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Mengdie Li, Xiandong Peng, Jinfeng Qian, Fengrun Sun, Chunqin Chen, Songcun Wang, Jianping Zhang, and Meirong Du

To obtain a successful pregnancy, trophoblasts must provide a physical barrier, suppress maternal reactivity, produce immunosuppressive hormones locally, and enhance the production of blocking factors that are able to bind to several antigenic sites. Inadequate placental perfusion has been closely associated with several pregnancy-associated diseases. Galectin-9 (Gal-9) has a wide variety of regulatory functions in innate and adaptive immunity during infection, tumor growth, and organ transplantation. We utilized immortalized human first-trimester extravillous trophoblast cells (HTR8/SVneo) for our functional study and examined the effects of Gal-9 on apoptosis, cytokine production and angiogenesis of HTR8/SVneo cells. Gal-9 inhibited the apoptosis and IFN-γ and IL-17A production, promoted IL-4 production, and coordinated the crosstalk between HTR8/SVneo cells and human umbilical vein endothelial cells via its interaction with Tim-3. Blockade of JNK signaling inhibited Gal-9 activities in HTR8/SVneo cells. In addition, we detected a correlation between low levels of Gal-9 and spontaneous abortion. So Gal-9 could inhibit the apoptosis and proinflammatory cytokine expression, and promote the angiogenesis and IL-4 production in HTR8/SVneo cells via Tim-3 in a JNK dependent manner to help the maintenance of normal pregnancy. These findings possibly identify Gal-9 as a key regulator of trophoblast cells and suggest its potential as a biomarker and target for the treatment of recurrent pregnancy loss.

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Xiaoxu Chen, Qian Sun, Yi Zheng, Zidong Liu, Xiangqian Meng, Wenxian Zeng, and Hongzhao Lu

Infertility caused by male factors is routinely diagnosed by assessing traditional semen parameters. Growing evidence has indicated that the tsRNAs carried in sperm act as epigenetic factors and potential biomarkers for the assessment of sperm quality. We recently demonstrated that tRNAGln-TTG derived small RNAs played notable roles in the first cleavage of a porcine embryo. However, the function of human sperm tRNAGln-TTG derived small RNAs as a diagnostic biomarker and its role in early embryo development remains unclear. In this study, we found that human sperm tRNAGln-TTG derived small RNAs were highly associated with sperm quality. By microinjecting the antisense sequence into human tripronuclear (3PN) zygotes followed by single-cell RNA-sequencing, we found that human sperm tRNAGln-TTG derived small RNAs participated in the development of a human embryo. Furthermore, Gln-TTGs might influence embryonic genome activation by modulating noncoding RNA processing. These findings demonstrated that human sperm tRNAGln-TTG derived small RNAs could be potential diagnostic biomarkers and could be used as a clinical target for male infertility.

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Xiao-Qian Meng, Ke-Gang Zheng, Yong Yang, Man-Xi Jiang, Yan-Ling Zhang, Qing-Yuan Sun, and Yun-Long Li

Microfilaments (actin filaments) regulate various dynamic events during meiotic maturation. Relatively, little is known about the regulation of microfilament organization in mammalian oocytes. Proline-rich tyrosine kinase2 (Pyk2), a protein tyrosine kinase related to focal adhesion kinase (FAK) is essential in actin filaments organization. The present study was to examine the expression and localization of Pyk2, and in particular, its function during rat oocyte maturation. For the first time, by using Western blot and confocal laser scanning microscopy, we detected the expression of Pyk2 in rat oocytes and found that Pyk2 and Try402 phospho-Pyk2 were localized uniformly at the cell cortex and surrounded the germinal vesicle (GV) or the condensed chromosomes at the GV stage or after GV breakdown. At the metaphase and the beginning of anaphase, Pyk2 distributed asymmetrically both in the ooplasm and the cortex with a marked staining associated with the chromosomes and the region overlying the meiotic spindle. At telophase, Pyk2 was observed in the cleavage furrows in addition to its cortex and cytoplasm localization. The dynamics of Pyk2 were similar to that of F-actin, and this kinase was found to co-localize with microfilaments in several developmental stages during rat oocyte maturation. Microinjection of Pyk2 antibody demolished the microfilaments assembly and also inhibited the first polar body (PB1) emission. These findings suggest an important role of Pyk2 for rat oocyte maturation by regulating the organization of actin filaments.

Open access

Shou-Bin Tang, Lei-Lei Yang, Ting-Ting Zhang, Qian Wang, Shen Yin, Shi-Ming Luo, Wei Shen, Zhao-Jia Ge, and Qing-Yuan Sun

It is demonstrated that repeated superovulation has deleterious effects on mouse ovaries and cumulus cells. However, little is known about the effects of repeated superovulation on early embryos. Epigenetic reprogramming is an important event in early embryonic development and could be easily disrupted by the environment. Thus, we speculated that multiple superovulations may have adverse effects on histone modifications in the early embryos. Female CD1 mice were randomly divided into four groups: (a) spontaneous estrus cycle (R0); (b) with once superovulation (R1); (c) with three times superovulation at a 7-day interval (R3) and (d) with five times superovulation at a 7-day interval (R5). We found that repeated superovulation remarkably decreased the fertilization rate. With the increase of superovulation times, the rate of early embryo development was decreased. The expression of Oct4, Sox2 and Nanog was also affected by superovulation in blastocysts. The immunofluorescence results showed that the acetylation level of histone 4 at lysine 12 (H4K12ac) was significantly reduced by repeated superovulation in mouse early embryos (P < 0.01). Acetylation level of histone 4 at lysine 16 (H4K16ac) was also significantly reduced in pronuclei and blastocyst along with the increase of superovulation times (P < 0.01). H3K9me2 and H3K27me3 were significantly increased in four-cell embryos and blastocysts. We further found that repeated superovulation treatment increased the mRNA level of histone deacetylases Hdac1, Hdac2 and histone methyltransferase G9a, but decreased the expression level of histone demethylase-encoding genes Kdm6a and Kdm6b in early embryos. In a word, multiple superovulations alter histone modifications in early embryos.