Role of 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitors, angiotensin-converting enzyme inhibitors, cyclooxygenase-2 inhibitors, and aspirin in anti-inflammatory and immunomodulatory treatment of cardiovascular diseases

Chitosan-Coated PLGA Nanoparticles for Enhanced Ocular Anti-Inflammatory Efficacy of Atorvastatin Calcium

Background

Atorvastatin calcium (AT) is an ocular anti-inflammatory with limited bioavailability when taken orally due to its low solubility in low pH and extensive first-pass effect. To overcome these problems, AT was entrapped in polymeric nanoparticles (NPs) to improve surface properties and sustained release, in addition to achieving site-specific action.

Methods

AT was entrapped in chitosan (CS)-coated polylactic-co-glycolic acid (PLGA) NPs to form AT-PLGA-CS-NPs (F1). F1 and free AT were embedded in thermosensitive Pluronic^®127-hydroxypropyl methylcellulose (HPMC) to form thermosensitive gels (F2) and (F3) while F4 is AT suspension in water. F1 was assessed for size, surface charge, polydispersity index (PDI), and morphology. F2 and F3 were examined for gelation temperature, gel strength, pH, and viscosity. In vitro release of the four formulations was also investigated. The ocular irritancy and anti-inflammatory efficacy of formulations against prostaglandin E₁-(PGE₁) induced ocular inflammation in rabbits were investigated by counting the polymorphonuclear leukocytes (PMNs) and protein migrated in tears.

Results

Oval F1 of 80.0–190.0±21.6 nm exhibited a PDI of 0.331 and zeta potential of ‏17.4±5.62 mV with a positive surface charge. F2 and F3 gelation temperatures were 35.17±0.22°C and 36.93±0.31°C, viscosity 12,243±0.64 and 9759±0.22 cP, gel strength 15.56±0.6 and 12.45±0.1 s, and pHs of 7.4±0.02 and 7.4±0.1, respectively. In vitro release of F1, F2, F3, and F4 were 48.21±0.31, 26.48±0.5, 84.76±0.11, and 100% after 24 hrs, respectively. All formulations were non-irritant. F2 significantly inhibited lid closure up to 3 h, PMN counts and proteins in tear fluids up to 5 h compared to other formulations.

Conclusion

AT-PLGA-CS-NP thermosensitive gels proved to be successful ocular anti-inflammatory drug delivery systems.

Effects of weight loss and pharmacotherapy on inflammatory markers of cardiovascular disease

Obesity is currently an epidemic, and the prevalence of cardiovascular risk factors is increasing dramatically as a result. Visceral adiposity is correlated with a proinflammatory and prothrombotic state that is believed to promote atherosclerosis and acute coronary syndromes. This article will review clinical trials on the effects of weight loss and pharmacotherapy on obesity associated inflammatory and thrombotic markers linked with cardiovascular disease.

Interleukin-6 and silent cerebral infarction in hemodialysis patients: a cross-sectional study

BACKGROUND

In patients with chronic renal failure undergoing hemodialysis (HD), silent cerebral infarctions (SCI) are associated with high mortality. Levels of interleukin-6 (IL-6) increase with renal dysfunction and may be a novel predictor for cerebrovascular events. We tested the hypothesis that increased IL-6 levels correlate with the occurrence of SCI in HD patients.

METHODS

Using cranial magnetic resonance imaging findings, we divided 50 Japanese patients undergoing HD into two groups: with SCI (60 ± 7 years, mean ± SD, n = 27) and without SCI (60 ± 6 years, n = 23). We compared the gender, body mass index, metabolic profiles, IL-6 levels, and smoking habits between the two groups.

RESULTS

We made the following observations: (i) The prevalence of diabetes or hypertension did not differ between the two groups, (ii) the level of IL-6 was higher in the with-SCI group than in the without-SCI group (P < 0.0001), (iii) the proportion of smokers was higher in the with-SCI group (P < 0.05), (iv) plasma level of high-density lipoprotein cholesterol was lower, whilst uric acid level was higher, in the with-SCI group (P < 0.05 and P < 0.05, respectively), and (v) multiple logistic regression analysis identified IL-6 levels as being significantly associated with the presence of SCI (odds ratio 3.13, 95% CI = 1.42-7.89, P < 0.0001).

CONCLUSIONS

This study indicates that patients with chronic renal failure who are maintained on HD exhibit an increased prevalence of SCI and that IL-6 is significantly associated with the presence of SCI in HD patients.

Nitric oxide, NAD(P)H oxidase, and atherosclerosis

The endothelial cell layer plays a major role in the development and progression of atherosclerosis. Endothelial NO synthase (eNOS) produces nitric oxide (NO) from L-arginine. NO can rapidly react with reactive oxygen species to form peroxynitrite. This reduces NO availability, impairs vasodilatation, and mediates proinflammatory and prothrombotic processes such as leukocyte adhesion and platelet aggregation. In the vessel wall, specific NAD(P)H oxidase complexes are major sources of reactive oxygen species. These NAD(P)H oxidases can transfer electrons across membranes to oxygen and generate superoxide anions. The short-lived superoxide anion rapidly dismutates to hydrogen peroxide, which can further increase the production of reactive oxygen species. This can lead to uncoupling of eNOS switching enzymatic activity from NO to superoxide production. This review describes the structure and regulation of different NAD(P)H oxidase complexes. We will also focus on NO/superoxide anion balance as modulated by hemodynamic forces, vasoconstrictors, and oxidized low-density lipoprotein. We will then summarize the recent advances defining the role of nitric oxide and NAD(P)H oxidase-derived reactive oxygen species in the development and progression of atherosclerosis. In conclusion, novel mechanisms affecting the vascular NO/superoxide anion balance will allow the development of therapeutic strategies in the treatment of cardiovascular diseases.

The renin-angiotensin system modulates inflammatory processes in atherosclerosis: evidence from basic research and clinical studies

Recent evidence shows that the renin-angiotensin system is a crucial player in atherosclerotic processes. The regulation of arterial blood pressure was considered from its first description of the main mechanism involved. Vasoconstriction (mediated by angiotensin II) and salt and water retention (mainly due to aldosterone) were classically considered as pivotal proatherosclerotic activities. However, basic research and animal studies strongly support angiotensin II as a proinflammatory mediator, which directly induces atherosclerotic plaque development and heart remodeling. Furthermore, angiotensin II induces proatherosclerotic cytokine and chemokine secretion and increases endothelial dysfunction. Accordingly, the pharmacological inhibition of the renin-angiotensin system improves prognosis of patients with cardiovascular disease even in settings of normal baseline blood pressure. In the present review, we focused on angiotensin-convertingenzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), and renin inhibitors to update the direct activities of the renin-angiotensin system in inflammatory processes governing atherosclerosis.

Imidaprilat inhibits matrix metalloproteinase-2 activity in human cardiac fibroblasts induced by interleukin-1beta via NO-dependent pathway

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors are widely used in treatment of heart failure, but little is known regarding whether ACE inhibitors regulate the activity of matrix metalloproteinases (MMPs) and the tissue inhibitor of MMPs (TIMPs) in cardiac cells. The purpose of this study was to determine the ability and possible signal pathway involved of imidaprilat, an ACE inhibitor, to modulate MMP-2 and TIMP-2 in human cardiac fibroblasts in the presence of interleukin (IL)-1beta.

METHODS AND RESULTS

Using gelatin zymography and RT-PCR and Griess analysis,we found that IL-1beta increased the MMP-2 activity and transcription and nitric oxide(NO) production from supernatant of culture medium. These effects of IL-1beta were inhibited by imidaprilat or the NO synthase inhibitor, L-NMMA. Sodium nitroprusside (SNP), an exogenous NO donor, prevented significantly the effects of imidaprilat on MMP-2 inhibition. Imidaprilat alone didn't affect MMP-2 activity and expression. Neither IL-1beta nor imidaprilat has no effect on TIMP-2 transcription in cardiac fibroblasts.

