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Terren C, Bindels J, Nisolle M, Noël A, Munaut C. Evaluation of an alternative heterotopic transplantation model for ovarian tissue to test pharmaceuticals improvements for fertility restoration. Reprod Biol Endocrinol 2022; 20:35. [PMID: 35183206 PMCID: PMC8857804 DOI: 10.1186/s12958-022-00910-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 02/13/2022] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Ovarian tissue cryopreservation and transplantation (OTCTP) is currently the main option available to preserve fertility in prepubertal patients undergoing aggressive cancer therapy treatments. However, a major limitation of OTCTP is follicle loss after transplantation. The mouse is a model of choice for studying ovarian function and follicle development after ovarian tissue grafting in vivo. In these mouse models, ovarian tissue or ovaries can be transplanted to different sites. Our aim was to evaluate a new alternative to heterotopic transplantation models that could be useful to test pharmaceutical improvement for ovarian grafts after OTCTP. METHODS Slow frozen murine whole ovaries were transplanted into the mouse ears (between the external ear skin layer and the cartilage). Ovarian transplants were recovered after 3, 14 or 21 days. Grafts were analyzed by immunohistochemistry and follicle density analyses were performed. RESULTS An increase of ovarian vascularization (CD31 and Dextran-FITC positive staining), as well as cellular proliferation (Ki67 staining) were observed 3 weeks after transplantation in comparison to 3 days. Fibrosis density, evaluated after Van Gieson staining, decreased 3 weeks after transplantation. Furthermore, transplantation of cryopreserved ovaries into ovariectomized mice favored follicle activation compared to transplantation into non-ovariectomized mice. CONCLUSION The present study indicates that surgical tissue insertion in the highly vascularized murine ear is an effective model for ovarian grafting. This model could be helpful in research to test pharmaceutical strategies to improve the function and survival of cryopreserved and transplanted ovarian tissue.
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Affiliation(s)
- Carmen Terren
- Laboratory of Tumor and Development Biology, GIGA-Cancer, University of Liège, Tour de Pathologie , Site Sart-Tilman, Building 23/4, Avenue Hippocrate, 13, 4000, Liege, Belgium
| | - Jules Bindels
- Laboratory of Tumor and Development Biology, GIGA-Cancer, University of Liège, Tour de Pathologie , Site Sart-Tilman, Building 23/4, Avenue Hippocrate, 13, 4000, Liege, Belgium
| | - Michelle Nisolle
- Laboratory of Tumor and Development Biology, GIGA-Cancer, University of Liège, Tour de Pathologie , Site Sart-Tilman, Building 23/4, Avenue Hippocrate, 13, 4000, Liege, Belgium
- Department of Obstetrics and Gynecology, Hôpital de La Citadelle, University of Liège, B-4000, Liège, Belgium
| | - Agnès Noël
- Laboratory of Tumor and Development Biology, GIGA-Cancer, University of Liège, Tour de Pathologie , Site Sart-Tilman, Building 23/4, Avenue Hippocrate, 13, 4000, Liege, Belgium
| | - Carine Munaut
- Laboratory of Tumor and Development Biology, GIGA-Cancer, University of Liège, Tour de Pathologie , Site Sart-Tilman, Building 23/4, Avenue Hippocrate, 13, 4000, Liege, Belgium.
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Terren C, Nisolle M, Munaut C. P-444 Presence of pharmacological inhibitors of the PI3K/PTEN/Akt and mTOR signalling pathways during cryopreservation and organotypic cultures of murine ovaries limits early primordial follicle depletion. Hum Reprod 2021. [DOI: 10.1093/humrep/deab127.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Study question
Which signalling pathways are implicated in primordial follicle activation induced by cryopreservation and/or organotypic culture? Is it possible to limit this activation through pharmacological inhibitors?
Summary answer
Our findings provide support for the hypothesis that mTOR and PI3K inhibitors might represent an attractive tool to delay cryopreservation- and culture-induced primordial follicle activation.
What is known already
Cryopreservation of ovarian tissue containing immature primordial follicles followed by auto-transplantation (OTCTP) is the only option available to preserve the fertility of prepubertal patients or patients requiring urgent therapy for aggressive malignancies. However, a major obstacle in this process is follicular loss immediately after grafting, possibly due to slow neovascularization, apoptosis and/or massive follicular recruitment. In vitro and in vivo studies indicate that the PI3K/PTEN/Akt and mTOR signalling pathways are involved in follicle activation. The transplantation process seems to be the major cause of primordial follicle activation after OTCTP but information about how cryopreservation itself impacts follicle activation is sparse.
Study design, size, duration
Whole murine ovaries (4-8-weeks old) were cryopreserved by slow freezing and exposed to LY294002 (a powerful PI3K inhibitor) or rapamycin (a specific mTOR inhibitor) during cryopreservation and/or organotypic in vitro culture for a 24 h or 2 days.
