Effects of HMG-CoA reductase inhibitors on endothelial function: role of microdomains and oxidative stress

Statin Overuse in Cerebral Ischemia Without Indications: Systematic Review and Annual US Burden of Adverse Events

BACKGROUND

Statin agents play a major role in secondary prevention after acute cerebral ischemia (ACI) events but are not indicated in all patients with ischemic stroke and transient ischemic attack. National guidelines recommend statins for patients with ACI of large or small vessel atherosclerotic origin and without these stroke mechanisms but coexisting coronary artery disease or primary prevention indications. The potential adverse effect burden of statin overuse in the remaining ACI patients have not been well delineated.

METHODS

Per Preferred Reporting Items of Systematic Reviews and Meta-Analyses guidelines, we performed systematic meta-analyses of: (1) statin randomized clinical trials to determine absolute risk increases for 6 major adverse events; (2) large clinical series to determine the proportion of ACI events due to large or small vessel atherosclerotic disease; and (3) the proportion of remaining patients with coronary artery disease/primary prevention statin indications.

RESULTS

For adverse effects, data were available from 63 randomized clinical trials enrolling 155 107 patients. Statin therapy was associated with an increased risk of the occurrence of 6 conditions: diabetes, myalgia or muscle weakness, myopathy, liver disease, renal insufficiency, and eye disease. Across 55 large series enrolling 53 501 patients, the rate of ACI due to large and small artery atherosclerosis was 45.0% (large artery atherosclerosis 21.6%, small vessel disease 23.4%), the rate of remaining patients with coronary artery disease/primary prevention statin indications was 31.8%, and the rate of patients without statin indications was 23.2%. Data synthesis indicated that, in the United States, were all patients with ACI without statin indications treated with statins, a total of 5601 patients would develop needless adverse events each year, most commonly diabetes, myopathy, and eye disease.

CONCLUSIONS

More than one-fifth of patients with ACI do not have an indication for statins, and statin overuse in these patients could annually lead to over 5600 adverse events each year in the United States, including diabetes, myopathy, and eye disease. These findings emphasize the importance of adhering to guideline indications for the start of statin therapy in ACI.

Potential Benefits and Risks Associated with the Use of Statins

HMG-CoA reductase inhibitors, commonly known as statins, are the primary treatment choice for cardiovascular diseases, which stand as the leading global cause of mortality. Statins also offer various pleiotropic effects, including improved endothelial function, anti-inflammatory properties, reduced oxidative stress, anti-thrombotic effects, and the stabilization of atherosclerotic plaques. However, the usage of statins can be accompanied by a range of adverse effects, such as the development of type 2 diabetes mellitus, muscular symptoms, liver toxicity, kidney diseases, cataracts, hemorrhagic strokes, and psychiatric complications. These issues are referred to as statin-associated symptoms (SAS) and are relatively infrequent in clinical trials, making it challenging to attribute them to statin use definitively. Therefore, these symptoms can lead to significant problems, necessitating dose adjustments or discontinuation of statin therapy. This review aims to provide a comprehensive overview of the mechanism of action, potential advantages, and associated risks of statin utilization in clinical settings.

Cholesterol in Brain Development and Perinatal Brain Injury: More than a Building Block

The central nervous system (CNS) is enriched with important classes of lipids, in which cholesterol is known to make up a major portion of myelin sheaths, besides being a structural and functional unit of CNS cell membranes. Unlike in the adult brain, where the cholesterol pool is relatively stable, cholesterol is synthesized and accumulated at the highest rate in the developing brain to meet the needs of rapid brain growth at this stage, which is also a critical period for neuroplasticity. In addition to its biophysical role in membrane organization, cholesterol is crucial for brain development due to its involvement in brain patterning, myelination, neuronal differentiation, and synaptogenesis. Thus any injuries to the immature brain that affect cholesterol homeostasis may have long-term adverse neurological consequences. In this review, we describe the unique features of brain cholesterol biosynthesis and metabolism, cholesterol trafficking between different cell types, and highlight cholesterol-dependent biological processes during brain maturation. We also discuss the association of impaired cholesterol homeostasis with several forms of perinatal brain disorders in term and preterm newborns, including hypoxic-ischemic encephalopathy. Strategies targeting the cholesterol pathways may open new avenues for the diagnosis and treatment of developmental brain injury.

Role of EPA in Inflammation: Mechanisms, Effects, and Clinical Relevance

Many chronic inflammatory processes are linked with the continuous release of inflammatory mediators and the activation of harmful signal-transduction pathways that are able to facilitate disease progression. In this context atherosclerosis represents the most common pathological substrate of coronary heart disease, and the characterization of the disease as a chronic low-grade inflammatory condition is now validated. The biomarkers of inflammation associated with clinical cardiovascular risk support the theory that targeted anti-inflammatory treatment appears to be a promising strategy in reducing residual cardiovascular risk. Several literature data highlight cardioprotective effects of the long-chain omega-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA). This PUFA lowers plasma triglyceride levels and has potential beneficial effects on atherosclerotic plaques. Preclinical studies reported that EPA reduces both pro-inflammatory cytokines and chemokines levels. Clinical studies in patients with coronary artery disease that receive pharmacological statin therapy suggest that EPA may decrease plaque vulnerability preventing plaque progression. This review aims to provide an overview of the links between inflammation and cardiovascular risk factors, importantly focusing on the role of diet, in particular examining the proposed role of EPA as well as the success or failure of standard pharmacological therapy for cardiovascular diseases.

Efficacy of intensive lipid-lowering therapy with statins stratified by blood pressure levels in patients with type 2 diabetes mellitus and retinopathy: Insight from the EMPATHY study

Intensive lipid-lowering therapy is recommended in individuals exhibiting type 2 diabetes mellitus (T2DM) with microvascular complications (as high-risk patients), even without known cardiovascular disease (CVD). However, evidence is insufficient to stratify the patients who would benefit from intensive therapy among them. Hypertension is a major risk factor, and uncontrolled blood pressure (BP) is associated with increased CVD risk. We evaluated the efficacy of intensive vs. standard statin therapy for primary CVD prevention among T2DM patients with retinopathy stratified by BP levels. We used the dataset from the EMPATHY study, which compared intensive statin therapy targeting low-density lipoprotein cholesterol (LDL-C) levels of <70 mg/dL and standard therapy targeting LDL-C levels ranging from ≥100 to <120 mg/dL in T2DM patients with retinopathy without known CVD. A total of 4980 patients were divided into BP ≥ 130/80 mmHg (systolic BP ≥ 130 mmHg and/or diastolic BP ≥ 80 mmHg, n = 3335) and BP < 130/80 mmHg (n = 1645) subgroups by baseline BP levels. During the median follow-up of 36.8 months, 281 CVD events were observed. Consistent with previous studies, CVD events occurred more frequently in the BP ≥ 130/80 mmHg subgroup than in the BP < 130/80 mmHg subgroup (P < 0.001). In the BP ≥ 130/80 mmHg subgroup, intensive statin therapy was associated with lower CVD risk (HR 0.70, P = 0.015) than standard therapy after adjustment. No such association was observed in the BP < 130/80 mmHg subgroup. The interaction between BP subgroup and statin therapy was significant. In conclusion, intensive statin therapy targeting LDL-C < 70 mg/dL provided benefits in primary CVD prevention when compared with standard therapy among T2DM patients with retinopathy and BP ≥ 130/80 mmHg.

Zebrafish as a Model for the Study of Lipid-Lowering Drug-Induced Myopathies

Drug-induced myopathies are classified as acquired myopathies caused by exogenous factors. These pathological conditions develop in patients without muscle disease and are triggered by a variety of medicaments, including lipid-lowering drugs (LLDs) such as statins, fibrates, and ezetimibe. Here we summarise the current knowledge gained via studies conducted using various models, such as cell lines and mammalian models, and compare them with the results obtained in zebrafish (Danio rerio) studies. Zebrafish have proven to be an excellent research tool for studying dyslipidaemias as a model of these pathological conditions. This system enables in-vivo characterization of drug and gene candidates to further the understanding of disease aetiology and develop new therapeutic strategies. Our review also considers important environmental issues arising from the indiscriminate use of LLDs worldwide. The widespread use and importance of drugs such as statins and fibrates justify the need for the meticulous study of their mechanism of action and the side effects they cause.

Effectiveness of statin intensive therapy in type 2 diabetes mellitus with high visit-to-visit blood pressure variability

BACKGROUND

Intensive lipid-lowering therapy is recommended in type 2 diabetes mellitus (T2DM) patients with target organ damage. However, the evidence is insufficient to stratify the patients who will benefit from the intensive therapy among them. High visit-to-visit variability in systolic blood pressure (SBP) is associated with increased risk of cardiovascular events. We investigated the effectiveness of intensive versus standard statin therapy in the primary prevention of cardiovascular events among T2DM patients with retinopathy stratified by visit-to-visit SBP variability.

METHODS

The standard versus intensive statin therapy for hypercholesterolemic patients with diabetic retinopathy study was the first trial comparing statin intensive therapy targeting low-density lipoprotein cholesterol (LDL-C) <70 mg/dl and standard therapy targeting LDL-C ≥100 to <120 mg/dl in T2DM patients with retinopathy without known cardiovascular disease. Using this dataset, we divided the patients into two subpopulations based on standard deviation (SD) and average real variability (ARV) of clinic SBP within the initial 6 months.

RESULTS

In a total of 4899 patients, 240 composite cardiovascular events were observed during a median follow-up of 37.3 months. In multivariable-adjusted model comparing intensive versus standard therapy, the hazard ratios for composite cardiovascular events were 0.64 (95% CI 0.45-0.90) and 1.21 (95% CI 0.82-1.80) in patients with high and low SBP variability as defined by SD, respectively. Interaction between SBP variability and statin therapy was significant (P = 0.018). The analysis using ARV of SBP showed similar results.

CONCLUSION

Statin intensive therapy targeting LDL-C <70 mg/dl had benefits in primary prevention of cardiovascular events compared with standard therapy among T2DM patients with retinopathy having high, but not low, visit-to-visit SBP variability.

Erythrocyte-derived microvesicles induce arterial spasms in JAK2V617F myeloproliferative neoplasm

Arterial cardiovascular events are the leading cause of death in patients with JAK2V617F myeloproliferative neoplasms (MPNs). However, their mechanisms are poorly understood. The high prevalence of myocardial infarction without significant coronary stenosis or atherosclerosis in patients with MPNs suggests that vascular function is altered. The consequences of JAK2V617F mutation on vascular reactivity are unknown. We observe here increased responses to vasoconstrictors in arteries from Jak2V617F mice resulting from a disturbed endothelial NO pathway and increased endothelial oxidative stress. This response was reproduced in WT mice by circulating microvesicles isolated from patients carrying JAK2V617F and by erythrocyte-derived microvesicles from transgenic mice. Microvesicles of other cellular origins had no effect. This effect was observed ex vivo on isolated aortas, but also in vivo on femoral arteries. Proteomic analysis of microvesicles derived from JAK2V617F erythrocytes identified increased expression of myeloperoxidase as the likely mechanism accounting for their effect. Myeloperoxidase inhibition in microvesicles derived from JAK2V617F erythrocytes suppressed their effect on oxidative stress. Antioxidants such as simvastatin and N-acetyl cysteine improved arterial dysfunction in Jak2V617F mice. In conclusion, JAK2V617F MPNs are characterized by exacerbated vasoconstrictor responses resulting from increased endothelial oxidative stress caused by circulating erythrocyte-derived microvesicles. Simvastatin appears to be a promising therapeutic strategy in this setting.

Impact of statin on long-term outcome among patients with end-stage renal disease with acute myocardial infarction (AMI): a nationwide case-control study

BACKGROUND

Use of statin has been associated with reduced risk of cardiovascular diseases events and mortality. However, in patients with end-stage renal disease (ESRD), the protective effects of statin are controversial. To evaluate the impact of chronic statin use on clinical outcomes of patients with acute myocardial infarction (AMI) with ESRD.

METHODS

We enrolled 8056 patients with ESRD who were initially diagnosed and admitted for first AMI from Taiwan's National Health Insurance Research Database. Of which, 2134 patients underwent statin therapy. We randomly selected and use age, sex, hypertension, diabetes mellitus (DM), peripheral vascular diseases (PVD), heart failure (HF), cerebrovascular accidents (CVA), chronic obstructive pulmonary disease, matched with the study group as controls (non-stain user). We compared the effects of statin use in term of all-cause death among patients with AMI with ESRD.

RESULTS

Statin use resulted in a significantly higher survival rate in patients ith AMI with ESRD compared with non-statin users. After adjusted the comorbidities the male patients and patients with DM, PVD, HF and CVA had lower long-term survival rate (all p<0.001). Patients who underwent percutaneous coronary intervention (p<0.001), ACE inhibitors/angiotensin II receptor blockers (p<0.001), β receptor blockers (p<0.001) and statin therapy (p=0.007) had better long-term survival rate. Patients with AMI with ESRD on statin therapy exhibited a significantly lower risk of mortality compared with non-statin users (p<0.0001).

CONCLUSION

Among patients with ESRD with AMI, statin therapy was associated with reduced all-cause mortality.

Atorvastatin attenuates vascular remodelling in spontaneously hypertensive rats via the protein kinase D/extracellular signal-regulated kinase 5 pathway

The present study was conducted to determine whether atorvastatin reduces hypertension-induced vascular remodelling and whether its effects involve protein kinase D (PKD) and extracellular signal-regulated kinase 5 (ERK5). We used 16-week-old spontaneously hypertensive rats (SHRs) and age-matched Wistar-Kyoto (WKY) rats. The blood pressure and serum lipid concentration were measured. Changes in the vascular morphology and histology were examined using H&E, Masson' s trichrome, and Sirius Red staining. The media thickness (MT), ratio of MT to lumen diameter (LD) (MT/LD), collagen volume fraction (CVF) and hydroxyproline content were measured to evaluate vascular remodelling. Atorvastatin (50 mg/kg/day) was administered for 8 weeks. Increased blood pressure and vascular remodelling were more prominent in SHRs than in WKY rats. SHRs also had elevated PKD and ERK5 activation. The systolic blood pressure, MT/LD ratio, and hydroxyproline content were positively correlated with the activation level of PKD and ERK5 in SHRs. Atorvastatin significantly attenuated the activation of PKD and ERK5. Overall, this study demonstrated that atorvastatin could reverse vascular remodelling in SHRs. The PKD/ERK5 signalling pathway might be important for elucidating the beneficial pleiotropic effects of atorvastatin on vascular remodelling.

Statins and autoimmunity: State-of-the-art

HMG-CoA reductase inhibitors, or statins, are potent plasma LDL-cholesterol (LDL-c) lowering agents. Since the introduction of the first statin, lovastatin, in 1987, accumulating evidence showed that non-cholesterol lowering effects play an important role in their efficacy to reduce atherosclerotic cardiovascular disease (ASCVD). Thus, these non-LDL-c lowering properties could benefit patients with immune-mediated diseases. Statins and their associated immune-modulating roles have recently received much attention. Different statins have been administered in various experimental and clinical studies focused on autoimmunity. The results indicate that statins can modulate immune responses through mevalonate pathway-dependent and -independent mechanisms. The anti-inflammatory and immune-modulating effects include cell adhesion, migration of antigen presenting cells, and differentiation, as well as activation, of T-cells. In various autoimmune diseases (e.g. rheumatoid arthritis, lupus, and multiple sclerosis), promising results have been obtained to date.

Simvastatin improves lysosome function via enhancing lysosome biogenesis in endothelial cells

Nlrp3 inflammasomes were shown to play a critical role in triggering obesity-associated early onsets of cardiovascular complications such as endothelial barrier dysfunction with endothelial hyperpermeability. Statins prevent endothelial dysfunction and decrease cardiovascular risk in patients with obesity and diabetes. However, it remains unclear whether statin treatment for obesity-induced endothelial barrier dysfunction is in part due to the blockade of Nlrp3 inflammasome signaling axis. The results showed that simvastatin, a clinically and widely used statin, prevented free fatty acid-induced endothelial hyperpermeability and disruption of ZO-1 and VE-cadherin junctions in mouse microvascular endothelial cells (MVECs). This protective effect of simvastatin was largely due to improved lysosome function that attenuated lysosome injury-mediated Nlrp3 inflammasome activation and subsequent release of high mobility group box protein-1 (HMGB1). Mechanistically, simvastatin induces autophagy that promotes removal of damaged lysosomes and also promotes lysosome regeneration that preserves lysosome function. Collectively, simvastatin treatment improves lysosome function via enhancing lysosome biogenesis and its autophagic turnover, which may be an important mechanism to suppress Nlrp3 inflammasome activation and prevents endothelial hyperpermeability in obesity.

