Inhibition of human group II phospholipase A2 by C-reactive protein in vitro

Background— The relevance of the dissociation of circulating pentameric C-reactive protein (pCRP) to its monomeric subunits (mCRP) is poorly understood. We investigated the role of conformational C-reactive protein changes in vivo. Methods and Results— We identified mCRP in inflamed human striated muscle, human atherosclerotic plaque, and infarcted myocardium (rat and human) and its colocalization with inflammatory cells, which suggests a general causal role of mCRP in inflammation. This was confirmed in rat intravital microscopy of lipopolysaccharide-induced cremasteric muscle inflammation. Intravenous pCRP administration significantly enhanced leukocyte rolling, adhesion, and transmigration via localized dissociation to mCRP in inflamed but not noninflamed cremaster muscle. This was confirmed in a rat model of myocardial infarction. Mechanistically, this process was dependent on exposure of lysophosphatidylcholine on activated cell membranes, which is generated after phospholipase A2 activation. These membrane changes could be visualized intravitally on endothelial cells, as could the colocalized mCRP generation. Blocking of phospholipase A2 abrogated C-reactive protein dissociation and thereby blunted the proinflammatory effects of C-reactive protein. Identifying the dissociation process as a therapeutic target, we stabilized pCRP using 1,6-bis(phosphocholine)-hexane, which prevented dissociation in vitro and in vivo and consequently inhibited the generation and proinflammatory activity of mCRP; notably, it also inhibited mCRP deposition and inflammation in rat myocardial infarction. Conclusions— These results provide in vivo evidence for a novel mechanism that localizes and aggravates inflammation via phospholipase A2–dependent dissociation of circulating pCRP to mCRP. mCRP is proposed as a pathogenic factor in atherosclerosis and myocardial infarction. Most importantly, the inhibition of pCRP dissociation represents a promising, novel anti-inflammatory therapeutic strategy.

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The influence of sugar–protein complexes on the thermostability of C-reactive protein (CRP)

Scientific Reports ◽

10.1038/s41598-021-92522-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Andreea Lorena Mateescu ◽

Nicolae-Bogdan Mincu ◽

Silvana Vasilca ◽

Roxana Apetrei ◽

Diana Stan ◽

...

Keyword(s):

Diagnostic Tests ◽

Protein Complexes ◽

C Reactive Protein ◽

Time Resolved Fluorescence ◽

Time Resolved ◽

Reactive Protein ◽

In Vitro Diagnostic ◽

The Stability ◽

Positive Controls

AbstractThe purpose of the present study was to evaluate de influence of protein–sugar complexation on the stability and functionality of C-reactive protein, after exposure to constant high temperatures, in order to develop highly stable positive controls for in-vitro diagnostic tests. C-reactive protein is a plasmatic protein used as a biomarker for the diagnosis of a series of health problems such as ulcerative colitis, cardiovascular diseases, metabolic syndrome, due to its essential role in the evolution of chronic inflammation. The sugar–protein interaction was investigated using steady state and time resolved fluorescence. The results revealed that there are more than two classes of tryptophan, with different degree of accessibility for the quencher molecule. Our study also revealed that sugar–protein complexes have superior thermostability, especially after gamma irradiation at 2 kGy, the protein being stable and functional even after 22 days exposure to 40 °C.

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Low density lipoprotein and very low density lipoprotein are selectively bound by aggregated C-reactive protein.

Journal of Experimental Medicine ◽

10.1084/jem.156.1.230 ◽

1982 ◽

Vol 156 (1) ◽

pp. 230-242 ◽

Cited By ~ 120

Author(s):

F C de Beer ◽

A K Soutar ◽

M L Baltz ◽

I M Trayner ◽

A Feinstein ◽

...

Keyword(s):

Acute Phase ◽

Solid Phase ◽

Low Density Lipoprotein ◽

Density Lipoprotein ◽

Very Low Density Lipoprotein ◽

Low Density ◽

C Reactive Protein ◽

Calcium Dependent ◽

Reactive Protein

C-reactive protein (CRP), the classical acute-phase protein, can bind phospholipids by virtue of its specific, calcium-dependent reactivity with phosphorylcholine residues. However, analysis of acute-phase serum by gel filtration and by density gradient ultracentrifugation showed that the CRP was in a free, uncomplexed form, despite the coexistent presence of the various classes of serum lipoproteins, all of which contain phospholipids. In contrast, when isolated CRP was aggregated by immobilization at a sufficient density on a solid phase and then exposed to normal human serum, it selectively bound low density lipoprotein (LDL) and traces of very low density lipoprotein. The reaction was calcium dependent and reversible by free phosphorylcholine but not by heparin. LDL isolated from normal plasma was also bound by aggregated CRP. CRP reacts in vitro with a wide variety of different ligands both of extrinsic and of autogenous origin, e.g., microbial products and damaged cell membranes, respectively. If CRP aggregated in vivo by complexing with these ligands than acquires the capacity to selectively bind LDL, the phenomenon may have significant implications for the function of CRP and for the metabolism, clearance, and deposition of LDL.

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Circulating phospholipase A2 and C-reactive protein after polytrauma—Effect of superoxide dismutase

European Surgery ◽

10.1007/bf02658873 ◽

1991 ◽

Vol 23 (1) ◽

pp. 2-4 ◽

Cited By ~ 4

Author(s):

R. Tikku ◽

I. Marzi ◽

J. Dike ◽

O. Trentz ◽

V. Bühren

Keyword(s):

Superoxide Dismutase ◽

Phospholipase A2 ◽

C Reactive Protein ◽

Reactive Protein

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Comparison of Lipoprotein-Associated Phospholipase A2 and High Sensitive C-Reactive Protein as Determinants of Metabolic Syndrome in Subjects without Coronary Heart Disease: In Search of the Best Predictor

International Journal of Endocrinology ◽

10.1155/2015/934681 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 10

Author(s):

Mónica Acevedo ◽

Paola Varleta ◽

Verónica Kramer ◽

Giovanna Valentino ◽

Teresa Quiroga ◽

...

Keyword(s):

Metabolic Syndrome ◽

Phospholipase A2 ◽

High Sensitivity ◽

Roc Curves ◽

Activity Levels ◽

Pla2 Activity ◽

C Reactive Protein ◽

Cross Sectional ◽

Reactive Protein ◽

Cv Disease

High sensitivity C-reactive protein (hsCRP) is a marker of metabolic syndrome (MS) and cardiovascular (CV) disease. Lipoprotein-associated phospholipase A2 (Lp-PLA2) also predicts CV disease. There are no reports comparing these markers as predictors of MS.Methods. Cross-sectional study comparing Lp-PLA2 and hsCRP as predictors of MS in asymptomatic subjects was carried out; 152 subjects without known atherosclerosis participated. Data were collected on demographics, cardiovascular risk factors, anthropometric and biochemical measurements, and hsCRP and Lp-PLA2 activity levels. A logistic regression analysis was performed with each biomarker and receiver operating characteristic (ROC) curves were constructed for MS.Results. Mean age was 46 ± 11 years, and 38% of the subjects had MS. Mean Lp-PLA2 activity was 185 ± 48 nmol/mL/min, and mean hsCRP was 2.1 ± 2.2 mg/L. Subjects with MS had significantly higher levels of Lp-PLA2 (P=0.03) and hsCRP (P<0.0001) than those without MS. ROC curves showed that both markers predicted MS.Conclusion. Lp-PLA2 and hsCRP are elevated in subjects with MS. Both biomarkers were independent and significant predictors for MS, emphasizing the role of inflammation in MS. Further research is necessary to determine if inflammation predicts a higher risk for CV events in MS subjects.

