Effects of activation with a Ca ionophore and roscovitine on the development of human oocytes that failed to fertilize after ICSI.

OBJECTIVE: The effects of oocyte activation with a Ca ionophore and roscovitine (Ca+R), a selective inhibitor of M-phase promoting factor, on unfertilized oocytes after intracytoplasmic sperm injection (ICSI) or testicular sperm extraction (TESE)-ICSI were evaluated. METHOD: Oocytes without pronuclei at 18 hours after ICSI were judged to be unfertilized and were exposed to the Ca ionophore A23187 (5 ?M) with or without roscovitine (50 ?M). The activation rate was measured 3, 7, and 18 hours later. Oocytes with two polar bodies and two pronuclei with a sperm tail were judged to have been activated. RESULTS: At 18 hours, the activation rates in the control, Ca ionophore, and Ca+R groups were 3.5% (4/112), 26.9% (7/26), and 32.1% (17/53), respectively. The activation rate of the Ca+R group was significantly higher than that of the control and similar to that of the Ca ionophore group. Among the oocytes that remained unfertilized after TESE-ICSI, the activation rates of the Ca ionophore and Ca+R groups were 22.2% (2/9) and 43.8% (7/16), respectively. CONCLUSIONS: Sequential treatment with an Ca ionophore and roscovitine activates oocytes that remain unfertilized after ICSI. In TESE-ICSI, the activation rate tended to be increased by the co-administration of roscovitine with a Ca ionophore. J. Med. Invest. 70 : 321-324, August, 2023.

Biotin levels in blood and follicular fluid and their associations with pregnancy outcomes in IVF/ICSI patients.

It has been shown that biotin, a water-soluble vitamin (B7), plays roles in reproductive functions, such as oocyte maturation and embryo development, in experimental animals. On the other hand, little is known about the clinical effects of biotin on human reproduction. In this study, serum and follicular fluid biotin levels were measured in patients who underwent in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI), and their associations with reproductive outcomes were evaluated. As a result, biotin was detected in follicular fluid, as well as serum, and the biotin levels of follicular fluid were found to be positively correlated with those of serum. The biotin levels of serum were higher than those of follicular fluid, suggesting that biotin may be taken up into the follicular fluid from the blood. Although serum and follicular fluid biotin levels tended to be higher in pregnant patients than in non-pregnant patients, these data did not show the significant statistical difference. These findings indicate that biotin does not contribute to the maintenance of oocyte quality, and hence, it does not increase fertilization and pregnancy rates. J. Med. Invest. 69 : 65-69, February, 2022.

A novel PCOS rat model and an evaluation of its reproductive, metabolic, and behavioral phenotypes.

BACKGROUND: Although animal models of PCOS have been used in many studies, none of them can reproduce both the reproductive and metabolic phenotypes of PCOS. In addition, behavioral parameters have not been evaluated in PCOS animal models. PURPOSE: We tried to produce an improved rat model of PCOS, and the reproductive, metabolic, and behavioral phenotypes of the model rats were evaluated. METHODS: Female rats were implanted with silicon tubes containing oil-dissolved dihydrotestosterone (Oil-DHT) as a new PCOS model. Their phenotypes were compared with those of conventional PCOS model rats (DHT), into which tubes containing crystalline DHT were implanted, and non-DHT-treated rats (control). RESULTS: Both the Oil-DHT and DHT rats showed greater body weight gain, food intake, and fat depot weight than the control rats. Furthermore, these groups showed fewer estrous stages and increased numbers of cystic follicles. The DHT rats exhibited lower ovarian and uterine weights than the control rats, whereas no such changes were observed in the Oil-DHT rats. The Oil-DHT and DHT rats showed less locomotor activity in the light phase than the control rats. CONCLUSIONS: Our proposed PCOS model reproduced both the reproductive and metabolic phenotypes of PCOS and may have potential for PCOS research.

Expression of cytokine-induced neutrophil chemoattractant suppresses tumor necrosis factor alpha expression and thereby prevents the follicles from undergoing atresia and apoptosis.

Aim: Cytokine-induced neutrophil chemoattractant (CINC/gro) is a CXC family chemokine, similar to interleukin-8 in rats, and is one of the factors that regulates ovulation. However, the mechanism that regulates atresia of the ovaries postovulation is not clearly defined. Methods: Whether antibody-blocking of CINC/gro can alter the number of ovulated oocytes and modulate neutrophil infiltration was investigated. The effect of the antibody on the level of inflammatory cytokine production and follicular atresia was examined. Apoptosis was measured by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method and via analysis of the messenger RNA expression of Bcl-2 and Bcl2-associated X (Bax). Results: The anti-CINC/gro antibody treatment decreased the number of ovulated oocytes. The messenger RNA levels of cyclooxygenase-2 and interleukin-1 beta were decreased by the antibody treatment, whereas that of tumor necrosis factor (TNF) alpha was increased. The TUNEL analysis revealed a larger number of apoptotic cells in the antibody group, compared with those in the control group, as well as a significant increase in the Bax/Bcl-2 ratio 24 hours after human chorionic gonadotropin administration. Conclusion: These findings suggest that ovulation is accelerated by neutrophil infiltration into the theca layer. The CINC/gro appears to synergize with interleukin-1 beta for ovulation. By contrast, the data suggest that CINC/gro expression suppresses TNF alpha expression and that CINC/gro expression therefore prevents the follicles from undergoing atresia and apoptosis.

Intra-follicular kisspeptin levels are related to oocyte maturation and gonadal hormones in patients who are undergoing assisted reproductive technology.

Purpose: To assess the kisspeptin concentrations in follicular fluid and their relationship with clinical outcomes during assisted reproductive technology. Methods: Thirty-nine patients who were aged 24-40 years and underwent oocyte retrieval for in vitro fertilization/intracytoplasmic sperm injection participated in this study. In 65 follicular fluid samples that had been obtained from 30 patients and their blood samples, the kisspeptin levels were measured in order to investigate the correlations with their gonadal hormone levels. Venous blood samples were collected from 14 patients to investigate their plasma kisspeptin levels across different phases of assisted reproductive technology. Results: The follicular fluid kisspeptin level was significantly higher than that of the plasma level and was positively associated with the follicular fluid estradiol concentration and with the serum estradiol and number of mature oocytes. In the plasma, the maximum concentration of kisspeptin was observed on the day of ovum pick-up and on the day of embryo transfer during ovarian stimulation for assisted reproductive technology. Conclusion: Kisspeptin was present in the follicular fluid and the plasma kisspeptin concentration was affected by ovarian stimulation. Kisspeptin appears to affect oocyte maturation and ovulation.

Development-related changes in the expression of the ovarian Kiss1 and Kiss1r genes and their sensitivity to human chorionic gonadotropin in prepubertal female rats.

Kisspeptin, which is encoded by the Kiss1 gene, and its receptor, the G protein-coupled receptor 54 (Kiss1r), play important roles in the regulation of reproductive functions in mammals. Several studies have shown that the Kiss1 and Kiss1r genes are expressed in the rat, primate, and human ovaries, and that the ovarian kisspeptin system plays a pivotal role in ovulation at the proestrous stage in adulthood. The purpose of this study was to evaluate development-related changes in the expression of ovarian Kiss1 and Kiss1r genes and in kisspeptin levels, and to identify the regulatory factors for these genes during the prepubertal period. The serum kisspeptin level was also measured to examine whether ovarian kisspeptin affects serum kisspeptin levels. Variations in the ovarian Kiss1 and Kiss1r mRNA levels were observed during the prepubertal period in female rats, with levels peaking around postnatal days 20 and 15, respectively. Nevertheless, the ovarian kisspeptin content per total protein level was stably maintained. Serum kisspeptin levels at postnatal days 30 and 35 were higher than those at earlier postnatal days. The pattern of the ovarian Kiss1 mRNA levels was similar to that of the serum luteinizing hormone (LH) levels, and the ovarian Kiss1 mRNA level increased after injection with human chorionic gonadotropin (HCG) on postnatal day 20, but not on postnatal days 10 and 30. These data indicate that ovarian Kiss1 and Kiss1r mRNA levels are increased on postnatal days 20 and 15, respectively, and that changes in the serum LH level and the ovarian sensitivity to LH may be involved in the alteration of ovarian Kiss1 mRNA levels.

Lysophosphatidic acid stimulates hyaluronan production by mouse cumulus-oocyte complexes.

Purpose: In mammals, cumulus expansion due to increased synthesis of hyaluronan was suggested to correlate with modification of the gap junction between cumulus cells and the oocyte, leading to cumulus expansion. We examined whether lysophosphatidic acid, a lipid mediator detected in mammalian body fluids, stimulates significant production of hyaluronan and thus affects mouse cumulus expansion in vitro. Methods: Cumulus-oocyte complexes isolated from the gonadotropin-treated ovaries of B6C3F1 mice were exposed to lysophosphatidic acid in the presence and absence of 0.3 % fetal bovine serum for measurement of cumulus expansion and released hyaluronan, respectively. Results: Exogenously added lysophosphatidic acid concentration-dependently stimulated production of hyaluronan in the cumulus cell-oocyte complex, and the stimulatory effect of lysophosphatidic acid on hyaluronan production was mediated through the signal pathways, including LPA receptor-Gi coupling, EGF receptor transactivation, and activations of phosphatidylinositol-specific phospholipase C, protein kinase C and mitogen-activated protein kinases. LPA increased mRNA expression of tumor necrosis α-induced protein 6, a hyaluronan-binding protein, and expansion of cumulus cell-oocyte complex. Conclusions: Lysophosphatidic acid in follicular fluids may participate in physiological cumulus expansion before ovulation by stimulating production of hyaluronan and proteins that enable the association of hyaluronan with cumulus cells and oocytes.

