Accelerated Atherogenicity in Tangier Disease

Lipid Dysregulation in Tangier Disease: A Case Series and Metabolic Characterization

CONTEXT

Tangier disease (TD) is a rare, autosomal recessive genetic disorder associated with a deficiency in cellular cholesterol export leading to cholesterol accumulation in peripheral tissues. With approximately 150 described cases, the disease is significantly understudied, and the clinical presentation appears to be heterogenous.

OBJECTIVE

To investigate the phenotype and lipid metabolism in TD.

DESIGN

Multicenter cohort study.

PATIENTS

Four patients with TD.

MAIN OUTCOME MEASURES

Nuclear magnetic resonance (NMR)-based lipidomic and metabolomic analyses were performed in patients with TD and healthy controls.

RESULTS

While showing similar laboratory patterns with respect to high-density lipoprotein depletion, the clinical phenotypes of four TD patients were heterogenous with two patients diagnosed at 47 and 72 years having predominantly gastrointestinal and neurological phenotypes. Two previously undescribed variants (c.2418G>A, c.5055.del) were reported.Apart from pathognomonic changes in HDL composition, NMR spectroscopy revealed an increased abundance of VLDL with higher total lipid and cholesterol concentrations, pointing towards an impaired clearance of triglyceride-rich lipoproteins. Increased triglyceride-rich IDL supports impaired hepatic lipase activity, together with a CETP-mediated increase in LDL-triglycerides at higher abundance of large LDL subtypes and decreased small dense LDL.The lipid composition of HDL particles and LDL-1/LDL-4 remained the strongest differentiating factors as compared to healthy controls.

CONCLUSIONS

Clinical phenotypes of TD can be heterogeneous including gastrointestinal and neurological manifestations. Impaired triglyceride-rich lipoprotein clearance and hepatic lipase activity could be a pathophysiological hallmark of TD.

Role of ABCA1 in Atherosclerosis: Novel Mutations and Potential Plant-derived Therapies

ATP-binding cassette transporter A1 (ABCA1) is one of the key proteins regulating cholesterol homeostasis and playing a crucial role in atherosclerosis development. ABCA1 regulates the rate-limiting step of reverse cholesterol transport, facilitates the efflux of surplus intracellular cholesterol and phospholipids, and suppresses inflammation through several signalling pathways. At the same time, many mutations and Single Nucleotide Polymorphisms (SNPs) have been identified in the ABCA1 gene, which affects its biological function and is associated with several hereditary diseases (such as familial hypo-alpha-lipoproteinaemia and Tangier disease) and increased risk of cardiovascular diseases (CVDs). This review summarises recently identified mutations and SNPs in their connection to atherosclerosis and associated CVDs. Also, we discuss the recently described application of various plant-derived compounds to modulate ABCA1 expression in different in vitro and in vivo models. Herein, we present a comprehensive overview of the association of ABCA1 mutations and SNPs with CVDs and as a pharmacological target for different natural-derived compounds and highlight the potential application of these phytochemicals for treating atherosclerosis through modulation of ABCA1 expression.

Twin Study: The Factors Affecting the Serum LDL-C and HDL-C Levels and an RNA-Seq Analysis in Mononuclear Cells in Monozygotic Twins

AIM

A twin study is a valuable tool for elucidating the acquired factors against lifestyle diseases such as dyslipidemia, diabetes mellitus, and obesity. We aimed 1. to investigate the factors that affect low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) in monozygotic (MZ) twins, and 2. to identify genes which expression levels changed in pairs with large differences in LDL-C or HDL-C levels.

METHODS

The registered database at the Center for Twin Research, Osaka University, containing 263 pairs of MZ twins, was analyzed. 1. The effects of smoking, exercise, nutritional factors, and anthropometric and biochemical parameters on LDL-C or HDL-C levels were examined in MZ twins. 2. RNA sequencing in the peripheral blood mononuclear cells of 59 pairs was analyzed for large differences of LDL-C or HDL-C groups.

RESULTS

1. The ΔLDL-C levels were significantly associated with an older age, the ΔTG levels, and ΔBMI. ΔHDL-C levels were associated with the ΔBMI, ΔTG, ΔTP, and ΔLDL-C levels. The HDL-C levels were affected by smoking and exercise habits. The intakes of cholesterol and saturated fatty acids were not associated with the LDL-C or HDL-C levels. 2. An RNA sequencing analysis revealed that the expression of genes related to the TLR4 and IFNG pathways was suppressed in accordance with the HDL-C levels in the larger ΔHDL-C group among the 59 pairs.

