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RECEPTORS AND SIGNAL TRANSDUCTION
Center for Surgical Research and Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama
Submitted 16 February 2006 ; accepted in final form 24 March 2006
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ABSTRACT |
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 TOP ABSTRACT MATERIALS AND METHODSRESULTSDISCUSSIONGRANTSREFERENCES |
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innate immunity; macrophages; cell signaling
There is growing evidence that Kupffer cells play a critical role in regulating immune functions following trauma (25, 29). Located in the liver sinusoids, Kupffer cells represent the largest population of tissue-fixed macrophages in the body and play a key role in the recognition and eventual clearance of bacteria from the blood (46). Once exposed to and activated by pathogens, they are known to produce increased amounts of interleukin-6 (IL-6), IL-10, and monocyte chemoattractant protein-1 (MCP-1), and thus Kupffer cells are a major source of the systemic levels of these cytokines (17, 39). One major mechanism involved in the production of these mediators of inflammation is the activation of mitogen-activated protein kinases (MAPK) (10).
Src kinases are a family of nonreceptor protein tyrosine kinases (PTK) that are expressed either ubiquitously or predominantly in specific immune competent cells. Their activation is achieved by either phosphorylation of Tyr416, dephosphorylation of Tyr527 or the association with different receptors such as growth factor receptors (6). The Src kinases family members such as p56lck, p59fyn, Hck, and Src have been implicated in playing roles in signaling pathways following trauma such as Akt phosphorylation (20), STAT3 phosphorylation (13), and Ras activation (47). Recent studies (43) have also shown their involvement in activating MAPK. Three major isoforms of MAPK, p38, ERK1/2, and JNK, are implicated in the regulation of several immune cell functions. Because MAPK are also involved in the production of cytokines by Kupffer cells, we hypothesized that MAPK signaling in murine Kupffer cells following hypoxia is, at least in part, activated through Src family kinases. To test this hypothesis, a group of animals was treated with Src inhibitor PP1 and the effect of this treatment on Kupffer cell MAPK activation as well as the production of IL-6 and MCP-1 was determined following hypoxia. In this regard, PP1 has been shown to inhibit Src family kinases in previous studies (2, 23, 26). Our findings from these experiments suggest that Src family kinases also likely regulate p38-mediated IL-6 production following hypoxia.
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MATERIALS AND METHODS |
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Murine model of hypoxia.
The hypoxia model used in this experiment was described in detail by Ertel et al. (17). Briefly, mice were fasted overnight but allowed water ad libitum before the procedure. The animals were placed in two plastic chambers (20 x 10 x 8 cm), each with an inlet and outlet, through which the hypoxic gas mixture or room air flowed. Hypoxia was induced by flushing one of the chambers with a gas mixture of 95% N2-5% O2 at a flow rate of 5 l/min for 60 min. At the same time, control (normoxic) animals were kept in the second chamber, which was flushed with room air for 60 min. The animals were constantly monitored during this period, and no immediate or late mortality was observed with this hypoxia model. Previous studies (17, 33) using this murine hypoxia model have shown that in male mice, arterial PO2 decreased to 
40 mmHg within 10 min of hypoxia, remained at that level throughout the duration of hypoxia, but returned to a baseline of 120 mmHg within minutes after the end of hypoxia. The mice were symptomatic for hypoxia, displaying rapid shallow breathing and minimal physical activity.
In a separate experiment, animals received an intraperitoneal injection of PP1 (Biomol, Plymouth Meeting, PA) or PP2 (Calbiochem, La Jolla, CA) each of which was dissolved in DMSO and further diluted in phosphate-buffered saline. The dosage used for both compounds was 1.5 mg/kg body wt and each was administered 1 h before hypoxia. An intraperitoneal injection in mice of appropriately diluted DMSO in PBS vehicle (GIBCO Invitrogen, Carlsbad, CA) served as the vehicle control.
Harvesting procedures. The animals were anesthetized with isoflurane and euthanized 1 h after normoxia or hypoxia. Blood was obtained via cardiac puncture using a syringe coated with EDTA (Sigma, St. Louis, MO). Blood was centrifuged (10,000 rpm, 10 min, 4°C) and the plasma stored at –80°C until analyzed. The liver was flushed to remove cellular blood components by a retrograde perfusion with 20 ml of ice-cold Hanks’ balanced salt solution (HBSS; GIBCO, Grand Island, NY) through the portal vein. This was immediately followed by perfusion with 15 ml of 0.05% collagenase class IV (Worthington Biochemical, Lakewood, NJ) in HBSS at 37°C. The liver was removed en bloc and transferred to a petri dish containing warm enzyme HBSS.
