Pharmacokinetics, pharmacodynamics and clinical efficacy of non-statin treatments for hypercholesterolemia

The LEPIS-HuR-TMOD4 axis regulates hepatic cholesterol homeostasis and accelerates atherosclerosis

BACKGROUND AND AIMS

Long noncoding RNAs (lncRNAs) play important roles in the progression of atherosclerosis. In this study, we identified an uncharacterized lncRNA, Liver Expressions by PSRC1 Induced Specifically (LEPIS). This study aimed to clarify the mechanism though which LEPIS affects atherosclerosis (AS).

METHODS

The expression of LEPIS and its potential target, tropomodulin 4 (TMOD4), was increased in the livers of ApoE-/- mice fed a high-fat diet (HFD). An ApoE-/- mouse model in which LEPIS or TMOD4 was overexpressed in the liver was established. The plaque load in the aorta was assessed, plasma was collected to measure blood lipid levels, and the liver was collected to study cholesterol metabolism.

RESULTS

We found that both LEPIS and TMOD4 increased the AS burden and reduced hepatic cholesterol levels. A further study revealed that LEPIS and TMOD4 affected the expression of genes related to hepatic cholesterol homeostasis, including proprotein convertase subtilisin/kexin type 9 (PCSK9) and low-density lipoprotein receptor (LDLR), which are closely related to hypercholesterolemia. Mechanistically, human antigen R (HuR), an RNA-binding protein (RBP), was shown to be critical for the regulation of TMOD4 by LEPIS. Furthermore, we found that verexpression of LEPIS promoted the shuttling of HuR from the nucleus to the cytoplasm, enhanced the stability of TMOD4 mRNA, and in turn promoted the expression of TMOD4. In addition, TMOD4 was found to affect intracellular cholesterol levels through PCSK9.

CONCLUSIONS

These results suggest that the LEPIS-HuR-TMOD4 axis is a potential intervention target for dysregulated hepatic cholesterol homeostasis and AS and may provide the basis for further reductions in the circulating LDL-C concentration and arterial plaque burden.

Beyond statins: New pharmacological targets to decrease LDL-cholesterol and cardiovascular events

The pharmacological treatment of dyslipidemia, a major modifiable risk factor for developing atherosclerotic cardiovascular disease (ASCVD), remains a debated and controversial issue, not only in terms of the most appropriate therapeutic range for lipid levels, but also with regard to the optimal strategy and sequence approach (stepwise vs upstream therapy). Current treatment guidelines for the management of dyslipidemia focus on the intensity of low-density lipoprotein cholesterol (LDL-C) reduction, stratified according to risk for developing ASCVD. Beyond statins and ezetimibe, different medications targeting LDL-C have been recently approved by regulatory agencies with potential innovative mechanisms of action, including proprotein convertase subtilisin/kexin type 9 modulators (monoclonal antibodies such as evolocumab and alirocumab; small interfering RNA molecules such as inclisiran), ATP-citrate lyase inhibitors (bempedoic acid), angiopoietin-like 3 inhibitors (evinacumab), and microsomal triglyceride transfer protein inhibitors (lomitapide). An understanding of their pharmacological aspects, benefit-risk profile, including impact on hard cardiovascular endpoints beyond LDL-C reduction, and potential advantages from the patient perspective (e.g., adherence) - the focus of this evidence-based review - is crucial for practitioners across medical specialties to minimize therapeutic inertia and support clinical practice.

Lipoprotein(a) Serum Levels Predict Pulse Wave Velocity in Subjects in Primary Prevention for Cardiovascular Disease with Large Apo(a) Isoforms: Data from the Brisighella Heart Study

In the last decades, high serum levels of lipoprotein(a) (Lp(a)) have been associated with increased cardiovascular disease (CVD) risk, in particular among individuals with smaller apolipoprotein(a) (apo(a)) isoforms than those with larger sizes. The aim of our analysis was to evaluate whether Lp(a) levels could predict early vascular aging, and whether smaller apo(a) isoforms had a predictive value for vascular aging different than larger apo(a) isoforms in a cohort of subjects free from CVD. We considered the data of a subset of Brisighella Heart Study (BHS) participants free from CVD (462 men and 516 women) who were clinically evaluated during the 2012 BHS population survey. Predictors of arterial stiffness, measured as carotid-femoral pulse wave velocity (cfPWV) were estimated by the application of a step-wise linear regression model. In our cohort, there were 511 subjects with small apo(a) size and 467 subjects with large apo(a) isoforms. Subjects with larger apo(a) isoform sizes had significantly lower serum levels of Lp(a). In the BHS subpopulation sample, cfPWV was predicted by age, systolic blood pressure (SBP), serum levels of high-density lipoprotein cholesterol (HDL-C), triglycerides (TG) and sex, higher HDL-C serum levels and female sex associated with lower values of cfPWV. In subjects with smaller apo(a) isoform sizes, predictors of cfPWV were age, SBP, sex and serum levels of HDL-C, being higher HDL-C serum levels and female sex associated to lower values of cfPWV. In subjects with larger apo(a) isoform sizes, cfPWV was predicted by age, SBP, serum levels of Lp(a) and sex, with female sex associated with lower values of cfPWV. In our subpopulation sample, Lp(a) did not predict cfPWV. However, in subjects with large apo(a) isoform sizes, Lp(a) was a significant predictor of arterial stiffness.

An expert opinion paper on statin adherence and implementation of new lipid-lowering medications by the ESC Working Group on Cardiovascular Pharmacotherapy: Barriers to be overcome

Benefits and safety on statins have been well-established over 20 years of research. Despite this, the vast majority of patients are not adequately treated and do not achieve the low-density lipoprotein cholesterol target levels. This is mainly due to poor adherence, which is associated with dangerous and sometimes fatal outcomes. To increase adherence and prevent worse outcomes, a combination therapy with lower dosage of statins and new lipid-lowering drugs may be used. However, the implementation of new lipid-lowering drugs in European countries is still at the beginning. For these reasons, the aim of this position paper is to give an up-to-date indication from the ESC Working Group on Cardiovascular Pharmacotherapy in order to discuss the barriers towards statins adherence and new lipid-lowering drugs implementation in Europe.

Identification of Ezetimibe and Pranlukast as Pharmacological Chaperones for the Treatment of the Rare Disease Mucopolysaccharidosis Type IVA

Mucopolysaccharidosis type IVA (MPS IVA) is a rare disease caused by mutations in the gene encoding the lysosomal enzyme N-acetylgalactosamine-6-sulfate sulfatase (GALNS). We report here two GALNS pharmacological chaperones, ezetimibe and pranlukast, identified by molecular docking-based virtual screening. These compounds bound to the active cavity of GALNS and increased its thermal stability as well as the production of recombinant GALNS in bacteria, yeast, and HEK293 cells. MPS IVA fibroblasts treated with these chaperones exhibited increases in GALNS protein and enzyme activity and reduced the size of enlarged lysosomes. Abnormalities in autophagy markers p62 and LC3B-II were alleviated by ezetimibe and pranlukast. Combined treatment of recombinant GALNS with ezetimibe or pranlukast produced an additive effect. Altogether, the results demonstrate that ezetimibe and pranlukast can increase the yield of recombinant GALNS and be used as a monotherapy or combination therapy to improve the therapeutic efficacy of MPS IVA enzyme replacement therapy.

Current pharmacotherapeutic options for primary dyslipidemia in adults

INTRODUCTION

Atherosclerotic cardiovascular disease (ASCVD) and its clinical manifestations, remain a leading cause of death and disability worldwide. One of the major risk factors of ASCVD is dyslipidemia and all the available guidelines suggest the importance of strategies for lipid control in a remarkable proportion of the general population.

AREAS COVERED

This review focuses on the therapeutic options available for the management of lipid disorders in adults.

EXPERT OPINION

A large body of evidence supports that statins are still the first-line option for the management of hypercholesterolemia in a large percentage of patients. Statins should be given at the appropriate dose and considering the differences in lipid-lowering potency across the different medications. The main current challenge in the treatment of lipid disorders is the need of improving patient adherence and persistence to lipid-lowering treatments beyond the drug choice and the target lipid component. To achieve this goal, the best strategy would be to treat the patients by using the appropriate drugs given at adequate doses to reach the treatment target. We should also avoid drug interactions, monitor possible untoward side effects and promote adherence to treatment by tailoring treatment strategies to each patient.

Emerging drugs for the treatment of hypercholesterolemia

INTRODUCTION

Despite the consolidated role of statins and ezetimibe to treat hypercholesterolemia, often the desirable low-density lipoprotein cholesterol (LDL-C) values are not achieved, with a consequent increase of the residual cardiovascular (CV) risk. Areas covered: In this review, we summarize the main pharmacological characteristics of new lipid-lowering drugs, such as proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, cholesteryl ester transfer protein inhibitors, microsomal triglyceride transfer protein inhibitors, ATP citrate lyase inhibitors, antisense oligonucleotides, small interfering RNA, and peroxisome proliferator-activated receptors type α agonists. The available clinical evidence of efficacy and safety as well as the prospects of application, based on the different mechanisms and targets of action, is critically discussed. Expert opinion: Some of these emerging agents represent an excellent therapeutic strategy to treat patients with LDL largely out of target, resistant or intolerant to statins, trying to minimize the residual CV risk, modulating different classes of lipoproteins, not just LDL. The main challenge for the large use of emerging drugs is their cost. Thus, the correct identification of the adequate target population for treatment is a priority. This is particularly true for safe, powerful, and fully developed drugs such as the PCSK9 inhibitors, for which a relatively large use is potentially expected.

