Modulation of COX-2 expression by statins in human monocytic cells

Rosuvastatin attenuates total-tau serum levels and increases expression of miR-124-3p in dyslipidemic Alzheimer's patients: a historic cohort study

microRNAs are candidate diagnostic biomarkers for Alzheimer's disease. This study aimed to compare Silymarin with Rosuvastatin and placebo on total-Tau protein level and expression levels of microRNAs and TGF-β and COX-2 in Alzheimer's patients with secondary dyslipidemia. 36 mild AD patients with dyslipidemia were divided into three groups of 12. The first group received silymarin (140mg), the second group received placebo (140mg), and the third group recieved Rosuvastatin (10mg). Tablets were administered three times a day for Six months. The blood samples of the patients were collected before and after the intervention and the serum was separated. Using the RT-qPCR method, the expression levels of miR-124-3p and miR-125b-5p were assessed, and the serum levels of total-Tau, TGF-β, and COX-2 enzyme were measured using the ELISA method. Data were analyzed with SPSS software. In this study, the level of Δtotal-Tau was significantly lower in the Rosuvastatin group compared to the placebo (P = 0.038). Also, a significant reduction in the level of ΔTGF-β was observed in the Silymarin to Rosuvastatin group (p = 0.046) and ΔmiR-124-3p was significantly increased in the Rosuvastatin compared to the placebo group (p = 0.044). Rosuvastatin outperformed silymarin in decreasing Δtotal-Tau serum levels and enhancing expression of ΔmiR-124-3p, attributed to Rosuvastatin's capacity to lower cholesterol levels and inflammation concurrently. Conversely, silymarin was more effective than Rosuvastatin in reducing levels of ΔTGF-β. Serum miR-124-3p could serve as a promising diagnostic biomarker and a new therapeutic focus in AD.

The great obstetrical syndromes and the placenta

Although historically pre-eclampsia, preterm birth, abruption, fetal growth restriction and stillbirth have been viewed as clinically distinct entities, a growing body of literature has demonstrated that the placenta and its development is the root cause of many cases of these conditions. This has led to the term 'the great obstetrical syndromes' being coined to reflect this common origin. Although these conditions mostly manifest in the second half of pregnancy, a failure to complete deep placentation (the transition from histiotrophic placentation to haemochorial placenta at 10-18 weeks of gestation via a second wave of extravillous trophoblast invasion), is understood to be key to the pathogenesis of the great obstetrical syndromes. While the reasons that the placenta fails to achieve deep placentation remain active areas of investigation, maternal inflammation and thrombosis have been clearly implicated. From a clinical standpoint these mechanisms provide a biological explanation of how low-dose aspirin, which affects the COX-1 receptor (thrombosis) and the COX-2 receptor (inflammation), prevents not just pre-eclampsia but all the components of the great obstetrical syndromes if initiated early in pregnancy. The optimal dose of low-dose aspirin that is maximally effective in pregnancy remains a question open for further research. Additionally, other candidate medications have been identified that may also prevent pre-eclampsia, and further study of them may offer therapeutic options beyond low-dose aspirin. Interestingly, three of the eight identified compounds (hydroxychloroquine, metformin and pravastatin) are known to decrease inflammation.

Exploring the Role of Plasma Lipids and Statin Interventions on Multiple Sclerosis Risk and Severity: A Mendelian Randomization Study

BACKGROUND AND OBJECTIVES

There has been considerable interest in statins because of their pleiotropic effects beyond their lipid-lowering properties. Many of these pleiotropic effects are predominantly ascribed to Rho small guanosine triphosphatases (Rho GTPases) proteins. We aimed to genetically investigate the role of lipids and statin interventions on multiple sclerosis (MS) risk and severity.

METHOD

We used two-sample Mendelian randomization (MR) to investigate (1) the causal role of genetically mimic both cholesterol-dependent (through low-density lipoprotein cholesterol (LDL-C) and cholesterol biosynthesis pathway) and cholesterol-independent (through Rho GTPases) effects of statins on MS risk and MS severity, (2) the causal link between lipids (high-density lipoprotein cholesterol [HDL-C] and triglycerides [TG]) levels and MS risk and severity, and (3) the reverse causation between lipid fractions and MS risk. We used summary statistics from the Global Lipids Genetics Consortium (GLGC), eQTLGen Consortium, and the International MS Genetics Consortium (IMSGC) for lipids, expression quantitative trait loci, and MS, respectively (GLGC: n = 188,577; eQTLGen: n = 31,684; IMSGC (MS risk): n = 41,505; IMSGC (MS severity): n = 7,069).

RESULTS

The results of MR using the inverse-variance weighted method show that genetically predicted RAC2, a member of cholesterol-independent pathway (OR 0.86 [95% CI 0.78-0.95], p-value 3.80E-03), is implicated causally in reducing MS risk. We found no evidence for the causal role of LDL-C and the member of cholesterol biosynthesis pathway on MS risk. The MR results also show that lifelong higher HDL-C (OR 1.14 [95% CI 1.04-1.26], p-value 7.94E-03) increases MS risk but TG was not. Furthermore, we found no evidence for the causal role of lipids and genetically mimicked statins on MS severity. There is no evidence of reverse causation between MS risk and lipids.

DISCUSSION

Evidence from this study suggests that RAC2 is a genetic modifier of MS risk. Because RAC2 has been reported to mediate some of the pleiotropic effects of statins, we suggest that statins may reduce MS risk through a cholesterol-independent pathway (that is, RAC2-related mechanism(s)). MR analyses also support a causal effect of HDL-C on MS risk.

Therapeutic effects and the impact of statins in the prevention of ulcerative colitis in preclinical models: A systematic review

Ulcerative Colitis (UC) is a chronic inflammatory condition of the large intestines. Although great advances have been made in the management of the disease with the introduction of immunomodulators and biological agents, the treatment of UC is still a challenge. So far, there are no definitive therapies for this condition. Statins are potent inhibitors of cholesterol biosynthesis, possess beneficial effects on primary and secondary prevention of coronary heart disease, and have high tolerability and safety. Furthermore, they may have potential roles in UC management due to their possible anti-inflammatory, immunomodulatory, and antioxidant activities. This systematic review aimed to gather information about the potential benefits of statins for managing UC, reducing inflammation and disease remission in animal models. A systematic search was performed in PubMed/MEDLINE, Scopus, Web of Science, and Virtual Health Library. The data were summarized in tables and critically analyzed. After the database search, 21 relevant studies were identified as eligible for this review. Preclinical studies using several colitis-induction protocols and various statins have shown numerous beneficial effects of these drugs on reducing disease activity, inflammatory profile, oxidative stress, and general clinical parameters of animals with UC. These studies revealed the potential of statins against the pathogenesis of UC. However, there are still important gaps regarding the molecular mechanisms of action of statins, leading to some contradictory results. Thus, more research on the molecular level to determine the roles of statins in colitis should be carried out to elucidate their mechanisms of action.

