Download Lisofylline prevents leak, but not neutrophil accumulation, in lungs of

Lisofylline prevents leak, but not neutrophil
accumulation, in lungs of rats given IL-1 intratracheally
BROOKS M. HYBERTSON,1 STUART L. BURSTEN,2 JONATHAN A. LEFF,1
YOUNG M. LEE,1 ERIC K. JEPSON,1 CHRIS R. DEWITT,1 JOHN ZAGORSKI,3
HYUN G. CHO,4 AND JOHN E. REPINE1
1The Webb-Waring Institute for Biomedical Research and the Department of Medicine at the
University of Colorado Health Sciences Center, Denver, Colorado, 80262; 2Cell Therapeutics, Inc.,
Seattle, Washington 98119; 3National Institute of Dental Research, National Institutes of Health,
Bethesda, Maryland 20892; and 4Yeungnam University, Kyungsan 712–749, Korea
cytokines; cytokine-induced neutrophil chemoattractant; acute
respiratory distress syndrome; inflammation; phosphatidic
acid; acute lung injury
INTERLEUKIN-1 (IL-1) is a proinflammatory cytokine that
is increased in lung lavages from patients with acute
edematous lung injury [acute respiratory distress syndrome (ARDS)] (11, 22, 23). Administration of IL-1 also
produces acute lung injury in relevant biological models (9, 10, 12–16, 19, 24, 25). For example, intratracheal
insufflation of IL-1 (50 ng, recombinant human IL-1a)
causes a rapid (5 h) increase in lung lavage cytokineinduced neutrophil chemoattractant (CINC) levels, lung
lavage neutrophil numbers, lung leak, lung histological
abnormalities, lung oxidized glutathione levels, and
exhaled hydrogen peroxide levels in rats (12, 13).
IL-1-induced acute lung leak in rats is reduced by
administering antioxidants, liposomal-prostaglandin E1,
IL-1 receptor antagonist, or polyclonal anti-CINC antibody (10, 12–16).
226
Phospholipid metabolites are emerging as critical signaling messengers, which may not only reflect but also
contribute to acute inflammatory lung injury (3, 20). For
example, treatment with lisofylline [(R)-1-(5-hydroxyhexyl)-3,7-dimethylxanthine (LSF)], which inhibits the
conversion of lysophosphatidic acid to phosphatidic
acid (PA) in vitro, prevented lung injury in mice subjected to hemorrhage and resuscitation (1). LSF treatment abrogated mRNA increases of tumor necrosis
factor-a, IL-1b, interferon-g, and IL-6 in lung cells after
blood loss and resuscitation (1), and also abrogated
mRNA and protein release increases of tumor necrosis
factor-a and IL-1b in lipopolysaccharide-stimulated
blood mononuclear cells but did not affect IL-8 expression (21). Moreover, acyl ratios (oleate1linoleate/
palmitate) were increased in the serum of ARDS patients, and these increases were reduced by treatment
with LSF (3). Because of the similarities between acute
lung injury in ARDS patients and acute lung injury in
rats given IL-1 intratracheally, we studied the effect of
LSF treatment on lung leak and lung neutrophil responses in rats insufflated with IL-1 intratracheally.
MATERIALS AND METHODS
Reagent procurement. Recombinant human IL-1a (endotoxin level ,1 EU/mg) was provided by Dr. Richard Chizzonite of Hoffmann-LaRoche (Nutley, NJ) or purchased from
R&D Systems (Minneapolis, MN), frozen in aliquots, and
thawed daily before use. Methoxyflurane was obtained from
Pitman-Moore (Mundelein, IL), ketamine hydrochloride from
Parke-Davis (Morris Plains, NJ), xylazine from Haver (New
York, NY), 125I-labeled bovine serum albumin from ICN
Radiochemicals (Irvine, CA), and heparin sodium from ElkinsSinn (Cherry Hill, NJ). Polyclonal goat anti-CINC antibody
was provided by J. Zagorski (NIDR, NIH, Bethesda, MD).
CINC [listed as ‘‘IL-8 (Rat)’’] and rabbit anti-CINC antiserum
were obtained from Peptides International (Louisville, KY).
Anti-rabbit immunoglobulin (IgG)-horseradish peroxidase conjugate was obtained from Boehringer-Mannheim (Indianapolis, IN). LSF was obtained from Cell Therapeutics (Seattle,
WA). All other reagents were purchased from Sigma Chemical
(St. Louis, MO).
