Widespread vascular production of C-reactive protein (CRP) and a relationship between serum CRP, plaque CRP and intimal hypertrophy

Relationship Between C-Reactive Protein to Albumin Ratio and Infarct-Related Artery Patency in Patients With ST-Segment Elevation Myocardial Infarction

The C-reactive protein to albumin ratio (CAR) is a predictive marker of systemic inflammatory state in atherosclerotic coronary disease when compared with the predictive value of these 2 markers separately. We investigated the relationship between CAR and infarct-related artery (IRA) patency in patients with ST-segment elevation myocardial infarction (STEMI). The study population (n = 1047) was divided into 2 groups according to IRA patency which was assessed by the Thrombolysis in Myocardial Infarction (TIMI) flow grade. Nonpatent flow was defined as TIMI grade 0 (no-reflow), 1, and 2 flows, and normal flow was defined as TIMI 3 flow. There was a significant positive correlation between CAR and SYNTAX score (r = 0.312, P < .001) and a negative correlation between CAR and TIMI grade flow (r = -0.210, P < .001). At a cutoff level of 0.693, the CAR predicted TIMI no-reflow with a sensitivity of 65.4% and a specificity of 65.5% (area under the curve: 0.670, 95% CI: 0.62-0.71, P < .001). Multivariate logistic regression analyses showed that CAR was an independent predictor of IRA patency (0.003 [0.001-0.029]; P < .001). A higher CAR is a significant and independent predictor of IRA patency in patients with STEMI.

Unactivated leukocyte expression of C-reactive protein is minimal and not dependent on rs1205 genotype

C-reactive protein (CRP), a prominent component of the innate immune system, is implicated in the pathophysiology of many conditions. CRP production primarily occurs in the liver; but contributions from other tissues is unclear. The Genotype-Tissue Expression Portal shows essentially no expression in whole blood and reports in the literature are conflicting. Multiple genomic variants influence serum levels of CRP. We measured CRP mRNA expression in leukocytes and sought to determine if rs1205 genotype influences leukocyte expression. Leukocytes were obtained from 20 women differing by genotype. Quantitative, real-time PCR (RT-qPCR) detected CRP and reference gene (GAPDH) mRNA. Leukocyte expression was calculated by the 2^ΔCT method, and against a standard curve. Digital drop PCR was also used to calculate expression ratios. Student's t test and linear regression methods examined possible differences between genotypes. During 32 runs (10 replicates each), the RT-qPCR mean (SD) CRP/GAPDH ratio was 3.39 × 10^–4 (SD 1.73 × 10^–4) and 3.15 × 10^–4 (SD 1.64 × 10^–4) for TT and CC genotypes respectively, p = 0.76; and digital drop PCR results were similar. Serum CRP was not significantly different between genotypes, nor correlated with leukocyte expression. CRP is minimally expressed in unactivated leukocytes and this expression is not likely influenced by rs1205 genotype.

C-Reactive Protein to Albumin Ratio in Patients With Saphenous Vein Graft Disease

Atherosclerosis plays an important role in saphenous vein graft disease (SVGD). Previous studies showed that inflammatory blood cells play an active role in this process. C-reactive protein to albumin ratio (CAR) is considered as a novel predictor for cardiovascular risk and an indicator of inflammation. We aimed to assess the relationship between SVGD and CAR. A total of 711 participants with saphenous vein graft (SVG) were included; 348 patients had SVGD and 363 patients had patent (no stenosis) SVG. C-reactive protein to albumin ratio was higher in patients with SVGD (P < .001). There was a significant positive correlation between CAR and the age of SVG (r = 0.123; P = .001) and SYNTAX score (r = 0.568; P < .001). Multivariate logistic regression analyses showed that lymphocyte count, CAR, and SYNTAX score were independent predictors of SVGD (P < .05). C-reactive protein to albumin ratio may be a useful marker after bypass surgery to predict SVGD.

Matrix sieving-enforced retrograde transcytosis regulates tissue accumulation of C-reactive protein

Aims

Circulating proteins larger than 3 nm can be transported across continuous endothelial barrier of blood vessels via transcytosis. However, excessive accumulation of serum proteins within the vessel walls is uncommon even for those abundant in the circulation. The aim of this study was to investigate how transcytosis regulates tissue accumulation of the prototypical acute-phase reactant C-reactive protein (CRP) and other serum proteins.

