Decreased GPIHBP1 protein levels in visceral adipose tissue partly underlie the hypertriglyceridemic phenotype in insulin resistance

PLoS One. 2018 Nov 8;13(11):e0205858. doi: 10.1371/journal.pone.0205858. eCollection 2018.

Abstract

GPIHBP1 is a protein localized at the endothelial cell surface that facilitates triglyceride (TG) lipolysis by binding lipoprotein lipase (LPL). Whether Glycosyl Phosphatidyl Inositol high density lipoprotein binding protein 1 (GPIHBP1) function is impaired and may underlie the hyperTG phenotype observed in type 2 diabetes is not yet established. To elucidate the mechanism underlying impaired TG homeostasis in insulin resistance state we studied the effect of insulin on GPIHBP1 protein expression in human microvascular endothelial cells (HMVEC) under flow conditions. Next, we assessed visceral adipose tissue GPIHBP1 protein expression in type 2 diabetes Lepr db/db mouse model as well as in subjects with ranging levels of insulin resistance. We report that insulin reduces the expression of GPIHBP1 protein in HMVECs. Furthermore, GPIHBP1 protein expression in visceral adipose tissue in Lepr db/db mice is significantly reduced as is the active monomeric form of GPIHBP1 as compared to Leprdb/m mice. A similar decrease in GPIHBP1 protein was observed in subjects with increased body weight. GPIHBP1 protein expression was negatively associated with insulin and HOMA-IR. In conclusion, our data suggest that decreased GPIHBP1 availability in insulin resistant state may hamper peripheral lipolysis capacity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Diabetes Mellitus, Type 2 / genetics*
  • Diabetes Mellitus, Type 2 / metabolism
  • Diabetes Mellitus, Type 2 / pathology
  • Disease Models, Animal
  • Endothelial Cells / metabolism
  • Gene Expression Regulation
  • Humans
  • Hypertriglyceridemia / genetics*
  • Hypertriglyceridemia / metabolism
  • Hypertriglyceridemia / pathology
  • Insulin / genetics
  • Insulin / metabolism
  • Insulin Resistance / genetics
  • Intra-Abdominal Fat / metabolism*
  • Lipolysis / genetics
  • Lipoprotein Lipase / genetics
  • Mice
  • Mice, Inbred NOD
  • Microvessels / metabolism
  • Receptors, Lipoprotein / genetics*
  • Triglycerides / genetics
  • Triglycerides / metabolism

Substances

  • GPIHBP1 protein, human
  • Insulin
  • Receptors, Lipoprotein
  • Triglycerides
  • Lipoprotein Lipase

Grants and funding

RPS was supported by a grant of the Dutch Heart Association (2010B242). MN is supported by a ZONMW-VIDI grant 2013 [016.146.327] and a Dutch Heart Foundation CVON Young Talent Grant 2013. MCP was supported by a FPU (Formación de Profesorado Universitario) Grant (AP2009-4537) from the Education Ministry, Madrid (Spain) and by Centros de Investigación Biomédica En Red (CB06/03/0018) of the Instituto de Salud Carlos III (ISCIII) Madrid, Spain.