LPS-treated Group Research Articles

Acute effects of lipopolysaccharide (LPS) in kidney of rats and preventive role of vitamin E and sodium selenite.

Lipopolysaccharide (LPS) as an endotoxin forms part of the cell wall of gram-negative bacteria and is responsible for initiating an acute inflammation after entering the living tissue. In this study, male rats were divided into eight groups: control group, vitamin E (VE) treatment group (200 mg/kg body weight (b.w.)), sodium selenite (SS) treatment (0.35 mg/kg b.w.) group, VE + SS treatment group (200 + 0.35 mg/kg b.w.), LPS treatment group (10 mg/kg b.w.), LPS + VE (10+200 mg/kg b.w.), LPS + SS treatment (10 + 0.35 mg/kg b.w.), and LPS + SS + VE treatment (10 + 0.35 + 200 mg/kg b.w.) group. Oxidative stress parameters, pathological changes, immunohistochemical analyses, terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end-labeling (TUNEL) assay, and changes in DNA structure with comet assay of the kidney were investigated at the end 6 h comparatively with the control group. When LPS-treated group was compared with the control group, antioxidant enzyme activities were decreased and malondialdehyde (MDA) levels, changes in histological and DNA structure and apoptosis were increased significantly at the end of 6 h. However, when LPS + SS and/or VE-treated group were compared with the LPS-treated group, superoxide dismutase, catalase, glutathione peroxidase, and glutathione- S-transferase activities were increased and MDA levels were decreased significantly at the end of the treatment period. Light investigations figured out pathological changes in kidneys of LPS- and LPS + SS and/or VE-treated groups. There was a decrease in the number of proliferating cell nuclear antigen-positive cells and an increase in the number of TUNEL-positive apoptotic cells in the wall of the distal and proximal tubules. As a result, it was observed that the combined use of antioxidants was more protective than their use alone against LPS.

Effects of lipopolysaccharide administration and maternal deprivation on anxiety and depressive symptoms in male and female Wistar rats: Neurobehavioral and biochemical assessments

IntroductionPreclinical studies of early-life adversity (ELA11Early-life adversity: ELA. Lipopolysaccharide: LPS. Maternal deprivation: MD. Intraperitoneal: IP. Postnatal day: PND. Phosphate buffered saline: PBS. Nitric oxide: NO. Prefrontal cortex: PFC. Hippocampus: HP. Thiobarbituric-acid-reacting substances: TBARS. Superoxide dismutase: SOD. Nitroblue tetrazolium: NBT.) have highlighted the role of postnatal stress in the emergence and persistence of anxiety and depressive disorders. In this study, we compared anxious and depressive behaviors and oxidation levels in male and female Wistar rats subjected to three ELAs (lipopolysaccharide (LPS) induced, maternal deprivation (MD), or combination of the two stressors). MethodsRats were split into four groups: control group which received an intraperitoneal (IP) injection of saline on postnatal day (PND) 1, LPS-treated group which received an IP injection of LPS on PND1, MD group which was exposed to a 24-hour period of isolation on PND9, and LPS-treated/MD group which received an IP injection of LPS on PND1 then was exposed to a 24-hour period of isolation on PND9. Each group consisted of 12 rats and had an equal gender distribution. At three months, rats were subjected to neurobehavioral assessments and biochemical oxidative assays. ResultsCompared to controls, rats in the LPS and MD groups scored significantly higher on anxiety and depression-related measures. Gender differences in response were mainly observed in the MD group. Exposure to the combination of stressors led to a characteristic decrease in anxiety and an increase in depressive measures in both genders. All groups exposed to ELA showed a statistically significant increase in their oxidative stress levels. ConclusionResponse to ELA is gender-dependent and modulated by the nature, type, and number of stressors. Further investigations are critical to understand the mechanisms underlying combination of stressors and gender’s effect.

Evaluation of the effects of Uncaria rhynchophylla alkaloid extract on LPS-induced preeclampsia symptoms and inflammation in a pregnant rat model.