Methods and results

Transcytosis of CRP as well as of transferrin and low-density lipoprotein across aortic endothelial cells is bidirectional with directional preference from the apical (blood) to basolateral (tissue) direction both in vitro and in vivo. This directional preference is, however, reversed by the basement membrane (BM) matrix underlying the basolateral surface of endothelial cells. This is due to the sieving effect of the BM that physically hinders the diffusion of transcytosed proteins from the apical compartment towards underlying tissues, resulting in immediate retrograde transcytosis that limits basolateral protein accumulation. Conversely, CRP produced within vessel wall lesions can also be transported into the circulation.

Conclusion

Our findings identify matrix sieving-enforced retrograde transcytosis as a general mechanism that prevents excessive tissue accumulation of blood-borne proteins and suggest that lesion-derived CRP might also contribute to elevated serum CRP levels associated with increased risk for cardiovascular diseases.

Intraplaque Expression of C-Reactive Protein Predicts Cardiovascular Events in Patients with Severe Atherosclerotic Carotid Artery Stenosis

Serum c-reactive protein (CRP) was suggested for the assessment of intermediate cardiovascular (CV) risk. Here, systemic or intraplaque CRP levels were investigated as predictors of major adverse cardiovascular events (MACEs) in patients with severe carotid stenosis. CRP levels were assessed in the serum and within different portions (upstream and downstream) of carotid plaques of 217 patients undergoing endarterectomy. The association between CRP and intraplaque lipids, collagen, neutrophils, smooth muscle cells (SMC), and macrophage subsets was determined. No correlation between serum CRP and intraplaque biomarkers was observed. In upstream portions, CRP content was directly correlated with intraplaque neutrophils, total macrophages, and M1 macrophages and inversely correlated with SMC content. In downstream portions, intraplaque CRP correlated with M1 and M2 macrophages. According to the cut-off point (CRP > 2.9%) identified by ROC analysis in upstream portions, Kaplan-Meier analysis showed that patients with high CRP levels had a greater rate of MACEs. This risk of MACEs increased independently of age, male gender, serum CRP, and statin use. In conclusion, in patients with severe carotid artery stenosis, high CRP levels within upstream portions of carotid plaques directly and positively correlate with intraplaque inflammatory cells and predict MACEs at an 18-month follow-up period.

Solubilization and purification of recombinant modified C-reactive protein from inclusion bodies using reversible anhydride modification

The precise function of C-reactive protein (CRP) as a regulator of inflammation in health and disease continues to evolve. The true understanding of its role in host defense responses has been hampered by numerous reports of comparable systems with contradictory interpretations of CRP as a stimulator, suppressor, or benign contributor to such processes. These discrepancies may be explained in part by the existence of a naturally occurring CRP isoform, termed modified CRP (i.e., mCRP), that is expressed when CRP subunits are dissociated into monomeric structures. The free mCRP subunit undergoes a non-proteolytic conformational change that has unique solubility, antigenicity, and bioactivity compared to the subunits that remain associated in the native, pentameric CRP molecule (i.e., pCRP). As specific reagents have been developed to identify and quantify mCRP, it has become apparent that this isoform can be formed spontaneously in calcium-free solutions. Furthermore, mCRP can be expressed on perturbed cell membranes with as little as 24–48 h incubation in tissue culture. Because mCRP has the same size as pCRP subunits as evaluated by SDS-PAGE, its presence in a pCRP reagent would not be apparent using this technique to evaluate purity. Finally, because many antibody reagents purported to be specific for “CRP” contains some, or substantial specificity to mCRP, antigen-detection techniques using such reagents may fail to distinguish the specific CRP isoform detected. All these caveats concerning CRP structures and measurements suggest that the aforementioned contradictory studies may reflect to some extent on distinctive bioactivities of mCRP rather than on pCRP. To provide a reliable, abundant supply of mCRP for separate and comparable studies, a recombinant protein was engineered and expressed in E. coli (i.e., recombinant mCRP or r_mCRP). Synthesized protein was produced as inclusion bodies which proved difficult to solubilize for purification and characterization. Herein, we describe a method using anhydride reagents to effectively solubilize r_mCRP and allow for chromatographic purification in high yield and free of contaminating endotoxin. Furthermore, the purified r_mCRP reagent represents an excellent comparable protein to the biologically produced mCRP and as a distinctive reagent from pCRP. Deciphering the true function of CRP in both health and disease requires a knowledge, understanding, and reliable supply of each of its structures so to define the distinctive effects of each on the body’s response to tissue damaging events.

