Department of Anesthesia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-4283
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ABSTRACT |
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Interleukin-6 (IL-6) regulates hepatic acute
phase responses by activating the transcription factor signal
transducer and activator of transcription (STAT)-3. IL-6 also may
modulate septic pathophysiology. We hypothesize that
1) STAT-3 activation and transcription of
2-macroglobulin (A2M) correlate
with recovery from sepsis and 2)
STAT-3 activation and A2M transcription reflect intrahepatic and not
serum IL-6. Nonlethal sepsis was induced in rats by single puncture
cecal ligation and puncture (CLP) and lethal sepsis via double-puncture
CLP. STAT-3 activation and A2M transcription were detected at 3-72
h and intrahepatic IL-6 at 24-72 h following single-puncture CLP.
All were detected only at 3-16 h following double-puncture CLP and
at lower levels than following single-puncture CLP. Loss of serum and
intrahepatic IL-6 activity after double-puncture CLP correlated with
mortality. Neither intrahepatic nor serum IL-6 levels correlated with
intrahepatic IL-6 activity. STAT-3 activation following single-puncture
CLP inversely correlated with altered transcription of gluconeogenic, ketogenic, and ureagenic genes. IL-6 may have both beneficial and
detrimental effects in sepsis. Fulminant sepsis may decrease the
ability of hepatocytes to respond to IL-6.
cytokines; tumor necrosis factor-; mortality; multiple organ
dysfunction syndrome; systemic inflammatory response syndrome;
2-macroglobulin
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INTRODUCTION |
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AN IMPORTANT MEDIATOR of the hepatic acute phase
response to inflammation, infection, or injury is interleukin-6 (IL-6)
(4). After an inflammatory stimulus, hepatic secretion of
several acute phase proteins, including the antiprotease
2-macroglobulin (A2M) in the
rat, is increased. The increase in A2M is transcriptionally controlled,
primarily by IL-6 (4). One IL-6-activated nuclear protein transcription
factor that increases A2M transcription is signal transducer and
activator of transcription (STAT)-3 (33). Although cytokines other than
IL-6 can activate STAT-3 (20), studies have shown that STAT-3 is highly
reflective of IL-6 activity in the liver (20).
IL-6 also may be an important modulator of pathological changes in sepsis, the systemic inflammatory response syndrome (SIRS), and the multiple organ dysfunction syndrome (MODS) (7, 8, 12, 13, 16-18, 24, 27). Clinical data, however, are inconclusive. One study has demonstrated a link between serum IL-6 levels and the development of SIRS/MODS (22), but most investigations in sepsis indicate highly variable IL-6 levels (7, 10, 12, 16, 18, 26). In sepsis/SIRS/MODS, liver dysfunction is prominent (25, 29). There are no studies directly linking IL-6 with sepsis-induced hepatic dysfunction. We have recently found that a form of hepatic dysfunction, decreased transcription of key hepatocellular enzymes, is persistent in lethal double-puncture cecal ligation and puncture (CLP) but not in nonlethal single-puncture CLP experimental intra-abdominal sepsis (2, 14). Because IL-6 is essential for recovery and liver regeneration following partial hepatectomy (11, 32), this cytokine might also be important in the prevention of or recovery from sepsis-induced hepatic dysfunction.
The lack of correlation between serum IL-6 levels and outcome from
SIRS/MODS may reflect the fact that cytokines can affect target cells
via three mechanisms: 1) autocrine,
affecting the secreting cell; 2)
paracrine, affecting a nearby cell; and
3) endocrine, affecting a remote
cell. In a nonlethal animal model of sepsis, we have recently shown
that tumor necrosis factor- (TNF-
)-dependent transcription
factor activation and acute phase gene transcription did not correlate
with serum TNF-
levels. Rather, intrahepatic processes appeared to
be mediated by Kupffer-endothelial cell-derived TNF-
(1) and
correlated most directly with activation of a TNF-linked transcription
factor, nuclear factor-
B, and transcription of the TNF-linked acute
phase reactant
1-acid
glycoprotein. Thus to determine the exact role played by IL-6 in
sepsis-induced hepatic dysfunction it would be useful to examine
activation of STAT-3 and transcription of A2M.
In this investigation we examine the role of IL-6 in single- and double-puncture CLP. We postulate that following the nonlethal insult of single-puncture CLP, activation of STAT-3 and transcription of A2M will persist. In contrast, these processes will decrease following double-puncture CLP (fulminant sepsis), a disorder characterized by progressive hepatic dysfunction and death. Furthermore, we hypothesize that intrahepatic IL-6 abundance will be more predictive of STAT-3 activation and A2M transcription than serum levels.
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METHODS |
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Induction of sepsis. All animal studies conform to National Institutes of Health standards for the use of laboratory animals. Overnight-fasted male Sprague-Dawley rats (Charles River, Boston, MA) weighing between 250 and 270 g were used in all experiments. The induction of nonfulminant sepsis was performed under methoxyflurane anesthesia using cecal ligation with a single, 18-gauge puncture (CLP) as previously described (14). Fulminant sepsis similarly was induced by ligating the cecum and then puncturing it twice (3, 31). Sham-operated controls were anesthetized and underwent laparotomy with cecal manipulation but without cecal ligation or puncture. After surgery, animals were fluid resuscitated with 40 ml/kg of subcutaneously administered sterile saline and were given free access to water but not food. At 0, 3, 6, 16, 24, 48, and 72 h following single-puncture CLP or sham operation and at 0, 3, 6, 16, 24, and 48 h after double-puncture CLP, animals were reanesthetized with a 50 mg/kg intraperitoneal injection of pentobarbital. Vena caval blood was obtained, and liver tissue was either harvested for nuclear protein or nuclei, or the entire liver was perfusion fixed with 2% paraformaldehyde.
Isolation and preparation of nuclear extracts. Isolation of nuclear proteins was performed as previously described (14, 15). All procedures were performed at 4°C, and all buffers contained proteinase and phosphatase inhibitors. Briefly, liver tissue was homogenized, nuclei were separated by ultracentrifugation, the nuclear pellet was lysed, and protein was isolated. Protein concentrations were determined using the Bradford method.
Tissue fixation. Livers were perfused via the portal vein with PBS (pH 7.3) for 5 min to remove red cells. This was followed by perfusion for 5 min with 2% paraformaldehyde in PBS (pH 7.3) at a flow rate of 20 ml/min. The perfused liver was excised, cut into slices, and fixed in the paraformaldehyde solution for 2 h at 4°C. Slices were paraffin embedded and cut into 7-µm sections. Sections were adhered to poly-L-lysine-coated glass slides and dried overnight at 37°C.
Electrophoretic mobility shift assay and supershift analysis.
Hepatic nuclear extraction and binding reactions were performed as
previously described with minor modifications (11, 14, 15). Briefly, a
preannealed HPLC-purified oligonucleotide from the
serum-inducible-factor binding element in the
c-fos promoter was end-labeled with
[-32P]ATP and used
as a probe for STAT-3 binding activity. An excess of probe was
incubated with 2.5 µg of nuclear extract plus 1 µg polydeoxyinosinic-deoxycytidylic acid, a nonspecific DNA competitor, for 15 min at room temperature. Other samples were
supershifted by the addition of 3 µl of STAT-3 antibody (Santa Cruz
Biotechnology, Santa Cruz, CA) for 1 h after the addition of labeled
oligonucleotide. In cold competition experiments, unlabeled
oligonucleotide was incubated with nuclear extracts for 15 min before
the addition of radiolabeled probe. Each sample was subjected to
electrophoresis on a 5% nondenaturing polyacrylamide gel. Gels were
then dried, and autoradiography was performed. Radiographic density of
gels containing samples following sham operation, single-puncture CLP, and double-puncture CLP was determined via densitometry. Values at
time 0 were arbitrarily set at unity,
and other results were normalized to this value.
Transcript elongation analysis (nuclear run-on).
Nuclei were isolated, and nuclear run-on was performed using a
modification of a previously reported method (2). All procedures were
performed at 4°C. Briefly, liver tissue was harvested, minced, homogenized in 10 mM Tris · HCl, pH 8.0, 0.3 M
sucrose, 3 mM CaCl2, 2 mM
magnesium acetate, 0.1 mM EDTA, and 0.1 mM phenylmethylsulfonyl fluoride, filtered, and layered onto a cushion buffer containing 50 mM
Tris · HCl, pH 8.0, 2 M sucrose, 5 mM magnesium
acetate, 0.1 mM EDTA, and 0.1 mM phenylmethylsulfonyl fluoride.
