Direct vascular and cardioprotective effects of rosuvastatin, a new HMG-CoA reductase inhibitor

Comparative Analysis of High-Intensity versus Low-to-Moderate Intensity Statin Therapy in Patients Undergoing Rotational Atherectomy for Calcified Coronary Artery Disease

(1) Background: Moderate-intensity statin therapy, when compared to high-intensity statin therapy in Asian populations, has shown no significant difference in cardiovascular prognosis in small studies. The aim of this study was to compare the prognosis of patients based on statin intensity following rotational atherectomy (RA) during high-complexity percutaneous coronary intervention (PCI). (2) Methods: The ROCK registry, a multicenter retrospective study, included patients who had undergone rotational atherectomy (RA) during percutaneous coronary intervention (PCI) at nine tertiary medical centers in South Korea between January 2010 and October 2019. The patients were divided into high-intensity statin (H-statin) and moderate/low-intensity statin (M/L-statin) therapy groups. The primary endpoint includes outcomes (cardiac death, target vessel myocardial infarction (MI), and target vessel revascularization (TVR)) within an 18-month follow-up period. (3) Results: In this registry, a total of 540 patients with 583 lesions were included. We excluded 39 lesions from the analysis due to the absence of statin usage. The H-statin group had 394 lesions and the M/L-statin group had 150 lesions. There were no significant differences in baseline characteristics, procedural adverse events without heart failure history, triglycerides, or medications between the two groups. The procedural success rate showed a significant difference between the two groups. Multivariate analysis did not show a significant association between M/L-statin therapy and an increased risk of the primary endpoint. In propensity score matching analysis, no significant difference was observed in the primary endpoint either. (4) Conclusions: In high-complex RA PCI, moderate/low-intensity statin therapy is not inferior to high-intensity statin therapy in Korea.

Nitric Oxide in Cardiac Surgery: A Review Article

Perioperative organ injury remains a medical, social and economic problem in cardiac surgery. Patients with postoperative organ dysfunction have increases in morbidity, length of stay, long-term mortality, treatment costs and rehabilitation time. Currently, there are no pharmaceutical technologies or non-pharmacological interventions that can mitigate the continuum of multiple organ dysfunction and improve the outcomes of cardiac surgery. It is essential to identify agents that trigger or mediate an organ-protective phenotype during cardiac surgery. The authors highlight nitric oxide (NO) ability to act as an agent for perioperative protection of organs and tissues, especially in the heart-kidney axis. NO has been delivered in clinical practice at an acceptable cost, and the side effects of its use are known, predictable, reversible and relatively rare. This review presents basic data, physiological research and literature on the clinical application of NO in cardiac surgery. Results support the use of NO as a safe and promising approach in perioperative patient management. Further clinical research is required to define the role of NO as an adjunct therapy that can improve outcomes in cardiac surgery. Clinicians also have to identify cohorts of responders for perioperative NO therapy and the optimal modes for this technology.

Dual-modal molecular imaging and therapeutic evaluation of coronary microvascular dysfunction using indocyanine green-doped targeted microbubbles

Coronary microvascular dysfunction (CMD), which causes a series of cardiovascular diseases, seriously endangers human health. However, precision diagnosis of CMD is still challenging due to the lack of sensitive probes and complementary imaging technologies. Herein, we demonstrate indocyanine green-doped targeted microbubbles (named T-MBs-ICG) as dual-modal probes for highly sensitive near-infrared (NIR) fluorescence imaging and high-resolution ultrasound imaging of CMD in mouse models. In vitro results show that T-MBs-ICG can specifically target fibrin, a specific CMD biomarker, via the cysteine-arginine-glutamate-lysine-alanine (CREKA) peptide modified on the surface of microbubbles. We further employ T-MBs-ICG to achieve NIR fluorescence imaging of injured myocardial tissue in a CMD mouse model, leading to a signal-to-background ratio (SBR) of up to 50, which is 20 fold higher than that of the non-targeted group. Furthermore, ultrasound molecular imaging of T-MBs-ICG is obtained within 60 s after intravenous injection, providing molecular information on ventricular and myocardial structures and fibrin with a resolution of 1.033 mm × 0.466 mm. More importantly, we utilize comprehensive dual-modal imaging of T-MBs-ICG to evaluate the therapeutic efficacy of rosuvastatin, a cardiovascular drug for the clinical treatment of CMD. Overall, the developed T-MBs-ICG probes with good biocompatibility exhibit great potential in the clinical diagnosis of CMD.

Rosuvastatin Reverses Hypertension-Induced Changes in the Aorta Structure and Endothelium-Dependent Relaxation in Rats Through Suppression of Apoptosis and Inflammation

Vascular remodeling is one of the most critical complications caused by hypertension. Previous studies have demonstrated that rosuvastatin has anti-inflammatory, antioxidant, and antiplatelet effects and therefore can be used to treat cardiovascular disease. In this study, we explored the beneficial effects of rosuvastatin in reversing aortic remodeling in spontaneously hypertensive rats. After treating with different doses of rosuvastatin, its antilipid, antiapoptosis, and anti-inflammatory effects were determined. We also examined whether rosuvastatin can improve the structure and function of the aorta. We found that rosuvastatin treatment of spontaneously hypertensive rats for 2 months at 2 different doses can effectively reduce the media thickness of the aorta compared with the control group. Similarly, rosuvastatin improved the vascular relaxation function of the aortic rings at a high level of acetylcholine in vitro. Mechanistically, it was found that rosuvastatin increased the expression of endothelial nitric oxide synthase and plasma nitrite/nitrate levels. Besides, rosuvastatin suppressed the apoptosis and inflammation and upregulated the expression of gap-junction complex connexin 43 both in media and endothelium. Finally, rosuvastatin inhibited the AT₁R/PKCα/HSP70 signaling transduction pathway. In summary, these findings demonstrated that rosuvastatin could improve the vascular structure and function mainly by increasing endothelial nitric oxide synthase expression and preventing apoptosis and inflammation. This study provided evidence that rosuvastatin has beneficial effects in reversing the remodeling of the aorta due to hypertension.

Single Bolus Rosuvastatin Accelerates Calcium Uptake and Attenuates Conduction Inhomogeneity in Failing Rabbit Hearts With Regional Ischemia-Reperfusion Injury

Acute statin therapy reduces myocardial ischemia/reperfusion (IR) injury-induced ventricular fibrillation (VF), but the underlying electrophysiological mechanisms remain unclear. This study sought to investigate the antiarrhythmic effects of a single bolus rosuvastatin injection in failing rabbit hearts with IR injury and to unveil the underlying molecular mechanisms. Rabbits were divided into rosuvastatin, rosuvastatin + L-NAME, control, and L-NAME groups. Intravenous bolus rosuvastatin (0.5 mg/kg) and/or L-NAME (10 mg/kg) injections were administered 1 hour and 15 minutes before surgery, respectively. Heart failure was induced using rapid ventricular pacing. Under general anesthesia with isoflurane, an IR model was created by coronary artery ligation for 30 minutes, followed by reperfusion for 15 minutes. Plasma NO end product levels were measured during IR. Then, hearts were excised and Langendorff-perfused for optical mapping studies. Cardiac tissues were sampled for Western blot analysis. Rosuvastatin increased plasma NO levels during IR, which was abrogated by L-NAME. Spontaneous VF during IR was suppressed by rosuvastatin (P < 0.001). Intracellular calcium (Cai) decay and conduction velocity were significantly slower in the IR zone. Rosuvastatin accelerated Cai decay, ameliorated conduction inhomogeneity, and reduced the inducibility of spatially discordant alternans and VF significantly. Western blots revealed significantly higher expression of enhancing endothelial NO-synthase and phosphorylated enhancing endothelial NO-synthase proteins in the Rosuvastatin group. Furthermore, SERCA2a, phosphorylated connexin43, and phosphorylated phospholamban were downregulated in the IR zone, which was attenuated or reversed by rosuvastatin. Acute rosuvastatin therapy before ischemia reduced IR-induced VF by improving SERCA2a function and ameliorating conduction disturbance in the IR zone.

Asymmetric (ADMA) and Symmetric (SDMA) Dimethylarginines in Chronic Kidney Disease: A Clinical Approach

Asymmetric dimethylarginine (ADMA) and its enantiomer, Symmetric dimethylarginine (SDMA), are naturally occurring amino acids that were first isolated and characterized in human urine in 1970. ADMA is the most potent endogenous inhibitor of nitric oxide synthase (NOS), with higher levels in patients with end-stage renal disease (ESRD). ADMA has shown to be a significant predictor of cardiovascular outcome and mortality among dialysis patients. On the other hand, although initially SDMA was thought to be an innocuous molecule, we now know that it is an outstanding marker of renal function both in human and in animal models, with ESRD patients on dialysis showing the highest SDMA levels. Today, we know that ADMA and SDMA are not only uremic toxins but also independent risk markers for mortality and cardiovascular disease (CVD). In this review, we summarize the role of both ADMA and SDMA in chronic kidney disease along with other cardiovascular risk factors.

Rosuvastatin protects against oxidized low‑density lipoprotein‑induced endothelial cell injury of atherosclerosis in vitro

Atherosclerosis‑induced cardiovascular diseases (CVDs) are accompanied by substantial morbidity and mortality. The loss and injury of endothelial cells is the primary cause of atherosclerosis. Rosuvastatin is an alternative agent used to reduce the risk of cardiovascular disease. Subsequently, the present study aimed to investigate the protective effects of rosuvastatin on oxidized‑low‑density lipoprotein (ox‑LDL)‑induced human umbilical vein endothelial cell (HUVEC) injury. The viability of ox‑LDL‑cultured HUVECs with or without rosuvastatin (0.01, 0.1 and 1 µmol/l) pretreatment, and pretreatment at different time points (3, 6, 12 and 24 h) was determined using an MTT assay. Morphological changes and the extent of apoptosis were detected; the anti‑oxidase activity, including superoxide dismutase (SOD) and catalase (CAT), was examined, and the contents of malondiahdehyde (MDA) and nitric oxide (NO) were measured. The phosphorylation levels of endothelial nitric oxide synthase (eNOS), protein kinase B (Akt) and phosphoinositide 3 kinase (PI3K) were detected using western blot analysis. The results demonstrated that pretreatment with 0.01‑1 µmol/l rosuvastatin decreased cell apoptosis caused by ox‑LDL. Notably, pretreatment with 1 µmol/l rosuvastatin for >12 h increased cell viability. Additionally, DAPI staining revealed that rosuvastatin inhibited HUVEC apoptosis. Rosuvastatin treatment also resulted in increased SOD and CAT activities and decreased MDA content in ox‑LDL‑stimulated HUVECs. Furthermore, pretreatment with 0.01‑1 µmol/l rosuvastatin significantly increased` the NO content compared with HUVECs treated with ox‑LDL alone. Western blot analyses demonstrated that rosuvastatin upregulated the phosphorylation of eNOS, Akt and PI3K. These findings indicated that rosuvastatin could protect HUVECs against ox‑LDL‑induced injury through its anti‑oxidant effect and its ability to upregulate the expression of vascular endotheliocyte‑protecting factors.

Rosuvastatin reduces the pro-inflammatory effects of adriamycin on the expression of HMGB1 and RAGE in rats

Rosuvastatin has cardiac protective effects through its anti‑inflammatory effects. The nuclear protein high‑mobility group box 1 (HMGB1) can activate inflammatory pathways when released from dying cells. The present study aimed to investigate the effects of rosuvastatin in adriamycin (ADR)‑treated rats. Adult male rats were randomized to three groups: i) Control group, ii) ADR group, and iii) ADR+rosuvastatin group. Serum biochemical indices were measured using an enzyme‑linked immunosorbent assay. Cardiac function was assessed by echocardiography. The expression of HMGB1 and receptors for advanced glycation end products (RAGE) were assessed by reverse transcription‑quantitative polymerase chain reaction analysis, western blot analysis, and immunohistochemistry. Cytokines were measured using flow cytometry. Rosuvastatin improved the biochemical indices and cardiac morphology and alleviated the pathological lesions. In the ADR+rosuvastatin group, the mRNA and protein levels of HMGB1 and RAGE in the myocardium were significantly lower compared with those in the ADR group (both P<0.05). The results showed that rosuvastatin significantly reduced the levels of HMGB1 and RAGE in the myocardium of the ADR‑treated rats. These results suggest that the protective effects of rosuvastatin may be associated with attenuation of the HMGB1/RAGE‑mediated inflammatory response in ADR‑treated rats. Despite this protective effect of rosuvastatin in the present study, it did not improve cardiac function in terms of the diastolic left ventricular internal dimension, systolic left ventricular internal dimension, left ventricular ejection fraction and left ventricular fractional shortening; this may be due the observation duration being insufficient.

Cellular and molecular approaches to enhance myocardial recovery after myocardial infarction

Reperfusion therapy has resulted in significant improvement in post-myocardial infarction morbidity and mortality in over the last 4 decades. Nonetheless, it is well recognized that simply restoring patency of the epicardial artery may not stop or reverse damage at microvascular level, and myocardial salvage is often suboptimal. Numerous efforts have been undertaken to elucidate the mechanisms underlying extensive myonecrosis to facilitate the discovery of therapies to provide additional and incremental benefits over current therapeutic pathways. To date, conclusively effective strategies to promote myocardial recovery have not yet been established. Novel approaches are investigating the foundational cellular and molecular bases of myocardial ischemia and irreversible injury. Herein, we review the emerging concepts and proposed therapies that may improve myocardial protection and reduce infarct size. We examine the preclinical and clinical evidence for reduced infarct size with these strategies, including anti-inflammatory agents, intracellular ion channel modulators, agents affecting the reperfusion injury salvage kinase (RISK) and nitric oxide signaling pathways, modulators of mitochondrial function, anti-apoptotic agents, and stem cell and gene therapy. We review the potential reasons of failures to date and the potential for new strategies to further promote myocardial recovery and improve prognosis.

Pharmacological postconditioning with atorvastatin calcium attenuates myocardial ischemia/reperfusion injury in diabetic rats by phosphorylating GSK3β

Diabetes is an independent risk factor for myocardial ischemia, and many epidemiological data and laboratory studies have revealed that diabetes significantly exacerbated myocardial ischemia/reperfusion injury and ameliorated protective effects. The present study aimed to determine whether pharmacological postconditioning with atorvastatin calcium lessened diabetic myocardial ischemia/reperfusion injury, and investigated the role of glycogen synthase kinase (GSK3β) in this. A total of 72 streptozotocin-induced diabetic rats were randomly divided into six groups, and 24 age-matched male non-diabetic Sprague-Dawley rats were randomly divided into two groups. Rats all received 40 min myocardial ischemia followed by 180 min reperfusion, except sham-operated groups. Compared with the non-diabetic ischemia/reperfusion model group, the diabetic ischemia/reperfusion group had a comparable myocardial infarct size, but a higher level of serum cardiac troponin I (cTnI) and morphological alterations to their myocardial cells. Compared with the diabetic ischemia/reperfusion group, the group that received pharmacological postconditioning with atorvastatin calcium had smaller myocardial infarct sizes, lower levels of cTnI, reduced morphological alterations to myocardial cells, higher levels of p-GSK3β, heat shock factor (HSF)-1 and heat shock protein (HSP)70. The cardioprotective effect conferred by atorvastatin calcium did not attenuate myocardial ischemia/reperfusion injury following application of TDZD-8, which phosphorylates and inactivates GSK3β. Pharmacological postconditioning with atorvastatin calcium may attenuate diabetic heart ischemia/reperfusion injury in the current context. The phosphorylation of GSK3β serves a critical role during the cardioprotection in diabetic rats, and p-GSK3β may accelerate HSP70 production partially by activating HSF-1 during myocardial ischemic/reperfusion injury.

The potential of stimulating nitric oxide formation in the treatment of hypertension

INTRODUCTION

Hypertension is a leading cause of morbidity and mortality worldwide. A major pathophysiological factor contributing to hypertension is reduced nitric oxide (NO) bioavailability. Strategies to address this pathophysiological mechanism could offer significant advantages. Areas covered: In this review we aimed at examining a variety of drugs (statins, beta-adrenergic receptor blockers, calcium channel blockers, angiotensin converting enzyme inhibitors, angiotensin II type-1 receptor blockers) used to treat hypertension and other cardiovascular diseases, particularly with respect to their potential of increasing NO bioavailability and activity in the cardiovascular system. There is now evidence supporting the notion that many cardiovascular drugs activate NO signaling or enhance NO bioavailability as a contributing mechanism to their beneficial cardiovascular effects. Moreover, other drugs may attenuate NO inactivation by superoxide and other reactive oxygen species by exerting antioxidant effects. More recently, the NO oxidation products nitrite and nitrate have been acknowledged as sources of NO after recycling back to NO. Activation of the nitrate-nitrite-NO pathway is an alternate pathway that may generate NO from both anions and exert antihypertensive effects. Expert opinion: In this review, we provide an overview of the possible mechanisms by which these drugs enhance NO bioavailability and help in the therapy of hypertension.

Impaired endothelial function and arterial stiffness in patients with type 2 diabetes - The effect of a very low-dose combination of fluvastatin and valsartan

AIM

Patients with type 2 diabetes are at increased cardiovascular risk. The aim was to explore whether the impaired arterial wall characteristics typical of these patients could be improved by the unique beneficial effects of a very low-dose combination of fluvastatin and valsartan (low-flu/val).

METHODS

Forty middle-aged males (50.4±6.1years) with type 2 diabetes were recruited to a double-blind, randomized study. Patients (N=20) received low-flu/val (10/20mg) or placebo (N=20) over 30days in addition to their regular therapy. Brachial artery flow mediated dilation (FMD), common carotid artery pulse wave velocity (PWV) and β-stiffness were assessed before and after treatment, and 3 and 6months after treatment discontinuation. The treatment was then repeated.

RESULTS

Arterial wall characteristics significantly improved. After 30days of intervention, FMD increased from 2.4±0.3 to 4.2±0.3 (p<0.001), PWV decreased from 6.4±0.1 to 5.8±0.2 (p<0.001) and β stiffness decreased from 7.8±0.4 to 6.7±0.4 (p<0.001). Lipids and arterial pressure did not change. After treatment discontinuation, the beneficial effects decreased over the following months. The repetition of treatment completely regained the initial benefits. No changes were observed in the placebo group.

CONCLUSIONS

Low-flu/val added on-top of optimal therapy substantially improves arterial wall characteristics in patients with type 2 diabetes.

A review of strategies for infarct size reduction during acute myocardial infarction

Advances in medical and interventional therapy over the last few decades have revolutionized the treatment of acute myocardial infarction. Despite the ability to restore epicardial coronary artery patency promptly through percutaneous coronary intervention, tissue level damage may continue. The reported 30-day mortality after all acute coronary syndromes is 2 to 3%, and around 5% following myocardial infarction. Post-infarct complications such as heart failure continue to be a major contributor to cardiovascular morbidity and mortality. Inadequate microvascular reperfusion leads to worse clinical outcomes and potentially strategies to reduce infarct size during periods of ischemia-reperfusion can improve outcomes. Many strategies have been tested, but no single strategy alone has shown a consistent result or benefit in large scale randomised clinical trials. Herein, we review the historical efforts, current strategies, and potential novel concepts that may improve myocardial protection and reduce infarct size.

Rosuvastatin improves myocardial and neurological outcomes after asphyxial cardiac arrest and cardiopulmonary resuscitation in rats

Rosuvastatin, a potent HMG-CoA reductase inhibitor, is cholesterol-lowering drugs and reduce the risk of myocardial infarction and stroke. This study is to explore whether rosuvastatin improves outcomes after cardiac arrest in rats. Male Sprague-Dawley rats were subjected to 8min of cardiac arrest (CA) by asphyxia and randomly assigned to three experimental groups immediately following successful resuscitation: Sham; Control; and Rosuvastatin. The survival, hemodynamics, myocardial function, neurological outcomes and apoptosis were assessed. The 7-d survival rate was greater in the rosuvastatin treated group compared to the Control group (P=0.019 by log-rank test). Myocardial function, as measured by cardiac output and ejection fraction, was significantly impaired after CA and notably improved in the animals treated with rosuvastatin beginning at 60min after return of spontaneous circulation (ROSC) (P<0.05). Moreover, rosuvastatin treatment significantly ameliorated brain injury after ROSC, which was characterized by the increase of neurological function scores, and reduction of brain edema in cortex and hippocampus (P<0.05). Meanwhile, the levels of cardiac troponin T and neuron-specific enolase and the caspase-3 activity were significantly decreased in the Rosuvastatin group when compared with the Control group (P<0.05). In conclusion, rosuvastatin treatment substantially improves the 7-d survival rate as well as myocardial function and neurological outcomes after ROSC.

Induction of activating transcription factor 3 limits survival following infarct-induced heart failure in mice

Numerous fibrotic and inflammatory changes occur in the failing heart. Recent evidence indicates that certain transcription factors, such as activating transcription factor 3 (ATF3), are activated during heart failure. Because ATF3 may be upregulated in the failing heart and affect inflammation, we focused on the potential role of ATF3 on postinfarct heart failure. We subjected anesthetized, wild-type mice to nonreperfused myocardial infarction and observed a significant induction in ATF3 expression and nuclear translocation. To test whether the induction of ATF3 affected the severity of heart failure, we subjected wild-type and ATF3-null mice to nonreperfused infarct-induced heart failure. There were no differences in cardiac function between the two genotypes, except at the 2-wk time point; however, ATF3-null mice survived the heart failure protocol at a significantly higher rate than the wild-type mice. Similar to the slight favorable improvements in chamber dimensions at 2 wk, we also observed greater cardiomyocyte hypertrophy and more fibrosis in the noninfarcted regions of the ATF3-null hearts compared with the wild-type. Nevertheless, there were no significant group differences at 4 wk. Furthermore, we found no significant differences in markers of inflammation between the wild-type and ATF3-null hearts. Our data suggest that ATF3 suppresses fibrosis early but not late during infarct-induced heart failure. Although ATF3 deficiency was associated with more fibrosis, this did not occur at the expense of survival, which was higher in the ATF3-null mice. Overall, ATF3 may serve a largely maladaptive role during heart failure.

A New Therapeutic Modality for Acute Myocardial Infarction: Nanoparticle-Mediated Delivery of Pitavastatin Induces Cardioprotection from Ischemia-Reperfusion Injury via Activation of PI3K/Akt Pathway and Anti-Inflammation in a Rat Model

Aim

There is an unmet need to develop an innovative cardioprotective modality for acute myocardial infarction (AMI), for which the effectiveness of interventional reperfusion therapy is hampered by myocardial ischemia-reperfusion (IR) injury. Pretreatment with statins before ischemia is shown to reduce MI size in animals. However, no benefit was found in animals and patients with AMI when administered at the time of reperfusion, suggesting insufficient drug targeting into the IR myocardium. Here we tested the hypothesis that nanoparticle-mediated targeting of pitavastatin protects the heart from IR injury.

Methods and Results

In a rat IR model, poly(lactic acid/glycolic acid) (PLGA) nanoparticle incorporating FITC accumulated in the IR myocardium through enhanced vascular permeability, and in CD11b-positive leukocytes in the IR myocardium and peripheral blood after intravenous treatment. Intravenous treatment with PLGA nanoparticle containing pitavastatin (Pitavastatin-NP, 1 mg/kg) at reperfusion reduced MI size after 24 hours and ameliorated left ventricular dysfunction 4-week after reperfusion; by contrast, pitavastatin alone (as high as 10 mg/kg) showed no therapeutic effects. The therapeutic effects of Pitavastatin-NP were blunted by a PI3K inhibitor wortmannin, but not by a mitochondrial permeability transition pore inhibitor cyclosporine A. Pitavastatin-NP induced phosphorylation of Akt and GSK3β, and inhibited inflammation and cardiomyocyte apoptosis in the IR myocardium.

Conclusions

Nanoparticle-mediated targeting of pitavastatin induced cardioprotection from IR injury by activation of PI3K/Akt pathway and inhibition of inflammation and cardiomyocyte death in this model. This strategy can be developed as an innovative cardioprotective modality that may advance currently unsatisfactory reperfusion therapy for AMI.

Atorvastatin at reperfusion reduces myocardial infarct size in mice by activating eNOS in bone marrow-derived cells

Background

The current study was designed to test our hypothesis that atorvastatin could reduce infarct size in intact mice by activating eNOS, specifically the eNOS in bone marrow-derived cells. C57BL/6J mice (B6) and congenic eNOS knockout (KO) mice underwent 45 min LAD occlusion and 60 min reperfusion. Chimeric mice, created by bone marrow transplantation between B6 and eNOS KO mice, underwent 40 min LAD occlusion and 60 min reperfusion. Mice were treated either with vehicle or atorvastatin in 5% ethanol at a dose of 10 mg/kg IV 5 min before initiating reperfusion. Infarct size was evaluated by TTC and Phthalo blue staining.

Results

Atorvastatin treatment reduced infarct size in B6 mice by 19% (p<0.05). In eNOS KO vehicle-control mice, infarct size was comparable to that of B6 vehicle-control mice (p = NS). Atorvastatin treatment had no effect on infarct size in eNOS KO mice (p = NS). In chimeras, atorvastatin significantly reduced infarct size in B6/B6 (donor/recipient) mice and B6/KO mice (p<0.05), but not in KO/KO mice or KO/B6 mice (p = NS).

Conclusions

The results demonstrate that acute administration of atorvastatin significantly reduces myocardial ischemia/reperfusion injury in an eNOS-dependent manner, probably through the post-transcriptional activation of eNOS in bone marrow-derived cells.

Endothelial dysfunction as a nexus for endothelial cell-cardiomyocyte miscommunication

Most studies of the heart focus on cardiomyocytes (CM) at the exclusion of other cell types such as myocardial endothelial cells (EC). Such mono-cellular approaches propagate the presumption that EC provide a mere “passive lining” or supportive role. In fact, EC contribute to a dynamic network regulating vascular tone, cardiac development, and repair. Two distinct EC types, vascular EC and epicardial EC, possess important structural and signaling properties within both the healthy and diseased myocardium. In this review, we address EC-CM interactions in mature, healthy myocardium, followed by a discussion of diseases characterized by EC dysfunction. Finally, we consider strategies to reverse EC-CM “miscommunication” to improve patients' outcomes in various cardiovascular diseases.

Changes in lipoprotein kinetics associated with type 2 diabetes affect the distribution of lipopolysaccharides among lipoproteins

CONTEXT

Lipopolysaccharides (LPSs) are inflammatory components of the outer membrane of Gram-negative bacteria and, in plasma, are mostly associated with lipoproteins. This association is thought to promote their catabolism while reducing their proinflammatory effects.

OBJECTIVES

Our aim was to determine the impact of lipoprotein kinetics on plasma LPS distribution and how it may affect patients with type 2 diabetes mellitus (T2DM).

DESIGN

We performed a kinetic study in 30 individuals (16 T2DM patients, 14 controls) and analyzed the impact of changes in lipoprotein kinetics on LPS distribution among lipoproteins.

RESULTS

Plasma LPS levels in T2DM patients were not different from those in controls, but LPS distribution in the two groups was different. Patients with T2DM had higher LPS-very low-density lipoprotein (VLDL; 31% ± 7% vs 22% ± 11%, P = .002), LPS-high-density lipoprotein (HDL; 29% ± 9% vs 19% ± 10%, P = .015), free (nonlipoprotein bound) LPS (10% ± 4% vs 7% ± 4%, P = .043) and lower LPS-low-density lipoprotein (LDL; 30% ± 13% vs 52% ± 16%, P = .001). In multivariable analysis, VLDL-LPS was associated with HDL-LPS (P < .0001); LDL-LPS was associated with VLDL-LPS (P = .004), and VLDL apolipoprotein (apo) B100 catabolism (P = .002); HDL-LPS was associated with free LPS (P < .0001) and VLDL-LPS (P = .033); free LPS was associated with HDL-LPS (P < .0001). In a patient featuring a dramatic decrease in VLDL catabolism due to apoA-V mutation, LDL-LPS was severely decreased (0.044 EU/mL vs 0.788 EU/mL in controls). The difference between T2DM patients and controls for LDL-LPS fraction was no longer significant after controlling for VLDL apoB100 total fractional catabolic rate.

CONCLUSIONS

Our data suggest that in humans, free LPS transfers first to HDL and then to VLDL, whereas the LPS-bound LDL fraction is mainly derived from VLDL catabolism; the latter may hence represent a LPS catabolic pathway. T2DM patients show lower LDL-LPS secondary to reduced VLDL catabolism, which may represent an impaired catabolic pathway.

Hypercholesterolemia: its impact on ischemia-reperfusion injury

Ischemic diseases are a leading cause of death worldwide. It is becoming increasingly appreciated that atherosclerosis is a major cause of ischemia reperfusion. Hypercholesterolemia is a major risk factor for the development of atherosclerosis, and is associated with an increased incidence of ischemia reperfusion. Furthermore, elevated cholesterol levels exacerbate the vascular responses to ischemia-reperfusion, which intensifies the resulting organ dysfunction. One of the underlying features of both ischemia-reperfusion injury and hypercholesterolemia is the proinflammatory and prothrombogenic phenotype invoked in the microvasculature. This is manifested as an endothelial dysfunction, characterized by leukocyte and platelet recruitment, oxidative stress and angiotensin II receptor Type 1a activation. These common pathways of inflammation offer attractive targets for the development of drugs to combat cardiovascular disease and the associated ischemic disorders.

Postconditioning with rosuvastatin reduces myocardial ischemia-reperfusion injury by inhibiting high mobility group box 1 protein expression

High mobility group box 1 protein (HMGB1) plays an important role in myocardial ischemia-reperfusion (I/R) injury. Rosuvastatin (RS) preconditioning has been reported to reduce myocardial I/R injury. The aim of this study was to investigate whether postconditioning with RS is able to reduce myocardial I/R injury by inhibiting HMGB1 expression in rats. Anesthetized male rats were subjected to ischemia for 30 min and treated once with RS (10 mg/kg, i.v.) 5 min prior to reperfusion for 4 h. Lactate dehydrogenase (LDH), creatine kinase (CK) and superoxide dismutase (SOD) activities, malondialdehyde (MDA) levels and infarct size were measured. HMGB1 expression was assessed by immunoblotting. The results showed that RS postconditioning significantly decreased the infarct size and the activities of LDH and CK following 4 h reperfusion (all P<0.05). RS postconditioning also significantly inhibited the increase of MDA levels and the reduction of SOD activity (both P<0.05). RS postconditioning was able to significantly inhibit the HMGB1 expression induced by I/R. The present study suggested that postconditioning with RS reduces myocardial I/R injury, which may be associated with the inhibition of HMGB1 expression.

Rosuvastatin-regulated post-translational phosphoproteome in human umbilical vein endothelial cells

Statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, are widely prescribed as cholesterol-lowering drugs. Statins have recently been found to have pleiotropic effects that are independent of their lipid-lowering properties. Phosphorylation of serine, threonine, and tyrosine residues of functional proteins are considered to be important in the endothelial signaling cascade. In this study, protein phosphorylation status in human umbilical vein endothelial cells (ECs) after rosuvastatin treatment was examined. The proteins were collected from rosuvastatin-treated ECs and then the phosphorylated peptides purified by a Fe(3+)-immobilized metal-affinity chromatography bead system were examined by liquid chromatography-tandem mass spectrometry analysis. Alterations of the phosphorylation status of proteins were noticed after rosuvastatin treatment. There were 277 and 530 phosphorylated proteins identified from the control and rosuvastatin-treated ECs, respectively. Among those proteins, T78, in addition to S156 of the Ras-GTPase-activating protein, was phosphorylated after rosuvastatin treatment. Rosuvastatin reduced the phosphorylation of Y455 in HSP90 protein. Decreased phosphorylation of T211 with a concurrent increase in the T291 phosphorylation of Akt1 was observed under rosuvastatin treatment. Increased S633 phosphorylation was detected in endothelial nitric oxide synthase. Western blot analysis further showed an earlier and greater S633 phosphorylation than that of S1177 in endothelial nitric oxide synthase after rosuvastatin treatment. Changes in the phosphorylation status of these proteins may alter the protein's function and affect endothelial physiology. The current study provides new insights leading to a better understanding of the pleiotropic effects of statins on the vascular system.

Low-dose rosuvastatin improves the functional and morphological markers of atherosclerosis in asymptomatic postmenopausal women with dyslipidemia

OBJECTIVE

Several large-scale studies have shed light on the primary preventive efficacy of statins against atherosclerotic diseases in the course of treatment of dyslipidemia. However, this efficacy in the management of dyslipidemia in relatively low-risk patients, particularly in women, has not been clarified. Here, we investigated the efficacy of dyslipidemia treatment with a statin on three indices that are widely used to assess atherosclerosis in postmenopausal women: carotid intima-media thickness (CIMT), arterial stiffness index β of the common carotid artery (carotid stiffness β), and brachial artery pulse wave velocity (baPWV).

METHODS

The study enrolled 51 postmenopausal women aged 55 years or older with dyslipidemia. The participants were randomly divided into two treatment groups and received a single daily administration of 2.5 mg of rosuvastatin or no statin therapy as control.

RESULTS

At baseline, the groups did not significantly differ with regard to the three indices. At the third and 12th months of treatment, both carotid stiffness β and baPWV values were significantly lower than those of the control group. As for CIMT, the value was significantly lower in the statin group than in the control group at 12 months of treatment. These changes were in conjunction with a significant decrease in low-density lipoprotein cholesterol. Interestingly, changes in CIMT during the 12-month period were significantly correlated with changes in high-sensitivity C-reactive protein during the 3-month period independently of lipid profile.

CONCLUSIONS

The potent statin improves baPWV and carotid stiffness β, in addition to CIMT (surrogate markers of coronary artery disease), in postmenopausal women with low-risk dyslipidemia. Further studies to clarify the common mechanisms underlying the link between cholesterol-lowering therapy and atherosclerosis in postmenopausal women are required.

Possible involvement of PPARγ-associated eNOS signaling activation in rosuvastatin-mediated prevention of nicotine-induced experimental vascular endothelial abnormalities

Nicotine exposure via cigarette smoking and tobacco chewing is associated with vascular complications. The present study investigated the effect of rosuvastatin in nicotine (2 mg/kg/day, i.p., 4 weeks)-induced vascular endothelial dysfunction (VED) in rats. The development of VED was assessed by employing isolated aortic ring preparation and estimating aortic and serum nitrite/nitrate concentration. Further, scanning electron microscopy and hematoxylin-eosin staining of thoracic aorta were performed to assess the vascular endothelial integrity. Moreover, oxidative stress was assessed by estimating aortic superoxide anion generation and serum thiobarbituric acid-reactive substances. The nicotine administration produced VED by markedly reducing acetylcholine-induced endothelium-dependent relaxation, impairing the integrity of vascular endothelium, decreasing aortic and serum nitrite/nitrate concentration, increasing oxidative stress, and inducing lipid alteration. However, treatment with rosuvastatin (10 mg/kg/day, i.p., 4 weeks) markedly attenuated nicotine-induced vascular endothelial abnormalities, oxidative stress, and lipid alteration. Interestingly, the co-administration of peroxisome proliferator-activated receptor γ (PPARγ) antagonist, GW9662 (1 mg/kg/day, i.p., 2 weeks) submaximally, significantly prevented rosuvastatin-induced improvement in vascular endothelial integrity, endothelium-dependent relaxation, and nitrite/nitrate concentration in rats administered nicotine. However, GW9662 co-administration did not affect rosuvastatin-associated vascular anti-oxidant and lipid-lowering effects. The incubation of aortic ring, isolated from rosuvastatin-treated nicotine-administered rats, with L-NAME (100 μM), an inhibitor of nitric oxide synthase (NOS), significantly attenuated rosuvastatin-induced improvement in acetylcholine-induced endothelium-dependent relaxation. Rosuvastatin prevents nicotine-induced vascular endothelial abnormalities by activating PPARγ and endothelial NOS signaling pathways. Moreover, the PPARγ-independent anti-oxidant and lipid-lowering effects of rosuvastatin might additionally play a role in the improvement of vascular endothelial function.

A low-dose atorvastatin and losartan combination directly improves aortic ring relaxation and diminishes ischaemic-reperfusion injury in isolated rat hearts

Background

The cardiovascular pleiotropic effects of statins and angiotensin receptor blockers (ARBs) could be of interest for innovative preventive approaches. We aimed to investigate whether low-dose atorvastatin and losartan, separately not possessing protective cardiovascular pleiotropic effects, express them when combined.

Material/Methods

Forty-five adult male Wistar rats were anaesthetized and their thoracic aortas and hearts were isolated. Relaxation of aortic rings, coronary flow rate and the extent of myocardial ischaemic-reperfusion injury were measured. Different concentrations (0.01, 0.1, 1.0 μM) of atorvastatin and losartan added to a perfusion medium were first tested. The separate drugs, which were ineffective, were then combined at the same concentrations and the concentration was tested in the same model.

Results

Low concentrations of atorvastatin or losartan (0.1 and 1 μM, respectively) produced no effects in isolated aorta. However, surprisingly, when these drug concentrations were combined, a significantly improved endothelium-dependent relaxation of the thoracic aorta was observed. Similarly, when combining individually ineffective concentrations of atorvastatin or losartan (0.01 and 0.1 μM, respectively), significantly increased coronary flow and a decreased extent of myocardial injury were observed. By using a nitric oxide-synthase inhibitor, we demonstrated that the vasodilatory effects obtained were nitric oxide-dependent. The degree of effectiveness by the combination was comparable to that obtained by 10-fold (atorvastatin) or 100-fold (losartan) higher concentrations of the separate drugs.

Conclusions

Our results revealed that remarkable additive/synergistic effects exist between low-doses of a statin (atorvastatin) and an ARB (losartan), resulting in important cardiovascular protection. This new concept could be valuable in cardiovascular prevention.

Targeting reperfusion injury in acute myocardial infarction: a review of reperfusion injury pharmacotherapy

INTRODUCTION

Acute myocardial infarction (AMI) (secondary to lethal ischemia-reperfusion [IR]) contributes to much of the mortality and morbidity from ischemic heart disease. Currently, the treatment for AMI is early reperfusion; however, this itself contributes to the final myocardial infarct size, in the form of what has been termed 'lethal reperfusion injury'. Over the last few decades, the discovery of the phenomena of ischemic preconditioning and postconditioning, as well as remote preconditioning and remote postconditioning, along with significant advances in our understanding of the cardioprotective pathways underlying these phenomena, have provided the possibility of successful mechanical and pharmacological interventions against reperfusion injury.

AREAS COVERED

This review summarizes the evidence from clinical trials evaluating pharmacological agents as adjuncts to standard reperfusion therapy for ST-elevation AMI.

EXPERT OPINION

Reperfusion injury pharmacotherapy has moved from bench to bedside, with clinical evaluation and ongoing clinical trials providing us with valuable insights into the shortcomings of current research in establishing successful treatments for reducing reperfusion injury. There is a need to address some key issues that may be leading to lack of translation of cardioprotection seen in basic models to the clinical setting. These issues are discussed in the Expert opinion section.

The role of nitric oxide on rosuvastatin-mediated S-nitrosylation and translational proteomes in human umbilical vein endothelial cells

Background

The pleiotropic effects of 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), which are independent from their cholesterol-lowering action, have been widely recognized in various biological systems. Statins can affect endothelial homeostasis, which is partly modulated by the production of nitric oxide (NO). However, it is unclear how statin/NO-mediated posttranslational S-nitrosylation of endothelial proteins and changes in translational profiles may benefit endothelial integrity. Therefore, it is important to understand the statin/NO-mediated S-nitrosylation in endothelial cells.

Results

Rosuvastatin treatment of human umbilical vein endothelial cells (ECs) enhanced the enzymatic activity of endothelial nitric oxide synthase (eNOS) and the expression of 78 S-nitrosoproteins. Among these S-nitrosoproteins, we identified 17 proteins, including protein disulfide bond isomerase, phospholipase C, transaldolase and heat shock proteins. Furthermore, a hydrophobic Cys66 was determined as the S-nitrosylation site of the mitochondrial HSP70. In addition to the statin-modulated posttranslational S-nitrosylation, changes in the NO-mediated translational proteome were also observed. Seventeen major proteins were significantly upregulated after rosuvastatin treatment. However, 12 of these proteins were downregulated after pretreating ECs with an eNOS inhibitor (L-NAME), which indicated that their expression was modulated by NO.

Conclusions

ECs treated with rosuvastatin increase eNOS activation. The increased NO production is involved in modulating S-nitrosylation and translation of proteins. We provide further evidence of the pleiotropic effect of rosuvastatin on endothelial physiology.

Early statin treatment prior to primary PCI for acute myocardial infarction: REPERATOR, a randomized placebo-controlled pilot trial

OBJECTIVE

The aim of this pilot study was to determine whether early atorvastatin treatment will reduce left ventricle (LV) remodeling, infarct size, and improve microvascular perfusion.

BACKGROUND

In animal studies, early statin therapy reduces reperfusion injury after a percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI).

METHODS

Forty-two consecutive patients (82% male, mean age 61.2 ± 9.8) who underwent a primary PCI for a first ST-elevated AMI were randomized for pretreatment with atorvastatin 80 mg (n = 20) or placebo (n = 22) and continued with the same dosage daily for 1 week. All patients received atorvastatin 80 mg once daily 7 days after primary PCI. The LV function and infarct size were measured by magnetic resonance imaging within 1 day, at 1 week, and 3 months follow up. The primary endpoint was the end-systolic volume index (ESVI) at 3 months. Secondary endpoints were global LV function measurements, myocardial infarct size, biochemical cardiac markers, TIMI flow, and ST-T elevation resolution.

RESULTS

ESVI 3 months after AMI was 25.1 mL/m(2) in the atorvastatin arm and 25.0 mL/m(2) in the placebo arm (P = 0.74). The differences in change from baseline to 3 months follow up in global LV function and myocardial infarct size did not differ between both treatment arms. Furthermore, biochemical markers, TIMI flow, and ST-T elevation resolution did not differ between atorvastatin and placebo arm.

CONCLUSIONS

In this pilot study, pretreatment with atorvastatin in an acute myocardial infarction does not result in an improved cardiac function, microvascular perfusion, or decreased myocardial infarct size.

A transgenic mouse model expressing exclusively human hemoglobin E: indications of a mild oxidative stress

Hemoglobin (Hb) E (β26 Glu→Lys) is the most common abnormal hemoglobin (Hb) variant in the world. Homozygotes for HbE are mildly thalassemic as a result of the alternate splice mutation and present with a benign clinical picture (microcytic and mildly anemic) with rare clinical symptoms. Given that the human red blood cell (RBC) contains both HbE and excess α-chains along with minor hemoglobins, the consequence of HbE alone on RBC pathophysiology has not been elucidated. This becomes critical for the highly morbid β(E)-thalassemia disease. We have generated transgenic mice exclusively expressing human HbE (HbEKO) that exhibit the known aberrant splicing of β(E) globin mRNA, but are essentially non-thalassemic as demonstrated by RBC α/β (human) globin chain synthesis. These mice exhibit hematological characteristics similar to presentations in human EE individuals: microcytic RBC with low MCV and MCH but normal MCHC; target RBC; mild anemia with low Hb, HCT and mildly elevated reticulocyte levels and decreased osmotic fragility, indicating altered RBC surface area to volume ratio. These alterations are correlated with a mild RBC oxidative stress indicated by enhanced membrane lipid peroxidation, elevated zinc protoporphyrin levels, and by small but significant changes in cardiac function. The C57 (background) mouse and full KO mouse models expressing HbE with the presence of HbS or HbA are used as controls. In select cases, the HbA full KO mouse model is compared but found to be limited due to its RBC thalassemic characteristics. Since the HbEKO mouse RBC lacks an abundance of excess α-chains that would approximate a mouse thalassemia (or a human thalassemia), the results indicate that the observed in vivo RBC mild oxidative stress arises, at least in part, from the molecular consequences of the HbE mutation.

Low-density lipoprotein receptor gene transfer in hypercholesterolemic mice improves cardiac function after myocardial infarction

Left ventricular (LV) function post-myocardial infarction (MI) is adversely influenced by hypercholesterolemia independent of the severity of coronary atherosclerosis. The objective of this study was to evaluate whether lipid lowering by adenoviral low-density lipoprotein (LDL) receptor (AdLDLr) gene transfer in C57BL/6 LDL receptor (LDLr)-deficient mice beneficially affects ventricular remodeling and cardiac function post-MI independent of effects on the coronary circulation. AdLDLr transfer reduced plasma cholesterol by 77% (P<0.0001). Survival 28 days post-MI was higher in AdLDLr-treated mice (95%) compared with control mice (80%) (P<0.05) (hazard ratio for mortality 0.26, 95% confidence interval 0.11–0.84). Infarct size was not significantly different at day 1 and day 7 but was reduced by 18% (P<0.05) at day 28 in AdLDLr MI mice compared with control MI mice. Cardiomyocyte hypertrophy and interstitial fibrosis were reduced and neovascularization was increased in AdLDLr MI mice. LDLr gene transfer had beneficial effects on endothelial progenitor cell (EPC) number and ex vivo EPC function. LV contractility and relaxation were better preserved in AdLDLr MI mice compared with control MI mice. In conclusion, lipid lowering in hypercholesterolemic mice exerts direct cardioprotective effects resulting in enhanced survival, reduced infarct size, decreased ventricular remodeling and better cardiac function.

Synergism between melatonin and atorvastatin against endothelial cell damage induced by lipopolysaccharide

The beneficial effects of atorvastatin are based on both cholesterol-dependent and independent mechanisms. The latter probably include the ability of the estatin to enhance the expression of endothelial nitric oxide synthase (eNOS) and to cause a vasodilatation. In turn, the antioxidant and anti-inflammatory actions of melatonin are related to its vascular protection. In the present study, we investigated the efficacy of the combination of melatonin plus atorvastatin against endothelial cell damage induced by inflammation and oxidative stress injury. Human umbilical vein endothelial cells (HUVEC) were cultured with bacterial lipopolysaccharide (LPS) in the presence or absence of melatonin and/or atorvastatin. LPS inhibited eNOS mRNA and protein expression, which was reversed by atorvastatin and, to a lesser extent, by melatonin. Together, melatonin + atorvastatin induced higher eNOS protein expression than either compound alone. Melatonin, but not atorvastatin, reduced free radical generation, lipid peroxidation, and interleukin-6 levels induced by LPS. In the presence of atorvastatin, the effects of melatonin were maintained or even improved. These data suggest that melatonin improves the beneficial effects of atorvastatin and reduces its side effects in endothelial cells during inflammation and under conditions of oxidative stress.

Early postoperative statin therapy is associated with a lower incidence of acute kidney injury after cardiac surgery

OBJECTIVE

To test the hypothesis that perioperative statin use reduces acute kidney injury (AKI) after cardiac surgery.

DESIGN

A retrospective analysis of prospectively collected data from an ongoing clinical trial.

SETTING

A quaternary-care university hospital.

PARTICIPANTS

Three hundred twenty-four adult elective cardiac surgery patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The authors assessed the association of preoperative statin use, early postoperative statin use, and acute statin withdrawal with the incidence of AKI. Early postoperative statin use was defined as statin treatment within the first postoperative day. Statin withdrawal was defined as the discontinuation of preoperative statin treatment before surgery until at least postoperative day 2. Logistic regression and propensity score modeling were used to control for AKI risk factors. Sixty-eight of 324 patients (21.0%) developed AKI. AKI patients stayed in the hospital longer (p = 0.03) and were more likely to develop pneumonia (p = 0.002) or die (p = 0.001). A higher body mass index (p = 0.003), higher central venous pressure (p = 0.03), and statin withdrawal (27.4 v 14.7%, p = 0.046) were associated with a higher incidence of AKI, whereas early postoperative statin use was protective (12.5% v 23.8%, p = 0.03). Preoperative statin use did not affect the risk of AKI. In multivariate logistic regression, age (p = 0.03), male sex (p = 0.02), body mass index (p < 0.001), and early postoperative statin use (odds ratio = 0.32; 95% confidence interval, 0.14-0.72; p = 0.006) independently predicted AKI. Propensity score-adjusted risk assessment confirmed the association between early postoperative statin use and reduced AKI (odds ratio = 0.30; 95% confidence interval, 0.13-0.70; p = 0.005).

CONCLUSIONS

Early postoperative statin use is associated with a lower incidence of AKI among both chronic statin users and statin-naive cardiac surgery patients.

Augmented O-GlcNAc signaling attenuates oxidative stress and calcium overload in cardiomyocytes

O-linked β-N-acetylglucosamine (O-GlcNAc) is an inducible, dynamically cycling and reversible post-translational modification of Ser/Thr residues of nucleocytoplasmic and mitochondrial proteins. We recently discovered that O-GlcNAcylation confers cytoprotection in the heart via attenuating the formation of mitochondrial permeability transition pore (mPTP) and the subsequent loss of mitochondrial membrane potential. Because Ca(2+) overload and reactive oxygen species (ROS) generation are prominent features of post-ischemic injury and favor mPTP formation, we ascertained whether O-GlcNAcylation mitigates mPTP formation via its effects on Ca(2+) overload and ROS generation. Subjecting neonatal rat cardiac myocytes (NRCMs, n ≥ 6 per group) to hypoxia, or mice (n ≥ 4 per group) to myocardial ischemia reduced O-GlcNAcylation, which later increased during reoxygenation/reperfusion. NRCMs (n ≥ 4 per group) infected with an adenovirus carrying nothing (control), adenoviral O-GlcNAc transferase (adds O-GlcNAc to proteins, AdOGT), adenoviral O-GlcNAcase (removes O-GlcNAc to proteins, AdOGA), vehicle or PUGNAc (blocks OGA; increases O-GlcNAc levels) were subjected to hypoxia-reoxygenation or H(2)O(2), and changes in Ca(2+) levels (via Fluo-4AM and Rhod-2AM), ROS (via DCF) and mPTP formation (via calcein-MitoTracker Red colocalization) were assessed using time-lapse fluorescence microscopy. Both OGT and OGA overexpression did not significantly (P > 0.05) alter baseline Ca(2+) or ROS levels. However, AdOGT significantly (P < 0.05) attenuated both hypoxia and oxidative stress-induced Ca(2+) overload and ROS generation. Additionally, OGA inhibition mitigated both H(2)O(2)-induced Ca(2+) overload and ROS generation. Although AdOGA exacerbated both hypoxia and H(2)O(2)-induced ROS generation, it had no effect on H(2)O(2)-induced Ca(2+) overload. We conclude that inhibition of Ca(2+) overload and ROS generation (inducers of mPTP) might be one mechanism through which O-GlcNAcylation reduces ischemia/hypoxia-mediated mPTP formation.

Inhibition of the renal renin-angiotensin system and renoprotection by pitavastatin in type1 diabetes

1. The aim of the present study was to investigate whether or not pitavastatin ameliorates diabetic nephropathy and if inhibition of the rennin-angiotensin-aldosterone system (RAAS) is associated with any renoprotective effects. Pitavastatin (10mg/ kg/day) and/or spironolactone (100mg/kg/day) were given by gavage for 3weeks to uninephrectomized rats with streptozotocin-induced diabetes. 2. Pitavastatin or spironolactone significantly reduced proteinuria and collagen deposition, and normalized creatinine clearance, serum creatinine levels and blood urea nitrogen concentrations. 3. Reverse transcription polymerase chain reaction analysis showed that the renal expression of collagenI, transforming growth factor-β and monocyte chemoattractant-1 were increased in diabetic rats and reduced by the pitavastatin and/or spironolactone treatment. 4. These agents also decreased angiotensin converting enzyme expression and aldosterone concentrations in the renal homogenate, but had no effect on blood glucose, haemoglobinA(1c) , and plasma total cholesterol, Na(+) , K(+) , aldosterone and NOx levels, or on systolic blood pressure measured by the tail-cuff method. Interestingly, cotreatment with pitavastatin and spironolactone did not result in additional normalization. 5. These results suggest that pitavastatin shows renoprotective effects against diabetic nephropathy mediated in part by inhibition of the renal RAAS, including the suppression of angiotensin-converting enzyme expression and aldosterone production.

Rosuvastatin protects tissue perfusion in the experimental testicular torsion model

Recently, anti-inflammatory and tissue protective effects of statins have been shown independent from its anti-hyperlipidemic effect. It has been shown that one of the statins, rosuvastatin, may reduce ischemia/reperfusion (I/R)-induced tissue injury in the brain, intestines, and heart. We planned an experimental study to evaluate the effect of rosuvastatin on I/R injury encountered after the detorsion of the testicular torsion. Rats were divided into three groups. In group 1, testis basal blood flow (basal value) was measured with LASER Doppler flowmeter (LDF). Testis was relocated into the scrotum without torsion. Two and 3 h after the basal measurement, testis was brought out from the same incision, and the second (second value) and third (third value) testicular blood flow measurements were done, respectively. In group 2, after the measurement of basal value testicular torsion was created. Second and third value measurements were obtained with LDF at the end of the 2 h of testicular torsion just before the detorsion and 1 h after detorsion. In group 3, same procedures in torsion/detorsion group were repeated in this group, but 10 mg/kg rosuvastatin was injected intraperitoneally 30 min before detorsion. Second values in groups 2 and 3 were significantly lower than group 1. Third values were significantly low in group 2 compared to groups 1 and 3. Regarding the third measurement, there was no significant difference between the groups 1 and 3. Tissue injury is closely related with condition of microvascular perfusion after I/R. Rosuvastatin can protect tissue perfusion in the experimental testicular torsion model.

Reversal of voltage-dependent erectile responses in the Zucker obese-diabetic rat by rosuvastatin-altered RhoA/Rho-kinase signaling

INTRODUCTION

The combination of independent risk factors for erectile dysfunction, obesity, hypertension, and diabetes are collectively manifested in a condition known as metabolic syndrome X (MSX). However, the regulatory mechanisms responsible for the erectile dysfunction (ED) are not fully understood. Clinical studies suggest that a pleiotropic effect of statin's ability to enhance vascular relaxation might be through an impact on nitric oxide signaling or through a regulation of RhoA activation.

AIM

We hypothesized that regulatory aspects of short-term statin therapy involve the alteration of the RhoA/Rho-kinase signaling cascade and will reverse the ED seen in a rat model of MSX.

MAIN OUTCOME MEASURES

The magnitude and sensitivity of the voltage-dependent maintenance of intracavernosal blood pressure and mean arterial blood pressure. These responses were correlated with tissue protein and mRNA expression levels of RhoA and Rho kinases.

METHODS

Erectile function was evaluated by assessing voltage-dependent stimulation of the cavernosal nerve in 16-20 weeks old lean and obese-diabetic Zucker rats treated with 5 mg/kg/day of rosuvastatin intraperitoneally for 3 days. Cavernosal tissue RhoA and Rho-kinases expression levels were evaluated by real-time reverse transcriptase-polymerase chain reaction, Western blot.

RESULTS

The voltage-dependent erectile responses were suppressed by >30% in the obese-diabetic Zucker rat. The 3-day treatment with rosuvastatin partially restored the erectile response. The Rho-kinase inhibitor, H-1152, dose dependently increased the erectile responses and shifted the voltage sensitivity with statin treatment. Analysis of protein expression levels suggested elevation of RhoA and Rho kinases in obese-diabetics and statin treatment lowering Rho-kinase II. The RhoA and Rho-kinase II mRNA levels were significantly reduced in the rosuvastatin-treated obese-diabetic animals.

CONCLUSIONS

These results support a hypothesis that short-term statin therapy may lower RhoA/Rho-kinase expression levels and improve cavernosal blood pressure response to Rho-kinase inhibition and voltage-stimulation, and reversing an augmented vasoconstricted state associated with diabetes and/or hypertension in MSX.

The role of nitric oxide in myocardial repair and remodeling

Nitric oxide (NO) plays a crucial role in many aspects of the pathophysiology of heart failure. NO is a double-edged sword; NO inhibits ischemia/reperfusion (I/R) injury, represses inflammation, and prevents left ventricular (LV) remodeling, whereas excess NO and co-existence of reactive oxygen species (ROS) with NO are injurious. The failing heart is exposed to not only oxidative stress by a plethora of humoral factors and inflammatory cells but also nitrosative stress. Activation of nitric oxide synthase (NOS) of any isoforms, [i.e., endothelial NOS (eNOS), inducible NOS (iNOS), and neuronal NOS (nNOS)], concomitant with oxidative stress results in NOS uncoupling, leading to further oxidative/nitrosative stress. Indiscriminate removal of oxidative stress is not an effective means to prevent this detrimental process, because oxidative stress is necessary for an adaptive mechanism for cell survival against noxious stimuli. Therefore, removal of ROS in a site-specific manner or inhibition of the source of injurious ROS without affecting redox-sensitive survival signal transduction pathways represents a promising approach to elicit the beneficial effect of NO. Recent emerging pharmacological tools and regular exercise inhibit ROS generation in the proximity of NOSs, thereby increasing bioavailable NO and exerting cardioprotection against I/R injury and LV remodeling.

Beneficial effect of rosuvastatin on cardiac dysfunction is associated with alterations in calcium-regulatory proteins

AIMS

The normal expression of Ca(2+)-regulatory protein is critical for efficient myocardial function. The present study tested the hypothesis that rosuvastatin treatment may attenuate left ventricular (LV) remodelling and dysfunction in the failing heart, which may be associated with alterations of Ca(2+)-regulatory protein.

METHODS AND RESULTS

We investigated the change of LV remodelling and function in a rat model of cardiac dysfunction due to myocardial infarction (MI) with or without rosuvastatin (10 mg/kg/day) treatment for 10 weeks. The protein expression of sarcoplasmic reticulum Ca(2+) ATPase (SERCA)2a, phospholamban (PLB), and phospho-PLB at serine-16 (pSer16-PLB), as well as SERCA activity, interleukin (IL)-6, and IL-10 levels were evaluated. After rosuvastatin treatment, LV remodelling and dysfunction were prevented. Rosuvastatin prevented the decrease of SERCA2a and pSer16-PLB expression, increased SERCA activity, but showed no effect on PLB expression. Furthermore, rosuvastatin reduced the increased IL-6 level and further elevated IL-10 level in the peri-infarct and remote zones of MI. Serum lipid levels remained unchanged.

CONCLUSION

Rosuvastatin is effective in preventing LV remodelling and dysfunction in the failing heart. The molecular mechanism may be related to normalization of SERCA2a expression, SERCA activity, and pSer16-PLB levels, as well as through cytokine alterations independent of its lipid-lowering effect.

Effect of atorvastatin on expression of IL-10 and TNF-alpha mRNA in myocardial ischemia-reperfusion injury in rats

Myocardial ischemia and reperfusion (MI/R) is associated with an intense inflammatory reaction, which may lead to myocyte injury. Because statins protect the myocardium against ischemia-reperfusion injury via a mechanism unrelated to cholesterol lowering, we hypothesized that the protective effect of statins was related to the expression of TNF-alpha (TNF-alpha) and interleukin-10 (IL-10) mRNA. Seventy-two rats were randomly divided into three groups as follows: sham, I/R and I/R+atorvastatin. Atorvastatin (20 mg kg(-1)day(-1)) treatment was administered daily via oral gavage to rats for 2, 7 or 14 days. Ischemia was induced via a 30-min coronary occlusion. Reperfusion was allowed until 2, 7 or 14 days while atorvastatin treatment continued. We measured infarct size, hemodynamics and the plasma levels and the mRNA expression of TNF-alpha and IL-10 in the three groups. We demonstrated that the up-regulation of expression of both TNF-alpha mRNA and IL-10 mRNA was associated the increased plasma levels of TNF-alpha and IL-10 in the ischemic and reperfused myocardium compared with that in the sham group (P<0.01). Atorvastatin treatment prevented ischemia-reperfusion-induced up-regulation of both TNF-alpha and IL-10 mRNA, and improved left ventricular function (P<0.01). Our findings suggested that atorvastatin may attenuate MI/R and better recovery of left ventricle function following ischemia and reperfusion and IL-10 was not directly likely involved in this protective mechanism.

Effect of previous treatment with statins on outcome of patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention

Beyond lipid-lowering effects, statins have favorable effects on platelets, endothelial function, plaque stability, and inflammation. These "pleiotropic" effects could contribute to microvascular function preservation during ischemia. Data are limited about the impact of previous treatment with statins on outcomes of patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI). Accordingly, the aim was to evaluate the effect of previous statin treatment on clinical outcomes of such patients. A total of 950 consecutive patients with STEMI treated with primary PCI who were included in our primary PCI registry from January 2001 to July 2007 were studied. Excluded were patients with cardiogenic shock. Patients were allocated into 2 groups: those who received previous statin treatment (n=327) and those who did not (n=623). Patients who received previous statin treatment were older and more likely to be women; have diabetes, hypertension, hyperlipidemia, renal insufficiency, and anemia; or have had a previous myocardial infarction. Procedural characteristics were similar between the 2 groups. Despite the higher risk profile, patients who received previous statin treatment had a lower 30-day mortality rate (1.5% vs 3.8%; p=0.05). However, at 6 months, mortality differences were no longer evident and patients who received previous statin therapy had a higher rate of target-vessel revascularization (12.4% vs 7.6%; p=0.02). Multivariate analysis showed that previous statin treatment was associated with an odds ratio of 0.4 (95% confidence interval 0.13 to 0.96, p=0.045) for 30-day mortality. In conclusion, the present study suggested that previous therapy with statins in patients with STEMI treated using primary PCI may be associated with reduced short-term mortality.

Relation between previous lipid-lowering therapy and infarct size (creatine kinase-MB level) in patients presenting with acute myocardial infarction

Animal experimental data have shown that lipid-lowering agents reduce myocardial infarct size. This association has not been well studied in humans. We compared infarct size in 10,548 patients in the GUSTO IIb and PURSUIT trials who were (n = 1,028) or were not (n = 9,520) on lipid-lowering therapy before an enrolling myocardial infarction (MI). Patients using lipid-lowering agents before their index MI had smaller infarcts than those who were not using these agents (median peak creatine kinase [CK]-MB 4.2 vs 5.2 times the upper limit of normal [ULN]; p <0.0001). Similarly, in an unadjusted model, patients on previous lipid-lowering therapy were less likely to have a peak CK-MB >3 times the ULN (620 of 1,028 [60.3%] vs 6,486 of 9,520 patients [68.1%]; p <0.001; relative risk 0.88, 95% confidence interval 0.84 to 0.93, p <0.0001). In a covariate- and propensity-adjusted multivariable model, the association between pretreatment with lipid-lowering agents and smaller infarct size persisted (relative risk for CK-MB >3 times the ULN 0.94, 95% confidence interval 0.88 to 0.99, p = 0.04). In conclusion, patients on lipid-lowering agents before an MI had significantly smaller infarcts. These findings suggest that lipid-lowering therapy may exert additional salutary effects in the setting of acute coronary syndromes.