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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Quince (Cydonia oblonga Miller) peel polyphenols modulate LPS-induced inflammation in human THP-1-derived macrophages through NF-{kappa}B, p38MAPK and Akt inhibition

Highlights: Black-Right-Pointing-Pointer Quince peel polyphenols inhibit LPS-induced secretion of TNF-{alpha} and IL-8. Black-Right-Pointing-Pointer Quince peel polyphenols augment LPS-induced secretion of IL-10 and IL-6. Black-Right-Pointing-Pointer Quince peel polyphenols-mediated inhibition of LPS-induced secretion of TNF-{alpha} is partially mediated by IL-6. Black-Right-Pointing-Pointer The anti-inflammatory effects of quince polyphenols pass through NF-{kappa}B, p38MAPK and Akt inhibition. -- Abstract: Chronic inflammation is a hallmark of several pathologies, such as rheumatoid arthritis, gastritis, inflammatory bowel disease, atherosclerosis and cancer. A wide range of anti-inflammatory chemicals have been used to treat such diseases while presenting high toxicity and numerous side effects. Here, we report the anti-inflammatory effect of a non-toxic, cost-effective natural agent, polyphenolic extract from the Tunisian quince Cydonia oblonga Miller. Lipopolysaccharide (LPS) treatment of human THP-1-derived macrophages induced the secretion of high levels of the pro-inflammatory cytokine TNF-{alpha} and the chemokine IL-8, which was inhibited by quince peel polyphenolic extract in a dose-dependent manner. Concomitantly, quince polyphenols enhanced the level of the anti-inflammatory cytokine IL-10 secreted by LPS-treated macrophages. We further demonstrated that the unexpected increase in IL-6 secretion that occurred when quince polyphenols were associated with LPS treatment was partially responsible for the polyphenols-mediated inhibition of TNF-{alpha} secretion. Biochemical analysis showed that quince polyphenols extract inhibited the LPS-mediated activation of three major cellular pro-inflammatory effectors, nuclear factor-kappa B (NF-{kappa}B), p38MAPK and Akt. Overall, our data indicate that quince peel polyphenolic extract induces a potent anti-inflammatory effect that may prove useful for the treatment of inflammatory diseases and that a quince-rich regimen may help to prevent and improve the treatment of such diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2012

TNF{alpha} and IL-1{beta} are mediated by both TLR4 and Nod1 pathways in the cultured HAPI cells stimulated by LPS

Highlights: Black-Right-Pointing-Pointer LPS induces proinflammatory cytokine release in HAPI cells. Black-Right-Pointing-Pointer JNK pathway is dependent on TLR4 signaling to release cytokines. Black-Right-Pointing-Pointer NF-{kappa}B pathway is dependent on Nod1 signaling to release cytokines. -- Abstract: A growing body of evidence recently suggests that glial cell activation plays an important role in several neurodegenerative diseases and neuropathic pain. Microglia in the central nervous system express toll-like receptor 4 (TLR4) that is traditionally accepted as the primary receptor of lipopolysaccharide (LPS). LPS activates TLR4 signaling pathways to induce the production of proinflammatory molecules. In the present studies, we verified the LPS signaling pathways using cultured highly aggressively proliferating immortalized (HAPI) microglial cells. We found that HAPI cells treated with LPS upregulated the expression of TLR4, phospho-JNK (pJNK) and phospho-NF-{kappa}B (pNF-{kappa}B), TNF{alpha} and IL-1{beta}. Silencing TLR4 with siRNA reduced the expression of pJNK, TNF{alpha} and IL-1{beta}, but not pNF-{kappa}B in the cells. Inhibition of JNK with SP600125 (a JNK inhibitor) decreased the expression of TNF{alpha} and IL-1{beta}. Unexpectedly, we found that inhibition of Nod1 with ML130 significantly reduced the expression of pNF-{kappa}B. Inhibition of NF-{kappa}B also reduced the expression of TNF{alpha} and IL-1{beta}. Nod1 ligand, DAP induced the upregulation of pNF-{kappa}B which was blocked by Nod1 inhibitor. These data indicate that LPS-induced pJNK is TLR4-dependent, and that pNF-{kappa}B is Nod1-dependent in HAPI cells treated with LPS. Either TLR4-JNK or Nod1-NF-{kappa}B pathways is involved in the expression of TNF{alpha} and IL-1{beta}.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

