Neonatal exposure to an immunological challenge (lipopolysaccharide, LPS) increases the activity of hypothalamo-pituitary–adrenal axis and sensitises the GNRH pulse generator to the inhibitory influence of stress in adult rats. We investigated the effects of neonatal exposure to LPS on various reproductive parameters during puberty and into adulthood in female rats. LPS (50 μg/kg, i.p.) or saline was administered on postnatal days 3 and 5. Vaginal opening was recorded, and oestrous cyclicity was monitored immediately post puberty and again at 8–9 weeks of age. At 10 weeks of age, the ovaries were removed and the number of follicles was counted, together with the thickness of the theca interna of the largest antral follicles. Ovarian sympathetic nerve activity was assessed immunohistochemically by measurement of the levels of ovarian low-affinity receptor of nerve growth factor (p75NGFR). In rats exposed to LPS in early life, there was a significant delay in puberty and disruption of oestrous cyclicity immediately post puberty, which persisted into adulthood. The follicle reserve was decreased, the thickness of the theca interna increased and the expression profile of ovarian p75NGFR increased in the neonatal LPS-treated animals. These data suggest that exposure to LPS during early neonatal life can have long-term dysfunctional effects on the female reproductive system, which might involve, at least in part, increased ovarian sympathetic nerve activity.
Xue-Qing Wu, Xiao-Feng Li, Bilu Ye, Neha Popat, Stuart R Milligan, Stafford L Lightman and Kevin T O'Byrne
Xue-Chao Tian, Qu-Yuan Wang, Dang-Dang Li, Shou-Tang Wang, Zhan-Qing Yang, Bin Guo and Zhan-Peng Yue
The aim of this study was to examine the expression and regulation of the crystallin, alpha B (Cryab) gene in mouse uterus during the peri-implantation period by in situ hybridization and real-time PCR. There was no detectable Cryab mRNA signal on days 1–4 of pregnancy. On day 5 of pregnancy when embryo implanted, a high level of Cryab mRNA signal was found in the subluminal stroma surrounding the implanting blastocyst. On days 6–8, Cryab mRNA was strongly expressed in the primary decidua. By real-time PCR, a high level of Cryab expression was detected on days 7 and 8 of pregnancy, although Cryab expression was seen from days 1 to 8. Under in vivo and in vitro artificial decidualization, Cryab expression was significantly elevated. Compared with the progesterone-primed delayed implantation uterus, a high level of Cryab mRNA expression was observed in estrogen-activated implantation uterus. In the uterine stromal cells, cAMP, estrogen, and progesterone could induce the expression of Cryab gene. In the ovariectomized mouse uterus, estrogen could also induce the expression of Cryab while progesterone inhibited its expression. Our data suggest that Cryab may play an important role during mouse embryo implantation and decidualization and that estrogen and progesterone can regulate the expression of Cryab gene.
Yun-Kao Cao, Zhi-Sheng Zhong, Da-Yuan Chen, Gui-Xue Zhang, Heide Schatten and Qing-Yuan Sun
The small GTPase Ran controls numerous cellular processes of the mitotic cell cycle. In this experiment, we investigated the localization and possible roles of Ran during mouse oocyte meiotic maturation, fertilization and early cleavage by using confocal laser scanning microscopy, antibody microinjection and microtubule disturbance. The results showed that Ran was localized mainly in the nucleus (except for the nucleolus) in the oocyte, zygote and early embryo. At pro-metaphase of meiosis I, Ran distributed throughout the cell, but predominantly concentrated around the condensed chromosomes. During the completion of meiosis I and meiosis II, it concentrated to the meiotic spindle microtubules except for the midbody region. After sperm penetration, Ran dispersed with the extrusion of the second polar body and gradually concentrated in the male and female pronuclei thereafter. Ran was also observed to exist diffusely in the cytoplasm in prophase; it concentrated at the mitotic spindle, and migrated to the nucleus during early cleavage. Ran’s concentration around the spindle disappeared when microtubule assembly was inhibited by colchicine, while it was concentrated around the chromosomes after microtubule stabilization with taxol treatment. Ran did not display any role in cytokinesis during division when pseudo-cleavage of germinal vesicle-intact oocytes was induced. Anti-Ran antibody microinjection decreased the germinal vesicle breakdown and the first polar body extrusion, and distorted spindle organization and chromosome alignment. Our results indicate that Ran has a cell cycle-dependent localization and may have regulatory roles in cell cycle progression and microtubule organization in mouse oocytes, fertilized eggs and early embryos.
Wen-Lin Chang, Qing Yang, Hui Zhang, Hai-Yan Lin, Zhi Zhou, Xiaoyin Lu, Cheng Zhu, Li-Qun Xue and Hongmei Wang
Placenta-specific protein 1 (PLAC1), a placenta-specific gene, is known to be involved in the development of placenta in both humans and mice. However, the precise role of PLAC1 in placental trophoblast function remains unclear. In this study, the localization of PLAC1 in human placental tissues and its physiological significance in trophoblast invasion and migration are investigated by technical studies including real-time RT-PCR, in situ hybridization, immunohistochemistry, and functional studies by utilizing cell invasion and migration assays in the trophoblast cell line HTR8/SVneo as well as the primary inducing extravillous trophoblasts (EVTs). The results show that PLAC1 is mainly detected in the trophoblast columns and syncytiotrophoblast of the first-trimester human placental villi, as well as in the EVTs that invade into the maternal decidua. Knockdown of PLAC1 by RNA interference significantly suppresses the invasion and migration of HTR8/SVneo cells and shortens the distance of the outgrowth of the induced EVTs from the cytotrophoblast column of the explants. All the above data suggests that PLAC1 plays an important role in human placental trophoblast invasion and migration.
Cheng Zeng, Pei-Li Wu, Zhao-Tong Dong, Xin Li, Ying-Fang Zhou and Qing Xue
Endometriosis is an estrogen-dependent disease, and estrogen receptor 2 (ESR2) plays a critical role in the pathogenesis of ovarian endometriosis by promoting cell invasion. Yes-associated protein 1 (YAP1) plays suppressive roles in several types of tumors. However, the relationship between YAP1 and ESR2 is not fully understood. The aim of this study was to investigate the regulatory mechanism of YAP1 in terms of ESR2 and YAP1 regulation of endometriotic stromal cell (ECSC) invasion in ovarian endometriosis. Our results demonstrated that YAP1 mRNA and protein levels in eutopic endometrium (EU) tissues were higher than those in paired ectopic endometrium (EC) tissues. ECSCs transfected with siYAP1 exhibited a significant increase in both ESR2 mRNA levels and protein expression. Simultaneously, YAP1 overexpression in ECSCs yielded the opposite results. Co-IP assays demonstrated YAP1-NuRD complex formation by YAP1, CHD4 and MTA1 in ECSCs. YAP1 bound to two sites, (-539, -533) and (-158, -152), upstream of the ESR2 transcription initiation site. YAP1 binding to the two sites of the ESR2 promoter in ECSCs was significantly lower than that in eutopic endometrial stromal cells (EUSCs) from EU tissues. ECSCs transfected with siYAP1 exhibited increased invasion activity, while ECSCs transfected with siESR2 showed inhibition of invasion. However, transfection with siYAP1 and siESR2 together decreased the number of invading cells compared with transfection with siYAP1 alone. Therefore, we conclude that decreased levels of YAP1 in ovarian endometriomas enhance ESR2 expression via formation of a YAP1-NuRD complex, which further binds to the ESR2 promoters. Furthermore, YAP1 inhibits ECSCs invasion.
Xue-Min Qiu, Zhen-Zhen Lai, Si-Yao Ha, Hui-Li Yang, Li-Bing Liu, Yan Wang, Jia-Wei Shi, Lu-Yu Ruan, Jiang-Feng Ye, Jiang-Nan Wu, Qiang Fu, Xiao-Fang Yi, Kai-Kai Chang and Ming-Qing Li
Immune cells and cytokines have important roles in the pathogenesis of endometriosis. However, the production and role of cytokines of T helper type 1 (Th1) and Th2 cells in the progress of endometriosis have remained to be fully elucidated. The present study reported that the interferon (IFN)-γ levels and the percentage of IFN-γ+CD4+ cells were significantly increased in the peritoneal fluid (PF) at the early stage and maintained at a higher level at the advanced stage of endometriosis; furthermore, interleukin (IL)-10 and IL-10+CD4+ cells were elevated in the advanced stage of endometriosis. In addition, IL-2 levels in the PF at the advanced stage of endometriosis were elevated and negatively associated with IFN-γ expression. In a co-culture system of ectopic endometrial stromal cells (ESCs) and macrophages, elevated IL-2 was observed, and treatment with cytokines IL-2 and transforming growth factor-β led to upregulation of the ratio of IL-2+ macrophages. IL-27-overexpressing ESCs and macrophages were able to induce a higher ratio of IL-10+CD4+ T cells. Blocking of IL-2 with anti-IL-2 neutralizing antibody led to upregulation of the ratio of IFN-γ+CD4+ T cells in the co-culture system in vitro. Recombinant human IL-10 and IFN-γ promoted the viability, invasiveness and transcription levels of matrix metalloproteinase (MMP)2, MMP9, and prostaglandin-endoperoxide synthase 2 of ESCs, particularly combined treatment with IL-10 and IFN-γ. These results suggest that IL-2 and IL-27 synergistically promote the growth and invasion of ESCs by modulating the balance of IFN-γ and IL-10 and contribute to the progress of endometriosis.