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Advanced glycation end-products (AGEs) are produced by non-enzymatic glycation between protein and reducing sugar such as glucose. Although glyceraldehyde-derived AGEs (Glycer-AGEs), one of the AGEs subspecies, have been reported to be involved in the pathogenesis of various age-relating diseases such as diabetes mellitus or arteriosclerosis, little is known about the pathological and physiological mechanism of AGEs in vivo. In present study, we produced 4 kinds of polyclonal antibodies against AGEs subspecies and investigated the localization of AGEs-modified proteins in rat peripheral tissues, making use of these antibodies. We found that Glycer-AGEs and methylglyoxal-derived AGEs (MGO-AGEs) were present in pancreatic islets of healthy rats, distinguished clearly into the pancreatic α and β cells, respectively. Although streptozotocin-induced diabetic rats suffered from remarkable impairment of pancreatic islets, the localization and deposit levels of the Glycer- and MGO-AGEs were not altered in the remaining α and β cells. Remarkably, the MGO-AGEs in pancreatic β cells were localized into the insulin-secretory granules. These results suggest that the cell-specific localization of AGEs-modified proteins are presence generally in healthy peripheral tissues, involved in physiological intracellular roles, such as a post-translational modulator contributing to the secretory and/or maturational functions of insulin., (Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.)

To examine the tradeoff between manual reaction times (RTs) and smooth pursuit accuracy, we manipulated manual RTs to a visual target presented during pursuit by using a deadline procedure that required different response speeds to a target (300, 400, or 500 ms). Participants attempted to pursue a moving row of circles as accurately as possible, while responding to a target within a preset time. Stimulus velocity and target position were manipulated. As the preset time became shorter, participants responded with faster manual RTs and larger pursuit velocity errors, irrespective of the stimulus velocity, indicating a tradeoff between manual RTs and pursuit accuracy. Pursuit velocity errors were also larger after target onset. These results not only suggest that attentional resources as well as spatial shifts of attention play an important role in maintaining accurate pursuit, but also support the notion that a manual RT task is useful for revealing the operation of attention during pursuit.

Glycyrrhizin (GL) is a major constituent of licorice root and has been suggested to inhibit the release of high mobility group box-1 (HMGB1), a protein considered representative of damage-associated molecular patterns. We found that GL bound HMGB1 but not RAGE with a moderate equilibrium dissociation constant value based on surface plasmon resonance analysis. This complex formation prevented HMGB1 from binding to RAGE in vitro. The effects of glycyrrhizin on traumatic brain injury (TBI) induced by fluid percussion were examined in rats or mice in the present study. GL was administered intravenously after TBI. Treatment of rats with GL dose-dependently suppressed the increase in BBB permeability and impairment of motor functions, in association with the inhibition of HMGB1 translocation in neurons in injured sites. The beneficial effects of GL on motor and cognitive functions persisted for 7 days after injury. The expression of TNF-α, IL-1β and IL-6 in injured sites was completely inhibited by GL treatment. In RAGE-/- mice, the effects of GL were not observed. These results suggested that GL may be a novel therapeutic agent for TBI through its interference with HMGB1 and RAGE interaction., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

We examined skill-based differences in the anticipation of ball direction during the catching of a grounder in baseball. In Experiment 1, we used film stimuli which included a sequence of pitching and hitting action from the shortstop's customary perspective, and participants judged the ball's direction (left or right). Also, we used white-circle stimuli, and participants reported whether the circle was displaced to the left or to the right. Baseball players responded faster than non-players in the film task, but there was no significant difference between the two groups in the white-circle task. In Experiment 2, we used film stimuli which were cut off at four different temporal occlusion periods to examine the time of extraction of important visual cues. Accuracy exceeded the chance level prior to the bat-ball contact in both groups, but was earlier for players than for non-players. Our results suggest that players may extract anticipatory visual cues more effectively and earlier than non-players.

We investigated the expression and localization of high-mobility group box chromosomal protein-1 (HMGB-1) in human osteoarthritic (OA) cartilage in relation to the histopathological grade of cartilage destruction, and examined the role of HMGB-1 in the regulation of proinflammatory cytokine expression in chondrocytes. An immunohistochemical study demonstrated that total HMGB-1-positive cell ratios increase as the Osteoarthritis Research Society International (OARSI) histological grade increased. The population of cytoplasmic HMGB-1-positive chondrocytes was especially increased in the deep layers of higher-grade cartilage. The ratios and localization of receptors for advanced glycation end products (RAGE) expression by chondrocytes in Grade 2, 3, and 4 were significantly higher than those in Grade 1. In vitro stimulation with IL-1β, but not TNFα, significantly upregulated the expression of HMGB-1 mRNA by human OA chondrocytes. Both IL-1β and TNFα promoted the translocation of HMGB-1 from nuclei to cytoplasm. IL-1β and TNFα secretions were stimulated at higher levels of HMGB-1. The results of our study suggest the involvement of HMGB-1 in the pathogenesis of cartilage destruction in OA.

Cell-to-cell interaction through binding of intercellular adhesion molecule-1 (ICAM-1) and CD40 on monocytes to their ligands on T-cells plays crucial roles in cytokine production. Advanced glycation end products (AGEs) subtypes induce complications in diabetes. In a previous study, we found that glyceraldehyde-derived AGE (AGE-2) and glycolaldehyde-derived AGE (AGE-3) at 100 microg/ml induced the expressions of ICAM-1 and CD40 on monocytes and the production of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha in human peripheral blood mononuclear cells. beta(2)-adrenoceptor stimulation has been demonstrated to modulate the production of inflammatory mediators. In the present study, we found that norepinephrine, epinephrine and isoproterenol inhibited AGE-2- and AGE-3-induced adhesion expression and cytokine production in a concentration-dependent manner. The action of these catecholamines was antagonized by beta(2)-adrenoceptor antagonist, but not by alpha(1)-, alpha(2)- and beta(1)-adrenoceptor antagonist. beta(2)-adrenoceptor agonists, salbutanol and terbutaline inhibited AGE-2- and AGE-3-induced adhesion expression and cytokine production, but alpha(1)-, alpha(2)- and beta(1)-adrenoceptor agonist had no effect, indicating that the stimulation of beta(2)-adrenoceptor might improve AGEs-initiated complications in diabetes., (Copyright (c) 2009 Elsevier B.V. All rights reserved.)

Angiogenesis involves complex processes mediated by several factors and is associated with inflammation and wound healing. High mobility group box 1 (HMGB1) is released from necrotic cells as well as macrophages and plays proinflammatory roles. In the present study, we examined whether HMGB1 would exhibit angiogenic activity in a matrigel plug assay in mice. HMGB1 in combination with heparin strongly induced angiogenesis, whereas neither HMGB1 nor heparin alone showed such angiogenic activity. The heparin-dependent induction of angiogenesis by HMGB1 was accompanied by increases in the expression of tumor necrosis factor-alpha (TNF-alpha) and vascular endothelial growth factor-A120 (VEGF-A120). It is likely that the dependence of the angiogenic activity of HMGB1 on heparin was due to the efficiency of the diffusion of the HMGB1-heparin complex from matrigel to the surrounding areas. VEGF-A165 possessing a heparin-binding domain showed a pattern of heparin-dependent angiogenic activity similar to that of HMGB1. The presence of heparin also inhibited the degradation of HMGB1 by plasmin in vitro. Taken together, these results suggested that HMGB1 in complex with heparin possesses remarkable angiogenic activity, probably through the induction of TNF-alpha and VEGF-A120.