Correlation between C-reactive protein in peripheral vein and coronary sinus in stable and unstable angina

Background

High sensitivity C-reactive protein (hs-CRP) is commonly used in clinical practice to assess cardiovascular risk. However, a correlation has not yet been established between the absolute levels of peripheral and central hs-CRP.

Objective

To assess the correlation between serum hs-CRP levels (mg/L) in a peripheral vein in the left forearm (LFPV) with those in the coronary sinus (CS) of patients with coronary artery disease (CAD) and a diagnosis of stable angina (SA) or unstable angina (UA).

Methods

This observational, descriptive, and cross-sectional study was conducted at the Instituto do Coração, Hospital das Clinicas, Faculdade de Medicina, Universidade de São Paulo, and at the Hospital Beneficência Portuguesa de Sao Paulo, where CAD patients referred to the hospital for coronary angiography were evaluated.

Results

Forty patients with CAD (20 with SA and 20 with UA) were included in the study. Blood samples from LFPV and CS were collected before coronary angiography. Furthermore, analysis of the correlation between serum levels of hs-CRP in LFPV versus CS showed a strong linear correlation for both SA (r = 0.993, p < 0.001) and UA (r = 0.976, p < 0.001) and for the entire sample (r = 0.985, p < 0.001).

Conclusion

Our data suggest a strong linear correlation between hs-CRP levels in LFPV versus CS in patients with SA and UA.

C-reactive protein induces expression of tissue factor and plasminogen activator inhibitor-1 and promotes fibrin accumulation in vein grafts

BACKGROUND

C-reactive protein (CRP) promotes tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) expression in vitro, and an elevated plasma CRP concentration is associated with an increased risk of vein graft (VG) thrombosis after coronary artery bypass surgery. However, little is known about the effects of CRP on VG TF and PAI-1 expression in vivo, or on VG thrombosis.

OBJECTIVES

We studied transgenic (Tg) mice expressing human CRP in a VG model to explore in vivo cause-and-effect relationships between CRP and TF, PAI-1, and VG thrombosis.

METHODS

Vein segments from wild-type (WT) and CRP-Tg donors were transplanted into carotid arteries of WT and CRP-Tg recipients. VGs were analyzed 1-4 weeks later.

RESULTS

Human CRP accumulated in VGs during the first 4 weeks after surgery, but appeared to originate exclusively from systemic sources, rather than local production. Human CRP significantly increased TF gene expression, protein concentration and activity in VGs. Human CRP also increased PAI-1 concentrations in VGs, although only in vascular endothelial cells. Human CRP stimulated macrophage migration, invasion into VGs, and TF expression. Fibrin deposition was significantly greater in VGs of CRP-Tg mice than in WT controls.

CONCLUSIONS

CRP accumulates in VGs early after surgery, originating from systemic sources rather than local synthesis. Human CRP promotes TF and PAI-1 expression in VGs, although with different expression patterns. Human CRP stimulates macrophage invasion and fibrin deposition within VGs. These results suggest that CRP induces pathologic changes in VGs that contribute to early VG occlusion.

Plasma semicarbazide-sensitive amine oxidase activity in type 1 diabetes is related to vascular and renal function but not to glycaemia

PURPOSE

Associations of semicarbazide-sensitive amine oxidase (SSAO) activity with renal and vascular function, oxidative stress, glycaemia and diabetes complications were determined.

METHODS

Plasma SSAO activity in 94 type 1 diabetes (T1DM) patients, including 34 with microvascular complications T1DM CX[+], and in 96 healthy subjects (CON) was measured by production of benzaldehyde using high-performance liquid chromatography (HPLC).

RESULTS

SSAO activity (mean ± SD) was greater in T1DM than in CON (1049 ± 294 vs 749 ± 204 mU/L; p < 0.00001) and was higher in T1DM CX[+] vs complication-free DM subjects (1148 ± 313 mU/L vs 982 ± 269 mU/L; p = 0.01). In T1DM, SSAO activity correlated with renal dysfunction [estimated glomerular filtration rate (eGFR): r = -0.44; p = 0.0001; cystatin C: r = 0.47; p = 0.0001] and markers of inflammation [soluble vascular cell adhesion molecule-1 (sVCAM-1): r = 0.41, p = 0.0001; soluble intercellular adhesion molecule-1 (sICAM-1): r = 0.33, p = 0.002] and was inversely related to small artery elasticity (SAE) (r = -0.23, p = 0.03). In CON, SSAO activity correlated with HbA1c (r = 0.26; p = 0.02).

