Statins as anti-inflammatory agents in atherogenesis: molecular mechanisms and lessons from the recent clinical trials

Vascular endothelial dysfunction and pharmacological treatment

The endothelium exerts multiple actions involving regulation of vascular permeability and tone, coagulation and fibrinolysis, inflammatory and immunological reactions and cell growth. Alterations of one or more such actions may cause vascular endothelial dysfunction. Different risk factors such as hypercholesterolemia, homocystinemia, hyperglycemia, hypertension, smoking, inflammation, and aging contribute to the development of endothelial dysfunction. Mechanisms underlying endothelial dysfunction are multiple, including impaired endothelium-derived vasodilators, enhanced endothelium-derived vasoconstrictors, over production of reactive oxygen species and reactive nitrogen species, activation of inflammatory and immune reactions, and imbalance of coagulation and fibrinolysis. Endothelial dysfunction occurs in many cardiovascular diseases, which involves different mechanisms, depending on specific risk factors affecting the disease. Among these mechanisms, a reduction in nitric oxide (NO) bioavailability plays a central role in the development of endothelial dysfunction because NO exerts diverse physiological actions, including vasodilation, anti-inflammation, antiplatelet, antiproliferation and antimigration. Experimental and clinical studies have demonstrated that a variety of currently used or investigational drugs, such as angiotensin-converting enzyme inhibitors, angiotensin AT1 receptors blockers, angiotensin-(1-7), antioxidants, beta-blockers, calcium channel blockers, endothelial NO synthase enhancers, phosphodiesterase 5 inhibitors, sphingosine-1-phosphate and statins, exert endothelial protective effects. Due to the difference in mechanisms of action, these drugs need to be used according to specific mechanisms underlying endothelial dysfunction of the disease.

N-Acetylneuraminic Acid Supplementation Prevents High Fat Diet-Induced Insulin Resistance in Rats through Transcriptional and Nontranscriptional Mechanisms

N-Acetylneuraminic acid (Neu5Ac) is a biomarker of cardiometabolic diseases. In the present study, we tested the hypothesis that dietary Neu5Ac may improve cardiometabolic indices. A high fat diet (HFD) + Neu5Ac (50 or 400 mg/kg BW/day) was fed to rats and compared with HFD + simvastatin (10 mg/kg BW/day) or HFD alone for 12 weeks. Weights and serum biochemicals (lipid profile, oral glucose tolerance test, leptin, adiponectin, and insulin) were measured, and mRNA levels of insulin signaling genes were determined. The results indicated that low and high doses of sialic acid (SA) improved metabolic indices, although only the oral glucose tolerance test, serum triglycerides, leptin, and adiponectin were significantly better than those in the HFD and HFD + simvastatin groups (P < 0.05). Furthermore, the results showed that only high-dose SA significantly affected the transcription of hepatic and adipose tissue insulin signaling genes. The data suggested that SA prevented HFD-induced insulin resistance in rats after 12 weeks of administration through nontranscriptionally mediated biochemical changes that may have differentially sialylated glycoprotein structures at a low dose. At higher doses, SA induced transcriptional regulation of insulin signaling genes. These effects suggest that low and high doses of SA may produce similar metabolic outcomes in relation to insulin sensitivity through multiple mechanisms. These findings are worth studying further.

High fat diet-induced inflammation and oxidative stress are attenuated by N-acetylneuraminic acid in rats

Background

Serum sialic acid levels are positively correlated with coronary artery disease and inflammation. Although sialic acid is a non-specific marker, it is considered sensitive likely due to its influence in sialylation of glycoprotein structures all over the body.

Objectives

We hypothesized that dietary supplementation with N-acetylneuraminic acid (Neu5Ac), a type of sialic acid, will have profound effects on high fat diet- (HFD-) induced inflammation and oxidative stress in view of the widespread incorporation of sialic acid into glycoprotein structures in the body.

Methods

HFD-fed rats with or without simvastatin or Neu5Ac (50 and 400 mg/kg/day) were followed up for 12 weeks. Lipid profiles, and markers of inflammation (C-reactive protein, interleukin-6, and tumor necrosis factor alpha), insulin resistance (serum insulin and adiponectin, oral glucose tolerance test and homeostatic model of insulin resistance) and oxidative stress (total antioxidant status and thiobarbituric acid reactive species) in the serum and liver were determined, while mRNA levels of hepatic antioxidant and inflammation genes were also quantified. Serum levels of alanine transaminase, aspartate transaminase, alkaline phosphatase, urea, creatinine and uric acid were also assessed.

Results

HFD feeding caused hyperlipidemia and insulin resistance, and worsened liver and kidney functions. HFD feeding also potentiated inflammation and oxidative stress, partly through modulation of hepatic gene expression, while Neu5Ac especially at higher doses and simvastatin attenuated HFD-induced changes, although Neu5Ac showed better outcomes.

Conclusions

Based on the present results, we surmised that Neu5Ac can prevent HFD-induced inflammation and oxidative stress, and may in fact be useful in the prevention of hyperlipidemia-associated inflammation and oxidative stress. However, the translational implications of these findings can only be determined after long-term effects are established. Hence, the use of Neu5Ac on obesity-related diseases requires additional attention.

In vivo evidence for chylomicrons as mediators of postprandial inflammation

BACKGROUND AND AIMS

The postprandial situation is a pro-inflammatory condition most likely linked to the development of atherosclerosis. We evaluated the relationship between apolipoprotein (apo) B48 and fasting and postprandial leukocyte activation markers.

METHODS

Leukocyte activation markers and apo B48 were determined in 80 subjects with and without coronary artery disease (CAD). Twelve healthy subjects underwent an oral fat loading test (up to 8 h).

RESULTS

Fasting apo B48 was significantly higher in patients with CAD (n = 47, 8.1 ± 5.2 mg/L) than in subjects without CAD (n = 33, 5.9 ± 3.9 mg/L, p = 0.022). Fasting apo B48 and triglycerides correlated positively with fasting monocyte CD11b and neutrophil CD66b expression. Plasma apo B48 and leukocyte activation markers increased after an oral fat load. No correlations were found between fasting or postprandial triglycerides and postprandial leukocyte activation markers. We observed no correlations between postprandial apo B48 and postprandial neutrophil CD11b or CD66b expression.

CONCLUSION

This study suggests that chylomicron remnants may be responsible for postprandial leukocyte activation in the circulation. The postprandial chylomicron response may be a stronger mediator of postprandial inflammation than postprandial triglyceridemia.

Recent developments in modulating atherogenic lipoproteins

PURPOSE OF REVIEW

Randomized clinical trials have assessed the effects of several classes of drugs on plasma cholesterol levels in patients with coronary artery disease. Agents including niacin, fibrates and statins significantly lower LDL-cholesterol, but tolerance issues and undesirable side-effects are common. Residual risk may also be present in patients with persistently low HDL-cholesterol despite a reduction in LDL-cholesterol. Recent trials of drugs that increase circulating HDL-cholesterol have also been disappointing.

