👤 Alberico Luigi Catapano

Inhibition of angiopoietin-like protein 3 (ANGPTL3) has been proposed as a promising approach to reduce residual cardiovascular risk. We conducted a meta-analysis of randomized controlled trials (RCTs) to provide a comprehensive evaluation of the metabolic effects of ANGPTL3 inhibitors. Databases (PubMed, EMBASE, Web of Science, CENTRAL, ClinicalTrials.gov) were searched from inception to July 2025. Eligible studies were RCTs comparing ANGPTL3 inhibitors against placebo. Outcomes included triglycerides (TG), LDL-C, apolipoprotein B (ApoB), non-high-density lipoprotein cholesterol (non-HDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), very-low-density lipoprotein cholesterol (VLDL-C), apolipoprotein A1 (ApoA1), apolipoprotein C3 (ApoC3), lipoprotein(a) (Lp(a)), remnant cholesterol (RC), ANGPTL3 and C-reactive protein (CRP). Pooled estimates of percentage change from baseline were obtained using fixed- and random-effects models. Subgroup analysis was performed based on the mechanism of action: monoclonal antibodies (mAbs, evinacumab), antisense oligonucleotides (ASOs, vupanorsen), and small interfering RNAs (siRNA, zodasiran and solbinsiran). Nine RCTs (1,254 participants) were included. ANGPTL3 inhibition significantly reduced TG (-47.1%), LDL-C (-21.6%), ApoB (-19.9%), non-HDL-C (-31.5%), TC (-32.8%), VLDL-C (-40.6%), and RC (-72.7%). Modest but consistent reductions were also observed in Lp(a) (-11.5%), ApoA1 (-18.3%), and ApoE (-16.4%). ANGPTL3 inhibitors markedly reduced circulating ANGPTL3 protein (-70.7%), with no significant effect on high-sensitivity CRP. Subgroup analyses demonstrated greater reductions in LDL-C, ApoB, non-HDL-C, and TC with evinacumab compared to the other groups, whereas small interfering RNAs produced more pronounced VLDL-C lowering compared with vupanorsen. ANGPTL3 inhibition offers broad lipid-lowering benefits, with particularly marked reductions in TG-rich lipoproteins. Show less

Many adults fail to achieve guideline-directed low-density lipoprotein cholesterol (LDL-C) goals on statin monotherapy, requiring additional nonstatin lipid-lowering medication. Enlicitide, an oral proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitor, lowered LDL-C by 60% compared with placebo; its efficacy compared with other oral nonstatin therapies has yet to be examined. This study assessed the efficacy of enlicitide, a novel oral PCSK9 inhibitor, vs other oral nonstatin therapies. In this phase 3, randomized, double-blind, active-comparator trial, statin-treated adults aged ≥18 years with LDL-C ≥55 mg/dL and a previous major atherosclerotic cardiovascular disease (ASCVD) event, or LDL-C ≥70 mg/dL if at intermediate to high risk for a first event, were randomized in 2:1:1:2 fashion to 20 mg enlicitide (n = 101), 180 mg bempedoic acid (n = 50), 10 mg ezetimibe (n = 50), or 180 mg bempedoic acid plus 10 mg ezetimibe (n = 100) once daily for 56 days. The primary endpoint was mean percentage change in LDL-C from baseline to day 56; secondary endpoints included mean percentage changes in apolipoprotein B (ApoB) and non-high-density lipoprotein cholesterol (nonHDL-C). Safety endpoints included overall adverse events (AEs) and discontinuations due to AEs. Among 301 randomized participants (mean age 64.4 years, 37% female, 98% receiving moderate- to high-intensity statin), 298 (99.0%) completed the trial. The mean percentage change in LDL-C from baseline to day 56 was -64.6% (95% CI: -68.3% to -60.9%) with enlicitide, -6.3% (95% CI: -13.5% to 0.8%) with bempedoic acid, -27.8% (95% CI: -32.3% to -23.4%) with ezetimibe, and -36.5% (95% CI: -40.8% to -32.2%) with bempedoic acid plus ezetimibe; enlicitide was superior to each comparator (all P < 0.001). Reductions in ApoB and nonHDL-C were also greater with enlicitide (all P < 0.001). Proportions of participants with AEs and discontinuations due to AEs were similar across treatment arms. In statin-treated adults with a history of a major ASCVD event or at increased risk for a first event, enlicitide achieved greater reductions in LDL-C, ApoB, and nonHDL-C than other oral nonstatin therapies, demonstrating its potential role as an important add-on option when LDL-C goals are not met with the use of statins alone. (A Study to Evaluate the Efficacy and Safety of Enlicitide Decanoate [MK-0616, Oral PCSK9 Inhibitor] Compared With Ezetimibe or Bempedoic Acid or Ezetimibe and Bempedoic Acid in Adults With Hypercholesterolemia [MK-0616-018] [CORALreef AddOn; NCT06450366). Show less

