Xiaoxi Sun

Direct rosiglitazone action on steroidogenesis and proinflammatory factor production in human granulosa-lutein cells

BackgroundOvarian granulosa cells are the predominant source of estradiol and progesterone biosynthesis in vivo. Rosiglitazone, a synthetic agonist of the peroxisome proliferator-activated receptor gamma (PPAR gamma), is applied as the treatment of insulin resistance including women with PCOS. The aim of the study was to investigate the direct effects of rosiglitazone on steroidogenesis and proinflammatory factor production in human granulosa-lutein cells (GLCs).MethodsPrimary human GLCs were separated during in vitro fertilization and cultured in the presence of rosiglitazone, GW9662 (an antagonist of PPAR gamma) and hCG. The mRNA expression of key steroidogenic factors including 3beta- hydroxysteriod dehydrogenase (3beta-HSD), cytochrome P-450 scc (CYP11A1), cytochrome P-450 aromatase (CYP19A1), and steroidogenic acute regulatory protein (StAR) were detected by quantitative real-time PCR. Estradiol and progesterone levels in GLCs cultures were measured by chemiluminescence immunoassay, and the proinflammtory factors (TNFalpha and IL-6) in conditioned culture media were measured by ELISA.ResultsPPAR gamma mRNA levels increased up to 3.24 fold by rosiglitazone at the concentration of 30 microM compared to control (P < 0.05). hCG alone or hCG with rosiglitazone had no significant effects on PPAR gamma mRNA levels. The CYP19A1 mRNA level at exposure to rosiglitazone alone showed a drop, but was not significantly reduced comparing to control. The expression levels of enzymes 3beta-HSD and CYP11A1 in all treatments did not alter significantly. The StAR mRNA expression at exposure to rosiglitazone was significantly increased comparing to control (P < 0.05). The media concentrations of E2 and progesterone by rosiglitazone treatment showed a declining trend comparing to control or cotreatment with hCG, which did not reach significance. Most importantly, treatment with rosiglitazone decreased TNFalpha secretion in a statistically significant manner compared with control (P < 0.05). The concentration of IL-6 following rosiglitazone exposure did not significantly decrease comparing to control.ConclusionIn cultured GLCs, rosiglitazone stimulated StAR expression, but did not significantly affect steroidogenic enzymes, as well as E2 and progesterone production. Moreover, rosiglitazone significantly decreased the production of TNFalpha in human GLCs, suggesting that PPAR gamma may play a role in the regulation of GLCs functions through inhibiting proinflammatory factors.

Effects of ovarian high response on implantation and pregnancy outcome during controlled ovarian hyperstimulation (with GnRH agonist and rFSH).

Background. The study was aimed at investigating the effects of ovarian high response during controlled ovarian hyperstimulation (COH) on implantation and pregnancy outcome in fresh IVF/ICSI cycles, and subsequent frozen‐thawed embryo transfer (FET) cycles. Methods. An analysis of 1,196 cycles using a long protocol with GnRHa and rFSH was performed. A serum oestrial level (peak E2) was obtained on the day of hCG administration, and patients were grouped by peak E2 percentile distribution into 3 groups. Normal responder was set as cut‐off concentrations between percentile (P)25 and P75 (Group A: 1,199–3,047 pg/ml, 595 cycles). Moderate high responders were classified as peak E2 between P75–P90 (Group B: 3,048–4,127 pg/ml, 180 cycles). For the high response group, the E2 cut‐off concentration was set as P90 and above (Group C: ≥4,128 pg/ml, 119 cycles). Oocyte/embryo parameters and clinical outcomes were compared among the 3 groups in fresh cycles and subsequent FET cycles. Results. Comparisons between groups revealed no difference in the quality of oocyte retrieved and in fertilisation rates. Group C showed decreased trends in implantation and pregnancy rates compared with Group A, but statistical significance was reached only for the difference in implantation rates. Implantation and pregnancy rates in FET cycles were similar among the 3 groups. Conclusions. High serum estrogen levels were detrimental to implantation, but not to the quality of oocytes, which may be due to an adverse effect on endometrial receptivity in COH cycles.

Progesterone receptor isoform B in the human fallopian tube and endometrium following mifepristone.

The distribution of progesterone receptor isoform B may have important clinical significance. The aim of this study was to compare the expression, localization and regulation of progesterone receptor isoform B in the human Fallopian tube and endometrium following mifepristone in a dose effective for contraception. Fertile women were treated with a single dose of 200 mg mifepristone on day luteinizing hormone (LH)+2. Biopsies were obtained from the Fallopian tube on day LH+4 to LH+6 and from the endometrium on day LH+6 to LH+8. Progesterone receptor isoform B expression was analyzed by immunohistochemistry and reverse transcriptase polymerase chain reaction. Treatment with mifepristone increased progesterone receptor isoform B concentration in epithelial and stromal cells in the Fallopian tube and also increased progesterone receptor isoform B concentration in the glandular cells of the endometrium. These results further support the hypothesis that the contraceptive effect of mifepristone when given postovulatory is primarily due to alteration of the peri-implantation milieu influencing endometrial receptivity.

Action of mifepristone on the expression of insulin-like growth factor binding protein-1 mRNA and protein during the early luteal phase in the human oviduct

OBJECTIVE To investigate the effects of the antiprogestin mifepristone on the expression of insulin-like growth factor binding protein-1 (IGFBP-1) mRNA and protein during the early luteal phase in the human oviduct. DESIGN Prospective case-control study. SETTING University hospital. PATIENT(S) Fourteen healthy women with regular menstrual cycles who were admitted to the hospital for voluntary sterilization by the laparoscopic technique. INTERVENTION(S) Treatment with 200 mg of mifepristone was administered on day LH+2. Fallopian tube samples were obtained on days LH+4 to LH+6. MAIN OUTCOME MEASURE(S) Expression of IGFBP-1 was identified using immunhistochemistry, and mRNA levels were determined with semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR). RESULT(S) Immunoreactivity for IGFBP-1 was primarily localized to the cytoplasm of the oviductal epithelial cells. Messenger RNA for IGFBP-1 was identified in total RNA extracted from the same fallopian tube samples. There was a significant increase in the expression of IGFBP-1 immunostaining and mRNA after treatment with mifepristone. CONCLUSION(S) These data further illustrate the complex actions of mifepristone and support the view that changes in the oviductal environment after treatment with mifepristone may be detrimental to normal gamete transport and function and contribute to the contraceptive action of mifepristone.

Endometrial Mucin-1 and Pinopode in Peri-implantation Phase in Ovarian High Responders during Controlled Ovarian Hyperstimulation Cycles

Objective To investigate effects of ovarian high response on endometrial mucin-1 (MUC1) and pinopode in peri-implantation phase in controlled ovarian hyperstimulation (COH) cycles. Methods Ovarian high response was defined as serum E 2 > 15 000 pmol/L on the day of hCG administration in COH cycle using GnRH agonist and recombinant FSH (n=8). Healthy and fertile women were used as the natural control (n=10). Endometrial biopsies were performed on the day of LH+7/hCG+7. Pinopode formation was observed by scanning electron microscope. Expression of MUC1 was detected with quantitative Real-time PCR and immunohistochemistry. Results In high response group, the lumen surface was covered with variant pinopodes and microvillous. The expression of MUC1 mRNA in high response group was lower than that in the natural control (P Conclusion Asynchronized pinopode appearance and lower expression of MUC1 during peri-implantation period were the characteristics of endometrium in high response group, which may provide a clue of decreased endometrial receptivity in the supraphysiological hormone milieu.