LSF and IL-1 administration. Male Sprague-Dawley rats
weighing 300–350 g (Sasco, Omaha, NE) were fed a normal
diet and acclimated to Denver altitude for at least 10 days
before study. Initially, rats were injected intraperitoneally
with either LSF in sterile saline (100 mg/kg, 0.6 ml) or sterile
saline. After 15 min, each rat was anesthetized with inhaled
methoxyflurane. Subsequently, the trachea was exposed, a
Teflon catheter was inserted into the trachea, and 50 ng of
IL-1 (in 0.5 ml sterile saline) were rapidly insufflated along
0161-7567/97 $5.00 Copyright r 1997 the American Physiological Society
Downloaded from http://jap.physiology.org/ by 10.220.33.1 on August 1, 2017
Hybertson, Brooks M., Stuart L. Bursten, Jonathan
A. Leff, Young M. Lee, Eric K. Jepson, Chris R. Dewitt,
John Zagorski, Hyun G. Cho, and John E. Repine.
Lisofylline prevents leak, but not neutrophil accumulation, in
lungs of rats given IL-1 intratracheally. J. Appl. Physiol.
82(1): 226–232, 1997.—Interleukin-1 (IL-1) is increased in
lung lavages from patients with the acute respiratory distress
syndrome, and administering IL-1 intratracheally causes
neutrophil accumulation and a neutrophil-dependent oxidative leak in lungs of rats. In the present study, we found that
rats pretreated intraperitoneally with lisofylline [(R)-1-(5hydroxyhexyl)-3,7-dimethylxanthine (LSF)], an inhibitor of
lysophosphatidic acid acyl transferase, which reduces the
production of unsaturated phosphatidic acid species, did not
develop the lung leak or the related ultrastructural abnormalities that occur after intratracheal administration of IL-1.
However, rats pretreated with LSF and then given IL-1
intratracheally did develop the same elevations of lung
lavage cytokine-induced neutrophil chemoattractant (CINC)
levels and the same increased numbers of lung lavage neutrophils as rats given IL-1 intratracheally. Lungs of rats given
IL-1 intratracheally also had increased unsaturated phosphatidic acid and free acyl (linoleate, linolenate) concentrations
compared with untreated rats, and these lipid responses were
prevented by pretreatment with LSF. Our results reveal that
LSF decreases lung leak and lung lipid alterations without
decreasing neutrophil accumulation or lung lavage CINC
increases in rats given IL-1 intratracheally.
LISOFYLLINE AND IL-1-INDUCED ACUTE LUNG INJURY
lungs were ventilated. Subsequently, laparotomy and thoracotomy were performed, and heparin was injected into the
right ventricle (200 U, 0.2 ml). Next, the lungs were perfused
blood free with phosphate-buffered saline, excised, and then
frozen. Lung tissue samples were homogenized and extracted, and lipids were analyzed by high-performance liquid
chromatography (HPLC) as follows. Lipids were extracted
from lung tissue homogenate samples as previously described
(4, 7). Free fatty acids were separated from phospholipids and
purified by normal-phase HPLC by using a Gilson System 45
chromatograph, a Waters µ-Porasil silica column, and a
gradient mobile phase of 1–9% water in hexane-to-isopropanol (3:4, vol/vol) run at a flow rate of 1 ml/min (7, 26).
Phospholipids were quantitated by ultraviolet absorption as
previously described (5). Free fatty acids were quantitated
after collection after HPLC separation (3–4.5 min fraction).
Fatty acids were diluted with methanol, then derivatized
with 9-anthroyldiazomethane (17, 28). A sample of the resultant solution (20 µl) containing derivatized anthroyl free fatty
acids was then analyzed by reverse-phase HPLC. Two reversephase columns were used in series (Spherisorb C8, 5 µm, 4.6
mm 3 25 cm, followed by Spherisorb C18, 3 µm, 4.6 mm 3 15
cm, both from Alltech, Deerfield, IL) to facilitate separation of
both saturated and unsaturated fatty acids. The mobile phase
was an acetonitrile and water gradient (70–100% acetonitrile) at 1 ml/min (2). Both ultraviolet absorption and fluorescence (excitation 305–395 nm, emission 430–470 nm) were
used for detection of separated anthroyl fatty acids (5, 17).
