Pitavastatin inhibits vascular smooth muscle cell proliferation by inactivating extracellular signal-regulated kinases 1/2

Involvement of Lysophospholipids in Pulmonary Vascular Functions and Diseases

Extracellular lysophospholipids (lysophosphatidic acid, lysophosphatidylcholine, sphingosine 1-phosphate, etc.), which are synthesized from phospholipids in the cell membrane, act as lipid mediators, and mediate various cellular responses in constituent cells in the respiratory system, such as contraction, proliferation, migration, and cytoskeletal organization. In addition to these effects, the expression of the adhesion molecules is enhanced by these extracellular lysophospholipids in pulmonary endothelial cells. These effects are exerted via specific G protein-coupled receptors. Rho, Ras, and phospholipase C (PLC) have been proven to be their signaling pathways, related to Ca2+ signaling due to Ca2+ dynamics and Ca2+ sensitization. Therefore, lysophospholipids probably induce pulmonary vascular remodeling through phenotype changes in smooth muscle cells, endothelial cells, and fibroblasts, likely resulting in acute respiratory distress syndrome due to vascular leak, pulmonary hypertension, and pulmonary fibrosis. Moreover, lysophospholipids induce the recruitment of inflammatory cells to the lungs via the enhancement of adhesion molecules in endothelial cells, potentially leading to the development of asthma. These results demonstrate that lysophospholipids may be novel therapeutic targets not only for injury, fibrosis, and hypertension in the lung, but also for asthma. In this review, we discuss the mechanisms of the effects of lysophospholipids on the respiratory system, and the possibility of precision medicine targeting lysophospholipids as treatable traits of these diseases.

Application of a Reactive Oxygen Species-Responsive Drug-Eluting Coating for Surface Modification of Vascular Stents

Stent implantation is the primary method used to treat coronary heart disease. However, it is associated with complications such as restenosis and late thrombosis. Despite surface modification being an effective way to improve the biocompatibility of stents, the current research studies are not focused on changes in the vascular microenvironment at the implantation site. In the present study, an adaptive drug-loaded coating was constructed on the surface of vascular stent materials that can respond to oxidative stress at the site of vascular lesions. Two functional molecules, epigallocatechin gallate (EGCG) and cysteine hydrochloride, were employed to fabricate a coating on the surface of 316L stainless steel. In addition, the coating was used as a drug carrier to load pitavastatin calcium. EGCG has antioxidant activity, and pitavastatin calcium can inhibit smooth muscle cell proliferation. Therefore, EGCG and pitavastatin calcium provided a synergistic anti-inflammatory effect. Moreover, the coating was cross-linked using disulfide bonds, which accelerated the release of the drug in response to reactive oxygen species. A positive correlation was observed between the rate of drug release and the degree of oxidative stress. Collectively, this drug-loaded oxidative stress-responsive coating has been demonstrated to significantly inhibit inflammation, accelerate endothelialization, and reduce the risk of restenosis of vascular stents in vivo.

Fluvastatin protects myocardial cells in mice with acute myocardial infarction through inhibiting RhoA/ROCK pathway

Protective effect of fluvastatin (Flu) on myocardial cells in mice with acute myocardial infarction (AMI) and the mechanism were explored. Forty C57B/L6 mice in similar physiological status were selected and randomly divided into sham operation (Sham) group (n=10), AMI group (n=10), Flu group (n=10) and Flu + Angiotensin II (Ang II) (Ang II) group (n=10). The pathological changes in heart tissues were detected via hematoxylin and eosin (H&E) staining, and apoptosis of myocardial cells was detected via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Moreover, the expression levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were determined using relevant kits, and the expression levels of Ras homolog gene family (Rho)-associated coiled-coil protein kinase 1 (ROCK1), ROCK2, B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax) and nuclear factor-κB (NF-κB) in the infarction region were determined using Western blotting. The infarction area in mice in Flu group was significantly smaller than that in AMI group. In AMI group, the level of MDA in the serum and infarction tissues was remarkably higher than that in Sham group (P<0.05), while that of SOD significantly declined (P<0.05). The level of MDA in Flu group was obviously lower than that in AMI group (P<0.05). The expression levels of Bax, NF-κB, ROCK1 and ROCK2 were obviously higher in AMI group than those in Sham group, while they were obviously lower in Flu group than those in AMI group (P<0.05). After the Rho member A (RhoA)/ROCK pathway agonist Ang II was added, the mitigation effect of Flu on myocardial apoptosis in the infarction region in AMI mice was evidently weakened. Flu mitigates AMI-induced myocardial apoptosis in mice, and the possible mechanism is that the inflammatory and oxidative stress responses activated and mediated by RhoA/ROCK are effectively inhibited.

Pitavastatin Exerts Potent Anti-Inflammatory and Immunomodulatory Effects via the Suppression of AP-1 Signal Transduction in Human T Cells

Statins inhibiting 3-hydroxy-3-methylglutaryl-CoA reductase are the standard treatment for hypercholesterolemia in atherosclerotic cardiovascular disease (ASCVD), mediated by inflammatory reactions within vessel walls. Several studies highlighted the pleiotropic effects of statins beyond their lipid-lowering properties. However, few studies investigated the effects of statins on T cell activation. This study evaluated the immunomodulatory capacities of three common statins, pitavastatin, atorvastatin, and rosuvastatin, in activated human T cells. The enzyme-linked immunosorbent assay (ELISA) and quantitative real time polymerase chain reaction (qRT-PCR) results demonstrated stronger inhibitory effects of pitavastatin on the cytokine production of T cells activated by phorbol 12-myristate 13-acetate (PMA) plus ionomycin, including interleukin (IL)-2, interferon (IFN)-γ, IL-6, and tumor necrosis factor α (TNF-α). Molecular investigations revealed that pitavastatin reduced both activating protein-1 (AP-1) DNA binding and transcriptional activities. Further exploration showed the selectively inhibitory effect of pitavastatin on the signaling pathways of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK), but not c-Jun N-terminal kinase (JNK). Our findings suggested that pitavastatin might provide additional benefits for treating hypercholesterolemia and ASCVD through its potent immunomodulatory effects on the suppression of ERK/p38/AP-1 signaling in human T cells.

Anti-asthmatic effect of pitavastatin through aerosol inhalation is associated with CD4+ CD25+ Foxp3+ T cells in an asthma mouse model

Statins are competitive inhibitors of 3-hydroxy-3-methylglutaryl-CoA (HMG-A) reductase, and studies have shown that statins also have anti-inflammatory and immunomodulatory properties. The purpose of this study was to investigate the anti-asthmatic effects of pitavastatin, a type of statin, in an asthma mouse model. Mice were sensitized and challenged with ovalbumin (OVA) to establish the asthma model. These mice were then treated with inhaled pitavastatin (5 mg/kg) or dexamethasone (2 mg/kg), the latter of which served as a positive control. The results of the study showed that pitavastatin reduced allergen-induced increases in airway resistance and alleviated bronchial tube thickness and goblet cell hyperplasia in lung tissues. In addition, the results showed that pitavastatin inhibited OVA-induced increases in eosinophil counts and total inflammatory cell counts in bronchoalveolar lavage fluid (BALF) and increased the percentage of CD4+ CD25+ Foxp3+ Treg in the BALF of asthmatic mice. IL-4 and IL-17 levels were decreased, whereas IFN-γ levels were significantly increased in the BALF of pitavastatin-treated mice compared with the BALF of OVA-challenged mice. These results suggest that pitavastatin has potential as a therapy for allergic airway disease and that its effects are associated with its ability to regulate CD4+ CD25+ Foxp3+ T cell counts.

Initiation of antiplatelet medication after surgical thrombectomy jeopardized arteriovenous graft longevity

INTRODUCTION

The efficacy of antiplatelet agents in preventing thrombosis in newly formed arteriovenous graft (AVG) in hemodialysis (HD) patients has been extensively examined. The aim of this study was to investigate the possible effect of initiation of antiplatelet medications on preventing AVG thrombosis recurrence after surgical thrombectomy for acute occlusion in HD patients. Whether post-operatively antiplatelet medications have protective effects on the patency or longevity of AVG after surgical thrombectomy in HD patients has not been investigated.

METHODS

We conducted a 4-year quasi-randomized study of the unassisted patency and AVG longevity for 213 HD patients with or without initiating antiplatelet drugs after receiving surgical thrombectomy for first episode of acute AVG thrombosis.

RESULTS

From the propensity-score-matched quasi-randomized study, initiation of antiplatelet drugs after first surgical thrombectomy in HD patients did not prevent the recurrence of surgical thrombectomy (log-rank p = 0.81), but significantly decreased the longevity of the access (log-rank p = 0.034). Multivariate Cox model demonstrated that prescription of antiplatelet drugs significantly increased the risk of graft failure (adjusted hazard ratio 2.13, p = 0.025).

CONCLUSIONS

Adjunctive prescription with antiplatelet medications in HD patients after surgical thrombectomy did not prevent recurrent thrombosis of AV access, but significantly jeopardized the longevity of AVG after surgical thrombectomy.

Pitavastatin Regulates Ang II Induced Proliferation and Migration via IGFBP-5 in VSMC

Angiotensin II (Ang II), a key mediator of hypertensive, causes structural changes in the arteries (vascular remodeling), which involve alterations in cell growth, vascular smooth muscle cell (VSMC) hypertrophy. Ang II promotes fibrotic factor like IGFBP5, which mediates the profibrotic effects of Ang II in the heart and kidneys, lung and so on. The purpose of this study was to identify the signaling pathway of IGFBP5 on cell proliferation and migration of Ang II-stimulated VSMC. We have been interested in Ang II-induced IGFBP5 and were curious to determine whether a Pitavastatin would ameliorate the effects. Herein, we investigated the question of whether Ang II induced the levels of IGFBP5 protein followed by proliferation and migration in VSMC. Pretreatment with the specific Angiotensin receptor type 1 (AT1) inhibitor (Losartan), Angiotensin receptor type 2 (AT2) inhibitor (PD123319), MAPK inhibitor (U0126), ERK1/2 inhibitor (PD98059), P38 inhibitor (SB600125) and PI3K inhibitor (LY294002) resulted in significantly inhibited IGFBP5 production, proliferation, and migration in Ang II-stimulated VSMC. In addition, IGFBP5 knockdown resulted in modulation of Ang II induced proliferation and migration via IGFBP5 induction. In addition, Pitavastatin modulated Ang II induced proliferation and migration in VSMC. Taken together, our results indicated that Ang II induces IGFBP5 through AT1, ERK1/2, P38, and PI3K signaling pathways, which were inhibited by Pitavastatin. These findings may suggest that Pitavastatin has an effect on vascular disease including hypertension.

Redox regulation of cardiomyocyte cell cycling via an ERK1/2 and c-Myc-dependent activation of cyclin D2 transcription

Adult mammalian cardiomyocytes have a very limited capacity to proliferate, and consequently the loss of cells after cardiac stress promotes heart failure. Recent evidence suggests that administration of hydrogen peroxide (H2O2), can regulate redox-dependent signalling pathway(s) to promote cardiomyocyte proliferation in vitro, but the potential relevance of such a pathway in vivo has not been tested. We have generated a transgenic (Tg) mouse model in which the H2O2-generating enzyme, NADPH oxidase 4 (Nox4), is overexpressed within the postnatal cardiomyocytes, and observed that the hearts of 1-3week old Tg mice pups are larger in comparison to wild type (Wt) littermate controls. We demonstrate that the cardiomyocytes of Tg mouse pups have increased cell cycling capacity in vivo as determined by incorporation of 5-bromo-2'-deoxyuridine. Further, microarray analyses of the transcriptome of these Tg mouse hearts suggested that the expression of cyclin D2 is significantly increased. We investigated the molecular mechanisms which underlie this more proliferative phenotype in isolated neonatal rat cardiomyocytes (NRCs) in vitro, and demonstrate that Nox4 overexpression mediates an H2O2-dependent activation of the ERK1/2 signalling pathway, which in turn phosphorylates and activates the transcription factor c-myc. This results in a significant increase in cyclin D2 expression, which we show to be mediated, at least in part, by cis-acting c-myc binding sites within the proximal cyclin D2 promoter. Overexpression of Nox4 in NRCs results in an increase in their proliferative capacity that is ablated by the silencing of cyclin D2. We further demonstrate activation of the ERK1/2 signalling pathway, increased phosphorylation of c-myc and significantly increased expression of cyclin D2 protein in the Nox4 Tg hearts. We suggest that this pathway acts to maintain the proliferative capacity of cardiomyocytes in Nox4 Tg pups in vivo and so delays their exit from the cell cycle after birth.

Identification of activators of ERK5 transcriptional activity by high-throughput screening and the role of endothelial ERK5 in vasoprotective effects induced by statins and antimalarial agents

Because ERK5 inhibits endothelial inflammation and dysfunction, activating ERK5 might be a novel approach to protecting vascular endothelial cells (ECs) against various pathological conditions of the blood vessel. We have identified small molecules that protect ECs via ERK5 activation and determined their contribution to preventing cardiac allograft rejection. Using high-throughput screening, we identified certain statins and antimalarial agents including chloroquine, hydroxychloroquine, and quinacrine as strong ERK5 activators. Pitavastatin enhanced ERK5 transcriptional activity and Kruppel-like factor-2 expression in cultured human and bovine ECs, but these effects were abolished by the depletion of ERK5. Chloroquine and hydroxychloroquine upregulated ERK5 kinase activity and inhibited VCAM-1 expression in an ERK5-dependent but MAPK/ERK kinase 5- and Kruppel-like factor 2/4-independent manner. Leukocyte rolling and vascular reactivity were used to evaluate endothelial function in vivo, and we found that EC-specific ERK5 knockout (ERK5-EKO) mice exhibited increased leukocyte rolling and impaired vascular reactivity, which could not be corrected by pitavastatin. The role of endothelial ERK5 in acute cardiac allograft rejection was also examined by heterotopic grafting of the heart obtained from either wild-type or ERK5-EKO mice into allomismatched recipient mice. A robust increase in both inflammatory gene expression and CD45-positive cell infiltration into the graft was observed. These tissue rejection responses were inhibited by pitavastatin in wild-type but not ERK5-EKO hearts. Our study has identified statins and antimalarial drugs as strong ERK5 activators and shown that ERK5 activation is preventive of endothelial inflammation and dysfunction and acute allograft rejection.

