C-Reactive Protein Increases Oxygen Radical Generation by Neutrophils

Investigation of the inhibition of bacteria and endotoxin influx by back filtration through dialyzer membranes

We investigated the usefulness of assays using human neutrophils for radical production as well as endotoxin (ET) measurement and bacterial culture for endotoxin and bacterial influx by back filtration using dialyzers with different membrane pore diameters. Three types of dialyzers made of cellulose triacetate membrane material with different pore size FB-110EG eco, FB-110U eco, and FB-150UHβ eco were used. A circuit to generate back filtration was created. Back filtrate generated by hydraulic head pressure operation was collected. ET and bacteria were examined. Human neutrophils were exposed to back filtrate (experiments using three different membranes) and contaminated solution, and free radical production was measured using LBP-953 (Berthold) to see if there were differences in production. No bacteria were detected and the concentration of endotoxin was below the detection limit in the back filtrate from the three types of membranes and purified water. Free radical production from neutrophils in the contaminated water was highest at 4,405,750 ± 61,244 cpm (counts per minute) (mean ± SD) (P < 0.01 vs FB-150UHβ eco, FB-110U-eco, and FB-110EG eco) followed by that in back filtrate via FB-150UHβ eco, FB-110U-eco, FB-110EG eco. Radical production from neutrophils was thereby higher in the back filtrate of dialyzers with larger pore-size membranes. No bacteria were observed and the concentration of ET was below the detection limit in back filtrate from any of the membranes. However, when the reverse filtrate was exposed to neutrophils, radical production increased along with pore size, suggesting the influx of small pyrogens and other pyrogenic substances.

Association between Combination Antiretroviral Therapy and Telomere Length in People Living with Human Immunodeficiency Virus

Long-term exposure to combination antiretroviral therapy (cART) may be associated with accelerated ageing. Telomere length is considered to be reliable aging biomarker. The aim of this study was to compare patients' relative telomere length (RTL) between and within different cART classes and to estimate the impact of certain HIV-related variables on RTL. The study was conducted in 176 HIV-infected male patients receiving cART, with ≤50 copies HIV RNA/mL plasma. RTL was determined from mononuclear cells by quantitative polymerase chain reaction. Standard statistical tests and unsupervised machine learning were performed. The mean RTL was 2.50 ± 1.87. There was no difference (p = 0.761) in RTL between therapeutic groups: two nucleoside reverse transcriptase inhibitors as the backbone treatment, combined with either integrase inhibitor, protease inhibitor, or non-nucleoside reverse transcriptase inhibitor (NNRTI). Machine learning results suggested duration of HIV infection, CD4+ T-cell count, and cART, including NNRTI, as potentially significant variables impacting RTL. Kendall's correlation test excluded duration of HIV infection (p = 0.220) and CD4+ T-cell count (p = 0.536) as significant. The Mann-Whitney test confirmed that cART containing NNRTI impacted RTL (p = 0.018). This was the first study to show that patients using efavirenz within cART had significantly shorter telomeres than patients using nevirapine.

Caffeine and Its Antioxidant Properties-It Is All about Dose and Source

Caffeine is the most frequently used substance with a central nervous system stimulant effect, but its consumption is most often due to the intake of foods and drinks that contain it (coffee, tea, chocolate, food supplements with plant extracts of Guarana, Mate herba, Cola nuts). Due to its innocuity, caffeine is a safe xanthine alkaloid for human consumption in a wide range of doses, being used for its central nervous stimulating effect, lipolytic and diuresis-enhancing properties, but also as a permitted ergogenic compound in athletes. In addition to the mechanisms that explain the effects of caffeine on the targeted organ, there are many proposed mechanisms by which this substance would have antioxidant effects. As such, its consumption prevents the occurrence/progression of certain neurodegenerative diseases as well as other medical conditions associated with increased levels of reactive oxygen or nitrogen species. However, most studies that have assessed the beneficial effects of caffeine have used pure caffeine. The question, therefore, arises whether the daily intake of caffeine from food or drink has similar benefits, considering that in foods or drinks with a high caffeine content, there are other substances that could interfere with this action, either by potentiating or decreasing its antioxidant capacity. Natural sources of caffeine often combine plant polyphenols (phenol-carboxylic acids, catechins) with known antioxidant effects; however, stimulant drinks and dietary supplements often contain sugars or artificial sweeteners that can significantly reduce the effects of caffeine on oxidative stress. The objective of this review is to clarify the effects of caffeine in modulating oxidative stress and assess these benefits, considering the source and the dose administered.

Does AGE-RAGE Stress Play a Role in the Development of Coronary Artery Disease in Obesity?

This article deals with the role of AGE (advanced glycation end products)-RAGE (receptor for AGE) stress (AGE/sRAGE) in the development of coronary artery disease (CAD) in obesity. CAD is due to atherosclerosis in coronary artery. The serum/plasma levels of AGE and sRAGE are reduced, while AGE-RAGE stress and expression of RAGE are elevated in obese individuals. However, the levels of AGE are elevated in obese individuals with more than one metabolic syndrome. The increases in the AGE-RAGE stress would elevate the expression and production of atherogenic factors, including reactive oxygen species, nuclear factor-kappa B, cytokines, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, endothelial leukocyte adhesion molecules, monocyte chemoattractant protein-1, granulocyte-macrophage colony-stimulating factor, and growth factors. Low levels of sRAGE would also increase the atherogenic factors. The increases in the AGE-RAGE stress and decreases in the levels of sRAGE would induce development of atherosclerosis, leading to CAD. The therapeutic regimen for AGE-RAGE stress-induced CAD in obesity would include lowering of AGE intake, prevention of AGE formation, degradation of AGE in vivo, suppression of RAGE expression, blockade of AGE-RAGE interaction, downregulation of sRAGE expression, and use of antioxidants. In conclusion, the data suggest that AGE-RAGE stress is involved in the development of CAD in obesity, and the therapeutic interventions to reduce AGE-RAGE would be helpful in preventing, regressing, and slowing the progression of CAD in obesity.

Current Status of Primary, Secondary, and Tertiary Prevention of Coronary Artery Disease

Fifty percent of all death from cardiovascular diseases is due to coronary artery disease (CAD). This is avoidable if early identification is made. Preventive health care has a major role in the fight against CAD. Atherosclerosis and atherosclerotic plaque rupture are involved in the development of CAD. Modifiable risk factors for CAD are dyslipidemia, diabetes, hypertension, cigarette smoking, obesity, chronic renal disease, chronic infection, high C-reactive protein, and hyperhomocysteinemia. CAD can be prevented by modification of risk factors. This paper defines the primary, secondary, and tertiary prevention of CAD. It discusses the mechanism of risk factor-induced atherosclerosis. This paper describes the CAD risk score and its use in the selection of individuals for primary prevention of CAD. Guidelines for primary, secondary, and tertiary prevention of CAD have been described. Modification of risk factors and use of guidelines for prevention of CAD would prevent, regress, and slow down the progression of CAD, improve the quality of life of patient, and reduce the health care cost.

