Pretreatment of Low-Dose and Super-Low-Dose LPS on the Production of In Vitro LPS-Induced Inflammatory Mediators

Accumulated LPS induced by colitis altered the activities of vitamin D-metabolizing hydroxylases and decreased the generation of 25-hydroxyvitamin D

It is generally accepted that low vitamin D (VD) levels are associated with a high prevalence factor for Inflammatory bowel disease (IBD). IBD patients have observed higher levels of lipopolysaccharide (LPS), ALT, and AST than healthy people. Gut-derived LPS causes inflammatory injury in the liver and kidney. The VD-metabolizing mechanism is involved in the liver and kidney, which means IBD might impact VD metabolism. However, whether IBD affects VD metabolism has not been studied. In vitro LPS resulted in decreased CYP2R1 in liver cells as well as decreased CYP27B1 and increased CYP24A1 in kidney cells, revealing that LPS changed the activities of several hydroxylases. Mice with acute colitis had an increased LPS in serum and liver with mild hepatic injuries, while mice with chronic colitis had a significant elevation of LPS in serum, liver, and kidney with hepatorenal injuries. Thus, the liver hydroxylase for VD metabolism would be the first to be affected in IBD. Consequently, serum 25-hydroxyvitamin D declined dramatically with a significant elevation of 24,25-dihydroxyvitamin D and 1,24,25-trihydroxyvitamin D. Unchanged serum levels of 1,25-dihydroxyvitamin D might be the result of other factors in vivo. In acute colitis, a small dosage (4 IU/day) of cholecalciferol could protect the colon, decrease the serum level of LPS, and finally increase serum 25-hydroxyvitamin D. However, this improvement of cholecalciferol was fading in chronic colitis. These results suggested that VD supplementations for preventing and curing IBD in the clinic should consider hepatorenal hydroxylases and be employed as soon as possible for a better outcome.

Endoplasmic reticulum stress is attenuated by glycolysis in lymphatic malformations

BACKGROUND

This study aims to investigate the role of endoplasmic reticulum stress (ER stress) in human dermal lymphatic endothelial cells (HDLECs) and lymphatic malformations (LMs) and its relationship with aerobic glycolysis and inflammation.

METHODS

The proliferation and apoptosis of HDLECs were examined with lipopolysaccharide (LPS) treatment. ER stress-associated proteins and glycolysis-related markers were detected by western blot. Glycolysis indexes were detected by seahorse analysis and lactic acid production assay kits. Immunohistochemistry was used to reveal the ER stress state of lymphatic endothelial cells (LECs) in LMs.

RESULTS

LPS induced ER stress in HDLECs but did not trigger detectable apoptosis. Intriguingly, LPS-treated HDLECs also showed increased glycolysis flux. Knockdown of Hexokinase 2, a key enzyme for aerobic glycolysis, significantly inhibited the ability of HDLECs to resist ER stress-induced apoptosis. Moreover, compared to normal skin, glucose-regulated protein 78 (GRP78/BIP), and phosphorylation protein kinase R-like kinase (p-PERK), two key ER stress-associated markers, were upregulated in LECs of LMs, which was correlated with the inflected state. In addition, excessively activated ER stress inhibited the progression of LMs in rat models.

CONCLUSIONS

These data indicate that glycolysis could rescue activated ER stress in HDLECs, which is required for the accelerated development of LMs.

IMPACT

Inflammation enhances both ER stress and glycolysis in LECs while glycolysis is required to attenuate the pro-apoptotic effect of ER stress. Endoplasmic reticulum (ER) stress is activated in lymphatic endothelial cells (LECs) of LMs, especially in inflammatory condition. The expression of ER stress-related proteins is increased in LMs and correlated with Hexokinase 2 expression. Pharmacological activation of ER stress suppresses the formation of LM lesions in the rat model. ER stress may be a promising and effective therapeutic target for the treatment of LMs.

Treatment with bestatin (the exogenous synthetic inhibitor of metalloproteinases) reduces the activity of metalloproteinase 2 and 12 in the spleen and lung tissues of rats in a model of lipopolysaccharide-induced sepsis

Sepsis is caused by an inadequate or dysregulated host response to infection. Enzymes causing cellular degradation are matrix metalloproteinases (MMPs). Lipopolysaccharide (LPS) is used in models of sepsis in laboratory settings The aim of the study was to measure MMP 2 and 12 concentrations in spleen and lungs in rats in which septic shock was induced by LPS. The experiment was carried out on 40 male Wistar rats (5 groups of 8): 0. controls 1. administered LPS 2. administered bestatin 3. LPS and bestatin 4.bestatin and after 6 hours LPS Animals were decapitated. Lungs and spleens were collected. Concentrations of MMP-2 and MMP-12 were determined using immunoenzymatic methods. Mean (±SD) MMP-2 in the controls was 43.57 ± 20.53 ng/ml in the lungs and 1.7 ± 0.72 ng/ml in the spleen; Group 1: 31.28 ± 13.13 ng/ml, 0.83 ± 0.8 ng/ml; Group 2: 44.24 ± 22.75 ng /ml, 1.01 ± 0.32 ng/ml; Group 3: 35.94 ± 15.13 ng/ml, 0.41 ± 0.03 ng/ml; Group 4:79.42 ± 44.70 ng/ml, 0.45 ± 0.15, respectively. Mean MMP-12 in controls was 19.79 ± 10.01 ng/ml in lungs and 41.13 ± 15.99 ng/ml in the spleen; Group 1:27.97 ± 15.1 ng/ml; 40.44 ± 11.2 ng/ml; Group 2: 37.93 ± 25.38 ng/ml 41.05 ± 18.08 ng/ml; Group 3: 40.59 ± 11.46 ng/ml, 35.16 ± 12.89 ng/ml; Group 4: 39.4 ± 17.83 ng/ml, 42.04 ± 12.35 ng/ml, respectively. CONCLUSIONS: 1. Bestatin reduces MMP 2 and 12 levels in spleen and lungs. 2. Treatment with bestatin minimizes the effect of LPS.

LncRNA PVT1 promotes neuroinflammation after intracerebral hemorrhage by regulating the miR-128-3p/TXNIP axis

OBJECTIVE

Intracerebral hemorrhage (ICH) has significant morbidity and mortality. TXNIP and the competing endogenous RNA (ceRNA) regulatory mechanism involved in long non-coding RNA (lncRNA) play roles in ICH. We probed the upstream microRNAs (miRNAs)/lncRNAs that regulated TXNIP expression in the ceRNA mechanism.

METHODS

ICH mouse model was established, and ICH secondary injury was simulated in BV2 microglia by hemin treatment. TXNIP was silenced 48 h before ICH modeling. The ICH mouse brain water content (BWC) and brain lesion volume after ICH were recorded. Neuronal apoptosis and neurological deficits were evaluated by double staining of NeuN and TUNEL/modified Garcia/corner turn/forelimb placement tests. Iba1 + microglia number and tumor necrosis factor-α (TNF-α)/interleukin-1β (IL-1β)/IL-10/TXNIP/PVT1/miR-128-3p levels were assessed by immunohistochemistry, Western blot, ELISA, and RT-qPCR. Cell viability/death of BV2 cells conditioned medium-treated neuron HT22 cells were assessed by CCK-8/LDH assays. miRNA that had a targeted binding relationship with TXNIP was screened. The targeted bindings of miR-128-3p to TXNIP/PVT1 to miR-128-3p were verified by dual-luciferase reporter gene assay.

RESULTS

TXNIP knockdown reduced post-ICH microglial activation/release of pro-inflammatory factors/brain edema/brain lesion volume/neurological deficits in mice and increased releases of anti-inflammatory factors. TXNIP/PVT1 knockdown inhibited hemin-induced inflammatory responses in BV2 cells and protected in vitro co-cultured HT22 cells. PVT1 was a sponge of miR-128-3p to repress TXNIP expression. miR-128-3p knockdown diminished PVT1 knockdown-inhibited hemin-induced BV2 cell inflammatory responses/neurotoxicity.

CONCLUSIONS

PVT1 silencing reduced hemin-induced neuroinflammation and had a protective effect on neurons by increasing the targeted inhibition of TXNIP by miR-128-3p.

TNFα is a key trigger of inflammation in diet-induced non-obese MASLD in mice

Tumor necrosis factor alpha (TNFα) is thought to be a critical factor in the development of metabolic dysfunction-associated steatotic liver disease (MASLD). Here, we determined the effects of a treatment with the anti-TNFα antibody infliximab and a genetic deletion of TNFα, respectively, in the development of non-obese diet-induced early metabolic dysfunction-associated steatohepatitis (MASH) in mice. The treatment with infliximab improved markers of liver damage in mice with pre-existing early MASH. In TNFα-/- mice, the development of early signs of MASH and insulin resistance was significantly attenuated compared to wild-type animals. While mRNA expression of proinflammatory cytokines like interleukin 1β (Il1b) and interleukin 6 (Il6) were significantly lower in livers of MASH-diet-fed TNFα-/- mice compared to wild-type mice with early MASH, markers of intestinal barrier function were similarly impaired in both MASH-diet-fed groups compared to controls. Our data suggest that TNFα is a key regulator of hepatic inflammation and insulin resistance associated with the development of early non-obese MASH.

Prolonged Inhibition of the MEK1/2-ERK Signaling Axis Primes Interleukin-1 Beta Expression through Histone 3 Lysine 9 Demethylation in Murine Macrophages

Macrophages undergo different cellular states upon activation that can be hyporesponsive (tolerated) or hyperresponsive (primed or trained) to subsequent stimuli. Epigenetic modifications are known to play key roles in determining these cellular states. However, little is known about the role of signaling pathways that lead to these epigenetic modifications. Here, we examined the effects of various inhibitors targeting key signaling pathways induced by lipopolysaccharide (LPS) on tolerance and priming in murine macrophages. We found that a prolonged inhibition (>18 h) of the mitogen-activated protein kinase (MEK)1/2-extracellular signal-regulated kinase (ERK)1/2 signaling axis reversed tolerance and primed cells in expressing interleukin (IL)-1β and other inflammatory cytokines such as IL-6, tumor necrosis factor (TNF)α, and CXCL10. The ectopic expression of catalytically active and inactive MEK1 mutants suppressed and enhanced IL-1β expression, respectively. A transcriptomic analysis showed that cells primed by the MEK1/2 inhibitor U0126 expressed higher levels of gene sets associated with immune responses and cytokine/chemokine production, but expressed lower levels of genes with cell cycle progression, chromosome organization, and heterochromatin formation than non-primed cells. Of interest, the mRNA expressions of the histone 3 lysine 9 (H3K9) methyltransferase Suv39h1 and the H3K9 methylation reader Cbx5 were substantially suppressed, whereas the H3K9 demethylase Kdm7a was enhanced, suggesting a role of the MEK1/2-ERK signaling axis in H3K9 demethylation. The H3K9 trimethylation levels in the genomic regions of IL-1β, TNFα, and CXCL10 were decreased by U0126. Also, the H3K9 methyltransferase inhibitor BIX01294 mimicked the U0126 training effects and the overexpression of chromobox homolog (CBX)5 prevented the U0126 training effects in both RAW264.7 cells and bone-marrow-derived macrophages. Collectively, these data suggest that the prolonged inhibition of the MEK1/2-ERK signaling axis reverses tolerance and primed macrophages likely through decreasing the H3K9 methylation levels.

Effect of multifactorial therapeutic approach on axonal regeneration and cell viability in an in-vitro model of spinal-derived neural injury

The highly debilitated nature of spinal cord injuries (SCI) creates an inhibitory repair environment that limits the recovery rate and therefore single interventional treatment has been resulted in incomplete recovery. A multifactorial approach that combines several therapeutic approaches may address diverse aspects of SCI pathology and enhance the recovery rate over single therapy. Accordingly, in this study, we aimed to investigate the effect of combined olfactory ensheathing cells (OECs) (to transport trophic factor, mediate immunomodulation, provide a suitable environment for cell survival), G-CSF (to establish a favorable environment for cell survival) and lipopolysaccharide (LPS) (to boost the protective activity of OEC) therapy on the cell viability after a scratch injury caused by a cataract knife on cells in an in-vitro model of spinal-derived neural injury. In this study, we used mixed neuronal-glial cultures, which are widely used for an in vitro study of neuronal damage. Scratch insult was made on cells using a cataract knife. The cells were divided into 8 groups (two control groups with and without olfactory ensheathing cells (OECs) treatment, injury group, three injury groups with single therapy by using super low dose of LPS (SLD-LPS) (100 pg/ml), OEC group, and G-CSF (100 ng/ml) group, and two injury groups with combined therapy (OEC with SLD-LPS and with all three treatments)). We found a significant decrease in the survival rate of injured cells (p < 0.001) 24 h after scratching insult. Our results indicated morphological alterations in cells in the acute phase (1, 2 and 6 h) after injury, with significant increased gap size at 6 h after induction of injury. Our combined therapy, significantly prevented cell death and decreased the size of the gap over time. We found that combined therapy promoted cell survival following spinal injury by providing a neuroprotective environment for cells. Therefore, our findings provide new insight into the combined therapy, which can be considered for promising preclinical therapeutic strategy for SCI toward clinical trials.

The β1 Adrenergic Blocker Nebivolol Ameliorates Development of Endotoxic Acute Lung Injury

Acute lung injury (ALI) is a disease, with no effective treatment, which might result in death. Formations of excessive inflammation and oxidative stress are responsible for the pathophysiology of ALI. Nebivolol (NBL), a third-generation selective β1 adrenoceptor antagonist, has protective pharmacological properties, such as anti-inflammatory, anti-apoptotic, and antioxidant functions. Consequently, we sought to assess the efficacy of NBL on a lipopolysaccharide (LPS)-induced ALI model via intercellular adhesion molecule-1 (ICAM-1) expression and the tissue inhibitor of metalloproteinases-1 (TIMP-1)/matrix metalloproteinases-2 (MMP-2) signaling. Thirty-two rats were split into four categories: control, LPS (5 mg/kg, intraperitoneally [IP], single dose), LPS (5 mg/kg, IP, one dosage 30 min after last NBL treatment), + NBL (10 mg/kg oral gavage for three days), and NBL (10 mg/kg oral gavage for three days). Six hours after the administration of LPS, the lung tissues of the rats were removed for histopathological, biochemical, gene expression, and immunohistochemical analyses. Oxidative stress markers such as total oxidant status and oxidative stress index levels, leukocyte transendothelial migration markers such as MMP-2, TIMP-1, and ICAM-1 expressions in the case of inflammation, and caspase-3 as an apoptotic marker, significantly increased in the LPS group. NBL therapy reversed all these changes. The results of this study suggest that NBL has utility as a potential therapeutic agent to dampen inflammation in other lung and tissue injury models.

Low-Dose Lipopolysaccharide Protects from Lethal Paramyxovirus Infection in a Macrophage- and TLR4-Dependent Process

Respiratory diseases are a major public health burden and a leading cause of death and disability in the world. Understanding antiviral immune responses is crucial to alleviate morbidity and mortality associated with these respiratory viral infections. Previous data from human and animal studies suggested that pre-existing atopy may provide some protection against severe disease from a respiratory viral infection. However, the mechanism(s) of protection is not understood. Low-dose LPS has been shown to drive an atopic phenotype in mice. In addition, LPS has been shown in vitro to have an antiviral effect. We examined the effect of LPS treatment on mortality to the murine parainfluenza virus Sendai virus. Low-dose LPS treatment 24 h before inoculation with a normally lethal dose of Sendai virus greatly reduced death. This protection was associated with a reduced viral titer and reduced inflammatory cytokine production in the airways. The administration of LPS was associated with a marked increase in lung neutrophils and macrophages. Depletion of neutrophils failed to reverse the protective effect of LPS; however, depletion of macrophages reversed the protective effect of LPS. Further, we demonstrate that the protective effect of LPS depends on type I IFN and TLR4-MyD88 signaling. Together, these studies demonstrate pretreatment with low-dose LPS provides a survival advantage against a severe respiratory viral infection through a macrophage-, TLR4-, and MyD88-dependent pathway.

Pretreated Mesenchymal Stem Cells and Their Secretome: Enhanced Immunotherapeutic Strategies

Mesenchymal stem cells (MSCs) with self-renewing, multilineage differentiation and immunomodulatory properties, have been extensively studied in the field of regenerative medicine and proved to have significant therapeutic potential in many different pathological conditions. The role of MSCs mainly depends on their paracrine components, namely secretome. However, the components of MSC-derived secretome are not constant and are affected by the stimulation MSCs are exposed to. Therefore, the content and composition of secretome can be regulated by the pretreatment of MSCs. We summarize the effects of different pretreatments on MSCs and their secretome, focusing on their immunomodulatory properties, in order to provide new insights for the therapeutic application of MSCs and their secretome in inflammatory immune diseases.

Magnolia kobus Extract Inhibits Periodontitis-Inducing Mediators in Porphyromonas gingivalis Lipopolysaccharide-Activated RAW 264.7 Cells

Periodontitis, a disease caused by inflammation of oral bacteria, contributes to the loss of alveolar bone and destruction of connective tissues. Porphyromonas gingivalis, a Gram-negative bacterium, is known to possess important pathogenic factors for periodontal disease. In this study, we investigated the anti-periodontitis effects of Magnolia kobus extract (MKE) and magnolin as a component of Magnolia kobus (MK) in murine macrophage RAW 264.7 cells stimulated with Porphyromonas gingivalis lipopolysaccharide (LPS). Effects of MKE and magnolin on the mechanism of RAW 264.7 cellular inflammation were determined by analyzing nitric oxide (NO) production and Western blot protein expression (n = 3). MKE/magnolin inhibited NO production without affecting cell survival. MKE/magnolin treatment inhibited LPS-induced pro-inflammatory cytokines, expression levels of matrix metalloproteinases (MMPs such as MMP-1, 3, 8, 9, and 13), and protein levels of inflammatory mediators (such as TNF-α, IL-1β, and mPGES-1). MKE/magnolin also suppressed NF-κB activation by inhibiting the TLR4 signaling pathway. These findings suggest that MKE has a therapeutic effect on inflammatory periodontal disease caused by oral bacterium P. gingivalis and that magnolin is a major functional component in the anti-inflammatory effect of MKE.

Regulation of the MyD88 gene in chicken spleen inflammation induced by stress

In order to investigate the regulatory role of the myeloid differentiation factor 88 (MyD88) gene in the stress inflammatory response to chicken spleen, the chicken stress model and macrophage (HD11) inflammation model were constructed in this study. Enzyme-linked immunosorbent assay and quantitative real-time PCR were used to investigate the effects of MyD88 on immune and inflammatory indicators. The results demonstrated that the levels of IgG, CD3+ and CD4+ in the serum of chickens in the beak trimming stress and heat stress groups decreased significantly compared to the control group without stress (P < 0.05), and the inflammation-related indices IL-1β, TNF-α, IL-6 and NF-κB increased significantly (P < 0.05). Stress up-regulated the expression levels of MyD88, IL-1β, NF-κB and TLR4 in the spleen, stimulated the release of inflammatory factors. Overexpression of MyD88 significantly up-regulated the expression levels of the inflammatory factors IL-1β, TNF-α, IL-8, NF-κB and TLR4 in HD11 cells (P < 0.05). Co-treatment with lipopolysaccharide (LPS) further promoted the expression levels of the inflammatory cytokines in HD11 cells. Interference with the expression of MyD88 significantly reduced the expression level of inflammatory factors in HD11 cells (P < 0.05) and had an antagonistic effect with LPS to alleviate the inflammatory reaction. In conclusion, the MyD88 gene has a pro-inflammatory effect and is highly expressed in the beak trimming and heat stress models in chicks, regulating the inflammatory response in poultry. It was involved in regulating the expression of immune-related genes in HD11 cells and had a synergistic effect with LPS.

Liver vs. spleen: Time course of organ-dependent immune gene expression in an LPS-stimulated toad (Rhinella diptycha)

The inflammatory response comprises highly orchestrated events that are conserved amongst vertebrate groups. Hepatic and splenic cytokines are major mediators of the systemic inflammatory processes. However, the liver is still neglected as an immune organ in amphibians. This study reports organ-dependent gene expression using an anuran model. We tracked mRNA levels of immune proteins [C1s (subcomponent S of the complement protein 1), IFN-γ, IL-1β, IL-6, and IL-10] at four time-points (1 h, 3 h, 6 h, and 18 h post-injection) in spleens and livers of intraperitoneal LPS-challenged (2 mg/kg) adult male toads (Rhinella diptycha) using independent samples. We found acute C1s up-regulation in the liver 1 h post-injection, with no treatment effect in the spleen. The LPS injection did not show any effect in splenic IFN-γ gene expression while eliciting only a marginal effect in the hepatic tissue. IL-1β was up-regulated in both organs, with the liver initially displaying early expression (1 h and 3 h) and the spleen taking over late expression (18 h). Both organs exhibited similar patterns for IL-6, with early up-regulation (1 h and 3 h) and late peak (18 h). Although IL-10 was early detected and up-regulated only in the liver, both organs showed up-regulation in 6 h and 18 h post-injection. Our results show an exclusive hepatic prominence in complement protein expression during the acute-phase response. Furthermore, hepatic pro-inflammatory cytokine expression was more pronounced in earliest time-points, while the spleen offers a slower and more consistent response overall. Our data provide an organ-integrative outlook into the initial hours of the inflammation in amphibians, confirming the liver's pivotal role as a regulator in the acute-phase of the inflammatory response in amphibians.

Involvement of Anti-Inflammatory and Stress Oxidative Markers in the Antidepressant-like Activity of Aloysia citriodora and Verbascoside on Mice with Bacterial Lipopolysaccharide- (LPS-) Induced Depression

Aloysia citriodora Palau is popularly used to treat nervous disorders. Experimental evidence has indicated that verbascoside (VBS) isolated from A. citriodora has pharmacological potential. In this study, we evaluated the antidepressant-like effects of a hydroalcoholic extract of A. citriodora (HEAc) and VBS against lipopolysaccharide- (LPS-) induced depressive-like behavior in mice. In the pretreatment protocol (performed to evaluate the preventive potential), mice were pretreated with HEAc (3, 30, or 300 mg/kg) or VBS (30 mg/kg) before the administration of LPS. In the posttreatment protocol (performed to evaluate the therapeutic potential), mice were initially administered LPS and were subsequently given HEAc (3, 30, or 300 mg/kg) or VBS (30 mg/kg). In both treatments, the mice were submitted to an open-field test and tail suspension test (TST) at 6 and 24 h after LPS administration. The posttreatment evaluation revealed that HEAc (30 or 300 mg/kg) and VBS produced an antidepressant-like effect, as indicated by a reduction in the time spent with no movement in the TST. Moreover, HEAc (30 or 300 mg/kg) was found to reduce interleukin-6 (IL-6) levels and N-acetyl-glycosaminidase activity in the hippocampus, increase glutathione (GSH) levels in the hippocampus and cortex, and enhance IL-10 in the cortex and, at a dose of 300 mg/kg, reduced myeloperoxidase activity in the cortex. Contrastingly, no comparable effects were detected in mice subjected to the pretreatment protocol. Administration of VBS similarly reduced the levels of IL-6 in the hippocampus and increased GSH levels in the cortex. Our observations indicate that both HEAc and VBS show promising antidepressant-like potential, which could be attributed to their beneficial effects in reducing neuroinflammatory processes and antioxidant effects in the central nervous system.

Phloretin Protects Bovine Rumen Epithelial Cells from LPS-Induced Injury

Lipopolysaccharide (LPS) is an endotoxin that induces immune and inflammatory responses in the rumen epithelium of dairy cows. It is well-known that flavonoid phloretin (PT) exhibits anti-oxidative, anti-inflammatory and antibacterial activity. The aim of this research was to explore whether PT could decrease LPS-induced damage to bovine rumen epithelial cells (BRECs) and its molecular mechanisms of potential protective efficacy. BRECs were pretreated with PT for 2 h and then stimulated with LPS for the assessment of various response indicators. The results showed that 100 µM PT had no significant effect on the viability of 10 µg/mL LPS-induced BRECs, and this dose was used in follow-up studies. The results showed that PT pre-relieved the decline in LPS-induced antioxidant indicators (T-AOC and GSH-PX). PT pretreatment resulted in decreased interleukin-1β (IL-1β), IL-6, IL-8, tumor necrosis factor-α (TNF-α) and chemokines (CCL2, CCL5, CCL20) expression. The underlying mechanisms explored reveal that PT may contribute to inflammatory responses by regulating Toll-like receptor 4 (TLR4), nuclear transcription factor-κB p65 (NF-κB p65), and ERK1/2 (p42/44) signaling pathways. Moreover, further studies found that LPS-induced BRECs showed decreased expression of claudin-related genes (ZO-1, Occludin); these were attenuated by pretreatment with PT. These results suggest that PT enhances the antioxidant properties of BRECs during inflammation, reduces gene expression of pro-inflammatory cytokines and chemokines, and enhances barrier function. Overall, the results suggest that PT (at least in vitro) offers some protective effect against LPS-induced ruminal epithelial inflammation. Further in vivo studies should be conducted to identify strategies for the prevention and amelioration of short acute rumen acidosis (SARA) in dairy cows using PT.

microRNA-196b alleviates lipopolysaccharide-induced inflammatory injury by targeting NRAS

Bovine endometritis is a serious hazard to husbandry, so it is necessary to know the mechanism of endometritis. In past research, we found microRNAs (miRNAs) might be regulators in inflammation, including miR-196b, but the mechanism of miR-196b in bovine endometritis was unknown. Therefore, we tended to find out what role miR-196b would play in bovine endometritis. As a result, we found miR-196b up-regulated in the endometritis tissue and the high concentration lipopolysaccharide (LPS)-stimulated bovine endometrial epithelial (BEND) cell line, but down-regulated in the low concentration. And, over-expression of miR-196b inhibited the expressions of some inflammatory factors, such as tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and neuroblastoma RAS (NRAS)/nuclear factor (NF)-κB pathway proteins. Furthermore, the dual-luciferase reporter assay and NRAS knockdown confirmed that miR-196b inhibited activation of the downstream pathway by directly targeting NRAS. In conclusion, we provide evidence that miR-196b alleviates LPS-induced inflammatory injury by targeting NRAS.

Pinocembrin ameliorates acute liver failure via activating the Sirt1/PPARα pathway in vitro and in vivo

Acute liver failure (ALF) is a life-threatening disease and affects multiple organ systems. Pro-inflammatory factors derived from macrophage plays a key role in septicemia. Pinocembrin is a natural favonoid compound, which can be extracted from honey, propolis and several other plants. Recent investigations demonstrate that Pinocembrin has a variety of pharmacological activities, including anti-inflammatory and antioxidant. To investigate the effects of Pinocembrin on ALF, we explored its possible molecular mechanisms through the experiments in vivo and in vitro. Pre-treatment with Pinocembrin attenuated LPS-induced hepatocyte dysfunction and reduced levels of pro-inflammatory factors and macrophages infiltration. Pinocembrin inhibited the hepatocyte apoptosis and pro-inflammatory reaction of peritoneal macrophages by reducing reactive oxygen species (ROS) via the Sirt1/PPARα signaling pathway. Our study suggests that Pinocembrin might represent a novel therapeutic drug and offers a new method for the treatment of ALF.

2,4,6-Trihydroxy-3-geranyl acetophenone suppresses vascular leakage and leukocyte infiltration in lipopolysaccharide-induced endotoxemic mice

CONTEXT

Lipopolysaccharide (LPS) exacerbates systemic inflammatory responses and causes excessive fluid leakage. 2,4,6-Trihydroxy-3-geranyl acetophenone (tHGA) has been revealed to protect against LPS-induced vascular inflammation and endothelial hyperpermeability in vitro.