Statins as anti-inflammatory agents in atherogenesis: molecular mechanisms and lessons from the recent clinical trials

Ample evidence exists in support of the potent anti-inflammatory properties of statins. In cell studies and animal models statins exert beneficial cardiovascular effects. By inhibiting intracellular isoprenoids formation, statins suppress vascular and myocardial inflammation, favorably modulate vascular and myocardial redox state and improve nitric oxide bioavailability. Randomized clinical trials have demonstrated that further to their lipid lowering effects, statins are useful in the primary and secondary prevention of coronary heart disease (CHD) due to their anti-inflammatory potential. The landmark JUPITER trial suggested that in subjects without CHD, suppression of low-grade inflammation by statins improves clinical outcome. However, recent trials have failed to document any clinical benefit with statins in high risk groups, such in heart failure or chronic kidney disease patients. In this review, we aim to summarize the existing evidence on statins as an anti-inflammatory agent in atherogenesis. We describe the molecular mechanisms responsible for the anti-inflammatory effects of statins, as well as clinical data on the non lipid-lowering, anti-inflammatory effects of statins on cardiovascular outcomes. Lastly, the controversy of the recent large randomized clinical trials and the issue of statin withdrawal are also discussed.

Cholesterol-lowering strategies reduce vascular LRP1 overexpression induced by hypercholesterolaemia

BACKGROUND

Low density lipoprotein receptor-related protein (LRP1) plays a key role on vascular functionality and is upregulated by hypercholesterolemia and hypertension. To investigate the effect of cholesterol-lowering interventions on vascular LRP1 over expression and whether simvastatin influences LRP1 expression.

MATERIAL AND METHODS

Male New Zealand rabbits were recruited into various groups, one group was fed a normal chow diet for 28 days (control group, n = 6), other group (n = 24) was fed a hypercholesterolemic diet (HC), six rabbits were euthanized at day 28 to test the capacity of HC diet to induce early atherosclerosis and the rest at day 60 (n = 18) after receiving either HC diet (HC group, n = 6), HC diet with simvastatin (2·5 mg/kg.day) (HC+simv group, n = 6), or a normal chow diet (NC group, n = 6) for the last 32 days.

RESULTS

High-cholesterol diet raised vascular LRP1 concomitantly with increased lipid, VSMC and macrophage content in the arterial intima. Simvastatin and return to normocholesterolemic diet significantly reduced systemic cholesterol levels and vascular lipid content. Interestingly, these interventions also downregulate LRP1 overexpression in the vascular wall although to a different extent (HC+simv: 75 ± 3·6%vs NC: 50 ± 3·5% versus, P = 0·002). Immunohistochemistry studies showed that LRP1 diminushion was associated to a reduction in the number of intimal VSMC in HC+simv.group. Simvastatin per se did not exert any significant effect on LRP1 expression in rabbit aortic smooth muscle cells (rSMC).

CONCLUSIONS

Our results demonstrate that cholesterol-lowering interventions exerted down regulatory effects on vascular LRP1 over expression induced by hypercholesterolemia and that simvastatin did not influence LRP1 expression beyond its cholesterol-lowering effects.

Worsening of hyperglycemia due to atorvastatin in a renal transplant patient

New-onset diabetes mellitus post-renal transplantation [post-transplantation diabetes mellitus (PTDM)] and impaired glucose tolerance are among the most serious adverse metabolic disturbances of kidney transplants. We report a renal transplant patient whose mild post-transplant hyperglycaemia considerably worsened upon substituting atorvastatin for pravastatin. The patient was a 58-years-old Caucasian man who underwent living, non-related kidney transplantation. The mean blood sugar level (BSL) following transplantation was 113.8 mg/dl. In an attempt to reduce LDL cholesterol, atorvastatin 40 mg/day was substituted for pravastatin. Soon after commencement of atorvastatin, polydipsia and polyuria appeared. Both fasting and 2-h post-prandial BSL values increased, while there was no change in the patient's medications, dietary habits and renal function. Upon reverting back to pravastatin, BSL promptly declined to the previously mentioned baseline values. Since PTDM is a strong independent factor of graft failure, cardiovascular events and mortality, physicians should be made aware of this possible adverse effect of atorvastatin on glucose tolerance.

