Translating the effects of statins: from redox regulation to suppression of vascular wall inflammation

Targeting endothelial KCa channels in vivo restores arterial and endothelial function in type 2 diabetic rats

OBJECTIVE

This study tested the hypothesis that administration of the KCa channel activator SKA-31 restores endothelium-dependent vasodilation in vivo in Type 2 Diabetic (T2D) rats.

BACKGROUND

Acute treatment of isolated resistance arteries from T2D rats and humans with SKA-31 significantly improved endothelium-dependent vasodilation. However, it is unknown whether these in situ actions translate to intact vascular beds in vivo.

METHODS

Male Sprague Dawley (SD) and T2D Goto-Kakizaki (GK) rats (26-32 weeks of age) were injected intraperitoneally with either drug vehicle or 10 mg/kg SKA-31. Doppler ultrasound imaging was used to record reactive hyperemia/flow-mediated dilation (FMD) in the femoral artery following release of an occlusion cuff on the distal hind limb, along with diameter changes in the left main coronary artery in response to inhaled isoflurane (2 % → 5 %).

RESULTS

Vehicle treated SD rats exhibited a robust and reversible FMD response, the magnitude and time course of which did not differ in SD rats treated with SKA-31. In contrast, only a weak FMD response was observed in vehicle-treated T2D GK rats, whereas prior SKA-31 administration restored FMD to the level observed in control SD rats. Exposure of SD rats to 5 % isoflurane caused robust coronary artery dilation, which was not altered by prior treatment with SKA-31. In T2D GK rats, 5 % isoflurane inhalation alone did not increase coronary artery diameter, however, a strong vasodilatory response was observed following SKA-31 treatment. SKA-31 administration did not modify intrinsic heart rate responses in either protocol.

CONCLUSIONS

Enhancement of KCa channel activity in vivo restores endothelium-dependent vasodilation in T2D rats that exhibit peripheral endothelial dysfunction.

Mitigating Vascular Inflammation by Mimicking AIBP Mechanisms: A New Therapeutic End for Atherosclerotic Cardiovascular Disease

Atherosclerosis, characterized by the accumulation of lipoproteins and lipids within the vascular wall, underlies a heart attack, stroke, and peripheral artery disease. Endothelial inflammation is the primary component driving atherosclerosis, promoting leukocyte adhesion molecule expression (e.g., E-selectin), inducing chemokine secretion, reducing the production of nitric oxide (NO), and enhancing the thrombogenic potential. While current therapies, such as statins, colchicine, anti-IL1β, and sodium-glucose cotransporter 2 (SGLT2) inhibitors, target systemic inflammation, none of them addresses endothelial cell (EC) inflammation, a critical contributor to disease progression. Targeting endothelial inflammation is clinically significant because it can mitigate the root cause of atherosclerosis, potentially preventing disease progression, while reducing the side effects associated with broader anti-inflammatory treatments. Recent studies highlight the potential of the APOA1 binding protein (AIBP) to reduce systemic inflammation in mice. Furthermore, its mechanism of action also guides the design of a potential targeted therapy against a particular inflammatory signaling pathway. This review discusses the unique advantages of repressing vascular inflammation or enhancing vascular quiescence and the associated benefits of reducing thrombosis. This approach offers a promising avenue for more effective and targeted interventions to improve patient outcomes.

INOVASIA Study: A Multicenter Randomized Clinical Trial of Pravastatin to Prevent Preeclampsia in High-Risk Patients

OBJECTIVE

Our objective was to determine if treatment with pravastatin prevents preeclampsia in pregnant patients at risk of preeclampsia.

MATERIALS AND METHODS

The study was performed in four major tertiary hospitals in Surabaya, Bandung, and Makassar between 2017 and 2021. Pregnant women at high risk of developing preeclampsia were recruited and randomized into an intervention group and control group. The control group received low-dose aspirin (80 mg) and calcium (1 g) daily, while the intervention group received additional pravastatin (20 mg twice daily) starting from 14 to 20 weeks' gestation until delivery. The pregnancy was followed until delivery, and the clinical data were collected. The primary outcome was the occurrence of preeclampsia.

RESULT

A total of 173 people participated in this study, including 86 in the control group and 87 in the pravastatin group. The pravastatin group had a significantly lower rate of preterm preeclampsia (13.8 vs. 26.7%; p = 0.034; odds ratio [OR] = 0.034, 95% confidence interval [CI] = 0.202-0.905) and preterm birth (16.1 vs. 36%; p = 0.003; OR = 0.340, 95% CI = 0.165-0.7), mostly indicated preterm birth. Preeclampsia occurred later in the pravastatin group than in the control group (36.39 + 2.32 vs. 34.89 + 3.38 weeks, p = 0.048). Overall, the pravastatin group showed better perinatal outcomes. Neonates with low Apgar scores (<7) at 1 minute (5.7 vs. 25.6%, p = 0.000) and 5 minutes (2.3 vs. 25.6%, p = 0.028) were significantly less common in the pravastatin group. Additionally, the rate of low birthweight babies (<2,500 g) was lower in the pravastatin group (27.6 vs. 40.7%; p = 0.069).

CONCLUSION

Pravastatin (20 mg bid) significantly reduces the risk of preterm preeclampsia and preterm birth in women at a high risk of developing preeclampsia.

KEY POINTS

· This is an open-label multicenter RCT to evaluate pravastatin effect to prevent preeclampsia.. · Pravastatin significantly reduces the risk of preterm preeclampsia (PE) and preterm birth in high risk PE women.. · Pravastatin had a beneficial effect on perinatal outcomes, including Apgar scores and birth weight..

Statins and renal cell carcinoma: Antitumor activity and influence on cancer risk and survival

Statins are commonly prescribed to reduce plasma cholesterol levels and risk of cardiovascular events and mortality. Statin exposure may have cancer-preventive properties in some solid tumors, including Renal Cell Carcinoma (RCC). Emerging evidences show that statins can inhibit RCC cell growth by inducing cell cycle arrest and apoptosis in a dose- and time-dependent manner. In addition, statins inhibit the phosphorylation of AKT, mammalian target of rapamycin (mTOR), and ERK leading to reduced motility of RCC cells. Interestingly, the potential impact of concomitant statin intake has been recently evaluated in RCC patients treated by targeted therapy or immunotherapy. In this review, we illustrate the most recent data on the preclinical activity of statins in Renal Cell Carcinoma models and discuss the impact of their use on the prevention and survival of patients affected by this tumor.

Statins and Peripheral Arterial Disease: A Narrative Review

Peripheral arterial disease (PAD) is a highly prevalent atherosclerotic condition. In patients with PAD, the presence of intermittent claudication leads to a deterioration in quality of life. In addition, even in asymptomatic cases, patients with PAD are at high risk of cardiac or cerebrovascular events. Treatment of PAD is based on lifestyle modifications; regular exercise; smoking cessation; and control of cardiovascular risk factors, including hypercholesterolemia. A growing number of studies have shown that statins reduce cardiovascular risk and improve symptoms associated with PAD. Current guidelines recommend the use of statins in all patients with PAD in order to decrease cardiovascular events and mortality. However, the prescribing of statins in patients with PAD is lower than in those with coronary heart disease. This review provides relevant information from the literature that supports the use of statins in patients with PAD and shows their potential benefit in decreasing lower limb complications as well as cardiovascular morbidity and mortality.

