Journal of Leukocyte Biology Biosymposia, Inc.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Originally published online as doi:10.1189/jlb.0906576 on May 15, 2007

Published online before print May 15, 2007
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
jlb.0906576v1
82/2/320    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Mosca, M.
Right arrow Articles by Mantovani, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Mosca, M.
Right arrow Articles by Mantovani, A.
(Journal of Leukocyte Biology. 2007;82:320-326.)
© 2007 by Society for Leukocyte Biology

Regulation of the microsomal prostaglandin E synthase-1 in polarized mononuclear phagocytes and its constitutive expression in neutrophils

Michela Mosca*,1, Nadia Polentarutti{dagger}, Giorgina Mangano{ddagger}, Claudia Apicella{ddagger}, Andrea Doni{dagger}, Francesca Mancini{ddagger}, Maida De Bortoli*, Isabella Coletta{ddagger}, Lorenzo Polenzani{ddagger}, Giorgio Santoni§, Marina Sironi{dagger}, Annunciata Vecchi{dagger},2 and Alberto Mantovani{dagger},||

* Department of Immunology and Cell Biology, Istituto Ricerche Farmacologiche Mario Negri, Milan, Italy;
{dagger} Istituto Clinico Humanitas, Rozzano, Italy;
{ddagger} Angelini Farmaceutici-A.C.R.A.F., Piazzale della Stazione, Rome, Italy;
§ Department of Experimental Medicine and Public Health, Università of Camerino, Italy; and
|| Institute of General Pathology, Medical Faculty, University of Milan, Italy

2 Correspondence: Istituto Clinico Humanitas, via Manzoni 56, 20089 Rozzano (MI), Italy. E-mail: annunciata.vecchi{at}humanitas.it


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
PGs are potent mediators of pain and inflammation. PGE synthases (PGES) catalyze the isomerization of PGH2 into PGE2. The microsomal (m)PGES-1 isoform serves as an inducible PGES and is responsible for the production of PGE2, which mediates acute pain in inflammation and fever. The present study was designed to investigate the regulation of expression of mPGES-1 in polarized phagocytes, which represent central, cellular orchestrators of inflammatory reactions. Here, we report that human peripheral blood monocytes did not express mPGES-1. Exposure to LPS strongly induced mPGES-1 expression. Alternatively activated M2 monocytes-macrophages exposed to IL-4, IL-13, or IL-10 did not express mPGES-1, whereas in these cells, IL-4, IL-13, and to a lesser extent, IL-10 or IFN-{gamma} inhibited LPS-induced, mPGES-1 expression. It is unexpected that polymorphonuclear leukocytes expressed high basal levels of mPGES-1, which was up-regulated by LPS and down-regulated by IL-4 and IL-13. Induction of mPGES-1 and its modulation by cytokines were confirmed at the protein level and correlated with PGE2 production. Cyclooxygenase 2 expression tested in the same experimental conditions was modulated in monocytes and granulocytes similarly to mPGES-1. Thus, activated M1, unlike alternatively activated M2, mononuclear phagocytes express mPGES-1, and IL-4, IL-13, and IL-10 tune expression of this key enzyme in prostanoid metabolism. Neutrophils, the first cells to enter sites of inflammation, represent a ready-made, cellular source of mPGES-1.

Key Words: cytokines • PGE2 • COX-2 • inflammation


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
PGE2 is a lipid mediator with a key role in many physiological processes, including gastrointestinal and renal functions, vascular homeostasis, bone remodeling, fever induction, pregnancy, and acute inflammation. PGE synthase (PGES) is the terminal enzyme of the pathway of PGE2 production, controlling the amount of PGE2 produced. At least three distinct PGES isoforms have been identified, including cytosolic PGES (cPGES) [1 , 2 ], microsomal PGES-1 (mPGES-1) [2 3 4 ], and mPGES-2 [5 ]. cPGES is expressed constitutively and ubiquitously and is preferentially coupled with cyclooxygenase-1 (COX)-1, promoting immediate production of PGE2 [1 , 6 ], and mPGES-1 is up-regulated by proinflammatory stimuli, such as IL-1β, TNF-{alpha}, and LPS, and is functionally coupled with COX-2, promoting delayed PGE2 synthesis [3 ]. mPGES-2, the more recently identified PGES, is expressed ubiquitously in diverse tissues and is linked functionally to COX-1 and COX-2, but its physiological and pathological role remains elusive [7 ].

Basal and induced expression of mPGES-1 in some organs has been reported in mice, rat, and man [2 , 4 , 8 ]. Although the mPGES-1 form is highly inducible, a constitutive expression has been reported in ovary, kidney, and bladder. mPGES-1 colocalizes with COX-2, but in selected conditions, such as, for instance, gastric adenocarcinomas [9 ], normal epithelial cells express only mPGES but not COX-2, and tumor cells have both enzymes. Moreover, the kinetics of the induction of mPGES-1 and COX-2 has been reported to be different [10 11 12 ], suggesting a differential regulation of these enzymes.

