Search

Throughout the individual’s reproductive period of life the ovary undergoes continues changes, including cyclic processes of cell death, tissue regeneration, proliferation, and vascularization. Tissue-resident leucocytes particularly macrophages, play a crucial role in shaping ovarian function and maintaining homeostasis. Macrophages crucially promote angiogenesis in the follicles and corpora lutea, thereby supporting steroidogenesis. Recent research on macrophage origins and early tissue seeding has unveiled significant insights into their role in early organogenesis, e.g. in the testis. Here, we review evidence about the prenatal ovarian seeding of leucocytes, primarily macrophages with angiogenic profiles, and its connection to gametogenesis. In the prenatal ovary, germ cells proliferate, form cysts, and undergo changes that, following waves of apoptosis, give rice to the oocytes contained in primordial follicles. These follicles constitute the ovarian reserve that lasts throughout the female’s reproductive life. Simultaneously, yolk-sac-derived primitive macrophages colonizing the early ovary are gradually replaced or outnumbered by monocyte-derived fetal macrophages. However, the cues indicating how macrophage colonization and follicle assembly are related are elusive. Macrophages may contribute to organogenesis by promoting early vasculogenesis. Whether macrophages contribute to ovarian lymphangiogenesis or innervation is still unknown. Ovarian organogenesis and gametogenesis are vulnerable to prenatal insults, potentially programming dysfunction in later life, as observed in polycystic ovary syndrome. Experimental and, more sparsely, epidemiological evidence suggest that adverse stimuli during pregnancy can program defective folliculogenesis or a diminished follicle reserve in the offspring. While the ovary is highly sensitive to inflammation, the involvement of local immune responses in programming ovarian health and disease remains to be thoroughly investigated. [ABSTRACT FROM AUTHOR]

Ovarian aging is associated with depletion of the ovarian follicle reserve, which is the key determinant of fertility potential in females. In this study, we found that the small, secreted protein complement 1Q-like (C1QL1) is involved in the regulation of follicle depletion through intraovarian and endocrine control in a multidimensional collaborative manner. C1ql1 was detected to be conserved in the ovary and showed high transcript levels during folliculogenesis. Blockade of C1QL1 by IP and ovarian intrabursal injection of C1QL1 antiserum into prepubertal mice impaired folliculogenesis accompanied by reductions in body weight, fat mass, and intraovarian lipid accumulation. An elevation of circulating estradiol levels, reduction of hypothalamic KISS1 and GnRH expression, and a decrease in serum FSH levels were found in C1QL1-deficient mice. In C1QL1-deficient ovaries, many primordial follicles were recruited and developed into medium follicles but underwent atresia at the large follicle stages, which resulted in depletion of follicle reserve. Depletion of C1QL1 alleviated the inhibitory effect of C1QL1 on granulosa cell apoptosis and the stimulatory effect of C1QL1 on granulosa cell autophagy, which resulted in accumulation in the preantral and early antral follicles and an increase in the atretic follicles. The abnormal profile of endocrine hormones accelerated the intraovarian effect of C1QL1 deficiency and further led to depletion of ovarian reserve. Altogether, this study revealed the expression patterns and the mechanism of action of C1QL1 during folliculogenesis and demonstrated that deficiency of C1QL1 caused ovarian follicular depletion. [ABSTRACT FROM AUTHOR]

Mammalian females are born with a finite reserve of ovarian follicles, the functional units of the ovary. Building an ovarian follicle involves a complex interaction between multiple cell types, of which the oocyte germ cell and the somatic granulosa cells play a major role. Germ–somatic cell interactions are modulated by factors of different cell origins that influence ovarian development. In early development, failure in correct germ–somatic cell communication can cause abnormalities in ovarian development. These abnormalities can lead to deficient oocyte differentiation, to a diminished ovarian follicle reserve, and consequently to early loss of fertility. However, oocyte–granulosa cell communication is also extremely important for the acquisition of oocyte competence until ovulation. In this paper, we will visit the establishment of follicle reserve, with particular emphasis in germ–somatic cell interactions, and their importance for human fertility.

Abstract Background A low oxygen supply to the fetus causes intrauterine growth restriction and can affect gonadal development of the offspring, having a potential impact on fertility. We investigated histology and gene expression in the postnatal rat ovary after fetal hypoxia induced by uterine artery ligation. Methods Sprague-Dawley rats underwent uterine artery ligation at day 19 of gestation. Offspring were sacrificed at 5, 20 and 40 days post-partum. Follicles were counted and classified in hematoxylin-eosin stained sections. Gene expression of 90 genes was analyzed by TaqMan® Low Density Array. Results A significantly lower number of total and primordial follicles was detected in 20 days post-partum intrauterine growth restricted animals. Follicle density was not different at 40 days post-partum, suggesting that compensatory mechanisms occurred during the pre-pubertal window. Uterine artery ligation modified the expression of 24 genes involved in different cellular functions, among which proliferation, apoptosis and metabolism. Conclusion Ovarian follicle pool was affected by fetal hypoxia in early life, but this effect did not persist in puberty. Genes involved in cellular processes were affected at all ages, potentially implying long-term genetic alterations. Further analyses are needed to elucidate later effects of fetal hypoxia on ovarian function and fertility.

Background Methotrexate (MTX) is an agent used in the treatment of many neoplastic and non-neoplastic diseases and is known to cause oxidative damage in normal tissues. Curcumin (Cur) is a natural polyphenol compound with powerful antioxidant and antiapoptotic effects. In this study we investigate the effects of Cur on MTX-induced ovarian damage.Materials and methods Thirty-two young adult female Wistar albino rats were divided into four groups: (1) Control (n = 8): only vehicle group, (2) Cur (n = 8): Cur-only group (200 mg/kg/day), (3) MTX (n = 8): MTX-only group (0.35 mg/kg/day), (4) MTX+Cur (n = 8): The group was given MTX (0.35 mg/kg/day) and Cur (200 mg/kg/day) for 28 days. Then, SOD, CAT, MDA, AMH levels were measured using ELISA kits. Follicle count was performed on H&E stained slides. In addition, the expressions of P53 and PARP-1 were analysed by immunohistochemistry.Results MDA levels were seen to be higher in the MTX group than in the MTX+Cur group (p

Management of ovarian endometrioma is a matter of debate between those advocating early treatment and those believing that cysts less than 3 cm in diameter should not be submitted to surgery. To explore a new approach to its management capable of preserving future fertility, the molecular pathology of ovarian endometrioma is reviewed and mechanisms by which the endometrioma progressively affects the ovary during reproductive life are summarized. The scope of new therapeutic modalities includes restoring the progesterone receptor ratio using progestin or progesterone receptor modulators and decreasing local oestrogen production through an aromatase inhibitor. In addition, free radical production can be blocked by antioxidants and the autophagic process by increasing apoptosis. Finally, metalloproteinases and relaxin activity, as well as the inflammatory process can be controlled. Many of these pharmacological treatments lend themselves to local administration and can be applied through intracystic drug administration; in fact, the intracystic route has already been tried with recombinant interleukin-2, methotrexate and ethanol; the latter to obtain sclerotization. Specifically, it is proposed that endometrial growth in the endometrioma is suppressed by intra-cystic application of synthetic progestins, such as levonorgestrel or danazol, selective progesterone receptor modulators, such as mifepristone, ulipristal or asoprisnil, without affecting ovarian activity. [ABSTRACT FROM AUTHOR]

Study Question: Is there any in vitro evidence for or against ovarian protection by co-administration of a GnRH agonist with chemotherapy in human?Summary Answer: The co-administration of GnRH agonist leuprolide acetate with cytotoxic chemotherapy agents does not preserve ovarian reserve in vitro.What Is Known Already: Randomized controlled trials of the co-administration of gonadotrophin-releasing hormone (GnRH) agonists with adjuvant chemotherapy to preserve ovarian function have shown contradictory results. This fact, together with the lack of a proven molecular mechanism of action for ovarian protection with GnRH agonist (GnRHa) places this approach as a fertility preservation strategy under scrutiny. We therefore aimed in this study to provide in vitro evidence for or against the role of GnRHa in the prevention of chemotherapy-induced damage in human ovary.Study Design, Settings, Size and Duration: This translational research study of ex vivo and in vitro models of human ovary and granulosa cells was conducted in a university hospital between 2013 and 2015.Participants/materials, Setting, Methods: Ovarian cortical pieces (n = 15, age 14-37) and mitotic non-luteinized (COV434 and HGrC1) and non-mitotic luteinized human granulosa cells (HLGC) expressing GnRH receptor were used for the experiments. The samples were treated with cyclophosphamide, cisplatin, paclitaxel, 5-FU, or TAC combination regimen (docetaxel, adriamycin and cyclophosphamide) with and without GnRHa leuprolide acetate for 24 h. DNA damage, apoptosis, follicle reserve, hormone markers of ovarian function and reserve (estradiol (E2), progesterone (P) and anti-mullerian hormone (AMH)) and the expression of anti-apoptotic genes (bcl-2, bcl-xL, bcl-2L2, Mcl-1, BIRC-2 and XIAP) were compared among control, chemotherapy and chemotherapy + GnRHa groups.Main Results and the Role Of Chance: The greatest magnitude of cytotoxicity was observed in the samples treated with cyclophosphamide, cisplatin and TAC regimen. Exposure to these drugs resulted in DNA damage, apoptosis and massive follicle loss along with a concurrent decline in the steroidogenic activity of the samples. GnRHa co-administered with chemotherapy agents stimulated its receptors and raised intracellular cAMP levels. But it neither activated anti-apoptotic pathways nor prevented follicle loss, DNA damage and apoptosis induced by these drugs.Limitations, Reasons For Caution: Our findings do not conclusively rule out the possibility that GnRHa may offer protection, if any, through some other mechanisms in vivo.Wider Implications Of the Findings: GnRH agonist treatment with chemotherapy does not prevent or ameliorate ovarian damage and follicle loss in vitro. These data can be useful when consulting a young patient who may wish to receive GnRH treatment with chemotherapy to protect her ovaries from chemotherapy-induced damage. [ABSTRACT FROM AUTHOR]

Abstract: Background: Data on the distribution of primordial (single layer of squamous granulosa cells), early primary (some granulosa cells cuboidal) and primary (all granulosa cells cuboidal) follicles, grouped together as small follicles (SF) within the ovary of the elephant is lacking, yet such information is necessary to be able to estimate accurately the total numbers of small follicles in the ovaries of elephant throughout their lifespan. Aim: To determine if the density of SF differs between ovaries, between the surfaces of an ovary, or between the interpolar and intermarginal zones of an ovary. Materials/methods: Stereological techniques were employed on 25μm thick histological sections of the ovaries recovered from 12 prepubertal elephant calves aged 2 months to 4.5 years. Cell densities were calculated using the optical brick method and Cavalieri''s principle for volume calculation. Results: The density of SF (numbers of SF per unbiased counting frame [UCF]) did not differ between the left (1.11±0.39 (mean±sd)) and right (1.10±0.39) ovaries (P =0.82, n =12), or between the lateral (median 1.24; interquartile range 0.85–1.39) and medial (1.03; 0.76–1.36) surfaces of the ovary (P =0.22, n =24) or among the 5 segments of the ovary between the two poles (P =0.20, n =24). The third of the cortex nearest to the mesovarial margin of the ovary had fewer small follicles per UCF (0.85; 0.51–1.28) than the middle third (1.01; 0.78–1.42; P =0.034), and the third adjacent to the free margin (1.27; 0.79–1.51; P =0.0024), n =24 per group. Conclusion: Providing a random sample is taken from the full interpolar and intermarginal dimensions of ovary of a non-pregnant elephant, the density of small follicles throughout the cortex may be accurately measured using stereological techniques applied to one of its surfaces. [Copyright &y& Elsevier]

Background: A low oxygen supply to the fetus causes intrauterine growth restriction and can affect gonadal development of the offspring, having a potential impact on fertility. We investigated histology and gene expression in the postnatal rat ovary after fetal hypoxia induced by uterine artery ligation. Methods: Sprague-Dawley rats underwent uterine artery ligation at day 19 of gestation. Offspring were sacrificed at 5, 20 and 40 days post-partum. Follicles were counted and classified in hematoxylin-eosin stained sections. Gene expression of 90 genes was analyzed by TaqMan® Low Density Array. Results: A significantly lower number of total and primordial follicles was detected in 20 days post-partum intrauterine growth restricted animals. Follicle density was not different at 40 days post-partum, suggesting that compensatory mechanisms occurred during the pre-pubertal window. Uterine artery ligation modified the expression of 24 genes involved in different cellular functions, among which proliferation, apoptosis and metabolism. Conclusion: Ovarian follicle pool was affected by fetal hypoxia in early life, but this effect did not persist in puberty. Genes involved in cellular processes were affected at all ages, potentially implying long-term genetic alterations. Further analyses are needed to elucidate later effects of fetal hypoxia on ovarian function and fertility. [ABSTRACT FROM AUTHOR]