Angiopoietin-Like Protein 3 (ANGPTL3) Modulates Lipoprotein Metabolism and Dyslipidemia

Single-nucleus transcriptome reveals cell dynamic response of liver during the late chick embryonic development

The late embryonic development of the liver, a major metabolic organ, remains poorly characterized at single cell resolution. Here, we used single-nucleus RNA-sequencing (snRNA-seq) to characterize the chicken liver cells at 2 embryonic development time points (E14 and D1). We uncovered 8 cell types including hepatocytes, endothelial cells, hepatic stellate cells, erythrocytes, cholangiocytes, kupffer cells, mesothelial cells, and lymphocytes. And we discovered significant differences in the abundance of different cell types between E14 and D1. Moreover, we characterized the heterogeneity of hepatocytes, endothelial cells, and mesenchymal cells based on the gene regulatory networks of each clusters. Trajectory analyses revealed 128 genes associated with hepatocyte development and function, including apolipoprotein genes involved hepatic lipid metabolism and NADH dehydrogenase subunits involved hepatic oxidative phosphorylation. Furthermore, we identified the differentially expressed genes (DEGs) between E14 and D1 at the cellular levels, which contribute to changes in liver development and function. These DEGs were significantly enriched in PPAR signaling pathways and lipid metabolism related pathways. Our results presented the single-cell mapping of chick embryonic liver at late stages of development and demonstrated the metabolic changes across the 2 age stages at the cellular level, which can help to further study the molecular development mechanism of embryonic liver.

Emerging Trends and Innovations in the Treatment and Diagnosis of Atherosclerosis and Cardiovascular Disease: A Comprehensive Review towards Healthier Aging

Cardiovascular diseases (CVDs) are classed as diseases of aging, which are associated with an increased prevalence of atherosclerotic lesion formation caused by such diseases and is considered as one of the leading causes of death globally, representing a severe health crisis affecting the heart and blood vessels. Atherosclerosis is described as a chronic condition that can lead to myocardial infarction, ischemic cardiomyopathy, stroke, and peripheral arterial disease and to date, most pharmacological therapies mainly aim to control risk factors in patients with cardiovascular disease. Advances in transformative therapies and imaging diagnostics agents could shape the clinical applications of such approaches, including nanomedicine, biomaterials, immunotherapy, cell therapy, and gene therapy, which are emerging and likely to significantly impact CVD management in the coming decade. This review summarizes the current anti-atherosclerotic therapies' major milestones, strengths, and limitations. It provides an overview of the recent discoveries and emerging technologies in nanomedicine, cell therapy, and gene and immune therapeutics that can revolutionize CVD clinical practice by steering it toward precision medicine. CVD-related clinical trials and promising pre-clinical strategies that would significantly impact patients with CVD are discussed. Here, we review these recent advances, highlighting key clinical opportunities in the rapidly emerging field of CVD medicine.

Optimization of lipid nanoparticles for gene editing of the liver via intraduodenal delivery

Lipid nanoparticles (LNPs) have recently emerged as successful gene delivery platforms for a diverse array of disease treatments. Efforts to optimize their design for common administration methods such as intravenous injection, intramuscular injection, or inhalation, revolve primarily around the addition of targeting ligands or the choice of ionizable lipid. Here, we employed a multi-step screening method to optimize the type of helper lipid and component ratios in a plasmid DNA (pDNA) LNP library to efficiently deliver pDNA through intraduodenal delivery as an indicative route for oral administration. By addressing different physiological barriers in a stepwise manner, we down-selected effective LNP candidates from a library of over 1000 formulations. Beyond reporter protein expression, we assessed the efficiency in non-viral gene editing in mouse liver mediated by LNPs to knockdown PCSK9 and ANGPTL3 expression, thereby lowering low-density lipoprotein (LDL) cholesterol levels. Utilizing an all-in-one pDNA construct with Strep. pyogenes Cas9 and gRNAs, our results showcased that intraduodenal administration of selected LNPs facilitated targeted gene knockdown in the liver, resulting in a 27% reduction in the serum LDL cholesterol level. This LNP-based all-in-one pDNA-mediated gene editing strategy highlights its potential as an oral therapeutic approach for hypercholesterolemia, opening up new possibilities for DNA-based gene medicine applications.

Dyslipidemia and ANGPTL8 evaluation in young females with Type 1 diabetes mellitus

PURPOSE

ANGPTL8, commonly referred to as betatrophin, has demonstrated promise as a dependable marker for the onset of complications associated with diabetes mellitus, such as dyslipidemia. The objective of this study is to evaluate the lipid profile and ANGPTL8 levels in people diagnosed with Type 1 Diabetes Mellitus (T1DM).

METHODS

A retrospective case-control study was performed on a group of 100 adolescent females, aged 13-17 years. This group consisted of individuals diagnosed with T1DM from the Diabetes and Endocrine Department at Medina's King Fahad Hospital in Saudi Arabia. Additionally, 100 healthy adolescent females of the same age range were included as controls. The hospital conducted laboratory studies to evaluate glucose, HbA1c, insulin, and lipid profiles. The ANGPTL8 levels were quantified using Enzyme-Linked Immunosorbent Assay (ELISA).

RESULTS

Patients with T1DM had ANGPTL8 levels that were twice as high as those observed in individuals without any health conditions. The two groups had contrasting levels of fasting blood glucose (FBG), glycated hemoglobin (HbA1c), C-peptides, triacylglycerol (TG), and cholesterol, along with elevated Atherogenic Index of Plasma readings. Diabetes mellitus patients had considerably elevated values compared to the control group. There was a significant correlation between ANGPTL8 concentrations and lipid abnormalities, with P-values less than 0.05. 56% of the 100 patients exhibited dyslipidemia. The research found a correlation between dyslipidemia and elevated levels of ANGPTL8 in diabetic patients. The concentration of ANGPTL8 had a positive correlation with glucose, HbA1c, TG, and C-peptides while displaying a negative correlation with high-density lipoprotein cholesterol (HDL-C).

CONCLUSION

ANGPTL8 levels were found to be elevated in Saudi young women who were diagnosed with TIDM. ANGPTL8 may potentially contribute to dyslipidemia in individuals with T1DM, hence increasing the susceptibility to cardiovascular disease (CVD). Therefore, ANGPTL8 has the potential to impact lipid metabolism, namely Triglycerides, as a biological route. The results highlight the need to analyze lipid profiles and do ANGPTL8 testing in young females diagnosed with T1DM at an early stage to prevent complications.

