title: Anti-inflammatory effects of the hydroxycarboxylic acid receptor 2.
abstract: The hydroxycarboxylic acid receptors (HCA1-3) are a family of G-protein-coupled receptors that are critical for sensing endogenous intermediates of metabolism. All three receptors are predominantly expressed on adipocytes and mediate anti-lipolytic effects. In addition to adipocytes, HCA2 is highly expressed on immune cells, including macrophages, monocytes, neutrophils and dermal dendritic cells, among other cell types. The endogenous ligand for HCA2 is beta-hydroxybutyrate (β-OHB), a ketone body produced by the liver through β-oxidation when an individual is in a negative energy balance. Recent studies demonstrate that HCA2 mediates profound anti-inflammatory effects in a variety of tissues, indicating that HCA2 may be an important therapeutic target for treating inflammatory disease processes. This review summarizes the roles of HCA2 on inflammation in a number of tissues and clinical states.
authors.affiliation: Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States; Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States.
authors.forename: Emily C
authors.initials: EC
authors.lastname: Graff
authors.affiliation: Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States.
authors.forename: Han
authors.initials: H
authors.lastname: Fang
authors.affiliation: Department of Nutrition, Georgia State University, Atlanta, GA, United States.
authors.forename: Desiree
authors.initials: D
authors.lastname: Wanders
authors.affiliation: Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States. Electronic address: juddrob@auburn.edu.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Judd
mesh_terms: D000818:Animals; D050197:Atherosclerosis / Q000517:prevention & control; D003092:Colitis / Q000517:prevention & control; D003930:Diabetic Retinopathy / Q000517:prevention & control; D006801:Humans; D007249:Inflammation / Q000517:prevention & control*; D051379:Mice; D009369:Neoplasms / Q000517:prevention & control; D019636:Neurodegenerative Diseases / Q000517:prevention & control; D009525:Niacin / Q000627:therapeutic use; D009765:Obesity / Q000517:prevention & control; D043562:Receptors, G-Protein-Coupled / Q000032:analysis / Q000502:physiology*; D011978:Receptors, Nicotinic / Q000032:analysis / Q000502:physiology*
chemical_list: C530636:HCAR2 protein, human; D043562:Receptors, G-Protein-Coupled; D011978:Receptors, Nicotinic; D009525:Niacin
keywords: Beta-Hydroxybutyrate; GPR109a; HCA(2); Inflammation; Niacin