The HMG-CoA reductase inhibitor rosuvastatin and the angiotensin receptor antagonist candesartan attenuate atherosclerosis in an apolipoprotein E-deficient mouse model of diabetes via effects on advanced glycation, oxidative stress and inflammation

Programmed death of macrophages in atherosclerosis: mechanisms and therapeutic targets

Atherosclerosis is a progressive inflammatory disorder of the arterial vessel wall characterized by substantial infiltration of macrophages, which exert both favourable and detrimental functions. Early in atherogenesis, macrophages can clear cytotoxic lipoproteins and dead cells, preventing cytotoxicity. Efferocytosis - the efficient clearance of dead cells by macrophages - is crucial for preventing secondary necrosis and stimulating the release of anti-inflammatory cytokines. In addition, macrophages can promote tissue repair and proliferation of vascular smooth muscle cells, thereby increasing plaque stability. However, advanced atherosclerotic plaques contain large numbers of pro-inflammatory macrophages that secrete matrix-degrading enzymes, induce death in surrounding cells and contribute to plaque destabilization and rupture. Importantly, macrophages in the plaque can undergo apoptosis and several forms of regulated necrosis, including necroptosis, pyroptosis and ferroptosis. Regulated necrosis has an important role in the formation and expansion of the necrotic core during plaque progression, and several triggers for necrosis are present within atherosclerotic plaques. This Review focuses on the various forms of programmed macrophage death in atherosclerosis and the pharmacological interventions that target them as a potential means of stabilizing vulnerable plaques and improving the efficacy of currently available anti-atherosclerotic therapies.

Regulated Necrosis in Atherosclerosis

During atherosclerosis, lipid-rich plaques are formed in large- and medium-sized arteries, which can reduce blood flow to tissues. This situation becomes particularly precarious when a plaque develops an unstable phenotype and becomes prone to rupture. Despite advances in identifying and treating vulnerable plaques, the mortality rate and disability caused by such lesions remains the number one health threat in developed countries. Vulnerable, unstable plaques are characterized by a large necrotic core, implying a prominent role for necrotic cell death in atherosclerosis and plaque destabilization. Necrosis can occur accidentally or can be induced by tightly regulated pathways. Over the past decades, different forms of regulated necrosis, including necroptosis, ferroptosis, pyroptosis, and secondary necrosis, have been identified, and these may play an important role during atherogenesis. In this review, we describe several forms of necrosis that may occur in atherosclerosis and how pharmacological modulation of these pathways can stabilize vulnerable plaques. Moreover, some challenges of targeting necrosis in atherosclerosis such as the presence of multiple death-inducing stimuli in plaques and extensive cross-talk between necrosis pathways are discussed. A better understanding of the role of (regulated) necrosis in atherosclerosis and the mechanisms contributing to plaque destabilization may open doors to novel pharmacological strategies and will enable clinicians to tackle the residual cardiovascular risk that remains in many atherosclerosis patients.

Pyk2/MCU Pathway as a New Target for Reversing Atherosclerosis

Objective: Multiple mechanisms including vascular endothelial cell damage have a critical role in the formation and development of atherosclerosis (AS), but the specific molecular mechanisms are not exactly clarified. This study aims to determine the possible roles of proline-rich tyrosine kinase 2 (Pyk2)/mitochondrial calcium uniporter (MCU) pathway in AS mouse model and H₂O₂-induced endothelial cell damage model and explore its possible mechanisms.

Approach and Results: The AS mouse model was established using apolipoprotein E-knockout (ApoE^–/–) mice that were fed with a high-fat diet. It was very interesting to find that Pyk2/MCU expression was significantly increased in the artery wall of atherosclerotic mice and human umbilical vein endothelial cells (HUVECs) attacked by hydrogen peroxide (H₂O₂). In addition, down-regulation of Pyk2 by short hairpin RNA (shRNA) protected HUVECs from H₂O₂ insult. Furthermore, treatment with rosuvastatin on AS mouse model and H₂O₂-induced HUVEC injury model showed a protective effect against AS by inhibiting the Pyk2/MCU pathway, which maintained calcium balance, prevented the mitochondrial damage and reactive oxygen species production, and eventually inhibited cell apoptosis.

Conclusion: Our results provide important insight into the initiation of the Pyk2/MCU pathway involved in AS-related endothelial cell damage, which may be a new promising target for atherosclerosis intervention.

Beneficial Effect of Statin Therapy on Arterial Stiffness

Arterial stiffness describes the increased rigidity of the arterial wall that occurs as a consequence of biological aging and several diseases. Numerous studies have demonstrated that parameters to assess arterial stiffness, especially pulse-wave velocity, are predictive of those individuals that will suffer cardiovascular morbidity and mortality. Statin therapy may be a pharmacological strategy to improve arterial elasticity. It has been shown that the positive benefits of statin therapy on cardiovascular disease is attributable not only to their lipid-lowering capacity but also to various pleiotropic effects, such as their anti-inflammatory, antiproliferative, antioxidant, and antithrombotic properties. Additionally, statins reduce endothelial dysfunction, improve vascular and myocardial remodeling, and stabilize atherosclerotic plaque. The aim of the present review was to summarize the evidence from human studies showing the effects of statins on arterial stiffness.

NADPH Oxidase Inhibition: Preclinical and Clinical Studies in Diabetic Complications

Significance: Oxidative stress plays a critical role in the development and progression of serious micro- and macrovascular complications of diabetes. Nicotinamide adenine dinucleotide phosphate oxidase (NOX)-derived reactive oxygen species (ROS) significantly contribute to oxidative stress-associated inflammatory pathways that lead to tissue damage of different organs, including the kidneys, retina, brain, nerves, and the cardiovascular system. Recent Advances: Preclinical studies, including genetic-modified mouse models or cell culture models, have revealed the role of specific NOX isoforms in different diabetic complications, and suggested them as a promising target for the treatment of these diseases. Critical Issues: In this review, we provide an overview of the role of ROS and oxidative stress in macrovascular complications, such as stroke, myocardial infarction, coronary artery disease, and peripheral vascular disease that are all mainly driven by atherosclerosis, as well as microvascular complications, such as diabetic retinopathy, nephropathy, and neuropathy. We summarize conducted genetic deletion studies of different Nox isoforms as well as pharmacological intervention studies using NOX inhibitors in the context of preclinical as well as clinical research on diabetic complications. Future Directions: We outline the isoforms that are most promising for future clinical trials in the context of micro- and macrovascular complications of diabetes.

Disparate Effects of Diabetes and Hyperlipidemia on Experimental Kidney Disease

It is well established that diabetes is the major cause of chronic kidney disease worldwide. Both hyperglycemia, and more recently, advanced glycation endproducts, have been shown to play critical roles in the development of kidney disease. Moreover, the renin-angiotensin system along with growth factors and cytokines have also been shown to contribute to the onset and progression of diabetic kidney disease; however, the role of lipids in this context is poorly characterized. The current study aimed to compare the effect of 20 weeks of streptozotocin-induced diabetes or western diet feeding on kidney disease in two different mouse strains, C57BL/6 mice and hyperlipidemic apolipoprotein (apo) E knockout (KO) mice. Mice were fed a chow diet (control), a western diet (21% fat, 0.15% cholesterol) or were induced with streptozotocin-diabetes (55 mg/kg/day for 5 days) then fed a chow diet and followed for 20 weeks. The induction of diabetes was associated with a 3-fold elevation in glycated hemoglobin and an increase in kidney to body weight ratio regardless of strain (p < 0.0001). ApoE deficiency significantly increased plasma cholesterol and triglyceride levels and feeding of a western diet exacerbated these effects. Despite this, urinary albumin excretion (UAE) was elevated in diabetic mice to a similar extent in both strains (p < 0.0001) but no effect was seen with a western diet in either strain. Diabetes was also associated with extracellular matrix accumulation in both strains, and western diet feeding to a lesser extent in apoE KO mice. Consistent with this, an increase in renal mRNA expression of the fibrotic marker, fibronectin, was observed in diabetic C57BL/6 mice (p < 0.0001). In summary, these studies demonstrate disparate effects of diabetes and hyperlipidemia on kidney injury, with features of the diabetic milieu other than lipids suggested to play a more prominent role in driving renal pathology.

