FSH Promotes Rat Follicle Development Through Inhibition of the Hippo Signalling Pathway

Purpose: Whether FSH promotes follicle growth by inhibiting the Hippo signalling pathway.METHODS: Ovaries were cultured in vitro into a control group (no intervention), an FSH group (0.3 IU/mL FSH), and a VP group (10 µg/mL vetiporfin). HE staining and follicle counts were performed at each stage after 3 hours of in vitro culture. Immunohistochemistry was performed to study the expression levels of LATS2, YAP, PLATS2, and PYAP, and their expression levels in each group were also analysed by Western blot.The number of secondary follicles was significantly increased in the FSH group, the arrangement of granulosa cells was neater, the nuclear fixation was reduced, and the number of atretic follicles was decreased in the VP group. The number of secondary follicles was significantly increased, the number of atretic follicles was reduced, and granulosa cell nuclear consolidation was reduced in the VP+FSH group. Immunohistochemistry showed that LATS2 and YAP expression levels were significantly increased and PLATS2 and PYAP expression levels were relatively decreased in the FSH group, PYAP and PLATS2 expression levels were significantly increased and YAP expression was significantly decreased in the VP group, and YAP and LATS2 expression levels were significantly increased and PYAP and PLATS2 expression levels were significantly decreased in the VP+FSH group. By Western blot, LATS2 and YAP were elevated and PYAP and PLAT2 were decreased in the FSH group, LATS2 and YAP were decreased and PYAP and PLATS were significantly elevated in the VP group, and LATS2 and YAP were elevated and PYAP and PLATS2 were decreased in the VP+FSH group.CONCLUSION: FSH promotes follicle development by inhibiting the Hippo signalling pathway.

In Vitro Follicle Growth, Maturation, and Gene Expression: Three-Dimensional (3D) Matrigel Culture versus Two-Dimensional Culture (2D)

This research aimed to compare the In Vitro growth, maturation, and gene expression in ovarian follicles collected from adult mice (6–8-week-old) between two-dimensional and three-dimensional cultures. First, we confirmed In Vitro follicle growth and maturation using adult mice with outbred characteristics and analyzed the expression of genes related to follicular development. We found that the three-dimensional culture system utilizing a Matrigel drop to create an in vivo-like ovarian microenvironment was more efficient in terms of In Vitro follicle growth, maturation, and gene expression than the two-dimensional system (non-physical environment). The in vivo-like three-dimensional culture of ovarian follicles provides new insights into the physiology and development of ovarian follicle in vivo, thereby contributing to new strategies to improve female fertility.

Effect of oestrogen on mouse follicle growth and meiotic resumption

Summary Many studies have shown that oestrogen affects late follicular development, but whether oestrogen is involved in other aspects of folliculogenesis remains unclear. In this study, two antagonists of oestrogen, tamoxifen and G15, were used to determine the effects of oestrogen on folliculogenesis. Mouse preantral follicles and cumulus–oocyte complexes (COCs) were cultured in vitro. The results showed that follicle growth stimulated using pregnant mare serum gonadotrophin (PMSG) was inhibited using tamoxifen, whether in vivo or in vitro. The average diameters, the maximum diameters of follicles and the numbers of follicles with a diameter of more than 300 μm decreased significantly following a 4-day culture with tamoxifen. G15, the antagonist of oestrogen via the membrane receptor, did not change follicular growth stimulated by PMSG in vitro. Results of in vitro maturation of COCs showed that germinal vesicle breakdown (GVBD) occurred spontaneously (95.1%) after 2 h in culture, and the GVBD ratio changed little with the addition of either oestrogen or 10 μM G15. However, first polar body (PBI) extrusion was driven by oestrogen markedly and supplementation with 10 μM G15 inhibited PBI extrusion (82.4% vs 55.0%) significantly. These results demonstrated that oestrogen promotes follicle growth through the nuclear receptor during follicle growth and then triggers the transition of metaphase to anaphase through the membrane receptor during meiotic resumption. So oestrogen plays a progressive role in the two phases of follicle growth and oocyte meiotic resumption.