Ultracentrifugation was performed at 100,000 g for 30 min. The pellet was
resuspended in 25% glycerol, 5 mM magnesium acetate, 0.1 mM EDTA, and
5 mM dithiothreitol, and stored at 120°C until use.
Nitrocellulose-immobilized targets were prepared using 10 µg each of
plasmids containing A2M and ATP synthase (positive control) cDNAs.
Plasmids without inserts served as negative controls. Two hundred fifty
microliters of 4× reaction mix (100 mM HEPES, pH 7.4, 10 mM
MgCl2, 10 mM dithiothreitol, 300 mM KCl, and 20% glycerol) were combined with 1 mCi
[32P]UTP, 125 µl
8× triphosphate mixture (2.8 mM each ATP, GTP, and CTP;
Boehringer Mannheim, Indianapolis, IN) and diluted to a volume of 500 µl to yield the 2× reaction mixture. For each reaction, 100 µl of thawed nuclei were added to an equal volume of 2×
reaction mixture and incubated at room temperature for 30 min. The
reaction was stopped by adding 2 µl of DNase 1 (10,000 U/ml in 50%
glycerol; Boehringer Mannheim) and incubated at 37°C for 30 min.
Stop buffer (600 µl; 2% SDS, 7 M urea, 350 mM LiCl, 1 mM
EDTA, and 10 mM Tris, pH 8.0), 1,000 µl/ml of proteinase K, and 100 µl of tRNA were added and the mixture was incubated at 40°C for 1 h. The mixture was phenol-chloroform extracted, trichloroacetic acid
precipitated, and ethanol washed. The pellet was resuspended in 100 µl TES (10 mM Tris, 1 mM EDTA, and 0.5% SDS), added to 5 ml of
hybridization solution (see above), and hybridized with the targets at
42°C for 48 h. Targets were washed with 2× saline sodium
citrate (SSC; 0.03 M sodium citrate, pH 7.3, and 0.3 M NaCl) at
65°C for 1 h and then incubated with 10 mg/ml RNase A in 8×
SSC at 37°C for 30 min. Targets were then washed with 2× SSC
at 37°C for 1 h. Targets were autoradiographed for ~5 days at
80°C, and quantitative laser densitometry (Molecular
Dynamics) was performed. Radiographic density was normalized to the
density of ATP synthase. The normalized density at
time 0 was arbitrarily set at unity,
and means ± SD were determined.
Determination of IL-6 levels in vena caval blood. Determinations of IL-6 serum concentrations were performed using an ELISA kit specific for rat IL-6 (BioSource, Camarillo, CA). Plasma samples were assayed in duplicate.
Immunohistochemistry of IL-6 on rat liver sections. Tissue fixation and preparation were performed as previously described (1). The primary incubation was for 2 h at room temperature using a goat anti-rat polyclonal antibody for IL-6 (Santa Cruz Biotechnology). The secondary incubation, also at room temperature, used a biotinylated anti-goat antibody (Vector Laboratories, Burlingame, CA) for 1 h. Chromogenic staining was performed with metal-enhanced diaminobenzidine substrate (Pierce, Rockford, IL) using immunoperoxidase methodology (New England Nuclear, Wilmington, DE).
Statistics. Statistical significance (P < 0.05) was determined using ANOVA for repeated measures with the Bonferroni test of post hoc significance.
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RESULTS |
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Outcome. The clinical response differed among sham operation, single-puncture CLP, and double-puncture CLP. Sham-operated animals recovered from surgery uneventfully. After single-puncture CLP, rats developed mild signs of sepsis as previously described (2, 14). These included lethargy, decreases in spontaneous movement, and poor grooming that resolved by 48 h. In contrast, 8-10 h following double-puncture CLP, animals became severely ill (14). Water intake decreased, there was no spontaneous movement observed, eyes became encrusted, and grooming was absent. By 16 h animals were extremely lethargic and had diarrhea, piloerection, and tachypnea. These signs are characteristic of severe late sepsis.
