title: Vitamin E-analog Trolox prevents endoplasmic reticulum stress in frozen-thawed ovarian tissue of capuchin monkey (Sapajus apella).
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.
authors.affiliation: Laboratory of Wild Animal Biology and Medicine, Federal University of Pará, Belém, Brazil.
authors.forename: D C
authors.initials: DC
authors.lastname: Brito
authors.forename: A B
authors.initials: AB
authors.lastname: Brito
authors.forename: S R R A
authors.initials: SR
authors.lastname: Scalercio
authors.forename: S
authors.initials: S
authors.lastname: Percário
authors.forename: M S
authors.initials: MS
authors.lastname: Miranda
authors.forename: R M
authors.initials: RM
authors.lastname: Rocha
authors.forename: J A P
authors.initials: JA
authors.lastname: Diniz
authors.forename: I C
authors.initials: IC
authors.lastname: Oskam
authors.forename: R
authors.initials: R
authors.lastname: Van den Hurk
authors.forename: M C J
authors.initials: MC
authors.lastname: Paris
authors.forename: S F S
authors.initials: SF
authors.lastname: Domingues
authors.forename: R R
authors.initials: RR
authors.lastname: Santos
mesh_terms: D000818:Animals; D037282:Calreticulin / Q000378:metabolism; D002428:Cebus / Q000378:metabolism*; D002839:Chromans / Q000494:pharmacology*; D003451:Cryoprotective Agents / Q000494:pharmacology; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects*; D005260:Female; D005615:Freezing; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D010053:Ovary / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D013482:Superoxide Dismutase / Q000378:metabolism; D014810:Vitamin E / Q000031:analogs & derivatives*
chemical_list: D037282:Calreticulin; D002839:Chromans; D003451:Cryoprotective Agents; D018840:HSP70 Heat-Shock Proteins; D014810:Vitamin E; D013482:Superoxide Dismutase; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid