Reproduction最新文献

In brief: Animal studies are needed to inform clinical guidance on the effects of testosterone gender-affirming hormone therapy (T-GAHT) on fertility. This review summarizes current animal models of T-GAHT and identifies gaps in knowledge for future study.

Abstract: Testosterone gender affirming hormone therapy (T-GAHT) is frequently used by transgender and gender-diverse individuals assigned female at birth to establish masculinizing characteristics. Although many seek parenthood, particularly as a gestational parent or through surrogacy, the current standard guidance of fertility counseling for individuals on testosterone (T) lacks clarity. At this time, individuals are typically recommended to undergo fertility preservation or stop treatment, associating T-therapy with a loss of fertility; however, there is an absence of consistent information regarding the true fertility potential for transgender and gender-diverse adults and adolescents. This review evaluates recent studies that utilize animal models of T-GAHT to relate to findings from clinical studies, with a more specific focus on fertility. Relevant literature based on murine models in post- and pre-pubertal populations has suggested reversibility of the impacts of T-GAHT, alone or following gonadotropin-releasing hormone agonist (GnRHa), on reproduction. These studies reported changes in clitoral area and ovarian morphology, including corpora lutea, follicle counts, and ovarian weights from T-treated mice. Future studies should aim to determine the impact of the duration of T-treatment and cessation on fertility outcomes, as well as establish animal models that are clinically representative of these outcomes with respect to gender diverse populations.

Sexual reproduction-from both physiological and behavioral perspectives-is dependent upon appropriate connections between a diverse, hormone-modulated network of neural regions. Importantly, these substrates are regulated by hormones across the lifespan from early development to adulthood, making them targets of endocrine-disrupting chemicals (EDCs). Rodents, such as mice and rats, are invaluable to the characterization of EDCs because of their sex-specific, stereotyped appetitive and consummatory reproductive behaviors. Phthalates, bisphenol A (BPA), and EDC mixtures pose a salient risk to the health of humans, wildlife, and livestock because these synthetic compounds are ubiquitous due to their widespread use in mass production of consumer and industrial goods. This review outlines how the hypothalamic-pituitary-gonadal axis regulates male and female sexual behaviors, and how phthalates and BPA can perturb appetitive and consummatory behaviors and impact neural substrates that modulate reproductive behavior. We will then discuss how to progress toward a clearer understanding of the reproductive and neurobiological changes that occur due to EDC exposure.

The significant role of C-type natriuretic peptide (CNP) and its receptor 2 (NPR2) in regulating oocyte meiotic maturation and facilitating communication between oocytes and surrounding cumulus cells has been well-documented in various mammalian species, including mice, cattle and swine. However, further investigation is needed to ascertain whether natriuretic peptide receptors (NPRs) are involved in regulating other essential ovarian functions. Hence, this study aimed to explore the potential involvement of NPRs in the regulation of cumulus expansion and oocyte meiotic maturation in bovine cumulus-oocyte complexes (COCs). The findings revealed that NPR3 mRNA abundance was downregulated by FSH and LH in cumulus cells of bovine COCs during in vitro maturation (IVM), while NPR2 mRNA levels were not affected by gonadotropins. Inhibition of the epidermal growth factor receptor (EGFR) during IVM of COCs prevented the NPR3 mRNA downregulation induced by gonadotropins in cumulus cells. Additionally, treatment of COCs during IVM with an NPR3 agonist (cANP4-23) inhibited cumulus expansion induced by gonadotropins. This inhibitory effect was further intensified when COCs were co-treated with cANP4-23 and CNP. These findings provide robust evidence indicating that normal cumulus expansion in bovine COCs involves an inhibitory effect of gonadotropins on NPR3 mRNA expression, which is mediated via EGFR signaling. The study also provides evidence that CNP and NPR3 interact synergistically to regulate cumulus expansion in response to gonadotropins.

