Immunization with CENP-C Causes Aberrant Chromosome Segregation during Oocyte Meiosis in Mice.

Anticentromere antibodies (ACA) were associated with lower oocyte maturation rates and cleavage rates, while the mechanism was not clear. Aims of this study were to examine whether active immunization with centromere protein C could elicit the CENP-C autoantibody in mice and the impacts of the CENP-C autoantibody on oocyte meiosis. Mice were divided into two groups, one was the experimental group immunized with human centromere protein C and Freund's adjuvant (CFA), and the other was the control group injected with CFA only. Serum and oocytes of BALB/c mice immunized with human centromere protein C (CENP-C) in complete Freund's adjuvant (CFA) or injected with only CFA were studied for the development of the CENP-C antibody. Rates of germinal vesicle breakdown (GVBD), first polar body (Pb1) extrusion, abnormal spindle morphology, and chromosome misalignment were compared between the experimental group and the control group. The CENP-C antibody was only observed in serum and oocytes of mice immunized with the centromere protein C antigen. The first polar body (Pb1) extrusion rate was lower in the experimental group (P < 0.01). A higher percentage of spindle defects and chromosome congression failure were also detected in the experimental group (spindle defects: 64.67 ± 1.16% vs. 9.27 ± 2.28% control; chromosome misalignment: 50.80 ± 2.40% vs. 8.30 ± 1.16% control; P < 0.01 for both). Oocyte meiosis was severely impaired by the CENP-C antibody, which may be the main mechanism of adverse reproductive outcomes for ACA-positive women who have no clinical symptoms of any autoimmune diseases.

Exosomes: Emerging biomarkers and targets in folliculogenesis and endometriosis.

An appropriate connection of the cells in the ovary follicles is vital for a healthy ovule maturation and fertilization, and also for endometrium preparation for implantation that can cause endometriosis. Cellular communication within the follicle and endometrial epithelium involve many signaling molecules. Recent studies indicate that cellular communication can be enclosed by secretion and absorption of small membrane carriers which are named extracellular vesicles including exosomes and microvesicles. Understanding and defining these EVs (Extracellular vesicles) population are important for future studies and clinical translation. Here, we describe the various important cargos which are carried by exosomes during folliculogenesis and endometriosis. Additionally, the current knowledge of exosomes and their cargo within the FF (Follicular fluid) during the folliculogenesis and also in the intrauterine cavity which are involved in endometriosis lesions have also been summarized. Considering the potential importance of this form of the cell to cell communication in the reproductive system, the vital issues under discussion lead to a new insight in this rapidly expanding field and it may be an interesting approach for diagnostic, prognostic and especially therapeutic strategies in the field of infertility and assisted reproductive technology (ART).

An Exploration of the Impact of Anticentromere Antibody on Early-Stage Embryo.

BACKGROUND: Previously, we found women with positive anticentromere antibody showed impaired potential of oocyte maturation and embryo cleavage; the possible mechanism behind this phenomenon was still unknown. OBJECTIVE: Thus, the present study aimed to preliminarily explore whether ACA could penetrate into the living embryos and impair their developmental potential via in vitro coculture with mouse embryos. METHODS: Mouse embryos were collected and used for in vitro culture with polyclonal anticentromere protein A (CENP-A) antibody; then, immunofluorescence assay was performed to determine the penetration of antibody into embryos, and embryo development potential was observed. RESULTS: All embryos cultured with anti-CENP-A antibody exhibited immunofluorescence on the nucleus, while none of the embryos from the control groups showed immunofluorescence. Additionally, embryos cultured with anti-CENP-A antibody experienced significant growth impairment compared with controls. CONCLUSION: Mouse embryos may be a direct target for ACA in vitro prior to implantation. However, the precise mechanism needs further clarification.

Identification of immunogenic proteins from ovarian tissue and recognized in larval extracts of Rhipicephalus (Boophilus) microplus, through an immunoproteomic approach.