Simvastatin does not alleviate muscle pathology in a mouse model of Duchenne muscular dystrophy

Background

Duchenne muscular dystrophy (DMD) is an incurable disease, caused by the mutations in the DMD gene, encoding dystrophin, an actin-binding cytoskeletal protein. Lack of functional dystrophin results in muscle weakness, degeneration, and as an outcome cardiac and respiratory failure. As there is still no cure for affected individuals, the pharmacological compounds with the potential to treat or at least attenuate the symptoms of the disease are under constant evaluation. The pleiotropic agents, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, known as statins, have been suggested to exert beneficial effects in the mouse model of DMD. On the other hand, they were also reported to induce skeletal-muscle myopathy. Therefore, we decided to verify the hypothesis that simvastatin may be considered a potential therapeutic agent in DMD.

Methods

Several methods including functional assessment of muscle function via grip strength measurement, treadmill test, and single-muscle force estimation, enzymatic assays, histological analysis of muscle damage, gene expression evaluation, and immunofluorescence staining were conducted to study simvastatin-related alterations in the mdx mouse model of DMD.

Results

In our study, simvastatin treatment of mdx mice did not result in improved running performance, grip strength, or specific force of the single muscle. Creatine kinase and lactate dehydrogenase activity, markers of muscle injury, were also unaffected by simvastatin delivery in mdx mice. Furthermore, no significant changes in inflammation, fibrosis, and angiogenesis were noted. Despite the decreased percentage of centrally nucleated myofibers in gastrocnemius muscle after simvastatin delivery, no changes were noticed in other regeneration-related parameters. Of note, even an increased rate of necrosis was found in simvastatin-treated mdx mice.

Conclusion

In conclusion, our study revealed that simvastatin does not ameliorate DMD pathology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13395-021-00276-3.

Atorvastatin Reduces Circulating S100A12 Levels in Patients with Carotid Atherosclerotic Plaques - A Link with Plaque Inflammation

Aims: Inflammation is involved in various processes of atherosclerosis development. Serum C-reactive protein (CRP) levels, a predictor for cardiovascular risk, are reportedly reduced by statins. However, several studies have demonstrated that CRP is a bystander during atherogenesis. While S100A12 has been focused on as an inflammatory molecule, it remains unclear whether statins affect circulating S100A12 levels. Here, we investigated whether atorvastatin treatment affected S100A12 and which biomarkers were correlated with changes in arterial inflammation.

Methods: We performed a prospective, randomized open-labeled trial on whether atorvastatin affected arterial (carotid and thoracic aorta) inflammation using¹⁸fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) and inflammatory markers. Thirty-one statin-naïve patients with carotid atherosclerotic plaques were randomized to either a group receiving dietary management (n=15) or one receiving atorvastatin (10mg/day,n=16) for 12weeks.¹⁸F-FDG-PET/CT and flow-mediated vasodilation (FMD) were performed, the latter to evaluate endothelial function.

Results: Atorvastatin, but not the diet-only treatment, significantly reduced LDL-cholesterol (LDL-C, -43%), serum CRP (-37%) and S100A12 levels (-28%) and improved FMD (+38%).¹⁸F-FDG-PET/CT demonstrated that atorvastatin, but not the diet-only treatment, significantly reduced accumulation of¹⁸F-FDG in the carotid artery and thoracic aorta. A multivariate analysis revealed that reduction in CRP, S100A12, LDL-C, oxidized-LDL, and increase in FMD were significantly associated with reduced arterial inflammation in the thoracic aorta, but not in the carotid artery.

Conclusions: Atorvastatin treatment reduced S100A12/CRP levels, and the changes in these circulating markers mirrored the improvement in arterial inflammation. Our observations suggest that S100A12 may be an emerging therapeutic target for atherosclerosis.

Simvastatin attenuates spatial memory impairment via inhibiting microgliosis and apoptotic cell death against ethanol induced neurotoxicity in the developing rat hippocampus

Ethanol is associated with oxidative stress. Exposure to ethanol during childhood may lead to neurological disorders. Congenital disorders induced by alcohol are mainly caused by an oxidative-inflammatory cascade due to extensive apoptotic neurodegeneration in the brain, particularly in the hippocampus. Simvastatin, which acts as an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA), is widely used to manage cardiovascular diseases. Recently, the neuroprotective effects of simvastatin against nervous system disorders have been introduced. In this study, we examined the protective effects of simvastatin on ethanol-related neurotoxicity in the hippocampus of rat pups. Ethanol (5.27 g/kg) in a milk solution (27.8 mL/kg) was administered to male rat pups via intragastric intubation at 2-10 days after birth. Also, 10 and 20 mg/kg of simvastatin were injected to the animals. By using Morris water maze task, the hippocampus-dependent memory and spatial learning was evaluated 36 days after birth. An ELISA assay was performed to investigate the antioxidant and anti-inflammatory effects of simvastatin by measuring the levels of tumor necrosis factor-α (TNF-α), and antioxidant enzymes. To assess the expression levels of Iba1 immunohistochemical staining and caspase-3 immunofluorescence staining was performed. The current study demonstrated that administration of simvastatin significantly attenuates spatial memory impairment (P < 0.01) after ethanol neurotoxicity. Also simvastatin could considerably increase the total superoxide dismutaseand glutathione levels (P < 0.01). Moreover, it was associated with a greater reduction in malondialdehyde (P < 0.05) and TNF-α levels, compared to the ethanol group (P < 0.01). Furthermore, in the simvastatin group, the hippocampal level of caspase-3 and the level of Iba1-positive cells, reduced (P < 0.01). This study demonstrated that apoptotic signaling, mediated by the oxidative-inflammatory cascade, could be inhibited by simvastatin in rat pups with ethanol exposure in the postnatal period.

Atorvastatin and pravastatin stimulate nitric oxide and reactive oxygen species generation, affect mitochondrial network architecture and elevate nicotinamide N-methyltransferase level in endothelial cells

Statins belong to the most often prescribed medications, which efficiently normalise hyperlipidaemia and prevent cardiovascular complications in obese and diabetic patients. However, beside expected therapeutic results based on the inhibition of 3-hydroxyl-3-methylglutaryl-CoA reductase, these drugs exert multiple side effects of poorly understood characteristic. In this study, side effects of pravastatin and atorvastatin on EA.hy926 endothelial cell line were investigated. It was found that both statins activate proinflammatory response, elevate nitric oxide and reactive oxygen species (ROS) generation and stimulate antioxidative response in these cells. Moreover, only slight stimulation of the mitochondrial biogenesis and significant changes in the mitochondrial network organisation have been noted. Although biochemical bases behind these effects are not clear, they may partially be explained as an elevation of AMP-activated protein kinase (AMPK) activity and an increased activating phosphorylation of sirtuin 1 (Sirt1), which were observed in statins-treated cells. In addition, both statins increased nicotinamide N-methyltransferase (NNMT) protein level that may explain a reduced fraction of methylated histone H3. Interestingly, a substantial reduction of the total level of histone H3 in cells treated with pravastatin but not atorvastatin was also observed. These results indicate a potential additional biochemical target for statins related to reduced histone H3 methylation due to increased NNMT protein level. Thus, NNMT may directly modify gene activity.

Grape juice attenuates left ventricular hypertrophy in dyslipidemic mice

OBJECTIVE

We evaluated the effects of grape juice (Vitis labrusca L.) on dyslipidemia, resistance to insulin, and left ventricular hypertrophy (LVH) in mice homozygous for the absence of the LDL receptor gene (LDLr -/-) under a hyperlipidemic diet.

METHODOLOGY

We divided 30 male mice (3 months old) into three groups (n = 10); the HL group was fed a high-fat diet, the HLU group received a high-fat diet and 2 g/kg/day of grape juice, and the HLS group was fed a high-fat diet and simvastatin (20 mg/kg/day). We assessed the blood pressure profile of the mice. We also determined the levels of C-reactive protein (CRP) and lipid profile, glycemic and insulinemic profiles, and calculated the HOMA-IR. Cardiomyocyte hypertrophy, interstitial collagen deposit, and the expression of CD40 ligand (CD40L) and metalloproteinases 2 and 9 were assessed immunohistologically.

RESULTS

After 60 days, the mice treated with grape juice showed similar results as those of the group treated with simvastatin. The use of grape fruit attenuated dyslipidemia and insulin resistance and significantly increased the levels of high cholesterol density lipoproteins (HDLc). The antioxidant potential of phenolic compounds associated with the increase in HDLc levels in the mice of the HLU group prevented the development of LVH and arterial hypertension since it inhibited the inflammatory response induced by the CD40 pathway and its ligand CD40L. Consequently, there was a lower expression of MMP-2 and MMP-9 and lower serum levels of CRP.

CONCLUSION

Grape juice has a hypolipidemic and cardiac protective potential, presenting a similar effect as that of simvastatin through a direct antioxidant action of phenolic compounds, or indirectly, via antioxidant action and anti-inflammatory activity of the HDLc. These results suggest that grape juice is a functional food possessing a high potential to prevent cardiovascular diseases.

Simvastatin provides long-term improvement of left ventricular function and prevents cardiac fibrosis in muscular dystrophy

Duchenne muscular dystrophy (DMD), caused by absence of the protein dystrophin, is a common, degenerative muscle disease affecting 1:5000 males worldwide. With recent advances in respiratory care, cardiac dysfunction now accounts for 50% of mortality in DMD. Recently, we demonstrated that simvastatin substantially improved skeletal muscle health and function in mdx (DMD) mice. Given the known cardiovascular benefits ascribed to statins, the aim of this study was to evaluate the efficacy of simvastatin on cardiac function in mdx mice. Remarkably, in 12‐month old mdx mice, simvastatin reversed diastolic dysfunction to normal after short‐term treatment (8 weeks), as measured by echocardiography in animals anesthetized with isoflurane and administered dobutamine to maintain a physiological heart rate. This improvement in diastolic function was accompanied by increased phospholamban phosphorylation in simvastatin‐treated mice. Echocardiography measurements during long‐term treatment, from 6 months up to 18 months of age, showed that simvastatin significantly improved in vivo cardiac function compared to untreated mdx mice, and prevented fibrosis in these very old animals. Cardiac dysfunction in DMD is also characterized by decreased heart rate variability (HRV), which indicates autonomic function dysregulation. Therefore, we measured cardiac ECG and demonstrated that short‐term simvastatin treatment significantly increased heart rate variability (HRV) in 14‐month‐old conscious mdx mice, which was reversed by atropine. This finding suggests that enhanced parasympathetic function is likely responsible for the improved HRV mediated by simvastatin. Together, these findings indicate that simvastatin markedly improves cardiac health and function in dystrophic mice, and therefore may provide a novel approach for treating cardiomyopathy in DMD.

The Vascular Consequences of Metabolic Syndrome: Rodent Models, Endothelial Dysfunction, and Current Therapies

Metabolic syndrome is characterized by visceral obesity, dyslipidemia, hyperglycemia and hypertension, and affects over one billion people. Independently, the components of metabolic syndrome each have the potential to affect the endothelium to cause vascular dysfunction and disrupt vascular homeostasis. Rodent models of metabolic syndrome have significantly advanced our understanding of this multifactorial condition. In this mini-review we compare the currently available rodent models of metabolic syndrome and consider their limitations. We also discuss the numerous mechanisms by which metabolic abnormalities cause endothelial dysfunction and highlight some common pathophysiologies including reduced nitric oxide production, increased reactive oxygen species and increased production of vasoconstrictors. Additionally, we explore some of the current therapeutics for the comorbidities of metabolic syndrome and consider how these benefit the vasculature.

Paeonol protects against hypertension in spontaneously hypertensive rats by restoring vascular endothelium

The present study focused on the effect of paeonol, one of the main components of Guizhi Fuling Pill, on blood pressure, cerebral blood flow, and vascular endothelium injury in spontaneously hypertensive rats to provide theoretical basis for the treatment of hypertension. After treatment with paeonol, the mean arterial pressure (MAP) of LSHRT and HSHRT rats decreased gradually with the prolongation of treatment time. The systolic blood flow velocity (Vs), diastolic blood flow velocity (Vd) and mean blood flow velocity (Vm) were significantly increased after paeonol treatment (p &lt; 0.05). Paeonol effectively improved the blood pressure and increased the cerebral blood flow velocity in spontaneously hypertensive rats. This may be related to the fact that paeonol reduced the blood viscosity and the oxidative stress and improved the antioxidant capacity. Moreover, paeonol protected vascular endothelial cells and reduced vascular endothelial injury in spontaneously hypertensive rats.

Redox State in Atrial Fibrillation Pathogenesis and Relevant Therapeutic Approaches

BACKGROUND

Myocardial redox state is a critical determinant of atrial biology, regulating cardiomyocyte apoptosis, ion channel function, and cardiac hypertrophy/fibrosis and function. Nevertheless, it remains unclear whether the targeting of atrial redox state is a rational therapeutic strategy for atrial fibrillation prevention.

OBJECTIVE

To review the role of atrial redox state and anti-oxidant therapies in atrial fibrillation.

METHOD

Published literature in Medline was searched for experimental and clinical evidence linking myocardial redox state with atrial fibrillation pathogenesis as well as studies looking into the role of redoxtargeting therapies in the prevention of atrial fibrillation.

RESULTS

Data from animal models have shown that altered myocardial nitroso-redox balance and NADPH oxidases activity are causally involved in the pathogenesis of atrial fibrillation. Similarly experimental animal data supports that increased reactive oxygen / nitrogen species formation in the atrial tissue is associated with altered electrophysiological properties of atrial myocytes and electrical remodeling, favoring atrial fibrillation development. In humans, randomized clinical studies using redox-related therapeutic approaches (e.g. statins or antioxidant agents) have not documented any benefits in the prevention of atrial fibrillation development (mainly post-operative atrial fibrillation risk).

CONCLUSION

Despite strong experimental and translational data supporting the role of atrial redox state in atrial fibrillation pathogenesis, such mechanistic evidence has not been translated to clinical benefits in atrial fibrillation risk in randomized clinical studies using redox-related therapies.

Atorvastatin inhibits pro-inflammatory actions of aldosterone in vascular smooth muscle cells by reducing oxidative stress

Vascular inflammatory responses play an important role in several cardiovascular diseases. Of the many pro-inflammatory vasoactive factors implicated in this process, is aldosterone, an important mediator of vascular oxidative stress. Statins, such as atorvastatin, are cholesterol-lowering drugs that have pleiotropic actions, including anti-oxidant properties independently of their cholesterol-lowering effect. This study investigated whether atorvastatin prevents aldosterone-induced VSMC inflammation by reducing reactive oxygen species (ROS) production. Vascular smooth muscle cells (VSMC) from WKY rats were treated with 1 μM atorvastatin for 60 min or for 72 h prior to aldosterone (10-7 mol/L) stimulation. Atorvastatin inhibited Rac1/2 and p47phox translocation from the cytosol to the membrane, as well as reduced aldosterone-induced ROS production. Atorvastatin also attenuated aldosterone-induced vascular inflammation and macrophage adhesion to VSMC. Similarly EHT1864, a Rac1/2 inhibitor, and tiron, ROS scavenger, reduced macrophage adhesion. Through its inhibitory effects on Rac1/2 activation and ROS production, atorvastatin reduces vascular ROS generation and inhibits VSMC inflammation. Our data suggest that in conditions associated with aldosterone-induced vascular damage, statins may have vasoprotective effects by inhibiting oxidative stress and inflammation.