Excessive pro-inflammatory cytokines result in adverse pregnancy outcomes, including preeclampsia-like phenotypes, and fetal growth restriction. Anti-inflammation might be an effective therapy. The aim of this research was to investigate whether Uncaria rhynchophylla alkaloid extract (URE), a highly safe anti-inflammation constituent of the herb, can inhibit inflammation and improve clinical characteristics of preeclampsia in a lipopolysaccharide (LPS)-induced preeclampsia rat model. The rat model was established by daily administration of LPS (1 μg/kg body weight per day) from gestational day (GD) 14 to 19. Different doses of URE (35, 70, and 140 mg/kg body weight per day) were administered from GD 14 to GD 19. The effects of URE on proteinuria, maternal hypertension, pregnancy outcomes, as well as pro-inflammatory cytokines levels in serum and placenta were measured. High-dose URE (HURE) treatment decreased LPS-induced mean 24-h proteinuria and systolic blood pressure, and increased fetal weight, placental weight, and the number of live pups (P<0.05). Moreover, increased serum and placental levels of interleukin (IL)-6, IL-1β, tumor necrosis factor-α, and interferon-γ in the LPS-treated group were obviously inhibited after HURE administration (P<0.01). URE improved preeclampsia symptoms and mitigated inflammatory responses in the LPS-induced preeclampsia rat model, which suggests that the anti-inflammation effect of URE might be an alternative therapy for preeclampsia.

LPS expands MDSCs by inhibiting apoptosis through the regulation of the GATA2/let-7e axis.

Myeloid-derived suppressor cells (MDSCs) represent a group of immature myeloid cells composed of myeloid progenitor cells and immature myeloid cells that can negatively regulate immune responses by inhibiting T-cell function. In mice, MDSCs are broadly defined by the expression of CD11b and Gr1. We and others have shown that injection of a lethal or sublethal dose of lipopolysaccharide (LPS) into mice could result in the expansion of MDSCs in the bone marrow (BM), spleen and blood. Until now, the molecular mechanisms responsible for this expansion are poorly studied; specifically, the roles of the individual microRNAs (miRNAs) which may be involved remain largely unknown. We performed microarray analysis to compare the miRNA expression profiles of CD11b+ Gr1+ cells sorted from the BM of LPS-injected and phosphate-buffered saline-injected mice. We identified let-7e, which was highly upregulated in the LPS-treated group, as a potent regulator of LPS-induced MDSC expansion. Furthermore, let-7e overexpression in BM chimeric mice led to a noticeable increase in the population of CD11b+ Gr1+ cells, which resulted from reduced cellular apoptosis. Further studies showed that let-7e could directly target caspase-3 to inhibit cell apoptosis, and upregulation of let-7e in LPS-stimulated MDSCs could be due to the relieved repression of let-7e transcription exerted by downregulated GATA2. Our findings suggest that LPS expands MDSCs by inhibiting apoptosis through the regulation of the GATA2/let-7e axis.

Systemic Inflammation Impairs Proliferation of Hippocampal Type 2 Intermediate Precursor Cells.

Neurogenesis is a plastic event modulated by external cues. Systemic inflammation decreases neurogenesis in the dentate gyrus (DG) in part through the proliferative restrain of neural precursor cells (NPCs). To evaluate if inflammation affects the cell cycle progression of particular populations of NPCs, we treated young-adult mice with a single i.p. injection of saline or 1mg/kg LPS. After 7days, we analysed proliferation of new BrdU+/DCX+ cells through immunohistochemistry. We extracted the hippocampus and performed a neurosphere assay and a flow cytometric analysis to evaluate proliferation and to identify the phase of the cell cycle in specific populations of DG-derived NPCs. We show that the number of BrdU+/DCX+ cells diminishes in the LPS-treated group and that the number of primary neurospheres derived from LPS-injected animals is significantly reduced compared to the saline-injected group. Flow cytometry revealed that inflammation does not affect the total number of Type 1 BLBP+/TBR2- cells, while the total number of Type 2 intermediate precursor cells (IPCs) (TBR2+) from the LPS-treated group was increased. Cell cycle analysis shows a decrease in the total rate of NPCs in phases S, G2 and M in the LPS-treated group. The percentage of Type 1 BLBP+/TBR2- cells in each cell cycle phase was not different between groups, while there was a fewer number of Type 2 TBR2+ cells in S/G2/M phase. These results show that inflammation alters the appropriate cell cycle progression of Type 2 IPCs, which may contribute to the decrease in the birth rate of DG neurons.

Inhibitory Effect of LPS on the Proliferation of Oligodendrocyte Precursor Cells through the Notch Signaling Pathway in Intrauterine Infection-induced Rats

Periventricular white matter injury (PWMI) is very common in survivors of premature birth, and the final outcomes are a reduction in myelinated neurons leading to white matter hypomyelination. How and (or) why the oligodendrocyte lineage develops abnormally and myelination is reduced is a hot topic in the field. This study focuses on the effect of intrauterine inflammation on the proliferation of oligodendrocyte lineage cells and the underlying mechanisms. Lipopolysaccharide (LPS) (300 μg/kg) was intraperitoneally injected into pregnant Sprague-Dawley rats at embryonic days 19 and 20 to establish a rat model of intrauterine infection-induced white matter injury. Corpus callosum tissues were collected at postnatal day 14 (P14) to quantify the number of oligodendrocytes, the number and proliferation of oligodendrocyte precursor cells (OPCs), and the expression of myelin proteins (MBP and PLP). Furthermore, the expression of Wnt and Notch signaling-related proteins was analyzed. The results showed that the number of oligodendrocytes in the corpus callosum tissues of LPS-treated rats was reduced, and the expression levels of myelinating proteins were down-regulated. Further analysis showed that the Notch signaling pathway was down-regulated in the LPStreated group. These results indicate that intrauterine LPS may inhibit the proliferation of OPCs by down-regulating the Notch rather than the Wnt signaling pathway, leading to hypomyelination of white matter.

Tenacissoside H exerts an anti-inflammatory effect by regulating the nf-κb and p38 pathways in zebrafish

Marsdenia tenacissima exhibits biological activity with heat-clearing and detoxifying properties, relieving coughs and asthma and exerting anticancer and anti-HIV effects. Tenacissioside H (TH) is a Chinese medicine monomer extracted from the dried stem of Marsdenia tenacissima. We investigated the in vivo anti-inflammatory activity of TH using three different zebrafish inflammation models: local inflammation induced by tail cutting, acute inflammation induced by CuSO4, and systemic inflammation induced by lipopolysaccharide (LPS). Real time-polymerase chain reaction (RT-PCR) was used to elucidate the mechanism of TH action against LPS-induced inflammatory responses. Our results showed TH significantly reduced the number of macrophages in the injured zebrafish tail, inhibited CuSO4-induced migration of macrophages toward the neural mound, and decreased the distribution of macrophages in tail fin compared to LPS-treated group. Furthermore, TH inhibits LPS-induced inflammation responses in zebrafish by modulating the nuclear factor κB (nf-κb) and p38 pathways to regulate inflammatory cytokines, such as tumor necrosis factor-α (tnf-α), cyclooxygenase (cox-2), interleukin-1b (il-1b), interleukin-8 (il-8), interleukin-10 (il-10), nitric oxide synthase (nos2b) and prostaglandin E synthase (ptges). In conclusion, TH possesses anti-inflammation activity via the regulation of the nf-κb and p38 pathways. This finding provides a reference for the clinical application of Xiaoaiping (the trade name of Marsdenia tenacissima extract).

Quantitative proteomics using tandem mass tags in relation to the acute phase protein response in chicken challenged with Escherichia coli lipopolysaccharide endotoxin

The inflammatory response in chickens (Gallus Gallus domesticus) is an integral part of the bird's response to infection. Detailing proteomic changes occurring during infection would be beneficial to the poultry industry, offering opportunities for comparative pathophysiological analysis. The objective of this study was to quantify the changes in the plasma proteome in chickens challenged with lipopolysaccharide (LPS), a bacterial endotoxin known to stimulate the host innate immune system. Plasma from chicken (N = 6) challenged with Escherichia coli (LPS) (2 mg/kg body weight) was collected pre (0 h) and at 12, 24, 48, and 72 h post-injection along with plasma from a control group (N = 6) challenged with sterile saline. Samples were analysed by a quantitative Tandem Mass Tags approach using a Q-Exactive-Plus mass-spectrometer. Identification and relative quantification were performed using Proteome Discoverer, and data were analysed using R. Gene Ontology terms were analysed by Cytoscape based on the Gallus gallus database. Finally, 87 significantly regulated proteins were found, including serum-amyloid-A, ovotransferrin and alpha-1-acid-glycoprotein, showing a significant effect of time post-injection in the LPS-treated group. Different pathways related with protein activation cascade and heterotopic cell-cell adhesion were affected by LPS-challenge. LPS-challenged chickens demonstrate significant changes to the plasma proteome with both increases and decreases of individual proteins within 12 h of challenge. SignificanceThe injection of chicken with bacterial lipopolysaccharide followed by sequential plasma and clinical analysis of the bird, is a long established and a widely used model for inflammation and infection studies. This study, utilising and combining proteomic and immunoassay analysis with bioinformatic analysis, revealed that several biological pathways are modulated during this early period of inflammation. In addition, proteins with biomarker potential were identified and successfully validated. This experimental model also demonstrated potential for pathophysiological mechanism investigation and as an inflammatory model for biomedical research. There is, despite plasma being an easily accessible biological matrix which is representative of the health status of the bird, scarce data on the chicken plasma proteome. This research makes a positive contribution to the current field, generating significant data for continuing comparative analysis.

Evaluation of Physiological Functionalities and Anti-inflammatory Activity on in vitro Cultured Adventitious Root of Platycodon grandiflorum

This study was executed to evaluate the phenolic content, DPPH, ABTS radical scavenging rate, nitrite scavenging rate, and anti-inflammatory activity from in vitro cultured adventitious root extract of different Platycodon grandiflorum(PG) variety. Total polyphenol and flavonoid content showed the highest amount in adventitious root extract of tetraploid PG, and followed by green petal, double petal and diploid PG extract. The DPPH radical scavenging activity showed that the increase was proportional to the concentration, especially, the scavenging activity at a concentration of 10 mg mL-1 was higher than 80%. The ABTS radical scavenging activity was not significantly different among the PG varieties at the concentration of 5 mg mL-1 or more, and generally showed high scavenging activity. The nitrite scavenging activity was affected by pH, at pH of 1.2, the scavenging effect of all of the extracts tested observed higher than that of the other two pH ranges. The cytotoxicity of PG extract at various concentrations, the survival rate of RAW 264.7 cell was more than 90% at a concentration of 200 μg mL-1 or less, and it was confirmed that the macrophage cell showed little toxicity. After PG extract pretreatment at 50, 100, and 200 μg mL-1, LPS-treated experimental group significantly inhibited NO production in a dose-dependent manner. The dose-response trends followed quadratic regressions in all PG varieties. The PG extracts showed a considerable range of influence on cytokine secretion. The effect of adventitious root extracts of PG against inflammatory mediators TNF-α, IL-6 and IL-1β production showed the most significant anti-inflammatory activity.

Lipopolysaccharide Exposure Alleviates Asthma in Mice by Regulating Th1/Th2 and Treg/Th17 Balance.

BackgroundIt is generally believed that endotoxin exposure exacerbates risk of developing asthmatic symptoms. However, recent studies have indicated that prior bacterial exposure may prevent future symptoms of asthma. Here, we evaluated the influence of pre-exposure to different concentrations of lipopolysaccharide (LPS) to subsequent ovalbumin (OVA) allergen sensitization and challenge.Material/MethodsFour-week-old Balb/c mice were treated intranasally with varying concentrations of LPS (1 ug, 10 ug, and 100 ug) or sterile PBS for 10 days, then 2 weeks later they were exposed to OVA. Both the molecular and functional airway responses to OVA administration were assessed following prior exposure to different doses of LPS or controls. Additionally, the Th1/Th2 and Treg/Th17 balance was measured.ResultsAirway responsiveness and immune cell recruitment in the bronchoalveolar lavage (BALF) were decreased in animals exposed to a low dose of LPS (1 ug) treatment compared with the asthma group. Moderate-dose (10 ug) and high-dose (100 ug) LPS administration showed no differences from controls. Further, low-dose LPS (1 ug) exposure was associated with increased Th1 cytokines, T-bet, Treg cytokine (IL-10, TGF-β), and Foxp3 expression, but decreased Th2 cytokines (IL-4,5,13), GATA3, Th17, and ROR-γt expression compared with the asthma group. Finally, higher numbers of CD4+CD25+Foxp3+Treg cells, and CD4+INF-γ+T cells, and lower CD4+IL-4+T cells and CD4+IL-17+T cells were observed in the low-dose LPS-treated groups compared to controls.ConclusionsOur findings suggest that prior exposure to low doses of LPS may protect from OVA-induced airway hyperresponsiveness (AHR) and histopathologic changes through regulation of the Th1/Th2 and Treg/Th17 balance.

