Vitamin E-analog Trolox prevents endoplasmic reticulum stress in frozen-thawed ovarian tissue of capuchin monkey (Sapajus apella)

Cell Tissue Res. 2014 Feb;355(2):471-80. doi: 10.1007/s00441-013-1764-x. Epub 2013 Dec 22.

Abstract

Ovarian fragments were exposed to 0.5 M sucrose and 1 M ethylene glycol (freezing solution; FS) with or without selenium or Trolox. Histological and ultrastructural analyses showed that the percentages of normal follicles in control tissue and in tissue after exposure to FS + 50 μM Trolox were similar. Trolox prevented endoplasmic reticulum (ER)-related vacuolization, which is commonly observed in oocytes and stromal tissue after exposure to FS. From the evaluated stress markers, superoxide dismutase 1 (SOD1) was up-regulated in ovarian tissue exposed to FS + 10 ng/ml selenium. Ovarian fragments were subsequently frozen-thawed in the presence of FS with or without 50 μM Trolox, followed by in vitro culture (IVC). Antioxidant capacity in ovarian fragments decreased after freeze-thawing in Trolox-free FS compared with FS + 50 μM Trolox. Although freezing itself minimized the percentage of viable follicles in each solution, Trolox supplementation resulted in higher rates of viable follicles (67 %), even after IVC (61 %). Furthermore, stress markers SOD1 and ERp29 were up-regulated in ovarian tissue frozen-thawed in Trolox-free medium. Relative mRNA expression of growth factors markers was evaluated after freeze-thawing followed by IVC. BMP4, BMP5, CTGF, GDF9 and KL were down-regulated independently of the presence of Trolox in FS but down-regulation was less pronounced in the presence of Trolox. Thus, medium supplementation with 50 μM Trolox prevents ER stress and, consequently, protects ovarian tissue from ER-derived cytoplasmic vacuolization. ERp29 but not ERp60, appears to be a key marker linking stress caused by freezing-thawing and cell vacuolization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calreticulin / metabolism
  • Cebus / metabolism*
  • Chromans / pharmacology*
  • Cryoprotective Agents / pharmacology
  • Endoplasmic Reticulum Stress / drug effects*
  • Female
  • Freezing*
  • HSP70 Heat-Shock Proteins / metabolism
  • Ovary / drug effects*
  • Ovary / metabolism
  • Ovary / pathology*
  • Ovary / ultrastructure
  • Superoxide Dismutase / metabolism
  • Vitamin E / analogs & derivatives*

Substances

  • Calreticulin
  • Chromans
  • Cryoprotective Agents
  • HSP70 Heat-Shock Proteins
  • Vitamin E
  • Superoxide Dismutase
  • 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid