Influences of FSH and EGF on primordial follicles during in vitro culture of caprine ovarian cortical tissue

Silva, José R.V.; Hurk, R. van den; Matos, Maria Helena Tavares de; Santos, Regiane R.; Pessoa, Cláudia; Moraes, Manoel O. de; Figueiredo, José Ricardo de

doi:10.1016/j.theriogenology.2003.09.014

Cited by 133 publications

(117 citation statements)

References 56 publications

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“…It is possible that under these conditions, factors other than EGF are probably involved in the initiation of primordial follicle growth in sheep, such as Kit ligand (Cavalcante et al, 2016). In this respect, other studies have demonstrated that EGF is not essential for the activation of bovine (at 10 ng/mL; Braw-Tal and Yossefi, 1997;Derrar et al, 2000), caprine (at 100 ng/mL; Silva et al, 2004) or feline (at 50, 100 or 200 ng/mL; Fujihara et al, 2014) primordial follicles. Moreover, in this study, it was noteworthy that the increase in EGF concentration (10, 50, 100, and specially the highest concentration of 200 ng/mL) inhibited spontaneous follicle activation compared to the control medium.…”

Section: Discussionmentioning

confidence: 92%

“…The developmental stages of preantral follicles have been defined previously (Silva et al, 2004): primordial (one layer of flattened granulosa cells around the oocyte) or growing follicles (intermediate: one layer of flattened to cuboidal granulosa cells; primary: one layer of cuboidal granulosa cells, and secondary: two or more layers of cuboidal granulosa cells around the oocyte and no sign of antrum formation). Additionally, these follicles were classified individually as histologically normal when an intact oocyte was present and surrounded by granulosa cells that were well organized in one or more layers and have no pyknotic nuclei.…”

Section: Morphological Analysis and Assessment Of In Vitro Follicularmentioning

confidence: 99%

“…For PCNA analysis, additional pairs of sheep ovaries (n = 6 ovaries) were collected, transported to the laboratory, fragmented and cultured (in α-MEM + or in α-MEM + containing 1 ng/mL EGF) as described above. Immunohistochemistry was performed as described in previous studies (Silva et al, 2004;Hoffman et al, 2008) with some modifications. Briefly, 5 µm sections were cut on a microtome (EasyPath, São Paulo, Brazil) and mounted in Starfrost glass slides (Knittel, Braunschweig, Germany).…”

Section: Proliferating Cell Nuclear Antigen (Pcna) Immunohistochemistrymentioning

confidence: 99%

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Blocking the PI3K pathway or the presence of high concentrations of EGF inhibits the spontaneous activation of ovine primordial follicles in vitro

Santos¹,

Santos²,

Menezes³

et al. 2017

Anim Reprod

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The aims of this study were to verify the effects of Epidermal Growth Factor (EGF) on the morphology, primordial follicle activation, growth and proliferation of granulosa cells of ovine follicles cultured in situ, as well as the effect of a PI3K inhibitor on the follicular activation. Ten ovine ovaries were divided into fragments, being one fixed for histological analysis (fresh control). The remaining fragments were cultured for 7 days in control medium (α-MEM + ) alone or supplemented with EGF (1, 10, 50, 100 or 200 ng/mL). Follicles were classified as normal or atretic, as primordial or growing, and the oocyte and follicle diameters were measured. PCNA immunohistochemistry was performed in the fresh control and in treatment that showed the best results for follicular activation. Pharmacologic inhibition of PI3K activity was performed through pretreatment in media added with 50 µM LY294002 for 1 h. The percentage of normal follicles decreased (P < 0.05) after 7 days of culture in all treatments compared to the fresh control. A significant reduction in the percentage of primordial follicles and an increase (P < 0.05) in the growing ones were observed in all treatments compared to fresh control. Furthermore, both the control medium and 1 ng/mL EGF promoted an increase (P < 0.05) in follicular activation compared to other EGF treatments. The PCNA-positive cells in the EGF treatment were higher (P < 0.05) than in fresh control and α-MEM + . Pretreatment of ovarian tissue with PI3K inhibitor significantly inhibited (P < 0.05) α-MEM + -stimulated primordial follicle activation, but had no effect on EGF-stimulated activation (P > 0.05). In conclusion, PI3K pathway mediates the in vitro spontaneous activation of sheep primordial follicles. Moreover, EGF may act indirectly on follicular activation by promoting granulosa cell proliferation at 1 ng/mL, and EGF inhibited follicle activation in concentrations similar or higher than 10 ng/mL.

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Section: Discussionmentioning

confidence: 92%

Section: Morphological Analysis and Assessment Of In Vitro Follicularmentioning

confidence: 99%

Section: Proliferating Cell Nuclear Antigen (Pcna) Immunohistochemistrymentioning

confidence: 99%

See 1 more Smart Citation

Blocking the PI3K pathway or the presence of high concentrations of EGF inhibits the spontaneous activation of ovine primordial follicles in vitro

Santos¹,

Santos²,

Menezes³

et al. 2017

Anim Reprod

View full text Add to dashboard Cite

show abstract

“…The developmental stages of follicles have been defined previously (Silva et al, 2004) as primordial (one layer of flattened granulosa cells around the oocyte) or growing follicles To evaluate follicular activation, the percentages of histologically normal primordial and growing follicles were calculated before (fresh control) and after culture in each medium.…”

Section: Assessment Of Follicular Development and Survivalmentioning

confidence: 99%

“…Interestingly, in most of the in vitro culture systems, independent of the culture period, the medium has been totally or partially replaced by fresh medium every other day (Silva et al, 2004 andMuruvi et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

In vitro development of primordial follicles after long-term culture of goat ovarian tissue

Matos

Bruno

Rocha

et al. 2011

Research in Veterinary Science

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This study aims to investigate the effects of follicle stimulating hormone (FSH) and fibroblast growth factor-2 (FGF-2) on the survival and growth of caprine preantral follicles. Ovarian tissues were cultured for 1, 7, 14, 21 or 28 days in medium supplemented with FSH (FSH-2d or FSH-7d, i.e., with replacement of the culture medium every 2 or 7 days, respectively) or FSH + FGF-2 (replacement of the medium every 2 days). Non-cultured (control) and cultured ovarian fragments were processed for histological and ultrastructural analysis. After 28 days of culture, the media supplemented with FSH-2d was the most effective in maintaining the percentage of normal follicles and in promoting follicular growth. Furthermore, both treatments with FSH increased the percentage of the primary follicles. However, ultrastructural studies did not confirm follicular integrity from 14 days of culture onward. In conclusion, culturing tissue for up to 7 days in medium containing FSH alone or combined with FGF-2 maintains caprine preantral follicle integrity and promotes their growth in vitro.

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Glucose activates the primordial follicle through the AMPK/mTOR signaling pathway

Dong

et al. 2020

Clinical & Translational Med

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Background We have previously found that the energy level in sows affects the activation of primordial follicles. Glucose is the primary metabolic substrate of dietary energy and its effect and mechanism of action with regards to the activation and development of primordial follicle remain unclear. Studies utilizing several different animal cells have shown that energy stress, induced by glucose starvation, activates AMPK and participates in a variety of cellular processes by regulating the Hippo and mTOR signaling pathways. However, whether glucose can affect primordial follicle activation through the above pathways has not been reported. Methods We developed an in vitro culture system for mouse ovaries to investigate the effects of glucose on the primordial follicle activation. Protein expression of AMPK‐Hippo‐YAP and AMPK‐mTOR pathway was investigated under glucose starvation and optimal glucose level treatment. Then, ovaries were treated with AICAR or Compound C in vitro to explore the effect of AMPK activation or inhibition on primordial follicle activation, and the changes of AMPK‐Hippo‐YAP and AMPK‐mTOR signaling pathways. Finally, investigated the signaling pathways affected by glucose potentially affecting the primordial follicle activation in vivo. Results The glucose was an essential nutrient for primordial follicle activation and we identified 25 mM glucose as the optimal level ( P < .05) for the primordial follicle activation in vitro. The glycolysis pathway was involved in primordial follicle activation ( P < .05) of ovaries cultured in vitro. The glucose affected the activation of primordial follicles in vitro through AMPK/mTOR signaling pathway by AMPK activation or inhibition treatment and follicle ratio count ( P < .05). Moreover, glucose affected the primordial follicle activation of ovary in vivo via mTOR signaling pathway. Conclusions This study demonstrates that glucose affects the primordial follicle activation through the AMPK/mTOR rather than the AMPK/Hippo signaling pathway.

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Influences of FSH and EGF on primordial follicles during in vitro culture of caprine ovarian cortical tissue

Cited by 133 publications

References 56 publications

Blocking the PI3K pathway or the presence of high concentrations of EGF inhibits the spontaneous activation of ovine primordial follicles in vitro

Blocking the PI3K pathway or the presence of high concentrations of EGF inhibits the spontaneous activation of ovine primordial follicles in vitro

In vitro development of primordial follicles after long-term culture of goat ovarian tissue

Glucose activates the primordial follicle through the AMPK/mTOR signaling pathway

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