Proinflammatory Response In Mice Research Articles

Effect of Epstein-Barr Virus DNA on the Incidence and Severity of Arthritis in a Rheumatoid Arthritis Mouse Model.

ObjectiveWe recently demonstrated that EBV DNA is correlated with proinflammatory responses in mice and in rheumatoid arthritis (RA) patients; hence, we utilized an RA mouse model to examine whether EBV DNA enhances the risk and severity of arthritis and to assess its immunomodulatory effects.MethodsC57BL/6J mice were treated with collagen (arthritis-inducing agent), EBV DNA 6 days before collagen, EBV DNA 15 days after collagen, Staphylococcus epidermidis DNA 6 days before collagen, EBV DNA alone, or water. Mice were then monitored for clinical signs and affected joints/footpads were histologically analysed. The relative concentration of IgG anti- chicken collagen antibodies and serum cytokine levels of IL-17A and IFNϒ were determined by ELISA. The number of cells co-expressing IL-17A and IFNϒ in joint histological sections was determined by immunofluorescence.ResultsThe incidence of arthritis was significantly higher in mice that received EBV DNA prior to collagen compared to mice that only received collagen. Similarly, increased clinical scores, histological scores and paw thicknesses with a decreased gripping strength were observed in groups treated with EBV DNA and collagen. The relative concentration of IgG anti-chicken collagen antibodies was significantly increased in the group that received EBV DNA 6 days prior to collagen in comparison to the collagen receiving group. On the other hand, the highest number of cells co-expressing IFNϒ and IL-17A was observed in joints from mice that received both collagen and EBV DNA.ConclusionEBV DNA increases the incidence and severity of arthritis in a RA mouse model. Targeting mediators triggered by viral DNA may hence be a potential therapeutic avenue.

Aqueous Mulberry Leaf Extract Ameliorates Alcoholic Liver Injury Associating with Upregulation of Ethanol Metabolism and Suppression of Hepatic Lipogenesis

Excessive alcohol intake is a major cause of chronic liver damage and is highly associated with the development of a spectrum of hepatic disorders, including steatohepatitis, liver cirrhosis, and liver cancer. Thus, we aimed to explore the hepatoprotective effects of an aqueous mulberry leaf extract (AME) on alcoholic fatty liver disorder (AFLD) by using a mouse model fed with excessive ethanol. Compared with the normal diet, the ethanol diet significantly increased the body weight of the mice, while the AME supplement reduced the weight gain caused by the ethanol diet. The ethanol diet also attenuated the activity of alcohol dehydrogenase and antioxidant enzymes but increased lipid peroxidation in the liver, which were reversed by AME supplementation. Additionally, AME supplementation diminished the ethanol diet-induced hepatic leukocyte infiltration and expressions of IL-6 and TNFα. Moreover, AME supplementation also reduced the ethanol-diet-induced lipid accumulation and expression of 1-acylglycerol-3-phosphate acyltransferase, acetyl-CoA carboxylase, low-density lipoprotein receptor, and sterol regulatory element-binding protein-1/2 in the liver. Collectively, AME supplementation improved liver lipid accumulation and proinflammatory response in mice induced by the ethanol diet, which was associated with the upregulation of ethanol-metabolizing enzymes and the downregulation of lipogenesis components.

Orosomucoid can predict baseline peritoneal transport characteristics in peritoneal dialysis patients and reduce peritoneal proteins loss

Peritoneal dialysis (PD) is a replacement therapy for end-stage renal disease patients. In the first 4–8 weeks of PD, the patients were given an empirical dialysis prescription due to unknown peritoneal transport characteristics. Proteomic analysis could be used to identify serum biomarkers. In a discovery set, patients were divided into three groups according to the peritoneal equilibration test (PET) results: high (H), high average (HA), low average and low (LA&L) groups. A total of 1051 identified proteins were screened by Nano HPLC-MS/MS. The top two proteins among different peritoneal transport characteristics were Orosomucoid 2 (ORM2) and C-reactive protein (CRP). In a validation set, CRP was significantly elevated in H group than LA&L group, consistent with proteomic analysis. Serum ORM2 was enhanced in LA&L group compared with H and HA group. The expression of ORM2 in peritoneum was also enriched in LA&L group. At last, supplying exogenous ORM could reduce peritoneal proteins loss, without causing a pro-inflammatory response in mice. ORM2 and CRP could be used as biomarkers to predict the baseline peritoneal transport characteristics, and guide the early PD treatment. ORM may serve as a novel therapeutic target for decreasing peritoneal proteins loss in PD patients. SignificancePeritoneal dialysis (PD) is associated with the functional alterations of the peritoneum. PD patients were often given an empirical dialysis prescription due to the unknown peritoneal transport characteristics in the first 4–8 weeks since PD started. Therefore, it is urgently needed to find biomarkers to predict the baseline peritoneal transport characteristics. In this study, we employed a proteomic analysis to identify serum biomarkers in a training set and verified the screened biomarkers in a validation set. We also found that Orosomucoid (ORM) has the potential to decrease peritoneal proteins loss in PD therapy.

Exosomes derived from mycobacterium tuberculosis-infected MSCs induce a pro-inflammatory response of macrophages.

Tuberculosis (TB) is a common infectious disease caused by Mycobacterium tuberculosis (M.tb), and macrophages serve as the primary natural host of M.tb. Mesenchymal stem cells (MSCs)-derived exosomes play an essential role in inflammatory responses. This study aimed to determine the role of exosomes derived from M.tb-infected MSCs (Exo-MSCs-M.tb) on macrophages in vitro and in vivo and the underlying mechanisms. Here, we demonstrated that M.tb infection promoted the production of Exo-MSCs-M.tb, but did not influence MSCs proliferation. Exo-MSCs-M.tb were taken up by macrophages and then induced the pro-inflammatory response of macrophages through elevating the production of TNF-α, RANTES, and iNOS. Also, pro-inflammatory response induced by Exo-MSCs-M.tb displayed a time-dependent pattern in macrophages, in which the highest level of inflammatory response was observed at 72 hours post-infection of MSCs. In addition, the effect of Exo-MSCs-M.tb was mediated through TLR2/4 and MyD88 signaling pathways. Furthermore, Exo-MSCs-M.tb could induce the pro-inflammatory response in mice in vivo, and exosomes isolated from Exo-MSCs-M.tb-treated mice could also promote the pro-inflammatory response. Taken together, these results indicate that Exo-MSCs-M.tb induced the pro-inflammatory response of macrophages through TLRs signaling. This study provides new insight into the potential of MSCs-derived exosomes for the treatment of TB.

A Lipid Peroxidation Product, 4-Hydroxy-2-Nonenal, Triggers Intravascular Coagulation and Inflammation through Generation of Tissue Factor-Positive Microvesicles

Tissue factor (TF) is a cellular receptor for the clotting protease factor VIIa (FVIIa), and TF-FVIIa complex initiates activation of the coagulation cascade. TF-FVIIa also influences non-hemostatic functions via direct or indirect cell signaling. Constitutive expression of TF is primarily restricted to the surface of perivascular cells, sequestered from circulating blood clotting factors, to prevent aberrant intravascular clotting. It has been suggested that TF is also present in the blood associated with microvesicles (MVs). These circulating TF, however, do not induce any thrombotic complications as they are either cleared from the system before they could accumulate to a pathological level or lack procoagulant activity. However, various pathological conditions such as sepsis, diabetes, bacterial infection, atherosclerosis, and cancer can increase the levels of circulating TF+ MVs, which can then trigger intravascular coagulation and inflammation. We hypothesized that oxidative stress, a pathological condition, central to most of the diseases mentioned above, plays a role in the generation of TF+ MVs in vivo, which could contribute to intravascular coagulation and inflammation. We recently showed that 4-hydroxy-2-nonenal (HNE), the most abundant and stable unsaturated aldehyde produced by the oxidation of ω-6 polyunsaturated fatty acids, enhances TF activity in monocytic cells and macrophages. However, the role of HNE in activation of intravascular coagulation is unknown. To investigate this, C57Bl/6J wild-type mice were administered with HNE intraperitoneally (10 mg/kg body weight) and generation of TF+ MVs, activation of intravascular coagulation, and inflammation was assessed. HNE administration markedly increased TF activity associated with MVs. Nanoparticle tracking analysis (NTA) showed a 3-fold increase in the number of MVs in the plasma of HNE-treated mice. Measurement of thrombin-antithrombin (TAT) complexes revealed a significant increase in TAT levels in HNE treated mice. Pre-treatment of the mice with anti-murine TF antibody attenuated the HNE-induced increase in TAT levels. Measurement of plasma clotting times showed a significant reduction in HNE treated mice (118.3 ± 10.42 sec) compared to saline treated control mice (> 300 sec). Incubation of plasma with anti-TF antibody reversed the reduction observed in the plasma clotting time of HNE treated mice. Assessment of clotting in the saphenous vein injury bleeding model showed an increased number of clots, and reduced blood loss in HNE-administered mice compared to saline treated mice. Blockade of TF with 1H1 anti-TF antibody negated the HNE-mediated reduction in the clotting time. Next, we investigated whether HNE administration also induces a proinflammatory response in mice. Blood cells analysis showed approximately a 4-fold increase in circulating neutrophils in HNE-treated mice at 6 h following HNE treatment. Immunohistochemistry studies showed a robust infiltration of neutrophils into the lungs. Cytokine analysis of plasma showed a significant increase in IL-6 and CXCL1 levels in HNE-treated mice. Blockade of TF using 1H1 anti-TF antibody significantly reduced the HNE-mediated neutrophil infiltration into the lungs and completely abrogated the increase in plasma IL-6 levels. In additional studies, we attempted to identify the source of TF+ MVs. It is unlikely that they are originated from monocytes or endothelial cells as HNE did not induce TF expression in these cell types. LPS, used as a positive control, showed significant induction of TF on both PBMCs and the endothelium Immunohistochemistry revealed that HNE disrupted endothelial barrier integrity of vessel wall, raising a possibility that TF+ MVs could have come from perivascular cells. In summary, our data indicate that oxidative stress could induce the release of TF+ MVs, and this would contribute to intravascular coagulation and inflammation. Our studies also suggest that TF-positive microvesicles can be a useful therapeutic target in the treatment of thromboinflammatory diseases. Disclosures No relevant conflicts of interest to declare.

Dietary Linoleic Acid and Its Oxidized Metabolites Exacerbate Liver Injury Caused by Ethanol via Induction of Hepatic Proinflammatory Response in Mice

Alcoholic liver disease is a major human health problem leading to significant morbidity and mortality in the United States and worldwide. Dietary fat plays an important role in alcoholic liver disease pathogenesis. Herein, we tested the hypothesis that a combination of ethanol and a diet rich in linoleic acid (LA) leads to the increased production of oxidized LA metabolites (OXLAMs), specifically 9- and 13-hydroxyoctadecadienoic acids (HODEs), which contribute to a hepatic proinflammatory response exacerbating liver injury. Mice were fed unsaturated (with a high LA content) or saturated fat diets (USF and SF, respectively) with or without ethanol for 10 days, followed by a single binge of ethanol. Compared to SF+ethanol, mice fed USF+ethanol had elevated plasma alanine transaminase levels, enhanced hepatic steatosis, oxidative stress, and inflammation. Plasma and liver levels of 9- and 13-HODEs were increased in response to USF+ethanol feeding. We demonstrated that primarily 9-HODE, but not 13-HODE, induced the expression of several proinflammatory cytokines invitro in RAW264.7 macrophages. Finally, deficiency of arachidonate 15-lipoxygenase, a major enzyme involved in LA oxidation and OXLAM production, attenuated liver injury and inflammation caused by USF+ethanol feeding but had no effect on hepatic steatosis. This study demonstrates that OXLAM-mediated induction of a proinflammatory response in macrophages is one of the potential mechanisms underlying the progression from alcohol-induced steatosis to alcoholic steatohepatitis.

Vardenafil reduces macrophage pro-inflammatory overresponses in cystic fibrosis through PDE5- and CFTR-dependent mechanisms.