This analytical scheme allowed separation of free fatty acids,
including laurate (C12:0 ), myristate (C14:0 ), myristoleate (C14:1 ),
palmitate (C16:0 ), palmitoleate (C16:1; n-9), heptadecanoate
(C17:0 ), stearate (C18:0 ), oleate (C18:1; n-9), petroselinate (C18:1;
n-6), linoleate (C18:2, n-9,12), a-linolenate (C18:3; n-9,12,15),
d-linolenate (C18:3, n-6,9,12), eicosatrienoate (C18:3 ), and arachidonate (C20:4, n-5, 8,11,14), with interassay coefficient of
variation for the capacity factors ,12%. Fatty acid standards
(Avanti Polar Lipids, Alabaster, AL) were derivatized as
above and used to quantitate samples, with the extraction
efficiencies calculated by using heptadecanoate standards.
The amount of each fatty acid standard recovered was
directly proportional to the amount added in a range from
,40 ng to 10 µg. Intra-assay coefficients of variation for
quantitation of analytes ranged from 12–15% for oleate,
linoleate, and saturated fatty acids to 17–22% for polyunsaturated acids. The practical detection limit was ,34 ng (121
pmol). Fatty acid quantitation was verified by performing
gas-chromatographic separation with mass-spectrometric detection of free fatty acids.
Statistical analyses. Data were analyzed by using a oneway analysis of variance with a Student-Newman-Keuls test
of multiple comparisons. A P value ,0.05 was considered
statistically significant.
RESULTS
Effect of LSF on IL-1-induced lung leak. Rats pretreated with saline and then given IL-1 intratracheally
had an increased (P , 0.05) lung leak index compared
with saline-pretreated rats given saline intratracheally
(Fig. 1A). In contrast, rats pretreated with LSF and
then given IL-1 intratracheally had decreased (P ,
0.05) lung leak compared with saline-pretreated rats
given IL-1 intratracheally (Fig. 1A). Similarly, rats
given IL-1 intratracheally had increased (P , 0.05)
lung lavage fluid protein concentration compared with
untreated control rats (Fig. 1B), and the IL-1-induced
Downloaded from http://jap.physiology.org/ by 10.220.33.1 on August 1, 2017
with two 3-ml puffs of air. Sham-treated rats received identical anesthesia and surgery but were given only sterile saline
intratracheally. The incision was closed and sutured, then
rats were allowed to awaken and were returned to their cages
with free access to food and water.
Lung lavage protein and neutrophil measurement. Five
hours after intratracheal insufflation of IL-1, rats were
anesthetized with ketamine (90 mg/kg) and xylazine (7 mg/kg)
intraperitoneally, and the trachea was cannulated. Subsequently, saline (3.0 ml 3 2) was slowly injected intratracheally and then withdrawn. The volume of lung lavage
recovered (,4.5 ml) was similar from each rat. Recovered
lavage was then centrifuged (1,200 g, room temperature) for 5
min, and the supernatant was collected for analysis of total
protein and CINC levels. Lung lavage protein levels were
determined by protein reduction of alkaline Cu (II) to Cu (I)
and subsequent complexation of Cu (I) with bicinchoninic
acid to form a chromophore that was detected spectrophotometrically at 562 nm (protein-determination kit, Sigma
Chemical). After the leukocyte pellet was resuspended in 1.0
ml of saline, leukocytes were counted in a hemacytometer,
and a cytospin preparation (Shandon Southern Products,
Cheshire, UK) was Wright-stained and differentially counted
to determine the percentage of neutrophils.
CINC assay. CINC concentrations in lung lavage supernatants were measured by sandwich enzyme-linked immunosorbent assay by using goat anti-CINC IgG as capture antibody,
rabbit anti-CINC antisera as secondary antibody, and antirabbit IgG-horseradish peroxidase conjugate with o-phenylenediamine substrate for detection (27).
Lung leak measurement. In separate experiments, 4.5 h
after IL-1 insufflation, rats were anesthetized with ketamine
and xylazine intraperitoneally and then injected with 125Ibovine serum albumin (1 µCi, 0.5 ml) intravenously. After an
additional 30 min, the trachea was cannulated, and the rats
were ventilated. Immediately thereafter, laparotomy and
thoracotomy were performed, and heparin was injected into
the right ventricle (200 U, 0.2 ml). Blood samples were
obtained (1 ml), and the lungs were perfused blood free with
phosphate-buffered saline before excision. The right lungs
and blood samples were counted in a gamma counter (Beckman, Fullerton, CA), and the lung leak index was determined
by computing the counts per minute of 125I in the right lung
divided by counts per minute of 125I in 1.0 ml of blood (lung
leak index).
