Inflammation, immunity, and HMG-CoA reductase inhibitors: statins as antiinflammatory agents?

Effect of rosuvastatin on concentrations of plasma lipids, urine and plasma oxidative stress markers, and plasma high-sensitivity C-reactive protein in hypercholesterolemic patients with and without type 2 diabetes mellitus: A 12-week, open-label, pilot study

BACKGROUND

Oxidative stress and inflammation of the arterial wall are now recognized as important factors in the progression of atherosclerosis. C-reactive protein (CRP) has been defined as a sensitive but not specific marker of inflammation. Statin therapy has been reported to decrease plasma high-sensitivity CRP (hs-CRP) concentration in hypercholesterolemic patients.

OBJECTIVE

The aim of this study was to examine the effect of rosuvastatin on concentrations of plasma lipids, urine and plasma oxidative stress markers, and plasma hs-CRP in hypercholesterolemic patients with and without type 2 diabetes mellitus.

METHODS

Patients with hypercholesterolemia with and without type 2 diabetes mellitus were enrolled in this pilot study after written informed consent was given. At baseline and after 12 weeks of open-label treatment with rosuvastatin 2.5 mg/d, concentrations of plasma lipids, urine and plasma oxidative stress markers, and plasma hs-CRP were measured. Urine 8-iso-prostaglandin F2α (8-iso-PGF2α) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations were also measured to asess whole-body oxidative stress. Plasma free-radical generation was estimated using a total reactive oxygen species (TROS) assay system. Adverse effects were assessed at each study visit (4-week intervals) through patient interviews and laboratory testing.

RESULTS

Thirty-five patients were enrolled with 1 dropping out prior to study completion; therefore, 34 patients (19 women, 15 men; mean [SE] age, 55.4 [13.6] years; range, 30-78 years) completed the study. Compared with baseline, significant decreases were found in serum concentrations of total cholesterol (TC) (252.3 [39.3] vs 187.8 [30.1] mg/dL; P < 0.001; Δ = 24.5%), LDL-C (162.0 [44.3] vs 98.5 [31.9] mg/dL; P < 0.001; Δ = 38.7%), and triglycerides (TG) (157.2 [93.6] vs 124.4 [69.9] mg/dL; P < 0.05; Δ = 11.7%) after 12 weeks of treatment with rosuvastatin. Serum HDL-C concentration did not change significantly from baseline (59.7 [20.5] vs 63.7 [19.3] mg/dL; Δ = 9.4%). The plasma LDL-C/HDL-C ratio decreased significantly after rosuvastatin treatment (3.03 [1.33] vs 1.72 [0.83]; P < 0.001; Δ = 43.2%). Compared with baseline, significant decreases were observed in urine concentrations of the oxidative stress markers after 12 weeks of rosuvastatin treatment: 8-iso-PGF2α (342.8 [154.3] vs 300.6 [101.2] pg/mg; P < 0.05) and 8-OHdG (11.1 [4.53] vs 8.1 [2.7] ng/mg; P < 0.01). TROS decreased significantly (182.3 [29.0] vs 157.6 [17.3] U; P < 0.001), and plasma hs-CRP concentration also decreased significantly (0.107 [0.100] vs 0.054 [0.033] mg/dL; P < 0.05). When the patients' results were assessed according to the presence or absence of type 2 diabetes mellitus, urine 8-iso-PGF2α concentration was significantly decreased from baseline only in the nondiabetic group. No adverse events were reported or observed during the course of the study.

CONCLUSION

Rosuvastatin treatment was associated with significant reductions in plasma concentrations of TC, LDL-C, and TG, urine and plasma oxidative stress markers, and plasma hs-CRP in these hypercholesterolemic patients.

The impact of ezetimibe on endothelial function and other markers of cardiovascular risk

OBJECTIVE

To review the published literature characterizing the impact of ezetimibe-containing lipid-lowering regimens on endothelial function and other markers of cardiovascular risk and discuss the potential relevance of these effects to the clinical benefit of ezetimibe.

DATA SOURCES

A MEDLINE search (2000-August 2009) was completed using the key words ezetimibe, statins, endothelial function, flow-mediated dilation, pleiotropic, and inflammation to identify relevant literature. Bibliographies of identified literature were reviewed for additional references.

STUDY SELECTION AND DATA EXTRACTION

All clinical studies published in English that evaluated the effect of ezetimibe on ancillary endpoints of cardiovascular disease risk, including endothelial function, inflammation, thrombosis, and oxidative stress, were evaluated.

DATA SYNTHESIS

Recent studies in patients with coronary artery disease (CAD), heart failure, and hypercholesterolemia have demonstrated that treatment with ezetimibe for 4-12 weeks elicits no improvement of endothelial function or other measures of cardiovascular disease risk. In contrast, other studies have reported that ezetimibe improves endothelial function in certain patient populations, including those with rheumatoid arthritis, CAD with type 2 diabetes, and metabolic syndrome. However, the statin monotherapy comparator groups in these studies that yielded equivalent reductions in cholesterol were superior, or at least equivalent to, ezetimibe-containing regimens in the improvement of these ancillary endpoints.

CONCLUSIONS

Overall, the evidence to date suggests that administration of ezetimibe, either as monotherapy or in combination with a statin, exerts minimal beneficial effects on endothelial function and other ancillary measures of cardiovascular disease risk beyond those conferred by its cholesterol-lowering effects. Studies with larger sample sizes and follow-up beyond 12 weeks remain necessary to further define the impact of ezetimibe on the processes integral to the pathogenesis and progression of cardiovascular disease.

Simvastatin inhibits airway hyperreactivity: implications for the mevalonate pathway and beyond

RATIONALE

Statin use has been linked to improved lung health in asthma and chronic obstructive pulmonary disease. We hypothesize that statins inhibit allergic airway inflammation and reduce airway hyperreactivity via a mevalonate-dependent mechanism.

OBJECTIVES

To determine whether simvastatin attenuates airway inflammation and improves lung physiology by mevalonate pathway inhibition.

METHODS

BALB/c mice were sensitized to ovalbumin over 4 weeks and exposed to 1% ovalbumin aerosol over 2 weeks. Simvastatin (40 mg/kg) or simvastatin plus mevalonate (20 mg/kg) was injected intraperitoneally before each ovalbumin exposure.

MEASUREMENTS AND MAIN RESULTS

Simvastatin reduced total lung lavage leukocytes, eosinophils, and macrophages (P < 0.05) in the ovalbumin-exposed mice. Cotreatment with mevalonate, in addition to simvastatin, reversed the antiinflammatory effects seen with simvastatin alone (P < 0.05). Lung lavage IL-4, IL-13, and tumor necrosis factor-alpha levels were all reduced by treatment with simvastatin (P < 0.05). Simvastatin treatment before methacholine bronchial challenge increased lung compliance and reduced airway hyperreactivity (P = 0.0001).

