Pitavastatin, an HMG-CoA reductase inhibitor, exerts eNOS-independent protective actions against angiotensin II induced cardiovascular remodeling and renal insufficiency

Transforming growth factor-β and bone morphogenetic protein signaling pathways in pathological cardiac hypertrophy

Pathological cardiac hypertrophy (referred to as cardiac hypertrophy) is a maladaptive response of the heart to a variety of pathological stimuli, and cardiac hypertrophy is an independent risk factor for heart failure and sudden death. Currently, the treatments for cardiac hypertrophy are limited to improving symptoms and have little effect. Elucidation of the developmental process of cardiac hypertrophy at the molecular level and the identification of new targets for the treatment of cardiac hypertrophy are crucial. In this review, we summarize the research on multiple active substances related to the pathogenesis of cardiac hypertrophy and the signaling pathways involved and focus on the role of transforming growth factor-β (TGF-β) and bone morphogenetic protein (BMP) signaling in the development of cardiac hypertrophy and the identification of potential targets for molecular intervention. We aim to identify important signaling molecules with clinical value and hope to help promote the precise treatment of cardiac hypertrophy and thus improve patient outcomes.

Anti-fibrotic effects of statin drugs: a review of evidence and mechanisms

Fibrosis is a pathological repair process common among organs, that responds to damage by replacement of tissue with non-functional connective tissue. Despite the widespread prevalence of tissue fibrosis, manifesting in numerous disease states across myriad organs, therapeutic modalities to prevent or alleviate fibrosis are severely lacking in quantity and efficacy. Alongside development of new drugs, repurposing of existing drugs may be a complementary strategy to elect anti-fibrotic compounds for pharmacologic treatment of tissue fibrosis. Drug repurposing can provide key advantages to de novo drug discovery, harnessing the benefits of previously elucidated mechanisms of action and already existing pharmacokinetic profiles. One class of drugs a wealth of clinical data and extensively studied safety profiles is the statins, a class of antilipidemic drugs widely prescribed for hypercholesterolemia. In addition to these widely utilized lipid-lowering effects, increasing data from cellular, pre-clinical mammalian, and clinical human studies have also demonstrated that statins are able to alleviate tissue fibrosis originating from a variety of pathological insults via lesser-studied, pleiotropic effects of these drugs. Here we review literature demonstrating evidence for direct effects of statins antagonistic to fibrosis, as well as much of the available mechanistic data underlying these effects. A more complete understanding of the anti-fibrotic effects of statins may enable a clearer picture of their anti-fibrotic potential for various clinical indications. Additionally, more lucid comprehension of the mechanisms by which statins exert anti-fibrotic effects may aid in development of novel therapeutic agents that target similar pathways but with greater specificity or efficacy.

Astragaloside IV attenuates high glucose-induced human keratinocytes injury via TGF-β/Smad signaling pathway

OBJECTIVES

In this study, we have investigated the effect of Astragaloside IV on keratinocytes' proliferation, migration, oxidative stress, apoptosis, inflammation, and relevant signaling pathway, using human keratinocytes exposed to high glucose.

BACKGROUND

Astragaloside IV is one of the main active ingredients of Astragalus membranaceus (Fisch.) Bunge. Previous studies have found that Astragaloside IV exerts positive effects in various disease models and promotes wound healing.

METHODS

Cell proliferation and migration of keratinocytes, oxidative stress indicators, cell apoptosis rate, inflammatory factors, and key proteins in the TGF-β/Smad signaling pathway were evaluated by molecular biology/biochemical techniques, fluorescence microscope, and flow cytometry.

RESULTS

High glucose inhibited the cell proliferation and migration of keratinocytes, upregulated the levels of MDA, ROS, IL-6, IL-8, and Smad7, and decreased the levels of SOD, IL-10, TGF-β1, p-Smad2, and p-Smad3. Astragaloside IV attenuated the dysfunction of keratinocytes, oxidative stress, cell apoptosis, and inflammation, but activated TGF-β/Smad signaling pathway. Meanwhile, the addition of SB431542 (the inhibitor of TGF-β/Smad signaling pathway) eliminated the impact of Astragaloside IV on high glucose-induced keratinocytes.

CONCLUSIONS

These results strongly suggest that Astragaloside IV may be a potential drug candidate for accelerating diabetic wound healing, by protecting keratinocytes against damages induced by high glucose and TGF-β/Smad pathway is involved in this process at the cellular level.

Effect of lipid-lowering medications in patients with coronary artery bypass grafting surgery outcomes

BACKGROUND

Increased life expectancy and improved medical technology allow increasing numbers of elderly patients to undergo cardiac surgery. Elderly patients may be at greater risk of postoperative morbidity and mortality. Complications can lead to worsened quality of life, shortened life expectancy and higher healthcare costs. Reducing perioperative complications, especially severe adverse events, is key to improving outcomes in patients undergoing cardiac surgery. The objective of this study is to determine whether perioperative lipid-lowering medication use is associated with a reduced risk of complications and mortality after coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB).

METHODS

After IRB approval, we reviewed charts of 9,518 patients who underwent cardiac surgery with CPB at three medical centers between July 2001 and June 2015. The relationship between perioperative lipid-lowering treatment and postoperative outcome was investigated. 3,988 patients who underwent CABG met inclusion criteria and were analyzed. Patients were divided into lipid-lowering or non-lipid-lowering treatment groups.

RESULTS

A total of 3,988 patients were included in the final analysis. Compared to the patients without lipid-lowering medications, the patients with lipid-lowering medications had lower postoperative neurologic complications and overall mortality (P < 0.05). Propensity weighted risk-adjustment showed that lipid-lowering medication reduced in-hospital total complications (odds ratio (OR) = 0.856; 95% CI 0.781-0.938; P < 0.001); all neurologic complications (OR = 0.572; 95% CI 0.441-0.739; P < 0.001) including stroke (OR = 0.481; 95% CI 0.349-0.654; P < 0.001); in-hospital mortality (OR = 0.616; 95% CI 0.432-0.869; P = 0.006; P < 0.001); and overall mortality (OR = 0.723; 95% CI 0.634-0.824; P < 0.001). In addition, the results indicated postoperative lipid-lowering medication use was associated with improved long-term survival in this patient population.

CONCLUSIONS

Perioperative lipid-lowering medication use was associated with significantly reduced postoperative adverse events and improved overall outcome in elderly patients undergoing CABG surgery with CPB.

Atorvastatin does not ameliorate nephrogenic diabetes insipidus induced by lithium or potassium depletion in mice

Acquired forms of nephrogenic diabetes insipidus (NDI) include lithium (Li)-induced and hypokalemia-induced NDI. Both forms are associated with AQP2 downregulation and collecting duct (CD) cellular remodeling. Statins are cholesterol-lowering drugs appearing to increase AQP2 membrane-translocation and improve urine concentration in other NDI models. We have investigated if statins are able to prevent or rescue the Li-induced changes in mice and in a mouse cortical CD cell line (mCCDc1l ). Biotinylation assays showed that acute (1hr) atorvastatin, simvastatin, or fluvastatin increased AQP2 membrane accumulation in mCCDc1l cells showing that the cell line responds to acute statin treatment. To see whether chronic statin treatment abolish the Li effects, mCCDc1l cells were treated with 48 h Li, combined Li/atorvastatin or combined Li/simvastatin. Li reduced AQP2, but combined Li/atorvastatin or Li/simvastatin did not prevent AQP2 downregulation. In mice, chronic (21 days) Li increased urine output and reduced urine osmolality, but combined Li/atorvastatin did not prevent these effects. In inner medulla (IM), Li reduced total AQP2 and increased pS261-AQP2. Combined Li/atorvastatin did not abolish these changes. Atorvastatin did not prevent a Li-induced increase in intercalated cells and proliferation in IM. In mice with already established NDI, atorvastatin had no effect on the Li-induced changes either. Mice subjected to 14 days of potassium-deficient diet developed polyuria and AQP2 downregulation in IM. Co-treatment with atorvastatin did not prevent this. In conclusion, atorvastatin does not appear to be able to prevent or rescue Li-NDI or to prevent hypokalemic-induced NDI.

