Division of Medical Intensive Care, Department of Internal Medicine, University Hospital of Geneva, 1211 Geneva 14, Switzerland
![]() |
ABSTRACT |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
In addition
to their well-studied bronchodilatory and cardiotonic effects,
-adrenergic agonists carry anti-inflammatory properties by
inhibiting cytokine production by human mononuclear cells. In a model
of human promonocytic THP-1 cells stimulated with lipopolysaccharide
(LPS), we showed that
-agonists inhibited tumor necrosis factor-
and interleukin-8 production predominantly via the
2-adrenergic receptor through the generation of cAMP and
activation of protein kinase A. This effect was reproduced by other
cAMP-elevating agents such as prostaglandins and cAMP analogs.
Activation and nuclear translocation of the transcription factor
nuclear factor-
B induced by LPS were inhibited with treatment with
-agonists, an effect that was prominent at late time points (>1 h).
Although the initial I
B-
degradation induced by LPS was minimally
affected by
-agonists, the latter induced a marked rebound of the
cytosolic I
B-
levels at later time points (>1 h), accompanied by
an increased I
B-
cytoplasmic half-life. This potentially accounts
for the observed nuclear factor-
B sequestration in the cytoplasmic
compartment. We postulate that the anti-inflammatory effects of
-agonists reside in their capacity to increase cytoplasmic concentrations of I
B-
, possibly by decreasing its degradation.
lipopolysaccharide; nuclear factor-B; I
B; adenosine
3',5'-cyclic monophosphate
![]() |
INTRODUCTION |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
-ADRENERGIC
AGONISTS are utilized in a variety of clinical situations, mostly
for their bronchodilating and cardiotonic effects. It has been
recognized that these pharmacological agents modulate the production of
inflammatory mediators. It was, for example, shown that catecholamines
could inhibit tumor necrosis factor (TNF)-
, interleukin (IL)-1, and
IL-6 production by human mononuclear cells (16, 35, 42).
It has been postulated that the generation of cAMP by these agents was
necessary and that the regulation of this effect was at the level of
inflammatory gene transcription (37-39).
Nuclear factor (NF)-B is a transcription factor that has been
implicated in control of the expression of numerous inflammatory genes
including TNF-
and IL-8 (7). NF-
B is sequestered in an inactive form in the cytoplasm by its natural inhibitor, I
B-
. I
B-
phosphorylation and degradation induces the nuclear
translocation of NF-
B and the binding of the protein to specific
responding elements in the promoter regions of inflammatory genes
(6). Several studies (1, 3, 33, 47) indicated
that the regulation of the activation of this transcription factor is
implicated in the anti-inflammatory or immunosuppressive effects of
agents such as glucocorticoids, transforming growth factor-
1, and
aspirin. We have therefore investigated whether the NF-
B pathway is
implicated in the anti-inflammatory effects induced by
-agonists. In
a model of human monocytic cells (THP-1 cells) stimulated with
endotoxin, we found that the
2-adrenergic receptor was
primarily implicated in the inhibition of IL-8 production observed with
-agonists. This inhibitory effect was cAMP- and protein kinase (PK)
A-dependent and resided in the capacity of
-agonists to block the
NF-
B pathway. We show here evidence that
-agonists modulate
lipopolysaccharide (LPS) responses by inducing a marked increase of
cytoplasmic I
B-
concentration in the presence of LPS, an effect
that was observed only at late time points (>1 h).
![]() |
MATERIALS AND METHODS |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Cell culture and stimulation.
Human promonocytic THP-1 cells (American Type Culture
Collection) were maintained in RPMI 1640 medium containing 10%
fetal bovine serum (FBS), 2 mM L-glutamine, and antibiotics
(all from Life Technologies, Paisley, UK). THP-1 cells were
differentiated for 3 days with 107 M
1,25-dihydroxyvitamin D3 (Hoffmann La Roche, Basel,
Switzerland) (43). The cells were washed and distributed
into sterile microtiter plates (Costar, Corning, NY) at a concentration
of 100,000 cells/well in RPMI 1640 medium containing 2% FBS. In some
experiments, 1,25-dihydroxyvitamin D3-differentiated THP-1
cells were substituted with undifferentiated THP-1 cells transfected
with CD14 (31). The cells were stimulated with nanomolar
concentrations of Escherichia coli 0111:B4 LPS (List,
Campbell, CA) for 8 h (unless indicated otherwise) at 37°C in
the presence and absence of
-adrenergic agonists and antagonists. The following pharmacological agents were tested: isoproterenol (IMS,
South El Monte, CA), albuterol (Glaxo Wellcome, Stevenage, UK),
epinephrine (Sintetica, Mendrisio, Switzerland), norepinephrine (Aventis, Frankfurt, Germany), propranolol (Zeneca, Blackley, UK),
metoprolol (Novartis, Basel, Switzerland), esmolol (Gensia, Bracknel,
UK), phentolamine (Novartis), and iloprost (Ilomedin, Schering, Berlin,
Germany). In most experiments, isoproterenol, a
1- and
2-adrenergic agonist, was used as a prototypic
-adrenergic agonist to inhibit IL-8 production in THP-1 cells. IL-8
and TNF-
concentrations were measured in conditioned supernatants
with a sandwich ELISA with paired monoclonal antibodies available
commercially (Endogen, Cambridge, MA) as described elsewhere
(29).
