Cholesteryl ester transfer protein inhibition as a strategy to reduce cardiovascular risk

Phenolic Compounds from Cherries and Berries for Chronic Disease Management and Cardiovascular Risk Reduction

Cardiovascular diseases (CVDs) are a leading cause of mortality worldwide. Therefore, there is increasing interest in dietary interventions to reduce risk factors associated with these conditions. Cherries and berries are rich sources of bioactive compounds and have attracted attention for their potential cardiovascular benefits. This review summarises the current research on the effects of cherry and berry consumption on cardiovascular health, including in vivo studies and clinical trials. These red fruits are rich in phenolic compounds, such as anthocyanins and flavonoids, which have multiple bioactive properties. These properties include antioxidant, anti-inflammatory, and vasodilatory effects. Studies suggest that regular consumption of these fruits may reduce inflammation and oxidative stress, leading to lower blood pressure, improved lipid profiles, and enhanced endothelial function. However, interpreting findings and establishing optimal dosages is a challenge due to the variability in fruit composition, processing methods, and study design. Despite these limitations, the evidence highlights the potential of cherries and berries as components of preventive strategies against CVD. Further research is needed to maximise their health benefits and improve clinical practice.

Lipoprotein(a) as a Risk Factor for Cardiovascular Diseases: Pathophysiology and Treatment Perspectives

Cardiovascular disease (CVD) is still a leading cause of morbidity and mortality, despite all the progress achieved as regards to both prevention and treatment. Having high levels of lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular disease that operates independently. It can increase the risk of developing cardiovascular disease even when LDL cholesterol (LDL-C) levels are within the recommended range, which is referred to as residual cardiovascular risk. Lp(a) is an LDL-like particle present in human plasma, in which a large plasminogen-like glycoprotein, apolipoprotein(a) [Apo(a)], is covalently bound to Apo B100 via one disulfide bridge. Apo(a) contains one plasminogen-like kringle V structure, a variable number of plasminogen-like kringle IV structures (types 1-10), and one inactive protease region. There is a large inter-individual variation of plasma concentrations of Lp(a), mainly ascribable to genetic variants in the Lp(a) gene: in the general po-pulation, Lp(a) levels can range from <1 mg/dL to >1000 mg/dL. Concentrations also vary between different ethnicities. Lp(a) has been established as one of the risk factors that play an important role in the development of atherosclerotic plaque. Indeed, high concentrations of Lp(a) have been related to a greater risk of ischemic CVD, aortic valve stenosis, and heart failure. The threshold value has been set at 50 mg/dL, but the risk may increase already at levels above 30 mg/dL. Although there is a well-established and strong link between high Lp(a) levels and coronary as well as cerebrovascular disease, the evidence regarding incident peripheral arterial disease and carotid atherosclerosis is not as conclusive. Because lifestyle changes and standard lipid-lowering treatments, such as statins, niacin, and cholesteryl ester transfer protein inhibitors, are not highly effective in reducing Lp(a) levels, there is increased interest in developing new drugs that can address this issue. PCSK9 inhibitors seem to be capable of reducing Lp(a) levels by 25-30%. Mipomersen decreases Lp(a) levels by 25-40%, but its use is burdened with important side effects. At the current time, the most effective and tolerated treatment for patients with a high Lp(a) plasma level is apheresis, while antisense oligonucleotides, small interfering RNAs, and microRNAs, which reduce Lp(a) levels by targeting RNA molecules and regulating gene expression as well as protein production levels, are the most widely explored and promising perspectives. The aim of this review is to provide an update on the current state of the art with regard to Lp(a) pathophysiological mechanisms, focusing on the most effective strategies for lowering Lp(a), including new emerging alternative therapies. The purpose of this manuscript is to improve the management of hyperlipoproteinemia(a) in order to achieve better control of the residual cardiovascular risk, which remains unacceptably high.

Structure-based mechanism and inhibition of cholesteryl ester transfer protein

PURPOSE OF REVIEW

Cholesteryl ester transfer proteins (CETP) regulate plasma cholesterol levels by transferring cholesteryl esters (CEs) among lipoproteins. Lipoprotein cholesterol levels correlate with the risk factors for atherosclerotic cardiovascular disease (ASCVD). This article reviews recent research on CETP structure, lipid transfer mechanism, and its inhibition.

RECENT FINDINGS

Genetic deficiency in CETP is associated with a low plasma level of low-density lipoprotein cholesterol (LDL-C) and a profoundly elevated plasma level of high-density lipoprotein cholesterol (HDL-C), which correlates with a lower risk of atherosclerotic cardiovascular disease (ASCVD). However, a very high concentration of HDL-C also correlates with increased ASCVD mortality. Considering that the elevated CETP activity is a major determinant of the atherogenic dyslipidemia, i.e., pro-atherogenic reductions in HDL and LDL particle size, inhibition of CETP emerged as a promising pharmacological target during the past two decades. CETP inhibitors, including torcetrapib, dalcetrapib, evacetrapib, anacetrapib and obicetrapib, were designed and evaluated in phase III clinical trials for the treatment of ASCVD or dyslipidemia. Although these inhibitors increase in plasma HDL-C levels and/or reduce LDL-C levels, the poor efficacy against ASCVD ended interest in CETP as an anti-ASCVD target. Nevertheless, interest in CETP and the molecular mechanism by which it inhibits CE transfer among lipoproteins persisted. Insights into the structural-based CETP-lipoprotein interactions can unravel CETP inhibition machinery, which can hopefully guide the design of more effective CETP inhibitors that combat ASCVD. Individual-molecule 3D structures of CETP bound to lipoproteins provide a model for understanding the mechanism by which CETP mediates lipid transfer and which in turn, guide the rational design of new anti-ASCVD therapeutics.

The metabolome of Mexican cavefish shows a convergent signature highlighting sugar, antioxidant, and Ageing-Related metabolites

Insights from organisms, which have evolved natural strategies for promoting survivability under extreme environmental pressures, may help guide future research into novel approaches for enhancing human longevity. The cave-adapted Mexican tetra, Astyanax mexicanus, has attracted interest as a model system for metabolic resilience, a term we use to denote the property of maintaining health and longevity under conditions that would be highly deleterious in other organisms (Figure 1). Cave-dwelling populations of Mexican tetra exhibit elevated blood glucose, insulin resistance and hypertrophic visceral adipocytes compared to surface-dwelling counterparts. However, cavefish appear to avoid pathologies typically associated with these conditions, such as accumulation of advanced-glycation-end-products (AGEs) and chronic tissue inflammation. The metabolic strategies underlying the resilience properties of A. mexicanus cavefish, and how they relate to environmental challenges of the cave environment, are poorly understood. Here, we provide an untargeted metabolomics study of long- and short-term fasting in two A. mexicanus cave populations and one surface population. We find that, although the metabolome of cavefish bears many similarities with pathological conditions such as metabolic syndrome, cavefish also exhibit features not commonly associated with a pathological condition, and in some cases considered indicative of an overall robust metabolic condition. These include a reduction in cholesteryl esters and intermediates of protein glycation, and an increase in antioxidants and metabolites associated with hypoxia and longevity. This work suggests that certain metabolic features associated with human pathologies are either not intrinsically harmful, or can be counteracted by reciprocal adaptations. We provide a transparent pipeline for reproducing our analysis and a Shiny app for other researchers to explore and visualize our dataset.

Pleiotropic Effects of PCSK9: Focus on Thrombosis and Haemostasis

The proprotein convertase subtilisin/keying 9 (PCSK9) is a serine protease that has gained importance in recent years as a drug target, mainly due to its effect on cholesterol metabolism in promoting the degradation of the low-density lipoprotein receptor (LDLR). However, this protease may also play an important role in lipid-independent reactions, including the process of thrombogenesis. Considering this, we reviewed the effects and implications of PCSK9 on platelet function and blood coagulation. PCSK9 knockout mice exhibited reduced platelet activity and developed less agonist-induced arterial thrombi compared to the respective control animals. This is in line with known research that elevated blood levels of PCSK9 are associated with an increased platelet reactivity and total number of circulating platelets in humans. Moreover, PCSK9 also has an effect on crucial factors of the coagulation cascade, such as increasing factor VIII plasma levels, since the degradation of this blood clotting factor is promoted by the LDLR. The aforementioned pleiotropic effects of the PCSK9 are important to take into account when evaluating the clinical benefit of PCSK9 inhibitors.