β 3-Adrenergic Receptor Agonist Prevents Diastolic Dysfunction in an Angiotensin II-Induced Cardiomyopathy Mouse Model

β3-Adrenergic receptor expression is enhanced in the failing heart, but its functional effects are unclear. We tested the hypothesis that a β3-agonist improves left ventricular (LV) performance in heart failure. We examined the chronic effects of a β3-agonist in the angiotensin II (Ang II)-induced cardiomyopathy mouse model. C57BL/6J mice were treated with Ang II alone or Ang II + BRL 37344 (β3-agonist, BRL) for 4 weeks. Systolic blood pressure in conscious mice was significantly elevated in Ang II and Ang II + BRL mice compared with control mice. Heart rate was not different among the three groups. Systolic performance parameters that were measured by echocardiography and an LV catheter were similar among the groups. LV end-diastolic pressure and end-diastolic pressure-volume relationships were higher in Ang II mice compared with control mice. However, the increase in these parameters was prevented in Ang II + BRL mice, which suggested improvement in myocardial stiffness by BRL. Pathologic analysis showed that LV hypertrophy was induced in Ang II mice and failed to be prevented by BRL. However, increased collagen I/III synthesis, cardiac fibrosis, and lung congestion observed in Ang II mice were inhibited by BRL treatment. The cardioprotective benefits of BRL were associated with downregulation of transforming growth factor-β1 expression and phosphorylated-Smad2/3. Chronic infusion of a β3-agonist has a beneficial effect on LV diastolic function independent of blood pressure in the Ang II-induced cardiomyopathy mouse model. SIGNIFICANCE STATEMENT: Chronic infusion of a β3-adrenergic receptor agonist attenuates cardiac fibrosis and improves diastolic dysfunction independently of blood pressure in an angiotensin II-induced hypertensive mouse model. This drug might be an effective treatment of heart failure with preserved ejection fraction.

The role of Smad signaling cascades in cardiac fibrosis

Most myocardial pathologic conditions are associated with cardiac fibrosis, the expansion of the cardiac interstitium through deposition of extracellular matrix (ECM) proteins. Although replacement fibrosis plays a reparative role after myocardial infarction, excessive, unrestrained or dysregulated myocardial ECM deposition is associated with ventricular dysfunction, dysrhythmias and adverse prognosis in patients with heart failure. The members of the Transforming Growth Factor (TGF)-β superfamily are critical regulators of cardiac repair, remodeling and fibrosis. TGF-βs are released and activated in injured tissues, bind to their receptors and transduce signals in part through activation of cascades involving a family of intracellular effectors the receptor-activated Smads (R-Smads). This review manuscript summarizes our knowledge on the role of Smad signaling cascades in cardiac fibrosis. Smad3, the best-characterized member of the family plays a critical role in activation of a myofibroblast phenotype, stimulation of ECM synthesis, integrin expression and secretion of proteases and anti-proteases. In vivo, fibroblast Smad3 signaling is critically involved in scar organization and exerts matrix-preserving actions. Although Smad2 also regulates fibroblast function in vitro, its in vivo role in rodent models of cardiac fibrosis seems more limited. Very limited information is available on the potential involvement of the Smad1/5/8 cascade in cardiac fibrosis. Dissection of the cellular actions of Smads in cardiac fibrosis, and identification of patient subsets with overactive or dysregulated myocardial Smad-dependent fibrogenic responses are critical for design of successful therapeutic strategies in patients with fibrosis-associated heart failure.

Anti-arrhythmic properties of non-antiarrhythmic medications

Traditional anti-arrhythmic drugs are classified by the Vaughan-Williams classification scheme based on their mechanisms of action, which includes effects on receptors and/or ion channels. Some known anti-arrhythmic drugs do not perfectly fit into this classification scheme. Other medications/molecules with established non-anti-arrhythmic indications have shown anti-arrhythmic properties worth exploring. In this narrative review, we discuss the molecular mechanisms and evidence base for the anti-arrhythmic properties of traditional non-antiarrhythmic drugs such as inhibitors of the renin angiotensin system (RAS), statins and polyunsaturated fatty acids (PUFAs). In summary, RAS antagonists, statins and PUFAs are 'upstream target modulators' that appear to have anti-arrhythmic roles. RAS blockers prevent the downstream arrhythmogenic effects of angiotensin II - the main effector peptide of RAS - and the angiotensin type 1 receptor. Statins have pleiotropic effects including anti-inflammatory, immunomodulatory, modulation of autonomic nervous system, anti-proliferative and anti-oxidant actions which appear to underlie their anti-arrhythmic properties. PUFAs have the ability to alter ion channel function and prevent excessive accumulation of calcium ions in cardiac myocytes, which might explain their benefits in certain arrhythmic conditions. Clearly, whilst a number of anti-arrhythmic drugs exist, there is still a need for randomised trials to establish whether additional agents, including those already in clinical use, have significant anti-arrhythmic effects.

Fluvastatin prevents the development of arthritis in env-pX rats via up-regulation of Rho GTPase-activating protein 12

The pleiotropic effects of statins, including an antiarthritic potential, have been noted. This study aimed to determine the efficacy of statins on rheumatoid arthritis (RA) and clarify how statins affect its pathogenesis. Fluvastatin (500 μg/kg/day) or vehicle was given per os to env-pX rats, which carry the human T-cell leukemia virus type I env-pX gene and spontaneously develop destructive arthritis mimicking RA, for 30 days. Blood sampling and ultrasonography (US) of the ankle joints were conducted on days 0, 10, 20, and 30. On day 30, all rats were euthanized, and the ankle joints were subjected to histological analysis. To clarify how fluvastatin affects the pathogenesis of RA, comprehensive serum exosomal microRNA (miRNA) analysis was performed. Gene expression in the primary culture of synovial fibroblasts derived from arthritic rat and human and non-arthritic rat periarticular tissues was determined quantitatively by real-time reverse transcription-polymerase chain reaction (RT-PCR). As a result, the development of arthritis in env-pX rats was significantly suppressed by fluvastatin, which was evident from the viewpoints of serology, US imaging, and histology. Comprehensive serum exosomal miRNA analysis suggested that the expression of Rho GTPase-activating protein 12 (Arhgap12) was decreased in arthritic env-pX rats but increased with the administration of fluvastatin. Corresponding results were obtained by quantitative RT- PCR using primary culture of synovial fibroblasts. The collective findings suggest that fluvastatin prevents the development of arthritis in env-pX rats via the up-regulation of ARHGAP12. This study suggests that ARHGAP12 can be a possible therapeutic target of RA.

Cardiomyocyte calcineurin is required for the onset and progression of cardiac hypertrophy and fibrosis in adult mice

Previous studies have demonstrated that activation of calcineurin induces pathological cardiac hypertrophy (CH). In these studies, loss-of-function was mostly achieved by systemic administration of the calcineurin inhibitor cyclosporin A. The lack of conditional knockout models for calcineurin function has impeded progress toward defining the role of this protein during the onset and the development of CH in adults. Here, we exploited a mouse model of CH based on the infusion of a hypertensive dose of angiotensin II (AngII) to model the role of calcineurin in CH in adulthood. AngII-induced CH in adult mice was reduced by treatment with cyclosporin A, without affecting the associated increase in blood pressure, and also by induction of calcineurin deletion in adult mouse cardiomyocytes, indicating that cardiomyocyte calcineurin is required for AngII-induced CH. Surprisingly, cardiac-specific deletion of calcineurin, but not treatment of mice with cyclosporin A, significantly reduced AngII-induced cardiac fibrosis and apoptosis. Analysis of profibrotic genes revealed that AngII-induced expression of Tgfβ family members and Lox was not inhibited by cyclosporin A but was markedly reduced by cardiac-specific calcineurin deletion. These results show that AngII induces a direct, calcineurin-dependent prohypertrophic effect in cardiomyocytes, as well as a systemic hypertensive effect that is independent of calcineurin activity.

Association of Decreased Docosahexaenoic Acid Level After Statin Therapy and Low Eicosapentaenoic Acid Level with In-Stent Restenosis in Patients with Acute Coronary Syndrome

Aim: It is speculated that statin therapy modulates the synthesis of polyunsaturated fatty acids (PUFA), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). However, the data available on the effects of statin therapy on the serum levels of PUFA and the subsequent impact on in-stent restenosis (ISR) in patients with acute coronary syndrome (ACS) are limited.

Methods: A total of 120 ACS patients who received emergent coronary stent implantation, follow-up coronary angiography to evaluate ISR, and new statin therapy were enrolled. We measured the serum levels of the PUFA and lipids at the onset of ACS and at the follow-up coronary angiography.

Results: The follow-up coronary angiography revealed 38 ISR cases. New statin therapy significantly reduced the serum levels of DHA and low-density lipoprotein cholesterol (LDL-C), while it did not affect EPA level. Single regression analysis revealed that a decreased serum level of LDL-C was associated with decreased DHA level. The multiple logistic regression analysis revealed that the decreased DHA level after statin therapy and low serum level of EPA on admission were determinants of prevalence of ISR.

Conclusion: Statin therapy decreased the serum level of DHA with a parallel reduction in LDL-C level in patients with ACS. Decreased DHA level after statin therapy and low EPA level on admission are risk factors for ISR, indicating that in patients with ACS, decreased serum levels of DHA may be a residual target for the prevention of ISR.

Epicardial Adipose Tissue May Mediate Deleterious Effects of Obesity and Inflammation on the Myocardium

Epicardial adipose tissue has unique properties that distinguish it from other depots of visceral fat. Rather than having distinct boundaries, the epicardium shares an unobstructed microcirculation with the underlying myocardium, and in healthy conditions, produces cytokines that nourish the heart. However, in chronic inflammatory disorders (especially those leading to heart failure with preserved ejection fraction), the epicardium becomes a site of deranged adipogenesis, leading to the secretion of proinflammatory adipokines that can cause atrial and ventricular fibrosis. Accordingly, in patients at risk of heart failure with preserved ejection fraction, drugs that promote the accumulation or inflammation of epicardial adipocytes may lead to heart failure, whereas treatments that ameliorate the proinflammatory characteristics of epicardial fat may reduce the risk of heart failure. These observations suggest that epicardial adipose tissue is a transducer of the adverse effects of systemic inflammation and metabolic disorders on the heart, and thus, represents an important target for therapeutic interventions.

Shenfu Injection attenuates rat myocardial hypertrophy by up-regulating miR-19a-3p expression

Shenfu Injection (SFI) is a classical Chinese medicine used to treat heart failure. Our previous study demonstrated that miRNAs underwent changes in rats with myocardial hypertrophy induced by abdominal aortic constriction. Interestingly, there was a significant change in miR-19a-3p, whose target gene is known to be associated with MEF2 signaling. However, whether and how SFI regulates miR-19a-3p in the treatment of myocardial hypertrophy has not been investigated. The purpose of the present study was to investigate the regulatory effect of SFI on miR-19a-3p in MEF2 signaling in the rat hypertrophic myocardium. We found that the miR-19a-3p expression level was significantly decreased in the hypertrophic myocardium, and MEF2A was the target gene of miR-19a-3p. The protein expressions of MEF2A, β-MHC, BNP and TRPC1 were significantly increased in hypertrophic cardiomyocytes. MiR-19a-3p was up-regulated after SFI treatment, and the protein expressions of these genes were significantly decreased. In addition, miR-19a-3p over-expression in hypertrophic cardiomyocytes could decrease MEF2A mRNA and protein expressions, and anti-miR-19a-3p showed the opposite result. Our study provided substantial evidence that miR-19a-3p played a functional role in MEF2 signaling in myocardial hypertrophy. SFI attenuated cardiomyocyte hypertrophy probably through up-regulating or maintaining the miR-19a-3p levels and regulating the MEF2 signaling pathway.

Adjunctive therapy with statins reduces residual albuminuria/proteinuria and provides further renoprotection by downregulating the angiotensin II-AT1 pathway in hypertensive nephropathy

OBJECTIVES

Blockade of the renin-angiotensin II (Ang II) system by AT1 blockers (ARBs) and angiotensin-converting enzyme inhibitors retards the progression of chronic kidney disease (CKD) by reducing albuminuria/proteinuria. However, many patients with CKD suffer from residual albuminuria/proteinuria, which is an independent risk factor for CKD progression. The aim of the current study is to investigate the effect of pitavastatin, one of the adjunctive agents to ARBs, on the reduction of albuminuria/proteinuria and further renoprotection mediated by telmisartan in spontaneously hypertensive rats.

METHODS AND RESULTS

Forty-two-week-old spontaneously hypertensive rats were grouped randomly and received 8 weeks of treatments with vehicle, telmisartan, pitavastatin or a combination of telmisartan and pitavastatin. Both albuminuria and proteinuria were inhibited significantly in the telmisartan-treated group, but an obviously residual albuminuria was maintained. The combination treatment with telmisartan and pitavastatin displayed a more effective decrease in albuminuria and proteinuria, even to the normal level. Enhanced nephroprotection was also observed in this combination group, which was independent of the cholesterol-lowering effects. Further mechanistic studies revealed that the combination therapy greatly attenuated the expression of intrarenal Ang II and AT1, thereby decreasing the activation of TGF-β-Smad and NF-κB and inhibiting fibrosis and inflammation.

CONCLUSION

Adjunctive therapy with pitavastatin dramatically reduced residual albuminuria/proteinuria and enhanced nephroprotection, likely by downregulating the expression of intrarenal Ang II and AT1. It could be concluded that statins might be a promising adjunctive therapeutic agent to conventional ARB treatment in hypertensive renal damage.

Rosuvastatin improves myocardial hypertrophy after hemodynamic pressure overload via regulating the crosstalk of Nrf2/ARE and TGF-β/ smads pathways in rat heart

Left ventricular hypertrophy is more commonly associated with hemodynamic overload imposed by hypertension or volume overload. Transforming growth factor β (TGF-β) is involved in the cardiac hypertrophy and fibrosis of the left ventricle. The fact that TGF-β1 and the nuclear factor erythroid 2-related factor 2 (Nrf2) both become up-regulated upon persistent vessel overload suggests that these two factors may virtually impact on their signaling pathways. In this research, 40 rats were divided into sham group, model group, rosuvastatin low and high dose group. Rat models were established by incomplete constriction of abdominal aorta. After five weeks treatment, blood pressure, heart mass index (HMI), hemodynamic parameters and the average diameter of myocardium cell and collagen volume fraction (CVF) improved significantly in rosuvastatin groups, compared with the model group. Both rosuvastatin groups, increased in expression of Smad7, Nrf2, NAD (P) H dehydrogenase [quinone] 1 (Nqo1) and heme oxygenase 1(Ho1),and decreased in expression of TGF-βl、Smad3 compared with the model group. Results from co-immunoprecipitation and GST pull down showed that Nrf2 interacts with Smad7. Our results revealed the crosstalk between TGF-β1/Smads and Nrf2/ antioxidant response elements (ARE) pathways in myocardial remodeling through the interaction between Smad7 and Nrf2. Rosuvastatin can improve cardiac function and hypertrophy by regulating the crosstalk of the two signaling pathways.

n-3 Polyunsaturated Fatty Acids: Promising Nutrients for Preventing Cardiovascular Disease

The adoption of the Western-style diet, with decreased fish intake and lack of exercise, has increased the prevalence of cardiovascular disease (CVD) in Japan. Statin treatment has been established to reduce the risk of cardiovascular events; however, 60%–70% of these events occur despite its use. Thus, the residual risk for CVD should be identified and resolved to reduce further cardiovascular events. The serum levels of n-3 polyunsaturated fatty acids (PUFAs), including eicosapentaenoic acid and docosahexaenoic acid, are reportedly associated with an increased incidence of cardiovascular events and mortality, whereas the addition of n-3 PUFA treatment to the statin treatment decreases cardiovascular events. Similar to statins, n-3 PUFAs have pleiotropic effects in addition to lipid-modifying effects. Pre-clinical and clinical studies have shown that n-3 PUFAs prevent cardiovascular events by ameliorating endothelial function and attenuating lipid accumulation, vascular inflammation, and macrophage recruitment, thereby causing coronary plaque development and rupture. Taken together, n-3 PUFAs are comprehensively able to attenuate the atherogenic response. Therefore, n-3 PUFA intake is recommended to prevent cardiovascular events, particularly in patients with multiple cardiovascular risk factors.

Endothelial Nitric Oxide Synthase-Independent Pleiotropic Effects of Pitavastatin Against Atherogenesis and Limb Ischemia in Mice

Aim: Statins have a protective impact against cardiovascular diseases through not only lipid-lowering effects but also pleiotropic effects, including activation of the endothelial nitric oxide synthase (eNOS) system. We aimed to clarify the protective effects of a statin against atherogenesis and ischemia in eNOS^−/− mice.

Methods: Study 1. eNOS^−/−Apolipoprotein E (ApoE)^−/− mice were treated with a vehicle or pitavastatin (0.3 mg/kg/day) for 4 weeks. Study 2. eNOS^−/− mice were also treated with a vehicle or the same dose of pitavastatin for 2 weeks prior to hind-limb ischemia.

Results: In Study 1, pitavastatin attenuated plaque formation and medial fibrosis of the aortic root with decreased macrophage infiltration in eNOS^−/−ApoE^−/− mice. PCR array analysis showed reductions in aortic gene expression of proatherogenic factors, including Ccl2 and Ccr2 in pitavastatin-treated double mutant mice. In addition, pitavastatin activated not only atherogenic p38MAPK and JNK but also anti-atherogenic ERK1/2 and ERK5 in the aorta of the double mutant mice. In Study 2, pitavastatin prolonged hind-limb survival after the surgery with increased BCL2-to-BAX protein ratio and inactivated JNK. Enhanced expression of anti-apoptotic genes, including Vegf, Api5, Atf5, Prdx2, and Dad1, was observed in the ischemic limb of pitavastatin-treated eNOS^−/− mice. Furthermore, pitavastatin activated both aortic and skeletal muscle AMPK in the eNOS-deficient vascular injury models.

Conclusion: Pitavastatin exerts eNOS-independent protective effects against atherogenesis and hindlimb ischemia in mice, which may occur via modifications on key molecules such as AMPK and diverse molecules.

Pleiotropic Effects of Myocardial MMP-9 Inhibition to Prevent Ventricular Arrhythmia

Observational studies have established a strong association between matrix metalloproteinase-9 (MMP-9) and ventricular arrhythmia. However, whether MMP-9 has a causal link to ventricular arrhythmia, as well as the underlying mechanism, remains unclear. Here, we investigated the mechanistic involvement of myocardial MMP-9 in the pathophysiology of ventricular arrhythmia. Increased levels of myocardial MMP-9 are linked to ventricular arrhythmia attacks after angiotensin II (Ang II) treatment. MMP-9-deficient mice were protected from ventricular arrhythmia. Increased expressions of protein kinase A (PKA) and ryanodine receptor phosphorylation at serine 2808 (pS2808) were correlated with inducible ventricular arrhythmia. MMP-9 deficiency consistently prevented PKA and pS2808 increases after Ang II treatment and reduced ventricular arrhythmia. Calcium dynamics were examined via confocal imaging in isolated murine cardiomyocytes. MMP-9 inhibition prevents calcium leakage from the sarcoplasmic reticulum and reduces arrhythmia-like irregular calcium transients via protein kinase A and ryanodine receptor phosphorylation. Human induced pluripotent stem cell-derived cardiomyocytes similarly show that MMP-9 inhibition prevents abnormal calcium leakage. Myocardial MMP-9 inhibition prevents ventricular arrhythmia through pleiotropic effects, including the modulation of calcium homeostasis and reduced calcium leakage.

The expression of Smad signaling pathway in myocardium and potential therapeutic effects

Myocardial infarction (MI) is a life-threatening disease. The expression of Smad proteins in the ischemic myocardium changes significantly following myocardial infarction, suggesting a close relationship between Smad proteins and heart remodeling. Moreover, it is known that the expression of Smads is regulated by transforming growth factor-β (TGF-β) and bone morphogenetic proteins (BMP). Based on these findings, regulating the expression of Smad proteins by targeting TGF-β and BMP in the ischemic myocardium may be considered to be a possible therapeutic strategy for the treatment of myocardial infarction.

Pleiotropic effects of statins: new therapeutic targets in drug design

The HMG Co-enzyme inhibitors and new lipid-modifying agents expand their new therapeutic target options in the field of medical profession. Statins have been described as the most effective class of drugs to reduce serum cholesterol levels. Since the discovery of the first statin nearly 30 years ago, these drugs have become the main therapeutic approach to lower cholesterol levels. The present scientific research demonstrates numerous non-lipid modifiable effects of statins termed as pleiotropic effects of statins, which could be beneficial for the treatment of various devastating disorders. The most important positive effects of statins are anti-inflammatory, anti-proliferative, antioxidant, immunomodulatory, neuroprotective, anti-diabetes, and antithrombotic, improving endothelial dysfunction and attenuating vascular remodeling besides many others which are discussed under the scope of this review. In particular, inhibition of Rho and its downstream target, Rho-associated coiled-coil-containing protein kinase (ROCK), and their agonistic action on peroxisome proliferator-activated receptors (PPARs) can be viewed as the principle mechanisms underlying the pleiotropic effects of statins. With gradually increasing knowledge of new therapeutic targets of statins, their use has also been advocated in chronic inflammatory disorders for example rheumatoid arthritis (RA) and in systemic lupus erythematosus (SLE). In the scope of review, we highlight statins and their pleiotropic effects with reference to their harmful and beneficial effects as a novel approach for their use in the treatment of devastating disorders. Graphical abstract Pleiotropic effect of statins.

SmgGDS as a Crucial Mediator of the Inhibitory Effects of Statins on Cardiac Hypertrophy and Fibrosis: Novel Mechanism of the Pleiotropic Effects of Statins

The detailed molecular mechanisms of the pleiotropic effects of statins remain to be fully elucidated. Here, we hypothesized that cardioprotective effects of statins are mediated by small GTP-binding protein GDP dissociation stimulator (SmgGDS). SmgGDS(+/-) and wild-type (WT) mice were treated with continuous infusion of angiotensin II (Ang II) for 2 weeks with and without oral treatment with atorvastatin or pravastatin. At 2 weeks, the extents of Ang II-induced cardiac hypertrophy and fibrosis were comparable between the 2 genotypes. However, statins significantly attenuated cardiomyocyte hypertrophy and fibrosis in WT mice, but not in SmgGDS(+/-) mice. In SmgGDS(+/-) cardiac fibroblasts (CFs), Rac1 expression, extracellular signal-regulated kinases 1/2 activity, Rho-kinase activity, and inflammatory cytokines secretion in response to Ang II were significantly increased when compared with WT CFs. Atorvastatin significantly reduced Rac1 expression and oxidative stress in WT CFs, but not in SmgGDS(+/-) CFs. Furthermore, Bio-plex analysis revealed significant upregulations of inflammatory cytokines/chemokines and growth factors in SmgGDS(+/-) CFs when compared with WT CFs. Importantly, conditioned medium from SmgGDS(+/-) CFs increased B-type natriuretic peptide expression in rat cardiomyocytes to a greater extent than that from WT CFs. Furthermore, atorvastatin significantly increased SmgGDS secretion from mouse CFs. Finally, treatment with recombinant SmgGDS significantly reduced Rac1 expression in SmgGDS(+/-) CFs. These results indicate that both intracellular and extracellular SmgGDS play crucial roles in the inhibitory effects of statins on cardiac hypertrophy and fibrosis, partly through inhibition of Rac1, Rho kinase, and extracellular signal-regulated kinase 1/2 pathways, demonstrating the novel mechanism of the pleiotropic effects of statins.

AVE 3085, a novel endothelial nitric oxide synthase enhancer, attenuates cardiac remodeling in mice through the Smad signaling pathway

AVE 3085 is a novel endothelial nitric oxide synthase enhancer. Although AVE 3085 treatment has been shown to be effective in spontaneously restoring endothelial function in hypertensive rats, little is known about the effects and mechanisms of AVE 3085 with respect to cardiac remodeling. The present study was designed to examine the effects of AVE 3085 on cardiac remodeling and the mechanisms underlying the effects of this compound. Mice were subjected to aortic banding to induce cardiac remodeling and were then administered AVE 3085 (10 mg kg day(-1), orally) for 4 weeks. At the end of the treatment, the aortic banding-treated mice exhibited significant elevations in cardiac remodeling, characterized by an increase in left ventricular weight relative to body weight, an increase in the area of collagen deposition, an increase in the mean myocyte diameter, and increases in the gene expressions of the hypertrophic markers atrial natriuretic peptide (ANP) and β-MHC. These indexes were significantly decreased in the AVE 3085-treated mice. Furthermore, AVE 3085 treatment reduced the expression and activation of the Smad signaling pathway in the aortic banding-treated mice. Our data showed that AVE 3085 attenuated cardiac remodeling, and this effect was possibly mediated through the inhibition of Smad signaling.

Biomarkers and pharmaceutical strategies in steroid-induced osteonecrosis of the femoral head: A literature review

The underlying pathology of steroid-induced osteonecrosis of the femoral head (ONFH) is unclear but is known to be multifactorial. It is therefore difficult to find a single predictive biomarker for this disease, and multiple biomarkers are likely to contribute to ONFH progression. Investigation of protein–protein interactions is vital in order to elucidate fully the pathogenesis of this disease, and provide new treatment strategies. This review article discusses the known biomarkers and current treatment strategies for ONFH.

Most appropriate animal models to study the efficacy of statins: a systematic review

BACKGROUND

In animal models and clinical trials, statins are reported as effective in reducing cholesterol levels and lowering the risk of cardiovascular diseases. We have aggregated the findings in animal models - mice, rats and rabbits - using the technique of systematic review and meta-analysis to highlight differences in the efficacy of statins.

MATERIALS AND METHODS

We searched Medline and Embase. After examining all eligible articles, we extracted results about total cholesterol and other blood parameters, blood pressure, myocardial infarction and survival. Weighted and standard mean difference random effects meta-analysis was used to measure overall efficacy in prespecified species, strains and subgroups.

RESULTS

We included in systematic review 161 animal studies and we analysed 120 studies, accounting for 2432 animals. Statins lowered the total cholesterol across all species, although with large differences in the effect size: -30% in rabbits, -20% in mice and -10% in rats. The reduction was larger in animals fed on a high-cholesterol diet. Statins reduced infarct volume but did not consistently reduce the blood pressure or effect the overall survival. Few studies considered strains at high risk of cardiovascular diseases or hard outcomes.

