Kynurenic Acid and Gpr35 Regulate Adipose Tissue Energy Homeostasis and Inflammation

Cell Metab. 2018 Feb 6;27(2):378-392.e5. doi: 10.1016/j.cmet.2018.01.004.


The role of tryptophan-kynurenine metabolism in psychiatric disease is well established, but remains less explored in peripheral tissues. Exercise training activates kynurenine biotransformation in skeletal muscle, which protects from neuroinflammation and leads to peripheral kynurenic acid accumulation. Here we show that kynurenic acid increases energy utilization by activating G protein-coupled receptor Gpr35, which stimulates lipid metabolism, thermogenic, and anti-inflammatory gene expression in adipose tissue. This suppresses weight gain in animals fed a high-fat diet and improves glucose tolerance. Kynurenic acid and Gpr35 enhance Pgc-1α1 expression and cellular respiration, and increase the levels of Rgs14 in adipocytes, which leads to enhanced beta-adrenergic receptor signaling. Conversely, genetic deletion of Gpr35 causes progressive weight gain and glucose intolerance, and sensitizes to the effects of high-fat diets. Finally, exercise-induced adipose tissue browning is compromised in Gpr35 knockout animals. This work uncovers kynurenine metabolism as a pathway with therapeutic potential to control energy homeostasis.

Keywords: Gpr35; Rgs14; adipose tissue; beige fat; brown fat; energy expenditure; exercise; inflammation; kynurenic acid.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes / metabolism
  • Adipose Tissue / metabolism*
  • Adipose Tissue / pathology*
  • Adipose Tissue, Beige / metabolism
  • Adipose Tissue, White / metabolism
  • Adiposity
  • Animals
  • Body Weight / drug effects
  • Cells, Cultured
  • Diet, High-Fat
  • Energy Metabolism*
  • Epididymis / metabolism
  • Gene Expression Profiling
  • Gene Expression Regulation
  • Glucose / metabolism
  • Homeostasis*
  • Inflammation / metabolism*
  • Inflammation / pathology*
  • Kynurenic Acid / metabolism*
  • Lymphocytes / metabolism
  • Male
  • Mice, Inbred C57BL
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha / metabolism
  • Physical Conditioning, Animal
  • RGS Proteins / metabolism
  • Receptors, Adrenergic, beta / metabolism
  • Receptors, G-Protein-Coupled / deficiency
  • Receptors, G-Protein-Coupled / metabolism*
  • Subcutaneous Fat / metabolism
  • Transcription, Genetic


  • GPR35 protein, mouse
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • RGS Proteins
  • Receptors, Adrenergic, beta
  • Receptors, G-Protein-Coupled
  • Rgs14 protein, mouse
  • Kynurenic Acid
  • Glucose