Published online before print March 24, 2005, doi: 10.1161/01.ATV.0000163840.63685.0c
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
© 2005 American Heart Association, Inc.
Atherosclerosis and Lipoproteins |
Statins Reduce Interleukin-6–Induced C-Reactive Protein in Human Hepatocytes
New Evidence for Direct Antiinflammatory Effects of Statins
From Division of Cardiology, Foundation for Medical Research (C.A., F.B., S.S., N.R.V., F.M.), Faculty of Medicine, Geneva University Hospital, Switzerland; Department of Microbiology and Molecular Medicine (T.H.N., D.T.), Faculty of Medicine, University of Geneva, Switzerland.
Correspondence to Dr François Mach, MD, Division of Cardiology, Foundation for Medical Research, 64, Avenue de la Roseraie, 1211 Geneva. E-mail Francois.Mach{at}medecine.unige.ch
 |
Abstract |
|---|
 Top Abstract IntroductionMethodsResultsDiscussionReferences |
|---|
Objectives— Besides its predictive role in determining cardiovascular risk, C-reactive protein (CRP) may exert direct proatherogenic effects through proinflammatory properties. CRP is mainly produced by hepatocytes in response to interleukin-6 (IL-6) and is then released into the systemic circulation. 3-hydroxy-3-methylglutaryl (HMG)-coenzyme A (CoA) reductase inhibitors, or statins, significantly reduce cardiovascular events and mortality in patients with or without coronary artery disease and reduce plasma CRP levels in humans. However, the mechanism by which statins reduce plasma CRP levels remains unknown.
Methods and Results— In this study, we report that statins limit both protein and RNA levels of IL-6-induced CRP in human hepatocytes. These effects are reversed by L-mevalonate and mimicked by an inhibitor of the geranylgeranyltransferase. IL-6–induced CRP production requires the binding of IL-6 to its cognate receptors, which results in activation and phosphorylation of the transcription factor STAT3. We provide evidence that statins reduce this IL-6–induced phosphorylation of STAT3 in hepatocytes.
Conclusion— These results demonstrate that statins reduce IL-6–induced CRP production directly in hepatocytes via inhibition of protein geranylgeranylation. We further show that statins act via inhibition of STAT3 phosphorylation. These findings furnish new evidence for direct antiinflammatory properties of statins and provide new mechanistic insight into their clinical benefits.
C-reactive protein (CRP), mainly produced by hepatocytes in response to interleukin-6 (IL-6), is a powerful independent predictor of future cardiovascular events. In this study, we demonstrate that statins reduce IL-6–induced CRP production directly in hepatocytes. This effect is mimicked by an inhibitor of the geranylgeranyltransferase and we further demonstrate that statins act via reduction of STAT3 phosphorylation.
Key Words: atherosclerosis • C-reactive protein • inflammation • statins
|
Introduction |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
We currently view atherosclerosis as an inflammatory vascular disease,1 characterized by accumulation of lipids, fibrous elements, and inflammatory cell infiltrates.2–4 Recent clinical trials showed that C-reactive protein (CRP) is a powerful independent predictor of future cardiovascular events.2,5 CRP, the major acute-phase reactant in humans, derives mainly from hepatocytes in response to interleukin-6 (IL-6)6 and is then secreted into the systemic circulation. Recent studies reported that besides its predictive role in determining cardiovascular risk, CRP can exert a direct proatherogenic role. CRP can accelerate the progression of atherosclerosis in apolipoprotein E (apoE)-deficient mice.7 In vitro studies reporting that CRP modulates the activity and expression of multiple factors implicated in atherogenesis provided further evidence for the proatherogenic role of CRP. CRP downregulates endothelial nitric oxide synthase,8 resulting in decreased release of NO, and thus facilitates endothelial cell apoptosis and inhibition of angiogenesis.9 In addition, CRP stimulates the production of the vasoconstrictor endothelin-1 and the inflammatory marker IL-6 by endothelial cells.10 Furthermore, CRP increases the expression of vascular cell adhesion molecule-1, intercellular adhesion molecule-1, E-selectin,11 and monocyte chemoattractant protein-1 (MCP-1), resulting in enhanced leukocyte transmigration.12 Recent data suggest that CRP itself potently chemoattracts monocytes13 and facilitates the uptake of low-density lipoprotein (LDL) by macrophages.14 In smooth muscle cells, CRP upregulates angiotensin type 1 receptor and stimulates smooth muscle cells migration and proliferation and reactive oxygen species production.15
3-hydroxy-3-methylglutaryl-coenzymeA (HMG-CoA) reductase inhibitors, or statins, effectively lower serum cholesterol levels and significantly reduce cardiovascular events and mortality in patients with or without coronary artery disease.16 Recently, statins have also been characterized by their immunomodulatory effects,17–19 as well as antiinflammatory properties,20,21 as demonstrated by their ability to decrease plasma levels of CRP.22–24 However, the mechanism by which statins reduce plasma CRP remains unknown.