Pitavastatin suppresses mitogen activated protein kinase-mediated Erg-1 induction in human vascular smooth muscle cells

Statins have been demonstrated to elicit a broad range of cellular events resulting in an attenuation of the inflammatory response and enhanced protection to the components of the vessel wall. The present study was designed to examine the effect of pitavastatin on pathways associated with the proinflammatory gene, early growth response (Egr)-1, in human vascular smooth muscle cells. Pretreatment with pitavastatin resulted in a dose-dependent reduction in Egr-1 protein and suppressed Egr-1 mRNA expression in response to phorbol 12-myristate 13-acetate (PMA). A reduction in Egr-1 expression reduced the activation of NGFI-A binding protein (NAB)-2, an Egr-1-dependent gene. Furthermore, these events appeared to be dependent on the ability of pitavastatin to attenuate signaling cascades associated with extracellular regulated kinase (ERK) 1/2, but not p38 and c-Jun N-terminal kinase (JNK).

Pitavastatin improves serum resistin levels in patients with hypercholesterolemia

AIM

Resistin in serum is associated with high risk in patients with atherosclerosis. This clinical study aimed to investigate whether pitavastatin can regulate the serum level of resistin, together with levels of other inflammatory cytokines and adipocytokines.

METHODS

Forty two outpatients (mean age 65.2 +/- 12.6 yr, M/F: 21/21) with hypercholesterolemia were administered 2 mg of pitavastatin and serum levels of resistin, together with serum levels of adiponectin, leptin, TNF-alpha and hsCRP, were measured before, and 12 weeks after enrollment.

RESULTS

There was no significant gender-related difference in initial serum resistin levels. Pitavastatin significantly decreased LDL-cholesterol after 12 weeks. Initial levels of resistin showed a significant correlation with those of hsCRP (r=0.38, p=0.013), but not TNF-alpha or HOMA-R. Serum resistin, but not adiponectin and leptin, levels were significantly decreased, dropping from 17.1 +/- 9.9 ng/ dL to 15.2+/-10.0 (p=0.001) after 12 weeks of administration. The patient group with a baseline hsCRP > or = 0.1 at enrollment (n=17) had decreased levels of both resistin and hsCRP (p=0.011 and p=0.022, respectively).

CONCLUSION

This study showed the pleiotropic effect of pitavastatin on the serum resistin concentration, suggesting that it may assist in the prevention of atherosclerosis.

Preferable effect of pravastatin compared to atorvastatin on beta cell function in Japanese early-state type 2 diabetes with hypercholesterolemia

While a large numbers of clinical trials using various kinds of statins has been reported, a possible preventive effect on new onset of type 2 diabetes mellitus was shown only by the subanalysis of The West of Scotland Coronary Prevention Study (WOSCOPS) using pravastatin. The aim of this study was to investigate whether pravastatin has a preferable effect on glucose tolerance among statins. An open-label prospective cross-over trial was performed to compare the effect of pravastatin (10 mg/day) or atorvastatin (10 mg/day) in Japanese early-state type 2 diabetes mellitus with hypercholesterolemia. The analyzed study subjects were treated with pravastatin (10 mg/day, n = 12) or atorvastatin (10 mg/day, n = 12) for 12 weeks. After a 4-week-washout period, the drugs were switched and treatment was continued for another 12 weeks. Oral glucose tolerance test (OGTT) was performed to evaluate several parameters including the appropriateness of beta cell function for the individual insulin sensitivity (disposition index: product of a validated secretion parameter and sensitivity) at the end of each therapy. HbA(1c) and 2 h-glucose levels during OGTT in the pravastatin treatment were significantly lower than atorvastatin treatment. Disposition index after pravastatin treatment was significantly higher than after atorvastatin treatment. In conclusion, our study suggests that pravastatin has a favorable effect on pancreatic beta cell function compared with atorvastatin.

Pitavastatin suppresses acute and chronic rejection in murine cardiac allografts

INTRODUCTION

HMG-CoA reductase inhibitors play several roles in the maintenance of organ transplants. We investigated the role of pitavastatin, a potent and newly developed HMG-CoA reductase inhibitor, in cardiac allograft rejection and mechanism of graft arterial disease (GAD) suppression.

METHODS

Balb/c mice hearts were transplanted into C3H/He mice (a full allomismatch combination) to assess acute rejection or C57BL/6 hearts into B6.C-H2(<bm12>)KhEg (a class II mismatch combination) to examine the extent of GAD. Pitavastatin was administered orally to mice everyday (3 mg/kg/day). To assess the effect in acute rejection, mixed lymphocyte reaction was performed and cytokine mRNA expression was examined with ribonuclease protection assay.

