Flipped C-Terminal Ends of APOA1 Promote ABCA1-Dependent Cholesterol Efflux by Small HDLs.

BACKGROUND: Cholesterol efflux capacity (CEC) predicts cardiovascular disease independently of high-density lipoprotein (HDL) cholesterol levels. Isolated small HDL particles are potent promoters of macrophage CEC by the ABCA1 (ATP-binding cassette transporter A1) pathway, but the underlying mechanisms are unclear. METHODS: We used model system studies of reconstituted HDL and plasma from control and lecithin-cholesterol acyltransferase (LCAT)-deficient subjects to investigate the relationships among the sizes of HDL particles, the structure of APOA1 (apolipoprotein A1) in the different particles, and the CECs of plasma and isolated HDLs. RESULTS: We quantified macrophage and ABCA1 CEC of 4 distinct sizes of reconstituted HDL. CEC increased as particle size decreased. Tandem mass spectrometric analysis of chemically cross-linked peptides and molecular dynamics simulations of APOA1, the major protein of HDL, indicated that the mobility of C-terminus of that protein was markedly higher and flipped off the surface in the smallest particles. To explore the physiological relevance of the model system studies, we isolated HDL from LCAT-deficient subjects, whose small HDLs (like reconstituted HDLs) are discoidal and composed of APOA1, cholesterol, and phospholipid. Despite their very low plasma levels of HDL particles, these subjects had normal CEC. In both the LCAT-deficient subjects and control subjects, the CEC of isolated extra-small HDL (a mixture of extra-small and small HDL by calibrated ion mobility analysis) was 3- to 5-fold greater than that of the larger sizes of isolated HDL. Incubating LCAT-deficient plasma and control plasma with human LCAT converted extra-small and small HDL particles into larger particles, and it markedly inhibited CEC. CONCLUSIONS: We present a mechanism for the enhanced CEC of small HDLs. In smaller particles, the C-termini of the 2 antiparallel molecules of APOA1 are "flipped" off the lipid surface of HDL. This extended conformation allows them to engage with ABCA1. In contrast, the C-termini of larger HDLs are unable to interact productively with ABCA1 because they form a helical bundle that strongly adheres to the lipid on the particle. Enhanced CEC, as seen with the smaller particles, predicts decreased cardiovascular disease risk. Thus, extra-small and small HDLs may be key mediators and indicators of the cardioprotective effects of HDL.

Evaluation of high-density lipoprotein-bound long non-coding RNAs in subjects with familial hypercholesterolaemia.

BACKGROUND: Long non-coding RNAs (lncRNAs) could be attractive circulating biomarkers for cardiovascular risk stratification in subjects at high atherosclerotic cardiovascular disease risk such as familial hypercholesterolaemia (FH). Our aim was to investigate the presence of lncRNAs carried by high-density lipoprotein (HDL) in FH subjects and to evaluate the associations of HDL-lncRNAs with lipoproteins and mechanical vascular impairment assessed by pulse wave velocity (PWV). METHODS: This was a retrospective observational study involving 94 FH subjects on statin treatment. Biochemical assays, HDL purification, lncRNA and PWV analyses were performed in all subjects. RESULTS: LncRNA HIF1A-AS2, LASER and LEXIS were transported by HDL; moreover, HDL-lncRNA LEXIS was associated with Lp(a) plasma levels (p < .01). In a secondary analysis, the study population was stratified into two groups based on the Lp(a) median value. The high-Lp(a) group exhibited a significant increase of PWV compared to the low-Lp(a) group (9.23 ± .61 vs. 7.67 ± .56, p < .01). While HDL-lncRNA HIF1A-AS2 and LASER were similar in the two groups, the high-Lp(a) group exhibited a significant downregulation of HDL-lncRNA LEXIS compared to the low-Lp(a) group (fold change -4.4, p < .0001). Finally, Lp(a) and HDL-lncRNA LEXIS were associated with PWV (for Lp(a) p < .01; for HDL-lncRNA LEXIS p < .05). CONCLUSIONS: LncRNA HIF1A-AS2, LASER and LEXIS were transported by HDL; moreover, significant relationships of HDL-lncRNA LEXIS with Lp(a) levels and PWV were found. Our study suggests that HDL-lncRNA LEXIS may be useful to better identify FH subjects with more pronounced vascular damage.

Ropeginterferon phase 2 randomized study in low-risk polycythemia vera: 5-year drug survival and efficacy outcomes.

In patients with low-risk polycythemia vera, exposure to low-dose Ropeginterferon alfa-2b (Ropeg) 100 µg every 2 weeks for 2 years was more effective than the standard treatment of therapeutic phlebotomy in maintaining target hematocrit (HCT) (< 45%) with a reduction in the need for phlebotomy without disease progression. In the present paper, we analyzed drug survival, defined as a surrogate measure of the efficacy, safety, adherence, and tolerability of Ropeg in patients followed up to 5 years. During the first 2 years, Ropeg and phlebotomy-only (Phl-O) were discontinued in 33% and 70% of patients, respectively, for lack of response (12 in the Ropeg arm vs. 34 in the Phl-O arm) or adverse events (6 vs. 0) and withdrawal of consent in (3 vs. 10). Thirty-six Ropeg responders continued the drug for up to 3 years, and the probability of drug survival after a median of 3.15 years was 59%. Notably, the primary composite endpoint was maintained in 97%, 94%, and 94% of patients still on drug at 3, 4, and 5 years, respectively, and 60% of cases were phlebotomy-free. Twenty-three of 63 Phl-O patients (37%) failed the primary endpoint and were crossed over to Ropeg; among the risk factors for this failure, the need for more than three bloodletting procedures in the first 6 months emerged as the most important determinant. In conclusion, to improve the effectiveness of Ropeg, we suggest increasing the dose and using it earlier driven by high phlebotomy need in the first 6 months post-diagnosis.

In Silico Description of the Direct Inhibition Mechanism of Endothelial Lipase by ANGPTL3.

Angiopoietin-like protein 3 (ANGPTL3) is a plasmatic protein that plays a crucial role in lipoprotein metabolism by inhibiting the lipoprotein lipase (LPL) and the endothelial lipase (EL) responsible for the hydrolysis of phospholipids on high-density lipoprotein (HDL). Interest in developing new pharmacological therapies aimed at inhibiting ANGPTL3 has been growing due to the hypolipidemic and antiatherogenic profile observed in its absence. The goal of this study was the in silico characterization of the interaction between ANGPTL3 and EL. Because of the lack of any structural information on both the trimeric coiled-coil N-terminal domain of ANGPTL3 and the EL homodimer as well as data regarding their interactions, the first step was to obtain the three-dimensional model of these two proteins. The models were then refined via molecular dynamics (MD) simulations and used to investigate the interaction mechanism. The analysis of interactions in different docking poses and their refinement via MD allowed the identification of three specific glutamates of ANGPTL3 that recognize a positively charged patch on the surface of EL. These ANGPTL3 key residues, i.e., Glu154, Glu157, and Glu160, could form a putative molecular recognition site for EL. This study paves the way for future investigations aimed at confirming the recognition site and at designing novel inhibitors of ANGPTL3.

Clonal dynamics and copy number variants by single-cell analysis in leukemic evolution of myeloproliferative neoplasms.