Lung morphology evaluation. In separate experiments, 5 h
after IL-1 insufflation, rats were anesthetized with ketamine
and xylazine intraperitoneally; then the chest was opened,
lungs were removed, and small blocks of tissue (,1 mm3 )
were fixed by immersion in cold glutaraldehyde solution (1 h,
4°C, 2.5% glutaraldehyde). Air was removed from the tissue
by capping the sample vial and applying a small vacuum with
a 50-ml syringe. After fixation, samples were rinsed and
stored overnight in 0.1 M potassium phosphate buffer, pH 7.4.
Next, samples were postfixed with 1% osmium tetroxide in
0.1 M potassium phosphate buffer for 2 h at room temperature, dehydrated through a graded series of ethanol to
propylene oxide, and embedded in Epon 812 resin. Block
sections, 60–80 nm thick, were cut with a diamond knife by
using a Sorval MT-7000 ultramicrotome and then stained
with uranyl acetate and lead citrate. Sections were examined
by using a Hitachi H-600 transmission electron microscope at
75 kV.
Lung tissue lipid and fatty acid analysis. In separate
experiments, 5 h after IL-1 insufflation, rats were anesthetized with ketamine and xylazine intraperitoneally, blood
(3 ml) was collected, the trachea was cannulated, and the
227
228
LISOFYLLINE AND IL-1-INDUCED ACUTE LUNG INJURY
Fig. 1. Effect of lisofylline (LSF) on lung leak in rats 5 h after
intratracheal insufflation of interleukin-1 (IL-1). Lung leak index
was increased (P , 0.05) in saline-pretreated rats given IL-1 intratracheally, compared with saline-pretreated rats given saline intratracheally (A). Notably, rats pretreated with LSF and then given IL-1
intratracheally had decreased (P , 0.05) lung leak compared with
rats pretreated with saline and then given IL-1 intratracheally (A).
Similarly, lung lavage fluid protein levels were increased (P , 0.05)
by intratracheal insufflation of IL-1, and IL-1-induced lung lavage
fluid protein elevation was attenuated (P , 0.05) by pretreatment
with LSF (B). Each value is mean 6 SE of no. of determinations
shown in parentheses within each bar.
lavage fluid protein increase was attenuated (P , 0.05)
by pretreatment with LSF (Fig. 1B).
Effect of LSF on IL-1-induced lung lavage neutrophil
accumulation. The number of neutrophils recovered in
lung lavages from rats pretreated with saline and then
given IL-1 intratracheally was significantly greater
(P , 0.05) than in saline-pretreated rats given saline
intratracheally (Fig. 2). Rats pretreated with LSF and
then given IL-1 intratracheally had the same (P . 0.05)
lung lavage neutrophil counts as saline-pretreated rats
given IL-1 intratracheally (Fig. 2).
Effect of LSF on IL-1-induced lung lavage CINC
increases. Saline-pretreated rats given IL-1 intratracheally had increased (P , 0.05) concentrations of
CINC in their lung lavages compared with salinepretreated rats insufflated with saline (Fig. 3). Rats
pretreated with LSF and then given IL-1 intratracheally had the same (P . 0.05) CINC protein concentration levels in their lung lavages as saline-pretreated
rats given IL-1 intratracheally (Fig. 3).
Effect of LSF on IL-1-induced lung morphological
abnormalities. Neutrophil infiltration and lung tissue
abnormalities were evident in lung sections from rats
given IL-1 intratracheally (Fig. 4B), compared with
lung sections from saline-pretreated rats (Fig. 4A). In
particular, lung sections from rats given IL-1 intratracheally exhibited neutrophil accumulation, thinning
and disruption of the basement membrane, blebbing of
cells on the alveolar epithelial surface, and swelling of
endothelial cells. By comparison, rats pretreated with
LSF and then given IL-1 intratracheally had comparable pulmonary neutrophil infiltration but less injury
compared with saline-pretreated rats given IL-1 intratracheally (Fig. 4C).
