Inflammation, obesity, and thrombosis

Blood. 2013 Nov 14;122(20):3415-22. doi: 10.1182/blood-2013-05-427708. Epub 2013 Oct 3.

Abstract

Clinical and epidemiological studies support a connection between obesity and thrombosis, involving elevated expression of the prothrombotic molecules plasminogen activator inhibitor-1 and tissue factor (TF) and increased platelet activation. Cardiovascular diseases and metabolic syndrome-associated disorders, including obesity, insulin resistance, type 2 diabetes, and hepatic steatosis, involve inflammation elicited by infiltration and activation of immune cells, particularly macrophages, into adipose tissue. Although TF has been clearly linked to a procoagulant state in obesity, emerging genetic and pharmacologic evidence indicate that TF signaling via G protein-coupled protease-activated receptors (PAR2, PAR1) additionally drives multiple aspects of the metabolic syndrome. TF-PAR2 signaling in adipocytes contributes to diet-induced obesity by decreasing metabolism and energy expenditure, whereas TF-PAR2 signaling in hematopoietic and myeloid cells drives adipose tissue inflammation, hepatic steatosis, and insulin resistance. TF-initiated coagulation leading to thrombin-PAR1 signaling also contributes to diet-induced hepatic steatosis and inflammation in certain models. Thus, in obese patients, clinical markers of a prothrombotic state may indicate a risk for the development of complications of the metabolic syndrome. Furthermore, TF-induced signaling could provide new therapeutic targets for drug development at the intersection between obesity, inflammation, and thrombosis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adipocytes / physiology
  • Adipose Tissue / pathology
  • Animals
  • Cardiovascular Diseases / epidemiology
  • Cardiovascular Diseases / etiology
  • Gene Expression Regulation
  • Humans
  • Inflammation / blood
  • Inflammation / complications
  • Inflammation / physiopathology*
  • Insulin Resistance / physiology
  • Macrophages / physiology
  • Metabolic Syndrome / epidemiology
  • Metabolic Syndrome / physiopathology
  • Mice
  • Mice, Obese
  • Models, Biological
  • Obesity / blood
  • Obesity / complications
  • Obesity / physiopathology*
  • Plasminogen Activator Inhibitor 1 / physiology*
  • Receptor, PAR-1 / physiology
  • Receptor, PAR-2 / physiology
  • Risk Factors
  • Signal Transduction / physiology
  • T-Lymphocytes, Regulatory / physiology
  • Thrombophilia / etiology*
  • Thrombophilia / physiopathology
  • Thromboplastin / physiology*
  • Thrombosis / etiology*
  • Thrombosis / physiopathology

Substances

  • Plasminogen Activator Inhibitor 1
  • Receptor, PAR-1
  • Receptor, PAR-2
  • SERPINE1 protein, human
  • Thromboplastin