RESULTS

Pitavastatin significantly prolonged allograft survival. Lymphocyte proliferation was inhibited by pitavastatin, and RPA showed down-regulation of interleukin-6 in pitavastatin-treated cardiac allografts. Allografts in the pitavastatin-treated group after 8 weeks showed less GAD compared with the control group. In vitro, pitavastatin suppressed the smooth muscle cell proliferation in response to activated T cells and inhibited extracellular signal-regulated kinase 1/2 activation.

CONCLUSION

Pitavastatin could be effective in the suppression of acute rejection and GAD development in cardiac transplantation.

Simvastatin reduces insulin-like growth factor-1 signaling in differentiating C2C12 mouse myoblast cells in an HMG-CoA reductase inhibition-independent manner

Inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase occasionally cause myopathy characterized by weakness, pain, and elevated serum creatine phosphokinase (CK). In this study, we investigated the effects of simvastatin, an HMG-CoA reductase inhibitor, on the viability and insulin-like growth factor-1 (IGF-1) signaling in differentiating C2C12 mouse myoblast cells. Simvastatin decreased cell viability and CK activity, a marker of myogenesis, in differentiating cells in a dose-dependent manner. Although the simvastatin-induced decrease in viability in proliferating and differentiated cells was completely abolished by mevalonate or geranylgeranyl-pyrophosphate, the inhibitory effects of simvastatin in differentiating cells were not abolished by mevalonate or isoprenoid derivatives of mevalonate. Moreover, the sensitivity of differentiating cells to simvastatin regarding cell viability was about 7 times higher than that of proliferating cells. After induction of differentiation in the presence of 1 microM simvastatin for 2 days, IGF-1-induced activation of ERK1/2 and Akt was significantly decreased. Although mRNA expression of the IGF-1 receptor beta-chain (IGF-1R beta) did not change, protein level of the 200 kDa IGF-1Rbeta precursor was significantly increased by simvastatin in a dose-dependent manner. Mevalonate did not abolish the effect of simvastatin on IGF-1Rbeta expression. These results suggest that simvastatin decreases IGF-1 signaling via a regulation of the post-translational modification of IGF-1Rbeta in an HMG-CoA reductase inhibition-independent manner.

Immunomodulatory effects of statins and autoimmune rheumatic diseases: novel intracellular mechanism involved

Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, known as statins, are the most commonly prescribed agents for the treatment of hypercholesterolemia. However, the effects of statins may extend beyond their influences on serum cholesterol levels resulting in cholesterol-independent or pleiotropic effects. Clinical, animal and in vitro studies suggest that statins have additional clinical uses because of their anti-inflammatory and immunomodulatory effects, in part due to their capacity to interfere with the mevalonate pathway and inhibit prenylation of Rho family GTPases. This review focuses on the molecular mechanisms of the anti-inflammatory and immunomodulatory effects of statins. In base to all these information, we suggest that statins could have similar inhibitory effects on MAPKs pathways in cells from RA patients, including osteoclasts and fibroblasts.

Vascular Access Outcomes and Medication Use: A USRDS Study

Several medications have been proposed to improve hemodialysis (HD) vascular access outcomes based on potentially favorable anticoagulant, antiplatelet, or pleiotropic properties. The purpose of this study was to evaluate the relationship between medication use and vascular access patency in a group of HD patients. We conducted a historical cohort study of the US Renal Data System Dialysis Mortality and Morbidity Wave II study to identify patients with an arteriovenous fistula (AVF), polytetrafluoroethylene (PTFE) graft, or a permanent catheter for vascular access. Cox regression analysis, adjusted for age, gender, race, history of coronary artery disease, peripheral vascular disease, or coronary artery bypass graft, was used to model the hazard ratio (HR) of permanent vascular access failure. Of the 2001 HD patients in the Wave II study, 901 (45%) were included in the analysis. PTFE graft patency was greater for males (HR, 0.73; 95% CI 0.53-1.00, p = 0.05) and for older individuals (HR, 0.99; 95% CI 0.98-1.00, p = 0.02). Treatment with antiplatelet medications, ticlopidine and dipyridamole (HR, 3.54; 95% CI 1.07-11.76; p = 0.04), or aspirin (HR, 2.49; 95% CI 1.31-4.73; p = 0.005) was associated with significantly worse AVF patency. Antiplatelet agents had a significant negative association with access patency in this cohort. In contrast to other published data, it was difficult to identify any beneficial effect of specific medications on access patency.

The effect of fluvastatin on plasma adiponectin levels in dyslipidaemia

OBJECTIVE

There is controversy about the effects of statins on insulin resistance and plasma adiponectin. The aim of this study was to investigate the effects of fluvastatin treatment on these parameters in a group of dyslipidaemic patients who had no confounding factors for insulin resistance or alterations in plasma adiponectin.

DESIGN AND PATIENTS

Forty-nine patients [27 males, 22 females; mean age 47.2 +/- 10.3 years; body mass index (BMI) 29.64 +/- 3.2 kg/m2] with dyslipidaemia and 20 controls (six males, 14 females; mean age 45.3 +/- 9.31 years; BMI 30.07 +/- 4.04 kg/m2) were enrolled. All patients were treated initially with therapeutic lifestyle changes (TLC) for 6 weeks. Six out of 49 subjects were excluded from the study. Then, 24 out of 43 patients with high blood cholesterol despite TLC were allocated to fluvastatin 80 mg daily plus TLC, and the remaining 19 patients with normal cholesterol were subjected to TLC alone for additional 12 weeks.

MEASUREMENTS

Plasma adiponectin, immunoreactive insulin levels, BMI, waist circumference, blood pressure, lipids, and glucose were determined. The insulin sensitivity index was quantified using the homeostasis model assessment (HOMA).

RESULTS

TLC caused significant improvement in plasma insulin (P = 0.02) and elevation in plasma adiponectin (P = 0.02). Fluvastatin treatment decreased total cholesterol and low density lipoprotein (LDL)-cholesterol significantly (P = 0.01 and P = 0.02, respectively). No significant effect of fluvastatin was observed on plasma insulin or adiponectin or on the HOMA index.

CONCLUSIONS

Fluvastatin does not improve plasma adiponectin levels and insulin sensitivity, despite its beneficial effects on lipid levels. Our data, however, were limited by the fact that a more accurate method of assessing insulin sensitivity, the euglycaemic-hyperinsulinaemic glucose clamp technique, was not used.

Acute onset and worsening of diabetes concurrent with administration of statins

We report a patient in whom the administration of HMG CoA reductase inhibitors (statins) might have triggered the onset and worsening of diabetes. The patient was a 48-year-old Japanese man who underwent annual medical examination but had never been told of hyperglycemia. Four months after the commencement of atorvastatin (10 mg/day) treatment, a diagnosis of diabetes mellitus was made from his typical symptoms of hyperglycemia, postprandial plasma glucose level of 29.8 mmol/l and HbA1c of 11.5%. After 2 months of insulin therapy and 3 months after the cessation of atorvastatin, almost complete resolution of diabetes was observed. During the subsequent 3 months, diet therapy alone was sufficient to control blood glucose level. Then, we prescribed pravastatin (20 mg/day). During the subsequent 3 months, HbA1c was gradually increased. However, after discontinuation of pravastatin, HbA1c was gradually decreased. In the general population, statin does not seem to have critical adverse effects on glucose tolerance, but it may uncommonly modify the natural course of the development of diabetes in certain patients.

Anti-oxidative effect of fluvastatin in hyperlipidemic type 2 diabetic patients

An open-label prospective cross-over trial was performed to evaluate the antioxidative effect of fluvastatin in Japanese type 2 diabetics with hyperlipidemia. The study subjects were 10 patients who were on pravastatin (10 mg/day) or simvastatin (5 mg/day). After at least 12 weeks of continuous pravastatin or simvastatin therapy, the drugs were washed out for 12 weeks and replaced with fluvastatin (30 mg/day), then the treatment was continued for another 12 weeks. Total cholesterol and LDL cholesterol were efficiently and comparably reduced by all three statin agents. There were no differences in serum parameters of oxidative stress such as malondialdehyde-modified low-density lipoprotein, thiobarbituric acid-reactive substances, and 8-iso-prostaglandin F2alpha between pravastatin/simvastatin and fluvastatin. However, fluvastatin, but not pravastatin/simvastatin, significantly reduced 3,5,7-cholestatriene in erythrocyte membrane, representing the extent of membrane cholesterol peroxidation. Our data demonstrated that fluvastatin has a unique anti-oxidative effect in patients with type 2 diabetes and hyperlipidemia, compared with other statins.

