scholarly journals Interleukin-6 is necessary, but not sufficient, for induction of the humanC-reactive protein gene in vivo

1997 ◽  
Vol 325 (3) ◽  
pp. 617-621 ◽  
Author(s):  
Birgit WEINHOLD ◽  
Augustinus BADER ◽  
Valeria POLI ◽  
Ulrich RÜTHER
Keyword(s):  
Transgenic Mice ◽  
Acute Phase ◽  
Interleukin 6 ◽  
Acute Phase Reactant ◽  
Primary Hepatocytes ◽  
Cytokine Network ◽  
Gene Encoding ◽  
Reactive Protein

We have investigated the involvement of interleukin-6 (IL-6) in the induction of the gene encoding the acute-phase protein human C-reactive protein (hCRP). In transgenic mice the hCRP gene can be induced by lipopolysaccharide (LPS), but not by IL-6. In contrast, hCRP was inducible by IL-6 in primary human hepatocytes and in primary hepatocytes isolated from transgenic mice. To further evaluate the role of IL-6, we introduced the hCRP transgene into animals lacking endogenous IL-6 (IL-6-negative mice). Here, hCRP was not inducible by LPS, but was induced by a combination of LPS and IL-6. These results clearly demonstrate that IL-6 is necessary, but not sufficient, for the induction of hCRP expression. These animal models will allow further dissection of the cytokine network responsible for the regulation of the major human acute-phase reactant CRP.

Abstract 277: Elevated C-Reactive Protein Contributes to Preeclampsia via Kinin Signaling Pathways

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Nicholas Parchim ◽  
Wei Wang ◽  
Takayuki Iriyama ◽  
Chen Liu ◽  
Athar H Siddiqui ◽  
...  
Keyword(s):  
Acute Phase Reactant ◽  
Receptor Activation ◽  
C Reactive Protein ◽  
Direct Role ◽  
Human Trophoblast ◽  
Reactive Protein ◽  
Induced Hypertension ◽  
Pregnant Mice

Preeclampsia (PE) is a serious pregnancy disease characterized by hypertension and proteinuria. Despite intensive research efforts, the underlying cause of PE remains a mystery. PE is, however, associated with abnormalities of the immune system. Here we report that the levels of C-reactive protein (CRP), an important acute phase reactant, were significantly elevated in the plasma of human with PE at the third trimester. Next, we found that CRP protein levels in the placentas of PE patients were also significantly increased compared to controls. In an effort to determine the exact role of elevated CRP in PE, we infused CRP into pregnant mice. We found that injection of CRP into pregnant mice induced hypertension (170 mmHg mean systolic vs. 125 mmHg mean systolic control; p<0.05) and proteinuria (25 mg/ug vs 12 mg/ug vehicle; p<0.05), indicating the direct role of CRP in PE. CRP is known to bind with phosphocholine on damaged cell membranes. Recent studies identified that neurokinin B (NKB), a placental enriched neuropeptide and known pathogenic molecule for PE, is phosphocholinated. This posttranslational modification increases its stability and enhances NKB-mediated receptor activation. These findings raise an intriguing hypothesis that CRP may bind with NKB coupled to NK3R activation and contribute to PE. To test this hypothesis, we conducted a pulldown assay, and we found that CRP bound with NKB. Next, using a cellular invasion assay, we revealed that CRP decreased invasion of human trophoblast cells (0.7 to 0.07 invasion index, p<0.05), while treatment with an NK3R selective antagonist, SB222200, ameliorated this shallow invasion. Finally, we provided in vivo evidence that inhibition of NK3R by SB222200 or knockdown of NK3R by specific siRNA in a potent nanoparticle delivery system significantly reduced CRP-induced hypertension and proteinuria in pregnant mice (170 mmHg mean systolic CRP-injected vs. 130 mmHg mean systolic siRNA NK3R; p<0.05 and proteinuria 25 mg/ug vs. 15 mg/ug; p<0.05). Overall, our findings demonstrate that elevated CRP contributes to PE and NKB/NK3R is a novel mechanism underlying CRP-mediated shallow invasion and disease development. These studies suggest novel pathogenic biomarkers and innovative therapeutic targets for PE.

scholarly journals The effect of interleukin-1 on C-reactive protein expression in Hep3B cells is exerted at the transcriptional level

1995 ◽  
Vol 310 (1) ◽  
pp. 143-148 ◽  
Author(s):  
D Zhang ◽  
S L Jiang ◽  
D Rzewnicki ◽  
D Samols ◽  
I Kushner
Keyword(s):  
Interleukin 6 ◽  
Interleukin 1 ◽  
Kinetic Studies ◽  
Acute Phase Reactant ◽  
Transcriptional Level ◽  
Mrna Levels ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Hep3b Cells

The combination of interleukin 6 (IL-6) and interleukin 1 (IL-1) synergistically induces the human acute-phase reactant, C-reactive protein (CRP) in Hep3B cells. While previous studies have indicated that IL-6 induces transcription of CRP, the mode of action of IL-1 has not been clearly defined. It has been suggested that the effect of IL-1 might be post-transcriptional, exerted through the 5′-untranslated region (5′-UTR). To evaluate the role of IL-1 in CRP gene expression, we studied the effects of interleukin-6 (IL-6) and interleukin-1 beta (IL-1 beta) on both the endogenous CRP gene and on transfected CRP-CAT constructs in Hep3B cells. In kinetic studies of the endogenous CRP gene, IL-1 beta alone had no effect on CRP mRNA levels, but when added to IL-6, synergistically enhanced both CRP mRNA levels and transcription, as determined by Northern-blot analyses and nuclear run-on studies. IL-6 alone and the combination of [IL-1 beta + IL-6] each induced increases in mRNA levels roughly comparable with observed increases in transcription. These findings indicate that the effect of IL-1 beta on CRP expression is exerted largely at the transcriptional level in this system. This conclusion was confirmed by studies in Hep3B cells transiently transfected with CRP-CAT constructs, each containing 157 bp of the CRP 5′-flanking region but differing in the length of the 5′-UTR from 104 bp to 3 bp. All constructs responded in the same way; IL-6, but not IL-1 beta, induced significant chloramphenicol acetyltransferase (CAT) expression which was synergistically enhanced 2- to 3-fold by IL-1 beta. These results indicate that IL-1 beta stimulates transcriptional events in the presence of IL-6 and that the upstream 157 bases of the CRP promoter contain elements capable of both IL-6 induction and the synergistic effect of IL-1 beta on transcription.

scholarly journals The function of the soluble interleukin 6 (IL-6) receptor in vivo: sensitization of human soluble IL-6 receptor transgenic mice towards IL-6 and prolongation of the plasma half-life of IL-6.

1996 ◽  
Vol 183 (4) ◽  
pp. 1399-1406 ◽  
Author(s):  
M Peters ◽  
S Jacobs ◽  
M Ehlers ◽  
P Vollmer ◽  
J Müllberg ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Acute Phase ◽  
Interleukin 6 ◽  
Acute Phase Response ◽  
Half Life ◽  
Inflammatory Responses ◽  
Phase Response ◽  
Target Cells ◽  
Plasma Half Life

Interleukin 6 (IL-6) is considered an important mediator of acute inflammatory responses. Moreover, IL-6 functions as a differentiation and growth factor of hematopoietic precursor cells, B cells, T cells, keratinocytes, neuronal cells, osteoclasts, and endothelial cells. IL-6 exhibits its action via a receptor complex consisting of a specific IL-6 receptor (IL-6R) and a signal transducing subunit (gp130). Soluble forms of both receptor components are generated by shedding and are found in patients with various diseases such as acquired immune deficiency syndrome, rheumatoid arthritis, and others. The function of the soluble (s)IL-6R in vivo is unknown. Since human (h)IL-6 acts on human and murine target cells, but murine IL-6 on murine cells only, we constructed transgenic mice expressing the hsIL-6R. We report here that in the presence of hsIL-6R, mice are hypersensitized towards hIL-6, mounting an acute phase protein gene induction at significantly lower IL-6 dosages compared to control animals. Furthermore, in hsIL-6R transgenic mice, the detected acute phase response persists for a longer period of time. The IL-6/IL-6R complex prolongs markedly the Il-6 plasma half-life. Our results reinforce the role of the hsIL-6R as an agonistic protein, help to understand the function of the hsIL-6R in vivo, and highlight the significance of the receptor in the induction of the acute phase response.

The Effect of Factor Xa/Phospholipid Infusion on the Acute Phase Response in Baboons

1997 ◽  
Vol 77 (02) ◽  
pp. 308-311 ◽  
Author(s):  
Egbert K O Kruithof ◽  
Diane Agay ◽  
Jean Claude Mestries ◽  
Marie-Paule Gascon ◽  
Arnaud Ythier
Keyword(s):  
Acute Phase ◽  
Interleukin 6 ◽  
Acute Phase Response ◽  
Tissue Injury ◽  
Peak Plasma ◽  
Factor Xa ◽  
Phase Response ◽  
C Reactive Protein ◽  
Reactive Protein