Evaluation of Brain Nuclear Medicine Imaging Tracers in a Murine Model of Sepsis-Associated Encephalopathy

PurposeThe purpose of this study was to evaluate a set of widely used nuclear medicine imaging agents as possible methods to study the early effects of systemic inflammation on the living brain in a mouse model of sepsis-associated encephalopathy (SAE). The lipopolysaccharide (LPS)-induced murine systemic inflammation model was selected as a model of SAE.ProceduresC57BL/6 mice were used. A multimodal imaging protocol was carried out on each animal 4 h following the intravenous administration of LPS using the following tracers: [99mTc][2,2-dimethyl-3-[(3E)-3-oxidoiminobutan-2-yl]azanidylpropyl]-[(3E)-3-hydroxyiminobutan-2-yl]azanide ([99mTc]HMPAO) and ethyl-7-[125I]iodo-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate ([125I]iomazenil) to measure brain perfusion and neuronal damage, respectively; 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) to measure cerebral glucose uptake. We assessed microglia activity on another group of mice using 2-[6-chloro-2-(4-[125I]iodophenyl)-imidazo[1,2-a]pyridin-3-yl]-N-ethyl-N-methyl-acetamide ([125I]CLINME). Radiotracer uptakes were measured in different brain regions and correlated. Microglia activity was also assessed using immunohistochemistry. Brain glutathione levels were measured to investigate oxidative stress.ResultsSignificantly reduced perfusion values and significantly enhanced [18F]FDG and [125I]CLINME uptake was measured in the LPS-treated group. Following perfusion compensation, enhanced [125I]iomazenil uptake was measured in the LPS-treated group’s hippocampus and cerebellum. In this group, both [18F]FDG and [125I]iomazenil uptake showed highly negative correlation to perfusion measured with ([99mTc]HMPAO uptake in all brain regions. No significant differences were detected in brain glutathione levels between the groups. The CD45 and P2Y12 double-labeling immunohistochemistry showed widespread microglia activation in the LPS-treated group.ConclusionsOur results suggest that [125I]CLINME and [99mTc]HMPAO SPECT can be used to detect microglia activation and brain hypoperfusion, respectively, in the early phase (4 h post injection) of systemic inflammation. We suspect that the enhancement of [18F]FDG and [125I]iomazenil uptake in the LPS-treated group does not necessarily reflect neural hypermetabolism and the lack of neuronal damage. They are most likely caused by processes emerging during neuroinflammation, e.g., microglia activation and/or immune cell infiltration.

Comparision of the Effects of Leishmania Soluble Antigen (LSA) and Lipopolysaccharide (LPS) on C57BL/6 Mice Macrophage Function

Background Macrophages activation is the important anti-leishmania immune response. Different signals could affect macrophages development and functional activation. In the present study, we compared the effect of Leishmania Soluble Antigen (LSA) and Lipopolysaccharide (LPS) on peritoneal macrophage responses. Appropriate activation of macrophages depends on the signals they receive from pathogens and their different functional differentiation is crucial for anti-leishmania effects of macrophages. Materials and Methods In order to assay C57BL/6 mice macrophage function after LPS or LSA treatment, we measured phagocytic activity, cytokine pattern, and Nitric Oxide (NO) production by macrophages. Results Phase contrast microscopy showed that LPS-treated macrophages became more granular and spindle-shaped and similar to untreated macrophages, LSA-treated cells displayed round and spindle-shaped morphology. In addition, Nitric oxide assay and cytokine analysis showed that IL-6, IL-10, and TNF-α production was significantly reduced in LSA-treated macrophages in comparison with LPS-stimulated cells. It was also found that LSA-treated macrophages represented an anti-inflammatory phenotype compared with LPS-treated macrophages. Conclusion This anti-inflammatory phenotype was related to increase in IL-10/TNF- α production of LSA-treated macrophages and there was no difference in the amount of TGF-β between LSA- and LPS-treated groups.

The pre-protective effect of vitamin A on LPS-induced oxidative stress of bovine mammary epithelial cells

All-trans retinoic acid (RA, derivative of vitamin A) has been demonstrated to have anti-oxidative activity and is needed for the proper function of the immune system. In this study, the protective effects of RA against lipopolysaccharide (LPS)-induced oxidative stress on bovine mammary epithelial cells (BMECs) have been investigated. BMECs were divided into four equal groups with six replicates. The first group was used as a control without RA or LPS. The three experimental groups were treated with RA (1 μg/mL) alone, LPS (1 μg/mL) alone and RA plus LPS, respectively. The cells were treated for 30 h in all. Our results showed that cells in LPS-treated group have a significantly higher inflammatory cytokines concentration and NF-κBp50 and NF-κBp65 gene expression than the control (p < .01). Furthermore, compared with control, selenoproteins’ activity of glutathione peroxidase (GPx), thioredoxin reductase (TrxR), the concentration of SelP and the gene expression of Nrf2 were significantly decreased while the activity of inducible nitric oxide synthase (iNOS), the production of intracellular reactive oxygen species (ROS) and malonaldehyde (MDA) were elevated dramatically in LPS-treated group (p < .01). However, RA in combination with LPS enhanced the antioxidant enzyme activities of selenoprotein compared to LPS-treated group. In conclusion, RA ameliorated the LPS-induced BMECs damage by improving levels of antioxidant markers and reducing inflammatory cytokines contents, indicating that RA has the potential to counter measure the immunosuppressive condition on BMECs oxidative damage and to improve antioxidative function. However, further studies are still required to elucidate the molecular mechanisms underlying the protective effects of RA as an antioxidant.

