Pharmacological aspects of ANGPTL3 and ANGPTL4 inhibitors: New therapeutic approaches for the treatment of atherogenic dyslipidemia

Genetic Association of Lipids and Lipid-Lowering Drug Target Genes With Attention Deficit Hyperactivity Disorder

BACKGROUND

Lipid metabolism plays an essential role in nervous system development. Cholesterol deficiency leads to a variety of neurodevelopmental disorders, such as autism spectrum disorder and fragile X syndrome. There have been a lot of efforts to search for biological markers associated with and causal to ADHD, among which lipid is one possible etiological factor that is quite widely studied. We aimed to evaluate the causal relationship between lipids traits, lipid-lowering drugs, and attention deficit hyperactivity disorder (ADHD) outcomes using Mendelian randomization (MR) studies.

METHODS

We used summary data from genome-wide association studies to explore the causal relationships between circulating lipid-related traits and ADHD. Then, quantitative trait loci for the expression of lipid-lowering drug target genes and genetic variants associated with lipid traits were extracted. Summary-data-based MR and inverse-variance-weighted MR (IVW-MR) were used to investigate the correlation between the expression of these drug-target genes and ADHD.

RESULTS

After rigorous screening, 939 instrumental variables were finally included for univariable mendelian randomization analysis. However, there is no correlation between lipid profile and ADHD risk. Drug target analysis by IVW-MR method observed that APOB-mediated low-density lipoprotein cholesterol was associated with lower ADHD risk (odds ratio [OR] = 0.90, 95% confidence interval [CI] [0.84, 0.97]; p = .007), whereas LPL-mediated triglycerides levels were associated with a higher risk of ADHD (OR = 1.13, 95% CI [1.06, 1.21]; p < .001).

CONCLUSION

Our results suggest that APOB gene and LPL gene may be candidate drug target genes for the treatment of ADHD.

Lipid nanoparticle (LNP) mediated mRNA delivery in cardiovascular diseases: Advances in genome editing and CAR T cell therapy

Cardiovascular diseases (CVDs) are the leading cause of global mortality among non-communicable diseases. Current cardiac regeneration treatments have limitations and may lead to adverse reactions. Hence, innovative technologies are needed to address these shortcomings. Messenger RNA (mRNA) emerges as a promising therapeutic agent due to its versatility in encoding therapeutic proteins and targeting "undruggable" conditions. It offers low toxicity, high transfection efficiency, and controlled protein production without genome insertion or mutagenesis risk. However, mRNA faces challenges such as immunogenicity, instability, and difficulty in cellular entry and endosomal escape, hindering its clinical application. To overcome these hurdles, lipid nanoparticles (LNPs), notably used in COVID-19 vaccines, have a great potential to deliver mRNA therapeutics for CVDs. This review highlights recent progress in mRNA-LNP therapies for CVDs, including Myocardial Infarction (MI), Heart Failure (HF), and hypercholesterolemia. In addition, LNP-mediated mRNA delivery for CAR T-cell therapy and CRISPR/Cas genome editing in CVDs and the related clinical trials are explored. To enhance the efficiency, safety, and clinical translation of mRNA-LNPs, advanced technologies like artificial intelligence (AGILE platform) in RNA structure design, and optimization of LNP formulation could be integrated. We conclude that the strategies to facilitate the extra-hepatic delivery and targeted organ tropism of mRNA-LNPs (SORT, ASSET, SMRT, and barcoded LNPs) hold great prospects to accelerate the development and translation of mRNA-LNPs in CVD treatment.

Association of Genotypes of ANGPTL3 with Vitamin D and Calcium Concentration in Cardiovascular Disease

One of the leading causes of mortality worldwide is cardiovascular disease, which is influenced by some variables, including calcium and vitamin D. This study aimed to assess the relationship between Angiopoietin-Like 3 (ANGPTL3) gene polymorphisms with vitamin D and calcium levels in cardiovascular disease (CVD) patients. In this research, 1002 people participated. Participants' anthropometric parameters, and FBG, calcium, and vitamin D were assessed. Blood samples were used to extract DNA. Taqman®-based polymerase chain reaction (PCR) was used to conduct genetic analysis for the rs10789117 and rs17458195. Statistical analysis was applied to determine differences across subgroups and the relationship between polymorphisms and disease. Age, body mass index (BMI), fasting Blood Sugar (FBG), phenylalanine ammonia-lyase (PAL), and smoking history were significantly correlated with CVD. Vitamin D was statistically associated with rs10789117 and rs17458195 in non-CVD individuals. In the moderate group, individuals with the C allele in rs10789117 showed a tenfold increase in vitamin D deficiency compared to those with the A allele. However, in rs11207997, individuals with the T allele had 5 to 6 times higher vitamin D deficiency than those with the C allele in all groups. This research demonstrates the relationship between some ANGPTL3 gene polymorphisms and complement levels in CVD patients. It may be concluded that individuals carrying these variants would likely benefit from using vitamin D and calcium supplements to avoid CVD.

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.

Gene Silencing of Angiopoietin-like 3 (ANGPTL3) Induced De Novo Lipogenesis and Lipid Accumulation in Huh7 Cell Line

Angiopoietin-like 3 (ANGPTL3) is a hepatokine acting as a negative regulator of lipoprotein lipase (LPL). Vupanorsen, an ANGPTL3 directed antisense oligonucleotide, showed an unexpected increase in liver fat content in humans. Here, we investigated the molecular mechanism linking ANGPTL3 silencing to hepatocyte fat accumulation. Human hepatocarcinoma Huh7 cells were treated with small interfering RNA (siRNA) directed to ANGPTL3, human recombinant ANGPTL3 (recANGPTL3), or their combination. Using Western blot, Oil Red-O, biochemical assays, and ELISA, we analyzed the expression of genes and proteins involved in lipid metabolism. Oil Red-O staining demonstrated that lipid content increased after 48 h of ANGPTL3 silencing (5.89 ± 0.33 fold), incubation with recANGPTL3 (4.08 ± 0.35 fold), or their combination (8.56 ± 0.18 fold), compared to untreated cells. This effect was also confirmed in Huh7-LX2 spheroids. A total of 48 h of ANGPTL3 silencing induced the expression of genes involved in the de novo lipogenesis, such as fatty acid synthase, stearoyl-CoA desaturase, ATP citrate lyase, and Acetyl-Coenzyme A Carboxylase 1 together with the proprotein convertase subtilisin/kexin 9 (PCSK9). Time-course experiments revealed that 6 h post transfection with ANGPTL3-siRNA, the cholesterol esterification by Acyl-coenzyme A cholesterol acyltransferase (ACAT) was reduced, as well as total cholesterol content, while an opposite effect was observed at 48 h. Under the same experimental conditions, no differences in secreted apoB and PCSK9 were observed. Since PCSK9 was altered by the treatment, we tested a possible co-regulation between the two genes. The effect of ANGPTL3-siRNA on the expression of genes involved in the de novo lipogenesis was not counteracted by gene silencing of PCSK9. In conclusion, our in vitro study suggests that ANGPTL3 silencing determines lipid accumulation in Huh7 cells by inducing the de novo lipogenesis independently from PCSK9.

Single-cell transcriptomic profiling of heart reveals ANGPTL4 linking fibroblasts and angiogenesis in heart failure with preserved ejection fraction

INTRODUCTION

Despite the high morbidity and mortality, the effective therapies for heart failure with preserved fraction (HFpEF) are limited as the poor understand of its pathophysiological basis.

OBJECTIVE

This study was aimed to characterize the cellular heterogeneity and potential mechanisms of HFpEF at single-cell resolution.

METHODS

An HFpEF mouse model was induced by a high-fat diet with N-nitro-L-arginine methyl ester. Cells from the hearts were subjected to single-cell sequencing. The key protein expression was measured with Immunohistochemistry and immunofluorescence staining.

RESULTS

In HFpEF hearts, myocardial fibroblasts exhibited higher levels of fibrosis. Furthermore, an increased number of fibroblasts differentiated into high-metabolism and high-fibrosis phenotypes. The expression levels of genes encoding certain pro-angiogenic secreted proteins were decreased in the HFpEF group, as confirmed by bulk RNA sequencing. Additionally, the proportion of the endothelial cell (EC) lineages in the HFpEF group was significantly downregulated, with low angiogenesis and high apoptosis phenotypes observed in these EC lineages. Interestingly, the fibroblasts in the HFpEF heart might cross-link with the EC lineages via over-secretion of ANGPTL4, thus displaying an anti-angiogenic function. Immunohistochemistry and immunofluorescence staining then revealed the downregulation of vascular density and upregulation of ANGPTL4 expression in HFpEF hearts. Finally, we predicted ANGPTL4as a potential druggable target using DrugnomeAI.

