Human oocyte-derived sperm chemoattractant is a hydrophobic molecule associated with a carrier protein

Objective: To characterize the nature of the human oocyte-derived chemoattractant. Design: Laboratory in-vitro study. Setting: Academic research institute. Patients: Ten healthy sperm donors. Oocyte-conditioned media from women undergoing IVF treatment due to male factor infertility. Interventions: Sperm samples were processed by the migration–sedimentation technique. Oocyte-conditioned media were collected 2-3 h after oocyte stripping. Main Outcome Measure(s): Sperm chemotaxis was assayed in a µ-slide chamber according to the direction of swimming relative to that of the chemical gradient. Results: Oocyte-conditioned media treated with proteases did not lose their chemotactic activity; on the contrary, they became more active, with the activity shifted to lower concentrations. When oocyte-conditioned media were subjected to hexane extraction, chemotactic activity was found in both the hydrophobic and aqueous phases. Known mammalian sperm chemoattractants were ruled out as oocyte-derived chemoattractants. Conclusions: Our results suggest that the oocyte-derived chemoattractant is a hydrophobic non-peptide molecule which, in an oocyte-conditioned medium, is associated with a carrier protein that enables its presence in a hydrophilic environment

Gq-Induced Apoptosis is Mediated by AKT Inhibition That Leads to PKC-Induced JNK Activation

Background/Aims: Gq protein-coupled receptors (GqPCRs) regulate various cellular processes including mainly proliferation and differentiation. In a previous study, we found that in prostate cancer cells, the GqPCR of GnRH induces apoptosis by reducing the PKC-dependent AKT activity and elevating JNK phosphorylation. Since it was thought that GqPCR induces mainly activation of AKT, we undertook to examine how general is this phenomenon and understand its signaling. Methods: We used various cells to follow the phosphorylation of signaling components using western blotting. Results: In a screen of 21 cell lines, we found that PKC activation results in the reduction of AKT activity, which correlates nicely to JNK activation and in some cases to apoptosis. To further understand the signaling pathways involved in this stimulation, we studied in detail the SVOG-4O and αT3-1 cells. We found that PGF2α and GnRH agonist (GnRH-a) indeed induce significant Gq- and PKC- dependent apoptosis in these cells. This is mediated by two signaling branches downstream of PKC, which converge at the level of MLK3 upstream of JNK. One branch consists on c-Src activation of the JNK cascade and the second involves reduction of AKT activity that alleviates its inhibitory effect on MLK3, to allow the flow of the c-Src signal to JNK. At the MAPKK level, we found that the signal is transmitted by MKK7 and not MKK4. Conclusion: Our results present a general mechanism that mediates a GqPCR-induced, death receptors-independent, apoptosis in physiological, as well as cancer-related systems

Human oocyte-derived sperm chemoattractant is a hydrophobic molecule associated with a carrier protein

Objective: To characterize the nature of the human oocyte-derived chemoattractant. Design: Laboratory in vitro study. Setting: Academic research institute. Patient(s): Ten healthy sperm donors. Oocyte-conditioned media from women undergoing IVF treatment because of male factor infertility. Intervention(s): Sperm samples were processed by the migration-sedimentation technique. Oocyte-conditioned media were collected 2-3 hours after oocyte stripping. Main Outcome Measure(s): Sperm chemotaxis was assayed in a m-slide chamber according to the direction of swimming relative to that of the chemical gradient. Result(s): Oocyte-conditioned media treated with proteases did not lose their chemotactic activity; on the contrary, they became more active, with the activity shifted to lower concentrations. When oocyte-conditioned media were subjected to hexane extraction, chemotactic activity was found in both the hydrophobic and aqueous phases. Known mammalian sperm chemoattractants were ruled out as oocyte-derived chemoattractants. Conclusion(s): Our results suggest that the oocyte-derived chemoattractant is a hydrophobic nonpeptide molecule that, in an oocyte-conditioned medium, is associated with a carrier protein that enables its presence in a hydrophilic environment. (Fertil Steril Ò 2014;102: 885-90

Hysteroscopic removal of retained products of conception following first trimester medical abortion

Study Objective: To investigate the use of operative hysteroscopy instead of traditional curettage in women with retained products of conception (RPOC) following first trimester medical abortion, with the aim of reducing post-operative intrauterine adhesions. Design: Retrospective study. Setting: Gynecology department in a University affiliated hospital. Patients: All women treated by hysteroscopy for RPOC following first trimester medical abortion using the mifepristone-misoprostol protocol for pregnancy termination or the misoprostol protocol for early missed abortion from January 2013 to August 2016. Intervention: Operative hysteroscopy for removal of RPOC. Post-operative intrauterine adhesions were assessed by diagnostic office hysteroscopy after 6â8 weeks. Measurements and Main Results: 50 cases were identified. The mean time from medication administration to the operative hysteroscopy was 1.7 ± 0.7 months. Operative hysteroscopy with blunt use of the resectoscopic loop was used to remove all specimens, and all procedures were completed without intra-operative complications. Two patients (4.0%) were readmitted for fever. Pathology confirmed the presence of RPOC in 45 (90.0%) cases. On follow-up office hysteroscopy, a normal uterine cavity without evidence of intrauterine adhesions was seen in 29/29 (100%) women. Conclusion: Hysteroscopy for removal of RPOC following medical abortion is associated with low rates of complications and post-operative intrauterine adhesions. Keywords: abortion, hysteroscopy, intrauterine adhesions, retained products of conceptio

The Role of PEDF in Reproductive Aging of the Ovary

Reproductive aging is characterized by a decline in ovarian function and in oocytes’ quantity and quality. Pigment epithelium-derived factor (PEDF), a pivotal player in ovarian angiogenic and oxidative balance, was evaluated for its involvement in reproductive aging. Our work examines the initial stage of reproductive aging in women and mice, and the involvement of PEDF in the process. Granulosa cells from reproductively-aged (RA) women and mice (36–44 years old and 9–10 months old, respectively) indicated an increase in the level of PEDF mRNA (qPCR), with yet unchanged levels of AMH and FSHR mRNAs. However, the PEDF protein level in individual women showed an intra-cellular decrease (ELISA), along with a decrease in the corresponding follicular fluid, which reflects the secreted fraction of the protein. The in vitro maturation (IVM) rate in the oocytes of RA mice was lower compared with the oocytes of young mice, demonstrated by a reduced polar body extrusion (PBE) rate. The supplementation of PEDF improved the hampered PBE rate, manifested by a higher number of energetically-competent oocytes (ATP concentration and mtDNA copy number of individual oocytes). Our findings propose PEDF as an early marker of reproductive aging, and a possible therapeutic in vitro agent that could enhance the number of good-quality oocytes in older IVF patients