Transformation from chronic (CP) to blast phase (BP) in myeloproliferative neoplasm (MPN) remains poorly characterized, and no specific mutation pattern has been highlighted. BP-MPN represents an unmet need, due to its refractoriness to treatment and dismal outcome. Taking advantage of the granularity provided by single-cell sequencing (SCS), we analyzed paired samples of CP and BP in 10 patients to map clonal trajectories and interrogate target copy number variants (CNVs). Already at diagnosis, MPN present as oligoclonal diseases with varying ratio of mutated and wild-type cells, including cases where normal hematopoiesis was entirely surmised by mutated clones. BP originated from increasing clonal complexity, either on top or independent of a driver mutation, through acquisition of novel mutations as well as accumulation of clones harboring multiple mutations, that were detected at CP by SCS but were missed by bulk sequencing. There were progressive copy-number imbalances from CP to BP, that configured distinct clonal profiles and identified recurrences in genes including NF1, TET2, and BCOR, suggesting an additional level of complexity and contribution to leukemic transformation. EZH2 emerged as the gene most frequently affected by single nucleotide and CNVs, that might result in EZH2/PRC2-mediated transcriptional deregulation, as supported by combined scATAC-seq and snRNA-seq analysis of the leukemic clone in a representative case. Overall, findings provided insights into the pathogenesis of MPN-BP, identified CNVs as a hitherto poorly characterized mechanism and point to EZH2 dysregulation as target. Serial assessment of clonal dynamics might potentially allow early detection of impending disease transformation, with therapeutic implications.

Plasma FA composition in familial LCAT deficiency indicates SOAT2-derived cholesteryl ester formation in humans.

Mutations in the LCAT gene cause familial LCAT deficiency (Online Mendelian Inheritance in Man ID: #245900), a very rare metabolic disorder. LCAT is the only enzyme able to esterify cholesterol in plasma, whereas sterol O-acyltransferases 1 and 2 are the enzymes esterifying cellular cholesterol in cells. Despite the complete lack of LCAT activity, patients with familial LCAT deficiency exhibit circulating cholesteryl esters (CEs) in apoB-containing lipoproteins. To analyze the origin of these CEs, we investigated 24 carriers of LCAT deficiency in this observational study. We found that CE plasma levels were significantly reduced and highly variable among carriers of two mutant LCAT alleles (22.5 [4.0-37.8] mg/dl) and slightly reduced in heterozygotes (218 [153-234] mg/dl). FA distribution in CE (CEFA) was evaluated in whole plasma and VLDL in a subgroup of the enrolled subjects. We found enrichment of C16:0, C18:0, and C18:1 species and a depletion in C18:2 and C20:4 species in the plasma of carriers of two mutant LCAT alleles. No changes were observed in heterozygotes. Furthermore, plasma triglyceride-FA distribution was remarkably similar between carriers of LCAT deficiency and controls. CEFA distribution in VLDL essentially recapitulated that of plasma, being mainly enriched in C16:0 and C18:1, while depleted in C18:2 and C20:4. Finally, after fat loading, chylomicrons of carriers of two mutant LCAT alleles showed CEs containing mainly saturated FAs. This study of CEFA composition in a large cohort of carriers of LCAT deficiency shows that in the absence of LCAT-derived CEs, CEs present in apoB-containing lipoproteins are derived from hepatic and intestinal sterol O-acyltransferase 2.

The HDL mimetic CER-001 remodels plasma lipoproteins and reduces kidney lipid deposits in inherited lecithin:cholesterol acyltransferase deficiency.

BACKGROUND: Kidney failure is the major cause of morbidity and mortality in familial lecithin:cholesterol acyltransferase deficiency (FLD), a rare inherited lipid disorder with no cure. Lipoprotein X (LpX), an abnormal lipoprotein, is primarily accountable for nephrotoxicity. METHODS: CER-001 was tested in an FLD patient with dramatic kidney disease for 12 weeks. RESULTS: Infusions of CER-001 normalized the lipoprotein profile, with a disappearance of the abnormal LpX in favour of normal-sized LDL. The worsening of kidney function was slowed by the treatment, and kidney biopsy showed a slight reduction of lipid deposits and a stabilization of the disease. In vitro experiments demonstrate that CER-001 progressively reverts lipid accumulation in podocytes by a dual effect: remodelling plasma lipoproteins and removing LpX-induced lipid deposit. CONCLUSION: This study demonstrates that CER-001 may represent a therapeutic option in FLD patients. It also has the potential to be beneficial in other renal diseases characterized by kidney lipid deposits.

rHDL modeling and the anchoring mechanism of LCAT activation.

Lecithin:cholesterol-acyl transferase (LCAT) plays a major role in cholesterol metabolism as it is the only extracellular enzyme able to esterify cholesterol. LCAT activity is required for lipoprotein remodeling and, most specifically, for the growth and maturation of HDLs. In fact, genetic alterations affecting LCAT functionality may cause a severe reduction in plasma levels of HDL-cholesterol with important clinical consequences. Although several hypotheses were formulated, the exact molecular recognition mechanism between LCAT and HDLs is still unknown. We employed a combination of structural bioinformatics procedures to deepen the insights into the HDL-LCAT interplay that promotes LCAT activation and cholesterol esterification. We have generated a data-driven model of reconstituted HDL (rHDL) and studied the dynamics of an assembled rHDL::LCAT supramolecular complex, pinpointing the conformational changes originating from the interaction between LCAT and apolipoprotein A-I (apoA-I) that are necessary for LCAT activation. Specifically, we propose a mechanism in which the anchoring of LCAT lid to apoA-I helices allows the formation of a hydrophobic hood that expands the LCAT active site and shields it from the solvent, allowing the enzyme to process large hydrophobic substrates.

Vasculoprotective properties of plasma lipoproteins from brown bears (Ursus arctos).

Plasma cholesterol and triglyceride (TG) levels are twice as high in hibernating brown bears (Ursus arctos) than healthy humans. Yet, bears display no signs of early stage atherosclerosis development when adult. To explore this apparent paradox, we analyzed plasma lipoproteins from the same 10 bears in winter (hibernation) and summer using size exclusion chromatography, ultracentrifugation, and electrophoresis. LDL binding to arterial proteoglycans (PGs) and plasma cholesterol efflux capacity (CEC) were also evaluated. The data collected and analyzed from bears were also compared with those from healthy humans. In bears, the cholesterol ester, unesterified cholesterol, TG, and phospholipid contents of VLDL and LDL were higher in winter than in summer. The percentage lipid composition of LDL differed between bears and humans but did not change seasonally in bears. Bear LDL was larger, richer in TGs, showed prebeta electrophoretic mobility, and had 5-10 times lower binding to arterial PGs than human LDL. Finally, plasma CEC was higher in bears than in humans, especially the HDL fraction when mediated by ABCA1. These results suggest that in brown bears the absence of early atherogenesis is likely associated with a lower affinity of LDL for arterial PGs and an elevated CEC of bear plasma.

Reduced Levels of ABCA1 Transporter Are Responsible for the Cholesterol Efflux Impairment in ß-Amyloid-Induced Reactive Astrocytes: Potential Rescue from Biomimetic HDLs.

The cerebral synthesis of cholesterol is mainly handled by astrocytes, which are also responsible for apoproteins' synthesis and lipoproteins' assembly required for the cholesterol transport in the brain parenchyma. In Alzheimer disease (AD), these processes are impaired, likely because of the astrogliosis, a process characterized by morphological and functional changes in astrocytes. Several ATP-binding cassette transporters expressed by brain cells are involved in the formation of nascent discoidal lipoproteins, but the effect of beta-amyloid (Aß) assemblies on this process is not fully understood. In this study, we investigated how of Aß1-42-induced astrogliosis affects the metabolism of cholesterol in vitro. We detected an impairment in the cholesterol efflux of reactive astrocytes attributable to reduced levels of ABCA1 transporters that could explain the decreased lipoproteins' levels detected in AD patients. To approach this issue, we designed biomimetic HDLs and evaluated their performance as cholesterol acceptors. The results demonstrated the ability of apoA-I nanodiscs to cross the blood-brain barrier in vitro and to promote the cholesterol efflux from astrocytes, making them suitable as a potential supportive treatment for AD to compensate the depletion of cerebral HDLs.

Genetic, biochemical, and clinical features of LCAT deficiency: update for 2020.

PURPOSE OF REVIEW: Genetic LCAT deficiency is a rare metabolic disorder characterized by low-plasma HDL cholesterol levels. Clinical manifestations of the disease include corneal opacification, anemia, and renal disease, which represents the major cause of morbidity and mortality in carriers. RECENT FINDINGS: Biochemical and clinical manifestations of the disease are very heterogeneous among carriers. The collection of large series of affected individuals is needed to answer various open questions on this rare disorder of lipid metabolism, such as the cause of renal damage in patients with complete LCAT deficiency and the cardiovascular risk in carriers of different LCAT gene mutations. SUMMARY: Familial LCAT deficiency is a rare disease, with serious clinical manifestations, which can occur in the first decades of life, and presently with no cure. The timely diagnosis in carriers, together with the identification of disease biomarkers able to predict the evolution of clinical manifestations, would be of great help in the identification of carriers to address to future available therapies.

Progression of chronic kidney disease in familial LCAT deficiency: a follow-up of the Italian cohort.

Familial LCAT deficiency (FLD) is a rare genetic disorder of HDL metabolism, caused by loss-of-function mutations in the LCAT gene and characterized by a variety of symptoms including corneal opacities and kidney failure. Renal disease represents the leading cause of morbidity and mortality in FLD cases. However, the prognosis is not known and the rate of deterioration of kidney function is variable and unpredictable from patient to patient. In this article, we present data from a follow-up of the large Italian cohort of FLD patients, who have been followed for an average of 12 years. We show that renal failure occurs at the median age of 46 years, with a median time to a second recurrence of 10 years. Additionally, we identify high plasma unesterified cholesterol level as a predicting factor for rapid deterioration of kidney function. In conclusion, this study highlights the severe consequences of FLD, underlines the need of correct early diagnosis and referral of patients to specialized centers, and highlights the urgency for effective treatments to prevent or slow renal disease in patients with LCAT deficiency.

Lecithin:cholesterol acyltransferase: symposium on 50 years of biomedical research from its discovery to latest findings.

LCAT converts free cholesterol to cholesteryl esters in the process of reverse cholesterol transport. Familial LCAT deficiency (FLD) is a genetic disease that was first described by Kaare R. Norum and Egil Gjone in 1967. This report is a summary from a 2017 symposium where Dr. Norum recounted the history of FLD and leading experts on LCAT shared their results. The Tesmer laboratory shared structural findings on LCAT and the close homolog, lysosomal phospholipase A2. Results from studies of FLD patients in Finland, Brazil, Norway, and Italy were presented, as well as the status of a patient registry. Drs. Kuivenhoven and Calabresi presented data from carriers of genetic mutations suggesting that FLD does not necessarily accelerate atherosclerosis. Dr. Ng shared that LCAT-null mice were protected from diet-induced obesity, insulin resistance, and nonalcoholic fatty liver disease. Dr. Zhou presented multiple innovations for increasing LCAT activity for therapeutic purposes, whereas Dr. Remaley showed results from treatment of an FLD patient with recombinant human LCAT (rhLCAT). Dr. Karathanasis showed that rhLCAT infusion in mice stimulates cholesterol efflux and suggested that it could also enhance cholesterol efflux from macrophages. While the role of LCAT in atherosclerosis remains elusive, the consensus is that a continued study of both the enzyme and disease will lead toward better treatments for patients with heart disease and FLD.

Activation of Naturally Occurring Lecithin:Cholesterol Acyltransferase Mutants by a Novel Activator Compound.

Lecithin:cholesterol acyltransferase (LCAT) is a unique plasma enzyme able to esterify cholesterol, and it plays an important role in HDL maturation and promotion of reverse cholesterol transport. Familial LCAT deficiency (FLD; OMIM number 245900) is a rare recessive disease that results from loss-of-function mutations in the LCAT gene and has no cure. In this study, we assessed the in vitro efficacy of a novel small-molecule LCAT activator. Cholesterol esterification rate (CER) and LCAT activity were tested in plasma from six controls and five FLD homozygous carriers of various LCAT mutations at different doses of the compound (0.1, 1, and 10 µg/ml). In control plasma, the compound significantly increased both CER (P < 0.001) and LCAT activity (P = 0.007) in a dose-dependent manner. Both CER and LCAT activity increased by 4- to 5-fold, reaching maximum activation at the dose of 1 µg/ml. Interestingly, Daiichi Sankyo compound produced an increase in CER in two of the five tested LCAT mutants (Leu372--Arg and Val309--Met), while LCAT activity increased in three LCAT mutants (Arg147--Trp, Thr274--Ile and Leu372--Arg); mutant Pro254--Ser was not activated at any of the tested doses. The present findings form the basis for personalized therapeutic interventions in FLD carriers and support the potential LCAT activation in secondary LCAT defects. SIGNIFICANCE STATEMENT: We characterized the pharmacology of a novel small-molecule LCAT activator in vitro on a subset of naturally occurring LCAT mutants. Our findings form the basis for personalized therapeutic interventions for familial LCAT deficiency carriers, who can face severe complications and for whom no cure exists.

Recombinant LCAT (Lecithin:Cholesterol Acyltransferase) Rescues Defective HDL (High-Density Lipoprotein)-Mediated Endothelial Protection in Acute Coronary Syndrome.

Objective- Aim of this study was to evaluate changes in LCAT (lecithin:cholesterol acyltransferase) concentration and activity in patients with an acute coronary syndrome, to investigate if these changes are related to the compromised capacity of HDL (high-density lipoprotein) to promote endothelial nitric oxide (NO) production, and to assess if rhLCAT (recombinant human LCAT) can rescue the defective vasoprotective HDL function. Approach and Results- Thirty ST-segment-elevation myocardial infarction (STEMI) patients were enrolled, and plasma was collected at hospital admission, 48 and 72 hours thereafter, at hospital discharge, and at 30-day follow-up. Plasma LCAT concentration and activity were measured and related to the capacity of HDL to promote NO production in cultured endothelial cells. In vitro studies were performed in which STEMI patients' plasma was added with rhLCAT and HDL vasoprotective activity assessed by measuring NO production in endothelial cells. The plasma concentration of the LCAT enzyme significantly decreases during STEMI with a parallel significant reduction in LCAT activity. HDL isolated from STEMI patients progressively lose the capacity to promote NO production by endothelial cells, and the reduction is related to decreased LCAT concentration. In vitro incubation of STEMI patients' plasma with rhLCAT restores HDL ability to promote endothelial NO production, possibly related to significant modification in HDL phospholipid classes. Conclusions- Impairment of cholesterol esterification may be a major factor in the HDL dysfunction observed during acute coronary syndrome. rhLCAT is able to restore HDL-mediated NO production in vitro, suggesting LCAT as potential therapeutic target for restoring HDL functionality in acute coronary syndrome.

The Prospective Studies of Atherosclerosis (Proof-ATHERO) Consortium: Design and Rationale.

Atherosclerosis - the pathophysiological mechanism shared by most cardiovascular diseases - can be directly or indirectly assessed by a variety of clinical tests including measurement of carotid intima-media thickness, carotid plaque, -ankle-brachial index, pulse wave velocity, and coronary -artery calcium. The Prospective Studies of Atherosclerosis -(Proof-ATHERO) consortium (https://clinicalepi.i-med.ac.at/research/proof-athero/) collates de-identified individual-participant data of studies with information on atherosclerosis measures, risk factors for cardiovascular disease, and incidence of cardiovascular diseases. It currently comprises 74 studies that involve 106,846 participants from 25 countries and over 40 cities. In summary, 21 studies recruited participants from the general population (n = 67,784), 16 from high-risk populations (n = 22,677), and 37 as part of clinical trials (n = 16,385). Baseline years of contributing studies range from April 1980 to July 2014; the latest follow-up was until June 2019. Mean age at baseline was 59 years (standard deviation: 10) and 50% were female. Over a total of 830,619 person-years of follow-up, 17,270 incident cardiovascular events (including coronary heart disease and stroke) and 13,270 deaths were recorded, corresponding to cumulative incidences of 2.1% and 1.6% per annum, respectively. The consortium is coordinated by the Clinical Epidemiology Team at the Medical University of Innsbruck, Austria. Contributing studies undergo a detailed data cleaning and harmonisation procedure before being incorporated in the Proof-ATHERO central database. Statistical analyses are being conducted according to pre-defined analysis plans and use established methods for individual-participant data meta-analysis. Capitalising on its large sample size, the multi-institutional collaborative Proof-ATHERO consortium aims to better characterise, understand, and predict the development of atherosclerosis and its clinical consequences.

