Functional effects of Tribbles Homolog 2 (TRIB2) in bovine ovarian granulosa cells.

Functional effects of Tribbles Homolog 2 (TRIB2) in bovine ovarian granulosa cells. Biol Reprod. 2020 Mar 11;: Authors: Warma A, Ndiaye K Abstract Tribbles homolog (TRIB) 1, 2 and 3 represent atypical members of the serine/threonine kinase superfamily. We previously identified TRIB2 as a differentially expressed gene in granulosa cells of bovine preovulatory follicles. The current study aimed to further investigate TRIB2 regulation and study its function in the ovary. Granulosa cells (GC) were collected from follicles at different developmental stages: small antral follicles (SF), dominant follicles at day 5 of the estrous cycle (DF) and hCG-induced ovulatory follicles (OF). RT-qPCR analyses showed greater expression of TRIB2 in GC of DF as compared to OF and a significant downregulation of TRIB2 steady-state mRNA amounts by hCG/LH, starting at 6 hours through 24 hours post-hCG as compared to 0 hour. Specific anti-TRIB2 polyclonal antibodies were generated and western blot analysis confirmed TRIB2 downregulation by hCG at the protein level. In vitro studies showed that FSH stimulates TRIB2 expression in GC. Inhibition of TRIB2 using CRISPR/Cas9 resulted in a significant increase in PCNA expression and an increase in steroidogenic enzyme CYP19A1 expression, while TRIB2 overexpression tended to decrease GC proliferation. TRIB2 inhibition also resulted in a decrease in transcription factors CTGF and ANKRD1 expression, while TRIB2 ove...
Source: Biology of Reproduction - Category: Reproduction Medicine Authors: Tags: Biol Reprod Source Type: research