Changes of the coronary arteries and cardiac microvasculature with aging: Implications for translational research and clinical practice

Aging results in functional and structural changes in the cardiovascular system, translating into a progressive increase of mechanical vessel stiffness, due to a combination of changes in micro-RNA expression patterns, autophagy, arterial calcification, smooth muscle cell migration and proliferation. The two pivotal mechanisms of aging-related endothelial dysfunction are oxidative stress and inflammation, even in the absence of clinical disease. A comprehensive understanding of the aging process is emerging as a primary concern in literature, as vascular aging has recently become a target for prevention and treatment of cardiovascular disease. Change of life-style, diet, antioxidant regimens, anti-inflammatory treatments, senolytic drugs counteract the pro-aging pathways or target senescent cells modulating their detrimental effects. Such therapies aim to reduce the ineluctable burden of age and contrast aging-associated cardiovascular dysfunction. This narrative review intends to summarize the macrovascular and microvascular changes related with aging, as a better understanding of the pathways leading to arterial aging may contribute to design new mechanism-based therapeutic approaches to attenuate the features of vascular senescence and its clinical impact on the cardiovascular system.

Biocatalyzed Synthesis of Statins: A Sustainable Strategy for the Preparation of Valuable Drugs

Statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, are the largest selling class of drugs prescribed for the pharmacological treatment of hypercholesterolemia and dyslipidaemia. Statins also possess other therapeutic effects, called pleiotropic, because the blockade of the conversion of HMG-CoA to (R)-mevalonate produces a concomitant inhibition of the biosynthesis of numerous isoprenoid metabolites (e.g., geranylgeranyl pyrophosphate (GGPP) or farnesyl pyrophosphate (FPP)). Thus, the prenylation of several cell signalling proteins (small GTPase family members: Ras, Rac, and Rho) is hampered, so that these molecular switches, controlling multiple pathways and cell functions (maintenance of cell shape, motility, factor secretion, differentiation, and proliferation) are regulated, leading to beneficial effects in cardiovascular health, regulation of the immune system, anti-inflammatory and immunosuppressive properties, prevention and treatment of sepsis, treatment of autoimmune diseases, osteoporosis, kidney and neurological disorders, or even in cancer therapy. Thus, there is a growing interest in developing more sustainable protocols for preparation of statins, and the introduction of biocatalyzed steps into the synthetic pathways is highly advantageous—synthetic routes are conducted under mild reaction conditions, at ambient temperature, and can use water as a reaction medium in many cases. Furthermore, their high selectivity avoids the need for functional group activation and protection/deprotection steps usually required in traditional organic synthesis. Therefore, biocatalysis provides shorter processes, produces less waste, and reduces manufacturing costs and environmental impact. In this review, we will comment on the pleiotropic effects of statins and will illustrate some biotransformations nowadays implemented for statin synthesis.

Statins reduce relapse rate in Takayasu arteritis

BACKGROUND

To investigate the effect of statins on relapse of Takayasu arteritis (TAK), which frequently occurs after achievement of remission.

METHODS

We conducted a retrospective study on TAK patients with active disease, diagnosed between 2012 and 2017. Relapse was defined as recurrence of active disease after achieving remission. Demographic and clinical parameters of patients who experienced relapse were compared to those who did not. To identify factors associated with relapse, significant factors identified in this comparison were included in a multivariate Cox regression analysis. Inverse probability of treatment weighting (IPTW)-adjusted analysis was used to evaluate the influence of statins on relapse.

RESULTS

Of the total 74 TAK patients, 40 (54.1%) patients received statins, whereas 34 (45.9%) patients did not. Relapse was observed in 36 (48.6%) patients of the total 74 TAK patients. Compared with patients who did not experience relapse, patients who experienced relapse were younger (44.5 ± 13.5 years vs 34.1 ± 12.6 years, p = 0.001), had lower prevalence of hypertension (63.2% vs 38.9%, p = 0.037), more commonly had carotidynia (7.9% vs 27.8%, p = 0.025), had higher LDL-cholesterol (84.8 ± 18.8 mg/dl vs 100.5 ± 26.1 mg/dl, p = 0.010), and were less commonly taking statins (71.1% vs 36.1%, p = 0.003). The use of statins was significant in multivariate Cox regression analysis (adjusted hazard ratio 0.260, 95% confidence interval 0.120-0.563, p = 0.001). Furthermore, IPTW-adjusted analysis confirmed that statin use was associated with a lower risk of relapse (IPTW-adjusted hazard ratio 0.153, 95% confidence interval 0.038-0.616, p = 0.008).

CONCLUSION

In TAK, statins can be beneficial in reducing relapse rate after achieving remission.

Reduced membrane cholesterol after chronic hypoxia limits Orai1-mediated pulmonary endothelial Ca2+ entry

Endothelial dysfunction in chronic hypoxia (CH)-induced pulmonary hypertension is characterized by reduced store-operated Ca²⁺ entry (SOCE) and diminished Ca²⁺-dependent production of endothelium-derived vasodilators. We recently reported that SOCE in pulmonary arterial endothelial cells (PAECs) is tightly regulated by membrane cholesterol and that decreased membrane cholesterol is responsible for impaired SOCE after CH. However, the ion channels involved in cholesterol-sensitive SOCE are unknown. We hypothesized that cholesterol facilitates SOCE in PAECs through the interaction of Orai1 and stromal interaction molecule 1 (STIM1). The role of cholesterol in Orai1-mediated SOCE was initially assessed using CH exposure in rats (4 wk, 380 mmHg) as a physiological stimulus to decrease PAEC cholesterol. The effects of Orai1 inhibition with AnCoA4 on SOCE were examined in isolated PAEC sheets from control and CH rats after cholesterol supplementation, substitution of endogenous cholesterol with epicholesterol (Epichol), or vehicle treatment. Whereas cholesterol restored endothelial SOCE in CH rats, both Epichol and AnCoA4 attenuated SOCE only in normoxic controls. The Orai1 inhibitor had no further effect in cells pretreated with Epichol. Using cultured pulmonary endothelial cells to allow better mechanistic analysis of the molecular components of cholesterol-regulated SOCE, we found that Epichol, AnCoA4, and Orai1 siRNA each inhibited SOCE compared with their respective controls. Epichol had no additional effect after knockdown of Orai1. Furthermore, Epichol substitution significantly reduced STIM1-Orai1 interactions as assessed by a proximity ligation assay. We conclude that membrane cholesterol is required for the STIM1-Orai1 interaction necessary to elicit endothelial SOCE. Furthermore, reduced PAEC membrane cholesterol after CH limits Orai1-mediated SOCE. NEW & NOTEWORTHY This research demonstrates a novel contribution of cholesterol to regulate the interaction of Orai1 and stromal interaction molecule 1 required for pulmonary endothelial store-operated Ca²⁺ entry. The results provide a mechanistic basis for impaired pulmonary endothelial Ca²⁺ influx after chronic hypoxia that may contribute to pulmonary hypertension.

Eicosapentaenoic Acid Inhibits Oxidation of ApoB-containing Lipoprotein Particles of Different Size In Vitro When Administered Alone or in Combination With Atorvastatin Active Metabolite Compared With Other Triglyceride-lowering Agents

Eicosapentaenoic acid (EPA) is a triglyceride-lowering agent that reduces circulating levels of the apolipoprotein B (apoB)-containing lipoprotein particles small dense low-density lipoprotein (sdLDL), very–low-density lipoprotein (VLDL), and oxidized low-density lipoprotein (LDL). These benefits may result from the direct antioxidant effects of EPA. To investigate this potential mechanism, these particles were isolated from human plasma, preincubated with EPA in the absence or presence of atorvastatin (active) metabolite, and subjected to copper-initiated oxidation. Lipid oxidation was measured as a function of thiobarbituric acid reactive substances formation. EPA inhibited sdLDL (IC₅₀ ∼2.0 μM) and LDL oxidation (IC₅₀ ∼2.5 μM) in a dose-dependent manner. Greater antioxidant potency was observed for EPA in VLDL. EPA inhibition was enhanced when combined with atorvastatin metabolite at low equimolar concentrations. Other triglyceride-lowering agents (fenofibrate, niacin, and gemfibrozil) and vitamin E did not significantly affect sdLDL, LDL, or VLDL oxidation compared with vehicle-treated controls. Docosahexaenoic acid was also found to inhibit oxidation in these particles but over a shorter time period than EPA. These data support recent clinical findings and suggest that EPA has direct antioxidant benefits in various apoB-containing subfractions that are more pronounced than those of other triglyceride-lowering agents and docosahexaenoic acid.

