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J. Biol. Chem., Vol. 281, Issue 46, 34730-34735, November 17, 2006

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Elafin Prevents Lipopolysaccharide-induced AP-1 and NF-B Activation via an Effect on the Ubiquitin-Proteasome Pathway^*

From the Pulmonary Research Division, Department of Medicine, The Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin 9, Ireland

Received for publication, May 19, 2006 , and in revised form, September 14, 2006.

	ABSTRACT

TOP ABSTRACT INTRODUCTION EXPERIMENTAL PROCEDURES RESULTS DISCUSSION REFERENCES

 
The serine anti-protease elafin is expressed by monocytes, alveolar macrophages, neutrophils, and at mucosal surfaces and possesses antimicrobial activity. It is also known to reduce lipopolysaccharide-induced neutrophil influx into murine alveoli as well as to abrogate lipopolysaccharide-induced production of matrix metalloprotease 9, macrophage inhibitory protein 2, and tumor necrosis factor- by as-yet unidentified mechanisms. In this report we have shown that elafin inhibits the lipopolysaccharide-induced production of monocyte chemoattractant protein-1 in monocytes by inhibiting AP-1 and NF-B activation. Elafin prevented lipopolysaccharide-induced phosphorylation of AP-1, c-Jun, and JNK but had no effect on phosphorylation of p38. The lipopolysaccharide-induced degradation of IL-1R-associated kinase 1, IB, and IB was inhibited by elafin but phosphorylation of IB was unaffected. Polyubiquitinated protein including polyubiquitinated IB was shown to accumulate in the presence of elafin. These results suggest that inhibition by elafin of lipopolysaccharide-induced AP-1 and NF-B activation occurs via an effect on the ubiquitin-proteasome pathway.

	INTRODUCTION

TOP ABSTRACT INTRODUCTION EXPERIMENTAL PROCEDURES RESULTS DISCUSSION REFERENCES

 
Elafin is a 6-kDa serine anti-protease initially identified in psoriatic skin scales and is also called skin-derived anti-leucoprotease. Subsequently, "elastase-specific inhibitor" was isolated from human sputum and found to have identical N-terminal sequencing as skin-derived anti-leucoprotease, and the term elafin was suggested (1). Elafin is currently known to be expressed in airways, other mucosal surfaces such as esophagus, vagina, endometrium, and coronary intima and by inflammatory cells such as monocytes, alveolar macrophages, and neutrophils.

Structurally, elafin is a member of the WAP (whey acidic protein) family of proteins characterized by possessing a C-terminal core domain consisting of four disulfide bonds. Also known as trappins (transglutaminase substrate and wap domain-containing protein), these proteins also possess an N-terminal domain consisting of a variable number of repeats with the consensus sequence Gly-Gln-Asp-Pro-Val-Lys that can act as an anchoring motif by transglutaminase cross-linking (2). Pre-elafin, also known as trappin 2, is thought to undergo proteolytic cleavage, possibly by tryptase, releasing the elafin molecule (3). Elafin is a cationic protease inhibitor of human neutrophil elastase, proteinase 3, and porcine pancreatic elastase and is induced by cytokine and other stimuli including interleukin 1, tumor necrosis factor, human elasneutrophil tase, and lipopolysaccharide (LPS)² (1). The gene governing elafin (and other WAP proteins) expression was cloned and sequenced on the long arm of chromosome 20. Transcriptional activation of elafin appears to be cell specific; in pulmonary epithelial cells elafin is regulated at a transcriptional level by the transcription factor nuclear factor B (NF-B) (4), whereas in mammary epithelial cells the transcription factor activating protein-1 (AP-1) mediates transcriptional activation (5). The observation that elafin is highly cationic and shows selective expression at mucosal, epithelial, and endothelial surfaces suggested that it possesses antimicrobial properties. Indeed, elafin has been shown to have antimicrobial activity that is independent of its anti-elastase activity or charge properties (6). In mice, pre-elafin has been shown to dose dependently reduce LPS-induced neutrophil influx into alveoli, in addition to inhibiting LPS-induced production of the potent neutrophil attractants MMP-9 (gelatinase) and MIP-2 (macrophage inflammatory protein-2), suggesting an immunomodulatory role in innate immunity (7). We have previously shown that secretory leucoprotease inhibitor (SLPI), another WAP protein closely related to elafin, prevents lipopolysaccharide-induced IB degradation without affecting phosphorylation or ubiquitination in monocytic cells (8) and, furthermore, that SLPI can impair lipoteichoic acid-induced proinflammatory gene expression in monocytes and macrophages in vitro, processes diminished by oxidation and elastase complex formation of SLPI (9).