Integral role of receptor for advanced glycation end products (RAGE) in nondiabetic atherosclerosis

An advanced glycation end products (AGE)/a receptor for AGE (RAGE) axis plays a central role in the pathogenesis of diabetic vascular remodeling. This study was conducted to clarify the role of RAGE in nondiabetic atherosclerosis. We used the aortic and coronary atherosclerotic lesions of Watanabe heritable hyperlipidemic (WHHL) rabbits prone to myocardial infarction (WHHLMI) at 1 to 14 months. Immunohistochemistry demonstrated the significant expression of RAGE as early as at 1 month with the stronger expression at 3 and 7 months, which was remarkably diminished at 14 months. RAGE expression was concordant with AGE accumulation. The major original sources of RAGE expression were macrophages and smooth muscle cells in addition to endothelial cells, and RAGE expression was distributed in the areas of phospholipid products, a component of oxidized LDL and nitrotyrosine. The concentrations of serum AGE did not alter significantly with aging. These findings suggested the expression of RAGE was induced by hyperlipidemia and oxidative stress independent of diabetes in WHHLMI rabbits. Additionally, our in vitro study showed that silencing of RAGE tended to attenuate oxidized-LDL-triggered PAI-1 expression in human cultured macrophages, as well as oxidized-LDL-induced tissue factor expression in peritoneal macrophages, suggesting a possible role of RAGE in prothrombogenic molecular regulation. In conclusion, the present study provides in vivo evidence that RAGE plays an integral role in the initiation and progression of nondiabetic atherosclerosis, suggesting that RAGE may be a novel target for treating not only diabetic but also nondiabetic vascular complications.

A simple, rapid and fully validated HPLC method for simultaneous quantitative bio-analysis of rosuvastatin and candesartan in rat plasma: Application to pharmacokinetic interaction study

A simple, precise and accurate HPLC method was developed, optimized and validated for simultaneous determination of rosuvastatin and candesartan in rat plasma using atorvastatin as an internal standard. Solid-phase extraction was used for sample cleanup and its subsequent optimization was carried out to achieve higher extraction efficiency and to eliminate matrix effect. A quality by design approach was used, wherein three-level factorial design was applied for optimization of mobile phase composition and for assessing the effect of pH of the mobile phase using Design Expert Software. Adequate separation for both analytes was achieved with a Waters C₁₈ column (250 × 4.6 mm, 5 μm) using acetonitrile-5 mm sodium acetate buffer (70:30, v/v; pH adjusted to 3.5 with acetic acid) as a mobile phase at a flow rate of 1.0 mL/min and wavelength of 254 nm. The calibration curves were linear over the concentration ranges 5-150 and 10-300 ng/mL for rosuvastatin (ROS) and candesartan (CAN), respectively. The validated method was successfully applied to a pharmacokinetic study in Wistar rats and the data did not reveal any evidence for a potential drug-drug interaction between ROS and CAN. This information provides evidence for clinical rational use of ROS and CAN.

Macrophage Death as a Pharmacological Target in Atherosclerosis

Atherosclerosis is a chronic inflammatory disorder characterized by the gradual build-up of plaques within the vessel wall of middle-sized and large arteries. Over the past decades, treatment of atherosclerosis mainly focused on lowering lipid levels, which can be accomplished by the use of statins. However, some patients do not respond sufficiently to statin therapy and therefore still have a residual cardiovascular risk. This issue highlights the need for novel therapeutic strategies. As macrophages are implicated in all stages of atherosclerotic lesion development, they represent an important alternative drug target. A variety of anti-inflammatory strategies have recently emerged to treat or prevent atherosclerosis. Here, we review the canonical mechanisms of macrophage death and their impact on atherogenesis and plaque stability. Macrophage death is a prominent feature of advanced plaques and is a major contributor to necrotic core formation and plaque destabilization. Mechanisms of macrophage death in atherosclerosis include apoptosis, passive or accidental necrosis as well as secondary necrosis, a type of death that typically occurs when apoptotic cells are insufficiently cleared by neighboring cells via a phagocytic process termed efferocytosis. In addition, less-well characterized types of regulated necrosis in macrophages such as necroptosis, pyroptosis, ferroptosis, and parthanatos may occur in advanced plaques and are also discussed. Autophagy in plaque macrophages is an important survival pathway that protects against cell death, yet massive stimulation of autophagy promotes another type of death, usually referred to as autosis. Multiple lines of evidence indicate that a better insight into the different mechanisms of macrophage death, and how they mutually interact, will provide novel pharmacological strategies to resolve atherosclerosis and stabilize vulnerable, rupture-prone plaques.

Glycation and HMG-CoA Reductase Inhibitors: Implication in Diabetes and Associated Complications

INTRODUCTION

Diabetes Mellitus (DM) acts as an absolute mediator of cardiovascular risk, prompting the prolonged occurrence, size and intricacy of atherosclerotic plaques via enhanced Advanced Glycation Endproducts (AGEs) formation. Moreover, hyperglycemia is associated with enhanced glyco-oxidized and oxidized Low-Density Lipoprotein (LDL) possessing greater atherogenicity and decreased the ability to regulate HMG-CoA reductase (HMG-R). Although aminoguanidine (AG) prevents the AGE-induced protein cross-linking due to its anti-glycation potential, it exerts several unusual pharmaco-toxicological effects thus restraining its desirable therapeutic effects. HMG-R inhibitors/ statins exhibit a variety of beneficial impacts in addition to the cholesterol-lowering effects.

OBJECTIVE

Inhibition of AGEs interaction with receptor for AGEs (RAGE) and glyco-oxidized-LDL by HMG-R inhibitors could decrease LDL uptake by LDL-receptor (LDL-R), regulate cholesterol synthesis via HMG-R, decrease oxidative and inflammatory stress to improve the diabetes-associated complications.

CONCLUSION

Current article appraises the pathological AGE-RAGE concerns in diabetes and its associated complications, mainly focusing on the phenomenon of both circulatory AGEs and those accumulating in tissues in diabetic nephropathy, diabetic neuropathy, and diabetic retinopathy, discussing the potential protective role of HMG-R inhibitors against diabetic complications.

Rosuvastatin stabilizes atherosclerotic plaques by reducing CD40L overexpression-induced downregulation of P4Hα1 in ApoE-/- mice

Background Cluster of differentiation 40 ligand (CD40L) and rosuvastatin (RSV) affect atherosclerotic plaque stability, but little is known about their roles in extracellular matrix (ECM) production. We investigated the effects of CD40L and RSV on pre-existing advanced plaques. Methods and results Pre-existing advanced plaques were induced in apolipoprotein E-knockout (ApoE^-/-) mice by the surgical placement of carotid constrictive silastic collars. Two weeks after surgery, mice were divided into the following treatment groups: control, empty adenovirus, CD40L adenovirus, CD40L adenovirus + RSV, and RSV. Mice received adenovirus via two tail-vein injections (2 × 10⁹ pfu each) and/or RSV via intragastric administration (5 mg/kg; daily for 4 weeks). Mice in the CD40L adenovirus group exhibited increased plaque disruption rates, increased relative plaque macrophage and lipid content, reduced plaque collagen content, and increased local inflammation compared to the other treatment groups, but no significant differences in plaque area were observed among the groups. Notably, in the atherosclerotic plaques of the CD40L adenovirus group, both the mRNA and protein expression of prolyl-4-hydroxylase alpha 1 (P4Hα1) was significantly decreased, leading to a consequent decrease in the protein expression of collagen types I and III. Treatment with RSV decreased the serum levels of CD40L in a lipid-independent fashion and attenuated the effects of CD40L overexpression, particularly with respect to P4Hα1 downregulation. Conclusions CD40L destabilized advanced plaques in the carotid arteries of ApoE^-/- mice, in part by decreasing P4Hα1 expression, and consequently collagen expression. These destabilizing effects were attenuated by RSV.

A causal link between oxidative stress and inflammation in cardiovascular and renal complications of diabetes

Chronic renal and vascular oxidative stress in association with an enhanced inflammatory burden are determinant processes in the development and progression of diabetic complications including cardiovascular disease (CVD), atherosclerosis and diabetic kidney disease (DKD). Persistent hyperglycaemia in diabetes mellitus increases the production of reactive oxygen species (ROS) and activates mediators of inflammation as well as suppresses antioxidant defence mechanisms ultimately contributing to oxidative stress which leads to vascular and renal injury in diabetes. Furthermore, there is increasing evidence that ROS, inflammation and fibrosis promote each other and are part of a vicious connection leading to development and progression of CVD and kidney disease in diabetes.

RAGE and TLRs as Key Targets for Antiatherosclerotic Therapy

Receptor for advanced glycation end-products (RAGE) and toll-like receptors (TLRs) are the key factors indicating a danger to the organism. They recognize the microbial origin pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs). The primary response induced by PAMPs or DAMPs is inflammation. Excessive stimulation of the innate immune system occurs in arterial wall with the participation of effector cells. Persistent adaptive responses can also cause tissue damage and disease. However, inflammation mediated by the molecules innate responses is an important way in which the adaptive immune system protects us from infection. The specific detection of PAMPs and DAMPs by host receptors drives a cascade of signaling that converges at nuclear factor-κB (NF-κB) and interferon regulatory factors (IRFs) and induces the secretion of proinflammatory cytokines, type I interferon (IFN), and chemokines, which promote direct killing of the pathogen. Therefore, signaling of these receptors' pathways also appear to present new avenue for the modulation of inflammatory responses and to serve as potential novel therapeutic targets for antiatherosclerotic therapy.

Abundance, localization, and functional correlates of the advanced glycation end-product carboxymethyl lysine in human myocardium

Advanced glycation end‐products (AGEs) play a role in the pathophysiology of diabetes mellitus (DM) and possibly hypertension (HTN). In experimental DM, AGEs accumulate in myocardium. Little is known about AGEs in human myocardium. We quantified abundance, localization, and functional correlates of the AGE carboxymethyl lysine (CML) in left ventricular (LV) myocardium from patients undergoing coronary bypass grafting (CBG). Immunoelectron microscopy was used to quantify CML in epicardial biopsies from 98 patients (71 M, 27 F) with HTN, HTN + DM or neither (controls), all with normal LV ejection fraction. Myofilament contraction‐relaxation function was measured in demembranated myocardial strips. Echocardiography was used to quantify LV structure and function. We found that CML was abundant within cardiomyocytes, but minimally associated with extracellular collagen. CML counts/μm² were 14.7% higher in mitochondria than the rest of the cytoplasm (P < 0.001). There were no significant sex or diagnostic group differences in CML counts [controls 45.6 ± 3.6/μm² (±SEM), HTN 45.8 ± 3.6/μm², HTN + DM 49.3 ± 6.2/μm²; P = 0.85] and no significant correlations between CML counts and age, HgbA1c or myofilament function indexes. However, left atrial volume was significantly correlated with CML counts (r = 0.41, P = 0.004). We conclude that in CBG patients CML is abundant within cardiomyocytes but minimally associated with collagen, suggesting that AGEs do not directly modify the stiffness of myocardial collagen. Coexistent HTN or HTN + DM do not significantly influence CML abundance. The correlation of CML counts with LAV suggests an influence on diastolic function independent of HTN, DM or sex whose mechanism remains to be determined.

Prognostic impact of intensive statin therapy on N-terminal pro-BNP level in non-ST-segment elevation acute myocardial infarction patients

OBJECTIVE

This study explored the impact of intensive daily dosing of atorvastatin on in-hospital N-terminal pro-B-type natriuretic peptide level, left ventricular systolic function and incidence of major adverse cardiac events in non-ST-segment elevation myocardial infarction patients.

BACKGROUND

Several studies showed that early initiation of statin therapy in acute coronary syndrome patients has a favorable prognostic impact.

METHODS

Hundred statin naive patients were prospectively enrolled. Once eligible, patients were randomly assigned to receive either a moderate daily dose that is, 20 mg (Group A) or an intensified daily dose that is, 80 mg (Group B) of atorvastatin, in addition to an equally divided loading dose given 24 and 12 h before coronary angiography (80 mg each). N-terminal pro-B-type natriuretic peptide levels were recorded before and after coronary intervention. Collected data after 3 months included; N-terminal pro-B-type natriuretic peptide levels, left ventricle systolic function and major adverse cardiac events.

RESULTS

Mean age of the study cohort was 55 ± 10 years, 68% being males. There was no significant difference between both groups concerning procedural data. Group B patients showed a significantly lower N-terminal pro-B-type natriuretic peptide levels at both sampling occasions, i.e., after coronary intervention and 3 months later (P < 0.001). After 3 months, the same group showed higher left ventricle ejection fraction (P < 0.05), with no significant difference between both groups regarding incidence of major adverse cardiac events.

CONCLUSION

Intensive atorvastatin therapy in non-ST-segment elevation myocardial infarction patients undergoing percutaneous coronary intervention is associated with; lower in-hospital N-terminal pro BNP level and higher LVEF after 3 months.

Glycated albumin induces lipid infiltration in mice aorta independently of DM and RAS local modulation by inducing lipid peroxidation and inflammation

AIMS

Advanced glycated albumin (AGE-albumin) adversely impairs macrophage lipid homeostasis in vitro, which may be prevented by angiotensin receptor blockers. In vivo studies are inconclusive whether AGE-albumin itself plays important role in early-stage atherogenesis. We aimed at investigating how AGE-albumin by itself drives atherosclerosis development in dyslipidemic non-diabetic mice and if its effects are due to the activation of renin-angiotensin system in the arterial wall and the expression of genes and proteins involved in lipid flux.

METHODS AND RESULTS

Murine albumin glycation was induced by incubation with 10mM glycolaldehyde and C-albumin with PBS alone. Twelve-week-old-male apoE knockout mice were submitted to a daily IP injection of control (C) or AGE-albumin (2mg/mL) during 30days with or without losartan (LOS: 100mg/L; C+LOS and AGE+LOS). Aortic arch was removed, and gene expression was determined by RT-PCR and protein content by immunofluorescence. Plasma lipid and glucose levels were similar among groups. Systolic blood pressure was similarly reduced in both groups treated with LOS. In comparison to C-albumin, aortic lipid infiltration was 5.3 times increased by AGE-albumin, which was avoided by LOS. LOS prevented the enhancement induced by AGE-albumin in Ager, Tnf and Cybb mRNA levels but did not reduce Olr1. Nfkb and Agt mRNA levels were unchanged by AGE-albumin. LOS similarly reduced Agtr1a mRNA level in both C and AGE-albumin groups. In AGE-albumin-treated mice, immunofluorescence for carboxymethyl-lysine, 4-hydroxynonenal and RAGE was respectively, 4.8, 2.6 and 1.7 times enhanced in comparison to C-albumin. These increases were all avoided by LOS.