CONCLUSION

We identified the factors affecting the LDL-C or HDL-C levels in monozygotic twins. In addition, some types of inflammatory gene expression in peripheral blood mononuclear cells were suppressed in accordance with the HDL-C levels, thus suggesting the importance of weight management and exercise habits in addition to dietary instructions to control the LDL-C or HDL-C levels.

A novel splicing variant in ABCA1 in the first reported Hong Kong Chinese patient with high-density lipoprotein deficiency

Summary

Low high-density lipoprotein cholesterol (HDL-C) is a risk factor for cardiovascular disease. Very low HDL-C levels (less than 20 mg/dL), however, were uncommonly seen and can be due to genetic defects involving the metabolic pathway of high-density lipoprotein (HDL). We encountered a 50-year-old Chinese man who was only noticed to have extremely low HDL-C levels after surviving recurrent episodes of myocardial infarction. Further workup revealed the undetectable level of apolipoprotein A-I, the absence of HDL on gel electrophoresis, and a novel heterozygous splicing variant in the ABCA1 gene, which was predicted to be pathogenic by in silico analysis. To the best of our knowledge, this is the first reported Hong Kong Chinese with ABCA1 deficiency and probable Tangier disease. The association of ABCA1 deficiency/Tangier disease and accelerated atherosclerosis is discussed.

Learning points

Clinicians should be aware of the differential diagnoses of very low HDL-C, which could be divided into genetic and acquired causes. Genetic low HDL syndromes include apoA-I deficiency, Tangier disease, and familial LCAT deficiency, each of which has characteristic clinical features and can be differentiated from the other further by apoA-I measurement, lipoprotein analysis, and genetic testing. Patients with ABCA1 deficiency and Tangier disease are at risk of premature coronary artery disease and should be aggressively screened and treated for cardiovascular risk factors and established cardiovascular diseases. Revascularization strategy and indications for coronary artery bypass grafting in patients with Tangier disease and coronary artery disease follow that as for patients without Tangier disease.

A novel dammarane triterpenoid alleviates atherosclerosis by activating the LXRα pathway

BACKGROUND

We have previously demonstrated that ginsenoside compound K can attenuate the formation of atherosclerotic lesions. Therefore, ginsenoside compound K has potential for atherosclerosis therapy. How to improve the druggability and enhance the antiatherosclerotic activity of ginsenoside compound K are the core problems in the prevention and treatment of atherosclerosis. CKN is a ginsenoside compound K derivative that was previously reported to have excellent antiatherosclerotic activity in vitro, and we have applied for international patents for it.

METHODS

Male C57BL/6 ApoE^-/- mice were fed a high-fat and high-choline diet to induce atherosclerosis and were subjected to in vivo studies. In vitro, the CCK-8 method was applied to evaluate cytotoxicity in macrophages. Foam cells were utilized, and cellular lipid determination was performed for in vitro studies. The area of atherosclerotic plaque and fatty infiltration of the liver were measured by image analysis. Serum lipid and liver function were determined by a seralyzer. Immunofluorescence and western blot analysis were conducted to explore the alterations in the expression levels of lipid efflux-related proteins. Molecular docking, reporter gene experiments and cellular thermal shift assays were used to verify the interaction between CKN and LXRα.

RESULTS

After confirming the therapeutic effects of CKN, molecular docking, reporter gene experiments and cellular thermal shift assays were used to predict and investigate the antiatherosclerotic mechanisms of CKN. CKN exhibited the greatest potency, with a 60.9% and 48.1% reduction in en face atherosclerotic lesions on the thoracic aorta and brachiocephalic trunk, reduced plasma lipid levels and decreased foam cell levels in the vascular plaque content in HHD-fed ApoE^-/- mice. Moreover, CKN in the present study may exert its antiatherosclerotic effects through activated ABCA1 by promoting LXRα nuclear translocation and reducing the adverse effects of LXRα activation.

CONCLUSIONS

Our results revealed that CKN prevented the formation of atherosclerosis in ApoE^-/- mice by activating the LXRα pathway.

