced by LPS was attenuated after treatment with HYP both in a dose- and time-dependent manner; LPS-induced HUVECs apoptosis and cleaved-caspase 8, 9, 3 were all significantly reduced by HYP. Furthermore, the possible pathway involved in apoptosis and inflammation by HYP was detected, and the results showed that when treated with HYP, LPS-induced mitochondrial membrane instability was significantly inhibited through up-regulation of Bcl-2 and down-regulation of Bax. Furthermore, the expression of TLR4 and the phosphorylation of IκBα and p65 in LPS-treated cells were blocked by HYP. Our results suggested that HYP treatment prevented HUVECs from LPS- induced inflammation and apoptosis responses, which might be mediated by inhibiting TLR4/ NFκB pathway.

Ethanol extracts of Scutellaria baicalensis protect against lipopolysaccharide-induced acute liver injury in mice

Objective: To investigated the protective potential of ethanol extracts of Scutellaria baicalensis(S. baicalensis) against lipopolysaccharide(LPS)-induced liver injury. Methods: Dried roots of S. baicalensis were extracted with ethanol and concentrated to yield a dry residue. Mice were administered 200 mg/kg of the ethanol extracts orally once daily for one week. Animals were subsequently administered a single dose of LPS(5 mg/kg of body weight, intraperitoneal injection). Both protein and m RNA levels of cytokines, such as tumor necrosis factor alpha, interleukin-1β, and interleukin-6 in liver tissues were evaluated by ELISA assay and quantitative PCR. C yclooxygenase-2, inducible nitric oxide synthase, and nuclear factor-κB protein levels in liver tissues were analyzed by western blotting. Results: Liver injury induced by LPS signifi cantly increased necrosis factor alpha, interleukin-1β, interleukin-6, cyclooxygenase-2, inducible nitric oxide synthase, and nuclear factor-κB in liver tissues. Treatment with ethanol extracts of S. baicalensis prevented all of these observed changes associated with LPS-induced injury in liver mice.Conclusions: Our study showed that S. baicalensis is potentially protective against LPS-induced liver injury in mice.