Mice lacking prostaglandin E receptor subtype 4 manifest disrupted lipid metabolism attributable to impaired triglyceride clearance

Yin Cai, Fan Ying, Erfei Song, Yu Wang, Aimin Xu, Paul M. Vanhoutte, Eva Hoi Ching Tang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

15 Citations (Scopus)

Abstract

Upon high-fat feeding, prostaglandin E receptor subtype 4 (EP4)-knockout mice gain less body weight than their EP4+/+ littermates. We investigated the cause of the lean phenotype. The mice showed a 68.8% reduction in weight gain with diminished fat mass that was not attributable to reduced food intake, fat malabsorption, or increased energy expenditure. Plasma triglycerides in the mice were elevated by 244.9%. The increase in plasma triglycerides was independent of changes in hepatic very low density lipoprotein (VLDL)-triglyceride production or intestinal chylomicron-triglyceride synthesis. However, VLDL-triglyceride clearance was drastically impaired in the EP4-knockout mice. The absence of EP4 in mice compromised the activation of lipoprotein lipase (LPL), the key enzyme responsible for trafficking of plasma triglycerides into peripheral tissues. Deficiency in EP4 reduced hepatic mRNA expression of the transcriptional factor cAMP response element binding protein H (by 36.8%) and LPL activators, including apolipoprotein (Apo)a5 (by 40.2%) and Apoc2 (by 61.3%). In summary, the lean phenotype of EP4-deficient mice resulted from reduction in adipose tissue and accretion of other peripheral organs caused by impaired triglyceride clearance. The findings identify a new metabolic dimension in the physiologic role played by endogenous EP4.

Original languageEnglish
Pages (from-to)4924-4936
Number of pages13
JournalFASEB Journal
Volume29
Issue number12
Early online date13 Aug 2015
DOIs
Publication statusPublished - Dec 2015
Externally publishedYes

Keywords

  • Apolipoprotein
  • Creb-h
  • High-fat diet
  • Hypertriglyceridemia
  • Lipoprotein lipase

ASJC Scopus subject areas

  • Biotechnology
  • Biochemistry
  • Molecular Biology
  • Genetics

Cite this