There were no deaths following sham operation or single-puncture CLP but a significant number of animals died following double-puncture CLP. Six animals were killed following an overnight fast, 36 animals underwent sham operation, 36 underwent single-puncture CLP, and 40 underwent double-puncture CLP. The intention was to kill six animals in each group at each time point (3, 6, 16, 24, 48, and 72 h). No double-puncture animals died before 16 h, but mortality was 50% at 24 h, only three animals survived to 48 h, and none survived to 72 h. Overall mortality in the double-puncture CLP group was 70%. Four extra animals were needed in the double-puncture CLP group so that three animals could be studied at the 48-h time point.STAT-3 activation in liver nuclear extracts via electrophoretic mobility shift assay. Activation of STAT-3, which is believed to correlate directly with intrahepatic IL-6 activity (11), was measured following sham operation, single-puncture CLP, and double-puncture CLP (Fig. 1). No STAT-3 DNA binding activity could be detected in time 0 samples. Low levels of STAT-3 binding (<10% of that detected following single-puncture CLP and <20% of that following double-puncture CLP) were detected 3 h following sham operation. Maximal STAT-3 DNA binding activity was detected 3 h after single-puncture CLP and double-puncture CLP but levels following single-puncture CLP were nearly twice those observed following double-puncture CLP. At all other time points the differences were equally more pronounced. At 6 and 16 h following double-puncture CLP, levels of STAT-3 activity reached a plateau, whereas levels following single-puncture CLP continued to decline. However, levels were 2.5-fold greater in single-puncture CLP than in double-puncture CLP at these time points. No STAT-3 binding activity was detected 24 and 48 h after double-puncture CLP. These data demonstrate that IL-6 activity was more pronounced following single-puncture CLP than following double-puncture CLP, but a sustained elevation was noted following double-puncture CLP.
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A2M transcription in rat liver. Transcription of A2M also provides an indication of intrahepatic IL-6 activity (4). Nuclear run-on was used to determine time-dependent changes in A2M transcription following sham operation, single-puncture CLP, and double-puncture CLP (Fig. 2). After sham operation, we detected a twofold elevation of A2M transcription at 6 h. A2M transcription increased fivefold 3 h after both single- and double-puncture CLP. This mild increase was sustained up to 16 h following double-puncture CLP. Transcription of A2M rose even further following single-puncture CLP, with a maximal 16-fold increase observed at 24 h. Levels then declined. This differed from double-puncture CLP, in which no A2M transcription could be detected at 16, 24, and 48 h. As in previous studies, transcription of ATP synthase was unchanged after single- or double-puncture CLP (1, 14). Although there was no correlation between maximal STAT-3 binding activity and A2M transcription following single-puncture CLP, we detected a temporal correlation between the loss of both STAT-3 binding activity and A2M transcription 24 h after double-puncture CLP.
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Immunohistochemical detection of IL-6 in liver tissue.
Because we have previously shown that intrahepatic TNF- abundance
correlated with activation of a TNF-dependent transcription factor and
expression of a TNF-dependent acute phase reactant (1), we used
immunohistochemistry to see whether a similar correlation existed among
intrahepatic IL-6 abundance, STAT-3 activation, and A2M transcription
(Fig. 3). No IL-6 was detected in the liver at any time point after sham operation. Intrahepatic IL-6
was detected in Kupffer and endothelial cells (Fig. 3, black arrows) at
24, 48, and 72 h following single-puncture CLP. More IL-6 staining was
detected at 48 and 72 h than at 24 h after single-puncture CLP. After
double-puncture CLP, IL-6 was first detected in liver samples 6 and 16 h after the procedure. There was no IL-6 staining at later time points.
We detected no correlation between IL-6 abundance and the magnitude of
either STAT-3 activation or A2M transcription in the liver after
single-puncture CLP. However, the loss of detectable IL-6 in the liver
following double-puncture CLP correlated with the loss of STAT-3
binding activity and A2M transcription
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IL-6 serum concentrations.
Because previous study after single-puncture CLP has indicated that
serum levels of TNF- do not correlate with intrahepatic levels or
activity, we examined IL-6 serum concentrations in vena caval blood
(Fig. 4). Low levels were detectable at
time 0 and following sham operation.
Serum levels after single-puncture CLP were statistically elevated over
time 0 and over sham operation only at
16 h. In contrast, peak serum levels following double-puncture CLP were
statistically increased 6 and 16 h after the insult. Peak levels after
double-puncture CLP were eight times greater than time
0, sham operation, and single-puncture CLP. Levels
decreased to baseline 24 h after double-puncture CLP and were
statistically lower than values for sham operation and single-puncture
CLP at 48 h. Serum IL-6 levels following single-puncture CLP did not correlate with STAT-3 activity, A2M transcription, or intrahepatic IL-6
abundance. Although no correlation was evident at 3, 6, and 16 h, the
abrupt decrease in serum IL-6 levels 24 h after double-puncture CLP
correlated with the loss of STAT-3 binding activity, A2M transcription, and intrahepatic IL-6 abundance.