Preparation of Kupffer cells. Kupffer cells were isolated as described previously, with some modification (40). In brief, the perfused liver was minced finely, incubated at 37°C for 15 min, and passed through a sterile 150-mesh stainless steel screen into a beaker containing 10 ml of cold HBSS and 10% FBS (low endotoxin, GIBCO). The hepatocytes were then removed by low-speed centrifugation at 50 g for 3 min, and the residual cell suspension was centrifuged twice at 400 g, 4°C for 10 min. The supernatant was discarded and the cell pellet was resuspended in Complete medium [Williams E medium containing 10% heat-inactivated FBS and 100 U/ml penicillin, 100 µg/ml streptomycin, and 5 µg/ml gentamicin (all from GIBCO)]. The cell suspension was then layered over 14% Histodenz (Sigma-Aldrich) in HBSS and centrifuged at 3,000 g, 4°C, for 45 min to separate the Kupffer cells (which form a band at the Histodenz cushion interface) from the remaining parenchymal cells in the pellet. After the nonparenchymal cells were removed from the interface with a Pasteur pipette, the cells were washed twice by centrifugation (800 g, 10 min, 4°C) in complete medium and adjusted to a final concentration of 5 x 106/ml in complete medium. One hundred microliters of this suspension were then transferred to each well of a 96-well tissue culture plate (6.4 mm well diameter) and the cells were allowed to adhere to the plastic surface at 37°C, 5% CO2, and 95% humidity for 2 h. Nonadherent and nonviable cells were then removed by three repeated washings. This protocol provides adherent cells that are 96% positive by nonspecific esterase staining and that exhibit typical macrophage morphology (48).
Cell extract preparation. For protein immunoblotting, the adherent Kupffer cells were lysed with 100 µl/5 x 105 cells of ice-cold lysis buffer (150 mM NaCl, 1 mM MgCl2, 50 mM HEPES, 1 mM EDTA, 0.5% Triton X-100, 10% glycerol, 200 µM sodium orthovanadate, 100 mM sodium fluoride, 10 mM sodium pyrophosphate, 200 µM phenylmethylsulfonyl fluoride, 520 µM AEBSF, consisting of 400 nM aprotinin, 10 µM leupeptin, 20 µM bestatin, 7.5 µM pepstatin A, 7 µM E-640 for 60 min at 4°C. Cell lysates were centrifuged at 13,000 rpm for 10 min at 4°C. Supernatants were stored at –80°C until further analysis.
Western blot analysis. Cell extracts (8 µg protein per lane) were electrophoretically separated on 10% sodium dodecyl sulfate-polyacrylamide gels, as described previously (34). Proteins were electroblotted to Immobilon-P membranes (GE Healthcare, Waukesha, WI) using a semidry transblot system (Bio-Rad, Hercules, CA) at 11 V for 45 min. Blots were then blocked for 2 h at room temperature with 5% nonfat dry milk in 50 mM Tris·HCl (pH 7.5), 200 mM NaCl, and 0.05% Tween 20 (TBST). After two 5-min washes with TBST, membranes were incubated overnight at 4°C with antibodies to phosho-Src Family (Tyr416), phospho-p38 MAPK (Thr180/Tyr182), phospho-p44/42 (phospho-ERK1/2) MAPK (Thr202/Tyr204), phosho-JNK MAPK (Thr183/Tyr185), nonphospho-Src, nonphospho-p38 MAPK, nonphospho-p44/42 (ERK1/2) MAPK, and nonphospho-JNK MAPK (Cell Signaling Technology, Beverly, MA), diluted 1:1,000 in TBST containing 0.5% nonfat dry milk. After subsequent washes with TBST, the membranes were incubated for 1 h with horseradish peroxidase-conjugated goat anti-rabbit or goat anti-mouse secondary antibody (Bio-Rad), diluted 1:5,000.
Membranes were developed with the use of an enhanced chemiluminescence reagent (GE Healthcare), followed by exposure to Biomax light film (Kodak, Rochester, NY). After the film was developed, Western blots were evaluated by densitometric analysis using Ambis optical imaging system (Ambis Systems, San Diego, CA).
