Project description:Vitrification is a method for long-term biological sample cryopreservation without causing intra- and extra-cellular ice formation. We recently established a novel closed vitrification system to cryopreserve mouse ovarian follicles. Using the 3D alginate hydrogel encapsulated in vitro follicle growth (eIVFG) method, we have demonstrated that compared to freshly-harvested follicles, vitrified follicles have normal follicle and oocyte reproductive outcomes. Our recent study further demonstrated the faithful preservation of molecular signatures of follicle-stimulating hormone (FSH)-stimulated follicle maturation in vitrified follicles. However, it is unknown whether ovulation, another crucial gonadotropin-dependent follicular event, and involved ovulatory gene regulatory pathways are well conserved in vitrified follicles. Fresh and vitrified follicles grown for 8 days by eIVFG were collected at 0, 1, 4 and 8-hour post human chorionic gonadotropin (hCG) treatment for the single-follicle RNA sequencing. Principal component analysis (PCA) and Pearson’s correlation analysis revealed that vitrified follicles have similar transcriptomic profiles to fresh follicles. Furthermore, the expression of several genes essential for ovulation were comparable between vitrified and fresh follicles. In summary, these results demonstrate that our closed vitrification system preserves follicular transcriptomic dynamics during ex vivo ovulation. Together with our previous findings that vitrification preserves FSH-stimulated follicle maturation, the integration of vitrification of immature follicles and eIVFG has a great potential to serve as an additional fertilization preservation approach for young cancer patients and endangerers species. Moreover, follicle vitrification enables a high-content ovarian follicle biobank, which can greatly improve the throughput of eIVFG for studying ovulation biology, anovulatory disease, toxicology, and novel contraceptive drug development targeting ovulation.

Project description:Ovulation refers to the process when the ovarian surface-facing wall of a preovulatory follicle ruptures and releases the cumulus oocyte complex (COC) into the oviduct or fallopian tube in response to hormonal cues. In parallel, the unruptured wall of the follicle within the ovary transitions to becoming a progesterone-producing corpus luteum. Ovulation is essential for fertilization and eventual pregnancy. Disruption of ovulation, whether purposefully through contraceptive intervention or idiopathically in cases of anovulatory infertility, has translational implications for human health. Importantly, key processes of ovulation, including follicle rupture and luteinization, are recapitulated in models of ex vivo ovulation despite the absence of an intact hypothalamic-pituitary-gonadal axis and intra-ovarian cues. In our study, we used an ex vivo ovulation model to identify functional and molecular differences between distinct regions of the follicle wall, which we refer to as the ruptured and unruptured sides. We observed that the unruptured side of the follicle wall exhibits hallmarks of luteinization after ovulation while the ruptured side exhibits signs of cell death. RNA-sequencing of these specific follicle regions revealed 2,099 differentially expressed genes between follicle sides without hCG exposure and 1,673 between follicle sides 12 hours post-hCG, which were further validated in vivo. We found enriched pathways that recapitulate known ovulation biology, including oxidative stress on the ruptured side and angiogenesis on the unruptured side. We also identified previously unappreciated pathways that may play an important role in ovulation, such as amino acid transport and Jag-Notch signaling on the ruptured side, as well as metal ion processing and IL-11 signaling on the unruptured side. Ultimately our studies demonstrate that our ex vivo model recapitulates known in vivo ovarian biology, identifies pathways that may be novel regulators of ovulation and luteinization, and may have future translational applications for the study of ovulatory disorders and the development of novel non-hormonal contraceptives.

