Interleukin-1 beta is a proinflammatory cytokine released by activated immune cells. In addition to orchestrating immune responses to infection, interleukin-1 beta is a key mediator of immune-to-brain communication. Interleukin-1 beta and endotoxin (which releases IL1 beta from immune cells) cause centrally mediated illness responses such as fever, aphagia, etc. These effects are blocked by intraperitoneal IL1 receptor antagonist (IL1ra), suggesting critical involvement of peripheral IL1 receptors. Centrally mediated illness responses are also blocked by vagotomy, suggesting that IL1 beta directly or indirectly activates vagal afferents. To test for IL1 beta binding whole vagus (abdominal, laryngeal, and thoracic) and sections of hepatic vagus and liver hilus were incubated with biotinylated IL1ra and processed for avidin-biotin complex (ABC) or avidin-FITC histochemistry. Glomus cells of vagal paraganglia were labeled in all regions of the vagus. Biotinylated IL1ra also labeled smooth muscle and endothelial cells of blood vessels and lymphoid tissues. No label was present in omission or competition controls. These data suggest that centrally mediated illness responses result from IL1 activation of vagal paraganglia.

The processing of precursor interleukin 1 beta (IL1 beta) by elastase, cathepsin G, and collagenase, the major proteases released at sites of inflammation, was investigated using recombinant pro-IL1 beta. Each of these proteases cleaved the 31-kDa inactive precursor to a form similar in size and specific activity (greater than 10(8) units/mg) to the 17-kDa mature protein isolated from activated monocytes. Elastase, collagenase, and cathepsin G cleaved the IL1 beta precursor at distinct sites which are amino-terminal to the monocyte-processing site, Ala-117 (Cameron, P., Lumjuco, G., Rodkey, J., Bennett, C., and Schmidt, J. A. (1985) J. Exp. Med. 162, 790-801). Amino-terminal sequencing of the products of digestion by elastase and cathepsin G determined that resultant active IL1 beta proteins contained an additional 13 or 3 amino acids relative to mature IL1 beta. Synovial fluid collected from patients with inflammatory polyarthritis and bronchoalveolar lavage fluid from patients with sarcoidosis supplied similar processing activity(s). Control fluids from patients who had no symptoms of inflammatory disease did not exhibit processing activity. Lavage fluids that processed precursor IL1 beta were demonstrated to contain cathepsin G and/or elastase activity, whereas controls were negative. Because a significant fraction of IL1 beta may be secreted from monocytes as the inactive 31-kDa precursor (Hazuda, D. J., Lee, J. C., and Young, P. R. (1988) J. Biol. Chem. 263, 8473-8479, Bomford, R., Absull, E., Hughes-Jenkins, C., Simpkin, D., and Schmidt, J. (1987) Immunology 62, 543-549, and Mizel, S. B. (1988) in Cellular and Molecular Aspects of Inflammation Poste, G., and Crooke, S., eds) pp. 75-93, Plenum Publishing Corp., New York), these results suggest that in vivo the IL1 beta precursor can be processed after secretion by any of several proteases released at inflammatory sites.

Toll-like receptors (TLRs) play a key role in pathogen recognition and regulation of the innate and adaptive immune responses. Although TLR expression and signaling have been investigated in blood cells, it is currently unknown whether their bone marrow ancestors express TLRs and respond to their ligands. Here we found that TLRs (e.g. TLR4, TLR7 and TLR8) were expressed by freshly isolated human bone marrow (BM) hematopoietic CD34+ progenitor cells. Incubation of these primitive cells with TLR ligands such as immunostimulatory small interfering RNAs and R848, a specific ligand for TLR7/8, induced cytokine production (e.g. IL1-beta, IL6, IL8, TNF-alpha, GM-CSF). Moreover, TLR7/8 signaling induced the differentiation of BM CD34+ progenitors into cells with the morphology of macrophages and monocytic dendritic precursors characterized by the expression of CD13, CD14 and/or CD11c markers. By contrast, R848 ligand did not induce the expression of glycophorin A, an early marker for erythropoiesis. Collectively, the data indicate for the first time that human BM CD34+ progenitor cells constitutively express functional TLR7/TLR8, whose ligation can induce leukopoiesis without the addition of any exogenous cytokines. Thus, TLR signaling may regulate BM cell development in humans.