NETosis as a Pathogenic Factor for Heart Failure

Heart failure threatens the lives of patients and reduces their quality of life. Heart failure, especially heart failure with preserved ejection fraction, is closely related to systemic and local cardiac persistent chronic low-grade aseptic inflammation, microvascular damage characterized by endothelial dysfunction, oxidative stress, myocardial remodeling, and fibrosis. However, the initiation and development of persistent chronic low-grade aseptic inflammation is unexplored. Oxidative stress-mediated neutrophil extracellular traps (NETs) are the main immune defense mechanism against external bacterial infections. Furthermore, NETs play important roles in noninfectious diseases. After the onset of myocardial infarction, atrial fibrillation, or myocarditis, neutrophils infiltrate the damaged tissue and aggravate inflammation. In tissue injury, damage-related molecular patterns (DAMPs) may induce pattern recognition receptors (PRRs) to cause NETs, but whether NETs are directly involved in the pathogenesis and development of heart failure and the mechanism is still unclear. In this review, we analyzed the markers of heart failure and heart failure-related diseases and comorbidities, such as mitochondrial DNA, high mobility box group box 1, fibronectin extra domain A, and galectin-3, to explore their role in inducing NETs and to investigate the mechanism of PRRs, such as Toll-like receptors, receptor for advanced glycation end products, cGAS-STING, and C-X-C motif chemokine receptor 2, in activating NETosis. Furthermore, we discussed oxidative stress, especially the possibility that imbalance of thiol redox and MPO-derived HOCl promotes the production of 2-chlorofatty acid and induces NETosis, and analyzed the possibility of NETs triggering coronary microvascular thrombosis. In some heart diseases, the deletion or blocking of neutrophil-specific myeloperoxidase and peptidylarginine deiminase 4 has shown effectiveness. According to the results of current pharmacological studies, MPO and PAD4 inhibitors are effective at least for myocardial infarction, atherosclerosis, and certain autoimmune diseases, whose deterioration can lead to heart failure. This is essential for understanding NETosis as a therapeutic factor of heart failure and the related new pathophysiology and therapeutics of heart failure.

AGE-RAGE Stress and Coronary Artery Disease

Coronary artery atherosclerosis and atherosclerotic plaque rupture cause coronary artery disease (CAD). Advanced glycation end products (AGE) and its cell receptor RAGE, and soluble receptor (sRAGE) and endogenous secretory RAGE (esRAGE) may be involved in the development of atherosclerosis. AGE and its interaction with RAGE are atherogenic, while sRAGE and esRAGE have antiatherogenic effects. AGE-RAGE stress is a ratio of AGE/sRAGE. A high AGE-RAGE stress results in development and progression of CAD and vice-versa. AGE levels in serum and skin, AGE/sRAGE in patients with CAD, and expression of RAGE in animal model of atherosclerosis were higher, while serum levels of esRAGE were lower in patients with CAD compared with controls. Serum levels of sRAGE in CAD patients were contradictory, increased or decreased. This contradictory data may be due to type of patients used, because the sRAGE levels are elevated in diabetics and end-stage renal disease. AGE/sRAGE ratio is elevated in patients with reduced or elevated levels of serum sRAGE. It is to stress that AGE, RAGE, sRAGE, or esRAGE individually cannot serve as universal biomarker. AGE and sRAGE should be measured simultaneously to assess the AGE-RAGE stress. The treatment of CAD should be targeted at reduction in AGE levels, prevention of AGE formation, degradation of AGE in vivo, suppression of RAGE expression, blockade of RAGE, elevation of sRAGE, and use of antioxidants. In conclusion, AGE-RAGE stress would initiate the development and progression of atherosclerosis. Treatment modalities would prevent, regress, and slow the progression of CAD.

Serum anti-inflammatory and inflammatory markers have no causal impact on telomere length: a Mendelian randomization study

INTRODUCTION

The relationship between inflammatory and anti-inflammatory markers and telomere length (TL), a biological index of aging, is still poorly understood. By applying a 2-sample Mendelian randomization (MR), we investigated the causal associations between adiponectin, bilirubin, C-reactive protein (CRP), leptin, and serum uric acid (SUA) with TL.

MATERIAL AND METHODS

MR was implemented by using summary-level data from the largest ever genome-wide association studies (GWAS) conducted on our interested exposure and TL. Inverse variance weighted method (IVW), weighted median (WM)-based method, MR-Egger, MR-Robust Adjusted Profile Score (RAPS), and MR-Pleiotropy RESidual Sum and Outlier (PRESSO) were applied. Sensitivity analysis was conducted using the leave-one-out method.

RESULTS

With regard to adiponectin, CRP, leptin, and SUA levels, we found no effect on TL for all 4 types of tests (all p > 0.108). Results of the MR-Egger (p = 0.892) and IVW (p = 0.124) showed that bilirubin had no effect on telomere maintenance, whereas the results of the WM (p = 0.030) and RAPS (p = 0.022) were negative, with higher bilirubin concentrations linked to shorter TL. There was a low likelihood of heterogeneity for all the estimations, except for bilirubin (IVW p = 0.026, MR Egger p = 0.018). MR-PRESSO highlighted no outlier. For all the estimations, we observed negligible intercepts that were indicative of low likelihood of the pleiotropy (all p > 0.161). The results of leave-one-out method demonstrated that the links are not driven because of single nucleotide polymorphisms (SNPs).

CONCLUSIONS

Our results highlight that neither the anti-inflammatory nor pro-inflammatory markers tested have any significant causal effect on TL. The casual role of bilirubin on TL still needs to be investigated.

Active surveillance in prostate cancer management: where do we stand now?

Prostate cancer (PCa) is the most common cancer in men, with a steadily rising incidence, affecting on average one in six men during their lifetime. The increase in morbidity is related to the increasing overall life expectancy, prostate-specific antigen testing, implementation of new molecular markers for cancer detection and the more frequent application of multiparametric magnetic resonance imaging. There is growing evidence demonstrating that active surveillance (AS) is an alternative to immediate intervention in patients with very low- and low-risk prostate cancer. Ongoing reports from multiple studies have consistently demonstrated a very low rate of metastases and prostate cancer specific mortality in selected cohorts of patients. As a matter of fact, AS has been adopted by many institutions as a safe and effective management strategy. The aim of our review is to summarize the contemporary data on AS in patients affected with PCa with the intention to present the most clinically useful and pertinent AS protocols.