[Comparative analysis of gene expression in vascular cells of patients with advanced atherosclerosis]

In this study we performed a comparative gene expression analysis of carotid arteries in the area of atherosclerotic plaques and healthy internal mammary arteries of patients with advanced atherosclerosis by using microarray HumanHT-12 BeadChip ("Illumina"). The most down-regulated genes were APOD, FABP4, CIDEC and FOSB, and up-regulated gene was SPP1 (|FC|>64; pFDR<0.05). The majority of differentially expressed genes were down-regulated in advanced atherosclerotic plaques. Unexpectedly, genes involved in immune and inflammatory responses were down-regulated in advanced atherosclerotic plaques to compare with the healthy arteries (arachidonic acid metabolism, cytokine-cytokine receptor interaction, NOD-like receptor signaling pathway, Jak-STAT signaling pathway, TNF signaling pathway). "Cellular response to metal ion" (metallothioneins) and "Extracellular matrix organization" were the most significant Gene ontology terms among the down- and up-regulated genes, respectively.

Statin therapy exacerbates alcohol-induced constriction of cerebral arteries via modulation of ethanol-induced BK channel inhibition in vascular smooth muscle

Statins constitute the most commonly prescribed drugs to decrease cholesterol (CLR). CLR is an important modulator of alcohol-induced cerebral artery constriction (AICAC). Using rats on a high CLR diet (2% CLR) we set to determine whether atorvastatin administration (10mg/kg daily for 18-23weeks) modified AICAC. Middle cerebral arteries were pressurized in vitro at 60mmHg and AICAC was evoked by 50mM ethanol, that is within the range of blood alcohol detected in humans following moderate-to-heavy drinking. AICAC was evident in high CLR+atorvastatin group but not in high CLR diet+placebo. Statin exacerbation of AICAC persisted in de-endothelialized arteries, and was blunted by CLR enrichment in vitro. Fluorescence imaging of filipin-stained arteries showed that atorvastatin decreased vascular smooth muscle (VSM) CLR when compared to placebo, this difference being reduced by CLR enrichment in vitro. Voltage- and calcium-gated potassium channels of large conductance (BK) are known VSM targets of ethanol, with their beta1 subunit being necessary for ethanol-induced channel inhibition and resulting AICAC. Ethanol-induced BK inhibition in excised membrane patches from freshly isolated myocytes was exacerbated in the high CLR diet+atorvastatin group when compared to high CLR diet+placebo. Unexpectedly, atorvastatin decreased the amount and function of BK beta1 subunit as documented by immunofluorescence imaging and functional patch-clamp studies. Atorvastatin exacerbation of ethanol-induced BK inhibition disappeared upon artery CLR enrichment in vitro. Our study demonstrates for the first time statin's ability to exacerbate the vascular effect of a widely consumed drug of abuse, this exacerbation being driven by statin modulation of ethanol-induced BK channel inhibition in the VSM via CLR-mediated mechanism.

Enabling Precision Cardiology Through Multiscale Biology and Systems Medicine

The traditional paradigm of cardiovascular disease research derives insight from large-scale, broadly inclusive clinical studies of well-characterized pathologies. These insights are then put into practice according to standardized clinical guidelines. However, stagnation in the development of new cardiovascular therapies and variability in therapeutic response implies that this paradigm is insufficient for reducing the cardiovascular disease burden. In this state-of-the-art review, we examine 3 interconnected ideas we put forth as key concepts for enabling a transition to precision cardiology: 1) precision characterization of cardiovascular disease with machine learning methods; 2) the application of network models of disease to embrace disease complexity; and 3) using insights from the previous 2 ideas to enable pharmacology and polypharmacology systems for more precise drug-to-patient matching and patient-disease stratification. We conclude by exploring the challenges of applying a precision approach to cardiology, which arise from a deficit of the required resources and infrastructure, and emerging evidence for the clinical effectiveness of this nascent approach.

Application of Metabolic Profiling to Abdominal Aortic Aneurysm Research

Abdominal aortic aneurysm (AAA) is a complex disease posing diagnostic and therapeutic challenges. Metabonomics may aid in the diagnosis of AAA, determination of individualized risk, discovery of therapeutic targets, and improve understanding of pathogenesis. A systematic review of the diversity and outcomes of existing AAA metabonomic research has been performed. Original research studies applying metabonomics to human aneurysmal disease are included. Seven relevant articles were identified: four studies were based on plasma/serum metabolite profiling, and three studies examined aneurysmal tissue. Aminomalonic acid, guanidinosuccinic acid, and glycerol emerge as potential plasma biomarkers of large aneurysm. Lipid profiling improves predictive models of aneurysm presence. Patterns of metabolite variation associated with AAA relate to carbohydrate and lipid metabolism. Perioperative perturbations in metabolites suggest differential systemic inflammatory responses to surgery, generating hypotheses for adjunctive perioperative therapy. Significant limitations include small study sizes, lack of correction for multiple testing false discovery rates, and single time-point sampling. Metabolic profiling carries the potential to identify biomarkers of AAA and elucidate pathways underlying aneurysmal disease. Statistically and methodologically robust studies are required for validation, addressing the hiatus in understanding mechanisms of aneurysm growth and developing effective treatment strategies.

Pleiotropic effects of statins in the perioperative setting

Statins belong to a specific group of drugs that have been described for their ability to control hyperlipidemia as well as for other pleiotropic effects such as improving vascular endothelial function, inhibition of oxidative stress pathways, and anti-inflammatory actions. Accumulating clinical evidence strongly suggests that statins also have a beneficial effect on perioperative morbidity and mortality. Therefore, this review aims to present all recent and pooled data on statin treatment in the perioperative setting as well as to highlight considerations regarding their indications and therapeutic application.

Perivascular adipose tissue as a regulator of vascular disease pathogenesis: identifying novel therapeutic targets

Adipose tissue (AT) is an active endocrine organ with the ability to dynamically secrete a wide range of adipocytokines. Importantly, its secretory profile is altered in various cardiovascular disease states. AT surrounding vessels, or perivascular AT (PVAT), is recognized in particular as an important local regulator of vascular function and dysfunction. Specifically, PVAT has the ability to sense vascular paracrine signals and respond by secreting a variety of vasoactive adipocytokines. Due to the crucial role of PVAT in regulating many aspects of vascular biology, it may constitute a novel therapeutic target for the prevention and treatment of vascular disease pathogenesis. Signalling pathways in PVAT, such as those using adiponectin, H₂ S, glucagon-like peptide 1 or pro-inflammatory cytokines, are among the potential novel pharmacological therapeutic targets of PVAT.

LINKED ARTICLES

This article is part of a themed section on Molecular Mechanisms Regulating Perivascular Adipose Tissue - Potential Pharmacological Targets? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.20/issuetoc.