Oxidative Stress and Acute Kidney Injury in Critical Illness: Pathophysiologic Mechanisms-Biomarkers-Interventions, and Future Perspectives

Acute kidney injury (AKI) is a multifactorial entity that occurs in a variety of clinical settings. Although AKI is not a usual reason for intensive care unit (ICU) admission, it often complicates critically ill patients' clinical course requiring renal replacement therapy progressing sometimes to end-stage renal disease and increasing mortality. The causes of AKI in the group of ICU patients are further complicated from damaged metabolic state, systemic inflammation, sepsis, and hemodynamic dysregulations, leading to an imbalance that generates oxidative stress response. Abundant experimental and to a less extent clinical data support the important role of oxidative stress-related mechanisms in the injury phase of AKI. The purpose of this article is to present the main pathophysiologic mechanisms of AKI in ICU patients focusing on the different aspects of oxidative stress generation, the available evidence of interventional measures for AKI prevention, biomarkers used in a clinical setting, and future perspectives in oxidative stress regulation.

Comparison of Effects of Different Statins on Contrast-Induced Acute Kidney Injury in Rats: Histopathological and Biochemical Findings

Statins are a promising new strategy to prevent contrast-induced acute kidney injury (CI-AKI). In this study we compared the ameliorative effect of different statins in a rat model of CI-AKI. Sprague-Dawley rats were divided into five groups: control group; CI-AKI group; CI-AKI + rosuvastatin group (10 mg/kg/day); CI-AKI + simvastatin group (80 mg/kg/day); and CI-AKI + atorvastatin group (20 mg/kg/day). CI-AKI was induced by dehydration for 72 hours, followed by furosemide intramuscular injection 20 minutes before low-osmolar contrast media (CM) intravenous injection. Statins were administered by oral gavage once daily for 3 consecutive days before CM injection and once 4 hours after CM injection. Rats were sacrificed 24 hours after CM injection, and renal function, kidney histopathology, nitric oxide (NO) metabolites, and markers of oxidative stress, inflammation, and apoptosis were evaluated. The results showed that atorvastatin and rosuvastatin but not simvastatin ameliorated CM-induced serum creatinine elevation and histopathological alterations. Atorvastatin and rosuvastatin showed similar effectiveness against CM-induced oxidative stress, but simvastatin was less effective. Atorvastatin was most effective against NO system dysfunction and cell apoptosis, whereas rosuvastatin was most effective against inflammation. Our findings indicate that statins exhibit differential effects in preventing CI-AKI when given at equivalent lipid-lowering doses.

Novel applications of COX-2 inhibitors, metformin, and statins for the primary chemoprevention of breast cancer

Recent evidence shows that commonly prescribed drugs, such as non-steroidal anti-inflammatory drugs (NSAIDs), metformin, and statins, may have beneficial roles in the primary chemoprevention of breast cancer. Therefore, these drugs could potentially be used in addition to the hormonal drugs currently used for this purpose (namely, selective estrogen receptor modulators and aromatase inhibitors) due to their alternative mechanisms of action.

Relationship between pre-stroke cardiovascular medication use and stroke severity

INTRODUCTION

Stroke is a major health problem with important morbidity and mortality. Various risk factors and cardiovascular medication groups are known to have an influence on stroke incidence, but less is known about the relation between medication use and stroke severity.

AIM

To determine if relationships exist between the pre-stroke cardiovascular medication use and stroke severity.

METHODS

A retrospective study was conducted on a database with anonymized data of 1974 patients with a suspected stroke, admitted to the Universitair Ziekenhuis (UZ) Brussel. Stroke severity was quantified using the National Institute of Health Stroke Scale (NIHSS). Cardiovascular medication groups were first included in a multivariable linear regression model. Second, to obtain clinically interpretable results, all variables that were retained in the final linear regression model were introduced in a cumulative odds ordinal logistic regression model with proportional odds.

RESULTS

Angiotensin II receptor blockers (ARBs), statins, and antiarrhythmics were significantly associated with stroke severity at the 10 % α level in a multivariable linear regression model, suggesting a possible effect of these medication groups on stroke severity. Only pre-stroke statin use showed a significant relationship with the NIHSS score in the ordinal logistic regression model with an adjusted odds ratio of 0.740 (95 % CI 0.580-0.944; p = 0.015).

CONCLUSION

Pre-stroke use of statins is significantly associated with lower stroke severity. No significant relationship was detected between pre-stroke use of other medication groups and stroke severity, defined by the NIHSS score.

Euphol from Euphorbia tirucalli Negatively Modulates TGF-β Responsiveness via TGF-β Receptor Segregation inside Membrane Rafts

Transforming growth factor-β (TGF-β) responsiveness in cultured cells can be modulated by TGF-β partitioning between lipid raft/caveolae- and clathrin-mediated endocytosis pathways. Lipid rafts are plasma membrane microdomains with an important role in cell survival signaling, and cholesterol is necessary for the lipid rafts’ structure and function. Euphol is a euphane-type triterpene alcohol that is structurally similar to cholesterol and has a wide range of pharmacological properties, including anti-inflammatory and anti-cancer effects. In the present study, euphol suppressed TGF-β signaling by inducing TGF-β receptor movement into lipid-raft microdomains and degrading TGF-β receptors.

The role of mitochondria in statin-induced myopathy

BACKGROUND

Statins inhibit hydroxymethylglutaryl-coenzyme A reductase, decrease plasma low-density lipoprotein cholesterol and reduce cardiovascular morbidity and mortality. They can also exert adverse effects, mostly affecting skeletal muscle, ranging from mild myalgia to rhabdomyolysis.

MATERIALS AND METHODS

Based on a PubMed search until December 2014, this review summarizes studies on statin effects on muscle mitochondrial morphology and function in the context of myopathy.

RESULTS

Possible mechanisms of statin-induced myopathy include lower cholesterol synthesis and production of prenylated proteins, reduced dolichols and increased atrogin-1 expression. Statin-treated patients frequently feature decreased muscle coenzyme Q10 (CoQ10) contents, suggesting that statins might impair mitochondrial function. In cell cultures, statins diminish muscle oxygen consumption, promote mitochondrial permeability transient pore opening and generate apoptotic proteins. Animal models confirm the statin-induced decrease in muscle CoQ10, but reveal no changes in mitochondrial enzyme activities. Human studies yield contradictory results, with decreased CoQ10, elevated lipids, decreased enzyme activities in muscle and impaired maximal oxygen uptake in several but not all studies. Some patients are susceptible to statin-induced myopathy due to variations in genes encoding proteins involved in statin uptake and biotransformation such as the solute carrier organic anion transporter family member 1B1 (SLCO1B1) or cytochrome P450 (CYP2D6, CYP3A4, CYP3A5). Carriers for carnitine palmitoyltransferase II deficiency and McArdle disease also present with higher prevalence of statin-induced myopathy.

CONCLUSIONS

Despite the widespread use of statins, the pathogenesis of statin-induced myopathy remains unclear, requiring prospective randomized controlled trials with intensive phenotyping also for identifying strategies for its risk assessment, prevention and treatment.

Cardiovascular and inflammatory effects of simvastatin therapy in patients with COPD: a randomized controlled trial

Background

There is excess cardiovascular mortality in patients with chronic obstructive pulmonary disease. Aortic stiffness, an independent predictor of cardiovascular risk, and systemic and airway inflammation are increased in patients with the disease. Statins modulate aortic stiffness and have anti-inflammatory properties. A proof-of-principle, double-blind, randomized trial determined if 6 weeks of simvastatin 20 mg once daily reduced aortic stiffness and systemic and airway inflammation in patients with chronic obstructive pulmonary disease.