CONCLUSIONS

The current study demonstrates imidaprilat inhibits MMP-2 activity and expression in human cardiac fibroblasts induced by IL-1beta via NO-dependent pathway. These data suggest that the beneficial effect of ACE inhibitors against left cardiac remodeling and heart failure may be due at least in part to regulating MMPs activity and expression by modulation of NO pathway.

Does the prevalence of nasal polyps increase in patients using statins?

Several statins inhibit T-helper 1 development and induce T-helper 2 polarization and production of T-helper 2 cytokines that promote the activation and chemotaxis of eosinophils. Whether statins promote the development of nasal polyps has so far been uncertain. No studies have evaluated the frequency of the development of nasal polyps in patients using statins. To better define the relationship of statin use to the presence of nasal polyps, the investigators explored the frequency of the development of nasal polyps in patients who were using statins. A total of 200 patients who were using statins and 200 who were not using statins (400 cases) were investigated. All patients were examined for nasal polyps by anterior rhinoscopy or investigation with a fiberoptic endoscope. In addition, immunoglobulin E levels were measured, a skin prick test was performed, and the results from the 2 groups were compared. Nasal polyps were detected in 4 subjects who were using statins, whereas 5 nasal polyps were found in the control group; differences between the 2 groups were statistically insignificant (P>.05). When the atopy status of the 2 groups was compared, prick test positivity and serum immunoglobulin E levels were found to be 15% and 44+/-31 IU/mL in the statin group and 19% and 68+/-23 IU/mL in the control group (P>.05). These results show that nasal polyposis is a multifactorial disease with several different causes; however, the frequency of the development of nasal polyps does not increase in patients who use statins.

Effects of an angiotensin-converting enzyme inhibitor (ramipril) on inflammatory markers in secondary prevention patients: RAICES Study

AIMS

To evaluate the hypothesis that angiotensin-converting enzyme inhibitor therapy with ramipril reduces baseline levels of C-reactive protein in patients at high cardiovascular risk.

METHODS

Secondary prevention patients were screened for eligibility and treated with ramipril for 6 month. Baseline and 6-month highly sensitive C-reactive protein levels were determined.

RESULTS

A total of 77 patients were analyzed. The median highly sensitive C-reactive protein concentration at baseline was 2.17 mg/l (interquartile interval 0.97-4.54); whereas in post-treatment, the median was 1.70 mg/l (interquartile interval 0.88-3.41), P=0.0009. Patients were stratified according to risk level determined by baseline highly sensitive C-reactive protein levels: low-risk (<1 mg/l), intermediate risk (1-3 mg/l) and high risk (>3 mg/l) The reduction in highly sensitive C-reactive protein occurred at the expense of the high-risk group (baseline 5.02 mg/l, post-treatment 3.3 mg/l, P<0.0001), with no differences in the other groups. In multiple regression analysis, the reduction observed in the high-risk group could not be explained by baseline treatment or change in any of the variables analyzed.

CONCLUSION

Highly sensitive C-reactive protein levels were reduced after a 6-month ramipril therapy in secondary prevention patients, suggesting an anti-inflammatory effect of angiotensin-converting enzyme inhibitors. Future investigations will be done to confirm these results, and to investigate how angiotensin-converting enzyme inhibitor treatment elicits anti-inflammatory effects.

Statins, fenofibrate, and quinapril increase clot permeability and enhance fibrinolysis in patients with coronary artery disease

BACKGROUND

Aspirin increases fibrin clot porosity and susceptibility to lysis. It is unknown whether other drugs, in combination with aspirin, used in the treatment of coronary artery disease (CAD) might affect clot structure and resistance to lysis.

AIM

The aim of the study was to assess the effects of statins, fibrates, or angiotensin-converting enzyme inhibitors (ACEIs) on fibrin clot properties.

PATIENTS AND METHODS

In a randomized double-blind study, men with advanced CAD taking low-dose aspirin were assigned to receive one of the four drugs: simvastatin 40 mg day(-1) (n = 13), atorvastatin 40 mg day(-1) (n = 12), fenofibrate 160 mg day(-1) (n = 12), and quinapril 10 mg day(-1) (n = 11) for 28 +/- 2 days. Moreover, CAD patients (n = 13) taking aspirin (75 mg day(-1)) for 8 weeks were studied after additional 4 weeks on an open-label basis. Thirty men served as healthy controls. Plasma clot permeability and tissue plasminogen activator-induced fibrinolysis were evaluated at baseline and after drug administration.

RESULTS

Permeability increased following the administration of simvastatin (by 20%; P = 0.01), atorvastatin (by 22%; P = 0.001), fenofibrate (by 16%; P = 0.02), and quinapril (by 13%; P = 0.04) like for aspirin (P < 0.001). Turbidity analysis showed that administration of any of the drugs was associated with higher maximum absorbancy, suggesting thicker fibers, and shorter fibrinolysis time (P < 0.001). Post-treatment reduction in lysis time correlated with an increase in clot porosity in all the groups (r from 0.42 to 0.61; P from 0.01 to 0.001).

CONCLUSIONS

Statins, fibrates, and ACEIs may increase plasma clot permeability and susceptibility to fibrinolysis in CAD patients receiving aspirin. This novel antithrombotic mechanism might contribute to clinical benefits of the drugs tested.

Treating the patient with kidney failure to reduce cardiovascular disease risk

The reduction of cardiovascular disease risk in kidney failure involves treatment of modifiable risk factors and provision of proven interventions to patients with established disease. Volume status management is key to blood pressure control. Statins are the agents of choice for the treatment of dyslipidemia. Target hemoglobin levels should be achieved using intravenous iron and erythropoietic agents. Combinations of calcium and noncalcium-containing phosphorus binders and vitamin D and its analogues should be used to attain target parathyroid hormone, phosphorus, and calcium phosphorus product levels. beta Blockers and aspirin are recommended in patients with ischemic heart disease and angiotensin-converting enzyme inhibitors (or angiotensin II receptor blockers), and beta blockers are recommended in patients with heart failure with reduced ejection fraction. In patients who require revascularization, studies suggest a survival benefit of coronary artery bypass graft surgery over percutaneous transluminal coronary angioplasty and coronary artery stenting.

Effect of administration of lovastatin on the development of late pulmonary effects after whole-lung irradiation in a murine model

Our group's work on late radiation effects has been governed by the hypothesis that the effects observed in normal tissues are a consequence of multicellular interactions through a network of mediators. Further, we believe that inflammation is a necessary component of this process. We therefore investigated whether the recruitment of mononuclear cells, observed during the pneumonitic period in the irradiated normal lung, is dependent on the expression of chemokines, notably Mcp1. Since statins have been shown to reduce chemokine expression and inflammatory cell recruitment, we specifically examined whether statins could be used to reduce monocyte recruitment. Mice received 15 Gy whole-lung irradiation; treated groups were administered lovastatin three times weekly starting either immediately or 8 weeks postirradiation. At subsequent intervals, animals were killed humanely, and cellular, mRNA and protein analyses were undertaken. Statin-treated animals demonstrated a statistically significant reduction in both macrophage and lymphocyte populations in the lung compared to radiation alone as well as improved rates of survival and decreased collagen content. In addition, ELISA measurements showed that radiation-induced increases in Mcp1 protein were reduced by statin treatment. Additional experiments are needed to assess whether statins offer a potential treatment for the amelioration of late effects in breast and lung cancer patients undergoing radiation therapy.

Nutrition and prevention of ischemic stroke: present knowledge, limitations and future perspectives

Stroke, particularly ischemic stroke, has a major impact on public health due to its high incidence, prevalence and rate of subsequent disability in Italy as in most industrialised countries. Apart from age, many modifiable factors, such as hypertension, smoking, diabetes, dyslipidemia, obesity, physical inactivity, alcohol abuse and hyperhomocysteinemia, have been recognised as playing a role in the pathogenesis of this disease. While appropriate pharmacological therapy has proven effective in the prevention of stroke in particular categories of patients, most of the above mentioned predisposing conditions are amenable to be affected by nutrition. Unequivocal demonstration of a protective or adverse role of single foods and nutrients against the risk of stroke has been however difficult to achieve due to confounding by biological variability, methodological inadequacies in the assessment of individual nutritional habits and difficulty to carry out long-term randomised controlled trials in the nutritional area. Notwithstanding, in several cases, causal relationships could be inferred from case-control and cohort studies in the presence of plausible and reproducible associations, evidence of dose-dependent effects and consistency in the results of different studies. The aim of this paper was to review present knowledge and highlight limitations and future perspectives about the role of nutrition in the prevention of ischemic stroke.

Lipaemia, Inflammation and Atherosclerosis

Atherosclerosis is the major cause of death in the world. Fasting and postprandial hyperlipidaemia are important risk factors for coronary heart disease (CHD). Recent developments have undoubtedly indicated that inflammation is pathophysiologically closely linked to atherogenesis and its clinical consequences. Inflammatory markers such as C-reactive protein (CRP), leucocyte count and complement component 3 (C3) have been linked to CHD and to hyperlipidaemia and several other CHD risk factors. Increases in these markers may result from activation of endothelial cells (CRP, leucocytes, C3), disturbances in adipose tissue fatty acid metabolism (CRP, C3), or from direct effects of CHD risk factors (leucocytes). It has been shown that lipoproteins, triglycerides, fatty acids and glucose can activate endothelial cells, most probably as a result of the production of reactive oxygen species. Similar mechanisms may also lead to leucocyte activation. Increases in triglycerides, fatty acids and glucose are common disturbances in the metabolic syndrome and are most prominent in the postprandial phase. People are in a postprandial state most of the day, and this phase is proatherogenic. Inhibition of the activation of leucocytes, endothelial cells, or both, is an interesting target for intervention, as activation is obligatory for adherence of leucocytes to the endothelium, thereby initiating atherogenesis. Potential interventions include the use of unsaturated long-chain fatty acids, polyphenols, antioxidants, angiotensin converting enzyme inhibitors and high-dose aspirin, which have direct anti-inflammatory and antiatherogenic effects. Furthermore, peroxisome proliferator activating receptor gamma (PPARgamma) agonists and statins have similar properties, which are in part independent of their lipid-lowering effects.

The VCAM-1 gene that encodes the vascular cell adhesion molecule is a target of the Sry-related high mobility group box gene, Sox18

VCAM-1 (vascular cell adhesion molecule-1) and Sox18 are involved in vascular development. VCAM-1 is an important adhesion molecule that is expressed on endothelial cells and has a critical role in endothelial activation, inflammation, lymphatic pathophysiology, and atherogenesis. The Sry-related high mobility group box factor Sox18 has previously been implicated in endothelial pathologies. Mutations in human and mouse Sox18 leads to hypotrichosis and lymphedema. Furthermore, both Sox18 and VCAM-1 have very similar spatio-temporal patterns of expression, which is suggestive of cross-talk. We use biochemical techniques, cell culture systems, and the ragged opossum (RaOP) mouse model with a naturally occurring mutation in Sox18 to demonstrate that VCAM-1 is an important target of Sox18. Transfection, site-specific mutagenesis, and gel shift analyses demonstrated that Sox18 directly targeted and trans-activated VCAM-1 expression. Importantly, the naturally occurring Sox18 mutant attenuates the expression and activation of VCAM-1 in vitro. Furthermore, in vivo quantitation of VCAM-1 mRNA levels in wild type and RaOP mice demonstrates that RaOP animals show a dramatic and significant reduction in VCAM-1 mRNA expression in lung, skin, and skeletal muscle. Our observation that the VCAM-1 gene is an important target of SOX18 provides the first molecular insights into the vascular abnormalities in the mouse mutant ragged and the human hypotrichosis-lymphedema-telangiectasia disorder.