Rosuvastatin treatment protects against nitrate-induced oxidative stress in eNOS knockout mice: implication of the NAD(P)H oxidase pathway

NanoUPLC-QTOF-MS/MS Determination of Major Rosuvastatin Degradation Products Generated by Gamma Radiation in Aqueous Solution

Rosuvastatin, a member of the statin family of drugs, is used to regulate high cholesterol levels in the human body. Moreover, rosuvastatin and other statins demonstrate a protective role against free radical-induced oxidative stress. Our research aimed to investigate the end-products of free radical-induced degradation of rosuvastatin. To induce the radical degradation, an aqueous solution of rosuvastatin was irradiated using different doses of gamma radiation (50-1000 Gy) under oxidative conditions. Rosuvastatin and related degradation products were separated on nanoC18 column under gradient elution, and identification was carried out on hyphenated nanoUPLC and nanoESI-QTOF mass spectrometer system. Elemental composition analysis using highly accurate mass measurements together with isotope fitting algorithm identified nine major degradation products. This is the first study of gamma radiation-induced degradation of rosuvastatin, where chemical structures, MS/MS fragmentation pathways and formation mechanisms of the resulting degradation products are detailly described. The presented results contribute to the understanding of the degradation pathway of rosuvastatin and possibly other statins under gamma radiation conditions.

The Effect of Rosuvastatin on Plasma/Serum Levels of High-Sensitivity C-Reactive Protein, Interleukin-6, and D-Dimer in People Living with Human Immunodeficiency Virus: A Systematic Review and Meta-Analysis

Rosuvastatin therapy might have an effect on the inflammatory and coagulation biomarkers. However, the evidence about the effect of rosuvastatin therapy on the high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), and D-dimer levels among people living with human immunodeficiency virus (PLHIV) is still unclear. Therefore, this study investigated the relational effect of rosuvastatin therapy on serum/plasma hsCRP, IL-6 and D-dimer levels in PLHIV. The literature search was done from Embase, PubMed, and Web of Science databases. The review and meta-analysis included studies written in English language up to January 4, 2020. Random effects model was used to evaluate the pooled standard mean difference with 95% confidence interval. A meta-analysis was performed using nine articles with 392 PLHIV. The result revealed that the plasma/serum levels of IL-6 were significantly reduced after the intervention. However, hsCRP and D-dimer levels showed no significant difference (p > .05) between before and after the intervention. The subgroup analysis showed that there was significant association between PLHIV ages <45 years and cohort studies with IL-6 levels. The current CD4⁺ counts ≥350 cells/mm³ correlated with hsCRP as well as IL-6. Similarly, nadir CD4⁺ counts ≥200 cells/mm³ and duration of HIV diagnosis <10 years also showed significant association with IL-6 and D-dimer levels. It was also indicated that participants who were under antiretroviral drug for <7 years were significantly associated with hsCRP levels. This study established that IL-6 levels were significantly reduced after the intervention while hsCRP and D-dimer levels showed no significant difference between before and after the intervention.

Lactobacilli modulated AMPK activity and prevented telomere shortening in ageing rats

This study aimed to evaluate the anti-ageing effects of different strains of lactobacilli putative probiotics on an ageing rat model as induced by D-galactose and a high fat diet. Male Sprague-Dawley rats were fed with high fat diet (54% kcal fat) and injected with D-galactose daily for 12 weeks to induce ageing. The effects of putative probiotic strains on age-related impairment such as telomere length, plasma lipid peroxidation, hepatic 5'adenosine monophosphate-activated protein kinase (AMPK) expression, as well as endurance performance were evaluated. Administration of statin, Lactobacillus plantarum DR7 (LP-DR7), Lactobacillus fermentum DR9 (LF-DR9), and Lactobacillus reuteri 8513d (LR-8513d) significantly reduced the shortening of telomere and increased the expression of AMPK subunit-α1 (P<0.05). Plasma lipid peroxidation was lower (P<0.05) in groups administered with statin and LF-DR9 as compared to the control. AMPK subunit-α2 was elevated in rats administered with LP-DR7 as compared to the control (P<0.05). Using an in vivo ageing rat model, the current study has illustrated the potentials of lactobacilli putative probiotics in alleviation of age-related impairment in a strain-dependent manner.

Pharmacological modulation of dietary lipid-induced cerebral capillary dysfunction: Considerations for reducing risk for Alzheimer's disease

An increasing body of evidence suggests that cerebrovascular dysfunction and microvessel disease precede the evolution of hallmark pathological features that characterise Alzheimer's disease (AD), consistent with a causal association for onset or progression. Recent studies, principally in genetically unmanipulated animal models, suggest that chronic ingestion of diets enriched in saturated fats and cholesterol may compromise blood-brain barrier (BBB) integrity resulting in inappropriate blood-to-brain extravasation of plasma proteins, including lipid macromolecules that may be enriched in amyloid-β (Aβ). Brain parenchymal retention of blood proteins and lipoprotein bound Aβ is associated with heightened neurovascular inflammation, altered redox homeostasis and nitric oxide (NO) metabolism. Therefore, it is a reasonable proposition that lipid-lowering agents may positively modulate BBB integrity and by extension attenuate risk or progression of AD. In addition to their robust lipid lowering properties, reported beneficial effects of lipid-lowering agents were attributed to their pleiotropic properties via modulation of inflammation, oxidative stress, NO and Aβ metabolism. The review is a contemporary consideration of a complex body of literature intended to synthesise focussed consideration of mechanisms central to regulation of BBB function and integrity. Emphasis is given to dietary fat driven significant epidemiological evidence consistent with heightened risk amongst populations consuming greater amounts of saturated fats and cholesterol. In addition, potential neurovascular benefits associated with the use of hypolipidemic statins, probucol and fenofibrate are also presented in the context of lipid-lowering and pleiotropic properties.

Migraine Triggers and Oxidative Stress: A Narrative Review and Synthesis

BACKGROUND

Blau theorized that migraine triggers are exposures that in higher amounts would damage the brain. The recent discovery that the TRPA1 ion channel transduces oxidative stress and triggers neurogenic inflammation suggests that oxidative stress may be the common denominator underlying migraine triggers.

OBJECTIVE

The aim of this review is to present and discuss the available literature on the capacity of common migraine triggers to generate oxidative stress in the brain.

METHODS

A Medline search was conducted crossing the terms "oxidative stress" and "brain" with "alcohol," "dehydration," "water deprivation," "monosodium glutamate," "aspartame," "tyramine," "phenylethylamine," "dietary nitrates," "nitrosamines," "noise," "weather," "air pollutants," "hypoglycemia," "hypoxia," "infection," "estrogen," "circadian," "sleep deprivation," "information processing," "psychosocial stress," or "nitroglycerin and tolerance." "Flavonoids" was crossed with "prooxidant." The reference lists of the resulting articles were examined for further relevant studies. The focus was on empirical studies, in vitro and of animals, of individual triggers, indicating whether and/or by what mechanism they can generate oxidative stress.

RESULTS

In all cases except pericranial pain, common migraine triggers are capable of generating oxidative stress. Depending on the trigger, mechanisms include a high rate of energy production by the mitochondria, toxicity or altered membrane properties of the mitochondria, calcium overload and excitotoxicity, neuroinflammation and activation of microglia, and activation of neuronal nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. For some triggers, oxidants also arise as a byproduct of monoamine oxidase or cytochrome P450 processing, or from uncoupling of nitric oxide synthase.

CONCLUSIONS

Oxidative stress is a plausible unifying principle behind the types of migraine triggers encountered in clinical practice. The possible implications for prevention and for understanding the nature of the migraine attack are discussed.