Enlicitide decanoate, an oral proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitor, was shown to reduce low-density lipoprotein (LDL) cholesterol levels in a phase 2 trial; longer-term data are needed. In this multinational, double-blind, randomized, placebo-controlled trial, we enrolled adults with a history of a major atherosclerotic cardiovascular disease event with an LDL cholesterol level of 55 mg per deciliter or higher and those who were at risk for a first atherosclerotic cardiovascular disease event with an LDL cholesterol level of 70 mg per deciliter or higher. Participants were assigned in a 2:1 ratio to receive enlicitide at a dose of 20 mg or placebo daily for 52 weeks. The primary end point was the mean percent change in LDL cholesterol level from baseline to week 24. Key secondary end points were the mean percent change in LDL cholesterol level at week 52 and the mean percent change in levels of non-high-density lipoprotein (non-HDL) cholesterol and apolipoprotein B and the percent change in lipoprotein(a) level at week 24. Of the 2909 participants in the intention-to-treat population, 1935 received enlicitide and 969 received placebo (5 did not receive enlicitide or placebo). The mean age of the participants was 63 years, and 39.3% were women. The mean (±SD) LDL cholesterol level at baseline was 96.1±38.9 mg per deciliter. The mean percent change in LDL cholesterol levels at week 24 was -57.1% (95% confidence interval [CI], -61.8 to -52.5) with enlicitide and 3.0% (95% CI, 0.9 to 5.1) with placebo, representing an adjusted between-group difference of -55.8 percentage points (95% CI, -60.9 to -50.7; P<0.001). The mean percent change in LDL cholesterol level at week 52, the mean percent changes in non-HDL cholesterol and apolipoprotein B levels at week 24, and the percent change in lipoprotein(a) levels at week 24 were significantly greater with enlicitide than with placebo (P<0.001 for all comparisons). The incidence of adverse events did not appear to differ between the groups. Among participants who had a history of or were at risk for a first atherosclerotic cardiovascular disease event, treatment with the oral PCSK9 inhibitor enlicitide resulted in significantly lower LDL cholesterol levels than placebo at 24 weeks. (Funded by MSD [Rahway, NJ]; CORALreef Lipids ClinicalTrials.gov number, NCT05952856.). Show less

Most patients with heterozygous familial hypercholesterolemia fail to achieve adequate low-density lipoprotein (LDL) cholesterol lowering. Here we carried out a randomized trial to test the safety and efficacy of obicetrapib, a highly selective cholesteryl ester transfer protein inhibitor that lowers LDL cholesterol levels in patients with heterozygous familial hypercholesterolemia and an LDL cholesterol level ≥70 mg dl Show less

