The effects of HMG-CoA reductase inhibitors on endothelial function

Randall's plaque and calcium oxalate stone formation: role for immunity and inflammation

Idiopathic calcium oxalate (CaOx) stones often develop attached to Randall's plaque present on kidney papillary surfaces. Similar to the plaques formed during vascular calcification, Randall's plaques consist of calcium phosphate crystals mixed with an organic matrix that is rich in proteins, such as inter-α-trypsin inhibitor, as well as lipids, and includes membrane-bound vesicles or exosomes, collagen fibres and other components of the extracellular matrix. Kidney tissue surrounding Randall's plaques is associated with the presence of classically activated, pro-inflammatory macrophages (also termed M1) and downregulation of alternatively activated, anti-inflammatory macrophages (also termed M2). In animal models, crystal deposition in the kidneys has been associated with the production of reactive oxygen species, inflammasome activation and increased expression of molecules implicated in the inflammatory cascade, including osteopontin, matrix Gla protein and fetuin A (also known as α2-HS-glycoprotein). Many of these molecules, including osteopontin and matrix Gla protein, are well known inhibitors of vascular calcification. We propose that conditions of urine supersaturation promote kidney damage by inducing the production of reactive oxygen species and oxidative stress, and that the ensuing inflammatory immune response promotes Randall's plaque initiation and calcium stone formation.

Beneficial Effect of Statin Therapy on Arterial Stiffness

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

Endothelial function improvement in patients with familial hypercholesterolemia receiving PCSK-9 inhibitors on top of maximally tolerated lipid lowering therapy

BACKGROUND

Treatment with protein convertase subtilisin kexin type 9 inhibitors (PCSK-9i) reduced cholesterol levels and cardiovascular events in patients with hypercholesterolemia. We assessed changes in lipid profile, oxidation markers and endothelial function in patients with familial hypercholesterolemia (FH) after a 12-week treatment with a PCSK-9i.

METHODS

Patients with FH starting a treatment with PCSK-9i were included. Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), lipoprotein(a) (Lp(a)), small dense LDL (assessed by LDL score), 11-dehydro-thromboxane (11-TXB2), 8-isoprostaglandin-2alpha (8-iso-PGF2α), flow-mediated dilation (FMD) and reactive hyperaemia index (RHI) were evaluated before starting PCSK-9i treatment and after a 12-week treatment.

RESULTS

Twenty-five subjects were enrolled (52% males, mean age 51.5 years). At the 12-week assessment, we observed a 38% median reduction in TC, 52% in LDL-C, 7% in Lp(a) and 46% in LDL score. In parallel, 11-TXB2 and 8-iso-PGF2α showed a reduction of 18% and 17%, respectively. FMD changed from 4.78% ± 2.27 at baseline to 10.6% ± 5.89 at 12 weeks (p < 0.001), with RHI changing from 2.37 ± 1.23 to 3.76 ± 1.36 (p < 0.001). A multivariate analysis showed that, after adjusting for potential confounders, change in LDL score was an independent predictor of changes in FMD (β = -0.846, p = 0.015) and in 8-iso-PGF2α (β = 0.778, p = 0.012).

CONCLUSIONS

Small dense LDL reduction (assessed by LDL score) is related to changes in oxidation markers and endothelial function in patients with FH treated with PCSK-9i.

Animal Models of Preeclampsia: Causes, Consequences, and Interventions

Preeclampsia is a common pregnancy complication, affecting 2% to 8% of pregnancies worldwide, and is an important cause of both maternal and fetal morbidity and mortality. Importantly, although aspirin and calcium are able to prevent preeclampsia in some women, there is no cure apart from delivery of the placenta and fetus, often necessitating iatrogenic preterm birth. Preclinical models of preeclampsia are widely used to investigate the causes and consequences of preeclampsia and to evaluate safety and efficacy of potential preventative and therapeutic interventions. In this review, we provide a summary of the published preclinical models of preeclampsia that meet human diagnostic criteria, including the development of maternal hypertension, together with new-onset proteinuria, maternal organ dysfunction, and uteroplacental dysfunction. We then discuss evidence from preclinical models for multiple causal factors of preeclampsia, including those implicated in early-onset and late-onset preeclampsia. Next, we discuss the impact of exposure to a preeclampsia-like environment for later maternal and progeny health. The presence of long-term impairment, particularly cardiovascular outcomes, in mothers and progeny after an experimentally induced preeclampsia-like pregnancy, implies that later onset or reduced severity of preeclampsia will improve later maternal and progeny health. Finally, we summarize published intervention studies in preclinical models and identify gaps in knowledge that we consider should be targets for future research.

