Yun Feng

Shanghai Jiao Tong University, Shanghai, Shanghai Shi, China

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Publications (7)17.18 Total impact

  • Article: Dynamic changes of histone H3 trimethylated at positions K4 and K27 in human oocytes and preimplantation embryos.
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    ABSTRACT: To investigate the distribution patterns of H3K4me3 and H3K27me3 in human oocytes and preimplantation embryos. Experimental study. University reproductive medical center. Patients undergoing IVF cycles. Oocytes and embryos were collected from patients undergoing IVF cycles. The distribution patterns of H3K4me3 and H3K27me3 in oocytes and embryos were analyzed by indirect immunofluorescent staining and scanning confocal microscopy. H3K4me3 and H3K27me3 signals were detectable at each stage of oocyte and embryonic development. However, only one of the pronuclei showed signal for H3K27me3 in each of the zygotes, whereas H3K4me3 staining was always uniform in all zygotes. The level of H3K4me3 decreased steadily from germinal vesicle to metaphase II stage, obviously increased from zygote stage to four-cell stage, and reached the lowest at eight-cell stage. A sharp increase was then observed at blastocyst stage. The level of H3K27me3 slightly changed from germinal vesicle stage to zygote stage, then decreased steadily and reached the lowest at eight-cell stage, followed by a significant increase at blastocyst stage. The levels of H3K4me3 and H3K27me3 show dynamic changes during human oocyte maturation and preimplantation embryonic development. Asymmetric distribution of H3K27me3 exists in human zygote pronuclei, whereas H3K4me3 is always uniform in all of the pronuclei.
    Fertility and sterility 07/2012; 98(4):1009-16. · 3.97 Impact Factor
  • Article: Pinopodes, leukemia inhibitory factor, integrin-β3, and mucin-1 expression in the peri-implantation endometrium of women with unexplained recurrent pregnancy loss.
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    ABSTRACT: To compare pinopode morphology and coverage, and expression of leukemia inhibitory factor (LIF), integrin-β3, and mucin-1 (MUC1) in the peri-implantation endometrium of women with unexplained recurrent pregnancy loss (RPL) versus normal fertile women. Exploratory clinical study. University-affiliated assisted reproductive center. Women undergoing assisted reproduction at centers of reproductive medicine in two university teaching hospitals. Endometrial biopsy samples were obtained from women with RPL (test group, n = 30) and normal fertile women (control group, n = 26) 7 days after the day of luteinizing hormone peak. Pinopode morphology and coverage were assessed by use of scanning electron microscopy. Expression of LIF, integrin β3, and MUC1 were evaluated by immunohistochemical staining. Pinopode morphology and coverage, and the expression of LIF, integrin-β3, and MUC1 in both groups. Pinopode morphology and coverage, and the expression of LIF and integrin-β3 showed no statistically significant differences between the two groups. The expression of MUC1 was statistically significantly reduced in the glandular epithelial cells and endometrial lumen of the RPL group compared with controls. The morphology and the coverage of pinopodes and expression of LIF and integrin-β3 did not change, but MUC1 expression was statistically significantly reduced in women with RPL compared with normal women.
    Fertility and sterility 06/2012; 98(2):389-95. · 3.97 Impact Factor
  • Article: Sirt1 exerts anti-inflammatory effects and promotes steroidogenesis in Leydig cells.
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    ABSTRACT: To investigate the anti-inflammatory effects of Sirt1 and its roles in steroidogenesis in Leydig cells. In vitro cell culture study. Reproductive medical center. C57BL/6 male mice. TM3 Leydig cells were treated with proinflammatory cytokines including tumor necrosis factor-α, interleukin-6, or interleukin-1β. Sirt1 mRNA and protein levels were measured by real-time polymerase chain reaction and Western blotting in TM3 Leydig cells treated with proinflammatory cytokines. The cell viability was determined using MTT and BrdU incorporation assays. The effect of Sirt1 on the coactivation of steroidogenic factor 1 (SF-1) was characterized by coimmunoprecipitation and luciferase reporter assays. Sirt1 mRNA and protein levels were significantly down-regulated by proinflammatory cytokines treatment in TM3 Leydig cells. Sirt1 agonist or overexpression could efficiently protect cytotoxicity induced by proinflammatory cytokines. Sirt1 promoted steroidogenesis through its coactivation of SF-1. Sirt1 plays protective roles and promotes steroidogenesis in Leydig cells through its anti-inflammatory actions and coactivation of SF-1.
    Fertility and sterility 05/2012; 98(1):194-9. · 3.97 Impact Factor
  • Article: Frozen-thawed embryo transfer cycles in China: clinical outcomes of two and three multicellular embryos transfers.