CXC195 suppresses proliferation and inflammatory response in LPS-induced human hepatocellular carcinoma cells via regulating TLR4-MyD88-TAK1-mediated NF-κB and MAPK pathway

Highlights: • CXC195 exhibited significant anti-proliferative effect and induced cell cycle arrest in LPS-induced HepG2 cells. • CXC195 suppressed the release of pro-inflammatory mediators in LPS-induced HepG2 cells. • CXC195 regulated TLR4-MyD88-TAK1-mediated NF-κB and MAPK pathway in LPS-induced HepG2 cells. - Abstract: CXC195 showed strong protective effects in neuronal apoptosis by exerting its antioxidant activity. However, the anti-cancer effects of CXC195 is still with limited acquaintance. Here, we investigated the role of CXC195 in lipopolysaccharide (LPS)-induced human hepatocellular carcinoma (HCC) cells lines (HepG2) and the possible signaling pathways. CXC195 exhibited significant anti-proliferative effect and induced cell cycle arrest in LPS-induced HepG2 cells. In addition, CXC195 suppressed the release of pro-inflammatory mediators in LPS-induced HepG2 cells, including TNF-α, iNOS, IL-1β, IL-6, CC chemokine ligand (CCL)-2, CCL-22 and epidermal growth factor receptor (EGFR). Moreover, CXC195 inhibited the expressions and interactions of TLR4, MyD88 and TAK1, NF-κB translocation to nucleus and its DNA binding activity, phosphorylation of ERK1/2, p38 and JNK. Our results suggested that treatment with CXC195 could attenuate the TLR4-mediated proliferation and inflammatory response in LPS-induced HepG2 cells, thus might be beneficial for the treatment of HCC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Tyrosine kinase Fyn regulates iNOS expression in LPS-stimulated astrocytes via modulation of ERK phosphorylation

Highlights: • Fyn regulates LPS-induced iNOS expression in the cortices. • Fyn modulates iNOS expression and nitrite levels in LPS-stimulated astrocytes. • Fyn regulates iNOS expression in LPS-stimulated astrocytes via ERK phosphorylation. The high concentrations of nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) in activated glial cells in response to neuroinflammatory stimuli have neurotoxic effects on the brain. At basal levels, iNOS expression is low, and proinflammatory stimuli induce iNOS expression in astrocytes, microglia, and oligodendrocytes. Fyn, a non-receptor tyrosine kinase, regulates iNOS expression in several types of immune cells. However, its role in stimulated astrocytes is less clear. In this study, we investigated the role of Fyn in the regulation of lipopolysaccharide (LPS)-induced iNOS expression in astrocytes from mice and rats. Intracerebroventricular LPS injections in cortical regions enhanced iNOS mRNA and protein levels, which were increased in Fyn-deficient mice. Accordingly, LPS-induced nitrite production was enhanced in primary astrocytes cultured from Fyn-deficient mice or rats. Similar results were observed in cultured astrocytes after the siRNA-induced knockdown of Fyn expression. Finally, we observed increased LPS-induced extracellular signal-regulated protein kinase (ERK) activation in Fyn-deficient astrocytes. These results suggested that Fyn has a regulatory role in iNOS expression in astrocytes during neuroinflammatory responses.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Friedelane-type triterpenoids as selective anti-inflammatory agents by regulation of differential signaling pathways in LPS-stimulated macrophages