Expression of cytokine genes in freshly isolated T cell subsets in the autoimmune lpr mouse has been studied to determine what factors may be produced by these cells in vivo. RNA prepared from T cell subsets from diseased lpr mice and from the normal congenic strain, MRL/n, was tested for the presence of cytokine-specific message using the polymerase chain reaction. Cells of the expanded abnormal T cell subset were shown to express genes encoding interferon (IFN)-gamma, tumor necrosis factor (TNF)-beta, TNF-alpha and interleukin (IL)6, cytokines which are associated with inflammatory immune responses. These cells may thus play an important role in exacerbation of the pathological symptoms of the systemic autoimmune disease. These cells expressed no detectable IL1, IL2, IL3, IL4 or IL5. Phenotypically normal CD4+ and CD8+ T cells from both lpr and MRL/n also contained transcripts for IFN-gamma, TNF-alpha, TNF-beta and IL6. IL2 mRNA was found almost exclusively in the CD4+ subset, indicating that the CD8+ T cells in the lpr mouse are not highly activated through their class I major histocompatibility complex molecules to produce IL2, as could occur if a virus infection was inducing autoimmunity in these mice. Similar levels of IL2 mRNA were present in the CD4+ T cells of lpr and MRL/n mice, demonstrating that these cells are not defective in IL2 production in vivo.

The effect of interleukin-1 beta (IL 1 beta) on spatial learning was examined. In one experiment, C57BL/6 mice were given daily injections (100 ng/mouse) of recombinant murine IL1 beta prior to training on the Morris water maze. In another experiment, mice were infected with a sublethal dose of a gram-negative bacterium (Legionella pneumophila; Lp). Mice rendered ill by the infection were given either anti-IL1 beta antibodies (100 micrograms/mouse) or saline and then trained on the water maze. Results indicated that (1) exogenous IL1 beta blocked acquisition of spatial learning, (2) Lp infection attenuated learning on this task, and (3) neutralizing circulating IL1 beta in Lp-infected mice normalized learning despite the continuation of the illness. The data indicate that cognitive impairment may be a component of cytokine-mediated sickness behavior.

We examined the effect of modulating phosphoinositide 3-kinase (PI3K) activity in a murine model of cecal ligation and puncture-induced polymicrobial sepsis. Inhibition of PI3K activity with wortmannin increased serum cytokine levels and decreased survival time in septic mice. We have reported that an immunomodulator, glucan phosphate, induces protection in murine polymicrobial sepsis. We observed that glucan stimulated tissue PI3K activity, which positively correlated with increased survival in septic mice. We investigated the effect of PI3K inhibition on survival in septic mice treated with glucan. Treatment of mice with the PI3K inhibitors, wortmannin and LY294002, completely eliminated the protective effect of glucan, indicating that protection against septic mortality was mediated through PI3K. Inhibition of PI3K resulted in increased serum levels of IL1-beta, IL-2, IL-6, IL-10, IL-12, and TNF-alpha in septic mice. Apoptosis is thought to play a central role in the response to septic injury. We observed that inhibition of PI3K activity in septic mice resulted in increased splenocyte apoptosis and a change in the anatomic distribution of splenocyte apoptosis. We conclude that PI3K is a compensatory mechanism that suppresses proinflammatory and apoptotic processes in response to sepsis and/or inflammatory injury. Thus, PI3K may play a pivotal role in the maintenance of homeostasis and the integrity of the immune response during sepsis. We also observed that glucan phosphate decreased septic morbidity and mortality through a PI3K-dependent mechanism. This suggests that stimulation of the PI3K pathway may be an effective approach for preventing or treating sepsis and/or septic shock.