The signaling pathway that leads to IL-6–induced CRP gene expression in hepatocytes requires the binding of IL-6 to its cognate receptors. Binding of IL-6 to its cell surface receptor, IL-6R
, induces the formation of a complex with the signal-transducing molecule, gp130. The IL-6R/gp130 complex further induces the activation and phosphorylation of the JAK kinases, leading to downstream activation of C/EBPß and STAT3, and thus induction of CRP gene expression.25–28
The aim of this study was to investigate whether statins regulate IL-6–induced CRP production directly at its production site, in hepatocytes, and to highlight the effect of statins on the activation of the transcription factor STAT3 required for IL-6–induced CRP expression.
|
Methods |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
Reagents
Human recombinant IL-6 was purchased from R&D Systems (Minneapolis, Minn) and human recombinant CRP was from Calbiochem (San Diego, Calif). Statins were obtained from a commercial source and dissolved in ethanol or H2O (ethanol 100% for atorvastatin, 10% for simvastatin and H2O for pravastatin). L-Mevalonate was from Sigma (St. Louis, Mo). Geranylgeranyltransferase inhibitor (GGTI-286) and farnesyltransferase inhibitor (FTI-277) were obtained from Calbiochem (San Diego, Calif). For CRP enzyme-linked immunosorbent assay (ELISA), capture antibody was purchased from Abcam (Cambridge, UK), and detection antibody was from Dako (Glostrup, Denmark). Anti–IL-6R
and anti-gp130 antibodies were obtained from Santa Cruz Biotechnology (Santa Cruz, Calif), and anti-STAT3, anti–P-tyr-STAT3, and anti–P-ser-STAT3 were purchased from Cell Signaling Technology (Beverly, Mass).
Cell Culture and Stimulation
Human hepatoma cell line Hep3B (ATCC, Rockville, Md) was maintained in RPMI-1640 medium (Gibco BRL-Life Technologies, Rockville, Md), supplemented with 10% fetal bovine serum, penicillin (100 U/mL), and streptomycin (100 U/mL) at 37°C in a humidified atmosphere containing 5% CO2; primary human hepatocytes were isolated and maintained in culture as previously described.29
Cells were grown to 80% confluence, then washed and incubated in serum-free medium for 24 hours. Cells were then stimulated with 50 ng/mL IL-6 in the presence of different concentrations of statins. Similar concentrations of statin diluents were added to the nonstatin-treated cells for each experiment. To investigate the effect of statins on CRP production by hepatocytes, cells were stimulated with IL-6 for 0 to 48 hours in the presence of different concentrations of statins administered at the same time as IL-6. Then, to study the effects of statins on transcription factor STAT3, cells were first pre-incubated for 4 hours with statins and then stimulated with IL-6 and statins for 15, 30, and 45 minutes.
Analysis of CRP by ELISA
Release of CRP was measured using a sandwich-type ELISA. CRP levels were determined in supernatants of treated cells using optical density measured at 450 nm (Dynaplate reader). The amount of CRP detected was calculated from a standard curve prepared with the recombinant protein. Samples were assayed in duplicate.
RNA Isolation and Real-Time Quantitative Reverse-Transcription Polymerase Chain Reaction
Total cellular RNA was extracted with Tri Reagent (MRC, Cincinnati, Ohio) according to the manufacturer’s instructions. To avoid amplification of contaminating genomic DNA, RNA samples were subsequently treated with DNase (Ambion, Huntingdon, UK). Real-time quantitative reverse-transcription polymerase chain reaction (ABI Prism 7700 Sequence Detection System; Applied Biosystems, Foster City, Calif) was used to determine mRNA levels of CRP. Sequences of the CRP primer/probe combination used: forward primer, 5'-GGG CCC TTC AGT CCT AAT GTC-3'; reverse primer, 5'-TTC GCC TTG CAC TTC ATA CTT-3'; and probe, FAM-5'-TGA ACT GGC GGG CAC-3'-TAMRA. Each sample was analyzed in triplicate and normalized in multiplex reaction using TaqMan eukaryotic 18S control (TaqMan Reagent; Applied Biosystems) VIC-labeled.
Western Blot Analysis
Cells were harvested in ice-cold radioimmunoprecipitation (RIPA) lysis buffer. Total protein concentrations were determined using the bicinchoninic acid (BCA) quantification assay (Pierce, Rockford, Il) and Western blotting was performed as previously described.30 Blots were blocked in 5% dry milk–phosphate-buffered saline (PBS)–0.1% Tween and incubated for 1 hour at room temperature with the following primary antibodies: anti–IL-6R, anti-gp130, anti-STAT3, anti–P-tyr-STAT3, anti–P-ser-STAT3, or mouse monoclonal anti-human ß-actin as control of loading, followed by 1 hour incubation with horseradish peroxidase-conjugated secondary antibodies. Membranes were developed using an enhanced chemiluminescence system (Pierce) to obtain autoradiograms. After scanning, the blots were analyzed for optical density (National Institutes of Health Image for Windows; http://www.scioncorp.com/pages/scion_image_windows.htm). Values were calculated as percentage of the IL-6–stimulated group, normalized to the ß-actin signal.
Statistical Analysis
All results were expressed as mean±SEM. Differences between the groups were considered significant at P<0.05 using the 2-tailed Student t test.
|
Results |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
Statins Reduce IL-6–Induced CRP Release in Hepatocytes
We chose the human hepatoma cell line Hep3B as a model to investigate whether statins modulate IL-6–induced CRP production by hepatocytes. In a first set of experiments, cells were stimulated with 50 ng/mL IL-6 in the presence or absence of increasing doses of pravastatin, simvastatin, or atorvastatin. After 24 hours of treatment, CRP levels were determined in the cell supernatants by ELISA. All statins tested significantly reduced IL-6–induced CRP release in a dose-dependent manner (Figure 1A), whereas the strongest inhibition of CRP production was achieved with atorvastatin at a concentration of 100 nM. In addition, 400 µmol/L L-mevalonate reversed the effect of atorvastatin (Figure 1A), which confirms that statins exert their effects by inhibiting the HMG-CoA reductase. L-Mevalonate alone had no effect on the induction of CRP by IL-6 (data not shown). Interestingly, except for pravastatin, the most efficient doses to reduce CRP (1 µmol/L simvastatin and 0.1 µmol/L atorvastatin) correspond to effective serum levels observed with statin treatment in clinical practice.31 To confirm our results on statin-mediated inhibition of CRP production in Hep3B cells, human primary hepatocytes were stimulated for 24 hours with 50 ng/mL IL-6, in the presence or absence of atorvastatin or simvastatin. Human primary hepatic cells treated with 0.1 µmol/L atorvastatin or 1 µmol/L simvastatin also show significant inhibition of IL-6–induced CRP production (Figure 1B). Finally, we measured lactate dehydrogenase (LDH) activity in culture supernatants to evaluate cell necrosis and performed annexin-V staining to evaluate cell apoptosis. We found no cytotoxic or apoptotic effects either on Hep3B or on primary hepatocytes at any statin concentrations used (data not shown).
|
Inhibition of Protein Geranylgeranylation, but not Protein Farnesylation, Mimics the Effect of Statins
By inhibiting HMG-CoA reductase, statins reduce the formation of L-mevalonate, as well as further downstream intermediates of the L-mevalonate pathway, such as geranylgeranylpyrophosphate and farnesylpyrophosphate, which represent major intermediates for the post-translational modification of proteins. To study the involvement of protein geranylgeranylation and farnesylation in IL-6–induced CRP production, we investigated whether GGTI-286 and FTI-277, 2 specific inhibitors of the geranylgeranyltransferase or farnesyltransferase, respectively, mimicked the effect of statins. Our experiments revealed that treatment with GGTI-286 significantly reduced IL-6–induced CRP production in hepatocytes, whereas FTI-277 had no effect (Figure 2). These results suggest that the inhibitory effect of statins on IL-6–induced CRP results in part from inhibition of protein geranylgeranylation.
|
Statins Reduce CRP mRNA Levels in Hepatocytes
To analyze in detail the reduction of IL-6–induced CRP in hepatocytes after statin treatment, we also assessed CRP mRNA expression by real-time quantitative reverse-transcription polymerase chain reaction. First, we performed a kinetic experiment. As shown by Figure 3A, 24-hour stimulation with IL-6 (50 ng/mL) elicited a significant increase in CRP mRNA expression, which was significantly reduced by simvastatin (1 µmol/L), both in Hep3B cell line (Figure 3A) and in human primary hepatocytes (Figure 3B). Similar results were obtained with atorvastatin and pravastatin (data not shown). Furthermore, to avoid an effect of statins on mRNA levels via a modification in degradation/stabilization of CRP mRNA, we performed experiments to determine mRNA stability in the presence or absence of statins. As shown in Figure 3C, we did not observe any modification of CRP mRNA stability in presence of statins, as demonstrated by actinomycin D experiments used to block de novo mRNA synthesis and explore mRNA half-life. These results indicate that the reducing effect of statins on CRP mRNA is transcriptional.
|
Phosphorylation of STAT3 Mediates IL-6–Induced CRP Expression
We further investigated the mechanism underlying the statin-mediated inhibition of CRP. Activation of STAT3, via its phosphorylation, mediates binding to the acute-phase response element to induce CRP gene expression.32 IL-6 stimulation of Hep3B cells for different periods revealed that phosphorylation of STAT3 on both tyrosine and serine residues reached maximum levels after 15 minutes (Figure 4A). Pretreatment with 1 and 10 µmol/L simvastatin strongly reduced IL-6–induced phosphorylation of STAT3 on serine residues, whereas we observed no effect on the phosphorylation of tyrosine residues. In addition, statins did not affect the level of STAT3 (Figure 4B). Finally, we demonstrated that the reduction of STAT3 phosphorylation does not result from the reduction of IL-6 receptor expression, because we did not observe any modification of IL-6R and gp130 expression after statin treatment (Figure 4C).
|
|
Discussion |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
This study demonstrates that statins reduce IL-6–induced CRP expression in human hepatocytes, and that this regulatory effect of statins on CRP expression occurs at the transcriptional level. We further provide evidence that statins act on the geranylgeranyl pathway and reduce CRP gene expression by decreasing the activation of the transcription factor STAT3.
Numerous clinical trials have shown that elevated plasma levels of CRP predicts subsequent acute coronary events among healthy subjects as well as patients with stable or unstable angina.5,33,34 Because CRP, besides its role as inflammatory marker, is a direct mediator in the development of atherosclerosis,11–13 and because patients who have low CRP levels after statin therapy have better clinical outcomes than those with higher CRP levels, regardless of the resultant level of LDL cholesterol,35,36 therapeutic strategies that reduce CRP levels could be of great interest in the prevention and treatment of cardiovascular diseases. The present study shows, in accordance with previous reports,37 that IL-6 strongly induces the expression of CRP in human hepatocytes, and, for the first time to our knowledge, we demonstrate that statins regulate IL-6–induced CRP expression directly in human hepatocytes (the major site of CRP production). This reduction in CRP expression by statins occurs at the protein and the mRNA levels. We also show that statins have no effect on CRP mRNA stability or degradation, indicating that statins exert their effect at the transcriptional level. The in vitro experiments used statins at doses that correspond to those measured in human plasma during therapy, and we observed that according to results in humans, atorvastatin seems to be the most potent inhibitor of CRP production. Many clinical trials have shown that statin treatments reduce plasma levels of CRP. The CARE study has demonstrated that pravastatin reduces CRP levels at 12 and 24 weeks in LDL cholesterol-independent manner.38 Moreover, it seems that atorvastatin exerts a more potent effect on the reduction of CRP than pravastatin, as demonstrated by recent clinical trials.36,39 These results have been confirmed by several studies, with atorvastatin inducing a greater reduction in CRP levels than pravastatin40 or simvastatin.22 However, although numerous clinical studies have reported that statins lower plasma levels of CRP, our findings demonstrate a direct effect of statins on IL-6–induced CRP expression in human hepatocytes.
Although CRP is mainly produced in response to IL-6, other cytokines, such as IL-1ß, can induce this response.41 A very recent study has demonstrated that statins reduce the IL-1ß–inducible CRP expression in hepatocytes42; however, because IL-1ß augments local IL-6 production, this phenomenon may be indirect. In our study, we also show that the statin-mediated reduction of CRP release can be mimicked by GGTI, an inhibitor of protein geranylgeranylation. Thus, the effect of statins on CRP release occurs via the inhibition of protein geranylgeranylation. Induction of hepatic acute phase protein transduction by IL-6 is mainly mediated by the transcription factor STAT3.25,43 The IL-6–mediated activation of STAT3 requires phosphorylation of both tyrosine and serine residues.32,44 The present study shows that statins significantly reduced STAT3 phosphorylation on serine, but not on tyrosine, residues. Two different studies have previously demonstrated that statins reduce IL-6 or angiotensin-induced phosphorylation of STAT3 in macrophages45 or in vascular smooth muscle cells,46 respectively. The signaling pathways leading to STAT3 phosphorylation are well known and differ among tyrosine or serine residues. In the first case, the tyrosine phosphorylation is mediated by the tyrosine kinase activity of stimulated IL-6 receptor complex (IL-6R/gp130/JAK).43,47 Our results demonstrate that statin does not influence the IL-6 receptor complex or tyrosine phosphorylation of STAT3. In the other case, recent reports indicate that IL-6–induced serine phosphorylation of STAT3 is mediated by a signal transduction pathway consisting of Vav, Rac-1, MEKK, and SEK-1.48,49 The implication of Rac-1 in IL-6–induced STAT3 phosphorylation and transactivation in hepatocytes has been described by several articles. First, it has been shown that IL-6 can activate Rac-1 after 5 minutes of stimulation in hepatocytes.48 In addition, overexpression of active Rac-1 in hepatocytes strongly enhanced both basal and IL-6–induced STAT3 phosphorylation on serine residue, whereas the dominant-negative Rac-1 had opposite effect.49
Thus, from the literature, we can conclude that IL-6 induces CRP release by the following mechanism. Binding of IL-6 to its cognate receptors leads to Rac-1 activation, which in turn induces the phosphorylation of STAT3 on serine residue and then CRP gene expression.
Concerning the effect of statins, we have shown in the present study that statins reduce STAT3 phosphorylation and then CRP gene expression through a decrease of protein geranylgeranylation. Moreover, it has been observed that statins reduce Rac-1 activation in different cell types.50,51,52 Because optimal activation of Rac-1 is dependent on geranylgeranylation,53 we hypothesized that by suppressing the geranylgeranylation of Rac-1 in hepatocytes, statins reduce IL-6–induced phosphorylation of STAT3, thus resulting in reduced CRP expression (Figure 5).
|
A growing body of evidence demonstrates that CRP not only is a cardiovascular risk marker but also plays a direct role in the development of atherosclerosis.11–13 A recent study using apoE-deficient mice expressing human CRP showed that elevated plasma levels of CRP accelerated the progression of atherosclerosis.7 Thus, the reduction of CRP expression by statins may contribute to the prevention of cardiovascular diseases. Furthermore, sepsis is often described as a systemic inflammatory response syndrome,54 and recent studies have shown that statin therapy is associated with a decreased rate of severe sepsis in human55 and in a murine models of sepsis.56 Infection elicits acute-phase response, which in turn triggers inflammation and activates the coagulation system. Thus, statins might exert their beneficial effects during sepsis through attenuation of the acute-phase response and its immediate consequences.57
In conclusion, our results demonstrate that statins modulate CRP levels by reducing its hepatic gene expression. These findings provide a new molecular explanation for the reduced plasma CRP levels observed in patients treated by statins and thus may help to better understand their great clinical benefits.
|
Acknowledgments |
|---|
This work was supported by grants from the Foundation for the Medical Research, France (C.A.), by grants from the Swiss National Science Foundation (#3200-065121.01/1 and #3231 54964.98/1) and the European Community, 6. Frame Program (EVGN #LSHM-CT-2003-503254) (F.M.).
Received September 22, 2004; accepted March 9, 2005.
|
References |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
1. Ross R. Atherosclerosis–an inflammatory disease. N Engl J Med. 1999; 340: 115–126.
2. Libby P. Inflammation in atherosclerosis. Nature. 2002; 420: 868–874.[CrossRef][Medline] [Order article via Infotrieve]
3. Hansson GK. Inflammation and immune response in atherosclerosis. Curr Atheroscler Rep. 1999; 1: 150–155.[Medline] [Order article via Infotrieve]
4. Glass CK, Witztum JL. Atherosclerosis. the road ahead. Cell. 2001; 104: 503–516.[CrossRef][Medline] [Order article via Infotrieve]
5. Ridker PM. Clinical application of C-reactive protein for cardiovascular disease detection and prevention. Circulation. 2003; 107: 363–369.
6. Rattazzi M, Puato M, Faggin E, Bertipaglia B, Zambon A, Pauletto P. C-reactive protein and interleukin-6 in vascular disease: culprits or passive bystanders? J Hypertens. 2003; 21: 1787–1803.[CrossRef][Medline] [Order article via Infotrieve]
7. Paul A, Ko KW, Li L, Yechoor V, McCrory MA, Szalai AJ, Chan L. C-reactive protein accelerates the progression of atherosclerosis in apolipoprotein E-deficient mice. Circulation. 2004; 109: 647–655.
8. Venugopal SK, Devaraj S, Yuhanna I, Shaul P, Jialal I. Demonstration that C-reactive protein decreases eNOS expression and bioactivity in human aortic endothelial cells. Circulation. 2002; 106: 1439–1441.
9. Verma S, Wang CH, Li SH, Dumont AS, Fedak PW, Badiwala MV, Dhillon B, Weisel RD, Li RK, Mickle DA, Stewart DJ. A self-fulfilling prophecy: C-reactive protein attenuates nitric oxide production and inhibits angiogenesis. Circulation. 2002; 106: 913–919.
10. Verma S, Li SH, Badiwala MV, Weisel RD, Fedak PW, Li RK, Dhillon B, Mickle DA. Endothelin antagonism and interleukin-6 inhibition attenuate the proatherogenic effects of C-reactive protein. Circulation. 2002; 105: 1890–1896.
11. Pasceri V, Willerson JT, Yeh ET. Direct proinflammatory effect of C-reactive protein on human endothelial cells. Circulation. 2000; 102: 2165–2168.
12. Pasceri V, Cheng JS, Willerson JT, Yeh ET, Chang J. Modulation of C-reactive protein-mediated monocyte chemoattractant protein-1 induction in human endothelial cells by anti-atherosclerosis drugs. Circulation. 2001; 103: 2531–2534.
13. Torzewski M, Rist C, Mortensen RF, Zwaka TP, Bienek M, Waltenberger J, Koenig W, Schmitz G, Hombach V, Torzewski J. C-reactive protein in the arterial intima: role of C-reactive protein receptor-dependent monocyte recruitment in atherogenesis. Arterioscler Thromb Vasc Biol. 2000; 20: 2094–2099.
14. Zwaka TP, Hombach V, Torzewski J. C-reactive protein-mediated low density lipoprotein uptake by macrophages: implications for atherosclerosis. Circulation. 2001; 103: 1194–1197.
15. Wang CH, Li SH, Weisel RD, Fedak PW, Dumont AS, Szmitko P, Li RK, Mickle DA, Verma S. C-reactive protein upregulates angiotensin type 1 receptors in vascular smooth muscle. Circulation. 2003; 107: 1783–1790.
16. Veillard NR, Mach F. Statins: the new aspirin? Cell Mol Life Sci. 2002; 59: 1771–1786.[CrossRef][Medline] [Order article via Infotrieve]
17. Vollmer T, Key L, Durkalski V, Tyor W, Corboy J, Markovic-Plese S, Preiningerova J, Rizzo M, Singh I. Oral simvastatin treatment in relapsing-remitting multiple sclerosis. Lancet. 2004; 363: 1607–1608.[CrossRef][Medline] [Order article via Infotrieve]
18. McCarey DW, McInnes PI, Madhok R, Hampson R, Scherbakov O, Ford I, Capell HA, Sattar N. Trial of Atorvastatin in Rheumatoid Arthritis (TARA): double-blind, randomised placebo-controlled trial. Lancet. 2004; 363: 2015–2021.[CrossRef][Medline] [Order article via Infotrieve]
19. Mach F. Statins as immunomodulatory agents. Circulation. 2004; 109: II15–II17.
20. Kwak BR, Mulhaupt F, Mach F. Atherosclerosis: anti-inflammatory and immunomodulatory activities of statins. Autoimmun Rev. 2003; 2: 332–338.[CrossRef][Medline] [Order article via Infotrieve]
21. Schieffer B, Drexler H. Role of 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitors, angiotensin-converting enzyme inhibitors, cyclooxygenase-2 inhibitors, and aspirin in anti-inflammatory and immunomodulatory treatment of cardiovascular diseases. Am J Cardiol. 2003; 91: 12H–18H.[Medline] [Order article via Infotrieve]
22. Wiklund O, Mattsson-Hulten L, Hurt-Camejo E, Oscarsson J. Effects of simvastatin and atorvastatin on inflammation markers in plasma. J Intern Med. 2002; 251: 338–347.[CrossRef][Medline] [Order article via Infotrieve]
23. Marz W, Winkler K, Nauck M, Bohm BO, Winkelmann BR. Effects of statins on C-reactive protein and interleukin-6 (the Ludwigshafen Risk and Cardiovascular Health study). Am J Cardiol. 2003; 92: 305–308.[CrossRef][Medline] [Order article via Infotrieve]
24. Blake GJ, Ridker PM. C-reactive protein and other inflammatory risk markers in acute coronary syndromes. J Am Coll Cardiol. 2003; 41: 37S–42S.
25. Zhang D, Sun M, Samols D, Kushner I. STAT3 participates in transcriptional activation of the C-reactive protein gene by interleukin-6. J Biol Chem. 1996; 271: 9503–9509.
26. Heinrich PC, Behrmann I, Muller-Newen G, Schaper F, Graeve. L. Interleukin-6-type cytokine signalling through the gp130/Jak/STAT pathway. Biochem J. 1998; 334 (Pt 2): 297–314.
27. Ochrietor JD, Harrison KA, Zahedi K, Mortensen RF. Role of STAT3 and C/EBP in cytokine-dependent expression of the mouse serum amyloid P-component (SAP) and C-reactive protein (CRP) genes. Cytokine. 2000; 12: 888–899.[CrossRef][Medline] [Order article via Infotrieve]
28. Agrawal A, Cha-Molstad H, Samols D, Kushner I. Transactivation of C-reactive protein by IL-6 requires synergistic interaction of CCAAT/enhancer binding protein beta (C/EBP beta) and Rel p50. J Immunol. 2001; 166: 2378–2384.
29. Nguyen TH, Oberholzer J, Birraux J, Majno P, Morel P, Trono D. Highly efficient lentiviral vector-mediated transduction of nondividing, fully reimplantable primary hepatocytes. Mol Ther. 2002; 6: 199–209.[CrossRef][Medline] [Order article via Infotrieve]
30. Kwak B, Mulhaupt F, Myit S, Mach F. Statins as a newly recognized type of immunomodulator. Nat Med. 2000; 6: 1399–1402.[CrossRef][Medline] [Order article via Infotrieve]
31. Illingworth DR, Erkelens DW, Keller U, Thompson GR, Tikkanen MJ. Defined daily doses in relation to hypolipidaemic efficacy of lovastatin, pravastatin, and simvastatin. Lancet. 1994; 343: 1554–1555.[CrossRef][Medline] [Order article via Infotrieve]
32. Heinrich PC, Behrmann I, Haan S, Hermanns HM, Muller-Newen G, Schaper F. Principles of interleukin (IL)-6-type cytokine signalling and its regulation. Biochem J. 2003; 374: 1–20.[CrossRef][Medline] [Order article via Infotrieve]
33. Haverkate F, Thompson SG, Pyke SD, Gallimore JR, Pepys MB. Production of C-reactive protein and risk of coronary events in stable and unstable angina. European Concerted Action on Thrombosis and Disabilities Angina Pectoris Study Group. Lancet. 1997; 349: 462–466.[CrossRef][Medline] [Order article via Infotrieve]
34. Ridker PM, Buring JE, Shih J, Matias M, Hennekens CH. Prospective study of C-reactive protein and the risk of future cardiovascular events among apparently healthy women. Circulation. 1998; 98: 731–733.
35. Nissen SE, Tuzcu EM, Schoenhagen P, Crowe T, Sasiela WJ, Tsai J, Orazem J, Magorien RD, O’Shaughnessy C, Ganz P. Statin therapy, LDL cholesterol, C-reactive protein, and coronary artery disease. N Engl J Med. 2005; 352: 29–38.
36. Ridker PM, Cannon CP, Morrow D, Rifai N, Rose LM, McCabe CH, Pfeffer MA, Braunwald E. C-reactive protein levels and outcomes after statin therapy. N Engl J Med. 2005; 352: 20–28.
37. Streetz KL, Wustefeld T, Klein C, Manns MP, Trautwein C. Mediators of inflammation and acute phase response in the liver. Cell Mol Biol (Noisy-le-grand). 2001; 47: 661–673.[Medline] [Order article via Infotrieve]
38. Albert MA, Danielson E, Rifai N, Ridker PM. Effect of statin therapy on C-reactive protein levels: the pravastatin inflammation/CRP evaluation (PRINCE): a randomized trial and cohort study. JAMA. 2001; 286: 64–70.
39. Taylor AJ, Kent SM, Flaherty PJ, Coyle LC, Markwood TT, Vernalis MN. ARBITER: Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol: a randomized trial comparing the effects of atorvastatin and pravastatin on carotid intima medial thickness. Circulation. 2002; 106: 2055–2060.
40. Nissen SE, Tuzcu EM, Schoenhagen P, Brown BG, Ganz P, Vogel RA, Crowe T, Howard G, Cooper CJ, Brodie C, Grines CL, DeMaria AN. Effect of intensive compared with moderate lipid-lowering therapy on progression of coronary atherosclerosis: a randomized controlled trial. JAMA. 2004; 291: 1071–1080.
41. Zhang D, Jiang SL, Rzewnicki D, Samols D, Kushner I. The effect of interleukin-1 on C-reactive protein expression in Hep3B cells is exerted at the transcriptional level. Biochem J. 1995; 310(Pt 1): 143–148.
42. Kleemann R, Verschuren L, De Rooij BJ, Lindeman J, De Maat MM, Szalai AJ, Princen HM, Kooistra T. Evidence for anti-inflammatory activity of statins and PPAR activators in human C-reactive protein transgenic mice in vivo and in cultured human hepatocytes in vitro. Blood. 2004; 103: 4188–4194.
43. Zhong Z, Wen Z, Darnell JE Jr. Stat3: a STAT family member activated by tyrosine phosphorylation in response to epidermal growth factor and interleukin-6. Science. 1994; 264: 95–98.
44. Wen Z, Zhong Z, Darnell JE Jr. Maximal activation of transcription by Stat1 and Stat3 requires both tyrosine and serine phosphorylation. Cell. 1995; 82: 241–250.[CrossRef][Medline] [Order article via Infotrieve]
45. Huang KC, Chen CW, Chen JC, Lin WW. Statins induce suppressor of cytokine signaling-3 in macrophages. FEBS Lett. 2003; 555: 385–389.[CrossRef][Medline] [Order article via Infotrieve]
46. Horiuchi M, Cui TX, Li Z, Li JM, Nakagami H, Iwai M. Fluvastatin enhances the inhibitory effects of a selective angiotensin II type 1 receptor blocker, valsartan, on vascular neointimal formation. Circulation. 2003; 107: 106–112.
47. Schindler C, Darnell JE Jr. Transcriptional responses to polypeptide ligands: the JAK-STAT pathway. Annu Rev Biochem. 1995; 64: 621–651.[Medline] [Order article via Infotrieve]
48. Schuringa, JJ, Jonk LJ, Dokter WH, Vellenga E, Kruijer W. Interleukin-6-induced STAT3 transactivation and Ser727 phosphorylation involves Vav, Rac-1 and the kinase SEK-1/MKK-4 as signal transduction components. Biochem J. 2000; 347 (Pt 1): 89–96.
49. Schuringa JJ, Dekker LV, Vellenga E, Kruijer W. Sequential activation of Rac-1, SEK-1/MKK-4, and protein kinase Cdelta is required for interleukin-6-induced STAT3 Ser-727 phosphorylation and transactivation. J Biol Chem. 2001; 276: 27709–27715.
50. Negre-Aminou P, van Leeuwen RE, van Thiel GC, van den IP, de Jong WW, Quinlan RA, Cohen LH. Differential effect of simvastatin on activation of Rac(1) vs. activation of the heat shock protein 27-mediated pathway upon oxidative stress, in human smooth muscle cells. Biochem Pharmacol. 2002; 64: 1483–1491.[CrossRef][Medline] [Order article via Infotrieve]
51. Patel TR, Corbett SA. Mevastatin suppresses lipopolysaccharide-induced Rac activation in the human monocyte cell line THP-1. Surgery. 2003; 134: 306–311.[CrossRef][Medline] [Order article via Infotrieve]
52. Ito M, Adachi T, Pimentel DR, Ido Y, Colucci WS. Statins inhibit beta-adrenergic receptor-stimulated apoptosis in adult rat ventricular myocytes via a Rac1-dependent mechanism. Circulation. 2004; 110: 412–418.
53. Seabra MC. Membrane association and targeting of prenylated Ras-like GTPases. Cell Signal. 1998; 10: 167–172.[CrossRef][Medline] [Order article via Infotrieve]
54. Bone RC. Toward a theory regarding the pathogenesis of the systemic inflammatory response syndrome: what we do and do not know about cytokine regulation. Crit Care Med. 1996; 24: 163–172.[CrossRef][Medline] [Order article via Infotrieve]
55. Almog Y, Shefer A, Novack V, Maimon N, Barski L, Eizinger M, Friger M, Zeller L, Danon A. Prior statin therapy is associated with a decreased rate of severe sepsis. Circulation. 2004; 110: 880–885.
56. Merx MW, Liehn EA, Janssens U, Lutticken R, Schrader J, Hanrath P, Weber C. HMG-CoA reductase inhibitor simvastatin profoundly improves survival in a murine model of sepsis. Circulation. 2004; 109: 2560–2565.
57. Almog Y. Statins, inflammation, and sepsis: hypothesis. Chest. 2003; 124: 740–743.
This article has been cited by other articles:
 |
|
 |
|
  E. M. Urbina, R. V. Williams, B. S. Alpert, R. T. Collins, S. R. Daniels, L. Hayman, M. Jacobson, L. Mahoney, M. Mietus-Snyder, A. Rocchini, et al. Noninvasive Assessment of Subclinical Atherosclerosis in Children and Adolescents: Recommendations for Standard Assessment for Clinical Research: A Scientific Statement From the American Heart Association Hypertension, November 1, 2009; 54(5): 919 - 950. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Ali, M. Zakkar, K. Karu, E. A. Lidington, S. S. Hamdulay, J. J. Boyle, M. Zloh, A. Bauer, D. O. Haskard, P. C. Evans, et al. Induction of the Cytoprotective Enzyme Heme Oxygenase-1 by Statins Is Enhanced in Vascular Endothelium Exposed to Laminar Shear Stress and Impaired by Disturbed Flow J. Biol. Chem., July 10, 2009; 284(28): 18882 - 18892. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Q.-q. Wang, Y.-g. Qiu, Y.-j. Zhu, J.-h. Zhu, L.-h. Wang, X.-s. Hu, S.-j. Hu, L.-r. Zheng, Q.-m. Tao, F.-r. Zhang, et al. Cyclophosphamide protects against myocardial ischemia/reperfusion injury in rats: One of the therapeutic targets is high sensitivity C-reactive protein J. Thorac. Cardiovasc. Surg., April 1, 2009; 137(4): 991 - 996. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Montecucco, F. Burger, G. Pelli, N. K. Poku, C. Berlier, S. Steffens, and F. Mach Statins inhibit C-reactive protein-induced chemokine secretion, ICAM-1 upregulation and chemotaxis in adherent human monocytes Rheumatology, March 1, 2009; 48(3): 233 - 242. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Z. LaCroix, S. L. Gray, A. Aragaki, B. B. Cochrane, A. B. Newman, C. L. Kooperberg, H. Black, J. D. Curb, P. Greenland, and N. F. Woods Statin Use and Incident Frailty in Women Aged 65 Years or Older: Prospective Findings From the Women's Health Initiative Observational Study J. Gerontol. A Biol. Sci. Med. Sci., April 1, 2008; 63(4): 369 - 375. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Gao, L. Linhartova, A. McD. Johnston, and D. R. Thickett Statins and sepsis Br. J. Anaesth., March 1, 2008; 100(3): 288 - 298. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Dandona Effects of Antidiabetic and Antihyperlipidemic Agents on C-Reactive Protein Mayo Clin. Proc., March 1, 2008; 83(3): 333 - 342. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. S. Boekhoorn, J. R. Vingerling, J. C. M. Witteman, A. Hofman, and P. T. V. M. de Jong C-reactive Protein Level and Risk of Aging Macula Disorder: The Rotterdam Study Arch Ophthalmol, October 1, 2007; 125(10): 1396 - 1401. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. J. Nicholls, E. M. Tuzcu, I. Sipahi, A. W. Grasso, P. Schoenhagen, T. Hu, K. Wolski, T. Crowe, M. Y. Desai, S. L. Hazen, et al. Statins, High-Density Lipoprotein Cholesterol, and Regression of Coronary Atherosclerosis JAMA, February 7, 2007; 297(5): 499 - 508. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Devaraj, E. Chan, and I. Jialal Direct Demonstration of an Antiinflammatory Effect of Simvastatin in Subjects with the Metabolic Syndrome J. Clin. Endocrinol. Metab., November 1, 2006; 91(11): 4489 - 4496. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Libby and P. M. Ridker Inflammation and Atherothrombosis: From Population Biology and Bench Research to Clinical Practice J. Am. Coll. Cardiol., October 27, 2006; 48(9_Suppl_A): A33 - A46. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Maggio, J. M. Guralnik, D. L. Longo, and L. Ferrucci Interleukin-6 in aging and chronic disease: a magnificent pathway. J. Gerontol. A Biol. Sci. Med. Sci., June 1, 2006; 61(6): 575 - 584. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||