A series of 31 pentacyclic triterpenoids isolated from the root barks of Celastrus vulcanicola and Maytenus jelskii were tested for cytotoxicity and inhibitory activity against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 macrophages. Compounds 18 (C18) and 25 (C25) exhibited significant inhibition of LPS-induced NO release at 50 and 25 μM concentrations, respectively, and decreased mRNAs of pro-inflammatory cytokines. At the molecular level, C18 neither inhibited LPS-mediated phosphorylation of mitogen activated protein kinases (MAPKs) nor nuclear translocation of nuclear factor kappa beta (NFκB). Instead, C18 enhanced and prolonged nuclear translocation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and increased the expression of its target genes including hemeoxigenase 1 (HO1). C25 efficiently inhibited LPS-mediated phosphorylation of JNK, p38 and ERK, without affecting NFκB or Nrf2 signaling pathways. Both compounds reduced LPS-mediated processing of caspase-1 and the cleavage of interleukin 1β (IL1β) proform, reflecting their ability to target the inflammasome. C25 also counteracted LPS effects on iNOS expression and pro-inflammatory cytokines mRNA levels in Bv-2 microglial cells. The anti-inflammatory effect of both compounds was also assessed in human macrophages. Our results suggest that triterpenoids C18 and C25 possess anti-inflammatory effects, which may be therapeutically relevant for diseases linked to inflammation. - Highlights: • Compounds 18 (C18) and 25 (C25) exert anti-inflammatory effects in macrophages. • C18 enhanced nuclear translocation of Nrf2 and increased HO1 expression. • C25 inhibited the phosphorylation of JNK, p38 and ERK, members of the MAPKs family. • C25 reduced LPS-mediated processing of caspase-1 and the cleavage of interleukin 1β. • C18 and C25 may be therapeutic agents for diseases linked to inflammation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2020

LPS-Induced Inflammation Prior to Injury Exacerbates the Development of Post-Traumatic Osteoarthritis in Mice

ABSTRACT Osteoarthritis (OA) is a debilitating and painful disease characterized by the progressive loss of articular cartilage. Post-traumatic osteoarthritis (PTOA) is an injury-induced type of OA that persists in an asymptomatic phase for years before it becomes diagnosed in ~50% of injured individuals. Although PTOA is not classified as an inflammatory disease, it has been suggested that inflammation could be a major driver of PTOA development. Here we examined whether a state of systemic inflammation induced by lipopolysaccharide (LPS) administration 5-days before injury would modulate PTOA outcomes. RNA-seq analysis at 1-day post-injury followed by micro-computed tomography (μCT) and histology characterization at 6 weeks post-injury revealed that LPS administration causes more severe PTOA phenotypes. These phenotypes included significantly higher loss of cartilage and subchondral bone volume. Gene expression analysis showed that LPS alone induced a large cohort of inflammatory genes previously shown to be elevated in synovial M1 macrophages of rheumatoid arthritis (RA) patients, suggesting that systemic LPS produces synovitis. This synovitis was sufficient to promote PTOA in MRL/MpJ mice, a strain previously shown to be resistant to PTOA. The synovium of LPS-treated injured joints displayed an increase in cellularity, and immunohistological examination confirmed that this increase was in part attributable to an elevation in type 1 macrophages. LPS induced the expression of Tlr7 and Tlr8 in both injured and uninjured joints, genes known to be elevated in RA. We conclude that inflammation before injury is an important risk factor for the development of PTOA and that correlating patient serum endotoxin levels or their state of systemic inflammation with PTOA progression may help develop new, effective treatments to lower the rate of PTOA in injured individuals. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2017

1, 25(OH){sub 2}D{sub 3}-induced interaction of vitamin D receptor with p50 subunit of NF-κB suppresses the interaction between KLF5 and p50, contributing to inhibition of LPS-induced macrophage proliferation

KLF5 and nuclear factor κB (NF-κB) regulate cell proliferation and inflammation. Vitamin D signaling through vitamin D receptor (VDR) exerts anti-proliferative and anti-inflammatory actions. However, an actual relationship between KLF5, NF-κB and VDR in the inflammation and proliferation of macrophages is still unclear. Here, we showed that LPS and proinflammatory cytokines stimulate KLF5 gene expression in macrophages, and that 1, 25(OH){sub 2}D{sub 3} suppresses LPS-induced KLF5 expression and cell proliferation via upregulation of VDR expression. Mechanistic studies suggested that KLF5 interacts with p50 subunit of NF-κB to cooperatively induce the expressions of positive cell cycle regulators cyclin B1 and Cdk1/Cdc2 in LPS-treated macrophages. Further studies revealed that 1, 25(OH){sub 2}D{sub 3}-induced interaction of VDR with p50 decreases LPS-induced interaction of KLF5 with p50. Collectively, we identify a novel regulatory pathway in which 1, 25(OH){sub 2}D{sub 3} induces VDR expression and promotes VDR interaction with p50 subunit of NF-κB, which in turn attenuates the association of KLF5 with p50 subunit of NF-κB and thus exerts anti-inflammatory and anti-proliferative effects on macrophages. - Highlights: • 1, 25(OH){sub 2}D{sub 3} suppresses LPS-induced KLF5 expression via upregulation of VDR expression. • KLF5 interacts with NF-κB-p50 to cooperatively induce the expressions of positive cell cycle regulators cyclin B1 and Cdk1/Cdc2 in LPS-treated macrophages. • 1,25(OH){sub 2}D{sub 3} induces interaction of VDR with p50.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