Modulation of proteomic and inflammatory signals by Bradykinin in podocytes

Podocyte damage is one of the hallmarks of diabetic nephropathy leading to proteinuria and kidney damage. The underlying mechanisms of podocyte injury are not well defined. Bradykinin (BK) was shown to contribute to diabetic kidney disease. Here, we evaluated the temporal changes in proteome profile and inflammatory signals of podocytes in response to BK (10⁻⁷M). Protein profile was evaluated by liquid chromatography mass Spectrometry (LC-MS/MS) analysis. Proteome profile analysis of podocytes treated with BK (10⁻⁷M) for 3 and 6 h, revealed 61 proteins that were differentially altered compared to unstimulated control podocytes. Pathway enrichment analysis suggested inhibition of cell death pathways, engagement of cytoskeletal elements and activation of inflammatory pathways. One of the inflammatory proteins that was identified to be induced by BK treatment is Prostaglandin (PG) H Synthase-2 (Cyclooxygenase-2, COX-2). In addition, BK significantly induced the production and release of PGE₂ and this effect was inhibited by both COX-2 and MEK Kinase inhibitors, demonstrating that the production of PGE₂ by BK is mediated via COX-2 and MAPK-dependent mechanisms. These findings provide a global understanding of the effector modulated proteome in response to BK and also reveal BK as an important modulator of inflammation and a potential player in podocyte injury.

gem-Difluorobisarylic derivatives: design, synthesis and anti-inflammatory effect

Introduction

New fluorinated diaryl ethers and bisarylic ketones were designed and evaluated for their anti-inflammatory effects in primary macrophages.

Methods

The synthesis of the designed molecules started from easily accessible and versatile gem-difluoro propargylic derivatives. The desired aromatic systems were obtained using Diels-Alder/aromatization sequences and this was followed by Pd-catalyzed coupling reactions and, when required, final functionalization steps. Both direct inhibitory effects on cyclooxygenase-1 or -2 activities, protein expression of cyclooxygenase-2 and nitric oxide synthase-II and the production of prostaglandin E₂, the pro-inflammatory nitric oxide and interleukin-6 were evaluated in primary murine bone marrow-derived macrophages in response to lipopolysaccharide. Docking of the designed molecules in cyclooxygenase-1 or -2 was performed.

Results

Only fluorinated compounds exerted anti-inflammatory activities by lowering the secretion of interleukin-6, nitric oxide, and prostaglandin E₂, and decreasing the protein expression of inducible nitric oxide synthase and cyclooxygenase-2 in mouse primary macrophages exposed to lipopolysaccharide, as well as cyclooxygenase activity for some inhibitors with different efficiencies depending on the R-groups. Docking observation suggested an inhibitory role of cyclooxygenase-1 or -2 for compounds A3, A4 and A5 in addition to their capacity to inhibit nitrite, interleukin-6, and nitric oxide synthase-II and cyclooxygenase-2 expression.

Conclusion

The new fluorinated diaryl ethers and bisarylic ketones have anti-inflammatory effects in macrophages. These fluorinated compounds have improved potential anti-inflammatory properties due to the fluorine residues in the bioactive molecules.

Inducible nitric oxide synthase-derived extracellular nitric oxide flux regulates proinflammatory responses at the single cell level

The role of nitric oxide (NO) in cancer progression has largely been studied in the context of tumor NOS2 expression. However, pro- versus anti-tumor signaling is also affected by tumor cell-macrophage interactions. While these cell-cell interactions are partly regulated by NO, the functional effects of NO flux on proinflammatory (M1) macrophages are unknown. Using a triple negative murine breast cancer model, we explored the potential role of macrophage Nos2 on 4T1 tumor progression. The effects of NO on macrophage phenotype were examined in bone marrow derived macrophages from wild type and Nos2^−/− mice following in vitro stimulation with cytokine/LPS combinations to produce low, medium, and high NO flux. Remarkably, Nos2 induction was spatially distinct, where Nos2^high cells expressed low cyclooxygenase-2 (Cox2) and vice versa. Importantly, in vitro M1 polarization with IFNγ+LPS induced high NO flux that was restricted to cells harboring depolarized mitochondria. This flux altered the magnitude and spatial extent of hypoxic gradients. Metabolic and single cell analyses demonstrated that single cell Nos2 induction limited the generation of hypoxic gradients in vitro, and Nos2-dependent and independent features may collaborate to regulate M1 functionality. It was found that Cox2 expression was important for Nos2^high cells to maintain NO tolerance. Furthermore, Nos2 and Cox2 expression in 4T1 mouse tumors was spatially orthogonal forming distinct cellular neighborhoods. In summary, the location and type of Nos2^high cells, NO flux, and the inflammatory status of other cells, such as Cox2^high cells in the tumor niche contribute to Nos2 inflammatory mechanisms that promote disease progression of 4T1 tumors.

Heme oxygenase-1-Dependent anti-inflammatory effects of atorvastatin in zymosan-injected subcutaneous air pouch in mice

Statins exert pleiotropic and beneficial anti-inflammatory and antioxidant effects. We have previously reported that macrophages treated with statins increased the expression of heme oxygenase-1 (HO-1), an inducible anti-inflammatory and cytoprotective stress protein, responsible for the degradation of heme. In the present study, we investigated the effects of atorvastatin on inflammation in mice and analyzed its mechanism of action in vivo. Air pouches were established in 8 week-old female C57BL/6J mice. Atorvastatin (5 mg/kg, i.p.) and/or tin protoporphyrin IX (SnPPIX), a heme oxygenase inhibitor (12 mg/kg, i.p.), were administered for 10 days. Zymosan, a cell wall component of Saccharomyces cerevisiae, was injected in the air pouch to trigger inflammation. Cell number and levels of inflammatory markers were determined in exudates collected from the pouch 24 hours post zymosan injection by flow cytometry, ELISA and quantitative PCR. Analysis of the mice treated with atorvastatin alone displayed increased expression of HO-1, arginase-1, C-type lectin domain containing 7A, and mannose receptor C-type 1 in the cells of the exudate of the air pouch. Flow cytometry analysis revealed an increase in monocyte/macrophage cells expressing HO-1 and in leukocytes expressing MRC-1 in response to atorvastatin. Mice treated with atorvastatin showed a significant reduction in cell influx in response to zymosan, and in the expression of proinflammatory cytokines and chemokines such as interleukin-1α, monocyte chemoattractant protein-1 and prostaglandin E₂. Co-treatment of mice with atorvastatin and tin protoporphyrin IX (SnPPIX), an inhibitor of heme oxygenase, reversed the inhibitory effect of statin on cell influx and proinflammatory markers, suggesting a protective role of HO-1. Flow cytometry analysis of air pouch cell contents revealed prevalence of neutrophils and to a lesser extent of monocytes/macrophages with no significant effect of atorvastatin treatment on the modification of their relative proportion. These findings identify HO-1 as a target for the therapeutic actions of atorvastatin and highlight its potential role as an in vivo anti-inflammatory agent.

