Collier Abby C, Yamauchi Yasuhiro, Sato Brittany L M, Rougée Luc R A, Ward Monika A
Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.C.C.); Department of Tropical Medicine, Medical Microbiology, and Pharmacology (A.C.C., B.L.M.S., L.R.A.R.), and Institute for Biogenesis Research (Y.Y., M.A.W.), John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii; and Natural Sciences and Mathematics, Chaminade University of Honolulu, Honolulu, Hawaii (B.L.M.S.)
Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.C.C.); Department of Tropical Medicine, Medical Microbiology, and Pharmacology (A.C.C., B.L.M.S., L.R.A.R.), and Institute for Biogenesis Research (Y.Y., M.A.W.), John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii; and Natural Sciences and Mathematics, Chaminade University of Honolulu, Honolulu, Hawaii (B.L.M.S.).
Drug Metab Dispos. 2014 Nov;42(11):1921-5. doi: 10.1124/dmd.114.059766. Epub 2014 Sep 8.
The UDP-glucuronosyltransferase (UGT) enzymes are critical for regulating nutrients, hormones, and endobiotics, as well as for detoxifying xenobiotics. Human and murine fetuses are known to express glucuronidation enzymes, but there are currently no data prior to implantation. Here we addressed this gap in knowledge and tested whether Ugt enzymes are already present in preimplantation-stage embryos. Blastocysts were obtained after in vitro fertilization with gametes from B6D2F1 hybrid mice and from embryo culture. Protein expression and localization were determined using pan-specific UGT1A and UGT2B, as well as anti-human isoform-specific antibodies. Immunofluorescence analysis showed that blastocysts expressed Ugt1a globally, in the cytoplasm and nuclei of all of the cells. Western blots demonstrated the presence of Ugt1a6 but not Ugt1a1, Ugt1a3, Ugt1a4, or Ugt1a9. The Ugt2b proteins were not detected by either assay. The level of Ugt activity in murine blastocysts was comparable with that of the adult human liver (per milligram of protein), but the activity of β-glucuronidase, an Ugt-partnering enzyme responsible for substrate regeneration, was lower. Altogether, these data confirm that Ugt1a proteins are present and active in preimplantation murine embryos and point to a potential role for these proteins in implantation and early embryonic and fetal development.
UDP-葡萄糖醛酸基转移酶（UGT）对于调节营养物质、激素和内源性物质，以及对外源性物质进行解毒至关重要。已知人类和小鼠胎儿会表达葡萄糖醛酸化酶，但目前尚无植入前的数据。在此，我们填补了这一知识空白，并测试了UGT酶是否已存在于植入前阶段的胚胎中。用B6D2F1杂交小鼠的配子进行体外受精并经胚胎培养后获得囊胚。使用泛特异性UGT1A和UGT2B以及抗人同工型特异性抗体来确定蛋白质表达和定位。免疫荧光分析表明，囊胚在所有细胞的细胞质和细胞核中均全局表达Ugt1a。蛋白质印迹法显示存在Ugt1a6，但不存在Ugt1a1、Ugt1a3、Ugt1a4或Ugt1a9。两种检测方法均未检测到Ugt2b蛋白。小鼠囊胚中的Ugt活性水平与成人肝脏（每毫克蛋白质）相当，但负责底物再生的Ugt伙伴酶β-葡萄糖醛酸酶的活性较低。总之，这些数据证实Ugt1a蛋白存在于植入前的小鼠胚胎中并具有活性，表明这些蛋白在植入以及早期胚胎和胎儿发育中可能发挥作用。
