Statins as immunomodulators

Mevastatin in colon cancer by spectroscopic and microscopic methods - Raman imaging and AFM studies

One of the most important areas of medical science is oncology, which is responsible for both the diagnostics and treatment of cancer diseases. Simultaneously one of the main challenges of oncology is the development of modern drugs effective in the fight against cancer. Statins are a group of biologically active compounds with the activity of 3-hydroxy-3-methyl glutaryl-CoA reductase inhibitors, an enzyme catalyzing the reduction of 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) to mevalonic acid. By acting on this enzyme, statins inhibit the endogenous cholesterol synthesis which in turn causes the reduction of its systemic concentrations. However, in vitro and in vivo studies confirm also the cytostatic and cytotoxic effects of statins against various types of cancer cells including colon cancer. In the presented studies the influence of mevastatin on cancerous colon cells CaCo-2 by Raman spectroscopy and imaging is discussed and compared with biochemistry characteristic for normal colon cells CCD-18Co. Based on vibrational features of colon cells: normal cells CCD-18Co, cancerous cells CaCo-2 and cancerous cells CaCo-2 treated by mevastatin in different concentrations and incubation times we have confirmed the influence of this statin on biochemistry composition of cancerous human colon cells. Moreover, the spectroscopic results for colon normal cells and cancerous cells based on data typical for nucleic acids, proteins, lipids have been compared. The cytotoxisity of mevastatin was determined by using XTT tests.

Crosstalk between Statins and Cancer Prevention and Therapy: An Update

The importance of statins in cancer has been discussed in many studies. They are known for their anticancer properties against solid tumors of the liver or lung, as well as diffuse cancers, such as multiple myeloma or leukemia. Currently, the most commonly used statins are simvastatin, rosuvastatin and atorvastatin. The anti-tumor activity of statins is largely related to their ability to induce apoptosis by targeting cancer cells with high selectivity. Statins are also involved in the regulation of the histone acetylation level, the disturbance of which can lead to abnormal activity of genes involved in the regulation of proliferation, differentiation and apoptosis. As a result, tumor growth and its invasion may be promoted, which is associated with a poor prognosis. High levels of histone deacetylases are observed in many cancers; therefore, one of the therapeutic strategies is to use their inhibitors. Combining statins with histone deacetylase inhibitors can induce a synergistic anticancer effect.

Atorvastatin-loaded solid lipid nanoparticles as eye drops: proposed treatment option for age-related macular degeneration (AMD)

Statins, widely prescribed for cardiovascular diseases, are also being eyed for management of age-related macular degeneration (AMD). Poor bioavailability and blood-aqueous barrier may however limit significant ocular concentration of statins following oral administration. We for the first time propose and investigate local application of atorvastatin (ATS; representative statin) loaded into solid lipid nanoparticles (SLNs), as self-administrable eye drops. Insolubility, instability, and high molecular weight > 500 of ATS, and ensuring that SLNs reach posterior eye were the challenges to be met. ATS-SLNs, developed (2339/DEL/2014) using suitable components, quality-by-design (QBD) approach, and scalable hot high-pressure homogenization, were characterized and evaluated comprehensively for ocular suitability. ATS-SLNs were 8 and 12 times more bioavailable (AUC) in aqueous and vitreous humor, respectively, than free ATS. Three-tier (in vitro, ex vivo, and in vivo) ocular safety, higher corneal flux (2.5-fold), and improved stability (13.62 times) including photostability of ATS on incorporation in ATS-SLNs were established. Autoclavability and aqueous nature are the other highlights of ATS-SLNs. Presence of intact fluorescein-labeled SLNs (F-SLNs) in internal eye tissues post–in vivo application as eye drops provides direct evidence of successful delivery. Perinuclear fluorescence in ARPE-19 cells confirms the effective uptake of F-SLNs. Prolonged residence, up to 7 h, was attributed to the mucus-penetrating nature of ATS-SLNs.

Statin use and risk of severe bacterial infection in a population living with HIV: prospective cohort study of the ANRS CO3 Aquitaine Cohort 2000-2018

OBJECTIVES

Bacterial infections remain one of the main causes of morbidity and death in people living with HIV (PLHIV) in the most recent years. Several studies have demonstrated a protective effect of statins in the primary prevention of bacterial infections in other immunocompromised populations, but this effect remains controversial. The objective of this study was to evaluate the effect of statin use on the occurrence of a first episode of severe bacterial infection (SBI) in PLHIV in the ANRS CO3 Aquitaine cohort between 2000 and 2018.

METHODS

All individuals included in the prospective ANRS CO3 Aquitaine cohort who had at least two follow-up visits between 2000 and 2018 were included. The primary endpoint was the occurrence of a first episode of bacterial infection leading to hospitalization of ≥48 hours or death. Statin exposure was updated during follow-up. Marginal Cox structural models were developed to consider the potential indication bias and time-dependent confusion. Numerous sensitivity analyses were carried out.

RESULTS

In this study 51 658 person-years were followed. The overall incidence of a first episode of SBI was 12.4/1000 person-years. No effect of statins on the occurrence of SBI was demonstrated when subjects were considered on statins throughout their follow-up after treatment initiation (HR = 0.97; 95%CI: 0.75-1.25). The results were similar for the effect of statins on the risk of pneumonia and for all sensitivity analyses.

CONCLUSION

In this large cohort of PLHIV with 18 years of follow-up and a high risk of severe infections, we found no effect of statins on the risk of occurrence of SBI or pneumonia.

Human Rhinovirus Infections in Hematopoietic Cell Transplant Recipients: Risk Score for Progression to Lower Respiratory Tract Infection

•

Risk factors for rhinovirus lower respiratory tract infection are not well characterized.

•

Several risk factors in hematopoietic cell transplant recipients were identified.

•

A risk score for progression to lower respiratory tract infection was developed.

Human rhinovirus lower respiratory tract infection (LRTI) is associated with mortality after hematopoietic cell transplantation (HCT); however, risk factors for LRTI are not well characterized. We sought to develop a risk score for progression to LRTI from upper respiratory tract infection (URTI) in HCT recipients. Risk factors for LRTI within 90 days were analyzed using Cox regression among HCT recipients with rhinovirus URTI between January 2009 and March 2016. The final multivariable model included factors with a meaningful effect on the bootstrapped optimism corrected concordance statistic. Weighted score contributions based on hazard ratios were determined. Cumulative incidence curves estimated the probability of LRTI at various score cut-offs. Of 588 rhinovirus URTI events, 100 (17%) progressed to LRTI. In a final multivariable model allogeneic grafts, prior rhinovirus URTI, low lymphocyte count, low albumin, positive cytomegalovirus serostatus, recipient statin use, and steroid use ≥2 mg/kg/day were associated with progression to LRTI. A weighted risk score cut-off with the highest sensitivity and specificity was determined. Risk scores above this cut-off were associated with progression to LRTI (cumulative incidence 28% versus 11% below cut-off; P < .001). The weighted risk score for progression to rhinovirus LRTI can help identify and stratify patients for clinical management and for future clinical trials of therapeutics in HCT recipients.

A UK general practice population cohort study investigating the association between lipid lowering drugs and 30-day mortality following medically attended acute respiratory illness

Background. Cholesterol lowering drugs HMG-CoA reductase inhibitors (statins) and PPARα activators (fibrates) have been shown to reduce host inflammation via non-disease specific immunomodulatory mechanisms. Recent studies suggest that commonly prescribed drugs in general practice, statins and fibrates, may be beneficial in influenza-like illness related mortality. This retrospective cohort study examines the association between two lipid lowering drugs, statins and fibrates, and all-cause 30-day mortality following a medically attended acute respiratory illness (MAARI). Methods. Primary care patient data were retrospectively extracted from the UK Clinical Practice Research Datalink (CPRD) database. The sample comprised 201,179 adults aged 30 years or older experiencing a MAARI episode. Patient exposure to statins or fibrates was coded as separate dichotomous variables and deemed current if the most recent GP prescription was issued in the 30 days prior to MAARI diagnosis. Multivariable logistic regression and Cox regression were used for analyses. Adjustment was carried out for chronic lung disease, heart failure, metformin and glitazones, comorbidity burden, socio-demographic and lifestyle variables such as smoking status and body mass index (BMI). Statistical interaction tests were carried out to check for effect modification by gender, body mass index, smoking status and comorbidity. Results. A total of 1,096 (5%) patients died within the 30-day follow up period. Of this group, 213 (19.4%) were statin users and 4 (0.4%) were fibrate users. After adjustment, a significant 35% reduction in odds [adj OR; 0.65 (95% CI [0.52-0.80])] and a 33% reduction in the hazard [adj HR: 0.67 (95% CI [0.55-0.83])] of all-cause 30-day mortality following MAARI was observed in statin users. A significant effect modification by comorbidity burden was observed for the association between statin use and MAARI-related mortality. Fibrate use was associated with a non-significant reduction in 30-day MAARI-related mortality. Conclusion. This study suggests that statin use may be associated with a reduction in 30-day mortality following acute respiratory illness that is severe enough to merit medical consultation. Findings from this study support and strengthen similar observational research while providing a strong rationale for a randomised controlled trial investigating the potential role of statins in acute respiratory infections.

Pharmacological therapies for acute respiratory distress syndrome

PURPOSE OF REVIEW

Despite recent advances in the management of patients with acute respiratory distress syndrome (ARDS) by using protective ventilator strategies, the mortality rate of ARDS remains high. The complexity of the pathogenesis and the heterogeneity of coexisting diseases in patients with ARDS require critical care physicians and researchers to search for multiple therapeutic approaches in order to further improve patient outcome. This review article therefore focuses on the recent studies in the field of pharmacological intervention in ARDS.

RECENT FINDINGS

A number of approaches for pharmacological intervention have been evaluated in patients with ARDS, but most of them failed to reduce mortality or improve outcomes despite some promising observations seen in preclinical studies. Prior methods such as nitric oxide inhalation, neuromuscular blocking agents and corticosteroids may still have a place in the treatment, while novel therapeutic approaches including the use of angiotensin-converting enzyme inhibitors, statins and stem cells are currently under investigation.

SUMMARY

Overall, there is no proven pharmacological therapy in ARDS, but some pharmacological interventions were associated with beneficial effects in certain subgroups of patients depending on the cause, underlying diseases, the concurrent supportive therapies and timing. Further clinical trials are warranted to assess multiple outcome measurement of the promising pharmacological interventions in selected patients with ARDS.

Cholesterol lowering drug may influence cellular immune response by altering MHC II function

Major histocompatibility complex class II (MHC II) expressed on the surface of antigen-presenting cells (APCs) displays peptides to CD4⁺ T cells. Depletion of membrane cholesterol from APCs by methyl β-cyclodextrin treatment compromises peptide-MHC II complex formation coupled with impaired binding of conformational antibody, which binds close to the peptide binding groove of MHC II. Interestingly, the total cell surface of MHC II remains unaltered. These defects can be corrected by restoring membrane cholesterol. In silico docking studies with a three-dimensional model showed the presence of a cholesterol binding site in the transmembrane domain of MHC II (TM-MHC-II). From the binding studies it was clear that cholesterol, indeed, interacts with the TM-MHC-II and alters its conformation. Mutation of cholesterol binding residues (F240, L243, and F246) in the TM-MHC-II decreased the affinity for cholesterol. Furthermore, transfection of CHO cells with full-length mutant MHC II, but not wild-type MHC II, failed to activate antigen-specific T cells coupled with decreased binding of conformation-specific antibodies. Thus, cholesterol-induced conformational change of TM-MHC-II may allosterically modulate the peptide binding groove of MHC II leading to T cell activation.

Biomarker assessment of the immunomodulator effect of atorvastatin in stable renal transplant recipients and hypercholesterolemic patients

BACKGROUND

HMG-CoA reductase inhibitors (statins) have effects beyond lipid lowering, including immunomodulatory and anti-inflammatory properties. Statins are frequently combined with immunosuppressive agents in transplant recipients to modulate the hyperlipidemic side effects of the immunosuppressants. However, the role of statins in the immunosuppressive response that is achieved in individual patients remains to be assessed.

OBJECTIVE

The aim of this study was to evaluate the immunomodulatory effect of atorvastatin given alone and in combined treatment with tacrolimus and mycophenolate mofetil.

STUDY DESIGN

Two patient groups were studied: renal transplant recipients receiving tacrolimus and mycophenolate mofetil therapy, and hypercholesterolemic patients (the control group). Fasting blood samples were taken from participants before and 1 month after atorvastatin treatment was started to study a small battery of biomarkers that are able to reflect the range of the effects of immunosuppressive therapy and atorvastatin.

SETTING

All patients in the study were enrolled at the Hospital Clinic of Barcelona.

PATIENTS

All patients enrolled in the study were candidates for treatment with atorvastatin because of high cholesterol levels. One group consisted of 25 stable renal transplant recipients with low-density lipoprotein (LDL) cholesterol levels above 100 mg/dL after 3 months of therapeutic lifestyle changes, according to the guidelines of the National Kidney Foundation - Kidney Disease Outcomes Quality Initiative. The other group included 25 hypercholesterolemic patients with LDL cholesterol levels above target values for the patients' overall risk, as derived from the National Cholesterol Education Program Adult Treatment Panel III criteria.

INTERVENTION

Atorvastatin (Lipitor®) treatment was started at a fixed dose of 20 mg daily.

MAIN OUTCOME MEASURE

The studied biomarkers were lymphocyte proliferation, intracellular adenosine triphosphate (ATP) synthesis in CD4+ T cells, intralymphocytary cytokine expression (interleukin [IL]-2, interferon [IFN]-γ), soluble cytokine production (IL-2, IFN-γ, IL-10, IL-17, and transforming growth factor-β) and regulatory T (T(reg)) cells.

RESULTS

Atorvastatin proved to be an immunomodulatory agent, significantly decreasing lymphocyte proliferation by 15% (p = 0.001), increasing ATP levels by 16% (p = 0.0004), and showing a trend toward increasing T(reg) cells in hypercholesterolemic patients (p = 0.09). In the renal transplant recipients, atorvastatin therapy did not modify any of the biomarkers of immunosuppression that were studied.

CONCLUSION

Atorvastatin showed immunoregulatory effects on T cells in hypercholesterolemic patients. These effects were absent in renal transplant recipients, suggesting that the beneficial effects of atorvastatin in this patient group do not relate to immunoregulation. Therefore, statin treatment cannot be considered as a means to reduce the dose of immunosuppressive agents.

Biomarker assessment of the immunomodulator effect of atorvastatin in stable renal transplant recipients and hypercholesterolemic patients

BACKGROUND

HMG-CoA reductase inhibitors (statins) have effects beyond lipid lowering, including immunomodulatory and anti-inflammatory properties. Statins are frequently combined with immunosuppressive agents in transplant recipients to modulate the hyperlipidemic side effects of the immunosuppressants. However, the role of statins in the immunosuppressive response that is achieved in individual patients remains to be assessed.

OBJECTIVE

The aim of this study was to evaluate the immunomodulatory effect of atorvastatin given alone and in combined treatment with tacrolimus and mycophenolate mofetil.

STUDY DESIGN

Two patient groups were studied: renal transplant recipients receiving tacrolimus and mycophenolate mofetil therapy, and hypercholesterolemic patients (the control group). Fasting blood samples were taken from participants before and 1 month after atorvastatin treatment was started to study a small battery of biomarkers that are able to reflect the range of the effects of immunosuppressive therapy and atorvastatin.

SETTING

All patients in the study were enrolled at the Hospital Clinic of Barcelona.

PATIENTS

All patients enrolled in the study were candidates for treatment with atorvastatin because of high cholesterol levels. One group consisted of 25 stable renal transplant recipients with low-density lipoprotein (LDL) cholesterol levels above 100 mg/dL after 3 months of therapeutic lifestyle changes, according to the guidelines of the National Kidney Foundation - Kidney Disease Outcomes Quality Initiative. The other group included 25 hypercholesterolemic patients with LDL cholesterol levels above target values for the patients' overall risk, as derived from the National Cholesterol Education Program Adult Treatment Panel III criteria.

INTERVENTION

Atorvastatin (Lipitor®) treatment was started at a fixed dose of 20 mg daily.

MAIN OUTCOME MEASURE

The studied biomarkers were lymphocyte proliferation, intracellular adenosine triphosphate (ATP) synthesis in CD4+ T cells, intralymphocytary cytokine expression (interleukin [IL]-2, interferon [IFN]-γ), soluble cytokine production (IL-2, IFN-γ, IL-10, IL-17, and transforming growth factor-β) and regulatory T (T(reg)) cells.

RESULTS

Atorvastatin proved to be an immunomodulatory agent, significantly decreasing lymphocyte proliferation by 15% (p = 0.001), increasing ATP levels by 16% (p = 0.0004), and showing a trend toward increasing T(reg) cells in hypercholesterolemic patients (p = 0.09). In the renal transplant recipients, atorvastatin therapy did not modify any of the biomarkers of immunosuppression that were studied.

CONCLUSION

Atorvastatin showed immunoregulatory effects on T cells in hypercholesterolemic patients. These effects were absent in renal transplant recipients, suggesting that the beneficial effects of atorvastatin in this patient group do not relate to immunoregulation. Therefore, statin treatment cannot be considered as a means to reduce the dose of immunosuppressive agents.

Fluvastatin inhibits expression of the chemokine MDC/CCL22 induced by interferon-gamma in HaCaT cells, a human keratinocyte cell line

BACKGROUND AND PURPOSE

The macrophage-derived chemokine (MDC/CCL22) is a prototypic Th2-type chemokine intimately involved in Th2-skewed allergic diseases, such as atopic dermatitis and asthma. The statins (3-hydroxy-3-methyl glutaryl coenzyme A reductase inhibitors) have been demonstrated to relieve allergic inflammation. However, the immunological effects and mechanisms of statins against atopic dermatitis remain unknown, at least in vitro. This study aimed to define how different statins affect MDC expression in HaCaT cells, a human keratinocyte cell line.

EXPERIMENTAL APPROACH

To measure the effects of statins on MDC expression in HaCaT cells, we used a cell viability assay, reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay and Western blotting analyses.

KEY RESULTS

Fluvastatin, but not atorvastatin or simvastatin, inhibited MDC expression induced by interferon (IFN)-gamma and NF-kappaB activation. A NF-kappaB inhibitor, but not a STAT1 inhibitor, suppressed MDC expression in HaCaT cells. Further, inhibition of p38 mitogen-activated protein kinases (MAPKs) significantly suppressed IFN-gamma-induced MDC expression and NF-kappaB activation. Interestingly, fluvastatin suppressed IFN-gamma-induced NF-kappaB activation in parallel with p38 MAPK phosphorylation.

CONCLUSIONS AND IMPLICATIONS

These results indicate that fluvastatin inhibited expression of the CC chemokine MDC induced by IFN-gamma in HaCaT cells, by inhibiting NF-kappaB activation via the p38 MAPK pathway. This blockade of a Th2 chemokine by fluvastatin may suppress the infiltration of Th2 cells into skin lesions and lessen the skin inflammation seen in atopic dermatitis, suggesting a potential therapeutic use of fluvastatin for this condition.

Pravastatin attenuates interferon-gamma action via modulation of STAT1 to prevent aortic atherosclerosis in apolipoprotein E-knockout mice

1. The beneficial effects of pravastatin, beyond that of lowering cholesterol in atherosclerosis, include reducing the action of interferon (IFN)-gamma. Interferon-gamma activates the signal transducer and activator of transcription 1 (STAT1), but it is unclear whether the inhibitory effect of pravastatin in atherosclerosis is via modulation of the IFN-gamma/STAT1 pathway. Thus, the aim of the present study was to determine whether the action of pravastatin in preventing aortic atherosclerosis by attenuation of IFN-gamma action is dependent on STAT1. 2. Male apolipoprotein E-knockout (apoE(-/-)) mice were fed a diet containing 1.25% cholesterol (w/w). Mice were divided into two groups, one of which was supplemented with pravastatin (80 mg/kg per day). Male C57BL/6J mice were fed a normal diet and served as the control group (n = 12 per group). 3. Atherosclerotic lesions in the aortic root were assessed by staining sections haematoxylin and eosin. Serum concentrations of IFN-gamma and IFN-gamma mRNA expression in the thoracoabdominal aorta were determined by ELISA and real-time quantitative polymerase chain reaction methods, respectively. Expression of phosphorylated STAT1 (pSTAT1), interferon regulating factor (IRF)-1 and suppressors of cytokine signalling 1 (SOCS1) was determined in the thoracoabdominal aorta using Western blot analysis. 4. After 8 weeks, pravastatin treatment significantly prevented the formation of atherosclerotic lesions (P < 0.05) and reduced serum IFN-gamma concentrations (P < 0.05) and levels of IFN-gamma mRNA within the aorta (P < 0.01). Pravastatin significantly decreased the expressions of pSTAT1 and IRF-1 within the aorta and significantly increased expression of SOCS1. 5. These results suggest that the actions of pravastatin in attenuating the action of IFN-gamma and subsequently preventing aortic atherosclerosis may depend, at least in part, on modulation of STAT1 activity. This providing us with a new therapeutic approach and a clearer insight into the clinical benefits of pravastatin.

Cardiovascular and oral disease interactions: what is the evidence?

This paper reviews the evidence for the interaction of oral disease (more specifically, periodontal infections) with cardiovascular disease. Cardiovascular disease is a major cause of death worldwide, with atherosclerosis as the underlying aetiology in the vast majority of cases. The importance of the role of infection and inflammation in atherosclerosis is now widely accepted, and there has been increasing awareness that immune responses are central to atherogenesis. Chronic inflammatory periodontal diseases are among the most common chronic infections, and a number of studies have shown an association between periodontal disease and an increased risk of stroke and coronary heart disease. Although it is recognised that large-scale intervention studies are required, pathogenic mechanism studies are nevertheless required so as to establish the biological rationale. In this context, a number of hypotheses have been put forward; these include common susceptibility, inflammation via increased circulating cytokines and inflammatory mediators, direct infection of the blood vessels, and the possibility of cross-reactivity or molecular mimicry between bacterial and self-antigens. In this latter hypothesis, the progression of atherosclerosis can be explained in terms of the immune response to bacterial heat shock proteins (HSPs). Because the immune system may not be able to differentiate between self-HSP and bacterial HSP, an immune response generated by the host directed at pathogenic HSP may result in an autoimmune response to similar sequences in the host. Furthermore, endothelial cells express HSPs in atherosclerosis, and cross-reactive T cells exist in the arteries and peripheral blood of patients with atherosclerosis. Each of these hypotheses is reviewed in light of current research. It is concluded that although atherosclerotic cardiovascular disease is almost certainly a multifactorial disease, there is now strong evidence that infection and inflammation are important risk factors. As the oral cavity is one potential source of infection, it is wise to try to ensure that any oral disease is minimised. This may be of significant benefit to cardiovascular health and enables members of the oral health team to contribute to their patients' general health.

[A case of interstitial lung disease with atorvastatin (Tahor) and a review of the literature about these effects observed under statins]

The 3-Hydroxy-3-methyl-glutaryl coenzyme A (HGM-CoA) reductase inhibitors, or statins, are competitive inhibitors of the rate-limiting enzyme in cholesterol synthesis. Generally, statins have an excellent safety profile. Elevations of liver transaminases and creatine phosphokinase with myalgia have been associated with the use of HGM-Co A reductase inhibitors, case reports of rhabdomyolysis are rare, most occurring with concomitant use with other drugs such as cyclosporin, fusidic acid and gemfibrozil. We describe here the clinical case of a patient who developed interstitial lung disease as probably a result of the use of statins which particularly increased with long-term atorvastatin treatment. The present review details some case-reports of interstitial lung disease reported under statins in the literature. Few systemic adverse effects such as lupus-like-syndromes and polymyositis have been reported. Recent experimentations have demonstrated that cholesterol is not the only intracellular target of statins but that they also have a potential role in atherosclerosis and in organ transplantation as immunosuppressor agents.

Interferon-gamma induces major histocompatibility class II transactivator (CIITA), which mediates collagen repression and major histocompatibility class II activation by human aortic smooth muscle cells

Chronic inflammation in atherosclerosis is responsible for plaque instability through alterations in extracellular matrix. Previously, we demonstrated that major histocompatibility class II (MHC II) transactivator (CIITA) in a complex with regulatory factor for X box 5 (RFX5) is a crucial protein mediating interferon (IFN)-gamma-induced repression of collagen type I gene transcription in fibroblasts. This article demonstrates that, in smooth muscle cells (SMCs), IFN-gamma dramatically increases the expression of CIITA isoforms III and IV, with no increase in expression of CIITA isoform I. Expression of CIITA III and IV correlates with decreased collagen type I and increased MHC II gene expression. Exogenous expression of CIITA I, III, and IV, in transiently transfected SMCs, represses collagen type I promoters (COL1A1 and COL1A2) and activates MHC II promoter. Levels of CIITA and RFX5 increase in the nucleus of cells treated with IFN-gamma. Moreover, simvastatin lowers the IFN-gamma-induced expression of RFX5 and MHC II in addition to repressing collagen expression. However, simvastatin does not block the IFN-gamma-induced expression of CIITA III and IV, suggesting a CIITA-independent mechanism. This first demonstration that RFX5 and CIITA isoforms are expressed in SMCs after IFN-gamma stimulation suggest that CIITA could be a key factor in plaque stability in atherosclerosis.

In vitro effect of statins on cytokine production and mitogen response of human peripheral blood mononuclear cells

The in vitro effect of the hydrophilic statin - pravastatin - and three hydrophobic statins - atorvastatin, lovastatin and simvastatin - on the production of IL-1beta, IL-1ra, IL-2, IL-6 and IFN-gamma by human peripheral blood mononuclear cells (PBMC) and their response to mitogens was examined. Lovastatin and simvastatin increased the production of IL-1beta in a dose dependent manner and reduced secretion of IL-1ra at high concentration. These two statins exerted a dose dependent inhibitory effect on IL-2 production and reduced the secretion of IFNgamma at high dose. Atorvastatin did not affect IL-1beta, but suppressed IL-1ra, IL-2 and IFNgamma production. Atorvastatin, lovastatin and simvastatin caused a dose dependent inhibition of mitogen-induced proliferation of PBMC. IL-6 production was not affected by any one of the statins. While pravastatin caused a slight reduction in the proliferative response of PBMC to PHA, it did not affect either their response to Con A and PWM, or the secretion of cytokines tested.

Metaanalysis of statins and survival in de novo cardiac transplantation

BACKGROUND

The use of HMG CoA reductase inhibitors (statins) after cardiac transplantation has been suggested to decrease the incidence of severe rejection and improve survival. Individual investigations that have led to this suggestion are randomized (but not placebo-controlled) studies, including small patient numbers that have (and thus underpowered) and enrolling heterogeneous subjects (including retransplant recipients). The purpose of this pooled analysis was to quantify the benefit of statins on survival in de novo cardiac transplant recipients.

METHODS

Medline (1966 to 2003) was queried using the keywords statin, HMG CoA reductase inhibitors, cardiac transplantation, transplant, cholesterol, atorvastatin, fluvastatin, lovastatin, pravastatin, and simvastatin. In addition, we searched the cited literature and previously published systematic reviews. Of 36 articles retrieved, 3 randomized controlled studies met our population inclusion criteria; namely age >18 years, de novo heart transplant recipients, statin therapy within 3 months, and > or = 1-year follow-up. Pooled data were metaanalyzed by Mantel-Haenszel tests using a random effects model that included tests for heterogeneity.

RESULTS

The three pooled studies included 246 patients (statin, n = 129; no statin, n = 117) and 27 events (11%). The pooled analysis demonstrated a significant reduction in mortality with statin use (RR 0.31; 95% CI 0.13 to 0.7; P = .006) without significant heterogeneity (P = .7) among the studies. Two of the three studies reported allograft rejection with hemodynamic compromise. The pooled analysis demonstrated a significant benefit on this endpoint (RR 0.22, 95% CI 0.08 to 0.63; P = .004).

CONCLUSION

This meta-analysis demonstrates that statin therapy decreases rejection episodes with hemodynamic consequences and improves 1-year heart transplant survival.

Statins: novel additions to the dermatologic arsenal?

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins), atorvastatin, cerivastatin, fluvastatin, pravastatin, lovastatin and simvastatin, reduce atherogenesis and cardiovascular morbidity. Besides, there is growing evidence that statins have immunomodulatory activities. Statins downregulate the expression of adhesion molecules, intercellular adhesion molecule-1 (ICAM-1), monocyte chemotactic protein-1 (MAC-1) and lymphocyte function-associated antigen-1 (LFA-1), on leucocytes and endothelial cells and, through binding to LFA-1, interfere with ICAM-1-LFA-1 interaction, which is crucial for activation of lymphocytes by antigen-presenting cells, ingress of leucocytes into the inflammation sites and immunologic cytotoxicity. Statins inhibit the inducible expression of major histocompatibility complex class II in several cell types including macrophages and downregulate the expression of T-helper-1 (Th1) chemokine receptors on T cells, leading further to inhibition of activation of lymphocytes and their infiltration into the inflammation sites. Statins block the induction of inducible nitric oxide synthase and the expression of several proinflammatory cytokines such as tumour necrosis factor-alpha and interferon-gamma in macrophages and possess antioxidant effects. These agents inhibit the proliferation of immunocytes and the activation of natural killer cells. Regarding the above facts and in view of their safety and inexpensiveness, statins may prove invaluable in the treatment of a multiplicity of dermatologic disorders, especially those characterized by ingress of activated leucocytes into the skin, such as alopecia areata, vitiligo, lichen planus, subacute cutaneous lupus erythematosus, erythema multiforme, psoriasis, bullous pemphigoid, systemic sclerosis, mycosis fungoides, toxic epidermal necrolysis and Behcet's disease.

Cell-based screen of HMG-CoA reductase inhibitors and expression regulators using LC–MS

We present an integrated consolidation of previously reported methods for screening hydroxymethylglutaryl-coenzyme A reductase (HMGR) inhibitors in 96-well microtiter plates with rapid workup using established mammalian cell lines and liquid chromatography-mass spectrometry analysis. Inhibitors as well as expression regulators of HMGR (inducers or repressors) can be screened. To validate the method, three competitive inhibitors of HMGR (lovastatin, simvastatin, and atorvastatin), as well as a potent sterol repressor of HMGR synthesis (25-hydroxycholesterol), were assayed on two cell lines: HepG2, a human hepatic derived cell line, and L cells, a subline of NCTC clone 929 mouse fibroblasts. The direct inhibition of HMGR by statins, induction of HMGR synthesis by the same statins following incubation with the cells, and repression of HMGR synthesis by 25-hydroxycholesterol were confirmed.

Genetic polymorphisms in cytochrome P450 enzymes: effect on efficacy and tolerability of HMG-CoA reductase inhibitors

Adverse drug reactions are common; they are responsible for a number of debilitating side effects and are a significant cause of death following drug therapy. It is now clear that a significant proportion of these adverse drug reactions, as well as therapeutic failures, are caused by genetic polymorphism, genetically based interindividual differences in drug absorption, disposition, metabolism, or excretion. HMG-CoA reductase inhibitors are generally very well tolerated and easy to administer with good patient acceptance. There are only two uncommon but potentially serious adverse effects related to HMG-CoA reductase inhibitor therapy: hepatotoxicity and myopathy. The occurrence of lethal rhabdomyolysis in patients treated with cerivastatin has prompted concern on the part of physicians and patients regarding the tolerability of HMG-CoA reductase inhibitors. Apart from pravastatin and rosuvastatin, HMG-CoA reductase inhibitors are metabolized by the phase I cytochrome P450 (CYP) superfamily of drug metabolizing enzymes. The best-characterized pharmacogenetic polymorphisms are those within this enzyme family. One of these enzymes, CYP2D6, plays an important role in the metabolism of simvastatin. It has been shown that the cholesterol-lowering effect as well as the efficacy and tolerability of simvastatin is influenced by CYP2D6 genetic polymorphism. Because the different HMG-CoA reductase inhibitors differ, with respect to the degree of metabolism by the different CYP enzymes, genotyping may help to select the appropriate HMG-CoA reductase inhibitor and the optimal dosage during the start of the treatment and will allow for more efficient individual therapy. A detailed knowledge of the genetic basis of individual drug response is potentially of major clinical and economic importance.

The Roles of Cytokines, Inflammation and Immunity in Vascular Diseases

Recent findings regarding the roles of cytokines, inflammation and immunity during the development of atherosclerosis were reviewed. Especially, the relationships among pro-inflammatory cytokines such as interleukin (IL)-1, IL-18 and osteopontin, and anti-inflammatory cytokines such as IL-1 receptor antagonist, IL-10 and IL-18 binding protein to inflammation and atherosclerosis were investigated and are described in detail. In addition, helicobacter pylori and C pneumoniae infections to inflammations regarding the persistence of inflammation have been pointed out. A pro-inflammatory genotype or haplotype and toll-like receptors have been shown to be involved in human atherosclerosis. Atherosclerosis might therefore be a specific form of the chronic inflammatory process. In addition to hyperlipidemia, infections, cytokines and immunity might also be involved in the development of atherosclerosis. Certain treatments that reduce coronary risk also limit inflammation. Statins possess multiple pleiotropic effects such as an anti-inflammatory effect in addition to a lipid-lowering effect.

Potential Role of Statins in Inflammation and Atherosclerosis

The mevalonate pathway plays a crucial role in regulation of cellular cholesterol synthesis and isoprenoid groups. The entire pathway is closely regulated by feedback from an enzyme in the cascade, 3-hydroxy-3-methyl-CoA (HMG-CoA) reductase, as well as LDL receptors. Clinically, inhibition of this pathway by statins, potent inhibitors of HMG-CoA reductase, has been shown to reduce plasma levels of LDL cholesterol and several clinical trials with this group of drugs have demonstrated a remarked improvement in cardiovascular risk reduction. Interestingly, the improvement in cardiovascular end points in those trials was superior to estimations calculated from the effect on LDL cholesterol lowering. These findings support the idea of non-lipid effects of statins in atherosclerosis. Further, recent observations using in vivo and in vitro models of atherosclerosis have shed light on their potential role for manipulation of various cellular functions via inhibition of the mevalonate pathway. Among them, recently identified inhibitory effects of statins on monocyte-endothelial interaction suggest their effect on inflammation. Herein, we discuss recent progress in this area of study, with special focus on the biological function of statins.