Methods

Stable patients (n=70) were randomized to simvastatin (active) or placebo. Pre-treatment and post-treatment aortic stiffness, blood pressure, spirometry, and circulating and airway inflammatory mediators and lipids were measured. A predefined subgroup analysis was performed where baseline aortic pulse wave velocity (PWV) was >10 m/sec.

Results

Total cholesterol dropped in the active group. There was no significant change in aortic PWV between the active group and the placebo group (−0.7 m/sec, P=0.24). In those with aortic stiffness >10 m/sec (n=22), aortic PWV improved in the active group compared with the placebo group (−2.8 m/sec, P=0.03). Neither systemic nor airway inflammatory markers changed.

Conclusion

There was a nonsignificant improvement in aortic PWV in those taking simvastatin 20 mg compared with placebo, but in those with higher baseline aortic stiffness (a higher risk group) a significant and clinically relevant reduction in PWV was shown.

Grading and interpretation of white matter hyperintensities using statistical maps

BACKGROUND AND PURPOSE

We aimed to generate rigorous graphical and statistical reference data based on volumetric measurements for assessing the relative severity of white matter hyperintensities (WMHs) in patients with stroke.

METHODS

We prospectively mapped WMHs from 2699 patients with first-ever ischemic stroke (mean age=66.8±13.0 years) enrolled consecutively from 11 nationwide stroke centers, from patient (fluid-attenuated-inversion-recovery) MRIs onto a standard brain template set. Using multivariable analyses, we assessed the impact of major (age/hypertension) and minor risk factors on WMH variability.

RESULTS

We have produced a large reference data library showing the location and quantity of WMHs as topographical frequency-volume maps. This easy-to-use graphical reference data set allows the quantitative estimation of the severity of WMH as a percentile rank score. For all patients (median age=69 years), multivariable analysis showed that age, hypertension, atrial fibrillation, and left ventricular hypertrophy were independently associated with increasing WMH (0-9.4%, median=0.6%, of the measured brain volume). For younger (≤69) hypertensives (n=819), age and left ventricular hypertrophy were positively associated with WMH. For older (≥70) hypertensives (n=944), age and cholesterol had positive relationships with WMH, whereas diabetes mellitus, hyperlipidemia, and atrial fibrillation had negative relationships with WMH. For younger nonhypertensives (n=578), age and diabetes mellitus were positively related to WMH. For older nonhypertensives (n=328), only age was positively associated with WMH.

CONCLUSIONS

We have generated a novel graphical WMH grading (Kim statistical WMH scoring) system, correlated to risk factors and adjusted for age/hypertension. Further studies are required to confirm whether the combined data set allows grading of WMH burden in individual patients and a tailored patient-specific interpretation in ischemic stroke-related clinical practice.

Pravastatin reverses obesity-induced dysfunction of induced pluripotent stem cell-derived endothelial cells via a nitric oxide-dependent mechanism

AIMS

High-fat diet-induced obesity (DIO) is a major contributor to type II diabetes and micro- and macro-vascular complications leading to peripheral vascular disease (PVD). Metabolic abnormalities of induced pluripotent stem cell-derived endothelial cells (iPSC-ECs) from obese individuals could potentially limit their therapeutic efficacy for PVD. The aim of this study was to compare the function of iPSC-ECs from normal and DIO mice using comprehensive in vitro and in vivo assays.

METHODS AND RESULTS

Six-week-old C57Bl/6 mice were fed with a normal or high-fat diet. At 24 weeks, iPSCs were generated from tail tip fibroblasts and differentiated into iPSC-ECs using a directed monolayer approach. In vitro functional analysis revealed that iPSC-ECs from DIO mice had significantly decreased capacity to form capillary-like networks, diminished migration, and lower proliferation. Microarray and ELISA confirmed elevated apoptotic, inflammatory, and oxidative stress pathways in DIO iPSC-ECs. Following hindlimb ischaemia, mice receiving intramuscular injections of DIO iPSC-ECs had significantly decreased reperfusion compared with mice injected with control healthy iPSC-ECs. Hindlimb sections revealed increased muscle atrophy and presence of inflammatory cells in mice receiving DIO iPSC-ECs. When pravastatin was co-administered to mice receiving DIO iPSC-ECs, a significant increase in reperfusion was observed; however, this beneficial effect was blunted by co-administration of the nitric oxide synthase inhibitor, N(ω)-nitro-l-arginine methyl ester.

CONCLUSION

This is the first study to provide evidence that iPSC-ECs from DIO mice exhibit signs of endothelial dysfunction and have suboptimal efficacy following transplantation in a hindlimb ischaemia model. These findings may have important implications for future treatment of PVD using iPSC-ECs in the obese population.

Fluvastatin attenuated the effect of expression of β1 integrin in PAN-treated podocytes by inhibiting reactive oxygen species

It is well accepted that β1 integrin plays a key role in maintaining normal podocytes form and functions; however, its mechanism of the potential protective effect remains unclear. Furthermore, the investigation and understanding of the non-lipid-dependent renal protection of Statins in addition to well-known lipid-lowering effect may provide the therapeutic utility and ultimately improve clinical outcome for patients with renal diseases. In the present study, we investigated the effect and mechanism of fluvastatin (FLV) on the expression of β1 integrin in puromycin aminonucleoside (PAN)-treated podocytes in vitro. Cultured human podocytes were treated with PAN, and/or different concentrations of FLV (1 × 10(-8)-1 × 10(-5 )mol/l), superoxide dismutase (SOD), or H2O2, respectively. The expression of β1 integrin and reactive oxygen species (ROS) in human podocytes under each experimental condition was evaluated by western blot, RT-PCR, and 2'7'-dichlorofluorescein 3'6'-diacetate, respectively. The viability of podocytes was also assessed by MTT colorimetry in the present study. The expression of β1 integrin was significantly decreased, and the synthesis of ROS was significantly increased in podocytes following either PAN or H2O2 treatment (p < 0.05). The up-regulation of β1 integrin and down-regulation of ROS were also observed in PAN-treated podocytes following lower concentrations of FLV or SOD treatment (p < 0.05, respectively). The cytotoxicity data derived from MTT assay revealed that lower podocyte viability was found in the presence of higher concentrations of FLV, PAN, or H2O2. Lower concentration of FLV or SOD can protect podocytes from being impaired by PAN treatment. FLV attenuated the podocyte injury induced by PAN and increased the production of β1 integrin in human podocytes in vitro. This underlying mechanism of FLV may be through inhibiting the activity of ROS in human podocytes.

The Combination of Elevated Triglycerides and Abnormal Fasting Glucose Increases Risk of Cerebral Infarction in Patients With Mild to Moderate Hypercholesterolemia

Background:

While triglycerides (TGs) and diabetes increase the risk of cardiovascular disease (CVD), their combined effects have not been quantified. We explored the combined effect of elevated TGs and glucose on CVD in a post hoc analysis of the large-scale Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA) Study. Material and Methods: In the MEGA Study, 8214 patients with mild to moderate hypercholesterolemia were randomly allocated to the diet alone group or diet plus pravastatin group and followed for 5 years. Of those, 7832 patients included in the intention-to-treat analysis were stratified into 4 groups: abnormal fasting glucose (AFG) plus high TGs, high TGs alone, AFG alone, and normal fasting glucose plus normal TGs (reference). Cox proportional hazard models were used to compare the incidence of and mortality from CVD in the 4 groups.

Results:

Incidence of CVD and coronary heart disease was significantly higher in the groups with AFG alone (hazard ratio [HR], 2.02 and 3.38; P < .01, respectively) and AFG plus high TGs (HR, 2.87 and 3.87; P < .01, respectively) than the reference group. A similar relation was found in models adjusting for high-density lipoprotein cholesterol (HDL-C). Although the incidence of cerebral infarction was significantly higher only in the group with AFG plus high TGs (HR, 2.16; P = .01), it was marginally significantly higher than the reference group after adjustment for HDL-C (HR, 1.86; P = .06). Diet plus pravastatin treatment reduced the risk of cerebral infarction by 66% in the group with AFG plus high TGs ( P = .03).

Conclusions:

Our findings contribute to the formulation of the hypothesis that patients with hypercholesterolemia having AFG plus high TGs have an increased risk of cerebral infarction. These are compatible with the result from the main study that patients with hypercholesterolemia randomized to diet plus pravastatin had a reduced risk of cerebral infarction.