Persons with heterozygous familial hypercholesterolemia (HeFH) are at increased risk of atherosclerotic cardiovascular disease due to lifelong elevated levels of low-density lipoprotein cholesterol (LDL-C). Many patients with HeFH do not achieve guideline-recommended LDL-C goals with the currently available lipid-lowering therapies. To evaluate the efficacy of enlicitide decanoate (an oral proprotein convertase subtilisin/kexin type 9 inhibitor) vs placebo in adults with HeFH requiring further lowering of LDL-C levels despite use of statin therapy. This phase 3, randomized clinical trial included persons aged 18 years or older with HeFH currently using lipid-lowering therapy (taking at least a moderate- or high-intensity statin) and either an LDL-C level of 55 mg/dL or greater and a history of major atherosclerotic cardiovascular disease or an LDL-C level of 70 mg/dL or greater without a history of major atherosclerotic cardiovascular disease. The trial was conducted at 59 sites across 17 countries; the first participant was screened on August 8, 2023, and the last follow-up visit occurred on April 7, 2025. Participants were randomized (2:1) to 20 mg of enlicitide (n = 202) or placebo (n = 101) once daily for 52 weeks. The primary outcome was the mean percentage change in LDL-C level at week 24. The secondary outcomes included the mean percentage change in LDL-C level at week 52, the mean percentage change at week 24 in levels of non-high-density lipoprotein cholesterol (non-HDL-C) and apolipoprotein B, and the median percentage change at week 24 in lipoprotein(a). Of the 303 participants (mean age, 52.4 [SD, 13.5] years; 51% were female) randomized, 293 (96.7%) completed the trial. The mean LDL-C level was 119.0 mg/dL (SD, 41.0 mg/dL) at baseline, all had statin current use (81.5% were taking a high-intensity statin), and 64.4% were taking ezetimibe. The mean percentage change in LDL-C level at week 24 was -58.2% in the enlicitide group vs 2.6% in the placebo group (between-group difference, -59.4% [95% CI, -65.6% to -53.2%]; P < .001). The mean percentage change in LDL-C level at week 52 was -55.3% in the enlicitide group vs 8.7% in the placebo group (between-group difference, -61.5% [95% CI, -69.4% to -53.7%]; P < .001). At week 24, the mean percentage change in non-HDL-C level was -52.3% in the enlicitide group vs 2.1% in the placebo group (between-group difference, -53.0% [95% CI, -58.5% to -47.4%]; P < .001), the mean percentage change in apolipoprotein B level was -48.2% vs 1.8%, respectively (between-group difference, -49.1% [95% CI, -54.0% to -44.3%]; P < .001), and the median percentage change in lipoprotein(a) level was -24.7% vs -1.6% (between-group difference, -27.5% [95% CI, -34.3% to -20.6%]; P < .001). The incidence of adverse events, serious adverse events, and study discontinuation due to adverse events was similar between groups. Among adults with HeFH, treatment with enlicitide was well tolerated and significantly reduced levels of LDL-C, apolipoprotein B, non-HDL-C, and lipoprotein(a). ClinicalTrials.gov Identifier: NCT05952869. Show less

To date, despite the new lipid-lowering drugs, some subjects do not reach LDL-cholesterol and/or lipoprotein(a) [Lp(a)] goals and lipoprotein apheresis (LA) plays a role in atherosclerosis prevention. The aim of this study is to paint a portrait of the current LA activity in Italy, collecting data via an electronic survey. Forty-seven centers were contacted, data from 142 patients (male 67%) were obtained from 15 sites. Two sites had discontinued LA treatment. In the active sites, a median of 17 [14-26] LA treatment/patient per year was performed; 7/13 sites used more than one LA system, with venous vascular access used in 87% of cases. High Lp(a) plasma concentrations (> 60 mg/dL or ≥ 145 nmol/L) were recorded in 73/142 patients; 14/36 homozygous familial hypercholesterolemia patients were on lomitapide or evinacumab therapy. The PORTRAIT survey would like to promote a network to better manage the patients on chronic LA. Show less

We aimed to compare the molecular and clinical characteristics of patients identified in Italy as affected by either familial chylomicronemia syndrome (FCS) or multifactorial chylomicronemia syndrome (MCS) and to assess the overall benefit of novel triglyceride-lowering therapies prescribed to these patients within the routine clinical care. From the national LIPIGEN-sHTG (Lipid Transport Disorders Italian Genetic Network-Severe Hypertriglyceridemia) registry, 169 patients (57 FCS, 51 MCS, 61 variant-negative, variant-negative MCS) were retrospectively analyzed. Data on clinical and genetic characteristics, medical history, and medications were collected. Peak triglyceride levels were used to define untreated lipid phenotypes. In FCS, 72% exhibited biallelic As compared with MCS, patients with FCS showed a more severe phenotype and higher prevalence of Show less