Vitrification preserves murine ovarian follicular cell transcriptome in a 3D encapsulated in vitro follicle growth system

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 demonstrated that compared to freshly-harvested follicles, vitrified follicles had normal follicle and oocyte reproductive outcomes. However, it is unknown whether vitrification preserves molecular signatures of folliculogenesis, which is the primary research focus in this study. Six fresh and six vitrified antral follicles grown from eIVFG were collected on day 8 for the whole single-follicle RNA sequencing. Principal component analysis (PCA) and Pearson’s correlation analysis revealed that vitrified follicles had similar transcriptomic profiles to fresh follicles. There were 35 differentially expressed genes between vitrified and fresh follicles, however, none of those genes have been shown to be critical to folliculogenesis and oogenesis. Meanwhile, gene ontology (GO) and KEGG pathway analysis revealed that no GO terms or signaling pathways were significantly enriched. Furthermore, the expression of genes essential for the gonadotropin-dependent folliculogenesis and oogenesis were comparable between vitrified and fresh follicles. Taken together, these results demonstrate that vitrification preserves follicular cell transcriptome and molecular signatures of gonadotropin-dependent folliculogenesis in the eIVFG system, 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.

Successful pregnancy after ovulation induction with human chorionic gonadotropin in a woman with selective luteinising hormone deficiency

Selective LH deficiency has been described in several men, but only in two women who presented normal pubertal development but secondary amenorrhoea due to anovulation. Despite its rarity, this condition represents a valuable model for studying the processes regulated by FSH or LH during late folliculogenesis and ovulation in humans. A woman previously diagnosed with selective LH deficiency due to a homozygous germline splice site mutation in LHB (IVS2 + 1G→C mutation) was submitted to an individualised ovarian induction protocol, first with recombinant LH and then with highly purified urinary hCG. Ovarian follicle growth and ovulation were achieved, and a healthy baby was born after an uneventful term pregnancy. The treatment described herein demonstrates that the clinical actions of exogenous LH or hCG in inducing late-stage follicular development in women with deficient LH production or performance might be interchangeable or inevitable, once FSH-dependent early follicular growth is assured.

Transcriptome Analysis Reveals an Inhibitory Effect of Dihydrotestosterone-Treated 2D- and 3D-Cultured Dermal Papilla Cells on Hair Follicle Growth

Dermal papillae are a target of androgen action in patients with androgenic alopecia, where androgen acts on the epidermis of hair follicles in a paracrine manner. To mimic the complexity of the dermal papilla microenvironment, a better culture model of human dermal papilla cells (DPCs) is needed. Therefore, we evaluated the inhibitory effect of dihydrotestosterone (DHT)-treated two-dimensional (2D)- and 3D-cultured DPCs on hair follicle growth. 2D- and 3D-cultured DPC proliferation was inhibited after co-culturing with outer root sheath (ORS) cells under DHT treatment. Moreover, gene expression levels of β-catenin and neural cell adhesion molecules were significantly decreased and those of cleaved caspase-3 significantly increased in 2D- and 3D-cultured DPCs with increasing DHT concentrations. ORS cell proliferation also significantly increased after co-culturing in the control-3D model compared with the control-2D model. Ki67 downregulation and cleaved caspase-3 upregulation in DHT-treated 2D and 3D groups significantly inhibited ORS cell proliferation. Sequencing showed an increase in the expression of genes related to extracellular matrix synthesis in the 3D model group. Additionally, the top 10 hub genes were identified, and the expression of nine chemokine-related genes in DHT-treated DPCs was found to be significantly increased. We also identified the interactions between transcription factor (TF) genes and microRNAs (miRNAs) with hub genes and the TF–miRNA coregulatory network. Overall, the findings indicate that 3D-cultured DPCs are more representative of in vivo conditions than 2D-cultured DPCs and contribute to our understanding of the molecular mechanisms underlying androgen-induced alopecia.