Effect of metabolic syndrome on incidence of oral potentially malignant disorder: a prospective cohort study in Taiwan

OBJECTIVES

We aimed to assess the effect of metabolic syndrome (MetS) on incident oral potentially malignant disorder (OPMD).

DESIGN

We conducted a prospective cohort study of the Changhua community-based integrated screening (CHCIS) programme and nationwide oral cancer screening programme during the period between 2005 and 2014.

SETTING

CHCIS, Taiwan.

PARTICIPANTS

We enrolled 17 590 participants aged 30 years and older.

MAIN OUTCOMES AND MEASURES

We assessed the impact of MetS on the outcome measured by incident OPMD.

RESULTS

The incidences of OPMD among subjects with and without MetS were 7.68 ‰ and 5.38 ‰, respectively. After adjusting for confounders, subjects with MetS exhibited a statistically greater risk of developing OPMD compared with those who were free of MetS by 33% (adjusted rate ratio, aRR=1.33, 95% CI 1.14 to 1.55). Individual components of MetS still remained significant, including central obesity (aRR=1.22, 95% CI 1.04 to 1.44), hypertriglyceridaemia (aRR=1.26, 95% CI 1.07 to 1.49) and hyperglycaemia (aRR=1.20, 95% CI 1.02 to 1.41). Central obesity and hypertriglyceridaemia were also statistically associated with a subtype of OPMD, namely, leukoplakia.

CONCLUSION

The temporal influence of MetS on the risk of incident OPMD was noted in our prospective cohort study. Therefore, promoting an MetS prevention and control programme might reduce the occurrence of OPMD and oral cancer.

Association of chronic fatigue syndrome with premature telomere attrition

Background

Chronic fatigue syndrome (CFS), also known as myalgic encephalomyelitis (ME), is a severely debilitating condition of unknown etiology. The symptoms and risk factors of ME/CFS share features of accelerated aging implicated in several diseases. Using telomere length as a marker, this study was performed to test the hypothesis that ME/CFS is associated with accelerated aging.

Methods

Participant (n = 639) data came from the follow-up time point of the Georgia CFS surveillance study. Using the 1994 CFS Research Case Definition with questionnaire-based subscale thresholds for fatigue, function, and symptoms, participants were classified into four illness groups: CFS if all criteria were met (n = 64), CFS-X if CFS with exclusionary conditions (n = 77), ISF (insufficient symptoms/fatigue) if only some criteria were met regardless of exclusionary conditions (n = 302), and NF (non-fatigued) if no criteria and no exclusionary conditions (n = 196). Relative telomere length (T/S ratio) was measured using DNA from whole blood and real-time PCR. General linear models were used to estimate the association of illness groups or T/S ratio with demographics, biological measures and covariates with significance set at p < 0.05.

Results

The mean T/S ratio differed significantly by illness group (p = 0.0017); the T/S ratios in CFS (0.90 ± 0.03) and ISF (0.94 ± 0.02) were each significantly lower than in NF (1.06 ± 0.04). Differences in T/S ratio by illness groups remained significant after adjustment for covariates of age, sex, body mass index, waist–hip ratio, post-exertional malaise and education attainment. Telomere length was shorter by 635, 254 and 424 base pairs in CFS, CFS-X and ISF, respectively, compared to NF. This shorter telomere length translates to roughly 10.1–20.5, 4.0–8.2 and 6.6–13.7 years of additional aging in CFS, CFS-X and ISF compared to NF respectively. Further, stratified analyses based on age and sex demonstrated that the association of ME/CFS with short telomeres is largely moderated by female subjects < 45 years old.

Conclusions

This study found a significant association of ME/CFS with premature telomere attrition that is largely moderated by female subjects < 45 years old. Our results indicate that ME/CFS could be included in the list of conditions associated with accelerated aging. Further work is needed to evaluate the functional significance of accelerated aging in ME/CFS.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1414-x) contains supplementary material, which is available to authorized users.

The Telomeric Complex and Metabolic Disease

The attrition of telomeres is believed to be a key event not only in mammalian aging, but also in disturbed nutrient sensing, which could lead to numerous metabolic dysfunctions. The current debate focuses mainly on the question whether telomere shortening, e.g., as a heritable trait, may act as a cause or rather represents a consequence of such chronic diseases. This review discusses the damaging events that ultimately may lead or contribute to telomere shortening and can be associated with metabolic diseases.

Telomere Length Is Associated With Cardiometabolic Factors in US Adults

Telomere length (TL) has been associated with age-related health outcomes. We investigated the relationship of TL with cardiometabolic risk profile in adult Americans. We used the National Health and Nutrition Examination Surveys for 1999 to 2002, accounting for complex sampling and survey design. Of the 8892 eligible participants, 47.8% (n = 4123) were men. Mean serum high-density lipoprotein cholesterol concentrations significantly increased across increasing TL quarters ( P = .013), and mean fat mass, fat-free mass, hemoglobin A_1c (HbA_1c), and C-reactive protein significantly decreased across increasing TL quarters (all P < .001) in men. Only HbA_1c levels significantly decreased across increasing TL quarters ( P = .041) in women. Males in the upper quarter of TL had lower (38%) odds of prevalent metabolic syndrome compared with those in the lower quarter ( P < .001). These results support the hypotheses that cardiometabolic factors are related to TL, especially in men.

Association between the dietary inflammatory index (DII) and telomere length and C-reactive protein from the National Health and Nutrition Examination Survey-1999-2002

SCOPE

Leukocyte telomere length (LTL) is an important biomarker of aging. This study examined whether inflammatory potential of diet, as measured by the Dietary Inflammatory Index^TM (DII) has an impact on telomere shortening in the National Health and Nutrition Examination Survey (NHANES). We also carried out validation of the DII with C-reactive protein (CRP).

METHODS AND RESULTS

Data came from NHANES 1999-2002. LTL and CRP were assayed from leukocyte DNA and serum specimens, respectively. The DII was calculated from food intakes assessed using 24-h dietary recalls and expressed per 1000 calories consumed. Associations were examined using survey-based multivariable linear regression for log-transformed LTL. After multivariable adjustment, higher DII scores (i.e. relatively more pro inflammatory) were associated with shorter LTL both when used as continuous (b  =  -0.003; 95% confidence interval [CI]  =  -0.005, -0.0002) and as quartiles (b_{DIIquartile4vs1}   =  -0.013; 95% CI  =  -0.025, -0.001; P_trend   =  .03). In this same sample the DII also was associated with CRP ≥3 mg/L (OR_{DIIcontinuous} = 1.10; 95% CI = 1.06, 1.16).