The causal role of LDL in atherosclerotic cardiovascular disease (ASCVD) is well established, but the contribution of HDL has proven more complex. CETP inhibitors were originally developed to increase HDL-cholesterol (HDL-C), but the failure of clinical trials and genetic evidence have changed our understanding of CETP biology. With the development of obicetrapib, a next-generation CETP inhibitor, there has been renewed interest in its therapeutic potential. This review summarizes the latest findings on CETP inhibition and highlights the evolving perspectives from lipid modulation to broader clinical applications. Clinical trials and Mendelian randomisation consistently show that increasing HDL-C alone does not reduce cardiovascular risk, while lowering apoB-containing lipoproteins is associated with benefit. Off-target effects, modest efficacy or insufficient follow-up limited previous CETP inhibitors. Obicetrapib, in contrast, achieves a significant LDL-C and apoB reduction, a marked HDL-C increase and favourable safety. Beyond ASCVD, CETP inhibition may also have an impact on diabetes risk, cognitive function and possibly other conditions, although data are still preliminary. The therapeutic focus has shifted from HDL-C elevation to apoB lowering as the determinant of cardiovascular benefit. Obicetrapib shows promise, with ongoing trials designed to define its role in ASCVD management. Show less

Atherogenic dyslipidemia is an important risk factor for cardiovascular disease (CVD) in patients with type 2 diabetes, obesity, and metabolic disorders. Statin therapy, the standard treatment for dyslipidemia management, falls short of controlling the residual risk of adverse cardiovascular events, even with good control of low-density lipoprotein cholesterol (LDL-C). Apolipoprotein B (apoB), in addition to non-high-density lipoprotein cholesterol (non-HDL-C), is considered a better measure of residual risk and a more comprehensive treatment target in atherogenic dyslipidemia. Fibrates in combination with statins represent a proven therapeutic modality for atherogenic dyslipidemia. Fibrates lower triglyceride-rich lipoproteins (TRL), TRL remnants, and small dense LDL particles while increasing HDL-C levels. However, only fenofibrate appears to reduce apoB, whereas gemfibrozil and pemafibrate do not. This leads to a reduction in atherogenic lipids, as measured by a significant decrease in apoB/non-HDL-C levels, and a corresponding reduction in CVD risk. Real-world efficacy studies and CVD outcome trials have shown that fenofibrate may be an option in combination with statins compared to other fibrates and is well tolerated. Additionally, evidence from real-world studies of the fenofibrate-statin combination in patients over a period of up to 20 years has dispelled safety concerns regarding long-term use of fenofibrate. Show less

Lipoprotein (a) [Lp(a)] is an independent and causal risk factor for atherosclerotic cardiovascular disease. In this study we aimed at assessing the effect of currently available lipid-lowering therapies (LLTs) on Lp(a) plasma levels. A meta-analysis was performed according to the PRISMA guidelines. Databases were searched up to May 2025. Inclusion criteria were: (1) randomized controlled trials (RCTs) in adults (≥18 years), phase II, III or IV; (2) English language; (3) comparing the effect of lipid-lowering drugs vs placebo (addition of the same drug to both intervention and control group was acceptable); (4) reporting the effects on Lp(a) levels; (5) intervention duration of more than 3 weeks. The between-group (treatment-placebo) Lp(a) absolute mean differences and 95% confidence intervals were calculated for each drug class separately. A total of 145,314 subjects from 147 RCTs were included. Statins, bempedoic acid, ezetimibe, omega-3 fatty acids, and fibrates did not affect Lp(a) concentration. Lp(a) levels were significantly reduced by PCSK9 monoclonal antibodies (PCSK9mAbs, -6.37 mg/dL [-7.26 to -5.47], a 29% reduction from baseline), inclisiran (-4.76 mg/dL [-5.83 to -3.69], a 22% reduction from baseline), CETP inhibitors (CETPi, -6.77 mg/dL [-8.67 to -4.88], a 46% reduction from baseline), and niacin (-7.06 mg/dL [-9.27 to -4.85], a 37% reduction from baseline). In the subgroup analysis by baseline Lp(a) levels, a larger absolute reduction of Lp(a) levels was observed with increasing baseline levels of Lp(a) for PCSK9mAbs, inclisiran, and CETPi. Among available LLTs, PCSK9mAbs, inclisiran, CETPi, and niacin significantly decreased Lp(a) levels. Further research is necessary to understand whether this effect would translate into a clinically relevant cardiovascular benefit. Show less