Exposure to endocrine-disrupting chemicals (EDCs) and pharmaceuticals during development has been linked to reproductive dysfunction, reduced semen quality, and infertility. Research indicates that EDC mixtures, which are common in the modern environment, can pose significant risks that may not be fully assessed by studying individual compound toxicity, especially at environmentally relevant doses or concentrations. Understanding the contribution of chemical mixtures to male reproductive toxicity is crucial, given the increasing reliance on pharmaceuticals and pervasiveness of anthropogenic pollution. Recent studies on EDC effects have expanded to a more diverse range of microplastics, pesticides, antimicrobials, phytoestrogens, and pharmaceuticals such as analgesics, which can collectively impact testicular function and fertility. Adverse outcomes observed across studies include reproductive tract malformations, decreased sperm count and motility, lowered testosterone, delayed-onset puberty, and possible causal effects such as oxidative stress and altered gene expression. Still, limited data exists on combinations of environmental pollutants and pharmaceuticals with ED potential at human-relevant doses. This review of the recent literature aims to synthesize the toxicological impact of low dose chemical mixtures on male reproductive health. Overall, humans are exposed to EDCs and drugs through various ways, necessitating an understanding of their concomitant effects on male reproductive health.

Particulate matter (PM) air pollution consists of liquid and solid particles, which are categorized by size as less than 10 (PM10) μm, 2.5 (PM2.5) μm, or 0.1μm (PM0.1 or ultrafine) in aerodynamic diameter and which vary in composition depending on the sources. PM exposure is ubiquitous and has been associated with many adverse health effects. This narrative review focuses on epidemiological and experimental studies that investigated the effects of PM exposure on female and male reproduction and on pregnancy.μ.

Ovulation is the process by which a fertilizable oocyte is extruded from the interior of the follicle. Herein, we conducted a literature survey to explore the ovulation patterns of eleven sexually reproducing species belonging to 10 animal phyla. These results indicate a large variety of ovulation patterns. Further comparative biological and evolutionary considerations of these results led us to conclude that most female animals ovulate via follicle rupture. We propose that in all animals that ovulate by follicle rupture, two cellular events may be critically involved in the process: 1) the disintegration of cell junctional systems that lead to intracellular cytoskeleton rearrangement in the follicle cells and 2) the degradation of extracellular matrix (ECM) proteins filling between follicle cells. These events may result in follicular cell deformation and increased motility, both of which are necessary for the formation of a path through which oocytes escape from the follicle. In addition to the requirement of ECM degradation for disintegrating cell junctions, intensive ECM protein degradation at the apical region of the follicle probably became increasingly important in late-evolving animals, such as vertebrates, in which a thick follicle wall containing a large abundance of ECM proteins is formed. We also considered hypothetical scenarios for the evolution of ovulation in these animals. Furthermore, this article discusses the future problems that need to be solved for a more comprehensive understanding of ovulation in the animal kingdom.

Placenta-associated pathologies, including early pregnancy loss (EPL) and preeclampsia (PE), share a common phenomenon of insufficient extravillous trophoblasts (EVTs) invasion. It was previously observed that down-regulated miR-486-5p expression inhibited the invasion of EVTs, and a decreased peripheral miR-486-5p was associated with EPL. However, the exact roles of miR-486-5p played in pathogenesis of EPL, as well as the molecular pathway underlying roles of miR-486-5p in EVTs invasion, remains poorly understood. In this study, a decreased miR-486-5p expression in uterine embryo implantation site at gestation day (GD) 8.5, and an increased expression of Smad2, a target of miR-486-5p, were observed in the lipopolysaccharide (LPS)-induced EPL mouse model. The invasion and viability of immortalized human EVTs line, HTR-8/SVneo, were inhibited by LPS, accompanied with a reduced miR-486-5p expression. LPS showed a promoting effect on the Smad2 expression, of which could be attenuated by miR-486-5p mimics. And the down-regulated Smad2 could effectively restore the impaired invasion and viability of HTR-8/SVneo cells caused by LPS or miR-486-5p inhibitor. Furthermore, LPS could promote the TNFα production in HTR-8/SVneo cells, whereas both of siSmad and miR-486-5p mimics could reverse such an effect. By analyzing the human decidua single-cell RNA sequencing and transcriptome datasets derived from the Gene Expression Omnibus, it was found that, compared to control early pregnant women, the Smad2 expression was significantly increased in recurrent miscarriages (RM) patients. Collectively, these data suggested that, decreased miR-486-5p expression might lead to EPL at least partially by inhibiting invasion and/or promoting TNFα production of EVTs via targeting Smad2.

Years of growing research demonstrate that transgender and gender diverse (TGD) people desire fertility counseling and family building, however social and medical factors can impact future fertility options. Fortunately, TGD individuals have many viable options for family building using their own gametes and/or reproductive organs. However, the nuanced ways in which different gender affirming treatments affect reproduction, the interplay with non-treatment related infertility factors, and mitigation of likely dysphoria triggers are all critical to actual utilization. This review focuses on fertility treatment and preservation options for TGD patients and highlights these influential social and medical factors. Fertility treatments may be associated with worsening gender dysphoria in TGD people, and an affirming clinical environment and conscientious provider approach is paramount to treatment success. However, reducing gender dysphoria can also require specific changes to medically assisted reproduction and sperm collection protocols, some which carry the potential for diminished outcomes or unknown effects. Adolescents undergoing fertility preservation treatments may need more support or additional protocol modifications, and outcomes may be poorer in this age group compared with adults. Testicular and ovarian tissue cryopreservation may present a fertility preservation option for prepubertal TGD children, however in-vitro gamete maturation remains experimental in this situation.

The histone variant TH2B, enriched in oocytes, sperm, and early embryos, decreases as embryos differentiate into pre-gastrula stages. Despite its presence, the role of TH2B in epigenetic reprogramming during early embryonic development remains largely under-researched. Our study employed ultra-low-input ChIP-seq (ULI-ChIP) to analyze the genome-wide distribution of TH2B in MII oocytes and early embryos. We found that TH2B is enriched in the chromatin of oocytes and 2-cell stage embryos but becomes less prevalent after the 2-cell stage. Correlation analysis revealed that the TH2B chromatin patterns in sperm and preimplantation embryos are more similar to each other than to those in MII oocytes. Gene ontology (GO) analysis of TH2B-occupied loci linked them to various developmental processes, including oogenesis, fertilization, chromatin modification, and transcription regulation. The study also identified a strong association of TH2B with specific transposable elements (TEs), particularly long terminal repeats (LTRs), which are known to regulate preimplantation development. Additionally, early embryos showed H3K9me3 marks at TH2B-bound loci. TH2B exhibited strong correlations with H2A.Z and H3.3 in the 2-cell and 8-cell stages, a positive association with H3K27Ac and H3K4me3, and a negative correlation with H3K27me3. Allelic reprogramming analysis of TH2B in embryos from C57BL/6J and DBA/2J crosses revealed differential dynamics between maternal and paternal alleles, with a notable paternal bias at the promoter in 2-cell embryos. Thus, TH2B's enrichment in early embryonic stages and its association with key regulatory regions and histone modifications underscore its importance in ZGA and subsequent developmental processes.

Brain-derived neurotrophic factor (BDNF) is a peptide widely known for its role in neurogenesis and synaptic plasticity. Its expression in non-neuronal tissues has been reported. In mammals, it is involved in ovarian development, follicle growth, oocyte maturation, and early embryonic development. In zebrafish, it was demonstrated that BDNF increases food intake and regulates metabolism. Reproduction and metabolism are tightly linked. We hypothesized that BDNF modulates reproductive hormones and reproductive functions in zebrafish. This study aimed to determine BDNF expression in the zebrafish reproductive axis and whether it modulates the reproductive endocrine milieu and oocyte biology in zebrafish. Our results show that bdnf and its receptor trkb, and BDNF-like immunoreactivity are detected in zebrafish gonads and liver cells. This suggests BDNF local production and possible actions within the gonads and liver. Intraperitoneal administration of 1, 10, or 100 ng/g bodyweight BDNF significantly (ANOVA, p<0.05) increased sgnrh/cgnrh-II, kiss1, and cyp19a1b mRNAs in the zebrafish brain; steroidogenic enzymes (star and cyp19a1a) and key receptors in the zebrafish gonads. In vitro incubation of zebrafish liver cells with BDNF significantly (ANOVA, p<0.05) increased estrogen receptor mRNAs and vitellogenin concentrations (ELISA) in the cells. BDNF (100 ng/mL) induced (ANOVA, p<0.05) oocyte maturation in vitro at 24 hours post-incubation and significantly upregulated cumulus-expansion related genes (ANOVA, p<0.05). Overall, our findings indicate a stimulatory role for BDNF in the reproductive axis of zebrafish. This provides impetus for future research on its mechanism of action and potential practical applications to enhance reproduction in aquaculture.