Bunpei Ishizuka

Hippo signaling disruption and Akt stimulation of ovarian follicles for infertility treatment.

Significance Human ovaries hold follicles containing oocytes. When follicles mature, they release eggs for fertilization. Patients with primary ovarian insufficiency develop menopausal symptoms at less than 40 y of age. They have few remaining follicles and their only chance for bearing a baby is through egg donation. Kawamura et al. demonstrated that Hippo and Akt signaling pathways regulate follicle growth. Using an in vitro activation approach, they first removed ovaries from infertile patients, followed by fragmentation to disrupt Hippo signaling and drug treatment to stimulate Akt signaling. After grafting ovarian tissues back to patients, they found rapid follicle growth in some patients and successfully retrieved mature eggs. After in vitro fertilization and embryo transfer, a live birth is now reported. Primary ovarian insufficiency (POI) and polycystic ovarian syndrome are ovarian diseases causing infertility. Although there is no effective treatment for POI, therapies for polycystic ovarian syndrome include ovarian wedge resection or laser drilling to induce follicle growth. Underlying mechanisms for these disruptive procedures are unclear. Here, we explored the role of the conserved Hippo signaling pathway that serves to maintain optimal size across organs and species. We found that fragmentation of murine ovaries promoted actin polymerization and disrupted ovarian Hippo signaling, leading to increased expression of downstream growth factors, promotion of follicle growth, and the generation of mature oocytes. In addition to elucidating mechanisms underlying follicle growth elicited by ovarian damage, we further demonstrated additive follicle growth when ovarian fragmentation was combined with Akt stimulator treatments. We then extended results to treatment of infertility in POI patients via disruption of Hippo signaling by fragmenting ovaries followed by Akt stimulator treatment and autografting. We successfully promoted follicle growth, retrieved mature oocytes, and performed in vitro fertilization. Following embryo transfer, a healthy baby was delivered. The ovarian fragmentation–in vitro activation approach is not only valuable for treating infertility of POI patients but could also be useful for middle-aged infertile women, cancer patients undergoing sterilizing treatments, and other conditions of diminished ovarian reserve.

THE EFFECT OF MELATONIN ON IN VITRO FERTILIZATION AND EMBRYO DEVELOPMENT IN MICE

To examine the effect of melatonin on in vitro fertilization and embryonic development, mouse embryos after insemination in vitro were cultured in a physiological medium with or without melatonin. Melatonin increased the fertilization rate significantly at a concentration between 10−6 and 10−4 M (27.6 vs. 43.9 or 40.4%, P<0.01). Furthermore, a significant increase in the rate of embryos reaching the four‐cell stage (16.0 vs. 26.7%, P<0.01), the eight‐cell stage (12.1 vs. 25.8 or 23.5%, P<0.01), and blastulation (8.9 vs. 23.5 or 17.5%, P<0.01) was observed when the embryos were cultured in a medium containing 10−8 or 10−6 M melatonin. These results demonstrate that melatonin supports fertilization and early embryo development after in vitro fertilization.

Recommendations for fertility preservation in patients with lymphoma, leukemia, and breast cancer

Fertility issues should be addressed to all patients in reproductive age before cancer treatment. In men, cryopreservation of sperm should be offered to all cancer patients in reproductive age regardless of the risk of gonadal failure. In women, the recommendation of fertility preservation should be individualized based on multiple factors such as the urgency of treatment, the age of the patient, the marital status, the regimen and dosage of cancer treatment.

A Natural S-Equol Supplement Alleviates Hot Flushes and Other Menopausal Symptoms in Equol Nonproducing Postmenopausal Japanese Women