Improved endothelial function after short-term therapy with evolocumab

BACKGROUND

The reduction of cholesterol levels with cholesterol-lowering therapy may improve endothelial function. Lipid-lowering therapy has been greatly enhanced by the introduction of proprotein convertase subtilisin/kexin type 9 (PCSK9) antibodies. Less is known of the effect of PCSK9 inhibitors on endothelial function of subjects with hypercholesterolemia.

OBJECTIVE

To assess whether treatment with PCSK9 inhibitors may improve endothelial function evaluated by brachial artery vasoreactivity test.

METHODS

Brachial artery vasoreactivity test was performed in 14 consecutive patients with previous myocardial infarction before and after 2 months of therapy with evolocumab 140 mg twice in a month. Mean brachial artery diameter, velocity time integral, flow-mediated dilation (FMD) and low-density lipoprotein (LDL) cholesterol levels were also evaluated.

RESULTS

After 2 months of treatment with evolocumab, mean total cholesterol levels decreased from 245 ± 41 to 128 ± 30 mg/dL (P < .001, -48%), and LDL levels from 176 ± 43 to 71 ± 26 mg/dL (P = .001, -59%); FMD conversely increased from 6.3 ± 4.1% to 8.8 ± 6.3% (P = .004, +40%). Improvement in FMD was proportional to reduction of LDL levels (r = 0.69, P = .006). Therapy with evolocumab increased brachial artery diameter during vasoreactivity test (peak values 0.39 ± 0.09 vs 0.36 ± 0.11 cm, P = .010; final values 0.36 ± 0.10 vs 0.34 ± 0.10 cm, P = .001), and velocity time integral (peak levels 96 ± 1 vs 85 ± 9 cm, P = .045).

CONCLUSIONS

Two months of treatment with evolocumab 140 mg may improve endothelial function in subjects with increased cardiovascular risk. The improvement in endothelial function is proportional to LDL reduction.

Rho-kinase: regulation, (dys)function, and inhibition

In a variety of normal and pathological cell types, Rho-kinases I and II (ROCKI/II) play a pivotal role in the organization of the nonmuscle and smooth muscle cytoskeleton and adhesion plaques as well as in the regulation of transcription factors. Thus, ROCKI/II activity regulates cellular contraction, motility, morphology, polarity, cell division, and gene expression. Emerging evidence suggests that dysregulation of the Rho-ROCK pathways at different stages is linked to cardiovascular, metabolic, and neurodegenerative diseases as well as cancer. This review focuses on the current status of understanding the multiple functions of Rho-ROCK signaling pathways and various modes of regulation of Rho-ROCK activity, thereby orchestrating a concerted functional response.

Low-Dose Fluvastatin Prevents the Functional Alterations of Endothelium Induced by Short-Term Cholesterol Feeding in Rabbit Carotid Artery

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, commonly known as statins, are the medical treatment of choice for hypercholesterolemia. In addition to lowering serum-cholesterol levels, statins appear to promote pleiotropic effects that are independent of changes in serum cholesterol. In this study, we investigated the effects of low-dose fluvastatin on antioxidant enzyme activities (superoxide dismutase, SOD; catalase), total nitrite/nitrate levels, and vascular reactivity in 2% cholesterol-fed rabbits. This diet did not generate any fatty streak lesions on carotid artery wall. However, SOD activity significantly increased with cholesterol feeding whereas the catalase activities decreased. The levels of nitrite/nitrate, stable products of NO degradation, diminished. Moreover, dietary cholesterol reduced vascular responses to acetylcholine, but contractions to serotonin were augmented. Fluvastatin treatment abrogated the cholesterol-induced increase in SOD, increased the levels of nitric oxide metabolites in tissue, and restored both the impaired vascular responses to acetylcholine and the augmented contractile responses to serotonin without affecting plasma-cholesterol levels. Phenylephrine contractions and nitroglycerine vasodilatations did not change in all groups. This study indicated that fluvastatin treatment performed early enough to improve impaired vascular responses may delay cardiovascular complications associated with several cardiovascular diseases.

Hypotensive effect of atorvastatin is not related to changes in inflammation and oxidative stress

We sought to determine if atorvastatin lowers blood pressure in patients with previously diagnosed and well-controlled essential arterial hypertension and if this effect could be related to anti-inflammatory and anti-oxidative effects. Among 92 patients with essential arterial hypertension, we studied 56 non-smoking and normolipemic: 39 were randomized to receive 80 mg atorvastatin daily for 3 months (statin-treated patients, ST), and the rest continued a previous hypotensive therapy (statin-free patients, SF). Blood pressure was measured using a 24-h ambulatory blood pressure measurement device. Serum levels of high-sensitivity C-reactive protein (hs-CRP), total antioxidant status (TAS) and plasma peroxides (assessed by Oxystat) were measured in both groups. The mean change in systolic BP (SBP) for atorvastatin was -5.7 mmHg (95% confidence interval CI, -4.1 to -7.2 mmHg), and the mean change in diastolic BP (DBP) was -3.9 mmHg (95% CI, -2.7 to -5.0 mmHg). No change in BP in SF patients was observed. In the ST group, hs-CRP and peroxides did not significantly decrease. In the SF group, concentrations of hs-CRP proceeded to decrease while peroxides increased. In the ST group, changes in hs-CRP correlated with changes in total cholesterol and low-density lipoprotein cholesterol (r = 0.41, p = 0.013 and r = 0.35, p = 0.04, respectively) but did not correlate with changes in BP. The hypotensive statin effect was independent of the hypolipemic effect. During three months of observation, TAS concentrations in both groups remained stable. In this randomized study, additionally administered atorvastatin to non-smoking and normolipemic patients with well-controlled essential arterial hypertension resulted in reduction of BP. This effect was not followed by significant changes in hs-CRP, TAS or Oxystat concentrations. The hypotensive effect of atorvastatin did not depend on anti-inflammatory, anti-oxidative or hypolipemic actions.

Association of ex vivo vascular and bronchial dysfunctions in smokers

BACKGROUND

It has recently been shown that systemic endothelial dysfunction is associated with airflow limitation in COPD. We conducted this ex vivo study to assess whether endothelial dysfunction of pulmonary arteries of former smokers was associated with modifications of airway functions.

METHODS

Pharmacological experiments were conducted on arterial and bronchial rings obtained from lung specimen of 20 patients: 13 smokers without COPD and 7 smokers with mild to moderate COPD (GOLD class I or II). The impairment of acetylcholine-mediated vasodilation (constriction) of preconstricted arterial rings defined endothelial dysfunction. Resting tone (initial and after a contraction test) and cGMP-mediated dilation of bronchial rings in response to zaprinast were evaluated.

RESULTS

Initial airway resting tone was correlated with airflow limitation (FEV(1) % predicted: Rho = -0.49; p = 0.032). The acetylcholine response of arterial rings was correlated with zaprinast-induced bronchodilation (Rho = 0.54, p = 0.019). Patients with endothelial dysfunction (n = 5), as compared with those displaying no dysfunction (n = 15), were characterized by an increased resting tone (after contraction test), an impaired response to zaprinast but a similar degree of airflow limitation (FEV(1)).

CONCLUSION

Endothelial dysfunction of pulmonary arteries is associated with increased resting tone and impaired cGMP-mediated dilation of airways in former smokers, suggesting common underlying mechanisms of pulmonary arterial and bronchial dysfunctions.

Atorvastatin neutralises the thrombin-induced tissue factor expresion in endothelial cells via geranylgeranyl pyrophosphate

Statins may have beneficial effects in atherogenesis given their antithrombotic properties involving non-lipid mechanisms that modify endothelial function of tissue factor induction by thrombin. In this study, we investigate the effect of atorvastatin on tissue factor (TF) activity in thrombin-stimulated endothelial cells and its regulation through mevalonate or its derivatives. First subculture of human umbilical endothelial cells was used for this study. Cells were treated with thrombin and atorvastatin for different time intervals and dosage. Tissue factor activity was measured as Factor Xa generation induced by Tissue Factor-Factor VIIa complex on confluent cells. Our results show that atorvastatin prevents the thrombin-induced up-regulation of tissue factor activity in a concentration-dependent manner. Mevalonate and geranylgeranyl pyrophosphate reversed this inhibitory effect of atorvastatin on tissue factor activity, while the presence of farnesyl pyrophosphate did not prevent the atorvastatin effect on thrombin-induced tissue factor activity. Rho-kinase inhibitor did not affect the thrombin stimulation of tissue factor activity. High amount of hydrophobic isoprenoid groups decreases the thrombin-induced TF activity and may promote endothelial cell anti-thrombotic action. Rho kinase pathways do not have a major role in the thrombin-mediated TF activity. The inhibitory effect of atorvastatin on thrombin-induced TF activity was partially reversed by MVA and GGPP but not FPP.

Basic Science Review: Statin Therapy-Part I: The Pleiotropic Effects of Statins in Cardiovascular Disease

3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG CoA-reductase) inhibitors, otherwise known as statins, are currently the medical treatment of choice for hypercholesterolemia. Hypercholesterolemia is a known risk factor for cardiovascular disease, and statin therapy has led to a significant reduction in morbidity and mortality from adverse cardiac events, stroke, and peripheral arterial disease. In addition to achieving a therapeutic decrease in serum cholesterol levels, statin therapy appears to promote other effects that are independent of changes in serum cholesterol. These ‘‘pleiotropic’’ effects include attenuation of vascular inflammation, improved endothelial cell function, stabilization of atherosclerotic plaque, decreased vascular smooth muscle cell migration and proliferation, and inhibition of platelet aggregation. This article is part I of a 2-part review, and it focuses on the pleiotropic effects of statins at the cellular level.

Niacin extended-release/simvastatin

Niacin extended-release (ER)/simvastatin is a once-daily, fixed-dose combination of the HMG-CoA reductase inhibitor simvastatin and an ER formulation of niacin (a B-complex vitamin). In healthy volunteers who were given niacin ER/simvastatin 2000 mg/40 mg, niacin exposure was similar to that with niacin ER 2000 mg, while simvastatin exposure was increased compared to that with simvastatin 40 mg. In patients with elevated non-high-density lipoprotein cholesterol (non-HDL-C) but with low-density lipoprotein cholesterol (LDL-C) at or below the National Cholesterol Education Program (NCEP) goal after a > or = 2-week simvastatin 20 mg/day run-in period (SEACOAST I), 24 weeks of niacin ER/simvastatin 1000 mg/20 mg or 2000 mg/20 mg per day reduced median plasma non-HDL-C levels to a significantly greater extent than simvastatin 20 mg/day. In patients with elevated non-HDL-C and LDL-C at any level after a > or = 2-week simvastatin 40 mg/day run-in period (SEACOAST II), 24 weeks of niacin ER/simvastatin 1000 mg/40 mg or 2000 mg/40 mg per day was noninferior to simvastatin 80 mg/day in reducing median plasma non-HDL-C levels. Compared with simvastatin monotherapy, there was no significant difference in reduction in plasma LDL-C levels with niacin ER/simvastatin in SEACOAST I, and the noninferiority criterion for LDL-C was not met in SEACOAST II. However, plasma HDL-C levels increased more and triglyceride levels were lowered more than with simvastatin monotherapy (SEACOAST I and II). Niacin ER/simvastatin was generally well tolerated, with flushing being the most common adverse reaction.

Effect of atorvastatin on endothelial function and inflammation in long-duration type 1 diabetic patients without coronary heart disease and arterial hypertension

AIM

We evaluated the ability of atorvastatin, an HMG-CoA reductase inhibitor, to affect endothelial function and inflammation in long-duration (>10 years) type 1 diabetes mellitus (T1DM) patients without coronary heart disease (CHD) and arterial hypertension (AH).