Triglyceride-rich lipoproteins and cardiovascular diseases

The global prevalence of cardiovascular diseases (CVD) continues to rise steadily, making it a leading cause of mortality worldwide. Atherosclerosis (AS) serves as a primary driver of these conditions, commencing silently at an early age and culminating in adverse cardiovascular events that severely impact patients' quality of life or lead to fatality. Dyslipidemia, particularly elevated levels of low-density lipoprotein cholesterol (LDL-C), plays a pivotal role in AS pathogenesis as an independent risk factor. Research indicates that abnormal LDL-C accumulation within arterial walls acts as a crucial trigger for atherosclerotic plaque formation. As the disease progresses, plaque accumulation may rupture or dislodge, resulting in thrombus formation and complete blood supply obstruction, ultimately causing myocardial infarction, cerebral infarction, and other common adverse cardiovascular events. Despite adequate pharmacologic therapy targeting LDL-C reduction, patients with cardiometabolic abnormalities remain at high risk for disease recurrence, highlighting the importance of addressing lipid risk factors beyond LDL-C. Recent attention has focused on the causal relationship between triglycerides, triglyceride-rich lipoproteins (TRLs), and their remnants in AS risk. Genetic, epidemiologic, and clinical studies suggest a causal relationship between TRLs and their remnants and the increased risk of AS, and this dyslipidemia may be an independent risk factor for adverse cardiovascular events. Particularly in patients with obesity, metabolic syndrome, diabetes, and chronic kidney disease, disordered TRLs and its remnants levels significantly increase the risk of atherosclerosis and cardiovascular disease development. Accumulation of over-synthesized TRLs in plasma, impaired function of enzymes involved in TRLs lipolysis, and impaired hepatic clearance of cholesterol-rich TRLs remnants can lead to arterial deposition of TRLs and its remnants, promoting foam cell formation and arterial wall inflammation. Therefore, understanding the pathogenesis of TRLs-induced AS and targeting it therapeutically could slow or impede AS progression, thereby reducing cardiovascular disease morbidity and mortality, particularly coronary atherosclerotic heart disease.

Xanthohumol, a prenylated chalcone, regulates lipid metabolism by modulating the LXRα/RXR-ANGPTL3-LPL axis in hepatic cell lines and high-fat diet-fed zebrafish models

Angiopoietin-like 3 (ANGPTL3) acts as an inhibitor of lipoprotein lipase (LPL), impeding the breakdown of triglyceride-rich lipoproteins (TGRLs) in circulation. Targeting ANGPTL3 is considered a novel strategy for improving dyslipidemia and atherosclerotic cardiovascular diseases (ASCVD). Hops (Humulus lupulus L.) contain several bioactive prenylflavonoids, including xanthohumol (Xan), isoxanthohumol (Isoxan), 6-prenylnaringenin (6-PN), and 8-prenylnaringenin (8-PN), with the potential to manage lipid metabolism. The aim of this study was to investigate the lipid-lowering effects of Xan, the effective prenylated chalcone in attenuating ANGPTL3 transcriptional activity, both in vitro using hepatic cells and in vivo using zebrafish models, along with exploring the underlying mechanisms. Xan (10 and 20 μM) significantly reduced ANGPTL3 mRNA and protein expression in HepG2 and Huh7 cells, leading to a marked decrease in secreted ANGPTL3 proteins via hepatic cells. In animal studies, orally administered Xan significantly alleviated plasma triglyceride (TG) and cholesterol levels in zebrafish fed a high-fat diet. Furthermore, it reduced hepatic ANGPTL3 protein levels and increased LPL activity in zebrafish models, indicating its potential to modulate lipid profiles in circulation. Furthermore, molecular docking results predicted that Xan exhibits a higher binding affinity to interact with liver X receptor α (LXRα) and retinoic acid X receptor (RXR) than their respective agonists, T0901317 and 9-Cis-retinoic acid (9-Cis-RA). We observed that Xan suppressed hepatic ANGPTL3 expression by antagonizing the LXRα/RXR-mediated transcription. These findings suggest that Xan ameliorates dyslipidemia by modulating the LXRα/RXR-ANGPTL3-LPL axis. Xan represents a novel potential inhibitor of ANGPTL3 for the prevention or treatment of ASCVD.

The Essence of Lipoproteins in Cardiovascular Health and Diseases Treated by Photodynamic Therapy

Lipids, together with lipoprotein particles, are the cause of atherosclerosis, which is a pathology of the cardiovascular system. In addition, it affects inflammatory processes and affects the vessels and heart. In pharmaceutical answer to this, statins are considered a first-stage treatment method to block cholesterol synthesis. Many times, additional drugs are also used with this method to lower lipid concentrations in order to achieve certain values of low-density lipoprotein (LDL) cholesterol. Recent advances in photodynamic therapy (PDT) as a new cancer treatment have gained the therapy much attention as a minimally invasive and highly selective method. Photodynamic therapy has been proven more effective than chemotherapy, radiotherapy, and immunotherapy alone in numerous studies. Consequently, photodynamic therapy research has expanded in many fields of medicine due to its increased therapeutic effects and reduced side effects. Currently, PDT is the most commonly used therapy for treating age-related macular degeneration, as well as inflammatory diseases, and skin infections. The effectiveness of photodynamic therapy against a number of pathogens has also been demonstrated in various studies. Also, PDT has been used in the treatment of cardiovascular diseases, such as atherosclerosis and hyperplasia of the arterial intima. This review evaluates the effectiveness and usefulness of photodynamic therapy in cardiovascular diseases. According to the analysis, photodynamic therapy is a promising approach for treating cardiovascular diseases and may lead to new clinical trials and management standards. Our review addresses the used therapeutic strategies and also describes new therapeutic strategies to reduce the cardiovascular burden that is induced by lipids.

Association of a genetic variant in angiopoietin-like 3 with serum HDL-C and risk of cardiovascular disease: A study of the MASHAD cohort over 6 years

BACKGROUND

Loss-of-function (LOF) variants of the angiopoietin-like 3 (ANGPTL3) gene are reported to be associated with serum triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) concentrations and thereby affect the risk of cardiovascular disease (CVD).

OBJECTIVE

In the present study, we examined the association of rs10789117 in the ANGPTL 3 gene locus and the risk of CVD in the group of people who were part of the Mashhad-Stroke and Heart-Atherosclerotic-Disorders (MASHAD) cohort.

METHODS

One thousand and two healthy individuals enrolled in this study of whom 849 subjects were healthy and 153 subjects developed CVD outcomes after 6 years of follow-up. After a 12-h overnight fasting, 20 mL of blood samples were collected for the measurement of fasting blood glucose and lipid profile. DNA was extracted, and the Tetra-ARMS PCR (amplification refractory mutation system) was used for genotyping of rs10789117 in the ANGPTL3 gene. The genotype frequencies of the variant of rs10789117 in the ANGPTL3 gene were estimated using χ2 tests. Eventually, the statistical analysis was done by SPSS version 20.

RESULTS

Individuals with AC/CC genotypes (rs10789117) were found to have to greater risk of CVD events compared to AA genotype (OR = 1.43, 95%CI = 1.01-2.02, p = 0.041). There was a 1.3-fold increase in cardiovascular events in individuals carrying the C allele of rs10789117 variant compared to non-carriers (OR = 1.32, 95%CI = 1.06-1.72, p value = 0.038). There were significant differences between different genotypes for serum triglyceride levels within the control group, but this difference was not significant in the group with CVD. Moreover, there was a significant association between CC genotype and CVD risk in the individuals with a normal serum HDL-C.

CONCLUSION

We have found that a rs10789117 C>A in ANGPTL3 gene polymorphism was associated with incident CVD events, and this may be of value as a risk stratification biomarker in CVD in the Iranian population.

The Effect of Canagliflozin on High-Density Lipoprotein Cholesterol and Angiopoietin-Like Protein 3 in Type 2 Diabetes Mellitus

Background

Diabetes mellitus is often accompanied by dyslipidemia. Sodium-glucose cotransporter-2 (SGLT2) inhibitors, as a novel therapeutic agent for the treatment of type 2 diabetes mellitus (T2DM), have been reported to exert effects on lipid, while the results remain controversial. This study is aimed at exploring the effect of SGLT2 inhibitor canagliflozin on lipid profile.

Methods

This study was a single-center, open-label, nonrandomized, prospective study. Metformin (500 mg three times per day) or canagliflozin (100 mg, once daily) was administered for 12 weeks. Fasting blood samples were collected before and 12 weeks after treatment. Serum lipid profile levels and angiopoietin-like protein 3 (ANGPTL3) were determined. In animal experiment, C57BL/6 J mice were divided into three groups including control, STZ + HFD, and STZ + HFD + canagliflozin. Lipid profile and plasma ANGPTL3 level were measured after 12 week's treatment. Moreover, the expression of ANGPTL3 was detected in the liver tissues.

Results

There was a decreased trend in low-density lipoprotein cholesterol (LDL-c) and triglycerides (TG) after canagliflozin treatment, while canagliflozin significantly increased high-density lipoprotein cholesterol (HDL-c) level and decreased plasma ANGPTL3 level. In addition, the expression of ANGPTL3 in liver tissues decreased obviously in diabetic mice with canagliflozin treatment.

Conclusions

Canagliflozin increases HDL-c level and suppresses ANGPTL3 expression in patients with T2DM and diabetic mice. The reduction of ANGPTL3 may contribute to the increase of HDL-c. However, the specific mechanism needs further research. This trial is registered with ChiCTR1900021231.

Tailoring Treatment in Cardiovascular Diseases: The Role of Targeted Therapies

Cardiovascular diseases (CVDs) remain the leading cause of morbidity and mortality around the globe. To address this public health burden, innovative therapeutic agents are being developed to specifically target molecular and genetic markers. Various therapeutic modalities have been implemented, including vaccines, monoclonal or bispecific antibodies, and gene-based therapies. Such drugs precisely target the underlying disease pathophysiology, aiming at notable molecules such as lipid metabolism regulators, proinflammatory cytokines, and growth factors. This review focuses on the latest advancements in different targeted therapies. It provides an insightful overview of the current landscape of targeted cardiovascular therapies, highlighting promising strategies with potential to transform the treatment of CVDs into an era of precision medicine.

ANGPTL3 is a novel HDL component that regulates HDL function

BACKGROUND

Angiopoietin-like protein 3 (ANGPTL3) is secreted by hepatocytes and inhibits lipoprotein lipase and endothelial lipase activity. Previous studies reported the correlation between plasma ANGPTL3 levels and high-density lipoprotein (HDL). Recently ANGPTL3 was found to preferentially bind to HDL in healthy human circulation. Here, we examined whether ANGPTL3, as a component of HDL, modulates HDL function and affects HDL other components in human and mice with non-diabetes or type 2 diabetes mellitus.

METHODS

HDL was isolated from the plasma of female non-diabetic subjects and type-2 diabetic mellitus (T2DM) patients. Immunoprecipitation, western blot, and ELISA assays were used to examine ANGPTL3 levels in HDL. Db/m and db/db mice, AAV virus mediated ANGPTL3 overexpression and knockdown models and ANGPTL3 knockout mice were used. The cholesterol efflux capacity induced by HDL was analyzed in macrophages preloaded with fluorescent cholesterol. The anti-inflammation capacity of HDL was assessed using flow cytometry to measure VCAM-1 and ICAM-1 expression levels in TNF-α-stimulated endothelial cells pretreated with HDL.

RESULTS

ANGPTL3 was found to bind to HDL and be a component of HDL in both non-diabetic subjects and T2DM patients. Flag-ANGPTL3 was found in the HDL of transgenic mice overexpressing Flag-ANGPTL3. ANGPLT3 of HDL was positively associated with cholesterol efflux in female non-diabetic controls (r = 0.4102, p = 0.0117) but not in female T2DM patients (r = - 0.1725, p = 0.3224). Lower ANGPTL3 levels of HDL were found in diabetic (db/db) mice compared to control (db/m) mice and were associated with reduced cholesterol efflux and inhibition of VCAM-1 and ICAM-1 expression in endothelial cells (p < 0.05 for all). Following AAV-mediated ANGPTL3 cDNA transfer in db/db mice, ANGPTL3 levels were found to be increased in HDL, and corresponded to increased cholesterol efflux and decreased ICAM-1 expression. In contrast, knockdown of ANGPTL3 levels in HDL by AAV-mediated shRNA transfer led to a reduction in HDL function (p < 0.05 for both). Plasma total cholesterol, total triglycerides, HDL-c, protein components of HDL and the cholesterol efflux function of HDL were lower in ANGPTL3-/- mice than ANGPTL3+/+ mice, suggesting that ANGPTL3 in HDL may regulate HDL function by disrupting the balance of protein components in HDL.

CONCLUSION

ANGPTL3 was identified as a component of HDL in humans and mice. ANGPTL3 of HDL regulated cholesterol efflux and the anti-inflammatory functions of HDL in T2DM mice. Both the protein components of HDL and cholesterol efflux capacity of HDL were decreased in ANGPTL3-/- mice. Our findings suggest that ANGPTL3 in HDL may regulate HDL function by disrupting the balance of protein components in HDL. Our study contributes to a more comprehensive understanding of the role of ANGPTL3 in lipid metabolism.

Monoclonal antibodies for dyslipidemia in adults: a focus on vulnerable patients groups

INTRODUCTION

Dyslipidemia significantly contributes to atherosclerotic cardiovascular disease (ASCVD). Patients with lipid-rich vulnerable plaques are particularly susceptible to cardiovascular complications. Despite available lipid-lowering therapies (LLTs), challenges in effective lipid management remain.

AREAS COVERED

This article reviews monoclonal antibody (mAb) therapy in dyslipidemia, particularly focusing on vulnerable plaques and patients. We have reviewed the definitions of vulnerable plaques and patients, outlined the efficacy of traditional LLTs, and discussed in-depth the mAbs targeting PCSK9. We extensively discuss the potential mechanisms, intracoronary imaging, and clinical evidence of PCSK9mAbs in vulnerable plaques and patients. A brief overview of promising mAbs targeting other targets such as ANGPTL3 is also provided.

EXPERT OPINION

Research consistently supports the potential of mAb therapies in treating adult dyslipidemia, particularly in vulnerable patients. PCSK9mAbs are effective in regulating lipid parameters, such as LDL-C and Lp(a), and exhibit anti-inflammatory and anti-thrombotic properties. These antibodies also maintain endothelial and smooth muscle health, contributing to the stabilization of vulnerable plaques and reduction in adverse cardiovascular events. Future research aims to further understand PCSK9 and other targets like ANGPTL3, focusing on vulnerable groups. Overall, mAbs are emerging as a promising and superior approach in dyslipidemia management and cardiovascular disease prevention.

