RESUMEN
The aim of the present study was to test whether inhibition of ovarian primordial follicles and subsequent activation can be achieved by transient mTOR inhibition. In this preclinical investigation, forty-five female immature Wistar rats were randomized in 5 groups. The control group received subcutaneous saline injections. The other groups received Everolimus, Everolimus plus Verapamil, Everolimus plus Fisetin, and Fisetin alone. Primary and secondary outcomes were measured in the left ovary after a treatment period of 8 weeks. Ten days later, animals received 35 IU FSH for 4 days and 35 IU of hCG on the 5th day. The same parameters were examined in the right ovary. AMH, estradiol, and progesterone levels were assessed at the end of both interventions. Significantly, more primordial and less atretic follicles were observed in the Everolimus plus Verapamil group. AMH and progesterone levels were substantially lower in the Everolimus group. Interestingly, after ovarian stimulation higher levels of AMH and progesterone were observed in the Everolimus plus Verapamil group. Immunoblot analysis of ovarian extracts revealed that the administration of Everolimus led to a significant reduction in the mTORC1-mediated phosphorylation of the 70-kDa ribosomal protein S6 kinase 1. This decrease was reversed in the presence of FSH after stopping drug administration. The expression of the anti-apoptotic molecule Bcl2 as well as of LC3-II and ATG12 was increased after removal of the Everolimus plus Verapamil combination, indicating reduced apoptosis and increased autophagy, whereas the levels of the proliferation marker PCNA in the granulosa cells were elevated, consistent with initiation of follicular growth.Thus, the combination of Everolimus plus Verapamil is capable of increasing the number of competent primordial follicles while reducing atresia.
Asunto(s)
Diferenciación Celular/efectos de los fármacos , Everolimus/farmacología , Preservación de la Fertilidad/métodos , Folículo Ovárico/efectos de los fármacos , Verapamilo/farmacología , Animales , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Evaluación Preclínica de Medicamentos , Femenino , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Folículo Ovárico/citología , Ratas , Ratas WistarRESUMEN
OBJECTIVE: The efficacy of vascular endothelial growth factor (VEGF), COX-2, calcium and aromatase inhibitors in an ovarian hyperstimulation syndrome (OHSS) rat model was tested. METHODS: One hundred and eight female Wistar rats were randomly divided in nine groups. The control group received saline, while the OHSS group received rec-FSH for 4 consecutive days. The other seven groups received rec-FSH (4d) and Bevacizumab twice, Parecoxib daily, Verapamil daily, Parecoxib daily and Bevacizumab twice, Verapamil daily and Bevacizumab twice, Parecoxib and Verapamil daily, Letrozole and Meloxicam daily, respectively. All groups received also hCG at the 5th day. RESULTS: All intervention groups were characterized by reduced vascular permeability compared to the OHSS group, which in the groups of Verapamil (Calcium inhibition) and Parecoxib + Verapamil (COX-2 + Calcium inhibition) presented significant statistical difference. The Verapamil group showed the lowest corpus luteum formation, while the Parecoxib (COX-2 inhibition), the Parecoxib + Verapamil (COX-2 + Calcium inhibition), the Bevacizumab + Parecoxib (VEGF + COX-2 inhibition) and the Bevacizumab + Verapamil (VEGF + Calcium inhibition) groups were also characterized by lower corpus luteum numbers compared to the OHSS group. Furthermore, lower graafian follicle formation was observed in the above groups, while the ovarian weight and the hormonal profile were not significantly affected. CONCLUSIONS: Studying the different check points of the VEGF pathway, we conclude that targeting calcium pathways could be beneficial for the vascular permeability control in an OHSS animal model.