CONCLUSIONS

Although statins showed substantial efficacy in animal models, few preclinical data considered conditions mimicking human pathologies for which the drugs are clinically indicated and utilized. The empirical finding that statins are more effective in lowering cholesterol derived from an external source (i.e. diet) conflicts with statin's supposed primary mechanism of action.

N-Acetylcysteine effects on transforming growth factor-β and tumor necrosis factor-α serum levels as pro-fibrotic and inflammatory biomarkers in patients following ST-segment elevation myocardial infarction

Background and Aims

Ischemia following acute myocardial infarction (AMI) increases the level of pro-fibrotic and inflammatory cytokines, including transforming growth factor (TGF)-β and tumor necrosis factor (TNF)-α. N-acetylcysteine (NAC) has therapeutic benefits in the management of patients with AMI. To the best of our knowledge, this is the first study that has evaluated the effect of NAC on TNF-α and TGF-β levels in patients with AMI.

Methods

Following confirmation of AMI, 88 patients were randomly administered NAC 600 mg (Fluimucil^®, Zambon, Ticino, Switzerland) or placebo orally twice daily for 3 days. For quantification of TGF-β and TNF-α serum levels after 24 and 72 h of NAC or placebo administration, peripheral venous blood (10 mL) samples were collected at these time points.

Results

Comparisons between levels of TGF-β and TNF-α after 24 and 72 h within the NAC or placebo groups revealed that there was not any significant difference except for TGF-β levels in the placebo group, which increased significantly over time (p = 0.042). Significant relationships existed between patients’ ejection fraction (p = 0.005) and TGF-β levels.

Conclusions

Receiving NAC could prevent TGF-β levels from increasing after 72 h as compared with not receiving NAC. As TGF-β had strong correlations with the ejection fraction, its antagonism seems to be important in the prevention of remodeling.

Endothelial dysfunction exacerbates renal interstitial fibrosis through enhancing fibroblast Smad3 linker phosphorylation in the mouse obstructed kidney

Endothelial dysfunction and enhanced transforming growth factor-β (TGF-β)/Smad3 signalling are common features of progressive renal fibrosis. This study investigated a potential link between these mechanisms. In unilateral ureteric obstruction (UUO) we observed an acute (6 hr) down-regulation of nitric oxide synthase 3 (NOS3/eNOS) levels and increased phosphorylation of the linker region of Smad3 at T179 and S208 in Smad3/JNK complexes. These events preceded Smad3 C-terminal domain phosphorylation and the induction of myofibroblast proliferation at 48 hrs. Mice deficient in NOS3 showed enhanced myofibroblast proliferation and collagen accumulation compared to wild type mice in a 7 day UUO model. This was associated with enhanced phosphorylation of Smad3 T179 and S208 by 92% and 88%, respectively, whereas Smad3-C-terminal phosphorylation was not affected. Resolvin D1 (RvD1) can suppress renal fibrosis in the UUO model, and further analysis herein showed that RvD1 protected against endothelial dysfunction and suppressed Smad3/JNK complex formation with a consequent reduction in phosphorylation of Smad3 T179 and S208 by 78% and 65%, respectively, while Smad3 C-terminal phosphorylation was unaltered. In vitro, conditioned media from mouse microvascular endothelial cells (MMEC) treated with a general inhibitor of nitric oxide synthase (L-NAME) augmented the proliferation and collagen production of renal fibroblasts (NRK49F cells) compared to control MMEC media and this was associated with increased phosphorylation of JNK and Smad3 T179 and S208, whereas Smad3-C-terminal domain phosphorylation was unaffected. The addition of RvD1 to L-NAME treated MMEC abrogated these effects of the conditioned media on renal fibroblasts. Finally, Smad3 T179/V and S208/A mutations significantly inhibit TGF-β1 induced up-regulation collagen I promoter. In conclusion, these data suggest that endothelial dysfunction can exacerbate renal interstitial fibrosis through increased fibroblast proliferation and collagen production via enhanced Smad3 linker phosphorylation.

Dehydroepiandrosterone induces ovarian and uterine hyperfibrosis in female rats

STUDY QUESTION

Do dehydroepiandrosterone (DHEA)-treated rats with polycystic ovary syndrome (PCOS) demonstrate a high level of fibrosis in ovarian and uterine tissues?

SUMMARY ANSWER

DHEA induces ovarian and uterine hyperfibrosis in rats, probably involving a transforming growth factor-β (TGF-β)-dependent mechanism.

WHAT IS KNOWN ALREADY

Chronic inflammation is the typical cause of fibrosis and is involved in the pathophysiological process of PCOS. Patients with PCOS are reported to have a higher serum level of TGF-β, a well-characterized key pro-fibrotic factor. Fibrillin-3, a protein capable of interacting with TGF-β, has been reported to be partially responsible for the fetal origin of PCOS.

STUDY DESIGN, SIZE, DURATION

Female Sprague-Dawley rats were treated with a vehicle control or DHEA for 35 days, with subsequent analyses of changes in morphology and gene expression in ovarian and uterine tissues. Rescue groups treated with metformin or simvastatin and their corresponding controls were also analyzed. A total of 80 rats were included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The PCOS model was induced by daily administration of DHEA s.c. to 3-week-old female rats, and the rescue groups were injected daily with either metformin or simvastatin in addition to DHEA. Serum steroid hormone levels were measured by enzyme-linked immunosorbent assay. Samples were stained with hematoxylin and eosin for histological morphology, and Sirius Red and immunohistochemistry for revealing collagens. The expression of fibrosis-related genes was analyzed both at mRNA (real-time RT-PCR) and protein (western blot) levels.

MAIN RESULTS AND THE ROLE OF CHANCE

DHEA-induced rats with PCOS exhibited significantly higher levels of fibrosis (collagen IV) in both ovarian and uterine tissues. In ovarian tissue, the expression of connective tissue growth factor (CTGF) increased following DHEA treatment at both mRNA and protein levels (P < 0.05, P < 0.001 versus controls, respectively). Similar results versus controls were obtained at a protein level for TGF-β (P < 0.01) and mRNA level for fibronectin (P < 0.05) and angiotensin-II (P < 0.05). Likewise, in uterine tissue, the protein levels of both CTGF and TGF-β were higher than controls following DHEA treatment (P < 0.05). Treatment with either metformin or simvastatin attenuated the fibrosis progression induced by DHEA exposure, as evidenced by a reduction of TGF-β, plus CTGF or not, in both ovarian and uterine tissues.

LIMITATIONS, REASONS FOR CAUTION

The particular mechanism involved in the DHEA-induced fibrosis was not fully revealed.

WIDER IMPLICATIONS OF THE FINDINGS

Ovarian and uterine hyperfibrosis may occur in patients with PCOS and result in anovulation or other PCOS-related phenotypes. Anti-fibrotic therapy, for example metformin treatment, may be beneficial for patients with PCOS.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Natural Science Foundation of China (81170541) and the Natural Basic Research Program of China (973 program 2010CB945103). The authors declare no conflicts of interest.

Statins exert the pleiotropic effects through small GTP-binding protein dissociation stimulator upregulation with a resultant Rac1 degradation

OBJECTIVE

The pleiotropic effects of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) independent of cholesterol-lowering effects are thought to be mediated through inhibition of the Rho/Rho-kinase pathway. However, we have previously demonstrated that the pleiotropic effects of regular-dose statins are mediated mainly through inhibition of the Rac1 signaling pathway rather than the Rho/Rho-kinase pathway, although the molecular mechanisms of the selective inhibition of the Rac1 signaling pathway by regular-dose statins remain to be elucidated. In this study, we tested our hypothesis that small GTP-binding protein GDP dissociation stimulator (SmgGDS) plays a crucial role in the molecular mechanisms of the Rac1 signaling pathway inhibition by statins in endothelial cells.

APPROACH AND RESULTS

In cultured human umbilical venous endothelial cells, statins concentration-dependently increased SmgGDS expression and decreased nuclear Rac1. Statins also enhanced SmgGDS expression in mouse aorta. In control mice, the protective effects of statins against angiotensin II-induced medial thickening of coronary arteries and fibrosis were noted, whereas in SmgGDS-deficient mice, the protective effects of statins were absent. When SmgGDS was knocked down by its small interfering RNA in human umbilical venous endothelial cells, statins were no longer able to induce Rac1 degradation or inhibit angiotensin II-induced production of reactive oxygen species. Finally, in normal healthy volunteers, statins significantly increased SmgGDS expression with a significant negative correlation between SmgGDS expression and oxidative stress markers, whereas no correlation was noted with total or low-density lipoprotein-cholesterol.