RECENT FINDINGS

Ongoing efforts target the development of new pharmacotherapies to reduce circulating levels of atherogenic lipoproteins. The goal of this review is to discuss recent advances in the treatment of coronary artery disease and other vascular diseases characterized by an increase in circulating atherogenic lipoproteins. These include the development of inhibitors of ATP citrate lyase and proprotein convertase subtilisin/kexin type 9. We also discuss recent developments in HDL therapy, including the clinical assessment of cholesteryl ester transfer protein inhibitors and apolipoprotein E mimetic peptides.

SUMMARY

Several new classes of drug are undergoing clinical evaluation that show promise for atherogenic lipoprotein reduction in patients who are statin intolerant.

Edible Bird's Nest attenuates high fat diet-induced oxidative stress and inflammation via regulation of hepatic antioxidant and inflammatory genes

BACKGROUND

Edible Bird's nest (EBN) is an antioxidant-rich supplement that is popular in many parts of Asia. Its antioxidant and anti-inflammatory properties have been reported using in vitro system. This paper aimed to determine the antioxidant and anti-inflammatory effects of EBN in in high fat diet induced rats model.

METHODS

We evaluate if those properties can be translated in rats. High fat diet (HFD) was fed to rats for 12 weeks to determine its effects on oxidative stress and inflammation, and compared with HFD + Simvastatin and HFD + EBN (2.5 or 20 %). Weights were measured weekly, while serum and hepatic markers of oxidative stress (total antioxidant status and TBARS) and inflammation (interleukin 6 [IL-6], C-reactive protein [CRP] and tumor necrosis factor alpha [TNF-α]) were determined at the end of the intervention. In addition, transcriptional changes in hepatic antioxidant (superoxide dismutase, glutathione reductase, glutathione peroxidase) and inflammation (C-reactive protein, chemokine [C-C] motif 2, nuclear factor kappa beta 1 and tumor necrosis factor alpha) genes were evaluated.

RESULTS

The results showed increases in oxidative stress (raised TBARS and lowered total antioxidant status) and inflammatory markers (raised CRP, IL-6 and TNF-α) in HFD induced rats with corresponding attenuation of antioxidant gene expression and potentiation of inflammatory gene expression. EBN on the other hand attenuated the HFD-induced inflammation and oxidative stress and produced overall better outcomes in comparison with simvastatin.

CONCLUSIONS

In aggregate, the results support the evidence-based utilization of EBN as a supplement for preventing obesity-related inflammation and oxidative stress in rats. These promising results can open up opportunities for translating the benefits of EBN to humans.

Association Between Use of Statins and Mortality in Patients With Heart Failure and Ejection Fraction of ≥50%

Background—

The pathophysiology of heart failure with preserved ejection fraction is poorly understood, but may involve a systemic proinflammatory state. Therefore, statins might improve outcomes in patients with heart failure with preserved ejection fraction defined as ≥50%.

Methods and Results—

Of 46 959 unique patients in the prospective Swedish Heart Failure Registry, 9140 patients had heart failure and ejection fraction ≥50% (age 77±11 years, 54.0% women), and of these, 3427 (37.5%) were treated with statins. Propensity scores for statin treatment were derived from 40 baseline variables. The association between statin use and primary (all-cause mortality) and secondary (separately, cardiovascular mortality, and combined all-cause mortality or cardiovascular hospitalization) end points was assessed with Cox regressions in a population matched 1:1 based on age and propensity score. In the matched population, 1-year survival was 85.1% for statin-treated versus 80.9% for untreated patients (hazard ratio, 0.80; 95% confidence interval, 0.72–0.89; P <0.001). Statins were also associated with reduced cardiovascular death (hazard ratio, 0.86; 95% confidence interval, 0.75–0.98; P =0.026) and composite all-cause mortality or cardiovascular hospitalization (hazard ratio, 0.89; 95% confidence interval, 0.82–0.96; P =0.003).

Conclusions—

In heart failure with ejection fraction ≥50%, the use of statins was associated with improved outcomes. The mechanisms should be evaluated and the effects tested in a randomized trial.

Aspirin and statin use and the subsequent development of depression in men and women: Results from a longitudinal population-based study

OBJECTIVE

Low-grade chronic inflammation is one potential mechanism underlying the well-established association between major depressive disorder (MDD) and increased cardiovascular morbidity. Both aspirin and statins have anti-inflammatory properties, which may contribute to their preventive effect on cardiovascular diseases. Previous studies on the potentially preventive effect of these drugs on depression have provided inconsistent results. The aim of the present paper was to assess the prospective association between regular aspirin or statin use and the incidence of MDD.

METHOD

This prospective cohort study included 1631 subjects (43.6% women, mean age 51.7 years), randomly selected from the general population of an urban area. Subjects underwent a thorough physical evaluation as well as semi-structured interviews investigating DSM-IV mental disorders at baseline and follow-up (mean duration 5.2 years). Analyses were adjusted for a wide array of potential confounders.

RESULTS

Our main finding was that regular aspirin or statin use at baseline did not reduce the incidence of MDD during follow-up, regardless of sex or age (hazard ratios, aspirin: 1.19; 95%CI, 0.68-2.08; and statins: 1.25; 95%CI, 0.73-2.14; respectively).

LIMITATIONS

Our study is not a randomized clinical trial and could not adjust for all potential confounding factors, information on aspirin or statin use was collected only for the 6 months prior to the evaluations, and the sample was restricted to subjects between 35 and 66 years of age.

CONCLUSION

Our data do not support a large scale preventive treatment of depression using aspirin or statins in subjects aged from 35 to 66 years from the community.

T lymphocytes and fractalkine contribute to myocardial ischemia/reperfusion injury in patients

BACKGROUND

Lymphocytes contribute to ischemia/reperfusion (I/R) injury in several organ systems, but their relevance in ST elevation myocardial infarction (STEMI) is unknown. Our goal was to characterize lymphocyte dynamics in individuals after primary percutaneous coronary intervention (PPCI), assess the prognostic relevance of these cells, and explore mechanisms of lymphocyte-associated injury.

METHODS

Lymphocyte counts were retrospectively analyzed in 1,377 STEMI patients, and the prognostic relevance of post-PPCI lymphopenia was assessed by Cox proportional hazards regression. Blood from 59 prospectively recruited STEMI patients undergoing PPCI was sampled, and leukocyte subpopulations were quantified. Microvascular obstruction (MVO), a component of I/R injury, was assessed using MRI.

RESULTS

In the retrospective cohort, lymphopenia was associated with a lower rate of survival at 3 years (82.8% vs. 96.3%, lowest vs. highest tertile; hazard ratio 2.42). In the prospective cohort, lymphocyte counts fell 90 minutes after reperfusion, primarily due to loss of T cells. CD8+ T cells decreased more than CD4+ T cells, and effector subsets exhibited the largest decline. The early decrease in effector T cell levels was greater in individuals that developed substantial MVO. The drop in T cell subsets correlated with expression of the fractalkine receptor CX3CR1 (r2 = 0.99, P = 0.006). Serum fractalkine concentration peaked at 90 minutes after reperfusion, coinciding with the T cell count nadir.

