References of "Fransolet, Maïté"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailInfluence of mouse strain on ovarian tissue recovery after engraftment with angiogenic factor.
Fransolet, Maïté ULg; Henry, Laurie ULg; Labied, Soraya et al

in Journal of Ovarian Research (2015), 8(1), 14

BACKGROUND: For women facing gonadotoxic treatment, cryopreservation of ovarian tissue with subsequent retransplantation during remission is a promising technique for fertility preservation. However ... [more ▼]

BACKGROUND: For women facing gonadotoxic treatment, cryopreservation of ovarian tissue with subsequent retransplantation during remission is a promising technique for fertility preservation. However, follicle loss within grafted ovarian tissue can be caused by ischemia and progressive revascularization. Several xenograft models using different immunodeficient rodent lines are suitable for studying ovarian tissue survival and follicular viability after frozen-thawed ovarian cortex transplantation. SCID mice, which are deficient for functional B and T cells, are the most commonly used mice for ovarian xenograft studies. However, due to incomplete immunosuppression, NOD-SCID mice displaying low NK cell function and an absence of circulating complement might be more appropriate. The present study aims to define the most appropriate immunodeficient mouse strain for ovarian tissue xenotransplantation by comparing ovarian graft recovery in SCID and NOD-SCID mice following engraftment in the presence of isoform 111 of vascular endothelial growth factor. METHODS: Sheep ovarian cortex fragments were embedded in a collagen matrix, with or without VEGF111, before being stitched onto the ovaries of SCID and NOD-SCID mice. Transplants were recovered after 3 days to study early revascularization or after 3 weeks to evaluate follicle preservation and tissue fibrosis through histological analyses. RESULTS: At day 3, vessels were largely reorganized in the ovarian grafts of both mouse strains. After 3 weeks, the cortical tissue was clearly identifiable in SCID mice but not in NOD-SCID mice. Upon VEGF111 treatment, vascularization was significantly improved 3 days after transplantation in SCID mice. This increase in vessel density was correlated with better follicular preservation in SCID mice 3 weeks after transplantation. Fibrosis was not decreased by VEGF treatment in either mouse strain. CONCLUSIONS: Tissue architecture and follicular morphology were better preserved in ovarian tissues grafted in SCID mice in comparison with NOD-SCID mice. Moreover, tissue revascularization was improved in SCID mice by VEGF111 graft treatment. Thus, we consider SCID mice to be the best murine model for studying ovarian tissue xenografts. [less ▲]

Detailed reference viewed: 18 (1 ULg)
Full Text
Peer Reviewed
See detailIsoform 165 of vascular endothelial growth factor in collagen matrix improves ovine cryopreserved ovarian tissue revascularisation after xenotransplantation in mice.
Henry, Laurie ULg; LABIED, Soraya ULg; Fransolet, Maïté ULg et al

in Reproductive biology and endocrinology (2015), 13(1), 15

BACKGROUND: Aggressive anti-cancer treatments can result in ovarian failure. Ovarian cryopreservation has been developed to preserve the fertility of young women, but early graft revascularisation still ... [more ▼]

BACKGROUND: Aggressive anti-cancer treatments can result in ovarian failure. Ovarian cryopreservation has been developed to preserve the fertility of young women, but early graft revascularisation still requires improvement. METHODS: Frozen/thawed sheep ovarian cortical biopsies were embedded in collagen matrix with or without isoform 165 of vascular endothelial growth factor (VEGF165) and transplanted into ovaries of immunodeficient mice. Ovaries were chosen as transplantation sites to more closely resemble clinical conditions in which orthotopic transplantation has previously allowed several spontaneous pregnancies. RESULTS: We found that VEGF165 significantly increased the number of Dextran-FITC positive functional vessels 3 days after grafting. Dextran- fluorescein isothiocyanate (FITC) positive vessels were detectable in 53% and 29% of the mice in the VEGF-treated and control groups, respectively. Among these positive fragments, 50% in the treated group displayed mature smooth-muscle-actin-alpha (alpha-SMA) positive functional vessels compared with 0% in the control group. CD31 positive murine blood vessels were observed in 40% of the VEGF165 transplants compared with 21% of the controls. After 3 weeks, the density of murine vessels was significantly higher in the VEGF165 group. CONCLUSION: The encapsulation of ovarian tissue in collagen matrix in the presence of VEGF165 before grafting has a positive effect on functional blood vessel recruitment. It can be considered as a useful technique to be improved and further developed before human clinical applications in female cancer patients in the context of fertility preservation. [less ▲]