A novel fully human anti-NT-ANGPTL3 antibody from phage display library exhibits potent ApoB, TG, and LDL-C lowering activities in hyperlipidemia mice

Dyslipidemia is characterized by elevated plasma levels of low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and TG-rich lipoprotein (TGRLs) in circulation, and is closely associated with the incidence and development of cardiovascular disease. Angiopoietin-like protein 3 (ANGPTL3) deficiency has been identified as a cause of familial combined hypolipidemia in humans, which allows it to be an important therapeutic target for reducing plasma lipids. Here, we report the discovery and characterization of a novel fully human antibody F1519-D95aA against N-terminal ANGPTL3 (NT-ANGPTL3), which potently inhibits NT-ANGPTL3 with a KD as low as 9.21 nM. In hyperlipidemic mice, F1519-D95aA shows higher apolipoprotein B (ApoB) and TG-lowering, and similar LDL-C reducing activity as compared to positive control Evinacumab (56.50% vs 26.01% decrease in serum ApoB levels, 30.84% vs 25.28% decrease in serum TG levels, 23.32% vs 22.52% decrease in serum LDLC levels, relative to vehicle group). Molecular docking and binding energy calculations reveal that the F1519-D95aA-ANGPTL3 complex (10 hydrogen bonds, -65.51 kcal/mol) is more stable than the Evinacumab-ANGPTL3 complex (4 hydrogen bonds, -63.76 kcal/mol). Importantly, F1519-D95aA binds to ANGPTL3 with different residues in ANGPTL3 from Evinacumab, suggesting that F1519-D95aA may be useful for the treatment of patients resistant to Evinacumab. In conclusion, F1519-D95aA is a novel fully human anti-NT-ANGPTL3 antibody with potent plasma ApoB, TG, and LDL-C lowering activities, which can potentially serve as a therapeutic agent for hyperlipidemia and relevant cardiovascular diseases.

Advances in Dyslipidaemia Treatments: Focusing on ApoC3 and ANGPTL3 Inhibitors

Apolipoprotein C3 (apoC3) and angiopoietin-like protein 3 (ANGPTL3) inhibit lipolysis by lipoprotein lipase and may influence the secretion and uptake of various lipoproteins. Genetic studies show that depletion of these proteins is associated with improved lipid profiles and reduced cardiovascular events so it was anticipated that drugs which mimic the effects of loss-of-function mutations would be useful lipid treatments. ANGPTL3 inhibitors were initially developed as a treatment for severe hypertriglyceridaemia including familial chylomicronaemia syndrome (FCS), which is usually not adequately controlled with currently available drugs. However, it was found ANGPTL3 inhibitors were also effective in reducing low-density lipoprotein cholesterol (LDL-C) and they were studied in patients with homozygous familial hypercholesterolaemia (FH). Evinacumab targets ANGPTL3 and reduced LDL-C by about 50% in patients with homozygous FH and it has been approved for that indication. The antisense oligonucleotide (ASO) vupanorsen targeting ANGPTL3 was less effective in reducing LDL-C in patients with moderate hypertriglyceridaemia and its development has been discontinued but the small interfering RNA (siRNA) ARO-ANG3 is being investigated in Phase 2 studies. ApoC3 can be inhibited by the ASO volanesorsen, which reduced triglycerides by >70% in patients with FCS and it was approved for FCS in Europe but not in the United States because of concerns about thrombocytopaenia. Olezarsen is an N-acetylgalactosamine-conjugated ASO targeting apoC3 which appears as effective as volanesorsen without the risk of thrombocytopaenia and is undergoing Phase 3 trials. ARO-APOC3 is an siRNA targeting apoC3 that is currently being investigated in Phase 3 studies.

Novel Insights of ANGPTL-3 on Modulating Cholesterol Efflux Capacity Induced by HDL Particle

BACKGROUND

Angiopoietin-like protein 3 (ANGPTL-3) modulates lipid metabolism and the risk of coronary artery disease (CAD), especially stable angina (SA), via suppressing lipoprotein lipase (LPL). However, whether there are other mechanisms is not elucidated yet. The current research explored the modulatory roles of ANGPTL-3 on high-density lipoprotein (HDL), which further affects atherosclerotic development.

METHODS

A total of 200 individuals were enrolled in the present study. Serum ANGPTL- 3 levels were detected via enzyme-linked immunosorbent assays (ELISA). Cholesterol efflux capacity induced by HDL particles was detected through H3-cholesterol loading THP-1 cell.

RESULTS

The serum ANGPTL-3 levels presented no significant discordance between the SA group and the non-SA group, whereas the serum ANGPTL-3 levels in type 2 diabetes mellitus (T2DM) group were significantly elevated compared with those in the non-T2DM group [428.3 (306.2 to 736.8) ng/ml vs. 298.2 (156.8 to 555.6) ng/ml, p <0.05]. Additionally, the serum ANGPTL-3 levels were elevated in patients with low TG levels compared to those in patients with high TG levels [519.9 (377.6 to 809.0) ng/ml vs. 438.7 (329.2 to 681.0) ng/ml, p <0.05]. By comparison, the individuals in the SA group and T2DM group presented decreased cholesterol efflux induced by HDL particles [SA: (12.21±2.11)% vs. (15.51±2.76)%, p <0.05; T2DM: (11.24±2.13)% vs. (14.65± 3.27)%, p <0.05]. In addition, the serum concentrations of ANGPTL-3 were inversely associated with the cholesterol efflux capacity of HDL particles (r=-0.184, p <0.05). Through regression analysis, the serum concentrations of ANGPTL-3 were found to be an independent modulator of the cholesterol efflux capacity of HDL particles (standardized β=-0.172, p <0.05).

CONCLUSION

ANGPTL-3 exhibited a negative modulatory function on cholesterol efflux capacity induced by HDL particles.

Angiopoietin-like 3 inhibition and the liver: less is more?

PURPOSE OF REVIEW

The aim of this study was to discuss the potential mechanisms and implications of the opposing liver safety results from recent angiopoietin-like 3 (ANGPTL3) inhibition studies.

RECENT FINDINGS

The clinical development of vupanorsen, a N-acetylgalactosamine (GalNAc) antisense targeting hepatic ANGPTL3, was recently discontinued due to a significant signal of liver transaminase increase. Vupanorsen elicited a dose-dependent increase in hepatic fat fraction up to 75%, whereas the small interfering RNA (siRNA) ARO-ANG3, has reported preliminary evidence of a dose-dependent decrease in hepatic fat fraction up to 30%.

SUMMARY

ANGPTL3 inhibition is an attractive therapeutic target to reduce all apoB-containing lipoproteins. The discrepancy in liver signal results between the antisense and siRNA approach may be explained by the level of target inhibition. An alternative explanation may relate to off-target effects of vupanorsen, which have a molecule- and/or platform-specific origin. For intrahepatic strategies, highly potent ANGPTL3 inhibition will for now require special attention for liver safety.