Cytokine analysis. The adherent cells were cultured to asses their cytokine production capacity. After 24 h in culture, cell-free supernatants were harvested. The concentrations of IL-6, IL-10, and MCP-1 in these supernatants were measured by commercially available CBA Mouse Inflammation Kits (BD Pharmingen, San Diego, CA), according to the manufacturer’s instructions. Briefly, 50 µl of mixed capture beads were incubated with 50 µl of supernatant and 50 µl of PE detection reagent for 2 h at room temperature. The immunocomplexes were then washed and analyzed using the LSRII flow cytometer (BD Biosciences, Mountain View, CA). Data processing was carried out using the accompanying FACSDiva and BD CBA software.
In a separate experiment, Kupffer cells were obtained from healthy animals and treated with MAPK inhibitors to determine the role of p38, ERK1/2, and JNK in Kupffer cell IL-6 and MCP-1 production. Briefly, the adherent cells were treated with selective inhibitors: a selective and cell-permeable inhibitor of MAPKK, which acts by inhibiting the activation of ERK1/2 and subsequent phosphorylation of MAPK (PD-98059; 20 µM; IC50 = 2 µM), a highly specific and cell-permeable inhibitor of p38 MAPK (SB-203580; 5 µM; IC50 = 600 nM), and a potent, cell-permeable, selective, and reversible inhibitor of c-Jun NH2-terminal kinase (JNK) (JNK inhibitor II/SP-600125; 20 µM; IC50 = 40 nM for JNK-1 and JNK-2 and 90 nM for JNK-3) (all from Calbiochem). Cells were then cultured for 24 h, the cell-free culture supernatants harvested and frozen at –80°C until further analysis. A minimum of two wells were set for each condition.
Statistical analysis.
Data are expressed as means ± SE and comparisons were analyzed using t-test for single comparisons or ANOVA for multiple comparisons. A P value 
0.05 was considered to be statistically significant for all analyses.
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RESULTS |
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10%) in hypoxia-mediated JNK phosphorylation in Kupffer cells, this decrease was not found to be significantly different from Kupffer cells of normoxic mice (Fig. 4C). These results indicate that the phosphorylation of p38 but not ERK or JNK MAPK is regulated through a Src-dependent pathway.
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Effects of MAPK on Kupffer cell cytokine production capacity. These experiments were performed to determine the role of p38, ERK1/2, and JNK in mediating the increased Kupffer cell IL-6 and MCP-1 production with the use of their respective inhibitors. The in vitro treatment of Kupffer cells from healthy animals with the specific p38 inhibitor SB-203580 resulted in a significant decrease in the production of IL-6 compared with untreated cells (Fig. 6A). However, ERK inhibitor PD-98059 or JNK inhibitor showed no effect on the constitutive Kupffer cell IL-6 production. In contrast, although there was a tendency of a decrease in Kupffer cell MCP-1 production following inhibition with both p38 and JNK (Fig. 6B), this decrease was not found to be significantly different from that observed in untreated cells. Furthermore, treatment of Kupffer cells with ERK1/2 inhibitor PD-98059 did not influence the MCP-1 production. These results collectively indicate that Src-mediated p38 upregulation plays a role in Kupffer cell IL-6 production after hypoxia.
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DISCUSSION |
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The Kupffer cells are considered to be a critical immune cell population that plays an important role in response to endotoxin (5), burns (15), sepsis (14), and hypoxia (17). Once activated, they serve as a major source of systemic levels of IL-6 (39) and MCP-1 (F. Hildebrand, W. J. Hubbard, M. A. Choudhry, H.-C. Pape, and I. H. Chaudry, unpublished observations). While IL-6 is well known to mediate further proinflammatory responses, MCP-1 plays an important role in the recruitment and activation of leukocytes as well as mediating Th2 responses (19). Studies (18) have shown that MCP-1 is integrated in a complex network of chemokines and the regulation of MIP-1
, MIP-1
, RANTES (regulated on activation of normal T cells), and MIP-2, thus regulating chemotaxis during inflammation in various tissues. Eukaryotic cells regulate various functions via the posttranslational mechanism of protein phosphorylation. This mechanism plays a critical role in regulating various cellular activities including gene expression, cell differentiation, and cell proliferation. However, it is important to note that protein phosphorylation is regulated by many factors, and activation at the single protein level is not necessarily controlled within a single pathway. Furthermore, cross-talk between different signaling cascades is often observed leading to a common effect in cellular response. Although MAPK have been implicated in various injury models of innate immune response, little information has been available about how other signaling cascades may influence their activation in response to a traumatic or hypoxic insult.