Antioxidant effects of statins in patients with atherosclerotic cerebrovascular disease

BACKGROUND AND PURPOSE

Oxidative stress is involved in the pathophysiological mechanisms of stroke (e.g., atherosclerosis) and brain injury after ischemic stroke. Statins, which inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, have both pleiotropic and low-density lipoprotein (LDL)-lowering properties. Recent trials have shown that high-dose statins reduce the risk of cerebrovascular events. However, there is a paucity of data regarding the changes in the oxidative stress markers in patients with atherosclerotic stroke after statin use. This study evaluated changes in oxidative stress markers after short-term use of a high-dose statin in patients with atherosclerotic stroke.

METHODS

Rosuvastatin was administered at a dose of 20 mg/day to 99 patients who had suffered an atherosclerotic stroke and no prior statin use. Blood samples were collected before and 1 month after dosing, and the serum levels of four oxidative stress markers-malondialdehyde (MDA), oxidized LDL (oxLDL), protein carbonyl content (PCO), and 8-hydroxy-2'-deoxyguanosine (8-OHdG)-were evaluated to determine the oxidation of MDA and lipids, proteins, and DNA, respectively, at both of those time points.

RESULTS

The baseline levels and the degrees of reduction after statin use differed among the oxidative stress markers measured. MDA and PCO levels were associated with infarct volumes on diffusion-weighted imaging (r=0.551, p<0.05, and r=0.444, p=0.05, respectively). Statin use decreased MDA and oxLDL levels (both p<0.05) but not the PCO or 8-OHdG level. While the reduction in MDA levels after statin use was not associated with changes in cholesterol, that in oxLDL levels was proportional to the reductions in cholesterol (r=0.479, p<0.01), LDL (r=0.459, p<0.01), and apolipoprotein B (r=0.444, p<0.05).

CONCLUSIONS

The impact of individual oxidative stress markers differs with time after ischemic stroke, suggesting that different oxidative markers reflect different aspects of oxidative stress. In addition, short-term use of a statin exerts antioxidant effects against lipid peroxidation via lipid-lowering-dependent and -independent mechanisms, but not against protein or DNA oxidation in atherosclerotic stroke patients.

Amelioration of cisplatin-induced nephrotoxicity by statins

Objectives:

This study aimed to investigate the protective effect of simvastatin (SIM) and rosuvastatin (RST) on cisplatin (CIS)-induced nephrotoxicity.

Materials and Methods:

Adult female Wistar rats were divided into six groups: Control group (Group 1) received 0.5% sodium carboxy methyl cellulose, group 2 and group 3 received SIM and RST for 10 days, respectively, and group 4 was injected single dose of CIS (7 mg/kg, i.p.). Group 5 and 6 were treated with SIM (10 mg/kg, p.o.) and RST (10 mg/kg, p.o.) for 10 days, respectively. All groups received cisplatin on the 5^th day of treatment. Renal function tests like serum creatinine, urea, BUN, albumin, calcium, uric acid and magnesium, serum lipids, and markers of oxidative stress such as renal malondialdehyde (MDA) level and superoxide dismutase (SOD) and catalase (CAT) activities were measured. All tissues were investigated for histopathological changes.

Result:

CIS reduced the renal function, which was reflected with significant increase in serum urea, BUN, serum creatinine, uric acid and also significant decrease serum calcium, magnesium, albumin levels. In addition, cisplatin caused renal tubular damage with a higher MDA level, depletion of SOD and CAT activity, and elevation of serum lipids. SIM or RST ameliorate CIS induced renal damage due to improvement in renal function, oxidative stress, suppression of serum lipids, and histological alteration.

Conclusions:

This finding suggests that simvastatin and rosuvastatin may have a protective effect against cisplatin-induced kidney damage via amelioration of lipid peroxidation as well as due to improvement of renal function, and lipid-lowering effects.

Effects of atorvastatin and insulin in vascular dysfunction associated with type 2 diabetes

Atorvastatin and insulin have distinct mechanisms of action to improve endothelial function. Therefore, we hypothesized that atorvastatin and insulin therapies alone or in combination could have beneficial effects on endothelium-dependent vascular reactivity, oxidative stress, inflammation and metabolic parameters in Goto-Kakizaki (GK) rats, a model of type 2 diabetes fed with atherogenic diet (GKAD). In parallel with the development of diabetes and lipid profile, the generation of oxidative stress was determined by measurement of lipid peroxides and oxidized proteins and the presence of inflammation was evaluated by assessing C-reactive protein (CRP). Additionally, endothelial dependent and independent vascular sensitivity to acetylcholine and sodium nitroprusside were evaluated. GKAD showed increased carbonyl stress, inflammation, fasting glycemia, dyslipidemia and endothelial dysfunction when compared to control GK rats. Noteworthy, supplementation with insulin deteriorated endothelial dysfunction while atorvastatin induced an improvement. Atorvastatin and insulin therapies in combination improved metabolic parameters, CRP levels and insulin resistance indexes and ameliorated endothelial dysfunction in GKAD rats while they were unable to reduce urinary 8-isoprostranes and plasma carbonyl compounds. The therapeutic association of atorvastatin and insulin provided a better metabolic control with a reduction in endothelial dysfunction in GKAD rats by a mechanism that involves an improvement in systemic inflammation.

Croton schiedeanus Schltd prevents experimental hypertension in rats induced by nitric oxide deficit

Croton schiedeanus Schltd (N.V.: "almizclillo") is a plant used in traditional medicine as an antihypertensive in Colombia. It contains flavonoid, diterpenoid and fenilbutanoid metabolites that have vasodilatation effects linked to the NO/cGMP pathway. This work aimed to assess the capacity of a 96% EtOH extract to prevent the hypertension induced by nitric oxide (NO) deficiency in rats. The NO synthase inhibitor L-NAME (10 mg/kg/d, i.p) was administered during five weeks to three groups of rats (6-7 animals): C. Schiedeanus (200 mg/kg/d, p.o), enalapril (reference, 10 mg/kg/d, p.o) and vehicle (control: olive oil 1 ml/kg/d, p.o). In addition, the blank group received only vehicle. The arterial blood pressure (BP) and heart rate (HR) were measured daily for six weeks. After sacrificing the animals, the aortic rings were isolated, contraction was triggered with phenylephrine (PE 10-6 M) and relaxant responses were achieved with cumulative concentrations of acetylcholine (ACh, 10-10 - 10-4 M). L-NAME increased the systolic arterial pressure in the control group, attaining mean values of 131 mm Hg at week 5, whereas the C. schiedeanus, enalapril and blank groups maintained blood pressure under 100 mm Hg. The capacity of PE to contract aortic rings was greater in the C. schiedeanus, enalapril and blank groups than in the control group (2157, 2005, 1910 and 1646 mg, respectively). The pEC50 values for ACh were as follows: C. Schiedeanus (6.89) >enalapril (6.39) > blank (5.68) > control (5.09). These results give support to C. Schiedeanus as a natural antihypertensive source.

Simvastatin inhibits smoke-induced airway epithelial injury: implications for COPD therapy

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death. The statin drugs may have therapeutic potential in respiratory diseases such as COPD, but whether they prevent bronchial epithelial injury is unknown. We hypothesised that simvastatin attenuates acute tobacco smoke-induced neutrophilic lung inflammation and airway epithelial injury. Spontaneously hypertensive rats were given simvastatin (20 mg·kg(-1) i.p.) daily for either 7 days prior to tobacco smoke exposure and during 3 days of smoke exposure, or only during tobacco smoke exposure. Pretreatment with simvastatin prior to and continued throughout smoke exposure reduced the total influx of leukocytes, neutrophils and macrophages into the lung and airways. Simvastatin attenuated tobacco smoke-induced cellular infiltration into lung parenchymal and airway subepithelial and interstitial spaces. 1 week of simvastatin pretreatment almost completely prevented smoke-induced denudation of the airway epithelial layer, while simvastatin given only concurrently with the smoke exposure had no effect. Simvastatin may be a novel adjunctive therapy for smoke-induced lung diseases, such as COPD. Given the need for statin pretreatment there may be a critical process of conditioning that is necessary for statins' anti-inflammatory effects. Future work is needed to elucidate the mechanisms of this statin protective effect.

