Hypoxic stress induces, but cannot sustain trophoblast stem cell differentiation to labyrinthine placenta due to mitochondrial insufficiency

Dysfunctional stem cell differentiation into placental lineages is associated with gestational diseases. Of the differentiated lineages available to trophoblast stem cells (TSC), elevated O2 and mitochondrial function are necessary to placental lineages at the maternal–placental surface and important in the etiology of preeclampsia. TSC lineage imbalance leads to embryonic failure during uterine implantation. Stress at implantation exacerbates stem cell depletion by decreasing proliferation and increasing differentiation. In an implantation site O2 is normally ~ 2%. In culture, exposure to 2% O2 and fibroblast growth factor 4 (FGF4) enabled the highest mouse TSC multipotency and proliferation. In contrast, hypoxic stress (0.5% O2) initiated the most TSC differentiation after 24 h despite exposure to FGF4. However, hypoxic stress supported differentiation poorly after 4–7 days, despite FGF4 removal. At all tested O2 levels, FGF4 maintained Warburg metabolism; mitochondrial inactivity and aerobic glycolysis. However, hypoxic stress suppressed mitochondrial membrane potential and maintained low mitochondrial cytochrome c oxidase (oxidative phosphorylation/OxPhos), and high pyruvate kinase M2 (glycolysis) despite FGF4 removal. Inhibiting OxPhos inhibited optimum differentiation at 20% O2. Moreover, adding differentiation-inducing hyperosmolar stress failed to induce differentiation during hypoxia. Thus, differentiation depended on OxPhos at 20% O2; hypoxic and hyperosmolar stresses did not induce differentiation at 0.5% O2. Hypoxia-limited differentiation and mitochondrial inhibition and activation suggest that differentiation into two lineages of the labyrinthine placenta requires O2 \u3e 0.5–2% and mitochondrial function. Stress-activated protein kinase increases an early lineage and suppresses later lineages in proportion to the deviation from optimal O2 for multipotency, thus it is the first enzyme reported to prioritize differentiation

Serine-threonine kinases and transcription factors active in signal transduction are detected at high levels of phosphorylation during mitosis in preimplantation embryos and trophoblast stem cells

Serine-threonine kinases and transcription factors play important roles in the G1-S phase progression of the cell cycle. Assays that use quantitative fluorescence by immunocytochemical means, or that measure band strength during Western blot analysis, may have confused interpretations if the intention is to measure G1-S phase commitment of a small subpopulation of phosphorylated proteins, when a larger conversion of the same population of proteins can occur during late G2 and M phases. In mouse trophoblast stem cells (TSC), a human placental cell line (HTR), and/or mouse preimplantation embryos, 8/19 ser- ine-threonine and tyrosine kinases, 3/8 transcription factors, and 8/14 phospho substrate and miscellaneous proteins were phosphorylated at higher levels in M phase than in interphase. Most phosphoproteins appeared to associate with the spindle complex during M phase, but one (p38MAPK) associated with the spindle pole and five (Cdx2, MEK1, 2, p27, and RSK1) associated with the DNA. Phosphorylation was detected throughout apparent metaphase, anaphase and telophase for some proteins, or for only one of these segments for others. The phosphorylation was from 2.1- to 6.2-fold higher during M phase compared with interphase. These data suggest that, when planning and interpreting quantitative data and perturbation experiments, consideration must be given to the role of serine-threonine kinases and transcription factors during decision making in M phase as well as in G1-S phase

Malignant Transformation of Endometrioma in a Woman with a History of Ovulation Induction and In Vitro Fertilization

Our aim is to document a case of endometrioid adenocarcinoma of the ovary found in an endometriotic cyst that was suspected on pelvic ultrasound in a patient with polycystic ovary syndrome, normal Ca125, and a recent history of ovulation induction for IVF. She underwent an exploratory laparotomy with left salpingo-oophorectomy and omental biopsies followed by reexploration, complete staging, and modified radical abdominal hysterectomy and right salpingo-oophorectomy. An endometrioma described as suspicious for malignancy by an experienced ultrasound examiner should prompt immediate referral to a gynecological oncologist irrespective of Ca125 levels especially in women with a history of ovulation induction and endometriosis

Selecting the most competent sperm for assisted reproductive technologies

International audienceThis paper discusses the variety of effective sperm selection techniques that have been developed for use in assisted reproductive technologies. Available methods for isolating the competent sperm in an ejaculate are outlined, as well as techniques for selecting single sperm for use in intracytoplasmic sperm injection procedures. Case-specific methods for selecting the most competent sperm are discussed, with reference to the potential causes of male factor infertility and guidance for the embryologist based on the issues present for each couple seeking treatment

Selecting the most competent sperm for assisted reproductive technologies

International audienceThis paper discusses the variety of effective sperm selection techniques that have been developed for use in assisted reproductive technologies. Available methods for isolating the competent sperm in an ejaculate are outlined, as well as techniques for selecting single sperm for use in intracytoplasmic sperm injection procedures. Case-specific methods for selecting the most competent sperm are discussed, with reference to the potential causes of male factor infertility and guidance for the embryologist based on the issues present for each couple seeking treatment

Selecting the most competent sperm for assisted reproductive technologies

International audienceThis paper discusses the variety of effective sperm selection techniques that have been developed for use in assisted reproductive technologies. Available methods for isolating the competent sperm in an ejaculate are outlined, as well as techniques for selecting single sperm for use in intracytoplasmic sperm injection procedures. Case-specific methods for selecting the most competent sperm are discussed, with reference to the potential causes of male factor infertility and guidance for the embryologist based on the issues present for each couple seeking treatment