Dionne Grace, Calder Michele, Betts Dean H, Rafea Basim Abu, Watson Andrew J
Department of Obstetrics and Gynaecology, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London ON, N6A 5C1, Canada; The Children's Health Research Institute - Lawson Health Research Institute, London ON, N6C 2R5, Canada.
Department of Obstetrics and Gynaecology, Canada; The Children's Health Research Institute - Lawson Health Research Institute, London ON, N6C 2R5, Canada.
Gene Expr Patterns. 2022 Dec;46:119281. doi: 10.1016/j.gep.2022.119281. Epub 2022 Oct 13.
Obese women experience greater incidence of infertility, with reproductive tracts exposing preimplantation embryos to elevated free fatty acids (FFA) such as palmitic acid (PA) and oleic acid (OA). PA treatment impairs mouse preimplantation development in vitro, while OA co-treatment rescues blastocyst development of PA treated embryos. In the present study, we investigated the effects of PA and OA treatment on NRF2/Keap1 localization, and relative antioxidant enzyme (Glutathione peroxidase; Gpx1, Catalase; Cat, Superoxide dismutase; Sod1 and γ-Glutamylcysteine ligase catalytic unit; Gclc) mRNA levels, during in vitro mouse preimplantation embryo development. Female mice were superovulated, mated, and embryos cultured in the presence of bovine Serum albumin (BSA) control or PA, or OA, alone (each at 100 μM) or PA + OA combined (each at 100 μM) treatment. NRF2 displayed nuclear localization at all developmental stages, whereas Keap1 primarily displayed cytoplasmic localization throughout control mouse preimplantation development in vitro. Relative transcript levels of Nrf2, Keap1, and downstream antioxidants significantly increased throughout control mouse preimplantation development in vitro. PA treatment significantly decreased blastocyst development and the levels of nuclear NRF2, while OA and PA + OA treatments did not. PA and OA treatments did not impact relative mRNA levels of Nrf2, Keap1, Gpx1, Cat, Sod1 or Gclc. Our outcomes demonstrate that cultured mouse embryos display nuclear NRF2, but that PA treatment reduces nuclear NRF2 and thus likely impacts NRF2/KEAP1 stress response mechanisms. Further studies should investigate whether free fatty acid effects on NRF2/KEAP1 contribute to the reduced fertility displayed by obese patients.
肥胖女性的不孕发生率更高，其生殖道会使植入前胚胎暴露于高水平的游离脂肪酸（FFA）中，如棕榈酸（PA）和油酸（OA）。PA处理会损害小鼠体外植入前胚胎的发育，而OA联合处理可挽救PA处理胚胎的囊胚发育。在本研究中，我们调查了PA和OA处理对体外培养的小鼠植入前胚胎发育过程中NRF2/Keap1定位以及相关抗氧化酶（谷胱甘肽过氧化物酶；Gpx1、过氧化氢酶；Cat、超氧化物歧化酶；Sod1和γ-谷氨酰半胱氨酸连接酶催化亚基；Gclc）mRNA水平的影响。对雌性小鼠进行超排卵、交配，并将胚胎在牛血清白蛋白（BSA）对照、单独的PA或OA（均为100μM）或PA+OA联合（均为100μM）处理的条件下进行培养。NRF2在所有发育阶段均表现为核定位，而Keap1在体外对照小鼠植入前发育的整个过程中主要表现为细胞质定位。在体外对照小鼠植入前发育的整个过程中，Nrf2、Keap1和下游抗氧化剂的相对转录水平显著增加。PA处理显著降低了囊胚发育和核NRF2水平，而OA和PA+OA处理则没有。PA和OA处理对Nrf2、Keap1、Gpx1、Cat、Sod1或Gclc的相对mRNA水平没有影响。我们的结果表明，培养的小鼠胚胎显示有核NRF2，但PA处理会降低核NRF2水平，因此可能会影响NRF2/KEAP1应激反应机制。进一步的研究应调查游离脂肪酸对NRF2/KEAP1的影响是否导致肥胖患者生育能力下降。
