Fluvastatin inhibits O2- and ICAM-1 levels in a rat model with aortic remodeling induced by pressure overload

Effect of statins on toll-like receptors: a new insight to pleiotropic effects

The toll-like receptors (TLRs) are a class of transmembrane-spanning receptors that are sentinels of both innate and adaptive immunity. Statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) are the most commonly prescribed therapeutic agents for treating hypercholesterolemia globally. However, statin therapy appears to have pleiotropic effects including attenuation of chronic low-grade inflammation and modulation of TLR activity. Statins through abolition of TLR4 expression and regulation of the TLR4/Myd88/NF-κB signaling pathway may slow the progression of atherosclerosis and other inflammatory diseases. In this review, we have focused on the impact and mechanism of action of statins on cardiovascular and non-cardiovascular diseases.

Fluvastatin-induced reduction of oxidative stress ameliorates diabetic cardiomyopathy in association with improving coronary microvasculature

Diabetic cardiomyopathy is associated with increased oxidative stress and vascular endothelial dysfunction, which lead to coronary microangiopathy. We tested whether statin-induced redox imbalance improvements could ameliorate diabetic cardiomyopathy and improve coronary microvasculature in streptozotocin-induced diabetes mellitus (DM). Fluvastatin (10 mg/kg/day) or vehicle was orally administered for 12 weeks to rats with or without DM. Myocardial oxidative stress was assessed by NADPH (nicotinamide adenine dinucleotide phosphate) oxidase subunit p22(phox) and gp91(phox) mRNA expression, and myocardial 8-iso-prostaglandin F(2α) (PGF(2α)) levels. Myocardial vascular densities were assessed using anti-CD31 and anti-α-smooth muscle actin (SMA) antibodies. Fluvastatin did not affect blood pressure or plasma cholesterol, but attenuated increased left ventricular (LV) minimum pressure and ameliorated LV systolic dysfunction in DM rats in comparison with vehicle (LV dP/dt, 8.9 ± 1.8 vs 5.4 ± 1.0 × 10(3) mmHg/s, P < 0.05). Myocardial oxidative stress increased in DM, but fluvastatin significantly reduced p22(phox) and gp91(phox) mRNA expression and myocardial PGF(2α) levels. Fluvastatin enhanced myocardial endothelial nitric oxide synthase (eNOS) protein levels and increased eNOS, vascular endothelial growth factor, and hypoxia-inducible factor-1α mRNA expression. CD31-positive cell densities were lower in DM rats than in non-DM rats (28.4 ± 13.2 vs 48.6 ± 4.3/field, P < 0.05) and fluvastatin restored the number (57.8 ± 18.3/field), although there were no significant differences in SMA-positive cell densities between groups. Fluvastatin did not affect cardiac function, oxidative stress, or vessel densities in non-DM rats. These results suggest that beneficial effects of fluvastatin on diabetic cardiomyopathy might result, at least in part, from improving coronary microvasculature through reduction in myocardial oxidative stress and upregulation of angiogenic factor.

Heme oxygenase-1 transgenic overexpression did not prevent artery injury induced by electric stimulation and pressure overload in mice

Heme oxygenase-1 (HO-1) shows multiple beneficial effects on cardiovascular diseases. However, the effect of HO-1 on the injury of artery has never been identified. In the present study, we established systemic HO-1 overexpression transgenic mice and investigated the effect of HO-1 on the injury of artery induced by electric stimulation and pressure-overload in transgenic mice. Artery injury was induced by electric stimulation and pressure overload. The contractive function, endothelium-dependent and -independent relaxation of arteries were measured through an isometric force transducer connected to a multichannel acquisition and analysis system. Western blot results showed that HO-1 protein level in transgenic mice arteries was significantly higher than that in wild type mice arteries, while no difference of HO-2 protein level in the arteries of transgenic and wild type mice. Arterial reendothelialization after electric injury was accelerated in transgenic mice. No significant difference in contractive function, endothelium-dependent and -independent relaxation of arteries was observed between wild type and transgenic mice at day 7 after electric injury and 4 weeks after pressure overload. We concluded that HO-1 overexpression accelerated the reendothelialization, but did not prevent the functional impairment of injured artery in mice.

Fluvastatin attenuates diabetes-induced cardiac sympathetic neuropathy in association with a decrease in oxidative stress

BACKGROUND

Increased oxidative stress might contribute to diabetic (DM) neuropathy, so the effects of long-term treatment with fluvastatin (FL) on myocardial oxidative stress and cardiac sympathetic neural function were investigated in diabetic rats.

METHODS AND RESULTS

FL (10 mg . kg(-1) . day(-1), DM-FL) or vehicle (DM-VE) was orally administered for 2 weeks to streptozotocin-induced DM rats. Cardiac oxidative stress was determined by myocardial 8-iso-prostaglandin F(2alpha) (PGF(2alpha)) and NADPH oxidase subunit p22(phox) mRNA expression. Sympathetic neural function was quantified by autoradiography using (131)I- and (125)I-metaiodobenzylguanidine (MIBG). FL did not affect plasma glucose levels but remarkably decreased PGF(2alpha) levels compared with DM-VE rats (13.8+/-9.2 vs 175.0+/-93.9 ng/g tissue), although PGF(2alpha) levels were below the detection limit in non-DM rats. FL significantly reduced myocardial p22(phox) mRNA expression. Cardiac (131)I-MIBG uptake was lower in DM-VE rats than in non-DM rats, but the decrease was attenuated in DM-FL rats (1.31+/-0.08, 1.88+/-0.22, and 1.58+/-0.18 %kg dose/g, respectively, P<0.01). Cardiac MIBG clearance was not affected by the induction of DM or by FL, indicating that the reduced MIBG uptake in DM rats might result from impaired neural function.

CONCLUSIONS

FL ameliorates cardiac sympathetic neural dysfunction in DM rats in association with attenuation of increased myocardial oxidative stress.

Transgenic expression of matrix metalloproteinase-1 inhibits myocardial fibrosis and prevents the transition to heart failure in a pressure overload mouse model

Hypertension induces dysfunctional matrix remodeling that results in the development of myocardial fibrosis. Myocardial fibrosis adversely affects compliance, electrical activity and cardiac function in patients with hypertensive heart disease. Matrix metalloproteinases (MMPs) are a class of enzymes that regulate the remodeling of the matrix in response to pressure overload. Several studies have shown that the MMP-1/TIMP (tissue inhibitor of matrix metalloproteinase) ratio is decreased in hypertensive heart disease. However, the exact role that MMP-1 has in modulating the fibrotic response to hypertension is largely unknown. We hypothesized that cardiac expression of MMP-1 in mice would protect against the development of dysfunctional matrix remodeling during pressure overload. To investigate this, a suprarenal aortic banding model was utilized. Banded and unbanded MMP-1 transgenic mice were compared with appropriately matched wild-type mice. The banded mice were examined at 2 and 5 weeks after banding. MMP-1 attenuated the development of cardiac fibrosis, prevented left ventricular dilation and preserved cardiac function in mice that were exposed to pressure overload. Thus, MMP-1 protected the heart from the dysfunctional remodeling that occurs in response to chronic hypertension. In conclusion, these results suggest that strategies aimed at improving the MMP-1/TIMP balance in the myocardium may help to prevent the onset and progression of hypertensive heart disease.

Chronic fluvastatin treatment alters vascular contraction by inhibiting the Rho/Rho-kinase pathway

1. In the present study, we investigated the effects of chronic treatment of stroke-prone spontaneously hypertensive rats (SHRSP) with the statin fluvastatin on vascular Rho/Rho-kinase pathway mediated contraction, which has been shown to be upregulated in hypertension. 2. Contribution of the Rho/Rho-kinase pathway to noradrenaline-induced contraction of arteries from SHRSP was assessed by the inhibitory effect of Y-27632, a Rho/Rho-kinase inhibitor. Stroke-prone spontaneously hypertensive rats were treated with fluvastatin (10 mg/kg per day) for 1 month. 3. Treatment with fluvastatin tended to attenuate the contraction to noradrenaline and significantly decreased the Y-27632-sensitive component of the contraction in controls compared with fluvastatin-treated rats. 4. RhoA, as assessed by western blotting, was also reduced by fluvastatin treatment. 5. These findings suggest that chronic treatment with fluvastatin reduces the contractile response associated with Rho/Rho-kinase in arteries of hypertensive rats.

Fluvastatin reverses endothelial dysfunction and increased vascular oxidative stress in rat adjuvant-induced arthritis

OBJECTIVE

To investigate the effect of statins on vascular dysfunction in rat adjuvant-induced arthritis (AIA).

METHODS

Fluvastatin (5 mg/kg/day) was administered orally to rats with AIA, for 21 days after the onset of arthritis. The vasodilatory response to acetylcholine of aortic rings isolated from rats with AIA that were not treated or were treated with fluvastatin and from normal rats was determined. The amounts of 4-hydroxy-2-nonenal (HNE) and nitrotyrosine in aortas were measured by Western blotting. In vitro and in situ superoxide production in aortas was evaluated based on fluorogenic oxidation of dihydroethidium to ethidium. Expression of NAD(P)H components and endothelial nitric oxide synthase (eNOS) in aortas was examined by real-time reverse transcriptase-polymerase chain reaction and Western blotting. Serum levels of tetrahydrobiopterin, a critical eNOS cofactor, were determined by high-performance liquid chromatography.

RESULTS

Fluvastatin reversed endothelial dysfunction in AIA without affecting the clinical severity of arthritis or serum cholesterol concentration. Fluvastatin reduced the amounts of HNE and nitrotyrosine in the aorta, and the levels of superoxide expressed in endothelial cells and smooth muscle cells in the tissue, in rats with AIA. NADH- or L-arginine-induced superoxide production was not observed in the aortic samples from fluvastatin-treated rats with AIA. Fluvastatin decreased the levels of expression of messenger RNA for p22phox, a NAD(P)H oxidase component, in the aortas of rats with AIA, but did not affect the expression of eNOS. Serum levels of tetrahydrobiopterin were significantly reduced in rats with AIA, and were increased by administration of fluvastatin.

CONCLUSION

Our findings demonstrate that fluvastatin has potent vascular protective effects in AIA and provide additional scientific rationale for the use of statins to reduce cardiovascular mortality in patients with rheumatoid arthritis.

Statins and the vascular endothelial inflammatory response

Statins reduce cholesterol synthesis and are widely used for the treatment of hyperlipidaemia and ischaemic heart disease. Besides their cholesterol-lowering effects, statins also possess broad immunomodulatory and anti-inflammatory properties. Vascular endothelial cells have a crucial role in the pathogenesis of inflammatory disease, and, alongside leukocytes and antigen-presenting cells, represent a key cellular target for statin therapy. Recent studies investigating how these drugs modify endothelial cell function demonstrate that the therapeutic effect of statins can be attributed, in part, to their action on the endothelium. Accordingly, statins attenuate endothelial MHC class II expression, increase endothelial nitric oxide synthase and fibrinolytic activity, decrease leukocyte adhesion and transmigration, and enhance resistance to local injurious stimuli. Many of these effects are brought about by the modulation of small GTPase function and the downregulation of proinflammatory gene expression.

Fluvastatin Ameliorates Podocyte Injury in Proteinuric RatsviaModulation of Excessive Rho Signaling

Statins have been reported to confer renoprotection in several experimental models of renal disease through pleiotropic actions. The roles of statins in glomerular podocytes have not been explored. The objective of this study was to evaluate the effects of fluvastatin on podocyte and tubulointerstitial injury in puromycin aminonucleoside (PAN)-induced nephrosis. PAN induced massive proteinuria and serum creatinine elevation on day 7, which were significantly suppressed by fluvastatin. Immunofluorescence studies of podocyte-associated proteins nephrin and podocin revealed diminished and discontinuous staining patterns in rats with PAN nephrosis, indicating severe podocyte injury. Fluvastatin treatment dramatically mitigated the abnormal staining profiles. Reduction of nephrin expression by PAN and its reversal by fluvastatin were confirmed by quantitative analyses. By electron microscopy, effacement of foot processes was ameliorated in fluvastatin-treated rats. Fluvastatin also mitigated tubulointerstitial damage in PAN nephrosis, with the repression of PAN-induced NF-kappaB and activator protein-1 activation in the kidneys. In addition, expression of activated membrane-bound small GTPase RhoA was markedly increased in the glomeruli of PAN nephrosis, which was inhibited by fluvastatin treatment. In cultured podocytes, fluvastatin suppressed PAN-evoked activation of RhoA and actin cytoskeletal reorganization. Furthermore, fasudil, a specific Rho-kinase inhibitor, successfully ameliorated PAN-induced podocyte damage and proteinuria. In summary, fluvastatin alleviated podocyte and tubulointerstitial injury in PAN nephrosis. The beneficial effects of fluvastatin on podocytes can be attributable to direct modulation of excessive RhoA activity. Our data suggest a therapeutic role for statins in clinical conditions that are relevant to podocyte injury.

Early Administration of Fluvastatin, but not at the Onset of Ischemia or Reperfusion, Attenuates Myocardial Ischemia-Reperfusion Injury Through the Nitric Oxide Pathway Rather Than Its Antioxidant Property

BACKGROUND

Three-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) are known to attenuate myocardial ischemia-reperfusion (IR) injury. Fluvastatin (FV) has a potent free radical scavenging action, but it is unclear whether the timing of FV administration could affect its cardioprotective effect or if the antioxidant property of FV might attenuate IR injury.

METHODS AND RESULTS

IR was induced in rats by left coronary artery occlusion for 30 min followed by 24-h reperfusion. The rats were divided into 4 groups: oral FV group (10 mg/kg per day for 2 weeks before ischemia); iv, FV group (10 mg/kg) before ischemia; iv, FV group (10 mg/kg) before reperfusion; and control group. Oxidative stress was evaluated by myocardial 8-hydroxydeoxyguanosine (8-OHdG) content. The area at risk did not different among the 4 groups. Pretreatment with FV for 2 weeks significantly reduced the infarct size by 28% as compared with the control group, but FV administered just before ischemia or reperfusion did not. Myocardial 8-OHdG content was not affected by FV. The infarct-sparing effect of FV was completely abolished by N(omega)-nitro-l-arginine methyl ester or wortmannin.

CONCLUSIONS

The present results indicate that pretreatment with FV, but not just before ischemia or reperfusion, attenuates IR injury primarily through the nitric oxide pathway, not through its antioxidant property.

Fluvastatin Ameliorates the Hyperhomocysteinemia-Induced Endothelial Dysfunction-The Antioxidative Properties of Fluvastatin-

BACKGROUND

Hyperhomocysteinemia induces vascular endothelial dysfunction, contributing to a predisposition to the onset and/or progression of atherosclerosis. The major mechanism suggested for the adverse effect of homocysteine on vascular function seems to involve oxidative stress. Thus, we hypothesized that the administration of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor fluvastatin, which is experimentally demonstrated to have antioxidative properties as one of its pleiotropic effects, is a useful strategy for eliminating the detrimental events induced by hyperhomocysteinemia.

METHODS AND RESULTS

In diet-induced hyperhomocysteinemic rats, we estimated oxidative stress and assessed endothelium-dependent vasodilatation. Hyperhomocysteinemia induced significant increases in urinary 8-isoprostaglandin F2alpha-III excretion and vascular superoxide generation, and impaired endothelium-dependent vasodilatation. Additional oral administration of the antioxidant fluvastatin or vitamin E, which normalized increased oxidative stress induced by hyperhomocysteinemia, ameliorated endothelial dysfunction.

CONCLUSIONS

Hyperhomocysteinemia, even mild to moderate, induces endothelial dysfunction through its oxidative effect. The antioxidant fluvastatin was able to cancel out the oxidative stress induced by hyperhomocysteinemia and ameliorate endothelial dysfunction. Clinical use of fluvastatin might be a potent strategy for eliminating the detrimental events induced by hyperhomocysteinemia as well as hyperlipidemia. In addition to lowering homocysteine by means of folate supplementation, administration of the antioxidants is expected to be a potentially effective anti-homocysteine therapy.

2-Cyclopenten-1-one and prostaglandin J2reduce restenosis after balloon angioplasty in rats: role of NF-κB

The aim of this study was to evaluate, using a rat model of balloon angioplasty, whether prostaglandin (PG) J(2) and 2-cyclopenten-1-one are able to reduce restenosis. We found that both PGJ(2) and 2-cyclopenten-1-one, administered by local application on carotid arteries, caused a dose-dependent inhibition of neointimal formation. Furthermore, both agents prevented vascular negative remodeling. The effect of these compounds on restenosis was correlated with an inhibition of nuclear factor-kappaB (NF-kappaB) activation as well as of intercellular adhesion molecule-1 (ICAM-1) protein expression in injured carotid arteries of control animals. Our results show that cyclopentenone PGs and their derivatives reduce restenosis and may have therapeutic relevance for the prevention of human restenosis.