CONCLUSION

In T1DM, SSAO activity correlates with renal dysfunction, but not with glycaemia, and may promote vascular inflammation and be a therapeutic target.

Design of the rosuvastatin pretreatment to reduce embolization during Carotid Artery Stenting trial

BACKGROUND

Carotid artery stenting (CAS) is a worldwide diffuse intervention, but may be associated with distal plaque component embolization, and sometimes major and minor stroke. Statin use has been demonstrated to reduce atherosclerotic plaque burden, but its effect in reducing distal embolization during carotid stenting has not yet been well validated.

AIMS

With the Rosuvastatin Pretreatment to Reduce Embolization during Carotid Artery Stenting trial, we aim to discover if a pretreatement with high doses of rosuvastatin in dyslipidemic patients is able to reduce periprocedural cerebral ischemic complications following carotid stenting.

METHODS

This is a phase III prospective, randomized controlled trial. All consecutive patients with asymptomatic carotid stenosis at least 80% will be randomized to a 6-week rosuvastatin treatment followed by carotid stenting, and to direct carotid stenting. Carotid stenting will be performed following common practice with distal or proximal embolic protection. The primary efficacy end point of the trial will be the prevalence of 'relevant' embolization during CAS, as a surrogate end point for cerebral ischemic complications. Other laboratory and clinical data will be registered and patients will be followed up to 1 year. In order to obtain the expected superiority of statin pretreatment on primary end point, a population of 130 patients will be enrolled into the study.

CONCLUSION

In conclusion, with the Rosuvastatin Pretreatment to Reduce Embolization during Carotid Artery Stenting trial, we want to evaluate whether a high dose of rosuvastatin for 6 weeks before CAS in asymptomatic patients with severe carotid stenosis is able to reduce the rate of plaque embolization during the procedure, thus suggesting a possible reduction in cerebral ischemic complications.

Effect of fresh orange juice intake on physiological characteristics in healthy volunteers

Background. Impaired endothelial function is a predictor of cardiovascular events. Orange juice (OJ) is rich in dietary flavonoids and could inhibit oxidative stress and inflammatory responses. We examined the effects of commercial (COJ) and fresh orange juice (FOJ) on endothelial function and physiological characteristics in healthy humans. Materials and Methods. Twenty-two healthy volunteers years were enrolled in a single blind randomized crossover controlled trial. The two groups consumed either COJ for the first 4 weeks and then FOJ (CFOJ, 4 weeks), or FOJ for the first 4 weeks and then COJ (FCOJ, 4 weeks). We assessed endothelial function by measuring flow-mediated dilation, serum concentrations of lipids, apolipoproteins A and B (apo A-1 and apo B), and inflammatory markers such as vascular endothelial adhesion molecule 1 (VCAM-1), E-selectin, high-sensitivity C-reactive protein (hs-CRP), and interleukin-6. Results. Consumption of both juices decreased VCAM, hs-CRP, and E-selectin but increased apo A-1. A decline in LDL occurred in the FOJ group. There were no differences between the characteristics of two groups, with the exception of apo A-1 levels that were increased with both forms of OJ. The largest variations occurred with hs-CRP, VCAM in both groups. Conclusion. Consumption of COJ and FOJ produced beneficial effects on the physiological characteristics of healthy volunteers. Although these results could encourage the consumption of OJ, intervention studies are needed to determine the long-term effects of these types of OJ on metabolic and cardiovascular endpoints.

Effects of red orange juice intake on endothelial function and inflammatory markers in adult subjects with increased cardiovascular risk

BACKGROUND

Oxidative and inflammatory stresses are involved in the pathogenesis of atherosclerosis. The consumption of fruit and vegetables is associated with improved health and reduced cardiovascular risk. Red oranges have a high content of antioxidant and antiinflammatory substances, but there is a paucity of data concerning their effects on cardiovascular biomarkers in subjects with increased cardiovascular risk.

OBJECTIVE

We investigated the effect of red orange juice intake on endothelial function, oxidative stress, and markers of inflammation in subjects with increased cardiovascular risk.

DESIGN

Nineteen nondiabetic subjects with increased cardiovascular risk (aged 27-56 y) were included in a randomized, placebo-controlled, single-blind crossover study and compared with 12 healthy, nonobese control subjects. In 2 periods of 7 d each with a 3-d interval, each participant alternatively received 500 mL red orange juice/d and 500 mL placebo/d in a random sequence. All measurements were performed in the morning after overnight fasting.