Mitogen-activated protein kinases are largely involved in eukaryotic cell signaling (7, 42). Three isoforms, p38, ERK1/2, and JNK, are shown to play a major role in the regulation of cellular responses following their activation with growth factors, osmotic shock, and UV light by inflammatory cytokines. Since 1994, when Han et al. (22) first described the activation of p38 MAPK by LPS in murine macrophages, the role of MAPK signaling pathways in the synthesis of inflammatory cytokines by macrophages has been studied in considerable detail. Previous studies (3, 35, 36) have shown that p38, ERK1/2 and JNK MAPK mediate the response of macrophages as well as T cells to traumatic injury. Furthermore, p38 activation is a critical aspect of Kupffer cell activation following burns, trauma (10), or LPS challenge. In addition, the production of TNF- by Kupffer cells in response to acute pancreatitis has been linked to increased activity of p38, ERK 1/2, and JNK MAPK (38). In the present study, we found that p38 plays a predominant role in Kupffer cell IL-6 production in response to hypoxia. In contrast, the production of MCP-1 was found to be independent of p38. Other studies (12) suggest that ERK1/2 is more critical in regulating Kupffer cell IL-6 production compared with p38. The difference between these studies is likely a result of different animal models and different stimuli used but may also reflect the differential regulatory pathways of Kupffer cells following various types of injury.
Src family tyrosine kinases have been implicated in many signaling pathways in immune cells such as growth, differentiation, and gene transcription (44). Their activity is regulated by tyrosine phosphorylation at two sites with opposing effects. While phosphorylation of Tyr527 renders the enzyme less active, Tyr416 phosphorylation upregulates enzyme activity (21). It is also known that hypoxia can activate c-Src leading to increased expression of vascular endothelial growth factor expression (37). Using anti phospho-Src (Tyr416), we examined Src family kinase activation in Kupffer cells from male mice following hypoxia. Our results showed that hypoxia resulted in increased Src activity. Treatment of the animals with Src inhibitor PP1 prevented the increase in Src phosphorylation as well as the subsequent increase in IL-6 production by Kupffer cells following hypoxia. Thus it is likely that Src tyrosine kinases play a role in mediating Kupffer cell response to hypoxia. We recognize that Src is one of several members of Src family tyrosine kinases and the antibodies to Src protein that we have used in this study may cross-react with other Src family members. Thus the possibility of an involvement of other Src family members in Kupffer cell IL-6 production has not been ruled out and this remains to be determined.
Protein phosphorylation within signaling cascades of innate immunity is known to be an early event in response to various stimuli. Src family members have been shown to be activated as rapidly as 1 min after stimulation and their phosphorylation peaks returned to baseline after 10 min (8). Furthermore, hypoxia leads to decreased organ blood flow and oxygen supply, thus interfering with the bioavailability of any administered pharmaceutical as well as its hepatic and renal clearance from the blood. In view of this, we used an in vivo pretreatment regimen with Src family kinase inhibitor PP1 to achieve sufficient inhibitor concentrations at the cellular level before the hypoxic insult to prevent any Src signaling.
Previous studies have linked MAPK as downstream targets to Src signaling (9). Moreover, Khadaroo et al. (30, 31) reported that the priming of macrophages in response to hemorrhagic shock is mediated through activation of p38 MAPK by an Src-dependent pathway. Consistent with these findings, our results suggest that Kupffer cell p38 activation following hypoxia is dependent on the activation of Src kinases. In contrast, other MAPKs, such as ERK1/2 and JNK were not affected by Src inhibition, indicating that ERK and JNK are not regulated by Src after hypoxia. Moreover, recent reports provide evidence that Src family kinases are likely to play a role in various signaling pathways of innate immunity. In light of this, Aki et al. (1) showed that TLR signaling in macrophages is modulated by COOH-terminal Src kinase, an enzyme regulating Src kinase activity.
