Home About us Contact
|
Home About us Contact | ||
|
|
||
Peritoneal Macrophages (peritoneal + macrophage)
Kinds of Peritoneal Macrophages Selected AbstractsORIGINAL ARTICLE: Leptin on Peritoneal Macrophages of Patients with EndometriosisAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 3 2010Meng-Hsing Wu Citation Wu M-H, Huang M-F, Chang F-M, Tsai S-J. Leptin on peritoneal macrophages of patients with endometriosis. Am J Reprod Immunol 2010; 63: 214,221 Problem, The expression of cyclooxygenase (COX)-2 is considered as a marker of macrophage activation and has been implicated in the development of endometriosis. Leptin is an immunomodulator, which may also affect the development of endometriosis. However, how leptin contributes to these pathological processes has not been completely understood. The aim of this study was to investigate the effects of leptin on peritoneal macrophages and its relationship with endometriosis. Methods of study, Peritoneal fluid from 60 women of reproductive age was obtained while they underwent laparoscopy. Forty patients had endometriosis and 20 patients did not have endometriosis. The concentration of leptin in the peritoneal fluid and prostaglandin F2, levels was measured by ELISA, and the other protein expression using Western blot when peritoneal macrophages were stimulated with leptin. Results, Concentration of leptin in peritoneal fluid was increased in patients with endometriosis compared with disease-free normal control. Functional leptin receptor was present in peritoneal macrophages. Treatment of peritoneal macrophages with leptin induced COX-2 expression. Production of prostaglandin F2, by peritoneal macrophages was increased after leptin stimulation in women with endometriosis. Conclusion, Elevated concentration of leptin in peritoneal fluid may contribute to the pathological process of endometriosis through activation of peritoneal macrophages. [source] Hypoxia is an inducer of vasodilator agents in peritoneal macrophages of cirrhotic patientsHEPATOLOGY, Issue 5 2002Pilar Cejudo-Martín The aim of the investigation was to assess whether hypoxia induces the production of endogenous vasoactive peptides in macrophages of cirrhotic patients with ascites because low tissue oxygenation is a relatively frequent event in these patients. Peritoneal macrophages were isolated from ascites, seeded on well plates, and cultured at different times under hypoxic (5% O2) or normoxic conditions (21% O2). Then, accumulation of vasoactive peptides sensitive to hypoxia including endothelin-1 (ET-1), vascular endothelial growth factor (VEGF), and adrenomedullin (ADM) was measured. Only VEGF and ADM were constitutively secreted, and hypoxia further stimulated the release of these vasodilator peptides. In concordance, increased messenger RNA (mRNA) levels of VEGF and ADM were found at culturing macrophages in hypoxia. This characteristic response was not observed in circulating monocytes of either cirrhotic patients or healthy subjects. Next the expression of the transcription factor, hypoxia inducible factor 1 (HIF-1), was analyzed. Expression of HIF-1, and HIF-1, messengers and HIF-1, protein subunit remained unchanged regardless of O2 tension, whereas HIF-1, protein subunit was overexpressed under hypoxic conditions. Moreover, conditioned medium from macrophages cultured under hypoxic conditions promoted a larger nitric oxide (NO) release in endothelial cells than that of normoxic macrophages. In conclusion, these data indicate that hypoxia induces the synthesis of VEGF and ADM in macrophages of cirrhotic patients, likely through HIF-1,enhanced transcriptional activity. These data suggest that a local reduction in O2 tension could enhance the synthesis of macrophage-derived vasodilators, thus aggravating the circulatory disturbance of these patients. [source] NTPDase1 governs P2X7 -dependent functions in murine macrophagesEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 5 2010Sébastien A. Lévesque Abstract P2X7 receptor is an adenosine triphosphate (ATP)-gated ion channel within the multiprotein inflammasome complex. Until now, little is known about regulation of P2X7 effector functions in macrophages. In this study, we show that nucleoside triphosphate diphosphohydrolase 1 (NTPDase1)/CD39 is the dominant ectonucleotidase expressed by murine peritoneal macrophages and that it regulates P2X7 -dependent responses in these cells. Macrophages isolated from NTPDase1-null mice (Entpd1,/,) were devoid of all ADPase and most ATPase activities when compared with WT macrophages (Entpd1+/+). Entpd1,/, macrophages exposed to millimolar concentrations of ATP were more susceptible to cell death, released more IL-1, and IL-18 after TLR2 or TLR4 priming, and incorporated the fluorescent dye Yo-Pro-1 more efficiently (suggestive of increased pore formation) than Entpd1+/+ cells. Consistent with these observations, NTPDase1 regulated P2X7 -associated IL-1, release after synthesis, and this process occurred independently of, and prior to, cytokine maturation by caspase-1. NTPDase1 also inhibited IL-1, release in vivo in the air pouch inflammatory model. Exudates of LPS-injected Entpd1,/, mice had significantly higher IL-1, levels when compared with Entpd1+/+ mice. Altogether, our studies suggest that NTPDase1/CD39 plays a key role in the control of P2X7 -dependent macrophage responses. [source] The chemokine receptor CCR6 is an important component of the innate immune responseEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 9 2007Haitao Wen Abstract In our initial studies we found that naďve CCR6-deficient (CCR6,/,) C57BL/6 mice possessed significantly lower number of both F4/80+ macrophages and dendritic cells (DC), but higher number of B cells in the peritoneal cavity, as compared to naďve wild type (WT) controls. Furthermore, peritoneal macrophages isolated from CCR6,/, mice expressed significantly lower levels of inflammatory cytokines and nitric oxide following lipopolysaccharide (LPS)stimulation, as compared to WT macrophages. In a severe experimental peritonitis model induced by cecal ligation and puncture (CLP), CCR6,/, mice were protected when compared with WT controls. At 24,h following the induction of peritonitis, CCR6,/, mice exhibited significantly lower levels of inflammatory cytokines/chemokines in both the peritoneal cavity and blood. Interestingly, DC recruitment into the peritoneal cavity was impaired in CCR6,/, mice during the evolution of CLP-induced peritonitis. Peritoneal macrophages isolated from surviving CCR6,/, mice 3,days after CLP-induced peritonitis exhibited an enhanced LPS response compared with similarly treated WT peritoneal macrophages. These data illustrate that CCR6 deficiency alters the innate response via attenuating the hyperactive local and systemic inflammatory response during CLP-induced peritonitis. [source] Specific ICAM-3 grabbing nonintegrin-related 1 (SIGNR1) expressed by marginal zone macrophages is essential for defense against pulmonary Streptococcuspneumoniae infectionEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2005Estella Abstract The dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN) homolog, SIGN-related 1 (SIGNR1) is a pathogen receptor expressed by splenic marginal zone and peritoneal macrophages, and is essential for clearance of Streptococcus pneumoniae by phagocytosis after intraperitoneal infection. Here, we identified an important in vivo function for SIGNR1 in S.pneumonia infection induced via its natural entrance route. Upon intranasal infection with S. pneumoniae, SIGNR1-deficient mice did not clear bacteria from lung and blood, and displayed severely enhanced inflammatory parameters compared to the wild-type mice. However, SIGNR1 is not expressed by alveolar macrophages, suggesting that another mechanism than a decrease in phagocytosis is responsible for this difference. Natural anti-phosphorylcholine IgM produced by marginal zone B cells is essential for protection against infection with S. pneumoniae. Strikingly, during infection, SIGNR1-deficient mice failed to produce a rapid anti-phosphorylcholine IgM response. Marginal zone macrophages have been suggested to capture antigens for presentation to marginal zone B cells. We demonstrate that marginal zone macrophages from SIGNR1-deficient mice in contrast to wild-type mice are not able to capture pneumococci from blood, suggesting that SIGNR1 on marginal zone macrophages captures S. pneumoniae for antigen presentation to and activation of marginal zone B cells, resulting in an anti-phosphorylcholine IgM response. [source] Interferon-, and lipopolysaccharide regulate the expression of Nramp2 and increase the uptake of iron from low relative molecular mass complexes by macrophagesFEBS JOURNAL, Issue 22 2000S. L. Wardrop The natural resistance associated macrophage protein 2 (Nramp2) is a transporter that is involved in iron (Fe) uptake from transferrin (Tf) and low molecular mass Fe complexes. Here we describe the effect of the inflammatory mediators interferon-, (IFN-,) and lipopolysaccharide (LPS) on the expression of Nramp2 mRNA and Fe uptake by cells of the macrophage lineage. After incubation of the RAW264.7 macrophage cell line with LPS there was a sevenfold increase in the expression of the 2.3 kb Nramp2 mRNA transcript when compared with the control, but little effect on the Nramp2 3.1 kb transcript. These results indicate differential regulation of the two transcripts. Treatment with LPS resulted in an increase in 59Fe uptake from 59Fe,nitrilotriacetic acid, while transferrin receptor (TfR) mRNA levels and 59Fe uptake from 59Fe,Tf were decreased. Paradoxically, at the same time, an increase in iron regulatory protein (IRP)1 RNA-binding activity was observed. Incubation with IFN-, (50 U·mL,1) resulted in a marked decrease in TfR mRNA levels but had no effect on Nramp2 mRNA expression. Exposure of RAW264.7 cells to both IFN-, and LPS resulted in a fourfold increase in the Nramp2 2.3-kb transcript and a four to fivefold decrease in the 3.1-kb transcript when compared with the control. Furthermore, there was a decrease in TfR mRNA levels despite an increase in IRP1 RNA-binding activity and a marked increase in inducible nitric oxide synthase mRNA expression. Hence, TfR and Nramp2 mRNA expression did not appear to be regulated in a concerted manner. Similar responses to those found above for RAW264.7 cells were also observed in the J774 macrophage cell line and also for primary cultures of mouse peritoneal macrophages. These results are of interest as the TfR and Nramp2 are thought to act together during Fe uptake from Tf. This is the first report to demonstrate regulation of the Nramp2 mRNA transcripts by inflammatory mediators. [source] Increased tumour necrosis factor-, production, higher mannose receptor activity and ability to kill Candida by concanavalin-A-activated macrophagesFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2010Thais Herrero Geraldino Abstract In a previous study, our group verified that mice pretreated with concanavalin-A (Con-A) produced more tumour necrosis factor (TNF)-, and presented greater Candida clearance from the peritoneal cavity, liver and spleen, which yielded a higher survival rate than control animals. In this work, the hypothesis that macrophages were of crucial importance in overcoming the infection was tested. Thus, peritoneal macrophages from mice pretreated for 3 days with Con-A or phosphate-buffered saline (PBS) were coincubated with CR1, CR15 and 577 isolates of Candida albicans for 0.5, 1 and 2 h. The ability of Con-activated macrophages to produce TNF-,, ingest via mannose receptors and kill all the isolates was significantly greater compared with PBS-treated macrophages, and activated macrophages exhibited a lower incidence of apoptosis, verified by binding to annexin V-fluorescein isothiocyanate. The transition of yeast cells to filamentous forms during coincubation for 2 h with control macrophages was about 73,80%, whereas in the presence of Con-A-activated macrophages, it was 35,40%. Our results suggest that a greater clearance of C. albicans infection through treatment with Con-A is probably due to the activation of macrophages, which produce more TNF-,, express more mannose receptors and are better endowed to kill ingested C. albicans. [source] Various cells of the immune system and intestine differ in their capacity to reduce hexavalent chromiumFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2003Richa Shrivastava Abstract The cells of the immune system form a strong line of defence against foreign substances. The present study was undertaken to investigate the capacity of different cells of Wistar rats to reduce potentially carcinogenic hexavalent chromium (Cr-VI) into less toxic trivalent chromium in vitro. 5×106 cells were incubated with 10 or 25 ,g ml,1 of Cr (VI) in the form of K2Cr2O7 at 37°C in the presence of 5% CO2 in air. At various time periods the remaining amount of Cr (VI) was measured and the percentage of Cr (VI) reduced was calculated. Among the single cell suspensions from the splenic cells a peak reduction of 55% was observed with the total spleen cells, 40% with the B-lymphocyte-enriched subpopulation, 10% with T-lymphocytes and 24% with the macrophages. The reduction by splenic and peritoneal macrophages was similar. Total thymocytes reduced 54% of the Cr (VI). Since the most common route of entry of chromium is through drinking water and food, intestinal cells were also investigated. Among the intestinal cells the maximum reduction of 100% (of 10 ,g ml,1) was observed with the upper villus cells and 72% with the middle villus cells while reduction was the least (4%) with the crypt cells. The reduction in the intestinal loop in situ was 100%. The time taken by each cell type for the peak reduction to Cr (VI) was markedly different. The findings thus show that the capacity of different cells in the body differs vastly in their capacity and time taken to reduce hexavalent chromium. The most efficient handling of Cr (VI) by the intestine, due to the presence of a variety of cells and bacteria, protects the body from its adverse effects. [source] Immunobiological activities of a chemically synthesized lipid A of Porphyromonas gingivalisFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 4 2000Tomohiko Ogawa Abstract A synthetic lipid A of Porphyromonas gingivalis strain 381 (compound PG-381), which is similar to its natural lipid A, demonstrated no or very low endotoxic activities as compared to Escherichia coli -type synthetic lipid A (compound 506). On the other hand, compound PG-381 had stronger hemagglutinating activities on rabbit erythrocytes than compound 506. Compound PG-381 also induced mitogenic responses in spleen cells from lipopolysaccharide (LPS)-hyporesponsive C3H/HeJ mice, as well as LPS-responsive C3H/HeN mice. The addition of polymyxin B resulted in the inhibition of mitogenic activities, however, compound 506 did not show these capacities. Additionally, compound PG-381 showed a lower level of activity in inducing cytokine production in peritoneal macrophages and gingival fibroblasts from C3H/HeN mice, but not C3H/HeJ mice, in comparison to compound 506. Thus, this study demonstrates that the chemical synthesis of lipid A, mimicking the natural lipid A portion of LPS from P. gingivalis, confirms its low endotoxic potency and immunobiological activity. [source] Formation of cholesterol-enriched structures by aberrant intracellular accumulation of ATP-binding cassette transporter A1GENES TO CELLS, Issue 8 2008Arowu R. Tanaka ATP-binding cassette transporter A1 (ABCA1) is a key transporter associated with excess cellular lipid efflux. Here, we report that in HEK293 cells ABCA1 functions in intracellular compartments along the endocytic pathway. Inhibition of ABCA1-GFP degradation with proteasome inhibitors induced the internalization of ABCA1 and the formation of intracellular round-shaped structures, designated "A1 bodies". Importantly, cholesterol was selectively accumulated in A1 bodies, and this depended on the cholesterol efflux activity of ABCA1. Treatment with either lactacystin or acetylated LDL, which reduces proteasome activity, resulted in internalization of ABCA1 in mouse peritoneal macrophages. By performing array analysis on macrophages treated with these reagents, we identified Rab4 as a key protein involved in the internalization and aberrant accumulation of ABCA1 in HEK cells. Treatment of the cells with proteasome inhibitors inhibited the degradation of Rab4, and Rab4 over-expression induced the formation of small A1 bodies. Furthermore, A1 bodies formation was substantially inhibited by silencing of the endogenous Rab4 gene. Taken together, our findings suggest that the endocytic ABCA1 possesses cholesterol efflux activity, and thus the cellular control of post-endocytic sorting, retention or recycling of functional ABCA1 in the endocytic vesicles, which is in part regulated by Rab4, is important for cholesterol metabolism in living cells. [source] Hypoxia is an inducer of vasodilator agents in peritoneal macrophages of cirrhotic patientsHEPATOLOGY, Issue 5 2002Pilar Cejudo-Martín The aim of the investigation was to assess whether hypoxia induces the production of endogenous vasoactive peptides in macrophages of cirrhotic patients with ascites because low tissue oxygenation is a relatively frequent event in these patients. Peritoneal macrophages were isolated from ascites, seeded on well plates, and cultured at different times under hypoxic (5% O2) or normoxic conditions (21% O2). Then, accumulation of vasoactive peptides sensitive to hypoxia including endothelin-1 (ET-1), vascular endothelial growth factor (VEGF), and adrenomedullin (ADM) was measured. Only VEGF and ADM were constitutively secreted, and hypoxia further stimulated the release of these vasodilator peptides. In concordance, increased messenger RNA (mRNA) levels of VEGF and ADM were found at culturing macrophages in hypoxia. This characteristic response was not observed in circulating monocytes of either cirrhotic patients or healthy subjects. Next the expression of the transcription factor, hypoxia inducible factor 1 (HIF-1), was analyzed. Expression of HIF-1, and HIF-1, messengers and HIF-1, protein subunit remained unchanged regardless of O2 tension, whereas HIF-1, protein subunit was overexpressed under hypoxic conditions. Moreover, conditioned medium from macrophages cultured under hypoxic conditions promoted a larger nitric oxide (NO) release in endothelial cells than that of normoxic macrophages. In conclusion, these data indicate that hypoxia induces the synthesis of VEGF and ADM in macrophages of cirrhotic patients, likely through HIF-1,enhanced transcriptional activity. These data suggest that a local reduction in O2 tension could enhance the synthesis of macrophage-derived vasodilators, thus aggravating the circulatory disturbance of these patients. [source] Tumor necrosis factor-, augments lipopolysaccharide-induced suppressor of cytokine signalling 3 (SOCS-3) protein expression by preventing the degradationIMMUNOLOGY, Issue 1 2010Jargalsaikhan Dagvadorj Summary The regulatory role of tumour necrosis factor-, (TNF-,) on the expression of suppressor of cytokine signalling 3 (SOCS-3) in response to lipopolysaccharide (LPS) was examined using peritoneal macrophages from TNF-,-deficient mice. The LPS-induced SOCS-3 expression was markedly augmented in macrophages from wild-type mice whereas such augmentation was not seen in the cells from TNF-,-deficient mice. However, there was no significant difference in the level of SOCS-3 messenger RNA expression between macrophages from wild-type mice and those from TNF-,-deficient mice. The addition of exogenous TNF-, augmented the LPS-induced SOCS-3 expression in macrophages from TNF-,-deficient mice. The pulse chase analysis suggested augmented degradation of LPS-induced SOCS-3 protein in macrophages from TNF-,-deficient mice. Moreover, MG 132, a 26S proteasome inhibitor, sustained the LPS-induced SOCS-3 expression in those cells. The tyrosine phosphorylation of SOCS-3 was definitely induced in LPS-stimulated macrophages from TNF-,-deficient mice but not wild-type mice. A tyrosine phosphatase inhibitor enhanced the tyrosine phosphorylation of SOCS-3 in wild-type mice and accelerated the degradation. Therefore, it was suggested that TNF-, prevented the degradation of SOCS-3 protein via inhibition of the tyrosine phosphorylation in LPS-stimulated macrophages. [source] Bone morphogenetic protein-6 induces the expression of inducible nitric oxide synthase in macrophagesIMMUNOLOGY, Issue 1pt2 2009Seok J. Kwon Summary Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-, (TGF-,) superfamily. In the present study, we investigated the effect of BMPs on the production of inducible nitric oxide synthase (iNOS) in the murine macrophage cell line, RAW 264.7, and in mouse peritoneal macrophages. Among the BMPs, only BMP-6 induced iNOS expression in a time-dependent and dose-dependent manner in both cell types. Induction of iNOS was inhibited by both cycloheximide and actinomycin D, indicating that the induction of iNOS expression by BMP-6 requires new protein synthesis. Mechanistic studies revealed that the BMP-6-induced iNOS expression requires both Smads and nuclear factor-kappa B (NF-,B) signalling pathways. Furthermore, induction of interleukin-1, (IL-1,) was necessary for iNOS induction by BMP-6. These observations suggest that BMP-6 stimulates macrophages to produce iNOS through IL-1, via Smad and NF-,B signalling pathways and that BMP-6 may be an important regulator of macrophages. [source] Receptor-mediated phagocytosis of rat macrophages is regulated differentially for opsonized particles and non-opsonized particles containing ,-glucanIMMUNOLOGY, Issue 2 2001Jonathan S. Reichner Summary Experiments were conducted to test the hypothesis that opsonic and non-opsonic phagocytic capacities are differentially regulated by resting and wound-derived macrophages. Furthermore, the phagocytosis of non-opsonized zymosan and ,-glucan particles was quantified to determine whether cells differentially regulate non-opsonic lectinophagocytosis in accordance with the carbohydrate composition of the ligand. In that regard, wound macrophages exhibited profound differential regulation in lectinophagocytosis with a seven-fold increase in phagocytosis of ,-glucan particles following overnight culture but with a relatively modest increase in internalization of mannan-containing zymosan. Cultured peritoneal macrophages increased uptake of both particles similarly. Upon activation with interferon-,/lipopolysaccharide (IFN-,/LPS), wound macrophages selectively suppressed ,-glucan ingestion, while phagocytosis of zymosan particles was unaffected. Lectinophagocytosis was decreased in activated peritoneal macrophages regardless of particle composition and was due in part to a nitric oxide-dependent mechanism which was without a role in regulation of wound macrophage lectinophagocytosis. Overnight culture of wound macrophages suppressed their capacity for opsonic-dependent phagocytosis independently of activation, whereas suppression of phagocytosis by peritoneal macrophages was activation-dependent. Regulation of all three phagocytic pathways was achieved distinctly by peritoneal and wound-derived macrophages, with changes found in the percentage of resident peritoneal macrophages capable of phagocytosis, whereas the phagocytic capacity of wound macrophages was primarily affected by the number of particles ingested by individual cells. Taken together, these findings demonstrate that the differential regulation of phagocytic pathways encompasses the nature of the phagocytic particle, the site from which macrophages are obtained, their response to activating agents and the mechanism through which the cell population alters its phagocytic potential. [source] Adrenaline inhibits macrophage nitric oxide production through ,1 and ,2 adrenergic receptorsIMMUNOLOGY, Issue 3 2000L. B. Sigola Summary This study was conducted to investigate the role of the acute stress hormone adrenaline on macrophage nitric oxide (NO) production. Murine peritoneal macrophages were stimulated in vitro with lipopolysaccharide (LPS) in the absence or presence of adrenaline. Adrenaline inhibited the LPS-induced nitrite response in a dose-dependent manner. The suppressive effect of adrenaline on NO production was mediated via ,1 and ,2 adrenergic receptors since isoprenaline (a non-selective ,1 and ,2 agonist), dobutamine and salbutamol (selective ,1 and ,2 agonists, respectively) had similar effects on the NO response. In addition, the inhibitory effect of adrenaline on NO was abrogated by both propranolol (a non-specific , blocker) and atenolol (a specific ,1 inhibitor). In contrast to , receptor activation, the , adrenergic agonist phenylephrine had no effect on the LPS NO response, and furthermore, phentolamine (an , receptor antagonist) did not ameliorate adrenaline's inhibitory action. [source] The effect of mineral trioxide aggregate on phagocytic activity and production of reactive oxygen, nitrogen species and arginase activity by M1 and M2 macrophagesINTERNATIONAL ENDODONTIC JOURNAL, Issue 8 2007T. M. B. Rezende Abstract Aim, To assess the influence of co-culture with mineral trioxide aggregate (MTA) on phagocytosis and the production of reactive oxygen intermediates (ROI) and nitrogen (NO) species and the arginase activity by M1 and M2 peritoneal macrophages. Methodology, Cellular viability, adherence and phagocytosis of Saccharomyces boulardii were assayed in the presence of MTA. Macrophages were stimulated with zymosan for ROI assays and with Fusobacterium nucleatum and Peptostreptococcus anaerobius and IFN- , for NO production and arginase activity, when in contact with capillaries containing MTA. Data were analysed by T, anova, Kruskall,Wallis and Mann,Whitney tests. Results, M2 macrophages displayed greater cellular viability in polypropylene tubes, greater ability to ingest yeast and smaller production of ROI and higher arginase activity when compared with M1 macrophages. Both macrophages, M1 and M2, presented similar cell adherence and NO production. The addition of bacterial preparations to macrophages interfered with NO and arginase productions. MTA did not interfere with any of the parameters measured. Conclusions, Phagocytosis and the ability of the two macrophage subtypes to eliminate microbes were not affected by MTA. [source] Specificity of a new lipid mediator produced by testicular and peritoneal macrophages on steroidogenesisINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 5 2000Lukyanenko Macrophage-derived factor (MDF) is a lipophilic factor produced by rat testicular and peritoneal macrophages that maximally stimulates testosterone production by rat Leydig cells through a steroidogenic acute regulatory protein independent mechanism. The purpose of the present study was to determine whether MDF is also produced by human macrophages, and/or if it acts on human steroidogenic cells. We also studied the tissue-specific functions of MDF by determining if it also acts on steroidogenic cells of the ovary and adrenal glands and, if so, does it require new protein synthesis. It was found that MDF was produced by human peritoneal macrophages, and was capable of stimulating human steroidogenic cells. In terms of tissue specificity, it was found that primary cultures of rat adrenocortical cells respond to MDF with increased secretion of aldosterone and corticosterone, as did rat granulosa cells by producing progesterone. MDF acted in the presence of cycloheximide, indicating that it does not require new protein synthesis. These results indicate that MDF may have significant therapeutic potential and provide a basis for future studies concerning its physiological role in humans. These results further suggest that MDF is not only involved in paracrine regulation of Leydig cells, but also has the potential for the local regulation of steroidogenesis in both granulosa and adrenal cortical cells. [source] Methyl palmitate inhibits lipopolysaccharide-stimulated phagocytic activity of rat peritoneal macrophagesJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 6 2006Swapna Sarkar Abstract Macrophages, in general, are critical effectors of body's immune system. Chemical inhibition of phagocytic activity of such macrophages as Kupffer cells has been extensively studied. We have earlier shown that methyl palmitate (MP) inhibits the activation of Kupffer cells. To evaluate the potential of MP to inhibit the activation of other macrophages, we treated rat peritoneal macrophages with varying concentrations of MP. Its treatment led to a dose-dependent inhibition of phagocytic activity, which was found to be 34%, 47%, and 66% at 0.25, 0.50, and 1.0 mM MP, respectively, as measured by latex bead uptake. When MP-treated peritoneal macrophages were stimulated with lipopolysaccharide (LPS), the nitric oxide (.NO) release was inhibited at 6 h, while cyclooxygenase-2 expression decreased after 24 h. The treatment with MP increased the release of interleukin (IL)-10 in the LPS-treated cells at 6 h, while IL-6 and tumor necrosis factor-, were significantly increased both at 6 and 24 h. Our data suggest that MP inhibits phagocytic activity and . NO production similar to that observed in isolated Kupffer cells. Therefore, inhibition of phagocytosis by MP may be a general phenomenon, and it could be used as an inhibitor of macrophage function. © 2006 Wiley Periodicals, Inc. J Biochem Mol Toxicol 20:302,308, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20150 [source] A subpopulation of peritoneal macrophages form capillary-like lumens and branching patterns in vitroJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2006Mirela Anghelina Abstract Objective: We have previously shown that monocytes/macrophages (MC/Mph) influence neovascularization by extracellular matrix degradation, and by direct incorporation into growing microvessels. To date, neither the phenotype of these cells, nor the stages of their capillary-like conversion were sufficiently characterized. Methods: We isolated mouse peritoneal Mph from transgenic mice expressing fluorescent proteins either ubiquitously, or specifically in the myelocytic lineage. These Mph were embedded in Matrigel which contained fluorescent protease substrates, exposed to an MCP-1 chemotactic gradient, and then examined by confocal microscopy after various intervals. Results: Within 3 hrs after gel embedding, we detected TIMP-1 and MMP-12 dependent proteolysis of the matrix surrounding Mph, mostly in the direction of high concentrations of MCP-1. After 2 days, Mph developed intracellular vacuoles containing degradation product. At 5 days these vacuoles were enlarged and/or fused to generate trans-cellular lumens in approximately 10% of cells or more (depending on animal's genetic background). At this stage, Mph became tubular, and occasionally organized in three-dimensional structures resembling branched microvessels. Conclusion: Isolated mouse peritoneal Mph penetrate Matrigel and form tunnels via a metalloprotease-driven proteolysis and phagocytosis. Following a morphological adjustment driven by occurrence, enlargement and/or fusion process of intracellular vacuoles, similar to that described in bona fide endothelium, a subpopulation of these cells end up by lining a capillary-like lumen in vitro. Thus we show that adult Mph, not only the more primitive ,endothelial progenitors', have functional properties until now considered defining of the endothelial phenotype. [source] Thrombin induces cyclooxygenase-2 expression and prostaglandin E2 release via PAR1 activation and ERK1/2- and p38 MAPK-dependent pathway in murine macrophagesJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 5 2009Huey-Ming Lo Abstract Thrombin levels increase at sites of vascular injury and during acute coronary syndromes. It is also increased several fold by sepsis with a reciprocal decrease in the anti-thrombin III levels. In this study we investigate the effects of thrombin on the induction of cyclooxygenase-2 (COX-2) and prostaglandin (PG) production in macrophages. Thrombin-induced COX-2 protein and mRNA expression in RAW264.7 and primary cultured peritoneal macrophages. A serine proteinase, trypsin, also exerted a similar effect. The inducing effect by thrombin in macrophages was not affected by a lipopolysaccharide (LPS)-binding antibiotic, polymyxin B, excluding the possibility of LPS contamination. The increase of COX-2 expression by thrombin was functionally linked to release of PGE2 and PGI2 but not thromboxane A2 into macrophage culture medium. Thrombin-induced COX-2 expression and PGE2 production were significantly attenuated by PD98059 and SB202190 but not by SP600125, suggesting that ERK1/2 and p38 MAPK activation were involved in this process. This was supported by the observation that thrombin could directly activate ERK1/2 and p38 MAPK in macrophages. A further analysis indicated that the proteinase-activated receptor 1 (PAR1)-activating agonist induced effects similar to those induced by thrombin in macrophages and the PAR1 antagonist-SCH79797 could attenuate thrombin-induced COX-2 expression and PGE2 release. Taken together, we provided evidence demonstrating that thrombin can induce COX-2 mRNA and protein expression and PGE2 production in macrophages through PAR1 activation and ERK1/2 and p38 MAPK-dependent pathway. The results presented here may explain, at least in part, the possible contribution of thrombin and macrophages in these pathological conditions. J. Cell. Biochem. 108: 1143,1152, 2009. © 2009 Wiley-Liss, Inc. [source] The macrophage chemotactic activity of Edwardsiella tarda extracellular productsJOURNAL OF FISH DISEASES, Issue 5 2008A A Wiedenmayer Abstract The chemoattractant capabilities of Edwardsiella tarda extracellular products (ECP) were investigated from two isolates, the virulent FL6-60 parent and less virulent RET-04 mutant. Chemotaxis and chemokinesis were assayed in vitro using blind well chambers with peritoneal macrophages obtained from Nile tilapia, Oreochromis niloticus, 5 days following squalene injection. Non-purified ECP derived from both isolates stimulated predominantly chemokinetic migration of macrophages. Additionally, the ECP were semi-purified by high pressure liquid chromatography. The FL6-60 parent ECP yielded higher molecular weight components than did the ECP from the RET-04 mutant. The chemotactic activity of the macrophages for both the FL6-60 parent and RET-04 mutant semi-purified ECP was increased over the non-purified ECP and overall migration was primarily chemotactic. Exposure to ECP derived from virulent and less virulent E. tarda isolates promoted chemokinetic movement of macrophages that may be involved in inflammatory responses of Nile tilapia to E. tarda infection. [source] Differential gene expression in LPS/IFN, activated microglia and macrophages: in vitro versus in vivoJOURNAL OF NEUROCHEMISTRY, Issue 2009Christoph D. Schmid Abstract Two different macrophage populations contribute to CNS neuroinflammation: CNS-resident microglia and CNS-infiltrating peripheral macrophages. Markers distinguishing these two populations in tissue sections have not been identified. Therefore, we compared gene expression between LPS (lipopolysaccharide)/interferon (IFN),-treated microglia from neonatal mixed glial cultures and similarly treated peritoneal macrophages. Fifteen molecules were identified by quantative PCR (qPCR) as being enriched from 2-fold to 250-fold in cultured neonatal microglia when compared with peritoneal macrophages. Only three of these molecules (C1qA, Trem2, and CXCL14) were found by qPCR to be also enriched in adult microglia isolated from LPS/IFN,-injected CNS when compared with infiltrating peripheral macrophages from the same CNS. The discrepancy between the in vitro and in vivo qPCR data sets was primarily because of induced expression of the ,microglial' molecules (such as the tolerance associated transcript, Tmem176b) in CNS-infiltrating macrophages. Bioinformatic analysis of the ,19000 mRNAs detected by TOGA gene profiling confirmed that LPS/IFN,-activated microglia isolated from adult CNS displayed greater similarity in total gene expression to CNS-infiltrating macrophages than to microglia isolated from unmanipulated healthy adult CNS. In situ hybridization analysis revealed that nearly all microglia expressed high levels of C1qA, while subsets of microglia expressed Trem2 and CXCL14. Expression of C1qA and Trem2 was limited to microglia, while large numbers of GABA+ neurons expressed CXCL14. These data suggest that (i) CNS-resident microglia are heterogeneous and thus a universal