Departments of 1 Pediatrics, 2 Medicine, and 3 Physiology and Cellular Biophysics, College of Physicians and Surgeons and St. Luke's Roosevelt Hospital Center, Columbia University, New York, New York 10019
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ABSTRACT |
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Vitronectin, which ligates the
v
3-integrin, increases both lung
capillary permeability and lung endothelial Ca2+. In stable
monolayers of bovine pulmonary artery endothelial cells (BPAECs) viewed
with confocal microscopy, multimeric vitronectin aggregated the
apically located
v
3-integrin. This caused
arachidonate release that was inhibited by pretreating the monolayers
with the anti-
v
3 monoclonal antibody
(MAb) LM609. No inhibition occurred in the presence of the isotypic MAb
PIF6, which recognizes the integrin
v
5.
Vitronectin also caused membrane translocation and phosphorylation of
cytosolic phospholipase A2 (cPLA2) as well as
tyrosine phosphorylation of the mitogen-activated protein kinase (MAPK)
extracellular signal-regulated kinase (ERK) 2. The cPLA2 inhibitor arachidonyl trifluoromethylketone, the tyrosine
kinase inhibitor genistein, and the MAPK kinase inhibitor PD-98059 all blocked the induced arachidonate release. PD-98059 did not inhibit the
increase of cytosolic Ca2+ or cPLA2
translocation, although it blocked tyrosine phosphorylation of ERK2.
Moreover, although the intracellular Ca2+ chelator
MAPTAM also inhibited arachidonate release, it did not inhibit tyrosine
phosphorylation of ERK2. These findings indicate that ligation of
apical
v
3 in BPAECs caused ERK2
activation and an increase of intracellular Ca2+, both
conjointly required for cPLA2 activation and arachidonate release. This is the first instance of a tyrosine
phosphorylation-initiated "two-hit" signaling pathway that
regulates an integrin-induced proinflammatory response.
vitronectin; SC5b-9; arachidonate; cytosolic phospholipase A2
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INTRODUCTION |
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THE
V
3-integrin,
a member of the cytoadhesive family of integrins (9), is
richly expressed in lung microvessels (33), but its
functional role in pulmonary physiology remains inadequately understood. Because the role of the integrin has been discussed largely
in the context of angiogenesis and wound healing (7, 9,
21), its presence in the nonproliferating lung vascular bed
under quiescent conditions needs to be better understood. The integrin
is luminally expressed in lung microvascular endothelium where it may
play a proinflammatory role in lung vascular disease, for example, by
increasing capillary permeability (36) and mobilizing endothelial cell (EC) Ca2+ (3). However, other
proinflammatory responses may also result.
We considered that v
3 ligation of lung
ECs may activate cytosolic phospholipase A2
(cPLA2), which is potentially an important feature of the
EC inflammatory response in lung. cPLA2 activation releases
free arachidonic acid that may generate prostaglandins and other
oxidated compounds and cause Ca2+ mobilization (14,
19, 31). In the family of cytoadhesive integrins, ligation of
1-integrins has been shown to induce cPLA2 activation (4, 5, 35, 40, 42). However, these reports concern circulating or proliferating cells and do not represent responses that may be relevant to cells under stable conditions, such
as those of the ECs of lung vessels. Furthermore, it is not clear that
ligation of the
v
3-integrin by soluble
ligands leads to cPLA2 activation, nor are the activation
mechanisms known.
In confluent EC monolayers, cPLA2 is located in the
cytosol, but on activation, it translocates to membranes
(32). The translocation is attributable to an increase of
EC Ca2+, although activation also requires the enzyme to be
phosphorylated (14). Signaling pathways acting through
tyrosine phosphorylation (TyrP) may regulate both events because TyrP
activates the extracellular signal-regulated kinase (ERK)
mitogen-activated protein kinase (MAPK) that phosphorylates
cPLA2 (14), and it also activates phospholipase C (PLC
), leading to EC Ca2+ increases
(3). Because we have shown that
v
3 ligation induces several signaling
pathways in lung ECs (2, 3, 36), here we tested the extent
to which these pathways interact for cPLA2 activation.