SummaryDisseminated intravascular coagulation (DIC) is a frequent complication of septicemia or tissue injury and may be accompanied by elevations of interleukin-6, a mediator of the acute phase response. It is not known whether thrombin or fibrin deposition may directly induce an acute phase response. To study this, we employed a baboon model of in vivo thrombin generation, induced by the administration of purified bovine Factor Xa and phospholipid vesicles. Two Xa/phospholipid dosages were used, a low dosage (2 animals) leading to a rapid 49% decrease in fibrinogen and a high dosage (two injections at 5h interval; 3 animals) leading to complete fibrinogen depletion. Thereafter, fibrinogen levels increased in both treatment groups, reached a maximum of 2.52 ± 0.23 g/1 (mean ± SE, n = 5; p <0.01 with respect to basal levels) at day 2, and returned to normal by day seven. In five control (injection of 0.15% NaCl) baboons no significant changes of fibrinogen were observed (maximal values: 1.88 ± 0.12 g/1). Serum concentrations of C-reactive protein, an acute phase protein, increased from 3.7 ± 0.4 mg/1 to a maximum of 33.0 ± 7.3 at day one, which was five-fold higher (p <0.01) than in control animals at day one (6.2 ± 0.5 mg/1). Transient increases were observed within 6 h for interleukin-6 from basal values of 6.2 ± 1.7 ng/1 to peak plasma levels of 42.9 ±21.4 ng/1, a value threefold higher (p = 0.07) than in control animals (14.8 ± 4.0 ng/1).The preliminary results of this observational study suggest that factor Xa/phospholipid infusion is followed by an acute phase response, leading after one day to significant increases of fibrinogen and of C-reactive protein.

Inhibition of C5a des Arg-induced neutrophil alveolitis in transgenic mice expressing C-reactive protein

1994 ◽  
Vol 266 (6) ◽  
pp. L649-L654 ◽  
Author(s):  
R. M. Heuertz ◽  
D. Xia ◽  
D. Samols ◽  
R. O. Webster
Keyword(s):  
Transgenic Mice ◽  
Elevated Serum ◽  
Neutrophil Infiltration ◽  
Serum Levels ◽  
Lavage Fluid ◽  
Acute Phase Reactant ◽  
C Reactive Protein ◽  
Reactive Protein

C-reactive protein (CRP) is the classic acute phase reactant in man with serum levels elevated up to 1,000-fold after the onset of inflammation. CRP inhibits chemotaxis of complement (C5a)-stimulated neutrophils in vitro and rabbits with elevated serum CRP levels exhibit diminished neutrophil infiltration and vascular permeability in a model of C5a-induced alveolitis. To specifically evaluate the effect of CRP on C5a-induced neutrophil inflammation in vivo, experiments were performed in transgenic mice capable of expressing rabbit CRP in an inducible fashion. After direct instillation of a known inflammatory agent (C5a des Arg) into the airways, transgenic mice with high plasma levels of CRP showed significantly diminished infiltration of neutrophils into bronchoalveolar lavage fluid (BALF) and a significant reduction of BALF total protein levels compared with normal mice. These data indicate that CRP can diminish lung injury by a reduction in neutrophil influx and protein leakage into alveoli following complement-induced inflammation.

scholarly journals C-reactive Protein: A Physiological Activator of Interleukin 6 Receptor Shedding

1999 ◽  
Vol 189 (3) ◽  
pp. 599-604 ◽  
Author(s):  
Simon A. Jones ◽  
Daniela Novick ◽  
Sankichi Horiuchi ◽  
Naoki Yamamoto ◽  
Alexander J. Szalai ◽  
...  
Keyword(s):  
Acute Phase ◽  
Interleukin 6 ◽  
Protein A ◽  
Acute Phase Reactant ◽  
Human Neutrophils ◽  
Marginal Effect ◽  
Amino Acid Residues ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Interleukin 6 Receptor

The soluble interleukin 6 receptor (sIL-6R) circulates at elevated levels in various diseases. This suggests that inflammatory mediators control sIL-6R release. Through examination of human neutrophils, it was found that the acute phase reactant C-reactive protein (CRP) activates a threefold increase in sIL-6R production. Maximal release occurred after 30–60 min exposure to CRP (50 μg/ml), and was mimicked by peptides corresponding to amino acid residues 174– 185 and 201–206 of native CRP. A third peptide fragment (77–82) had no effect. Differential mRNA splicing did not account for the CRP-mediated release of sIL-6R, since this isoform was not detected in conditioned media. Furthermore, stimulation of neutrophils with CRP or with peptides 174–185 or 201–206 promoted a loss of membrane-bound IL-6R, suggesting release by proteolytic shedding. The metalloprotease inhibitor TAPI had only a marginal effect on CRP-mediated sIL-6R release, suggesting that shedding occurs via a mechanism distinct from that previously reported. It well established that IL-6 stimulates the acute phase expression of CRP. Our current findings demonstrate a novel relationship between these two mediators, since CRP may affect IL-6–mediated inflammatory events by enabling formation of the sIL-6R/IL-6 complex.

scholarly journals Interleukin-6-dependent and -independent regulation of the human C-reactive protein gene

1997 ◽  
Vol 327 (2) ◽  
pp. 425-429 ◽  
Author(s):  
Birgit WEINHOLD ◽  
Ulrich RÜTHER
Keyword(s):  
Transgenic Mice ◽  
Interleukin 6 ◽  
Protein Gene ◽  
Model System ◽  
Oncostatin M ◽  
Leukaemia Inhibitory Factor ◽  
C Reactive Protein ◽  
Cytokine Network ◽  
Reactive Protein ◽  
Novel Model

We have investigated the function of different mediators of the regulation of the human C-reactive protein (hCRP) gene in transgenic mice. hCRP was induced by lipopolysaccharide and wounding in interleukin-6 (IL-6) +/+ mice, but not in IL-6 -/- mice. This finding suggested that IL-6 is necessary for the induction of hCRP. However, injection of IL-6 did not induce the hCRP gene. Thus, the induction of hCRP by IL-6 seems to require an additional cofactor. Therefore, we screened different cytokines for their activity in IL-6 +/+ and IL-6 -/- mice. Surprisingly, interleukin-1β, as well as oncostatin M or leukaemia inhibitory factor, led to an induction of hCRP in both genetic backgrounds. These results indicate an IL-6-dependent and -independent regulation of hCRP. These hCRP transgenic mice therefore represent a novel model system for defining the cytokine network involved in the regulation of acute-phase genes during the course of inflammation.

scholarly journals Non-alcoholic fatty liver disease in mice with hepatocyte-specific deletion of mitochondrial fission factor

Diabetologia ◽  
2021 ◽  
Author(s):  
Yukina Takeichi ◽  
Takashi Miyazawa ◽  
Shohei Sakamoto ◽  
Yuki Hanada ◽  
Lixiang Wang ◽  
...  
Keyword(s):  
Er Stress ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Primary Hepatocytes ◽  
Alcoholic Fatty Liver ◽  
Expression Of Genes ◽  
Specific Deletion

Abstract Aims/hypothesis Mitochondria are highly dynamic organelles continuously undergoing fission and fusion, referred to as mitochondrial dynamics, to adapt to nutritional demands. Evidence suggests that impaired mitochondrial dynamics leads to metabolic abnormalities such as non-alcoholic steatohepatitis (NASH) phenotypes. However, how mitochondrial dynamics are involved in the development of NASH is poorly understood. This study aimed to elucidate the role of mitochondrial fission factor (MFF) in the development of NASH. Methods We created mice with hepatocyte-specific deletion of MFF (MffLiKO). MffLiKO mice fed normal chow diet (NCD) or high-fat diet (HFD) were evaluated for metabolic variables and their livers were examined by histological analysis. To elucidate the mechanism of development of NASH, we examined the expression of genes related to endoplasmic reticulum (ER) stress and lipid metabolism, and the secretion of triacylglycerol (TG) using the liver and primary hepatocytes isolated from MffLiKO and control mice. Results MffLiKO mice showed aberrant mitochondrial morphologies with no obvious NASH phenotypes during NCD, while they developed full-blown NASH phenotypes in response to HFD. Expression of genes related to ER stress was markedly upregulated in the liver from MffLiKO mice. In addition, expression of genes related to hepatic TG secretion was downregulated, with reduced hepatic TG secretion in MffLiKO mice in vivo and in primary cultures of MFF-deficient hepatocytes in vitro. Furthermore, thapsigargin-induced ER stress suppressed TG secretion in primary hepatocytes isolated from control mice. Conclusions/interpretation We demonstrated that ablation of MFF in liver provoked ER stress and reduced hepatic TG secretion in vivo and in vitro. Moreover, MffLiKO mice were more susceptible to HFD-induced NASH phenotype than control mice, partly because of ER stress-induced apoptosis of hepatocytes and suppression of TG secretion from hepatocytes. This study provides evidence for the role of mitochondrial fission in the development of NASH. Graphical abstract

C-Reactive Protein, Interleukin 6, and N-Terminal Pro-Brain Natriuretic Peptide Following Cardioversion of Atrial Fibrillation: Is There a Role of Biomarkers in Arrhythmia Recurrence?

Angiology ◽  
2010 ◽  
Vol 62 (4) ◽  
pp. 310-316 ◽  
Author(s):  
Stavroula N. Psychari ◽  
Dionyssios Chatzopoulos ◽  
Efstathios K. Iliodromitis ◽  
Thomas S. Apostolou ◽  
Dimitrios T. Kremastinos
Keyword(s):  
Atrial Fibrillation ◽  
Brain Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Interleukin 6 ◽  
C Reactive Protein ◽  
Reactive Protein
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