CONCLUSIONS

Simvastatin attenuates allergic airway inflammation, inhibits key helper T cell type 1 and 2 chemokines, and improves lung physiology in a mouse model of asthma. The mevalonate pathway appears to modulate allergic airway inflammation, while the beneficial effects of simvastatin on lung compliance and airway hyperreactivity may be independent of the mevalonate pathway. Simvastatin and similar agents that modulate the mevalonate pathway may prove to be treatments for inflammatory airway diseases, such as asthma.

Increased expression and activity of MMP-9 in C-reactive protein- induced human THP-1 mononuclear cells is related to activation of nuclear factor kappa-B

The relation between the expression and activity of MMP-9 in C-reactive protein (CRP)-induced human THP-1 mononuclear cells and the activation of nuclear factor kappa-B (NF-kappaB) was studied to investigate the possible role of CRP in plaque destabilization. Human THP-1 cells were incubated in the presence of CRP at 0 (control group), 25, 50 and 100 microg/mL (CRP groups) for 24 h. In PDTC (a specific NF-kappaB inhibitor) group, the cells were pre-treated with PDTC at 10 micromol/L and then with 100 microg/mL CRP. The conditioned media (CM) and human THP-1 cells in different groups were harvested. MMP-9 expression in CM and human THP-1 cells was measured by ELISA and Western blotting. MMP-9 activity was assessed by fluorogenic substrates. The expression of NF-kappaB inhibitor alpha (IkappaB-alpha) and NF-kappaB P(65) was detected by Western blotting and ELISA respectively. The results showed that CRP increased the expression and activity of MMP-9 in a dose-dependent manner in the human THP-1 cells. Western blotting revealed that IkappaB-alpha expression was decreased in the cells with the concentrations of CRP and ELISA demonstrated that NF-kappaB P65 expression in the CRP-induced cells was increased. After pre-treatment of the cells with PDTC at 10 micromol/L, the decrease in IkappaB-alpha expression and the increase in NF-kappaB P(65) expression in the CRP-induced cells were inhibited, and the expression and activity of MMP-9 were lowered too. It is concluded that increased expression and activity of MMP-9 in CRP-induced human THP-1 cells may be associated with activation of NF-kappaB. Down-regulation of the expression and activity of MMP-9 may be a new treatment alternative for plaque stabilization by inhibiting the NF-kappaB activation.

Immunomodulation by statins: mechanisms and potential impact on autoimmune diseases

Statins are inhibitors of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) and they are the most effective agents for lowering cholesterol in clinical practice for the treatment of cardiovascular diseases. However, it has become clear that statins also have pleiotropic immunomodulatory effects in addition to their lipid-lowering properties. As a result, much attention has been focused on their potential as therapeutic agents for the treatment of inflammatory autoimmune diseases. In this review the effect of statins on the expression and function of a variety of immune-relevant molecules will be discussed alongside the underlying mechanisms that contribute to the immunomodulatory effects of statins.

Lipophilic but not hydrophilic statins selectively induce cell death in gynaecological cancers expressing high levels of HMGCoA reductase

Recent reports have suggested that statins induce cell death in certain epithelial cancers and that patients taking statins to reduce cholesterol levels possess lower cancer incidence. However, little is known about the mechanisms of action of different statins or the effects of these statins in gynaecological malignancies. The apoptotic potential of two lipophilic statins (lovastatin and simvastatin) and one hydrophilic statin (pravastatin) was assessed in cancer cell lines (ovarian, endometrial and cervical) and primary cultured cancerous and normal tissues. Cell viability was studied by MTS assays and apoptosis was confirmed by Western blotting of PARP and flow cytometry. The expressions of key apoptotic cascade proteins were analysed. Our results demonstrate that both lovastatin and simvastatin, but not pravastatin, selectively induced cell death in dose- and time-dependent manner in ovarian, endometrial and cervical cancers. Little or no toxicity was observed with any statin on normal cells. Lipophilic statins induced activation of caspase-8 and -9; BID cleavage, cytochrome C release and PARP cleavage. Statin-sensitive cancers expressed high levels of HMG-CoA reductase compared with resistant cultures. The effect of lipophilic statins was dependent on inhibition of enzymatic activity of HMG-CoA reductase since mevalonate pre-incubation almost completely abrogated the apoptotic effect. Moreover, the apoptotic effect involved the inhibition of synthesis of geranylgeranyl pyrophosphate rather than farnesyl pyrophosphate. In conclusion, lipophilic but not hydrophilic statins induce cell death through activation of extrinsic and intrinsic apoptotic cascades in cancerous cells from the human female genital tract, which express high levels of HMG-CoA reductase. These results promote further investigation in the use of lipophilic statins as anticancer agents in gynaecological malignancies.

Macrophage inflammatory protein-1beta induced cell adhesion with increased intracellular reactive oxygen species

To investigate the role of macrophage inflammatory protein-1 beta (MIP-1beta) in the development of atherosclerosis, we designed an in vitro study to elucidate the mechanisms of monocyte-endothelium adhesion via intracellular reactive oxygen species (ROS). Angiotensin II (AngII) was used as a positive control. Furthermore, we examined the efficacy of MIP-1beta as a predictor of stroke and cardiovascular events in hypertensive patients. MIP-1beta or AngII stimulation significantly increased ROS production and adhesion of THP-1 cells to inflamed human umbilical vein endothelial cells. Cell adhesion and ROS production were inhibited in stimulated THP-1 cells by: inhibition of ROS signaling with N-acetylcysteine, diphenyleneiodonium, or PEG-Catalase; inhibition of PI3Kgamma with siRNA or LY294002; and by Rac1 siRNA. The MIP-1 beta or AngII stimulation did not increase surface expression of integrins, very late antigen 4 (VLA-4) and lymphocyte function-associated antigen 1 (LFA-1), but cell adhesion was reduced by using an antiVLA-4 or an antiLFA-1 antibody. Moreover, cell adhesion and ROS production stimulated with MIP-1beta or AngII were completely inhibited by fluvastatin. In our clinical study, patients with the highest quartile of MIP-1beta showed a higher risk of stroke and cardiovascular events by a Cox proportional-hazards model. In conclusion, MIP-1beta directly induced cell adhesion to endothelial cells through oxidative stress via PI3k-Rac1 cascades. Serum MIP-1beta level might be a useful predictor for cerebro-cardiovascular events in hypertensive patients.

CONDENSED ABSTRACT

We designed an in vitro investigation to examine the role of MIP-1beta on the development of atherosclerosis, including cell adhesion involving CAMs and ROS production, compared with angiotensin II. Furthermore, we investigated the prognostic impact of MIP-1beta on stroke and cardiovascular events in hypertensive patients in a small cohort study.

