Carambula Silvia F, Pru James K, Lynch Maureen P, Matikainen Tiina, Gonçalves Paulo Bayard D, Flavell Richard A, Tilly Jonathan L, Rueda Bo R
Vincent Center for Reproductive Biology, Department of Obstetrics and Gynecology, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts 02114, USA.
Reprod Biol Endocrinol. 2003 Feb 11;1:15. doi: 10.1186/1477-7827-1-15.
We recently demonstrated that caspase-3 is important for apoptosis during spontaneous involution of the corpus luteum (CL). These studies tested if prostaglandin F2alpha (PGF2alpha) or FAS regulated luteal regression, utilize a caspase-3 dependent pathway to execute luteal cell apoptosis, and if the two receptors work via independent or potentially shared intracellular signaling components/pathways to activate caspase-3. Wild-type (WT) or caspase-3 deficient female mice, 25-26 days old, were given 10 IU equine chorionic gonadotropin (eCG) intraperitoneally (IP) followed by 10 IU human chorionic gonadotropin (hCG) IP 46 h later to synchronize ovulation. The animals were then injected with IgG (2 micrograms, i.v.), the FAS-activating antibody Jo2 (2 micrograms, i.v.), or PGF2alpha (10 micrograms, i.p.) at 24 or 48 h post-ovulation. Ovaries from each group were collected 8 h later for assessment of active caspase-3 enzyme and apoptosis (measured by the TUNEL assay) in the CL. Regardless of genotype or treatment, CL in ovaries collected from mice injected 24 h after ovulation showed no evidence of active caspase-3 or apoptosis. However, PGF2alpha or Jo2 at 48 h post-ovulation and collected 8 h later induced caspase-3 activation in 13.2 +/- 1.8% and 13.7 +/- 2.2 % of the cells, respectively and resulted in 16.35 +/- 0.7% (PGF2alpha) and 14.3 PlusMinus; 2.5% TUNEL-positive cells when compared to 1.48 +/- 0.8% of cells CL in IgG treated controls. In contrast, CL in ovaries collected from caspase-3 deficient mice whether treated with PGF2alpha, Jo2, or control IgG at 48 h post-ovulation showed little evidence of active caspase-3 or apoptosis. CL of WT mice treated with Jo2 at 48 h post-ovulation had an 8-fold increase in the activity of caspase-8, an activator of caspase-3 that is coupled to the FAS death receptor. Somewhat unexpectedly, however, treatment of WT mice with PGF2alpha at 48 h post-ovulation resulted in a 22-fold increase in caspase-8 activity in the CL, despite the fact that the receptor for PGF2alpha has not been shown to be directly coupled to caspase-8 recruitment and activation. We hypothesize that PGF2alpha initiates luteolysis in vivo, at least in part, by increasing the bioactivity or bioavailability of cytokines, such as FasL and that multiple endocrine factors work in concert to activate caspase-3-driven apoptosis during luteolysis.
我们最近证明，半胱天冬酶 - 3在黄体（CL）自然退化过程中的细胞凋亡中起重要作用。这些研究测试了前列腺素F2α（PGF2α）或FAS是否调节黄体退化，是否利用半胱天冬酶 - 3依赖性途径执行黄体细胞凋亡，以及这两种受体是否通过独立或潜在共享的细胞内信号成分/途径来激活半胱天冬酶 - 3。给25 - 26日龄的野生型（WT）或半胱天冬酶 - 3缺陷型雌性小鼠腹腔内（IP）注射10 IU马绒毛膜促性腺激素（eCG），46小时后腹腔内注射10 IU人绒毛膜促性腺激素（hCG）以同步排卵。然后在排卵后24或48小时给动物静脉注射IgG（2微克）、FAS激活抗体Jo2（2微克）或腹腔注射PGF2α（10微克）。8小时后收集每组动物的卵巢，用于评估CL中活性半胱天冬酶 - 酶和细胞凋亡（通过TUNEL测定法测量）。无论基因型或处理如何，在排卵后24小时注射的小鼠卵巢中的CL均未显示活性半胱天冬酶 - 3或细胞凋亡的迹象。然而，排卵后48小时注射PGF2α或Jo2并在8小时后收集的卵巢中，分别有13.2±1.8%和13.7±2.2%的细胞诱导了半胱天冬酶 - 3激活，与IgG处理对照组中CL的1.48±0.8%的细胞相比，分别导致16.35±0.7%（PGF2α）和14.3±2.5%的TUNEL阳性细胞。相比之下，从半胱天冬酶 - 3缺陷型小鼠卵巢中收集的CL，无论在排卵后48小时用PGF2α、Jo2还是对照IgG处理，均几乎没有活性半胱天冬酶 - 3或细胞凋亡的迹象。排卵后48小时用Jo2处理的WT小鼠的CL中，半胱天冬酶 - 8（与FAS死亡受体偶联的半胱天冬酶 - 3激活剂）的活性增加了8倍。然而，有点出乎意料的是，排卵后48小时用PGF2α处理WT小鼠，尽管尚未证明PGF2α受体直接与半胱天冬酶 - 8的募集和激活偶联，但CL中的半胱天冬酶 - 8活性增加了22倍。我们假设PGF2α至少部分地通过增加细胞因子（如FasL）的生物活性或生物利用度来启动体内黄体溶解，并且多种内分泌因子协同作用以在黄体溶解过程中激活半胱天冬酶 - 3驱动的细胞凋亡。