CONCLUSIONS

AGE-albumin evokes a pre-stage of atherogenesis in dyslipidemic mice independently of the presence of diabetes mellitus or modulation in the RAS in part by the induction of lipid peroxidation and inflammation.

Differences in peripheral oxidative stress markers in Alzheimer's disease, vascular dementia and mixed dementia patients

AIMS

We determined whether the possible roles of oxidative stress differ in the pathophysiology and cognitive decline of Alzheimer's disease (AD), vascular dementia (VaD) and mixed Alzheimer's/vascular dementia (MD).

METHODS

We measured the levels of diacron reactive oxygen metabolite (dROM), reflecting the amount of organic hydroperoxides, and biological anti-oxidant potential (BAP), measuring the ferric reducing ability of blood plasma, in 72 patients with AD, 27 with VaD, 24 with MD and 53 non-demented outpatients (control group). In addition, endogenous plasma anti-oxidants, such as albumin, total bilirubin and uric acid, were compared among the groups. All participants with VaD and MD showed extensive white matter hyperintensity, in addition to multiple lacunes.

RESULTS

The dROM levels were significantly higher in the AD and MD groups than in the control group. The BAP levels were significantly lower in the MD group than in the control, AD and VaD groups. The AD group showed significantly lower levels of bilirubin and uric acid than the control group. The MD group showed a significantly lower level of albumin than the control and AD groups, and a significantly lower level of bilirubin than the control group. The Mini-Mental State examination scores correlated significantly with dROM levels and BAP/dROM ratios in the AD group.

CONCLUSIONS

An imbalance in pro-oxidant and anti-oxidant defenses is apparently involved in the pathophysiology of the AD and MD groups. The extent of oxidative stress damage might differ in subtypes of dementia by being greater in the MD group than in other types of dementia. Synergic effects of the degenerative element of AD and white matter lesions might be associated with oxidative stress damage in the MD group.

Oxidative stress and inflammation are associated with physical frailty in patients with Alzheimer's disease

AIMS

Dementia is closely connected with frailty, and these two conditions are common in older adults. However, the biological mechanism that causes frailty in patients with Alzheimer's disease (AD) is not fully understood. We determined whether oxidative stress and inflammatory mechanisms could be associated with physical frailty in patients with AD.

METHODS

We studied 140 elderly outpatients with mild-to-moderate AD. Frailty status was determined according to the presence of the following five measurable characteristics: weight loss, exhaustion, low physical activity, slowness and weakness. We measured oxidative stress markers, including plasma levels of diacron reactive oxygen metabolite and biological anti-oxidant potential, endogenous plasma anti-oxidants, such as albumin, bilirubin and uric acid, and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-epiPGF2α (8-isoprostane), and inflammatory markers, including interleukin-6 and tumor necrosis factor-α.

RESULTS

Among patients, 44 (31%) were non-frail, 62 (44%) were prefrail and 34 (24%) were frail. Frail and prefrail patients were older, more likely to be women and had more comorbid medical conditions than non-frail patients. Frail or prefrail patients showed significantly higher diacron reactive oxygen metabolite and lower biological anti-oxidant potential levels, a significant decrease in bilirubin, a significant increase in urinary 8-OHdG and 8-isoprostane levels, and a significantly higher interleukin-6 level, in contrast to non-frail patients.

CONCLUSIONS

Physical frailty is common in old and female AD patients with comorbid medical diseases. The present results strongly suggest that oxidative stress and inflammation are involved in the pathophysiology of frailty status in individuals with AD. Geriatr Gerontol Int 2017; 17: 913-918.

Damaging effects of hyperglycemia on cardiovascular function: spotlight on glucose metabolic pathways

The incidence of cardiovascular complications associated with hyperglycemia is a growing global health problem. This review discusses the link between hyperglycemia and cardiovascular diseases onset, focusing on the role of recently emerging downstream mediators, namely, oxidative stress and glucose metabolic pathway perturbations. The role of hyperglycemia-mediated activation of nonoxidative glucose pathways (NOGPs) [i.e., the polyol pathway, hexosamine biosynthetic pathway, advanced glycation end products (AGEs), and protein kinase C] in this process is extensively reviewed. The proposal is made that there is a unique interplay between NOGPs and a downstream convergence of detrimental effects that especially affect cardiac endothelial cells, thereby contributing to contractile dysfunction. In this process the AGE pathway emerges as a crucial mediator of hyperglycemia-mediated detrimental effects. In addition, a vicious metabolic cycle is established whereby hyperglycemia-induced NOGPs further fuel their own activation by generating even more oxidative stress, thereby exacerbating damaging effects on cardiac function. Thus NOGP inhibition, and particularly that of the AGE pathway, emerges as a novel therapeutic intervention for the treatment of cardiovascular complications such as acute myocardial infarction in the presence hyperglycemia.

Intensive Statin Therapy in NSTE-ACS Patients Undergoing PCI: Clinical and Biochemical Effects

Early initiation of statin therapy in acute coronary syndrome patients has a favorable prognostic impact because of its anti-inflammatory and antithrombotic properties. In this study, we explored the effect of atorvastatin-loading, followed by intensive atorvastatin therapy, on clinical and biochemical outcomes in non-ST-segment-elevation acute coronary syndrome patients who were scheduled for percutaneous coronary intervention. We prospectively enrolled 140 patients (mean age, 56 ± 9 years, 68% men). Once eligible, patients were randomly assigned to receive either a moderate 20-mg daily dose of atorvastatin (Group A) or a 160-mg loading dose followed by an intensified 80-mg daily dose (Group B). High-sensitivity C-reactive protein (hs-CRP) levels were recorded before and after intervention. Evaluation after 6 months included hs-CRP levels, left ventricular systolic function, and major adverse cardiac events. We found no significant difference between the 2 groups in regard to the interventional data. However, blood sampling after coronary intervention, and again 6 months later, revealed a significant decline in mean hs-CRP level among Group B patients (P < 0.001). Moreover, patients in Group B manifested a higher left ventricular ejection fraction than did patients in Group A (P < 0.05). After 6 months, we found no significant difference between groups in the incidence of major adverse cardiac events. We conclude that intensive atorvastatin therapy in non-ST-segment-elevation acute coronary syndrome patients is associated with lower hs-CRP levels and with higher left ventricular ejection fraction after 6 months, with no significant impact on adverse cardiac events.

Atorvastatin delays the glucose clearance rate in hypercholesterolemic rabbits

The administration of statin might increase the risk of new-onset diabetes in hypercholesterolemic patients based on the recent clinical evidence. However, the causal relationship must be clarified and confirmed in animal experiments. Therefore, we mimicked hypercholesterolemia by feeding rabbits a high-cholesterol diet (HCD) and performed 16 weeks of atorvastatin administration to investigate the effect of statin on glucose metabolism. The intravenous glucose tolerance test showed that plasma glucose levels in the statin-treated rabbits were consistently higher and that there was a slower rate of glucose clearance from the blood than in HCD rabbits. The incremental area under the curve for glucose in the statin-treated rabbits was also significantly larger than in the HCD rabbits. However, there was no significant difference between the two groups in the intravenous insulin tolerance test. The glucose-lowering ability of exogenous insulin was not impaired by statin treatment in hypercholesterolemic rabbits. The administration of a single dose of statin did not affect glucose metabolism in normal rabbits. The statin also significantly increased the levels of high-density lipoprotein cholesterol, alanine aminotransferase and aspartate transaminase and decreased plasma levels of total cholesterol, triglycerides and low-density lipoprotein cholesterol in the hypercholesterolemic rabbits, whereas it did not affect plasma levels of glucose and insulin. The current results showed that atorvastatin treatment resulted in a significant delay of glucose clearance in hypercholesterolemic rabbits, and this rabbit model could be suitable for studying the effects of statin on glucose metabolism.

