Histological and immunohistochemical evaluation of granulosa cells during different stages of folliculogenesis in bovine ovaries

Abstract

Bovine granulosa cells (GC) vary in their morphological aspect during different stages of folliculogenesis. In this study, 10 morphologically normal bovine ovaries were collected to study the structural aspects of different stages of GC using intermediate filament protein antibodies including cytokeratin AE1/AE3 (AE1/AE3), vimentin, nectin-4 and desmin. Hormonal immunolocalization was assessed using the immunomarkers anti-Müllerian hormone (AMH) and inhibin alpha. In addition, tumour markers and proliferation markers using c-erbB-2 oncoprotein and proliferating cell nuclear antigen, respectively, were investigated. The immunolabelling of AE1/AE3 in GC was strongest in the early follicle stage and gradually decreased when reaching the Graafian follicle stage. Its immunolabelling increased again as the stage progressed from stage I to stage III. The immunolabelling of inhibin alpha was inversely proportional to that of AE1/AE3 in the developing ovarian follicles as their immunolabelling is opposite to each other during folliculogenesis. AMH was immunopositive in almost all GC stages in different intensities and percentages, except for some negative staining in the atretic IV follicles. The atretic IV follicle is a unique type of atretic follicle that shows Call-Exner body formation, which was mainly found in older cows in this study. The distinct patterns of immunoreactivity for various types of immunomarkers in the different GC stages will play an important role in diagnostic assistance of various follicle conditions, including cystic ovaries and GC tumours.

The Stemness of Human Ovarian Granulosa Cells and the Role of Resveratrol in the Differentiation of MSCs—A Review Based on Cellular and Molecular Knowledge

“…At this point, they differentiate into GCs, become cuboidal in shape and are separated from the oocyte by the zona pellucida (ZP) [ 15 ]. A change in GC cell shape from flattened to cuboidal marks the transition from primordial to primary follicle [ 16 ]. Cell shape regulates proliferation and steroidogenesis in GCs, with their proliferation and differentiation both occurring during folliculogenesis [ 17 ].…”

“…A subset of antral follicles, known as the dominant follicles, will progress to the pre-ovulatory stage in each menstrual cycle. In response to luteinizing hormone (LH), ovulation occurs and the oocyte is released, in tandem with the rupture of basal lamina, luteinization of theca and GCs, and formation of the corpus luteum (CL) [ 16 , 22 ]. CL expresses higher concentrations of steroidogenic enzymes (predominantly P450scc ), leading to significant increase in pregnenolone and progesterone production.…”

“…FSH and LH concentrations peak at ovulation, then remain lower throughout the luteal phase, to prevent new follicles from developing and becoming dominant [ 27 ]. Hormone levels flux throughout the menstrual cycle to control the development of the bidirectionally communicating oocyte and follicle [ 16 ].…”

Expression profiling of primary cultured buffalo granulosa cells from different follicular size in comparison with their in vivo counterpart

“…In mammalian species, AMH is mainly secreted by immature GCs of developing follicles in the ovarian tissues (Bhide and Homburg, 2016). It was found that expression of AMH mRNA decreased during the pre-ovulatory stage, which was associated with subsequently reduction in growing follicle response to FSH, to reduce the number of developing follicles (Visser et al, 2006;Teh et al, 2018). Furthermore, AMH played important roles in mammalian ovarian tissues to regulate the response of growing follicles to gonadotrophin during follicular development, as well as decrease the incidence of follicular atresia (Hernandez-Medrano et al, 2012;Seifer and Merhi, 2014;Kereilwe and Kadokawa, 2019).…”

Üreme Mevsimi Dışında Kazak Koyunlarının Üremeleri Üzerine İnhibin-βA Geninin Etkisi

“…Inhibin inhibits FSH secretion from the anterior pituitary and in turn regulates gonadal function and development [4] . And the mutations of INHBA gene effects on litter size in sheep significantly [5] , and plasma inhibin concentrations was related to higher ovulation rates in pigs during follicular phase [6] . Ovaries were recovered from six adult female Lezhi black goats and Tibetan goats at 12-24 h after onset of estrus, and used to collect follicles to study cDNA sequence and mRNA expression of INHA and INHBA genes, and the result showed that base changes in INHA and INHBA genes resulting in amino acid substitutions may be important in regulating the differential fecundity of these goat breeds as molecular mechanism [7] .…”