Diabetes Impairs Wnt3 Protein-induced Neurogenesis in Olfactory Bulbs via Glutamate Transporter 1 Inhibition

J Biol Chem. 2016 Jul 15;291(29):15196-211. doi: 10.1074/jbc.M115.672857. Epub 2016 May 20.

Abstract

Diabetes is associated with impaired cognitive function. Streptozotocin (STZ)-induced diabetic rats exhibit a loss of neurogenesis and deficits in behavioral tasks involving spatial learning and memory; thus, impaired adult hippocampal neurogenesis may contribute to diabetes-associated cognitive deficits. Recent studies have demonstrated that adult neurogenesis generally occurs in the dentate gyrus of the hippocampus, the subventricular zone, and the olfactory bulbs (OB) and is defective in patients with diabetes. We hypothesized that OB neurogenesis and associated behaviors would be affected in diabetes. In this study, we show that inhibition of Wnt3-induced neurogenesis in the OB causes several behavioral deficits in STZ-induced diabetic rats, including impaired odor discrimination, cognitive dysfunction, and increased anxiety. Notably, the sodium- and chloride-dependent GABA transporters and excitatory amino acid transporters that localize to GABAergic and glutamatergic terminals decreased in the OB of diabetic rats. Moreover, GAT1 inhibitor administration also hindered Wnt3-induced neurogenesis in vitro Collectively, these data suggest that STZ-induced diabetes adversely affects OB neurogenesis via GABA and glutamate transporter systems, leading to functional impairments in olfactory performance.

Keywords: GAT1; Wnt3; diabetes; insulin; neurodifferentiation; neurogenesis; neurotransmitter release; olfactory bulb.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes / metabolism
  • Astrocytes / pathology
  • Behavior, Animal
  • Biomarkers / metabolism
  • Cell Differentiation / drug effects
  • Diabetes Mellitus, Experimental / metabolism*
  • Diabetes Mellitus, Experimental / pathology
  • Down-Regulation / drug effects
  • Excitatory Amino Acid Transporter 2 / antagonists & inhibitors*
  • Excitatory Amino Acid Transporter 2 / metabolism
  • Glutamic Acid / metabolism
  • Insulin / pharmacology
  • Male
  • Neural Stem Cells / drug effects
  • Neural Stem Cells / metabolism
  • Neural Stem Cells / pathology
  • Neurogenesis* / drug effects
  • Neurons / drug effects
  • Neurons / metabolism
  • Neurons / pathology
  • Neurotransmitter Agents / metabolism
  • Olfactory Bulb / drug effects
  • Olfactory Bulb / metabolism*
  • Oligodendroglia / drug effects
  • Oligodendroglia / metabolism
  • Oligodendroglia / pathology
  • Rats, Inbred F344
  • Signal Transduction / drug effects
  • Wnt3 Protein / genetics
  • Wnt3 Protein / metabolism*

Substances

  • Biomarkers
  • Excitatory Amino Acid Transporter 2
  • Insulin
  • Neurotransmitter Agents
  • Wnt3 Protein
  • Glutamic Acid