Flavonoid apigenin is an inhibitor of the NAD+ ase CD38: implications for cellular NAD+ metabolism, protein acetylation, and treatment of metabolic syndrome

Diabetes. 2013 Apr;62(4):1084-93. doi: 10.2337/db12-1139. Epub 2012 Nov 19.

Abstract

Metabolic syndrome is a growing health problem worldwide. It is therefore imperative to develop new strategies to treat this pathology. In the past years, the manipulation of NAD(+) metabolism has emerged as a plausible strategy to ameliorate metabolic syndrome. In particular, an increase in cellular NAD(+) levels has beneficial effects, likely because of the activation of sirtuins. Previously, we reported that CD38 is the primary NAD(+)ase in mammals. Moreover, CD38 knockout mice have higher NAD(+) levels and are protected against obesity and metabolic syndrome. Here, we show that CD38 regulates global protein acetylation through changes in NAD(+) levels and sirtuin activity. In addition, we characterize two CD38 inhibitors: quercetin and apigenin. We show that pharmacological inhibition of CD38 results in higher intracellular NAD(+) levels and that treatment of cell cultures with apigenin decreases global acetylation as well as the acetylation of p53 and RelA-p65. Finally, apigenin administration to obese mice increases NAD(+) levels, decreases global protein acetylation, and improves several aspects of glucose and lipid homeostasis. Our results show that CD38 is a novel pharmacological target to treat metabolic diseases via NAD(+)-dependent pathways.

MeSH terms

  • ADP-ribosyl Cyclase 1 / antagonists & inhibitors*
  • ADP-ribosyl Cyclase 1 / metabolism
  • Animals
  • Apigenin / chemistry
  • Apigenin / pharmacology*
  • Cell Line, Tumor
  • Gene Expression Regulation / drug effects*
  • Humans
  • Metabolic Syndrome / drug therapy*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Molecular Structure
  • NAD / metabolism*
  • Obesity / drug therapy
  • Obesity / metabolism
  • Quercetin / chemistry
  • Quercetin / pharmacology
  • Random Allocation
  • Sirtuin 1 / genetics
  • Sirtuin 1 / metabolism

Substances

  • NAD
  • Apigenin
  • Quercetin
  • ADP-ribosyl Cyclase 1
  • Sirt1 protein, mouse
  • Sirtuin 1