Effects of hydroxymethylglutaryl coenzyme A reductase inhibitor simvastatin on smooth muscle cell proliferation in vitro and neointimal formation in vivo after vascular injury

Metabolic reprogramming in skin wound healing

Metabolic reprogramming refers to the ability of a cell to alter its metabolism in response to different stimuli and forms of pressure. It helps cells resist external stress and provides them with new functions. Skin wound healing involves the metabolic reprogramming of nutrients, such as glucose, lipids, and amino acids, which play vital roles in the proliferation, differentiation, and migration of multiple cell types. During the glucose metabolic process in wounds, glucose transporters and key enzymes cause elevated metabolite levels. Glucose-mediated oxidative stress drives the proinflammatory response and promotes wound healing. Reprogramming lipid metabolism increases the number of fibroblasts and decreases the number of macrophages. It enhances local neovascularization and improves fibrin stability to promote extracellular matrix remodelling, accelerates wound healing, and reduces scar formation. Reprogramming amino acid metabolism affects wound re-epithelialization, collagen deposition, and angiogenesis. However, comprehensive reviews on the role of metabolic reprogramming in skin wound healing are lacking. Therefore, we have systematically reviewed the metabolic reprogramming of glucose, lipids, and amino acids during skin wound healing. Notably, we identified their targets with potential therapeutic value and elucidated their mechanisms of action.

The Effects of Statins, Ezetimibe, PCSK9-Inhibitors, Inclisiran, and Icosapent Ethyl on Platelet Function

This review aims to examine the complex interaction between dyslipidemia, platelet function, and related drug treatments. In particular, the manuscript provides an overview of the effects of major hypolipidemic drugs on platelet function. Indeed, growing evidence supports the view that statins, ezetimibe, PCSK9 inhibitors, inclisiran, and icosapent ethyl also act as antithrombotics. It is known that platelets play a key role not only in the acute phase of coronary syndromes but also in the early phase of atherosclerotic plaque formation. The goal of cholesterol-lowering therapy is to reduce cardiovascular events. The direct effects of cholesterol-lowering drugs are widely described in the literature. Lowering LDL-c (low-density lipoprotein cholesterol) by 1 mmol/L results in a 22-23% reduction in cardiovascular risk. Numerous studies have examined the direct antithrombotic effects of these drugs on platelets, endothelium, monocytes, and smooth muscle cells, and thus, potentially independent of blood LDL-cholesterol reduction. We reviewed in vitro and in vivo studies evaluating the complex interaction between hypercholesterolemia, hypertriglyceridemia, platelet function, and related drug treatments. First, we discussed the role of statins in modulating platelet activation. Discontinuation of statin therapy was associated with increased cardiovascular events with increased ox-LDL, P-selectin, and platelet aggregation. The effect of PCSK9-I (inhibitors of proprotein convertase subtilisin/kexin type 9, PCSK9 involved in the degradation of LDL receptors in the liver) was associated with a statistically significant reduction in platelet reactivity, calculated in P2Y12 reaction units (PRU), in the first 14 days and no difference at 30 days compared to placebo. Finally, in patients with hypertriglyceridemia, the REDUCE-IT study showed that icosapent ethyl (an ethyl ester of eicosapentaenoic acid that reduces triglyceride synthesis and improves triglyceride clearance) resulted in a 25% reduction in ischemic events and cardiovascular death. However, to date, there is not yet clear clinical evidence that the direct antithrombotic effects of the drugs may have a beneficial impact on outcomes independently from the reduction in LDL-C or triglycerides.

Myotubularin‐Related Protein14 Prevents Neointima Formation and Vascular Smooth Muscle Cell Proliferation by Inhibiting Polo‐Like Kinase1

Background

Restenosis is one of the main bottlenecks in restricting the further development of cardiovascular interventional therapy. New signaling molecules involved in the progress have continuously been discovered; however, the specific molecular mechanisms remain unclear. MTMR14 (myotubularin‐related protein 14) is a novel phosphoinositide phosphatase that has a variety of biological functions and is involved in diverse biological processes. However, the role of MTMR14 in vascular biology remains unclear. Herein, we addressed the role of MTMR14 in neointima formation and vascular smooth muscle cell (VSMC) proliferation after vessel injury.

Methods and Results

Vessel injury models were established using SMC‐specific conditional MTMR14‐knockout and ‐transgenic mice. Neointima formation was assessed by histopathological methods, and VSMC proliferation and migration were assessed using fluorescence ubiquitination‐based cell cycle indicator, transwell, and scratch wound assay. Neointima formation and the expression of MTMR14 was increased after injury. MTMR14 deficiency accelerated neointima formation and promoted VSMC proliferation after injury, whereas MTMR14 overexpression remarkably attenuated this process. Mechanistically, we demonstrated that MTMR14 suppressed the activation of PLK1 (polo‐like kinase 1) by interacting with it, which further leads to the inhibition of the activation of MEK/ERK/AKT (mitogen‐activated protein kinase kinase/extracellular‐signal‐regulated kinase/protein kinase B), thereby inhibiting the proliferation of VSMC from the medial to the intima and thus preventing neointima formation.

Conclusions

MTMR14 prevents neointima formation and VSMC proliferation by inhibiting PLK1. Our findings reveal that MTMR14 serves as an inhibitor of VSMC proliferation and establish a link between MTMR14 and PLK1 in regulating VSMC proliferation. MTMR14 may become a novel potential therapeutic target in the treatment of restenosis.

The Effect of Statin on Anemia in Patients with Chronic Kidney Disease and End-Stage Kidney Disease: A Systematic Review and Meta-Analysis

Although erythropoietin-stimulating agents are effective in treating anemia in patients with end-stage kidney disease (ESKD) undergoing hemodialysis, some ESKD patients, especially those with inflammation, continue to suffer from anemia. Statin, an inhibitor of hydroxymethylglutaryl-CoA (HMG-CoA) reductase with lipid-lowering effects, may have a pleiotropic effect in reducing inflammation, and thus increase hemoglobin (Hb) level. We searched the PubMed, Embase, and Cochrane databases for relevant studies. The population of interest comprised advanced chronic kidney disease (CKD) patients and ESKD patients receiving hemodialysis with statin treatment. The included study designs were randomized control trial/cohort study/pre-post observational study, and outcomes of interest were Hb, erythropoietin resistance index (ERI) and ferritin. PRISMA 2020 guidelines were followed, and risk of bias (RoB) was assessed using the RoB 2.0 tool in randomized controlled trials, and the Newcastle-Ottawa scale (NOS) in cohort studies. We eventually included ten studies (5258 participants), comprising three randomized controlled trials and seven cohort studies. Overall, Hb increased by 0.84 g/dL (95% confidence interval [CI]: −0.02 to 1.70) in all groups using statins, including single-arm cohorts, and by 0.72 g/dL (95% CI: −0.02 to 1.46) in studies with placebo control. Hb levels were higher in the study group than in the control group, with a mean difference of 0.18 g/dL (95% CI: 0.04–0.32) at baseline and 1.0 g/dL (95% CI: 0.13–1.87) at the endpoint. Ferritin increased by 9.97 ng/mL (95% CI: −5.36 to 25.29) in the study group and decreased by 34.01 ng/mL (95% CI: −148.16 to 80.14) in the control group; ferritin fluctuation was higher in the control group. In conclusion, statin may improve renal anemia in ESKD patients receiving hemodialysis and regular erythropoietin-stimulating agents. Future studies with more rigorous methodology and larger sample size study should be performed to confirm this beneficial effect.

Outcomes of patients with and without baseline lipid-lowering therapy undergoing revascularization for left main coronary artery disease: analysis from the EXCEL trial

OBJECTIVES

There is a paucity of data on the effect of baseline lipid-lowering therapy (LLT) in patients undergoing revascularization for left main (LM) coronary artery disease (CAD). We compared outcomes for patients with LMCAD randomized to percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) according to the presence of baseline LLT in the EXCEL trial.

PATIENTS AND METHODS

The EXCEL trial randomized 1905 patients with LMCAD and SYNTAX scores up to 32 to PCI with everolimus-eluting stents versus CABG. Patients were categorized according to whether they were medically treated with LLT at baseline, and their outcomes were examined using multivariable Cox proportional hazards regression. The primary endpoint was a composite of death, stroke, or myocardial infarction at 3 years.

RESULTS

Among 1901 patients with known baseline LLT status, 1331 (70.0%) were medically treated with LLT at baseline. There were no significant differences between the PCI and CABG groups in the 3-year rates of the primary endpoint in patients with versus without baseline LLT (Pinteraction=0.62). Among patients with baseline LLT, the 3-year rate of ischemia-driven revascularization was higher after PCI compared with CABG (13.7 vs. 5.3%; adjusted hazard ratio=2.97; 95% confidence interval: 1.95-4.55; P<0.0001), in contrast to patients without baseline LLT (9.8 vs. 12.1%; adjusted hazard ratio=0.79; 95% confidence interval: 0.47-1.33; P=0.39) (Pinteraction=0.0003).

CONCLUSION

In the EXCEL trial, 3-year major adverse event rates after PCI versus CABG for LMCAD were similar and consistent in patients with and without LLT at baseline; however, revascularization during follow-up was more common after PCI compared with CABG in patients with baseline LLT, but not in those without baseline LLT.

Monocyte-mediated drug delivery systems for the treatment of cardiovascular diseases

Major advances have been achieved in understanding the mechanisms and risk factors leading to cardiovascular disorders and consequently developing new therapies. A strong inflammatory response occurs with a substantial recruitment of innate immunity cells in atherosclerosis, myocardial infarction, and restenosis. Monocytes and macrophages are key players in the healing process that ensues following injury. In the inflamed arterial wall, monocytes, and monocyte-derived macrophages have specific functions in the initiation and resolution of inflammation, principally through phagocytosis, and the release of inflammatory cytokines and reactive oxygen species. In this review, we will focus on delivery systems, mainly nanoparticles, for modulating circulating monocytes/monocyte-derived macrophages. We review the different strategies of depletion or modulation of circulating monocytes and monocyte subtypes, using polymeric nanoparticles and liposomes for the therapy of myocardial infarction and restenosis. We will further discuss the strategies of exploiting circulating monocytes for biological targeting of nanocarrier-based drug delivery systems for therapeutic and diagnostic applications.

Secondary prevention after coronary artery bypass graft surgery: a primer

PURPOSE OF REVIEW

Despite the benefits of surgical coronary revascularization, patients continue to be at risk for ischemic events in the years that follow coronary artery bypass graft surgery (CABG), mandating the role for postoperative secondary preventive therapy. The purpose of this review was to present a summary on the subject of secondary prevention after CABG, including an overview of a recently published scientific statement, and highlight the newest studies in the field.

RECENT FINDINGS

Aspirin and statin therapy continue to be the mainstay of secondary prevention after CABG, although newer antiplatelet and lipid-lowering medicines are being actively studied for their potential benefits. Other important elements to secondary prevention after CABG include the aggressive management of hypertension, smoking cessation, and the initiation of cardiac rehabilitation.

SUMMARY

Secondary prevention is an essential component of postoperative care after CABG. Instituting preventive therapies after surgery optimizes graft patency and helps patients achieve the highest level of physical health and quality of life following CABG.

Calcification in original plaque and restenosis following carotid artery stenting

Background:

The relationship between calcification in primary plaque and recurrent stenosis after carotid artery stenting (CAS) is not established, but an inverse association with restenosis following carotid endarterectomy (CEA) has been suggested.

Methods:

We retrospectively analyzed 75 plaques of 109 consecutive CAS with regard to calcification, using the calcium score and shape, location, and other characteristics of original plaques together with stenting-related factors. CAS was performed in a standard fashion with an embolic protection device. Greater-than-moderate restenosis (≥50%) was assessed by peak systolic velocity (PSV) with duplex ultrasonography (≥130 cm/s, internal/common carotid or distal/proximal PSV ratio ≥2.0).

Results:

Univariate analysis revealed percentages of dyslipidemia treated with statins (P = 0.03), calcification in distal ICA (P = 0.02), and immediate residual stenosis (P = 0.02) were significantly higher in patients with greater-than-moderate restenosis, whereas calcification in carotid bulb and usage of open-cell stent were rather less frequent (P < 0.001 and P = 0.02, respectively). Multivariate logistic regression analysis showed that rarity of calcification in carotid bulb was a sole independent predictor for greater-than-moderate recurrent carotid stenosis 1 year after CAS (OR = 0.21, CI = 0.06–0.77, P = 0.02).

Conclusions:

Calcium score was not significantly related to restenosis at 1 year after CAS, as was previously found following CEA, though scarcity of calcification in carotid bulb was suggested as a predictor of in-stent restenosis. Compared to post-CEA restenosis, carotid plaque calcification may be inversely but tenuously associated with recurrent stenosis 1 year post-CAS. No other stenting factors (e.g., stent design, pre-/post-dilation, or protection devices) showed a significant association with recurrent stenosis post-CAS.

Restenosis after carotid artery stenting

As a common etiology for ischemic stroke, atherosclerotic carotid stenosis has been targeted by vascular surgery since 1950s. Compared with carotid endarterectomy, carotid angioplasty and stenting (CAS) is almost similarly efficacious and less invasive. These advantages make CAS an alternative in treating carotid stenosis. However, accumulative evidences suggested that the long-term benefit-risk ratio of CAS may be decreased or even neutralized by the complications related to in-stent restenosis (ISR). Therefore, investigating the mechanisms and identifying the influential factors of ISR are of vital importance for improving the long-term outcomes of CAS. As responses to intrinsic and extrinsic injuries, intimal hyperplasia and vascular smooth muscle cell proliferation have been regarded as the principle mechanisms for ISR development. Due to the lack of consensus-based definition and consistent follow-up protocol, the reported incidences of ISR after CAS varied widely among studies. These variations made the inter-study comparisons of ISR largely illogical. To eliminate restenosis after CAS, both surgery and endovascular procedures have been attempted with promising results. For preventing ISR, drug-eluting stents and antiplatelets have been proposed as potential solutions.

Vein graft failure: from pathophysiology to clinical outcomes

Occlusive arterial disease is a leading cause of morbidity and mortality worldwide. Aside from balloon angioplasty, bypass graft surgery is the most commonly performed revascularization technique for occlusive arterial disease. Coronary artery bypass graft surgery is performed in patients with left main coronary artery disease and three-vessel coronary disease, whereas peripheral artery bypass graft surgery is used to treat patients with late-stage peripheral artery occlusive disease. The great saphenous veins are commonly used conduits for surgical revascularization; however, they are associated with a high failure rate. Therefore, preservation of vein graft patency is essential for long-term surgical success. With the exception of 'no-touch' techniques and lipid-lowering and antiplatelet (aspirin) therapy, no intervention has hitherto unequivocally proven to be clinically effective in preventing vein graft failure. In this Review, we describe both preclinical and clinical studies evaluating the pathophysiology underlying vein graft failure, and the latest therapeutic options to improve patency for both coronary and peripheral grafts.

Impact of statin treatment on strut coverage after drug-eluting stent implantation

PURPOSE

To evaluate the effect of statin treatment on strut coverage after drug-eluting stent (DES) implantation.

MATERIALS AND METHODS

In this study, 60 patients were randomly assigned to undergo sirolimus-eluting stent (SES) or biolimus-eluting stent (BES) implantation, after which patients were randomly treated with pitavastatin 2 mg or pravastatin 20 mg for 6 months. The degree of strut coverage was assessed by 6-month follow-up optical coherence tomography, which was performed in 52 DES-implanted patients.

RESULTS

The percentages of uncovered struts were 19.4±14.7% in pitavastatin-treated patients (n=25) and 19.1±15.2% in pravastatin-treated patients (n=27; p=0.927). A lower percentage of uncovered struts was significantly correlated with a lower follow-up low-density lipoprotein (LDL) cholesterol level (r=0.486; p=0.009) and a greater decline of the LDL cholesterol level (r=-0.456; p=0.015) in SES-implanted patients, but not in BES-implanted patients. In SES-implanted patients, the percentage of uncovered struts was significantly lower among those with LDL cholesterol levels of less than 70 mg/dL after 6 months of follow-up (p=0.025), but no significant difference in this variable according to the follow-up LDL cholesterol level was noted among BES-implanted patients (p=0.971).

CONCLUSION

Lower follow-up LDL cholesterol levels, especially those less than 70 mg/dL, might have a protective effect against delayed strut coverage after DES implantation. This vascular healing effect of lower LDL cholesterol levels could differ according to the DES type.

Inhibition of neointimal hyperplasia in rats treated with atorvastatin after carotid artery injury may be mainly associated with down-regulation of survivin and Fas expression

CONTEXT

Atorvastatin is a member of the drug class known as statins, which is used for lowering blood cholesterol.

OBJECTIVE

The present study investigates the effect and mechanism of atorvastatin on neointimal hyperplasia after carotid artery injury (CAI) of rat.

MATERIALS AND METHODS

Fifty male rats were randomly divided into four groups: control group, sham-operated group, model group, and atorvastatin treatment group. The treatment group was fed with atorvastatin (10 mg/kg) with gastro-gavage at 5 p.m. every day for 28 d after surgery. The control group, model group, and sham-operated group were fed with the same volume of distilled water instead. The proliferations of intimal and medial layers were evaluated by hematoxylin & eosin (H&E) staining. The apoptosis of vascular smooth muscle cells (VSMCs) was determined by terminal deoxynucleotidyl transferased UTP nick end labeling (TUNEL) staining. Plasma concentrations of survivin and sFas were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Atorvastatin reduced neointimal formation and increased apoptosis of VSMCs in neointima. VSMCs apoptosis emerged at 3 d (8.42 ± 0.449 μm) and the intimal proliferation peaked by the end of 14 d (41.58 ± 1.64 μm). The plasma levels of survivin and sFas were gradually increased with the neointimal hyperplasia and increasingly decreased after atorvastatin treatment. The plasma levels of survivin and sFas in rats were elevated at 3 d (464.80 ± 105.27 pg/ml and 3256.00 ± 478.20 pg/ml, respectively), reached the peak of survivin at 14 d (1089.20 ± 232.32 pg/ml) and sFas at 7 d (4362.00 ± 639.92 pg/ml) and decreased at 28 d (562.00 ± 90.11 pg/ml and 2148.00 ± 257.14 pg/ml, respectively) in the model group. Compared with the model group, the atorvastatin treatment group has significantly less neointimal hyperplasia and more apoptosis of VSMCs.

CONCLUSIONS

Atorvastatin can inhibit neointimal hyperplasia and promote SMCs apoptosis in neointimal layers, which may be mainly associated with down-regulation of survivin and Fas expression after CAI of rat.

The effect of lowering LDL cholesterol on vascular access patency: post hoc analysis of the Study of Heart and Renal Protection

BACKGROUND AND OBJECTIVES

Reducing LDL cholesterol (LDL-C) with statin-based therapy reduces the risk of major atherosclerotic events among patients with CKD, including dialysis patients, but the effect of lowering LDL-C on vascular access patency is unclear.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Study of Heart and Renal Protection (SHARP) randomized patients with CKD to 20 mg simvastatin plus 10 mg ezetimibe daily versus matching placebo. This study aimed to explore the effects of treatment on vascular access occlusive events, defined as any access revision procedure, access thrombosis, removal of an old dialysis access, or formation of new permanent dialysis access.

RESULTS

Among 2353 SHARP participants who had functioning vascular access at randomization, allocation to simvastatin plus ezetimibe resulted in a 13% proportional reduction in vascular access occlusive events (355 [29.7%] for simvastatin/ezetimibe versus 388 [33.5%] for placebo; risk ratio [RR], 0.87; 95% confidence interval [95% CI], 0.75 to 1.00; P=0.05). There was no evidence that the effects of treatment differed for any of the separate components of this outcome. To test the hypothesis raised by SHARP, comparable analyses were performed using the AURORA (A Study to Evaluate the Use of Rosuvastatin in Subjects on Regular Hemodialysis: An Assessment of Survival and Cardiovascular Events) trial cohort. AURORA did not provide independent confirmation (vascular access occlusive events: 352 [28.9%] for rosuvastatin versus 337 [27.6%] for placebo; RR, 1.06, 95% CI, 0.91 to 1.23; P=0.44). After combining the two trials, the overall effect of reducing LDL-C with a statin-based regimen on vascular access occlusive events was not statistically significant (707 [29.3%] with any LDL-C-lowering therapy versus 725 [30.5%] with placebo; RR, 0.95, 95% CI, 0.85 to 1.05; P=0.29).

CONCLUSIONS

Exploratory analyses from SHARP suggest that lowering LDL-C with statin-based therapy may improve vascular access patency, but there was no evidence of benefit in AURORA. Taken together, the available evidence suggests that any benefits of lowering LDL-C on vascular access patency are likely to be modest.

Low-density lipoprotein-cholesterol-induced endothelial dysfunction and oxidative stress: the role of statins

SIGNIFICANCE

Cardiovascular diseases (CVD) represent a major public health burden. High low-density lipoprotein (LDL)-cholesterol is a recognized pathogenic factor for atherosclerosis, and its complications and statins represent the most potent and widely used therapeutic approach to prevent and control these disorders.

RECENT ADVANCES

A number of clinical and experimental studies concur to identify endothelial dysfunction as a primary step in the development of atherosclerosis, as well as a risk factor for subsequent clinical events. Oxidant stress resulting from chronic elevation of plasma LDL-cholesterol (LDL-chol) is a major contributor to both endothelial dysfunction and its complications, for example, through alterations of endothelial nitric oxide signaling.

CRITICAL ISSUES

Statin treatment reduces morbidity and mortality of CVD, but increasing evidence questions that this is exclusively through reduction of plasma LDL-chol. The identification of ancillary effects on (cardio)vascular biology, for example, through their modulation of oxidative stress, will not only increase our understanding of their mechanisms of action, with a potential broadening of their indication(s), but also lead to the identification of new molecular targets for future therapeutic developments in CVD.

FUTURE DIRECTIONS

Further characterization of molecular pathways targeted by statins, for example, not directly mediated by changes in plasma lipid concentrations, should enable a more comprehensive approach to the pathogenesis of (cardio)vascular disease, including, for example, epigenetic regulation and fine tuning of cell metabolism.

Use of statins in lower extremity artery disease: a review

Background

Lower extremity artery disease (LE-PAD) is one of the most common manifestations of atherosclerosis, particularly in elderly patients, and it is related to a high cardiovascular risk.

Description

It is well established that statin therapy is characterized by crucial benefits on cardiovascular system by limiting atherosclerotic progression and reducing cardiovascular events and mortality. A growing body of evidence support efficacy of statins in LE-PAD due to the ability of both reducing cardiovascular risk and improving walking distance and, hence, quality of life. Consequently, statin therapy should be considered in all LE-PAD patients and new LDL-cholesterol targets should be reached.

Conclusions

Our opinion is that statin therapy remains still underutilized or with inadequate dosage, so therapy of LE-PAD patients should be improved to obtain all the demonstrated benefits of statins.

Bioactive coatings for coronary stents: Modulation of cell proliferation by controlled release of anti-proliferative drugs

Drug eluting coronary stents coated with a bioactive and biostable polymer system (THBA70), based on acrylate copolymers bearing a salicylic acid derivative as side substituent, were evaluated. The microstructural architecture of the copolymer THBA70 comprises a random copolymer of a methacrylate derivative from triflusal (4-trifluoromethyl salicylic acid) with 45 mol% of THEMA (2-methacryloyloxyethyl [2-(acetyloxy)-4-(trifluoromethyl)] benzoate), which makes the system anti-thrombogenic with good adhesion to the surface of metallic stents. The bioactive coating prevented thrombosis, an adverse effect associated with the implantation of drug-eluting stents. The in vitro drug delivery of drug-eluting stents under dynamic conditions indicated excellent controlled drug release. The THBA70 films loaded with relatively low concentrations of taxol or simvastatin in contact with fibroblasts produced inhibition of cell proliferation with a dose-dependent bioactivity.

Bindarit inhibits human coronary artery smooth muscle cell proliferation, migration and phenotypic switching

Bindarit, a selective inhibitor of monocyte chemotactic proteins (MCPs) synthesis, reduces neointimal formation in animal models of vascular injury and recently has been shown to inhibit in-stent late loss in a placebo-controlled phase II clinical trial. However, the mechanisms underlying the efficacy of bindarit in controlling neointimal formation/restenosis have not been fully elucidated. Therefore, we investigated the effect of bindarit on human coronary smooth muscle cells activation, drawing attention to the phenotypic modulation process, focusing on contractile proteins expression as well as proliferation and migration. The expression of contractile proteins was evaluated by western blot analysis on cultured human coronary smooth muscle cells stimulated with TNF-α (30 ng/mL) or fetal bovine serum (5%). Bindarit (100-300 µM) reduced the embryonic form of smooth muscle myosin heavy chain while increased smooth muscle α-actin and calponin in both TNF-α- and fetal bovine serum-stimulated cells. These effects were associated with the inhibition of human coronary smooth muscle cell proliferation/migration and both MCP-1 and MCP-3 production. The effect of bindarit on smooth muscle cells phenotypic switching was confirmed in vivo in the rat balloon angioplasty model. Bindarit (200 mg/Kg/day) significantly reduced the expression of the embryonic form of smooth muscle myosin heavy chain, and increased smooth muscle α-actin and calponin in the rat carodid arteries subjected to endothelial denudation. Our results demonstrate that bindarit induces the differentiated state of human coronary smooth muscle cells, suggesting a novel underlying mechanisms by which this drug inhibits neointimal formation.

Pitavastatin-incorporated nanoparticle-eluting stents attenuate in-stent stenosis without delayed endothelial healing effects in a porcine coronary artery model

AIM

The use of currently marketed drug-eluting stents presents safety concerns including increased late thrombosis, which is thought to result mainly from delayed endothelial healing effects (impaired re-endothelialization resulting in abnormal inflammation and fibrin deposition). We recently developed a bioabsorbable polymeric nanoparticle (NP)-eluting stent using a novel cationic electrodeposition technology. Statins are known to inhibit the proliferation of vascular smooth muscle cells (VSMC) and to promote vascular healing. We therefore hypothesized that statin-incorporated NP-eluting stents would attenuate in-stent stenosis without delayed endothelial healing effects.

METHODS

Among six marketed statins, pitavastatin (Pitava) was found to have the most potent effects on VSMC proliferation and endothelial regeneration in vitro. We thus formulated a Pitava-NP-eluting stent (20µg Pitava per stent).

RESULTS

In a pig coronary artery model, Pitava-NP-eluting stents attenuated in-stent stenosis as effectively as polymer-coated sirolimus-eluting stents (SES). At SES sites, delayed endothelial healing effects were noted, whereas no such effects were observed in Pitava-NP-eluting stent sites.

CONCLUSION

Pitava-NP-eluting stents attenuated in-stent stenosis as effectively as SES without the delayed endothelial healing effects of SES in a porcine coronary artery model. This nanotechnology platform could be developed into a safer and more effective device in the future.

Simvastatin attenuated cerebrovascular cell proliferation in the development of hypertension through Rho/Rho-kinase pathway

The cerebrovascular remodeling is a prominent feature of hypertension and considered as a major risk of stroke. Statins may suppress the activation of the Rho/Rho-kinase pathway and have pleiotropic actions against the development of vascular remodeling. We hypothesized that the inhibition of the Rho/Rho-kinase pathway by simvastatin during hypertension could recuperate the pathological changes of basilar artery through the downregulation of cell proliferation. To resolve the problem, we used 2-kid, 2-clip rat as a hypertension model and evaluated the effect of simvastatin on the Rho/Rho-kinase pathway. In addition, we assessed the changes of the proliferation rate by CCK-8 assay in basilar artery smooth muscle cells. Our results from this study showed that a continuous increase in the plasma endothelin-1 (ET-1) concentration and the Rho/Rho-kinase activity was positively correlated with changes in blood pressure in the hypertensive rat. Simvastatin ameliorated the upregulated Rho/Rho-kinase activity and cell proliferation during hypertension. Moreover, simvastatin, the RhoA inhibitor C3, and the RhoA-kinase inhibitor Y27632 all attenuated the proliferation rate induced by ET-1 in basilar artery smooth muscle cells via the Rho/Rho-kinase signaling pathway. In conclusion, simvastatin attenuated ET-1-induced proliferation through the Rho/Rho-kinase signaling pathway in hypertensive rat basilar artery, and it may be an excellent reagent to protect vascular remodeling and stroke.

Impact of statin therapy on late target lesion revascularization after sirolimus-eluting stent implantation (from the CREDO-Kyoto Registry Cohort-2)

Therapeutic strategies preventing late target lesion revascularization (TLR) after drug-eluting stent implantation have not been yet adequately investigated. In 13,087 consecutive patients undergoing first percutaneous coronary intervention in the CREDO-Kyoto Registry Cohort-2, we identified 10,221 patients who were discharged alive after implantation of sirolimus-eluting stents (SESs) only (SES stratum 5,029) or bare-metal stents (BMSs) only (BMS stratum 5,192). Impact of statin therapy at time of discharge from the index hospitalization on early (within the first year) and late (1 year to 4 years) TLR, was assessed in the SES stratum (statin group 2,735; nonstatin group 2,294) and in the BMS stratum (statin group 2,576; nonstatin group 2,616). Despite a significantly lower incidence of early TLR (7.8% vs 22.2%, p <0.0001), SES use compared to BMS use was associated with a significantly higher incidence of late TLR (7.7% vs 3.0%, p <0.0001). In the SES and BMS strata, the incidence of early TLR was similar regardless of statin use. In the SES stratum, the incidence of late TLR was significantly lower in the statin group than in the nonstatin group (6.1% vs 9.6%, p = 0.002), whereas no significant difference was found in the BMS stratum (2.6% vs 3.3%, p = 0.38). After adjusting confounders, risk for late TLR significantly favored statin use in the SES stratum (hazard ratio 0.73, 95% confidence interval 0.54 to 0.98, p = 0.04), whereas the risk decrease was not significant in the BMS stratum (hazard ratio 0.74, 95% confidence interval 0.46 to 1.20, p = 0.23). In conclusion, statin therapy at hospital discharge was associated with a significantly lower risk for late TLR after SES implantation.

Lipid-lowering therapy and coronary artery bypass graft surgery: what are the benefits?

PURPOSE OF REVIEW

Despite their apparent benefits, statins remain underutilized after coronary artery bypass graft (CABG) surgery. To summarize the literature regarding statin therapy and CABG, we performed a systematic review of the Medline database from 1987-2011 to assess the benefits of statins in CABG patients, including the role of high-dose therapy, and highlight areas for future study.

RECENT FINDINGS

When administered prior to CABG, statins reduce the risk of perioperative mortality, stroke, and atrial fibrillation. After CABG, statins limit the progression of atherosclerosis in native coronary arteries, inhibit the process of saphenous vein graft disease, and improve vein graft patency. Furthermore, postoperative statins reduce the recurrence of cardiovascular events and improve all-cause mortality. High-intensity statin therapy early after surgery may benefit CABG patients, but this is yet to be evaluated prospectively.

SUMMARY

Statins clearly improve the outcomes of CABG patients. In the absence of contraindications, all patients undergoing CABG are candidates for life-long statin therapy, with initiation recommended as soon as coronary disease is documented. Statins should be restarted early after surgery. However, the optimal postoperative lipid-lowering regimen remains unknown and should be the subject of upcoming trials. Strategies directed toward improving statin prescription rates and patient adherence should also be priorities for future research.

Contrast-induced nephropathy: do statins offer protection?

PURPOSE OF REVIEW

Contrast-induced nephropathy (CIN) is a commonly occurring complication associated with the use of contrast media in radiological studies. Various clinical studies have been reported investigating the nephroprotective role of statins. In this article, we review relevant clinical studies reported in 2010.

RECENT FINDINGS

An overview of these indicates that the evidence for the use of statins specifically for offering renal protection against CIN is conflicting and inconclusive.

SUMMARY

Pending large, well designed, adequately powered randomized controlled trials, it can be concluded that at present there is no definite evidence for their use in preventing CIN apart from their antiatherosclerotic use. However, using the analogy of beneficial effect of statin preloading with percutaneous coronary intervention, it can be speculated that high-dose statin may be beneficial in affording nephroprotection against CIN.

Simvastatin exerts favourable effects on neointimal formation in a mouse model of vein graft

BACKGROUND

Simvastatin inhibits human saphenous vein neointima formation in human saphenous vein organ cultures. However, it is not known if simvastatin actually inhibits vein graft intima hyperplasia in vivo, and the underlying mechanisms behind that. In this study, we used a murine vein graft model to address these issues.

METHODS AND RESULTS

Vein grafting was performed among C57BL/6 J mice treated with low-dose (2 mg kg(-1)) or high-dose (20 mg kg(-1)) simvastatin or vehicle subcutaneously 72 h before and then daily after surgery. As compared to the vehicle, simvastatin dose-dependently significantly inhibited vein graft intima hyperplasia 4 weeks after surgeries. Immunohistochemistry studies suggested that vein graft neointima was mainly composed of vascular smooth muscle cells (VSMCs), and the rate of proliferating cell nuclear antigen (PCNA)-positive cells in the intima of vein grafts was significantly lower in simvastatin-treated groups than in control group. We isolated VSMC from mouse vena cava, simvastatin significantly reduced VSMC proliferation, and platelet-derived growth factor (PDGF)-induced VSMC migration in a dose-dependent manner.

CONCLUSION

Simvastatin inhibits neointima formation of mouse vein graft under normocholesterolaemic condition in vivo, the mechanisms might be associated with inhibitory effects of simvastatin on VSMC proliferation and migration.

Is a regenerative approach viable for the treatment of COPD?

Degenerative lung diseases such as chronic obstructive pulmonary disease (COPD) are common with huge worldwide morbidity. Anti-inflammatory drug development strategies have proved disappointing and current treatment is aimed at symptomatic relief. Only lung transplantation with all its attendant difficulties offers hope of cure and the outlook for affected patients is bleak. Lung regeneration therapies aim to reverse the structural and functional deficits in COPD either by delivery of exogenous lung cells to replace lost tissue, delivery of exogenous stem cells to induce a local paracrine effect probably through an anti-inflammatory action or by the administration of small molecules to stimulate the endogenous regenerative ability of lung cells. In animal models of emphysema and disrupted alveolar development each of these strategies has shown some success but there are potential tumour-inducing dangers with a cellular approach. Small molecules such as all-trans retinoic acid have been successful in animal models although the mechanism is not completely understood. There are currently two Pharma-sponsored trials in progress concerning patients with COPD, one of a specific retinoic acid receptor gamma agonist and another using mesenchymal stem cells.

Statin use is associated with lower inflammation and erythropoietin responsiveness index in hemodialysis patients

Patients with end-stage renal disease are prone to inflammation and inflammation is related to erythropoietin-stimulating agent hyporesponsiveness and mortality in this population. Statins have been demonstrated to reduce cardiovascular mortality in selected populations of end-stage renal disease patients. These drugs have pleiotrophic effects such as anti-inflammation. In this retrospective analysis, we determined whether the use of statins improves inflammation and inflammation-related anemia in a cohort of hemodialysis patients. Data were analyzed from Fresenius Medical Care Dialysis Clinics in Turkey between 2005 and 2007. Seventy prevalent hemodialysis patients who were on statins at the start of the study and have been on statins during follow-up (statin users) and 1293 patients who were not on statin at the start of the study and had never been prescribed any lipid-modifying drugs during follow-up (statin nonusers) were included in the study. High-sensitive C-reactive protein levels were significantly decreased in statin users (1.50±1.49 vs. 1.33±1.11 mg/L, P=0.05) compared with nonusers (1.93±3.22 vs. 2.05±2.77 mg/L). Hemoglobin levels and the rate of erythropoietin-stimulating agent users were similar. However, the prescribed erythropoietin-stimulating agent dose (31.6±27.5 vs. 47.3±45.2 U/kg/week, P<0.05) and the erythropoietin response index (2.90±2.73 vs. 4.51±4.48 U/kg/week/Hb, P=0.001) were lower in statin users compared with statin nonusers. On stepwise multiple regression analysis, gender, high-sensitive C-reactive protein, duration of hemodialysis, serum ferritin, and statin use were independent determinants of the erythropoietin responsiveness index. Our results suggest that statin treatment leads to lower inflammation and improves hematopoiesis in hemodialysis patients.

Effects of atorvastatin and losartan on monocrotaline-induced pulmonary artery remodeling in rats

Structural remodeling of pulmonary artery plays an important role in maintaining sustained pulmonary arterial hypertension (PAH). The anti-remodeling effects of statins have been reported in systemic hypertension. In this study, we studied the effects of atovastatin (Ato) or losartan (Los) in monocrotaline (MCL)-induced pulmonary artery remodeling using a rat model. Forty Sprague-Dawley (SD) rats were randomly assigned into four groups (n = 10): normal control (Ctr), PAH, PAH treated with Los, and PAH treated with Ato. We found that in the Los- or Ato-treated group, the mean pulmonary arterial pressure, right heart hypertrophy index, ratio of wall/lumen thickness (WT%), as well as the wall/lumen area (WA%) were significantly reduced compared to the PAH group. Also in pulmonary arteries dissected from rats in the Ato- or Los-treated group, in both mRNA and protein levels, the expression of α1C subunit of voltage-gated calcium channel (Ca(v)α1c) was downregulated, while sarcoplasmic/endoplasmic reticulum calcium-ATPase (SERCA-2a) and inositol 1,4,5 triphosphate receptor 1 (IP3R-1) upregulated. However, the mRNA level of RyR-3 subunit of calcium regulating channel was increased, whereas its protein level was reduced in the treated groups. Our results suggest that atorvastatin or losartan may regress the remodeling of the pulmonary artery in pulmonary hypertensive rats, with differential expression of calcium regulating channels.

Effects of combined therapy with ezetimibe plus simvastatin after drug-eluting stent implantation in a porcine coronary restenosis model

The aim of this study was to examine the anti-proliferative and anti-inflammatory effects of ezetimibe/simvastatin (E/S) after drug-eluting stent (DES) implantation in a porcine coronary restenosis model. Pigs were randomized into two groups in which the coronary arteries (23 pigs) had DES. Stents were deployed with oversizing (stent/artery ratio 1.3:1) in porcine coronary arteries. Fifteen pigs were taken 10/20 mg of E/S and eight pigs were not taken E/S. Histopathologic analysis was assessed at 28 days after stenting. In neointima, most inflammatory cells were lymphohistiocytes. Lymphohistiocyte count was not different between two groups (337+/-227 vs. 443+/-366 cells, P=0.292), but neointima area was significantly smaller (1.00+/-0.49 mm(2) vs. 1.69+/-0.98 mm(2), P=0.021) and percent area stenosis was significantly lower (23.3+/-10% vs. 39+/-19%, P=0.007) in E/S group compared with control group. There were no significant differences in fibrin score (1.99+/-0.79 vs. 1.81+/-0.88, P=0.49), endothelial score (1.75+/-0.66 vs. 1.80+/-0.59, P=0.79), and the percent of endothelium covered lumen (43+/-21% vs. 45+/-21%, P=0.84) between E/S group and control group. Combined therapy with ezetimibe and simvastatin inhibits neointimal hyperplasia, but does not inhibit inflammatory infiltration and arterial healing after DES implantation in a porcine coronary restenosis model.

Liposomal simvastatin attenuates neointimal hyperplasia in rats

Monocytes, macrophages, and inflammation play a key role in the process of neointimal proliferation and restenosis. The present study evaluated whether systemic and transient depletion of monocytes could be obtained by a single intravenous (IV) injection of simvastatin liposomes, for the inhibition of neointima formation. Balloon-injured carotid artery rats (n = 30) were randomly assigned to treatment groups of free simvastatin, simvastatin in liposomes (3 mg/kg), and saline (control). Stenosis and neointima to media ratio (N/M) were determined 14 days following single IV injection at the time of injury by morphometric analysis. Depletion of circulating monocytes was determined by flow cytometry analyzes of blood specimens. Inhibition of RAW264.7, J774, and THP-1 proliferation by simvastatin-loaded liposomes and free simvastatin was determined by the 3-(4, 5-dimethylthiazolyl-2)-2, 5- diphenyltetrazolium bromide assay. Simvastatin liposomes were successfully formulated and were found to be 1.5-2 times more potent than the free drug in suppressing the proliferation of monocytes/macrophages in cell cultures of RAW 264.7, J774, and THP-1. IV injection of liposomal simvastatin to carotid-injured rats (3 mg/kg, n = 4) resulted in a transient depletion of circulating monocytes, significantly more prolonged than that observed following treatment with free simvastatin. Administration to balloon-injured rats suppressed neointimal growth. N/M at 14 days was 1.56 +/- 0.16 and 0.90 +/- 0.12, control and simvastatin liposomes, respectively. One single systemic administration of liposomal simvastatin at the time of injury significantly suppresses neointimal formation in the rat model of restenosis, mediated via a partial and transient depletion of circulating monocytes.

Simvastatin restores down-regulated GATA-6 expression in pulmonary hypertensive rats

Vascular smooth muscle cell proliferation has been known to be predominant in vascular remodeling of pulmonary hypertensive. The GATA family proteins, a group of zinc finger transcription factors, play an important role during cell proliferation. The aim of present study was to investigate the expression of GATA-6 gene in experimental pulmonary hypertensive rats and explore the effect of regulation of GATA-6 expression by simvastatin on pulmonary vascular remodeling. The male Sprague-Dawley rats model was established with receiving pneumonectomy and monocrotaline (MCT) administration. Right pulmonary artery remodeling in these animals was compared with untreated rats or rats receiving simvastatin. The level of GATA-6 mRNA and protein expression was detected by reverse transcriptase–polymerase chain reaction (RT-PCR) and Western blotting, respectively. Pneumonectomized, MCT-treated rats had significantly increased mean pulmonary arterial pressure (mPAP), RV/(LV + S) ratio (ratio of the right ventricular to left ventricular and septum weights), vascular occlusion scores (VOSs), and percent media wall thickness on day 35, all the indices were significantly decreased after simvastatin administration in these rats. The level of GATA-6 mRNA and protein were markedly decreased in these pneumonectomy and MCT-treated rats, and they were significantly up-regulated in these rats after receiving simvastatin. These results indicate that the development and progression of pulmonary hypertension is prevented by simvastatin by up-regulating GATA-6 expression in the lung tissue.

Effects of Atorvastatin on Vascular Intimal Hyperplasia: An Experimental Rodent Model

Introduction Vascular intimal hyperplasia is associated with increased mortality and morbidity. The authors investigated the effects of atorvastatin on vascular intimal hyperplasia. Materials and methods Rats were divided into 4 groups. Groups 1, 2, and 3 had experimental aortic injury and received intraperitoneal injection of atorvastatin, solvent, or 0.9% NaCl, respectively. Group 4 was a nonintervention (laparotomy only) control group. Animals were sacrificed after 3 weeks. Blood samples and injured aortic segment were analyzed. Results Atorvastatin administration significantly lowered total and low-density lipoprotein cholesterol levels ( P = .012 and P = .001, respectively), intima—media ratio ( P = .002), and intimal smooth muscle cell accumulation ( P < .05) in group 1. Luminal narrowing in animals in group 1 was significantly lower than that in animals in groups 2 and 3, but was higher than in animals in group 4 ( P = .009). Conclusions Atorvastatin suppresses intimal hyerplasia and aids in intimal regeneration by lowering blood lipids and intimal smooth muscle cell accumulation.

Local delivery of gene vectors from bare-metal stents by use of a biodegradable synthetic complex inhibits in-stent restenosis in rat carotid arteries

BACKGROUND

Local drug delivery from polymer-coated stents has demonstrated efficacy for preventing in-stent restenosis; however, both the inflammatory effects of polymer coatings and concerns about late outcomes of drug-eluting stent use indicate the need to investigate innovative approaches, such as combining localized gene therapy with stent angioplasty. Thus, we investigated the hypothesis that adenoviral vectors (Ad) could be delivered from the bare-metal surfaces of stents with a synthetic complex for reversible vector binding.

METHODS AND RESULTS

We synthesized the 3 components of a gene vector binding complex: (1) A polyallylamine bisphosphonate with latent thiol groups (PABT), (2) a polyethyleneimine (PEI) with pyridyldithio groups for amplification of attachment sites [PEI(PDT)], and (3) a bifunctional (amine- and thiol-reactive) cross-linker with a labile ester bond (HL). HL-modified Ad attached to PABT/PEI(PDT)-treated steel surfaces demonstrated both sustained release in vitro over 30 days and localized green fluorescent protein expression in rat arterial smooth muscle cell cultures, which were not sensitive to either inhibition by neutralizing anti-Ad antibodies or inactivation after storage at 37 degrees C. In rat carotid studies, deployment of steel stents configured with PABT/PEI(PDT)/HL-tethered adenoviral vectors demonstrated both site-specific arterial Ad(GFP) expression and adenovirus-luciferase transgene activity per optical imaging. Rat carotid stent delivery of adenovirus encoding inducible nitric oxide synthase resulted in significant inhibition of restenosis.

CONCLUSIONS

Reversible immobilization of adenovirus vectors on the bare-metal surfaces of endovascular stents via a synthetic complex represents an efficient, tunable method for sustained release of gene vectors to the vasculature.