Study on the significance and control mechanism of apoptosis in follicle atresia system

为探讨细胞凋亡在卵泡闭锁系统中的意义及其调控机制，本课题研究了(1)细胞凋亡的关键酶--白介素1β转换酶(ICE)的存在；(2)ICE在体内和体外排卵系统中的变化；(3)体外ICE在大鼠卵巢及其培养体系中的调控作用。2)PMSG-hCG处理组，卵巢ICE基因表达水平在注射PMSG后无明显变化，但在注射hCG后6h，ICE基因表达显著增加，24小时达高峰(较治疗前增加152%)，48小时后恢复至治疗前水平。3)GnRH、雄激素和肿瘤坏死因子-α可刺激卵巢ICE基因表达(分别为对照组的140%、160%和200%)。结论：(1)ICE是Fas-Fas配体系统中细胞凋亡的关键酶，(2)ICE与排卵系统密切相关；(3)促性腺激素释放激素、雄激素和肿瘤坏死因子-α被认为是卵泡闭锁细胞凋亡的刺激因子，可刺激卵巢ICE的表达。提示ICE系统中的细胞凋亡过程在卵泡闭锁系统中具有重要作用。

In the present project, to study on the significance and control mechanism of apoptosis in follicle atresia system, I investigated (1) the existence of interleukin-1 beta converting enzyme (ICE), which is a key enzyme of apoptosis, (2) the changes of ICE in ovulation system in vivo and in vitro, (3) the control factor of ICE in vitro, using measurement of ICE mRNA in rats ovaries and its culture system.1) ICE mRNA was detected in rat ovaries. Its amount in ovary was 10% of that in spleen.2) In PMSG-hCG treatment, ICE mRNA in ovary was not changed in PMSG injection, but its appearance increased immedately 6 hours after hCG injection, reached to the peak 24 hours after (152% increase of pre-treatment), and retured to pre-treatment level 48 hours after.3) GnRH, androgen and TNF-alph atimulated ICE mRNA expression in ovary (140%, 160% and 200% of control, respectiveky). However, dexamethasone inhibited ICE mRNA expression (60% of control).In conclusion, I demonstrated that (1) ICE, which is a key enzyme of appearane of apoptosis in Fas-Fas ligand system, exists in ovary, (2) ICE is deeply concerned with ovulation system, (3) GnRH, androgen and TNF-alph, which are reported as stimulating factors of apoptosis in follicle atresia, stimulate ICE expression in ovary. These data indicate that apoptosis process via ICE system has important roles in follicle atresia system.