METHODS AND RESULTS

We randomized 204 Caucasians with long-duration T1DM into either the atorvastatin 40 mg/day plus hypolipaemic diet group (n = 154) or the placebo plus hypolipaemic diet group (n = 50) for 6 months. Endothelium-dependent flow-mediated (FMD) and endothelium-independent flow-mediated vasodilatation, serum levels of plasminogen activator inhibitor-1 (PAI-1), von Willebrand factor (vWF) and high sensitivity C-reactive protein (hs-CRP) were estimated before and after treatment. After 6 months of therapy, FMD was increased by 44% in the atorvastatin plus diet group compared with the placebo plus diet group. Treatment with atorvastatin led to a significant reduction in levels of PAI-1 and hs-CRP; however, the elevation of vWF level was observed. In the placebo plus diet group, we observed a significant reduction in levels of hs-CRP but not of vWF and PAI-1.

CONCLUSIONS

Atorvastatin improves endothelial function and reduces some proinflammatory and prothrombotic markers of atherosclerosis in T1DM patients without CHD and AH. The surprising effect of atorvastatin on serum vWF levels in T1DM requires further study.

Improvement in endothelium dysfunction in diabetics treated with statins: a randomized comparison of atorvastatin 20 mg versus rosuvastatin 10 mg

AIM

To investigate the effect a 3-month treatment with atorvastatin 20 mg compared with rosuvastatin 10 mg on endothelium dysfunction in subjects with diabetes.

METHODS

A total of 22 consecutive subjects with diabetes who were not receiving statins were enrolled in the study. Endothelium function was assessed before treatment (T0), after 1 month (T1), and after 3 months of treatment (T2) with statins with brachial echo-Doppler test. Patients were randomized to receive atorvastatin 20 mg or rosuvastatin 10 mg. Blood samples were drawn in the meantime in order to evaluate C-reactive protein (CRP) plasmatic concentrations.

RESULTS

A total of 82% of patients enrolled showed endothelium dysfunction (hyperemic reserve <5%). Treatment with statins significantly improved endothelium function in diabetics. Subjects with endothelium dysfunction decreased from 82% (T0) to 44% (T2): mean hyperemic reserve values increased from 2.64% (T0) to 3.23% (T1) and 4% (T2) in patients treated with rosuvastatin (ANOVA P < 0.01), and from 2.74% (T0) to 2.75% (T1) and 4.40% (T2) in those treated with atorvastatin (ANOVA P < 0.01); differences were significant only comparing T2 with T0. Relative increase in endothelium reserve was 51.51% with rosuvastatin versus 60.58% with atorvastatin (P N.S.). Both statins significantly reduced plasmatic levels of CRP (3.18 +/- 2.43 mg/dL [T0] vs. 1.31 +/- 1.67 mg/dL [T2] with rosuvastatin [P < 0.01], 7.53 +/- 7.46 mg/dL [T0] vs. 2.92 +/- 2.06 mg/dL [T2] with atorvastatin [P < 0.01]). Relative reduction of CRP levels was -50.57% with rosuvastatin versus -36.28% with atorvastatin (P N.S.).

CONCLUSION

A 3-month treatment with either atorvastatin 20 mg or rosuvastatin 10 mg is effective in improving endothelium dysfunction in subjects with diabetes.

Atorvastatin neutralizes the up-regulation of thrombospondin-1 induced by thrombin in human umbilical vein endothelial cells