CONCLUSIONS

Lymphopenia following PPCI is associated with poor prognosis. Our data suggest that fractalkine contributes to lymphocyte shifts, which may influence development of MVO through the action of effector T cells.

TRIAL REGISTRATION

Not applicable.

FUNDING

British Heart Foundation (FS/12/31/29533) and National Institute of Health Research (NIHR) Newcastle Biomedical Research Centre.

Lipid profile of rheumatoid arthritis patients treated with anti-tumor necrosis factor-alpha drugs changes according to disease activity and predicts clinical response

Patients with active rheumatoid arthritis (RA) frequently show an atherogenic lipid profile, which has been linked with the inflammatory reaction. Inflammatory cytokines, and particularly tumor necrosis factor-alpha (TNF-α), are implicated in the pathogenesis of both atherosclerosis and RA, and also involved in the development of the impaired lipid profile detected in active RA. Although anti-TNF-α agents have been proven effective in controlling joint damage and systemic inflammation, controversy remains about the effect of these drugs on the lipid profile; therefore, the aim of our study was to investigate the effect of anti-TNF-α treatment, in combination with disease-modifying anti-rheumatic drugs (DMARDs) and corticosteroid therapy, on the lipid profile of patients with active RA. Our data suggest that the combination anti-TNF-α/DMARDs/steroids do not significantly interfere with the lipid profile of RA patients. However, analysis of clinical response data showed that patients achieving low disease activity or remission seem to have a protective lipid profile, suggesting that better control of inflammation and disease activity can affect lipid metabolism. The available evidence indicates that high inflammation interferes with lipid metabolism, whereas good control of the chronic inflammatory state may positively influence the lipid profile and cardiovascular risk. Low cholesterol levels at baseline could predict a favorable outcome with anti-TNF-α treatment, but these data need to be confirmed by large prospective studies with long-term follow-up.

The Ins and Outs of Small GTPase Rac1 in the Vasculature

The Rho family of small GTPases forms a 20-member family within the Ras superfamily of GTP-dependent enzymes that are activated by a variety of extracellular signals. The most well known Rho family members are RhoA (Ras homolog gene family, member A), Cdc42 (cell division control protein 42), and Rac1 (Ras-related C3 botulinum toxin substrate 1), which affect intracellular signaling pathways that regulate a plethora of critical cellular functions, such as oxidative stress, cellular contacts, migration, and proliferation. In this review, we describe the current knowledge on the role of GTPase Rac1 in the vasculature. Whereas most recent reviews focus on the role of vascular Rac1 in endothelial cells, in the present review we also highlight the functional involvement of Rac1 in other vascular cells types, namely, smooth muscle cells present in the media and fibroblasts located in the adventitia of the vessel wall. Collectively, this overview shows that Rac1 activity is involved in various functions within one cell type at distinct locations within the cell, and that there are overlapping but also cell type-specific functions in the vasculature. Chronically enhanced Rac1 activity seems to contribute to vascular pathology; however, Rac1 is essential to vascular homeostasis, which makes Rac1 inhibition as a therapeutic option a delicate balancing act.

Myocardial Infarction, Stroke, and Mortality in cART-Treated HIV Patients on Statins

Despite combination antiretroviral therapy (cART), people living with HIV (PLWH) continue to have more systemic inflammation and metabolic disturbances than the general population. These risk factors for atherosclerosis and organ dysfunction may be ameliorated by statins. We retrospectively analyzed 438 cART treated PLWH from the Nutrition For Healthy Living (NFHL) cohort to determine the association between statins and myocardial infarction (MI), stroke, and all-cause mortality as a composite. We used Cox proportional hazards regression as our main analysis. The average age was 44 years, 32% were women, and 67 of the 438 subjects used statins. There was no association between statins and our composite endpoint in two separate models [1.26 (0.57-2.79) in statin history model and 0.93 (0.65-1.32) per year in statin duration model]. The composite outcome was significantly associated with CD4 count, age, and smoking status in both models. CD4 count remained significant even after exclusion of mortality from the composite (HR=0.88, p=0.02). Confounding control via propensity scoring and multiple imputations did not change the results. Statins did not have an effect on MI, stroke, and mortality. Interestingly, CD4 count appears to be an important predictor of these outcomes, even after exclusion of death from the composite.

Effects of rosuvastatin combined with fasudil therapy on rabbits with dyslipidemia

BACKGROUND

Present study was conducted to investigate the effects of rosuvastatin combined with fasudil on rabbits with dyslipidemia.

METHODS

Dyslipidemia model of rabbits were produced by prescribing atherogenic diet for 2 weeks. Thereafter, 40 rabbits with dyslipidemia were randomly and evenly divided into four groups as follow: untreated group (orally prescribed 3 ml of normal saline), rosuvastatin group (orally prescribed 3 mg/kg body weight daily, dissolved in 3 ml of normal saline), fasudil group (intravenously prescribed 0.5 mg/kg body weight daily, dissolved in 3 ml of normal saline), and combined group (the same doses of rosuvastatin and fasudil as aforementioned). At baseline, 2 weeks of dyslipidemia establishment and 2 weeks of medical therapy, fasting venous blood was drawn for laboratory examination.

RESULTS

After 2 weeks' atherogenic diet treatment, lipid disorders and impaired fasting glucose were observed. Systemic inflammation and oxidation were also promoted as revealed by increased serum levels of high sensitive C-reactive protein (Hs-CRP) and malondialdehyde (MDA). Notably, endothelial function has been impaired significantly as reflected by decreased nitric oxide (NO) production and increased serum asymmetric dimethylarginine (ADMA) level. RhoA associated kinase (ROCK) activity was also profoundly enhanced (P < 0.05). Inter-group comparisons showed that when compared to untreated group, modest improvements of endothelial function, inflammation and oxidation were observed in rosuvastatin and fasudil groups (P > 0.05). These benefits were improved more prominently in combined group (P < 0.05). Intra-group comparisons also showed that when compared to 2 weeks of dyslipidemia, slight improvement of endothelial function, inflammation and oxidation in rosuvastatin and fasudil groups were observed (P > 0.05). The improvements were more prominent in the combined groups (P < 0.05).

CONCLUSION

Rosuvastatin combined with fasudil conferred synergistic effects on endothelium-protection and inflammation- and oxidation-amelioration in the setting of early stage of dyslipidemia.