CONCLUSION

In conclusion, this study comprehensively characterized the angiogenesis impairment in HFpEF hearts at single-cell resolution and proposed that ANGPTL4 secretion by fibroblasts may be a potential mechanism underlying this angiogenic abnormality.

Effects of exercise training on ANGPTL3/8 and ANGPTL4/8 and their associations with cardiometabolic traits

Angiopoietin-like protein (ANGPTL) complexes 3/8 and 4/8 are established inhibitors of LPL and novel therapeutic targets for dyslipidemia. However, the effects of regular exercise on ANGPTL3/8 and ANGPTL4/8 are unknown. We characterized ANGPTL3/8 and ANGPTL4/8 and their relationship with in vivo measurements of lipase activities and cardiometabolic traits before and after a 5-month endurance exercise training intervention in 642 adults from the HERITAGE (HEalth, RIsk factors, exercise Training And GEnetics) Family Study. At baseline, higher levels of both ANGPTL3/8 and ANGPTL4/8 were associated with a worse lipid, lipoprotein, and cardiometabolic profile, with only ANGPTL3/8 associated with postheparin LPL and HL activities. ANGPTL3/8 significantly decreased with exercise training, which corresponded with increases in LPL activity and decreases in HL activity, plasma triglycerides, apoB, visceral fat, and fasting insulin (all P < 5.1 × 10-4). Exercise-induced changes in ANGPTL4/8 were directly correlated to concomitant changes in total cholesterol, LDL-C, apoB, and HDL-triglycerides and inversely related to change in insulin sensitivity index (all P < 7.0 × 10-4). In conclusion, exercise-induced decreases in ANGPTL3/8 and ANGPTL4/8 were related to concomitant improvements in lipase activity, lipid profile, and cardiometabolic risk factors. These findings reveal the ANGPTL3-4-8 model as a potential molecular mechanism contributing to adaptations in lipid metabolism in response to exercise training.

Correlation between the serum FABP4, ANGPTL3, and ANGPTL4 levels and coronary artery disease

BACKGROUND

Lipid metabolism related factors, such as angiopoietin-like protein 3 (ANGPTL3), angiopoietin-like 4 (ANGPTL4), fatty acid-binding protein 4 (FABP4) are newly discovered factors that can affect coronary artery disease (CAD). In this study, we aimed to investigate the relationship between CAD and these lipid metabolism factors.

HYPOTHESIS

ANGPTL3, ANGPTL4, and FABP4 may provide a new method for the control of CAD risk factors and the prevention and treatment of CAD.

METHODS

We enrolled 284 consecutive inpatients with suspected CAD and divided them into CAD and non-CAD groups based on the coronary angiography results. Serum ANGPTL3, ANGPTL4, FABP4, and tumor necrosis factor-α (TNF-α) levels were estimated using the enzyme-linked immunosorbent assay. Multivariate logistic regression was used to assess the risk factors for CAD. The receiver operating characteristic curve was used to determine the cutoff and diagnostic values.

RESULTS

The serum TNF-α, FABP4, ANGPTL3, and ANGPTL4 values showed a significant difference between the CAD and non-CAD groups (p < .05). After adjusting for confounding factors, the FABP4, ANGPTL3, and ANGPTL4 levels were independently associated with CAD (p < .05). The ANGPTL3 expression level was an independent risk factor for CAD in patients with hypertension, but not in those without hypertension. The ANGPTL3 > 67.53 ng/mL, ANGPTL4 > 29.95 ng/mL, and FABP4 > 1421.25 ng/L combination had the highest diagnostic value for CAD.

CONCLUSION

ANGPTL3, ANGPTL4, and FABP4 were identified as independent risk factors for CAD and have valuable clinical implications for the diagnosis and treatment of CAD.

ANGPTL3 negatively regulates IL-1β-induced NF-κB activation by inhibiting the IL1R1-associated signaling complex assembly

Interleukin-1β (IL-1β)-induced signaling is one of the most important pathways in regulating inflammation and immunity. The assembly of the receptor complex, consisting of the ligand IL-1β, the IL-1 receptor (IL-1R) type 1 (IL1R1), and the IL-1R accessory protein (IL1RAP), initiates this signaling. However, how the IL1R1-associated complex is regulated remains elusive. Angiopoietin like 3 (ANGPTL3), a key inhibitor of plasma triglyceride clearance, is mainly expressed in the liver and exists in both intracellular and extracellular secreted forms. Currently, ANGPTL3 has emerged as a highly promising drug target for hypertriglyceridemia and associated cardiovascular diseases. However, most studies have focused on the secreted form of ANGPTL3, while its intracellular role is still largely unknown. Here, we report that intracellular ANGPTL3 acts as a negative regulator of IL-1β-triggered signaling. Overexpression of ANGPTL3 inhibited IL-1β-induced NF-κB activation and the transcription of inflammatory genes in HepG2, THP1, and HEK293T cells, while knockdown or knockout of ANGPTL3 resulted in opposite effects. Mechanistically, ANGPTL3 interacted with IL1R1 and IL1RAP through its intracellular C-terminal fibrinogen-like domain and disrupted the assembly of the IL1R1-associated complex. Taken together, our study reveals a novel role for ANGPTL3 in inflammation, whereby it inhibits the physiological interaction between IL1R1 and IL1RAP to maintain immune tolerance and homeostasis in the liver.

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.

The GPIHBP1-LPL complex and its role in plasma triglyceride metabolism: Insights into chylomicronemia

GPIHBP1 is a protein found in the endothelial cells of capillaries that is anchored by glycosylphosphatidylinositol and binds to high-density lipoproteins. GPIHBP1 attaches to lipoprotein lipase (LPL), subsequently carrying the enzyme and anchoring it to the capillary lumen. Enabling lipid metabolism is essential for the marginalization of lipoproteins alongside capillaries. Studies underscore the significance of GPIHBP1 in transporting, stabilizing, and aiding in the marginalization of LPL. The intricate interplay between GPIHBP1 and LPL has provided novel insights into chylomicronemia in recent years. Mutations hindering the formation or reducing the efficiency of the GPIHBP1-LPL complex are central to the onset of chylomicronemia. This review delves into the structural nuances of the GPIHBP1-LPL interaction, the consequences of mutations in the complex leading to chylomicronemia, and cutting-edge advancements in chylomicronemia treatment.

Updates in Small Interfering RNA for the Treatment of Dyslipidemias

PURPOSE OF REVIEW

Atherosclerotic cardiovascular disease (ASCVD) is still the leading cause of death worldwide. Despite excellent pharmacological approaches, clinical registries consistently show that many people with dyslipidemia do not achieve optimal management, and many of them are treated with low-intensity lipid-lowering therapies. Beyond the well-known association between low-density lipoprotein cholesterol (LDL-C) and cardiovascular prevention, the atherogenicity of lipoprotein(a) and the impact of triglyceride (TG)-rich lipoproteins cannot be overlooked. Within this landscape, the use of RNA-based therapies can help the treatment of difficult to target lipid disorders.

RECENT FINDINGS

The safety and efficacy of LDL-C lowering with the siRNA inclisiran has been documented in the open-label ORION-3 trial, with a follow-up of 4 years. While the outcome trial is pending, a pooled analysis of ORION-9, ORION-10, and ORION-11 has shown the potential of inclisiran to reduce composite major adverse cardiovascular events. Concerning lipoprotein(a), data of OCEAN(a)-DOSE trial with olpasiran show a dose-dependent drop in lipoprotein(a) levels with an optimal pharmacodynamic profile when administered every 12 weeks. Concerning TG lowering, although ARO-APOC3 and ARO-ANG3 are effective to lower apolipoprotein(apo)C-III and angiopoietin-like 3 (ANGPTL3) levels, these drugs are still in their infancy. In the era moving toward a personalized risk management, the use of siRNA represents a blossoming armamentarium to tackle dyslipidaemias for ASCVD risk reduction.

Phylogenetic and expression analysis of the angiopoietin-like gene family and their role in lipid metabolism in pigs

OBJECTIVE

The objective of this study was to investigate the phylogenetic and expression analysis of the angiopoietin-like (ANGPTL) gene family and their role in lipid metabolism in pigs.

METHODS

In this study, the amino acid sequence analysis, phylogenetic analysis, and chromosome adjacent gene analysis were performed to identify the ANGPTL gene family in pigs. According to the body weight data from 60 Jinhua pigs, different tissues of 6 pigs with average body weight were used to determine the expression profile of ANGPTL1-8. The ileum, subcutaneous fat, and liver of 8 pigs with distinct fatness were selected to analyze the gene expression of ANGPTL3, ANGPTL4, and ANGPTL8.

RESULTS

The sequence length of ANGPTLs in pigs was between 1,186 and 1,991 bp, and the pig ANGPTL family members shared common features with human homologous genes, including the high similarity of the amino acid sequence and chromosome flanking genes. Amino acid sequence analysis showed that ANGPTL1-7 had a highly conserved domain except for ANGPTL8. Phylogenetic analysis showed that each ANGPTL homologous gene shared a common origin. Quantitative reverse-transcription polymerase chain reaction analysis showed that ANGPTL family members had different expression patterns in different tissues. ANGPTL3 and ANGPTL8 were mainly expressed in the liver, while ANGPTL4 was expressed in many other tissues, such as the intestine and subcutaneous fat. The expression levels of ANGPTL3 in the liver and ANGPTL4 in the liver, intestine and subcutaneous fat of Jinhua pigs with low propensity for adipogenesis were significantly higher than those of high propensity for adipogenesis.

CONCLUSION

These results increase our knowledge about the biological role of the ANGPTL family in this important economic species, it will also help to better understand the role of ANGPTL3, ANGPTL4, and ANGPTL8 in lipid metabolism of pigs, and provide innovative ideas for developing strategies to improve meat quality of pigs.

Angiopoietin-like 4 induces head and neck squamous cell carcinoma cell migration through the NRP1/ABL1/PXN pathway

OBJECTIVES

The molecular mechanisms whereby angiopoietin-like 4 (ANGPTL4), a pluripotent protein implicated in cancer development, contributes to head and neck squamous cell carcinoma (HNSCC) growth and dissemination are unclear.

MATERIALS AND METHODS

We investigated ANGPTL4 expression in human normal oral keratinocytes (NOKs), dysplastic oral keratinocytes (DOKs), oral leukoplakia cells (LEUK1), and HNSCC cell lines, as well as in tissue biopsies from patients with oral dysplasia, and primary and metastatic HNSCC. We further examined the contribution of ANGPTL4 cancer progression in an HNSCC orthotopic floor-of mouth tumor model and the signaling pathways linking ANGPTL4 to cancer cell migration.

RESULTS

ANGPTL4 expression was upregulated in premalignant DOKs and HNSCC cell lines compared to NOKs and was increased in tissue biopsies from patients with oral dysplasia, as well as in primary and metastatic HNSCC. We also observed that downregulation of ANGPTL4 expression inhibited primary and metastatic cancer growth in an HNSCC orthotopic tumor model. Interestingly, ANGPTL4 binding to the neuropilin1 (NRP1) receptor led to phosphorylation of the focal adhesion protein, paxillin (PXN), and tumor cell migration; this was dependent on the tyrosine kinase ABL1. Treatment with the ABL1 inhibitor, dasatinib and small interfering RNA silencing of NRP1 or ABL1 expression blocked PXN phosphorylation and tumor cell migration.

CONCLUSION

Our findings suggest an early, sustained, and angiogenesis-independent autocrine role for ANGPTL4 in HNSCC progression and expose ANGPTL4/NRP1/ABL1/PXN as an early molecular marker and vulnerable target for the prevention of HNSCC growth and metastasis.

A novel HIF2A mutation causes dyslipidemia and promotes hepatic lipid accumulation

Hypoxia-inducible factor-2α (HIF-2α) is a transcription factor responsible for regulating genes related to angiogenesis and metabolism. This study aims to explore the effect of a previously unreported mutation c.C2473T (p.R825S) in the C-terminal transactivation domain (CTAD) of HIF-2α that we detected in tissue of patients with liver disease. We sequenced available liver and matched blood samples obtained during partial liver resection or liver transplantation performed for clinical indications including hepatocellular carcinoma and liver failure. In tandem, we constructed cell lines and a transgenic mouse model bearing the corresponding identified mutation in HIF-2α from which we extracted primary hepatocytes. Lipid accumulation was evaluated in these cells and liver tissue from the mouse model using Oil Red O staining and biochemical measurements. We identified a mutation in the CTAD of HIF-2α (c.C2473T; p.R825S) in 5 of 356 liver samples obtained from patients with hepatopathy and dyslipidemia. We found that introduction of this mutation into the mouse model led to an elevated triglyceride level, lipid droplet accumulation in liver of the mutant mice and in their extracted primary hepatocytes, and increased transcription of genes related to hepatic fatty acid transport and synthesis in the mutant compared to the control groups. In mutant mice and cells, the protein levels of nuclear HIF-2α and its target perilipin-2 (PLIN2), a lipid droplet-related gene, were also elevated. Decreased lipophagy was observed in mutant groups. Our study defines a subpopulation of dyslipidemia that is caused by this HIF-2α mutation. This may have implications for personalized treatment.

Application of systemic inflammation indices and lipid metabolism-related factors in coronary artery disease

OBJECTIVE

We aimed to investigate the relationship between coronary artery disease (CAD) and systemic inflammation indices and lipid metabolism-related factors and subsequently, discuss the clinical application of these factors in CAD.

METHODS

We enrolled 284 consecutive inpatients with suspected CAD and divided them into a CAD group and a non-CAD group according to coronary angiography results. Serum levels of angiopoietin-like protein 3 (ANGPTL3), angiopoietin-like protein 4 (ANGPTL4), fatty acid-binding protein 4 (FABP4), and tumor necrosis factor-α (TNF-α) levels were assessed using the ELISA and the systemic inflammation indices were calculated. Multivariate logistic regression was used to assess the risk factors of CAD. The receiver operating characteristic curve was used to determine the cutoff and diagnostic values.

RESULTS

The neutrophil-to-high density lipoprotein cholesterol ratio (5.04 vs. 3.47), neutrophil-to-lymphocyte ratio (3.25 vs. 2.45), monocyte-to-high density lipoprotein cholesterol ratio (MHR) (0.46 vs. 0.36), monocyte-to-lymphocyte ratio (0.31 vs. 0.26), systemic immune-inflammation index (SII) (696.00 vs. 544.82), serum TNF-α (398.15 ng/l vs. 350.65 ng/l), FABP4 (1644.00 ng/l vs. 1553.00 ng/l), ANGPTL3 (57.60 ng/ml vs. 52.85 ng/ml), and ANGPTL4 (37.35 ng/ml vs. 35.20 ng/ml) values showed a significant difference between the CAD and non-CAD groups ( P  < 0.05). After adjusting for confounding factors, the following values were obtained: ANGPTL3 > 67.53 ng/ml [odds ratio (OR) = 8.108, 95% confidence interval (CI) (1.022-65.620)]; ANGPTL4 > 29.95 ng/ml [OR = 5.599, 95% CI (1.809-17.334)]; MHR > 0.47 [OR = 4.872, 95% CI (1.715-13.835)]; SII > 589.12 [OR = 5.131, 95% CI (1.995-13.200)]. These factors were found to be independently associated with CAD ( P  < 0.05). Diabetes combined with MHR > 0.47, SII > 589.12, TNF-α >285.60 ng/l, ANGPTL3 > 67.53 ng/ml, and ANGPTL4 > 29.95 ng/l had the highest diagnostic value for CAD [area under the curve: 0.921, 95% CI, (0.881-0.960), Sensitivity: 88.9%, Specificity: 82.2%, P  < 0.001].

CONCLUSION

MHR > 0.47, SII > 589.12, TNF-α >285.60 ng/l, ANGPTL3 > 67.53 ng/ml, and ANGPTL4 > 29.95 ng/l were identified as independent CAD risk factors and have valuable clinical implications in the diagnosis and treatment of CAD.

Prospects of potential adipokines as therapeutic agents in obesity-linked atherogenic dyslipidemia and insulin resistance

BACKGROUND

In normal circumstances, AT secretes anti-inflammatory adipokines (AAKs) which regulates lipid metabolism, insulin sensitivity, vascular hemostasis, and angiogenesis. However, during obesity AT dysfunction occurs and leads to microvascular imbalance and secretes several pro-inflammatory adipokines (PAKs), thereby favoring atherogenic dyslipidemia and insulin resistance. Literature suggests decreased levels of circulating AAKs and increased levels of PAKs in obesity-linked disorders. Importantly, AAKs have been reported to play a vital role in obesity-linked metabolic disorders mainly insulin resistance, type-2 diabetes mellitus and coronary heart diseases. Interestingly, AAKs counteract the microvascular imbalance in AT and exert cardioprotection via several signaling pathways such as PI3-AKT/PKB pathway. Although literature reviews have presented a number of investigations detailing specific pathways involved in obesity-linked disorders, literature concerning AT dysfunction and AAKs remains sketchy. In view of the above, in the present contribution an effort has been made to provide an insight on the AT dysfunction and role of AAKs in modulating the obesity and obesity-linked atherogenesis and insulin resistance.

MAIN BODY

"Obesity-linked insulin resistance", "obesity-linked cardiometabolic disease", "anti-inflammatory adipokines", "pro-inflammatory adipokines", "adipose tissue dysfunction" and "obesity-linked microvascular dysfunction" are the keywords used for searching article. Google scholar, Google, Pubmed and Scopus were used as search engines for the articles.

CONCLUSIONS

This review offers an overview on the pathophysiology of obesity, management of obesity-linked disorders, and areas in need of attention such as novel therapeutic adipokines and their possible future perspectives as therapeutic agents.

The Impact of the Blood Lipids Levels on Arterial Stiffness

Arterial stiffness is a recognized predictor of cardiovascular morbidity and death. It is an early indicator of arteriosclerosis and is influenced by numerous risk factors and biological processes. The lipid metabolism is crucial and standard blood lipids, non-conventional lipid markers and lipid ratios are associated with arterial stiffness. The objective of this review was to determine which lipid metabolism marker has a greater correlation with vascular aging and arterial stiffness. Triglycerides (TG) are the standard blood lipids that have the strongest associations with arterial stiffness, and are often linked to the early stages of cardiovascular diseases, particularly in patients with low LDL-C levels. Studies often show that lipid ratios perform better overall than any of the individual variables used alone. The relation between arterial stiffness and TG/HDL-C has the strongest evidence. It is the lipid profile of atherogenic dyslipidemia that is found in several chronic cardio-metabolic disorders, and is considered one of the main causes of lipid-dependent residual risk, regardless of LDL-C concentration. Recently, the use of alternative lipid parameters has also been increasing. Both non-HDL and ApoB are very well correlated with arterial stiffness. Remnant cholesterol is also a promising alternative lipid parameter. The findings of this review suggest that the main focus should be on blood lipids and arterial stiffness, especially in individuals with cardio-metabolic disorders and residual cardiovascular risk.

Recent Advances in Gene Therapy for Familial Hypercholesterolemia: An Update Review

(1) Background: Existing lipid-lowering therapies have difficulty in achieving lipid target levels in patients with familial hypercholesterolemia (FH), especially in the treatment of patients with homozygous familial hypercholesterolemia. (2) Method: All of the literature data containing "Familial hypercholesterolemia" and "Gene Therapy" in PubMed and Clinical Trials from 2018 to 2022 were selected. (3) Results: The rapid development of gene therapy technology in recent years is expected to change the treatment status of FH patients. As emerging gene therapy vectors, the optimized adeno-associated viruses, exosomes, and lipid nanoparticles have demonstrated an improved safety and higher transfection efficiency. Various RNA-targeted therapies are in phase 1-3 clinical trials, such as small interfering RNA-based drugs inclisiran, ARO-ANG3, ARO-APOC3, olpasiran, SLN360, and antisense oligonucleotide-based drugs AZD8233, vupanorsen, volanesorsen, IONIS-APO(a)Rx, etc., all of which have demonstrated excellent lipid-lowering effects. With gene editing technologies, such as CRISPR-Cas 9 and meganuclease, completing animal experiments in mice or cynomolgus monkeys and demonstrating lasting lipid-lowering effects, patients with FH are expected to reach a permanent cure in the future. (4) Conclusion: Gene therapy is being widely used for the lipid-lowering treatment of FH patients and has shown excellent therapeutic promise, but the current delivery efficiency, economic burden, immunogenicity and the precision of gene therapy can be further optimized.

Long-Term Efficacy and Safety of Evinacumab in Patients with Homozygous Familial Hypercholesterolemia: Real-World Clinical Experience

Homozygous familial hypercholesterolemia (HoFH) is a rare, genetic condition characterized by markedly elevated plasma low-density lipoprotein cholesterol (LDL-C) concentrations from birth and increased risk of premature atherosclerotic cardiovascular disease. Evinacumab is an inhibitor of angiopoietin-like 3 protein that offers a new approach for correcting high LDL-C in HoFH. Evinacumab was administered intravenously (15 mg/kg Q4W) for 24 months in 7 patients with genetically confirmed HoFH, receiving background lipoprotein apheresis (LA) and/or lipid-lowering treatment (LLT). Assessment of efficacy and safety were carried out before and after 24 months of evinacumab treatment. The LDL-C lowering effect of evinacumab without LA were also investigated in the 7 HoFH patients after a subsequent compassionate extension period. Twenty-four months of treatment with evinacumab against background LA and LLT resulted in a significant reduction in LDL-C (−46.8%; p < 0.001). LDL-C reduction with evinacumab was maintained during the compassionate extensions period in the absence of treatment with LA (−43.4%; mean follow-up of 208 ± 90 days). Evinacumab was well-tolerated, with no major adverse event reported or significant changes in liver and muscle enzyme concentrations. Our findings suggest that evinacumab is a safe and effective treatment for patients with HoFH receiving best standard of care in a routine setting.

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.

Angiopoietin-Like 4 (ANGPTL4) in Patients with Psoriasis, Lichen Planus and Vitiligo-A Pilot Study from the Bialystok+ Polish Longitudinal University Study

Psoriasis, vitiligo and lichen planus (LP) are autoimmune skin diseases associated with metabolic syndrome. Angiopoietin-like 4 (ANGPTL4) is a member of angiopoietin-like proteins, which play an important role in lipid metabolism, and its serum concentration has been proposed as a biomarker of cardiometabolic complications, especially coronary artery disease (CAD). The study involved 56 patients with abovementioned dermatoses and 29 sex- and age-matched volunteers without dermatoses. ANGPTL4 serum concentration was measured by ELISA. ANGPTL4 concentration was statistically significantly higher in patients with LP compared to the control group (p < 0.01); moreover, it was significantly higher than in patients with psoriasis and vitiligo (p < 0.001, p < 0.01, respectively). There was no statistically significant difference in ANGPTL4 concentration between patients with psoriasis or vitiligo and controls. There was no correlation between ANGPTL4 concentration and age or BMI in all study groups. There was a positive correlation between ANGPTL4 concentration and fasting glucose (R = 0.43) and AST activity (R = 0.39) in psoriatic patients and ALT activity in patients with vitiligo (R = 0.44). ANGPTL4 could be a potential marker of metabolic complications in patients with LP, especially CAD. Perhaps patients with LP are more prone to CAD compared to the other two dermatoses, which requires further research.

Recent Updates in Hypertriglyceridemia Management for Cardiovascular Disease Prevention

PURPOSE OF REVIEW

Mounting evidence continues to support the causal role of triglyceride-rich lipoproteins (TRL) in the development of atherosclerotic cardiovascular disease (ASCVD). Substantial residual ASCVD risk remains among high-risk patients who have elevated triglycerides despite reduction in low-density lipoprotein cholesterol (LDL-C) with statin therapy. Ongoing research efforts have focused on evaluating triglyceride-lowering therapies among patients with hypertriglyceridemia.

RECENT FINDINGS

The REDUCE-IT trial showed that the addition of icosapent ethyl, a highly purified form of eicosapentaenoic acid (EPA), can reduce vascular events among statin-treated individuals with elevated triglycerides who have either clinical ASCVD or diabetes plus another risk factor. Although additional evidence for EPA has emerged from other trials, conflicting results have been reported by subsequent trials that tested different omega-3 fatty acid formulations. Randomized clinical trials have not demonstrated incremental ASCVD benefit of fibrates on background of statin therapy, but fibrates are used to help prevent pancreatitis in patients with severe hypertriglyceridemia. Selective inhibitors of apolipoprotein C-III (apoC3) and angiopoietin-like protein 3 (ANGPTL3), proteins that are involved in metabolism of TRLs by regulating lipoprotein lipase, have been tested in selected patient populations and showed significant reduction in triglyceride and LDL-C levels. Statin therapy continues to be the cornerstone of pharmacologic reduction of cardiovascular risk. High-dose EPA in the form of icosapent ethyl has been demonstrated to have cardiovascular benefit on top of statins in persons with elevated triglycerides at high ASCVD risk. Ongoing clinical trials are evaluating novel selective therapies such as apoC3 and ANGPTL3 inhibitors.