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DISCUSSION |
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In this study we demonstrate that loss of STAT-3 activity, transcription of A2M, intrahepatic IL-6 abundance, and immunoreactive IL-6 in the serum correlate with mortality in sepsis. We further show that neither serum IL-6 levels nor intrahepatic IL-6 abundance correlate in magnitude or time with two reliable indicators of intrahepatic IL-6 activity, STAT-3 activity, or A2M transcription (4, 11), except in the terminal phase of fulminant sepsis.
This study focuses on the role of IL-6 in hepatic dysfunction during sepsis/SIRS/MODS. Regel et al. (25) have found that the liver is the second most commonly affected organ in MODS, surpassed only by the lung. We have previously characterized early hepatic dysfunction by examining the transcription of a series of liver-specific genes in animal models of sepsis (2, 14). These genes are involved in essential metabolic processes such as gluconeogenesis, ketogenesis, and ureagenesis. In mild sepsis (single-puncture CLP), transcription of these genes decreases and then recovers as the insult resolves. However, transcription of the gluconeogenic enzyme glucose 6-phosphatase does not return to normal in the face of a fulminant, highly lethal septic insult, double-puncture CLP (14). Thus single-puncture CLP is associated with mild, reversible hepatic dysfunction, whereas the alteration associated with double-puncture CLP is irreversible.
Our data indicate that IL-6 is important in mediating two distinct, opposing effects in the liver in sepsis. After single-puncture CLP, IL-6 activity, as measured by STAT-3 activation and A2M transcription, inversely correlates with the sepsis-induced decrease in the transcription of hepatic gluconeogenic, ketogenic, and ureagenic genes. Specifically, the increase in STAT-3 activity and A2M transcription parallel, in magnitude and in time, the decrease in transcription of phosphoenolpyruvate carboxykinase, glucose 6-phosphatase, carnitine palmitoyltransferase, acetyl-CoA acyltransferase, and ornithine transcarbamylase seen after single-puncture CLP (2). Studies in cultured cells and nonseptic animals have demonstrated that IL-6 reduces transcription of phosphoenolpyruvate carboxykinase and glucose 6-phosphatase (9, 21). However, because a STAT binding domain has not been identified in the promoters of any of these genes, it is unlikely that STAT-3 directly mediates the decrease in transcription.
IL-6, via STAT-3 activation, might also mediate hepatic dysfunction by activating a pathway that culminates in cell death, either via necrosis or apoptosis. It is well known that the double puncture model of CLP is associated with the late appearance of hepatic transaminases in the blood, indicative of necrosis (3, 31). Transaminases are not elevated following single-puncture CLP. We have examined apoptosis following both forms of CLP and found that it is indeed increased (L. Bellin, K. M. Andrejko, J. Chen, and C. S. Deutschman, unpublished data).
The correlation between decreased transcription of gluconeogenic, ketogenic, and ureagenic genes and increased IL-6 activity supports the hypothesis that the effects of IL-6 in sepsis are detrimental. However, a second line of evidence indicates that IL-6 activity is beneficial. Between 16 and 24 h following double-puncture CLP, there is a loss of STAT-3 activation, A2M transcription, detectable IL-6 abundance in the liver, and immunoreactive IL-6 in the blood. At this point in time, outcome following single and double-puncture CLP diverges. In previous work, we found that double-puncture CLP persistently decreases the transcription of glucose 6-phosphatase (14). The effect of single-puncture CLP is not persistent, and the difference between the two forms of sepsis becomes apparent 16 h after the original insult (14). Therefore, IL-6 may function as a "recovery factor" from sepsis and modulate the reversal of hepatic dysfunction. Although the mechanism is unknown, IL-6 is essential in hepatic regeneration (11, 32). A similar effect could contribute to recovery from sepsis.
Double-puncture CLP seems to attenuate the hepatocellular response to IL-6. At 6 and 16 h following this fulminant insult, STAT-3 activation and A2M transcription are less than those observed after single-puncture CLP despite higher levels of both intrahepatic and circulating IL-6. This may reflect a change in an intracellular, IL-6-linked pathway or that circulating cytokines do not have access to hepatocytes. Alternatively, the detection of IL-6 by immunohistochemistry may have no functional importance, indicating nothing more than the accumulation of IL-6 in Kupffer and endothelial cells, or normalization of STAT-3 density to values at time 0 may be invalid. The abundance of IL-6 in nonparenchymal cells at 6 and 16 h following double-puncture CLP also could reflect an inability of these cells to secrete cytokines.
Our data also demonstrate a discrepancy between the time course of STAT-3 activation and A2M transcription following single-puncture CLP. Cytokines such as TNF and IL-1 are known to enhance IL-6-induced A2M transcription and activate transcription factors other than STAT-3 (4, 19, 23). Intrahepatic TNF-IL-1 activity peaks later than IL-6 activity (1, 15). The enhancement afforded by this increase could explain increased A2M transcription despite declining STAT-3 activity. Alternatively, Wen et al. (30) have shown that both serine and tyrosine phosphorylation are required for maximal STAT-3 transcriptional activity (30). Thus there may be a difference between maximal DNA binding activity and maximal transcriptional activation.
Another important ramification of this study involves the role of serum
levels of IL-6 (and other cytokines) in sepsis, SIRS, or MODS. In
septic shock, death results from cardiovascular collapse secondary to
vasodilatation. During clinical septic shock or following direct
experimental insults, serum TNF, IL-1, and IL-6 levels may correlate
with pathophysiological changes. However, the mechanism of death in
patients with SIRS/MODS is not shock but progressive dysfunction in
multiple organ systems (5, 13). We have previously shown that
TNF-dependent processes correlate with intrahepatic TNF- abundance
and not with serum TNF-
levels (1). Neither serum nor intrahepatic
IL-6 correlates with two markers of IL-6 activity in sepsis. This
emphasizes that strategies designed to eliminate or block circulating
cytokines are unlikely to be successful.
Perhaps most importantly of all, these data highlight the complex
biology of cytokines such as IL-6 in sepsis. Levels of IL-6, TNF-,
and IL-1 in the circulation during clinical sepsis are highly variable.
Clinical trials designed to neutralize circulating TNF-
or IL-1 have
not altered the outcome from SIRS/MODS (10). We have demonstrated that
intrahepatic IL-6 activity is associated with both detrimental
(decreased transcription of gluconeogenic, ketogenic, and ureagenic
genes) and beneficial (improved outcome) effects during sepsis induced
by CLP. In another cell population in a different setting, similarly
divergent effects have been shown for TNF-
(6, 28). In view of this
a better understanding of the complex nature of cytokine-mediated
responses will be essential to develop successful therapeutic
approaches to sepsis.
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ACKNOWLEDGEMENTS |
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Drs. Linda Greenbaum and Rebecca Taub critically reviewed the manuscript, whereas Drs. Antonio DeMaio (Baltimore, MD) and Mark Clemens (Charlotte, NC) provided the senior author with ongoing instruction and advice. Finally, the authors gratefully acknowledge Drs. David E. Longnecker and Bryan E. Marshall (Dept. of Anesthesia, Univ. of Pennsylvania) for advice, support, and a unique environment of academic opportunity.
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FOOTNOTES |
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This work was supported in part by National Institute of Diabetes and Digestive and Kidney Diseases Grant K08-DK-028179 (C. S. Deutschman).
STAT-3 consensus oligonucleotide was provided by Dr. Rebecca Taub (University of Pennsylvania, Philadelphia, PA). The probe for A2M was obtained from the American Type Culture Collection (Rockville, MD).
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. §1734 solely to indicate this fact.
Address for reprint requests: C. S. Deutschman, Dept. of Anesthesia, Dulles 773/Hospital of the Univ. of Pennsylvania, 3400 Spruce St., Philadelphia, PA.
Received 12 April 1998; accepted in final form 13 August 1998.
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REFERENCES |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
1.
Andrejko, K. M.,
and
C. S. Deutschman.
Acute phase gene expression correlates with intrahepatic tumor necrosis factor- abundance but not plasma TNF levels during sepsis/SIRS in the rat.
Crit. Care Med.
24:
1947-1952,
1996[Medline].
2.
Andrejko, K. M.,
and
C. S. Deutschman.
Altered hepatic gene expression in fecal peritonitis: changes in transcription of gluconeogenic, -oxidative and ureagenic genes.
