Oat β-D-glucan ameliorates type II diabetes through TLR4/PI3K/AKT mediated metabolic axis

Int J Biol Macromol. 2023 Sep 30:249:126039. doi: 10.1016/j.ijbiomac.2023.126039. Epub 2023 Jul 27.

Abstract

Diabetes is one of the major global public health problems. Our previous results found that oat β-D-glucan exhibited ameliorative effects on diabetic mice, but the underlying mechanism is unclear. The present study indicates that oat β-D-glucan increased glycogen content, decreased glycogen synthase (GS) phosphorylation and increased hepatic glycogen synthase kinase 3β (GSK3β) phosphorylation for glycogen synthesis via PI3K/AKT/GSK3-mediated GS activation. Moreover, oat β-D-glucan inhibited gluconeogenesis through the PI3K/AKT/Foxo1-mediated phosphoenolpyruvate carboxykinase (PEPCK) decrease. In addition, oat β-D-glucan enhanced glucose catabolism through elevated protein levels of COQ9, UQCRC2, COXIV and ATP5F complexes involved in oxidative phosphorylation, as well as that of TFAM, a key regulator of mitochondrial gene expression. Importantly, our results showed that oat β-D-glucan maintained hepatic glucose balance via TLR4-mediated intracellular signal. After TLR4 blocking with anti-TLR4 antibody, oat β-D-glucan had almost no effect on high glucose-induced HepG2 cells. These data revealed that oat β-D-glucan maintains glucose balance by regulating the TLR4/PI3K/AKT signal pathway.

Keywords: Glucose balance; Oat β-D-glucan; TLR4/PI3K/AKT; Type II diabetes.

MeSH terms

  • Animals
  • Avena
  • Diabetes Mellitus, Experimental*
  • Diabetes Mellitus, Type 2* / metabolism
  • Glucans
  • Glucose / metabolism
  • Glycogen / metabolism
  • Glycogen Synthase Kinase 3
  • Glycogen Synthase Kinase 3 beta
  • Insulin Resistance*
  • Mice
  • Phosphatidylinositol 3-Kinases / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism
  • Toll-Like Receptor 4

Substances

  • Proto-Oncogene Proteins c-akt
  • Phosphatidylinositol 3-Kinases
  • Toll-Like Receptor 4
  • Glucans
  • Glycogen Synthase Kinase 3
  • Glucose
  • Glycogen
  • Glycogen Synthase Kinase 3 beta