Integrated omics analysis revealed the Tinospora cordifolia intervention modulated multiple signaling pathways in hypertriglyceridemia patients-a pilot clinical trial

Purpose

Hypertriglyceridemia (HTG) is strongly associated with the various types of disease conditions and evolving as epidemics. Hence, it is important to identify molecules that lower the triglyceride and chylomicron levels. Tinospora cordifolia is an illustrious Ayurveda drug, has proved juvenile and immunomodulatory properties.

Methods

Twenty four (24) patients having >499 mg/dL TG and 130-230 mg/dL of cholesterol were randomized and given 100 mL/day (~3.0 g) water extract of T. cordifolia (TCE) for 14 days. Basal parameters were analyzed before and after TC intervention to analyzed primary outcomes. Further, unbiased metabolomics and proteomics profiling was explored to assess the efficacy of TCE in HTG patients.

Results

TCE intervention decreased the levels of triglycerides, and VLDL to 380.45 ± 17.44, and 31.85 ± 5.88, and increased the HDL levels to 47.50 ± 9.05 mg/dL significantly (p < 0.05). Metabolomics analysis identified the significant alteration in 69 metabolites and 72 proteins in plasma of HTG patients. TCE intervention reduced the level of isoprostanes, ROS, BCAA, and fatty acid derivatives, significantly. The annotation databases, Metboanalyst predicted Akt and Rap1 signaling, and ECM-receptor interaction is the most affected in HTG patients. TCE intervention normalized these events by increasing the peroxisome biogenesis and modulating Akt and Rap1 signaling pathway.

Conclusion

T. cordifolia intervention suppresses the baseline in HTG patients. Omics analysis showed that TCE intervention modulates the Akt and Rap signaling, and peroxisome biogenesis to control the cellular switches and signaling pathways. Hence, TCE can be used as a supplement or alternate of standard drugs being used in the management of HTG.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-00985-6.

Effects of two water-based exercise programs on body weight and blood lipid parameters in elderly obese males with a sedentary lifestyle

BACKGROUND AND AIMS

The consequences of exercise on atherogenic features are inconsistent. This study was aimed to examine the impacts of two water-based exercise programs (interval vs. continuous) without dietary intervention on body weight and blood lipid parameters, and its potential interactive effects and the activity of cholesteryl ester transfer protein (CETP) in obese older men with a sedentary lifestyle.

METHODS

Sixty-two sedentary older men, who came to consult on weight loss to the Helal Ferdows Sports Complex, Iran, in 2018, volunteered for participation in this quasi-experimental study. Participants derived from a convenience sample were assigned at random into two aquatic exercise programs: Continuous training (CT) with moderate to vigorous-intensity and interval training (IT) with high-intensity. Both programs continued three months, three times a week, for 60-min each time. Comparing groups and times (pre- and post-intervention) was carried out using the Wilcoxon Nonparametric Test. The following assessments were completed pre- and post-intervention: body weight, body mass index (BMI), CETP activity, and blood lipid parameters.

RESULTS

No significant differences were observed when comparing the variables investigated within and between the groups' pre- and post-intervention (P ˃ 0.05), except for body weight and BMI in the CT after the intervention (respectively, 0.6 kg, P = 0.04; 0.4 kg m^-2, P = 0.03).

CONCLUSIONS

Both water-based exercise programs, without interference in nutrition, do not reveal a significant improvement in atherogenic features. The CT program detected modest but significant influences on body weight and BMI of obese older men with a sedentary lifestyle.

Intracoronary monocyte expression pattern and HDL subfractions after non-ST elevation myocardial infarction

AIMS

Coronary artery disease (CAD) is described as a range of clinical conditions including myocardial infarction (MI) and unstable angina. Lipid and apolipoprotein profiles together with the study of cholesterol deposit and efflux serve to identify novel pre and post infarct scenarios for the treatment of these patients. In (non-ST elevation myocardial infarction) NSTEMI patients, we analysed both systemic and intracoronary serum ability to accept cholesterol as well as cholesterol efflux capacity (CEC) of monocytes in terms of expression of genes involved in the reverse cholesterol transport (RCT).

METHODS AND RESULTS

While HDL-C quantity was similar between systemic and coronary arterial blood, in 21 NSTEMI patients we observed a significant reduction of the preβ-HDL fraction and the levels of Apolipoproteins AI, AII, B and E in coronary versus systemic serum. These data are complemented with the observed reduction of CEC. On the contrary, compared to systemic arterial monocytes, in coronary microenvironment of NSTEMI patients after myocardial infarction, the monocytes exhibited a higher mRNA expression of nuclear receptor LXRα and its targets ABCA1 and APOE, which drive cholesterol efflux capacity.

CONCLUSION

In this cross-sectional study we observe that in the immediate post infarction period, there is a spontaneous bona fide ligand-induced activation of the LXR driven cholesterol efflux capacity of intracoronary monocytes to overcome the reduced serum ability to accept cholesterol and to inhibit the post-infarction pro-inflammatory local microenvironment.

The Role of Phospholipid Transfer Protein in the Development of Atherosclerosis

PURPOSE OF REVIEW

Phospholipid transfer protein (PLTP), a member of lipid transfer protein family, is an important protein involved in lipid metabolism in the circulation. This article reviews recent PLTP research progresses, involving lipoprotein metabolism and atherogenesis.

RECENT FINDINGS

PLTP activity influences atherogenic and anti-atherogenic lipoprotein levels. Human serum PLTP activity is a risk factor for human cardiovascular disease and is an independent predictor of all-cause mortality. PLTP deficiency reduces VLDL and LDL levels and attenuates atherosclerosis in mouse models, while PLTP overexpression exerts an opposite effect. Both PLTP deficiency and overexpression result in reduction of HDL which has different size, inflammatory index, and lipid composition. Moreover, although both PLTP deficiency and overexpression reduce cholesterol efflux capacity, but this effect has no impact in macrophage reverse cholesterol transport in mice. Furthermore, PLTP activity is related with metabolic syndrome, thrombosis, and inflammation. PLTP could be target for the treatment of dyslipidemia and atherosclerosis, although some potential off-target effects should be noted.

Brothers in Arms: ABCA1- and ABCG1-Mediated Cholesterol Efflux as Promising Targets in Cardiovascular Disease Treatment

Atherosclerosis is a leading cause of cardiovascular disease worldwide, and hypercholesterolemia is a major risk factor. Preventive treatments mainly focus on the effective reduction of low-density lipoprotein cholesterol, but their therapeutic value is limited by the inability to completely normalize atherosclerotic risk, probably due to the disease complexity and multifactorial pathogenesis. Consequently, high-density lipoprotein cholesterol gained much interest, as it appeared to be cardioprotective due to its major role in reverse cholesterol transport (RCT). RCT facilitates removal of cholesterol from peripheral tissues, including atherosclerotic plaques, and its subsequent hepatic clearance into bile. Therefore, RCT is expected to limit plaque formation and progression. Cellular cholesterol efflux is initiated and propagated by the ATP-binding cassette (ABC) transporters ABCA1 and ABCG1. Their expression and function are expected to be rate-limiting for cholesterol efflux, which makes them interesting targets to stimulate RCT and lower atherosclerotic risk. This systematic review discusses the molecular mechanisms relevant for RCT and ABCA1 and ABCG1 function, followed by a critical overview of potential pharmacological strategies with small molecules to enhance cellular cholesterol efflux and RCT. These strategies include regulation of ABCA1 and ABCG1 expression, degradation, and mRNA stability. Various small molecules have been demonstrated to increase RCT, but the underlying mechanisms are often not completely understood and are rather unspecific, potentially causing adverse effects. Better understanding of these mechanisms could enable the development of safer drugs to increase RCT and provide more insight into its relation with atherosclerotic risk. SIGNIFICANCE STATEMENT: Hypercholesterolemia is an important risk factor of atherosclerosis, which is a leading pathological mechanism underlying cardiovascular disease. Cholesterol is removed from atherosclerotic plaques and subsequently cleared by the liver into bile. This transport is mediated by high-density lipoprotein particles, to which cholesterol is transferred via ATP-binding cassette transporters ABCA1 and ABCG1. Small-molecule pharmacological strategies stimulating these transporters may provide promising options for cardiovascular disease treatment.