Participants/materials, setting, methods
Western Blot and immunofluorescence analyses were used to determine the activation of PI3K/PTEN/Akt and mTOR signalling pathways in murine ovaries cryopreserved and/or organotypically cultured with/without inhibitors.Follicles were quantified according to their maturation degree on H&E stained histological sections.
Main results and the role of chance
Ratio of phosphorylated Akt or rps6 to total proteins (p-Akt/Akt and p-rps6/rps6) was increased in slow-frozen murine ovaries compared to control fresh ovaries, indicating an activation of the PI3K/PTEN/Akt and mTOR signalling pathways. The use of pharmacological inhibitors of follicle signalling pathways (LY294002 (25µM) and rapamycin (1µM)) during the cryopreservation process decreased p-Akt/Akt and p-rps6/rps6 ratios. In vitro organotypic culture for 24 h increased only the activation of the PI3K/PTEN/Akt pathway, as shown by increased p-Akt/Akt ratio in fresh ovaries cultured for 24 h compared to fresh non-cultured ovaries. This activation can be counteracted by cryopreservation of murine ovaries with rapamycin followed by in vitro culture for 24 h in the presence of LY294002. Follicle density quantifications indicated that when cryopreserved ovaries were maintained in culture for 2 days, a decrease of primordial follicle density concomitant with an increase of secondary and more mature follicles were found in comparison to slow-frozen/thawed ovaries without culture. Supplementation of the culture medium with LY294002 and rapamycin for 24 h or 2 days preserved primordial follicle densities compared to ovaries cultured without inhibitors.
Limitations, reasons for caution
This study is an in vitro study using murine ovaries. To analyze the efficiency of LY294002 and rapamycin to limit cryopreservation and transplantation induced follicle recruitment, these inhibitors should be tested in an in vivo model. Furthermore, these findings will need to be confirmed with human samples.
Wider implications of the findings
We showed for the first-time that the sequential use of pharmacological inhibitors, rapamycin during the slow freezing process followed by organotypic culture supplemented with LY294002, is effective to limit early primordial follicle depletion.
Trial registration number
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Affiliation(s)
- C Terren
- University of Liège, Laboratory of Tumor and Development Biology GIGA-Cancer, Liège, Belgium
| | - M Nisolle
- University of Liège, Department of Obstetrics and Gynecology Hôpital de la Citadelle, Liège, Belgium
| | - C Munaut
- University of Liège, Laboratory of Tumor and Development Biology GIGA-Cancer, Liège, Belgium
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Terren C, Nisolle M, Munaut C. P–444 Presence of pharmacological inhibitors of the PI3K/PTEN/Akt and mTOR signalling pathways during cryopreservation and organotypic cultures of murine ovaries limits early primordial follicle depletion. Hum Reprod 2021. [DOI: 10.1093/humrep/deab130.443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Study question
Which signalling pathways are implicated in primordial follicle activation induced by cryopreservation and/or organotypic culture? Is it possible to limit this activation through pharmacological inhibitors?
Summary answer
Our findings provide support for the hypothesis that mTOR and PI3K inhibitors might represent an attractive tool to delay cryopreservation- and culture-induced primordial follicle activation.
What is known already
Cryopreservation of ovarian tissue containing immature primordial follicles followed by auto-transplantation (OTCTP) is the only option available to preserve the fertility of prepubertal patients or patients requiring urgent therapy for aggressive malignancies. However, a major obstacle in this process is follicular loss immediately after grafting, possibly due to slow neovascularization, apoptosis and/or massive follicular recruitment. In vitro and in vivo studies indicate that the PI3K/PTEN/Akt and mTOR signalling pathways are involved in follicle activation. The transplantation process seems to be the major cause of primordial follicle activation after OTCTP but information about how cryopreservation itself impacts follicle activation is sparse.
Study design, size, duration
Whole murine ovaries (4–8-weeks old) were cryopreserved by slow freezing and exposed to LY294002 (a powerful PI3K inhibitor) or rapamycin (a specific mTOR inhibitor) during cryopreservation and/or organotypic in vitro culture for a 24 h or 2 days.
Participants/materials, setting, methods
Western Blot and immunofluorescence analyses were used to determine the activation of PI3K/PTEN/Akt and mTOR signalling pathways in murine ovaries cryopreserved and/or organotypically cultured with/without inhibitors.Follicles were quantified according to their maturation degree on H&E stained histological sections.
Main results and the role of chance
Ratio of phosphorylated Akt or rps6 to total proteins (p-Akt/Akt and p-rps6/rps6) was increased in slow-frozen murine ovaries compared to control fresh ovaries, indicating an activation of the PI3K/PTEN/Akt and mTOR signalling pathways. The use of pharmacological inhibitors of follicle signalling pathways (LY294002 (25µM) and rapamycin (1µM)) during the cryopreservation process decreased p-Akt/Akt and p-rps6/rps6 ratios. In vitro organotypic culture for 24 h increased only the activation of the PI3K/PTEN/Akt pathway, as shown by increased p-Akt/Akt ratio in fresh ovaries cultured for 24 h compared to fresh non-cultured ovaries. This activation can be counteracted by cryopreservation of murine ovaries with rapamycin followed by in vitro culture for 24 h in the presence of LY294002. Follicle density quantifications indicated that when cryopreserved ovaries were maintained in culture for 2 days, a decrease of primordial follicle density concomitant with an increase of secondary and more mature follicles were found in comparison to slow-frozen/thawed ovaries without culture. Supplementation of the culture medium with LY294002 and rapamycin for 24 h or 2 days preserved primordial follicle densities compared to ovaries cultured without inhibitors.
Limitations, reasons for caution
This study is an in vitro study using murine ovaries. To analyze the efficiency of LY294002 and rapamycin to limit cryopreservation and transplantation induced follicle recruitment, these inhibitors should be tested in an in vivo model. Furthermore, these findings will need to be confirmed with human samples.
Wider implications of the findings: We showed for the first-time that the sequential use of pharmacological inhibitors, rapamycin during the slow freezing process followed by organotypic culture supplemented with LY294002, is effective to limit early primordial follicle depletion.
Trial registration number
/
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Affiliation(s)
- C Terren
- University of Liège, Laboratory of Tumor and Development Biology GIGA-Cancer, Liège, Belgium
| | - M Nisolle
- University of Liège, Department of Obstetrics and Gynecology Hôpital de la Citadelle, Liège, Belgium
| | - C Munaut
- University of Liège, Laboratory of Tumor and Development Biology GIGA-Cancer, Liège, Belgium
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Terren C, Nisolle M, Munaut C. Pharmacological inhibition of the PI3K/PTEN/Akt and mTOR signalling pathways limits follicle activation induced by ovarian cryopreservation and in vitro culture. J Ovarian Res 2021; 14:95. [PMID: 34275490 PMCID: PMC8287691 DOI: 10.1186/s13048-021-00846-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 07/06/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Cryopreservation and transplantation of ovarian tissue (OTCTP) represent a promising fertility preservation technique for prepubertal patients or for patients requiring urgent oncological management. However, a major obstacle of this technique is follicle loss due to, among others, accelerated recruitment of primordial follicles during the transplantation process, leading to follicular reserve loss in the graft and thereby potentially reducing its lifespan. This study aimed to assess how cryopreservation itself impacts follicle activation. RESULTS Western blot analysis of the PI3K/PTEN/Akt and mTOR signalling pathways showed that they were activated in mature or juvenile slow-frozen murine ovaries compared to control fresh ovaries. The use of pharmacological inhibitors of follicle signalling pathways during the cryopreservation process decreased cryopreservation-induced follicle recruitment. The second aim of this study was to use in vitro organotypic culture of cryopreserved ovaries and to test pharmacological inhibitors of the PI3K/PTEN/Akt and mTOR pathways. In vitro organotypic culture-induced activation of the PI3K/PTEN/Akt pathway is counteracted by cryopreservation with rapamycin and in vitro culture in the presence of LY294002. These results were confirmed by follicle density quantifications. Indeed, follicle development is affected by in vitro organotypic culture, and PI3K/PTEN/Akt and mTOR pharmacological inhibitors preserve primordial follicle reserve. CONCLUSIONS Our findings support the hypothesis that inhibitors of mTOR and PI3K might be an attractive tool to delay primordial follicle activation induced by cryopreservation and culture, thus preserving the ovarian reserve while retaining follicles in a functionally integrated state.
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Affiliation(s)
- Carmen Terren
- Laboratory of Tumor and Development Biology, GIGA-Cancer, University of Liège, Tour de Pathologie (B23), Site Sart-Tilman, Building 23/4, Avenue Hippocrate, 13, 4000, Liege, Belgium
| | - Michelle Nisolle
- Laboratory of Tumor and Development Biology, GIGA-Cancer, University of Liège, Tour de Pathologie (B23), Site Sart-Tilman, Building 23/4, Avenue Hippocrate, 13, 4000, Liege, Belgium.,Department of Obstetrics and Gynecology, Hôpital de La Citadelle, University of Liège, B-4000, Liège, Belgium
| | - Carine Munaut
- Laboratory of Tumor and Development Biology, GIGA-Cancer, University of Liège, Tour de Pathologie (B23), Site Sart-Tilman, Building 23/4, Avenue Hippocrate, 13, 4000, Liege, Belgium.
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