Impact of various endocrine and paracrine factors on in vitro culture of preantral follicles in rodents

Abstract

Folliculogenesis is a complex process regulated by various paracrine and autocrine factors. In vitro growth systems of primordial and preantral follicles have been developed for future use of immature oocytes, as sources of fertilizable oocytes and for studying follicular growth and oocyte maturation mechanisms. Rodents were often chosen for in vitro follicular culture research and a lot of factors implicated in folliculogenesis have been identified using this model. To date, the mouse is the only species in which the whole process of follicular growth, oocyte maturation, fertilization and embryo transfer into recipient females was successfully performed. However, the efficiency of in vitro culture systems must still be considerably improved. Within the follicle, numerous events affect cell proliferation and the acquisition of oocyte developmental competency in vitro, including interactions between the follicular cells and the oocyte, and the composition of the culture medium. Effects of the acting factors depend on the stage of follicle development, the culture system used and the species. This paper reviews the action of endocrine, paracrine factors and other components of culture medium on in vitro growth of preantral follicles in rodents.

Association between insulin-like growth factor-I, thyroxine and follicle stimulating hormone on the survival and in vitro development of caprine preantral follicles

“…However, the medium containing T 4 (10)/IGF-I showed an increase in oocyte diameter. It can be suggested that IGF-I has a relevant participation in the increase of follicular diameter, corroborating the results found earlier by Demeestere et al (2005) and Martins et al (2010). This effect seems to be linked to an increase of the mitotic rate of granulosa cells and an increase in oocyte size.…”

“…This effect seems to be linked to an increase of the mitotic rate of granulosa cells and an increase in oocyte size. Furthermore, it was demonstrated that IGF-I has a participation in the increase of DNA content, promoting functional integrity and stimulating steroidogenesis during the culture of preantral follicles of mice (Demeestere et al, 2005).…”

Isolation, characterization, andin vitroandin vivodifferentiation of putative thecal stem cells

“…The ovaries of 2-day-old mice are devoid of distinct follicular structures, and when the follicles grow to enclose two to three layers of granulosa cells, theca cells start to surround the follicles and acquire the steroidogenic ability regulated primarily by LH. Androstenedione, a steroid hormone produced by theca cells, is converted into estradiol by granulosa cells (1,2). Thus, folliculogenesis is a complex process in which germ cells (oocytes) and two types of somatic cells (theca cells and granulosa cells) interact through paracrine or direct mechanisms.…”

“…Mature theca cells can be distinguished by their morphology and location in situ and can be isolated easily in a crude suspension for in vitro analysis. Much information has been reported about the factors and mechanisms regulating theca cell steroidogenesis in several mammalian species (2). However, our knowledge about theca cell recruitment and growth is limited because of the lack of in vitro experimental systems to isolate, culture, and differentiate immature theca cells.…”

Effects of dibutyryl cyclic adenosine monophosphate and human chorionic gonadotropin on the formation of antral follicle-like structures by bovine cumulus—oocyte complexes

“…These results may support the work of Hartshorne et al (1994), who reported that dbcAMP stimulated antrum formation, whereas hypoxanthine also stimulated antrum formation but did not affect follicle growth. Folliculogenesis is a complex developmental process that is regulated by various endocrine, paracrine and autocrine factors, as well as intraovarian cellcell and cell-matrix interactions (Rodgers et al, 2003;Demeestere et al, 2005). Therefore, it is difficult to define the precise and individual roles that FSH and LH play in follicular growth and development.…”