Protective effects of 7,8-dihydroxyflavone on retinal ganglion and RGC-5 cells against excitotoxic and oxidative stress

J Mol Neurosci. 2013 Jan;49(1):96-104. doi: 10.1007/s12031-012-9899-x. Epub 2012 Oct 7.

Abstract

A preferential loss of retinal ganglion cells (RGCs) is observed in glaucoma and optic neuritis. Loss of tropomyosin-related kinase receptor B (TrkB)-mediated signaling has been implicated in this degeneration. Our study indicates that 7,8-dihydroxyflavone (7,8 DHF) robustly upregulates the TrkB signaling in the primary rat RGCs and the retinal neuronal precursor RGC-5 cell line by promoting phosphorylation of TrkB receptor, leading to enhanced TrkB receptor tyrosine kinase activity. The flavonoid derivative 7,8 DHF acts a potent TrkB agonist and upregulates the downstream AKT and MAPK/ERK survival signaling pathways in a TrkB-dependent manner in both primary rat RGCs as well as the RGC-5 cell line. Excitotoxicity and oxidative injury have been alleged in the specific RGC degeneration in various forms of glaucoma. A novel finding of this study is that treatment with 7,8 DHF protects these cells significantly from excitotoxic and oxidative stress-induced apoptosis and cell death. 7,8 DHF also promotes neuritogenesis by stimulating neurite outgrowth, suggesting a possible therapeutic strategy for protection of RGCs in various optic neuropathies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Flavones / pharmacology*
  • MAP Kinase Signaling System
  • Neural Stem Cells / drug effects
  • Neural Stem Cells / metabolism
  • Neurites / drug effects
  • Neuroprotective Agents / pharmacology*
  • Oxidative Stress*
  • Phosphorylation
  • Rats
  • Rats, Sprague-Dawley
  • Receptor, trkB / agonists
  • Receptor, trkB / metabolism
  • Retinal Ganglion Cells / drug effects*
  • Retinal Ganglion Cells / metabolism

Substances

  • 6,7-dihydroxyflavone
  • Flavones
  • Neuroprotective Agents
  • Receptor, trkB