The ability of proinflammatory stimuli (IL-1β, TNF-{alpha}, and LPS) to induce mPGES-1, reported in in vitro and in vivo conditions [9 , 12 , 13 ], suggests that the regulation of mPGES-1 induction tunes inflammation. The relevance of mPGES-1 in the control of inflammation-induced PGE2 production was demonstrated recently in mPGES-1-deficient mice. LPS-induced PGE2 production was abrogated almost completely in vivo and in vitro, and TNF-{alpha} and IL-6 production was unaffected [14 ]. Moreover mPGES-1–/– mice exhibited reduced, inflammatory responses and inflammatory pain in a model of collagen-induced arthritis, suggesting that mPGES-1 is involved in acute and chronic inflammation [14 15 16 ].

Anti-inflammatory drugs controlling PGE2 production through the inhibition of COX-2 have been developed and used clinically with some advantages compared with classical, nonsteroidal, anti-inflammatory drugs, but they have adverse effects such as renal toxicity and increased risk of cardiovascular events and thrombosis [17 ]. Thus, interest has shifted to enzymes, such as mPGES-1, downstream of the COXs, as potential targets for novel, anti-inflammatory interventions.

Polymorphonuclear and mononuclear phagocytes are recruited in a temporally regulated manner at sites of inflammation and are central, cellular orchestrators of inflammatory reactions. Macrophages are plastic cells, which undergo polarized forms of activation in response to diverse environmental signals [18 , 19 ] and are part of regulatory circuits of polarized responses [18 19 20 21 ]. Recently, we proposed [19 ] M2 as a generic name for the various forms ("alternatively activated" sensu strictu; Type II; Mø2; M2) of macrophage activation other than the classic M1, and three forms of M2 have been well-defined: M2a (where "a" also stands for alternative), induced by IL-4 or IL-13; M2b, induced by exposure to immune complexes and agonists of TLRs or IL-1R; and M2c, induced by IL-10 and glucocorticoid hormones. Polymorphonuclear leukocytes too have been described to express polarized effector functions [22 , 23 ]. Yet, no data are available about mPGES-1 expression and regulation in phagocytes exposed to polarizing signals.

Here, we report that mononuclear phagocytes are induced to express mPGES-1 by inflammatory stimuli and that mPGES-1 is regulated by cytokines. It is unexpected that we found that polymorphonuclear leukocytes constitutively express mPGES-1 and suggest that neutrophils, the first cells to enter sites of inflammation, represent a ready-made, cellular source of mPGES-1. Recent findings demonstrate that neutrophils are able to communicate with dendritic cells (DC), providing a link between innate and adaptive immunity [24 ], and that DC migration toward CCR7 ligands needs PGE2 during DC maturation [25 26 27 ]. Thus, neutrophils recruited at sites of inflammation can represent a source of PGE2 for DC maturation and efficient migration to lymph nodes.


   MATERIALS AND METHODS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
RESULTS
 DISCUSSION
 REFERENCES
 
Human leukocytes
Circulating human monocytes, lymphocytes, and polymorphonuclear cells were obtained from peripheral blood of healthy donors. Cells were separated by Percoll (Pharmacia, Uppsala, Sweden) gradient centrifugation as described [28 ]. Monocyte-derived macrophages were obtained from freshly isolated monocytes after incubation for 5 days in RPMI-1640 medium supplemented with 40% autologous serum as described [29 ]. NK cells were obtained through a Ficoll (Biochrome) gradient, monocyte depletion and discontinous Percoll gradient. Large B cells were prepared from tonsils as described [30 ]. To induce mPGES-1, monocytes (3–5x106/ml) and peritoneal macrophages and neutrophils (PMN; 5–7x106/ml) were cultured in RPMI 1640 with 1% FCS for 20 h in the absence or presence of LPS (100 ng/ml) from Escherichia coli, Strain 055:B5 (Difco Laboratories, Detroit, MI, USA). Cells were then processed for the evaluation of mRNA expression in Northern blot analysis or for the measurement of the induced protein by Western blot analysis (see below). To study modulation of enzyme expression, cytokines were added at the same time as LPS. Human (h)IL-4 and hIL-10 were donated by Schering-Plough Research Institute (Dardilly, France), hIL-13 was a gift from Sanofi Elf Bio Recherches (Labège, France), hIFN-{gamma} was from PeproTech (Rocky Hill, NJ, USA), mIL-4 was from Immunex (Seattle, WA, USA), mIL-10 was from DNAX Research Institute (Palo Alto, CA, USA), and mIFN-{gamma} was from Hoffmann-LaRoche (Basel, Switzerland).

Cell line
The nonsmall lung cancer human adenocarcinoma cell line A549 (ATCC Number CCL-185) was grown in RPMI-1640 medium with 10% FCS.

Mouse leukocytes
Murine PMN were collected from the peritoneal cavity of 8- to 10-week-old C57Bl/6N mice from Charles River Laboratories (Calco, Italy) 5 days and 4 h, respectively, after the i.p. injection of 1 ml 3% sterile thioglycollate (Difco Laboratories). For enzyme induction, macrophages (1x106/ml) were cultured in RPMI 1640 with 1% FCS for 20 h in the absence or presence of LPS, 100 ng/ml, and medium or cytokines. PMN were used just after collection. Procedures involving animals and their care conformed to institutional guidelines in compliance with national (4D.L. N.116, G.U., Suppl. 40, 18-2-1992) and international law and policies (EEC Council Directive 86/609, OJ L 358, 1, 12-12-1987, National Institutes of Health Guide for the Care and Use of Laboratory Animals, U.S. National Research Council, 1996). All efforts were made to minimize the number of animals used and their suffering.

Northern blot analysis
Total RNA was isolated from mouse and human cells by the guanidine isothiocyanate method. Total RNA (8–10 µg) was analyzed by electrophoresis through 1% agarose/formaldehyde gels, followed by Northern blot transfer to Gene Screen Plus membranes. Expression analysis of mPGES-1 and COX-2 in human samples was performed using specific probes. PGES (human) cDNA probe was purchased by Cayman Chemical Co. (Ann Arbor, MI, USA). Human COX-2 probe was prepared as published [31 ] to obtain a 1.8-kb fragment, inserted in expression vector pcDNAI/Neo into HindIII/NotI cloning sites. For the analysis of mouse samples, a specific mPGES-1 probe was prepared from mouse ovary RNA, amplified by RT-PCR with specifically designed oligos (forward, 5'TCC AGG CCG GCT AGC CGA GAT, and reverse, 5'TGG GCT GGG CCA GAA TTG TAG) to obtain a cDNA fragment of 800 bp. The product was subcloned in pGEM easy vector (Promega, Madison, WI, USA), amplified, and sequenced. The specific probe (800 bp) was obtained after digestion with EcoRI. Human and mouse probes were labeled with ({alpha}-32P)dCTP, using the Megaprime DNA labeling system (Amersham, Little Chalfont, UK).

Western blot analysis and PGE2 production
Microsomal fractions obtained by ultracentrifugation of cell lysates were separated by SDS-PAGE (12.5% acrylamide) under standard conditions [10 ], and anti-mPGES-1 mAb (from Cayman Chemical Co., Cat. Number 10004350) were used to detect the protein. PGE2 was measured in cell supernatants by a commercially available enzyme immunosorbent assay (EIA) kit (Cayman Chemical Co.).

Confocal microscopy analysis
Cytospins were fixed with 4% paraformaldehyde, permeabilized for 5 min with 0.3% Triton (Sigma-Aldrich, St. Louis, MO, USA) in PBS, pH 7.4, before incubation for 1 h at 4°C with 5% normal goat serum (Sigma-Aldrich) and 5% human normal serum. Cells were then incubated for 2 h at 4°C with 1 µg/ml of a mouse anti-PGES-1 mAb (Cayman Chemical Co.) or with isotype control mAb. Slides were incubated (1 h at room temperature) with an Alexa® Fluor 488-conjugated goat anti-mouse IgG antibody, followed by 1 µg/ml 4'6,diamidino-2-phenylindole (Invitrogen-Molecular Probes, Carlsbad, CA, USA). In each step, cells were washed with 0.2% BSA, 0.05% Tween 20, in PBS (pH 7.4). Slides were mounted with FluorSaveTM reagent (Calbiochem, San Diego, CA, USA) and analyzed with an Olympus Fluoview FV1000 laser-scanning confocal microscope. Images (1024x1024 pixels) were acquired with a 60x 1.4 NA Plan-Apochromat oil immersion objective (Olympus, Hamburg, Germany). The software FV10-ASW 1.6 (Olympus) was used for analysis of fluorescence intensity quantification. Results are expressed as percentage of mPGES-1-positive cells and average of fluorescence intensity values of single cells considered as specific regions of interest.


   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
DISCUSSION
 REFERENCES
 
Different human leukocyte populations were tested for the expression of mPGES-1 in basal or LPS-stimulated conditions, and results are in Figure 1 . Under resting conditions, only PMN expressed mPGES-1 mRNA, and monocytes, T lymphocytes, macrophages, NK cells, and B lymphocytes did not express it. Exposure to LPS for 4 or 20 h induced mPGES-1 expression in monocytes and macrophages (Fig. 1) . The basal expression of mPGES-1 in PMN was augmented further by LPS (Fig. 1) .


Figure 1
View larger version (56K):
[in this window]
[in a new window]

  		Figure 1. Northern blot analysis of the expression of mPGES-1 in human monocytes (MONO) and PMN. Purified cells were exposed to 100 ng/ml LPS for 4 or 20 h, as indicated. Exposure of the blot was 7 days for mPGES-1 and COX-2. Results are representative of two experiments performed. The lower part of the panel shows the ethidium bromide staining after RNA transfer to the membrane. Total RNA (10 µg) was used in each lane. T-LYMPH, T lymphocyte; MACRO, macrophage.

