Maximizing the benefits of cholesterol-lowering drugs

New Insights Into the Treatment of Hyperlipidemia: Pharmacological Updates and Emerging Treatments

Cardiovascular diseases are the leading causes of global mortality and morbidity. Hyperlipidemia is a significant risk factor for atherosclerosis and subsequent cardiovascular diseases. Hyperlipidemia is characterized by imbalances in blood cholesterol levels, particularly elevated low-density lipoprotein cholesterol and triglycerides, and is influenced by genetic and environmental factors. Current management consists of lifestyle modifications and pharmacological interventions most commonly consisting of statins. This review paper explores pathophysiology, management strategies, and pharmacotherapies including commonly used well-established medications including statins, fibrates, and ezetimibe, exciting novel therapies including proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, and RNA interference therapies (inclisiran), lomitapide, and bempedoic acid, highlighting their mechanisms of action, clinical efficacy, and safety profiles. Additionally, emerging therapies under clinical trials including ApoC-III inhibitors, DGAT2 inhibitors, ACAT2 Inhibitors, and LPL gene therapies are examined for their potential to improve lipid homeostasis and cardiovascular outcomes. The evolving landscape of hyperlipidemia management underscores the importance of continued research into both established therapies and promising new candidates, offering hope for more effective treatment strategies in the future.

In Silico Characterization of Withania coagulans Bioactive Compounds as Potential Inhibitors of Hydroxymethylglutaryl (HMG-CoA) Reductase of Mus musculus

Hypercholesterolemia is a mediator for the etiology of cardiovascular diseases, which are characterized as the global leading cause of mortality. We aimed to investigate the inhibitory activity of Withania coagulans compounds against 3-hydroxy-3-methylglutaryl-coenzyme A reductase (Hmgcr) of Mus musculus using an extensive in silico approach. The 3D structure of the Hmgcr protein is not yet known, so we performed the homology modeling using MODELLER and SWISS-MODEL tools, followed with structural validation and assessment. The PROCHECK web server showed that the top-ranked homology model from SWISS-MODEL has 93.4% of residues in the most-favorable region, the quality factor was 98%, and the Verify3D score was 91.43%, compared to the other generated models. The druggable protein-binding cavities in a 3D model of Hmgcr were investigated with the aid of commonly prescribed statin compounds using the CB-dock approach. We compiled a 3D compound library of W. coagulans, followed by drug-likeness evaluation, and found 20 eligible compounds. The pattern of consensus residues obtained from the CB-dock procedure was then used for grid-box docking of W. coagulans compounds and statin drugs using AutoDock 4.2, respectively. The results showed that withanolide R (-10.77 kcal/mol), withanolide Q (-10.56 kcal/mol), withanolide J (-10.52 kcal/mol), atorvastatin (-8.99 kcal/mol), simvastatin (-8.66 kcal/mol), and rosuvastatin (-8.58 kcal/mol) were promising candidates that bind Hmgcr protein. The key residues involved in protein-ligand (withanolide R) interactions were Y516, C526, V529, I530, M533, I535, and V537, and the formation of a H-bond was at C526, M533, and I535 residues. M533 was the consensus residue having a tendency to form a H-bond with withanolide Q, too. Molecular dynamics simulations were used to validate the top-ranked docked complexes for the stability of the modeled protein. We also predicted the pharmacokinetic properties of binding affinity-based top-ranked compounds and concluded that they could be used as potential inhibitors of Hmgcr. However, further in vitro and in vivo studies are essential to completing the drug development process.

A Modern Approach to Dyslipidemia

Lipid disorders involving derangements in serum cholesterol, triglycerides, or both are commonly encountered in clinical practice and often have implications for cardiovascular risk and overall health. Recent advances in knowledge, recommendations, and treatment options have necessitated an updated approach to these disorders. Older classification schemes have outlived their usefulness, yielding to an approach based on the primary lipid disturbance identified on a routine lipid panel as a practical starting point. Although monogenic dyslipidemias exist and are important to identify, most individuals with lipid disorders have polygenic predisposition, often in the context of secondary factors such as obesity and type 2 diabetes. With regard to cardiovascular disease, elevated low-density lipoprotein cholesterol is essentially causal, and clinical practice guidelines worldwide have recommended treatment thresholds and targets for this variable. Furthermore, recent studies have established elevated triglycerides as a cardiovascular risk factor, whereas depressed high-density lipoprotein cholesterol now appears less contributory than was previously believed. An updated approach to diagnosis and risk assessment may include measurement of secondary lipid variables such as apolipoprotein B and lipoprotein(a), together with selective use of genetic testing to diagnose rare monogenic dyslipidemias such as familial hypercholesterolemia or familial chylomicronemia syndrome. The ongoing development of new agents-especially antisense RNA and monoclonal antibodies-targeting dyslipidemias will provide additional management options, which in turn motivates discussion on how best to incorporate them into current treatment algorithms.

Lipid-Modifying Therapies and Stroke Prevention

PURPOSE OF REVIEW

We reviewed lipid-modifying therapies and the risk of stroke and other cerebrovascular outcomes, with a focus on newer therapies.

RECENT FINDINGS

Statins and ezetimibe reduce ischemic stroke risk without increasing hemorrhagic stroke risk. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors similarly reduce ischemic stroke risk in statin-treated patients with atherosclerosis without increasing hemorrhagic stroke, even with very low achieved low-density lipoprotein cholesterol levels. Icosapent ethyl reduces the risk of total and first ischemic stroke in patients with established cardiovascular disease or diabetes mellitus. Clinical outcome trials are underway for newer lipid-modifying agents, including inclisiran, bempedoic acid, and pemafibrate. New biologic agents including evinacumab, pelacarsen, olpasiran, and SLN360 are also discussed. In addition to statins and ezetimibe, PCSK9 inhibitors and icosapent ethyl reduce the risk of ischemic stroke without increasing the risk of hemorrhagic stroke. These therapies dramatically expand options for reducing stroke in high-risk settings.

The Role of Lipid Rafts and Membrane Androgen Receptors in Androgen’s Neurotoxic Effects

Sex differences have been observed in multiple oxidative stress–associated neurodegenerative diseases. Androgens, such as testosterone, can exacerbate oxidative stress through a membrane androgen receptor (mAR), AR45, localized to lipid rafts in the plasma membrane. The goal of this study is to determine if interfering with mAR localization to cholesterol-rich lipid rafts decreases androgen induced neurotoxicity under oxidative stress environments. We hypothesize that cholesterol-rich caveolar lipid rafts are necessary for androgens to induce oxidative stress generation in neurons via the mAR localized within the plasma membrane. Nystatin was used to sequester cholesterol and thus decrease cholesterol-rich caveolar lipid rafts in a neuronal cell line (N27 cells). Nystatin was applied prior to testosterone exposure in oxidatively stressed N27 cells. Cell viability, endocytosis, and protein analysis of oxidative stress, apoptosis, and mAR localization were conducted. Our results show that the loss of lipid rafts via cholesterol sequestering blocked androgen-induced oxidative stress in cells by decreasing the localization of mAR to caveolar lipid rafts.

Cholesterol Metabolism in Chronic Kidney Disease: Physiology, Pathologic Mechanisms, and Treatment

High plasma levels of lipids and/or lipoproteins are risk factors for atherosclerosis, nonalcoholic fatty liver disease (NAFLD), obesity, and diabetes. These four conditions have also been identified as risk factors leading to the development of chronic kidney disease (CKD). Although many pathways that generate high plasma levels of these factors have been identified, most clinical and physiologic dysfunction results from aberrant assembly and secretion of lipoproteins. The results of several published studies suggest that elevated levels of low-density lipoprotein (LDL)-cholesterol are a risk factor for atherosclerosis, myocardial infarction, coronary artery calcification associated with type 2 diabetes, and NAFLD. Cholesterol metabolism has also been identified as an important pathway contributing to the development of CKD; clinical treatments designed to alter various steps of the cholesterol synthesis and metabolism pathway are currently under study. Cholesterol synthesis and catabolism contribute to a multistep process with pathways that are regulated at the cellular level in renal tissue. Cholesterol metabolism may also be regulated by the balance between the influx and efflux of cholesterol molecules that are capable of crossing the membrane of renal proximal tubular epithelial cells and podocytes. Cellular accumulation of cholesterol can result in lipotoxicity and ultimately kidney dysfunction and failure. Thus, further research focused on cholesterol metabolism pathways will be necessary to improve our understanding of the impact of cholesterol restriction, which is currently a primary intervention recommended for patients with dyslipidemia.