Lipopolysaccharide Prompts Oxidative Stress and Apoptosis in Rats’ Testicular Tissue

Lipopolysaccharide (LPS) is a component of the outer membrane of gram negative bacteria. LPS challenging allows switching transcription of proinflammatory cytokines on via over stimulation of Toll-like receptors (TLRs) signaling pathway with subsequent pathogenic inflammatory response. We investigated the possible reproductive toxicity of LPS in male Wister albino rats. Oxidative stress markers, antioxidant status and caspase-3 activity were analyzed in testicular tissues of rats exposed to either saline or LPS (4 mg/kg BW, ip; 0.18 of the LD50). The samples were collected at 6 h and 72 h after injection of LPS. A significant reduction in testicular reduced glutathione (GSH), glutathione-S-transferase (GST) and superoxide dismutase (SOD) was observed at 72 h compared to control group. Total antioxidant capacity was decreased at 6 h with additional significant reduction at 72 h. Catalase activity was reduced significantly at both 6 and 72 h. Malondialdehyde (MDA) was increased (P ≤ 0.05) in LPS injected rats without variation between 6 and 72 h. A significant increase in nitric oxide (NO) was observed at 72 h after injection. A time-dependent increase in LPS-treated groups was observed in the concentration of caspase-3.Histopathological analysis revealed degenerative changes and necrosis of seminiferous tubules after 6 h with further accumulation of eosinophilic edematous transudate in its lumen after 72 h. In conclusion, by increasing time of exposure, LPS induced lipid peroxidation, oxidative stress, reduced testicular antioxidant capacity and encouraged testicular apoptosis which could be possible mechanisms for impairment of testicular function.

Fisetin administration improves LPS-induced acute otitis media in mouse in vivo.

Acute otitis media is one of the most common infectious diseases worldwide in spite of the widespread vaccination. The present study was conducted to explore the effects of fisetin on mouse acute otitis media models. The animal models were established by lipopolysaccharide (LPS) injection into the middle ear of mice via the tympanic membrane. Fisetin was administered to mice for ten days through intragastric administration immediate after LPS application. Hematoxylin and eosin (H&E) staining was performed and the pro-inflammatory cytokines, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), IL-6 and VEGF, were measured through enzyme-linked immunosorbent assay (ELISA) method and RT-qPCR analysis. Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway was detected by immunoblotting assays. Reactive oxygen species (ROS) generated levels were determined through assessment of anti-oxidants, and TXNIP/MAPKs signaling pathways were explored to reveal the possible molecular mechanism for acute otitis media progression and the function of fisetin. Fisetin reduced mucosal thickness caused by LPS. In fisetin-treated animals, pro-inflammatory cytokine release was downregulated accompanied with TLR4/NF-κB inactivation. ROS production was significantly decreased in comparison to the LPS-treated group. The TXNIP/MAPKs signaling pathway was inactivated for fisetin treatment in LPS-induced mice with acute otitis media. The above results indicated that fisetin improved acute otitis media through inflammation and ROS suppression via inactivating TLR4/NF-κB and TXNIP/MAPKs signaling pathways.

Cardiac and renal fibrosis and oxidative stress balance in lipopolysaccharide-induced inflammation in male rats.