Emerging drugs for the treatment of angina pectoris

INTRODUCTION

Angina pectoris, or symptomatic myocardial ischaemia, reflects an impairment of coronary blood flow, and usually a deficiency of available myocardial energetics. Treatment options vary with the precise cause, which may vary with regards to the roles of increased myocardial oxygen demand versus reduced supply. Traditionally, organic nitrates, β-adrenoceptor antagonists, and non-dihydropyridine calcium antagonists were the only commonly used prophylactic anti-anginal agents. However, many patients failed to respond adequately to such therapy, and/or were unsuitable for their use. Areas covered: A number of 'new' agents have been shown to represent ancillary forms of prophylactic anti-anginal therapy and are particularly useful in patients who are relatively unsuitable for either percutaneous or surgical revascularisation. These include modulators of myocardial metabolic efficiency, such as perhexiline, trimetazidine and ranolazine, as well as high dose allopurinol, nicorandil and ivabradine. The advantages and disadvantages of these various agents are summarized. Expert opinion: 'Optimal' medical treatment of angina pectoris now includes use of agents primarily intended to reduce risk of infarction (e.g. statins, aspirin, ACE inhibitors). In patients whose angina persists despite the use of 'standard' anti-anginal therapy, and who are not ideal for invasive revascularization options, a number of emerging drugs offer prospects of symptomatic relief.

Endothelial cell metabolism: A novel player in atherosclerosis? Basic principles and therapeutic opportunities

Atherosclerosis is a leading cause of morbidity and mortality in Western society. Despite improved insight into disease pathogenesis and therapeutic options, additional treatment strategies are required. Emerging evidence highlights the relevance of endothelial cell (EC) metabolism for angiogenesis, and indicates that EC metabolism is perturbed when ECs become dysfunctional to promote atherogenesis. In this review, we overview the latest insights on EC metabolism and discuss current knowledge on how atherosclerosis deregulates EC metabolism, and how maladaptation of deregulated EC metabolism can contribute to atherosclerosis progression. We will also highlight possible therapeutic avenues, based on targeting EC metabolism.

Simvastatin offers new prospects for the treatment of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is the most common and severe inherited neuromuscular disorder. DMD is caused by mutations in the gene encoding the dystrophin protein in muscle fibers. Dystrophin was originally proposed to be a structural protein that protected the sarcolemma from stresses produced during contractions. However, more recently, experimental evidence has revealed a far more complicated picture, with the loss of dystrophin causing dysfunction of multiple muscle signaling pathways, which all contribute to the overall disease pathophysiology. Current gene-based approaches for DMD are conceptually appealing since they offer the potential to restore dystrophin to muscles, albeit a partially functional, truncated form of the protein. However, given the cost and technical challenges facing these genetic approaches, it is important to consider if relatively inexpensive, clinically used drugs may be repurposed for treating DMD. Here, we discuss our recent findings showing the potential of simvastatin as a novel therapy for DMD.

Oxidative stress in the pathogenesis of atherothrombosis associated with anti-phospholipid syndrome and systemic lupus erythematosus: new therapeutic approaches

Atherothrombosis is a recurrent complication in APS and SLE patients. Oxidative stress has been suggested as a key player underlying this process. Autoantibodies have been pointed to as the main contributors to abnormality in the oxidative status observed in APS and SLE patients, promoting the increased production of oxidant species and the reduction of antioxidant molecules. This imbalance causes vascular damage through the activation of immune cells, including monocytes, lymphocytes and neutrophils, causing the expression of pro-inflammatory and procoagulant molecules, the formation of neutrophil extracellular traps and the adhesion of these cells to the endothelium; the induction of cellular apoptosis and impaired cell clearance, which in turn enhances autoantibody neogeneration; and cytotoxicity of endothelial cells. This review describes the mechanisms underlying the role of oxidative stress in the pathogenesis of atherothrombosis associated with APS and SLE, focused on the effect of autoantibodies, the different cell types involved and the diverse effectors, including cytokines, procoagulant proteins and their main modulators, such as oxidant/antioxidant species and intracellular pathways in each pathology. We further discuss new therapies aimed at restoring the oxidative stress balance and subsequently to tackle atherothrombosis in APS and SLE.

Statins and oxidative stress in chronic heart failure

Statins are the most commonly prescribed drugs for the treatment of dyslipidemia. They are also recommended in primary and secondary prevention of cardiovascular disease. In addition to decreasing cholesterol synthesis, statins interfere with the synthesis of isoprenoid intermediates, which may explain many of their pleiotropic properties, including their antioxidant effects. Oxidative stress is defined as an imbalance between the synthesis of reactive oxygen species and their elimination by antioxidant defense systems, with a prevailing pro-oxidant status that results in macromolecular damage and disruption of cellular redox signaling. Reactive oxygen species interfere with various processes that affect cardiac structure and function, contributing to the contractile dysfunction, myocardial hypertrophy and fibrosis observed in the pathophysiology of heart failure. By regulating several molecular pathways that control nicotinamide adenine dinucleotide phosphate oxidase and endothelial nitric oxide synthase activity, statins help restore redox homeostasis. These drugs also contribute to the control of inflammation and appear to have a protective role in various diseases. The results of observational studies and clinical trials with statins in heart failure have not been consensual. This review aims to analyze the role of oxidative stress in heart failure and the molecular mechanisms underlying statins' antioxidant properties. It also examines current scientific evidence on the use of these drugs as a specific treatment for heart failure.

The Restorative Effects of Eucommia ulmoides Oliver Leaf Extract on Vascular Function in Spontaneously Hypertensive Rats

Eucommia ulmoides Oliv. leaf is a traditional Chinese antihypertensive and antidiabetic medicine. We examined the effects of chronic Eucommia leaf extract (ELE) administration on artery function and morphology in spontaneously hypertensive rats (SHRs). ELE was orally administered via normal diet ad libitum to six-week-old male SHRs at a concentration of 5% for seven weeks. Acetylcholine (ACh)-induced endothelium-dependent relaxation, sodium nitroprusside (SNP)-induced endothelium-independent relaxation, plasma nitric oxide (NO) levels, and media thickness were assessed. ELE significantly improved ACh-induced aortic endothelium-dependent relaxation but did not affect SNP-induced endothelium-independent relaxation in the SHRs, as compared to the animals receiving normal diet. Plasma NO levels and media thickness were significantly increased and decreased, respectively, in the ELE-treated SHRs. Therefore, long-term ELE administration may effectively improve vascular function by increasing plasma NO levels and bioavailability, and by preventing vascular hypertrophy in the SHR aorta.

A new therapeutic effect of simvastatin revealed by functional improvement in muscular dystrophy

Duchenne muscular dystrophy (DMD) is a lethal, degenerative muscle disease with no effective treatment. DMD muscle pathogenesis is characterized by chronic inflammation, oxidative stress, and fibrosis. Statins, cholesterol-lowering drugs, inhibit these deleterious processes in ischemic diseases affecting skeletal muscle, and therefore have potential to improve DMD. However, statins have not been considered for DMD, or other muscular dystrophies, principally because skeletal-muscle-related symptoms are rare, but widely publicized, side effects of these drugs. Here we show positive effects of statins in dystrophic skeletal muscle. Simvastatin dramatically reduced damage and enhanced muscle function in dystrophic (mdx) mice. Long-term simvastatin treatment vastly improved overall muscle health in mdx mice, reducing plasma creatine kinase activity, an established measure of muscle damage, to near-normal levels. This reduction was accompanied by reduced inflammation, more oxidative muscle fibers, and improved strength of the weak diaphragm muscle. Shorter-term treatment protected against muscle fatigue and increased mdx hindlimb muscle force by 40%, a value comparable to current dystrophin gene-based therapies. Increased force correlated with reduced NADPH Oxidase 2 protein expression, the major source of oxidative stress in dystrophic muscle. Finally, in old mdx mice with severe muscle degeneration, simvastatin enhanced diaphragm force and halved fibrosis, a major cause of functional decline in DMD. These improvements were accompanied by autophagy activation, a recent therapeutic target for DMD, and less oxidative stress. Together, our findings highlight that simvastatin substantially improves the overall health and function of dystrophic skeletal muscles and may provide an unexpected, novel therapy for DMD and related neuromuscular diseases.

Statins as Pleiotropic Modifiers of Vascular Oxidative Stress and Inflammation

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in the industrialized world and in the future is expected to be the number one killer worldwide. The main cause underlying CVD is atherosclerosis. A key event in atherosclerosis initiation and progression is oxidative stress through the production of reactive oxygen species as well as endothelial dysfunction. Several pro- inflammatory and anti-inflammatory cytokines and proteins are involved in this process, complemented by activation of adhesion molecules that promote leukocyte rolling, tethering and infiltration into the sub-endothelial space. Statins represent the agent of choice since numerous clinical trials have verified that their pharmacological action extends beyond lipid lowering. Statins demonstrate direct anti-oxidant effects by scavenging free radicals and stimulating anti-oxidant enzymes while acting as regulators for cytokine, protein and adhesion molecule expression, all of which are involved in the atherosclerotic process. Statin use is considered one of the most efficient currently used interventions in managing CVD with the likely hood of remaining so in the near future.

Vascular injury in diabetic db/db mice is ameliorated by atorvastatin: role of Rac1/2-sensitive Nox-dependent pathways

Oxidative stress [increased bioavailability of reactive oxygen species (ROS)] plays a role in the endothelial dysfunction and vascular inflammation, which underlie vascular damage in diabetes. Statins are cholesterol-lowering drugs that are vasoprotective in diabetes through unknown mechanisms. We tested the hypothesis that atorvastatin decreases NADPH oxidase (Nox)-derived ROS generation and associated vascular injury in diabetes. Lepr(db)/Lepr(db) (db/db) mice, a model of Type 2 diabetes and control Lepr(db)/Lepr(+) (db/+) mice were administered atorvastatin (10 mg/kg per day, 2 weeks). Atorvastatin improved glucose tolerance in db/db mice. Systemic and vascular oxidative stress in db/db mice, characterized by increased plasma TBARS (thiobarbituric acid-reactive substances) levels and exaggerated vascular Nox-derived ROS generation respectively, were inhibited by atorvastatin. Cytosol-to-membrane translocation of the Nox regulatory subunit p47(phox) and the small GTPase Rac1/2 was increased in vessels from db/db mice compared with db/+ mice, an effect blunted by atorvastatin. The increase in vascular Nox1/2/4 expression and increased phosphorylation of redox-sensitive mitogen-activated protein kinases (MAPKs) was abrogated by atorvastatin in db/db mice. Pro-inflammatory signalling (decreased IκB-α and increased NF-κB p50 expression, increased NF-κB p65 phosphorylation) and associated vascular inflammation [vascular cell adhesion molecule-1 (VCAM-1) expression and vascular monocyte adhesion], which were increased in aortas of db/db mice, were blunted by atorvastatin. Impaired acetylcholine (Ach)- and insulin (INS)-induced vasorelaxation in db/db mice was normalized by atorvastatin. Our results demonstrate that, in diabetic mice, atorvastatin decreases vascular oxidative stress and inflammation and ameliorates vascular injury through processes involving decreased activation of Rac1/2 and Nox. These findings elucidate redox-sensitive and Rac1/2-dependent mechanisms whereby statins protect against vascular injury in diabetes.

Phase II anti-inflammatory and immune-modulating drugs for acute ischaemic stroke

INTRODUCTION

Stroke is the second leading cause of death worldwide and the leading cause of adult neurological disability. Despite advances in stroke unit care, and increasing use of thrombolysis, there remains an urgent need for safe and effective treatments for acute ischaemic stroke. However, this is against a backdrop of multiple failures in translational drug development. Cerebral ischaemia initiates a complex cascade of immune and inflammatory pathways in the brain microvasculature and periphery, which contribute to the evolution of cerebral injury, resolution and repair. Targeting specific inflammatory or immune pathways, therefore, represents an attractive treatment strategy in acute ischaemic stroke. Although anti-inflammatory drugs have already failed in clinical trial development, several are currently at the Phase II developmental stage.

AREAS COVERED

The authors highlight several candidate drugs, which modulate a range of inflammatory and immune pathways, and have been investigated in pre-clinical and Phase II studies to date.

EXPERT OPINION

Drugs targeting inflammatory and immune pathways offer theoretical advantages including potentially longer therapeutic time windows and effects complementary to thrombolysis (ameliorating reperfusion injury). Fundamental changes in the approach to pre-clinical and clinical drug development are required to facilitate successful translation of promising candidate drugs into clinical practice.

Hypertensive vascular remodeling was inhibited by Xuezhikang through the regulation of Fibulin-3 and MMPs in spontaneously hypertensive rats

Fibulin-3, an extracellular glycoprotein, has been suggested as having functions in vessels. In hypertension, extracellular matrix, matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) play important roles in cardiovascular remodeling. However, the role of Fibulin-3 as an extracellular glycoprotein in hypertensive vascular remodeling remains unclear. Our study was to determine whether Fibulin-3 and TIMPs/MMPs would affect vascular structure during hypertension and the treatment of Xuezhikang. Thirty spontaneously hypertensive rats (SHRs) aged 8 weeks were randomized to three groups: SHRs control group (SHRs group, n=10), group treated with low dose Xuezhikang (XZK-L, 20 mg/kg/d, n=10) and group treated with high dose Xuezhikang (XZK-H, 200 mg/kg/d, n=10), the normal group was comprised of ten Wistar-Kyoto (WKY) rats of the same age. We showed that serum nitric oxide (NO) in control group was significantly lower than WKY group (P<0.05). Concomitantly, serum oxidized low-density lipoprotein (ox-LDL) was higher than WKY group (P<0.05). The treatment of high dose Xuezhikang significantly dicreased ox-LDL, left ventricular mass index (LVMI) and Wall-to-lumen area ratio (W/L) of thoracic aorta (P<0.05), while serum NO was significantly increasing (P<0.05). Moreover, the expressions of Fibulin-3 and MMP-2, 9 at both protein and mRNA levels were significantly higher in thoracic aorta of SHRs group compared to WKY group by immunohistochemistry and western blotting (P<0.05). However, the levels of Fibulin-3 and MMP-2, 9 were significantly decreased in XZK-H group compared to control group (P<0.05). The level of TIMP-3 had no significance difference between SHRs and WKY groups (P>0.05). So the levels of Fibulin-3 and MMP-2, 9 in SHRs could be inhibited by Xuezhikang. Furthermore, a strong correlation in transcript expression was established between Fibulin-3, and MMP-2 (r=0.81, P<0.05) and MMP-9 (r=0.92, P<0.05) through immunohistochemistry. In summary, the overexpression of Fibulin-3 and MMP-2, 9 levels were associated with hypertension and vascular remodeling and inhibited by Xuezhikang. Fibulin-3 is a candidate in the pathogenesis of cardiovascular remodeling in hypertension.