The regulation of Jmjd3 upon the expression of NF-κB downstream inflammatory genes in LPS activated vascular endothelial cells

Inflammatory mediators and adhesion molecules have been implicated in a variety of diseases including atherosclerosis. As both the mediator-releasing and targeted cells, vascular endothelial cells play key role in pathological processes. NF-κB signaling regulates a cluster of inflammatory factors in LPS-activated vascular endothelial cells but the underlying mechanisms remain largely unknown. Here, we investigated the epigenetic regulation of LPS upon the expression of inflammatory mediators and adhesion molecules. We found that LPS treatment promoted jmjd3 expression, enhanced Jmjd3 nuclear accumulation in human vascular endothelial cells. In addition, LPS enhanced the demethylation of H3K27me3, a specific substrate of Jmjd3. LPS treatment recruited Jmjd3 and NF-κB to the promoter region of target genes, suggesting Jmjd3 synergizes with NF-κB to activate the expression of target genes. We further found that Jmjd3 attenuated the methylation status in promoter region of target genes, culminating in target gene expression. Our findings unveil epigenetic regulations of LPS upon NF-κB pathway and identify Jmjd3 as a critical modulator of NF-κB pathway and potential therapeutic target for NF-κB related diseases including atherosclerosis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Sirt1 S-nitrosylation induces acetylation of HMGB1 in LPS-activated RAW264.7 cells and endotoxemic mice

Highlights: • S-nitrosylation of SIRT1 (SNO-SIRT1) by NO resulted in HMGB1 release in LPS-activated RAW264.7 cells. • The iNOS inhibitor (1400 W) and si-iNOS significantly inhibited SNO-SIRT1, which decreased the HMGB1 release by LPS. • The levels of SNO-SIRT were significantly increased in LPS-injected mice lung, which was inhibited by 1400 W treatment. • The SNO-SIRT1 under endotoxic conditions may uninhibit the acetylation of HMGB1 and its extracellular release. Excessive inflammation plays a detrimental role in endotoxemia. A recent study indicated that alarmins such as high mobility group box 1 (HMGB1) have drawn attention as therapeutic targets of sepsis. Post-translational modification (i.e., acetylation of lysine residues) of HMGB1 leads to the release of HMGB1 into the cellular space, operating as a warning signal that induces inflammation. Sirtuin 1 (SIRT1) has been shown to negatively regulate HMGB1 hyperacetylation and its extracellular release in sepsis. Therefore, we hypothesized that the S-nitrosylation (SNO) of SIRT1 may disrupt the ability of SIRT1 to negatively regulate the hyperacetylation of HMGB1. As long as the S-nitrosylation of SIRT1 occurs during septic conditions, it may worsen the situation. We found that the activity of SIRT1 decreased as the SNO-SIRT1 levels increased, resulting in HMGB1 release by LPS in RAW264.7 cells. Both the iNOS inhibitor (1400 W) and silencing iNOS significantly inhibited SNO-SIRT1, allowing increases in SIRT1 activity that decreased the HMGB1 release by LPS. SNAP, a NO donor, significantly increased both SNO-SIRT1 levels and the HMGB1 release that was accompanied by decreased sirt1 activity. However, sirtinol, a Sirt1 inhibitor, by itself decreased Sirt1 activity compared to that of the control, so that it did not affect already increased SNO-SIRT levels by SNAP. Most importantly, in lung tissues of LPS-endotoxic mice, significantly increased levels of SNO-SIRT were found, which was inhibited by 1400 W treatment. Plasma nitrite and HMGB1 levels were significantly higher than those in the sham controls, and the elevated levels were significantly lowered in the presence of 1400 W. We concluded that the S-nitrosylation of Sirt1 under endotoxic conditions may uninhibit the acetylation of HMGB1 and its extracellular release.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Shikonin exerts anti-inflammatory effects in LPS-induced mastitis by inhibiting NF-κB signaling pathway