Targeting PCSK9 and Beyond for the Management of Low-Density Lipoprotein Cholesterol

Reducing low-density lipoprotein cholesterol (LDL-C) levels is crucial to the prevention of atherosclerotic cardiovascular disease (ASCVD). However, many patients, especially those at very high ASCVD risk or with familial hypercholesterolemia (FH), do not achieve target LDL-C levels with statin monotherapy. The underutilization of novel lipid-lowering therapies (LLT) globally may be due to cost concerns or therapeutic inertia. Emerging approaches have the potential to lower LDL-C and reduce ASCVD risk further, in addition to offering alternatives for statin-intolerant patients. Shifting the treatment paradigm towards initial combination therapy and utilizing novel LLT strategies can complement existing treatments. This review discusses innovative approaches including combination therapies involving statins and agents like ezetimibe, bempedoic acid, cholesterol ester transfer protein (CETP) inhibitors as well as strategies targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) and angiopoietin-like protein 3 (ANGPTL3) inhibition. Advances in nucleic acid-based therapies and gene editing are innovative approaches that will improve patient compliance and adherence. These strategies demonstrate significant LDL-C reductions and improved cardiovascular outcomes, offering potential for optimal LDL-C control and reduced ASCVD risk. By addressing the limitations of statin monotherapy, these approaches provide new management options for elevated LDL-C levels.

Remnant Cholesterol, a Valuable Biomarker for Assessing Arteriosclerosis and Cardiovascular Risk: A Systematic Review

Arteriosclerosis, as the foundation for the development of cardiovascular diseases, is influenced by disturbances in lipid metabolism. Extensive research has consistently shown a correlation between conventional lipid parameters, arteriosclerosis, and cardiovascular diseases. Guidelines highlight the importance of targeting low-density lipoprotein cholesterol (LDL-C) for primary and secondary prevention of cardiovascular diseases, with reducing LDL-C remaining the primary lipid-lowering strategy. However, even when LDL-C is lowered to optimal levels, there is a residual risk of cardiovascular disease. Recent findings have brought attention to remnant cholesterol (RC) as a significant factor contributing to this residual risk. The close association between RC, arteriosclerosis, and cardiovascular diseases presents exciting opportunities for lifestyle interventions and medical treatments to control and lower RC levels, offering new targets for preventing and managing related cardiovascular conditions. Our systematic review sheds light on the importance of considering RC as a valuable biomarker in assessing arteriosclerosis and its potential impact on cardiovascular health. By understanding the link between remnant cholesterol and arteriosclerosis, researchers and healthcare professionals can develop targeted interventions to mitigate cardiovascular risks, thus improving public health outcomes and reducing the economic burden associated with cardiovascular diseases.

A Review of Progress on Targeting LDL Receptor-Dependent and -Independent Pathways for the Treatment of Hypercholesterolemia, a Major Risk Factor of ASCVD

Since the discovery of the LDL receptor in 1973 by Brown and Goldstein as a causative protein in hypercholesterolemia, tremendous amounts of effort have gone into finding ways to manage high LDL cholesterol in familial hypercholesterolemic (HoFH and HeFH) individuals with loss-of-function mutations in the LDL receptor (LDLR) gene. Statins proved to be the first blockbuster drug, helping both HoFH and HeFH individuals by inhibiting the cholesterol synthesis pathway rate-limiting enzyme HMG-CoA reductase and inducing the LDL receptor. However, statins could not achieve the therapeutic goal of LDL. Other therapies targeting LDLR include PCSK9, which lowers LDLR by promoting LDLR degradation. Inducible degrader of LDLR (IDOL) also controls the LDLR protein, but an IDOL-based therapy is yet to be developed. Among the LDLR-independent pathways, such as angiopoietin-like 3 (ANGPTL3), apolipoprotein (apo) B, apoC-III and CETP, only ANGPTL3 offers the advantage of treating both HoFH and HeFH patients and showing relatively better preclinical and clinical efficacy in animal models and hypercholesterolemic individuals, respectively. While loss-of-LDLR-function mutations have been known for decades, gain-of-LDLR-function mutations have recently been identified in some individuals. The new information on gain of LDLR function, together with CRISPR-Cas9 genome/base editing technology to target LDLR and ANGPTL3, offers promise to HoFH and HeFH individuals who are at a higher risk of developing atherosclerotic cardiovascular disease (ASCVD).

Proof-of-concept study for liver-directed miQURE technology in a dyslipidemic mouse model

A gene-silencing platform (miQURE) has been developed and successfully used to deliver therapeutic microRNA (miRNA) to the brain, reducing levels of neurodegenerative disease-causing proteins/RNAs via RNA interference and improving the disease phenotype in animal models. This study evaluates the use of miQURE technology to deliver therapeutic miRNA for liver-specific indications. Angiopoietin-like 3 (ANGPTL3) was selected as the target mRNA because it is produced in the liver and because loss-of-function ANGPTL3 mutations and/or pharmacological inhibition of ANGPTL3 protein lowers lipid levels and reduces cardiovascular risk. Overall, 14 candidate miRNA constructs were tested in vitro, the most potent of which (miAngE) was further evaluated in mice. rAAV5-miAngE led to dose-dependent (≤-77%) decreases in Angptl3 mRNA in WT mice with ≤-90% reductions in plasma ANGPTL3 protein. In dyslipidemic APOE∗3-Leiden.CETP mice, AAV5-miAngE significantly reduced cholesterol and triglyceride levels vs. vehicle and scrambled (miSCR) controls when administrated alone, with greater reductions when co-administered with lipid-lowering therapy (atorvastatin). A significant decrease in total atherosclerotic lesion area (-58% vs. miSCR) was observed in AAV5-miAngE-treated dyslipidemic mice, which corresponded with the maintenance of a non-diseased plaque phenotype and reduced lesion severity. These results support the development of this technology for liver-directed indications.

Elevated angiopoietin-like protein 3 serum levels in diabetic nephropathy patients and its association with renal function and lipid profile

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a highly prevalent disease that has life-threatening consequences like micro and macrovascular complication. Diabetic nephropathy (DN) is one of the common consequences of T2DM which is related to secretory factors like hepatokines. Angiopoietin-Like Protein 3 (ANGPTL3) is a hepatokine that is perturbated in cardiometabolic diseases and experimental studies showed its effect on renal functions and lipid metabolism. For the first time, ANGPTL3 was measured in patients with T2DM and DN in the present study.

METHODS

Serum levels of ANGPTL3, IL-6, and TNF-α were measured in 60 healthy control, 60 T2DM patients, and 61 DN patients.

RESULTS

Serum levels of ANGPTL3 increased in T2DM (252.39 ± 66.01) and DN (284.59 ± 69.27) patients compared to controls (160.22 ± 48.96), and DN patients compared with T2DM patients. Urinary albumin excretion (UAE) was higher in the DN group compared to T2DM and control groups. Moreover, serum levels of IL-6 and TNF-α were elevated in both patient groups compared to controls. Moreover, ANGPTL3 represented a positive correlation with triglycerides, creatinine, and UAE in patients with both T2DM and DN groups and showed an inverse correlation with eGFR in patients with DN. Moreover, this hepatokine had a good potential to differentiate patients from controls, especially, DN patients.