OBJECTIVE The objective of this clinical trial was to examine the efficacy of a supplement containing natural S-(-)equol, a daidzein metabolite, in reducing menopausal symptoms. METHODS In this multicenter, double-blind placebo-controlled trial, 160 equol nonproducing, postmenopausal Japanese women who experienced at least 1 hot flush/day were randomly assigned to consume 10 mg/day S-(-)equol (n=77 women) or placebo (n=83 women) for 12 weeks. Participants completed a standardized menopausal symptom checklist and rated five common menopause symptoms by a visual analog scale at baseline, week 12, and week 18 (6-week postintervention). Physical, blood, and urine examinations were conducted. One hundred twenty-six women completed the study. RESULTS At baseline, daily hot flush frequency was 2.9±2.1 for the S-(-)equol group and 3.2±2.4 for the placebo group. After the 12-week intervention, the S-(-)equol group had a greater decrease from baseline in hot flush frequency compared with the placebo group (-1.9±1.8/day, -58.7%, vs. -1.0±2.0/day, -34.5%, p=0.009). The severity of hot flushes and neck or shoulder muscle stiffness significantly decreased in the S-(-)equol group compared with the placebo group. No changes in clinical parameters or serious adverse effects were reported. CONCLUSIONS This is the first trial to show beneficial effects of a 10-mg natural S-(-)equol supplement consumed daily for 12 weeks on major menopausal symptoms, specifically, hot flushes and neck or shoulder muscle stiffness, in postmenopausal Japanese women. This supplement offers a promising alternative for management of menopausal symptoms.

Differential growth inhibitory effect of melatonin on two endometrial cancer cell lines.

The effect of melatonin on endometrial cancer cell growth was investigated using two cell lines, SNG‐II and Ishikawa, which are different in their estrogen receptor status. A physiological concentration of melatonin (10−9 M) showed no growth inhibitory effect on SNG‐II cells, which are estrogen receptor‐negative at all cell densities and incubation times. In contrast, melatonin significantly inhibited Ishikawa cells, which are estrogen receptor‐positive at all cell densities tested after 96 hr incubation. The greatest inhibition of Ishikawa cell growth was observed at 10−9 M melatonin, compared with other supra (10−6, 10−8 M) or subphysiological concentrations (10−10, 10−12 M). This growth inhibitory effect of melatonin on Ishikawa cells was completely blocked by 10−10 to 10−8 M concentrations of 17‐β estradiol administration. Pretreatment with luzindole, which is a selective melatonin receptor antagonist, prior to the addition of melatonin also blocked the inhibitory effect of melatonin on Ishikawa cells. This is the first study to demonstrate an anti‐proliferative effect of physiological melatonin on endometrial cancer cells in vitro. The present study revealed that melatonin also inhibits the growth of estrogen receptor positive endometrial cancer cells and that this effect of the pineal indole may be mediated by both steroid and melatonin receptors.

Detection of melatonin and serotonin N-acetyltransferase and hydroxyindole-O-methyltransferase activities in rat ovary.

Melatonin (N-acetyl-5-methoxytryptamine) and the activities of two melatonin-synthesizing enzymes, serotonin N-acetyltransferase (acetyl coenzyme A: arylalkylamine N-acetyltransferase EC 2.3.1.87; NAT) and hydroxyindole-O-methyltransferase (S-adenosyl-L-methionine: N-acetylserotonin-O-methyltransferase EC 2.1.1.4; HIOMT), were assayed in extracts of ovaries obtained from virgin Wistar-derived rats (7-9 week-old) during the light period of a 12 h light/12 h dark cycle. Melatonin was detected in the rat ovary using reverse-phase high-performance liquid chromatography (HPLC) coupled with fluorometric detection and radioimmunoassay (RIA). In addition, NAT and HIOMT activities were found in rat ovary. The apparent Michaelis constants (Km) for the substrates of NAT and HIOMT in the rat ovary were similar to those reported for the pineal gland and retina. These data suggest that the rat ovary, like the pineal gland and the retina, may synthesize melatonin from serotonin by the sequential action of NAT and HIOMT.

Assessment of long-term function of heterotopic transplants of vitrified ovarian tissue in cynomolgus monkeys

BACKGROUND Ovarian tissue cryopreservation by rapid cooling (vitrification) is a convenient fertility preservation option. However, the progress of vitrified ovarian tissue after transplantation is not well understood in primates. METHODS For tissues from cynomolgus monkeys, we used closed straw vitrification and open cryosupport vitrification in which tissues are immersed directly into liquid nitrogen. Following warming, ovarian cortical pieces were autotransplanted and their function was monitored by computed tomography (CT), hormone assays and oocyte recovery, ICSI and embryo transfers (ETs). RESULTS Hormone cycles were restored in 6 of 7 animals in a mean of 126 days with no significant difference between the two vitrification regimens. The presence of new blood vessels supplying the grafted ovarian tissue was confirmed by contrast-enhanced CT. Oocyte retrieval from two monkeys after transplantation of the ovarian cortex vitrified by cryosupport vitrification yielded a total of nine oocytes of which six fertilized after ICSI, but ETs did not lead to any pregnancies. CONCLUSIONS This work shows that CT can give insight into ovarian function after heterotopic transplantation, and that heterotopic autografts of vitrified ovarian cortex can give rise to long-term ovarian function and embryos in a primate model. It remains to be established how outcomes following rapid vitrification compared with outcomes following conventional slow cooling procedures.