Novel Selective PPARα Modulator Pemafibrate for Dyslipidemia, Nonalcoholic Fatty Liver Disease (NAFLD), and Atherosclerosis

Statins, the intestinal cholesterol transporter inhibitor (ezetimibe), and PCSK9 inhibitors can reduce serum LDL-C levels, leading to a significant reduction in cardiovascular events. However, these events cannot be fully prevented even when maintaining very low LDL-C levels. Hypertriglyceridemia and reduced HDL-C are known as residual risk factors for ASCVD. Hypertriglyceridemia and/or low HDL-C can be treated with fibrates, nicotinic acids, and n-3 polyunsaturated fatty acids. Fibrates were demonstrated to be PPARα agonists and can markedly lower serum TG levels, yet were reported to cause some adverse effects, including an increase in the liver enzyme and creatinine levels. Recent megatrials of fibrates have shown negative findings on the prevention of ASCVD, which were supposed to be due to their low selectivity and potency for binding to PPAR α. To overcome the off-target effects of fibrates, the concept of a selective PPARα modulator (SPPARMα) was proposed. Kowa Company, Ltd. (Tokyo, Japan), has developed pemafibrate (K-877). Compared with fenofibrate, pemafibrate showed more favorable effects on the reduction of TG and an increase in HDL-C. Fibrates worsened liver and kidney function test values, although pemafibrate showed a favorable effect on liver function test values and little effect on serum creatinine levels and eGFR. Minimal drug-drug interactions of pemafibrate with statins were observed. While most of the fibrates are mainly excreted from the kidney, pemafibrate is metabolized in the liver and excreted into the bile. It can be used safely even in patients with CKD, without a significant increase in blood concentration. In the megatrial of pemafibrate, PROMINENT, for dyslipidemic patients with type 2 diabetes, mild-to-moderate hypertriglyceridemia, and low HDL-C and LDL-C levels, the incidence of cardiovascular events did not decrease among those receiving pemafibrate compared to those receiving the placebo; however, the incidence of nonalcoholic fatty liver disease was lower. Pemafibrate may be superior to conventional fibrates and applicable to CKD patients. This current review summarizes the recent findings on pemafibrate.

Association of a Novel Homozygous Variant in ABCA1 Gene with Tangier Disease

Tangier disease (TD) is a rare autosomal recessive disorder caused by a variant in the ABCA1 gene, characterized by significantly reduced levels of plasma high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-1 (ApoA-I). TD typically leads to accumulation of cholesterol in the peripheral tissues and early coronary disease but with highly variable clinical expression. Herein, we describe a case study of a 59-year-old male patient with features typical of TD, in whom a likely pathogenic variant in the ABCA1 gene was identified by whole-exome sequencing (WES), identified for the first time as homozygous (NM_005502.4: c.4799A>G (p. His1600Arg)). In silico analysis including MutationTaster and DANN score were used to predict the pathogenicity of the variant and a protein model generated by SWISS-MODEL was built to determine how the homozygous variant detected in our patient may change the protein structure and impact on its function. This case study describes a homozygous variant of the ABCA1 gene, which is responsible for a severe form of TD and underlines the importance of using bioinformatics and genomics for linking genotype to phenotype and better understanding and accounting for the functional impact of genetic variations.

FTY720 Reduces Lipid Accumulation by Upregulating ABCA1 through Liver X Receptor and Sphingosine Kinase 2 Signaling in Macrophages

Formation of foam cells as a result of excess lipid accumulation by macrophages is a pathological hallmark of atherosclerosis. Fingolimod (FTY720) is an immunosuppressive agent used in clinical settings for the treatment of multiple sclerosis and has been reported to inhibit atherosclerotic plaque development. However, little is known about the effect of FTY720 on lipid accumulation leading to foam cell formation. In this study, we investigated the effects of FTY720 on lipid accumulation in murine macrophages. FTY720 treatment reduced lipid droplet formation and increased the expression of ATP-binding cassette transporter A1 (ABCA1) in J774 mouse macrophages. FTY720 also enhanced the expression of liver X receptor (LXR) target genes such as FASN, APOE, and ABCG1. In addition, FTY720-induced upregulation of ABCA1 was abolished by knockdown of sphingosine kinase 2 (SphK2) expression. Furthermore, we found that FTY720 treatment induced histone H3 lysine 9 (H3K9) acetylation, which was lost in SphK2-knockdown cells. Taken together, FTY720 induces ABCA1 expression through SphK2-mediated acetylation of H3K9 and suppresses lipid accumulation in macrophages, which provides novel insights into the mechanisms of action of FTY720 on atherosclerosis.

Current Diagnosis and Management of Tangier Disease

Tangier disease is a genetic disorder characterized by an absence or extremely low level of high-density lipoprotein (HDL)-cholesterol (HDL-C). It is caused by a dysfunctional mutation of the ATP-binding cassette transporter A1 (ABCA1) gene, the mandatory gene for generation of HDL particles from cellular cholesterol and phospholipids, and it appears in an autosomal recessive hereditary profile. To date, 35 cases have been reported in Japan and 109 cases outside Japan. With dysfunctional mutations in both alleles (homozygotes or compound heterozygotes), the HDL-C level is mostly less than 5 mg/dL and there is 10 mg/dL or less of apolipoprotein A-I (apoA-I), the major protein component of HDL. In patients with Tangier disease, major physical findings are orange-colored pharyngeal tonsils, hepatosplenomegaly, corneal opacity, lymphadenopathy, and peripheral neuropathy. Although patients tend to have decreased low-density lipoprotein (LDL)-cholesterol (LDL-C) levels, premature coronary artery disease is frequently observed. No specific curative treatment is currently available, so early identification of patients and preventing atherosclerosis development are crucial. Management of risk factors other than low HDL-C is also important, such as LDL-C levels, hypertension and smoking. Additionally, treatment for glucose intolerance might be required because impaired insulin secretion from pancreatic beta cells has occasionally been reported.

The Role of the ATP-Binding Cassette A1 (ABCA1) in Human Disease

Cholesterol homeostasis is essential in normal physiology of all cells. One of several proteins involved in cholesterol homeostasis is the ATP-binding cassette transporter A1 (ABCA1), a transmembrane protein widely expressed in many tissues. One of its main functions is the efflux of intracellular free cholesterol and phospholipids across the plasma membrane to combine with apolipoproteins, mainly apolipoprotein A-I (Apo A-I), forming nascent high-density lipoprotein-cholesterol (HDL-C) particles, the first step of reverse cholesterol transport (RCT). In addition, ABCA1 regulates cholesterol and phospholipid content in the plasma membrane affecting lipid rafts, microparticle (MP) formation and cell signaling. Thus, it is not surprising that impaired ABCA1 function and altered cholesterol homeostasis may affect many different organs and is involved in the pathophysiology of a broad array of diseases. This review describes evidence obtained from animal models, human studies and genetic variation explaining how ABCA1 is involved in dyslipidemia, coronary heart disease (CHD), type 2 diabetes (T2D), thrombosis, neurological disorders, age-related macular degeneration (AMD), glaucoma, viral infections and in cancer progression.

Orphan Peripheral Neuropathies

Objectives:

Generally, neuropathies of peripheral nerves are a frequent condition (prevalence 2–3%) and most frequently due to alcoholism, diabetes, renal insufficiency, malignancy, toxins, or drugs. However, the vast majority of neuropathies has orphan status. This review focuses on the etiology, frequency, diagnosis, and treatment of orphan neuropathies.

Methods:

Literature review

Results:

Rareness of diseases is not uniformly defined but in the US an orphan disease is diagnosed if the prevalence is <1:200000, in Europe if <5:10000. Most acquired and hereditary neuropathies are orphan diseases. Often the causative variant has been reported only in a single patient or family, particularly the ones that are newly detected (e.g. SEPT9, SORD). Among the complex neuropathies (hereditary multisystem disorders with concomitant neuropathies) orphan forms have been reported among mitochondrial disorders (e.g. NARP, MNGIE, SANDO), spinocerebellar ataxias (e.g. TMEM240), hereditary spastic paraplegias (e.g UBAP1), lysosomal storage disease (e.g. Schindler disease), peroxisomal disorders, porphyrias, and other types (e.g. giant axonal neuropathy, Tangier disease). Orphan acquired neuropathies include the metabolic neuropathies (e.g. vitamin-B1, folic acid), toxic neuropathies (e.g. copper, lithium, lead, arsenic, thallium, mercury), infectious neuropathies, immune-mediated (e.g. Bruns-Garland syndrome), and neoplastic/paraneoplastic neuropathies.