Myeloid cells in atherosclerosis: initiators and decision shapers

Chronic inflammation is the underlying pathophysiological mechanism of atherosclerosis. Prominent suspects being involved in atherosclerosis are lymphocytes, platelets, and endothelial cells. However, recent advances suggest a potent role for myeloid leukocytes, specifically monocyte subsets, polymorphonuclear leukocytes, and mast cells. These three cell types are not just rapidly recruited or already reside in the vascular wall but also initiate and perpetuate core mechanisms in plaque formation and destabilization. Dendritic cell subsets as well as endothelial and smooth muscle progenitor cells may further emerge as important regulators of atheroprogression. To stimulate further investigations about the contribution of these myeloid cells, we highlight the current mechanistic understanding by which these cells tune atherosclerosis.

Connexins in vascular physiology and pathology

Cellular interaction in blood vessels is maintained by multiple communication pathways, including gap junctions. They consist of intercellular channels ensuring direct interaction between endothelial and smooth muscle cells and the synchronization of their behavior along the vascular wall. Gap-junction channels arise from the docking of two hemichannels or connexons, formed by the assembly of six connexins, and achieve direct cellular communication by allowing the transport of small metabolites, second messengers, and ions between two adjacent cells. Physiologic variations in connexin expression are observed along the vascular tree, with most common connexins being Cx37, Cx40, and Cx43. Changes in the level of expression of connexins have been correlated to the development of vascular disease, such as hypertension, atherosclerosis, or restenosis. Recent studies on connexin-deficient mice highlighted key roles of these communication pathways in the development of these pathologies and confirmed the need for targeted pharmacologic approaches for their prevention and treatment. The aim of this issue is to review the current knowledge on the implication of gap junctions in vascular function and most common cardiovascular diseases.

Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases

BACKGROUND

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation.

REVIEW

We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here.

CONCLUSION

Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.

Molecular and cellular mechanisms of the thrombotic complications of atherosclerosis

Clinicians have traditionally regarded the complications of atherosclerosis as a consequence of progressive arterial stenosis leading to critical narrowings that impede blood flow. Our contemporary understanding of the thrombotic complications of atherosclerosis has undergone a transformation based on a body of observations by pathologists and clinicians. In the late 1980s, clinicians had to confront the counterintuitive notion that plaques that cause acute myocardial infarction often do not produce high-grade stenoses (Smith, S. C., Jr. 1996. Risk-reduction therapy: the challenge to change. Circulation. 93: 2205-2211.). Observations from serial angiographic studies and on culprit lesions of acute myocardial infarction postthrombolysis highlighted this apparent paradox. These contrarian clinical findings prompted cardiologists to consider more carefully the findings of generations of pathologists that plaques that cause fatal coronary thrombi often result from a physical disruption of the atheromatous plaque that may not indeed cause critical arterial narrowing. This convergence of clinical and pathological observations highlighted the importance of understanding the mechanisms of disruption of plaques that can precipitate thromboses.

Multiple effects of HMG-CoA reductase inhibitors (statins) besides their lipid-lowering function

The paper by Sharyo et al. shows that statins reduce the severity in a model of renal-ischemia reperfusion injury and raises the therapeutic possibility of using statins as pharmacological intervention against acute kidney injury. This, together with previous studies, indicates that statins exert a wide spectrum of anti-inflammatory, immunomodulatory, and protective effects besides their lipid-lowering function.

Interferon gamma: a master regulator of atherosclerosis

Atherosclerosis is a chronic inflammatory disease that is characterized by the development of fibrotic plaques in the arterial wall. The disease exhibits a complex aetiology and its progression is influenced by a number of environmental and genetic risk factors. The cytokine interferon-gamma (IFN-gamma), a key regulator of immune function, is highly expressed in atherosclerotic lesions and has emerged as a significant factor in atherogenesis. Evidence from both mouse models of atherosclerosis and in vitro cell culture has suggested that the role of IFN-gamma is complex since both pro- and anti-atherogenic actions have been affiliated to it. This review will focus on evaluating the contribution of IFN-gamma to atherosclerosis and, in particular, how it regulates immune responses to the disease.

Pneumococcal vaccination and risk of myocardial infarction

BACKGROUND

Based on promising results from laboratory studies, we hypothesized that pneumococcal vaccination would protect patients from myocardial infarction.

METHODS

We conducted a hospital-based case-control study that included patients considered to be at risk of myocardial infarction. We used health databases to obtain hospital diagnoses and vaccination status. We compared patients who had been admitted for treatment of myocardial infarction with patients admitted to a surgical department in the same hospital for a reason other than myocardial infarction between 1997 and 2003.

RESULTS

We found a total of 43 209 patients who were at risk; of these, we matched 999 cases and 3996 controls according to age, sex and year of hospital admission. Cases were less likely than controls to have been vaccinated (adjusted odds ratio [OR] 0.53, 95% confidence interval [CI] 0.40-0.70). This putative protective role of the vaccine was not observed for patients who had received the vaccine up to 1 year before myocardial infarction (adjusted OR 0.85, 95% CI 0.54-1.33). In contrast, if vaccination had occurred 2 years or more before the hospital admission, the association was stronger (adjusted OR 0.33, 95% CI 0.20-0.46).

INTERPRETATION

Pneumococcal vaccination was associated with a decrease of more than 50% in the rate myocardial infarction 2 years after exposure. If confirmed, this association should generate interest in exploring the putative mechanisms and may offer another reason to promote pneumococcal vaccination.

The use of high-sensitivity assays for C-reactive protein in clinical practice

High-sensitivity assays that accurately measure levels of the inflammatory biomarker C-reactive protein have been proposed for use in assessments of risk for cardiovascular disease (CVD). A growing body of evidence supports recommendations for these tests in selected asymptomatic individuals deemed to be at intermediate risk of CVD according to traditional risk-factor assessments and who do not already warrant chronic treatment with aspirin and statin therapy. Data suggests that these high-sensitivity assays should be used in combination with measurements of LDL-cholesterol levels to assist risk stratification of selected patients for prevention of CVD.

Statins may reduce episodes of exacerbation and the requirement for intubation in patients with COPD: evidence from a retrospective cohort study

INTRODUCTION

Statins have diverse anti-inflammatory effects in addition to their lipid-lowering ability. This study assesses the rate of chronic obstructive pulmonary disease (COPD) exacerbation and intubations in patients taking statins.

METHODS

This is a retrospective cohort study of 185 patients with COPD exacerbation, with a 1-year follow-up. Outcomes examined were repeat hospitalisation and intubations for COPD exacerbation. Baseline characteristics for which the p-value was < or = 0.10 were considered as covariates for inclusion in a multivariate model.

RESULTS

The statin group had fewer episodes of exacerbation and required intubation fewer times than the subjects not receiving statins (p < 0.0001 for both outcomes). Unadjusted odds ratios (OR) for no statin use vs. statin use were 9.54 (95% CI: 4.54-20.02) for exacerbation and 10.47 (CI: 4.56-24.01) for intubation. The OR, adjusted for the use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (ORa), were 2.35 (CI: 1.01-5.50) for non-statin users exhibiting an exacerbation and 10.36 (CI: 2.77-38.76) for this group requiring intubation, compared with statin users. Similarly, ORa for long-acting beta(2) agonists as a covariate were 3.01 (CI: 1.46-6.10) for exacerbation and 8.89 (CI: 3.67-21.32) for intubation. Time to outcome during the observation period was reduced by statins with the hazard ratio (HR) for exacerbation of 0.19 (CI: 0.06-0.14); HR for statins reducing intubation was 0.14 (95% CI: 0.10-0.30).