The Progression of Treatment for Refractory Hypercholesterolemia: Focus on the Prospect of Gene Therapy

Refractory hypercholesterolemia (RH), including homozygous familial hypercholesterolemia (HoFH) and compound heterozygous familial hypercholesterolemia, is characterized by high levels of low-density lipoprotein cholesterol (LDL-C) despite existing cholesterol-lowering methods at maximal tolerable doses. Patients with RH have early onset and higher risk of atherosclerotic cardiovascular disease (ASCVD) under insufficient treatment. Therefore, it is urgent to seek new therapies to maintain the blood lipids in refractory hyperlipidemia at normal levels. Currently, new cholesterol-lowering strategies are on the market, not only at the protein level [i.e., bempedoic acid (inhibiting ATP-citrate lyase), alirocumab and evolocumab (monoclonal antibodies against PCSK9), evinacumab (monoclonal antibody against ANGPTL3)] but also at the transcript level [i.e., mipomersen (antisense oligonucleotide inhibiting ApoB), inclisiran (siRNA targeting PCSK9)], providing more options for RH patients to achieve their lipid-lowering targets. More RNA-based therapies targeting RH-related genes have been designed for the treatment. However, for a proportion of patients, especially those with LDLR deficiency, the available treatments are still insufficient. More recently, emerging genome engineering based on CRISPR/Cas9 techniques, and advanced delivery technologies such as lentiviral vectors, adenoviral vectors, adeno-associated viral vectors, lipid nanoparticles, and exosomes are being rapidly developed and implemented as novel therapies for RH. Gene therapy targeting RH-related genes has been successfully conducted in cells, mice, and non-human primates with high efficacy in lipid lowering and good tolerability. Especially the new generation of genome editing technique, base editing, performed in vivo with ideal lipid-lowering effect and limited occurrence of unwanted results. Excitingly, a phase I/II clinical study of LDLR gene replacement has been recently completed in RH patients, likely to be employed in clinical practice in the future. Furthermore, new targets for cholesterol reduction such as REV-ERB, G protein-coupled receptor, Ubiquitin specific peptidase 20 are continually being developed. This narrative review updates recent advances in treatment for RH, summarizes related clinical trials and preclinical studies, especially on the prospect of gene therapy.

Non-coding RNA-Associated Therapeutic Strategies in Atherosclerosis

Atherosclerosis has been the main cause of disability and mortality in the world, resulting in a heavy medical burden for all countries. It is widely known to be a kind of chronic inflammatory disease in the blood walls, of which the key pathogenesis is the accumulation of immunologic cells in the lesion, foam cells formation, and eventually plaque rupture causing ischemia of various organs. Non-coding RNAs (ncRNAs) play a vital role in regulating the physiologic and pathophysiologic processes in cells. More and more studies have revealed that ncRNAs also participated in the development of atherosclerosis and regulated cellular phenotypes such as endothelial dysfunction, leukocyte recruitment, foam cells formation, and vascular smooth muscle cells phenotype-switching and apoptosis. Given the broad functions of ncRNAs in atherogenesis, they have become potential therapeutic targets. Apart from that, ncRNAs have become powerful blueprints to design new drugs. For example, RNA interference drugs were inspired by small interfering RNAs that exist in normal cellular physiologic processes and behave as negative regulators of specific proteins. For instance, inclisiran is a kind of RNAi drug targeting PCKS9 mRNA, which can lower the level of LDL-C and treat atherosclerosis. We introduce some recent research progresses on ncRNAs related to atherosclerotic pathophysiologic process and the current clinical trials of RNA drugs pointed at atherosclerosis.

RNA-based therapy in the management of lipid disorders: a review

This review focuses on antisense oligonucleotides and small interfering ribonucleic acid therapies approved or under development for the management of lipid disorders. Recent advances in RNA-based therapeutics allow tissue-specific targeting improving safety. Multiple potential target proteins have been identified and RNA-based therapeutics have the potential to significantly improve outcomes for patients with or at risk for atherosclerotic cardiovascular disease. The advantages of RNA-based lipid modifying therapies include the ability to reduce the concentration of almost any target protein highly selectively, allowing for more precise control of metabolic pathways than can often be achieved with small molecule-based drugs. RNA-based lipid modifying therapies also make it possible to reduce the expression of target proteins for which there are no small molecule inhibitors. RNA-based therapies can also reduce pill burden as their administration schedule typically varies from weekly to twice yearly injections. The safety profile of most current RNA-based lipid therapies is acceptable but adverse events associated with various therapies targeting lipid pathways have included injection site reactions, inflammatory reactions, hepatic steatosis and thrombocytopenia. While the body of evidence for these therapies is expanding, clinical experience with these therapies is currently limited in duration and the results of long-term studies are eagerly awaited.

A Tale of Two New Targets for Hypertriglyceridaemia: Which Choice of Therapy?

Angiopoietin-like protein 3 (ANGPTL3) and apolipoprotein C-III (apoC-III) are novel metabolic targets for correcting hypertriglyceridaemia (HTG). As a background to their potential clinical use, we review the metabolic aetiology of HTG, particular abnormalities in triglyceride-rich lipoproteins (TRLs) and their role in atherosclerotic cardiovascular disease (ASCVD) and acute pancreatitis. Molecular and cardiometabolic aspects of ANGPTL3 and apoC-III, as well as inhibition of these targets with monoclonal antibody and nucleic acid therapies, are summarized as background information to descriptions and analyses of recent clinical trials. These studies suggest that ANGPTL3 and apoC-III inhibitors are equally potent in lowering elevated plasma triglycerides and TRLs across a wide range of concentrations, with possibly greater efficacy with inhibition of apoC-III. ANGPTL3 inhibition may, however, have the advantage of greater lowering of plasma LDL cholesterol and could specifically address elevated LDL cholesterol in familial hypercholesterolaemia refractory to standard drug therapies. Large clinical outcome trials in relevant populations are still required to confirm the long-term efficacy, safety and cost effectiveness of these potent agents for mitigating the complications of HTG. Beyond targeting severe chylomicronaemia in the prevention of acute pancreatitis, both agents could be useful in addressing residual risk of ASCVD due to TRLs in patients receiving best standard of care, including behavioural modifications, statins, ezetimibe, fibrates and proprotein convertase subtilisin/kexin type 9 inhibitors.

Correlation between betatrophin/angiogenin-likeprotein3/lipoprotein lipase pathway and severity of coronary artery disease in Kazakh patients with coronary heart disease

BACKGROUND

The results of previous animal experiments and clinical studies have shown that there is a correlation between expression of betatrophin and blood lipid levels. However, there are still differences studies on the correlation and interaction mechanism between betatrophin, angiogenin-likeprotein3 (ANGPTL3) and lipoprotein lipase (LPL). In our previous studies, we found an increase in serum ANGPTL3 Levels in Chinese patients with coronary heart disease (CHD). Therefore, we retrospectively studied Kazakh CHD patients.

AIM

To explore the correlation between the betatrophin/ANGPTL3/LPL pathway and severity of coronary artery disease (CAD) in patients with CHD.

METHODS

Nondiabetic patients diagnosed with CHD were selected as the case group; 79 were of Kazakh descent and 72 were of Han descent. The control groups comprised of 61 Kazakh and 65 Han individuals. The serum levels of betatrophin and LPL were detected by enzyme-linked immunosorbent assay (ELISA), and the double antibody sandwich ELISA was used to detect serum level of ANGPTL3. The levels of triglycerides, total cholesterol, and fasting blood glucose in each group were determined by an automatic biochemical analyzer. At the same time, the clinical baseline data of patients in each group were included.

RESULTS

Betatrophin, ANGPTL3 and LPL levels of Kazakh patients were significantly higher than those of Han patients (P = 0.031, 0.038, 0.021 respectively). There was a positive correlation between the Gensini score and total cholesterol (TC), triglycerides (TG), low- density lipoprotein cholesterol (LDL-C), betatrophin, and LPL in Kazakh patients (r = 0.204, 0.453, 0.352, 0.471, and 0.382 respectively), (P = 0.043, 0.009, 0.048, 0.001, and P < 0.001 respectively). A positive correlation was found between the Gensini score and body mass index (BMI), TC, TG, LDL-C, LPL, betatrophin in Han patients (r = 0.438, 0.195, 0.296, 0.357, 0.328, and 0.446 respectively), (P = 0.044, 0.026, 0.003, 0.20, 0.004, and P < 0.001). TG and betatrophin were the risk factors of coronary artery disease in Kazakh patients, while BMI and betatrophin were the risk factors in Han patients.