In light of these results, we have looked at the modulatory effects of elafin on LPS signaling in U937 cells, including the effect of elafin on LPS-induced monocyte chemotactic protein-1 (MCP-1). MCP-1 is a chemokine produced by mononuclear phagocytes and is a potent activator of monocyte function (10, 11). MCP-1 has a crucial role in monocyte recruitment in vivo in several organs and tissues (12–14), and its role in monocyte infiltration in several inflammatory diseases has been described (10, 11). MCP-1 gene expression is cell type and stimulus specific, and its transcription is regulated by transcription factors including AP-1 and NF-B (15–18). In addition, LPS-induced MCP-1 expression has been shown to be dependent on c-Jun NH₂-terminal kinase (JNK) activation (19). In this report we show that elafin inhibits the LPS-induced production of MCP-1 in U937 cells via inhibition of AP-1 and NF-B and that this occurs through the effect of elafin upon the ubiquitin-proteasome pathway.

	EXPERIMENTAL PROCEDURES

TOP ABSTRACT INTRODUCTION EXPERIMENTAL PROCEDURES RESULTS DISCUSSION REFERENCES

 
Materials—RPMI 1640 medium was obtained from Invitrogen, and U937 cells were purchased from the American Type Culture Collection (Manassas, VA). Recombinant human elafin was obtained from Proteo Biotech AG (Kiel, Germany). Antibodies to phosphorylated and total ATF2, c-Jun, JNK, and IB and to IRAK, IB, and phosphorylated p38 were obtained from Cell Signaling Technology (Beverly, MA). Antibody to p38 and lamin B1 was purchased from Santa Cruz Biotechnology (Santa Cruz, CA). IRAK-1 antibody was obtained from BD Biosciences. Antibody to ubiquitin was purchased from Sigma. Western blotting reagents were obtained from Pierce. Fluorogenic substrates for 20 S proteasome activity assays were purchased from Merck Biosciences.

Cell Culture—Human myelomonocytic U937 cells were cultured in RPMI 1640 containing 10% fetal calf serum, 2 mM glutamine, penicillin, and streptomycin and were maintained at 37 °C in a humidified atmosphere of 5% CO₂.

Preparation of Cytoplasmic and Nuclear Extracts—After treating cells with elafin and/or LPS for the indicated times in 24-well plates (1 x 10⁶ cells/ml), the cells were washed in ice-cold phosphate-buffered saline and resuspended in a hypotonic buffer (10 mM HEPES, pH 7.9, 1.5 mM MgCl₂, 10 mM KCl, and 0.5 mM dithiothreitol). Cells were pelleted by centrifugation at 14,000 x g for 10 min at 4 °C and then lysed for 10 min on ice in 20 µl of hypotonic buffer containing 0.1% Igepal CA-630, 1 mM sodium vanadate, 50 mM -glycerophosphate, and 1x complete protease inhibitor mixture (Roche Applied Science). Lysates were centrifuged as before, and the supernatant (cytoplasmic fraction) was retained for Western analysis (see below). The remaining nuclear pellet was lysed in 15 µl of lysis buffer (20 mM HEPES, pH 7.9, 420 mM NaCl, 1.5 mM MgCl₂, 0.2 mM EDTA, 25% (v/v) glycerol, 0.5 mM phenylmethylsulfonyl fluoride, 1 mM sodium vanadate, 50 mM -glycerophosphate, and 1x complete protease inhibitor mixture) for 15 min on ice. After centrifugation at 14,000 x g for 15 min at 4 °C, nuclear extracts were removed, and the extracts were stored at –80 °C.