Conclusions:

Though orphan neuropathies are rare per definition they constitute the majority of neuropathies and should be considered as some of them are easy to identify and potentially treatable, as clarification of the underlying cause may contribute to the knowledge about etiology and pathophysiology of these conditions, and as the true prevalence may become obvious only if all ever diagnosed cases are reported.

Inborn errors of apolipoprotein A-I metabolism: implications for disease, research and development

PURPOSE OF REVIEW

We review current knowledge regarding naturally occurring mutations in the human apolipoprotein A-I (APOA1) gene with a focus on their clinical complications as well as their exploitation for the elucidation of structure-function-(disease) relationships and therapy.

RECENT FINDINGS

Bi-allelic loss-of-function mutations in APOA1 cause HDL deficiency and, in the majority of patients, premature atherosclerotic cardiovascular disease (ASCVD) and corneal opacities. Heterozygous HDL-cholesterol decreasing mutations in APOA1 were associated with increased risk of ASCVD in several but not all studies. Some missense mutations in APOA1 cause familial amyloidosis. Structure-function-reationships underlying the formation of amyloid as well as the manifestion of amyloidosis in specific tissues are better understood. Lessons may also be learnt from the progress in the treatment of amyloidoses induced by transthyretin variants. Infusion of reconstituted HDL (rHDL) containing apoA-I (Milano) did not cause regression of atherosclerosis in coronary arteries of patients with acute coronary syndrome. However, animal experiments indicate that rHDL with apoA-I (Milano) or apoA-I mimetic peptides may be useful for the treatment of heart failure of inflammatory bowel disease.

SUMMARY

Specific mutations in APOA1 are the cause of premature ASCVD or familial amyloidosis. Synthetic mimetics of apoA-I (mutants) may be useful for the treatment of several diseases beyond ASCVD.

Tangier disease: update for 2020

PURPOSE OF REVIEW

To appraise recent advances in our knowledge of the severe genetic HDL deficiency disorder, Tangier disease.

RECENT FINDINGS

While Tangier disease can cause premature atherosclerotic cardiovascular disease (ASCVD), new evidence suggests that heterozygous ABCA1 variant carriers are also at increased risk. Advances have been made in the study of the neurological abnormalities observed in Tangier disease, both in their assessment and the identification of potential new therapies.

SUMMARY

Tangier disease is an extremely rare condition and, as such, the published literature around its range of clinical manifestations, including peripheral neuropathy, premature ASCVD and platelet abnormalities is limited. Patient registries may assist in this regard.

Pemafibrate, a New Selective PPARα Modulator: Drug Concept and Its Clinical Applications for Dyslipidemia and Metabolic Diseases

PURPOSE OF REVIEW

Reduction of serum low-density lipoprotein cholesterol (LDL-C) levels by statins, ezetimibe and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors has been shown to significantly reduce cardiovascular events risk. However, fasting and postprandial hypertriglyceridemia as well as reduced high-density lipoprotein cholesterol (HDL-C) remain as residual risk factors of atherosclerotic cardiovascular diseases (ASCVD). To treat patients with hypertriglyceridemia and/or low HDL-C, drugs such as fibrates, nicotinic acids, and n-3 polyunsaturated fatty acids have been used. However, fibrates were demonstrated to cause side effects such as liver dysfunction and increase in creatinine levels, and thus large-scale clinical trials of fibrates have shown negative results for prevention of ASCVD. The failure could be attributed to their low selectivity and potency for binding to peroxisome proliferator-activated receptor (PPAR) α. To resolve these issues, the concept of selective PPARα modulator (SPPARMα) with a superior balance of efficacy and safety has been proposed and pemafibrate (K-877) has been developed.