CONCLUSION

There was a correlation between the betatrophin/ANGPTL3/LPL pathway and severity of CAD in patients with CHD.

Managing of Dyslipidaemia Characterized by Accumulation of Triglyceride-Rich Lipoproteins

Purpose of Review

The accumulation of triglyceride-rich lipoproteins (TRLs) in plasma in patients with familial chylomicronaemia syndrome (FCS) or severe hypertriglyceridemia is associated with an increased risk of potentially life-threatening pancreatitis. Elevated TRL levels have also been suggested to contribute to atherosclerotic cardiovascular disease (ASCVD). This review provides the latest progress that has been made in this field of research.

Recent Findings

Apolipoprotein C-III and angiopoietin-like protein 3 play key roles in the metabolism of TRLs. Targeting their production in the liver or their presence in the circulation effectively reduces triglycerides in patients with FCS or severe hypertriglyceridemia. Attempts to reduce triglyceride synthesis in the small intestine have been halted. Early studies with a fibroblast growth factor 21 agonist have shown to reduce plasma triglycerides and hepatic steatosis and improve glucose homeostasis.

Summary

New drugs have recently been shown to effectively reduce plasma triglycerides which render hope for treating the risk of pancreatitis. Studies that have just been initiated will learn whether this unmet clinical will be met. It is too early to evaluate the potential of these drugs to reduce the risk of atherosclerosis through the reduction of triglycerides.

Effects of Alirocumab on Triglyceride Metabolism: A Fat-Tolerance Test and Nuclear Magnetic Resonance Spectroscopy Study

Background: PCSK9 antibodies strongly reduce LDL cholesterol. The effects of PCSK9 antibodies on triglyceride metabolism are less pronounced. The present study aimed to investigate in detail the effects of alirocumab on triglycerides, triglyceride-rich lipoproteins, and lipase regulators. Methods: A total of 24 patients with an indication for treatment with PCSK9 antibodies were recruited. There were two visits at the study site: the first before initiation of treatment with alirocumab and the second after 10 weeks of treatment. Fat-tolerance tests, nuclear magnetic resonance spectroscopy, and enzyme-linked immunosorbent assays were performed to analyze lipid metabolism. Results: A total of 21 participants underwent the first and second investigation. Among these, two participants only received alirocumab twice and 19 patients completed the trial per protocol. All of them had atherosclerotic vascular disease. There was no significant effect of alirocumab treatment on fasting triglycerides, post-prandial triglycerides, or lipoprotein-lipase regulating proteins. Total, large, and small LDL particle concentrations decreased, while the HDL particle concentration increased (all p < 0.001). Mean total circulating PCSK9 markedly increased in response to alirocumab treatment (p < 0.001). Whereas PCSK9 increased more than three-fold in all 19 compliant patients, it remained unchanged in those two patients with two injections only. Conclusion: Significant effects of alirocumab on triglyceride metabolism were not detectable in the ALIROCKS trial. The total circulating PCSK9 concentration might be a useful biomarker to differentiate non-adherence from non-response to PCSK9 antibodies.

Unravelling lipoprotein metabolism with stable isotopes: tracing the flow

Dysregulated lipoprotein metabolism is a major cause of atherosclerotic cardiovascular disease (ASCVD). Use of stable isotope tracers and compartmental modelling have provided deeper understanding of the mechanisms underlying lipid disorders in patients at high risk of ASCVD, including familial hypercholesterolemia (FH), elevated lipoprotein(a) [Lp(a)] and metabolic syndrome (MetS). In patients with FH, deficiency in low-density lipoprotein (LDL) receptor activity not only impairs the catabolism of LDL, but also induces hepatic overproduction and decreases catabolism of triglyceride-rich lipoproteins (TRLs). Patients with elevated Lp(a) are characterized by increased hepatic secretion of Lp(a) particles. Atherogenic dyslipidemia in MetS patients relates to a combination of overproduction of very-low density lipoprotein-apolipoprotein (apo) B-100, decreased catabolism of apoB-100-containing particles, and increased catabolism of high-density lipoprotein-apoA-I particles, as well as to impaired clearance of TRLs in the postprandial state. Kinetic studies show that weight loss, fish oils, statins and fibrates have complementary modes of action that correct atherogenic dyslipidemia. Defining the kinetic mechanisms of action of proprotein convertase subtilisin/kexin type 9 and angiopoietin-like 3 inhibitors on lipid and lipoprotein mechanism in dyslipidemic subjects will further our understanding of these therapies in decreasing the development of ASCVD. "Everything changes but change itself. Everything flows and nothing remains the same... You cannot step twice into the same river, for other waters and yet others go flowing ever on." Heraclitus (c.535- c. 475 BCE).

Apolipoprotein B and Cardiovascular Disease: Biomarker and Potential Therapeutic Target

Apolipoprotein (apo) B, the critical structural protein of the atherogenic lipoproteins, has two major isoforms: apoB48 and apoB100. ApoB48 is found in chylomicrons and chylomicron remnants with one apoB48 molecule per chylomicron particle. Similarly, a single apoB100 molecule is contained per particle of very-low-density lipoprotein (VLDL), intermediate density lipoprotein, LDL and lipoprotein(a). This unique one apoB per particle ratio makes plasma apoB concentration a direct measure of the number of circulating atherogenic lipoproteins. ApoB levels indicate the atherogenic particle concentration independent of the particle cholesterol content, which is variable. While LDL, the major cholesterol-carrying serum lipoprotein, is the primary therapeutic target for management and prevention of atherosclerotic cardiovascular disease, there is strong evidence that apoB is a more accurate indicator of cardiovascular risk than either total cholesterol or LDL cholesterol. This review examines multiple aspects of apoB structure and function, with a focus on the controversy over use of apoB as a therapeutic target in clinical practice. Ongoing coronary artery disease residual risk, despite lipid-lowering treatment, has left patients and clinicians with unsatisfactory options for monitoring cardiovascular health. At the present time, the substitution of apoB for LDL-C in cardiovascular disease prevention guidelines has been deemed unjustified, but discussions continue.

Non-stenotic Carotid Plaques in Embolic Stroke of Unknown Source

Embolic stroke of unknown source (ESUS) represents one in five ischemic strokes. Ipsilateral non-stenotic carotid plaques are identified in 40% of all ESUS. In this narrative review, we summarize the evidence supporting the potential causal relationship between ESUS and non-stenotic carotid plaques; discuss the remaining challenges in establishing the causal link between non-stenotic plaques and ESUS and describe biomarkers of potential interest for future research. In support of the causal relationship between ESUS and non-stenotic carotid plaques, studies have shown that plaques with high-risk features are five times more prevalent in the ipsilateral vs. the contralateral carotid and there is a lower incidence of atrial fibrillation during follow-up in patients with ipsilateral non-stenotic carotid plaques. However, non-stenotic carotid plaques with or without high-risk features often coexist with other potential etiologies of stroke, notably atrial fibrillation (8.5%), intracranial atherosclerosis (8.4%), patent foramen ovale (5-9%), and atrial cardiopathy (2.4%). Such puzzling clinical associations make it challenging to confirm the causal link between non-stenotic plaques and ESUS. There are several ongoing studies exploring whether select protein and RNA biomarkers of plaque progression or vulnerability could facilitate the reclassification of some ESUS as large vessel strokes or help to optimize secondary prevention strategies.

Targeting angiopoietin-like 3 in atherosclerosis: From bench to bedside

Atherosclerotic cardiovascular disease (ASCVD) is the largest cause of morbidity and mortality worldwide. Lipid-lowering therapies are the current major cornerstone of ASCVD management. Statins, ezetimibe, fibrates and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors effectively reduce the plasma low-density lipoprotein cholesterol (LDL-C) level in most individuals at risk of atherosclerosis. Still, some patients (such as those with homozygous familial hypercholesterolaemia), who do not respond to standard therapies, and other patients who cannot take these agents, remain at a high risk of ASCVD. In recent years there has been tremendous progress in understanding the mechanism and efficacy of lipid-lowering strategies. Apart from the recently approved PCSK9 and ATP citrate lyase inhibitors, angiopoietin-like 3 (ANGPTL3) is another potential target for the treatment of dyslipidaemia and its clinical sequalae of atherosclerosis. ANGPTL3 is a pivotal modulator of plasma triglycerides (TG), LDL-C and high-density lipoprotein cholesterol (HDL-C) levels, achieved by inhibiting the activities of lipoprotein lipase and endothelial lipase. Familial combined hypolipidaemia is derived from the Angptl3 loss-of-function mutations, which leads to low levels of LDL-C, HDL-C and TG, and has a 34% decreased risk of ASCVD compared with non-carriers. To date, monoclonal antibodies (evinacumab) and antisense oligonucleotides against ANGPTL3 have been investigated in clinical trials for dyslipidaemia therapy. Herein, we review the biology and function of ANGPTL3, as well as the latest developments of ANGPTL3-targeted therapies. We also summarize evidence from basic research to clinical trials, with the aim of providing novel insights into the biological functions of ANGPTL3 and related targeted therapies.

Evinacumab for treatment of familial hypercholesterolemia

Introduction: Familial hypercholesterolemia (FH) is characterized by lifelong elevation of low-density lipoprotein cholesterol (LDL-C), early onset coronary atherosclerosis, and premature death. FH is underdiagnosed and undertreated, but requires aggressive LDL-C-lowering to prevent complications. Current treatment strategies such as lifestyle modification and numerous LDL-C-lowering medications are often insufficient to achieve lipid goals in FH.Areas covered: Angiopoietin-like 3 protein (ANGPTL3) is intricately involved in lipid metabolism. Loss-of-function mutations in ANGPTL3 are associated with panhypolipidemia and reduced coronary atherosclerosis. Evinacumab, a fully human monoclonal antibody, inhibits ANGPTL3 and reduces multiple lipoprotein fractions ~50%, including LDL-C. The use of evinacumab within the FH population is described as well as its regulatory journey to an approved therapeutic.Expert opinion: Evinacumab, with its capacity to lower multiple lipoprotein fractions, particularly LDL-C, independently of LDLR function has potential to revolutionize treatment for FH patients. Current FDA-approval is only for homozygous FH (HoFH), arguably the most impactful indication, but use in other lipid disorders is under investigation. The short-term tolerability of evinacumab is very good, with infrequent, mild, and transient adverse events; however, long-term safety data are needed. The high cost and requirement for intravenous administration may limit adoption of evinacumab, but dramatic LDL-C-lowering and need for new therapeutic options for HoFH will drive interest.

Emerging roles of angiopoietin-like proteins in inflammation: Mechanisms and potential as pharmacological targets

Angiopoietin-like proteins (ANGPTLs), a family of eight secreted glycoproteins termed ANGTPL1-8, are involved in angiogenesis, lipid metabolism, cancer progression, and inflammation. Their roles in regulating lipid metabolism have been intensively studied, as some ANGPTLs are promising pharmacological targets for hypertriglyceridemia and associated cardiovascular disease. Recently, the emerging roles of ANGPTLs in inflammation have attracted great attention. First, elevated levels of multiple circulating ANGPTLs in inflammatory diseases make them potential disease biomarkers. Second, multiple ANGPTLs regulate acute or chronic inflammation via various mechanisms, including triggering inflammatory signaling through their action as ligands for integrin or forming homo- /hetero-oligomers to regulate signal transduction via extra- or intracellular mechanisms. As dysregulation of the inflammatory response is a critical trigger in many diseases, understanding the roles of ANGPTLs in inflammation will aid in drug/therapy development. Here, we summarize the roles, mechanisms, and potential therapeutic values for ANGPTLs in inflammation and inflammatory diseases.

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

Dyslipidemia is characterized by increasing plasma levels of low-density lipoprotein-cholesterol (LDL-C), triglycerides (TGs) and TG-rich lipoproteins (TGRLs) and is a major risk factor for the development of atherosclerotic cardiovascular disorders (ASCVDs). It is important to understand the metabolic mechanisms underlying dyslipidemia to develop effective strategies against ASCVDs. Angiopoietin-like 3 (ANGPTL3), a member of the angiopoietin-like protein family exclusively synthesized in the liver, has been demonstrated to be a critical regulator of lipoprotein metabolism to inhibit lipoprotein lipase (LPL) activity. Genetic, biochemical, and clinical studies in animals and humans have shown that loss of function, inactivation, or downregulated expression of ANGPTL3 is associated with an obvious reduction in plasma levels of TGs, LDL-C, and high-density lipoprotein-cholesterol (HDL-C), atherosclerotic lesions, and the risk of cardiovascular events. Therefore, ANGPTL3 is considered an alternative target for lipid-lowering therapy. Emerging studies have focused on ANGPTL3 inhibition via antisense oligonucleotides (ASOs) and monoclonal antibody-based therapies, which have been carried out in mouse or monkey models and in human clinical studies for the management of dyslipidemia and ASCVDs. This review will summarize the current literature on the important role of ANGPTL3 in controlling lipoprotein metabolism and dyslipidemia, with an emphasis on anti-ANGPTL3 therapies as a potential strategy for the treatment of dyslipidemia and ASCVDs.

The Mechanism of Oral Melatonin Ameliorates Intestinal and Adipose Lipid Dysmetabolism Through Reducing Escherichia Coli-Derived Lipopolysaccharide

BACKGROUND & AIMS

Gut microbiota have been reported to be sensitive to circadian rhythms and host lipometabolism, respectively. Although melatonin-mediated beneficial efforts on many physiological sites have been revealed, the regulatory actions of oral melatonin on the communication between gut microbiota and host are still not clear. Angiopoietin-like 4 (ANGPTL4) has been shown to be strongly responsible for the regulation of systemic lipid metabolism. Herein, we identified that oral melatonin improved lipid dysmetabolism in ileum and epididymal white adipose tissue (eWAT) via gut microbiota and ileac ANGPTL4.

METHODS

Analyses of jet-lag (JL) mice, JL mice with oral melatonin administration (JL+MT), and the control for mRNA and protein expression regarding lipid uptake and accumulation in ileum and eWAT were made. Gut microbiome sequencing and experimental validation of target strains were included. Functional analysis of key factors/pathways in the various rodent models, including the depletion of gut microbiota, mono-colonization of Escherichia coli, and other genetic intervention was made. Analyses of transcriptional regulation and effects of melatonin on E coli-derived lipopolysaccharide (LPS) in vitro were made.

RESULTS

JL mice have a higher level of ileal lipid uptake, fat accumulation in eWAT, and lower level of circulating ANGPTL4 in comparison with the control mice. JL mice also showed a significantly higher abundance of E coli and LPS than the control mice. Conversely, oral melatonin supplementation remarkably reversed these phenotypes. The test of depletion of gut microbiota further demonstrated that oral melatonin-mediated improvements on lipometabolism in JL mice were dependent on the presence of gut microbiota. By mono-colonization of E coli, LPS has been determined to trigger these changes similar to JL. Furthermore, we found that LPS served as a pivotal link that contributed to activating toll-like receptor 4 (TLR4)/signal transducer and activator of transcription 3 (STAT3_/REV-ERBα) signaling to up-regulate nuclear factor interleukin-3-regulated protein (NFIL3) expression, resulting in increased lipid uptake in ileum. In MODE-K cells, the activation of NFIL3 has further been shown to inhibit ANGPTL4 transcription, which is closely associated with lipid uptake and transport in peripheral tissues. Finally, we confirmed that melatonin inhibited LPS via repressing the expression of LpxC in E coli.

CONCLUSIONS

Overall, oral melatonin decreased the quantity of E coli-generated LPS, which alleviated NFIL3-induced transcriptional inhibition of ANGPTL4 through TLR4/IL-22/STAT3 signaling in ileum, thereby resulting in the amelioration of ileal lipid intake and lower fat accumulation in eWAT. These results address a novel regulation of oral melatonin originating from gut microbiota to host distal tissues, suggesting that microbe-generated metabolites are potential therapies for melatonin-mediated improvement of circadian rhythm disruption and related metabolic syndrome.

Angiopoietin-like proteins in atherosclerosis

Atherosclerosis, as a chronic inflammatory disease within the arterial wall, is a leading cause of morbidity and mortality worldwide due to its role in myocardial infarction, stroke and peripheral artery disease. Additional evidence is emerging that the angiopoietin-like (ANGPTL) family of proteins participate in the pathology of this disease process via endothelial dysfunction, inflammation, dyslipidemia, calcification, foam cell formation and platelet activation. This review summarizes current knowledge on the ANGPTL family of proteins in atherosclerosis related pathological processes. Moreover, the potential value of ANGPTL family proteins as predictive biomarkers in atherosclerosis is discussed. Given the attractive role of ANGPTL3, ANGPTL4, ANGPTL8 in atherosclerotic dyslipidemia via regulation of lipoprotein lipase (LPL), antisense oligonucleotide or/and monoclonal antibody-based inactivation of these proteins represent potential atherosclerotic therapies.