Synthesis, biological evaluation and SAR studies of ursolic acid 3β-ester derivatives as novel CETP inhibitors

Cholesteryl ester transfer protein (CETP) is an attractive therapeutic target for the prevention and treatment of cardiovascular diseases by lowering low-density lipoprotein cholesterol levels as well as raising high-density lipoprotein cholesterol levels in human plasma. Herein, a series of ursolic acid 3β-ester derivatives were designed, synthesized and evaluated for the CETP inhibiting activities. Among these compounds, the most active compound is U12 with an IC50 value of 2.4 μM in enzymatic assay. The docking studies showed that the possible hydrogen bond interactions between the carboxyl groups at both ends of the molecule skeleton and several polar residues (such as Ser191, Cys13 and Ser230) in the active site region of CETP could significantly enhance the inhibition activity. This study provides structural insight of the interactions between these pentacyclic triterpenoid 3β-ester derivatives and CETP protein for the further modification and optimization.

Porcine models for studying complications and organ crosstalk in diabetes mellitus

The worldwide prevalence of diabetes mellitus and obesity is rapidly increasing not only in adults but also in children and adolescents. Diabetes is associated with macrovascular complications increasing the risk for cardiovascular disease and stroke, as well as microvascular complications leading to diabetic nephropathy, retinopathy and neuropathy. Animal models are essential for studying disease mechanisms and for developing and testing diagnostic procedures and therapeutic strategies. Rodent models are most widely used but have limitations in translational research. Porcine models have the potential to bridge the gap between basic studies and clinical trials in human patients. This article provides an overview of concepts for the development of porcine models for diabetes and obesity research, with a focus on genetically engineered models. Diabetes-associated ocular, cardiovascular and renal alterations observed in diabetic pig models are summarized and their similarities with complications in diabetic patients are discussed. Systematic multi-organ biobanking of porcine models of diabetes and obesity and molecular profiling of representative tissue samples on different levels, e.g., on the transcriptome, proteome, or metabolome level, is proposed as a strategy for discovering tissue-specific pathomechanisms and their molecular key drivers using systems biology tools. This is exemplified by a recent study providing multi-omics insights into functional changes of the liver in a transgenic pig model for insulin-deficient diabetes mellitus. Collectively, these approaches will provide a better understanding of organ crosstalk in diabetes mellitus and eventually reveal new molecular targets for the prevention, early diagnosis and treatment of diabetes mellitus and its associated complications.

Comparative quantitative systems pharmacology modeling of anti-PCSK9 therapeutic modalities in hypercholesterolemia

Since the discovery of proprotein convertase subtilisin/kexin type 9 (PCSK9) as an attractive target in the treatment of hypercholesterolemia, multiple anti-PCSK9 therapeutic modalities have been pursued in drug development. The objective of this research is to set the stage for the quantitative benchmarking of two anti-PCSK9 pharmacological modality classes, monoclonal antibodies (mAbs) and small interfering RNA (siRNA). To this end, we developed an integrative mathematical model of lipoprotein homeostasis describing the dynamic interplay between PCSK9, LDL-cholesterol (LDL-C), VLDL-cholesterol, HDL-cholesterol (HDL-C), apoB, lipoprotein a [Lp(a)], and triglycerides (TGs). We demonstrate that LDL-C decreased proportionally to PCSK9 reduction for both mAb and siRNA modalities. At marketed doses, however, treatment with mAbs resulted in an additional ∼20% LDL-C reduction compared with siRNA. We further used the model as an evaluation tool and determined that no quantitative differences were observed in HDL-C, Lp(a), TG, or apoB responses, suggesting that the disruption of PCSK9 synthesis would provide no additional effects on lipoprotein-related biomarkers in the patient segment investigated. Predictive model simulations further indicate that siRNA therapies may reach reductions in LDL-C levels comparable to those achieved with mAbs if the current threshold of 80% PCSK9 inhibition via siRNA could be overcome.

Effect of Food on the Pharmacokinetics of 2 Formulations of DRL-17822, a Novel Selective Cholesteryl Ester Transfer Protein (CETP) Inhibitor, in Healthy Males

DRL-17822 is a novel selective cholesteryl ester transfer protein inhibitor that showed an increased exposure, including an increase of >20-fold of maximum concentration and area under the plasma concentration-time curve from time zero to the time of the last quantifiable concentration, following a high-fat breakfast using a nanocrystal formulation. To reduce this effect of food, we generated an amorphous solid dispersion formulation. In this study, we compared the food effect of both formulations of DRL-17822 in a 2-part randomized, open-label, 4-way crossover study involving healthy adult males 18-45 years of age. In both parts of the study, 12 subjects received both formulations of DRL-17822 in both the fasted and fed states; a low-fat breakfast was provided in the first part and a high-fat breakfast in the second part. Compared to the nanocrystal formulation, the amorphous solid dispersion formulation substantially increased DRL-17822 exposure in the fasted state, including increased maximum concentration, area under the plasma concentration-time curve from time zero to the time of the last quantifiable concentration, and area under plasma concentration-time curve from time zero to infinity. Following a high-fat breakfast, DRL-17822 exposure was increased to a lesser extent in the amorphous solid dispersion formulation compared to the nanocrystal formulation (P < .001). Moreover, compared to the nanocrystal formulation the amorphous solid dispersion formulation caused a more pronounced increase in high-density lipoprotein in the fasted state. Consuming breakfast increased the effect of DRL-17822 on high-density lipoprotein. Taken together, our results indicate that by improving its formulation, DRL-17822 has a favorable exposure profile and therefore a more predictable food effect profile.

Lipid trafficking in cardiovascular disease

The reduction of plasma apolipoprotein B (apoB) containing lipoproteins has long been pursued as the main modifiable risk factor for the development of cardiovascular disease (CVD). This has led to an intense search for strategies aiming at reducing plasma apoB-lipoproteins, culminating in reduction of overall CV risk. Despite 3 decades of progress, CVD remains the leading cause of morbidity and mortality worldwide and, as such, new therapeutic targets are still warranted. Clinical and preclinical research has moved forward from the original concept, under which some lipids must be accumulated and other removed to achieve the ideal condition in disease prevention, into the concept that mechanisms that orchestrate lipid movement between lipoproteins, cells and organelles is equally involved in CVD. As such, this review scrutinizes potentially atherogenic changes in lipid trafficking and assesses the molecular mechanisms behind it. New developments in risk assessment and new targets for the mitigation of residual CVD risk are also addressed.

High-density lipoprotein metabolism and reverse cholesterol transport: strategies for raising HDL cholesterol

A key to effective treatment of cardiovascular disease is to understand the body’s complex lipoprotein transport system. Reverse cholesterol transport (RCT) is the process of cholesterol movement from the extrahepatic tissues back to the liver. Lipoproteins containing apoA-I [high-density lipoprotein (HDL)] are key mediators in RCT, whereas non-high-density lipoproteins (non-HDL, lipoproteins containing apoB) are involved in the lipid delivery pathway. HDL particles are heterogeneous; they differ in proportion of proteins and lipids, size, shape, and charge. HDL heterogeneity is the result of the activity of several factors that assemble and remodel HDL particles in plasma: ATP-binding cassette transporter A1 (ABCA1), lecithin cholesterol acyltransferase (LCAT), cholesteryl ester transfer protein (CETP), hepatic lipase (HL), phospholipid transfer protein (PLTP), endothelial lipase (EL), and scavenger receptor class B type I (SR-BI). The RCT pathway consists of the following steps: 1. Cholesterol efflux from peripheral tissues to plasma, 2. LCAT-mediated esterification of cholesterol and remodeling of HDL particles, 3. direct pathway of HDL cholesterol delivery to the liver, and 4. indirect pathway of HDL cholesterol delivery to the liver via CETP-mediated transfer There are several established strategies for raising HDL cholesterol in humans, such as lifestyle changes; use of drugs including fibrates, statins, and niacin; and new therapeutic approaches. The therapeutic approaches include CETP inhibition, peroxisome proliferator-activated receptor (PPAR) agonists, synthetic farnesoid X receptor agonists, and gene therapy. Results of clinical trials should be awaited before further clinical management of atherosclerotic cardiovascular disease.