CONCLUSION

In these NHANES data there was an association between DII and LTL. This study also provided a successful construct validation of the DII using CRP in a nationally representative sample. These results are consistent with the hypothesis that diet-associated inflammation determines LTL.

Psychological Profiles in the Prediction of Leukocyte Telomere Length in Healthy Individuals

BACKGROUND

Shorter telomere length (TL) may signal premature cellular aging and increased risk for disease. While depression and psychosocial stress have been associated with shorter telomeres, other psychological risk factors for cardiovascular disease have received less attention.

PURPOSE

To evaluate the association between TL and psychological risk factors (symptoms of anxiety and depression, hostility and defensiveness traits) for heart disease, and to examine whether chronological age and sex moderate the associations observed.

METHODS

132 healthy men and women (Mage = 45.34 years) completed the Marlowe-Crowne Social Desirability Scale, the Beck Depression Inventory II, The Beck Anxiety Inventory and the Cook-Medley Hostility Scale. Relative TL was measured by quantitative polymerase chain reaction (PCR) of total genomic DNA samples. A series of hierarchical linear regressions were performed controlling for pertinent covariates.

RESULTS

Shorter TL was observed among individuals high in defensiveness (β = -.221) and depressive symptoms (β = -.213), as well as in those with less hostility (β =.256) and anxiety (β =.220)(all Ps<.05). Psychological variables explained 19% of the variance over and above that explained by covariates (age, sex, exercise, alcohol consumption, systemic inflammation, and 24-hr mean arterial pressure). Age moderated the relation between TL and defensiveness (β =.179, p =.03). Sex did not influence any of the relations.

CONCLUSIONS

Telomere length is associated with psychological burden though the direction of effect differs depending on the psychological variables under study. Further research is needed to determine the reasons for and implications of these seemingly contradictory findings.

Plant-Based Nutraceutical Increases Plasma Catalase Activity in Healthy Participants: A Small Double-Blind, Randomized, Placebo-Controlled, Proof of Concept Trial

Oxidative stress resulting from dietary, lifestyle and environmental factors is strongly associated with tissue damage and aging. It occurs when there is either an overproduction of reactive oxygen species (i.e., oxidants) or decreased bioavailability of antioxidants that can scavenge them. The objective of this 12-week double-blind placebo-controlled study was to assess the efficacy of a nutraceutical at augmenting antioxidant status. Healthy adults (25-45 y) were randomized to either a treatment group (Product B, n = 23) or a placebo group (control, n = 20). No significant effect of Product B was observed for anthropometric variables or markers of glucose and lipid regulation. Biomarkers of oxidative stress were likewise not altered following the 12-week intervention. Plasma catalase concentrations were significantly elevated following 12 weeks of Product B as compared to the control group (+6.1 vs. -10.3 nmol/min/mL, p = 0.038), whereas other measures of antioxidant capacity were not significantly different between the groups. Product B effectively augmented concentrations of the anti-aging antioxidant catalase in healthy adults.

Oxidative Stress in Renal Transplant Patients Who Develop Cardiovascular Disease

Cardiovascular disease limits life expectancy of successful renal transplant patients. Reactive oxygen species have been implicated in the development of atherosclerosis, and high levels could be due to increased production or a decrease in antioxidant reserve. Cardiovascular disease in renal transplant recipients could be due to elevated levels of malondialdehyde (an index of levels of reactive oxygen species) and homocysteine and reduced levels of glutathione. Renal transplant recipients with and without cardiovascular disease were studied along with healthy controls. Serum malondialdehyde, plasma homocysteine, and red blood cell glutathione were measured. The results suggest that levels of serum malondialdehyde and plasma homocysteine were higher in patients with or without cardiovascular disease compared with controls; however, the values were similar in both groups of transplant patients. Glutathione levels in red blood cells were similar in all 3 groups. Renal transplant recipients without cardiovascular disease have high levels of oxidative stress and may develop cardiovascular disease with time.

Neutrophil's weapons in atherosclerosis

Neutrophils are important components of immunity associated with inflammatory responses against a broad spectrum of pathogens. These cells could be rapidly activated by proinflammatory stimuli and migrate to the inflamed and infected sites where they release a variety of cytotoxic molecules with antimicrobial activity. Neutrophil antibacterial factors include extracellular proteases, redox enzymes, antimicrobial peptides, and small bioactive molecules. In resting neutrophils, these factors are stored in granules and released upon activation during degranulation. These factors could be also secreted in a neutrophil-derived microparticle-dependent fashion. Neutrophils exhibit a unique property to produce neutrophil extracellular traps (NETs) composed of decondensed chromatin and granular proteins to catch and kill bacteria. Neutrophil-released factors are efficient in inactivation and elimination of pathogens through oxidation-dependent or independent damage of bacterial cells, inactivation and neutralization of virulence factors and other mechanisms. However, in chronic atherosclerosis-associated inflammation, protective function of neutrophils could be impaired and misdirected against own cells. This could lead to deleterious effects and progressive vascular injury. In atherogenesis, a pathogenic role of neutrophils could be especially seen in early stages associated with endothelial dysfunction and induction of vascular inflammation and in late atherosclerosis associated with plaque rupture and atherothrombosis. Assuming a prominent impact of neutrophils in cardiovascular pathology, developing therapeutic strategies targeting neutrophil-specific antigens could have a promising clinical potential.

Inhibition of inflammation may enhance nitric oxide availability in patients undergoing bariatric surgery for weight loss

BACKGROUND

Weight loss surgery is the most effective treatment for morbid obesity. The mechanisms underlying the beneficial cardiovascular effects are poorly understood, although inhibition of inflammatory markers has been demonstrated. We hypothesized that anti-inflammatory and antioxidative stress reactions are responsible for the beneficial effects of bariatric surgery that have been shown in clinical trials.

METHODS

The inflammatory system was studied by measuring mRNA levels of E-selectin, tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and in a cell line (HUVEC-CS) of human umbilical vein endothelial cells that were incubated for 4 h with pools of serum, collected before and 3 months after surgery, from 20 women who underwent bariatric surgery for weight loss. The oxidative stress pathway was examined by mRNA expression of NADPH oxidase (P22(phox) ), paraoxonase (PON2), superoxide dismutase 2 (SOD2), glutathione peroxidase (GPx) and catalase following incubation of the cells for 4 h with serum pools. The nitric oxide (NO) pathway was studied by measuring mRNA levels of inducible NOS and endothelial NOS and by determining nitrite and nitrate levels. To study the functional behaviour of endothelial cells under stress, primary human umbilical vein endothelial cells (PECs) were incubated with the serum pools for 48 h, with lipopolysaccharide (LPS) for the last 4 h.