The Combined Use of Phenothiazines and Statins Strongly Affects Doxorubicin-Resistance, Apoptosis, and Cox-2 Activity in Colon Cancer Cells

Since none of the multidrug resistance (MDR) modulators tested so far found their way into clinic, a novel approach to overcome the MDR of cancer cells has been proposed. The combined use of two MDR modulators of dissimilar mechanisms of action was suggested to benefit from the synergy between them. The effect of three phenothiazine derivatives that were used as single agents and in combination with simvastatin on cell growth, apoptosis induction, activity, and expression of cyclooxygenase-2 (COX-2) in doxorubicin-resistant colon cancer cells (LoVo/Dx) was investigated. Treatment of LoVo/Dx cells by phenothiazine derivatives combined with simvastatin resulted in an increase of doxorubicin cytotoxicity and its intracellular accumulation as compared to the treatment with phenothiazine derivatives that were used as single agents. Similarly, LoVo/Dx cells treated with two-component mixture of modulators showed the reduced expression of ABCB1 (P-glycoprotein) transporter and COX-2 enzyme, both on mRNA and protein level. Reduced expression of anti-apoptotic Bcl-2 protein and increased expression of pro-apoptotic Bax were also detected. Additionally, COX-2 activity was diminished, and caspase-3 activity was increased to a higher extent by phenothiazine derivative:simvastatin mixtures than by phenothiazine derivatives themselves. Therefore, the introduction of simvastatin strengthened the anti-MDR, anti-inflammatory, and pro-apoptotic properties of phenothiazines in LoVo/Dx cells.

Repurposing of statins via inhalation to treat lung inflammatory conditions

Despite many therapeutic advancements over the past decade, the continued rise in chronic inflammatory lung diseases incidence has driven the need to identify and develop new therapeutic strategies, with superior efficacy to treat these diseases. Statins are one class of drug that could potentially be repurposed as an alternative treatment for chronic lung diseases. They are currently used to treat hypercholesterolemia by inhibiting the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, that catalyses the rate limiting step in the mevalonate biosynthesis pathway, a key intermediate in cholesterol metabolism. Recent research has identified statins to have other protective pleiotropic properties including anti-inflammatory, anti-oxidant, muco-inhibitory effects that may be beneficial for the treatment of chronic inflammatory lung diseases. However, clinical studies have yielded conflicting results. This review will summarise some of the current evidences for statins pleiotropic effects that could be applied for the treatment of chronic inflammatory lung diseases, their mechanisms of actions, and the potential to repurpose statins as an inhaled therapy, including a detailed discussion on their different physical-chemical properties and how these characteristics could ultimately affect treatment efficacies. The repurposing of statins from conventional anti-cholesterol oral therapy to inhaled anti-inflammatory formulation is promising, as it provides direct delivery to the airways, reduced risk of side effects, increased bioavailability and tailored physical-chemical properties for enhanced efficacy.

Aspirin alone and combined with a statin suppresses eicosanoid formation in human colon tissue

Eicosanoids, including prostaglandins (PGs) and thromboxanes, are broadly bioactive lipid mediators and increase colon tumorigenesis possibly through chronic inflammatory mechanisms. Epidemiological and experimental data suggest that acetylsalicylic acid (ASA) helps prevent colorectal cancer (CRC), possibly through cyclooxygenase (COX)-mediated suppression of eicosanoid, particularly PGE2, formation. Recent studies suggest that statins prevent CRC and improve survival after diagnosis. We identified patients on ASA and/or statin treatment undergoing routine colonoscopy and measured eicosanoid levels in colonic mucosa with targeted metabolomics technology (LC-MS/MS). ASA-treated individuals (n = 27) had significantly lower tissue eicosanoid levels of most COX-derived metabolites than untreated individuals (n = 31). In contrast, COX-derived lipid metabolites tended to be higher in patients with statin treatment (n = 7) as compared with those not receiving statins (n = 24). This effect was not discernible in subjects treated with ASA and statins (n = 11): Individuals treated with both drugs showed a pronounced suppression of COX-derived eicosanoids in colon tissue, even compared with subjects treated with ASA alone. Our data from a routine clinical setting support the hypothesis that ASA and statins could inhibit CRC development via lipid mediator modification. Further studies should directly investigate the effect of dual ASA and statin treatment on colon tumorigenesis in humans.

Effects of Statins and Xuezhikang on the Expression of Secretory Phospholipase A2, Group IIA in Rat Vascular Smooth Muscle Cells

Atherosclerosis is a multifactorial vascular disease characterized by formation of inflammatory lesions. Secretory phospholipase A2, group IIA (sPLA2-IIA) is involved in this process and plays a critical role. However, the exact role of sPLA2-IIA in cardiovascular inflammation is more complicated and remains unclear. Furthermore, both statins and Xuezhikang (XZK) are widely used in the prevention and treatment of cardiovascular disease risk because of their pleiotropic effects on the cardiovascular system. However, their effects on sPLA2-IIA are still controversial. We investigated the regulation of sPLA2-IIA by rat thoracic aorta smooth muscle cells (VSMCs) in culture. Cells were first incubated with IL-1β alone to induce expression of sPLA2-IIA and then treated with several concentrations of statins or XZK for different times in the absence or presence of IL-1β. We tested the expression of sPLA2-IIA, including sPLA2-IIA mRNA, protein, as well as activity. We found that statins or IL-1β increase the expression of sPLA2-IIA in VSMCs and the effect is based on a synergetic relationship between them. However, for the first time, we observed that XZK effectively reduces sPLA2-IIA expression in IL-1β-treated VSMCs. Our findings may shine a new light on the clinical use of XZK and statins in the prevention and treatment of atherosclerosis-related thrombosis.