CONCLUSIONS

These data suggest that the use of statins may be associated with lower incidence of both exacerbations and intubations in patients with COPD.

Association of anemia and erythropoiesis stimulating agents with inflammatory biomarkers in chronic kidney disease

Inflammatory cytokines are important predictors of cardiovascular mortality especially in patients with chronic kidney disease. Here we explored the relationship of anemia and epoetin treatment to inflammatory cytokine levels in patients with chronic kidney disease. One hundred non-dialysis patients with chronic kidney disease over 18 years of age were evenly split into anemic and non-anemic cohorts. Of the 50 anemic patients, 23 were receiving erythropoiesis stimulating agents treatments. Levels of tumor necrosis factor (TNF)-alpha were found to be significantly higher and serum albumin was significantly lower with trends towards higher interleukin (IL)-6 and IL-8 in anemic compared to non-anemic patients. Further analysis by multiple logistic regression found that anemic patients treated with erythropoiesis stimulating agents had significantly higher odds for the upper two quartiles for IL-6, IL-8 and TNF-alpha compared to non-anemic patients. Our study found that the anemia of chronic kidney disease was associated with up regulation of TNF-alpha, and possibly IL-6 and IL-8 along with increased levels of these proinflammatory cytokines in patients treated with epoetin.

Effects of a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, fluvastatin, on coronary spasm after withdrawal of calcium-channel blockers

OBJECTIVES

The purpose of this study was to determine whether a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) suppresses coronary spasm.

BACKGROUND

Coronary spasm is associated with endothelial dysfunction. Statins have been shown to improve endothelial function.

METHODS

This was a prospective, randomized, open-label, end point study. Sixty-four patients who had no significant organic coronary stenosis and in whom coronary spasm was induced by intracoronary injection of acetylcholine (ACh) were randomly assigned to fluvastatin 30 mg/day plus the conventional calcium-channel blocker (CCB) therapy (31 patients, statin group) or the conventional CCB therapy (33 patients, nonstatin group). After 6 months of treatment, the intracoronary injection of ACh was repeated and the coronary spasm was assessed.

RESULTS

Coronary spasm was suppressed in 16 of the 31 patients (51.5%, p < 0.0001) of the statin group and in 7 of the 33 patients (21.2%, p = 0.0110) of the nonstatin group after 6 months of treatment. Thus, the number of patients with ACh-induced coronary spasm was significantly reduced in the statin group as compared with the nonstatin group (51.6% vs. 21.2%, p = 0.0231) after 6 months of treatment.

CONCLUSIONS

The addition of fluvastatin 30 mg/day to the conventional CCB therapy for 6 months significantly reduced the number of patients with ACh-induced coronary spasm as compared with the conventional CCB therapy. Thus, a statin (fluvastatin) may possibly be a novel therapeutic drug for coronary spasm.

Statins restore ischemic limb blood flow in diabetic microangiopathy via eNOS/NO upregulation but not via PDGF-BB expression

3-Hydroxy-3-methyl-glutaryl CoA reductase inhibitors, or statins, have pleiotropic effects and can protect the vasculature in a manner independent of their lipid-lowering effect. The effectiveness of statins in reducing the risk of coronary events has been shown even in patients with diabetes, and their effects on diabetic complications have been reported. Using a model of severe hindlimb ischemia in streptozotocin-induced diabetic mice (STZ-DM), we investigated the effects and mechanisms of statin therapy in diabetic angiopathy in ischemic hindlimbs. As a result, STZ-DM mice frequently lost their hindlimbs after induced ischemia, whereas non-DM mice did not. Supplementation with statins significantly prevented autoamputation. We previously showed that diabetic vascular complications are caused by impaired expression of PDGF-BB, but statin therapy did not enhance PDGF-BB expression. Statins helped enhance endogenous endothelial nitric oxide (NO) synthase (eNOS) expression. Furthermore, the inhibition of NO synthesis by the administration of Nω-nitro-l-arginine methyl ester impaired the ability of statins to prevent STZ-DM mouse limb autoamputation, indicating that the therapeutic effect of statins in hindlimb ischemia in STZ-DM mice occurs via the eNOS/NO pathway. A combination therapy of statins and PDGF-BB gene supplementation was more effective for diabetic angiopathy than either therapy alone. In conclusion, these findings indicate that statin therapy might be useful for preventing intractable diabetic foot disease in patients with diabetic angiopathy.

[Diabetes mellitus and coronary artery disease--a high risk combination]

Patients with diabetes mellitus are often not recognized in clinical routine, but also not well characterized in clinical trials. As a diagnostic approach it is recommended to test fasting glucose and glycosylated hemoglobin (HbA1c) in every patient with coronary artery disease (CAD). HbA1c, in addition, provides important prognostic information. Patients with diabetes mellitus do have an enhanced cardiovascular risk in all stages and during all kind of interventions of CAD. However, diabetes is not equal to diabetes; risk modifying factors such as HbA1c, concomitant diseases and medication have to be considered. Absolute benefit of pharmacological therapies is also enhanced in patients with diabetes compared to non-diabetics. However, statins or anti-hypertensive treatment seem to be even more effective in reducing cardiovascular events than pure control of glucose levels alone. During percutaneous interventions (PCI) glycoprotein IIb/IIIa-inhibitors reduce mortality in diabetics, an effect which may be partially also achieved by Clopidogrel. Glitazones reduce restenosis rates; however, clinical end point studies are still ongoing. After PCI, restenosis may be a predictor of mortality in patients with diabetes. Whether drug eluting stents, besides effectively reducing restenosis, may also reduce hard clinical events in patients with diabetes remains to be demonstrated. Current available studies comparing PCI with bypass are limited due to not considered factors (stenosis morphology), randomization bias, and faster progress of technology compared to study termination. During an acute coronary syndrome/myocardial infarction, hyperglycemia is an adverse prognostic marker. However, so far studies using glucose-insulin-potassium (GIK) infusion have not been convincingly demonstrate to be beneficial.

Simvastatin with or without ezetimibe in familial hypercholesterolemia

BACKGROUND

Ezetimibe, a cholesterol-absorption inhibitor, reduces levels of low-density lipoprotein (LDL) cholesterol when added to statin treatment. However, the effect of ezetimibe on the progression of atherosclerosis remains unknown.

METHODS

We conducted a double-blind, randomized, 24-month trial comparing the effects of daily therapy with 80 mg of simvastatin either with placebo or with 10 mg of ezetimibe in 720 patients with familial hypercholesterolemia. Patients underwent B-mode ultrasonography to assess the intima-media thickness of the walls of the carotid and femoral arteries. The primary outcome measure was the change in the mean carotid-artery intima-media thickness, which was defined as the average of the means of the far-wall intima-media thickness of the right and left common carotid arteries, carotid bulbs, and internal carotid arteries.