RESULTS

The inflammatory system: incubation of HUVEC-CS cells with serum from women who underwent bariatric surgery led to a significant decrease in mRNA expression of E-selectin and IL-6 postsurgery. Stimulation of PECs with LPS in the presence of serum from women who underwent bariatric surgery caused a more significant difference in E-selectin and TNF-α mRNA expression before and after surgery. The antioxidant system: incubation of HUVEC-CS cells with serum from women who underwent bariatric surgery did not lead to any difference in mRNA expression of P22(phox) , PON2, SOD2, GPx or catalase. Stimulation of PECs with LPS showed that obese women had higher levels of P22(phox) , PON2 and the antioxidant enzymes SOD2, GPx and catalase before and after surgery, compared to the control group. The NO pathway: HUVEC-CS cells incubated with serum from women who underwent bariatric surgery secreted higher nitrite/nitrate levels compared to presurgery serum (P = 0.04).

CONCLUSIONS

Inhibition of inflammation and enhanced availability of NO 3 months after bariatric surgery could partly explain the beneficial effects of surgery for weight loss.

Pathophysiology and Medical Treatment of Carotid Artery Stenosis

Stroke is the third leading cause of mortality. Approximately 80 to 85% strokes are ischemic due to carotid artery stenosis (CAS). The prevalence of significant CAS is 7% in women and 9% in men. Severe asymptomatic CAS varies from 0 to 3.1%. Prevalence of symptomatic CAS is high in patients with peripheral arterial disease. CAS is due to atherosclerosis, the major risk factors for which include dyslipidemia, hypertension, diabetes, obesity, cigarette smoking, advanced glycation end products (AGEs) and its receptors (RAGE, soluble RAGE [sRAGE]), lack of exercise and C-reactive protein (CRP). This article discusses the basic mechanism of atherosclerosis and the mechanisms by which these risk factors induce atherosclerosis. The role of AGEs and its receptors in the development and progression of CAS has been discussed in detail. Lifestyle changes and medical treatment of CAS such as lifestyle changes, lipid-lowering agents, antihypertensive agents, antidiabetic drugs, anti-AGE therapy, measures to elevate soluble receptors of AGE (sRAGE, esRAGE). CRP-lowering agents have been discussed in detail. The drugs especially lipid-lowering agents, and antihypertensive and antidiabetic drugs suppress, regress, and slow the progression of CAS. The possible role of lowering the levels of AGEs and raising the levels of sRAGE in the treatment of CAS has been proposed. Lifestyle changes besides medical treatment have been stressed. Lifestyle changes and medical treatment not only would slow the progression of CAS but would also regress the CAS.

Oxidative stress as a mechanism of added sugar-induced cardiovascular disease

Added sugars comprising of table sugar, brown sugar, corn syrup, maple syrup, honey, molasses, and other sweeteners in the prepared processed foods and beverages have been implicated in the pathophysiology of cardiovascular diseases. This article deals with the reactive oxygen species (ROS) as a mechanism of sugar-induced cardiovascular diseases. There is an association between the consumption of high levels of serum glucose with cardiovascular diseases. Various sources of sugar-induced generation of ROS, including mitochondria, nicotinamide adenine dinucleotide phosphate-oxidase, advanced glycation end products, insulin, and uric acid have been discussed. The mechanism by which ROS induce the development of atherosclerosis, hypertension, peripheral vascular disease, coronary artery disease, cardiomyopathy, heart failure, and cardiac arrhythmias have been discussed in detail. In conclusion, the data suggest that added sugars induce atherosclerosis, hypertension, peripheral vascular disease, coronary artery disease, cardiomyopathy, heart failure, and cardiac arrhythmias and that these effects of added sugars are mediated through ROS.

Increased body mass index, elevated C-reactive protein, and short telomere length

CONTEXT

Obesity is associated with short telomere length. The cause of this association is unknown.

OBJECTIVE

We hypothesized that genetically increased body mass index (BMI) is associated with telomere length shortening and that low-grade inflammation might contribute through elevated C-reactive protein.

SETTING AND DESIGN

We studied 45,069 individuals from the Copenhagen General Population Study with measurements of leukocyte telomere length, BMI, and C-reactive protein in a Mendelian randomization study. Using the three obesity-associated polymorphisms FTO rs9939609, MC4R rs17782313, and TMEM18 rs6548238, and the CRP promoter polymorphism rs3091244 in instrumental variable analyses, we estimated the associations between genetically increased BMI and telomere length and between genetically increased C-reactive protein and telomere length.

RESULTS

In multivariable-adjusted observational analyses, telomere length decreased with seven base pairs (95% confidence interval, -9--5) per unit increase in BMI, and further adjustment for C-reactive protein attenuated this association to -5 base pairs (-8--3). In accordance, instrumental variable analysis showed a non-significant telomere length shortening of six base pairs (-37-25) per unit increase in genetically determined BMI. Furthermore, in observational analyses, telomere length decreased with nine base pairs (-16--2) for a doubling in C-reactive protein, supported by the instrumental variable analyses showing a corresponding genetically determined decrease of 66 base pairs (-124--7).

CONCLUSIONS

High BMI is associated with short telomere length observationally. This might possibly be mediated through elevated C-reactive protein, given that genetically elevated C-reactive protein levels are associated with short telomere length.

Association of biomarkers of inflammation and oxidative stress with the risk of chronic kidney disease in Type 2 diabetes mellitus in North Indian population

Chronic kidney disease (CKD) is a major cause of morbidity and mortality worldwide. It results from diverse etiologies, diabetes being a frontrunner amongst them. Type 2 diabetes mellitus (DM) is being increasingly recognized as a proinflammatory state with increased oxidative stress which enormously increases the risk of micro and macro vascular diseases. This study was planned to explore the possible association between tumor necrosis factor-alpha (TNF-α), urinary monocyte chemoattractant protein-1 (uMCP-1), high-sensitivity C-reactive protein (hsCRP) and parameters of oxidative stress in patients with Type 2 diabetes mellitus (DM) and diabetic chronic kidney disease (DM-CKD). Fifty patients each were recruited in DM, DM-CKD and healthy control groups. Plasma TNF-α, hsCRP and uMCP-1 levels as inflammatory mediators were measured by ELISA, reduced glutathione (GSH), ferric reducing ability of plasma (FRAP) as parameters of antioxidant activity and malondialdehyde (MDA) as marker of oxidative stress, were measured spectrophotometrically. Plasma TNF-α, hsCRP and uMCP-1 were significantly higher in DM-CKD compared to DM and healthy controls. Lipid peroxidation, measured as MDA was significantly higher in patients with DM-CKD as compared to patients with DM and healthy controls. Further, antioxidant capacity of blood measured as FRAP and GSH was found to be significantly lower in patients with DM and DM-CKD as compared to healthy controls (p<0.001). Plasma TNF-α and uMCP-1 showed a significant positive correlation with HbA1c (r=0.441, 0.643), hsCRP (r=0.400, 0.584) and MDA (r=0.423, 0.759) and significant negative correlation with GSH (R=-0.370, -0.800) and FRAP (r=-0.344, -0.684) Increased inflammatory markers viz. TNF-α, hsCRP and uMCP-1 and markers of oxidative stress i.e. increased MDA and decreased GSH and FRAP in DM-CKD suggest an important role of inflammation and oxidative stress in the pathogenesis of renal damage in diabetic patients.