CONCLUSIONS

These results indicate that statins exert their pleiotropic effects through SmgGDS upregulation with a resultant Rac1 degradation and reduced oxidative stress in animals and humans.

Effects of statins on cardiorenal syndrome

Cardiovascular disease and renal disease have a close relationship that forms a vicious cycle as a cardiorenal syndrome (CRS). Oxidative stress, endothelial dysfunction, and vascular inflammation could be therapeutic targets when the renin-angiotensin-aldosterone system is activated by accumulation of conventional cardiovascular risk factors; however, a strategy for management of CRS has not been established yet. Statins, HMG-CoA reductase inhibitors, have not only cholesterol-lowering effects but also pleiotropic effects on cardiovascular systems, including anti-inflammatory and antioxidant effects and improvement of nitric oxide bioavailability. Since recent studies have indicated that statins have beneficial effects on chronic kidney disease and heart failure as well as coronary artery disease in cholesterol-lowering-dependent/independent manners, treatment with statins might be a successful strategy for preventing deterioration of CRS.

Heart angiotensin II-induced cardiomyocyte hypertrophy suppresses coronary angiogenesis and progresses diabetic cardiomyopathy

To examine whether and how heart ANG II influences the coordination between cardiomyocyte hypertrophy and coronary angiogenesis and contributes to the pathogenesis of diabetic cardiomyopathy, we used Spontaneously Diabetic Torii (SDT) rats treated without and with olmesartan medoxomil (an ANG II receptor blocker). In SDT rats, left ventricular (LV) ANG II, but not circulating ANG II, increased at 8 and 16 wk after diabetes onset. SDT rats developed LV hypertrophy and diastolic dysfunction at 8 wk, followed by LV systolic dysfunction at 16 wk, without hypertension. The SDT rat LV exhibited cardiomyocyte hypertrophy and increased hypoxia-inducible factor-1α expression at 8 wk and to a greater degree at 16 wk and interstitial fibrosis at 16 wk only. In SDT rats, coronary angiogenesis increased with enhanced capillary proliferation and upregulation of the angiogenic factor VEGF at 8 wk but decreased VEGF with enhanced capillary apoptosis and suppressed capillary proliferation despite the upregulation of VEGF at 16 wk. In SDT rats, the phosphorylation of VEGF receptor-2 increased at 8 wk alone, whereas the expression of the antiangiogenic factor thrombospondin-1 increased at 16 wk alone. All these events, except for hyperglycemia or blood pressure, were reversed by olmesartan medoxomil. These results suggest that LV ANG II in SDT rats at 8 and 16 wk induces cardiomyocyte hypertrophy without affecting hyperglycemia or blood pressure, which promotes and suppresses coronary angiogenesis, respectively, via VEGF and thrombospondin-1 produced from hypertrophied cardiomyocytes under chronic hypoxia. Thrombospondin-1 may play an important role in the progression of diabetic cardiomyopathy in this model.

Pravastatin reduces steroid-induced osteonecrosis of the femoral head in SHRSP rats

BACKGROUND AND PURPOSE

Although the definite cause of steroid-induced osteonecrosis of the femoral head (ONFH) is unknown, peripheral circulatory failure, lipid metabolism disturbance, and increased oxidative stress are considered to be possible causes. We investigated whether pravastatin as a statin treatment reduces (1) the incidence of ONFH, (2) the adipocyte area, and (3) bone marrow changes in the femoral head.

METHODS

We divided up 81 thirteen-week-old spontaneously hypertensive stroke-prone (SHRSP)/Izm male rats into 4 groups: a control group (group C), a group given pravastatin (group P), a group given steroid (group S), and a group given both pravastatin and steroid (Group PS). The steroid was administered at 15 weeks of age. Pravastatin, as a statin, was administered in the drinking water for 4 weeks. The rats were killed when 17 weeks old. Osteonecrosis was diagnosed based on histopathological examination. Oxidative stress was assessed from immunostaining.

RESULTS

The incidence of histological osteonecrosis was lower in the groups given pravastatin. The percentage of adipocyte area in the bone marrow was lower in the PS group than in the S group. Immunohistochemical staining for oxidative stress showed that staining was less in the PS group than in the S group. Pravastatin had no effect on the blood-derived biochemical findings on lipid metabolism. However, it reduced the incidence of steroid-induced ONFH in these SHRSP rats. We presume that this occurred by reducing oxidative stress and by reducing the percentage of adipocyte area in the femoral heads.

INTERPRETATION

Our data suggest that pravastatin may be effective in reducing steroid-induced ONFH.

In vivo cardioprotection by pitavastatin from ischemic-reperfusion injury through suppression of IKK/NF-κB and upregulation of pAkt-e-NOS

Recent studies have uncovered the beneficial effects of statin in cardiovascular diseases; however, the role of pitavastatin in ischemia-reperfusion (IR)-induced apoptosis and myocardial damage is not established. Therefore, in this study, we aim to investigate whether pitavastatin treatment attenuates myocardial IR injury via regulating oxidative stress, inflammation, apoptosis, and phosphorylated protein kinase B (pAkt) endothelial nitric oxide synthase (e-NOS) pathways. After the 14-day treatment with pitavastatin (0.16-0.64 mg·kg·d, po) or saline, rats were subjected to 45 minutes of ischemia by occluding the left anterior descending coronary artery and to 60 minutes of reperfusion to induce myocardial damage. Pitavastatin at a dose of 0.32 and 0.64 mg/kg significantly improved cardiac function as evidenced by the normalization of the mean arterial pressure, heart rate, ±LVdP/dtmax, and left ventricular end-diastolic pressure as compared with the IR control. Additionally, pitavastatin dose-dependently normalized myocardial antioxidants, lactate dehydrogenase, and thiobarbituric acid reactive substances along with decreased serum tumor necrosis factor-α level and creatine kinase isoenzyme-MB activity. Furthermore, pitavastatin enhanced pAkt, (p) e-NOS, Bcl-2, and suppressed IκB kinase/nuclear factor-kappa B, nitrotyrosine (NO inactivation product), Bax, and capases-3 protein expression in the heart. Morphological assessments of the IR-challenged myocardium showed that 0.32 and 0.64 mg/kg of pitavastatin decrease myocardial necrosis and inflammatory changes. Thus, pitavastatin reduced IR-induced infarction and dysfunction via the augmentation of endogenous antioxidant, suppression of IκB kinase/nuclear factor-kappa B, activation of pAkt-e-NOS, and/or decreased NO inactivation and apoptosis.

Lentil polyphenol extract prevents angiotensin II-induced hypertension, vascular remodelling and perivascular fibrosis

The objective of the study was to investigate whether chronic administration of the Morton lentil polyphenol extract (MLPE), which possesses rich phenolic compounds and a high antioxidant activity, had any protective effects on angiotensin II-induced hypertension. After four weeks of subcutaneous infusion of angiotensin II (200 ng kg(-1) min(-1)) in male SD rats, the water intake and mean artery pressure was significantly increased by 39.8% and 48.3%, respectively, as compared with the control. The media/lumen ratio of the small arteries in the heart and kidneys were increased by 117% and 168% by angiotensin II infusion. The perivascular fibrosis was increased by 65% and 32% in the heart and kidneys, respectively. Levels of the reactive oxygen species in the aorta was enhanced by 115.8%. In another group of rats, which received four weeks of lentil extract administration (1% freeze-dried MLPE in the drinking water), followed by another four weeks of extract administration plus angiotensin II infusion, the angiotensin II-induced enhancement in water intake and mean artery pressures decreased by 12.7% and 8.2%, respectively, as compared with the rats that received angiotensin II infusion alone. The angiotensin II-induced rats showed increases in the media/lumen ratios which were attenuated by 43.6% and 47.2% in the small arteries of heart and kidneys, respectively. Angiotensin II-induced perivascular fibrosis was attenuated by 30% and 26% in the rats that received the extract. Angiotensin II-induced rats showed reactive oxygen species levels in the aorta was reduced by 48.9%. These findings demonstrated that lentil extract attenuated angiotensin II-induced hypertension and associated pathological changes, including remodelling and perivascular fibrosis in the small resistant arteries of heart and kidneys.