EMSA—Nuclear extracts (5 µg) were incubated with biotin end-labeled double-stranded oligonucleotide containing the AP-1 or NF-B consensus sequences (MWG Biotech). Incubations were performed for 30 min at room temperature in binding buffer (4% (v/v) glycerol, 1 mM EDTA, 10 mM Tris-HCl, pH 7.5, 100 mM NaCl, 5 mM dithiothreitol, 0.1 mg/ml nuclease-free bovine serum albumin) and 2 µg of poly(dI·dC) (Sigma). Reaction mixtures were electrophoresed on native 6% polyacrylamide gels and blotted. Transferred nuclear proteins were cross-linked by UV transillumination, blocked, incubated with streptavidin peroxidase, and finally developed by chemiluminescent methodology (Pierce).

View larger version (17K): [in this window] [in a new window]   FIGURE 1. Elafin inhibits LPS-induced MCP-1 production. U937s were cultured (1 x 106/ml) in medium alone, with LPS (0.1 µg/ml), or preincubated with elafin (10 µg/ml) for 1 h at 37 °C for 24 h. Enzyme-linked immunosorbent assay represents results from three experiments.

20 S Proteasome Activity Assays—Three different peptidase activities associated with the 20 S proteasome were measured using the fluorogenic substrates Suc-Leu-Leu-Val-Tyr-AMC (for chymotrypsin-like activity), Z-Leu-Leu-Glu-AMC (for peptidylglutamyl peptide hydrolyzing activity), and Z-Ala-Arg-Arg-AMC (for trypsin-like activity). Treated cells were lysed in 700 µl of 25 mM HEPES, 5 mM EDTA, 0.1% CHAPS, 5 mM ATP, pH 7.5, with 2 mM dithiothreitol (21). Each sample was incubated with each substrate (50 µM, final concentration) in lysis buffer for 30 min at 37 °C, and fluorescence (substrate turnover) was determined by excitation at 355 nm and emission at 460 nm.

View larger version (27K): [in this window] [in a new window]   FIGURE 2. Elafin down-regulation of LPS-induced AP-1 (A) and NF-B(B) activation. Nuclear extracts were prepared from U937s cultured in medium alone, with LPS (2 µg/ml), or preincubated with elafin (10 µg/ml) followed by activation with LPS (2 µg/ml) over a time course shown in minutes. Reaction mixtures containing 5 µg of protein and 0.5 µl of biotin end-labeled oligonucleotide containing either the AP-1 or NK-B consensus sequences were resolved by electrophoresis on a 6% polyacrylamide gel. Each electrophoretic mobility shift assay represents results from three experiments. Con, control. C and D, elafin prevents LPS-induced phosphorylation of ATF2 and c-Jun. Nuclear lysates from U9373s cultured (2 x 106/ml) in medium alone, with LPS (2 µg/ml), or preincubated with elafin (10 µg/ml) followed by LPS (2 µg/ml) over the time courses shown in minutes were electrophoresed on a 10% SDS-PAGE and probed by Western blot for phosphorylated and total ATF2 antibody (C) and phosphorylated and total c-Jun (D). Results shown are representative of three separate experiments. Con, control. Phospho, phosphorylated.

	RESULTS

TOP ABSTRACT INTRODUCTION EXPERIMENTAL PROCEDURES RESULTS DISCUSSION REFERENCES

Because MCP-1 expression is regulated by the transcription factors AP-1 and NF-B, the effect of elafin on LPS-induced transcription factor activation was examined by preincubating U937 cells with elafin (1 h) followed by LPS over the time courses shown (Fig. 2, A and B). LPS was shown to induce significantly more AP-1 activation in U937 cells (Fig. 2A, left, lanes 30, 60, and 120) compared with cells incubated in medium alone (Fig. 2A, left, lane Con). Elafin prevented LPS-induced AP-1 activation across the time course (Fig. 2A, right). Similarly, LPS induced significantly more NF-B activation (Fig. 2B, left, lanes 15, 30, and 60) versus control (Fig. 2B, lane Con), which was markedly inhibited by elafin (Fig. 2B, right).