Effects of Ginger (Zingiber officinale, Roscoe) Essential Oil on Growth and Laying Performances, Serum Metabolites, and Egg Yolk Antioxidant and Cholesterol Status in Laying Japanese Quail

This study aimed to investigate the effect of ginger (Zingiber officinale, Rosc.) essential oil on growth and laying performances, egg yolk antioxidant and cholesterol status, and serum metabolites in Japanese quail. Eighty 3-week-old Japanese quails weighing between 120 and 130 g were equally and randomly assigned to four groups receiving daily and orally, respectively, 100 µl/kg body weight (bw) distilled water and 50, 100, and 150 µl/kg bw of ginger rhizomes essential oil, respectively. The entire feeding trial for all groups lasted for 9 weeks and the Z. officinale essential oil effects were studied on growth and laying performances, serum metabolites, and egg yolk antioxidant and cholesterol status. Results revealed that feed intake, live and body weights gain, feed conversion ratio, egg production, and weekly mass of eggs were not significantly (P>0.05) influenced by oral administration of ginger rhizomes essential oil. Unlike the abdominal fat weight which decreased significantly (p<0.05) in all treated quails, the oral administration of ginger rhizomes essential oil had no significant effects (p> 0.05) on liver, intestine, heart, and gizzard relative weights as compared to the control. Egg weight markedly (P<0.05) increased in Japanese quails treated with ginger rhizomes essential oil whatever the dose with reference to the control. The serum content in total cholesterol, LDL-cholesterol, and transaminases (AST and ALT) decreased significantly (P<0.05) with 100 and 150 µl/kg bw of ginger rhizomes essential oil compared to control group. In conclusion, oral administration of 100 to 150 µl/kg bw of ginger rhizomes essential oil to laying Japanese quails positively influences egg weight and decreased serum and egg cholesterols without any adverse effect on feed intake and body weight gain.

CETP inhibition, statins and diabetes

Type 2 diabetes is a causal risk factor for the development of atherosclerotic cardiovascular disease (ASCVD). While treatment with a statin reduces the risk of having an ASCVD event in all people, including those with type-2 diabetes, statin treatment also increases the likelihood of new onset diabetes when given to those with risk factors for developing diabetes. Treatment with the cholesteryl ester transfer protein (CETP) inhibitor, anacetrapib, reduces the risk of having a coronary event over and above that achieved with a statin. However, unlike statins, anacetrapib decreases the risk of developing diabetes. If the reduced risk of new-onset diabetes is confirmed in another CETP inhibitor outcome trial, there will be a case for considering the use of the combination of a statin plus a CETP inhibitor in high ASCVD-risk people who are also at increased risk of developing diabetes.

Hepatic Overexpression of Endothelial Lipase Lowers High-Density Lipoprotein but Maintains Reverse Cholesterol Transport in Mice: Role of Scavenger Receptor Class B Type I/ATP-Binding Cassette Transporter A1-Dependent Pathways

Supplemental Digital Content is available in the text.

Objective—

Reverse cholesterol transport (RCT) is a major mechanism by which HDL (high-density lipoprotein) protects against atherosclerosis. Endothelial lipase (EL) reportedly reduces HDL levels, which, in theory, would increase atherosclerosis. However, it remains unclear whether EL affects RCT in vivo.

Approach and Results—

Adenoviral vectors expressing EL or luciferase were intravenously injected into mice, and a macrophage RCT assay was performed. As expected, hepatic EL overexpression markedly reduced HDL levels. In parallel, plasma ³H-cholesterol counts from the EL-expressing mice decreased by 85% compared with control. Surprisingly, there was no difference in fecal ³H-cholesterol excretion between the groups. Kinetic studies revealed increased catabolism/hepatic uptake of ³HDL-cholesteryl ether, resulting in no change in fecal HDL-cholesteryl ester excretion in the mice. To explore underlying mechanisms for the preservation of RCT despite low HDL levels in the EL-expressing mice, we investigated the effects of hepatic SR-BI (scavenger receptor class B type I) knockdown. RCT assay revealed that knockdown of SR-BI alone reduced fecal excretion of macrophage-derived ³H-cholesterol. Interestingly, hepatic EL overexpression under SR-BI inhibition further attenuated fecal tracer counts as compared with control. Finally, we observed that EL overexpression enhanced in vivo RCT under pharmacological inhibition of hepatic ABCA1 (ATP-binding cassette transporter A1) by probucol.

Conclusions—

Hepatic EL expression compensates for reduced macrophage-derived cholesterol efflux to plasma because of low HDL levels by promoting cholesterol excretion to bile/feces via an SR-BI pathway, maintaining overall RCT in vivo. In contrast, EL-modified HDL might negatively regulate RCT via hepatic ABCA1. Despite extreme hypoalphalipoproteinemia, RCT is maintained in EL-expressing mice via SR-BI/ABCA1-dependent pathways.

Blood Pressure Lowering Effect of Cuban Policosanol is Accompanied by Improvement of Hepatic Inflammation, Lipoprotein Profile, and HDL Quality in Spontaneously Hypertensive Rats

We investigated the antihypertensive effect of policosanol on spontaneously hypertensive rats (SHR). For this, we analyzed blood pressure, blood lipid, and lipoprotein properties in male SHR after consumption of Cuban policosanol (PCO). The experimental groups were as follows: normotensive Wistar Kyoto (WKY) control, SHR group fed normal diet (ND), SHR group fed 20 mg of PCO, SHR group fed 100 mg of PCO, and SHR group fed 200 mg of PCO per kg of body weight. After eight weeks, the SHR control group showed gradual increases up to 21% in systolic blood pressure (SBP) and diastolic blood pressure (DBP) compared with values at week 0. However, policosanol consumption had a dose-dependent reduction effect on SBP and also reduced DBP up to 17% in a dose-dependent manner. Heart rate (HR) bpm increased by six percent in the SHR control, whereas the 20 mg, 100 mg, and 200 mg of policosanol groups showed a reduction of 36%, 28%, and 34% respectively. Although serum total cholesterol (TC) level of SHR was not affected by policosanol consumption (70⁻80 mg/dL), serum triglyceride (TG) level significantly decreased in the SHR + 200 mg of PCO group. Serum high-density lipoprotein cholesterol (HDL-C) level was also significantly elevated by policosanol consumption. The % HDL-C/TC ratio was elevated in the policosanol group up to 67⁻70%, whereas the SHR control group showed a ratio of 58%. Serum cholesteryl ester transfer protein (CETP) activity was reduced by policosanol in a dose-dependent manner. Although the serum glutamate oxaloacetate transaminase (GOT)/ glutamate pyruvate transaminase (GPT) were similar across all groups, policosanol consumption caused reduction of reactive oxygen species (ROS) levels in hepatic tissue. The SHR control group showed a 2.1-fold higher serum C-reactive protein (CRP) level than the WKY group, whereas the CRP level decreased in the SHR + 200 mg of PCO group (up to 45%) than SHR control group. Aldosterone level was reduced in the policosanol group (up to 34%) in a dose-dependent manner compared to the control. In conclusion, eight weeks of policosanol consumption in SHR resulted in remarkable reduction of blood pressure, serum aldosterone, and serum TG levels along with the elevation of HDL-C and improvement of hepatic inflammation.

Genetics of familial hypercholesterolemia: a tool for development of novel lipid lowering pharmaceuticals?

PURPOSE OF REVIEW

Familial hypercholesterolemia is characterized by high LDL cholesterol and an elevated risk to develop coronary heart disease. Mutations in LDL receptor-mediated cholesterol uptake are the main cause of familial hypercholesterolemia. However, multiple mutations in various other genes are also associated with high LDL cholesterol and even familial hypercholesterolemia. Thus, pharmaceuticals that target these genes and proteins might be attractive treatment options to reduce LDL cholesterol. This review provides an overview of the recent developments and clinical testing of such pharmaceuticals.