CONCLUSIONS

these findings provide invivo evidence for the relation of ANGPTL3 with renal dysfunction and hypertriglyceridemia in patients with DN which is in line with experimental findings and suggested a potential role for this hepatokine in DN pathogenesis.

Angiopoietin-like protein 3: a novel potential biomarker for nephrotic syndrome in children

Background

Angiopoietin-like 3 (ANGPTL3) is a secretory glycoprotein. It has been demonstrated that ANGPTL3 level was upregulated in minimal change nephrotic syndrome (MCNS) kidney tissues. Subsequently, our group found that ANGPTL3 level was closely correlated with nephropathy in vivo and in vitro. Hence, whether ANGPTL3 level could be correlated with the proteinuria level, and assessment of disease severity of nephrotic syndrome (NS) remained to be investigated. This study aimed to analyzed the correlation between the levels of ANGPTL3 in serum and urine of patients with nephrotic syndrome and proteinuria, and assessed the severity of the patients' disease. In future clinical translation, the level of ANGPTL3 in serum, urine will be used as a biomarker to better predict the development of nephrotic syndrome.

Methods

A total of 200 NS patients and 80 healthy controls (age, 1-18 years) were admitted to our institution between 2021 and 2022. The etiology of NS included primary nephrotic syndrome (PNS, n = 144) and NS with other causes (n = 56). A total of 280 serum samples and 244 urinary samples were collected to determine ANGPTL3 level using enzyme-linked immunosorbent assay (ELISA).

Results

Serum ANGPTL3 and urinary ANGPTL3/Cre were remarkably elevated in NS patients compared with those in healthy controls. Furthermore, serum ANGPTL3 and urinary ANGPTL3/Cre were significantly correlated with proteinuria level. Additionally, multivariate linear regression analysis demonstrated that serum ALB was independently correlated with serum ANGPTL3 and PRO/CR was independently correlated with urinary ANGPTL3/Cre in NS patients.

Conclusion

Serum ANGPTL3 and urinary ANGPTL3/Cre showed a promising performance in the diagnosis of NS, and served as novel potential noninvasive biomarkers to assess disease severity of NS. Further exploration of the role of ANGPTL3 level may shed a new light on the treatment of NS.

Minnelide combined with Angptl3 knockout completely protects mice with adriamycin nephropathy via suppression of TGF-β1-Smad2 and p53 pathways

Minimal change disease (MCD) is the common type of nephrotic syndrome in children. There is an urgent need to explore new treatment methods as current treatments have many drawbacks and cause significant side effects. Our group found that Angiopoietin-like protein 3 (Angptl3) is closely related to renal disease and Angptl3 knockout significantly alleviated proteinuria in mice with adriamycin nephropathy (AN), however, some proteinuria was still present. Minnelide is a water-soluble prodrug of triptolide which has been used for the treatment of glomerular diseases. Therefore, this study aimed to investigate whether minnelide, combined with Angptl3 knockout, could completely protect mice with AN and its mechanism. AN was induced in B6;129S5 female mice by tail vein injection of 25 mg/kg of Adriamycin (ADR), and treatment with 200 ug/kg/d of minnelide. The results showed that minnelide combined with Angptl3 knockout completely reduced proteinuria and restored the foot processes in mice with AN. Moreover, in Angptl3 knockout mice with AN, minnelide restored the distribution of nephrin, podocin and cd2ap and reduced inflammatory factors (Tumor necrosis factor alpha (TNF-α), Interleukin-6 (IL-6) and Interleukin-1β (IL-1β)). Through RNA sequencing and related experiments, we found minnelide could ameliorate fibrosis and apoptosis by inhibiting TGF-β1-Smad2 and p53 pathways in Angptl3 knockout mice with AN, respectively. In Angptl3 knockout primary podocytes, triptolide alleviates ADR-induced decreases in nephrin, podocin and cd2ap, upregulation of Bax and downregulation of Bcl-2. Overall, our study shows that minnelide combined with Angptl3 knockout completely protects mice with AN by inhibiting the TGF-β1-smad2 and p53 pathways.

Selected Soybean Varieties Regulate Hepatic LDL-Cholesterol Homeostasis Depending on Their Glycinin:β-Conglycinin Ratio

Clinical studies indicate that the consumption of soybean protein might reduce cholesterol and LDL levels preventing the development of atherosclerotic cardiovascular diseases. However, soybean variety can influence soybean protein profile and therefore affect soybean protein health-promoting properties. This study investigated the composition and effects of nineteen soybean varieties digested under simulated gastrointestinal conditions on hepatic cholesterol metabolism and LDL oxidation in vitro. Soybean varieties exhibited a differential protein hydrolysis during gastrointestinal digestion. Soybean varieties could be classified according to their composition (high/low glycinin:β-conglycinin ratio) and capacity to inhibit HMGCR (IC50 from 59 to 229 µg protein mL−1). According to multivariate analyses, five soybean varieties were selected. These soybean varieties produced different peptide profiles and differently reduced cholesterol concentration (43−55%) by inhibiting HMGCR in fatty-acid-stimulated HepG2 hepatocytes. Selected digested soybean varieties inhibited cholesterol esterification, triglyceride production, VLDL secretion, and LDL recycling by reducing ANGPTL3 and PCSK9 and synchronously increasing LDLR expression. In addition, selected soybean varieties hindered LDL oxidation, reducing the formation of lipid peroxidation early (conjugated dienes) and end products (malondialdehyde and 4-hydroxynonenal). The changes in HMGCR expression, cholesterol esterification, triglyceride accumulation, ANGPTL3 release, and malondialdehyde formation during LDL oxidation were significantly (p < 0.05) correlated with the glycinin:β-conglycinin ratio. Soybean varieties with lower glycinin:β-conglycinin exhibited a better potential in regulating cholesterol and LDL homeostasis in vitro. Consumption of soybean flour with a greater proportion of β-conglycinin may, consequently, improve the potential of the food ingredient to maintain healthy liver cholesterol homeostasis and cardiovascular function.

Management of Familial Hypercholesterolemia with Special Emphasis on Evinacumab

Familial hypercholesterolemia (FH) is an underdiagnosed disease that contributes to a significant number of cardiovascular incidents through high serum Low-Density Lipoprotein Cholesterol (LDL-C) values. Its treatment primarily requires healthy lifestyle and therapy based on statins, ezetimibe and Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9); however, there are also new treatment options that can be used in patients who do not respond to therapy, among which we highlight evinacumab. Elevated LDL-C values, together with clinical manifestations associated with cholesterol deposition (e.g., tendon xanthomas, xanthelasma and arcus cornealis) and family history are the main elements in the diagnosis of FH. Pathognomonic signs of FH include extensor tendon xanthomas; however, their absence does not exclude the diagnosis. Elevated LDL-C levels lead to premature Atherosclerotic Cardiovascular Disease (ASCVD), which is why early diagnosis and treatment of FH is essential. Evinacumab, a novelty in pharmacological practice, having a complex mechanism of action, causes desirable changes in lipid parameters in patients with homozygous form of familial hypercholesterolemia (HoFH). This review collects and summarizes the most important aspects of the new drug, especially being a discovery in the treatment of HoFH, giving these patients hope for a longer and more comfortable life.

The Egyptian Association of Vascular Biology and Atherosclerosis (EAVA) Perspectives on the Usage of Inclisiran

BACKGROUND

Elevation of low-density lipoprotein cholesterol (LDL-c) is still a hugely unmet need in the reduction of atherosclerotic cardiovascular disease. In the published CardioRisk project in Egypt, up to 71% of female participants had dyslipidemia. Control of LDL-c levels and thus improvement of hyperlipidemia is quite often very difficult. With the introduction of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, the decrease of significant cardiac adverse events, the patient control rate, and the death rate have all been improved. Inhibition of the formation of PCSK9 through inclisiran, which is a novel method of reducing LDL-c and is only given twice per year, seems alluring. After revision of published data, we analyzed the potential advantages of the use of inclisiran.

CONCLUSION

The Egyptian Association for Vascular Biology and Atherosclerosis (EAVA) analyzed the data necessary for obtaining clear indications for the usage of inclisiran. We propose the addition of inclisiran to statins with or without ezetimibe for patients with documented atherosclerotic cardiovascular disease (ASCVD) or similar risk, familial hypercholesterolemia (FH) with another major risk factor, and very high and high risk diabetes mellitus, who did not reach LDL-c goals and/or with true statin intolerance. Inclisiran is also recommended as upfront therapy, with triple combination, in extreme risk subjects such as those with post acute coronary syndromes (ACS).

The Citrus Flavonoid Nobiletin Downregulates Angiopoietin-like Protein 3 (ANGPTL3) Expression and Exhibits Lipid-Modulating Effects in Hepatic Cells and Adult Zebrafish Models

Nobiletin, a dietary citrus flavonoid, exerts biological activities against hyperlipidemia, obesity, and atherosclerotic cardiovascular diseases (ASCVDs). The aim of this study was to explore the lipid-lowering effects of nobiletin and the underlying molecular mechanisms in vitro in hepatic cells and in vivo in zebrafish models. Transcriptome and gene ontology (GO) analyses of differentially expressed genes (DEGs) by gene set enrichment analysis (GSEA) showed that a set of twenty-eight core enrichment DEGs associated with “GO BP regulation of lipid metabolic process” (GO: 0019216) were significantly downregulated in nobiletin-treated cells. Among these genes, angiopoietin-like 3 (ANGPTL3), an inhibitor of lipoprotein lipase (LPL) activity that regulates TG-rich lipoprotein (TGRL) metabolism in circulation, was the protein most markedly downregulated by nobiletin. Nobiletin (20 and 40 μM) significantly reduced the levels of ANGPTL3 mRNA and intracellular and secreted ANGPTL3 proteins in hepatic cell lines. Furthermore, alleviation of secreted ANGPTL3 production by nobiletin was found to reinstate LPL catalytic activity. Nobiletin significantly inhibited ANGPTL3 promoter activity and attenuated the transcription factor liver X receptor-α (LXRα)-mediated ANGPTL3 transcription. Molecular docking analysis predicted that nobiletin could bind to the ligand-binding domain of LXRα, thereby counteracting LXRα activation. In animal studies, orally administered nobiletin significantly alleviated the levels of plasma triglycerides (TGs) and cholesterol in zebrafish fed a high-fat diet. Moreover, nobiletin significantly reduced the amounts of hepatic ANGPTL3 protein in zebrafish. Our findings suggest that nobiletin may regulate the LXRα-ANGPTL3-LPL axis and exhibit lipid-modulating effects in vitro and in vivo. Thus, nobiletin is a potential ANGPTL3 inhibitor for the regulation of lipid metabolism to ameliorate dyslipidemia and ASCVDs.

Critical Overview of Hepatic Factors That Link Non-Alcoholic Fatty Liver Disease and Acute Kidney Injury: Physiology and Therapeutic Implications

Non-alcoholic fatty liver disease (NAFLD) is defined as a combination of a group of progressive diseases, presenting different structural features of the liver at different stages of the disease. According to epidemiological surveys, as living standards improve, the global prevalence of NAFLD increases. Acute kidney injury (AKI) is a class of clinical conditions characterized by a rapid decline in kidney function. NAFLD and AKI, as major public health diseases with high prevalence and mortality, respectively, worldwide, place a heavy burden on societal healthcare systems. Clinical observations of patients with NAFLD with AKI suggest a possible association between the two diseases. However, little is known about the pathogenic mechanisms linking NAFLD and AKI, and the combination of the diseases is poorly treated. Previous studies have revealed that liver-derived factors are transported to distal organs via circulation, such as the kidney, where they elicit specific effects. Of note, while NAFLD affects the expression of many hepatic factors, studies on the mechanisms whereby NAFLD mediates the generation of hepatic factors that lead to AKI are lacking. Considering the unique positioning of hepatic factors in coordinating systemic energy metabolism and maintaining energy homeostasis, we hypothesize that the effects of NAFLD are not only limited to the structural and functional changes in the liver but may also involve the entire body via the hepatic factors, e.g., playing an important role in the development of AKI. This raises the question of whether analogs of beneficial hepatic factors or inhibitors of detrimental hepatic factors could be used as a treatment for NAFLD-mediated and hepatic factor-driven AKI or other metabolic disorders. Accordingly, in this review, we describe the systemic effects of several types of hepatic factors, with a particular focus on the possible link between hepatic factors whose expression is altered under NAFLD and AKI. We also summarize the role of some key hepatic factors in metabolic control mechanisms and discuss their possible use as a preventive treatment for the progression of metabolic diseases.

Circulating levels of PCSK9, ANGPTL3 and Lp(a) in stage III breast cancers

BACKGROUND / SYNOPSIS

Cholesterol and lipids play an important role in sustaining tumor growth and metastasis in a large variety of cancers. ANGPTL3 and PCSK9 modify circulating cholesterol levels, thus availability of lipids to peripheral cells. Little is known on the role, if any, of circulating lipid-related factors such as PCSK9, ANGPTL3 and lipoprotein (a) in cancers.

OBJECTIVE/PURPOSE

To compare circulating levels of PCSK9, ANGPTL3, and Lp(a) in women with stage III breast cancer versus women with premalignant or benign breast lesions.

METHODS

Twenty-three plasma samples from women diagnosed with a stage III breast cancer (ductal, lobular or mixed) were matched for age with twenty-three plasma samples from women bearing premalignant (stage 0, n = 9) or benign (n = 14) breast lesions. The lipid profile (Apo B, total cholesterol, HDL cholesterol and triglycerides levels) and Lp(a) were measured on a Roche Modular analytical platform, whereas LDL levels were calculated with the Friedewald formula. ANGPTL3 and PCSK9 plasma levels were quantitated by ELISA. All statistical analyses were performed using SAS software version 9.4.

RESULTS

PCSK9 levels were significantly higher in women with stage III breast cancer compared to age-matched counterparts presenting a benign lesion (95.9 ± 27.1 ng/mL vs. 78.5 ± 19.3 ng/mL, p < 0.05, n = 14). Moreover, PCSK9 levels positively correlated with breast disease severity (benign, stage 0, stage III) (Rho = 0.34, p < 0.05, n = 46). In contrast, ANGPTL3 and Lp(a) plasma levels did not display any association with breast disease status and lipids did not correlate with disease severity.