To investigate the effect of elafin on LPS-induced phosphorylation of AP-1 subunits, phosphorylation of activating transcription factor 2 (ATF2) and c-Jun was assessed. LPS was shown to induce phosphorylation of ATF2 (Fig. 2C, top panel, left), and this phosphorylation was significantly abrogated by preincubation with elafin (Fig. 2C, upper panel, right). Protein loading was controlled for by probing the stripped blot for total ATF2 (Fig. 2C, lower panel). Similarly, LPS-induced phosphorylation of c-Jun was prevented by preincubation with elafin (Fig. 2D, upper panel). Again, protein loading was controlled for by stripping the blot and reprobing for total c-Jun (Fig. 2D, lower panel).

View larger version (36K): [in this window] [in a new window]   FIGURE 3. Elafin has no effect on p38 phosphorylation but inhibits JNK phosphorylation. U937s were cultured (1 x 106/ml) in medium alone, with LPS (2 µg/ml), or preincubated with elafin (10 µg/ml) followed by LPS (2 µg/ml) over the time courses indicated. Cytoplasmic (A) and nuclear (B) fractions were subjected to Western analysis for phosphorylated and total p38. Cytoplasmic fractions were also analyzed for phosphorylated and total JNK (C), and nuclear fractions were analyzed for phosphorylated JNK and lamin B1 (D), the latter as a loading control. Results shown are representative of three separate experiments. Con, control. Phospho, phosphorylated.

View larger version (49K): [in this window] [in a new window]   FIGURE 4. Elafin prevents LPS-induced degradation of IB, IB, and IRAK. A, U937s were cultured (2 x 106/ml) in medium alone, with LPS (2 µg/ml), or preincubated with elafin (10 µg/ml) followed by activation with LPS (2 µg/ml) over the time courses shown in minutes. Cytoplasmic fractions were subjected to Western analysis for IB (A), IB (B), and IRAK (C). Results shown represent results of three experiments. Con, control.

View larger version (41K): [in this window] [in a new window]   FIGURE 5. Elafin has no effect on LPS-induced phosphorylation of IB or on specified 20 S peptidase activities but results in increased polyubiquitination. A, U937s were cultured (2 x 106/ml) in medium alone or with the proteasome inhibitor ALLN (1 µl/ml) either alone, with LPS (2 µg/ml), or preincubated with elafin (10 µg/ml, 1 h) followed by LPS (2 µg/ml, 30 min). Cytoplasmic lysates of duplicate samples were electrophoresed on a 10% SDS-PAGE and probed by Western blot for phosphorylated IB. Lanes 1 and 2, control lysates; lanes 3 and 4, control + ALLN lysates; lanes 5 and 6, LPS + ALLN lysates; lanes 7 and 8, Elafin/LPS + ALLN lysates. B, cytoplasmic extracts from cells treated in medium alone, with LPS, or preincubated with elafin were assayed for 20 S peptidase activity, i.e. for chymotrypsin-like activity using Suc-LLVY-AMC, peptidylglutamyl peptidehydrolyzing activity using Z-LLE-AMC, and for trypsin-like activity using Z-ARR-AMC. Extracts were incubated in buffer (25 mM HEPES, 5 mM EDTA, 0.1% CHAPS, 5 mM ATP, pH 7.5 with 2 mM dithiothreitol) for 30 min at 37 °C, and fluorescence was determined by excitation at 355 nm and emission at 460 nm. C, cells were also cultured (2 x 106/ml) in medium alone, with LPS (2 µg/ml), elafin alone, or preincubated with elafin followed by activation with LPS (2µg/ml) for 4 h, and cytoplasmic fractions were subjected to Western analysis for ubiquitin and IB. Results shown are representative of three separate experiments. Con, control. Phospho, phosphorylated, FU, fluorescence unit.

To investigate whether elafin affects the phosphorylation of IB, cells were treated with or without the proteasome inhibitor ALLN (100 µg/ml for 30 min), used to stabilize the labile phosphorylated IB. The U937s were incubated in medium alone, medium with ALLN, stimulated with LPS in the presence of ALLN, or preincubated with ALLN and then elafin followed by stimulation with LPS. Phosphorylation of IB was observed in all samples treated with ALLN (Fig. 5A, lanes 3–8), although only weakly so in the samples not also treated with LPS (Fig. 5A, lanes 3–4). The increased phosphorylation of IB seen in the samples pretreated with elafin (Fig. 5A, lanes 7–8) was similar to that observed in the samples treated with ALLN and LPS alone (Fig. 5A, lanes 5–6).