Chronic inflammation that progressively disrupts the lung tissue is a hallmark of cystic fibrosis (CF). In mice, vardenafil, an inhibitor of phosphodiesterase type5 (PDE5), restores transepithelial ion transport and corrects mislocalization of the most common CF mutation, F508del-CFTR. It also reduces lung pro-inflammatory responses in mice and in patients with CF. To test the hypothesis that macrophages are target effector cells of the immunomo-dulatory effect of vardenafil, we isolated lung macrophages from mice homozygous for the F508del mutation or invalidated for the cftr gene and from their corresponding wild-type (WT) littermates. We then evaluated the effect of vardenafil on the classical M1 polarization, mirroring release of pro-inflammatory cytokines. We confirmed that macrophages from different body compartments express CF transmembrane conductance regulator (CFTR) and showed that vardenafil targets the cells through PDE5- and CFTR-dependent mechanisms. In the presence of the F508del mutation, vardenafil down-regulated overresponses of the M1 markers, tumour necrosis factor (TNF)-α and inducible nitric oxide synthase (NOS)-2. Our study identifies lung macrophages as target cells of the anti-inflammatory effect of vardenafil in CF and supports the view that the drug is potentially beneficial for treating CF as it combines rescue of CFTR protein and anti-inflammatory properties.

Carbon Nanotubes: Carbon Nanotubes Disrupt Iron Homeostasis and Induce Anemia of Inflammation through Inflammatory Pathway as a Secondary Effect Distant to Their Portal‐of‐Entry (Small 15/2017)

In article number 1603830, by Sijin Liu and co-workers, the exposure of multi-wall carbon nanotubes (MWCNTs) alters hepatic hepcidin-mediated systemic iron homeostasis through pro-inflammatory responses in mice, leading to limited iron availability for red blood cell formation, and eventually the development of anemia of inflammation. This study opens a new path to understanding the biological impacts of carbon nanotubes through their secondary or compensatory effects beyond the primary target tissues and organs.

In Vivo Synthesis of Cyclic-di-GMP Using a Recombinant Adenovirus Preferentially Improves Adaptive Immune Responses against Extracellular Antigens.

There is a compelling need for more effective vaccine adjuvants to augment induction of Ag-specific adaptive immune responses. Recent reports suggested the bacterial second messenger bis-(3'-5')-cyclic-dimeric-guanosine monophosphate (c-di-GMP) acts as an innate immune system modulator. We recently incorporated a Vibrio cholerae diguanylate cyclase into an adenovirus vaccine, fostering production of c-di-GMP as well as proinflammatory responses in mice. In this study, we recombined a more potent diguanylate cyclase gene, VCA0848, into a nonreplicating adenovirus serotype 5 (AdVCA0848) that produces elevated amounts of c-di-GMP when expressed in mammalian cells in vivo. This novel platform further improved induction of type I IFN-β and activation of innate and adaptive immune cells early after administration into mice as compared with control vectors. Coadministration of the extracellular protein OVA and the AdVCA0848 adjuvant significantly improved OVA-specific T cell responses as detected by IFN-γ and IL-2 ELISPOT, while also improving OVA-specific humoral B cell adaptive responses. In addition, we found that coadministration of AdVCA0848 with another adenovirus serotype 5 vector expressing the HIV-1-derived Gag Ag or the Clostridium difficile-derived toxin B resulted in significant inhibitory effects on the induction of Gag and toxin B-specific adaptive immune responses. As a proof of principle, these data confirm that in vivo synthesis of c-di-GMP stimulates strong innate immune responses that correlate with enhanced adaptive immune responses to concomitantly administered extracellular Ag, which can be used as an adjuvant to heighten effective immune responses for protein-based vaccine platforms against microbial infections and cancers.