 
Modulation of mPGES-1 expression in monocytes by cytokine exposure was investigated next. IL-4, IL-10, IL-13, and IFN-{gamma} did not induce enzyme expression. When tested on LPS-stimulated monocytes, IL-4, IL-13, and IL-10 inhibited mPGES-1 expression, and IL-4 and IL-13 were the most active; IFN-{gamma} had no effect (Fig. 2 ). Next, the effect of cytokines was tested on PMN (Fig. 3 ). Given the basal expression of mPGES-1 in PMN, exposure of the blot was shorter (48 h) than for results reported in Figure 2 (7 days) to allow a better visualization of the stimulation. IL-4, IL-13, and IFN-{gamma} inhibited the basal expression of mPGES-1. Exposure for 20 h to LPS increased mPGES-1 expression in the PMN; IL-4, IL-13, and IFN-{gamma} markedly inhibited the LPS-induced mPGES-1 expression, and IL-10 was less active.


Figure 2
View larger version (64K):
[in this window]
[in a new window]

  		Figure 2. Northern blot analysis of the regulation of mPGES-1 and COX-2 expression in human monocytes, which were exposed for 20 h to cytokines (IL-4, IL-10, and IL-13: 20 ng/ml; IFN-{gamma}: 500 U/ml), LPS (100 ng/ml), and combinations thereof. Exposure of the blot was 7 days for mPGES-1 and 2 days for COX-2. Results are from one experiment representative of four. The lower part of the panel shows the ethidium bromide staining after RNA transfer to the membrane. Total RNA (10 µg) was used in each lane.

 

Figure 3
View larger version (61K):
[in this window]
[in a new window]

  		Figure 3. Northern blot analysis of the regulation of mPGES-1 and COX-2 expression in human PMN, which were exposed for 20 h to cytokines, LPS, and combinations thereof. Exposure of the blot was 2 days for mPGES-1 and 7 days for COX-2. Results are from one experiment representative of four. The lower part of the panel shows the ethidium bromide staining after RNA transfer to the membrane. Total RNA (10 µg) was used in each lane. Cytokine and LPS concentrations were as in Figure 2 .

 
The constitutive and inflammation-induced expression of mPGES-1 was confirmed at the protein level. Western blot analysis of microsomal fractions of monocyte lysates is shown in Figure 4 . mPGES-1 protein was detectable only in LPS-treated cells, and it was inhibited by concomitant exposure to IL-4, in good agreement with the results obtained with mRNA. The amount of mPGES-1 detectable in monocytes was low, if compared with the protein detectable in the A549 cell line, used as a reference sample [10 ]. The percentage of enzyme-expressing cells and the intensity of the fluorescence in each positive cell were also evaluated by confocal microscopy. Representative images are shown in Figures 5 and 6 for monocytes and PMN, respectively. Cytokines modulated mPGES-1 production, in agreement with their effects on mRNA induction, IL-4-inhibiting protein expression in monocytes and PMN more than IL-10 and IFN-{gamma} inhibiting mPGES-1 only in PMN.


Figure 4
View larger version (28K):
[in this window]
[in a new window]

  		Figure 4. Western blot analysis of the induction and modulation of mPGES-1 in monocytes, which were exposed for 20 h to cytokines, LPS, and their combinations. The amount of microsomal proteins per lane was 50 µg from monocytes and 20 µg from A549 cells. Results are from one experiment representative of two. IL-4 and LPS concentrations were as in Figure 2 .

 

Figure 5
View larger version (28K):
[in this window]
[in a new window]

  		Figure 5. Confocal microscopy analysis of the induction and modulation of mPGES-1 in monocytes, which were exposed for 20 h to cytokines and combinations thereof. Cytokine and LPS concentrations as in Figure 2 . (A) Representative images of mPGES-1 induction and regulation (blue: nuclei; red: mPGES-1). (B) The percentage of the cells positive for the protein. *, P < 0.05, by t-test versus medium; and §, P < 0.05, versus LPS alone. (C) The mean values of fluorescence intensity of positive cells. Results are mean ± SE from three donors.

 

Figure 6
View larger version (31K):
[in this window]
[in a new window]

  		Figure 6. Confocal microscopy analysis of the induction and modulation of mPGES-1 in PMN, which were exposed for 20 h to cytokines and combinations thereof. Cytokine and LPS concentrations as in Figure 2 . (A) Representative images of mPGES-1 induction and regulation (blue: nuclei; red: mPGES-1). (B) The percentage of the cells positive for the protein. *, P < 0.05, by t-test versus medium; and §, P < 0.05, versus LPS alone. (C) The mean values of fluorescence intensity of positive cells. Results are mean ± SE from three donors.