The availability of pharmacological approaches able to effectively reduce circulating LDL cholesterol (LDL-C) has led to a substantial reduction in the risk of atherosclerosis-related cardiovascular disease (CVD). However, a residual cardiovascular (CV) risk persists in treated individuals with optimal levels of LDL-C. Additional risk factors beyond LDL-C are involved, and among these, elevated levels of triglycerides (TGs) and TG-rich lipoproteins are causally associated with an increased CV risk. Apolipoprotein C-III (apoC-III) is a key regulator of TG metabolism and hence circulating levels through several mechanisms including the inhibition of lipoprotein lipase activity and alterations in the affinity of apoC-III-containing lipoproteins for both the hepatic receptors involved in their removal and extracellular matrix in the arterial wall. Genetic studies have clarified the role of apoC-III in humans, establishing a causal link with CVD and showing that loss-of-function mutations in the APOC3 gene are associated with reduced TG levels and reduced risk of coronary heart disease. Currently available hypolipidaemic drugs can reduce TG levels, although to a limited extent. Substantial reductions in TG levels can be obtained with new drugs that target specifically apoC-III; these include two antisense oligonucleotides, one small interfering RNA and an antibody. Show less

Obicetrapib, a novel, selective cholesteryl ester transfer protein (CETP) inhibitor, reduces low-density lipoprotein cholesterol (LDL-C), LDL particles, apolipoprotein (Apo) B, and lipoprotein(a) [Lp(a)] and increases high-density lipoprotein cholesterol (HDL-C) when added to statins with or without ezetimibe. By substantially reducing LDL-C, obicetrapib has the potential to lower atherogenic lipoproteins in patients with atherosclerotic cardiovascular disease (ASCVD) or heterozygous familial hypercholesterolemia (HeFH) whose LDL-C levels remain high despite treatment with available maximally tolerated lipid-modifying therapies, addressing an unmet medical need in a patient population at high risk for cardiovascular events. BROADWAY (NCT05142722) and BROOKLYN (NCT05425745) are ongoing placebo-controlled, double-blind, randomized Phase III trials designed to examine the efficacy, safety, and tolerability of obicetrapib as an adjunct to dietary intervention and maximally tolerated lipid-modifying therapies in participants with a history of ASCVD and/or underlying HeFH whose LDL-C is not adequately controlled. The primary efficacy endpoint was the percent change in LDL-C from baseline to day 84. Other endpoints included changes in Apo B, non-HDL-C, HDL-C, Apo A1, Lp(a), and triglycerides in addition to parameters evaluating safety, tolerability, and pharmacokinetics. BROADWAY also included an adjudicated assessment of major adverse cardiovascular events, measurements of glucose homeostasis, and an ambulatory blood pressure monitoring substudy. A total of 2,532 participants were randomized in BROADWAY and 354 in BROOKLYN to receive obicetrapib 10 mg or placebo (2:1) for 365 days with follow-up through 35 days after the last dose. Results from both trials are anticipated in 2024. These trials will provide safety and efficacy data to support the potential use of obicetrapib among patients with ASCVD or HeFH with elevated LDL-C for whom existing therapies are not sufficiently effective or well-tolerated. Show less

Glioblastoma multiforme (GBM) recurrences after temozolomide (TMZ) treatment result from the expansion of drug-resistant and potentially invasive GBM cells. This process is facilitated by O6-Methylguanine-DNA Methyltransferase (MGMT), which counteracts alkylating TMZ activity. We traced the expansion of invasive cell lineages under persistent chemotherapeutic stress in MGMT Show less