Glycoprotein isolated from Styrax japonica Siebold et al. Zuccarini inhibits oxidative and pro-inflammatory responses in HCT116 colonic epithelial cells and dextran sulfate sodium-treated ICR mice

This study was carried out to investigate the anti-inflammatory potentials of a 38 kDa glycoprotein isolated from Styrax japonica Siebold et al Zuccarini (SJSZ glycoprotein). We found that SJSZ glycoprotein has concentration-dependent scavenging activity against DPPH and hydroxyl radicals in the cell-free systems. In colonic epithelial cells (HCT116 cells), the results showed that SJSZ glycoprotein inhibits the production of reactive oxygen species (ROS) induced by glucose/glucose oxidase (G/GO) in a concentration-dependent manner. Experimental mouse colitis was induced by adding dextran sulfate sodium (DSS) to the drinking water at a concentration of 4% (w/v) for 7 days. We figured out that administration of SJSZ glycoprotein (10 mg/kg) lowers the levels of disease activity index, myeloperoxidase activity, and histological inflammation in DSS-treated mice. In addition, SJSZ glycoprotein inhibited plasmic thiobarbituric acid reactive substances (TBARS) formation, nitric oxide (NO) production, and lactate dehydrogenase (LDH) release, accompanying the inhibition of colonic inflammatory signal proteins (NF-κB, iNOS, and COX-2) and inflammation-related cytokines (IL-1β, IL-6, and TNF-α). These results indicate that SJSZ glycoprotein inhibits oxidative and pro-inflammatory responses in mouse colitis.

Alterations in Interleukin-1β and Interleukin-6 in Mice Inoculated Through the Oral Routes Using Graded Doses of <i>p. Multocida</i> Type b: 2 and its Lipopolysaccharide

The gram-negative bacterium Pasteurella multocida serotype B: 2 is an important veterinary and opportunistic human pathogen that causes deplorable welfare problems and colossal economic production losses in bovine and other animal species throughout the world. Pasteurella multocida type B: 2 and its LPS are associated with Haemorrhagic Septicaemia (HS) in mice as animal model. Sixty healthy Balb c mice were placed in twelve plastic cages each one containing five mice. The mice were divided into three major groups (A, B and C). Group A is the control group (n = 10) and these were inoculated with 0.4 mL of PBS pH 7.4 orally. The treatment groups (B; n = 25 and C; n = 25) were inoculated with P. multocida type B: 2 and lipopolysaccharide respectively. The mice in group B and C were further divided into five subgroups. The subgroups were designated based on the graded doses as B101, B103, B105, B107 and B109 for Pasteurella multocida and C101, C103, C105, C107 and C109 for LPS respectively. The mice were observed for 120 h post-inoculation. The concentration of IL-1β was significantly higher (p<0.001) in the B107 of P. multocida type B: 2 and C109 of LPS compared to the control group and the other treatment groups. The concentration of IL-6 was significantly higher (p<0.001) in the B103 cfu of P. multocida type B: 2 and C109 cfu of LPS compared to the control group and the other treatment groups. Interleukin-1β and interleukin-6 evaluated in this study were predominantly associated with HS in varying doses of 101, 103, 105, 107 and 109 in the whole cell and its LPS respectively. Therefore, the target of this study was to investigate on pro-inflammatory response in mice infected with graded doses of Pasteurella multocida serotype B: 2 and its LPS via the oral route of inoculation.

In vitro and in vivo effects of some inhibitors of signal cascades on cytokines and signal proteins production in raw 264.7 macrophage cells and in mouse lymphocytes

In vitro and in vivo effects of some inhibitors of the activity of signal cascades NF-κB and SAPK/JNK, and the TLR4 receptor on the immune cells activity were studied. To evaluate in vitro effects, the macrophage-like RAW 264.7 cells were cultured with each of the inhibitors, namely IKK inhibitor XII, SP600125, CLI-095, and OxPAPK (the first two are the inhibitors of NF-κB, SAPK/JNK cascades, and the last two compounds are the inhibitors of the TLR4 receptor activity). On the whole, all of the used inhibitors did not induce pro-inflammatory response in RAW 264.7 cells. On the contrary, the inhibitor of SAPK/JNK cascade, and, especially, the inhibitor of NF-κB cascade significantly decreased production of the TNF-α, IL-1, IL-6, IFN-γ, and IL-10 in RAW 264.7 cells. In these cells, the inhibitors substantially decreased “back-ground stress response” of macrophages, differently reducing a production of heat shock proteins, HSP72 and HSP90-α, and diminishing phosphorylation of signal proteins from NF-κB and SAPK/JNK cascades. Results of in vitro experiments suggest that the inhibitor of NF-κB activity was the most effective. It was this inhibitor that was intraperitonealy injected in Balb/C male mice in the in vivo experiments in order to study its effect on the activity of immune cells. Results showed that IKK Inhibitor XII applied in vivo did not induce pro-inflammatory response in mice, but decreased the activity of NF-κB cascade, and lowered HSP90-α expression in mouse splenic lymphocytes. So, among the studied compounds, IKK Inhibitor XII seems to be a very effective inhibitor that may be used to decrease cytokine and stress response in various pathologies.

The intestinal environment of surgical injury transforms Pseudomonas aeruginosa into a discrete hypervirulent morphotype capable of causing lethal peritonitis

Secondary peritonitis continues to carry a high mortality rate despite the aggressive use of imaging, drainage, and antibiotics. Although host factors and microbial burden contribute to the outcome of peritonitis, we propose a role for bacterial virulence as a determinant of outcome from peritonitis. Bacterial virulence is an inducible trait that is activated in response to specific local "cues" that we have previously shown to be present in the mouse gut exposed to surgical stress and injury. Pseudomonas aeruginosa was harvested after its intestinal inoculation into the cecum of mice subjected to surgical injury (30% hepatectomy) or sham surgery (controls). Harvested strains were then injected into the peritoneum of noninjured (naïve) mice and mortality determined. P. aeruginosa harvested from the intestines of surgically injured mice caused 100% mortality, whereas strains harvested from control mice caused no mortality. Among recovered strains, a distinct P.aeruginosa morphotype (wrinkled shape) was shown to cause lethal peritonitis compared to smooth-shaped strains, which were nonlethal. Wrinkled strains were associated with a tendency to elicit a more proinflammatory response in mice compared to smooth-shaped strains. Surgical injury transforms the morphotype of intestinal P. aeruginosa to express a hypervirulent response in the peritoneum of mice. Enhanced virulence of intestinal pathogens in response to surgical injury may play an important role in predicting the outcome of peritonitis.

Resuscitation with washed aged packed red blood cell units decreases the proinflammatory response in mice after hemorrhage

Resuscitation with blood products instead of crystalloid in the treatment of hemorrhagic shock has been associated with improved outcomes in trauma patients requiring massive transfusions and transfusion of fresh products results in reduced morbidity and mortality compared with aged blood. Processes to eliminate harmful components of aged blood are under investigation. We hypothesized that washing blood would reduce levels of proinflammatory mediators in stored units, and resuscitation with washed units would attenuate the proinflammatory response in mice after hemorrhagic shock. Mice underwent pressure-controlled hemorrhage and resuscitation with fresh packed red blood cells (pRBCs) or 15-day-old washed or unwashed pRBCs. Cytokine concentrations in donor samples and recipient serum were measured. In addition, cytokine concentrations were measured in 15-day-old units that underwent three interval washes versus one poststorage wash. Blood stored for 15 days demonstrated increased levels of interleukin 1α, keratinocyte chemoattractant, macrophage inflammatory protein 1α, and macrophage inflammatory protein 2 compared with fresh units. Washing 15-day-old pRBCs reduced concentrations of these cytokines. Cytokine levels in stored units that underwent multiple washes versus a single wash were not different. Mice resuscitated with 15-day-old unwashed pRBCs had increased levels of serum cytokines compared with mice resuscitated with fresh and 15-day-old washed pRBCs. Aged pRBC units have elevated levels of proinflammatory cytokines compared with fresh units, and washing aged units after storage reduces cytokine concentrations. Resuscitation with washed units blunts the proinflammatory response in mice after hemorrhage. Washing aged pRBCs may improve the safety profile of aged units and may result in improved outcomes in subjects after hemorrhagic shock and resuscitation.

Housefly Maggots (Musca domestica) Protein-enriched Fraction/ extracts (PE) Inhibit Lipopolysaccharide-induced Atherosclerosis Pro-inflammatory Responses

To investigate the effects of housefly maggot (Musca domestica) protein-enriched fraction/extracts (PE) on lipopolysaccharide (LPS)-induced atherosclerosis (AS) pro-inflammatory responses in mice and macrophages. The mouse model of AS was established by feeding a cholesterol-enriched diet and inducing by LPS. Changes in the levels of blood lipids (total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL) and high-density lipoprotein cholesterol (HDL)) and pro-inflammatory cytokines (interferon-gamma (IFNγ), tumor necrosis factor alpha (TNFα) and interleukin-1alpha (IL-1α)) were determined. Histomorphometric analysis of the pathological condition of the artery was also carried out. The macrophages were stimulated by LPS in the presence or absence of PE, and then the levels of TNFα, IL-1α and monocyte chemotactic protein 1 (MCP-1) in cell culture supernatant were measured. Compared with the negative control group, the levels of three pro-inflammatory cytokines were significantly enhanced in the PE treatment group (p< 0.01). The concentrations of TC, TG and LDL were lower in the PE treatment group than in the negative control group (p< 0.01). HDL concentration in the PE treatment group was higher than in the negative control group (p< 0.01). Histomorphometric analysis showed that the thickness of the intima and media area, as well as the area ratio of the intima to media in the PE treatment group were lower than in the negative control group (p< 0.01). The expression of TNFα, IL-1α and MCP-1 in LPS-induced macrophages was inhibited by different concentrations of PE (p< 0.01). These results indicate that PE potently inhibited multiple pro-inflammatory responses in experimental atherosclerosis lesions in vivo, and possessed anti-pro-inflammatory properties in vitro.

Chronic Systemic Infection Exacerbates Ischemic Brain Damage via a CCL5 (Regulated on Activation, Normal T-Cell Expressed and Secreted)-Mediated Proinflammatory Response in Mice

Infection and systemic inflammation are risk factors for cerebrovascular diseases and poststroke infections impair outcome in stroke patients, although the mechanisms of their contribution are mostly unknown. No preclinical studies have identified how chronic infection affects ischemic brain damage and which key inflammatory mediators are involved. We used a well established model of gut infection (Trichuris muris) to study how chronic infection contributes to brain injury. We show that, in mice, infection that leads to a chronic Th1-polarized immune response dramatically (60%) exacerbates brain damage caused by experimental stroke. Chronic Th1-type infection resulted in systemic upregulation of proinflammatory mediators and profoundly altered stroke-induced early (40 min to 4 h) and late (48 h) inflammation in the brain and peripheral tissues. Using the same infection, we show that a Th1-, but not Th2-polarized response augments brain injury by increasing the Th1 chemokine CCL5 [regulated on activation, normal T-cell expressed and secreted (RANTES)] systemically. This infection-associated response paralleled altered regulatory T-cell response, accelerated platelet aggregation in brain capillaries, and increased microvascular injury and matrix metalloproteinase activation after stroke. Antibody neutralization of RANTES reversed the effect of chronic infection on brain damage, microvascular MMP-9 activation, and cellular inflammatory response. Our results suggest that chronic infection exacerbates ischemic brain damage via a RANTES-mediated systemic inflammatory response, which leads to delayed resolution of inflammation and augmented microvascular injury in the brain.

Toll-like receptor-mediated cytokine production is differentially regulated by glycogen synthase kinase 3.

The cellular mechanisms that directly regulate the inflammatory response after Toll-like receptor (TLR) stimulation are unresolved at present. Here we report that glycogen synthase kinase 3 (GSK3) differentially regulates TLR-mediated production of pro- and anti-inflammatory cytokines. Stimulation of monocytes or peripheral blood mononuclear cells with TLR2, TLR4, TLR5 or TLR9 agonists induced substantial increases in interleukin 10 production while suppressing the release of proinflammatory cytokines after GSK3 inhibition. GSK3 regulated the inflammatory response by differentially affecting the nuclear amounts of transcription factors NF-kappaB subunit p65 and CREB interacting with the coactivator CBP. Administration of a GSK3 inhibitor potently suppressed the proinflammatory response in mice receiving lipopolysaccharide and mediated protection from endotoxin shock. These findings demonstrate a regulatory function for GSK3 in modulating the inflammatory response.