Chlamydia pneumoniae and oxidative stress in cardiovascular disease: state of the art and prevention strategies

Chlamydia pneumoniae, a pathogenic bacteria responsible for respiratory tract infections, is known as the most implicated infectious agent in atherosclerotic cardiovascular diseases (CVDs). Accumulating evidence suggests that C. pneumoniae-induced oxidative stress may play a critical role in the pathogenesis of CVDs. Indeed, the overproduction of reactive oxygen species (ROS) within macrophages, endothelial cells, platelets and vascular smooth muscle cells (VSMCs) after C. pneumoniae exposure, has been shown to cause low density lipoprotein oxidation, foam cell formation, endothelial dysfunction, platelet adhesion and aggregation, and VSMC proliferation and migration, all responsible for the typical pathological changes of atherosclerotic plaque. The aim of this review is to improve our insight into C. pneumoniae-induced oxidative stress in order to suggest potential strategies for CVD prevention. Several antioxidants, acting on multi-enzymatic targets related to ROS production induced by C. pneumoniae, have been discussed. A future strategy for the prevention of C. pneumoniae-associated CVDs will be to target chlamydial HSP60, involved in oxidative stress.

Markers of subclinical atherosclerosis in premenopausal women with vitamin D deficiency and effect of vitamin D replacement

BACKGROUND

Recent studies have revealed a relationship between vitamin D deficiency and atherosclerosis. This study aims to investigate the impact of vitamin D deficiency and replacement on markers of subclinical atherosclerosis in young premenopausal women in whom vitamin D deficiency is prevalent.

METHODS

Thirty-one premenopausal vitamin D deficient women and 27 age and gender-matched control subjects were enrolled in this study. Markers of subclinical atherosclerosis including carotid intima-media thickness (cIMT), flow-mediated dilatation (FMD), endothelial progenitor cell (EPC) count and cytokine levels were determined at baseline. All measurements were repeated at 6-month follow-up in vitamin D-deficient subjects after vitamin D replacement.

RESULTS

Vitamin D deficient premenopausal women had lower FMD (9.9 ± 1.3 vs. 13.8 ± 1.7%, p < 0.001) and EPC counts at baseline. This population also had lower IL-10 and higher IL-17 levels. A 6-month vitamin D replacement therapy resulted in a significant increase in FMD (9.9 ± 1.3 vs. 11.4 ± 1.4%, p < 0.001) and EPC counts. Furthermore, cytokine profile shifted toward a more anti-inflammatory phenotype including elevated IL-10 and decreased IL-17 levels. cIMT was not different between patient and control groups and did not change following vitamin D replacement. Change in 25(OH)D and IL-17 levels were independent predictors of the change in FMD measurements following vitamin D replacement.

CONCLUSION

This study demonstrates that endothelial function is impaired in otherwise healthy vitamin D deficient young premenopausal women and improves with 6-month replacement therapy. Immune-modulatory effects of vitamin D may, at least partly, be responsible for its beneficial effects on vascular health.

Rac1 and cholesterol metabolism in macrophage

In the early stages of atherosclerotic lesion development, cholesterol is mostly present as esterified cholesterol stored in macrophage cytoplasmic lipid droplets. However, when the lesion evolves, free cholesterol accumulates in other compartments, such as lysosomes and plasma membrane. A number of studies support a role for intracellular cholesterol content and distribution in regulating several cell functions. Particularly, membrane free cholesterol content has a specific effect on signaling pathways involved in regulating cell motility and organization of the actin cytoskeleton. These processes are regulated by several signaling pathways including the small GTPase Rac1. Rac1 belongs to the Rho GTPases of the Ras protein superfamily involved in the regulation of multiple cell functions, including cell proliferation, chemotaxis, phagocytosis, degranulation, and superoxide production. In this review, we discuss the role of Rac1 in macrophage with respect to cholesterol metabolism and trafficking as critical aspects for the development of atherosclerotic plaque.

Human tissue-type plasminogen activator

Tissue-type plasminogen activator (t-PA ) plays an important role in the removal of intravascular fibrin deposits and has several physiological roles and pathological activities in the brain. Its production by many other cell types suggests that t-PA has additional functions outside the vascular and central nervous system. Activity of t-PA is regulated at the level of its gene transcription, its mRNA stability and translation, its storage and regulated release, its interaction with cofactors that enhance its activity, its inhibition by inhibitors such as plasminogen activator inhibitor type 1 or neuroserpin, and its removal by clearance receptors. Gene transcription of t-PA is modulated by a large number of hormones, growth factors, cytokines or drugs and t-PA gene responses may be tissue-specific. The aim of this review is to summarise current knowledge on t-PA function and regulation of its pericellular activity, with an emphasis on regulation of its gene expression.

Atherosclerosis and cardiovascular disease in systemic lupus erythematosus: effects of in vivo statin treatment

OBJECTIVE

Statins may have beneficial vascular effects in systemic lupus erythematosus (SLE) beyond their cholesterol-lowering action, although the mechanisms involved are not completely understood. We investigated potential mechanisms involved in the efficacy of fluvastatin in preventing atherothrombosis in SLE.

METHODS

Eighty-five patients with SLE and 62 healthy donors were included in the study. Selected patients (n=27) received 20 mg/day fluvastatin for 1 month. Blood samples were obtained before the start and at the end of treatment. Monocytes from five patients were treated in vitro with fluvastatin.

RESULTS

Increased prothrombotic and inflammatory variables were found in patients with SLE. SLE monocytes displayed altered mitochondrial membrane potential and increased oxidative stress. Correlation and association analyses demonstrated a complex interplay among autoimmunity, oxidative stress, inflammation and increased risk of atherothrombosis in SLE. Fluvastatin treatment of patients for 1 month reduced the SLE Disease Activity Index and lipid levels, oxidative status and vascular inflammation. Array studies on monocytes demonstrated differential expression in 799 genes after fluvastatin treatment. Novel target genes and pathways modulated by fluvastatin were uncovered, including gene networks involved in cholesterol and lipid metabolism, inflammation, oxidative stress and mitochondrial activity. Electron microscopy analysis showed increased density volume of mitochondria in monocytes from fluvastatin-treated patients, who also displayed higher expression of genes involved in mitochondrial biogenesis. In vitro treatment of SLE monocytes confirmed the results obtained in the in vivo study.

CONCLUSIONS

Our overall data suggest that fluvastatin improves the impairment of a redox-sensitive pathway involved in processes that collectively orchestrate the pathophysiology of atherothrombosis in SLE.

Statins as regulators of redox state in the vascular endothelium: beyond lipid lowering

SIGNIFICANCE

Endothelial dysfunction and the imbalance between nitric oxide (NO) and reactive oxygen species production in the vascular endothelium are important early steps in atherogenesis, a major socioeconomic health problem. Statins have well-established roles in primary and secondary prevention of cardiovascular disease (CVD), due to both their lipid-lowering capacity and their pleiotropic properties. It is therefore important to understand the mechanisms by which statins can modify endothelial function and affect atherogenesis.

RECENT ADVANCES

In the last decade, the concept of statin pleiotropy has been reinforced by a large number of cell culture, animal, and translational studies. Statins have been shown to suppress the activity of pro-oxidant enzymes (such as NADPH oxidase) and pro-inflammatory transcriptional pathways in the endothelium. At the same time, they enhance endothelial NO synthase expression and activity while they also improve its enzymatic coupling. This leads to increased NO bioavailability and improved endothelial function.

CRITICAL ISSUES

Despite significant recent advances, the exact mechanisms of statin pleitropy are still only partially understood. The vast majority of the published literature relies on animal studies, while the actual mechanistic studies in humans are limited.

FUTURE DIRECTIONS

The success of statins as endothelium redox-modifying agents with a direct impact on clinical outcome highlights the importance of the endothelium as a therapeutic target in CVD. Better understanding of the mechanisms that underlie endothelial dysfunction could lead to the design of novel therapeutic strategies that target the vascular endothelium for the prevention and treatment of CVD.

Rac1-mediated effects of HMG-CoA reductase inhibitors (statins) in cardiovascular disease

SIGNIFICANCE

HMG-CoA reductase inhibitors (statins) lower serum cholesterol concentrations and are beneficial in the primary and secondary prevention of coronary heart disease. The positive clinical effects have only partially been reproduced with other lipid-lowering interventions suggesting potential statin effects in addition to cholesterol lowering. In experimental models, direct beneficial cardiovascular effects that are mediated by the inhibition of isoprenoids have been documented, which serve as lipid attachments for intracellular signaling molecules such as small Rho guanosine triphosphate-binding proteins, whose membrane localization and function are dependent on isoprenylation.

RECENT ADVANCES

Rac1 GTPase is an established master regulator of cell motility through the cortical actin reorganization and of reactive oxygen species generation through the regulation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity.

CRITICAL ISSUES

Observations in cells, animals, and humans have implicated the activation of Rac1 GTPase as a key component of cardiovascular pathologies, including the endothelial dysfunction, cardiac hypertrophy and fibrosis, atrial fibrillation, stroke, hypertension, and chronic kidney disease. However, the underlying signal transduction remains incompletely understood.

FUTURE DIRECTIONS

Based on the recent advance made in Rac1 research in the cardiovascular system by using mouse models with transgenic overexpression of activated Rac1 or conditional knockout, as well as Rac1-specific small molecule inhibitor NSC 23766, the improved understanding of the Rac1-mediated effects statins may help to identify novel therapeutic targets and strategies.

Targeting the mevalonate cascade as a new therapeutic approach in heart disease, cancer and pulmonary disease

The cholesterol biosynthesis pathway, also known as the mevalonate (MVA) pathway, is an essential cellular pathway that is involved in diverse cell functions. The enzyme 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase (HMGCR) is the rate-limiting step in cholesterol biosynthesis and catalyzes the conversion of HMG-CoA to MVA. Given its role in cholesterol and isoprenoid biosynthesis, the regulation of HMGCR has been intensely investigated. Because all cells require a steady supply of MVA, both the sterol (i.e. cholesterol) and non-sterol (i.e. isoprenoid) products of MVA metabolism exert coordinated feedback regulation on HMGCR through different mechanisms. The proper functioning of HMGCR as the proximal enzyme in the MVA pathway is essential under both normal physiologic conditions and in many diseases given its role in cell cycle pathways and cell proliferation, cholesterol biosynthesis and metabolism, cell cytoskeletal dynamics and stability, cell membrane structure and fluidity, mitochondrial function, proliferation, and cell fate. The blockbuster statin drugs ('statins') directly bind to and inhibit HMGCR, and their use for the past thirty years has revolutionized the treatment of hypercholesterolemia and cardiovascular diseases, in particular coronary heart disease. Initially thought to exert their effects through cholesterol reduction, recent evidence indicates that statins also have pleiotropic immunomodulatory properties independent of cholesterol lowering. In this review we will focus on the therapeutic applications and mechanisms involved in the MVA cascade including Rho GTPase and Rho kinase (ROCK) signaling, statin inhibition of HMGCR, geranylgeranyltransferase (GGTase) inhibition, and farnesyltransferase (FTase) inhibition in cardiovascular disease, pulmonary diseases (e.g. asthma and chronic obstructive pulmonary disease (COPD)), and cancer.

Dysfunction of vascular smooth muscle and vascular remodeling by simvastatin

Statins, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, are widely prescribed for hypercholesterolemia. With the increasing use of statins, numerous reports demonstrated that statins can cause damage to skeletal muscles. However, the toxicities of statins on vascular smooth muscle, which are essential to cardiovascular homeostasis, have not been previously described. Here, we examined the effects of simvastatin on the contractile function and the integrity of vascular smooth muscle in isolated rat thoracic aortic rings, primary cultured vascular smooth muscle cells (VSMCs) in vitro and rats in vivo. In aortic rings, simvastatin suppressed the normal agonist-induced contractile responses in time- and concentration-dependent manners (0.86 g ± 0.11 at 10 μM simvastatin for 24 h compared with 1.89 g ± 0.11 at control). The suppression persisted in the endothelium-denuded aortic rings and was irreversible even after wash-out of simvastatin. Simvastatin suppressed the contraction induced by Bay K8644, an activator of voltage-operated Ca²⁺ channel (VOCC) in rat aortic rings and abolished agonist-induced intracellular Ca²⁺ increase in VSMCs. The simvastatin-induced contractile dysfunction was reversed by the supplementation of mevalonate and geranylgeranylpyrophosphate, precursors for protein isoprenylation. Consistently, activation of RhoA, a representative isoprenylated protein, was disrupted by simvastatin in VSMCs and RhoA-mediated phosphorylation of MYPT1 and CPI-17, and tonic tension were also suppressed. Notably, prolonged treatment of simvastatin up to 48 h induced apoptosis of vascular smooth muscle in aortic rings. Most importantly, simvastatin treatment in vivo significantly attenuated the agonist-induced vasoconstriction in rats ex vivo and induced a decrease in luminal area of the vascular wall. Collectively, these results demonstrate that simvastatin can impair the normal vascular contractility by disturbing Ca²⁺ influx and RhoA activity, ultimately leading to apoptosis and structural remodeling.

Advanced glycation end-products: a common pathway in diabetes and age-related erectile dysfunction

Reactive derivatives of non-enzymatic glucose-protein condensation reactions integrate a heterogeneous group of irreversible adducts called advanced glycation end-products (AGEs). Numerous studies have investigated the role of the AGEs in cardiovascular system; however, its contribution to erectile dysfunction (ED) that is an early manifestation of cardiovascular disease has been less intensively investigated. This review summarizes the most recent advances concerning AGEs effects in the cavernous tissue of the penis and in ED onset, particularly on diabetes and aging, conditions that not only favor AGEs formation, but also increase risk of developing ED. The specific contribution of AGE on intra- and extracellular deposition of insoluble complexes, interference in activity of endothelial nitric oxide (NO) synthase, NO bioavailability, endothelial-dependent vasodilatation, as well as molecular pathways activated by receptor of AGEs are presented. Finally, the interventional actions that prevent AGEs formation, accumulation or activity in the cavernous tissue and that include nutritional pattern modulation, nutraceuticals, exercise, therapeutic strategies (statins, anti-diabetics, inhibitors of phosphodiesterase-5, anti-hypertensive drugs) and inhibitors of AGEs formation and crosslink breakers, are discussed. From this review, we conclude that despite the experiments conducted in animal models pointing to the AGE/RAGE axis as a potential interventional target with respect to ED associated with diabetes and aging, the clinical data have been very disappointing and, until now, did not provide evidence of benefits of treatments directed to AGE inactivation.

Does drug therapy reverse endothelial progenitor cell dysfunction in diabetes?

Endothelial progenitor cells (EPCs) are vital for the maintenance and repair of the endothelium. Decreased EPC number and function have been associated with increased cardiovascular (CVD) risk. Patients with diabetes have decreased number of circulating EPCs and decreased EPC function. This may account for some of the increased CVD risk seen in patients with diabetes that is not explained by traditional risk factors such as glycemic control, dyslipidemia and hypertension. Recent studies seem to indicate that drugs commonly used in diabetes patients such as metformin, thiazolidinediones, GLP-1 agonists, DPP-4 inhibitors, insulin, statins and ACE inhibitors may increase EPC number and improve EPC function. The mechanisms by which these drugs modulate EPC function may involve reduction in inflammation, oxidative stress and insulin resistance as well as an increase in nitric oxide (NO) bioavailability. This review will discuss the evidence in the literature regarding the above mentioned topics.