Preparation of nuclear extracts and electrophoretic mobility
shift assay.
1,25-Dihydroxyvitamin D3-differentiated THP-1 cells
(7.5 × 106) were stimulated with 10 ng/ml of LPS in
RPMI 1640 medium with 2% FBS for various times. After stimulation, the
cells were rapidly chilled on ice, washed twice with ice-cold PBS, pH
7.4. Nuclear extracts were prepared as described elsewhere
(28). Nuclear proteins were used for electrophoretic
mobility shift assay. Twenty to fifty femtomoles of
32P-labeled NF-B double-stranded oligonucleotide probe
(30,000-50,000 counts/min; 5'-AGT TGA GGG GAC TTT CCC AGG-3';
Promega, Madison, WI) were added to the nuclear proteins (5-8
µg) in a binding buffer containing 5 mM HEPES, pH 8.5, 5 mM
MgCl2, 50 mM dithiothreitol, 0.4 mg/ml of poly(dI-dC)
(Amersham Pharmacia Biotech, Uppsala, Sweden), 0.1 mg/ml of sonicated
double-stranded salmon sperm DNA (Sigma), and 10% glycerol and
incubated for 10 min at room temperature. Samples were migrated on a
nondenaturing 5% acrylamide gel made in Tris-glycine-EDTA buffer. Gels
were transferred onto Whatman paper, dried, and subjected to autoradiography.
Detection of IB-
protein by Western blot.
After LPS stimulation in the presence and absence of
-agonists,
THP-1 cells were lysed in 10 mM HEPES, pH 7.9, 0.1 mM EDTA, 0.1 mM
EGTA, 1 mM dithiothreitol, and 1 mM phenylmethylsulfonyl fluoride. In
some experiments, the cells were pretreated for 30 min with the PKA
inhibitor H-89. In one experiment, isoproterenol was substituted for
PGE2, another cAMP-increasing agent. Ten micrograms of
cytoplasmic protein extracts were separated by SDS-PAGE (10% acrylamide-bis-acrylamide gel) and electrotransferred onto a
nitrocellulose membrane (Bio-Rad, Hercules, CA). I
B-
was detected
with a rabbit polyclonal anti-human I
B-
antibody (Santa
Cruz Biotechnology, Santa Cruz, CA), a mouse anti-rabbit horseradish
peroxidase-conjugated secondary antibody (Jackson ImmunoResearch, West
Grove, PA), and enhanced chemiluminescence (Amersham Pharmacia). In one
experiment, the cells were treated with 10 µg/ml of cycloheximide
(Sigma) 3 h after LPS treatment (32). Nuclear
extracts were then prepared after various incubation times as described
in Preparation of nuclear extracts and electrophoretic
mobility shift assay. Quantification of I
B-
levels
was done with densitometry of the I
B-
bands with a Molecular
Dynamics densitometer and ImageQuant software (Sunnyvale, CA).
![]() |
RESULTS |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
We used 1,25-dihydroxyvitamin D3-differentiated THP-1
cells stimulated by bacterial endotoxin as a model for
monocyte/macrophage activation (4, 30, 31). The
concentration-dependent effects of -agonists on LPS-induced IL-8
production by differentiated THP-1 cells are shown in Fig.
1A. Results are expressed as a
percentage of inhibition relative to the activation induced by LPS
alone. All
-agonists inhibited production of IL-8 at concentrations as low as 10
9 M and showed similar affinities. Fenoterol,
albuterol, isoproterenol, and epinephrine had EC50 values
of 3, 9, 13, and 15 nM, respectively. Norepinephrine was slightly less
potent than the other agonists, with an EC50 value of 38 nM. Fenoterol, epinephrine, isoproterenol, and norepinephrine showed
similar efficacies, with maximal inhibition levels of 65, 68, 71, and
73%, respectively. The efficacy of albuterol was found to be
consistently less than that of other
-agonists in inhibiting
LPS-induced IL-8 production, with a maximal inhibition level of ~ 25%. This may reflect a partial agonistic activity of this
compound as previously reported by others (9, 14). Similar
results were obtained with
-agonists in undifferentiated THP-1 cells
transfected with CD14 (IL-8 production). The pharmacological activity
of isoproterenol was independent of the LPS concentrations used to
activate THP-1 cells (tested from 1 ng/ml to 10 µg/ml). This effect
was not restricted to the production of IL-8. We found that TNF-
production by THP-1 cells was inhibited to a similar extent (Fig.
