Navegando por Palavras-chave "Células do cumulus"

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    Efeito da adição do LH durante o estímulo ovariano e maturação oocitária no perfil lipídico de oócitos murinos
    (Universidade Federal de São Paulo (UNIFESP), 2016-02-02) Oleinki, Talitha Dinardo [UNIFESP]; Fraietta, Renato [UNIFESP]; http://lattes.cnpq.br/1545035937368744; http://lattes.cnpq.br/7699135183138091; Universidade Federal de São Paulo (UNIFESP)
    Introduction: The addition of LH in assisted reproduction aiming to obtain a higher number of viable follicles for the treatment is still controversial. A good embryonic development depends on the follicular growth and proper oocyte maturation. Because of that, the association between alkaline comet assay and the study of oocyte lipidomics may help to understand the biological processes involved in oocyte maturation and the influence of hormonal protocol. This study may contribute in the future with effective hormonal protocols, improving the quality of oocytes and pregnancy rates. Objective: Evaluate the effect of adding LH on DNA integrity of cumulus cells and on lipid profile of murine oocytes. Methods: Female mice C57BL / 6J 23 to 28 days old received three different stimulation protocols intraperitoneally (i.p.): (i) only PMSG; (ii) PMSG plus hCG (iii) PMSG plus LHr. After 48 hours of administration, immature oocytes were collected and cultured for 24 hours in three different culture medium for maturation: (i) only FSH; (ii) FSH plus hCG (iii) FSH plus LHr. After this period, the oocytes which had the first polar body were frozen at -80oC until the analysis by electrospray ionization (ESI) and cumulus cells were subjected to alkaline comet technique to measure the integrity of DNA. The principal component analysis and discriminant analysis by least squares were performed and 35 ions with greater representation were identified by the variable importance in the projection. Results: There was no statistical difference in the maturation rate and DNA fragmentation of cumulus cells in different groups analyzed. The fingerprinting analysis of the lipid profile of oocytes matured in vitro identified twenty lipids. The hyper-represented lipids in the group stimulated with the addition of hCG and matured in culture medium only with FSH (HF group) are: phosphatidylethanolamine, polyketide (flavonoid), sterol, phosphatidylserine, polyketide (ansamycin), sphingomyelin and phosphatidylcholine; in the group stimulated and matured in the presence of hCG (HH group) phosphatidylglycerol, phosphatidylserine, sphingolipids and triacylglycerol are hyper-represented; and in group stimulated with addition of LHr and matured in culture medium only with FSH (LF group) the polyketide (flavonoid) and sphingolipids are hyper-represented. Conclusion: The protocol used for hormonal stimulation and MIV modify the lipid profile of the oocyte, but does not alter the oocyte maturation rate and the DNA integrity of cumulus cells.
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    O papel da autofagia em oócitos bovinos expostos à hiperglicemia durante a maturação in vitro
    (Universidade Federal de São Paulo, 2022-01-27) Soares, Thays da Silva [UNIFESP]; Lopes, Fabíola Freitas de Paula [UNIFESP]; http://lattes.cnpq.br/0954914266701996; http://lattes.cnpq.br/8795253441230568
    Diabetes Mellitus (DM) is a disease that affects the population worldwide, being characterized by hyperglycemia, involving dysregulations of insulin production and/or action. Both DM and hyperglycemia can be harmful to the body. There is a proportional relationship between hyperglycemia and autophagic markers in oocytes from STZ-treated mice, but no studies related to the function of this relationship and its mechanisms were found. Bovine oocytes were used as an experimental model for humans due to similarities in gametogenesis and preimplantation embryonic development between these species. Therefore, this project aimed to determine the role of autophagy in bovine oocytes submitted to hyperglycemia condition during in vitro maturation, evaluating cumulus cell expansion and mitochondrial activity. Therefore, cumulus-oocyte complexes (COCs) collected from slaughterhouse animals were submitted to in vitro maturation (IVM) with 5.5 mM (control glucose group) or 20 mM glucose (hyperglycemic group) in the presence of 0 or 10 mM of autophagy inhibitor (3-methyladenine: 3-MA). For the first experiment, cumulus cell expansion was evaluated before (0h) and after IVM (21-24h). Image acquisition and analysis of the size of the OCCs were performed using the ImageJ program, version 1.53n. For the second experiment, the denuded oocytes were stained with Mitotracker Red to determine mitochondrial activity. The fluorescence intensity was quantified with the Image J 153n program. Inhibition of autophagy in COCs matured in hyperglycemic medium reduced the area of expansion of cumulus cells (P= 0.0051). Oocyte mitochondrial activity was increased by glucose concentration (P = 0.0330) and autophagy inhibitor (P = 0.0437). Inhibition of autophagy in COCs matured in hyperglycemic medium increased mitochondrial activity. In conclusion, autophagy may contribute to the protection of cumulus and oocyte cells against the deleterious effects of hyperglycemia