Statins reverse renal inflammation and endothelial dysfunction induced by chronic high salt intake

High salt intake (HS) is a risk factor for cardiovascular and kidney disease. Indeed, HS may promote blood-pressure-independent tissue injury via inflammatory factors. The lipid-lowering 3-hydroxy 3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors exert beneficial lipid-independent effects, reducing the expression and synthesis of inflammatory factors. We hypothesized that HS impairs kidney structure and function in the absence of hypertension, and these changes are reversed by atorvastatin. Four groups of rats were treated for 6 wk in metabolic cages with their diets: normal salt (NS); HS, NS plus atorvastatin and HS plus atorvastatin. We measured basal and final body weight, urinary sodium and protein excretion (UProtV), and systolic blood pressure (SBP). At the end of the experimental period, cholesterolemia, creatinine clearance, renal vascular reactivity, glomerular volume, cortical and glomerular endothelial nitric oxide synthase (eNOS), and transforming growth factor (TGF)-β1 expression were measured. We found no differences in SBP, body weight, and cholesterolemia. HS rats had increased creatinine clearence, UProtV, and glomerular volume at the end of the study. Acetylcholine-induced vasodilatation decreased by 40.4% in HS rats ( P < 0.05). HS decreased cortical and glomerular eNOS and caused mild glomerular sclerosis, interstitial mononuclear cell infiltration, and increased cortical expression of TGF-β1. All of these salt-induced changes were reversed by atorvastatin. We conclude that long-term HS induces inflammatory and hemodynamic changes in the kidney that are independent of SBP. Atorvastatin corrected all, suggesting that the nitric oxide-oxidative stress balance plays a significant role in the earlier stages of salt induced kidney damage.

Inhibition of mineralocorticoid receptor is a renoprotective effect of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor pitavastatin

OBJECTIVE

The mineralocorticoid receptor has been implicated in the pathogenesis of chronic cardiorenal disease. Statins improve renal remodeling and dysfunction in patients with proteinuric kidney diseases. We aimed to clarify the beneficial effects and mechanisms of action of statins in renal insufficiency.

METHODS AND RESULTS

Dahl salt-sensitive rats fed a high-salt diet were treated from 12 to 20 weeks of age with vehicle, the reduced nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase inhibitor apocynin, the synthetic cathepsin inhibitor E64d, or a low or high dosage of pitavastatin (1 or 3 mg/kg daily). Rats fed a low-salt diet served as controls. Rats on the high-salt diet developed massive proteinuria and glomerulosclerosis; these changes were attenuated by both doses of pitavastatin. The amounts of mRNAs or proteins for mineralocorticoid receptor, angiotensin-converting enzyme, angiotensin II type 1 receptor (AT1R), monocyte chemoattractant protein-1, osteopontin, macrophage infiltration, and NADPH subunits (gp91phox, p22phox, and Rac1) were significantly higher in the failing kidneys of vehicle-treated rats than in the kidneys of control rats. Either dose of pitavastatin significantly attenuated these changes. These effects of pitavastatin were mimicked by those of apocynin and E64d. Pretreatment with pitavastatin and apocynin inhibited mRNA and protein of mineralocorticoid receptor induced by angiotensin II in cultured podocytes.

CONCLUSION

The beneficial effects of pitavastatin are likely attributable, at least in part, to attenuation of the mineralocorticoid receptor-dependent inflammatory mediator, matrix protein, and cathepsin expressions induced by AT1R-mediated NADPH oxidase activation in the kidneys of a salt-induced hypertensive Dahl salt-sensitive rat model.

Effect of low-dose (1 mg/day) pitavastatin on left ventricular diastolic function and albuminuria in patients with hyperlipidemia

The aim of the present study was to evaluate the factors that modulate the protective action of statins on cardiorenal function, regardless of the lipid-lowering effect. To treat abnormal serum lipid profiles, low-dose pitavastatin (1.0 mg/day) was administered to 65 hyperlipidemic patients. The exclusion criteria included left ventricular ejection fraction <40% and apparent renal disease. Age- and gender-matched patients with hyperlipidemia (n = 40) served as the controls. After 12 to 16 weeks of pitavastatin treatment, pitavastatin had decreased low-density lipoprotein cholesterol (from 143.5 ± 31.4 to 98.2 ± 19.4 mg/dl, p <0.01), triglycerides (from 157.7 ± 57.2 to 140.5 ± 60.7 mg/dl, p <0.01), E/e' (from 10.8 ± 6.2 to 9.0 ± 4.5, p <0.05), a parameter of left ventricular diastolic function, and albuminuria (from 47.6 ± 55.9 to 28.5 ± 40.0 mg/g creatinine, p <0.01). Furthermore, pitavastatin decreased serum transforming growth factor-β1 (from 709 ± 242 to 550 ± 299 pg/ml, p <0.01), urinary 8-hydroxy-2'-deoxyguanosine (from 6.6 ± 4.1 to 5.0 ± 3.1 μg/g creatinine, p <0.01), an oxidative stress marker, and increased urinary nitrate and nitrite (from 22.5 ± 14.6 to 29.4 ± 27.6 nmol/g creatinine, p <0.05). No such changes were observed in the controls. Multiple regression analysis in the pitavastatin group revealed the effect of pitavastatin on cardiorenal function was associated with suppression of oxidative stress, but not on low-density lipoprotein cholesterol reduction. In conclusion, pitavastatin decreases E/e' and albuminuria, which is associated with suppression of oxidative stress.

Pitavastatin inhibits hepatic steatosis and fibrosis in non-alcoholic steatohepatitis model rats

AIM

  Non-alcoholic steatohepatitis (NASH) may progress to liver cirrhosis, and NASH patients with liver cirrhosis are at risk of developing hepatocellular carcinoma. Statins, 3-hydroxy-3-methyglutaryl-coenzyme A reductase inhibitors, are well known to reduce low-density lipoprotein cholesterol and reduce the incidence of coronary heart disease and other major vascular events by anti-inflammatory and antifibrotic effects, and antiproliferative properties in colorectal cancers have also been reported. Recently, statins have been reported to improve hepatic steatosis; however, the effect on fibrosis is controversial.

METHODS

  The effects of pitavastatin (one of the strongest statins) were examined using a choline-deficient L-amino acid-defined (CDAA) diet liver fibrosis model.

RESULTS

  Pitavastatin significantly attenuated increases in serum aspartate aminotransferase, alanine aminotransferase, hepatic steatosis, oxidative stress, pre-neoplastic lesions (glutathione S-transferase placental form-positive lesions), expression of cytokines, such as tumor necrosis factor-α and transforming growth factor-β1, and the expression of tissue inhibitor of metalloproteinase-1, tissue inhibitor of metalloproteinase-2 and type I procollagen genes followed by attenuating fibrosis of the liver of CDAA-fed rats.

CONCLUSION

  These results indicate that pitavastatin may inhibit steatosis, hepatic fibrosis and carcinogenesis in rat model of NASH.

Pentosan reduces osteonecrosis of femoral head in SHRSP

Increased oxidative stress is considered one of the main causes of steroid-induced osteonecrosis of the femoral head (ONFH). The aim of this study was to evaluate the effects of a steroid hormone and pentosan polysulfate sodium (pentosan), a heparin analog, in stroke-prone spontaneously hypertensive rats (SHRSP) as a model of ONFH. One hundred twenty-three 13-week-old male SHRSP/Izm rats were divided into four groups: a control group (group C), pentosan-administered group (group P), steroid-administered group (group S), and group administered pentosan plus steroid (group PS). Methylprednisolone acetate, as the steroid hormone, at a dose of 4 mg (15 mg/kg) was administered at 15 weeks of age. Pentosan at a dose of 3 mg/day/kg was continuously administered intraperitoneally from 13 weeks of age for 4 weeks. Rats were sacrificed at 17 weeks of age, and heart blood and both femora were collected. Triglyceride levels were significantly lower in group PS than in group S, indicating that pentosan improves lipid metabolism. The incidence of histologic ONFH was significantly lower in group P, at 14.8% (10/71 femoral heads), than in group C, at 30.4% (17/56 femoral heads), and significantly lower in group PS, at 40.8% (29/71 femoral heads), than in group S, at 91.3% (42/46 femoral heads), indicating that pentosan markedly inhibits ONFH. Immunohistochemical staining for oxidative stress showed that the stainability was significantly lower in group PS than in group S. Pentosan seems to reduce the incidence of ONFH in SHRSP by improving lipid metabolism and decreasing oxidative stress.

Inhibition of mineralocorticoid receptor is a renoprotective effect of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor pitavastatin

OBJECTIVE

The mineralocorticoid receptor has been implicated in the pathogenesis of chronic cardiorenal disease. Statins improve renal remodeling and dysfunction in patients with proteinuric kidney diseases. We aimed to clarify the beneficial effects and mechanisms of action of statins in renal insufficiency.