RESULTS

The primary outcome, the mean (+/-SE) change in the carotid-artery intima-media thickness, was 0.0058+/-0.0037 mm in the simvastatin-only group and 0.0111+/-0.0038 mm in the simvastatin-plus-ezetimibe (combined-therapy) group (P=0.29). Secondary outcomes (consisting of other variables regarding the intima-media thickness of the carotid and femoral arteries) did not differ significantly between the two groups. At the end of the study, the mean (+/-SD) LDL cholesterol level was 192.7+/-60.3 mg per deciliter (4.98+/-1.56 mmol per liter) in the simvastatin group and 141.3+/-52.6 mg per deciliter (3.65+/-1.36 mmol per liter) in the combined-therapy group (a between-group difference of 16.5%, P<0.01). The differences between the two groups in reductions in levels of triglycerides and C-reactive protein were 6.6% and 25.7%, respectively, with greater reductions in the combined-therapy group (P<0.01 for both comparisons). Side-effect and safety profiles were similar in the two groups.

CONCLUSIONS

In patients with familial hypercholesterolemia, combined therapy with ezetimibe and simvastatin did not result in a significant difference in changes in intima-media thickness, as compared with simvastatin alone, despite decreases in levels of LDL cholesterol and C-reactive protein. (ClinicalTrials.gov number, NCT00552097 [ClinicalTrials.gov].).

The role of statins in heart failure

HMG CoA reductase inhibitors (statins) have an established place in the treatment of coronary artery disease. However, their role in the treatment of heart failure (HF), including HF due to coronary artery disease, has been controversial since beneficial as well as possible harmful effects may occur. Several recent studies lend support for a beneficial effect of the statins in HF. These include: (i) post hoc subgroup analyses of prospective randomized clinical trials of statin therapy among patients with stable coronary artery disease where statins reduce the incidence of new HF; (ii) subgroup analysis of the evidence of statin use in large HF trails with different medication and medical devices; (iii) retrospective observational studies of statin use in HF; and (iv) prospective randomized clinical trials of statins in non-ischemic. Beneficial effects include attenuation of cardiac hypertrophy, improvement in endothelial function, anti-inflammatory effects, reduction in the activity of matrix metalloproteinases, reduction in apoptosis, interference with neurohormones, and improved homeostasis. However, there are also theoretical concerns about statins in HF, and existing literature for their safety and efficacy in HF patients has been limited by the retrospective or observational nature of these analyses, examination of incompletely validated surrogate endpoints and small prospective studies in subgroups of HF subjects. In contrast with the normal population, low concentrations of LDL and total cholesterol are associated with a worse prognosis in HF patients and a possible mechanism is reduction in ubiquinone (coenzyme Q10) levels, which is required for oxidative phosphorylation in cells. The safety aspect of these drugs in HF patients needs to be answered before statins can be recommended as a routine drug. For the moment there are several large-scale prospective outcome studies in HF which probably will give us more definitive answers.

A potential role of the CXC chemokine GROalpha in atherosclerosis and plaque destabilization: downregulatory effects of statins

OBJECTIVE

We examined the role of the CXCR2 ligand growth-related oncogene (GRO) alpha in human atherosclerosis.

METHODS AND RESULTS

GROalpha levels were examined by enzyme immunoassay, real-time quantitative RT-PCR, and cDNA microarrays. The in vitro effect of statins on GROalpha was examined in endothelial cells and THP-1 macrophages. Our main findings were: (1) GROalpha was among the 10 most differentially expressed transcripts comparing peripheral blood mononuclear cells (PBMCs) from patients with coronary artery disease (CAD) and healthy controls. (2) Both patients with stable (n=41) and particularly those with unstable (n=47) angina had increased plasma levels of GROalpha comparing controls (n=20). (3) We found increased expression of GROalpha within symptomatic carotid plaques, located to macrophages and endothelial cells. (4) GROalpha enhanced the release of matrix metalloproteinases in vascular smooth muscle cells, and increased the binding of acetylated LDL in macrophages. (5) Atorvastatin downregulated GROalpha levels as shown both in vitro in endothelial cells and macrophages and in vivo in PBMCs from CAD patients. (6) The effect on GROalpha in endothelial cells involved increased storage and reduced secretion of GROalpha.

CONCLUSIONS

GROalpha could be involved in atherogenesis and plaque destabilization, potentially contributing to inflammation, matrix degradation, and lipid accumulation within the atherosclerotic lesion.

Activatable magnetic resonance imaging agent reports myeloperoxidase activity in healing infarcts and noninvasively detects the antiinflammatory effects of atorvastatin on ischemia-reperfusion injury

BACKGROUND

Ischemic injury of the myocardium causes timed recruitment of neutrophils and monocytes/macrophages, which produce substantial amounts of local myeloperoxidase (MPO). MPO forms reactive chlorinating species capable of inflicting oxidative stress and altering protein function by covalent modification. We have used a small-molecule, gadolinium-based activatable sensor for magnetic resonance imaging of MPO activity (MPO-Gd). MPO-Gd is first radicalized by MPO and then either spontaneously oligomerizes or binds to matrix proteins, all leading to enhanced spin-lattice relaxivity and delayed washout kinetics. We hypothesized that MPO imaging could be used to measure inflammatory responses after myocardial ischemia locally and noninvasively in a murine model.

METHODS AND RESULTS

We injected 0.3 mmol/kg MPO-Gd (or Gd-DTPA as control) and performed magnetic resonance imaging up to 120 minutes later in mice 2 days after myocardial infarction. The contrast-to-noise ratio (infarct versus septum) after Gd-DTPA injection peaked at 10 minutes and returned to preinjection values at 60 minutes. After injection of MPO-Gd, the contrast-to-noise ratio peaked later and was higher than Gd-DTPA (40.8+/-10.4 versus 10.5+/-0.2; P<0.05). MPO imaging was validated by magnetic resonance imaging of MPO-/- mice and correlated well with immunoreactive staining (r2=0.92, P<0.05), tissue activity by guaiacol assay (r2=0.65, P<0.001), and immunoblotting. In time course imaging, activity peaked 2 days after coronary ligation. Flow cytometry of digested infarcts detected MPO in neutrophils and monocytes/macrophages. Furthermore, serial MPO imaging accurately tracked the antiinflammatory effects of atorvastatin therapy after ischemia-reperfusion injury.

CONCLUSIONS

MPO-Gd enables in vivo assessment of MPO activity in injured myocardium. This approach allows noninvasive evaluation of the inflammatory response to ischemia and has the potential to guide the development of novel cardioprotective therapies.