Human C-reactive protein accentuates macrophage activity in biobreeding diabetic rats

OBJECTIVE

Type 1 diabetes (T1DM) is a pro-inflammatory state characterized by high C-reactive protein (CRP) levels. However, there is a paucity of data examining the role of CRP in promoting the pro-inflammatory state of diabetes. Thus, we examined the pro-inflammatory effects of human CRP using spontaneously diabetic bio-breeding (BB) rats.

METHODS

Diabetic rats (n=9/group) were injected with Human serum albumin (huSA) or Human CRP (hCRP, 20 mg/kg body weight; i.p.) for 3 consecutive days. Blood and peritoneal macrophages (MØ) were obtained following euthanasia. Peritoneal macrophages were used for measuring superoxide anion release, NF-κB DNA binding activity, proinflammatory mediator secretion.

RESULTS

hCRP administration resulted in significantly increased superoxide anion production, along with increased release of cytokines/chemokines, and plasminogen activator inhibitor (PAI-1) and Tissue Factor (TF) activity in diabetic rats compared to huSA. hCRP-treated BB rat MØ showed significant induction of protein kinase C (PKC)-alpha, PKC-delta and p47 phox expression and NF-κB compared to huSA.

CONCLUSIONS

Thus, our data suggest that human CRP exacerbates in-vivo the pro-inflammatory, pro-oxidant and procoagulant states of diabetes predominantly via increased macrophage activity and this could have implications with respect to vascular complications and anti-inflammatory therapies.

Tamoxifen alters the plasma concentration of molecules associated with cardiovascular risk in women with breast cancer undergoing chemotherapy

OBJECTIVES

The objective of this study was to evaluate the effect of tamoxifen on blood markers that are associated with cardiovascular risk, such as C-reactive protein (CRP), apolipoprotein A-1 (Apo-A), and apolipoprotein B-100 (Apo-B), in women undergoing chemotherapy for breast cancer.

METHODS

Over a period of 12 months, we followed 60 women with breast cancer. The women were divided into the following groups: a group that received only chemotherapy (n = 23), a group that received chemotherapy plus tamoxifen (n = 21), and a group that received only tamoxifen (n = 16). Plasma CRP levels were assessed at 0, 3, 6, and 12 months, and Apo-A and Apo B levels as well as the Apo-B/Apo-A ratio were assessed at 0 and 12 months.

RESULTS

We found increases in the plasma concentration of CRP in the chemotherapy alone and chemotherapy plus tamoxifen groups after 3 and 6 months of treatment (before the introduction of tamoxifen). However, after 12 months of treatment, women who used tamoxifen (the chemotherapy plus tamoxifen and tamoxifen alone groups) showed a significant reduction in CRP and Apo-B levels and a decrease in the Apo-B/Apo-A ratio. A significant increase in serum Apo-A levels was observed in the group receiving chemotherapy alone as a treatment for breast cancer.

CONCLUSION

The use of tamoxifen after chemotherapy for the treatment of breast cancer significantly reduces the levels of cardiovascular disease risk markers (CRP, Apo-B, and the Apo-B/Apo-A ratio).

Roux-en-Y gastric bypass and inflammatory activity of the adipose tissue

OBJECTIVE

To evaluate the oxidative stress and inflammatory markers in obese patients before and after Roux-en-Y vertical banded gastroplasty.

METHODS

We studied 20 class III obese patients undergoing Roux-en-Y vertical banded gastroplasty, seven men and 13 women, mean age 39 years, and 20 non-obese subjects, nine males and 11 females, mean age 38 years. We determined the plasma levels of malondialdehyde, stress an index, total antioxidant capacity, catalase, reduced and oxidized glutathione and inflammatory markers (C reactive protein and á-1 acid glycoprotein). In the obese group, these parameters were determined before and 2, 6 and 12 months after gastroplasty.

RESULTS

Preoperatively, the obese group showed elevated levels of inflammatory markers of oxidative stress (malondialdehyde levels and stress index) and lower levels of indicators of antioxidant defense compared to the control group. Weight loss was accompanied by gradual reduction in the levels of malondialdehyde and stress index. We found an increased concentration of reduced glutathione and total antioxidant status and reduced levels of inflammatory markers.

CONCLUSION

Weight loss improves the inflammatory state and oxidative stress levels.

Do statins have a role in reduction/prevention of post-PCI restenosis?

The pathophysiology of post-PCI restenosis involves neointimal formation that consists of three phases: thrombosis (within 24 h), recruitment (3-8 days), and proliferation, which starts on day 8 of PCI. Various factors suggested to be predictors/risks for restenosis include C-reactive protein (CRP), inflammatory mediators (cytokines and adhesion molecules), oxygen radicals, advanced glycation end products (AGEs) and their receptors (RAGE), and soluble RAGE (sRAGE). The earlier noted factors produce thrombogenesis, vascular smooth muscle cell proliferation, and extracellular matrix formation. Statins have pleiotropic effects. Besides lowering serum cholesterol, they have various other biological effects including antiinflammatory, antithrombotic, CRP-lowering, antioxidant, antimitotic, and inhibition of smooth muscle cell proliferation. They inhibit matrix metalloproteinase and cyclooxygenase-2, lower AGEs, decrease expression of RAGE and increase levels of serum sRAGE. They also increase the synthesis of nitric oxide (NO) by increasing endothelial NO synthase expression and activity. Preprocedural statin therapy is known to reduce peri- and post-PCI myonecrosis and reduce the need for repeat revascularization. There is evidence that statin-eluting stents inhibit in-stent restenosis in animal models. It is concluded that because of the above attributes of statins, they are suitable candidates for reduction of post-PCI restenosis and post-PCI myonecrosis. The future directions for the use of statins in reduction of post-PCI restenosis and myonecrosis have been discussed.