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MATERIALS AND METHODS |
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Cells, Reagents, and Antibodies
Bovine pulmonary artery endothelial cells (BPAECs; American Type Culture Collection) were maintained as described (2). The following were purchased: fura 2-AM (Molecular Probes), EGTA, EDTA, and genistein (Sigma, St. Louis, MO); arachidonyl trifluoromethylketone (AACOCF3), 1,2-bis(o-amino-5'-methylphenoxy)ethane-N,N,N'N'-tetraacetic acid tetraacetoxymethyl ester (MAPTAM; Calbiochem, La Jolla, CA); the secondary antibody donkey anti-mouse IgG (Jackson ImmunoResearch, West Grove, PA); affinity-purified polyclonal anti-phosphotyrosine rabbit serum (ICN Biomedical, Costa Mesa, CA); protein A/protein G-agarose, polyclonal anti-ERK2 (C-14), and monoclonal anti-cPLA2 (Santa Cruz Biotechnology, Santa Cruz, CA); the inhibitor of MAPK kinase (MEK) 1 inhibitor PD-98059 (New England Biolabs, Beverly, MA); [3H]arachidonic acid (New England Nuclear, Wilmington, DE); and the monoclonal antibody (MAb) PIF6 against theRelease of [3H]Arachidonic Acid From BPAECs
Arachidonate release was quantified as the increase of supernatant radioactivity in cells loaded with [3H]arachidonic acid. This is a standard indicator of cPLA2 activation (22, 23, 25). BPAECs grown in 24-well plates were prelabeled with 0.5-1 µCi/ml of [3H]arachidonate (100 Ci/mmol for 18 h at 37°C), washed (serum-free DMEM and 0.2% fatty acid-free albumin for 2 h at 37°C), and exposed to multimeric vitronectin. After 15 min, the collected supernatants (centrifuged at 3,000 rpm for 10 min) and cell lysates were subjected to liquid scintillation counting. The supernatant radioactivity was calculated as a percentage of the total radioactivity (cell lysate plus supernatant). The radioactivity released under experimental conditions is expressed as a percentage of release under baseline conditions. Because of considerable interbatch variation in arachidonate release, baseline secretion was determined for each batch of monolayers. Because inhibitors independently increase arachidonate release (22, 34), in inhibitor studies, we compared these data against inhibitor-treated controls as previously reported by others (22, 23, 34).Membrane Translocation of cPLA2
BPAECs were treated with multimeric vitronectin (400 µg/ml for 15 min) in both the presence and absence of PD-98059 (10 µmol/l for 15 min for 37°C), then were permeabilized, fixed, blocked, and immunofluorescently stained with anti-cPLA2 MAb and FITC-labeled goat anti-mouse IgG as described (28). The monolayers were imaged with fluorescence confocal microscopy.Immunofluorescent Labeling of the
v
3-Integrin
Ca2+ Imaging of Single Endothelial Cells
We used methods previously described by our laboratory (41). BPAEC monolayers were fura 2 loaded by the addition of fura 2-AM (5 µmol/l for 30 min at 20°C) and then were maintained at 37°C during digital imaging. Intracellular Ca2+ concentration ([Ca2+]i) was determined in a 2-µm2 window placed over 340- to 380-nm ratio images of single cells based on appropriate calibrations and a fura 2-Ca2+ dissociation constant (Kd) of 224 nmol/l (10).Immunoprecipitation and Immunoblotting of ERK2
BPAECs in confluent monolayers were lysed (4°C) in buffer containing 150 mmol/l of NaCl, 50 mmol/l of Tris base, 2 mmol/l of EGTA, 50 mmol/l of NaF, 0.1% SDS, 1% Nonidet P-40, 10 µg/ml of leupeptin, 10 µg/ml of aprotinin, 1 mmol/l of phenylmethylsulfonyl fluoride, and 1 mmol/l of the phosphatase inhibitor sodium orthovanadate, pH 7.5. After the lysates were cleared (14,000 rpm for 15 min), protein concentrations were determined (DC Protein Assay, Bio-Rad, Richmond, CA), and ERK2 was immunoprecipitated and subjected to SDS-PAGE, transfer, and immunoblotting by methods previously described by Bhattacharya et al. (2).Mobility Shift Assay of cPLA2 Phosphorylation
BPAEC lysates were treated with 4× Laemmli buffer, boiled for 5 min, and subjected to 8% SDS-PAGE (20 mA/gel). Electrophoresis was continued for 3 h after the tracking dye exited the gel to increase separation between the native and phosphorylated isoforms (26). Transfer and immunoblotting were carried out with methods previously described by Bhattacharya et al. (2).Statistics
All data are means ± SE. Differences between groups were tested by paired t-test for two groups and by the Newman-Keuls test for more than two groups. Significance was accepted at P < 0.05. ![]() |
RESULTS |
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Vitronectin-Induced Arachidonate Release
Addition of vitronectin (15 min at 37°C) to BPAEC monolayers loaded with [3H]arachidonate (see MATERIALS AND METHODS) caused an enhanced, concentration-dependent release of radioactivity (Fig. 1A), indicating the release of arachidonate and its metabolites, which was attributable to cPLA2 activation (22, 23, 25). Vitronectin ligates the integrins
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The Signaling Pathway
Protein TyrP.
As Bhattacharya and colleagues (2, 3) have shown
previously, ligation of the v
3-integrin
enhances TyrP in ECs. Here, incubation of monolayers with the tyrosine
kinase inhibitor genistein completely blocked vitronectin-induced
arachidonate release (Fig. 1C), implicating
v
3-induced TyrP mechanisms in the
arachidonate response.
MAPK.
Because TyrP of MAPK may lead to cPLA2 activation, we
determined the role of MAPK in these responses. The MEK-1 inhibitor PD-98059 (23) blocked vitronectin-induced
arachidonate release (Fig. 1C). Moreover, as shown by the
bands in Fig. 2A,
(bottom, lane 2), immunoprecipitation experiments indicated
that TyrP of ERK2 was enhanced in vitronectin-treated monolayers
compared with that in control monolayers (lane 1). This TyrP
response was also inhibited by PD-98059 (compare Fig. 2A,
lanes 3 and 4). These results indicate that ERK2
was involved in these vitronectin-induced responses. Bhattacharya et
al. (3) previously showed that vitronectin treatment
increases [Ca2+]i in BPAEC monolayers. To
determine a possible role of [Ca2+]i, we
treated monolayers with the [Ca2+]i chelator
MAPTAM. MAPTAM decreased baseline TyrP but failed to inhibit the
postvitronectin increase of TyrP (Fig. 2A,
bottom, compare lanes 5 and 6, and
Fig. 2B, bars at left and right).
These findings indicate that the enhanced TyrP of ERK2 was not
[Ca2+]i dependent.
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cPLA2.
The cPLA2 inhibitor AACOCF3 (1)
completely blocked vitronectin-induced arachidonate release (Fig.
1C), providing further evidence for cPLA2
activation. Because this activation is associated with
cPLA2 translocation from the cytosol to the membrane
(28), we assayed the translocation. We exposed BPAECs to
vitronectin. Then, after fixation and permeabilization, we
immunofluorescently labeled cPLA2 with target-specific
antibodies. The principle of this assay was that membrane-bound
cPLA2 is not removed from permeabilized cells during washes
and may be detected by immunofluorescence. Although no fluorescence was
evident in control monolayers (Fig. 3,
left), vitronectin treatment resulted in well-defined
fluorescent staining (Fig. 3, right), indicating that
v
3 ligation induced membrane
translocation of cPLA2.
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Site of v
3 Aggregation in BPAECs
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The Role of [Ca2+]i
Bhattacharya et al. (3) reported that ligation of the
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A comparison of previous vitronectin-induced [Ca2+]i responses in BPAECs (3) with the present data revealed a nonlinear correlation between [Ca2+]i increase and arachidonate release (Fig. 6C). This plot indicated that significant arachidonate release occurred at concentrations of vitronectin that increased [Ca2+]i 20% or more above baseline, showing a [Ca2+]i threshold of 80-100 nmol/l for vitronectin-induced arachidonate release.
SC5b-9
Multimeric vitronectin is the
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DISCUSSION |
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In previous experiments, our laboratory determined that ligation
of the v
3-integrin in lung endothelial
monolayers activates cytosolic tyrosine kinases, one consequence of
which is the TyrP of focal adhesion proteins (2) and
another of which is the induction of the PLC
-inositol
1,4,5-trisphosphate pathway that increases
[Ca2+]i (3). However, the
proinflammatory importance of these signaling pathways was not
clear. Now we show that ligating
v
3 with
vitronectin caused genistein-inhibitable arachidonate release that was
attributable to membrane translocation and phosphorylation of
cPLA2. Thus TyrP due to
v
3
ligation in ECs constitutes a sufficient mechanism for
cPLA2-induced arachidonate release, indicating a role for
v
3 in augmenting and sustaining
inflammatory processes (14).
Unexpectedly, the arachidonate release was inhibited by the blockade of
two different signaling pathways. Thus in the presence of the
[Ca2+]i chelator MAPTAM and the MEK inhibitor
PD-98059, each given separately, the vitronectin-induced arachidonate
release was blocked. The inhibition seen with MAPTAM confirms the
acknowledged role of [Ca2+]i in arachidonate
activation (14). Importantly, the PD-98059-mediated inhibition of ERK2 TyrP and arachidonate release indicated that MAPK activation was concomitantly required for cPLA2
activation. Moreover, MAPTAM did not block TyrP of ERK2, and PD-98059
did not inhibit the [Ca2+]i increase,
indicating that these blockers did not cross inhibit the two arms of
the pathway. Hence, we conclude that cPLA2 activation that
follows v
3 ligation in lung ECs was
induced by a "two-hit" mechanism resulting from the convergence of
tyrosine kinase pathways that both increased
[Ca2+]i and activated MAPK, respectively.
Signaling responses of cytoadhesive integrins have been extensively
reported in the context of cell-matrix interactions and cell cycle
progression (9). Thus
v
3-induced MAPK activation in ECs occurs
in angiogenesis (7, 21). Integrin-induced responses attributable to fibroblast spreading on a fibronectin matrix are associated with MAPK activation and arachidonate release
(4). Despite their qualitative similarity to the data
shown here, the relevance of these reported responses to stable,
nonproliferating ECs has remained unclear. In this regard, three new
conclusions may be drawn from our present findings. First, by confocal
microscopy, we obtained definitive evidence that vitronectin aggregated
the lumen-facing
v
3-integrin. Considered
in the context of the TyrP and [Ca2+]i
responses that occur within 1 min of
v
3
ligation (2, 3), this finding suggests that luminal
integrin ligation initiates the signaling cascade. The signaling may be
further regulated by processes causing translocation of vitronectin
from the apical to the basal surfaces of ECs (17). Second,
because our experiments were conducted in stable monolayers, it is
clear that ECs do not have to be in cell cycle progression to support
integrin-induced MAPK activation. Third, the two-hit mechanism
discussed above has not been reported previously and may be
characteristic of responses attributable to the luminal
v
3-integrin.
Although understanding of the signaling pathways induced by the
v
3-integrin in stable ECs remains
inadequate, our laboratory previously reported (2) that
ligation of the integrin causes focal adhesion kinase (FAK)
and Shc TyrP in ECs. Because the association of FAK and Shc with Grb2
leads to activation of Ras and subsequently of ERK MAPK
(29), our finding that ERK MAPK TyrP was enhanced by
v
3 ligation suggests that the present
signaling was routed through the Grb2-Ras pathway. Figure
8 summarizes our view that after soluble
ligands bind and aggregate, the
v
3-integrin TyrP pathways first
bifurcate into the PLC
inositol
1,4,5-trisphosphate and FAK
Shc
Grb2 directions, then
subsequently converge through [Ca2+]i
increase and MAPK activation on cPLA2 activation and
release of arachidonate products. However, these considerations remain speculative because we did not obtain direct determinations.
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Our model of cPLA2 activation involving
[Ca2+]i increase and MAPK activation may be
relevant in the context of small increases of EC
[Ca2+]i. Although the Ca2+
dependence of cPLA2 activation has been discussed in
relation to large [Ca2+]i increases, e.g.,
those in which [Ca2+]i increases to
micromolar levels (11, 18) in lung microvessels, EC
[Ca2+]i increases are relatively modest. Thus
an increase in lung vascular pressure or an intravascular infusion of
tumor necrosis factor- increases EC
[Ca2+]i in lung capillaries by only 100 nmol/l (12, 13). These modest increases are nevertheless
proinflammatory because they increase the expression of the leukocyte
adhesion receptor P-selectin (13). Perhaps MAPK activation
sensitizes the effect of a modest [Ca2+]i
increase such that cPLA2 activation occurs in the absence
of large and potentially deleterious elevations of
[Ca2+]i. A consideration of our previous and
present vitronectin data indicates that significant arachidonate
release occurred after [Ca2+]i increased 20%
above baseline (Fig. 6C), suggesting that the sensitizing
effect of MAPK activation may occur at
[Ca2+]i increases in the range of 100 nmol/l.
Our findings bear on the potential importance of the
v
3-integrin as a significant
proinflammatory receptor in the lung. Inflammatory consequences of
v
3 ligation may be considerable because
the lung vascular bed extensively expresses the integrin both on the
luminal and abluminal aspects of ECs (33). Vitronectin induces
v
3 aggregation on the luminal
surface of ECs. This may be relevant to responses generated by
circulating ligands such as the vitronectin-containing complement
product SC5b-9 (2) or the thrombin-antithrombin complex
(39) that is released in conditions such as bypass surgery
or sepsis (8, 15). We previously showed (2) that
SC5b-9 ligates the
v
3-integrin and
induces TyrP of endothelial proteins. Here, we show that SC5b-9 causes arachidonate release similar to that caused by vitronectin. This finding reaffirms our view that ligation of the luminal
v
3 of ECs may constitute a
proinflammatory mechanism in conditions associated with complement activation.
In conclusion, the binding of the
v
3-integrin constitutes a basis for
cPLA2 activation and arachidonate release from lung ECs
that may occur under pathophysiological conditions. A role of the
integrin in lung inflammation requires consideration because it not
only directs the migration of neutrophils (24) and
promotes removal of apoptotic cells (27, 38), but
through arachidonate release, it may lead to increased vascular
permeability (37), vasoconstriction (30),
gene regulation (16), and alveolocapillary cross talk
(12). Released arachidonate may generate feedback effects
by itself, inducing Ca2+ influx (19, 31) and
further activating ERK (6), thereby amplifying
proinflammatory signaling and further augmenting lung injury.
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ACKNOWLEDGEMENTS |
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This study was supported by National Heart, Lung, and Blood Institute Grants HL-36024, HL-57556 (both to J. Bhattacharya), and HL-54157 (to S. Bhattacharya).
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FOOTNOTES |
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Address for reprint requests and other correspondence: S. Bhattacharya, St. Luke's-Roosevelt Hospital Center, 1000 10th Ave, New York, NY 10019 (E-mail: sb80{at}columbia.edu).
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 17 August 2000; accepted in final form 30 November 2000.
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REFERENCES |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
1.
Ackermann, EJ,
Conde-Frieboes K,
and
Dennis EA.
Inhibition of macrophage Ca2+-independent phospholipase A2 by bromoenol lactone and trifluoromethyl ketones.
J Biol Chem
270:
445-450,
1995
2.
Bhattacharya, S,
Fu C,
Bhattacharya J,
and
Greenberg S.
Soluble ligands of the v
3-integrin mediate enhanced tyrosine phosphorylation of multiple proteins in adherent bovine pulmonary artery endothelial cells.
J Biol Chem
270:
16781-16787,
1995
3.
Bhattacharya, S,
Ying X,
Fu C,
Patel R,
Kuebler W,
Greenberg S,
and
Bhattacharya J.
v
3-Integrin induces tyrosine phosphorylation-dependent Ca2+ influx in pulmonary endothelial cells.
Circ Res
86:
456-462,
2000
4.
Clark, EA,
and
Hynes RO.
Ras activation is necessary for integrin-mediated activation of extracellular signal-regulated kinase 2 and cytosolic phospholipase A2 but not for cytoskeletal organization.
J Biol Chem
271:
14814-14818,
1996
5.
Cybulsky, AV,
Carbonetto S,
Cyr MD,
McTavish AJ,
and
Huang Q.
Extracellular matrix-stimulated phospholipase activation is mediated by 1-integrin.
Am J Physiol Cell Physiol
264:
C323-C332,
1993
6.
Dulin, NO,
Alexander LD,
Harwalkar S,
Falck JR,
and
Douglas JG.
Phospholipase A2-mediated activation of mitogen-activated protein kinase by angiotensin II.
Proc Natl Acad Sci USA
95:
8098-8102,
1998
7.
Eliceiri, BP,
Klemke R,
Stromblad S,
and
Cheresh DA.
Integrin v
3 requirement for sustained mitogen-activated protein kinase activity during angiogenesis.
J Cell Biol
140:
1255-1263,
1998
8.
Fitch, JC,
Rollins S,
Matis L,
Alford B,
Aranki S,
Collard CD,
Dewar M,
Elefteriades J,
Hines R,
Kopf G,
Kraker P,
Li L,
O'Hara R,
Rinder C,
Rinder H,
Shaw R,
Smith B,
Stahl G,
and
Shernan SK.
Pharmacology and biological efficacy of a recombinant, humanized, single-chain antibody C5 complement inhibitor in patients undergoing coronary artery bypass graft surgery with cardiopulmonary bypass.
Circulation
100:
2499-2506,
1999
9.
Giancotti, FG,
and
Ruoslahti E.
Intergrin signaling.
Science
285:
1028-1032,
1999
10.
Grynkiewicz, G,
Poenie M,
and
Tsien RY.
A new generation of Ca2+ indicators with greatly improved fluorescence properties.
J Biol Chem
260:
3440-3450,
1985[Abstract].
11.
Hirabayashi, T,
Kume K,
Hirose K,
Yokomizo T,
Iino M,
Itoh H,
and
Shimizu T.
Critical duration of intracellular Ca2+ response required for continuous translocation and activation of cytosolic phospholipase A2.
J Biol Chem
274:
5163-5169,
1999
12.
Kuebler, WM,
Parthasarathi K,
Wang PM,
and
Bhattacharya J.
A novel signaling mechanism between gas and blood compartments of the lung.
J Clin Invest
105:
905-913,
2000
13.
Kuebler, WM,
Ying X,
Singh B,
Issekutz AC,
and
Bhattacharya J.
Pressure is proinflammatory in lung venular capillaries.
J Clin Invest
104:
495-502,
1999
14.
Leslie, CC.
Properties and regulation of cytosolic phospholipase A2.
J Biol Chem
272:
16709-16712,
1997
15.
Lin, RY,
Astiz ME,
Saxon JC,
Saha DC,
and
Rackow EC.
Alterations in C3, C4, factor B, and related metabolites in septic shock.
Clin Immunol Immunopathol
69:
136-142,
1993[ISI][Medline].
16.
Mariani, TJ,
Sandefur S,
Roby JD,
and
Pierce RA.
Collagenase-3 induction in rat lung fibroblasts requires the combined effects of tumor necrosis factor- and 12-lipoxygenase metabolites: a model of macrophage-induced, fibroblast-driven extracellular matrix remodeling during inflammatory lung injury.
Mol Biol Cell
9:
1411-1424,
1998
17.
Memmo, LM,
and
McKeown-Longo P.
The v
3-integrin functions as an endocytic receptor for vitronectin.
J Cell Sci
111:
425-433,
1998
18.
Millanvoye-Van Brussel, E,
David-Dufilho M,
Pham TD,
Iouzalen L,
and
Aude Devynck M.
Regulation of arachidonic acid release by calcium influx in human endothelial cells.
J Vasc Res
36:
235-244,
1999[ISI][Medline].
19.
Oike, M,
Droogmans G,
and
Nilius B.
Mechanosensitive Ca2+ transients in endothelial cells from human umbilical vein.
Proc Nat Acad Sci USA
91:
2940-2944,
1994[Abstract].
20.
Panetti, TS,
and
McKeown-Longo PJ.
The v
3-integrin receptor regulates receptor-mediated endocytosis of vitronectin.
J Biol Chem
268:
11492-11495,
1993
21.
Penta, K,
Varner JA,
Liaw L,
Hidai C,
Schatzman R,
and
Quertermous T.
Del1 induces integrin signaling and angiogenesis by ligation of v
3.
J Biol Chem
274:
11101-11109,
1999
22.
Pyne, NJ,
Tolan D,
and
Pyne S.
Bradykinin stimulates cAMP synthesis via mitogen-activated protein kinase-dependent regulation of cytosolic phospholipase A2 and prostaglandin E2 release in airway smooth muscle.
Biochem J
328:
689-694,
1997[ISI][Medline].
23.
Qiu, Z,
Gijon MA,
de Carvalho MS,
Spencer DM,
and
Leslie CC.
The role of calcium and phosphorylation of cytosolic phospholipase A2 in regulating arachidonic acid release in macrophages.
J Biol Chem
273:
8203-8211,
1998
24.
Rainger, GE,
Buckley CD,
Simmons DL,
and
Nash GB.
Neutrophils sense flow-generated stress and direct their migration through v
3-integrin.
Am J Physiol Heart Circ Physiol
276:
H858-H864,
1999
25.
Ricupero, D,
Taylor L,
and
Polgar P.
Interactions of bradykinin, calcium, G-protein and protein kinase in the activation of phospholipase A2 in bovine pulmonary artery endothelial cells.
Agents Actions
40:
110-118,
1993[ISI][Medline].
26.
Sa, G,
Murugesan G,
Jaye M,
Ivashchenko Y,
and
Fox PL.
Activation of cytosolic phospholipase A2 by basic fibroblast growth factor via a p42 mitogen-activated protein kinase-dependent phosphorylation pathway in endothelial cells.
J Biol Chem
270:
2360-2366,
1995
27.
Savill, J,
Hogg N,
Ren Y,
and
Haslett C.
Thrombospondin cooperates with CD36 and the vitronectin receptor in macrophage recognition of neutrophils undergoing apoptosis.
J Clin Invest
90:
1513-1522,
1992[ISI][Medline].
28.
Schievella, AR,
Regier MK,
Smith WL,
and
Lin LL.
Calcium-mediated translocation of cytosolic phospholipase A2 to the nuclear envelope and endoplasmic reticulum.