OBJECTIVE

This study assesses the in vivo protective effects of tHGA against LPS-induced systemic inflammation and vascular permeability in endotoxemic mice.

MATERIALS AND METHODS

BALB/c mice were intraperitoneally pre-treated with tHGA for 1 h, followed by 6 h of LPS induction. Evans blue permeability assay and leukocyte transmigration assay were performed in mice (n = 6) pre-treated with 2, 20 and 100 mg/kg tHGA. The effects of tHGA (20, 40 and 80 mg/kg) on LPS-induced serum TNF-α secretion, lung dysfunction and lethality were assessed using ELISA (n = 6), histopathological analysis (n = 6) and survivability assay (n = 10), respectively. Saline and dexamethasone were used as the negative control and drug control, respectively.

RESULTS

tHGA significantly inhibited vascular permeability at 2, 20 and 100 mg/kg with percentage of inhibition of 48%, 85% and 86%, respectively, in comparison to the LPS control group (IC₅₀=3.964 mg/kg). Leukocyte infiltration was suppressed at 20 and 100 mg/kg doses with percentage of inhibition of 73% and 81%, respectively (IC₅₀=17.56 mg/kg). However, all tHGA doses (20, 40 and 80 mg/kg) failed to prevent endotoxemic mice from lethality because tHGA could not suppress TNF-α overproduction and organ dysfunction.

DISCUSSION AND CONCLUSIONS

tHGA may be developed as a potential therapeutic agent for diseases related to uncontrolled vascular leakage by combining with other anti-inflammatory agents.

Lactobacillus reuteri Alleviates Gastrointestinal Toxicity of Rituximab by Regulating the Proinflammatory T Cells in vivo

Rituximab (RTX) is a widely used anticancer drug with gastrointestinal side effects, such as nausea, vomiting, and diarrhea. The reason for these side effects is still poorly understood. Previous studies have reported that the intestinal microbiota is associated with the occurrence of disease and the therapeutic effect of drugs. In this study, we observed mucosal damage, inflammatory cell infiltration and increased intestinal inflammatory factor expression in RTX-treated mice. RTX also changed the diversity of the intestinal microbiota in mice, and decreased abundance of Lactobacillus reuteri was observed in RTX-treated mice. Further experiments revealed that intragastric administration of L. reuteri in RTX-treated mice attenuated the intestinal inflammatory response induced by RTX and regulated the proportion of helper T (Th) cells. In conclusion, our data characterize the effect of the intestinal microbiota on RTX-induced intestinal inflammation, suggesting that modifying the gut microbiota may represent a positive strategy for managing adverse reactions.

The Effect of Ferula communis Extract in Escherichia coli Lipopolysaccharide-Induced Neuroinflammation in Cultured Neurons and Oligodendrocytes

In recent decades, interest in natural compounds has increased exponentially due to their numerous beneficial properties in the treatment of various acute and chronic diseases. A group of plant derivatives with great scientific interest is terpenic compounds. Among the plants richest in terpenes, the genus Ferula L. is one of the most representative, and ferutinin, the most common sesquiterpene, is extracted from the leaves, rhizome, and roots of this plant. As reported in the scientific literature, ferutinin possesses antioxidant and anti-inflammatory properties, as well as valuable estrogenic properties. Neurodegenerative and demyelinating diseases are devastating conditions for which a definite cure has not yet been established. The mechanisms involved in these diseases are still poorly understood, and oxidative stress is considered to be both a key modulator and a common denominator. In the proposed experimental system, co-cultured human neurons (SH-SY5Y) and human oligodendrocytes (MO3.13) were treated with the pro-inflammatory agent lipopolysaccharide at a concentration of 1 μg/mL for 24 h or pretreated with ferutinin (33 nM) for 24 h and subsequently exposed to lipopolysaccharide 1 μg/mL for 24 h. Further studies would, however, be needed to establish whether this natural compound can be used as a support strategy in pathologies characterized by progressive inflammation and oxidative stress phenomena.

Near infrared light activation of an injectable whole-cell cancer vaccine for cancer immunoprophylaxis and immunotherapy

Cancer vaccines play a key role in the prevention and treatment of early and recurrent tumors. Although they have been widely studied during the past few decades, designing an efficient and economical cancer vaccine is still challenging. Here, we propose an injectable live cell cancer vaccine (InLCCV) using live tumor cells as immunogenic sources for cancer immunoprophylaxis and immunotherapy. InLCCV is fabricated by loading live mouse breast cancer cells (4T1 cells), gold nanorods (GNRs), and super-low-dose lipopolysaccharide (LPS) into a biocompatible Pluronic F127 in situ hydrogel matrix. After in situ inactivation by the photothermal effect of GNRs upon near-infrared (NIR) laser irradiation, immunogenic cell death (ICD) of 4T1 cells is induced and tumor-associated antigens (TAAs) together with loaded LPS are released subsequently. Therefore, dendritic cells and macrophages are activated accordingly, further stimulating the systemic anti-tumor immune response. After vaccinating with InLCCV, the tumor-free percentage of the mice is 60% and the survival rate during the observation period reaches up to 80%. For lung metastasis, the metastatic foci are 3.9-fold less than those of the control group. The as-developed InLCCV shows much promise as a potential platform for breast cancer immunoprophylaxis and immunotherapy.

[Fractalkine inhibits lipopolysaccharide-induced M1 polarization of macrophages by activating Wnt/β-catenin signaling pathway]

OBJECTIVE

To explore the mechanism by which fractalkine (CX3CL1; FKN) inhibits lipopolysaccharide (LPS)-induced immunological response in RAW264.7 cells.

METHODS

A RAW264.7 cell model overexpressing FKN was established by transfection with the lentiviral vector CX3CL1. The effects of LPS, ICG-001 (a Wnt/β-catenin signaling pathway inhibitor), either alone or in combination, on M1 polarization of na?ve and FKN-overexpressing RAW264.7 cells were evaluated by detecting of intereukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) using ELISA. The protein expressions of the inflammatory factors (iNOS, TNF-α, and IL-6), FKN, Wnt-4, and β-catenin were detected by Western blotting. The subcellular localization of IL-6 in the cells was detected by immunofluorescence assay.

RESULTS

The RAW264.7 cell model of FKN overexpression was successfully established. In na?ve RAW264.7 cells, treatment with both ICG-001 and LPS, as compared with LPS alone, significant promoted TNF-α and IL-6 secretions, increased intracellular levels of TNF-α, IL-6 and iNOS (P < 0.05), and reduced intracellular FKN, Wnt-4 and β-catenin levels (P < 0.01). In FKN-overexpressing RAW264.7 cells, LPS treatment significantly reduced the secretion of TNF-α and IL-6 and intracellular levels of TNF-α, IL-6 and iNOS (P < 0.01), increased intracellular FKN, Wnt-4 and β-catenin protein contents (P < 0.01), and inhibited IL-6 localization in the cytoplasm; compared with LPS, the combined treatment with ICG-001 and LPS obviously enhanced IL-6 localization in the cytoplasm of the cells.

