Fixation in Form-Acetic allows hyaluronic acid detection in mouse ovaries

Lay summary To visualise tissues to determine the presence of disease or simply to understand anatomy, it is important to preserve fresh tissue. Fixatives are chemical solutions that preserve tissues to enable microscopic evaluation. However, some fixatives introduce artefact such as shrinkage of cells. Recently, a new fixative, Form-Acetic, was developed that is superior for preserving the structure of ovary tissue and allows investigation of ovary composition. One component of the ovary is hyaluronic acid (HA), which plays a crucial role in normal ovary function and fertility. Importantly, HA is sensitive to different fixative solutions. Therefore, it is meaningful to verify whether Form-Acetic is suitable for detecting HA. In this study, adult mouse ovaries were fixed in Form-Acetic and HA was detected. All HA-containing structures in the ovary were clearly distinguished which proves that the novel fixative allows the detection of HA.

Loss of ASPM Disrupts Female Folliculogenesis in Mice

Background: The abnormal spindle-like, microcephaly-associated (ASPM) gene is a causative gene of autosomal recessive primary microcephaly (MCPH) 5 in humans, which is characterized by a reduction in brain volume. It was previously reported that truncated ASPM proteins in transgenic mice caused major defects in the germline, a severe reduction in ovary weight and the number of follicles accompanied by reduced fertility. However; it remains unknown whether a loss of ASPM induces abnormal ovarian function, resulting in female infertility. Methods: In order to assess the ovary function, we examined vaginal smear cytology from the age of 7 weeks to 100 weeks in CAG-mediated Cre-loxP conditional Aspm-/- knockout mice and control female mice. In addition, we evaluated the ovarian size, fibrosis ratio and the number of follicles (primordial, primary, secondary, antral and atretic follicles) in mice from 15 weeks to 100 weeks old by image analyses. Mann-Whitney U-test was used for statistical analysis. Results: The size of the ovary was significantly reduced in Aspm knockout mice at 15-20 weeks, 40-50 weeks and 70-80 weeks old. compared with the control mice. Furthermore, at all stages, we found a severe decrease in the number of developing follicles at 10-15 weeks, 40-50 weeks and 70-80 weeks old, accompanied by disrupted cyclic changes of vaginal cytology. Conclusion: The results showing that folliculogenesis was significantly decreased and associated with abnormal vaginal cytology in Aspm knockout female ovaries suggested that ASPM might play an important role in the folliculogenesis and estrous cyclicity of the postnatal ovary.

Melatonin supplementation and outcomes after assisted reproductive technology: A systematic review and meta-analyses

To assess the effect of melatonin (MT) supplementation on the outcomes of ART. A meta-analysis and systematic review was conducted. Eleven studies were included in this meta-analysis. Clinical pregnancy rate (CPR), live birth rate (LBR), Miscarriage rate (MR), fertilization rate (FR), Number of oocyte, MII oocyte, top-quality embryo were reported in 10, 3, 6, 7, 9, 8, and 6 studies, respectively. MT supplementation significantly increased the CPR, the No. of MII oocyte, the No. of top-quality embryo, and the FR. However, there was no significant difference in LBR, No. of oocyte, and the MR. When studies were sub-grouped by the interventions, no matter the control group is MI+FA or placebo/none, MT supplementation increased No. of MII oocyte and No. of top embryo, whereas showed similar CPR. When studies were sub-grouped according to women’s characteristic, MT supplementation showed no significant benefit on CPR in women with PCOS, with normal ovary function, and with previous low fertilization or poor-quality embryo. However, MT supplementation increased the No of MII in women with PCOS, but did not show benefit in women with normal ovary function. MT supplementation may not improve the CPR and LBR of ART. But MT seems be beneficial to the quality of oocyte and embryo, especially for women with PCOS and DOR. Further well-designed studies are needed before the recommendation of its clinical use.

TMEM150B is dispensable for oocyte maturation and female fertility in mouse

Premature ovarian insufficiency (POI) refers to severe decline of ovary function in females which usually leads to infertility. It has been reported that the TMEM150B gene is mostly associated with age at natural menopause, early menopause and POI, but its role in female reproduction remains unknown. In this study, we found Tmem150b was highly expressed in mouse oocytes, but its deletion had no obvious effect on meiotic maturation of oocytes indicated by first polar body emission and spindle morphology. There were also no obvious differences in follicle development and corpus luteum formation between knockout and wild type mice. Finally, knockout of Tmem150b did not affect female fertility and sexual hormone levels. In summary, our results suggest that TMEM150B is not essential for female fertility in mice.

Microenvironmental changes induced by placenta-derived mesenchymal stem cells restore ovarian function in ovariectomized rats via activation of the PI3K-FOXO3 pathway

Background Translational studies have explored the therapeutic potential and feasibility of mesenchymal stem cells (MSCs) in several degenerative diseases; however, mechanistic studies of the function of these cells have been insufficient. As ovarian failure causes anovulation as well as ovarian steroid hormonal imbalances, the specific aims of this study were to analyze the therapeutic role of placenta-derived MSCs (PD-MSCs) in an ovarian failure ovariectomy (OVX) rat model and evaluate whether PD-MSC transplantation (Tx) improved folliculogenesis and oocyte maturation in the injured ovary through PI3K/Akt and FOXO signaling. Methods Blood and ovary tissue were collected and analyzed after various PD-MSC Tx treatments in an ovariectomized rat model. Changes in the expression of folliculogenesis- and ovary regeneration-related genes induced by PD-MSC treatments were analyzed by qRT-PCR, Western blotting, and histological analysis. Results The levels of hormones related to ovary function were significantly increased in the PD-MSC Tx groups compared with those in the nontransplantation group (NTx). The follicle numbers in the ovarian tissues were increased along with the increased expression of genes related to folliculogenesis in the PD-MSC Tx groups compared with the NTx groups. Furthermore, Tx PD-MSCs induced follicle maturation by increasing the phosphorylation of GSK3 beta and FOXO3 (p < 0.05) and shifting the balance of growth and apoptosis in oocytes. Conclusions Taken together, these results show that PD-MSC Tx can restore ovarian function and induce ovarian folliculogenesis via the PI3K/Akt and FOXO signaling pathway.