Search for other papers by Isabella G Cossu in
Google Scholar
PubMed
Search for other papers by N Adrian Leu in
Google Scholar
PubMed
College of Life Sciences, Capital Normal University, Beijing, China
Search for other papers by Yongjuan Guan in
Google Scholar
PubMed
Search for other papers by P Jeremy Wang in
Google Scholar
PubMed
In brief
The dissociation of HORMA domain protein 2 (HORMAD2) from the synaptonemal complex is tightly regulated. This study reveals that the N-terminal region of HORMAD2 is critical for its dissociation from synapsed meiotic chromosomes.
Abstract
During meiosis, homologous chromosomes undergo synapsis and recombination. HORMA domain proteins regulate key processes in meiosis. Mammalian HORMAD1 and HORMAD2 localize to unsynapsed chromosome axes but are removed upon synapsis by the TRIP13 AAA+ ATPase. TRIP13 engages the N-terminal region of HORMA domain proteins to induce an open conformation, resulting in the disassembly of protein complexes. Here, we report introduction of a 3×FLAG-HA tag to the N-terminus of HORMAD2 in mice. Coimmunoprecipitation coupled with mass spectrometry identified HORMAD1 and SYCP2 as HORMAD2-associated proteins in the testis. Unexpectedly, the N-terminal tagging of HORMAD2 resulted in its abnormal persistence along synapsed regions in pachynema and ectopic localization to telomeres in diplonema. Super-resolution microscopy revealed that 3×FLAG-HA-HORMAD2 was distributed along the central region of the synaptonemal complex, whereas wild-type HORMAD1 persisted along the lateral elements in 3×FLAG-HA-HORMAD2 meiocytes. Although homozygous mice completed meiosis and were fertile, homozygous males exhibited a significant reduction in sperm count. Collectively, these results suggest that the N-terminus of HORMAD2 is important for its timely removal from meiotic chromosome axes.
Search for other papers by Zoe M G Skalkos in
Google Scholar
PubMed
Search for other papers by James U Van Dyke in
Google Scholar
PubMed
Search for other papers by Samson N Dowland in
Google Scholar
PubMed
Search for other papers by Camilla M Whittington in
Google Scholar
PubMed
In brief
Seahorses exhibit male pregnancy and are thus valuable comparative models for the study of the physiology and evolution of pregnancy. This study shows that protein is transported from fathers to developing embryos during gestation, and provides new knowledge about paternal contributions to embryonic development.
Abstract
Syngnathid embryos (seahorses, pipefishes and seadragons) develop on or in the male in a specialised brooding structure (brood pouch). Seahorse brood pouches supply nutrients, including lipids, to developing embryos (patrotrophy). We tested the hypothesis that proteins, vital for gene regulation and tissue growth during embryogenesis, are also transported from father to embryos, using the Australian pot-bellied seahorse, Hippocampus abdominalis. We used dry masses and total nitrogen content to estimate the total protein content of newly fertilised egg and neonate H. abdominalis. Neonates contained significantly greater protein mass than newly fertilised eggs. This result indicates that paternal protein transport to developing embryos occurs during H. abdominalis pregnancy. This study is the first to show paternal protein transport during pregnancy in seahorses, and furthers our understanding of paternal influence on embryonic development in male pregnant vertebrates.
Search for other papers by Monika Fluks in
Google Scholar
PubMed
Search for other papers by Robert Milewski in
Google Scholar
PubMed
Search for other papers by Szymon Tamborski in
Google Scholar
PubMed
Search for other papers by Maciej Szkulmowski in
Google Scholar
PubMed
Search for other papers by Anna Ajduk in
Google Scholar
PubMed
In brief
Optical coherence microscopy non-invasively visualizes metaphase II spindles allowing for quantitative analysis of their volume and shape, which may prove useful in the assessment of the oocyte quality. Using a mouse model, we showed also that analysis of spindle length combined with morphokinetics improves the evaluation of the resulting embryos.
Abstract
The proper development of embryos strongly depends on the quality of oocytes, so the evaluation of oocytes may be a useful initial step in IVF procedures. Additionally, it enables embryologists to make more informed decisions regarding the treatments chosen for the patients and better manage patients’ expectations. Optical coherence microscopy (OCM) allows for non-invasive 3D visualization of intracellular structures, such as spindles or nuclei, which have been linked to the success of embryonic development. Here, we applied a mouse model to examine whether OCM imaging could be used in the quality assessment of metaphase II (MII) oocytes. We showed that quantitative parameters describing the shape and volume of the MII spindle were associated with the quality of the resulting embryos, including the likelihood of blastocyst formation and the embryos’ ability to differentiate the trophectoderm and primitive endoderm, but not the epiblast. We also created a multivariate linear regression model, combining OCM-based quantification of MII spindles with morphokinetic analysis of the embryos, that allowed for improved evaluation of the embryo quality. Finally, we proved that OCM does not interfere with the viability of the scanned cells, at least during the preimplantation development. Therefore, we believe that OCM-based quantitative assessment of MII spindles can improve the oocyte and embryo selection in IVF procedures.
Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
Institute of Birth Defects and Rare Diseases, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
Search for other papers by Chuan-Mei Qin in
Google Scholar
PubMed
Search for other papers by Xiao-Wei Wei in
Google Scholar
PubMed
Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
Institute of Birth Defects and Rare Diseases, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
Search for other papers by Jia-Yi Wu in
Google Scholar
PubMed
Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
Institute of Birth Defects and Rare Diseases, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
Search for other papers by Xue-Qing Liu in
Google Scholar
PubMed
Search for other papers by Yi Lin in
Google Scholar
PubMed
In brief
The proliferation of the endometrium is regulated by histone methylation. This study shows that decreased NSD2 impairs proliferative-phase endometrial stromal cell proliferation in patients with recurrent implantation failure via epigenetic reprogramming of H3K36me2 methylation on the promoter region of MCM7.
Abstract
Recurrent implantation failure (RIF) is a formidable challenge in assisted reproductive technology because of its unclear molecular mechanism. Impaired human endometrial stromal cell (HESC) proliferation disrupts the rhythm of the menstrual cycle, resulting in devastating disorders between the embryo and the endometrium. The molecular function of histone methylation enzymes in modulating HESC proliferation remains largely uncharacterized. Herein, we found that the levels of histone methyltransferase nuclear receptor binding SET domain protein 2 (NSD2) and the dimethylation of lysine 36 on histone H3 are decreased significantly in the proliferative-phase endometrium of patients with RIF. Knockdown of NSD2 in an HESC cell line markedly impaired cell proliferation and globally reduced H3K36me2 binding to chromatin, leading to altered expression of many genes. Transcriptomic analyses revealed that cell cycle-related gene sets were downregulated in the endometrium of patients with RIF and in NSD2‑knockdown HESCs. Furthermore, RNA-sequencing and CUT&Tag sequencing analysis suggested that NSD2 knockdown reduced the binding of H3K36me2 to the promoter region of cell cycle marker gene MCM7 (encoding minichromosome maintenance complex component 7) and downregulated its expression. The interaction of H3K36me2 with the MCM7 promoter was verified using chromatin immunoprecipitation–quantitative real-time PCR. Our results demonstrated a unifying epigenome-scale mechanism by which decreased NSD2 impairs endometrial stromal cell proliferation in the proliferative-phase endometrium of patients with RIF.
Search for other papers by Vakil Ahmad in
Google Scholar
PubMed
Search for other papers by Sai Goutham Reddy Yeddula in
Google Scholar
PubMed
Search for other papers by Bhanu P Telugu in
Google Scholar
PubMed
Department of Obstetrics, Gynecology, and Women’s Health, University of Missouri, Columbia, Missouri, USA
Search for other papers by Thomas E Spencer in
Google Scholar
PubMed
Search for other papers by Andrew M Kelleher in
Google Scholar
PubMed
In brief
Polarity-reversed endometrial epithelial organoids exhibit histological and physiological characteristics resembling uterine epithelium in vivo, respond to hormones, and undergo secretory cell transformation. The ability to modify the polarity without impairing functionality, coupled with successful coculture with microbial and embryonic entities, paves the way for investigating complex interactions at the endometrial epithelial surface.
Abstract
The uterine epithelium comprises a single layer of hormone-responsive polarized epithelial cells that line the lumen and form tubular glands. Endometrial epithelial organoids (EEO) can be generated from uterine epithelia and recapitulate cell composition and hormone responses in vitro. As such, the development of EEO represents a significant advance in facilitating mechanistic studies in vitro. However, a major limitation of the use of EEO cultured in basement membrane extract and other hydrogels is the inner location of the apical membrane (apical-in EEO), thereby hindering direct access to the apical surface of the epithelium to study interactions with the embryo or infectious agents such as viruses and bacteria. To address this challenge, we developed a suspension culture method to reverse the polarity of EEO. The result is an apical-out organoid that preserves a distinct apical–basolateral orientation and remains responsive to ovarian steroid hormones. Apical-out EEO were positive for the gland marker, FOXA2, and exhibited appropriate hormonal regulation of steroid hormone receptor expression. Notably, progesterone treatment resulted in secretory transformation in apical-out EEO, including a decrease in microvilli and cilia, and an increase in secretory granules. Likewise, reflective of in vivo conditions, ENPP3, a P4-regulated gene, was localized apically in steroid hormone-treated organoids. Coculture experiments with apical out EEO demonstrate the model’s utility in studying uterine epithelium interactions with bacteria (E. coli) and blastocysts. The apical out EEO model lays the foundation for developing new in vitro functional assays, particularly regarding epithelial interactions with embryos during pregnancy or other luminal constituents in a pathological or diseased state.
Search for other papers by Mathieu Douhard in
Google Scholar
PubMed
Search for other papers by Victor Ronget in
Google Scholar
PubMed
Search for other papers by Frédéric Douhard in
Google Scholar
PubMed
In brief
In litter-bearing species, developing offspring can be exposed to different concentrations of androgens and oestrogens according to the sex of neighbouring fetuses. However, the relationships between litter sex composition and subsequent reproductive performance are discordant and complex.
Abstract
Laboratory studies with rodents indicate that in utero proximity of a female to male fetus can affect female’s subsequent reproduction due to elevated testosterone exposure during early development. It remains unknown whether these findings can be generalised to non-laboratory species because the need for caesarean section makes it difficult to determine the intrauterine position outside laboratory conditions. As an alternative, some studies have compared the reproductive performance of individuals born in male-biased litters to those born in female-biased litters. We identified 44 of those studies in 28 viviparous species for a total of 176 relationships between litter sex composition around the time of birth and subsequent reproductive performance (fertility, fecundity, age at first reproduction, interbirth intervals or post-natal survival of offspring). Those relationships are discordant and complex both within and across species. Some factors can mask an actual association between litter sex composition and reproductive performance. Conversely, a part of significant relationships between litter sex composition and reproductive performance likely arises via pathways other than androgen- and oestrogen-transfer between fetuses of different sexes.
Mercy Perinatal, Mercy Hospital for Women, Heidelberg, Australia
Search for other papers by Bridget M Arman in
Google Scholar
PubMed
Mercy Perinatal, Mercy Hospital for Women, Heidelberg, Australia
Search for other papers by Natalie K Binder in
Google Scholar
PubMed
Mercy Perinatal, Mercy Hospital for Women, Heidelberg, Australia
Search for other papers by Natasha de Alwis in
Google Scholar
PubMed
Search for other papers by Sally Beard in
Google Scholar
PubMed
Search for other papers by Anjali Garg in
Google Scholar
PubMed
Translational Obstetrics Group, Department of Obstetrics and Gynaecology, University of Melbourne, Mercy Hospital for Women, Heidelberg, Victoria, Australia
Search for other papers by Tu’uhevaha J Kaitu’u-Lino in
Google Scholar
PubMed
Mercy Perinatal, Mercy Hospital for Women, Heidelberg, Australia
Search for other papers by Natalie J Hannan in
Google Scholar
PubMed
In brief
Preterm birth is the leading cause of perinatal morbidity and mortality, and new therapies that delay preterm birth and improve neonatal outcomes are urgently needed. This study investigates whether ticagrelor inhibits uterine contractility and inflammation in preclinical in vitro, ex vivo (human) and in vivo (mouse) studies, to explore the potential of repurposing ticagrelor for the prevention of preterm birth.
Abstract
Preterm birth remains a significant global health challenge, affecting approximately 10% of pregnancies and resulting in one million deaths globally every year. Tocolytic agents, used to manage preterm labour, have considerable limitations including lack of efficacy, and adverse side effects, emphasising the urgent need for innovative solutions. Here, we explore repurposing an antiplatelet cardioprotective drug, ticagrelor, as a potential treatment to prevent preterm birth. Ticagrelor has demonstrated pleiotropic actions beyond platelet inhibition, including relaxant effects on smooth muscle cells and anti-inflammatory effects in models of diabetes and sepsis. As preterm birth is underscored by inflammatory processes triggering uterine contractions, these actions position ticagrelor as an attractive candidate for prevention or delay of preterm birth. Utilising primary human myometrial tissue, human myometrial cells, and a mouse model of preterm birth, we investigated ticagrelor’s potential as a safe and effective therapy for preterm birth. We showed that ticagrelor did not reduce the frequency or strength of spontaneous muscle contractions of ex vivo myometrial tissue nor did it reduce in vitro inflammation-induced contractility in myometrial cells. Additionally, ticagrelor did not exhibit the anticipated anti-inflammatory effects in myometrial cell culture experiments. In our mouse model of preterm birth, ticagrelor neither improved the preterm birth rate or fetal survival outcomes. Gene expression of pro-inflammatory cytokines and contraction-associated proteins in postpartum mouse uteri were unaltered by ticagrelor. In conclusion, ticagrelor is not a strong candidate to continue investigations in clinical trial for the treatment of preterm labour and prevention of preterm birth.
Search for other papers by Luisa Gioia in
Google Scholar
PubMed
Search for other papers by Luca Palazzese in
Google Scholar
PubMed
Search for other papers by Marta Czernik in
Google Scholar
PubMed
Search for other papers by Domenico Iuso in
Google Scholar
PubMed
Search for other papers by Helena Fulka in
Google Scholar
PubMed
Search for other papers by Josef Fulka Jr in
Google Scholar
PubMed
Search for other papers by Pasqualino Loi in
Google Scholar
PubMed
The fertilizing spermatozoa induce a Ca2+ oscillatory pattern, the universal hallmark of oocyte activation, in all sexually reproducing animals. Assisted reproductive technologies (ARTs) like intracytoplasmic sperm injection (ICSI) bypass the physiological pathway; however, while a normal Ca2+ release pattern occurs in some species, particularly humans, artificial activation is compulsory for ICSI-fertilized oocytes to develop in most farm animals. Unlike the normal oscillatory pattern, most artificial activation protocols induce a single Ca2+ spike, undermining proper ICSI-derived embryo development in these species. Curiously, diploid parthenogenetic embryos activated by the same treatments develop normally at high frequencies and implant upon transfer in the uterus. We hypothesized that, at least in ruminant embryos, the oscillatory calcium waves late in the first cell cycle target preferentially the paternal pronucleus and are fundamentally important for paternal nuclear remodeling. We believe that Ca2+ signaling is central to full totipotency deployment of the paternal genome. Research in this area could highlight the asymmetry between the parental genome reprogramming timing/mechanisms in early development and impact ARTs like ICSI and cloning.
Search for other papers by Meng Ma in
Google Scholar
PubMed
Search for other papers by Shutian Jiang in
Google Scholar
PubMed
Search for other papers by Wei Jin in
Google Scholar
PubMed
Search for other papers by Wenzhi Li in
Google Scholar
PubMed
Search for other papers by Chen Chen in
Google Scholar
PubMed
Search for other papers by Kaibo Lin in
Google Scholar
PubMed
Search for other papers by Xiaoyu Liao in
Google Scholar
PubMed
Search for other papers by Danjun Li in
Google Scholar
PubMed
Search for other papers by Yanping Kuang in
Google Scholar
PubMed
Search for other papers by Qifeng Lyu in
Google Scholar
PubMed
In brief
The impact of HVJ-E employed in mitochondrial replacement techniques (MRTs) on embryonic development remains uncertain. This study has exhibited the influence of HVJ-E utilized in MRTs on embryonic development and has devised a novel HVJ-E-induced fusion approach to curtail the amount of HVJ-E employed in MRTs.
Abstract
Mitochondrial replacement techniques (MRTs) provide a viable option for women carrying pathogenic mitochondrial DNA (mtDNA) variants to conceive disease-free offspring with a genetic connection. In comparison to electrofusion, HVJ-E-induced fusion has been identified as the most promising approach for clinical translation of MRTs due to its absence of electrical interference. However, despite confirmation of the absence of RNA activity in HVJ-E, a reduction in blastocyst quality has been observed in various MRTs studies utilizing the HVJ-E-induced fusion scheme. Recent investigations have revealed a dose-dependent elevation of reactive oxygen species (ROS) levels in various cancer cells incubated with HVJ-E. However, the impact of HVJ-E as a sole determinant on embryonic development in MRTs remains unverified. This investigation establishes that the augmented concentration of HVJ-E utilized in the conventional HVJ-E fusion protocol is an autonomous variable that influences embryonic development in MRTs. This effect may be attributed to amplified DNA damage resulting from heightened levels of ROS in reconstructed embryos. To mitigate the presence of HVJ-E in reconstructed zygotes while maintaining optimal fusion efficiency in MRTs, a novel HVJ-E-induced fusion approach was devised, namely, press-assisted fusion. This technique offers potential advantages in reducing detrimental factors that impede embryo development in MRTs.
Search for other papers by Xiaotong Wu in
Google Scholar
PubMed
Search for other papers by Yan Shi in
Google Scholar
PubMed
Search for other papers by Bingjie Hu in
Google Scholar
PubMed
Search for other papers by Panpan Zhao in
Google Scholar
PubMed
Search for other papers by Shuang Li in
Google Scholar
PubMed
Search for other papers by Lieying Xiao in
Google Scholar
PubMed
Search for other papers by Shaohua Wang in
Google Scholar
PubMed
Search for other papers by Kun Zhang in
Google Scholar
PubMed
In brief
Lineage specification plays a vital role in preimplantation development. TEAD4 is an essential transcription factor for trophectoderm lineage specification in mice but not in cattle.
Abstract
Tead4, a critical transcription factor expressed during preimplantation development, is essential for the expression of trophectoderm-specific genes in mice. However, the functional mechanism of TEAD4 in mouse preimplantation development and its conservation across mammals remain unclear. Here, we report that Tead4 is a crucial transcription factor necessary for blastocyst formation in mice. Disruption of Tead4 through base editing results in developmental arrest at the morula stage. Additionally, RNA-seq analysis reveals dysregulation of 670 genes in Tead4 knockout embryos. As anticipated, Tead4 knockout led to a decrease in trophectoderm genes Cdx2 and Gata3. Intriguingly, we observed a reduction in Krt8, suggesting that Tead4 influences the integrity of the trophectoderm epithelium in mice. More importantly, we noted a dramatic decrease in nuclear Yap in outside cells for Tead4-deficient morula, indicating that Tead4 directly regulates Hippo signaling. In contrast, bovine embryos with TEAD4 depletion could still develop to blastocysts with normal expression of CDX2, GATA3, and SOX2, albeit with a decrease in total cell number and ICM cell number. In conclusion, we propose that Tead4 regulates mouse blastocyst formation via Krt8 and Yap, both of which are critical regulators of mouse preimplantation development.