BACKGROUNDSubclinical inflammation induced by persistent exposure to lipopolysaccharide (LPS) is found in some clinical conditions such as obesity or diabetes. This study aimed to investigate the effect of recurrent LPS exposure on inflammatory markers, oxidative stress balance and cardiac and renal fibrosis in male rats.METHODSMale Wistar rats were divided into control and LPS-treated. LPS (10 mg/kg/week) was injected intraperitoneally. After 4 weeks, left ventricles and kidneys were homogenized and stained with hematoxylin and eosin (H&E) and Masson trichrome for histological examination. Serum levels of nitrite, interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) were measured and total thiol, malondialdehyde (MDA), superoxide dismutase (SOD) and catalase were evaluated in the heart and kidney homogenates.RESULTSSerum inflammatory markers were higher in LPS group than control (nitrite: 37.0 ± 2.2 vs. 25.5 ± 1.9 µmol/l; IL-6: 84 ± 3 vs. 98.0 ± 4.4 pg/ml; TNF-α: 75.5 ± 4.9 vs. 85.3 ± 4.7 pg/ml; respectively, P < 0.050). Evaluation of total thiol concentration (heart: 10.0 ± 0.9 vs. 22.5 ± 1.2; kidney: 7.0 ± 0.5 vs. 27.8 ± 3.1 nmol/g tissue, respectively), catalase (heart: 0.18 ± 0.03 vs. 0.66 ± 0.04; kidney: 0.17 ± 0.03 vs. 0.73 ± 0.03, U/g tissue, respectively) and SOD (heart: 8.01 ± 0.70 vs. 12.3 ± 0.4; kidney: 7.02 ± 0.60 vs. 12.0 ± 0.2, U/g tissue, respectively) showed lower levels in LPS-treated group compared to control; while MDA concentration in LPS group was higher than control (P < 0.05). Histopathological examination in LPS-treated group indicated infiltration of inflammatory cells and more collagen deposition in left ventricle wall and kidney compared to control group.CONCLUSIONWe concluded that in clinical conditions with chronic LPS, cardiac and renal fibrosis occurs even in absence of preceding tissue injury due to imbalances in oxidative stress.

Low-Intensity Pulsed Ultrasound Attenuates LPS-Induced Neuroinflammation and Memory Impairment by Modulation of TLR4/NF-κB Signaling and CREB/BDNF Expression.

The purpose of this study was to investigate the restorative role of low-intensity pulsed ultrasound (LIPUS) against lipopolysaccharide (LPS)-induced neuroinflammation and memory impairments in a simulation of Alzheimer's disease. Mice subjected to LPS administration (250 μg/kg, i.p.) were treated with LIPUS daily for 7 days. The levels of brain-derived neurotrophic factor (BDNF) and inflammatory markers were estimated in brain tissue using western blot. After LIPUS treatment, the neuroprotective effects of LIPUS in mice were assessed by behavioral tests. LPS plus LIPUS-treated mice exhibited a significant increase in the average time spent in the target quadrant compared to the LPS-treated group. Compared with the LPS-treated group, LPS plus LIPUS-treated mice revealed a preference for the novel object. LIPUS treatment significantly attenuated LPS-induced increases in the expression of amyloid-beta (Aβ) and amyloid precursor protein (APP) in the hippocampus region of LPS-treated mice. Furthermore, LIPUS significantly reduced the protein levels of TNF-α, IL-1β, and IL-6 in the mice brain induced by LPS. LIPUS treatment induces neuroprotection by inhibiting the LPS-induced activation of TLR4/NF-κB inflammatory signaling and by enhancing the associated CREB/BDNF expression in LPS-treated mice. Our data showed that LIPUS attenuated LPS-induced memory impairment as well as amyloidogenesis via the suppression of neuroinflammatory activity and BDNF decline.

AMPK/Nrf2 signaling is involved in the anti-neuroinflammatory action of Petatewalide B from Petasites japonicus against lipopolysaccharides in microglia

Objectives: Abnormal microglia secrete neuroinflammatory factors that play a pivotal role in neurodegenerative-disorder development. Thus, regulating abnormal microglia-activation could be a promising therapeutic strategy. The purposes of this study included investigating the effect of Petatewalide B on lipopolysaccharide- (LPS-) stimulated microglia and exploring the role of the AMPK/Nrf2- (adenosine monophosphate-activated protein kinase/nuclear factor erythroid 2-related factor 2) signaling pathway in the anti-neuroinflammatory function of Petatewalide B.Methods: We divided the microglia into four groups: a control group, a Petatewalide B-treated group, an LPS-treated group, and an LPS and Petatewalide B-treated group. The four groups of microglia were experimented with, using the NO, ELISA, and promoter assays, and western blotting was conducted to determine LPS-stimulated neuroinflammatory responses.Results: We found that pretreatment with Petatewalide B strongly alleviates interleukin- (IL-) 1β, IL-6, and tumor-necrosis-factor-α (TNF-α) production, and suppresses iNOS and nitric oxide (NO) overexpression in LPS-stimulated microglia. The AMPK/Nrf2-signaling pathway is important for inducing anti-neuroinflammatory responses. Mechanistic studies report that Petatewalide B increases nuclear-Nrf2 translocation, and heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1) expression in a dose-dependent manner. Furthermore, Petatewalide B significantly up-regulates HO-1 and NQO1 by specifically improving antioxidant-response-elements-transcription activity. We then investigated whether Nrf2/HO-1/NQO1 contribute to the anti-neuroinflammatory properties of Petatewalide B. Nrf2, HO-1, and NQO1 small-integrating-ribonucleic-acids (siRNAs) significantly blocked Petatewalide B-attenuated iNOS-promoter-activity in LPS-stimulated microglia. Furthermore, Petatewalide B also up-regulated AMPK-phosphorylation in a dose-dependent manner. We next evaluated whether blocking AMPK-phosphorylation using an inhibitor (compound C) would critically affect anti-neuroinflammatory responses. We found that the AMPK-phosphorylation is associated with nuclear-Nrf2 translocation and elevated HO-1 and NQO1 expression levels. Our data also showed that AMPK-inhibitor pretreatment significantly reverses Petatewalide B-attenuated iNOS-promoter-activity in LPS-stimulated microglia.Conclusions: Our findings provide the possible mechanism of the anti-neuroinflammatory properties of Petatewalide B that result from beneficial responses in the AMPK/Nrf2-signaling pathway.

