Trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, can significantly improve the reprogramming efficiency of somatic cells. However, whether TSA has a detrimental effect on other kinds of embryos is largely unknown because of the lack of integrated analysis of the TSA effect on natural fertilized embryos. To investigate the effect of TSA on mouse embryo development, we analyzed preimplantation and post-implantation development of in vivo, in vitro fertilized, and parthenogenetic embryos treated with TSA at different concentrations and durations. In vivo fertilized embryos appeared to be the most sensitive to TSA treatment among the three groups, and the blastocyst formation rate decreased sharply as TSA concentration and treatment time increased. TSA treatment also reduced the livebirth rate for in vivo fertilized embryos from 56.59 to 38.33% but did not significantly affect postnatal biological functions such as the pups’ reproductive performance and their ability for spatial learning and memory. Further analysis indicated that the acetylation level of H3K9 and H4K5 was enhanced by TSA treatment at low concentrations, while DNA methylation appeared to be also disturbed by TSA treatment only at high concentration. Thus, our data indicates that TSA has different effects on preimplantation embryonic development depending on the nature of the embryo’s reproductive origin, the TSA concentration and treatment time, whereas the effect of TSA at the indicated concentration on postnatal function was minor.
Cheng Peng, Zhuo Lv, Tang Hai, Xiangpeng Dai, and Qi Zhou
Hai-Yan Hou, Xi Wang, Qi Yu, Hong-Yi Li, Shao-Jie Li, Rui-Yi Tang, Zai-Xin Guo, Ya-Qiong Chen, Chun-Xiu Hu, Zhi-Juan Yang, Wen-ke Zhang, and Yan Qin
Decline in successful conception decreases more rapidly after 38 years of age owing to follicular depletion and decreased oocyte quality. However, limited information is available regarding the underlying mechanism and the useful treatment. This study aimed to evaluate the effects of growth hormone supplementation on oocyte maturation in vivo in aged and young mice and to determine its effect on mitochondrial function. The influence of three different doses of recombinant human growth hormone (rhGH) (0.4, 0.8 and 1.6 mg/kg/day) for 8 weeks before ovarian stimulation was analyzed. Superovulated oocytes were released from the oviduct of 12-week-old and 40-week-old female C57BL/6J mice 14–16 h after administration of human chorionic gonadotropin. Ovarian follicle and morphological analysis and oocyte maturation parameters were then evaluated. This study is the first, to our knowledge, to report that medium- and high-dose rhGH significantly increases antral follicles in aged mice but anti-Müllerian hormone (AMH) levels. Furthermore, derived oocytes, MII-stage oocyte rate, ATP levels, mitochondrial membrane potential and frequencies of homogeneous mitochondrial distribution increased. In contrast, in both aged and young mice, the mtDNA copy numbers per oocyte were similar before rhGH administration, and upon saline administration, they did not differ significantly. We conclude that medium-dose rhGH supplementation before standard ovarian stimulation regimens improves oocyte quality in aged mice, probably by enhancing mitochondrial functionality.