J Biol Chem
270:
30749-30754,
1995
29.
Schlaepfer, DD,
Jones KC,
and
Hunter T.
Multiple Grb2-mediated integrin-stimulated signaling pathways to ERK2/mitogen-activated protein kinase: summation of both c-Src- and focal adhesion kinase-initiated tyrosine phosphorylation events.
Mol Cell Biol
18:
2571-2585,
1998
30.
Seeger, W,
Hartmann R,
Neuhoff H,
and
Bhakdi S.
Local complement activation, thromboxane-mediated vasoconstriction, and vascular leakage in isolated lungs. Role of the terminal complement sequence.
Am Rev Respir Dis
139:
88-99,
1989[ISI][Medline].
31.
Shuttleworth, TJ.
Arachidonic acid activates the noncapacitative entry of Ca2+ during [Ca2+]i oscillations.
J Biol Chem
271:
21720-21725,
1996
32.
Sierra-Honigmann, MR,
Bradley JR,
and
Pober JS.
"Cytosolic" phospholipase A2 is in the nucleus of subconfluent endothelial cells but confined to the cytoplasm of confluent endothelial cells and to the nuclear envelope and cell junctions upon histamine stimulation.
Lab Invest
74:
684-695,
1996[Medline].
33.
Singh, B,
Fu C,
and
Bhattacharya J.
Vascular expression of the v
3-integrin in lung and other organs.
Am J Physiol Lung Cell Mol Physiol
278:
L217-L226,
2000
34.
Susztak, K,
Mocsai A,
Ligeti E,
and
Kapus A.
Electrogenic H+ pathway contributes to stimulus-induced changes of internal pH and membrane potential in intact neutrophils: role of cytoplasmic phospholipase A2.
Biochem J
325:
501-510,
1997[ISI][Medline].
35.
Szabo, MC,
Teague TK,
and
McIntyre BW.
Regulation of lymphocyte pseudopodia formation by triggering the integrin 4/
1.
J Immunol
154:
2112-2124,
1995
36.
Tsukada, H,
Ying X,
Fu C,
Ishikawa S,
McKeown-Longo P,
Albelda S,
Bhattacharya S,
Anderson B,
and
Bhattacharya J.
Ligation of the the v
3-integrin increases capillary hydraulic conductivity of rat lung.
Circ Res
77:
651-659,
1995
37.
Vincent, PA,
Kreienberg PB,
Minnear FL,
Saba TM,
and
Bell DR.
Simultaneous measurement of fluid and protein permeability in isolated rabbit lungs during edema.
J Appl Physiol
73:
2440-2447,
1992
38.
Walsh, GM,
Sexton DW,
Blaylock MG,
and
Convery CM.
Resting and cytokine-stimulated human small airway epithelial cells recognize and engulf apoptotic eosinophils.
Blood
94:
2827-2835,
1999
39.
Wells, MJ,
and
Blajchman MA.
In vivo clearance of ternary complexes of vitronectin-thrombin-antithrombin is mediated by hepatic heparan sulfate proteoglycans.
J Biol Chem
273:
23440-23447,
1998
40.
Whitfield, RA,
and
Jacobson BS.
The 1-integrin cytosolic domain optimizes phospholipase A2-mediated arachidonic acid release required for NIH-3T3 cell spreading.
Biochem Biophys Res Commun
258:
306-312,
1999[ISI][Medline].
41.
Ying, X,
Minamiya Y,
Fu C,
and
Bhattacharya J.
Ca2+ waves in lung capillary endothelium.
Circ Res
79:
898-908,
1996
42.
Zhu, X,
Munoz NM,
Kim KP,
Sano H,
Cho W,
and
Leff AR.
Cytosolic phospholipase A2 activation is essential for beta 1 and beta 2 integrin-dependent adhesion of human eosinophils.
J Immunol
163:
3423-3429,
1999