The production of eggs – oogenesis, is dependent on proper genetic control. Hippo signalling pathway is essential for maintaining optimum organ size. It contains several negative growth regulators. The AKT signalling pathway has a key role in the initiation of follicle growth. The ovarian in vitro activation represents the autologous genetic treatment of the gonadal tissue in order to restore both reproductive and endocrine functions of the ovary.
Ovarian function is realized by creating the egg, which is connected with the determinate hormonal activity. Primordial follicles enter the further development by process of follicular activation and then undergo a series of developmental changes, until reaching maturity. During this process, a large number of follicles enter atresia, programmed apoptosis. Part of the follicles survives by making the cell cycle slower. Their dormant status is characterized by communication with surrounding granulosa cells and numerous mechanical and chemical factors controlling progression of their cell cycle. These factors control signalling activation of the pathways included in the primordial follicle dormant status regulation, like Hippo and Akt signalling.
Reduction of the number of primordial follicles leads to failure of ovarian function and, ultimately, to menopause. Reduction of the number of primordial follicles is associated with cellular and molecular damage of the gonadal tissue, which gradually reduces the possibility of tissue to perform its functions. Removal or correction of these negative effects by biotechnological regenerative processes leads to recovery of ovarian function.
On the other hand, cryopreservation of gonadal tissue, with re-transplantation has long been used for the purpose of preservation of fertility in patients who must undergo gonadotoxic therapy. On that occasion, the ovarian cortex is routinely fragmented for more efficient vitrification and grafting. Wedged resection has been used for a century as a treatment of PCOS in order to induce follicle growth. A newer version of this therapy is ovarian drilling, by diathermy or laser. Other authors suggest transvaginal ovarian trauma puncture in order to restitute the ovary function. These papers indicate a potential change of conditions of folliculogenesis by using physical methods.
Japanese group showed that the fragmentation of mouse ovaries leads to actin polymerization and interruption of Hippo signal. Disruption of this signalling pathway leads to the increased expression of downstream growth factors, promotion of follicle growth and maturation of oocytes. After laparoscopic ovariectomy, parts of the ovarian cortex was vitrified. After thawing, in the framework of preparation for autografting into mesosalpinx, the fragmentation and exposure of AKT by simulating substances (Stanford based) was done during two days. Laparoscopic auto-transplantation of activated tissue in mesosalpinx was done in this study. After the transfer three pregnancies occurred, one of which ended in miscarriage, while the two children born with normal outcome, until the year 2015.
The SEGOVA approach has several essential advantages over Kawamura’s approach. First, conservative surgery with partial decortication instead of ovariectomy is performed, allowing orthotopic instead of heterotopic approach during re-transplantation. Besides that, instead of chemical stimulation of Akt pathway, autologous PLRP growth factors are used. The second laparoscopic operation is avoided, using needle injection under colour Doppler ultrasonic guidance.