 
To further evaluate the relevance of cytokine modulation of mPGES-1, PGE2 levels were measured in the supernatants of monocytes and PMN. Results are in agreement with mPGES-1 expression data (Fig. 7 ). Baseline production was only detectable in PMN but not in monocytes, although upon exposure to LPS, monocytes were better producers of PGE2. Only PGE2 production by PMN stimulated with LPS in the presence of IFN-{gamma} did not correspond to mPGES-1 data, suggesting that IFN-{gamma} could interfere with other pathways of PGE2 production/regulation in these cells, as suggested also by the lack of inhibition of COX-2 mRNA (see below; Fig. 3 ). It is interesting that IFN-{gamma} has been shown to differentially affect chemokine production in monocytes and PMN, suggesting a distinct control of regulatory pathways [32 , 33 ].


Figure 7
View larger version (18K):
[in this window]
[in a new window]

  		Figure 7. PGE2 production by monocytes and PMN. Monocytes or PMN were cultured for 20 h with cytokines and combinations thereof. Cytokine and LPS concentrations were as in Figure 2 . PGE2 was measured by EIA in cell supernatants. Results are mean ± SE from three (monocytes) and four (PMN) donors. *, P < 0.05, by t-test versus LPS alone.

 
It has been reported that mPGES-1 colocalizes with COX-2 and that the two enzymes are linked functionally, although their expression kinetics can differ, suggesting a differential regulation of induction. The expression of COX-2 was analyzed in human monocytes and PMN and compared with that of mPGES-1. Resting monocytes and PMN did not express COX-2. Cytokines had no effect on the basal expression of COX-2 in both cell types (Figs. 2 and 3 , lower panels), but they modulated LPS-induced expression. In monocytes (Fig. 2) at 20 h, COX-2 was inhibited by IL-4 and IL-13 more than by IL-10 and much more than by IFN-{gamma}. In PMN (Fig. 3) , IL-4, IL-13, and IL-10 but not IFN-{gamma} strongly inhibited COX-2 expression.

Mouse macrophages express mPGES-1 after exposure to inflammatory stimuli, as LPS, IL-1β, and TNF-{alpha} [13 ], but no data are available for PMN and on mPGES-1 modulation in polarized murine cells. mPGES-1 modulation by cytokines was thus investigated also in experimental models useful for in vivo studies. Peritoneal macrophages from thioglycollate-injected mice did not express detectable levels of mRNA in basal conditions (Fig. 8 ); exposure to LPS but not to IL-4, IL-10, and IFN-{gamma} induced mPGES-1 expression, which was down-regulated when cytokines were present during LPS stimulation. mPGES-1 was constitutively expressed in PMN (Fig. 8) , in agreement with data about human leukocytes.


Figure 8
View larger version (53K):
[in this window]
[in a new window]

  		Figure 8. Expression and regulation of mPGES-1 in mouse macrophages and PMN. Thioglycollate-elicited (5 days) peritoneal macrophages were purified by 2 h of adhesion in medium without serum. Stimuli (mIL-4 and IL-10: 20 ng/ml; mIFN{gamma}: 100 U/ml; LPS: 100 ng/ml) were then added to cells in medium with 10% FCS. PMN were recovered from the peritoneal cavity of thioglycollate-injected mice (4 h) and tested immediately. Exposure of the blot was 2 days. Results are representative of two experiments performed. The lower part of the panel shows the ethidium bromide staining after RNA transfer to the membrane. Total RNA (10 µg) was used in each lane for macrophages and 2.5 µg for PMN.

 

   DISCUSSION
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
REFERENCES
 
Eicosanoids have long been known to play a key role in inflammation and to represent a target for pharmacological intervention. By promoting DC maturation, PGE2 also helps the activation of adaptive immunity [34 35 36 ]. mPGES-1 is the inducible end enzyme in the production of PGE2, functionally coupled to COX-2 [3 , 7 ]. Accordingly, mPGES-1 gene-targeted mice are protected against various forms of inflammatory reactions [14 15 16 , 37 ].

Phagocytes play a central role in inflammation and tissue remodeling and are a major source of and target of eicosanoids. mPGES-1 is induced in murine macrophages by signals, such as LPS [13 ], which elicit a classic form of activation [20 ], a finding extended in the present study to human mononuclear phagocytes. Macrophages can undergo alternative forms of activation (M2) in response to signals such as IL-4, IL-13, and IL-10. M2 macrophages have immunoregulatory functions and promote tissue remodeling and repair [18 , 19 , 38 ]. The results presented here indicate that alternatively activated macrophages do not express mPGES-1 and its companion COX-2. Moreover, the anti-inflammatory cytokines [39 ] IL-4, IL-13, and to a lesser extent, IL-10 suppress mPGES-1 induction and expression, resulting in decreased levels of PGE2 released by the cells. Suppression of mPGES-1 expression is likely to play a key role in the tuning and orientation of inflammation by IL-4, IL-13, and IL-10.