Highlights: • Myeloperoxidase decreased when shikonin was given by gavage in LPS-induced mammary gland tissues. • Nuclear factor-κB was inhibited in SHI group both in tissues and cells, comparing with groups challenged by LPS. • SHI exerts less pro-inflammatory cytokines than LPS-challenged group, indicating the potential for mastitis treatment. Previous studies have shown that shikonin(SHI), the bioactive naphthoquinone constituent extracted from Chinese herb Lithospermum Erythrorhizon, possesses the potential to confront inflammation, and has little concerns towards drug residues comparing with antibiotics. While mastitis in dairy industry always trigger great harm to milk yields, effects of SHI on lipopolysaccharides (LPS)-induced mastitis should be measured. Here, we demonstrate anti-inflammatory effects of SHI on LPS-challenged mastitis and elucidate the potential signaling pathway both in vivo and in vitro. As a result, SHI administration mice significantly suffered less impairment of mammary gland and less recruitment of neutrophils than LPS administration mice. SHI significantly suppressed the expression of p-IκBα and p-p65, which are the critical proteins functioning in NF-kB signaling pathway. qPCR results indicate decreasing level of upstream pro-inflammatory cytokines in tissues, such as TNF-α, IL-1β, and IL-6. The results are corresponding with the results in vitro, suggesting the potential usage of SHI as a therapeutic medicine in mastitis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Retinoic acid modulates iron metabolism imbalance in anemia of inflammation induced by LPS via reversely regulating hepcidin and ferroportin expression

Highlights: • Anemia of inflammation (AI) model was induced by lipopolysaccharide in mouse. • Retinoic acid (RA) increases RBC, Hb, HCT, MCV, MCHC and EPO in AI model. • RA inhibits inflammation in AI model by decreasing TNF-α, IL-18 and IL-1β contents. • RA modulates iron metabolism imbalance in AI model. • RA reversely regulates hepcidin and ferroportin expression in AI model. The present study was designed to investigate the effect of retinoic acid (RA) on anemia of inflammation (AI) induced by lipopolysaccharide (LPS) and explore the potential mechanisms. BALB/c mice were randomly assigned into four groups: control group; LPS (10 mg/kg) group, LPS + RA (3 mg/kg) and LPS + RA (15 mg/kg) groups. Red blood cell count (RBC), hemoglobulin (Hb), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin contentration (MCHC), erythropoietin (EPO) and iron content in both serum and liver tissue were measured. The AI model induced by LPS was successfully established represented by the decreases in RBC, Hb, HCT, MCV, MCHC and EPO for anemia indicators and by the increases in TNF-α, IL-18 and IL-1β contents for inflammation indicators. However, supplementation of RA increased the levels of anemia indicators and decreased the content of inflammation indicators. In addition, RA increased the content of iron in serum, while decreased its content in liver tissue. Furthermore, RA down-regulated the protein expression of hepcidin, toll-like receptor 4 (TLR4) and p-p65 in liver tissue, while up-regulated that of ferroportin. RA modulates iron metabolism imbalance in AI induced by LPS via reversely regulating hepcidin and ferroportin expression, which might be mediated by TLT-4/NFκB signaling pathway.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

BQ-123 prevents LPS-induced preterm birth in mice via the induction of uterine and placental IL-10

