Inhibition of the mevalonate pathway: benefits beyond cholesterol reduction?

The Impact of Statins before High-Risk CABG on Postoperative Multiple Organ Function

Background

The purpose of this cohort study was to investigate the independent relationship between preoperative statin therapy (PST) and postoperative severe multiorgan failure, measured by the Sequential Organ Failure Assessment (SOFA) maximum greater than 11, in high-risk patients undergoing isolated coronary artery bypass grafting (CABG).

Methods

The present study is a perspective, single-center, cohort analysis enrolling high-risk patients undergoing CABG from Jan 1, 2018, to Dec 31, 2018, in Beijing Anzhen hospital.

Results

Among a total of 880 high-risk patients undergoing isolated CABG included in this study, 503 (57.2%) experienced statin therapy before CABG. The SOFA maximum was significantly lower in the PST group compared with the control group (7.8 ± 3.0 v 9.2 ± 3.4, P < 0.0001). Multivariate logistic regression analysis demonstrated the incidence of the severe multiorgan dysfunction, measured by SOFA maximum ≥11, was dramatically reduced in the PST group (OR, 0.68, 95% CI 0.50-0.92, P=0.013). Furthermore, preoperative statin therapy (PST) might be associated with a decreased risk of postoperative major adverse cardiovascular and cerebral events and acute kidney injury, but an increased risk of postoperative hepatic inadequacy.

Conclusion

SOFA maximum was significantly lower in the PST group compared with the control group and the incidence of the severe multiorgan dysfunction was dramatically reduced in the PST group. The findings of this study might shed new light on questions of positive or negative effects of PST on multiple organ function after high-risk CABG, so as to ultimately improve high-risk patient in-hospital outcomes from CABG.

Significant effect of simvastatin and/or ezetimibe-loaded nanofibers on the healing of femoral defect: An experimental study

BACKGROUND

Fracture healing complications are associated with significant healthcare and economic burden. In this study, we aimed to investigate how the combined administration of local simvastatin and ezetimibe into the femoral defect of the animal model affects the bone-healing process in comparison with their monotherapy.

METHODS

A total of 32 four-month-old adult male Wistar rats were randomized into the four study groups: simvastatin + ezetimibe-loaded nanofibers (group 1), simvastatin-loaded nanofibers (group 2), ezetimibe-loaded nanofibers (group 3), and non-loaded nanofibers (group 4). After the generation of femoral defects, the predesigned nanofibers were locally administered into the defect site. The healing measures were serum and bone osteoprotegerin (OPG) expression, pathologic evaluation of union (Allen's fracture healing scores), and radiographic evaluation of bone density (Hounsfield scale) at weeks 2 and 4.

RESULTS

The improvement of all evaluated healing measures was remarkably superior in rats that were treated with loaded nanofibers in comparison with the control group. Also, the improvement of all evaluated healing measures was considerably more in the simvastatin-ezetimibe combination therapy group compared to their monotherapy. All the evaluated measures were superior in the ezetimibe monotherapy group compared to the simvastatin monotherapy group.

CONCLUSION

The cumulative effect of simvastatin and ezetimibe on the induction of bone healing is more significant than the individual effect of these drugs. Therefore, local administration of nanofibers loaded with simvastatin and ezetimibe could be regarded as a promising osteoinductive compound for the acceleration of bone repair.

Metabolic engineering of Escherichia coli for the production of isoprenoids

Metabolic engineering is the practice of using directed genetic manipulations to rewire cellular metabolism primarily with the aim to transform the organism into a single-celled chemical factory. Using biological processes, we can produce more complex chemicals in a more sustainable way. This is particularly important for chemicals which are hard to synthesize using traditional chemistry. However, cells have evolved for growth and must be engineered to produce a single chemical at commercially viable levels. This review focuses on the strategies used to rewire cellular metabolism to produce chemicals using isoprenoid production in Escherichia coli as an example that illustrates many of the challenges faced in metabolic engineering.

Lack of Association between Preoperative Statin Use and Respiratory and Neurologic Complications after Cardiac Surgery

Background

Statins may reduce the risk of pulmonary and neurologic complications after cardiac surgery.

Methods

The authors acquired data for adults who had coronary artery bypass graft, valve surgery, or combined procedures. The authors matched patients who took statins preoperatively to patients who did not. First, the authors assessed the association between preoperative statin use and the primary outcomes of prolonged ventilation (more than 24 h), pneumonia (positive cultures of sputum, transtracheal fluid, bronchial washings, and/or clinical findings consistent with the diagnosis of pneumonia), and in-hospital all-cause mortality, using logistic regressions. Second, the authors analyzed the collapsed composite of neurologic complications using logistic regression. Intensive care unit and hospital length of stay were evaluated with Cox proportional hazard models.

Results

Among 14,129 eligible patients, 6,642 patients were successfully matched. There was no significant association between preoperative statin use and prolonged ventilation (statin: 408/3,321 [12.3%] vs. nonstatin: 389/3,321 [11.7%]), pneumonia (44/3,321 [1.3%] vs. 54/3,321 [1.6%]), and in-hospital mortality (52/3,321 [1.6%] vs. 43/3,321 [1.3%]). The estimated odds ratio was 1.06 (98.3% CI, 0.88 to 1.27) for prolonged ventilation, 0.81 (0.50 to 1.32) for pneumonia, and 1.21 (0.74 to 1.99) for in-hospital mortality. Neurologic outcomes were not associated with preoperative statin use (53/3,321 [1.6%] vs. 56/3,321 [1.7%]), with an odds ratio of 0.95 (0.60 to 1.50). The length of intensive care unit and hospital stay was also not associated with preoperative statin use, with a hazard ratio of 1.04 (0.98 to 1.10) for length of hospital stay and 1.00 (0.94 to 1.06) for length of intensive care unit stay.

Conclusions

Preoperative statin use did not reduce pulmonary or neurologic complications after cardiac surgery.

The administration of drugs inhibiting cholesterol/oxysterol synthesis is safe and increases the efficacy of immunotherapeutic regimens in tumor-bearing mice

Tumor-derived metabolites dampen tumor-infiltrating immune cells and antitumor immune responses. Among the various metabolites produced by tumors, we recently showed that cholesterol oxidized products, namely oxysterols, favor tumor growth through the inhibition of DC migration toward lymphoid organs and by promoting the recruitment of pro-tumor neutrophils within the tumor microenvironment. Here, we tested different drugs capable of blocking cholesterol/oxysterol formation. In particular, we tested efficacy and safety of different administration schedules, and of immunotherapy-based combination of a class of compounds, namely zaragozic acids, which inhibit cholesterol pathway downstream of mevalonate formation, thus leaving intact the formation of the isoprenoids, which are required for the maturation of proteins involved in the immune cell function. We show that zaragozic acids inhibit the in vivo growth of the RMA lymphoma and the Lewis lung carcinoma (LLC) without inducing side effects. Tumor growth inhibition requires an intact immune system, as immunodeficient tumor-bearing mice do not respond to zaragozic acid treatment. Of note, the effect of zaragozic acids is accompanied by a marked reduction in the LXR target genes Abcg1, Mertk, Scd1 and Srebp-1c in the tumor microenvironment. On the other hand, zoledronate, which blocks also isoprenoid formation, did not control the LLC tumor growth. Finally, we show that zaragozic acids potentiate the antitumor effects of active and adoptive immunotherapy, significantly prolonging the overall survival of tumor-bearing mice treated with the combo zaragozic acids and TAA-loaded DCs. This study identifies zaragozic acids as new antitumor compounds exploitable for the treatment of cancer patients.

Lovastatin exerts protective effects on endothelial cells via upregulation of PTK2B

Statins are HMG-CoA reductase inhibitors that are used to decrease the blood levels of low-density lipoprotein (LDL). In addition, they have been shown to exert pleiotropic protective effects in the absence of LDL-lowering activity. The present study investigated the effects of lovastatin on global gene expression in human umbilical vein endothelial cells (HUVECs), in order to further explore its ability to protect against oxidized (ox)-LDL-induced cytotoxicity. HUVECs were treated with lovastatin for 2–24 h, and gene expression patterns were analyzed using cDNA microarrays. The results suggested that numerous genes were regulated by lovastatin, including certain genes associated with cell survival, such as PTK2B, BCL2 and MAP3K3. In particular, PTK2B, which has been shown to exert anti-apoptotic effects against ox-LDL-induced cell injury, was upregulated by lovastatin. Knockdown of PTK2B was able to attenuate ox-LDL-induced cell injury, and this was associated with decreased levels of phosphorylated-AKT and eNOS, and inhibition of mitochondrial-dependent apoptosis. In conclusion, the results of the present study suggested that lovastatin protects against ox-LDL-induced cell injury, potentially via the upregulation of PTK2B, which regulates the anti-apoptosis signaling pathway.

Abrogating cholesterol esterification suppresses growth and metastasis of pancreatic cancer

Cancer cells are known to execute reprogramed metabolism of glucose, amino acids and lipids. Here, we report a significant role of cholesterol metabolism in cancer metastasis. By using label-free Raman spectromicroscopy, we found an aberrant accumulation of cholesteryl ester in human pancreatic cancer specimens and cell lines, mediated by acyl-CoA cholesterol acyltransferase-1 (ACAT-1) enzyme. Expression of ACAT-1 showed a correlation with poor patient survival. Abrogation of cholesterol esterification, either by an ACAT-1 inhibitor or by shRNA knockdown, significantly suppressed tumor growth and metastasis in an orthotopic mouse model of pancreatic cancer. Mechanically, ACAT-1 inhibition increased intracellular free cholesterol level, which was associated with elevated endoplasmic reticulum stress and caused apoptosis. Collectively, our results demonstrate a new strategy for treating metastatic pancreatic cancer by inhibiting cholesterol esterification.

Topical simvastatin promotes healing of Staphylococcus aureus-contaminated cutaneous wounds

Cutaneous wounds are prompt to be contaminated by bacteria, but the clinical benefits of applying antibiotics and antiseptics in wound management have not been proven. Statins are 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors commonly used to lower cholesterol levels. Studies indicated that statins, especially simvastatin, promote wound healing in experimental models. As Staphylococcus aureus is one of the most important microorganism responsible for wound infections, the aims of this study were to characterise the anti-staphylococcal activity of simvastatin and to evaluate the application of simvastatin as a topical therapy for S. aureus-contaminated wounds. In the present study, simvastatin was bacteriostatic against S. aureus at sub-inhibitory concentrations up to 8 hours after exposure. Further increased concentrations of simvastatin above the minimal inhibitory concentration (MIC) did not enhance the growth inhibitory effect. By contrast, the ability of simvastatin to inhibit S. aureus biofilm formation was concentration dependent. Topical application of simvastatin at its MIC against S. aureus accelerated the healing and bacterial clearance of S. aureus-contaminated wounds in an excisional mice wound model. This effective concentration is well below the safe concentration for topical use. Collectively, topical application of simvastatin has the potential as a novel modality for managing wound infections and promoting wound healing.

The Nuclear Orphan Receptor NR4A1 is Involved in the Apoptotic Pathway Induced by LPS and Simvastatin in RAW 264.7 Macrophages

Macrophage death plays a role in several physiological and inflammatory pathologies such as sepsis and arthritis. In our previous work, we showed that simvastatin triggers cell death in LPS-activated RAW 264.7 mouse macrophage cells through both caspase-dependent and independent apoptotic pathways. Here, we show that the nuclear orphan receptor NR4A1 is involved in a caspase-independent apoptotic process induced by LPS and simvastatin. Simvastatin-induced NR4A1 expression in RAW 264.7 macrophages and ectopic expression of a dominant-negative mutant form of NR4A1 effectively suppressed both DNA fragmentation and the disruption of mitochondrial membrane potential (MMP) during LPS- and simvastatin-induced apoptosis. Furthermore, apoptosis was accompanied by Bcl-2-associated X protein (Bax) translocation to the mitochondria. Our findings suggest that NR4A1 expression and mitochondrial translocation of Bax are related to simvastatin-induced apoptosis in LPS-activated RAW 264.7 macrophages.

HMG CoA reductase inhibitors (statins) for kidney transplant recipients

BACKGROUND

People with chronic kidney disease (CKD) have higher risks of cardiovascular disease compared to the general population. Specifically, cardiovascular deaths account most deaths in kidney transplant recipients. Statins are a potentially beneficial intervention for kidney transplant patients given their established benefits in patients at risk of cardiovascular disease in the general population. This is an update of a review first published in 2009.

OBJECTIVES

We aimed to evaluate the benefits (reductions in all-cause and cardiovascular mortality, major cardiovascular events, myocardial infarction and stroke, and progression of CKD to requiring dialysis) and harms (muscle or liver dysfunction, withdrawal, cancer) of statins compared to placebo, no treatment, standard care, or another statin in adults with CKD who have a functioning kidney transplant.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 29 February 2012 through contact with the Trials Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs that compared the effects of statins with placebo, no treatment, standard care, or statins on mortality, cardiovascular events, kidney function and toxicity in kidney transplant recipients.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed risk of bias. Treatment effects were expressed as mean difference (MD) for continuous outcomes (lipids, glomerular filtration rate (GFR), proteinuria) and relative risk (RR) for dichotomous outcomes (major cardiovascular events, mortality, fatal or non-fatal myocardial infarction, fatal or non-fatal stroke, elevated muscle or liver enzymes, withdrawal due to adverse events, cancer, end-stage kidney disease (ESKD), acute allograft rejection) together with 95% confidence intervals (CI).

MAIN RESULTS

We identified 22 studies (3465 participants); 17 studies (3282 participants) compared statin with placebo or no treatment, and five studies (183 participants) compared two different statin regimens.From data generally derived from a single high-quality study, it was found that statins may reduce major cardiovascular events (1 study, 2102 participants: RR 0.84, CI 0.66 to 1.06), cardiovascular mortality (4 studies, 2322 participants: RR 0.68, CI 0.45 to 1.01), and fatal or non-fatal myocardial infarction (1 study, 2102 participants: RR 0.70, CI 0.48 to 1.01); although effect estimates lack precision and include the possibility of no effect.Statins had uncertain effects on all-cause mortality (6 studies, 2760 participants: RR 1.08, CI 0.63 to 1.83); fatal or non-fatal stroke (1 study, 2102 participants: RR 1.18, CI 0.85 to 1.63); creatine kinase elevation (3 studies, 2233 participants: RR 0.86, CI 0.39 to 1.89); liver enzyme elevation (4 studies, 608 participants: RR 0.62, CI 0.33 to 1.19); withdrawal due to adverse events (9 studies, 2810 participants: RR 0.89, CI 0.74 to 1.06); and cancer (1 study, 2094 participants: RR 0.94, CI 0.82 to 1.07).Statins significantly reduced serum total cholesterol (12 studies, 3070 participants: MD -42.43 mg/dL, CI -51.22 to -33.65); low-density lipoprotein cholesterol (11 studies, 3004 participants: MD -43.19 mg/dL, CI -52.59 to -33.78); serum triglycerides (11 studies, 3012 participants: MD -27.28 mg/dL, CI -34.29 to -20.27); and lowered high-density lipoprotein cholesterol (11 studies, 3005 participants: MD -5.69 mg/dL, CI -10.35 to -1.03).Statins had uncertain effects on kidney function: ESKD (6 studies, 2740 participants: RR 1.14, CI 0.94 to 1.37); proteinuria (2 studies, 136 participants: MD -0.04 g/24 h, CI -0.17 to 0.25); acute allograft rejection (4 studies, 582 participants: RR 0.88, CI 0.61 to 1.28); and GFR (1 study, 62 participants: MD -1.00 mL/min, CI -9.96 to 7.96).Due to heterogeneity in comparisons, data directly comparing differing statin regimens could not be meta-analysed. Evidence for statins in people who have had a kidney transplant were sparse and lower quality due to imprecise effect estimates and provided limited systematic evaluation of treatment harm.

AUTHORS' CONCLUSIONS

Statins may reduce cardiovascular events in kidney transplant recipients, although treatment effects are imprecise. Statin treatment has uncertain effects on overall mortality, stroke, kidney function, and toxicity outcomes in kidney transplant recipients. Additional studies would improve our confidence in the treatment benefits and harms of statins on cardiovascular events in this clinical setting.

Low-dosage statins reduce choroidal damage in hypercholesterolemic rabbits

PURPOSE

To describe the ultrastructural changes in the choroid of long-term hypercholesterolemic rabbits after a low-dosage statin treatment and to evaluate some pleiotropic effects of these drugs on the morphology of endothelial cells (EC) and vascular smooth-muscle cells (VSMC).

METHODS

New Zealand rabbits were divided into three groups: G0, fed a standard diet; G1, fed a 0.5% cholesterol-enriched diet for 8 months and G2, fed a 0.5% cholesterol-enriched diet for 8 months plus administration of fluvastatin sodium or pravastatin sodium at a dose of 2 mg/Kg/day each. Eyes were processed for transmission-electron microscopy.

RESULTS

G1 had a lipid build-up at the suprachoroidea that compressed the vascular layers with the lumens of the vessels to the point of collapse in some instances. By contrast, G2 underwent a substantial decrease in suprachoroidal foam cells and of lipids in the vascular layers while the vascular lumens were normal. The preservation of cytoplasmic organelles, caveolar system and other ultrastructural features of EC and VSMC in G2 contrasted with the numerous signs of necrosis observed in G1. Bruch's membrane (BM) in G2 contained fewer lipids and more collagen than in G1.

CONCLUSION

Treatment with a low dosage of fluvastatin sodium or pravastatin sodium reduced the lipid build-up as well as the macrophages in the choroid and restored the vascular lumens of choroidal vessels independently of the cholesterol effect. The normal ultrastructural features of choroidal EC and VSMC in statin-treated animals suggest that the endothelial function is preserved and the ischaemia reduced.

Fluvastatin increases bone mineral density in postmenopausal women

Although several studies have reported a lower risk of osteoporotic fracture in hypercholesterolemic patients (WHO IIa) treated with statin, longitudinal studies on the effects of statins on bone are lacking. The aim of the present study was to evaluate bone mineral density (BMD) and bone turnover changes induced by 3-year fluvastatin treatment in postmenopausal women. Twenty-eight consecutive postmenopausal non-diabetic, normotensive hypercholesterolemic women (64.0±3.6 years) were treated for 36 months with 30 mg/day fluvastatin and 28 non-diabetic, normotensive normocholesterolemic age- and body mass index-matched postmenopausal women served as the control subjects. The result revealed a significant increase of the BMD as compared with the level at the base line (p< 0.001) in the fluvastairn-treated group, from 6 months on ward after the start treatment. Significant differences of the BMD were found between the controls and fluvastatin-treated group (p< 0.001) were at 6, 12, 24 and 36 months after the start of the study. In conclusion our results, although obtained small sample of postmenopausal hypercholesterolemic women, suggest a probable favorable effect of fluvastatin on bone formation and BMD.

Cognitive function and antihypertensive treatment in the elderly: a 6-year follow-up study

Both antihypertensive treatment and statins were proved to reduce mortality and morbidity from cardiovascular disease in the elderly. Yet their effect on cognitive functions of the elderly is unclear. In this study, 518 elderly were interviewed at their home six years ago. BP was measured and antihypertensive drug treatment and cognitive functions were evaluated. 318 of the original sample were re-examined (81% of the survivors). We evaluated the selective survival in relation to changes in BP, the specific drug usage and cognitive functioning. Beta blocker treatment increased the odds of survival but also the odds of decline in MMSE and memory scores. ACE-I treatment was also associated with decline in memory. Subjects treated with CCB had improved MMSE scores, memory, and performed better on tasks requiring concentration. Statins treatment in this study did not show any affect on cognitive functions. Although most subjects were treated by more than one antihypertensive drug, less than half were normalized at baseline and only one quarter at follow-up. Despite the low normalization rate, antihypertensive treatment regimen had been hardly changed during the six years follow-up. The use of statins, however, increased dramatically: from 6% at baseline to almost half at follow-up. According to our findings CCB emerges as the best option for reducing BP in elderly patients. It appeared to improve cognitive functions without hampering survival.

Adaptive immunity and atherosclerosis

Atherosclerosis involves the formation of inflammatory arterial lesions and is one of the most common causes of death globally. It has been evident for more than 20 years that adaptive immunity and T cells in particular regulate the magnitude of the atherogenic pro-inflammatory response. T cells also influence the stability of the atherosclerotic lesion and thus the propensity for thrombus formation and the clinical outcome of disease. This review summarizes our current understanding of T cells in atherogenesis, including which antigens they recognize, the role of T cell costimulation/coinhibition, and their secretion of pro- and anti-inflammatory mediators. Furthermore, we outline future areas of research and potential clinical intervention strategies.

Simvastatin ameliorates established pulmonary hypertension through a heme oxygenase-1 dependent pathway in rats

BACKGROUND

Simvastatin has been shown to ameliorate pulmonary hypertension by several mechanisms in experimental animal models. In this study, we hypothesized that the major benefits of simvastatin in pulmonary hypertension occur via the heme oxygenase-1 pathway.

METHODS

Simvastatin (10 mg/kgw/day) was tested in two rat models of pulmonary hypertension (PH): monocrotaline administration and chronic hypoxia. The hemodynamic changes, right heart hypertrophy, HO-1 protein expression, and heme oxygenase (HO) activity in lungs were measured in both models with and without simvastatin treatment. Tin-protoporphyrin (SnPP, 20 micromol/kg w/day), a potent inhibitor of HO activity, was used to confirm the role of HO-1.

RESULTS

Simvastatin significantly ameliorated pulmonary arterial hypertension from 38.0 +/- 2.2 mm Hg to 22.1 +/- 1.9 mm Hg in monocrotaline-induced PH (MCT-PH) and from 33.3 +/- 0.8 mm Hg to 17.5 +/- 2.9 mm Hg in chronic hypoxia-induced PH (CH-PH) rats. The severity of right ventricular hypertrophy was significantly reduced by simvastatin in MCT-PH and CH-PH rats. Co-administration with SnPP abolished the benefits of simvastatin. Simvastatin significantly increased HO-1 protein expression and HO activity in the lungs of rats with PH; however co-administration of SnPP reduced HO-1 activity only. These observations indicate that the simvastatin-induced amelioration of pulmonary hypertension was directly related to the activity of HO-1, rather than its expression.

CONCLUSION

This study demonstrated that simvastatin treatment ameliorates established pulmonary hypertension primarily through an HO-1-dependent pathway.

HMG CoA reductase inhibitors (statins) for kidney transplant recipients

BACKGROUND

Cardiovascular deaths account for the majority of deaths in kidney transplant recipients and dyslipidaemia contributes significantly to their cardiovascular disease. Statins are widely used in kidney transplant patients given their established benefits in the general population, however evidence favouring their use is lacking.

OBJECTIVES

To assess the benefits and harms of statin therapy on mortality and renal outcomes in kidney transplant recipients.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), and hand searched reference lists of articles and scientific proceedings.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing statins with placebo, no treatment or other statins in kidney transplant recipients.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. Statistical analyses were performed using the random effects model after testing for heterogeneity. Results were expressed as mean difference (MD) for continuous outcomes (lipid parameters) and risk ratio (RR) for dichotomous outcomes (mortality, allograft rejection, liver enzymes, occurrence of rhabdomyolysis and study withdrawal) with 95% confidence intervals (CI).

MAIN RESULTS

Sixteen studies (3229 patients) comparing statins versus placebo (15) or another statin (1) were included. Compared to placebo, statins did not decrease all-cause mortality (14 studies: RR 1.30, 95% CI 0.54 to 3.12). Point estimates favoured statins in terms of cardiovascular mortality (13 studies: RR 0.68, 95% CI 0.46 to 1.03) and non-fatal cardiovascular events (1 study: RR 0.70, 95% CI 0.48 to 1.01), however the results were not statistically significant. Compared to placebo, the use of statins was associated with a significantly lower end of treatment average total cholesterol (10 studies: MD -42.33 mg/dL (1.26 mmol/L), 95% CI -53.02 to -31.64), LDL cholesterol (10 studies: MD -46.15 mg/dL (1.19 mmol/L), 95% CI -55.97 to -36.33) and triglycerides (10 studies: MD -25.46 mg/dL (0.26 mmol/L), 95% CI -33.95 to 16.9). There was no significant difference in the risk of acute rejection (5 studies: RR 0.61; 95% C.I.0.32 to 1.16.) No data on chronic rejection was available and no major toxicity was noted.

AUTHORS' CONCLUSIONS

Statins significantly reduced hyperlipidaemia and tended to reduce cardiovascular events in kidney transplant recipients, but no effect has yet been demonstrated for mortality outcomes. Most of the data was derived from one large long-term study. Considering the significant impact of statins on all-cause and cardiovascular mortality in the general and predialysis populations, more studies are needed in kidney transplant patients.

Prevention of atherosclerosis in patients living with HIV

INVESTIGATIONAL PRODUCT: Rosuvastatin (Crestor; Astra Zeneca).

ACTIVE INGREDIENTS

Rosuvastatin (5 mg).

STUDY TITLE

Prevention of Atherosclerosis in Patients Living with HIV.

PHASE OF STUDY

Phase III.

AIMS

PRIMARY AIM: To assess whether rosuvastatin therapy could slow the progression of the carotid intima-media thickness (C-IMT; as measured by the change in the mean IMT of the near and far walls of the distal common carotid arteries) over 2 years in HIV-infected patients (HIV-IP).

SECONDARY AIMS

To assess whether rosuvastatin therapy could reduce highly sensitive C reactive protein (hs-CRP) inflammatory marker that is increased in HIV-IP.To assess the effect of rosuvastatin therapy on serum lipid levels (total cholesterol [TC], low-density lipoprotein [LDL] cholesterol, high-density lipoprotein [HDL] cholesterol and triglycerides [TG]) and apolipoproteins (APO A1, APO B and APO B/A1).To assess the safety of rosuvastatin in HIV-IP through the evaluation of clinical laboratory analyses (liver function tests and creatine kinase) and adverse events (AEs).

STUDY DESIGN

Two-year randomized, double-blind, placebo-controlled, parallel group study.

PLANNED SAMPLE SIZE

320 HIV-IP.

SUMMARY OF ELIGIBILITY CRITERIA

HIV-IP who are aged between 30 and 60 years, with a CD4 count. greater than 200 cells/mm(3). Patients must be stable on combination antiretroviral therapy (cART) for at least 12 months and have a 10-year CVD risk of less than 20% (using the Framingham risk score).

NUMBER OF STUDY CENTERS

One.

DURATION OF TREATMENT

Two years (5 mg rosuvastatin or placebo once daily).

DOSE AND ROUTE OF ADMINISTRATION

Oral rosuvastatin (5 mg) once daily. The incidence of cardiovascular disease (CVD) in HIV-IP is at least three times higher than in the general population and further increases each year with combination anti-retroviral therapy (cART). The carotid atherosclerosis progression rate is 10 times higher in HIV-IP than in uninfected individuals. The aim of this study is to assess whether therapy with 5 mg rosuvastatin could: 1) Slow the progression in the mean IMT of the distal common carotid arteries over two years in HIV-IP.2) Change the concentration in the inflammatory marker--hs-CRP, which is increased in HIV-IP.3) Change the concentrations of TC, LDL cholesterol, HDL cholesterol, TG, apolipoproteins (APO) B, APO A1 and APO B/A1.4) Be administered safely in the study population. Pharmacological intervention with rosuvastatin will be evaluated in a double-blind, placebo-controlled, randomized clinical trial in HIV-IP treated with cART not matching the published selection criteria for lipid-lowering therapy. For the first time, this study will investigate anti-inflammatory and anti-atherogenic effects of a pharmacological lipid-lowering agent in HIV-IP that may lead to the reduction of CVD.

Working together: Farnesyl transferase inhibitors and statins block protein prenylation

Farnesyl transferase inhibitors (FTIs) have so far proved to have limited value as single agents in clinical trials. This PharmSight will focus on the use of a novel group of FTIs that are most effective in vitro when used in combination with the "statin" class of anti-hypercholesterolemic agents, which also block protein prenylation. We recently showed that these novel FTIs in combination with lovastatin reduce Ras prenylation and induce an apoptotic response in malignant peripheral nerve sheath cells. The combination of statins with these new FTIs may produce profound synergistic cytostatic and cytotoxic effects against a variety of tumors and other proliferative disorders. Since statins are well tolerated in the clinic, we suggest that this combination approach should be tested in in vivo models.

Fluvastatin prevents podocyte injury in a murine model of HIV-associated nephropathy

BACKGROUND

Recent studies have reported that statins have renoprotective effects, independent from lowering plasma cholesterol. In this study, we examined whether statins were beneficial in a murine model of HIV-associated nephropathy (HIVAN).

METHODS

We used conditional transgenic mice that express one of the HIV-1 accessory genes, vpr, selectively in podocytes using podocin promoter and the Tet-on system. These mice develop aggressive collapsing focal segmental glomerular sclerosis with massive proteinuria and deterioration of renal function within 4 weeks following heminephrectomy and doxycycline administration. Fluvastatin was administrated simultaneously with doxycycline, and the effect was compared with untreated controls after 4 weeks.

RESULTS

Fluvastatin at 10 mg/kg/day significantly decreased urinary albumin excretion (87 versus 11 mg/day, P < 0.01) and glomerular sclerosis (2.4 versus 1.0, P < 0.01, assessed by semi-quantitative scoring: 0-4). Fluvastatin also decreased serum creatinine and total cholesterol, but these differences were not statistically significant (0.36 versus 0.32 mg/dl, P = 0.35; 492 versus 378 mg/dl, P = 0.11, respectively). Phenotypic changes in podocytes, as indicated by the downregulation of nephrin, Wilms' tumour 1 and synaptopodin, along with upregulation of proliferating cell nuclear antigen, were attenuated by fluvastatin, suggesting its protective effects against podocyte injuries. In cultured podocytes, angiotensin II treatment decreased nephrin expression to 13% of basal levels, which was reversed to 58% by adding fluvastatin.

CONCLUSIONS

In conclusion, fluvastatin was effective in treating experimental HIVAN. The beneficial effect of this drug might be caused, in part, by preserving nephrin expression in podocytes against angiotensin II-mediated injury.

Present and future drug treatments for chronic kidney diseases: evolving targets in renoprotection

At present, there are no specific cures for most of the acquired chronic kidney diseases, and renal transplantation is limited by organ shortage, therefore present efforts are concentrated on the prevention of progression of renal diseases. There is robust experimental and clinical evidence that progression of chronic nephropathies is multifactorial; however, intraglomerular haemodynamic changes and proteinuria play a key role in this process. With a focus on renoprotection, we first examine more established therapies--such as those that modulate the renin-angiotensin-aldosterone system--that can be used for the treatment of proteinuric renal diseases. We then discuss examples of novel drugs and biologics that might be used to target the inflammatory and profibrotic process, and glomerular injury, highlighting results from recent clinical trials.

Use of statins and incidence of dementia and cognitive impairment without dementia in a cohort study

OBJECTIVE

Evidence of a relation between use of lipid lowering drugs and cognitive outcomes is mixed. This study aimed to test the association between use of statins and incidence of dementia and cognitive impairment without dementia (CIND) over 5 years of follow-up.

METHODS

Data were from a population-based cohort study comprising 1,789 older Mexican Americans. All participants had cognitive and clinical evaluations performed every 12 to 15 months. Participants who fell below specified cutpoints on cognitive tests were then evaluated clinically. Dementia diagnoses were finalized by an adjudication team. A total of 1,674 participants free of dementia/CIND at baseline were included in these analyses. Statin use was verified at each participant's home by medicine cabinet inspection. Cox proportional hazards models were used to evaluate the association between statin use and incidence of dementia/CIND.

RESULTS

Overall, 452 of 1,674 participants (27%) took statins at any time during the study. Over the 5-year follow-up period, 130 participants developed dementia/CIND. In Cox proportional hazards models adjusted for education, smoking status, presence of at least one APOE epsilon4 allele, and history of stroke or diabetes at baseline, persons who had used statins were about half as likely as those who did not use statins to develop dementia/CIND (HR = 0.52; 95% CI 0.34, 0.80).

CONCLUSION

Statin users were less likely to have incident dementia/cognitive impairment without dementia during a 5-year follow-up. These results add to the emerging evidence suggesting a protective effect of statin use on cognitive outcomes.

Atorvastatin induces associated reductions in platelet P-selectin, oxidized low-density lipoprotein, and interleukin-6 in patients with coronary artery diseases

The development and progression of atherosclerosis comprises various processes, such as endothelial dysfunction, chronic inflammation, thrombus formation, and lipid profile modification. Statins are 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors that have pleiotropic effects in addition to cholesterol-lowering properties. However, the mechanisms of these effects are not completely understood. Here, we investigated whether atorvastatin affects the levels of malondialdehyde-modified low-density lipoprotein (MDALDL), an oxidized LDL, the proinflammatory cytokine interleukin-6 (IL-6), or platelet P-selectin, a marker of platelet activation, relative to that of LDL cholesterol (LDL-C). Forty-eight patients with coronary artery disease and hyperlipidemia were separated into two groups that were administered with (atorvastatin group) or without (control group) atorvastatin. The baseline MDA-LDL level in all participants significantly correlated with LDL-C (r = 0.71, P < 0.01) and apolipoprotein B levels (r = 0.66, P < 0.01). Atorvastatin (10 mg/day) significantly reduced the LDL-C level within 4 weeks and persisted for a further 8 weeks of administration. Atorvastatin also reduced the MDA-LDL level within 4 weeks and further reduced it over the next 8 weeks. Platelet P-selectin expression did not change until 4 weeks of administration and then significantly decreased at 12 weeks, whereas the IL-6 level was gradually, but not significantly, reduced at 12 weeks. In contrast, none of these parameters significantly changed in the control group within these time frames. The reduction (%) in IL-6 between 4 and 12 weeks after atorvastatin administration significantly correlated with that of MDALDL and of platelet P-selectin (r = 0.65, P < 0.05 and r = 0.70, P < 0.05, respectively). These results suggested that the positive effects of atorvastatin on the LDL-C oxidation, platelet activation and inflammation that are involved in atherosclerotic processes are exerted in concert after lowering LDL-C.

HMG-CoA reductase inhibitor regulates endothelial progenitor function through the phosphatidylinositol 3'-kinase/AKT signal transduction pathway

HMG-CoA reductase inhibitor (statins) are known to have pleiotropic effects. We examined the effect and mechanism of simvastatin on peripheral endothelial progenitor cells (EPCs). Rats were divided into simvastatin group and the control group after cardiac infarction operation. Simvastatin treatment significantly increased the number of peripheral blood CD34+ CD133+ cells, and serum concentration of vascular endothelial growth factor (VEGF) and AKT was markedly increased in vivo. In cultured EPC, simvastatin increased the concentrations of VEGF, AKT and eNOS. Western blots analysis showed that simvastatin increased the phosphorylation of eNOS and FKHRL1, which can be blocked by the PI3K/AKT pathway blocker LY294002 . Our study demonstrated that simvastatin increases the mobilization of EPCs after cardiac infarction. In in vitro study, simvastatin increases the phosphorylation of eNOS and of FKHRL1 through the PI3K/AKT signaling pathway.

Reduced thyroid volume and nodularity in dyslipidaemic patients on statin treatment

BACKGROUND

Little information is available concerning the possible antiproliferative effects of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) on the thyroid gland. We have hypothesized that the antiproliferative effects of statins observed in thyroid cell lines in vitro may have a clinical counterpart that could be detected by investigating the prevalence and size of thyroid nodules in patients on long-term treatment with statins.

METHODS

We retrospectively evaluated 135 dyslipidaemic patients receiving statin therapy continuously for at least 5 years, and 137 controls. All the subjects were submitted to ultrasound investigation of the thyroid gland, to establish prevalence, number and volume of thyroid nodules.

RESULTS

Subjects treated with statins showed markedly lower prevalence of thyroid nodules (36.3%vs. 67.9%, P < 0.001), as well as reduced number and smaller total volume of lesions, as compared to the control group. A logistic regression analysis, taking into account age, sex, risk factors for the development of thyroid nodules and concomitant drug treatment, revealed that treatment with statins remained the only important predictor of the presence of thyroid nodules [odds ratio (OR) 0.312, 95% confidence interval (CI) 0.156-0.625, P < 0.001] besides risk factors.

CONCLUSIONS

Our data provide the first circumstantial evidence of an association between HMG-CoA reductase inhibitor treatment and reduced prevalence, number and volume of thyroid nodules. This finding may be explained by an antiproliferative and/or pro-apoptotic effect of long-term statin treatment on thyroid cells, in vivo.

Statin-induced heme oxygenase-1 increases NF-kappaB activation and oxygen radical production in cultured neuronal cells exposed to lipopolysaccharide

With potentially neuroprotective properties, heme oxygenase-1 (HO-1) has been suggested to be the main mediator of cholesterol-independent anti-inflammatory and antioxidant actions of statins. However, we had demonstrated that simvastatin-induced HO-1 increased apoptosis of Neuro 2A cells in glucose deprivation, and iron production from HO-1 activity may be responsible for the toxicity. This study was designed to explore the effect of simvastatin-induced HO-1 on cultured Neuro 2A and C6 cells exposed to lipopolysaccharide (LPS). We found that the HO-1 upregulation was significantly associated with increased nuclear factor kappa B (NF-kappaB) activation, manifested as IkappaBalpha phosphorylation and p65 nuclear translocation, as well as increased production of superoxides. Inhibition of the induced HO-1 by zinc protoporphyrin reduced the increased NF-kappaB activation and superoxides production. RNA interference with HO-1 siRNA reduced the expression of HO-1 transcripts and protein as well as oxygen radical production. Addition of the iron chelator desferrioxamine to reduce the accumulation of ferric iron from heme by HO-1 resulted in blockade of the aggravated oxygen radical production. There was no significant effect on production of oxygen radicals under these conditions in the presence of a CO donor (RuCO) or a CO scavenger (hemoglobin). In addition, the viable cells were significantly decreased in 48 h in those cells receiving simvastatin pretreatment plus LPS compared to those in control or exposed to simvastatin or LPS alone. This study revealed that simvastatin-induced HO-1 led to increased NF-kappaB activation and superoxides production in the neuronal cells when exposed to LPS, and iron production may play a role in such a response.

Chronic fluvastatin treatment alters vascular contraction by inhibiting the Rho/Rho-kinase pathway

1. In the present study, we investigated the effects of chronic treatment of stroke-prone spontaneously hypertensive rats (SHRSP) with the statin fluvastatin on vascular Rho/Rho-kinase pathway mediated contraction, which has been shown to be upregulated in hypertension. 2. Contribution of the Rho/Rho-kinase pathway to noradrenaline-induced contraction of arteries from SHRSP was assessed by the inhibitory effect of Y-27632, a Rho/Rho-kinase inhibitor. Stroke-prone spontaneously hypertensive rats were treated with fluvastatin (10 mg/kg per day) for 1 month. 3. Treatment with fluvastatin tended to attenuate the contraction to noradrenaline and significantly decreased the Y-27632-sensitive component of the contraction in controls compared with fluvastatin-treated rats. 4. RhoA, as assessed by western blotting, was also reduced by fluvastatin treatment. 5. These findings suggest that chronic treatment with fluvastatin reduces the contractile response associated with Rho/Rho-kinase in arteries of hypertensive rats.

Statin treatment increases formation of carbon monoxide and bilirubin in mice: a novel mechanism of in vivo antioxidant protection

Heme oxygenase (HO) has a central role in cellular antioxidant defences and vascular protection, and it may mediate pleiotropic actions of drugs used in cardiovascular therapy. We investigated whether long-term use of statins upregulates HO activity and increases carbon monoxide (CO) and bilirubin levels in vivo. Adult FvB mice were given atorvastatin or rosuvastatin (5 mg/kg) daily by i.p. injections for 1, 2, or 3 weeks. HO activity, tissue CO, bilirubin, and antioxidant levels, total plasma bilirubin, and carboxyhemoglobin (COHb) were measured. Fold changes in heart HO activity significantly increased after 1, 2, and 3 weeks of atorvastatin (1.24 ± 0.06 (p ≤ 0.05); 1.29 ± 0.26 (p ≤ 0.03); 1.33 ± 0.08 (p < 0.01), respectively) and 2 and 3 weeks of rosuvastatin (1.23 ± 0.20 (p ≤ 0.03); 1.63 ± 0.42 (p < 0.01), respectively). Heart tissue CO and COHb levels also increased after 3 weeks with atorvastatin (1.30 ± 0.24 (p ≤ 0.05); 1.92 ± 0.17 (p ≤ 0.001), respectively) and rosuvastatin (1.47 ± 0.13 (p ≤ 0.004); 1.63 ± 0.12 (p ≤ 0.001), respectively). Significant increases in heart antioxidant levels were observed after statin treatment and corroborated by heart bilirubin content elevations. Antioxidant level increases were abolished by treatment with an HO inhibitor. These findings suggest that the induction of HO and the production of its products, CO and bilirubin, may be a mechanism by which statins exert antioxidant actions and confer cardioprotection in vivo.

Synthesis, biochemical, and cellular evaluation of farnesyl monophosphate prodrugs as farnesyltransferase inhibitors

Certain farnesyl diphosphate (FPP) analogs are potent inhibitors of the potential anticancer drug target protein farnesyltransferase (FTase), but these compounds are not suitable as drug candidates. Thus, phosphoramidate prodrug derivatives of the monophosphate precursors of FPP-based FTase inhibitors have been synthesized. The monophosphates themselves were significantly more potent inhibitors of FTase than the corresponding FPP analogs. The effects of the prodrug 5b (a derivative of 3-allylfarnesyl monophosphate) have been evaluated on prenylation of RhoB and on the cell cycle in a human malignant schwannoma cell line (STS-26T). In combination treatments, 1-3 microM 5b plus 1 microM lovastatin induced a significant inhibition of RhoB prenylation, and a combination of these drugs at 1 microM each also resulted in significant cell cycle arrest in G1. Indeed, combinations as low as 50 nM lovastatin + 1 microM 5c or 250 nM lovastatin + 50 nM 5c were highly cytostatic in STS-26T cell culture.

Fluvastatin Alters Platelet Aggregability in Patients With Hypercholesterolemia

BACKGROUND

Hypercholesterolemia enhances platelet aggregability. Statins have beneficial effects on cardiovascular events. The purpose of this study is to investigate whether statins inhibit platelet aggregation and, if so, the mechanisms.

METHODS AND RESULTS

Twelve patients with hypercholesterolemia were prospectively randomized in a crossover design to receive either fluvastatin (20 mg/d) or colestimide (3000 mg/d) for 12 weeks. The subjects were switched to the opposite arm for additional 12 weeks. Before and after first and second treatments, experiments were performed. Eleven age-matched volunteers with normal lipid profiles served as controls. ADP-induced platelet aggregation, platelet-derive nitric oxide (PDNO) release, intraplatelet levels of GSH and GSSG, and intraplatelet nitrotyrosine production during platelet aggregation were measured. Fluvastatin and colestimide equally lowered total and low density lipoprotein cholesterol levels in hypercholesterolemia. Platelet aggregation was greater in hypercholesterolemia than in normocholesterolemia before treatment and was altered by fluvastatin. PDNO release, intraplatelet glutathione level, and GSH/GSSG ratio were lower in hypercholesterolemia than in normocholesterolemia before treatment and were increased by fluvastatin. Intraplatelet nitrotyrosine formation was greater in hypercholesterolemia than in normocholesterolemia, and decreased by fluvastatin. Colestimide did not have such effects. In vitro application of fluvastatin dose-dependently inhibited platelet aggregation. Furthermore, in vitro application of fluvastatin dose-dependently inhibited platelet nitrotyrosine expressions and the inhibitory effects by fluvastatin were reversed by preincubation with geranylgeranylpyrophosphate.

CONCLUSIONS

Fluvastatin altered platelet aggregability in hypercholesterolemic patients in a cholesterol-lowering independent manner, which was partly mediated by the improvement of intraplatelet redox imbalance.

Simvastatin Increases Neutrophil Apoptosis and Reduces Inflammatory Reaction After Coronary Surgery

BACKGROUND

Neutrophils play a central role in systemic inflammatory reaction after cardiopulmonary bypass. Apoptosis is significantly delayed, and this might exacerbate systemic and myocardial damage. We tested the hypothesis of whether pretreatment with simvastatin increases the apoptotic rate of neutrophils and hence reduces the entity of inflammatory reaction.

METHODS

Thirty patients undergoing coronary surgery with cardiopulmonary bypass were randomized to treatment with either simvastatin (40 mg/day) or placebo for 3 weeks before surgery. A group of 15 patients undergoing off-pump coronary surgery served as controls. Blood samples for detection of serum cytokine levels were obtained before anesthesia, at the end of surgery, and at 4, 24, 48, and 72 hours postoperatively. Apoptosis and indices of activation were assessed in cultured neutrophils.

RESULTS

Simvastatin significantly reduced the postoperative peak values of interleukin (IL)-6 and IL-8. The neutrophil apoptotic rate was significantly higher among neutrophils obtained from patients pretreated with simvastatin (p < 0.05 at both 8 and 24 hours) compared with placebo. Neutrophils from the statin group had depressed functional activity, as underscored by significantly lower values of CD11b (p < 0.01 at 24 hours) and a significantly less percentage of cells positive for nitro-blue tetrazolium (p < 0.01 at 12 and 24 hours) compared with placebo.

CONCLUSIONS

This randomized, double-blind study indicates that statin therapy before cardiopulmonary bypass is associated with reduction of circulating markers of inflammation and increased neutrophil apoptosis. These data support a routine inclusion of statins as an adjuvant pharmacologic therapy before cardiopulmonary bypass surgery.

Human umbilical vein endothelial cells and human dermal microvascular endothelial cells offer new insights into the relationship between lipid metabolism and angiogenesis

Human umbilical vein endothelial cells (HUVECs) have played a major role as a model system for the study of the regulation of endothelial cell function and the role of the endothelium in the response of the blood vessel wall to stretch, shear forces, and the development of atherosclerotic plaques and angiogenesis. Here, we use HUVECs and human microvascular endothelial cells to study the role of the HMG-CoA reductase inhibitor, simvastatin, and the small GTP-binding protein Rho in the regulation of angiogenesis. Simvastatin inhibited angiogenesis in response to FGF-2 in the corneal pocket assay of the mouse and in vascular endothelial growth factor (VEGF)-stimulated angiogenesis in the chick chorioallontoic membrane. Furthermore, simvastatin inhibited VEGF-stimulated tube formation by human dermal microvascular endothelial cells and the formation of honeycomb-like structures by HUVECs. The effect was dose-dependent and was not secondary to apoptosis. Geranylgeranyl-pyrophosphate (GGPP), a product of the cholesterol metabolic pathway that serves as a substrate for the posttranslational lipidation of RhoA, was required for membrane localization, but not farnesylpyrophosphate (FPP), the substrate for the lipidation of Ras. Furthermore, GGTI, a specific inhibitor of GGPP, mimicked the effect of simvastatin of tube formation and the formation of honeycombs whereas FTI, a specific inhibitor of the farnesylation of Ras, had no effect. Adenoviral expression of a DN-RhoA mutant mimicked the effect of simvastatin on tube formation and the formation of honeycombs, whereas a dominant activating mutant of RhoA reversed the effect of simvastatin on tube formation. Finally, simvastatin interfered with the membrane localization of RhoA with a dose-dependence similar to that for the inhibition of tube formation. Simvastatin also inhibited the VEGFstimulated phosphorylation of the VEGF receptor KDR, and the tyrosine kinase FAK, which plays a role in cell migration. These data demonstrate that simvastatin interfered with angiogenesis via the inhibition of RhoA. Data supporting a role for angiogenesis in the development and growth of atherosclerotic plaques suggest that this antiangiogenic effect of Statins might prevent the progression of atherosclerosis via the inhibition of plaque angiogenesis.

Short-term effects of atorvastatin on bone turnover in male patients with hypercholesterolemia

No consensus has been reached on whether the 3-hydroxy 3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, known as statins, have beneficial effects on bone health. The purpose of our study was to evaluate the effects of atorvastatin on bone metabolism by means of measuring bone turnover markers in male patients with hypercholesterolemia both at diagnosis and prospectively after 3 months of treatment. Twenty-two Japanese male patients (mean age 62.36 +/- 10.1 years) with untreated hypercholesterolaemeia were selected for this study. After 3-months treatment of atorvastatin, total cholesterol and low density lipoprotein cholesterol significantly decreased as expected (p<0.001 for both parameters). Bone-specific alkaline phosphatase (BAP) did not change significantly (p = 0.444). However, serum N-terminal telopeptide of type I collagen (NTx) significantly decreased by -19.86 +/- 26.4% (p = 0.020). In addition, delta NTx during the course of this study was negatively correlated with NTx at baseline (r = -0.645, p = 0.0008). Although there was a tendency of positive correlations of delta NTx with delta total cholesterol, delta triglycerides, and delta low density lipoprotein cholesterol, and of negative correlations of delta NTx and delta BAP with delta high density lipoprotein cholesterol, none of them reached statistical significance. Our findings suggest that atorvastatin may have potentially beneficial effects on bone metabolism in patients with hypercholesterolemia mostly by reducing bone resorption rather than by stimulating bone formation. Further studies with more patients and longer duration are warranted to evaluate its effects, if any, on prevention of osteoporosis and subsequent fractures.

Controlling oxidative stress as a novel molecular approach to protecting the vascular wall in diabetes

PURPOSE OF REVIEW

In diabetes, oxidative stress plays a key role in the pathogenesis of vascular complications; therefore an antioxidant therapy would be of great interest in this disease.

RECENT FINDINGS

Hyperglycemia directly promotes an endothelial dysfunction--inducing process of overproduction of superoxide at the mitochondrial level. This is the first and key event able to activate all the pathways involved in the development of vascular complications of diabetes. It has recently been shown that statins, angiotensin-converting enzyme inhibitors, angiotensin II type 1 blockers, calcium channel blockers, and thiazolidinediones have a strong intracellular antioxidant activity.

SUMMARY

Classic antioxidants, such as vitamin E, failed to show beneficial effects on diabetic complications probably because their action is only "symptomatic". The preventive activity against hyperglycemia-induced oxidative stress shown by statins, angiotensin-converting enzyme inhibitors, angiotensin II type 1 blockers, calcium channel blockers, and thiazolidinediones justifies use of these compounds for preventing complications in patients with diabetes, in whom antioxidant defences have been shown to be defective.

HMG-CoA reductase inhibitor fluvastatin prevents angiotensin II-induced cardiac hypertrophy via Rho kinase and inhibition of cyclin D1

HMG-CoA reductase inhibitors, so called statins, decrease cardiac events. Previous studies have shown that HMG-CoA reductase inhibitors inhibit cardiomyocyte hypertrophy in vitro and in vivo by blocking Rho isoprenylation. We have shown that the G1 cell cycle regulatory proteins cyclin D1 and Cdk4 play important roles in cardiomyocyte hypertrophy. However, the relation between Rho and cyclin D1 in cardiomyocyte is unknown. To investigate whether HMG-CoA reductase inhibitors prevent cardiac hypertrophy through attenuation of Rho and cyclin D1, we studied the effect of fluvastatin on angiotensin II-induced cardiomyocyte hypertrophy in vitro and in vivo. Angiotensin II increased the cell surface area and [(3)H]leucine uptake of cultured neonatal rat cardiomyocytes and these changes were suppressed by fluvastatin treatment. Angiotensin II also induced activation of Rho kinase and increased cyclin D1, both of which were also significantly suppressed by fluvastatin. Specific Rho kinase inhibitor, Y-27632 inhibited angiotensin II-induced cardiomyocyte hypertrophy and increased cyclin D1. Overexpression of cyclin D1 by adenoviral gene transfer induced cardiomyocyte hypertrophy, as evidenced by increased cell size and increased protein synthesis; this hypertrophy was not diminished by concomitant treatment with fluvastatin. Infusion of angiotensin II to Wistar rats for 2 weeks induced hypertrophic changes in cardiomyocytes, and this hypertrophy was prevented by oral fluvastatin treatment. These results show that an HMG-CoA reductase inhibitor, fluvastatin, prevents angiotensin II-induced cardiomyocyte hypertrophy in part through inhibition of cyclin D1, which is linked to Rho kinase. This novel mechanism discovered for fluvastatin could be revealed how HMG-CoA reductase inhibitors are preventing cardiac hypertrophy.

Atorvastatin inhibits inflammatory hypernociception

BACKGROUND AND PURPOSE

Atorvastatin is an inhibitor of the enzyme 3-hydroxyl-3-methylglutaryl coenzyme A reductase used to prevent coronary heart disease. We have studied the analgesic effect of atorvastatin in inflammatory models in which a sequential release of mediators (bradykinin, (BK), tumour necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and the chemokine, KC/CXCL) links the stimulus with release of directly acting hypernociceptive mediators such as prostaglandin E(2) (PGE(2)).

EXPERIMENTAL APPROACH

The effects of orally administered atorvastatin on inflammatory mechanical hypernociception in mouse paws were evaluated with an electronic pressure-meter. Cytokines and PGE(2) were measured by ELISA and RIA.

KEY RESULTS

Treatment with atorvastatin for 3 days dose-dependently reduced hypernociception induced by lipopolysaccharide (LPS) or that following antigen challenge in sensitized animals. Atorvastatin pre-treatment reduced hypernociception induced by bradykinin and cytokines (TNF-alpha, IL-1beta and KC), and the release of IL-1beta and PGE(2) in paw skin, induced by lipopolysaccharide. The antinociceptive effect of atorvastatin on LPS-induced hypernociception was prevented by mevalonate co-treatment without affecting serum cholesterol levels. Hypernociception induced by PGE(2) was inhibited by atorvastatin, suggesting intracellular antinociceptive mechanisms for atorvastatin. The antinociceptive effect of atorvastatin upon LPS- or PGE(2)-induced hypernociception was prevented by non-selective inhibitors of nitric oxide synthase (NOS) but not by selective inhibition of inducible NOS or in mice lacking this enzyme.

CONCLUSIONS AND IMPLICATIONS

Antinociceptive effects of atorvastatin depend on inhibition of cytokines and prostanoid production and on stimulation of NO production by constitutive NOS. Our study suggests that statins may constitute a novel class of analgesic drugs.

Statins inhibit NK cell cytotoxicity by membrane raft depletion rather than inhibition of isoprenylation

To investigate the potential determinants of the pleiotropic effects of statins, we measured NK cell cytotoxicity in samples from normal subjects and patients, including patients receiving statin therapy. In a multivariate analysis, NK cell cytotoxicity was related to total plasma cholesterol concentration rather than statin use. In vitro, we investigated the role of lipid modification, specifically the effects on membrane rafts and raft-dependent signal transduction. We demonstrate that statins reduce NK cell cytotoxicity and that membrane cholesterol depletion by cyclodextrins has a similar effect. In contrast, isoprenyl transferase inhibitors had little or no effect on NK cell function. We hypothesise that the pleiotropic effects of statins reflect changes in membrane cholesterol and, specifically, the density of membrane rafts. Moreover, there is likely to be a relationship between membrane cholesterol, membrane rafts and cell function that may be involved in the pathogenesis of cardiovascular and metabolic diseases.

Tissue-specific effects of statins on the expression of heme oxygenase-1 in vivo

Heme oxygenase-1 (HO-1) plays a central role in antioxidant and anti-inflammatory actions, which may be mediated through its formation of biliverdin/bilirubin and carbon monoxide. HMG-CoA reductase inhibitors (statins) induce in vitro HO-1 expression and are reported to have pleiotropic benefits that reduce oxidative stress in the vasculature. We characterized the effects of statins on in vivo HO-1 expression in various extravascular tissues: liver, lung, brain, and heart. Adult mice were orally administered simvastatin, lovastatin, atorvastatin, or rosuvastatin. HO activity significantly increased in a statin- and tissue-specific manner, with all statins increasing heart and lung activity within 24 h. Significant elevations of HO-1 protein and mRNA were also observed in heart and lung after atorvastatin treatment. We conclude that in vivo HO-1 induction is statin- and tissue-specific. Through this pathway, statins may confer antioxidant and anti-inflammatory actions in the vasculature and extravascular systems.

Statins and myocardial hypertrophy

Cardiac hypertrophy is a physiological adaptive response by the heart to pressure overload. However, after prolonged periods, this initial adaptive response becomes maladaptive, leading to increased mortality and morbidity from heart failure. Recently, 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or statins, have been shown to inhibit cardiac hypertrophy by cholesterol-independent mechanisms. Statins block the isoprenylation and activation of members of the Rho guanosine triphosphatase (GTPase) family, such as RhoA and Rac1. Since Rac1 is a requisite component of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, which is a major source of reactive oxygen species (ROS) in cardiovascular cells, the ability of statins to inhibit Rac1-mediated oxidative stress makes an important contribution to their inhibitory effects on cardiac hypertrophy.

Simvastatin Reduces Serum Level of Vascular Endothelial Growth Factor in Hypercholesterolemic Patients

Vascular endothelial growth factor plays a pivotal role in the progression of atherosclerotic lesions and causes instability of atherosclerotic plaques by inducing neoangiogenesis inside the current plaque. The pro-inflammatory cytokine interleukin (IL-) 6 induces vascular endothelial growth factor in smooth muscle cells (SMC). HMG-CoA reductase inhibitors (statins), display beside their lipid-lowering potency various pleiotropic effects. Such pleiotropic effects include improvement of endothelial dysfunction, increased nitric oxide bioavailability, antioxidant properties, inhibition of inflammatory responses, and stabilization of atherosclerotic plaques. In this study we investigate the influence of statin treatment on the serum levels of VEGF in hypercholesterolemic patients. One hundred and seven hypercholesterolemic patients were treated with 20 (n = 52) or 40 mg (n = 55) simvastatin daily. Six weeks of treatment resulted in a significant decrease of VEGF from 1017.1 +/- 297.8 pg/mL at baseline to 543.5 +/- 317.4 pg/mL after 6 weeks (-47.7%) and to 211.8 +/- 155.3 pg/mL after 6 months (-79.7%; all P < 0.001). IL-6 induced the expression of vascular endothelial growth factor in human SMC as analyzed by rt-PCR and flow cytometry. Statins decreased the stimulatory effect of IL-6 on mRNA and protein levels. This effect could be inhibited by co-incubation with mevalonate acid. This study contributes in understanding the pleiotropic effects of statins particularly with regard to their use in treatment and prevention of cardiovascular disease.

Preoperative statin use and outcomes following cardiac surgery

BACKGROUND

Cardiac surgery carries a 2-3% early mortality due in part to perioperative myocardial infarction (PMI), low-output syndrome (LOS), and arrhythmias. Statins attenuate thrombogenesis, normalize endothelial dysfunction, and mitigate the oxidative stress and reperfusion injury characteristic of such complications. We sought to determine whether preoperative statin use is associated with reduced early mortality and major morbidity following cardiac surgery.

METHODS

Patients having isolated coronary artery bypass grafting (CABG), valve, or combined CABG/valve surgery between May 1998 and June 2003 (n=5469) were identified. A logistic regression model was generated to determine the association of preoperative statin use with in-hospital mortality (IHM). Propensity score analysis was used to match two subgroups of patients (Group I, on statins, n=1443; Group II, not on statins, n=1443) on multiple factors known to impact cardiac surgical outcome. Outcomes assessed were IHM, intra-aortic balloon pump (IABP) use, PMI, prolonged (>24 h) ventilation (p-vent), stroke, and a composite end point (comp) defined as any one or more of the above.

RESULTS

Of the 5469 patients, 3555 were on statins and 1914 were not. Unadjusted rates of IHM (2.6% vs. 5.0%), stroke (1.9% vs. 3.3%), p-vent (10.2% vs. 16.6%), and comp (12.7% vs. 19.5%) were lower (p=0.0001) in patients receiving statins. After adjustment, statin use was not associated with a reduction in IHM (OR=0.9, 95% CI=0.6-1.2, p=0.36) or comp (OR=0.9, 95% CI=0.8-1.1, p=0.31). After matching two subgroups using propensity score for statin, no significant differences were found in any of the adjusted outcomes for Group I vs. Group II: IHM (4.0% vs. 4.6%), PMI (1.5% vs. 1.1%), p-vent (15.8% vs. 15.7%), IABP use (2.0% vs. 2.3%), stroke (3.0% vs. 3.3%), and comp (19.1% vs. 18.8%).

CONCLUSIONS

Preoperative statin use is not associated with a reduction in IHM or major morbidity following cardiac surgery.

Statins downregulate myeloperoxidase gene expression in macrophages

Statins, inhibitors of HMG-CoA reductase, have pleiotropic benefits independent of cholesterol levels, including anti-oxidant and anti-inflammatory effects. Here, we investigate the effect of statins on myeloperoxidase (MPO) expression. MPO, expressed in foam cell macrophages, was recently shown to oxidize the ApoA-1 component of HDL, impairing ABCA-1 mediated cholesterol efflux. High levels of serum MPO correlate with increased risk of CAD events. Findings here show that statins strongly inhibit MPO mRNA expression in human and murine monocyte-macrophages. Suppression was reversed by downstream intermediates of HMG-CoA reductase, mevalonate, and geranylgeranylpyrophosphate, but not farnesylpyrophosphate. An inhibitor of geranylgeranyltransferase, GGTI-286, mimics the effects of statins, indicating geranylgeranylation is key to MPO expression. Reduction of MPO mRNA levels was observed in vivo in leukocytes from statin-fed mice, correlating with reductions in MPO protein and enzyme activity. These findings suggest that the pleiotropic protections afforded by statins may be due in part to suppression of MPO expression.

HMG-CoA reductase inhibitor protects against in vivo arterial thrombosis by augmenting platelet-derived nitric oxide release in rats

Acute coronary syndromes are caused by platelet-mediated thrombosis following rupture of a plaque. HMG-CoA reductase inhibitors (statins) reduce the incidence of events early after acute coronary syndromes, which are independent of its cholesterol-lowering effect. Accordingly, we investigated whether statins inhibit platelet-mediated arterial thrombus formation in vivo and, if so, the underlying mechanisms. Rats were divided into 4 groups. Group 1 was treated with the vehicle, whereas groups 2, 3, and 4 were treated with cerivastatin for 7 days (1, 2, and 5 mg/kg i.p., respectively). Cerivatatin did not change serum cholesterol levels. Carotid arterial thrombosis was created by perivascular FeCl3 delivery. Cerivastatin significantly prolonged the time to thrombotic occlusion of carotid artery. Cerivastatin significantly dose-dependently inhibited both ex vivo platelet P-selectin expression, a marker of platelet activation, and platelet aggregation. Cerivastatin significantly augmented platelet-derived nitric oxide (NO) release, and up-regulated platelet and endothelial nitric oxide synthase (NOS) mRNA expressions. N-nitro-L-arginine methylester abolished the effects of cerivastatin. This study demonstrates that in vivo administration of statin protects against platelet-mediated arterial thrombosis, possibly by augmenting platelet- and endothelium-derived NO releases via up-regulation of platelet and endothelial NOS.

Enhanced oxidative stress in neutrophils from hyperlipidemic guinea pig

Inhibitors of 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase are antilipidemic agents (statins) widely used for the prevention of cardiovascular diseases. Recent studies have suggested that the overall benefits of statin therapy cannot be accounted for solely by its antilipidemic effect. To obtain further insight into the mechanism of action of statins, we studied the effect of pitavastatin on the generation of reactive oxygen species (ROS) by peritoneal polymorphonuclear leukocytes (PMN) obtained from control and hyperlipidemic guinea pigs. Flow cytometric analysis revealed that the amount of ROS generated by PMN from the hyperlipidemic animals that had been administered a laurate-containing diet (LD) for 4 weeks was larger than that from the normal diet (ND) group (837% increase, ND; 82.17 arbitrary units, LD; 688.10 arbitrary units, P < 0.01, n = 6). Administration of pitavastatin to the LD group significantly decreased plasma levels of total cholesterol (TC) and low-density lipoprotein (LDL) with a reduction in ROS generation by PMN (19% decrease, LD control; 688.10 arbitrary units, LD + pitavastatin; 556.87 arbitrary units, P < 0.01, n = 6). Western blotting analysis revealed that the expression of protein kinase C alpha (PKC alpha) and betaI was higher in PMN from the LD group than in PMN from the ND group (PKC alpha; 74% increase, PKC betaI; 339% increase, P < 0.05, n = 4, respectively). Furthermore, expression of NADPH oxidase gp91phox in PMN from the LD group was higher than that in PMN from the ND group (18% increase, P < 0.05, n = 4). By administration of pitavastatin to the LD group, the expression of PKC alpha, betaI and gp91phox was suppressed compared with the control LD group (PKC alpha; 41% decrease, PKC beta; 28% decrease, gp91phox; 56% decrease, P < 0.05, n = 4, respectively). These results indicate that PMN from hyperlipidemic animals is associated with an accelerated respiratory burst of ROS by increasing the expression of PKC alpha, betaI and gp91phox, and pitavastatin inhibits this by suppressing the expression of those proteins.