Viability and growth of feline preantral follicles in vitro cultured with insulin growth factor and epidermal growth factor supplemented medium

Abstract

ContentsIn vitro culture of ovarian preantral follicles has emerged as a reproductive technology aimed at obtaining large amount of oocytes for in vitro embryo production. The addition of growth factors (GF) in the in vitro culture of preantral follicles of different species has provided superior results of follicular development, antrum formation and proliferation of granulosa cells. However, there are only few reports regarding the use of these factors on feline preantral follicle in vitro culture. Thus, the aim of this study was to investigate the effect of a combination of IGF-1 and EGF on in vitro viability and growth of preantral follicles and enclosed oocytes collected from domestic cats. A total of 64 follicles characterized by multilayer granulosa cells were isolated and individually cultured for 6 days (T6) in minimum essential medium supplemented with IGF-1+ EGF (100 ng/ml each) or without (control). A higher percentage of follicles were viable after culture with GF than without, and an increase in size when IGF-1+ EGF were added to the medium (170 ± 32.4 μm (T0) vs. 201 ± 22.3 μm (T6); p < .05) was observed. An increase in the diameter was also observed in follicles cultured without GF, but this increase was only 8.3% compared to 15.4% of those cultured with GF (p < .05). No differences were found in the diameter of oocytes contained in follicles cultured in the non-supplemented or supplemented media (107.9 ± 11.8 μm (T0) vs. 113.2 ± 15.6 μm (T6); p > .05). These data suggest that the addition of IGF-1 and EGF to the culture medium promotes the in vitro development of preantral follicles of cats.

Epidermal growth factor regulates autophagy activity and endocytosis of yak cumulus cells in a concentration-dependent manner

“…These results indicated that these key regulatory molecules could help yak cumulus cells maintain autophagy and endocytic activity during development. Recently, some studies have pointed out that the addition of melatonin, trehalose and other substances in vitro contributes to oocyte development (33,34), while EGF, as an important paracrine factor in follicles and a commonly used nutritional supplement in vitro culture, plays a crucial role in regulating cumulus cell growth, oocyte maturation and early embryonic development (19,21,23). To further investigate the function of EGF in the regulation of autophagy and endocytosis of cumulus cells, we detected the expression of related genes and proteins in cumulus cells treated with different concentrations of EGF and gefitinib.…”

“…Related studies have shown that EGF promotes not only the maturation of oocytes but also their fertilization ability and embryo development and inhibits the apoptosis of oocytes during maturation and promotes the expansion of cumulus cells ( 19 , 20 ). Notably, the stimulative effect is related to the dose of EGF ( 21 ). Because the EGF signaling system of cumulus-oocyte complexes (COCs) matured in vitro is not perfect, it is difficult to simulate the physiological environment of follicles, resulting in poor development ability of oocytes in vitro and limiting the utilization efficiency of oocytes ( 22 , 23 ).…”

The never‐ending search of an ideal culture system for domestic cat oocytes and embryos

“…The major roles of growth factors include the regulation of apoptosis, cell differentiation and proliferation (Chang, Qiao, & Leung, 2016;Knight & Glister, 2006). Epidermal growth factor (EGF) contributes to maintain the viability of isolated follicles at different stage of development (primordial and preantral) after 6 or 14 days of culture (Alves et al, 2017;Fujihara, Comizzoli, Keefer, Wildt, & Songsasen, 2014). Cat oocytes exposed to EGF during IVM developed until late embryo stages at higher rates, further confirming the positive effect of this growth factor (Gómez, Pope, Davis, Harris, & Dresser, 2001;Merlo, Iacono, Zambelli, Prati, & Belluzzi, 2005).…”

“…Cat oocytes exposed to EGF during IVM developed until late embryo stages at higher rates, further confirming the positive effect of this growth factor (Gómez, Pope, Davis, Harris, & Dresser, ; Merlo, Iacono, Zambelli, Prati, & Belluzzi, ). Insulin‐like growth factor‐I (IGF‐I), alone or combined with EGF, is useful to promote both preantral follicle growth and oocyte nuclear maturation, as documented by several studies (Alves et al., ; Kitiyanant, Saikhun, & Pavasuthipaisit, ; Yıldırım, Vural, Küplülü, Özcan, & Polat, ).…”

Activation of Steroidogenesis, Anti-Apoptotic Activity, and Proliferation in Porcine Granulosa Cells by RUNX1 Is Negatively Regulated by H3K27me3 Transcriptional Repression

“…Granulosa cells (GCs), as a component in follicular units, are critical for supporting ovarian function and determining follicular fate through the function of estrogens, growth factors, and cytokines [1]. These factors have been categorized as follicular survival factors, including estradiol estrogen receptor α/β [2], insulin-like growth factor 1 (IGF-1) [3], epidermal growth factor [4], and follicular atresia factors, such as FOXO3/ FOXO1 [5,6], inhibin [7], and TNF-associated receptors [8]. GCs are autocrine, paracrine, and endocrine units.…”