No description available.

No description available.

In recent years, increased focus has been placed on the role of intrauterine infection and inflammation in the pathogenesis of fetal brain injury leading to neurodevelopmental disorders such as cerebral palsy. At present, the mechanisms by which inflammatory processes during pregnancy cause this effect on the fetus are poorly understood. Our previous work has indicated an association between experimentally-induced intrauterine infection, increased proinflammatory cytokines, and increased white matter injury in the guinea pig fetus. In order to further elucidate the pathways by which inflammation in the maternal system or the fetal membranes leads to fetal impairment, a number of studies investigating aspects of the disease process have been performed. These studies represent a body of work encompassing novel research and results in a number of human and animal studies. Using a guinea pig model of inflammation, increased amniotic fluid proinflammatory cytokines and fetal brain injury were found after a maternal inflammatory response was initiated using endotoxin. In order to more closely monitor the fetal response to chorioamnionitis, a model using the chronically catheterized fetal ovine was carried out. This study demonstrated the adverse effects on fetal white matter after intrauterine exposure to bacterial inoculation, though the physiological parameters of the fetus were relatively stable throughout the experimental protocol, even when challenged with intermittent hypoxic episodes. The placenta is an important mediator between mother and fetus during gestation, though its role in the inflammatory process is largely undefined. Studies on the placental role in the inflammatory process were undertaken, and the limited ability of proinflammatory cytokines and endotoxin to cross the placenta are detailed herein. Neurodevelopmental disorders can be monitored in animal models in order to determine effective disease models for characterization of injury and use in therapeutic strategies. Our characterizations of postnatal behaviour in the guinea pig model using motility monitoring and spatial memory testing have shown small but significant differences in pups exposed to inflammatory processes in utero. The data presented herein contributes a breadth of knowledge to the ongoing elucidation of the pathways by which fetal brain injury occurs. Determining the pathway of damage will lead to discovery of diagnostic criteria, while determining the vulnerabilities of the developing fetus is essential in formulating therapeutic options. / Thesis (Ph.D, Anatomy & Cell Biology) -- Queen's University, 2008-03-06 20:24:03.417

Cytokines are important mediators of immune functions in humans and animals, interleukin (IL)-15 is a proinflammatory cytokine, which is mainly produced by monocytes. It shares many of its functions with IL-2, which is partly due to the shared use of receptor subunits on target cells, and serves as a growth and survival factor for T lymphocytes. The type IIL-15 receptor is composed of the IL-2R β and γ subunits, which form a trimeric complex with the high affinity IL-15Rα chain. The expression of IL-15 is tightly regulated both at the transcriptional and translational level. The production of IL-15 is associated with immune responses against bacterial and parasitic pathogens but has also been associated with the pathology of human autoimmune diseases, in particular Rheumatoid Arthritis (RA). RA is characterized by chronic inflammation within the synovial membrane accompanied by infiltration of lymphocytes leading to progressive, erosive destruction of cartilage and underlying bone. The severity of RA is associated with the overexpression of proinflammatory cytokines within the synovial tissue, in particular tumor necrosis factor alpha (TNF α) which is thought to play a central role in maintaining the inflammatory processes within the arthritic joint. So far, little is known about the processes that initiate and perpetuate RA. IL-15 was found in the synovial tissue of RA patients where it stimulated the production of TNFα, placing IL-15 in a central position orchestrating the cytokine cascade that causes inflammation and pathology in RA. Antagonists to IL-15 may therefore have an important therapeutic potential for the treatment of RA in humans. A major aim of this project has been to clone and express a recombinant IL-15 antagonist to use as a therapeutic agent in a murine model of RA closely related to the human disease, collagen-induced arthritis (CIA). A soluble IL-15Rα was cloned from a murine macrophage cell line and expressed in a bacterial expression system. The resulting protein has a molecular weight of 26kD and bound to IL-15 specifically. It also had a neutralizing effect on IL-15-induced proliferation of T cell lines. Administration of soluble IL-15Rα to mice prevented the onset of CIA and had a suppressive effect on disease severity and incidence. Mice treated with the recombinant IL-15Rα also showed reduced serum cytokine production and altered humoral responses against collagen. These results consolidate the therapeutic potential of IL-15 antagonists for the treatment of inflammatory diseases. To further enhance the therapeutic properties of recombinant IL-15Rα, a second expression construct has been cloned fusing the extracellular region of native IL-15Rα to the constant region of the murine immunoglobulin heavy chain. This construct was expressed in a mammalian expression system and results in a product of 66kD, which also bound to IL-15. The generation of knockout mice by gene targeting is a powerful tool to study the function of gene products in vivo. The Cre/lox system provides a novel strategy to generate inducible and tissue specific genomic alterations that allow the detailed analysis of gene function. The second part of this project was concerned with the generation of a mouse model lacking IL-15Rα in a tissue specific way by conditional mutagenesis in embryonic stem (ES) cells. Using cDNA encoding the extracellular domain of IL-15Rα as a radiolabeled probe, a murine genomic library was screened. Two clones containing part of the gene encoding IL-15Rα were characterized. A DNA construct was cloned to target the IL-15Rα gene in murine ES cells. Homologous recombination of the construct with the target locus resulted in the flanking of the critical regions of the IL-15Rα-gene by loxP sites. Cre-mediated recombination in vitro caused the deletion of loxP site flanked sequences within the genome of the targeted clone. Using this technique, two ES cell clones have been generated that allow the generation of mice that either lack IL-15Rα in all tissues or are suitable for conditional mutagenesis mediated by Cre recombinase. The resulting model may provide a useful tool to study the effects of IL-15 in inflammatory processes in vivo.

Burkholderia pseudomallei is a gram-negative opportunistic soil pathogen that causes the life-threatening disease melioidosis. It is endemic in Northern Australia and Southeast Asia but can be found throughout many other regions in the world. Diabetes mellitus is a predisposing risk factor for infection with this organism and it has been demonstrated that diabetic males are particularly susceptible to severe infection. Previous research suggested that monocytes isolated from the whole blood of diabetic males demonstrated a decreased ability to produce the proinflammatory cytokines IL-1β and IL-8. We hypothesized that monocyte-derived macrophages from diabetic males would also secrete lower levels of pro-inflammatory cytokines and that this difference between gender and diabetic state would be more pronounced compared to those seen previously with monocytes. Twenty volunteer with type I diabetes mellitus (ten males and ten females), along with twenty healthy age- and gender-matched controls donated blood for this study. Monocytes were collected from whole blood and allowed to differentiate into macrophages with the use of human recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF). Macrophages were then divided into groups and infected with B. pseudomallei, B. thailandensis (a closely related by non-pathogenic bacterium that inhabits similar niches), and E. coli. An uninfected control was used as well. At six hours post-infection, mRNA was collected from all cells and qPCR was performed to determine cytokine expression levels. All mRNA values collected from cells which had been infected with bacterial agents were normalized against the corresponding concentrations of mRNA from mock-infected cells. Mean log fold increases in both IL-1β and IL-8 were computed and compared. Preliminary testing showed decreased levels of both IL-1β and IL-8 from B. pseudomallei-infected macrophages isolated from a diabetic male compared to the healthy, age-matched male control. Surprisingly, results from all forty donors demonstrated that gender and diabetic state were not significant factors in the proinflammatory responses of macrophages infected with B. pseudomallei, although further testing is needed to determine if these results were influenced by experimental parameters.

yes / Purpose.: The aim of this work was to develop an in vitro cornea model to study the effect of proinflammatory cytokines on wound healing. Methods.: Initial studies investigated how to maintain the ex vivo models for up to 4 weeks without loss of epithelium. To study the effect of cytokines, corneas were cultured with the interleukins IL-17A, IL-22, or a combination of IL-17A and IL-22, or lipopolysaccharide (LPS). The effect of IL-17A on wound healing was then examined. Results.: With static culture conditions, organ cultures deteriorated within 2 weeks. With gentle rocking of media over the corneas and carbon dioxide perfusion, the ex vivo models survived for up to 4 weeks without loss of epithelium. The cytokine that caused the most damage to the cornea was IL-17A. Under static conditions, wound healing of the central corneal epithelium occurred within 9 days, but only a single-layered epithelium formed whether the cornea was exposed to IL-17A or not. With rocking of media gently over the corneas, a multilayered epithelium was achieved 9 days after wounding. In the presence of IL-17A, however, there was no wound healing evident. Characterization of the cells showed that wherever epithelium was present, both differentiated cells and highly proliferative cells were present. Conclusions.: We propose that introducing rocking to extend the effective working life of this model and the introduction of IL-17A to this model to induce aspects of inflammation extend its usefulness to study the effects of agents that influence corneal regeneration under normal and inflamed conditions.