Acute infection-inflammation and coronary stent thrombosis: an observational study

Coronary stent thrombosis (CST) is a major concern of interventional cardiology. Several risk factors for CST have been identified, but as a whole they do not explain the pathophysiology of CST. This study was designed to investigate whether acute infection-inflammation could facilitate the occurrence of CST. Forty-one patients, aged 66.6 +/- 11 years, consecutively admitted to our catheterization laboratory for acute, subacute or late CST, were retrospectively analysed. Transient acute infection-inflammation on admission for CST was diagnosed by predefined criteria. Prevalence of known risk factors for CST was also investigated. Twenty-one patients (51%) met predefined criteria for the occurrence of acute infection-inflammation. On admission, in these patients, levels of systemic humoral and cellular inflammatory markers were significantly higher than those of patients without recent or ongoing acute infection-inflammation (p < 0.05 for all). 62% of patients with acute infection-inflammation had less than two known risk factors for CST whereas only 37% patients without infection-inflammation showed less than two risk factors (p = 0.03) and showed more frequent interruption of antiplatelet treatment (17 vs. 2.4%, p = 0.02), mean longer stent length (20.5 +/- 4.8 vs. 16.5 +/- 5.1 mm, p = 0.02) and lower left ventricular ejection fraction before CST (42.9 +/- 14 vs. 47.3 +/- 11%, p = 0.02). In conclusion, acute infection-inflammation could play a role in facilitating the occurrence of CST in a subgroup with low risk profile for known risk factors. Our findings, if confirmed, could suggest new opportunities for prevention and treatment of CST.

Vascular Function and Inflammation in Rheumatoid Arthritis: the Role of Physical Activity

Inflammation disturbs biochemical pathways involved in homeostasis of the endothelium. Research has established clear links between inflammatory mediators, particularly C-reactive protein and tumour necrosis factor alpha, endothelial dysfunction, and atherosclerosis. Endothelial dysfunction and atherosclerosis may be subclinical at early stages, and thus the ability to detect them with non-invasive techniques is crucially important, particularly in populations at increased risk for cardiovascular disease, such as those with rheumatoid arthritis. This may allow the identification of interventions that may reverse these processes early on. One of the best non-pharmacological interventions that may achieve this is physical activity. This review explores the associations between inflammation, endothelial dysfunction, and atherosclerosis and discusses the role of exercise in blocking specific pathways in the inflammation, endothelial dysfunction - atherosclerosis network.

Vascular function and inflammation in rheumatoid arthritis: the role of physical activity

Inflammation disturbs biochemical pathways involved in homeostasis of the endothelium. Research has established clear links between inflammatory mediators, particularly C-reactive protein and tumour necrosis factor alpha, endothelial dysfunction, and atherosclerosis. Endothelial dysfunction and atherosclerosis may be subclinical at early stages, and thus the ability to detect them with non-invasive techniques is crucially important, particularly in populations at increased risk for cardiovascular disease, such as those with rheumatoid arthritis. This may allow the identification of interventions that may reverse these processes early on. One of the best non-pharmacological interventions that may achieve this is physical activity. This review explores the associations between inflammation, endothelial dysfunction, and atherosclerosis and discusses the role of exercise in blocking specific pathways in the inflammation, endothelial dysfunction - atherosclerosis network.

Reduction in plasma levels of inflammatory and oxidative stress indicators after Roux-en-Y gastric bypass

BACKGROUND

Obesity is considered to be associated with high levels of oxidative stress and inflammation. Anticipated weight loss secondary to bariatric surgery may offer an opportunity to evaluate this association. We studied a few markers of oxidative stress and inflammation in 20 obese patients submitted to Roux-en-Y gastric bypass (RYGBP).

METHODS

Variations in plasma levels of indicators of oxidative stress (malondialdehyde (MDA), superoxide dismutase (SOD), catalase, glutathione (GSH), glutathione disulfide (GSSG), and total radical antioxidant parameter (TRAP)) and inflammation (alpha1-acid glycoprotein (AGP) and C-reactive protein (CRP)), as well as variations in plasma levels of leptin, glucose, glycated hemoglobin (HbA1c), and insulin were investigated in the preoperative period and 12 months postsurgery in 20 class III obese individuals submitted to bariatric surgery (obese group) and 20 non-obese individuals (control group).

RESULTS

Twelve months postsurgery, there was a significant reduction (p < 0.01) in median values of BMI (46.75/30.17 kg/m(2)) and in plasma levels of MDA (16.70/9.11 nmol/g prot), SOD (10.70/9.24 U/mgHb), GSSG (210.80/148.20 mM/g of Hb), AGP (125.70/75.80 mg/dL), CRP (1.31/0.38 mg/dL), and leptin (15.04/3.58 ng/mL). A significant drop (p < 0.05) in plasma levels of HbA1c (5.81/4.98%) was also observed. On the other hand, a significant increase in plasma levels of GSH (2.002/2.823 mM/g of Hb) and TRAP (585.40/815.48 microM Trolox), p < 0.01, and in catalase plasma levels (12.06/13.22 Deltat/mgHb/min), p < 0.05, was seen. No statistically significant variations in glucose (96.3/84.8 mg/dL) or insulin plasma levels (9.91/7.88 U/mL) occurred. Calculated homeostasis model assessment index did not statistically change 12 months postsurgery (2.36/1.66).

CONCLUSIONS

In the preoperative period, the obese group individuals showed higher oxidation and inflammation levels and lower indices of antioxidant defense than those of the control group. One year after RYGBP, an improvement in antioxidant protection, associated with a reduction in inflammatory and oxidative markers, was observed, indicating that these individuals presented a lower degree of oxidative stress.

The evolving role of C-reactive protein in atherothrombosis

BACKGROUND

Inflammation is pivotal in all phases of atherosclerosis. Among the numerous inflammatory biomarkers, the largest amount of published data supports a role for C-reactive protein (CRP) as a robust and independent risk marker in the prediction of primary and secondary adverse cardiovascular events. In addition to being a risk marker, there is much evidence indicating that CRP may indeed participate in atherogenesis.

CONTENT

In this review, we focus on the role of CRP in promoting atherothrombosis by discussing its effects on endothelial cells, endothelial progenitor cells, monocyte-macrophages, and smooth muscle cells.

CONCLUSIONS

CRP is clearly a risk marker for cardiovascular disease and is recommended for use in primary prevention. In addition, CRP appears also to contribute to atherogenesis. However, much further research is needed, especially in appropriate animal models, to confirm the possible role of CRP in promoting atherothrombosis.

