Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide ( 1 ). Dyslipidemia has been shown to be one of the most potent risk factors for coronary heart disease (CHD) ( 2, 3 ). Dyslipidemia is characterized by elevated plasma cholesterol, especially low density lipoprotein cholesterol (LDL-c) levels. Management of dyslipidemia is considered throughout the primary and secondary prevention of CHD ( 4 ). For the past 20 years, the statin (3-hydroxy-3-methylglutaryl CoA reductase inhibitors) class of cholesterol-lowering drugs has been used for the treatment of hypercholesterolemia, either alone or in combination with other classes of lipid-lowering drugs Abstract In an attempt to understand the applicability of various animal models to dyslipidemia in humans and to identify improved preclinical models for target discovery and validation for dyslipidemia, we measured comprehensive plasma lipid profi les in 24 models. These included fi ve mouse strains, six other nonprimate species, and four nonhuman primate (NHP) species, and both healthy animals and animals with metabolic disorders. Dyslipidemic humans were assessed by the same measures. Plasma lipoprotein profi les, eight major plasma lipid fractions, and FA compositions within these lipid fractions were compared both qualitatively and quantitatively across the species. Given the importance of statins in decreasing plasma low-density lipoprotein cholesterol for treatment of dyslipidemia in humans, the responses of these measures to simvastatin treatment were also assessed for each species and compared with dyslipidemic humans. NHPs, followed by dog, were the models that demonstrated closest overall match to dyslipidemic humans. For the subset of the dyslipidemic population with high plasma triglyceride levels, the data also pointed to hamster and db/db mouse as representative models for practical use in target validation. Most traditional models, including rabbit, Zucker diabetic fatty rat, and the majority of mouse models, did not demonstrate overall similarity to dyslipidemic humans in this study . -

Diacylglycerol acyltransferase 2 (DGAT2) catalyzes the final step in triglyceride (TG) synthesis and has been shown to play a role in regulating hepatic very-low-density lipoprotein (VLDL) production in rodents. To explore the potential of DGAT2 as a therapeutic target for the treatment of dyslipidemia, we tested the effects of small-molecule inhibitors and gene silencing both in vitro and in vivo. Consistent with prior reports, chronic inhibition of DGAT2 in a murine model of obesity led to correction of multiple lipid parameters. In contrast, experiments in primary human, rhesus, and cynomolgus hepatocytes demonstrated that selective inhibition of DGAT2 has only a modest effect. Acute and chronic inhibition of DGAT2 in rhesus primates recapitulated the in vitro data yielding no significant effects on production of plasma TG or VLDL apolipoprotein B. These results call into question whether selective inhibition of DGAT2 is sufficient for remediation of dyslipidemia.

This article is available online at http://www.jlr.org Coronary atherosclerosis is the most prevalent disease in industrialized societies. Although numerous advances have been made in understanding the underlying causes of atherosclerosis and treatment thereof, this condition still remains the leading cause of death in the Western world. The most important risk factor for atherosclerosis is hyperlipidemia ( 1 ). Development of atherosclerosis correlates with high levels of low density lipoprotein cholesterol (LDL). As a result, several therapies have been developed for management of LDL levels. Among these, statins are most widely used ( 2 ). However, there is a range of statin response in humans, and a subset of familial hyperlipidemia patients is unresponsive to statins, prompting the development of additional therapies.

Atherosclerosis represents the most significant risk factor for coronary artery disease (CAD), the leading cause of death in developed countries. To better understand the pathogenesis of atherosclerosis, we applied a likeli hoodbased model selection method to infer genedisease causality relationships for the aortic lesion trait in a segregating mouse population demonstrating a spectrum of susceptibility to developing atherosclerotic lesions. We identified 292 genes that tested causal for aortic lesions from liver and adipose tissues of these mice, and we experimentally validated one of these candidate causal genes, complement component 3a receptor 1 (C3ar1), using a knockout mouse model. We also found that genes identified by this method overlapped with genes progressively regulated in the aortic arches of 2 mouse models of atherosclerosis during atherosclerotic lesion development. By comparing our gene set with findings from public human genomewide association studies (GWAS) of CAD and related traits, we found that 5 genes identified by our study overlapped with published studies in humans in which they were identified as risk factors for multiple atherosclerosisrelated pathologies, including myocardial infarction, serum uric acid levels, mean platelet volume, aortic root size, and heart failure. Candidate causal genes were also found to be enriched with CAD risk polymorphisms identified by the Wellcome Trust Case Control Consortium (WTCCC). Our findings therefore validate the ability of cau sality testing procedures to provide insights into the mechanisms underlying atherosclerosis development.

The development of the structure-activity studies leading to the discovery of anacetrapib is described. These studies focused on varying the substitution of the oxazolidinone ring of the 5-aryloxazolidinone system. Specifically, it was found that substitution of the 4-position with a methyl group with the cis-stereochemistry relative to the 5-aryl group afforded compounds with increased cholesteryl ester transfer protein (CETP) inhibition potency and a robust in vivo effect on increasing HDL-C levels in transgenic mice expressing cynomolgus monkey CETP.