Simvastatin inhibits MMP‐9 secretion from human saphenous vein smooth muscle cells by inhibiting the RhoA/ROCK pathway and reducing MMP‐9 mRNA levels

Increased matrix metalloproteinase-9 (MMP-9) expression is associated with intimal hyperplasia in saphenous vein (SV) bypass grafts. Recent evidence suggests that HMG-CoA reductase inhibitors (statins) can prevent the progression of vein graft failure. Here we investigated whether statins inhibited MMP-9 secretion from cultured human SV smooth muscle cells (SMC) and examined the underlying mechanisms. SV-SMC from different patients were exposed to phorbol ester (TPA) or PDGF-BB plus interleukin-1alpha (IL-1). MMP-9 secretion and mRNA expression were analyzed using gelatin zymography and RT-PCR, respectively. Specific signal transduction pathways were investigated by immunoblotting and pharmacological inhibition. Simvastatin reduced TPA- and PDGF/IL-1-induced MMP-9 secretion and mRNA levels, effects reversed by geranylgeranyl pyrophosphate and mimicked by inhibiting Rho geranylgeranylation or Rho-kinase (ROCK). MMP-9 secretion induced by PDGF/IL-1 was mediated via the ERK, p38 MAPK, and NFkappaB pathways, whereas that induced by TPA was mediated specifically via the ERK pathway. Simvastatin failed to inhibit activation of these signaling pathways. Moreover, simvastatin did not affect MMP-9 mRNA stability. Together these data suggest that simvastatin reduces MMP-9 secretion from human SV-SMC by inhibiting the RhoA/ROCK pathway and decreasing MMP-9 mRNA levels independently of effects on signaling pathways required for MMP-9 gene expression.

Pitavastatin: efficacy and safety profiles of a novel synthetic HMG-CoA reductase inhibitor

The use of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, statins, has been shown to reduce major cardiovascular events in both primary and secondary prevention, and statins became one of the most widely prescribed classes of drugs throughout the world. Previously, statins have been well tolerated and have shown favorable safety profiles. However, the voluntary withdrawal of cerivastatin from the market because of a disproportionate number of reports of rhabdomyolysis-associated deaths drew attention to the pharmacokinetic profile of statins, which may possibly have been related to serious drug-drug interactions. Pitavastatin (NK-104, previously called itavastatin or nisvastatin, Kowa Company Ltd., Tokyo) is a novel, fully synthetic statin, which has a potent cholesterol-lowering action. The short-term and long-term lipid-modifying effects of pitavastatin have already been investigated in subjects with primary hypercholesterolemia, heterozygous familial hypercholesterolemia, hypertriglyceridemia, and type-2 diabetes mellitus accompanied by hyperlipidemia. Within the range of daily doses from 1 to 4 mg, the efficacy of pitavastatin as a lipid-lowering drug seems to be similar, or potentially superior, to that of atorvastatin. According to the results of pharmacokinetic studies, pitavastatin showed favorable and promising safety profile; it was only slightly metabolized by the cytochrome P450 (CYP) system, its lactone form had no inhibitory effects on the CYP3A4-mediated metabolism of concomitantly administered drugs; P-glycoprotein-mediated transport did not play a major role in its disposition, and pitavastatin did not inhibit P-glycoprotein activity. It could be concluded that pitavastatin could provide a new and potentially better therapeutic choice for lipid-modifying therapy than do the currently available statins. The efficacy and safety of higher dose treatment, as well as its long-term effects in the prevention of coronary artery disease, should be further investigated.

Effects of Fluvastatin in Type 2 Diabetic Patients with Hyperlipidemia: Reduction in Cholesterol Oxidation Products and VCAM-1

The purpose of this study was to investigate the lipid-lowering and anti-oxidative effects of fluvastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor, in type 2 diabetic patients. Six patients (3 men and 3 women, mean age = 56.2) took 20 mg of fluvastatin once daily (at night) for 12 weeks. Several markers of oxidative stress were then measured in these patients including plasma cholesterol oxidation products, i.e. oxysterols, and the levels of circulating adhesion molecules. Plasma total cholesterol levels were reduced by 12.3% in these individuals after 4 weeks of treatment, with levels remaining below 220 mg/dl for the entire treatment period. LDL levels were significantly reduced at 4 (18.1%) and 12 weeks (16.1%), and triglyceride levels were significantly reduced after 8 (22.5%) and 12 (37.7%) weeks of treatment. HDL-C levels increased from 50.7 +/- 15.4 prior to treatment to 63.8 +/- 24.3 mg/dl after 12 weeks of treatment, though this increase was not statistically significant. Lipid hydroperoxide, thiobarbituric acid-reactive substance (TBARS), and oxysterol levels were also reduced, suggesting that fluvastatin also had anti-oxidative effects. Finally, VCAM-1 levels were similarly reduced by fluvastatin treatment. We conclude that fluvastatin safely improves the plasma lipid profile in type 2 diabetic patients with hyperlipidemia. We speculate that this drug might be doubly effective in reducing atherosclerosis and cardiac events in these patients as a result of its demonstrated anti-oxidative effects and its ability to reduce VCAM-1 levels.