CONCLUSION

In this small cohort of 46 women, PCSK9 levels tended to increase with the severity of the breast disease. Given that PCSK9 plays an important role in maintaining cholesterolemia, and a potential role in tumor evasion, present results warrant further investigation into a possible association between PCSK9 levels and breast cancer severity in larger cohorts of women.

Angiopoietin-Like Protein 3 (ANGPTL3) Inhibitors in the Management of Refractory Hypercholesterolemia

Cardiovascular disease (CVD) is the most common cause of death in a global scale and significantly depends on the elevated plasma levels of low-density lipoprotein cholesterol (LDL-C) and the subsequent formation of atherosclerotic plaques. While physicians have several LDL-C-lowering agents with diverse mechanisms of action, including statins, ezetimibe, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors and inclisiran, angiopoietin-like protein 3 (ANGPTL3) inhibitors have recently emerged as a powerful addition in the armamentarium of lipid-lowering strategies, especially for patients with refractory hypercholesterolemia, as in the case of patients with homozygous familial hypercholesterolemia (HoFH). ANGPTL3 protein is a glycoprotein secreted by liver cells that is implicated in the metabolism of lipids along with other ANGPTL proteins. These proteins inhibit lipoprotein lipase (LPL) and endothelial lipase (EL) in tissues. Loss-of-function mutations affecting the gene encoding ANGPTL3 are linked with lower total cholesterol, LDL-C, and triglyceride (TG) levels. Evinacumab is a monoclonal antibody that targets, binds to, and pharmacologically inhibits ANGPTL3, which was recently approved by the United States Food and Drug Administration (FDA) as a complementary agent to other LDL-C lowering regimens for patients aged 12 or older with HoFH, based on clinical trial evidence that confirmed its safety and efficacy in those patients. Antisense oligonucleotides (ASOs) also represent an interesting class of agents that target and inhibit the mRNA derived from the transcription of ANGPTL3 gene. This review aims to present and discuss the current clinical and scientific data pertaining to the role of ANGPTL3 inhibitors, a novel lipid-modifying class of agents capable of reducing LDL-C levels via a mechanism independent of LDL receptors.

Eruptive xanthomas as a marker for metabolic disorders: A specific form of xanthoma that reflects hypertriglyceridemia

Eruptive xanthomas are skin manifestations associated with hypertriglyceridemia. Accordingly, the improvement of hypertriglyceridemia can ameliorate this condition. We report a case of a patient with type 2 diabetes mellitus who was diagnosed with this skin lesion. Clinicians should be aware that eruptive xanthomas could indicate metabolic disorders associated with atherosclerosis.

Treating Cardiovascular Disease with Liver Genome Engineering

Purpose of Review

This review examines recent progress in somatic genome editing for cardiovascular disease. We briefly highlight new gene editing approaches, delivery systems, and potential targets in the liver.

Recent Findings

In recent years, new editing and delivery systems have been applied successfully in model organisms to modify genes within hepatocytes. Disruption of several genes has been shown to dramatically lower plasma cholesterol and triglyceride levels in mice as well as non-human primates. More precise modification of cardiovascular targets has also been achieved through homology-directed repair or base editing. Improved viral vectors and nanoparticle delivery systems are addressing important delivery challenges and helping to mitigate safety concerns.

Summary

Liver-directed genome editing has the potential to cure both rare and common forms of cardiovascular disease. Exciting progress is already being made, including promising results from preclinical studies and the initiation of human gene therapy trials.

ANGPTL3 as a Drug Target in Hyperlipidemia and Atherosclerosis

PURPOSE OF REVIEW

Elevated low-density lipoprotein cholesterol (LDL-C) and triglyceride-rich lipoproteins (TRLs) or remnants are important risk factors for the development of atherosclerotic cardiovascular disease (ASCVD). The ongoing challenge of not being able to achieve recommended LDL-C targets despite maximally tolerated lipid-lowering therapy (LLT) has led to the development of novel therapeutic agents including angiopoietin-like 3 (ANGPTL3) inhibitors.

RECENT FINDINGS

ANGPTL3 is a glycoprotein produced by the liver that inhibits lipoprotein lipase and endothelial lipase. Data from genetic and clinical studies have shown that a lower ANGPTL3 level is associated with lower plasma LDL-C, triglyceride (TG), and other lipoproteins. Pharmacological inactivation of ANGPTL3 with the monoclonal antibody, evinacumab, results in a 50% reduction in LDL-C, even in patients with homozygous familial hypercholesterolemia (HoFH). The safe and effective targeted delivery of nucleic acid-based therapies will shape the future of the lipid arena. ANGPTL3 is a novel target in lipoprotein metabolism, targeting not only LDL-C via an LDL-receptor (LDLR) independent mechanism but also TRLs and carries a significant promise for further ASCVD risk reduction.

The Lipid-Modulating Effect of Tangeretin on the Inhibition of Angiopoietin-like 3 (ANGPTL3) Gene Expression through Regulation of LXRα Activation in Hepatic Cells

The excessive accumulation of TG-rich lipoproteins (TGRLs) in plasma is associated with dyslipidemia and atherosclerotic cardiovascular diseases (ASCVDs). Tangeretin is a bioactive pentamethoxyflavone mainly found in citrus peels, and it has been reported to protect against hyperlipidemia, diabetes, and obesity. The aim of this study was to investigate the lipid-modulating effects and the underlying mechanisms of tangeretin action in hepatic cells. Transcriptome and bioinformatics analyses with the Gene Ontology (GO) database showed that tangeretin significantly regulated a set of 13 differentially expressed genes (DEGs) associated with the regulation of lipoprotein lipase (LPL) activity. Among these DEGs, angiopoietin-like 3 (ANGPTL3), an essential inhibitor of LPL catalytic activity that regulates TGRL metabolism in plasma, was markedly downregulated by tangeretin. We demonstrated that tangeretin significantly inhibited the mRNA expression of ANGPTL3 in HepG2 and Huh-7 cells. Tangeretin treatment of hepatic cells also reduced the levels of both intracellular and secreted ANGPTL3 proteins. Moreover, we found that inhibition of ANGPTL3 production by tangeretin augmented LPL activity. We further demonstrated that the transcriptional activity of the ANGPTL3 promoter was significantly attenuated by tangeretin, and we identified a DNA element located between the −250 and −121 positions that responded to tangeretin. Furthermore, we found that tangeretin did not alter the levels of the nuclear liver X receptor α (LXRα) protein, an essential transcription factor that binds to the tangeretin-responsive element, but it can counteract LXRα-mediated ANGPTL3 transcription. On the basis of molecular docking analysis, tangeretin was predicted to bind to the ligand-binding domain of LXRα, which would result in suppression of LXRα activation. Our findings support the hypothesis that tangeretin exerts a lipid-lowering effect by modulating the LXRα-ANGPTL3-LPL pathway, and thus, it can be used as a potential phytochemical for the prevention or treatment of dyslipidemia.