Statins have been reported to affect blood vessel formation. Thrombospondin-1 (TSP-1) is a multifunctional protein that affects vasculature systems such as platelet activation, angiogenesis, and wound healing. This study was designed to investigate the effect of atorvastatin on TSP-1 synthesis in thrombin-stimulated human umbilical vein endothelial cells (HUVECs), and its regulation by mevalonate or its derivatives. The results showed that atorvastatin down-regulated TSP-1 expression in HUVECs. This effect was fully reversed by mevalonate, farnesylpyrophosphate (FPP), and gerarylgeranylpyrophosphate (GGPP). Furthermore, farnesyltransferase and geranylgeranyltransferase inhibitors decreased TSP-1expression. It was also found that thrombin increased TSP-1 expression in HUVECs. Atorvastatin (0.1, 1, and 10 muM) decreased TSP-1 in thrombin-stimulated cells (45%, 66%, and 80%). Mevalonate partially reversed this inhibitory effect of atorvastatin on TSP-1, whereas the presence of FPP and GGPP did not alter TSP-1. Rho-kinase inhibitor neutralized the up-regulation of TSP-1 induced by thrombin. In conclusion, atorvastatin inhibits TSP-1 expression in endothelial cells via the mevalonate pathway. Rho protein activation is necessary for up-regulation of TSP-1 synthesis induced by thrombin. Because FPP and GGPP are essential for the activity of Rho proteins, inhibition of these proteins may constitute the mechanism by which atorvastatin inhibits thrombin up-regulated TSP-1 expression.

Statins may ameliorate pulmonary hypertension via RhoA/Rho-kinase signaling pathway

Statins are the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors that function as potent inhibitors of cholesterol biosynthesis and have been used for many years for the treatment of hypercholesterolemia. However, accumulating experimental and clinical studies have revealed that the health benefits associated with statins treatment, particularly those conferred on the cardiovascular system, were the cholesterol-independent. Because statins inhibit an early step in the cholesterol biosynthetic pathway, they also inhibit the synthesis of isoprenoids such as farnesylpyrophosphate and geranylgeranylpyrophosphate, which are important postranslational lipid attachments for intracellular signaling molecules such as the Rho GTPases. The isoprenylation of Rho is a prerequisite for Rho activation, facilitating its interaction with the plasma membrane, undergoing GDP-GTP exchange and be activated. Inhibition of RhoA geranylgeranylation by statins decreases membrane GTP-bound active RhoA and subsequent Rho-kinase activity. Activated RhoA via its downstream effector Rho-kinase is involved in a wide range of cellular functions, such as cell migration, proliferation and apoptosis. Recently, rising evidences suggested that RhoA/Rho-kinase pathway was essentially involved in various models of pulmonary hypertension and statins effectively ameliorated pulmonary hypertension. Based on this findings, we hypothesis that statins attenuate pulmonary hypertension via RhoA/Rho-kinase signaling pathway in vivo.

Phosphodiesterase type 5 inhibitors: the day after

OBJECTIVE

Review the literature on phosphodiesterase type 5 inhibitors (PDE5-Is), addressing critical issues in their current and future use, assessing unanswered questions, and identifying research needs.

METHODS

A MEDLINE search was conducted on PDE5-Is, with emphasis on clinical trials and experience, for interpretation and analysis of their present and future role.

RESULTS

Although approximately 40 million patients with erectile dysfunction have been treated successfully worldwide with the three available PDE5-Is, inappropriate instructions, lack of follow-up, and lack of patient-centered care models are the main reasons for "non-response," leading to drop-out rates of >50%. Patients with severe neurologic damage, diabetes mellitus, or severe vascular disease may be resistant to PDE5-Is. Preservation of corporal smooth muscle with chronic administration of PDE5-Is has been reported and substantial evidence indicates that these drugs have beneficial effects on endothelium and cardiovascular function; sildenafil has been approved for the treatment of idiopathic pulmonary hypertension. Improvement of lower urinary tract symptoms in men with benign prostatic hyperplasia after PDE5-I administration has been also suggested.

CONCLUSIONS

The data indicate the necessity for (1) exploration of the pharmacologic characteristics of the three PDE5-Is; (2) research on their pharmacologic differences because some actions seems to be drug-specific; (3) development of alternative management strategies, such as chronic, low, everyday doses of PDE5-Is, if the monthly cost is affordable; and (4) clinical trials on use of PDE5-Is to treat other chronic conditions. The door for innovative therapeutic approaches will open, specifically for cross-risk factor treatment with PDE5-Is or their use in combination treatments or new multimodal pills that take advantage of drugs that exert pleiotropic vascular actions.