Reproduction最新文献

Abstract

Ovarian cancer (OC) is the third most common kind of gynecological tumor, in addition to being the most lethal. Transcription factor Dp-1 (TFDP1) functions as a binding partner for E2F transcription factors, and its target genes include those involved in DNA synthesis, cell cycle, and apoptosis. However, the regulatory role of TFDP1 in OC remains incompletely understood. This study aimed to investigate the role and mechanism of TFDP1 in OC. TFDP1 was highly expressed in the ovarian epithelial tissues of OC patients, and the expression of TFDP1 in OC cells was higher than that in normal ovarian epithelial cells. Silencing of TFDP1 inhibited the biological activity of OC cells and hindered cell cycle entry. Zinc finger protein 146 (ZNF146) knockdown induced cell cycle arrest at the G0/G1 phase and tumor growth by blocking TFDP1 transcription, which was overturned by ectopic expression of TFDP1. TFDP1 stimulated DEP domain-containing protein 1B (DEPDC1B) expression through transcriptional activation. DEPDC1B increased the proportion of OC cells in the G2/M phase and potentiated tumor malignant progression in nude mice inhibited by sh-ZNF146. Taken together, these findings demonstrate that ZNF146 participates in TFDP1/DEPDC1B activation and plays a vital role in the cell cycle in OC.

Female infertility disproportionately affects people with obesity. Exercise often improves fertility outcomes for this population, however, there is limited prescriptive evidence. Specifically, there is a lack of information on the ideal type, frequency, intensity, and setting of exercise to improve fertility outcomes. Using principles of exercise prescription, this review aimed to describe the scope of exercise interventions that have been explored and fertility outcomes measured for people with female infertility and obesity. A search was completed in PubMed, Embase, Cochrane, and CINAHL, identifying 16 relevant published articles. Overall, exercise had a positive impact on female fertility outcomes in people with obesity, though there were large variations in the exercise interventions prescribed and outcomes measured. Cyclic exercise (i.e., walking, cycling) was the most common technique incorporated, though a combination of cyclic, acyclic (i.e., circuit training, boot camp), or individualization was often used. Several fertility outcomes were reported; however, rate of conception, pregnancy, and live birth rates were the most common, which, we suggest, should always be reported in fertility intervention research. We stress that future studies provide more thorough descriptions of their implemented exercise interventions to facilitate reproducibility and comparisons between studies. Closer attention to the principles of exercise prescription when developing and reporting exercise interventions will help improve fertility outcomes, mainly live birth rates, for those with female infertility and obesity.

Social insects present an extraordinary opportunity as models for reproductive longevity because they challenge the conventional patterns of aging and reproduction seen in other model organisms. Their queens are simultaneously long-lived and highly fecund, and understanding how these traits co-occur may lead to discoveries with important implications for human health.

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.

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.

The cryopreservation of in vitro produced (IVP) embryos is vital in the cattle industry for genetic selection and crossbreeding programs. Despite its importance, there is no standardized protocol yielding pregnancy rates comparable to fresh embryos. Current approaches often neglect the osmotic tolerance responses to cryoprotectants based on temperature and time. Hereby, we propose improved vitrification methods using shorter dehydration-based protocols. Blastocysts cultured for 7 (D7) or 8 days (D8) were exposed to standard equilibration solution (ES) at 25ºC and 38.5ºC. Optimized exposure times for each temperature and their impact in post-warming re-expansion, hatching rates, cell counts, and apoptosis rate were determined. In silico predictions aligned with in vitro observations, showing original volume recovery within 8min 30s at 25ºC or 3min 40s at 38.5ºC (D7 blastocysts) and 4min 25s at 25ºC and 3min 15s at 38.5ºC (D8 blastocysts) after exposure to ES. Vitrification at 38.5ºC resulted in D7 blastocysts re-expansion and hatching rates (93.1% and 38.1%, respectively) comparable to fresh embryos (100.0% and 32.4%, respectively), outperforming the 25ºC protocol (86.2% and 24.4%, respectively; P<0.05). No differences were observed between D7 and D8 blastocysts using the 38.5ºC protocol. Total cell number was maintained for D7 and D8 blastocysts vitrified at 38.5ºC but decreased at 25ºC (P<0.05). Apoptosis rates increased post-warming (P<0.05), except for D8 blastocysts vitrified at 38.5ºC, resembling fresh controls. In conclusion, based on biophysical permeability data, new ES incubation times of 3min 40s for D7 blastocysts and 3min 15s for D8 blastocysts at 38.5ºC were validated for optimizing vitrification/warming methods for bovine IVP blastocysts.

Dairy cows go through a period of subfertility after parturition, triggered in part by a disruption of energy homeostasis. The mobilization of bodyfat alters the secretion of adipokines, which have been shown to impact ovarian function. Fibronectin type III domain-containing 3A (FNDC3A) is a recently discovered adipokine-myokine, and FNDC3A mRNA abundance in subcutaneous adipose tissue is increased post-partum in cattle. In this study, we hypothesized that FNDC3A may compromise granulosa cell function in cattle and investigated this using a well-established in vitro cell culture model. Here, we demonstrate the presence of FNDC3A protein associated with extracellular vesicles in follicular fluid and in plasma, suggesting an endocrine role for this adipokine. FNDC3A protein and mRNA was also detected in the bovine ovary (cortex, granulosa and theca cells, cumulus, oocyte and corpus luteum). Abundance of FNDC3A mRNA in granulosa cells from small follicles was increased by in vitro treatment with the adipokines leptin and TNFα but not by visfatin, resistin, adiponectin, chemerin or IGF1. Addition of recombinant FNDC3A at physiological doses (10 ng/ml) to granulosa cells decreased IGF1-dependent progesterone but not estradiol secretion and IGF1-dependent lactate secretion and abundance of GLUT3 and GLUT4 mRNA. This concentration of FNDC3A increased cell viability, abundance of mRNA encoding a putative receptor FOLR1, and increased phosphorylation of Akt. Collectively, these data suggest that FNDC3A may regulate folliculogenesis in cattle by modulating IGF1-dependent granulosa cell steroidogenesis and glucose metabolism.

Early embryo development requires the differentiation of three cell lineages in two differentiation events. The second lineage specification differentiates the inner cell mass into epiblast, which will form the proper foetus, and hypoblast, which together with the trophectoderm will form the extraembryonic membranes and the foetal part of the placenta. MEK signalling pathway is required for hypoblast differentiation in mouse embryos, but its role in ungulate embryos remains controversial. The aim of this work was to analyse the role of MEK signalling on hypoblast specification at the blastocyst stage, and on hypoblast migration during post-hatching stages in vitro in the ovine species. Using well-characterized and reliable lineage markers, and different MEK inhibitor concentrations, we demonstrate that MEK signalling pathway is required for hypoblast specification in the inner cell mass of the ovine blastocyst, and that it plays a role during the hypoblast migration occurring following blastocyst hatching. These results show that the role of MEK signalling pathway on hypoblast specification is conserved in phylogenetically distant mammals.

Recently, we described that in the naked mole-rat ovary it is possible to study the ovarian reserve and the mitotic expansion of the germ cell postnatally. Herein, we show oocyte in vitro maturation and in vitro germ cell expansion using the same ovary.

Transcription factor AP2 gamma (TFAP2C) is a well-established regulator of the trophoblast lineage in mice and humans, but a handful of studies indicate that TFAP2C may play an important role in pluripotency. Here, we hypothesize and provide new evidence that TFAP2C functions as an activator of trophoblast and pluripotency genes during preimplantation embryo development.