Complete and Partial Lecithin:Cholesterol Acyltransferase Deficiency Is Differentially Associated With Atherosclerosis.

BACKGROUND: Lecithin:cholesterol acyltransferase (LCAT) is the sole enzyme that esterifies cholesterol in plasma. Its role in the supposed protection from atherogenesis remains unclear because mutations in LCAT causing fish-eye disease (FED) or familial LCAT deficiency (FLD) have been reported to be associated with more or instead less carotid atherosclerosis, respectively. This discrepancy may be associated with the loss of cholesterol esterification on only apolipoprotein AI (FED) or on both apolipoprotein AI- and apolipoprotein B-containing lipoproteins (FLD), an aspect that has thus far not been investigated. METHODS: Seventy-four heterozygotes for LCAT mutations recruited from Italy and the Netherlands were assigned to FLD (n=33) or FED (n=41) groups and compared with 280 control subjects. Subclinical atherosclerosis was assessed with carotid intima-media thickness. RESULTS: Compared with control subjects, total cholesterol was lower by 16% (-32.9 mg/dL) and 7% (-14.9 mg/dL) and high-density lipoprotein cholesterol was lower by 29% (-16.7 mg/dL) and 36% (-20.7 mg/dL) in the FLD and FED groups, respectively. Subjects with FLD displayed a significant 18% lower low-density lipoprotein cholesterol compared with subjects with FED (101.9±35.0 versus 123.6±47.4 mg/dL; P=0.047) and control subjects (122.6±35.0 mg/dL; P=0.003). Remarkably, all 3 intima-media thickness parameters were lower in subjects with FLD compared with FED and control subjects (accounting for age, sex, body mass index, smoking, hypertension, family history of cardiovascular disease, and plasma lipids). After additional correction for nationality and ultrasonographic methods, average and maximum intima-media thickness remained significantly lower when subjects with FLD were compared with those with FED (0.59 versus 0.73 mm, P=0.003; and 0.87 versus 1.24 mm, P<0.001, respectively). In contrast, the common carotid intima-media thickness (corrected for age, sex, body mass index, smoking, hypertension, family history of cardiovascular disease, and plasma lipids) was higher in subjects with FED compared with control subjects (0.69 versus 0.65 mm; P=0.05), but this significance was lost after adjustment for nationality and ultrasonographic machine. CONCLUSIONS: In this head-to-head comparison, FLD and FED mutations were shown to be associated with decreased and increased atherosclerosis, respectively. We propose that this discrepancy is related to the capacity of LCAT to generate cholesterol esters on apolipoprotein B-containing lipoproteins. Although this capacity is lost in FLD, it is unaffected in FED. These results are important when considering LCAT as a target to decrease atherosclerosis.

Treatment with fibrates is associated with higher LAL activity in dyslipidemic patients.