Lipids: a personal view of the past decade

The past decade has witnessed considerable progress in the field of lipids. New drugs have been "rapidly" developed and some of these drugs have already been evaluated in event-based large trials. This evidence has led to the guidelines recommending new, more aggressive treatment goals for low-density lipoprotein cholesterol (LDL-C) levels. Although LDL-C remains the principal goal for cardiovascular disease (CVD) risk reduction, there has also been considerable interest in other lipid variables, such as high-density lipoprotein cholesterol, triglycerides, and lipoprotein(a). Statin intolerance is now considered a very important topic in daily clinical practice. This has resulted in more attention focusing on non-statin drugs [e.g., ezetimibe and proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitors] and statin-related side effects. The latter mainly involve muscles, but there is also a need to consider other adverse effects associated with statin use (e.g., new onset diabetes). New specific areas of statin use have attracted interest. For example, statin-loading before procedures (e.g., coronary stenting), the prevention of stroke, and the treatment of non-alcoholic fatty liver disease (NAFLD). Statins will remain the most widely used drugs to treat dyslipidaemia and decrease CVD risk. However, we also need to briefly consider some other lipid-lowering drugs, including those that may become available in the future.

Lipid-Lowering Effects of Medium-Chain Triglyceride-Enriched Coconut Oil in Combination with Licorice Extracts in Experimental Hyperlipidemic Mice

Coconut oil has gained in popularity over recent years as a healthy oil due to its potential cardiovascular benefits. Coconut oil contains medium chain triglycerides (MCT) including lauric acid and capric acid that display beneficial properties in human health. Licorice ( Glycyrrhiza uralensis) is used as a sweetener and in traditional Chinese medicine with anti-inflammatory, antimicrobial, and antioxidant activities. This study investigated the in vivo effects of medium chain-triglycerides (MCT)-coconut oil (MCO) and its combination with licorice extract (LE-MCO) on serum lipid profile, hepatic steatosis, and local fat pad proteins in diet-induced obese mice. No liver toxicity was observed in 45% fat diet (HFD)-fed mice orally treated with LE, MCO, and LE-MCO for 12 weeks. Their supplementation reduced HFD-enhanced body weight, blood glucose, and insulin in mice. Plasma levels of both PLTP and LCAT were boosted in LE-MCO-administered mice. Supplementation of LE-MCO diminished plasma levels of TG and TC with concomitant reduction of the LDL-C level and tended to raise blood HDL-C level compared to that of HFD alone-mice. Treatment of LE-MCO encumbered the hepatic induction of hepatosteatosis-related proteins of SREBP2, SREBP1c, FAS, ACC, and CD36 in HFD-fed mice. Substantial suppression of this induction was also observed in the liver of mice treated with MCO. Oral administration of LE-MCO to HFD mice boosted hepatic activation of AMPK and the induction of UCP-1 and FATP1 in brown fat. Conversely, LE-MCO disturbed hepatic PPAR-LXR-RXR signaling in HFD-fed animals and reversed HFD-elevated epididymal PPARγ. Collectively, oral administration of LE-MCO may impede hyperlipidemia and hepatosteatosis through curtailing hepatic lipid synthesis.

Pharmacokinetic alterations in poloxamer 407-induced hyperlipidemic rats

1. Plasma lipid profile abnormalities in hyperlipidemia can potentially alter the pharmacokinetics of a drug in a complex manner. To evaluate these pharmacokinetic alterations in hyperlipidemia and to determine the underlying mechanism(s), poloxamer 407-induced hyperlipidemic rats (HL rats), a well-established animal model of hyperlipidemia have been used. 2. In this review, we summarize findings on the pathophysiological and gene expression changes in drug-metabolizing enzymes and transporters in HL rats. We discuss pharmacokinetic changes in drugs metabolized primarily via hepatic cytochrome P450 (CYPs) in terms of alterations in hepatic intrinsic clearance (CL^'_int), free fraction in plasma (f_u) and hepatic blood flow rate (Q_H), depending on the hepatic excretion ratio, as well as drugs eliminated primarily by mechanisms other than hepatic CYPs. 3. For lipoprotein-bound drugs, increased binding to lipoproteins resulted in lower f_u values and volumes of distribution, with some exceptions. Generally, slower non-renal clearance (or total body clearance) of drugs that are substrates of hepatic CYP3A and CYP2C is well explained by the following factors: alterations in CL^'_int (due to down-regulation of hepatic CYPs), decreased f_u and/or possible decreased Q_H. 4. These consistent findings across studies in HL rats suggest more studies are needed at the clinical level for optimal pharmacotherapies for hyperlipidemia.