CONCLUSIONS

FKN overexpression suppresses LPS-induced M1 type polarization of RAW264.7 cells by activating Wnt/β-catenin signaling pathway.

Galangin Inhibits LPS-Induced MMP-9 Expression via Suppressing Protein Kinase-Dependent AP-1 and FoxO1 Activation in Rat Brain Astrocytes

Purpose

Neuroinflammation, characterized by the increased expression of inflammatory proteins such as matrix metalloproteinases (MMPs), plays a critical role in neurodegenerative disorders. Lipopolysaccharide (LPS) has been shown to upregulate MMP-9 expression through the activation of various transcription factors, including activator protein 1 (AP-1) and forkhead box protein O1 (FoxO1). The flavonoid 3,5,7-trihydroxy-2-phenyl-4H-1-benzopyran-4-one (galangin) has been demonstrated to possess antioxidant and anti-inflammatory properties in various types of cells. Here, we investigated the mechanisms underlying the inhibitory effect of galangin on LPS-induced MMP-9 expression in rat brain astrocytes (RBA-1 cells).

Methods

Pharmacological inhibitors and siRNAs were employed to explore the effects of galangin on LPS-challenged RBA-1 cells. Gelatin zymography, Western blotting, real-time PCR, and a luciferase reporter assay were used to detect MMP-9 activity, protein expression, mRNA levels, and promoter activity, respectively. The protein kinases involved in the LPS-induced MMP-9 expression were determined by Western blot. A chromatin immunoprecipitation (ChIP) assay was employed to evaluate the activity of c-Jun at the MMP-9 promoter.

Results

Galangin treatment attenuated the LPS-mediated induction of MMP-9 protein and mRNA expression, as well as the activity at the MMP-9 promoter. In addition, galangin exerted its inhibitory effects on MMP-9 expression through suppressing the LPS-stimulated activation of proline-rich tyrosine kinase (Pyk2), platelet-derived growth factor receptor beta (PDGFRβ), phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), mammalian target of rapamycin (mTOR), and mitogen-activated protein kinases (MAPKs). Pretreatment with galangin attenuated the LPS-induced phosphorylation of c-Jun and FoxO1. LPS-induced cell migration was also suppressed by galangin pretreatment.

Conclusion

Galangin attenuates the LPS-induced inflammatory responses, including the induction of MMP-9 expression and cell migration, via inhibiting Pyk2/PDGFRβ/PI3K/Akt/mTOR/JNK1/JNK2 and p44/p42 MAPK cascade-dependent AP-1 and FoxO1 activities. These results provide new insights into the mechanisms through which galangin mitigates LPS-induced inflammatory responses, and suggest novel strategies for the management of LPS-related brain diseases.

Antidepressant-like effects of solidagenone on mice with bacterial lipopolysaccharide (LPS)-induced depression

BACKGROUND

Considering the pharmacological potential of solidagenone from Solidago chilensis, the present investigation was carried out to evaluate its antidepressant-like effect in mice with bacterial lipopolysaccharide (LPS)-induced depressive like behavior and its mode of action through the measurement of neuroinflammatory and oxidative markers.

MATERIALS AND METHODS

In the prophylactic test, the mice were pretreated with solidagenone (1, 10 or 100 mg/kg, p.o) and after one hour received LPS. In therapeutic test, the mice received LPS and after 5 h were treated with solidagenone (1, 10 or 100 mg/kg, p.o). In both experimental approaches, the animals were submitted to OFT and to the TST after 6 and 24 h of the LPS administration, respectively. One hour after the TST the animals were euthanized, the blood was collected, the cortex was removed and biochemical analyzes were performed for measurement of the inflammatory and oxidative stress markers.

RESULTS

The LPS induced sickness- and depressive-like behaviors and increased the cortical activity of myeloperoxidase (MPO), as well as the IL-6 and TNF amount. Interestingly, the pretreatment with solidagenone at 100 mg/kg avoided the behavioral alterations in OFT. In the mice post treated with solidagenone, all tested doses of resulted in an antidepressant-like effect evidenced by the decrease in immobility time in the TST. This effect was accompanied by a decrease in the MPO activity and in the IL-6 and TNF levels in the cortex in parallel to the increase in catalase activity.

CONCLUSIONS

The solidagenone has a promissor antidepressant-like potential, which can result of its beneficial action in the neuroinflammation process and due its antioxidant capability at the central nervous system.

Mismatch between circulating cytokines and spontaneous cytokine production by leukocytes in hyperinflammatory COVID-19

The disease COVID‐19 has developed into a worldwide pandemic. Hyperinflammation and high levels of several cytokines, for example, IL‐6, are observed in severe COVID‐19 cases. However, little is known about the cellular origin of these cytokines. Here, we investigated whether circulating leukocytes from patients with COVID‐19 had spontaneous cytokine production. Patients with hyperinflammatory COVID‐19 (n = 6) and sepsis (n = 3) were included at Skåne University Hospital, Sweden. Healthy controls were also recruited (n = 5). Cytokines were measured in COVID‐19 and sepsis patients using an Immulite immunoassay system. PBMCs were cultured with brefeldin A to allow cytokine accumulation. In parallel, LPS was used as an activator. Cells were analyzed for cytokines and surface markers by flow cytometry. High levels of IL‐6 and measurable levels of IL‐8 and TNF, but not IL‐1β, were observed in COVID‐19 patients. Monocytes from COVID‐19 patients had spontaneous production of IL‐1β and IL‐8 (P = 0.0043), but not of TNF and IL‐6, compared to controls. No spontaneous cytokine production was seen in lymphocytes from either patients or controls. Activation with LPS resulted in massive cytokine production by monocytes from COVID‐19 patients and healthy controls, but not from sepsis patients. Finally, monocytes from COVID‐19 patients produced more IL‐1β than from healthy controls (P = 0.0087) when activated. In conclusion, monocytes contribute partly to the ongoing hyperinflammation by production of IL‐1β and IL‐8. Additionally, they are responsive to further activation. This data supports the notion of IL‐1β blockade in treatment of COVID‐19. However, the source of the high levels of IL‐6 remains to be determined.

Effect of low-dose corticosterone pretreatment on the production of inflammatory mediators in super-low-dose LPS-primed immune cells

Pretreatment of super-low-dose lipopolysaccharide (SL-LPS) induces a more hyperresponsive state on the production of proinflammatory mediators to a subsequent secondary challenge with high-dose LPS in innate immune cells. Low-dose glucocorticoids (GCs) are also known to induce inflammation and immunosuppression in the immune cells. However, there is limited knowledge on whether preconditioning of low-dose GCs enhances inflammatory responses and dysregulates T lymphocyte responses to secondary LPS in SL-LPS-primed immune cells. In the present study, RAW 264.7 and EL4 cells were pretreated with SL-LPS (50 pg/ml) or low-dose corticosterone (CORT50: 50 ng/ml and CORT100: 100 ng/ml) in fresh complete medium once a day for 2-3 days, consecutively, and then cultured in fresh complete medium for 6 or 24 h in the presence or absence of LPS (1-10 μg/ml) or concanavalin A (Con A). The results demonstrated that the repeated pretreatment of CORT50 strongly enhanced production of IL-6, IL-10, TNF-α, and nitric oxide (NO) by RAW 264.7 cells in EP (SL-LPS-primed cells: endotoxin priming) in the absence of LPS compared to those in control (vehicle-pretreated cells), whereas CORT100 reduced production of TNF-α and IL-10. Further, the repeated pretreatment of CORT50 markedly enhanced LPS-induced production of IL-6, IL-10, TNF-α, PGE₂, and NO by RAW 264.7 cells in EP compared to those in control, whereas CORT100 attenuated LPS-induced production of IL-6, IL-10, and NO. Moreover, the repeated pretreatments of CORT50 and CORT100 greatly attenuated the Con A-stimulated production of IFN-γ and IFN-γ/IL-10 and LPS-stimulated production of IL-10, IFN-γ, and IFN-γ/IL-10 by SL-LPS-primed EL4 cells (EP). These findings suggest that double preconditionings of low grade hypercortisolemia and metabolic endotoxemia may act as important risk factors for metabolic disorder and severe morbidity and mortality in septic shock via upregulated production of inflammatory mediators and immunosuppression of IFN-γ-mediated responses.

Transcriptome, Spliceosome and Editome Expression Patterns of the Porcine Endometrium in Response to a Single Subclinical Dose of Salmonella Enteritidis Lipopolysaccharide

Endometrial infections at a young age can lead to fertility issues in adulthood. Bacterial endotoxins, such as lipopolysaccharide (LPS), can participate in long-term molecular changes even at low concentrations. Lipopolysaccharide plays a crucial role in the progression of septic shock, inflammation and auto-immune diseases. The aim of this study was to describe transcriptomic modulations in the porcine endometrium, induced in vivo by a single subclinical dose of LPS from Salmonella Enteritidis. which did not produce clinical symptoms of toxicity. The RNA-seq methodology was applied to reveal 456 differentially expressed regions, including 375 genes, four long noncoding RNAs, and 77 other unclassified transcripts. Two independent methods confirmed 118 alternatively spliced genes that participate i.a., in the formation of the MHC-I complex and the adaptive immune response. Single nucleotide variant-calling algorithms supported the identification of 3730 allele-specific expression variants and 57 canonical A-to-I RNA editing sites. The results demonstrated that the differential expression of genes involved in inflammation, immune response, angiogenesis and endometrial development may be maintained for up to 7 days after exposure to LPS. RNA editing sites and long noncoding RNAs (lncRNAs) play an important role in transcriptional regulatory machinery in the porcine endometrium in response to LPS administration.

Mitochondrial respiratory capacity modulates LPS-induced inflammatory signatures in human blood

Mitochondria modulate inflammatory processes in various model organisms, but it is unclear how much mitochondria regulate immune responses in human blood leukocytes. Here, we examine the effect of i) experimental perturbations of mitochondrial respiratory chain function, and ii) baseline inter-individual variation in leukocyte mitochondrial energy production capacity on stimulated cytokine release and glucocorticoid (GC) sensitivity. In a first cohort, whole blood from 20 healthy women and men was stimulated with increasing concentrations of the immune agonist lipopolysaccharide (LPS). Four inhibitors of mitochondrial respiratory chain Complexes I, III, IV, and V were used (LPS + Mito-Inhibitors) to acutely perturb mitochondrial function, GC sensitivity was quantified using the GC-mimetic dexamethasone (DEX) (LPS + DEX), and the resultant cytokine signatures mapped with a 20-cytokine array. Inhibiting mitochondrial respiration caused large inter-individual differences in LPS-stimulated IL-6 reactivity (Cohen's d = 0.72) and TNF-α (d = 1.55) but only minor alteration in EC50-based LPS sensitivity (d = 0.21). Specifically, inhibiting mitochondrial Complex IV potentiated LPS-induced IL-6 levels by 13%, but inhibited TNF-α induction by 72%, indicating mitochondrial regulation of the IL-6/TNF-α ratio. As expected, DEX treatment suppressed multiple LPS-induced pro-inflammatory cytokines (IFN-γ, IL-6, IL-8, IL-1β, .TNF-α) by >85% and increased the anti-inflammatory cytokine IL-10 by 80%. Inhibiting Complex I potentiated DEX suppression of IL-6 by a further 12% (d = 0.73), indicating partial mitochondrial modulation of glucocorticoid sensitivity. Finally, to examine if intrinsic mitochondrial respiratory capacity may explain a portion of immune reactivity differences across individuals, we measured biochemical respiratory chain enzyme activities and mitochondrial DNA copy number in isolated peripheral blood mononuclear cells (PBMCs) from a second cohort of 44 healthy individuals in parallel with LPS-stimulated IL-6 and TNF-α response. Respiratory chain .function, particularly Complex IV activity, was positively correlated with LPS-stimulated IL-6 levels (r = 0.45, p = 0.002). Overall, these data provide preliminary evidence that mitochondrial behavior modulates LPS-induced inflammatory cytokine signatures in human blood.

Transcription analysis of the response of the porcine adrenal cortex to a single subclinical dose of lipopolysaccharide from Salmonella Enteritidis

Lipopolysaccharide (LPS) is a bacterial endotoxin which can participate in the induction of inflammatory responses. LPS may also play a significant role in some neurodegenerative, oncological and metabolic disorders. The aim of the current study was to determine the effect of a subclinical low single dose of LPS from Salmonella Enteritidis administrated in vivo on the transcriptome of porcine adrenal cortex cells, especially gene expression levels, long non-coding RNA (lncRNA) profiles, alternative splicing events and RNA editing sites using RNA-seq technology. The subclinical dose of LPS changed the expression of 354 genes, 27 lncRNA loci and other unclassified RNAs. An analysis of alternative splicing events revealed 104 genes with differentially expressed splice junction sites, and the single nucleotide variant calling approach supported the identification of 376 canonical RNA editing candidates and 7249 allele-specific expression variants. The obtained results suggest that the RIG-I-like receptor signaling pathway, may play a more important role than the Toll-like signaling pathway after the administration of a subclinical dose of LPS. Single subclinical dose of LPS can affect the expression profiles of genes coding peptide hormones, steroidogenic enzymes and transcriptional factors, and modulate the endocrine functions of the gland.