Some cholesteryl ester transfer protein (CETP) inhibitors lower low-density lipoprotein cholesterol (LDL-C) levels without reducing cardiovascular events, suggesting that the clinical benefit of lowering LDL-C may depend on how LDL-C is lowered. To estimate the association between changes in levels of LDL-C (and other lipoproteins) and the risk of cardiovascular events related to variants in the CETP gene, both alone and in combination with variants in the 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) gene. Mendelian randomization analyses evaluating the association between CETP and HMGCR scores, changes in lipid and lipoprotein levels, and the risk of cardiovascular events involving 102 837 participants from 14 cohort or case-control studies conducted in North America or the United Kingdom between 1948 and 2012. The associations with cardiovascular events were externally validated in 189 539 participants from 48 studies conducted between 2011 and 2015. Differences in mean high-density lipoprotein cholesterol (HDL-C), LDL-C, and apolipoprotein B (apoB) levels in participants with CETP scores at or above vs below the median. Odds ratio (OR) for major cardiovascular events. The primary analysis included 102 837 participants (mean age, 59.9 years; 58% women) who experienced 13 821 major cardiovascular events. The validation analyses included 189 539 participants (mean age, 58.5 years; 39% women) with 62 240 cases of coronary heart disease (CHD). Considered alone, the CETP score was associated with higher levels of HDL-C, lower LDL-C, concordantly lower apoB, and a corresponding lower risk of major vascular events (OR, 0.946 [95% CI, 0.921-0.972]) that was similar in magnitude to the association between the HMGCR score and risk of major cardiovascular events per unit change in levels of LDL-C (and apoB). When combined with the HMGCR score, the CETP score was associated with the same reduction in LDL-C levels but an attenuated reduction in apoB levels and a corresponding attenuated nonsignificant risk of major cardiovascular events (OR, 0.985 [95% CI, 0.955-1.015]). In external validation analyses, a genetic score consisting of variants with naturally occurring discordance between levels of LDL-C and apoB was associated with a similar risk of CHD per unit change in apoB level (OR, 0.782 [95% CI, 0.720-0.845] vs 0.793 [95% CI, 0.774-0.812]; P = .79 for difference), but a significantly attenuated risk of CHD per unit change in LDL-C level (OR, 0.916 [95% CI, 0.890-0.943] vs 0.831 [95% CI, 0.816-0.847]; P < .001) compared with a genetic score associated with concordant changes in levels of LDL-C and apoB. Combined exposure to variants in the genes that encode the targets of CETP inhibitors and statins was associated with discordant reductions in LDL-C and apoB levels and a corresponding risk of cardiovascular events that was proportional to the attenuated reduction in apoB but significantly less than expected per unit change in LDL-C. The clinical benefit of lowering LDL-C levels may therefore depend on the corresponding reduction in apoB-containing lipoprotein particles. Show less

Low high density lipoprotein cholesterol (HDL-C) levels represent an independent risk factor for cardiovascular disease; in addition to the reduced HDL-C levels commonly observed in patients at cardiovascular risk, the presence of dysfunctional HDL, i.e. HDL with reduced atheroprotective properties, has been reported. Despite the established inverse correlation between HDL-C levels and cardiovascular risk, several clinical trials with HDL-C-increasing drugs (such as niacin, CETP inhibitors or fibrate) failed to demonstrate that a significant rise in HDL-C levels translate into a cardiovascular benefit. Statins, that are the most used lipid-lowering drugs, can also increase HDL-C levels, although this effect is highly variable among studies and statins; the most recent developed statin, pitavastatin, beside its role as LDL-C-lowering agent, increases HDL-C levels at a significantly higher extent and progressively upon treatment; such increase was observed also when patients where shifted from another statin to pitavastatin. The stratification by baseline HDL-C levels revealed that only pitavastatin significantly increased HDL-C levels in patients with baseline HDL-C ≤45 mg/dl, while no changes were observed in patients with higher baseline HDL-C levels. In the last years the hypothesis that functional properties of HDL may be more relevant than HDL-C levels has risen from several observations. The treatment with pitavastatin not only increased HDL-C levels, but also increased the phospholipid content of HDL, increased the HDL efflux capacity and their anti-oxidant properties. These observations suggest that, besides its high LDL-C-lowering effect, pitavastatin also exhibits a significantly higher ability to increase HDL-C levels and may also positively affect the quality and functionality of HDL particles. Show less