Attainment of low-density lipoprotein cholesterol goals in statin treated patients: real-world evidence from Australia

OBJECTIVE

Little is known about the attainment of low-density lipoprotein cholesterol (LDL-C) targets in patients treated with statins in Australian primary healthcare setting that are at increased risk of cardiovascular disease.

METHODS

A retrospective cohort study was conducted using data from electronic medical records of patients treated by general practitioners across Australia. LDL-C target attainment was defined as LDL-C levels ≤ 2 mmol/L for all risk groups, in line with Australian guidelines. Multivariable logistic regression was used to identify the factors associated with LDL-C target attainment.

RESULTS

Overall, 61,407 patients were included in the analysis. The mean age was 65 years (± standard deviation [SD] 12.1); 52.0% were males.. Overall, the median LDL-C level was 2.3 mmol/L (IQR = 1.8 - 2.8) and 36.0% of the study population met therapeutic targets. Increased likelihood to achieve LDL-C targets was observed in patients diagnosed with type 2 diabetes (OR 2.07, 95% CI 1.92 - 2.24), stroke (OR = 1.58, 95% CI 1.39 - 1.79, p< 0.001) or chronic heart disease (OR = 1.67, 95% CI 1.55 - 1.81, p<0.001). Patients diagnosed with dyslipidaemia (OR = 0.59, 95% CI 0.55 - 0.64, p < 0.001), hypertension (OR = 0.91, 95% CI 0.83 - 1.00, p< 0.05) and current smokers (OR = 0.71, 95% CI 0.71 - 1.00, p <0.05), were less likely to attain LDL-C targets, regardless of the type, intensity and length of use of the prescribed statin.

CONCLUSION

Longer duration and higher intensity statin were associated with more patients achieving targeted LDL-C goal, however nearly two thirds of Australians still failed to achieve targeted outcome even after 24 months of statin therapy.

MiR-337-3p lowers serum LDL-C level through targeting PCSK9 in hyperlipidemic mice

BACKGROUND

Reducing serum low-density lipoprotein cholesterol (LDL-C) in hyperlipemia is recognized as an effective strategy to minimize the risk of atherosclerotic cardiovascular disease (ASCVD). MiR-337-3p has already been discovered to play regulatory roles in tumor proliferation and metastasis, adipocyte browning and ischemic brain injury, etc. However, the association between miR-337-3p and LDL-C is unknown.

METHODS

Gene Expression Omnibus (GEO) dataset and two hyperlipidemic murine models were used to analyze the potential relationship between miR-337-3p and LDL-C. AAV-mediated liver-directed miRNA overexpression in high fat diet (HFD)-fed mouse model was used to examine the effect of miR-337-3p on LDL-C and WB/RT-PCR/ELISA/luciferase assays were used to investigate the underlying mechanism.

RESULTS

The expressions of miR-337-3p were obviously lower in multiple hyperlipidemic mouse models and had a negative correlation with serum LDL-C levels. After confirming the effect of miR-337-3p on the improvement of serum LDL-C in vivo, we discovered PCSK9 might be a possible target of miR-337-3p, which was further proved by in vitro experiments. MiR-337-3p could directly interact with both the PCSK9 3'UTR and promoter to inhibit PCSK9 translation and transcription. Furthermore, the result from DiI-LDL uptake assay under the knockdown of PCSK9 demonstrated that miR-337-3p promoting the absorption of LDL-C in HepG2 cells was dependent on PCSK9, and the result from LDLR-/- mouse model indicated that miR-337-3p regulating LDL-C was dependent on PCSK9/LDLR pathway.

CONCLUSION

We discovered a new function of miR-337-3p in regulating PCSK9 expression and LDL-C absorption, suggesting miR-337-3p might be a new therapeutic target for the development of antihyperlipidemic drug.