Propylparaben exposure impairs G2/M and metaphase-anaphase transition during mouse oocyte maturation
Zhen‐Nan Pan, Lili Zhuang, Hui-Shan Zhao, Shu‐Yuan Yin, Min Chu, Xiaoyan Liu, Hongchu Bao
Abstract
Propylparaben (PrPB) is a known endocrine disrupting chemicals that is widely applied as preservative in pharmaceuticals, food and cosmetics. PrPB has been detected in human urine samples and human serum and has been proven to cause functional decline in reproduction. However, the direct effects of PrPB on mammalian oocyte are still unknown. Here, we demonstrationed that exposure to PrPB disturbed mouse oocyte maturation in vitro, causing meiotic resumption arrest and first polar body extrusion failure. Our results indicated that 600 μM PrPB reduced the rate of oocyte germinal vesicle breakdown (GVBD). Further research revealed that PrPB caused mitochondrial dysfunction and oxidative stress, which led to oocyte DNA damage. This damage further disturbed the activity of the maturation promoting factor (MPF) complex Cyclin B1/ Cyclin-dependent kinase 1 (CDK1) and induced G2/M arrest. Subsequent experiments revealed that PrPB exposure can lead to spindle morphology disorder and chromosome misalignment due to unstable microtubules. In addition, PrPB adversely affected the attachment between microtubules and kinetochore, resulting in persistent activation of BUB3 amd BubR1, which are two spindle-assembly checkpoint (SAC) protein. Taken together, our studies indicated that PrPB damaged mouse oocyte maturation via disrupting MPF related G2/M transition and SAC depended metaphase-anaphase transition. • PrPB exposure deteriorated G2/M transition and polar body extrusion in oocytes. • PrPB exposure induced inactivation of Cyclin B1/CDK1 complex in oocytes. • PrPB exposure altered mitochondria function and ROS level in oocytes. • PrPB exposure disrupted tubulin acetylation for spindle formation in oocytes. • PrPB exposure continuously activated the spindle assembly checkpoint in oocytes.