| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
RI-Mediated TNF-
Production and Stimulates MAP Kinases via a Different Pathway in MC/9 Mast Cells1
*
Division of Basic Sciences, Department of Pediatrics,
Program in Molecular Signal Transduction, and
Division of Immunology, Department of Medicine, National Jewish Medical and Research Center, Denver, CO 80206
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
following the aggregation of
high affinity Fc receptors for IgE (Fc
RI). Ligation of SCFR or
FcRI on MC/9 cells resulted in the activation of all three MAP
kinase family members, extracellular signal-regulated kinases, c-Jun
amino-terminal kinase (JNK), and p38. Stem cell factor (SCF)-induced
activation of JNK and p38 was insensitive to wortmannin, cyclosporin A,
and FK506 whereas activation of these kinases through FcRI was
sensitive to these drugs. Coligation of SCFR augmented FcRI-mediated
activation of MAP kinases, especially JNK activation, and SCF augmented
FcRI-mediated TNF- production in MC/9 cells, although SCF alone
did not induce TNF- production. This augmentation by SCF was
regulated at the level of transcription, at least in part, since the
promoter activity of TNF- was enhanced following addition of SCF.
These results demonstrate that SCF can augment FcRI-mediated JNK
activation and cytokine gene transcription but via pathways that are
regulated differently than the ones activated through
FcRI. |
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
RI)3 triggers secretion
of a variety of preformed chemical mediators, such as histamine, and
newly synthesized lipid mediators. In addition to these biologically
active substances, mast cells secrete cytokines such as IL-2, IL-3,
IL-4, IL-5, IL-6, TNF-, and granulocyte-macrophage-CSF (1, 2, 3, 4). It
has become increasingly apparent that mast cells influence allergic
inflammatory responses through the release of a number of these
cytokines. Among these cytokines, TNF- is synthesized and secreted
from both murine and human mast cells and mast cell lines (5, 6, 7). The
control of mast cell cytokine production may be an important
therapeutic target for allergic diseases.
Aggregation of the FcRI activates a number of intracellular signal
transduction pathways including the tyrosine phosphorylation of
cellular proteins, phosphoinositide hydrolysis, an increase in
intracellular calcium, and protein kinase C activation. In RBL-2H3
cells, cross-linking of FcRI leads to the activation of
mitogen-activated protein (MAP) kinases (8, 9, 10). However, the signal
transduction pathways through FcRI involved in cytokine production
in mast cells are still obscure because the downstream consequences of
the early activation events and the activation of transcriptional
factors following FcRI aggregation are not well defined. We recently
showed that aggregation of FcRI activates the three MAP kinase
family members, c-Jun amino-terminal kinase (JNK), p38, and
extracellular signal-regulated kinases (ERK), and that
phosphatidylinositol 3-kinase (PI3-kinase) and MEK kinases play
an important role in TNF- production of Ag-stimulated mast cells,
mainly through JNK activation (11, 12).
Another unique receptor on mast cells is SCFR/Kit, a transmembrane tyrosine kinase receptor which is homologous to receptors for platelet-derived growth factor and CSF-1 (13, 14). Stem cell factor (SCF), the cognate ligand for SCFR, also known as c-kit ligand, promotes the growth, differentiation, and activation of mast cells (15, 16).
Here, we show that SCF also activates the three members of the
mitogen-activated protein (MAP) kinase family, JNK, p38, and ERK, in a
murine mast cell line, MC/9. Notably, and in contrast to signaling
through FcRI, SCF-induced activation of these kinases is resistant
to the PI3-kinase inhibitor, wortmannin, as well as the
immunosuppressants, cyclosporin A (CsA) and FK506. Further, addition of
SCF enhances FcRI-mediated TNF- production, and this augmentation
is at the level of TNF- gene transcription.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
The MC/9 mouse mast cell clone was obtained from the American
Type Culture Collection (Rockville, MD). The cells were maintained by
passage in DMEM (Life Technologies, Grand Island, NY) supplemented with
50 mM 2-ME (Life Technologies), 10% fetal bovine serum (Summit
Biotechnology, Fort Collins, CO), and 5% conditioned medium (rat
growth factor obtained from Collaborative Biomedical, Bedford, MA). SCF
was obtained from medium conditioned by Chinese hamster ovary cells
transfected with SCF expression vector (kindly provided by Genetics
Institute, Cambridge, MA). Recombinant mouse SCF was purchased from R&D
Systems (Minneapolis, MN). Bovine myelin basic protein (MBP) was
obtained from Upstate Biotechnology (Lake Placid, NY). Goat polyclonal
anti-ERK2 (C-14) Ab and anti-Akt1 (C-20) Ab were purchased from
Santa Cruz Biotechnology (Santa Cruz, CA). Recombinant protein G
agarose was purchased from Zymed Laboratories (San Francisco, CA). OVA
(grade V) was obtained from Sigma (St. Louis, MO). Wortmannin and
rapamycin (RAP) were purchased from Calbiochem (San Diego, CA).
Wortmannin was prepared as a 10 mM stock solution dissolved in DMSO.
The final concentration of DMSO was adjusted to 0.01%. CsA and
cyclosporin H were obtained from Sandoz Pharma (Basel, Switzerland).
FK506 was from Fujisawa Pharmaceutical (Osaka, Japan).
Recombinant mouse TNF-, purified rat anti-mouse TNF-
mAb (ELISA capture), and biotinylated rabbit anti-mouse TNF-
polyclonal Ab (ELISA detection) were purchased from PharMingen (San
Diego, CA). DEAE-dextran was obtained from Pharmacia Biotech
(Uppsala, Sweden). The protein kinase A inhibitor
(TTYADFIASGRTGRRNAIHD) and Crosstide (GRPRTSSFAEG) were made in the
Molecular Resource Center, National Jewish Medical and Research Center
(Denver, CO).
Passive sensitization and stimulation of MC/9 cells
MC/9 cells were incubated with 500 ng/ml anti-OVA IgE (17) for 2 h. The cells were washed with medium three times and cultured with fresh medium for an additional 2 h. OVA dissolved in PBS was added for the stimulation, and PBS was used as a control vehicle. In some experiments, MC/9 cells were incubated with fresh medium for 2 h, and SCF was added to the medium as 1% final volume.
Kinase assay of Akt1
Cells (3 x 106) were lysed in a buffer (10 mM
K2PO4, pH 7.4, 0.1% Nonidet P-40, 1 mM
EDTA, 5 mM EGTA, 10 mM MgCl2, 20 mM ß-glycerophosphate,
0.5 mM Na3VO4, 2 mM DTT, 1 mM PMSF, 10 µg/ml
aprotinin, 5 µg/ml leupeptin). The lysates were incubated with 2
mg/ml goat anti-Akt1 Ab for 2 h at 4°C. Recombinant protein
G agarose was added to the lysates and incubated for an additional
1 h at 4°C. The immunoprecipitates were washed twice with lysis
buffer and once with kinase buffer (20 mM Tris-HCl, pH 7.5, 10 mM
MgCl2, 0.1 mg/ml BSA, 1 mM DTT). After the final wash, 50
ml of a kinase assay buffer containing 5 µCi of
[
-32P]ATP (DuPont, Wilmington, DE), 100 µM cold ATP,
1 µg/ml protein kinase A inhibitor, and 5 µg of Crosstide (18) were
added per sample. The samples were incubated for 15 min at 30°C, and
the reaction was stopped by adding 10 µl of 0.5 M EDTA. Twenty-five
microliters of each sample were loaded on phosphocellulose paper
(Whatman, Clifton, NJ) and phosphorylation of Crosstide was determined
by liquid scintillation counting.
Other kinase assays
GST-c-Jun (1–79) fusion protein was prepared and JNK kinase
activity was measured as described previously (19). p38 MAP kinase
activity was assayed as described previously using ATF-2 as substrate
and quantified with a PhosphorImager (Molecular Dynamics, Sunnyvale,
CA) (12). In vitro kinase assay of ERK2 was conducted as described
previously (20) using MBP as substrate. TNF- was measured by ELISA
as described previously (12).
Transfection
The full length promoter of the mouse TNF- gene (21) (kindly
provided by Dr. Bruce Beutler, The University of Texas Southwestern
Medical Center, Dallas, TX) was inserted upstream of the luciferase
gene in pGL3-luciferase reporter basic vector (Promega, Madison, WI).
This plasmid, designated pGL3TNF, was used for transfection. pGL3TNF (4
µg) was transfected into MC/9 cells using the DEAE-dextran method
(19). Cells (2 x 106) were washed once with 1x TBS
(25 mM Tris, 137 mM NaCl, 5 mM KCl, 0.5 mM
Na2HPO4, 0.49 mM MgCl2, 0.68 mM
CaCl2, pH 7.5). Cells were suspended with 0.4 ml of a
mixture of 750 µg of DEAE-dextran/4 µg of DNA and incubated at room
temperature for 30 min. After a washing with 1x TBS, cells were
suspended in 10 ml of culture medium and plated on culture dishes. At
24 h after transfection, cells were passively sensitized with
anti-OVA IgE and incubated with OVA and SCF for an additional
15 h.
Luciferase assay
Cell pellets were lysed in 100 µl of a buffer containing 25 mM Tris, pH 7.8, 2 mM EDTA, 2 mM DTT, 10% glycerol, and 1% Triton X-100. Twenty microliters of the lysate were mixed with 100 µl of luciferase assay substrate containing beetle luciferin (Promega), and chemiluminescence was measured for 30 s as relative light units using a luminometer (Monolight 2010; Analytical Luminescence Laboratory, San Diego, CA). Relative light units were correlated with sample protein. To control for responsiveness of the luciferase readout, cells were transfected as a pool, passively sensitized, and then divided for specific treatments. Thus, the efficacy of pTNF Luc transfection was the same for each condition within an experiment.
Statistical analysis
Student’s t test or Welch’s t test was used for the statistical analysis. Levels of significance are indicated in the legend for each figure.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
production of Ag-stimulated mast cells
MC/9 cells sensitized with anti-OVA IgE (1 x
106 cells/ml) were incubated with OVA in the presence or
absence of 1% (v/v) SCF for 3 h. Addition of OVA (0.1–10
µg/ml) stimulated TNF- production in a dose-dependent manner (Fig. 1
A). SCF significantly
enhanced OVA-induced TNF- production although SCF alone did not
induce TNF- production. This augmentation was observed with all
concentrations of OVA. In the presence of low concentrations of OVA
(0.1 µg/ml), little TNF- production (<70 pg/106
cells) was observed, but following costimulation with SCF, TNF-
production was markedly increased (>1.7 ng/106 cells)
(Fig. 1A).
|
gene promoter activity
We monitored OVA-induced luciferase reporter gene expression in
MC/9 cells sensitized with anti-OVA IgE after transfection with
pGL3TNF (Fig. 1
B). Luciferase expression in the cells
stimulated with OVA reached maximal levels at 1 µg/ml. Addition of
SCF significantly enhanced OVA (0.1–10 µg/ml)-induced luciferase
expression whereas SCF alone induced no luciferase activation (Fig. 1B).
SCF induces JNK, p38, and ERK2 activation
Mouse recombinant SCF induced JNK activation in a dose-dependent
manner (Fig. 2A). Addition of
1% Chinese hamster ovary cell-conditioned medium stimulated JNK
activity to the same degree as 100 ng/ml recombinant mouse SCF (Fig. 2A). SCF stimulation of JNK activity was easily detected
within 5 min and reached maximal levels at 15 min (Fig. 2B).
SCF also stimulated the activation of p38 which reached maximal levels
at 1 to 5 min after the addition of SCF (Fig. 2C). It has
previously been reported that SCF stimulates the ERK pathway (32). In
Figure 2D, we confirmed that SCF stimulated ERK2 activation
which also peaked at 1 to 5 min after the addition of SCF.
|
RI and SCFR is additive for JNK activation
We previously showed that 10 µg/ml OVA induces strong activation
of MAP kinase activity and TNF- production, whereas addition of 0.1
µg/ml OVA induces marginal TNF- production in anti-OVA
IgE-sensitized MC/9 cells (12). We examined the combined effects of
SCFR and FcRI ligation on the activation of JNK, p38, and ERK2 in
MC/9 cells stimulated with 0.1 µg/ml OVA. SCF enhanced OVA (0.1
µg/ml)-stimulated JNK activity (4.5-fold increase compared with 0.1
µg/ml OVA alone) (Fig. 3, A
and D). However, SCF did not significantly enhance OVA (0.1
µg/ml)-stimulated p38 or ERK2 activity (Fig. 3, B,
C, E, and F). In the presence of
higher concentrations of OVA (10 µg/ml), SCF enhanced JNK activity
and, to a small extent, p38 and ERK2 activity (data not shown). These
results indicate that signaling through SCFR and FcRI may indeed be
through different pathways.
|
RI or SCFR-mediated JNK, p38, and
ERK2 activation
To define the differential regulation of signaling through SCFR
and FcRI, we determined if wortmannin, a known inhibitor of
PI3-kinase, affected activation of SCFR-mediated JNK, p38, and ERK2
activation in MC/9 cells. We previously showed that FcRI-mediated
activation of JNK and p38 (to a lesser extent) was inhibited by
wortmannin, whereas ERK activation was resistant to wortmannin (11, 12). This was confirmed in Figure 4,
A–C, in the presence of 100 nM wortmannin. In
contrast to signaling through FcRI, 100 nM (or higher
concentrations) wortmannin failed to alter SCF-induced activation of
JNK, p38, and ERK2 activation in these cells (Fig. 4, D–F).
|
RI or SCFR is inhibited by wortmannin
To confirm the susceptibility of other pathways stimulated by SCF
to wortmannin, we assessed Akt1 activation. The akt
proto-oncogene encodes a serine/threonine kinase, Akt1 (23), which is
rapidly and specifically activated by growth factors such as
platelet-derived growth factor (24). It is well known that Akt1
activation is mediated through PI3-kinase signaling (25), and Akt1
activation is predicted to parallel PI3-kinase activity. Akt1 was
activated by aggregation of FcRI or by ligation of SCFR. As shown in
Figure 5, Akt1 activation through either
FcRI (Fig. 5A) or SCFR (Fig. 5B) was inhibited
by wortmannin in a dose-dependent manner and there was no difference in
susceptibility through either receptor.
|
RI or SCFR-mediated JNK,
p38, and ERK2 activation
We examined the effects of CsA, FK506, and RAP on FcRI or
SCF-mediated JNK, p38, and ERK2 activation in MC/9 cells. CsA and FK506
share a common mechanism of action, the inhibition of
calcium/calmodulin phosphatase, whereas RAP acts at a different level.
CsA (1 µg/ml), FK506 (10 ng/ml), but not RAP (10 ng/ml) inhibited JNK
and p38 activation via FcRI (Fig. 6,
A and B). Cyclosporin H, a nonimmunosuppressive
analogue of CsA that cannot bind to cyclosporin A or B, failed to
affect JNK activation (data not shown). These immunosuppressants did
not affect FcRI-mediated ERK2 activation (Fig. 6C). In
contrast to FcRI-mediated activation of these kinases, CsA and FK506
failed to inhibit SCF-induced activation of JNK, p38, and ERK2 (Fig. 6, D–F).
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
10 min
(34, 35, 36, 37). However, little is known about downstream signaling events
other than the activation of ERK.
The mammalian MAP kinase family includes three members, ERK, JNK, and
p38. We recently demonstrated that JNK and p38 are also activated
strongly via FcRI as well as ERK in mast cells (11, 12). These
kinases are expected to regulate gene expression by phosphorylating
transcription factors, although delineation of the regulatory
mechanisms is not entirely clear. In our investigations, SCF also
induced the activation of all three members of the MAP kinase family.
The kinetics of activation of the MAP kinases via SCFR were similar to
those exhibited via FcRI. The magnitude of JNK and p38 activation
via SCFR was weaker than that observed through FcRI, but the
magnitude of ERK2 activation via SCFR was as strong as that via FcRI
in MC/9 cells.
Activation of JNK via FcRI was strongly (90%) inhibited, and p38
activity was partially (50%) inhibited by wortmannin, as we previously
showed (11, 12). This suggests that FcRI-mediated activation of
PI3-kinase is linked to the activation of JNK and p38. However,
SCF-induced activation of JNK and p38 was not affected by wortmannin in
MC/9 cells. This implies that the activation of PI3-kinase is not
required for SCF-induced activation of JNK and p38 in these cells.
Nonetheless, both SCFR and FcRI ligation stimulated the activation
of PI3-kinase as detected by activation of the kinase Akt1, which is
directly regulated by phosphatidylinositol 3,4-bisphosphate (22).
Wortmannin inhibited Akt1 activation by both SCFR and FcRI in a
similar dose-dependent manner.
Further differences were observed between these two receptors when the
effects of the immunosuppressants CsA and FK506 were examined.
FcRI-mediated activation of JNK and p38 were inhibited by CsA and
FK506, but not RAP, although RAP inhibits the basal levels of JNK
activity in some cell lines (38). The mechanism underlying the
inhibitory effects of CsA and FK506 on these kinases is not defined at
this time. However, the combination of TCR/CD28 ligation leading to JNK
activation is similarly inhibited by CsA (39). These data and the
failure of CsH to inhibit the activation of these kinases indicate that
calcineurin is involved in the FcRI-mediated pathway linked to JNK
and p38 activation. In parallel to the absence of an inhibition by
wortmannin, SCF-induced activation of JNK and p38 were also insensitive
to CsA and FK506. These data clearly identify that the upstream pathway
linked to JNK or p38 activation is different following signaling
through FcRI and SCFR. ERK2 activation via FcRI or SCFR was
resistant to wortmannin, CsA, and FK506, suggesting that neither
PI3-kinase nor calcineurin is involved as an upstream regulator of the
signaling pathway linked to ERK activation by these receptors.
We examined the effect of SCF on TNF- production in Ag-stimulated
and sensitized MC/9 cells. SCF alone did not induce TNF- production
and little stimulation of TNF- promoter activity was observed.
However, SCF significantly augmented FcRI-mediated TNF-
production and activation of the TNF- promoter following FcRI
aggregation, suggesting that SCF can augment TNF- production at the
level of gene transcription. We previously suggested that activation of
PI3-kinase, MEK kinases, and JNK following the aggregation of FcRI
is required for TNF- production in mast cells (12). We determined
whether costimulation of FcRI and SCFR can enhance the activity of
MAP kinases compared with either stimulus alone. Optimal amounts of OVA
(10 µg/ml) strongly activate the MAP kinases and induce TNF-
production. Addition of suboptimal amounts of OVA (0.1 µg/ml) to
passively sensitized cells induced only weak TNF- production and
little activation of JNK and p38; significant activation of ERK2 was
still observed in the presence of low Ag concentrations. Ligation of
SCFR with ligation of FcRI in the presence of 0.1 µg/ml OVA
strongly enhanced JNK activation with little augmentation of p38 and
ERK2 activity (less than additive effects), and TNF- production was
also strongly enhanced by this costimulation. These results indicate a
correlation between JNK activity and TNF- production. The TNF-
promoter contains a cyclic AMP response element and a binding site for
NFAT in the 
3 region (40, 41). In activated T cells, both the
binding of activated (phosphorylated) c-Jun and ATF-2 to the cyclic AMP
response element site together with the binding of NFAT leads to the
activation of TNF- gene transcription (42, 43). JNK can
phosphorylate both c-Jun and ATF-2, suggesting that it can enhance the
binding of c-Jun and ATF-2 and positively control TNF- gene
transcription. However, SCF can activate JNK but does not induce
TNF- production on its own. This implies that JNK activation per se
is not sufficient to initiate TNF- production in mast cells but
requires the activation of a second, but distinct signal transduction
pathway. The calcium-dependent translocation of calcineurin-NFAT
complex to the nucleus likely represents this second signaling pathway
as mast cells, similar to T cells, express NFAT (44).
In summary, we demonstrate that SCF through SCFR and Ag-IgE complexes
through FcRI induce the activation of similar members of the MAP
kinase family in MC/9 cells via pathways that are regulated differently
in terms of dependency on PI3-kinase and calcineurin activation.
Further, SCF augments FcRI-mediated activation of these kinases,
particularly JNK, and TNF- production. These findings define the
importance of SCF not only as a mast cell growth factor but also as an
amplifier of allergic inflammation by modulation of the degree of mast
cell activation and cytokine production.
|
Acknowledgments |
|---|
|
Footnotes |
|---|
2 Address correspondence and reprint requests to Dr. Erwin W. Gelfand, Department of Pediatrics, National Jewish Medical and Research Center, 1400 Jackson Street, Denver, CO 80206.
3 Abbreviations used in this paper: FcRI, high affinity Fc receptors for IgE; CsA, cyclosporin A; ERK, extracellular signal-related kinase; JNK, c-Jun amino-terminal kinase; MAP, mitogen-activated protein; MBP, myelin basic protein; PI3-kinase, phosphatidylinositol 3-kinase; SCF, stem cell factor; RAP, rapamycin; MEK, mitogen-activated protein kinase/extracellular signal-regulated kinase kinase; GST, glutathione S-transferase.
Received for publication January 20, 1998. Accepted for publication June 8, 1998.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
RI or to calcium ionophores. Nature 339:64.[Medline]
/cachectin. Nature 346:274.[Medline]
(TNF-)/cachectin by mouse mast cells stimulated via the FcRI: a mechanism for the sustained action of mast cell-derived TNF- during IgE-dependent biological responses. J. Exp. Med. 174:103., which induces endothelial leukocyte adhesion molecule 1. Proc. Natl. Acad. Sci. USA 88:4220.RI on mast cells stimulates c-Jun amino-terminal kinase activity: a response inhibited by wortmannin. J. Biol. Chem. 271:12762. production is regulated by MEK kinase. Proc. Natl. Acad. Sci. USA 94:6358.RI-mediated induction of nuclear factor of activated T cells. J. Biol. Chem. 270:16333.This article has been cited by other articles:
|
|
 |
|
  B. O. Barnstein, G. Li, Z. Wang, S. Kennedy, C. Chalfant, H. Nakajima, K. D. Bunting, and J. J. Ryan Stat5 Expression Is Required for IgE-Mediated Mast Cell Function. J. Immunol., September 1, 2006; 177(5): 3421 - 3426. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Sawada, S. Shimizu, T. Tamatani, S. Kanegasaki, H. Saito, A. Tanaka, N. Kambe, T. Nakahata, and H. Matsuda Stem Cell Factor Has a Suppressive Activity to IgE-Mediated Chemotaxis of Mast Cells J. Immunol., March 15, 2005; 174(6): 3626 - 3632. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. T. M. Boudreau, D. W. Hoskin, and T.-J. Lin Phosphatase inhibition potentiates IL-6 production by mast cells in response to Fc{varepsilon}RI-mediated activation: involvement of p38 MAPK J. Leukoc. Biol., November 1, 2004; 76(5): 1075 - 1081. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. R. Hundley, A. M. Gilfillan, C. Tkaczyk, M. V. Andrade, D. D. Metcalfe, and M. A. Beaven Kit and Fc{epsilon}RI mediate unique and convergent signals for release of inflammatory mediators from human mast cells Blood, October 15, 2004; 104(8): 2410 - 2417. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Suzuki, H. Nakajima, K. Ikeda, Y. Maezawa, A. Suto, H. Takatori, Y. Saito, and I. Iwamoto IL-4-Stat6 Signaling Induces Tristetraprolin Expression and Inhibits TNF-{alpha} Production in Mast Cells J. Exp. Med., December 1, 2003; 198(11): 1717 - 1727. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. B. Hock and M. A. Brown Nuclear Factor of Activated T Cells 2 Transactivation in Mast Cells: A NOVEL ISOFORM-SPECIFIC TRANSACTIVATION DOMAIN CONFERS UNIQUE Fc{epsilon}RI RESPONSIVENESS J. Biol. Chem., July 11, 2003; 278(29): 26695 - 26703. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X. Guo, R. E. Gerl, and J. W. Schrader Defining the Involvement of p38{alpha} MAPK in the Production of Anti- and Proinflammatory Cytokines Using an SB 203580-resistant Form of the Kinase J. Biol. Chem., June 13, 2003; 278(25): 22237 - 22242. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Minamino, T. Yujiri, N. Terada, G. E. Taffet, L. H. Michael, G. L. Johnson, and M. D. Schneider MEKK1 is essential for cardiac hypertrophy and dysfunction induced by Gq PNAS, March 19, 2002; 99(6): 3866 - 3871. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Kushida, Y. Kabuyama, O. Yamaguchi, and Y. Homma Essential role for extracellular Ca2+ in JNK activation by mechanical stretch in bladder smooth muscle cells Am J Physiol Cell Physiol, October 1, 2001; 281(4): C1165 - C1172. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Ishizuka, F. Okajima, M. Ishiwara, K. Iizuka, I. Ichimonji, T. Kawata, H. Tsukagoshi, K. Dobashi, T. Nakazawa, and M. Mori Sensitized Mast Cells Migrate Toward the Agen: A Response Regulated by p38 Mitogen-Activated Protein Kinase and Rho-Associated Coiled-Coil-Forming Protein Kinase J. Immunol., August 15, 2001; 167(4): 2298 - 2304. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. H. P. Oliveira, C. M. Hogaboam, A. Berlin, and N. W. Lukacs SCF-induced airway hyperreactivity is dependent on leukotriene production Am J Physiol Lung Cell Mol Physiol, June 1, 2001; 280(6): L1242 - L1249. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Chayama, P. J. Papst, T. P. Garrington, J. C. Pratt, T. Ishizuka, S. Webb, S. Ganiatsas, L. I. Zon, W. Sun, G. L. Johnson, et al. Role of MEKK2-MEK5 in the regulation of TNF-alpha gene expression and MEKK2-MKK7 in the activation of c-Jun N-terminal kinase in mast cells PNAS, March 22, 2001; (2001) 81021898. [Abstract] [Full Text]
|
|
|
|
 |
|
 J. Talkington and S. P. Nickell Role of Fc Gamma Receptors in Triggering Host Cell Activation and Cytokine Release by Borrelia burgdorferi Infect. Immun., January 1, 2001; 69(1): 413 - 419. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Miura and D. W. MacGlashan Jr Phosphatidylinositol-3 kinase regulates p21ras activation during IgE-mediated stimulation of human basophils Blood, September 15, 2000; 96(6): 2199 - 2205. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Chayama, P. J. Papst, T. P. Garrington, J. C. Pratt, T. Ishizuka, S. Webb, S. Ganiatsas, L. I. Zon, W. Sun, G. L. Johnson, et al. Role of MEKK2-MEK5 in the regulation of TNF-alpha gene expression and MEKK2-MKK7 in the activation of c-Jun N-terminal kinase in mast cells PNAS, April 10, 2001; 98(8): 4599 - 4604. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