RECENT FINDINGS

Pemafibrate, one of SPPARMsα, was synthesized by Kowa Company, Ltd. for better efficiency and safety. Clinical trials in Japan have established the superiority of pemafibrate on effects on serum triglycerides (TG) reduction and HDL-C elevation as well safety. Although available fibrates showed worsening of liver and kidney function test values, pemafibrate indicated improved liver function test values and was less likely to increase serum creatinine or decrease estimated glomerular filtration rate (eGFR). Very few drug-drug interactions were observed even when used concomitantly with statins. Furthermore, pemafibrate is metabolized in the liver and excreted into the bile, while many of available fibrates are mainly excreted from the kidney. Therefore, pemafibrate can be used safely even in patients with impaired renal function since there is no significant increase in its blood concentration. A large-scale trial of pemafibrate, PROMINENT, for dyslipidemic patients with type 2 diabetes is ongoing. Pemafibrate is one of novel SPPARMsα and has superior benefit-risk balance compared to conventional fibrates and can be applicable for patients for whom the usage of existing fibrates is difficult such as those who are taking statins or patients with renal dysfunction. In the current review, all the recent data on pemafibrate will be summarized.

Rare dyslipidaemias, from phenotype to genotype to management: a European Atherosclerosis Society task force consensus statement

Genome sequencing and gene-based therapies appear poised to advance the management of rare lipoprotein disorders and associated dyslipidaemias. However, in practice, underdiagnosis and undertreatment of these disorders are common, in large part due to interindividual variability in the genetic causes and phenotypic presentation of these conditions. To address these challenges, the European Atherosclerosis Society formed a task force to provide practical clinical guidance focusing on patients with extreme concentrations (either low or high) of plasma low-density lipoprotein cholesterol, triglycerides, or high-density lipoprotein cholesterol. The task force also recognises the scarcity of quality information regarding the prevalence and outcomes of these conditions. Collaborative registries are needed to improve health policy for the care of patients with rare dyslipidaemias.

[Inborn errors of high-density lipoprotein metabolism]

Both low and very high levels of high-density lipoprotein cholesterol (HDL-C) increase the risk of atherosclerotic cardiovascular disease (ASCVD) and shorten life expectancy. Low and high levels of HDL‑C are often caused by underlying diseases, lifestyle or medication, which should primarily be excluded. Much less frequently, monogenic diseases due to mutations in the APOA1, ABCA1 and LCAT genes are the cause of very low or unmeasurable HDL‑C levels or in the CETP, LIPC and SCARB1 genes for very high HDL‑C values. Genetic and detailed biochemical diagnostics should be considered, especially in cases of absolute HDL deficiency, early onset ASCVD or the presence of clinical symptoms or laboratory values characteristic for deficiencies of apolipoprotein A‑I (ApoA-I), lecithin cholesterol acyltransferase (LCAT) or Tangier disease. These included corneal opacities, xanthomas, large tonsils, hepatomegaly, peripheral neuropathy, proteinuria, anemia or thrombocytopenia. Sequencing of the APOA1 gene should also be considered in familial amyloidosis. There is no specific treatment for monogenic HDL diseases. Cholesterol and blood pressure lowering are indicated for the prevention of cardiovascular and renal complications.

Therapeutic FGF19 promotes HDL biogenesis and transhepatic cholesterol efflux to prevent atherosclerosis

Fibroblast growth factor (FGF)19, an endocrine hormone produced in the gut, acts in the liver to control bile acid synthesis. NGM282, an engineered FGF19 analog, is currently in clinical development for treating nonalcoholic steatohepatitis. However, the molecular mechanisms that integrate FGF19 with cholesterol metabolic pathways are incompletely understood. Here, we report that FGF19 and NGM282 promote HDL biogenesis and cholesterol efflux from the liver by selectively modulating LXR signaling while ameliorating hepatic steatosis. We further identify ABCA1 and FGF receptor 4 as mediators of this effect, and that administration of a HMG-CoA reductase inhibitor or a blocking antibody against proprotein convertase subtilisin/kexin type 9 abolished FGF19-associated elevations in total cholesterol, HDL cholesterol (HDL-C), and LDL cholesterol in db/db mice. Moreover, we show that a constitutively active MEK1, but not a constitutively active STAT3, mimics the effect of FGF19 and NGM282 on cholesterol change. In dyslipidemic Apoe-/- mice fed a Western diet, treatment with NGM282 dramatically reduced atherosclerotic lesion area in aortas. Administration of NGM282 to healthy volunteers for 7 days resulted in a 26% increase in HDL-C levels compared with placebo. These findings outline a previously unrecognized role for FGF19 in the homeostatic control of cholesterol and may have direct impact on the clinical development of FGF19 analogs.