Yes / Type 2 diabetes mellitus (T2DM) is increasing worldwide, and it is associated with increased risk of coronary artery disease (CAD). For T2DM patients, the main surgical intervention for CAD is autologous saphenous vein grafting. However, T2DM patients have increased risk of saphenous vein graft failure (SVGF). While the mechanisms underlying increased risk of vascular disease in T2DM are not fully understood, hyperglycaemia, insulin resistance, and hyperinsulinaemia have been shown to contribute to microvascular damage, whereas clinical trials have reported limited effects of intensive glycaemic control in the management of macrovascular complications. This suggests that factors other than glucose exposure may be responsible for the macrovascular complications observed in T2DM. SVGF is characterised by neointimal hyperplasia (NIH) arising from endothelial cell (EC) dysfunction and uncontrolled migration and proliferation of vascular smooth muscle cells (SMCs). This is driven in part by proinflammatory cytokines released from the activated ECs and SMCs, particularly interleukin 6 (IL-6). IL-6 stimulation of the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT) pathway is a key mechanism through which EC inflammation, SMC migration, and proliferation are controlled and whose activation might therefore be enhanced in patients with T2DM. In this review, we investigate how proinflammatory cytokines, particularly IL-6, contribute to vascular damage resulting in SVGF and how suppression of proinflammatory cytokine responses via targeting the JAK/STAT pathway could be exploited as a potential therapeutic strategy. These include the targeting of suppressor of cytokine signalling (SOCS3), which appears to play a key role in suppressing unwanted vascular inflammation, SMC migration, and proliferation. / FTM is supported by a University of Botswana PhD scholarship.

A large number of cytokines are expressed in the feet and hands joints of patients with Rheumatoid arthritis. It is necessary to study the new cytokines which may help in prognosis and diagnosis of this autoimmune disease. Omentin1 and Interleukin 20 are the new cytokines and their expressions may have a role in the expression of proinflammatory cytokines; IL-1, IL-6 and TNF, in different cell tissues such as synovial fibroblasts, chondrocytes, peripheral blood mononuclear cells and, sera. It is conceivable that these biomarkers may be used in biological therapies.

Background: Psychiatric diseases such as bipolar disorder, major depressive disorder (MDD)and schizophrenia are chronic ailments that severely affect daily function and quality of life. A relationship between elevated levels of proinflammatory cytokines and these disorders hasbeen suggested in several studies. Lithium is used as a treatment in bipolar disorder, and as anadjunctive treatment in MDD and schizophrenia. Despite the extensive use of lithium, it’smechanism of action is not fully understood. One of the proposed hypotheses of lithium’smechanism of action is reduction in the levels of proinflammatory cytokines. Aim: The aim of this systematic literature review is to describe the effects of lithium onproinflammatory cytokines (IL-1, IL-6, INF- γ, TNF) in bipolar disorder, MDD andschizophrenia. Methods: The study was conducted through a search in the electronic database PubMed.Using the PICOS format, inclusion and exclusion criteria were specified. Search words andfilters were combined using both Medical Subject Headings (MeSH) terms and free textsearch words. The search initially resulted in 105 articles and through inclusion and exclusioncriteria full-text articles were estimated for eligibility. Risk of bias was estimated using theCochrane Handbook. Results: A total of 10 eligible articlets were included in this study. Nine out of 10 articlesinvestigated bipolar patients, and one article investigated patients with MDD. No article investigated patients with schizophrenia. Four out of 9 articles regarding bipolar patientsreported a significant decrease in some proinflammatory cytokines after lithiumtreatment, 4 articles reported a significant increase, and one article reported no change in theproinflammatory cytokines. In two well conducted studies where bipolar disorder wasinvestigated, lithium had differential effects, namely decreasing proinflammatory cytokines inlithium responders compared to lithium non-responders. No significant change inproinflammatory cytokine levels after lithium treatment were found in the article studyingMDD patients. Conclusions: The results indicated that lithium may have different effects depending onwhich specific cytokine was studied and on the specific characteristics of the studiedpopulation. Therefore, the outcomes of our review cannot unequivocally answer whetherlithium acts by increasing or decreasing proinflammatory cytokines, or both depending on theexperimental conditions. Further research is needed to fully elucidate the relationship betweenlithium and proinflammatory cytokines in bipolar disorder, MDD and schizophrenia.