Detailed reference viewed: 18 (0 ULg)
Full Text
Peer Reviewed
See detailStrategies for Using the Sheep Ovarian Cortex as a Model in Reproductive Medicine
Fransolet, Maïté ULg; Labied, Soraya ULg; Henry, Laurie ULg et al

in PLoS ONE (2014), 9(3), 91073

Objective: To evaluate and compare the distribution and density of primordial follicles within a whole sheep ovary and to gain insight into how to overcome the impact of natural follicular heterogeneity ... [more ▼]

Objective: To evaluate and compare the distribution and density of primordial follicles within a whole sheep ovary and to gain insight into how to overcome the impact of natural follicular heterogeneity on the experimental results. Design: Histological study. Setting: Academic research center. Animals: Five- to nine-month-old ewes. Interventions: Freshly sampled whole sheep ovaries were collected and prepared for histological analysis. Main Outcome Measure(s): The follicular densities and distributions were determined for hematoxylin and eosin sections. A mathematical model was derived based on the follicle counts and Monte-Carlo simulations. Results: Heterogeneous distributions and densities of primordial follicles were identified 1) for distinct areas of the same ovarian cortex, 2) between the ovaries of the same animal and 3) across different ewes. A mathematical model based on the analysis of 37,153 primordial follicles from 8 different ovaries facilitated the estimation of the number of cortical biopsies and sections that had to be analyzed to overcome such heterogeneity. Conclusion: The influence of physiological follicular heterogeneity on experimental and clinical results can be overcome when a definite number of cortical pieces and sections are taken into consideration. [less ▲]

Detailed reference viewed: 18 (7 ULg)
Full Text
Peer Reviewed
See detailIsoform 111 of vascular endothelial growth factor (VEGF111) improves angiogenesis of ovarian tissue xenotransplantation
Labied, Soraya ULg; Delforge, Yves ULg; Munaut, Carine ULg et al

in Transplantation (2013), 95(3), 426-433

Background: Cryopreservation of cortex ovarian tissue before anti-cancer therapy is a promising technique for fertility preservation mainly in children and young women. Ischemia in the early stage after ... [more ▼]

Background: Cryopreservation of cortex ovarian tissue before anti-cancer therapy is a promising technique for fertility preservation mainly in children and young women. Ischemia in the early stage after ovarian graft causes massive follicle loss by apoptosis. VEGF111 is a recently described VEGF isoform that does not bind to the extracellular matrix, diffuse extensively and is resistant to proteolysis. These properties confer a significantly higher angiogenic potential to VEGF111 in comparison to the other VEGF isoforms. Methods: We evaluated the morphology of cryopreserved sheep ovarian cortex, grafted in the presence or absence of VEGF111. Ovarian cortex biopsies were embedded in type I collagen with or without VEGF111 addition before transplantation to SCID mice ovaries. Transplants were retrieved 3 days or 3 weeks later. Follicular density, vasculature network, haemoglobin content and cell proliferation were analysed. Results: Addition of VEGF111 increased density of functional capillaries (p=0.01) 3 days after grafting. By double immunostaining of Ki-67 and von Willebrand Factor (vWF) we demonstrated that proliferating endothelial cells were found in 83% of the VEGF111 group when compared to 33% in the control group (p=0.001). This angio-stimulation was associated with a significant enhancement of haemoglobin content (p=0.03). Three weeks after transplantation, the number of primary follicles was significantly higher in VEGF111 grafts (p=0.02). Conclusion: VEGF111 accelerates blood vessels recruitment, functional angiogenesis and improves the viability of ovarian cortex by limiting ischemia and ovarian cortex damage. [less ▲]

Detailed reference viewed: 51 (19 ULg)
Peer Reviewed
See detailDoes vascular endothelial growth factor improve ovarian tissue recovery after cryopreservation?
Henry, Laurie ULg; Fransolet, Maïté ULg; Labied, Soraya ULg et al

in Giornale italiano di obstetricia e gynecologia (2012)

Detailed reference viewed: 35 (7 ULg)