Interaction between the receptor for advanced glycation end products (RAGE) and its ligands has been implicated in the pathogenesis of various inflammatory disorders. In this study, we establish an in vitro binding assay in which recombinant human high-mobility group box 1 (rhHMGB1) or recombinant human S100A12 (rhS100A12) immobilized on the microplate binds to recombinant soluble RAGE (rsRAGE). The rsRAGE binding to both rhHMGB1 and rhS100A12 was saturable and dependent on the immobilized ligands. The binding of rsRAGE to rhS100A12 depended on Ca2+ and Zn2+, whereas that to rhHMGB1 was not. Scatchard plot analysis showed that rsRAGE had higher affinity for rhHMGB1 than for rhS100A12. rsRAGE was demonstrated to bind to heparin, and rhS100A12, in the presence of Ca2+, was also found to bind to heparin. We examined the effects of heparin preparations with different molecular sizes - unfractionated native heparin (UFH), low molecular weight heparin (LMWH) 5000Da, and LMWH 3000Da - on the binding of rsRAGE to rhHMGB1 and rhS100A12. All 3 preparations concentration-dependently inhibited the binding of rsRAGE to rhHMGB1 to a greater extent than did rhS100A12. These results suggested that heparin's anti-inflammatory effects can be partly explained by its blocking of the interaction between HMGB1 or S100A12 and RAGE. On the other hand, heparin would be a promising effective remedy against RAGE-related inflammatory disorders.

Lipopolysaccharide (LPS) is one of the major causes of septic shock. The polymyxin B-immobilized filter column (PMX) was developed for the adsorption of endotoxin by direct hemoperfusion and has been used for the treatment of LPS-induced septic shock. In this study, we demonstrated that PMX also specifically bound monocytes from the peripheral blood leukocytes of septic patients by mean of an analysis of bound cells using immunocytochemical and electron microscopic techniques. The specific removal of monocytes from septic patients may produce beneficial effects by reducing the interaction between monocytes and functionally associated cells including vascular endothelial cells.

We examined the effects of beta2-adrenergic receptor (beta2-AR) agonists on monocyte-derived cytokines, interleukin (IL)-18 and IL-12 production in lipopolysaccharide (LPS)-stimulated monocytes derived from human peripheral blood mononuclear cells (PBMCs), as in vitro model of sepsis. The study found that beta2-AR agonists inhibited IL-18 and IL-12 production in monocytes, and that AR agonist activity was antagonized by the selective beta2-AR antagonist, butoxamine. The selective beta2-AR agonists salbutamol and terbutaline induced a similar inhibitory pattern of IL-18 and IL-12 production. IL-12 production induced by LPS was inhibited by anti-IL-18 Ab, but IL-18 production by LPS was not inhibited by anti-IL-12 Ab, showing that LPS induced IL-18 production without IL-12 production. Therefore, the stimulation of beta2-AR might be beneficial in the treatment of sepsis through inhibiting LPS-elicited IL-18.

Ciprofloxacin, a fluorinated 4-quinolone, is useful for the clinical treatment of infections due to its antibacterial properties and also modulates the immune response of monocytes isolated from human peripheral blood mononuclear cells. In the present study, we found that ciprofloxacin induced the production of prostaglandin E(2) in monocytes in a concentration-dependent manner regardless of the presence of interleukin-18 by enhancing the expression of cyclooxygenase-2 protein and that this in turn led to the elevation of intercellular cyclic AMP in monocytes via the stimulation of prostaglandin receptors. The prostaglandin E(2) and cyclic AMP production increased by ciprofloxacin was inhibited by indomethacin, a nonselective cyclooxygenase-2 inhibitor, and NS398, a selective cyclooxygenase-2 inhibitor. In addition, ciprofloxacin suppressed the interleukin-18-induced production of tumor necrosis factor alpha, gamma interferon, and interleukin-12 in peripheral blood mononuclear cells by inhibiting the expression of intercellular adhesion molecule 1, B7.1, B7.2, and CD40 on monocytes, and this effect could be reversed by the addition of indomethacin or NS398. These results indicate that ciprofloxacin exerts immunomodulatory activity via the production of prostaglandin E(2) and imply therapeutic potential of ciprofloxacin for the treatment of systemic inflammatory responses initiated by interleukin-18.

The purpose of this present study was to explore the therapeutic potential of prostaglandins E1 and E2 on the systemic inflammatory response evoked by endotoxin. Since interleukin-18, a monocyte-derived cytokine, is increased during sepsis, decreasing the production of interleukin-18 is important in treating this condition. Prostaglandin E1 and E2 inhibited interleukin-18 production in human monocytes treated with lipopolysaccharide and prostanoid IP-, EP2- and EP4-receptor agonists mimicked the effects of prostaglandins E1 and E2. Therefore, prostanoid IP, EP2- and EP4-receptors might be involved in the decrease in interleukin-18 production during sepsis.