High Incidence of ACE/PAI-1 in Association to a Spectrum of Other Polymorphic Cardiovascular Genes Involving PBMCs Proinflammatory Cytokines in Hypertensive Hypercholesterolemic Patients: Reversibility with a Combination of ACE Inhibitor and Statin

Cardiovascular diseases (CVDs) are significantly high in the Lebanese population with the two most predominant forms being atherosclerosis and venous thrombosis. The purpose of our study was to assess the association of a spectrum of CVD related genes and combined state of hypertension hypercholesterolemia (HH) in unrelated Lebanese. Twelve polymorphisms were studied by multiplex PCR and reverse hybridization of DNA from 171 healthy individuals and 144 HH subjects. Two genes were significantly associated with HH: ACE (OR: 9.20, P<0.0001) and PAI-1 (OR: 2.29, P = 0.007), respectively with the occurrence of the risky alleles “Del” and “4G”. The frequencies of the Del and 4G alleles were found to be 0.98 and 0.90 in the HH group versus 0.84 and 0.79 in the healthy group, respectively. Serum ACE activity and PAI-I increased significantly with Del/Del and 4G/5G genotypes. The co-expression of Del/4G(+/+) was detected in 113 out of 171 (66.0%) controls and 125 out of 144 (86.8%) HH subjects. Del/4G(-/-) was detected in only 6 (3.5%) controls and undetected in the HH group. Three venous thrombosis related genes [FV(Leiden), MTHFR(A1298C) and FXIII(V34L)] were significantly related to the prominence of the co-expression of Del/4G(+/+). A range of 2 to 8 combined polymorphisms co-expressed per subject where 5 mutations were the most detected. In Del/4G(+/+) subjects, peripheral blood mononuclear cells (PBMCs) produced significant elevated levels of IFN-γ and TNF-α contrary to IL-10, and no variations occurred for IL-4. ACE inhibitor (ramipril) in combination with statin (atorvastatin) and not alone reversed significantly the situation. This first report from Lebanon sheds light on an additional genetic predisposition of a complex spectrum of genes involved in CVD and suggests that the most requested gene FVL by physicians may not be sufficient to diagnose eventual future problems that can occur in the cardiovascular system. Subjects expressing the double mutations (Del/4G) are at high risk for the onset of CVDs.

Atorvastatin protects endothelium by decreasing asymmetric dimethylarginine in dyslipidemia rats

Background

Asymmetric Dimethylarginine (ADMA) is an inhibitor of endogenous nitric oxide synthase, which is the key synthase for nitric oxide (NO) production. Whether statins could protect endothelium by reducing ADMA concentration is unclear, and whether this effect is associated with the dose of statins usage is also needed further studied.

Methods

Dyslipidemia rat model was produced by giving high-fat and high-cholesterol diet for 8 weeks. Thereafter, low-dose (5 mg/kg body weight/day) and high-dose (20 mg/kg body weight/day) atorvastatin were orally prescribed for 4 weeks. Parameters of interest including lipid profiles, inflammatory and oxidative markers, NO production and plasma levels of ADMA and ADMA concentration of myocardium were evaluated. Liver enzymes and creatinine kinase (CK) were also detected for safety concern.

Results

At baseline, all parameters were comparable between the sham and the dyslipidemia groups. At 8 weeks of dyslipidemia establishment, as compared to the sham group, body weight and lipid profiles were significantly elevated, and plasma levels of C-reactive protein (CRP), malondialdehyde (MDA) and ADMA were concomitantly increased in accompanying with NO reduction in the dyslipidemia groups. With 4 weeks of atorvastatin therapy, as compared to the control group, lipid disorders and NO production were improved, and plasma levels of CRP, MDA and ADMA were significantly decreased in the high-dose atorvastatin group. ADMA concentration of cardiac tissues was also significantly reduced in the high-dose atorvastatin group. Notably, there was a trend to similar effects which did not reach statistical significance in the low-dose atorvastatin group when compared to the control group. Liver enzyme and CK were comparable after 4 weeks of atorvastatin therapy between groups.

Conclusion

In rats with dyslipidemia, atorvastatin therapy could reduce plasma level of ADMA and ADMA concentration in cardiac tissues, and these effects are associated with the dose of atorvastatin therapy.

Possible mechanisms of C-reactive protein mediated acute myocardial infarction

Myocardial infarction is a relevant cardiovascular event worldwide for morbidity and mortality. It has been theorized that acute myocardial infarctions (AMIs) and other acute coronary events that are precipitated by atherosclerosis are due to arterial blockage from fat deposits. It is now known, however, that atherosclerosis involves more than just lipids. Inflammation has also been studied extensively to play a substantial role in myocardial infarction. There have been debates and conflicting reports over the past few years about the value of assessing levels of C-reactive protein and other biomarkers of inflammation for the prediction of cardiovascular events. Several studies have shown that CRP is not only an inflammatory marker, but also involved in the pathogenesis of myocardial infarction. Studies have linked atherogenesis and rupture of atherosclerotic lesion to endothelial dysfunction. CRP directly inhibits endothelial cell nitric oxide (NO) production via destabilizing endothelial NO synthase (eNOS). Decreased NO release causes CRP mediated inhibition of angiogenesis, stimulating endothelial cell apoptosis. CRP can also activate the complement system through the classical pathway. Complement activation plays an important role in mediating monocyte and neutrophil recruitment in an injured myocardium and may therefore lead to increase in infarct size. This article discusses the possible roles of CRP in complement activation, endothelial dysfunction and its impact on the development of myocardial infarction. We also reviewed the possible therapeutic approaches to myocardial infarction.

Targeting the adaptive immune system: new strategies in the treatment of atherosclerosis

Atherosclerosis is a lipid-driven chronic inflammatory disease of the arterial wall. Current treatment of atherosclerosis is focused on limiting its risk factors, such as hyperlipidemia or hypertension. However, treatments that target the inflammatory nature of atherosclerosis are still under development. Discovery of novel targets involved in the inflammation of the arterial wall creates opportunities to design new therapeutics that successfully modulate atherosclerosis. Here, we review drug targets that have proven to play pivotal roles in the adaptive immune system in atherosclerosis, and we discuss their potential as novel therapeutics.

Epidemiology and management of antiretroviral-associated cardiovascular disease

Risk and manifestations of cardiovascular disease (CVD) in patients infected with human immunodeficiency virus (HIV) will continue to evolve as improved treatments and life expectancy of these patients increases. Although initiation of antiretroviral (ARV) therapy has been shown to reduce this risk, some ARV medications may induce metabolic abnormalities, further compounding the risk of CVD. In this patient population, both pharmacologic and nonpharmacologic strategies should be employed to treat and reduce further risk of CVD. This review summarizes epidemiology data of the risk factors and development of CVD in HIV and provides recommendations to manage CVD in HIV-infected patients.

Release Kinetics of Inflammatory Biomarkers in a Clinical Model of Acute Myocardial Infarction

Rationale:

Inflammation in the setting of acute myocardial infarction (MI) has been linked to risk stratification; however, the release kinetics of inflammatory biomarkers in patients with acute MI has been difficult to establish.

Objective:

The aim of this study was to determine the kinetics of changes in the levels of several biomarkers specifically linked to inflammation after transcoronary ablation of septal hypertrophy, a procedure that mimics acute MI.

