Effects of Estrogen and Phytoestrogen Treatment on an In Vitro Model of Recurrent Stroke on HT22 Neuronal Cell Line

Cell Mol Neurobiol. 2017 Apr;37(3):405-416. doi: 10.1007/s10571-016-0372-1. Epub 2016 Apr 8.

Abstract

An increase of stroke incidence occurs in women with the decline of estrogen levels following menopause. This ischemic damage may recur, especially soon after the first insult has occurred. We evaluated the effects of estrogen and phytoestrogen treatment on an in vitro recurrent stroke model using the HT22 neuronal cell line. HT22 cells were treated with 17β-estradiol or genistein 1 h after the beginning of the first of two oxygen and glucose deprivation/reoxygenation (OGD/R) cycles. During the second OGD, there was a deterioration of some components of the electron transport chain, such as cytochrome c oxidase subunit 1 with a subsequent increase of reactive oxygen species (ROS) production. Accordingly, there was also an increase of apoptotic phenomena demonstrated by poly(ADP-ribose) polymerase 1 cleavage, Caspase-3 activity, and Annexin V levels. The recurrent ischemic injury also raised the hypoxia-inducible factor 1α and glucose transporter 1 levels, as well as the ratio between the lipidated and cytosolic forms of microtubule-associated protein 1A/1B-light chain 3 (LC3-II/LC3-I). We found a positive effect of estradiol and genistein treatment by partially preserving the impaired cell viability after the recurrent ischemic injury; however, this positive effect does not seem to be mediated neither by blocking apoptosis processes nor by decreasing ROS production. This work contribute to the better understanding of the molecular mechanisms triggered by recurrent ischemic damage in neuronal cells and, therefore, could help with the development of an effective treatment to minimize the consequences of this pathology.

Keywords: 17β-estradiol; Apoptosis; Genistein; HT22 cells; Oxidative metabolism; Recurrent stroke.

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Cell Line
  • Cell Survival / drug effects
  • Electron Transport Complex IV / metabolism
  • Estrogens / pharmacology
  • Estrogens / therapeutic use*
  • Glucose / deficiency
  • Glucose Transporter Type 1 / metabolism
  • Glucose Transporter Type 3 / metabolism
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Mice
  • Microtubule-Associated Proteins / metabolism
  • Models, Biological*
  • Neurons / drug effects
  • Neurons / metabolism
  • Neurons / pathology*
  • Oxidation-Reduction / drug effects
  • Oxygen / pharmacology
  • Phytoestrogens / pharmacology
  • Phytoestrogens / therapeutic use*
  • Poly(ADP-ribose) Polymerases / metabolism
  • Stroke / drug therapy*
  • Stroke / pathology

Substances

  • Estrogens
  • Glucose Transporter Type 1
  • Glucose Transporter Type 3
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Microtubule-Associated Proteins
  • Phytoestrogens
  • Slc2a1 protein, mouse
  • Slc2a3 protein, mouse
  • Electron Transport Complex IV
  • Poly(ADP-ribose) Polymerases
  • Glucose
  • Oxygen