Reproduction最新文献

In brief: Early pregnancy loss (EPL) is a common pregnancy problem lacking preventive measures. This study shows that DMOG-preconditioned hUC-MSCs can reduce early embryo loss.

Abstract: EPL, a common pregnancy complication, yet has few effective preventive measures currently. To investigate whether dimethyloxaloylglycine (DMOG)-preconditioned human umbilical cord mesenchymal stem cells (hUC-MSCs) can prevent EPL, we initially evaluated the effect of DMOG on hUC-MSCs in vitro. Subsequently, the DMOG-preconditioned hUC-MSCs were transplanted into the lipopolysaccharide (LPS)-induced murine abortion model for intervention, following which we conducted phenotypic analysis. It was found that DMOG treatment enhanced the mRNA expression of HIF1A, H19 and GLUT1 in hUC-MSCs and augmented their migration capability (P < 0.01). Co-culture experiments showed that DMOG-treated hUC-MSCs notably reduced the mRNA levels of IL6, IL1B and TNFA in LPS-induced HTR-8/SVneo cells (P < 0.01). Moreover, DMOG-preconditioned hUC-MSCs remarkably decreased the fetal resorption rate and increased the embryo weight in LPS-induced abortive mice (P < 0.01). Histological analysis indicated that DMOG-preconditioned hUC-MSCs more effectively promoted their homing and inhibited LPS-induced fibrosis at the maternal-fetal interface. Apart from suppressing inflammatory factors in the serum of pregnant mice, DMOG-preconditioned hUC-MSCs can downregulate the mRNA levels of Il2, Il1b, Tnfa, Il5 and Il9 (P < 0.01), which are pro-inflammatory cytokines secreted by M1 macrophages; and simultaneously upregulate the expression of Cd206 and Pparg (P < 0.01), which serve as the cell surface and nuclear receptors of M2 macrophages in the embryos. Immunofluorescence further verified that the transplantation of DMOG-preconditioned hUC-MSCs could increase the expression of CD206 in embryos. Therefore, DMOG-preconditioned hUC-MSCs might prevent EPL by promoting the transformation of M1 into M2 macrophages.

In brief: Oocytes with subtle differences in chromatin configuration and nuclear lamina characteristics, detectable by a refined germinal vesicle (GV) classification system here described, respond differently to meiotic maturation systems leading to different in vitro maturation (IVM) outcomes.

Abstract: The nuclear, cytoplasmic and molecular maturation of the mammalian oocyte is a finely orchestrated sequence of events that relies on proper cumulus-oocyte communication. Bovine oocytes enter the IVM systems at the GV stage exhibiting four different chromatin configurations (GV0-GV3). Herein, we associate the oocyte chromatin and nuclear lamina configurations to propose a refined GV classification (GV0, GV1.1-GV1.3, GV2.1-GV2.3 and GV3.1-GV3.3). This refined GV classification system was correlated with oocyte meiosis resumption and transzonal projections (TZPs) density of cumulus-oocyte complexes (COCs) submitted to three IVM systems (control IVM and a modified IVM preceded or not by a pre-IVM step). Pre-IVM resulted in lower polar body extrusion rates at 19 h IVM, albeit ∼24% of the oocytes extruded their first polar body at 9 h IVM. Pre-IVM sustained 80% of oocytes meiotically arrested but altered GV distribution, reducing GV2 and increasing GV1.3 and GV3.3 categories. Pre-IVM reduced TZP densities predominantly in pre-matured GV3 and GVBD COCs. At 9 h of IVM, both groups matured in modified IVM showed lower TZP densities compared to immature and IVM control. Gene expression supports the TZP density differences, with ERK2 and PRKACA upregulation in pre-matured cumulus and in modified IVM groups at 9 h of IVM. GDF9 and BMP15 levels were similar between treated and control groups at all time points. Our findings indicate that despite the IVM system, the initial oocyte GV stage influences pre-IVM and IVM outcomes. The refined GV classification system is a useful tool to oocyte biologists.

In brief: The transition from histones to protamines during spermiogenesis is critical for male genome integrity and influences fertilisation and early embryogenesis. This study reveals that specific 5' UTR single nucleotide polymorphisms (SNPs) and promoter methylation of the H2BC1 gene may regulate TSH2B expression in sperm, contributing new insights into the regulatory mechanisms of testis-specific genes and their implications for male fertility.

Abstract: The transition from histones to protamines during spermiogenesis plays a crucial role in shaping the male epigenome, and any changes in this process can impact fertilisation potential and the ability of sperm to support early embryogenesis. In our previous research, we observed reduced levels of TSH2B in the sperm of infertile men with oligozoospermia and oligoasthenozoospermia. However, the regulatory mechanisms of the H2BC1 gene, which encodes TSH2B, in the testes are not yet understood. In this study, we investigated whether H2BC1 expression is influenced by SNPs in the 5' untranslated region (5' UTR) and promoter methylation. Luciferase assays were performed to assess the impact of 5' UTR variants in vitro and pyrosequencing was done to evaluate promoter methylation of the H2BC1 gene in the sperm of fertile and infertile men. Our findings suggest that the 5' UTR variants rs4711096 (c.-83A>G) and rs4712959 (c.-80C>T) positively regulate H2BC1 expression. Methylation analysis indicates hypermethylation of CpG sites, particularly at CpGs 2, 3 and 9 in H2BC1, can influence H2BC1 expression. This study offers new insights into the regulation of testis-specific genes.

In brief: This review article summarizes the effects of pre- or peri-conceptual exposure to cannabinoids on female and male reproductive function, along with pregnancy outcomes from 2014 to 2024. In particular, it addresses the gaps in knowledge regarding the specific contributions of the major constituents of cannabis, THC and CBD, on reproduction.

Abstract: With increased use of cannabis worldwide, especially in our young adult population, there is a great impetus to understand the impact of cannabis and its constituents (i.e. THC and CBD) on pregnancy, fetal outcomes and male and female reproductive function. This review assessed the current evidence (2014-2024) regarding the effects of cannabinoids on reproductive function (male, female and pregnancy) in animal and human studies. In particular, pre- or periconceptual exposure to cannabinoids were assessed to determine their effects across the lifespan along with transgenerational effects. From the outcomes of this review, we conclude there is a greater need for future preclinical and clinical studies to assess how various routes of cannabinoid exposure along with differing mixtures of cannabinoid constituents may interact to impede reproductive health. Collectively, the outcomes of these studies are important to clinicians and regulatory agencies in the context of functional evidence to support policy and decision-making regarding the safety of cannabis use.

We synthesize current evidence that granulosa cells possess unique innate immune signaling capabilities. We suggest the novel concept that this serves as a quality control surveillance mechanism by integrating signals from the oocyte and ovarian microenvironment to prevent poor-quality follicles from producing gametes that contribute to the next generation.

In brief: The role of inflammation in the regulation of pregnancy remains poorly understood in dogs. Findings from this study propose the involvement of IL1β signaling during early embryo-maternal interactions in the dog, while in vitro effects suggest it may disrupt decidual cell function in the canine mature placenta.

Abstract: Although implantation and parturition are associated with pro-inflammatory signals, inflammatory responses in the mature placenta frequently lead to pregnancy loss. Indeed, uterine inflammatory/infectious diseases are major causes of infertility and pregnancy loss in dogs. The pro-inflammatory interleukin (IL)-1β is increased during canine placentation and downregulated in mature placentae during healthy pregnancies but is enriched in the placenta during infectious events. Furthermore, canine pregnancy success is linked with decidual cells, the only placental cells expressing the nuclear progesterone receptor. This study assessed utero-placental abundance of IL1β receptor 1 (IL1R1) throughout canine pregnancy and possible modulatory effects of IL1β on decidualization. The mRNA levels of IL1R1 were increased in mature mid-gestation placentae and at term (P < 0.05). Immunohistochemistry co-localized IL1β and IL1R1 in the trophoblast during early placentation, implicating IL1β-signaling in early embryo-maternal communication. In the mature placenta, IL1R1 was localized, i.a. in decidual cells. In vitro, IL1β had low modulatory effects on PGE2- and/or P4-stimulated dog uterine stromal (DUS) cells, implying a relatively weak impact of this interleukin in the decidualization process. However, in DUS cells decidualized with cAMP, IL1β decreased transcriptional amounts of selected decidualization markers IGF1, PTGS2 and PTGES, as well as ECM1 and TIMP2 (P < 0.001). Transcriptional and protein availabilities of CX43, a gap junction component, were also decreased by IL1β (P < 0.001). These findings support a dual role for IL1β in canine pregnancy: involvement in early embryo-maternal communication during its establishment and disturbing placental homeostasis by disrupting decidual cell function in fully developed placenta.

In brief: Severely deficient levels of vitamin D (VD) affect ovarian cellular function reducing production of androstenedione and oestradiol and insulin receptor expression; although mildly deficient levels have no effect.

Abstract: Numerous studies have investigated the link between VD deficiency and reproductive outcomes with contradictory results. VD regulates steroidogenic enzymes crucial for human granulosa and cumulus cell function. This study investigated whether deficient levels of 1,25-(OH)2-D3 altered ovarian cell function, and if the ovary could obtain bioactive 1,25-(OH)2-D3 via local enzymatic expression of CYP27B1 to counteract systemic deficiency. A variety of cells and tissues were used for the in vitro experiments. We have shown for the first time an increase in VDR expression in theca of large compared to small follicles, which along with the ability of 1,25-(OH)2-D3 to decrease anti-Müllerian hormone expression, supports a role for 1,25-(OH)2-D3 in theca and granulosa cell function. Conversely, very low levels of 1,25-(OH)2-D3 equivalent to hypovitaminosis inhibited thecal production of androstenedione and cAMP-driven oestradiol production. Human thecal and un-luteinised GC are incredibly hard to obtain for research purposes, highlighting the uniqueness of our dataset. We also demonstrated that deficient levels of 1,25-(OH)2-D3 downregulated insulin receptor expression, potentially reducing insulin sensitivity. We have shown that the ovary expresses CYP27B1, potentially allowing it to make local bioactive 1,25-(OH)2-D3, which along with the upregulation in VDR expression in ovarian cellular compartments could be protective locally in counteracting systemic VD deficiency. To conclude, a severely deficient VD environment (<2 nM or <1 ng/mL) could contribute to impaired ovarian cell function, and hence, potentially affect folliculogenesis/ovulation, but levels associated with mild deficiency may have less impact, apart from in the presence of hyperinsulinaemia and insulin resistance.

In brief: Polycystic ovary syndrome has ancient genetic origins that favored preferential abdominal fat accumulation, ovarian hyperandrogenism and insulin resistance. This review examines how endocrine-metabolic changes in normal-weight hyperandrogenic PCOS women originated as an evolutionary metabolic adaptation to balance enhanced fat storage with increased glucose and fatty acid availability for optimal energy use for survival and reproduction.

Abstract: Polycystic ovary syndrome (PCOS) is a common endocrinopathy of reproductive-aged women, characterized by hyperandrogenism, oligo-anovulation and insulin resistance in combination with preferential abdominal fat accumulation. As an ancestral primate trait, PCOS in humans likely underwent relatively recent preferential selection when scarcity of food in hunter-gatherers of the Pleistocene selected for enhanced fat storage and insulin resistance as a survival advantage to maintain glucose homeostasis for brain and reproductive function. As an evolutional model for PCOS, healthy normal-weight women with hyperandrogenic PCOS have subcutaneous (SC) abdominal adipose stem cells that favor exaggerated lipid accumulation during adipocyte development in vitro accompanied by reduced systemic insulin sensitivity and preferential accumulation of highly lipolytic intra-abdominal fat. Programmed by genetic inheritance and epigenetic events during early life, such a metabolic adaptation in PCOS, provides a balance between enhanced SC adipose fat storage and increased circulating glucose and free fatty acid availability as energy substrate for crucial target tissues. The accompanying increased muscle strength and oligo-anovulation in PCOS women of antiquity also enabled sustained energy use during endurance activities in combination with greater time as a rearing advantage for children and a lower risk of maternal mortality. Heritable PCOS characteristics that originally evolved in primates as a genetically and epigenetically enhanced metabolic adaptation to favor fat storage now predispose to lipotoxicity and pregnancy complications, calling for improved preventive healthcare, with early lifestyle and therapeutic choices to optimize the long-term health of PCOS women and their children in today's obesogenic environment.

In brief: Irisin is a muscle and adipose-derived hormone that is secreted in response to negative energy balance in cattle. We show here that irisin reduced follicle growth and theca cell function.

Abstract: At the onset of lactation, dairy cattle are anestrous owing mainly to a state of negative energy balance. Adipose tissue is mobilized to meet the energy demands of milk production, and this alters the secretion of adipose-derived hormones, called adipokines. Irisin is a myokine/adipokine that may play a role in fertility; plasma concentrations increase in cattle postpartum, and irisin decreased progesterone and estradiol secretion from bovine granulosa cells in vitro. To our knowledge, the effects of irisin on bovine theca cell function in vitro and on follicle growth in vivo have not been reported. We hypothesized that irisin negatively affects theca cell function in vitro and causes follicle regression in vivo using well-established bovine models. Under physiological concentrations of insulin (0.2 ng/mL), irisin did not affect glucose uptake, but decreased testosterone secretion and stimulated PTK2 and MTOR phosphorylation. Inhibiting PTK2 activity abolished the ability of irisin to decrease testosterone secretion. Injection of irisin directly into a growing follicle in vivo caused follicle regression. We conclude that irisin decreases bovine theca cell steroidogenesis through PTK2 signaling, and combined effects on theca and granulosa cells cause follicle regression.

In brief: Progesterone supplementation reverses 83% of transcript changes in the secretory endometrium induced by postovulatory mifepristone, potentially mitigating its antiprogestogenic effects.

Abstract: Mifepristone (RU486) antagonizes progesterone signaling in human endometrium interfering in the secretory phenotype after estradiol priming. The objective of the present study was to determine effect in the endometrial transcript profile of progesterone supplementation after the administration of 200 mg of the antiprogestin mifepristone 48 h after the LH peak (LH+2, LH+0 = LH peak). Endometrial samples were obtained on LH+7 after vaginal administration of micronized progesterone 200 mg/day for 3 days in nine women of proven fertility, each one contributing with one cycle treated with progesterone and another with a placebo. In addition, endometrial samples were obtained in LH+7 from a subgroup of four women with no administration of mifepristone, with each one contributing with one cycle treated with vaginal progesterone supplementation or placebo as a reference. RNA-seq was used to identify transcripts significantly regulated under the administration of progesterone vs placebo with or without postovulatory mifepristone. We observed that 713 transcripts changed significantly in the endometrium under mifepristone after progesterone supplementation in group A. Of these, progesterone reversed approximately 83% of the transcripts affected by mifepristone in the secretory endometrium. Bioinformatic analyses revealed that these transcripts were enriched in genes associated with mitochondrial function, particularly oxidative phosphorylation. In addition, NR2C2 and DLX1 were identified as potential transcription factors that may mediate the effects of progesterone in the endometrium. We conclude that progesterone supplementation after postovulatory mifepristone administration can reverse the antiprogestogenic effects for most of the affected endometrial transcripts.