Because the NF-B regulatory proteins IRAK, IB, and IB undergo ubiquitination in response to stimuli such as LPS and because elafin did not appear to prevent the LPS-induced phosphorylation of IB, we assessed the possible effect of elafin on proteasome function. First, the effect of elafin on peptidase activity associated with the 20 S proteasome was determined. Elafin was found not to affect any of the peptidase activities assessed (Fig. 5B). However, LPS-induced polyubiquitination appeared to increase in the presence of elafin/LPS compared with when stimulated with LPS or elafin alone (Fig. 5C) as assessed by Western blot analysis, indicating an effect of elafin on turnover of polyubiquitinated proteins. Finally, polyubiquitinated IB was also found to accumulate in the presence of elafin/LPS compared with LPS and elafin alone, indicating a specific effect of elafin on the turnover of IB following LPS stimulation (Fig. 5C).

	DISCUSSION

TOP ABSTRACT INTRODUCTION EXPERIMENTAL PROCEDURES RESULTS DISCUSSION REFERENCES

 
Elafin inhibits LPS-induced production of MCP-1 in the U937 monocytic cell line by preventing the LPS-induced activation of AP-1 and NF-B. This anti-inflammatory effect appears to be dependent upon an effect of elafin on the ubiquitin-proteasome pathway.

LPS activates the transcription factors AP-1 and NF-B via a process that initially involves binding of LPS to the cell membrane proteins, TLR4 and MD-2, which is facilitated by CD14 (22). Signal can then be transduced via a MyD88-dependent pathway involving IRAK and tumor necrosis factor receptor-associated factor (TRAF)-6 resulting in activation of the mitogen-activated protein kinase, TAK1 (23, 24). From this point, TAK-1 acts as a common activator of NF-B and AP-1 pathways. The subsequent phosphorylation of a group of inhibitory-binding proteins B(IB) allows them to be ubiquitinated and degraded, which allows NF-B to translocate into the nucleus (25). In the AP-1 pathway, JNK phosphorylation leads to activation of a number of proteins including ATF-2 and c-Jun, subunits of AP-1 (26).

In our study, elafin prevented the LPS-induced phosphorylation of JNK and the subsequent phosphorylation of the AP-1 subunits ATF2 and c-Jun. Although the kinase p38 is also responsible for the phosphorylation and activation of AFT2, elafin had no effect on the LPS-induced phosphorylation of p38. In addition, elafin prevented the LPS-induced degradation of the NF-B regulatory proteins IRAK, IB, and IB. These proteins are regulated by phosphorylation, ubiquitination, and proteasomal degradation (25). Although elafin appeared to have no effect on LPS-induced phosphorylation of IB, we found that elafin appears to delay ubiquitination of proteins in response to LPS, which corresponded to the inhibition of LPS-induced IRAK, IB, and IB degradation in the presence of elafin. Upon activation by LPS, IRAK associates with TRAF6, and the latter is required for activation of germinal center kinase, by transiently stabilizing the ubiquitinated germinal center kinase polypeptide. Germinal center kinase then participates in the optimal activation of JNK (27). It may be that elafin somehow perturbs the TRAF6-dependent stabilization of germinal center kinase by interfering with the ubiquitin-proteasome machinery that normally regulates germinal center kinase. This would account for our observed inhibitory effect of elafin on JNK as opposed to p38 phosphorylation.

Taken together, these observations suggest that inhibition by elafin of LPS-induced AP-1 and NF-B activity is due to an inhibitory effect of elafin on the ubiquitin-proteasome pathway. We have previously shown similar effects of SLPI on LPS and lipoteichoic acid-induced IRAK, IB, and IB degradation (8, 9). We have recently demonstrated that SLPI can enter monocytes, thus suggesting a direct effect of SLPI on the ubiquitin-proteasome pathway (28). Another antimicrobial peptide, PR-39, has been shown to inhibit TNF-induced NF-B activation by affecting proteasome function (29). Therefore, it seems likely that the anti-inflammatory activity of SLPI and elafin is due, in part, to their ability to enter cells and act at some point on the ubiquitin-proteasome pathway, resulting in delayed turnover of polyubiquitinated proteins with repercussions for activation of the NF-B and AP-1 pathways. However, peptidase activities associated with the 20 S proteasome were not affected by elafin.

In conclusion, the evidence presented in this study shows that elafin inhibits LPS-induced AP-1 and NF-B activation through an effect on the ubiquitin-proteasome pathway. Due to its selective expression at mucosal surfaces, as well as in alveolar macrophages, monocytes, and neutrophils, the ability of elafin to inhibit LPS signaling may be important in disease states such as cystic fibrosis, pneumonia, and acute respiratory distress syndrome. The inhibition of two key inflammatory pathways confirms the importance of elafin as a mediator of the innate immune response.

	FOOTNOTES

 
^* This work was funded by the American Alpha One Foundation (RO3-18) (to C. T.), Health Research Board of Ireland, and the Research Committee of The Royal College of Surgeons in Ireland. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

¹ To whom correspondence should be addressed: Pulmonary Research Division, Dept. of Medicine, The Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin 9, Ireland. Tel.: 353-1-8093712; Fax: 353-1-8093808; E-mail: ctaggart{at}rcsi.ie.

² The abbreviations used are: LPS, lipopolysaccharide; MCP-1, monocyte chemoattractant protein-1; SLPI, secretory leucoprotease inhibitor; ALLN, N-acetyl-Leu-Leu-norleucinal; AMC, 7-amino-4-methylcoumarin; CHAPS, 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonic acid; IRAK, IL-1R-associated kinase; JNK, c-Jun N-terminal kinase; Z, benzyloxycarbonyl.

	REFERENCES

TOP ABSTRACT INTRODUCTION EXPERIMENTAL PROCEDURES RESULTS DISCUSSION REFERENCES

 