Frontline Science: Endotoxin-induced immunotolerance is associated with loss of monocyte metabolic plasticity and reduction of oxidative burst

Secondary infections are a major complication of sepsis and associated with a compromised immune state, called sepsis-induced immunoparalysis. Molecular mechanisms causing immunoparalysis remain unclear; however, changes in cellular metabolism of leukocytes have been linked to immunoparalysis. We investigated the relation of metabolic changes to antimicrobial monocyte functions in endotoxin-induced immunotolerance, as a model for sepsis-induced immunoparalysis. In this study, immunotolerance was induced in healthy males by intravenous endotoxin (2 ng/kg, derived from Escherichia coli O:113) administration. Before and after induction of immunotolerance, circulating CD14⁺ monocytes were isolated and assessed for antimicrobial functions, including cytokine production, oxidative burst, and microbial (Candida albicans) killing capacity, as well metabolic responses to ex vivo stimulation. Next, the effects of altered cellular metabolism on monocyte functions were validated in vitro. Ex vivo lipopolysaccharide stimulation induced an extensive rewiring of metabolism in naive monocytes. In contrast, endotoxin-induced immunotolerant monocytes showed no metabolic plasticity, as they were unable to adapt their metabolism or mount cytokine and oxidative responses. Validation experiments showed that modulation of metabolic pathways, affected by immunotolerance, influenced monocyte cytokine production, oxidative burst, and microbial (C. albicans) killing in naive monocytes. Collectively, these data demonstrate that immunotolerant monocytes are characterized by a loss of metabolic plasticity and these metabolic defects impact antimicrobial monocyte immune functions. Further, these findings support that the changed cellular metabolism of immunotolerant monocytes might reveal novel therapeutic targets to reverse sepsis-induced immunoparalysis.

Inhibitory Effects of a Novel Chrysin-Derivative, CPD 6, on Acute and Chronic Skin Inflammation

The skin is an important physiological barrier against external stimuli, such as ultraviolet radiation (UV), xenobiotics, and bacteria. Dermal inflammatory reactions are associated with various skin disorders, including chemical-induced irritation and atopic dermatitis. Modulation of skin inflammatory response is a therapeutic strategy for skin diseases. Here, we synthesized chrysin-derivatives and identified the most potent derivative of Compound 6 (CPD 6). We evaluated its anti-inflammatory effects in vitro cells of macrophages and keratinocytes, and in vivo dermatitis mouse models. In murine macrophages stimulated by lipopolysaccharide (LPS), CPD 6 significantly attenuated the release of inflammatory mediators such as nitric oxide (NO) (IC₅₀ for NO inhibition: 3.613 μM) and other cytokines. In cultured human keratinocytes, CPD 6 significantly attenuated the release of inflammatory cytokines induced by the combination of IFN-γ and TNF-α, UV irradiation, or chemical irritant stimulation. CPD 6 inhibited NFκB and JAK2/STAT1 signaling pathways, and activated Nrf2/HO-1 signaling. In vivo relevancy of anti-inflammatory effects of CPD 6 was observed in acute and chronic skin inflammation models in mice. CPD 6 showed significant anti-inflammatory properties both in vitro cells and in vivo dermatitis animal models, mediated by the inhibition of the NFκB and JAK2-STAT1 pathways and activation of Nrf2/HO-1 signaling. We propose that the novel chrysin-derivative CPD 6 may be a potential therapeutic agent for skin inflammation.

Novel reprogramming of neutrophils modulates inflammation resolution during atherosclerosis

Nonresolving inflammation perpetuated by innate leukocytes is involved in the pathogenesis of unstable atherosclerosis. However, the role and regulation of neutrophils related to nonresolving inflammation and atherosclerosis are poorly understood. We report herein that chronic subclinical endotoxemia, a risk factor for atherosclerosis, skewed neutrophils into a nonresolving inflammatory state with elevated levels of inflammatory mediators (Dectin-1, MMP9, and LTB4) and reduced levels of homeostatic mediators (LRRC32, TGFβ, and FPN). The polarization of neutrophils was due to ROS-mediated activation of oxCAMKII, caused by altered peroxisome homeostasis and reduced lysosome fusion. Application of 4-phenylbutyrate (4-PBA) enhanced peroxisome homeostasis of neutrophils, reduced oxCAMKII, and rebalanced the expression profiles of pro- and anti-inflammatory mediators. Adoptive transfer of neutrophils programmed by subclinical endotoxemia rendered exacerbated atherosclerosis. In contrast, transfer of ex vivo programmed neutrophils by 4-PBA reduced the pathogenesis of atherosclerosis. Our data define novel neutrophil dynamics associated with the progression and regression of atherosclerosis.

Methyl jasmonate a stress phytohormone attenuates LPS induced in vivo and in vitro arthritis

The objective of present study was to screen the effect of methyl jasmonate (MJ) in lipopolysaccharide (LPS) induced in vivo and in vitro arthritis. Arthritis was induced in wistar rats by intraplantar administration of LPS (1 mg/Kg) and effect of MJ was screened in two doses (20, 40 mg/Kg, IP), indomethacin (30 mg/Kg p.o) was used as standard. The anti-nociceptive effect was evaluated through behavioral assessment viz. cold allodynia, Paw thermal hyperalgesia and Tail cold hyperalgesia on 1st, 7th, 14th, 21st and 28th day. The Myeloperoxidase (MPO), Cathepsin D (CAT-D), articular elastase (ELA), and nitrite levels were estimated in articular cartilage tissues on the 28th day. Rat paw was subjected to histopathology after radiological examination on 28th day. In vitro effect of MJ was evaluated for three concentrations (5, 10, 20 µg/ml) in LPS (1 µg/ml) stimulated CHNO001 cells. Estimation of pro-inflammatory mediators was carried using ELISA. Significant reduction in pro-inflammatory mediators was observed in MJ treated chondrocyte cells. % proteinase inhibition was assessed for 10, 50, 100, 250, 500 µg/mL and IC₅₀ was found 266.15. MJ significantly reducesnociceptive response against hot and cold allodynia. Significant reduction in MPO, ELA, and nitrite levels was observed. The CAT-D levels significantly restored. Minimum focal mild infiltration of lymphocytes was observed at synovial area in standard and MJ treated rats. These current studies conclude that MJ has protective role in arthritis.

Gamma-irradiation of Streptococcus pneumoniae for the use as an immunogenic whole cell vaccine

Streptococcus pneumoniae is a major respiratory pathogen that causes millions of deaths worldwide. Although subunit vaccines formulated with the capsular polysaccharides or their protein conjugates are currently-available, low-cost vaccines with wide serotype coverage still remain to be developed, especially for developing countries. Recently, gamma- irradiation has been considered as an effective inactivation method to prepare S. pneumoniae vaccine candidate. In this study, we investigated the immunogenicity and protective immunity of gamma-irradiated S. pneumoniae (r-SP), by comparing with heat-inactivated S. pneumoniae (h-SP) and formalin-inactivated S. pneumoniae (f-SP), both of which were made by traditional inactivation methods. Intranasal immunization of C57BL/6 mice with r-SP in combination with cholera toxin as an adjuvant enhanced S. pneumoniaespecific antibodies on the airway mucosal surface and in sera more potently than that with h-SP or f-SP under the same conditions. In addition, sera from mice immunized with r-SP potently induced opsonophagocytic killing activity more effectively than those of h-SP or f-SP, implying that r-SP could induce protective antibodies. Above all, immunization with r-SP effectively protected mice against S. pneumoniae infection. Collectively, these results suggest that gamma- irradiation is an effective method for the development of a killed whole cell pneumococcal vaccine that elicits robust mucosal and systemic immune responses.