RESULTS

Endothelial function, which was measured as flow-mediated dilation, significantly improved and was normalized (5.7% compared with 7.9%; P < 0.005) after 1 wk of red orange juice consumption. Similarly, concentrations of high-sensitivity C-reactive protein, IL-6, and TNF-α significantly decreased (P < 0.001). Red orange juice had no significant effect on nitric oxide plasma concentrations.

CONCLUSION

A 7-d consumption of red orange juice ameliorates endothelial function and reduces inflammation in nondiabetic subjects with increased cardiovascular risk. This trial was registered at biomedcentral.com as ISRCTN39987296.

Endothelial C-reactive protein increases platelet adhesion under flow conditions

While data regarding the pathogenetic role of C-reactive protein (CRP) in atherothrombosis are accumulating, it is still controversial whether local CRP secretion is of any pathobiological significance. The present study examined whether endothelial-derived CRP modulates autocrine prothrombotic activity. Endothelial cells were isolated from hearts of mice transgenic to human CRP and grown in primary cultures. Human CRP expression was confirmed in these cells compared with no expression in cultures derived from wild-type congenes. Adhesion of human platelets to endothelial cells was studied in the “cone and plate” flow system. Platelet adhesion to cells expressing CRP was significantly increased compared with that in controls ( n = 6, P < 0.01). The proadhesive effect of CRP was significantly suppressed in mouse heart endothelial cells and in human umbilical vein endothelial cells following treatment with small interfering RNA for human CRP. Adhesion was modulated by an increase in P-selectin. P-selectin expression correlated with a proadhesive phenotype, and blocking P-selectin with neutralizing antibody significantly decreased the adhesion of platelets to CRP-expressing cells (40.4 ± 10.5 to 9.4 ± 6.9 platelets/high-power field, n = 5 to 6, P < 0.01). In conclusion, human CRP that is locally produced in endothelial cells increases platelet adhesion to endothelial cells under normal shear flow conditions. These findings indicate that CRP exerts a local effect on endothelial cells via P-selectin expression, which promotes platelet adhesion and subsequent thrombus formation.

Effect of rosuvastatin on C-reactive protein and progression of aortic stenosis

BACKGROUND

Elevated C-reactive protein (CRP) is a common finding in patients with aortic stenosis (AS) and may be associated with rapid AS progression and worse outcome. The purpose of the study was to examine the role of high-sensitivity CRP and its interaction with rosuvastatin on the progression of AS.

METHODS

We measured CRP at baseline, 1 year, and end of follow-up in 260 patients with a median follow-up of 3.5 years. Analyses were performed based on baseline CRP tertiles and baseline CRP >3 and ≤3 mg/L.

RESULTS

After adjustment for baseline characteristics, higher CRP levels were associated with age, female gender, body mass index, and lower high-density lipoprotein cholesterol levels but not with AS severity. Treatment with rosuvastatin led to a persistent decrease in CRP at 1 year and end of follow-up. Progression of AS was detected in patients in all 3 CRP tertiles, and rosuvastatin treatment had no impact on progression in all 3 tertiles. Similar findings were observed using CRP >3 mg/L as the cutpoint. Multiple linear regression showed that baseline AS velocity (P < .001), but not CRP, was the only predictor of progression of AS; age (P = .05) and baseline AS velocity (P < .001), but not CRP and rosuvastatin treatment, were predictors of outcome events.

CONCLUSION

C-reactive protein does not predict severity, progression, and prognosis in patients with mild to moderate AS. Treatment with rosuvastatin reduces CRP levels but has no effect on the progression and clinical events of AS.

Differential Characteristics of Inflammatory Responses to Stent Implantation Between De Novo and Intrastent Restenosis Lesion in Patients With Stable Angina

Mechanical plaque rupture of coronary atherosclerotic plaque during stent implantation can increase serum levels of high-sensitivity C-reactive protein (hsCRP). Patients with stable angina pectoris were divided into 2 groups: one group included 186 patients with de novo lesion who underwent stent implantation (de novo group); the other group included 40 patients with intrastent restenosis (ISR) undergoing stent implantation (ISR group). The de novo group had a significant increase in hsCRP levels post stenting, while the ISR group showed no increase in hsCRP post stenting. Intravascular ultrasound with radiofrequency data analysis showed that the de novo group had larger percentage of both necrotic core area and fibrofatty area at the target lesion than the ISR group, while the ISR group had a larger percentage of fibrous area. Differential inflammatory response to stent implantation between the de novo plaque and in ISR lesion is related to lesion morphology.