To further elucidate the role of MAPK on Kupffer cell cytokine production, additional in vitro studies were performed. The results from these experiments confirmed that p38 is critical to Kupffer cell IL-6 production. In addition, we also examined the effect of ERK1/2 and JNK signaling on Kupffer cell IL-6 and MCP-1 production and found that ERK1/2 inhibitor PD-98059 or JNK inhibitor had no effect on IL-6 levels. This finding is in accordance with recent literature, reporting IL-6 regulation by p38 in various tissues (45). In contrast, MCP-1 production appeared to be independent from MAPK (p38, ERK, and JNK) signaling in the present study. Studies have also revealed controversial findings regarding the regulation of specific cytokines and chemokines by MAPK. Although p38 MAPK decreased MCP-1 levels in human colon epithelial cells (32), Kato et al. (27) have shown that MCP-1 production in murine peritoneal mesothelial cells does not require MAPK activation. The reason for the discrepancy between our findings and those of the above-mentioned studies is unclear.
Although we have not pinpointed the precise mechanism by which hypoxia produces an increase in Src kinase activity, the findings from previous studies suggest that several factors, including alterations in intracellular ATP levels and the release of lactic acid, may contribute to an increased proinflammatory cytokine production following hypoxia. These cytokines consecutively serve as a motor of inflammation under such conditions.
In summary, our study demonstrates that activation of Src kinases following hypoxia results in increased p38 activation and thus leads to an increase in IL-6 production in Kupffer cells from male mice. Although hypoxia also increased MCP-1 production by Kupffer cells, we found that these differences in MCP-1 are independent of Src. Nonetheless, further studies are required to delineate the mechanism of increased MCP-1 following hypoxia. Further studies are also needed to delineate whether Src influences pre- or posttranslational events in the regulation of Kupffer cell IL-6 production. We believe that insight into these signaling pathways after hypoxia is critical for developing pharmacological interventions, as well as for the potential to understand differences in host responses.
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FOOTNOTES |
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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.
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REFERENCES |
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2. Akiyama C, Yuguchi T, Nishio M, Tomishima T, Fujinaka T, Taniguchi M, Nakajima Y, Kohmura E, and Yoshimine T. Src family kinase inhibitor PP1 reduces secondary damage after spinal cord compression in rats. J Neurotrauma 21: 923–931, 2004.[CrossRef][Web of Science][Medline]
3. Alexander M, Daniel T, Chaudry IH, and Schwacha MG. MAP kinases differentially regulate the expression of macrophage hyperactivity after thermal injury. J Cell Physiol 201: 35–44, 2004.[CrossRef][Web of Science][Medline]
4. Baue AE, Durham R, and Faist E. Systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), multiple organ failure (MOF): are we winning the battle? Shock 10: 79–89, 1998.[Web of Science][Medline]
5. Bautista AP, Meszaros K, Bojta J, and Spitzer JJ. Superoxide anion generation in the liver during the early stage of endotoxemia in rats. J Leukoc Biol 48: 123–128, 1990.[Abstract]
6. Bjorge JD, Jakymiw A, and Fujita DJ. Selected glimpses into the activation and function of Src kinase. Oncogene 19: 5620–5635, 2000.[CrossRef][Web of Science][Medline]
7. Blumer KJ and Johnson GL. Diversity in function and regulation of MAP kinase pathways. Trends Biochem Sci 19: 236–240, 1994.[CrossRef][Web of Science][Medline]
8. Boney CM, Sekimoto H, Gruppuso PA, and Frackelton AR Jr. Src family tyrosine kinases participate in insulin-like growth factor I mitogenic signaling in 3T3–L1 cells. Cell Growth Differ 12: 379–386, 2001.
9. Callera GE, Touyz RM, Tostes RC, Yogi A, He Y, Malkinson S, and Schiffrin EL. Aldosterone activates vascular p38MAP kinase and NADPH oxidase via c-Src. Hypertension 45: 773–779, 2005.
10. Chen XL, Xia ZF, Wei D, Han S, Ben DF, and Wang GQ. Role of p38 mitogen-activated protein kinase in Kupffer cell secretion of the proinflammatory cytokines after burn trauma. Burns 29: 533–539, 2003.[CrossRef][Web of Science][Medline]
11. Cohen J. The immunopathogenesis of sepsis. Nature 420: 885–891, 2002.[CrossRef][Medline]
12. Dahle MK, Overland G, Myhre AE, Stuestol JF, Hartung T, Krohn CD, Mathiesen O, Wang JE, and Aasen AO. The phosphatidylinositol 3-kinase/protein kinase B signaling pathway is activated by lipoteichoic acid and plays a role in Kupffer cell production of interleukin-6 (IL-6) and IL-10. Infect Immun 72: 5704–5711, 2004.
13. Deo DD, Axelrad TW, Robert EG, Marcheselli V, Bazan NG, and Hunt JD. Phosphorylation of STAT-3 in response to basic fibroblast growth factor occurs through a mechanism involving platelet-activating factor, JAK-2, and Src in human umbilical vein endothelial cells. Evidence for a dual kinase mechanism. J Biol Chem 277: 21237–21245, 2002.
14. Doi F, Goya T, and Torisu M. Potential role of hepatic macrophages in neutrophil-mediated liver injury in rats with sepsis. Hepatology 17: 1086–1094, 1993.[CrossRef][Web of Science][Medline]
15. Dong YL, Herndon DN, Yan TZ, and Waymack JP. Blockade of prostaglandin products augments macrophage and neutrophil tumor necrosis factor synthesis in burn injury. J Surg Res 54: 480–485, 1993.[CrossRef][Web of Science][Medline]
16. Ertel W, Friedl HP, and Trentz O. Multiple organ dysfunction syndrome (MODS) following multiple trauma: rationale and concept of therapeutic approach. Eur J Pediatr Surg 4: 243–248, 1994.[Web of Science][Medline]
17. Ertel W, Morrison MH, Ayala A, and Chaudry IH. Hypoxemia in the absence of blood loss or significant hypotension causes inflammatory cytokine release. Am J Physiol Regul Integr Comp Physiol 269: R160–R166, 1995.
18. Ferreira AM, Rollins BJ, Faunce DE, Burns AL, Zhu X, and Dipietro LA. The effect of MCP-1 depletion on chemokine and chemokine-related gene expression: evidence for a complex network in acute inflammation. Cytokine 30: 64–71, 2005.[CrossRef][Web of Science][Medline]
19. Furukawa K, Kobayashi M, Herndon DN, Pollard RB, and Suzuki F. Appearance of monocyte chemoattractant protein 1 (MCP-1) early after thermal injury: role in the subsequent development of burn-associated type 2 T-cell responses. Ann Surg 236: 112–119, 2002.[CrossRef][Web of Science][Medline]
20. Goel R, Phillips-Mason PJ, Raben DM, and Baldassare JJ. -Thrombin induces rapid and sustained Akt phosphorylation by -arrestin1-dependent and -independent mechanisms, and only the sustained Akt phosphorylation is essential for G1 phase progression. J Biol Chem 277: 18640–18648, 2002.
21. Gonfloni S, Weijland A, Kretzschmar J, and Superti-Furga G. Crosstalk between the catalytic and regulatory domains allows bidirectional regulation of Src. Nat Struct Biol 7: 281–286, 2000.[CrossRef][Web of Science][Medline]
22. Han J, Lee JD, Bibbs L, and Ulevitch RJ. A MAP kinase targeted by endotoxin and hyperosmolarity in mammalian cells. Science 265: 808–811, 1994.
23. Hanke JH, Gardner JP, Dow RL, Changelian PS, Brissette WH, Weringer EJ, Pollok BA, and Connelly PA. Discovery of a novel, potent, and Src family-selective tyrosine kinase inhibitor. Study of Lck- and FynT-dependent T cell activation. J Biol Chem 271: 695–701, 1996.
24. Hoyert DL, Kung HC, and Smith BL. Deaths: preliminary data for 2003. In: National Vital Statistics Reports. Hyattsville, MD: National Center for Health Statistics, vol. 53, no. 15, 2005. [The data are available at http://www.cdc.gov/nchs/data/nvsr/nvsr54/nvsr54_13.pdf]
25. Hsu CM, Wang JS, Liu CH, and Chen LW. Kupffer cells protect liver from ischemia-reperfusion injury by an inducible nitric oxide synthase-dependent mechanism. Shock 17: 280–285, 2002.[CrossRef][Web of Science][Medline]
26. Kang JL, Lee HW, Kim HJ, Lee HS, Castranova V, Lim CM, and Koh Y. Inhibition of SRC tyrosine kinases suppresses activation of nuclear factor-
B, and serine and tyrosine phosphorylation of IB- in lipopolysaccharide-stimulated RAW 264.7 macrophages. J Toxicol Environ Health 68: 1643–1662, 2005.[CrossRef][Web of Science]
27. Kato S, Yuzawa Y, Tsuboi N, Maruyama S, Morita Y, Matsuguchi T, and Matsuo S. Endotoxin-induced chemokine expression in murine peritoneal mesothelial cells: the role of toll-like receptor 4. J Am Soc Nephrol 15: 1289–1299, 2004.
