Pachymic acid protects oocyte by improving the ovarian microenvironment in polycystic ovary syndrome mice†.

Women with polycystic ovary syndrome (PCOS) are characterized by endocrine disorders accompanied by a decline in oocyte quality. In this study, we generated a PCOS mice model by hypodermic injection of dehydroepiandrosterone, and metformin was used as a positive control drug to study the effect of pachymic acid (PA) on endocrine and oocyte quality in PCOS mice. Compared with the model group, the mice treated with PA showed the following changes (slower weight gain, improved abnormal metabolism; increased development potential of GV oocytes, reduced number of abnormal MII oocytes, and damaged embryos; lower expression of ovarian-related genes in ovarian tissue and pro-inflammatory cytokines in adipose tissue). All these aspects show similar effects on metformin. Most notably, PA is superior to metformin in improving inflammation of adipose tissue and mitochondrial abnormalities. It is suggested that PA has the similar effect with metformin, which can improve the endocrine environment and oocyte quality of PCOS mice. These findings suggest that PA has the similar effect with metformin, which can improve the endocrine environment and oocyte quality of PCOS mice.

The effects of graphene quantum dots on the maturation of mouse oocytes and development of offspring.

Recently, graphene nanomaterials have attracted tremendous attention and have been utilized in various fields because of their excellent mechanical, thermal, chemical, optical properties, and good biocompatibility, especially in biomedical aspects. However, there is a concern that the unique characteristics of nanomaterials may have undesirable effects. Therefore, in this study, we sought to systematically investigate the effects of graphene quantum dots (GQDs) on the maturation of mouse oocytes and development of the offspring via in vitro and in vivo studies. In vitro, we found that the first polar body extrusion rate in the high dosage exposure groups (1.0-1.5 mg/ml) 2 decreased significantly and the failure of spindle migration and actin cap formation after GQDs exposure was observed. The underlying mechanisms might be associated with reactive oxygen species accumulation and DNA damage. Moreover, transmission electron microscope studies showed that GQDs may have been internalized into oocytes, tending to accumulate in the nucleus and severely affecting mitochondrial morphology, which included swollen and vacuolated mitochondria accompanied by cristae alteration with a lower amount of dense mitochondrial matrix. In vivo, when pregnant mice were exposed to GQDs at 8.5 days of gestation (GD, 8.5), we found that high dosage of GQD exposure (30 mg/kg) significantly affected mean fetal length; however, all the second generation of female mice grew up normal, attained sexual maturity, and gave birth to a healthy offspring after mating with a healthy male mouse. The results presented in this study are important for the future investigation of GQDs for the biomedical applications.

SKAP2 regulates Arp2/3 complex for actin-mediated asymmetric cytokinesis by interacting with WAVE2 in mouse oocytes.

SKAP2 (Src kinase-associated phosphoprotein 2), a substrate of Src family kinases, has been suggested to be involved in actin-mediated cellular processes. However, little is known about its role in mouse oocyte maturation. In this study, we thus investigated the expression, localization, and functions of SKAP2 during mouse oocyte asymmetric division. SKAP2 protein expression was detected at all developmental stages in mouse oocytes. Immunofluorescent staining showed that SKAP2 was mainly distributed at the cortex of the oocytes during maturation. Treatment with cytochalasin B in oocytes confirmed that SKAP2 was co-localized with actin. Depletion of SKAP2 by injection with specific short interfering RNA caused failure of spindle migration, polar body extrusion, and cytokinesis defects. Meanwhile, the staining of actin filaments at the oocyte membrane and in the cytoplasm was significantly reduced after these treatments. SKAP2 depletion also disrupted actin cap and cortical granule-free domain formation, and arrested a large proportion of oocytes at the telophase stage. Moreover, Arp2/3 complex and WAVE2 expression was decreased after the depletion of SKAP2 activity. Our results indicate that SKAP2 regulates the Arp2/3 complex and is essential for actin-mediated asymmetric cytokinesis by interacting with WAVE2 in mouse oocytes.