Vitamina E-analógico Trolox evita estresse do retículo endoplasmático em tecido ovariano congelado-descongelado de macaco-prego (Sapajus apella)

Federal University of Pará. Laboratory of Wild Animal Biology and Medicine. Belém, PA, Brazil / Federal University of Pará. Animal Science Post -graduation Program. Belém, PA, Brazil.Federal University of Pará. Laboratory of Wild Animal Biology and Medicine. Belém, PA, Brazil / Federal University of Pará. Animal Science Post -graduation Program. Belém, PA, Brazil.Federal University of Pará. Laboratory of Wild Animal Biology and Medicine. Belém, PA, Brazil / Federal University of Pará. Animal Science Post -graduation Program. Belém, PA, Brazil.Federal University of Pará. Biological Sciences Institute. Oxidative Stress Research Laboratory. Belém, PA, Brazil.Federal University of Pará. Biological Sciences Institute. Laboratory of In Vitro Fertilization. Belém, PA, Brazil.Federal University of Pará. Biological Sciences Institute. Laboratory of Cell Ultrastructure. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Biokapital. Hamar, Norway.Utrecht University. Faculty of Veterinary Medicine. Department of Pathobiology. Utrecht, Netherlands.Institute for Breeding Rare and Endangered African Mammals. Edinburgh, UK.Federal University of Pará. Laboratory of Wild Animal Biology and Medicine. Belém, PA, Brazil / Federal University of Pará. Animal Science Post -graduation Program. Belém, PA, Brazil.Federal University of Pará. Laboratory of Wild Animal Biology and Medicine. Belém, PA, Brazil / Federal University of Pará. Animal Science Post -graduation Program. Belém, PA, Brazil.Utrecht University. Faculty of Veterinary Medicine. Department of Pathobiology. Utrecht, Netherlands.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 frozenthawed 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 Troloxfree 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