28. Keel M and Trentz O. Pathophysiology of polytrauma. Injury 36: 691–709, 2005.[CrossRef][Web of Science][Medline]
29. Keller SA, Paxian M, Ashburn JH, Clemens MG, and Huynh T. Kupffer cell ablation improves hepatic microcirculation after trauma and sepsis. J Trauma 58: 740–749, 2005.[Web of Science][Medline]
30. Khadaroo RG, He R, Parodo J, Powers KA, Marshall JC, Kapus A, and Rotstein OD. The role of the Src family of tyrosine kinases after oxidant-induced lung injury in vivo. Surgery 136: 483–488, 2004.[CrossRef][Web of Science][Medline]
31. Khadaroo RG, Parodo J, Powers KA, Papia G, Marshall JC, Kapus A, and Rotstein OD. Oxidant-induced priming of the macrophage involves activation of p38 mitogen-activated protein kinase through an Src-dependent pathway. Surgery 134: 242–246, 2003.[CrossRef][Web of Science][Medline]
32. Kim JM, Jung HY, Lee JY, Youn J, Lee CH, and Kim KH. Mitogen-activated protein kinase and activator protein-1 dependent signals are essential for Bacteroides fragilis enterotoxin-induced enteritis. Eur J Immunol 35: 2648–2657, 2005.[CrossRef][Web of Science][Medline]
33. Knoferl MW, Jarrar D, Schwacha MG, Angele MK, Cioffi WG, Bland KI, and Chaudry IH. Severe hypoxemia in the absence of blood loss causes a gender dimorphic immune response. Am J Physiol Cell Physiol 279: C2004–C2010, 2000.
34. Laemmli UK. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227: 680–685, 1970.[CrossRef][Medline]
35. Maung AA, Fujimi S, Miller ML, MacConmara MP, Mannick JA, and Lederer JA. Enhanced TLR4 reactivity following injury is mediated by increased p38 activation. J Leukoc Biol 78: 565–573, 2005.
36. McCloskey CA, Kameneva MV, Uryash A, Gallo DJ, and Billiar TR. Tissue hypoxia activates JNK in the liver during hemorrhagic shock. Shock 22: 380–386, 2004.[CrossRef][Web of Science][Medline]
37. Mukhopadhyay D, Tsiokas L, Zhou XM, Foster D, Brugge JS, and Sukhatme VP. Hypoxic induction of human vascular endothelial growth factor expression through c-Src activation. Nature 375: 577–581, 1995.[CrossRef][Medline]
38. Murr MM, Yang J, Fier A, Gallagher SF, Carter G, Gower WR Jr, and Norman JG. Regulation of Kupffer cell TNF gene expression during experimental acute pancreatitis: the role of p38-MAPK, ERK1/2, SAPK/JNK, and NF-B. J Gastrointest Surg 7: 20–25, 2003.[CrossRef][Web of Science][Medline]
39. O’Neill PJ, Ayala A, Wang P, Ba ZF, Morrison MH, Schultze AE, Reich SS, and Chaudry IH. Role of Kupffer cells in interleukin-6 release following trauma-hemorrhage and resuscitation. Shock 1: 43–47, 1994.[Web of Science][Medline]
40. Rana MW, Ayala A, Dean RE, and Chaudry IH. Decreased Fc receptor expression on macrophages following simple hemorrhage as observed by scanning immunoelectron microscopy. J Leukoc Biol 48: 512–518, 1990.[Abstract]
41. Rotstein OD. Modeling the two-hit hypothesis for evaluating strategies to prevent organ injury after shock/resuscitation. J Trauma 54: S203–S206, 2003.[Web of Science][Medline]
42. Seger R and Krebs EG. The MAPK signaling cascade. FASEB J 9: 726–735, 1995.[Abstract]
43. Suzaki Y, Yoshizumi M, Kagami S, Koyama AH, Taketani Y, Houchi H, Tsuchiya K, Takeda E, and Tamaki T. Hydrogen peroxide stimulates c-Src-mediated big mitogen-activated protein kinase 1 (BMK1) and the MEF2C signaling pathway in PC12 cells: potential role in cell survival following oxidative insults. J Biol Chem 277: 9614–9621, 2002.