Methods and Results:

We analyzed release kinetics of C-reactive protein, high-sensitivity C-reactive protein, interleukin-6, soluble CD40 ligand, and peripheral blood leukocyte subsets in patients (n=21) undergoing transcoronary ablation of septal hypertrophy. Blood samples were collected before transcoronary ablation of septal hypertrophy and at various times after transcoronary ablation of septal hypertrophy. Serum levels of C-reactive protein were increased at 24 hours (1.0 mg/dL [interquartile range [IQR], 0.7–1.75] versus 0.2 mg/dL [IQR, 0.1–1.05] at baseline [BL]; P <0.001), whereas high-sensitivity C-reactive protein increased as early as 8 hours (2.68 mg/L [IQR, 1.23–11.80] versus 2.17 mg/L [IQR, 1.15–5.06] at BL; P =0.002). Interleukin-6 was significantly increased at 45 minutes (2.59 pg/mL [IQR, 1.69–5.0] versus 1.5 pg/mL [IQR, 1.5–2.21] at BL; P =0.002), and soluble CD40 ligand was significantly decreased at 60 minutes (801.6 pg/mL [IQR, 675.0–1653.5] versus 1750.0 pg/mL [IQR, 1151.0–2783.0] at BL; P =0.016). Elevated counts of polymorphonuclear neutrophils were detectable at 15 minutes, with a significant increase at 2 hours (6415 cells/μL [IQR, 5288–7827] versus 4697 cells/μL [IQR, 2892–5620] at BL; P =0.004). Significant monocytosis was observed at 24 hours (729 cells/μL [IQR, 584–1344] versus 523 cells/μL [IQR, 369–701] at BL; P =0.015).

Conclusions:

Interleukin-6 and neutrophil granulocytes showed a continuous rise at all prespecified time points after induction of MI. Our results provide valuable additional evidence of the diagnostic value of inflammatory biomarkers in the setting of early acute MI.

Relationship between periodontal status and C-reactive protein and interleuckin-6 levels among atherosclerotic patients in Bandar Abbas, Iran in 2014

BACKGROUND

Recent studies have reported an association between periodontitis and cardiovascular diseases. Atherosclerosis is also a risk factor for cardiovascular diseases. IL-6 and CRP are important inflammatory markers that are important because they have been shown to be higher when a patient has periodontitis, and they are related to atherosclerosis. The aim of this study was to assess the relationship between periodontitis and CRP and IL-6 in atherosclerotic patients.

METHODS

The study population in this case control study was atherosclerotic patients in Bandar Abbas, Iran in 2014. The participants included 30 individuals with periodontal diseases and 30 individuals without periodontal diseases, and they were allocated into two groups according to probe depth (PD) and clinical attachment loss (CAL). Inflammatory markers, including CRP and IL-6 were measured in the two groups. The data were analyzed using IBM SPSS 21 statistical software. Descriptive statistics, chi-squared, independent samples t-test, and Mann-Whitney tests were used to analyze the data.

RESULTS

Individuals with abnormal CRP had significantly higher PD and CAL than individuals with normal CRP (P<0.001). Although PD was not significantly different in individuals with normal and abnormal IL-6 (P=0.124), CAL was significantly higher in individuals with abnormal IL-6 than in the other individuals (P=0.005).

CONCLUSION

The results of this study showed that CRP and IL-6 are associated with periodontal diseases in atherosclerotic patients. Treatment of periodontal diseases is recommended in atherosclerotic patients.

Effects of established hypolipidemic drugs on HDL concentration, subclass distribution, and function

The knowledge of an inverse relationship between plasma high-density lipoprotein cholesterol (HDL-C) concentrations and rates of cardiovascular disease has led to the concept that increasing plasma HDL-C levels would be protective against cardiovascular events. Therapeutic interventions presently available to correct the plasma lipid profile have not been designed to specifically act on HDL, but have modest to moderate effects on plasma HDL-C concentrations. Statins, the first-line lipid-lowering drug therapy in primary and secondary cardiovascular prevention, have quite modest effects on plasma HDL-C concentrations (2-10%). Fibrates, primarily used to reduce plasma triglyceride levels, also moderately increase HDL-C levels (5-15%). Niacin is the most potent available drug in increasing HDL-C levels (up to 30%), but its use is limited by side effects, especially flushing.The present chapter reviews the effects of established hypolipidemic drugs (statins, fibrates, and niacin) on plasma HDL-C levels and HDL subclass distribution, and on HDL functions, including cholesterol efflux capacity, endothelial protection, and antioxidant properties.

Atorvastatin combined with poly-unsaturated fatty acid confers better improvement of dyslipidemia and endothelium function

Background

Atorvastatin and poly-unsaturated fatty acid (PUFA) are beneficial for lipid-modification, whether atorvastatin plus PUFA could confer better improvement on dyslipidemia and endothelium function is unknown.

Methods

Dyslipidemia model of 40 rabbits were produced with atherogenic diet, and thereafter saline, atorvastatin, PUFA, or atorvastatin plus PUFA were prescribed for 1 week. Ten rabbits given normal diet served as the sham group. Parameters of interest including lipid profiles, endothelium function (nitric oxide, NO) and activation (solution vascular-cellular adhesion molecule, (sVCAM) and intracellular adhesion molecule, (sICAM)), markers of inflammation (C-reactive protein, CRP) and oxidation (malondialdehyde, MDA) were compared among groups.

Results

There was no significant difference of parameters among groups at the initial. With 1 week of atherogenic diet administration, serum levels of lipid profiles, sVCAM and sICAM, CRP and MDA were significantly increased, accompanying with profound NO reduction, as compared to the sham group. After 1 week of medical intervention, as compared to the control group (saline administration), dyslipidemia and endothelium function were modestly improved with either atorvastatin or PUFA therapy. Nevertheless, these efficacies were further and significantly enhanced with combined therapy when compared to the control group (p < 0.005), suggesting that there was synergistic effects of atorvastatin and PUFA co-therapy in rabbits with dyslipidemia.

Conclusion

Atorvastatin plus PUFA therapy could immediately contribute to better improvement of lipid-modification and endothelium function in rabbits with dyslipidemia.

Carotid atherosclerotic plaque stenosis: the stabilizing role of statins

BACKGROUND

Both pathophysiology and treatments of carotid atherosclerotic plaque stenosis represent two interesting fields of strong scientific investigation. Among different drugs, safety and efficacy of statin treatment have been widely investigated and proved.

MATERIALS AND METHODS

This narrative review is based on the material searched for and obtained via MEDLINE and PubMed up to March 2014. The search terms we used were: 'carotid plaque, intima-media thickness, plaque burden, stroke' in combination with 'statins, pleiotropic effects, HMG-CoA reductase inhibitors, lipid-lowering drugs'.

RESULTS

Carotid stenosis represents both a useful parameter to evaluate the atherosclerotic burden and a target for therapeutic (medical or surgical) decisions. Statins do not only improve the lipid profile, but also induce some 'pleiotropic' anti-inflammatory activities that contribute to carotid plaque stabilization. Statin-mediated protective activities are under active investigation at subclinical levels with the potential benefit of advanced imaging techniques. However, considering that some new techniques (excepted B-mode ultrasound) remain quite expensive, they can have for the moment an important role in research, but not in the clinical field.

