Feasibility of Secondary Follicle Isolation, Culture and Achievement of In-Vitro Oocyte Maturation from Superovulated Ovaries: An Experimental Proof-of-Concept Study Using Mice

Fertility preservation through ovarian stimulation, aiming at cryopreserving mature oocytes or embryos, is sometimes unsuccessful. This clinical situation deserves novel approaches to overcome infertility following cancer treatment in patients facing highly gonadotoxic treatment. In this controlled experimental study, we investigated the feasibility of in-vitro culturing secondary follicles isolated from superovulated ovaries of mice recently treated with gonadotropins. The follicle yields of superovulated ovaries were 45.9% less than in unstimulated controls. Follicles from superovulated ovaries showed faster growth pace during the initial 7 days of culture and secreted more 17β-estradiol by the end of culture vs controls. Parameters reflecting the outcome of follicular development and oocyte maturation competence in vitro were similar between superovulated and control groups, with a similar follicle size at the end of culture and around 70% survival. Nearly half of cultured follicles met the criteria for in-vitro maturation in both groups and approximately 60% of those achieved a mature MII oocyte, similarly in both groups. Over 60% of obtained MII oocytes displayed normal-looking spindle and chromosome configurations, without significant differences between the groups. Using a validated follicle culture system, we demonstrated the feasibility of secondary follicle isolation, in-vitro culture and oocyte maturation with normal spindle and chromosome configurations obtained from superovulated mice ovaries.

Figla promotes secondary follicle growth in mature mice

The in vitro growth (IVG) of human follicles is a potential fertility option for women for whom cryopreserved ovarian tissues cannot be transplanted due to the risk of cancer cell reintroduction; however, there is currently no established method. Furthermore, optimal IVG conditions may differ between the follicles of adult and pre-pubertal females due to molecular differences suggested by basic research. To systematically identify differences between the secondary follicles of adult and pre-pubertal females, a comparative transcriptomic study using mice was conducted herein. Among differentially expressed genes (DEGs), Figla was up-regulated in mature mice. We successfully down-regulated Figla expression in secondary follicle oocytes by a Figla siRNA microinjection, and the subsequent IVG of follicles showed that the diameter of these follicles was smaller than those of controls in mature mice, whereas no significant difference was observed in premature mice. The canonical pathways of DEGs between control and Figla-reduced secondary follicles suggest that Figla up-regulates VDR/RXR activation and down-regulates stem cell pluripotency as well as estrogen signaling. We demonstrated for the first time that folliculogenesis of the secondary follicles of premature and mature mice may be regulated by different factors, such as Figla with its possible target genes, providing insights into optimal IVG conditions for adult and pre-pubertal females, respectively.

Red LED light promotes hair follicle development to improve fibre quality in Su line Angora rabbit

Background: Light has crucial roles in animal physiological activities. This study aimed to investigate the effects of different colours of light-emitting diodes (LEDs) on rabbit fibre quality and hair follicle development. 50 three-month-old Su line Angora rabbits were randomly assigned to five groups. Treatment groups were exposed to same intensities of red, green and blue LED light under 16 h light:8 h dark photoperiod regimes. Control groups were exposed to white light and black. The trial spanned 73 days. Results: Results showed that LED colours exerted different effects on wool yield, fibre quality, hormones and hair follicle development. The wool yield of red group was higher than that of white, green and black groups (P<0.05). The shoulder fibre length of red group was higher than that of white and green groups (P<0.05). The coarse fibre diameter of white group was lower than that of green and black groups (P<0.05). The fibre diameter of red group was the lowest and was lower by 13.9% than that of control group (P>0.05). The coarse fibre ratio of green group was higher (13.31%) than that of red group (3.81%, P<0.05). The follicle groups of white, green and black groups consisted of 1 primary follicle associated with 3 or 4 secondary follicle groups and those of blue group consisted of 1 primary follicle associated with 5–10 secondary follicle groups. The follicle of red group consisted of numerous secondary follicles and a few primary follicles. In same magnification, the numbers of follicle groups of white, red, green, blue and black groups were 14.0, 16.5, 10.0, 11.67 and 11.0, respectively. The numbers of follicle groups of red and green groups significantly differed (P<0.05). Serum melatonin (MT) of red group was highest than that of white and green groups (P<0.01), higher than that of black group (P<0.05), serumTriiodothyronine (T 3 ) of red group was higher than that of white and black groups (P<0.05). Conclusions: Thus, the data reveal that red LED light can improve fibre quality, this may be due to red LED light which can enhance the secretion of melatonin to promote hair follicle development .

Evaluation of amniotic hydrogel’s impact on the development of murine pre-antral follicles in mouse model

Global average infertility rate is about 6– 12%, and in Vietnam at around 7.7%. As a result, there is a high demand for treatment, especially for female infertility. In vitro maturation (IVM) was evaluated and proven to be the most popular and promising at the moment. In long-term cultivation, the follicle was observed to extend, therefore, the usage of a supporting frame is quite necessary to maintain follicle’s natural sphere structure as well as completing the mature process. Amniotic membrane is an avascular membrane, composed of collagen, fibronectin, nidogen, proteoglycan, containing a big number of growth – factors with antimicrobial, anti-inflammatory, low immunogenicity and viscoelasticity properties. Amniotic hydrogel owns structure formed with thin fibers to help preserve the main component as collagen, which can turn to gel form at 37 degree Celsius. With those properties, amniotic hydrogel showed high potential as a scaffold for the follicle. When amniotic hydrogel is used as a scaffold for cultivating of secondary follicle (100 – 130 µm), the size of oocyte and follicle increased after 12 days of culturing, along with the formation of antrum. The results demonstrated the possibility to use amniotic hydrogel as a scaffold for the development of the secondary follicle.