Effect of LSF on IL-1-induced unsaturated lung tissue PA levels. Saline-pretreated rats given IL-1 intratra-
Fig. 3. Effect of LSF on lung lavage fluid cytokine-induced neutrophil
chemoattractant (CINC) levels in rats 5 h after intratracheal insufflation of IL-1. CINC levels were increased (P , 0.05) in salinepretreated rats given IL-1 intratracheally, compared with salinepretreated rats given saline intratracheally. Pretreatment of rats
with LSF did not decrease (P . 0.05) CINC increases in lung lavages
after IL-1 insufflation. Each value is mean 6 SE of no. of determinations shown in parentheses within each bar.
Downloaded from http://jap.physiology.org/ by 10.220.33.1 on August 1, 2017
Fig. 2. Effect of LSF on lung lavage neutrophil numbers in rats 5 h
after intratracheal insufflation of IL-1 (50 ng). No. of lung lavage
neutrophils was increased (P , 0.05) in saline-pretreated rats given
IL-1 intratracheally, compared with saline-pretreated rats given
saline intratracheally. Pretreatment of rats with LSF did not decrease (P . 0.05) IL-1-induced accumulation of neutrophils in lung
lavage. Each value is mean 6 SE of no. of determinations shown in
parentheses within each bar.
LISOFYLLINE AND IL-1-INDUCED ACUTE LUNG INJURY
229
Downloaded from http://jap.physiology.org/ by 10.220.33.1 on August 1, 2017
Fig. 4. Effect of LSF on lung morphology abnormalities
in rats 5 h after intratracheal insufflation of IL-1. A:
well-preserved endothelial cell (Endo) and basement
membrane (BM) structure in lung tissue from rats given
saline intratracheally (original magnification 35,000).
B: lung tissue after intratracheal insufflation of IL-1;
neutrophils (Neutr) are visible in vascular lumen, there
is also thinning of basement membrane and swelling of
endothelial cells (original magnification 34,000, left).
Furthermore, blebbing (*) was visible on alveolar epithelial surface, and basement membrane was disrupted
(arrowhead; original magnification 36,000; right). C: lung
tissue from a rat given LSF pretreatment before IL-1
insufflation; neutrophils are present in vascular lumen,
but cellular damage, including thinning or disruption of
basement membrane, swelling of endothelial cells, and
blebbing of alveolar epithelial surface, was not observed
(original magnification 35,000).
230
LISOFYLLINE AND IL-1-INDUCED ACUTE LUNG INJURY
Downloaded from http://jap.physiology.org/ by 10.220.33.1 on August 1, 2017
cheally had increased (P , 0.05) lung tissue unsaturated PA contents compared with saline-pretreated
rats given saline intratracheally (Fig. 5A). This finding
was confirmed by measuring the unsaturated fatty acid
content of the hydrolyzed PA fraction, which revealed
an increase (P , 0.05) in linoleoyl and linolenoyl mass
of .300% in the isolated lung PA fraction. In contrast,
rats pretreated with LSF before intratracheal IL-1
insufflation had decreased unsaturated PA in lung
tissue, compared with saline-pretreated rats given IL-1
intratracheally (Fig. 5A). In these circumstances, linoleoyl or linolenoyl acyl chains did not increase in the
hydrolyzed lung tissue PA fraction.
Effect of LSF on free unsaturated C18 acid contents in
lung tissue. Similar to the unsaturated PA content
data, saline-pretreated rats given IL-1 intratracheally
had increased (P , 0.05) levels of free linoleoyl (Fig. 5B)
and linolenoyl (a1d) (Fig. 5C) fatty acids in their lung
tissue, compared with saline-pretreated rats subsequently given saline intratracheally. Pretreatment with
LSF decreased both free linoleate (P , 0.05, Fig. 5B)
and free linolenate (P , 0.05, Fig. 5C) fatty acid levels,
increased in lung tissue of rats given IL-1 intratracheally.
DISCUSSION
We found that intraperitoneal pretreatment with
LSF decreased the development of acute lung leak in
rats subsequently given IL-1 intratracheally. Rats given
IL-1 intratracheally had elevated lung leak indexes
and lung lavage fluid protein levels, and these increases were attenuated by pretreatment with LSF.
Remarkably, however, LSF pretreatment decreased
neither IL-1-induced CINC levels nor lavage-recoverable neutrophil accumulation in the lung. Because
neutrophil-dependent processes cause lung leak after
IL-1 administration intratracheally (10, 12–16, 19),
this finding suggests that LSF decreases lung leak by
some mechanism other than simply decreasing the
number of neutrophils recruited to the lung. One
possibility is that LSF protects the lung intrinsically
against oxidative stress, an assumption that is supported by other data that reveal that LSF treatment
reduces leak in isolated rat lungs perfused with xanthine oxidase-generated O2 radicals (D. M. Guidot,
personal communication).