Project description:Dibutyl phthalate (DBP), di-2-ethylhexyl phthalate (DEHP), and benzyl butyl phthalate (BBP) are three phthalates commonly found in consumer products, including the plastic coating of pharmaceuticals and personal care products. Folliculogenesis, a tightly regulated process occurring in the ovary, is the maturation of an immature primordial follicle to a mature antral follicle. Follicles house the oocyte and antral follicles specifically play a crucial role in ovarian steroidogenesis and ovulation. DBP, BBP, and DEHP have been associated with inhibited antral follicle growth in vitro, decreased ovulation rates in vitro, and decreased antral follicle counts in women. However, little is known about the effects of a three-phthalate mixture on antral follicles in vivo. The objective of this study was to evaluate the effects of a human relevant mixture of DBP, BBP, and DEHP on ovarian follicles through proteome profiling analysis. CD-1 female mice (60 days old) were pipet fed tocopherol stripped corn oil (vehicle control) only or a phthalate mixture (52% DBP, 36% DEHP, and 12% BBP dissolved in vehicle) which modeled human follicular fluid concentrations. The mice were treated with 32µg/kg/day (PHT Mix 32; cumulative estimate in general population) and 500µg/kg/day (PHT Mix 500; cumulative estimate in occupationally exposed individuals) for 10 consecutive days. Proteome profiling of antral follicles (>250µm) was performed via label-free tandem mass spectrometry. A total of 5,417 antral follicle proteins were identified in the three groups, of which 194 were differentially abundant between the vehicle and PHT Mix 32 group, and 136 between the vehicle and PHT Mix 500 group. Gene ontology analysis revealed that the two treatments of the phthalate mixture upregulate and downregulate distinctive processes, supporting non-monotonic effects of phthalates on the antral follicle proteome. Taken together, these results reveal that a human relevant mixture of DBP, BBP, and DEHP alters the antral follicle proteome and merits further evaluation to elucidate the molecular mechanisms by which phthalates cause negative reproductive outcomes.

Project description:Experiments were designed to evaluate changes in the transcriptome (mRNA levels) in the ovulatory, luteinizing follicle of rhesus monkeys, using a controlled ovulation (COv) model that permits analysis of the naturally selected, dominant follicle at specific intervals (0, 12, 24, 36 hours) after exposure to an ovulatory (exogenous hCG) stimulus during the menstrual cycle. Total RNA was prepared from individual follicles (n=4-8/timepoint), with an aliquot used for microarray analysis (AffymetrixTM Rhesus Macaque Genome Array) and the remainder applied to quantitative real-time PCR (q-PCR) assays. The microarray data from individual samples distinctly clustered according to timepoints, and ovulated follicles displayed markedly different expression patterns from unruptured follicles at 36 h. Between timepoint comparisons revealed profound changes in mRNA expression profiles. The dynamic pattern of mRNA expression for steroidogenic enzymes (CYP17A, CYP19A, HSD3B2, HSD11B1, HSD11B2), StAR, and gonadotropin receptors (LHCGR, FSHR) as determined by microarray analysis correlated precisely with those from blinded q-PCR assays. Patterns of mRNA expression for EGF-like factors (AREG, EREG) and processes (HAS2, TNFAIP6) implicated in cumulus-oocyte maturation/expansion were also comparable between assays. Thus, several mRNAs displayed the expected expression pattern for purported theca (e.g., CYP17A, AREG), granulosa (CYP19A, FSHR), cumulus (HAS2, TNFAIP6) cell, and surface epithelium (HSD11B) related genes in the rodent/primate preovulatory follicle. This database will be of great value in analyzing molecular and cellular pathways associated with periovulatory events in the primate follicle (e.g. follicle rupture, luteinization, inflammatory response, and angiogenesis), and for identifying novel gene products controlling mammalian fertility. Keywords: time course Total RNA was prepared from individual follicles (n=4-8/timepoint). Dominant follicles were selected specific intervals (0, 12, 24, 36 hours) after exposure to an ovulatory (exogenous hCG) stimulus during the menstrual cycle.