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    ABSTRACT: To analyze the clinical outcomes of frozen embryo transfer (FET) cycles when two or three multicellular embryos were transferred in Chinese women. A retrospective study was conducted to analyze 980 FET cycles performed between January 2007 and October 2010. Two (785 cycles) or three (195 cycles) multicellular embryos were transferred. Both in patients under 35 years (n = 776) and those aged 35 to 39 years (n = 169), the transfer of two versus three multicellular embryos results in similar clinical pregnancy rates (CPR), implantation rates (IR) and live birth rates (LBR). In both age groups, the multiple pregnancy rate (MPR) was significantly higher in the three-embryo groups. Among women over 40 years of age (n = 35), there were no differences in the CPR, IR, MBR or LBR between the two groups Transferring two instead of three multicellular embryos in patients under 40 years old significantly decreases the risk of MPR without compromising PR, IR and LBR. In the age group above 40, transferring two instead of three multicellular embryos did not decrease PR, IR, MBR or LBR. Transferring more embryos when a patient had more unsuccessful cycles was not warranted in all patients.
    Journal of Assisted Reproduction and Genetics 03/2012; 29(5):417-21. · 1.84 Impact Factor
  • Article: The effect of human cumulus cells on the maturation and developmental potential of immature oocytes in ICSI cycles.
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    ABSTRACT: To investigate the effect of human cumulus cells on the maturation and developmental potential of immature oocytes in ICSI cycles. Immature oocytes were randomly divided into two groups: the cumulus-denuded oocyte group (group A) and the cumulus-intact oocyte group (group B). Only oocytes that reached metaphase II (MII) stage after in vitro maturation were used in the ICSI procedure. In vivo mature sibling MII oocytes served as the control group. Maturation rate, fertilization rate, embryo quality and developmental potential were examined. There was no significant difference in maturation rate between group A (68.16%) and group B (70.49%; P > 0.05). The total fertilization rate among the three groups was comparable (P > 0.05), while the zygotes with two pronuclei in group A (74.59%) or group B (75.97%) were significantly lower than those in control group (84.29%; P < 0.05). The available embryo rate in group A (11.49%) was markedly lower than that in group B (27.66%; P < 0.05), and both of them were significantly lower than that in control group (62.38%; P < 0.05). The proportion of ≥6-cell embryos in group B (45.74%) was notably higher than in group A (26.44%; P < 0.05), and both were markedly lower than in control group (65.92%; P < 0.05). The proportion of embryos with <10% fragmentation in group A (13.79%) was significantly lower than in group B (29.79%; P < 0.05), and both were notably lower than in control group (42.98%; P < 0.05). The presence of cumulus cells surrounding the immature oocytes during IVM before ICSI had no influence on nuclear maturation and fertilization, but leads to better subsequent embryonic development. This is perhaps mediated by an improvement in cytoplasmic maturation.
    Journal of Assisted Reproduction and Genetics 02/2012; 29(4):313-9. · 1.84 Impact Factor
  • Article: Progesterone levels on oocyte retrieval day can predict the quantity of viable embryos but not pregnancy outcome of intracytoplasmic sperm injection.
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    ABSTRACT: The present study aimed to determine whether serum progesterone (P) concentration on the day of oocyte retrieval (OR) affects the quantity of viable embryos and impacts the outcome of intracytoplasmic sperm injection (ICSI). A total of 289 women who underwent ICSI cycles after controlled ovarian hyperstimulation were divided in two groups based on P level (<11.7 and > or = 11.7 ng/ml) on OR day. Subjects did not differ significantly with respect to age, basal follicle-stimulating hormone levels, body mass index, or estradiol levels on day of administration of human chorionic gonadotropin or OR day. Women with ICSI cycles that had high P levels tended to have more retrieved oocytes, zygotes and embryos than women with lower levels, but the differences did not approach significance. However, the former group with higher P levels did have a significantly greater number of viable embryos (p = 0.003). Finally, the two groups did not show differences in pregnancy outcome in a new ICSI cycle. The study suggests that serum P levels on OR day are related to the quality of viable embryos but not to pregnancy outcome in fresh ICSI cycles.
    Gynecological Endocrinology 08/2008; 24(8):452-8. · 1.58 Impact Factor
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    Article: Estrogen level monitoring in artificial frozen-thawed embryo transfer cycles using step-up regime without pituitary suppression: is it necessary?
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    ABSTRACT: To discuss the meaning of serum oestradiol monitoring in frozen embryo transfer cycle using hormone replacement without pretreatment with gonadotropin hormone (GnRH) agonist. The data from two hundred twelve women undergoing two hundred seventy-four frozen-thawed embryo transfer (FET) cycles was included in this retrospective cohort study. They were detected of serum oestradiol levels and endometrium thicknesses during hormone supplement FET cycles and compared their pregnancy outcomes according to their oestradiol level on progesterone initiation day. Patients with different levels of serum oestradiol (percentile 0-25th, 25th-75th and 75th-100th) on progesterone initiation day yielded the endometrium thickness of 9.3 +/- 0.12, 8.9 +/- 0.07 and 9.1 +/- 0.11 mm(P > 0.05) and the pregnancy rate of 32.2%, 38.4% and 36.3% (P > 0.05) respectively. The serum estradiol level did not predict pregnancy success in hormone replacement FET cycles, suggesting that oestradiol monitoring in this method of endometrial preparation is unnecessary.
    Journal of Experimental & Clinical Assisted Reproduction 01/2008; 5:4.