Because IL-1-induced lung leak involves oxidative
mechanisms and because LSF does not scavenge superoxide anion radical in vitro, LSF may confer protection,
at least in part, by altering lung susceptibility to
oxidants. This latter premise is also tenable because
lipid membranes are prime targets for oxidant attack
in the lung. In addition, IL-1 administration increases
the relative concentration of unsaturated to saturated
lung lipid species, making the lung more susceptible to
oxidative stress, and lungs treated with LSF did not
develop these IL-1-induced alterations in unsaturated
acyl chain content and presumably might be more
resistant to oxidative stress. An alternate possibility is
that LSF inhibits neutrophil function, but this postulate is not supported by two related experiments. First,
Fig. 5. Effect of LSF on levels of unsaturated phosphatidic acid (PA)
and free unsaturated fatty acids in lung tissue 5 h after intratracheal
insufflation of IL-1. Saline-pretreated rats given IL-1 intratracheally
had increased (P , 0.05) lung unsaturated PA content compared with
saline-pretreated rats given saline intratracheally, but rats pretreated with LSF before intratracheal IL-1 insufflation had decreased
(P , 0.05) unsaturated PA in lung tissue, compared with salinepretreated rats given IL-1 intratracheally (A). Saline-pretreated rats
given IL-1 intratracheally had increased (P , 0.05) levels of free
linoleoyl (B) and linolenoyl (a1d) (C) fatty acids in lung tissue,
compared with saline-pretreated rats given saline intratracheally.
Pretreatment with LSF attenuated (P , 0.05) both free linoleate (B)
and free linolenate (C) fatty acid levels in lung tissue from rats given
IL-1 intratracheally. Each value is mean 6 SE of no. of determinations shown in parentheses within each bar.
LISOFYLLINE AND IL-1-INDUCED ACUTE LUNG INJURY
We gratefully acknowledge the assistance of Jacqueline Smith
Evans in manuscript preparation.
All work was performed during the tenure of B. M. Hybertson’s
Fellowship in pulmonary research from the Parker B. Francis
Foundation and was supported in part by grants from the National
Heart, Lung, and Blood Institute (SCOR HL-40784), Cell Therapeutics, Inc., Ronald McDonald Children’s Charities, Swan Foundation,
and Newborn Hope.
S. L. Bursten is employed by Cell Therapeutics, Inc. and J. E.
Repine is a former consultant for Cell Therapeutics, Inc., the maker
of lisofylline. Both have stock options in Cell Therapeutics, Inc.
Address for reprint requests: B. M. Hybertson, Webb-Waring
Institute for Biomedical Research, 4200 East Ninth Ave., Box C-322,
Denver, CO 80262 (E-mail: [email protected]).
Received 10 May 1996; accepted in final form 19 September 1996.
REFERENCES
1. Abraham, E., S. Bursten, R. Shenkar, J. Allbee, R. Tuder, P.
Woodson, D. M. Guidot, G. Rice, J. W. Singer, and J. E.
Repine. Phosphatidic acid signaling mediates lung cytokine
expression and lung inflammatory injury after hemorrhage in
mice. J. Exp. Med. 181: 569–575, 1995.
2. Aveldano, M. I., M. VanRollins, and L. A. Horrocks. Separation and quantitation of free fatty acids and fatty acid methyl
esters by reverse phase high-pressure liquid chromatography. J.
Lipid Res. 24: 83–93, 1983.
3. Bursten, S. L., D. A. Federighi, P. E. Parsons, W. E. Harris,
E. E. Moore, F. A. Moore, J. W. Singer, and J. E. Repine.
Ratio of serum linoleate, oleate, and palmitate as predictors of
adult respiratory distress syndrome in patients with sepsis and
trauma. Crit. Care. Med. 24: 1129–1136, 1996.
4. Bursten, S. L., and W. E. Harris. Rapid activation of phosphatidate phosphohydrolase in mesangial cells by lipid A. Biochemistry 30: 6195–6203, 1991.
5. Bursten, S. L., and W. E. Harris. Interleukin-1 stimulates
phosphatidic acid-mediated phospholipase D activity in human
mesangial cells. Am. J. Physiol. 266 (Cell Physiol. 35): C1093–
C1104, 1994.
