Analysis of circulating angiopoietin-like protein 3 and genetic variants in lipid metabolism and liver health: the DiOGenes study

Anne Lundby Hess; Jérôme Carayol; Trine Blædel; Jörg Hager; Alessandro Di Cara; Arne Astrup; Wim H M Saris; Lesli Hingstrup Larsen; Armand Valsesia

doi:10.1186/s12263-018-0597-3

Analysis of circulating angiopoietin-like protein 3 and genetic variants in lipid metabolism and liver health: the DiOGenes study

Genes Nutr. 2018 Apr 2:13:7. doi: 10.1186/s12263-018-0597-3. eCollection 2018.

Authors

Affiliations

¹ 1The Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark.
² Nestlé Institute of Health Sciences, Lausanne, Switzerland.
³ Precision for Medicine, Geneva, Switzerland.
⁴ 4The Department of Human Biology, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, Maastricht, Netherlands.

^# Contributed equally.

Abstract

Background: Angiopoietin-like protein 3 (ANGPTL3), a liver-derived protein, plays an important role in the lipid and lipoprotein metabolism. Using data available from the DiOGenes study, we assessed the link with clinical improvements (weight, plasma lipid, and insulin levels) and changes in liver markers, alanine aminotransferase, aspartate aminotransferase (AST), adiponectin, fetuin A and B, and cytokeratin 18 (CK-18), upon low-calorie diet (LCD) intervention. We also examined the role of genetic variation in determining the level of circulating ANGPTL3 and the relation between the identified genetic markers and markers of hepatic steatosis.

Methods: DiOGenes is a multicenter, controlled dietary intervention where obese participants followed an 8-week LCD (800 kcal/day, using a meal replacement product). Plasma ANGPTL3 and liver markers were measured using the SomaLogic (Boulder, CO) platform. Protein quantitative trait locus (pQTL) analyses assessed the link between more than four million common variants and the level of circulating ANGPTL3 at baseline and changes in levels during the LCD intervention.

Results: Changes in ANGPTL3 during weight loss showed only marginal association with changes in triglycerides (nominal p = 0.02) and insulin (p = 0.04); these results did not remain significant after correcting for multiple testing. However, significant association (after multiple-testing correction) were observed between changes in ANGPTL3 and AST during weight loss (p = 0.004) and between ANGPTL3 and CK-18 (baseline p = 1.03 × 10^-7, during weight loss p = 1.47 × 10^-13). Our pQTL study identified two loci significantly associated with changes in ANGPTL3. One of these loci (the APOA4-APOA5-ZNF259-BUD13 gene cluster) also displayed significant association with changes in CK-18 levels during weight loss (p = 0.007).

Conclusion: We clarify the link between circulating levels of ANGPTL3 and specific markers of liver function. We demonstrate that changes in ANGPLT3 and CK-18 during LCD are under genetic control from trans-acting variants. Our results suggest an extended function of ANGPTL3 in the inflammatory state of liver steatosis and toward liver metabolic processes.

Keywords: Angiopoietin-like protein 3; Lipid metabolism; Lipoprotein lipase; Liver markers; Liver steatosis; Protein quantitative trait locus; Single nucleotide polymorphisms.