Beyond Statins and PCSK9 Inhibitors: Updates in Management of Familial and Refractory Hypercholesterolemias

PURPOSE OF REVIEW

Elevation in apolipoprotein B-containing lipoproteins in the blood is a cause of atherosclerosis. Statins have changed the preventive cardiology scenario, and more recently monoclonal proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors were added as robust agents to further reduce pro-atherogenic lipoproteins and therefore prevent cardiovascular events. However, despite this many dyslipidemic individuals persist with inadequate LDL-C levels and still at risk. The purpose of this review was to discuss current status and describe advances in therapies beyond statins and monoclonal PCSK9 inhibitors.

RECENT FINDINGS

Ezetimibe and lomitapide have been used for many years to further reduce LDL-C and longer term data reinforce their safety. Bempedoic acid, an inhibitor of adenosine triphosphate-citrate lyase, has been shown to add LDL-C reduction on top of statins and ezetimibe, furthermore it may be an alternative for statin intolerant patients. Inclisiran is a small interfering ribonucleic acid inhibitor that reduces the hepatic production of PCSK9 that induces robust LDL-C lowering, similar to monoclonal antibodies, with the advantage of 2 or 3 injections per year. So far, no safety signs were seen with its use. Evinacumab, a monoclonal antibody that binds angiopoietin-like protein 3 (ANGPTL3), induces robust LDL-C lowering in either homozygous familial hypercholesterolemia or severe hypercholesterolemia patients with good tolerability. Many high-risk individuals persist with elevated LDL-C, newer medications further lower LDL-C on top of standard lipid-lowering therapies and are well tolerated. Ongoing clinical trials may prove if these novel medications will reduce cardiovascular events with safety.

Lipid Lowering Drugs: Present Status and Future Developments

Purpose of review

Based on the recent data of the DA VINCI study, it is clear that, besides utilization of statins, there is a need to increase non-statin lipid lowering approaches to reduce the cardiovascular burden in patients at highest risk.

Recent findings

For hypercholesterolemia, the small synthetic molecule bempedoic acid has the added benefit of selective liver activation, whereas inclisiran, a hepatic inhibitor of the PCSK9 synthesis, has comparable effects with PCSK9 monoclonal antibodies. For hypertriglyceridemia, cardiovascular benefit has been achieved by the use of icosapent ethyl, whereas results with pemafibrate, a selective agonist of PPAR-α, are eagerly awaited. In the era of RNA-based therapies, new options are offered to dramatically reduce levels of lipoprotein(a) (APO(a)L_RX) and of triglycerides (ANGPTL3L_RX and APOCIII-L_Rx).

Summary

Despite the demonstrated benefits of statins, a large number of patients still remain at significant risk because of inadequate LDL-C reduction or elevated blood triglyceride-rich lipoproteins or lipoprotein(a). The area of lipid modulating agents is still ripe with ideas and major novelties are to be awaited in the next few years.

ANGPLT3 in cardio-metabolic disorders

Dyslipidemia is associated with numerous health problems that include the combination of insulin resistance, hypertension and obesity, which is always grouped together asmetabolic syndrome. Given that metabolic syndrome leads to a high mortality and poses serious risks to human health worldwide, it is vital to explore the mechanisms whereby dyslipidemia modulates the risk and the severity of cardio-metabolic disorders. Recently, a specific secretory protein family, named angiopoietin-like protein (ANGPTL), is considered as one of the significant biomarkers which facilitate the development of angiogenesis. Among the eight proteins of ANGPTL family, ANGPTL3 has been demonstrated as an essential modulator of lipid catabolism within circulation by inhibiting the activity of lipoprotein lipase (LPL) and endothelial lipase (EL). Consistent with these notions, mice with ANGPTL3 gene-deficiency presented reduced circulating levels of low density lipoprotein cholesterol (LDL-C) and lower risk of atherosclerosis. On the other hand, participants carrying homozygous loss-of function (LOF) mutation in ANGPTL3 gene also displayed lower circulating LDL-C levels and atherosclerotic risk. In the current review, we summarized the recent understanding of ANGPTL3 in controlling the risk and the development of dyslipidemia and its related cardio-metabolic disorders. Moreover, we also provided the perspectives which potentially suggested that ANGPTL3 could be considered as a promising target in treating metabolic syndrome.

Personalized medicine in lipid-modifying therapy

The choice of lipid-modifying treatment is largely based on the absolute level of cardiovascular risk and baseline lipid profile. Statins are the first-line treatment for most patients requiring reduction of low-density-lipoprotein cholesterol (LDL-C) and ezetimibe and proprotein convertase subtilisin/kexin type 9 inhibitors can be added to reach LDL-C targets. Statins have some adverse effects that are somewhat predictable based on phenotypic and genetic factors. Fibrates or omega-3 fatty acids can be added if triglyceride levels remain elevated. The RNA-targeted therapeutics in development offer the possibility of selective liver targeting for specific lipoproteins such as lipoprotein(a) and long-term reduction of LDL-C with infrequent administration of a small-interfering RNA may help to overcome the problem of adherence to therapy.

Familial hypertriglyceridemia: an entity with distinguishable features from other causes of hypertriglyceridemia

BACKGROUND

Familial hypertriglyceridemia (FHTG) is a partially characterized primary dyslipidemia which is frequently confused with other forms hypertriglyceridemia. The aim of this work is to search for specific features that can help physicians recognize this disease.

METHODS

This study included 84 FHTG cases, 728 subjects with common mild-to-moderate hypertriglyceridemia (CHTG) and 609 normotriglyceridemic controls. All subjects underwent genetic, clinical and biochemical assessments. A set of 53 single nucleotide polymorphisms (SNPs) previously associated with triglycerides levels, as well as 37 rare variants within the five main genes associated with hypertriglyceridemia (i.e. LPL, APOC2, APOA5, LMF1 and GPIHBP1) were analyzed. A panel of endocrine regulatory proteins associated with triglycerides homeostasis were compared between the FHTG and CHTG groups.

RESULTS

Apolipoprotein B, fibroblast growth factor 21(FGF-21), angiopoietin-like proteins 3 (ANGPTL3) and apolipoprotein A-II concentrations, were independent components of a model to detect FHTG compared with CHTG (AUC 0.948, 95%CI 0.901-0.970, 98.5% sensitivity, 92.2% specificity, P < 0.001). The polygenic set of SNPs, accounted for 1.78% of the variance in triglyceride levels in FHTG and 6.73% in CHTG.

CONCLUSIONS

The clinical and genetic differences observed between FHTG and CHTG supports the notion that FHTG is a unique entity, distinguishable from other causes of hypertriglyceridemia by the higher concentrations of insulin, FGF-21, ANGPTL3, apo A-II and lower levels of apo B. We propose the inclusion of these parameters as useful markers for differentiating FHTG from other causes of hypertriglyceridemia.

Hepatokines and metabolism: Deciphering communication from the liver

Background

The liver is a key regulator of systemic energy homeostasis and can sense and respond to nutrient excess and deficiency through crosstalk with multiple tissues. Regulation of systemic energy homeostasis by the liver is mediated in part through regulation of glucose and lipid metabolism. Dysregulation of either process may result in metabolic dysfunction and contribute to the development of insulin resistance or fatty liver disease.

Scope of review

The liver has recently been recognized as an endocrine organ that secretes hepatokines, which are liver-derived factors that can signal to and communicate with distant tissues. Dysregulation of liver-centered inter-organ pathways may contribute to improper regulation of energy homeostasis and ultimately metabolic dysfunction. Deciphering the mechanisms that regulate hepatokine expression and communication with distant tissues is essential for understanding inter-organ communication and for the development of therapeutic strategies to treat metabolic dysfunction.

Major conclusions

In this review, we discuss liver-centric regulation of energy homeostasis through hepatokine secretion. We highlight key hepatokines and their roles in metabolic control, examine the molecular mechanisms of each hepatokine, and discuss their potential as therapeutic targets for metabolic disease. We also discuss important areas of future studies that may contribute to understanding hepatokine signaling under healthy and pathophysiological conditions.