A bifunctional catalyst for carbon dioxide fixation: cooperative double activation of epoxides for the synthesis of cyclic carbonates.

We have developed a very active bifunctional porphyrin catalyst showing a high turnover number (TON = 103,000) for the synthesis of cyclic carbonates from CO(2) and epoxides under solvent-free conditions.

Roscovitine in combination with calcium ionophore induces oocyte activation through reduction of M-phase promoting factor activity in mice.

The aim of the present study was to determine oocyte activation and change in M-phase promoting factor (MPF) activity induced by treatment with calcium ionophore and roscovitine in comparison with those induced by treatment with roscovitine alone and treatment with calcium ionophore and puromycin in mice. Freshly ovulated oocytes obtained from 6-8-week-old mice were divided into five groups (no activation treatment; 5 µM calcium ionophore A23187; 50 µM roscovitine; 5 µM calcium ionophore and 10 µg/ml puromycin; and 5 µM calcium ionophore and 50 µM roscovitine) and were incubated for 6 h. Oocyte activation, assessed by morphological changes, and changes in MPF activity in the five groups at 0, 2, 4 and 6 h of incubation were examined. Activated oocytes were defined as oocytes with at least one pronucleus. Oocytes treated with roscovitine alone were not activated during the 6-h incubation period. All of the oocytes in the calcium ionophore with puromycin group and in the calcium ionophore with roscovitine group were activated. The percentage activity of MPF in oocytes treated with roscovitine alone was decreased after 2 h and increased after 4 h of incubation. The percentage activity of MPF in oocytes treated with calcium ionophore and roscovitine was significantly decreased with suppression of MPF activity being maintained for 6 h, and this change was similar to that in oocytes treated with calcium ionophore and puromycin. Roscovitine with calcium ionophore is effective for induction of oocyte activation through suppression of MPF activity in mice.

Effect of semen characteristics on pregnancy rate following intrauterine insemination.

OBJECTIVE: To assess the effects of semen characteristics on the success of intrauterine insemination (IUI). DESIGN: A retrospective study. SETTINGS: The Department of Obstetrics and Gynecology, Tokushima University Hospital, Japan. PATIENTS: Between 2004 and 2008, 1,177 IUI cycles in 283 couples were studied. INTERVENTION: IUI cycles were preceded with ovarian stimulation. MAIN OUTCOME MEASURE: Clinical pregnancy. RESULT: A total of 82 clinical pregnancies were obtained (7.0% pregnancy rate per cycle, 28.9% per case). Their subsequent outcomes of pregnancies were 18 miscarriages (21.9%), 2 ectopic pregnancies (2.4%) and 60 live births (73.2%). Of the 82 clinical pregnancies, 2 were twin pregnancies (2.4%). There was no triple or higher order multiple pregnancies. At the end of the sixth cycle, 73 clinical pregnancies had been achieved (89.0%). After diagnostic laparoscopy, the pregnancy rate per cycle for patients ≤ 35 years age was 18%, which is significantly higher than that of patients >35 years of age. Pregnancies occurred up to the fifth cycle after laparoscopy. The pregnancy rate (PR) per cycle was significantly higher in cases of sperm movement rates more than 30% (PR 9.3%) and total motile sperm counts more than 10 × 10(6)/ml (PR 8.2%). A study comparing the washed and unwashed cases did not reveal any differences. CONCLUSION: In male sub-fertility cases of sperm parameters as motility rates ≥ 30% and motile sperm concentration ≥ 10 × 10(6)/ml, IUI could be a useful option for infertility treatment.

Negative collision energy dependence of Br formation in the OH + HBr reaction.

The reaction between HBr and OH leading to H(2)O and Br in its ground state is studied by means of a crossed molecular beam experiment for a collision energy varying from 0.05 to 0.26 eV, the initial OH being selected in the state |JOmega> = |3/2 3/2> by an electrostatic hexapole field. The reaction cross-section is found to decrease with increasing collision energy. This negative dependence suggests that there is no barrier on the potential energy surface for the formation pathway considered. The experimental results are compared with the previously reported quantum scattering calculations of Clary et al. (D. C. Clary, G. Nyman and R. Hernandez, J. Phys. Chem., 1994, 101, 3704), and briefly discussed in the light of skewed potential energy surfaces associated with heavy-light-heavy type reactions.