Rosuvastatin prevents angiotensin II-induced vascular changes by inhibition of NAD(P)H oxidase and COX-1

BACKGROUND AND PURPOSE

NAD(P)H oxidase and COX-1 participate in vascular damage induced by angiotensin II. We investigated the effect of rosuvastatin on endothelial dysfunction, vascular remodelling, changes in extracellular matrix components and mechanical properties of small mesenteric arteries from angiotensin II-infused rats.

EXPERIMENTAL APPROACH

Male rats received angiotensin II (120 ng·kg⁻¹ ·min⁻¹ , subcutaneously) for 14 days with or without rosuvastatin (10 mg·kg⁻¹ ·day⁻¹ , oral gavage) or vehicle. Vascular functions and morphological parameters were assessed by pressurized myography.

KEY RESULTS

In angiotensin II-infused rats, ACh-induced relaxation was attenuated compared with controls, less sensitive to L-NAME, enhanced by SC-560 (COX-1 inhibitor) or SQ-29548 (prostanoid TP receptor antagonist), and normalized by the antioxidant ascorbic acid or NAD(P)H oxidase inhibitors. After rosuvastatin, relaxations to ACh were normalized, fully sensitive to L-NAME, and no longer affected by SC-560, SQ-29548 or NAD(P)H oxidase inhibitors. Angiotensin II enhanced intravascular superoxide generation, eutrophic remodelling, collagen and fibronectin depositions, and decreased elastin content, resulting in increased vessel stiffness. All these changes were prevented by rosuvastatin. Angiotensin II increased phosphorylation of NAD(P)H oxidase subunit p47phox and its binding to subunit p67phox, effects inhibited by rosuvastatin. Rosuvastatin down-regulated vascular Nox4/NAD(P)H isoform and COX-1 expression, attenuated the vascular release of 6-keto-PGF1α , and enhanced copper/zinc-superoxide dismutase expression.

CONCLUSION AND IMPLICATIONS

Rosuvastatin prevents angiotensin II-induced alterations in resistance arteries in terms of function, structure, mechanics and composition. These effects depend on restoration of NO availability, prevention of NAD(P)H oxidase-derived oxidant excess, reversal of COX-1 induction and its prostanoid production, and stimulation of endogenous vascular antioxidant defences.

NAD(P)H oxidase isoforms as therapeutic targets for diabetic complications

The development of macro- and microvascular complications is accelerated in diabetic patients. While some therapeutic regimes have helped in delaying progression of complications, none have yet been able to halt the progression and prevent vascular disease, highlighting the need to identify new therapeutic targets. Increased oxidative stress derived from the NADPH oxidase (Nox) family has recently been identified to play an important role in the pathophysiology of vascular disease. In recent years, specific Nox isoforms have been implicated in contributing to the development of atherosclerosis of major vessels, as well as damage of the small vessels within the kidney and the eye. With the use of novel Nox inhibitors, it has been demonstrated that these complications can be attenuated, indicating that targeting Nox derived oxidative stress holds potential as a new therapeutic strategy.

Skin autofluorescence is associated with 5-year mortality and cardiovascular events in patients with peripheral artery disease

OBJECTIVE

Advanced glycation end products play a pivotal role in atherosclerosis. Recently, we showed that tissue advanced glycation end products deposition, noninvasively assessed by skin autofluorescence (SAF), is increased in patients with peripheral artery disease. The aim of the present study was to establish whether SAF is associated with all-cause mortality and with fatal or nonfatal major adverse cardiovascular events (MACE) in patients with peripheral artery disease.

APPROACH AND RESULTS

We performed a single-center prospective cohort study of 252 patients with peripheral artery disease (mean age, 66±11 years), recruited from the outpatient clinic (October 2007 to June 2008) who were followed until June 2013. SAF was measured with the AGE Reader. The primary end point was all-cause mortality, and the secondary end point was fatal or nonfatal MACE, defined as cardiovascular death and nonfatal myocardial infarction or stroke. During a median follow-up of 5.1 (interquartile range, 5.0-5.3) years, 62 (25%) patients died. Fatal or nonfatal MACE occurred in 62 (25%) patients. A higher SAF was associated with increased risk for all-cause mortality (hazard ratio per unit increase, 2.01; 95% confidence interval, 1.40-2.88; P=0.0002) and fatal or nonfatal MACE (hazard ratio, 1.82; 95% confidence interval, 1.28-2.60; P=0.001), also after adjustment for cardiovascular risk factors and the use of lipid-lowering drugs (hazard ratio, 1.63; 95% confidence interval, 1.13-2.34; P=0.009 and hazard ratio, 1.50; 95% confidence interval, 1.04-2.17; P=0.03, for all-cause mortality and fatal and nonfatal MACE, respectively).

CONCLUSIONS

SAF as a measure of advanced glycation end products deposition is independently associated with all-cause mortality and fatal or nonfatal MACE in patients with peripheral artery disease after a 5-year follow-up.

Atorvastatin inhibits the expression of RAGE induced by advanced glycation end products on aortas in healthy Sprague-Dawley rats

BACKGROUND

Atorvastatin can downregulate the expression of receptor for advanced glycation end products (RAGE) in the aortas of diabetic rats. However, its effect on healthy rats remains unclear. The aim of this study was to observe the direct impact of atorvastatin on advanced glycation end products- (AGEs) induced RAGE expression in healthy Sprague Dawley (SD) rats.

METHODS

SD rats received AGE-BSA (20 mg/kg/day or 40 mg/kg/day), dual treatment (AGE-BSA 40 mg/kg/day and atorvastatin 20 mg/kg/day) or no treatment for 12 and 24 weeks, respectively. The deposition of AGEs and expression of RAGE in the animals' aortas were assessed by Quantitative RT-PCR, immunohistochemistry, and western-blot tests. Serum levels of AGEs were measured using ELISA.

RESULTS

AGE-BSA upregulated the serum level of AGEs, deposition of AGEs, and expression of RAGE in aortas in a time- and dose-dependent way that can accelerate the development and progression of atherosclerosis. These upregulations could be significantly attenuated by atorvastatin in the absence of its lipid-lowering effects. These data provide further evidence for the novo mechanism of atorvastatin's pleiotropic effect.

CONCLUSION

Atorvastatin has a direct inhibitory effect on AGEs-RAGE expression in healthy SD rats. These potential pleiotropic vasculoprotective effects are independent of effects on glucose and lipid control.

Potential of the angiotensin receptor blockers (ARBs) telmisartan, irbesartan, and candesartan for inhibiting the HMGB1/RAGE axis in prevention and acute treatment of stroke

Stroke is a major cause of mortality and disability worldwide. The main cause of stroke is atherosclerosis, and the most common risk factor for atherosclerosis is hypertension. Therefore, antihypertensive treatments are recommended for the prevention of stroke. Three angiotensin receptor blockers (ARBs), telmisartan, irbesartan and candesartan, inhibit the expression of the receptor for advanced glycation end-products (RAGE), which is one of the pleiotropic effects of these drugs. High mobility group box 1 (HMGB1) is the ligand of RAGE, and has been recently identified as a lethal mediator of severe sepsis. HMGB1 is an intracellular protein, which acts as an inflammatory cytokine when released into the extracellular milieu. Extracellular HMGB1 causes multiple organ failure and contributes to the pathogenesis of hypertension, hyperlipidemia, diabetes mellitus, atherosclerosis, thrombosis, and stroke. This is the first review of the literature evaluating the potential of three ARBs for the HMGB1-RAGE axis on stroke therapy, including prevention and acute treatment. This review covers clinical and experimental studies conducted between 1976 and 2013. We propose that ARBs, which inhibit the HMGB1/RAGE axis, may offer a novel option for prevention and acute treatment of stroke. However, additional clinical studies are necessary to verify the efficacy of ARBs.

Simvastatin suppresses vascular inflammation and atherosclerosis in ApoE(-/-) mice by downregulating the HMGB1-RAGE axis

AIM

High mobility group box protein 1 (HMGB1) and receptor for the advanced glycation end product (RAGE) play pivotal roles in vascular inflammation and atherosclerosis. The aim of this study was to determine whether the HMGB1-RAGE axis was involved in the actions of simvastatin on vascular inflammation and atherosclerosis in ApoE(-/-) mice.

METHODS

Five-week old ApoE(-/-) mice and wild-type C57BL/6 mice were fed a Western diet. At 8 weeks of age, ApoE(-/-) mice were administered simvastatin (50 mg·kg(-1)·d(-1)) or vehicle by gavage, and the wild-type mice were treated with vehicle. The mice were sacrificed at 11 weeks of age, and the atherosclerotic lesions in aortic sinus were assessed with Oil Red O staining. Macrophage migration was determined with scanning EM and immunohistochemistry. Human umbilical vein endothelial cells (HUVECs) were used for in vitro study. Western blots were used to quantify the protein expression of HMGB1, RAGE, vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemoattractant protein-1 (MCP-1).

RESULTS

Vehicle-treated ApoE(-/-) mice exhibited significant increases in aortic inflammation and atherosclerosis as well as enhanced expression of HMGB1, RAGE, VCAM-1, and MCP-1 in aortic tissues as compared to the wild-type mice. Furthermore, serum total cholesterol, triglyceride and LDL levels were markedly increased, while serum HDL level was decreased in vehicle-treated ApoE(-/-) mice. Administration with simvastatin in ApoE(-/-) mice markedly attenuated the vascular inflammation and atherosclerotic lesion area, and decreased the aortic expression of HMGB1, RAGE, VCAM-1, and MCP-1. However, simvastatin did not affect the abnormal levels of serum total cholesterol, triglyceride, LDL and HDL in ApoE(-/-) mice. Exposure of HUVECs to HMGB1 (100 ng/mL) markedly increased the expression of HMGB1, RAGE and VCAM-1, whereas pretreatment of the cells with simvastatin (10 μmol/L) blocked the HMGB1-caused changes.

CONCLUSION

Simvastatin inhibits vascular inflammation and atherosclerosis in ApoE(-/-) mice, which may be mediated through downregulation of the HMGB1-RAGE axis.

Statins modulate feedback regulation mechanisms between advanced glycation end-products and C-reactive protein: evidence in patients with acute myocardial infarction

OBJECTIVE

High sensitivity C-reactive protein (hsCRP) and advanced glycation end-products (AGEs) have been proposed as mediators in inflammation and atherosclerosis. Therefore, we studied the relation between AGE and hsCRP in patients with acute myocardial infarction (AMI).

METHODS

Patients with AMI diagnosis and satisfying our inclusion criteria were included during 2009-2011 in an unicentre registry of AMI patients for a cross-sectional study. The final cohort was composed of 156 patients (46.2% STEMI and 27.6% with type-2 diabetes). AGE and hsCRP were measured in plasma.

RESULTS

Diabetic patients were older than non-diabetics (68.6 ± 10.6 vs. 60.4 ± 13.9 years; p<0.05), presented more incidence of hypertension (62.8 vs. 36.3%; p<0.05) and were in a higher Killip class (p<0.05). The mean values of fluorescent AGE and hsCRP levels were 61.3 ± 49.8 AU and 2.4 ± 4.0 mg/L, respectively, and there were no differences in these parameters between diabetic and non-diabetic patients. A direct association between AGE and hsCRP levels was observed, mainly in diabetic patients (r=0.258; p=0.018). Importantly, this association disappeared in patients who had been treated with statins before their AMI (r=-0.055; p=0.845), but it was maintained in non-diabetic patients naïve for statins treatment (r=0.634; p<0.001), independently of other treatments and confounding parameters.

CONCLUSIONS

This is the first evidence in humans of a feedback regulation mechanism between CRP and the AGE-RAGE axis modulated by statins.

Rosuvastatin reduced deep vein thrombosis in ApoE gene deleted mice with hyperlipidemia through non-lipid lowering effects

INTRODUCTION

Statins, particularly rosuvastatin, have recently become relevant in the setting of venous thrombosis. The objective of this study was to study the non-lipid lowering effects of rosuvastatin in venous thrombosis in mice with hyperlipidemia.

MATERIALS AND METHODS

An inferior vena cava ligation model of venous thrombosis in mice was utilized. Saline or 5mg/kg of rosuvastatin was administered by gavage 48hs previous to thrombosis. Blood, the inferior vena cava, thrombus, and liver were harvested 3, 6hours, and 2days post-thrombosis. Thrombus weight, inflammatory markers, and plasminogen activator inhibitor-1 expression and plasma levels were measured. Also, neutrophil migration to the IVC was assessed.

RESULTS

Rosuvastatin significantly decreased thrombus weight, plasminogen activator inhibitor-1 expression and plasma levels, expression of molecules related to the interleukin-6 pathway, and neutrophil migration into the vein wall.

CONCLUSIONS

This work supports the beneficial effects of rosuvastatin on venous thrombosis in mice with hyperlipidemia, due to its non-lipid lowering effects.

A low-dose atorvastatin and losartan combination directly improves aortic ring relaxation and diminishes ischaemic-reperfusion injury in isolated rat hearts

Background

The cardiovascular pleiotropic effects of statins and angiotensin receptor blockers (ARBs) could be of interest for innovative preventive approaches. We aimed to investigate whether low-dose atorvastatin and losartan, separately not possessing protective cardiovascular pleiotropic effects, express them when combined.

Material/Methods

Forty-five adult male Wistar rats were anaesthetized and their thoracic aortas and hearts were isolated. Relaxation of aortic rings, coronary flow rate and the extent of myocardial ischaemic-reperfusion injury were measured. Different concentrations (0.01, 0.1, 1.0 μM) of atorvastatin and losartan added to a perfusion medium were first tested. The separate drugs, which were ineffective, were then combined at the same concentrations and the concentration was tested in the same model.

Results

Low concentrations of atorvastatin or losartan (0.1 and 1 μM, respectively) produced no effects in isolated aorta. However, surprisingly, when these drug concentrations were combined, a significantly improved endothelium-dependent relaxation of the thoracic aorta was observed. Similarly, when combining individually ineffective concentrations of atorvastatin or losartan (0.01 and 0.1 μM, respectively), significantly increased coronary flow and a decreased extent of myocardial injury were observed. By using a nitric oxide-synthase inhibitor, we demonstrated that the vasodilatory effects obtained were nitric oxide-dependent. The degree of effectiveness by the combination was comparable to that obtained by 10-fold (atorvastatin) or 100-fold (losartan) higher concentrations of the separate drugs.

Conclusions

Our results revealed that remarkable additive/synergistic effects exist between low-doses of a statin (atorvastatin) and an ARB (losartan), resulting in important cardiovascular protection. This new concept could be valuable in cardiovascular prevention.

Effects of HMG-CoA reductase inhibitor on experimental autoimmune myocarditis

PURPOSE

Myocarditis is an acute inflammatory disease of the heart and is often a precursor of dilated cardiomyopathy. Experimental autoimmune myocarditis (EAM) has been used as a model for human myocarditis. The purpose of this study was to investigate the therapeutic role of 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitor, rosuvastatin, on the development of EAM.