Enhancement of autophagy by simvastatin through inhibition of Rac1-mTOR signaling pathway in coronary arterial myocytes

BACKGROUND/AIMS

In addition to their action of lowering blood cholesterol levels, statins modulate biological characteristics and functions of arterial myocytes such as viability, proliferation, apoptosis, survival and contraction. The present study tested whether simvastatin, as a prototype statin, enhances autophagy in coronary arterial myocytes (CAMs) to thereby exert their beneficial effects in atherosclerosis.

METHODS AND RESULTS

Using flow cytometry, we demonstrated that simvastatin significantly increased the autophagsome formation in CAMs. Western blot analysis confirmed that simvastatin significantly increased protein expression of typical autophagy markers LC3B and Beclin1 in these CAMs. Confocal microscopy further demonstrated that simvastatin increased fusion of autophagosomes with lysosomes, which was blocked by autophagy inhibitor 3-methyladenine or silencing of Atg7 genes. Simvastatin reduced mammalian target of rapamycin (mTOR) activity, which was reversed by Rac1-GTPase overexpression and the mTOR agonist phosphatidic acid. Moreover, both Rac1-GTPase overexpression and activation of mTOR by phosphatidic acid drastically blocked simvastatin-induced autophagosome formation in CAMs. Interestingly, simvastatin increased protein expression of a contractile phenotype marker calponin in CAMs, which was blocked by autophagy inhibitor 3-methyladenine. Simvastatin markedly reduced proliferation of CAMs under both control and proatherogenic stimulation. However, this inhibitory effect of simvastatin on CAM proliferation was blocked by by autophagy inhibitor 3-methyladenine or silencing of Atg7 genes. Lastly, animal experiments demonstrated that simvastatin increased protein expression of LC3B and calponin in mouse coronary arteries.

CONCLUSION

Our results indicate that simvastatin inhibits the Rac1-mTOR pathway and thereby increases autophagy in CAMs which may stabilize CAMs in the contractile phenotype to prevent proliferation and growth of these cells.

Statin use and peripheral blood progenitor cells mobilization in patients with multiple myeloma

PURPOSE

Statins have beneficial effects in patients after myocardial infarction and at least part of the benefit results from mobilization of marrow endothelial progenitors to repopulate damaged myocardial tissues. This study examines if statins may have the same effect in mobilizing marrow progenitors to be harvested and subsequently used in high-dose chemotherapy with progenitor cell rescue in multiple myeloma.

METHODS

From 2006 to 2012, 86 patients with multiple myeloma were mobilized with the use of G-CSF and were retrospectively analyzed. Patients with other malignancies or mobilized with the use of chemotherapy or with plerixafor were excluded.

RESULTS

The median age of the patients was 60 years. 72 patients had received one line of chemotherapy and 14 patients two or more lines of chemotherapy. Twenty patients were taking statins at the time of the harvest while 66 patients were not. In the group of patients taking statins the success rate of first leukapheresis (obtaining the target number of 4 × 10(6) CD34+ cells/kg) was 85 % while in the group not taking statins this rate was 63.6 %. Despite the comparatively small number of patients this difference approached statistical significance (χ (2) = 0.07).

CONCLUSION

This retrospective analysis of 86 patients shows for the first time a possible benefit of statins for peripheral blood progenitor cells mobilization in patients with multiple myeloma. Larger studies would be required to clarify the issue. If their effectiveness is confirmed, statins could be a safe and cheaper addition to chemotherapy and plerixafor for peripheral hematopoietic stem cell mobilization.

Effects of nutritional and excessive levels of selenium on red blood cells of rats fed a high cholesterol diet

In this study, we investigated the effects of selenium (Se) on the properties of erythrocytes and atherogenic index in the presence and absence of high cholesterol diet (HCD). The effect of selected two different doses (1 μg and 50 μg Se/kg/body weight) on HCD-induced oxidative stress was investigated. The hemolysis of the erythrocytes of the HCD rats as well as by high levels of selenium or their combination was markedly increased. Likewise, atherogenic index and plasma glutathione peroxidase (GPx) activity were significantly increased in the same groups of rats compared to control ones. In contrast, paraoxonase activity, glutathione levels and protein thiol levels, catalase, GPx, and superoxide dismutase activities were significantly decreased in rats that received the HCD, high selenium dose, or their combination. Malondialdehyde and protein carbonyl levels in the plasma and red blood cells were significantly increased by HCD and high selenium dose administration. Co-administration of selenium at low dose with or without an HCD restored all of the investigated parameters to near-normal values. The results of this study suggest that excess selenium administration with HCD worsens the atherogenic index and enhances formation of oxidized red blood cells. At dosage levels in the nutritional range such as 1 μg Se/kg body weight, selenium ameliorates the atherogenic index and preserves the antioxidant capacity of the erythrocytes.

Attenuation by statins of membrane raft-redox signaling in coronary arterial endothelium

Membrane raft (MR)-redox signaling platforms associated with NADPH oxidase are involved in coronary endothelial dysfunction. Here, we studied whether statins interfere with the formation of MR-redox signaling platforms to protect the coronary arterial endothelium from oxidized low-density lipoprotein (OxLDL)-induced injury and from acute hypercholesterolemia. In cultured human coronary arterial endothelial cells, confocal microscopy detected the formation of an MRs clustering when they were exposed to OxLDL, and such MR platform formation was inhibited markedly by statins, including pravastatin and simvastatin. In these MR clusters, NADPH oxidase subunits gp91(phox) and p47(phox) were aggregated and were markedly blocked by both statins. In addition, colocalization of acid sphingomyelinase (ASM) and ceramide was induced by OxLDL, which was blocked by statins. Electron spin resonance spectrometry showed that OxLDL-induced superoxide (O2(.-)) production in the MR fractions was substantially reduced by statins. In coronary artery intima of mice with acute hypercholesterolemia, confocal microscopy revealed a colocalization of gp91(phox), p47(phox), ASM, or ceramide in MR clusters. Such colocalization was rarely observed in the arteries of normal mice or significantly reduced by pretreatment of hypercholesterolemic mice with statins. Furthermore, O2(.-) production in situ was 3-fold higher in the coronary arteries from hypercholesterolemic mice than in those from normal mice, and such increase was inhibited by statins. Our results indicate that blockade of MR-redox signaling platform formation in endothelial cell membrane may be another important therapeutic mechanism of statins in preventing endothelial injury and atherosclerosis and may be associated with their direct action on membrane cholesterol structure and function.

Pleiotropic effects of calcium channel blockers

Clinical trials have reported reduced cardiovascular events with certain antihypertensive agents at a rate that could not be predicted by changes in brachial arterial pressure alone. These findings may be explained, in part, by pleiotropic effects of these agents and modulation of central blood pressures. This review focuses on the mechanisms by which calcium channel blockers exert pleiotropic effects, both alone and in combination with statins and inhibitors of the renin-angiotensin system. The essential role of nitric oxide (NO) in maintaining endothelial function and the relationship between NO and reactive oxygen species are discussed in the context of the etiology of hypertension. The importance of managing global cardiovascular risk is emphasized, as hypertension commonly clusters with dyslipidemia and loss of glucose control. From a mechanistic viewpoint, these risk factors contribute to endothelial dysfunction, oxidative stress, and inflammation in a synergistic fashion. A greater understanding of the mechanisms of actions of these cardiovascular agents may lead to more effective drug combinations, to the benefit of individual patients. Furthermore, by elucidating the biological mechanisms by which cardiovascular risk factors lead to vascular injury, we may highlight common pathways and identify novel therapeutic targets.

Caveolin-1-eNOS/Hsp70 interactions mediate rosuvastatin antifibrotic effects in neonatal obstructive nephropathy

Evidence suggesting that statins may contribute to renoprotection has been provided in experimental and clinical studies. Statins restore endothelial nitric oxide (NO) levels by mechanisms including up-regulation of endothelial NO synthase (eNOS) expression. Caveolin-1/eNOS interaction is essential preventing inadequate NO levels. Here, we evaluated whether caveolin-1 associated with eNOS/Hsp70 expression may be involved in the mechanism by which rosuvastatin exerts tubulointerstitial fibrosis protection in neonatal unilateral ureteral obstruction (UUO). Neonatal rats subjected to UUO within 2 days of birth and controls were treated daily with vehicle or rosuvastatin (10 mg/kg/day) by oral gavage for 14 days. After UUO, morphometric evaluation of interstitial fibrosis showed increased interstitial volume (Vv) associated with reduced NO availability, increased mRNA and protein caveolin-1 expression as well as downregulation eNOS and heat shock protein 70 (Hsp70) expression. Conversely, rosuvastatin treatment attenuated the fibrotic response linked to high NO availability, decreased mRNA and protein caveolin-1 expression, and marked upregulation of eNOS and Hsp70 expression at transcriptional and posttranscriptional levels. Moreover, protein-protein interactions determined by immunoprecipitation and by immunofluorescence co-localization have shown decreased caveolin-1/eNOS as well as increased Hsp70/eNOS interaction, after rosuvastatin treatment. A dose dependent effect of rosuvastatin on decreased caveolin-1 expression was shown in control cortex. In conclusion, our data suggest that statins contribute to the protection against tubulointerstitial fibrosis injury in neonatal early kidney obstruction by increased NO availability, involving interaction of up-regulated eNOS/Hsp70 and down-regulated caveolin-1.