Inflammation and atherosclerosis

Atherosclerosis, the cause of myocardial infarction, stroke, and ischemic gangrene, is an inflammatory disease. The atherosclerotic process is initiated when cholesterol-containing low-density lipoproteins accumulate in the intima and activate the endothelium. Leukocyte adhesion molecules and chemokines promote recruitment of monocytes and T cells. Monocytes differentiate into macrophages and upregulate pattern recognition receptors, including scavenger receptors and toll-like receptors. Scavenger receptors mediate lipoprotein internalization, which leads to foam-cell formation. Toll-like receptors transmit activating signals that lead to the release of cytokines, proteases, and vasoactive molecules. T cells in lesions recognize local antigens and mount T helper-1 responses with secretion of pro-inflammatory cytokines that contribute to local inflammation and growth of the plaque. Intensified inflammatory activation may lead to local proteolysis, plaque rupture, and thrombus formation, which causes ischemia and infarction. Inflammatory markers are already used to monitor the disease process and anti-inflammatory therapy may be useful to control disease activity.

Subendothelial lipoprotein retention as the initiating process in atherosclerosis: update and therapeutic implications

The key initiating process in atherogenesis is the subendothelial retention of apolipoprotein B-containing lipoproteins. Local biological responses to these retained lipoproteins, including a chronic and maladaptive macrophage- and T-cell-dominated inflammatory response, promote subsequent lesion development. The most effective therapy against atherothrombotic cardiovascular disease to date--low density lipoprotein-lowering drugs--is based on the principle that decreasing circulating apolipoprotein B lipoproteins decreases the probability that they will enter and be retained in the subendothelium. Ongoing improvements in this area include more aggressive lowering of low-density lipoprotein and other atherogenic lipoproteins in the plasma and initiation of low-density lipoprotein-lowering therapy at an earlier age in at-risk individuals. Potential future therapeutic approaches include attempts to block the interaction of apolipoprotein B lipoproteins with the specific subendothelial matrix molecules that mediate retention and to interfere with accessory molecules within the arterial wall that promote retention such as lipoprotein lipase, secretory sphingomyelinase, and secretory phospholipase A2. Although not the primary focus of this review, therapeutic strategies that target the proatherogenic responses to retained lipoproteins and that promote the removal of atherogenic components of retained lipoproteins also hold promise. The finding that certain human populations of individuals who maintain lifelong low plasma levels of apolipoprotein B lipoproteins have an approximately 90% decreased risk of coronary artery disease gives hope that our further understanding of the pathogenesis of this leading killer could lead to its eradication.

The mechanism underlying vascular smooth muscle cell apoptosis induced by atorvastatin may be mainly associated with down-regulation of survivin expression

PURPOSE

Studies have shown that statins may induce vascular smooth muscle cells (VSMCs) apoptosis. But its mechanisms are incompletely understood. In this study, we investigate the effects of atorvastatin and survivin antisense oligonucleotides (ASODN) on VSMCs apoptosis and the relation between survivin and VSMCs apoptosis.

MATERIALS AND METHODS

Cultured VSMCs were treated with atorvastatin and vascular endothelial grow factor (VEGF). Apoptosis of VSMCs at 6-72 h after treatment with atorvastatin was detected by means of Hoechst33258 staining. Survivin and Fas factors expression were detected by means of immunohistochemistry. Survivin and Fas mRNA expression were detected by means of RT-PCR. In order to determine the relations between survivin and VSMCs apoptosis, we also performed transfection of VSMCs with survivin ASODN using GenePORTER Transfection Reagent and studied the survivin protein expression by means of western blotting.

RESULTS

VSMCs apoptosis after treatment with atorvastatin was increased in a dose- and time-dependent manner. The expression of survivin and survivin mRNA in VSMCs was significantly down-regulated at 24 h and disappeared at 48-72 h after treatment with atorvastatin. Fas and Fas mRNA in VSMCs could only be detected at 72 h and not at 6-48 h after treatment with atorvastatin. We did not observe any effects of VEGF on VSMCs apoptosis, on survivin and survivin mRNA expression, and on Fas and Fas mRNA expression in VSMCs after treatment with atorvastatin. At 48 hours after the start of transfection, survivin protein expression was significantly reduced after transfection with 0.5, 1.0 and 2.0 microg/ml of survivin ASODN and there was no survivin protein expression after transfection with 3.0 and 4.0 microg/ml of survivin ASODN. In contrast, in the GenePORTER only and SODN studies, survivin protein expression was observed with western blotting. Hoechst33258 staining showed that treatment of VSMCs with survivin ASODN resulted in VSMCs apoptosis.

CONCLUSIONS

Atorvastatin induces VSMCs apoptosis in a dose- and time-dependent manner. Transfection of survivin ASODN can directly induce VSMCs apoptosis. The mechanisms of VSMCs apoptosis induced by atorvastatin may be mainly associated with down-regulation of survivin expression in VSMCs. Up-regulation of Fas in VSMCs may play a role in later stages following atorvastatin treatment.

Influenza viruses in animal wildlife populations

Influenza viruses belong to the family Orthomyxoviridae. Genus Influenza A viruses are true zoonotic agents with many animal reservoirs, whereas genus Influenza B viruses are generally considered to be a virus of humans. The genome of influenza A viruses consists of eight unique segments of single-stranded RNA of negative polarity; they are typed according to their surface proteins, hemagglutinin (HA) and neuraminidase (NA). HA and NA, the major antigenic determinants of influenza A viruses, are present in 16 and nine serologic subtypes, respectively. Annual epidemics and occasional pandemics of influenza in humans depend on the continued evolution of influenza viruses. Although they have numerous potential host populations, most of our genetic and biologic data are obtained from studies of domestic populations of species such as chickens, turkeys, swine, and horses. Concerning wildlife populations, including wild populations of these domesticated species, much less is known. The purpose of this review is to establish what role wildlife populations play in the continued evolution of influenza viruses. Future work needs to determine what chain of events makes it possible for an influenza virus to be successfully transmitted to, and more importantly within, an alternative host population. Even questions as fundamental as which hosts can transmit viruses to humans remain unanswered so far.

The Impact of Statin Treatment on Presentation Mode and Early Outcomes in Acute Coronary Syndromes

OBJECTIVES

The role of statin use in the treatment of acute coronary syndromes (ACS) is not clear. The aim of our study was to evaluate the role of statins in ACS.

METHODS

Using data from the Acute Myocardial Infarction in Switzerland (AMIS Plus) Project, we compared the effects of chronic statin use, statin therapy after admission and no statin therapy on presentation mode and outcomes in ACS.

RESULTS

Available data from the period 2001-2006 including 11,603 patients were analyzed. Major cardiac event rates and in-hospital mortality were more common in statin-naive patients compared to patients who received statins.

CONCLUSIONS

Our results support the importance of statin treatment in ACS. Chronic statin therapy seems to alter the initial presentation of ACS but it is questionable whether it provides an additional effect on early outcomes compared to the establishment of statin therapy after admission in statin-naive patients.