1B). CD14 surface expression, determined by
fluorescence-activated cell sorter analysis, was not influenced by
treatment with LPS and
-agonists (data not shown). In all
experiments described in MATERIALS AND METHODS, the cells
were found fully viable by the cell viability MTT assay
(12).
|
We next pharmacologically characterized the -adrenergic receptor
involved in these effects by measuring the potencies of several
-adrenergic antagonists (Fig. 2). The
results are expressed as a percentage of the LPS response.
Isoproterenol decreased the response of LPS by 69%. The addition of
10
7 M metoprolol, a selective
1-antagonist, practically unaltered the effect of
isoproterenol. When added at concentrations
10
6
M, the LPS response was restored. Similar results were obtained with
another specific
1-antagonist, esmolol (data not shown). ICI-118551, a selective
2-antagonist, and propranolol, a
nonselective
1- and
2-antagonist, showed
the highest potency to interfere with the agonistic (anti-inflammatory)
activity of isoproterenol. ICI-118551 and propranolol at concentrations
as low as 10
8 M partially inhibited and at
concentrations
10
6 M completely inhibited the
effects of isoproterenol. Both were markedly more potent than the
1-antagonist metoprolol. An
-antagonist, phentolamine, did not modify the
-agonistic effect of isoproterenol (data not shown).
|
To determine whether the inhibitory effect of isoproterenol was cAMP
dependent, we studied the effect of other cAMP-elevating agents, a cAMP
analog, and a PKA inhibitor. PGE2 and iloprost (a
prostacyclin analog) are two cAMP-elevating agents in monocytes. Both
inhibited IL-8 production induced by 10 ng/ml of LPS, with potencies of
0.3 and 0.9 nM for PGE2 and iloprost, respectively. However, these mediators showed lower efficacies than the -agonists (PGE2, 43%; iloprost, 51%). The plasma membrane-permeable
cAMP analog dibutyryl cAMP decreased LPS-induced IL-8 release to the levels observed with isoproterenol. A concentration-dependent effect of
dibutyryl cAMP was observed, with a maximal inhibitory response of 60%
obtained with a 0.1 mM concentration. The PKA inhibitor H-89 abrogated
the pharmacological activity of isoproterenol at a 10 µM
concentration. Together, these results indicate that isoproterenol
acted as an "anti-inflammatory" agent principally through its
interaction with a
2-adrenergic receptor at the
surface of THP-1 cells, leading to the generation of cAMP and
activation of PKA.
Because inhibitory effects of -agonists could be at the level of
protein secretion per se (44), we measured the intra- and
extracellular concentrations of IL-8 in THP-1 cells stimulated with LPS
in the presence and absence of
-agonists. IL-8 production was
increased in both intra- and extracellular compartments in response to
LPS. Isoproterenol blocked both intra- and extracellular IL-8 to
similar levels, an effect that could be reversed by propranolol (Table
1). These experiments suggest that the
inhibitory effect of isoproterenol takes place before the secretion
process.
|
We next addressed whether isoproterenol influenced the activation and
nuclear translocation of NF-B because this transcription factor has
been shown to be of importance for the activation of proinflammatory
mediators such as IL-8 and TNF-
(20, 36). NF-
B was
found to be activated in nuclear extracts from THP-1 cells treated with
LPS but not in those cells treated with medium only (Fig.
3). The NF-
B-oligonucleotide bands
from electrophoretic mobility shift assay gels were quantified by
densitometry in three separate experiments. The addition of
isoproterenol did not modify NF-
B activation by LPS at 20 and 60 min
but significantly decreased the NF-
B signal at 120 and 180 min
(results for 20 and 180 min shown in Fig. 3). The loading of the
nuclear protein-oligoprobe mixture was similar in all lanes (data not
shown).
|
We next postulated that the inhibition of NF-B activation and
nuclear translocation induced by
-agonists was at the level of the
regulation by its natural inhibitor I
B-
. Figure
4A shows, with a Western blot
technique on cytosolic THP-1 cell extracts, that treatment with LPS
resulted in the early disappearance (5-30 min) of I
B-
due to
its degradation. Repeated experiments (n = 3) indicated
that isoproterenol induced a significantly more rapid degradation of
I
B-
(results for 1 representative experiment shown in Fig.
4A). This was followed by the reappearance of I
B-
after ~1 h due to its resynthesis. Isoproterenol dramatically and
significantly increased the cytoplasmic concentration of I
B-
at
late time points (>1 h; P < 0.01; 1 representative
experiment shown in Fig. 4B and pooled results from 5 independent experiments shown in Fig. 4C). This effect was
particularly marked at 3 h. This effect was not observed in the
absence of LPS treatment; i.e., isoproterenol did not increase the
cytoplasmic I
B-
levels by itself (1 representative experiment
shown in Fig. 4D). This was confirmed in three separate
experiments (data not shown). Because modulation of the cAMP-PKA
pathway modified IL-8 secretion in THP-1 cells treated with LPS, we
next addressed whether another cAMP-increasing agent, PGE2,
could also influence I
B-
cytosolic concentrations. As shown in
Fig. 5A, PGE2 had
a similar inhibitory effect compared with isoproterenol. This was a
consistent finding observed in four separate experiments (Fig.
5B). Increased I
B-
cytoplasmic levels induced by
isoproterenol at 150 min could be blocked by the addition of the PKA
inhibitor H-89 (Fig. 5B). These results strongly suggested
that this effect was not specific for
-agonists but was observed
with other cAMP-increasing agents such as PGE2 and that a
cAMP-PKA-dependent pathway was directly involved in the modulation of
I
B-
in response to these pharmacological agents.
|
|
The marked increase in cytoplasmic levels of IB-
protein induced
by isoproterenol may result from an increase in I
B-
synthesis or
a decrease in its degradation. To address this, we performed an
experiment in which we tested the stability of the I
B-
protein in
the cytoplasm after stimulation with LPS in the presence and absence of
isoproterenol. The cells were stimulated for 3 h with LPS in the
presence and absence of isoproterenol. The protein synthesis inhibitor
cycloheximide (10 µg/ml) was then added, and cytoplasmic I
B-
levels were measured with Western blots at different times over the
next 2 h. Figure 6 shows that after
LPS stimulation, I
B-
levels remained high, with greater stability
in the presence of the
-agonist than that measured in its absence
(half life ~60 and 20 min, respectively).
|
![]() |
DISCUSSION |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Here we show that -adrenergic agonists inhibit the production
of IL-8 by human promonocytic THP-1 cells in response to LPS. The
inhibitory effect of
-adrenergic agonists on LPS-induced IL-8
production was predominantly mediated by their interaction with the
2-adrenergic receptor. This conclusion was based on experiments with
-agonists of different selectivities for the
1- and
2-adrenergic receptors and the use
of selective and nonselective
-blockers. We found that albuterol and
fenoterol, selective
2-agonists, had similar potencies
compared with epinephrine and isoproterenol in inhibiting LPS-dependent
mononuclear cell activation. In contrast, norepinephrine, known for its
greater avidity for the
1-adrenergic receptor, was three
times less potent than the other agonists tested. In addition, the
compound ICI-118551, a selective
2-blocker, and
propranolol, a nonselective
1- and
2-antagonist, were much more efficient in reverting the
-agonistic effect than the selective
1-agonist
metoprolol. This is in accordance with the work of Sekut et al.
(34). These authors reported the inhibitory effect of the
2-selective agonists albuterol and salmeterol on
LPS-induced TNF-
production by these cells, an effect that was
blocked by the specific
2-antagonist oxprenolol
(34). In addition, the
2-adrenoceptor was
previously found to be the adrenoceptor prominently expressed and
functional in monocyte/macrophage-like cells (8, 17, 18, 21,
25). In contrast, Talmadge et al. (39) found that
in undifferentiated promonocytic THP-1 cells, the
1-adrenoceptor mediated the inhibition of LPS-induced
TNF synthesis (39). This is probably due to a different
1- to
2-adrenoceptor ratio of surface
expression in undifferentiated THP-1 cells as well as a different
readout (mRNA vs. protein). The cell type utilized in our study
(macrophages) as well as the agonist and antagonist potency orders
indicate that participation of the
3-adrenoceptor is unlikely.
The observed decreased IL-8 production by -agonists was dependent on
the generation of cAMP and on the activation of PKA. Indeed, the cAMP
analog dibutyryl cAMP and other cAMP-elevating agents such as
PGE2 and iloprost reproduced the effects observed with
-agonists. H-89, a PKA inhibitor, completely reversed the anti-inflammatory effects of isoproterenol. These findings are in agreement with several studies (2, 10, 37, 38) that tested the effects of cAMP-elevating agents. Whether downstream effectors of this pathway [e.g., cAMP response element binding protein
(CREB) transcription factor] are implicated remains to be determined.
Because NF-B has been implicated in the transcriptional regulation
of many inflammatory genes including TNF-
(46) and IL-8
(13, 20), we addressed whether
-agonists would
interfere with this pathway. We found that this effect was likely due
to decreased activation and nuclear translocation of NF-
B, and this was observed only after >1 h of LPS stimulation. At earlier time points, the drug did not influence the level of NF-
B activation. We
hypothesized that this was due to a secondary increase of cytoplasmic concentrations of its natural inhibitor I
B-
, a mode of action already described for other anti-inflammatory agents (3,
33). Cytoplasmic levels of I
B-
as measured by Western blot
indicated that the treatment of cells with isoproterenol did not
prevent the initial I
B-
degradation on LPS stimulation but rather
induced a subsequent marked increase in cytosolic I
B-
levels.
Even a small increase in cytosolic concentrations of I
B-
was
previously shown to negatively affect NF-
B nuclear translocation
(19). Importantly, and in contrast with the mode of action
described for glucocorticoids, an increased production of I
B-
was
not observed in cells treated only with
-agonists. The addition of a
proinflammatory stimulus such as LPS was necessary to observe this effect.
Ollivier et al. (24) previously showed that cAMP induced
by forskolin inhibited LPS-induced NF-B activation in THP-1 cells. In their study, the rate of NF-
B nuclear translocation was not affected, but it was the transcription efficiency of NF-
B at early
times (1 h) that was reduced with increased cAMP concentrations. However, these authors did not investigate the activation of NF-
B at
later time points. Our results unravel another possible mechanism, which may explain the inhibitory effect observed with
-agonists. After the initial NF-
B activation by LPS,
-agonists may induce the activation of transcription factors such as CREB, which might cooperate with NF-
B at the level of the I
B-
promoter to
increase its transcription. Such a cooperative mechanism has been
described for NF-
B and other transcription factors
(20). This could be the reason for the need of the
presence of both LPS and
-agonists to observe the increased
I
B-
cytoplasmic levels. Interestingly, recently published data
(11) indicated that a transcriptionally active
glucocorticoid receptor was translocated into the nucleus on treatment
with
2-agonists, which may also cooperate with NF-
B to increase I
B-
transcription.
Another possibility is that the regulation of IB-
by cAMP is at
the level of protein degradation as suggested by the experiment shown
in Fig. 5. Such an effect was proposed by Neumann et al. (22) in a study where forskolin increased the cytoplasmic
levels of I
B-
. It is also conceivable that
-agonists decrease
I
B-
phosphorylation and degradation through the activation of
second messengers, which will, in turn, inhibit upstream kinases
such as IL-1 receptor-associated kinase, TNF receptor-associated
kinase-6, or members of the mitogen-activated protein kinase
kinase kinase (MEKK)-1-NF-
B-inducing kinase-I
B kinase
complex involved in LPS signaling (15, 23). The delayed
appearance of I
B-
protein in the cytoplasm could also suggest
that
-agonists may induce or activate a cytosolic inhibitor of
kinases upstream of NF-
B. Candidate inhibitors are those of the
family of antiapoptotic factors. Indeed, it was recently demonstrated
that increased expression of Bcl-2 and Bcl-XL, which are
under the control of both NF-
B and CREB (40, 45),
prevented I
B-
degradation (5). In another study, it
was shown that the LPS-induced A20 protein could directly inhibit
MEKK-1 (Kravchenko VV, personal communication). It is also possible
that an anti-inflammatory cytokine such as IL-10 is produced on
-agonist treatment, which may turn down IL-8 production induced by
LPS in an autocrine fashion via an I
B-dependent mechanism (27,
41). Finally, Parry and Mackman (26) have proposed
that NF-
B inhibition by cAMP occurred at the level of the
differential binding of CREB and NF-
B to the CREB-binding protein, a
protein necessary for efficient gene transcription (26).
In conclusion, we hereby provide clues as to the mechanisms by which
cAMP-increasing agents such as -agonists exert their anti-inflammatory effects. These pharmacological agents block NF-
B
activation and nuclear translocation and, secondarily, inflammatory gene transcription by increasing I
B-
cytoplasmic concentration. Our results also make an important link between the cAMP and NF-
B pathways.
![]() |
ACKNOWLEDGEMENTS |
---|
We thank Pierre Weber (Hoffmann La Roche, Basel, Switzerland) and Ursula Lang and Alessandro Capponi (University of Geneva, Geneva, Switzerland) for the gift of precious reagents, and A. Nials, M. Skingle and T. N. C. Wells for stimulating discussions and constant support.
![]() |
FOOTNOTES |
---|
This work was supported by Swiss National Foundation for Scientific Research Grant SNF 32-50764 (to J. Pugin) and grants from the 3R and Carlos and Elise de Reuter Foundations and Glaxo Wellcome.
P. Farmer received a scholarship from the Canadian Heart and Stroke Foundation and the Fonds pour la Formation de Chercheur et l'Aide à la Recherche. J. Pugin is the recipient of a fellowship from the Prof. Dr. Max Cloëtta Foundation.
Address for reprint requests and other correspondence: J. Pugin, Division of Medical Intensive Care, Dept. of Internal Medicine, University Hospital of Geneva, 1211 Geneva 14, Switzerland (E-mail: pugin{at}cmu.unige.ch).
The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Received 28 January 2000; accepted in final form 26 April 2000.
![]() |
REFERENCES |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
1.
Arsura, M,
Wu M,
and
Sonenshein GE.
TGF beta 1 inhibits NF-kappa B/Rel activity inducing apoptosis of B cells: transcriptional activation of I kappa B alpha.
Immunity
5:
31-40,
1996[ISI][Medline].
2.
Au, BT,
Teixeira MM,
Collins PD,
and
Williams TJ.
Effect of PDE4 inhibitors on zymosan-induced IL-8 release from human neutrophils: synergism with prostanoids and salbutamol.
Br J Pharmacol
123:
1260-1266,
1998[Abstract].
3.
Auphan, N,
DiDonato JA,
Rosette C,
Helmberg A,
and
Karin M.
Immunosuppression by glucocorticoids: inhibition of NF-kappa B activity through induction of I kappa B synthesis.
Science
270:
286-290,
1995[Abstract].
4.
Auwerx, J.
The human leukemia cell line, THP-1: a multifacetted model for the study of monocyte-macrophage differentiation.
Experientia
47:
22-31,
1991[ISI][Medline].
5.
Badrichani, AZ,
Stroka DM,
Bilbao G,
Curiel DT,
Bach FH,
and
Ferran C.
Bcl-2 and Bcl-XL serve an anti-inflammatory function in endothelial cells through inhibition of NF-kappaB.
J Clin Invest
103:
543-553,
1999
6.
Baeuerle, PA,
and
Baltimore D.
Activation of DNA-binding activity in an apparently cytoplasmic precursor of the NF-kappa B transcription factor.
Cell
53:
211-217,
1988[ISI][Medline].
7.
Barnes, PJ,
and
Karin M.
Nuclear factor-kappaB: a pivotal transcription factor in chronic inflammatory diseases.
N Engl J Med
336:
1066-1071,
1997
8.
Boomershine, CS,
Lafuse WP,
and
Zwilling BS.
Beta2-adrenergic receptor stimulation inhibits nitric oxide generation by Mycobacterium avium infected macrophages.
J Neuroimmunol
101:
68-75,
1999[ISI][Medline].
9.
Bremner, P,
Siebers R,
Crane J,
Beasley R,
and
Burgess C.
Partial vs. full beta-receptor agonism. A clinical study of inhaled albuterol and fenoterol.
Chest
109:
957-962,
1996
10.
Delgado, M,
Munoz-Elias EJ,
Kan Y,
Gozes I,
Fridkin M,
Brenneman DE,
Gomariz RP,
and
Ganea D.
Vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide inhibit tumor necrosis factor alpha transcriptional activation by regulating nuclear factor-kB and cAMP response element-binding protein/c-Jun.
J Biol Chem
273:
31427-31436,
1998
11.
Eickelberg, O,
Roth M,
Lorx R,
Bruce V,
Rudiger J,
Johnson M,
and
Block LH.
Ligand-independent activation of the glucocorticoid receptor by beta2-adrenergic receptor agonists in primary human lung fibroblasts and vascular smooth muscle cells.
J Biol Chem
274:
1005-1010,
1999
12.
Ferrari, M,
Fornasiero MC,
and
Isetta AM.
MTT colorimetric assay for testing macrophage cytotoxic activity in vitro.
J Immunol Methods
131:
165-172,
1990[ISI][Medline].
13.
Ishikawa, Y,
Mukaida N,
Kuno K,
Rice N,
Okamoto S,
and
Matsushima K.
Establishment of lipopolysaccharide-dependent nuclear factor kappa B activation in a cell-free system.
J Biol Chem
270:
4158-4164,
1995
14.
January, B,
Seibold A,
Whaley B,
Hipkin RW,
Lin D,
Schonbrunn A,
Barber R,
and
Clark RB.
Beta2-adrenergic receptor desensitization, internalization, and phosphorylation in response to full and partial agonists.
J Biol Chem
272:
23871-23879,
1997
15.
Kirschning, CJ,
Wesche H,
Merrill Ayres T,
and
Rothe M.
Human toll-like receptor 2 confers responsiveness to bacterial lipopolysaccharide.
J Exp Med
188:
2091-2097,
1998
16.
Koff, WC,
Fann AV,
Dunegan MA,
and
Lachman LB.
Catecholamine-induced suppression of interleukin-1 production.
Lymphokine Res
5:
239-247,
1986[ISI][Medline].
17.
Leurs, R,
Beusenberg FD,
Bast A,
Van Amsterdam JG,
and
Timmerman H.
Identification of beta 2-adrenoceptors on guinea pig alveolar macrophages using (-)-3-[125I]iodocyanopindolol.
Inflammation
14:
421-426,
1990[ISI][Medline].
18.
Liggett, SB.
Beta-adrenoceptor-effector system of the human macrophage U937 cell line.
Eur J Pharmacol
163:
171-174,
1989[ISI][Medline].
19.
Miyamoto, S,
Chiao PJ,
and
Verma IM.
Enhanced I kappa B alpha degradation is responsible for constitutive NF- kappa B activity in mature murine B-cell lines.
Mol Cell Biol
14:
3276-3282,
1994[Abstract].
20.
Mukaida, N,
Mahe Y,
and
Matsushima K.
Cooperative interaction of nuclear factor-kappa B- and cis-regulatory enhancer binding protein-like factor binding elements in activating the interleukin-8 gene by pro-inflammatory cytokines.
J Biol Chem
265:
21128-21133,
1990
21.
Nakamura, A,
Johns EJ,
Imaizumi A,
Yanagawa Y,
and
Kohsaka T.
Modulation of interleukin-6 by beta2-adrenoceptor in endotoxin-stimulated renal macrophage cells.
Kidney Int
56:
839-849,
1999[ISI][Medline].
22.
Neumann, M,
Grieshammer T,
Chuvpilo S,
Kneitz B,
Lohoff M,
Schimpl A,
Franza BR, Jr,
and
Serfling E.
RelA/p65 is a molecular target for the immunosuppressive action of protein kinase A.
EMBO J
14:
1991-2004,
1995[Abstract].
23.
O'Connell, MA,
Bennett BL,
Mercurio F,
Manning AM,
and
Mackman N.
Role of IKK1 and IKK2 in lipopolysaccharide signaling in human monocytic cells.
J Biol Chem
273:
30410-30414,
1998
24.
Ollivier, V,
Parry GCN,
Cobb RR,
de Prost D,
and
Mackman N.
Elevated cyclic AMP inhibits NF-kappaB-mediated transcription in human monocytic cells and endothelial cells.
J Biol Chem
271:
20828-20835,
1996
25.
Panina-Bordignon, P,
Mazzeo D,
Lucia PD,
D'Ambrosio D,
Lang R,
Fabbri L,
Self C,
and
Sinigaglia F.
Beta2-agonists prevent Th1 development by selective inhibition of interleukin 12.
J Clin Invest
100:
1513-1519,
1997
26.
Parry, GC,
and
Mackman N.
Role of cyclic AMP response element-binding protein in cyclic AMP inhibition of NF-kappaB-mediated transcription.
J Immunol
159:
5450-5456,
1997[Abstract].
27.
Platzer, C,
Meisel C,
Vogt K,
Platzer M,
and
Volk HD.
Up-regulation of monocytic IL-10 by tumor necrosis factor-alpha and cAMP elevating drugs.
Int Immunol
7:
517-523,
1995[Abstract].
28.
Poussin, C,
Foti M,
Carpentier JL,
and
Pugin J.
CD14-dependent endotoxin internalization via a macropinocytic pathway.
J Biol Chem
273:
20285-20291,
1998
29.
Pugin, J,
Dunn I,
Jolliet P,
Tassaux D,
Magnenat JL,
Nicod LP,
and
Chevrolet JC.
Activation of human macrophages by mechanical ventilation in vitro.
Am J Physiol Lung Cell Mol Physiol
275:
L1040-L1050,
1998
30.
Pugin, J,
Heumann ID,
Tomasz A,
Kravchenko VV,
Akamatsu Y,
Nishijima M,
Glauser MP,
Tobias PS,
and
Ulevitch RJ.
CD14 is a pattern recognition receptor.
Immunity
1:
509-516,
1994[ISI][Medline].
31.
Pugin, J,
Kravchenko VV,
Lee JD,
Kline L,
Ulevitch RJ,
and
Tobias PS.
Cell activation mediated by glycosylphosphatidylinositol-anchored or transmembrane forms of CD14.
Infect Immun
66:
1174-1180,
1998
32.