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Kinetics of C-reactive protein, interleukin-6 and -10, and phospholipase A2-II in severely traumatized septic patients

Vojnosanitetski pregled ◽

10.2298/vsp1011893l ◽

2010 ◽

Vol 67 (11) ◽

pp. 893-897 ◽

Cited By ~ 6

Author(s):

Zeljko Lausevic ◽

Goran Vukovic ◽

Biljana Stojimirovic ◽

Jasna Trbojevic-Stankovic ◽

Vladimir Resanovic ◽

...

Keyword(s):

Phospholipase A2 ◽

Injury Severity ◽

C Reactive Protein ◽

Surgical Intensive Care ◽

Septic Complications ◽

Mean Values ◽

Protein Levels ◽

Reactive Protein ◽

Significant Difference ◽

Kinetics Of

Background/Aim. Injury-induced anergy is one of the key factors contributing to trauma victims' high susceptibility to sepsis. This group of patients is mostly of young age and it is therefore essential to be able to predict as accurately as possible the development of septic complications, so appropriate treatment could be provided. The aim of this study was to assess kinetics of interleukin (IL) -6 and -10, phospholipase A2- II and C-reactive protein (CRP) in severely traumatized patients and explore the possibilities for early detection of potentially septic patients. Methods. This prospective study included 65 traumatized patients with injury severity score (ISS) > 18, requiring treatment at surgical intensive care units, divided into two groups: 24 patients without sepsis and 41 patients with sepsis. C-reactive protein, IL-6 and -10 and phospholipase A2 group II, were determined within the first 24 hours, and on the second, third and seventh day of hospitalization. Results. Mean values of IL-6 and phospholipase A2-II in the patients with and without sepsis did not show a statistically significant difference on any assessed time points. In the septic patients with ISS 29-35 and > 35 on the days two and seven a statistically significantly lower level of IL-10 was found, compared with those without sepsis and with the same ISS. C-reactive protein levels were significantly higher in septic patients with ISS 18-28 on the first day. On the second, third and seventh day CRP levels were significantly lower in the groups of septic patients with ISS 29-35 and > 35, than in those with the same ISS but without sepsis. Conclusion. Mean levels of CRP on the first day after the injury may be useful predictor of sepsis development in traumatized patients with ISS score 18-28. Mean levels of CRP on the days two, three and seven after the injury may be a useful predictor of sepsis development in traumatized patients with ISS score more than 28. Mean levels of IL-10 on the second and seventh day after the injury may be a useful predictor of sepsis development in traumatized patients with ISS score > 28.

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Abstract 207: C-Reactive Protein Signaling via Neurokinin B Receptor Contributes to the Pathophysiology of Preeclampsia

Hypertension ◽

10.1161/hyp.60.suppl_1.a207 ◽

2012 ◽

Vol 60 (suppl_1) ◽

Author(s):

Nicholas Parchim ◽

Wei Wang ◽

Chen Liu ◽

Athar Siddiqui ◽

Rodney Kellems ◽

...

Keyword(s):

Placental Tissue ◽

Protein Signaling ◽

Post Translational Modification ◽

C Reactive Protein ◽

Neurokinin B ◽

Bacterial Membranes ◽

Reactive Protein ◽

Nk3 Receptor ◽

Invasion Index

Introduction: C-Reactive Protein (CRP) is an important immunomodulatory molecule. Early studies have indicated that CRP is elevated in preeclamptic patient sera, but its function remains unclear. CRP is known to bind with phosphocholine (PC) of bacteria membrane to kill bacteria by triggering innate immune response. Phosphocholination is a post-translational modification mediated by PC transferase, an enzyme reported expressed only in two tissues, including placenta and testis. Recent studies identified that Neurokinin B (NKB), a known, placenta-enriched pathogenic molecule for preeclampsia (PE), is phosphocholinated. This modification increases its stability, preferentially activates NK3 receptor (NK3R) and promotes PE features. Given CRP can bind to PC on bacterial membranes, the role that phosphocholination plays is a mystery. In light of NKB, being phosphocholinated in the endoplasmic reticulum and signals via the NK3R in the pathogenesis of PE, we feel that elevated CRP may be associated with NKB and contributes to the pathophysiology of PE via NK3R activation. Results: ELISA results show that CRP is significantly elevated in PE vs. control sera_65 ug/mL vs. 10 ug/ml; p<0.0001. Western blot analysis reveals that CRP, NKB, and NK3R are significantly increased in PE vs. control placental tissue. Immunohistochemistry studies indicate that all of these three molecules are abundant in syncytiotrophoblast cells. Co-immunoprecipitation demonstrates an interaction between CRP and NKB. In vitro , we provide the first evidence that CRP decreased the invasion of trophoblast cells from 0.7 ± 0.06 to 0.06 ± 0.001 invasion index; p<0.005, while treatment with SB222200 ameliorates shallow invasion from 0.28 ± 0.09 to 0.55 ± 0.07 invasion index; p<0.05. Significantly, infusion of CRP into pregnant mice induces hypertension (169.152 ± 14.7 mmHg vs. 141.916 ± 6.93 mmHg; p<0.05) and proteinuria (28.78 ± 13.56 mg albumin/μg Cr vs. 13.87 ± 3.277 mg albumin/μg Cr; p<0.05). Conclusion: Our findings demonstrate elevated CRP contributes to PE and NKB/NK3R is a new mechanism underlying CRP-mediated shallow invasion and disease development. These studies suggest novel pathogenic biomarkers and innovative therapies for PE.

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Maternal C-reactive protein and in vitro fertilization (IVF) cycles

Journal of Assisted Reproduction and Genetics ◽

10.1007/s10815-020-01924-1 ◽

2020 ◽

Vol 37 (11) ◽

pp. 2635-2641

Author(s):

Fatemeh Diba-Bagtash ◽

Azizeh Farshbaf-Khalili ◽

Alyeh Ghasemzadeh ◽

Laura Lotz ◽

Amir Fattahi ◽

...

Keyword(s):

In Vitro Fertilization ◽

C Reactive Protein ◽

Vitro Fertilization ◽

Reactive Protein

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Influence of apolipoprotein E genotype and dietary α-tocopherol on redox status and C-reactive protein levels in apolipoprotein E3 and E4 targeted replacement mice

British Journal Of Nutrition ◽

10.1017/s000711450788634x ◽

2008 ◽

Vol 100 (1) ◽

pp. 44-53 ◽

Cited By ~ 10

Author(s):

Laia Jofre-Monseny ◽

Patricia Huebbe ◽

Inken Stange ◽

Christine Boesch-Saadatmandi ◽

Jan Frank ◽

...

Keyword(s):

Apoe Genotype ◽

Positive Association ◽

Thiobarbituric Acid ◽

Redox Status ◽

C Reactive Protein ◽

Cvd Risk ◽

Reactive Protein ◽

Antioxidant Defence System

The molecular basis of the positive association between apoE4 genotype and CVD remains unclear. There is direct in vitro evidence indicating that apoE4 is a poorer antioxidant relative to the apoE3 isoform, with some indirect in vivo evidence also available. Therefore it was hypothesised that apoE4 carriers may benefit from α-tocopherol (α-Toc) supplementation. Targeted replacement mice expressing the human apoE3 and apoE4 were fed with a diet poor (0 mg/kg diet) or rich (200 mg/kg diet) in α-Toc for 12 weeks. Neither apoE genotype nor dietary α-Toc exerted any effects on the antioxidant defence system, including glutathione, catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase activities. In addition, no differences were observed in mitogen-induced lymphocyte proliferation. α-Toc concentrations were modestly higher in plasma and lower in tissues of apoE4 compared with apoE3 mice, with the greatest differences evident in the lung, suggesting that an apoE4 genotype may reduce α-Toc delivery to tissues. A tendency towards increased plasma F2-isoprostanes in apoE4 mice was observed, while liver thiobarbituric acid-reactive substances did not differ between apoE3 and apoE4 mice. In addition, C-reactive protein (CRP) concentrations were reduced in apoE4 mice indicating that this positive effect on CRP may in part negate the increased CVD risk associated with an apoE4 genotype.

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