Endotoxin-induced effects on platelets and monocytes in an in vivo model of inflammation

AIMS

Chronic inflammation is a major contributing factor to atherosclerosis and various markers of inflammation, fibrinolysis and coagulation are upregulated in patients with established atherosclerotic disease. The aim of this study was to investigate the direct and short-term effects of inflammation on platelet and monocyte activation with an in vivo model of endotoxemia in healthy volunteers.

METHODS AND RESULTS

In this study, 13 healthy male subjects with a mean age of 29.5+/-5.4 years received intravenous administration of lipopolysaccharide (LPS; 20 IU/kg IV). The kinetics of CD40-ligand and CD62P expression on platelets, tissue-factor binding on monocytes and platelet-monocyte aggregates were measured by whole blood flow cytometry at baseline and at 1, 2, 4, 6 and 24 hours after LPS administration. Plasma levels of soluble CD40-ligand were measured with an ELISA over the same time course. Platelet-monocyte aggregates, tissue-factor binding on monocytes and surface expression of platelet CD40L significantly increased in experimental endotoxemia in vivo, reaching peak values 1 hour after LPS administration. All values returned to baseline after 24 hours. Surface expression of CD62P on platelets and plasma levels of sCD40L did not change significantly in response to LPS.

CONCLUSIONS

In vivo administration of endotoxin leads to an activation of platelets and monocytes with an upregulation of proatherogenic CD40L on platelets. These findings underpin the role of inflammation in early atherogenesis through platelet and monocyte activation in an in vivo model.

Role of Krüppel-Like Transcription Factors in Endothelial Biology

Krüppel-like factors are members of the zinc finger family of transcription factors that have been implicated as playing key roles in regulating cellular differentiation and tissue development. Studies over the past several years support an important role for this family of factors in vascular biology. This review summarizes the role of Krüppel-like factors in endothelial cell biology.

Co-administration of ezetimibe and simvastatin in acute myocardial infarction

BACKGROUND

Recent trials in acute myocardial infarction indicate that intensive and early statin therapy that lowers low-density lipoprotein cholesterol (LDL-C) to < or = 70 mg dL(-1) is beneficial. The combination of statins with ezetimibe, a newly developed cholesterol-absorption inhibitor, can lead to a further reduction in LDL-C of up to 26%. In this study, we examined the rapidity and intensity of the lipid-lowering effect of ezetimibe co-administered with simvastatin immediately after myocardial infarction.

MATERIALS AND METHODS

Sixty patients admitted for acute myocardial infarction were randomized to receive either simvastatin 40 mg (SIMVA), a combination of simvastatin 40 mg and ezetimibe 10 mg (EZE/SIMVA), or no lipid-lowering drugs (NLLD) and had their lipid levels assessed 2, 4 and 7 days later.

RESULTS

At baseline, cardiovascular risk factors were similar in all three groups [mean (SD) LDL-C of 141 (36) mg dL(-1)]. At days 2 , 4 and 7 there was no significant change in mean LDL-C levels in the NLLD group (-10%, -6%, and -9%, all P > 0.09), while there were significant reductions with SIMVA (-15%, -27%, and -25%, respectively, all P < 0.001 vs. day 0) and even greater reductions with co-administration of EZE/SIMVA (-27%, -41%, and -51%, respectively, all P < 0.001 vs. day 0). The percentages of patients achieving LDL-C below 70 mg dL(-1) at days 4 and 7 were substantially greater with EZE/SIMVA (45% and 55%, respectively) than with SIMVA (5% and 10%, respectively), while no NLLD patient reached this goal. Triglyceride levels showed a progressive increase in the NLLD group (+45% at day 7, P < 0.05 vs. day 0), no change in the SIMVA group, but a decrease in the EZE/SIMVA group (-17% at day 7, P < 0.05 vs. day 0). No significant difference in HDL-C levels, tolerability, or clinical events was observed between the three groups.

CONCLUSIONS

The co-administration of ezetimibe 10 mg with simvastatin 40 mg, by inhibiting cholesterol absorption and production, allowed more patients with acute myocardial infarction to reach LDL-C < or = 70 mg dL(-1) as early as the fourth day of treatment. The effects of such rapid and intense reduction in LDL-C on cardiovascular morbidity and mortality need to be evaluated in future clinical endpoint studies.

C-reactive protein and the prediction of cardiovascular events among those at intermediate risk: moving an inflammatory hypothesis toward consensus

Over 20 large-scale prospective studies show that the inflammatory biomarker high-sensitivity C-reactive protein (hsCRP) is an independent predictor of future cardiovascular events that additionally predicts risk of incident hypertension and diabetes. In many studies, the relative impact of hsCRP is at least as large as that individually of low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, blood pressure, or smoking, and knowledge of hsCRP correctly reclassifies a substantial proportion of "intermediate-risk" individuals into clinically relevant higher- or lower-risk categories. Other studies show the relative benefit of statins to be greater among those with increased hsCRP and that achieved hsCRP levels after statin therapy predict recurrent event rates as much as achieved levels of low-density lipoprotein cholesterol. Nonetheless, it remains controversial whether the time has come to modify traditional algorithms used for global risk detection. As described here, 6 areas of controversy regarding hsCRP are resolvable with a consensus position that focuses in primary prevention on selective use among individuals with 5% to 20% 10-year risk as estimated by Adult Treatment Panel III, and focuses in secondary prevention on high-risk patients being treated with statin therapy. Forthcoming trial data could expand or contract this "screen selectively" policy, and investigators should be open to the possibility that second-generation inflammatory biomarkers may be developed that supplant hsCRP altogether. In the meantime, however, this consensus position on hsCRP should be one to which both advocates and critics of the inflammatory hypothesis of atherosclerosis can adhere because it is one that can immediately improve patient care.

Rosuvastatin restores superoxide dismutase expression and inhibits accumulation of oxidized LDL in the aortic arch of obese dyslipidemic mice

BACKGROUND AND PURPOSE

Our goal was to elucidate mechanisms of the inhibitory effect of rosuvastatin on the accumulation of plaque oxidized low density lipoproteins (oxLDL) and on plaque volume, without lowering cholesterol, in mice with combined leptin and LDL-receptor deficiency (DKO).

EXPERIMENTAL APPROACH

Twelve-week old DKO mice were treated with rosuvastatin (10 mg kg(-1) day(-1), s.c.) or placebo or no treatment for 12 weeks. The effect on blood variables, aortic plaque volume and composition and gene expression in the aorta and in THP-1 cells was assessed.

KEY RESULTS

Rosuvastatin lowered free fatty acids (FFA), triglycerides, and increased insulin sensitivity, without affecting cholesterol. Rosuvastatin lowered the plaque volume, inhibited macrophage, lipid and oxLDL accumulation, and decreased the oxLDL-to-LDL ratio of plaques in the aortic arch. It increased superoxide dismutase 1 (SOD1), CD36, LXR-alpha, ABCA-1 and PPAR-gamma RNA expression in aortic extracts. SOD1 was the strongest inverse correlate of oxLDL. In THP-1 macrophages and foam cells, expression of SOD1 was lower than in THP-1 monocytes. Rosuvastatin restored expression of SOD1 in THP-1 macrophages and foam cells.