CONCLUSIONS

Emerging evidence suggests that statin treatment improves carotid atherosclerosis, inducing a partial regression of plaque inflammation and size. Innovative imaging techniques might also ameliorate the identification of patients at high risk of cerebrovascular and coronary events, for which preventive statin treatments might be essential.

Synergistic effects of atorvastatin and rosiglitazone on endothelium protection in rats with dyslipidemia

Background

Endothelial dysfunction is implicated in the initiation and progression of atherosclerosis. Whether atorvastatin combined with rosiglitazone has synergistic effects on endothelial function improvement in the setting of dyslipidemia is unknown.

Methods

Dyslipidemia rat model was produced with high-fat and high-cholesterol diet administration. Thereafter, atorvastatin, rosiglitazone or atorvastatin combined with rosiglitazone were prescribed for 2 weeks. At baseline, 6 weeks of dyslipidemia model production, and 2 weeks of medical intervention, fasting blood was drawn for parameters of interest evaluation. At the end, myocardium was used for 15-deoxy-delta-12,14-PGJ₂ (15-d-PGJ₂) assessment.

Results

Initially, there was no significant difference of parameters between sham and dyslipidemia groups. With 6 weeks’ high-fat and high-cholesterol diet administration, as compared to sham group, serum levels of triglyceride (TG), total cholesterol (TC) and low density lipoprotein-cholesterol (LDL-C) were significantly increased. Additionally, nitric oxide (NO) production was reduced and serum levels of malondialdehyde (MDA), C-reactive protein (CRP) and asymmetric dimethylarginine (ADMA) were profoundly elevated in dyslipidemia group. After 2 weeks’ medical intervention, lipid profile was slightly improved in atorvastatin and combined groups as compared to control group. Nevertheless, in comparison to control group, NO production was profoundly increased and serum levels of MDA, CRP and ADMA were significantly decreased with atorvastatin or rosiglitazone therapy. 15-d-PGJ₂ expression of myocardium was also significantly elevated with atorvastatin or rosiglitazone treatment. Notably, these effects were further enhanced with combined therapy, suggesting that atorvastatin and rosiglitazone had synergistic effects on endothelial protection, and inflammation and oxidation amelioration.

Conclusion

Atorvastatin and rosiglitazone therapy had synergistic effects on endothelium protection as well as amelioration of oxidative stress and inflammatory reaction in rats with dyslipidemia.

Inflammatory co-morbidities in HIV+ individuals: learning lessons from healthy ageing

Increased life expectancy due to improved efficacy of cART has uncovered an increased risk of age-related morbidities in HIV+ individuals and catalyzed significant research into mechanisms driving these diseases. HIV infection increases the risk of non-communicable diseases common in the aged, including cardiovascular disease, neurocognitive decline, non-AIDS malignancies, osteoporosis, and frailty. These observations suggest that HIV accelerates immunological ageing, and there are many immunological similarities with the aged, including shortened telomeres, accumulation of senescent T cells and altered monocyte phenotype/function. However, the most critical similarity between HIV+ individuals and the elderly, which most likely underpins the heightened risk of non-communicable diseases, is chronic inflammation and associated immune activation. Here, we review the similarities between HIV+ individuals and the aged regarding the pathogenesis of inflammatory diseases, the current evidence for mechanisms driving these processes and discuss current and potential therapeutic strategies for addressing inflammatory co-morbidity in HIV+ infection.

Statin-induced impairment of monocyte migration is gender-related

Statins, widely used for treatment of hypercholesterolemia, have been demonstrated to exert pleiotropic beneficial effects independently of their cholesterol-lowering action, such as anti-inflammatory activity. A gender disparity has been observed in their cholesterol lowering activity as well as in response to these "off label" effects. Monocytes play a central role in atherosclerotic disease and, more in general, in inflammatory responses, through their chemotactic function and cytokine production. On these bases, in the present work, we examined the effect of statins on homeostasis and migration properties of freshly isolated monocytes from male and female healthy donors. Two prototypic natural and synthetic statins with different polarity, that is, type 1 and type 2 statins, have been considered: simvastatin and atorvastatin. Freshly isolated monocytes from peripheral blood of male and female healthy donors were treated with these drugs in the absence or presence of lipopolysaccharide (LPS) stimulation. Results obtained indicated that the polar statin efficiently inhibited chemotaxis of monocytes more than the apolar statin and that this effect was more significantly induced in cells from females than in cells from males. Dissecting the mechanisms involved, we found that these results could mainly be due to differential effects on: (i) the release of key cytokines, for example, MCP-1 and TNF-α; (ii) the maintenance of the redox homeostasis; (iii) a target activity on microfilament network integrity and function. All in all these results could suggest a reappraisal of "off-label" effects of statins taking into account either their chemical structure, that is, molecular polarity, or the gender issue.

Anti-inflammatory and cholesterol-reducing properties of apolipoprotein mimetics: a review

Reduced levels of HDL cholesterol (HDL-C) are a strong independent predictor of coronary artery disease (CAD) risk. The major anti-atherogenic function of HDL is to mediate reverse cholesterol transport. This response is highly dependent on apoA-I and apoE, protein components of HDL. Randomized clinical trials have assessed effects of several classes of drugs on plasma cholesterol levels in CAD patients. Agents including cholestyramine, fibrates, niacin, and statins significantly lower LDL cholesterol (LDL-C) and induce modest increases in HDL-C, but tolerance issues and undesirable side effects are common. Additionally, residual risk may be present in patients with persistently low HDL-C and other complications despite a reduction in LDL-C. These observations have fueled interest in the development of new pharmacotherapies that positively impact circulating lipoproteins. The goal of this review is to discuss the therapeutic potential of synthetic apolipoprotein mimetic peptides. These include apoA-I mimetic peptides that have undergone initial clinical assessment. We also discuss newer apoE mimetics that mediate the clearance of atherogenic lipids from the circulation and possess anti-inflammatory properties. One of these (AEM-28) has recently been given orphan drug status and is undergoing clinical trials.

Oral lovastatin attenuates airway inflammation and mucus secretion in ovalbumin-induced murine model of asthma

PURPOSE

Lovastatin is an effective inhibitor of cholesterol synthesis. A previous study demonstrated that lovastatin can also suppress airway hyperresponsiveness (AHR) in murine model of asthma. We aimed to investigate the effect of lovastatin on mucus secretion and inflammation-associated gene expression in the lungs of murine model of asthma.

METHODS

Female BALB/c mice were sensitized and challenged with ovalbumin (OVA) by intraperitoneal injection, and orally administered lovastatin from days 14 to 27 post-injection. Gene expression in lung tissues was analyzed using real-time polymerase chain reaction. AHR and goblet cell hyperplasia were also examined. BEAS-2B human bronchial epithelial cells were used to evaluate the effect of lovastatin on the expression of cell adhesion molecules, chemokines, and proinflammatory cytokines in vitro.

RESULTS

We showed that lovastatin inhibits the expression of Th2-associated genes, including eotaxins and adhesion molecules, in the lungs of murine model of asthma. Mucin 5AC expression, eosinophil infiltration and goblet cell hyperplasia were significantly decreased in the lung tissue of murine model of asthma treated with lovastatin. Furthermore, lovastatin inhibited AHR and expression of Th2-associated cytokines in bronchoalveolar lavage fluid. However, a high dose (40 mg/kg) of lovastatin was required to decrease specific IgE to OVA levels in serum, and suppress the expression of Th2-associated cytokines in splenocytes. Activated BEAS-2B cells treated with lovastatin exhibited reduced IL-6, eotaxins (CCL11 and CCL24), and intercellular adhesion molecule-1 protein expression. Consistent with this, lovastatin also suppressed the ability of HL-60 cells to adhere to inflammatory BEAS-2B cells.

CONCLUSIONS

These data suggest that lovastatin suppresses mucus secretion and airway inflammation by inhibiting the production of eotaxins and Th2 cytokines in murine model of asthma.

Statins in pregnancy

PURPOSE OF REVIEW

The use of statins in women of reproductive age to prevent adverse cardiovascular events is on the rise. This is attributed to an increase in metabolic risk factors such as obesity, raised lipids, diabetes and high blood pressure. Statins are contraindicated in pregnancy because of the perceived increased risk of congenital abnormalities to the foetus. We evaluated the evidence, including published reviews and primary studies, on the safety of statins in pregnancy and assessed the benefits to the mother.

RECENT FINDINGS

The risk of major congenital abnormalities from exposure to statins in pregnancy is similar to the background risk of the population. No specific pattern of abnormalities was observed. Existing studies are small with limitations in their quality. Preliminary evidence suggests a beneficial role for statins in preventing preeclampsia.

SUMMARY

There is no evidence to demonstrate that use of statins in pregnancy increases the risk of foetal abnormalities. The findings were limited by the poor quality and reporting of existing studies.

Statin treatment reduces the risk of hepatocellular carcinoma but not colon cancer-results from a nationwide case-control study in Sweden

BACKGROUND

Several studies have indicated that statins may have anticarcinogenic effects. The aim of the present study was to investigate if statin treatment was associated with a reduced risk of hepatocellular carcinoma (HCC) or colon cancer.

METHODS

A nationwide case-control study was carried out in which all cases of HCC and colon cancer in the Swedish population above 40 years of age between 1 July 2006 and 31 December 2010 were identified in the Swedish Cancer Register. For every case, five controls were selected and matched on age and sex. Data on statin use was extracted from the Swedish Prescribed Drug Register. We estimated risks using conditional logistic regression and adjusted for educational level, concomitant medications and comorbidity.

RESULTS

Identified were 3994 cases of HCC and matched with 19.970 controls, and 21.143 cases of colon cancer were identified and matched with 105.715 controls. In the adjusted analysis, the odds ratio (OR) for HCC among statin users was 0.88 (95% confidence interval (CI) 0.81-0.96), and the OR for colon cancer was 1.04 (95%CI 1.00-1.08) compared with non-users.

CONCLUSION

Statin use was associated with a modest decreased risk of HCC but did not influence the risk of colon cancer. Future randomized placebo-controlled trials in HCC high-risk patients are warranted to further investigate the possible prophylactic effect of statins in HCC.

Metformin enhances nitric oxide production and diminishes Rho kinase activity in rats with hyperlipidemia

BACKGROUND

Rho kinase over-activation is associated with nitric oxide (NO) reduction and atherosclerosis. Metformin is favorable for endothelial function improvement and cardiovascular outcomes. Whether cardio-protective effect of metformin is associated with Rho kinase activity is unknown.

METHODS

Hyperlipidemia model of rats were established accordingly. Thereafter, medical interventions in terms of atorvastatin, metformin or combined therapy were administered for 4 weeks. Laboratory parameters were compared among each groups at initial, 6 weeks of high-fat and high-cholesterol diet administration, and 4 weeks of medical intervention. Lineal regression analyses were performed.

RESULTS

No significant difference of laboratory parameters was observed initially. Six weeks of high-fat and high-cholesterol diet administration, serum levels of cholesterol, C-reactive protein (CRP) level, and Rho kinase activity were significantly increased while NO production was concomitantly reduced in comparison to the sham group. After 4 weeks of medical intervention, CRP level and Rho kinase activity were profoundly diminished while NO production was significantly enhanced in the atorvastatin and metformin groups, and these benefits were further enhanced with combined therapy. Lineal regression analyses showed that Rho kinase activity was negatively correlated with NO production but positively correlated with CRP level.

CONCLUSION

In rats with hyperlipidemia, metformin and atorvastatin therapy is favorable for NO production and CRP reduction, which might be associated with Rho kinase activity decrease.

Statins in chronic kidney disease and kidney transplantation

HMG-CoA reductase inhibitors (statins) have been shown to improve cardiovascular (CV) outcomes in the general population as well as in patients with cardiovascular disease (CVD). Statins' beneficial effects have been attributed to both cholesterol-lowering and cholesterol-independent "pleiotropic" properties. By their pleiotropic effects statins have been shown to reduce inflammation, alleviate oxidative stress, modify the immunologic responses, improve endothelial function and suppress platelet aggregation. Patients with chronic kidney disease (CKD) exhibit an enormous increase in CVD rates even from early CKD stages. As considerable differences exist in dyslipidemia characteristics and the pathogenesis of CVD in CKD, statins' CV benefits in CKD patients (including those with a kidney graft) should not be considered unequivocal. Indeed, accumulating clinical evidence suggests that statins exert diverse effects on dialysis and non-dialysis CKD patients. Therefore, it seems that statins improve CV outcomes in non-dialysis patients whereas exert little (if any) benefit in the dialysis population. It has also been proposed that dyslipidemia might play a causative role or even accelerate renal injury. Moreover, ample experimental evidence suggests that statins ameliorate renal damage. However, a high quality randomized controlled trial (RCT) and metaanalyses do not support a beneficial role of statins in renal outcomes in terms of proteinuria reduction or retardation of glomerular filtration rate (GFR) decline.

Atorvastatin increases lipopolysaccharide-induced expression of tumour necrosis factor-α-induced protein 8-like 2 in RAW264.7 cells

RAW264.7 cells are one of the major sources of productive inflammatory biomediators, including tumour necrosis factor-α (TNF-α) and interleukin (IL)-6. TNF-α-induced protein 8-like 2 (TIPE2) is an essential negative regulator of Toll-like and T-cell receptors, and the selective expression in the immune system prevents hyper-responsiveness and maintains immune homeostasis. The aim of the present study was to investigate whether atorvastatin upregulates the expression of TIPE2 and further regulates the inflammatory response and oxidation emergency response in RAW264.7 cells. RAW264.7 cells were incubated in Dulbecco’s modified Eagle’s medium containing lipopolysaccharide (LPS) in the presence or absence of atorvastatin. Following incubation, the medium was collected and the levels of TNF-α and IL-6 were measured using an enzyme-linked immunosorbent assay. The cells were harvested, and the mRNA and protein expression levels of TIPE2, macrophage migration inhibitory factor (MIF), IκB and nuclear factor (NF-κB)-κB were analysed using quantitative polymerase chain reaction and western blotting analysis, respectively, the expression of NOS, COX-2 and HO-1 protein were essayed by western blotting analysis, NO and ROS activities were determined. The results revealed that LPS increased the mRNA and protein expression levels of TIPE2, MIF and NF-κB, as well as the production of IL-6 and TNF-α, in a dose and time dependent manner in RAW264.7 cells. Meanwhile, LPS enhanced the expression of NOS and COX-2 protein, blocked HO-1 protein expression, increased NO and PGE2 production and ROS activity in a dose dependent manner in RAW264.7 cells. Atorvastatin significantly increased LPS induced expression of TIPE2, downregulated the expression of NOS, COX-2, MIF and NF-κB and the production of PGE2, NO, IL-6 and TNF-α in a time and dose dependent manner, and increased HO-1 protein expression, reduced ROS production in a dose dependent manner. The observations indicated that atorvastatin upregulated LPS induced expression of TIPE2 and consequently inhibited MIF, NF-κB, NOS and COX-2 expression and the production of NO, PGE2, TNF-α and IL-6, increased HO-1 expression, and inhibited ROS activity in cultured RAW264.7 cells.

Statin use and risk of delirium in the critically ill

RATIONALE

Delirium is common in intensive care unit (ICU) patients and is a predictor of worse outcomes and neuroinflammation is a possible mechanism. The antiinflammatory actions of statins may reduce delirium.

OBJECTIVES

To determine whether critically ill patients receiving statin therapy had a reduced risk of delirium than those not on statins.

METHODS

A prospective cohort analysis of data from consecutive ICU patients admitted to a UK mixed medical and surgical critical care unit between August 2011 and February 2012; the Confusion Assessment Method for ICU was used to determine the days each patient was assessed as being free of delirium during ICU admission.

MEASUREMENTS AND MAIN RESULTS

Delirium-free days, daily administration of statins, and serum C-reactive protein (CRP) were recorded. Four hundred and seventy consecutive critical care patients were followed, of whom 151 patients received statins. Using random-effects multivariable logistic regression, statin administration the previous evening was associated with the patient being assessed as free of delirium (odds ratio, 2.28; confidence interval, 1.01-5.13; P < 0.05) and with lower CRP (β = -0.52; P < 0.01) the following day. When the association between statin and being assessed as free of delirium was controlled for CRP, the effect size became nonsignificant (odds ratio, 1.56; confidence interval, 0.64-3.79; P = 0.32).

CONCLUSIONS

Ongoing statin therapy is associated with a lower daily risk of delirium in critically ill patients. An ongoing clinical trial, informed by this study, is investigating if statins are a potential therapy for delirium in the critically ill.

3-Hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor (statin)-induced 28-kDa interleukin-1β interferes with mature IL-1β signaling

Multiple clinical trials have shown that the 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors known as statins have anti-inflammatory effects. However, the underlying molecular mechanism remains unclear. The proinflammatory cytokine interleukin-1β (IL-1β) is synthesized as a non-active precursor. The 31-kDa pro-IL-1β is processed into the 17-kDa active form by caspase-1-activating inflammasomes. Here, we report a novel signaling pathway induced by statins, which leads to processing of pro-IL-1β into an intermediate 28-kDa form. This statin-induced IL-1β processing is independent of caspase-1- activating inflammasomes. The 28-kDa form of IL-1β cannot activate interleukin-1 receptor-1 (IL1R1) to signal inflammatory responses. Instead, it interferes with mature IL-1β signaling through IL-1R1 and therefore may dampen inflammatory responses initiated by mature IL-1β. These results may provide new clues to explain the anti-inflammatory effects of statins.

ERK5 activation in macrophages promotes efferocytosis and inhibits atherosclerosis

BACKGROUND

Efferocytosis is a process by which dead and dying cells are removed by phagocytic cells. Efferocytosis by macrophages is thought to curb the progression of atherosclerosis, but the mechanistic insight of this process is lacking.

METHODS AND RESULTS

When macrophages were fed apoptotic cells or treated with pitavastatin in vitro, efferocytosis-related signaling and phagocytic capacity were upregulated in an ERK5 activity-dependent manner. Macrophages isolated from macrophage-specific ERK5-null mice exhibited reduced efferocytosis and levels of gene and protein expression of efferocytosis-related molecules. When these mice were crossed with low-density lipoprotein receptor(-/-) mice and fed a high-cholesterol diet, atherosclerotic plaque formation was accelerated, and the plaques had more advanced and vulnerable morphology.

CONCLUSIONS

Our results demonstrate that ERK5, which is robustly activated by statins, is a hub molecule that upregulates macrophage efferocytosis, thereby suppressing atherosclerotic plaque formation. Molecules that upregulate ERK5 and its signaling in macrophages may be good drug targets for suppressing cardiovascular diseases.

Stress triggers coronary mast cells leading to cardiac events

OBJECTIVE

Stress precipitates and worsens not only asthma and atopic dermatitis but also acute coronary syndromes (ACSs), which are associated with coronary inflammation. Evidence linking stress to ACS was reviewed and indicated that activation of coronary mast cells (MCs) by stress, through corticotropin-releasing hormone (CRH) and other neuropeptides, contributes to coronary inflammation and coronary artery disease.

DATA SOURCES

PubMed was searched (2005-2013) for articles using the following keywords: allergies, anaphylaxis, anxiety, coronary arteries, coronary artery disease, C-reactive protein, cytokines, chymase, histamine, hypersensitivity, interleukin-6 (IL-6), inflammation, mast cells, myocardial ischemia, niacin, platelet-activating factor, rupture, spasm, statins, stress, treatment, tryptase, and uroctortin.

STUDY SELECTIONS

Articles were selected based on their relevance to how stress affects ACS and how it activates coronary MCs, leading to coronary hypersensitivity, inflammation, and coronary artery disease.

RESULTS

Stress can precipitate allergies and ACS. Stress stimulates MCs through the activation of high-affinity surface receptors for CRH, leading to a CRH-dependent increase in serum IL-6. Moreover, neurotensin secreted with CRH from peripheral nerves augments the effect of CRH and stimulates cardiac MCs to release IL-6, which is elevated in ACS and is an independent risk factor for myocardial ischemia. MCs also secrete CRH and uroctortin, which induces IL-6 release from cardiomyocytes. The presence of atherosclerosis increases the risk of cardiac MC activation owing to the stimulatory effect of lipoproteins and adipocytokines. Conditions such as Kounis syndrome, mastocytosis, and myalgic encephalopathy/chronic fatigue syndrome are particularly prone to coronary hypersensitivity reactions.

CONCLUSION

Inhibition of cardiac MCs may be a novel treatment approach.