Reactive oxygen and nitrogen species in pathogenesis of vascular complications of diabetes

Macrovascular and microvascular diseases are currently the principal causes of morbidity and mortality in subjects with diabetes. Disorders of the physiological signaling functions of reactive oxygen species (superoxide and hydrogen peroxide) and reactive nitrogen species (nitric oxide and peroxynitrite) are important features of diabetes. In the absence of an appropriate compensation by the endogenous antioxidant defense network, increased oxidative stress leads to the activation of stress-sensitive intracellular signaling pathways and the formation of gene products that cause cellular damage and contribute to the vascular complications of diabetes. It has recently been suggested that diabetic subjects with vascular complications may have a defective cellular antioxidant response against the oxidative stress generated by hyperglycemia. This raises the concept that antioxidant therapy may be of great benefit to these subjects. Although our understanding of how hyperglycemia-induced oxidative stress ultimately leads to tissue damage has advanced considerably in recent years, effective therapeutic strategies to prevent or delay the development of this damage remain limited. Thus, further investigation of therapeutic interventions to prevent or delay the progression of diabetic vascular complications is needed.

Microvascular responsiveness in obesity: implications for therapeutic intervention

Obesity has detrimental effects on the microcirculation. Functional changes in microvascular responsiveness may increase the risk of developing cardiovascular complications in obese patients. Emerging evidence indicates that selective therapeutic targeting of the microvessels may prevent life-threatening obesity-related vascular complications, such as ischaemic heart disease, heart failure and hypertension. It is also plausible that alterations in adipose tissue microcirculation contribute to the development of obesity. Therefore, targeting adipose tissue arterioles could represent a novel approach to reducing obesity. This review aims to examine recent studies that have been focused on vasomotor dysfunction of resistance arteries in obese humans and animal models of obesity. Particularly, findings in coronary resistance arteries are contrasted to those obtained in other vascular beds. We provide examples of therapeutic attempts, such as use of statins, ACE inhibitors and insulin sensitizers to prevent obesity-related microvascular complications. We further identify some of the important challenges and opportunities going forward.

LINKED ARTICLES

This article is part of a themed section on Fat and Vascular Responsiveness. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-3.

Differentially expressed genes in human peripheral blood as potential markers for statin response

There is a considerable inter-individual variation in response to statin therapy and one third of patients do not meet their treatment goals. We aimed to identify differentially expressed genes that might be involved in the effects of statin treatment and to suggest potential markers to guide statin therapy. Forty-six healthy Korean subjects received atorvastatin; their whole-genome expression profiles in peripheral blood were analyzed before and after atorvastatin administration in relation with changes in lipid profiles. The expression patterns of the differentially expressed genes were also compared with the data of familial hypercholesterolemia (FH) patients and controls. Pairwise comparison analyses revealed differentially expressed genes involved in diverse biological processes and molecular functions related with immune responses. Atorvastain mainly affected antigen binding, immune or inflammatory response including interleukin pathways. Similar expression patterns of the genes were observed in patients with FH and controls. The Charcol-Leyden crystal (CLC), CCR2, CX3CR1, LRRN3, FOS, LDLR, HLA-DRB1, ERMN, and TCN1 genes were significantly associated with cholesterol levels or statin response. Interestingly, the CLC gene, which was significantly altered by atorvastatin administration and differentially expressed between FH patients and controls, showed much bigger change in high-responsive group than in low-responsive group. We identified differentially expressed genes that might be involved in mechanisms underlying the known pleiotropic effects of atorvastatin, baseline cholesterol levels, and drug response. Our findings suggest CLC as a new candidate marker for statin response, and further validation is needed.

Statins prevent tissue factor induction by protease-activated receptors 1 and 2 in human umbilical vein endothelial cells in vitro

BACKGROUND

Protease-activated receptors (PARs) are G-protein-coupled receptors that function in hemostasis and thrombosis, as well as in the inflammatory and proliferative responses triggered by tissue injury. We have previously shown that PAR1 or PAR2 occupancy by specific PAR-agonist peptides (PAR-APs) induces tissue factor (TF) expression in human umbilical vein endothelial cells (HUVECs), where TF regulation by PAR1 (but not by PAR2) requires intact endothelial caveolin-enriched membrane microdomains in which PAR1 and caveolin-1 associate.

OBJECTIVES

The aim of this study was to determine the effects of cholesterol-lowering agents (statins) and cholesterol-loading lipoprotein on PAR1-AP-mediated and PAR2-AP-mediated TF induction in HUVECs.

RESULTS

Statins completely prevented TF induction by PAR-APs in an isoprenoid-independent manner, induced the delocalization of PAR1 from caveolin-enriched membrane microdomains without affecting PAR1 mRNA, and decreased PAR2 mRNA and protein levels. Statins also prevented PAR-AP-mediated extracellular signal-related kinase 1/2 activation, which is crucial for TF induction. The redistribution of PAR1 is accompanied by the relocation of the membrane microdomain-associated G-protein α, caveolin-1, and Src, which we previously showed to play a key role in signal transduction and TF induction. Conversely, cholesterol loading potently amplified PAR1-AP-induced TF, probably as a result of the increased abundance of PAR1 and the Src and G-protein α signaling molecules in the caveolin-1-enriched fraction, without affecting PAR1 mRNA.

CONCLUSIONS

As PARs have important functions in hemostasis, cancer, thrombosis, and inflammatory processes, our findings that statins prevent TF induction by PAR-APs altering the membrane localization of PAR1 and the expression of PAR2 suggest that they may provide health benefits other than reducing atherosclerosis.

Treatment with pravastatin and fenofibrate improves atherogenic lipid profiles but not inflammatory markers in ACTG 5087

OBJECTIVES

Statins and fibrates alter lipids, apolipoproteins and inflammatory markers in persons without HIV. The objective of this study was to evaluate changes in lipoproteins, apolipoproteins and other markers of inflammation with the use of pravastatin and fenofibrate.

DESIGN

Evaluation of participants in ACTG A5087, a randomized trial of pravastatin 40 mg/day or fenofibrate 200 mg/day for the treatment of dyslipidemia. Participants that failed single-agent therapy at week 12 were given the combination.

METHODS

Participants with available specimens were tested for apolipoproteins A1 and B, adiponectin, plasminogen-activator inhibitor type 1 (PAI-1), P-selectin, and high-sensitivity C-reactive protein (hs-CRP).

RESULTS

74 participants (37 per randomized arm) received either pravastatin or fenofibrate for 12 weeks with 60 receiving combination treatment from weeks 12-48. There were no significant changes in hs-CRP, PAI-1, and P-selectin. From baseline to week 12, the median Apo B levels (-8 mg/dL, P=0.01 for fenofibrate and -27 mg/dL, P<0.01 for pravastatin) and ApoB/A1 ratios (-0.16, P<0.01 for both arms) significantly decreased. From baseline to week 48, median adiponectin (-1 ng/dL, P<0.01), Apo B (-22 mg/dL, P<0.01) and Apo B/A1 ratios (-0.2, P<0.01) all decreased in those who went on combination therapy, whereas Apo A1 (9.5 mg/dL, P=0.01) levels increased.

CONCLUSION

Treatment with pravastatin or fenofibrate improves the atherogenic lipid profile within the first 12 weeks and is sustained through 48 weeks with combination therapy. Adiponectin levels decrease with lipid-lowering therapy. However, markers of inflammation and platelet activation were not appreciably changed suggesting that the biologic properties of these agents differ in persons with HIV infection.