Rhipicephalus (Boophilus) microplus ticks are obligatory hematophagous ectoparasites of cattle and act as vectors for disease-causing microorganisms. Conventional tick control is based on the use of chemical acaricides; however, their uncontrolled use has increased tSresistant tick populations, as well as food and environmental contamination. Alternative immunological tick control has shown to be partially effective. The only anti-tick vaccine commercially available at present in the world is based on intestinal Bm86 protein, and shows a variable effectiveness depending on tick strains or geographic isolates. Therefore, there is a need to characterize new antigens in order to improve immunological protection. The aim of this work was to identify immunogenic proteins from ovarian tissue extracts of R. microplus, after cattle immunization. Results showed that ovarian proteins complexed with the adjuvant Montanide ISA 50 V generated a strong humoral response on vaccinated cattle. IgG levels peaked at fourth post-immunization week and remained high until the end of the experiment. 1D and 2D SDS-PAGE-Western blot assays with sera from immunized cattle recognized several ovarian proteins. Reactive bands were cut and analyzed by LC-MS/MS. They were identified as Vitellogenin, Vitellogenin-2 precursor and Yolk Cathepsin. Our findings along with bioinformatic analysis indicate that R. microplus has several Vitellogenin members, which are proteolytically processed to generate multiple polypeptide fragments. This apparent complexity of vitellogenic tick molecular targets gives the opportunity to explore their potential usefulness as vaccine candidates but, at the same time, imposes a challenge on the selection of the appropriate set of antigens.

Preliminary investigation of the impact of anticentromere antibody on oocyte maturation and embryo cleavage.

OBJECTIVE: To explore whether anticentromere antibody (ACA) is the most significant antibody among antinuclear antibodies (ANA), which adversely affect oocyte maturation, embryo cleavage, and pregnancy outcome in women undergoing an intracytoplasmic sperm injection program. DESIGN: Retrospective, nested case-control study. SETTING: Center for reproductive medicine, university hospital. PATIENT(S): A total of 187 women receiving the first intracytoplasmic sperm injection cycle were enrolled in this study, including 20 women with positive ACA and ANA (ACA[+]/ANA[+] group), 51 women with negative ACA and positive ANA(ACA[-]/ANA[+] group), and 116 patients with negative ACA and ANA (ACA[-]/ANA[-] group). Patients in the three groups were age-matched. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Percentages of germinal vesicle, metaphase I, and metaphase II oocytes, embryo cleavage rate, number of high-quality embryos, and rates of pregnancy and implantation. RESULT(S): The metaphase I oocyte percentage was markedly higher and the metaphase II oocyte percentage and the normal cleavage rate were significantly lower in the ACA[+]/ANA[+] group as compared with the ACA[-]/ANA[+] group. Furthermore, statistically significant differences were found in rates of pregnancy and implantation among the three groups. However, no significant difference was found between any two groups owing to the small sample size, except for a significantly lower implantation rate being found in the ACA[+]/ANA[+] group when compared with the ACA[-]/ANA[-] group. CONCLUSION(S): Our data suggest that ACA may be the essential marker for defective oocytes or embryos in infertile women with any type of ANA.

Ancestral gene and "complementary" antibody dominate early ontogeny.

According to N.K. Jerne the somatic generation of immune recognition occurs in conjunction with germ cell evolution and precedes the formation of the zygote, i.e. operates before clonal selection. We propose that it is based on interspecies inherent, ancestral forces maintaining the lineage. Murine oogenesis may be offered as a model. So in C57BL/10BL sera an anti-A reactive, mercapto-ethanol sensitive glycoprotein of up to now unknown cellular origin, but exhibiting immunoglobulin M character, presents itself "complementary" to a syngeneic epitope, which encoded by histocompatibility gene A or meanwhile accepted ancestor of the ABO gene family, arises predominantly in ovarian tissue and was detected statistically significant exclusively in polar glycolipids. Reports either on loss, pronounced expressions or de novo appearances of A-type structures in various conditions of accelerated growth like germ cell evolution, wound healing, inflammation and tumor proliferation in man and ABO related animals might show the dynamics of ancestral functions guarantying stem cell fidelity in maturation and tissue renewal processes. Procedures vice versa generating pluripotent stem cells for therapeutical reasons may indicate, that any artificially started growth should somehow pass through the germ line from the beginning, where according to growing knowledge exclusively the oocyte's genome provides a completely channeling ancestral information. In predatory animals such as the modern-day sea anemone, ancestral proteins, particularly those of the p53 gene family govern the reproduction processes, and are active up to the current mammalian female germ line. Lectins, providing the dual function of growth promotion and defense in higher plants, are suggested to represent the evolutionary precursors of the mammalian immunoglobulin M molecules, or protein moiety implying the greatest functional diversity in nature. And apart from any established mammalian genetic tree, a common vetch like Vicia cracca, may represent an ancient model of protected reproduction mirroring A-reactive "complementarity" already in a plant. The in its seeds developed, and from the number of chromosomes depending amount of an anti-A(1) specific glycoprotein suggests promotion of germination while simultaneously exerting protection from a soil bacterium, which intriguingly is immobilized by human anti-A immunoglobulin as well. Moreover, in a mammalian ovary the lectin of Dolichos biflorus detects again histo (blood) group A-determining N-acetyl-d-galactosamine epitopes, here signalizing activity of embryonic stem cells. So apparently based on identical, ancestral structures, the dual function of growth promotion and defense, predetermined in a plant genome, might be preserved right up to dominate early mammalian ontogeny.

Immunoregulation of follicular renewal, selection, POF, and menopause in vivo, vs. neo-oogenesis in vitro, POF and ovarian infertility treatment, and a clinical trial.

The immune system plays an important role in the regulation of tissue homeostasis ("tissue immune physiology"). Function of distinct tissues during adulthood, including the ovary, requires (1) Renewal from stem cells, (2) Preservation of tissue-specific cells in a proper differentiated state, which differs among distinct tissues, and (3) Regulation of tissue quantity. Such morphostasis can be executed by the tissue control system, consisting of immune system-related components, vascular pericytes, and autonomic innervation. Morphostasis is established epigenetically, during morphogenetic (developmental) immune adaptation, i.e., during the critical developmental period. Subsequently, the tissues are maintained in a state of differentiation reached during the adaptation by a "stop effect" of resident and self renewing monocyte-derived cells. The later normal tissue is programmed to emerge (e.g., late emergence of ovarian granulosa cells), the earlier its function ceases. Alteration of certain tissue differentiation during the critical developmental period causes persistent alteration of that tissue function, including premature ovarian failure (POF) and primary amenorrhea. In fetal and adult human ovaries the ovarian surface epithelium cells called ovarian stem cells (OSC) are bipotent stem cells for the formation of ovarian germ and granulosa cells. Recently termed oogonial stem cells are, in reality, not stem but already germ cells which have the ability to divide. Immune system-related cells and molecules accompany asymmetric division of OSC resulting in the emergence of secondary germ cells, symmetric division, and migration of secondary germ cells, formation of new granulosa cells and fetal and adult primordial follicles (follicular renewal), and selection and growth of primary/preantral, and dominant follicles. The number of selected follicles during each ovarian cycle is determined by autonomic innervation. Morphostasis is altered with advancing age, due to degenerative changes of the immune system. This causes cessation of oocyte and follicular renewal at 38 +/-2 years of age due to the lack of formation of new granulosa cells. Oocytes in primordial follicles persisting after the end of the prime reproductive period accumulate genetic alterations resulting in an exponentially growing incidence of fetal trisomies and other genetic abnormalities with advanced maternal age. The secondary germ cells also develop in the OSC cultures derived from POF and aging ovaries. In vitro conditions are free of immune mechanisms, which prevent neo-oogenesis in vivo. Such germ cells are capable of differentiating in vitro into functional oocytes. This may provide fresh oocytes and genetically related children to women lacking the ability to produce their own follicular oocytes. Further study of "immune physiology" may help us to better understand ovarian physiology and pathology, including ovarian infertility caused by POF or by a lack of ovarian follicles with functional oocytes in aging ovaries. The observations indicating involvement of immunoregulation in physiological neo-oogenesis and follicular renewal from OSC during the fetal and prime reproductive periods are reviewed as well as immune system and age-independent neo-oogenesis and oocyte maturation in OSC cultures, perimenopausal alteration of homeostasis causing disorders of many tissues, and the first OSC culture clinical trial.

[Effect of NF-kappaB activation inhibitor curcumin on the oogenesis and follicular cell death in immune ovarian failure in mice].

In experiments on CBA mice, we studied the influence of an inhibitor of nuclear transcription factor kappaB activation curcumin, obtained from Curcuma longa, on the meiotic maturation of oocytes and apoptotic and necrotic death of follicular cells at immune ovary failure induced by immunization of animals with allogenic ovarian extracts. NF-kappaB plays a pivotal role in the induction of genes encoding pro-inflammatory factors (cytokines, adhesion molecules, inducible NO-synthase and cyclooxygenase) and in regulation of cell proliferation and death. It has been shown that immunization of mice increased the death of follicular cells through anapoptotic and necrotic pathways, which led to inflammatory response (according to blood leukogram and impairment the oocyte meiotic maturation at metaphase I and II). Intragastric administration of curcumin (Sigma, USA, 2 mg of the mouse weight, four times a week during the period of immunization) reduced the number of the follicular cells died through apoptotic and especially necrotic pathway. Curcumin attenuated an inflammatory response and improved the meiotic maturation of oocytes impaired under experimental immune ovarian failure in mice.

Immune physiology and oogenesis in fetal and adult humans, ovarian infertility, and totipotency of adult ovarian stem cells.

It is still widely believed that while oocytes in invertebrates and lower vertebrates are periodically renewed throughout life, oocytes in humans and higher vertebrates are formed only during the fetal/perinatal period. However, this dogma is questioned, and clashes with Darwinian evolutionary theory. Studies of oogenesis and follicular renewal from ovarian stem cells (OSCs) in adult human ovaries, and of the role of third-party bone marrow-derived cells (monocyte-derived tissue macrophages and T lymphocytes) could help provide a better understanding of the causes of ovarian infertility, its prevention, and potential treatment. We have reported differentiation of distinct cell types from OSC and the production of new eggs in cultures derived from premenopausal and postmenopausal human ovaries. OSCs are also capable of producing neural/neuronal cells in vitro after sequential stimulation with sex steroid combinations. Hence, OSC represent a unique type of totipotent adult stem cells, which could be utilized for autologous treatment of premature ovarian failure and also for autologous stem cell therapy of neurodegenerative diseases without use of allogeneic embryonic stem cells or somatic cell nuclear transfer. The in vivo application of sex steroid combinations may augment the proliferation of existing neural stem cells and their differentiation into mature neuronal cells (systemic regenerative therapy). Such treatment may also stimulate the transdifferentiation of autologous neural stem cell precursors into neural stem cells useful for topical or systemic regenerative treatment.

[The protective effect of molsidomin in immune ovarian pathology in mice].

Experimental immune ovarian failure in CBA mice was induced by either administration of xenogenic anti-ovarian antibodies (scheme 1) or immunization with allogenic ovarian extracts (scheme 2). It was shown that both types of treatment impaired the meiotic maturation of oocytes: the number of cells at the stages of metaphase I and metaphase II decreased compared to the cells of control mice. In both schemes of experiments, impaired oogenesis was accompanied by reduction of percentage of viable follicular cells and by increase in the part of cells possessing morphological features of apoptosis. In contrast, the number of necrotic follicular cells increased in scheme 2 only. The donor of nitric oxide molsidomin (10 mg/ kg), when injected an hour before administration of xenogenic anti-ovarian antibodies or allogenic ovary extracts, improved the meiotic maturation of oocytes and favored follicular, lymph nodes and thymus cells survival by decreasing the number of apoptotic and necrotic cells.

[Death of the ovarian follicular cells in mice with impaired oogenesis of the immune nature].

An impairment of the meiotic maturation of the oocytes has been shown in vitro for 2 types of immune damage of the ovaries in mice induced by xenogenic antiovarial antibodies and immunization with allogenic ovaria. Impairment of the oogenesis was followed by the follicular cell death, primarily by on the apoptic way, but under the immunization with allogenic ovary a necrotic way of their death was also activated.

Contraceptive vaccines.

The world's population is growing at a tremendous rate, affecting growth and development. Apart from this population growth, unintended pregnancies resulting in elective abortions continue to be a major public health issue. In over half of these unintended pregnancies, the women have used some type of contraception. Thus, there is an urgent need for a better method of contraception that is acceptable, effective and available. The contraceptive choices available to women at this time include steroid contraceptives, intrauterine devices, barrier methods, spermicides, natural family planning, male and female sterilisation, and recently available emergency contraceptives. Contraceptive vaccines (CVs) may provide viable and valuable alternatives that can fulfill most, if not all, properties of an ideal contraceptive. Since both the developed and most of the developing nations have an infrastructure for mass immunisation, the development of vaccines for contraception is an exciting proposition. The molecules that are being explored for CV development either target gamete production (gonadotropin releasing hormone, follicle-stimulating hormone and luteinising hormone), gamete function (zona pellucida [ZP] proteins and sperm antigens) or gamete outcome (human chorionic gonadotropin [hCG]). Disadvantages of CVs targeting gamete production are that they affect sex steroids and/or show only a partial effect in reducing fertility. CVs targeting gamete function are better choices. Vaccines based on ZP proteins are quite efficacious in producing contraceptive effects. However, they invariably induce oophoritis affecting sex steroids. Sperm antigens constitute the most promising and exciting targets for CVs. Several sperm-specific antigens have been delineated in several laboratories and are being actively explored for CV development. Antisperm antibody-mediated immunoinfertility provides a naturally occurring model to indicate how an antisperm vaccine will work in humans. Vaccines targeting gamete outcome primarily focus on the hCG molecule. The hCG vaccine is the first vaccine to undergo phase I and II clinical trials in humans. Both the efficacy and the lack of immunotoxicity have been reasonably well demonstrated for this vaccine. The present studies focus on increasing the immunogenicity and efficacy of this birth control vaccine.

Immunoglobulin protein and gene transcripts in ovarian follicles throughout oogenesis in the teleost Dicentrarchus labrax.

Transfer of immunoglobulins (IgM-like) from the female to the teleost embryo has been demonstrated but mechanisms of uptake into and storage within the eggs remain to be clarified. The monoclonal antibody DLIg3 against Dicentrarchus labrax Ig light chain revealed an active role of both follicle cells and oocytes in the Ig uptake. The primordial follicular cells showed DLIg3 immunoreactivity even at a pre-vitellogenetic stage. Early vitellogenetic oocytes (lipid vesicle stages) had DLIg3 staining of pore canals, plasmalemma and outer cortex and of their follicular cells. In protein yolk granule oocytes, DLIg3 staining was also detected within vesicles of the outer-mid cortex and juxtanuclear yolk granules; therefore, a centripetal transport of Ig throughout oocyte development is apparently carried out. Immunoelectron microscopy confirmed the presence of Ig within thecal and granulosa cells (and in the interposed basement membrane) of pre-vitellogenic and vitellogenic follicles. Thus, the transport of Ig to the egg apparently occurs also by transcytosis across the follicle cells. Igs were localised in the pore canals surrounding the microvilli and in vesicles of outer-mid cortex of vitellogenic oocytes. Reverse transcription/polymerase chain reaction with primers designed for the constant region of sea bass Ig light chain detected Ig mRNA in hydrated oocytes, a smaller content in released eggs and no signal in larvae at day two post-hatching. These findings show that a significant level of Ig gene transcription in the oocyte and/or a transfer of transcripts may also occur.

Immunohistochemical characterization of a stage-specific antigen during oogenesis and spermatogenesis recognized with monoclonal antibody.

In order to detect and characterize novel molecules which function in oogenesis, immunohistochemical study using a monoclonal antibody (MAb) raised against oocytes of Xenopus laevis was carried out. The distribution of the detectable molecule with MAb X-80, which specifically reacts with Xenopus previtellogenic oocytes; stages I and II (Dumont, 1972), in particular was analyzed. The hamster, mouse, chick, quail, Caenorhabditis elegans and Lilium longiflorum were also examined. Interestingly MAb X-80 bound not only in Xenopus oocytes but in its secondary spermatocytes and spermatids. Furthermore, MAb X-80 gave a similar staining pattern in the Lilium and other, although the stage when the positive reaction is detectable is different in the male and female germ cells.

Reversible inhibition of fertility in mice by passive immunization with anticumulus oophorus antibodies.

The mucified cumulus oophorus represents an outer enveloping layer around ovulated mammalian oocytes. This coat in its definitive expanded form appears late in the preovulatory development as a result of intensive secretion of intercellular matrix by cumulus cells. We have shown recently that antibodies to the cumulus matrix inhibit human fertilization in vitro. This study was undertaken to assess, in an animal model, the effects of anticumulus oophorus antibodies on fertility by use of different passive immunization protocols. A purified anticumulus immunoglobulin fraction was prepared from hyperimmune rabbit serum and administered at different times before and after mating to mice superovulated with equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG). A dose-dependent negative effect of this anticumulus antibody preparation on the number of fertilized eggs recovered from the oviducts of treated animals was observed when the antibodies were given before mating. High antibody doses also interfered with oocyte maturation and ovulation if applied on the day of eCG treatment, but no effects on these processes were found when the antibodies were given on the day of hCG treatment. The antifertility effect of anticumulus antibodies was reversible and the antibodies did not affect postfertilization development. These findings make cumulus oophorus antigens serious candidates for the development of a contraceptive vaccine.

sn-1,2-diacylglycerol levels increase in progesterone-stimulated Xenopus laevis oocytes.

Full-grown Xenopus laevis oocytes resume meiosis from prophase arrest in response to progesterone stimulation. Recent studies have shown that the tumor promoter, 12-O-tetradecanoylphorbol 13-acetate (TPA), a very potent activator of protein kinase C, can also induce the resumption of meiosis in amphibian oocytes. We have investigated the possibility that sn-1,2-diacylglycerol (DAG), the intracellular activator of protein kinase C, may be involved in the pathway normally used by progesterone. We have found that full-grown oocytes arrested in meiotic prophase contain 48 +/- 5 pmoles DAG/oocyte. This level increases within the first 5 minutes following the addition of progesterone and reaches a maximum of 75 +/- 10 pmoles following 60 minutes of steroid stimulation. Progesterone induces the up-regulation of a Na+/H+ antiport in the plasma membrane of the oocyte causing an increase in pHi following 60 minutes of steroid stimulation. We have found that the addition of 200 microM DAG (1,2-dioctanoylglycerol, diC8) to the culture medium can cause a partial up-regulation of this Na+/H+ pump in the absence of hormonal stimulation. These results suggest that DAG and protein kinase C may be involved in regulating certain aspects of meiotic maturation in progesterone-stimulated Xenopus oocytes.