Riddick, CA,
Serio KJ,
Hodulik CR,
Ring WL,
Regan MS,
and
Bigby TD.
TGF-beta increases leukotriene C4 synthase expression in the monocyte-like cell line, THP-1.
J Immunol
162:
1101-1107,
1999
33.
Scheinman, RI,
Cogswell PC,
Lofquist AK,
and
Baldwin AS, Jr.
Role of transcriptional activation of I kappa B alpha in mediation of immunosuppression by glucocorticoids.
Science
270:
283-286,
1995[Abstract].
34.
Sekut, L,
Champion BR,
Page K,
Menius JA, Jr,
and
Connolly KM.
Anti-inflammatory activity of salmeterol: down-regulation of cytokine production.
Clin Exp Immunol
99:
461-466,
1995[ISI][Medline].
35.
Severn, A,
Rapson NT,
Hunter CA,
and
Liew FY.
Regulation of tumor necrosis factor production by adrenaline and beta-adrenergic agonists.
J Immunol
148:
3441-3445,
1992
36.
Shakhov, AN,
Kuprash DV,
Azizov MM,
Jongeneel CV,
and
Nedospasov SA.
Structural analysis of the rabbit TNF locus, containing the genes encoding TNF-beta (lymphotoxin) and TNF-alpha (tumor necrosis factor).
Gene
95:
215-221,
1990[ISI][Medline].
37.
Spengler, RN,
Spengler ML,
Lincoln P,
Remick DG,
Strieter RM,
and
Kunkel SL.
Dynamics of dibutyryl cyclic AMP- and prostaglandin E2-mediated suppression of lipopolysaccharide-induced tumor necrosis factor alpha gene expression.
Infect Immun
57:
2837-2841,
1989[ISI][Medline].
38.
Taffet, SM,
Singhel KJ,
Overholtzer JF,
and
Shurtleff SA.
Regulation of tumor necrosis factor expression in a macrophage-like cell line by lipopolysaccharide and cyclic AMP.
Cell Immunol
120:
291-300,
1989[ISI][Medline].
39.
Talmadge, J,
Scott R,
Castelli P,
Newman-Tarr T,
and
Lee J.
Molecular pharmacology of the beta-adrenergic receptor on THP-1 cells.
Int J Immunopharmacol
15:
219-228,
1993[ISI][Medline].
40.
Tamatani, M,
Che YH,
Matsuzaki H,
Ogawa S,
Okado H,
Miyake S,
Mizuno T,
and
Tohyama M.
Tumor necrosis factor induces Bcl-2 and Bcl-x expression through NFkappaB activation in primary hippocampal neurons.
J Biol Chem
274:
8531-8538,
1999
41.
Van der Poll, T,
Coyle SM,
Barbosa K,
Braxton CC,
and
Lowry SF.
Epinephrine inhibits tumor necrosis factor-alpha and potentiates interleukin 10 production during human endotoxemia.
J Clin Invest
97:
713-719,
1996
42.
Van der Poll, T,
Jansen J,
Endert E,
Sauerwein HP,
and
van Deventer SJ.
Noradrenaline inhibits lipopolysaccharide-induced tumor necrosis factor and interleukin 6 production in human whole blood.
Infect Immun
62:
2046-2050,
1994[Abstract].
43.
Vey, E,
Zhang JH,
and
Dayer JM.
IFN-gamma and 1,25(OH)2D3 induce on THP-1 cells distinct patterns of cell surface antigen expression, cytokine production, and responsiveness to contact with activated T cells.
J Immunol
149:
2040-2046,
1992
44.
Viherluoto, J,
Palkama T,
Silvennoinen O,
and
Hurme M.
Cyclic adenosine monophosphate decreases the secretion, but not the cell-associated levels, of interleukin-1 beta in lipopolysaccharide-activated human monocytes.
Scand J Immunol
34:
121-125,
1991[ISI][Medline].
45.
Wilson, BE,
Mochon E,
and
Boxer LM.
Induction of bcl-2 expression by phosphorylated CREB proteins during B-cell activation and rescue from apoptosis.
Mol Cell Biol
16:
5546-5556,
1996[Abstract].
46.
Yao, J,
Mackman N,
Edgington TS,
and
Fan ST.
Lipopolysaccharide induction of the tumor necrosis factor-alpha promoter in human monocytic cells. Regulation by Egr-1, c-Jun, and NF- kappaB transcription factors.
J Biol Chem
272:
17795-17801,
1997
47.
Yin, MJ,
Yamamoto Y,
and
Gaynor RB.
The anti-inflammatory agents aspirin and salicylate inhibit the activity of I-kappaB kinase-beta.
Nature
396:
77-80,
1998[ISI][Medline].