Chemopreventive effect of omega-3 polyunsaturated fatty acids and atorvastatin in rats with bladder cancer

Bladder cancer remains a huge concern for the medical community because of its incidence and prevalence rates, as well as high percentage of recurrence and progression. Omega-3 polyunsaturated fatty acids and atorvastatin proved anti-inflammatory effects through peroxisome proliferator-activated receptor gamma mechanism. However, their chemopreventive effect still remained to be examined and clarified. In this study, bladder cancer was induced in rats by the chemical carcinogen N-butyl-N-(4-hydroxybutyl)nitrosamine. Omega-3 polyunsaturated fatty acids (docosahexaenoic acid and eicosapentaenoic acid: 2:3 w/w; 1200 mg/kg) and/or atorvastatin (6 mg/kg) were given orally daily to rats for eight consecutive weeks concomitantly with N-butyl-N-(4-hydroxybutyl)nitrosamine and continued for further 4 weeks after cessation of N-butyl-N-(4-hydroxybutyl)nitrosamine administration. The histopathological examination of rat bladder revealed the presence of tumors and the absence of apoptotic bodies in sections from N-butyl-N-(4-hydroxybutyl)nitrosamine group, while tumors were absent and apoptotic bodies were clearly observed in sections from rat groups treated with omega-3 polyunsaturated fatty acids, atorvastatin, or both drugs. The study of the molecular mechanisms illustrated downregulation of COX-2 and P53 (mutant) genes and suppression of transforming growth factor beta-1 and the lipid peroxidation product malondialdehyde in serum of rats of the three treated groups. This chemopreventive effect was confirmed by and associated with lower level of bladder tumor antigen in urine. However, the combined treatment with both drugs exhibited the major protective effect and nearly corrected the dyslipidemia that has been induced by N-butyl-N-(4-hydroxybutyl)nitrosamine. Collectively, omega-3 polyunsaturated fatty acids and atorvastatin, besides having anti-inflammatory properties, proved a chemopreventive effect against bladder cancer, which nominates them to be used as adjuvant therapy with other chemotherapeutics.

Lovastatin lactone elicits human lung cancer cell apoptosis via a COX-2/PPARγ-dependent pathway

Statins (3-hydroxy-3-methylglutaryl coenzyme A [HMG-CoA] reductase inhibitors) are well-established agents to treat hyperlipidemic states. Experimental and epidemiological evidence further implies an anticancer effect of these substances. This study investigates the mechanism underlying human lung cancer cell death by lovastatin and the role of the prostaglandin (PG)-synthesizing enzyme cyclooxygenase-2 (COX-2) in this process. In A549 and H358 lung carcinoma cells the lipophilic prodrug lovastatin lactone led to a concentration-dependent decrease of viability and induction of DNA fragmentation, whereas its HMG-CoA-inhibitory, ring-open acid form was inactive in this respect. Apoptotic cell death by lovastatin was accompanied by high intracellular levels of the lactone form, by upregulation of COX-2 mRNA and protein, as well as by increased formation of peroxisome proliferator-activated receptor γ (PPARγ)-activating PGD₂ and 15-deoxy-Δ^12,14-PGJ₂. Cells were significantly less sensitive to lovastatin-induced apoptotic cell death, when the expression or activity of COX-2 was suppressed by siRNA or by the COX-2 inhibitor NS-398. Apoptosis by lovastatin was likewise reversed by the PPARγ antagonist GW9662. Fluorescence microscopy analyses revealed a lovastatin-induced cytosol-to-nucleus translocation of PPARγ that was inhibited by NS-398. Collectively, this study demonstrates COX-2 induction and subsequent COX-2-dependent activation of PPARγ as a hitherto unknown mechanism by which lovastatin lactone induces human lung cancer cell death.

Simvastatin Reduces Lipopolysaccharides-Accelerated Cerebral Ischemic Injury via Inhibition of Nuclear Factor-kappa B Activity

Preceding infection or inflammation such as bacterial meningitis has been associated with poor outcomes after stroke. Previously, we reported that intracorpus callosum microinjection of lipopolysaccharides (LPS) strongly accelerated the ischemia/reperfusion-evoked brain tissue damage via recruiting inflammatory cells into the ischemic lesion. Simvastatin, 3-hydroxy-3-methylgultaryl (HMG)-CoA reductase inhibitor, has been shown to reduce inflammatory responses in vascular diseases. Thus, we investigated whether simvastatin could reduce the LPS-accelerated ischemic injury. Simvastatin (20 mg/kg) was orally administered to rats prior to cerebral ischemic insults (4 times at 72, 48, 25, and 1-h pre-ischemia). LPS was microinjected into rat corpus callosum 1 day before the ischemic injury. Treatment of simvastatin reduced the LPS-accelerated infarct size by 73%, and decreased the ischemia/reperfusion-induced expressions of pro-inflammatory mediators such as iNOS, COX-2 and IL-1β in LPS-injected rat brains. However, simvastatin did not reduce the infiltration of microglial/macrophageal cells into the LPS-pretreated brain lesion. In vitro migration assay also showed that simvastatin did not inhibit the monocyte chemoattractant protein-1-evoked migration of microglial/macrophageal cells. Instead, simvastatin inhibited the nuclear translocation of NF-κB, a key signaling event in expressions of various proinflammatory mediators, by decreasing the degradation of IκB. The present results indicate that simvastatin may be beneficial particularly to the accelerated cerebral ischemic injury under inflammatory or infectious conditions.

Statins Modulate Cyclooxygenase-2 and Microsomal Prostaglandin E Synthase-1 in Human Hepatic Myofibroblasts

Statins have been shown to exert anti-inflammatory and anti-fibrogenic properties in the liver. In the present study, we explored the mechanisms underlying anti-fibrogenic effects of statins in isolated hepatic myofibroblasts and focused on cyclooxyegnase-2, a major anti-proliferative pathway in these cells. We show that simvastatin and fluvastatin inhibit thymidine incorporation in hMF in a dose-dependent manner. Pretreatment of cells with NS398, a COX-2 inhibitor, partially blunted this effect. cAMP levels, essential to the inhibition of hMF proliferation, were increased by statins and inhibited by non-steroidal anti-inflammatory drugs. Since statins modify prenylation of some important proteins in gene expression, we investigated the targets involved using selective inhibitors of prenyltransferases. Inhibition of geranylgeranylation resulted in the induction of COX-2 and mPGES-1. Using gel retardation assays, we further demonstrated that statins potentially activated the NFκB and CRE/E-box binding for COX-2 promoter and the binding of GC-rich regions and GATA for mPGES-1. Together these data demonstrate that statin limit hepatic myofibroblasts proliferation via a COX-2 and mPGES-1 dependent pathway. These data suggest that statin-dependent increase of prostaglandin in hMF contributes to its anti-fibrogenic effect.