RECENT FINDINGS

About 80 genes are associated with hypercholesterolemia but only pharmaceuticals that inhibit cholesteryl ester transfer protein (CETP), angiopoietin-related protein 3 (ANGPTL3), and apolipoprotein C-III (apoC-III) have recently been tested in clinical trials. Inhibition of CETP and ANGPTL3 lowered LDL cholesterol. ANGPTL3 inhibition had the largest effect and was even effective in familial hypercholesterolemia patients. The effect of apoC-III inhibition on LDL cholesterol is not conclusive.

SUMMARY

Of the many potential pharmaceutical targets involved in LDL cholesterol, only a few have been studied so far. Of these, pharmaceuticals that inhibit CETP or ANGPTL3 are promising novel treatment options to reduce LDL cholesterol but the effect of apoC-III inhibition requires more research.

Therapy with cholesteryl ester transfer protein (CETP) inhibitors and diabetes risk

BACKGROUND

Cholesteryl ester transfer protein (CETP) inhibitors are a class of drugs that targets the CETP enzyme to significantly increase serum high-density lipoprotein cholesterol (HDL-C) and decrease low-density lipoprotein cholesterol (LDL-C) levels. As HDL-C has potential antidiabetic properties, and the beneficial effects of CETP drugs on glucose homoeostasis have not been sufficiently studied, the aims of this study were: (1) to evaluate the effect of CETP inhibitors on the incidence of diabetes; and (2) to assess the association between CETP inhibitor-induced changes in HDL-C levels and incidence of diabetes.

METHODS

A meta-analysis was performed of randomized controlled clinical trials of CETP inhibitor therapy, either alone or combined with other lipid-lowering drugs, reporting data from new cases of diabetes with a minimum of 6 months of follow-up, after searching the PubMed/MEDLINE, Embase and Cochrane Controlled Trials databases. A fixed-effects meta-regression model was then applied.

RESULTS

Four eligible trials of CETP inhibitors, involving a total of 73,479 patients, were considered for the analyses, including 960 newly diagnosed cases of diabetes in the CTEP inhibitor group vs 1086 in the placebo group. CETP inhibitor therapy was associated with a significant 12% reduction in incidence of diabetes (OR: 0.88, 95% CI: 0.81-0.96; P=0.005). Assessment of the relationship between on-treatment HDL-C and the effect of CETP inhibitors showed a statistically non-significant trend (Z=-1.13, P=0.26).

CONCLUSION

CETP inhibitors reduced the incidence of diabetes. The improvement in glucose metabolism may have been related, at least in part, to the increase in HDL-C concentration.

Design, Synthesis, and Biological Evaluation of N,N-Disubstituted-4-Arylthiazole-2-Methylamine Derivatives as Cholesteryl Ester Transfer Inhibitors

Cholesteryl ester transfer protein (CETP) has been identified as a potential target for cardiovascular disease (CVD) for its important role in the reverse cholesteryl transfer (RCT) process. In our previous work, compound 5 was discovered as a moderate CETP inhibitor. The replacement of the amide linker by heterocyclic aromatics and then a series of N,N-substituted-4-arylthiazole-2-methylamine derivatives were designed by utilizing a conformational restriction strategy. Thirty-six compounds were synthesized and evaluated for their CETP inhibitory activities. Structure-activity relationship studies indicate that electron donor groups substituted ring A, and electron-withdrawing groups at the 4-position of ring B were critical for potency. Among these compounds, compound 30 exhibited excellent CETP inhibitory activity (IC₅₀ = 0.79 ± 0.02 μM) in vitro and showed an acceptable metabolic stability.

Anacetrapib, a New CETP Inhibitor: The New Tool for the Management of Dyslipidemias?

Cholesteryl ester transfer protein (CETP) inhibitors significantly increase serum high-density lipoprotein cholesterol (HDL) cholesterol levels and decrease low-density lipoprotein cholesterol (LDL) cholesterol concentration. However, three drugs of this class failed to show a decrease of cardiovascular events in high-risk patients. A new CETP inhibitor, anacetrapib, substantially increases HDL cholesterol and apolipoprotein (Apo) AI levels with a profound increase of large HDL2 particles, but also pre-β HDL particles, decreases LDL cholesterol levels mainly due to increased catabolism of LDL particles through LDL receptors, decreases lipoprotein a (Lp(a)) levels owing to a decreased Apo (a) production and, finally, decreases modestly triglyceride (TRG) levels due to increased lipolysis and increased receptor-mediated catabolism of TRG-rich particles. Interestingly, anacetrapib may be associated with a beneficial effect on carbohydrate homeostasis. Furthermore, the Randomized EValuation of the Effects of Anacetrapib Through Lipid-modification (REVEAL) trial showed that anacetrapib administration on top of statin treatment significantly reduces cardiovascular events in patients with atherosclerotic vascular disease without any significant increase of adverse events despite its long half-life. Thus, anacetrapib could be useful for the effective management of dyslipidemias in high-risk patients that do not attain their LDL cholesterol target or are statin intolerable, while its role in patients with increased Lp(a) levels remains to be established.

A novel swine model for evaluation of dyslipidemia and atherosclerosis induced by human CETP overexpression

Background

The mechanism of cholesteryl ester transfer protein (CETP) in lipid metabolism is still unclear. Furthermore, the relationship of CETP and atherosclerosis (AS) has been controversial. As pigs are a good model for both lipid and AS research, we investigated the lipid metabolism of human CETP (hCETP) transgenic pigs and explored the mechanism of CETP in lipid modulation.

Methods

Plasmids expressing the hCETP gene were designed, successfully constructed, and transfected into porcine fetal fibroblasts by liposomes. Using somatic cell nuclear transfer technology and embryonic transfer, hCETP transgenic pigs were generated. After the DNA, RNA, and protein levels were identified, positive hCETP transgenic pigs were selected. Blood samples were collected at different ages to evaluate the phenotypes of biochemical markers, and the metabolomes of plasma samples were analyzed by liquid mass spectrometry.

Results

Eight positive hCETP transgenic pigs and five negative cloned pigs were generated by transgenic technology. Finally, five hCETP transgenic and five cloned pigs were grown healthily. After feeding with a normal diet, hCETP transgenic pigs compared with unmodified pigs had no significant differences in body weight, liver function, kidney function, or plasma ions, while total cholesterol and low-density lipoprotein were higher than in unmodified pigs, and high-density lipoprotein was significantly decreased. Metabolomics analysis showed that there were differences in metabolic components between hCETP transgenic pigs, cloned pigs, and unmodified pigs.

Conclusions

In this study, we created hCETP transgenic pigs that could serve as an excellent model for lipid disorders and atherosclerosis.

Electronic supplementary material

The online version of this article (10.1186/s12944-017-0563-x) contains supplementary material, which is available to authorized users.

Association of RBM5 rs2013208 SNP with serum lipid levels in two Chinese ethnic groups

The RNA binding motif protein 5 gene (RBM5) rs2013208 single nucleotide polymorphism (SNP) has been associated with high-density lipoprotein cholesterol (HDL-C) levels in a previous genome-wide association study, but little is known about such association of the RBM5 rs2013208 SNP and serum lipid profiles in the Chinese populations. The present study was to detect the association of the RBM5 rs2013208 SNP and several environmental factors with serum lipid levels in the Jing and Han populations. Genotyping of the RBM5 rs2013208 SNP in 635 subjects of Jing and 648 participants of Han peoples was performed by polymerase chain reaction and restriction fragment length polymorphism, and then confirmed by direct sequencing. There were no significant differences in the genotypic and allelic frequencies of the RBM5 rs2013208 SNP between the two ethnic groups or between males and females. The RBM5 rs2013208G allele carriers had lower serum HDL-C levels in both Jing and Han than the G allele non-carriers. The G allele carriers in Jing had higher serum total cholesterol (TC) levels and higher apolipoprotein (Apo) A1/ApoB ratio than the G allele non-carriers (P < 0.05). Subgroup analysis according to sex showed that the G allele carriers had lower serum HDL-C levels in both Jing and Han females but not in males (P < 0.05). The G allele carriers had higher TC levels in Jing females but not in Jing males, and lower ApoA1/ApoB ratio in Jing males but not in Jing females. Serum lipid parameters were also correlated with several environmental factors in the Jing and Han populations, or in males and females in both ethnic groups. The association of the RBM5 rs2013208 SNP and serum lipid levels is different between the Jing and Han populations. These associations might have an ethnic- and/or sex-specificity.

