The cross-talk between oocyte and somatic cells plays a crucial role in the regulation of follicular development and oocyte maturation. As a result, granulosa cell apoptosis causes follicular atresia. In this study, sheep granulosa cells were cultured under thermal stress to induce apoptosis, and melatonin (MT) was examined to evaluate its potential effects on heat-induced granulosa cell injury. The results demonstrated that the Colony Forming Efficiency (CFE) of granulosa cells was significantly decreased (heat 19.70% ± 1.29% vs. control 26.96% ± 1.81%, p < 0.05) and the apoptosis rate was significantly increased (heat 56.16% ± 13.95%vs. control 22.80% ± 12.16%, p < 0.05) in granulosa cells with thermal stress compared with the control group. Melatonin (10−7 M) remarkably reduced the negative effects caused by thermal stress in the granulosa cells. This reduction was indicated by the improved CFE and decreased apoptotic rate of these cells. The beneficial effects of melatonin on thermal stressed granulosa cells were not inhibited by its membrane receptor antagonist luzindole. A mechanistic exploration indicated that melatonin (10−7 M) down-regulated p53 and up-regulated Bcl-2 and LHR gene expression of granulosa cells under thermal stress. This study provides evidence for the molecular mechanisms of the protective effects of melatonin on granulosa cells during thermal stress.

The relationship between sperm DNA fragmentation and in vitro fertilization (IVF) outcome was uncertain today. In the past, researchers studying the pregnancy outcome of IVF, mainly base on fresh embryo transplantation cycle, recently, cumulative live birth rate was consider as a new indicator of IVF successful rate which is used to evaluate the pregnancy outcome by fresh or thawed transferred embryos until live birth or use up all embryos in one oocyte collection cycle, is more comprehensive. The purpose of this research is to investigate the relationship between sperm DNA fragmentation and cumulative live birth rate. 1019 couples who were assisted by IVF in our center from Jan 2012 to Dec 2016 were studied according to inclusive criteria, and divided into four groups by DNA fragmentation index (DFI), which were determined by sperm chrome structure assay (SCSA), then the fertilization rate, No. of Embryo available and cumulative live birth rate between the groups were analyzed. Cumulative live birth curve was plotted to study the time to reach live birth, and Cox regression model was used in order to find out the factors affecting pregnancy outcome. Study results showed no significant difference in cumulative live birth rate between the four groups, but DFI ≥40% group were significantly lower than the other three groups. In the cumulative live birth curve figure, except the high DFI group, the curve of the other three groups is relatively close. Cox regression model suggest that DFI was not the main factor affecting pregnancy outcome. Further studies in these patients with oligozoospermia showed that when DFI increase, a decrease trend was appeared in cumulative live birth rate, and spend more time to reach live birth studied by the live birth curve. Cox model showed that DFI was the impact factor of pregnancy outcome in oligozoospermia patients. In conclusion, abnormal sperm DNA fragmentation have a negative impact on cumulative live birth rate in patients with oligozoospermia, but further research was still needed.