Expression of bta-miR-222 and LHCGR in bovine cultured granulosa cells: Impact of follicle deviation and regulation by FSH/insulin in vitro

Author(s)

Santos, P. H. ; Nunes, S. G. ; Franchi, F. F. ; Giroto, A. B. ; Fontes, P. K. ; Pinheiro, V. G. ; Castilho, A. C. S.

• Document type: Journal article
• Source: Theriogenology; v. 182, p. 7-pg., 2022-02-04.

Abstract

Final antral follicle development and future ovulation are mediated by gonadotropin-induced changes with spatio-temporally regulated expression of genes. Here, we aimed to quantify the relative mRNA abundance of bta-miR-222 and its predicted target, LHCGR, in granulosa cells (GCs) from follicles, after follicle deviation, as well as from GCs cultured in vitro with follicle stimulating hormone (FSH) and/or insulin. Thus, to study the impact of follicle deviation, Nelore heifers (n = 10; Bos taurus indicus) were hormonally synchronized and slaughtered 3 days after ovulation. Then, GCs from the dominant follicle (DF) and its respective subordinate follicle (SF) were recovered for RT-qPCR. For in vitro analysis, small follicles (2-5 mm) were dissected from bovine ovaries collected from a local abattoir. The GCs were isolated and cultured in serum-free medium, or treated with insulin (1 ng/mL or 10 ng/mL) alone or in combination with human recombinant FSH (1 ng/mL), for 6 days. Our findings showed that the relative mRNA abundance of LHCGR in GCs was higher in the DF compared to the SF (p = 0.01). Inversely, bta-miR-222 expression was lower in the DF compared to the SF (p = 0.01). Furthermore, GCs cultured with FSH and insulin together resulted in a higher abundance of LHCGR and a lower abundance of bta-miR-222 (p <= 0.05) when compared to GCs cultured with insulin alone. In conclusion, we found that the LHCGR upregulation in GCs from the DF is inversely related to bta-miR-222 expression. We also suggest the involvement of FSH in bta-miR-222 suppression in healthy bovine GCs. (c) 2022 Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 15/04505-5 - Characterization of microRNAs (miRNAs) in bovine antral follicles from Nelore cows: involvement during ovarian follicle cells differentiation and regulation of LH receptor (LHR) expression
• Grantee: Anthony César de Souza Castilho
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 13/11480-3 - Characterization of microRNAs (miRNAs) in bovine antral follicles from Nelore cattle: involvement during ovarian follicle cells differentiation and regulation of LH receptor (LHr) expression
• Grantee: Anthony César de Souza Castilho
• Support Opportunities: Research Grants - Young Investigators Grants