Moringa Leaves Prevent Hepatic Lipid Accumulation and Inflammation in Guinea Pigs by Reducing the Expression of Genes Involved in Lipid Metabolism

To investigate the mechanisms by which Moringa oleifera leaves (ML) modulate hepatic lipids, guinea pigs were allocated to either control (0% ML), 10% Low Moringa (LM) or 15% High Moringa (HM) diets with 0.25% dietary cholesterol to induce hepatic steatosis. After 6 weeks, guinea pigs were sacrificed and liver and plasma were collected to determine plasma lipids, hepatic lipids, cytokines and the expression of genes involved in hepatic cholesterol (CH) and triglyceride (TG) metabolism. There were no differences in plasma lipids among groups. A dose-response effect of ML was observed in hepatic lipids (CH and TG) with the lowest concentrations in the HM group (p < 0.001), consistent with histological evaluation of lipid droplets. Hepatic gene expression of diglyceride acyltransferase-2 and peroxisome proliferator activated receptor-γ, as well as protein concentrations interleukin (IL)-1β and interferon-γ, were lowest in the HM group (p < 0.005). Hepatic gene expression of cluster of differentiation-68 and sterol regulatory element binding protein-1c were 60% lower in both the LM and HM groups compared to controls (p < 0.01). This study demonstrates that ML may prevent hepatic steatosis by affecting gene expression related to hepatic lipids synthesis resulting in lower concentrations of cholesterol and triglycerides and reduced inflammation in the liver.

Cardiac Lymphatics - A New Avenue for Therapeutics?

Recent progress in lymphatic vessel biology and in novel imaging techniques has established the importance of the lymphatic vasculature as part of the cardiovascular system. The lymphatic vessel network regulates many physiological processes important for heart function such as fluid balance, transport of extravasated proteins, and trafficking of immune cells. Therefore, lymphangiogenic therapy could be beneficial in the treatment of cardiovascular diseases, for example by improving reverse cholesterol transport (RCT) from atherosclerotic lesions or by resolving edema and fibrosis after myocardial infarction. In this review we first describe recent findings on the development and function of cardiac lymphatic vessels, and subsequently focus on the prospects of pro- and anti-lymphangiogenic therapies in cardiovascular diseases.

Association of the FADS gene cluster with coronary artery disease and plasma lipid concentrations in the northern Chinese Han population

We investigated the association of single nucleotide polymorphisms (SNPs) in the fatty acid desaturase (FADS) gene cluster with coronary artery disease (CAD) in a case-control study and evaluated the possible influence of genetic variation on total cholesterol (TC) and triglyceride concentrations in the controls. In total, 497 CAD patients and 495 unrelated controls were genotyped for eight SNPs in the FADS gene cluster, and the blood lipid levels of subjects were measured. Three genetic models, including codominant, dominant and recessive, were used to analyze the genotypic relationship with CAD and plasma lipid levels. Single locus genotypic analysis revealed that rs1000778 in FADS3 under a recessive model (AA vs. GG-GA) was significantly associated with CAD adjusted for risk factors. The rs1000778 minor allele AA was associated with a lower risk of CAD (OR =0.37, 95% CI: 0.15-0.89, P=0.025). In the control group, there were significant differences in TC concentrations under a recessive genetic model for rs174575 (C/G) in FADS2 and for rs174450 (A/C) and rs7115739 (G/T) in FADS3 (P=0.053, 0.016 and 0.018, respectively). The rs1000778-G variant in FADS3 may contribute to the susceptibility of CAD, but the result needs to be further confirmed because of small sample size in our study. Genetic variations in FADS2 and FADS3 influence TC concentration in the northern Chinese Han population.

Anacetrapib, but not evacetrapib, impairs endothelial function in CETP-transgenic mice in spite of marked HDL-C increase

BACKGROUND AND AIMS

High-density lipoprotein cholesterol (HDL-C) is inversely related to cardiovascular risk. HDL-C raising ester transfer protein (CETP) inhibitors, are novel therapeutics. We studied the effects of CETP inhibitors anacetrapib and evacetrapib on triglycerides, cholesterol and lipoproteins, cholesterol efflux, paraoxonase activity (PON-1), reactive oxygen species (ROS), and endothelial function in E3L and E3L.CETP mice.

METHODS

Triglycerides and cholesterol were measured at weeks 5, 14 and 21 in E3L.CETP mice on high cholesterol diet and treated with anacetrapib (3 mg/kg/day), evacetrapib (3 mg/kg/day) or placebo. Cholesterol efflux was assessed ex-vivo in mice treated with CETP inhibitors for 3 weeks on a normal chow diet. Endothelial function was analyzed at week 21 in isolated aortic rings, and serum lipoproteins assessed by fast-performance liquid chromatography.

RESULTS

Anacetrapib and evacetrapib increased HDL-C levels (5- and 3.4-fold, resp.) and reduced triglycerides (-39% vs. placebo, p = 0.0174). Total cholesterol levels were reduced only in anacetrapib-treated mice (-32%, p = 0.0386). Cholesterol efflux and PON-1 activity (+45% and +35% vs. control, p < 0.005, resp.) were increased, while aortic ROS production was reduced with evacetrapib (-49% vs. control, p = 0.020). Anacetrapib, but not evacetrapib, impaired endothelium dependent vasorelaxation (p < 0.05). In contrast, no such effects were observed in E3L mice for all parameters tested.

CONCLUSIONS

Notwithstanding a marked rise in HDL-C, evacetrapib did not improve endothelial function, while anacetrapib impaired it, suggesting that CETP inhibition does not provide vascular protection. Anacetrapib exerts unfavorable endothelial effects beyond CETP inhibition, which may explain the neutral results of large clinical trials in spite of increased HDL-C.

Plaque imaging to refine indications for emerging lipid-lowering drugs

Statins have been effective in reducing adverse cardiovascular events. Their benefits have been proportional to the level of plasma LDL-cholesterol reduction and seem to extend to patients with 'normal' levels of cholesterol at outset. Statins are also inexpensive and have a favourable side-effect profile. As a result, they are used widely (almost indiscriminately) in patients with atherosclerotic vascular disease, and in those at risk of disease. Next generation lipid-modifying drugs seem unlikely to offer the same simplicity of application. The recent trials of new classes of lipid modifying drugs underline the need for a risk stratification tool which is not based on patients' category of diagnosis (for example, post-myocardial infarction) but based on the characterization of disease in that individual patient. Mechanistic staging, a process that matches the target of the drug action with an identifiable disease characteristic, may offer an opportunity to achieve more precise intervention. The upshots of this targeted approach will be greater efficacy, requiring smaller clinical trials to demonstrate effectiveness; a reduced number needed to treat to yield benefits and more cost-effective prescribing. This will be important, as purchasers require ever more rigorous demonstration of both efficacy and cost-effectiveness. In this context, we will discuss available pharmacological strategies of lipid reduction in anti-atherosclerotic treatment and how plaque imaging techniques may provide an ideal method in stratifying patients for new lipid-modifying drugs.

Mendelian Randomization Analyses for Selection of Therapeutic Targets for Cardiovascular Disease Prevention: a Note of Circumspection

Genetic factors identified from genome-wide association studies have been used to understand causative variants for complex diseases. Studies conducted on large populations of individuals from many geographical regions have provided insights into genetic pathways involved in the causal pathway for atherosclerotic cardiovascular disease. A single genetic trait may ineffectively evaluate the pathway of interest, and it may not account for other complementary genetic pathways that may be activated at various stages of the disease process or evidence-based therapies that alter the molecular and cellular milieu.

High-density lipoprotein reduces inflammation from cholesterol crystals by inhibiting inflammasome activation

Interleukin-1β (IL-1β), a potent pro-inflammatory cytokine, has been implicated in many diseases, including atherosclerosis. Activation of IL-1β is controlled by a multi-protein complex, the inflammasome. The exact initiating event in atherosclerosis is unknown, but recent work has demonstrated that cholesterol crystals (CC) may promote atherosclerosis development by activation of the inflammasome. High-density lipoprotein (HDL) has consistently been shown to be anti-atherogenic and to have anti-inflammatory effects, but its mechanism of action is unclear. We demonstrate here that HDL is able to suppress IL-1β secretion in response to cholesterol crystals in THP-1 cells and in human-monocyte-derived macrophages. HDL is able to blunt inflammatory monocyte cell recruitment in vivo following intraperitoneal CC injection in mice. HDL appears to modulate inflammasome activation in several ways. It reduces the loss of lysosomal membrane integrity following the phagocytosis of CC, but the major mechanism for the suppression of inflammasome activation by HDL is decreased expression of pro-IL-1β and NLRP3, and reducing caspase-1 activation. In summary, we have described a novel anti-inflammatory effect of HDL, namely its ability to suppress inflammasome activation by CC by modulating the expression of several key components of the inflammasome.

Genetic variants in CETP increase risk of intracerebral hemorrhage

Objective

In observational epidemiologic studies, higher plasma high‐density lipoprotein cholesterol (HDL‐C) has been associated with increased risk of intracerebral hemorrhage (ICH). DNA sequence variants that decrease cholesteryl ester transfer protein (CETP) gene activity increase plasma HDL‐C; as such, medicines that inhibit CETP and raise HDL‐C are in clinical development. Here, we test the hypothesis that CETP DNA sequence variants associated with higher HDL‐C also increase risk for ICH.

Methods

We performed 2 candidate‐gene analyses of CETP. First, we tested individual CETP variants in a discovery cohort of 1,149 ICH cases and 1,238 controls from 3 studies, followed by replication in 1,625 cases and 1,845 controls from 5 studies. Second, we constructed a genetic risk score comprised of 7 independent variants at the CETP locus and tested this score for association with HDL‐C as well as ICH risk.

Results

Twelve variants within CETP demonstrated nominal association with ICH, with the strongest association at the rs173539 locus (odds ratio [OR] = 1.25, standard error [SE] = 0.06, p = 6.0 × 10⁻⁴) with no heterogeneity across studies (I² = 0%). This association was replicated in patients of European ancestry (p = 0.03). A genetic score of CETP variants found to increase HDL‐C by ∼2.85mg/dl in the Global Lipids Genetics Consortium was strongly associated with ICH risk (OR = 1.86, SE = 0.13, p = 1.39 × 10⁻⁶).

Interpretation

Genetic variants in CETP associated with increased HDL‐C raise the risk of ICH. Given ongoing therapeutic development in CETP inhibition and other HDL‐raising strategies, further exploration of potential adverse cerebrovascular outcomes may be warranted. Ann Neurol 2016;80:730–740

New Era of Lipid-Lowering Drugs

There are several established lipid-modifying agents, including statins, fibrates, niacin, and ezetimibe, that have been shown in randomized clinical outcome trials to reduce the risk of having an atherosclerotic cardiovascular event. However, in many people, the risk of having an event remains unacceptably high despite treatment with these established agents. This has stimulated the search for new therapies designed to reduce residual cardiovascular risk. New approaches that target atherogenic lipoproteins include: 1) inhibition of proprotein convertase subtilisin/kexin type 9 to increase removal of atherogenic lipoproteins from plasma; 2) inhibition of the synthesis of apolipoprotein (apo) B, the main protein component of atherogenic lipoproteins; 3) inhibition of microsomal triglyceride transfer protein to block the formation of atherogenic lipoproteins; 4) inhibition of adenosine triphosphate citrate lyase to inhibit the synthesis of cholesterol; 5) inhibition of the synthesis of lipoprotein(a), a factor known to cause atherosclerosis; 6) inhibition of apoC-III to reduce triglyceride-rich lipoproteins and to enhance high-density lipoprotein (HDL) functionality; and 7) inhibition of cholesteryl ester transfer protein, which not only reduces the concentration of atherogenic lipoproteins but also increases the level and function of the potentially antiatherogenic HDL fraction. Other new therapies that specifically target HDLs include infusions of reconstituted HDLs, HDL delipidation, and infusions of apoA-I mimetic peptides that mimic some of the functions of HDLs. This review describes the scientific basis and rationale for developing these new therapies and provides a brief summary of established therapies.

Design, synthesis and biological evaluation of novel cholesteryl ester transfer protein inhibitors bearing a cycloalkene scaffold

Cholesteryl ester transfer protein (CETP) is a potential target for cardiovascular disease therapy as inhibition of CETP leads to increased HDL-C in humans. Based on the structure of Merck's biphenyl CETP inhibitor, we designed novel N,N-substituted-cycloalkenyl-methylamine scaffold derivatives by utilizing core replacement and conformational restriction strategies. Consequently, twenty-eight compounds were synthesized and evaluated for their inhibitory activity against CETP. Their preliminary structure-activity relationships (SARs) studies indicate that polar substituents were tolerated in moiety A and hydrophobic alkyl groups at the 5-position of cyclohexene were critical for potency. Among them, compound 17a, bearing an N-(5-pyrazolyl-pyrimidin-2-yl)-cycloalkenyl- methylamine scaffold, exhibited excellent CETP inhibitory activity (IC50 = 0.07 μM) in vitro. Furthermore, it showed an acceptable pharmacokinetic profile in S-D rats and efficient HDL-C increase in high-fat fed hamsters.

Hypertension, lipoprotein subclasses and lipid transfer proteins in obese children and adolescents

BACKGROUND

Obesity-related childhood hypertension is associated with disturbances of serum lipids, but less is known about distribution of lipoprotein subclasses and activities of proteins involved in reverse cholesterol transport in hypertensive obese children. Our objective was to determine low-density lipoprotein (LDL) and high-density lipoprotein (HDL) subclasses distribution and activities of lecithin:cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein (CETP) in hypertensive and non-hypertensive obese children.

METHODS

A total of 40 hypertensive and 25 non-hypertensive obese children were enrolled. Lipoprotein subclasses were assessed by polyacrylamide gradient gel electrophoresis. LCAT and CETP activities were determined as a rate of formation and a rate of transfer of cholesteryl esters.

RESULTS

Despite of comparable values of serum lipid parameters, a shift toward smaller LDL and HDL subclasses was observed in hypertensive compared to normotensive obese children. Activities of LCAT were similar, but proatherogenic CETP activities were significantly higher in the hypertensive group (p = 0.036). LCAT/net CETP ratio inversely correlated with relative proportion of small, dense LDL particles (ρ = -0.423; p = 0.025) in the group with hypertension.

CONCLUSIONS

The results of our study demonstrated a tendency toward altered distribution of lipoprotein subclasses in favor of more proatherogenic particles in childhood hypertension. Also, hypertensive obese children had increased proatherogenic CETP activity.

Human serum preβ1-high density lipoprotein levels are independently and negatively associated with coronary artery diseases

BACKGROUND

Serum preβ1-high density lipoprotein (preβ1-HDL) was defined by two-dimensional non-denaturing linear gel electrophoresis and apolipoprotein A-I immuno-blotting. Serum preβ1-HDL seems to play an important role in reverse cholesterol transport, a well-known anti-atherosclerosis process. However, there are still debatable questions for its quantification and coronary artery disease (CAD) relevance.

METHODS

We isolated the preβ1-HDL using a new native polyacrylamide gel electrophoresis (PAGE) system and lipid pre-staining serum. We established a two-demensional gel electrophoresis system.