Markers of inflammation in men with small abdominal aortic aneurysm

BACKGROUND

Markers of inflammation and fibrin turnover are elevated in individuals with a large (>55 mm) abdominal aortic aneurysm (AAA). Fibrin degradation generates D-dimer, known to possess multiple proinflammatory effects, and levels are elevated during early AAA development. This study characterized the plasma inflammatory response during early AAA pathogenesis to determine the effect of D-dimer levels.

METHODS

The study compared 75 men with a small AAA (range, 30-54 mm) with 90 age-, sex-, and race-matched controls. Plasma interleukin-6 (IL-6), complement C3, high-sensitivity C-reactive protein (hsCRP), fibrinogen, and D-dimer levels were measured.

RESULTS

Mean levels of fibrinogen (2.92 vs 2.59 g/L; P = .003), hsCRP (2.07 vs 1.29 ng/mL; P = .005), and D-dimer (346.7 vs 120.2 ng/mL; P < .001) were higher in men with a small AAA. These markers correlated with maximum aortic diameter determined by ultrasound imaging. On multivariate analysis, D-dimer levels were elevated in AAA individuals independent of smoking, cardiovascular disease (CVD), atherosclerotic risk factors, and inflammatory parameters. Fibrinogen and hsCRP levels remained elevated after adjustment for these covariates but lost significance when D-dimer was added to the model.

CONCLUSION

C-reactive protein and D-dimer levels are elevated during early AAA development. D-dimer levels are most tightly associated with AAA status, however, and may mediate the observed elevation in acute-phase reactants.

Human gingiva is another site of C-reactive protein formation

OBJECTIVES

C-reactive protein (CRP) is primarily synthesized in the liver. It is hypothesized that human gingiva per se may produce CRP and its expression could be associated with IL-6. This study elucidated the CRP expression profile in human gingiva and its possible association with IL-6.

MATERIALS AND METHODS

Ninety-four gingival biopsies were collected from 44 subjects with chronic periodontitis and 18 periodontally healthy subjects. CRP protein was detected by immunohistochemistry and Western blotting, while CRP and IL-6 mRNAs were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time PCR. CRP protein expression in the reconstituted human gingival epithelia (RHGE) was examined by the particle-enhanced immunoturbidimetric assay and Western blotting.

RESULTS

CRP protein was detected in gingival tissues from patients and healthy subjects by immunohistochemistry and confirmed by Western blotting. Its expression pattern and level at 16 pairs of periodontal pocket tissues and the adjacent clinically healthy tissues from 16 patients were significantly interrelated (r(s)=0.693, p<0.01). CRP mRNA expression was strongly correlated with IL-6 (r=0.694, p<0.001). Both CRP protein and mRNA were detected in the RHGE.

CONCLUSIONS

The present study shows for the first time that human gingiva is able to produce CRP in situ that may be associated with IL-6 activity.

C-reactive protein gene variant and the human left ventricular growth response to exercise: data from The LARGE Heart Study

OBJECTIVE

Increased levels of C-reactive protein (CRP) are associated with left ventricular (LV) hypertrophy. This association may be causal (either directly or indirectly) or simply a confounder resulting from the recognized relationship between CRP and vascular disease. We attempted to clarify this issue, by assessing the association of a variant of the CRP gene with exercise-induced left ventricular hypertrophy in young healthy males: homozygosity for the T (rather than C) allele of the CRP +1444C>T gene variant is associated with serum CRP levels which are 0.68 mg/L higher than carriers of the C allele.

METHODS AND RESULTS

LV mass was measured using cardiovascular magnetic resonance in 301 army recruits before and after an identical 12-week physical training program. Subjects were genotyped for the CRP +1444C>T gene variant. LV mass was 164.25 +/-24.52 g at entry and increased with training (+3.77 +/- 10.77 g). This increase was greatest among those homozygous for the rare T allele (+8.17 6 12.09 vs. +3.37 6 10.58 for TT genotype vs. C-allele carriers respectively, P = 0.033).

CONCLUSIONS

CRP genotype is associated with a greater LV growth to exercise, supporting a causal association between CRP and LV growth. Whether such an association might be directly mediated or results from alterations in phenotypes which themselves drive LV growth (for instance, altered arterial compliance) is not clear.

Proinflammatory cytokines in CRP baseline regulation

Low-grade inflammation, a minor elevation in the baseline concentration of inflammatory markers such as C-reactive protein (CRP), is nowadays recognized as an important underlying condition in many common diseases. Concentrations of CRP under 10 mg/1 are called low-grade inflammation and values above that are considered as clinically significant inflammatory states. Epidemiological studies have revealed demographic and socioeconomic factors that associate with CRP concentration; these include age, sex, birth weight, ethnicity, socioeconomic status, body mass index (BMI), fiber consumption, alcohol intake, and dietary fatty acids. At the molecular level, production of CRP is induced by proinflammatory cytokines IL-1, IL-6, and IL-17 in the liver, although extra hepatic production most likely contributes to systemic concentrations. The cytokines are produced in response to, for example, steroid hormones, thrombin, C5a, bradykinin, other cytokines, UV-light, neuropeptides and bacterial components, such as lipopolysaccharide. Cytokines exert their biological effects on CRP by signaling through their receptors on hepatic cells and activating different kinases and phosphatases leading to translocation of various transcription factors on CRP gene promoter and production of CRP protein. Genetic polymorphisms in the interleukin genes as well as in CRP gene have been associated with minor elevation in CRP. As minor elevation in CRP is associated with both inflammatory and noninflammatory conditions, it should be noticed that the elevation might just reflect distressed or injured cells homeostasis maintenance in everyday life, rather than inflammation with classical symptoms of redness, swelling, heat, and pain.

Local C-reactive protein expression in obliterative lesions and the bronchial wall in posttransplant obliterative bronchiolitis

The local immunoreactivity of C-reactive protein (CRP) was studied in a heterotopic porcine model of posttranplant obliterative bronchiolitis (OB). Bronchial allografts and control autografts were examined serially 2–28 days after subcutaneous transplantation. The autografts stayed patent. In the allografts, proliferation of inflammatory cells (P < .0001) and fibroblasts (P = .02) resulted in occlusion of the bronchial lumens (P < .01). Influx of CD4+ (P < .001) and CD8+ (P < .0001) cells demonstrated allograft immune response. CRP positivity simultaneously increased in the bronchial walls (P < .01), in macrophages, myofibroblasts, and endothelial cells. Local CRP was predictive of features characteristic of OB (R = 0.456–0.879, P < .05−P < .0001). Early obliterative lesions also showed CRP positivity, but not mature, collagen-rich obliterative plugs (P < .05). During OB development, CRP is localized in inflammatory cells, myofibroblasts and endothelial cells probably as a part of the local inflammatory response.

C-reactive protein (CRP) induces chemokine secretion via CD11b/ICAM-1 interaction in human adherent monocytes

Several studies support C-reactive protein (CRP) as a systemic cardiovascular risk factor. The recent detection of CRP in arterial intima suggests a dual activity in atherosclerosis as a circulating and tissue mediator on vascular and immune cells. In the present paper, we focused on the inflammatory effects of CRP on human monocytes, which were isolated by Ficoll-Percoll gradients and cultured in adherence to polystyrene, endothelial cell monolayer, or in suspension. Chemokine levels, adhesion molecule, and chemokine receptor expression were detected by ELISA, flow cytometry, and real-time RT-PCR. Migration assays were performed in a Boyden chamber. Stimulation with CRP induced release of CCL2, CCL3, and CCL4 in adherent monocytes through the binding to CD32a, CD32b, and CD64, whereas no effect was observed in suspension culture. This was associated with CRP-induced up-regulation of adhesion molecules membrane-activated complex 1 (Mac-1) and ICAM-1 on adherent monocytes. Blockade of Mac-1/ICAM-1 interaction inhibited the CRP-induced chemokine secretion. In addition, CRP reduced mRNA and surface expression of corresponding chemokine receptors CCR1, CCR2, and CCR5 in adherent monocytes. This effect was a result of chemokine secretion, as coincubation with neutralizing anti-CCL2, anti-CCL3, and anti-CCL4 antibodies reversed the effect of CRP. Accordingly, a reduced migration of CRP-treated monocytes to CCL2 and CCL3 was observed. In conclusion, our data suggest an in vitro model to study CRP activities in adherent and suspension human monocytes. CRP-mediated induction of adhesion molecules and a decrease of chemokine receptors on adherent monocytes might contribute to the retention of monocytes within atherosclerotic lesions and recruitment of other circulating cells.

Supplementation with orange and blackcurrant juice, but not vitamin E, improves inflammatory markers in patients with peripheral arterial disease

Inflammation and endothelial activation are associated with an increased risk of CVD and epidemiological evidence suggests an association between levels of markers of inflammation or endothelial activation and the intake of fruit. Also, vitamin E, a fat-soluble antioxidant, has anti-inflammatory properties. We performed a randomised 2 × 2 factorial, crossover trial to determine the effect of orange and blackcurrant juice (500 ml/d) and vitamin E (15 mg RRR-α-tocopherol/d) supplementation on markers of inflammation and endothelial activation in forty-eight patients with peripheral arterial disease. Patients were randomly allocated to two dietary supplements from the four possible combinations of juice and vitamin E: juice+vitamin E; juice+placebo; reference beverage (sugar drink)+vitamin E; and reference beverage+placebo. The supplementations were given for 28 d, separated by a 4-week wash-out period. Analysis of main effects showed that juice decreased C-reactive protein (CRP) by 11 % and fibrinogen by 3 % while the reference drink increased CRP by 13 % and fibrinogen by 2 % (P < 0·008 and P < 0·002, respectively). No significant differences were measured for IL-6 and the endothelial activation markers von Willebrand factor, tissue-plasminogen activator and plasmin activator inhibitor-1. Vitamin E supplementation had no significant effects on the various markers. We observed no significant interaction between juice and vitamin E. In this study, orange and blackcurrant juice reduced markers of inflammation, but not markers of endothelial activation, in patients with peripheral arterial disease, relative to sugar drinks.

Angiotensin II-induced C-reactive protein generation: Inflammatory role of vascular smooth muscle cells in atherosclerosis

BACKGROUND

As the major target of Angiotensin II (Ang II) in the vessel wall, vascular smooth muscle cells (VSMCs) are a tentative source to produce C-reactive protein (CRP). However, it is largely unknown if Ang II is capable of inducing CRP production in VSMCs.

METHODS AND RESULTS

Ang II induced a concentration-dependent release of CRP in cultured rat VSMCs as measured by sandwich ELISA. Real-time PCR revealed that Ang II significantly upregulated CRP mRNA level in vitro. Ang II-induced CRP generation in aortic VSMCs was also investigated using double-labeled fluorescent immunohistochemistry and in situ hybridization in subchronic Ang II administration in rats. Losartan but not PD123319 markedly blocked the Ang II-induced CRP production in cultured VSMCs, suggesting that such effect was mediated via Ang II type 1 receptor. Further, Western blotting analysis showed that mitogen-activated protein kinase (MAPK) activation was obligatory in Ang II-induced CRP production, since specific MAPK inhibitor PD098059 almost abolished the action.

CONCLUSIONS

We identified that Ang II is capable of inducing CRP generation in VSMCs, in which Ang II type 1 receptor followed by MAPK signal pathway is involved. It strengthened the role of Ang II-induced CRP production by VSMCs in the inflammatory process in atherosclerosis.

Antibodies against heat shock protein 60 derived from Helicobacter pylori: diagnostic implications in cardiovascular disease

Immune responses against heat shock protein 60 (HSP60) of pathogen-origin are thought to be defensive events which, due to molecular mimicry, misdirect to a human counterpart. Therefore, atherosclerosis may be serologically predicted by anti-HSP60 antibodies (Abs). In the present study, we analyzed the clinical prevalence of the serum IgG Abs against Helicobacter pylori (Hp)-derived HSP60 (Hp-HSP60) or its peptide fragments in patients with cardiovascular disease (CVD; n=250), as compared to those in age- and gender-matched non-CVD patients (n=293). Anti-Hp cell lysate Abs frequently appeared in Hp-infected patients who were not associated with CVD. In contrast, Abs against the particular amino acid sequence Hp-HSP60(II3) (II3 region, Glu(141)-Leu(160), in Hp-HSP60) predominantly appeared in CVD patients, as well as IgG anti-human HSP60 (Hu-HSP60(w)). Furthermore, neither titer of anti-Hp-HSP60(II3) nor anti-Hu-HSP60(w) Abs was correlated with the levels of high sensitivity C-reactive protein (hsCRP). This data strongly suggested that IgG anti-Hp-HSP60(II3) Abs cross-reacted with Hu-HSP60(w) were independent diagnostic markers relevant to CVD. Further, the 20 amino acid residues (Glu(141)-Leu(160)) might be predominant CVD-associated epitopes that induce anti-Hu-HSP60 auto-Abs, whose location was predicted in the tertiary structure of Hu-HSP60.