Preterm birth (PTB), defined as any delivery occurring prior to the completion of 37 weeks' gestation, currently accounts for 11–12% of all births in the United States. Maternal genito-urinary infections account for up to 40% of all PTBS and induce a pro-inflammatory state in the host. The potent vasoconstrictor Endothelin-1 (ET-1) is known to be upregulated in the setting of infection, and elicits its effect by binding to the ET{sub A} receptor. We have previously shown that antagonism of the ET{sub A} receptor with BQ-123 is capable of preventing LPS-induced PTB in mice. We hypothesize that the administration of BQ-123 post LPS exposure will dismantle a positive feedback loop observed with pro-inflammatory cytokines upstream of ET-1. On GD 15.5, pregnant C57BL/6 mice were injected with PBS, LPS, BQ-123, or LPS + BQ-123. Changes at both the level of transcription and translation were observed in uterus and placenta in the ET-1 axis and in pro- and anti-inflammatory cytokines over the course of 12 h. We discovered that BQ-123, when administered 10 h post LPS, is capable of increasing production of uterine and placental Interleukin-10, causing a shift away from the pro-inflammatory state. We also observed that antagonism of the ET{sub A} receptor decreased IL-1β and TNFα in the placenta while also decreasing transcription of ET-1 in the uterus. Our results reinforce the role of ET-1 at the maternal fetal interface and highlight the potential benefit of ET{sub A} receptor blockade via the suppression of ET-1, and induction of a Th2 cytokine dominant state. - Highlights: • The pro-inflammatory response to LPS in the uterus and placenta is ET-1 dependent. • ET{sub A} blockade triggers up-regulation of IL-10 in uterus and placenta. • A positive feedback loop drives ET-1 expression in gestational tissue.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Analysis of migration rate and chemotaxis of human adipose-derived mesenchymal stem cells in response to LPS and LTA in vitro

Mesenchymal stem cells (MSC) are able to stimulate the regeneration of injured tissue. Since bacterial infections are common complications in wound healing, bacterial pathogens and their components come into direct contact with MSC. The interaction with bacterial structures influences the proliferation, differentiation and migratory activity of the MSC, which might be of relevance during regeneration. Studies on MSC migration in response to bacterial components have shown different results depending on the cell type. Here, we analyzed the migration rate and chemotaxis of human adipose-derived MSC (adMSC) in response to the basic cell-wall components lipopolysaccharide (LPS) of Gram-negative bacteria and lipoteichoic acid (LTA) of Gram-positive bacteria in vitro. To this end, we used transwell and scratch assays, as well as a specific chemotaxis assay combined with live-cell imaging. We found no significant influence of LPS or LTA on the migration rate of adMSC in transwell or scratch assays. Furthermore, in the µ-slide chemotaxis assay, the stimulation with LPS did not exert any chemotactic effect on adMSC. - Highlights: • LPS increased the release of IL-6 and IL-8 in adMSC significantly. • The migration rate of adMSC was not influenced by LPS or LTA. • LPS or LTA did not exert a chemotactic effect on adMSC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2010

LPS-induced NF-{kappa}B expression in THP-1Blue cells correlates with neopterin production and activity of indoleamine 2,3-dioxygenase

Research highlights: {yields} LPS induces NF-{kappa}B, neopterin formation and tryptophan degradation in THP-1 cells. {yields} Close dose- and time-dependent correlations exist between these biochemical events. {yields} Data provides some evidence for a parallel induction of them upon TLR stimulation. {yields} Results can be of considerable relevance also in vivo. -- Abstract: Neopterin production is induced in human monocyte-derived macrophages and dendritic cells upon stimulation with Th1-type cytokine interferon-{gamma} (IFN-{gamma}). In parallel, IFN-{gamma} induces the tryptophan-(trp)-degrading enzyme indoleamine 2,3-dioxygenase (IDO) and triggers the formation of reactive oxygen species (ROS). Translocation of the signal transduction element nuclear factor-{kappa}B (NF-{kappa}B) is induced by ROS and accelerates the pro-inflammatory response by activation of other pro-inflammatory pathways. Therefore, a close relationship between NF-{kappa}B expression, the production of neopterin and the degradation of trp can be assumed, although this has not been demonstrated so far. In the present in vitro study we compared the influence of lipopolysaccharide (LPS) on NF-{kappa}B activation, neopterin formation and the degradation of trp in THP-1Blue cells, which represent the human myelomonocytic cell line THP-1 stably transfected with an NF-{kappa}B inducible reporter system. In cells stimulated with LPS, a significant induction of NF-{kappa}B was observed, and this was paralleled by an increase of kynureunine (kyn) and neopterin concentrations and a decline of trp. The increase of the kyn to trp quotient indicates accelerated IDO activity. Higher LPS concentrations and longer incubation of cells were associated with higher activities of all three biochemical pathways and significant correlations existed between NF-{kappa}B activation, neopterin release and trp degradation (all p < 0.001). We conclude that there is a parallel induction of NF-{kappa}B, neopterin formation and trp degradation in monocytic THP-1 cells, which is elicited by pro-inflammatory triggers like LPS during innate immune responses.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2012

Inhibition of LPS binding to MD-2 co-receptor for suppressing TLR4-mediated expression of inflammatory cytokine by 1-dehydro-10-gingerdione from dietary ginger

Highlights: Black-Right-Pointing-Pointer 1-Dehydro-10-gingerdione (1D10G) from ginger inhibits LPS binding to MD-2. Black-Right-Pointing-Pointer 1D10G suppresses MyD88- or TRIF-dependent signaling in LPS-activated macrophages. Black-Right-Pointing-Pointer 1D10G down-regulates the expression of NF-{kappa}B-, AP1- or IRF3-target genes. Black-Right-Pointing-Pointer MD-2 is a molecular target in the anti-inflammatory action of 1D10G. -- Abstract: Myeloid differentiation protein 2 (MD-2) is a co-receptor of toll-like receptor 4 (TLR4) for innate immunity. Here, we delineated a new mechanism of 1-dehydro-10-gingerdione (1D10G), one of pungent isolates from ginger (Zingiber officinale), in the suppression of lipopolysaccharide (LPS)-induced gene expression of inflammatory cytokines. 1D10G inhibited LPS binding to MD-2 with higher affinity than gingerol and shogaol from dietary ginger. Moreover, 1D10G down-regulated TLR4-mediated expression of nuclear factor-{kappa}B (NF-{kappa}B) or activating protein 1 (AP1)-target genes such as tumor necrosis factor {alpha} (TNF-{alpha}) and interleukin-1{beta}, as well as those of interferon (IFN) regulatory factor 3 (IRF3)-target IFN-{beta} gene and IFN-{gamma} inducible protein 10 (IP-10) in LPS-activated macrophages. Taken together, MD-2 is a molecular target in the anti-inflammatory action of 1D10G.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

S-layer glycoprotein from Lactobacillus kefiri CIDCA 8348 enhances macrophages response to LPS in a Ca+2-dependent manner

Highlights: • S-layer protein of L. kefiri CIDCA 8348 (SLP8348) is recognized by ConA. • Uptake of SLP8348 by murine macrophages is inhibited by glucose, mannose and EGTA. • SLP8348 significantly increased LPS-induced response of macrophages. • SLP8348-LPS synergism is abrogated by EGTA, indicating a role of Ca{sup +2} in the effect. • Results suggest the potentiality of SLP8348 for development of new adjuvants. The S-layer is a (glyco)-proteinaceous envelope constituted by self-assembled subunits that form a two-dimensional lattice covering the surface of different species of Bacteria and Archaea. It could be considered as one of the most abundant biopolymers in our planet. Because of their unique self-assembly features, exhibiting repetitive identical physicochemical properties down to the subnanometer scale, as well as their involvement in specific interactions with host cells, the S-layer proteins (SLPs) show a high potential application in different areas of biotechnology, including the development of antigen carriers or new adjuvants. The presence of a glycosylated SLP on potentially probiotic Lactobacillus kefiri strains was previously described by our research group. In this study, we aim to investigate the role of carbohydrates present in the SLP from L. kefiri CIDCA 8348 (SLP-8348) in their internalization by murine macrophages, as well as to analyze their immunomodulatory capacity and their effect on LPS-stimulated macrophages. RAW 264.7 cells internalized the SLP-8348 in a process that was mediated by carbohydrate-receptor interactions since it was inhibited by glucose, mannose or EGTA, a Ca{sup +2} chelating agent. These results correlated with the recognition of SLP-8348 by ConA lectin. We further show that while SLP-8348 was not able to induce the activation of macrophages by itself, it favored the LPS-induced response, since there was a significant increase in the expression of surface cell markers MHC-II, CD86 and CD40, as well as in IL-6 and IL-10 expression at both transcript and protein levels, in comparison with LPS-stimulated cells. The presence of EGTA completely abrogated this synergistic effect. Taken together, these results strongly suggest the involvement of both glycosidic residues and Ca{sup +2} ions in the recognition of SLP-8348 by cellular receptors on murine macrophages. Moreover, these results suggest the potentiality of the SLP-8348 for the development of new adjuvants capable of stimulating antigen presenting cells by interaction with glycan receptors.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2024

Overexpression of the Mas1 gene mitigated LPS-induced inflammatory injury in mammary epithelial cells by inhibiting the NF-κB/MAPKs signaling pathways

Breast infection is the primary etiology of mastitis in dairy cows, leading to a reduction in the quality of dairy products and resulting in substantial economic losses for animal husbandry. Although antibiotic treatment can eliminate the pathogenic microorganisms that induce mastitis, it cannot repair the inflammatory damage of mammary epithelial cells and blood milk barrier. Mas1 is a G protein-coupled receptor, and its role in lipopolysaccharide (LPS) -induced inflammatory injury to mammary epithelial cells has not been studied. LPS treatment of EpH4 EV cells led to a significant downregulation of Mas1 transcript levels, which attracted our great interest, suggesting that Mas1 may be an important target for the treatment of mastitis. Therefore, this study intends to verify the role of Mas1 in the inflammatory injury of EpH4 EV cells by gene overexpression technology and gene silencing technology. The findings demonstrated that the overexpression of the Mas1 gene effectively reversed the activation of the nuclear factor-κB/mitogen-activated protein kinase (NF-κB/MAPK) signaling pathways induced by LPS, while also suppressing the upregulation of pro-inflammatory mediators. Furthermore, overexpression of the Mas1 gene reversed the downregulation of zonula occludens 1 (ZO-1), Occludin, and Claudin-3 caused by LPS, suggesting that Mas1 could promote to repair the blood-milk barrier. However, the silencing of the Mas1 gene using siRNA resulted in a contrasting effect. These results indicated that Mas1 alleviated the inflammatory injury of mammary epithelial cells induced by LPS.

Yan, Shuping↗
DOE OSTI2023

Antibiotic Treatment Prior to Injury Abrogates the Detrimental Effects of LPS in STR/ort Mice Susceptible to Osteoarthritis Development

Post traumatic osteoarthritis (PTOA) is a form of secondary osteoarthritis (OA) that develops in ~50% of cases of severe articular joint injuries and leads to chronic and progressive degradation of articular cartilage and other joint tissues. PTOA progression can be exacerbated by repeated injury and systemic inflammation. Few studies have examined approaches for blunting or slowing down PTOA progression with emphasis on systemic inflammation; most arthritis studies focused on the immune system have been in the context of rheumatoid arthritis. To examine how the gut microbiome affects systemic inflammation during PTOA development, we used a chronic antibiotic treatment regimen starting at weaning for 6 weeks before anterior cruciate ligament (ACL) rupture in STR/ort mice combined with lipopolysaccharide (LPS)-induced systemic inflammation. STR/ort mice develop spontaneous OA as well as a more severe PTOA phenotype than C57Bl/6J mice. By 6 weeks post injury, histological examination showed a more robust cartilage staining in the antibiotic-treated (AB) STR/ort mice than in the untreated STR/ort controls. Furthermore, we also examined the effects of AB treatment on systemic inflammation and found that the effects of LPS administration before injury are also blunted by AB treatment in STR/ort mice. The AB- or AB+LPS-treated STR/ort injured joints more closely resembled the C57Bl/6J VEH OA phenotypes than the vehicle- or LPS-treated STR/ort, suggesting that antibiotic treatment has the potential to slow disease progression and should be further explored therapeutically as prophylactic post injury.

60 APPLIED LIFE SCIENCES↗