Peri-ovarian adipose tissue (POAT) is a kind of intra-abdominal white adipose tissue that is present surrounding the ovaries in rodents. Recent studies demonstrated that POAT-deficient mice displayed a phenotype of delayed antral follicular development, for which decreases in serum estrogen, serum FSH and FSHR levels were responsible. However, folliculogenesis is regulated by endocrine signals and also modulated by a number of locally produced intraovarian factors whose acts are both autocrine and paracrine. Here, we used a model of surgical removal of POAT unilaterally and contralateral ovaries as controls, as both were under the same endocrine control, to assess the paracrine effect of the POAT on folliculogenesis. Surgical removal of unilateral POAT resulted in delayed antral follicular development and the increased number of atretic follicles, accompanied by decreased levels of intraovarian adipokines and growth factors, lipid accumulation and steroidogenic enzyme expression. POAT-deficient ovaries displayed compensatory increased expressions of intraovarian genes, such as Vegf and Adpn for angiogenesis, Acc, Fasn, and Gapdh involved in lipogenesis and Fshr in response to FSH stimulation. Furthermore, we demonstrated that removal of POAT promoted follicular apoptosis, caused retention of cytoplasmic YAP and inhibited PTEN-AKT-mTOR activation. These alterations were observed only in the POAT-deficient ovaries but not in the contralateral ovaries (with POAT), which suggests that a paracrine interaction between POAT and ovaries is important for normal folliculogenesis.
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Liuhong Yang, Lei Chen, Xiaosheng Lu, Anni Tan, Yao Chen, Yalan Li, Xuemei Peng, Shaochun Yuan, Dongqing Cai, and Yanhong Yu
Yang Yu, Chenhui Ding, Eryao Wang, Xinjie Chen, Xuemei Li, Chunli Zhao, Yong Fan, Liu Wang, Nathalie Beaujean, Qi Zhou, Alice Jouneau, and Weizhi Ji
Even though it generates healthy adults, nuclear transfer in mammals remains an inefficient process. Mainly attributed to abnormal reprograming of the donor chromatin, this inefficiency may also be caused at least partly by a specific effect of the cloning technique which has not yet been well investigated. There are two main procedures for transferring nuclei into enucleated oocytes: fusion and piezoelectric microinjection, the latter being used mostly in mice. We have, therefore, decided to compare the quality and the developmental ability, both in vivo and in vitro, of embryos reconstructed with electrofusion or piezoelectric injection. In addition, the effect of piezo setups of differing electric strengths was investigated. Along with the record of the rate of development, we compared the nuclear integrity in the blastomeres during the first cleavages as well as the morphological and cellular quality of the blastocysts. Our results show that the piezo-assisted micromanipulation can induce DNA damage in the reconstructed embryos, apoptosis, and reduced cell numbers in blastocysts as well as a lower rate of development to term. Even if piezo-driven injection facilitates a faster and more efficient rate of reconstruction, it should be used with precaution and with as low parameters as possible.
Hong-Lan Song, Tai-Hang Liu, Yong-Heng Wang, Fang-Fang Li, Ling-Ling Ruan, Enoch Appiah Adu-Gyamfi, Si-Chen Hu, Xue-Mei Chen, Yu-Bin Ding, and Li-Juan Fu
The syncytiotrophoblast, derived from cytotrophoblast fusion, is responsible for maternal–fetal exchanges, secretion of pregnancy-related hormones, and fetal defense against pathogens. Inadequate cytotrophoblast fusion can lead to pregnancy disorders, such as preeclampsia and fetal growth restriction. However, little is known about the mechanism of cytotrophoblast fusion in both physiological and pathological pregnancy conditions. In this study, P57kip2 (P57), a cell cycle-dependent kinase inhibitor that negatively regulates the cell cycle, was found to be up-regulated during the process of syncytialization in both primary trophoblast cells and BeWo cells. Co-immunofluorescence with proliferation markers Ki67 and Cyclin-CDK factors further showed that P57 specifically localizes in the post-mitotic cytotrophoblast subtype of the early pregnancy villi. Overexpression of P57 promoted trophoblast syncytialization by arresting the cell cycle at the G1/G0 phase and inhibiting proliferation. Blocking of the cell cycle through a serum starvation culture resulted in an enhancement of cytotrophoblast fusion and the up-regulation of P57. In both spontaneous cytotrophoblast fusion and forskolin-induced BeWo cell fusion models, an initial up-regulation of P57 was observed followed by a subsequent down-regulation. These findings indicate that proper expression of P57 at cytotrophoblast differentiation nodes plays an important role in trophoblast syncytialization.
Xue Zhang, Bo-Yin Tan, Shuang Zhang, Qian Feng, Ying Bai, Shi-Quan Xiao, Xue-Mei Chen, Jun-Lin He, Xue-Qing Liu, Ying-Xiong Wang, Yu-Bin Ding, and Fang-Fang Li
Decidualization of uterine stromal cells plays an important role in the establishment of normal pregnancy. Previous studies have demonstrated that Acyl-CoA binding protein (Acbp) is critical to cellular proliferation, differentiation, mitochondrial functions, and autophagy. The characterization and physiological function of Acbp during decidualization remain largely unknown. In the present study, we conducted the expression profile of Acbp in the endometrium of early pregnant mice. With the occurrence of decidualization, the expression of Acbp gradually increased. Similarly, Acbp expression was also strongly expressed in decidualized cells following artificial decidualization, both in vivo and in vitro. We applied the mice pseudopregnancy model to reveal that the expression of Acbp in the endometrium of early pregnant mice was not induced by embryonic signaling. Moreover, P4 significantly upregulated the expression of Acbp, whereas E2 appeared to have no regulating effect on Acbp expression in uterine stromal cells. Concurrently, we found that interfering with Acbp attenuated decidualization, and that might due to mitochondrial dysfunctions and the inhibition of fatty acid oxidation. The level of autophagy was increased after knocking down Acbp. During induced decidualization, the expression of ACBP was decreased with the treatment of rapamycin (an autophagy inducer), while increased with the addition of Chloroquine (an autophagy inhibitor). Our work suggests that Acbp plays an essential role in the proliferation and differentiation of stromal cells during decidualization through regulating mitochondrial functions, fatty acid oxidation, and autophagy.