C-reactive protein stimulates superoxide anion release and tissue factor activity in vivo

C-reactive protein (CRP), the prototypic marker of inflammation, is a cardiovascular risk marker and recent in vitro studies suggest that it may promote atherogenesis. CRP promotes oxidative stress in vitro and induces tissue factor (TF) release. However, there is a paucity of data examining the effects of CRP on oxidative stress and tissue factor procoagulant activity (PCA) in vivo. Thus, we tested the effects of CRP administration on superoxide anion release and tissue factor activity and examined mechanistic pathways using a rat sterile air pouch model. Intraperitoneal administration of CRP (20mg/kg body weight) compared to human serum albumin (HuSA) increased superoxide anion release and tissue factor activity from peritoneal macrophages in vivo (p<0.01). This was confirmed using intrapouch administration of CRP (25mug/mL) compared to HuSA. Pretreatment with reactive oxygen species (ROS) scavengers or protein kinase C (PKC) inhibitor significantly abrogated CRP-induced superoxide anion release and tissue factor activity. Pretreatment with extracellular signal-regulated kinase (ERK) and Jun N-terminal kinase (JNK) inhibitors, but not p38 mitogen-activated protein kinase (p38MAPK) significantly decreased CRP-induced superoxide anion release from macrophages in vivo. CRP-induced tissue factor activity in vivo was abrogated by pretreatment with inhibitors to p38MAPK, JNK and NFkappab (nuclear factor-kappab), but not ERK. Antibodies to Fc gamma receptors, CD32 and CD64 resulted in significant reduction in CRP-induced superoxide and tissue factor activity in vivo. Thus, CRP appears to induce oxidative stress in vivo by stimulating NADPH oxidase via PKC, ERK and JNK phosphorylation, and induces tissue factor PCA in vivo via upregulation of PKC, p38MAPK, JNK, ROS and NFkappab. CRP-induced ROS appears to precede tissue factor release. These effects are abrogated by blocking Fc gamma receptors, CD32 and CD64. This in vivo demonstration provides further evidence for a role for CRP in atherothrombosis.

C-reactive protein (CRP)-lowering agents

C-reactive protein (CRP) plays a role in the pathogenesis of cardiovascular disease. It is a marker and predictor of cardiovascular disease. CRP possesses numerous cardiovascular effects (clotting, generation of oxygen radicals, increase in the expression of adhesion molecules and plasminogen activator inhibitor-1, plaque destabilization) that could result in cardiovascular disease. This review describes the effects of various cardiovascular drugs on the levels of CRP in health and disease. Cyclooxygenase inhibitors (aspirin, rofecoxib, celecoxib), platelet aggregation inhibitors (clopidogrel, abciximab), lipid lowering agents (statins, ezetimibe, fenofibrate, niacin, diets), beta-adrenoreceptor antagonists and antioxidants (vitamin E), as well as angiotensin converting enzyme (ACE) inhibitors (ramipril, captopril, fosinopril), reduce serum levels of CRP; while enalapril and trandolapril have not been shown to have the same effect. Angiotensin receptor blockers (ARBs) (valsartan, irbesartan, olmesartan, telmisartan) markedly reduce serum levels of CRP. The findings with other ARBs (losartan and candesartan) were inconsistent. Antidiabetic agents (rosiglitazone and pioglitazone) reduce CRP levels, while insulin is ineffective. Calcium channel antagonists have variable effects on CRP levels. Hydrochlorothiazide and oral estrogen do not affect CRP. The CRP-lowering effect of statins is more pronounced than their lipid lowering effect and is not dependent on their hypolipemic activity. The effect of atorvastatin on CRP seems to be dose-dependent. CRP-lowering effect of statins is likely to contribute to the favorable outcome of statin therapy. The data suggest that lipid lowering agents, ACE inhibitors, ARBs, antidiabetic agents, antiinflammatory and antiplatelet agents, vitamin E, and beta-adrenoreceptor antagonists lower serum or plasma levels of CRP, while vitamin C, oral estrogen and hydrochlorothiazide do not affect CRP levels.

A proatherogenic role for C-reactive protein in vivo

PURPOSE OF REVIEW

We have selectively reviewed some of the latest papers on the mechanistic role of C-reactive protein in atherosclerotic cardiovascular disease.

RECENT DEVELOPMENTS

C-reactive protein is known to activate the classic pathway of the complement system. One paper examined the role of C-reactive protein in complement activation by enzymatically remodeled LDL proteins. Enzymatically remodeled LDL was found to induce complement activation with or without C-reactive protein, but in the presence of C-reactive protein the activation of complement halted before its terminal sequence. Complement activation by C-reactive protein in atherogenesis remains controversial. Different laboratories have reported the multi-organ origin of C-reactive protein. The atherosclerotic lesion itself is another place where C-reactive protein could be produced. Numerous studies have continued to dissect the potential diverse proatherogenic actions of C-reactive protein on cultured vascular cells. Caution must be exercised in inadequately controlled studies that have unwittingly used commercial C-reactive protein preparations contaminated by other bioactive components. In contrast to in-vitro experiments, in-vivo studies that support a proatherogenic role of C-reactive protein are less likely to be subject to misinterpretation.

SUMMARY

Evidence suggests that C-reactive protein is a proatherogenic molecule that plays an active role. The amount of C-reactive protein in lesions is determined by its plasma levels and its local production. The biological effect of C-reactive protein on atherosclerosis development seems to encompass a complex network of interactions with other players in immunity and inflammation, such as the complement system, as well as a direct effect of C-reactive protein on the cells involved in lesion growth and development.

Elastin peptides induced oxidation of LDL by phagocytic cells

The degradation products of one of the major component of vascular wall, elastin, have several important biological activities. Elastin peptides (KE) are mostly generated during vascular aging and the atherosclerotic process. They induce free radical and proteases production from cells, which are the major components of the atherosclerotic process. In the present study, we investigated whether the interaction between elastin peptides and neutrophils as well as monocytes contributes to low density lipoproteins (LDL) oxidation, being one of the most important initiator of the chronic inflammatory process contributing to the development of atherosclerosis. Here, we present data on the link between the elastin degradation products and LDL oxidation by the chemotactically attracted neutrophils and monocytes. The KE as well as the active epitope, the hexapeptide VGVAPG is able, in a differential concentration and time dependence, to induce the oxidation of LDL. KE is able to induce via the production of free radicals by neutrophils the oxidation of LDL very rapidly and in higher concentration compared to monocytes. These effects of KE are occurring through the stimulation of the 67 kDa elastin-laminin receptor (ELR), as demonstrated by the uncoupling effect of lactose. In our present study, the HDL was able to decrease the LDL oxidation by KE. This is a new mechanism by which elastin peptides might participate in the initiation and progression of the atherosclerotic process.