RESULTS

We measured the preβ1-HDL in Tangier disease patients and subjects with cholesterol ester transfer protein (CETP) mutation. The preβ1-HDL is clearly separated from lipid-free apoA-I monomer and cannot be converted into other HDL particles under lecithin-cholesterol acyltransferase (LCAT) inhibition. This preβ1-HDL is a spheroidal particle with the highest apoA-1/cholesterol ratio and highest density (≥1.21 g/ml), as compared with all other HDLs. Importantly, we found that serum from subjects with Tangier disease or with cholesterol ester transfer protein (CETP) mutation have no detectible preβ1-HDL particles. We recruited a total of 102 subjects underwent diagnostic coronary angiography and measured their preβ1-HDL levels. Among them, 56 had no stenosis of coronary artery and 46 were diagnosed as CAD, which was predefined as the presence of a luminal diameter stenosis ≥50 % in at least 1 major coronary artery territory. We found that preβ1-HDL is independently and negatively associated with the severity of the coronary artery stenosis (Gensini score).

CONCLUSION

We established a novel and simple method for human serum preβ1-HDL quantification. We found that human lower preβ1-HDL is an independent predictor for severer coronary artery stenosis.

CETP Lowers TLR4 Expression Which Attenuates the Inflammatory Response Induced by LPS and Polymicrobial Sepsis

Sepsis is a systemic inflammatory response to infection eliciting high mortality rate which is a serious health problem. Despite numerous studies seeking for therapeutic alternatives, the mechanisms involved in this disease remain elusive. In this study we evaluated the influence of cholesteryl ester transfer protein (CETP), a glycoprotein that promotes the transfer of lipids between lipoproteins, on the inflammatory response in mice. Human CETP transgenic mice were compared to control mice (wild type, WT) after polymicrobial sepsis induced by cecal ligation and puncture (CLP), aiming at investigating their survival rate and inflammatory profiles. Macrophages from the peritoneal cavity were stimulated with LPS in the presence or absence of recombinant CETP for phenotypic and functional studies. In comparison to WT mice, CETP mice showed higher survival rate, lower IL-6 plasma concentration, and decreased liver toll-like receptor 4 (TLR4) and acyloxyacyl hydrolase (AOAH) protein. Moreover, macrophages from WT mice to which recombinant human CETP was added decreased LPS uptake, TLR4 expression, NF-κB activation and IL-6 secretion. This raises the possibility for new therapeutic tools in sepsis while suggesting that lowering CETP by pharmacological inhibitors should be inconvenient in the context of sepsis and infectious diseases.

HDL functionality in reverse cholesterol transport--Challenges in translating data emerging from mouse models to human disease

Whereas LDL-derived cholesterol accumulates in atherosclerotic lesions, HDL particles are thought to facilitate removal of cholesterol from the lesions back to the liver thereby promoting its fecal excretion from the body. Because generation of cholesterol-loaded macrophages is inherent to atherogenesis, studies on the mechanisms stimulating the release of cholesterol from these cells and its ultimate excretion into feces are crucial to learn how to prevent lesion development or even induce lesion regression. Modulation of this key anti-atherogenic pathway, known as the macrophage-specific reverse cholesterol transport, has been extensively studied in several mouse models with the ultimate aim of applying the emerging knowledge to humans. The present review provides a detailed comparison and critical analysis of the various steps of reverse cholesterol transport in mouse and man. We attempt to translate this in vivo complex scenario into practical concepts, which could serve as valuable tools when developing novel HDL-targeted therapies.

Cholesteryl Ester Transfer Protein Inhibition Is Not Yet Dead—Pro

Cholesteryl ester transfer protein (CETP) transfers cholesteryl esters from nonatherogenic high-density lipoproteins to potentially proatherogenic non–high-density lipoprotein fractions. Human genetic studies and human cohort studies have concluded that CETP gene polymorphisms associated with decreased CETP activity are accompanied by a significantly lower risk of atherosclerotic cardiovascular disease. Inhibition of CETP in rabbits reduces development of diet-induced atherosclerosis. Inhibition of CETP in humans reduces non–high-density lipoprotein cholesterol while increasing high-density lipoproteins cholesterol, consistent with a reduced risk of having an atherosclerotic cardiovascular disease event. The failure of randomized human clinical outcome trials with 3 different CETP inhibitors may have been the consequence of either off-target adverse effects of the drug used or problems with the design of the trials. The hypothesis that CETP inhibition reduces atherosclerotic cardiovascular disease risk is still untested. The future of CETP inhibition as a cardio-protective strategy will depend on the outcome of the ongoing Randomized Evaluation of the Effects of Anacetrapib Through Lipid-Modification (REVEAL) trial with the CETP inhibitor, anacetrapib.

Does high-density lipoprotein protect vascular function in healthy pregnancy?

The maternal adaptation to pregnancy includes hyperlipidaemia, oxidative stress and chronic inflammation. In non-pregnant individuals, these processes are usually associated with poor vascular function. However, maternal vascular function is enhanced in pregnancy. It is not understood how this is achieved in the face of the adverse metabolic and inflammatory environment. Research into cardiovascular disease demonstrates that plasma HDL (high-density lipoprotein), by merit of its functionality rather than its plasma concentration, exerts protective effects on the vascular endothelium. HDL has vasodilatory, antioxidant, anti-thrombotic and anti-inflammatory effects, and can protect against endothelial cell damage. In pregnancy, the plasma HDL concentration starts to rise at 10 weeks of gestation, peaking at 20 weeks. The initial rise in plasma HDL occurs around the time of the establishment of the feto-placental circulation, a time when the trophoblast plugs in the maternal spiral arteries are released, generating oxidative stress. Thus there is the intriguing possibility that new HDL of improved function is synthesized around the time of the establishment of the feto-placental circulation. In obese pregnancy and, to a greater extent, in pre-eclampsia, plasma HDL levels are significantly decreased and maternal vascular function is reduced. Wire myography studies have shown an association between the plasma content of apolipoprotein AI, the major protein constituent of HDL, and blood vessel relaxation. These observations lead us to hypothesize that HDL concentration, and function, increases in pregnancy in order to protect the maternal vascular endothelium and that in pre-eclampsia this fails to occur.

Probucol-Oxidized Products, Spiroquinone and Diphenoquinone, Promote Reverse Cholesterol Transport in Mice

OBJECTIVE

Oxidized products of probucol, spiroquinone and diphenoquinone, were shown to increase cell cholesterol release and plasma high-density lipoprotein (HDL) by inhibiting degradation of ATP-binding cassette transporter A1. We investigated whether these compounds enhance reverse cholesterol transport in mice.

APPROACH AND RESULTS

Spiroquinone and diphenoquinone increased ATP-binding cassette transporter A1 protein (2.8- and 2.6-fold, respectively, P<0.01) and apolipoprotein A-I-mediated cholesterol release (1.4- and 1.4-fold, P<0.01 and P<0.05, respectively) in RAW264.7 cells. However, diphenoquinone, but not spiroquinone, enhanced cholesterol efflux to HDL (+12%, P<0.05), whereas both increased ATP-binding cassette transporter G1 protein, by 1.8- and 1.6-fold, respectively. When given orally to mice, both compounds significantly increased plasma HDL-cholesterol, by 19% and 20%, respectively (P<0.05), accompanied by an increase in hepatic and macrophage ATP-binding cassette transporter A1 but not ATP-binding cassette transporter G1. We next evaluated in vivo reverse cholesterol transport by injecting RAW264.7 cells labeled with (3)H-cholesterol intraperitoneally into mice. Both spiroquinone and diphenoquinone increased fecal excretion of the macrophage-derived (3)H-tracer, by 25% and 28% (P<0.01 and P<0.05), respectively. spiroquinone/diphenoquinone did not affect fecal excretion of HDL-derived (3)H-cholesterol, implying that macrophage-to-plasma was the most important step in spiroquinone/diphenoquinone-mediated promotion of in vivo reverse cholesterol transport. Finally, spiroquinone significantly reduced aortic atherosclerosis in apolipoprotein E null mice when compared with the vehicle.

CONCLUSIONS

Spiroquinone and diphenoquinone increase functional ATP-binding cassette transporter A1 in both the macrophages and the liver, elevate plasma HDL-cholesterol, and promote overall reverse cholesterol transport in vivo. These compounds are promising as therapeutic reagents against atherosclerosis.