The Contribution of GWAS Loci in Familial Dyslipidemias.

Familial combined hyperlipidemia (FCH) is a complex and common familial dyslipidemia characterized by elevated total cholesterol and/or triglyceride levels with over five-fold risk of coronary heart disease. The genetic architecture and contribution of rare Mendelian and common variants to FCH susceptibility is unknown. In 53 Finnish FCH families, we genotyped and imputed nine million variants in 715 family members with DNA available.

Opposite associations between alanine aminotransferase and γ-glutamyl transferase levels and all-cause mortality in type 2 diabetes: Analysis of the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study.

Aims: Reported associations between liver enzymes and mortality may not hold true in type 2 diabetes, owing to a high prevalence of non-alcoholic fatty liver disease, which has been linked to cardiovascular disease and mortality in its own right. Our study aimed to determine whether alanine aminotransferase (ALT) or γ-glutamyl transferase (GGT) levels predict mortality in type 2 diabetes, and to examine possible mechanisms.

Methods: Data from the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study were analyzed to examine the relationship between liver enzymes and all-cause and cause-specific mortality over 5years.

Effects of angiopoietin-like protein 3 deficiency on postprandial lipid and lipoprotein metabolism.

The consequences of angiopoietin-like protein 3 (ANGPTL3) deficiency on postprandial lipid and lipoprotein metabolism has not been investigated in humans. We studied 7 homozygous (undetectable circulating ANGPTL3 levels) and 31 heterozygous (50% of circulating ANGPTL3 levels) subjects with familial combined hypolipidemia (FHBL2) due to inactivating ANGPTL3 mutations in comparison with 35 controls. All subjects were evaluated at fasting and during 6 h after a high fat meal.

USF1 deficiency activates brown adipose tissue and improves cardiometabolic health.

USF1 (upstream stimulatory factor 1) is a transcription factor associated with familial combined hyperlipidemia and coronary artery disease in humans. However, whether USF1 is beneficial or detrimental to cardiometabolic health has not been addressed. By inactivating USF1 in mice, we demonstrate protection against diet-induced dyslipidemia, obesity, insulin resistance, hepatic steatosis, and atherosclerosis.

Low alanine aminotransferase levels and higher number of cardiovascular events in people with Type 2 diabetes: analysis of the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study.

Aims: To determine whether alanine aminotransferase or gamma-glutamyltransferase levels, as markers of liver health and non-alcoholic fatty liver disease, might predict cardiovascular events in people with Type 2 diabetes.

Methods: Data from the Fenofibrate Intervention and Event Lowering in Diabetes study were analysed to examine the relationship between liver enzymes and incident cardiovascular events (non-fatal myocardial infarction, stroke, coronary and other cardiovascular death, coronary or carotid revascularization) over 5 years.

Results: Alanine aminotransferase measure had a linear inverse relationship with the first cardiovascular event occurring in participants during the study period.

Regulation of Angiopoietin-Like Proteins (ANGPTLs) 3 and 8 by Insulin.

Objective: Circulating ANGPTL8 has recently been used as a marker of insulin action. We studied expression and insulin regulation of ANGPTL8 and ANGPTL3 in vivo and in vitro.

Design And Methods: Expression of ANGPTL8 and ANGPTL3 was studied in 34 paired samples of human liver and adipose tissue.

HDL biogenesis, remodeling, and catabolism.

In this chapter, we review how HDL is generated, remodeled, and catabolized in plasma. We describe key features of the proteins that participate in these processes, emphasizing how mutations in apolipoprotein A-I (apoA-I) and the other proteins affect HDL metabolism. The biogenesis of HDL initially requires functional interaction of apoA-I with the ATP-binding cassette transporter A1 (ABCA1) and subsequently interactions of the lipidated apoA-I forms with lecithin/cholesterol acyltransferase (LCAT).

Silencing of ANGPTL 3 (angiopoietin-like protein 3) in human hepatocytes results in decreased expression of gluconeogenic genes and reduced triacylglycerol-rich VLDL secretion upon insulin stimulation.

Homozygosity of loss-of-function mutations in ANGPTL3 (angiopoietin-like protein 3)-gene results in FHBL2 (familial combined hypolipidaemia, OMIM #605019) characterized by the reduction of all major plasma lipoprotein classes, which includes VLDL (very-low-density lipoprotein), LDL (low-density lipoprotein), HDL (high-density lipoprotein) and low circulating NEFAs (non-esterified fatty acids), glucose and insulin levels. Thus complete lack of ANGPTL3 in humans not only affects lipid metabolism, but also affects whole-body insulin and glucose balance. We used wild-type and ANGPTL3-silenced IHHs (human immortalized hepatocytes) to investigate the effect of ANGPTL3 silencing on hepatocyte-specific VLDL secretion and glucose uptake.

Elevated serum angiopoietin-like protein 6 in women with subsequent pregnancy-induced hypertension: a preliminary study.

Objective: Association of maternal angiopoietin-like protein 6 (Angptl6) levels with subsequent development of pregnancy-induced hypertension (PIH).

Methods: At 24 and 32 weeks of gestation in 47 relatively overweight (BMI ≥ 24 kg/m(2)), nulliparous pregnant women serum concentrations of Angptl6 were quantified prospectively. Insulin sensitivity and lipids were measured at 24 weeks.

Angptl3 deficiency is associated with increased insulin sensitivity, lipoprotein lipase activity, and decreased serum free fatty acids.

Objective: Angiopoietin-like 3 (Angptl3) is a regulator of lipoprotein metabolism at least by inhibiting lipoprotein lipase activity. Loss-of-function mutations in ANGPTL3 cause familial combined hypolipidemia through an unknown mechanism.

Approach And Results: We compared lipolytic activities, lipoprotein composition, and other lipid-related enzyme/lipid transfer proteins in carriers of the S17X loss-of-function mutation in ANGPTL3 and in age- and sex-matched noncarrier controls.

Genomic, transcriptomic, and lipidomic profiling highlights the role of inflammation in individuals with low high-density lipoprotein cholesterol.

Objective: Low high-density lipoprotein cholesterol (HDL-C) is associated with cardiometabolic pathologies. In this study, we investigate the biological pathways and individual genes behind low HDL-C by integrating results from 3 high-throughput data sources: adipose tissue transcriptomics, HDL lipidomics, and dense marker genotypes from Finnish individuals with low or high HDL-C (n=450).

Approach And Results: In the pathway analysis of genetic data, we demonstrate that genetic variants within inflammatory pathways were enriched among low HDL-C associated single-nucleotide polymorphisms, and the expression of these pathways upregulated in the adipose tissue of low HDL-C subjects.

Plasma homocysteine and the risk of venous thromboembolism: insights from the FIELD study.

Background: The lipid-lowering effect of fenofibrate is accompanied by a rise in plasma homocysteine (HCY), a potential risk factor for venous thromboembolism (VTE).This study investigated the relationship between HCY and the risk of VTE in patients treated with fenofibrate.

Methods: The relationship between HCY and deep-vein thrombosis or pulmonary embolism was investigated in 9522 participants of the 5-year Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) trial.

Angiopoietin-like 4 mediates PPAR delta effect on lipoprotein lipase-dependent fatty acid uptake but not on beta-oxidation in myotubes.

Peroxisome proliferator-activated receptor (PPAR) delta is an important regulator of fatty acid (FA) metabolism. Angiopoietin-like 4 (Angptl4), a multifunctional protein, is one of the major targets of PPAR delta in skeletal muscle cells. Here we investigated the regulation of Angptl4 and its role in mediating PPAR delta functions using human, rat and mouse myotubes.

OSBP-related proteins (ORPs) in human adipose depots and cultured adipocytes: evidence for impacts on the adipocyte phenotype.

Oxysterol-binding protein (OSBP) homologues, ORPs, are implicated in lipid homeostatic control, vesicle transport, and cell signaling. We analyzed here the quantity of ORP mRNAs in human subcutaneous (s.c.

Mutations in the ANGPTL3 gene and familial combined hypolipidemia: a clinical and biochemical characterization.

Context: Familial combined hypolipidemia causes a global reduction of plasma lipoproteins. Its clinical correlates and metabolic implications have not been well defined.

Objective: The objective of the study was to investigate the genetic, clinical, and metabolic characteristics of a cohort of subjects with familial combined hypolipidemia.

Serum angiopoietin-like 4 protein levels and expression in adipose tissue are inversely correlated with obesity in monozygotic twins.

Animal studies have suggested that angiopoietin-like 4 (Angptl4) regulates adiposity through central and peripheral mechanisms. The aim of this study was to investigate whether serum concentration and adipose tissue expression of Angptl4 are associated with obesity-related parameters in humans. Altogether, 75 dizygotic (DZ) and 46 monozygotic (MZ) twin pairs were studied, from the FinnTwin12 and FinnTwin16 cohorts.

The relationship between plasma angiopoietin-like protein 4 levels, angiopoietin-like protein 4 genotype, and coronary heart disease risk.

Objective: To investigate the relationship between angiopoietin-like protein 4 (Angptl4) levels, coronary heart disease (CHD) biomarkers, and ANGPTL4 variants.

Methods And Results: Plasma Angptl4 was quantified in 666 subjects of the Northwick Park Heart Study II using a validated ELISA. Seven ANGPTL4 single-nucleotide polymorphisms were genotyped, and CHD biomarkers were assessed in the whole cohort (N=2775).

Estimated glomerular filtration rate and albuminuria are independent predictors of cardiovascular events and death in type 2 diabetes mellitus: the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study.

Aims/hypothesis: We investigated effects of renal function and albuminuria on cardiovascular outcomes in 9,795 low-risk patients with diabetes in the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study.

Methods: Baseline and year 2 renal status were examined in relation to clinical and biochemical characteristics. Outcomes included total cardiovascular disease (CVD), cardiac and non-cardiac death over 5 years.

Human apoA-I increases macrophage foam cell derived PLTP activity without affecting the PLTP mass.

Background: phospholipid transfer protein (PLTP) plays important roles in lipoprotein metabolism and atherosclerosis and is expressed by macrophages and macrophage foam cells (MFCs). The aim of the present study was to determine whether the major protein from HDL, apoA-I, affects PLTP derived from MFCs.

Results: as cell model we used human THP-1 monocytes incubated with acetylated LDL, to generate MFC.

Ability of traditional lipid ratios and apolipoprotein ratios to predict cardiovascular risk in people with type 2 diabetes.

Aims/hypothesis: The apolipoprotein B (ApoB):apolipoprotein A (ApoA)-I ratio may be a better indicator of cardiovascular disease (CVD) risk in people with type 2 diabetes than traditional lipid risk markers (LDL-cholesterol, HDL-cholesterol and triacylglycerol), but whether the ApoB:ApoA-I ratio should be used to indicate lipid-lowering therapy is still debated.

Methods: The Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study randomised 9,795 patients with type 2 diabetes to fenofibrate (200 mg daily) or placebo and followed them up for a median of 5 years. We compared ApoB, ApoA-I, ApoAII and the ApoB:ApoA-I ratio with traditional lipid variables as predictors of CVD risk.

Increased apolipoprotein E level and reduced high-density lipoprotein mean particle size associate with low high-density lipoprotein cholesterol and features of metabolic syndrome.

The metabolic syndrome (MetS) pandemic predisposes patients to low high-density lipoprotein cholesterol (HDL-C). To successfully treat low HDL-C, there is an urgent need for a better understanding of the changes in HDL particles in the low-HDL-C state. Especially, apolipoprotein (apo) E metabolism in HDL particles is an emerging and important issue.

The role of phospholipid transfer protein in lipoprotein-mediated neutralization of the procoagulant effect of anionic liposomes.

Background: Serum has the ability to neutralize the procoagulant properties of anionic liposomes, with transfer of phospholipids (PLs) to both high-density lipoprotein (HDL) and low-density lipoprotein (LDL) particles. Phospholipid transfer protein (PLTP) mediates transfer of PLs between HDL and other lipoproteins and conversion of HDL into larger and smaller particles.

Objectives: To examine the role of PLTP in the neutralization of procoagulant liposomes.

A novel method to adjust efficacy estimates for uptake of other active treatments in long-term clinical trials.

Background: When rates of uptake of other drugs differ between treatment arms in long-term trials, the true benefit or harm of the treatment may be underestimated. Methods to allow for such contamination have often been limited by failing to preserve the randomization comparisons. In the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study, patients were randomized to fenofibrate or placebo, but during the trial many started additional drugs, particularly statins, more so in the placebo group.

Genetic association and interaction analysis of USF1 and APOA5 on lipid levels and atherosclerosis.

Objective: USF1 is a ubiquitous transcription factor governing the expression of numerous genes of lipid and glucose metabolism. APOA5 is a well-established candidate gene regulating triglyceride (TG) levels and has been identified as a downstream target of upstream stimulatory factor. No detailed studies about the effect of APOA5 on atherosclerotic lesion formation have been conducted, nor has its potential interaction with USF1 been examined.

Quantitation of serum angiopoietin-like proteins 3 and 4 in a Finnish population sample.

We have developed and validated quantitative ELISAs for human angiopoietin-like (ANGPTL)3 and 4 and correlated their serum levels with parameters of lipid and carbohydrate metabolism. For this study, we used a random subsample of the Health 2000 Health Examination Survey consisting of 125 men and 125 women, aged 30-94 years. The anthropometric and biochemical parameters of subjects were characterized in detail.