Reproduction最新文献

Over the past 50 years, there has been a concerning decline in male reproductive health and an increase in male infertility which is now recognised as a major health concern globally. While male infertility can be linked to some genetic and lifestyle factors, these do not fully explain the rate of declining male reproductive health. Increasing evidence from human and animal studies suggests that exposure to chemicals found ubiquitously in the environment may in part play a role. Many studies on chemical exposure, however, have assessed the effects of exposure to individual environmental chemicals (ECs), usually at levels not relevant to everyday human exposure. There is a need for study models which reflect the 'real-life' nature of EC exposure. One such model is the biosolids-treated pasture (BTP) sheep model which utilises biosolids application to agricultural land to examine the effects of exposure to low-level mixtures of chemicals. Biosolids are the by-product of the treatment of wastewater from industrial and domestic sources and so their composition is reflective of the ECs to which humans are exposed. Over the last 20 years, the BTP sheep model has published multiple effects on offspring physiology including consistent effects on the male reproductive system in fetal, neonatal, juvenile, and adult offspring. This review focuses on the evidence from these studies which strongly suggests that low-level EC exposure during gestation can alter several components of the male reproductive system and highlights the BTP model as a more relevant model to study real-life EC exposure effects.

In brief: Abnormal glucose metabolism may be involved in the pathogenesis of endometriosis. The present study identifies that highly expressed H19 leads to increased aerobic glycolysis and histone lactylation levels in endometriosis.

Abstract: Previous studies from our group and others have shown increased IncRNA H19 expression in both the eutopic endometrium and the ectopic endometriosis tissue during endometriosis. In this study, we use immunofluorescence, immunohistochemistry, and protein quantification to determine that levels of aerobic glycolysis and histone lactylation are increased in endometriosis tissues. In human endometrial stromal cells, we found that high H19 expression resulted in abnormal glucose metabolism by examining the levels of glucose, lactate, and ATP and measuring protein levels of enzymes that participate in glycolysis. At the same time, immunofluorescence and western blotting demonstrated increased histone lactylation in H19 overexpressing cells. Altering aerobic glycolysis and histone lactylation levels through the addition of sodium lactate and 2-deoxy-d-glucose demonstrated that increased aerobic glycolysis and histone lactylation levels resulted in enhanced cell proliferation and cell migration, contributing to endometriosis. To validate these findings in vivo, we constructed an endometriosis mouse model, demonstrating similar changes in endometriosis tissues in vivo. Both aerobic glycolysis and histone lactylation levels were elevated in endometriotic lesions. Taken together, these data demonstrate elevated expression levels of H19 in endometriosis patients promote abnormal glucose metabolism and elevated histone lactylation levels in vivo, enhancing cell proliferation and migration and promoting the progression of endometriosis. Our study provides a functional link between H19 expression and histone lactylation and glucose metabolism in endometriosis, providing new insights into disease mechanisms that could result in novel therapeutic approaches.

In brief: Atrazine, like oestrogen, disorganises laminin formation and reduces the number of germ cells and Sertoli cells in the developing testes of the tammar wallaby. This study suggests that interfering with the balance of androgen and oestrogen affects the integrity of laminin structure and testis differentiation.

Abstract: The herbicide atrazine was banned in Europe in 2003 due to its endocrine disrupting activity but remains widely used. The integrity of the laminin structure in fetal testis cords requires oestrogen signalling but overexposure to xenoestrogens in the adult can cause testicular dysgenesis. However, whether xenoestrogens affect laminin formation in developing testes has not been investigated. Here we examined the effects of atrazine in the marsupial tammar wallaby during early development and compare it with the effects of the anti-androgen flutamide, oestrogen, and the oestrogen degrader fulvestrant. The tammar, like all marsupials, gives birth to altricial young, allowing direct treatment of the developing young during the male programming window (day 20-40 post partum (pp)). Male pouch young were treated orally with atrazine (5 mg/kg), flutamide (10 mg/kg), 17β-oestradiol (2.5 mg/kg) and fulvestrant (1 mg/kg) daily from day 20 to 40 pp. Distribution of laminin, vimentin, SOX9 and DDX4, cell proliferation and mRNA expression of SRY, SOX9, AMH, and SF1 were examined in testes at day 50 post partum after the treatment. Direct exposure to atrazine, flutamide, 17β-oestradiol, and fulvestrant all disorganised laminin but had no effect on vimentin distribution in testes. Atrazine reduced the number of germ cells and Sertoli cells when examined at day 40-50 pp and day 20 to 40 pp, respectively. Both flutamide and fulvestrant reduced the number of germ cells and Sertoli cells. Atrazine also downregulated SRY expression and impaired SOX9 nuclear translocation. Our results demonstrate that atrazine can compromise normal testicular differentiation during the critical male programming window.

In brief: Ovarian aging results in reactive oxygen species accumulation and mitochondrial deterioration. During the aging process, GRSF1 deficiency attenuates mitochondrial function in aging granulosa cells.

Abstract: Ovarian aging critically influences reproductive potential, with a marked decrease in oocyte quality and quantity and an increase in oxidative stress and mitochondrial dysfunction. This study elucidates the role of guanine-rich RNA sequence binding factor 1 (GRSF1) in the aging of ovarian granulosa cells (GCs). We observed a significant reduction in GRSF1 within GCs correlating with patient age, utilizing clinical samples from IVF patients. Using an siRNA-mediated knockdown technique, we established that diminished GRSF1 expression exacerbates mitochondrial dysfunction, elevates reactive oxygen species, and impairs ATP production. Furthermore, RNA immunoprecipitation revealed GRSF1's interaction with superoxide dismutase 2 (SOD2) mRNA, a key antioxidant enzyme, suggesting a mechanism whereby GRSF1 modulates oxidative stress. Downregulation of SOD2 reversed the protective effects of GRSF1 overexpression on mitochondrial function. These insights into the role of GRSF1 in ovarian aging may guide the development of interventions to improve fertility outcomes in advanced age.

In brief: Recent reports suggest a relationship between ovarian inflammation and functional declines, although it remains unresolved if ovarian inflammation is the cause or consequence of ovarian aging. In this review, we compile the available literature in this area and point to several current knowledge gaps that should be addressed through future studies.

Abstract: Ovarian aging results in reduced fertility, disrupted endocrine signaling, and an increased burden of chronic diseases. The factors contributing to the natural decline of ovarian follicles throughout reproductive life are not fully understood. Nevertheless, local inflammation may play an important role in driving ovarian aging. Inflammation progressively rises in aged ovaries during the reproductive window, potentially affecting fertility. In addition to inflammatory markers, recent studies show an accumulation of specific immune cell populations in aging ovaries, particularly lymphocytes. Other hallmarks of the aging ovary include the formation and accumulation of multinucleated giant cells, increased collagen deposition, and increased markers of cellular senescence. Collectively, these changes significantly impact the quantity and quality of ovarian follicles and oocytes. This review explores recent literature on the alterations associated with inflammation, fibrosis, cell senescence, and the accumulation of immune cells in the aging ovary.

In brief: Brown adipose tissue impaired in polycystic ovary syndrome (PCOS) plays a crucial role in the treatment of PCOS. This study shows that myricetin potently improves PCOS by activating brown adipose tissue (BAT).

Abstract: PCOS is a complex endocrine disease characterized by hyperandrogenism, anovulation and polycystic ovary, and is often accompanied by metabolic disorder such as insulin resistance. BAT has been considered as a promising target for the treatment of obesity and other metabolic disease. In this study, we showed that 3 weeks of myricetin (a compound from natural product) treatment improved metabolic capacity and insulin sensitivity by activating BAT in dehydroepiandrosterone (DHEA)-induced PCOS mice. Furthermore, increased number of corpus luteum and decreased cystic formation were observed in PCOS mice. With the hormone levels such as luteinizing hormone (LH) were reversed, estrous cycle was also normalized after myricetin treatment. Eventually, myricetin markedly improved reproductive defects in PCOS mice. In short, our results suggest that myricetin treatment dramatically ameliorates ovarian dysfunction and metabolic disturbances in PCOS and provides a novel perspective for the treatment of PCOS.

Advanced maternal age is a major cause of infertility, miscarriage, and congenital abnormalities. This is principally caused by a decrease in oocyte quality and developmental competence with age. Oocyte ageing is characterised by an increase in chromosome missegregation and aneuploidy. However, the underlying mechanisms of age-related aneuploidy have not been fully elucidated and are still under active investigation. In addition to chromosome missegregation, oocyte ageing is also accompanied by metabolic dysfunction. In this review, we integrate old and new perspectives on oocyte ageing, chromosome segregation and metabolism in mammalian oocytes and make direct links between these processes. We consider age-related alterations to chromosome segregation machinery, including the loss of cohesion, microtubule stability and the integrity of the spindle assembly checkpoint. We focus on how metabolic dysfunction in the ageing oocyte disrupts chromosome segregation machinery to contribute to and exacerbate age-related aneuploidy. More specifically, we discuss how mitochondrial function, ATP production and the generation of free radicals are altered during ageing. We also explore recent developments in oocyte metabolic ageing, including altered redox reactions (NAD⁺ metabolism) and the interactions between oocytes and their somatic nurse cells. Throughout the review we integrate the mechanisms by which changes in oocyte metabolism influence age-related chromosome missegregation.

Background: Adult mammalian ovaries contain stem/progenitor cells necessary for folliculogenesis and ovulation-related tissue rupture repair. Theca cells are recruited and developed from progenitors during the folliculogenesis. Theca cell progenitors were not well-defined. The aim of current study is to compare the potential of four ovarian progenitors with defined markers (LY6A, EPCR, LGR5and PDGFRA) to form steroidogenic theca cells in vitro.

Methods: Ovarian progenitors were identified by the above four makers reported previously. The location of the cells was determined by immunohistochemistry and immunofluorescence staining of ovarian sections of adult mice. Different progenitor populations were purified by magnetic-activated cell sorting (MACS) and/or fluorescence-activated cell sorting (FACS) techniques from ovarian cell preparation and were tested for their abilities to generate steroidogenic theca cells in vitro. The cells were differentiated with a medium containing LH, ITS and DHH agonist for 12 days.

Results: EPCR+ and LGR5+ cells primarily distributed along ovarian surface epitheliums (OSE), while LY6A+ cells distributed in both OSE and parenchyma. However, PDGFRA+ cells were exclusively located in interstitial compartment. When the progenitors were purified by these markers and differentiated in vitro, LY6A+ and PDGFRA+ cells formed steroidogenic cells expressing both CYP11A1 and CYP17A1 and primarily producing androgens, showing characteristics of theca-like cells, while LGR5+ cells generated steroidogenic cells devoid of CYP17A1 expression and androgen production, showing a characteristic of progesterone-producing cells (granulosa- or lutea-like cells).

Conclusion: Progenitors from both OSE and parenchyma of adult mice are capable of generating steroidogenic cells with different steroidogenic capacities, showing a possible lineage preference.

In brief: In light of the increasing age of first-time fathers, this article summarizes the current scientific knowledge base on reproductive aging in the male, including sperm quality and health impacts for the offspring. The emerging role of NAD decline in reproductive aging is highlighted.

Abstract: Over the past decades, the age of first-time fathers has been steadily increasing due to socio-economic pressures. While general mechanisms of aging are subject to intensive research, male reproductive aging has remained an understudied area, and the effects of increased age on the male reproductive system are still only poorly understood, despite new insights into the potential dire consequences of advanced paternal age for the health of their progeny. There is also growing evidence that reproductive aging is linked to overall health in men, but this review mainly focuses on pathophysiological consequences of old age in men, such as low sperm count and diminished sperm genetic integrity, with an emphasis on mechanisms underlying reproductive aging. The steady decline of NAD levels observed in aging men represents one of the emerging concepts in that regard. Because it offers some mechanistic rationale explaining the effects of old age on the male reproductive system, some of the NAD-dependent functions in male reproduction are briefly outlined in this review. The overview also provides many questions that remain open about the basic science of male reproductive aging.

In brief: Adverse pregnancy outcomes in women with polycystic ovary syndrome (PCOS) are frequently associated with abnormal placental functions. This review explores the involvement of proliferator-activated receptors (PPARs) in these processes, to gain molecular insights into abnormal pregnancy conditions associated with PCOS.

Abstract: Polycystic ovary syndrome (PCOS) is one of the major endocrine disorders affecting women during their reproductive ages.Given its association with other pathologies, such as insulin resistance, metabolic syndrome, type 2 diabetes, and obesity, women with PCOS could present high-risk pregnancies, including a high abortion rate, implantation failure, an increased risk of gestational diabetes, preeclampsia, and intrauterine growth restriction. These adverse pregnancy outcomes are often attributed, at least in part, to defects in placental functions. Peroxisome proliferator-activated receptors (PPARs) are important transcription factors that participate in various placental pathways, regulating the expression of genes involved in lipid and glucose metabolism and inflammation. Furthermore, PPARs have been shown to play a role in placental development and function. Taking together this evidence, the present review focuses on the role of PPARs in placental tissue and discusses their implications in the pregnancy outcomes commonly associated with the presence of PCOS. In addition, the main treatments frequently employed have also been discussed.