1. McElvaney, N. G., and Taggart, C. C. (2005) in Chronic Obstructive Pulmonary Disease Cellular and Molecular Mechanisms (Barnes, P., ed) pp. 343–365, Taylor Francis, Boca Raton, FL
2. Schalkwijk, J., Wiedow, O., and Hirose, S. (1999) Biochem. J. 340, 569–577
3. Guyot, N., Zani, M. L., Berger, P., Dallet-Choisy, S., and Moreau, T. (2005) Biol. Chem. 386, 391–399[CrossRef][Medline] [Order article via Infotrieve]
4. Bingle, L., Tetley, T. D., and Bingle, C. D. (2001) Am. J. Respir. Cell Mol. Biol. 25, 84–91[Abstract/Free Full Text]
5. Zhang, M., Zou, Z., Maass, N., and Sager, R. (1995) Cancer Res. 55, 2537–2541[Abstract/Free Full Text]
6. Simpson, A. J., Maxwell, A. I., Govan, J. R., Haslett, C., and Sallenave, J. M. (1999) FEBS Lett. 452, 309–313[CrossRef][Medline] [Order article via Infotrieve]
7. Vachon, E., Bourbonnais, Y., Bingle, C. D., Rowe, S. J., Janelle, M. F., and Tremblay, G. M. (2002) Biol. Chem. 383, 1249–1256[CrossRef][Medline] [Order article via Infotrieve]
8. Taggart, C. C., Greene, C. M., McElvaney, N. G., and O'Neill, S. (2002) J. Biol. Chem. 277, 33648–33653[Abstract/Free Full Text]
9. Greene, C. M., McElvaney, N. G., O'Neill, S. J., and Taggart, C. C. (2004) Infect. Immun. 72, 3684–3687[Abstract/Free Full Text]
10. Sozzani, S., Locati, M., Zhou, D., Rieppi, M., Luini, W., Lamorte, G., Bianchi, G., Polentarutti, N., Allavena, P., and Mantovani, A. (1995) J. Leukocyte Biol. 57, 788–794[Abstract]
11. Rollins, B. J. (1996) Mol. Med. Today 2, 198–204[CrossRef][Medline] [Order article via Infotrieve]
12. Kurihara, T., Warr, G., Loy, J., and Bravo, R. (1997) J. Exp. Med. 186, 1757–1762[Abstract/Free Full Text]
13. Boring, L., Gosling, J., Chensue, S. W., Kunkel, S. L., Farese, R. V., Jr., Broxmeyer, H. E., and Charo, I. F. (1997) J. Clin. Investig. 100, 2552–2561[Medline] [Order article via Infotrieve]
14. Kuziel, W. A., Morgan, S. J., Dawson, T. C., Griffin, S., Smithies, O., Ley, K., and Maeda, N. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 12053–12058[Abstract/Free Full Text]
15. Hall, D. J., Bates, M. E., Guar, L., Cronan, M., Korpi, N., and Bertics, P. J. (2005) J. Immunol. 174, 8056–8063[Abstract/Free Full Text]
16. Hanazawa, S., Takeshita, A., Amano, S., Semba, T., Nirazuka, T., Katoh, H., and Kitano, S. (1993) J. Biol. Chem. 268, 9526–9532[Abstract/Free Full Text]
17. Waetzig, V., Czeloth, K., Hidding, U., Mielke, K., Kanzow, M., Brecht, S., Goetz, M., Lucius, R., Herdegen, T., and Hanisch, U. K. (2005) Glia 50, 235–246[CrossRef][Medline] [Order article via Infotrieve]
18. Martin, T., Cardarelli, P. M., Parry, G. C., Felts, K. A., and Cobb, R. R. (1997) Eur. J. Immunol. 27, 1091–1097[Medline] [Order article via Infotrieve]
19. Arndt, P. G., Suzuki, N., Avdi, N. J., Macolm, K. C., and Worthen, G. S. (2004) J. Biol. Chem. 279, 10883–10891[Abstract/Free Full Text]
20. Bradford, M. M. (1976) Anal. Biochem. 72, 248–254[CrossRef][Medline] [Order article via Infotrieve]
21. Mullally, J. E., Moos, P. J., Edes, K., and Fitzpatrick, F. A. (2001) J. Biol. Chem. 276, 30366–30373[Abstract/Free Full Text]
22. Guha, M., and Mackman, N. (2001) Cell. Signal. 13, 85–94[CrossRef][Medline] [Order article via Infotrieve]
23. Lomaga, M. A., Yeh, W. C., Sarosi, I., Duncan, G. S., Furlonger, C., Ho, A., Morony, S., Capparelli, C., Van, G., Kaufman, S., van der Heiden, A., Itie, A., Wakeham, A., Khoo, W., Sasaki, T., Cao, Z., Penninger, J. M., Paige, C. J., Lacey, D. L., Dunstan, C. R., Boyle, W. J., Goeddel, D. V., and Mak, T. W. (1999) Genes Dev. 13, 1015–1024[Abstract/Free Full Text]
24. Adachi, O., Kawai, T., Takeda, K., Matsumoto, M., Tsutsui, H., Sakagami, M., Nakanishi, K., and Akira, S. (1998) Immunity 9, 143–150[CrossRef][Medline] [Order article via Infotrieve]
25. Palsson-McDermott, E. M., and O'Neill, L. A. (2004) Immunology 113, 153–162[CrossRef][Medline] [Order article via Infotrieve]
26. Davis, R. J. (2000) Cell 103, 239–252[CrossRef][Medline] [Order article via Infotrieve]
27. Zhong, J., and Kyriakis, J. M. (2004) Mol. Cell. Biol. 24, 9165–9175[Abstract/Free Full Text]
28. Taggart, C. C., Cryan, S. A., Weldon, S., Gibbons, A., Greene, C. M., Kelly, E., Low, T. B., O'Neill, S. J., and McElvaney, N. G. (2005) J. Exp. Med. 202, 1659–1668[Abstract/Free Full Text]
29. Gao, Y., Lecker, S., Post, M. J., Hieteranta, A. J., Li, J., Volk, R., Li, M., Sato, K., Saluja, A. K., Steer, M. L., Goldberg, A. L., and Simons, M. (2000) J. Clin. Investig. 106, 439–448[Medline] [Order article via Infotrieve]

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