6. Bursten, S. L., R. Weeks, J. West, T. Le, T. Wilson, D.
Porubek, J. A. Bianco, J. W. Singer, and G. C. Rice. Potential
role for phosphatidic acid in mediating the inflammatory responses to TNF alpha and IL-1 beta. Circ. Shock 44: 14–29, 1994.
7. Folch, J., M. Lees, and G. H. Sloane-Stanley. Simple method
for the isolation and purification of total lipids from animal
tissues. J. Biol. Chem. 226: 497–509, 1957.
8. Guidot, D. M., G. C. Rice, J. W. Singer, S. Bursten, J. A.
Bianco, E. Abraham, and J. E. Repine. Inhibition of lysophosphatidic acid acyl transferase (LPAAT) activity by CT1501R
suppresses neutrophil adherence and chemotaxis in vitro and
decreases interleukin-8 (IL-8)-induced injury in isolated rat
lungs perfused with human neutrophils (Abstract). Clin. Res. 42:
145, 1994.
9. Guidot, D. M., E. E. Stevens, M. J. Repine, A. E. LuccaBroco, and J. E. Repine. Intratracheal but not intravascular
interleukin-1 causes acute edematous injury in isolated neutrophil-perfused rat lungs through an oxygen radical mediated
mechanism. J. Lab. Clin. Med. 12: 605–609, 1994.
10. Hybertson, B. M., J. A. Leff, C. J. Beehler, P. C. Barry, and
J. E. Repine. Effect of vitamin E deficiency and supercritical
fluid aerosolized vitamin E supplementation of interleukin1-induced oxidative lung injury in rats. Free Radical Biol. Med.
18: 537–542, 1995.
11. Jacobs, R. F., D. R. Tabor, A. W. Burks, and G. D. Campbell.
Elevated interleukin-1 release by human alveolar macrophages
during the adult respiratory distress syndrome. Am. Rev. Respir.
Dis. 140: 1686–1692, 1989.
12. Koh, Y., B. M. Hybertson, E. K. Jepson, O. J. Cho, and J. E.
Repine. Cytokine-induced neutrophil chemoattractant is necessary for interleukin-1-induced lung leak in rats. J. Appl. Physiol.
79: 472–478, 1995.
13. Leff, J. A., J. W. Baer, M. E. Bodman, J. M. Kirkman, P. F.
Shanley, L. M. Patton, C. J. Beehler, J. M. McCord, and J. E.
Repine. Interleukin-1-induced lung neutrophil accumulation
and oxygen metabolite-mediated lung leak in rats. Am. J.
Physiol. 266 (Lung Cell. Mol. Physiol. 10): L2–L8, 1994.
14. Leff, J. A., J. W. Baer, J. M. Kirkman, M. E. Bodman, P. F.
Shanley, O. J. Cho, M. J. Ostro, and J. E. Repine. Liposomeentrapped PGE1 posttreatment decreases IL-1a-induced neutrophil accumulation and lung leak in rats. J. Appl. Physiol. 76:
151–157, 1994.
15. Leff, J. A., M. E. Bodman, O. J. Cho, S. Rohrbach, O. K.
Reiss, J. L. Vannice, and J. E. Repine. Post-insult treatment
with interleukin-1 receptor antagonist decreases oxidative lung
injury in rats given intratracheal interleukin-1. Am. J. Respir.
Crit. Care Med. 150: 109–112, 1994.
16. Leff, J. A., C. P. Wilke, B. M. Hybertson, P. F. Shanley, C. J.
Beehler, and J. E. Repine. Postinsult treatment with N-acetylL-cysteine decreases IL-1-induced neutrophil influx and lung
leak in rats. Am. J. Physiol. 265 (Lung Cell. Mol. Physiol. 9):
L501–L506, 1993.
17. Nakaya, T., T. Tomomoto, and M. Imoto. The syntheses and
the reactions of 9-anthroyldiazomethane and a-naphthyldiazomethane. Bull. Chem. Soc. Jpn. 40: 691–692, 1967.
19. Repine, J. E. Interleukin-1-mediated acute lung injury and
tolerance to oxidative injury. Environ. Health Persp. 102: 75–78,
1994.
20. Rice, G. C., P. A. Brown, R. J. Nelson, J. A. Bianco, J. W.
Singer, and S. Bursten. Protection from endotoxic shock in
mice by pharmacologic inhibition of phosphatidic acid. Proc.