METHODS AND RESULTS

Dahl salt-sensitive rats fed a high-salt diet were treated from 12 to 20 weeks of age with vehicle, the reduced nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase inhibitor apocynin, the synthetic cathepsin inhibitor E64d, or a low or high dosage of pitavastatin (1 or 3 mg/kg daily). Rats fed a low-salt diet served as controls. Rats on the high-salt diet developed massive proteinuria and glomerulosclerosis; these changes were attenuated by both doses of pitavastatin. The amounts of mRNAs or proteins for mineralocorticoid receptor, angiotensin-converting enzyme, angiotensin II type 1 receptor (AT1R), monocyte chemoattractant protein-1, osteopontin, macrophage infiltration, and NADPH subunits (gp91phox, p22phox, and Rac1) were significantly higher in the failing kidneys of vehicle-treated rats than in the kidneys of control rats. Either dose of pitavastatin significantly attenuated these changes. These effects of pitavastatin were mimicked by those of apocynin and E64d. Pretreatment with pitavastatin and apocynin inhibited mRNA and protein of mineralocorticoid receptor induced by angiotensin II in cultured podocytes.

CONCLUSION

The beneficial effects of pitavastatin are likely attributable, at least in part, to attenuation of the mineralocorticoid receptor-dependent inflammatory mediator, matrix protein, and cathepsin expressions induced by AT1R-mediated NADPH oxidase activation in the kidneys of a salt-induced hypertensive Dahl salt-sensitive rat model.

Lipid peroxidation-induced VEGF expression in the skin of KKAy obese mice

Obesity is known to be associated with a number of effects on skin physiology. KKA(y) obese mouse is a model of type 2 diabetes characterized by systemic oxidative stress because of severe obesity, hypertriglyceridaemia, hyperglycaemia and hyperinsulinaemia. We investigated lipid peroxidation and vascular endothelial growth factor (VEGF) expression in the skin of KKA(y) obese mice. We also investigated the effect of lipid peroxidation derivatives on VEGF production and proliferation in human epidermal keratinocyte cell line (HaCaT). The lipid peroxidation level in the mouse skin tissue was determined by measuring the levels of thiobarbituric acid-reactive substances. The levels of VEGF expression, p44/p42 mitogen-activated protein kinase (MAPK) activation and CD36 expression were analysed by Western blot. Their localization was examined by immunofluorescence. For the in vitro experiments, an enzyme-linked immunosorbent assay was utilized to measure VEGF secretion in the medium. In vitro experiments demonstrated that lipid peroxidation derivatives increased VEGF production in HaCaT cells, which was blocked by a p44/p42 MAPK inhibitor and anti-CD36 antibody. We observed increased levels of lipid peroxidation derivatives, p44/p42 MAPK activation and VEGF expression in the skin of KKA(y) obese mice. Notably, pitavastatin, an inhibitor of competitive 3-hydroxy-3-methylglutaryl coenzyme A reductase, suppressed all of these processes. Our results suggest that lipid peroxidation induces VEGF expression via CD36 and p44/p42 MAPK pathway in the skin of obese mice.

Inhibition of the renal renin-angiotensin system and renoprotection by pitavastatin in type1 diabetes

1. The aim of the present study was to investigate whether or not pitavastatin ameliorates diabetic nephropathy and if inhibition of the rennin-angiotensin-aldosterone system (RAAS) is associated with any renoprotective effects. Pitavastatin (10mg/ kg/day) and/or spironolactone (100mg/kg/day) were given by gavage for 3weeks to uninephrectomized rats with streptozotocin-induced diabetes. 2. Pitavastatin or spironolactone significantly reduced proteinuria and collagen deposition, and normalized creatinine clearance, serum creatinine levels and blood urea nitrogen concentrations. 3. Reverse transcription polymerase chain reaction analysis showed that the renal expression of collagenI, transforming growth factor-β and monocyte chemoattractant-1 were increased in diabetic rats and reduced by the pitavastatin and/or spironolactone treatment. 4. These agents also decreased angiotensin converting enzyme expression and aldosterone concentrations in the renal homogenate, but had no effect on blood glucose, haemoglobinA(1c) , and plasma total cholesterol, Na(+) , K(+) , aldosterone and NOx levels, or on systolic blood pressure measured by the tail-cuff method. Interestingly, cotreatment with pitavastatin and spironolactone did not result in additional normalization. 5. These results suggest that pitavastatin shows renoprotective effects against diabetic nephropathy mediated in part by inhibition of the renal RAAS, including the suppression of angiotensin-converting enzyme expression and aldosterone production.

Transforming Growth Factor-β1 as a Common Target Molecule for Development of Cardiovascular Diseases, Renal Insufficiency and Metabolic Syndrome

Transforming growth factor-β1 (TGF-β1) is a polypeptide member of the transforming growth factor β superfamily of cytokines. It is a secreted protein that performs many cellular functions including control of cell growth, cell proliferation, cell differentiation and apoptosis. In the cardiovascular system, TGF-β1 plays pivotal roles in the pathogenesis of hypertension, restenosis after percutaneous coronary intervention, atherosclerosis, cardiac hypertrophy and heart failure. In addition, TGF-β1 has been shown to be increased in adipose tissue of obese subjects with insulin resistance. Furthermore, TGF-β1 is a potent initiator of proliferation of renal mesangial cells leading to chronic kidney disease. Some currently available agents can manipulate TGF-β1 expression leading to amelioration of cardiovascular diseases. Thus, an understanding of interactions between chronic kidney disease and metabolic syndrome and the development of cardiovascular diseases is an important issue, and attention should be given to TGF-β1 as a crucial factor for regulation and modulation of those pathological conditions.

Statins inhibit angiotensin II/Smad pathway and related vascular fibrosis, by a TGF-β-independent process

We have recently described that in an experimental model of atherosclerosis and in vascular smooth muscle cells (VSMCs) statins increased the activation of the Smad pathway by transforming growth factor-β (TGF-β), leading to an increase in TGF-β-dependent matrix accumulation and plaque stabilization. Angiotensin II (AngII) activates the Smad pathway and contributes to vascular fibrosis, although the in vivo contribution of TGF-β has not been completely elucidated. Our aim was to further investigate the mechanisms involved in AngII-induced Smad activation in the vasculature, and to clarify the beneficial effects of statins on AngII-induced vascular fibrosis. Infusion of AngII into rats for 3 days activates the Smad pathway and increases fibrotic-related factors, independently of TGF-β, in rat aorta. Treatment with atorvastatin or simvastatin inhibited AngII-induced Smad activation and related-fibrosis. In cultured rat VSMCs, direct AngII/Smad pathway activation was mediated by p38 MAPK and ROCK activation. Preincubation of VSMCs with statins inhibited AngII-induced Smad activation at all time points studied (from 20 minutes to 24 hours). All these data show that statins inhibited several AngII-activated intracellular signaling systems, including p38-MAPK and ROCK, which regulates the AngII/Smad pathway and related profibrotic factors and matrix proteins, independently of TGF-β responses. The inhibitory effect of statins on the AngII/Smad pathway could explain, at least in part, their beneficial effects on hypertension-induced vascular damage.

Heparin cofactor II protects against angiotensin II-induced cardiac remodeling via attenuation of oxidative stress in mice

Heparin cofactor II (HCII), a serine protease inhibitor, inhibits tissue thrombin action after binding with dermatan sulfate proteoglycans in the extracellular matrix of the vascular system. We previously reported that heterozygous HCII-deficient (HCII(+/-)) humans and mice demonstrate acceleration of vascular remodeling, including atherosclerosis. However, the action of HCII on cardiac remodeling never has been determined. HCII(+/+) and HCII(+/-) mice at age 25 weeks were infused with angiotensin II (Ang II; 2.0 mg/kg/d) for 2 weeks by an osmotic mini-pump. Echocardiography revealed acceleration of cardiac concentric remodeling in HCII(+/-) mice and larger left atrial volume in HCII(+/-) mice than in HCII(+/+) mice. Histopathologic studies showed more prominent interstitial fibrosis in both the left atrium and left ventricle in HCII(+/-) mice than in HCII(+/+) mice. Daily urinary excretion of 8-hydroxy-2'-deoxyguanosine, a parameter of oxidative stress, and dihydroethidium-positive spots, indicating superoxide production in the myocardium, were markedly increased in Ang II-treated HCII(+/-) mice compared to those in HCII(+/+) mice. Cardiac gene expression levels of atrial natriuretic peptides and brain natriuretic peptides, members of the natriuretic peptide family, Nox 4, Rac-1, and p67(phox) as components of NAD(P)H oxidase, and transforming growth factor-beta1 and procollagen III were more augmented in HCII(+/-) mice than in HCII(+/+) mice. However, administration of human HCII protein attenuated all of those abnormalities in Ang II-treated HCII(+/-) mice. Moreover, human HCII protein supplementation almost abolished cardiac fibrosis in Ang II-treated HCII(+/+) mice. The results indicate that HCII has a protective role against Ang II-induced cardiac remodeling through suppression of the NAD(P)H oxidase-transforming growth factor-beta1 pathway.