A sepse é caracterizada por uma produção excessiva de mediadores inflamatórios, acompanhada de taquicardia e hipotensão. Experimentalmente, a administração de endotoxina (Lipopolissacarídeo, LPS) em doses relativamente elevadas induz choque endotoxêmico, sendo um bom modelo de estudo da sepse. Diversos grupos têm demonstrado ações antiinflamatórias e antitumorais do citral, um composto do óleo essencial de Cymbopogon citratus. Nosso laboratório demonstrou ação antipirética do citral em modelo de febre induzida por LPS, acompanhada de redução nos níveis de citocinas plasmáticas e de prostaglandina E2 (PGE2) no plasma e área pré óptica do hipotálamo (POA), importante região termorregulatória. A hipótese testada neste trabalho foi a de que o citral atenua a hipotensão provocada pela endotoxina, além de amenizar as alterações termoregulatórias. Todos os procedimentos foram executados de acordo com os princípios éticos de experimentação animal, aprovados pelo comitê de ética local (CEUA 2015.1 1214 58-2). Foi realizado o implante de cânulas na artéria e veia femoral para registro da pressão arterial e administração de LPS (1,5 mg/kg) ou salina apirogênica 0,9% além do implante de datalogger na cavidade peritoneal de ratos Wistar, para registro da temperatura corporal. No dia do registro, 30 minutos antes da administração de LPS ou salina, os animais receberam citral (100 mg/kg) ou tween 80 a 1% (veículo) por via oral. Os parâmetros cardiovasculares e temperatura corporal foram registrados por 300 minutos após os respectivos tratamentos. Os valores de pressão arterial média (PAM) e frequência cardíaca (FC) foram coletados a cada 10 minutos após o tratamento e a temperatura corporal foi registrada pelo datalogger em intervalos de 5 minutos. Em outro protocolo foi realizado apenas o implante de cânula na veia femoral dos animais de todos os grupos para administração de LPS ou salina, coleta de sangue para dosagem de interleucina 6, PGE2, nitrito e nitrato e corticosterona e coleta do encéfalo para dosagem de PGE2 e PGD2. As diferenças estatísticas entre os grupos foram analisadas pelo teste ANOVA two-way seguido por pós teste de Newman-Keuls, com o nível de significância adotado de p < 0,05. A administração de LPS provocou queda na PAM eaumento na FC. Tais respostas não foram afetadas pela administração prévia de citral. O LPS também induziu febre e aumento nas concentrações plasmáticas de interleucina - 6 (IL-6), óxido nítrico (NO), PGE2 e corticosterona. Esses parâmetros não foram alterados pela pré- administração de Citral. No entanto, o citral provocou redução na produção de PGD2 naPOA, sem alterar a de PGE2 nesta região. Podemos concluir que o citral não previne as alterações nos parâmetros cardiovasculares no modelo de endotoxemia em ratos, porém reduz a produção de um mediador termorregulatório e inflamatório do sistema nervoso central (a PGD2), sem alterar a produção de outros mediadores inflamatórios a nível periférico (no plasma). Portanto, em um modelo mais agressivo de inflamação sistênica o citral não se mostrou suficiente para proteger o organismo das ações deletérias do LPS. / Sepsis is characterized by the overproduction of inflammatory mediators, accompanied by tachycardia and hypotension. Experimentally, administration of endotoxin (Lipopolysaccharide, LPS) in relatively high doses induces endotoxemic shock, a widely used model of sepsis in rats. Several groups have demonstrated anti-inflammatory and antitumor roles of citral, an essential oil compound of Cymbopogon citratus. Emilio-Silva et al. (2017) have shown an antipyretic role of citral in a model of LPS-induced fever, accompanied by a reduction of cytokines and prostaglandin E2 plasma levels and in the preoptic area of hypothalamus (POA), the hierarchically most important thermoregulatory region. We hypothesized that citral attenuates the LPS-induced hypotension, besides mitigating the thermoregulatory adjustments in rats. All procedures were performed in agreement with ethical guidelines for animal experimentation aproved by the local ethical committee (CEUA 2015.1 1214 58-2). Femoral artery and vein were implanted with cannulas for blood pressure recording and LPS (1.5 mg/kg) or 0.9% apyrogenic saline injection. In a second surgical procedure a datalogger was implanted into the peritoneal cavity for measurements of body temperature. All surgical procedures were performed under Ketamin/xilazin (100/10 mg/kg) anesthesia. One day after arterial catheterization, 30 minutes prior to LPS or saline administration, the animals received either citral (100 mg / kg) or 1% tween 80 (vehicle) oralstarly. The cardiovascular parameters and body temperature were recorded for 300 minutes after the respective treatments. Mean blood pressure (MAP) and heart rate (HR) were collected every 10 minutes after treatments and body temperature was recorded by the datalogger at 5 minute intervals. Blood samples were obtained in another set of rats for interleukin-6, PGE2, nitrite and nitrate and corticosterone analyses. The brain was removed for PGE2 and PGD2 analyses. Statistical differences between groups were analyzed by the two-way or one-way ANOVA test followed by Newman-Keuls post-test, with significance level adopted at p <0.05. As expected, LPS administration caused a decrease in MAP and an increase in HR, and these responses were not affected by citral. LPS also induced fever and increased plasma levels of interleukin - 6 (IL - 6), nitric oxide (NO), prostaglandin E 2 andcorticosterone. These parameters were also not altered by citral. On the other hand, citral caused a reduction in prostaglandin D2 concentration in the POA, but failed to alter PGE2 levels in this region. Our data are consistent with the notion that citral does not affect changes in cardiovascular and thermoregulatory parameters. Consistently, citral also caused no changes in both LPS-induced peripheral inflammatory mediators (in plasma) and in the POA, except PGD2. Therefore, in our model which mimetic a fairly critical situation, citral may not be sufficient to protect the organism from the deleterious actions of LPS. Financial support: FAPESP / CAPES.