Supplementation of nitric oxide attenuates AβPP and BACE1 protein in cerebral microcirculation of eNOS-deficient mice

Recently, we demonstrated in endothelial nitric oxide synthase deficient (eNOS-/-) mice that loss of endothelial NO led to increased protein levels of amyloid-β protein precursor (AβPP), β-site AβPP cleaving enzyme 1 (BACE1), and amyloid-β (Aβ) peptide. Therefore, our aim was to determine if NO supplementation in vivo would attenuate AβPP and BACE1 protein levels. cGMP levels were significantly increased while AβPP and BACE1 protein levels were statistically lower in cerebral microvessels from nitroglycerin-treated eNOS-/- mice as compared to vehicle-treated mice. Our findings support the concept that preservation of NO/cGMP signaling is an important modulator of expression and processing of AβPP.

Role of lipotoxicity in endothelial dysfunction

Vascular endothelial dysfunction is determined by both genetic and environmental factors that cause decreased bioavailability of the vasodilator nitric oxide. This is a hallmark of atherosclerosis, hypertension, and coronary heart disease, which are major complications of metabolic disorders, including diabetes and obesity. Several therapeutic interventions, including changes in lifestyle as well as pharmacologic treatments, are useful for improving endothelial dysfunction in the face of lipotoxicity. This review discusses the current understanding of molecular and physiologic mechanisms underlying lipotoxicity-mediated endothelial dysfunction as well as relevant therapeutic approaches to ameliorate dyslipidemia and consequent endothelial dysfunction that have the potential to improve cardiovascular and metabolic outcomes.

Nitroglycerin drives endothelial nitric oxide synthase activation via the phosphatidylinositol 3-kinase/protein kinase B pathway

Nitroglycerin (GTN) has been clinically used to treat angina pectoris and acute heart episodes for over 100 years. The effects of GTN have long been recognized and active research has contributed to the unraveling of numerous metabolic routes capable of converting GTN to the potent vasoactive messenger nitric oxide. Recently, the mechanism by which minute doses of GTN elicit robust pharmacological responses was revisited and eNOS activation was implicated as an important route mediating vasodilation induced by low GTN doses (1-50nM). Here, we demonstrate that at such concentrations the pharmacologic effects of nitroglycerin are largely dependent on the phosphatidylinositol 3-kinase, Akt/PKB, and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) signal transduction axis. Furthermore, we demonstrate that nitroglycerin-dependent accumulation of 3,4,5-InsP(3), probably because of inhibition of PTEN, is important for eNOS activation, conferring a mechanistic basis for GTN pharmacological action at pharmacologically relevant doses.

Rapid, direct effects of statin treatment on arterial redox state and nitric oxide bioavailability in human atherosclerosis via tetrahydrobiopterin-mediated endothelial nitric oxide synthase coupling

BACKGROUND

Treatment with statins improves clinical outcome, but the exact mechanisms of pleiotropic statin effects on vascular function in human atherosclerosis remain unclear. We examined the direct effects of atorvastatin on tetrahydrobiopterin-mediated endothelial nitric oxide (NO) synthase coupling in patients with coronary artery disease.

METHODS AND RESULTS

We first examined the association of statin treatment with vascular NO bioavailability and arterial superoxide (O(2)(·-)) in 492 patients undergoing coronary artery bypass graft surgery. Then, 42 statin-naïve patients undergoing elective coronary artery bypass graft surgery were randomized to atorvastatin 40 mg/d or placebo for 3 days before surgery to examine the impact of atorvastatin on endothelial function and O(2)(·-) generation in internal mammary arteries. Finally, segments of internal mammary arteries from 26 patients were used in ex vivo experiments to evaluate the statin-dependent mechanisms regulating the vascular redox state. Statin treatment was associated with improved vascular NO bioavailability and reduced O(2)(·-) generation in internal mammary arteries. Oral atorvastatin increased vascular tetrahydrobiopterin bioavailability and reduced basal and N-nitro-l-arginine methyl ester-inhibitable O(2)(·-) in internal mammary arteries independently of low-density lipoprotein lowering. In ex vivo experiments, atorvastatin rapidly improved vascular tetrahydrobiopterin bioavailability by upregulating GTP-cyclohydrolase I gene expression and activity, resulting in improved endothelial NO synthase coupling and reduced vascular O(2)(·-). These effects were reversed by mevalonate, indicating a direct effect of vascular hydroxymethylglutaryl-coenzyme A reductase inhibition.

CONCLUSIONS

This study demonstrates for the first time in humans the direct effects of statin treatment on the vascular wall, supporting the notion that this effect is independent of low-density lipoprotein lowering. Atorvastatin directly improves vascular NO bioavailability and reduces vascular O(2)(·-) through tetrahydrobiopterin-mediated endothelial NO synthase coupling. These findings provide new insights into the mechanisms mediating the beneficial vascular effects of statins in humans.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01013103.

Coadministration of atorvastatin prevents nitroglycerin-induced endothelial dysfunction and nitrate tolerance in healthy humans

OBJECTIVES

We aimed to assess whether concurrent administration of atorvastatin would modify the development of tolerance and endothelial dysfunction associated with sustained nitroglycerin (GTN) therapy in humans.

BACKGROUND

Animal studies have demonstrated that administration of 3-hydroxy-3 methylglutaryl coenzyme A reductase inhibitors can protect against GTN-induced endothelial dysfunction and tolerance, likely through an antioxidant mechanism.

METHODS

Thirty-six healthy male volunteers were randomized to receive continuous transdermal GTN (0.6 mg/h) and placebo, atorvastatin (80 mg/day) alone, or continuous transdermal GTN (0.6 mg/h) with concurrent atorvastatin (80 mg/day), all for 7 days. On the second visit, forearm blood flow was measured with venous-occlusion strain gauge plethysmography in response to incremental infusions of acetylcholine (7.5, 15, and 30 μg/min). Acetylcholine infusions were coinfused first with saline, and repeated during the coinfusion of vitamin C (24 mg/min). Blood pressure responses to sublingual GTN (400 μg) were assessed on both visits.

RESULTS

Acetylcholine responses in the GTN plus placebo group were significantly attenuated versus those in the GTN plus atorvastatin and atorvastatin groups (p < 0.01). Coinfusion of vitamin C completely restored acetylcholine responses in the GTN plus placebo group (p < 0.01 vs. saline coinfusion), but caused no change in either the atorvastatin or the GTN plus atorvastatin groups. Blood pressure responses to sublingual GTN did not significantly change between visits in subjects receiving GTN plus atorvastatin and atorvastatin alone, but were significantly blunted in the GTN plus placebo group (p < 0.05).

CONCLUSIONS

The present findings demonstrate, for the first time in humans, that atorvastatin prevents both GTN-induced endothelial dysfunction and nitrate tolerance, likely by counteracting the GTN-induced increase in oxidative stress.

Rosuvastatin reduces microglia in the brain of wild type and ApoE knockout mice on a high cholesterol diet; implications for prevention of stroke and AD

We have previously shown that a high cholesterol (HC) diet results in increases in microglia load and levels of the pro-inflammatory cytokine interleukin-6 (IL-6) in the brains of wild type (WT) and apolipoprotein E knockout (ApoE-/-) mice. In the present investigation, we analyzed whether treatment with rosuvastatin, an inhibitor of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, would prevent the increases in inflammatory microglia and IL-6 levels in the brain and plasma of WT and ApoE-/- mice. We report that a HC diet resulted in an increased microglia load in the brains of WT and ApoE-/- mice, in support of our previous study. Treatment with rosuvastatin significantly decreased the microglia load in the brains of WT and ApoE-/- mice on a HC diet. Rosuvastatin treatment resulted in lowered plasma IL-6 levels in WT mice on a HC diet. However, in the present study the number of IL-6 positive cells in the brain was not significantly affected by a HC diet. A recent clinical study has shown that rosuvastatin reduces risk of ischemic stroke in patients with high plasma levels of the inflammatory marker C-reactive protein by 50%. The results from our study show that rosuvastatin reduces inflammatory cells in the brain. This finding is essential for furthering the prevention and treatment of neurodegenerative diseases such as Alzheimer's disease (AD) and stroke.

Preoperative atorvastatin treatment in CABG patients rapidly improves vein graft redox state by inhibition of Rac1 and NADPH-oxidase activity

BACKGROUND

Statins improve clinical outcome of patients with atherosclerosis, but their perioperative role in patients undergoing coronary artery bypass grafting (CABG) is unclear. We hypothesized that short-term treatment with atorvastatin before CABG would improve the redox state in saphenous vein grafts (SVGs), independently of low-density lipoprotein cholesterol (LDL)-lowering.

METHODS AND RESULTS

In a randomized, double-blind controlled trial, 42 statin-naïve patients undergoing elective CABG received atorvastatin 40 mg/d or placebo for 3 days before surgery. Circulating inflammatory markers and malondialdehyde (MDA) were measured before and after treatment. SVG segments were used to determine vascular superoxide (O(2)(*-)) and Rac1 activation. For ex vivo studies, SVG segments from 24 patients were incubated for 6 hours with atorvastatin 0, 5, or 50 μmol/L. Oral atorvastatin reduced vascular basal and NADPH-stimulated O(2)(*-) in SVGs (P<0.05 for all versus placebo) and reduced plasma MDA (P<0.05), independently of LDL-lowering and of changes in inflammatory markers. In SVGs exposed to atorvastatin ex vivo, without exposure to LDL, basal and NADPH-stimulated O(2)(·-) were significantly reduced (P<0.01 for both concentrations versus 0 μmol/L) in association with a striking reduction in Rac1 activation and 1 membrane-bound Rac1 and p67(phox) subunit. The antioxidant effects of atorvastatin were reversed by mevalonate, implying a dependence on vascular HMG-CoA reductase inhibition.

CONCLUSIONS

Short-term treatment with atorvastatin 40 mg/d before CABG improves redox state in SVGs, by inhibiting vascular Rac1-mediated activation of NADPH-oxidase. These novel findings suggest that statin therapy should be maintained or initiated in patients undergoing CABG, independently of LDL levels. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01013103.

Statins: multiple neuroprotective mechanisms in neurodegenerative diseases

Statins have been widely used for the treatment of a variety of conditions beyond their original role in lowering cholesterol. Since statins have relatively few side effects, they have been recognized as useful medicine to ameliorate neurodegenerative disorders. Current studies on the applications of statins have demonstrated their neuroprotective and clinical significance among neurodegenerative diseases like cerebral ischemic stroke, vascular dementia, Alzheimer's disease, and Parkinson's disease, though the neuroprotective mechanisms are not completely understood. This review will discuss recent development in the use of statins in slowing down the progression of these neurodegenerative diseases. It will summarize the potential mechanisms for statin-mediated neuroprotective effects in neurodegenerative diseases. In detail, this review discuss the roles of statins in lowering cholesterol, reducing reactive oxygen species, impairing β-amyloid production and serum apolipoprotein E levels, enhancing the levels of endothelial nitric oxide synthase and cerebral blood flow, and modulating cognitive related receptors and matrix metalloproteases. Finally, different alterations of various receptors in brain regions following statin treatment and their correlations with cognitive dysfunction in Parkinson's disease will also be reviewed, as well as the potential for therapy in ameliorating the progression of Parkinson's disease. This article is part of a Special Issue entitled "Interaction between repair, disease, & inflammation."

Suppressing NADPH oxidase-dependent oxidative stress in the vasculature with nitric oxide donors

1. Reactive oxygen species produced in the vasculature, including superoxide anion, contribute to the pathogenesis of cardiovascular disease states, such as atherosclerosis. A critical source of superoxide is vascular NADPH oxidase and upregulation of this enzyme brings about the oxidative stress underlying atherosclerosis. Excessive superoxide in arteries directly inactivates endothelium-derived nitric oxide (NO), compromising its vasoprotective effects. 2. Given that a reduction in NO bioavailability is key in the pathophysiology of atherosclerosis, replacement of NO by exogenously administered NO donors may restore the deficit in NO during disease. Although the organic nitrate family of NO donors is often the first choice for the acute management of symptoms of atherosclerosis and angina pectoris, most of the compounds in this class are unsuitable for long-term therapy because they cause oxidative stress by activation and upregulation of vascular NADPH oxidase and induce tolerance to subsequent nitrate treatment and endogenous NO. These problems of nitrates have not only limited their therapeutic exploitation, but have also stifled interest in newer-generation NO donors. 3. Recent evidence indicates that, in stark contrast with the organic nitrates, the newer-age diazeniumdiolate NONOate class of NO donors suppress vascular NADPH oxidase-dependent superoxide production and are less likely to induce tolerance, making them more suitable for suppression of oxidative stress in atherosclerosis. 4. Here, it is hypothesized that NONOates provide a novel means of suppressing NADPH oxidase-dependent oxidative stress to restore vascular NO levels to prevent, and even reverse, atherosclerosis.

The role of lipoic acid in prevention of nitroglycerin tolerance

Besides other organic nitrates, nitroglycerin (glyceryl trinitrate; GTN) has been used to treat acute heart failure particularly due to ischemic heart disease. However, one of serious clinical problems of the GTN therapy, particularly a long-standing medication, is hemodynamic tolerance to GTN, manifested by the decreased therapeutic efficacy of the drug. The most recent studies have suggested that mitochondrial lipoate/dihydrolipoate system-dependent aldehyde dehydrogenase-2 plays a key role in nitric oxide release from GTN. The aldehyde dehydrogenase-2 performs three enzymatic activities of dehydrogenase, esterase and reductase. The reductase activity is responsible for bioactivation of organic nitrates, such as GTN yielding nitrite and dinitrate (1,2-GDN/1,3-GDN, approximately 8:1). In view of a large contribution of dihydrolipoic acid to stabilization and regeneration of thiol groups, necessary for the reductase activity of aldehyde dehydrogenase-2, we conducted studies aimed to determine whether lipoic acid administration to rats is able to prevent GTN tolerance. The studies were conducted on 4 groups of animals: control saline-treated, model GTN-tolerant, GTN + lipoic acid-treated, lipoic acid alone-administered groups. On the 9th day of experiment animals were given i.v. therapeutic dose of GTN. We measured in all animals systolic and diastolic blood pressure before injection of therapeutic dose of GTN into the cadual vein and during 20 min thereafter. Levels of nitric oxide and reactive oxygen species and activities of glutathione peroxidase and superoxide dismutase were assayed in the aorta, plasma and heart of all animals. In addition, levels of malondialdehyde, and non-protein thiols, and activities of glutathione S-transferase and gamma-glutamyl transpeptidase were evaluated in the heart and plasma. The obtained results indicate that treatment of rats with a combination of lipoic acid and GTN can efficiently counteract GTN tolerance.

An overview of the extra-lipid effects of rosuvastatin

Statins, in addition to their beneficial lipid modulation effects, exert a variety of several so-called "pleiotropic" actions that may result in clinical benefits. Rosuvastatin, the last agent of the class to be introduced, has proved remarkably potent in reducing low-density lipoprotein cholesterol levels. At present, no large-scale primary or secondary prevention clinical trials document either its long-term safety or its effectiveness in preventing cardiovascular events. A substantial number of experimental and clinical studies have indicate favorable effects of rosuvastatin on endothelial function, oxidized low-density lipoprotein, inflammation, plaque stability, vascular remodeling, hemostasis, cardiac muscle, and components of the nervous system. Available data regarding the effects of rosuvastatin on renal function and urine protein excretion do not seem to raise any safety concerns. Whether the established "pleiotropy" and/or lipid-lowering efficacy of rosuvastatin may translate into reduced morbidity and mortality remains to be shown in ongoing clinical outcome trials.

Protective effects of atorvastatin on chronic allograft nephropathy in rats

OBJECTIVE

Chronic allograft nephropathy (CAN) is the leading cause of late kidney allograft loss. Recent studies have suggested that atorvastatin (ATO) may interact with the acute inflammatory process in the renal interstitium and suppress the proliferation of mesangial cells. We hypothesized that ATO could also inhibit the chronic inflammatory process and prevent the progression of CAN.

MATERIALS AND METHODS

Fisher (F344) kidneys were orthotopically transplanted into Lewis rat recipients. Lewis-to-Lewis rat kidney transplantation was served as the syngeneic control (Syn group). Allograft recipients were randomized and treated with cyclosporine A alone (Allo group) or in combination with ATO (15 or 30 mg/kg/d intrgastric, respectively, the low dose treatment group/high dose treatment group [LT/HT] groups). Renal function and the urine protein excretion were analyzed. Animals were sacrificed 20 weeks posttransplantation for histological and immunohistochemical studies, as well as analysis of mRNA levels of cytokines and chemokines.

RESULTS

Renal function progressively deteriorated and substantial proteinuria developed in the Allo group compared with the Syn group. ATO-treated rats had significantly higher creatinine clearance rate and less amount of proteinuria. Histological examination revealed obvious features of CAN in the Allo group, whereas LT/HT groups demonstrated minimal glomerulosclerosis, interstitial fibrosis, intimal thickening, and tubular atrophy. The numbers of infiltrating mononuclear cells (ED1+, CD8+, and CD68+) decreased markedly, and the intragraft expression of transforming growth factor beta1 (TGF-beta1) and collagen III were also significantly attenuated in the LT/HT groups, as compared with the Allo group. The mRNA levels of proinflammatory cytokines (interleukin-2, interferon-gamma, interleukin-10), chemokines (RANTES, MCP-1), and profibrotic genes (TGF-beta1, collagen III) were significantly down-regulated in ATO-treated rats.

CONCLUSION

Atorvastatin showed excellent favorable effects on blocking renal inflammation and fibrosis, and thus, efficiently inhibited the development and progression of CAN, which might improve the long-term survival rate of renal allografts.

Differential effects of organic nitrates on endothelial progenitor cells are determined by oxidative stress

OBJECTIVE

Reduced levels and impaired function of endothelial progenitor cells (EPCs) foster development and progression of atherosclerotic lesions. Endothelial nitric oxide synthase (eNOS)-derived NO regulates EPC mobilization and function. Organic nitrates release NO, and therefore may favorably affect EPC biology.

METHODS AND RESULTS

We compared the effects of 2 different nitrates on circulating EPC numbers and function. Treatment of rats with pentaerythritol-trinitrate (PETriN) or isosorbide dinitrate (ISDN) increased circulating EPC levels. EPC from ISDN- but not PETriN-treated animals displayed impaired migratory capacity and increased reactive oxygen species formation in EPCs. In vitro treatment with ISDN reduced migration and incorporation of human EPCs into vascular structures on matrigel, whereas PETriN improved EPC function. ISDN, but not PETriN, increased NADPH oxidase-mediated oxidative stress in cultured human EPCs. Addition of polyethylene-glycolated superoxide dismutase or diphenyliodonium normalized both ISDN-induced superoxide anion production and impaired migratory capacity of EPCs.

CONCLUSIONS

Long-acting nitrates increase levels of circulating EPCs, but differ in their effects on EPC function dependent on the induction of intracellular oxidative stress. Organic nitrates that improve EPC function may confer long-term cardiovascular protection based on their beneficial effects on EPC biology.