Project description:Running title: More insights into ovulation Purpose:Ovulation is the process by which mature follicles release fertilized oocytes under the stimulation of gonadotropin. This involves the precise interaction and destiny of various cells in the follicle. Granulosa cells (GCs) are the only cells that recognize and respond to ovulation LH (or HCG) signals. Therefore, the classification and deep interpretation of genes in GCs under LH surge stimulation is the key to understand ovulation. Methods: In this study, RNA-seq, Q-PCR, Western blot, gene knockout, gene knockout and other experimental techniques were used to conduct trend and classification analysis of the genes regulated by ovulation signal of LH at the cellular and individual levels. Genes that may be involved in ovulation were screened, identified and were selected for functional verification. Results:(1) Firstly, 7104 and 347 mRNA and Long noncoding RNA (LncRNA) that may be involved in ovulation activity were screened at the gene level by transcriptome sequencing technology, respectively. According to gene expression, they were divided into activated, inhibited and transient activated gene expression patterns. 44 secreted proteins, 62 transcription factors, 22 periodic expression characteristic genes, 10 ovulation process unknown genes, 16 LncRNA-target gene cis pair combinations and 41 highly expressed LncRNA were identified and listed in the three models;(2) The functions of LncRNA Gm12840 and Gm20186 were studied at the cellular level. The results showed that knockdown Gm12840/20186 not only inhibited the proliferation and hormone synthesis of GCs, but also induced cell apoptosis;(3) The function of LncRNA Gm12840 was further studied in mice, and Gm12840 knockout mice were constructed by CRISPR/CAS9 technology: Results It was found that Gm12840 knockout significantly increased the number of antral follicles and ovulation, and significantly inhibited the number of atretic follicles and antral follicles not discharged after ovulation. Gm12840 knockout significantly increased litter size at 2-3 months of age, but also significantly inhibited litter size at 7-9 months of age. Meanwhile, Gm12840 knockout also significantly inhibited the number of follicles growing in the ovary of 11-month-old mice;(4) Finally, transcriptomic sequencing analysis of wilt-type and Gm12840-/- mouse GCs showed 349 genes were differentially expressed. KEGG enrichment analysis and WB results showed that Gm12840 knockout enhanced mTOR and MAPK signals. Conclusions:The above results screened and identified genes with potential research value during ovulation process, and took LncRNA Gm12840 as an example to verify their functions at the cell and individual levels, providing reference for further revealing the ovulation process.

Project description:Luteinizing hormone (LH) activation of the EGF receptor/RAS/ERK1/2 pathway is essential for ovulation and luteinization because granulosa cell depletion of Erk1/2 (Erk1/2gc-/- mice) renders mice completely infertile. Because of their potential as mediators of ERK1/2-dependent granulosa cell differentiation, we disrupted genes encoding the CCAAT/enhancer-binding proteins, (C/EBP) a and C/EBPb. Female Cebpbgc-/- mutant mice but not Cebpagc-/- mice were subfertile whereas Cebpa/bgc-/- double mutant females were sterile. Follicles failed to ovulate, ovaries were devoid of corpora lutea, luteal cell marker genes (Lhcgr, Prlr, Ptgfr, Cyp11a1 and Star) were absent and serum progesterone levels were low. Microarray analyses identified numerous C/EBPa/b target genes in eCG-hCG treated mice. At 4h post-hCG, a subset (19%) of genes altered in the Cebpa/b depleted cells was also altered in Erk1/2 depleted cells; hence they are common effectors of ERK1/2. Additional genes down-regulated in the Cebpa/b depleted cells at 8 and 24h post-hCG include known (Akr1b7, Runx2, Star, Saa3) and novel (Abcb1b, Apln, Igfbp4, Prlr, Ptgfr Timp4) C/EBP target genes including effectors of vascular cell development. Bhmt, a gene controlling methionine metabolism and expressed exclusively in liver and kidney, was high in WT luteal cells but totally absent in Cebpa/b mutant cells. Because numerous genes potentially associated with vascular development were suppressed in the mutant cells, C/EBPa/b appear to dictate the luteinization process by also controlling genes that regulate the formation of the extensive vascular network required to sustain luteal cells. Thus, C/EBPa/b mediate several aspects of granulosa cell differentiation as well as the complex process of luteinization. Five granulosa cell treatments were included: CEBPM-NM-1/M-NM-2 conditional KO ovary, eCG-treated 48h, hCG 4h wild type ovary, eCG-treated 48h, hCG 8h CEBPM-NM-1/M-NM-2 conditional KO ovary, eCG-treated 48h, hCG 8h wild type ovary, eCG-treated 48h, hCG 24h CEBPM-NM-1/M-NM-2 conditional KO ovary, eCG-treated 48h, hCG 24h

Project description:Vitrification is a method for long-term biological sample cryopreservation that transforms cells into a glass-like state by cooling without causing intra- and extra-cellular ice formation, which is a major driver of cell cryoinjury. Using an alginate hydrogel encapsulated in vitro follicle growth (eIVFG) system, we have recently demonstrated that compared to freshly-harvested follicles, vitrified follicles have normal follicle and oocyte reproductive outcomes as well as comparable expression levels of several genes that are essential for gonadotropin-dependent folliculogenesis and oogenesis. However, it is unknown whether vitrification preserves the molecular signatures of folliculogenesis at the whole transcriptomic level, which is the primary research focus in this study. Multilayered secondary follicles with a diameter of 130 -160 µm were mechanically isolated from 16-day-old CD-1 female mice and vitrified using the closed vitrification method. After a 2-week storage in liquid nitrogen, vitrified follicles were warmed, and together with freshly-harvested follicles, cultured for 8 days using the eIVFG method. Next, mature antral follicles from day 8 were collected for single-follicle RNA sequencing using the SMART-seq RNA-seq method. Principal component analysis (PCA) and Pearson’s correlation analysis revealed that vitrified follicles have similar transcriptomic profiles to fresh follicles. Using the criterion of fold change >2 or <0.5 and a false discovery rate (FDR) adjusted p-value < 0.05, there were 35 differentially expressed genes out of a total of 11,806 detected genes between vitrified and fresh follicles, among which 17 were up-regulated and 18 were down-regulated in vitrified follicles. To the best of our knowledge, none of those differentially expressed genes identified between vitrified and fresh follicles have been shown to be critical to folliculogenesis and oogenesis. Meanwhile, gene ontology (GO) and KEGG pathway analysis over these 35 genes using the functional annotation tool DAVID revealed that no GO terms or signaling pathways were significantly enriched. Furthermore, the expression of several genes essential for the gonadotropin-dependent folliculogenesis and oogenesis were comparable between vitrified and fresh follicles, including granulosa cell-specific genes (Cyp19a1, Amh, Inha, Inhba, Inhbb, and Fshr), theca cell-specific genes (Cyp17a1, Col1a2, and Col3a1), and oocyte-specific genes (Gdf9, Bmp15, Zp1, Zp2, and Zp3). Equally important, Lhcgr, the gene that is primarily expressed in theca cells of preantral follicles and then greatly induced in mural granulosa cells in antral follicles to prepare for the luteinizing hormone (LH) surge and ovulation, also had comparable mRNA expression levels between vitrified and fresh follicles. Taken together, these results demonstrate that vitrification preserves the follicular cell transcriptome and molecular signatures of gonadotropin-dependent folliculogenesis in the eIVFG system. In conclusion, our study re-evaluates individual follicle cryopreservation by using the closed vitrification method in a more in-depth perspective and proves that vitrification preserves the follicular cell transcriptome in the eIVFG system, thus providing a robust model for fertility preservation, conservation of endangered species, and also establishing a high-content ovarian follicle biobank for studying ovarian biology and female reproductive toxicology.

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Effect of Tyrphostin-AG4178 on ex-vivo mouse ovarian follicles in eIVFG ovulation system

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