Lysosomal acid lipase (LAL) is responsible for the hydrolysis of cholesteryl esters (CE) and triglycerides (TG) within the lysosomes; generated cholesterol and free fatty acids (FFA) are released in the cytosol where they can regulate their own synthesis and metabolism. When LAL is not active, as in case of genetic mutations, CE and TG accumulate in the lysosomal compartment, while the lack of release of cholesterol and FFA in the cytosol leads to an upregulation of their synthesis. Thus, LAL plays a central role in the intracellular homeostasis of lipids. Since there are no indications about the effect of different lipid-lowering agents on LAL activity, aim of the study was to address the relationship between LAL activity and the type of lipid-lowering therapy in a cohort of dyslipidemic patients. LAL activity was measured on dried blood spot from 120 patients with hypercholesterolemia or mixed dyslipidemia and was negatively correlated to LDL-cholesterol levels. Among enrolled patients, ninety-one were taking one or more lipid-lowering drugs, as statins, fibrates, ezetimibe and omega-3 polyunsaturated fatty acids. When patients were stratified according to the type of lipid-lowering treatment, i.e. untreated, taking statins or taking fibrates, LAL activity was significantly higher in those with fibrates, even after adjustment for sex, age, BMI, lipid parameters, liver function, metabolic syndrome, diabetes and statin use. In a subset of patients tested after 3 months of treatment with micronized fenofibrate, LAL activity raised by 21%; the increase was negatively correlated with baseline LAL activity. Thus, the use of fibrates is independently associated with higher LAL activity in dyslipidemic patients, suggesting that the positive effects of PPAR-α activation on cellular and systemic lipid homeostasis can also include an improved LAL activity.

Nutraceutical approach for the management of cardiovascular risk - a combination containing the probiotic Bifidobacterium longum BB536 and red yeast rice extract: results from a randomized, double-blind, placebo-controlled study.

BACKGROUND: Probiotics incorporated into dairy products have been shown to reduce total (TC) and LDL cholesterolemia (LDL-C) in subjects with moderate hypercholesterolemia. More specifically, probiotics with high biliary salt hydrolase activity, e.g. Bifidobacterium longum BB536, may decrease TC and LDL-C by lowering intestinal cholesterol reabsorption and, combined with other nutraceuticals, may be useful to manage hypercholesterolemia in subjects with low cardiovascular (CV) risk. This study was conducted to evaluate the efficacy and safety of a nutraceutical combination containing Bifidobacterium longum BB536, red yeast rice (RYR) extract (10 mg/day monacolin K), niacin, coenzyme Q10 (Lactoflorene Colesterolo®). The end-points were changes of lipid CV risk markers (LDL-C, TC, non-HDL-cholesterol (HDL-C), triglycerides (TG), apolipoprotein B (ApoB), HDL-C, apolipoprotein AI (ApoAI), lipoprotein(a) (Lp(a), proprotein convertase subtilisin/kexin type 9 (PCSK9)), and of markers of cholesterol synthesis/absorption. METHODS: A 12-week randomized, parallel, double-blind, placebo-controlled study. Thirty-three subjects (18-70 years) in primary CV prevention and low CV risk (SCORE: 0-1% in 24 and 2-4% in 9 subjects; LDL-C: 130-200 mg/dL) were randomly allocated to either nutraceutical (N = 16) or placebo (N = 17). RESULTS: Twelve-week treatment with the nutraceutical combination, compared to placebo, significantly reduced TC (- 16.7%), LDL-C (- 25.7%), non-HDL-C (- 24%) (all p < 0.0001), apoB (- 17%, p = 0.003). TG, HDL-C, apoAI, Lp(a), PCSK9 were unchanged. Lathosterol:TC ratio was significantly reduced by the nutraceutical combination, while campesterol:TC ratio and sitosterol:TC ratio did not change, suggesting reduction of synthesis without increased absorption of cholesterol. No adverse effects and a 97% compliance were observed. CONCLUSIONS: A 12-week treatment with a nutraceutical combination containing the probiotic Bifidobacterium longum BB536 and RYR extract significantly improved the atherogenic lipid profile and was well tolerated by low CV risk subjects. TRIAL REGISTRATION: NCT02689934 .

Correction to: Nutraceutical approach for the management of cardiovascular risk - a combination containing the probiotic Bifidobacterium longum BB536 and red yeast rice extract: results from a randomized, double-blind, placebo-controlled study.

Following publication of the original article [1], the authors reported an error in the affiliation of the third author, Sara Gandini. The correct affiliation should read: Division of Epidemiology and Biostatistics, IEO, European Institute of Oncology IRCCS, Milan, Italy.