Interleukin 1 (IL1) is a primary regulator of inflammatory and immune responses. Via its type I receptor it activates specific protein kinases, including the NF kappa B inducing kinase (NIK) and three distinct mitogen-activated protein (MAP) kinase cascades. These modulate a number of transcription factors including NF kappa B, AP1 and CREB each of which regulate a plethora of immediate early genes central to the inflammatory response. Phase I clinical trials of the soluble type I receptor and IRAP indicate that these have potential anti-inflammatory effects.

The KBF1 factor, which binds to the enhancer A located in the promoter of the mouse MHC class I gene H-2Kb, is indistinguishable from the p50 DNA binding subunit of the transcription factor NF-kappa B, which regulates a series of genes involved in immune and inflammatory responses. The KBF1/p50 factor binds as a homodimer but can also form heterodimers with the products of other members of the same family, like the c-rel and v-rel (proto)oncogenes. The dimerization domain of KBF1/p50 is contained between amino acids 201 and 367. A mutant of KBF1/p50 (delta SP), unable to bind to DNA but able to form homo- or heterodimers, has been constructed. This protein reduces or abolishes in vitro the DNA binding activity of wild-type proteins of the same family (KBF1/p50, c- and v-rel). This mutant also functions in vivo as a trans-acting dominant negative regulator: the transcriptional inducibility of the HIV long terminal repeat (which contains two potential NF-kappa B binding sites) by phorbol ester (PMA) is inhibited when it is co-transfected into CD4+ T cells with the delta SP mutant. Similarly the basal as well as TNF or IL1-induced activity of the MHC class I H-2Kb promoter can be inhibited by this mutant in two different cell lines. These results constitute the first formal demonstration that these genes are regulated by members of the rel/NF-kappa B family.

Multiple sclerosis (MS) is an autoimmune disease characterized by peripheral activation of CD4(+) T cells that migrate into the central nervous system (CNS) and mount an autoimmune neuroinflammatory attack on myelin and oligodendrocytes. Secondary to these events, however equally destructive, is the generation of inflammatory-mediated reactive oxygen and nitrogen species generated by persistently activated microglia and astrocytes. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a basic leucine zipper transcription factor that regulates genetic expression of many protective antioxidant and detoxication enzymes. Here we describe the Nrf2 modulation of innate and adaptive immune responses in an acute autoimmune model of MS, experimental autoimmune encephalomyelitis (EAE). Wild-type (WT) mice and Nrf2 knockout mice were immunized with myelin oligodendrocyte glycoprotein (MOG 35-55) and monitored daily for clinical scores of disease. Disruption of Nrf2 resulted in a more severe clinical course, a more rapid onset, and a greater percentage of mice with the disease. Furthermore, increased immune cell infiltration and glial cell activation in spine was observed. In conjunction, we observed increased inflammatory enzyme (iNOS, phox-47, gp91-phox, and phox-67), cytokine (IFN-gamma, IL1-b, TNF-alpha, and IL-12), and chemokine (BLC and MIG) gene expression levels in the Nrf2-deficient mice compared to the WT mice, supporting the notion that Nrf2 can modulate an autoimmune neuroinflammatory response. Our results show that the absence of Nrf2 exacerbates the development of EAE and thus suggests that activation of Nrf2 may then attenuate pathogenesis of autoimmune diseases such as MS as well as other neurodegenerative diseases that present with neuroinflammation.

OBJECTIVE

We investigated the effect of SB 203580, a pharmacological inhibitor of p38 mitogen-activated protein kinase (MAPK), on cardiac inflammation, cardiac fibrosis, and left ventricular function using an animal model of diabetic cardiomyopathy.

METHODS

Diabetes mellitus was induced by streptozotocin (50 mg/kg i.p. for 5 days) in 20 C57/BL6J mice. Diabetic mice were treated daily with the p38 MAPK inhibitor SB 203580 (1 mg/kg daily, n=10) or with placebo (n=10) and were compared to non-diabetic controls. Left ventricular function was measured by pressure-volume loops after 8 weeks of diabetes mellitus. The parameters for systolic function were the end systolic pressure-volume relationship (ESPVR) and the left ventricular end systolic pressure. The parameters for diastolic function were the left ventricular end diastolic pressure and the end diastolic pressure-volume relationship (EDPVR). Cardiac tissue was analysed by ELISA for the protein content of the cytokines TNF-alpha, IL6, <em>IL1</em>-<em>beta</em>, and TGF-<em>beta</em>1. Phosphorylation of MAPK p38 was analysed by western blot, and the total cardiac collagen content was analysed by Sirius red staining.

RESULTS

Left ventricular dysfunction was documented by impaired ESPVR and EDPVR. Cardiac cytokine levels and cardiac fibrosis were increased in diabetic animals compared to controls. Treatment with the p38 inhibitor normalised cardiac cytokine levels and improved systolic function, but did not change cardiac fibrosis and diastolic dysfunction compared to placebo.

CONCLUSIONS

Pharmacological inhibition of p38 MAPK prevents cardiac inflammation and attenuates left ventricular dysfunction in diabetic cardiomyopathy.

Human mesenchymal stem/precursor cells (MSC) are similar to some other stem/progenitor cells in that they compact into spheres when cultured in hanging drops or on nonadherent surfaces. Assembly of MSC into spheres alters many of their properties, including enhanced secretion of factors that mediate inflammatory and immune responses. Here we demonstrated that MSC spontaneously aggregated into sphere-like structures after injection into a subcutaneous air pouch or the peritoneum of mice. The structures were similar to MSC spheres formed in cultures demonstrated by the increased expression of genes for inflammation-modulating factors TSG6, STC1, and COX2, a key enzyme in production of PGE2. To identify the signaling pathways involved, hanging drop cultures were used to follow the time-dependent changes in the cells as they compacted into spheres. Among the genes upregulated were genes for the stress-activated signaling pathway for IL1α/β, and the contact-dependent signaling pathway for Notch. An inhibitor of caspases reduced the upregulation of IL1A/B expression, and inhibitors of IL1 signaling decreased production of PGE2, TSG6, and STC1. Also, inhibition of IL1A/B expression and secretion of PGE2 negated the anti-inflammatory effects of MSC spheres on stimulated macrophages. Experiments with γ-secretase inhibitors suggested that Notch signaling was also required for production of PGE2 but not TSG6 or STC1. The results indicated that assembly of MSC into spheres triggers caspase-dependent IL1 signaling and the secretion of modulators of inflammation and immunity. Similar aggregation in vivo may account for some of the effects observed with administration of the cells in animal models.

Theiler murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD) is a mouse model of chronic-progressive multiple sclerosis (MS) characterized by Th1-mediated CNS demyelination and spastic hindlimb paralysis. Existing MS therapies reduce relapse rates in 30% of relapsing-remitting MS patients, but are ineffective in chronic-progressive disease, and their effects on disability progression are unclear. Experimental studies demonstrate cannabinoids are useful for symptomatic treatment of spasticity and tremor in chronic-relapsing experimental autoimmune encephalomyelitis. Cannabinoids, however, have reported immunosuppressive properties. We show that the cannabinoid receptor agonist, R+WIN55,212, ameliorates progression of clinical disease symptoms in mice with preexisting TMEV-IDD. Amelioration of clinical disease is associated with downregulation of both virus and myelin epitope-specific Th1 effector functions (delayed-type hypersensitivity and IFN-gamma production) and the inhibition of CNS mRNA expression coding for the proinflammatory cytokines, TNF-alpha, IL1-beta, and IL-6. Clinical trials investigating the therapeutic potential of cannabinoids for the symptomatic treatment of MS are ongoing, and this study demonstrates that they may also have potent immunoregulatory properties.

Astrocytes express high levels of connexin43, a protein that forms two types of channels: gap junction channels for direct intercellular communication, and hemichannels for exchanges with the extracellular space. Inflammation induces connexin43 hemichannel activation, which has been proposed to be involved in neuroglial interactions. Here, we investigated the contribution of connexin43 to NMDA-induced excitotoxicity in neuron/astrocyte co-cultures, after treatment with a pro-inflammatory cytokine mixture, containing TNF-alpha and IL1-beta (Mix), that stimulated astroglial connexin43 hemichannel activity. Interestingly, NMDA treatment induced a higher amount of neurotoxicity in Mix-treated co-cultures than in untreated ones, whereas this extent of neurotoxicity was absent in enriched neuron cultures or in co-cultures with connexin43 knock-out astrocytes. Furthermore, application of connexin43 hemichannel blockers or a synthetic cannabinoid prevented the Mix-induced potentiated NMDA neurotoxicity. Altogether, these data demonstrate that inflammation-induced astroglial hemichannel activation plays a critical role in neuronal death and suggest a neuroprotective role of connexin43 hemichannel blockade.

BACKGROUND

Monosodium urate (MSU) and calcium pyrophosphate dihydrate (CPPD) crystal-induced interleukin 1 beta (IL1beta) release contributes to inflammation in subcutaneous air pouch and peritoneal models of acute gout and pseudogout. However, consequences of IL1 inhibition have not been explored in more clinically relevant models of crystal-induced arthritis.

OBJECTIVE

To develop a novel mouse model of acute gouty ankle arthritis and use it to assess the effects of genetic deletion of IL1 receptor type (IL1R1) and of exogenous mIL1 Trap (a high-affinity blocker of mouse IL1alpha and IL1beta) on pain, synovitis and systemic inflammatory biomarkers.

METHODS

MSU crystals were injected into the mouse ankle joint and pain and ankle swelling were measured over 4 days. The effects of IL1 inhibition were determined in this model, and in the comparator models of crystal-induced peritonitis and subcutaneous air pouch inflammation.

RESULTS

Both IL1R1-null mice and mice pretreated with mIL1 Trap showed reduced neutrophil influx in MSU and CPPD crystal-induced peritonitis and air pouch models (p<0.05). In the ankle joint model, both IL1R1 knockout mice and pretreatment with mIL1 Trap were associated with significant reductions in MSU crystal-induced elevations in hyperalgesia, inflammation, serum amyloid A and the levels of multiple inflammatory cytokines and chemokines (p<0.05). Additionally, it was found that administration of mIL1 Trap after MSU crystal injection reduced established hyperalgesia and ankle swelling.

CONCLUSIONS

IL1 inhibition both prevented and relieved pain and ankle joint inflammation in response to intra-articular MSU crystals in mice. Results suggested that IL1 Trap has the potential to both prevent and treat gouty arthritis.

BACKGROUND

Disc degeneration (DD) is a multifaceted chronic process that alters the structure and function of the intervertebral discs and can lead to painful conditions. The pathophysiology of degeneration is not well understood, but previous studies suggest that certain genetic polymorphisms may be important contributing factors leading to an increased risk of DD.

OBJECTIVE

To review the genetic factors in DD with a focus on polymorphisms and their putative role in the pathophysiology of degeneration. Elucidating the genetic components that are associated with degeneration could provide insights into the mechanism of the process. Furthermore, defining these relationships and eventually using them in a clinical setting may allow an identification and early intervention for those who are at a high risk for painful DD.

METHODS

Literature review.

METHODS

This literature review focused on the studies concerning genetic polymorphisms and their associations with DD.

RESULTS

Genetic polymorphisms in 20 genes have been analyzed in association with DD, including vitamin D receptor, growth differentiation factor 5 (GDF5), aggrecan, collagen Types I, IX, and XI, fibronectin, hyaluronan and proteoglycan link protein 1 (HAPLN1), thrombospondin, cartilage intermediate layer protein (CILP), asporin, MMP1, 2, and 3, parkinson protein 2, E3 ubiquitin protein ligase (PARK2), proteosome subunit β type 9 (PSMB9), tissue inhibitor of metalloproteinase (TIMP), cyclooxygenase-2 (COX2), and IL1α, IL1β, and IL6. Each genetic polymorphism codes for a protein that has a functional role in the pathogenesis of DD.