The effect of prostaglandins E1 and E2 on the 1 ng/ml lipopolysaccharide-induced expression of intercellular adhesion molecule (ICAM)-1, B7.1, B7.2, CD40 and CD40 ligand (CD40L) on monocytes was examined. Prostaglandin E1 suppressed B7.1 and CD40 expression, but prostaglandin E2 did not effect on any type of adhesion molecule expression. Both prostaglandins inhibited tumor necrosis factor (TNF)-alpha production and T-cell proliferation of lipopolysaccharide-treated human peripheral blood mononuclear cells (PBMC). Among prostaglandin E1 receptors (IP/EP1/EP2/EP3/EP4) agonists, ONO-1301, a prostanoid IP-receptor agonist, prevented B7.1 and CD40 expression. ONO-AE1-259-01 a prostanoid EP2-receptor agonist, ONO-AE1-329, a prostanoid EP4-receptor agonist, and ONO-1301 inhibited TNF-alpha production and T-cell proliferation. Moreover, anti-B7.1 and anti-CD40 Abs prevented lipopolysaccharide-induced TNF-alpha production and T-cell proliferation. Therefore, the effect of prostaglandin E1 on TNF-alpha production and T-cell proliferation might depend on the inhibition of B7.1 and CD40 expression, but that of prostaglandin E2 might be independent of adhesion molecules expression. In conclusion, the mechanism responsible for the effect of prostaglandin E1 on lipopolysaccharide-induced responses is distinct from that of prostaglandin E2.

Prostaglandin E1 (PGE1) has therapeutic value for transplantations due to its microvascular activity. Interleukin (IL)-18, which is elevated in plasma during the acute rejection after organ transplantation, elicits the expression of intercellular adhesion molecule (ICAM)-1, B7.1, B7.2, CD40, and CD40 ligand (CD40L) on monocytes as well as the production of interferon (IFN)-gamma and IL-12 and proliferation of T-cells during the human mixed lymphocyte reaction (MLR) in an in vitro model of acute rejection. In contrast, PGE1 inhibits all the adhesion molecule expression, cytokine production and T-cell proliferation in the presence of IL-18. The effects of PGE1 depend on stimulation of the IP/EP2/EP4-receptor, and thus, PGE1 might have therapeutic potential for treating acute rejection due to its immune regulatory effect.

The interleukin (IL)-18 level in plasma is elevated during the acute rejection after organ transplantation. IL-18 elicits adhesion molecule expression as well as interferon-gamma/IL-12 production and T-cell proliferation in the human mixed lymphocyte reaction, an in vitro model of acute rejection. We examined whether antibodies (Abs) against intercellular adhesion molecule (ICAM)-1, B7, CD40, and CD40, ligand (CD40L) affect the cytokine production and T-cell proliferation. Anti-ICAM-1 and B7 Abs suppressed the cytokine production, while all Abs inhibited T-cell proliferation. ICAM-1 and B7 as well as CD40 may play different roles in the acute rejection.

Proteinase-activated receptor-2 (PAR-2) has been demonstrated to be highly expressed in the gastrointestinal tract. In the present minireview, we summarize the effects of PAR-1 and PAR-2 stimulation using their activating peptides and agonist proteinases on the calcium signaling and the cell proliferation in DLD-1 cell, a human colon cancer cell line. PAR-2 but not PAR-1 stimulation induced the enhancement of cell proliferation, whereas both PAR-1 and PAR-2 stimulation induced the transient increase in [Ca(2+)](i). PAR-2 stimulation induced the phosphorylation of MEK1/2 and ERK1/2, but PAR-1 stimulation did not. The inhibition of MEK1/2 by PD98059 completely abolished the proliferative response to PAR-2 stimulation. Thus, MEK-ERK activation plays major role in the PAR-2-mediated proliferative response. The coupling of PARs to calcium signaling and MEK-ERK activation may be independent, and varied dependent on cell types.

The activation of T cells plays a role in antitumor response. Monocytes activate T cells by inducing the cell-to-cell interaction that involves the engagement of adhesion molecules with their ligands, and the production of IL-18. The authors examined the effect of the quinazoline-based alpha1-adrenergic receptor antagonists bunazosin, doxazosin, prazosin, and terazosin on the expression of adhesion molecules such as ICAM-1, B7.1, B7.2, CD40, and CD40L on monocytes isolated from human peripheral blood mononuclear cells. Doxazosin, prazosin, and terazosin induced the expression of ICAM-1 and CD40 but had no effect on the expression of B7.1, B7.2, and CD40L. Moreover, IL-18 was detected in the medium of incubated monocytes treated with doxazosin, prazosin, and terazosin. Bunazosin did not affect adhesion molecule expression and IL-18 production, suggesting that the chemical structure of quinazoline might not be related to the effect of doxazosin, prazosin, and terazosin. Although caspase-1 inhibitor completely abolished the production of IL-18, anti-IL-18 mAb and caspase-1 inhibitor partially inhibited the increase in ICAM-1 and CD40 expression induced by doxazosin, prazosin, and terazosin. Doxazosin, prazosin, and terazosin can induce monocyte activation with a specific pattern of expression of adhesion molecules and IL-18 production, and this may lead to T-cell activation through the cell-to-cell interaction. The activation of T cells induced by the increase of the expression of ICAM-1 and CD40 and the production of IL-18 may be involved in the anti-cancer effects of doxazosin, prazosin, and terazosin.

Endogenous catecholamine, epinephrine and norepinephrine, and isoproterenol concentration-dependently induced the production of interleukin (IL)-18, tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma, and inhibited that of IL-10 in human peripheral blood mononuclear cells (PBMC). All responses by these stimulations were antagonized by the selective beta 2-adrenergic receptor (AR) antagonist, butoxamine, but not by alpha 1-, alpha 2- and beta 1-AR antagonists. The selective beta 2-AR agonists, salbutamol and terbutaline, induced a similar pattern of cytokine production, indicating that the effect of these AR agonists on cytokine production was through beta 2-AR stimulation. Anti-IL-18 Ab or caspase-1 inhibitor prevented all increase/decrease effects, suggesting that IL-18 might affect the production of all other cytokines. While endogenous IL-18 produced by salbutamol and terbutaline reached a sufficient concentration to induce IL-12 production, these beta 2-AR agonists did not induce the production of IL-12 at all. Epinephrine/norepinephrine/isoproterenol/beta 2-AR agonists increased the production of IL-18 in monocytes, but had no effect on IL-12, TNF-alpha, IFN-gamma and IL-10 production. The lack of beta 2-AR-induced effect on IL-12 production was due to a beta 2-AR-induced inhibition of an IL-18-elicited upregulation of both CD40 and CD40 ligand (CD40L/CD154) expressions on monocytes. The sympathetic innervating lymphoid organs may be under the control of beta2-AR stimulation, maintaining the basal cytokine environment in the tissues.

Unlabelled: Radon therapy uses radon (222Rn) gas, which mainly emits alpha-rays and induces a small amount of active oxygen in the body. We first examined the temporal changes in antioxidants, immune, vasoactive, and pain-associated substances in human blood by therapy to elucidate the mechanism of osteoarthritis in which radon therapy is used as a treatment. Results showed that radon inhalation enhanced the antioxidation and immune function, and the findings suggest that radon therapy contributes to the prevention of osteoarthritis related to peroxidation reactions and immune depression. Moreover, the changes in vasoactive and pain-associated substances indicated increases in tissue perfusion brought about by radon therapy, suggesting that radon inhalation plays a role in alleviating pain., Perspective: The findings suggest that an appropriate amount of active oxygen is produced in the body after radon inhalation, and this contributes to the alleviation of the symptoms of active oxygen diseases such as osteoarthritis.