Rho protein GTPases and their interactions with NFκB: crossroads of inflammation and matrix biology

The RhoGTPases, with RhoA, Cdc42 and Rac being major members, are a group of key ubiquitous proteins present in all eukaryotic organisms that subserve such important functions as cell migration, adhesion and differentiation. The NFκB (nuclear factor κB) is a family of constitutive and inducible transcription factors that through their diverse target genes, play a major role in processes such as cytokine expression, stress regulation, cell division and transformation. Research over the past decade has uncovered new molecular links between the RhoGTPases and the NFκB pathway, with the RhoGTPases playing a positive or negative regulatory role on NFκB activation depending on the context. The RhoA–NFκB interaction has been shown to be important in cytokine-activated NFκB processes, such as those induced by TNFα (tumour necrosis factor α). On the other hand, Rac is important for activating the NFκB response downstream of integrin activation, such as after phagocytosis. Specific residues of Rac1 are important for triggering NFκB activation, and mutations do obliterate this response. Other upstream triggers of the RhoGTPase–NFκB interactions include the suppressive p120 catenin, with implications for skin inflammation. The networks described here are not only important areas for further research, but are also significant for discovery of targets for translational medicine.

Effects of simvastatin on pulmonary fibrosis, pulmonary hypertension and exercise capacity in bleomycin-treated rats

AIM

Pulmonary fibrosis is often complicated by pulmonary hypertension. Statins reduce fibroblast activity in vitro and pulmonary hypertension in vivo. We investigated whether Simvastatin exerts beneficial effects on pulmonary fibrosis and pulmonary hypertension in Bleomycin-treated rats in vivo.

METHODS

Rats were randomly assigned to controls, Bleomycin, Bleomycin plus Simvastatin from day 1 to 28 and Bleomycin plus Simvastatin from day 13 to 28. 28 days after Bleomycin instillation, right ventricular systolic pressure (RVSP), right ventricular mass (RV/(LV+S)), right ventricular and circulating brain natriuretic peptide (BNP) levels were determined to assess pulmonary hypertension. Pulmonary hydroxyproline content (HPC), pulmonary connective tissue growth factor (CTGF) transcription and lung compliance (LC) were analysed to characterize pulmonary fibrosis. Exercise capacity was determined by treadmill tests.

RESULTS

Compared with controls, Bleomycin increased RVSP, RV/(LV+S), BNP levels, HPC and CTGF transcription and decreased LC significantly. Simvastatin administered from day 1 to 28 normalized all these parameters. Simvastatin administered from day 13 to 28 had no effect on HPC and LC, but reduced RV/(LV+S) significantly and induced a strong trend to lower RVSP and BNP levels. Exercise capacity was reduced by Bleomycin. Simvastatin significantly improved exercise intolerance in both treatment groups.

CONCLUSIONS

Simvastatin prevents the development of pulmonary fibrosis, but fails to attenuate already established pulmonary fibrosis. In contrast, it ameliorates pulmonary hypertension and thereby exercise capacity in the prevention and the treatment group regardless of its effects on pulmonary fibrosis. Whether statins are a treatment option in humans with pulmonary fibrosis needs to be investigated by further study.

Role of nitric oxide and CCAAT/enhancer-binding protein transcription factor in statin-dependent induction of heme oxygenase-1 in mouse macrophages

The effect of statins on heme oxygenase-1 (HO-1) was compared in 2 murine cell lines, RAW 264.7 and J774A.1 cell lines, and in primary peritoneal macrophages of BALB/c or C57BL/6 mice. The role of endogenous nitric oxide and the type of transcription factors involved were explored. Simvastatin and fluvastatin induced HO-1. Pretreatment of cells with l-NMMA or 1400 W, two different nitric oxide synthase inhibitors, partially blocked statin-dependent induction of HO-1 in RAW 264.7 and J774A.1 but not in primary peritoneal macrophages. Induction of HO-1 by statins was dependent on p-38 MAP kinase activation in all types of macrophages. In RAW 264.7 cells, both statins increased the activity of reporter genes linked to the proximal 1.3 kbp promoter of HO-1 (EC50 of 1.4±0.3 µM for simvastatin and 0.6±0.03 µM for fluvastatin). This effect was significantly blocked by 1400 W (80±5.2% inhibition, p<0.02) and mevalonate, the direct metabolite of HMGCoA reductase. Gel retardation experiments implicated C/EBPβ, AP-1 but not USF, for both RAW 264.7 and primary peritoneal macrophages of C57BL/6 mice. Collectively we showed a differential role of endogenous nitric oxide between macrophage cell lines and primary macrophages and an effect of statins in the protection against inflammation by increasing HO-1 expression.

The molecular link between C-C-chemokine ligand 2-induced leukocyte recruitment and hyperalgesia

The chemokine C-C-chemokine ligand 2 (CCL2) (formerly known as MCP, macrophage chemotactic protein) is one of the important genes upregulated in different types of pain both in animals and humans. CCL2 governs the recruitment of C-C chemokine receptor 2-expressing monocytes into inflamed tissue. In contrast to neutrophilic chemokines, intraplantar injection of CCL2 in Wistar rats recruited macrophages and neutrophils and simultaneously lowered nociceptive thresholds. CCL2-induced hyperalgesia was abolished by prior systemic leukocyte depletion by cyclophosphamide and was reconstituted by local adoptive transfer of donor macrophages but not of neutrophils. Antagonists against transient receptor potential vannilloid 1 inhibited thermal and against transient receptor potential ankyrin 1 blocked mechanical hyperalgesia. Peripheral but not central activation of cyclooxygenase-2 (Cox-2) were critical for CCL2-induced hyperalgesia. In vitro CCL2 did not directly stimulate Cox-2 expression or prostaglandin E2 formation but slightly enhanced the formation of reactive oxygen species in monocytes and macrophages. In vivo, increased immunoreactivity for 4-hydroxy-2-nonenal (4-HNE), a downstream product of reactive oxygen species and known inducer of Cox-2, was observed and colocalized with Cox-2 in ED1 (CD68) positive infiltrating cells. No hyperalgesia, 4-HNE, or Cox-2 immunoreactivity was seen in leukocyte-depleted rats that were reconstituted with macrophages in the absence of CCL2, supporting the important role of CCL2.

PERSPECTIVE

CCL2 plays a dual role: 1) promoting monocyte/macrophage recruitment into tissue; and 2) potentially stimulating macrophages in the tissue to produce 4-HNE and subsequently Cox-2, all resulting in the induction of hyperalgesia via transient receptor potential vannilloid 1 and transient receptor potential ankyrin 1. This encourages pharmacological efforts targeting CCL2/C-C chemokine receptor 2 and macrophages for treatment of inflammatory pain.

Simvastatin prevents the induction of interleukin-6 gene expression by titanium particles in human osteoblastic cells

One of the most important complications of total joint arthroplasty is failure associated with periprosthetic osteolysis, a process mainly initiated by the biological response to wear-derived products from the biomaterials in service. The inflammatory mediator interleukin-6 (IL-6) plays a key role in the establishment and progression of aseptic loosening. Metal particles specifically up-regulate IL-6 production in bone-forming cells and implant-bone interfacial tissues. The use of statins has been recently associated with a significantly reduced risk of revision in patients that undergo total hip arthroplasty. We hypothesized that simvastatin (Simv) could modulate the osteoblastic response to titanium particles (Ti) by attenuating the production of IL-6. Pre-treatment of human osteoblastic cells with Simv down-regulated Ti particle-induced IL-6 gene expression at mRNA and protein levels. The effect of Simv on Ti-induced IL-6 production in osteoblastic cells could not be explained by inhibition of the internalization of metal particles. The mechanism involved in this down-regulation is based in the inhibition of the HMG-CoA/GGPP/RhoA/ROCK pathway, independently of Simv effects in the cholesterol synthesis. The cytokine-lowering property of Simv has been observed in Saos-2 cells and human primary osteoblasts (hOBs) exposed to Ti particles, and was further enhanced when hOBs were co-cultured with macrophages.

Atorvastatin suppresses inflammatory response induced by oxLDL through inhibition of ERK phosphorylation, IκBα degradation, and COX-2 expression in murine macrophages

Macrophages crosstalk with oxidized low-density lipoprotein (oxLDL), play a critical role in the initiation, progression, and subsequently stability of atherosclerotic plaques. Statins, inhibitors of HMG CoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase, reduce the expression of inflammatory proteins in addition to their lipid-lowering action. However, the effect and detailed anti-inflammation mechanisms of statins in macrophages induced by oxLDL remain unclearly. In the present study, we investigated the effect of atorvastatin on inflammatory response upon oxLDL stimulation in murine macrophages and analyzed the underlying mechanisms. Tumor necrosis factor (TNF)α and monocyte chemoattractant protein-1 (MCP-1) mRNA levels were assayed by real-time PCR. The expression of cyclooxygenases-2 (COX-2) was detected by real-time PCR and Western blotting. While mitogen-activated protein kinase (MAPK) phosphorylation and IκBα degradation were determined by Western blotting. Our results showed that exposure of RAW264.7 cells to oxLDL, substantially changed the morphology of the cells and increased TNFα and MCP-1 secretion. While pretreatment with atorvastatin resulted in a significant inhibition of oxLDL-induced morphological alteration and inflammatory cytokines expression in a dose-dependent fashion. Further investigation of the molecular mechanism revealed that oxLDL upregulated the transcription and protein expression of COX-2 in a time-dependent manner. Whereas, pretreatment with atorvastatin suppressed COX-2 expression, MAPK activation and IκBα degradation. Thus, we conclude that the anti-inflammatory effect of atorvastatin is mediated through the inhibition of proinflammatory COX-2. Furthermore, suppression of ERK phosphorylation and IκBα degradation is involved in this regulation. Our findings provide a novel evidence that statins suppress inflammatory response, exert its anti-atherogenic actions via against inflammation beyond cholesterol-lowing effect.

Regulation of apoptosis in human melanoma and neuroblastoma cells by statins, sodium arsenite and TRAIL: a role of combined treatment versus monotherapy

Treatment of melanoma cells by sodium arsenite or statins (simvastatin and lovastatin) dramatically modified activities of the main cell signaling pathways resulting in the induction of heme oxygenase-1 (HO-1) and in a downregulation of cyclooxygenase-2 (COX-2) protein levels. Through heme degradation and the production of carbon monoxide and biliverdin, HO-1 plays a protective role in different scenario of oxidative stress followed by mitochondrial apoptosis. Both sodium arsenite and statins could be efficient inducers of apoptosis in some melanoma cell lines, but often exhibited only modest proapoptotic activity in others, due to numerous protective mechanisms. We demonstrated in the present study that treatment by sodium arsenite or statins with an additional inhibition of HO-1 expression (or activation) caused a substantial upregulation of apoptosis in melanoma cells. Sodium arsenite- or statin-induced apoptosis was independent of BRAF status (wild type versus V600E) in melanoma lines. Monotreatment required high doses of statins (20-40 μM) for effective induction of apoptosis. As an alternative approach, pretreatment of melanoma cells with statin at decreased doses (5-20 μM) dramatically enhanced TRAIL-induced apoptosis, due to suppression of the NF-κB and STAT3-transcriptional targets (including COX-2) and downregulation of cFLIP-L (a caspase-8 inhibitor) protein levels. Furthermore, combined treatment with sodium arsenite and TRAIL or simvastatin and TRAIL efficiently induced apoptotic commitment in human neuroblastoma cells. In summary, our findings on enhancing effects of combined treatment of cancer cells using statin and TRAIL provide the rationale for further preclinical evaluation.

An evolutionary analysis of RAC2 identifies haplotypes associated with human autoimmune diseases

The human RAC2 gene encodes a small GTP-binding protein with a pivotal role in immune activation and in the induction of peripheral immune tolerance through restimulation-induced cell death (RICD). Different human pathogens target the protein product of RAC2, suggesting that the gene may be subject to natural selection, and that variants in RAC2 may affect immunological phenotypes in humans. We scanned the genomic region encompassing the entire transcription unit for the presence of putative noncoding regulatory elements conserved across mammals. This information was used to select two RAC2 gene regions and analyze their intraspecific genetic diversity. Results suggest that a region covering the 3' untranslated region has been a target of multiallelic balancing selection (or diversifying selection), and three major RAC2 haplogroups occur in human populations. Haplotypes belonging to one of these clades are associated with increased susceptibility to multiple sclerosis (P = 0.022) and earlier onset of disease symptoms (P = 0.025). This same haplogroup is significantly more common in patients with Crohn's disease compared with healthy controls (P = 0.048). These data reinforce recent evidences that susceptibility alleles/haplotypes are shared among multiple autoimmune disorders and support a causal "role for RAC2" variants in the pathogenesis of autoimmune diseases. Other genes with a role in RICD have previously been associated with autoimmunity in humans, suggesting that this pathway and RAC2 may represent novel therapeutic targets in autoimmune disorders.

Inhibition of Rac activity alleviates lipopolysaccharide-induced acute pulmonary injury in mice

BACKGROUND

Rac small GTPases play important roles in cytoskeleton and many cell functions including cell cycle, cell growth, cell adhesion and gene transcription. Here, we investigated the roles of Rac including Rac1 and Rac2 in lipopolysaccharide (LPS)-induced pulmonary injury.

METHODS

After LPS was intratracheally instilled to lungs in mice, Rac, CDC42 and RhoA activation assay by pull-down and West blot, inflammatory cell infiltration assay by counting cell numbers and lung histological examination, pro-inflammatory mediator mRNA expression assay by quantitative RT-PCR, measurement of myeloperoxidase (MPO) activity, Evans Blue and albumin accumulation by spectrophotometry were performed to evaluate the roles of Rac in pulmonary injury by using its specific inhibitor, NSC23766.

RESULTS

LPS challenge led to increases of both Rac1 and Rac2, but not CDC42 or RhoA activities in lungs, and intraperitoneal administration with NSC23766 inhibited both Rac1 and Rac2, but not CDC42 or RhoA activities. Treatment with NSC23766 at 1 or 3mg/kg not only reduced the inflammatory cells infiltration and MPO activities, but also inhibited pro-inflammatory mediators, tumor necrosis factor-α and interleukin-1β, mRNA expression. Moreover, in vitro neutrophil migration assay and in vivo microvascular permeability assay indicated that NSC23766 not only inhibited neutrophil transwell migration toward a chemoattractant, fMLP, but also reduced Evans Blue and albumin accumulation in LPS-challenged lungs. LPS activated both Rac1 and Rac2, but not CDC42 or RhoA activities in lungs, and specific inhibition of Rac activities by NSC23766 effectively alleviated LPS-induced injury.

GENERAL SIGNIFICANCE

Rac could be a potential target for therapeutic intervention of pulmonary inflammation.

Role of prostaglandin pathway and alendronate-based carriers to enhance statin-induced bone

This study investigated the role of the prostaglandin (PG) pathway in locally applied, simvastatin-induced oral bone growth. The possibility of enhancing long-term bone augmentation with an alendronate-based carrier was initiated. Mandibles of 44 mature female rats were treated bilaterally with the following combinations: 2 mg of simvastatin in ethanol (SIM-EtOH), EtOH, 2 mg of simvastatin acid complexed with alendronate-beta-cyclodextrin conjugate (SIM/ALN-CD), ALN-CD, or ALN. Bone wash technology (injection of PBS and re-collection by suction) was used to sample injection sites at baseline (day 0), and 3, 7, 14, and 21 days post-treatment. After 21-24 or 48 days, histomorphometric analysis was done. The amount of PGE(2) in bone wash fluid was measured by ELISA, normalized by total protein, and compared between high and low bone growth groups (ANOVA) and correlated with subsequent bone histology at 21 days (Spearman). SIM-stimulated PGE(2) synthase and EP4 receptor mRNA in murine osteoblast and fibroblast cell lines were evaluated with real-time PCR. Single injections of 2 mg of SIM-EtOH induced significantly more new bone than control side after 21 days. PGE(2)/protein ratios peaked at day 7 and were correlated with the subsequent 21-day new bone width. The correlations at day 14 between PGE(2) and new bone width changed to a negative relationship in the test group. SIM-stimulated osteoblasts expressed increased mRNA levels of PGE receptor EP4, while SIM activated PGE synthesis in fibroblasts. SIM/ALN-CD tended to preserve bone long-term. Findings suggest that PGE pathway activation and higher levels of PGE(2) during the first week following SIM-induced bone growth are desirable, and alendronate-beta-cyclodextrin conjugates not only act as tissue-specific carriers, but preserve new bone.

Anticancer efficacy of simvastatin on prostate cancer cells and tumor xenografts is associated with inhibition of Akt and reduced prostate-specific antigen expression

Prostate cancer is the second-leading cause of cancer-associated death among men in the United States. There has been renewed interest in the potential therapeutic benefits of statins for cancer. Simvastatin, a widely used generic drug for preventing cardiovascular events, is well known for its effects on cellular proliferation and inflammation, two key processes that also determine the rate of tumor growth. Although a growing body of evidence suggests that statins have the potential to reduce the risk of many cancers, there are discrepancies over the pro- and anticancer effects of statins. In the current study, we sought to investigate the effects of simvastatin on the Akt pathway in prostate cancer cells with respect to the regulation of various cell functions in vitro and tumor growth in vivo. Time- and dose-dependent effects of simvastatin on LNCaP (androgen-dependent) and PC3 (androgen-independent) cells indicate that treatment with simvastatin at concentrations as low as 25 μM was sufficient to inhibit serum-stimulated Akt activity. Akin to this, treatment with simvastatin significantly inhibited serum-induced cell migration, invasion, colony formation, and proliferation. Simvastatin-mediated effects on colony formation were rescued by adenovirus-mediated expression of constitutively active Akt (myristoylated Akt) in PC3 cell lines. A PC3 xenograft model performed in nude mice exhibited reduced tumor growth with simvastatin treatment associated with decreased Akt activity and reduced prostate-specific antigen (PSA) levels. Our findings demonstrate the therapeutic benefits of simvastatin for prostate cancer and suggest a link between simvastatin, regulation of Akt activity, and PSA expression in prostate tumors.

Material properties of the cell dictate stress-induced spreading and differentiation in embryonic stem cells

Growing evidence suggests that physical microenvironments and mechanical stresses, in addition to soluble factors, help direct mesenchymal-stem-cell fate. However, biological responses to a local force in embryonic stem cells remain elusive. Here we show that a local cyclic stress through focal adhesions induced spreading in mouse embryonic stem cells but not in mouse embryonic stem-cell-differentiated cells, which were ten times stiffer. This response was dictated by the cell material property (cell softness), suggesting that a threshold cell deformation is the key setpoint for triggering spreading responses. Traction quantification and pharmacological or shRNA intervention revealed that myosin II contractility, F-actin, Src or cdc42 were essential in the spreading response. The applied stress led to oct3/4 gene downregulation in mES cells. Our findings demonstrate that cell softness dictates cellular sensitivity to force, suggesting that local small forces might have far more important roles in early development of soft embryos than previously appreciated.

Statins inhibit cyclooxygenase-2 and matrix metalloproteinase-9 in human endothelial cells: anti-angiogenic actions possibly contributing to plaque stability

AIMS

Cyclooxygenase (COX)-2 expression is increased in inflammation and angiogenesis and also in atherosclerotic plaques, where it co-localizes with metalloproteinases (MMPs) involved in the fibrous cap weakening. Insight into the regulation of COX-2 and MMP-9 expression suggests the involvement of a Rho-dependent pathway. Because statins interfere with Rho activation, we investigated the statin effect on COX-2 and MMP expressions in the human endothelium.

METHODS AND RESULTS

Simvastatin and atorvastatin were incubated with endothelial cells for 12 h before stimulation with phorbol myristate acetate or tumour necrosis factor-alpha, for times suitable to assess the endothelial tube differentiation on Matrigel and COX-2 and MMPs activities, proteins, and mRNA expressions. At 0.1-10 micromol/L, both statins reduced COX-2 expression and activity, without affecting COX-1. The statin effect was reversed by mevalonate and geranylgeranyl-pyrophosphate and mimicked by the Rho inhibitor C3 transferase, indicating the involvement of Rho in the signal transduction pathway leading to COX-2 expression. In parallel, statins, as well as COX-2 inhibitors, reduced the MMP-9 stimulated release and the endothelial tubular differentiation.

CONCLUSION

In the human vascular endothelium, statins reduce COX-2 and MMP-9 expression and activity. Through this mechanism, statins exert an anti-angiogenic effect possibly contributing to the cholesterol-lowering-unrelated protective effects of statins against plaque inflammatory angiogenesis and rupture.

Eicosanoid release is increased by membrane destabilization and CFTR inhibition in Calu-3 cells

The antiinflammatory protein annexin-1 (ANXA1) and the adaptor S100A10 (p11), inhibit cytosolic phospholipase A2 (cPLA2α) by direct interaction. Since the latter is responsible for the cleavage of arachidonic acid at membrane phospholipids, all three proteins modulate eicosanoid production. We have previously shown the association of ANXA1 expression with that of CFTR, the multifactorial protein mutated in cystic fibrosis. This could in part account for the abnormal inflammatory status characteristic of this disease. We postulated that CFTR participates in the regulation of eicosanoid release by direct interaction with a complex containing ANXA1, p11 and cPLA2α. We first analyzed by plasmon surface resonance the in vitro binding of CFTR to the three proteins. A significant interaction between p11 and the NBD1 domain of CFTR was found. We observed in Calu-3 cells a rapid and partial redistribution of all four proteins in detergent resistant membranes (DRM) induced by TNF-α. This was concomitant with increased IL-8 synthesis and cPLA2α activation, ultimately resulting in eicosanoid (PGE2 and LTB4) overproduction. DRM destabilizing agent methyl-β-cyclodextrin induced further cPLA2α activation and eicosanoid release, but inhibited IL-8 synthesis. We tested in parallel the effect of short exposure of cells to CFTR inhibitors Inh172 and Gly-101. Both inhibitors induced a rapid increase in eicosanoid production. Longer exposure to Inh172 did not increase further eicosanoid release, but inhibited TNF-α-induced relocalization to DRM. These results show that (i) CFTR may form a complex with cPLA2α and ANXA1 via interaction with p11, (ii) CFTR inhibition and DRM disruption induce eicosanoid synthesis, and (iii) suggest that the putative cPLA2/ANXA1/p11/CFTR complex may participate in the modulation of the TNF-α-induced production of eicosanoids, pointing to the importance of membrane composition and CFTR function in the regulation of inflammation mediator synthesis.

Can statins suppress the development of abdominal aortic aneurysms? A review of the current evidence

Statins possess several pleiotropic effects and have been shown in vitro and in vivo to inhibit the expression of inflammatory mediators and downregulate molecules involved in extracellular matrix (ECM) degradation. Recent observational studies in humans suggest that statins may have a role in abdominal aortic aneurysm (AAA) prevention or may even inhibit aneurysm expansion. In this review, we summarize the effects of statins on the vessel wall of aneurysmal aortas and currently available data concerning their inhibitory effects on aneurysm progression.

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.

C-reactive protein: the harbinger of cardiovascular diseases

Coronary heart disease remains the major cause of mortality and morbidity in the United States and other western countries despite major advances in its treatment. During the last decades, many markers of coronary artery disease have been found which help predict future risk of cardiovascular events. High-sensitivity C-reactive protein has been studied extensively and was seen to be associated with a higher risk of cardiovascular events in patients with acute coronary syndromes and/or peripheral artery disease. Discussed in this review is the latest literature about this marker and its association with cardiovascular disease, as well as the latest therapeutic options available.

Simvastatin and indomethacin have similar anti-inflammatory activity in a rat model of acute local inflammation

Statins, such as simvastatin, lower circulating cholesterol levels and are widely prescribed for the treatment of hypercholesterolaemia. Several studies have shown unexpected effects of statins on inflammation. We studied the anti-inflammatory effect of simvastatin using a standard model of an acute local inflammation, the carrageenan-induced footpad oedema. Experimental groups (n = 6-8) were given simvastatin in a dose range 5-30 mg/kg, indomethacin 1-8 mg/kg and methylcellulose (control) per os. Footpad volume was measured with a plethysmograph and compared with the pre-injection volume of the same paw. Swelling (in microlitres) was then calculated, and in drug-treated animals, per cent inhibition was derived through comparison with the control group. Histopathological examination of the skin biopsies was performed to examine severity of paw skin lesions and to confirm the simvastatin-induced inhibition of acute inflammation. Both simvastatin and indomethacin administered orally, 1 hr before carrageenan injection, significantly reduced the extent of footpad oedema. Indomethacin dose-dependently blocked the swelling; the maximal effect was obtained with 8 mg/kg by 48.3% (P < 0.05). Simvastatin produced a comparable anti-inflammatory activity at a dose of 5 mg/kg (32%), while 10 and 30 mg/kg caused a 47.6% and 51.7% reduction, respectively, with the maximal effect observed at 20 mg/kg by 57.2% (P < 0.05). The comparison of the ED(50) of these agents on molar basis showed equipotent anti-inflammatory activity. Histopathological examination of the footpad skin biopsies revealed that simvastatin, dose-dependently and comparablly to indomethacin, reduced polymorphonuclear leucocyte infiltration. These data support the hypothesis that simvastatin has an acute anti-inflammatory activity.