CONCLUSIONS

There are known associations between several genetic polymorphisms and DD. Of the 20 genes analyzed, polymorphisms in vitamin D receptor, aggrecan, Type IX collagen, asporin, MMP3, IL1, and IL6 show the most promise as functional variants. Genetic studies are crucial for understanding the mechanism of the degeneration. This genetic information could eventually be used as a predictive model for determining a patient's risk for symptomatic DD.

The effects of the cytokines interleukin-1 and -6 (IL1 beta, IL6; 100 ng) on spatial learning were examined in the Morris water maze. Intracerebroventricular injection of IL1 or IL6 before the training on day 1 did not influence the acquisition of spatial navigation. However, IL1 administered at 60 min, but not immediately before the training, resulted in impaired performance of spatial navigation the following day. In contrast, IL6 administered at both times had no effect. In a second experiment the same doses of IL1 and IL6 increased the body temperature of rats in a time-related fashion. The temperature effect of IL1 developed after a delay of 120 min, while the IL-6-effect was immediate. Comparable behavioral changes might accompany infections or inflammatory diseases and therapeutic cytokine administration.

Understanding transcriptional changes in brain after ischemia may provide therapeutic targets for treating stroke and promoting recovery. To study these changes on a genomic scale, oligonucleotide arrays were used to assess RNA samples from periinfarction cortex of adult Sprague-Dawley rats 24 h after permanent middle cerebral artery occlusions. Of the 328 regulated transcripts in ischemia compared with sham-operated animals, 264 were upregulated, 64 were downregulated, and 163 (49.7%) had not been reported in stroke. Of the functional groups modulated by ischemia: G-protein-related genes were the least reported; and cytokines, chemokines, stress proteins, and cell adhesion and immune molecules were the most highly expressed. Quantitative reverse transcription polymerase chain reaction of 20 selected genes at 2, 4, and 24 h after ischemia showed early upregulated genes (2 h) including Narp, Rad, G33A, HYCP2, Pim-3, Cpg21, JAK2, CELF, Tenascin, and DAF. Late upregulated genes (24 h) included Cathepsin C, Cip-26, Cystatin B, PHAS-I, TBFII, Spr, PRG1, and LPS-binding protein. Glycerol 3-phosphate dehydrogenase, which is involved in mitochondrial reoxidation of glycolysis derived NADH, was regulated more than 60-fold. Plasticity-related transcripts were regulated, including Narp, agrin, and Cpg21. A newly reported lung pathway was also regulated in ischemic brain: C/EBP induction of Egr-1 (NGFI-A) with downstream induction of PAI-1, VEGF, ICAM, IL1, and MIP1. Genes regulated acutely after stroke may modulate cell survival and death; also, late regulated genes may be related to tissue repair and functional recovery.

It is not known whether one or both of the interleukin 1 (IL1) receptors mediates the induction of the DNA-binding protein NF-kappa B. Nuclear extracts of the murine lines EL4.NOB.1 and 70Z/3, which bear the type I (80 kDa) and type II (67 kDa) IL1 receptor, respectively, were analyzed by an electrophoretic mobility shift assay. A 265-base pair sequence of the human serum amyloid A gene or a synthetic oligonucleotide each containing the NF-kappa B site were used as the DNA probes. IL1 induction of NF-kappa B was rapid (optimal at 15-30 min) and transient in both cell types. The IL1 receptor antagonist (IL1ra), which binds strongly to the type I receptor, inhibited the NF-kappa B response in both cell lines. IL1ra did not bind to the type II receptor on 70Z/3 cells as judged by competition for binding with 125I-IL1 alpha. When 125I-IL1ra binding to 70Z/3 cells was measured, a small number (10/cell) of high affinity sites (Kd = 5 x 10(-12) M) were detected. These were likely to have been type I receptor because an antibody to this inhibited the NF-kappa B induction in 70Z/3 cells (as well as EL4). Potential signal transduction mechanisms involving protein kinase C or oxygen radicals were studied. Phorbol 12-myristate 13-acetate induced NF-kappa B with a similar time course to IL1 in 70Z/3 but only after 4 h in EL4.IL1 was unaffected by a protein kinase C inhibitor (staurosporine). H2O2 did not mimic IL1, and IL1 was not inhibited by an antioxidant. The type I receptor mediates the induction of NF-kappa B in response to IL1 via a signaling mechanism that still remains to be identified.

Intraspinal injection of quisqualic acid (QUIS) produces excitotoxic injury with pathophysiological characteristics similar to those associated with ischemic and traumatic spinal cord injury (SCI). Responses to QUIS-induced injury include an inflammatory component, as well as the development of spontaneous and evoked pain behaviors. We hypothesized that QUIS-induced inflammation and subsequent gene expression contribute to the development and progression of pain-related behaviors and that blockade of inflammation-related gene expression leads to the amelioration of these behaviors. Using the QUIS model of spinal cord injury, we examined whether interleukin-10 (IL-10), a potent anti-inflammatory cytokine, is able to reduce mRNA levels of inflammatory and cell death-related genes leading to a reduction of pain behaviors. The results demonstrate that animals receiving systemic injection of IL-10, 30 minutes following QUIS-induced SCI, showed a significant delay in the onset of excessive grooming behavior, a significant reduction in grooming severity, and a significant reduction in the longitudinal extent of a pattern of neuronal loss within the spinal cord characterized as "grooming-type damage." QUIS injections also resulted in an increase in mRNA levels of interleukin-1 beta (IL-1 beta), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), CD95 ligand (CD95-L, also called FAS-L/APO-1L), and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Results of QUIS injury plus IL-10 treatment resulted in a significant downregulation of IL1-beta and iNOS mRNA and these results were supported by Western blot analysis of protein levels following IL-10 treatment. These data suggest that IL-10 reduces inflammation and that targeting injury-induced inflammation is an effective strategy for limiting the extent of neuronal damage following excitotoxic SCI and thus the onset and progression of injury-induced pain behaviors.

Matrix metalloproteinases (MMPs) are enzymes with important roles in a variety of normal physiological processes; these same enzymes are also operative in a range of pathologies. The proteins known as the tissue inhibitors of matrix metalloproteinases (TIMPs) act to limit the enzymatic function of the MMPs. MMPs and TIMPs can be divided into two groups with respect to gene expression: the majority exhibit inducible expression and a small number are produced constitutively or are expressed at very low levels and are not inducible. Among the agents that induce MMP and TIMP production are the inflammatory cytokines TNF alpha and IL1 beta. A marked cell type specificity is a hallmark of both MMP and TIMP gene expression (i.e., a limited number of cell types can be induced to make these proteins). An analysis of the control elements in the promoter regions of these proteins reveals a correlation between the presence of both AP-1 and Ets binding sites and inducible expression. The chromosomal locations of most of the MMPs and TIMPs have been verified; these data will provide the basis for investigations into possible correlations between mutations in these genes and disease states.

Sphingolipids and their synthetic enzymes are emerging as important mediators in inflammatory responses and as regulators of immune cell functions. In particular, sphingosine kinase (SK) and its product sphingosine-1-phosphate (S1P) have been extensively implicated in these processes. SK catalyzes the phosphorylation of sphingosine to S1P and exists as two isoforms, SK1 and SK2. SK1 has been shown to be activated by cytokines including tumor necrosis factor-alpha (TNF-alpha) and interleukin1-beta (IL1-beta). The activation of SK1 in this pathway has been shown to be, at least in part, required for mediating TNF-alpha and IL1-beta inflammatory responses in cells, including induction of cyclo-oxygenase 2 (COX2). In addition to their role in inflammatory signaling, SK and S1P have also been implicated in various immune cell functions including, mast cell degranulation, migration of neutrophils, and migration and maturation of lymphocytes. The involvement of sphingolipids and sphingolipid metabolizing enzymes in inflammatory signaling and immune cell functions has implicated these mediators in numerous inflammatory disease states as well. The contribution of these mediators, specifically SK1 and S1P, to inflammation and disease are discussed in this review.

BACKGROUND

The higher risk of women developing autoimmune diseases suggests that immune system is mediated by sex steroids.

OBJECTIVE

To review the effects of aging and menopause in immune system.

METHODS

A systematic review of in vitro, animal and human studies involving aging and menopause and immune system was carried out. An electronic search based on Internet search engines, MEDLINE (1966-June 2010) and the Cochrane Controlled Clinical Trials Register was done.

RESULTS

After crossing-cleaning the reference lists, a total of 688 studies dealing with immune system and menopause were identified. Of them, 30 were considered selectable. The concept of immunosenescence reflects changes in both cellular and serological immune responses throughout the process of generating specific response to foreign antigens. This may be related with a higher incidence of infectious and chronic diseases. After menopause, there is an increase in pro-inflammatory serum markers (IL1, IL6, TNF-alpha), an increase in response of the immune blood cells to these cytokines, a decrease in CD4 T and B lymphocytes and a decrease in the cytotoxic activity of NK cells. Additionally, IL-6 is a key factor in bone resorption and also seems to be associated with other diseases more common after menopause such as diabetes, atherosclerosis and cardiovascular disease.

CONCLUSIONS

Most of the studies suggested that in addition to age, in postmenopausal women, changes of the immune system have been attributed to estrogen deprivation. Furthermore, recent studies point out changes in immune response related to use or cessation of hormone replacement at menopause.

BACKGROUND

Pulmonary arterial hypertension (PAH) is a common complication for individuals with limited systemic sclerosis (lSSc). The identification and characterization of biomarkers for lSSc-PAH should lead to less invasive screening, a better understanding of pathogenesis, and improved treatment.

RESULTS

Forty-nine PBMC samples were obtained from 21 lSSc subjects without PAH (lSSc-noPAH), 15 lSSc subjects with PAH (lSSc-PAH), and 10 healthy controls; three subjects provided PBMCs one year later. Genome-wide gene expression was measured for each sample. The levels of 89 cytokines were measured in serum from a subset of subjects by Multi-Analyte Profiling (MAP) immunoassays. Gene expression clearly distinguished lSSc samples from healthy controls, and separated lSSc-PAH from lSSc-NoPAH patients. Real-time quantitative PCR confirmed increased expression of 9 genes (ICAM1, IFNGR1, IL1B, IL1IL1-beta, ICAM-1, and IL-6, and markers of vascular injury such as VCAM-1, VEGF, and von Willebrand Factor were found in lSSc-PAH subjects.

CONCLUSIONS

The gene expression and cytokine profiles of lSSc-PAH patients suggest the presence of activated monocytes, and show markers of vascular injury and inflammation. These genes and factors could serve as biomarkers of PAH involvement in lSSc.

Activated macrophages produce quinolinic acid (QUIN), a neurotoxin, in several inflammatory brain diseases including AIDS dementia complex. We hypothesized that <em>IL1</em>-<em>beta</em>, IL6, transforming growth factor (TGF-<em>beta</em>2 and platelet activating factor could increase macrophage QUIN production. And that the HIV-1 proteins Nef, Tat and gp41 may also increase synthesis of QUIN by macrophages. At 72 h there were significant increases in QUIN production in the cells stimulated with PAF (914 +/- 50 nM) and Nef (2781 +/- 162 nM), with somewhat less production by Tat stimulation (645 +/- 240 nM). The increases in QUIN production approximated in vitro concentrations of QUIN shown to be neurotoxic and correlated closely with indoleamine 2,3-dioxygenase induction. <em>IL1</em>-<em>beta</em>, IL6, TGF-<em>beta</em>2 and gp41 stimulation produced no significant increase in QUIN production. These results suggest that some of the neurotoxicity of PAF, nef and tat may be mediated by QUIN.