Natl. Acad. Sci. USA 91: 3857–3861, 1994.
21. Rice, G. C., J. Rosen, R. Weeks, J. Michnick, S. Bursten,
J. A. Bianco, and J. W. Singer. CT-1501R selectively inhibits
induced inflammatory monokines in human whole blood ex vivo.
Shock 1: 254–266, 1994.
22. Siler, T. M., J. E. Swierkosz, T. M. Hyers, A. A. Fowler, and
R. O. Webster. Immunoreactive interleukin-1 in bronchoalveolar lavage fluid of high-risk patients and patients with the adult
respiratory distress syndrome. Exp. Lung Res. 15: 881–894,
1989.
Downloaded from http://jap.physiology.org/ by 10.220.33.1 on August 1, 2017
LSF treatment did not decrease neutrophil oxidative
burst in vitro (1). Second, LSF-pretreated neutrophils
injured isolated rat lungs given IL-8 intratracheally
(8).
Although PA species have been implicated in lipid
signaling pathways and cytokine expression (1, 6, 21),
our work shows that LSF prevented IL-1-induced lung
leak without reducing IL-1-induced lung lavage CINC
level increases or pulmonary neutrophil accumulation.
Similarly, it was previously found that LSF does not
inhibit IL-8 expression in blood mononuclear cells
stimulated with lipopolysaccharides (21). Thus, it appears that the mechanism of protection by LSF treatment against IL-1-induced lung injury was due, at least
in part, to alteration of cell membrane fatty acid
composition to a less oxidant-susceptible makeup. Chemokine (CINC) signaling and neutrophil accumulation
in the lungs of IL-1-treated rats, on the other hand,
were not decreased by treatment with LSF.
Because acute lung injury in ARDS patients is associated with pulmonary cytokine production, neutrophil
accumulation, and release of reactive oxygen metabolites, our findings are relevant to potential mechanisms
and the treatment of patients with ARDS. Therapeutic
strategies that stabilize lung tissue against inflammation-related injury without causing systemic suppression of the inflammatory response could provide pulmonary protection while preserving related host defense
mechanisms against infection.
231
232
LISOFYLLINE AND IL-1-INDUCED ACUTE LUNG INJURY
23. Suter, P. M., S. Suter, E. Girardin, P. Roux-Lombard, G. E.
Grau, and J. Dayer. High bronchoalveolar levels of tumor
necrosis factor and its inhibitors, interleukin-1, interferon, and
elastase, in patients with adult respiratory distress syndrome
after trauma, shock, or sepsis. Am. Rev. Respir. Dis. 145: 1016–
1022, 1992.
24. Tang, G., J. E. White, P. D. Lumb, D. A. Lawrence, and M. F.
Tsan. Role of endogenous cytokines in endotoxin- and interleukin1-induced pulmonary inflammatory response and oxygen tolerance. Am. J. Respir. Cell Mol. Biol. 12: 339–344, 1995.
25. Ulich, T. R., L. R. Watson, S. M. Yin, K. Z. Guo, P. Wang, H.
Thang, and J. del Castillo. The intratracheal administration
of endotoxin and cytokines. I. Characterization of LPS-induced
IL-1 and TNF mRNA expression and the LPS-, IL-1-, and
TNF-induced inflammatory infiltrate. Am. J. Pathol. 138: 1485–
1496, 1991.
26. Van Kessel, W. S., W. M. Hax, R. A. Demel, and J. De Gier.
High-performance liquid chromatographic separation and direct
ultraviolet detection of phospholipids. Biochim. Biophys. Acta
486: 524–530, 1977.
27. Wittwer, A. J., L. S. Carr, J. Zagorski, G. J. Dolecki, B. A.
Crippes, and J. E. De Larco. High-level expression of cytokineinduced neutrophil chemoattractant (CINC) by a metastatic rat
cell line: purification and production of blocking antibodies. J.
Cell. Physiol. 156: 421–427, 1993.
28. Yoshida, T., A. Uetake, H. Yamaguchi, N. Nimura, and T.
Kinoshita. New preparation method for 9-anthryldiazomethane
(ADAM) as a fluorescent labeling reagent for fatty acids and
derivatives. Anal. Biochem. 173: 70–74, 1988.
Downloaded from http://jap.physiology.org/ by 10.220.33.1 on August 1, 2017