CONCLUSIONS AND IMPLICATIONS

Rosuvastatin restored SOD1 expression in THP-1 macrophages and foam cells in vitro and in the aorta of DKO mice. The latter was associated with less oxLDL accumulation within atherosclerotic plaques and inhibition of plaque progression. This effect was obtained at a dose not affecting cholesterol levels but improving insulin sensitivity. SOD1 is a potentially important mediator of the prevention of oxLDL accumulation within atherosclerotic plaques.

Anthocyanin Prevents CD40-Activated Proinflammatory Signaling in Endothelial Cells by Regulating Cholesterol Distribution

Objective— Intracellular tumor necrosis factor receptor-associated factors (TRAFs) translocation to lipid rafts is a key element in CD40-induced signaling. The purpose of this study was to investigate the influence of anthocyanin on CD40-mediated proinflammatory events in human endothelial cells and the underlying possible molecular mechanism.

Methods and Results— Treatment of endothelial cells with anthocyanin prevented from CD40-induced proinflammatory status, measured by production of IL-6, IL-8, and monocyte chemoattractant protein-1 through inhibiting CD40-induced nuclear factor-κB (NF-κB) activation. TRAF-2 played pivotal role in CD40–NF-κB pathway as TRAF-2 small interference RNA (siRNA) diminished CD40-induced NF-κB activation and inflammation. TRAF-2 overexpression increased CD40-mediated NF-κB activation. Moreover, TRAF-2 almost totally recruited to lipid rafts after stimulation by CD40 ligand and depletion of cholesterol diminished CD40-mediated NF-κB activation. Exposure to anthocyanin not only interrupted TRAF-2 recruitment to lipid rafts but also decreased cholesterol content in Triton X-100 insoluble lipid rafts. However, anthocyanin did not influence the interaction between CD40 ligand and CD40 receptor.

Conclusions— Our findings suggest that anthocyanin protects from CD40-induced proinflammatory signaling by preventing TRAF-2 translocation to lipid rafts through regulation of cholesterol distribution, which thereby may represent a mechanism that would explain the anti-inflammatory response of anthocyanin.

Enhanced Expression of the Homeostatic Chemokines CCL19 and CCL21 in Clinical and Experimental Atherosclerosis

Objective— Based on their role in T-cell homing into nonlymphoid tissue, we examined the role of the homeostatic chemokines CCL19 and CCL21 and their common receptor CCR7 in coronary artery disease (CAD).

Methods and Results— We performed studies in patients with stable (n=40) and unstable (n=40) angina and healthy controls (n=20), in vitro studies in T-cells and macrophages, and studies in apolipoprotein-E–deficient (ApoE −/− ) mice and human atherosclerotic carotid plaques. We found increased levels of CCL19 and CCL21 within the atherosclerotic lesions of the ApoE −/− mice, in human atherosclerotic carotid plaques, and in plasma of CAD patients. Whereas strong CCR7 expression was seen in T-cells from murine and human atherosclerotic plaques, circulating T-cells from angina patients showed decreased CCR7 expression. CCL19 and CCL21 promoted an inflammatory phenotype in T-cells and macrophages and increased matrix metalloproteinase (MMP) and tissue factor levels in the latter cell type. Although aggressive statin therapy increased CCR7 and decreased CCL19/CCL21 levels in peripheral blood from CAD patients, conventional therapy did not.

Conclusions— The abnormal regulation of CCL19 and CCL21 and their common receptor in atherosclerosis could contribute to disease progression by recruiting T-cells and macrophages to the atherosclerotic lesions and by promoting inflammatory responses in these cells.

Statins (HMG-CoA reductase inhibitors) decrease postoperative adhesions by increasing peritoneal fibrinolytic activity

OBJECTIVES

The aims of this study were to determine if statins reduce adhesion formation in vivo and to identify the mechanism of action in vitro.

BACKGROUND

: Intraperitoneal adhesions develop in up to 95% of patients following laparotomy. Adhesions are reduced by mechanisms that up-regulate fibrinolysis within the peritoneum. Statins promote fibrinolysis in the cardiovascular system and may play a role in the prevention of adhesions.

METHODS

Adhesions were induced in rats (n = 102) using our previously described ischemic button model. Rats received vehicle (controls), lovastatin (30 mg/kg), or atorvastatin (30 mg/kg) as a single intraperitoneal dose at the time of laparotomy. Animals were killed and adhesions were quantified at day 7. Peritoneal fluid and tissue were collected at day 1 to measure tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) by real-time PCR and ELISA. To assess the effects of statins on wound healing, burst pressures were measured in anastomoses of the colon. The effects of lovastatin on tPA and PAI-1 production were measured in vitro in human mesothelial cells (HMC) in the presence or absence of mevalonate (MVA), geranylgeranyl-pyrophosphate (GGPP) and farnesyl-pyrophosphate (FPP), all intermediates in the cholesterol pathway downstream of HMG-CoA. The effect of a Rho protein inhibitor, exoenzyme C3 transferase, on tPA production was also determined.

RESULTS

Lovastatin and atorvastatin reduced adhesion formation by 26% and 58%, respectively (P < 0.05), without affecting anastomotic burst pressure. At 24 hours, tPA mRNA levels in peritoneal tissue and tPA activity in peritoneal fluid from lovastatin-treated animals were increased by 57% and 379%, respectively (P < 0.05), while PAI-1 levels were unchanged. HMC incubated with either lovastatin or atorvastatin showed concentration-dependent increases in tPA production and decreases in PAI-1 production (P < 0.05). These lovastatin-induced changes in tPA and PAI-1 production were significantly reversed by the addition of MVA, GGPP, and FPP. The Rho protein inhibitor increased tPA production and rescued tPA production from the inhibitory effect of GGPP.

CONCLUSION

These data suggest that statins administered within the peritoneum can up-regulate local fibrinolysis, while the in vitro studies show that this effect may be mediated, in part, by intermediates of the cholesterol biosynthetic pathway that regulate Rho protein signaling.

Overviews of pathogen emergence: which pathogens emerge, when and why?

An emerging pathogen has been defined as the causative agent of an infectious disease whose incidence is increasing following its appearance in a new host population or whose incidence is increasing in an existing population as a result of long-term changes in its underlying epidemiology (Woolhouse and Dye 2001). Although we appear to be in a period where novel diseases are appearing and old diseases are spreading at an unprecedented rate, disease emergence per se is not a new phenomenon. It is almost certain that disease emergence is a routine event in the evolutionary ecology of pathogens, and part of a ubiquitous response of pathogen populations to shifting arrays of host species. While our knowledge of emerging diseases is, for the most part, limited to the time span of the human lineage, this history provides us with a modern reflection of these deeper evolutionary processes, and it is clear from this record that at many times throughout human history, demographic and behavioural changes in society have provided opportunities for pathogens to emerge.