It is unexpected that we found that neutrophils constitutively express substantial levels of mPGES-1, which in mature myelocytes, is subjected to the same regulatory signals as in monocytes-macrophages. Neutrophils are key elements in inflammation and innate immunity [40 , 41 ] and are the first cells to enter sites of inflammatory reactions. Expression of mPGES-1 may render neutrophils a ready-made source of PGE2 for rapid amplification of inflammation and promotion of adaptive immunity, favoring maturation and efficient migration of DC to lymph nodes for antigen presentation [25 26 27 ].


   ACKNOWLEDGEMENTS
 
Fondazione Cariplo (Project NOBEL) and FIRB RBLA039LSF, supported this work. The generous contribution of the Italian Association for Cancer Research (AIRC) is gratefully acknowledged.


   FOOTNOTES
 
1 Current address: Department of Experimental Medicine and Public Health, University of Camerino, Italy. Back

Received September 19, 2006; revised April 4, 2007; accepted April 12, 2007.


   REFERENCES
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. Tanioka, T., Nakatani, Y., Semmyo, N., Murakami, M., Kudo, I. (2000) Molecular identification of cytosolic prostaglandin E2 synthase that is functionally coupled with cyclooxygenase-1 in immediate prostaglandin E2 biosynthesis J. Biol. Chem. 275,32775-32782[Abstract/Free Full Text]
  2. Jakobsson, P. J., Thoren, S., Morgenstern, R., Samuelsson, B. (1999) Identification of human prostaglandin E synthase: a microsomal, glutathione-dependent, inducible enzyme, constituting a potential novel drug target Proc. Natl. Acad. Sci. USA 96,7220-7225[Abstract/Free Full Text]
  3. Murakami, M., Naraba, H., Tanioka, T., Semmyo, N., Nakatani, Y., Kojima, F., Ikeda, T., Fueki, M., Ueno, A., Oh, S., Kudo, I. (2000) Regulation of prostaglandin E2 biosynthesis by inducible membrane-associated prostaglandin E2 synthase that acts in concert with cyclooxygenase-2 J. Biol. Chem. 275,32783-32792[Abstract/Free Full Text]
  4. Mancini, J. A., Blood, K., Guay, J., Gordon, R., Claveau, D., Chan, C. C., Riendeau, D. (2001) Cloning, expression, and up-regulation of inducible rat prostaglandin E synthase during lipopolysaccharide-induced pyresis and adjuvant-induced arthritis J. Biol. Chem. 276,4469-4475[Abstract/Free Full Text]
  5. Tanikawa, N., Ohmiya, Y., Ohkubo, H., Hashimoto, K., Kangawa, K., Kojima, M., Ito, S., Watanabe, K. (2002) Identification and characterization of a novel type of membrane-associated prostaglandin E synthase Biochem. Biophys. Res. Commun. 291,884-889[CrossRef][Medline]
  6. Tanioka, T., Nakatani, Y., Kobayashi, T., Tsujimoto, M., Oh-ishi, S., Murakami, M., Kudo, I. (2003) Regulation of cytosolic prostaglandin E2 synthase by 90-kDa heat shock protein Biochem. Biophys. Res. Commun. 303,1018-1023[CrossRef][Medline]
  7. Murakami, M., Nakashima, K., Kamei, D., Masuda, S., Ishikawa, Y., Ishii, T., Ohmiya, Y., Watanabe, K., Kudo, I. (2003) Cellular prostaglandin E2 production by membrane-bound prostaglandin E synthase-2 via both cyclooxygenases-1 and -2 J. Biol. Chem. 278,37937-37947[Abstract/Free Full Text]
  8. Guan, Y., Zhang, Y., Schneider, A., Riendeau, D., Mancini, J. A., Davis, L., Komhoff, M., Breyer, R. M., Breyer, M. D. (2001) Urogenital distribution of a mouse membrane-associated prostaglandin E(2) synthase Am. J. Physiol. Renal Physiol. 281,F1173-F1177[Abstract/Free Full Text]
  9. Van Rees, B. P., Sivula, A., Thoren, S., Yokozaki, H., Jakobsson, P. J., Offerhaus, G. J., Ristimaki, A. (2003) Expression of microsomal prostaglandin E synthase-1 in intestinal type gastric adenocarcinoma and in gastric cancer cell lines Int. J. Cancer 107,551-556[CrossRef][Medline]
  10. Thoren, S., Jakobsson, P. J. (2000) Coordinate up- and down-regulation of glutathione-dependent prostaglandin E synthase and cyclooxygenase-2 in A549 cells. Inhibition by NS-398 and leukotriene C4 Eur. J. Biochem. 267,6428-6434[Medline]
  11. Uematsu, S., Matsumoto, M., Takeda, K., Akira, S. (2002) Lipopolysaccharide-dependent prostaglandin E(2) production is regulated by the glutathione-dependent prostaglandin E(2) synthase gene induced by the Toll-like receptor 4/MyD88/NF-IL6 pathway J. Immunol. 168,5811-5816[Abstract/Free Full Text]
  12. Stichtenoth, D. O., Thoren, S., Bian, H., Peters-Golden, M., Jakobsson, P. J., Crofford, L. J. (2001) Microsomal prostaglandin E synthase is regulated by proinflammatory cytokines and glucocorticoids in primary rheumatoid synovial cells J. Immunol. 167,469-474[Abstract/Free Full Text]
  13. Lazarus, M., Kubata, B. K., Eguchi, N., Fujitani, Y., Urade, Y., Hayaishi, O. (2002) Biochemical characterization of mouse microsomal prostaglandin E synthase-1 and its colocalization with cyclooxygenase-2 in peritoneal macrophages Arch. Biochem. Biophys. 397,336-341[CrossRef][Medline]
  14. Trebino, C. E., Stock, J. L., Gibbons, C. P., Naiman, B. M., Wachtmann, T. S., Umland, J. P., Pandher, K., Lapointe, J. M., Saha, S., Roach, M. L., et al (2003) Impaired inflammatory and pain responses in mice lacking an inducible prostaglandin E synthase Proc. Natl. Acad. Sci. USA 100,9044-9049[Abstract/Free Full Text]
  15. Engblom, D., Saha, S., Engstrom, L., Westman, M., Audoly, L. P., Jakobsson, P. J., Blomqvist, A. (2003) Microsomal prostaglandin E synthase-1 is the central switch during immune-induced pyresis Nat. Neurosci. 6,1137-1138[CrossRef][Medline]
  16. Saha, S., Engstrom, L., Mackerlova, L., Jakobsson, P. J., Blomqvist, A. (2005) Impaired febrile responses to immune challenge in mice deficient in microsomal prostaglandin E synthase-1 Am. J. Physiol. Regul. Integr. Comp. Physiol. 288,R1100-R1107[Abstract/Free Full Text]
  17. Fitzgerald, G. A. (2004) Coxibs and cardiovascular disease N. Engl. J. Med. 351,1709-1711[Free Full Text]
  18. Gordon, S. (2003) Alternative activation of macrophages Nat. Rev. Immunol. 3,23-35[CrossRef][Medline]
  19. Mantovani, A., Sica, A., Sozzani, S., Allavena, P., Vecchi, A., Locati, M. (2004) The chemokine system in diverse forms of macrophage activation and polarization Trends Immunol. 25,677-686[CrossRef][Medline]
  20. Mantovani, A., Sozzani, S., Locati, M., Allavena, P., Sica, A. (2002) Macrophage polarization: tumor-associated macrophages as a paradigm for polarized M2 mononuclear phagocytes Trends Immunol. 23,549-555[CrossRef][Medline]
  21. Goerdt, S., Orfanos, C. E. (1999) Other functions, other genes: alternative activation of antigen-presenting cells Immunity 10,137-142[CrossRef][Medline]
  22. Scapini, P., Carletto, A., Nardelli, B., Calzetti, F., Roschke, V., Merigo, F., Tamassia, N., Pieropan, S., Biasi, D., Sbarbati, A., Sozzani, S., Bambara, L., Cassatella, M. A. (2005) Proinflammatory mediators elicit secretion of the intracellular B-lymphocyte stimulator pool (BLyS) that is stored in activated neutrophils: implications for inflammatory diseases Blood 105,830-837
  23. Cassatella, M. A., Huber, V., Calzetti, F., Margotto, D., Tamassia, N., Peri, G., Mantovani, A., Rivoltini, L., Tecchio, C. (2006) Interferon-activated neutrophils store a TNF-related apoptosis-inducing ligand (TRAIL/Apo-2 ligand) intracellular pool that is readily mobilizable following exposure to proinflammatory mediators J. Leukoc. Biol. 79,123-132[Abstract/Free Full Text]
  24. Megiovanni, A. M., Sanchez, F., Robledo-Sarmiento, M., Morel, C., Gluckman, J. C., Boudaly, S. (2006) Polymorphonuclear neutrophils deliver activation signals and antigenic molecules to dendritic cells: a new link between leukocytes upstream of T lymphocytes J. Leukoc. Biol. 79,977-988[Abstract/Free Full Text]
  25. Legler, D. F., Krause, P., Scandella, E., Singer, E., Groettrup, M. (2006) Prostaglandin E2 is generally required for human dendritic cell migration and exerts its effect via EP2 and EP4 receptors J. Immunol. 176,966-973[Abstract/Free Full Text]
  26. Randolph, G. J., Sanchez-Schmitz, G., Angeli, V. (2005) Factors and signals that govern the migration of dendritic cells via lymphatics: recent advances Springer Semin. Immunopathol. 26,273-287[CrossRef][Medline]