microglia-specific marker may not exist; (ii) the CNS micro-environment plays significant roles in determining the phenotypes of both CNS-resident microglia and CNS-infiltrating macrophages; (iii) the CNS microenvironment may contribute to immune privilege by inducing macrophage expression of anti-inflammatory molecules. [source] Interleukin-12 P40 induces the expression of TNF-, in microglia and macrophagesJOURNAL OF NEUROCHEMISTRY, Issue 2002M. Jana Recently, it has been found that overproduction of IL-12 can be dangerous to the host as it is involved in the pathogenesis of a number of autoimmune inflammatory diseases such as multiple sclerosis. It is composed of two different subunits , p40 and p35. Expression of p40 mRNA but not that of p35 mRNA in excessive amount in the CNS of patients with Multiple Sclerosis (MS) suggests that IL-12 p40 may have a role in the pathogenesis of the disease. The present study was undertaken to explore the role of p40 in the expression of TNF-, in microglia. Interestingly, we have found that IL-12 p70, p402 (the p40 homodimer) and p40 (the p40 monomer) dose-dependently induced the production of TNF-, in BV-2 microglial cells. This induction of TNF-, production was accompanied by an induction of TNF-, mRNA. In addition to BV-2 glial cells, p70, p402 and p40 also induced the production of TNF-, in mouse primary microglia and peritoneal macrophages. Since the activation of both NF-,B and C/EBPb is important for the expression of TNF-, in microglial cells, we investigated the effect of p40 on the activation of NF-,B as well as C/EBPb. Activation of NF-,B as well as C/EBPb by p40 and inhibition of p40-induced expression of TNF-, by Dp65, a dominant-negative mutant of p65, and DC/EBPb, a dominant-negative mutant of C/EBPb, suggests that p40 induces the expression of TNF-, through the activation of NF-,B and C/EBPb. This study delineates a novel role of IL-12 p40 in inducing the expression of TNF-, in microglial cells which may participate in the pathogenesis of neuroinflammatory diseases. Acknowledgements:, This study was supported by NIH grants (NS39940 and AG19487). [source] Blockade of chloride intracellular ion channel 1 stimulates A, phagocytosisJOURNAL OF NEUROSCIENCE RESEARCH, Issue 11 2008Silvia Paradisi Abstract In amyloid-, (A,)-stimulated microglial cells, blockade of chloride intracellular ion channel 1 (CLIC1) reverts the increase in tumor necrosis factor-, and nitric oxide (NO) production and results in neuroprotection of cocultured neurons. This effect could be of therapeutic efficacy in Alzheimer's disease (AD), where microglial activation may contribute to neurodegeneration, but it could reduce A, phagocytosis, which could facilitate amyloid plaque removal. Here, we analyzed the CLIC1 blockade effect on A,-stimulated mononuclear phagocytosis. In the microglial cell line BV-2, A,25,35 treatment enhanced fluorescent bead phagocytosis, which persisted also in the presence of IAA-94, a CLIC1 channel blocker. The same result was obtained in rat primary microglia and in BV2 cells, where CLIC1 expression had been knocked down with a plasmid producing small interfering RNAs. To address specifically the issue of A, phagocytosis, we treated BV-2 cells with biotinylated A,1,42 and measured intracellular amyloid by morphometric analysis. IAA-94-treated cells showed an increased A, phagocytosis after 24 hr and efficient degradation of ingested material after 72 hr. In addition, we tested A,1,42 phagocytosis in adult rat peritoneal macrophages. Also, these cells actively phagocytosed A,1,42 in the presence of IAA-94. However, the increased expression of inducible NO synthase (iNOS), stimulated by A,, was reverted by IAA-94. In parallel, a decrease in NO release was detected. These results suggest that blockade of CLIC1 stimulates A, phagocytosis in mononuclear phagocytes while inhibiting the induction of iNOS and further point to CLIC1 as a possible therapeutic target in AD. © 2008 Wiley-Liss, Inc. [source] Vascular endothelial growth factor (VEGF)-induced angiogenesis in herniated disc resorptionJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2002Hirotaka Haro Abstract Intervertebral disc herniation is a major cause of low back pain and sciatica. Spontaneous resorption of herniated disc (HD) is frequently detected by magnetic resonance imaging (MRI). Marked infiltration by macrophages and neo-vascularization are observed upon histogical examination of HD. In addition, enhanced MRI studies suggest that HD resorption occurs more frequently in those completely exposed to the epidural space and that this correlates with their degree of vascularization. We have postulated that the angiogenic factor, vascular endothelial growth factor (VEGF), may be implicated in the neo-vascularization of HD tissues. Here we demonstrate that VEGF and its receptors VEGFR-1 and VEGFR-2 are expressed in human surgical samples of HD. Using a co-culture system comprised of murine peritoneal macrophages and intervertebral disc tissue as a model of the acute phase of HD developed previously, an increase in macrophage VEGF protein and mRNA expression was observed upon exposure to disc tissue. Tumor necrosis factor alpha (TNF-,) was required for this induction of VEGF. Use of a novel angiogenesis assay revealed that addition of the conditioned media from the co-culture system resulted in an increase of vascular tubule formation. This effect was strongly inhibited by anti-VEGF antibody, but augmented by recombinant VEGF. We conclude that VEGF induction, under the co-culture conditions tested can result in neo-vascularization of intervertebral disc tissue and may thus play a role in the resorption of HD. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Enhanced monocyte migration and pro-inflammatory cytokine production by Porphyromonas gingivalis infectionJOURNAL OF PERIODONTAL RESEARCH, Issue 2 2010A. Pollreisz Pollreisz A, Huang Y, Roth GA, Cheng B, Kebschull M, Papapanou PN, Schmidt AM, Lalla E. Enhanced monocyte migration and pro-inflammatory cytokine production by Porphyromonas gingivalis infection. J Periodont Res 2009; doi: 10.1111/j.1600-0765.2009.01225.x. © 2009 The Authors. Journal compilation © 2009 Blackwell Munksgaard Background and Objective:,Porphyromonas gingivalis, a major periodontal pathogen, has been reported to be involved in atherogenesis. In order to further understand this pathogen's link with systemic inflammation and vascular disease, we investigated its influence on murine monocytes and macrophages from three different sources. Material and Methods:, Concanavalin A-elicited peritoneal macrophages, peripheral blood monocyte-derived macrophages and WEHI 274.1 monocytes were infected with either P. gingivalis 381 or its non-invasive fimbriae-deficient mutant, DPG3. Results:, Infection with P. gingivalis 381 markedly induced monocyte migration and significantly enhanced production of the pro-inflammatory cytokines, tumor necrosis factor-, and interleukin-6. Consistent with a role for this pathogen's major fimbriae and/or its invasive capacity, infection with DPG3 had a minimal effect on both monocyte attraction and pro-inflammatory cytokine production. Conclusion:, Since monocyte recruitment and activation are important steps in the development of vascular inflammation and atherosclerosis, these results suggest that P. gingivalis infection may be involved in these processes. [source] Cellular activation by plasmid DNA in various macrophages in primary cultureJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 10 2008Hiroyuki Yoshida Abstract Macrophages are an important group of cells responsible for the inflammatory response to unmethylated CpG dinucleotide (CpG motif) in plasmid DNA (pDNA) via Toll-like receptor 9 (TLR9). This finding is primarily based on in vitro studies. Previous in vivo studies also have suggested that tissue macrophages are involved in inflammatory cytokine release in the circulation following intravenous administration of pDNA to mice. However, the relationship between the in vitro and in vivo studies has not been sufficiently clarified. To gain insight into which types of cells are responsible for the production of cytokines upon interaction with pDNA, peritoneal macrophages, splenic macrophages, hepatic nonparenchymal cells (NPCs) including Kupffer cells and mesangial cells were isolated from mice. All types of primary cultured cells, except for mesangial cells, express TLR9 at varying levels. Splenic macrophages and hepatic NPCs were activated to produce tumor necrosis factor-, (TNF-,) by naked pDNA, whereas peritoneal macrophages and mesangial cells were not. pDNA complexed with N -[1-(2,3-dioleyloxy)propyl]- N,N,N -trimethyl-ammonium chloride/cholesterol liposome induced TNF-, in the splenic macrophages but not in the other cell types. These results indicate that splenic macrophages and hepatic NPCs are closely involved in TNF-, production in response to pDNA. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:4575,4585, 2008 [source] Fructus Ligustrum lucidi inhibits inflammatory mediator release through inhibition of nuclear factor-,B in mouse peritoneal macrophagesJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 9 2007Hyo-Jin An ABSTRACT Fructus Ligustrum lucidi (FLL) is a widely used herbal medicine for the treatment of a variety of pathologies. We have investigated the anti-inflammatory mechanism of FLL in mouse peritoneal macrophages. FLL exerted an anti-inflammatory action through inhibition of lipopolysaccharide (LPS)-induced tumour necrosis factor (TNF)-, production in mouse peritoneal macrophages. The maximal inhibition rate of TNF-, production by FLL (0.5 mg mL,1) was 60.88 + 0.30%. In the inflammatory process, nitric oxide (NO) and prostaglandin E2 (PGE2) increased in peritoneal macrophages. FLL decreased the protein level of NO and PGE2 in LPS-stimulated mouse peritoneal macrophages. In addition, FLL inhibited nuclear factor-,B activation and I,B-, degradation by the decrease in I,B-, phosphorylation. Our study suggested that FLL reduced inflammation via an important molecular mechanism, which might explain its beneficial effect in the regulation of inflammatory reactions. [source] Enhancement of natural killer cell activity of aged mice by modified arabinoxylan rice bran (MGN-3/Biobran)JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 12 2004Mamdooh Ghoneum The present study is aimed to examine the possibility of enhancement of natural killer (NK) cell activity in aged C57BL/6 and C3H mice using MGN-3, a modified arabinoxylan from rice bran. Intraperitoneal injection of MGN-3 (10 mg kg,1 per day) caused a remarkable increase in the peritoneal NK activity as early as 2 days (35.2 lytic units), and the level remained elevated through day 14. The control aged mice had a level of 5.8 lytic units. Enhancement in NK activity was associated with an increase in both the binding capacity of NK cells to tumour targets and in the granular content as measured by BLT-esterase activity. Treatment did not alter the percentage of peritoneal NK cells. Data showed that peritoneal macrophages inhibit NK activity. In conclusion, MGN-3 enhances murine NK activity of aged mice and may be useful for enhancing NK function in aged humans. [source] Inhibition of TPA-induced NF-,B nuclear translocation and production of NO and PGE2 by the anti-rheumatic gold compoundsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 2 2003Masamichi Yamashita ABSTRACT Auranofin, aurothioglucose and aurothiomalate (10 ,M each) inhibited 12- O -tetradecanoylphorbol 13-acetate (TPA, 16.2 nM)-induced nuclear translocation of nuclear factor-kappa B (NF-,B), and production of nitric oxide (NO) and prostaglandin E2 (PGE2) in rat peritoneal macrophages when the cells were pre-incubated with each gold compound for 20h. Without pre-incubation for 20h, aurothioglucose and aurothiomalate, but not auranofin, failed to inhibit the TPA-induced NF-,B nuclear translocation and production of NO and PGE2. Auranofin, aurothioglucose and aurothiomalate did not affect the direct binding of NF-,B to the DNA probe. It was suggested that these gold compounds inhibit the TPA-induced production of NO and PGE2 by inhibiting the NF-,B nuclear translocation. [source] | |||||||||||||||||||||||||||||||