Statins as anti-inflammatory agents

Alzheimer's disease, cholesterol, and statins: the junctions of important metabolic pathways

Recent years have seen a significant increase in published data supporting the positive effects of statins on neurodegenerative diseases, in particular on Alzheimer's disease. Statins show neuroprotective activity by a combination of different cellular and systemic mechanisms that are based on the inhibition of the biosynthesis of cholesterol and isoprenoid by-products. The promising results obtained in vivo and in epidemiological studies are generally not in accordance with those of placebo-controlled randomized clinical trials. Nevertheless, these results make statins valuable assets for disease prevention rather than therapeutic agents for use when disease symptoms are already displayed. Thus, the modulation of midlife cholesterol and/or statin administration prior to the appearance of dementia or cognitive impairment may have a better long-term outcome.

Statins and anti-inflammatory therapies for subarachnoid hemorrhage

OPINION STATEMENT

Aneurysmal subarachnoid hemorrhage (SAH) induces a potent inflammatory cascade that contributes to endothelial dysfunction, imbalance of vasoactive substances (excess endothelin, depletion of nitric oxide), and arterial vasospasm. This process results in delayed cerebral ischemia, a major cause of neurologic disability in those surviving the initial hemorrhage. The only therapy shown to be effective in improving neurologic outcomes after SAH is a calcium-channel antagonist, nimodipine (although it achieved this result without reducing vasospasm). A number of novel therapies have been explored to inhibit the development of vasospasm and reduce the burden of ischemia and cerebral infarction. Statins are promising candidates, as they block multiple aspects of the inflammatory pathway that contributes to ischemic brain injury. Early clinical trials have produced conflicting results, however, and the adoption of statins in clinical practice should await the results of larger, more definitive studies. Though endothelin-receptor antagonists showed promise in significantly reducing vasospasm in preliminary trials, their failure to improve clinical outcomes in phase 3 studies has been disappointing, highlighting the complex link between vasospasm and ischemia. Future directions in the quest to improve outcomes of patients with SAH may need to approach ischemia as a multifactorial process with inflammatory, vasoactive, and ionic/metabolic components.

Randomised clinical trial: simvastatin as adjuvant therapy improves significantly the Helicobacter pylori eradication rate--a placebo-controlled study

BACKGROUND

The eradication rate of Helicobacter pylori with standard treatments are decreasing worldwide.

AIM

To determine whether adding simvastatin as adjuvant to triple regimen in patients with H. pylori infection will improve the eradication rate.

METHODS

We conducted a double-blind, placebo-controlled, randomised clinical trial comparing a 7-day, triple eradication regimen consisting of two antibiotics (clarithromycin 500 mg and amoxicillin 1 g, all twice per day) plus a proton pump inhibitor (omeprazole 20 mg twice daily) supplemented with simvastatin 20 mg (CAO + S) or a comparable placebo (CAO + P). Both the simvastatin and the placebo were taken orally twice daily for 1 week in 113 patients with H. pylori infection. The presence of H. pylori was determined by positive rapid urease test and histology. Eradication was confirmed by ¹³C-urea breath test at least 1 month after treatment. Adverse effects were assessed by questionnaire.

RESULTS

A total of 113 patients underwent randomisation. Intention-to-treat analysis (ITT; n = 113) eradication rates were: CAO + S (86%; 95% CI: 78-92%), CAO + P (69%; 95% CI: 64-74%). Per protocol analysis (PP; n = 108) eradication rates were: CAO + S (91%; 95% CI: 84-94%), CAO + P (72%; 95% CI: 65-78%). Eradication rates were higher with CAO + S than CAO + P in PP and ITT (P = 0.03, P = 0.04 respectively). No differences were demonstrated between the two groups concerning compliance or adverse effects.

CONCLUSION

In this randomised clinical trial simvastatin as adjuvant to standard therapy improves significantly the H. pylori eradication rate.

Lipid-lowering agents in nonalcoholic fatty liver disease and steatohepatitis: human studies

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease which refers to the presence of hepatic steatosis without significant intake of alcohol. NAFLD is an asymptomatic disease that can progress to nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and hepatocellular carcinoma. NAFLD is currently the most common cause of incidental abnormal liver tests and elevated serum liver enzyme activities in the developed world. Obesity, diabetes, and other components of the metabolic syndrome are frequently associated with the NAFLD. The treatment of NAFLD focuses on life-style modifications. Statins, fibrates, and other lipid-lowering agents have been proposed as effective lipid-lowering treatments in patients with NAFLD/NASH. However, clinicians are concerned that hyperlipidemic patients with NAFLD/NASH who are treated with statins could develop transaminitis. We assessed the efficacy and safety of lipid-lowering agents for NAFLD/NASH by reviewing reports of human studies including pilot, prospective, preliminary, and post hoc analysis studies on online databases during the period of 1980 to December 2012. The results of studies provide compelling evidence that lipid-lowering agents are safe and efficacious in patients with NAFLD/NASH and that some of these agents can induce a reduction in the extent of the hepatic steatosis. Well-designed randomized controlled studies of adequate size and duration with histological endpoints are needed in order to establish a suitable lipid-lowering treatment for hyperlipidemic patients with NAFLD/NASH, and for nonhyperlipidemic patients with NAFLD/NASH with a high risk for cardiovascular disease.

Chronic administration of atorvastatin induced anti-convulsant effects in mice: the role of nitric oxide

Atorvastatin has neuroprotective effects, and there is some evidence that nitric oxide is involved in atorvastatin effects. In this study, we evaluated whether the nitrergic system is involved in the anticonvulsant effects of chronic atorvastatin administration. Intravenous and intraperitoneal pentylenetetrazol were used to induce seizures in mice. Chronic atorvastatin treatment significantly increased the seizure threshold which is induced by both intravenous and intraperitoneal pentylenetetrazol. Intraperitoneal pentylenetetrazol also decreased the incidence of tonic seizure and death in atorvastatin-treated groups. Chronic co-administration of a non-selective nitric oxide synthase inhibitor, l-NAME, or a selective inducible nitric oxide synthase inhibitor, aminoguanidine, with atorvastatin inhibited atorvastatin-induced anticonvulsant effects in intravenous model of pentylenetetrazol. Acute injection of l-NAME or aminoguanidine inhibited the anticonvulsant effects of atorvastatin in both models of intravenous- and intraperitoneal-pentylenetetrazol-induced seizures. In conclusion, we demonstrated that nitric oxide signaling probably through inducible nitric oxide synthase could be involved in the anticonvulsant effects of atorvastatin.

Simvastatin ointment, a new treatment for skin inflammatory conditions

BACKGROUND

Statins represent a class of drugs that effectively lowers cholesterol, however they also possess pleiotropic effects, like promotion of angiogenesis, prevention of bone loss, immunomodulatory and anti-inflammatory effects.

OBJECTIVES

Thus, the aim of this study was to investigate the activity of simvastatin topically applied in mice in acute and chronic skin inflammation models.

METHODS

Skin inflammation was induced in mice ears by topical application of 12-O-tetradecanoylphorbol acetate (TPA). In the acute model, ear oedema was measured by the increase of ear thickness 6h after TPA (2.5μg/ear). The chronic inflammatory process was induced by multiple applications of TPA (2.0μg/ear) for nine alternate days, and the oedema was measured daily as the increase in ear thickness.

RESULTS

Topical treatment was applied immediately after TPA in acute model or started at 5th day of chronic experiment. For acute model treatment was simvastatin (0.24, 0.71 and 2.40μM), dexamethasone (0.13μM), both in acetone or vehicle alone (acetone). In chronic model simvastatin (1% and 3%) and dexamethasone (0.5%) were incorporated in ointment preparations, and a group received ointment alone (vehicle). Samples of ear tissue (6mm) were taken from acute and chronic models, weighted and prepared for histological analysis and myeloperoxidase (MPO) enzymatic activity evaluation. Application of simvastatin in acetone reduced the ear oedema after a single TPA application in a dose dependent manner [ID(50) of 0.47 (0.22-1.13) μM], and the MPO enzymatic activity up to 61±10%. Also, both simvastatin ointment preparations 1% and 3% reduced acute TPA-induced ear oedema in 55±7% and 65±8%, respectively. In the chronic model, simvastatin ointment 1% was able to reduce ear oedema (25±3%) and ear weight (10±1%), though 3% formulation augmented both parameters. Histological analysis revealed a reduction of swelling and leukocyte migration in the acute model for both the formulations of simvastatin (1% and 3%), while in chronic model simvastatin 1% decreased ear swelling and epidermal thickness, but simvastatin 3% increased both parameters.

CONCLUSION

The results confirm the anti-inflammatory activity of simvastatin when applied topically in both acute and chronic models of skin inflammation. Besides, the formulation of simvastatin ointment 1% shows to be a very effective formulation for a chronic usage.

Long-term efficacy of upstream therapy with lipophilic or hydrophilic statins on antiarrhythmic drugs in patients with paroxysmal atrial fibrillation: comparison between atorvastatin and pravastatin

There is little information available on the benefits of selection of statins as upstream therapy for the prevention of paroxysmal atrial fibrillation (AF). We compared the efficacy and safety of atorvastatin (A-group, n = 43) and pravastatin (P-group, n = 41) as upstream therapy in patients with paroxysmal AF and dyslipidemia. A total of 84 patients (45 men, mean age, 66 ± 9 years, mean follow-up, 49 ± 32 months) were retrospectively assigned to receive atorvastatin (n = 41;10 mg/day) or pravastatin (n = 43 ; 10 mg/day). Survival rates free from AF recurrence at 1, 6, 12, and 24 months were 93%, 74%, 60%, and 53% in A-group, and 88%, 49%, 37%, and 29%, respectively, in P-group (P = 0.029, A-group versus P-group). Survival rates free from conversion to permanent AF at 12, 36, 60, and 90 months were 100%, 100%, 98%, and 95% in A-group, and 100%, 95%, 88%, and 83%, respectively, in P-group (P = 0.063, A-group versus P-group). Using a logistic regression model, atorvastatin was found to be associated with a significantly reduced risk of AF recurrence in comparison to pravastatin (unadjusted odds ratio [OR] = 0.27, 95% confidence interval 0.11-0.68, P = 0.005). This association remained significant after adjustment for potentially confounding variables (OR = 0.26, 95% CI 0.08-0.86, P = 0.027). Using a logistic regression model, atorvastatin was not associated with a significantly reduced risk of converting to permanent AF in comparison to pravastatin (unadjusted OR = 0.29, 95% CI 0.05-1.50, P = 0.138), but this association did show a significant difference after adjustment for potentially confounding variables in a multivariate model (OR = 0.08, 95% CI 0.06-0.96, P = 0.046). Adverse effects requiring discontinuation of statins were observed in 1 case (2%, myalgia) in A-group, and 1 case (2%, elevation in CPK level ≥ 500 IU/L) in P-group, respectively (P = NS, A-group versus P-group). Atorvastatin, a lipophilic statin, was considered to be more effective in preventing recurrence of paroxysmal AF and conversion to permanent AF than pravastatin, a hydrophilic statin.

Atorvastatin ameliorates tissue damage of obstructed ureter in rats

AIMS

To investigate the effects of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor on the tissue damage and fibrosis of obstructed ureters, 80 rats were studied.

MAIN METHODS

Atorvastatin, a HMG-CoA reductase inhibitor, was administered to 40 rats at the dose of 20 mg/kg per day 1day before unilateral ligation of ureters and every day thereafter. The other rats served as controls. Eight rats from each group were sacrificed for examination on days 7, 14, 21, 28 and 42 after ligation, respectively. The expressions of transforming growth factor-β1 (TGF-β1), Interleukine-1β (IL-1β), Interleukine-6 (IL-6), tumor necrosis factor-alpha (TNF-α), proliferation cell nuclear antigen (PCNA), and the apoptotic cells in the ureteric smooth muscle were examined.

KEY FINDINGS

Hydroureter and fibrosis of the muscle layer became progressively aggravated in the ligated ureters of the atorvastatin-treated group and control group. The severities of hydroureter and muscle layer fibrosis in the ligated ureters of the treated group were significantly less than in the control group. The atorvastatin administration also decreased the expression of TGF-β1, IL-1β, IL-6, TNF-α, PCNA and the labeling index of apoptotic cells in the smooth muscle layer of ligated ureters in the treated group.

SIGNIFICANCE

We concluded that atorvastatin might ameliorate the tissue damage of obstructed ureters, at least partially, via the inhibition on TGF-β1) expression and by diminishing the effects of pro-inflammatory cytokines.

The impact of prior long-term versus short-term statin use on the mortality of bacteraemic patients

BACKGROUND

The aim of this investigation was to assess the effect of prior statin use on the 30-day in-hospital mortality among bacteraemic patients and to determine the impact of long-term versus short-term statin use on the mortality of bacteraemic patients.

PATIENTS AND METHODS

A retrospective study of 342 bacteraemic patients who presented to the emergency department (ED) within a period of 7 years was undertaken. Twenty-three patients did not meet the inclusion criteria. The remaining 319 patients were divided into three groups according to statin use and duration of therapy prior to the bacteraemic episode: group 1 (n = 123) had long-term statin use ≥ 12 weeks, group 2 (n = 35) had short-term statin use < 12 weeks, and group 3 (n = 161) had no statin use.

RESULTS

The overall 30-day in-hospital all-cause mortality of patients with statins was lower than patients without statin therapy (13 vs. 24%, p = 0.001). The mortality rate in group 1 was lower than in group 2 (11 vs. 17%, p = 0.04). After adjusting for confounding variables, the results of a multiple Cox regression analysis revealed that the absence of statin use (hazard ratio [HR] = 2.98; 95% confidence interval [CI] 1.59-5.56, p = 0.001) was associated with increased 30-day in-hospital all-cause mortality in bacteraemic patients.

CONCLUSIONS

Statins reduce the 30-day in-hospital all-cause mortality of bacteraemic patients. Long-term statin use prior to the bacteraemia improves the survival of bacteraemic patients more than short-term statin use.

Association between statin therapy and outcomes in critically ill patients: a nested cohort study

Background

The effect of statin therapy on mortality in critically ill patients is controversial, with some studies suggesting a benefit and others suggesting no benefit or even potential harm. The objective of this study was to evaluate the association between statin therapy during intensive care unit (ICU) admission and all-cause mortality in critically ill patients.

Methods

This was a nested cohort study within two randomised controlled trials conducted in a tertiary care ICU. All 763 patients who participated in the two trials were included in this study. Of these, 107 patients (14%) received statins during their ICU stay. The primary endpoint was all-cause ICU and hospital mortality. Secondary endpoints included the development of sepsis and severe sepsis during the ICU stay, the ICU length of stay, the hospital length of stay, and the duration of mechanical ventilation. Multivariate logistic regression was used to adjust for clinically and statistically relevant variables.

Results

Statin therapy was associated with a reduction in hospital mortality (adjusted odds ratio [aOR] = 0.60, 95% confidence interval [CI] 0.36-0.99). Statin therapy was associated with lower hospital mortality in the following groups: patients >58 years of age (aOR = 0.58, 95% CI 0.35-0.97), those with an acute physiology and chronic health evaluation (APACHE II) score >22 (aOR = 0.54, 95% CI 0.31-0.96), diabetic patients (aOR = 0.52, 95% CI 0.30-0.90), patients on vasopressor therapy (aOR = 0.53, 95% CI 0.29-0.97), those admitted with severe sepsis (aOR = 0.22, 95% CI 0.07-0.66), patients with creatinine ≤100 μmol/L (aOR = 0.14, 95% CI 0.04-0.51), and patients with GCS ≤9 (aOR = 0.34, 95% CI 0.17-0.71). When stratified by statin dose, the mortality reduction was mainly observed with statin equipotent doses ≥40 mg of simvastatin (aOR = 0.53, 95% CI 0.28-1.00). Mortality reduction was observed with simvastatin (aOR = 0.37, 95% CI 0.17-0.81) but not with atorvastatin (aOR = 0.80, 95% CI 0.84-1.46). Statin therapy was not associated with a difference in any of the secondary outcomes.

Conclusion

Statin therapy during ICU stay was associated with a reduction in all-cause hospital mortality. This association was especially noted in high-risk subgroups. This potential benefit needs to be validated in a randomised, controlled trial.

Effects of simvastatin, atorvastatin, ezetimibe, and ezetimibe + simvastatin combination on the inflammatory process and on the liver metabolic changes of arthritic rats

In this study, simvastatin, atorvastatin, ezetimibe, and ezetimibe + simvastatin combination were administered to arthritic rats, first to determine their effects on the inflammatory response, employing a low-dose adjuvant-induced arthritis model in rats. Arthritis was induced by the subcutaneous injection of a suspension of Mycobacterium tuberculosis (100 μg) in mineral oil [complete Freund's adjuvant used (CFA)] into the plantar surface of the hind paws. Simvastatin(40 mg/kg), atorvastatin(10 mg/kg), ezetimibe(10 mg/kg), ezetimibe(10 mg/kg) + simvastatin(20 mg/kg or 40 mg/kg) were given intragastrically and the treatment began on the day of CFA injection and continued daily up to the 28th day after arthritis induction. The ezetimibe + simvastatin combination was more effective in reducing the inflammatory response in arthritic rats than in atorvastatin, simvastatin, or ezetimibe monotherapy. The observed effect seems to be cholesterol-independent as there were no changes in plasma cholesterol levels. In spite of the benefits on joint lesions, treatment with ezetimibe + simvastatin combination caused a marked increment in liver, kidneys, spleen size, and plasma transaminases activities. Therefore, animals treated with the ezetimibe(10 mg/kg) + simvastatin(40 mg/kg) combination were also submitted to liver perfusion experiments. In this regard, ezetimibe + simvastatin did not improve the liver metabolic alterations seen in control arthritic rats, on the contrary, a worsening was observed in liver production of glucose from alanine, as well as in oxygen uptake. All of these metabolic changes appear to be induced by treatment with ezetimibe + simvastatin combination, as the same metabolic effects were observed in normal and treated arthritic animals.

Genetic variability within the cholesterol lowering pathway and the effectiveness of statins in reducing the risk of MI

Genetic variability has been shown to affect statin responsiveness. Participants from the Utrecht Cardiovascular Pharmacogenetics (UCP) studies were enrolled from a population-based registry of pharmacy records linked to hospital discharge records (PHARMO) to investigate tagging SNPs within candidate genes involved in the cholesterol lowering pathway for modification of the effectiveness of statins in reducing the risk of myocardial infarction (MI). Patients who received a prescription for an antihypertensive drug and/or had hypercholesterolemia were selected from the PHARMO database. We designed a nested case-control study in which cases were hospitalized for MI and controls were not. Patients were contacted through their community pharmacies. For this study, only hypercholesterolemic participants were selected. Logistic regression analysis was used to investigate pharmacogenetic interactions. The Heart and Vascular Health Study (HVH) was used to replicate findings from UCP. The study population included 668 cases and 1217 controls. We selected 231 SNPs of which 209 SNPs in 27 genes passed quality control. Ten SNPs in eight genes were found to influence the effectiveness of statins in UCP, of which the most significant interaction was found with SCARB1 rs4765615. Other genes that reached statistical significance (p<0.05) included two SNPs in PCSK9 (rs10888896 and rs505151 (E670G)), two SNPs in ABCG5 (rs4245786 and rs1864815), LIPC rs16940379, ABCA1 rs4149264, PPARG rs2972164, LRP1 rs715948, and SOAT1 rs2493121. None of the total of 5 SNPs that were available for replication in HVH reached statistical significance. In conclusion, ten SNPs were found to modify the effectiveness of statins in reducing the risk of MI in the UCP study. Five were also tested in the HVH study, but no interactions reached statistical significance.

Lovastatin inhibits T-cell proliferation while preserving the cytolytic function of EBV, CMV, and MART-1-specific CTLs

Statin treatment has been shown to reduce graft-versus-host disease while preserving graft-versus-tumor effect in allogeneic stem cell transplantation. Herein, we investigated whether lovastatin treatment affects the function of human cytolytic T lymphocytes (CTLs). Upon T-cell receptor stimulation, lovastatin significantly inhibited the proliferation of both CD4+ and CD8+ T cells from healthy donors whereas their intracellular cytokine production including interferon-γ and tumor necrosis factor-α remained the same with a slight decrease of interleukin-2. Moreover, the specific lysis of target cells by CTL lines derived from patients and normal donors specific for Epstein-Barr virus-encoded antigen latent membrane protein-2 or cytomegalovirus-encoded antigen pp65 was uncompromised in the presence of lovastatin. In addition, we evaluated the effect of lovastatin on the proliferation and effector function of the CD8+ tumor-infiltrating lymphocytes (TILs) derived from melanoma patients specific for MART-1 antigen. Lovastatin significantly reduced the expansion of antigen-specific TILs upon MART-1 stimulation. However, the effector function of TILs, including the specific lysis of target cells and secretion of cytokine interferon-γ, remained intact with lovastatin treatment. Taken together, these data demonstrated that lovastatin inhibits the proliferation of Epstein-Barr virus, cytomegalovirus, and MART-1-specific CTLs without affecting cytolytic capacity. The differential effect of lovastatin on the proliferation versus cytotoxicity of CTLs might shed some light on elucidating the possible mechanisms of graft-versus-host disease and graft-versus-tumor effect elicited by alloimmune responses.

Topical anti-inflammatory effect of hypocholesterolaemic drugs

OBJECTIVES

The topical anti-inflammatory effect of simvastatin, atorvastatin, pravastatin, ezetimibe and combined ezetimibe + simvastatin was investigated, using the croton oil model of ear oedema in mice.

METHODS

Simvastatin, atorvastatin, pravastatin, ezetimibe and ezetimibe + simvastatin combination (dissolved in 20 µl of 70% acetone) were topically applied simultaneously with croton oil (200 µg/ear, dissolved in 20 µl of 70% acetone) at the inner surface of each ear. Ear oedema and myeloperoxidase activity, indicative of polymorphonuclear cell migration, were assessed 6 h after inflammatory stimuli.

KEY FINDINGS

It was found that statins can act as topical anti-inflammatories, but the pharmacological effect is dependent on statin polarity. At 0.3 mg/ear inhibition of ear oedema was 79%, 67% and 40% for simvastatin, atorvastatin and pravastatin, respectively. Simvastatin and atorvastatin also remarkably diminished myeloperoxidase activity, even at low concentrations (0.03 mg/ear). Pravastatin, the most polar statin, however, did not cause any reduction in ear oedema or myeloperoxidase activity at low doses. The order of topical anti-inflammatory activity was pravastatin < < < atorvastatin ≤ simvastatin. Ezetimibe, another hypocholesterolaemic drug, also presented anti-inflammatory effects, inhibiting ear oedema by 64% at 0.3 mg/ear. However, when used in combination with simvastatin, no further beneficial effect was observed.

CONCLUSIONS

These results consistently support current evidence showing that statins can be used for treatment of dermatological disorders. Polarity of the molecule, however, is a factor that should be considered before recommending use.

Statins: a role in infected critically ill patients?

Terblanche and colleagues add to the ongoing controversy over the role, if any, for statins in patients with sepsis. The authors note that statins fail to prevent progression to organ dysfunction in critically ill patients. However, like most publications, the study is retrospective and stimulates the controversy but fails to resolve it. The time has come for robust randomized controlled clinical trials.

Statin or fibrate chronic treatment modifies the proteomic profile of rat skeletal muscle

Statins and fibrates can cause myopathy. To further understand the causes of the damage we performed a proteome analysis in fast-twitch skeletal muscle of rats chronically treated with different hypolipidemic drugs. The proteomic maps were obtained from extensor digitorum longus (EDL) muscles of rats treated for 2-months with 10mg/kg atorvastatin, 20 mg/kg fluvastatin, 60 mg/kg fenofibrate and control rats. The proteins differentially expressed were identified by mass spectrometry and further analyzed by immunoblot analysis. We found a significant modification in 40 out of 417 total spots analyzed in atorvastatin treated rats, 15 out of 436 total spots in fluvastatin treated rats and 21 out of 439 total spots in fenofibrate treated rats in comparison to controls. All treatments induced a general tendency to a down-regulation of protein expression; in particular, atorvastatin affected the protein pattern more extensively with respect to the other treatments. Energy production systems, both oxidative and glycolytic enzymes and creatine kinase, were down-regulated following atorvastatin administration, whereas fenofibrate determined mostly alterations in glycolytic enzymes and creatine kinase, oxidative enzymes being relatively spared. Additionally, all treatments resulted in some modifications of proteins involved in cellular defenses against oxidative stress, such as heat shock proteins, and of myofibrillar proteins. These results were confirmed by immunoblot analysis. In conclusions, the proteomic analysis showed that either statin or fibrate administration can modify the expression of proteins essential for skeletal muscle function suggesting potential mechanisms for statin myopathy.

Long-term statin therapy affects the severity of chronic gastritis

BACKGROUND

Helicobacter pylori (H. pylori) is a major cause of chronic gastritis. Statins have several pleotropic effects and their mechanisms of action could be related to anti-inflammatory, antioxidants, and immunomodulatory effects.

AIM

To determine whether statin therapy affects the severity of chronic gastritis.

MATERIALS AND METHODS

In a retrospective study, we evaluated 516 patients who underwent upper endoscopy. One-hundred and ninety-eight patients had chronic gastritis, The 198 patients with chronic gastritis were divided into two groups: group 1 comprised patients with a history of statin therapy and group 2 comprised patients with no history of statin therapy. Both groups were compared for age, gender, body mass index (BMI), underlying diseases, drug therapy, alcohol consumption, smoking and the serum levels of C-reactive protein (CRP). The presence of H. pylori was determined by gastric biopsy and rapid urease test. The grade and severity of gastritis were assessed using the updated Sydney classification system in two gastric biopsy specimens that were taken from each participant in each group.

RESULTS

Of the 198 patients with chronic gastritis, 49% of the patients had mild gastritis and 51% had moderate to severe gastritis. From the results of a multiple logistic regression analysis after adjusting for confounding variables that included age, gender, and BMI, we found that elevated serum CRP levels (odds ratio (OR) 2.33; 95% confidence interval (CI) = 0.8-2.6, p = .02), H. pylori (OR 1.99; CI 0.14-2.4, p = .04), and the use of statin (OR 1.64; CI = 0.71-1.77, p = .05) independently predict the severity of chronic gastritis.

CONCLUSION

Long-standing statin therapy may reduce the severity of chronic gastritis. Mild increased CRP levels in absence of obvious source can predict the severity of chronic gastritis. Further researches are needed to assess the effect of statin in chronic gastritis.

Differential adaptation of human gut microbiota to bariatric surgery-induced weight loss: links with metabolic and low-grade inflammation markers

OBJECTIVE

Obesity alters gut microbiota ecology and associates with low-grade inflammation in humans. Roux-en-Y gastric bypass (RYGB) surgery is one of the most efficient procedures for the treatment of morbid obesity resulting in drastic weight loss and improvement of metabolic and inflammatory status. We analyzed the impact of RYGB on the modifications of gut microbiota and examined links with adaptations associated with this procedure.

RESEARCH DESIGN AND METHODS

Gut microbiota was profiled from fecal samples by real-time quantitative PCR in 13 lean control subjects and in 30 obese individuals (with seven type 2 diabetics) explored before (M0), 3 months (M3), and 6 months (M6) after RYGB.

RESULTS

Four major findings are highlighted: 1) Bacteroides/Prevotella group was lower in obese subjects than in control subjects at M0 and increased at M3. It was negatively correlated with corpulence, but the correlation depended highly on caloric intake; 2) Escherichia coli species increased at M3 and inversely correlated with fat mass and leptin levels independently of changes in food intake; 3) lactic acid bacteria including Lactobacillus/Leuconostoc/Pediococcus group and Bifidobacterium genus decreased at M3; and 4) Faecalibacterium prausnitzii species was lower in subjects with diabetes and associated negatively with inflammatory markers at M0 and throughout the follow-up after surgery independently of changes in food intake.

CONCLUSIONS

These results suggest that components of the dominant gut microbiota rapidly adapt in a starvation-like situation induced by RYGB while the F. prausnitzii species is directly linked to the reduction in low-grade inflammation state in obesity and diabetes independently of calorie intake.

Impact of therapy with statins, beta-blockers and angiotensin-converting enzyme inhibitors on plasma myeloperoxidase in patients with coronary artery disease

PURPOSE

The present study investigated whether therapy with statins, beta-blockers and angiotensin-converting enzyme (ACE) inhibitors on admission affects the plasma level of myeloperoxidase (MPO) in patients with coronary artery disease (CAD).

METHODS

This study included a consecutive series of 680 patients with angiographically confirmed CAD: 382 patients with stable CAD, 107 patients with unstable angina and 191 patients with ST-segment elevation acute myocardial infarction. Blood samples for MPO measurement were taken before angiography prior to heparin administration.

RESULTS

On admission, 316 patients were receiving statins, 432 patients were receiving beta-blockers and 354 patients were receiving ACE inhibitors. MPO level was: 65.5 [48.8-101.6] μg/L among patients on statin therapy versus 86.7 [56.0-159.9] μg/L among patients without statin therapy (P < 0.001); 68.1 [50.1-105.1] μg/L among patients on beta-blocker therapy versus 97.3 [56.0-181.9] μg/L among patients without beta-blocker therapy (P < 0.001) and 65.5 [49.2-102.0] μg/L among patients receiving ACE inhibitors versus 92.0 [56.1-171.1] μg/L among patients not receiving ACE inhibitors on admission (P < 0.001). The MPO-lowering effect of these drugs was observed only in patients with acute coronary syndrome but not in patients with stable CAD. The multivariable analysis, adjusting for cardiovascular risk factors, clinical variables and concomitant therapy identified beta-blockers on admission as an independent correlate of lower MPO levels (P = 0.016).

CONCLUSIONS

In patients with symptomatic CAD, beta-blocker therapy on admission was independently associated with lower levels of plasma MPO. Pre-admission therapy with statins, beta-blockers or ACE inhibitors reduced MPO levels in patients with acute coronary syndromes, but not in patients with stable CAD.

Attenuation of astrogliosis and modulation of endothelial growth factor receptor in lipid rafts by simvastatin after traumatic brain injury

OBJECT

The authors' previous studies have demonstrated that simvastatin treatment promotes neuronal survival and reduces inflammatory cytokine release from astrocytes after traumatic brain injury (TBI) in rats. Since reactive astrocytes produce inflammation mediators, in the current study the authors investigated the effect of simvastatin on astrocyte activation after TBI and its underlying signaling mechanisms.

METHODS

Saline or simvastatin (1 mg/kg) was orally administered to rats starting at Day 1 after TBI and then daily for 14 days. Rats were killed at 1, 3, 7, and 14 days after treatment. Brain sections and tissues were prepared for immunohistochemical staining and Western blot analysis, respectively. Cultured astrocytes were subjected to oxygen-glucose deprivation (OGD) and followed by immunocytochemical staining with glial fibrillary acidic protein/caveolin-1 and Western blot analysis. Lipid rafts were isolated from the cell lysate and Western blotting was carried out to detect the changes in epidermal growth factor receptor (EGFR) expression and phosphorylation in the lipid rafts.

RESULTS

Simvastatin significantly promoted neuronal survival after TBI and attenuated activation of astrocytes. Simvastatin modified the caveolin-1 expression in lipid rafts in astrocyte cell membrane, suppressed the phosphorylation of EGFR in lipid rafts of astrocytes after OGD, and inhibited the OGD-induced interleukin-1 production.

CONCLUSIONS

These data suggest that simvastatin reduces reactive astrogliosis and rescues neuronal cells after TBI. These beneficial effects of simvastatin may be mediated by inhibiting astrocyte activation after TBI through modifying the caveolin-1 expression in lipid rafts and the subsequent modulation of EGFR phosphorylation in lipid rafts.

Blocking LFA-1 activation with lovastatin prevents graft-versus-host disease in mouse bone marrow transplantation

Graft-versus-host disease (GVHD) following bone marrow transplantation (BMT) is mediated by alloreactive donor T lymphocytes. Migration and activation of donor-derived T lymphocytes play critical roles in the development of GVHD. Leukocyte function-associated antigen-1 (LFA-1) regulates T cell adhesion and activation. We previously demonstrated that the I-domain, the ligand-binding site of LFA-1, changes from the low-affinity state to the high-affinity state on LFA-1 activation. Therapeutic antagonists, such as statins, inhibit LFA-1 activation and immune responses by modulating the affinity state of the LFA-1 I-domain. In the present study, we report that lovastatin blocked mouse T cell adhesion, proliferation, and cytokine production in vitro. Furthermore, blocking LFA-1 in the low-affinity state with lovastatin reduced the mortality and morbidity associated with GVHD in a murine BMT model. Specifically, lovastatin prevented T lymphocytes from homing to lymph nodes and Peyer's patches during the GVHD initiation phase and after donor lymphocyte infusion (DLI) after the establishment of GVHD. In addition, treatment with lovastatin impaired donor-derived T cell proliferation in vivo. Taken together, these results indicate the important role of lovastatin in the treatment of GVHD.

Effects of the combination with alpha-tricalcium phosphate and simvastatin on bone regeneration

BACKGROUND

Although local application of statins stimulates bone formation, high dose of simvastatin induces inflammation.

OBJECTIVE

A study was conducted to test the hypothesis that maximum bone regeneration with less inflammation would be achieved by combining an optimal dose of simvastatin with alpha-tricalcium phosphate (alpha-TCP), which is an osteoconductive biomaterial capable of releasing the drug gradually.

MATERIAL AND METHODS

Bilateral 5-mm-diameter calvarial defects were created in adult Wistar rats and filled with preparations of different doses of simvastatin (0, 0.01, 0.1, 0.25 and 0.5 mg) combined with alpha-TCP particles or left empty. The animals were sacrificed at 2, 4 and 8 weeks and analyzed radiologically and histologically. Half of the animals of 4 and 8 weeks were labeled with fluorescence dyes and histomorphometrically analyzed.

RESULTS

Simvastatin doses of 0.25 and 0.5 mg caused inflammation of the soft tissue at the graft site whereas control and other doses did not. The micro-CT analysis revealed that the alpha-TCP with 0.1 mg simvastatin (TCP-0.1) group yielded significantly higher bone volumes than untreated control group at all three time points (249%, 227% and 266% at 2, 4 and 8 weeks, respectively). The percentage of defect closure, bone mineral content and bone mineral density were also higher in the TCP-0.1 group than in the other groups.

CONCLUSION

When combined with alpha-TCP particles, 0.1 mg simvastatin is the optimal dose for stimulation of the maximum bone regeneration in rat calvarial defects without inducing inflammation and it could be applied as an effective bone graft material.

SOCS1 and SOCS3 in the control of CNS immunity

In the decade following their initial discovery, the suppressor of cytokine signaling (SOCS) proteins have been studied for their potential use as immunomodulators in disease. SOCS proteins, especially SOCS1 and SOCS3, are expressed by immune cells and cells of the central nervous system (CNS) and have the potential to impact immune processes within the CNS, including inflammatory cytokine and chemokine production, activation of microglia, macrophages and astrocytes, immune cell infiltration and autoimmunity. We describe CNS-relevant in vitro and in vivo studies that have examined the function of SOCS1 or SOCS3 under various neuroinflammatory or neuropathological conditions, including exposure of CNS cells to inflammatory cytokines or bacterial infection, demyelinating insults, stroke, spinal cord injury, multiple sclerosis and glioblastoma multiforme.

High-dose lovastatin for acute ischemic stroke: results of the phase I dose escalation neuroprotection with statin therapy for acute recovery trial (NeuSTART)

BACKGROUND

Hydroxymethylglutaryl coenzyme A reductase inhibitors ('statins') reduce the neuronal injury in dose-dependent fashion in rodent stroke models. We sought to determine whether lovastatin at doses above those currently approved can be administered safely within 24 h after an acute ischemic stroke.

METHODS

We conducted a phase 1B dose-finding study using an adaptive design novel to stroke trials, the continual reassessment method, to find the highest tolerated dose of lovastatin. Planned doses were 1, 3, 6, 8 and 10 mg/kg/day for 3 days. The primary safety outcomes were myotoxicity and hepatotoxicity. The model was calibrated to select a dose causing 7-13% toxicity.

RESULTS

We enrolled 33 patients (16 men/17 women, age range 23-82 years). Three patients were treated at 1 mg/kg, 10 at 3 mg/kg, 12 at 6 mg/kg, and 8 at 8 mg/kg. Thirty of the 33 patients (90.9%) completed at least 11 of 12 doses. Two patients at the 6-mg/kg dose level experienced transient mild elevations in transaminases without clinical sequelae. After an initial dose reduction, the dose was re-escalated to 8 mg/kg, and no further patients reached safety outcomes. No clinical liver disease, myopathy, or creatine phosphokinase elevations occurred. The final model-based toxicity at 8 mg/kg was 13%; no patient was treated at 10 mg/kg.

CONCLUSIONS

Lovastatin at doses above those currently approved by the Food and Drug Administration is feasible for 3 days after an acute ischemic stroke and the maximum tolerated dose is estimated to be 8 mg/kg/day. Further randomized studies are warranted to confirm its safety and to demonstrate its efficacy in improving functional outcomes after stroke.

Simvastatin attenuates hepatic sensitization to lipopolysaccharide after partial hepatectomy

BACKGROUND

Hepatic resection may be curative in patients with hepatobiliary malignancies but excessive loss of liver volume may cause hepatic dysfunction and increase susceptibility to subsequent postoperative infections and sepsis. Herein, we hypothesized that pretreatment with simvastatin may protect against lipopolysaccharide (LPS)-induced liver damage after partial hepatectomy.

MATERIALS AND METHODS

Male C57Bl/6 mice underwent 68% hepatectomy and exposed to LPS after 24h. Animals were pretreated with simvastatin (0.02 and 0.2mg/kg). Serum alanine aminotransferase (ALT) and tumor necrosis factor-alpha (TNF-alpha) as well as leukocyte infiltration and hepatocyte apoptosis were examined 6h after LPS challenge. An in vitro endothelial cell adhesion assay was used to study the mechanisms of simvastatin on leukocyte adhesion and the role of P-selectin and lymphocyte function antigen-1 (LFA-1).

RESULTS

Partial hepatectomy increased the sensitivity of the remnant liver tissue to LPS-provoked tissue injury. Simvastatin pretreatment reduced the LPS-induced increase in serum levels of ALT by 65% in hepatectomized animals. Moreover, simvastatin decreased leukocyte infiltration and hepatocyte apoptosis in the liver remnant of endotoxemic mice. LPS-provoked serum levels of TNF-alpha were decreased by 83% in hepatectomized animals treated with simvastatin. TNF-alpha-induced leukocyte adhesion as well as P-selectin expression in endothelial cells and LFA-1 function were inhibited by simvastatin in vitro.

CONCLUSIONS

These novels findings demonstrate that simvastatin protects the remnant liver against endotoxemic injury following major hepatectomy. Thus, simvastatin reduced LPS-induced leukocyte recruitment and hepatocyte apoptosis in the liver remnant. One key mechanism appears to be related to the inhibition of TNF-alpha formation and function (P-selectin expression) as well as to direct actions on LFA-1 function. Thus, simvastatin may represent a novel therapeutic approach to prevent septic liver damage after partial liver resection.

Tracing the origins of postoperative atrial fibrillation: the concept of oxidative stress-mediated myocardial injury phenomenon

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia associated with coronary artery surgery and is an important factor contributing to postoperative morbidity and mortality. Recently, there is growing evidence that dysregulation of the oxidant-antioxidant balance, inflammatory factors and discordant alteration of energy metabolites may play a significant role in its pathogenesis.

DESIGN

We evaluated the link between postoperative atrial fibrillation with inflammatory factors and oxidative stress.

METHODS

We searched all databases in Medline, Pubmed, ISI, the Cochrane database, and Embase. We identified more than 100 trials, multiple metaanalyses, and three sets of practice guidelines for the prevention of PAF in cardiac surgery.

RESULTS

Mechanisms of postoperative AF are likely to be multifactorial and are influenced by preoperative, intraoperative and postoperative factors including a genetic basis. Electrical remodelling is thought to be related to the generation of reactive oxidant species and inflammatory factors during the ischemia-reperfusion phase of cardiac surgery. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase was found to be the primary source of superoxide within the human atrial myocardium (in patients in sinus rhythm and in those with AF) and linked with paroxysmal and chronic AF. Reactive oxidant species cause lipid peroxidation, breakdown of cell membrane, decreased mitochondrial function, calcium overload and apoptosis. This affect was shown to be reversed by exogenous nitric oxide/donors (sodium nitroprusside). Inflammatory factors such as the rise in white blood cell count, C-reactive proteins were implicated in the pathogenesis of AF. In contrast, new evidence identifies statins as having both antioxidant and anti-inflammatory properties and that their use reduces the incidence of postoperative AF (57% in the control vs. 35% in the atorvastatin group). Other antiinflammatory strategies include steroids with one study showing postoperative AF occurred in 21% in the steroid group compared with 51% in the placebo group although their use resulted in an increase in other complications. The mainstay of therapy however, remains to be beta-blockers alone which impart a modest influence on overall rates of AF with a reduction from 33.7 to 16.9% (OR: 0.37, 95% CI: 0.29-0.48). Angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers has been shown in one study to reduce the risk of developing new-onset AF by nearly 50%, although this has not been adequately evaluated in cardiac surgery.

CONCLUSION

Inflammatory factors and oxidative stress play a major role in the pathogenesis of postoperative AF. This review provides an analysis of current evidence in support of efforts directed at antiinflammatory and antioxidant agents as interventions.

[Radiotherapy: what therapeutic orientations against the digestive aftereffects?]

Despite constant progress in radiotherapy techniques such as tumour imaging and cartography, techniques of radiation delivery or fractionation schedules, damage to normal gastro-intestinal tissues is inevitably associated with radiation therapy of pelvic tumours. Acute radiation enteritis concerns 80% of patients. It is related to stem cell loss, default in epithelial regenerating capacity and inflammation-induced mucosal dystrophy and ulceration. Chronic injury may develop in 5 to 10% of patients and is characterized by intestinal wall fibrosis resulting from an exaggerated scarring process, chronic inflammation and tissue necrosis. Research in mechanistic processes of normal tissue damage paved the way for new therapeutic approaches to emerge. These new targets include mucosal regeneration, reduction of vascular activation, inflammation and thrombosis, and fight against mesenchymal cells sustained activation. Effective strategies are multiple on preclinical models, but numerous efforts have to be made to achieve the complicated goal of protection of normal tissues from the side effects of radiation therapy.

Myeloid cells in atherosclerosis: initiators and decision shapers

Chronic inflammation is the underlying pathophysiological mechanism of atherosclerosis. Prominent suspects being involved in atherosclerosis are lymphocytes, platelets, and endothelial cells. However, recent advances suggest a potent role for myeloid leukocytes, specifically monocyte subsets, polymorphonuclear leukocytes, and mast cells. These three cell types are not just rapidly recruited or already reside in the vascular wall but also initiate and perpetuate core mechanisms in plaque formation and destabilization. Dendritic cell subsets as well as endothelial and smooth muscle progenitor cells may further emerge as important regulators of atheroprogression. To stimulate further investigations about the contribution of these myeloid cells, we highlight the current mechanistic understanding by which these cells tune atherosclerosis.

Statins and fenofibrate affect skeletal muscle chloride conductance in rats by differently impairing ClC-1 channel regulation and expression

BACKGROUND AND PURPOSE

Statins and fibrates can produce mild to life-threatening skeletal muscle damage. Resting chloride channel conductance (gCl), carried by the ClC-1 channel, is reduced in muscles of rats chronically treated with fluvastatin, atorvastatin or fenofibrate, along with increased resting cytosolic calcium in statin-treated rats. A high gCl, controlled by the Ca(2+)-dependent protein kinase C (PKC), maintains sarcolemma electrical stability and its reduction alters muscle function. Here, we investigated how statins and fenofibrate impaired gCl.

EXPERIMENTAL APPROACH

In rats treated with fluvastatin, atorvastatin or fenofibrate, we examined the involvement of PKC in gCl reduction by the two intracellular microelectrodes technique and ClC-1 mRNA level by quantitative real time-polymerase chain reaction. Direct drug effects were tested by patch clamp analysis on human ClC-1 channels expressed in human embryonic kidney (HEK) 293 cells.

KEY RESULTS

Chelerythrine, a PKC inhibitor, applied in vitro on muscle dissected from atorvastatin-treated rats fully restored gCl, suggesting the involvement of this enzyme in statin action. Chelerythrine partially restored gCl in muscles from fluvastatin-treated rats but not in those from fenofibrate-treated rats, implying additional mechanisms for gCl impairment. Accordingly, a decrease of ClC-1 channel mRNA was found in both fluvastatin- and fenofibrate-treated rat muscles. Fenofibric acid, the in vivo metabolite of fenofibrate, but not fluvastatin, rapidly reduced chloride currents in HEK 293 cells.

CONCLUSIONS AND IMPLICATIONS

Our data suggest multiple mechanisms underlie the effect of statins and fenofibrate on ClC-1 channel conductance. While statins promote Ca(2+)-mediated PKC activation, fenofibrate directly inhibits ClC-1 channels and both fluvastatin and fenofibrate impair expression of mRNA for ClC-1.

The protective effect of simvastatin against low dose streptozotocin induced type 1 diabetes in mice is independent of inhibition of HMG-CoA reductase

Besides a cholesterol-lowering effect, simvastatin possesses anti-inflammatory properties attributed to inhibition of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and/or direct binding to, and inhibition of, the integrin lymphocyte function associated antigen-1 (LFA-1). We have shown that simvastatin protects against multiple low dose streptozotocin (MLDS) induced type 1 diabetes in mice. Presently, we examined if this effect could be abolished by co-administration of mevalonic acid, thus determining if the protective effect is dependent or independent of inhibition of HMG-CoA reductase. Mevalonic acid did not affect the protective effect of simvastatin against MLDS diabetes. Moreover, spleens from these mice did not show any signs of toxic side-effects, thus excluding the possibility that the protective effect is secondary to a general inflammatory response. We suggest that simvastatin's protective effect mainly is independent of HMG-CoA reductase inhibition. This implies that inhibition of LFA-1 activation is important for the protective effect exerted by simvastatin.

Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases

BACKGROUND

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation.

REVIEW

We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here.

CONCLUSION

Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.