Successful differentiation to T cells, but unsuccessful B-cell generation, from B-cell-derived induced pluripotent stem cells

Forced expression of certain transcription factors in somatic cells results in generation of induced pluripotent stem (iPS) cells, which differentiate into various cell types. We investigated T-cell and B-cell lineage differentiation from iPS cells in vitro. To evaluate the impact of iPS cell source, murine splenic B-cell-derived iPS (B-iPS) cells were generated after retroviral transduction of four transcription factors (Oct4, Sox2, Klf4 and c-Myc). B-iPS cells were identical to embryonic stem (ES) cells and mouse embryonic fibroblast (MEF)-derived iPS cells in morphology, ES cell marker expression as well as teratoma and chimera mouse formation. Both B-iPS and MEF-derived iPS cells differentiated into lymphocytes in OP9 co-culture systems. Both efficiently differentiated into T-cell lineage that produced IFN-γ on T-cell receptor stimulation. However, iPS cells including B-iPS cells were relatively resistant to B-cell lineage differentiation. One of the reasons of the failure of B-cell lineage differentiation seemed due to a defect of Pax5 expression in the differentiated cells. Therefore, current in vitro differentiation systems using iPS cells are sufficient for inducing T-cell but not B-cell lineage.

The rat oocyte synthesises melatonin

Melatonin (N-acetyl-5-methoxytryptamine) is an indoleamine originally identified in the pineal gland, where it is synthesised enzymatically from serotonin (5-hydroxytryptamine) by the sequential action of arylalkylamine N-acetyltransferase (AANAT) and acetylserotonin O-methyltransferase (ASMT; also known as hydroxyindole O-methyltransferase). Melatonin directly affects ovarian functions and previous studies have suggested that melatonin is synthesised in the ovary. In the present study, we examined whether AANAT and ASMT are expressed in the adult rat ovary. Reverse transcription-polymerase chain reaction analyses demonstrated that both AANAT and ASMT mRNAs are expressed in the ovary. Western blotting for AANAT protein showed that the ovary, like the pineal gland, contains this enzymatic protein with a molecular mass of 24kDa. Immunohistochemistry revealed that the AANAT protein is localised to the oocyte, corpus luteum and medulla, including mast cells. AANAT protein was found in oocytes at all stages of follicular development, and its levels in oocytes increased progressively throughout follicular development. Furthermore, isolated oocytes metabolised exogenous serotonin to melatonin. These findings demonstrate that melatonin is synthesised from serotonin in oocytes. Melatonin synthesised in the oocyte may be implicated in its own growth or maturation, for example, by acting as a calmodulin antagonist or an antioxidant.

Effects of vitrification solutions and equilibration times on the morphology of cynomolgus ovarian tissues

This study assessed the effects of vitrification solutions and equilibration times on morphology of cynomolgus ovarian tissues. Ovarian cortical sections (0.1-0.2 cm thickness) of seven cynomolgus monkeys were randomly allocated to either a control group or one of six vitrification groups. Ovarian tissue sections were vitrified ultra-rapidly by placing them directly into liquid nitrogen using two different vitrification solutions (VSEGP: 5.64 mol/l ethylene glycol+5% (w/v) polyvinylpyrrolidone+0.5 mol/l sucrose; and VSED: 3.22 mol/l ethylene glycol+2.56 mol/l dimethylsulphoxide+0.5 mol/l sucrose) after three different exposure times (5-20 min). After warming, follicle morphology was analysed using light and transmission electron microscopy. The proportion of morphologically normal follicles vitrified using VSED after a 5-min exposure was lower (P<0.05) than those vitrified by other conditions. The proportion of normally structured mitochondria in oocytes of preantral follicles vitrified after a 5-min exposure to VSED (56%) was lower (P<0.01) than those vitrified by other conditions (78-88%). Following tissue vitrification with VSED, the surface ratio of lysosome was increased compared with non-vitrified oocytes (1.64% versus 1.11%; P<0.05). These results indicate that VSEGP can support the morphology of vitrified preantral follicles and oocytes.