Shock
7:
164-167,
1997[Medline].
3.
Baker, C. C.,
I. H. Chaudry,
H. O. Gaines,
and
A. E. Baue.
Evaluation of factors affecting mortality rate after sepsis in a murine cecal ligation and puncture model.
Surgery
94:
331-335,
1983[Medline].
4.
Baumann, H.,
and
J. Gauldie.
The acute phase response.
Immunol. Today
15:
74-80,
1994[Medline].
5.
Beal, A. L.,
and
F. B. Cerra.
Multiple organ failure syndrome in the 1990s: systemic inflammatory response and organ dysfunction.
JAMA
271:
226-233,
1994[Abstract].
6.
Beg, A. A.,
and
D. Baltimore.
An essential role for NF-B in preventing TNF-
induced cell death.
Science
274:
782-784,
1996
7.
Blackwell, T. S.,
and
J. W. Christman.
Sepsis and cytokines: current status.
Br. J. Anaesth.
77:
110-117,
1996
8.
Casey, L. C.,
R. A. Balk,
and
R. C. Bone.
Plasma cytokine and endotoxin levels correlate with survival in patients with sepsis syndrome.
Ann. Intern. Med.
119:
771-778,
1993
9.
Christ, B.,
A. Nath,
P. C. Heinrich,
and
K. Jungermann.
Inhibition by recombinant interleukin-6 of the glucagon-dependent induction of phosphoenolpyruvate carboxykinase and the insulin-dependent induction of glucokinase gene expression in cultured rat hepatocytes: regulation of gene transcription and messenger RNA degradation.
Hepatology
20:
1577-1583,
1994[Medline].
10.
Christman, J. W.,
E. P. Holden,
and
T. S. Blackwell.
Strategies for blocking the systemic effects of cytokines in the sepsis syndrome.
Crit. Care Med.
23:
955-963,
1995[Medline].
11.
Cressman, D. E.,
L. E. Greenbaum,
R. A. DeAngelis,
G. Ciliberto,
E. E. Furth,
and
R. Taub.
Liver failure and defective hepatocyte regeneration in interleukin-6 deficient mice.
Science
274:
1379-1383,
1996
12.
Damas, P.,
D. Ledoux,
M. Nys,
Y. Vrindts,
D. De Groote,
P. Franchimont,
and
M. Lamy.
Cytokine serum levels during severe sepsis in humans: IL-6 as a marker of severity.
Ann. Surg.
215:
356-362,
1992[Medline].
13.
Deitch, E. A.
Multiple organ failure: pathophysiology and potential future therapy.
Ann. Surg.
216:
117-134,
1992[Medline].
14.
Deutschman, C. S.,
K. M. Andrejko,
B. A. Haber,
E. Elenko,
R. Harrison,
and
R. Taub.
Sepsis-induced depression of rat glucose-6-phosphatase gene expression and activity.
Am. J. Physiol.
273 (Regulatory Integrative Comp. Physiol. 42):
R1709-R1718,
1997[Medline].
15.
Deutschman, C. S.,
B. A. Haber,
K. Andrejko,
D. E. Cressman,
R. Harrison,
E. Elenko,
and
R. Taub.
Increased expression of cytokine induced neutrophil chemoattractant (CINC) in septic rat liver.
Am. J. Physiol.
271 (Regulatory Integrative Comp. Physiol. 40):
R593-R600,
1996
16.
Dofferhoff, A. S.,
V. J. J. Bom,
H. G. de Vries-Hospers,
J. van Inguen,
J. van der Meer,
B. P. C. Hazenberg,
P. O. M. Mulder,
and
J. Weits.
Patterns of cytokines, plasma endotoxin, plasminogen activator inhibitor and acute phase proteins in severe sepsis.
Crit. Care Med.
20:
185-192,
1992[Medline].
17.
Enayati, P.,
M. F. Brennan,
and
Y. Fong.
Systemic and liver cytokine activation: implications for liver regeneration and posthepatectomy endotoxemia and sepsis.
Arch. Surg.
129:
1159-1164,
1994[Abstract].
18.
Gardlund, B.,
J. Sjolin,
A. Nilsson,
M. Roll,
C.-J. Wickerts,
and
B. Wretlind.
Plasma levels of cytokines in primary septic shock in humans: correlations with disease severity.
J. Infect. Dis.
172:
296-301,
1995[Medline].
19.
Gerhartz, C.,
B. Heesel,
J. Sasse,
U. Hemmann,
C. Landgraf,
J. Schneider-Mergener,
F. Horn,
P. C. Heinrich,
and
L. Graeve.
Differential activation of acute phase response factor/STAT3 and STAT1 via the cytoplasmic domain of the interleukin 6 signal transducer gp130. I. Definition of a novel phosphotyrosine motif mediating STAT1 activation.
J. Biol. Chem.
271:
12991-12998,
1996
20.
Horvath, C. M.,
and
J. E. Darnell, Jr.
The state of the STATs: recent developments in the study of signal transduction to the nucleus.
Curr. Opin. Cell Biol.
9:
233-239,
1997[Medline].
21.
Metzger, S.,
N. Goldschmidt,
V. Barash,
T. Peretz,
O. Drize,
J. Shilyansky,
E. Shiloni,
and
T. Chejek-Shaul.
Interleukin-6 secretion in mice is associated with reduced glucose 6-phosphatase and liver glycogen levels.
Am. J. Physiol.
273 (Endocrinol. Metab. 36):
E262-E267,
1997
22.
Partrick, D. A.,
F. A. Moore,
E. E. Moore,
W. L. Biffl,
A. Sauaia,
and
C. C. J. Barnett.
The inflammatory profile of interleukin-6, interleukin-8 and soluble cell adhesion molecule-1 in post-injury multiple organ failure.
Am. J. Surg.
172:
425-431,
1997.
23.
Piekorz, R. P.,
C. Nemetz,
and
G. M. Hocke.
Members of the family of IL-6-type cytokines activate Stat5a in various cell types.
Biochem. Biophys. Res. Commun.
236:
438-443,
1997[Medline].
24.
Pinsky, M. R. Clinical studies on cytokines in
sepsis: role of serum cytokines in the development of multiple-systems
organ failure. Nephrol. Dial.
Transplant. 9 Suppl.: S94-S98,
1994.
25.
Regel, G.,
M. Grotz,
T. Weltner,
J. A. Strum,
and
H. Tscherne.
Patterns of organ failure following severe trauma.
World J. Surg.
20:
422-429,
1996[Medline].
26.
Tang, G. H.,
C. D. Kuo,
T. C. Yen,
H. S. Kuo,
K. H. Chan,
H. W. Yien,
and
T. Y. Lee.
Perioperative plasma concentrations of tumor necrosis factor-alpha and interleukin-6 in infected patients.
Crit. Care Med.
24:
423-428,
1996[Medline].
27.
Walley, K. R.,
N. W. Lukas,
T. J. Standiford,
R. M. Strieter,
and
S. L. Kunkel.
Balance of inflammatory cytokines related to the severity and mortality of murine sepsis.
Infect. Immun.
64:
4733-4738,
1996[Abstract].
28.
Wang, C.-Y.,
M. W. Mayo,
and
A. S. Baldwin, Jr.
TNF and cancer therapy-induced apoptosis: potentiation by inhibition of NF-B.
Science
274:
784-787,
1996
29.
Wang, P.,
and
I. H. Chaudry.
Mechanism of hepatocellular dysfunction during hyperdynamic sepsis.
Am. J. Physiol.
270 (Regulatory Integrative Comp. Physiol. 39):
R927-R938,
1996
30.
Wen, Z.,
Z. Zhong,
and
J. E. Darnell, Jr.
Maximal activation of transcription by Stat1 and Stat3 requires both tyrosine and serine phosphorylation.
Cell
82:
241-250,
1995[Medline].
31.
Wichterman, K. A.,
A. E. Baue,
and
I. H. Chaudry.
Sepsis and septic shock: a review of laboratory models and a proposal.
J. Surg. Res.
29:
189-210,
1980[Medline].
32.
Yamada, Y.,
I. Kirillova,
J. J. Peschon,
and
N. Fausto.
Initiation of liver growth by tumor necrosis factor: deficient liver regeneration in mice lacking type 1 tumor necrosis factor receptor.
Proc. Natl. Acad. Sci. USA
94:
1441-1446,
1997
33.
Zhang, D.,
M. Sun,
D. Samols,
and
I. Kushner.
STAT3 participates in transcriptional activation of c-reactive protein by interleukin-6.
J. Biol. Chem.
271:
9503-9509,
1996