44. Thomas SM and Brugge JS. Cellular functions regulated by Src family kinases. Annu Rev Cell Dev Biol 13: 513–609, 1997.[CrossRef][Web of Science][Medline]
45. Wang M, Sankula R, Tsai BM, Meldrum KK, Turrentine M, March KL, Brown JW, Dinarello CA, and Meldrum DR. P38 MAPK mediates myocardial proinflammatory cytokine production and endotoxin-induced contractile suppression. Shock 21: 170–174, 2004.[CrossRef][Web of Science][Medline]
46. Wisse E. Kupffer cell reactions in rat liver under various conditions as observed in the electron microscope. J Ultrastruct Res 46: 499–520, 1974.[CrossRef][Web of Science][Medline]
47. Wu W, Graves LM, Gill GN, Parsons SJ, and Samet JM. Src-dependent phosphorylation of the epidermal growth factor receptor on tyrosine 845 is required for zinc-induced Ras activation. J Biol Chem 277: 24252–24257, 2002.
48. Zellweger R, Ayala A, DeMaso CM, and Chaudry IH. Trauma-hemorrhage causes prolonged depression in cellular immunity. Shock 4: 149–153, 1995.[Web of Science][Medline]
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 T. Kawasaki, M. A. Choudhry, M. G. Schwacha, S. Fujimi, J. A. Lederer, K. I. Bland, and I. H. Chaudry Trauma-hemorrhage inhibits splenic dendritic cell proinflammatory cytokine production via a mitogen-activated protein kinase process Am J Physiol Cell Physiol, March 1, 2008; 294(3): C754 - C764. [Abstract] [Full Text] [PDF]
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J. Fujita-Yoshigaki, M. Matsuki-Fukushima, and H. Sugiya Inhibition of Src and p38 MAP kinases suppresses the change of claudin expression induced on dedifferentiation of primary cultured parotid acinar cells Am J Physiol Cell Physiol, March 1, 2008; 294(3): C774 - C785. [Abstract] [Full Text] [PDF]
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 R. J. Anand, S. C. Gribar, J. Li, J. W. Kohler, M. F. Branca, T. Dubowski, C. P. Sodhi, and D. J. Hackam Hypoxia causes an increase in phagocytosis by macrophages in a HIF-1{alpha}-dependent manner J. Leukoc. Biol., November 1, 2007; 82(5): 1257 - 1265. [Abstract] [Full Text] [PDF]
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O. Norkina, A. Dolganiuc, T. Shapiro, K. Kodys, P. Mandrekar, and G. Szabo Acute alcohol activates STAT3, AP-1, and Sp-1 transcription factors via the family of Src kinases to promote IL-10 production in human monocytes J. Leukoc. Biol., September 1, 2007; 82(3): 752 - 762. [Abstract] [Full Text] [PDF]
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 T. A. Markel, P. R. Crisostomo, M. Wang, C. M. Herring, T. Lahm, K. K. Meldrum, K. D. Lillemoe, F. J. Rescorla, and D. R. Meldrum Iron chelation acutely stimulates fetal human intestinal cell production of IL-6 and VEGF while decreasing HGF: the roles of p38, ERK, and JNK MAPK signaling Am J Physiol Gastrointest Liver Physiol, April 1, 2007; 292(4): G958 - G963. [Abstract] [Full Text] [PDF]
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 M. Wang, T. Markel, P. Crisostomo, C. Herring, K. K. Meldrum, K. D. Lillemoe, and D. R. Meldrum Deficiency of TNFR1 protects myocardium through SOCS3 and IL-6 but not p38 MAPK or IL-1beta Am J Physiol Heart Circ Physiol, April 1, 2007; 292(4): H1694 - H1699. [Abstract] [Full Text] [PDF]
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 M. Frink, B. M. Thobe, Y.-C. Hsieh, M. A. Choudhry, M. G. Schwacha, K. I. Bland, and I. H. Chaudry 17beta-Estradiol inhibits keratinocyte-derived chemokine production following trauma-hemorrhage Am J Physiol Lung Cell Mol Physiol, February 1, 2007; 292(2): L585 - L591. [Abstract] [Full Text] [PDF]
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