METHODS

Experimental autoimmune myocarditis was induced in BALB/c mice by immunization with murine cardiac α-myosin heavy chain (MyHc-α(614-629) [Ac-SLKLMATLFSTYASAD-OH]). High-dose (10 mg/kg/day) or low-dose (1 mg/kg/day) rosuvastatin or vehicle was administered orally by gastric gavage to mice with EAM from day 0 to day 21 after immunization. On day 21 after immunization, echocardiography was carried out and the severity of myocarditis was detected by histopathological evaluation. Levels of serum tumor necrosis factor (TNF)-α and interleukin (IL)-6 were measured by ELISA. Histopathology was performed using haematoxylin and eosin. With apoptosis examined by Tunel, the expression of active caspase-3 in myocardium was investigated by immunohistochemistry.

RESULTS

Rosuvastatin attenuated the histopathological severity of myocarditis. Cardiac function was improved in the two rosuvastatin-treated groups compared to the non-treated EAM group (LVFS: high-dose rosuvastatin group [group H], 0.38 ± 0.10%; low-dose rosuvastatin group [group L], 0.34 ± 0.06%; non-treated EAM group [group N], 0.29 ± 0.07%. LVEF: group H, 0.80 ± 0.09%; group L, 0.71 ± 0.07%; group N, 0.68 ± 0.07%). Furthermore, treatment with rosuvastatin decreased the expression levels of TNF-α (group H, 65.19 ± 7.06 pg/ml; group L, 108.20 ± 5.28 pg/ml; group N, 239.34 ± 11.65 pg/ml) and IL-6 (group H, 14.33 ± 2.15 pg/ml; group L, 19.67 ± 3.04 pg/ml; group N, 40.39 ± 7.17 pg/ml). The rates of expression of active Caspase-3 and myocardial apoptosis were positively correlated with the scores for myocardial pathology.

CONCLUSIONS

These results demonstrate that administration of rosuvastatin can ameliorate EAM progression, inhibit apoptosis of cardiomyocytes, and preserve cardiac output, and they also suggest rosuvastatin may be a promising novel therapeutic strategy for the clinical treatment of myocarditis.

Generation of polyclonal antibody with high avidity to rosuvastatin and its use in development of highly sensitive ELISA for determination of rosuvastatin in plasma

In this study, a polyclonal antibody with high avidity and specificity to the potent hypocholesterolaemic agent rosuvastatin (ROS) has been prepared and used in the development of highly sensitive enzyme-linked immunosorbent assay (ELISA) for determination of ROS in plasma. ROS was coupled to keyhole limpt hemocyanin (KLH) and bovine serum albumin (BSA) using carbodiimide reagent. ROS-KLH conjugate was used for immunization of female 8-weeks old New Zealand white rabbits. The immune response of the rabbits was monitored by direct ELISA using ROS-BSA immobilized onto microwell plates as a solid phase. The rabbit that showed the highest antibody titer and avidity to ROS was scarified and its sera were collected. The IgG fraction was isolated and purified by avidity chromatography on protein A column. The purified antibody showed high avidity to ROS; IC₅₀ = 0.4 ng/ml. The specificity of the antibody for ROS was evaluated by indirect ELISA using various competitors from the ROS-structural analogues and the therapeutic agents used with ROS in a combination therapy. The proposed ELISA involved a competitive binding reaction between ROS, in plasma sample, and the immobilized ROS-BSA for the binding sites on a limited amount of the anti-ROS antibody. The bound anti-ROS antibody was quantified with horseradish peroxidase-labeled second anti-rabbit IgG antibody (HRP-IgG) and 3,3',5,5'-tetramethylbenzidine (TMB) as a substrate for the peroxidase enzyme. The concentration of ROS in the sample was quantified by its ability to inhibit the binding of the anti-ROS antibody to the immobilized ROS-BSA and subsequently the color intensity in the assay wells. The assay enabled the determination of ROS in plasma at concentrations as low as 40 pg/ml.

The effects of atorvastatin and rosuvastatin on oxidative stress in diabetic patients

AIM

Diabetes is associated with abnormalities in lipid profile and increased oxidative stress. Statins are preferred agents in diabetic patients due to their antioxidant and LDL-C lowering effects. This study is designed to compare the effects of atorvastatin and rosuvastatin on low density lipoprotein cholesterol (LDL-C), lipid hydroperoxide (LOOH), total oxidant status (TOS) and total antioxidant capacity (TAC) in diabetic patients with hyperlipidemia.

MATERIALS AND METHODS

Sixty two patients who have type 2 diabetes mellitus with serum LDL levels more than 100mg/dL were randomly assigned to receive atorvastatin 20mg (n=31) or rosuvastatin 10mg (n=31). Blood tests were performed at the beginning of the study and after three months.

RESULTS

There were no statistically significant differences in the pre- and after treatment levels of the LDL-C between groups. TAC values were increased in both groups and statistically significant in the former group (p=0.007). There was no difference between the change percentages ((after treatment TAC-pretreatment TAC)/pretreatment level) of TAC between two treatment groups. The effects of two drugs on the other oxidative parameters were not significantly different.

CONCLUSION

Both atorvastatin and rosuvastatin may be helpful in reducing increased oxidative stress in diabetic patients with hyperlipidemia.

Monoclonal antibodies targeting IL-1 beta reduce biomarkers of atherosclerosis in vitro and inhibit atherosclerotic plaque formation in Apolipoprotein E-deficient mice

OBJECTIVE

Atherosclerosis is a condition that is increasingly contributing to worldwide mortality through complications such as stroke and myocardial infarction. IL-1β plays multiple direct, local roles in the formation and stability of the atheroma by eliciting the production of additional cytokines and proteolytic enzymes from macrophages, endothelial cells (EC) and smooth muscle cells (SMC). We therefore tested whether an anti-IL-1β antibody, XOMA 052, might inhibit the secretion of pro-atherogenic cytokines from macrophages in vitro and affect a positive outcome in the Apolipoprotein E-deficient mouse (ApoE(-/-)) model of atherosclerosis in vivo.

METHODS AND RESULTS

In an in vitro co-culture model, XOMA 052 inhibited macrophage-induced secretion of key atherogenic cytokines from EC and SMC, including IL-6, IL-8, MCP-1 and TNFα. The release of degradative enzymes, such as the matrix metalloproteinases MMP-3 and MMP-9, was also decreased by XOMA 052. In addition, XOMA 052 inhibited the secretion of IL-7 from EC and IL-4 from SMC, cytokines not previously reported to be driven by IL-1β in this context. In vivo, XMA052 MG1K, a chimeric murine version of XOMA 052, inhibited the formation of atherosclerotic lesions in the ApoE(-/-) model at all three doses tested. This effect was comparable to that reported for complete genetic ablation of IL-1β or IL-1R1 on an ApoE(-/-) background and was associated with decreases in plasma non-HDL/HDL cholesterol ratio and plaque lipid content and macrophage infiltration.

CONCLUSIONS

These results demonstrate for the first time that an antibody targeting IL-1β can inhibit the progression of atherosclerosis in vivo, highlighting the importance of this key cytokine in cardiovascular disease.

Atherosclerosis in chronic kidney disease: the role of macrophages

Patients with chronic kidney disease (CKD) are at increased risk of atherosclerotic cardiovascular disease and loss of renal parenchyma accelerates atherosclerosis in animal models. Macrophages are central to atherogenesis because they regulate cholesterol traffic and inflammation in the arterial wall. CKD influences macrophage behavior at multiple levels, rendering them proatherogenic. Even at normal creatinine levels, macrophages from uninephrectomized Apoe(-/-) mice are enriched in cholesterol owing to downregulation of cholesterol transporter ATP-binding cassette subfamily A member 1 levels and activation of nuclear factor κB, which leads to impaired cholesterol efflux. Interestingly, treatment with an angiotensin-II-receptor blocker (ARB) improves these effects. Moreover, atherosclerotic aortas from Apoe(-/-) mice transplanted into renal-ablated normocholesterolemic recipients show plaque progression and increased macrophage content instead of the substantial regression seen in recipient mice with intact kidneys. ARBs reduce atherosclerosis development in mice with partial renal ablation. These results, combined with the clinical benefits of angiotensin-converting-enzyme (ACE) inhibitors and ARBs in patients with CKD, suggest an important role for the angiotensin system in the enhanced susceptibility to atherosclerosis seen across the spectrum of CKD. The role of macrophages could explain why these therapies may be effective in end-stage renal disease, one of the few conditions in which statins show no clinical benefit.

Lipid-lowering agents and new onset diabetes mellitus

Statin treatment (and possibly niacin when given alone or in combination with statins) appears to be associated with a slightly increased risk of new onset diabetes mellitus (NODM). However, statin induced cardiovascular disease (CVD) risk reduction is greater in patients with DM than in non-diabetic patients in several survival studies. Thus, statin treatment outweighs any potential increase in CVD risk related to NODM and in high-risk Caucasian patients present clinical practice should not change. However, the risk/benefit ratio of treatment might not be as favourable in subjects with propensity to develop DM such as the elderly and in subjects of Asian ethnicity. Colesevelam was shown to improve both glycaemic control and lipid profile in inadequately controlled T2DM and might reduce the risk for NODM. There are no data on the incidence of NODM in fibrate-treated non-diabetic patients. Prospective studies are needed to clarify these issues.

Diagnostic potential of plasma carboxymethyllysine and carboxyethyllysine in multiple sclerosis

BACKGROUND

This study compared the level of advanced glycation end products (AGEs), N-(Carboxymethyl)lysine (CML) and N-(Carboxyethyl)lysine (CEL), in patients with multiple sclerosis (MS) and healthy controls (HCs), correlating these markers with clinical indicators of MS disease severity.

METHODS

CML and CEL plasma levels were analyzed in 99 MS patients and 43 HCs by tandem mass spectrometry (LC/MS/MS). Patients were stratified based on drug modifying therapies (DMTs) including interferon beta, glatiramer acetate and natalizumab.

RESULTS

The level of plasma CEL, but not CML, was significantly higher in DMT-naïve MS patients when compared to HCs (P < 0.001). Among MS patients, 91% had higher than mean plasma CEL observed in HCs. DMTs reduced CML and CEL plasma levels by approximately 13% and 40% respectively. CML and CEL plasma levels correlated with the rate of MS clinical relapse.

CONCLUSION

Our results suggest that AGEs in general and CEL in particular could be useful biomarkers in MS clinical practice. Longitudinal studies are warranted to determine any causal relationship between changes in plasma level of AGEs and MS disease pathology. These studies will pave the way for use of AGE inhibitors and AGE-breaking agents as new therapeutic modalities in MS.

Plasma pentosidine: a potential biomarker in the management of multiple sclerosis

Background: The chronic inflammation associated with multiple sclerosis (MS) may lead to the upregulation of pentosidine.

Objectives: This cross-sectional study compares plasma pentosidine levels among healthy controls (HCs) and patients with MS at different disease stages. The study also determines pentosidine's usefulness as a biomarker of MS disease activity and/or severity via its correlation with a number of indicators of MS disease.

Methods: Pentosidine levels were analyzed in 98 MS patients and 43 HCs using reverse-phase high-pressure liquid chromatography with fluorescence detection.

Results: Plasma pentosidine levels were significantly higher in MS patients when compared with HCs ( p = 0.02). Patients on disease-modifying therapies (DMTs) had lower plasma pentosidine levels when compared with DMT-naïve patients ( p =  0.01). Pentosidine plasma levels correlated with indicators of MS disease severity, including Extended Disability Status Scale ( p = 0.03), MS Severity Scale ( p = 0.01), and MS Functional Composite ( p = 0.03). No correlation between pentosidine levels and age, rate of clinical relapse, and disease duration was observed.

Conclusions: Our results suggest that pentosidine could be a novel, inflammatory biomarker in MS clinical practice. Longitudinal studies are warranted to determine any causal relationship between changes in plasma pentosidine levels and MS disease pathology. These studies may pave the way for use of advanced glycation end product (AGE) inhibitors and AGE-breaking agents as new therapeutic modalities in MS.

Angiotensin II type 1 receptor-dependent oxidative stress mediates endothelial dysfunction in type 2 diabetic mice

The mechanisms underlying the effect of the renin-angiotensin-aldosterone system (RAAS) inhibition on endothelial dysfunction in type 2 diabetes are incompletely understood. This study explored a causal relationship between RAAS activation and oxidative stress involved in diabetes-associated endothelial dysfunction. Daily oral administration of valsartan or enalapril at 10 mg/kg/day to db/db mice for 6 weeks reversed the blunted acetylcholine-induced endothelium-dependent dilatations, suppressed the upregulated expression of angiotensin II type 1 receptor (AT(1)R) and NAD(P)H oxidase subunits (p22(phox) and p47(phox)), and reduced reactive oxygen species (ROS) production. Acute exposure to AT(1)R blocker losartan restored the impaired endothelium-dependent dilatations in aortas of db/db mice and also in renal arteries of diabetic patients (fasting plasma glucose level > or =7.0 mmol/l). Similar observations were also made with apocynin, diphenyliodonium, or tempol treatment in db/db mouse aortas. DHE fluorescence revealed an overproduction of ROS in db/db aortas which was sensitive to inhibition by losartan or ROS scavengers. Losartan also prevented the impairment of endothelium-dependent dilatations under hyperglycemic conditions that were accompanied by high ROS production. The present study has identified an initiative role of AT(1)R activation in mediating endothelial dysfunction of arteries from db/db mice and diabetic patients.

Liver x receptor signaling pathways and atherosclerosis

First discovered as orphan receptors, liver X receptors (LXRs) were subsequently identified as the nuclear receptor target of the cholesterol metabolites, oxysterols. There are 2 LXR receptors encoded by distinct genes: LXRalpha is most highly expressed in the liver, adipose, kidney, adrenal tissues, and macrophages and LXRbeta is ubiquitously expressed. Despite differential tissue distribution, these isoforms have 78% homology in their ligand-binding domain and appear to respond to the same endogenous ligands. Work over the past 10 years has shown that the LXR pathway regulates lipid metabolism and inflammation via both the induction and repression of target genes. Given the importance of cholesterol regulation and inflammation in the development of cardiovascular disease, it is not surprising that activation of the LXR pathway attenuates various mechanisms underlying atherosclerotic plaque development. In this brief review, we will discuss the impact of the LXR pathway on both cholesterol metabolism and atherosclerosis.

Macrovascular complications of diabetes in atherosclerosisprone mice

The well-established relationship between diabetes and cardiovascular complications, combined with the rapidly increasing prevalence of diabetes, has created a pressing need for better understanding of the mechanisms of diabetic atherosclerosis. Multiple metabolic and diabetes-specific factors have been associated with accelerated atherosclerosis, including dyslipidemia, oxidative stress, inflammation, vascular cell dysfunction and coagulopathy. This discussion highlights selected studies in which researchers have employed mouse models of diabetic atherosclerosis in an attempt to examine these mechanisms and test potential therapeutic and preventative measures.