Background: The plasma interleukin (IL)-18 level is elevated in acute rejection after organ transplantation. Although beta2-adrenergic receptor (AR) agonists suppress the rejection of organ and tissue transplants, little is known about their action mechanisms. We examined the effects of endogenous catecholamines and beta2-AR agonists on the expression of intercellular adhesion molecule (ICAM)-1, B7.1, B7.2, CD40, and CD40 ligand (CD40L) in human mixed lymphocyte reaction (MLR) and in an in vitro model of acute rejection in the presence or absence of IL-18., Methods: ICAM-1, B7.1 B7.2, CD40, and CD40L expression on monocytes was measured by flow cytometry, and the production of interferon (IFN)-gamma and IL-12 was determined by enzyme-linked immunosorbent assay. Lymphocytes proliferation in MLR was measured by [3H]-thymidine uptake. The relevant AR subtypes were characterized using subtype-selective agonists and antagonists., Results: beta2-AR agonists inhibited the expression of ICAM-1 and CD40 during MLR in the absence of IL-18. Among IL-18-induced expression of ICAM-1, B7.1, B7.2, CD40, and CD40L, beta2-AR agonists inhibited ICAM-1 and CD40 expression. beta2-AR agonists prevented the production of IFN-gamma and IL-12 in the presence of IL-18 but had no effect in the absence of IL-18. beta2-AR agonists inhibited lymphocyte proliferation in IL-18-treated MLR., Conclusions: We found that beta2-AR agonists strongly inhibited the expression of ICAM-1 and CD40, irrespective of the presence or absence of IL-18, which is different from that of histamine and prostaglandin E2.

In the present study, we examined the effects of prostaglandin E1 (PGE1) on the expression of intercellular adhesion molecule (ICAM)-1, B7.1, B7.2, CD40, and CD40 ligand (CD40L) on peripheral blood mononuclear cells (PBMC) using fluorescence-activated cell sorting analysis as well as its effects on cytokine production using enzyme-linked immunosorbent assay. Whereas no inhibitor of spontaneous expression of adhesion molecules was reported, we found that PGE1 inhibited spontaneous ICAM-1, B7.2, and CD40 expression on monocytes in a concentration-dependent manner but had no effect on the expression of B7.1 and CD40L. Although interleukin (IL)-18 induced the expression of ICAM-1, B7.2, CD40, and CD40L, PGE1 prevented IL-18-induced expression of ICAM-1, B7.2, and CD40. We examined the involvement of five subtypes of PGE1 receptors (IP, EP1, EP2, EP3, and EP4) in the effect of PGE1 on the expression of these adhesion molecules using subtype-specific agonists. Among EP receptor agonists, EP2 and EP4 receptor agonists inhibited IL-18-elicited ICAM-1, B7.2, and CD40 expression. ONO-1301 (IP receptor agonist) prevented the expression of ICAM-1, B7.2, and CD40 regardless of the presence of IL-18 with the same potency as PGE1. The effect of a combination of ONO-1301 and 11-deoxy (D)-PGE1 (EP2/EP4 receptor agonist) on ICAM-1, B7.2, and CD40 expression mimicked that of PGE1. Moreover, PGE1 inhibited the production of IL-12 and interferon-gamma in PBMC in the presence and absence of IL-18, whereas PGE1 induced IL-10 production. In conclusion, IP receptor and EP2/EP4 receptor play an important role in the action of PGE1 on the expression of adhesion molecules on monocytes and cytokine production.

Lipopolysaccharide (LPS) is recognized as a key molecule in the pathogenesis of Gram negative sepsis and septic shock. In the present study, we demonstrate that LPS (1-1000 pg/ml) concentration dependently up-regulated the expression of intercellular adhesion molecule (ICAM)-1, B7.1, and B7.2 on human monocytes using fluorescence-activated cell sorting analysis, and that tumor necrosis factor (TNF)-alpha production induced by LPS in peripheral blood mononuclear cells (PBMCs) was inhibited by the addition of antibodies against these adhesion molecules, suggesting the dependence of TNF-alpha production on cell-cell interaction through these adhesion molecules. Moreover, we found that histamine (10(-7)-10(-4) M) concentration dependently inhibited the expression of ICAM-1 and B7.1, but not B7.2 on monocytes induced by LPS. Histamine also inhibited the responses of TNF-alpha production induced by LPS. The modulatory effects of histamine on ICAM-1 and B7.1 expression and TNF-alpha production were all concentration dependently antagonized by famotidine but not by d-chlorpheniramine and thioperamide, and were mimicked by selective H2-receptor agonists but not by H1-, H3-, and H4-receptor agonists, indicating the involvement of H2-receptors in the histamine action. Dibutyryl cAMP down-regulated ICAM-1 and B7.1 expression on monocytes stimulated by LPS, suggesting the mediation by the cyclic adenosine monophosphate-protein kinase A pathway of H2-receptor activation. These results as a whole indicated that histamine via H2-receptor inhibited the LPS-induced TNF-alpha production through the regulation of ICAM-1 and B7.1 expression, leading to the reduction of innate immune response stimulated by LPS.

beta-Adrenergic receptor (AR) agonists have been demonstrated to modulate the production of inflammatory mediators. Recent studies implied that beta 2-AR agonists might be useful for chronic inflammatory diseases caused by interleukin (IL)-18. In the present study, we found that norepinephrine, epinephrine, or isoproterenol down-regulated IL-18 (100 ng/ml)-induced intercellular adhesion molecule (ICAM)-1 expression on monocytes in a dose-dependent manner (10(-8)-10(-4) M), but did not effect B7.1 and B7.2 expression after 24-h incubation. The modulatory effect of these catecholamines on ICAM-1 expression was antagonized by beta 2-AR antagonist, but not by alpha 1-, alpha 2-, or beta 1-AR antagonist. beta 2-AR-selective agonists salbutanol and terbutaline down-regulated IL-18-induced ICAM-1 expression on monocytes, but alpha 1-, alpha 2-, or beta1-AR agonist had no effect. In the same manner, salbutanol and terbutaline as well as norepinephrine, epinephrine, and isoproterenol regulated the IL-18-induced cytokine production, including IL-12, tumor necrosis factor-alpha or interferon-gamma through the stimulation of beta 2-AR. Together with the previous finding that ICAM-1/lymphocyte function-associated antigen-1 interaction plays a crucial role in the IL-18-initiated cytokine network, the present study strongly suggested that the stimulation of beta 2-AR inhibited the IL-18-activated cytokine cascade through the inhibitory effect on ICAM-1 expression, contributing to finding a new method for clinical treatment.

Costimulatory molecules play important roles in immune responses. In the present study we investigated the effects of PGE(2) on the expression of ICAM-1, B7.1, and B7.2 on monocytes in IL-18-stimulated PBMC using FACS analysis. Addition of PGE(2) to PBMC inhibited ICAM-1 and B7.2 expression elicited by IL-18 in a concentration-dependent manner. We examined the involvement of four subtypes of PGE(2) receptors, EP1, EP2, EP3, and EP4, in the modulatory effect of PGE(2) on ICAM-1 and B7.2 expression elicited by IL-18, using subtype-specific agonists. ONO-AE1-259-01 (EP2R agonist) inhibited IL-18-elicited ICAM-1 and B7.2 expression in a concentration-dependent manner with a potency slightly less than that of PGE(2), while ONO-AE1-329 (EP4R agonist) was much less potent than PGE(2). The EP2/EP4R agonist 11-deoxy-PGE(1) mimicked the effect of PGE(2) with the same potency. ONO-D1-004 (EP1R agonist) and ONO-AE-248 (EP3R agonist) showed no effect on IL-18-elicited ICAM-1 or B7.2 expression. These results indicated that EP2 and EP4Rs were involved in the action of PGE(2). Dibutyryl cAMP and forskolin down-regulated ICAM-1 and B7.2 expression in IL-18-stimulated monocytes. As EP2 and EP4Rs are coupled to adenylate cyclase, we suggest that PGE(2) down-regulates IL-18-induced ICAM-1 and B7.2 expression in monocytes via EP2 and EP4Rs by cAMP-dependent signaling pathways. The fact that anti-B7.2 as well as anti-ICAM-1 Ab inhibited IL-18-induced cytokine production implies that PGE(2) may modulate the immune response through regulation of the expression of particular adhesion molecules on monocytes via EP2 and EP4Rs.

IL-18 (0-100 ng/ml) specifically upregulated ICAM-1 expression on monocytes in human PBMC as demonstrated in our previous study. In the present study, we examined whether the synergistic upregulation of ICAM-1 occurred after the stimulation with the combination of IL-18 and IL-12 and whether the synergistic production of IFN-gamma was dependent on the interaction between ICAM-1 on monocytes and LFA-1 on NK/T cells. The effect of IL-12 on ICAM-1 expression on monocytes was marginal even at the highest concentration (100 ng/ml). However, in the presence of IL-12 (100 ng/ml), the expression of ICAM-1 induced by IL-18 was significantly enhanced as compared with that obtained by IL-18 alone. In addition to the expression of ICAM-1 on monocytes, IFN-gamma production was synergistically stimulated by IL-18 and IL-12. Anti-ICAM-1 and anti-LFA-1 Abs exhibited significant inhibitory effect on enhanced production of IFN-gamma by the combination of two cytokines, in particular, anti-ICAM-1 showing the complete inhibition. These results as a whole indicated that synergistic effect of IL-18 and IL-12 on IFN-gamma production in human PBMC is ascribed to the synergism of the effect of two cytokines on ICAM-1 expression on monocytes and that the subsequent ICAM-1/LFA-1 interaction plays an important role in the enhanced production of IFN-gamma.

The catalase activities in blood and organs of the acatalasemic (C3H/AnLCsbCsb) mouse of the C3H strain are lower than those of the normal (C3H/AnLCsaCsa) mouse. We conducted a study to examine changes in the activities of antioxidant enzymes, such as catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPX), the total gluathione content, and the lipid peroxide level in the brain, which is more sensitive to oxidative stress than other organs, at 3, 6, or 24 hr following X-ray irradiation at doses of 0.25, 0.5, or 5.0 Gy to the acatalasemic and the normal mice. No significant change in the lipid peroxide level in the acatalasemic mouse brain was seen under non-irradiation conditions. However, the acatalasemic mouse brain was more damaged than the normal mouse brain by excessive oxygen stress, such as a high-dose (5.0 Gy) X-ray. On the other hand, we found that, unlike 5.0 Gy X-ray, a relatively low-dose (0.5 Gy) irradiation specifically increased the activities of both catalase and GPX in the acatalasemic mouse brain making the activities closer to those in the normal mouse brain. These findings may indicate that the free radical reaction induced by the lack of catalase is more properly neutralized by low dose irradiation.

The increase in lipid peroxide levels in mice brain following Fe3+ administration was about 50% of that when 1-methyl-4-phenyl 1,2,3,6-tetrahydropyridine (MPTP) was administered. This may be due to excessive oxidation by Fe3+, and was supported by the decrease in activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX), Na+,K(+)-ATPase activity and membrane fluidity after Fe3+ administration. Relatively low-dose X-ray irradiation (0.5 Gy) inhibited lipid peroxidation associated with Fe3+ administration and restored the decreased activities of the above antioxidant enzymes and Na+,K(+)-ATPase, and membrane fluidity to the levels in the non-Fe(3+)-administered group. In the purine metabolism system, uric acid decreased after Fe3+ administration, which may be due to transient impairment of the system for production of uric acid from xanthine by excessive oxidation by Fe3+. However, 0.5 Gy irradiation inhibited this decrease in uric acid, increasing its level to that in the non Fe(3+)-administrated group. This may be due to factors such as rapid recovery of the activities of the above antioxidant enzymes and Na+,K(+)-ATPase, and membrane fluidity after 0.5 Gy irradiation. In addition, since no changes were observed in xanthine and uric acid, increased inosine and hypoxanthine may have advanced to a salvage pathway leading to not xanthine but inosine 5'-monophosphate (IMP).