Apolipoprotein C-III (apoC-III) has a critical role in the metabolism of triglyceride (TG)-rich lipoproteins (TRLs). Animal models lacking the APOC3 gene exhibit reduced plasma TG levels, whereas the overexpression of APOC3 leads to increased TG levels. In humans, loss-of-function mutations in APOC3 are associated with reduced plasma TG levels and reduced risk for ischemic vascular disease and coronary heart disease. Several hypolipidemic agents have been shown to reduce apoC-III, including fibrates and statins, and antisense technology aimed at inhibiting APOC3 mRNA to decrease the production of apoC-III is currently in Phase III of clinical development. Here, we review the pathophysiological role of apoC-III in TG metabolism and the evidence supporting this apolipoprotein as an emerging target for hypertriglyceridemia (HTG) and associated cardiovascular disorders. Show less

A direct relationship between high plasma triglyceride (TG) levels and increased risk of cardiovascular disease has been shown in several studies. TG are present in the blood associated with different lipoprotein classes, including hepatically-derived very low density lipoproteins (VLDL) and intestinally-derived chylomicrons. Lipoprotein lipase (LPL) is a key enzyme that hydrolyzes TG, releasing free fatty acids that accumulate in peripheral tissues and remnant lipoproteins, that are then cleared by the liver. LPL activity is finely modulated by several cofactors, including apolipoprotein C-III (apoC-III) which acts as a LPL inhibitor. The key role of apoCIII has been established in several studies: animal models lacking APOC3 gene exhibit reduced plasma TG levels, whereas the overexpression of APOC3 gene led to increased TG levels. In humans, several mutations in APOC3 gene have been identified, leading to lower apoC-III levels and associated with reduced plasma TG levels. Recently, these mutations were found to be associated with a reduced risk for cardiovascular ischemia and coronary heart disease, thus confirming the negative role of apoC-III in TG metabolism and suggesting apoC-III as possible therapeutic target for the management of hypertriglyceridemia. Show less

Mutations in LPL or APOC2 genes are recognized causes of inherited forms of severe hypertriglyceridemia. However, some hypertrigliceridemic patients do not have mutations in either of these genes. Because inactivation or hyperexpression of APOA5 gene, encoding apolipoprotein A-V (apoA-V), causes a marked increase or decrease of plasma triglycerides in mice, and because some common polymorphisms of this gene affect plasma triglycerides in humans, we have hypothesized that loss of function mutations in APOA5 gene might cause hypertriglyceridemia. We sequenced APOA5 gene in 10 hypertriglyceridemic patients in whom mutations in LPL and APOC2 genes had been excluded. One of them was found to be homozygous for a mutation in APOA5 gene (c.433 C>T, Q145X), predicted to generate a truncated apoA-V devoid of key functional domains. The plasma of this patient was found to activate LPL in vitro less efficiently than control plasma, thus suggesting that apoA-V might be an activator of LPL. Ten carriers of Q145X mutation were found in the patient's family; 5 of them had mild hypertriglyceridemia. As predicted from animal studies, apoA-V deficiency is associated with severe hypertriglyceridemia in humans. This observation suggests that apoA-V regulates the secretion and/or catabolism of triglyceride-rich lipoproteins. Mutations in APOA5 gene might be the cause of severe hypertriglyceridemia in subjects in whom mutations in LPL or APOC2 genes have been excluded. We detected a nonsense mutation in APOA5 gene (Q145X) in a boy with hyperchylomicronemia syndrome. This is the first observation of a complete apoA-V deficiency in humans. Show less