Myocardial strain/stress changes identified by echocardiography may reveal early sepsis-induced myocardial dysfunction.

ObjectiveTo perform early assessment of sepsis-induced myocardial dysfunction (SIMD) using strain/stress echocardiography.MethodsA canine model of SIMD was established using intravenous injection of lipopolysaccharide (LPS, 2 mg/kg). Thirteen dogs were included, comprising an LPS-treated SIMD group (n = 7) and saline control group (n = 6). SIMD was assessed at various time-points using cardiac measurements including haemodynamics and echocardiography.ResultsSystolic and radial ventricular wall stress and circular ventricular wall stress (WSsc) were significantly lower in the sepsis group versus the control group at all time-points. Logistic regression analysis revealed an inverse correlation between stress rate of the front-posterior and bottom wall and left ventricle systolic wall strength. In contrast, a positive correlation was found between the mean velocity of circumferential fibre shortening (mVCF) or heart rate-adjusted mVCF (RVCF) and WSsc. Using regression equations, predicted values for mVCF and RVCF in animals with sepsis were significantly higher than measured values at 4- 5- and 6-h time-points.ConclusionsThese findings will further the understanding of pathophysiological alterations in SIMD at the early stage of sepsis, and suggest that strain rate may reflect the nature of myocardial contractility.

Involvement of Gas6 protein in mouse model of lipopolysaccharide-induced lung inflammation

Background: Gas6 is a product of growth arrest-specific gene 6 and is mostly expressed by the growth-arrested organs and is implicated in thrombosis, various inflammation, and age-related diseases. However, its role in chronic obstructive pulmonary disease has not been investigated yet. Methods: We developed lipopolysaccharide-induced mouse model of chronic lung inflammation to study its involvement. Therefore, male C57BL/6 mice (20–25 g) were grouped into control and LPS group; each group having 15 animals each. LPS group was nebulized with LPS (1 mg/ml) for 45 min, once a week for 8 weeks to induce chronic inflammatory conditions in the lungs by use of nebulizer. The mice model was validated by assessing infiltration of various immune cells (T-cells, B-cells, and neutrophils) into the lungs and pro-inflammatory and anti-inflammatory cytokine profile by cytokine bead array kit by flow cytometry. Lung deterioration was assessed by lung histology. The level of gas6 protein from the lung homogenate was measured by quantikine enzyme-linked immunosorbent assay kit. Furthermore, lung homogenate was analyzed by Western blotting for expression profile of gas6 protein. Results: There was significant increase in the level of T-cells (19±8% vs 65±11%), B-cells (24±7% vs 64±10%), and neutrophils (22±9% vs 57±10%) and significant increase in the level of tumor necrosis factor (200 ± 17 pg/ml vs. 1222 ± 152 pg/ml) and IL-6 (106 ± 13 pg/ml vs. 448 ± 122 pg/ml). Lung deterioration was observed in LPS group. We observed significant increase in the level of gas6 protein in lung homogenate in LPS group (0.16 ± 0.1 ng/ml vs. 4.2 ± 0.1 ng/ml). Furthermore, we found significant increase in gas6 protein in the lung homogenate of LPS-treated group by Western blotting. Conclusion: The current study establishes the involvement gas6 protein in lung inflammation.