  27. Scandella, E., Men, Y., Gillessen, S., Forster, R., Groettrup, M. (2002) Prostaglandin E2 is a key factor for CCR7 surface expression and migration of monocyte-derived dendritic cells Blood 100,1354-1361[Abstract/Free Full Text]
  28. Bosisio, D., Polentarutti, N., Sironi, M., Bernasconi, S., Miyake, K., Webb, G. R., Martin, M. U., Mantovani, A., Muzio, M. (2002) Stimulation of Toll-like receptor 4 expression in human mononuclear phagocytes by interferon-{gamma}: a molecular basis for priming and synergism with bacterial lipopolysaccharide Blood 99,3427-3431[Abstract/Free Full Text]
  29. Allavena, P., Piemonti, L., Longoni, D., Bernasconi, S., Stoppacciaro, A., Ruco, L., Mantovani, A. (1998) IL-10 prevents the differentiation of monocytes to dendritic cells but promotes their maturation to macrophages Eur. J. Immunol. 28,359-369[CrossRef][Medline]
  30. Polentarutti, N., Rol, G. P., Muzio, M., Bosisio, D., Camnasio, M., Riva, F., Zoja, C., Benigni, A., Tomasoni, S., Vecchi, A., Garlanda, C., Mantovani, A. (2003) Unique pattern of expression and inhibition of IL-1 signaling by the IL-1 receptor family member TIR8/SIGIRR Eur. Cytokine Netw. 14,211-218[Medline]
  31. Hla, T., Neilson, K. (1992) Human cyclooxygenase-2 cDNA Proc. Natl. Acad. Sci. USA 89,7384-7388[Abstract/Free Full Text]
  32. Scapini, P., Lapinet-Vera, J. A., Gasperini, S., Calzetti, F., Bazzoni, F., Cassatella, M. A. (2000) The neutrophil as a cellular source of chemokines Immunol. Rev. 177,195-203[CrossRef][Medline]
  33. Tamassia, N., Le Moigne, V., Calzetti, F., Donini, M., Gasperini, S., Ear, T., Cloutier, A., Martinez, F. O., Fabbri, M., Locati, M., Mantovani, A., McDonald, P. P., Cassatella, M. A. (2007) The MYD88-independent pathway is not mobilized in human neutrophils stimulated via TLR4 J. Immunol. 178,7344-7356[Abstract/Free Full Text]
  34. Randolph, G. J., Angeli, V., Swartz, M. A. (2005) Dendritic-cell trafficking to lymph nodes through lymphatic vessels Nat. Rev. Immunol. 5,617-628[CrossRef][Medline]
  35. Riboldi, E., Musso, T., Moroni, E., Urbinati, C., Bernasconi, S., Rusnati, M., Adorini, L., Presta, M., Sozzani, S. (2005) Cutting edge: proangiogenic properties of alternatively activated dendritic cells J. Immunol. 175,2788-2792[Abstract/Free Full Text]
  36. Luft, T., Jefford, M., Luetjens, P., Toy, T., Hochrein, H., Masterman, K. A., Maliszewski, C., Shortman, K., Cebon, J., Maraskovsky, E. (2002) Functionally distinct dendritic cell (DC) populations induced by physiologic stimuli: prostaglandin E(2) regulates the migratory capacity of specific DC subsets Blood 100,1362-1372[Abstract/Free Full Text]
  37. Trebino, C. E., Eskra, J. D., Wachtmann, T. S., Perez, J. R., Carty, T. J., Audoly, L. P. (2005) Redirection of eicosanoid metabolism in mPGES-1-deficient macrophages J. Biol. Chem. 280,16579-16585[Abstract/Free Full Text]
  38. Mantovani, A., Sica, A., Locati, M. (2005) Macrophage polarization comes of age Immunity 23,344-346[CrossRef][Medline]
  39. Hamilton, T. A., Ohmori, Y., Tebo, J. (2002) Regulation of chemokine expression by antiinflammatory cytokines Immunol. Res. 25,229-245[CrossRef][Medline]
  40. Cassatella, M. A. (1999) Neutrophil-derived proteins: selling cytokines by the pound Adv. Immunol. 73,369-509[Medline]
  41. Nathan, C. (2006) Neutrophils and immunity: challenges and opportunities Nat. Rev. Immunol. 6,173-182[CrossRef][Medline]



This article has been cited by other articles:


Home page
 CirculationHome page
N. Degousee, S. Fazel, D. Angoulvant, E. Stefanski, S.-C. Pawelzik, M. Korotkova, S. Arab, P. Liu, T. F. Lindsay, S. Zhuo, et al.
Microsomal Prostaglandin E2 Synthase-1 Deletion Leads to Adverse Left Ventricular Remodeling After Myocardial Infarction
Circulation, April 1, 2008; 117(13): 1701 - 1710.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
jlb.0906576v1
82/2/320    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Mosca, M.
Right arrow Articles by Mantovani, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Mosca, M.
Right arrow Articles by Mantovani, A.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS